[Molecular characterization of Streptococcus pyogenes from invasive disease and streptococcal toxic shock syndrome episodes].

PubMed

Traverso, F; Sparo, M; Rubio, V; Sáez Nieto, J A

2010-01-01

Streptococcus pyogenes causes a variety of common human diseases, including pharyngitis, scarlet fever and impetigo. Nevertheless, the past decades have witnessed a worldwide resurgence in invasive disease and streptococcal toxic shock syndrome (STSS). The objective of the present study is to evaluate the genetic diversity, virulence gene distribution (spe, sme and ssa genes) and susceptibility pattern of 10 S. pyogenes isolates causing invasive disease and STSS. The isolates were recovered from blood cultures of hospitalized patients at Hospital Santamarina and Nueva Clínica Chacabuco, Tandil, Buenos Aires, Argentina between 12/2000-04/2005. Two pulse field gel electrophoretic patterns predominated. The most frequent one included 5 characteristic isolates of emm1-T1 type, toxin gene profile speA, speB, speF, speG and smeZ. The second pattern included 2 characteristic isolates of emm3-TNT type (speB, speF, speG). The other 3 isolates corresponded to types emm49-TNT (speB, speC, speF, speG), emm75-T25 (speB, speF, speG) and emm83-TNT (speB, speF, speG, ssa, smeZ). All isolates were susceptible to penicillin, cefotaxime, erythromycin, clindamycin, chloramphenicol, tetracycline and rifampicin. The data from the present study demonstrated genetic diversity among the strains. Types emm1 and emm3 were prevalent in invasive disease. The empirical treatment with the combination of penicillin and clindamicin is still valid.

Salmonella enterica Serotype Napoli is the First Cause of Invasive Nontyphoidal Salmonellosis in Lombardy, Italy (2010-2014), and Belongs to Typhi Subclade.

PubMed

Huedo, Pol; Gori, Maria; Zolin, Anna; Amato, Ettore; Ciceri, Giulia; Bossi, Anna; Pontello, Mirella

2017-03-01

Salmonella enterica serotype Napoli (S. Napoli) is currently emerging in Europe and particularly in Italy, where in 2014 it caused a large outbreak associated with elevated rates of bacteremia. However, no study has yet investigated its invasive ability and phylogenetic classification. Here, we show that between 2010 and 2014, S. Napoli was the first cause of invasive salmonellosis affecting 40 cases out of 687 (invasive index: 5.8%), which is significantly higher than the invasive index of all the other nontyphoidal serotypes (2.0%, p < 0.05). Genomic and phylogenetic analyses of an invasive isolate revealed that S. Napoli belongs to Typhi subclade in clade A, Paratyphi A being the most related serotype and carrying almost identical pattern of typhoid-associated genes. This work presents evidence of invasive capacity of S. Napoli and argues for reconsideration of its nontyphoidal category.

Actinomyces Species Isolated from Breast Infections.

PubMed

Bing, A U; Loh, S F; Morris, T; Hughes, H; Dixon, J M; Helgason, K O

2015-10-01

Actinomycosis is a chronic infection caused by Actinomyces species characterized by abscess formation, tissue fibrosis, and draining sinuses. The spectrum of infections caused by Actinomyces species ranges from classical invasive actinomycosis to a less invasive form of superficial skin and soft tissue infection. We present a review detailing all Actinomyces species isolated from breast infections in NHS Lothian between 2005 and 2013, Actinomyces species isolated from breast infections referred to the United Kingdom Anaerobe Reference Unit between 1988 and 2014, and cases describing Actinomyces breast infections published in the medical literature since 1994. Actinomyces species are fastidious organisms which can be difficult to identify and are likely to be underascertained as a cause of breast infections. Due to improved diagnostic methods, they are increasingly associated with chronic, recurrent breast infections and may play a more significant role in these infections than has previously been appreciated. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Actinomyces Species Isolated from Breast Infections

PubMed Central

Loh, S. F.; Morris, T.; Hughes, H.; Dixon, J. M.

2015-01-01

Actinomycosis is a chronic infection caused by Actinomyces species characterized by abscess formation, tissue fibrosis, and draining sinuses. The spectrum of infections caused by Actinomyces species ranges from classical invasive actinomycosis to a less invasive form of superficial skin and soft tissue infection. We present a review detailing all Actinomyces species isolated from breast infections in NHS Lothian between 2005 and 2013, Actinomyces species isolated from breast infections referred to the United Kingdom Anaerobe Reference Unit between 1988 and 2014, and cases describing Actinomyces breast infections published in the medical literature since 1994. Actinomyces species are fastidious organisms which can be difficult to identify and are likely to be underascertained as a cause of breast infections. Due to improved diagnostic methods, they are increasingly associated with chronic, recurrent breast infections and may play a more significant role in these infections than has previously been appreciated. PMID:26224846

Incidence of virulence determinants in clinical Enterococcus faecalis and Enterococcus faecium isolates collected in Bulgaria.

PubMed

Strateva, Tanya; Atanasova, Daniela; Savov, Encho; Petrova, Guergana; Mitov, Ivan

2016-01-01

To evaluate the prevalence of some virulence genes among 510 clinical Enterococcus spp. isolates and to assess the association of those genes with the species, infection site, and patient group (inpatients/outpatients). Adhesins genes (aggregation substances agg and asa1 of Enterococcus faecalis and Enterococcus faecium, respectively), enterococcal surface protein (esp), endocarditis-specific antigen A (efaA), collagen-binding proteins (ace/acm)); invasins (hyaluronidase (hyl) and gelatinase (gelE)); cytotoxines (activation of cytolysin (cylA) in E. faecalis); and modulators of the host immunity and inflammation (enhanced expression pheromone (eep) in E. faecalis) were detected by polymerase chain reaction. The overall prevalence was: esp - 44.3%, agg/asa1 - 38.4%, ace/acm - 64.3%, efaA - 85.9%, eep - 69.4%, gelE - 64.3%, hyl - 25.1%, and cylA - 47.1%. E. faecalis isolates had significantly higher frequency of adhesin genes (esp and agg/asa1) and gelatinase in comparison to E. faecium. Multiple virulence genes in E. faecalis were significantly more prevalent than in E. faecium isolates. Domination of E. faecium with or without only one gene compared to the isolates of E. faecalis were found. Enterococcus spp. isolates obtained from outpatients compared to inpatients isolates had significantly higher frequency of agg/asa1, eep, gelE and cylA. Some adhesins genes (esp, agg/asa1 and efaA) had higher prevalence among the non-invasive Enterococcus spp. isolates compared to those causing invasive bacteremia, while ace/acm revealed higher dissemination in isolates causing invasive infections compared to non-invasive isolates. Most E. faecalis attaches to abiotic surfaces in hospital environment, which correlates with higher prevalence of gene encoding for virulence factors involved in biofilm formation, such as enterococcal surface protein, aggregation substance, and gelatinase. The intestinal tract is an important reservoir for opportunistic enterococcal pathogens and allows them to access infectious sites through different virulence factors, demonstrated in outpatient isolates in this study. Copyright © 2016 Elsevier Editora Ltda. All rights reserved.

Serotype IV and invasive group B Streptococcus disease in neonates, Minnesota, USA, 2000-2010.

PubMed

Ferrieri, Patricia; Lynfield, Ruth; Creti, Roberta; Flores, Aurea E

2013-04-01

Group B Streptococcus (GBS) is a major cause of invasive disease in neonates in the United States. Surveillance of invasive GBS disease in Minnesota, USA, during 2000-2010 yielded 449 isolates from 449 infants; 257 had early-onset (EO) disease (by age 6 days) and 192 late-onset (LO) disease (180 at age 7-89 days, 12 at age 90-180 days). Isolates were characterized by capsular polysaccharide serotype and surface-protein profile; types III and Ia predominated. However, because previously uncommon serotype IV constitutes 5/31 EO isolates in 2010, twelve type IV isolates collected during 2000-2010 were studied further. By pulsed-field gel electrophoresis, they were classified into 3 profiles; by multilocus sequence typing, representative isolates included new sequence type 468. Resistance to clindamycin or erythromycin was detected in 4/5 serotype IV isolates. Emergence of serotype IV GBS in Minnesota highlights the need for serotype prevalence monitoring to detect trends that could affect prevention strategies.

Infection with Scedosporium apiospermum and S. prolificans, Australia

PubMed Central

Cooley, Louise; Spelman, Denis; Thursky, Karin

2007-01-01

Scedosporium apiospermum and S. prolificans are fungi of increasing clinical importance, particularly in persons with underlying diseases. We reviewed the records of 59 patients in Australia from whom Scedosporium spp. were isolated from June 30, 1997, through December 31, 2003. S. apiospermum was isolated predominantly from the respiratory tracts of 28 of 31 patients with underlying lung diseases and resulted in 2 infections and 1 death. The annual number of S. apiospermum isolates remained constant. S. prolificans was isolated from 28 patients only after November 1999. Eight patients with acute myeloid leukemia or hematopoietic stem cell transplants had invasive infection; 4 had fungemia and 6 died from infection. S. prolificans caused locally invasive infection in 2 immunocompetent patients and was found in the respiratory tract of 18 patients with underlying respiratory disease but did not cause fungemia or deaths in these patients. Scedosporium spp. showed distinct clinical and epidemiologic features. PMID:17953087

Density and Molecular Epidemiology of Aspergillus in Air and Relationship to Outbreaks of Aspergillus Infection

PubMed Central

Leenders, Alexander C. A. P.; van Belkum, Alex; Behrendt, Myra; Luijendijk, Ad; Verbrugh, Henri A.

1999-01-01

After five patients were diagnosed with nosocomial invasive aspergillosis caused by Aspergillus fumigatus and A. flavus, a 14-month surveillance program for pathogenic and nonpathogenic fungal conidia in the air within and outside the University Hospital in Rotterdam (The Netherlands) was begun. A. fumigatus isolates obtained from the Department of Hematology were studied for genetic relatedness by randomly amplified polymorphic DNA (RAPD) analysis. This was repeated with A. fumigatus isolates contaminating culture media in the microbiology laboratory. The density of the conidia of nonpathogenic fungi in the outside air showed a seasonal variation: higher densities were measured during the summer, while lower densities were determined during the fall and winter. Hardly any variation was found in the numbers of Aspergillus conidia. We found decreasing numbers of conidia when comparing air from outside the hospital to that inside the hospital and when comparing open areas within the hospital to the closed department of hematology. The increase in the number of patients with invasive aspergillosis could not be explained by an increase in the number of Aspergillus conidia in the outside air. The short-term presence of A. flavus can only be explained by the presence of a point source, which was probably patient related. Genotyping A. fumigatus isolates from the department of hematology showed that clonally related isolates were persistently present for more than 1 year. Clinical isolates of A. fumigatus obtained during the outbreak period were different from these persistent clones. A. fumigatus isolates contaminating culture media were all genotypically identical, indicating a causative point source. Knowledge of the epidemiology of Aspergillus species is necessary for the development of strategies to prevent invasive aspergillosis. RAPD fingerprinting of Aspergillus isolates can help to determine the cause of an outbreak of invasive aspergillosis. PMID:10325319

Epidemiology and emm types of invasive group A streptococcal infections in Finland, 2008-2013.

PubMed

Smit, P W; Lindholm, L; Lyytikäinen, O; Jalava, J; Pätäri-Sampo, A; Vuopio, J

2015-10-01

Invasive Streptococcus pyogenes (group A streptococcus, GAS) infections are a major global cause of morbidity and mortality. We analysed the surveillance data on invasive GAS and the microbiological characteristics of corresponding isolates to assess the incidence and emm type distribution of invasive GAS infections in Finland. Cases defined as patients with isolations of blood and cerebrospinal fluid S. pyogenes are mandatorily notified to the National Infectious Disease Registry and sent to the national reference laboratory for emm typing. Antimicrobial data were collected through the network including all clinical microbiology laboratories. Pulsed-field gel electrophoresis (PFGE) analysis was performed to assess clonality. In total, 1165 cases of invasive GAS were reported in Finland during 2008-2013; the median age was 52 years (range, 0-100) and 54% were male. The overall day 7 case fatality rate was 5.1% (59 cases). The average annual incidence was 3.6 cases per 100,000 population. A total of 1122 invasive GAS isolates (96%) were analysed by emm typing; 72 different emm types were identified, of which emm28 (297 isolates, 26%), emm89 (193 isolates, 12%) and emm1 (132 isolates, 12%) were the most common types. During 2008-2013, an increase of erythromycin resistance (1.9% to 8.7%) and clindamycin (0.9% to 9.2%) was observed. This resistance increase was in parallel with the introduction of a novel clone emm33 into Finland. The overall incidence of invasive GAS infections remained stable over the study period in Finland. We identified clonal spread of macrolide-resistant invasive emm33 GAS type, highlighting the importance of molecular surveillance.

Central nervous system involvement in adult patients with invasive infection caused by Streptococcus agalactiae.

PubMed

Oyanguren, B; Esteban, L; Guillán, M; de Felipe, A; Alonso Cánovas, A; Navas, E; Quereda, C; Corral, I

2015-04-01

Streptococcus agalactiae is frequently an asymptomatic coloniser and a cause of neonatal and puerperal sepsis. Infections in nonpregnant adults are uncommon. The frequency of neurological complications caused by invasive infection with this microorganism in adults remains unknown. Here, we study the frequency and characteristics of central nervous system (CNS) involvement in adults with invasive S. agalactiae infection. Review of all adults with invasive S. agalactiae infection between 2003 and 2011 in a tertiary hospital. S. agalactiae was isolated from blood, CSF or synovial fluid in 75 patients. Among them, 7 (9,3%) displayed neurological involvement: 5 men and 2 nonpregnant women, aged between 20 and 62 years. Diagnoses were spinal epidural abscess due to spondylodiscitis with spinal cord compression; acute bacterial meningitis; ischemic stroke as presentation of bacterial endocarditis (2 patients each); and meningoventriculitis after neurosurgery and ventricular shunting. One patient with endocarditis caused by S. agalactiae and S. aureus died in the acute phase, and another died 3 months later from metastatic cancer. The other patients recovered without sequelae. All patients had systemic predisposing factors for infection and 5 (71,4%) had experienced disruption of the mucocutaneous barrier as a possible origin of the infection. CNS involvement is not uncommon in adult patients with invasive infection caused by S. agalactiae. Isolating S. agalactiae, especially in cases of meningitis, should lead doctors to search for predisposing systemic disease and causes of mucocutaneous barrier disruption. Copyright © 2013 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

Staphylococcus aureus requires less virulence to establish an infection in diabetic hosts.

PubMed

Tuchscherr, Lorena; Korpos, Èva; van de Vyver, Hélène; Findeisen, Clais; Kherkheulidze, Salome; Siegmund, Anke; Deinhardt-Emmer, Stefanie; Bach, Olaf; Rindert, Martin; Mellmann, Alexander; Sunderkötter, Cord; Peters, Georg; Sorokin, Lydia; Löffler, Bettina

2018-05-22

Staphylococcus aureus is the most frequent pathogen causing diabetic foot infections. Here, we investigated the degree of bacterial virulence required to establish invasive tissue infections in diabetic organisms. Staphylococcal isolates from diabetic and non-diabetic foot ulcers were tested for their virulence in in vitro functional assays of host cell invasion and cytotoxicity. Isolates from diabetes mellitus type I/II patients exhibited less virulence than isolates from non-diabetic patients, but were nevertheless able to establish severe infections. In some cases, non-invasive isolates were detected deep within diabetic wounds, even though the strains were non-pathogenic in cell culture models. Testing of defined isolates in murine footpad injection models revealed that both low- and high-virulent bacterial strains persisted in higher numbers in diabetic compared to non-diabetic hosts, suggesting that hyperglycemia favors bacterial survival. Additionally, the bacterial load was higher in NOD mice, which have a compromised immune system, compared to C57Bl/6 mice. Our results reveal that high as well as low-virulent staphylococcal strains are able to cause soft tissue infections and to persist in diabetic humans and mice, suggesting a reason for the frequent and endangering infections in patients with diabetes. Copyright © 2018 Elsevier GmbH. All rights reserved.

Relationship between antibody susceptibility and lipopolysaccharide O-antigen characteristics of invasive and gastrointestinal nontyphoidal Salmonellae isolates from Kenya.

PubMed

Onsare, Robert S; Micoli, Francesca; Lanzilao, Luisa; Alfini, Renzo; Okoro, Chinyere K; Muigai, Anne W; Revathi, Gunturu; Saul, Allan; Kariuki, Samuel; MacLennan, Calman A; Rondini, Simona

2015-03-01

Nontyphoidal Salmonellae (NTS) cause a large burden of invasive and gastrointestinal disease among young children in sub-Saharan Africa. No vaccine is currently available. Previous reports indicate the importance of the O-antigen of Salmonella lipopolysaccharide for virulence and resistance to antibody-mediated killing. We hypothesised that isolates with more O-antigen have increased resistance to antibody-mediated killing and are more likely to be invasive than gastrointestinal. We studied 192 NTS isolates (114 Typhimurium, 78 Enteritidis) from blood and stools, mostly from paediatric admissions in Kenya 2000-2011. Isolates were tested for susceptibility to antibody-mediated killing, using whole adult serum. O-antigen structural characteristics, including O-acetylation and glucosylation, were investigated. Overall, isolates were susceptible to antibody-mediated killing, but S. Enteritidis were less susceptible and expressed more O-antigen than Typhimurium (p<0.0001 for both comparisons). For S. Typhimurium, but not Enteritidis, O-antigen expression correlated with reduced sensitivity to killing (r = 0.29, 95% CI = 0.10-0.45, p = 0.002). Both serovars expressed O-antigen populations ranging 21-33 kDa average molecular weight. O-antigen from most Typhimurium were O-acetylated on rhamnose and abequose residues, while Enteritidis O-antigen had low or no O-acetylation. Both Typhimurium and Enteritidis O-antigen were approximately 20%-50% glucosylated. Amount of S. Typhimurium O-antigen and O-antigen glucosylation level were inversely related. There was no clear association between clinical presentation and antibody susceptibility, O-antigen level or other O-antigen features. Kenyan S. Typhimurium and Enteritidis clinical isolates are susceptible to antibody-mediated killing, with degree of susceptibility varying with level of O-antigen for S. Typhimurium. This supports the development of an antibody-inducing vaccine against NTS for Africa. No clear differences were found in the phenotype of isolates from blood and stool, suggesting that the same isolates can cause invasive disease and gastroenteritis. Genome studies are required to understand whether invasive and gastrointestinal isolates differ at the genotypic level.

Comparison of In Vitro Susceptibility Characteristics of Candida Species from Cases of Invasive Candidiasis in Solid Organ and Stem Cell Transplant Recipients: Transplant-Associated Infections Surveillance Network (TRANSNET), 2001 to 2006▿

PubMed Central

Lockhart, Shawn R.; Wagner, Debra; Iqbal, Naureen; Pappas, Peter G.; Andes, David R.; Kauffman, Carol A.; Brumble, Lisa M.; Hadley, Susan; Walker, Randall; Ito, James I.; Baddley, John W.; Chiller, Tom; Park, Benjamin J.

2011-01-01

Invasive fungal infections (IFI) are a major cause of morbidity and mortality among both solid organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) recipients. Candida is the most common cause of IFI in SOT recipients and the second most common cause of IFI in HSCT recipients. We determined susceptibilities to fluconazole, voriconazole, itraconazole, posaconazole, amphotericin B, and caspofungin for 383 invasive Candida sp. isolates from SOT and HSCT recipients enrolled in the Transplant-Associated Infection Surveillance Network and correlated these results to clinical data. Fluconazole resistance in C. albicans, C. tropicalis, and C. parapsilosis isolates was low (1%), but the high percentage of C. glabrata and C. krusei isolates within this group of patients increased the overall percentage of fluconazole resistance to 16%. Voriconazole resistance was 3% overall but was 8% among C. glabrata isolates. On multivariable analysis, among HSCT recipients fluconazole nonsusceptibility was independently associated with C. glabrata, non-Hodgkin's lymphoma, cytomegalovirus (CMV) antigenemia, diabetes active at the time of the IFI, and any prior amphotericin B use; among SOT recipients, fluconazole nonsusceptibility was independently associated with any fluconazole use in the 3 months prior to the IFI, C. glabrata, ganciclovir use in the 3 months prior to the IFI, diabetes acquired since the transplant, and gender. PMID:21562099

Distinct Salmonella Enteritidis lineages associated with enterocolitis in high-income settings and invasive disease in low-income settings

PubMed Central

Feasey, Nicholas A.; Hadfield, James; Keddy, Karen H.; Dallman, Timothy J; Jacobs, Jan; Deng, Xiangyu; Wigley, Paul; Barquist, Lars; Langridge, Gemma C.; Feltwell, Theresa; Harris, Simon R.; Mather, Alison E.; Fookes, Maria; Aslett, Martin; Msefula, Chisomo; Kariuki, Samuel; Maclennan, Calman A.; Onsare, Robert S.; Weill, François-Xavier; Le Hello, Simon; Smith, Anthony M.; McClelland, Michael; Desai, Prerak; Parry, Christopher M.; Cheesbrough, John; French, Neil; Campos, Josefina; Chabalgoity, Jose A.; Betancor, Laura; Hopkins, Katie L.; Nair, Satheesh; Humphrey, Tom J.; Lunguya, Octavie; Cogan, Tristan A.; Tapia, Milagritos D.; Sow, Samba O.; Tennant, Sharon M.; Bornstein, Kristin; Levine, Myron M.; Lacharme-Lora, Lizeth; Everett, Dean B.; Kingsley, Robert A.; Parkhill, Julian; Heyderman, Robert S.; Dougan, Gordon

2016-01-01

An epidemiological paradox surrounds Salmonella enterica serovar Enteritidis. In high-income settings, it has been responsible for an epidemic of poultry-associated, self-limiting enterocolitis, whilst in sub-Saharan Africa it is a major cause of invasive nontyphoidal Salmonella disease, associated with high case-fatality. Whole-genome sequence analysis of 675 isolates of S. Enteritidis from 45 countries reveals the existence of a global epidemic clade and two novel clades of S. Enteritidis that are each geographically restricted to distinct regions of Africa. The African isolates display genomic degradation, a novel prophage repertoire and have an expanded, multidrug resistance plasmid. S. Enteritidis is a further example of a Salmonella serotype that displays niche plasticity, with distinct clades that enable it to become a prominent cause of gastroenteritis in association with the industrial production of eggs, and of multidrug resistant, bloodstream invasive infection in Africa. PMID:27548315

Distinct Salmonella Enteritidis lineages associated with enterocolitis in high-income settings and invasive disease in low-income settings.

PubMed

Feasey, Nicholas A; Hadfield, James; Keddy, Karen H; Dallman, Timothy J; Jacobs, Jan; Deng, Xiangyu; Wigley, Paul; Barquist, Lars; Langridge, Gemma C; Feltwell, Theresa; Harris, Simon R; Mather, Alison E; Fookes, Maria; Aslett, Martin; Msefula, Chisomo; Kariuki, Samuel; Maclennan, Calman A; Onsare, Robert S; Weill, François-Xavier; Le Hello, Simon; Smith, Anthony M; McClelland, Michael; Desai, Prerak; Parry, Christopher M; Cheesbrough, John; French, Neil; Campos, Josefina; Chabalgoity, Jose A; Betancor, Laura; Hopkins, Katie L; Nair, Satheesh; Humphrey, Tom J; Lunguya, Octavie; Cogan, Tristan A; Tapia, Milagritos D; Sow, Samba O; Tennant, Sharon M; Bornstein, Kristin; Levine, Myron M; Lacharme-Lora, Lizeth; Everett, Dean B; Kingsley, Robert A; Parkhill, Julian; Heyderman, Robert S; Dougan, Gordon; Gordon, Melita A; Thomson, Nicholas R

2016-10-01

An epidemiological paradox surrounds Salmonella enterica serovar Enteritidis. In high-income settings, it has been responsible for an epidemic of poultry-associated, self-limiting enterocolitis, whereas in sub-Saharan Africa it is a major cause of invasive nontyphoidal Salmonella disease, associated with high case fatality. By whole-genome sequence analysis of 675 isolates of S. Enteritidis from 45 countries, we show the existence of a global epidemic clade and two new clades of S. Enteritidis that are geographically restricted to distinct regions of Africa. The African isolates display genomic degradation, a novel prophage repertoire, and an expanded multidrug resistance plasmid. S. Enteritidis is a further example of a Salmonella serotype that displays niche plasticity, with distinct clades that enable it to become a prominent cause of gastroenteritis in association with the industrial production of eggs and of multidrug-resistant, bloodstream-invasive infection in Africa.

Phylogenetics of a fungal invasion: origins and widespread dispersal of white-nose syndrome

Treesearch

Kevin P. Drees; Jeffrey M. Lorch; Sebastien J. Puechmaille; Katy L. Parise; Gudrun Wibbelt; Joseph R. Hoyt; Keping Sun; Ariunbold Jargalsaikhan; Munkhnast Dalannast; Jonathan M. Palmer; Daniel L. Lindner; A. Marm Kilpatrick; Talima Pearson; Paul S. Keim; David S. Blehert; Jeffrey T. Foster; Joseph Heitman

2017-01-01

Globalization has facilitated the worldwide movement and introduction of pathogens, but epizoological reconstructions of these invasions are often hindered by limited sampling and insufficient genetic resolution among isolates. Pseudogymnoascus destructans, a fungal pathogen causing the epizootic of white-nose syndrome in North American bats, has...

Dominance of serotype Ia among group B Streptococci causing invasive infections in nonpregnant adults in Portugal.

PubMed

Martins, E R; Melo-Cristino, J; Ramirez, M

2012-04-01

The population of group B streptococci (GBS) associated with invasive infections in nonpregnant adults from 2001 to 2008 was analyzed in isolates submitted from 24 hospital laboratories in Portugal (n = 225). The isolates were characterized by antimicrobial susceptibility, pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and surface protein gene profiling. GBS invasive cases were found more frequently among men in all age groups. In addition, serotype Ia was the most frequent in our collection, whereas serotype V is dominant elsewhere. Serotype Ia was represented mainly by a single PFGE cluster defined by sequence type 23 (ST23) and surface protein gene eps and by ST24 and bca, similarly to neonatal invasive infections in Portugal, indicating that the same genetic lineages can be responsible for both vaginal colonization and invasive disease in all age groups. In contrast, the hypervirulent serotype III/ST17 neonatal lineage was responsible for a minority of infections. Serotype V isolates were distributed into two genetic lineages, one defined by ST1 and surface protein gene alp3 and macrolide resistant, and another presenting with ST2 and eps and fully susceptible to all antimicrobials tested. The erm(TR) gene was the most frequently found among erythromycin-resistant isolates, while the bovine-associated tet(O) gene was found in a minority of tetracycline-resistant isolates. Our data emphasize the importance of local identification of the genetic lineages responsible for GBS invasive infections in nonpregnant adults. The dominance of serotype Ia in invasive disease in Portugal highlights the importance of this serotype in GBS pathogenesis.

Characterization of Genetic and Phenotypic Diversity of Invasive Nontypeable Haemophilus influenzae

PubMed Central

Erwin, Alice L.; Nelson, Kevin L.; Mhlanga-Mutangadura, Tendai; Bonthuis, Paul J.; Geelhood, Jennifer L.; Morlin, Gregory; Unrath, William C. T.; Campos, Jose; Crook, Derrick W.; Farley, Monica M.; Henderson, Frederick W.; Jacobs, Richard F.; Mühlemann, Kathrin; Satola, Sarah W.; van Alphen, Loek; Golomb, Miriam; Smith, Arnold L.

2005-01-01

The ability of unencapsulated (nontypeable) Haemophilus influenzae (NTHi) to cause systemic disease in healthy children has been recognized only in the past decade. To determine the extent of similarity among invasive nontypeable isolates, we compared strain R2866 with 16 additional NTHi isolates from blood and spinal fluid, 17 nasopharyngeal or throat isolates from healthy children, and 19 isolates from middle ear aspirates. The strains were evaluated for the presence of several genetic loci that affect bacterial surface structures and for biochemical reactions that are known to differ among H. influenzae strains. Eight strains, including four blood isolates, shared several properties with R2866: they were biotype V (indole and ornithine decarboxylase positive, urease negative), contained sequence from the adhesin gene hia, and lacked a genetic island flanked by the infA and ksgA genes. Multilocus sequence typing showed that most biotype V isolates belonged to the same phylogenetic cluster as strain R2866. When present, the infA-ksgA island contains lipopolysaccharide biosynthetic genes, either lic2B and lic2C or homologs of the losA and losB genes described for Haemophilus ducreyi. The island was found in most nasopharyngeal and otitis isolates but was absent from 40% of invasive isolates. Overall, the 33 hmw-negative isolates were much more likely than hmw-containing isolates to have tryptophanase, ornithine decarboxylase, or lysine decarboxylase activity or to contain the hif genes. We conclude (i) that invasive isolates are genetically and phenotypically diverse and (ii) that certain genetic loci of NTHi are frequently found in association among NTHi strains. PMID:16113304

Early detection monitoring of Phytophthora ramorum in high-risk forests of California

Treesearch

Ross Meentemeyer; Elizabeth Lotz; David M. Rizzo; Kelly Buja; Walter Mark

2006-01-01

Early detection monitoring is essential for successful control of invasive organisms. Detection of invasions at an early stage of establishment when a population is small and isolated makes eradication more feasible and less costly. Sudden oak death, caused by the recently described pathogen Phytophthora ramorum, is an emerging forest disease that...

Galactomannan Enzymatic Immunoassay Cross-Reactivity Caused by Prototheca Species

PubMed Central

Van den Bossche, D.; Hendrickx, M.; De Becker, A.; Jacobs, R.; Naessens, A.; Piérard, D.

2012-01-01

We report a reactive Aspergillus galactomannan enzymatic immunoassay against the serum of a patient with invasive Prototheca zopfii infection. Analysis of the supernatants of suspensions of P. zopfii and other Prototheca isolates revealed positive results as well. These data suggest cross-reactivity with the serum Aspergillus galactomannan assay in invasive protothecosis. PMID:22837317

Differences in the population structure of invasive Streptococcus suis strains isolated from pigs and from humans in The Netherlands.

PubMed

Schultsz, Constance; Jansen, Ewout; Keijzers, Wendy; Rothkamp, Anja; Duim, Birgitta; Wagenaar, Jaap A; van der Ende, Arie

2012-01-01

Streptococcus suis serotype 2 is the main cause of zoonotic S. suis infection despite the fact that other serotypes are frequently isolated from diseased pigs. Studies comparing concurrent invasive human and pig isolates from a single geographical location are lacking. We compared the population structures of invasive S. suis strains isolated between 1986 and 2008 from human patients (N = 24) and from pigs with invasive disease (N = 124) in The Netherlands by serotyping and multi locus sequence typing (MLST). Fifty-six percent of pig isolates were of serotype 9 belonging to 15 clonal complexes (CCs) or singleton sequence types (ST). In contrast, all human isolates were of serotype 2 and belonged to two non-overlapping clonal complexes CC1 (58%) and CC20 (42%). The proportion of serotype 2 isolates among S. suis strains isolated from humans was significantly higher than among strains isolated from pigs (24/24 vs. 29/124; P<0.0001). This difference remained significant when only strains within CC1 and CC20 were considered (24/24 vs. 27/37,P = 0.004). The Simpson diversity index of the S. suis population isolated from humans (0.598) was smaller than of the population isolated from pigs (0.765, P = 0.05) indicating that the S. suis population isolated from infected pigs was more diverse than the S. suis population isolated from human patients. S. suis serotype 2 strains of CC20 were all negative in a PCR for detection of genes encoding extracellular protein factor (EF) variants. These data indicate that the polysaccharide capsule is an important correlate of human S. suis infection, irrespective of the ST and EF encoding gene type of S. suis strains.

Diversity of pneumococcal surface protein A (PspA) and relation to sequence typing in Streptococcus pneumoniae causing invasive disease in Chinese children.

PubMed

Qian, J; Yao, K; Xue, L; Xie, G; Zheng, Y; Wang, C; Shang, Y; Wang, H; Wan, L; Liu, L; Li, C; Ji, W; Wang, Y; Xu, P; Yu, S; Tang, Y-W; Yang, Y

2012-03-01

The objective of this paper was to investigate the sequence types (STs) and diversity of surface antigen pneumococcal surface protein A (PspA) in 171 invasive Streptococcus pneumoniae isolates from Chinese children. A total of 171 pneumococci isolates were isolated from Chinese children with invasive pneumococcal diseases (IPD) in 11 hospitals between 2006 and 2008. The pneumococci samples were characterized by serotyping, PspA classification, and multilocus sequence typing (MLST). The PspA of these strains could be assigned to two families. The PspA family 2 was the most common (120/171, 70.1%). No PspA family 3 isolates were detected. Family 1 could be subdivided into two clades, with 42 strains in clade 1 and 9 strains in clade 2, and family 2 could be subdivided into clades 3, 4, and 5, which respectively contained 5, 21, and 14 strains. In total, 65 STs were identified, of which ST320 (30/171, 17.5%), ST271 (23/171, 13.5%), and ST876 (18/171, 10.5%) were the most common types. PspA family 2 and family 1 were dominant among pneumococcal clones isolated from Chinese children with invasive disease. The strains with the same ST always presented in the same PspA family.

Culture Collections and Public Health Research

USDA-ARS?s Scientific Manuscript database

Listeria monocytogenes is a foodborne pathogen capable of causing serious invasive illness in humans and other animals, and a leading cause of food recalls. The establishment and growth of a research collection of Listeria isolates has been critical in developing an evolutionary genetic framework, n...

Echinocandin Resistance in Candida Species: a Review of Recent Developments.

PubMed

Wiederhold, Nathan P

2016-12-01

The echinocandins are important agents for the treatment of invasive fungal infections, especially those caused by Candida species. However, as with other antimicrobial agents, microbiologic resistance to this class of antifungal agents has emerged and can result in clinical failure. Several studies have recently reported an increase in echinocandin resistance in Candida glabrata isolates at various medical centers in different geographic regions of the USA. Recent studies have also reported that many of these isolates may also be fluconazole resistant, leaving few treatment options available for clinicians to use in patients with invasive candidiasis caused by this species. Our understanding of the clinical relevance of specific point mutations within the FKS genes that cause echinocandin resistance and risk factors for the development of microbiologic resistance and clinical failure have also increased. The purpose of this review is to discuss echinocandin resistance in Candida species and recent reports that have increased our understanding of this growing clinical problem.

Clonal Clusters and Virulence Factors of Group C and G Streptococcus Causing Severe Infections, Manitoba, Canada, 2012-2014.

PubMed

Lother, Sylvain A; Demczuk, Walter; Martin, Irene; Mulvey, Michael; Dufault, Brenden; Lagacé-Wiens, Philippe; Keynan, Yoav

2017-07-01

The incidence of group C and G Streptococcus (GCGS) bacteremia, which is associated with severe disease and death, is increasing. We characterized clinical features, outcomes, and genetic determinants of GCGS bacteremia for 89 patients in Winnipeg, Manitoba, Canada, who had GCGS bacteremia during 2012-2014. Of the 89 patients, 51% had bacteremia from skin and soft tissue, 70% had severe disease features, and 20% died. Whole-genome sequencing analysis was performed on isolates derived from 89 blood samples and 33 respiratory sample controls: 5 closely related genetic lineages were identified as being more likely to cause invasive disease than non-clade isolates (83% vs. 57%, p = 0.002). Virulence factors cbp, fbp, speG, sicG, gfbA, and bca clustered clonally into these clades. A clonal distribution of virulence factors may account for severe and fatal cases of bacteremia caused by invasive GCGS.

Utilizing Matrigel Transwell Invasion Assay to Detect and Enumerate Circulating Tumor Cells.

PubMed

Liu, Xingtong; Wu, Xiangwei

2017-01-01

Metastasis is the cause of 90% of human cancer deaths. Circulating tumor cells (CTCs) in the peripheral blood and/or lymphatic vessels are cells shed from primary tumors and considered to be precursors of metastasis. Study of CTCs allows the serial monitoring of tumor progression and may provide predictive and prognostic biomarkers in clinic. Current CTC isolation and detection technologies encounter several challenges, including: heterogeneity of CTCs, low cell viability and/or high rate of contamination post-isolation, and the inability to distinguish viable/invasive from nonviable/nonfunctional CTCs, all of which can limit in vitro and in vivo characterization of CTCs. Here, we describe a new method to detect and enumerate of CTCs based on their invasive property.

Epidemiology of Invasive Group A Streptococcal Disease in Alaska, 2001 to 2013

PubMed Central

Bruce, Michael G.; Bruden, Dana; Zulz, Tammy; Reasonover, Alisa; Hurlburt, Debby; Hennessy, Thomas

2015-01-01

The Arctic Investigations Program (AIP) began surveillance for invasive group A streptococcal (GAS) infections in Alaska in 2000 as part of the invasive bacterial diseases population-based laboratory surveillance program. Between 2001 and 2013, there were 516 cases of GAS infection reported, for an overall annual incidence of 5.8 cases per 100,000 persons with 56 deaths (case fatality rate, 10.7%). Of the 516 confirmed cases of invasive GAS infection, 422 (82%) had isolates available for laboratory analysis. All isolates were susceptible to penicillin, cefotaxime, and levofloxacin. Resistance to tetracycline, erythromycin, and clindamycin was seen in 11% (n = 8), 5.8% (n = 20), and 1.2% (n = 4) of the isolates, respectively. A total of 51 emm types were identified, of which emm1 (11.1%) was the most prevalent, followed by emm82 (8.8%), emm49 (7.8%), emm12 and emm3 (6.6% each), emm89 (6.2%), emm108 (5.5%), emm28 (4.7%), emm92 (4%), and emm41 (3.8%). The five most common emm types accounted for 41% of isolates. The emm types in the proposed 26-valent and 30-valent vaccines accounted for 56% and 78% of all cases, respectively. GAS remains an important cause of invasive bacterial disease in Alaska. Continued surveillance of GAS infections will help improve understanding of the epidemiology of invasive disease, with an impact on disease control, notification of outbreaks, and vaccine development. PMID:26560536

Inherited CARD9 deficiency in otherwise healthy children and adults with meningo-encephalitis and/or colitis caused by Candida

PubMed Central

Lanternier, Fanny; Mahdaviani, Seyed Alireza; Barbati, Elisa; Chaussade, Hélène; Koumar, Yatrika; Levy, Romain; Denis, Blandine; Brunel, Anne-Sophie; Martin, Sophie; Loop, Michèle; Peeters, Julie; de Selys, Ariel; Vanclaire, Jean; Vermylen, Christiane; Nassogne, Marie-Cécile; Chatzis, Olga; Liu, Luyan; Migaud, Mélanie; Pedergnana, Vincent; Desoubeaux, Guillaume; Jouvion, Gregory; Chretien, Fabrice; Darazam, Ilad Alavi; Schäffer, Alejandro A.; Netea, Mihai G.; De Bruycker, Jean-Jacques; Bernard, Louis; Reynes, Jacques; Amazrine, Noureddine; Abel, Laurent; Van der Linden, Dimitri; Harrison, Tom; Picard, Capucine; Lortholary, Olivier; Mansouri, Davood; Casanova, Jean-Laurent; Puel, Anne

2016-01-01

Invasive infections of the central nervous system or digestive tract caused by commensal fungi of the genus Candida are rare and life-threatening. The known risk factors include acquired and inherited immunodeficiencies, with patients often displaying a history of multiple infections. Cases of meningo-encephalitis and/or colitis caused by Candida remain unexplained. We studied five previously healthy children and adults with unexplained invasive disease of the central nervous system, or the digestive tract, or both, caused by Candida spp. The patients were aged 39, 7, 17 37, and 26 years at the time of infection and were unrelated but each born to consanguineous parents of Turkish (two patients), Iranian, Moroccan or Pakistani origin. Meningo-encephalitis was isolated in three patients, associated with colitis in a fourth patient, and the fifth patient suffered from isolated colitis. Inherited CARD9 deficiency was recently reported in otherwise healthy patients with other forms of severe disease caused by Candida, Trichophyton, Phialophora, and Exophiala, including meningo-encephalitis, but not colitis, caused by Candida and Exophiala. We therefore sequenced CARD9 in the five patients. All were found to be homozygous for rare and deleterious mutant CARD9 alleles: R70W and Q289* for the three patients with isolated C. albicans meningo-encephalitis, R35Q for the patient with meningo-encephalitis and colitis caused by C. glabrata, and Q295* for the patient with C. albicans colitis. Regardless of their levels of mutant CARD9 protein, the patients’ monocyte-derived dendritic cells responded poorly to CARD9-dependent fungal agonists (curdlan, heat-killed C. albicans, Saccharomyces cerevisiae and Exophiala dermatitidis). Invasive infections of the CNS or digestive tract caused by Candida in previously healthy children and even adults may be caused by inherited CARD9 deficiency. PMID:25702837

Invasive Aspergillus niger complex infections in a Belgian tertiary care hospital.

PubMed

Vermeulen, E; Maertens, J; Meersseman, P; Saegeman, V; Dupont, L; Lagrou, K

2014-05-01

The incidence of invasive infections caused by the Aspergillus niger species complex was 0.043 cases/10 000 patient-days in a Belgian university hospital (2005-2011). Molecular typing was performed on six available A. niger complex isolates involved in invasive disease from 2010 to 2011, revealing A. tubingensis, which has higher triazole minimal inhibitory concentrations, in five out of six cases. © 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.

Increased incidence of invasive group A streptococcal infections in Sweden, January 2012-February 2013.

PubMed

Darenberg, J; Henriques-Normark, B; Lepp, T; Tegmark-Wisell, K; Tegnell, A; Widgren, K

2013-04-04

The incidence of invasive group A streptococcal infections in Sweden was 6.1 per 100,000 population in 2012, the highest since the disease became notifiable in 2004. Furthermore, January and February 2013 marked a dramatic increase of cases notified, partly explainable by an increase of emm1/T1 isolates, a type previously shown to cause severe invasive disease more often than other types. Healthcare providers in Sweden and health authorities in neighbouring countries have been informed about this increase.

Nursing home outbreak of invasive group a streptococcal infections caused by 2 distinct strains.

PubMed

Thigpen, Michael C; Thomas, D Michael; Gloss, David; Park, Sarah Y; Khan, Amy J; Fogelman, Vicky L; Beall, Bernard; Van Beneden, Chris A; Todd, Randall L; Greene, Carolyn M

2007-01-01

To identify factors contributing to a cluster of deaths from invasive group A streptococcus (GAS) infection in a nursing home facility and to prevent additional cases. Outbreak investigation. A 146-bed nursing home facility in northern Nevada. We defined a case as the isolation of GAS from a normally sterile site in a resident of nursing home A. To identify case patients, we reviewed resident records from nursing home A, the local hospital, and the hospital laboratory. We obtained oropharyngeal and skin lesion swabs from staff and residents to assess GAS colonization and performed emm typing on available isolates. To identify potential risk factors for transmission, we performed a cohort study and investigated concurrent illness among residents and surveyed staff regarding infection control practices. Six residents met the case patient definition; 3 (50%) of them died. Among invasive GAS isolates available for analysis, 2 distinct strains were identified: emm11 (3 isolates) and emm89 (2 isolates). The rate of GAS carriage was 6% among residents and 4% among staff; carriage isolates were emm89 (8 isolates), emm11 (2 isolates), and emm1 (1 isolate). Concurrently, 35 (24%) of the residents developed a respiratory illness of unknown etiology; 41% of these persons died. Twenty-one (30%) of the surveyed employees did not always wash their hands before patient contacts, and 27 (38%) did not always wash their hands between patient contacts. Concurrent respiratory illness likely contributed to an outbreak of invasive GAS infection from 2 strains in a highly susceptible population. This outbreak highlights the importance of appropriate infection control measures, including respiratory hygiene practices, in nursing home facilities.

Life history, population viability, and the potential for local adaptation in isolated trout populations

Treesearch

K. J. Carim; Y. Vindenes; L. A. Eby; C. Barfoot; L. A. Vollestad

2017-01-01

Habitat loss and fragmentation have caused population decline across taxa through impacts on life history diversity, dispersal patterns, and gene flow. Yet, intentional isolation of native fish populations is a frequently used management strategy to protect against negative interactions with invasive fish species. We evaluated the population viability and genetic...

Isolation of Primary Mouse Trophoblast Cells and Trophoblast Invasion Assay

PubMed Central

Pennington, Kathleen A.; Schlitt, Jessica M.; Schulz, Laura C.

2012-01-01

The placenta is responsible for the transport of nutrients, gasses and growth factors to the fetus, as well as the elimination of wastes. Thus, defects in placental development have important consequences for the fetus and mother, and are a major cause of embryonic lethality. The major cell type of the fetal portion of the placenta is the trophoblast. Primary mouse placental trophoblast cells are a useful tool for studying normal and abnormal placental development, and unlike cell lines, may be isolated and used to study trophoblast at specific stages of pregnancy. In addition, primary cultures of trophoblast from transgenic mice may be used to study the role of particular genes in placental cells. The protocol presented here is based on the description by Thordarson et al.1, in which a percoll gradient is used to obtain a relatively pure trophoblast cell population from isolated mouse placentas. It is similar to the more widely used methods for human trophoblast cell isolation2-3. Purity may be assessed by immunocytochemical staining of the isolated cells for cytokeratin 74. Here, the isolated cells are then analyzed using a matrigel invasion assay to assess trophoblast invasiveness in vitro5-6. The invaded cells are analyzed by immunocytochemistry and stained for counting. PMID:22257865

Strategic removal of host trees in isolated, satellite infestations of emerald ash borer can reduce population growth

Treesearch

Samuel J. Fahrner; Mark Abrahamson; Robert C. Venette; Brian H. Aukema

2017-01-01

Emerald ash borer is an invasive beetle causing significant mortality of ash trees (Fraxinus spp.) in North America and western Russia. The invasive range has expanded to more than half of the states in the United States since the initial detection in Michigan, USA in 2002. Emerald ash borer is typically managed with a combination of techniques...

Bipolaris microstegii

Treesearch

Andrew M. Minnis; Amy Y. Rossman; Nathan M. Kleczewski; S. Luke. Flory

2012-01-01

Many species of Bipolaris are important pathogens of grasses. This new species was isolated from Microstegium vimineum, an invasive plant in the USA. The fungus causes disease on Microstegium, but it also infects a wider range of hosts.

Epidemiological Study of Fusarium Species Causing Invasive and Superficial Fusariosis in Japan.

PubMed

Muraosa, Yasunori; Oguchi, Misato; Yahiro, Maki; Watanabe, Akira; Yaguchi, Takashi; Kamei, Katsuhiko

2017-01-01

In Japan, Fusarium species are known etiological agents of human fungal infection; however, there has been no report of a large-scale epidemiological study on the etiological agents of fusariosis. A total of 73 Fusarium isolates from patients with invasive fusariosis (IF, n= 36) or superficial fusariosis (SF, n= 37), which were obtained at hospitals located in 28 prefectures in Japan between 1998 and 2015, were used for this study. Fusarium isolates were identified using Fusarium- and Fusarium solani species complex (FSSC) -specific real-time PCR and partial DNA sequences of the elongation factor-1 alpha (EF-1α) gene and the nuclear ribosomal internal transcribed spacer (ITS) region. FSSC was predominately isolated from both patients with IF and SF (IF, 77.8% and SF, 67.6%). Distribution of the phylogenetic species of FSSC isolates from patients with IF and SF exhibited different spectra; specifically, F. keratoplasticum (FSSC 2) (25.0%) was the most frequent isolate from patients with IF, whereas F. falciforme (FSSC 3+4) (32.4%) was the most frequent isolate from patients with SF. Fusarium sp. (FSSC 5) was the second most frequent isolate from both patients with IF and SF (IF, 22.2% and SF, 24.3%). Notably, F. petroliphilum (FSSC 1) was isolated only from patients with IF. Each species was isolated from a broad geographic area, and an epidemic was not observed. This is the first epidemiological study of Fusarium species causing IF and SF in Japan.

Infections Caused by Fusarium Species in Pediatric Cancer Patients and Review of Published Literature.

PubMed

Arnoni, Mariana Volpe; Paula, Claudete Rodrigues; Auler, Marcos Ereno; Simões, Cirilo Cesar Naozuka; Nakano, Shirley; Szeszs, Maria Walderez; Melhem, Márcia de Souza Carvalho; Pereira, Virgínia Bodelão Richini; Garces, Hans Garcia; Bagagli, Eduardo; Silva, Eriques Gonçalves; de Macêdo, Melissa Ferreira; Ruiz, Luciana da Silva

2018-03-21

Fusarium species have emerged as responsible for a broad spectrum of infections, including superficial, locally invasive and disseminated ones, especially in the hospital environment. Since there are few reports of invasive and disseminated fusariosis in children, the aim of this study was to report four cases of nosocomial infection caused by this microorganism in children with cancer hospitalized in a public children's hospital located in Brazil. Two of these patients were female and two were male. All patients presented febrile neutropenia, while three patients had acute lymphocytic leukemia and one patient had Wilms' tumor as underlying disease. In two cases, fungi were isolated from blood and identified as Fusarium oxysporum species complex after phenotypic and genotypic studies, while in two other cases fungi were isolated from skin biopsies and identified as Fusarium solani species complex. One patient died 12 days after the onset of cutaneous lesions. All isolates, after susceptibility testing, presented high levels of minimum inhibitory concentration for itraconazole, voriconazole and amphotericin B. Considering the emergence of filamentous fungi as etiologic agents of nosocomial infections, health professionals should be aware of the problems these infections, especially fungal ones, may cause to debilitated patients.

Changes in the features of invasive pneumococcal disease after introduction of the seven-valent pneumococcal conjugate vaccine in a regional core hospital of Kochi, Japan.

PubMed

Miyahara, Hiroyuki; Maruyama, Hidehiko; Kanazawa, Akane; Iwasaki, Yuka; Shigemitsu, Yusuke; Watanabe, Hirokazu; Tokorodani, Chiho; Miyazawa, Mari; Nakata, Yusei; Nishiuchi, Ritsuo; Kikkawa, Kiyoshi

2015-01-01

Since the introduction of the seven-valent pneumococcal conjugate vaccine (PCV7) in 2007, invasive pneumococcal disease has declined, but the incidence of Streptococcus pneumoniae serotype 19A has risen worldwide. The present study examined changes in the features of invasive pneumococcal disease since the introduction of the PCV7 in Kochi, Japan. Pediatric cases of invasive pneumococcal disease were investigated before and after vaccine introduction (January 2008 to December 2013). Cases of invasive pneumococcal disease tended to decrease after PCV7 introduction. In addition, before introduction of the vaccine, most serotypes causing invasive pneumococcal disease were those included in the vaccine. However, after the introduction, we found cases infected by serotypes not covered by vaccine. Penicillin-resistant S. pneumoniae was the predominant serotype causing invasive pneumococcal disease before introduction of the PCV7, and the susceptibility of this serotype to antibiotics improved after vaccine introduction. Serotype isolates identified after vaccine introduction were also relatively susceptible to antibiotic therapy, but decreased susceptibility is expected.

Responses of soil N-fixing bacteria communities to invasive plant species under different types of simulated acid deposition

NASA Astrophysics Data System (ADS)

Wang, Congyan; Zhou, Jiawei; Jiang, Kun; Liu, Jun; Du, Daolin

2017-06-01

Biological invasions have incurred serious threats to native ecosystems in China, and soil N-fixing bacteria communities (SNB) may play a vital role in the successful plant invasion. Meanwhile, anthropogenic acid deposition is increasing in China, which may modify or upgrade the effects that invasive plant species can cause on SNB. We analyzed the structure and diversity of SNB by means of new generation sequencing technology in soils with different simulated acid deposition (SAD), i.e., different SO4 2- to NO3 - ratios, and where the invasive ( Amaranthus retroflexus L.) and the native species ( Amaranthus tricolor L.) grew mixed or isolated for 3 months. A. retroflexus itself did not exert significant effects on the diversity and richness of SNB but did it under certain SO4 2- to NO3 - ratios. Compared to soils where the native species grew isolated, the soils where the invasive A. retroflexus grew isolated showed lower relative abundance of some SNB classes under certain SAD treatments. Some types of SAD can alter soil nutrient content which in turn could affect SNB diversity and abundance. Specifically, greater SO4 2- to NO3 - ratios tended to have more toxic effects on SNB likely due to the higher exchange capacity of hydroxyl groups (OH-) between SO4 2- and NO3 -. As a conclusion, it can be expected a change in the structure of SNB after A. retroflexus invasion under acid deposition rich in sulfuric acid. This change may create a plant soil feedback favoring future A. retroflexus invasions.

Responses of soil N-fixing bacteria communities to invasive plant species under different types of simulated acid deposition.

PubMed

Wang, Congyan; Zhou, Jiawei; Jiang, Kun; Liu, Jun; Du, Daolin

2017-06-01

Biological invasions have incurred serious threats to native ecosystems in China, and soil N-fixing bacteria communities (SNB) may play a vital role in the successful plant invasion. Meanwhile, anthropogenic acid deposition is increasing in China, which may modify or upgrade the effects that invasive plant species can cause on SNB. We analyzed the structure and diversity of SNB by means of new generation sequencing technology in soils with different simulated acid deposition (SAD), i.e., different SO 4 2- to NO 3 - ratios, and where the invasive (Amaranthus retroflexus L.) and the native species (Amaranthus tricolor L.) grew mixed or isolated for 3 months. A. retroflexus itself did not exert significant effects on the diversity and richness of SNB but did it under certain SO 4 2- to NO 3 - ratios. Compared to soils where the native species grew isolated, the soils where the invasive A. retroflexus grew isolated showed lower relative abundance of some SNB classes under certain SAD treatments. Some types of SAD can alter soil nutrient content which in turn could affect SNB diversity and abundance. Specifically, greater SO 4 2- to NO 3 - ratios tended to have more toxic effects on SNB likely due to the higher exchange capacity of hydroxyl groups (OH - ) between SO 4 2- and NO 3 - . As a conclusion, it can be expected a change in the structure of SNB after A. retroflexus invasion under acid deposition rich in sulfuric acid. This change may create a plant soil feedback favoring future A. retroflexus invasions.

Clonal Structure and Characterization of Staphylococcus aureus Strains from Invasive Infections in Paediatric Patients from South Poland: Association between Age, spa Types, Clonal Complexes, and Genetic Markers

PubMed Central

Ilczyszyn, Weronika M.; Sabat, Artur J.; Akkerboom, Viktoria; Szkarlat, Anna; Klepacka, Joanna; Sowa-Sierant, Iwona; Wasik, Barbara; Kosecka-Strojek, Maja; Buda, Aneta; Miedzobrodzki, Jacek; Friedrich, Alexander W.

2016-01-01

The aim of current study was to examine clonal structure and genetic profile of invasive Staphylococcus aureus isolates recovered from infants and children treated at the Jagiellonian University Children’s Hospital of Krakow, Poland. The 107 invasive S. aureus isolates, collected between February 2012 and August 2014, were analysed retrospectively. Antimicrobial susceptibility testing, spa typing and DNA microarray analysis were performed to determine clonal distribution, diversity and gene content in regard to patients characteristics. In total, 107 isolates were recovered from 88 patients with clinical symptoms of invasive bacterial infection. The final set of 92 non-duplicate samples included 38 MRSA isolates. Additionally, a set of 54 S. aureus isolates collected during epidemiological screening was genotyped and analysed. There were 72 healthcare-associated (HCA) and 20 community-onset (CO) infection events caused by 33 and 5 MRSA isolates, respectively. The majority of isolates were affiliated with the major European clonal complexes CC5 (t003, spa-CC 002), CC45 (spa-CC 015), CC7 or CC15 (t084, t091, spa-CC 084). Two epidemic clones (CC5-MRSA-II or CC45-MRSA-IV) dominated among MRSA isolates, while MSSA population contained 15 different CCs. The epidemiological screening isolates belonged to similar genetic lineages as those collected from invasive infection cases. The HCA infection events, spa types t003, t2642 or CC5 were significantly associated with infections occurring in neonates and children under 5 years of age. Moreover, carriage of several genetic markers, including erm(A), sea (N315), egc-cluster, chp was significantly higher in isolates obtained from children in this age group. The spa types t091 and t008 were underrepresented among patients aged 5 years or younger, whereas spa type t008, CC8 and presence of splE was associated with infection in children aged 10 years or older. The HCA-MRSA strains were most frequently found in children under 5 years, although the majority of invasive infections was associated with MSSA strains. Moreover, an association between age group of children from the study population and a specific strain genotype (spa type, clonal complex or genetic content) was observed among the patients. PMID:26992009

Phylogenetics of a fungal invasion: Origins and widespread dispersal of white-nose syndrome

USGS Publications Warehouse

Drees, Kevin P.; Lorch, Jeffrey M.; Puechmaille, Sebastein J.; Parise, Katy L.; Wibbelt, Gudrun; Hoyt, Joseph R.; Sun, Keping; Jargalsaikhan, Ariunbold; Dalannast, Munkhnast; Palmer, Jonathan M.; Linder, Daniel L.; Kilpatrick, Marm; Pearson, Talima; Keim, Paul S.; Blehert, David; Foster, Jeffrey T.

2017-01-01

Globalization has facilitated the worldwide movement and introduction of pathogens, but epizoological reconstructions of these invasions are often hindered by limited sampling and insufficient genetic resolution among isolates. Pseudogymnoascus destructans, a fungal pathogen causing the epizootic of white-nose syndrome in North American bats, has exhibited few genetic polymorphisms in previous studies, presenting challenges for both epizoological tracking of the spread of this fungus and for determining its evolutionary history. We used single nucleotide polymorphisms (SNPs) from whole-genome sequencing and microsatellites to construct high-resolution phylogenies of P. destructans. Shallow genetic diversity and the lack of geographic structuring among North American isolates support a recent introduction followed by expansion via clonal reproduction across the epizootic zone. Moreover, the genetic relationships of isolates within North America suggest widespread mixing and long-distance movement of the fungus. Genetic diversity among isolates of P. destructans from Europe was substantially higher than in those from North America. However, genetic distance between the North American isolates and any given European isolate was similar to the distance between the individual European isolates. In contrast, the isolates we examined from Asia were highly divergent from both European and North American isolates. Although the definitive source for introduction of the North American population has not been conclusively identified, our data support the origin of the North American invasion by P. destructans from Europe rather than Asia.

Phylogenetics of a Fungal Invasion: Origins and Widespread Dispersal of White-Nose Syndrome

PubMed Central

Drees, Kevin P.; Lorch, Jeffrey M.; Puechmaille, Sebastien J.; Parise, Katy L.; Wibbelt, Gudrun; Hoyt, Joseph R.; Sun, Keping; Jargalsaikhan, Ariunbold; Dalannast, Munkhnast; Lindner, Daniel L.; Marm Kilpatrick, A.; Pearson, Talima; Blehert, David S.

2017-01-01

ABSTRACT Globalization has facilitated the worldwide movement and introduction of pathogens, but epizoological reconstructions of these invasions are often hindered by limited sampling and insufficient genetic resolution among isolates. Pseudogymnoascus destructans, a fungal pathogen causing the epizootic of white-nose syndrome in North American bats, has exhibited few genetic polymorphisms in previous studies, presenting challenges for both epizoological tracking of the spread of this fungus and for determining its evolutionary history. We used single nucleotide polymorphisms (SNPs) from whole-genome sequencing and microsatellites to construct high-resolution phylogenies of P. destructans. Shallow genetic diversity and the lack of geographic structuring among North American isolates support a recent introduction followed by expansion via clonal reproduction across the epizootic zone. Moreover, the genetic relationships of isolates within North America suggest widespread mixing and long-distance movement of the fungus. Genetic diversity among isolates of P. destructans from Europe was substantially higher than in those from North America. However, genetic distance between the North American isolates and any given European isolate was similar to the distance between the individual European isolates. In contrast, the isolates we examined from Asia were highly divergent from both European and North American isolates. Although the definitive source for introduction of the North American population has not been conclusively identified, our data support the origin of the North American invasion by P. destructans from Europe rather than Asia. PMID:29233897

Whole genome typing of the recently emerged Canadian serogroup W Neisseria meningitidis sequence type 11 clonal complex isolates associated with invasive meningococcal disease.

PubMed

Tsang, Raymond S W; Ahmad, Tauqeer; Tyler, Shaun; Lefebvre, Brigitte; Deeks, Shelley L; Gilca, Rodica; Hoang, Linda; Tyrrell, Gregory; Van Caeseele, Paul; Van Domselaar, Gary; Jamieson, Frances B

2018-04-01

This study was performed to analyze the Canadian invasive serogroup W Neisseria meningitidis (MenW) sequence type 11 (ST-11) clonal complex (CC) isolates by whole genome typing and to compare Canadian isolates with similar isolates from elsewhere. Whole genome typing of 30 MenW ST-11 CC, 20 meningococcal group C (MenC) ST-11 CC, and 31 MenW ST-22 CC isolates was performed on the Bacterial Isolate Genome Sequence database platform. Canadian MenW ST-11 CC isolates were compared with the 2000 MenW Hajj outbreak strain, as well as with MenW ST-11 CC from other countries. Whole genome typing showed that the Canadian MenW ST-11 CC isolates were distinct from the traditional MenW ST-22 CC; they were not capsule-switched contemporary MenC strains that incorporated MenW capsules. While some recent MenW disease cases in Canada were caused by MenW ST-11 CC isolates showing relatedness to the 2000 MenW Hajj strain, many were non-Hajj isolates similar to current MenW ST-11 isolates found globally. Geographical and temporal variations in genotypes and surface protein antigen genes were found among the MenW ST-11 CC isolates. The current MenW ST-11 isolates did not arise by capsule switching from contemporary MenC ST-11 isolates. Both the Hajj-related and non-Hajj MenW ST-11 CC strains were associated with invasive meningococcal disease in Canada. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

A cluster of invasive meningococcal disease (IMD) caused by Neisseria meningitidis serogroup W among university students, France, February to May 2017

PubMed Central

Bassi, Clément; Taha, Muhamed-Kheir; Merle, Christian; Hong, Eva; Lévy-Bruhl, Daniel; Barret, Anne-Sophie; Mounchetrou Njoya, Ibrahim

2017-01-01

Between February and May 2017, two cases of invasive meningococcal disease caused by a new, rapidly expanding serogroup W meningococci variant were reported among students of an international university in Paris. Bacteriological investigations showed that isolates shared identical genotypic formula (W:P1.5,2:F1–1:cc11) and belonged to the South American/UK lineage. A vaccination campaign was organised that aimed at preventing new cases linked to potential persistence of the circulation of the bacteria in the students. PMID:28749333

Luliconazole, an alternative antifungal agent against Aspergillus terreus.

PubMed

Zargaran, M; Taghipour, S; Kiasat, N; Aboualigalehdari, E; Rezaei-Matehkolaei, A; Zarei Mahmoudabadi, A; Shamsizadeh, F

2017-09-01

Aspergillus terreus is the fourth leading cause of invasive and non-invasive aspergillosis and one of the causative agents of morbidity and mortality among immunocompromised and high-risk patients. A. terreus appears to have increased as a cause of opportunistic fungal infections from superficial to serious invasive infections. Although, invasive aspergillosis is often treated empirically with amphotericin B, most A. terreus isolates are resistant both in vivo and in vitro to some antifungal drugs. In this study, we aimed to evaluate antifungals susceptibility profiles of the different strains of A. terreus against amphotericin B, caspofungin, fluconazole, voriconazole, posaconazole and luliconazole. Forty A. terreus strains originating from environmental sources (air and soil) were identified using by macroscopic and microscopic features. Six antifungals including, amphotericin B, caspofungin, fluconazole, voriconazole, posaconazole and luliconazole were applied for susceptibility tests. Our results show that tested isolates had different susceptibility to antifungals. The lowest MIC GM related to luliconazole (0.00236μg/ml), followed by posaconazole (0.18621μg/ml), voriconazole (0.22925μg/ml), caspofungin (0.86μg/ml), fluconazole (8μg/ml) and amphotericin B (11.12μg/ml). This study demonstrated that luliconazole had an excellent in vitro activity against all tested isolates of A. terreus, with MIC GM 0.00236μg/mL than other tested antifungals. As a result, luliconazole could be a possible alternative antifungal for the treatment of aspergillosis due to A. terreus. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Trend in vancomycin susceptibility and correlation with molecular characteristics of methicillin-resistant Staphylococcus aureus causing invasive infections in Taiwan: results from the Tigecycline in vitro Surveillance in Taiwan (TIST) study, 2006-2010.

PubMed

Tsao, Shin-Ming; Wang, Wei-Yao; Ko, Wen-Chien; Huang, Cheng-Hua; Lu, Chin-Te; Chuang, Yin-Ching; Liu, Chia-Ying; Liao, Chun-Hsing; Chen, Yao-Shen; Liu, Yung-Ching; Chen, Wei-Yu; Jang, Tsrang-Neng; Lin, Hsiu-Chen; Chen, Chih-Ming; Shi, Zhi-Yuan; Pan, Sung-Ching; Yang, Jia-Ling; Kung, Hsiang-Chi; Liu, Chun-Eng; Cheng, Yu-Jen; Liu, Jien-Wei; Sun, Wu; Wang, Lih-Shinn; Yu, Kwok-Woon; Chiang, Ping-Cherng; Lee, Ming-Hsun; Lee, Chun-Ming; Hsu, Gwo-Jong; Chen, Yen-Hsu; Lu, Po-Liang; Thomas, Chang-Yao Tsao; Hsueh, Po-Ren

2014-10-01

This study was intended to investigate the trend in vancomycin susceptibility and correlation with molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) causing invasive infections. A total of 670 MRSA isolates were collected from patients with invasive infections as part of bacterial collection in the Tigecycline in vitro Surveillance in Taiwan (TIST) from 2006 to 2010. MICs of the isolates to vancomycin were determined using the agar dilution method. Characteristics of staphylococcal cassette chromosome mec (SCCmec), mec-associated hypervariable region (dru), and accessory gene regulator (agr) of the isolates were identified by polymerase chain reaction methods. MRSA isolates with SCCmec types I, II, and III were molecularly defined as hospital-associated MRSA (HA-MRSA), and those with SCCmec types IV, V, and VT were assigned as community-associated MRSA (CA-MRSA). All but 1 MRSA isolates exhibited vancomycin MICs ≤1 mg/L. A declining trend in vancomycin MICs among MRSA isolates was noted, which was associated with the decline in proportion of HA-MRSA. The percentage of CA-MRSA increased from 25.6% in 2006 to 46.0% in 2010. An increase in the geometric mean of vancomycin MICs was found in MRSA with particular molecular types such as SCCmec types II and III, agr groups I and II, and dru10-14. A significant correlation among particular molecular types was found, including SCCmecII-agr group II-dru4, SCCmecIII-agr group I-dru11-14, SCCmecIV-agr group II-dru9, and SCCmecVT-agr group I-dru9 and dru11. There was no vancomycin creep among MRSA isolates, and the declining trend of vancomycin MIC against MRSA was attributed to the increasing prevalence of CA-MRSA over time. Copyright © 2014 Elsevier Inc. All rights reserved.

In Vitro Interaction of Terbinafine with Itraconazole against Clinical Isolates of Scedosporium prolificans

PubMed Central

Meletiadis, Joseph; Mouton, Johan W.; Rodriguez-Tudela, Juan L.; Meis, Jacques F. G. M.; Verweij, Paul E.

2000-01-01

In order to develop new approaches for the chemotherapy of invasive infections caused by Scedosporium prolificans, the in vitro interaction between itraconazole and terbinafine against 20 clinical isolates was studied using a checkerboard microdilution method. Itraconazole and terbinafine alone were inactive against most isolates, but the combination was synergistic against 95 and 85% of isolates after 48 and 72 h of incubation, respectively. Antagonism was not observed. The MICs obtained with the terbinafine-itraconazole combination were within levels that can be achieved in plasma. PMID:10639389

Morphological and Genetic Analyses of the Invasive Forest Pathogen Phytophthora austrocedri Reveal that Two Clonal Lineages Colonized Britain and Argentina from a Common Ancestral Population.

PubMed

Henricot, Béatrice; Pérez-Sierra, Ana; Armstrong, April C; Sharp, Paul M; Green, Sarah

2017-12-01

Phytophthora austrocedri is causing widespread mortality of Austrocedrus chilensis in Argentina and Juniperus communis in Britain. The pathogen has also been isolated from J. horizontalis in Germany. Isolates from Britain, Argentina, and Germany are homothallic, with no clear differences in the dimensions of sporangia, oogonia, or oospores. Argentinian and German isolates grew faster than British isolates across a range of media and had a higher temperature tolerance, although most isolates, regardless of origin, grew best at 15°C and all isolates were killed at 25°C. Argentinian and British isolates caused lesions when inoculated onto both A. chilensis and J. communis; however, the Argentinian isolate caused longer lesions on A. chilensis than on J. communis and vice versa for the British isolate. Genetic analyses of nuclear and mitochondrial loci showed that all British isolates are identical. Argentinian isolates and the German isolate are also identical but differ from the British isolates. Single-nucleotide polymorphisms are shared between the British and Argentinian isolates. We concluded that British isolates and Argentinian isolates conform to two distinct clonal lineages of P. austrocedri founded from the same as-yet-unidentified source population. These lineages should be recognized and treated as separate risks by international plant health legislation.

Molecular characterization of invasive Streptococcus dysgalactiae subsp. equisimilis. Multicenter study: Argentina 2011-2012.

PubMed

Traverso, Fernando; Blanco, Alejandra; Villalón, Pilar; Beratz, Noelia; Sáez Nieto, Juan Antonio; Lopardo, Horacio

Streptococcus dysgalactiae subsp. equisimilis (SDSE) has virulence factors similar to those of Streptococcus pyogenes. Therefore, it causes pharyngitis and severe infections indistinguishable from those caused by the classic pathogen. The objectives of this study were: to know the prevalence of SDSE invasive infections in Argentina, to study the genetic diversity, to determine the presence of virulence genes, to study antibiotic susceptibility and to detect antibiotic resistance genes. Conventional methods of identification were used. Antibiotic susceptibility was determined by the disk diffusion and the agar dilution methods and the E-test. Twenty eight centers from 16 Argentinean cities participated in the study. Twenty three isolates (16 group G and 7 group C) were obtained between July 1 2011 and June 30 2012. Two adult patients died (8.7%). Most of the isolates were recovered from blood (60.9%). All isolates carried speJ and ssa genes. stG62647, stG653 and stG840 were the most frequent emm types. Nineteen different PFGE patterns were detected. All isolates were susceptible to penicillin and levofloxacin, 6 (26.1%) showed resistance or reduced susceptibility to erythromycin [1 mef(A), 3 erm(TR), 1 mef(A)+erm(TR) and 1 erm(TR)+erm(B)] and 7 (30.4%) were resistant or exhibited reduced susceptibility to tetracycline [2 tet(M), 5 tet(M)+tet(O)]. The prevalence in Argentina was of at least 23 invasive infections by SDSE. A wide genetic diversity was observed. All isolates carried speJ and ssa genes. Similarly to other studies, macrolide resistance (26.1%) was mainly associated to the MLS B phenotype. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Phylogenetics of a Fungal Invasion: Origins and Widespread Dispersal of White-Nose Syndrome.

PubMed

Drees, Kevin P; Lorch, Jeffrey M; Puechmaille, Sebastien J; Parise, Katy L; Wibbelt, Gudrun; Hoyt, Joseph R; Sun, Keping; Jargalsaikhan, Ariunbold; Dalannast, Munkhnast; Palmer, Jonathan M; Lindner, Daniel L; Marm Kilpatrick, A; Pearson, Talima; Keim, Paul S; Blehert, David S; Foster, Jeffrey T

2017-12-12

Globalization has facilitated the worldwide movement and introduction of pathogens, but epizoological reconstructions of these invasions are often hindered by limited sampling and insufficient genetic resolution among isolates. Pseudogymnoascus destructans , a fungal pathogen causing the epizootic of white-nose syndrome in North American bats, has exhibited few genetic polymorphisms in previous studies, presenting challenges for both epizoological tracking of the spread of this fungus and for determining its evolutionary history. We used single nucleotide polymorphisms (SNPs) from whole-genome sequencing and microsatellites to construct high-resolution phylogenies of P. destructans Shallow genetic diversity and the lack of geographic structuring among North American isolates support a recent introduction followed by expansion via clonal reproduction across the epizootic zone. Moreover, the genetic relationships of isolates within North America suggest widespread mixing and long-distance movement of the fungus. Genetic diversity among isolates of P. destructans from Europe was substantially higher than in those from North America. However, genetic distance between the North American isolates and any given European isolate was similar to the distance between the individual European isolates. In contrast, the isolates we examined from Asia were highly divergent from both European and North American isolates. Although the definitive source for introduction of the North American population has not been conclusively identified, our data support the origin of the North American invasion by P. destructans from Europe rather than Asia. IMPORTANCE This phylogenetic study of the bat white-nose syndrome agent, P. destructans , uses genomics to elucidate evolutionary relationships among populations of the fungal pathogen to understand the epizoology of this biological invasion. We analyze hypervariable and abundant genetic characters (microsatellites and genomic SNPs, respectively) to reveal previously uncharacterized diversity among populations of the pathogen from North America and Eurasia. We present new evidence supporting recent introduction of the fungus to North America from a diverse Eurasian population, with limited increase in genetic variation in North America since that introduction. Copyright © 2017 Drees et al.

Haemophilus influenzae serotype e meningitis in an adult.

PubMed

Ulu-Kilic, Ayşegül; Kiliç, Ayşegül Ulu; Altay, Fatma Aybala; Gürbüz, Yunus; Otgun, Selin Nar; Sencan, Irfan

2010-05-01

The incidence of Haemophilus influenzae type b (Hib) invasive disease has declined significantly in countries with routine infant Hib immunization. Accordingly, infections caused by other H. influenzae serotypes or by encapsulated H. influenzae strains are of growing interest. H. influenzae serotype e (Hie) is a rare cause of infection. Invasive Hie infections reported in adults are generally in individuals who had previous underlying conditions, in contrast to infections in childhood. We present the first report of Hie meningitis in Turkey. It is of interest that meningitis due to this organism occured as a complication of transsphenoidal hypophysectomy, which to our knowledge has never been documented. Further identification of H. influenzae strains isolated from patients with invasive disease, especially those with predisposing factors and/or who have been vaccinated, is essential.

Lipooligosaccharide Structures of Invasive and Carrier Isolates of Neisseria meningitidis Are Correlated with Pathogenicity and Carriage*

PubMed Central

John, Constance M.; Phillips, Nancy J.; Din, Richard; Liu, Mingfeng; Rosenqvist, Einar; Høiby, E. Arne; Stein, Daniel C.; Jarvis, Gary A.

2016-01-01

The degree of phosphorylation and phosphoethanolaminylation of lipid A on neisserial lipooligosaccharide (LOS), a major cell-surface antigen, can be correlated with inflammatory potential and the ability to induce immune tolerance in vitro. On the oligosaccharide of the LOS, the presence of phosphoethanolamine and sialic acid substituents can be correlated with in vitro serum resistance. In this study, we analyzed the structure of the LOS from 40 invasive isolates and 25 isolates from carriers of Neisseria meningitidis without disease. Invasive strains were classified as groups 1–3 that caused meningitis, septicemia without meningitis, and septicemia with meningitis, respectively. Intact LOS was analyzed by high resolution matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Prominent peaks for lipid A fragment ions with three phosphates and one phosphoethanolamine were detected in all LOS analyzed. LOS from groups 2 and 3 had less abundant ions for highly phosphorylated lipid A forms and induced less TNF-α in THP-1 monocytic cells compared with LOS from group 1. Lipid A from all invasive strains was hexaacylated, whereas lipid A of 6/25 carrier strains was pentaacylated. There were fewer O-acetyl groups and more phosphoethanolamine and sialic acid substitutions on the oligosaccharide from invasive compared with carrier isolates. Bioinformatic and genomic analysis of LOS biosynthetic genes indicated significant skewing to specific alleles, dependent on the disease outcome. Our results suggest that variable LOS structures have multifaceted effects on homeostatic innate immune responses that have critical impact on the pathophysiology of meningococcal infections. PMID:26655715

Molecular genetic evidence for the involvement of a specific polygalacturonase, P2c, in the invasion and spread of Aspergillus flavus in cotton bolls.

PubMed Central

Shieh, M T; Brown, R L; Whitehead, M P; Cary, J W; Cotty, P J; Cleveland, T E; Dean, R A

1997-01-01

Isolates of Aspergillus flavus can be differentiated based on production of the polygalacturonase P2c. One group of isolates produces P2c, whereas the other group does not. In general, the group that produces P2c causes more damage and spreads to a greater extent in cotton bolls than those isolates that do not produce P2c. To determine whether P2c contributes to disease, the expression of pecA, the gene previously determined to encode P2c, was genetically altered. Adding the pecA gene to a strain previously lacking the gene resulted in the ability to cause significantly more damage to the intercarpellary membrane and the ability spread to a greater extent within the adjacent locule compared to the abilities of a control transformant. Conversely, eliminating the expression of pecA by targeted disruption caused a significant reduction in aggressiveness compared to that of a nondisrupted control transformant. These results provide direct evidence that P2c contributes to the invasion and spread of A. flavus during infection of cotton bolls. However, other factors not evaluated in this study also contribute to aggressiveness. PMID:9293005

Epidemiological profile of invasive bacterial diseases in children in Casablanca, Morocco: antimicrobial susceptibilities and serotype distribution.

PubMed

El Mdaghri, N; Jilali, N; Belabbes, H; Jouhadi, Z; Lahssoune, M; Zaid, S

2012-11-01

The aim of this prospective study in Morocco was to investigate the causes of invasive bacterial diseases in children in order to inform antibiotic therapy and vaccine choices. Of 238 children aged < or = 5 years admitted to the Children's Hospital of Casablanca for invasive diseases over a 12-month period, 185 were diagnosed with bacterial infection: 76 had chest-X-ray-confirmed pneumonia, 59 had meningitis and 50 had sepsis. Streptococcus pneumoniae was the most common pathogen identified (n = 24), followed by Neisseria meningitidis (n = 18, all group B) and Haemophilus influenzae (n = 11). The rate of penicillin non-susceptibility was 62.5% among Str. pneumoniae isolates and 11.1% among N. meningitidis and all isolates were ceftriaxone-susceptible. Of the 11 H. influenzae isolates, only 1 produced a beta-lactamase. The 5 predominant Str. pneumoniae serotypes were 19F, 14, 23F, 6B and 19A and the theoretical coverage of the 7, 10 and 13-valent pneumococcal conjugate vaccines was 60%, 78% and 91% respectively.

Five-year National Surveillance of Invasive Candidiasis: Species Distribution and Azole Susceptibility from the China Hospital Invasive Fungal Surveillance Net (CHIF-NET) Study.

PubMed

Xiao, Meng; Sun, Zi-Yong; Kang, Mei; Guo, Da-Wen; Liao, Kang; Chen, Sharon C-A; Kong, Fanrong; Fan, Xin; Cheng, Jing-Wei; Hou, Xin; Zhou, Meng-Lan; Li, Ying; Yu, Shu-Ying; Huang, Jing-Jing; Wang, He; Xu, Ying-Chun

2018-05-09

Data on the epidemiology of invasive candidiasis (IC) and antifungal susceptibility of Candida isolates in China are still limited. Here we report surveillance for IC from the China Hospital Invasive Fungal Surveillance Net (CHIF-NET) Study. Sixty-five tertiary hospitals collected 8,829 Candida isolates from August 1, 2009 to July 31, 2014. Matrix-assisted laser desorption/ionization -time of flight mass spectrometry supplemented by rDNA sequencing was used to define species, and fluconazole and voriconazole susceptibilities determined by the Clinical and Laboratory Standards Institute disk diffusion method. A total of 32 Candida species were identified. C. albicans was the most common species (44.9%) followed by C. parapsilosis complex (20.0%), C. tropicalis (17.2%) and C. glabrata complex (10.8%), with other species comprising <3%. However, in candidemia, the proportion of cases caused by C. albicans was only 32.3%. C. albicans and C. parapsilosis complex isolates were susceptible to fluconazole and voriconazole (<6% resistance), while fluconazole- and azole cross-resistant rates were high in C. tropicalis (13.3% and 12.9%), C. glabrata complex (18.7% and 14%) and uncommon Candida species (44.1% and 10.3%) isolates. Moreover, from year 1 to 5 of the study, there was a significant increase in resistant rates amongst C. glabrata complex isolates to fluconazole (12.2% to 24.0%), and amongst C. tropicalis isolates to both fluconazole (5.7% to 21.0%) and voriconazole (5.7% to 21.4%) (all P<0.01). Geographic variations in causative species and susceptibilities were noted. Our findings indicated that antifungal resistance have become noteworthy in China, and enhanced surveillance is warranted. Copyright © 2018 American Society for Microbiology.

Route of infection alters virulence of neonatal septicemia Escherichia coli clinical isolates

PubMed Central

Cole, Bryan K.; Scott, Edgar; Ilikj, Marko; Bard, David; Akins, Darrin R.; Dyer, David W.

2017-01-01

Escherichia coli is the leading cause of Gram-negative neonatal septicemia in the United States. Invasion and passage across the neonatal gut after ingestion of maternal E. coli strains produce bacteremia. In this study, we compared the virulence properties of the neonatal E. coli bacteremia clinical isolate SCB34 with the archetypal neonatal E. coli meningitis strain RS218. Whole-genome sequencing data was used to compare the protein coding sequences among these clinical isolates and 33 other representative E. coli strains. Oral inoculation of newborn animals with either strain produced septicemia, whereas intraperitoneal injection caused septicemia only in pups infected with RS218 but not in those injected with SCB34. In addition to being virulent only through the oral route, SCB34 demonstrated significantly greater invasion and transcytosis of polarized intestinal epithelial cells in vitro as compared to RS218. Protein coding sequences comparisons highlighted the presence of known virulence factors that are shared among several of these isolates, and revealed the existence of proteins exclusively encoded in SCB34, many of which remain uncharacterized. Our study demonstrates that oral acquisition is crucial for the virulence properties of the neonatal bacteremia clinical isolate SCB34. This characteristic, along with its enhanced ability to invade and transcytose intestinal epithelium are likely determined by the specific virulence factors that predominate in this strain. PMID:29236742

Reversal of gene dysregulation in cultured cytotrophoblasts reveals possible causes of preeclampsia

PubMed Central

Zhou, Yan; Gormley, Matthew J.; Hunkapiller, Nathan M.; Kapidzic, Mirhan; Stolyarov, Yana; Feng, Victoria; Nishida, Masakazu; Drake, Penelope M.; Bianco, Katherine; Wang, Fei; McMaster, Michael T.; Fisher, Susan J.

2013-01-01

During human pregnancy, a subset of placental cytotrophoblasts (CTBs) differentiates into cells that aggressively invade the uterus and its vasculature, anchoring the progeny and rerouting maternal blood to the placenta. In preeclampsia (PE), CTB invasion is limited, reducing placental perfusion and/or creating intermittent flow. This syndrome, affecting 4%–8% of pregnancies, entails maternal vascular alterations (e.g., high blood pressure, proteinuria, and edema) and, in some patients, fetal growth restriction. The only cure is removal of the faulty placenta, i.e., delivery. Previously, we showed that defective CTB differentiation contributes to the placental component of PE, but the causes were unknown. Here, we cultured CTBs isolated from PE and control placentas for 48 hours, enabling differentiation and invasion. In various severe forms of PE, transcriptomics revealed common aberrations in CTB gene expression immediately after isolation, including upregulation of SEMA3B, which resolved in culture. The addition of SEMA3B to normal CTBs inhibited invasion and recreated aspects of the PE phenotype. Additionally, SEMA3B downregulated VEGF signaling through the PI3K/AKT and GSK3 pathways, effects that were observed in PE CTBs. We propose that, in severe PE, the in vivo environment dysregulates CTB gene expression; the autocrine actions of the upregulated molecules (including SEMA3B) impair CTB differentiation, invasion and signaling; and patient-specific factors determine the signs. PMID:23934129

Serotype 5 pneumococci causing invasive pneumococcal disease outbreaks in Barcelona, Spain (1997 to 2011).

PubMed

Rolo, Dora; Fenoll, Asunción; Fontanals, Dionísia; Larrosa, Nieves; Giménez, Montserrat; Grau, Immaculada; Pallarés, Román; Liñares, Josefina; Ardanuy, Carmen

2013-11-01

In this study, we analyzed the clinical and molecular epidemiology of invasive serotype 5 (Ser5) pneumococcal isolates in four teaching hospitals in the Barcelona, Spain, area (from 1997 to 2011). Among 5,093 invasive pneumococcal isolates collected, 134 (2.6%) Ser5 isolates were detected. Although the overall incidence of Ser5-related invasive pneumococcal disease (IPD) was low (0.25 cases/100,000 inhabitants), three incidence peaks were detected: 0.63/100,000 in 1999, 1.15/100,000 in 2005, and 0.37/100,000 in 2009. The rates of Ser5 IPD were higher among young adults (18 to 64 years old) and older adults (>64 years old) in the first two peaks, whereas they were higher among children in 2009. The majority (88.8%) of the patients presented with pneumonia. Comorbid conditions were present in young adults (47.6%) and older adults (78.7%), the most common comorbid conditions being chronic obstructive pulmonary disease (20.6% and 38.3%, respectively) and cardiovascular diseases (11.1% and 38.3%, respectively). The mortality rates were higher among older adults (8.5%). All Ser5 pneumococci tested were fully susceptible to penicillin, cefotaxime, erythromycin, and ciprofloxacin. The resistance rates were 48.5% for co-trimoxazole, 6.7% for chloramphenicol, and 6% for tetracycline. Two major related sequence types (STs), ST1223 (n = 65) and ST289 (n = 61), were detected. The Colombia(5)-ST289 clone was responsible for all the cases in the Ser5 outbreak in 1999, whereas the ST1223 clone accounted for 73.8% and 61.5% of the isolates in 2005 and 2009, respectively. Ser5 pneumococci are a frequent cause of IPD outbreaks in the community and involve children and adults with or without comorbidities. The implementation of the new pneumococcal conjugated vaccines (PCV10 and PCV13) might prevent such outbreaks.

Molecular epidemiology of nga and NAD glycohydrolase/ADP-ribosyltransferase activity among Streptococcus pyogenes causing streptococcal toxic shock syndrome.

PubMed

Stevens, D L; Salmi, D B; McIndoo, E R; Bryant, A E

2000-10-01

Severe invasive group A streptococcal (GAS) infections emerged in the late 1980s, yet no single virulence factor has been common to all isolates from infected patients. A strong association was recently found between isolates of such cases (regardless of M type) and the production of NAD glycohydrolase (NADase). Of interest, all M-1 strains isolated after 1988 were positive for NADase, whereas virtually all M-1 GAS were previously negative for NADase. Genetic analysis demonstrated that GAS isolates were >96% identical in nga and >99% identical in their upstream regulatory sequences. Furthermore, because NADase-negative strains did not produce immunoreactive NADase, we concluded that additional regulatory element(s) control NADase production. NADase purified from GAS altered neutrophil-directed migration and chemiluminescence responses and had potent ADP-ribosyltransferase activity. In summary, the temporal relationship of NADase expression, alone or with other streptococcal virulence factors, may contribute to the pathogenesis of invasive GAS infections.

Molecular Typing and Epidemiology of Human Listeriosis Cases, Denmark, 2002-2012.

PubMed

Jensen, Anne Kvistholm; Björkman, Jonas T; Ethelberg, Steen; Kiil, Kristoffer; Kemp, Michael; Nielsen, Eva Møller

2016-04-01

Denmark has a high incidence of invasive listeriosis (0.9 cases/100,000 population in 2012). We analyzed patient data, clinical outcome, and trends in pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) of Listeria monocytogenes strains isolated in Denmark during 2002-2012. We performed 2-enzyme PFGE and serotyping on 559 isolates and MLST on 92 isolates and identified some correlation between molecular type and clinical outcome and patient characteristics. We found 178 different PFGE types, but isolates from 122 cases belonged to just 2 closely related PFGE types, clonal complex 8 and sequence type 8. These 2 types were the main cause of a peak in incidence of invasive listeriosis during 2005-2009, possibly representing an outbreak or the presence of a highly prevalent clone. However, current typing methods could not fully confirm these possibilities, highlighting the need for more refined discriminatory typing methods to identify outbreaks within frequently occurring L. monocytogenes PFGE types.

Molecular Typing and Epidemiology of Human Listeriosis Cases, Denmark, 2002–20121

PubMed Central

Björkman, Jonas T.; Ethelberg, Steen; Kiil, Kristoffer; Kemp, Michael; Nielsen, Eva Møller

2016-01-01

Denmark has a high incidence of invasive listeriosis (0.9 cases/100,000 population in 2012). We analyzed patient data, clinical outcome, and trends in pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) of Listeria monocytogenes strains isolated in Denmark during 2002–2012. We performed 2-enzyme PFGE and serotyping on 559 isolates and MLST on 92 isolates and identified some correlation between molecular type and clinical outcome and patient characteristics. We found 178 different PFGE types, but isolates from 122 cases belonged to just 2 closely related PFGE types, clonal complex 8 and sequence type 8. These 2 types were the main cause of a peak in incidence of invasive listeriosis during 2005–2009, possibly representing an outbreak or the presence of a highly prevalent clone. However, current typing methods could not fully confirm these possibilities, highlighting the need for more refined discriminatory typing methods to identify outbreaks within frequently occurring L. monocytogenes PFGE types. PMID:26982714

Increasing incidence of penicillin- and cefotaxime-resistant Streptococcus pneumoniae causing meningitis in India: Time for revision of treatment guidelines?

PubMed

Verghese, Valsan Philip; Veeraraghavan, Balaji; Jayaraman, Ranjith; Varghese, Rosemol; Neeravi, Ayyanraj; Jayaraman, Yuvaraj; Thomas, Kurien; Mehendale, Sanjay M

2017-01-01

Pneumococcal meningitis is a life-threatening infection, requiring prompt diagnosis and effective treatment. Penicillin resistance in pneumococcal infections is a concern. Here, we present the antibiotic susceptibility profile of pneumococcal meningeal isolates from January 2008 to August 2016 to elucidate treatment guidelines for pneumococcal meningitis. Invasive pneumococcal isolates from all age groups, were included in this study. Minimum inhibitory concentrations for the isolates were identified by agar dilution technique and VITEK System 2. Serotyping of isolates was done by co-agglutination technique. Out of 830 invasive pneumococcal isolates, 167 (20.1%) isolates were from meningeal infections. Cumulative penicillin resistance in pneumococcal meningitis was 43.7% and cefotaxime non-susceptibility was 14.9%. Penicillin resistance amongst meningeal isolates in those younger than 5 years, 5-16 years of age and those aged 16 years and older was 59.7%, 50% and 27.3%, respectively, with non-susceptibility to cefotaxime in the same age groups being 18%, 22.2% and 10.4%. Penicillin resistance amongst pneumococcal meningeal isolates increased from 9.5% in 2008 to 42.8% in 2016, whereas cefotaxime non-susceptibility increased from 4.7% in 2008 to 28.5% in 2016. Serotypes 14, 19F, 6B, 6A, 23F, 9V and 5 were the most common serotypes causing meningitis, with the first five accounting for over 75% of resistant isolates. The present study reports increasing penicillin resistance and cefotaxime non-susceptibility to pneumococcal meningitis in our setting. This highlights the need for empiric therapy with third-generation cephalosporins and vancomycin for all patients with meningitis while awaiting results of culture and susceptibility testing.

