Understanding the Mechanisms of Immunopathogenesis of Human and Bovine Tuberculosis

USDA-ARS?s Scientific Manuscript database

Extensive investigations have revealed that zoonotic pathogens in the Mycobacterium tuberculosis complex (MTBC) evolved from a common ancestor. Although all the members can cause disease in one or more species of mammals, Mycobacterium tuberculosis (Mtb) and M. bovis (Mbv) are the major pathogens ...

Bacterial pathogens of the bovine respiratory disease complex.

PubMed

Griffin, Dee; Chengappa, M M; Kuszak, Jennifer; McVey, D Scott

2010-07-01

Pneumonia caused by the bacterial pathogens discussed in this article is the most significant cause of morbidity and mortality of the BRDC. Most of these infectious bacteria are not capable of inducing significant disease without the presence of other predisposing environmental factors, physiologic stressors, or concurrent infections. Mannheimia haemolytica is the most common and serious of these bacterial agents and is therefore also the most highly characterized. There are other important bacterial pathogens of BRD, such as Pasteurella multocida, Histophulus somni, and Mycoplasma bovis. Mixed infections with these organisms do occur. These pathogens have unique and common virulence factors but the resulting pneumonic lesions may be similar. Although the amount and quality of research associated with BRD has increased, vaccination and therapeutic practices are not fully successful. A greater understanding of the virulence mechanisms of the infecting bacteria and pathogenesis of pneumonia, as well as the characteristics of the organisms that allow tissue persistence, may lead to improved management, therapeutics, and vaccines. Copyright 2010 Elsevier Inc. All rights reserved.

Streptococcus sanguinis biofilm formation & interaction with oral pathogens.

PubMed

Zhu, Bin; Macleod, Lorna C; Kitten, Todd; Xu, Ping

2018-06-08

Caries and periodontitis are the two most common human dental diseases and are caused by dysbiosis of oral flora. Although commensal microorganisms have been demonstrated to protect against pathogens and promote oral health, most previous studies have addressed pathogenesis rather than commensalism. Streptococcus sanguinis is a commensal bacterium that is abundant in the oral biofilm and whose presence is correlated with health. Here, we focus on the mechanism of biofilm formation in S. sanguinis and the interaction of S. sanguinis with caries- and periodontitis-associated pathogens. In addition, since S. sanguinis is well known as a cause of infective endocarditis, we discuss the relationship between S. sanguinis biofilm formation and its pathogenicity in endocarditis.

Treatable Bacterial Infections Are Underrecognized Causes of Fever in Ethiopian Children

PubMed Central

Aarsland, Sara J.; Castellanos-Gonzalez, Alejandro; Lockamy, Kameron P.; Mulu-Droppers, Ruth; Mulu, Moges; White, A. Clinton; Cabada, Miguel M.

2012-01-01

Febrile illnesses remain a major cause of morbidity and mortality in resource-poor countries, but too often, tests are not available to determine the causes, leading to misdiagnosis and inappropriate treatment. To determine the cause of febrile illnesses, we recovered the malaria smears from 102 children presenting with fever to Soddo Christian Hospital in Wolaitta Soddo, Ethiopia. DNA was isolated from the smears and evaluated by real-time polymerase chain reaction. We identified pathogen DNA with probes for Plasmodium spp., Streptococcus pneumoniae, Rickettsia spp., Salmonella spp., and Borrelia spp. Overall, we showed that it is possible to isolate high-quality DNA and identify treatable pathogens from malaria blood smears. Furthermore, our data showed that bacterial pathogens (especially Pneumococcus, Rickettsia spp., and Borrelia spp.) are common and frequently unrecognized but treatable causes of febrile illnesses in Ethiopian children. PMID:22764303

Vibrio Zinc-Metalloprotease Causes Photoinactivation of Coral Endosymbionts and Coral Tissue Lesions

PubMed Central

Sussman, Meir; Mieog, Jos C.; Doyle, Jason; Victor, Steven; Willis, Bette L.; Bourne, David G.

2009-01-01

Background Coral diseases are emerging as a serious threat to coral reefs worldwide. Of nine coral infectious diseases, whose pathogens have been characterized, six are caused by agents from the family Vibrionacae, raising questions as to their origin and role in coral disease aetiology. Methodology/Principal Findings Here we report on a Vibrio zinc-metalloprotease causing rapid photoinactivation of susceptible Symbiodinium endosymbionts followed by lesions in coral tissue. Symbiodinium photosystem II inactivation was diagnosed by an imaging pulse amplitude modulation fluorometer in two bioassays, performed by exposing Symbiodinium cells and coral juveniles to non-inhibited and EDTA-inhibited supernatants derived from coral white syndrome pathogens. Conclusion/Significance These findings demonstrate a common virulence factor from four phylogenetically related coral pathogens, suggesting that zinc-metalloproteases may play an important role in Vibrio pathogenicity in scleractinian corals. PMID:19225559

Manipulation of host diet to reduce gastrointestinal colonization by the opportunistic pathogen Candida albicans

USDA-ARS?s Scientific Manuscript database

Candida albicans, the most common human fungal pathogen, can cause systemic infections with a mortality rate of ~40%. Infections arise from colonization of the gastrointestinal (GI) tract, where C. albicans is part of the normal microflora. Reducing colonization in at-risk patients using antifungal ...

Laser system for identification, tracking, and control of flying insects

USDA-ARS?s Scientific Manuscript database

Flying insects are common vectors for transmission of pathogens and inflict significant harm on humans in large parts of the developing world. Besides the direct impact to humans, these pathogens also cause harm to crops and result in agricultural losses. Here, we present a laser-based system that c...

Antimicrobial active herbal compounds against Acinetobacter baumannii and other pathogens.

PubMed

Tiwari, Vishvanath; Roy, Ranita; Tiwari, Monalisa

2015-01-01

Bacterial pathogens cause a number of lethal diseases. Opportunistic bacterial pathogens grouped into ESKAPE pathogens that are linked to the high degree of morbidity, mortality and increased costs as described by Infectious Disease Society of America. Acinetobacter baumannii is one of the ESKAPE pathogens which cause respiratory infection, pneumonia and urinary tract infections. The prevalence of this pathogen increases gradually in the clinical setup where it can grow on artificial surfaces, utilize ethanol as a carbon source and resists desiccation. Carbapenems, a β-lactam, are the most commonly prescribed drugs against A. baumannii. The high level of acquired and intrinsic carbapenem resistance mechanisms acquired by these bacteria makes their eradication difficult. The pharmaceutical industry has no solution to this problem. Hence, it is an urgent requirement to find a suitable alternative to carbapenem, a commonly prescribed drug for Acinetobacter infection. In order to do this, here we have made an effort to review the active compounds of plants that have potent antibacterial activity against many bacteria including carbapenem resistant strain of A. baumannii. We have also briefly highlighted the separation and identification methods used for these active compounds. This review will help researchers involved in the screening of herbal active compounds that might act as a replacement for carbapenem.

Pathogenicity of Nectriaceous Fungi on Avocado in Australia.

PubMed

Parkinson, Louisamarie E; Shivas, Roger G; Dann, Elizabeth K

2017-12-01

Black root rot is a severe disease of young avocado trees in Australia causing black necrotic roots, tree stunting, and leaf drop prior to tree death. Nectriaceous fungi (Nectriaceae, Hypocreales), are commonly isolated from symptomatic roots. This research tested the pathogenicity of 19 isolates from Calonectria, Cylindrocladiella, Dactylonectria, Gliocladiopsis, and Ilyonectria, spp. collected from young avocado trees and other hosts. Glasshouse pathogenicity tests with 'Reed' avocado (Persea americana) seedlings confirmed that Calonectria ilicicola is a severe pathogen of avocado, causing stunting, wilting, and seedling death within 5 weeks of inoculation. Isolates of C. ilicicola from peanut, papaya, and custard apple were also shown to be aggressive pathogens of avocado, demonstrating a broad host range. An isolate of a Calonectria sp. from blueberry and avocado isolates of Dactylonectria macrodidyma, D. novozelandica, D. pauciseptata, and D. anthuriicola caused significant root rot but not stunting within 5 to 9 weeks of inoculation. An isolate of an Ilyonectria sp. from grapevine closely related to Ilyonectria liriodendri, and avocado isolates of Cylindrocladiella pseudoinfestans, Gliocladiopsis peggii, and an Ilyonectria sp. were not pathogenic to avocado.

Acanthamoeba: An Overview of the Challenges to the Development of a Consensus Methodology of Disinfection Efficacy Testing for Contact Lens Care Products.

PubMed

Brocious, Jeffrey; Tarver, Michelle E; Hampton, Denise; Eydelman, Malvina

2018-04-24

With the increasing incidence of more pathogens that can cause microbial keratitis (MK), it is necessary to periodically reassess disinfection multipurpose solutions testing requirements to ensure that relevant organisms to challenge them are being used. Current testing protocols have included common pathogens such as Pseudomonas aeruginosa, Staphylococcus aureus, Serratia marcescens, Candida albicans, and Fusarium solani but have omitted less common pathogens such as Acanthamoeba. Specifically, Acanthamoeba sp. has recently been identified as a prevalent cause of MK in certain countries. Developing an appropriate protocol for this unique organism presents a challenge, given its two distinct life stages, methods to grow the organism, encystment techniques, and many other parameters that can affect testing outcomes. Therefore, the appropriate combination of these parameters is crucial to developing a protocol that ensures consistent, accurate results. The FDA has recognized the importance of establishing a standardized testing protocol for this pathogen and embarked on research efforts to provide a recommended testing protocol for testing contact lens care products.

The Vast and Varied Global Burden of Norovirus: Prospects for Prevention and Control

PubMed Central

Lopman, Benjamin A.; Steele, Duncan; Kirkwood, Carl D.; Parashar, Umesh D.

2016-01-01

Globally, norovirus is associated with approximately one-fifth of all diarrhea cases, with similar prevalence in both children and adults, and is estimated to cause over 200,000 deaths annually in developing countries. Norovirus is an important pathogen in a number of high-priority domains: it is the most common cause of diarrheal episodes globally, the principal cause of foodborne disease outbreaks in the United States, a key health care–acquired infection, a common cause of travel-associated diarrhea, and a bane for deployed military troops. Partly as a result of this ubiquity and burden across a range of different populations, identifying target groups and strategies for intervention has been challenging. And, on top of the breadth of this public health problem, there remain important gaps in scientific knowledge regarding norovirus, especially with respect to disease in low-income settings. Many pathogens can cause acute gastroenteritis. Historically, rotavirus was the most common cause of severe disease in young children globally. Now, vaccines are available for rotavirus and are universally recommended by the World Health Organization. In countries with effective rotavirus vaccination programs, disease due to that pathogen has decreased markedly, but norovirus persists and is now the most common cause of pediatric gastroenteritis requiring medical attention. However, the data supporting the precise role of norovirus in low- and middle-income settings are sparse. With vaccines in the pipeline, addressing these and other important knowledge gaps is increasingly pressing. We assembled an expert group to assess the evidence for the global burden of norovirus and to consider the prospects for norovirus vaccine development. The group assessed the evidence in the areas of burden of disease, epidemiology, diagnostics, disease attribution, acquired immunity, and innate susceptibility, and the group considered how to bring norovirus vaccines from their current state of development to a viable product that will benefit global health. PMID:27115709

The Vast and Varied Global Burden of Norovirus: Prospects for Prevention and Control.

PubMed

Lopman, Benjamin A; Steele, Duncan; Kirkwood, Carl D; Parashar, Umesh D

2016-04-01

Globally, norovirus is associated with approximately one-fifth of all diarrhea cases, with similar prevalence in both children and adults, and is estimated to cause over 200,000 deaths annually in developing countries. Norovirus is an important pathogen in a number of high-priority domains: it is the most common cause of diarrheal episodes globally, the principal cause of foodborne disease outbreaks in the United States, a key health care-acquired infection, a common cause of travel-associated diarrhea, and a bane for deployed military troops. Partly as a result of this ubiquity and burden across a range of different populations, identifying target groups and strategies for intervention has been challenging. And, on top of the breadth of this public health problem, there remain important gaps in scientific knowledge regarding norovirus, especially with respect to disease in low-income settings. Many pathogens can cause acute gastroenteritis. Historically, rotavirus was the most common cause of severe disease in young children globally. Now, vaccines are available for rotavirus and are universally recommended by the World Health Organization. In countries with effective rotavirus vaccination programs, disease due to that pathogen has decreased markedly, but norovirus persists and is now the most common cause of pediatric gastroenteritis requiring medical attention. However, the data supporting the precise role of norovirus in low- and middle-income settings are sparse. With vaccines in the pipeline, addressing these and other important knowledge gaps is increasingly pressing. We assembled an expert group to assess the evidence for the global burden of norovirus and to consider the prospects for norovirus vaccine development. The group assessed the evidence in the areas of burden of disease, epidemiology, diagnostics, disease attribution, acquired immunity, and innate susceptibility, and the group considered how to bring norovirus vaccines from their current state of development to a viable product that will benefit global health.

Spectrum of Viral Pathogens in Blood of Malaria-Free Ill Travelers Returning to Canada.

PubMed

Kariyawasam, Ruwandi; Lau, Rachel; Eshaghi, Alireza; Patel, Samir N; Sider, Doug; Gubbay, Jonathan B; Boggild, Andrea K

2016-05-01

Malaria is the most common specific cause of fever in returning travelers, but many other vectorborne infections and viral infections are emerging and increasingly encountered by travelers. We documented common and emerging viral pathogens in malaria-negative specimens from ill travelers returning to Canada. Anonymized, malaria-negative specimens were examined for various viral pathogens by real-time PCR. Samples were positive for herpes simplex viruses 1 or 2 (n = 21, 1.6%), cytomegalovirus (n = 4, 0.3%), Epstein-Barr virus (n = 194, 14.9%), dengue virus types 1-4 (n = 27, 2.1%), chikungunya virus (n = 5, 0.4%), and hepatitis A virus (n = 12, 0.9%). Travel-acquired viral pathogens were documented in >20% of malaria-negative specimens, of which 2.5% were infected with dengue and chikungunya viruses. Our findings support the anecdotal impression that these vectorborne pathogens are emerging among persons who travel from Canada to other countries.

Severe soft tissue infection of the lower extremity caused by Haemophilus influenzae (serotype f, biotype II) in an adult patient.