Molecular Characterization of Invasive Meningococcal Isolates from Countries in the African Meningitis Belt before Introduction of a Serogroup A Conjugate Vaccine

PubMed Central

Caugant, Dominique A.; Kristiansen, Paul A.; Wang, Xin; Mayer, Leonard W.; Taha, Muhamed-Kheir; Ouédraogo, Rasmata; Kandolo, Denis; Bougoudogo, Flabou; Sow, Samba; Bonte, Laurence

2012-01-01

Background The serogroup A conjugate meningococcal vaccine, MenAfriVac, was introduced in mass vaccination campaigns in December 2010 in Burkina Faso, Mali and Niger. In the coming years, vaccination will be extended to other African countries at risk of epidemics. To document the molecular characteristics of disease-causing meningococcal strains circulating in the meningitis belt of Africa before vaccine introduction, the World Health Organization Collaborating Centers on Meningococci in Europe and United States established a common strain collection of 773 isolates from cases of invasive meningococcal disease collected between 2004 and 2010 from 13 sub-Saharan countries. Methodology All isolates were characterized by multilocus sequence typing, and 487 (62%) were also analyzed for genetic variation in the surface antigens PorA and FetA. Antibiotic susceptibility was tested for part of the collection. Principal Findings Only 19 sequence types (STs) belonging to 6 clonal complexes were revealed. ST-5 clonal complex dominated with 578 (74.8%) isolates. All ST-5 complex isolates were remarkably homogeneous in their PorA (P1.20,9) and FetA (F3-1) and characterized the serogroup A strains which have been responsible for most epidemics during this time period. Sixty-eight (8.8%) of the 773 isolates belonged to the ST-11 clonal complex which was mainly represented by serogroup W135, while an additional 38 (4.9%) W135 isolates belonged to the ST-175 complex. Forty-eight (6.2%) serogroup X isolates from West Africa belonged to the ST-181 complex, while serogroup X cases in Kenya and Uganda were caused by an unrelated clone, ST-5403. Serogroup X, ST-181, emerged in Burkina Faso before vaccine introduction. Conclusions In the seven years preceding introduction of a new serogroup A conjugate vaccine, serogroup A of the ST-5 clonal complex was identified as the predominant disease-causing strain. PMID:23029368

Reduced susceptibility to penicillin among pneumococci causing invasive infection in children - Canada, 1991 to 1998

PubMed Central

Scheifele, David; Halperin, Scott; Pelletier, Louise; Talbot, James; Lovgren, Marguerite; Vaudry, Wendy; Jadavji, Taj; Law, Barbara; MacDonald, Noni; Gold, Ron; Wang, Elaine; Mills, Elaine; Lebel, Marc; Déry, Pierre; Morris, Rob

2001-01-01

OBJECTIVE: To determine, over time, the rate and serotypes of pneumococci with reduced penicillin susceptibility obtained from children with invasive infection. DESIGN: Active, hospital-based, multicentre surveillance spanning from 1991 to 1998. SETTING: Eleven Canadian tertiary care paediatric facilities located from coast to coast. POPULATION STUDIED: 1847 children with invasive pneumococcal infection whose isolates (from a normally sterile site) were available for serotyping and standardized testing for penicillin susceptibility at the National Centre for Streptococcus. MAIN RESULTS: The prevalence of reduced penicillin susceptibility increased from 2.5% of 197 cases in 1991 to 13.0% of 276 cases in 1998. In the latter year, 8.7% of isolates had intermediate level resistance, and 4.3% had high level resistance. Since they were first detected in 1992, strains with high level resistance have been encountered only sporadically at most centres, but by 1998, all centres but two had encountered examples. Of 40 isolates with high level resistance and 101 isolates with intermediate level resistance, serotypes matched those included in new seven-valent conjugate vaccines for children in 97.5% and 79.2% of cases, respectively. CONCLUSIONS: Pneumococci with reduced susceptibility to penicillin are increasing in frequency across Canada among children with invasive infection. The Immunization Monitoring Program, Active data indicate that new conjugate vaccines could help to curb infections due to pneumococci with reduced susceptibility to penicillin but are unlikely to control completely the problem of antibiotic resistance. PMID:18159346

Population-based study of invasive disease due to beta-hemolytic streptococci of groups other than A and B.

PubMed

Broyles, Laura N; Van Beneden, Chris; Beall, Bernard; Facklam, Richard; Shewmaker, P Lynn; Malpiedi, Paul; Daily, Pamala; Reingold, Arthur; Farley, Monica M

2009-03-15

Beta-hemolytic streptococci of groups other than A and B (NABS) are increasingly recognized as causes of clinically significant disease, but precise information about this heterogeneous group is lacking. We report the incidence of NABS infection and describe the epidemiologic and clinical characteristics. Active, population-based surveillance for invasive NABS was performed over a 2-year period in the 8-county metropolitan Atlanta, Georgia, area and the 3-county San Francisco Bay, California, area. Clinical records were reviewed, and available isolates were sent to the Centers for Disease Control and Prevention (Atlanta) for additional microbiologic characterization. Incidences were calculated using year-appropriate US Census Bureau data. A total of 489 cases of invasive NABS infection were identified (3.2 cases per 100,000 population). The median age of patients was 55 years; 64% of patients were males, and 87% had underlying diseases. The incidence was higher among black persons than white persons (4.0 vs. 2.5 cases per 100,000 population; P < .01) and increased with age among all races. Infections were community acquired in 416 cases (85%). Among the 450 patients (94%) with NABS infection who were hospitalized, 55 (12%) died. Of 266 isolates (54%) speciated at the Centers for Disease Control and Prevention, 212 (80%) were Streptococcus dysgalactiae subspecies equisimilis; 46 (17%) were members of the Streptococcus anginosus group. S. dysgalactiae subspecies equisimilis primarily presented as skin and soft-tissue infection in older patients, whereas individuals with invasive S. anginosus group infections were more likely to be younger patients with intra-abdominal infections. NABS comprise multiple distinct species that cause a significant number of community-acquired invasive infections. Clinical manifestations differ by species. Thus, speciation of invasive NABS may be warranted in clinical settings.

Evolution of antimicrobial resistance and serotype distribution of Streptococcus pneumoniae isolated from children with invasive and noninvasive pneumococcal diseases in Algeria from 2005 to 2012

PubMed Central

Ramdani-Bouguessa, N.; Ziane, H.; Bekhoucha, S.; Guechi, Z.; Azzam, A.; Touati, D.; Naim, M.; Azrou, S.; Hamidi, M.; Mertani, A.; Laraba, A.; Annane, T.; Kermani, S.; Tazir, M.

2015-01-01

Pneumococcal infections are a major cause of morbidity and mortality in developing countries. The introduction of pneumococcal conjugate vaccines (PCVs) has dramatically reduced the incidence of pneumococcal diseases. PCVs are not currently being used in Algeria. We conducted a prospective study from 2005 to 2012 in Algeria to determine antimicrobial drug resistance and serotype distribution of Streptococcus pneumoniae from children with pneumococcal disease. Among 270 isolated strains from children, 97 (36%) were invasive disease; of these, 48% were not susceptible to penicillin and 53% not susceptible to erythromycin. A high rate of antimicrobial nonsusceptibility was observed in strains isolated from children with meningitis. The serotype distribution from pneumococci isolated from children with invasive infections was (by order of prevalence): 14, 1, 19F, 19A, 6B, 5, 3, 6A and 23F. Multidrug resistance was observed in serotypes 14, 19F, 19A and 6B. The vaccine coverage of serotypes isolated from children aged <5 years was 55.3% for PCV7, 71.1% for PCV10 and 86.8% for PCV13. Our results highlight the burden of pneumococcal disease in Algeria and the increasing S. pneumoniae antibiotic resistance. The current pneumococcal vaccines cover a high percentage of the circulating strains. Therefore, vaccination would reduce the incidence of pneumococcal disease in Algeria. PMID:26106481

Species-Level Identification of Actinomyces Isolates Causing Invasive Infections: Multiyear Comparison of Vitek MS (Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry) to Partial Sequencing of the 16S rRNA Gene.

PubMed

Lynch, T; Gregson, D; Church, D L

2016-03-01

Actinomyces species are uncommon but important causes of invasive infections. The ability of our regional clinical microbiology laboratory to report species-level identification of Actinomyces relied on molecular identification by partial sequencing of the 16S ribosomal gene prior to the implementation of the Vitek MS (matrix-assisted laser desorption ionization-time of flight mass spectrometry [MALDI-TOF MS]) system. We compared the use of the Vitek MS to that of 16S rRNA gene sequencing for reliable species-level identification of invasive infections caused by Actinomyces spp. because limited data had been published for this important genera. A total of 115 cases of Actinomyces spp., either alone or as part of a polymicrobial infection, were diagnosed between 2011 and 2014. Actinomyces spp. were considered the principal pathogen in bloodstream infections (n = 17, 15%), in skin and soft tissue abscesses (n = 25, 22%), and in pulmonary (n = 26, 23%), bone (n = 27, 23%), intraabdominal (n = 16, 14%), and central nervous system (n = 4, 3%) infections. Compared to sequencing and identification from the SmartGene Integrated Database Network System (IDNS), Vitek MS identified 47/115 (41%) isolates to the correct species and 10 (9%) isolates to the correct genus. However, the Vitek MS was unable to provide identification for 43 (37%) isolates while 15 (13%) had discordant results. Phylogenetic analyses of the 16S rRNA sequences demonstrate high diversity in recovered Actinomyces spp. and provide additional information to compare/confirm discordant identifications between MALDI-TOF and 16S rRNA gene sequences. This study highlights the diversity of clinically relevant Actinomyces spp. and provides an important typing comparison. Based on our analysis, 16S rRNA gene sequencing should be used to rapidly identify Actinomyces spp. until MALDI-TOF databases are optimized. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Species-Level Identification of Actinomyces Isolates Causing Invasive Infections: Multiyear Comparison of Vitek MS (Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry) to Partial Sequencing of the 16S rRNA Gene

PubMed Central

Gregson, D.; Church, D. L.

2016-01-01

Actinomyces species are uncommon but important causes of invasive infections. The ability of our regional clinical microbiology laboratory to report species-level identification of Actinomyces relied on molecular identification by partial sequencing of the 16S ribosomal gene prior to the implementation of the Vitek MS (matrix-assisted laser desorption ionization–time of flight mass spectrometry [MALDI-TOF MS]) system. We compared the use of the Vitek MS to that of 16S rRNA gene sequencing for reliable species-level identification of invasive infections caused by Actinomyces spp. because limited data had been published for this important genera. A total of 115 cases of Actinomyces spp., either alone or as part of a polymicrobial infection, were diagnosed between 2011 and 2014. Actinomyces spp. were considered the principal pathogen in bloodstream infections (n = 17, 15%), in skin and soft tissue abscesses (n = 25, 22%), and in pulmonary (n = 26, 23%), bone (n = 27, 23%), intraabdominal (n = 16, 14%), and central nervous system (n = 4, 3%) infections. Compared to sequencing and identification from the SmartGene Integrated Database Network System (IDNS), Vitek MS identified 47/115 (41%) isolates to the correct species and 10 (9%) isolates to the correct genus. However, the Vitek MS was unable to provide identification for 43 (37%) isolates while 15 (13%) had discordant results. Phylogenetic analyses of the 16S rRNA sequences demonstrate high diversity in recovered Actinomyces spp. and provide additional information to compare/confirm discordant identifications between MALDI-TOF and 16S rRNA gene sequences. This study highlights the diversity of clinically relevant Actinomyces spp. and provides an important typing comparison. Based on our analysis, 16S rRNA gene sequencing should be used to rapidly identify Actinomyces spp. until MALDI-TOF databases are optimized. PMID:26739153

First two cases of severe multifocal infections caused by Klebsiella pneumoniae in Switzerland: characterization of an atypical non-K1/K2-serotype strain causing liver abscess and endocarditis.

PubMed

Babouee Flury, Baharak; Donà, Valentina; Buetti, Niccolò; Furrer, Hansjakob; Endimiani, Andrea

2017-09-01

We describe the first two multifocal invasive infections due to Klebsiella pneumoniae recently observed in Switzerland. Phenotypic (MIC assays and string test) and molecular analyses (PCR/Sequencing for bla, virulence factor genes and whole genome sequencing for one strain) were performed to characterize the causative K. pneumoniae isolates. Both K. pneumoniae isolates (Kp1 and Kp2) were pan-susceptible to antibiotics and produced narrow-spectrum SHV β-lactamases. However, only Kp1 was string test positive. Kp1 was of ST380 and caused liver abscess as well as pneumonia and orbital phlegmon in an Eritrean patient. It belonged to the hypervirulent capsular serotype K2 and harboured the classic virulence-associated rmpA and aerobactin genes, fulfilling both the clinical and microbiological definitions for an invasive K. pneumoniae syndrome. Kp2 was of ST1043 and caused both liver abscess and endocarditis in a Swiss patient. Moreover, it did not possess the classic virulence-associated genes. Whole genome sequencing identified less well-known virulence factors in Kp2 that might have contributed to its virulence. Among these there were genes important for intestinal colonization and/or invasion, such as genes involved in adhesion (e.g., fimABCD and mrkABCD), regulation of capsule polysaccharide biosynthesis (e.g., evgS-evgA), as well as iron uptake (iroN), energy conversion, and metabolism. This report confirms the continuous dissemination of hypervirulent K. pneumoniae strains among patients of non-Asian descent in Europe. Moreover, it highlights the genetic background of an atypical hypervirulent K. pneumoniae causing a severe invasive infection despite not possessing the classical virulence characteristics of hypermucoviscous strains. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

[Invasive fungal infections in immunocompromised patients with focus on aspergillosis and its causative agents].

PubMed

Paloušová, Dita; Lengerová, Martina; Volfová, Pavlína; Bejdák, Petr; Kocmanová, Iva; Mayer, Jiří; Ráčil, Zdeněk

2012-08-01

Invasive fungal diseases (IFD) are a life-threatening infectious complications in immunocompromised patients and are associated with high rate of morbidity and mortality. The most common invasive mycosis in patients who underwent an allogeneic hematopoietic stem cell transplantation is invasive aspergilosis (IA), most frequently caused by the clinically dominant species Aspergillus fumigatus and, rarely, also by Aspergillus flavus, Aspergillus terreus and Aspergillus niger. In recent years, other related Aspergillus species were also reported to cause IFD, phenotypically similar to A. fumigatus and moreover, frequently exhibiting resistance towards various antifungals. For example, it is Aspergillus lentulus, Aspergillus viridinutans, Neosartoya fischeri, etc. Classical microbiological methods such as direct microscopy or culture are usually used for the identification of Aspergillus species. The application of PCR-based molecular techniques and monitoring of secondary metabolites production enable detection and identification of species, which are not distinguishable solely by their morphology. PCR methods are also useful for molecular strain typing of aspergilli and can reveal the genetic diversity of isolates.

Invasive disease caused by Haemophilus influenzae in Sweden 1997-2009; evidence of increasing incidence and clinical burden of non-type b strains.

PubMed

Resman, F; Ristovski, M; Ahl, J; Forsgren, A; Gilsdorf, J R; Jasir, A; Kaijser, B; Kronvall, G; Riesbeck, K

2011-11-01

Introduction of a conjugated vaccine against encapsulated Haemophilus influenzae type b (Hib) has led to a dramatic reduction of invasive Hib disease. However, an increasing incidence of invasive disease by H. influenzae non-type b has recently been reported. Non-type b strains have been suggested to be opportunists in an invasive context, but information on clinical consequences and related medical conditions is scarce. In this retrospective study, all H. influenzae isolates (n = 410) from blood and cerebrospinal fluid in three metropolitan Swedish regions between 1997 and 2009 from a population of approximately 3 million individuals were identified. All available isolates were serotyped by PCR (n = 250). We observed a statistically significant increase in the incidence of invasive H. influenzae disease, ascribed to non-typeable H. influenzae (NTHi) and encapsulated strains type f (Hif) in mainly individuals >60 years of age. The medical reports from a subset of 136 cases of invasive Haemophilus disease revealed that 48% of invasive NTHi cases and 59% of invasive Hif cases, respectively, met the criteria of severe sepsis or septic shock according to the ACCP/SCCM classification of sepsis grading. One-fifth of invasive NTHi cases and more than one-third of invasive Hif cases were admitted to intensive care units. Only 37% of patients with invasive non-type b disease had evidence of immunocompromise, of which conditions related to impaired humoral immunity was the most common. The clinical burden of invasive non-type b H. influenzae disease, measured as days of hospitalization/100 000 individuals at risk and year, increased significantly throughout the study period. © 2011 The Authors. Clinical Microbiology and Infection © 2011 European Society of Clinical Microbiology and Infectious Diseases.

PCR Followed by Electrospray Ionization Mass Spectrometry for Broad-Range Identification of Fungal Pathogens

PubMed Central

Massire, Christian; Buelow, Daelynn R.; Zhang, Sean X.; Lovari, Robert; Matthews, Heather E.; Toleno, Donna M.; Ranken, Raymond R.; Hall, Thomas A.; Metzgar, David; Sampath, Rangarajan; Blyn, Lawrence B.; Ecker, David J.; Gu, Zhengming; Walsh, Thomas J.

2013-01-01

Invasive fungal infections are a significant cause of morbidity and mortality among immunocompromised patients. Early and accurate identification of these pathogens is central to direct therapy and to improve overall outcome. PCR coupled with electrospray ionization mass spectrometry (PCR/ESI-MS) was evaluated as a novel means for identification of fungal pathogens. Using a database grounded by 60 ATCC reference strains, a total of 394 clinical fungal isolates (264 molds and 130 yeasts) were analyzed by PCR/ESI-MS; results were compared to phenotypic identification, and discrepant results were sequence confirmed. PCR/ESI-MS identified 81.4% of molds to either the genus or species level, with concordance rates of 89.7% and 87.4%, respectively, to phenotypic identification. Likewise, PCR/ESI-MS was able to identify 98.4% of yeasts to either the genus or species level, agreeing with 100% of phenotypic results at both the genus and species level. PCR/ESI-MS performed best with Aspergillus and Candida isolates, generating species-level identification in 94.4% and 99.2% of isolates, respectively. PCR/ESI-MS is a promising new technology for broad-range detection and identification of medically important fungal pathogens that cause invasive mycoses. PMID:23303501

[Nosocomial infection due to Trichosporon asahii in a critical burned patient].

PubMed

Tamayo Lomas, Luis; Domínguez-Gil González, Marta; Martín Luengo, Ana Isabel; Eiros Bouza, José María; Piqueras Pérez, José María

2015-01-01

Invasive fungal infection is an important cause of morbimortality in patients with severe burns. The advances in burn care therapy have considerably extended the survival of seriously burned patients, exposing them to infectious complications, notably fungal infections, with increased recognition of invasive infections caused by Candida species. However, some opportunistic fungi, like Trichosporon asahii, have emerged as important causes of nosocomial infection. A case of nosocomial infection due to T. asahii in a severely ill burned patient successfully treated with voriconazole is presented. The management of invasive fungal infections in burned patients, from diagnosis to selection of the therapeutic protocol, is often a challenge. Early diagnosis and treatment are associated with a better prognosis. In this case report, current treatment options are discussed, and a review of previously published cases is presented. Due to the difficulty in the diagnosis of invasive mycoses and their high associated mortality rates, it is advisable to keep a high degree of clinical suspicion of trichosporonosis in susceptible patients, including burned patients. The isolation of T. asahii in clinical specimens of this type of host must raise clinical alert, since it may precede an invasive infection. Copyright © 2014 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Haemophilus influenzae Type b Carriage and Novel Bacterial Population Structure among Children in Urban Kathmandu, Nepal▿

PubMed Central

Williams, E. J.; Lewis, J.; John, T.; Hoe, J. C.; Yu, L.; Dongol, S.; Kelly, D. F.; Griffiths, D. T.; Shah, A.; Limbu, B.; Pradhan, R.; Mawas, F.; Shrestha, S.; Thorson, S.; Werno, A. M.; Murdoch, D. R.; Adhikari, N.; Pollard, A. J.

2011-01-01

Haemophilus influenzae type b (Hib) is a major cause of invasive bacterial infection in children that can be prevented by a vaccine, but there is still uncertainty about its relative importance in Asia. This study investigated the age-specific prevalence of Hib carriage and its molecular epidemiology in carriage and disease in Nepal. Oropharyngeal swabs were collected from children in Kathmandu, Nepal, from 3 different settings: a hospital outpatient department (OPD), schools, and children's homes. Hib was isolated using Hib antiserum agar plates, and serotyping was performed with latex agglutination. Hib isolates from children with invasive disease were obtained during active microbiological surveillance at Patan Hospital, Kathmandu, Nepal. Genotyping of disease and carriage isolates was undertaken using multilocus sequence typing (MLST). Swabs were taken from 2,195 children, including 1,311 children at an OPD, 647 children attending schools, and 237 children in homes. Overall, Hib was identified in 5.0% (110/2,195; 95% confidence interval [95% CI], 3.9% to 6.4%). MLST was performed on 108 Hib isolates from children carrying Hib isolates and 15 isolates from children with invasive disease. Thirty-one sequence types (STs) were identified, and 20 of these were novel STs. The most common ST isolates were sequence type 6 (ST6) and the novel ST722. There was marked heterogeneity among the STs from children with disease and children carrying Hib. STs identified from invasive infections were those commonly identified in carriage. This study provides evidence of Hib carriage among children in urban Nepal with genetically diverse strains prior to introduction of universal vaccination. The Hib carriage rate in Nepal was similar to the rates observed in other populations with documented high disease rates prior to vaccination, supporting implementation of Hib vaccine in Nepal in 2009. PMID:21270225

Host-pathogen interactions in bovine mammary epithelial cells and HeLa cells by Staphylococcus aureus isolated from subclinical bovine mastitis.

PubMed

Castilho, Ivana G; Dantas, Stéfani Thais Alves; Langoni, Hélio; Araújo, João P; Fernandes, Ary; Alvarenga, Fernanda C L; Maia, Leandro; Cagnini, Didier Q; Rall, Vera L M

2017-08-01

Staphylococcus aureus is a common pathogen that causes subclinical bovine mastitis due to several virulence factors. In this study, we analyzed S. aureus isolates collected from the milk of cows with subclinical mastitis that had 8 possible combinations of bap, icaA, and icaD genes, to determine their capacity to produce biofilm on biotic (bovine primary mammary epithelial cells and HeLa cells) and abiotic (polystyrene microplates) surfaces, and their ability to adhere to and invade these cells. We also characterized isolates for microbial surface components recognizing adhesive matrix molecules (MSCRAMM) and agr genes, and for their susceptibility to cefquinome sulfate in the presence of biofilm. All isolates adhered to and invaded both cell types, but invasion indexes were higher in bovine primary mammary epithelial cells. Using tryptic soy broth + 1% glucose on abiotic surfaces, 5 out of 8 isolates were biofilm producers, but only the bap + icaA + icaD + isolate was positive in Dulbecco's Modified Eagle's medium. The production of biofilm on biotic surfaces occurred only with this isolate and only on HeLa cells, because the invasion index for bovine primary mammary epithelial cells was too high, making it impossible to use these cells in this assay. Of the 5 biofilm producers in tryptic soy broth + 1% glucose, 4 presented with the bap/fnbA/clfA/clfB/eno/fib/ebpS combination, and all were protected from cefquinome sulfate. We found no predominance of any agr group. The high invasive potential of S. aureus made it impossible to observe biofilm in bovine primary mammary epithelial cells, and we concluded that cells with lower invasion rates, such as HeLa cells, were more appropriate for this assay. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Identification and susceptibility of clinical isolates of Candida spp. to killer toxins.

PubMed

Robledo-Leal, E; Rivera-Morales, L G; Sangorrín, M P; González, G M; Ramos-Alfano, G; Adame-Rodriguez, J M; Alcocer-Gonzalez, J M; Arechiga-Carvajal, E T; Rodriguez-Padilla, C

2018-02-01

Although invasive infections and mortality caused by Candida species are increasing among compromised patients, resistance to common antifungal agents is also an increasing problem. We analyzed 60 yeasts isolated from patients with invasive candidiasis using a PCR/RFLP strategy based on the internal transcribed spacer (ITS2) region to identify different Candida pathogenic species. PCR analysis was performed from genomic DNA with a primer pair of the ITS2-5.8S rDNA region. PCR-positive samples were characterized by RFLP. Restriction resulted in 23 isolates identified as C. albicans using AlwI, 24 isolates as C. parapsilosis using RsaI, and 13 as C. tropicalis using XmaI. Then, a group of all isolates were evaluated for their susceptibility to a panel of previously described killer yeasts, resulting in 75% being susceptible to at least one killer yeast while the remaining were not inhibited by any strain. C. albicans was the most susceptible group while C. tropicalis had the fewest inhibitions. No species-specific pattern of inhibition was obtained with this panel of killer yeasts. Metschnikowia pulcherrima, Pichia kluyveri and Wickerhamomyces anomalus were the strains that inhibited the most isolates of Candida spp.

The Dark Side Is Not Fastidious – Dark Septate Endophytic Fungi of Native and Invasive Plants of Semiarid Sandy Areas

PubMed Central

Knapp, Dániel G.; Pintye, Alexandra; Kovács, Gábor M.

2012-01-01

Dark septate endophytic (DSE) fungi represent a frequent root-colonizing fungal group common in environments with strong abiotic stress, such as (semi)arid ecosystems. This work aimed to study the DSE fungi colonizing the plants of semiarid sandy grasslands with wood steppe patches on the Great Hungarian Plain. As we may assume that fungi colonizing both invasive and native species are generalists, root associated fungi (RAF) were isolated from eight native and three invasive plant species. The nrDNA sequences of the isolates were used for identification. To confirm that the fungi were endophytes an artificial inoculation system was used to test the isolates: we considered a fungus as DSE if it colonized the roots without causing a negative effect on the plant and formed microsclerotia in the roots. According to the analyses of the ITS sequence of nrDNA the 296 isolates clustered into 41 groups. We found that 14 of these 41 groups were DSE, representing approximately 60% of the isolates. The main DSE groups were generalist and showed no specificity to area or season and colonized both native and invasive species, demonstrating that exotic plants are capable of using the root endophytic fungi of the invaded areas. The DSE community of the region shows high similarity to those found in arid grasslands of North America. Taking into account a previous hypothesis about the common root colonizers of those grasslands and our results reported here, we hypothesize that plants of (semi)arid grasslands share common dominant members of the DSE fungal community on a global scale. PMID:22393417

Streptococcus pneumoniae serotype prevalence and antibiotic resistance among young children with invasive pneumococcal disease: experience from a tertiary care center in South India.

PubMed

Nagaraj, Savitha; Kalal, Bhuvanesh Sukhlal; Manoharan, Anand; Shet, Anita

2017-06-01

We performed a study to describe the clinical profile, antimicrobial susceptibility and prevalent serotypes of pneumococcal isolates from children with suspected invasive pneumococcal disease (IPD) admitted to a tertiary care hospital in South India. Hospitalized children, ≤ 5 years with fever (>38 °C); increased respiratory rate or neurological symptoms were recruited, (as part of the Alliance for Surveillance of Invasive Pneumococci - ASIP - project) from January 2011 to March 2013. Identification of pneumococcal isolates from blood or cerebrospinal fluid samples was done by routine culture methods. Isolates were analyzed for antimicrobial susceptibility, and confirmed by serotyping (using Quellung's test) and multiplex PCR. Out of the 171 samples received in the lab, 17 grew pneumococci identified by standard methods. Fourteen of them were confirmed by multiplex PCR. Maximum recruitment was observed during the months of January and February (36.4%, 28.6%). The average age of affected subjects was 21 months. The common clinical presentation was pneumonia (42.8%). Two isolates belonging to the 19F and 19B serotypes were resistant to penicillin (on Etest). The observed serotype distribution was 6B and 19F (2 each), and 1, 2, 6A, 9V, 10A, 14, 15A, 19B, 21, 35F (1 each). The overall fatality rate was 14.3% (n=2); the S. pneumoniae isolates from these two patients belonged to the non-vaccine serotype 19B and vaccine serotype 19F and demonstrated in vitro resistance to penicillin and erythromycin. Our study demonstrates the presence of invasive pneumococcal disease among under-5-year-old children in India caused by serotypes that are in large part covered by available pneumococcal vaccines.

Streptococcus pneumoniae serotype prevalence and antibiotic resistance among young children with invasive pneumococcal disease: experience from a tertiary care center in South India

PubMed Central

Nagaraj, Savitha; Kalal, Bhuvanesh Sukhlal; Manoharan, Anand; Shet, Anita

2017-01-01

Introduction We performed a study to describe the clinical profile, antimicrobial susceptibility and prevalent serotypes of pneumococcal isolates from children with suspected invasive pneumococcal disease (IPD) admitted to a tertiary care hospital in South India. Methods Hospitalized children, ≤ 5 years with fever (>38 °C); increased respiratory rate or neurological symptoms were recruited, (as part of the Alliance for Surveillance of Invasive Pneumococci – ASIP – project) from January 2011 to March 2013. Identification of pneumococcal isolates from blood or cerebrospinal fluid samples was done by routine culture methods. Isolates were analyzed for antimicrobial susceptibility, and confirmed by serotyping (using Quellung’s test) and multiplex PCR. Results Out of the 171 samples received in the lab, 17 grew pneumococci identified by standard methods. Fourteen of them were confirmed by multiplex PCR. Maximum recruitment was observed during the months of January and February (36.4%, 28.6%). The average age of affected subjects was 21 months. The common clinical presentation was pneumonia (42.8%). Two isolates belonging to the 19F and 19B serotypes were resistant to penicillin (on Etest). The observed serotype distribution was 6B and 19F (2 each), and 1, 2, 6A, 9V, 10A, 14, 15A, 19B, 21, 35F (1 each). The overall fatality rate was 14.3% (n=2); the S. pneumoniae isolates from these two patients belonged to the non-vaccine serotype 19B and vaccine serotype 19F and demonstrated in vitro resistance to penicillin and erythromycin. Conclusion Our study demonstrates the presence of invasive pneumococcal disease among under-5-year-old children in India caused by serotypes that are in large part covered by available pneumococcal vaccines. PMID:28626738

Identification and characterization of multidrug-resistant Salmonella enterica serotype Albert isolates in the United States

USDA-ARS?s Scientific Manuscript database

Salmonella enterica is one of the most common causes of bacterial foodborne illness in the United States. Although most Salmonella infections are self-limiting, antimicrobial treatment is critical for invasive salmonellosis. Primary antimicrobial treatment options include fluoroquinolones or extende...

Phytotoxic potential of Onopordum acanthium L. (Asteraceae).

PubMed

Watanabe, Yusuke; Novaes, Paula; Varela, Rosa M; Molinillo, José M G; Kato-Noguchi, Hisashi; Macías, Francisco A

2014-08-01

Onopordum acanthium L. (Asteraceae) is a plant native to southern Europe and southwestern Asia, but it is invasive in disturbed areas and agricultural fields around the world, causing many agronomic problems by interfering with crops or preventing animals from grazing on pastures. Allelopathy could be one of the reasons that this plant has spread over different continents. The aim of the present study was to bioprospect O. acanthium leaf extracts through the isolation and purification of allelopathic secondary metabolites with phytotoxicity to explain their invasive behavior. Phytotoxic activity was tested using etiolated wheat coleoptiles. The most active extract was selected to perform a bioassay-guided isolation of two flavonoids, pectolarigenin (1) and scutellarein 4'-methyl ether (2), and two sesquiterpene lactones, elemanolide 11(13)-dehydromelitensin β-hydroxyisobutyrate (3) and acanthiolide (4). All compounds were isolated for the first time from O. acanthium, and acanthiolide (4) is described for the first time. Compound 3 strongly inhibited the growth of wheat coleoptiles and 1 showed an intermediate effect. The results indicate that these compounds could contribute to the invasion of O. acanthium in ecological systems and agricultural fields. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.

Presentation of life-threatening invasive nontyphoidal Salmonella disease in Malawian children: A prospective observational study.

PubMed

MacLennan, Calman A; Msefula, Chisomo L; Gondwe, Esther N; Gilchrist, James J; Pensulo, Paul; Mandala, Wilson L; Mwimaniwa, Grace; Banda, Meraby; Kenny, Julia; Wilson, Lorna K; Phiri, Amos; MacLennan, Jenny M; Molyneux, Elizabeth M; Molyneux, Malcolm E; Graham, Stephen M

2017-12-01

Nontyphoidal Salmonellae commonly cause invasive disease in African children that is often fatal. The clinical diagnosis of these infections is hampered by the absence of a clear clinical syndrome. Drug resistance means that empirical antibiotic therapy is often ineffective and currently no vaccine is available. The study objective was to identify risk factors for mortality among children presenting to hospital with invasive Salmonella disease in Africa. We conducted a prospective study enrolling consecutive children with microbiologically-confirmed invasive Salmonella disease admitted to Queen Elizabeth Central Hospital, Blantyre, in 2006. Data on clinical presentation, co-morbidities and outcome were used to identify children at risk of inpatient mortality through logistic-regression modeling. Over one calendar year, 263 consecutive children presented with invasive Salmonella disease. Median age was 16 months (range 0-15 years) and 52/256 children (20%; 95%CI 15-25%) died. Nontyphoidal serovars caused 248/263 (94%) of cases. 211/259 (81%) of isolates were multi-drug resistant. 251/263 children presented with bacteremia, 6 with meningitis and 6 with both. Respiratory symptoms were present in 184/240 (77%; 95%CI 71-82%), 123/240 (51%; 95%CI 45-58%) had gastrointestinal symptoms and 101/240 (42%; 95%CI 36-49%) had an overlapping clinical syndrome. Presentation at <7 months (OR 10.0; 95%CI 2.8-35.1), dyspnea (OR 4.2; 95%CI 1.5-12.0) and HIV infection (OR 3.3; 95%CI 1.1-10.2) were independent risk factors for inpatient mortality. Invasive Salmonella disease in Malawi is characterized by high mortality and prevalence of multi-drug resistant isolates, along with non-specific presentation. Young infants, children with dyspnea and HIV-infected children bear a disproportionate burden of the Salmonella-associated mortality in Malawi. Strategies to improve prevention, diagnosis and management of invasive Salmonella disease should be targeted at these children.

Presentation of life-threatening invasive nontyphoidal Salmonella disease in Malawian children: A prospective observational study

PubMed Central

Msefula, Chisomo L.; Gondwe, Esther N.; Gilchrist, James J.; Pensulo, Paul; Mandala, Wilson L.; Mwimaniwa, Grace; Banda, Meraby; Kenny, Julia; Wilson, Lorna K.; Phiri, Amos; MacLennan, Jenny M.; Molyneux, Elizabeth M.; Molyneux, Malcolm E.; Graham, Stephen M.

2017-01-01

Nontyphoidal Salmonellae commonly cause invasive disease in African children that is often fatal. The clinical diagnosis of these infections is hampered by the absence of a clear clinical syndrome. Drug resistance means that empirical antibiotic therapy is often ineffective and currently no vaccine is available. The study objective was to identify risk factors for mortality among children presenting to hospital with invasive Salmonella disease in Africa. We conducted a prospective study enrolling consecutive children with microbiologically-confirmed invasive Salmonella disease admitted to Queen Elizabeth Central Hospital, Blantyre, in 2006. Data on clinical presentation, co-morbidities and outcome were used to identify children at risk of inpatient mortality through logistic-regression modeling. Over one calendar year, 263 consecutive children presented with invasive Salmonella disease. Median age was 16 months (range 0–15 years) and 52/256 children (20%; 95%CI 15–25%) died. Nontyphoidal serovars caused 248/263 (94%) of cases. 211/259 (81%) of isolates were multi-drug resistant. 251/263 children presented with bacteremia, 6 with meningitis and 6 with both. Respiratory symptoms were present in 184/240 (77%; 95%CI 71–82%), 123/240 (51%; 95%CI 45–58%) had gastrointestinal symptoms and 101/240 (42%; 95%CI 36–49%) had an overlapping clinical syndrome. Presentation at <7 months (OR 10.0; 95%CI 2.8–35.1), dyspnea (OR 4.2; 95%CI 1.5–12.0) and HIV infection (OR 3.3; 95%CI 1.1–10.2) were independent risk factors for inpatient mortality. Invasive Salmonella disease in Malawi is characterized by high mortality and prevalence of multi-drug resistant isolates, along with non-specific presentation. Young infants, children with dyspnea and HIV-infected children bear a disproportionate burden of the Salmonella-associated mortality in Malawi. Strategies to improve prevention, diagnosis and management of invasive Salmonella disease should be targeted at these children. PMID:29216183

[Surveillance of Haemophilus influenzae serotypes in Argentina from 2005 to 2010 during the Haemophilus influenzae type b conjugate vaccine era].

PubMed

Efron, Adriana M; Moscoloni, María A; Reijtman, Vanesa R; Regueira, Mabel

2013-01-01

The introduction of the Haemophilus influenzae type b vaccine in the immunization programs of many countries has greatly reduced this invasive disease and the carriage caused by this serotype, also increasing other capsular types and non-capsular isolations. There were 313 isolations of H. influenzae under study, which were recovered from a sterile site coming from pediatric and adult patients carrying the invasive disease. Patients were treated at 90 different hospitals belonging to the Red Nacional de Laboratorios para Meningitis e Infecciones Respiratorias Agudas Bacterianas (National Lab Network for Meningitis and Acute Bacterial Respiratory Infections) from 2005 to 2010 for the following disorders: pneumonia, 40.3% (n=126), meningitis, 30.0% (n=94) and bacteremia, 26.5% (n=83). In pediatric patients (n=279), the highest frequency of isolations corresponded to children under the age of 2 years, 74.5% (n=208). Regarding type distribution, 61.3% corresponded to non-capsular H. influenzae (n=192), 20.1% to type b (n=63), 11.2% to type a (n=35), 4.8% to type f, and 2.6% to other types. Capsular H. influenzae was predominant in meningitis whereas non-capsular H. influenzae in pneumonia and bacteremia. The biotype was determined in 306 isolations. The totality (100%) of type a (n=35) was biotype II whereas 66.7% of type b (n=63) was biotype I. Slide agglutination and PCR tests were used in 220 isolations. There was a match of 0.982 (IC: 0.92-1.00) between them. During the last year, there was a great increase in type b, showing the importance of clinical and laboratory-based surveillance of the invasive disease caused by H. influenzae. Copyright © 2013 Asociación Argentina de Microbiología. Publicado por Elsevier España. All rights reserved.

Analysis of invasive pneumonia-causing strains of Streptococcus pneumoniae: serotypes and antimicrobial susceptibility.

PubMed

Yoshioka, Cristina R M; Martinez, Marina B; Brandileone, Maria C C; Ragazzi, Selma B; Guerra, Maria L L S; Santos, Silvia R; Shieh, Huei H; Gilio, Alfredo E

2011-01-01

To identify the most common pneumococcal serotypes in children hospitalized with invasive pneumonia, correlate isolated serotypes with those included in conjugate vaccines, and ascertain the sensitivity of the isolated pneumococcal strains to penicillin and other antibiotics. From January 2003 to October 2008, a retrospective study of hospitalized children with a diagnosis of Streptococcus pneumoniae pneumonia was conducted at the university hospital of Universidade de São Paulo. Criteria for inclusion were: age greater than 29 days and less than 15 years, radiological and clinical diagnosis of pneumonia, and isolation of Streptococcus pneumoniae in blood cultures and/or pleural effusion. The study included 107 children. The most common serotypes were 14 (36.5%), 1 (16%), 5 (14.6%), 6B (6.3%) and 3 (4.2%). The proportion of identified serotypes contained in the heptavalent, 10-valent and 13-valent conjugate vaccines was 53.1, 86.5, and 96.9%, respectively. Pneumococcal strains were sensitive to penicillin (minimum inhibitory concentration, MIC ≤ 2 µg/mL) in 100 cases (93.5%) and displayed intermediate resistance (MIC = 4 µg/mL) in 7 cases (6.5%). No strains were penicillin-resistant (MIC ≥ 8 µg/mL) according to the Clinical and Laboratory Standards Institute 2008 standards. Tested isolates were highly sensitive to vancomycin, rifampicin, ceftriaxone, clindamycin, erythromycin, and chloramphenicol. Our results confirm a significant potential impact of conjugate vaccines, mainly 10-valent and 13-valent, on invasive pneumonia. Furthermore, susceptibility testing results show that penicillin is still the treatment of choice for invasive pneumonia in our setting.

Molecular epidemiology and virulence assessment of Aspergillus fumigatus isolates from white stork chicks and their environment.

PubMed

Olias, Philipp; Gruber, Achim D; Hafez, Hafez M; Lierz, Michael; Slesiona, Silvia; Brock, Matthias; Jacobsen, Ilse D

2011-03-24

Aspergillus fumigatus is a common pathogen in poultry and captive wild birds and an emerging opportunistic fungal pathogen in immunocompromised humans. Although invasive aspergillosis is frequently reported in free-ranging wild birds, the incidence and epidemiology of the disease in a natural setting is unknown. We recently reported endemic outbreaks of invasive aspergillosis at white stork nesting sites close to human habitation in Germany with significant subsequent breeding losses. Therefore, we hypothesized that A. fumigatus strains with higher virulence in birds may have evolved in this environment and performed the first epidemiological analysis of invasive aspergillosis in free-ranging wild birds. Sixty-one clinical and environmental A. fumigatus isolates from six affected nesting sites were genotyped by microsatellite analysis using the STRAf-assay. The isolates showed a remarkable high genomic diversity and, contrary to the initial hypothesis, clinical and environmental isolates did not cluster significantly. Interestingly, storks were infected with two to four different genotypes and in most cases both mating types MAT-1.1 and MAT-1.2 were present within the same specimen. The majority of selected clinical and environmental strains exhibited similar virulence in an in vivo infection model using embryonated chicken eggs. Noteworthy, virulence was not associated with one distinct fungal mating type. These results further support the assumption that the majority of A. fumigatus strains have the potential to cause disease in susceptible hosts. In white storks, immaturity of the immune system during the first three weeks of age may enhance susceptibility to invasive aspergillosis. Copyright © 2010 Elsevier B.V. All rights reserved.

Acute abdomen due to group A streptococcus bacteremia caused by an isolate with a mutation in the csrS gene.

PubMed

Kaneko, Masahiko; Maruta, Masaki; Shikata, Hisaharu; Hanayama, Masakazu; Ikebe, Tadayoshi

2015-11-01

Streptococcus pyogenes (group A streptococcus) is an aerobic gram-positive coccus that causes infections ranging from non-invasive pharyngitis to severely invasive necrotizing fasciitis. Mutations in csrS/csrR and rgg, negative regulator genes of group A streptococcus, are crucial factors in the pathogenesis of streptococcal toxic shock syndrome, which is a severe, invasive infection characterized by sudden onset of shock and multiorgan failure, resulting in a high mortality rate. Here we present a case of group A streptococcal bacteremia in a 28-year-old Japanese woman with no relevant previous medical history. The patient developed progressive abdominal symptoms that may have been due to spontaneous bacterial peritonitis, followed by a state of shock, which did not fulfill the proposed criteria for streptococcal toxic shock. The isolate was found to harbor a mutation in the negative regulator csrS gene, whereas the csrR and rgg genes were intact. It was noteworthy that this strain carrying a csrS mutation had caused group A streptococcal bacteremia characterized by acute abdomen as the presenting symptom in a young individual who had been previously healthy. This case indicates that group A streptococcus with csrS mutations has potential virulence factors that are associated with the onset of group A streptococcal bacteremia that does not meet the diagnostic criteria for streptococcal toxic shock syndrome. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Genome sequence analysis of emm89 Streptococcus pyogenes strains causing infections in Scotland, 2010-2016.

PubMed

Beres, Stephen B; Olsen, Randall J; Ojeda Saavedra, Matthew; Ure, Roisin; Reynolds, Arlene; Lindsay, Diane S J; Smith, Andrew J; Musser, James M

2017-12-01

Strains of type emm89 Streptococcus pyogenes have recently increased in frequency as a cause of human infections in several countries in Europe and North America. This increase has been molecular epidemiologically linked with the emergence of a new genetically distinct clone, designated clade 3. We sought to extend our understanding of this epidemic behavior by the genetic characterization of type emm89 strains responsible in recent years for an increased frequency of infections in Scotland. We sequenced the genomes of a retrospective cohort of 122 emm89 strains recovered from patients with invasive and noninvasive infections throughout Scotland during 2010 to 2016. All but one of the 122 emm89 infection isolates are of the recently emerged epidemic clade 3 clonal lineage. The Scotland isolates are closely related to and not genetically distinct from recent emm89 strains from England, they constitute a single genetic population. The clade 3 clone causes virtually all-contemporary emm89 infections in Scotland. These findings add Scotland to a growing list of countries of Europe and North America where, by whole genome sequencing, emm89 clade 3 strains have been demonstrated to be the cause of an ongoing epidemic of invasive infections and to be genetically related due to descent from a recent common progenitor.

Distribution of capsular types and antimicrobial susceptibility of invasive isolates of Streptococcus pneumoniae in Colombian children. Pneumococcal Study Group in Colombia.

PubMed

Castañeda, E; Leal, A L; Castillo, O; De La Hoz, F; Vela, M C; Arango, M; Trujillo, H; Levy, A; Gama, M E; Calle, M; Valencia, M L; Parra, W; Agudelo, N; Mejía, G I; Jaramillo, S; Montoya, F; Porras, H; Sánchez, A; Saa, D; Di Fabio, J L; Homma, A

1997-01-01

Streptococcus pneumoniae is the leading bacterial cause of childhood pneumonia in the developing world. This study describes the type distribution and antimicrobial susceptibility of invasive pneumococcal isolates from Colombian children and is part of the Sistema Regional de Vacunas (SIREVA), a PAHO regional initiative designed to determine the ideal serotype composition of a protein polysaccharide pneumococcal conjugate vaccine for use in children less than 5 years old in Latin America. In Colombia, during the study period, centres in Bogota, Medellin, and Cali collected 324 S. pneumoniae isolates from invasive diseases, 238 (73.5%) from children under the age of 2. Pneumonia was the clinical diagnosis in 41.3% cases, meningitis in 41%, and sepsis in 11.2%. The seven most frequent types included 14(21.9%), 5(10.5%), 23F(9.6%), 1(9%), 6B(9%), 19F(7.1%), and 6A(6.2%). The frequency of diminished susceptibility to penicillin (DSP) was 12%, with 8.9% of isolates showing intermediate level resistance and 3.1% showing high level resistance. Among DSP isolates, 23% were also resistant to cefotaxime, 33.3% to erythromycin, 48.7% to chloramphenicol, and 74.3% to trimethoprim/sulfamethoxazole. Multiple resistance was detected in 59% of the isolates that have DSP. Penicillin resistance was associated with types 23F (53.8%) and 14 (25.6%). These data provides information on capsular types prevalent in Colombia that will not only allow the formulation of an ideal vaccine for the region but also reinforce the need for ongoing regional surveillance.

Besnoitia besnoti lytic cycle in vitro and differences in invasion and intracellular proliferation among isolates

USDA-ARS?s Scientific Manuscript database

Background: Bovine besnoitiosis, caused by the protozoan Besnoitia besnoiti, reduces productivity and fertility of affected herds. Besnoitiosis continues to expand in Europe and no effective control tools are currently available. Experimental models are urgently needed. Herein, we describe for the f...

Bipolaris microstegii Minnis, Rossman, Kleczewki & S.L. Flory, sp. nov.

USDA-ARS?s Scientific Manuscript database

Many species of Bipolaris are significant pathogens of grasses. A new species of Bipolaris was isolated from Microstegium vimineum, an invasive plant in the USA. The fungus causes disease on Microstegium, but it also infects a wider range of hosts. Comparison of ITS and gpd sequence data to sequence...

Impact of Vancomycin MIC on Treatment Outcomes in Invasive Staphylococcus aureus Infections

PubMed Central

Song, Kyoung-Ho; Kim, Moonsuk; Kim, Chung Jong; Cho, Jeong Eun; Choi, Yun Jung; Park, Jeong Su; Ahn, Soyeon; Jang, Hee-Chang; Park, Kyung-Hwa; Jung, Sook-In; Yoon, Nara; Kim, Dong-Min; Hwang, Jeong-Hwan; Lee, Chang Seop; Lee, Jae Hoon; Kwak, Yee Gyung; Kim, Eu Suk; Park, Seong Yeon; Park, Yoonseon; Lee, Kkot Sil; Lee, Yeong-Seon

2016-01-01

ABSTRACT There are conflicting data on the association of vancomycin MIC (VAN-MIC) with treatment outcomes in Staphylococcus aureus infections. We investigated the relationship between high VAN-MIC and 30-day mortality and identified the risk factors for mortality in a large cohort of patients with invasive S. aureus (ISA) infections, defined as the isolation of S. aureus from a normally sterile site. Over a 2-year period, 1,027 adult patients with ISA infections were enrolled in 10 hospitals, including 673 (66%) patients with methicillin-resistant S. aureus (MRSA) infections. There were 200 (19.5%) isolates with high VAN-MIC (≥1.5 mg/liter) by Etest and 87 (8.5%) by broth microdilution (BMD). The all-cause 30-day mortality rate was 27.4%. High VAN-MIC by either method was not associated with all-cause 30-day mortality, and this finding was consistent across MIC methodologies and methicillin susceptibilities. We conclude that high VAN-MIC is not associated with increased risk of all-cause 30-day mortality in ISA infections. Our data support the view that VAN-MIC alone is not sufficient evidence to change current clinical practice. PMID:27956430

Itraconazole-resistant Candida auris with phospholipase, proteinase and hemolysin activity from a case of vulvovaginitis.

PubMed

Kumar, Dharmendra; Banerjee, Tuhina; Pratap, Chandra Bhan; Tilak, Ragini

2015-04-15

Since the emergence of pathogenic non-albicans Candida species, a number of new isolates have been added to the list. One such unusual species is Candida auris (C. auris), recently isolated and studied in few reports. In this study, a case of vulvovaginitis caused by Candida auris incidentally identified by molecular methods using internal transcribed spacer polymerase chain reaction (ITS PCR) is described. Antifungal susceptibility testing revealed the isolate to be resistant to itraconazole (MIC ≥ 2 µg/ml) and expressed important virulence factors including phospholipase, proteinase and hemolysin activity. The patient was successfully treated with oral fluconazole and did not have any invasive fungemia. Very few cases of this emerging pathogen have been reported. However, its isolation from clinical specimens reveals the significance of non-albicans candida species over C. albicans and the diversity of Candida spp causing infections.

Virulence properties of multidrug resistant ocular isolates of Acinetobacter baumannii.

PubMed

Talreja, Deepa; Muraleedharan, Chithra; Gunathilaka, Gayathri; Zhang, Yifan; Kaye, Keith S; Walia, Satish K; Kumar, Ashok

2014-07-01

Acinetobacter (A.) baumannii is an opportunistic pathogen and has been reported as a causative agent of ocular infections. The aim of this study is to identify virulence properties (biofilm formation, adhesion, invasion and cytotoxicity) and antibiotic resistance among A. baumannii isolates recovered from the eye. The Microscan Walk-Away®, an automated bacterial identification and susceptibility testing system was used to determine antibiotic resistance. Clonal relatedness was assessed by Pulsed-field gel electrophoresis (PFGE) and plasmid profile analysis. Conjugation experiments were carried out to determine the transfer of antibiotic resistance genes and PCR was used to confirm gene transfer. Virulence properties of the isolates were determined by biofilm formation using crystal violet and immunofluorescence staining, adherence and internalization using cultured corneal epithelial cells, and cytotoxicity by TUNEL-staining and LDH release assays. All ocular isolates (n = 12) exhibited multidrug resistant (MDR) phenotype and one of the isolate (AB12) was resistant to 18 antibiotics (β-lactam, aminoglycosides, tetracycline, chloramphenicol and quinolones). The plasmid profile analysis showed the presence of multiple plasmids in each isolate and a total of 10 different profiles were observed. However, PFGE analysis was more discriminatory which revealed 12 distinct genotypes. Antibiotic resistance (tetracycline and quinolone) was transferable from the isolate AB12 to a recipient Escherichia coli J53. Ten isolates were strong biofilm producers and the remaining two (AB5 and AB7) were moderate producers. All isolates demonstrated adherence and invasive properties towards HCECs. A similar trend was observed in their ability to cause cell death and toxicity. Our results indicate that ocular isolates of A. baumannii are biofilm producers and adherent and invasive to corneal epithelium, a first step in the pathogenesis of ocular infection. In addition, they demonstrated plasmid-mediated transfer of MDR traits making them a reservoir of resistance genes at ocular surface.

Hospital- and community-associated methicillin-resistant Staphylococcus aureus: a 6-year surveillance study of invasive infections in Chinese children.

PubMed

Qiao, Yanhong; Dong, Fang; Song, Wenqi; Wang, Lijuan; Yang, Yonghong; Shen, Xuzhuang

2013-11-01

To investigate and compare the characteristics of invasive hospital-associated (HA) and community-associated (CA) methicillin-resistant Staphylococcus aureus (MRSA) infections in Chinese children. Clinical data on 59 paediatric patients with invasive MRSA isolated from the normally sterile sites between 2006 and 2011 were obtained from the clinical MRSA surveillance database of Beijing Children's Hospital. The molecular characteristics of the invasive MRSA strains were then analysed. Invasive MRSA infections rose from 0.89 per 10 000 admissions in 2006 to 3.75 in 2011, with a notable increase in invasive CA-MRSA infections from 0 to 2.43 over the same period. The median age of the CA patients (n = 29) was 0.33 years, compared with 1.17 years for the HA patients (n = 30). Multisite infection, severe pneumonia and empyema were found in 55.2%, 73.1% and 61.5% of CA children and in 30%, 32% and 24% of HA patients, respectively. ST59-MRSA-IVa accounted for 40.7% of all isolates and the Panton-Valentine leukocidin (PVL) gene carriage rate was significantly higher in patients with necrotizing pneumonia and osteoarthritis than in those with other diseases. The incidence of paediatric invasive MRSA infection, particularly CA-MRSA infection, increased in Chinese children between 2006 and 2011. The invasive infections caused by CA-MRSA occurred more frequently in younger children with more severe pneumonia or empyema. ©2013 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Sequence type 1 group B Streptococcus, an emerging cause of invasive disease in adults, evolves by small genetic changes

PubMed Central

Flores, Anthony R.; Galloway-Peña, Jessica; Sahasrabhojane, Pranoti; Saldaña, Miguel; Yao, Hui; Su, Xiaoping; Ajami, Nadim J.; Holder, Michael E.; Petrosino, Joseph F.; Thompson, Erika; Margarit Y Ros, Immaculada; Rosini, Roberto; Grandi, Guido; Horstmann, Nicola; Teatero, Sarah; McGeer, Allison; Fittipaldi, Nahuel; Rappuoli, Rino; Baker, Carol J.; Shelburne, Samuel A.

2015-01-01

The molecular mechanisms underlying pathogen emergence in humans is a critical but poorly understood area of microbiologic investigation. Serotype V group B Streptococcus (GBS) was first isolated from humans in 1975, and rates of invasive serotype V GBS disease significantly increased starting in the early 1990s. We found that 210 of 229 serotype V GBS strains (92%) isolated from the bloodstream of nonpregnant adults in the United States and Canada between 1992 and 2013 were multilocus sequence type (ST) 1. Elucidation of the complete genome of a 1992 ST-1 strain revealed that this strain had the highest homology with a GBS strain causing cow mastitis and that the 1992 ST-1 strain differed from serotype V strains isolated in the late 1970s by acquisition of cell surface proteins and antimicrobial resistance determinants. Whole-genome comparison of 202 invasive ST-1 strains detected significant recombination in only eight strains. The remaining 194 strains differed by an average of 97 SNPs. Phylogenetic analysis revealed a temporally dependent mode of genetic diversification consistent with the emergence in the 1990s of ST-1 GBS as major agents of human disease. Thirty-one loci were identified as being under positive selective pressure, and mutations at loci encoding polysaccharide capsule production proteins, regulators of pilus expression, and two-component gene regulatory systems were shown to affect the bacterial phenotype. These data reveal that phenotypic diversity among ST-1 GBS is mainly driven by small genetic changes rather than extensive recombination, thereby extending knowledge into how pathogens adapt to humans. PMID:25941374

Sequence type 1 group B Streptococcus, an emerging cause of invasive disease in adults, evolves by small genetic changes.

PubMed

Flores, Anthony R; Galloway-Peña, Jessica; Sahasrabhojane, Pranoti; Saldaña, Miguel; Yao, Hui; Su, Xiaoping; Ajami, Nadim J; Holder, Michael E; Petrosino, Joseph F; Thompson, Erika; Margarit Y Ros, Immaculada; Rosini, Roberto; Grandi, Guido; Horstmann, Nicola; Teatero, Sarah; McGeer, Allison; Fittipaldi, Nahuel; Rappuoli, Rino; Baker, Carol J; Shelburne, Samuel A

2015-05-19

The molecular mechanisms underlying pathogen emergence in humans is a critical but poorly understood area of microbiologic investigation. Serotype V group B Streptococcus (GBS) was first isolated from humans in 1975, and rates of invasive serotype V GBS disease significantly increased starting in the early 1990s. We found that 210 of 229 serotype V GBS strains (92%) isolated from the bloodstream of nonpregnant adults in the United States and Canada between 1992 and 2013 were multilocus sequence type (ST) 1. Elucidation of the complete genome of a 1992 ST-1 strain revealed that this strain had the highest homology with a GBS strain causing cow mastitis and that the 1992 ST-1 strain differed from serotype V strains isolated in the late 1970s by acquisition of cell surface proteins and antimicrobial resistance determinants. Whole-genome comparison of 202 invasive ST-1 strains detected significant recombination in only eight strains. The remaining 194 strains differed by an average of 97 SNPs. Phylogenetic analysis revealed a temporally dependent mode of genetic diversification consistent with the emergence in the 1990s of ST-1 GBS as major agents of human disease. Thirty-one loci were identified as being under positive selective pressure, and mutations at loci encoding polysaccharide capsule production proteins, regulators of pilus expression, and two-component gene regulatory systems were shown to affect the bacterial phenotype. These data reveal that phenotypic diversity among ST-1 GBS is mainly driven by small genetic changes rather than extensive recombination, thereby extending knowledge into how pathogens adapt to humans.

Strategies for conserving native salmonid populations at risk from nonnative fish invasions: tradeoffs in using barriers to upstream movement

Treesearch

Kurt D. Fausch; Bruce E. Rieman; Michael Young; Jason B. Dunham

2006-01-01

Native salmonid populations in the inland West are often restricted to small isolated habitats at risk from invasion by nonnative salmonids. However, further isolating these populations using barriers to prevent invasions can increase their extinction risk. This monograph reviews the state of knowledge about this tradeoff between invasion and isolation. We present a...

Pneumonia research in Papua New Guinea: 1967-1986.

PubMed

Riley, Ian D

2010-01-01

Between 1967 and 1985 research on pneumonia in Papua New Guinea (PNG) was fundamental not only to standard treatments of disease in PNG, but also to the establishment of the World Health Organization's global Program for Control of Acute Respiratory Infections. Pneumonia was the leading cause of death in both population-based and hospital studies. Research that began in 1967 revealed a pattern of disease in adults reminiscent of that seen in industrialized countries in the early 20th century. Streptococcus pneumoniae (pneumococcus) was the predominant causative organism. Pneumococci were commensals of the upper respiratory tract that invaded first the lungs and then the blood stream. Some serotypes were more invasive than others and case fatality increased with deeper levels of invasion. The pandemic of Hong Kong (H3N2) influenza spread to the Southern Highlands in 1969 resulting in 2000 deaths. The conclusion that pneumococcal pneumonia had been the principal cause of death led to the establishment of a pneumonia research unit in Tari. A field trial of pneumococcal polysaccharide vaccine showed the vaccine to be most effective in preventing invasive disease. Vaccination reduced pneumonia mortality by 44% in previously healthy adults. The epidemiological situation was more complex in children than in adults because many different species and serotypes of bacteria could be isolated from lung aspirate. Although many of these organisms would normally have been regarded as non-pathogenic, S. pneumoniae and Haemophilus influenzae, recognized pathogens, were the principal causes of severe morbidity and mortality. The same principles of carriage of and invasion by upper respiratory commensals applied as much to children as they did to adults, and the rank order of invasive serotypes of S. pneumoniae and H. influenzae was the same in different age groups. Slow maturation of a child's immune system meant, however, that children could be susceptible to invasion by particular serotypes. Infants were frequently colonized by pathogenic bacteria within days of birth. Nasal discharge, which was extremely common, was most probably a result of domestic smoke pollution and low standards of hygiene. Aspiration of infected secretions was a likely explanation for the variety of organisms isolated from lung aspirate. A trial of pneumococcal polysaccharide vaccine showed the vaccine to be effective in preventing death from pneumonia in children 6-9 months of age provided pneumonia was not associated with other causes of death; this result was shown to be consistent with the principles of infection and invasion described above. Principles of antibiotic therapy for child pneumonia were also established at this time.

Beta-haemolytic group A, C and G streptococcal infections in Western Norway: a 15-year retrospective survey.

PubMed

Oppegaard, O; Mylvaganam, H; Kittang, B R

2015-02-01

Pyogenic streptococci cause significant morbidity and mortality, and the incidence of invasive group C and G streptococcal disease appears to be increasing. In this retrospective study we describe the epidemiological characteristics of invasive group A, C and G, along with non-invasive group C and G streptococcal infections in Western Norway from 1999 to 2013. A total of 512 invasive streptococcal infections were identified, of these 297 (58%) were group A (GAS), 24 (5%) group C (GCS) and 188 (37%) group G streptococci (GGS). In the non-invasive group, 4935 GCS and GGS-infections were identified. GCS and GGS were treated as one group (GCGS) for statistical purposes. All microbial categories displayed increasing incidence with age, seasonal variation and a male predominance. The incidence of invasive GCGS infections increased significantly from 1.4/100,000 inhabitants in 1999 to 6.3/100,000 in 2013 (p <0.001). Conversely, the annual rates of invasive GAS infection exhibited marked fluctuations, ranging from 2.7/100,000 (2000) to 8.3/100,000 (1999), but no significant temporal trends were observed. The incidence of non-invasive GCGS infections decreased significantly during the study period (p <0.001). The most frequently encountered emm-types among the 209 iGAS-isolates analysed were emm1 (24%), emm3 (14%) and emm28 (14%); whereas stG643 (19%), stG485 (15%) and stG6 (13%) were most prevalent among the 122 iGCGS-isolates available for typing. The increasing burden of invasive β-haemolytic streptococcal disease in our community calls for sustained attentiveness to the clinical and molecular aspects of GAS, GCS and GGS infections. Copyright © 2014 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Ten years of Hib vaccination in Italy: prevalence of non-encapsulated Haemophilus influenzae among invasive isolates and the possible impact on antibiotic resistance.

PubMed

Giufrè, Maria; Cardines, Rita; Caporali, Maria Grazia; Accogli, Marisa; D'Ancona, Fortunato; Cerquetti, Marina

2011-05-17

The introduction of Haemophilus influenzae type b (Hib) conjugate vaccines has greatly reduced the incidence of invasive Hib disease. However, concern exists about the possible emergence of "strain replacement". We report the epidemiology and characterization of isolates from invasive H. influenzae disease in Italy through 2007-2009, 10 years after Hib vaccination was introduced. Invasive H. influenzae disease cases were detected through the National Surveillance of Invasive Bacterial Disease. Seventy-eight H. influenzae strains were serotyped and tested for antimicrobial susceptibility. Genetic basis of resistance to β-lactams was investigated. The annual incidence of invasive H. influenzae infection was 0.06/100,000 in 2007, 0.08/100,000 in 2008 and 0.09/100,000 in 2009 in all age groups. A slight increase in disease incidence has been observed in adults ≥65 years since 2007. Nonencapsulated (ncHi) predominated among H. influenzae isolates from all age groups: 61.5%, 76.0%, and 75.0% for <5, 5-64 and ≥65 years, respectively. Although ncHi mainly caused bacteremia, meningitis due to ncHi increased in comparison with previous data (38.6% in 2007-2009 vs. 26.2% 1997-2002). Prevalence of encapsulated non-Hib strains grew significantly (4.1% in 1997-2002 vs.16.7% in 2007-2009; p<0.001), although they remained rare. Resistance to ampicillin mediated by β-lactamase declined, but that due to altered penicillin-binding protein 3 increased. In conclusion, routine use of Hib vaccines produced both a drastic decrease in the number of invasive H. influenzae cases and epidemiological changes in disease. Overall, pediatric H. influenzae disease has become less common whereas there has been a slight increase of disease in the elderly. A marked change in the predominant serotype from Hib to ncHi has occurred. Changes in the H. influenzae population moderately affected antibiotic resistance trends. Copyright © 2011 Elsevier Ltd. All rights reserved.

Evolving epidemiology of invasive Haemophilus infections in the post-vaccination era: results from a long-term population-based study.

PubMed

Berndsen, M R; Erlendsdóttir, H; Gottfredsson, M

2012-09-01

Historically, Haemophilus influenzae (Hi) serotype b (Hib) caused most invasive Haemophilus infections worldwide, mainly in children. In 1989 routine childhood vaccination against Hib was initiated in Iceland. We conducted a population-based study of all patients in the country with Haemophilus spp. isolated from sterile sites (n = 202), from 1983 to 2008. Epidemiology, clinical characteristics of the infections and serotypes of the isolates were compared during the pre-vaccination (1983-1989) and post-vaccination era (1990-2008). Following the vaccination, the overall incidence of Hib decreased from 6.4 to 0.3/100,000 per year (p <0.05) whereas the incidence did not change significantly for infections caused by Haemophilus sensu lato not serotype b, hereafter referred to as non-type b Hi (0.9 vs 1.2, respectively). The most frequent diagnosis prior to 1990 was meningitis caused by Hib, which was subsequently replaced by pneumonia and bacteraemia caused by non-type b Hi. Most commonly, non-type b Hi were non-typeable (NTHi; 40/59), followed by Hi serotype f (14/59) and Hi serotype a (3/59). Pregnancy was associated with a markedly increased susceptibility to invasive Haemophilus infections (RR 25.7; 95% CI 8.0-95.9, p <0.0001) compared with non-pregnant women. The case fatality rate for Hib was 2.4% but 14% for non-type b Hi, highest at the extremes of age. Hib vaccination gives young children excellent protection and decreases incidence in the elderly due to herd effect in the community. Replacement with other species or serotypes has not been noted. Pregnant women are an overlooked risk group. © 2011 The Authors. Clinical Microbiology and Infection © 2011 European Society of Clinical Microbiology and Infectious Diseases.

Haemophilus influenzae type-b and non-b-type invasive diseases in urban children (<5years) of Bangladesh: implications for therapy and vaccination.

PubMed

Rahman, Mahbubur; Hossain, Shahadat; Baqui, Abdullah Hel; Shoma, Shereen; Rashid, Harunur; Nahar, Nazmun; Zaman, Mohammed Khalequ; Khatun, Farida

2008-03-01

To prospectively study the epidemiology and antibiotic resistance of Haemophilus infuenzae isolates from invasive infections in children. Children (<5years) with pneumonia, meningitis and septicemia from three hospitals in Dhaka, Bangladesh were enrolled (1999-2003); clinical and laboratory data, and blood for cultures were collected. Cerebrospinal fluid (CSF) of meningitis cases was analyzed (Gram stain, culture and biochemical tests). Hib antigen was detected by latex agglutination (LA) in culture-negative pyogenic CSF and PCR was done for bexA gene in culture- and LA-negative pyogenic CSF. Antibiotic susceptibility was determined by E-Tests and beta-lactamase by nitrocefin stick. Seventy-three cases of H. influenzae infections (46 of 293 meningitis cases, 25 of 1493 pneumonia cases, 2 of 48 septicemia cases) were detected; 63%, 34% and 3% of them had meningitis, pneumonia and septicemia respectively. H. influenzae type b (Hib) caused infections in 80.8% of cases (60.3% meningitis, 20.5% pneumonia). Most (86%) infections clustered in 4-12month infants. The case-fatality in pneumonia was 8% compared to 19% in meningitis. H. influenzae isolates from pneumonia and meningitis children were equally resistant to antibiotics (46% vs 43%). Of 10 drugs tested, isolates were resistant to ampicillin (31%), chloramphenicol (42%), trimethoprim-sulfamethoxazole (44%) and azithromycin (1.4%). Multidrug-resistant (MDR) strains were equally prevalent in Hib (31%) and non-b-type (29%) isolates, and in pneumonia (31%) and meningitis (34%) cases. None was resistant to amoxicillin-clavulanate, ceftriaxone, ciprofloxacin, levofloxacin, moxifloxacin, and gatifloxacin. Of all H. influenzae infections, 40%, 4.4% and 100% of pneumonia, meningitis and septicemia cases were caused by other serotypes or non-typeable strains. All ampicillin-resistant-strains produced beta-lactamase without detection of beta-lactamase-negative-ampicillin-resistant (BLNAR) strains. Hib is a leading cause of invasive bacterial infections in infants. Multidrug-resistant H. influenzae is common and requires amoxicillin-clavulanate, ceftriaxone or azithromycin as empirical therapy with specific recommendation for use of ceftriaxone for treatment of meningitis particularly MDR cases. New fluoroquinolines has potential utility. An effective national Hib vaccination programme is essential in Bangladesh although non-Hib infections will remain an issue.

Ustilago echinata: Infection in a Mixed Martial Artist Following an Open Fracture.

PubMed

Stewart, Ethan; Waldman, Sarah; Sutton, Deanna A; Sanders, Carmita; Lindner, Jonathan; Fan, Hongxin; Wiederhold, Nathan P; Thompson, George R

2016-04-01

Ustilago, a common fungal parasite of grains, is infrequently isolated as a pathogen in humans. We describe a case of Ustilago echinata infection following an open distal tibia fracture, review the current literature of this genus as a cause of invasive fungal infection in humans, and discuss management issues.

Haemophilus haemolyticus Isolates Causing Clinical Disease

PubMed Central

Wang, Xin; Briere, Elizabeth C.; Katz, Lee S.; Cohn, Amanda C.; Clark, Thomas A.; Messonnier, Nancy E.; Mayer, Leonard W.

2012-01-01

We report seven cases of Haemophilus haemolyticus invasive disease detected in the United States, which were previously misidentified as nontypeable Haemophilus influenzae. All cases had different symptoms and presentations. Our study suggests that a testing scheme that includes reliable PCR assays and standard microbiological methods should be used in order to improve H. haemolyticus identification. PMID:22573587

Haemophilus haemolyticus isolates causing clinical disease.

PubMed

Anderson, Raydel; Wang, Xin; Briere, Elizabeth C; Katz, Lee S; Cohn, Amanda C; Clark, Thomas A; Messonnier, Nancy E; Mayer, Leonard W

2012-07-01

We report seven cases of Haemophilus haemolyticus invasive disease detected in the United States, which were previously misidentified as nontypeable Haemophilus influenzae. All cases had different symptoms and presentations. Our study suggests that a testing scheme that includes reliable PCR assays and standard microbiological methods should be used in order to improve H. haemolyticus identification.

Investigating the Relatedness of Enteroinvasive Escherichia coli to Other E. coli and Shigella Isolates by Using Comparative Genomics

PubMed Central

Hazen, Tracy H.; Leonard, Susan R.; Lampel, Keith A.; Lacher, David W.

2016-01-01

Enteroinvasive Escherichia coli (EIEC) is a unique pathovar that has a pathogenic mechanism nearly indistinguishable from that of Shigella species. In contrast to isolates of the four Shigella species, which are widespread and can be frequent causes of human illness, EIEC causes far fewer reported illnesses each year. In this study, we analyzed the genome sequences of 20 EIEC isolates, including 14 first described in this study. Phylogenomic analysis of the EIEC genomes demonstrated that 17 of the isolates are present in three distinct lineages that contained only EIEC genomes, compared to reference genomes from each of the E. coli pathovars and Shigella species. Comparative genomic analysis identified genes that were unique to each of the three identified EIEC lineages. While many of the EIEC lineage-specific genes have unknown functions, those with predicted functions included a colicin and putative proteins involved in transcriptional regulation or carbohydrate metabolism. In silico detection of the Shigella virulence plasmid (pINV), which is essential for the invasion of host cells, demonstrated that a form of pINV was present in nearly all EIEC genomes, but the Mxi-Spa-Ipa region of the plasmid that encodes the invasion-associated proteins was absent from several of the EIEC isolates. The comparative genomic findings in this study support the hypothesis that multiple EIEC lineages have evolved independently from multiple distinct lineages of E. coli via the acquisition of the Shigella virulence plasmid and, in some cases, the Shigella pathogenicity islands. PMID:27271741

Investigating the Relatedness of Enteroinvasive Escherichia coli to Other E. coli and Shigella Isolates by Using Comparative Genomics.

PubMed

Hazen, Tracy H; Leonard, Susan R; Lampel, Keith A; Lacher, David W; Maurelli, Anthony T; Rasko, David A

2016-08-01

Enteroinvasive Escherichia coli (EIEC) is a unique pathovar that has a pathogenic mechanism nearly indistinguishable from that of Shigella species. In contrast to isolates of the four Shigella species, which are widespread and can be frequent causes of human illness, EIEC causes far fewer reported illnesses each year. In this study, we analyzed the genome sequences of 20 EIEC isolates, including 14 first described in this study. Phylogenomic analysis of the EIEC genomes demonstrated that 17 of the isolates are present in three distinct lineages that contained only EIEC genomes, compared to reference genomes from each of the E. coli pathovars and Shigella species. Comparative genomic analysis identified genes that were unique to each of the three identified EIEC lineages. While many of the EIEC lineage-specific genes have unknown functions, those with predicted functions included a colicin and putative proteins involved in transcriptional regulation or carbohydrate metabolism. In silico detection of the Shigella virulence plasmid (pINV), which is essential for the invasion of host cells, demonstrated that a form of pINV was present in nearly all EIEC genomes, but the Mxi-Spa-Ipa region of the plasmid that encodes the invasion-associated proteins was absent from several of the EIEC isolates. The comparative genomic findings in this study support the hypothesis that multiple EIEC lineages have evolved independently from multiple distinct lineages of E. coli via the acquisition of the Shigella virulence plasmid and, in some cases, the Shigella pathogenicity islands. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Primary Cutaneous Mucormycosis Caused by Rhizopus oryzae: A Case Report and Review of Literature.

PubMed

Rodríguez-Lobato, Erika; Ramírez-Hobak, Lourdes; Aquino-Matus, Jorge E; Ramírez-Hinojosa, Juan P; Lozano-Fernández, Víctor H; Xicohtencatl-Cortes, Juan; Hernández-Castro, Rigoberto; Arenas, Roberto

2017-04-01

Mucormycosis is an invasive infection caused by opportunistic fungi. Rhizopus, Lichtheimia, Mucor and Rhizomucor are the most common isolated genera. Primary cutaneous mucormycosis is usually related to traumatic injuries, but immunocompromised cases are associated with underlying conditions such as diabetes mellitus and malignancies. The treatment of choice is surgical debridement and liposomal amphotericin B. We present a 40-year-old male with fever and a painful necrotic lesion on the middle back and history of poorly controlled diabetes mellitus. Rhizopus oryzae was isolated and identified using an internal transcribed spacer regions ITS1 and ITS2. An initial good response to treatment was observed; however, 7 days later a diabetic ketoacidosis due to poor adherence to treatment caused a lethal outcome.

Invasive infection caused by Klebsiella pneumoniae is a disease affecting patients with high comorbidity and associated with high long-term mortality

PubMed Central

Nauclér, P.; Kalin, M.; Giske, C. G.

2018-01-01

Klebsiella pneumoniae (KP) is after Escherichia coli (EC) the most common gram-negative species causing invasive infections. Herein, we analyzed risk factors and prognosis in invasive infections caused by KP versus EC, in an area with low antimicrobial resistance. Moreover, we compared antimicrobial resistance and relative prevalence of KP and EC (KP/EC-ratio) in different European countries, using EARS-Net data. Adult patients admitted to Karolinska University Hospital 2006–2012 with invasive infection caused by KP (n = 599) were matched regarding sex and age with patients infected by EC. The medical records were retrospectively reviewed. Comorbidity was adjusted for with multivariable analysis. European data were retrieved from the EARS-Net database. No differences were observed in 7- and 30-day mortality between the groups. The 90-day mortality was significantly higher in the KP cohort (26% versus 17%, p<0.001), but not after adjusting for comorbidity. Malignancy was seen in 53% of the patients with KP versus 38% with EC, OR 1.86 (1.34–2.58). A significant increase in the rate of ESBL-production was observed in EC, but not in KP. The KP/EC-ratio remained stable. In contrast, European data showed increasing percentages of isolates non-susceptible to third-generation cephalosporins in EC and KP, and increasing KP/EC-ratio. Invasive infection caused by KP is a disease affecting patients with high comorbidity and associated with high 90-d mortality. The stable KP/EC-ratio and low occurrence of antimicrobial resistance in data from Karolinska University Hospital compared to aggregate data from 20 EARS-Net countries could be related to absence of clonal spread of multidrug-resistant KP. PMID:29624618

Antimicrobial Resistance and Molecular Investigation of H2S-Negative Salmonella enterica subsp. enterica serovar Choleraesuis Isolates in China.

PubMed

Xie, Jing; Yi, Shengjie; Zhu, Jiangong; Li, Peng; Liang, Beibei; Li, Hao; Yang, Xiaoxia; Wang, Ligui; Hao, Rongzhang; Jia, Leili; Wu, Zhihao; Qiu, Shaofu; Song, Hongbin

2015-01-01

Salmonella enterica subsp. enterica serovar Choleraesuis is a highly invasive pathogen of swine that frequently causes serious outbreaks, in particular in Asia, and can also cause severe invasive disease in humans. In this study, 21 S. Choleraesuis isolates, detected from 21 patients with diarrhea in China between 2010 and 2011, were found to include 19 H2S-negative S. Choleraesuis isolates and two H2S-positive isolates. This is the first report of H2S-negative S. Choleraesuis isolated from humans. The majority of H2S-negative isolates exhibited high resistance to ampicillin, chloramphenicol, gentamicin, tetracycline, ticarcillin, and trimethoprim-sulfamethoxazole, but only six isolates were resistant to norfloxacin. In contrast, all of the isolates were sensitive to cephalosporins. Fifteen isolates were found to be multidrug resistant. In norfloxacin-resistant isolates, we detected mutations in the gyrA and parC genes and identified two new mutations in the parC gene. Pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and clustered regularly interspaced short palindromic repeat (CRISPR) analysis were employed to investigate the genetic relatedness of H2S-negative and H2S-positive S. Choleraesuis isolates. PFGE revealed two groups, with all 19 H2S-negative S. Choleraesuis isolates belonging to Group I and H2S-positive isolates belonging to Group II. By MLST analysis, the H2S-negative isolates were all found to belong to ST68 and H2S-positive isolates belong to ST145. By CRISPR analysis, no significant differences in CRISPR 1 were detected; however, one H2S-negative isolate was found to contain three new spacers in CRISPR 2. All 19 H2S-negative isolates also possessed a frame-shift mutation at position 760 of phsA gene compared with H2S-positive isolates, which may be responsible for the H2S-negative phenotype. Moreover, the 19 H2S-negative isolates have similar PFGE patterns and same mutation site in the phsA gene, these results indicated that these H2S-negative isolates may have been prevalent in China. These findings suggested that surveillance should be increased of H2S-negative S. Choleraesuis in China.

Antimicrobial Resistance and Molecular Investigation of H2S-Negative Salmonella enterica subsp. enterica serovar Choleraesuis Isolates in China

PubMed Central

Li, Peng; Liang, Beibei; Li, Hao; Yang, Xiaoxia; Wang, Ligui; Hao, Rongzhang; Jia, Leili; Wu, Zhihao; Qiu, Shaofu; Song, Hongbin

2015-01-01

Salmonella enterica subsp. enterica serovar Choleraesuis is a highly invasive pathogen of swine that frequently causes serious outbreaks, in particular in Asia, and can also cause severe invasive disease in humans. In this study, 21 S. Choleraesuis isolates, detected from 21 patients with diarrhea in China between 2010 and 2011, were found to include 19 H2S-negative S. Choleraesuis isolates and two H2S-positive isolates. This is the first report of H2S-negative S. Choleraesuis isolated from humans. The majority of H2S-negative isolates exhibited high resistance to ampicillin, chloramphenicol, gentamicin, tetracycline, ticarcillin, and trimethoprim-sulfamethoxazole, but only six isolates were resistant to norfloxacin. In contrast, all of the isolates were sensitive to cephalosporins. Fifteen isolates were found to be multidrug resistant. In norfloxacin-resistant isolates, we detected mutations in the gyrA and parC genes and identified two new mutations in the parC gene. Pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and clustered regularly interspaced short palindromic repeat (CRISPR) analysis were employed to investigate the genetic relatedness of H2S-negative and H2S-positive S. Choleraesuis isolates. PFGE revealed two groups, with all 19 H2S-negative S. Choleraesuis isolates belonging to Group I and H2S-positive isolates belonging to Group II. By MLST analysis, the H2S-negative isolates were all found to belong to ST68 and H2S-positive isolates belong to ST145. By CRISPR analysis, no significant differences in CRISPR 1 were detected; however, one H2S-negative isolate was found to contain three new spacers in CRISPR 2. All 19 H2S-negative isolates also possessed a frame-shift mutation at position 760 of phsA gene compared with H2S-positive isolates, which may be responsible for the H2S-negative phenotype. Moreover, the 19 H2S-negative isolates have similar PFGE patterns and same mutation site in the phsA gene, these results indicated that these H2S-negative isolates may have been prevalent in China. These findings suggested that surveillance should be increased of H2S-negative S. Choleraesuis in China. PMID:26431037

Genomic comparison of multi-drug resistant invasive and colonizing Acinetobacter baumannii isolated from diverse human body sites reveals genomic plasticity.

PubMed

Sahl, Jason W; Johnson, J Kristie; Harris, Anthony D; Phillippy, Adam M; Hsiao, William W; Thom, Kerri A; Rasko, David A

2011-06-04

Acinetobacter baumannii has recently emerged as a significant global pathogen, with a surprisingly rapid acquisition of antibiotic resistance and spread within hospitals and health care institutions. This study examines the genomic content of three A. baumannii strains isolated from distinct body sites. Isolates from blood, peri-anal, and wound sources were examined in an attempt to identify genetic features that could be correlated to each isolation source. Pulsed-field gel electrophoresis, multi-locus sequence typing and antibiotic resistance profiles demonstrated genotypic and phenotypic variation. Each isolate was sequenced to high-quality draft status, which allowed for comparative genomic analyses with existing A. baumannii genomes. A high resolution, whole genome alignment method detailed the phylogenetic relationships of sequenced A. baumannii and found no correlation between phylogeny and body site of isolation. This method identified genomic regions unique to both those isolates found on the surface of the skin or in wounds, termed colonization isolates, and those identified from body fluids, termed invasive isolates; these regions may play a role in the pathogenesis and spread of this important pathogen. A PCR-based screen of 74 A. baumanii isolates demonstrated that these unique genes are not exclusive to either phenotype or isolation source; however, a conserved genomic region exclusive to all sequenced A. baumannii was identified and verified. The results of the comparative genome analysis and PCR assay show that A. baumannii is a diverse and genomically variable pathogen that appears to have the potential to cause a range of human disease regardless of the isolation source.

Genomics of an emerging clone of Salmonella serovar Typhimurium ST313 from Nigeria and the Democratic Republic of Congo.

PubMed

Leekitcharoenphon, Pimlapas; Friis, Carsten; Zankari, Ea; Svendsen, Christina Aaby; Price, Lance B; Rahmani, Maral; Herrero-Fresno, Ana; Fashae, Kayode; Vandenberg, Olivier; Aarestrup, Frank M; Hendriksen, Rene S

2013-10-15

Salmonella enterica serovar Typhimurium ST313 is an invasive and phylogenetically distinct lineage present in sub-Saharan Africa. We report the presence of S. Typhimurium ST313 from patients in the Democratic Republic of Congo and Nigeria. Eighteen S. Typhimurium ST313 isolates were characterized by antimicrobial susceptibility testing, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). Additionally, six of the isolates were characterized by whole genome sequence typing (WGST). The presence of a putative virulence determinant was examined in 177 Salmonella isolates belonging to 57 different serovars. All S. Typhimurium ST313 isolates harbored resistant genes encoded by blaTEM1b, catA1, strA/B, sul1, and dfrA1. Additionally, aac(6')1aa gene was detected. Phylogenetic analyses revealed close genetic relationships among Congolese and Nigerian isolates from both blood and stool. Comparative genomic analyses identified a putative virulence fragment (ST313-TD) unique to S. Typhimurium ST313 and S. Dublin. We showed in a limited number of isolates that S. Typhimurium ST313 is a prevalent sequence-type causing gastrointestinal diseases and septicemia in patients from Nigeria and DRC. We found three distinct phylogenetic clusters based on the origin of isolation suggesting some spatial evolution. Comparative genomics showed an interesting putative virulence fragment (ST313-TD) unique to S. Typhimurium ST313 and invasive S. Dublin.

[Antibiotic resistance analysis of Streptococcus pneumoniae isolates from the hospitalized children in Shanxi Children's Hospital from 2012 to 2014].

PubMed

Ge, L L; Han, Z Y; Liu, A H; Zhu, L; Meng, J H

2017-02-02

Objective: To investigate the antibiotic resistance status of Streptococcus pneumoniae isolates from hospitalized children in Shanxi Children's Hospital. Method: E-test and Kirby-Bauer methods were applied to determine drug sensitivity of the isolates collected from the body fluid specimens of hospitalized children in Shanxi Children's Hospital from January 2012 to December 2014. The antimicrobial sensitivity and minimum inhibitory concentration (MIC) of Streptococcus pneumoniae to the conventional antibiotics were analyzed, in order to compare the annual trends of non-invasive isolates, while the differentiation of sensitivity from specimens. The comparison of rates was performed by Chi-squared test and Fisher's exact test. Result: A total of 671 isolates of streptococcus pneumoniae were obtained, which could be divided as non-invasive isolates(607), invasive isolates from non-cerebrospinal fluid(non-CSF)(40) and invasive isolates from cerebrospinal fluid(CSF)(24). The antimicrobial sensitivity(isolates(%)) of the 671 isolates were respectively vancomycin 671(100.0%), linezolid 671(100.0%), levofloxacin 665(99.1%), penicillin 595(88.7%), ceftriaxone 516(76.9%), cefotaxime 512(76.3%), sulfamethoxazole-trimethoprin(SMZ-TMP) 103(15.4%), clindamycin 28(4.2%), tetracycline 26(3.9%), erythromycin 12(1.8%). From 2012 to 2014, the susceptibility rates of non-invasive isolates to penicillin every year were 95.0%(96/101), 97.3%(110/113), 87.3%(343/393), respectively, and there was significant difference among the three years(χ(2)=13.266, P <0.05), and the values of MIC(50, )MIC(90) and the maximum values of MIC(mg/L) of penicillin were 0.064, 2.000, 6.000 in 2012, which grew up to 1.000, 3.000, 16.000 in 2014. There was no significant difference in the susceptibility rate of non-invasive isolates to ceftriaxone and cefotaxime during these three years, (χ(2)=1.172, 1.198, both P >0.05). On the other hand, the values of MIC(50, )MIC(90) and the maximum value of MIC(mg/L) of ceftriaxone and cefotaxime both increased from 0.500, 2.000, 8.000 in 2012 to 0.750, 4.000, 32.000 in 2014. There was no significant difference in the susceptibility rate of non-invasive isolates to the rest antibiotic. Based on the same examining standard of CSF, the antimicrobial sensitivity(isolates(%)) of the non-invasive isolates to ceftriaxone, cefotaxime, SMZ-TMP were respectively 281(46.3%), 278(45.8%), 78(12.9%), were significantly lower than the susceptibility rate of the invasive isolates from non-CSF (28(70%), 28(70%), 14(35%), χ(2)=8.453, 8.817, 15.094, all P <0.012 5), and lower than the invasive isolates from CSF (18(75%), 18(75%), χ(2)=7.631, 7.905, P <0.012 5; 11(45.8%), P =0.001). The sensitivity of the isolates to the rest antibiotics were similar( P >0.05). Conclusion: More than 95.0% strains of the streptococcus pneumoniae isolates from the hospitalized children in Shanxi Children's Hospital were sensitive to vancomycin, linezolid, levofloxacin, and the susceptibility rate of penicillin, ceftriaxone, cefotaxime were 88.7%, 76.9%, 76.3%. However, less than 20.0% of streptococcus pneumoniae were sensitive to erythromycin, clindamycin, SMZ-TMP and tetracycline. The susceptibility rate of penicillin of non-invasive Streptococcus pneumoniae declined by these years, and the differences to ceftriaxone and cefotaxime can be neglected, but the values of MIC(50, )MIC(90) and the maximum value of MIC of all were linearly rising. The susceptibility rate of antibiotics to ceftriaxone and cefotaxime of the non-invasive isolates was lower than the invasive isolates.

Phenotypes and genotypes of erythromycin-resistant Streptococcus pyogenes strains isolated from invasive and non-invasive infections from Mexico and the USA during 1999–2010

PubMed Central

Villaseñor-Sierra, Alberto; Katahira, Eva; Jaramillo-Valdivia, Abril N.; de los Angeles Barajas-García, María; Bryant, Amy; Morfín-Otero, Rayo; Márquez-Díaz, Francisco; Tinoco, Juan Carlos; Sánchez-Corona, José; Stevens, Dennis L.

2012-01-01

Summary Objective To compare the prevalence, phenotypes, and genes responsible for erythromycin resistance among Streptococcus pyogenes isolates from Mexico and the USA. Methods Eighty-nine invasive and 378 non-invasive isolates from Mexico, plus 148 invasive, 21 non-invasive, and five unclassified isolates from the USA were studied. Susceptibilities to penicillin, erythromycin, clindamycin, ceftriaxone, and vancomycin were evaluated according to Clinical and Laboratory Standards Institute (CLSI) standards. Phenotypes of erythromycin resistance were identified by triple disk test, and screening for mefA, ermTR, and ermB genes was carried out by PCR. Results All isolates were susceptible to penicillin, ceftriaxone, and vancomycin. Erythromycin resistance was found in 4.9% of Mexican strains and 5.2% of USA strains. Phenotypes in Mexican strains were 95% M and 5% cMLS; in strains from the USA, phenotypes were 33.3% iMLS, 33.3% iMLS-D, and 33.3% M. Erythromycin resistance genes in strains from Mexico were mefA (95%) and ermB (5%); USA strains harbored ermTR (56%), mefA (33%), and none (11%). In Mexico, all erythromycin-resistant strains were non-invasive, whereas 89% of strains from the USA were invasive. Conclusions Erythromycin resistance continues to exist at low levels in both Mexico and the USA, although the genetic mechanisms responsible differ between the two nations. These genetic differences may be related to the invasive character of the S. pyogenes isolated. PMID:22217469

Analysis of Haemophilus influenzae serotype f isolated from three Japanese children with invasive H. influenzae infection.

PubMed

Hoshino, Tadashi; Hachisu, Yushi; Kikuchi, Takashi; Tokutake, Shoko; Okui, Hideyuki; Kutsuna, Satoru; Fukasawa, Chie; Murayama, Kei; Oohara, Asami; Shimizu, Hiroyuki; Ito, Midori; Takahashi, Yoshiko; Ishiwada, Naruhiko

2015-04-01

In Japan, publicly subsidized Haemophilus influenzae serotype b vaccines became available in 2011; consequently, the incidence of invasive H. influenzae infection in paediatric patients of less than 5 years of age decreased dramatically. In 2013, the first case of H. influenzae serotype f (Hif) meningitis in a Japanese infant was reported, and another case of Hif meningitis in a Japanese infant was observed in 2013. We experienced a fatal paediatric case of Hif bacteraemia in 2004; therefore, we conducted an analysis of the three Hif strains isolated from these three Japanese children with invasive Hif infections. All three strains were β-lactamase-non-producing, ampicillin-sensitive strains, with MICs of 1 µg ml(-1) or less. However, one of the three strains showed slightly elevated MICs for ampicillin (1 µg ml(-1)), cefotaxime (0.25 µg ml(-1)) and meropenem (0.13 µg ml(-1)). A molecular analysis by multilocus sequence typing identified all three strains as sequence type (ST) 124, which is a predominant invasive Hif strain in many countries. SmaI-digested PFGE showed variable DNA fragmentation patterns among the strains, suggesting that some highly virulent strains have originated from a single ST124 clone and caused invasive Hif infections in Japan. Additional studies are needed to determine the factors that have led to the clonal expansion of virulent ST124 strains. © 2015 The Authors.

Invasive Pasteurella multocida Infections - Report of Five Cases at a Minnesota Hospital, 2014.

PubMed

Talley, P; Snippes-Vagnone, P; Smith, K

2016-09-01

During October 2014, the Minnesota Department of Health was notified of five Hospital A patients with Pasteurella multocida bacteraemia; three had died. Human soft tissue infection with P. multocida typically results from cat or dog bites or scratches. Invasive infection, defined as a P. multocida isolate from a usually sterile site, is rare. We evaluated P. multocida isolations at Hospital A, compared with other Minnesota hospitals to understand invasive infection trends. A case was defined as clinically confirmed P. multocida in a Minnesota resident during 2012-2014. All hospital laboratories were queried; Fisher's exact test was used for comparison. Medical charts were reviewed for 2014 Hospital A patients with P. multocida infections. The Minnesota clinical laboratories survey response rate was 79% (63/80). At Hospital A, proportion of P. multocida isolates from usually sterile sites increased from 0% (0/2) during 2012 to 11% (1/9) during 2013, and to 86% (5/6) during 2014. The proportion of patients with P. multocida isolated from sterile sites was 35% (6/17) at Hospital A compared with 10% (58/583) statewide during 2012-2014 combined (P < 0.05). Among 2014 Hospital A patients with invasive P. multocida infection, all five were men; median age was 70 (range: 44-78) years. Four were temporally clustered within a 33-day period; three of those had bacteraemia on admission, making hospital acquisition possible in only one. Among five bacteraemia patients, four had cirrhosis and/or skin ulcerations, and three died. The proportion of invasive P. multocida cases was substantially higher at Hospital A during 2014. No epidemiologic links between patients were found. Three had known pet exposure. Collaborative educational efforts of chronically ill pet owners by physicians and veterinarians can acknowledge the health benefits of pet ownership, while minimizing risk for serious invasive zoonotic infections, including those caused by P. multocida. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Invasive pneumococcal disease in children aged younger than 5 years in India: a surveillance study.