PubMed

Hagiya, Hideharu; Murase, Tomoko; Naito, Hiromichi; Hagioka, Shingo; Morimoto, Naoki

2012-01-01

The infection caused by non-b-type Haemophilus influenzae has been increasing in this Hib (H.influenzae serotype b) vaccination era. H.influenzae serotype f (Hif) is considered as one of those emerging pathogens. In general, H.influenzae is a common pathogen of such as pneumonia, otitis media, and meningitis, but is rare in soft tissue infection, especially at the extremity. We report a rare case of severe soft tissue infection caused by Hif which occurred at the lower extremity of immunocompetent adult patient.

Common fungal diseases of Russian forests

Treesearch

Evgeny P. Kuz' michevl; Ella s. Sokolova; Elena G. Kulikova

2001-01-01

Describes common fungal diseases of Russian forests, including diagnostic signs and symptoms, pathogen biology, damage caused by the disease, and methods of control. The fungal diseases are divided into two groups: those that are the most common in Russian forests and those that are found only in Russia. Within each group, diseases are subdivided by plant organ...

A phylogenomic analysis of Marek’s disease virus (MDV) reveals independent paths to virulence in Eurasia and North America

USDA-ARS?s Scientific Manuscript database

Virulence determines the impact a pathogen has on the fitness of its host, yet current understanding of the evolutionary origins and causes of virulence of many pathogens is surprisingly incomplete. Here, we explore the evolution of Marek’s disease virus (MDV), a herpesvirus commonly afflicting chic...

Influenza A(H5N8) Virus Similar to Strain in Korea Causing Highly Pathogenic Avian Influenza in Germany.

PubMed

Harder, Timm; Maurer-Stroh, Sebastian; Pohlmann, Anne; Starick, Elke; Höreth-Böntgen, Detlef; Albrecht, Karin; Pannwitz, Gunter; Teifke, Jens; Gunalan, Vithiagaran; Lee, Raphael T C; Sauter-Louis, Carola; Homeier, Timo; Staubach, Christoph; Wolf, Carola; Strebelow, Günter; Höper, Dirk; Grund, Christian; Conraths, Franz J; Mettenleiter, Thomas C; Beer, Martin

2015-05-01

Highly pathogenic avian influenza (H5N8) virus, like the recently described H5N8 strain from Korea, was detected in November 2014 in farmed turkeys and in a healthy common teal (Anas crecca) in northeastern Germany. Infected wild birds possibly introduced this virus.

Are seed and cone pathogens causing significant losses in Pacific Northwest seed orchards?

Treesearch

E.E. Nelson; W.G. Thies; C.Y. Li

1986-01-01

Cones systematically collected in 1983 from eight Douglas-fir seed orchards in western Washington and Oregon yielded large numbers of common molds. Fungi isolated from apparently healthy, developing cones were similar to those from necrotic cones. Necrosis in cones aborted in early stages of development was apparently not associated with pathogenic fungi or bacteria....

Seedborne Pathogenic Fungi in Common Bean (Phaseolus vulgaris cv. INTA Rojo) in Nicaragua.

PubMed

Marcenaro, Delfia; Valkonen, Jari P T

2016-01-01

Common bean (Phaseolus vulgaris L.) is an important legume with high nutritional value. In Nicaragua, certified healthy seeds of local bean varieties are not available, and seedborne fungi have gained little attention. Here, were surveyed seedborne pathogenic fungi in an important local bean cultivar, 'INTA Rojo'. Beans grown in the four main production areas in Nicaragua (Boaco, Carazo, Estelí, Matagalpa) for future use as seed stock were sampled from four seed storehouses and six seed lots. A total of 133 fungal strains were isolated from surface-sterilized beans and inoculated to healthy lima beans (Phaseolus lunatus) under controlled conditions. Eighty-seven isolates caused symptoms of varying severity in the seedlings, including discoloration, necrotic lesions, cankers, rot, and lethal necrosis. Pathogenic isolates were divided into eight phenotypically distinguishable groups based on morphology and growth characteristics on artificial growth medium, and further identified by analysis of the internal transcribed spacer sequences (ITS1 and ITS2) of the ribosomal RNA genes. The pathogenic isolates belonged to eight genera. Fusarium spp. (F. chlamydosporum, F. equiseti, F. incarnatum), Lasiodiplodia theobromae, Macrophomina phaseolina, and Penicillium citrinum were the most damaging and common fungi found in the seed lots. Furthermore, Corynespora cassiicola, Colletotrichum capsisi, Colletotrichum gloeosporioides, Aspergillus flavus, and Diaporthe sp. (Phomopsis) were seedborne in cultivar 'INTA Rojo' and found to be pathogenic to bean seedlings. This study reveals, for the first time, many seedborne pathogenic fungi in beans in Nicaragua; furthermore, prior to this study, little information was available concerning F. equiseti, F. incarnatum, L. theobromae, C. cassiicola, and Diaporthe spp. as seedborne pathogens of common bean. Our results lay the basis for developing diagnostic tools for seed health inspection and for further study of the epidemiology, ecology, and control of the pathogenic fungi of common beans in the field.

Campylobacteriosis, Salmonellosis, Yersiniosis, and Listeriosis as Zoonotic Foodborne Diseases: A Review

PubMed Central

Chlebicz, Agnieszka; Śliżewska, Katarzyna

2018-01-01

Zoonoses are diseases transmitted from animals to humans, posing a great threat to the health and life of people all over the world. According to WHO estimations, 600 million cases of diseases caused by contaminated food were noted in 2010, including almost 350 million caused by pathogenic bacteria. Campylobacter, Salmonella, as well as Yersinia enterocolitica and Listeria monocytogenes may dwell in livestock (poultry, cattle, and swine) but are also found in wild animals, pets, fish, and rodents. Animals, often being asymptomatic carriers of pathogens, excrete them with faeces, thus delivering them to the environment. Therefore, pathogens may invade new individuals, as well as reside on vegetables and fruits. Pathogenic bacteria also penetrate food production areas and may remain there in the form of a biofilm covering the surfaces of machines and equipment. A common occurrence of microbes in food products, as well as their improper or careless processing, leads to common poisonings. Symptoms of foodborne infections may be mild, sometimes flu-like, but they also may be accompanied by severe complications, some even fatal. The aim of the paper is to summarize and provide information on campylobacteriosis, salmonellosis, yersiniosis, and listeriosis and the aetiological factors of those diseases, along with the general characteristics of pathogens, virulence factors, and reservoirs. PMID:29701663

Dermatosis due to plants (phytodermatosis).

PubMed

dos Reis, Vitor Manoel Silva

2010-01-01

Dermatosis caused by plants is relatively common and may occur by various pathogenic mechanisms. Dermatitis due to physical trauma, pharmacological action, irritation, sensitization, mediated by IgE and induced by light are described. Pseudophytodermatosis caused by plant-delivered elements is also described in the introduction to this work.

Approach to common bacterial infections: community-acquired pneumonia.

PubMed

Iroh Tam, Pui-Ying

2013-04-01

Community-acquired pneumonia (CAP) occurs more often in early childhood than at almost any other age. Many microorganisms are associated with pneumonia, but individual pathogens are difficult to identify, which poses problems in antibiotic management. This article reviews the common as well as new, emerging pathogens, as well as the guidelines for management of pediatric CAP. Current guidelines for pediatric CAP continue to recommend the use of high-dose amoxicillin for bacterial CAP and azithromycin for suspected atypical CAP (usually caused by Mycoplasma pneumoniae) in children. Copyright © 2013 Elsevier Inc. All rights reserved.

Background sequence characteristics influence the occurrence and severity of disease-causing mtDNA mutations

PubMed Central

Wei, Wei; Hudson, Gavin

2017-01-01

Inherited mitochondrial DNA (mtDNA) mutations have emerged as a common cause of human disease, with mutations occurring multiple times in the world population. The clinical presentation of three pathogenic mtDNA mutations is strongly associated with a background mtDNA haplogroup, but it is not clear whether this is limited to a handful of examples or is a more general phenomenon. To address this, we determined the characteristics of 30,506 mtDNA sequences sampled globally. After performing several quality control steps, we ascribed an established pathogenicity score to the major alleles for each sequence. The mean pathogenicity score for known disease-causing mutations was significantly different between mtDNA macro-haplogroups. Several mutations were observed across all haplogroup backgrounds, whereas others were only observed on specific clades. In some instances this reflected a founder effect, but in others, the mutation recurred but only within the same phylogenetic cluster. Sequence diversity estimates showed that disease-causing mutations were more frequent on young sequences, and genomes with two or more disease-causing mutations were more common than expected by chance. These findings implicate the mtDNA background more generally in recurrent mutation events that have been purified through natural selection in older populations. This provides an explanation for the low frequency of mtDNA disease reported in specific ethnic groups. PMID:29253894

Origin and Proliferation of Multiple-Drug Resistance in Bacterial Pathogens

PubMed Central

Chang, Hsiao-Han; Cohen, Ted; Grad, Yonatan H.; Hanage, William P.; O'Brien, Thomas F.

2015-01-01

SUMMARY Many studies report the high prevalence of multiply drug-resistant (MDR) strains. Because MDR infections are often significantly harder and more expensive to treat, they represent a growing public health threat. However, for different pathogens, different underlying mechanisms are traditionally used to explain these observations, and it is unclear whether each bacterial taxon has its own mechanism(s) for multidrug resistance or whether there are common mechanisms between distantly related pathogens. In this review, we provide a systematic overview of the causes of the excess of MDR infections and define testable predictions made by each hypothetical mechanism, including experimental, epidemiological, population genomic, and other tests of these hypotheses. Better understanding the cause(s) of the excess of MDR is the first step to rational design of more effective interventions to prevent the origin and/or proliferation of MDR. PMID:25652543

Response of different common bean lines to Phaeoisariopsis griseola in Puerto Rico

USDA-ARS?s Scientific Manuscript database

Angular leaf spot (ALS), caused by Phaeoisariopsis griseola (Sacc.) Ferraris sin. Pseudocercospora griseola (Sacc.) Crous & U. Braun., is an important disease in common bean Phaseolus vulgaris L. in the Caribbean and Central America. The wide pathogen variability makes it necessary to continuously m...

Rodents on pig and chicken farms - a potential threat to human and animal health.

PubMed

Backhans, Annette; Fellström, Claes

2012-01-01

Rodents can cause major problems through spreading various diseases to animals and humans. The two main species of rodents most commonly found on farms around the world are the house mouse (Mus musculus) and the brown rat (Rattus norvegicus). Both species are omnivorous and can breed year-round under favourable conditions. This review describes the occurrence of pathogens in rodents on specialist pig and chicken farms, which are usually closed units with a high level of bio-security. However, wild rodents may be difficult to exclude completely, even from these sites, and can pose a risk of introducing and spreading pathogens. This article reviews current knowledge regarding rodents as a hazard for spreading disease on farms. Most literature available regards zoonotic pathogens, while the literature regarding pathogens that cause disease in farm animals is more limited.

Characterization of extraintestinal pathogenic Escherichia coli isolated from captive wild felids with bacteremia.

PubMed

Carvalho, Vania M; Osugui, Lika; Setzer, Ariela P; Lopez, Rodrigo P G; Pestana de Castro, Antonio F; Irino, Kinue; Catão-Dias, José L

2012-09-01

Diseases caused by extraintestinal pathogenic Escherichia coli (ExPEC) in wild felids are rarely reported. Although urinary tract infections are infrequently reported in domestic cats, such infections when present are commonly caused by ExPEC. The present work characterized ExPEC strains isolated from 2 adult felines, a snow leopard (Panthera uncia) and a black leopard (Panthera pardus melas), that died from secondary bacteremia associated with urinary tract infections. Isolates from both animals were classified into the B2 phylogenetic group and expressed virulence genotypes that allowed them to cause severe disease. In addition, strains from the black leopard showed multidrug resistance.

Monitoring streams and stormwater ponds for early detection of oomycete plant pathogens in western Washington, a citizen science project

Treesearch

Marianne Elliott; Lucy Rollins; Gary Chastagner

2017-01-01

Sudden Oak Death (SOD) is the common name for a disease caused by Phytophthora ramorum (oomycetes), an invasive plant pathogen of regulatory concern. The nursery, timber, forest specialty product, and Christmas tree industries in Washington are at risk because of the spread of P. ramorum within nurseries and from nurseries into...

Multiple rare opportunistic and pathogenic fungi in persistent foot skin infection.

PubMed

Chan, Giek Far; Sinniah, Sivaranjini; Idris, Tengku Idzzan Nadzirah Tengku; Puad, Mohamad Safwan Ahmad; Abd Rahman, Ahmad Zuhairi

2013-03-01

Persistent superficial skin infection caused by multiple fungi is rarely reported. Recently, a number of fungi, both opportunistic and persistent in nature were isolated from the foot skin of a 24-year old male in Malaysia. The fungi were identified as Candida parapsilosis, Rhodotorula mucilaginosa, Phoma spp., Debaryomyces hansenii, Acremonium spp., Aureobasidium pullulans and Aspergillus spp., This is the first report on these opportunistic strains were co-isolated from a healthy individual who suffered from persistent foot skin infection which was diagnosed as athlete's foot for more than 12 years. Among the isolated fungi, C. parapsilosis has been an increasingly common cause of skin infections. R. mucilaginosa and D. hansenii were rarely reported in cases of skin infection. A. pullulans, an emerging fungal pathogen was also being isolated in this case. Interestingly, it was noted that C. parapsilosis, R. mucilaginosa, D. hansenii and A. pullulans are among the common halophiles and this suggests the association of halotolerant fungi in causing persistent superficial skin infection. This discovery will shed light on future research to explore on effective treatment for inhibition of pathogenic halophiles as well as to understand the interaction of multiple fungi in the progress of skin infection.