PubMed

Manoharan, Anand; Manchanda, Vikas; Balasubramanian, Sundaram; Lalwani, Sanjay; Modak, Meera; Bai, Sushama; Vijayan, Ajith; Shet, Anita; Nagaraj, Savitha; Karande, Sunil; Nataraj, Gita; Yewale, Vijay N; Joshi, Shrikrishna A; Iyer, Ranganathan N; Santosham, Mathuram; Kahn, Geoffrey D; Knoll, Maria Deloria

2017-03-01

Invasive pneumococcal disease continues to be a major cause of morbidity and mortality among children younger than 5 years of age in India. We aimed to provide nationally representative data for the pattern of disease due to Streptococcus pneumoniae, trends in the serotype of invasive pneumococci, and invasive pneumococci antimicrobial resistance patterns, in India. In this prospective hospital-based and retrospective laboratory-based surveillance study, we prospectively enrolled children aged younger than 5 years with suspected or proven invasive pneumococcal disease from 18 hospitals or institutional centres and retrospectively included laboratory-confirmed pneumococcal isolates from ten sentinel laboratories, together representing 11 states in India. Eligibility criteria were fever higher than 38°C without localising symptoms, clinical presentation of suspected meningitis or pneumonia, and evidence of radiographic pneumonia. We cultured blood and other normally sterile body fluids, reconfirmed and serotyped pneumococcal isolates, and established antimicrobial susceptibility using standard study protocols. Between Jan 1, 2011, and June 30, 2015, we enrolled 4377 patients. Among 361 (8%) patients with culture-proven pneumococcal disease, all clinical data were known for 226 (63%); among these patients, 132 (58%) presented with pneumonia, 78 (35%) presented with meningitis, and 16 (7%) had other clinical conditions. 131 (3%) died overall and 29 (8%) patients with invasive pneumococcal disease died. Serotypes 14 (52 [14%] of 361), 1 (49 [14%]), 5 (37 [10%]), and 19F (33 [9%]) were the most common. Penicillin non-susceptibility occurred in isolates from 29 (8%) patients, co-trimoxazole resistance occurred in 239 (66%), erythromycin resistance occurred in 132 (37%), and chloramphenicol resistance occurred in 33 (9%). We found multidrug resistance in 33 (9%) of 361 patients. The proportion of positive blood cultures, number of isolates, geographical representation, and data generated over the 4·5 years of the study are representative of data for most of India. Continued surveillance is warranted as the decision to introduce protein conjugated vaccine in India is made. GlaxoSmithKline India. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pulse Wave Velocity Predicts Response to Renal Denervation in Isolated Systolic Hypertension.

PubMed

Fengler, Karl; Rommel, Karl-Philipp; Hoellriegel, Robert; Blazek, Stephan; Besler, Christian; Desch, Steffen; Schuler, Gerhard; Linke, Axel; Lurz, Philipp

2017-05-17

Renal sympathetic denervation seems to be less effective as a treatment for hypertension in patients with isolated systolic hypertension, a condition associated with elevated central arterial stiffness. Because isolated systolic hypertension can also be caused by wave reflection or increased cardiac output, a more differentiated approach might improve patient preselection for renal sympathetic denervation. We sought to evaluate the additional predictive value of invasive pulse wave velocity for response to renal sympathetic denervation in patients with combined versus isolated systolic hypertension. Patients scheduled for renal sympathetic denervation underwent additional invasive measurement of pulse wave velocity and pulse pressure before denervation. Blood pressure was assessed via ambulatory measurement at baseline and after 3 months. In total 109 patients (40 patients with isolated systolic hypertension) were included in our analysis. After 3 months, blood pressure reduction was more pronounced among patients with combined hypertension compared with patients with isolated systolic hypertension (systolic 24-hour average 9.3±10.5 versus 5.0±11.5 mm Hg, P =0.046). However, when stratifying patients with isolated systolic hypertension by invasive pulse wave velocity, patients in the lowest tertile of pulse wave velocity had comparable blood pressure reduction (12.1±12.6 mm Hg, P =0.006) despite lower baseline blood pressure than patients with combined hypertension (systolic 24-hour average 154.8±12.5 mm Hg in combined hypertension versus 141.2±8.1, 148.4±10.9, and 150.5±12.7 mm Hg, respectively, by tertiles of pulse wave velocity, P =0.002). Extended assessment of arterial stiffness can help improve patient preselection for renal sympathetic denervation and identify a subgroup of isolated systolic hypertension patients who benefit from sympathetic modulation. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Epidemiology of invasive group A streptococcal infections in Norway 2010-2014: A retrospective cohort study.

PubMed

Naseer, U; Steinbakk, M; Blystad, H; Caugant, D A

2016-10-01

Streptococcus pyogenes or group A streptococcus (GAS) causes mild to severe infections in humans. GAS genotype emm1 is the leading cause of invasive disease worldwide. In the Nordic countries emm28 has been the dominant type since the 1980s. Recently, a resurgence of genotype emm1 was reported from Sweden. Here we present the epidemiology of invasive GAS (iGAS) infections and their association with emm-types in Norway from 2010-2014. We retrospectively collected surveillance data on antimicrobial susceptibility, multilocus sequence type and emm-type, and linked them with demographic and clinical manifestation data to calculate age and sex distributions, major emm- and sequence types and prevalence ratios (PR) on associations between emm-types and clinical manifestations. We analysed 756 iGAS cases and corresponding isolates, with overall incidence of 3.0 per 100000, median age of 59 years (range, 0-102), and male 56 %. Most frequent clinical manifestation was sepsis (49 %) followed by necrotizing fasciitis (9 %). Fifty-two different emm-types and 67 sequence types were identified, distributed into five evolutionary clusters. The most prevalent genotype was emm1 (ST28) in all years (range, 20-33 %) followed by 15 % emm28 in 2014. All isolates were susceptible to penicillin, 15 % resistant to tetracycline and <4 % resistant to erythromycin. A PR of 4.5 (95 % CI, 2.3-8.9) was calculated for emm2 and necrotizing fasciitis. All emm22 isolates were resistant to tetracycline PR 7.5 (95 % CI, 5.8-9.9). This study documented the dominance of emm1, emergence of emm89 and probable import of tetracycline resistant emm112.2 into Norway (2010-2014). Genotype fluctuations between years suggested a mutual exclusive dominance of evolutionary clades.

Response of swamp bay, Persea palustris , and redbay, P. borbonia , to Raffaelea spp. isolated from Xyleborus glabratus

Treesearch

T. J. Dreaden; A. S. Campbell; C. A. Gonzalez-Benecke; R. C. Ploetz; J. A. Smith

2016-01-01

Laurel wilt is a devastating invasive disease of members of the Lauraceae plant family. It is caused by the fungus Raffaelea lauricola, which is a nutritional symbiont of its ambrosia beetle vector, Xyleborus glabratus. In the United States, six Raffaelea spp., in addition to R. lauricola...

Occurrence of ß-lactamase genes among non-Typhi Salmonella enterica isolated from humans, food animals, and retail meats in the United States and Canada

USDA-ARS?s Scientific Manuscript database

Non-Typhi Salmonella cause over 1.7 million cases of gastroenteritis in North America each year, and food-animal products are commonly implicated in human infections. For invasive infections, antimicrobial therapy is implicated. In North America, the antimicrobial susceptibility of Salmonella is m...

Phenotypes and genotypes of erythromycin-resistant Streptococcus pyogenes strains isolated from invasive and non-invasive infections from Mexico and the USA during 1999-2010.

PubMed

Villaseñor-Sierra, Alberto; Katahira, Eva; Jaramillo-Valdivia, Abril N; Barajas-García, María de los Angeles; Bryant, Amy; Morfín-Otero, Rayo; Márquez-Díaz, Francisco; Tinoco, Juan Carlos; Sánchez-Corona, José; Stevens, Dennis L

2012-03-01

To compare the prevalence, phenotypes, and genes responsible for erythromycin resistance among Streptococcus pyogenes isolates from Mexico and the USA. Eighty-nine invasive and 378 non-invasive isolates from Mexico, plus 148 invasive, 21 non-invasive, and five unclassified isolates from the USA were studied. Susceptibilities to penicillin, erythromycin, clindamycin, ceftriaxone, and vancomycin were evaluated according to Clinical and Laboratory Standards Institute (CLSI) standards. Phenotypes of erythromycin resistance were identified by triple disk test, and screening for mefA, ermTR, and ermB genes was carried out by PCR. All isolates were susceptible to penicillin, ceftriaxone, and vancomycin. Erythromycin resistance was found in 4.9% of Mexican strains and 5.2% of USA strains. Phenotypes in Mexican strains were 95% M and 5% cMLS; in strains from the USA, phenotypes were 33.3% iMLS, 33.3% iMLS-D, and 33.3% M. Erythromycin resistance genes in strains from Mexico were mefA (95%) and ermB (5%); USA strains harbored ermTR (56%), mefA (33%), and none (11%). In Mexico, all erythromycin-resistant strains were non-invasive, whereas 89% of strains from the USA were invasive. Erythromycin resistance continues to exist at low levels in both Mexico and the USA, although the genetic mechanisms responsible differ between the two nations. These genetic differences may be related to the invasive character of the S. pyogenes isolated. Copyright © 2011 International Society for Infectious Diseases. All rights reserved.

Evaluation of MALDI-TOF-MS for the Identification of Yeast Isolates Causing Bloodstream Infection.

PubMed

Turhan, Ozge; Ozhak-Baysan, Betil; Zaragoza, Oscar; Er, Halil; Sarıtas, Zubeyde Eres; Ongut, Gozde; Ogunc, Dilara; Colak, Dilek; Cuenca-Estrella, Manuel

2017-04-01

Infections due to Candida species are major causes of morbidity and mortality in humans, causing a diverse spectrum of clinical disease ranging from superficial and mucosal infections to invasive disease. Several authors have demonstrated that mortality is closely linked to both timing of therapy and/or source control. The rapid identification of pathogenic species is helpful to start timely and effective antifungal therapy. The aim of this study was to assess the performance of the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) system for the correct and rapid identification of yeast isolates causing bloodstream infection. Between January 2014 and January 2015, a total of 117 yeast like organisms isolated from blood culture samples of 117 episodes from 102 patients who had blood stream infections were included in the study. The isolates were identified by MALDI-TOF MS. The results were compared with those obtained by the standard mycological methods and/or sequence analysis. One hundred and seventeen yeast isolates including 115 Candida spp and two non-Candida yeasts were analysed. The Biotyper correctly identified 115 (98.3%) isolates to the genus level and 102 (87.2%) isolates to the species level using the manufacturer's recommended cutoff scores. The Bruker Biotyper is a rapid, easy, inexpensive, and highly reliable system for the identification of yeast isolates. Early identification with MALDI-TOF MS would save time for determination of antifungal susceptibility and proper treatment strategy. The expansion of the database of the library by addition of less common species will improve the performance of the system.

Purification and assay of cell-invasive form of calmodulin-sensitive adenylyl cyclase from Bordetella pertussis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masure, H.R.; Donovan, M.G.; Storm, D.R.

1991-01-01

An invasive form of the CaM-sensitive adenylyl cyclase from Bordetella pertussis can be isolated from bacterial culture supernatants. This isolation is achieved through the use of QAE-Sephadex anion-exchange chromatography. It has been demonstrated that the addition of exogenous Ca{sup 2}{sup +} to the anion-exchange gradient buffers will affect elution from the column and will thereby affect the isolation of invasive adenylyl cyclase. This is probably due to a Ca2(+)-dependent interaction of the catalytic subunit with another component in the culture supernatant. Two peaks of adenylyl cyclase activity are obtained. The Pk1 adenylyl cyclase preparation is able to cause significant increasesmore » in intracellular cAMP levels in animal cells. This increase occurs rapidly and in a dose-dependent manner in both N1E-115 mouse neuroblastoma cells and human erythrocytes. The Pk2 adenylyl cyclase has catalytic activity but is not cell invasive. This material can serve, therefore, as a control to ensure that the cAMP which is measured is, indeed, intracellular. A second control is to add exogenous CaM to the Pk1 adenylyl cyclase preparation. The 45-kDa catalytic subunit-CaM complex is not cell invasive. Although the mechanism for membrane translocation of the adenylyl cyclase is unknown, there is evidence that the adenylyl cyclase enters animal cells by a mechanism distinct from receptor-mediated endocytosis. Calmodulin-sensitive adenylyl cyclase activity can be removed from preparations of the adenylyl cyclase that have been subjected to SDS-polyacrylamide gel electrophoresis. This property of the enzyme has enabled purification of the catalytic subunit to apparent homogeneity. The purified catalytic subunit from culture supernatants has a predicted molecular weight of 45,000. This polypeptide interacts directly with Ca{sup 2}{sup +} and this interaction may be important for its invasion into animal cells.« less

Population Structure of Invasive Streptococcus pneumoniae in the Netherlands in the Pre-Vaccination Era Assessed by MLVA and Capsular Sequence Typing

PubMed Central

Elberse, Karin E. M.; van de Pol, Ingrid; Witteveen, Sandra; van der Heide, Han G. J.; Schot, Corrie S.; van Dijk, Anita; van der Ende, Arie; Schouls, Leo M.

2011-01-01

The introduction of nationwide pneumococcal vaccination may lead to serotype replacement and the emergence of new variants that have expanded their genetic repertoire through recombination. To monitor alterations in the pneumococcal population structure, we have developed and utilized Capsular Sequence Typing (CST) in addition to Multiple-Locus Variable number tandem repeat Analysis (MLVA). To assess the serotype of each isolate CST was used. Based on the determination of the partial sequence of the capsular wzh gene, this method assigns a capsular type of an isolate within a single PCR reaction using multiple primersets. The genetic background of pneumococcal isolates was assessed by MLVA. MLVA and CST were used to create a snapshot of the Dutch pneumococcal population causing invasive disease before the introduction of the 7-valent pneumococcal conjugate vaccine in the Netherlands in 2006. A total of 1154 clinical isolates collected and serotyped by the Netherlands Reference Laboratory for Bacterial Meningitis were included in the snapshot. The CST was successful in discriminating most serotypes present in our collection. MLVA demonstrated that isolates belonging to some serotypes had a relatively high genetic diversity whilst other serotypes had a very homogeneous genetic background. MLVA and CST appear to be valuable tools to determine the population structure of pneumococcal isolates and are useful in monitoring the effects of pneumococcal vaccination. PMID:21637810

Group F streptococci in the pharynx: pathogens or innocent bystanders?

PubMed

Schwartz, R H; McCoy, P; Hayden, G F; Hallas, G

1986-08-01

beta-Hemolytic streptococci (BHS) of Lancefield group F were isolated in moderate to heavy growth from throat cultures taken from 46 children and adolescents with symptomatic pharyngitis. In most instances, oxygen deprivation by means of an anaerobe jar was required for these beta-hemolytic organisms to grow. In relation to a comparison group of children with throat cultures positive for group A BHS, children with group F isolates were more likely to be adolescents and less likely to have fever and cervical adenopathy. It appears that group F BHS are not a major cause of nonepidemic pharyngitis in the pediatric age group. More precise determination of how commonly these organisms cause pharyngitis will require either comparison of isolation rates of group F BHS from the throats of both sick and well children, or further elucidation of the serologic response to these organisms so as to distinguish invasive infection from asymptomatic carriage.

Glucanase and Chitinase from Some Isolates of Endophytic Fungus Trichoderma spp.

NASA Astrophysics Data System (ADS)

Prasetyawan, Sasangka; Sulistyowati, Lilik; Aulanni'am

2018-01-01

Endophytic fungi are those fungi that are able to grow in plant tissue without causing symptoms of disease. It is thought that these fungi may confer on the host plants degree of resistance to parasitic invasion. Endophytic fungi have been isolated from stem tissue and these fungi are known to be antagonistic to pathogenic fungi. These endophytes produce chitinase and β-1,3-glucanase enzymes. Based on the fact that chitin and β-1,3-glucan are the main skeletal polysaccharides of the cell walls of fungal patogen. The aim of this research is to do potential test on some of isolates of Trichoderma’s endophytic (L-1, L-2, Is-1, Is-2 and Is-7) in the chitinase and β-1,3-glucanase activity in effort to determine endophytic which be chossen to be gene resource for the next research. The gene will be transformed to citrus plant japanese citroen in effort to make citrus plant transgenic resistance to phytopatogenic invasion. The result of this research is endofit namely L-1 is the most potential endophytic fungi with chitinase activities is 4,8 10-2 Unit and glucanase 24,2. 1012 Unit. The addition of chitin and cell wall of phytophtora causes chitinase activity significantly increase, and also addition of laminarin and cell wall of phytophtora makes glucanase activity increase.

Infective endocarditis caused by multidrug-resistant Streptococcus mitis in a combined immunocompromised patient: an autopsy case report.

PubMed

Matsui, Natsuko; Ito, Makoto; Kuramae, Hitoshi; Inukai, Tomomi; Sakai, Akiyoshi; Okugawa, Masaru

2013-04-01

An autopsy case of infective endocarditis caused by multidrug-resistant Streptococcus mitis was described in a patient with a combination of factors that compromised immune status, including autoimmune hemolytic anemia, post-splenectomy state, prolonged steroid treatment, and IgA deficiency. The isolated S. mitis strain from blood culture was broadly resistant to penicillin, cephalosporins, carbapenem, macrolides, and fluoroquinolone. Recurrent episodes of bacterial infections and therapeutic use of several antibiotics may underlie the development of multidrug resistance for S. mitis. Because clinically isolated S. mitis strains from chronically immunocompromised patients have become resistant to a wide spectrum of antibiotics, appropriate antibiotic regimens should be selected when treating invasive S. mitis infections in these compromised patients.

Changing trends in serotypes of S. pneumoniae isolates causing invasive and non-invasive diseases in unvaccinated population in Mexico (2000-2014).

PubMed

Carnalla-Barajas, María Noemí; Soto-Noguerón, Araceli; Sánchez-Alemán, Miguel Angel; Solórzano-Santos, Fortino; Velazquez-Meza, María Elena; Echániz-Aviles, Gabriela

2017-05-01

Introduction of pneumococcal conjugate vaccines (PCV) targeted against a limited number of serotypes substantially decreased invasive (IPD) and non-invasive pneumococcal diseases (NIPD) but it was accompanied by non-vaccine type replacement disease. After 9 years of introduction of PCV in Mexico, we analyze the evidence of the indirect effects on IPD and NIPD serotype distribution among groups not targeted to receive the vaccine. From January 2000 to December 2014, pneumococcal strains isolated from IPD and NIPD cases from patients ≥5 years of age from participant hospitals of the SIREVA II (Sistema Regional de Vacunas) network were serotyped. A regression analysis was performed considering year and proportion of serotypes included in the different vaccine formulations (PCV7, PCV10 and PCV13). The slope was obtained for each regression line and their correspondent p-value. The proportion of each serotype in the pre-PCV7 and post-PCV7 periods was evaluated by χ2 test. From a total of 1147 pneumococcal strains recovered, 570 corresponded to the pre-PCV7 and 577 to the post-PCV7 periods. The proportion of vaccine serotypes included in the three PCV formulations decreased by 2.4, 2.6 and 1.3%, respectively per year during the study period. A significant increase of serotype 19A was observed in the post-vaccine period in all age groups. A percentage of annual decline of serotypes causing IPD and NIPD included in PCV was detected among groups not targeted to receive the vaccine, probably due to herd effect. Considering pneumococcal serotype distribution is a dynamic process, we highlight the importance of surveillance programs. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Miscellaneous fungal diseases

USGS Publications Warehouse

Friend, M.

1999-01-01

As for other types of disease, fungal infections probably are more common causes of disease in wild birds than is currently recognized. Also, the similarity in gross lesions produced by some fungi mask the detection of less common fungi as disease agents. Numerous types of disease-causing fungi in addition to Aspergillus fumigatus and Candida albicans have been isolated from birds; most isolations have been from poultry and wild birds being maintained in captivity. Enhanced disease surveillance that is often associated with privately owned birds and greater opportunity to detect disease in confined birds are reasons for these findings rather than any known differences in the occurrence of fungal diseases in free-ranging and captive birds. Many of the reported infections appear to have been opportunistic invasions by the fungi involved. The important points are that many fungi are capable of causing disease in birds but their collective impacts do not rival A. fumigatus as a single cause of disease in wild birds. Nevertheless, it is important to be aware of the diversity of pathogenic or disease causing fungi.

Epidemiology of invasive Streptococcus pyogenes infections in France in 2007.

PubMed

Lepoutre, A; Doloy, A; Bidet, P; Leblond, A; Perrocheau, A; Bingen, E; Trieu-Cuot, P; Bouvet, A; Poyart, C; Lévy-Bruhl, D

2011-12-01

Invasive group A streptococcal (GAS) infections cause significant morbidity and mortality. A national survey was initiated to assess the burden of invasive GAS infections in France, describe their clinical characteristics, and assess the molecular characteristics of GAS strains responsible for these infections. The survey was conducted in 194 hospitals, accounting for 51% of acute care hospital admissions in France. Clinical data, predisposing factors, and demographic data were obtained, and all GAS isolates were emm sequence typed. We identified 664 cases of invasive GAS infections, with an annual incidence of 3.1 per 100,000 population. The case-fatality ratio was 14% and rose to 43% in the case of streptococcal toxic shock syndrome. Bacteremia without identified focus (22%) and skin/soft tissue infections (30%) were the most frequent clinical presentations. Necrotizing fasciitis was frequent in adults (18%) and uncommon in children (3%). The 3 predominant emm types were emm1, emm89, and emm28, accounting for 33%, 16%, and 10% of GAS isolates, respectively. The emm1 type was associated with fatal outcomes and was more frequent in children than in adults. Six clusters of cases were identified, with each cluster involving 2 invasive cases due to GAS strains which shared identical GAS emm sequence types. Four clusters of cases involved eight postpartum infections, one family cluster involved a mother and child, and one cluster involved two patients in a nursing home. Invasive GAS infection is one of the most severe bacterial diseases in France, particularly in persons aged ≥ 50 years or when associated with toxic shock syndrome.

Epidemiology of Invasive Streptococcus pyogenes Infections in France in 2007 ▿

PubMed Central

Lepoutre, A.; Doloy, A.; Bidet, P.; Leblond, A.; Perrocheau, A.; Bingen, E.; Trieu-Cuot, P.; Bouvet, A.; Poyart, C.; Lévy-Bruhl, D.

2011-01-01

Invasive group A streptococcal (GAS) infections cause significant morbidity and mortality. A national survey was initiated to assess the burden of invasive GAS infections in France, describe their clinical characteristics, and assess the molecular characteristics of GAS strains responsible for these infections. The survey was conducted in 194 hospitals, accounting for 51% of acute care hospital admissions in France. Clinical data, predisposing factors, and demographic data were obtained, and all GAS isolates were emm sequence typed. We identified 664 cases of invasive GAS infections, with an annual incidence of 3.1 per 100,000 population. The case-fatality ratio was 14% and rose to 43% in the case of streptococcal toxic shock syndrome. Bacteremia without identified focus (22%) and skin/soft tissue infections (30%) were the most frequent clinical presentations. Necrotizing fasciitis was frequent in adults (18%) and uncommon in children (3%). The 3 predominant emm types were emm1, emm89, and emm28, accounting for 33%, 16%, and 10% of GAS isolates, respectively. The emm1 type was associated with fatal outcomes and was more frequent in children than in adults. Six clusters of cases were identified, with each cluster involving 2 invasive cases due to GAS strains which shared identical GAS emm sequence types. Four clusters of cases involved eight postpartum infections, one family cluster involved a mother and child, and one cluster involved two patients in a nursing home. Invasive GAS infection is one of the most severe bacterial diseases in France, particularly in persons aged ≥50 years or when associated with toxic shock syndrome. PMID:21976764

A monoclonal antibody for distinction of invasive and noninvasive clinical isolates of Entamoeba histolytica.

PubMed Central

Gonzalez-Ruiz, A; Haque, R; Rehman, T; Aguirre, A; Jaramillo, C; Castañon, G; Hall, A; Guhl, F; Ruiz-Palacios, G; Warhurst, D C

1992-01-01

Approximately 10% of the world population is infected with Entamoeba histolytica, but only 10% of the carriers develop symptomatic amebiasis. This discrepancy could be explained by the genotypic differences between the morphologically indistinguishable invasive and noninvasive strains of E. histolytica currently identified by zymodeme analysis, a technique that is unsuitable for routine diagnostic laboratories. Here we report the production of a monoclonal antibody against E. histolytica and its use in an immunofluorescence assay to identify invasive isolates cultured from stool samples of infected patients in several regions where amebiasis is endemic: Bangladesh, Colombia, and Mexico. After testing a total of 88 E. histolytica isolates, the correlation between zymodeme characterization and the immunofluorescence assay with the invasive isolate-specific monoclonal antibody was 100%. The epitope detected by the invasive isolate-specific monoclonal antibody resides in a previously undescribed internal protein with molecular masses of 84 and 81 kDa in axenic and polyxenic E. histolytica strains, respectively. Images PMID:1452651

Dominance of multidrug-resistant Denmark(14)-32 (ST230) clone among Streptococcus pneumoniae serotype 19A isolates causing pneumococcal disease in Bulgaria from 1992 to 2013.

PubMed

Setchanova, Lena Petrova; Alexandrova, Alexandra; Dacheva, Daniela; Mitov, Ivan; Kaneva, Radka; Mitev, Vanio

2015-02-01

A pneumococcal conjugate vaccine (PCV10) was introduced in Bulgarian national immunization program since April 2010. Clonal composition based on pulsed-field gel electrophoresis and multilocus sequence typing genotyping of 52 serotype 19A Streptococcus pneumoniae isolates was analyzed. These were invasive and respiratory isolates collected between 1992 and 2013 from both children (78.8% <5 years) and adults with pneumococcal infections. Multidrug resistance was found in 82.7% of all 19A isolates. The most prevalent genotype (63.5%) among serotype 19A pneumococcal strains was the multidrug-resistant clonal complex CC230, which is a capsular switched variant of the Denmark(14)-32 (ST230) global clone. The most frequent sequence type (ST) was ST230 (48.1%) and together with four other closely related STs (15.4%), belonging to ST1611, ST276, ST7466, and ST2013, which were single- and double-locus variants; they were included in the main CC230. The disappearance of highly drug-resistant ST663 clone and emergence of new clones as CC320 and CC199 was also observed among the rest 19A isolates. A comparison of clonal composition between invasive and noninvasive isolates did not show a great genetic diversity among both kinds of isolates. Continuous surveillance of serotype 19A population following the introduction of PCV10 is essential to evaluate the impact of the vaccine on the epidemiology of this serotype.

Molecular epidemiology of Klebsiella pneumoniae invasive infections over a decade at Kilifi County Hospital in Kenya.

PubMed

Henson, Sonal P; Boinett, Christine J; Ellington, Matthew J; Kagia, Ngure; Mwarumba, Salim; Nyongesa, Sammy; Mturi, Neema; Kariuki, Samuel; Scott, J Anthony G; Thomson, Nicholas R; Morpeth, Susan C

2017-10-01

Multidrug resistant (MDR) Klebsiella pneumoniae is a common cause of nosocomial infections worldwide. Recent years have seen an explosion of resistance to extended-spectrum β-lactamases (ESBLs) and emergence of carbapenem resistance. Here, we examine 198 invasive K. pneumoniae isolates collected from over a decade in Kilifi County Hospital (KCH) in Kenya. We observe a significant increase in MDR K. pneumoniae isolates, particularly to third generation cephalosporins conferred by ESBLs. Using whole-genome sequences, we describe the population structure and the distribution of antimicrobial resistance genes within it. More than half of the isolates examined in this study were ESBL-positive, encoding CTX-M-15, SHV-2, SHV-12 and SHV-27, and 79% were MDR conferring resistance to at least three antimicrobial classes. Although no isolates in our dataset were found to be resistant to carbapenems we did find a plasmid with the genetic architecture of a known New Delhi metallo-β-lactamase-1 (NDM)-carrying plasmid in 25 isolates. In the absence of carbapenem use in KCH and because of the instability of the NDM-1 gene in the plasmid, the NDM-1 gene has been lost in these isolates. Our data suggests that isolates that encode NDM-1 could be present in the population; should carbapenems be introduced as treatment in public hospitals in Kenya, resistance is likely to ensue rapidly. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Molecular Tools for the Detection and Deduction of Azole Antifungal Drug Resistance Phenotypes in Aspergillus Species.

PubMed

Dudakova, Anna; Spiess, Birgit; Tangwattanachuleeporn, Marut; Sasse, Christoph; Buchheidt, Dieter; Weig, Michael; Groß, Uwe; Bader, Oliver

2017-10-01

The incidence of azole resistance in Aspergillus species has increased over the past years, most importantly for Aspergillus fumigatus . This is partially attributable to the global spread of only a few resistance alleles through the environment. Secondary resistance is a significant clinical concern, as invasive aspergillosis with drug-susceptible strains is already difficult to treat, and exclusion of azole-based antifungals from prophylaxis or first-line treatment of invasive aspergillosis in high-risk patients would dramatically limit drug choices, thus increasing mortality rates for immunocompromised patients. Management options for invasive aspergillosis caused by azole-resistant A. fumigatus strains were recently reevaluated by an international expert panel, which concluded that drug resistance testing of cultured isolates is highly indicated when antifungal therapy is intended. In geographical regions with a high environmental prevalence of azole-resistant strains, initial therapy should be guided by such analyses. More environmental and clinical screening studies are therefore needed to generate the local epidemiologic data if such measures are to be implemented on a sound basis. Here we propose a first workflow for evaluating isolates from screening studies, and we compile the MIC values correlating with individual amino acid substitutions in the products of cyp51 genes for interpretation of DNA sequencing data, especially in the absence of cultured isolates. Copyright © 2017 American Society for Microbiology.

Serotypes and Clonal Diversity of Streptococcus pneumoniae Causing Invasive Disease in the Era of PCV13 in Catalonia, Spain

PubMed Central

del Amo, Eva; Esteva, Cristina; Hernandez-Bou, Susanna; Galles, Carmen; Navarro, Marian; Sauca, Goretti; Diaz, Alvaro; Gassiot, Paula; Marti, Carmina; Larrosa, Nieves; Ciruela, Pilar; Jane, Mireia; Sá-Leão, Raquel; Muñoz-Almagro, Carmen

2016-01-01

The aim of this study was to study the serotypes and clonal diversity of pneumococci causing invasive pneumococcal disease in Catalonia, Spain, in the era of 13-valent pneumococcal conjugate vaccine (PCV13). In our region, this vaccine is only available in the private market and it is estimated a PCV13 vaccine coverage around 55% in children. A total of 1551 pneumococcal invasive isolates received between 2010 and 2013 in the Molecular Microbiology Department at Hospital Sant Joan de Déu, Barcelona, were included. Fifty-two serotypes and 249 clonal types—defined by MLST—were identified. The most common serotypes were serotype 1 (n = 182; 11.7%), 3 (n = 145; 9.3%), 19A (n = 137; 8.8%) and 7F (n = 122; 7.9%). Serotype 14 was the third most frequent serotype in children < 2 years (15 of 159 isolates). PCV7 serotypes maintained their proportion along the period of study, 16.6% in 2010 to 13.4% in 2013, whereas there was a significant proportional decrease in PCV13 serotypes, 65.3% in 2010 to 48.9% in 2013 (p<0.01). This decrease was mainly attributable to serotypes 19A and 7F. Serotype 12F achieved the third position in 2013 (n = 22, 6.4%). The most frequent clonal types found were ST306 (n = 154, 9.9%), ST191 (n = 111, 7.2%), ST989 (n = 85, 5.5%) and ST180 (n = 80, 5.2%). Despite their decrease, PCV13 serotypes continue to be a major cause of disease in Spain. These results emphasize the need for complete PCV13 vaccination. PMID:26953887

Carriage and invasive isolates of Streptococcus pneumoniae in Caracas, Venezuela: the relative invasiveness of serotypes and vaccine coverage.

PubMed

Rivera-Olivero, I A; del Nogal, B; Sisco, M C; Bogaert, D; Hermans, P W M; de Waard, J H

2011-12-01

The introduction of a pneumococcal conjugate vaccine in Venezuela needs previous studies to assess vaccine efficiency. We conducted a survey of nasopharyngeal pneumococcal carriage in urban children in Caracas and studied the distribution of serotypes. We compared these data with survey data available for invasive strains isolated in the same area and in the same time period. An overall pneumococcal carriage rate of 27% was observed. The most predominant capsular serotypes among carriage isolates were 6B (29%), 19A (13.8%), 23F (10%), 14 (8.3%), 6A (8.3%) and 15B/C (3.3%) and among invasive isolates 6B (25%), 14 (15%), and 19A, 6A, 7F, and 18 (7.5% each). The serotypes/groups 1, 5, 7F and 18, jointly covering 30% of the invasive strains, represented less than 0.7% of the carrier strains. The theoretical coverage of the pneumococcal conjugate vaccine PCV13 for carriage and invasive strains was calculated to be 74% and 90%, respectively. Our study demonstrates important differences for the serotype distribution in disease and carriage isolates and provides a key baseline for future studies addressing the prevalence and replacement of invasive and carriage serotypes after the introduction of the PCV 13 vaccine in Venezuela in the year 2010.

Streptococcus agalactiae Causing Neonatal Infections in Portugal (2005-2015): Diversification and Emergence of a CC17/PI-2b Multidrug Resistant Sublineage.

PubMed

Martins, Elisabete R; Pedroso-Roussado, Cristiano; Melo-Cristino, José; Ramirez, Mário

2017-01-01

The molecular characterization of 218 GBS isolates recovered from neonatal invasive infections in Portugal in 2005-2015 revealed the existence of a small number of genetically distinct lineages that were present over a significant time-span. Serotypes III and Ia were dominant in the population, together accounting for >80% of the isolates. Clonal complex 17 included 50% of all isolates, highlighting the importance of the hypervirulent genetic lineage represented by serotype III ST17/ rib /PI-1+PI-2b. Serotype Ia was represented mainly by ST23, previously reported as dominant among invasive disease in non-pregnant adults in Portugal, but also by ST24, showing an increased frequency among late-onset disease. Overall erythromycin resistance was 16%, increasing during the study period ( p < 0.001). Macrolide resistance was overrepresented among CC1 and CC19 isolates ( p < 0.001 and p = 0.008, respectively). While representatives of the hypervirulent CC17 lineage were mostly susceptible to macrolides, we identified for the first time in Europe a recently emerging sublineage characterized by the loss of PI-1 (CC17/PI-2b), simultaneously resistant to macrolides, lincosamides, and tetracycline, also exhibiting high-level resistance to streptomycin and kanamycin. The stability and dominance of CC17 among neonatal invasive infections in the past decades indicates that it is extremely well adapted to its niche; however emerging resistance in this genetic background may have significant implications for the prevention and management of GBS disease.

Meningitis due to Haemophilus influenzae type f.

PubMed

Cardoso, Marta Pessoa; Pasternak, Jacyr; Giglio, Alfredo Elias; Casagrande, Rejane Rimazza Dalberto; Troster, Eduardo Juan

2013-12-01

With the decline in the rate of infections caused by Haemophilus influenzae serotype b since the widespread vaccination, non-b serotypes should be considered as potential pathogenic agents in children with invasive disease younger than 5 years old. We report the case of an immunocompetent 1-year-old boy with Haemophilus influenzae type f meningitis. The agent was identified in cerebrospinal fluid and blood cultures. Serotyping was performed by tests using polyclonal sera and confirmed by polymerase chain reaction. All Haemophilus influenzae isolates associated with invasive disease should be serotyped and notified as a way to evaluate the changes and trends in serotype distribution of this disease.

Methods to isolate extracellular vesicles for diagnosis

NASA Astrophysics Data System (ADS)

Kang, Hyejin; Kim, Jiyoon; Park, Jaesung

2017-12-01

Extracellular vesicles (EVs) are small membrane-bound bodies that are released into extracellular space by diverse cells, and are found in body fluids like blood, urine and saliva. EVs contain RNA, DNA and proteins, which can be biomarkers for diagnosis. EVs can be obtained by minimally-invasive biopsy, so they are useful in disease diagnosis. High yield and purity contribute to precise diagnosis of disease, but damaged EVs and impurities can cause confu sed results. However, EV isolation methods have different yields and purities. Furthermore, the isolation method that is most suitable to maximize EV recovery efficiency depends on the experimental conditions. This review focuses on merits and demerits of several types of EV isolation methods, and provides examples of how to diagnose disease by exploiting information obtained by analysis of EVs.

[The effect of hydrophobicity of group A beta-hemolytic streptococcus in the process of adherence and biofilm production ].

PubMed

2014-01-01

Bacterial cell hydrophobicity and adherence to a substrate are one of the most important factors in biofilm formation. Group A streptococcus is an unstable and low biofilm productor. Importance of biofilm production in streptococcal pathogenesis is still unknown. The aim of this study was to determine the impact of hydrophobicity and adherence on the biofilm production of group A streptococcal invasive and noninvasive isolates, and also to evaluate the stability of biofilm production in time function. Adherence, hydrophobicity and biofilm production were investigated in a total of 172 isolates divided into three groups: noninvasive, low invasive and highly invasive. Adher- ence to uncoated and laminin-coated microtiter plates and biofilm production after 12, 24 and 48 hours of incubation was determined using the method described by Stepanović et al. Hydrophobicity was measured using the MATH test by Rosenberg and SAT test by Lindhal. Correlation between adherence and biofilm produc- tion was detected in the group of noninvasive isolates. These isolates were stable biofilm productors during all three time periods of biofilm production. In the groups of invasive and noninvasive isolates no statistical correlation was detected among the analysed variables. The invasive isolates were un- stable biofilm productors. Noninvasive isolates were stable biofilm producers; as detected, they showed a direct correlation between adherence and biofilm production, and a negative impact of hydrophobicity on the biofilm production. Invasive isolates were unstable biofilm productors; it was observed that there was no correlation between adherence and hydrophobicity with biofilm production.

Hemolysin as a Virulence Factor for Systemic Infection with Isolates of Mycobacterium avium Complex

PubMed Central

Maslow, Joel N.; Dawson, David; Carlin, Elizabeth A.; Holland, Steven M.

1999-01-01

Isolates of the Mycobacterium avium complex were examined for hemolysin expression. Only invasive isolates of M. avium were observed to be hemolytic (P < 0.001), with activity the greatest for isolates of serovars 4 and 8. Thus, M. avium hemolysin appears to represent a virulence factor necessary for invasive disease. PMID:9889239

Thinking beyond the Common Candida Species: Need for Species-Level Identification of Candida Due to the Emergence of Multidrug-Resistant Candida auris.

PubMed

Lockhart, Shawn R; Jackson, Brendan R; Vallabhaneni, Snigdha; Ostrosky-Zeichner, Luis; Pappas, Peter G; Chiller, Tom

2017-12-01

Candida species are one of the leading causes of nosocomial infections. Because much of the treatment for Candida infections is empirical, some institutions do not identify Candida to species level. With the worldwide emergence of the multidrug-resistant species Candida auris , identification of Candida to species level has new clinical relevance. Species should be identified for invasive candidiasis isolates, and species-level identification can be considered for selected noninvasive isolates to improve detection of C. auris . Copyright © 2017 American Society for Microbiology.

Occurrence, Persistence, and Virulence Potential of Listeria ivanovii in Foods and Food Processing Environments in the Republic of Ireland

PubMed Central

Morgan, Ciara A.; Hill, Colin; Gahan, Cormac G. M.; Jordan, Kieran

2015-01-01

The aim of this study was to assess the occurrence of L. ivanovii in foods and food processing environments in Ireland, to track persistence, and to characterize the disease causing potential of the isolated strains. A total of 2,006 samples (432 food samples and 1,574 environmental swabs) were collected between March 2013 and March 2014 from 48 food business operators (FBOs) belonging to different production sectors (dairy, fish, meat, and fresh-cut vegetable). Six of the forty-eight FBOs had samples positive for L. ivanovii on at least one sampling occasion. L. ivanovii was present in fifteen samples (fourteen environmental samples and one food sample). All but one of those positive samples derived from the dairy sector, where L. ivanovii prevalence was 1.7%. Six distinguishable pulsotypes were obtained by PFGE analysis, with one pulsotype being persistent in the environment of a dairy food business. Sequence analysis of the sigB gene showed that fourteen isolates belonged to L. ivanovii subsp. londoniensis, while only one isolate was L. ivanovii subsp. ivanovii. Cell invasion assays demonstrated that the majority of L. ivanovii strains were comparable to L. monocytogenes EGDe in their ability to invade CACO-2 epithelial cells whilst four isolates had significantly higher invasion efficiencies. PMID:26543856

A viable circulating tumor cell isolation device with high retrieval efficiency using a reversibly deformable membrane barrier

NASA Astrophysics Data System (ADS)

Kim, Yoonji; Bu, Jiyoon; Cho, Young-Ho; Son, Il Tae; Kang, Sung-Bum

2017-02-01

Circulating tumor cells (CTCs) contain prognostic information of the tumor, since they shed from the primary tumor and invade into the bloodstream. Therefore, the viable isolation is necessary for a consequent analysis of CTCs. Here, we present a device for the viable isolation and efficient retrieval of CTCs using slanted slot filters, formed by a reversibly deformable membrane barrier. Conventional filters have difficulties in retrieving captured cells, since they easily clog the slots. Moreover, large stress concentration at the sharp edges of squared slots, causes cell lysis. In contrast, the present device shows over 94% of high retrieval efficiency, since the slots can be opened simply by relieving the pressure. Furthermore, the inflated membrane barrier naturally forms the slanted slots, thus reducing the cell damage. By using cancer cell lines, we verified that the present device successfully isolate targeted cells, even at an extremely low concentrations (~10 cells/0.1 ml). In the clinical study, 85.7% of patients initially showed CTC positive while the numbers generally decreased after the surgery. We have also proved that the number of CTCs were highly correlated with tumour invasiveness. Therefore, the present device has potential for use in cancer diagnosis, surgical validation, and invasiveness analysis.

A Decade of Invasive Meningococcal Disease Surveillance in Poland

PubMed Central

Skoczyńska, Anna; Waśko, Izabela; Kuch, Alicja; Kadłubowski, Marcin; Gołębiewska, Agnieszka; Foryś, Małgorzata; Markowska, Marlena; Ronkiewicz, Patrycja; Wasiak, Katarzyna; Kozińska, Aleksandra; Matynia, Bożena; Hryniewicz, Waleria

2013-01-01

Background Neisseria meningitidis is a leading etiologic agent of severe invasive disease. The objective of the study was to characterise invasive meningococcal disease (IMD) epidemiology in Poland during the last decade, based on laboratory confirmed cases. Methods The study encompassed all invasive meningococci collected between 2002 and 2011 in the National Reference Centre for Bacterial Meningitis. The isolates were re-identified and characterised by susceptibility testing, MLST analysis, porA and fetA sequencing. A PCR technique was used for meningococcal identification directly from clinical materials. Results In the period studied, 1936 cases of IMD were confirmed, including 75.6% identified by culture. Seven IMD outbreaks, affecting mostly adolescents, were reported; all were caused by serogroup C meningococci of ST-11. The highest incidence was observed among children under one year of age (15.71/100,000 in 2011). The general case fatality rate in the years 2010–2011 was 10.0%. Meningococci of serogroup B, C, Y and W-135 were responsible for 48.8%, 36.6%, 1.2% and 1.2% of cases, respectively. All isolates were susceptible to third generation cephalosporins, chloramphenicol, ciprofloxacin, and 84.2% were susceptible to penicillin. MLST analysis (2009–2011) revealed that among serogroup B isolates the most represented were clonal complexes (CC) ST-32CC, ST-18CC, ST-41/44CC, ST-213CC and ST-269CC, and among serogroup C: ST-103CC, ST-41/44CC and ST-11CC. Conclusions The detection of IMD in Poland has changed over time, but observed increase in the incidence of the disease was mostly attributed to changes in the surveillance system including an expanded case definition and inclusion of data from non-culture diagnostics. PMID:23977184

Aspergillus pragensis sp. nov. discovered during molecular reidentification of clinical isolates belonging to Aspergillus section Candidi.

PubMed

Hubka, Vit; Lyskova, Pavlina; Frisvad, Jens C; Peterson, Stephen W; Skorepova, Magdalena; Kolarik, Miroslav

2014-08-01

The identity of nine clinical isolates recovered from Czech patients and presumptively identified as Aspergillus sp. section Candidi based on colony morphology was revised using sequences of β-tubulin, calmodulin gene sequence, and internal transcribed spacer rDNA. Six isolates were from suspected and proven onychomycosis, one from otitis externa, and two associated with probable invasive aspergillosis. The results showed that one Aspergillus candidus isolate was the cause of otitis externa, and both isolates obtained from sputa of patients with probable invasive aspergillosis were reidentified as A. carneus (sect. Terrei) and A. flavus (sect. Flavi). Three isolates from nail scrapings were identified as A. tritici, a verified agent of nondermatophyte onychomycosis. One isolate from toenail was determined to be A. candidus and the two isolates belonged to a hitherto undescribed species, Aspergillus pragensis sp. nov. This species is well supported by phylogenetic analysis based on β-tubulin and calmodulin gene and is distinguishable from other members of sect. Candidi by red-brown reverse on malt extract agar, slow growth on Czapek-Dox agar and inability to grow at 37°C. A secondary metabolite analysis was also provided with comparison of metabolite spectrum to other species. Section Candidi now encompasses five species for which a dichotomous key based on colony characteristics is provided. All clinical isolates were tested for susceptibilities to selected antifungal agents using the Etest and disc diffusion method. Overall sect. Candidi members are highly susceptible to common antifungals. © The Author 2014. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Streptococcal pyrogenic exotoxin G gene in blood and pharyngeal isolates of Streptococcus dysgalactiae subspecies equisimilis has a limited role in pathogenesis.

PubMed

Korem, Maya; Hidalgo-Grass, Carlos; Michael-Gayego, Ayelet; Nir-Paz, Ran; Salameh, Shaden; Moses, Allon E

2014-08-01

Streptococcus dysgalactiae subspecies equisimilis (SE) causes human infections that clinically resemble infections due to Streptococcus pyogenes (SP). SE expresses several virulence determinants initially identified in SP, including genes encoding streptococcal pyrogenic exotoxins. SE isolates from patients with toxic shock syndrome were found to harbor a gene designated spegg, which is similar to the SP pyrogenic exotoxin-G gene, termed speG. Other streptococcal pyrogenic exotoxins known to exist in SP were not detected. To determine the prevalence of the superantigen gene, spegg, we examined 65 invasive SE from patients presenting from 1989 to 2008 with bacteremia secondary to a variety of illnesses including two patients who fulfilled the criteria for toxic shock syndrome, in comparison with 46 noninvasive pharyngeal isolates. All isolates were tested for the presence of spegg by polymerase chain reaction. Forty-four of the 65 blood isolates were also characterized by emm typing. spegg was identified in 49.2% and 69.5% of the blood and pharyngeal isolates, respectively. emm typing revealed the presence of 13 distinct types. There was no association between clinical presentation and the presence of spegg. We found an association between the presence of spegg and the emm type (p < 0.001). The emm types stG485 and stG840 were more frequent among spegg positive isolates, and stG4222, stG6, and stG166b were associated with spegg negative isolates. We found a high prevalence of spegg in invasive and noninvasive SE isolates, associated with specific emm types. Our finding suggests that this gene does not have a role in the pathogenesis of bacteremia. Copyright © 2012. Published by Elsevier B.V.

A severe Salmonella enterica serotype Paratyphi B infection in a child related to a pet turtle, Trachemys scripta elegans.

PubMed

Nagano, Noriyuki; Oana, Shinji; Nagano, Yukiko; Arakawa, Yoshichika

2006-04-01

Our report highlights a case of severe childhood salmonellosis related to a pet turtle, a red-eared slider (Trachemys scripta elegans). A 6-year-old girl had gastroenteritis complicated with sepsis caused by serotype Paratyphi B, which shared the same pulsed-field gel electrophoresis profiles with the organism isolated from a pet turtle. Based on our literature survey on childhood invasive salmonellosis acquired from reptiles, this case is the first documented reptile-associated salmonellosis including sepsis caused by this serotype.

Changing epidemiology of group B streptococcal infections among adults in Iceland: 1975-2014.

PubMed

Björnsdóttir, E S; Martins, E R; Erlendsdóttir, H; Haraldsson, G; Melo-Cristino, J; Kristinsson, K G; Ramirez, M

2016-04-01

We studied the bacterial characteristics and incidence of invasive infections caused by group B streptococci (GBS) in adults in Iceland in 1975-2014. A total of 145 isolates were characterized by serotyping, antimicrobial susceptibility, multilocus sequence typing and surface protein gene profiling. Disease incidence increased during the studied period (p <0.001), reaching 2.17 cases/100 000 person-years in 2013-14. Overall, serotype Ia was the most frequently found (23%), but serotypes Ib, II, III and V showed similar prevalence (14%-17%). Although there were notable changes in the proportion of most serotypes during the study period, only the decline of serotype III was statistically supported (p = 0.003) and was reflected in a decrease of clonal complexes CC17 and CC19 that included most serotype III isolates (p <0.04). On the other hand, the increase in frequency of CC1 was caused by two lineages expressing distinct serotypes: ST1/V/alp3 and ST196/IV/eps. Underlying the relative stability of serotype Ia were major changes in the lineages expressing this serotype, with an increase in the relative importance of CC23, including both ST23/Ia/eps and ST24/Ia/bca lineages, and a decrease in CC7. Nine cases of invasive GBS disease were caused by ST7, of possible zoonotic origin. All isolates were susceptible to penicillin. Rates of erythromycin and clindamycin resistance were 8.3% and 9.7%, respectively. An over-representation of resistance solely to clindamycin was associated with the unusual lsaC gene and serotype III ST19/rib lineage (p <0.001). Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

A Multischool Outbreak Due to Salmonella enterica serovar Napoli Associated with Elevated Rates of Hospitalizations and Bacteremia, Milan, Italy, 2014.

PubMed

Huedo, Pol; Gori, Maria; Amato, Ettore; Bianchi, Roberta; Valerio, Edgardo; Magnoli, Luigi; Pontello, Mirella

2016-08-01

A multischool outbreak of salmonellosis caused by Salmonella enterica serovar Napoli was investigated in the province of Milan from October to November 2014, following an increase in school absenteeism coinciding with two positive cases. Epidemiological studies detected 47 cases in four primary schools: 46 children and 1 adult woman (51.4% males and 48.6% females, median age 8.9). From these, 14 cases (29.8%) were severe and resulted in hospitalization, including 6 children (12.8%) who developed an invasive salmonellosis. The epidemic curve revealed an abnormally long incubation period, peaking 1 week after the first confirmed case. Twenty-five available isolates were typed by pulsed-field gel electrophoresis showing an identical pattern. The isolate belongs to ST474, an ST composed exclusively of Salmonella Napoli human strains isolated in France and Italy. Antibiotic resistance analysis showed resistance to aminoglycosides, correlating with the presence of the aminoglycoside resistance gene aadA25 in its genome. Trace-back investigations strongly suggested contaminated ham as the most likely food vehicle, which was delivered by a common food center on 21 October. Nevertheless, this ingredient could not be retrospectively investigated since it was no longer available at the repository. This represents the largest Salmonella Napoli outbreak ever reported in Italy and provides a unique scenario for studying the outcome of salmonellosis caused by this emerging and potentially invasive nontyphoidal serotype.

Characteristics of invasion-reduced hilA gene mutant of Salmonella Enteritidis in vitro and in vivo.

PubMed

Lv, Shuang; Si, Wei; Yu, Shenye; Li, Zhaoli; Wang, Xiumei; Chen, Liping; Zhang, Wanjiang; Liu, Siguo

2015-08-01

Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) is a facultative intracellular pathogen that causes huge losses in poultry industry and also food poisoning in humans due to its being a food-borne pathogen. Functions of Invasion-related genes need to be explored, as invasion is a key step for Salmonella infection. In this study, a transposon mutant library of Salmonella Enteritidis isolate SM6 was constructed and screened for the invasion-related genes via incubation with Caco-2 cells. Three stably attenuated mutants were identified for significantly reduced invasion with insertions all in hilA (hyperinvasive locus A) gene. We constructed and evaluated the hilA deletion mutant in vivo and in vitro. SM6△hilA showed significantly reduced ability to invade Caco-2 cells and decreased pathogenicity in chicks. However, the bacterial load and pathological damage in the cecum were significantly higher than those in the SM6 in vivo. Present results provide new evidences for pathogenicity research on Salmonella Enteritidis. Copyright © 2015 Elsevier B.V. All rights reserved.

A variable region within the genome of Streptococcus pneumoniae contributes to strain-strain variation in virulence.

PubMed

Harvey, Richard M; Stroeher, Uwe H; Ogunniyi, Abiodun D; Smith-Vaughan, Heidi C; Leach, Amanda J; Paton, James C

2011-05-05

The bacterial factors responsible for the variation in invasive potential between different clones and serotypes of Streptococcus pneumoniae are largely unknown. Therefore, the isolation of rare serotype 1 carriage strains in Indigenous Australian communities provided a unique opportunity to compare the genomes of non-invasive and invasive isolates of the same serotype in order to identify such factors. The human virulence status of non-invasive, intermediately virulent and highly virulent serotype 1 isolates was reflected in mice and showed that whilst both human non-invasive and highly virulent isolates were able to colonize the murine nasopharynx equally, only the human highly virulent isolates were able to invade and survive in the murine lungs and blood. Genomic sequencing comparisons between these isolates identified 8 regions >1 kb in size that were specific to only the highly virulent isolates, and included a version of the pneumococcal pathogenicity island 1 variable region (PPI-1v), phage-associated adherence factors, transporters and metabolic enzymes. In particular, a phage-associated endolysin, a putative iron/lead permease and an operon within PPI-1v exhibited niche-specific changes in expression that suggest important roles for these genes in the lungs and blood. Moreover, in vivo competition between pneumococci carrying PPI-1v derivatives representing the two identified versions of the region showed that the version of PPI-1v in the highly virulent isolates was more competitive than the version from the less virulent isolates in the nasopharyngeal tissue, blood and lungs. This study is the first to perform genomic comparisons between serotype 1 isolates with distinct virulence profiles that correlate between mice and humans, and has highlighted the important role that hypervariable genomic loci, such as PPI-1v, play in pneumococcal disease. The findings of this study have important implications for understanding the processes that drive progression from colonization to invasive disease and will help direct the development of novel therapeutic strategies.

Detection of virulence genes determining the ability to adhere and invade in Campylobacter spp. from cattle and swine in Poland.

PubMed

Wysok, Beata; Wojtacka, Joanna

2018-02-01

The aim of the study was to determine the prevalence of virulence genes responsible for the adhesion (flaA, cadF and racR) and invasion (virB11, iam and pldA) in Campylobacter isolates from cattle and swine and determine their adherence and invasion abilities. The studies conducted revealed high prevalence rate of adherence and invasion associated genes irrespective of the isolates origin. All Campylobacter strains of swine and cattle origin adhered to HeLa cells at mean level 0.1099% ± SD 0.1341% and 0.0845% ± SD 0.1304% of starting viable inoculum, respectively. However swine isolates exhibited higher invasion abilities (0.0012% ± SD 0.0011%) compared to bovine isolates (0.00038% ± SD 0.00055%). The results obtained revealed significantly positive correlation between invasion and adherence abilities of swine origin isolates (R = 0.4867 in regard to C. jejuni and R = 0.4507 in regard to C. coli) and bovine origin isolates (R = 0.726 in regard to C. jejuni). Bacterial virulence is multifactorial and it is affected by the expression of virulence genes. Moreover the presence of virulence genes determines the ability of Campylobacter isolates to adhere and invade the cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

Highly virulent M1 Streptococcus pyogenes isolates resistant to clindamycin.

PubMed

Plainvert, C; Martin, C; Loubinoux, J; Touak, G; Dmytruk, N; Collobert, G; Fouet, A; Ploy, M-C; Poyart, C

2015-01-01

Emm1-type group A Streptococcus (GAS), or Streptococcus pyogenes, is mostly responsible for invasive infections such as necrotizing fasciitis (NF) and streptococcal toxic shock syndrome (STSS). The recommended treatment of severe invasive GAS infections is a combination of clindamycin and penicillin. Until 2012, almost all emm1 isolates were susceptible to clindamycin. We aimed to identify the phenotypic and genotypic characteristics of emm1 GAS clone resistant to clindamycin. GAS strains were characterized by emm sequence typing, detection of genes encoding pyrogenic exotoxins or superantigens. Cluster analysis was performed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Antibiotic susceptibility was assessed using disk diffusion and resistance genes were detected by PCR. A total of 1321 GAS invasive isolates were analyzed between January 2011 and December 2012. The overall number of invasive isolates resistant to clindamycin was 52 (3.9%); seven of them were emm1 isolates. All isolates had the same genomic markers: macrolide resistance due to the presence of the erm(B) gene, emm subtype 1.0, the same toxin or superantigen profile, PFGE pattern and sequence type. This is the first description of highly virulent GAS emm1 isolates resistant to clindamycin in France. This article strengthens the need for monitoring the epidemiology of invasive GAS strains as they could lead to changes in treatment guidelines. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Severe invasive streptococcal infection by Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis.

PubMed

Watanabe, Shinya; Takemoto, Norihiko; Ogura, Kohei; Miyoshi-Akiyama, Tohru

2016-01-01

Streptococcus pyogenes, a group A Streptococcus (GAS), has been recognized as the causative pathogen in patients with severe invasive streptococcal infection with or without necrotizing fasciitis. In recent epidemiological studies, Streptococcus dysgalactiae subsp. equisimilis (SDSE) has been isolated from severe invasive streptococcal infection. Complete genome sequence showed that SDSE is the closest bacterial species to GAS, with approximately 70% of genome coverage. SDSE, however, lacks several key virulence factors present in GAS, such as SPE-B, the hyaluronan synthesis operon and active superantigen against human immune cells. A key event in the ability of GAS to cause severe invasive streptococcal infection was shown to be the acquisition of novel genetic traits such as phages. Strikingly, however, during severe invasive infection, GAS destroys its own covRS two-component system, which negatively regulates many virulence factor genes, resulting in a hyper-virulent phenotype. In contrast, this phenomenon has not been observed in SDSE. The present review describes the epidemiology of severe invasive streptococcal infection and the detailed pathogenic mechanisms of GAS and SDSE, emphasizing findings from their genome sequences and analyses of gene expression. © 2015 The Societies and John Wiley & Sons Australia, Ltd.

Fungal endophytes from seeds of invasive, non-native Phragmites australis and their potential role in germination and seedling growth

USGS Publications Warehouse

Shearin, Zackery R. C.; Filipek, Matthew; Desai, Rushvi; Bickford, Wesley A.; Kowalski, Kurt P.; Clay, Keith

2018-01-01

Background and aimsWe characterized fungal endophytes of seeds of invasive, non-native Phragmites from three sites in the Great Lakes region to determine if fungal symbiosis could contribute to invasiveness through their effects on seed germination and seedling growth.MethodsField-collected seeds were surface sterilized and plated on agar to culture endophytes for ITS sequencing. Prevalence of specific endophytes from germinated and non-germinated seeds, and from seedlings, was compared.ResultsOne-third of 740 seeds yielded endophyte isolates. Fifteen taxa were identified with Alternaria sp. representing 54% of all isolates followed by Phoma sp. (21%) and Penicillium corylophilum (12%). Overall germination of seeds producing an isolate (36%) was significantly higher than seeds not producing an isolate (20%). Penicillium in particular was strongly associated with increased germination of seeds from one site. Sixty-three isolates and 11 taxa were also obtained from 30 seedlings where Phoma, Penicillium and Alternaria respectively were most prevalent. There was a significant effect of isolating an endophyte from the seed on seedling growth.ConclusionsThese results suggest that many endophyte taxa are transmitted in seeds and can increase seed germination and seedling growth of invasive Phragmites. The role of fungal endophytes in host establishment, growth and invasiveness in nature requires further research.

Emerging multidrug-resistant Candida duobushaemulonii infections in Panama hospitals: importance of laboratory surveillance and accurate identification.

PubMed

Ramos, Ruben; Caceres, Diego H; Perez, Marilyn; Garcia, Nicole; Castillo, Wendy; Santiago, Erika; Borace, Jovanna; Lockhart, Shawn R; Berkow, Elizabeth L; Hayer, Lizbeth; Espinosa-Bode, Andres; Moreno, Jose; Jackson, Brendan R; Moran, Jackeline; Chiller, Tom; de Villarreal, Gloriela; Sosa, Nestor; Vallabhaneni, Snigdha

2018-04-25

Candida duobushaemulonii , a yeast closely related to Candida auris, is thought to rarely cause infections, and is often misidentified. In October 2016, the Panamanian Ministry of Health implemented laboratory surveillance for C. auris Suspected C. auris isolates were forwarded to the national reference laboratory for identification by Matrix Assisted Laser Desorption Ionization-Time of Flight mass spectrometry and antifungal susceptibility testing. During November 2016-May 2017, 17 of 36 (47%) isolates suspected to be C. auris were identified as C. duobushaemulonii. These 17 isolates were obtained from 14 patients at six hospitals. Ten patients, including three children, had bloodstream infections, MICs for fluconazole, voriconazole, and amphotericin B were elevated. No resistance to echinocandins was observed. C. duobushaemulonii causes more invasive infections than previously appreciated, and poses a substantial problem given it is resistant to multiple antifungals. Expanded laboratory surveillance is an important step in the detection and control of such emerging pathogens. Copyright © 2018 American Society for Microbiology.

[Laboratory surveillance for invasive meningococcal disease in Chile, 2006-2012].

PubMed

Araya, Pamela; Díaz, Janepsy; Seoane, Mabel; Fernández, Jorge; Terrazas, Solana; Canals, Andrea; Vaquero, Alejandra; Barra, Gisselle; Hormazábal, Juan C; Pidal, Paola; Valenzuela, M Teresa

2014-08-01

Laboratory surveillance of Invasive Meningococcal Disease (IMD) is performed by the Institute of Public Health of Chile. It confirms identification, classifies in serogroups and analyzes the genetic profiles of Neisseria meningitidis isolates from laboratories throughout the country. To show the results of this surveillance from 2006 to 2012. A descriptive data analysis of the confirmed cases of IMD and serological characterization, susceptibility and genetic profiles of the isolates. The analysis was disaggregated by serogroup, age and region. From 2006 to 2012, 486 isolates of N. meningitidis were confirmed. In 2011 a rise in IMD rates was observed due to an increase in W serogroup cases, mainly affecting children aged 5 years or less. Serogroup W became the most prevalent during 2012 (58.3%), replacing the historically prevalent serogroup B. Predominating strains belonged to ST-32 complex/ET-5 complex (40, 4% of strains) and ST-41/44 complex/ Lineage 3 (45, 9% of strains). Laboratory surveillance has allowed the early detection of increasing IMD caused by serogroup W, which is emergent in Chile. This information has reinforced the daily monitoring of new cases, in collaboration with all the clinical laboratories of the country.

Changes in Cryphonectria parasitica Populations Affect Natural Biological Control of Chestnut Blight.

PubMed

Ježić, Marin; Mlinarec, Jelena; Vuković, Rosemary; Katanić, Zorana; Krstin, Ljiljana; Nuskern, Lucija; Poljak, Igor; Idžojtić, Marilena; Tkalec, Mirta; Ćurković-Perica, Mirna

2018-07-01

Invasive species, especially plant pathogens, have a potential to completely eradicate native plant species and remodel landscapes. Tripartite interactions among sweet chestnut (Castanea sativa), chestnut blight-causing invasive fungus Cryphonectria parasitica, and hyperparasitic virus Cryphonectria hypovirus 1 (CHV1) were studied in two populations. The number of different vegetative compatibility (vc) types of C. parasitica more than doubled over the 10 years, while the hypovirulence incidence dropped in one population and slightly increased in the other one. Over the course of our 3-year monitoring experiment, the prevalence of hypovirulent isolates obtained from monitored cankers increased slowly (i.e., more hypovirulent isolates were being obtained from the same cankers over time). Within studied cankers, considerable changes in vc type and CHV1 presence were observed, indicating a highly dynamic system in which virulent and hypovirulent mycelia, sometimes of discordant vc types, often appeared together. The increase in hypovirulence prevalence did not have any observable curative effect on the cankers and, occasionally, reactivation of healed cankers by new, virulent C. parasitica isolates was observed. Both short- and long-term observations and revalidation of the infected plant populations are necessary to accurately estimate disease progress and formulate an adequate disease management strategy.

Identifying factors linked to the occurrence of alien gastropods in isolated woodland water bodies

NASA Astrophysics Data System (ADS)

Spyra, Aneta; Strzelec, Małgorzata

2014-03-01

Biological invasions are a significant component of human-caused global change and is widely regarded as one of the main threats to natural biodiversity. Isolated anthropogenic water bodies created in the areas that are deprived of natural freshwater habitats allow the survival and reproduction of alien species on newly settled sites. They are often small with water level fluctuations causing frequent environmental disturbances. The colonisation success may be the result of the rate of their degradation. The aims of the study were to determine the environmental conditions that affect the existence of alien species of gastropods in this type of aquatic environment and to examine whether the occurrence of non-native species affects the community structure of the native species. This study made it possible to group woodland ponds according to the occurrence of the three invasive species in snail communities and discuss the environmental conditions present in these pond types. Analysis of water properties emphasised the distinctiveness of the selected pond types. In ponds of the Potamopyrgus antipodarum type, we found the highest values of some parameters mainly hardness, conductivity, and content of calcium and chlorides, in contrast with the Physella acuta type, which were characterised by the lowest values except for phosphates and nitrites. In the Ferrissia fragilis type, we found the highest nitrate content. Data on the occurrence of alien species in different water environments play an important role in actions which are taken to prevent new invasions and spread of non-native species as well as to reduce future impacts of invaders.

Identifying factors linked to the occurrence of alien gastropods in isolated woodland water bodies.

PubMed

Spyra, Aneta; Strzelec, Małgorzata

2014-03-01

Biological invasions are a significant component of human-caused global change and is widely regarded as one of the main threats to natural biodiversity. Isolated anthropogenic water bodies created in the areas that are deprived of natural freshwater habitats allow the survival and reproduction of alien species on newly settled sites. They are often small with water level fluctuations causing frequent environmental disturbances. The colonisation success may be the result of the rate of their degradation. The aims of the study were to determine the environmental conditions that affect the existence of alien species of gastropods in this type of aquatic environment and to examine whether the occurrence of non-native species affects the community structure of the native species. This study made it possible to group woodland ponds according to the occurrence of the three invasive species in snail communities and discuss the environmental conditions present in these pond types. Analysis of water properties emphasised the distinctiveness of the selected pond types. In ponds of the Potamopyrgus antipodarum type, we found the highest values of some parameters mainly hardness, conductivity, and content of calcium and chlorides, in contrast with the Physella acuta type, which were characterised by the lowest values except for phosphates and nitrites. In the Ferrissia fragilis type, we found the highest nitrate content. Data on the occurrence of alien species in different water environments play an important role in actions which are taken to prevent new invasions and spread of non-native species as well as to reduce future impacts of invaders.

Improvement Rate of Acute Otitis Media Caused by Haemophilus influenzae at 1 Week Is Significantly Associated with Time to Recovery

PubMed Central

Yamazaki, Yoshitaka; Qin, Liang; Okitsu, Naohiro; Yahara, Koji; Irimada, Mihoko; Hirakata, Yoichi; Kaku, Mitsuo; Kobayashi, Toshimitsu; Watanabe, Hiroshi

2013-01-01

Acute otitis media (AOM) is the most common upper respiratory tract infection in childhood. Children with AOM were enrolled at Tohoku Rosai Hospital between July 2006 and June 2011 if their middle ear fluid cultures after tympanocentesis yielded only Haemophilus influenzae. The susceptibilities of the isolates to ampicillin were determined, and microtiter biofilm assays and invasion assays using BEAS-2B cells were performed. The association between these bacterial characteristics and clinical relapses of AOM and treatment failures was evaluated. Seventy-four children (39 boys and 35 girls) with a median age of 1 year (interquartile range [IQR], 0.25 to 2 years) were enrolled. Among 74 H. influenzae isolates, 37 showed intermediate resistance or resistance to ampicillin (MIC, ≥2 μg/ml). In the microtiter biofilm assay, the median optical density at 600 nm (OD600) was 0.68 (IQR, 0.24 to 1.02), and 70 isolates formed biofilms. The median invasion rate was 15% (IQR, 0 to 10%), and 46 isolates invaded BEAS-2B cells. Relapses and treatment failures occurred in 19 and 6 children, respectively. There was no significant difference in the invasion rates between patients with and those without relapses or treatment failures. Also, there was no significant association between biofilm formation and relapse or treatment failure. The improvements in the severity scores after 1 week were significantly associated with the recovery time (P < 0.0001). We did not identify any significant association between relapse or treatment failure and bacterial factors. AOM has a multifactorial etiology, and this may explain why we could not find a significant association. An improvement in the severity score after 1 week of treatment may be a useful predictor of the outcome of AOM. PMID:23966504

Candidemia-induced pediatric sepsis and its association with free radicals, nitric oxide, and cytokine level in host.

PubMed

Kumar, Dharmendra; Kumar, Abhai; Singh, Smita; Tilak, Ragini

2015-04-01

Candida species has become the seventh most frequent causal microorganisms of nosocomial sepsis. Prematurity and low birth weights are strongly associated with the development of neonatal nosocomial bloodstream infections. Candida albicans has been the species most often associated with neonatal infections, but recently, there has been a changing pattern in the isolates recovered from neonates with invasive candidiasis, which poses resistance to the existing class of azoles such as fluconazole antifungals along with cross resistance to newer triazoles, which results in a therapeutic challenge in invasive fungal infections causing high incidence of mortality. Candida species was isolated from blood of neonates and children younger than 15 years admitted to hospital and susceptible for Candida-induced sepsis. Polymerase chain reaction-based identification and confirmation of individual Candida species were done using DNA sequencing. Antibiotic susceptibility assay and resistance pattern for fluconazole, voriconazole, and amphotericin were done for all the isolates. Furthermore, the change in free radical, cytokine release, and nitric oxide synthase expression and nitric oxide release from polymorphonuclear leukocytes isolated from control and pediatric sepsis cases were also performed. The present study probably for the first time reports the change in increasing incidence of nonalbicans Candida-induced sepsis in neonates and children admitted to the intensive care unit of hospital, and current antibiotics load posing resistance for antifungal treatment strategy and provide serious threats in future treatment. The increase in free radicals in polymorphonuclear leukocytes and increase in expression of nitric oxide synthase expression and nitric oxide release in Candida-infected pediatric sepsis cases underlie the role of host factor in dissemination and invasiveness of infection from exogenous sources and pathogenesis of systemic inflammation during sepsis. Copyright © 2014 Elsevier Inc. All rights reserved.

Antimicrobial resistance and management of invasive Salmonella disease.

PubMed

Kariuki, Samuel; Gordon, Melita A; Feasey, Nicholas; Parry, Christopher M

2015-06-19

Invasive Salmonella infections (typhoidal and non-typhoidal) cause a huge burden of illness estimated at nearly 3.4 million cases and over 600,000 deaths annually especially in resource-limited settings. Invasive non-typhoidal Salmonella (iNTS) infections are particularly important in immunosuppressed populations especially in sub-Saharan Africa, causing a mortality of 20-30% in vulnerable children below 5 years of age. In these settings, where routine surveillance for antimicrobial resistance is rare or non-existent, reports of 50-75% multidrug resistance (MDR) in NTS are common, including strains of NTS also resistant to flouroquinolones and 3rd generation cephalosporins. Typhoid (enteric) fever caused by Salmonella Typhi and Salmonella Paratyphi A remains a major public health problem in many parts of Asia and Africa. Currently over a third of isolates in many endemic areas are MDR, and diminished susceptibility or resistance to fluoroquinolones, the drugs of choice for MDR cases over the last decade is an increasing problem. The situation is particularly worrying in resource-limited settings where the few remaining effective antimicrobials are either unavailable or altogether too expensive to be afforded by either the general public or by public health services. Although the prudent use of effective antimicrobials, improved hygiene and sanitation and the discovery of new antimicrobial agents may offer hope for the management of invasive salmonella infections, it is essential to consider other interventions including the wider use of WHO recommended typhoid vaccines and the acceleration of trials for novel iNTS vaccines. The main objective of this review is to describe existing data on the prevalence and epidemiology of antimicrobial resistant invasive Salmonella infections and how this affects the management of these infections, especially in endemic developing countries. Copyright © 2015. Published by Elsevier Ltd.

Antimicrobial resistance and management of invasive Salmonella disease

PubMed Central

Kariuki, Samuel; Gordon, Melita A.; Feasey, Nicholas; Parry, Christopher M

2015-01-01

Invasive Salmonella infections (typhoidal and non-typhoidal) cause a huge burden of illness estimated at nearly 3.4 million cases and over 600,000 deaths annually especially in resource-limited settings. Invasive non-typhoidal Salmonella (iNTS) infections are particularly important in immunosuppressed populations especially in sub-Saharan Africa, causing a mortality of 20–30% in vulnerable children below 5 years of age. In these settings, where routine surveillance for antimicrobial resistance is rare or non-existent, reports of 50–75% multidrug resistance (MDR) in NTS are common, including strains of NTS also resistant to flouroquinolones and 3rd generation cephalosporins. Typhoid (enteric) fever caused by Salmonella Typhi and Salmonella Paratyphi A remains a major public health problem in many parts of Asia and Africa. Currently over a third of isolates in many endemic areas are MDR, and diminished susceptibility or resistance to fluoroquinolones, the drugs of choice for MDR cases over the last decade is an increasing problem. The situation is particularly worrying in resource-limited settings where the few remaining effective antimicrobials are either unavailable or altogether too expensive to be afforded by either the general public or by public health services. Although the prudent use of effective antimicrobials, improved hygiene and sanitation and the discovery of new antimicrobial agents may offer hope for the management of invasive salmonella infections, it is essential to consider other interventions including the wider use of WHO recommended typhoid vaccines and the acceleration of trials for novel iNTS vaccines. The main objective of this review is to describe existing data on the prevalence and epidemiology of antimicrobial resistant invasive Salmonella infections and how this affects the management of these infections, especially in endemic developing countries. PMID:25912288

Prevalence and antimicrobial susceptibility of Vibrio parahaemolyticus isolated from retail shrimps in Malaysia.

PubMed

Letchumanan, Vengadesh; Yin, Wai-Fong; Lee, Learn-Han; Chan, Kok-Gan

2015-01-01

Vibrio parahaemolyticus is a marine and estuarine bacterium that has been the leading cause of foodborne outbreaks which leads to a significant threat to human health worldwide. Consumption of seafood contaminated with V. parahaemolyticus causes acute gastroenteritis in individuals. The bacterium poses two main virulence factor including the thermostable direct hemolysin (tdh) which is a pore-forming protein that contributes to the invasiveness of the bacterium in humans and TDH-related hemolysin (trh), which plays a similar role as tdh in the disease pathogenesis. This study aimed to investigate the antimicrobial resistance V. parahaemolyticus strains in shrimps purchased from wetmarkets and supermarkets. The toxR-based PCR assay indicated that a total of 57.8% (185/320) isolates were positive for V. parahaemolyticus. Only 10% (19/185) toxR-positive isolate exhibit the trh gene and none of the isolates were tested positive for tdh. The MAR index was measured for 14 common antimicrobial agents. The results indicated 98% of the isolates were highly susceptible to imipenem, ampicillin sulbactam (96%), chloramphenicol (95%), trimethoprim-sulfamethoxazole (93%), gentamicin (85%), levofloxacin (83%), and tetracycline (82%). The chloramphenicol (catA2) and kanamycin (aphA-3) resistance genes were detected in the resistant V. parahaemolyticus isolates. Our results demonstrate that shrimps are contaminated with V. parahaemolyticus, some of which carry the trh-gene thus being potential to cause food borne illness. The occurrence of multidrug resistance strains in the environment could be an indication of excessive usage of antibiotics in agriculture and aquaculture fields.

Molecular characterization of fluoroquinolone and/or cephalosporin resistance in Shigella sonnei isolates from yaks.

PubMed

Zhu, Zhen; Shi, Yuxiang; Zhou, Xuzheng; Li, Bing; Zhang, Jiyu

2018-06-07

Members of the genus Shigella are intestinal pathogens and a major cause of seasonal outbreaks of bacterial diarrhea worldwide. Although humans are the conventional hosts of Shigella species, expansion of the Shigella host range to certain animals was recently reported. To investigate the prevalence of Shigella sonnei (S. sonnei) in yaks and perform molecular characterization, we analyzed 1132 fresh yak diarrheal stool samples and collected a total of 44 S. sonnei isolates. We performed multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) with XbaI-digested DNA to study genetic relatedness among the 44 isolates, which were differentiated into 4 sequence types (STs) and 32 PFGE types (PTs). All isolates harbored virulence genes, and 87.36% tested positive for invasion plasmid antigen H (ipaH), invasion associated locus (ial) and the Shigella enterotoxin gene sen. According to the results of antimicrobial susceptibility tests, 45.45% (20/44) were resistant to fluoroquinolones and/or cephalosporin. By sequencing the quinolone resistance determining region (QRDR) genes, we identified double mutations in gyrA (Ser83-Leu and Asp87-Asn) and a single mutation in parC (Ser80-Ile). All 12 fluoroquinolone-resistant S. sonnei isolates tested positive for the aac(6')-Ib-cr gene but negative for qepA. Three isolates harbored qnr genes, including two with qnrS and one with qnrB. In addition, three types of β-lactamase genes, bla TEM-1 , bla OXA-1 and bla CTX-M-14/79 , were detected in cephalosporin-resistant isolates. The findings of this study have enriched our knowledge of fluoroquinolone- and/or cephalosporin-resistant S. sonnei isolates from yaks, which has important public health significance.

Antifungal susceptibilities of Candida, Cryptococcus neoformans and Aspergillus fumigatus from the Asia and Western Pacific region: data from the SENTRY antifungal surveillance program (2010-2012).

PubMed

Pfaller, Michael A; Messer, Shawn A; Jones, Ronald N; Castanheira, Mariana

2015-09-01

The SENTRY Antifungal Surveillance Program monitors global susceptibility rates of newer and established antifungal agents. We report the in vitro activity of seven antifungal agents against 496 contemporary clinical isolates of yeasts and molds. The isolates were obtained from 20 laboratories in the Asia-Western Pacific (APAC) region during 2010 through 2012. Anidulafungin, caspofungin, micafungin, fluconazole, itraconazole, posaconazole and voriconazole were susceptibility tested using CLSI methods and species-specific interpretive criteria. Sequencing of fks hot spots was performed for echinocandin-resistant strains. Isolates included 13 species of Candida (n=460), 5 species of non-Candida yeasts (21), 5 species of Aspergillus (11) and 4 other molds. Echinocandin resistance was uncommon among eight species of Candida and was only detected in three isolates of Candida glabrata, two from Australia harboring mutations in fks1 (F625S) and fks2 (S663P). Resistance to the azoles was much more common and was observed among all species with the exception of Candida dubliniensis. Fluconazole resistance rates observed with C. glabrata (6.8%) was comparable to that seen with Candida parapsilosis (5.7%) and Candida tropicalis (3.6%). Cross resistance among the triazoles was seen with each of these three species. The mold-active azoles and the echinocandins were all active against isolates of Aspergillus fumigatus. Azole resistance was not detected among the isolates of Cryptococcus neoformans. Antifungal resistance is uncommon among isolates of fungi causing invasive fungal infections in the APAC region. As in other regions of the world, emerging resistance to the echinocandins among invasive isolates of C. glabrata bears close monitoring.

Antimicrobial resistance in Salmonella that caused foodborne disease outbreaks: United States, 2003–2012

PubMed Central

BROWN, A. C.; GRASS, J. E.; RICHARDSON, L. C.; NISLER, A. L.; BICKNESE, A. S.; GOULD, L. H.

2016-01-01

SUMMARY Although most non-typhoidal Salmonella illnesses are self-limiting, antimicrobial treatment is critical for invasive infections. To describe resistance in Salmonella that caused foodborne outbreaks in the United States, we linked outbreaks submitted to the Foodborne Disease Outbreak Surveillance System to isolate susceptibility data in the National Antimicrobial Resistance Monitoring System. Resistant outbreaks were defined as those linked to one or more isolates with resistance to at least one antimicrobial drug. Multidrug resistant (MDR) outbreaks had at least one isolate resistant to three or more antimicrobial classes. Twenty-one per cent (37/176) of linked outbreaks were resistant. In outbreaks attributed to a single food group, 73% (16/22) of resistant outbreaks and 46% (31/68) of non-resistant outbreaks were attributed to foods from land animals (P < 0.05). MDR Salmonella with clinically important resistance caused 29% (14/48) of outbreaks from land animals and 8% (3/40) of outbreaks from plant products (P < 0.01). In our study, resistant Salmonella infections were more common in outbreaks attributed to foods from land animals than outbreaks from foods from plants or aquatic animals. Antimicrobial susceptibility data on isolates from foodborne Salmonella outbreaks can help determine which foods are associated with resistant infections. PMID:27919296

Antimicrobial resistance in Salmonella that caused foodborne disease outbreaks: United States, 2003-2012.

PubMed

Brown, A C; Grass, J E; Richardson, L C; Nisler, A L; Bicknese, A S; Gould, L H

2017-03-01

Although most non-typhoidal Salmonella illnesses are self-limiting, antimicrobial treatment is critical for invasive infections. To describe resistance in Salmonella that caused foodborne outbreaks in the United States, we linked outbreaks submitted to the Foodborne Disease Outbreak Surveillance System to isolate susceptibility data in the National Antimicrobial Resistance Monitoring System. Resistant outbreaks were defined as those linked to one or more isolates with resistance to at least one antimicrobial drug. Multidrug resistant (MDR) outbreaks had at least one isolate resistant to three or more antimicrobial classes. Twenty-one per cent (37/176) of linked outbreaks were resistant. In outbreaks attributed to a single food group, 73% (16/22) of resistant outbreaks and 46% (31/68) of non-resistant outbreaks were attributed to foods from land animals (P < 0·05). MDR Salmonella with clinically important resistance caused 29% (14/48) of outbreaks from land animals and 8% (3/40) of outbreaks from plant products (P < 0·01). In our study, resistant Salmonella infections were more common in outbreaks attributed to foods from land animals than outbreaks from foods from plants or aquatic animals. Antimicrobial susceptibility data on isolates from foodborne Salmonella outbreaks can help determine which foods are associated with resistant infections.

Antimicrobial Susceptibility Survey of Streptococcus pyogenes Isolated in Japan from Patients with Severe Invasive Group A Streptococcal Infections

PubMed Central

Ikebe, Tadayoshi; Hirasawa, Kyoko; Suzuki, Rieko; Isobe, Junko; Tanaka, Daisuke; Katsukawa, Chihiro; Kawahara, Ryuji; Tomita, Masaaki; Ogata, Kikuyo; Endoh, Miyoko; Okuno, Rumi; Watanabe, Haruo

2005-01-01

We assessed antimicrobial susceptibility against 211 Streptococcus pyogenes strains isolated from patients with severe invasive group A streptococcal infections. Overall, 3.8, 1.4, 1.4, and 0.5% of the isolates were resistant to erythromycin, clindamycin, telithromycin, and ciprofloxacin, respectively, and 10.4% had intermediate resistance to ciprofloxacin. All isolates were susceptible to ampicillin and cefotaxime. PMID:15673769

Manuka honey inhibits adhesion and invasion of medically important wound bacteria in vitro.

PubMed

Maddocks, Sarah Elizabeth; Jenkins, Rowena Eleri; Rowlands, Richard Samuel; Purdy, Kevin John; Cooper, Rose Agnes

2013-12-01

To characterize the effect of manuka honey on medically important wound bacteria in vitro, focusing on its antiadhesive properties. Crystal violet biofilm assays, fluorescent microscopy, protein adhesion assay and gentamicin protection assay were used to determine the impact of manuka honey on biofilm formation, human protein binding and adherence to/invasion into human keratinocytes. Manuka honey effectively disrupted and caused extensive cell death in biofilms of Staphylococcus aureus, Pseudomonas aeruginosa and Streptococcus pyogenes. Sublethal doses of manuka honey inhibited bacterial adhesion to the fibronectin, fibrinogen and collagen. Manuka honey impaired adhesion of laboratory and clinical isolates of S. aureus, P. aeruginosa and S. pyogenes to human keratinocytes in vitro, and inhibited invasion by S. pyogenes and homogeneous vancomycin intermediate S. aureus. Manuka honey can directly affect bacterial cells embedded in a biofilm and exhibits antiadhesive properties against three common wound pathogens.

Occurrence of the invasion associated marker (iam) in Campylobacter jejuni isolated from cattle

PubMed Central

2011-01-01

Background The invasion associated marker (iam) has been detected in the majority of invasive Campylobacter jejuni retrieved from humans. Furthermore, the detection of iam in C. jejuni isolated from two important hosts, humans and chickens, suggested a role for this marker in C. jejuni's colonization of multiple hosts. However, no data exist regarding the occurrence of this marker in C. jejuni isolated from non-poultry food-animals such as cattle, an increasingly important source for human infections. Since little is known about the genetics associated with C. jejuni's capability for colonizing physiologically disparate hosts, we investigated the occurrence of the iam in C. jejuni isolated from cattle and assessed the potential of iam-containing cattle and human isolates for chicken colonization and human cell invasion. Results Simultaneous RAPD typing and iam-specific PCR analysis of 129 C. jejuni isolated from 1171 cattle fecal samples showed that 8 (6.2%) of the isolates were iam-positive, while 7 (54%) of human-associated isolates were iam-positive. The iam sequences were mostly heterogeneous and occurred in diverse genetic backgrounds. All iam-positive isolates were motile and possessed important genes (cadF, ciaB, cdtB) associated with adhesion and virulence. Although certain iam-containing isolates invaded and survived in INT-407 cells in high numbers and successfully colonized live chickens, there was no clear association between the occurrence, allelic sequence, and expression levels of the iam and the aforementioned phenotypes. Conclusions We show that the prevalence of iam in cattle C. jejuni is relatively lower as compared to isolates occurring in humans and chickens. In addition, iam was polymorphic and certain alleles occur in cattle isolates that were capable of colonizing and invading chickens and human intestinal cells, respectively. However, the iam did not appear to contribute to the cattle-associated C. jejuni's potential for invasion and intracellular survival in human intestinal cells as well as chicken colonization. PMID:22208406

Haemophilus parainfluenzae meningitis in an adult associated with acute otitis media.

PubMed

Cardines, Rita; Giufrè, Maria; Ciofi degli Atti, Marta Luisa; Accogli, Marisa; Mastrantonio, Paola; Cerquetti, Marina

2009-04-01

A case of Haemophilus parainfluenzae meningitis in a woman with a 3-day history of acute otitis media is reported. Her medical history included bladder cancer surgery. Unequivocal identification of the isolate was obtained by using molecular techniques such as 16S rRNA sequencing besides to conventional culture methods. To investigate bacterial virulent traits possibly related to invasive properties, in vitro serum resistance of our isolate was analyzed, but it was found serum susceptible. Our study demonstrates that H. parainfluenzae can be considered an opportunistic pathogen able to cause life-threatening infections not only in children but also in patients with underlying conditions.

Natural Variant of Collagen-Like Protein A in Serotype M3 Group A Streptococcus Increases Adherence and Decreases Invasive Potential

PubMed Central

Jewell, Brittany E.; Versalovic, Erika M.; Olsen, Randall J.; Bachert, Beth A.; Lukomski, Slawomir; Musser, James M.

2015-01-01

Group A Streptococcus (GAS) predominantly exists as a colonizer of the human oropharynx that occasionally breaches epithelial barriers to cause invasive diseases. Despite the frequency of GAS carriage, few investigations into the contributory molecular mechanisms exist. To this end, we identified a naturally occurring polymorphism in the gene encoding the streptococcal collagen-like protein A (SclA) in GAS carrier strains. All previously sequenced invasive serotype M3 GAS possess a premature stop codon in the sclA gene truncating the protein. The carrier polymorphism is predicted to restore SclA function and was infrequently identified by targeted DNA sequencing in invasive strains of the same serotype. We demonstrate that a strain with the carrier sclA allele expressed a full-length SclA protein, while the strain with the invasive sclA allele expressed a truncated variant. An isoallelic mutant invasive strain with the carrier sclA allele exhibited decreased virulence in a mouse model of invasive disease and decreased multiplication in human blood. Further, the isoallelic invasive strain with the carrier sclA allele persisted in the mouse nasopharynx and had increased adherence to cultured epithelial cells. Repair of the premature stop codon in the invasive sclA allele restored the ability to bind the extracellular matrix proteins laminin and cellular fibronectin. These data demonstrate that a mutation in GAS carrier strains increases adherence and decreases virulence and suggest selection against increased adherence in GAS invasive isolates. PMID:25561712

Molecular characterization and antibiotic susceptibility of Haemophilus influenzae clinical isolates.

PubMed

K L Ç, Hüseyin; Akyol, Selcan; Parkan, Õmür Mustafa; Dinç, Gõkçen; Sav, Hafize; Aydemir, Gonca

2017-03-01

Haemophilus influenzae can cause invasive and severe infections in both adults and children such as otitis media, sinusitis, pneumonia, meningitis and bacteremia. The emerging antibiotic resistance in recent years against ampicillin and several other antibiotics among strains of H. influenzae gives cause for serious concern. Here, we investigate ß-lactamase (BL) activity in clinical isolates of H. influenzae, profile their resistance to antibiotics, and characterize the clonal relationship of the isolates. Antibiotic susceptibilities of 92 clinical isolates of H. influenzae (March 2011-May 2012) were determined using the disk diffusion method according to the Clinical & Laboratory Standards Institute (CLSI), and BL activity was detected using the nitrocefin disk method. The Rep-PCR method was used to characterize clonality of the isolates. All strains were found to be susceptible to levofloxacin and cefotaxime. Four isolates out of 92 (4.3%) were found resistant to ampicillin, one isolate (1.1%) was resistant to amoxicillin/clavulanic acid, 21 isolates (22.8%) were resistant to trimethoprim-sulfamethoxazole (SXT), and three isolates (3.3%) showed BL activity. One strain was BL-negative but resistant to ampicillin. The three isolates with BL activity and four isolates with resistance to ampicillin did not have a clonal relationship. Three distinct clones [clone A (with subclones A1 and A2), clone B, and clone C] were identified among the SXT-resistant strains. Most of the H. influenzae isolates in this study were susceptible to the antibiotics while SXT resistance was relatively more prevalent, which suggests that significant obstacles in the therapeutic use of antibiotics against H. influenzae strains are not expected in our region.

Pediatric Invasive Pneumococcal Disease in Guatemala City: Importance of Serotype 2.

PubMed

Gaensbauer, James T; Asturias, Edwin J; Soto, Monica; Holt, Elizabeth; Olson, Daniel; Halsey, Neal A

2016-05-01

To inform estimations of the potential impact of recently introduced pneumococcal conjugate vaccine (PCV), we report results of 11 years of pre-PCV surveillance for invasive pneumococcal disease (IPD) among children in Guatemala City. Cases of IPD in children younger than 5 years were identified by active surveillance at 3 referral hospitals in Guatemala City from October 1996 through 2007. Clinical and demographic data were obtained, and isolates of Streptococcus pneumoniae from normally sterile sites were serotyped using latex agglutination and confirmed by Quellung reaction. Four hundred fifty-two cases of IPD were identified with a case fatality rate of 21%. Meningitis was the most common cause of death (77% of all deaths) and occurred more often in infancy (median age 5 months) than other clinical syndromes. Of the 137 isolates serotyped, type 1 (26 cases, 17%), type 2 (25 cases, 16%) and type 5 (18 cases, 12%) were the most common. Serotype 2 was associated with a higher case fatality rate (28%), higher rate of meningitis (68%) and occurred in younger infants (median age, 3.5 months) than other common serotypes. Recently introduced PCV13 includes 73% of observed serotypes in the study. Infants with IPD presented at a young age. Serotype 2, rarely reported as a significant cause of IPD and not included in available PCVs, was a common cause of disease in this population. PCV13 introduction in Guatemala, begun in 2013, may not have as great an impact in disease reduction as has been observed in other countries.

Correlation of virulence genes to clinical manifestations and outcome in patients with Streptococcus dysgalactiae subspecies equisimilis bacteremia.