Elucidation of Bacterial Pneumonia-Causing Pathogens in Patients with Respiratory Viral Infection

PubMed Central

Jung, Hwa Sik; Kang, Byung Ju; Ra, Seung Won; Seo, Kwang Won; Jegal, Yangjin; Jun, Jae-Bum; Jung, Jiwon; Jeong, Joseph; Jeon, Hee-Jeong; Ahn, Jae-Sung

2017-01-01

Background Bacterial pneumonia occurring after respiratory viral infection is common. However, the predominant bacterial species causing pneumonia secondary to respiratory viral infections other than influenza remain unknown. The purpose of this study was to know whether the pathogens causing post-viral bacterial pneumonia vary according to the type of respiratory virus. Methods Study subjects were 5,298 patients, who underwent multiplex real-time polymerase chain reaction for simultaneous detection of respiratory viruses, among who visited the emergency department or outpatient clinic with respiratory symptoms at Ulsan University Hospital between April 2013 and March 2016. The patients' medical records were retrospectively reviewed. Results A total of 251 clinically significant bacteria were identified in 233 patients with post-viral bacterial pneumonia. Mycoplasma pneumoniae was the most frequent bacterium in patients aged <16 years, regardless of the preceding virus type (p=0.630). In patients aged ≥16 years, the isolated bacteria varied according to the preceding virus type. The major results were as follows (p<0.001): pneumonia in patients with influenza virus (type A/B), rhinovirus, and human metapneumovirus infections was caused by similar bacteria, and the findings indicated that Staphylococcus aureus pneumonia was very common in these patients. In contrast, coronavirus, parainfluenza virus, and respiratory syncytial virus infections were associated with pneumonia caused by gram-negative bacteria. Conclusion The pathogens causing post-viral bacterial pneumonia vary according to the type of preceding respiratory virus. This information could help in selecting empirical antibiotics in patients with post-viral pneumonia. PMID:28905531

The Candida Pathogenic Species Complex

PubMed Central

Turner, Siobhán A.; Butler, Geraldine

2014-01-01

Candida species are the most common causes of fungal infection. Approximately 90% of infections are caused by five species: Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, and Candida krusei. Three (C. albicans, C. tropicalis, and C. parapsilosis) belong to the CTG clade, in which the CTG codon is translated as serine and not leucine. C. albicans remains the most commonly isolated but is decreasing relative to the other species. The increasing incidence of C. glabrata is related to its reduced susceptibility to azole drugs. Genome analysis suggests that virulence in the CTG clade is associated with expansion of gene families, particularly of cell wall genes. Similar independent processes took place in the C. glabrata species group. Gene loss and expansion in an ancestor of C. glabrata may have resulted in preadaptations that enabled pathogenicity. PMID:25183855

Genetics and mapping of a new anthracnose resistance Locus in Andean common bean Paloma

USDA-ARS?s Scientific Manuscript database

The Andean cultivar Paloma is resistant to Mesoamerican and Andean races of Colletotrichum lindemuthianum, the fungal pathogen that causes the destructive anthracnose disease of common bean. Remarkably, Paloma is resistant to Mesoamerican races 2047 and 3481, which are among the most virulent races ...

Further characerization of the broad-spectrum anthraconse resistance in Andea common bean Amendoim Cavalo

USDA-ARS?s Scientific Manuscript database

Anthracnose is one of the most significant diseases of common bean (Phaseolus vulgaris) in temperate and subtropical bean production areas of the world. This disease is caused by Colletotrichum lindemuthianum, known for its extensive virulence diversity. Dozens of races of this pathogen have been ch...

Allovahlkampfia spelaea Causing Keratitis in Humans

PubMed Central

Tolba, Mohammed Essa Marghany; Huseein, Enas Abdelhameed Mahmoud; Farrag, Haiam Mohamed Mahmoud; Mohamed, Hanan El Deek; Kobayashi, Seiki; Suzuki, Jun; Ali, Tarek Ahmed Mohamed; Sugano, Sumio

2016-01-01

Background Free-living amoebae are present worldwide. They can survive in different environment causing human diseases in some instances. Acanthamoeba sp. is known for causing sight-threatening keratitis in humans. Free-living amoeba keratitis is more common in developing countries. Amoebae of family Vahlkampfiidae are rarely reported to cause such affections. A new genus, Allovahlkampfia spelaea was recently identified from caves with no data about pathogenicity in humans. We tried to identify the causative free-living amoeba in a case of keratitis in an Egyptian patient using morphological and molecular techniques. Methods Pathogenic amoebae were culture using monoxenic culture system. Identification through morphological features and 18S ribosomal RNA subunit DNA amplification and sequencing was done. Pathogenicity to laboratory rabbits and ability to produce keratitis were assessed experimentally. Results Allovahlkampfia spelaea was identified as a cause of human keratitis. Whole sequence of 18S ribosomal subunit DNA was sequenced and assembled. The Egyptian strain was closely related to SK1 strain isolated in Slovenia. The ability to induce keratitis was confirmed using animal model. Conclusions This the first time to report Allovahlkampfia spelaea as a human pathogen. Combining both molecular and morphological identification is critical to correctly diagnose amoebae causing keratitis in humans. Use of different pairs of primers and sequencing amplified DNA is needed to prevent misdiagnosis. PMID:27415799

Udder infections with Staphylococcus aureus, Streptococcus dysgalactiae, and Streptococcus uberis at calving in dairy herds with suboptimal udder health.

PubMed

Lundberg, Å; Nyman, A-K; Aspán, A; Börjesson, S; Unnerstad, H Ericsson; Waller, K Persson

2016-03-01

Udder infections with Staphylococcus aureus, Streptococcus dysgalactiae, and Streptococcus uberis are common causes of bovine mastitis. To study these pathogens in early lactation, a 12-mo longitudinal, observational study was carried out in 13 herds with suboptimal udder health. The aims of the study were to investigate the occurrence of these pathogens and to identify if presence of the 3 pathogens, and of genotypes within the pathogens, differed with respect to herd, season, and parity. Quarter milk samples, collected at calving and 4 d in milk (DIM), were cultured for the 3 pathogens. Genotyping of staphylococcal and streptococcal isolates was performed using spa typing and pulsed-field gel electrophoresis, respectively. For each of the 3 pathogens, cows with an udder infection at calving or 4 DIM were allocated to 1 of 4 infection types: cleared (pathogen present only at calving), persistent (pathogen present in the same quarter at calving and 4 DIM), new (pathogen present only at 4 DIM), or cleared/new (pathogen present in 1 quarter at calving and in another quarter at 4 DIM). Associations between season or parity and overall occurrence of pathogens or infection types were determined using univariable mixed-effect logistic-regression models and the Fisher's exact test, respectively. The most commonly occurring pathogen was Staph. aureus, followed by Strep. dysgalactiae and Strep. uberis. Persistent infections were the most common infection type among Staph. aureus-infected cows, whereas cleared infections were the most common among Strep. dysgalactiae- and Strep. uberis-positive cows. The proportion of cows with persistent Staph. aureus infections and the proportion of cows having a Strep. uberis infection at calving or 4 DIM were higher in the multiparous cows than in primiparous cows. Infections with Strep. dysgalactiae were less common during the early housing season than during the late housing or pasture seasons, whereas persistent Strep. uberis infections were less common during the pasture season than during the late housing season. The relative occurrence of the 3 pathogens, infection types of each pathogen, and genotype diversity of each pathogen throughout the year or in different seasons and parities varied among the herds, indicating that underlying factors predisposing for udder infections at calving differ between herds. Genotyping of bacterial isolates gave important insight into how such infection patterns differed within and between herds. These findings emphasize the need to choose preventive strategies for each individual herd. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Marker-assisted molecular profiling and RNA-Seq reveal a disease resistance cluster associated with Uromyces appendiculatus infection in common bean Phaseolus vulgaris L

USDA-ARS?s Scientific Manuscript database

Common bean (Phaseolus vulgaris L.) is an important legume, useful for its high protein and dietary fiber. The fungal pathogen Uromyces appendiculatus (Pers.) Unger can cause major loss in susceptible varieties of common bean. The Ur-3 locus provides race specific resistance to fungal rust along wit...

Detection of viruses and atypical bacteria associated with acute respiratory infection of children in Hubei, China.

PubMed

Wu, Zegang; Li, Yan; Gu, Jian; Zheng, Hongyun; Tong, Yongqing; Wu, Qing

2014-02-01

Acute respiratory infection is the major cause of disease and death in children, particularly in developing countries. However, the spectrum of pathogenic viruses and atypical bacteria that exist in many of these countries remains incompletely characterized. The aim of this study was to examine the spectrum of pathogenic viruses and atypical bacteria associated with acute respiratory infection in children under the age of 16. A total of 10 435 serum sera specimens were collected from hospitalized children presenting with acute respiratory infection symptoms. Indirect immunofluorescence assays were performed to detect immunoglobulin M antibodies against nine common pathogens: mycoplasma pneumonia, influenza virus B, respiratory syncytial virus, parainfluenza virus, adenovirus, influenza virus A, legionella pneumophila, coxiella burnetii and chamydophila pneumonia. Of the 10 435 specimens examined, 7046 tested positive for at least one pathogen. Among all of the tested pathogens, mycoplasma pneumonia had the highest detection rate (56.9%). Influenza virus A and influenza virus B epidemics occurred during both winter and summer. The detection rate of respiratory syncytial virus and adenovirus was higher in spring. Cases of mixed infection were more complex: 4136 specimens (39.6%) tested positive for ≥2 pathogens. There were statistically significant difference in detection rates of mycoplasma pneumonia, influenza virus B, respiratory syncytial virus, parainfluenza virus, adenovirus, influenza virus A, legionella pneumophila and chamydophila pneumonia among different age groups (P < 0.05). The most common pathogens causing acute respiratory infection among children in Hubei of China were mycoplasma pneumonia, influenza virus B and respiratory syncytial virus. The detection rates for each pathogen displayed specific seasonal and age group variations. © 2013 The Authors. Respirology © 2013 Asian Pacific Society of Respirology.

Uterine diseases in cattle after parturition

PubMed Central

Sheldon, I. Martin; Williams, Erin J.; Miller, Aleisha N.A.; Nash, Deborah M.; Herath, Shan

2008-01-01

Bacterial contamination of the uterine lumen is common in cattle after parturition, often leading to infection and uterine disease. Clinical disease can be diagnosed and scored by examination of the vaginal mucus, which reflects the presence of pathogenic bacteria such as Escherichia coli and Arcanobacterium pyogenes. Viruses may also cause uterine disease and bovine herpesvirus 4 (BoHV-4) is tropic for endometrial cells, causing a rapid cytopathic effect. The elimination of pathogens by the innate immune system is dependent on pattern recognition receptors binding pathogen-associated molecules. Uterine epithelial and stromal cells express receptors such as Toll-like Receptor 4 that binds E. coli lipopolysaccharide. The infertility associated with uterine disease is caused by damage to the endometrium and disruption of ovarian cyclic activity. Bacteria modulate endometrial prostaglandin secretion, and perturb ovarian follicle growth and function. Understanding the molecular basis of uterine disease will lead to novel approaches to treating infertility. PMID:18329302

The Insect Pathogens.

PubMed

Lovett, Brian; St Leger, Raymond J

2017-03-01

Fungi are the most common disease-causing agents of insects; aside from playing a crucial role in natural ecosystems, insect-killing fungi are being used as alternatives to chemical insecticides and as resources for biotechnology and pharmaceuticals. Some common experimentally tractable genera, such as Metarhizium spp., exemplify genetic diversity and dispersal because they contain numerous intraspecific variants with distinct environmental and insect host ranges. The availability of tools for molecular genetics and multiple sequenced genomes has made these fungi ideal experimental models for answering basic questions on the genetic and genomic processes behind adaptive phenotypes. For example, comparative genomics of entomopathogenic fungi has shown they exhibit diverse reproductive modes that often determine rates and patterns of genome evolution and are linked as cause or effect with pathogenic strategies. Fungal-insect pathogens represent lifestyle adaptations that evolved numerous times, and there are significant differences in host range and pathogenic strategies between the major groups. However, typically, spores landing on the cuticle produce appressoria and infection pegs that breach the cuticle using mechanical pressure and cuticle-degrading enzymes. Once inside the insect body cavity, fungal pathogens face a potent and comprehensively studied immune defense by which the host attempts to eliminate or reduce an infection. The Fungal Kingdom stands alone in the range, extent, and complexity of their manipulation of arthropod behavior. In part, this is because most only sporulate on cadavers, so they must ensure the dying host positions itself to allow efficient transmission.

Honey Bee Viruses in Wild Bees: Viral Prevalence, Loads, and Experimental Inoculation

PubMed Central

Dolezal, Adam G.; Hendrix, Stephen D.; Scavo, Nicole A.; Carrillo-Tripp, Jimena; Harris, Mary A.; Wheelock, M. Joseph; O’Neal, Matthew E.; Toth, Amy L.

2016-01-01

Evidence of inter-species pathogen transmission from managed to wild bees has sparked concern that emerging diseases could be causing or exacerbating wild bee declines. While some pathogens, like RNA viruses, have been found in pollen and wild bees, the threat these viruses pose to wild bees is largely unknown. Here, we tested 169 bees, representing 4 families and 8 genera, for five common honey bee (Apis mellifera) viruses, finding that more than 80% of wild bees harbored at least one virus. We also quantified virus titers in these bees, providing, for the first time, an assessment of viral load in a broad spectrum of wild bees. Although virus detection was very common, virus levels in the wild bees were minimal—similar to or lower than foraging honey bees and substantially lower than honey bees collected from hives. Furthermore, when we experimentally inoculated adults of two different bee species (Megachile rotundata and Colletes inaequalis) with a mixture of common viruses that is lethal to honey bees, we saw no effect on short term survival. Overall, we found that honey bee RNA viruses can be commonly detected at low levels in many wild bee species, but we found no evidence that these pathogens cause elevated short-term mortality effects. However, more work on these viruses is greatly needed to assess effects on additional bee species and life stages. PMID:27832169

Honey Bee Viruses in Wild Bees: Viral Prevalence, Loads, and Experimental Inoculation.

PubMed

Dolezal, Adam G; Hendrix, Stephen D; Scavo, Nicole A; Carrillo-Tripp, Jimena; Harris, Mary A; Wheelock, M Joseph; O'Neal, Matthew E; Toth, Amy L

2016-01-01

Evidence of inter-species pathogen transmission from managed to wild bees has sparked concern that emerging diseases could be causing or exacerbating wild bee declines. While some pathogens, like RNA viruses, have been found in pollen and wild bees, the threat these viruses pose to wild bees is largely unknown. Here, we tested 169 bees, representing 4 families and 8 genera, for five common honey bee (Apis mellifera) viruses, finding that more than 80% of wild bees harbored at least one virus. We also quantified virus titers in these bees, providing, for the first time, an assessment of viral load in a broad spectrum of wild bees. Although virus detection was very common, virus levels in the wild bees were minimal-similar to or lower than foraging honey bees and substantially lower than honey bees collected from hives. Furthermore, when we experimentally inoculated adults of two different bee species (Megachile rotundata and Colletes inaequalis) with a mixture of common viruses that is lethal to honey bees, we saw no effect on short term survival. Overall, we found that honey bee RNA viruses can be commonly detected at low levels in many wild bee species, but we found no evidence that these pathogens cause elevated short-term mortality effects. However, more work on these viruses is greatly needed to assess effects on additional bee species and life stages.