PubMed

Tsai, Chia-Ta; Chi, Chih-Yu; Ho, Cheng-Mao; Lin, Po-Chang; Chou, Chia-Hui; Wang, Jen-Hsien; Wang, Jui-Hsing; Lin, Hsiao-Chuan; Tien, Ni; Lin, Kuo-Hsi; Ho, Mao-Wang; Lu, Jang-Jih

2014-12-01

Streptococcus dysgalactiae subsp. equisimilis (SDSE) is increasingly recognized as a human pathogen responsible for invasive infection and streptococcal toxic shock syndrome (STSS). The pathogen possesses virulence genes that resemble those found in Streptococcus pyogenes (GAS). We analyzed the association between these specific toxic genes, clinical presentations, and outcome in patients with SDSE infections. Patients (older than 18 years) with community-acquired invasive bacteremia caused by SDSE bacteremia who were undergoing treatment at China Medical University Hospital from June 2007 to December 2010 were included in this study. Multiplex polymerase chain reaction was performed to identify virulence genes of the SDSE isolates. Demographic data, clinical presentations, and outcome in patients with SDSE infections were reviewed and analyzed. Forty patients with 41 episodes of SDSE bacteremia were reviewed. The median age of the patients with SDSE infection was 69.7 years; 55% were female and 78% had underlying diseases. Malignancy (13, 33%) and diabetes mellitus (13, 33%) were the most common comorbidities. The 30-day mortality rate was 12%. Compared with the survivors, the non-survivors had a higher rate of diabetes mellitus (80% vs. 26%), liver cirrhosis (60% vs.11%), shock (60% vs.17%), STSS (60% vs. 8%), and a high Pittsburgh bacteremia score >4 (40% vs. 6%). Most isolates had scpA, ska, saga, and slo genes, whereas speC, speG, speH, speI, speK, smez, and ssa genes were not detected. speA gene was identified only in one patient with STSS (1/6, 17%). All isolates were susceptible to penicillin, cefotaxime, levofloxacin, moxifloxacin, vancomycin, and linezolid. In invasive SDSE infections, most isolates carry putative virulence genes, such as scpA, ska, saga, and slo. Clinical SDSE isolates in Taiwan remain susceptible to penicillin cefotaxime, and levofloxacin. Copyright © 2013. Published by Elsevier B.V.

Invasive Haemophilus influenzae Infection in Patients With Cancer.

PubMed

Singh, Vivek; Nanjappa, Sowmya; Pabbathi, Smitha; Greene, John N

2017-01-01

A major cause of morbidity and mortality in patients with cancer is infection. Since the introduction of the Haemophilus influenzae type b (Hib) vaccine in the United States in the 1990s, invasive H influenzae infection has become less common. We report on 5 patients with cancer and invasive H influenzae infection. A literature review was also performed of the dominant Haemophilus subtype and the clinical features associated with the infection and concomitant cancer. Of the 17 cases found in the literature, had hematological malignancies and 1 case each had thymoma, schwannoma, teratoma, and pancreatic, Merkel cell, pharyngeal, laryngeal, and rectal carcinomas. Two cases occurred with AIDS and Kaposi sarcoma. Pneumonia with bacteremia was seen in 8 cases, whereas pleuritis, neck cellulitis, septic arthritis, meningitis, and mediastinitis were diagnosed in the others. No focus of infection was identified in 2 cases. Nontypable H influenzae (NTHi) occurred in 4 cases, and Hib was isolated in 2 cases; serotyping was not reported in the others. Leukocytosis occurred in 7 cases and lymphopenia in 3; no cases presented with neutropenia. Four isolates were positive for beta-lactamase. Susceptibility data were unavailable in 5 case patients. Among serotyped cases, 67% were of the NTHi strain - a finding consistent with the change in the epidemiology of H influenzae since the introduction of the Hib vaccine.

Emergence of Resistance among USA300 Methicillin-Resistant Staphylococcus aureus Isolates Causing Invasive Disease in the United States▿

PubMed Central

McDougal, Linda K.; Fosheim, Gregory E.; Nicholson, Ainsley; Bulens, Sandra N.; Limbago, Brandi M.; Shearer, Julia E. S.; Summers, Anne O.; Patel, Jean B.

2010-01-01

USA300 methicillin-resistant Staphylococcus aureus (MRSA) isolates are usually resistant only to oxacillin, erythromycin, and, increasingly, levofloxacin. Of these, oxacillin and levofloxacin resistances are chromosomally encoded. Plasmid-mediated clindamycin, mupirocin, and/or tetracycline resistance has been observed among USA300 isolates, but these descriptions were limited to specific patient populations or isolated occurrences. We examined the antimicrobial susceptibilities of invasive MRSA isolates from a national surveillance population in order to identify USA300 isolates with unusual, possibly emerging, plasmid-mediated antimicrobial resistance. DNA from these isolates was assayed for the presence of resistance determinants and the presence of a pSK41-like conjugative plasmid. Of 823 USA300 isolates, 72 (9%) were tetracycline resistant; 69 of these were doxycycline susceptible and tetK positive, and 3 were doxycycline resistant and tetM positive. Fifty-one (6.2%) isolates were clindamycin resistant and ermC positive; 22 (2.7%) isolates were high-level mupirocin resistant (mupA positive); 5 (0.6%) isolates were trimethoprim-sulfamethoxazole (TMP-SMZ) resistant, of which 4 were dfrA positive; and 7 (0.9%) isolates were gentamicin resistant and aac6′-aph2″ positive. Isolates with pSK41-like plasmids (n = 24) were positive for mupA (n = 19), dfrA (n = 6), aac6′-aph2″ (n = 6), tetM (n = 2), and ermC (n = 8); 20 pSK41-positive isolates were positive for two or more resistance genes. Conjugative transfer of resistance was demonstrated between four gentamicin- and mupirocin-resistant and three gentamicin- and TMP-SMZ-resistant USA300 isolates; transconjugants harbored a single pSK41-like plasmid, which was PCR positive for aac6′-aph2″ and either mupA and/or dfrA. USA300 and USA100 isolates from the same state with identical resistance profiles contained pSK41-like plasmids with indistinguishable restriction and Southern blot profiles, suggesting horizontal plasmid transfer between USA100 and USA300 isolates. PMID:20585117

In vitro expression of Streptococcus pneumoniae ply gene in human monocytes and pneumocytes.

PubMed

Hu, Da-Kang; Liu, Yang; Li, Xiang-Yang; Qu, Ying

2015-05-07

Streptococcus pneumoniae is one major cause of pneumonia in human and contains various virulence factors that contribute to pathogenesis of pneumococcal disease. This study investigated the role of pneumolysin, Ply, in facilitating S. pneumoniae invasion into the host blood stream. S. pneumoniae strains were isolated from clinical blood and sputum samples and confirmed by PCR. Expression of ply gene was assessed by infecting human monocytes and pneumocytes. A total of 23 strains of S. pneumoniae isolated from blood (n = 11) and sputum (n = 12) along with S. pneumoniae ATCC49619 were used to infect human monocyte (THP-1) and Type II pneumocyte (A549) cell lines. All clinical strains of S. pneumoniae showed higher expression of ply mRNA than the American Type Culture Collection (ATCC) strain. Among the clinical strains, blood isolates showed higher expression of ply genes than sputum isolates, i.e., 2(1.5)- to 2(1.6)-folds in THP-1 and 2(0.4)- to 2(4.9)-folds in A549 cell lines. The data from the current study demonstrated that ply gene of blood- and sputum-derived S. pneumoniae is differentially expressed in two different cell lines. Under survival pressure, ply is highly expressed in these two cell lines for blood-derived S. pneumoniae, indicating that ply gene may facilitate S. pneumoniae invasion into the host blood system.

Pythium invasion of plant-based life support systems: biological control and sources

NASA Technical Reports Server (NTRS)

Jenkins, D. G.; Cook, K. L.; Garland, J. L.; Board, K. F.; Sager, J. C. (Principal Investigator)

2000-01-01

Invasion of plant-based life support systems by plant pathogens could cause plant disease and disruption of life support capability. Root rot caused by the fungus, Pythium, was observed during tests of prototype plant growth systems containing wheat at the Kennedy Space Center (KSC). We conducted experiments to determine if the presence of complex microbial communities in the plant root zone (rhizosphere) resisted invasion by the Pythium species isolated from the wheat root. Rhizosphere inocula of different complexity (as assayed by community-level physiological profile: CLPP) were developed using a dilution/extinction approach, followed by growth in hydroponic rhizosphere. Pythium growth on wheat roots and concomitant decreases in plant growth were inversely related to the complexity of the inocula during 20-day experiments in static hydroponic systems. Pythium was found on the seeds of several different wheat cultivars used in controlled environmental studies, but it is unclear if the seed-borne fungal strain(s) were identical to the pathogenic strain recovered from the KSC studies. Attempts to control pathogens and their effects in hydroponic life support systems should include early inoculation with complex microbial communities, which is consistent with ecological theory.

Periodontal bacterial invasion and infection: contribution to atherosclerotic pathology.

PubMed

Reyes, Leticia; Herrera, David; Kozarov, Emil; Roldán, Silvia; Progulske-Fox, Ann

2013-04-01

The objective of this review was to perform a systematic evaluation of the literature reporting current scientific evidence for periodontal bacteria as contributors to atherosclerosis. Literature from epidemiological, clinical and experimental studies concerning periodontal bacteria and atherosclerosis were reviewed. Gathered data were categorized into seven "proofs" of evidence that periodontal bacteria: 1) disseminate from the oral cavity and reach systemic vascular tissues; 2) can be found in the affected tissues; 3) live within the affected site; 4) invade affected cell types in vitro; 5) induce atherosclerosis in animal models of disease; 6) non-invasive mutants of periodontal bacteria cause significantly reduced pathology in vitro and in vivo; and 7) periodontal isolates from human atheromas can cause disease in animal models of infection. Substantial evidence for proofs 1 to 6 was found. However, proof 7 has not yet been fulfilled. Despite the lack of evidence that periodontal bacteria obtained from human atheromas can cause atherosclerosis in animal models of infection, attainment of proofs 1 to 6 provides support that periodontal pathogens can contribute to atherosclerosis. © 2013 European Federation of Periodontology and American Academy of Periodontology.

Antifungal susceptibilities of Candida glabrata species complex, Candida krusei, Candida parapsilosis species complex and Candida tropicalis causing invasive candidiasis in China: 3 year national surveillance.

PubMed

Xiao, Meng; Fan, Xin; Chen, Sharon C-A; Wang, He; Sun, Zi-Yong; Liao, Kang; Chen, Shu-Lan; Yan, Yan; Kang, Mei; Hu, Zhi-Dong; Chu, Yun-Zhuo; Hu, Tie-Shi; Ni, Yu-Xing; Zou, Gui-Ling; Kong, Fanrong; Xu, Ying-Chun

2015-03-01

To define the antifungal susceptibility patterns of the most common non-albicans Candida spp. in China. We evaluated the susceptibilities to nine antifungal drugs of Candida parapsilosis species complex, Candida tropicalis, Candida glabrata species complex and Candida krusei isolates from patients with invasive candidiasis at 11 hospitals over 3 years. Isolates were identified by MALDI-TOF MS supplemented by DNA sequencing. MICs were determined by Sensititre YeastOne(TM) using current clinical breakpoints/epidemiological cut-off values to assign susceptibility (or WT), and by CLSI M44-A2 disc diffusion for fluconazole and voriconazole. Of 1072 isolates, 392 (36.6%) were C. parapsilosis species complex. C. tropicalis, C. glabrata species complex and C. krusei comprised 35.4%, 24.3% and 3.7% of the isolates, respectively. Over 99.3% of the isolates were of WT phenotype to amphotericin B and 5-flucytosine. Susceptibility/WT rates to azoles among C. parapsilosis species complex were ≥97.5%. However, 11.6% and 9.5% of C. tropicalis isolates were non-susceptible to fluconazole and voriconazole, respectively (7.1% were resistant to both). Approximately 14.3% of C. glabrata sensu stricto isolates (n = 258) were fluconazole resistant, and 11.6% of C. glabrata sensu stricto isolates were cross-resistant to fluconazole and voriconazole. All C. krusei isolates were susceptible/WT to voriconazole, posaconazole and itraconazole. Overall, 97.7%-100% of isolates were susceptible to caspofungin, micafungin and anidulafungin, but 2.3% of C. glabrata were non-susceptible to anidulafungin. There was no azole/echinocandin co-resistance. Disc diffusion and Sensititre YeastOne(TM) methods showed >95% categorical agreement for fluconazole and voriconazole. In summary, reduced azole susceptibility was seen among C. tropicalis. Resistance to echinocandins was uncommon. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Molecular and epidemiological characterization of IMP-type metallo-β-lactamase-producing Enterobacter cloacae in a Large tertiary care hospital in Japan.

PubMed

Hayakawa, Kayoko; Miyoshi-Akiyama, Tohru; Kirikae, Teruo; Nagamatsu, Maki; Shimada, Kayo; Mezaki, Kazuhisa; Sugiki, Yuko; Kuroda, Emi; Kubota, Shiho; Takeshita, Nozomi; Kutsuna, Satoshi; Tojo, Masayoshi; Ohmagari, Norio

2014-06-01

IMP-type metallo-β-lactamase enzymes have been reported in different geographical areas and in various Gram-negative bacteria. However, the risk factors and epidemiology pertaining to IMP-type metallo-β-lactamase-producing Enterobacter cloacae (IMP-producing E. cloacae) have not been systematically evaluated. We conducted a retrospective, matched case-control study of patients from whom IMP-producing E. cloacae isolates were obtained, in addition to performing thorough molecular analyses of the clinically obtained IMP-producing E. cloacae isolates. Unique cases with IMP-producing E. cloacae isolation were included. Patients with IMP-producing E. cloacae were matched to uninfected controls at a ratio of 1 to 3. Fifteen IMP-producing E. cloacae cases were identified, with five of the isolates being obtained from blood, and they were matched to 45 uninfected controls. All (100%) patients from whom IMP-producing E. cloacae isolates were obtained had indwelling devices at the time of isolation, compared with one (2.2%) uninfected control. Independent predictors for isolation of IMP-producing E. cloacae were identified as cephalosporin exposure and invasive procedures within 3 months. Although in-hospital mortality rates were similar between cases and controls (14.3% versus 13.3%), the in-hospital mortality of patients with IMP-producing E. cloacae-caused bacteremia was significantly higher (40%) than the rate in controls. IMP-producing E. cloacae isolates were frequently positive for other resistance determinants. The MICs of meropenem and imipenem were not elevated; 10 (67%) and 12 (80%) of the 15 IMP-producing E. cloacae isolates had a MIC of ≤ 1 μg/ml. A phylogenetic tree showed a close relationship among the IMP-producing E. cloacae samples. Indwelling devices, exposure to cephalosporin, and a history of invasive procedures were associated with isolation of IMP-producing E. cloacae. Screening for carbapenemase production is important in order to apply appropriate clinical management and infection control measures. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Increase of β-Lactam-Resistant Invasive Haemophilus influenzae in Sweden, 1997 to 2010

PubMed Central

Resman, Fredrik; Ristovski, Mikael; Forsgren, Arne; Kaijser, Bertil; Kronvall, Göran; Medstrand, Patrik; Melander, Eva; Odenholt, Inga

2012-01-01

The proportions of Haemophilus influenzae resistant to ampicillin and other β-lactam antibiotics have been low in Sweden compared to other countries in the Western world. However, a near-doubled proportion of nasopharyngeal Swedish H. influenzae isolates with resistance to β-lactams has been observed in the last decade. In the present study, the epidemiology and mechanisms of antimicrobial resistance of H. influenzae isolates from blood and cerebrospinal fluid in southern Sweden from 1997 to 2010 (n = 465) were studied. Antimicrobial susceptibility testing was performed using disk diffusion, and isolates with resistance to any tested β-lactam were further analyzed in detail. We identified a significantly increased (P = 0.03) proportion of β-lactam-resistant invasive H. influenzae during the study period, which was mainly attributed to a significant recent increase of β-lactamase-negative β-lactam-resistant isolates (P = 0.04). Furthermore, invasive β-lactamase-negative β-lactam-resistant H. influenzae isolates from 2007 and onwards were found in higher proportions than the corresponding proportions of nasopharyngeal isolates in a national survey. Multiple-locus sequence typing (MLST) of this group of isolates did not completely separate isolates with different resistance phenotypes. However, one cluster of β-lactamase-negative ampicillin-resistant (BLNAR) isolates was identified, and it included isolates from all geographical areas. A truncated variant of a β-lactamase gene with a promoter deletion, blaTEM-1-PΔ dominated among the β-lactamase-positive H. influenzae isolates. Our results show that the proportions of β-lactam-resistant invasive H. influenzae have increased in Sweden in the last decade. PMID:22687505

Pathogenicity of Salmonella Strains Isolated from Egg Shells and the Layer Farm Environment in Australia

PubMed Central

McWhorter, Andrea R.; Davos, Dianne

2014-01-01

In Australia, the egg industry is periodically implicated during outbreaks of Salmonella food poisoning. Salmonella enterica serovar Typhimurium and other nontyphoidal Salmonella spp., in particular, are a major concern for Australian public health. Several definitive types of Salmonella Typhimurium strains, but primarily Salmonella Typhimurium definitive type 9 (DT9), have been frequently reported during egg-related food poisoning outbreaks in Australia. The aim of the present study was to generate a pathogenicity profile of nontyphoidal Salmonella isolates obtained from Australian egg farms. To achieve this, we assessed the capacity of Salmonella isolates to cause gastrointestinal disease using both in vitro and in vivo model systems. Data from in vitro experiments demonstrated that the invasion capacity of Salmonella serovars cultured to stationary phase (liquid phase) in LB medium was between 90- and 300-fold higher than bacterial suspensions in normal saline (cultured in solid phase). During the in vivo infection trial, clinical signs of infection and mortality were observed only for mice infected with either 103 or 105 CFU of S. Typhimurium DT9. No mortality was observed for mice infected with Salmonella serovars with medium or low invasive capacity in Caco-2 cells. Pathogenicity gene profiles were also generated for all serovars included in this study. The majority of serovars tested were positive for selected virulence genes. No relationship between the presence or absence of virulence genes by PCR and either in vitro invasive capacity or in vivo pathogenicity was detected. Our data expand the knowledge of strain-to-strain variation in the pathogenicity of Australian egg industry-related Salmonella spp. PMID:25362057

Increased prevalence of group A streptococcus isolates in streptococcal toxic shock syndrome cases in Japan from 2010 to 2012.

PubMed

Ikebe, T; Tominaga, K; Shima, T; Okuno, R; Kubota, H; Ogata, K; Chiba, K; Katsukawa, C; Ohya, H; Tada, Y; Okabe, N; Watanabe, H; Ogawa, M; Ohnishi, M

2015-03-01

Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of shock, multi-organ failure, and high mortality. In Japan, appropriate notification measures based on the Infectious Disease Control law are mandatory for cases of STSS caused by β-haemolytic streptococcus. STSS is mainly caused by group A streptococcus (GAS). Although an average of 60-70 cases of GAS-induced STSS are reported annually, 143 cases were recorded in 2011. To determine the reason behind this marked increase, we characterized the emm genotype of 249 GAS isolates from STSS patients in Japan from 2010 to 2012 and performed antimicrobial susceptibility testing. The predominant genotype was found to be emm1, followed by emm89, emm12, emm28, emm3, and emm90. These six genotypes constituted more than 90% of the STSS isolates. The number of emm1, emm89, emm12, and emm28 isolates increased concomitantly with the increase in the total number of STSS cases. In particular, the number of mefA-positive emm1 isolates has escalated since 2011. Thus, the increase in the incidence of STSS can be attributed to an increase in the number of cases associated with specific genotypes.

Putative Virulence Factor Expression by Clinical and Food Isolates of Bacillus spp. after Growth in Reconstituted Infant Milk Formulae

PubMed Central

Rowan, Neil J.; Deans, Karen; Anderson, John G.; Gemmell, Curtis G.; Hunter, Iain S.; Chaithong, Thararat

2001-01-01

Forty-seven strains representing 14 different Bacillus species isolated from clinical and food samples were grown in reconstituted infant milk formulae (IMF) and subsequently assessed for adherence to, invasion of, and cytotoxicity toward HEp-2 and Caco-2 cells. Cell-free supernatant fluids from 38 strains (81%) were shown to be cytotoxic, 43 strains (91%) adhered to the test cell lines, and 23 strains (49%) demonstrated various levels of invasion. Of the 21 Bacillus cereus strains examined, 5 (24%) were invasive. A larger percentage of clinically derived Bacillus species (20%) than of similar species tested from the food environment were invasive. Increased invasion occurred after growth of selected Bacillus species in reconstituted IMF containing glucose. While PCR primer studies revealed that many different Bacillus species contained DNA sequences encoding the hemolysin BL (HBL) enterotoxin complex and B. cereus enterotoxin T, not all of these isolates expressed these diarrheagenic genes after growth in reconstituted IMF. Of the 47 Bacillus isolates examined, 3 isolates of B. cereus and 1 isolate of B. subtilis produced the HBL enterotoxin after 18 h of growth in brain heart infusion broth. However, eight isolates belonging to the species B. cereus, B. licheniformis, B. circulans, and B. megaterium were found to produce this enterotoxin after growth in reconstituted IMF when assessed with the B. cereus enterotoxin (diarrheal type) reversed passive latex agglutination (RPLA) kit. It is concluded that several Bacillus species occurring occasionally in clinical specimens and food samples are of potential medical significance due to the expression of putative virulence factors. PMID:11525980

Plumbagin reduces osteopontin-induced invasion through inhibiting the Rho-associated kinase signaling pathway in A549 cells and suppresses osteopontin-induced lung metastasis in BalB/c mice.

PubMed

Kang, Chi Gu; Im, Eunji; Lee, Hyo-Jeong; Lee, Eun-Ok

2017-05-01

Lung cancer is the second most commonly diagnosed cancer and the leading cause of cancer deaths in both men and women in the United States. It has been recently demonstrated that osteopontin (OPN) effectively inhibits cofilin activity through the focal adhesion kinase (FAK)/AKT/Rho-associated kinase (ROCK) pathway to induce the invasion of human non-small cell lung cancer (NSCLC) cells. Plumbagin was isolated from the roots of the medicinal plant Plumbago zeylanica L. and has been reported to possess anticancer activities. However, the molecular mechanisms by which plumbagin inhibits the invasion of cancer cells is still unclear. In this study, the anti-invasive and anti-metastatic mechanisms of plumbagin were investigated in OPN-treated NSCLC A549 cells. OPN effectively induced the motility and invasion of NSCLC A549 cells and H1299 cells, which was strongly suppressed by plumbagin with no evidence of cytotoxicity. In addition, lamellipodia formation at the leading edge of cells by OPN was dramatically decreased in plumbagin-treated cells. Plumbagin caused an effective inhibition in OPN-induced the expression of ROCK1 as well as the phosphorylation of LIM kinase 1 and 2 (LIMK1/2), and cofilin. OPN-induced the phosphorylation of FAK and AKT was impaired without affecting their total forms by plumbagin treatment. OPN facilitated metastatic lung colonization, which was effectively suppressed in plumbagin-treated mice. Taken together, these results suggest that plumbagin reduces OPN-induced the invasion of NSCLC A549 cells, which resulted from inhibiting the ROCK pathway mediated by the FAK/AKT pathway and suppresses lung metastasis in vivo. Copyright © 2017 Elsevier Ltd. All rights reserved.

Prevalence and antimicrobial susceptibility of Vibrio parahaemolyticus isolated from retail shrimps in Malaysia

PubMed Central

Letchumanan, Vengadesh; Yin, Wai-Fong; Lee, Learn-Han; Chan, Kok-Gan

2015-01-01

Vibrio parahaemolyticus is a marine and estuarine bacterium that has been the leading cause of foodborne outbreaks which leads to a significant threat to human health worldwide. Consumption of seafood contaminated with V. parahaemolyticus causes acute gastroenteritis in individuals. The bacterium poses two main virulence factor including the thermostable direct hemolysin (tdh) which is a pore-forming protein that contributes to the invasiveness of the bacterium in humans and TDH-related hemolysin (trh), which plays a similar role as tdh in the disease pathogenesis. This study aimed to investigate the antimicrobial resistance V. parahaemolyticus strains in shrimps purchased from wetmarkets and supermarkets. The toxR-based PCR assay indicated that a total of 57.8% (185/320) isolates were positive for V. parahaemolyticus. Only 10% (19/185) toxR-positive isolate exhibit the trh gene and none of the isolates were tested positive for tdh. The MAR index was measured for 14 common antimicrobial agents. The results indicated 98% of the isolates were highly susceptible to imipenem, ampicillin sulbactam (96%), chloramphenicol (95%), trimethoprim-sulfamethoxazole (93%), gentamicin (85%), levofloxacin (83%), and tetracycline (82%). The chloramphenicol (catA2) and kanamycin (aphA-3) resistance genes were detected in the resistant V. parahaemolyticus isolates. Our results demonstrate that shrimps are contaminated with V. parahaemolyticus, some of which carry the trh-gene thus being potential to cause food borne illness. The occurrence of multidrug resistance strains in the environment could be an indication of excessive usage of antibiotics in agriculture and aquaculture fields. PMID:25688239

Molecular characterisation of enteroinvasive Escherichia coli O136:K78 isolates from patients of a diarrhoea outbreak in China.

PubMed

Zhou, X; Xia, W; Tu, J; Xue, L; Ni, X

2015-01-01

A diarrhoea outbreak occurred in a kindergarten, which caused 21 relevant infected cases. Our object was to confirm the pathogens and their molecular characterisation. Faecal samples from 21 patients were collected on the 3rd day after their symptom onset, and a regular epidemiological investigation was conducted. Bacterial isolation was performed in accordance with standard laboratory protocol, serological and molecular characterisations were determined by serum agglutination test and real-time polymerase chain reaction (PCR) method, respectively. The pulsed field gel electrophoresis (PFGE) and 16S rRNAs were conducted to determine the homology. Eleven enteroinvasive Escherichia coli (EIEC) O136:K78 strains were isolated. The serum agglutination test showed that all strains' serotypes were E. coli (EIEC) O136:K78. Real-time PCR showed that 10 (91%) strains carried the invasion plasmid antigen H gene (ipaH), carried by all four Shigella species and EIEC. The strain that didn't carry the ipaH gene had different biochemical reactions of L-lizyna and L-rhamnose with the other strains. The complete 16S rRNA sequences showed 98.4% identity between ipaH-negative isolate and the others, and the PFGE indicated that the ipaH-negative isolate was not homological with other isolates in this diarrhoea outbreak. The diarrhoea outbreak was caused by E. coli (EIEC) O136:K78.

Group B streptococci causing neonatal infections in barcelona are a stable clonal population: 18-year surveillance.

PubMed

Martins, E R; Andreu, A; Correia, P; Juncosa, T; Bosch, J; Ramirez, M; Melo-Cristino, J

2011-08-01

We analyzed 212 group B streptococci (GBS) from newborns with invasive infections in the area of Barcelona, Spain, between 1992 and 2009, with the aim of documenting changes in the prevalences of serotypes, antimicrobial resistance, and genetic lineages and evaluating their associations with either early-onset disease (EOD) or late-onset disease (LOD). Serotypes III (n = 118) and Ia (n = 47) together accounted for nearly 78% of the isolates. All isolates carried an alpha or alpha-like protein gene, and specific associations between genes and serotypes, such as serotype Ib and bca, serotype II and bca, serotype III and rib, and serotype V and alp3, reflected the presence of particular genetic lineages. Macrolide resistance (14.2%) was significantly associated with serotype V. Pulsed-field gel electrophoresis (PFGE) clustering was an excellent predictor of serotype and antibiotic resistance. The combination of PFGE and multilocus sequence typing revealed a large number of genetically distinct lineages. Still, specific lineages were dominant in our collection, particularly the serotype III/ST17/rib lineage, which had enhanced potential to cause LOD. Serotype Ia was concentrated in a single PFGE cluster composed of two genetic lineages: ST23/eps and ST24/bca. The ST24/bca sublineage of serotype Ia, which is found infrequently elsewhere, may be emerging as an important cause of neonatal invasive infections in the Mediterranean region. In spite of the introduction of prophylaxis, resulting in a pronounced decline in the frequency of EOD, the study revealed a remarkably stable clonal structure of GBS causing neonatal infections in Barcelona over a period of 18 years.

Group B Streptococci Causing Neonatal Infections in Barcelona Are a Stable Clonal Population: 18-Year Surveillance▿

PubMed Central

Martins, E. R.; Andreu, A.; Correia, P.; Juncosa, T.; Bosch, J.; Ramirez, M.; Melo-Cristino, J.

2011-01-01

We analyzed 212 group B streptococci (GBS) from newborns with invasive infections in the area of Barcelona, Spain, between 1992 and 2009, with the aim of documenting changes in the prevalences of serotypes, antimicrobial resistance, and genetic lineages and evaluating their associations with either early-onset disease (EOD) or late-onset disease (LOD). Serotypes III (n = 118) and Ia (n = 47) together accounted for nearly 78% of the isolates. All isolates carried an alpha or alpha-like protein gene, and specific associations between genes and serotypes, such as serotype Ib and bca, serotype II and bca, serotype III and rib, and serotype V and alp3, reflected the presence of particular genetic lineages. Macrolide resistance (14.2%) was significantly associated with serotype V. Pulsed-field gel electrophoresis (PFGE) clustering was an excellent predictor of serotype and antibiotic resistance. The combination of PFGE and multilocus sequence typing revealed a large number of genetically distinct lineages. Still, specific lineages were dominant in our collection, particularly the serotype III/ST17/rib lineage, which had enhanced potential to cause LOD. Serotype Ia was concentrated in a single PFGE cluster composed of two genetic lineages: ST23/eps and ST24/bca. The ST24/bca sublineage of serotype Ia, which is found infrequently elsewhere, may be emerging as an important cause of neonatal invasive infections in the Mediterranean region. In spite of the introduction of prophylaxis, resulting in a pronounced decline in the frequency of EOD, the study revealed a remarkably stable clonal structure of GBS causing neonatal infections in Barcelona over a period of 18 years. PMID:21697333

High Incidence of Invasive Group A Streptococcus Disease Caused by Strains of Uncommon emm Types in Thunder Bay, Ontario, Canada

PubMed Central

Athey, Taryn B. T.; Teatero, Sarah; Sieswerda, Lee E.; Gubbay, Jonathan B.; Marchand-Austin, Alex; Li, Aimin; Wasserscheid, Jessica; Dewar, Ken; McGeer, Allison; Williams, David

2015-01-01

An outbreak of type emm59 invasive group A Streptococcus (iGAS) disease was declared in 2008 in Thunder Bay District, Northwestern Ontario, 2 years after a countrywide emm59 epidemic was recognized in Canada. Despite a declining number of emm59 infections since 2010, numerous cases of iGAS disease continue to be reported in the area. We collected clinical information on all iGAS cases recorded in Thunder Bay District from 2008 to 2013. We also emm typed and sequenced the genomes of all available strains isolated from 2011 to 2013 from iGAS infections and from severe cases of soft tissue infections. We used whole-genome sequencing data to investigate the population structure of GAS strains of the most frequently isolated emm types. We report an increased incidence of iGAS in Thunder Bay compared to the metropolitan area of Toronto/Peel and the province of Ontario. Illicit drug use, alcohol abuse, homelessness, and hepatitis C infection were underlying diseases or conditions that might have predisposed patients to iGAS disease. Most cases were caused by clonal strains of skin or generalist emm types (i.e., emm82, emm87, emm101, emm4, emm83, and emm114) uncommonly seen in other areas of the province. We observed rapid waxing and waning of emm types causing disease and their replacement by other emm types associated with the same tissue tropisms. Thus, iGAS disease in Thunder Bay District predominantly affects a select population of disadvantaged persons and is caused by clonally related strains of a few skin and generalist emm types less commonly associated with iGAS in other areas of Ontario. PMID:26491184

High Incidence of Invasive Group A Streptococcus Disease Caused by Strains of Uncommon emm Types in Thunder Bay, Ontario, Canada.

PubMed

Athey, Taryn B T; Teatero, Sarah; Sieswerda, Lee E; Gubbay, Jonathan B; Marchand-Austin, Alex; Li, Aimin; Wasserscheid, Jessica; Dewar, Ken; McGeer, Allison; Williams, David; Fittipaldi, Nahuel

2016-01-01

An outbreak of type emm59 invasive group A Streptococcus (iGAS) disease was declared in 2008 in Thunder Bay District, Northwestern Ontario, 2 years after a countrywide emm59 epidemic was recognized in Canada. Despite a declining number of emm59 infections since 2010, numerous cases of iGAS disease continue to be reported in the area. We collected clinical information on all iGAS cases recorded in Thunder Bay District from 2008 to 2013. We also emm typed and sequenced the genomes of all available strains isolated from 2011 to 2013 from iGAS infections and from severe cases of soft tissue infections. We used whole-genome sequencing data to investigate the population structure of GAS strains of the most frequently isolated emm types. We report an increased incidence of iGAS in Thunder Bay compared to the metropolitan area of Toronto/Peel and the province of Ontario. Illicit drug use, alcohol abuse, homelessness, and hepatitis C infection were underlying diseases or conditions that might have predisposed patients to iGAS disease. Most cases were caused by clonal strains of skin or generalist emm types (i.e., emm82, emm87, emm101, emm4, emm83, and emm114) uncommonly seen in other areas of the province. We observed rapid waxing and waning of emm types causing disease and their replacement by other emm types associated with the same tissue tropisms. Thus, iGAS disease in Thunder Bay District predominantly affects a select population of disadvantaged persons and is caused by clonally related strains of a few skin and generalist emm types less commonly associated with iGAS in other areas of Ontario. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Infiltrated Macrophages Die of Pneumolysin-Mediated Necroptosis following Pneumococcal Myocardial Invasion.

PubMed

Gilley, Ryan P; González-Juarbe, Norberto; Shenoy, Anukul T; Reyes, Luis F; Dube, Peter H; Restrepo, Marcos I; Orihuela, Carlos J

2016-05-01

Streptococcus pneumoniae (the pneumococcus) is capable of invading the heart. Herein we observed that pneumococcal invasion of the myocardium occurred soon after development of bacteremia and was continuous thereafter. Using immunofluorescence microscopy (IFM), we observed that S. pneumoniae replication within the heart preceded visual signs of tissue damage in cardiac tissue sections stained with hematoxylin and eosin. Different S. pneumoniae strains caused distinct cardiac pathologies: strain TIGR4, a serotype 4 isolate, caused discrete pneumococcus-filled microscopic lesions (microlesions), whereas strain D39, a serotype 2 isolate, was, in most instances, detectable only using IFM and was associated with foci of cardiomyocyte hydropic degeneration and immune cell infiltration. Both strains efficiently invaded the myocardium, but cardiac damage was entirely dependent on the pore-forming toxin pneumolysin only for D39. Early microlesions caused by TIGR4 and microlesions formed by a TIGR4 pneumolysin-deficient mutant were infiltrated with CD11b(+) and Ly6G-positive neutrophils and CD11b(+) and F4/80-positive (F4/80(+)) macrophages. We subsequently demonstrated that macrophages in TIGR4-infected hearts died as a result of pneumolysin-induced necroptosis. The effector of necroptosis, phosphorylated mixed-lineage kinase domain-like protein (MLKL), was detected in CD11b(+) and F4/80(+) cells associated with microlesions. Likewise, treatment of infected mice and THP-1 macrophages in vitro with the receptor-interacting protein 1 kinase (RIP1) inhibitor necrostatin-5 promoted the formation of purulent microlesions and blocked cell death, respectively. We conclude that pneumococci that have invaded the myocardium are an important cause of cardiac damage, pneumolysin contributes to cardiac damage in a bacterial strain-specific manner, and pneumolysin kills infiltrated macrophages via necroptosis, which alters the immune response. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Infiltrated Macrophages Die of Pneumolysin-Mediated Necroptosis following Pneumococcal Myocardial Invasion

PubMed Central

Gilley, Ryan P.; González-Juarbe, Norberto; Shenoy, Anukul T.; Reyes, Luis F.; Dube, Peter H.; Restrepo, Marcos I.

2016-01-01

Streptococcus pneumoniae (the pneumococcus) is capable of invading the heart. Herein we observed that pneumococcal invasion of the myocardium occurred soon after development of bacteremia and was continuous thereafter. Using immunofluorescence microscopy (IFM), we observed that S. pneumoniae replication within the heart preceded visual signs of tissue damage in cardiac tissue sections stained with hematoxylin and eosin. Different S. pneumoniae strains caused distinct cardiac pathologies: strain TIGR4, a serotype 4 isolate, caused discrete pneumococcus-filled microscopic lesions (microlesions), whereas strain D39, a serotype 2 isolate, was, in most instances, detectable only using IFM and was associated with foci of cardiomyocyte hydropic degeneration and immune cell infiltration. Both strains efficiently invaded the myocardium, but cardiac damage was entirely dependent on the pore-forming toxin pneumolysin only for D39. Early microlesions caused by TIGR4 and microlesions formed by a TIGR4 pneumolysin-deficient mutant were infiltrated with CD11b+ and Ly6G-positive neutrophils and CD11b+ and F4/80-positive (F4/80+) macrophages. We subsequently demonstrated that macrophages in TIGR4-infected hearts died as a result of pneumolysin-induced necroptosis. The effector of necroptosis, phosphorylated mixed-lineage kinase domain-like protein (MLKL), was detected in CD11b+ and F4/80+ cells associated with microlesions. Likewise, treatment of infected mice and THP-1 macrophages in vitro with the receptor-interacting protein 1 kinase (RIP1) inhibitor necrostatin-5 promoted the formation of purulent microlesions and blocked cell death, respectively. We conclude that pneumococci that have invaded the myocardium are an important cause of cardiac damage, pneumolysin contributes to cardiac damage in a bacterial strain-specific manner, and pneumolysin kills infiltrated macrophages via necroptosis, which alters the immune response. PMID:26930705

Infections caused by Moraxella, Moraxella urethralis, Moraxella-like groups M-5 and M-6, and Kingella kingae in the United States, 1953-1980.

PubMed

Graham, D R; Band, J D; Thornsberry, C; Hollis, D G; Weaver, R E

1990-01-01

From 1953 to 1980 the Centers for Disease Control received 933 isolates of bacteria belonging to species of the genus Moraxella, Moraxella-like Moraxella urethralis, now renamed Oligella urethralis, unnamed groups M-5 and M-6, and Kingella kingae. Ordinarily sterile sites were the source of 233 isolates. Moraxella nonliquefaciens, the most common isolate (356 strains), was recovered from upper respiratory or ocular sites in 208 (58%) of the cases. Moraxella osloensis was next most common (199 strains) but was the most frequent blood isolate (44 cases). K. kingae appeared especially invasive, with 58 of 78 isolates from blood, bone, or joint. Of the K. kingae strains, 75% were recovered from children under 6 years, compared with 23% of the other strains from that age group (P less than .01). Of the 74 isolates of group M-5, 53 were from wounds caused by dog bites; no other organism in this series was recovered from such wounds. Sixteen of the 28 M. urethralis isolates were from urine. Cases occurred as single infections, with no evidence of clusters. Of patients with infection of ordinarily sterile sites, 9.3% died; only bacteremia, meningitis, and empyema caused fatalities. Most referring laboratories (98%) had not identified the organisms to species, and only 30% had identified them to correct genus. Susceptibility testing by broth dilution revealed low MICs of penicillin (mean, 0.3; 64% less than 1 micrograms/mL). Moraxella, M. urethralis, M-5, M-6, and Kingella are important but frequently misidentified pathogens for humans; penicillin appears to be the treatment of choice.

Pediatric invasive Haemophilus influenzae infections in Israel in the era of Haemophilus influenzae type b vaccine: a nationwide prospective study.

PubMed

Bamberger, Ellen E; Ben-Shimol, Shalom; Abu Raya, Bahaa; Katz, Amit; Givon-Lavi, Noga; Dagan, Ron; Srugo, Isaac

2014-05-01

The conjugated Haemophilus influenzae (Hi) type b vaccine caused a marked decrease in invasive Hi disease rates. Nonencapsulated Hi infection now constitutes most invasive Hi morbidity and mortality. This study examines invasive Hi infection incidence in Israel in the postvaccine era years, 2003-2012, and characterizes the epidemiology, clinical diagnosis and case fatality rates of invasive Hi disease in children <15 years of age. An ongoing, nationwide prospective surveillance program for invasive Hi infections in Israel. Epidemiologic and clinical data were collected. Diagnoses were classified as meningitis, pneumonia, bacteremia/sepsis and other clinical foci. Overall, 389 cases of invasive Hi infections were identified; 242 (62%) nontypable Hi (NTHi), 103 (26%) Hi type b (Hib) and 41 (11%) encapsulated non-b Hi (enbHi). Children <1 year of age accounted for 51% of the overall disease. Invasive Hi disease incidence in children <15 years of age was stable with a mean annual incidence (per 100,000) of 2.0 ± 0.4. The highest incidence of invasive Hi infections was among infants <1 year with rates of 6.2, 4.9, 1.6 and 12.7 for NTHi, Hib, enbHi and total Hi, respectively. The clinical diagnoses of NTHi and enbHi were similar, but differed from Hib with the former presenting mostly as isolated sepsis/bacteremia and the latter primarily as meningitis. Among children with invasive Hib infection, 40% were classified as vaccine failure. In the post-Hib vaccination era, invasive Hi morbidity and mortality are largely attributed to NTHi sepsis. Still, with the changing epidemiology of invasive Hi, continued surveillance of all Hi strains is justified.

Reproductive isolation and the expansion of an invasive hybrid swarm

USGS Publications Warehouse

Blum, Michael J.; Walters, David M.; Burkhead, Noel M.; Freeman, Byron J.; Porter, Brady A.

2010-01-01

Biological invasions involving hybridization proceed according to prezygotic and postzygotic reproductive isolating mechanisms. Yet few comparisons of reproductive isolation have been carried out to understand how different mechanisms prevent or promote invasions involving hybridization. Here we present a study of prezygotic and postzygotic isolation between non-native red shiner (Cyprinella lutrensis) and native blacktail shiner (C. venusta stigmatura) from the Coosa River basin (USA) to better understand the formation and expansion of invasive hybrid swarms. We conducted spawning trials to measure mating preferences and raised broods from crosses to assay hybrid viability through early juvenile development. Females of both species were more responsive to conspecific mates, although blacktail shiner females responded more often to heterospecific mates than did red shiner females. Fecundity of red shiner females was also higher than blacktail shiner females. Heterospecific crosses resulted in lower fertilization and egg hatching rates, but we found no other evidence of inviability. Rather, we found comparatively low larval mortality of F1 hybrids, which is suggestive of heterosis. These findings support prior inferences of assortative mating from genetic descriptions of hybridization, and that the invasion in the Coosa River is likely proceeding due to interspecific competition and intrinsic hybrid viability.

Development and characterization of 17 polymorphic microsatellite loci in the faucet snail, Bithynia tentaculata (Gastroposa: Caenogastropoda; Bithyniidae)

USGS Publications Warehouse

Henningsen, Justin P.; Lance, Stacey L.; Jones, Kenneth L.; Hagen, Chris; Laurila, Joshua; Cole, Rebecca A.; Perez, Kathryn E.

2010-01-01

Bithynia tentaculata (Linnaeus, 1758), a snail native to Europe, was introduced into the US Great Lakes in the 1870's and has spread to rivers throughout the Northeastern US and Upper Mississippi River (UMR). Trematode parasites, for which B. tentaculata is a host, have also been introduced and are causing widespread waterfowl mortality in the UMR. Waterfowl mortality is caused by ingestion of trematode-infected B. tentaculata or insects infected with parasites released from the snails. We isolated and characterized 17 microsatellite loci from the invasive faucet snail, B. tentaculata (Gastropoda: Caenogastropoda: Bithyniidae). Loci were screened in 24 individuals of B. tentaculata. The number of alleles per locus ranged from 2 to 6, observed heterozygosity ranged from 0.050 to 0.783, and the probability of identity values ranged from 0.10 to 0.91. These new loci provide tools for examining the origin and spread of invasive populations in the US and management activities to prevent waterfowl mortality.

Group A Streptococcus produce pilus-like structures containing protective antigens and Lancefield T antigens.

PubMed

Mora, Marirosa; Bensi, Giuliano; Capo, Sabrina; Falugi, Fabiana; Zingaretti, Chiara; Manetti, Andrea G O; Maggi, Tiziana; Taddei, Anna Rita; Grandi, Guido; Telford, John L

2005-10-25

Although pili have long been recognized in Gram-negative pathogens as important virulence factors involved in adhesion and invasion, very little is known about extended surface organelles in Gram-positive pathogens. Here we report that Group A Streptococcus (GAS), a Gram-positive human-specific pathogen that causes pharyngitis, impetigo, invasive disease, necrotizing fasciitis, and autoimmune sequelae has long, surface-exposed, pilus-like structures composed of members of a family of extracellular matrix-binding proteins. We describe four variant pili and show that each is recognized by a specific serum of the Lancefield T-typing system, which has been used for over five decades to characterize GAS isolates. Furthermore, we show that immunization of mice with a combination of recombinant pilus proteins confers protection against mucosal challenge with virulent GAS bacteria. The data indicate that induction of a protective immune response against these structures may be a useful strategy for development of a vaccine against disease caused by GAS infection.

Proteomic characterization of the subpellicular cytoskeleton of Toxoplasma gondii tachyzoites.

PubMed

Gómez de León, Carmen T; Díaz Martín, Rubén Darío; Mendoza Hernández, Guillermo; González Pozos, Sirenia; Ambrosio, Javier R; Mondragón Flores, Ricardo

2014-12-05

Toxoplasma, the causative agent of toxoplasmosis in animals and humans, has a subpellicular cytoskeleton that is involved in motility, cell shape and invasion. Knowledge of components of the cytoskeleton is necessary to understand the invasion mechanisms as well as for the identification of possible therapeutic targets. To date, most cytoskeletal components of Toxoplasma remain unidentified due mainly to the lack of reproducible methods for their isolation. Based on the successful isolation of the cytoskeleton, it was possible to report for the first time, the proteomic characterization of the subpellicular cytoskeleton of Toxoplasma formed by 95 cytoskeletal proteins through proteomic analysis by tandem mass spectrometry of one dimension SDS PAGE. By bioinformatic analysis of the data, proteins were classified as: 18 conventional cytoskeletal proteins; 10 inner membrane complex proteins, including 7 with alveolin repeats; 5 new proteins with alveolin like repeats; 37 proteins associated with other organelles and 25 novel proteins of unknown function. One of the alveolin like proteins not previously described in Toxoplasma named TgArticulin was partially characterized with a specific monoclonal antibody. Presence of TgArticulin was exclusively associated with the cytoskeleton fraction with a cortical distribution. Functions for the several molecules identified are proposed. This manuscript describes, for the first time, the proteome of the subpellicular cytoskeleton of Toxoplasma gondii. The importance of this study is related to the role of the cytoskeleton in the highly invasive capability of a parasite that causes abortion, blindness, and death by encephalitis in immunocompromised patients. Proteomic characterization of the cytoskeleton of T. gondii tachyzoites was possible by the development of a successful procedure for the isolation of the subpellicular cytoskeleton. Knowledge of the composition of the cytoskeleton of Toxoplasma is fundamental for the understanding of the motility and host cell invasion mechanisms, and for the future design and development of toxoplasmicidal drugs with effects against specific components of the cytoskeleton of this parasite that are absent in mammal host cells. Copyright © 2014 Elsevier B.V. All rights reserved.

Pathogenic Phenotype and Genotype of Pseudomonas aeruginosa Isolates from Spontaneous Canine Ocular Infections

PubMed Central

Ledbetter, Eric C.; Mun, James J.; Kowbel, David; Fleiszig, Suzanne M. J.

2009-01-01

Purpose This study was designed to determine whether the ability to adversely affect corneal epithelial cell health is a factor common to Pseudomonas aeruginosa keratitis strains and to assess the prevalence of each pathogenic phenotype and genotype in a canine model of naturally-acquired P. aeruginosa ocular infection. Methods P. aeruginosa ocular isolates were collected by sampling 100 dogs without disease (six isolates collected) and by sampling dogs with conjunctivitis (two isolates), endophthalmitis (one isolate), active keratitis (12 isolates), and resolved P. aeruginosa keratitis (four isolates). Phenotype was determined in vitro by quantifying corneal epithelial cell invasion by gentamicin survival assays, and cytotoxic activity by Trypan blue exclusion assays. Genotyping was performed for genes encoding the type III secreted effectors. Results The ratio of invasive to cytotoxic strains with 95% confidence intervals (CI) was 0.83 (CI, 0.42– 0.99) for conjunctival microflora isolates, 0.80 (CI, 0.54 – 0.94) for ocular infection isolates, and 1.0 (CI, 0.45–1.0) for strains isolated post-resolution of keratitis. Among ocular infection isolates, invasive and cytotoxic strains were significantly (P ≤ 0.02) associated with older and younger dogs, respectively. Visible adverse effects on epithelial cells were significantly (P ≤ 0.03) more frequent for keratitis strains (6/12) than other strains (1/13), but only three of these keratitis strains and the single non-keratitis strain possessed ExoU. Conclusions Invasive strains predominated in the dogs of this study. Only keratitis strains had visible adverse effects on epithelial cells without overt cytotoxicity, suggesting virulence strategies affecting live corneal epithelial cell health are selected for among keratitis strains. PMID:18836164

Serotype changes in adult invasive pneumococcal infections in Portugal did not reduce the high fraction of potentially vaccine preventable infections.

PubMed

Horácio, Andreia N; Diamantino-Miranda, Jorge; Aguiar, Sandra I; Ramirez, Mário; Melo-Cristino, José

2012-01-05

We determined the serotype and antimicrobial susceptibility of 1100 isolates responsible for adult invasive pneumococcal infections (IPD) in Portugal between 2006 and 2008. Serotypes 3 (13%), 1 (12%), 7F (11%), 19A (10%) and 14 (7%) were the most frequent causes of IPD and the two later serotypes accounted for the majority of erythromycin and penicillin nonsusceptible isolates. Serotype 1 was associated with younger adults whereas serotype 3 was associated with older adults. Despite the availability of the 23-valent polysaccharide vaccine (PPV23) in Portugal since 1996, the proportion of PPV23 preventable IPD remained stable and above 80%. Comparing with previous data from Portugal, we showed a continued decline of the serotypes included in the 7-valent conjugate vaccine (PCV7) in adult IPD and a rise of serotypes included in the 13-valent conjugate vaccine, increasing its potential coverage of adult IPD to 70% in 2008. Penicillin non-susceptibility remained stable (17%) whereas erythromycin resistance (18%) has continued to rise in the post-PCV7 years. Copyright © 2011 Elsevier Ltd. All rights reserved.

Large scale genomic analysis shows no evidence for pathogen adaptation between the blood and cerebrospinal fluid niches during bacterial meningitis

PubMed Central

Lees, John A.; Kremer, Philip H. C.; Manso, Ana S.; Croucher, Nicholas J.; Ferwerda, Bart; Serón, Mercedes Valls; Oggioni, Marco R.; Parkhill, Julian; Brouwer, Matthijs C.; van der Ende, Arie; van de Beek, Diederik

2017-01-01

Recent studies have provided evidence for rapid pathogen genome diversification, some of which could potentially affect the course of disease. We have previously described such variation seen between isolates infecting the blood and cerebrospinal fluid (CSF) of a single patient during a case of bacterial meningitis. Here, we performed whole-genome sequencing of paired isolates from the blood and CSF of 869 meningitis patients to determine whether such variation frequently occurs between these two niches in cases of bacterial meningitis. Using a combination of reference-free variant calling approaches, we show that no genetic adaptation occurs in either invaded niche during bacterial meningitis for two major pathogen species, Streptococcus pneumoniae and Neisseria meningitidis. This study therefore shows that the bacteria capable of causing meningitis are already able to do this upon entering the blood, and no further sequence change is necessary to cross the blood–brain barrier. Our findings place the focus back on bacterial evolution between nasopharyngeal carriage and invasion, or diversity of the host, as likely mechanisms for determining invasiveness. PMID:28348877

Invasive Saccharomyces cerevisiae infection: a friend turning foe?

PubMed

Pillai, Unnikrishnan; Devasahayam, Joe; Kurup, Aparna Narayana; Lacasse, Alexandre

2014-11-01

We report a very rare case of acute pyelonephritis in a 51-year-old female with a history of chronic kidney disease (CKD) and diabetes caused by a normally benign and a well-known human commensal organism, Saccharomyces cerevisiae that is very often prescribed as a probiotic in modern medical practice. The causal role of S. cerevisiae was confirmed by its isolation in blood, urine, stool as well as vaginal swabs thus proving its virulent nature in suitable situations.

The patterns of colonization and antifungal susceptibility of Candida, isolated from preterm neonates in Khorramabad, South West of Iran.

PubMed

Kooshki, P; Rezaei-Matehkolaei, A; Mahmoudabadi, A Z

2018-06-01

Usually, 7-20% of preterm neonates colonized by Candida species present invasive candidiasis. Candida albicans, and several non-albicans species cause invasive infection with C. albicans being the most dominant agent. In the last two decades, infection due to non-albicans have been increased dramatically due to their low sensitivity to antifungal drugs such as fluconazole. The aim of present study was to evaluate Candida colonization pattern and antifungal susceptibility among preterm neonates from Khorramabad, South west of Iran. Samples were collected from 80 preterm neonates, cultured on CHROMagar Candida and incubated at 37°C. All recovered isolates were primarily screened based on classical methods and identified by PCR-RFLP targeting the ITS-rDNA regions. Antifungal susceptibility testing of all isolates was performed according to the CLSI method against amphotericin B, caspofungin, itraconazole, fluconazole and voriconazole. Totally 23 isolates of Candida species were recovered from 20 patients (female: male, 50:50) including, C. albicans (18), C. parapsilosis (2) and C. glabrata (1). Furthermore, the blood cultures from two patients were yielded C. albicans and C. parapsilosis so that patient with C. albicans died after five days. Generally, in this study, 9 (39.1%) isolates were resistant to amphotericin B including; 7 (30.4%) C. albicans and 2 (8.7%) C. parapsilosis. In addition, 2 (8.7%) and 4 (17.4%) isolates were also resistant to itraconazole and caspofungin, respectively. In conclusion, Candida colonization among preterm neonates is still an important issue in hospitals. In addition, in spite of a significant amphotericin B resistant Candida, voriconazole, fluconazole, and itraconazole are valuable antifungals, due to fully sensitivity to Candida. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Comparative analysis of the virulence characteristics of epidemic methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from Chinese children: ST59 MRSA highly expresses core gene-encoded toxin.

PubMed

Li, Shipeng; Sun, Jing; Zhang, Jianzhong; Li, Xiangmei; Tao, Xiaoxia; Wang, Lijuan; Sun, Mingjiao; Liu, Yingchao; Li, Juan; Qiao, Yanhong; Yu, Sangjie; Yao, Kaihu; Yang, Yonghong; Shen, Xuzhuang

2014-02-01

This study aims to investigate the prevalence of a novel cell wall-anchored protein gene, sasX, and to obtain information on the genetic basis for the pathogenic potential of the MRSA strains isolated from Chinese children. The molecular and virulence characteristics of the clinical strains were analyzed. Twenty-two sequence types (STs) were obtained, with six epidemic clones ST59, ST239, ST1, ST910, ST88, and ST338 accounting for 35.8, 22, 6.6, 6.6, 5.3, and 4.1% respectively. The expression levels of hla, psmα, and RNAIII were higher in ST59 than in other STs (p < 0.05). The sasX gene was detected in 26 (10.7%) MRSA isolates. ST239-MRSA-SCCmecIII-t037 (61.5%) was the predominant sasX-positive MRSA clone. The expressions of PSMα and RNAIII were higher in sasX-positive ST239 isolates than in sasX-negative ST239 ones (p < 0.01). Notably, the percentage of invasive infection in infections caused by sasX-positive ST239 MRSA was higher than that by sasX-negative ST239 MRSA (p = 0.008). This study indicated that ST59 was the predominant clone in the MRSA isolates obtained from Chinese children and might have stronger pathogenic potential. The prevalence of the sasX gene in the MRSA isolates from children was relatively low. Furthermore, the sasX gene might be related to the expressions of PSMα and RNAIII and infection invasiveness. © 2013 APMIS Published by John Wiley & Sons Ltd.

Accessory genetic content in Campylobacter jejuni ST21CC isolates from feces and blood.

PubMed

Skarp, C P A; Akinrinade, O; Kaden, R; Johansson, C; Rautelin, H

2017-06-01

Campylobacter jejuni is an important foodborne pathogen and the most commonly reported bacterial cause of gastroenteritis. C. jejuni is occasionally found in blood, although mechanisms important for invasiveness have remained unclear. C. jejuni is divided into many different lineages, of which the ST21 clonal complex (CC) is widely distributed. Here, we performed comparative genomic and in vitro analyses on 17C. jejuni ST21CC strains derived from human blood and feces in order to identify features associated with isolation site. The ST21CC lineage is divided into two large groups; centered around ST-21 and ST-50. Our clinical strains, typed as ST-50, showed further microevolution into two distinct clusters. These clusters were distinguished by major differences in their capsule loci and the distribution of accessory genetic content, including C. jejuni integrated elements (CJIEs) and plasmids. Accessory genetic content was more common among fecal than blood strains, whereas blood strains contained a hybrid capsule locus which partially consisted of C. jejuni subsp. doylei-like content. In vitro infection assays with human colon cell lines did not show significant differences in adherence and invasion between the blood and fecal strains. Our results showed that CJIEs and plasmid derived genetic material were less common among blood isolates than fecal isolates; in contrast, hybrid capsule loci, especially those containing C. jejuni subsp. doylei-like gene content, were found among many isolates derived from blood. The role of these findings requires more detailed investigation. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Clonal Spread of Levofloxacin-Resistant Streptococcus pneumoniae Invasive Isolates in Madrid, Spain, 2007 to 2009▿

PubMed Central

Rodríguez-Avial, Iciar; Ramos, Belén; Ríos, Esther; Cercenado, Emilia; Ordobás, María; Sanz, Juan Carlos

2011-01-01

Among 1,349 Streptococcus pneumoniae invasive isolates, 45 (3.3%) were levofloxacin resistant. Serotype distribution was as follows: 8 (n = 32 isolates), 19A (n = 4 isolates), 7F (n = 3 isolates), 9V (n = 2 isolates), 10A (n = 1 isolate), 19F (n = 1 isolate), 6B (n = 1 isolate), and nontypeable (n = 1 isolate). Levofloxacin-resistant isolates had dual mutations in the gyrA and parC genes. Serotype 8 strains corresponded to a capsular switching of the Sweden15A-25 clone. Levofloxacin resistance was also detected among multiresistant (ST27619A, Spain9V-ST156, ST8819F, and ST15426B) and among usually antibiotic-susceptible (Netherlands7F-ST191, ST120119A, and ST263910A) clones. PMID:21383091

Serotypes, antimicrobial susceptibility, and beta-lactam resistance mechanisms of clinical Haemophilus influenzae isolates from Bulgaria in a pre-vaccination period.

PubMed

Setchanova, Lena Petrova; Kostyanev, Tomislav; Markovska, Rumyana; Miloshev, George; Mitov, Ivan Gergov

2013-02-01

To determine the serotypes, antimicrobial susceptibility, and beta-lactam resistance mechanisms of Haemophilus influenzae strains isolated from invasive and respiratory tract infections (RTIs) prior to the introduction of Haemophilus influenzae type b (Hib) vaccination in Bulgaria. A total of 259 isolates were serotyped by polymerase chain reaction. Susceptibility to antibiotics and beta-lactamase production were determined, and DNA sequencing of the ftsI gene was performed for ampicillin non-susceptible strains. The invasive H. influenzae infections in children were mainly due to serotype b (94.5% in meningitis and 88.9% in other invasive cases). Non-typeable strains (97.4%) were the most frequently found H. influenzae strains in RTIs both in children and adults. Non-susceptibility to ampicillin occurred in 22% of all strains. Ceftriaxone and levofloxacin were the most active agents tested. Ampicillin resistance occurred in 34.4% of invasive strains, and beta-lactamase production was the only mechanism found. Among respiratory tract isolates, ampicillin non-susceptible strains (18%) were classified into the following groups: beta-lactamase-positive, ampicillin-resistant (BLPAR) strains (7.2%); beta-lactamase-negative, ampicillin-non-susceptible (BLNAR) strains (8.2%); and beta- lactamase-positive, amoxicillin-clavulanate-resistant (BLPACR) strains (2.6%). Among 21 BLNAR and BLPACR strains there were 9 different patterns of multiple-amino acid substitutions in penicillin-binding protein 3. Of these, most isolates (81.0%) belonged to group II, defined by the Asn526Lys substitution. Beta-lactamase production was more common among invasive strains than in respiratory isolates. BLNAR and BLPACR H. influenzae were found only among respiratory tract isolates.

Human Streptococcus agalactiae strains in aquatic mammals and fish

PubMed Central

2013-01-01

Background In humans, Streptococcus agalactiae or group B streptococcus (GBS) is a frequent coloniser of the rectovaginal tract, a major cause of neonatal infectious disease and an emerging cause of disease in non-pregnant adults. In addition, Streptococcus agalactiae causes invasive disease in fish, compromising food security and posing a zoonotic hazard. We studied the molecular epidemiology of S. agalactiae in fish and other aquatic species to assess potential for pathogen transmission between aquatic species and humans. Methods Isolates from fish (n = 26), seals (n = 6), a dolphin and a frog were characterized by pulsed-field gel electrophoresis, multilocus sequence typing and standardized 3-set genotyping, i.e. molecular serotyping and profiling of surface protein genes and mobile genetic elements. Results Four subpopulations of S. agalactiae were identified among aquatic isolates. Sequence type (ST) 283 serotype III-4 and its novel single locus variant ST491 were detected in fish from Southeast Asia and shared a 3-set genotype identical to that of an emerging ST283 clone associated with invasive disease of adult humans in Asia. The human pathogenic strain ST7 serotype Ia was also detected in fish from Asia. ST23 serotype Ia, a subpopulation that is normally associated with human carriage, was found in all grey seals, suggesting that human effluent may contribute to microbial pollution of surface water and exposure of sea mammals to human pathogens. The final subpopulation consisted of non-haemolytic ST260 and ST261 serotype Ib isolates, which belong to a fish-associated clonal complex that has never been reported from humans. Conclusions The apparent association of the four subpopulations of S. agalactiae with specific groups of host species suggests that some strains of aquatic S. agalactiae may present a zoonotic or anthroponotic hazard. Furthermore, it provides a rational framework for exploration of pathogenesis and host-associated genome content of S. agalactiae strains. PMID:23419028

Adhesin genes and serum resistance in Haemophilus influenzae type f isolates

PubMed Central

Nelson, Kevin L.; Nguyen, Victoria; Burnham, Carey-Ann D.; Clarridge, Jill E.; Qin, Xuan; Smith, Arnold L.

2013-01-01

The incidence of invasive infections due to Haemophilus influenzae has decreased significantly in developed countries with high rates of vaccination against H. influenzae serotype b (Hib). This vaccine provides no protection against H. influenzae serotype f (Hif), typically associated with invasive infections in adults with chronic disease and/or immunodeficiency, and rarely in otherwise healthy adults and children. The specific properties of Hif associated with virulence remain largely uncharacterized. A panel of 26 Hif strains consisting of both invasive disease-associated and mucosal surface non-invasive disease-associated isolates was surveyed by DNA fingerprinting, biotyping and PCR detection of hmw1, hmw2, hsf, the hif fimbrial locus and the lipo-oligosaccharide (LOS) biosynthetic island, and assessment of β-lactamase expression and determination of resistance to the bactericidal activity of normal adult human serum. Repetitive sequence-based PCR fingerprinting differentiated the 26 strains into three clusters, with the majority of isolates (22/26, 84.6 %) clustered into a single indistinguishable group. Most isolates (24/26, 92.3 %) were of biotype I and two isolates produced β-lactamase with detection of a conjugative plasmid, and the isolates displayed a range of resistances to the bactericidal activity of human serum. All 26 isolates carried the adhesin hsf, 21 carried a partial hif fimbrial operon and 4 had the adhesin genes hmw1/2. A LOS biosynthetic island was detected in 20 isolates consisting of the genes lic2BC. It was concluded that Hif has many recognized virulence properties and comprises a relatively homogeneous group independent of the anatomical source from which it was isolated. PMID:23242639

Differences in SpeB protease activity among group A streptococci associated with superficial, invasive, and autoimmune disease

PubMed Central

Walwyn, Odaelys L.; Tanz, Robert R.; Shulman, Stanford T.; Kabat, William

2017-01-01

The secreted cysteine proteinase SpeB is an important virulence factor of group A streptococci (GAS), whereby SpeB activity varies widely among strains. To establish the degree to which SpeB activity correlates with disease, GAS organisms were recovered from patients with pharyngitis, impetigo, invasive disease or acute rheumatic fever (ARF), and selected for analysis using rigorous sampling criteria; >300 GAS isolates were tested for SpeB activity by casein digestion assays, and each GAS isolate was scored as a SpeB-producer or non-producer. Highly significant statistical differences (p < 0.01) in SpeB production are observed between GAS recovered from patients with ARF (41.5% SpeB-non-producers) compared to pharyngitis (20.5%), invasive disease (16.7%), and impetigo (5.5%). SpeB activity differences between pharyngitis and impetigo isolates are also significant, whereas pharyngitis versus invasive isolates show no significant difference. The disproportionately greater number of SpeB-non-producers among ARF-associated isolates may indicate an altered transcriptional program for many rheumatogenic strains and/or a protective role for SpeB in GAS-triggered autoimmunity. PMID:28545045

Do native parasitic plants cause more damage to exotic invasive hosts than native non-invasive hosts? An implication for biocontrol.

PubMed

Li, Junmin; Jin, Zexin; Song, Wenjing

2012-01-01

Field studies have shown that native, parasitic plants grow vigorously on invasive plants and can cause more damage to invasive plants than native plants. However, no empirical test has been conducted and the mechanism is still unknown. We conducted a completely randomized greenhouse experiment using 3 congeneric pairs of exotic, invasive and native, non-invasive herbaceous plant species to quantify the damage caused by parasitic plants to hosts and its correlation with the hosts' growth rate and resource use efficiency. The biomass of the parasitic plants on exotic, invasive hosts was significantly higher than on congeneric native, non-invasive hosts. Parasites caused more damage to exotic, invasive hosts than to congeneric, native, non-invasive hosts. The damage caused by parasites to hosts was significantly positively correlated with the biomass of parasitic plants. The damage of parasites to hosts was significantly positively correlated with the relative growth rate and the resource use efficiency of its host plants. It may be the mechanism by which parasitic plants grow more vigorously on invasive hosts and cause more damage to exotic, invasive hosts than to native, non-invasive hosts. These results suggest a potential biological control effect of native, parasitic plants on invasive species by reducing the dominance of invasive species in the invaded community.

Feral Cat Globetrotters: genetic traces of historical human-mediated dispersal.

PubMed

Koch, Katrin; Algar, Dave; Schwenk, Klaus

2016-08-01

Endemic species on islands are highly susceptible to local extinction, in particular if they are exposed to invasive species. Invasive predators, such as feral cats, have been introduced to islands around the world, causing major losses in local biodiversity. In order to control and manage invasive species successfully, information about source populations and level of gene flow is essential. Here, we investigate the origin of feral cats of Hawaiian and Australian islands to verify their European ancestry and a potential pattern of isolation by distance. We analyzed the genetic structure and diversity of feral cats from eleven islands as well as samples from Malaysia and Europe using mitochondrial DNA (ND5 and ND6 regions) and microsatellite DNA data. Our results suggest an overall European origin of Hawaiian cats with no pattern of isolation by distance between Australian, Malaysian, and Hawaiian populations. Instead, we found low levels of genetic differentiation between samples from Tasman Island, Lana'i, Kaho'olawe, Cocos (Keeling) Island, and Asia. As these populations are separated by up to 10,000 kilometers, we assume an extensive passive dispersal event along global maritime trade routes in the beginning of the 19th century, connecting Australian, Asian, and Hawaiian islands. Thus, islands populations, which are characterized by low levels of current gene flow, represent valuable sources of information on historical, human-mediated global dispersal patterns of feral cats.

Patterns of Adherence of Helicobacter pylori Clinical Isolates to Epithelial Cells, and its Association with Disease and with Virulence Factors.

PubMed

Vázquez-Jiménez, Flor Elizabeth; Torres, Javier; Flores-Luna, Lourdes; Cerezo, Silvia Giono; Camorlinga-Ponce, Margarita

2016-02-01

Adherence to the gastric epithelium is one of the most important steps of Helicobacter pylori to remain and cause disease. The aim of this study was to analyze whether H. pylori isolates from patients with different gastroduodenal diseases present differences in the pattern of adherence to gastric epithelial cells (AGS), in the ability to induce IL-8, and in the presence of virulence genes. We tested 75 H. pylori strains isolated from nonatrophic gastritis, gastric cancer, and duodenal ulcer patients. The adhesion pattern and IL-8 induction were determined in AGS cells, and invasion of AGS cells was studied using a gentamicin protection assay. The IL-8 levels induced were determined by ELISA. Helicobacter pylori strains presented diffuse adherence (DA) and localized (LA) adherence patterns, similar to those described for enteropathogenic E. coli (EPEC), were observed in AGS cells. A DA pattern was observed in 57% and LA in 43% of the strains, and DA was more frequent in isolates from patients with gastric cancer (p = 0.044). Strains with a LA pattern induced higher levels of IL-8 (p = 0.042) in AGS cells. The adherence pattern was not associated with neither invasiveness nor with the presence of virulence genes. Our study shows that H. pylori strains present adherence patterns to AGS cells resembling those observed in EPEC and that these patterns may be associated with disease and with activity on AGS cells. © 2015 John Wiley & Sons Ltd.

Prevalence of Streptococcus suis Genotypes in Wild Boars of Northwestern Germany▿

PubMed Central

Baums, Christoph G.; Verkühlen, Gerd Josef; Rehm, Thomas; Silva, Luciana M. G.; Beyerbach, Martin; Pohlmeyer, Klaus; Valentin-Weigand, Peter

2007-01-01

Invasive serotype 2 (cps2+) strains of Streptococcus suis cause meningitis in pigs and humans. Four case reports of S. suis meningitis in hunters suggest transmission of S. suis through the butchering of wild boars. Therefore, the objective of this study was to investigate the prevalence of potentially human-pathogenic S. suis strains in wild boars. S. suis was isolated from 92% of all tested tonsils (n = 200) from wild boars. A total of 244 S. suis isolates were genotyped using PCR assays for the detection of serotype-specific genes, the hemolysin gene sly, and the virulence-associated genes mrp and epf. The prevalence of the cps2+ genotype among strains from wild boars was comparable to that of control strains from domestic pig carriers. Ninety-five percent of the cps2+ wild boar strains were positive for mrp, sly, and epf*, the large variant of epf. Interestingly, epf* was significantly more frequently detected in cps2+ strains from wild boars than in those from domestic pigs; epf* is also typically found in European S. suis isolates from humans, including a meningitis isolate from a German hunter. These results suggest that at least 10% of wild boars in Northwestern Germany carry S. suis strains that are potentially virulent in humans. Additional amplified fragment length polymorphism analysis supported this hypothesis, since homogeneous clustering of the epf* mrp+ sly+ cps2+ strains from wild boars with invasive human and porcine strains was observed. PMID:17085699

The Correlation Between Candida Colonization of Distinct Body Sites and Invasive Candidiasis in Emergency Intensive Care Units: Statistical and Molecular Biological Analysis.

PubMed

Li, Zhen; Jiang, Cen; Dong, Danfeng; Zhang, Lihua; Tian, Yuan; Ni, Qi; Mao, Enqiang; Peng, Yibing

2016-08-01

Both statistical and molecular biological methods were used to evaluate the association between Candida colonization of different body sites and invasive candidiasis (IC) and analyse the potential infection sources of IC. Candida surveillance cultures from the urine, sputum, rectum and skin were performed on patients admitted to an emergency intensive care units (EICU) of a tertiary care hospital in Shanghai, China, from February 2014 to January 2015. Specimens were collected once a week at admission and thereafter. The patients' clinical data were collected, and Candida isolates were genotyped using polymorphic microsatellite markers. A total of 111 patients were enrolled. Patients with positive urine (23.3 vs. 2.5 %, p = 0.001) and rectal swab (13.6 vs. 0 %, p = 0.010) cultures were more likely to develop IC. However, the risk for IC was not significantly different among patients with and without respiratory (10.0 vs. 5.8 %, p = 0.503) and skin (33.3 vs. 6.5 %, p = 0.056) colonization. Gene microevolution frequently occurred at rectal swab and urine sites, and IC with possible source of infection was caused by rectal isolates (2/7), urine isolates (4/7) and sputum isolate (1/7).The colonization of gut and urinary tract maybe more relevant indicators of IC, which should be taken into consideration when selecting practical body sites for Candida surveillance cultures.

Prevalence of Streptococcus suis genotypes in wild boars of Northwestern Germany.

PubMed

Baums, Christoph G; Verkühlen, Gerd Josef; Rehm, Thomas; Silva, Luciana M G; Beyerbach, Martin; Pohlmeyer, Klaus; Valentin-Weigand, Peter

2007-02-01

Invasive serotype 2 (cps2+) strains of Streptococcus suis cause meningitis in pigs and humans. Four case reports of S. suis meningitis in hunters suggest transmission of S. suis through the butchering of wild boars. Therefore, the objective of this study was to investigate the prevalence of potentially human-pathogenic S. suis strains in wild boars. S. suis was isolated from 92% of all tested tonsils (n=200) from wild boars. A total of 244 S. suis isolates were genotyped using PCR assays for the detection of serotype-specific genes, the hemolysin gene sly, and the virulence-associated genes mrp and epf. The prevalence of the cps2+ genotype among strains from wild boars was comparable to that of control strains from domestic pig carriers. Ninety-five percent of the cps2+ wild boar strains were positive for mrp, sly, and epf*, the large variant of epf. Interestingly, epf* was significantly more frequently detected in cps2+ strains from wild boars than in those from domestic pigs; epf* is also typically found in European S. suis isolates from humans, including a meningitis isolate from a German hunter. These results suggest that at least 10% of wild boars in Northwestern Germany carry S. suis strains that are potentially virulent in humans. Additional amplified fragment length polymorphism analysis supported this hypothesis, since homogeneous clustering of the epf* mrp+ sly+ cps2+ strains from wild boars with invasive human and porcine strains was observed.

Diet Quality Scores and Prediction of All-Cause, Cardiovascular and Cancer Mortality in a Pan-European Cohort Study

PubMed Central

Lassale, Camille; Gunter, Marc J.; Romaguera, Dora; Peelen, Linda M.; Van der Schouw, Yvonne T.; Beulens, Joline W. J.; Freisling, Heinz; Muller, David C.; Ferrari, Pietro; Huybrechts, Inge; Fagherazzi, Guy; Boutron-Ruault, Marie-Christine; Affret, Aurélie; Overvad, Kim; Dahm, Christina C.; Olsen, Anja; Roswall, Nina; Tsilidis, Konstantinos K.; Katzke, Verena A.; Kühn, Tilman; Buijsse, Brian; Quirós, José-Ramón; Sánchez-Cantalejo, Emilio; Etxezarreta, Nerea; Huerta, José María; Barricarte, Aurelio; Bonet, Catalina; Khaw, Kay-Tee; Key, Timothy J.; Trichopoulou, Antonia; Bamia, Christina; Lagiou, Pagona; Palli, Domenico; Agnoli, Claudia; Tumino, Rosario; Fasanelli, Francesca; Panico, Salvatore; Bueno-de-Mesquita, H. Bas; Boer, Jolanda M. A.; Sonestedt, Emily; Nilsson, Lena Maria; Renström, Frida; Weiderpass, Elisabete; Skeie, Guri; Lund, Eiliv; Moons, Karel G. M.; Riboli, Elio; Tzoulaki, Ioanna

2016-01-01

Scores of overall diet quality have received increasing attention in relation to disease aetiology; however, their value in risk prediction has been little examined. The objective was to assess and compare the association and predictive performance of 10 diet quality scores on 10-year risk of all-cause, CVD and cancer mortality in 451,256 healthy participants to the European Prospective Investigation into Cancer and Nutrition, followed-up for a median of 12.8y. All dietary scores studied showed significant inverse associations with all outcomes. The range of HRs (95% CI) in the top vs. lowest quartile of dietary scores in a composite model including non-invasive factors (age, sex, smoking, body mass index, education, physical activity and study centre) was 0.75 (0.72–0.79) to 0.88 (0.84–0.92) for all-cause, 0.76 (0.69–0.83) to 0.84 (0.76–0.92) for CVD and 0.78 (0.73–0.83) to 0.91 (0.85–0.97) for cancer mortality. Models with dietary scores alone showed low discrimination, but composite models also including age, sex and other non-invasive factors showed good discrimination and calibration, which varied little between different diet scores examined. Mean C-statistic of full models was 0.73, 0.80 and 0.71 for all-cause, CVD and cancer mortality. Dietary scores have poor predictive performance for 10-year mortality risk when used in isolation but display good predictive ability in combination with other non-invasive common risk factors. PMID:27409582

Strain Selection for Generation of O-Antigen-Based Glycoconjugate Vaccines against Invasive Nontyphoidal Salmonella Disease

PubMed Central

Saul, Allan; MacLennan, Calman A.; Micoli, Francesca; Rondini, Simona

2015-01-01

Nontyphoidal Salmonellae, principally S. Typhimurium and S. Enteritidis, are a major cause of invasive bloodstream infections in sub-Saharan Africa with no vaccine currently available. Conjugation of lipopolysaccharide O-antigen to a carrier protein constitutes a promising vaccination strategy. Here we describe a rational process to select the most appropriate isolates of Salmonella as source of O-antigen for developing a bivalent glycoconjugate vaccine. We screened a library of 30 S. Typhimurium and 21 S. Enteritidis in order to identify the most suitable strains for large scale O-antigen production and generation of conjugate vaccines. Initial screening was based on growth characteristics, safety profile of the isolates, O-antigen production, and O-antigen characteristics in terms of molecular size, O-acetylation and glucosylation level and position, as determined by phenol sulfuric assay, NMR, HPLC-SEC and HPAEC-PAD. Three animal isolates for each serovar were identified and used to synthesize candidate glycoconjugate vaccines, using CRM197 as carrier protein. The immunogenicity of these conjugates and the functional activity of the induced antibodies was investigated by ELISA, serum bactericidal assay and flow cytometry. S. Typhimurium O-antigen showed high structural diversity, including O-acetylation of rhamnose in a Malawian invasive strain generating a specific immunodominant epitope. S. Typhimurium conjugates provoked an anti-O-antigen response primarily against the O:5 determinant. O-antigen from S. Enteritidis was structurally more homogeneous than from S. Typhimurium, and no idiosyncratic antibody responses were detected for the S. Enteritidis conjugates. Of the three initially selected isolates, two S. Typhimurium (1418 and 2189) and two S. Enteritidis (502 and 618) strains generated glycoconjugates able to induce high specific antibody levels with high breadth of serovar-specific strain coverage, and were selected for use in vaccine production. The strain selection approach described is potentially applicable to the development of glycoconjugate vaccines against other bacterial pathogens. PMID:26445460

Pleural empyema and streptococcal toxic shock syndrome due to Streptococcus pyogenes in a healthy Spanish traveler in Japan.

PubMed

Sakai, Tetsuya; Taniyama, Daisuke; Takahashi, Saeko; Nakamura, Morio; Takahashi, Takashi

2017-01-01

Group A Streptococcus (GAS, Streptococcus pyogenes ) causes invasive infections including streptococcal toxic shock syndrome (STSS) and local infections. To our knowledge, this is the first report of a case of an invasive GAS infection with pneumonia and pleural empyema (PE) followed by STSS (disseminated intravascular coagulation [DIC] and acute renal insufficiency) in a healthy male adult. He received combined supportive therapies of PE drainage, anti-DIC agent, hemodialysis, and antimicrobials and eventually made a clinical recovery. GAS isolated from PE was found to have emm1 / speA genes, suggestive of a pathogenic strain. Clinicians should be aware of the possibility of this disease entity (pneumonia, PE, and STSS) in healthy male adults as well as children and adult women.

Intracellular Persisting Staphylococcus aureus Is the Major Pathogen in Recurrent Tonsillitis

PubMed Central

Zautner, Andreas E.; Krause, Merit; Stropahl, Gerhard; Holtfreter, Silva; Frickmann, Hagen; Maletzki, Claudia; Kreikemeyer, Bernd; Pau, Hans Wilhelm; Podbielski, Andreas

2010-01-01

Background The two major indications for tonsillectomy are recurrent tonsillitis (RT) and peritonsillar abscess (PTA). Unlike PTAs, which are primarily treated surgically, RT is often cured by tonsillectomy only after a series of failed drug therapy attempts. Although the bacteriological background of RT has been studied, the reason for the lack of success of conservative therapeutic approaches is not well understood. Methods In a prospective study, tonsil specimens from 130 RT patients and 124 PTA patients were examined for the presence of extra- and intracellular bacteria using antibiotic protection assays. Staphylococcus aureus isolates from RT patients were characterized by pulsed-field gel electrophoresis (PFGE), spa-typing and MSCRAMM-gene-PCR. Their ability for biofilm formation was tested and their cell invasiveness was confirmed by a flow cytometric invasion assay (FACS), fluorescent in situ hybridization (FISH) and immunohistochemistry. Findings S. aureus was the predominant species (57.7%) in RT patients, whereas Streptococcus pyogenes was most prevalent (20.2%) in PTA patients. Three different assays (FACS, FISH, antibiotic protection assay) showed that nearly all RT-associated S. aureus strains were located inside tonsillar cells. Correspondingly, the results of the MSCRAMM-gene-PCRs confirmed that 87% of these S. aureus isolates were invasive strains and not mere colonizers. Based upon PFGE analyses of genomic DNA and on spa-gene typing the vast majority of the S. aureus isolates belonged to different clonal lineages. Conclusions Our results demonstrate that intracellular residing S. aureus is the most common cause of RT and indicate that S. aureus uses this location to survive the effects of antibiotics and the host immune response. A German translation of the Abstract is provided as supplementary material (Abstract S1). PMID:20209109

[Incidence and distribution of Streptococcus pyogenes type M in patients treated at the Dr. Fran Mihaljević Infectious Disease Clinic in Zagreb from 1990 to 1996].

PubMed

Bejuk, Danijela; Begovac, Josip

2002-01-01

The aim of this study was to estimate the changes in the appearance and distribution of M types of Streptococcus pyogenes in different cultures from 78 patients treated during the 1990-1996 period at the Dr. Fran Mihaljević University Hospital for Infectious Diseases in Zagreb. Isolates were characterized by the T-agglutination pattern and M type and/or opacity factor type using the standards recommended by two World Health Organization Collaborating Centers for Reference and Research on streptococci from Minneapolis and Prague. In this study, 19% (15/79) of isolates were recovered from normally sterile sites, 26.6% (21/79) came from skin and 54.4% (43/79) from throat swabs. In one patient isolates from the skin and blood culture were analyzed. Of all, 92.4% (73/79) of the isolates were typed by T-agglutination pattern and 73.5% (58/79) by M protein and/or OF typing. The results of M typing showed 14 M types: M1, M3, M4, M5, M6, M11, M12, M28, M57, M58, M60, M75, M76 and M78. The most commonly isolated types were M1 and M3 (13.8%, 8/58 each), followed by M28 found in 12.1% (7/58), and M6 and M12 in 10.3% (6/58) each. These five M types accounted for 60.3% (35/58) of all isolates. Analysis to changes in the distribution of M1 and M3 types during the 1990-1991 and 1992-1993 periods revealed a significantly greater proportion of M1 and M3 isolates in the former (Fisher's two-tailed exact test, p = 0.018). A significantly greater proportion of M1 and M3 isolates was also recorded in the 1990-1991, than in 1994-1996 period. (Fisher's two-tailed exact test, P = 0.021). It was investigated whether Streptococcus pyogenes M1 and M3 types were associated with toxic and invasive infection. There were 28.2% (22/78) of patients with toxic and invasive infection: 31.9% (7/22) of them with the diagnosis of scarlet fever, whereas 68.1% (15/22) of the strains were obtained from normally sterile sites. There were 45.5% (10/22) of M1 and M3 types from patients with toxic and invasive infections. Types M6, M28 and M76 were found in an equal proportion of 9.1% (2/22), and M4, M12 and M 60 of 4.5% (1/22) each. In three strains, M type could not be identified (T8/25 SOR+, T25 SOR+ and T11 SOR+). M1 and M3 types were isolated from 10.3% (6/56) of patients with other streptococcal infections. A significantly greater proportion of M1 and M3 types was recorded in patients with toxic and invasive infections than in those with other streptococcal infections (Fisher's two-tailed exact test, p = 0.004). A multivariate logistic regression model was used to assess whether the increased proportion of streptococcal M types 1 and 3 was associated with the 1990-1991 period, or with the infection characteristics. The changes in the distribution of M types 1 and 3 were found to be significantly associated only with toxic and invasive infections (odds ratio 4.35, p = 0.025). Odds ratio suggests that patients with toxic and invasive infections had a 4.35--fold increased risk of infections caused by types M1 and M3 found in patients with other streptococcal infections. The increased proportion of M types 1 and 3 during the 1990-1991 period was more significantly associated with the characteristics of infection than with the study period.

Prevalence and molecular diversity of invasive Streptococcus dysgalactiae and Streptococcus pyogenes in a German tertiary care medical centre.

PubMed

Rößler, S; Berner, R; Jacobs, E; Toepfner, N

2018-05-03

Prevalence of invasive ß-haemolytic streptococci (BHS) at a tertiary care hospital and molecular diversity of S. pyogenes and S. dysgalactiae was studied. Between 2012 and 2016, all blood culture sets (n = 55,839), CSF (n = 8413) and soft tissue (n = 20,926) samples were analysed for BHS positivity using HYBASE software. Molecular profiles of 99 S. pyogenes and S. dysgalactiae were identified by sequencing of M protein genes (emm types) and multiplex PCR typing of 20 other virulence determinants. Streptococci contributed to 6.2% of blood, 10.7% of CSF and 14.5% of soft tissue isolates, being among the most common invasive isolates. The overall rates of invasive S. pyogenes, S. agalactiae, S. dysgalactiae and S. pneumoniae were 2.4, 4.4, 2.1, and 5.3%. Whereas S. pneumoniae was 1.5% more common in CSF samples, BHS isolates were 2-fold and 11-fold higher in bacteraemia and invasive soft tissue infections. Genetic BHS typing revealed wide molecular diversity of invasive and noninvasive group A and group G BHS, whereas one emm-type (stG62647.0) and no other virulence determinants except scpA were detected in invasive group C BHS. BHS were important invasive pathogens, outpacing S. pneumoniae in bacteraemia and invasive soft tissue infections. The incidence of S. dysgalactiae infections was comparable to that of S. pyogenes even with less diversity of molecular virulence. The results of this study emphasise the need for awareness of BHS invasiveness in humans and the need to develop BHS prevention strategies.

Global Distribution of Invasive Serotype 35D Streptococcus pneumoniae Isolates following Introduction of 13-Valent Pneumococcal Conjugate Vaccine.

PubMed

Lo, Stephanie W; Gladstone, Rebecca A; van Tonder, Andries J; Hawkins, Paulina A; Kwambana-Adams, Brenda; Cornick, Jennifer E; Madhi, Shabir A; Nzenze, Susan A; du Plessis, Mignon; Kandasamy, Rama; Carter, Philip E; Eser, Özgen Köseoglu; Ho, Pak Leung; Elmdaghri, Naima; Shakoor, Sadia; Clarke, Stuart C; Antonio, Martin; Everett, Dean B; von Gottberg, Anne; Klugman, Keith P; McGee, Lesley; Breiman, Robert F; Bentley, Stephen D

2018-07-01

A newly recognized pneumococcal serotype, 35D, which differs from the 35B polysaccharide in structure and serology by not binding to factor serum 35a, was recently reported. The genetic basis for this distinctive serology is due to the presence of an inactivating mutation in wciG , which encodes an O-acetyltransferase responsible for O-acetylation of a galactofuranose. Here, we assessed the genomic data of a worldwide pneumococcal collection to identify serotype 35D isolates and understand their geographical distribution, genetic background, and invasiveness potential. Of 21,980 pneumococcal isolates, 444 were originally typed as serotype 35B by PneumoCaT. Analysis of the wciG gene revealed 23 isolates from carriage ( n = 4) and disease ( n = 19) with partial or complete loss-of-function mutations, including mutations resulting in premature stop codons ( n = 22) and an in-frame mutation ( n = 1). These were selected for further analysis. The putative 35D isolates were geographically widespread, and 65.2% (15/23) of them was recovered after the introduction of pneumococcal conjugate vaccine 13 (PCV13). Compared with serotype 35B isolates, putative serotype 35D isolates have higher invasive disease potentials based on odds ratios (OR) (11.58; 95% confidence interval[CI], 1.42 to 94.19 versus 0.61; 95% CI, 0.40 to 0.92) and a higher prevalence of macrolide resistance mediated by mefA (26.1% versus 7.6%; P = 0.009). Using the Quellung reaction, 50% (10/20) of viable isolates were identified as serotype 35D, 25% (5/20) as serotype 35B, and 25% (5/20) as a mixture of 35B/35D. The discrepancy between phenotype and genotype requires further investigation. These findings illustrated a global distribution of an invasive serotype, 35D, among young children post-PCV13 introduction and underlined the invasive potential conferred by the loss of O-acetylation in the pneumococcal capsule. Copyright © 2018 Lo et al.

Candida species biofilm and Candida albicans ALS3 polymorphisms in clinical isolates

PubMed Central

Bruder-Nascimento, Ariane; Camargo, Carlos Henrique; Mondelli, Alessandro Lia; Sugizaki, Maria Fátima; Sadatsune, Terue; Bagagli, Eduardo

2014-01-01

Over the last decades, there have been important changes in the epidemiology of Candida infections. In recent years, Candida species have emerged as important causes of invasive infections mainly among immunocompromised patients. This study analyzed Candida spp. isolates and compared the frequency and biofilm production of different species among the different sources of isolation: blood, urine, vulvovaginal secretions and peritoneal dialysis fluid. Biofilm production was quantified in 327 Candida isolates obtained from patients attended at a Brazilian tertiary public hospital (Botucatu, Sao Paulo). C. albicans ALS3 gene polymorphism was also evaluated by determining the number of repeated motifs in the central domain. Of the 198 total biofilm-positive isolates, 72 and 126 were considered as low and high biofilm producers, respectively. Biofilm production by C. albicans was significantly lower than that by non-albicans isolates and was most frequently observed in C. tropicalis. Biofilm production was more frequent among bloodstream isolates than other clinical sources, in urine, the isolates displayed a peculiar distribution by presenting two distinct peaks, one containing biofilm-negative isolates and the other containing isolates with intense biofilm production. The numbers of tandem-repeat copies per allele were not associated with biofilm production, suggesting the evolvement of other genetic determinants. PMID:25763043

Do Native Parasitic Plants Cause More Damage to Exotic Invasive Hosts Than Native Non-Invasive Hosts? An Implication for Biocontrol

PubMed Central

Li, Junmin; Jin, Zexin; Song, Wenjing

2012-01-01

Field studies have shown that native, parasitic plants grow vigorously on invasive plants and can cause more damage to invasive plants than native plants. However, no empirical test has been conducted and the mechanism is still unknown. We conducted a completely randomized greenhouse experiment using 3 congeneric pairs of exotic, invasive and native, non-invasive herbaceous plant species to quantify the damage caused by parasitic plants to hosts and its correlation with the hosts' growth rate and resource use efficiency. The biomass of the parasitic plants on exotic, invasive hosts was significantly higher than on congeneric native, non-invasive hosts. Parasites caused more damage to exotic, invasive hosts than to congeneric, native, non-invasive hosts. The damage caused by parasites to hosts was significantly positively correlated with the biomass of parasitic plants. The damage of parasites to hosts was significantly positively correlated with the relative growth rate and the resource use efficiency of its host plants. It may be the mechanism by which parasitic plants grow more vigorously on invasive hosts and cause more damage to exotic, invasive hosts than to native, non-invasive hosts. These results suggest a potential biological control effect of native, parasitic plants on invasive species by reducing the dominance of invasive species in the invaded community. PMID:22493703

Characterization of freshly retrieved preantral follicles using a low-invasive, mechanical isolation method extended to different ruminant species.

PubMed

Langbeen, A; Jorssen, E P A; Fransen, E; Rodriguez, A P A; García, M Chong; Leroy, J L M R; Bols, P E J

2015-10-01

Due to the increased interest in preantral follicular physiology, non-invasive retrieval and morphological classification are crucial. Therefore, this study aimed: (1) to standardize a minimally invasive isolation protocol, applicable to three ruminant species; (2) to morphologically classify preantral follicles upon retrieval; and (3) to describe morphological features of freshly retrieved follicles compared with follicle characteristics using invasive methods. Bovine, caprine and ovine ovarian cortex strips were retrieved from slaughterhouse ovaries and dispersed. This suspension was filtered, centrifuged, re-suspended and transferred to a Petri dish, to which 0.025 mg/ml neutral red (NR) was added to assess the viability of the isolated follicles. Between 59 and 191 follicles per follicle class and per species were collected and classified by light microscopy, based on follicular cell morphology. Subsequently, follicle diameters were measured. The proposed isolation protocol was applicable to all three species and showed a significant, expected increase in diameter with developmental stage. With an average diameter of 37 ± 5 μm for primordial follicles, 47 ± 6.3 μm for primary follicles and 67.1 ± 13.1 μm for secondary follicles, no significant difference in diameter among the three species was observed. Bovine, caprine and ovine follicles (63, 59 and 50% respectively) were graded as viable upon retrieval. Using the same morphological characteristics as determined by invasive techniques [e.g. haematoxylin-eosin (HE) sections], cumulus cell morphology and follicle diameter could be used routinely to classify freshly retrieved follicles. Finally, we applied a mechanical, minimally invasive, follicle isolation protocol and extended it to three ruminant species, yielding viable preantral follicles without compromising further in vitro processing and allowing routine follicle characterization upon retrieval.