Common and uncommon pathogenic cascades in lysosomal storage diseases.

PubMed

Vitner, Einat B; Platt, Frances M; Futerman, Anthony H

2010-07-02

Lysosomal storage diseases (LSDs), of which about 50 are known, are caused by the defective activity of lysosomal proteins, resulting in accumulation of unmetabolized substrates. As a result, a variety of pathogenic cascades are activated such as altered calcium homeostasis, oxidative stress, inflammation, altered lipid trafficking, autophagy, endoplasmic reticulum stress, and autoimmune responses. Some of these pathways are common to many LSDs, whereas others are only altered in a subset of LSDs. We now review how these cascades impact upon LSD pathology and suggest how intervention in the pathways may lead to novel therapeutic approaches.

Postharvest salicylic acid treatment reduces storage rots in water-stressed but no unstressed sugarbeet roots

USDA-ARS?s Scientific Manuscript database

Exogenous application of salicylic acid (SA) reduces storage rots in a number of postharvest crops. SA’s ability to protect sugarbeet (Beta vulgaris L.) taproots from common storage rot pathogens, however, is unknown. To determine the potential of SA to reduce storage losses caused by three common...

Incidence and Trends of Infections with Pathogens Transmitted Commonly Through Food and the Effect of Increasing Use of Culture-Independent Diagnostic Tests on Surveillance - Foodborne Diseases Active Surveillance Network, 10 U.S. Sites, 2013-2016.

PubMed

Marder, Ellyn P; Cieslak, Paul R; Cronquist, Alicia B; Dunn, John; Lathrop, Sarah; Rabatsky-Ehr, Therese; Ryan, Patricia; Smith, Kirk; Tobin-D'Angelo, Melissa; Vugia, Duc J; Zansky, Shelley; Holt, Kristin G; Wolpert, Beverly J; Lynch, Michael; Tauxe, Robert; Geissler, Aimee L

2017-04-21

Foodborne diseases represent a substantial public health concern in the United States. CDC's Foodborne Diseases Active Surveillance Network (FoodNet) monitors cases reported from 10 U.S. sites* of laboratory-diagnosed infections caused by nine enteric pathogens commonly transmitted through food. This report describes preliminary surveillance data for 2016 on the nine pathogens and changes in incidences compared with 2013-2015. In 2016, FoodNet identified 24,029 infections, 5,512 hospitalizations, and 98 deaths caused by these pathogens. The use of culture-independent diagnostic tests (CIDTs) by clinical laboratories to detect enteric pathogens has been steadily increasing since FoodNet began surveying clinical laboratories in 2010 (1). CIDTs complicate the interpretation of FoodNet surveillance data because pathogen detection could be affected by changes in health care provider behaviors or laboratory testing practices (2). Health care providers might be more likely to order CIDTs because these tests are quicker and easier to use than traditional culture methods, a circumstance that could increase pathogen detection (3). Similarly, pathogen detection could also be increasing as clinical laboratories adopt DNA-based syndromic panels, which include pathogens not often included in routine stool culture (4,5). In addition, CIDTs do not yield isolates, which public health officials rely on to distinguish pathogen subtypes, determine antimicrobial resistance, monitor trends, and detect outbreaks. To obtain isolates for infections identified by CIDTs, laboratories must perform reflex culture † ; if clinical laboratories do not, the burden of culturing falls to state public health laboratories, which might not be able to absorb that burden as the adoption of these tests increases (2). Strategies are needed to preserve access to bacterial isolates for further characterization and to determine the effect of changing trends in testing practices on surveillance.

Ecological competition and the incidence of Acinetobacter baumannii bloodstream infections in a teaching hospital in Southeastern Brazil.

PubMed

Lastoria, Letícia Chamma; Caldeira, Sílvia Maria; Moreira, Rayana Gonçalves; Akazawa, Renata Tamie; Maion, Júlia Coutinho; Fortaleza, Carlos Magno Castelo Branco

2014-01-01

Recently, pathogen ecology has been recognized as an important epidemiological determinant of healthcare-associated infections (HAIs). Acinetobacter baumannii is one of the most important agents known to cause HAIs. It is widespread in healthcare settings and exhibits seasonal variations in incidence. Little is known about the impact of competition with other hospital pathogens on the incidence of A. baumannii infection. We conducted an ecological study, enrolling patients who presented with healthcare-associated bloodstream infections (HA-BSIs) from 2005 to 2010 at a 450-bed teaching hospital in Brazil. HA-BSIs were said to be present when bacteria or fungi were recovered from blood cultures collected at least three days after admission. Monthly incidence rates were calculated for all HA-BSIs (overall or caused by specific pathogens or groups of pathogens). Multivariate Poisson regression models were used to identify the impacts of the incidence of several pathogens on the incidence of A. baumannii. The overall incidence rate of HA-BSI caused by A. baumannii was 2.5 per 10,000 patient-days. In the multivariate analysis, the incidence of HA-BSI caused by A. baumannii was negatively associated with the incidence rates of HA-BSI due to Staphylococcus aureus (rate ratio [RR]=0.88; 95% confidence interval [CI]=0.80-0.97), Enterobacter spp. (RR=0.84; 95%CI=0.74-0.94) and a pool of less common gram-negative pathogens. Our results suggest that competition between pathogens influences the etiology of HA-BSIs. It would be beneficial to take these findings into account in infection control policies.

Developing Research in Infectious and Tropical Diseases in Africa: The Paradigm of Senegal.

PubMed

Sokhna, Cheikh; Gaye, Oumar; Doumbo, Ogobara

2017-08-15

Infectious diseases represent one of the greatest potential barriers to achievement of the third Sustainable Development Goals in African countries and around the world because they continue to pose major public health challenges. The surveillance of infectious diseases has recently assumed greater importance in most African countries, both because of the emergence of infectious diseases and because strains of pathogens that cause tuberculosis, malaria, cholera, dysentery, and pneumonia have developed resistance to common and inexpensive antimicrobial drugs. However, data on the pathogen-specific causes of infectious diseases are limited. Developing research in infectious and tropical diseases in Africa is urgently needed to better describe the distribution of pathogen-borne diseases and to know which pathogens actually cause fever. This research is critical for guiding treatment and policies in Africa. More effective diagnostics are also needed for these diseases, which often are misdiagnosed or diagnosed too late. A comprehensive review of this type of research is presented here. © 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.

Incidence, etiology, and symptomatology of upper respiratory illness in elite athletes.

PubMed

Spence, Luke; Brown, Wendy J; Pyne, David B; Nissen, Michael D; Sloots, Theo P; McCormack, Joseph G; Locke, A Simon; Fricker, Peter A

2007-04-01

Upper respiratory illness (URI) is the most common medical condition affecting elite athletes. The aims of this study were to identify and evaluate the incidence, pathogenic etiology, and symptomatology of acute URI during a 5-month training and competition period. Thirty-two elite and 31 recreationally competitive triathletes and cyclists, and 20 sedentary controls (age range 18.0-34.1 yr) participated in a prospective surveillance study. Nasopharyngeal and throat swabs were collected from subjects presenting with two or more defined upper respiratory symptoms. Swabs were analyzed using microscopy, culture, and PCR testing for typical and atypical respiratory pathogens. The Wisconsin Upper Respiratory Symptom Survey (WURSS-44) was used to assess symptomatology and functional impairment. Thirty-seven URI episodes were reported in 28 subjects. Incidence rate ratios for illness were higher in both the control subjects (1.93, 95% CI: 0.72-5.18) and elite athletes (4.50, 1.91-10.59) than in the recreationally competitive athletes. Infectious agents were identified in only 11 (two control, three recreationally competitive, and six elite) out of 37 illness episodes. Rhinovirus was the most common respiratory pathogen isolated. Symptom and functional impairment severity scores were higher in subjects with an infectious pathogen episode, particularly on illness days 3-4. The results confirm a higher rate of URI among elite athletes than recreationally competitive athletes during this training and competition season. However, because pathogens were isolated in fewer than 30% of URI cases, further study is required to uncover the causes of unidentified but symptomatic URI in athletes. Despite the common perception that all URI are infections, physicians should consider both infectious and noninfectious causes when athletes present with symptoms.

Genetic mechanisms of multidrug resistance among Klebsiella pneumoniae isolates from food-producing animals and humans in Lagos, Nigeria

USDA-ARS?s Scientific Manuscript database

Klebsiella pneumoniae is an opportunistic pathogen that commonly causes hospital and community acquired bacterial infections in humans. The emergence and rapid spread of multi- drug resistant (MDR) K. pneumoniae is causing drug therapy failure amid patients leading to poor antibiotic management glob...

Climate change and the ash dieback crisis

PubMed Central

Goberville, Eric; Hautekèete, Nina-Coralie; Kirby, Richard R.; Piquot, Yves; Luczak, Christophe; Beaugrand, Grégory

2016-01-01

Beyond the direct influence of climate change on species distribution and phenology, indirect effects may also arise from perturbations in species interactions. Infectious diseases are strong biotic forces that can precipitate population declines and lead to biodiversity loss. It has been shown in forest ecosystems worldwide that at least 10% of trees are vulnerable to extinction and pathogens are increasingly implicated. In Europe, the emerging ash dieback disease caused by the fungus Hymenoscyphus fraxineus, commonly called Chalara fraxinea, is causing a severe mortality of common ash trees (Fraxinus excelsior); this is raising concerns for the persistence of this widespread tree, which is both a key component of forest ecosystems and economically important for timber production. Here, we show how the pathogen and climate change may interact to affect the future spatial distribution of the common ash. Using two presence-only models, seven General Circulation Models and four emission scenarios, we show that climate change, by affecting the host and the pathogen separately, may uncouple their spatial distribution to create a mismatch in species interaction and so a lowering of disease transmission. Consequently, as climate change expands the ranges of both species polewards it may alleviate the ash dieback crisis in southern and occidental regions at the same time. PMID:27739483

Antibiotic resistance increases with local temperature

NASA Astrophysics Data System (ADS)

MacFadden, Derek R.; McGough, Sarah F.; Fisman, David; Santillana, Mauricio; Brownstein, John S.

2018-06-01

Bacteria that cause infections in humans can develop or acquire resistance to antibiotics commonly used against them1,2. Antimicrobial resistance (in bacteria and other microbes) causes significant morbidity worldwide, and some estimates indicate the attributable mortality could reach up to 10 million by 20502-4. Antibiotic resistance in bacteria is believed to develop largely under the selective pressure of antibiotic use; however, other factors may contribute to population level increases in antibiotic resistance1,2. We explored the role of climate (temperature) and additional factors on the distribution of antibiotic resistance across the United States, and here we show that increasing local temperature as well as population density are associated with increasing antibiotic resistance (percent resistant) in common pathogens. We found that an increase in temperature of 10 °C across regions was associated with an increases in antibiotic resistance of 4.2%, 2.2%, and 2.7% for the common pathogens Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus. The associations between temperature and antibiotic resistance in this ecological study are consistent across most classes of antibiotics and pathogens and may be strengthening over time. These findings suggest that current forecasts of the burden of antibiotic resistance could be significant underestimates in the face of a growing population and climate change4.

Convergent Evolution of Pathogen Effectors toward Reactive Oxygen Species Signaling Networks in Plants.

PubMed

Jwa, Nam-Soo; Hwang, Byung Kook

2017-01-01

Microbial pathogens have evolved protein effectors to promote virulence and cause disease in host plants. Pathogen effectors delivered into plant cells suppress plant immune responses and modulate host metabolism to support the infection processes of pathogens. Reactive oxygen species (ROS) act as cellular signaling molecules to trigger plant immune responses, such as pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity. In this review, we discuss recent insights into the molecular functions of pathogen effectors that target multiple steps in the ROS signaling pathway in plants. The perception of PAMPs by pattern recognition receptors leads to the rapid and strong production of ROS through activation of NADPH oxidase Respiratory Burst Oxidase Homologs (RBOHs) as well as peroxidases. Specific pathogen effectors directly or indirectly interact with plant nucleotide-binding leucine-rich repeat receptors to induce ROS production and the hypersensitive response in plant cells. By contrast, virulent pathogens possess effectors capable of suppressing plant ROS bursts in different ways during infection. PAMP-triggered ROS bursts are suppressed by pathogen effectors that target mitogen-activated protein kinase cascades. Moreover, pathogen effectors target vesicle trafficking or metabolic priming, leading to the suppression of ROS production. Secreted pathogen effectors block the metabolic coenzyme NADP-malic enzyme, inhibiting the transfer of electrons to the NADPH oxidases (RBOHs) responsible for ROS generation. Collectively, pathogen effectors may have evolved to converge on a common host protein network to suppress the common plant immune system, including the ROS burst and cell death response in plants.

Elucidation of Bacterial Pneumonia-Causing Pathogens in Patients with Respiratory Viral Infection.

PubMed

Jung, Hwa Sik; Kang, Byung Ju; Ra, Seung Won; Seo, Kwang Won; Jegal, Yangjin; Jun, Jae Bum; Jung, Jiwon; Jeong, Joseph; Jeon, Hee Jeong; Ahn, Jae Sung; Lee, Taehoon; Ahn, Jong Joon

2017-10-01

Bacterial pneumonia occurring after respiratory viral infection is common. However, the predominant bacterial species causing pneumonia secondary to respiratory viral infections other than influenza remain unknown. The purpose of this study was to know whether the pathogens causing post-viral bacterial pneumonia vary according to the type of respiratory virus. Study subjects were 5,298 patients, who underwent multiplex real-time polymerase chain reaction for simultaneous detection of respiratory viruses, among who visited the emergency department or outpatient clinic with respiratory symptoms at Ulsan University Hospital between April 2013 and March 2016. The patients' medical records were retrospectively reviewed. A total of 251 clinically significant bacteria were identified in 233 patients with post-viral bacterial pneumonia. Mycoplasma pneumoniae was the most frequent bacterium in patients aged <16 years, regardless of the preceding virus type (p=0.630). In patients aged ≥16 years, the isolated bacteria varied according to the preceding virus type. The major results were as follows (p<0.001): pneumonia in patients with influenza virus (type A/B), rhinovirus, and human metapneumovirus infections was caused by similar bacteria, and the findings indicated that Staphylococcus aureus pneumonia was very common in these patients. In contrast, coronavirus, parainfluenza virus, and respiratory syncytial virus infections were associated with pneumonia caused by gram-negative bacteria. The pathogens causing post-viral bacterial pneumonia vary according to the type of preceding respiratory virus. This information could help in selecting empirical antibiotics in patients with post-viral pneumonia. Copyright©2017. The Korean Academy of Tuberculosis and Respiratory Diseases

UroPathogenic Escherichia coli (UPEC) Infections: Virulence Factors, Bladder Responses, Antibiotic, and Non-antibiotic Antimicrobial Strategies

PubMed Central

Terlizzi, Maria E.; Gribaudo, Giorgio; Maffei, Massimo E.

2017-01-01

Urinary tract infections (UTIs) are one of the most common pathological conditions in both community and hospital settings. It has been estimated that about 150 million people worldwide develop UTI each year, with high social costs in terms of hospitalizations and medical expenses. Among the common uropathogens associated to UTIs development, UroPathogenic Escherichia coli (UPEC) is the primary cause. UPEC strains possess a plethora of both structural (as fimbriae, pili, curli, flagella) and secreted (toxins, iron-acquisition systems) virulence factors that contribute to their capacity to cause disease, although the ability to adhere to host epithelial cells in the urinary tract represents the most important determinant of pathogenicity. On the opposite side, the bladder epithelium shows a multifaceted array of host defenses including the urine flow and the secretion of antimicrobial substances, which represent useful tools to counteract bacterial infections. The fascinating and intricate dynamics between these players determine a complex interaction system that needs to be revealed. This review will focus on the most relevant components of UPEC arsenal of pathogenicity together with the major host responses to infection, the current approved treatment and the emergence of resistant UPEC strains, the vaccine strategies, the natural antimicrobial compounds along with innovative anti-adhesive and prophylactic approaches to prevent UTIs. PMID:28861072

Multistrain Infections with Lyme Borreliosis Pathogens in the Tick Vector.

PubMed

Durand, Jonas; Herrmann, Coralie; Genné, Dolores; Sarr, Anouk; Gern, Lise; Voordouw, Maarten J

2017-02-01

Mixed or multiple-strain infections are common in vector-borne diseases and have important implications for the epidemiology of these pathogens. Previous studies have mainly focused on interactions between pathogen strains in the vertebrate host, but little is known about what happens in the arthropod vector. Borrelia afzelii and Borrelia garinii are two species of spirochete bacteria that cause Lyme borreliosis in Europe and that share a tick vector, Ixodes ricinus Each of these two tick-borne pathogens consists of multiple strains that are often differentiated using the highly polymorphic ospC gene. For each Borrelia species, we studied the frequencies and abundances of the ospC strains in a wild population of I. ricinus ticks that had been sampled from the same field site over a period of 3 years. We used quantitative PCR (qPCR) and 454 sequencing to estimate the spirochete load and the strain diversity within each tick. For B. afzelii, there was a negative relationship between the two most common ospC strains, suggesting the presence of competitive interactions in the vertebrate host and possibly the tick vector. The flat relationship between total spirochete abundance and strain richness in the nymphal tick indicates that the mean abundance per strain decreases as the number of strains in the tick increases. Strains with the highest spirochete load in the nymphal tick were the most common strains in the tick population. The spirochete abundance in the nymphal tick appears to be an important life history trait that explains why some strains are more common than others in nature. Lyme borreliosis is the most common vector-borne disease in the Northern Hemisphere and is caused by spirochete bacteria that belong to the Borrelia burgdorferi sensu lato species complex. These tick-borne pathogens are transmitted among vertebrate hosts by hard ticks of the genus Ixodes Each Borrelia species can be further subdivided into genetically distinct strains. Multiple-strain infections are common in both the vertebrate host and the tick vector and can result in competitive interactions. To date, few studies on multiple-strain vector-borne pathogens have investigated patterns of cooccurrence and abundance in the arthropod vector. We demonstrate that the abundance of a given strain in the tick vector is negatively affected by the presence of coinfecting strains. In addition, our study suggests that the spirochete abundance in the tick is an important life history trait that can explain why some strains are more common in nature than others. Copyright © 2017 American Society for Microbiology.

Viable-but-Nonculturable Listeria monocytogenes and Salmonella enterica Serovar Thompson Induced by Chlorine Stress Remain Infectious.

PubMed

Highmore, Callum J; Warner, Jennifer C; Rothwell, Steve D; Wilks, Sandra A; Keevil, C William

2018-04-17

The microbiological safety of fresh produce is monitored almost exclusively by culture-based detection methods. However, bacterial food-borne pathogens are known to enter a viable-but-nonculturable (VBNC) state in response to environmental stresses such as chlorine, which is commonly used for fresh produce decontamination. Here, complete VBNC induction of green fluorescent protein-tagged Listeria monocytogenes and Salmonella enterica serovar Thompson was achieved by exposure to 12 and 3 ppm chlorine, respectively. The pathogens were subjected to chlorine washing following incubation on spinach leaves. Culture data revealed that total viable L. monocytogenes and Salmonella Thompson populations became VBNC by 50 and 100 ppm chlorine, respectively, while enumeration by direct viable counting found that chlorine caused a <1-log reduction in viability. The pathogenicity of chlorine-induced VBNC L. monocytogenes and Salmonella Thompson was assessed by using Caenorhabditis elegans Ingestion of VBNC pathogens by C. elegans resulted in a significant life span reduction ( P = 0.0064 and P < 0.0001), and no significant difference between the life span reductions caused by the VBNC and culturable L. monocytogenes treatments was observed. L. monocytogenes was visualized beyond the nematode intestinal lumen, indicating resuscitation and cell invasion. These data emphasize the risk that VBNC food-borne pathogens could pose to public health should they continue to go undetected. IMPORTANCE Many bacteria are known to enter a viable-but-nonculturable (VBNC) state in response to environmental stresses. VBNC cells cannot be detected by standard laboratory culture techniques, presenting a problem for the food industry, which uses these techniques to detect pathogen contaminants. This study found that chlorine, a sanitizer commonly used for fresh produce, induces a VBNC state in the food-borne pathogens Listeria monocytogenes and Salmonella enterica It was also found that chlorine is ineffective at killing total populations of the pathogens. A life span reduction was observed in Caenorhabditis elegans that ingested these VBNC pathogens, with VBNC L. monocytogenes as infectious as its culturable counterpart. These data show that VBNC food-borne pathogens can both be generated and avoid detection by industrial practices while potentially retaining the ability to cause disease. Copyright © 2018 Highmore et al.

Phage therapy for Florida corals?

USGS Publications Warehouse

Kellogg, Christina A.

2007-01-01

Coral disease is a major cause of reef decline in the Florida Keys. Bacterium has been defined as the most common pathogen (disease-causing organism). Although much is being done to catalog coral diseases, map their locations, determine the causes of disease, or measure the rates of coral demise, very little research has been directed toward actually preventing or eliminating the diseases affecting coral and coral reef decline.

Bacterial infections after pediatric heart transplantation: Epidemiology, risk factors and outcomes.

PubMed

Rostad, Christina A; Wehrheim, Karla; Kirklin, James K; Naftel, David; Pruitt, Elizabeth; Hoffman, Timothy M; L'Ecuyer, Thomas; Berkowitz, Katie; Mahle, William T; Scheel, Janet N

2017-09-01

Bacterial infections represent a major cause of morbidity and mortality in heart transplant recipients. However, data describing the epidemiology and outcomes of these infections in children are limited. We analyzed the Pediatric Heart Transplant Study database of patients transplanted between 1993 and 2014 to determine the etiologies, risk factors and outcomes of children with bacterial infections post-heart transplantation. Of 4,458 primary transplants in the database, there were 4,815 infections that required hospitalization or intravenous therapy, 2,047 (42.51%) of which were bacterial. The risk of bacterial infection was highest in the first month post-transplant, and the bloodstream was the most common site (24.82%). In the early post-transplant period (<30 days post-transplant), coagulase-negative staphylococci were the most common pathogens (16.97%), followed by Enterobacter sp (11.99%) and Pseudomonas sp (11.62%). In the late post-transplant period, community-acquired pathogens Streptococcus pneumoniae (6.27%) and Haemophilus influenzae (2.82%) were also commonly identified. Patients' characteristics independently associated with acquisition of bacterial infection included younger age (p < 0.0001) and ventilator (p < 0.0001) or extracorporeal membrane oxygenation (p = 0.03) use at time of transplant. Overall mortality post-bacterial infection was 33.78%, and previous cardiac surgery (p < 0.001) and multiple sites of infection (p = 0.004) were independent predictors of death. Bacteria were the most common causes of severe infections in pediatric heart transplant recipients and were associated with high mortality rates. The risk of acquiring a bacterial infection was highest in the first month post-transplant, and a large proportion of the infections were caused by multidrug-resistant pathogens. Copyright © 2017 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Evaluation of Presumably Disease Causing SCN1A Variants in a Cohort of Common Epilepsy Syndromes.

PubMed

Lal, Dennis; Reinthaler, Eva M; Dejanovic, Borislav; May, Patrick; Thiele, Holger; Lehesjoki, Anna-Elina; Schwarz, Günter; Riesch, Erik; Ikram, M Arfan; van Duijn, Cornelia M; Uitterlinden, Andre G; Hofman, Albert; Steinböck, Hannelore; Gruber-Sedlmayr, Ursula; Neophytou, Birgit; Zara, Federico; Hahn, Andreas; Gormley, Padhraig; Becker, Felicitas; Weber, Yvonne G; Cilio, Maria Roberta; Kunz, Wolfram S; Krause, Roland; Zimprich, Fritz; Lemke, Johannes R; Nürnberg, Peter; Sander, Thomas; Lerche, Holger; Neubauer, Bernd A

2016-01-01

The SCN1A gene, coding for the voltage-gated Na+ channel alpha subunit NaV1.1, is the clinically most relevant epilepsy gene. With the advent of high-throughput next-generation sequencing, clinical laboratories are generating an ever-increasing catalogue of SCN1A variants. Variants are more likely to be classified as pathogenic if they have already been identified previously in a patient with epilepsy. Here, we critically re-evaluate the pathogenicity of this class of variants in a cohort of patients with common epilepsy syndromes and subsequently ask whether a significant fraction of benign variants have been misclassified as pathogenic. We screened a discovery cohort of 448 patients with a broad range of common genetic epilepsies and 734 controls for previously reported SCN1A mutations that were assumed to be disease causing. We re-evaluated the evidence for pathogenicity of the identified variants using in silico predictions, segregation, original reports, available functional data and assessment of allele frequencies in healthy individuals as well as in a follow up cohort of 777 patients. We identified 8 known missense mutations, previously reported as pathogenic, in a total of 17 unrelated epilepsy patients (17/448; 3.80%). Our re-evaluation indicates that 7 out of these 8 variants (p.R27T; p.R28C; p.R542Q; p.R604H; p.T1250M; p.E1308D; p.R1928G; NP_001159435.1) are not pathogenic. Only the p.T1174S mutation may be considered as a genetic risk factor for epilepsy of small effect size based on the enrichment in patients (P = 6.60 x 10-4; OR = 0.32, fishers exact test), previous functional studies but incomplete penetrance. Thus, incorporation of previous studies in genetic counseling of SCN1A sequencing results is challenging and may produce incorrect conclusions.

Evaluation of Presumably Disease Causing SCN1A Variants in a Cohort of Common Epilepsy Syndromes

PubMed Central

May, Patrick; Thiele, Holger; Lehesjoki, Anna-Elina; Schwarz, Günter; Riesch, Erik; Ikram, M. Arfan; van Duijn, Cornelia M.; Uitterlinden, Andre G.; Hofman, Albert; Steinböck, Hannelore; Gruber-Sedlmayr, Ursula; Neophytou, Birgit; Zara, Federico; Hahn, Andreas; Gormley, Padhraig; Becker, Felicitas; Weber, Yvonne G.; Cilio, Maria Roberta; Kunz, Wolfram S.; Krause, Roland; Zimprich, Fritz; Lemke, Johannes R.; Nürnberg, Peter; Sander, Thomas; Lerche, Holger; Neubauer, Bernd A.

2016-01-01

Objective The SCN1A gene, coding for the voltage-gated Na+ channel alpha subunit NaV1.1, is the clinically most relevant epilepsy gene. With the advent of high-throughput next-generation sequencing, clinical laboratories are generating an ever-increasing catalogue of SCN1A variants. Variants are more likely to be classified as pathogenic if they have already been identified previously in a patient with epilepsy. Here, we critically re-evaluate the pathogenicity of this class of variants in a cohort of patients with common epilepsy syndromes and subsequently ask whether a significant fraction of benign variants have been misclassified as pathogenic. Methods We screened a discovery cohort of 448 patients with a broad range of common genetic epilepsies and 734 controls for previously reported SCN1A mutations that were assumed to be disease causing. We re-evaluated the evidence for pathogenicity of the identified variants using in silico predictions, segregation, original reports, available functional data and assessment of allele frequencies in healthy individuals as well as in a follow up cohort of 777 patients. Results and Interpretation We identified 8 known missense mutations, previously reported as pathogenic, in a total of 17 unrelated epilepsy patients (17/448; 3.80%). Our re-evaluation indicates that 7 out of these 8 variants (p.R27T; p.R28C; p.R542Q; p.R604H; p.T1250M; p.E1308D; p.R1928G; NP_001159435.1) are not pathogenic. Only the p.T1174S mutation may be considered as a genetic risk factor for epilepsy of small effect size based on the enrichment in patients (P = 6.60 x 10−4; OR = 0.32, fishers exact test), previous functional studies but incomplete penetrance. Thus, incorporation of previous studies in genetic counseling of SCN1A sequencing results is challenging and may produce incorrect conclusions. PMID:26990884

Actinobaculum schaalii, a Common Uropathogen in Elderly Patients, Denmark

PubMed Central

Jensen, Anders; Hansen, Thomas M.; Søby, Karen M.; Prag, Jørgen

2010-01-01

Actinobaculum schaalii can cause urinary tract infections and septicemia but is difficult to identify by cultivation. To obtain a fast diagnosis and identify A. schaalii, we developed a TaqMan real-time quantitative PCR. Routine urine samples were obtained from 177 hospitalized patients and 75 outpatients in Viborg County, Denmark, in 2008–2009. The PCR detected A. schaalii in 22% of samples from patients >60 years of age. This assay showed that A. schaalii is more common than implied by routine cultivation. In 90% of PCR-positive urine samples, other common uropathogens were identified. This finding suggests that A. schaalii is a common, undetected, bacterial pathogen. Our results suggest that A. schaalii may be a more common pathogen than previously thought, especially in patients with unexplained chronic urinary tract infections, who are often treated with trimethoprim or ciprofloxacin, to which A. schaalii is resistant. PMID:20031046

T-Cell response profiling to biological threat agents including the SARS coronavirus.