Putative Inv Is Essential for Basolateral Invasion of Caco-2 Cells and Acts Synergistically with OmpA To Affect In Vitro and In Vivo Virulence of Cronobacter sakazakii ATCC 29544

PubMed Central

Chandrapala, Dilini; Kim, Kyumson; Choi, Younho; Senevirathne, Amal; Kang, Dong-Hyun; Ryu, Sangryeol

2014-01-01

Cronobacter sakazakii is an opportunistic pathogen that causes neonatal meningitis and necrotizing enterocolitis. Its interaction with intestinal epithelium is important in the pathogenesis of enteric infections. In this study, we investigated the involvement of the inv gene in the virulence of C. sakazakii ATCC 29544 in vitro and in vivo. Sequence analysis of C. sakazakii ATCC 29544 inv revealed that it is different from other C. sakazakii isolates. In various cell culture models, an Δinv deletion mutant showed significantly lowered invasion efficiency, which was restored upon genetic complementation. Studying invasion potentials using tight-junction-disrupted Caco-2 cells suggested that the inv gene product mediates basolateral invasion of C. sakazakii ATCC 29544. In addition, comparison of invasion potentials of double mutant (ΔompA Δinv) and single mutants (ΔompA and Δinv) provided evidence for an additive effect of the two putative outer membrane proteins. Finally, the importance of inv and the additive effect of putative Inv and OmpA were also proven in an in vivo rat pup model. This report is the first to demonstrate two proteins working synergistically in vitro, as well as in vivo in C. sakazakii pathogenesis. PMID:24549330

Putative Inv is essential for basolateral invasion of Caco-2 cells and acts synergistically with OmpA to affect in vitro and in vivo virulence of Cronobacter sakazakii ATCC 29544.

PubMed

Chandrapala, Dilini; Kim, Kyumson; Choi, Younho; Senevirathne, Amal; Kang, Dong-Hyun; Ryu, Sangryeol; Kim, Kwang-Pyo

2014-05-01

Cronobacter sakazakii is an opportunistic pathogen that causes neonatal meningitis and necrotizing enterocolitis. Its interaction with intestinal epithelium is important in the pathogenesis of enteric infections. In this study, we investigated the involvement of the inv gene in the virulence of C. sakazakii ATCC 29544 in vitro and in vivo. Sequence analysis of C. sakazakii ATCC 29544 inv revealed that it is different from other C. sakazakii isolates. In various cell culture models, an Δinv deletion mutant showed significantly lowered invasion efficiency, which was restored upon genetic complementation. Studying invasion potentials using tight-junction-disrupted Caco-2 cells suggested that the inv gene product mediates basolateral invasion of C. sakazakii ATCC 29544. In addition, comparison of invasion potentials of double mutant (ΔompA Δinv) and single mutants (ΔompA and Δinv) provided evidence for an additive effect of the two putative outer membrane proteins. Finally, the importance of inv and the additive effect of putative Inv and OmpA were also proven in an in vivo rat pup model. This report is the first to demonstrate two proteins working synergistically in vitro, as well as in vivo in C. sakazakii pathogenesis.

Serotype distribution and antimicrobial susceptibility pattern in children≤5years with invasive pneumococcal disease in India - A systematic review.

PubMed

Singh, Jyotsana; Sundaresan, Suba; Manoharan, Anand; Shet, Anita

2017-08-16

Streptococcus pneumoniae is a leading cause of childhood diseases that result in significant morbidity and mortality in India. Commercially licensed and available pneumococcal conjugate vaccines (PCVs) include ten (PCV-10) and 13 (PCV-13) pneumococcal serotypes. Vaccines with other serotype combinations are under development. Reviewing and reporting trends and distribution of pneumococcal serotypes causing invasive pneumococcal disease in India will be useful for policy making as PCV is being introduced into India's universal immunization program. We conducted a systematic literature review of hospital based observational studies (both peer reviewed and gray literature published in English) from India available from January 1990 to December 2016. Studies that documented data on the prevalence of serotype distribution and the antimicrobial resistance pattern of S. pneumoniae in children≤5years of age were included. We screened a total number of 116 studies, of which 109 studies were excluded. Final analysis included seven studies. The most frequent pneumococcal serotypes causing invasive disease among children≤5years were 14, 1, 19F, 6B, 5, 6A, 9V and 23F. Serotype 14 and 19A were represented in most of the geographical regions studied in the reviewed articles. Currently available PCV formulations included 67.3-78.4% of all serotypes contributing to IPD among Indian children≤5years. Pneumococcal resistance to trimethoprim/sulfamethoxazole, erythromycin, penicillin, chloramphenicol, levofloxacin and cefotaxime was seen in 81%, 37%, 10%, 8%, 6% and 4% of all pneumococcal isolates respectively, while vancomycin resistance was not reported. The present review demonstrates that up to 78.4% of reported invasive pneumococcal disease in children≤5years in India are currently caused by serotypes that are included in the available licensed PCVs. However, sentinel surveillance must be continued in representative parts of the country to assess the changing trends in distribution of pneumococcal serotypes and their implication for vaccine selection and rollout in India. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison of Asymptomatic Bacteriuria Escherichia coli Isolates from Healthy Individuals versus Those from Hospital Patients Shows that Long-Term Bladder Colonization Selects for Attenuated Virulence Phenotypes

PubMed Central

Salvador, Ellaine; Wagenlehner, Florian; Köhler, Christian-Daniel; Mellmann, Alexander; Hacker, Jörg; Svanborg, Catharina

2012-01-01

Asymptomatic bacteriuria (ABU) is a condition where bacteria stably colonize the urinary tract, in a manner closely resembling commensalism at other mucosal sites. The patients carry >105 CFU/ml for extended periods of time and rarely develop symptoms. Contrasting the properties of ABU strains to those of uropathogenic isolates causing symptomatic infection is therefore highly relevant to understand mechanisms of bacterial adaptation. The prototype ABU strain Escherichia coli 83972 has a smaller genome than uropathogenic E. coli (UPEC) strains with deletions or point mutations in several virulence genes, suggesting that ABU strains undergo a programmed reductive evolution within human hosts. This study addressed if these observations can be generalized. Strains causing ABU in outpatients or hospitalized patients after catheterization or other invasive procedures were compared to commensal E. coli isolates from the intestinal flora of healthy individuals. Notably, clonal complex 73 (CC73) was a prominent phylogenetic lineage dominated by ABU isolates. ABU isolates from outpatients and hospitalized patients had a similar overall virulence gene repertoire, which distinguished them from many commensals, but typical UPEC virulence genes were less frequently attenuated in hospital strains than in outpatient strains or commensals. The decreased virulence potential of outpatient ABU isolates relative to that of ABU strains from hospitalized patients supports the hypothesis that loss of expression or decay of virulence genes facilitates long-term carriage and adaptation to host environments. PMID:22104113

Molecular Epidemiology of Invasive Listeriosis due to Listeria monocytogenes in a Spanish Hospital over a Nine-Year Study Period, 2006-2014.

PubMed

Ariza-Miguel, Jaime; Fernández-Natal, María Isabel; Soriano, Francisco; Hernández, Marta; Stessl, Beatrix; Rodríguez-Lázaro, David

2015-01-01

We investigated the pathogenicity, invasiveness, and genetic relatedness of 17 clinical Listeria monocytogenes stains isolated over a period of nine years (2006-2014). All isolates were phenotypically characterised and growth patterns were determined. The antimicrobial susceptibility of L. monocytogenes isolates was determined in E-tests. Invasion assays were performed with epithelial HeLa cells. Finally, L. monocytogenes isolates were subtyped by PFGE and MLST. All isolates had similar phenotypic characteristics (β-haemolysis and lecithinase activity), and three types of growth curve were observed. Bacterial recovery rates after invasion assays ranged from 0.09% to 7.26% (1.62 ± 0.46). MLST identified 11 sequence types (STs), and 14 PFGE profiles were obtained, indicating a high degree of genetic diversity. Genetic studies unequivocally revealed the occurrence of one outbreak of listeriosis in humans that had not previously been reported. This outbreak occurred in October 2009 and affected three patients from neighbouring towns. In conclusion, the molecular epidemiological analysis clearly revealed a cluster (three human cases, all ST1) of not previously reported listeriosis cases in northwestern Spain. Our findings indicate that molecular subtyping, in combination with epidemiological case analysis, is essential and should be implemented in routine diagnosis, to improve the tracing of the sources of outbreaks.

Analysis of trade-offs between threats of invasion by nonnative brook trout (Salvelinus fontinalis) and intentional isolation for native westslope cutthroat trout (Oncorhynchus clarkii lewisi)

USGS Publications Warehouse

Peterson, D.P.; Rieman, B.E.; Dunham, J.B.; Fausch, K.D.; Young, M.K.

2008-01-01

Native salmonid fishes often face simultaneous threats from habitat fragmentation and invasion by nonnative trout species. Unfortunately, management actions to address one may create or exacerbate the other. A consistent decision process would include a systematic analysis of when and where intentional use or removal of barriers is the most appropriate action. We developed a Bayesian belief network as a tool for such analyses. We focused on native westslope cutthroat trout (Oncorhynchus clarkii lewisi) and nonnative brook trout (Salvelinus fontinalis) and considered the environmental factors influencing both species, their potential interactions, and the effects of isolation on the persistence of local cutthroat trout populations. The trade-offs between isolation and invasion were strongly influenced by size and habitat quality of the stream network to be isolated and existing demographic linkages within and among populations. An application of the model in several sites in western Montana (USA) showed the process could help clarify management objectives and options and prioritize conservation actions among streams. The approach can also facilitate communication among parties concerned with native salmonids, nonnative fish invasions, barriers and intentional isolation, and management of the associated habitats and populations. ?? 2008 NRC.

Adhesive and invasive capacities of Edwardsiella tarda isolated from South American sea lion.

PubMed

Fernández, Araceli; Villanueva, María Paz; González, Mario; Fernández, Fabiola; Latif, Fadua; Flores, Sandra Nonier; Fernández, Heriberto

2014-01-01

Edwarsiella tarda is a zoonotic bacterium that can be isolated from humans, animals and the environment. Although E. tarda is primarily considered a fish pathogen, it is the only species of its genus considered to be pathogenic for humans as well. A survey of zoonotic intestinal bacteria in fresh feces from South American sea lions (SASL) Otaria flavescens, reported E. tarda as the most frequently isolated species. In this study, we used HEp-2 cells to establish in vitro the adherence and invasive ability of 17 E. tarda strains isolated from SASL fecal material. All the strains were able to adhere and invade HEp-2 cells with adhesion and invasion percentages ranging from 56 to 100% and 21 to 74%, respectively. Despite the expression of these pathogenic factors, further investigation is needed to determine whether this bacterium could play a role as primary pathogen for this and other species of pinnipeds.

Adhesive and invasive capacities of Edwarsiella tarda isolated from South American sea lion

PubMed Central

Fernández, Araceli; Villanueva, María Paz; González, Mario; Fernández, Fabiola; Latif, Fadua; Flores, Sandra Nonier; Fernández, Heriberto

2014-01-01

Edwarsiella tarda is a zoonotic bacterium that can be isolated from humans, animals and the environment. Although E. tarda is primarily considered a fish pathogen, it is the only species of its genus considered to be pathogenic for humans as well. A survey of zoonotic intestinal bacteria in fresh feces from South American sea lions (SASL) Otaria flavescens, reported E. tarda as the most frequently isolated species. In this study, we used HEp-2 cells to establish in vitro the adherence and invasive ability of 17 E. tarda strains isolated from SASL fecal material. All the strains were able to adhere and invade HEp-2 cells with adhesion and invasion percentages ranging from 56 to 100% and 21 to 74%, respectively. Despite the expression of these pathogenic factors, further investigation is needed to determine whether this bacterium could play a role as primary pathogen for this and other species of pinnipeds. PMID:25477948

Whole-Genome Sequences of Nonencapsulated Haemophilus influenzae Strains Isolated in Italy

PubMed Central

Giufrè, Maria; De Chiara, Matteo; Censini, Stefano; Guidotti, Silvia; Torricelli, Giulia; De Angelis, Gabriella; Cardines, Rita; Pizza, Mariagrazia; Muzzi, Alessandro; Soriani, Marco

2015-01-01

Haemophilus influenzae is an important human pathogen involved in invasive disease. Here, we report the whole-genome sequences of 11 nonencapsulated H. influenzae (ncHi) strains isolated from both invasive disease and healthy carriers in Italy. This genomic information will enrich our understanding of the molecular basis of ncHi pathogenesis. PMID:25814593

Molecular Tracing to Find Source of Protracted Invasive Listeriosis Outbreak, Southern Germany, 2012-2016.

PubMed

Kleta, Sylvia; Hammerl, Jens Andre; Dieckmann, Ralf; Malorny, Burkhard; Borowiak, Maria; Halbedel, Sven; Prager, Rita; Trost, Eva; Flieger, Antje; Wilking, Hendrik; Vygen-Bonnet, Sabine; Busch, Ulrich; Messelhäußer, Ute; Horlacher, Sabine; Schönberger, Katharina; Lohr, Dorothee; Aichinger, Elisabeth; Luber, Petra; Hensel, Andreas; Al Dahouk, Sascha

2017-10-01

We investigated 543 Listeria monocytogenes isolates from food having a temporal and spatial distribution compatible with that of the invasive listeriosis outbreak occurring 2012-2016 in southern Germany. Using forensic microbiology, we identified several products from 1 manufacturer contaminated with the outbreak genotype. Continuous molecular surveillance of food isolates could prevent such outbreaks.

Hypervirulent emm59 Clone in Invasive Group A Streptococcus Outbreak, Southwestern United States.

PubMed

Engelthaler, David M; Valentine, Michael; Bowers, Jolene; Pistole, Jennifer; Driebe, Elizabeth M; Terriquez, Joel; Nienstadt, Linus; Carroll, Mark; Schumacher, Mare; Ormsby, Mary Ellen; Brady, Shane; Livar, Eugene; Yazzie, Del; Waddell, Victor; Peoples, Marie; Komatsu, Kenneth; Keim, Paul

2016-04-01

The hyper-virulent emm59 genotype of invasive group A Streptococcus was identified in northern Arizona in 2015. Eighteen isolates belonging to a genomic cluster grouped most closely with recently identified isolates in New Mexico. The continued transmission of emm59 in the southwestern United States poses a public health concern.

Oral Candida albicans isolates from HIV-positive individuals have similar in vitro biofilm-forming ability and pathogenicity as invasive Candida isolates

PubMed Central

2011-01-01

Background Candida can cause mucocutaneous and/or systemic infections in hospitalized and immunosuppressed patients. Most individuals are colonized by Candida spp. as part of the oral flora and the intestinal tract. We compared oral and systemic isolates for the capacity to form biofilm in an in vitro biofilm model and pathogenicity in the Galleria mellonella infection model. The oral Candida strains were isolated from the HIV patients and included species of C. albicans, C. glabrata, C. tropicalis, C. parapsilosis, C. krusei, C. norvegensis, and C. dubliniensis. The systemic strains were isolated from patients with invasive candidiasis and included species of C. albicans, C. glabrata, C. tropicalis, C. parapsilosis, C. lusitaniae, and C. kefyr. For each of the acquired strains, biofilm formation was evaluated on standardized samples of silicone pads and acrylic resin. We assessed the pathogenicity of the strains by infecting G. mellonella animals with Candida strains and observing survival. Results The biofilm formation and pathogenicity in Galleria was similar between oral and systemic isolates. The quantity of biofilm formed and the virulence in G. mellonella were different for each of the species studied. On silicone pads, C. albicans and C. dubliniensis produced more biofilm (1.12 to 6.61 mg) than the other species (0.25 to 3.66 mg). However, all Candida species produced a similar biofilm on acrylic resin, material used in dental prostheses. C. albicans, C. dubliniensis, C. tropicalis, and C. parapsilosis were the most virulent species in G. mellonella with 100% of mortality, followed by C. lusitaniae (87%), C. novergensis (37%), C. krusei (25%), C. glabrata (20%), and C. kefyr (12%). Conclusions We found that on silicone pads as well as in the Galleria model, biofilm formation and virulence depends on the Candida species. Importantly, for C. albicans the pathogenicity of oral Candida isolates was similar to systemic Candida isolates, suggesting that Candida isolates have similar biofilm-forming ability and virulence regardless of the infection site from which it was isolated. PMID:22053894

The post-vaccine microevolution of invasive Streptococcus pneumoniae

PubMed Central

Cremers, Amelieke J. H.; Mobegi, Fredrick M.; de Jonge, Marien I.; van Hijum, Sacha A. F. T.; Meis, Jacques F.; Hermans, Peter W. M.; Ferwerda, Gerben; Bentley, Stephen D.; Zomer, Aldert L.

2015-01-01

The 7-valent pneumococcal conjugated vaccine (PCV7) has affected the genetic population of Streptococcus pneumoniae in pediatric carriage. Little is known however about pneumococcal population genomics in adult invasive pneumococcal disease (IPD) under vaccine pressure. We sequenced and serotyped 349 strains of S. pneumoniae isolated from IPD patients in Nijmegen between 2001 and 2011. Introduction of PCV7 in the Dutch National Immunization Program in 2006 preluded substantial alterations in the IPD population structure caused by serotype replacement. No evidence could be found for vaccine induced capsular switches. We observed that after a temporary bottleneck in gene diversity after the introduction of PCV7, the accessory gene pool re-expanded mainly by genes already circulating pre-PCV7. In the post-vaccine genomic population a number of genes changed frequency, certain genes became overrepresented in vaccine serotypes, while others shifted towards non-vaccine serotypes. Whether these dynamics in the invasive pneumococcal population have truly contributed to invasiveness and manifestations of disease remains to be further elucidated. We suggest the use of whole genome sequencing for surveillance of pneumococcal population dynamics that could give a prospect on the course of disease, facilitating effective prevention and management of IPD. PMID:26492862

British Society for Medical Mycology best practice recommendations for the diagnosis of serious fungal diseases.

PubMed

Schelenz, Silke; Barnes, Rosemary A; Barton, Richard C; Cleverley, Joanne R; Lucas, Sebastian B; Kibbler, Christopher C; Denning, David W

2015-04-01

Invasive fungal diseases are an important cause of morbidity and mortality in a wide range of patients, and early diagnosis and management are a challenge. We therefore did a review of the scientific literature to generate a series of key recommendations for the appropriate use of microbiological, histological, and radiological diagnostic methods for diagnosis of invasive fungal diseases. The recommendations emphasise the role of microscopy in rapid diagnosis and identification of clinically significant isolates to species level, and the need for susceptibility testing of all Aspergillus spp, if treatment is to be given. In this Review, we provide information to improve understanding of the importance of antigen detection for cryptococcal disease and invasive aspergillosis, the use of molecular (PCR) diagnostics for aspergillosis, and the crucial role of antibody detection for chronic and allergic aspergillosis. Furthermore, we consider the importance of histopathology reporting with a panel of special stains, and emphasise the need for urgent (<48 hours) and optimised imaging for patients with suspected invasive fungal infection. All 43 recommendations are auditable and should be used to ensure best diagnostic practice and improved outcomes for patients. Copyright © 2015 Elsevier Ltd. All rights reserved.

Progressive Increase in Antimicrobial Resistance among Invasive Isolates of Haemophilus influenzae Obtained from Children Admitted to a Hospital in Kilifi, Kenya, from 1994 to 2002

PubMed Central

Scott, J. Anthony G.; Mwarumba, Salim; Ngetsa, Caroline; Njenga, Salome; Lowe, Brett S.; Slack, Mary P. E.; Berkley, James A.; Mwangi, Isaiah; Maitland, Kathryn; English, Mike; Marsh, Kevin

2005-01-01

Etest susceptibilities to amoxicillin, chloramphenicol, and trimethoprim-sulfamethoxazole of 240 invasive isolates of Haemophilus influenzae cultured from children in rural Kenya were 66%, 66%, and 38%, respectively. Resistance increased markedly over 9 years and was concentrated among serotype b isolates. In Africa, the increasing cost of treating resistant infections supports economic arguments for prevention through conjugate H. influenzae type b immunization. PMID:15980390

Cellular injuries of spray-dried Lactobacillus spp. isolated from kefir and their impact on probiotic properties.

PubMed

Golowczyc, Marina A; Silva, Joana; Teixeira, Paula; De Antoni, Graciela L; Abraham, Analía G

2011-01-05

The injuries caused by spray drying (SD) of three potential probiotic lactobacilli isolated from kefir grains and the impact on some probiotic properties, were evaluated. Results demonstrated that Lactobacillus plantarum 83114 and L. kefir 8321 showed a slight reduction of viability (0.11 and 0.29 log CFU/ml respectively) after SD process, and L. kefir 8348 was found to be more sensitive to the process with a reduction in viability of 0.70 log CFU/ml. Neither membrane damage, evaluated by increased sensitivity to NaCl, lysozyme, bile salt and penicillin G, nor changes in acidifying activity in MRS and milk by lactobacilli were detected after SD. L. plantarum 83114 and L. kefir 8321 after SD did not lose their capacity to adhere to intestinal cells. Nevertheless, L. kefir 8348 showed a significant loss of adhesion capacity after SD. In addition, rehydrated spray-dried L. kefir 8321 retained the ability to protect against Salmonella invasion of intestinal cells. This effect was observed when L. kefir is co-incubated with Salmonella before invasion assay. This work shows that the membrane integrity evaluated by indirect methods and some probiotic properties of lactobacilli isolated from kefir did not change significantly after SD, and these powders could be used in functional foods applications. Copyright © 2010 Elsevier B.V. All rights reserved.

Genetic and Phenotypic Characterization of a Salmonella enterica serovar Enteritidis Emerging Strain with Superior Intra-macrophage Replication Phenotype

PubMed Central

Shomer, Inna; Avisar, Alon; Desai, Prerak; Azriel, Shalhevet; Smollan, Gill; Belausov, Natasha; Keller, Nathan; Glikman, Daniel; Maor, Yasmin; Peretz, Avi; McClelland, Michael; Rahav, Galia; Gal-Mor, Ohad

2016-01-01

Salmonella enterica serovar Enteritidis (S. Enteritidis) is one of the ubiquitous Salmonella serovars worldwide and a major cause of food-born outbreaks, which are often associated with poultry and poultry derivatives. Here we report a nation-wide S. Enteritidis clonal outbreak that occurred in Israel during the last third of 2015. Pulsed field gel electrophoresis and whole genome sequencing identified genetically related strains that were circulating in Israel as early as 2008. Global comparison linked this outbreak strain to several clinical and marine environmental isolates that were previously isolated in California and Canada, indicating that similar strains are prevalent outside of Israel. Phenotypic comparison between the 2015 outbreak strain and other clinical and reference S. Enteritidis strains showed only limited intra-serovar phenotypic variation in growth in rich medium, invasion into Caco-2 cells, uptake by J774.1A macrophages, and host cell cytotoxicity. In contrast, significant phenotypic variation was shown among different S. Enteritidis isolates when biofilm-formation, motility, invasion into HeLa cells and uptake by THP-1 human macrophages were studied. Interestingly, the 2015 outbreak clone was found to possess superior intra-macrophage replication ability within both murine and human macrophages in comparison to the other S. Enteritidis strains studied. This phenotype is likely to play a role in the virulence and host-pathogen interactions of this emerging clone. PMID:27695450

Invasive bacterial disease trends and characterization of group B streptococcal isolates among young infants in southern Mozambique, 2001-2015.

PubMed

Sigaúque, Betuel; Kobayashi, Miwako; Vubil, Delfino; Nhacolo, Ariel; Chaúque, Alberto; Moaine, Benild; Massora, Sérgio; Mandomando, Inácio; Nhampossa, Tacilta; Bassat, Quique; Pimenta, Fabiana; Menéndez, Clara; Carvalho, Maria da Gloria; Macete, Eusebio; Schrag, Stephanie J

2018-01-01

Maternal group B streptococcal (GBS) vaccines under development hold promise to prevent GBS disease in young infants. Sub-Saharan Africa has the highest estimated disease burden, although data on incidence and circulating strains are limited. We described invasive bacterial disease (IBD) trends among infants <90 days in rural Mozambique during 2001-2015, with a focus on GBS epidemiology and strain characteristics. Community-level birth and mortality data were obtained from Manhiça's demographic surveillance system. IBD cases were captured through ongoing surveillance at Manhiça district hospital. Stored GBS isolates from cases underwent serotyping by multiplex PCR, antimicrobial susceptibility testing, and whole genome sequencing. There were 437 IBD cases, including 57 GBS cases. Significant declines in overall IBD, neonatal mortality, and stillbirth rates were observed (P<0.0001), but not for GBS (P = 0.17). In 2015, GBS was the leading cause of young infant IBD (2.7 per 1,000 live births). Among 35 GBS isolates available for testing, 31 (88.6%) were highly related serotype III isolates within multilocus sequence types (STs) 17 (68.6%) or 109 (20.0%). All seven ST109 isolates (21.9%) had elevated minimum inhibitory concentration (MIC) to penicillin (≥0.12 μg/mL) associated with penicillin-binding protein (PBP) 2x substitution G398A. Epidemiologic and molecular data suggest this is a well-established clone. A notable young infant GBS disease burden persisted despite improvements in overall maternal and neonatal health. We report an established strain with pbp2x point mutation, a first-step mutation associated with reduced penicillin susceptibility within a well-known virulent lineage in rural Mozambique. Our findings further underscores the need for non-antibiotic GBS prevention strategies.

Streptococcus dysgalactiae subsp. dysgalactiae isolated from milk of the bovine udder as emerging pathogens: In vitro and in vivo infection of human cells and zebrafish as biological models.

PubMed

Alves-Barroco, Cinthia; Roma-Rodrigues, Catarina; Raposo, Luís R; Brás, Catarina; Diniz, Mário; Caço, João; Costa, Pedro M; Santos-Sanches, Ilda; Fernandes, Alexandra R

2018-03-25

Streptococcus dysgalactiae subsp. dysgalactiae (SDSD) is a major cause of bovine mastitis and has been regarded as an animal-restricted pathogen, although rare infections have been described in humans. Previous studies revealed the presence of virulence genes encoded by phages of the human pathogen Group A Streptococcus pyogenes (GAS) in SDSD isolated from the milk of bovine udder with mastitis. The isolates SDSD VSD5 and VSD13 could adhere and internalize human primary keratinocyte cells, suggesting a possible human infection potential of bovine isolates. In this work, the in vitro and in vivo potential of SDSD to internalize/adhere human cells of the respiratory track and zebrafish as biological models was evaluated. Our results showed that, in vitro, bovine SDSD strains could interact and internalize human respiratory cell lines and that this internalization was dependent on an active transport mechanism and that, in vivo, SDSD are able to cause invasive infections producing zebrafish morbidity and mortality. The infectious potential of these isolates showed to be isolate-specific and appeared to be independent of the presence or absence of GAS phage-encoded virulence genes. Although the infection ability of the bovine SDSD strains was not as strong as the human pathogenic S. pyogenes in the zebrafish model, results suggested that these SDSD isolates are able to interact with human cells and infect zebrafish, a vertebrate infectious model, emerging as pathogens with zoonotic capability. © 2018 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Serotypes, surface proteins, and clinical syndromes of invasive Group B streptococcal infections in northern Taiwan, 1998-2009.

PubMed

Wong, Swee Siang; Tsui, Kochung; Liu, Qin-Dong; Lin, Li-Chen; Tsai, Chim Ren; Chen, Li-Chun; Huang, Cheng Hua

2011-02-01

The incidence of invasive Group B streptococcal (GBS) infections is increasing in the elderly and immunocompromised adults in many countries worldwide. There are, however, few reports regarding the current status of the infection in northern Taiwan. This study investigated retrospectively the molecular epidemiology and clinical syndromes of the invasive GBS diseases in a tertiary care hospital in northern Taiwan over the past decade. One hundred twenty episodes of invasive GBS disease were recorded at Cathay General Hospital, a tertiary care, teaching hospital in northern Taiwan, from January 1998 to June 2009. Clinical information was acquired from medical records. Capsular serotypes and alpha family of surface proteins were genotyped with multiplex and specific polymerase chain reaction. Of all episodes, 58.3% was found in the elderly (age ≥ 65), 36.1% in nonpregnant women and young adults (age 18-64), and 5.9% in the neonates (0-90 days). Case-fatality rate was 6.7%. Eighty-three (69%) of the invasive isolates were available for genotyping. In sharp contrast to the studies in southern Taiwan (1991-2004), Type Ib (26.5%) was the most frequent invasive isolate, followed by V (22.9%), III (18.1%), VI (12%), Ia (10.8%), II (6%), VIII (2.4%), and nontypable strain (1.2%). In particular, Serotype VI, which had been rarely implicated in invasive infection, emerged as a significant pathogen. A significant trend of increase in incidence was observed for the infection (p<0.0001), with concurrent increase of cases in the elderly and of Serotype Ib and VI. There was significant association with young adults of Type II and III and chronic skin conditions and older adults with Type Ia and V and chronic cardiovascular diseases. Type V was closely associated with skin and soft tissue infection. Recurrent episodes (10%) occurred most often in patients with concomitant malignancy, with an average of 314 days for recurrence. The incidence of GBS invasive infection among nonpregnant women and adults is rising in northern Taiwan, particularly in the elderly caused by Serotype Ib and VI. Population-based surveillance program should be implanted for assessment of the disease burden to the susceptible adult population. Copyright © 2011. Published by Elsevier B.V.

Kingella kingae expresses four structurally distinct polysaccharide capsules that differ in their correlation with invasive disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Starr, Kimberly F.; Porsch, Eric A.; Seed, Patrick C.

Kingella kingae is an encapsulated gram-negative organism that is a common cause of osteoarticular infections in young children. In earlier work, we identified a glycosyltransferase gene called csaA that is necessary for synthesis of the [3)-β-GalpNAc-(1→5)-β-Kdop-(2→] polysaccharide capsule (type a) in K. kingae strain 269–492. In the current study, we analyzed a large collection of invasive and carrier isolates from Israel and found that csaA was present in only 47% of the isolates. Further examination of this collection using primers based on the sequence that flanks csaA revealed three additional gene clusters (designated the csb, csc, and csd loci), allmore » encoding predicted glycosyltransferases. The csb locus contains the csbA, csbB, and csbC genes and is associated with a capsule that is a polymer of [6)-α-GlcpNAc-(1→5)-β-(8-OAc)Kdop-(2→] (type b). The csc locus contains the cscA, cscB, and cscC genes and is associated with a capsule that is a polymer of [3)-β-Ribf-(1→2)-β-Ribf-(1→2)-β-Ribf-(1→4)-β-Kdop-(2→] (type c). The csd locus contains the csdA, csdB, and csdC genes and is associated with a capsule that is a polymer of [P-(O→3)[β-Galp-(1→4)]-β-GlcpNAc-(1→3)-α-GlcpNAc-1-] (type d). Introduction of the csa, csb, csc, and csd loci into strain KK01Δcsa, a strain 269–492 derivative that lacks the native csaA gene, was sufficient to produce the type a capsule, type b capsule, type c capsule, and type d capsule, respectively, indicating that these loci are solely responsible for determining capsule type in K. kingae. Further analysis demonstrated that 96% of the invasive isolates express either the type a or type b capsule and that a disproportionate percentage of carrier isolates express the type c or type d capsule. Lastly, these results establish that there are at least four structurally distinct K. kingae capsule types and suggest that capsule type plays an important role in promoting K. kingae invasive disease« less

Kingella kingae expresses four structurally distinct polysaccharide capsules that differ in their correlation with invasive disease

DOE PAGES

Starr, Kimberly F.; Porsch, Eric A.; Seed, Patrick C.; ...

2016-10-19

Kingella kingae is an encapsulated gram-negative organism that is a common cause of osteoarticular infections in young children. In earlier work, we identified a glycosyltransferase gene called csaA that is necessary for synthesis of the [3)-β-GalpNAc-(1→5)-β-Kdop-(2→] polysaccharide capsule (type a) in K. kingae strain 269–492. In the current study, we analyzed a large collection of invasive and carrier isolates from Israel and found that csaA was present in only 47% of the isolates. Further examination of this collection using primers based on the sequence that flanks csaA revealed three additional gene clusters (designated the csb, csc, and csd loci), allmore » encoding predicted glycosyltransferases. The csb locus contains the csbA, csbB, and csbC genes and is associated with a capsule that is a polymer of [6)-α-GlcpNAc-(1→5)-β-(8-OAc)Kdop-(2→] (type b). The csc locus contains the cscA, cscB, and cscC genes and is associated with a capsule that is a polymer of [3)-β-Ribf-(1→2)-β-Ribf-(1→2)-β-Ribf-(1→4)-β-Kdop-(2→] (type c). The csd locus contains the csdA, csdB, and csdC genes and is associated with a capsule that is a polymer of [P-(O→3)[β-Galp-(1→4)]-β-GlcpNAc-(1→3)-α-GlcpNAc-1-] (type d). Introduction of the csa, csb, csc, and csd loci into strain KK01Δcsa, a strain 269–492 derivative that lacks the native csaA gene, was sufficient to produce the type a capsule, type b capsule, type c capsule, and type d capsule, respectively, indicating that these loci are solely responsible for determining capsule type in K. kingae. Further analysis demonstrated that 96% of the invasive isolates express either the type a or type b capsule and that a disproportionate percentage of carrier isolates express the type c or type d capsule. Lastly, these results establish that there are at least four structurally distinct K. kingae capsule types and suggest that capsule type plays an important role in promoting K. kingae invasive disease« less

Antifungal resistance: current trends and future strategies to combat

PubMed Central

Wiederhold, Nathan P

2017-01-01

Antifungal resistance represents a major clinical challenge to clinicians responsible for treating invasive fungal infections due to the limited arsenal of systemically available antifungal agents. In addition current drugs may be limited by drug–drug interactions and serious adverse effects/toxicities that prevent their prolonged use or dosage escalation. Fluconazole resistance is of particular concern in non-Candida albicans species due to the increased incidence of infections caused by these species in different geographic locations worldwide and the elevated prevalence of resistance to this commonly used azole in many institutions. C. glabrata resistance to the echinocandins has also been documented to be rising in several US institutions, and a higher percentage of these isolates may also be azole resistant. Azole resistance in Aspergillus fumigatus due to clinical and environmental exposure to this class of agents has also been found worldwide, and these isolates can cause invasive infections with high mortality rates. In addition, several species of Aspergillus, and other molds, including Scedosporium and Fusarium species, have reduced susceptibility or pan-resistance to clinically available antifungals. Various investigational antifungals are currently in preclinical or clinical development, including several of them that have the potential to overcome resistance observed against the azoles and the echinocandins. These include agents that also target ergosterol and b-glucan biosynthesis, as well as compounds with novel mechanisms of action that may also overcome the limitations of currently available antifungal classes, including both resistance and adverse effects/toxicity. PMID:28919789

Burden of group A streptococcal meningitis in Salvador, Brazil: report of 11 years of population-based surveillance

PubMed Central

Santos, Milena Soares; de Sousa Ribeiro, Guilherme; Oliveira, Tainara Queiroz; Santos, Renan Cardoso Nery; Gouveia, Edilane; Salgado, Kátia; Takahashi, Daniele; Fontes, Cleuber; Campos, Leila Carvalho; Reis, Mitermayer Galvão; Ko, Albert Icksang; Reis, Joice Neves

2009-01-01

1.2 Summary Background Over recent decades, a resurgence of invasive group A streptococcal (GAS) infections has been observed; GAS remains a rare cause of pyogenic meningitis. We report herein population-based findings of long-term surveillance for GAS meningitis in Salvador, Brazil, and estimate the overall burden of invasive GAS infections. Methods From February 1996 to January 2006 we conducted active surveillance for GAS meningitis in the state reference hospital for infectious diseases in Salvador, Brazil. Data on clinical presentation, laboratory records, and outcome were collected through interviews and chart review. GAS isolates were evaluated for antimicrobial susceptibility and emm type. Results We identified 20 cases of GAS meningitis, which accounted for 0.9% of all culture-proven bacterial meningitis in the study period. The mean annual incidence of GAS meningitis was 0.03 cases per 100 000 population in metropolitan Salvador and peaked in children <1 year of age (0.67 cases per 100 000 population). Among 17 cases with clinical information available, 41% required intensive care unit support and 25% died. Tested isolates were susceptible to penicillin and exhibited large emm type diversity. Based on the incidence of GAS meningitis, we estimate that the annual incidence of GAS infection is 3 cases per 100 000 population in metropolitan Salvador. Conclusions Although rare, GAS is a life-threatening cause of bacterial meningitis. Knowledge of the incidence and emm type variability of the disease is necessary for planning immunization strategies. PMID:19019714

Evaluation of streptococcal toxic shock-like syndrome caused by group B streptococcus in adults in Japan between 2009 and 2013.

PubMed

Ikebe, Tadayoshi; Chiba, Kazuki; Shima, Tomoko; Masuda, Chieko; Okuno, Rumi; Ohya, Hitomi; Ogata, Kikuyo; Katsukawa, Chihiro; Kawahara, Ryuji; Tominaga, Kiyoshi; Yabata, Junko; Tada, Yuki; Okabe, Nobuhiko; Watanabe, Haruo; Chang, Bin; Ogawa, Michinaga; Ohnishi, Makoto

2015-03-01

Infection with Streptococcus agalactiae has long been recognized in infants. In recent years, S. agalactiae is an important cause of morbidity and mortality among adults and among those with underlying medical condition. Several cases of GBS infection and more fulminant disease similar to streptococcal toxic shock syndrome have recently been reported. We report here that 19 S. agalactiae strains were isolated from streptococcal toxic shock-like syndrome cases involving adult patients in Japan between 2009 and 2013. The average age of the patients was 66.3 years. At least one underlying disease was present in 47.4% (9/19) of the patients. The most prevalent serotype among these strains was Ib. All serotype Ib strains belonged to clonal complex 10 and were ciprofloxacin resistant. In contrast, all strains were susceptible to penicillin G, ampicillin, cefazolin, cefotaxime, imipenem, panipenem, and linezolid. The characteristic type distributions of streptococcal toxic shock-like syndrome isolates differed between isolates obtained from vaginal swabs of women and infants with invasive infections. Copyright © 2014 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Increase in Genetic Diversity of Haemophilus influenzae Serotype b (Hib) Strains after Introduction of Hib Vaccination in The Netherlands

PubMed Central

Schouls, Leo M.; van der Ende, Arie; van de Pol, Ingrid; Schot, Corrie; Spanjaard, Lodewijk; Vauterin, Paul; Wilderbeek, Dorus; Witteveen, Sandra

2005-01-01

Recently, there has been an increase in The Netherlands in the number of cases of invasive disease caused by Haemophilus influenzae serotype b (Hib). To study a possible change in the Hib population that could explain the rise in incidence, a multiple-locus variable number tandem repeats analysis (MLVA) was developed to genotype H. influenzae isolates. The MLVA enabled the differentiation of H. influenzae serotype b strains with higher discriminatory power than multilocus sequence typing (MLST). MLVA profiles of noncapsulated H. influenzae and H. influenzae serotype f strains were more heterogeneous than serotype b strains and were distinct from Hib, although some overlap occurred. The MLVA was used to genotype a collection of 520 H. influenzae serotype b strains isolated from patients in The Netherlands with invasive disease. The strains were collected from 1983 from 2002, covering a time period of 10 years before and 9 years after the introduction of the Hib vaccine in the Dutch national vaccination program. MLVA revealed a sharp increase in genetic diversity of Hib strains isolated from neonates to 4-year-old patients after 1993, when the Hib vaccine was introduced. Hib strains isolated from patients older than 4 years in age were genetically diverse, and no significant change in diversity was seen after the introduction of the vaccine. These observations suggest that after the introduction of the Hib vaccine young children no longer constitute the reservoir for Hib and that they are infected by adults carrying genetically diverse Hib strains. PMID:15956392

Shielding of a lipooligosaccharide IgM epitope allows evasion of neutrophil-mediated killing of an invasive strain of nontypeable Haemophilus influenzae.

PubMed

Langereis, Jeroen D; Weiser, Jeffrey N

2014-07-22

Nontypeable Haemophilus influenzae is a frequent cause of noninvasive mucosal inflammatory diseases but may also cause invasive diseases, such as sepsis and meningitis, especially in children and the elderly. Infection by nontypeable Haemophilus influenzae is characterized by recruitment of neutrophilic granulocytes. Despite the presence of a large number of neutrophils, infections with nontypeable Haemophilus influenzae are often not cleared effectively by the antimicrobial activity of these immune cells. Herein, we examined how nontypeable Haemophilus influenzae evades neutrophil-mediated killing. Transposon sequencing (Tn-seq) was used on an isolate resistant to neutrophil-mediated killing to identify genes required for its survival in the presence of human neutrophils and serum, which provided a source of complement and antibodies. Results show that nontypeable Haemophilus influenzae prevents complement-dependent neutrophil-mediated killing by expression of surface galactose-containing oligosaccharide structures. These outer-core structures block recognition of an inner-core lipooligosaccharide epitope containing glucose attached to heptose HepIII-β1,2-Glc by replacement with galactose attached to HepIII or through shielding HepIII-β1,2-Glc by phase-variable attachment of oligosaccharide chain extensions. When the HepIII-β1,2-Glc-containing epitope is expressed and exposed, nontypeable Haemophilus influenzae is opsonized by naturally acquired IgM generally present in human serum and subsequently phagocytosed and killed by human neutrophils. Clinical nontypeable Haemophilus influenzae isolates containing galactose attached to HepIII that are not recognized by this IgM are more often found to cause invasive infections. Importance: Neutrophils are white blood cells that specialize in killing pathogens and are recruited to sites of inflammation. However, despite the presence of large numbers of neutrophils in the middle ear cavity and lungs of patients with otitis media or chronic obstructive pulmonary disease, respectively, the bacterium nontypeable Haemophilus influenzae is often not effectively cleared from these locations by these immune cells. In order to understand how nontypeable Haemophilus influenzae is able to cause inflammatory diseases in the presence of neutrophils, we determined the mechanism that underlies resistance to neutrophil-mediated killing. We have shown that nontypeable Haemophilus influenzae prevents binding of antibodies of the IgM subtype through changes in their surface lipooligosaccharide structure, thereby preventing complement activation and clearance by human neutrophils. Copyright © 2014 Langereis and Weiser.

Spontaneous mutations in Streptococcus pyogenes isolates from streptococcal toxic shock syndrome patients play roles in virulence

PubMed Central

Ikebe, Tadayoshi; Matsumura, Takayuki; Nihonmatsu, Hisako; Ohya, Hitomi; Okuno, Rumi; Mitsui, Chieko; Kawahara, Ryuji; Kameyama, Mitsuhiro; Sasaki, Mari; Shimada, Naomi; Ato, Manabu; Ohnishi, Makoto

2016-01-01

Streptococcus pyogenes (group A Streptococcus; GAS) is a widespread human pathogen and causes streptococcal toxic shock syndrome (STSS). STSS isolates have been previously shown to have high frequency mutations in the csrS/csrR (covS/covR) and/or rgg (ropB) genes, which are negative regulators of virulence. However, these mutations were found at somewhat low frequencies in emm1-genotyped isolates, the most prevalent STSS genotype. In this study, we sought to detect causal mutations of enhanced virulence in emm1 isolates lacking mutation(s) in the csrS/csrR and rgg genes. Three mutations associated with elevated virulence were found in the sic (a virulence gene) promoter, the csrR promoter, and the rocA gene (a csrR positive regulator). In vivo contribution of the sic promoter and rocA mutations to pathogenicity and lethality was confirmed in a GAS mouse model. Frequency of the sic promoter mutation was significantly higher in STSS emm1 isolates than in non-invasive STSS isolates; the rocA gene mutation frequency was not significantly different among STSS and non-STSS isolates. STSS emm1 isolates possessed a high frequency mutation in the sic promoter. Thus, this mutation may play a role in the dynamics of virulence and STSS pathogenesis. PMID:27349341

Spontaneous mutations in Streptococcus pyogenes isolates from streptococcal toxic shock syndrome patients play roles in virulence.

PubMed

Ikebe, Tadayoshi; Matsumura, Takayuki; Nihonmatsu, Hisako; Ohya, Hitomi; Okuno, Rumi; Mitsui, Chieko; Kawahara, Ryuji; Kameyama, Mitsuhiro; Sasaki, Mari; Shimada, Naomi; Ato, Manabu; Ohnishi, Makoto

2016-06-28

Streptococcus pyogenes (group A Streptococcus; GAS) is a widespread human pathogen and causes streptococcal toxic shock syndrome (STSS). STSS isolates have been previously shown to have high frequency mutations in the csrS/csrR (covS/covR) and/or rgg (ropB) genes, which are negative regulators of virulence. However, these mutations were found at somewhat low frequencies in emm1-genotyped isolates, the most prevalent STSS genotype. In this study, we sought to detect causal mutations of enhanced virulence in emm1 isolates lacking mutation(s) in the csrS/csrR and rgg genes. Three mutations associated with elevated virulence were found in the sic (a virulence gene) promoter, the csrR promoter, and the rocA gene (a csrR positive regulator). In vivo contribution of the sic promoter and rocA mutations to pathogenicity and lethality was confirmed in a GAS mouse model. Frequency of the sic promoter mutation was significantly higher in STSS emm1 isolates than in non-invasive STSS isolates; the rocA gene mutation frequency was not significantly different among STSS and non-STSS isolates. STSS emm1 isolates possessed a high frequency mutation in the sic promoter. Thus, this mutation may play a role in the dynamics of virulence and STSS pathogenesis.

Genetic diversity, anti-microbial resistance, plasmid profile and frequency of the Vi antigen in Salmonella Dublin strains isolated in Brazil.

PubMed

Vilela, F P; Frazão, M R; Rodrigues, D P; Costa, R G; Casas, M R T; Fernandes, S A; Falcão, J P; Campioni, F

2018-02-01

Salmonella Dublin is strongly adapted to cattle causing enteritis and/or systemic disease with high rates of mortality. However, it can be sporadically isolated from humans, usually causing serious disease, especially in patients with underlying chronic diseases. The aim of this study was to molecularly type S. Dublin strains isolated from humans and animals in Brazil to verify the diversity of these strains as well as to ascertain possible differences between strains isolated from humans and animals. Moreover, the presence of the capsular antigen Vi and the plasmid profile was characterized in addition to the anti-microbial resistance against 15 drugs. For this reason, 113 S. Dublin strains isolated between 1983 and 2016 from humans (83) and animals (30) in Brazil were typed by PFGE and MLVA. The presence of the capsular antigen Vi was verified by PCR, and the phenotypic expression of the capsular antigen was determined serologically. Also, a plasmid analysis for each strain was carried out. The strains studied were divided into 35 different PFGE types and 89 MLVA-types with a similarity of ≥80% and ≥17.5%, respectively. The plasmid sizes found ranged from 2 to >150 kb and none of the strains studied presented the capsular antigen Vi. Resistance or intermediate resistance was found in 23 strains (20.3%) that were resistant to ampicillin, ciprofloxacin, chloramphenicol, imipenem, nalidixic acid, piperacillin, streptomycin and/or tetracycline. The majority of the S. Dublin strains studied and isolated over a 33-year period may descend from a common subtype that has been contaminating humans and animals in Brazil and able to cause invasive disease even in the absence of the capsular antigen. The higher diversity of resistance phenotypes in human isolates, as compared with animal strains, may be a reflection of the different anti-microbial treatments used to control S. Dublin infections in humans in Brazil. © 2017 Blackwell Verlag GmbH.

Adhesion and invasion to epithelial cells and motility of extended-spectrum β-lactamase-producing Escherichia coli reveal ST131 superiority: a comparative in vitro study of extraintestinal pathogenic E. coli lineages.

PubMed

Kondratyeva, Kira; Wollman, Ayala; Gerlitz, Gabi; Navon-Venezia, Shiri

2017-09-01

Extended-spectrum β-lactamase (ESBL)-producing extraintestinal pathogenic Escherichia coli (ExPEC) sequence type ST131 is pandemic, and it is the major contributor to antibiotic resistance in E. coli. Despite its epidemiological superiority, the physiological reasons that decipher its success remain elusive. We aimed to compare the adhesion, invasion and motility potential of ST131 versus other E. coli lineages. In this in vitro comparative study, 14 ESBL-producing ExPEC community-onset bacteremia isolates were chosen from a reported clinical collection (Karfunkel D, Carmeli Y, Chmelnitsky I, Kotlovsky T, Navon-Venezia S. Eur J Clin Microbiol Infect Dis 2013;32:513-521). Isolates were divided into two groups, ST131 (n=7) and 'non-ST131', sporadic sequence types (STs) (n=7). Virulence and adhesion genes were screened by PCR in all isolates. Virotyping and serotyping were performed for ST131 isolates. Adhesion and invasion to Caco-2 epithelial cells, and motility on semi-solid agar were quantified and compared between the two groups. Fluorescence microscopy using anti-LPS E. coli antibodies was used for visualization and confirmation of adhesion and invasion. ST131 isolates belonged to the O25b:H4-B2 subclone. Two ST131 virotypes were found, A (two blaCTX-M-15 H30-Rx) and C (two blaCTX-M-15 H30-Rx and three blaCTX-M-14 H30 isolates). The average number of adhesion and virulence genes carried by ExPEC ST131 isolates and non-ST131 isolates was 5.3 and 3.7, respectively (P<0.05). Group analysis showed that ST131 surpassed non-ST131 lineages in all three physiological properties: adherence (17.1 vs 13.1 %, P<0.001), invasion (0.4 vs 0.17 %, P<0.01), and swarming motility on all media tested (P<0.05). This study demonstrates ST131 superiority that may explain its improved gut-colonization and dissemination capabilities within the host. These insights are an important step in our understanding of ST131 epidemiological success.

Molecular Epidemiology of Invasive Listeriosis due to Listeria monocytogenes in a Spanish Hospital over a Nine-Year Study Period, 2006–2014

PubMed Central

Ariza-Miguel, Jaime; Fernández-Natal, María Isabel; Soriano, Francisco; Hernández, Marta; Stessl, Beatrix; Rodríguez-Lázaro, David

2015-01-01

We investigated the pathogenicity, invasiveness, and genetic relatedness of 17 clinical Listeria monocytogenes stains isolated over a period of nine years (2006–2014). All isolates were phenotypically characterised and growth patterns were determined. The antimicrobial susceptibility of L. monocytogenes isolates was determined in E-tests. Invasion assays were performed with epithelial HeLa cells. Finally, L. monocytogenes isolates were subtyped by PFGE and MLST. All isolates had similar phenotypic characteristics (β-haemolysis and lecithinase activity), and three types of growth curve were observed. Bacterial recovery rates after invasion assays ranged from 0.09% to 7.26% (1.62 ± 0.46). MLST identified 11 sequence types (STs), and 14 PFGE profiles were obtained, indicating a high degree of genetic diversity. Genetic studies unequivocally revealed the occurrence of one outbreak of listeriosis in humans that had not previously been reported. This outbreak occurred in October 2009 and affected three patients from neighbouring towns. In conclusion, the molecular epidemiological analysis clearly revealed a cluster (three human cases, all ST1) of not previously reported listeriosis cases in northwestern Spain. Our findings indicate that molecular subtyping, in combination with epidemiological case analysis, is essential and should be implemented in routine diagnosis, to improve the tracing of the sources of outbreaks. PMID:26539467

Fusobacterium nucleatum infection of colonic cells stimulates MUC2 mucin and tumor necrosis factor alpha.

PubMed

Dharmani, Poonam; Strauss, Jaclyn; Ambrose, Christian; Allen-Vercoe, Emma; Chadee, Kris

2011-07-01

The etiology of inflammatory bowel disease is not completely known, but it is influenced by the presence of normal gut microflora as well as yet-unrecognized pathogens. The anaerobic, Gram-negative bacterial species Fusobacterium nucleatum is a common resident of the human mouth and gut and varies in its pathogenic potential. In this study, we demonstrate that highly invasive F. nucleatum isolates derived from the inflamed guts of Crohn's disease patients evoked significantly greater MUC2 and tumor necrosis factor alpha (TNF-α) gene expression than minimally invasive strains isolated from the noninflamed gut in human colonic epithelial cells and in a rat ligated colonic loop model of infection. Only live F. nucleatum induced mucin secretion and TNF-α expression in direct contact with and/or during invasion of colonic cells. In rat colons, mucin secretion was augmented in response to a highly invasive F. nucleatum isolate but was unaffected by treatment with a minimally invasive strain. Taken together, these studies reveal that F. nucleatum may represent a challenging pathogen in the etiology of gut inflammatory diseases and highlight the importance of different pathotypes of candidate bacterial species in disease pathogenesis.

Identification of Aspergillus fumigatus and Related Species by Nested PCR Targeting Ribosomal DNA Internal Transcribed Spacer Regions

PubMed Central

Zhao, Jun; Kong, Fanrong; Li, Ruoyu; Wang, Xiaohong; Wan, Zhe; Wang, Duanli

2001-01-01

Aspergillus fumigatus is the most common species that causes invasive aspergillosis. In order to identify A. fumigatus, partial ribosomal DNA (rDNA) from two to six strains of five different Aspergillus species was sequenced. By comparing sequence data from GenBank, we designed specific primer pairs targeting rDNA internal transcribed spacer (ITS) regions of A. fumigatus. A nested PCR method for identification of other A. fumigatus-related species was established by using the primers. To evaluate the specificities and sensitivities of those primers, 24 isolates of A. fumigatus and variants, 8 isolates of Aspergillus nidulans, 7 isolates of Aspergillus flavus and variants, 8 isolates of Aspergillus terreus, 9 isolates of Aspergillus niger, 1 isolate each of Aspergillus parasiticus, Aspergillus penicilloides, Aspergillus versicolor, Aspergillus wangduanlii, Aspergillus qizutongii, Aspergillus beijingensis, and Exophiala dermatitidis, 4 isolates of Candida, 4 isolates of bacteria, and human DNA were used. The nested PCR method specifically identified the A. fumigatus isolates and closely related species and showed a high degree of sensitivity. Additionally, four A. fumigatus strains that were recently isolated from our clinic were correctly identified by this method. Our results demonstrate that these primers are useful for the identification of A. fumigatus and closely related species in culture and suggest further studies for the identification of Aspergillus fumigatus species in clinical specimens. PMID:11376067

Activity of voriconazole (UK-109,496) against clinical isolates of Aspergillus species and its effectiveness in an experimental model of invasive pulmonary aspergillosis.

PubMed Central

Murphy, M; Bernard, E M; Ishimaru, T; Armstrong, D

1997-01-01

Voriconazole, a new azole antifungal agent, showed potent activity against clinical isolates of Aspergillus spp. in vitro. For A. fumigatus, the MIC range was < 0.03 to 0.5 microgram/ml and the MIC at which 90% of isolates are inhibited was 0.25 microgram/ml. In an experimental model of invasive pulmonary aspergillosis which mimics infection in humans, oral voriconazole at dosages of 30 mg/kg of body weight per day significantly delayed or prevented mortality. PMID:9056016

Ongoing outbreak of invasive listeriosis due to serotype 1/2a Listeria monocytogenes, Ancona province, Italy, January 2015 to February 2016.

PubMed

Marini, Emanuela; Magi, Gloria; Vincenzi, Chiara; Manso, Esther; Facinelli, Bruna

2016-04-28

In the first seven weeks of 2016, five serotype 1/2a Listeria monocytogenes isolates were collected from patients with invasive listeriosis in Ancona province in Italy. These strains and six 1/2a isolates identified in 2015 in the same area were typed by ERIC-PCR and PFGE. A clonal relationship, documented between the two sets of isolates, suggested a listeriosis outbreak in Ancona that started most probably in 2015. Investigation into the source of infection is still ongoing.

Invasion of Human Oral Epithelial Cells by Prevotella intermedia

PubMed Central

Dorn, Brian R.; Leung, K.-P.; Progulske-Fox, Ann

1998-01-01

Invasion of oral epithelial cells by pathogenic oral bacteria may represent an important virulence factor in the progression of periodontal disease. Here we report that a clinical isolate of Prevotella intermedia, strain 17, was found to invade a human oral epithelial cell line (KB), whereas P. intermedia 27, another clinical isolate, and P. intermedia 25611, the type strain, were not found to invade the cell line. Invasion was quantified by the recovery of viable bacteria following a standard antibiotic protection assay and observed by electron microscopy. Cytochalasin D, cycloheximide, monodansylcadaverine, and low temperature (4°C) inhibited the internalization of P. intermedia 17. Antibodies raised against P. intermedia type C fimbriae and against whole cells inhibited invasion, but the anti-type-C-fimbria antibody inhibited invasion to a greater extent than the anti-whole-cell antibody. This work provides evidence that at least one strain of P. intermedia can invade an oral epithelial cell line and that the type C fimbriae and a cytoskeletal rearrangement are required for this invasion. PMID:9826397

Decursin and decursinol from Angelica gigas inhibit the lung metastasis of murine colon carcinoma.

PubMed

Son, Seung Hwa; Park, Kwang-Kyun; Park, Sun Kyu; Kim, Young Choong; Kim, Yeong Shik; Lee, Sang-Kook; Chung, Won-Yoon

2011-07-01

The principal objective of the present study was to evaluate the antimetastatic activity of decursin and decursinol isolated from Angelica gigas. Decursin and decursinol inhibited the proliferation and invasion of CT-26 colon carcinoma cells. The expressions of matrix metalloproteinase (MMP)-2 and MMP-9 in cells and the activities in the culture medium were also reduced by decursin and decursinol treatment. In CT-26 cells, the extracellular signal-regulated kinase (ERK) inhibitor inhibited cell proliferation, invasion and MMP-9 expression, and the c-Jun N-terminal kinase (JNK) inhibitor suppressed the expression of both MMPs, as well as cell proliferation and cell invasion. The phosphatidylinositol-3 kinase (PI3K) inhibitor reduced only the expression of MMP-2. In addition, the invasion of CT-26 cells was inhibited by the treatment with anti-MMP-9 antibody, rather than anti-MMP-2 antibody. These results indicate that MMP-9 expression via ERK and JNK plays a critical role for the invasion of CT26 cells. Decursin and decursinol downregulated ERK and JNK phosphorylation. Moreover, oral administration of decursin and decursinol reduced the formation of tumor nodules in the lungs and the increase in lung weight caused by CT-26 metastases. Therefore, both decursin and decursinol may be beneficial antimetastatic agents, targeting MMPs and their upstream signaling molecules. Copyright © 2011 John Wiley & Sons, Ltd.

Human Milk Mucin 1 and Mucin 4 Inhibit Salmonella enterica Serovar Typhimurium Invasion of Human Intestinal Epithelial Cells In Vitro123

PubMed Central

Liu, Bo; Yu, Zhuoteng; Chen, Ceng; Kling, David E.; Newburg, David S.

2012-01-01

Many human milk glycans inhibit pathogen binding to host receptors and their consumption by infants is associated with reduced risk of disease. Salmonella infection is more frequent among infants than among the general population, but the incidence is lower in breast-fed babies, suggesting that human milk could contain components that inhibit Salmonella. This study aimed to test whether human milk per se inhibits Salmonella invasion of human intestinal epithelial cells in vitro and, if so, to identify the milk components responsible for inhibition. Salmonella enterica serovar Typhimurium SL1344 (SL1344) invasion of FHs 74 Int and Caco-2 cells were the models of human intestinal epithelium infection. Internalization of fluorescein-5-isothiocyanate–labeled SL1344 into intestinal cells was measured by flow cytometry to quantify infection. Human milk and its fractions inhibited infection; the inhibitory activity localized to the high molecular weight glycans. Mucin 1 and mucin 4 were isolated to homogeneity. At 150 μg/L, a typical concentration in milk, human milk mucin 1 and mucin 4 inhibited SL1344 invasion of both target cell types. These mucins inhibited SL1344 invasion of epithelial cells in a dose-dependent manner. Thus, mucins may prove useful as a basis for developing novel oral prophylactic and therapeutic agents that inhibit infant diseases caused by Salmonella and related pathogens. PMID:22718031

Neonatal Candidiasis: Epidemiology, Risk Factors, and Clinical Judgment

PubMed Central

Benjamin, Daniel K.; Stoll, Barbara J.; Gantz, Marie G.; Walsh, Michele C.; Sanchez, Pablo J.; Das, Abhik; Shankaran, Seetha; Higgins, Rosemary D.; Auten, Kathy J.; Miller, Nancy A.; Walsh, Thomas J.; Laptook, Abbot R.; Carlo, Waldemar A.; Kennedy, Kathleen A.; Finer, Neil N.; Duara, Shahnaz; Schibler, Kurt; Chapman, Rachel L.; Van Meurs, Krisa P.; Frantz, Ivan D.; Phelps, Dale L.; Poindexter, Brenda B.; Bell, Edward F.; O’Shea, T. Michael; Watterberg, Kristi L.; Goldberg, Ronald N.

2011-01-01

OBJECTIVE Invasive candidiasis is a leading cause of infection-related morbidity and mortality in extremely low-birth-weight (<1000 g) infants. We quantify risk factors predicting infection in high-risk premature infants and compare clinical judgment with a prediction model of invasive candidiasis. METHODS The study involved a prospective observational cohort of infants <1000 g birth weight at 19 centers of the NICHD Neonatal Research Network. At each sepsis evaluation, clinical information was recorded, cultures obtained, and clinicians prospectively recorded their estimate of the probability of invasive candidiasis. Two models were generated with invasive candidiasis as their outcome: 1) potentially modifiable risk factors and 2) a clinical model at time of blood culture to predict candidiasis. RESULTS Invasive candidiasis occurred in 137/1515 (9.0%) infants and was documented by positive culture from ≥ 1 of these sources: blood (n=96), cerebrospinal fluid (n=9), urine obtained by catheterization (n=52), or other sterile body fluid (n=10). Mortality was not different from infants who had positive blood culture compared to those with isolated positive urine culture. Incidence varied from 2–28% at the 13 centers enrolling ≥ 50 infants. Potentially modifiable risk factors (model 1) included central catheter, broad-spectrum antibiotics (e.g., third-generation cephalosporins), intravenous lipid emulsion, endotracheal tube, and antenatal antibiotics. The clinical prediction model (model 2) had an area under the receiver operating characteristic curve of 0.79, and was superior to clinician judgment (0.70) in predicting subsequent invasive candidiasis. Performance of clinical judgment did not vary significantly with level of training. CONCLUSION Prior antibiotics, presence of a central catheter, endotracheal tube, and center were strongly associated with invasive candidiasis. Modeling was more accurate in predicting invasive candidiasis than clinical judgment. PMID:20876174

A Comparison of Non-Typhoidal Salmonella from Humans and Food Animals Using Pulsed-Field Gel Electrophoresis and Antimicrobial Susceptibility Patterns

PubMed Central

Sandt, Carol H.; Fedorka-Cray, Paula J.; Tewari, Deepanker; Ostroff, Stephen; Joyce, Kevin; M’ikanatha, Nkuchia M.

2013-01-01

Salmonellosis is one of the most important foodborne diseases affecting humans. To characterize the relationship between Salmonella causing human infections and their food animal reservoirs, we compared pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility patterns of non-typhoidal Salmonella isolated from ill humans in Pennsylvania and from food animals before retail. Human clinical isolates were received from 2005 through 2011 during routine public health operations in Pennsylvania. Isolates from cattle, chickens, swine and turkeys were recovered during the same period from federally inspected slaughter and processing facilities in the northeastern United States. We found that subtyping Salmonella isolates by PFGE revealed differences in antimicrobial susceptibility patterns and, for human Salmonella, differences in sources and invasiveness that were not evident from serotyping alone. Sixteen of the 20 most common human Salmonella PFGE patterns were identified in Salmonella recovered from food animals. The most common human Salmonella PFGE pattern, Enteritidis pattern JEGX01.0004 (JEGX01.0003ARS), was associated with more cases of invasive salmonellosis than all other patterns. In food animals, this pattern was almost exclusively (99%) found in Salmonella recovered from chickens and was present in poultry meat in every year of the study. Enteritidis pattern JEGX01.0004 (JEGX01.0003ARS) was associated with susceptibility to all antimicrobial agents tested in 94.7% of human and 97.2% of food animal Salmonella isolates. In contrast, multidrug resistance (resistance to three or more classes of antimicrobial agents) was observed in five PFGE patterns. Typhimurium patterns JPXX01.0003 (JPXX01.0003 ARS) and JPXX01.0018 (JPXX01.0002 ARS), considered together, were associated with resistance to five or more classes of antimicrobial agents: ampicillin, chloramphenicol, streptomycin, sulfonamides and tetracycline (ACSSuT), in 92% of human and 80% of food animal Salmonella isolates. The information from our study can assist in source attribution, outbreak investigations, and tailoring of interventions to maximize their impact on prevention. PMID:24204990

Growing Industries, Growing Invasions? The Case of the Argentine Ant in Vineyards of Northern Argentina

PubMed Central

Paris, Carolina I.

2018-01-01

The invasive Argentine ant causes ecological and economic damage worldwide. In 2011, this species was reported in vineyards of Cafayate, a wine-producing town in the Andes, Argentina. While the local xeric climate is unsuitable for Argentine ants, populations could establish in association with vineyards where human activity and irrigation facilitate propagule introduction and survival. In 2013–2014, we combined extensive sampling of the area using ant-baits with monitoring of the change in land use and vineyard cultivated area over the past 15 years. Our results revealed that the species has thus far remained confined to a relatively isolated small area, owing to an effective barrier of dry shrublands surrounding the infested vineyards; yet the recent expansion of vineyard acreage in this region will soon connect this encapsulated area with the rest of the valley. When this happens, vulnerable ecosystems and the main local industry will be put at risk. This case provides a rare opportunity to study early invasion dynamics and reports, to the best of our knowledge, for the first time, the Argentine ant in high altitude agroecosystems. PMID:29382117

Growing Industries, Growing Invasions? The Case of the Argentine Ant in Vineyards of Northern Argentina.

PubMed

Schulze-Sylvester, Maria; Corronca, José A; Paris, Carolina I

2018-01-29

The invasive Argentine ant causes ecological and economic damage worldwide. In 2011, this species was reported in vineyards of Cafayate, a wine-producing town in the Andes, Argentina. While the local xeric climate is unsuitable for Argentine ants, populations could establish in association with vineyards where human activity and irrigation facilitate propagule introduction and survival. In 2013-2014, we combined extensive sampling of the area using ant-baits with monitoring of the change in land use and vineyard cultivated area over the past 15 years. Our results revealed that the species has thus far remained confined to a relatively isolated small area, owing to an effective barrier of dry shrublands surrounding the infested vineyards; yet the recent expansion of vineyard acreage in this region will soon connect this encapsulated area with the rest of the valley. When this happens, vulnerable ecosystems and the main local industry will be put at risk. This case provides a rare opportunity to study early invasion dynamics and reports, to the best of our knowledge, for the first time, the Argentine ant in high altitude agroecosystems.

Griffipavixanthone, a dimeric xanthone extracted from edible plants, inhibits tumor metastasis and proliferation via downregulation of the RAF pathway in esophageal cancer.

PubMed

Ding, Zhijie; Lao, Yuanzhi; Zhang, Hong; Fu, Wenwei; Zhu, Lunlun; Tan, Hongsheng; Xu, Hongxi

2016-01-12

Metastasis causes a large number of deaths among esophageal cancer patients. The activation of RAF family proteins elevates tumor metastasis and proliferation. In screen targeting the RAF protein, we identified that Griffipavixanthone (GPX), a dimeric xanthone isolated from Garcinia esculenta, is a B-RAF and C-RAF inhibitor against esophageal cancer cells. Using wound healing, transwell migration and matrigel invasion assays, we confirmed that GPX significantly inhibited cell migration and invasion. Furthermore, exposure to GPX rendered cell proliferation and induced G2/M cell cycle arrest. Our mechanistic study showed that GPX suppressed cancer metastasis and proliferation through downregulation of RAF-MEK-ERK cascades proteins as well as RAF mRNA levels. In a pulmonary metastasis model, the intraperitoneal injection of GPX significantly suppressed esophageal tumor metastasis and ERK protein level in vivo. In conclusion, our present study suggested that GPX could inhibit tumor migration, invasion and proliferation in vitro and in vivo, which indicated the potential of GPX for preventing and treating esophageal cancer.

Differential Activation of Acid Sphingomyelinase and Ceramide Release Determines Invasiveness of Neisseria meningitidis into Brain Endothelial Cells

PubMed Central

Simonis, Alexander; Hebling, Sabrina; Gulbins, Erich; Schneider-Schaulies, Sibylle; Schubert-Unkmeir, Alexandra

2014-01-01

The interaction with brain endothelial cells is central to the pathogenicity of Neisseria meningitidis infections. Here, we show that N. meningitidis causes transient activation of acid sphingomyelinase (ASM) followed by ceramide release in brain endothelial cells. In response to N. meningitidis infection, ASM and ceramide are displayed at the outer leaflet of the cell membrane and condense into large membrane platforms which also concentrate the ErbB2 receptor. The outer membrane protein Opc and phosphatidylcholine-specific phospholipase C that is activated upon binding of the pathogen to heparan sulfate proteoglycans, are required for N. meningitidis-mediated ASM activation. Pharmacologic or genetic ablation of ASM abrogated meningococcal internalization without affecting bacterial adherence. In accordance, the restricted invasiveness of a defined set of pathogenic isolates of the ST-11/ST-8 clonal complex into brain endothelial cells directly correlated with their restricted ability to induce ASM and ceramide release. In conclusion, ASM activation and ceramide release are essential for internalization of Opc-expressing meningococci into brain endothelial cells, and this segregates with invasiveness of N. meningitidis strains. PMID:24945304

Characterization of human invasive isolates of Listeria monocytogenes in Sweden 1986-2007.

PubMed

Parihar, Vishal Singh; Lopez-Valladares, Gloria; Danielsson-Tham, Marie-Louise; Peiris, Inoka; Helmersson, Seved; Unemo, Magnus; Andersson, Birgitta; Arneborn, Malin; Bannerman, Elizabeth; Barbuddhe, Sukdevo; Bille, Jacques; Hajdu, Lajos; Jacquet, Christine; Johansson, Christina; Löfdahl, Margareta; Möllerberg, Gunnel; Ringberg, Håkan; Rocourt, Jocelyne; Tjernberg, Ingela; Ursing, Jan; Henriques-Normark, Birgitta; Tham, Wilhelm

2008-12-01

Since 1986, 68% of the Listeria monocytogenes isolates from human cases of invasive listeriosis in Sweden are available for retrospective studies. The aim of the present study was to characterize 601 human invasive isolates of L. monocytogenes in Sweden from 1986 to 2007 by using serotyping and pulsed-field gel electrophoresis. Since 1996, serovar 4b was permanently reduced to the second or third most common serovar in human cases in Sweden. During the latter period, 2000-2007, only 13% belonged to serovar 4b and 71% to 1/2a. The dendrogram, based on pulsovars, reveals two clusters with different serovars. Cluster 1 exhibits serovars 4b and 1/2b, whereas cluster 2 consists of serovar 1/2a. Serovar 1/2a seems to be more heterogeneous than serovar 4b.

Characterization of Streptococcus pneumoniae isolates from Austrian companion animals and horses.

PubMed

Ginders, Maximilian; Leschnik, Michael; Künzel, Frank; Kampner, Doris; Mikula, Claudia; Steindl, Georg; Eichhorn, Inga; Feßler, Andrea T; Schwarz, Stefan; Spergser, Joachim; Loncaric, Igor

2017-11-14

The aim of the present study was to investigate the genetic relatedness and the antimicrobial resistance profiles of a collection of Austrian Streptococcus pneumoniae isolates from companion animals and horses. A total of 12 non-repetitive isolates presumptively identified as S. pneumoniae were obtained during routinely diagnostic activities between March 2009 and January 2017. Isolates were confirmed as S. pneumoniae by bile solubility and optochin susceptibility testing, matrix-assisted laser desorption-ionization-time of flight (MALDI-TOF) mass spectrometry and sequence analysis of a part recA and the 16S rRNA genes. Isolates were further characterized by pneumolysin polymerase chain reaction (PCR) and genotyped by multilocus sequence typing (MLST). Antimicrobial susceptibility testing was performed and resistance genes were detected by specific PCR assays. All isolates were serotyped. Four sequence types (ST) (ST36, ST3546, ST6934 and ST6937) and four serotypes (3, 19A, 19F and 23F) were detected. Two isolates from twelve displayed a multidrug-resistance pheno- and genotype. This study represents the first comprehensive investigation on characteristics of S. pneumoniae isolates recovered from Austrian companion animals and horses. The obtained results indicate that common human sero- (23F) and sequence type (ST36) implicated in causing invasive pneumococcal disease (IPD) may circulate in dogs. Isolates obtained from other examined animals seem to be host-adapted.

Epidemiology of Invasive Group A Streptococcal Infections in the United States, 2005–2012

PubMed Central

Nelson, George E.; Pondo, Tracy; Toews, Karrie-Ann; Farley, Monica M.; Lindegren, Mary Lou; Lynfield, Ruth; Aragon, Deborah; Zansky, Shelley M.; Watt, James P.; Cieslak, Paul R.; Angeles, Kathy; Harrison, Lee H.; Petit, Susan; Beall, Bernard; Van Beneden, Chris A.

2018-01-01

Background Invasive group A Streptococcus (GAS) infections are associated with significant morbidity and mortality rates. We report the epidemiology and trends of invasive GAS over 8 years of surveillance. Methods From January 2005 through December 2012, we collected data from the Centers for Disease Control and Prevention’s Active Bacterial Core surveillance, a population-based network of 10 geographically diverse US sites (2012 population, 32.8 million). We defined invasive GAS as isolation of GAS from a normally sterile site or from a wound in a patient with necrotizing fasciitis (NF) or streptococcal toxic shock syndrome (STSS). Available isolates were emm typed. We calculated rates and made age- and race-adjusted national projections using census data. Results We identified 9557 cases (3.8 cases per 100 000 persons per year) with 1116 deaths (case-fatality rate, 11.7%). The case-fatality rates for septic shock, STSS, and NF were 45%, 38%, and 29%, respectively. The annual incidence was highest among persons aged ≥65 years (9.4/100 000) or <1 year (5.3) and among blacks (4.7/100 000). National rates remained steady over 8 years of surveillance. Factors independently associated with death included increasing age, residence in a nursing home, recent surgery, septic shock, NF, meningitis, isolated bacteremia, pneumonia, emm type 1 or 3, and underlying chronic illness or immunosuppression. An estimated 10 649–13 434 cases of invasive GAS infections occur in the United States annually, resulting in 1136–1607 deaths. In a 30-valent M-protein vaccine, emm types accounted for 91% of isolates. Conclusions The burden of invasive GAS infection in the United States remains substantial. Vaccines under development could have a considerable public health impact. PMID:27105747

Virulence factors of Streptococcus pyogenes strains from women in peri-labor with invasive infections.

PubMed

Golińska, E; van der Linden, M; Więcek, G; Mikołajczyk, D; Machul, A; Samet, A; Piórkowska, A; Dorycka, M; Heczko, P B; Strus, M

2016-05-01

Invasive group A streptococcal (GAS) infections constitute an important epidemiological problem. Many cases occur in women during the postnatal period. The objective of this study was to evaluate the presence of the genes responsible for production of iron-chelating protein (perR) and superantigens (speA, speB, speC, speF, speG, speH, speI, speJ, speK, speL, speM, smeZ, and ssa) in S. pyogenes strains isolated from invasive infections in women after delivery. Furthermore, this study sought to verify whether S. pyogenes strains show special phenotypic and genotypic (sla, spy1325) characteristics that may play a decisive role in adherence to the genital tract epithelium. Moreover, the emm-types and antibiotic susceptibility were determined. We tested 30 invasive S. pyogenes strains isolated from postpartum invasive infection and 37 GAS control strains isolated from the genital tracts of asymptomatic multiparous women. The majority of the tested strains were shown to express two types of emm genes (1 and 28), though emm -12, -28, -75 and -89 were uniquely expressed in the group of strains isolated from invasive infections. A significantly higher prevalence of perR in the strains from puerperal fever was shown. Significant differences were also found between the two groups with respect to the incidence of the genes related to adherence; GAS strains originating from women with sepsis/puerperal fever showed presence of these genes less frequently than those of the control group. Although differences in frequencies of the gene coding for various superantigens were noted between the compared groups of GAS strains, they were not significant.

Diverse Colletotrichum species cause anthracnose of tea plants (Camellia sinensis (L.) O. Kuntze) in China.

PubMed

Wang, Yu-Chun; Hao, Xin-Yuan; Wang, Lu; Bin Xiao; Wang, Xin-Chao; Yang, Ya-Jun

2016-10-26

Anthracnose caused by Colletotrichum is one of the most severe diseases that can afflict Camellia sinensis. However, research on the diversity and geographical distribution of Colletotrichum in China remain limited. In this study, 106 Colletotrichum isolates were collected from diseased leaves of Ca. sinensis cultivated in the 15 main tea production provinces in China. Multi-locus phylogenetic analysis coupled with morphological identification showed that the collected isolates belonged to 11 species, including 6 known species (C. camelliae, C. cliviae, C. fioriniae, C. fructicola, C. karstii, and C. siamense), 3 new record species (C. aenigma, C. endophytica, and C. truncatum), 1 novel species (C. wuxiense), and 1 indistinguishable strain, herein described as Colletotrichum sp. Of these species, C. camelliae and C. fructicola were the dominant species causing anthracnose in Ca. sinensis. In addition, our study provided further evidence that phylogenetic analysis using a combination of ApMat and GS sequences can be used to effectively resolve the taxonomic relationships within the C. gloeosporioides species complex. Finally, pathogenicity tests suggested that C. camelliae, C. aenigma, and C. endophytica are more invasive than other species after the inoculation of the leaves of Ca. sinensis.

Diverse Colletotrichum species cause anthracnose of tea plants (Camellia sinensis (L.) O. Kuntze) in China

PubMed Central

Wang, Yu-Chun; Hao, Xin-Yuan; Wang, Lu; Bin Xiao; Wang, Xin-Chao; Yang, Ya-Jun

2016-01-01

Anthracnose caused by Colletotrichum is one of the most severe diseases that can afflict Camellia sinensis. However, research on the diversity and geographical distribution of Colletotrichum in China remain limited. In this study, 106 Colletotrichum isolates were collected from diseased leaves of Ca. sinensis cultivated in the 15 main tea production provinces in China. Multi-locus phylogenetic analysis coupled with morphological identification showed that the collected isolates belonged to 11 species, including 6 known species (C. camelliae, C. cliviae, C. fioriniae, C. fructicola, C. karstii, and C. siamense), 3 new record species (C. aenigma, C. endophytica, and C. truncatum), 1 novel species (C. wuxiense), and 1 indistinguishable strain, herein described as Colletotrichum sp. Of these species, C. camelliae and C. fructicola were the dominant species causing anthracnose in Ca. sinensis. In addition, our study provided further evidence that phylogenetic analysis using a combination of ApMat and GS sequences can be used to effectively resolve the taxonomic relationships within the C. gloeosporioides species complex. Finally, pathogenicity tests suggested that C. camelliae, C. aenigma, and C. endophytica are more invasive than other species after the inoculation of the leaves of Ca. sinensis. PMID:27782129

Antibiotic non-susceptibility among Streptococcus pneumoniae and Haemophilus influenzae isolates identified in African cohorts: a meta-analysis of three decades of published studies.

PubMed

Ginsburg, Amy Sarah; Tinkham, Laura; Riley, Katherine; Kay, Noa A; Klugman, Keith P; Gill, Christopher J

2013-12-01

Management of community-acquired pneumonia caused by Streptococcus pneumoniae and Haemophilus influenzae type B (Hib) can be complicated by emerging antimicrobial non-susceptibility. We conducted a meta-analysis to examine the antibiotic susceptibility of community-acquired invasive infections with S. pneumoniae and Hib in Africa from 1978 to 2011. With the notable exceptions of widespread trimethoprim/sulfamethoxazole (SXT) and tetracycline non-susceptibility, the majority of pneumococci remain susceptible to ampicillin/amoxicillin. However, 23.8% of pneumococcal meningitis isolates are non-susceptible to penicillin. Similarly, Hib isolates show non-susceptibility to SXT, tetracycline, erythromycin and chloramphenicol. β-Lactamase production among Hib isolates is increasing, a new observation for Africa, but is mitigated somewhat by Hib vaccination scale-up. In summary, pneumococcal susceptibility to amoxicillin remains high throughout Africa, and amoxicillin can be effectively and safely used as first-line treatment for childhood pneumonia. Data support first-line treatment of bacterial meningitis with ceftriaxone or cefotaxime. Copyright © 2013 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Rise of multidrug-resistant non-vaccine serotype 15A Streptococcus pneumoniae in the United Kingdom, 2001 to 2014

PubMed Central

Sheppard, Carmen; Fry, Norman K.; Mushtaq, Shazad; Woodford, Neil; Reynolds, Rosy; Janes, Regina; Pike, Rachel; Hill, Robert; Kimuli, Maimuna; Staves, Peter; Doumith, Michel; Harrison, Timothy; Livermore, David M

2016-01-01

Conjugate vaccines have reduced pneumococcal disease in vaccinated children and unvaccinated adults, but non-vaccine serotypes are of concern, particularly if antibiotic resistant. We reviewed Streptococcus pneumoniae collected via: (i) the British Society for Antimicrobial Chemotherapy (BSAC) surveillances from 2001–2014; (ii) Public Health England’s (PHE) invasive isolate surveillance from 2005–2014 and (iii) referral to PHE for resistance investigation from 2005–2014. Serotype 15A increased in all series, with many representatives showing triple resistance to macrolides, tetracyclines and penicillin. 15A was consistently among the 10 most prevalent serotypes from 2011 in PHE and BSAC invasive isolate/bacteraemia surveillance but never previously; 26–33% of these invasive 15A isolates had triple resistance. BSAC respiratory isolates were only serotyped in 2013/14 and 2014/15 (October to September); 15A was most prevalent serotype in both periods, comprising 9–11% of isolates, 38–48% of them with triple resistance. Serotype 15A represented 0–4% of S. pneumoniae referred to PHE for reference investigation annually until 2008 but rose to 29% (2013) and 32% (2014). Almost all multidrug-resistant 15A isolates were sequence type (ST) 63 variants, whereas susceptible 15A isolates were clonally diverse. The rise of serotype 15A suggests that pneumococcal conjugate vaccines will need ongoing adaptation. PMID:28006650

Genotypic and phenotypic characterization of invasive neonatal Escherichia coli clinical isolates.

PubMed

Shakir, Salika Mehreen; Goldbeck, Jessica Marie; Robison, Denise; Eckerd, Annette Marie; Chavez-Bueno, Susana

2014-11-01

The objective of this study was to describe the clinical characteristics of neonates with Escherichia coli bacteremia and the antibiotic resistance pattern of the bacterial isolates. We assessed the isolates' genetic relatedness and virulence phenotypic characteristics in vitro. A total of 24 neonates with E. coli bacteremia were identified prospectively in a tertiary-care hospital. Clinical and antibiotic resistance data were investigated. The E. coli isolates were analyzed by multilocus sequence typing (MLST); the presence of the K1 capsule and their ability to invade intestinal epithelial cells were also assessed. Most newborns were very low birth weight infants. Overall, 75% of the isolates were ampicillin resistant and 17% were gentamicin and tobramycin nonsusceptible. MLST determined sequence types 95 and 131 (ST95 and ST131) predominated, with ST131 becoming significantly more prevalent recently. The K1 capsule was present in 50% of the isolates. ST131 isolates and those producing bacteremia in newborns younger than 7 days showed a highly invasive phenotype. Resistance to antibiotics currently used empirically to treat newborns is present in bacteremia-producing E. coli. Clonal spread among newborns of multidrug-resistant E. coli is possible; therefore, continued surveillance is needed. Identification of additional virulence factors associated with increased invasion in neonatal E. coli strains is important and further studies are warranted. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

In vitro susceptibility of Candida spp. to fluconazole, itraconazole and voriconazole and the correlation between triazoles susceptibility: Results from a five-year study.

PubMed

Lei, J; Xu, J; Wang, T

2018-06-01

Candida spp. is a common cause of invasive fungal disease. The aim of this study was to examine the susceptibility of Candida spp. to fluconazole, itraconazole and voriconazole and explore the correlation between triazoles susceptibility. The antifungal susceptibility in the present study was measured by ATB Fungus 3 method, and the potential relationship was examined by obtaining the correlation of measured minimal inhibitory concentrations (MICs) of Candida spp. isolates. A total of 2099 clinical isolates of Candida spp. from 1441 patients were analyzed. The organisms included 1435 isolates of Candida albicans, 207 isolates of Candida glabrata, 65 isolates of Candida parapsilosis, 31 isolates of Candida krusei, 268 isolates of Candida tropicalis. Voriconazole and itraconazole were more active than fluconazole and against Candida spp. in vitro. The fluconazole, itraconazole and voriconazole MIC 90 (MIC for 90% of the isolates) for all Candida spp. isolates was 4mg/L, 1mg/L and 0.25mg/L, respectively. There was a moderate correlation between the fluconazole MIC s for Candida spp. isolates and this for voriconazole (R 2 =0.475; P<0.01) and itraconazole (R 2 =0.431; P<0.01). Voriconazole MICs for the Candida spp. isolates also correlated with those for itraconazole (R 2 =0.401; P<0.01). These observations suggest that the in vitro susceptibility of Candida spp. to fluconazole, itraconazole and voriconazole exhibits a moderate correlation. Published by Elsevier Masson SAS.

Genome characterization and population genetic structure of the zoonotic pathogen, Streptococcus canis

PubMed Central

2012-01-01

Background Streptococcus canis is an important opportunistic pathogen of dogs and cats that can also infect a wide range of additional mammals including cows where it can cause mastitis. It is also an emerging human pathogen. Results Here we provide characterization of the first genome sequence for this species, strain FSL S3-227 (milk isolate from a cow with an intra-mammary infection). A diverse array of putative virulence factors was encoded by the S. canis FSL S3-227 genome. Approximately 75% of these gene sequences were homologous to known Streptococcal virulence factors involved in invasion, evasion, and colonization. Present in the genome are multiple potentially mobile genetic elements (MGEs) [plasmid, phage, integrative conjugative element (ICE)] and comparison to other species provided convincing evidence for lateral gene transfer (LGT) between S. canis and two additional bovine mastitis causing pathogens (Streptococcus agalactiae, and Streptococcus dysgalactiae subsp. dysgalactiae), with this transfer possibly contributing to host adaptation. Population structure among isolates obtained from Europe and USA [bovine = 56, canine = 26, and feline = 1] was explored. Ribotyping of all isolates and multi locus sequence typing (MLST) of a subset of the isolates (n = 45) detected significant differentiation between bovine and canine isolates (Fisher exact test: P = 0.0000 [ribotypes], P = 0.0030 [sequence types]), suggesting possible host adaptation of some genotypes. Concurrently, the ancestral clonal complex (54% of isolates) occurred in many tissue types, all hosts, and all geographic locations suggesting the possibility of a wide and diverse niche. Conclusion This study provides evidence highlighting the importance of LGT in the evolution of the bacteria S. canis, specifically, its possible role in host adaptation and acquisition of virulence factors. Furthermore, recent LGT detected between S. canis and human bacteria (Streptococcus urinalis) is cause for concern, as it highlights the possibility for continued acquisition of human virulence factors for this emerging zoonotic pathogen. PMID:23244770

Evaluating the Interacting Influences of Pollination, Seed Predation, Invasive Species and Isolation on Reproductive Success in a Threatened Alpine Plant

PubMed Central

Krushelnycky, Paul D.

2014-01-01

Reproduction in rare plants may be influenced and limited by a complex combination of factors. External threats such as invasive species and landscape characteristics such as isolation may impinge on both pollination and seed predation dynamics, which in turn can strongly affect reproduction. I assessed how patterns in floral visitation, seed predation, invasive ant presence, and plant isolation influenced one another and ultimately affected viable seed production in Haleakalā silverswords (Argyroxiphium sandwicense subsp. macrocephalum) of Hawai’i. Floral visitation was dominated by endemic Hylaeus bees, and patterns of visitation were influenced by floral display size and number of plants clustered together, but not by floral herbivory or nearest flowering neighbor distance. There was also some indication that Argentine ant presence impacted floral visitation, but contradictory evidence and limitations of the study design make this result uncertain. Degree of seed predation was associated only with plant isolation, with the two main herbivores partitioning resources such that one preferentially attacked isolated plants while the other attacked clumped plants; total seed predation was greater in more isolated plants. Net viable seed production was highly variable among individuals (0–55% seed set), and was affected mainly by nearest neighbor distance, apparently owing to low cross-pollination among plants separated by even short distances (>10–20 m). This isolation effect dominated net seed set, with no apparent influence from floral visitation rates, percent seed predation, or invasive ant presence. The measured steep decline in seed set with isolation distance may not be typical of the entire silversword range, and may indicate that pollinators in addition to Hylaeus bees could be important for greater gene flow. Management aimed at maintaining or maximizing silversword reproduction should focus on the spatial context of field populations and outplanting efforts, as well as on conserving the widest possible range of pollinator taxa. PMID:24551195

Evaluating the interacting influences of pollination, seed predation, invasive species and isolation on reproductive success in a threatened alpine plant.

PubMed

Krushelnycky, Paul D

2014-01-01

Reproduction in rare plants may be influenced and limited by a complex combination of factors. External threats such as invasive species and landscape characteristics such as isolation may impinge on both pollination and seed predation dynamics, which in turn can strongly affect reproduction. I assessed how patterns in floral visitation, seed predation, invasive ant presence, and plant isolation influenced one another and ultimately affected viable seed production in Haleakalā silverswords (Argyroxiphium sandwicense subsp. macrocephalum) of Hawai'i. Floral visitation was dominated by endemic Hylaeus bees, and patterns of visitation were influenced by floral display size and number of plants clustered together, but not by floral herbivory or nearest flowering neighbor distance. There was also some indication that Argentine ant presence impacted floral visitation, but contradictory evidence and limitations of the study design make this result uncertain. Degree of seed predation was associated only with plant isolation, with the two main herbivores partitioning resources such that one preferentially attacked isolated plants while the other attacked clumped plants; total seed predation was greater in more isolated plants. Net viable seed production was highly variable among individuals (0-55% seed set), and was affected mainly by nearest neighbor distance, apparently owing to low cross-pollination among plants separated by even short distances (>10-20 m). This isolation effect dominated net seed set, with no apparent influence from floral visitation rates, percent seed predation, or invasive ant presence. The measured steep decline in seed set with isolation distance may not be typical of the entire silversword range, and may indicate that pollinators in addition to Hylaeus bees could be important for greater gene flow. Management aimed at maintaining or maximizing silversword reproduction should focus on the spatial context of field populations and outplanting efforts, as well as on conserving the widest possible range of pollinator taxa.

Evaluation of approaches to monitor Staphylococcus aureus virulence factor expression during human disease.

PubMed

Rozemeijer, Wouter; Fink, Pamela; Rojas, Eduardo; Jones, C Hal; Pavliakova, Danka; Giardina, Peter; Murphy, Ellen; Liberator, Paul; Jiang, Qin; Girgenti, Douglas; Peters, Remco P H; Savelkoul, Paul H M; Jansen, Kathrin U; Anderson, Annaliesa S; Kluytmans, Jan

2015-01-01

Staphylococcus aureus is a versatile pathogen of medical significance, using multiple virulence factors to cause disease. A prophylactic S. aureus 4-antigen (SA4Ag) vaccine comprising capsular polysaccharide (types 5 and 8) conjugates, clumping factor A (ClfA) and manganese transporter C (MntC) is under development. This study was designed to characterize S. aureus isolates recovered from infected patients and also to investigate approaches for examining expression of S. aureus vaccine candidates and the host response during human infection. Confirmation of antigen expression in different disease states is important to support the inclusion of these antigens in a prophylactic vaccine. Hospitalized patients with diagnosed S. aureus wound (27) or bloodstream (24) infections were enrolled. Invasive and nasal carriage S. aureus isolates were recovered and characterized for genotypic diversity. S. aureus antigen expression was evaluated directly by real-time, quantitative, reverse-transcriptase PCR (qRT-PCR) analysis and indirectly by serology using a competitive Luminex immunoassay. Study isolates were genotypically diverse and all had the genes encoding the antigens present in the SA4Ag vaccine. S. aureus nasal carriage was detected in 55% of patients, and in those subjects 64% of the carriage isolates matched the invasive strain. In swab samples with detectable S. aureus triosephosphate isomerase housekeeping gene expression, RNA transcripts encoding the S. aureus virulence factors ClfA, MntC, and capsule polysaccharide were detected by qRT-PCR. Antigen expression was indirectly confirmed by increases in antibody titer during the course of infection from acute to convalescent phase. Demonstration of bacterial transcript expression together with immunological response to the SA4Ag antigens in a clinically relevant patient population provides support for inclusion of these antigens in a prophylactic vaccine.

Community carriage of ESBL-producing Escherichia coli is associated with strains of low pathogenicity: a Swedish nationwide study.

PubMed

Ny, Sofia; Löfmark, Sonja; Börjesson, Stefan; Englund, Stina; Ringman, Maj; Bergström, Jakob; Nauclér, Pontus; Giske, Christian G; Byfors, Sara

2017-02-01

Community carriage of ESBL-producing Escherichia coli (EPE) is common worldwide and there is a need to understand the connection between carriage and infection. We compared the molecular characteristics of EPE among Swedish community carriers with those of EPE causing invasive infections. We collected 2134 faecal samples from randomly selected Swedish inhabitants and examined them for the presence of EPE. All participating volunteers answered a questionnaire about putative risk factors for EPE carriage. Suspected EPE isolates (n = 418) from patients with bloodstream infection (BSI) were collected from Swedish laboratories. Isolates were genotypically and phenotypically characterized. Our results show that the EPE population found in carriers generally had lower pathogenicity compared with the isolates from BSIs, since carriers had a lower proportion of E. coli belonging to phylogroup B2, ST131 and ST131 subclone H30-Rx. Isolates from carriers also had lower levels of multiresistance. The Swedish carriage rate of EPE was 4.7% (101/2134) among healthy volunteers. Risk factors associated with carriage were travel to countries in Asia (OR = 3.6, 95% CI = 1.4-9.2) and Africa (OR = 3.6, 95% CI = 1.7-7.7) and a diet without pork (OR = 0.5, 95% CI = 0.3-0.8 for pork eaters). E. coli host factors previously associated with higher pathogenicity were all more common in BSIs compared with carriers. This indicates that the risk of invasive infection with EPE may be relatively modest in many community carriers and that EPE carriage of high-risk strains should be the focus of attention for prevention. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.

Multilocus variable-number tandem-repeat analysis of clinical isolates of Aspergillus flavus from Iran reveals the first cases of Aspergillus minisclerotigenes associated with human infection

PubMed Central

2014-01-01

Background Aspergillus flavus is intensively studied for its role in infecting crop plants and contaminating produce with aflatoxin, but its role as a human pathogen is less well understood. In parts of the Middle East and India, A. flavus surpasses A. fumigatus as a cause of invasive aspergillosis and is a significant cause of cutaneous, sinus, nasal and nail infections. Methods A collection of 45 clinical and 10 environmental A. flavus isolates from Iran were analysed using Variable-Number Tandem-Repeat (VNTR) markers with MICROSAT and goeBURST to determine their genetic diversity and their relatedness to clinical and environmental A. flavus isolates from Australia. Phylogeny was assessed using partial β-tubulin and calmodulin gene sequencing, and mating type was determined by PCR. Antifungal susceptibility testing was performed on selected isolates using a reference microbroth dilution method. Results There was considerable diversity in the A. flavus collection, with no segregation on goeBURST networks according to source or geographic location. Three Iranian isolates, two from sinus infections and one from a paranasal infection grouped with Aspergillus minisclerotigenes, and all produced B and G aflatoxin. Phylogenic analysis using partial β-tubulin and calmodulin sequencing confirmed two of these as A. minisclerotigenes, while the third could not be differentiated from A. flavus and related species within Aspergillus section flavi. Based on epidemiological cut-off values, the A. minisclerotigens and A. flavus isolates tested were susceptible to commonly used antifungal drugs. Conclusions This is the first report of human infection due to A. minisclerotigenes, and it raises the possiblity that other species within Aspergillus section flavi may also cause clinical disease. Clinical isolates of A. flavus from Iran are not distinct from Australian isolates, indicating local environmental, climatic or host features, rather than fungal features, govern the high incidence of A. flavus infection in this region. The results of this study have important implications for biological control strategies that aim to reduce aflatoxin by the introduction of non-toxigenic strains, as potentially any strain of A. flavus, and closely related species like A. minisclerotigenes, might be capable of human infection. PMID:24986045

[Clinicopathologic study of invasive fungal rhinosinusitis caused by Aspergillus and Mucorales].

PubMed

He, Chun-yan; Piao, Ying-shi; Tian, Cheng; Li, Li-li; Liu, Hong-gang

2012-10-01

To compare the differences in clinicopathologic features of invasive fungal rhinosinusitis caused by Aspergillus and Mucorales, and to discuss the pathogenesis of tissue injury induced by these two kinds of fungi. The clinical and pathologic features of 19 patients with invasive fungal rhinosinusitis due to Aspergillus (group A) and 16 patients with invasive fungal rhinosinusitis due to Mucorales (group M) were retrospectively reviewed. HE, PAS and GMS stains were performed on all the paraffin-embedded tissues. The diagnosis was confirmed by histologic examination and microbiological culture results. Amongst the group A patients, the clinical course was acute in 4 cases and chronic in 15 cases. Thirteen cases had underlying predisposing conditions, including diabetes (number = 4), malignant tumor (number = 5), history of trauma (number = 1) and radical maxillary sinus surgery (number = 3). Follow-up information was available in 13 patients. Seven of them died, 4 due to fungal encephalopathy and 3 due to underlying diseases. Amongst the group M patients, the clinical course was acute in 14 cases and chronic in 2 cases. Fourteen cases had underlying predisposing conditions, including diabetes (number = 8), malignant tumor (number = 5) and history of wisdom tooth extraction (number = 1). Follow-up information was available in 14 patients. Four of them died of fungal encephalopathy. There was significant difference in clinical onset between the two groups (P = 0.01). There was however no difference in terms of underlying predisposing conditions and disease mortality. Histologically, the microorganisms in group A patients formed fungal masses and attached to the mucosal surface, resulting in necrotic bands (11/19). Epithelioid granulomas were conspicuous but multinucleated giant cells were relatively rare. Deep-seated necrosis, granulomatous inflammation against fungal organisms (3/19) and vasculitis with thrombosis (4/19) were not common. On the other hand, large areas of geographic necrosis involving deep-seated tissue could be seen in group M patients (13/16). Isolated multinucleated giant cells were commonly seen. Granulomatous inflammation against fungal organisms were identified (16/16). Vasculitis and thrombosis were also observed (10/16). The invasiveness of Mucorales is remarkable; and when it causes invasive fungal rhinosinusitis, the clinical course is often acute and large areas of tissue necrosis can be seen. The invasiveness of Aspergillus in tissue is relatively mild. Granulomas are more common and the disease often runs a chronic clinical course. There is however no significant difference in long-term mortality. The pathogenesis may be related to the different components of the fungi.

QUANTIFYING AND MODELING THE RISK OF DISTURBANCE TO ECOSYSTEMS CAUSED BY INVASIVE SPECIES

EPA Science Inventory

Invasive species are biological pollutants that threaten ecosystem health. Identifying the mechanisms of invasive and developing predictive models of invasion will be critical to developing risk management strategies for limiting the economic and environmental damage caused by i...

Using whole genome sequencing to identify resistance determinants and predict antimicrobial resistance phenotypes for year 2015 invasive pneumococcal disease isolates recovered in the United States.

PubMed

Metcalf, B J; Chochua, S; Gertz, R E; Li, Z; Walker, H; Tran, T; Hawkins, P A; Glennen, A; Lynfield, R; Li, Y; McGee, L; Beall, B

2016-12-01

Our whole genome sequence (WGS) pipeline was assessed for accurate prediction of antimicrobial phenotypes. For 2316 invasive pneumococcal isolates recovered during 2015 we compared WGS pipeline data to broth dilution testing (BDT) for 18 antimicrobials. For 11 antimicrobials categorical discrepancies were assigned when WGS-predicted MICs and BDT MICs predicted different categorizations for susceptibility, intermediate resistance or resistance, ranging from 0.9% (tetracycline) to 2.9% (amoxicillin). For β-lactam antibiotics, the occurrence of at least four-fold differences in MIC ranged from 0.2% (meropenem) to 1.0% (penicillin), although phenotypic retesting resolved 25%-78% of these discrepancies. Non-susceptibility to penicillin, predicted by penicillin-binding protein types, was 2.7% (non-meningitis criteria) and 23.8% (meningitis criteria). Other common resistance determinants included mef (475 isolates), ermB (191 isolates), ermB + mef (48 isolates), tetM (261 isolates) and cat (51 isolates). Additional accessory resistance genes (tetS, tet32, aphA-3, sat4) were rarely detected (one to three isolates). Rare core genome mutations conferring erythromycin-resistance included a two-codon rplD insertion (rplD69-KG-70) and the 23S rRNA A2061G substitution (six isolates). Intermediate cotrimoxazole-resistance was associated with one or two codon insertions within folP (238 isolates) or the folA I100L substitution (38 isolates), whereas full cotrimoxazole-resistance was attributed to alterations in both genes (172 isolates). The two levofloxacin-resistant isolates contained parC and/or gyrA mutations. Of 11 remaining isolates with moderately elevated MICs to both ciprofloxacin and levofloxacin, seven contained parC or gyrA mutations. The two rifampin-resistant isolates contained rpoB mutations. WGS-based antimicrobial phenotype prediction was an informative alternative to BDT for invasive pneumococci. Published by Elsevier Ltd.

Macrophage invasion does not contribute to muscle membrane injury during inflammation

NASA Technical Reports Server (NTRS)

Tidball, J. G.; Berchenko, E.; Frenette, J.

1999-01-01

Previous observations have shown that neutrophil invasion precedes macrophage invasion during muscle inflammation and that peak muscle injury is observed at the peak of ED1+ macrophage invasion. We tested the hypothesis that neutrophil invasion causes subsequent invasion by ED1+ macrophages and that ED1+ macrophages then contribute significantly to muscle membrane injury during modified muscle use. Rat hindlimbs were unloaded for 10 days followed by reloading by normal ambulation to induce inflammation. Membrane injury was measured by assaying Evans blue-bound serum protein influx through membrane lesions. Muscle neutrophil populations increased significantly during the first 2 h of reloading but ED1+ macrophages did not increase until 24 h. Neutrophil invasion was uncoupled from subsequent macrophage invasion by reloading rat hindlimbs for 2 h to cause neutrophil invasion, followed by resuspension for hours 2-24. This produced similar increases in neutrophil concentration as measured in muscles continuously reloaded for 24 h without causing an increase in macrophages. However, resuspension did not reduce the extent of muscle damage compared with that occurring in muscles that were reloaded continuously for 24 h. Thus, muscle invasion by neutrophils is not sufficient to cause invasion by ED1+ macrophages. In addition, muscle membrane injury that occurs during reloading is independent of invasion by ED1+ macrophages.

Epidemiology and outcomes of invasive candidiasis due to non-albicans species of Candida in 2,496 patients: data from the Prospective Antifungal Therapy (PATH) registry 2004-2008.

PubMed

Pfaller, Michael A; Andes, David R; Diekema, Daniel J; Horn, David L; Reboli, Annette C; Rotstein, Coleman; Franks, Billy; Azie, Nkechi E

2014-01-01

This analysis describes the epidemiology and outcomes of invasive candidiasis caused by non-albicans species of Candida in patients enrolled in the Prospective Antifungal Therapy Alliance (PATH Alliance) registry from 2004 to 2008. A total of 2,496 patients with non-albicans species of Candida isolates were identified. The identified species were C. glabrata (46.4%), C. parapsilosis (24.7%), C. tropicalis (13.9%), C. krusei (5.5%), C. lusitaniae (1.6%), C. dubliniensis (1.5%) and C. guilliermondii (0.4%); 111 infections involved two or more species of Candida (4.4%). Non-albicans species accounted for more than 50% of all cases of invasive candidiasis in 15 of the 24 sites (62.5%) that contributed more than one case to the survey. Among solid organ transplant recipients, patients with non-transplant surgery, and patients with solid tumors, the most prevalent non-albicans species was C. glabrata at 63.7%, 48.0%, and 53.8%, respectively. In 1,883 patients receiving antifungal therapy on day 3, fluconazole (30.5%) and echinocandins (47.5%) were the most frequently administered monotherapies. Among the 15 reported species, 90-day survival was highest for patients infected with either C. parapsilosis (70.7%) or C. lusitaniae (74.5%) and lowest for patients infected with an unknown species (46.7%) or two or more species (53.2%). In conclusion, this study expands the current knowledge of the epidemiology and outcomes of invasive candidiasis caused by non-albicans species of Candida in North America. The variability in species distribution in these centers underscores the importance of local epidemiology in guiding the selection of antifungal therapy.

Identification of a high-virulence clone of type III Streptococcus agalactiae (group B Streptococcus) causing invasive neonatal disease.

PubMed

Musser, J M; Mattingly, S J; Quentin, R; Goudeau, A; Selander, R K

1989-06-01

Chromosomal genotypes of 128 isolates of six serotypes (Ia, Ib, Ic, II, Ic/II, and III) of Streptococcus agalactiae (group B Streptococcus) recovered predominantly from human infants in the United States were characterized by an analysis of electrophoretically demonstrable allelic profiles at 11 metabolic enzyme loci. Nineteen distinctive electrophoretic types (ETs), representing multilocus clonal genotypes, were identified. Mean genetic diversity per locus among ETs of isolates of the same serotype was, on average, nearly equal to that in all 19 ETs. Cluster analysis of the ETs revealed two primary phylogenetic divisions at a genetic distance of 0.65. A single clone (ET 1) represented by 40 isolates expressing type III antigen formed division I. Division II was composed of 18 ETs in three major lineages diverging from one another at distances greater than 0.35 and included strains of all six antigenic classes. The type III organisms in division I produce more extracellular neuraminidase and apparently are more virulent than the type III strains in division II, which are related to strains of other serotypes that cause disease much less frequently. The existence of this unusually virulent clone accounts, in major part, for the high morbidity and mortality associated with infection by type III organisms.

The Salmonella dublin virulence plasmid mediates systemic but not enteric phases of salmonellosis in cattle.

PubMed Central

Wallis, T S; Paulin, S M; Plested, J S; Watson, P R; Jones, P W

1995-01-01

Plasmid-bearing and plasmid-free isolates and a plasmid-cured strain of Salmonella dublin were compared for virulence in calves. The plasmid-bearing strains were highly virulent, causing severe enteric and systemic disease with high mortality. In contrast, the plasmid-free strains caused diarrhea but only low mortality. The infection kinetics of a wild-type and a derivative plasmid-cured strain were compared. Both strains were isolated in high numbers from intestinal sites at 3 and 6 days after oral challenge and were isolated at comparable frequencies from systemic sites at 3 days, but not at 6 days, when the wild-type strain was predominant. The strains were equally invasive in intestinal epithelia with and without Peyer's patch and elicited comparable secretory and inflammatory responses and intestinal pathology in ligated ileal loops. The effect of the virulence plasmid on growth kinetics and on the outer membrane protein profile was assessed in an in vivo growth chamber. The virulence plasmid did not influence either extracellular growth or the expression of major outer membrane proteins. These observations demonstrate that the virulence plasmid is not involved in either the enteric phase of infection or the systemic dissemination of S. dublin but probably mediates the persistence of S. dublin at systemic sites. PMID:7790094

[Epidemiology, clinical and microbiological characteristics of invasive streptococcal infections in Turkey, 2010-2011].

PubMed

Topkaya, Aynur Eren; Balıkcı, Ahmet; Aydın, Faruk; Hasçelik, Gülşen; Kayman, Tuba; Kesli, Recep; Aydemir, Söhret; Akyar, Işın; Gökalp, Aslı; Dündar, Günnur; Gürler, Nezahat; Perçin, Duygu; Fındık, Duygu; Avunduk, Haluk; Bayraktar, Banu

2014-01-01

A one-year active surveillance study was conducted to investigate the epidemiological and microbiological characteristics of invasive group A streptococci (GAS) infections in Turkey and to provide data for the establishment of national preventive strategies related to invasive GAS infections. A total of 46 clinical microbiology laboratories from 12 different regions of Turkey (Istanbul; Eastern and Western Marmara; Eastern and Western Blacksea; Aegean; Mediterranean; Western, Central, Northeastern, Middle-eastern and Southeastern Anatolia) participated in the study. Accordingly, GAS strains isolated from sterile body sites (blood, cerebrospinal, synovial, pleural, peritoneal, pericardial fluids) in the study centers between June 2010-June 2011, were sent to Maltepe University Hospital Clinical Microbiology Laboratory for microbiological confirmation and further analysis. The isolates were identified by conventional methods, and for serotyping, opacity factor (OF) and T protein types were investigated. For genotyping GAS lysate preparation, emm gene amplification and sequencing were performed by using the protocols recommended by Centers for Disease Control and Prevention. A total of 65 invasive GAS strains were isolated in 15 of the participant centers, during the study period. The rate of invasive GAS isolation exhibited regional variation, with the highest rates in the Eastern Blacksea (Trabzon, n= 19), followed by Istanbul (n= 17) and Western Anatolia (Ankara, Konya, n= 14). Of the patients with invasive GAS infection 33 were female, 32 were male, with the age range of 0-89 years. GAS strains were most commonly isolated from soft tissue specimens (n= 18), followed by abscess material (n= 10), sterile body fluids (n= 8) and blood (n= 7) samples. Serotyping revealed that 55% (36/65) of the strains were OF positive, and the majority of T protein was polygroup T (n= 20), followed by U (n= 14), B (n= 5), X (n= 3) and Y (n= 2). T protein was not detected in 22 isolates. The strains were found to have 17 different emm types;emm1 (n= 13), emm4 (n= 6), emm6 (n= 6), emm12 (n= 6), emm24 (n= 4), emm14 (n= 3) and emm28 (n= 3). Nine of the strains could not be typed by sequencing. The correlation between emm typing and serotyping was detected as 58%. It was observed that 26-valent vaccines included 70.5% of the invasive GAS strains included in this study. Our study provided initial data concerning the epidemiological properties of invasive GAS infections and characterization of GAS strains in Turkey. The incidence of invasive GAS infections is low in our country. Although immunization programme by 26-valent GAS vaccine is not currently an urgent public health issue for our country, the results of this study indicated that emm types 4 and 24 should better be included in such a vaccine to be used in Turkey. Additionally, since epidemiological features of GAS infections and the microbiological characteristics of the strains can vary by time, for the diagnosis of invasive streptococcal infections and to take the necessary preventive measures, epidemiological studies should be conducted repeatedly.

Technical Insights into Highly Sensitive Isolation and Molecular Characterization of Fixed and Live Circulating Tumor Cells for Early Detection of Tumor Invasion.

PubMed

Laget, Sophie; Broncy, Lucile; Hormigos, Katia; Dhingra, Dalia M; BenMohamed, Fatima; Capiod, Thierry; Osteras, Magne; Farinelli, Laurent; Jackson, Stephen; Paterlini-Bréchot, Patrizia

2017-01-01

Circulating Tumor Cells (CTC) and Circulating Tumor Microemboli (CTM) are Circulating Rare Cells (CRC) which herald tumor invasion and are expected to provide an opportunity to improve the management of cancer patients. An unsolved technical issue in the CTC field is how to obtain highly sensitive and unbiased collection of these fragile and heterogeneous cells, in both live and fixed form, for their molecular study when they are extremely rare, particularly at the beginning of the invasion process. We report on a new protocol to enrich from blood live CTC using ISET® (Isolation by SizE of Tumor/Trophoblastic Cells), an open system originally developed for marker-independent isolation of fixed tumor cells. We have assessed the impact of our new enrichment method on live tumor cells antigen expression, cytoskeleton structure, cell viability and ability to expand in culture. We have also explored the ISET® in vitro performance to collect intact fixed and live cancer cells by using spiking analyses with extremely low number of fluorescent cultured cells. We describe results consistently showing the feasibility of isolating fixed and live tumor cells with a Lower Limit of Detection (LLOD) of one cancer cell per 10 mL of blood and a sensitivity at LLOD ranging from 83 to 100%. This very high sensitivity threshold can be maintained when plasma is collected before tumor cells isolation. Finally, we have performed a comparative next generation sequencing (NGS) analysis of tumor cells before and after isolation from blood and culture. We established the feasibility of NGS analysis of single live and fixed tumor cells enriched from blood by our system. This study provides new protocols for detection and characterization of CTC collected from blood at the very early steps of tumor invasion.

Escherichia coli isolates from inflammatory bowel diseases patients survive in macrophages and activate NLRP3 inflammasome.

PubMed

De la Fuente, Marjorie; Franchi, Luigi; Araya, Daniela; Díaz-Jiménez, David; Olivares, Mauricio; Álvarez-Lobos, Manuel; Golenbock, Douglas; González, María-Julieta; López-Kostner, Francisco; Quera, Rodrigo; Núñez, Gabriel; Vidal, Roberto; Hermoso, Marcela A

2014-05-01

Crohn's disease (CD) is a multifactorial pathology associated with the presence of adherent-invasive Escherichia coli (AIEC) and NLRP3 polymorphic variants. The presence of intracellular E. coli in other intestinal pathologies (OIP) and the role of NLRP3-inflammasome in the immune response activated by these bacteria have not been investigated. In this study, we sought to characterize intracellular strains isolated from patients with CD, ulcerative colitis (UC) and OIP, and analyze NLRP3-inflammasome role in the immune response and bactericidal activity induced in macrophages exposed to invasive bacteria. For this, intracellular E. coli isolation from ileal biopsies, using gentamicin-protection assay, revealed a prevalence and CFU/biopsy of E. coli higher in biopsies from CD, UC and OIP patients than in controls. To characterize bacterial isolates, pulsed-field gel electrophoresis (PFGE) patterns, virulence genes, serogroup and phylogenetic group were analyzed. We found out that bacteria isolated from a given patient were closely related and shared virulence factors; however, strains from different patients were genetically heterogeneous. AIEC characteristics in isolated strains, such as invasive and replicative properties, were assessed in epithelial cells and macrophages, respectively. Some strains from CD and UC demonstrated AIEC properties, but not strains from OIP. Furthermore, the role of NLRP3 in pro-inflammatory cytokines production and bacterial elimination was determined in macrophages. E. coli strains induced IL-1β through NLRP3-dependent mechanism; however, their elimination by macrophages was independent of NLRP3. Invasiveness of intracellular E. coli strains into the intestinal mucosa and IL-1β production may contribute to CD and UC pathogenesis. Copyright © 2014 Elsevier GmbH. All rights reserved.

‘Bobo-Newton syndrome’: An unwanted gift from man’s best friend

PubMed Central

Popiel, Kristin Y; Vinh, Donald C

2013-01-01

Capnocytophaga canimorsus is a facultative Gram-negative bacillus that is typically a constituent of the oral flora of dogs and cats. It was first isolated by Bobo and Newton in 1976 from a man presenting with meningitis following a dog bite. Transmission to humans follows various animal-related injuries, which may be gross or subtle. C canimorsus can cause a spectrum of syndromes ranging from skin and soft tissue infection to invasive disease such as meningitis or endocarditis. The present article reports a case of C canimorsus meningitis in a patient with the classic risk factor of alcoholic liver cirrhosis. Clinical suspicion was confirmed by culture and genetic identification of the blood isolate. The present article reviews the Capnocytophaga genus, the clinical syndromes most commonly associated with this zoonotic organism, its laboratory identification and treatment. PMID:24489563

Association of clinical and demographic factors in invasive candidiasis caused by fluconazole-resistant Candida species: a study in 15 hospitals, Medellín, Colombia 2010-2011.

PubMed

Maldonado, Natalia Andrea; Cano, Luz Elena; De Bedout, Catalina; Arbeláez, Carlos Alberto; Roncancio, Gustavo; Tabares, Angela María; Robledo, Carlos Gonzalo; Robledo, Jaime

2014-06-01

Candida is the most important agent of fungal infections. Several risk factors have been described associated with invasive infection by fluconazole-resistant Candida spp. A prospective cross-sectional study with case-control analysis was conducted. Case group patients with fluconazole-resistant Candida isolate were included; control group were patients with fluconazole-susceptible Candida spp. A multivariate logistic regression model was performed. Three hundred isolates of Candida spp. were analyzed. Most frequent species were Candida albicans/Candida dubliniensis (48.3%) and Candida tropicalis (22.3%). Posaconazole susceptibility was 93.7%; voriconazole, 84%; and fluconazole, 78.7%. Susceptibility to anidulafungin and caspofungin was 92.7% and 92.3%, respectively. Neutropenia (adjusted odds ratio [aOR] 6.5, 95% confidence interval [CI] 1.0-43.1), antifungal exposure (aOR 5.1, 95% CI 2.3-11.2), and antituberculosis therapy (aOR 7.7, 95% CI 1.4-43.2) were associated to fluconazole resistance. Susceptibility results are useful to guide the selection of empiric antifungal treatment and the design of local therapeutic guidelines. Previous antifungal exposure suggests possible resistance to fluconazole, pointing towards the selection of a different class of antifungal agents. Copyright © 2014 Elsevier Inc. All rights reserved.

Invasive meningococcal disease in children in Jerusalem

PubMed Central

STEIN-ZAMIR, C.; ABRAMSON, N.; ZENTNER, G.; SHOOB, H.; VALINSKY, L.; BLOCK, C.

2008-01-01

SUMMARY Neisseria meningitidis is an important cause of childhood meningitis and septicaemia. Between 1999 and 2005, 133 invasive meningococcal disease (IMD) cases occurred in Jerusalem, 112 (84·2%) of them in children aged 0–14 years. The annual incidence rate in Jerusalem was higher than the national average (2·45±0·6 vs. 1·13±0·16/100 000 population, P=0·002). Most of the children (82·1%) were from low socio-economic Arab and Jewish ultra-orthodox communities; mortality was higher among Arab than Jewish children (1·3 vs. 0·22/100 000 person-years, P=0·004). A cluster of 10 children with severe meningococcal sepsis (three fatalities) emerged in the winter of 2003–2004. Compared to the other 102 cases in 1999–2005 both meningococcaemia (100% vs. 51%, P=0·003) and mortality (30% vs. 6·9%, P=0·014) rates were higher. Serogroup B comprised 77·6% of the bacterial isolates. Pulsed-field gel electrophoresis showed considerable variability among cluster isolates, but significant resemblance in Arab cases throughout 1999–2005. The increased susceptibility of specific sub-populations to IMD necessitates further evaluation. PMID:17662169

Distribution of emm types among group A Streptococcus isolates from children in Korea.

PubMed

Choi, Jae Hong; Yang, Nu-Ri; Lee, Woon-Jeong; Lee, Hyunju; Choi, Eun Hwa; Lee, Hoan Jong

2015-05-01

We analyzed 155 clinical group A Streptococcus (GAS) isolates from children at the Seoul National University Children's Hospital between 1991 and 2012 and the Seoul National University Bundang Hospital between 2006 and 2012. The erythromycin resistance rate was 10.3% (16/155), and all isolates during the recent 3 years were susceptible to erythromycin. Among isolates, emm1 (19.4%), emm12 (18.7%), and emm4 (18.1%) were the most prevalent emm types. According to clinical disease, emm1 was most common in invasive GAS infections (47.4%), and emm4, in scarlet fever (48.8%). From 2010 to 2012, an increase in invasive GAS infections and scarlet fever that correlated with an increase in emm1 and emm4 types was observed. The speC detection rate was higher in patients with scarlet fever than in those with other GAS infections (P=0.017). Recently, invasive GAS infections and scarlet fever were associated with an increase in emm1 and emm4, respectively. Copyright © 2015 Elsevier Inc. All rights reserved.

Community-acquired Legionnaires' disease caused by Legionella pneumophila serogroup 10 linked to the private home.

PubMed

Lück, Paul Christian; Schneider, Thomas; Wagner, Jutta; Walther, Ilona; Reif, Ursula; Weber, Stefan; Weist, Klaus

2008-02-01

We describe the case of a 66-year-old man with a culture-proven Legionella pneumonia after kidney transplantation. The patient developed the infection 15 days after discharge from a university hospital. Legionella pneumonia caused by Legionella pneumophila serogroup 5/10 was established by positive direct fluorescence assay, positive urinary-antigen detection and isolation of the causative agent. The infection was successfully treated by giving appropriate antibiotics, but the further course was complicated by invasive aspergillosis, cytomegalovirus pneumonia, failure of the transplanted kidney and development of septic anaemia. Four months after the diagnosis of Legionella pneumonia the patient died of multi-organ failure. The microbiological and epidemiological investigation revealed that strains from the water supply of the patient's private home were indistinguishable from the patient's isolate by amplified fragment length polymorphism analysis and sequence-based typing (SBT). Unrelated strains of serogroups 4, 5, 8 and 10 from the Dresden strain collection were of different SBT types. Thus, SBT is a very useful tool for epidemiological investigation of infections by L. pneumophila serogroups other than serogroup 1.

A glimpse of streptococcal toxic shock syndrome from comparative genomics of S. suis 2 Chinese isolates.

PubMed

Chen, Chen; Tang, Jiaqi; Dong, Wei; Wang, Changjun; Feng, Youjun; Wang, Jing; Zheng, Feng; Pan, Xiuzhen; Liu, Di; Li, Ming; Song, Yajun; Zhu, Xinxing; Sun, Haibo; Feng, Tao; Guo, Zhaobiao; Ju, Aiping; Ge, Junchao; Dong, Yaqing; Sun, Wen; Jiang, Yongqiang; Wang, Jun; Yan, Jinghua; Yang, Huanming; Wang, Xiaoning; Gao, George F; Yang, Ruifu; Wang, Jian; Yu, Jun

2007-03-21

Streptococcus suis serotype 2 (SS2) is an important zoonotic pathogen, causing more than 200 cases of severe human infection worldwide, with the hallmarks of meningitis, septicemia, arthritis, etc. Very recently, SS2 has been recognized as an etiological agent for streptococcal toxic shock syndrome (STSS), which was originally associated with Streptococcus pyogenes (GAS) in Streptococci. However, the molecular mechanisms underlying STSS are poorly understood. To elucidate the genetic determinants of STSS caused by SS2, whole genome sequencing of 3 different Chinese SS2 strains was undertaken. Comparative genomics accompanied by several lines of experiments, including experimental animal infection, PCR assay, and expression analysis, were utilized to further dissect a candidate pathogenicity island (PAI). Here we show, for the first time, a novel molecular insight into Chinese isolates of highly invasive SS2, which caused two large-scale human STSS outbreaks in China. A candidate PAI of approximately 89 kb in length, which is designated 89K and specific for Chinese SS2 virulent isolates, was investigated at the genomic level. It shares the universal properties of PAIs such as distinct GC content, consistent with its pivotal role in STSS and high virulence. To our knowledge, this is the first PAI candidate from S. suis worldwide. Our finding thus sheds light on STSS triggered by SS2 at the genomic level, facilitates further understanding of its pathogenesis and points to directions of development on some effective strategies to combat highly pathogenic SS2 infections.

Clinical features of human salmonellosis caused by bovine-associated subtypes in New York.

PubMed

Cummings, Kevin J; Warnick, Lorin D; Gröhn, Yrjö T; Hoelzer, Karin; Root, Timothy P; Siler, Julie D; McGuire, Suzanne M; Wright, Emily M; Zansky, Shelley M; Wiedmann, Martin

2012-09-01

The objective of this study was to identify patient symptoms and case outcomes that were more likely to occur as a result of Salmonella infections caused by bovine-associated subtypes (isolates that matched contemporary bovine isolates from New York by serovar and pulsed-field gel electrophoresis pattern), as compared to salmonellosis caused by non-bovine-associated subtypes. Data were collected in 34 counties of New York that comprise the Foodborne Diseases Active Surveillance Network (FoodNet) catchment area of the Centers for Disease Control and Prevention Emerging Infections Program. Patients with specimen collection dates between March 1, 2008 and March 1, 2010 were included. Symptoms and outcomes of 40 cases infected with bovine-associated Salmonella subtypes were compared to those of 379 control-cases infected with Salmonella isolates that were not bovine-associated. Cases were significantly more likely to have invasive salmonellosis (odds ratio, 3.8; p-value=0.02), after adjusting for age group, gender, and race. In addition, there was a marginal association between case status and the presence of blood in the stool (p-value=0.1) while ill. These findings might have implications for patient management, as a history of consuming undercooked foods of bovine origin or having direct contact with cattle in the few days prior to illness could be useful for suggesting a more proactive diagnostic approach as well as close monitoring for the need to implement more aggressive therapy.

Clinical Features of Human Salmonellosis Caused by Bovine-Associated Subtypes in New York

PubMed Central

Warnick, Lorin D.; Gröhn, Yrjö T.; Hoelzer, Karin; Root, Timothy P.; Siler, Julie D.; McGuire, Suzanne M.; Wright, Emily M.; Zansky, Shelley M.; Wiedmann, Martin

2012-01-01

Abstract The objective of this study was to identify patient symptoms and case outcomes that were more likely to occur as a result of Salmonella infections caused by bovine-associated subtypes (isolates that matched contemporary bovine isolates from New York by serovar and pulsed-field gel electrophoresis pattern), as compared to salmonellosis caused by non-bovine-associated subtypes. Data were collected in 34 counties of New York that comprise the Foodborne Diseases Active Surveillance Network (FoodNet) catchment area of the Centers for Disease Control and Prevention Emerging Infections Program. Patients with specimen collection dates between March 1, 2008 and March 1, 2010 were included. Symptoms and outcomes of 40 cases infected with bovine-associated Salmonella subtypes were compared to those of 379 control-cases infected with Salmonella isolates that were not bovine-associated. Cases were significantly more likely to have invasive salmonellosis (odds ratio, 3.8; p-value=0.02), after adjusting for age group, gender, and race. In addition, there was a marginal association between case status and the presence of blood in the stool (p-value=0.1) while ill. These findings might have implications for patient management, as a history of consuming undercooked foods of bovine origin or having direct contact with cattle in the few days prior to illness could be useful for suggesting a more proactive diagnostic approach as well as close monitoring for the need to implement more aggressive therapy. PMID:22870888

Aspergillus felis sp. nov., an Emerging Agent of Invasive Aspergillosis in Humans, Cats, and Dogs

PubMed Central

Barrs, Vanessa R.; van Doorn, Tineke M.; Houbraken, Jos; Kidd, Sarah E.; Martin, Patricia; Pinheiro, Maria Dolores; Richardson, Malcolm; Varga, Janos; Samson, Robert A.

2013-01-01

We describe a novel heterothallic species in Aspergillus section Fumigati, namely A. felis (neosartorya-morph) isolated from three host species with invasive aspergillosis including a human patient with chronic invasive pulmonary aspergillosis, domestic cats with invasive fungal rhinosinusitis and a dog with disseminated invasive aspergillosis. Disease in all host species was often refractory to aggressive antifungal therapeutic regimens. Four other human isolates previously reported as A. viridinutans were identified as A. felis on comparative sequence analysis of the partial β-tubulin and/or calmodulin genes. A. felis is a heterothallic mold with a fully functioning reproductive cycle, as confirmed by mating-type analysis, induction of teleomorphs within 7 to 10 days in vitro and ascospore germination. Phenotypic analyses show that A. felis can be distinguished from the related species A. viridinutans by its ability to grow at 45°C and from A. fumigatus by its inability to grow at 50°C. Itraconazole and voriconazole cross-resistance was common in vitro. PMID:23798996

Investigation of molecular metabolites in expired air of healthy man in condition of long-term isolation in hermetical confined environment

NASA Astrophysics Data System (ADS)

Tsarkov, Dmitriy; Mardanov, Robert; Markin, Andrey; Moukhamedieva, Lana

Investigation of intermediary metabolites, produced in cells, in expired air of healthy man is directed on determination of molecular markers which are reflecting normal physiological pro-cesses in an organism, as well as on determination and validation of biomarkers for objective screening and non-invasive prenosological diagnostics of disorders in metabolic processes caused by negative effect of live environment. Investigation of influence of long-term isolation in her-metical confined environment on composition of healthy human expired air was made during experiment with 105 days isolation in condition of controlled environment and standard food ra-tion. Expired air samples were analyzed on gas chromatograph associated with the quadrupole mass spectrometer. The investigation results show that at rest hydroxy ketones, mostly 1-hydroxy-prorapanone-2 (acetol), aldehydes (decenal, benzaldehyde), acetophenone, phenol and fatty acids were determined. After physical performance (oxidative stress) the content of ke-tones (heptanone-2, heptanone-3), phenol, determined aldehydes (decenal, octadecenal) and acetol in expired air of volunteers decreased. It can be concerned with prevailing of alternative -methylglyoxalic metabolic pathway and caused by oxidative stress. Analysis of expired air samples taken on 30, 60 and 90 day of isolation showed that in conditions of long-term iso-lation concentration of heptanone-2, heptanone-3, 2,3-butadione, acetol, furanones, aldehydes (decenal, benzaldehyde) and acetophenone is increasing while concentration of phenol and fatty acids is decreasing as compared to samples taken before isolation. It was shown that dynamics of concentration of saturated hydrocarbons in expired air can be informative marker for estima-tion of organism response to oxidative stress, while the level of acetol can be used as indicator of man's training status, validity of exercise load and as a marker of hypoxic state.

[Invasive aspergillosis with extrapulmonary involvement: pathogenesis, clinical characteristics and prognosis].

PubMed

López-Cortés, Luis Eduardo; Garcia-Vidal, Carolina; Ayats, Josefina; Gudiol, Carlota; Bodro, Marta; Sánchez-Ortega, Isabel; Peña, Carmen; Carratalá, Jordi

2012-01-01

The incidence of invasive aspergillosis has increased worldwide. Information regarding the clinical characteristics of patients with extrapulmonary involvement is scarce. We aimed to describe the pathogenesis, characteristics and outcomes of patients with invasive aspergillosis and extrapulmonary disease. A retrospective study conducted in a university hospital in Barcelona, Spain (1995-2011). A total of 12 cases of invasive aspergillosis and extrapulmonary involvement were found. The most common clinical manifestations were invasive sinusitis, early postoperative prosthetic valve endocarditis, fungaemia, postoperative meningitis, multiple brain abscesses and lumbar spondylitis with epidural abscess. Sinusitis occurred frequently in patients without immunosuppression and had invasive brain involvement in one case. Endocarditis was associated with multiple septic metastases. Concomitant lung involvement was documented in 5 cases. The strains isolated were Aspergillus fumigatus (5), Aspergillus flavus (3), and Aspergillus niger (2). The species of Aspergillus was not established for 3 isolates. All patients were treated with antifungals and surgery was performed in 8 cases. Outcome was related with the source of infection; all patients with invasive sinusitis survived, while the remaining patients had a high mortality rate (88%). Invasive aspergillosis with extrapulmonary involvement is rare. The most common presentation is invasive sinusitis, which has a lower mortality. Other clinical forms with extrapulmonary involvement were associated with severe immunosuppression or previous surgery, and had a poor outcome. Copyright © 2011 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Description of the Pathogenic Features of Streptococcus pyogenes Isolates from Invasive and Non-Invasive Diseases in Aichi, Japan.

PubMed

Matsumoto, Masakado; Yamada, Kazuhiro; Suzuki, Masahiro; Adachi, Hirokazu; Kobayashi, Shinichi; Yamashita, Teruo; Minagawa, Hiroko; Tatsuno, Ichiro; Hasegawa, Tadao

2016-07-22

We identified hypervirulent Streptococcus pyogenes in 27 and 420 isolates from patients with invasive and non-invasive diseases, respectively, in Aichi Prefecture, Japan, between 2003 and 2012, in an attempt to understand why the prevalence of streptococcal toxic shock syndrome (STSS) suddenly increased in this location during 2011. Hypervirulent strains belong to the emm1 genotype, with a mutation in the covR/S genes that regulate many other genes, encoding virulence determinants and resulting in the absence of the proteinase streptococcal exotoxin B and the production of virulence factors such as the superantigen streptococcal exotoxin A, the nuclease streptococcal DNase, the cytotoxin NAD-glycohydrolase, and the hemolysin streptolysin O. We found 1 strain from invasive disease and 1 from non-invasive disease with traits similar to those of hypervirulent strains, except that the sda1 gene was absent. We also found 1 non-emm1 strain with phenotypic and genetic traits identical to those of the emm1 hypervirulent strains except that it did not belong to emm1 genotype, from non-invasive diseases cases in 2011. These findings suggested that hypervirulent and hypervirulent-like strains from invasive and non-invasive disease cases could have at least partially contributed to the sudden increase in the number of patients with STSS in Aichi during 2011.

Molecular Types of Methicillin-Resistant Staphylococcus aureus and Methicillin-Sensitive S. aureus Strains Causing Skin and Soft Tissue Infections and Nasal Colonization, Identified in Community Health Centers in New York City

PubMed Central

Pardos de la Gandara, Maria; Raygoza Garay, Juan Antonio; Mwangi, Michael; Tobin, Jonathan N.; Tsang, Amanda; Khalida, Chamanara; D'Orazio, Brianna; Kost, Rhonda G.; Leinberger-Jabari, Andrea; Coffran, Cameron; Evering, Teresa H.; Coller, Barry S.; Balachandra, Shirish; Urban, Tracie; Parola, Claude; Salvato, Scott; Jenks, Nancy; Wu, Daren; Burgess, Rhonda; Chung, Marilyn; de Lencastre, Herminia

2015-01-01

In November 2011, The Rockefeller University Center for Clinical and Translational Science (CCTS), the Laboratory of Microbiology and Infectious Diseases, and Clinical Directors Network (CDN) launched a research and learning collaborative project with six community health centers in the New York City metropolitan area to determine the nature (clonal type) of community-acquired Staphylococcus aureus strains causing skin and soft tissue infections (SSTIs). Between November 2011 and March 2013, wound and nasal samples from 129 patients with active SSTIs suspicious for S. aureus were collected and characterized by molecular typing techniques. In 63 of 129 patients, the skin wounds were infected by S. aureus: methicillin-resistant S. aureus (MRSA) was recovered from 39 wounds and methicillin-sensitive S. aureus (MSSA) was recovered from 24. Most—46 of the 63–wound isolates belonged to the CC8/Panton-Valentine leukocidin-positive (PVL+) group of S. aureus clone USA300: 34 of these strains were MRSA and 12 were MSSA. Of the 63 patients with S. aureus infections, 30 were also colonized by S. aureus in the nares: 16 of the colonizing isolates were MRSA, and 14 were MSSA, and the majority of the colonizing isolates belonged to the USA300 clonal group. In most cases (70%), the colonizing isolate belonged to the same clonal type as the strain involved with the infection. In three of the patients, the identity of invasive and colonizing MRSA isolates was further documented by whole-genome sequencing. PMID:26063853

Destruction of the hepatocyte junction by intercellular invasion of Leptospira causes jaundice in a hamster model of Weil's disease

PubMed Central

Miyahara, Satoshi; Saito, Mitsumasa; Kanemaru, Takaaki; Villanueva, Sharon Y A M; Gloriani, Nina G; Yoshida, Shin-ichi

2014-01-01

Weil's disease, the most severe form of leptospirosis, is characterized by jaundice, haemorrhage and renal failure. The mechanisms of jaundice caused by pathogenic Leptospira remain unclear. We therefore aimed to elucidate the mechanisms by integrating histopathological changes with serum biochemical abnormalities during the development of jaundice in a hamster model of Weil's disease. In this work, we obtained three-dimensional images of infected hamster livers using scanning electron microscope together with freeze-cracking and cross-cutting methods for sample preparation. The images displayed the corkscrew-shaped bacteria, which infiltrated the Disse's space, migrated between hepatocytes, detached the intercellular junctions and disrupted the bile canaliculi. Destruction of bile canaliculi coincided with the elevation of conjugated bilirubin, aspartate transaminase and alkaline phosphatase levels in serum, whereas serum alanine transaminase and γ-glutamyl transpeptidase levels increased slightly, but not significantly. We also found in ex vivo experiments that pathogenic, but not non-pathogenic leptospires, tend to adhere to the perijunctional region of hepatocyte couplets isolated from hamsters and initiate invasion of the intercellular junction within 1 h after co-incubation. Our results suggest that pathogenic leptospires invade the intercellular junctions of host hepatocytes, and this invasion contributes in the disruption of the junction. Subsequently, bile leaks from bile canaliculi and jaundice occurs immediately. Our findings revealed not only a novel pathogenicity of leptospires, but also a novel mechanism of jaundice induced by bacterial infection. PMID:24945433

Cryptococcus laurentii fungaemia in a cervical cancer patient.

PubMed

Neves, Rejane Pereira; Lima Neto, Reginaldo Gonçalves de; Leite, Melyna Chaves; Silva, Vanessa Karina Alves da; Santos, Franz de Assis Graciano dos; Macêdo, Danielle Patrícia Cerqueira

2015-01-01

Infections caused by emerging Cryptococcus non-neoformans species are being reported with increasingly frequency. Here, we present a case of fungaemia by Cryptococcus laurentii in a woman receiving aggressive immunosuppressive therapy for cervical neoplasia. Three venous blood samples were aseptically collected on consecutive days and C. laurentii was isolated and identified through phenotypic and molecular methods. After central venous catheter removal and appropriate antifungal therapy, the patient showed significant improvement and blood culture became negative. Thus, patients following immunosuppressive therapies and using invasive medical devices are at risk of C. laurentii blood infections. Copyright © 2015 Elsevier Editora Ltda. All rights reserved.

Isolation of the Rare Opportunistic Yeast Saprochaete capitata from Clinical Samples-Experience from a Tertiary Care Hospital in Southern India and a Brief Review of the Literature

PubMed Central

Kancharla, Anuradha; Sudhaharan, Sukanya; Gundeti, Sadashivudu; Mandarapu, Surendra; Nagalla, Vamsi Krishna; Raju, Sree Bhushan; Karanam, Sandhya Devi

2017-01-01

Introduction Saprochaete capitata (Teleomorph: Magnusiomyces capitatus) is a ubiquitous yeast found in environmental sources such as soil, water, air, plants and dairy products. It is also a part of the normal microbial flora in humans. The yeast is being increasingly reported as an opportunistic pathogen, especially in patients in the haemato-oncology setting, the infection being often mistakenly diagnosed as invasive candidiasis. Aim To review the epidemiological, clinical and microbiological features of six patients admitted in our hospital over a period of 10 years (from January 2007 to December 2016), from whom Saprochaete capitata was isolated. Materials and Methods A retrospective study was conducted and the epidemiological, clinical, imaging and microbiological data of the six patients were collected and analysed. Results The age of the six patients ranged from 19 years to 65 years with a median age of 53 years. There were two males and four females. In three out of the six patients, the isolation of S. capitata was considered clinically significant as the yeast was isolated repeatedly from blood and/or respiratory specimens and the clinical features could not be explained by any other alternative diagnosis. Haematological malignancy was the underlying disease in three out of the six patients while one patient was on triple immunosuppression following renal transplantation four years back. Three out of the six patients had severe neutropenia with Absolute Neutrophil Count (ANC) ≤ 500 at the time of isolation of S. capitata. Two patients with clinical features of fungal sepsis received antifungal therapy with Amphotericin B but succumbed within a short period of starting the therapy. The post renal transplant patient who presented with pneumonia recovered after treatment with a combination of Amphotericin B and Voriconazole. Conclusion Awareness regarding the epidemiological, clinical and microbiological aspects of invasive infections caused by S. capitata is essential for early recognition and appropriate management. PMID:29207709

Host-induced aneuploidy and phenotypic diversification in the Sudden Oak Death pathogen Phytophthora ramorum.

PubMed

Kasuga, Takao; Bui, Mai; Bernhardt, Elizabeth; Swiecki, Tedmund; Aram, Kamyar; Cano, Liliana M; Webber, Joan; Brasier, Clive; Press, Caroline; Grünwald, Niklaus J; Rizzo, David M; Garbelotto, Matteo

2016-05-20

Aneuploidy can result in significant phenotypic changes, which can sometimes be selectively advantageous. For example, aneuploidy confers resistance to antifungal drugs in human pathogenic fungi. Aneuploidy has also been observed in invasive fungal and oomycete plant pathogens in the field. Environments conducive to the generation of aneuploids, the underlying genetic mechanisms, and the contribution of aneuploidy to invasiveness are underexplored. We studied phenotypic diversification and associated genome changes in Phytophthora ramorum, a highly destructive oomycete pathogen with a wide host-range that causes Sudden Oak Death in western North America and Sudden Larch Death in the UK. Introduced populations of the pathogen are exclusively clonal. In California, oak (Quercus spp.) isolates obtained from trunk cankers frequently exhibit host-dependent, atypical phenotypes called non-wild type (nwt), apparently without any host-associated population differentiation. Based on a large survey of genotypes from different hosts, we previously hypothesized that the environment in oak cankers may be responsible for the observed phenotypic diversification in P. ramorum. We show that both normal wild type (wt) and nwt phenotypes were obtained when wt P. ramorum isolates from the foliar host California bay (Umbellularia californica) were re-isolated from cankers of artificially-inoculated canyon live oak (Q. chrysolepis). We also found comparable nwt phenotypes in P. ramorum isolates from a bark canker of Lawson cypress (Chamaecyparis lawsoniana) in the UK; previously nwt was not known to occur in this pathogen population. High-throughput sequencing-based analyses identified major genomic alterations including partial aneuploidy and copy-neutral loss of heterozygosity predominantly in nwt isolates. Chromosomal breakpoints were located at or near transposons. This work demonstrates that major genome alterations of a pathogen can be induced by its host species. This is an undocumented type of plant-microbe interaction, and its contribution to pathogen evolution is yet to be investigated, but one of the potential collateral effects of nwt phenotypes may be host survival.

Enhanced surveillance of invasive listeriosis in the Lombardy region, Italy, in the years 2006-2010 reveals major clones and an increase in serotype 1/2a

PubMed Central

2013-01-01

Background Invasive listeriosis is a rare, life-threatening foodborne disease. Lombardy, an Italian region accounting for 16% of the total population, reported 55% of all listeriosis cases in the years 2006-2010. The aim of our study was to provide a snapshot of listeriosis epidemiology in this region after the implementation of a voluntary laboratory-based surveillance system. Methods We characterized by serotyping, pulsed-field gel electrophoresis, multilocus sequence typing and detection of epidemic clone markers, 134 isolates from 132 listeriosis cases, including 15 pregnancy-related cases, occurring in the years 2006-2010 in Lombardy. Demographic and clinical characteristics of cases have also been described. Results The mean age of non pregnancy-associated cases was 64.7 years, with 55.9% of cases being older than 65 years. Cases having no underlying medical conditions accounted for 11.6%. The all-cause fatality rate of 83 cases with a known survival outcome was 25.3%. Serotypes 1/2a and 4b comprised 52.2% and 38.8% of isolates, respectively. Seventy-three AscI pulsotypes and 25 sequence types assigned to 23 clonal complexes were recognized. Moreover, 53 (39.5%) isolates tested positive for the epidemic clone markers. Twelve molecular subtype clusters including at least three isolates were detected, with cluster 11 (1/2a/ST38) including 31 isolates identified during the entire study period. No outbreaks were notified to public health authorities during this period. Conclusions The findings of our study proved that epidemiology of listeriosis in Lombardy is characterized by a high prevalence of major clones and the increasing role of serotype 1/2a. Molecular subtyping is an essential tool in the epidemiology and surveillance of listeriosis. Rapid molecular cluster detection could alert about putative outbreaks, thus increasing the chance of detecting and inactivating routes of transmission. PMID:23530941

Enhanced surveillance of invasive listeriosis in the Lombardy region, Italy, in the years 2006-2010 reveals major clones and an increase in serotype 1/2a.

PubMed

Mammina, Caterina; Parisi, Antonio; Guaita, Anna; Aleo, Aurora; Bonura, Celestino; Nastasi, Antonino; Pontello, Mirella

2013-03-26

Invasive listeriosis is a rare, life-threatening foodborne disease. Lombardy, an Italian region accounting for 16% of the total population, reported 55% of all listeriosis cases in the years 2006-2010. The aim of our study was to provide a snapshot of listeriosis epidemiology in this region after the implementation of a voluntary laboratory-based surveillance system. We characterized by serotyping, pulsed-field gel electrophoresis, multilocus sequence typing and detection of epidemic clone markers, 134 isolates from 132 listeriosis cases, including 15 pregnancy-related cases, occurring in the years 2006-2010 in Lombardy. Demographic and clinical characteristics of cases have also been described. The mean age of non pregnancy-associated cases was 64.7 years, with 55.9% of cases being older than 65 years. Cases having no underlying medical conditions accounted for 11.6%. The all-cause fatality rate of 83 cases with a known survival outcome was 25.3%.Serotypes 1/2a and 4b comprised 52.2% and 38.8% of isolates, respectively. Seventy-three AscI pulsotypes and 25 sequence types assigned to 23 clonal complexes were recognized. Moreover, 53 (39.5%) isolates tested positive for the epidemic clone markers. Twelve molecular subtype clusters including at least three isolates were detected, with cluster 11 (1/2a/ST38) including 31 isolates identified during the entire study period. No outbreaks were notified to public health authorities during this period. The findings of our study proved that epidemiology of listeriosis in Lombardy is characterized by a high prevalence of major clones and the increasing role of serotype 1/2a. Molecular subtyping is an essential tool in the epidemiology and surveillance of listeriosis. Rapid molecular cluster detection could alert about putative outbreaks, thus increasing the chance of detecting and inactivating routes of transmission.

Use of a repetitive DNA probe to type clinical and environmental isolates of Aspergillus flavus from a cluster of cutaneous infections in a neonatal intensive care unit.

PubMed

James, M J; Lasker, B A; McNeil, M M; Shelton, M; Warnock, D W; Reiss, E

2000-10-01

Aspergillus flavus is second to A. fumigatus as a cause of invasive aspergillosis, but no standard method exists for molecular typing of strains from human sources. A repetitive DNA sequence cloned from A. flavus and subcloned into a pUC19 vector, pAF28, was used to type 18 isolates from diverse clinical, environmental, and geographic sources. The restriction fragment length polymorphisms generated with EcoRI- or PstI-digested genomic DNA and probed with digoxigenin-labeled pAF28 revealed complete concordance between patterns. Eighteen distinct fingerprints were observed. The probe was used to investigate two cases of cutaneous A. flavus infection in low-birth-weight infants in a neonatal intensive care unit (NICU). Both infants were transported by the same ambulance and crew to the NICU on the same day. A. flavus strains of the same genotype were isolated from both infants, from a roll of tape used to fasten their umbilical catheters, from a canvas bag used to store the tape in the ambulance, and from the tape tray in the ambulance isolette. These cases highlight the need to consider exposures in critically ill neonates that might occur during their transport to the NICU and for stringent infection control practices. The hybridization profiles of strains from a second cluster of invasive A. flavus infections in two pediatric hematology-oncology patients revealed a genotype common to strains from a definite case patient and a health care worker. A probable case patient was infected with a strain with a genotype different from that of the strain from the definite case patient but highly related to that of an environmental isolate. The high degree of discrimination and reproducibility obtained with the pAF28 probe underscores its utility for typing clinical and environmental isolates of A. flavus.

Use of a Repetitive DNA Probe To Type Clinical and Environmental Isolates of Aspergillus flavus from a Cluster of Cutaneous Infections in a Neonatal Intensive Care Unit

PubMed Central

James, Michael J.; Lasker, Brent A.; McNeil, Michael M.; Shelton, Mark; Warnock, David W.; Reiss, Errol

2000-01-01

Aspergillus flavus is second to A. fumigatus as a cause of invasive aspergillosis, but no standard method exists for molecular typing of strains from human sources. A repetitive DNA sequence cloned from A. flavus and subcloned into a pUC19 vector, pAF28, was used to type 18 isolates from diverse clinical, environmental, and geographic sources. The restriction fragment length polymorphisms generated with EcoRI- or PstI-digested genomic DNA and probed with digoxigenin-labeled pAF28 revealed complete concordance between patterns. Eighteen distinct fingerprints were observed. The probe was used to investigate two cases of cutaneous A. flavus infection in low-birth-weight infants in a neonatal intensive care unit (NICU). Both infants were transported by the same ambulance and crew to the NICU on the same day. A. flavus strains of the same genotype were isolated from both infants, from a roll of tape used to fasten their umbilical catheters, from a canvas bag used to store the tape in the ambulance, and from the tape tray in the ambulance isolette. These cases highlight the need to consider exposures in critically ill neonates that might occur during their transport to the NICU and for stringent infection control practices. The hybridization profiles of strains from a second cluster of invasive A. flavus infections in two pediatric hematology-oncology patients revealed a genotype common to strains from a definite case patient and a health care worker. A probable case patient was infected with a strain with a genotype different from that of the strain from the definite case patient but highly related to that of an environmental isolate. The high degree of discrimination and reproducibility obtained with the pAF28 probe underscores its utility for typing clinical and environmental isolates of A. flavus. PMID:11015372

Changes in In Vitro Susceptibility Patterns of Aspergillus to Triazoles and Correlation With Aspergillosis Outcome in a Tertiary Care Cancer Center, 1999-2015.

PubMed

Heo, Sang Taek; Tatara, Alexander M; Jiménez-Ortigosa, Cristina; Jiang, Ying; Lewis, Russell E; Tarrand, Jeffrey; Tverdek, Frank; Albert, Nathaniel D; Verweij, Paul E; Meis, Jacques F; Mikos, Antonios G; Perlin, David S; Kontoyiannis, Dimitrios P

2017-07-15

Azole-resistant aspergillosis in high-risk patients with hematological malignancy or hematopoietic stem cell transplantation (HSCT) is a cause of concern. We examined changes over time in triazole minimum inhibitory concentrations (MICs) of 290 sequential Aspergillus isolates recovered from respiratory sources during 1999-2002 (before introduction of the Aspergillus-potent triazoles voriconazole and posaconazole) and 2003-2015 at MD Anderson Cancer Center. We also tested for polymorphisms in ergosterol biosynthetic genes (cyp51A, erg3C, erg1) in the 37 Aspergillus fumigatus isolates isolated from both periods that had non-wild-type (WT) MICs. For the 107 patients with hematologic cancer and/or HSCT with invasive pulmonary aspergillosis, we correlated in vitro susceptibility with 42-day mortality. Non-WT MICs were found in 37 (13%) isolates and was only low level (MIC <8 mg/L) in all isolates. Higher-triazole MICs were more frequent in the second period and were Aspergillus-species specific, and only encountered in A. fumigatus. No polymorphisms in cyp51A, erg3C, erg1 genes were identified. There was no correlation between in vitro MICs with 42-day mortality in patients with invasive pulmonary aspergillosis, irrespective of antifungal treatment. Asian race (odds ratio [OR], 20.9; 95% confidence interval [CI], 2.5-173.5; P = .005) and azole exposure in the prior 3 months (OR, 9.6; 95% CI, 1.9-48.5; P = .006) were associated with azole resistance. Non-WT azole MICs in Aspergillus are increasing and this is associated with prior azole exposure in patients with hematologic cancer or HSCT. However, no correlation of MIC with outcome of aspergillosis was found in our patient cohort. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Invasive bacterial disease trends and characterization of group B streptococcal isolates among young infants in southern Mozambique, 2001–2015

PubMed Central

Sigaúque, Betuel; Kobayashi, Miwako; Vubil, Delfino; Nhacolo, Ariel; Chaúque, Alberto; Moaine, Benild; Massora, Sérgio; Mandomando, Inácio; Nhampossa, Tacilta; Bassat, Quique; Pimenta, Fabiana; Menéndez, Clara; Carvalho, Maria da Gloria; Macete, Eusebio; Schrag, Stephanie J.

2018-01-01

Background Maternal group B streptococcal (GBS) vaccines under development hold promise to prevent GBS disease in young infants. Sub-Saharan Africa has the highest estimated disease burden, although data on incidence and circulating strains are limited. We described invasive bacterial disease (IBD) trends among infants <90 days in rural Mozambique during 2001–2015, with a focus on GBS epidemiology and strain characteristics. Methods Community-level birth and mortality data were obtained from Manhiça’s demographic surveillance system. IBD cases were captured through ongoing surveillance at Manhiça district hospital. Stored GBS isolates from cases underwent serotyping by multiplex PCR, antimicrobial susceptibility testing, and whole genome sequencing. Results There were 437 IBD cases, including 57 GBS cases. Significant declines in overall IBD, neonatal mortality, and stillbirth rates were observed (P<0.0001), but not for GBS (P = 0.17). In 2015, GBS was the leading cause of young infant IBD (2.7 per 1,000 live births). Among 35 GBS isolates available for testing, 31 (88.6%) were highly related serotype III isolates within multilocus sequence types (STs) 17 (68.6%) or 109 (20.0%). All seven ST109 isolates (21.9%) had elevated minimum inhibitory concentration (MIC) to penicillin (≥0.12 μg/mL) associated with penicillin-binding protein (PBP) 2x substitution G398A. Epidemiologic and molecular data suggest this is a well-established clone. Conclusion A notable young infant GBS disease burden persisted despite improvements in overall maternal and neonatal health. We report an established strain with pbp2x point mutation, a first-step mutation associated with reduced penicillin susceptibility within a well-known virulent lineage in rural Mozambique. Our findings further underscores the need for non-antibiotic GBS prevention strategies. PMID:29351318

Applications of Computer-Assisted Navigation for the Minimally Invasive Reduction of Isolated Zygomatic Arch Fractures.

PubMed

Li, Zhi; Yang, Rong-Tao; Li, Zu-Bing

2015-09-01

Computer-assisted navigation has been widely used in oral and maxillofacial surgery. The purpose of this study was to describe the applications of computer-assisted navigation for the minimally invasive reduction of isolated zygomatic arch fractures. All patients identified as having isolated zygomatic arch fractures presenting to the authors' department from April 2013 through November 2014 were included in this prospective study. Minimally invasive reductions of isolated zygomatic arch fractures were performed on these patients under the guidance of computer-assisted navigation. The reduction status was evaluated by postoperative computed tomography (CT) 1 week after the operation. Postoperative complications and facial contours were evaluated during follow-up. Functional recovery was evaluated by the difference between the preoperative maximum interincisal mouth opening and that at the final follow-up. Twenty-three patients were included in this case series. The operation proceeded well in all patients. Postoperatively, all patients displayed uneventful healing without postoperative complication. Postoperative CT showed exact reduction in all cases. Satisfactory facial contour and functional recovery were observed in all patients. The preoperative maximal mouth opening ranged from 8 to 25 mm, and the maximal mouth opening at the final follow-up ranged from 36 to 42 mm. Computer-assisted navigation can be used not only for guiding zygomatic arch fracture reduction, but also for assessing reduction. Computer-assisted navigation is an effective and minimally invasive technique that can be applied in the reduction of isolated zygomatic arch fractures. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Anti-microbial resistance stratified by risk factor among Escherichia coli strains isolated from the urinary tract at a rural clinic in Central India.

PubMed

Chatterjee, B; Kulathinal, S; Bhargava, A; Jain, Y; Kataria, R

2009-01-01

The failure of empirical therapy is frequently observed, even in community-acquired urinary tract infections. We, therefore, conducted a prospective, clinic-based study in 2004-2005 to document anti-microbial resistance rates and correlate them with possible risk factors to assist empirical decision-making. Symptomatic patients with pyuria underwent urine culture. Isolates were identified using standard methods and anti-microbial resistance was determined by disk-diffusion. Ultrasonography was used to detect complicating factors. Patients were stratified by the presence of complicating factors and history of invasive procedures for comparison of resistance rates. STATISTICAL METHOD USED: Chi-square or Fisher exact tests, as appropriate. There were 156 E. coli isolates, of which 105 were community-acquired. Twenty-three community-acquired isolates were from patients with complicating factors while 82 were from patients without any. Fifty-one isolates were from patients who had recently undergone invasive procedures on the urinary tract. Thirty-two community-acquired isolates from reproductive-age women without apparent complicating factors had resistance rates of 50% or above against tetracyclines, Co-trimoxazole, aminopenicillins, Nalidixic acid, Ciprofloxacin and 1 st generation cephalosporins. Resistance rates were significantly higher among isolates from patients subjected to invasive procedures, except against Co-trimoxazole, tetracyclines and Amikacin. High rates of anti-microbial resistance in community-acquired uropathogens have made antimicrobial sensitivity testing necessary even in a rural, primary-care setting.

The Genotoxin Colibactin Is a Determinant of Virulence in Escherichia coli K1 Experimental Neonatal Systemic Infection.

PubMed

McCarthy, Alex J; Martin, Patricia; Cloup, Emilie; Stabler, Richard A; Oswald, Eric; Taylor, Peter W

2015-09-01

Escherichia coli strains expressing the K1 capsule are a major cause of sepsis and meningitis in human neonates. The development of these diseases is dependent on the expression of a range of virulence factors, many of which remain uncharacterized. Here, we show that all but 1 of 34 E. coli K1 neonatal isolates carried clbA and clbP, genes contained within the pks pathogenicity island and required for the synthesis of colibactin, a polyketide-peptide genotoxin that causes genomic instability in eukaryotic cells by induction of double-strand breaks in DNA. Inactivation of clbA and clbP in E. coli A192PP, a virulent strain of serotype O18:K1 that colonizes the gastrointestinal tract and translocates to the blood compartment with very high frequency in experimental infection of the neonatal rat, significantly reduced the capacity of A192PP to colonize the gut, engender double-strand breaks in DNA, and cause invasive, lethal disease. Mutation of clbA, which encodes a pleiotropic enzyme also involved in siderophore synthesis, impacted virulence to a greater extent than mutation of clbP, encoding an enzyme specific to colibactin synthesis. Restoration of colibactin gene function by complementation reestablished the fully virulent phenotype. We conclude that colibactin contributes to the capacity of E. coli K1 to colonize the neonatal gastrointestinal tract and to cause invasive disease in the susceptible neonate. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

The Genotoxin Colibactin Is a Determinant of Virulence in Escherichia coli K1 Experimental Neonatal Systemic Infection

PubMed Central

McCarthy, Alex J.; Martin, Patricia; Cloup, Emilie; Stabler, Richard A.

2015-01-01

Escherichia coli strains expressing the K1 capsule are a major cause of sepsis and meningitis in human neonates. The development of these diseases is dependent on the expression of a range of virulence factors, many of which remain uncharacterized. Here, we show that all but 1 of 34 E. coli K1 neonatal isolates carried clbA and clbP, genes contained within the pks pathogenicity island and required for the synthesis of colibactin, a polyketide-peptide genotoxin that causes genomic instability in eukaryotic cells by induction of double-strand breaks in DNA. Inactivation of clbA and clbP in E. coli A192PP, a virulent strain of serotype O18:K1 that colonizes the gastrointestinal tract and translocates to the blood compartment with very high frequency in experimental infection of the neonatal rat, significantly reduced the capacity of A192PP to colonize the gut, engender double-strand breaks in DNA, and cause invasive, lethal disease. Mutation of clbA, which encodes a pleiotropic enzyme also involved in siderophore synthesis, impacted virulence to a greater extent than mutation of clbP, encoding an enzyme specific to colibactin synthesis. Restoration of colibactin gene function by complementation reestablished the fully virulent phenotype. We conclude that colibactin contributes to the capacity of E. coli K1 to colonize the neonatal gastrointestinal tract and to cause invasive disease in the susceptible neonate. PMID:26150540

Negative correlation between phospholipase and esterase activity produced by Fusarium isolates.

PubMed

Ishida, K; Alviano, D S; Silva, B G; Guerra, C R; Costa, A S; Nucci, M; Alviano, C S; Rozental, S

2012-05-01

Fusarium species have emerged as one of the more outstanding groups of clinically important filamentous fungi, causing localized and life-threatening invasive infections with high morbidity and mortality. The ability to produce different types of hydrolytic enzymes is thought to be an important virulence mechanism of fungal pathogens and could be associated with the environment of the microorganism. Here, we have measured the production of two distinct lipolytic enzymes, phospholipase and esterase, by sixteen Fusarium isolates recovered from the hospital environment, immunocompromised patients' blood cultures, foot interdigital space scrapings from immunocompromised patients, and foot interdigital space scrapings from immunocompetent patients (4 isolates each). Fourteen of these 16 isolates were identified as Fusarium solani species complex (FSSC) and two were identified as F. oxysporum species complex (FOSC). Some relevant genus characteristics were visualized by light and electron microscopy such as curved and multicelled macroconidia with 3 or 4 septa, microconidia, phialides, and abundant chlamydospores. All Fusarium isolates were able to produce esterase and phospholipase under the experimental conditions. However, a negative correlation was observed between these two enzymes, indicating that a Fusarium isolate with high phospholipase activity has low esterase activity and vice versa. In addition, Fusarium isolated from clinical material produced more phospholipases, while environmental strains produced more esterases. These observations may be correlated with the different types of substrates that these fungi need to degrade during their nutrition processes.

Negative correlation between phospholipase and esterase activity produced by Fusarium isolates

PubMed Central

Ishida, K.; Alviano, D.S.; Silva, B.G.; Guerra, C.R.; Costa, A.S.; Nucci, M.; Alviano, C.S.; Rozental, S.

2012-01-01

Fusarium species have emerged as one of the more outstanding groups of clinically important filamentous fungi, causing localized and life-threatening invasive infections with high morbidity and mortality. The ability to produce different types of hydrolytic enzymes is thought to be an important virulence mechanism of fungal pathogens and could be associated with the environment of the microorganism. Here, we have measured the production of two distinct lipolytic enzymes, phospholipase and esterase, by sixteen Fusarium isolates recovered from the hospital environment, immunocompromised patients' blood cultures, foot interdigital space scrapings from immunocompromised patients, and foot interdigital space scrapings from immunocompetent patients (4 isolates each). Fourteen of these 16 isolates were identified as Fusarium solani species complex (FSSC) and two were identified as F. oxysporum species complex (FOSC). Some relevant genus characteristics were visualized by light and electron microscopy such as curved and multicelled macroconidia with 3 or 4 septa, microconidia, phialides, and abundant chlamydospores. All Fusarium isolates were able to produce esterase and phospholipase under the experimental conditions. However, a negative correlation was observed between these two enzymes, indicating that a Fusarium isolate with high phospholipase activity has low esterase activity and vice versa. In addition, Fusarium isolated from clinical material produced more phospholipases, while environmental strains produced more esterases. These observations may be correlated with the different types of substrates that these fungi need to degrade during their nutrition processes. PMID:22415116

Consistent loss of genetic diversity in isolated cutthroat trout populations independent of habitat size and quality

Treesearch

Kellie J. Carim; Lisa A. Eby; Craig A. Barfoot; Matthew C. Boyer

2016-01-01

Fragmentation and isolation of wildlife populations has reduced genetic diversity worldwide, leaving many populations vulnerable to inbreeding depression and local extinction. Nonetheless, isolation is protecting many native aquatic species from interactions with invasive species, often making reconnection an unrealistic conservation strategy. Isolation management is...

Virulence of oomycete pathogens from Phragmites australis-invaded and noninvaded soils to seedlings of wetland plant species

PubMed Central

Crocker, Ellen V; Karp, Mary Ann; Nelson, Eric B

2015-01-01

Soil pathogens affect plant community structure and function through negative plant–soil feedbacks that may contribute to the invasiveness of non-native plant species. Our understanding of these pathogen-induced soil feedbacks has relied largely on observations of the collective impact of the soil biota on plant populations, with few observations of accompanying changes in populations of specific soil pathogens and their impacts on invasive and noninvasive species. As a result, the roles of specific soil pathogens in plant invasions remain unknown. In this study, we examine the diversity and virulence of soil oomycete pathogens in freshwater wetland soils invaded by non-native Phragmites australis (European common reed) to better understand the potential for soil pathogen communities to impact a range of native and non-native species and influence invasiveness. We isolated oomycetes from four sites over a 2-year period, collecting nearly 500 isolates belonging to 36 different species. These sites were dominated by species of Pythium, many of which decreased seedling survival of a range of native and invasive plants. Despite any clear host specialization, many of the Pythium species were differentially virulent to the native and non-native plant species tested. Isolates from invaded and noninvaded soils were equally virulent to given individual plant species, and no apparent differences in susceptibility were observed between the collective groups of native and non-native plant species. PMID:26078850

Simulated acid rain alters litter decomposition and enhances the allelopathic potential of the invasive plant Wedelia trilobata (Creeping Daisy)

USDA-ARS?s Scientific Manuscript database

Invasive species and acid rain cause global environmental problems. Limited information exists, however, concerning the effects of acid rain on the invasiveness of these plants. For example, creeping daisy, an invasive exotic allelopathic weed, has caused great damage in southern China where acid ra...

Blood invasiveness of Salmonella enterica as a function of age and serotype.

PubMed Central

Weinberger, M.; Andorn, N.; Agmon, V.; Cohen, D.; Shohat, T.; Pitlik, S. D.

2004-01-01

We explored the dual influence of the patient's age and the infecting serotype on the blood invasiveness patterns of non-Typhi Salmonella enterica (NTS). Blood invasiveness ratio (BIR) was calculated as the ratio between the number of blood and blood + stool isolates. Analysis of 14,951 NTS isolates showed that the BIR increased drastically above the age of 60 years, reaching levels 3.5-7 times higher compared to age group < 2 years. Different patterns of age-related invasiveness were observed for the five most common NTS serotypes (Enteritidis, Typhimurium, Virchow, Hadar, Infantis). Among children < 2 years, the BIR was highest for serotype Virchow and lowest for serotype Hadar, while in persons > or = 60 years it was highest for serotypes Enteritidis and lowest for serotype Infantis. The tendency of NTS serotypes to invade the bloodstream was significantly influenced by the patient's age, however the impact of age differed for various NTS serotypes. PMID:15635958

Streptococcus suis in invasive human infections in Poland: clonality and determinants of virulence and antimicrobial resistance.

PubMed

Bojarska, A; Molska, E; Janas, K; Skoczyńska, A; Stefaniuk, E; Hryniewicz, W; Sadowy, E

2016-06-01

The purpose of this study was to perform an analysis of Streptococcus suis human invasive isolates, collected in Poland by the National Reference Centre for Bacterial Meningitis. Isolates obtained from 21 patients during 2000-2013 were investigated by phenotypic tests, multilocus sequence typing (MLST), analysis of the TR9 locus from the multilocus variable number tandem repeat (VNTR) analysis (MLVA) scheme and pulsed-field gel electrophoresis (PFGE) of SmaI-digested DNA. Determinants of virulence and antimicrobial resistance were detected by polymerase chain reaction (PCR) and analysed by sequencing. All isolates represented sequence type 1 (ST1) and were suggested to be serotype 2. PFGE and analysis of the TR9 locus allowed the discrimination of four and 17 types, respectively. Most of the isolates were haemolysis- and DNase-positive, and around half of them formed biofilm. Genes encoding suilysin, extracellular protein factor, fibronectin-binding protein, muramidase-released protein, surface antigen one, enolase, serum opacity factor and pili were ubiquitous in the studied group, while none of the isolates carried sequences characteristic for the 89K pathogenicity island. All isolates were susceptible to penicillin, cefotaxime, imipenem, moxifloxacin, chloramphenicol, rifampicin, gentamicin, linezolid, vancomycin and daptomycin. Five isolates (24 %) were concomitantly non-susceptible to erythromycin, clindamycin and tetracycline, and harboured the tet(O) and erm(B) genes; for one isolate, lsa(E) and lnu(B) were additionally detected. Streptococcus suis isolated in Poland from human invasive infections belongs to a globally distributed clonal complex of this pathogen, enriched in virulence markers. This is the first report of the lsa(E) and lnu(B) resistance genes in S. suis.

An infant with concurrent serotype 6C invasive pneumococcal disease and infectious mononucleosis.

PubMed

Nishikawa-Nakamura, Naoko; Okada, Takafumi; Nishimura, Keiko; Iwai, Tsuyako; Ubukata, Kimiko; Iwata, Satoshi; Iwai, Asayuki

2017-11-01

Streptococcus pneumoniae is a main causative agent of serious invasive bacterial infections. However, concurrent infection with invasive pneumococcal disease (IPD) and viral infectious mononucleosis (IM) is rare. We report an infant with serotype 6C infection causing IPD occurring simultaneously with IM. A previously healthy 11-month-old girl referred to our hospital because of fever, leukopenia, and elevated C-reactive protein presented to us with disturbance of consciousness, tachycardia, tachypnea and agranulocytosis. Other findings included tonsillitis with purulent exudates and white spots, bilateral cervical adenopathy, and hepatosplenomegaly. We diagnosed her illness as sepsis and administered a broad-spectrum antibiotic, an antiviral agent, and granulocyte transfusions. After treatment was initiated, fever gradually decreased and general condition improved. IPD was diagnosed based upon isolation of S. pneumoniae of serotype 6C from blood cultures obtained on admission. Concurrently the girl had IM, based upon quantitation of Epstein-Barr viral DNA copies in blood and fluctuating serum antibody titers. Although simultaneous IPD and IM is a rare occurrence, this possibility is important to keep in mind. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

The empty OR-process analysis and a new concept for flexible and modular use in minimal invasive surgery.

PubMed

Eckmann, Christian; Olbrich, Guenter; Shekarriz, Hodjat; Bruch, Hans-Peter

2003-01-01

The reproducible advantages of minimal invasive surgery have led to a worldwide spread of these techniques. Nevertheless, the increasing use of technology causes problems in the operating room (OR). The workstation environment and workflow are handicapped by a great number of isolated solutions that demand a large amount of space. The Center of Excellence in Medical Technology (CEMET) was established in 2001 as an institution for a close cooperation between users, science, and manufacturers of medical devices in the State of Schleswig-Holstein, Germany. The future OR, as a major project, began with a detailed process analysis, which disclosed a large number of medical devices with different interfaces and poor standardisation as main problems. Smaller and more flexible devices are necessary, as well as functional modules located outside the OR. Only actuators should be positioned near the operation area. The future OR should include a flexible-room concept and less equipment than is in use currently. A uniform human-user interface is needed to control the OR environment. This article addresses the need for a clear workspace environment, intelligent-user interfaces, and flexible-room concept to improve the potentials in use of minimal invasive surgery.

Epidemiology of Invasive Group A Streptococcal Infections in the United States, 2005-2012.

PubMed

Nelson, George E; Pondo, Tracy; Toews, Karrie-Ann; Farley, Monica M; Lindegren, Mary Lou; Lynfield, Ruth; Aragon, Deborah; Zansky, Shelley M; Watt, James P; Cieslak, Paul R; Angeles, Kathy; Harrison, Lee H; Petit, Susan; Beall, Bernard; Van Beneden, Chris A

2016-08-15

Invasive group A Streptococcus (GAS) infections are associated with significant morbidity and mortality rates. We report the epidemiology and trends of invasive GAS over 8 years of surveillance. From January 2005 through December 2012, we collected data from the Centers for Disease Control and Prevention's Active Bacterial Core surveillance, a population-based network of 10 geographically diverse US sites (2012 population, 32.8 million). We defined invasive GAS as isolation of GAS from a normally sterile site or from a wound in a patient with necrotizing fasciitis (NF) or streptococcal toxic shock syndrome (STSS). Available isolates were emm typed. We calculated rates and made age- and race-adjusted national projections using census data. We identified 9557 cases (3.8 cases per 100 000 persons per year) with 1116 deaths (case-fatality rate, 11.7%). The case-fatality rates for septic shock, STSS, and NF were 45%, 38%, and 29%, respectively. The annual incidence was highest among persons aged ≥65 years (9.4/100 000) or <1 year (5.3) and among blacks (4.7/100 000). National rates remained steady over 8 years of surveillance. Factors independently associated with death included increasing age, residence in a nursing home, recent surgery, septic shock, NF, meningitis, isolated bacteremia, pneumonia, emm type 1 or 3, and underlying chronic illness or immunosuppression. An estimated 10 649-13 434 cases of invasive GAS infections occur in the United States annually, resulting in 1136-1607 deaths. In a 30-valent M-protein vaccine, emm types accounted for 91% of isolates. The burden of invasive GAS infection in the United States remains substantial. Vaccines under development could have a considerable public health impact. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Strain-dependent induction of epithelial cell oncosis by Campylobacter jejuni is correlated with invasion ability and is independent of cytolethal distending toxin.

PubMed

Kalischuk, Lisa D; Inglis, G Douglas; Buret, Andre G

2007-09-01

Induction of host cell death is thought to play an important role in bacterial pathogenesis. Campylobacter jejuni is a prevalent cause of bacterial enteritis; however, its effects on enterocytes remain unclear. The present study indicates for the first time that C. jejuni induces oncotic, rather than apoptotic death of T84 enterocytes. C. jejuni-treated enterocytes exhibited extensive cytoplasmic vacuolation, rapid (3-6 h) loss of plasma membrane integrity ('cytotoxicity'), loss of mitochondrial transmembrane potential, and ATP depletion. Enterocytes also exhibited increased oligonucleosomal DNA fragmentation, a feature characteristic of apoptosis. However, consistent with a non-apoptotic process, DNA fragmentation and cytotoxicity were not caspase dependent. During apoptosis, caspases mediate cleavage of poly(ADP-ribose) polymerase; however, cleavage was not observed in C. jejuni-treated monolayers. Cytotoxicity, ATP depletion and DNA fragmentation were not prevented by the deletion of the cytolethal distending toxin (CDT) gene, indicating that C. jejuni causes enterocyte oncosis via a mechanism that is CDT independent. The ability to cause oncosis was significantly decreased in a FlaAFlaB mutant (CDT(+)) that was defective in the ability to adhere and invade enterocytes. Analysis of clinical isolates revealed that oncosis was strain dependent and correlated with increased invasive ability. These observations offer new insights into the pathogenesis of C. jejuni infection.

Epidemiology of invasive respiratory disease caused by emerging non-Aspergillus molds in lung transplant recipients.

PubMed

Peghin, M; Monforte, V; Martin-Gomez, M T; Ruiz-Camps, I; Berastegui, C; Saez, B; Riera, J; Solé, J; Gavaldá, J; Roman, A

2016-02-01

Our aim was to assess the impact of positive cultures for non-Aspergillus molds on the risk of progression to invasive fungal infection (IFI), and the effect of prophylactic nebulized liposomal amphotericin B (n-LAB) on these pathogens. This was an observational study (2003-2013) including lung transplant recipients (LTR) receiving lifetime n-LAB prophylaxis, in whom non-Aspergillus molds were isolated on respiratory culture before and after transplantation (minimum 1-year follow-up). We studied 412 patients, with a mean postoperative follow-up of 2.56 years (interquartile range 1.01-4.65). Pre- and post-transplantation respiratory samples were frequently positive for non-Aspergillus molds (11.9% and 16.9% of LTR respectively). Post transplantation, 10 (2.42%) patients developed non-Aspergillus mold infection (4 Scedosporium species, 4 Purpureocillium species, 1 Penicillium species, and 1 Scopulariopsis species); 5 (1.21%) had IFI, with 60% IFI-related mortality. Non-Aspergillus molds with intrinsic amphotericin B (AB) resistance were more commonly isolated in bronchoscopy samples than AB-variably sensitive or AB-sensitive molds (54.5% vs. 25%, P = 0.04) and were associated with a higher risk of infection (56.3% vs. 1.3%%, P < 0.01). In LTR undergoing n-LAB prophylaxis, pre- and post-transplantation isolation of non-Aspergillus molds is frequent, but IFI incidence (1.21%) is low. Purpureocillium is an emerging mold. AB-resistant non-Aspergillus species were found more often in bronchoscopy samples and were associated with a higher risk of infection. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Streptococcal toxic shock syndrome caused by Streptococcus suis serotype 2.

PubMed

Tang, Jiaqi; Wang, Changjun; Feng, Youjun; Yang, Weizhong; Song, Huaidong; Chen, Zhihai; Yu, Hongjie; Pan, Xiuzhen; Zhou, Xiaojun; Wang, Huaru; Wu, Bo; Wang, Haili; Zhao, Huamei; Lin, Ying; Yue, Jianhua; Wu, Zhenqiang; He, Xiaowei; Gao, Feng; Khan, Abdul Hamid; Wang, Jian; Zhao, Guo-Ping; Wang, Yu; Wang, Xiaoning; Chen, Zhu; Gao, George F

2006-05-01

Streptococcus suis serotype 2 (S. suis 2, SS2) is a major zoonotic pathogen that causes only sporadic cases of meningitis and sepsis in humans. Most if not all cases of Streptococcal toxic shock syndrome (STSS) that have been well-documented to date were associated with the non-SS2 group A streptococcus (GAS). However, a recent large-scale outbreak of SS2 in Sichuan Province, China, appeared to be caused by more invasive deep-tissue infection with STSS, characterized by acute high fever, vascular collapse, hypotension, shock, and multiple organ failure. We investigated this outbreak of SS2 infections in both human and pigs, which took place from July to August, 2005, through clinical observation and laboratory experiments. Clinical and pathological characterization of the human patients revealed the hallmarks of typical STSS, which to date had only been associated with GAS infection. Retrospectively, we found that this outbreak was very similar to an earlier outbreak in Jiangsu Province, China, in 1998. We isolated and analyzed 37 bacterial strains from human specimens and eight from pig specimens of the recent outbreak, as well as three human isolates and two pig isolates from the 1998 outbreak we had kept in our laboratory. The bacterial isolates were examined using light microscopy observation, pig infection experiments, multiplex-PCR assay, as well as restriction fragment length polymorphisms (RFLP) and multiple sequence alignment analyses. Multiple lines of evidence confirmed that highly virulent strains of SS2 were the causative agents of both outbreaks. We report, to our knowledge for the first time, two outbreaks of STSS caused by SS2, a non-GAS streptococcus. The 2005 outbreak was associated with 38 deaths out of 204 documented human cases; the 1998 outbreak with 14 deaths out of 25 reported human cases. Most of the fatal cases were characterized by STSS; some of them by meningitis or severe septicemia. The molecular mechanisms underlying these human STSS outbreaks in human beings remain unclear and an objective for further study.

Molecular epidemiology of invasive Candida albicans at a tertiary hospital in northern Taiwan from 2003 to 2011.

PubMed

Wang, Shao-Hung; Shen, Mandy; Lin, Hsin-Chieh; Sun, Pei-Lun; Lo, Hsiu-Jung; Lu, Jang-Jih

2015-11-01

Candida albicans is a common cause of bloodstream fungal infections in hospitalized patients. To investigate its epidemiology, multilocus sequence typing (MLST) was performed on 285 C. albicans bloodstream isolates from patients in Chang Gung Memorial Hospital at Linkou (CGMHL), Taiwan from 2003 to 2011. Among these isolates, the three major diploid sequence types (DSTs) were 693, 659, and 443 with 19, 16, and 13 isolates, respectively. The 179 DSTs were classified into 16 clades by unweighted pair-group method using arithmetic averages (UPGMA). The major ones were clades 1, 4, 3, and 17 (54, 49, 31, and 31 isolates, respectively). Further analyses with eBURST clustered the 285 isolates into 28 clonal complexes (CC). The most common complexes were CC8, CC20, and CC9. DST 693 that had the highest number of isolates was determined to be the cluster founder of CC20, which belonged to clade 3. So far, 33 isolates worldwide including 29 from Taiwan and 4 from Korea, are CC20, suggesting that CC20 is an Asian cluster. Two fluconazole-resistant isolates belonging to CC12 and CC19 were detected. All other CGMHL isolates were susceptible to 5-flucytosine, amphotericin B, anidulfungin, caspofungin, fluconazole, itraconazole, micafungin, posaconazole, and voriconazole. However, CC20 isolates exhibited significantly lower susceptibility to fluconazole. In conclusion, the 285 CGMHL C. albicans isolates displayed geographically clustering with Asian isolates, and most of them are susceptible to common antifungal drugs. Isolates of DST 693, a Taiwanese major genotype belonging to MLST clade 3, were more resistant to fluconazole than other isolates. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Aggregated Antibiograms and Monitoring of Drug-Resistant Streptococcus pneumoniae

PubMed Central

Lexau, Catherine; Baughman, Wendy; Barnes, Brenda; Bennett, Nancy; Cassidy, P. Maureen; Pass, Margaret; Gelling, Lisa; Barrett, Nancy L.; Zell, Elizabeth R.; Whitney, Cynthia G.

2003-01-01

Community-specific antimicrobial susceptibility data may help monitor trends among drug-resistant Streptococcus pneumoniae and guide empiric therapy. Because active, population-based surveillance for invasive pneumococcal disease is accurate but resource intensive, we compared the proportion of penicillin-nonsusceptible isolates obtained from existing antibiograms, a less expensive system, to that obtained from 1 year of active surveillance for Georgia, Tennessee, California, Minnesota, Oregon, Maryland, Connecticut, and New York. For all sites, proportions of penicillin-nonsusceptible isolates from antibiograms were within 10 percentage points (median 3.65) of those from invasive-only isolates obtained through active surveillance. Only 23% of antibiograms distinguished between isolates intermediate and resistant to penicillin; 63% and 57% included susceptibility results for erythromycin and extended-spectrum cephalosporins, respectively. Aggregating existing hospital antibiograms is a simple and relatively accurate way to estimate local prevalence of penicillin-nonsusceptible pneumococcus; however, antibiograms offer limited data on isolates with intermediate and high-level penicillin resistance and isolates resistant to other agents. PMID:14519245

Transfer of scarlet fever-associated elements into the group A Streptococcus M1T1 clone.

PubMed

Ben Zakour, Nouri L; Davies, Mark R; You, Yuanhai; Chen, Jonathan H K; Forde, Brian M; Stanton-Cook, Mitchell; Yang, Ruifu; Cui, Yujun; Barnett, Timothy C; Venturini, Carola; Ong, Cheryl-lynn Y; Tse, Herman; Dougan, Gordon; Zhang, Jianzhong; Yuen, Kwok-Yung; Beatson, Scott A; Walker, Mark J

2015-11-02

The group A Streptococcus (GAS) M1T1 clone emerged in the 1980s as a leading cause of epidemic invasive infections worldwide, including necrotizing fasciitis and toxic shock syndrome. Horizontal transfer of mobile genetic elements has played a central role in the evolution of the M1T1 clone, with bacteriophage-encoded determinants DNase Sda1 and superantigen SpeA2 contributing to enhanced virulence and colonization respectively. Outbreaks of scarlet fever in Hong Kong and China in 2011, caused primarily by emm12 GAS, led to our investigation of the next most common cause of scarlet fever, emm1 GAS. Genomic analysis of 18 emm1 isolates from Hong Kong and 16 emm1 isolates from mainland China revealed the presence of mobile genetic elements associated with the expansion of emm12 scarlet fever clones in the M1T1 genomic background. These mobile genetic elements confer expression of superantigens SSA and SpeC, and resistance to tetracycline, erythromycin and clindamycin. Horizontal transfer of mobile DNA conferring multi-drug resistance and expression of a new superantigen repertoire in the M1T1 clone should trigger heightened public health awareness for the global dissemination of these genetic elements.

Transfer of scarlet fever-associated elements into the group A Streptococcus M1T1 clone

PubMed Central

Ben Zakour, Nouri L.; Davies, Mark R.; You, Yuanhai; Chen, Jonathan H. K.; Forde, Brian M.; Stanton-Cook, Mitchell; Yang, Ruifu; Cui, Yujun; Barnett, Timothy C.; Venturini, Carola; Ong, Cheryl-lynn Y.; Tse, Herman; Dougan, Gordon; Zhang, Jianzhong; Yuen, Kwok-Yung; Beatson, Scott A.; Walker, Mark J.

2015-01-01

The group A Streptococcus (GAS) M1T1 clone emerged in the 1980s as a leading cause of epidemic invasive infections worldwide, including necrotizing fasciitis and toxic shock syndrome123. Horizontal transfer of mobile genetic elements has played a central role in the evolution of the M1T1 clone45, with bacteriophage-encoded determinants DNase Sda16 and superantigen SpeA27 contributing to enhanced virulence and colonization respectively. Outbreaks of scarlet fever in Hong Kong and China in 2011, caused primarily by emm12 GAS8910, led to our investigation of the next most common cause of scarlet fever, emm1 GAS89. Genomic analysis of 18 emm1 isolates from Hong Kong and 16 emm1 isolates from mainland China revealed the presence of mobile genetic elements associated with the expansion of emm12 scarlet fever clones1011 in the M1T1 genomic background. These mobile genetic elements confer expression of superantigens SSA and SpeC, and resistance to tetracycline, erythromycin and clindamycin. Horizontal transfer of mobile DNA conferring multi-drug resistance and expression of a new superantigen repertoire in the M1T1 clone should trigger heightened public health awareness for the global dissemination of these genetic elements. PMID:26522788

[Outbreak of streptococcal toxic shock syndrome in a day care center in Cantabria, Spain, 2006].

PubMed

Ortega-Mendi, Manuel; Martínez-Martínez, Luís; González de Aledo-Linos, Alvaro; Agüero-Balbín, Jesús; Viloria-Raymundo, Luís; Cano-García, M Eliecer; Calvo-Montes, Jorge; Mellado-Encinas, Purificación; Fernández-Rodríguez, Amparo

2008-01-01

Beta hemolytic group A streptococcus only exceptionally produces aggressive disease with high lethality. Even more uncommon is the occurrence of an outbreak. In Spain, no outbreak in child care center has been previously described. Descriptive study of an outbreak of streptococcal toxic shock syndrome (3 cases, one lethal) in a child care center, which motivated the health care intervention with chemoprophylaxis, the closure of the child care center and the study of contacts. We analyzed the determinants of infection in the invasive and non-invasive cases, and the results of the pharyngeal culture of contacts. We identified 3 invasive and 14 non-invasive cases between 40 children attending the child care center (attack rate 42.5%). We studied 19 possible determinants of the infection, finding only an association with being over the age of 24 months and the assistance to the handouts classroom (that of the oldest children). It was not associated with chickenpox. All children attending the child care center, its staff (4 women) and 258 contacts were microbiologically investigated. In 12 children the emm 4 strain was isolated, including 2 of 3 cases with invasive disease. In 13 of 258 contacts other strains of beta hemolytic group A streptococcus were isolated, but in none of them the strain responsible of the outbreak was found. Azytromicin chemoprophylaxis was implemented for all children and contacts, and in those with a positive isolation, the culture was repeated until negative. The invasive strain circulated only in the child care center. Azytromicin chemoprophylaxis eradicated effectively the infection.