PubMed

Gioia, C; Horejsh, D; Agrati, C; Martini, F; Capobianchi, M R; Ippolito, G; Poccia, F

2005-01-01

The emergence of pathogens such as SARS and the increased threat of bioterrorism has stimulated the development of novel diagnostic assays for differential diagnosis. Rather than focusing on the detection of an individual pathogen component, we have developed a T cell profiling system to monitor responses to the pathogens in an array format. Using a matrix of antigens specific for different pathogens, a specific T cell profile was generated for each individual by monitoring the intracellular production of interferon-gamma by flow cytometry. This assay allows for the testing of multiple proteins or peptides at a single time and provides a quantitative and phenotypic assessment of CD4(+) and CD8(+) responding cells. We present profiling examples for several positive individuals, including those vaccinated with the smallpox and anthrax vaccines. We also show antigen optimization for the SARS-hCoV, as studies revealed that these proteins contain peptides which cross-react with more common coronaviruses, a cause of the common cold. The T cell array is an early and sensitive multiplex measure of active infection, exposure to a pathogen, or effective, recent vaccination.

Lactoferrin for prevention of common viral infections.

PubMed

Wakabayashi, Hiroyuki; Oda, Hirotsugu; Yamauchi, Koji; Abe, Fumiaki

2014-11-01

Although lactoferrin has many biological functions, the host-protective effects against pathogenic microorganisms including bacteria, fungi, and viruses are regarded as one of the most important. Here, we review research on the protective role of lactoferrin administration against common viral infections. Many studies have shown the in vitro antiviral activity of lactoferrin against viral pathogens that cause common infections such as the common cold, influenza, gastroenteritis, summer cold, and herpes, where lactoferrin inhibits mainly viral attachment to the target cells. Recently, studies indicating the in vivo protective effects of lactoferrin by oral administration against common viral infections have been increasing. For instance, norovirus is an extremely important emerging human pathogen that causes a majority of gastroenteritis outbreaks worldwide that may be a target candidate for lactoferrin. Lactoferrin consumption reduced the incidence of noroviral gastroenteritis in children and a similar effect was observed in a wide range of ages in a preliminary survey. A recent in vitro study reported that lactoferrin inhibits both cellular attachment of the murine norovirus, a virus closely-related to the human norovirus, and viral replication in the cells by inducing antiviral cytokines interferon (IFN)-α/β. Lactoferrin administration also enhances NK cell activity and Th1 cytokine responses, which lead to protection against viral infections. In conclusion, lactoferrin consumption may protect the host from viral infections through inhibiting the attachment of a virus to the cells, replication of the virus in the cells, and enhancement of systemic immune functions. Copyright © 2014 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Using participatory epidemiology to assess factors contributing to common enteric pathogens in Ontario: results from a workshop held at the Ontario Veterinary College, University of Guelph, Ontario

PubMed Central

2014-01-01

Background Common enteric pathogens that cause gastrointestinal illness are transmitted to humans through food, water or direct contact. This poses a significant concern to public health as enteric pathogens can cause disease in a large number of people, and cost a substantial amount to treat and prevent. In order to gain a better understanding of the occurrence of enteric disease in Ontario, this study explored public health professionals’ perceptions of major contributing factors for common enteric pathogens. Methods A case study was conducted as part of a two week training workshop in Participatory Epidemiology held at the Ontario Veterinary College, University of Guelph, in May 2013. Eight semi-structured interviews and four focus groups were conducted with representatives from the Public Health Agency of Canada, the University of Guelph, and three health regions in Southern Ontario. Written notes and pictures captured the qualitative information provided. Results were then analyzed using the mixed methods techniques of triangulation, convergence, and paradox. Results A total of fifty factors that contribute to enteric disease were identified across all interviews and focus groups. These contributing factors were grouped into key themes (travel, food handling, industry (farm-to-fork), water, geography, demographics, and behaviours) and were categorized as either a risk factor or susceptibility factor. Informants emphasized the complex relationships between the identified factors, and highlighted why these complexities make it difficult to determine where and how a person most likely acquired an enteric pathogen. Workshop participants observed differences in the type and quality of information collected during interviews and focus groups; we hypothesize that this may be attributed to the dynamics between group members (i.e. focus group discussions) as opposed to one-on-one interviews. Conclusions The information gathered will serve as a starting point to further explore contributing factors for common enteric pathogens. The identified complexities would be best explored by conducting additional surveillance, as well as interviews and focus groups with a more diverse group of stakeholders. This type of qualitative study can enhance knowledge of enteric pathogen surveillance and contribute to the development of resources and initiatives to holistically address the occurrence of gastrointestinal illness. PMID:24767430

Genome-Wide Linkage and Association Mapping of Halo Blight Resistance in Common Bean to Race 6 of the Globally Important Bacterial Pathogen

PubMed Central

Tock, Andrew J.; Fourie, Deidré; Walley, Peter G.; Holub, Eric B.; Soler, Alvaro; Cichy, Karen A.; Pastor-Corrales, Marcial A.; Song, Qijian; Porch, Timothy G.; Hart, John P.; Vasconcellos, Renato C. C.; Vicente, Joana G.; Barker, Guy C.; Miklas, Phillip N.

2017-01-01

Pseudomonas syringae pv. phaseolicola (Psph) Race 6 is a globally prevalent and broadly virulent bacterial pathogen with devastating impact causing halo blight of common bean (Phaseolus vulgaris L.). Common bean lines PI 150414 and CAL 143 are known sources of resistance against this pathogen. We constructed high-resolution linkage maps for three recombinant inbred populations to map resistance to Psph Race 6 derived from the two common bean lines. This was complemented with a genome-wide association study (GWAS) of Race 6 resistance in an Andean Diversity Panel of common bean. Race 6 resistance from PI 150414 maps to a single major-effect quantitative trait locus (QTL; HB4.2) on chromosome Pv04 and confers broad-spectrum resistance to eight other races of the pathogen. Resistance segregating in a Rojo × CAL 143 population maps to five chromosome arms and includes HB4.2. GWAS detected one QTL (HB5.1) on chromosome Pv05 for resistance to Race 6 with significant influence on seed yield. The same HB5.1 QTL, found in both Canadian Wonder × PI 150414 and Rojo × CAL 143 populations, was effective against Race 6 but lacks broad resistance. This study provides evidence for marker-assisted breeding for more durable halo blight control in common bean by combining alleles of race-nonspecific resistance (HB4.2 from PI 150414) and race-specific resistance (HB5.1 from cv. Rojo). PMID:28736566

Relationship with original pathogen in recurrence of acute otitis media after completion of amoxicillin/clavulanate: bacterial relapse or new pathogen.

PubMed

Kaur, Ravinder; Casey, Janet R; Pichichero, Michael E

2013-11-01

We sought to determine whether recurrent acute otitis media (rAOM) occurring within 30 days of amoxicillin/clavulanate treatment was caused by bacterial relapse or new pathogens. Pneumococcal conjugate vaccinated children, age 6-36 months, enrolled in a prospective, longitudinal study experiencing rAOM<1 month after completing amoxicillin/clavulanate therapy were studied. AOM episodes occurred between June 2006 and November 2012. Multilocus sequence typing was used to genotype isolates. Sixty-six children were in the study cohort; 63 otopathogens were recovered from middle ear fluid after tympanocentesis. Nontypeable Haemophilus influenzae (NTHi) accounted for 47% of initial AOMs versus 15% by Streptococcus pneumoniae (Spn), P<0.0001. NTHi accounted for 42% of rAOM versus 24% by Spn (P value=0.04). NTHi was the main otopathogen that caused true bacteriologic relapses (77%). β-lactamase-producing NTHi and penicillin nonsusceptible Spn were not more common in rAOM than initial AOM infections. Among 21 paired (initial and rAOM events) NTHi isolates genotyped, 13 (61.9%) were the same organism; 1 of 9 (11.1%) of paired Spn isolates was the same (P value=0.017). rAOM occurring within a week of stopping amoxicillin/clavulanate was a different pathogen in 21% of cases, 8-14 days later in 33%, 15-21 days in 41% and 22-30 days in 57% (P=0.04). In amoxicillin/clavulanate-treated children, NTHi was the main otopathogen that caused true bacteriologic relapses. New pathogens causing rAOM versus persistence of the initial pathogen significantly increased week to week. Neither relapses nor new infections were caused more frequently by β-lactamase producing NTHi or penicillin nonsusceptible Spn.

Microbial pathogens trigger host DNA double-strand breaks whose abundance is reduced by plant defense responses.

PubMed

Song, Junqi; Bent, Andrew F

2014-04-01

Immune responses and DNA damage repair are two fundamental processes that have been characterized extensively, but the links between them remain largely unknown. We report that multiple bacterial, fungal and oomycete plant pathogen species induce double-strand breaks (DSBs) in host plant DNA. DNA damage detected by histone γ-H2AX abundance or DNA comet assays arose hours before the disease-associated necrosis caused by virulent Pseudomonas syringae pv. tomato. Necrosis-inducing paraquat did not cause detectable DSBs at similar stages after application. Non-pathogenic E. coli and Pseudomonas fluorescens bacteria also did not induce DSBs. Elevation of reactive oxygen species (ROS) is common during plant immune responses, ROS are known DNA damaging agents, and the infection-induced host ROS burst has been implicated as a cause of host DNA damage in animal studies. However, we found that DSB formation in Arabidopsis in response to P. syringae infection still occurs in the absence of the infection-associated oxidative burst mediated by AtrbohD and AtrbohF. Plant MAMP receptor stimulation or application of defense-activating salicylic acid or jasmonic acid failed to induce a detectable level of DSBs in the absence of introduced pathogens, further suggesting that pathogen activities beyond host defense activation cause infection-induced DNA damage. The abundance of infection-induced DSBs was reduced by salicylic acid and NPR1-mediated defenses, and by certain R gene-mediated defenses. Infection-induced formation of γ-H2AX still occurred in Arabidopsis atr/atm double mutants, suggesting the presence of an alternative mediator of pathogen-induced H2AX phosphorylation. In summary, pathogenic microorganisms can induce plant DNA damage. Plant defense mechanisms help to suppress rather than promote this damage, thereby contributing to the maintenance of genome integrity in somatic tissues.

Multiplex identification of sepsis-causing Gram-negative pathogens from the plasma of infected blood.

PubMed

Chung, Boram; Park, Chulmin; Cho, Sung-Yeon; Shin, Juyoun; Shin, Sun; Yim, Seon-Hee; Lee, Dong-Gun; Chung, Yeun-Jung

2018-02-01

Early and accurate detection of bacterial pathogens in the blood is the most crucial step for sepsis management. Gram-negative bacteria are the most common organisms causing severe sepsis and responsible for high morbidity and mortality. We aimed to develop a method for rapid multiplex identification of clinically important Gram-negative pathogens and also validated whether our system can identify Gram-negative pathogens with the cell-free plasm DNA from infected blood. We designed five MLPA probe sets targeting the genes specific to major Gram-negative pathogens (uidA and lacY for E. coli, ompA for A. baumannii, phoE for K. pneumoniae, and ecfX for P. aeruginosa) and one set targeting the CTX-M group 1 to identify the ESBL producing Gram-negative pathogens. All six target-specific peaks were clearly separated without any non-specific peaks in a multiplex reaction condition. The minimum detection limit was 100 fg of pathogen DNA. When we tested 28 Gram-negative clinical isolates, all of them were successfully identified without any non-specific peaks. To evaluate the clinical applicability, we tested seven blood samples from febrile patients. Three blood culture positive cases showed E. coli specific peaks, while no peak was detected in the other four culture negative samples. This technology can be useful for detection of major sepsis-causing, drug-resistant Gram-negative pathogens and also the major ESBL producing Gram-negatives from the blood of sepsis patients in a clinical setting. This system can help early initiation of effective antimicrobial treatment against Gram-negative pathogens for sepsis patients, which is very crucial for better treatment outcomes. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Haemorrhagic septicaemia in a pig caused by extraintestinal pathogenic Escherichia coli (ExPEC) as a differential diagnosis in classical swine fever--case report and review of the literature].

PubMed

Reiner, Gerald; von Berg, Stephan; Hillen, Sonja; Clemens, Nina; Huisinger, Maike; Burkhardt, Eberhard; Weiss, Reinhardt; Reinacher, Manfred

2010-01-01

Domestic pig herds in some regions of Germany are permanently threatened by Classical Swine Fever. In the case of suspicion, a series of infectious and non infectious causes has to be excluded. The present paper describes a case of Escherichia coli septicaemia, with clinical and pathological symptoms that could not be differentiated from European or African Swine Fever. The E. coli strain could not be classified by standard serotyping. Virulence factors common for ETEC (enterotoxic E. coli) or EDEC (edema-disease E. coli) were not detected. Instead, we found P-fimbriae and aerobactin, thus characterising this strain as an extraintestinal pathogenic strain. Such strains have sporadicly been reported as the cause of septicaemia in piglets or weaners, but the present case is the first report of an E. coli-associated septicaemia in an adult pig. This case shows that extraintestinal pathogenic E. coli can be the cause of severe septicaemia and haemorrhagia. They thus have to be considered as a further differential diagnosis in swine fever.

In vitro synergistic effects of fisetin and norfloxacin against aquatic isolates of Serratia marcescens.