A case of descending mediastinitis caused by Streptococcus pyogenes harboring genotype emm25 and sequence type 660.

PubMed

Ohya, Hiroaki; Mori, Nobuaki; Hayashi, Tetsuro; Minami, Shujiro; Higuchi, Akiko; Takahashi, Takashi

2017-06-01

Descending mediastinitis caused by Streptococcus pyogenes (group A streptococcus, GAS) is rare among cases of invasive GAS infection. In this report, we describe a case of a cervical abscess and secondary descending mediastinitis in a previously healthy 39-year-old Japanese man. The patient presented with a 2-week history of a sore throat, and subsequently developed an abscess and descending mediastinitis. We treated the cervical abscess using ampicillin/sulbactam and drainage, and GAS was subsequently isolated in two blood cultures from the patient's admission. Microbiological analyses revealed that the isolate harbored genotype emm25 and sequence type (ST) 660. This strain was susceptible to erythromycin (minimum inhibitory concentration [MIC]: ≤0.12 μg/mL), resistant to minocycline (MIC: >4 μg/mL), and possessed the tet(M) determinant. Although we have reviewed the literature regarding the clinical and microbiological characteristics of descending mediastinitis cause by GAS, little is known regarding epidemiological and clinical characteristics of emm25/ST660 GAS. Furthermore, to best of our knowledge, this is the first reported case of descending mediastinitis caused by emm25/ST660 GAS. Therefore, physicians should be aware of case with a cervical abscess and secondary descending mediastinitis caused by GAS infection, even if the patient is immunocompetent. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Serotype changes and antimicrobial nonsusceptibility rates of invasive and non-invasive Streptococcus pneumoniae isolates after implementation of 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) in Bulgaria.

PubMed

Setchanova, Lena; Murdjeva, Marianna; Stancheva, Iglika; Alexandrova, Alexandra; Sredkova, Maria; Stoeva, Temenuga; Yoneva, Magda; Kurchatova, Anna; Mitov, Ivan

The 10-valent pneumococcal conjugate vaccine (PCV10) has been included in Bulgarian Childhood Immunization Program since 2010. This study aimed to assess serotype distribution and antimicrobial resistance of 198 invasive and non-invasive Streptococcus pneumoniae strains that had been isolated in Bulgaria during 2011-2016 from patients with invasive (IPD) and non-invasive (NIPD) pneumococcal diseases. The most common invasive serotypes were 3 (10.1%), 19F (4.0%), and 7F (3.0%). A significant decrease in the proportion of invasive vaccine types (VTs) from 64.2% to 35.2% was found in comparison with pre-vaccine era. The most common serotypes among middle ear fluids were 3, 19A and 19F (5.6% each), and VTs fell down from 66.4% to 40.0% in post-PCV10 period. Among respiratory isolates, the most prevalent serotypes were some emergent serotypes such as 15A/B/C (5.0%), 19A, and 6C (4.0% each). VTs decreased significantly (16.3%) among vaccinated children compared to unvaccinated children and adults (44.0%). Two non-VTs (19A and 6C) have increased significantly more (p<0.05) in vaccinated children than in unvaccinated patients. The rates of antibiotic nonsusceptible S. pneumoniae in Bulgaria remained high in post-PCV10 era. Among all source of isolates, antimicrobial nonsusceptibility rates were: oral penicillin - 46.5%, trimethoprim-sulfamethoxazole - 45.4%, erythromycin - 43.9%, tetracycline - 37.4%, and multidrug-resistance (MDR) was 44%. The most common MDR serotypes were 19F, 19A, 6A/C, 15A/B/C and 23A. Our results proved that PCV10 vaccination substantially reduced VTs pneumococcal IPD and NIPD. There has been a shift in the distribution of S. pneumoniae serotypes mostly in vaccinated children but also in the whole population and strong serotype-specific antibiotic resistance was observed after vaccine implementation. Therefore, it is important to continue monitoring serotype changes and pneumococcal resistance among all patient ages in addition to aid in determining the long-term effectiveness of PCV10 interventions. Copyright © 2017 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

Immunoglobulin deficiency in patients with Streptococcus pneumoniae or Haemophilus influenzae invasive infections.

PubMed

Martinot, Martin; Oswald, Laetitia; Parisi, Elisabeth; Etienne, Elodie; Argy, Nicolas; Grawey, Isabelle; De Briel, Dominique; Zadeh, Mahsa Mohseni; Federici, Laure; Blaison, Gilles; Koebel, Christelle; Jaulhac, Benoit; Hansmann, Yves; Christmann, Daniel

2014-02-01

Immunoglobulin (Ig) deficiency is a well-known risk factor for Streptococcus pneumoniae or Haemophilus influenzae infections and noteworthy invasive diseases. However, the proportion of these deficiencies in cases of invasive disease is unknown. The objective of this study was to evaluate the rate of Ig deficiency in cases of invasive disease. A prospective study was conducted from January 2008 to October 2010 in two French hospitals. Measurement of Ig levels was carried out in patients hospitalized for invasive diseases. A total of 119 patients were enrolled in the study, with nine cases of H. influenzae and 110 cases of S. pneumoniae invasive disease. There were 18 cases of meningitis, 79 of invasive pneumonia, and 22 other invasive diseases. Forty-five patients (37.8%) had an Ig abnormality, 37 of whom had an Ig deficiency (20 IgG <6g/l, four isolated IgA <0.7g/l, and 13 isolated IgM <0.5g/l), while eight had an elevated monoclonal paraprotein. Nineteen of these 45 patients had a clearly defined Ig abnormality, with five primary deficiencies (three common variable immunodeficiencies and two complete IgA deficiencies) and 14 secondary deficiencies, mainly lymphoproliferative disorders. All these deficiencies were either not known or not substituted. Humoral deficiency is frequent in patients with S. pneumoniae or H. influenzae invasive disease and Ig dosage should be proposed systematically after such infections. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Antagonistic Activity of Lactobacillus Isolates against Salmonella typhi In Vitro

PubMed Central

Abdel-Daim, Amira; Hassouna, Nadia; Hafez, Mohamed; Ashor, Mohamed Seif Aldeen; Aboulwafa, Mohammad M.

2013-01-01

Background. Enteric fever is a global health problem, and rapidly developing resistance to various drugs makes the situation more alarming. The potential use of Lactobacillus to control typhoid fever represents a promising approach, as it may exert protective actions through various mechanisms. Methods. In this study, the probiotic potential and antagonistic activities of 32 Lactobacillus isolates against Salmonella typhi were evaluated. The antimicrobial activity of cell free supernatants of Lactobacillus isolates, interference of Lactobacillus isolates with the Salmonella adherence and invasion, cytoprotective effect of Lactobacillus isolates, and possibility of concurrent use of tested Lactobacillus isolates and antibiotics were evaluated by testing their susceptibilities to antimicrobial agents, and their oxygen tolerance was also examined. Results. The results revealed that twelve Lactobacillus isolates could protect against Salmonella typhi infection through interference with both its growth and its virulence properties, such as adherence, invasion, and cytotoxicity. These Lactobacillus isolates exhibited MIC values for ciprofloxacin higher than those of Salmonella typhi and oxygen tolerance and were identified as Lactobacillus plantarum. Conclusion. The tested Lactobacillus plantarum isolates can be introduced as potential novel candidates that have to be subjected for in vivo and application studies for treatment and control of typhoid fever. PMID:24191248

Fluorescent Amplified-Fragment Length Polymorphism Genotyping of Neisseria meningitidis Identifies Clones Associated with Invasive Disease

PubMed Central

Goulding, Jonathan N.; Hookey, John V.; Stanley, John; Olver, Will; Neal, Keith R.; Ala'Aldeen, Dlawer A. A.; Arnold, Catherine

2000-01-01

Fluorescent amplified-fragment length polymorphism (FAFLP), a genotyping technique with phylogenetic significance, was applied to 123 isolates of Neisseria meningitidis. Nine of these were from an outbreak in a British university; 9 were from a recent outbreak in Pontypridd, Glamorgan; 15 were from sporadic cases of meningococcal disease; 26 were from the National Collection of Type Cultures; 58 were carrier isolates from Ironville, Derbyshire; 1 was a disease isolate from Ironville; and five were representatives of invasive clones of N. meningitidis. FAFLP analysis results were compared with previously published multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) results. FAFLP was able to identify hypervirulent, hyperendemic lineages (invasive clones) of N. meningitidis as well as did MLST. PFGE did not discriminate between two strains from the outbreak that were classified as similar but distinct by FAFLP. The results suggest that high resolution of N. meningitidis for outbreak and other epidemiological analyses is more cost efficient by FAFLP than by sequencing procedures. PMID:11101599

Gene flow contributes to diversification of the major fungal pathogen Candida albicans.

PubMed

Ropars, Jeanne; Maufrais, Corinne; Diogo, Dorothée; Marcet-Houben, Marina; Perin, Aurélie; Sertour, Natacha; Mosca, Kevin; Permal, Emmanuelle; Laval, Guillaume; Bouchier, Christiane; Ma, Laurence; Schwartz, Katja; Voelz, Kerstin; May, Robin C; Poulain, Julie; Battail, Christophe; Wincker, Patrick; Borman, Andrew M; Chowdhary, Anuradha; Fan, Shangrong; Kim, Soo Hyun; Le Pape, Patrice; Romeo, Orazio; Shin, Jong Hee; Gabaldon, Toni; Sherlock, Gavin; Bougnoux, Marie-Elisabeth; d'Enfert, Christophe

2018-06-08

Elucidating population structure and levels of genetic diversity and recombination is necessary to understand the evolution and adaptation of species. Candida albicans is the second most frequent agent of human fungal infections worldwide, causing high-mortality rates. Here we present the genomic sequences of 182 C. albicans isolates collected worldwide, including commensal isolates, as well as ones responsible for superficial and invasive infections, constituting the largest dataset to date for this major fungal pathogen. Although, C. albicans shows a predominantly clonal population structure, we find evidence of gene flow between previously known and newly identified genetic clusters, supporting the occurrence of (para)sexuality in nature. A highly clonal lineage, which experimentally shows reduced fitness, has undergone pseudogenization in genes required for virulence and morphogenesis, which may explain its niche restriction. Candida albicans thus takes advantage of both clonality and gene flow to diversify.

Genomic epidemiology of the emerging pathogen Batrachochytrium dendrobatidis from native and invasive amphibian species in Chile.

PubMed

Valenzuela-Sánchez, A; O'Hanlon, S J; Alvarado-Rybak, M; Uribe-Rivera, D E; Cunningham, A A; Fisher, M C; Soto-Azat, C

2018-04-01

Emerging fungal diseases represent a threat to food security, animal and human health worldwide. Amphibian chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has been associated with catastrophic and well-documented amphibian population declines and extinctions. For the first time, Bd was cultured from native and non-native wild amphibians in Chile. Phylogenomic analyses revealed that Chilean isolates AVS2, AVS4 and AVS7 group within the global panzootic lineage of Bd (BdGPL) in a single highly supported clade that includes a genotype previously isolated from the United Kingdom. Our results extend the known distribution of BdGPL in South America and suggest a single and relatively recent introduction of BdGPL into the country, providing additional support to the role of anthropogenic activity in the global spread of this panzootic lineage. © 2017 Blackwell Verlag GmbH.

TR34/L98H Mutation in CYP51A Gene in Aspergillus fumigatus Clinical Isolates During Posaconazole Prophylaxis: First Case in Korea.

PubMed

Lee, Hyeon-Jeong; Cho, Sung-Yeon; Lee, Dong-Gun; Park, Chulmin; Chun, Hye-Sun; Park, Yeon-Joon

2018-06-01

Azole resistance in Aspergillus fumigatus is an emerging problem, especially in immunocompromised patients. It has been reported worldwide, including in Asia, but has not yet been reported in Korea. Here, we report a case of invasive pulmonary aspergillosis (IPA) caused by azole-resistant A. fumigatus that developed in a hematopoietic stem cell transplantation recipient during posaconazole prophylaxis for immunosuppressive therapy of graft-versus-host diseases. We identified TR34/L98H/S297T/F495L mutation in the CYP51A gene of A. fumigatus clinical isolate obtained from bronchial washing fluid. Minimal inhibitory concentrations for itraconazole, voriconazole, and posaconazole were > 16, 1, and 4 μg/mL, respectively. While IPA improved partially under voriconazole treatment, the patient died from carbapenemase-producing Klebsiella pneumoniae bacteremia. Further epidemiological surveillance studies are warranted.

Multilocus sequence typing scheme versus pulsed-field gel electrophoresis for typing Mycobacterium abscessus isolates.

PubMed

Machado, Gabriel Esquitini; Matsumoto, Cristianne Kayoko; Chimara, Erica; Duarte, Rafael da Silva; de Freitas, Denise; Palaci, Moises; Hadad, David Jamil; Lima, Karla Valéria Batista; Lopes, Maria Luiza; Ramos, Jesus Pais; Campos, Carlos Eduardo; Caldas, Paulo César; Heym, Beate; Leão, Sylvia Cardoso

2014-08-01

Outbreaks of infections by rapidly growing mycobacteria following invasive procedures, such as ophthalmological, laparoscopic, arthroscopic, plastic, and cardiac surgeries, mesotherapy, and vaccination, have been detected in Brazil since 1998. Members of the Mycobacterium chelonae-Mycobacterium abscessus group have caused most of these outbreaks. As part of an epidemiological investigation, the isolates were typed by pulsed-field gel electrophoresis (PFGE). In this project, we performed a large-scale comparison of PFGE profiles with the results of a recently developed multilocus sequence typing (MLST) scheme for M. abscessus. Ninety-three isolates were analyzed, with 40 M. abscessus subsp. abscessus isolates, 47 M. abscessus subsp. bolletii isolates, and six isolates with no assigned subspecies. Forty-five isolates were obtained during five outbreaks, and 48 were sporadic isolates that were not associated with outbreaks. For MLST, seven housekeeping genes (argH, cya, glpK, gnd, murC, pta, and purH) were sequenced, and each isolate was assigned a sequence type (ST) from the combination of obtained alleles. The PFGE patterns of DraI-digested DNA were compared with the MLST results. All isolates were analyzable by both methods. Isolates from monoclonal outbreaks showed unique STs and indistinguishable or very similar PFGE patterns. Thirty-three STs and 49 unique PFGE patterns were identified among the 93 isolates. The Simpson's index of diversity values for MLST and PFGE were 0.69 and 0.93, respectively, for M. abscessus subsp. abscessus and 0.96 and 0.97, respectively, for M. abscessus subsp. bolletii. In conclusion, the MLST scheme showed 100% typeability and grouped monoclonal outbreak isolates in agreement with PFGE, but it was less discriminative than PFGE for M. abscessus. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Species distribution and antifungal susceptibility patterns of Candida isolates from a public tertiary teaching hospital in the Eastern Cape Province, South Africa.

PubMed

Mnge, P; Okeleye, B I; Vasaikar, S D; Apalata, T

2017-05-15

Candida species are the leading cause of invasive fungal infections, and over the past decade there has been an increased isolation of drug resistant Candida species. This study aimed to identify the species distribution of Candida isolates and to determine their unique antifungal susceptibility and resistance patterns. During a cross-sectional study, 209 Candida isolates (recovered from 206 clinical samples) were collected and their species distribution was determined using ChromAgar Candida. The Vitek-2 system (Biomerieux, South Africa) was used to determine minimum inhibitory concentrations (MICs) to azoles (fluconazole, voriconazole), echinocandins (caspofungin, micafungin), polyenes (amphotericin B) and flucytosine. Four species of Candida were isolated, of which C. albicans was the most frequent, isolated in 45.4% (95/209) of the isolates, followed by C. glabrata: 31.1% (65/209). The MICs of the different antifungal drugs varied amongst the species of Candida. From the 130 isolates tested for MICs, 90.77% (112/130) were susceptible to all antifungal drugs and 6.9% (9/130) of the isolates were multi-drug resistant. C. dubliniensis (n=2) isolates were susceptible to all the above mentioned antifungal drugs. There was no significant difference in species distribution amongst clinical specimens and between patients' genders (P>0.05). An increase in MIC values for fluconazole and flucytosine towards the resistance range was observed. To our knowledge, this is the first report on surveillance of Candida species distribution and antifungal susceptibility at a public tertiary teaching hospital in Eastern Cape, South Africa.

Human-aided admixture may fuel ecosystem transformation during biological invasions: theoretical and experimental evidence.

PubMed

Molofsky, Jane; Keller, Stephen R; Lavergne, Sébastien; Kaproth, Matthew A; Eppinga, Maarten B

2014-04-01

Biological invasions can transform our understanding of how the interplay of historical isolation and contemporary (human-aided) dispersal affects the structure of intraspecific diversity in functional traits, and in turn, how changes in functional traits affect other scales of biological organization such as communities and ecosystems. Because biological invasions frequently involve the admixture of previously isolated lineages as a result of human-aided dispersal, studies of invasive populations can reveal how admixture results in novel genotypes and shifts in functional trait variation within populations. Further, because invasive species can be ecosystem engineers within invaded ecosystems, admixture-induced shifts in the functional traits of invaders can affect the composition of native biodiversity and alter the flow of resources through the system. Thus, invasions represent promising yet under-investigated examples of how the effects of short-term evolutionary changes can cascade across biological scales of diversity. Here, we propose a conceptual framework that admixture between divergent source populations during biological invasions can reorganize the genetic variation underlying key functional traits, leading to shifts in the mean and variance of functional traits within invasive populations. Changes in the mean or variance of key traits can initiate new ecological feedback mechanisms that result in a critical transition from a native ecosystem to a novel invasive ecosystem. We illustrate the application of this framework with reference to a well-studied plant model system in invasion biology and show how a combination of quantitative genetic experiments, functional trait studies, whole ecosystem field studies and modeling can be used to explore the dynamics predicted to trigger these critical transitions.

The Epidemiology of Staphylococcus aureus and Panton-Valentine Leucocidin (pvl) in Central Australia, 2006-2010.

PubMed

Hewagama, S; Spelman, T; Woolley, M; McLeod, J; Gordon, D; Einsiedel, L

2016-08-08

The Central Australian Indigenous population has a high incidence of Staphylococcus aureus bacteremia (SAB) but little is known about the local molecular epidemiology. Prospective observational study of bacteremic and nasal colonizing S.aureus isolates between June 2006 to June 2010. All isolates underwent single nucleotide polymorphism (SNP) genotyping and testing for the presence of the Panton-Valentine Leucocidin (pvl) gene. Invasive isolates (n = 97) were predominantly ST93 (26.6 %) and pvl positive (54.3 %), which was associated with skin and soft tissue infections (OR 4.35, 95 % CI 1.16, 16.31). Non-multiresistant MRSA accounted for 31.9 % of bacteremic samples and showed a trend to being healthcare associated (OR 2.16, 95 % CI 0.86, 5.40). Non-invasive isolates (n = 54) were rarely ST93 (1.9 %) or pvl positive (7.4 %). In Central Australia, ST93 was the dominant S.aureus clone, and was frequently pvl positive and associated with an aggressive clinical phenotype. Whether non-nasal carriage is more important with invasive clones or whether colonization occurs only transiently remains to be elucidated.

Significance of CD133 positive cells in four novel HPV-16 positive cervical cancer-derived cell lines and biopsies of invasive cervical cancer.

PubMed

Javed, Shifa; Sharma, Bal Krishan; Sood, Swati; Sharma, Sanjeev; Bagga, Rashmi; Bhattacharyya, Shalmoli; Rayat, Charan Singh; Dhaliwal, Lakhbir; Srinivasan, Radhika

2018-04-02

Cervical cancer is a major cause of cancer-related mortality in women in the developing world. Cancer Stem cells (CSC) have been implicated in treatment resistance and metastases development; hence understanding their significance is important. Primary culture from tissue biopsies of invasive cervical cancer and serial passaging was performed for establishing cell lines. Variable Number Tandem Repeat (VNTR) assay was performed for comparison of cell lines with their parental tissue. Tumorsphere and Aldefluor assays enabled isolation of cancer stem cells (CSC); immunofluorescence and flow cytometry were performed for their surface phenotypic expression in cell lines and in 28 tissue samples. Quantitative real-time PCR for stemness and epithelial-mesenchymal transition (EMT) markers, MTT cytotoxicity assay, cell cycle analysis and cell kinetic studies were performed. Four low-passage novel cell lines designated RSBS-9, - 14 and - 23 from squamous cell carcinoma and RSBS-43 from adenocarcinoma of the uterine cervix were established. All were HPV16+. VNTR assay confirmed their uniqueness and derivation from respective parental tissue. CSC isolated from these cell lines showed CD133 + phenotype. In tissue samples of untreated invasive cervical cancer, CD133 + CSCs ranged from 1.3-23% of the total population which increased 2.8-fold in radiation-resistant cases. Comparison of CD133 + with CD133 - bulk population cells revealed increased tumorsphere formation and upregulation of stemness and epithelial-mesenchymal transition (EMT) markers with no significant difference in cisplatin sensitivity. Low-passage cell lines developed would serve as models for studying tumor biology. Cancer Stem Cells in cervical cancer display CD133 + phenotype and are increased in relapsed cases and hence should be targeted for achieving remission.

First record of two ectoparasitic ciliates of the genus Trichodina (Ciliophora: Trichodinidae) parasitizing gills of an invasive freshwater fish, Micropercops swinhonis, in Tibet.

PubMed

Wang, Zhe; Deng, Qiong; Zhou, Tong; Yang, Hao; Gu, Zemao

2018-07-01

Although high diversity of parasitic ciliates has been reported in China, little is known about the species from high altitude areas, especially in Tibet. To investigate the species of parasitic ciliates in Tibet, a project was initiated in the Chabalang wetland in 2013. Two Trichodina species, namely, Trichodina sp. and T. reticulata Hirschmann & Partsch, 1955, were isolated from gills of an invasive fish, Micropercops swinhonis for the first time. In the present study, we provided the morphological, morphometrical, and molecular characterizations of the two species and conducted the phylogenetic analyses of mobilids based on the small subunit ribosomal RNA gene (SSU rDNA) sequences. Both morphological characters and morphometric data of the T. reticulata agreed well with previous studies. Although two partial SSU rDNA sequences were obtained in the present study, only the sequence of T. reticulata population in the present study was thought to be reliable. The other sequence may not belong to the other species. Thus, we regarded the other species isolated in the present study as Trichodina sp. to avoid the wrong or confused species identification. Morphologically, Trichodina sp. is distinguished mainly by its large body shape with a broad adhesive disk, robust and obliquely quadrilateral blades, and well-developed rays. T. reticulata is mainly characterized with the 8-12 spherical or elliptical granules in the central zone of adhesive disk. Phylogenetic analyses consistently showed the two ectoparasites clustered with freshwater species of the genus Trichodina within the order Mobilida. Our study extended the host range of T. reticulata and supplemented the molecular data. Also, results reveal that invasion of exotic fish may cause a potential threat to native fish by introducing or dispersing parasitic ciliates.

Impact of microbial invasion of amniotic cavity and the type of microorganisms on short-term neonatal outcome in women with preterm labor and intact membranes.

PubMed

Cobo, Teresa; Vives, Irene; Rodríguez-Trujillo, Adriano; Murillo, Clara; Ángeles, Martina A; Bosch, Jordi; Vergara, Andrea; Gratacós, Eduard; Palacio, Montse

2017-05-01

The objective of this study was to evaluate the impact of microbial invasion of the amniotic cavity and the type of microorganisms on pregnancy and short-term neonatal outcomes in women with preterm labor. Prospective observational cohort study including women with preterm labor from 22.0 to 36.0 weeks. Microbial invasion of the amniotic cavity was defined based on amniotic fluid aerobic/anaerobic/mycoplasma cultures, and intra-amniotic inflammation on amniotic fluid interleukin-6 levels. Demographic data and pregnancy outcomes were compared among women exposed to microbial invasion of the amniotic cavity by Ureaplasma spp., women with microbial invasion of the amniotic cavity by other microorganisms, and a No-microbial invasion of the amniotic cavity/No-intra-amniotic inflammation group. The short-term neonatal outcome was evaluated in women delivering after 24.0 weeks. We included 228 women with preterm labor. Microbial invasion of the amniotic cavity occurred in 35% (80/228), 28% (22/80) being caused by Ureaplasma spp. Gestational age at admission and at delivery were significantly earlier and the rate of delivery at <24.0 weeks' gestation and of women who further developed clinical chorioamnionitis were significantly higher in women with microbial invasion of the amniotic cavity by microorganisms other than Ureaplasma spp. However, after 24 weeks, regardless of the microorganisms isolated, the short-term neonatal outcome was similar between women exposed to microbial invasion of the amniotic cavity and the No-microbial invasion of the amniotic cavity/No-intra-amniotic inflammation group when gestational age was considered. Microbial invasion of the amniotic cavity by microorganisms other than Ureaplasma spp. was associated with earlier gestational age at admission and at delivery, and a higher rate of preterm delivery <24.0 weeks and of women who developed clinical chorioamnionitis. However, we did not find differences in the short-term neonatal outcome between women exposed to microbial invasion of the amniotic cavity and the no-microbial invasion of the amniotic cavity/no-intra-amniotic inflammation group delivering after 24.0 weeks' gestation when adjusted by gestational age at delivery. © 2017 Nordic Federation of Societies of Obstetrics and Gynecology.

Invasive plants in 21st Century landscapes.

Treesearch

Valerie Rapp

2005-01-01

A plant species is defined as invasive if it is nonnative to the ecosystem under consideration, and if it causes or is likely to cause economic or environmental harm or harm to human health. Nonnative plant invasions are generally considered to have reached the Pacific Northwest in the mid-1800s with the arrival of European-American settlers. Invasive species such as...

Transmission of Streptococcus pneumoniae in an Urban Slum Community

PubMed Central

Palma, Tania; Ribeiro, Guilherme S.; Pinheiro, Ricardo M; Ribeiro, Cassio Tâmara; Cordeiro, Soraia Machado; da Silva Filho, H. P.; Moschioni, Monica; Thompson, Terry A.; Spratt, Brian; Riley, Lee W.; Barocchi, Michele A.; Reis, Mitermayer G.; Ko, Albert I.

2008-01-01

Background Inhabitants of slum settlements represent a significant proportion of the population at risk for pneumococcal disease in developing countries. Methods We conducted a household survey of pneumococcal carriage among residents of a slum community in the city of Salvador, Brazil. Results Among 262 subjects, 95 (36%) were colonized with S. pneumoniae. Children <5 years of age (OR, 8.0; 95%CI, 3.5-18.6) and those who attended schools (OR 2.7, 95%CI, 1.2-6.0) had significantly higher risk of being colonized. Of 94 isolates obtained from colonized individuals, 51% had serotypes included in the seven-valent pneumococcal conjugate vaccine. Overall, 10% (9 of 94 isolates) were nonsusceptible to penicillin and 28% (27 of 94 isolates) were resistant to cotrimoxazole. BOX-PCR, PFGE and MLST analysis found that 44% of the carriage isolates belonged to 14 distinct clonal groups. Strains of the same clonal group were isolated from multiple members of 9 out of the 39 study households. Nineteen carriage isolates had genotypes that were the same as those identified among 362 strains obtained from active surveillance for meningitis. Conclusions The study's findings indicate that there is significant intra and inter-household spread of S. pneumoniae in the slum community setting. However, a limited number of clones encountered during carriage among slum residents were found to cause invasive disease. PMID:18672297

Molecular Types of Methicillin-Resistant Staphylococcus aureus and Methicillin-Sensitive S. aureus Strains Causing Skin and Soft Tissue Infections and Nasal Colonization, Identified in Community Health Centers in New York City.

PubMed

Pardos de la Gandara, Maria; Raygoza Garay, Juan Antonio; Mwangi, Michael; Tobin, Jonathan N; Tsang, Amanda; Khalida, Chamanara; D'Orazio, Brianna; Kost, Rhonda G; Leinberger-Jabari, Andrea; Coffran, Cameron; Evering, Teresa H; Coller, Barry S; Balachandra, Shirish; Urban, Tracie; Parola, Claude; Salvato, Scott; Jenks, Nancy; Wu, Daren; Burgess, Rhonda; Chung, Marilyn; de Lencastre, Herminia; Tomasz, Alexander

2015-08-01

In November 2011, The Rockefeller University Center for Clinical and Translational Science (CCTS), the Laboratory of Microbiology and Infectious Diseases, and Clinical Directors Network (CDN) launched a research and learning collaborative project with six community health centers in the New York City metropolitan area to determine the nature (clonal type) of community-acquired Staphylococcus aureus strains causing skin and soft tissue infections (SSTIs). Between November 2011 and March 2013, wound and nasal samples from 129 patients with active SSTIs suspicious for S. aureus were collected and characterized by molecular typing techniques. In 63 of 129 patients, the skin wounds were infected by S. aureus: methicillin-resistant S. aureus (MRSA) was recovered from 39 wounds and methicillin-sensitive S. aureus (MSSA) was recovered from 24. Most-46 of the 63-wound isolates belonged to the CC8/Panton-Valentine leukocidin-positive (PVL(+)) group of S. aureus clone USA300: 34 of these strains were MRSA and 12 were MSSA. Of the 63 patients with S. aureus infections, 30 were also colonized by S. aureus in the nares: 16 of the colonizing isolates were MRSA, and 14 were MSSA, and the majority of the colonizing isolates belonged to the USA300 clonal group. In most cases (70%), the colonizing isolate belonged to the same clonal type as the strain involved with the infection. In three of the patients, the identity of invasive and colonizing MRSA isolates was further documented by whole-genome sequencing. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Characterization of nasopharyngeal isolates of type b Haemophilus influenzae from Delhi

PubMed Central

Saikia, Kandarpa K.; Das, Bimal K.; Bewal, Ramesh K.; Kapil, Arti; Arora, N.K.; Sood, Seema

2012-01-01

Background & objectives: Haemophilus influenzae is an important cause of mortality and morbidity among young children in developing countries. Increasing incidence of antibiotic resistance especially production of extended spectrum beta lactamase (ESBL) has made treatment and management of H. influenzae infection more difficult. Nasopharyngeal H. influenzae isolates are excellent surrogate for determination of antibiotic resistance prevalent among invasive H. influenzae isolates. In this study, we characterized nasopharyngeal H. influenzae isolates obtained from healthy school going children in Delhi. Methods: Nasopharyngeal H. influenzae isolates were collected from healthy school going children and subjected to serotyping, fimbrial typing and antibiogram profiling. ESBL production was recorded using phenotypic as well as molecular methods. Multi locus sequence typing (MLST) of 13 representative nasopharyngeal H. influenzae isolates was performed as per guidelines. Results: A significant proportion (26 of 80, 32.5%) of nasopharyngeal isolates of H. influenzae were identified as serotype b. Fimbrial gene (hifA) was detected in 23 (28.75%) isolates. Resistance against commonly prescribed antibiotics (Amp, Tet, Chloro, Septran, Cephalexin) were observed to be high among the nasopharyngeal commensal H. influenzae. Extended spectrum beta lactamase (ESBL) production was observed in a five (6.25%) isolates by both double disk diffusion and molecular typing. MLST identified several novel alleles as well as novel sequence types. Interpretation & conclusions: Our findings showed high resistance against common antibiotics and detection of ESBL in nasopharyngeal H. influenzae isolates collected from normal healthy school going children in Delhi. Detection of H. influenzae type b capsular gene and the presence of fimbrial gene (hif A) suggest virulence potential of these isolates. Discovery of novel alleles and presence of new sequence types (STs) among nasopharyngeal H. influenzae isolates may suggest wider genetic diversity. PMID:23287135

Characterization of Aspergillus fumigatus Isolates from Air and Surfaces of the International Space Station

PubMed Central

Knox, Benjamin P.; Blachowicz, Adriana; Romsdahl, Jillian; Huttenlocher, Anna; Wang, Clay C. C.; Keller, Nancy P.

2016-01-01

ABSTRACT One mission of the Microbial Observatory Experiments on the International Space Station (ISS) is to examine the traits and diversity of fungal isolates to gain a better understanding of how fungi may adapt to microgravity environments and how this may affect interactions with humans in a closed habitat. Here, we report an initial characterization of two isolates, ISSFT-021 and IF1SW-F4, of Aspergillus fumigatus collected from the ISS and a comparison to the experimentally established clinical isolates Af293 and CEA10. Whole-genome sequencing of ISSFT-021 and IF1SW-F4 showed 54,960 and 52,129 single nucleotide polymorphisms, respectively, compared to Af293, which is consistent with observed genetic heterogeneity among sequenced A. fumigatus isolates from diverse clinical and environmental sources. Assessment of in vitro growth characteristics, secondary metabolite production, and susceptibility to chemical stresses revealed no outstanding differences between ISS and clinical strains that would suggest special adaptation to life aboard the ISS. Virulence assessment in a neutrophil-deficient larval zebrafish model of invasive aspergillosis revealed that both ISSFT-021 and IF1SW-F4 were significantly more lethal than Af293 and CEA10. Taken together, these genomic, in vitro, and in vivo analyses of two A. fumigatus strains isolated from the ISS provide a benchmark for future investigations of these strains and for continuing research on specific microbial isolates from manned space environments. IMPORTANCE As durations of manned space missions increase, it is imperative to understand the long-term consequence of microbial exposure on human health in a closed human habitat. To date, studies aimed at bacterial and fungal contamination of space vessels have highlighted species compositions biased toward hardy, persistent organisms capable of withstanding harsh conditions. In the current study, we assessed traits of two independent Aspergillus fumigatus strains isolated from the International Space Station. Ubiquitously found in terrestrial soil and atmospheric environments, A. fumigatus is a significant opportunistic fungal threat to human health, particularly among the immunocompromised. Using two well-known clinical isolates of A. fumigatus as comparators, we found that both ISS isolates exhibited normal in vitro growth and chemical stress tolerance yet caused higher lethality in a vertebrate model of invasive disease. These findings substantiate the need for additional studies of physical traits and biological activities of microbes adapted to microgravity and other extreme extraterrestrial conditions. PMID:27830189

Characterization of Aspergillus fumigatus Isolates from Air and Surfaces of the International Space Station.

PubMed

Knox, Benjamin P; Blachowicz, Adriana; Palmer, Jonathan M; Romsdahl, Jillian; Huttenlocher, Anna; Wang, Clay C C; Keller, Nancy P; Venkateswaran, Kasthuri

2016-01-01

One mission of the Microbial Observatory Experiments on the International Space Station (ISS) is to examine the traits and diversity of fungal isolates to gain a better understanding of how fungi may adapt to microgravity environments and how this may affect interactions with humans in a closed habitat. Here, we report an initial characterization of two isolates, ISSFT-021 and IF1SW-F4, of Aspergillus fumigatus collected from the ISS and a comparison to the experimentally established clinical isolates Af293 and CEA10. Whole-genome sequencing of ISSFT-021 and IF1SW-F4 showed 54,960 and 52,129 single nucleotide polymorphisms, respectively, compared to Af293, which is consistent with observed genetic heterogeneity among sequenced A. fumigatus isolates from diverse clinical and environmental sources. Assessment of in vitro growth characteristics, secondary metabolite production, and susceptibility to chemical stresses revealed no outstanding differences between ISS and clinical strains that would suggest special adaptation to life aboard the ISS. Virulence assessment in a neutrophil-deficient larval zebrafish model of invasive aspergillosis revealed that both ISSFT-021 and IF1SW-F4 were significantly more lethal than Af293 and CEA10. Taken together, these genomic, in vitro , and in vivo analyses of two A. fumigatus strains isolated from the ISS provide a benchmark for future investigations of these strains and for continuing research on specific microbial isolates from manned space environments. IMPORTANCE As durations of manned space missions increase, it is imperative to understand the long-term consequence of microbial exposure on human health in a closed human habitat. To date, studies aimed at bacterial and fungal contamination of space vessels have highlighted species compositions biased toward hardy, persistent organisms capable of withstanding harsh conditions. In the current study, we assessed traits of two independent Aspergillus fumigatus strains isolated from the International Space Station. Ubiquitously found in terrestrial soil and atmospheric environments, A. fumigatus is a significant opportunistic fungal threat to human health, particularly among the immunocompromised. Using two well-known clinical isolates of A. fumigatus as comparators, we found that both ISS isolates exhibited normal in vitro growth and chemical stress tolerance yet caused higher lethality in a vertebrate model of invasive disease. These findings substantiate the need for additional studies of physical traits and biological activities of microbes adapted to microgravity and other extreme extraterrestrial conditions.

Streptococcus agalactiae septicemia in a patient with diabetes and hepatic cirrhosis

PubMed Central

Ferreira, Cristiane Rúbia

2015-01-01

Streptococcus agalactiae is a well-known pathogen during pregnancy and in neonates. Among non-pregnant adults, invasive infection, although rare, is showing increasing frequency, especially in chronically ill, immunosuppressed, or older patients. Although rare, the clinical features of meningeal infection caused by S. agalactiae are similar to other bacterial meningitis. The authors report the case of a middle-aged man previously diagnosed with hypertension, diabetes mellitus, and alcoholic liver cirrhosis, who was admitted at the emergency department with a Glasgow Coma Scale of 11/12, generalized spasticity, bilateral Babinski sign, and hypertension. The clinical outcome was bad, with refractory shock and death within 24 hours of hospitalization. The bacteriological work-up isolated S. agalactiae in the cerebral spinal fluid (CSF), blood, and urine. An autopsy revealed meningoencephalitis, acute myocardial infarction, and pyelonephritis due to septic emboli. The authors point out the atypical CSF findings, the rapid fatal outcome, and the importance of including this pathogen among the etiologic possibilities of invasive infections in this group of patients. PMID:26894044

Current status and future perspectives on molecular and serological methods in diagnostic mycology.

PubMed

Lau, Anna; Chen, Sharon; Sleiman, Sue; Sorrell, Tania

2009-11-01

Invasive fungal infections are an important cause of infectious morbidity. Nonculture-based methods are increasingly used for rapid, accurate diagnosis to improve patient outcomes. New and existing DNA amplification platforms have high sensitivity and specificity for direct detection and identification of fungi in clinical specimens. Since laboratories are increasingly reliant on DNA sequencing for fungal identification, measures to improve sequence interpretation should support validation of reference isolates and quality control in public gene repositories. Novel technologies (e.g., isothermal and PNA FISH methods), platforms enabling high-throughput analyses (e.g., DNA microarrays and Luminex xMAP) and/or commercial PCR assays warrant further evaluation for routine diagnostic use. Notwithstanding the advantages of molecular tests, serological assays remain clinically useful for patient management. The serum Aspergillus galactomannan test has been incorporated into diagnostic algorithms of invasive aspergillosis. Both the galactomannan and the serum beta-D-glucan test have value for diagnosing infection and monitoring therapeutic response.

Technical Insights into Highly Sensitive Isolation and Molecular Characterization of Fixed and Live Circulating Tumor Cells for Early Detection of Tumor Invasion

PubMed Central

Laget, Sophie; Dhingra, Dalia M.; BenMohamed, Fatima; Capiod, Thierry; Osteras, Magne; Farinelli, Laurent; Jackson, Stephen; Paterlini-Bréchot, Patrizia

2017-01-01

Circulating Tumor Cells (CTC) and Circulating Tumor Microemboli (CTM) are Circulating Rare Cells (CRC) which herald tumor invasion and are expected to provide an opportunity to improve the management of cancer patients. An unsolved technical issue in the CTC field is how to obtain highly sensitive and unbiased collection of these fragile and heterogeneous cells, in both live and fixed form, for their molecular study when they are extremely rare, particularly at the beginning of the invasion process. We report on a new protocol to enrich from blood live CTC using ISET® (Isolation by SizE of Tumor/Trophoblastic Cells), an open system originally developed for marker-independent isolation of fixed tumor cells. We have assessed the impact of our new enrichment method on live tumor cells antigen expression, cytoskeleton structure, cell viability and ability to expand in culture. We have also explored the ISET® in vitro performance to collect intact fixed and live cancer cells by using spiking analyses with extremely low number of fluorescent cultured cells. We describe results consistently showing the feasibility of isolating fixed and live tumor cells with a Lower Limit of Detection (LLOD) of one cancer cell per 10 mL of blood and a sensitivity at LLOD ranging from 83 to 100%. This very high sensitivity threshold can be maintained when plasma is collected before tumor cells isolation. Finally, we have performed a comparative next generation sequencing (NGS) analysis of tumor cells before and after isolation from blood and culture. We established the feasibility of NGS analysis of single live and fixed tumor cells enriched from blood by our system. This study provides new protocols for detection and characterization of CTC collected from blood at the very early steps of tumor invasion. PMID:28060956

Clinical, epidemiological, and microbiological features of Vibrio vulnificus biogroup 3 causing outbreaks of wound infection and bacteraemia in Israel. Israel Vibrio Study Group.

PubMed

Bisharat, N; Agmon, V; Finkelstein, R; Raz, R; Ben-Dror, G; Lerner, L; Soboh, S; Colodner, R; Cameron, D N; Wykstra, D L; Swerdlow, D L; Farmer, J J

1999-10-23

Vibrio vulnificus is a gram-negative bacterium that causes septicaemia and wound infection. Cases occur sporadically, and no previous outbreaks due to a common source or a clonal strain have been reported. In the summer and autumn of 1996 and 1997, an outbreak of invasive V. vulnificus infection occurred in Israel in people who had recently handled fresh, whole fish purchased from artificial fish-ponds. We reviewed clinical and epidemiological information, and undertook an environmental investigation to assess disease characteristics, modes of transmission, phenotypic characteristics of the bacterium, and fish-marketing policy. The clonal nature of 19 isolates was studied by biotyping, pulsed-field gel electrophoresis, and restriction-fragment length polymorphism (RFLP) analysis of a PCR fragment. During 1996-97, 62 cases of wound infection and bacteraemia occurred. 57 patients developed cellulitis, four had necrotising fasciitis, and one developed osteomyelitis. In all cases, the fish were cultivated in inland fish-ponds. In the summer of 1996, fish-pond managers initiated a new marketing policy, in which fish were sold alive instead of being packed in ice. Phenotypically, the isolates had five atypical biochemical test results. The isolates were non-typeable by pulsed-field gel electrophoresis, and all had the same PCR-RFLP pattern which had not been seen previously. The cause of the outbreak was a new strain of V. vulnificus, classified as biogroup 3. A new fish-marketing policy that began in 1996 may have exposed susceptible people to the organism.

Nasopharyngeal carriage of pneumococci in Gambian children and in their families.

PubMed

Lloyd-Evans, N; O'Dempsey, T J; Baldeh, I; Secka, O; Demba, E; Todd, J E; Mcardle, T F; Banya, W S; Greenwood, B M

1996-10-01

Nasopharyngeal carriage of pneumococci is prevalent among children in developing countries but little is known about the relationship of nasopharyngeal carriage to invasive disease or about the way in which pneumococci spread within households. To determine the prevalence of nasopharyngeal carriage in healthy and sick Gambian children and to investigate transmission within households. Nasopharyngeal swabs were obtained by the per nasal route and cultured for pneumococci on selective media. Pneumococci were serotyped with the use of latex particles coated with type-specific antisera. Pneumococci were isolated from the nasopharynx of 73 (90.1%) of 81 children with invasive pneumococcal disease, 86 (76.1%) of 113 healthy, age-matched control children and 911 (85.1%) of 1071 sick children. Pneumococci belonging to serotypes 1, 14 and 12 were isolated significantly more frequently from cases than from matched controls. In 43 (76.8%) of 56 children with invasive disease, pneumococci isolated from the nasopharynx and from the blood or other sterile site belonged to the same serotype. Pneumococci of the same serotype as the bacterium responsible for invasive disease in a child were obtained from 72 (8.5%) of 843 family members, most frequently from young siblings of the case patients. Nasopharyngeal carriage of pneumococci is more prevalent among young Gambian children than among adults and invasive infections are probably acquired more frequently from siblings than from parents. However, further studies are needed to confirm this hypothesis with more discriminating markers than polysaccharide serotyping.

Glucose & sodium chloride induced biofilm production & ica operon in clinical isolates of staphylococci.

PubMed

Agarwal, Astha; Jain, Amita

2013-01-01

All colonizing and invasive staphylococcal isolates may not produce biofilm but may turn biofilm producers in certain situations due to change in environmental factors. This study was done to test the hypothesis that non biofilm producing clinical staphylococci isolates turn biofilm producers in presence of sodium chloride (isotonic) and high concentration of glucose, irrespective of presence or absence of ica operon. Clinical isolates of 100 invasive, 50 colonizing and 50 commensal staphylococci were tested for biofilm production by microtiter plate method in different culture media (trypticase soy broth alone or supplemented with 0.9% NaCl/ 5 or 10% glucose). All isolates were tested for the presence of ica ADBC genes by PCR. Biofilm production significantly increased in the presence of glucose and saline, most, when both glucose and saline were used together. All the ica positive staphylococcal isolates and some ica negative isolates turned biofilm producer in at least one of the tested culture conditions. Those remained biofilm negative in different culture conditions were all ica negative. The present results showed that the use of glucose or NaCl or combination of both enhanced biofilm producing capacity of staphylococcal isolates irrespective of presence or absence of ica operon.

Multi-scale modelling of the dynamics of cell colonies: insights into cell-adhesion forces and cancer invasion from in silico simulations.

PubMed

Schlüter, Daniela K; Ramis-Conde, Ignacio; Chaplain, Mark A J

2015-02-06

Studying the biophysical interactions between cells is crucial to understanding how normal tissue develops, how it is structured and also when malfunctions occur. Traditional experiments try to infer events at the tissue level after observing the behaviour of and interactions between individual cells. This approach assumes that cells behave in the same biophysical manner in isolated experiments as they do within colonies and tissues. In this paper, we develop a multi-scale multi-compartment mathematical model that accounts for the principal biophysical interactions and adhesion pathways not only at a cell-cell level but also at the level of cell colonies (in contrast to the traditional approach). Our results suggest that adhesion/separation forces between cells may be lower in cell colonies than traditional isolated single-cell experiments infer. As a consequence, isolated single-cell experiments may be insufficient to deduce important biological processes such as single-cell invasion after detachment from a solid tumour. The simulations further show that kinetic rates and cell biophysical characteristics such as pressure-related cell-cycle arrest have a major influence on cell colony patterns and can allow for the development of protrusive cellular structures as seen in invasive cancer cell lines independent of expression levels of pro-invasion molecules.

Multi-scale modelling of the dynamics of cell colonies: insights into cell-adhesion forces and cancer invasion from in silico simulations

PubMed Central

Schlüter, Daniela K.; Ramis-Conde, Ignacio; Chaplain, Mark A. J.

2015-01-01

Studying the biophysical interactions between cells is crucial to understanding how normal tissue develops, how it is structured and also when malfunctions occur. Traditional experiments try to infer events at the tissue level after observing the behaviour of and interactions between individual cells. This approach assumes that cells behave in the same biophysical manner in isolated experiments as they do within colonies and tissues. In this paper, we develop a multi-scale multi-compartment mathematical model that accounts for the principal biophysical interactions and adhesion pathways not only at a cell–cell level but also at the level of cell colonies (in contrast to the traditional approach). Our results suggest that adhesion/separation forces between cells may be lower in cell colonies than traditional isolated single-cell experiments infer. As a consequence, isolated single-cell experiments may be insufficient to deduce important biological processes such as single-cell invasion after detachment from a solid tumour. The simulations further show that kinetic rates and cell biophysical characteristics such as pressure-related cell-cycle arrest have a major influence on cell colony patterns and can allow for the development of protrusive cellular structures as seen in invasive cancer cell lines independent of expression levels of pro-invasion molecules. PMID:25519994

Characterization of Salmonella Typhimurium of animal origin obtained from the National Antimicrobial Resistance Monitoring System.

PubMed

Zhao, S; Fedorka-Cray, P J; Friedman, S; McDermott, P F; Walker, R D; Qaiyumi, S; Foley, S L; Hubert, S K; Ayers, S; English, L; Dargatz, D A; Salamone, B; White, D G

2005-01-01

Salmonella Typhimurium remains one of the most common causes of salmonellosis in animals and humans in the United States. The emergence of multi-drug resistant Salmonella reduces the therapeutic options in cases of invasive infections, and has been shown to be associated with an increased burden of illness. In this study, 588 S. Typhimurium (including var. Copenhagen) isolates obtained from either animal diagnostic specimens (n = 199) or food animals after slaughter/processing (n = 389) were examined for antimicrobial susceptibility, presence of class-1 integrons, and characterized using pulsed-field gel electrophoresis and phage typing. Seventy-six percent (448/588) of isolates were resistant to at least one antimicrobial. Salmonella isolates displayed resistance most often to streptomycin (63%), tetracycline (61%), ampicillin (61%), and to a lesser extent, chloramphenicol (36%), ceftiofur (15%), gentamicin (9%), and nalidixic acid (4%), with more resistance observed among diagnostic isolates. Salmonella recovered from turkeys (n = 38) exhibited the highest rates of resistance, with 92% of isolates resistant to least one antimicrobial, and 58% resistant to > or =10 antimicrobials. Class 1 integrons were present in 51% of all isolates. Five integron associated resistance genes (aadA, aadB, pse-1, oxa-2 and dhfr) were identified. A total of 311 PFGE patterns were generated using XbaI, indicating a genetically diverse population. The largest PFGE cluster contained 146 isolates, including DT104 isolates obtained from all seven animal species. Results demonstrated a varied spectrum of antimicrobial resistance, including several multidrug resistant clonal groups, among S. Typhimurium and S. Typhimurium var. Copenhagen isolates recovered from both diagnostic and slaughter/processing samples.

Destruction of the hepatocyte junction by intercellular invasion of Leptospira causes jaundice in a hamster model of Weil's disease.

PubMed

Miyahara, Satoshi; Saito, Mitsumasa; Kanemaru, Takaaki; Villanueva, Sharon Y A M; Gloriani, Nina G; Yoshida, Shin-ichi

2014-08-01

Weil's disease, the most severe form of leptospirosis, is characterized by jaundice, haemorrhage and renal failure. The mechanisms of jaundice caused by pathogenic Leptospira remain unclear. We therefore aimed to elucidate the mechanisms by integrating histopathological changes with serum biochemical abnormalities during the development of jaundice in a hamster model of Weil's disease. In this work, we obtained three-dimensional images of infected hamster livers using scanning electron microscope together with freeze-cracking and cross-cutting methods for sample preparation. The images displayed the corkscrew-shaped bacteria, which infiltrated the Disse's space, migrated between hepatocytes, detached the intercellular junctions and disrupted the bile canaliculi. Destruction of bile canaliculi coincided with the elevation of conjugated bilirubin, aspartate transaminase and alkaline phosphatase levels in serum, whereas serum alanine transaminase and γ-glutamyl transpeptidase levels increased slightly, but not significantly. We also found in ex vivo experiments that pathogenic, but not non-pathogenic leptospires, tend to adhere to the perijunctional region of hepatocyte couplets isolated from hamsters and initiate invasion of the intercellular junction within 1 h after co-incubation. Our results suggest that pathogenic leptospires invade the intercellular junctions of host hepatocytes, and this invasion contributes in the disruption of the junction. Subsequently, bile leaks from bile canaliculi and jaundice occurs immediately. Our findings revealed not only a novel pathogenicity of leptospires, but also a novel mechanism of jaundice induced by bacterial infection. © 2014 The Authors. International Journal of Experimental Pathology © 2014 International Journal of Experimental Pathology.

Alternatives to vancomycin for the treatment of methicillin-resistant Staphylococcus aureus infections.

PubMed

Micek, Scott T

2007-09-15

Vancomycin remains the reference standard for the treatment of systemic infection caused by methicillin-resistant Staphylococcus aureus (MRSA). However, as a result of limited tissue distribution, as well as the emergence of isolates with reduced susceptibility and in vitro resistance to vancomycin, the need for alternative therapies that target MRSA has become apparent. New treatment options for invasive MRSA infections include linezolid, daptomycin, tigecycline, and quinupristin/dalfopristin. Additionally, a number of new anti-MRSA compounds are in development, including novel glycopeptides (dalbavancin, telavancin, and oritavancin), ceftobiprole, and iclaprim. The present article will review clinical issues surrounding the newly marketed and investigational agents with activity against MRSA.

Genetic diversity and antifungal susceptibility of Fusarium isolates in onychomycosis.

PubMed

Rosa, Priscila D; Heidrich, Daiane; Corrêa, Carolina; Scroferneker, Maria Lúcia; Vettorato, Gerson; Fuentefria, Alexandre M; Goldani, Luciano Z

2017-09-01

Fusarium species have emerged as an important human pathogen in skin disease, onychomycosis, keratitis and invasive disease. Onychomycosis caused by Fusarium spp. The infection has been increasingly described in the immunocompetent and immunosuppressed hosts. Considering onychomycosis is a difficult to treat infection, and little is known about the genetic variability and susceptibility pattern of Fusarium spp., further studies are necessary to understand the pathogenesis and better to define the appropriate antifungal treatment for this infection. Accordingly, the objective of this study was to describe the in vitro susceptibility to different antifungal agents and the genetic diversity of 35 Fusarium isolated from patients with onychomycosis. Fusarium spp. were isolated predominantly from female Caucasians, and the most frequent anatomical location was the nail of the hallux. Results revealed that 25 (71.4%) of isolates belonged to the Fusarium solani species complex, followed by 10 (28.5%) isolates from the Fusarium oxysporum species complex. Noteworthy, the authors report the first case of Neocosmospora rubicola isolated from a patient with onychomycosis. Amphotericin B was the most effective antifungal agent against the majority of isolates (60%, MIC ≤4 μg/mL), followed by voriconazole (34.2%, MIC ≤4 μg/mL). In general, Fusarium species presented MIC values >64 μg/mL for fluconazole, itraconazole and terbinafine. Accurate pathogen identification, characterisation and susceptibility testing provide a better understanding of pathogenesis of Fusarium in onychomycosis. © 2017 Blackwell Verlag GmbH.

Six-Month Multicenter Study on Invasive Infections Due to Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis in Argentina

PubMed Central

Lopardo, Horacio A.; Vidal, Patricia; Sparo, Monica; Jeric, Paola; Centron, Daniela; Facklam, Richard R.; Paganini, Hugo; Pagniez, N. Gaston; Lovgren, Marguerite; Beall, Bernard

2005-01-01

During a 6-month period, 95 invasive infections due to Streptococcus pyogenes and group C or group G Streptococcus dysgalactiae subsp. equisimilis were recorded from 40 centers of 16 cities in Argentina. We describe here epidemiologic data available for 55 and 19 patients, respectively, associated with invasive infections due to S. pyogenes and S. dysgalactiae subsp. equisimilis. The associated isolates and 58 additional pharyngeal isolates were genotyped and subjected to serologic and/or antibiotic susceptibility testing. Group A streptococcal emm type distribution and strain association with toxic shock appeared to differ somewhat from results found within the United States; however, serologic characterization and sof sequence typing suggested that emm types found in both countries are reflective of shared clonal types. PMID:15695683

American origin of Cupriavidus bacteria associated with invasive Mimosa legumes in the Philippines.

PubMed

Andrus, Alexis D; Andam, Cheryl; Parker, Matthew A

2012-06-01

To identify the origins of Cupriavidus nodule symbionts associated with two invasive Mimosa species in the Philippines, 22 isolates were sequenced for portions of three chromosomal genes and two symbiotic plasmid loci. Eleven isolates were identical at all gene loci (2713 bp) to a lineage found in Central America. Four other Philippine isolates were identical to a second Cupriavidus lineage distributed both in Central America and in the Caribbean. None of the remaining Philippine strains had more than 0.6% sequence divergence from American Cupriavidus lineages. These results imply that the Philippine population was founded by multiple introductions from the native range of their Mimosa hosts. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Raman spectroscopy for bacterial identification and characterization

NASA Astrophysics Data System (ADS)

Bernatová, Silvie; Samek, Ota; Pilát, Zdeněk.; Šerý, Mojmír.; Ježek, Jan; Krzyžánek, Vladislav; Zemánek, Pavel; Ružička, Filip

2012-01-01

The main goal of our investigation is to use Raman tweezers technique so that the responce of Raman scattering on microorganisms suspended in liquid media (bacteria, algae and yeast cells in microfluidic chips) can be used to identify different species. The investigations presented here include identification of different bacteria strains (biofilm-positive and biofilm-negative) and yeast cells by using principal component analysis (PCA). The main driving force behind our investigation was a common problem in the clinical microbiology laboratory - how to distinguish between contaminant and invasive isolates. Invasive bacterial/yeast isolates can be assumed to form a biofilm, while isolates which do not form a biofilm can be treated as contaminant. Thus, the latter do not represent an important virulence factor.

Antimicrobial susceptibilities and capsular types of invasive Streptococcus pneumoniae isolated in children in Mexico City.

PubMed

Echániz-Aviles, G; Velázquez-Meza, M E; Carnalla-Barajas, M N; Soto-Noguerón, A; Solórzano-Santos, F; Pérez Miravete, A; Gatica-Marquina, R; di Fabio, J L

1997-01-01

As part of the Sistema Regional de Vacunas (SIREVA) initiative, we conducted a surveillance study to determine the relative prevalence of capsular types of Streptococcus pneumoniae and antimicrobial susceptibility of invasive isolates in children less than 5 years old. We collected 220 isolates and found 33 of the 90 known types, with type 23F as the most common followed by types 6A+B, 14, 19F, and 19A. High penicillin resistance was found in 49 strains (22.2%), 31 belonging to type 23F. Twenty-nine (13.1%) were resistant to erythromycin, 95 (43.1%) were resistant to chloramphenicol, and 24 (10.9%) were resistant to cefotaxime. No strains were resistant to vancomycin.

Association of a Bacteriophage with Meningococcal Disease in Young Adults

PubMed Central

Gray, Stephen J.; Kaczmarski, Edward B.; McCarthy, Noel D.; Nassif, Xavier; Maiden, Martin C. J.; Tinsley, Colin R.

2008-01-01

Despite being the agent of life-threatening meningitis, Neisseria meningitidis is usually carried asymptomatically in the nasopharynx of humans and only occasionally causes disease. The genetic bases for virulence have not been entirely elucidated and the search for new virulence factors in this species is hampered by the lack of an animal model representative of the human disease. As an alternative strategy we employ a molecular epidemiological approach to establish a statistical association of a candidate virulence gene with disease in the human population. We examine the distribution of a previously-identified genetic element, a temperate bacteriophage, in 1288 meningococci isolated from cases of disease and asymptomatic carriage. The phage was over-represented in disease isolates from young adults indicating that it may contribute to invasive disease in this age group. Further statistical analysis indicated that between 20% and 45% of the pathogenic potential of the five most common disease-causing meningococcal groups was linked to the presence of the phage. In the absence of an animal model of human disease, this molecular epidemiological approach permitted the estimation of the influence of the candidate virulence factor. Such an approach is particularly valuable in the investigation of exclusively human diseases. PMID:19065260

Identification and characterization of multidrug-resistant Salmonella enterica serotype Albert isolates in the United States.

PubMed

Folster, Jason P; Campbell, Davina; Grass, Julian; Brown, Allison C; Bicknese, Amelia; Tolar, Beth; Joseph, Lavin A; Plumblee, Jodie R; Walker, Carrie; Fedorka-Cray, Paula J; Whichard, Jean M

2015-05-01

Salmonella enterica is one of the most common causes of bacterial foodborne illness in the United States. Although most Salmonella infections are self-limiting, antimicrobial treatment of invasive salmonellosis is critical. The primary antimicrobial treatment options include fluoroquinolones or extended-spectrum cephalosporins, and resistance to these antimicrobial drugs may complicate treatment. At present, S. enterica is composed of more than 2,600 unique serotypes, which vary greatly in geographic prevalence, ecological niche, and the ability to cause human disease, and it is important to understand and mitigate the source of human infection, particularly when antimicrobial resistance is found. In this study, we identified and characterized 19 S. enterica serotype Albert isolates collected from food animals, retail meat, and humans in the United States during 2005 to 2013. All five isolates from nonhuman sources were obtained from turkeys or ground turkey, and epidemiologic data suggest poultry consumption or live-poultry exposure as the probable source of infection. S. enterica serotype Albert also appears to be geographically localized to the midwestern United States. All 19 isolates displayed multidrug resistance, including decreased susceptibility to fluoroquinolones and resistance to extended-spectrum cephalosporins. Turkeys are a likely source of multidrug-resistant S. enterica serotype Albert, and circulation of resistance plasmids, as opposed to the expansion of a single resistant strain, is playing a role. More work is needed to understand why these resistance plasmids spread and how their presence and the serotype they reside in contribute to human disease. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Complete Genome Sequence of the Crohn's Disease-Associated Adherent-Invasive Escherichia coliStrain HM605▿

PubMed Central

Clarke, David J.; Chaudhuri, Roy R.; Martin, Helen M.; Campbell, Barry J.; Rhodes, Jonathan M.; Constantinidou, Chrystala; Pallen, Mark J.; Loman, Nicholas J.; Cunningham, Adam F.; Browning, Douglas F.; Henderson, Ian R.

2011-01-01

Adherent-invasive Escherichia colistrains are increasingly being associated with intestinal pathologies. Here we present the genome sequence of E. coliHM605, a strain isolated from colonic biopsy specimens of a patient with Crohn's disease. PMID:21705601

Genotypic and epidemiologic characterization of extended-spectrum cephalosporin resistant Salmonella enterica from US beef feedlots.

PubMed

Mollenkopf, D F; Mathys, D A; Dargatz, D A; Erdman, M M; Habing, G G; Daniels, J B; Wittum, T E

2017-10-01

In the US, nontyphoidal Salmonellae are a common foodborne zoonotic pathogen causing gastroenteritis. Invasive Salmonella infections caused by extended-spectrum cephalosporin resistant (ESCR) phenotypes are more likely to result in treatment failure and adverse health outcomes, especially in severe pediatric Salmonella infections where the extended-spectrum β-lactams are the therapy of choice. To examine the genetic and epidemiologic characteristics of ESCR Salmonellae which may enter the food chain, we characterized 44 ceftiofur-resistant Salmonella isolates from the National Animal Health Monitoring System (NAHMS) 2011 beef cattle feedlot health and management study. As part of the NAHMS Feedlot 2011 study, 5050 individual fecal samples from 68 large (1000+ head capacity) feedlots were cultured for Salmonella spp. The resulting 460 positive samples yielded 571 Salmonella isolates with 44 (8%) expressing an AmpC β-lactamase phenotype. These phenotypic bla CMY-2 Salmonella isolates represented 8 serotypes, most commonly S. Newport (n=14, 32%), S. Typhimurium (n=13, 30%), and S. Reading (n=5, 11%), followed by S. Dublin, S. Infantis, S. Montevideo, S. Rough O:i;v:1;7, and S. Uganda. Carriage of the bla CMY-2 gene was confirmed for all isolates expressing an AmpC β-lactamase phenotype by PCR. Additionally, all 44 isolates were shown to carry the bla CMY-2 gene on a large IncA/C plasmid, a gene/plasmid combination which has been previously reported in multiple species. Other plasmids, including IncN, FIC, and FIIA, were also detected in some isolates. Cattle fed chlortetracycline were less likely to be positive for a bla CMY-2 Salmonella isolate in their enteric flora compared to those not receiving chlortetracycline during the feeding period. Carriage of bla CMY-2 was more prevalent in Salmonella isolates originating from lighter weight cattle, cattle fed tylosin and dairy breeds. Our characterization of the NAHMS Feedlot 2011 study Salmonella isolates with ESCR phenotype shows that while other cephalosporin resistance mechanisms have been reported in US cattle, specific serotypes harboring bla CMY-2 on IncA/C plasmids may be the dominant resistance genotype. Copyright © 2017 Elsevier B.V. All rights reserved.

Invasive forest species

Treesearch

Barbara L. Illman

2006-01-01

Nonnative organisms that cause a major change to native ecosystems-once called foreign species, biological invasions, alien invasives, exotics, or biohazards–are now generally referred to as invasive species or invasives. invasive species of insects, fungi, plants, fish, and other organisms present a rising threat to natural forest ecosystems worldwide. Invasive...

Symbiotic flagellate protists as cryptic drivers of adaptation and invasiveness of the subterranean termite Reticulitermes grassei Clément.

PubMed

Duarte, Sónia; Nobre, Tânia; Borges, Paulo A V; Nunes, Lina

2018-06-01

Changes in flagellate protist communities of subterranean termite Reticulitermes grassei across different locations were evaluated following four predictions: (i) Rural endemic (Portugal mainland) termite populations will exhibit high diversity of symbionts; (ii) invasive urban populations (Horta city, Faial island, Azores), on the contrary, will exhibit lower diversity of symbionts, showing high similarity of symbiont assemblages through environmental filtering; (iii) recent historical colonization of isolated regions-as the case of islands-will imply a loss of symbiont diversity; and (iv) island isolation will trigger a change in colony breeding structure toward a less aggressive behavior. Symbiont flagellate protist communities were morphologically identified, and species richness and relative abundances, as well as biodiversity indices, were used to compare symbiotic communities in colonies from urban and rural environments and between island invasive and mainland endemic populations. To evaluate prediction on the impact of isolation (iv), aggression tests were performed among termites comprising island invasive and mainland endemic populations. A core group of flagellates and secondary facultative symbionts was identified. Termites from rural environments showed, in the majority of observed colonies, more diverse and abundant protist communities, probably confirming prediction (i). Corroborating prediction (ii), the two least diverse communities belong to termites captured inside urban areas. The Azorean invasive termite colonies had more diverse protist communities than expected and prediction (iii) which was not verified within this study. Termites from mainland populations showed a high level of aggressiveness between neighboring colonies, in contrast to the invasive colonies from Horta city, which were not aggressive to neighbors according to prediction (iv). The symbiotic flagellate community of R. grassei showed the ability to change in a way that might be consistent with adaptation to available conditions, possibly contributing to optimization of the colonization of new habitats and spreading of its distribution area, highlighting R. grassei potential as an invasive species.

Prevalent emm types and superantigen gene patterns of group A Streptococcus in Thailand.

PubMed

Paveenkittiporn, W; Nozawa, T; Dejsirilert, S; Nakagawa, I; Hamada, S

2016-03-01

Group A Streptococcus (GAS) are globally distributed bacterial pathogens. We examined the emm genotypes, which are important indicators of virulence, of 349 clinical GAS isolates collected using two surveillance systems, i.e. Invasive Bacterial Infection Surveillance (IBIS) from 2010 to 2011 (234 isolates) and routine surveillance of clinically isolated bacteria from various hospitals during 1996-2011 (115 isolates) in Thailand. The major emm genotypes in IBIS samples were emm44 (12·0%), emm104 (6·8%), emm22 (5·6%), and emm81 (5·6%), whereas only one isolate (0·4%) had the emm1 genotype, which is significantly more common in invasive cases in the Western world. In samples collected during routine surveillance, emm238 (10·4%), emm44 (8·7%), and emm165 (7·0%) were dominant. The major superantigen gene profiles were similar between the groups, and 30·1% of isolates did not possess the phage-encoded superantigens (speA, speC, speH, speI, speK, speL, speM, ssa). Although most isolates exhibited limited gene profiles, emm44 isolates had highly variable gene profiles (15 patterns). We conclude that emm44 is the predominant GAS genotype in Thailand, and isolates varied in superantigen gene profiles.

Chronic effects of an invasive species on an animal community.

PubMed

Doody, J Sean; Rhind, David; Green, Brian; Castellano, Christina; McHenry, Colin; Clulow, Simon

2017-08-01

Invasive species can trigger trophic cascades in animal communities, but published cases involving their removal of top predators are extremely rare. An exception is the invasive cane toad (Rhinella marina) in Australia, which has caused severe population declines in monitor lizards, triggering trophic cascades that facilitated dramatic and sometimes unexpected increases in several prey of the predators, including smaller lizards, snakes, turtles, crocodiles, and birds. Persistence of isolated populations of these predators with a decades-long sympatry with toads suggests the possibility of recovery, but alternative explanations are possible. Confirming predator recovery requires longer-term study of populations with both baseline and immediate post-invasion densities. Previously, we quantified short-term impacts of invasive cane toads on animal communities over seven years at two sites in tropical Australia. Herein, we test the hypothesis that predators have begun to recover by repeating the study 12 yr after the initial toad invasion. The three predatory lizards that experienced 71-97% declines in the short-term study showed no sign of recovery, and indeed a worse fate: two of the three species were no longer detectable in 630 km of river surveys, suggesting local extirpation. Two mesopredators that had increased markedly in the short term due to these predator losses showed diverse responses in the medium term; a small lizard species increased by ~500%, while populations of a snake species showed little change. Our results indicate a system still in ecological turmoil, having not yet reached a "new equilibrium" more than a decade after the initial invasion; predator losses due to this toxic invasive species, and thus downstream effects, were not transient. Given that cane toads have proven too prolific to eradicate or control, we suggest that recovery of impacted predators must occur unassisted by evolutionary means: dispersal into extinction sites from surviving populations with alleles for toxin resistance or toad avoidance. Evolution and subsequent dispersal may be the only solution for a number of species or communities affected by invasive species for which control is either prohibitively expensive, or not possible. © 2017 by the Ecological Society of America.

ELK3 promotes the migration and invasion of liver cancer stem cells by targeting HIF-1α.

PubMed

Lee, Joon Ho; Hur, Wonhee; Hong, Sung Woo; Kim, Jung-Hee; Kim, Sung Min; Lee, Eun Byul; Yoon, Seung Kew

2017-02-01

Hepatocellular carcinoma (HCC) is the fifth most common solid cancer and the third most common cause of cancer-related mortality. HCC develops via a multistep process associated with genetic aberrations that facilitate HCC invasion and migration and promote metastasis. A growing body of evidence indicates that cancer stem cells (CSCs) are responsible for tumorigenesis, cancer cell invasion and metastasis. Despite the extremely small proportion of cancer cells represented by this subpopulation of HCC cells, CSCs play a key role in cancer metastasis and poor prognosis. ELK3 (Net/SAP-2/Erp) is a transcription factor that is activated by the Ras/extracellular signal-regulated kinase (ERK) signaling pathway. It plays several important roles in various physiological processes, including cell migration, invasion, wound healing, angiogenesis and tumorigenesis. In the present study, we investigated the role of ELK3 in cancer cell invasion and metastasis in CD133+/CD44+ liver cancer stem cells (LCSCs). We isolated LCSCs expressing CD133 and CD44 from Huh7 HCC cells and evaluated their metastatic potential using invasion and migration assays. We found that CD133+/CD44+ cells had increased metastatic potential compared with non-CD133+/CD44+ cells. We also demonstrated that ELK3 expression was upregulated in CD133+/CD44+ cells and that this aberration enhanced cell migration and invasion. In addition, we identified the molecular mechanism by which ELK3 promotes cancer cell migration and invasion. We found that silencing of ELK3 expression in CD133+/CD44+ LCSCs attenuated their metastatic potential by modulating the expression of heat shock-induced factor-1α (HIF-1α). Collectively, the results of the present study demonstrated that ELK3 overexpression promoted metastasis in CD133+/CD44+ cells by regulating HIF-1α expression and that silencing of ELK3 expression attenuated the metastatic potential of CD133+/CD44+ LCSCs. In conclusion, modulation of ELK3 expression may represent a novel therapeutic strategy for preventing HCC metastasis and invasion.

Characterization of Beauveria bassiana (Ascomycota: Hypocreales) isolates associated with Agrilus planipennis (Coleoptera: Buprestidae) populations in Michigan

Treesearch

Louela A. Castrillo; Leah S. Bauer; Houping Liu; Michael H. Griggs; John D. Vandenberg

2010-01-01

Earlier research in Michigan on fungal entomopathogens of the emerald ash borer (EAB), a major invasive pest of ash trees, resulted in the isolation of Beauveria bassiana from late-instar larvae and pre-pupae. In the present study, some of these isolates were characterized and compared to ash bark- and soil-derived isolates to determine their...

Phase Variation of NadA in Invasive Neisseria meningitidis Isolates Impacts on Coverage Estimates for 4C-MenB, a MenB vaccine.

PubMed

Green, Luke R; Lucidarme, Jay; Dave, Neelam; Chan, Hannah; Clark, Stephen; Borrow, Ray; Bayliss, Christopher D

2018-06-27

A recombinant NadA protein is one of the four major protective antigens of 4C-MenB (Bexsero®), a vaccine developed for serogroup B Neisseria meningitidis (MenB). The Meningococcal Antigen Typing System (MATS) is utilised as a high throughput assay for assessing the invasive MenB strain coverage of 4C-MenB. Where present, the nadA gene is subject to phase variable changes in transcription due to a 5'TAAA repeat tract located in a regulatory region. The promoter-containing intergenic region sequences (IGR) and 5'TAAA repeat numbers were determined for 906 invasive meningococcal disease isolates possessing the nadA gene. Exclusion of the 5'TAAA repeats reduced the number of IGR alleles from 82 to 23. Repeat numbers were associated with low and high levels of NadA expression by Western blotting and ELISA. Low expression repeat numbers were present in 83% of 179 MenB isolates with NadA-2/3 or Nad-1 peptide variants and 68% of 480 MenW ST-11 complex isolates with Nad-2/3 peptide variants. For isolates with vaccine-compatible NadA variants, 93% of MATS negative isolates were associated with low expression repeat numbers whereas 63% of isolates with MATS RP scores above the 95% confidence interval for the positive bactericidal threshold had high expression repeat numbers. Analysis of the 5'TAAA repeat number has potential as a rapid, high throughput method for assessing strain coverage for the NadA-component of 4C-MenB. A key application will be assessing coverage in meningococcal disease cases where confirmation is by PCR only and MATS cannot be applied. Copyright © 2018 Green et al.

Genotypic and Phenotypic Characterization of Carriage and Invasive Disease Isolates of Neisseria meningitidis in Finland

PubMed Central

Saukkoriipi, Annika; Bratcher, Holly B.; Bloigu, Aini; Juvonen, Raija; Silvennoinen-Kassinen, Sylvi; Peitso, Ari; Harju, Terttu; Vainio, Olli; Kuusi, Markku; Maiden, Martin C. J.; Leinonen, Maija; Käyhty, Helena; Toropainen, Maija

2012-01-01

The relationship between carriage and the development of invasive meningococcal disease is not fully understood. We investigated the changes in meningococcal carriage in 892 military recruits in Finland during a nonepidemic period (July 2004 to January 2006) and characterized all of the oropharyngeal meningococcal isolates obtained (n = 215) by using phenotypic (serogrouping and serotyping) and genotypic (porA typing and multilocus sequence typing) methods. For comparison, 84 invasive meningococcal disease strains isolated in Finland between January 2004 and February 2006 were also analyzed. The rate of meningococcal carriage was significantly higher at the end of military service than on arrival (18% versus 2.2%; P < 0.001). Seventy-four percent of serogroupable carriage isolates belonged to serogroup B, and 24% belonged to serogroup Y. Most carriage isolates belonged to the carriage-associated ST-60 clonal complex. However, 21.5% belonged to the hyperinvasive ST-41/44 clonal complex. Isolates belonging to the ST-23 clonal complex were cultured more often from oropharyngeal samples taken during the acute phase of respiratory infection than from samples taken at health examinations at the beginning and end of military service (odds ratio [OR], 6.7; 95% confidence interval [95% CI], 2.7 to 16.4). The ST-32 clonal complex was associated with meningococcal disease (OR, 17.8; 95% CI, 3.8 to 81.2), while the ST-60 clonal complex was associated with carriage (OR, 10.7; 95% CI, 3.3 to 35.2). These findings point to the importance of meningococcal vaccination for military recruits and also to the need for an efficacious vaccine against serogroup B isolates. PMID:22135261

Molecular and cellular characterization of a Salmonella enterica serovar Paratyphi a outbreak strain and the human immune response to infection.

PubMed

Gal-Mor, Ohad; Suez, Jotham; Elhadad, Dana; Porwollik, Steffen; Leshem, Eyal; Valinsky, Lea; McClelland, Michael; Schwartz, Eliezer; Rahav, Galia

2012-02-01

Enteric fever is an invasive life-threatening systemic disease caused by the Salmonella enterica human-adapted serovars Typhi and Paratyphi. Increasing incidence of infections with Salmonella enterica serovar Paratyphi A and the spreading of its antibiotic-resistant derivates pose a significant health concern in some areas of the world. Herein, we describe a molecular and phenotypic characterization of an S. Paratyphi A strain accounted for a recent paratyphoid outbreak in Nepal that affected at least 37 travelers. Pulsed-field gel electrophoresis analysis of the outbreak isolates revealed one genetic clone (pulsotype), confirming a single infecting source. Genetic profiling of the outbreak strain demonstrated the contribution of specific bacteriophages as a prime source of genetic diversity among clinical isolates of S. Paratyphi A. Phenotypic characterization in comparison with the S. Paratyphi A ATCC 9150 reference sequenced strain showed differences in flagellar morphology and increased abilities of the outbreak strain with respect to its motility, invasion into nonphagocytic cells, intracellular multiplication, survival within macrophages, and higher induction of interleukin-8 (IL-8) secreted by host cells. Collectively, these differences suggest an enhanced virulence potential of this strain and demonstrate an interesting phenotypic variation among S. Paratyphi A isolates. In vivo profiling of 16 inflammatory cytokines in patients infected with the outbreak strain revealed a common profile of a remarkable gamma interferon (IFN-γ) induction together with elevated concentrations of tumor necrosis factor alpha (TNF-α), IL-6, IL-8, IL-10, and IL-15, but not IL-12, which was previously demonstrated as elevated in nontyphoidal Salmonella infections. This apparent profile implies a distinct immune response to paratyphoid infections.

Activity of Bacillus thuringiensis against Pryeria sinica(Lepidoptera: Zygaenidae), an invasive pest of Euonymus

USDA-ARS?s Scientific Manuscript database

Pryeria sinica Moore (Lepidoptera: Zygaenidae), an invasive pest of Euonymus, is susceptible in the second instar to the Bacillus thuringiensis Berliner product Thuricide®, and to several strains isolated from other B. thuringiensis products. Third instars are also susceptible, while susceptibility...

Methodology optimization and diversification for the investigation of virulence potential in Haemophilus influenzae clinical strains.

PubMed

Giucă, Mihaela Cristina; Străuţ, Monica; Surdeanu, Maria; Nica, Maria; Ungureanu, Vasilica; Mihăescu, Grigore

2011-01-01

Ten Haemophilus influenzae strains were isolated from patients aged between 1.6 - 24 years, with various diagnoses (acute meningitis, acute upper respiratory infection, otitis media and acute sinusitis). Identification was based on phenotypic and molecular characteristics; antibiotic susceptibility testing was performed by diffusion method according to CLSI standards 2011 for seven antibiotics. The results of molecular testing showed that all the studied strains produced an amplicon of 1000 bp with ompP2 primers indicating that all strains were H. influenzae. For six strains, the PCR amplicon obtained with bexA specific primers, proving that the strains were capsulated. The results of phenotypic testing showed that four strains were ampicillin nonsusceptible and (beta-lactamase-positive. The virulence potential of H. influenzae clinical strains was investigated by phenotypic methods, including the assessment of the soluble virulence factors on specific media containing the biochemical substratum for the investigated enzymatic factor, as well as the adherence and invasion capacity to HeLa cells monolayer using Cravioto modified method. The studied strains exhibited mainly a diffuse adherence pattern and different adherence indexes. Interestingly, two strains isolated from the same pacient (blood and CSF) showed a different degree of invasiveness, the strain isolated from blood being 20 times more invasive than the one isolated from CSF.

Non-invasive Optical Molecular Imaging for Cancer Detection

NASA Astrophysics Data System (ADS)

Luo, Zhen

Cancer is a leading cause of death worldwide. It remains the second most common cause of death in the US, accounting for nearly 1 out of every 4 deaths. Improved fundamental understanding of molecular processes and pathways resulting in cancer development has catalyzed a shift towards molecular analysis of cancer using imaging technologies. It is expected that the non-invasive or minimally invasive molecular imaging analysis of cancer can significantly aid in improving the early detection of cancer and will result in reduced mortality and morbidity associated with the disease. The central hypothesis of the proposed research is that non-invasive imaging of changes in metabolic activity of individual cells, and extracellular pH within a tissue will improve early stage detection of cancer. The specific goals of this research project were to: (a) develop novel optical imaging probes to image changes in choline metabolism and tissue pH as a function of progression of cancer using clinically isolated tissue biopsies; (b) correlate changes in tissue extracellular pH and metabolic activity of tissues as a function of disease state using clinically isolated tissue biopsies; (c) provide fundamental understanding of relationship between tumor hypoxia, acidification of the extracellular space and altered cellular metabolism with progression of cancer. Three novel molecular imaging probes were developed to detect changes in choline and glucose metabolism and extracellular pH in model systems and clinically isolated cells and biopsies. Glucose uptake and metabolism was measured using a fluorescence analog of glucose, 2-NBDG (2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-D-glucose), while choline metabolism was measured using a click chemistry analog of choline, propargyl choline, which can be in-situ labeled with a fluorophore Alexa-488 azide via a click chemistry reaction. Extracellular pH in tissue were measured by Alexa-647 labeled pHLIP (pH low insertion peptide), which can selectively target plasma membrane of cells based on lower extracellular pH. 20 pairs of clinically normal and abnormal biopsies were obtained from consenting patients at UCDMC. Fluorescence intensity of tissue biopsies before and after topical delivery of 2-NBDG and Alexa-647 labeled pHLIP was measured non-invasively by widefield imaging and confocal microscope. Uptake of propargyl choline was measured after topical delivery using confocal microscope. The results of all three molecular imagine probes were further correlated with pathological diagnosis. The imaging results of clinical biopsies demonstrated that 2-NBDG, propargyl choline and pHLIP peptide can accurately distinguish the pathologically normal and abnormal biopsies. Topical application of the contrast agents generated significantly higher fluorescence signal intensity in all neoplastic tissues as compared to clinically normal biopsies irrespective of the anatomic location or patient. This unpaired comparison across all the cancer patients in this study highlights the specificity of the imaging approach. Furthermore, the results indicated that changes in intracellular glucose, choline metabolism and cancer acidosis are initiated in the early stages of cancer and these changes are correlated with the progression of the disease. In conclusion, these novel optical molecular imaging approaches to measure multiple biomarkers in cancer have significant potential to be a useful tool for improving early detection and prognostic evaluation of oral neoplasia.

Listeria monocytogenes Isolates Carrying Virulence-Attenuating Mutations in Internalin A Are Commonly Isolated from Ready-to-Eat Food Processing Plant and Retail Environments.

PubMed

VAN Stelten, A; Roberts, A R; Manuel, C S; Nightingale, K K

2016-10-01

Listeria monocytogenes is a human foodborne pathogen that may cause an invasive disease known as listeriosis in susceptible individuals. Internalin A (InlA; encoded by inlA) is a virulence factor that facilitates crossing of host cell barriers by L. monocytogenes . At least 19 single nucleotide polymorphisms (SNPs) in inlA that result in a premature stop codon (PMSC) have been described worldwide. SNPs leading to a PMSC in inlA have been shown to be causally associated with attenuated virulence. L. monocytogenes pathogens carrying virulence-attenuating (VA) mutations in inlA have been commonly isolated from ready-to-eat (RTE) foods but rarely have been associated with human disease. This study was conducted to determine the prevalence of VA SNPs in inlA among L. monocytogenes from environments associated with RTE food production and handling. More than 700 L. monocytogenes isolates from RTE food processing plant (n = 409) and retail (n = 319) environments were screened for the presence of VA SNPs in inlA. Overall, 26.4% of isolates from RTE food processing plant and 32.6% of isolates from retail environments carried a VA mutation in inlA. Food contact surfaces sampled at retail establishments were significantly (P < 0.0001) more likely to be contaminated by a L. monocytogenes isolate carrying a VA mutation in inlA (56% of 55 isolates) compared with nonfood contact surfaces (28% of 264 isolates). Overall, a significant proportion of L. monocytogenes isolated from RTE food production and handling environments have reduced virulence. These data will be useful in the revision of current and the development of future risk assessments that incorporate strain-specific virulence parameters.

Potential virulence and antimicrobial susceptibility of Campylobacter jejuni isolates from food and companion animals.

PubMed

Lee, Michelle K; Billington, Stephen J; Joens, Lynn A

2004-01-01

Infection in humans with Campylobacter jejuni is commonly associated with exposure to food animal fecal material. In this study, we report on the recovery, potential for virulence and antimicrobial resistance levels of C. jejuni isolated from food and companion animals. Three hundred and seventy-eight fecal samples from food and companion animals and surface swabs from beef carcasses were tested for the presence of C. jejuni. C. jejuni was isolated from 13.8% (11/80) of dogs, 5% (1/20) of goats, 28.3% (17/60) of dairy cattle, 0% (0/65) of range cattle, 73.5% (36/49) of feedlot cattle, and 94.7% (18/19) of beef carcasses. Beef cattle from a single Arizona herd showed a considerable increase in fecal shedding of C. jejuni from pasture to feedlot and over time on the feedlot. Forty-two isolates were tested for susceptibility to four antimicrobial agents, each representing a class of antimicrobial drug approved for use in both humans and animals. None of the isolates were found to be resistant to erythromycin or gentamicin, whereas 2.4% of isolates were resistant to ciprofloxacin and 28.6% of isolates were resistant to tetracycline. The presence of virulence traits among the 42 isolates was assessed using in vitro macrophage survival and epithelial cell adherence and invasion assays. Of the isolates examined, 17 were able to survive within macrophages through 72 h at viable counts of >/=10(3)/well and 12 were capable of invading epithelial cells at viable counts of >/=10(3)/well. Data from these studies suggests that many of the isolates recovered from the non-poultry animal sources have the capacity to cause disease if transmitted to humans.

Introduced species: A significant component of human-caused global change

USGS Publications Warehouse

Vitousek, Peter M.; D'Antonio, Carla M.; Loope, Lloyd L.; Rejmanek, Marcel; Westbrooks, Randy G.

1997-01-01

Biological invasions are a widespread and significant component of human-caused global environmental change. The extent of invasions of oceanic islands, and their consequences for native biological diversity, have long been recognized. However, invasions of continental regions also are substantial. For example, more than 2,000 species of alien plants are established in the continental United States. These invasions represent a human-caused breakdown of the regional distinctiveness of Earth's flora and fauna—a substantial global change in and of itself. Moreover, there are well- documented examples of invading species that degrade human health and wealth, alter the structure and functioning of otherwise undisturbed ecosystems, and/or threaten native biological diversity. Invasions also interact synergistically with other components of global change. notably land use change. People and institutions working to understand, prevent, and control invasions are carrying out some of the most important—and potentially most effective—work on global environmental change.

Pediatric invasive disease due to Haemophilus influenzae serogroup A in Riyadh, Saudi Arabia: case series.

PubMed

Roaa, Zailaie; Abdulsalam, Alawfi; Shahid, Ghazi; Kamaldeen, Baba; Tariq, Al Fawaz

2016-05-31

We describe the first two cases of invasive disease caused by Haemophilus influenzae serotype A in Saudi Arabia. This is the first known reported invasive Haemophilus influenzae serotype A from Saudi Arabia. A ten-month-old and three-month-old male not known to have any past history of any medical illness and who had received H. influenzae type b (Hib) vaccine presented to our hospital mainly with fever of few days' duration. A provisional diagnosis of meningitis with sepsis was made and laboratory tests were requested. The chest radiograph was normal. The laboratory results revealed leukocytosis, but leukopenia was noticed in the younger infant. Blood culture and cerebrospinal fluid specimens yielded a pure culture of Haemophilus influenzae and serotyping showed the isolates to be serogroup A. Both patients were started on vancomycin and third-generation cephalosporin. On receiving the blood culture result, vancomycin was stopped. Fever subsided after 48 hours, while in the second case, it continued for 12 days from the admission date. The repeat blood cultures were negative. Antibiotic therapy was given for 10 days for the first case with an unremarkable hospital course, while the second case was complicated by seizure and received a longer duration of antibiotics. Both infants were discharged home in good condition. Invasive non-typeable H. influenzae strains are emerging and there is a need for surveillance of this disease. This has implications in future vaccine development.

Gymnemic Acids Inhibit Hyphal Growth and Virulence in Candida albicans

PubMed Central

Vediyappan, Govindsamy; Dumontet, Vincent; Pelissier, Franck; d’Enfert, Christophe

2013-01-01

Candida albicans is an opportunistic and polymorphic fungal pathogen that causes mucosal, disseminated and invasive infections in humans. Transition from the yeast form to the hyphal form is one of the key virulence factors in C. albicans contributing to macrophage evasion, tissue invasion and biofilm formation. Nontoxic small molecules that inhibit C. albicans yeast-to-hypha conversion and hyphal growth could represent a valuable source for understanding pathogenic fungal morphogenesis, identifying drug targets and serving as templates for the development of novel antifungal agents. Here, we have identified the triterpenoid saponin family of gymnemic acids (GAs) as inhibitor of C. albicans morphogenesis. GAs were isolated and purified from Gymnema sylvestre leaves, the Ayurvedic traditional medicinal plant used to treat diabetes. Purified GAs had no effect on the growth and viability of C. albicans yeast cells but inhibited its yeast-to-hypha conversion under several hypha-inducing conditions, including the presence of serum. Moreover, GAs promoted the conversion of C. albicans hyphae into yeast cells under hypha inducing conditions. They also inhibited conidial germination and hyphal growth of Aspergillus sp. Finally, GAs inhibited the formation of invasive hyphae from C. albicans-infected Caenorhabditis elegans worms and rescued them from killing by C. albicans. Hence, GAs could be useful for various antifungal applications due to their traditional use in herbal medicine. PMID:24040201

Molecular Identification, Antifungal Susceptibility Profile, and Biofilm Formation of Clinical and Environmental Rhodotorula Species Isolates

PubMed Central

Nunes, Jorge Meneses; Bizerra, Fernando César; Ferreira, Renata Carmona e

2013-01-01

Rhodotorula species are emergent fungal pathogens capable of causing invasive infections, primarily fungemia. They are particularly problematic in immunosuppressed patients when using a central venous catheter. In this study, we evaluated the species distribution of 51 clinical and 8 environmental Rhodotorula species isolates using the ID32C system and internal transcribed spacer (ITS) sequencing. Antifungal susceptibility testing and biofilm formation capability using a crystal violet staining assay were performed. Using ITS sequencing as the gold standard, the clinical isolates were identified as follows: 44 R. mucilaginosa isolates, 2 R. glutinis isolates, 2 R. minuta isolates, 2 R. dairenensis isolates, and 1 Rhodosporidium fluviale isolate. The environmental isolates included 7 R. mucilaginosa isolates and 1 R. slooffiae isolate. Using the ID32C system, along with a nitrate assimilation test, only 90.3% of the isolates tested were correctly identified. In the biofilm formation assay, R. mucilaginosa and R. minuta exhibited greater biofilm formation ability compared to the other Rhodotorula species; the clinical isolates of R. mucilaginosa showed greater biofilm formation compared to the environmental isolates (P = 0.04). Amphotericin B showed good in vitro activity (MIC ≤ 1 μg/ml) against planktonic cells, whereas voriconazole and posaconazole showed poor activity (MIC50/MIC90, 2/4 μg/ml). Caspofungin and fluconazole MICs were consistently high for all isolates tested (≥64 μg/ml and ≥ 4 μg/ml, respectively). In this study, we emphasized the importance of molecular methods to correctly identify Rhodotorula species isolates and non-R. mucilaginosa species in particular. The antifungal susceptibility profile reinforces amphotericin B as the antifungal drug of choice for the treatment of Rhodotorula infections. To our knowledge, this is the first study evaluating putative differences in the ability of biofilm formation among different Rhodotorula species. PMID:23114761

Molecular identification, antifungal susceptibility profile, and biofilm formation of clinical and environmental Rhodotorula species isolates.