PubMed

Dong, Jing; Ruan, Jing; Xu, Ning; Yang, Yibin; Ai, Xiaohui

2016-01-01

Serratia marcescens is a common pathogenic bacterium that can cause infections in both humans and animals. It can cause a range of diseases, from slight wound infections to life-threatening bacteraemia and pneumonia. The emergence of antimicrobial resistance has limited the treatment of the diseases caused by the bacterium to a great extent. Consequently, there is an urgent need to develop novel antimicrobial strategies against this pathogen. Synergistic strategy is a new approach to treat the infections caused by drug-resistant bacteria. In this paper, we isolated and identified the first multi-resistant pathogenic Serratia marcescens strain from diseased soft-shelled turtles (Pelodiscus sinensis) in China. We then performed a checkerboard assay; the results showed that out of 10 tested natural products fisetin had synergistic effects against S. marcescens when combined with norfloxacin. The time-kill curve assay further confirmed the results of the checkerboard assay. We found that this novel synergistic effect could significantly reduce the dosage of norfloxacin against S. marcescens. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Titin Mutations in iPS cells Define Sarcomere Insufficiency as a Cause of Dilated Cardiomyopathy

PubMed Central

Hinson, John T.; Chopra, Anant; Nafissi, Navid; Polacheck, William J.; Benson, Craig C.; Swist, Sandra; Gorham, Joshua; Yang, Luhan; Schafer, Sebastian; Sheng, Calvin C.; Haghighi, Alireza; Homsy, Jason; Hubner, Norbert; Church, George; Cook, Stuart A.; Linke, Wolfgang A.; Chen, Christopher S.; Seidman, J. G.; Seidman, Christine E.

2015-01-01

Human mutations that truncate the massive sarcomere protein titin (TTNtv) are the most common genetic cause for dilated cardiomyopathy (DCM), a major cause of heart failure and premature death. Here we show that cardiac microtissues engineered from human induced pluripotent stem (iPS) cells are a powerful system for evaluating the pathogenicity of titin gene variants. We found that certain missense mutations, like TTNtv, diminish contractile performance and are pathogenic. By combining functional analyses with RNAseq, we explain why truncations in the A-band domain of TTN cause DCM while truncations in the I-band are better tolerated. Finally, we demonstrate that mutant titin protein in iPS-cardiomyocytes results in sarcomere insufficiency, impaired responses to mechanical and β-adrenergic stress, and attenuated growth factor and cell signaling activation. Our findings indicate that titin mutations cause DCM by disrupting critical linkages between sarcomerogenesis and adaptive remodelling. PMID:26315439

Convergent Evolution of Pathogen Effectors toward Reactive Oxygen Species Signaling Networks in Plants

PubMed Central

Jwa, Nam-Soo; Hwang, Byung Kook

2017-01-01

Microbial pathogens have evolved protein effectors to promote virulence and cause disease in host plants. Pathogen effectors delivered into plant cells suppress plant immune responses and modulate host metabolism to support the infection processes of pathogens. Reactive oxygen species (ROS) act as cellular signaling molecules to trigger plant immune responses, such as pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity. In this review, we discuss recent insights into the molecular functions of pathogen effectors that target multiple steps in the ROS signaling pathway in plants. The perception of PAMPs by pattern recognition receptors leads to the rapid and strong production of ROS through activation of NADPH oxidase Respiratory Burst Oxidase Homologs (RBOHs) as well as peroxidases. Specific pathogen effectors directly or indirectly interact with plant nucleotide-binding leucine-rich repeat receptors to induce ROS production and the hypersensitive response in plant cells. By contrast, virulent pathogens possess effectors capable of suppressing plant ROS bursts in different ways during infection. PAMP-triggered ROS bursts are suppressed by pathogen effectors that target mitogen-activated protein kinase cascades. Moreover, pathogen effectors target vesicle trafficking or metabolic priming, leading to the suppression of ROS production. Secreted pathogen effectors block the metabolic coenzyme NADP-malic enzyme, inhibiting the transfer of electrons to the NADPH oxidases (RBOHs) responsible for ROS generation. Collectively, pathogen effectors may have evolved to converge on a common host protein network to suppress the common plant immune system, including the ROS burst and cell death response in plants. PMID:29033963

Antibiotic resistance pattern and empirical therapy for urinary tract infections in children.

PubMed

Al-Harthi, Abdulla A; Al-Fifi, Suliman H

2008-06-01

To study the type of bacterial pathogen causing urinary tract infection in children at Aseer Central Hospital, southwestern Saudi Arabia, and their antimicrobial resistance patterns. A retrospective study of all the urine cultures carried out on children in the period from January 2003 to December 2006, for a total of 4 years were reviewed at the bacteriology laboratory, Aseer Central Hospital, southwestern region of Saudi Arabia. Their antimicrobial resistances as well as sensitivities were also analyzed. A total of 464 urine cultures were identified. Escherichia coli constitutes the most common pathogen isolated (37.3%), followed by Klebsiella (16.4%) and Pseudomonas species (15.7%). In general, there was a significant increase in the resistance rates of different bacterial pathogens to different antibiotics. In spite of an increase in the resistance rates of bacterial pathogens causing UTI, ceftriaxone, imipenem, and to some extent Azactam are appropriate for initial empirical intravenous therapy in UTI. In patients with uncomplicated UTI not requiring hospitalization, Nalidixic acid, and Nitrofurantoin can be used as oral treatment.

Epidemiological and microbiological characteristics of culture-proven acute otitis media in Taiwanese children.

PubMed

Chiu, Nan-Chang; Lin, Hsin-Yi; Hsu, Chyong-Hsin; Huang, Fu-Yuan; Lee, Kuo-Sheng; Chi, Hsin

2012-10-01

Acute otitis media (AOM) is one of the most common diseases in children. Here, we describe the epidemiological and microbiological characteristics of AOM in Taiwanese children over a 10-year period. We retrospectively enrolled pediatric patients with culture-proven AOM who were treated at Mackay Memorial Hospital, Taipei between 1999-2008. The data include demographic characteristics, clinical history, and microbiological characteristics. Six hundred and fourteen patients were included. The male:female ratio was 1.4 (p<0.001). Greater than three-fourths of the patients (476 [77.5%]) were < 5 years of age, and most patients were 1-2 years of age. The most common isolated pathogen was Streptococcus pneumoniae (419 patients [68.2%]), followed by nontypeable Haemophilus influenzae (NTHi; 118 patients [19.2%]). The distributions of age, gender, use of tympanocentesis, history of previous AOM, and use of antibiotic between patients infected with the two pathogens were not significantly different. However, the number of patients with AOM caused by S. pneumoniae, but not NTHi, decreased during the study period (p=0.004). Three hundred and eighty-seven children (63.0%) with AOM developed spontaneous otorrhea. Compared with patients who underwent tympanocentesis, those with spontaneous otorrhea were younger (27.0±16.4 vs. 31.1±15.2 months of age, p=0.004), more likely to have a previous history of AOM (p=0.019), and more likely to receive more antibiotics (p=0.012). The third most common pathogen was S. pyogenes (25 patients [4.1%]). S. pyogenes occurred more often in children > 5 years of age and was associated with spontaneous otorrhea (p<0.001). S. pneumoniae and NTHi are common causes of culture-confirmed AOM in Taiwanese children. Although S. pyogenes is not as common, it usually causes AOM in children > 5 years of age and is associated with spontaneous otorrhea. Copyright © 2012. Published by Elsevier B.V.

Mitochondrial DNA disease—molecular insights and potential routes to a cure

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

Russell, Oliver; Turnbull, Doug, E-mail: doug.turnbull@newcastle.ac.uk

2014-07-01

Mitochondrial DNA diseases are common neurological conditions caused by mutations in the mitochondrial genome or nuclear genes responsible for its maintenance. Current treatments for these disorders are focussed on the management of the symptoms, rather than the correction of biochemical defects caused by the mutation. This review focuses on the molecular effects of mutations, the symptoms they cause and current work focusing on the development of targeted treatments for mitochondrial DNA disease. - Highlights: • We discuss several common disease causing mtDNA mutations. • We highlight recent work linking pathogenicity to deletion size and heteroplasmy. • We discuss recent advancesmore » in the development of targeted mtDNA disease treatments.« less

Enterococci in the Environment

EPA Science Inventory

Enterococci are common, commensal members of gut communities in mammals and birds, yet they are also opportunistic pathogens that cause millions of human and animal infections annually. Because they are shed in human and animal feces, are readily culturable, and predict human hea...

Heart failure and sudden cardiac death in heritable thoracic aortic disease caused by pathogenic variants in the SMAD3 gene.

PubMed

Backer, Julie De; Braverman, Alan C

2018-05-01

Predominant cardiovascular manifestations in the spectrum of Heritable Thoracic Aortic Disease include by default aortic root aneurysms- and dissections, which may be associated with aortic valve disease. Mitral- and tricuspid valve prolapse are other commonly recognized features. Myocardial disease, characterized by heart failure and/or malignant arrhythmias has been reported in humans and in animal models harboring pathogenic variants in the Fibrillin1 gene. Description of clinical history of three cases from one family in Ghent (Belgium) and one family in St. Louis (US). We report on three cases from two families presenting end-stage heart failure (in two) and lethal arrhythmias associated with moderate left ventricular dilatation (in one). All three cases harbor a pathogenic variant in the SMAD3 gene, known to cause aneurysm osteoarthritis syndrome, Loeys-Dietz syndrome type 3 or isolated Heritable Thoracic Aortic Disease. These unusual presentations warrant awareness for myocardial disease in patients harboring pathogenic variants in genes causing Heritable Thoracic Aortic Disease and indicate the need for prospective studies in larger cohorts. © 2018 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.

Leptospiral uveitis - there is more to it than meets the eye!

PubMed

Verma, A; Stevenson, B

2012-09-01

Leptospirosis, caused by pathogenic species of genus Leptospira, is a highly prevalent zoonotic disease throughout many parts of the world, and an important emerging disease within the United States. Uveitis is a common complication of systemic infection in humans. A similar condition in horses is characterized by recurrent bouts of inflammation. In this article, we review advances in our understanding of leptospiral uveitis and its pathogenic mechanisms. © 2012 Blackwell Verlag GmbH.

One Health and Food-Borne Disease: Salmonella Transmission between Humans, Animals, and Plants.

PubMed

Silva, Claudia; Calva, Edmundo; Maloy, Stanley

2014-02-01

There are >2,600 recognized serovars of Salmonella enterica. Many of these Salmonella serovars have a broad host range and can infect a wide variety of animals, including mammals, birds, reptiles, amphibians, fish, and insects. In addition, Salmonella can grow in plants and can survive in protozoa, soil, and water. Hence, broad-host-range Salmonella can be transmitted via feces from wild animals, farm animals, and pets or by consumption of a wide variety of common foods: poultry, beef, pork, eggs, milk, fruit, vegetables, spices, and nuts. Broad-host-range Salmonella pathogens typically cause gastroenteritis in humans. Some Salmonella serovars have a more restricted host range that is associated with changes in the virulence plasmid pSV, accumulation of pseudogenes, and chromosome rearrangements. These changes in host-restricted Salmonella alter pathogen-host interactions such that host-restricted Salmonella organisms commonly cause systemic infections and are transmitted between host populations by asymptomatic carriers. The secondary consequences of efforts to eliminate host-restricted Salmonella serovars demonstrate that basic ecological principles govern the environmental niches occupied by these pathogens, making it impossible to thwart Salmonella infections without a clear understanding of the human, animal, and environmental reservoirs of these pathogens. Thus, transmission of S. enterica provides a compelling example of the One Health paradigm because reducing human infections will require the reduction of Salmonella in animals and limitation of transmission from the environment.

Superficial veterinary mycoses.

PubMed

Bond, Ross

2010-03-04

Dermatophytes are significant pathogens in animal health due to their zoonotic potential, the economic consequences of infection in farm animal and fur production systems, and the distressing lesions they cause in small domestic pets. Malassezia spp are normal commensal and occasional pathogens of the skin of many veterinary species. Malassezia pachydermatis is a very common cause of otitis and pruritic dermatitis in dogs but is of less importance in other veterinary species. Dermatophytosis, and Malassezia otitis and dermatitis, represent the superficial mycoses of greatest significance in companion and farm animal health. Although the dermatophytes and Malassezia spp both exist in the stratum corneum of mammalian skin, there are important differences in the epidemiology, pathogenesis, and clinical consequences of infection. Dermatophytes are significant due to their zoonotic potential, the economic consequences of infection in farm animal and fur production systems, and the concern for owners of pets with inflammatory skin disease that is sometimes severe. Malassezia spp are normal commensals and occasional pathogens of the skin for many veterinary species, and M pachydermatis is a very common cause of otitis and pruritic dermatitis in dogs. This chapter will focus on the epidemiologic, clinical, diagnostic, and therapeutic aspects of dermatophytosis and Malassezia dermatitis in veterinary species. There are generally only sporadic reports of other superficial mycoses, such as candidiasis, piedra, and Rhodotorula dermatitis in veterinary medicine, and these are not included here. Copyright 2010 Elsevier Inc. All rights reserved.

The Interface between Fungal Biofilms and Innate Immunity.

PubMed

Kernien, John F; Snarr, Brendan D; Sheppard, Donald C; Nett, Jeniel E

2017-01-01

Fungal biofilms are communities of adherent cells surrounded by an extracellular matrix. These biofilms are commonly found during infection caused by a variety of fungal pathogens. Clinically, biofilm infections can be extremely difficult to eradicate due to their resistance to antifungals and host defenses. Biofilm formation can protect fungal pathogens from many aspects of the innate immune system, including killing by neutrophils and monocytes. Altered immune recognition during this phase of growth is also evident by changes in the cytokine profiles of monocytes and macrophages exposed to biofilm. In this manuscript, we review the host response to fungal biofilms, focusing on how these structures are recognized by the innate immune system. Biofilms formed by Candida, Aspergillus , and Cryptococcus have received the most attention and are highlighted. We describe common themes involved in the resilience of fungal biofilms to host immunity and give examples of biofilm defenses that are pathogen-specific.

An aversion to Verticillium

USDA-ARS?s Scientific Manuscript database

Verticillium wilt is a one of the most serious diseases affecting field production of ornamental trees and shrubs. The disease is caused by the soilborne fungus, Verticillium dahliae. The pathogen is very common in agricultural fields and infects hundreds of economically important plant species incl...

Unlocking the secrets of columnaris disease

USDA-ARS?s Scientific Manuscript database

Columnaris disease, caused by the bacterial pathogen Flavobacterium columnare, continues to be a major problem worldwide and commonly leads to tremendous losses of both wild and cultured freshwater fish, particularly in intensively farmed aquaculture species such as channel catfish. Despite its ecol...

Case-Control Pilot Study on Acute Diarrheal Disease in a Geographically Defined Pediatric Population in a Middle Income Country

PubMed Central

Farfán-García, Ana E.; Zhang, Chengxian; Imdad, Aamer; Arias-Guerrero, Monica Y.; Sánchez-Alvarez, Nayibe T.; Shah, Rikhil; Iqbal, Junaid; Tamborski, Maria E.