PubMed

Nunes, Jorge Meneses; Bizerra, Fernando César; Ferreira, Renata Carmona E; Colombo, Arnaldo Lopes

2013-01-01

Rhodotorula species are emergent fungal pathogens capable of causing invasive infections, primarily fungemia. They are particularly problematic in immunosuppressed patients when using a central venous catheter. In this study, we evaluated the species distribution of 51 clinical and 8 environmental Rhodotorula species isolates using the ID32C system and internal transcribed spacer (ITS) sequencing. Antifungal susceptibility testing and biofilm formation capability using a crystal violet staining assay were performed. Using ITS sequencing as the gold standard, the clinical isolates were identified as follows: 44 R. mucilaginosa isolates, 2 R. glutinis isolates, 2 R. minuta isolates, 2 R. dairenensis isolates, and 1 Rhodosporidium fluviale isolate. The environmental isolates included 7 R. mucilaginosa isolates and 1 R. slooffiae isolate. Using the ID32C system, along with a nitrate assimilation test, only 90.3% of the isolates tested were correctly identified. In the biofilm formation assay, R. mucilaginosa and R. minuta exhibited greater biofilm formation ability compared to the other Rhodotorula species; the clinical isolates of R. mucilaginosa showed greater biofilm formation compared to the environmental isolates (P = 0.04). Amphotericin B showed good in vitro activity (MIC ≤ 1 μg/ml) against planktonic cells, whereas voriconazole and posaconazole showed poor activity (MIC(50)/MIC(90), 2/4 μg/ml). Caspofungin and fluconazole MICs were consistently high for all isolates tested (≥64 μg/ml and ≥ 4 μg/ml, respectively). In this study, we emphasized the importance of molecular methods to correctly identify Rhodotorula species isolates and non-R. mucilaginosa species in particular. The antifungal susceptibility profile reinforces amphotericin B as the antifungal drug of choice for the treatment of Rhodotorula infections. To our knowledge, this is the first study evaluating putative differences in the ability of biofilm formation among different Rhodotorula species.

Phylogenetic analysis reveals two genotypes of the emerging fungus Mucor indicus, an opportunistic human pathogen in immunocompromised patients.

PubMed

Taj-Aldeen, Saad J; Almaslamani, Muna; Theelen, Bart; Boekhout, Teun

2017-07-12

Mucormycosis is a rare fungal infection caused by Mucor indicus. Phylogenetic analysis of many M. indicus isolates, mainly sampled from different clinical and environmental specimens collected worldwide, revealed two genotypes, I and II, based on ITS and D1/D2 LSU rDNA sequences. A retrospective review of the literature revealed 13 cases. Eight (76.9%) patients had disseminated infections, and the overall mortality rate was 30.7%. A pulmonary infection caused by M. indicus genotype I in a liver transplant recipient was disseminated to include the skin and was successfully treated with liposomal amphotericin B and aggressive surgery. M. indicus can infect a wide variety of patients with no real preference for the site of infection. We concluded that M. indicus has emerged as a significant cause of invasive mycosis in severely immunocompromised patients worldwide. Early diagnosis and initiation of appropriate therapy could enhance survival in these immunocompromised patient populations.

Assessing the cost of an invasive forest pathogen; A case study with oak wilt

Treesearch

Robert G. Haight; Frances R. Homans; Tetsuya Horie; Shefali V. Mehta; David J. Smith; Robert C. Venette

2011-01-01

Economic assessment of damage caused by invasive alien species provides useful information to consider when determining whether management programs should be established, modified, or discontinued. We estimate the baseline economic damage from an invasive alien pathogen, Ceratocystis fagacearum, a fungus that causes oak wilt, which is a significant...

Occurrence of pathogenicity island I(APEC-O1) genes among Escherichia coli implicated in avian colibacillosis.

PubMed

Kariyawasam, Subhashinie; Johnson, Timothy J; Debroy, Chitrita; Nolan, Lisa K

2006-09-01

Colibacillosis caused by avian pathogenic Escherichia coli (APEC) is a leading cause of economic loss to the poultry industry worldwide. The ability of APEC to cause disease is determined by certain virulence markers, some of which are located on pathogenicity islands (PAls). We recently described one such PAI in an APEC O1:K1 strain (APEC-O1). This PAI, termed PAI I(APEC-O1), carries the genes of the pap operon, a region similar to the tia invasion determinant of enterotoxigenic E coli; ireA, a gene that encodes an iron-responsive element; and a novel 1.5-kb region, ORF 54. Here, the occurrence of six selected loci of PAI I(APEC-O1) (papA, papC, papG, ireA, tia, and ORF 54) among APEC and fecal E. coli strains from apparently healthy chickens (avian commensal E. coli) was determined using polymerase chain reaction (PCR) techniques. None of the commensal E. coli was positive for all six traits, whereas 7.2% of the APEC isolates were positive for all the traits. Although there was no significant difference in the occurrence of ORF 54 among APEC and commensal E. coli, tia, ireA, papC, and papG genes were predominantly present in APEC rather than in avian commensal E. coli. papA was detected in only 6.3% of APEC, perhaps because of the presence of allelic variants of the gene. Additionally, the presence of all six traits was tested with PCR in APEC isolates collected in the 1980s, and these results were compared with those obtained with the APEC isolated in the 1990s. There was no significant difference in the occurrence of tia, ireA, papC, papG, and ORF 54 between APEC isolates collected during the different decades. However, papA was more frequently present in APEC from the 1980s than it was in APEC from the 1990s. Phylogenetic group of an isolate did not correlate with pathogenicity or the presence of PAI traits, except that more APEC of the low-pathogenicity group belonged to the phylogenetic group B1. However, PAI traits occurred more frequently in isolates belonging to the intermediate- and high-pathogenicity groups than in isolates of low pathogenicity.

Growth inhibition and ultrastructural alterations induced by Delta24(25)-sterol methyltransferase inhibitors in Candida spp. isolates, including non-albicans organisms.

PubMed

Ishida, Kelly; Rodrigues, Juliany Cola Fernandes; Ribeiro, Marcos Dornelas; Vila, Taíssa Vieira Machado; de Souza, Wanderley; Urbina, Julio A; Nakamura, Celso Vataru; Rozental, Sonia

2009-04-20

Although Candida species are commensal microorganisms, they can cause many invasive fungal infections. In addition, antifungal resistance can contribute to failure of treatment.The purpose of this study was to evaluate the antifungal activity of inhibitors of Delta24(25)-sterol methyltransferase (24-SMTI), 20-piperidin-2-yl-5alpha-pregnan-3beta-20(R)-diol (AZA), and 24(R,S),25-epiminolanosterol (EIL), against clinical isolates of Candida spp., analysing the ultrastructural changes. AZA and EIL were found to be potent growth inhibitors of Candida spp. isolates. The median MIC50 was 0.5 microg.ml-1 for AZA and 2 microg.ml-1 for EIL, and the MIC90 was 2 microg.ml-1 for both compounds. All strains used in this study were susceptible to amphotericin B; however, some isolates were fluconazole- and itraconazole-resistant. Most of the azole-resistant isolates were Candida non-albicans (CNA) species, but several of them, such as C. guilliermondii, C. zeylanoides, and C. lipolytica, were susceptible to 24-SMTI, indicating a lack of cross-resistance. Reference strain C. krusei (ATCC 6258, FLC-resistant) was consistently susceptible to AZA, although not to EIL. The fungicidal activity of 24-SMTI was particularly high against CNA isolates. Treatment with sub-inhibitory concentrations of AZA and EIL induced several ultrastructural alterations, including changes in the cell-wall shape and thickness, a pronounced disconnection between the cell wall and cytoplasm with an electron-lucent zone between them, mitochondrial swelling, and the presence of electron-dense vacuoles. Fluorescence microscopy analyses indicated an accumulation of lipid bodies and alterations in the cell cycle of the yeasts. The selectivity of 24-SMTI for fungal cells versus mammalian cells was assessed by the sulforhodamine B viability assay. Taken together, these results suggest that inhibition of 24-SMT may be a novel approach to control Candida spp. infections, including those caused by azole-resistant strains.

Growth inhibition and ultrastructural alterations induced by Δ24(25)-sterol methyltransferase inhibitors in Candida spp. isolates, including non-albicans organisms

PubMed Central

2009-01-01

Background Although Candida species are commensal microorganisms, they can cause many invasive fungal infections. In addition, antifungal resistance can contribute to failure of treatment. The purpose of this study was to evaluate the antifungal activity of inhibitors of Δ24(25)-sterol methyltransferase (24-SMTI), 20-piperidin-2-yl-5α-pregnan-3β-20(R)-diol (AZA), and 24(R,S),25-epiminolanosterol (EIL), against clinical isolates of Candida spp., analysing the ultrastructural changes. Results AZA and EIL were found to be potent growth inhibitors of Candida spp. isolates. The median MIC50 was 0.5 μg.ml-1 for AZA and 2 μg.ml-1 for EIL, and the MIC90 was 2 μg.ml-1 for both compounds. All strains used in this study were susceptible to amphotericin B; however, some isolates were fluconazole- and itraconazole-resistant. Most of the azole-resistant isolates were Candida non-albicans (CNA) species, but several of them, such as C. guilliermondii, C. zeylanoides, and C. lipolytica, were susceptible to 24-SMTI, indicating a lack of cross-resistance. Reference strain C. krusei (ATCC 6258, FLC-resistant) was consistently susceptible to AZA, although not to EIL. The fungicidal activity of 24-SMTI was particularly high against CNA isolates. Treatment with sub-inhibitory concentrations of AZA and EIL induced several ultrastructural alterations, including changes in the cell-wall shape and thickness, a pronounced disconnection between the cell wall and cytoplasm with an electron-lucent zone between them, mitochondrial swelling, and the presence of electron-dense vacuoles. Fluorescence microscopy analyses indicated an accumulation of lipid bodies and alterations in the cell cycle of the yeasts. The selectivity of 24-SMTI for fungal cells versus mammalian cells was assessed by the sulforhodamine B viability assay. Conclusion Taken together, these results suggest that inhibition of 24-SMT may be a novel approach to control Candida spp. infections, including those caused by azole-resistant strains. PMID:19379501

Outbreak of invasive listeriosis associated with the consumption of hog head cheese, Louisiana, 2010

USDA-ARS?s Scientific Manuscript database

A cluster of eight cases of laboratory-confirmed invasive listeriosis was reported to the Louisiana Office of Public Health (OPH) between February and June of 2010. All eight clinical isolates were Listeria monocytogenes, serotype 1/2a and had indistinguishable pulsed-field gel electrophoresis (PFGE...

The importance of education in managing invasive plant species

USDA-ARS?s Scientific Manuscript database

Invasive plant species can establish in diverse environments and with the increase in human mobility, they are no longer restricted to isolated pockets in remote parts of the world. Cheat grass (Bromus tectorum L.) in rangelands, purple loosestrife (Lythrum salicaria L.) in wet lands and Canada this...

Virulence and the presence of aminoglycoside resistance genes of Staphylococcus haemolyticus strains isolated from clinical specimens.

PubMed

Krzymińska, Sylwia; Szczuka, Ewa; Dudzińska, Kinga; Kaznowski, Adam

2015-04-01

We examined thirty methicillin-resistant Staphylococcus haemolyticus isolates cultured from clinical specimens for antibiotic resistance, various important interactions of the bacteria with epithelial cells and putative virulence determinants. All strains were resistant to oxacillin and carried the mecA gene. Aminocyclitol-3'-phosphotransferase (aph(3')-IIIa) gene encoding nucleotidyltransferases was detected in 43 %, aminocyclitol-6'-acetyltransferase-aminocyclitol-2″-phosphotransferase (aac(6')/aph(2″)) gene encoding bifunctional acetyltransferases/phosphotransferases in 33 %, aminocyclitol-4'-adenylyltransferase (ant(4')-Ia) gene encoding phosphotransferases in 20 %. The coexistence of resistance to methicillin and aminoglycosides was investigated in multi-resistant strains. Coexisting (aac(6')/aph(2″)) and (aph(3')-IIIa) genes were detected in 33 % of isolates, whereas 63 % of isolates had at least one of these genes. All strains revealed adherence ability and most of them (63 %) were invasive to epithelial cells. Electron microscopy revealed that the bacteria were found in vacuoles inside the cells. We observed that the contact of the bacteria with host epithelial cells is a prerequisite to their cytotoxicity at 5 h-incubation. Culture supernatant of the strains induced a low effect of cytotoxicity at the same time of incubation. Cell-free supernatant of all isolates expressed cytotoxic activity which caused destruction of HEp-2 cells at 24 h. None of the strains was cytotonic towards CHO cells. Among thirty strains, 27 % revealed lipolytic activity, 43 % produced lecithinase and 20 % were positive for proteinase activity. Analyses of cellular morphology and DNA fragmentation exhibited typical characteristic features of those undergoing apoptosis. The Pearson linear test revealed positive correlations between the apoptotic index at 24 h and percentage of cytotoxicity. Our results provided new insights into the mechanisms contributing to the development of S. haemolyticus-associated infections. The bacteria adhered and invaded to non-professional phagocytes. The invasion of epithelial cells by S. haemolyticus could be similar to phagocytosis that requires polymerization of the actin cytoskeleton. The process is inhibited by cytochalasin D. Moreover, they survived within the cells by residing in membrane bound compartments and induced apoptotic cell death.

Characteristics of invasive Acinetobacter species isolates recovered in a pediatric academic center.

PubMed

Jain, Avish L; Harding, Christian M; Assani, Kaivon; Shrestha, Chandra L; Haga, Mercedees; Leber, Amy; Munson, Robert S; Kopp, Benjamin T

2016-07-22

Acinetobacter species are associated with increasing mortality due to emerging drug-resistance. Pediatric Acinetobacter infections are largely undefined in developed countries and clinical laboratory identification methods do not reliably differentiate between members of the Acinetobacter calcoaceticus-baumannii complex, leading to improper identification. Therefore we aimed to determine risk factors for invasive Acinetobacter infections within an academic, pediatric setting as well as defining microbiologic characteristics of predominant strains. Twenty-four invasive Acinetobacter isolates were collected from 2009-2013. Comparative sequence analysis of the rpoB gene was performed coupled with phenotypic characterization of antibiotic resistance, motility, biofilm production and clinical correlation. Affected patients had a median age of 3.5 years, and 71 % had a central catheter infection source. rpoB gene sequencing revealed a predominance of A. pittii (45.8 %) and A. baumannii (33.3 %) strains. There was increasing incidence of A. pittii over the study. Two fatalities occurred in the A. pittii group. Seventeen percent of isolates were multi-drug resistant. A pittii and A. baumannii strains were similar in motility, but A pittii strains had significantly more biofilm production (P value = 0.018). A. pittii was the most isolated species highlighting the need for proper species identification. The isolated strains had limited acute mortality in children, but the occurrence of more multi-drug resistant strains in the future is a distinct possibility, justifying continued research and accurate species identification.

Fluoroquinolone resistance in Streptococcus pneumoniae isolates in Germany from 2004-2005 to 2014-2015.

PubMed

Schmitz, Julia; van der Linden, Mark; Al-Lahham, Adnan; Levina, Natalia; Pletz, Mathias W; Imöhl, Matthias

2017-06-01

Streptococcus pneumoniae is a major cause of bacterial pneumonia, sepsis and meningitis worldwide. Prevalence of levofloxacin-resistant S. pneumoniae isolates in Germany and associated mutations in the quinolone resistance determining regions (QRDRs), as well as serotype distribution and multi locus sequence types (MLST) are shown. 21,764 invasive S. pneumoniae isolates from Germany, isolated in the epidemiological seasons from 2004/05 to 2014/15 were analyzed at the German National Reference Centre for Streptococci (GNRCS) for their levofloxacin resistance by micro broth dilution method. All resistant (minimal inhibitory concentration (MIC) ≥8μg/ml) and intermediate (MIC >2μg/ml and <8μg/ml) isolates were selected for the present study. Additionally, 29 susceptible isolates were randomly selected. A total of ninety isolates were tested for their levofloxacin-MIC by Etest, their serotype and sequence type, as well as for point-mutations at the QRDRs in the genes parC, parE, gyrA and gyrB. Twenty-five isolates exhibited levofloxacin MICs <2μg/ml (Etest) and no mutations in the QRDRs. Four isolates with MICs=2μg/ml had one mutation in parC; isolates with MICs >2μg/ml all had one or more mutations in the QRDRs. Four of nine intermediate isolates had a mutation in either parC or gyrA, and four isolates had mutations in both parC and gyrB. One isolate had mutations in both parC and gyrA. All isolates with MICs ≥8μg/ml (52) had mutations in both topoisomerase IV and gyrase. Serotypes associated with levofloxacin resistance shifted from a majority of PCV13 serotypes before the introduction of the PCV13 vaccine towards non-PCV serotypes. Resistant isolates were almost exclusively found among adults (98.1%). Copyright © 2017. Published by Elsevier GmbH.

Phylogeography and population structure of the biologically invasive phytopathogen Erwinia amylovora inferred using minisatellites.

PubMed

Bühlmann, Andreas; Dreo, Tanja; Rezzonico, Fabio; Pothier, Joël F; Smits, Theo H M; Ravnikar, Maja; Frey, Jürg E; Duffy, Brion

2014-07-01

Erwinia amylovora causes a major disease of pome fruit trees worldwide, and is regulated as a quarantine organism in many countries. While some diversity of isolates has been observed, molecular epidemiology of this bacterium is hindered by a lack of simple molecular typing techniques with sufficiently high resolution. We report a molecular typing system of E. amylovora based on variable number of tandem repeats (VNTR) analysis. Repeats in the E. amylovora genome were identified with comparative genomic tools, and VNTR markers were developed and validated. A Multiple-Locus VNTR Analysis (MLVA) was applied to E. amylovora isolates from bacterial collections representing global and regional distribution of the pathogen. Based on six repeats, MLVA allowed the distinction of 227 haplotypes among a collection of 833 isolates of worldwide origin. Three geographically separated groups were recognized among global isolates using Bayesian clustering methods. Analysis of regional outbreaks confirmed presence of diverse haplotypes but also high representation of certain haplotypes during outbreaks. MLVA analysis is a practical method for epidemiological studies of E. amylovora, identifying previously unresolved population structure within outbreaks. Knowledge of such structure can increase our understanding on how plant diseases emerge and spread over a given geographical region. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

Western bats as a reservoir of novel Streptomyces species with antifungal activity

USGS Publications Warehouse

Hamm, Paris S.; Caimi, Nicole A.; Northup, Diana E.; Valdez, Ernest W.; Buecher, Debbie C.; Dunlap, Christopher A.; Labeda, David P.; Lueschow, Shiloh; Porras-Alfaro, Andrea

2017-01-01

At least two-thirds of commercial antibiotics today are derived from Actinobacteria, more specifically from the genus Streptomyces. Antibiotic resistance and new emerging diseases pose great challenges in the field of microbiology. Cave systems, in which actinobacteria are ubiquitous and abundant, represent new opportunities for the discovery of novel bacterial species and the study of their interactions with emergent pathogens. White-nose syndrome is an invasive bat disease caused by the fungus Pseudogymnoascus destructans, which has killed more than six million bats in the last 7 years. In this study, we isolated naturally occurring actinobacteria from white-nose syndrome (WNS)-free bats from five cave systems and surface locations in the vicinity in New Mexico and Arizona, USA. We sequenced the 16S rRNA region and tested 632 isolates from 12 different bat species using a bilayer plate method to evaluate antifungal activity. Thirty-six actinobacteria inhibited or stopped the growth of P. destructans, with 32 (88.9%) actinobacteria belonging to the genus Streptomyces. Isolates in the genera Rhodococcus, Streptosporangium, Luteipulveratus, and Nocardiopsis also showed inhibition. Twenty-five of the isolates with antifungal activity against P. destructans represent 15 novel Streptomyces spp. based on multilocus sequence analysis. Our results suggest that bats in western North America caves possess novel bacterial microbiota with the potential to inhibit P. destructans.

Unusual presence of the immune evasion gene cluster in livestock-associated MRSA of lineage CC398 causing peridural and psoas abscesses in a poultry farmer.

PubMed

Pérez-Moreno, Mar Olga; Centelles-Serrano, María José; Nogales-López, Julio; Domenech-Spanedda, Marie France; Lozano, Carmen; Torres, Carmen

2017-12-01

To characterize a methicillin-resistant Staphylococcus aureus (MRSA) isolate responsible for an aggressive infection (peridural and psoas abscess secondary to haematogenous septic arthritis) in a poultry farmer. Molecular characterization was performed, including spa- and multilocus sequence typing of the isolate, assessment of its resistance phenotype and detection of tetracycline resistance and of virulence and immune evasion cluster (IEC) genes were performed. The MRSA isolate was tetracycline- and fluorquinolone-resistant, and was ascribed to CC398, spa-t1451. The isolate harboured tet(M) (distinctive of livestock-associated (LA) MRSA-CC398 clade) and IEC-type B system (characteristic of the methicillin-susceptible human lineage, but typically absent in LA-MRSA-CC398 strains), and lacked toxin-coding genes lukF/lukS-PV, tsst-1, eta and etb. IEC re-acquisition by LA-MRSA-CC398-LA strains is an unusual finding, but could constitute an emerging public health problem. It would represent an evolutionary step towards LA-MRSA-CC398's adaptation to human hosts, and might enhance its invasiveness and ability to be transmitted to humans. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Defining the phylogenomics of Shigella species: a pathway to diagnostics.

PubMed

Sahl, Jason W; Morris, Carolyn R; Emberger, Jennifer; Fraser, Claire M; Ochieng, John Benjamin; Juma, Jane; Fields, Barry; Breiman, Robert F; Gilmour, Matthew; Nataro, James P; Rasko, David A

2015-03-01

Shigellae cause significant diarrheal disease and mortality in humans, as there are approximately 163 million episodes of shigellosis and 1.1 million deaths annually. While significant strides have been made in the understanding of the pathogenesis, few studies on the genomic content of the Shigella species have been completed. The goal of this study was to characterize the genomic diversity of Shigella species through sequencing of 55 isolates representing members of each of the four Shigella species: S. flexneri, S. sonnei, S. boydii, and S. dysenteriae. Phylogeny inferred from 336 available Shigella and Escherichia coli genomes defined exclusive clades of Shigella; conserved genomic markers that can identify each clade were then identified. PCR assays were developed for each clade-specific marker, which was combined with an amplicon for the conserved Shigella invasion antigen, IpaH3, into a multiplex PCR assay. This assay demonstrated high specificity, correctly identifying 218 of 221 presumptive Shigella isolates, and sensitivity, by not identifying any of 151 diverse E. coli isolates incorrectly as Shigella. This new phylogenomics-based PCR assay represents a valuable tool for rapid typing of uncharacterized Shigella isolates and provides a framework that can be utilized for the identification of novel genomic markers from genomic data. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Defining the Phylogenomics of Shigella Species: a Pathway to Diagnostics

PubMed Central

Sahl, Jason W.; Morris, Carolyn R.; Emberger, Jennifer; Fraser, Claire M.; Ochieng, John Benjamin; Juma, Jane; Fields, Barry; Breiman, Robert F.; Gilmour, Matthew; Nataro, James P.

2015-01-01

Shigellae cause significant diarrheal disease and mortality in humans, as there are approximately 163 million episodes of shigellosis and 1.1 million deaths annually. While significant strides have been made in the understanding of the pathogenesis, few studies on the genomic content of the Shigella species have been completed. The goal of this study was to characterize the genomic diversity of Shigella species through sequencing of 55 isolates representing members of each of the four Shigella species: S. flexneri, S. sonnei, S. boydii, and S. dysenteriae. Phylogeny inferred from 336 available Shigella and Escherichia coli genomes defined exclusive clades of Shigella; conserved genomic markers that can identify each clade were then identified. PCR assays were developed for each clade-specific marker, which was combined with an amplicon for the conserved Shigella invasion antigen, IpaH3, into a multiplex PCR assay. This assay demonstrated high specificity, correctly identifying 218 of 221 presumptive Shigella isolates, and sensitivity, by not identifying any of 151 diverse E. coli isolates incorrectly as Shigella. This new phylogenomics-based PCR assay represents a valuable tool for rapid typing of uncharacterized Shigella isolates and provides a framework that can be utilized for the identification of novel genomic markers from genomic data. PMID:25588655

Escherichia coli and Staphylococcus aureus: bad news and good news from the European Antimicrobial Resistance Surveillance Network (EARS-Net, formerly EARSS), 2002 to 2009.

PubMed

Gagliotti, C; Balode, A; Baquero, F; Degener, J; Grundmann, H; Gür, D; Jarlier, V; Kahlmeter, G; Monen, J; Monnet, D L; Rossolini, G M; Suetens, C; Weist, K; Heuer, O

2011-03-17

Based on data collected by the European Antimicrobial Resistance Surveillance Network (EARS-Net) and the former EARSS, the present study describes the trends in antimicrobial susceptibility patterns and occurrence of invasive infections caused by Escherichia coli and Staphylococcus aureus in the period from 2002 to 2009. Antimicrobial susceptibility results from 198 laboratories in 22 European countries reporting continuously on these two microorganisms during the entire study period were included in the analysis. The number of bloodstream infections caused by E. coli increased remarkably by 71% during the study period, while bloodstream infections caused by S. aureus increased by 34%. At the same time, an alarming increase of antimicrobial resistance in E. coli was observed, whereas for S. aureus the proportion of meticillin resistant isolates decreased. The observed trend suggests an increasing burden of disease caused by E. coli. The reduction in the proportion of meticillin-resistant S. aureus and the lesser increase in S. aureus infections, compared with E. coli, may reflect the success of infection control measures at hospital level in several European countries.

Quinolone Resistance Determinants of Clinical Salmonella Enteritidis in Thailand.

PubMed

Utrarachkij, Fuangfa; Nakajima, Chie; Changkwanyeun, Ruchirada; Siripanichgon, Kanokrat; Kongsoi, Siriporn; Pornruangwong, Srirat; Changkaew, Kanjana; Tsunoda, Risa; Tamura, Yutaka; Suthienkul, Orasa; Suzuki, Yasuhiko

2017-10-01

Salmonella Enteritidis has emerged as a global concern regarding quinolone resistance and invasive potential. Although quinolone-resistant S. Enteritidis has been observed with high frequency in Thailand, information on the mechanism of resistance acquisition is limited. To elucidate the mechanism, a total of 158 clinical isolates of nalidixic acid (NAL)-resistant S. Enteritidis were collected throughout Thailand, and the quinolone resistance determinants were investigated in the context of resistance levels to NAL, norfloxacin (NOR), and ciprofloxacin (CIP). The analysis of point mutations in type II topoisomerase genes and the detection of plasmid-mediated quinolone resistance genes showed that all but two harbored a gyrA mutation, the qnrS1 gene, or both. The most commonly affected codon in mutant gyrA was 87, followed by 83. Double codon mutation in gyrA was found in an isolate with high-level resistance to NAL, NOR, and CIP. A new mutation causing serine to isoleucine substitution at codon 83 was identified in eight isolates. In addition to eighteen qnrS1-carrying isolates showing nontypical quinolone resistance, one carrying both the qnrS1 gene and a gyrA mutation also showed a high level of resistance. Genotyping by multilocus variable number of tandem repeat analysis suggested a possible clonal expansion of NAL-resistant strains nationwide. Our data suggested that NAL-resistant isolates with single quinolone resistance determinant may potentially become fluoroquinolone resistant by acquiring secondary determinants. Restricted therapeutic and farming usage of quinolones is strongly recommended to prevent the emergence of fluoroquinolone-resistant isolates.

They're Here: A Coast-to-Coast Investigation of Invasive Species

ERIC Educational Resources Information Center

Hogan, Tracy; Craven, John

2005-01-01

According to the National Invasive Species Council, an "invasive species" is defined as a species that is (1) nonnative (or alien) to the ecosystem under consideration, and (2) whose introduction causes or is likely to cause economic or environmental harm or harm to human health. In this article, the authors describe an activity that can be…

Relevance of spontaneous fabT mutations to a streptococcal toxic shock syndrome to non-streptococcal toxic shock syndrome transition in the novel-type Streptococcus pyogenes isolates that lost a salRK.

PubMed

Tatsuno, Ichiro; Okada, Ryo; Matsumoto, Masakado; Hata, Nanako; Matsui, Hideyuki; Zhang, Yan; Isaka, Masanori; Hasegawa, Tadao

2016-05-01

Streptococcus pyogenes is a causative agent of streptococcal toxic shock syndrome (STSS). Mutations in covR/S or rgg, negative regulators, can reportedly modulate the severity of infection in this pathogen. Recently, we showed that the regions encoding the SalR-SalK, a two-component regulatory system, were deleted in some emm 1-type isolates (named as 'novel-type'). In this study, the two novel 'STSS' isolates 10-85stss and 11-171stss were more virulent than the two novel 'non-STSS' isolates 11O-2non and 11T-3non when examined using a mouse model of invasive infection. Genome-sequencing experiments using the three strains 10-85stss , 11-171stss , and 11O-2non detected only one single nucleotide polymorphism that causes a non-synonymous mutation in fabT encoding a transcriptional regulator in strain 11O-2non . Loss of fabT reduced the high level of virulence observed in the STSS isolates to that in the non-STSS isolates, and introduction of an intact fabT compensated the lower virulence of 11O-2non , suggesting that the mutation in fabT, but not in covR/S or rgg, is involved in the differential virulence among the novel-type clinical isolates. This type of non-synonymous fabT mutation was also identified in 12 non-STSS isolates (including 11O-2non and 11T-3non ), and most of those 12 isolates showed impaired FabT function. © 2016 APMIS. Published by John Wiley & Sons Ltd.

Antimicrobial susceptibility of travel-related Salmonella enterica serovar Typhi isolates detected in Switzerland (2002-2013) and molecular characterization of quinolone resistant isolates.

PubMed

Nüesch-Inderbinen, Magdalena; Abgottspon, Helga; Sägesser, Grethe; Cernela, Nicole; Stephan, Roger

2015-05-12

Typhoid fever is an acute, invasive, and potentially fatal systemic infection caused by Salmonella enterica subspecies enterica serotype Typhi (S. Typhi). Drug resistance to antimicrobials such as ciprofloxacin is emerging in developing countries, threatening the efficacy of treatment of patients in endemic regions as well as of travellers returning from these countries. We compared the antimicrobial resistance profiles of 192 S. Typhi isolated from patients over a time span of twelve years. Susceptibility testing was done by the disk diffusion method. A representative selection of isolates (n = 41) was screened by PCR for mutations in the quinolone resistance-determining regions (QRDRs) of the gyrA and parC genes and all 192 isolates were screened for plasmid-mediated quinolone resistance (PMQR) genes. Multilocus sequence typing (MLST) was used to investigate the sequence type of isolates from patients with a known history of international travel. Resistance rates for nalidixic acid increased from 20 % to 66.7 % between 2002 and 2013. Resistance to ciprofloxacin was detected in 55.6 % of the isolates by 2013. Ciprofloxacin resistance was predominantly associated with the triple substitutions Ser83 → Phe and Asp87 → Asn in GyrA and Ser80 → Ile in ParC. The plasmid-mediated resistance gene qnrS1 was detected in two isolates. Sequence type ST1 was associated with the Indian subcontinent, while ST2 was distributed internationally. Multidrug resistance was noted for 11.5 % of the isolates. Fluoroquinolone resistant S. Typhi constitute a serious public health concern in endemic areas as well as in industrialized countries. Increased surveillance of global patterns of antimicrobial resistance is necessary and the control of resistant strains is of the utmost importance to maintain treatment options.

Activity of a Long-Acting Echinocandin (CD101) and Seven Comparator Antifungal Agents Tested against a Global Collection of Contemporary Invasive Fungal Isolates in the SENTRY 2014 Antifungal Surveillance Program.

PubMed

Pfaller, Michael A; Messer, Shawn A; Rhomberg, Paul R; Castanheira, Mariana

2017-03-01

The activity of CD101 and comparator antifungal agents against 606 invasive fungal isolates collected worldwide during 2014 was evaluated using the Clinical and Laboratory Standards Institute (CLSI) method. All Candida albicans ( n = 251), Candida tropicalis ( n = 51), Candida krusei ( n = 16), and Candida dubliniensis ( n = 11) isolates were inhibited by ≤0.12 μg/ml of CD101 and were susceptible or showed wild-type susceptibility to the other echinocandins tested. Five C. glabrata isolates ( n = 100) displayed CD101 MIC values of 1 to 4 μg/ml, had elevated MICs of caspofungin (2 to >8 μg/ml), anidulafungin (2 to 4 μg/ml), and micafungin (2 to 4 μg/ml), and carried mutations on fks1 and fks2 Candida parapsilosis ( n = 92) and Candida orthopsilosis ( n = 10) displayed higher CD101 MIC values (ranges, 0.5 to 4 μg/ml and 0.12 to 2 μg/ml, respectively), and similar results were observed for the other echinocandins tested. Fluconazole resistance was noted among 11.0% of Candida glabrata isolates, 4.3% of C. parapsilosis isolates, and 2.0% of C. albicans and C. tropicalis isolates. The activity of CD101 against Aspergillus fumigatus ( n = 56) was similar to that of micafungin and 2-fold greater than that of caspofungin but less than that of anidulafungin. These isolates had wild-type susceptibility to itraconazole, voriconazole, and posaconazole. The echinocandins had limited activity against Cryptococcus neoformans ( n = 19). CD101 was as active as the other echinocandins against common fungal organisms recovered from patients with invasive fungal infections. The long half-life profile is very desirable for the prevention and treatment of serious fungal infections, especially in patients who can then be discharged from the hospital to complete antifungal therapy on an outpatient basis. Copyright © 2017 Pfaller et al.

Combination Therapy for Treatment of Infections with Gram-Negative Bacteria

PubMed Central

Cosgrove, Sara E.; Maragakis, Lisa L.

2012-01-01

Summary: Combination antibiotic therapy for invasive infections with Gram-negative bacteria is employed in many health care facilities, especially for certain subgroups of patients, including those with neutropenia, those with infections caused by Pseudomonas aeruginosa, those with ventilator-associated pneumonia, and the severely ill. An argument can be made for empiric combination therapy, as we are witnessing a rise in infections caused by multidrug-resistant Gram-negative organisms. The wisdom of continued combination therapy after an organism is isolated and antimicrobial susceptibility data are known, however, is more controversial. The available evidence suggests that the greatest benefit of combination antibiotic therapy stems from the increased likelihood of choosing an effective agent during empiric therapy, rather than exploitation of in vitro synergy or the prevention of resistance during definitive treatment. In this review, we summarize the available data comparing monotherapy versus combination antimicrobial therapy for the treatment of infections with Gram-negative bacteria. PMID:22763634

Nonnative trout invasions combined with climate change threaten persistence of isolated cutthroat trout populations in the southern Rocky Mountains

USGS Publications Warehouse

Roberts, James J.; Kurt D. Fausch,; Hooten, Mevin B.; Peterson, Douglas P.

2017-01-01

reduce the number of stream fragments that are long enough to buffer CRCT populations against negative genetic consequences and stochastic disturbances by 48, a decrease of 38% compared to CC alone. High priorities are (1) research to estimate how CC and human factors alter the incidence and rate of BT invasions and (2) management to prevent new illegal introductions, repair inadequate barriers, and monitor and address new invasions.

Molecular Characterization of Streptococcus pneumoniae Serotype 12F Isolates Associated with Rural Community Outbreaks in Alaska

PubMed Central

Wenger, Jay D.; Rudolph, Karen; Robinson, D. Ashley; Rakov, Alexey V.; Bruden, Dana; Singleton, Rosalyn J.; Bruce, Michael G.; Hennessy, Thomas W.

2013-01-01

Outbreaks of invasive pneumococcal disease (IPD) caused by Streptococcus pneumoniae serotype 12F were observed in two neighboring regions of rural Alaska in 2003 to 2006 and 2006 to 2008. IPD surveillance data from 1986 to 2009 and carriage survey data from 1998 to 2004 and 2008 to 2009 were reviewed to identify patterns of serotype 12F transmission. Pulsed-field gel electrophoresis was performed on all available isolates, and selected isolates were characterized by additional genetic subtyping methods. Serotype 12F IPD occurred in two waves in Alaska between 1986 and 2008. While cases of disease occurred nearly every year in Anchorage, in rural regions, 12F IPD occurred with rates 10- to 20-fold higher than those in Anchorage, often with many years between disease peaks and generally caused by a single predominant genetic clone. Carriage occurred predominantly in adults, except early in the rural outbreaks, when most carriage was in persons <18 years old. In rural regions, carriage of 12F disappeared completely after outbreaks. Different 12F clones appear to have been introduced episodically into rural populations, spread widely in young, immunologically naïve populations (leading to outbreaks of IPD lasting 1 to 3 years), and then disappeared rapidly from the population. Larger population centers might have been the reservoir for these clones. This epidemiologic pattern is consistent with a highly virulent, but immunogenic, form of pneumococcus. PMID:23408692

Influence of the Host Contact Sequence on the Outcome of Competition among Aspergillus flavus Isolates during Host Tissue Invasion▿

PubMed Central

Mehl, H. L.; Cotty, P. J.

2011-01-01

Biological control of aflatoxin contamination by Aspergillus flavus is achieved through competitive exclusion of aflatoxin producers by atoxigenic strains. Factors dictating the extent to which competitive displacement occurs during host infection are unknown. The role of initial host contact in competition between pairs of A. flavus isolates coinfecting maize kernels was examined. Isolate success during tissue invasion and reproduction was assessed by quantification of isolate-specific single nucleotide polymorphisms using pyrosequencing. Isolates were inoculated either simultaneously or 1 h apart. Increased success during competition was conferred to the first isolate to contact the host independent of that isolate's innate competitive ability. The first-isolate advantage decreased with the conidial concentration, suggesting capture of limited resources on kernel surfaces contributes to competitive exclusion. Attempts to modify access to putative attachment sites by either coating kernels with dead conidia or washing kernels with solvents did not influence the success of the first isolate, suggesting competition for limited attachment sites on kernel surfaces does not mediate first-isolate advantage. The current study is the first to demonstrate an immediate competitive advantage conferred to A. flavus isolates upon host contact and prior to either germ tube emergence or host colonization. This suggests the timing of host contact is as important to competition during disease cycles as innate competitive ability. Early dispersal to susceptible crop components may allow maintenance within A. flavus populations of genetic types with low competitive ability during host tissue invasion. PMID:21216896

Detecting an elusive invasive species: a diagnostic PCR to detect Burmese python in Florida waters and an assessment of persistence of environmental DNA.

PubMed

Piaggio, Antoinette J; Engeman, Richard M; Hopken, Matthew W; Humphrey, John S; Keacher, Kandy L; Bruce, William E; Avery, Michael L

2014-03-01

Recent studies have demonstrated that detection of environmental DNA (eDNA) from aquatic vertebrates in water bodies is possible. The Burmese python, Python bivittatus, is a semi-aquatic, invasive species in Florida where its elusive nature and cryptic coloration make its detection difficult. Our goal was to develop a diagnostic PCR to detect P. bivittatus from water-borne eDNA, which could assist managers in monitoring this invasive species. First, we used captive P. bivittatus to determine whether reptilian DNA could be isolated and amplified from water samples. We also evaluated the efficacy of two DNA isolation methods and two DNA extraction kits commonly used in eDNA preparation. A fragment of the mitochondrial cytochrome b gene from P. bivittatus was detected in all water samples isolated with the sodium acetate precipitate and the QIAamp DNA Micro Kit. Next, we designed P. bivittatus-specific primers and assessed the degradation rate of eDNA in water. Our primers did not amplify DNA from closely related species, and we found that P. bivittatus DNA was consistently detectable up to 96 h. Finally, we sampled water from six field sites in south Florida. Samples from five sites, where P. bivittatus has been observed, tested positive for eDNA. The final site was negative and had no prior documented evidence of P. bivittatus. This study shows P. bivittatus eDNA can be isolated from water samples; thus, this method is a new and promising technique for the management of invasive reptiles. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Multiple criteria-based screening of Trichoderma isolates for biological control of Botrytis cinerea on tomato

USDA-ARS?s Scientific Manuscript database

Seventy-two isolates of Trichoderma were obtained from Hubei Province of China and identified to species based on the ITS-rDNA sequences. The isolates were initially tested for invasive growth on the colonies of Botrytis cinerea in the dual cultures with B. cinerea on potato dextrose agar at 20°C. T...

Evaluation of Candida species and antifungal susceptibilities among children with invasive candidiasis

PubMed Central

Sütçü, Murat; Acar, Manolya; Genç, Gonca Erköse; Kökçü, İlknur; Aktürk, Hacer; Atay, Gürkan; Törun, Selda Hançerli; Salman, Nuran; Erturan, Zayre; Somer, Ayper

2017-01-01

Aim Non-albicans Candida species and resistant microorganisms have been more commonly isolated in invasive candidiasis in recent years. The aim of this study was to evaluate the distrubution of Candida spp and antifungal resistance in our clinic. Material and Methods Fifty-four Candida isolates and antifungal susceptibility results obtained from patients diagnosed as having invasive candidiasis between December 2012 and June 2016 were included. Clinical and laboratory data were retrospectively analyzed. E-test method was used in order to determine antifungal susceptibilities of Candida spp for amphotericin B, fluconazole, voriconazole, ketoconazole, itraconazole, anidulafungin, caspofungin, and flucytosine. Results The clinical diagnoses of the patients were candidemia (n=27, 50%), catheter-related blood stream infection (n=1, 1.8%), urinary tract infection (n=13, 24%), surgical site infection (n=4, 7.4%), intraabdominal infection (n=3, 5.5%), empyema (n=2, 3.7%), and pneumonia (n=4, 7.4%). The most common isolated agent was C. albicans (n=27, 50%) and the others were C. parapsilosis (n=13, 24%), C. tropicalis (n=6, 11.1%), C. glabrata (n=3, 5.6%), C. lusitaniae (n=2, 3.7%), and unspecified Candida spp. (n=3, 5.6%). Fluconazole resistance was 7.4% among all isolates. Resistance against itraconazole, ketoconazole, anidulafungin, voriconazole and caspofungin were 33.3%, 12.5%, 11.1%, 5%, and 2.5%, respectively. Isolates presented intermediate resistance against itraconazole (41.7%), voriconazole (5.6%), and amphotericin B (3.7%) to varying extents. All of the isolates were susceptible to flucytosine. Conclusions In our clinic, C. albicans and non-albicans Candida species were equally distributed and antifungal susceptibilities against major antifungal agents such as fluconazole, amphotericin B, and caspofungin were found considerably high. PMID:29062248

Tools for assessing kinship, population structure, phylogeography, and interspecific hybridization in Asian carps invasive to the Mississippi River, USA: isolation and characterization of novel tetranucleotide microsatellite DNA loci in silver carp Hypophthalmichthys molitrix

USGS Publications Warehouse

King, T.L.; Eackles, M.S.; Chapman, D.C.

2011-01-01

We document the isolation and characterization of novel tetranucleotide microsatellite DNA markers for the invasive silver carp Hypophthalmichthys molitrix and provide the results of cross-species amplification for three additional invasive carp species: bighead (H. nobilis), grass (Ctenopharyngodon idella) and black (Mylopharyngodon piceus). In the target species these markers yielded levels of allelic diversity (average 4.4 alleles/locus) and heterozygosity (average 54.7%) sufficient to: (1) provide unique multilocus genotypes; (2) delineate kinship relationships; (3) differentiate populations/species; (4) estimate effective population sizes; and (5) provide unique demographic perspectives for control or eradication. Currently these markers are being utilized to determine the degree of introgressive hybridization between H. molitrix and H. nobilis, to quantify gene flow between different sub-basins established in the central United States, and to assess the demographic status of sub-basin groups. This information will be critically important in the management/control of these invasive species.

Distribution of genes encoding virulence factors and molecular analysis of Shigella spp. isolated from patients with diarrhea in Kerman, Iran.

PubMed

Hosseini Nave, Hossein; Mansouri, Shahla; Emaneini, Mohammad; Moradi, Mohammad

2016-03-01

Shigella is one of the important causes of diarrhea worldwide. Shigella has several virulence factors contributing in colonization and invasion of epithelial cells and eventually death of host cells. The present study was performed in order to investigate the distribution of virulence factors genes in Shigella spp. isolated from patients with acute diarrhea in Kerman, Iran as well as the genetic relationship of these isolates. A total of 56 isolates including 31 S. flexneri, 18 S. sonnei and 7 S. boydii were evaluated by polymerase chain reaction (PCR) for the presence of 11 virulence genes (ipaH, ial, set1A, set1B, sen, virF, invE, sat, sigA, pic and sepA). Then, the clonal relationship of these strains was analyzed by multilocus variable-number tandem repeat analysis (MLVA) method. All isolates were positive for ipaH gene. The other genes include ial, invE and virF were found in 80.4%, 60.7% and 67.9% of the isolates, respectively. Both set1A and set1B were detected in 32.3% of S. flexneri isolates, whereas 66.1% of the isolates belonging to different serogroup carried sen gene. The sat gene was present in all S. flexneri isolates, but not in the S. sonnei and S. boydii isolates. The result showed, 30.4% of isolates were simultaneously positive and the rest of the isolates were negative for sepA and pic genes. The Shigella isolates were divided into 29 MLVA types. This study, for the first time, investigated distribution of 11 virulence genes in Shigella spp. Our results revealed heterogeneity of virulence genes in different Shigella serogroups. Furthermore, the strains belonging to the same species had little diversity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Phytotoxic activity against Bromus tectorum for secondary metabolites of a seed-pathogenic Fusarium strain belonging to the F. tricinctum species complex.

PubMed

Masi, Marco; Meyer, Susan; Pescitelli, Gennaro; Cimmino, Alessio; Clement, Suzette; Peacock, Beth; Evidente, Antonio

2017-12-01

The winter annual grass Bromus tectorum (cheatgrass) has become highly invasive in semiarid ecosystems of western North America. In these areas, a natural phenomenon, complete cheatgrass stand failure ('die-off'), is apparently caused by a complex interaction among soilborne fungal pathogens. Several Fusarium strains belonging to the Fusarium tricinctum species complex were isolated from these soils and found to be pathogenic on B. tectorum seeds. One of these strains was produced in cheatgrass seed culture to evaluate its ability to produce phytotoxins. Six metabolites were isolated and identified by spectroscopic methods (essentially 1D and 2D NMR and ESIMS) as acuminatopyrone (1), blumenol A (2), chlamydosporol (3), isochlamydosporol (4), ergosterol (5) and 4-hydroxybenzaldehyde (6). Upon testing against B. tectorum in a seedling bioassay, (6) the coleoptile and radicle length of cheatgrass seedlings were significantly reduced. Compounds 1 and 2 showed moderate activity, while 3-5 were not significantly different from the control.

[Presumptive identification of Candida spp. and other clinically important yeasts: usefulness of Brilliance Candida Agar].

PubMed

Alfonso, Claudia; López, Mónica; Arechavala, Alicia; Perrone, María Del Carmen; Guelfand, Liliana; Bianchi, Mario

2010-06-30

Fungal infections caused by yeasts have increased during the last decades and invasive forms represent a serious problem for human health. Candida albicans is the species most frequently isolated from clinical samples. However, other emerging yeast pathogens are increasingly responsible for mycotic infections, and some of them are resistant to some antifungal drugs. Consequently, it is necessary to have methods that can provide a rapid presumptive identification at species level. Numerous chromogenic agar media have been shown to be of value as diagnostic tools. We have compared a chromogenic medium, Brilliance Candida Agar, with CHROMagar Candida, the chromogenic medium most used in our country. A multicentre study was conducted in 16 Hospitals belonging to the Mycology Net of Buenos Aires City Government. A total of 240 yeast isolates were included in this research. The new chromogenic agar showed results very similar to those obtained with CHROMagar Candida. Copyright 2009 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

The effect of emerald ash borer-caused tree mortality on the invasive shrub Amur honeysuckle and their combined effects on tree and shrub seedlings

Treesearch

Brian M. Hoven; David L. Gorchov; Kathleen S. Knight; Valerie E. Peters

2017-01-01

Invasive insects and plants are major threats to the health and viability of North American forests. Emerald ash borer (Agrilus planipennis) (EAB) may cause extensive changes to forest composition due to rapid ash (Fraxinus spp.) mortality. Invasive shrubs like Amur honeysuckle (Lonicera maackii) may...

Molecular epidemiology of Streptococcus agalactiae isolated from mastitis in Brazilian dairy herds.

PubMed

Carvalho-Castro, Glei A; Silva, Juliana R; Paiva, Luciano V; Custódio, Dircéia A C; Moreira, Rafael O; Mian, Glaucia F; Prado, Ingrid A; Chalfun-Junior, Antônio; Costa, Geraldo M

Streptococcus agalactiae is one of the most common pathogens leading to mastitis in dairy herds worldwide; consequently, the pathogen causes major economic losses for affected farmers. In this study, multilocus sequence typing (MLST), genotypic capsular typing by multiplex polymerase chain reaction (PCR), and virulence gene detection were performed to address the molecular epidemiology of 59 bovine (mastitis) S. agalactiae isolates from 36 dairy farms located in the largest milk-producing mesoregions in Brazil (Minas Gerais, São Paulo, Paraná, and Pernambuco). We screened for the virulence genes bac, bca, bibA, cfb, hylB, fbsA, fbsB, PI-1, PI-2a, and PI-2b, which are associated with adhesion, invasion, tissue damage, and/or immune evasion. Furthermore, five capsular types were identified (Ia, Ib, II, III, and IV), and a few isolates were classified as non-typeable (NT). MLST revealed the following eight sequence types (STs): ST-61, ST-67, ST-103, ST-146, ST-226, ST-314, and ST-570, which were clustered in five clonal complexes (CC64, CC67, CC103, CC17, and CC314), and one singleton, ST-91. Among the virulence genes screened in this study, PI-2b, fbsB, cfb, and hylB appear to be the most important during mastitis development in cattle. Collectively, these results establish the molecular epidemiology of S. agalactiae isolated from cows in Brazilian herds. We believe that the data presented here provide a foundation for future research aimed at developing and implementing new preventative and treatment options for mastitis caused by S. agalactiae. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Detecting Genetic Introgression: High Levels of Intersubspecific Recombination Found in Xylella fastidiosa in Brazil

PubMed Central

Yuan, Xiaoli; Bromley, Robin E.; Stouthamer, Richard

2012-01-01

Documenting the role of novel mutation versus homologous recombination in bacterial evolution, and especially in the invasion of new hosts, is central to understanding the long-term dynamics of pathogenic bacteria. We used multilocus sequence typing (MLST) to study this issue in Xylella fastidiosa subsp. pauca from Brazil, a bacterium causing citrus variegated chlorosis (CVC) and coffee leaf scorch (CLS). All 55 citrus isolates typed (plus one coffee isolate) defined three similar sequence types (STs) dominated by ST11 (85%), while the remaining 22 coffee isolates defined two STs, mainly ST16 (74%). This low level of variation masked unusually large allelic differences (>1% divergence with no intermediates) at five loci (leuA, petC, malF, cysG, and holC). We developed an introgression test to detect whether these large differences were due to introgression via homologous recombination from another X. fastidiosa subspecies. Using additional sequencing around these loci, we established that the seven randomly chosen MLST targets contained seven regions of introgression totaling 2,172 bp of 4,161 bp (52%), only 409 bp (10%) of which were detected by other recombination tests. This high level of introgression suggests the hypothesis that X. fastidiosa subsp. pauca became pathogenic on citrus and coffee (crops cultivated in Brazil for several hundred years) only recently after it gained genetic variation via intersubspecific recombination, facilitating a switch from native hosts. A candidate donor is the subspecies infecting plum in the region since 1935 (possibly X. fastidiosa subsp. multiplex). This hypothesis predicts that nonrecombinant native X. fastidiosa subsp. pauca (not yet isolated) does not cause disease in citrus or coffee. PMID:22544234

Detecting genetic introgression: high levels of intersubspecific recombination found in Xylella fastidiosa in Brazil.

PubMed

Nunney, Leonard; Yuan, Xiaoli; Bromley, Robin E; Stouthamer, Richard

2012-07-01

Documenting the role of novel mutation versus homologous recombination in bacterial evolution, and especially in the invasion of new hosts, is central to understanding the long-term dynamics of pathogenic bacteria. We used multilocus sequence typing (MLST) to study this issue in Xylella fastidiosa subsp. pauca from Brazil, a bacterium causing citrus variegated chlorosis (CVC) and coffee leaf scorch (CLS). All 55 citrus isolates typed (plus one coffee isolate) defined three similar sequence types (STs) dominated by ST11 (85%), while the remaining 22 coffee isolates defined two STs, mainly ST16 (74%). This low level of variation masked unusually large allelic differences (>1% divergence with no intermediates) at five loci (leuA, petC, malF, cysG, and holC). We developed an introgression test to detect whether these large differences were due to introgression via homologous recombination from another X. fastidiosa subspecies. Using additional sequencing around these loci, we established that the seven randomly chosen MLST targets contained seven regions of introgression totaling 2,172 bp of 4,161 bp (52%), only 409 bp (10%) of which were detected by other recombination tests. This high level of introgression suggests the hypothesis that X. fastidiosa subsp. pauca became pathogenic on citrus and coffee (crops cultivated in Brazil for several hundred years) only recently after it gained genetic variation via intersubspecific recombination, facilitating a switch from native hosts. A candidate donor is the subspecies infecting plum in the region since 1935 (possibly X. fastidiosa subsp. multiplex). This hypothesis predicts that nonrecombinant native X. fastidiosa subsp. pauca (not yet isolated) does not cause disease in citrus or coffee.

Invasive Infections Caused by Nannizziopsis spp. Molds in Immunocompromised Patients.

PubMed

Nourrisson, Céline; Vidal-Roux, Magali; Cayot, Sophie; Jacomet, Christine; Bothorel, Charlotte; Ledoux-Pilon, Albane; Anthony-Moumouni, Fanny; Lesens, Olivier; Poirier, Philippe

2018-03-01

We report 2 new cases of invasive infections caused by Nannizziopsis spp. molds in France. Both patients had cerebral abscesses and were immunocompromised. Both patients had recently spent time in Africa.

Invasion of vascular cells in vitro by Porphyromonas endodontalis.

PubMed

Dorn, B R; Harris, L J; Wujick, C T; Vertucci, F J; Progulske-Fox, A

2002-04-01

The objective of this study was to determine whether laboratory strains and clinical isolates of microorganisms associated with root canal infections can invade primary cultures of cardiovascular cells. Quantitative levels of bacterial invasion of human coronary artery endothelial cells (HCAEC) and coronary artery smooth muscle cells (CASMC) were measured using a standard antibiotic protection assay. Transmission electron microscopy was used to confirm and visualize internalization within the vascular cells. Of the laboratory and clinical strains tested, only P. endodontalis ATCC 35406 was invasive in an antibiotic protection assay using HCAEC and CASMC. Invasion of P. endodontalis ATCC 35406 was confirmed by transmission electron microscopy. Certain microorganisms associated with endodontic infections are invasive. If bacterial invasion of the vasculature contributes to the pathogenesis of cardiovascular disease, then microorganisms in the pulp chamber represent potential pathogens.

High diversity of non-sporulating moulds in respiratory specimens of immunocompromised patients: should all the species be reported when diagnosing invasive aspergillosis?

PubMed

Garcia-Hermoso, Dea; Alanio, Alexandre; Cabaret, Odile; Olivi, Martine; Foulet, Françoise; Cordonnier, Catherine; Costa, Jean-Marc; Bretagne, Stéphane

2015-09-01

Non-sporulating moulds (NSMs) isolated from respiratory specimens are usually discarded without further testing although they may have pathogenic effects in immunocompromised patients. The objective of this study was to determine the identity and frequency of NSMs in patients with haematological malignancies. We analysed the mycological results of 251 consecutive respiratory samples from 104 haematology patients. Yeast and sporulating moulds were identified at the genus/species level according to their phenotypic features. NSMs were identified by internal transcribed spacer (ITS) sequencing. We detected 179 positive samples, of which 10.1% (18/179) were mixtures of moulds and 26.3% (47/179) were mixtures of moulds and yeast. We identified 142 moulds belonging to 11 different genera/species or groups, with Aspergillus fumigatus (n = 50), Penicillium spp. (n = 31) and NSM (n = 24) being the most frequently isolated species. Twenty-two NSMs were successfully sequenced: 18 were basidiomycetes and six were ascomycetes, corresponding to 16 different genera/species. NSMs were isolated with A. fumigatus in the same sample or in a subsequent sample in five patients with probable invasive aspergillosis. The conclusion is that the respiratory specimens of immunocompromised patients frequently contain very diverse mould species that may increase the virulence of pathogenic species. Reporting all mould species isolated when diagnosing invasive fungal infection could test this hypothesis. © 2015 Blackwell Verlag GmbH.

Serotype distribution of invasive Streptococcus pneumoniae in Canada during the introduction of the 13-valent pneumococcal conjugate vaccine, 2010.

PubMed

Demczuk, Walter H B; Martin, Irene; Griffith, Averil; Lefebvre, Brigitte; McGeer, Allison; Shane, Amanda; Zhanel, George G; Tyrrell, Gregory J; Gilmour, Matthew W

2012-08-01

A baseline serotype distribution was established by age and region for 2058 invasive Streptococcus pneumoniae isolates collected during the implementation period of the 13-valent pneumococcal conjugate vaccine (PCV13) program in many parts of Canada in 2010. Serotypes 19A, 7F, and 3 were the most prevalent in all age groups, accounting for 57% in <2 year olds, 62% in 2-4 year olds, 45% in 5-14 year olds, 44% in 15-49 year olds, 41% in 50-64 year olds, and 36% in ≥65 year olds. Serotype 19A was most predominant in Western and Central Canada representing 15% and 22%, respectively, of the isolates from those regions, whereas 7F was most common in Eastern Canada with 20% of the isolates. Other prevalent serotypes include 15A, 23B, 12F, 22F, and 6C. PCV13 serotypes represented 65% of the pneumococci isolated from <2 year olds, 71% of 2-4 year olds, 61% of 5-14 year olds, 60% of 15-49 year olds, 53% of 50-64 year olds, and 49% of the ≥65 year olds. Continued monitoring of invasive pneumococcal serotypes in Canada is important to identify epidemiological trends and assess the impact of the newly introduced PCV13 vaccine on public health.

A mistletoe tale: postglacial invasion of Psittacanthus schiedeanus (Loranthaceae) to Mesoamerican cloud forests revealed by molecular data and species distribution modeling.

PubMed

Ornelas, Juan Francisco; Gándara, Etelvina; Vásquez-Aguilar, Antonio Acini; Ramírez-Barahona, Santiago; Ortiz-Rodriguez, Andrés Ernesto; González, Clementina; Mejía Saules, María Teresa; Ruiz-Sanchez, Eduardo

2016-04-12

Ecological adaptation to host taxa is thought to result in mistletoe speciation via race formation. However, historical and ecological factors could also contribute to explain genetic structuring particularly when mistletoe host races are distributed allopatrically. Using sequence data from nuclear (ITS) and chloroplast (trnL-F) DNA, we investigate the genetic differentiation of 31 Psittacanthus schiedeanus (Loranthaceae) populations across the Mesoamerican species range. We conducted phylogenetic, population and spatial genetic analyses on 274 individuals of P. schiedeanus to gain insight of the evolutionary history of these populations. Species distribution modeling, isolation with migration and Bayesian inference methods were used to infer the evolutionary transition of mistletoe invasion, in which evolutionary scenarios were compared through posterior probabilities. Our analyses revealed shallow levels of population structure with three genetic groups present across the sample area. Nine haplotypes were identified after sequencing the trnL-F intergenic spacer. These haplotypes showed phylogeographic structure, with three groups with restricted gene flow corresponding to the distribution of individuals/populations separated by habitat (cloud forest localities from San Luis Potosí to northwestern Oaxaca and Chiapas, localities with xeric vegetation in central Oaxaca, and localities with tropical deciduous forests in Chiapas), with post-glacial population expansions and potentially corresponding to post-glacial invasion types. Similarly, 44 ITS ribotypes suggest phylogeographic structure, despite the fact that most frequent ribotypes are widespread indicating effective nuclear gene flow via pollen. Gene flow estimates, a significant genetic signal of demographic expansion, and range shifts under past climatic conditions predicted by species distribution modeling suggest post-glacial invasion of P. schiedeanus mistletoes to cloud forests. However, Approximate Bayesian Computation (ABC) analyses strongly supported a scenario of simultaneous divergence among the three groups isolated recently. Our results provide support for the predominant role of isolation and environmental factors in driving genetic differentiation of Mesoamerican parrot-flower mistletoes. The ABC results are consistent with a scenario of post-glacial mistletoe invasion, independent of host identity, and that habitat types recently isolated P. schiedeanus populations, accumulating slight phenotypic differences among genetic groups due to recent migration across habitats. Under this scenario, climatic fluctuations throughout the Pleistocene would have altered the distribution of suitable habitat for mistletoes throughout Mesoamerica leading to variation in population continuity and isolation. Our findings add to an understanding of the role of recent isolation and colonization in shaping cloud forest communities in the region.

[Susceptibility to azoles and amphotericin B of isolates of Candida spp. Experience of a university health network, between 2004 and 2010].

PubMed

Porte, Lorena; León, Pilar; Gárate, Cynthia; Guzmán, Ana María; Labarca, Jaime; García, Patricia

2012-04-01

To describe antifungal susceptibility testing surveillance (December 2004-September 2010) in Candida spp., for amphotericin B, fluconazole and voriconazole, at the Laboratorio de Microbiología, Pontificia Universidad Católica de Chile. The study was performed utilizing E test and included yeasts from invasive origin and isolates in which antifungal susceptibility testing was asked for by the patient's physician. The yeasts were mainly recovered from urine samples (n: 64), blood cultures (n: 51) and secretions (n: 24). Two hundred ninety three isolates were studied: C. albicans (38%), C. glabrata (30%), C. tropicalis (11%), C. parapsilosis (10%), C. krusei (4%) and others (7%). All Candida species were 100% susceptible to amphotericin B, except C. krusei (1/12). Fluconazole's global susceptibility in C. albicans was 91.8%, but 100% in isolates from blood cultures versus 76% in isolates from urine. C. tropicalis was 93.9% susceptible to fluconazole, C. parapsilosis, 90% and C. glabrata 30.3%. C. krusei had no susceptible isolates to fluconazole. Voriconazole resistance was mainly present in C. glabrata (11.5%). We recommend the study of antifungal susceptibility in isolates from invasive origin, selected urine strains and C. glabrata. Fluconazole remains effective in C. albicans from blood.

Terrestrial animals as invasive species and as species at risk from invasions

Treesearch

Deborah M. Finch; Dean Pearson; Joseph Wunderle; Wayne Arendt

2010-01-01

Including terrestrial animal species in the invasive species strategy plan is an important step in invasive species management. Invasions by nonindigenous species threaten nearly 50 percent of imperiled native species in the United States and are the Nation's second leading cause of species endangerment. Invasion and conversion of native habitats by exotic species...

[Surveillance of Neisseria meningitidis in Argentina, 1993-2005: distribution of serogroups, serotypes and serosubtypes isolated from invasive disease].

PubMed

Chiávetta, L; Chávez, E; Ruzic, A; Mollerach, M; Regueira, M

2007-01-01

Neisseria meningitidis is an important cause of meningitis, bacteremia and septic shock syndrome. We herein present the distribution of serogroups, serotypes and serosubtypes of 2244 isolates of N. meningitidis from patients with meningitis or meningococcemia, received within the period 1993-2005, in the National Reference Laboratory, INEI-ANLIS "Dr. Carlos G. Malbrán", from 33 Argentine hospitals that are included in a National Network devoted to for the study of bacterial meningitis. Between 1993-1995, serogroup B was prevalent (66%) whereas in the period from 1995-2001, serogroup C prevailed (65%). However, following but after that period, the prevalence of serogroup B was recovered. In the last 5 years of the studied period, the serogroups Y and W135 represented as a whole a 15.6% as a whole whereas up to the year 2000 during the first 6 years they accounted for it was of 4.7%. Higher diversity in the distribution of serotypes and serosubtypes was observed within serogroup B. The nonsubtypable isolates throughout the period of study represented the 52.8%, this high percentage demonstrates the limited capacity of the serotyping for the determination of meningococcal/meningococcus subtypes. of meningococco.

Isolation of Cryptococcus neoformans and other opportunistic fungi from pigeon droppings.

PubMed

Soltani, Maryam; Bayat, Mansour; Hashemi, Seyed J; Zia, Mohammadali; Pestechian, Nader

2013-01-01

Invasive fungal infections cause considerable morbidity and mortality in immunocompromised hosts. Pigeon droppings could especially be a potential carrier in the spread of pathogenic yeasts and mold fungi into the environment. The objective of this study was to isolation of Cryptococcus neoformans and other opportunistic fungi from pigeon droppings. One hundred twenty samples of pigeon droppings were suspended 1:10 in saline solution and then cultured. Identification of C. neoformans was performed on bird seed agar, presence of a capsule on India ink preparation, urease production on urea agar medium and RapID yeast plus system. The identification of candida species was based on micro-morphological analysis on corn meal-Tween 80 agar, RapID yeast plus system and growth in CHROMagar candida. The identification of other fungi was based on macromorphologic, microscopic, biochemical and physiological characteristics. The highest frequency of yeasts and mold fungi were observed in Candida albicans 6.6% and Penicillium spp. 25%. The frequency rate of C. neoformans isolation was 2.5%. Several types of fungi are present in pigeon droppings that can spread in environment and transmit to children and elderly as well as immunocompromised patients who are at increased risk of contracting opportunistic diseases.

Molecular Identification of Malassezia Species in Patients with Malassezia folliculitis in Sfax, Tunisia.

PubMed

Cheikhrouhou, F; Guidara, R; Masmoudi, A; Trabelsi, H; Neji, S; Sellami, H; Makni, F; Ayadi, A

2017-06-01

Malassezia folliculitis is caused by the invasion of hair follicles by large numbers of Malassezia cells. Several Malassezia researches still use cultures, morphology and biochemical techniques. The aim of this study was to identify Malassezia species isolated from patients diagnosed with folliculitis, at the Parasitology and Mycology Laboratory of Sfax University Hospital, and to explore the genetic diversity of Malassezia by using PCR-RFLP and PCR-sequencing targeting the rDNA region of the Malassezia genome. Specimens were taken from 27 patients with Malassezia folliculitis. For the molecular identification, PCR amplification of the 26S rDNAD1/D2 region was carried out using the Malup and Maldown primers and three restriction enzymes (BanI, MspI and HeaII) for RFLP analysis. The nucleotide sequences of each isolate were compared to those in the NCBI GenBank by using BLASTIN algorithm. Three species of Malassezia yeasts were identified among the 31 Malassezia strains isolated: M. globosa (83.9%), M. sympodialis (12. 9%) and M. furfur (3.2%). The sequence analysis of M. globosa showed six genotypes. There is a high genotypic variability of M. globosa colonizing patients with folliculitis.

Percutaneous Isolated Hepatic Perfusion for the Treatment of Unresectable Liver Malignancies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burgmans, Mark C., E-mail: m.c.burgmans@lumc.nl; Leede, Eleonora M. de, E-mail: e.m.de-leede@lumc.nl; Martini, Christian H., E-mail: c.h.martini@lumc.nl

2016-06-15

Liver malignancies are a major burden of disease worldwide. The long-term prognosis for patients with unresectable tumors remains poor, despite advances in systemic chemotherapy, targeted agents, and minimally invasive therapies such as ablation, chemoembolization, and radioembolization. Thus, the demand for new and better treatments for malignant liver tumors remains high. Surgical isolated hepatic perfusion (IHP) has been shown to be effective in patients with various hepatic malignancies, but is complex, associated with high complication rates and not repeatable. Percutaneous isolated liver perfusion (PHP) is a novel minimally invasive, repeatable, and safer alternative to IHP. PHP is rapidly gaining interest andmore » the number of procedures performed in Europe now exceeds 200. This review discusses the indications, technique and patient management of PHP and provides an overview of the available data.« less

MT1-MMP is a crucial promotor of synovial invasion in human rheumatoid arthritis

PubMed Central

Miller, Mary-Clare; Manning, Hugh B.; Jain, Abhilash; Troeberg, Linda; Dudhia, Jayesh; Essex, David; Sandison, Ann; Seiki, Motoharu; Nanchahal, Jagdeep; Nagase, Hideaki; Itoh, Yoshifumi

2010-01-01

Objective A hallmark of rheumatoid arthritis (RA) is invasion of the synovial pannus into cartilage and this step requires degradation of the collagen matrix. The aim of this study was to explore the role of one of the collagen-degrading matrix metalloproteinases (MMPs), membrane-type 1 MMP (MT1-MMP), in synovial pannus invasiveness. Methods Expression and localization of MT1-MMP in human RA pannus were investigated by Western blot analysis of primary synovial cells and immunohistochemistry of RA joints specimens. The functional role of MT1-MMP was analyzed by 3D collagen invasion assays and a cartilage invasion assay in the presence or absence of tissue inhibitor of metalloproteinase (TIMP)-1, TIMP-2, or GM6001. The effect of adenoviral expression of a dominant negative MT1-MMP construct lacking a catalytic domain was also examined. Results MT1-MMP was highly expressed at the pannus-cartilage junction of RA joints. Freshly isolated rheumatoid synovial tissues and isolated RA synovial fibroblasts invaded into a 3D collagen matrix in an MT1-MMP-dependent manner. Invasion was blocked by TIMP-2 and GM6001, but not by TIMP-1. It was also inhibited by the over-expression of a dominant negative MT1-MMP which inhibits collagenolytic activity and proMMP-2 activation by MT1-MMP on the cell surface. Synovial fibroblasts also invaded into cartilage in an MT1-MMP-dependent manner. This process was further enhanced by removing aggrecan from the cartilage matrix. Conclusion MT1-MMP is an essential collagen-degrading proteinase during pannus invasion in human RA. Specific inhibition of MT1-MMP-dependent invasion may form a novel therapeutic strategy for RA. PMID:19248098

Targeting Metastasis with Snake Toxins: Molecular Mechanisms

PubMed Central

Urra, Félix A.

2017-01-01

Metastasis involves the migration of cancer cells from a primary tumor to invade and establish secondary tumors in distant organs, and it is the main cause for cancer-related deaths. Currently, the conventional cytostatic drugs target the proliferation of malignant cells, being ineffective in metastatic disease. This highlights the need to find new anti-metastatic drugs. Toxins isolated from snake venoms are a natural source of potentially useful molecular scaffolds to obtain agents with anti-migratory and anti-invasive effects in cancer cells. While there is greater evidence concerning the mechanisms of cell death induction of several snake toxin classes on cancer cells; only a reduced number of toxin classes have been reported (i.e., disintegrins/disintegrin-like proteins, C-type lectin-like proteins, C-type lectins, serinproteases, cardiotoxins, snake venom cystatins) as inhibitors of adhesion, migration, and invasion of cancer cells. Here, we discuss the anti-metastatic mechanisms of snake toxins, distinguishing three targets, which involve (1) inhibition of extracellular matrix components-dependent adhesion and migration, (2) inhibition of epithelial-mesenchymal transition, and (3) inhibition of migration by alterations in the actin/cytoskeleton network. PMID:29189742

[Fungemia due to Trichosporon asahii in a patient with hematological malignancy].

PubMed

Odero, Valle; Galán-Sánchez, Fátima; García-Agudo, Lidia; García-Tapia, Ana M; Guerrero-Lozano, Inmaculada; Rodríguez-Iglesias, Manuel A

2015-01-01

Trichosporonosis is an opportunistic infection caused by the genus Trichosporon. The majority of cases of invasive trichosporonosis occurs in immunocompromised individuals. We describe a case of disseminated infection by Trichosporon asahii in a hematology patient. A 52-year-old man diagnosed with acute lymphoblastic leukemia developed a febrile episode during the third cycle of the induction chemotherapy. The blood cultures were positive after 24h incubation, showing elongated structures compatible with fungal elements in the Gram stain. The identification of the fungus as Trichosporon asahii was carried out by the assimilation of compounds of carbon and the amplification and sequencing of the D1/D2 domain and the internal transcribed spacer of the ribosomal DNA. The fungus was also isolated from the pustular lesions that the patient had in the chest. After treatment with amphotericin B, the patient progressed satisfactorily. Trichosporon asahii is an emergent pathogen in immunosupressed patients and its presence should not be considered as colonization, as there is risk of invasive infection. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Phytotoxic substance with allelopathic activity in Brachiaria decumbens.

PubMed

Kobayashi, Ai; Kato-Noguchi, Hisashi

2015-05-01

The grass Brachiaria decumbens becomes naturalized and quickly dominant in non-native areas. It was hypothesized that phytotoxic substances of plants may contribute to the domination and invasion of the plants. However, no potent phytotoxic substance has been reported in B. decumbens. Therefore, we searched for phytotoxic substances with allelopathic activity in this species. An aqueous methanol extract of B. decumbens inhibited the growth of roots and shoots of cress (Lepidium sativum), lettuce (Lactuca sativa), timothy (Phleum pratense) and ryegrass (Lolium multiflorum) seedlings. The extract was then purified using chromatographic methods and a phytotoxic substance with allelopathic activity was isolated and identified by spectral analysis as (6R,9S)-3-oxo-α-ionol. These results suggest that this compound may contribute to the allelopathic effect caused by the B. decumbens extract and may be in part responsible for the invasion and domination of B. decumbens. Two other Brachiaria species, B. brizantha and a Brachiaria hybrid were also confirmed to contain (6R,9S)-3-oxo-α-ionol. Therefore, this compound may play an important role in the phytotoxicity of the Brachiaria species.

Analysis of Sequence Diversity at the Highly Polymorphic Cpgp40/15 Locus among Cryptosporidium Isolates from Human Immunodeficiency Virus-Infected Children in South Africa

PubMed Central

Leav, Brett A.; Mackay, Malanie R.; Anyanwu, Akudo; O' Connor, Roberta M.; Cevallos, Ana Maria; Kindra, Gurpreet; Rollins, Nigel C.; Bennish, Michael L.; Nelson, Richard G.; Ward, Honorine D.

2002-01-01

Cryptosporidium sp. is a significant cause of diarrheal disease, particularly in human immunodeficiency virus (HIV)-infected patients in developing countries. We recently cloned and sequenced several alleles of the highly polymorphic single-copy Cryptosporidium parvum gene Cpgp40/15. This gene encodes a precursor protein that is proteolytically cleaved to yield mature cell surface glycoproteins gp40 and gp15, which are implicated in zoite attachment to and invasion of enterocytes. The most-striking feature of the Cpgp40/15 alleles and proteins is their unprecedented degree of sequence polymorphism, which is far greater than that observed for any other gene or protein studied in C. parvum to date. In this study we analyzed nucleic acid and amino acid sequence polymorphism at the Cpgp40/15 locus of 20 C. parvum isolates from HIV-infected South African children. Fifteen isolates exhibited one of four previously identified genotype I alleles at the Cpgp40/15 locus (Ia, Ib, Ic, and Id), while five displayed a novel set of polymorphisms that defined a new Cpgp40/15 genotype I allele, designated genotype Ie. Surprisingly, only 15 of these isolates exhibited concordant type I alleles at the thrombospondin-related adhesive protein of Cryptosporidium and Cryptosporidium oocyst wall protein loci, while five isolates (all of which displayed Cpgp40/15 genotype Ic alleles) displayed genotype II alleles at these loci. Furthermore, the last five isolates also manifested chimeric genotype Ic/Ib or Ic/II alleles at the Cpgp40/15 locus, raising the possibility of sexual recombination within and between prototypal parasite genotypes. Lastly, children infected with isolates having genotype Ic alleles were significantly older than those infected with isolates displaying other genotype I alleles. PMID:12065532

Seroprevalence, Isolation, Genotyping, and Pathogenicity of Toxoplasma gondii Strains from Sheep in China

PubMed Central

Yang, YuRong; Feng, YongJie; Yao, QiuXia; Wang, YingHua; Lu, YaoYao; Liang, HongDe; Zhu, XingQuan; Zhang, LongXian

2017-01-01

Toxoplasma gondii is an important cause of reproductive failure in small ruminants that also poses a risk to consumers who consume undercooked meat. However, little is known about sheep toxoplasmosis in China for the world. Therefore, this study was conducted to assess the prevalence of T. gondii infection in sheep from China, to isolate T. gondii via bioassay in mice and to evaluate the virulence of the isolated T. gondii based on vero cell invasion and mice. A total of 840 samples (304 unfrozen hearts and 536 sera) from sheep in China were collected from 2014 to 2016. Heart samples (n = 36) of T. gondii seropositive sheep (MAT, ≥25) were bioassayed in mice individually. DNA derived from cell cultured tachyzoites of the isolated T. gondii was characterized by PCR-RFLP of 10 loci (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). The virulence of the T. gondii was evaluated based on the mortality and encystation in mice, as well as their growth characteristics in cell culture. Antibodies to T. gondii were found in 174 of 840 (20.71%, 304 hearts juice and 536 sera) sheep by the modified agglutination test (cut-off 1:25). Viable T. gondii was isolated from the hearts of two of 36 seropositive sheep hearts. Both genotypes of the sheep heart isolates were ToxoDB#9. The virulence of the two ToxoDB#9 isolations varied significantly. To the best of our knowledge, this is the first report of isolation of ToxoDB#9 strain of T. gondii from sheep in China. PMID:28217119

[Minimally invasive approach for cervical spondylotic radiculopathy].

PubMed

Ding, Liang; Sun, Taicun; Huang, Yonghui

2010-01-01

To summarize the recent minimally invasive approach for cervical spondylotic radiculopathy (CSR). The recent literature at home and abroad concerning minimally invasive approach for CSR was reviewed and summarized. There were two techniques of minimally invasive approach for CSR at present: percutaneous puncture techniques and endoscopic techniques. The degenerate intervertebral disc was resected or nucleolysis by percutaneous puncture technique if CSR was caused by mild or moderate intervertebral disc herniations. The cervical microendoscopic discectomy and foraminotomy was an effective minimally invasive approach which could provide a clear view. The endoscopy techniques were suitable to treat CSR caused by foraminal osteophytes, lateral disc herniations, local ligamentum flavum thickening and spondylotic foraminal stenosis. The minimally invasive procedure has the advantages of simple handling, minimally invasive and low incidence of complications. But the scope of indications is relatively narrow at present.

Invasive Infections Caused by Nannizziopsis spp. Molds in Immunocompromised Patients

PubMed Central

Nourrisson, Céline; Vidal-Roux, Magali; Cayot, Sophie; Jacomet, Christine; Bothorel, Charlotte; Ledoux-Pilon, Albane; Anthony-Moumouni, Fanny; Lesens, Olivier

2018-01-01

We report 2 new cases of invasive infections caused by Nannizziopsis spp. molds in France. Both patients had cerebral abscesses and were immunocompromised. Both patients had recently spent time in Africa. PMID:29460742

Potential Anticancer Properties of Osthol: A Comprehensive Mechanistic Review

PubMed Central

Shokoohinia, Yalda; Jafari, Fataneh; Mohammadi, Zeynab; Bazvandi, Leili; Hosseinzadeh, Leila; Chow, Nicholas; Bhattacharyya, Piyali; Farzaei, Mohammad Hosein; Farooqi, Ammad Ahmad; Nabavi, Seyed Mohammad; Bishayee, Anupam

2018-01-01

Cancer is caused by uncontrolled cell proliferation which has the potential to occur in different tissues and spread into surrounding and distant tissues. Despite the current advances in the field of anticancer agents, rapidly developing resistance against different chemotherapeutic drugs and significantly higher off-target effects cause millions of deaths every year. Osthol is a natural coumarin isolated from Apiaceaous plants which has demonstrated several pharmacological effects, such as antineoplastic, anti-inflammatory and antioxidant properties. We have attempted to summarize up-to-date information related to pharmacological effects and molecular mechanisms of osthol as a lead compound in managing malignancies. Electronic databases, including PubMed, Cochrane library, ScienceDirect and Scopus were searched for in vitro, in vivo and clinical studies on anticancer effects of osthol. Osthol exerts remarkable anticancer properties by suppressing cancer cell growth and induction of apoptosis. Osthol’s protective and therapeutic effects have been observed in different cancers, including ovarian, cervical, colon and prostate cancers as well as chronic myeloid leukemia, lung adenocarcinoma, glioma, hepatocellular, glioblastoma, renal and invasive mammary carcinoma. A large body of evidence demonstrates that osthol regulates apoptosis, proliferation and invasion in different types of malignant cells which are mediated by multiple signal transduction cascades. In this review, we set spotlights on various pathways which are targeted by osthol in different cancers to inhibit cancer development and progression. PMID:29301373

Entomopathogenic Fungi Associated with Exotic Invasive Insect Pests in Northeastern Forests of the USA

PubMed Central

Gouli, Vladimir; Gouli, Svetlana; Marcelino, José A. P.; Skinner, Margaret; Parker, Bruce L.

2013-01-01

Mycopathogens of economically important exotic invasive insects in forests of northeastern USA have been the subject of research at the Entomology Research Laboratory, University of Vermont, for the last 20 years. Elongate hemlock scale, European fruit lecanium, hemlock woolly adelgid and pear thrips were analyzed for the presence of mycopathogens, in order to consider the potential for managing these pests with biological control. Fungal cultures isolated from insects with signs of fungal infection were identified based on morphological characters and DNA profiling. Mycopathogens recovered from infected insects were subdivided into three groups, i.e., specialized entomopathogenic; facultative entomopathogens; ubiquitous opportunistic contaminants. Epizootics were caused by fungi in the specialized group with the exception of M. microspora, P. marquandii and I. farinosa. Inoculation of insects in laboratory and field conditions with B. bassiana, L. muscarium and Myriangium sp. caused insect mortality of 45 to 95%. Although pest populations in the field seemed severely compromised after treatment, the remnant populations re-established themselves after the winter. Although capable of inducing high mortality, a single localized aerial application of a soil-dwelling fungus does not maintain long-time suppression of pests. However, it can halt their range expansion and maintain populations below the economic threshold level without the use of expensive insecticides which have a negative impact on the environment. PMID:26462527

The Origin of Invasive Microorganisms Matters for Science, Policy, and Management: The Case of Didymosphenia geminata

PubMed Central

Taylor, Brad W.; Bothwell, Max L.

2014-01-01

The value of distinguishing native from nonnative invasive species has recently been questioned. However, this dichotomy is important for understanding whether a species’ successful dominance is caused by introductions, changing environmental conditions that facilitate an existing population, or both processes. We highlight the importance of knowing the origin of hard-to-detect invasive microorganisms for scientific research, management, and policy using a case study of recent algal blooms of the stalk-producing diatom Didymosphenia geminata. Nuisance blooms have been reported in rivers worldwide and have been hastily attributed to introductions. However, evidence indicates that blooms are probably not caused by introductions but, rather, by environmental conditions that promote excessive stalk production by this historically rare species. Effective responses to invasive microorganisms depend on knowing whether their proliferation is caused by being nonnative or is the result of changing environmental conditions that promote invasive characteristics of native species. PMID:26955071

Use of Green Fluorescent Protein-Transgenic Strains to Study Pathogenic and Nonpathogenic Lifestyles in Colletotrichum acutatum.

PubMed

Horowitz, Sigal; Freeman, Stanley; Sharon, Amir

2002-07-01

ABSTRACT Colletotrichum acutatum, which causes anthracnose disease on strawberry, can also persist on several other plant species without causing disease symptoms. The genetic and molecular bases that determine pathogenic and nonpathogenic lifestyles in C. acutatum are unclear. We developed a transformation system for C. acutatum by electroporation of germinating conidia, and transgenic isolates that express the green fluorescent protein (GFP) were produced. Details of the pathogenic and nonpathogenic lifestyles of C. acutatum were determined by using GFP-transgenic isolates. Major differences between colonization-mediating processes of strawberry and of other plants were observed. On the main host, strawberry, the germinating conidia formed branched, thick hyphae, and large numbers of appressoria were produced that were essential for plant penetration. In strawberry, the fungus developed rapidly, filling the mesophyll with dense mycelium that invaded the cells and caused necrosis of the tissue. In nonpathogenic interactions on pepper, eggplant, and tomato, the conidia germinated, producing thin, straight germ tubes. Appressoria were produced but failed to germinate and penetrate leaf tissue, resulting in epiphytic growth without invasion of the plant. Penetration of the plant occurred only several days after inoculation and was restricted to the intercellular spaces of the first cell layers of infected tissue without causing any visible damage. Much of the new fungal biomass continued to develop on the surface of inoculated organs in the nonpathogenic interaction. The differences in fungal development on strawberry compared with the other plant species suggest that signal molecules, which may be present only in strawberry, trigger appressorial germination and penetration of the primary host.

An outbreak of pneumonia associated with S. pneumoniae at a military training facility in Finland in 2006.

PubMed

Vainio, Anni; Lyytikäinen, Outi; Sihvonen, Reetta; Kaijalainen, Tarja; Teirilä, Laura; Rantala, Merja; Lehtinen, Pirkko; Ruuska, Pekka; Virolainen, Anni

2009-07-01

Streptococcus pneumoniae is a well-known cause of community-acquired bacterial pneumonia. The purpose of this study was to assess the cause and extent of the outbreak of pneumonia which occurred among military recruits following a 1-week hard encampment in Finland. We also assessed the carriage rate and molecular characteristics of the S. pneumoniae isolates. All pneumococcal isolates were studied for antibiotic susceptibility, serotyped, genotyped by multilocus sequence typing (MLST), and the presence of pneumococcal rlrA pilus islet was detected. The genotype results defined by MLST corresponded with the serotype results. S. pneumoniae serotype 7F, ST2331, seemed to be associated with an outbreak of pneumonia and nasopharyngeal carriage among 43 military recruits. Of the 43 military recruits, five (12%) were hospitalized with pneumonia and two (40%) of them were positive for S. pneumoniae serotype 7F, ST2331 by blood culture. Eighteen (42%) of the 43 men were found to be positive for S. pneumoniae by nasopharyngeal culture, and nine (50%) of them carried pneumococcal serotype 7F, ST2331. The outbreak strain covered 55% of all the pneumococcal findings. Outbreaks of invasive pneumococcal disease seem to occur in a crowded environment such as a military training facility even among previously healthy young men.

59 FR- Draft Guideline for Isolation Precautions in Hospitals: Part I. ``Evolution of Isolation...

Federal Register 2010, 2011, 2012, 2013, 2014

1994-11-07

... in pediatric populations (e.g., invasive Haemophilus influenza, Neisseria meningitides meningitis and... Precautions in Hospitals,'' and was prepared by the Hospital Infection Control Practices Advisory Committee..., DHHS; the Director, CDC; and the Director, NCID, regarding the practice of hospital infection control...

2015 Epidemic of Severe Streptococcus agalactiae Sequence Type 283 Infections in Singapore Associated With the Consumption of Raw Freshwater Fish: A Detailed Analysis of Clinical, Epidemiological, and Bacterial Sequencing Data.

PubMed

Kalimuddin, Shirin; Chen, Swaine L; Lim, Cindy T K; Koh, Tse Hsien; Tan, Thean Yen; Kam, Michelle; Wong, Christopher W; Mehershahi, Kurosh S; Chau, Man Ling; Ng, Lee Ching; Tang, Wen Ying; Badaruddin, Hishamuddin; Teo, Jeanette; Apisarnthanarak, Anucha; Suwantarat, Nuntra; Ip, Margaret; Holden, Matthew T G; Hsu, Li Yang; Barkham, Timothy

2017-05-15

Streptococcus agalactiae (group B Streptococcus [GBS]) has not been described as a foodborne pathogen. However, in 2015, a large outbreak of severe invasive sequence type (ST) 283 GBS infections in adults epidemiologically linked to the consumption of raw freshwater fish occurred in Singapore. We attempted to determine the scale of the outbreak, define the clinical spectrum of disease, and link the outbreak to contaminated fish. Time-series analysis was performed on microbiology laboratory data. Food handlers and fishmongers were screened for enteric carriage of GBS. A retrospective cohort study was conducted to assess differences in demographic and clinical characteristics of patients with invasive ST283 and non-ST283 infections. Whole-genome sequencing was performed on human and fish ST283 isolates from Singapore, Thailand, and Hong Kong. The outbreak was estimated to have started in late January 2015. Within the study cohort of 408 patients, ST283 accounted for 35.8% of cases. Patients with ST283 infection were younger and had fewer comorbidities but were more likely to develop meningoencephalitis, septic arthritis, and spinal infection. Of 82 food handlers and fishmongers screened, none carried ST283. Culture of 43 fish samples yielded 13 ST283-positive samples. Phylogenomic analysis of 161 ST283 isolates from humans and fish revealed they formed a tight clade distinguished by 93 single-nucleotide polymorphisms. ST283 is a zoonotic GBS clone associated with farmed freshwater fish, capable of causing severe disease in humans. It caused a large foodborne outbreak in Singapore and poses both a regional and potentially more widespread threat. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

A natural variant of the cysteine protease virulence factor of group A Streptococcus with an arginine-glycine-aspartic acid (RGD) motif preferentially binds human integrins alphavbeta3 and alphaIIbbeta3.

PubMed

Stockbauer, K E; Magoun, L; Liu, M; Burns, E H; Gubba, S; Renish, S; Pan, X; Bodary, S C; Baker, E; Coburn, J; Leong, J M; Musser, J M

1999-01-05

The human pathogenic bacterium group A Streptococcus produces an extracellular cysteine protease [streptococcal pyrogenic exotoxin B (SpeB)] that is a critical virulence factor for invasive disease episodes. Sequence analysis of the speB gene from 200 group A Streptococcus isolates collected worldwide identified three main mature SpeB (mSpeB) variants. One of these variants (mSpeB2) contains an Arg-Gly-Asp (RGD) sequence, a tripeptide motif that is commonly recognized by integrin receptors. mSpeB2 is made by all isolates of the unusually virulent serotype M1 and several other geographically widespread clones that frequently cause invasive infections. Only the mSpeB2 variant bound to transfected cells expressing integrin alphavbeta3 (also known as the vitronectin receptor) or alphaIIbbeta3 (platelet glycoprotein IIb-IIIa), and binding was blocked by a mAb that recognizes the streptococcal protease RGD motif region. In addition, mSpeB2 bound purified platelet integrin alphaIIbbeta3. Defined beta3 mutants that are altered for fibrinogen binding were defective for SpeB binding. Synthetic peptides with the mSpeB2 RGD motif, but not the RSD sequence present in other mSpeB variants, blocked binding of mSpeB2 to transfected cells expressing alphavbeta3 and caused detachment of cultured human umbilical vein endothelial cells. The results (i) identify a Gram-positive virulence factor that directly binds integrins, (ii) identify naturally occurring variants of a documented Gram-positive virulence factor with biomedically relevant differences in their interactions with host cells, and (iii) add to the theme that subtle natural variation in microbial virulence factor structure alters the character of host-pathogen interactions.

Severe group A streptococcal infections in a paediatric intensive care unit.

PubMed

Lithgow, Anna; Duke, Trevor; Steer, Andrew; Smeesters, Pierre Robert

2014-09-01

To describe the clinical presentation, management and outcomes for children with invasive group A streptococcal (GAS) infection in a paediatric intensive care unit (PICU). We reviewed the clinical and laboratory records of patients admitted to a PICU in Melbourne with invasive GAS infection from April 2010 to April 2013. Outcomes recorded included survival, organ failure, need for extracorporeal support, renal replacement therapy and prolonged neuromuscular weakness. Twelve cases of invasive GAS infection were identified. The most common clinical presentations were pneumonia (n=5), bacteraemia with no septic focus (n=4) and septic arthritis (n=3). Necrotising fasciitis occurred in one patient and another patient presented with ischaemic lower limbs requiring amputation. Of the eight isolates with available emm typing results, the most common emm type was emm1 (n=4) followed by emm4, 12 and 22. Nine patients had multi-organ failure. Ten patients required mechanical ventilation for a median duration of 8 days. Nine patients required inotropic and/or vasopressor support and four patients extracorporeal membrane oxygenation support. Eleven patients survived. A prolonged period of neuromuscular weakness following the initial severe illness was common (n=5), but most children returned to normal or near normal neurological function. Invasive GAS disease in children may cause severe multi-organ failure with resultant prolonged intensive care stay and significant morbidity. However, a high rate of survival and return to normal functioning may be achieved with multi-system intensive care support and multi-disciplinary rehabilitation. © 2014 The Authors. Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

Native species richness buffers invader impact in undisturbed but not disturbed grassland assemblages

Treesearch

Sarah M. Pinto; Yvette K. Ortega

2016-01-01

Many systems are prone to both exotic plant invasion and frequent natural disturbances. Native species richness can buffer the effects of invasion or disturbance when imposed in isolation, but it is largely unknown whether richness provides substantial resistance against invader impact in the face of disturbance. We experimentally examined how disturbance (...

Invasion versus isolation: Trade-offs in managing native salmonids with barriers to upstream movement

Treesearch

Kurt D. Fausch; Bruce E. Rieman; Jason B. Dunham; Michael K. Young; Douglas P. Peterson

2009-01-01

Conservation biologists often face the trade-off that increasing connectivity in fragmented landscapes to reduce extinction risk of native species can foster invasion by non-native species that enter via the corridors created, which can then increase extinction risk. This dilemma is acute for stream fishes, especially native salmonids, because their populations are...

Sub-Inhibitory Concentrations of the Antibiotic Florfenicol Reduces Invasion in Isolates of Multi-Drug Resistant Salmonella Typhimurium DT104

USDA-ARS?s Scientific Manuscript database

Virulence can be enhanced in certain bacteria that are exposed to sub-lethal levels of antibiotics. Salmonella enterica serovar Typhimurium DT104 is resistant to five different antibiotics, including florfenicol. Using real-time PCR and a tissue culture invasion assay, we investigated the impact of ...