2017-01-01

Introduction Acute diarrheal disease (ADD) is a common cause of morbidity and mortality in children under 5 years of age. Understanding of the etiology of ADD is lacking in most low and middle income countries because reference laboratories detect limited number of pathogens. The objective of this study was to determine the feasibility to conduct a comprehensive case-control study to survey diarrheal pathogens among children with and without moderate-to-severe ADD. Materials and Methods Microbiology and molecular-based techniques were used to detect viral, bacterial, and parasitic enteropathogens. The study was conducted in Bucaramanga, Colombia, after Institutional Review Board approval was obtained. Results Ninety children less than 5 years of age were recruited after a written informed consent was obtained from parents or guardians. Forty-five subjects served as cases with ADD and 45 as controls. Thirty-six subjects out of 90 (40.0%) were positive for at least one enteropathogen, that is, 20 (44.4%) cases and 16 (35.5%) controls. Conclusions The three most common enteric pathogens were enteroaggregative E. coli (10.0%), Norovirus (6.7%), and Salmonella spp. (5.6%). The E. coli pathogens were 18.8% of all infections making them the most frequent pathogens. Half of ADD cases were negative for any pathogens. PMID:28855919

An overview of calf diarrhea - infectious etiology, diagnosis, and intervention

PubMed Central

Cho, Yong-il

2014-01-01

Calf diarrhea is a commonly reported disease in young animals, and still a major cause of productivity and economic loss to cattle producers worldwide. In the report of the 2007 National Animal Health Monitoring System for U.S. dairy, half of the deaths among unweaned calves was attributed to diarrhea. Multiple pathogens are known or postulated to cause or contribute to calf diarrhea development. Other factors including both the environment and management practices influence disease severity or outcomes. The multifactorial nature of calf diarrhea makes this disease hard to control effectively in modern cow-calf operations. The purpose of this review is to provide a better understanding of a) the ecology and pathogenesis of well-known and potential bovine enteric pathogens implicated in calf diarrhea, b) describe diagnostic tests used to detect various enteric pathogens along with their pros and cons, and c) propose improved intervention strategies for treating calf diarrhea. PMID:24378583

Diarrheagenic Escherichia coli

PubMed Central

Nataro, James P.; Kaper, James B.

1998-01-01

Escherichia coli is the predominant nonpathogenic facultative flora of the human intestine. Some E. coli strains, however, have developed the ability to cause disease of the gastrointestinal, urinary, or central nervous system in even the most robust human hosts. Diarrheagenic strains of E. coli can be divided into at least six different categories with corresponding distinct pathogenic schemes. Taken together, these organisms probably represent the most common cause of pediatric diarrhea worldwide. Several distinct clinical syndromes accompany infection with diarrheagenic E. coli categories, including traveler’s diarrhea (enterotoxigenic E. coli), hemorrhagic colitis and hemolytic-uremic syndrome (enterohemorrhagic E. coli), persistent diarrhea (enteroaggregative E. coli), and watery diarrhea of infants (enteropathogenic E. coli). This review discusses the current level of understanding of the pathogenesis of the diarrheagenic E. coli strains and describes how their pathogenic schemes underlie the clinical manifestations, diagnostic approach, and epidemiologic investigation of these important pathogens. PMID:9457432

Common Features of Opportunistic Premise Plumbing Pathogens

PubMed Central

Falkinham, Joseph O.

2015-01-01

Recently it has been estimated that the annual cost of diseases caused by the waterborne pathogens Legionella pneumonia, Mycobacterium avium, and Pseudomonas aeruginosa is $500 million. For the period 2001–2012, the estimated cost of hospital admissions for nontuberculous mycobacterial pulmonary disease, the majority caused by M. avium, was almost $1 billion. These three waterborne opportunistic pathogens are normal inhabitants of drinking water—not contaminants—that share a number of key characteristics that predispose them to survival, persistence, and growth in drinking water distribution systems and premise plumbing. Herein, I list and describe these shared characteristics that include: disinfectant-resistance, biofilm-formation, growth in amoebae, growth at low organic carbon concentrations (oligotrophic), and growth under conditions of stagnation. This review is intended to increase awareness of OPPPs, identify emerging OPPPs, and challenge the drinking water industry to develop novel approaches toward their control. PMID:25918909

Poultry: the most common food in outbreaks with known pathogens, United States, 1998-2012.

PubMed

Chai, S J; Cole, D; Nisler, A; Mahon, B E

2017-01-01

As poultry consumption continues to increase worldwide, and as the United States accounts for about one-third of all poultry exports globally, understanding factors leading to poultry-associated foodborne outbreaks in the United States has important implications for food safety. We analysed outbreaks reported to the United States' Foodborne Disease Outbreak Surveillance System from 1998 to 2012 in which the implicated food or ingredient could be assigned to one food category. Of 1114 outbreaks, poultry was associated with 279 (25%), accounting for the highest number of outbreaks, illnesses, and hospitalizations, and the second highest number of deaths. Of the 149 poultry-associated outbreaks caused by a confirmed pathogen, Salmonella enterica (43%) and Clostridium perfringens (26%) were the most common pathogens. Restaurants were the most commonly reported location of food preparation (37% of poultry-associated outbreaks), followed by private homes (25%), and catering facilities (13%). The most commonly reported factors contributing to poultry-associated outbreaks were food-handling errors (64%) and inadequate cooking (53%). Effective measures to reduce poultry contamination, promote safe food-handling practices, and ensure food handlers do not work while ill could reduce poultry-associated outbreaks and illnesses.

Bacterial Pathogens Associated with Community-acquired Pneumonia in Children Aged Below Five Years.

PubMed

Das, Anusmita; Patgiri, Saurav J; Saikia, Lahari; Dowerah, Pritikar; Nath, Reema

2016-03-01

To determine the spectrum of bacterial pathogens causing community-acquired pneumonia in children below 5 years of age. Children aged below 5 years satisfying the WHO criteria for pneumonia, severe pneumonia or very severe pneumonia, and with the presence of lung infiltrates on chest X-ray were enrolled. Two respiratory samples, one for culture and the other for PCR analysis, and a blood sample for culture were collected from every child. Of the 180 samples processed, bacterial pathogens were detected in 64.4%. Streptococcus pneumoniae and Hemophilus influenzae were most frequently detected. The performance of PCR analysis and culture were identical for the typical bacterial pathogens; atypical pathogens were detected by PCR analysis only. S. pneumoniae and H. influenza were the most commonly detected organisms from respiratory secretions of children with community acquired pneumonia.

Convergent pathogenic pathways in Alzheimer’s and Huntington disease: Shared targets for drug development

PubMed Central

Ehrnhoefer, Dagmar E.; Wong, Bibiana K.Y.; Hayden, Michael R.

2011-01-01

Neurodegenerative diseases exemplified by Alzheimer’s and Huntington disease are characterized by the progressive neuropsychiatric dysfunction and loss of specific neuronal subtypes. Even though there are differences in the exact sites of pathology and clinical profiles only partially overlap, considerable similarities in disease mechanisms and pathogenic pathways can be observed. These shared mechanisms raise the possibility of common therapeutic targets for drug development. Huntington disease with a monogenic cause and the possibility to accurately identify pre-manifest mutation carriers could be exploited as a ‘model’ for Alzheimer’s disease to test the efficacy of therapeutic interventions targeting shared pathogenic pathways. PMID:22015920

Obtaining Highly Purified Toxoplasma gondii Oocysts by a Discontinuous Cesium Chloride Gradient

EPA Science Inventory

Toxoplasma gondii is an obligate intracellular protozoan pathogen that commonly infects humans. It is a well characterized apicomplexan associated with causing food- and water-borne disease outbreaks. The definitive host is the feline species where sexual replication occurs res...

CHARACTERIZATION OF VIRAL RNA EXTRACTION EFFICIENCY FROM ENVIRONMENTAL WATERS

EPA Science Inventory

Inhibition of PCR by environmental factors is a common problem affecting the sensitive detection of pathogenic microorganisms in environmental waters. This inhibition is caused by one of three mechanisms: 1) failure to lyse the microorganism, 2) degradation or sequestering of the...

[Diarrhea from the infectologist's point of view].

PubMed

Nemes, Zsuzsanna

2009-02-22

Gastroenteritis is a nonspecific term for various pathologic states of the gastrointestinal tract. Gastroenteritis causing pathogens are the second leading cause of morbidity and mortality worldwide. In the developed countries diarrhea is the most common reason for missing work, while in the developing world, it is a leading cause of death. Internationally, the mortality rate is 5-10 million deaths each year. "Traveller's diarrhea" is a polyetiologic common health problem of international travellers which affects travellers generally for days, but it can result in chronic postinfectious irritable bowel syndrome as well. Infectious agents usually cause acute gastroenteritis either by adherence of the intestinal mucosa, or by mucosal invasion, enterotoxin production, and/or cytotoxin production. The incubation period can often suggest the cause of etiology. When symptoms occur within 6 hours of eating, ingestion of preformed toxin of S. aureus or Bacillus cereus should be suspected. The incidence of hypervirulent C. difficile associated colitis is an emerging problem as a healthcare system associated infection. While infectious agents do not commonly cause chronic diarrhea, those that do include C. difficile, Giardia lamblia, Entamoeba histolytica, Cryptosporidium, Aeromonas and Yersinia . Amoebiasis is the second to malaria as a protozoal cause of death. Infection with HIV is also a common cause of diarrhea.

Genome analysis of the ubiquitous boxwood pathogen Pseudonectria foliicola: A small fungal genome with an increased cohort of genes associated with loss of virulence

USDA-ARS?s Scientific Manuscript database

Boxwood plants are affected by many different diseases caused by fungi. Some boxwood diseases are deadly and quickly kill the infected plants, but with others, the plant can survive and even thrive when infected. The fungus that causes volutella blight is the most common of these weak boxwood pathog...

Apoptosis, Toll-like, RIG-I-like and NOD-like Receptors Are Pathways Jointly Induced by Diverse Respiratory Bacterial and Viral Pathogens

PubMed Central

Martínez, Isidoro; Oliveros, Juan C.; Cuesta, Isabel; de la Barrera, Jorge; Ausina, Vicente; Casals, Cristina; de Lorenzo, Alba; García, Ernesto; García-Fojeda, Belén; Garmendia, Junkal; González-Nicolau, Mar; Lacoma, Alicia; Menéndez, Margarita; Moranta, David; Nieto, Amelia; Ortín, Juan; Pérez-González, Alicia; Prat, Cristina; Ramos-Sevillano, Elisa; Regueiro, Verónica; Rodriguez-Frandsen, Ariel; Solís, Dolores; Yuste, José; Bengoechea, José A.; Melero, José A.

2017-01-01

Lower respiratory tract infections are among the top five leading causes of human death. Fighting these infections is therefore a world health priority. Searching for induced alterations in host gene expression shared by several relevant respiratory pathogens represents an alternative to identify new targets for wide-range host-oriented therapeutics. With this aim, alveolar macrophages were independently infected with three unrelated bacterial (Streptococcus pneumoniae, Klebsiella pneumoniae, and Staphylococcus aureus) and two dissimilar viral (respiratory syncytial virus and influenza A virus) respiratory pathogens, all of them highly relevant for human health. Cells were also activated with bacterial lipopolysaccharide (LPS) as a prototypical pathogen-associated molecular pattern. Patterns of differentially expressed cellular genes shared by the indicated pathogens were searched by microarray analysis. Most of the commonly up-regulated host genes were related to the innate immune response and/or apoptosis, with Toll-like, RIG-I-like and NOD-like receptors among the top 10 signaling pathways with over-expressed genes. These results identify new potential broad-spectrum targets to fight the important human infections caused by the bacteria and viruses studied here. PMID:28298903

Comparative Pathogenomics Reveals Horizontally Acquired Novel Virulence Genes in Fungi Infecting Cereal Hosts

PubMed Central

Gardiner, Donald M.; McDonald, Megan C.; Covarelli, Lorenzo; Solomon, Peter S.; Rusu, Anca G.; Marshall, Mhairi; Kazan, Kemal; Chakraborty, Sukumar; McDonald, Bruce A.; Manners, John M.

2012-01-01

Comparative analyses of pathogen genomes provide new insights into how pathogens have evolved common and divergent virulence strategies to invade related plant species. Fusarium crown and root rots are important diseases of wheat and barley world-wide. In Australia, these diseases are primarily caused by the fungal pathogen Fusarium pseudograminearum. Comparative genomic analyses showed that the F. pseudograminearum genome encodes proteins that are present in other fungal pathogens of cereals but absent in non-cereal pathogens. In some cases, these cereal pathogen specific genes were also found in bacteria associated with plants. Phylogenetic analysis of selected F. pseudograminearum genes supported the hypothesis of horizontal gene transfer into diverse cereal pathogens. Two horizontally acquired genes with no previously known role in fungal pathogenesis were studied functionally via gene knockout methods and shown to significantly affect virulence of F. pseudograminearum on the cereal hosts wheat and barley. Our results indicate using comparative genomics to identify genes specific to pathogens of related hosts reveals novel virulence genes and illustrates the importance of horizontal gene transfer in the evolution of plant infecting fungal pathogens. PMID:23028337

Brucella melitensis and Mycobacterium tuberculosis depict overlapping gene expression patterns induced in infected THP-1 macrophages.

PubMed

Masoudian, M; Derakhshandeh, A; Ghahramani Seno, M M

2015-01-01

Pathogens infecting mammalian cells have developed various strategies to suppress and evade their hosts' defensive mechanisms. In this line, the intracellular bacteria that are able to survive and propagate within their host cells must have developed strategies to avert their host's killing attitude. Studying the interface of host-pathogen confrontation can provide valuable information for defining therapeutic approaches. Brucellosis, caused by the Brucella strains, is a zoonotic bacterial disease that affects thousands of humans and animals around the world inflicting discomfort and huge economic losses. Similar to many other intracellular dwelling bacteria, infections caused by Brucella are difficult to treat, and hence any attempt at identifying new and common therapeutic targets would prove beneficial for the purpose of curing infections caused by the intracellular bacteria. In THP-1 macrophage infected with Brucella melitensis we studied the expression levels of four host's genes, i.e. EMP2, ST8SIA4, HCP5 and FRMD5 known to be involved in pathogenesis of Mycobacterium tuberculosis. Our data showed that at this molecular level, except for FRMD5 that was downregulated, the other three genes were upregulated by B. melitensis. Brucella melitensis and M. tuberculosis go through similar intracellular processes and interestingly two of the investigated genes, i.e. EMP2 and ST4SIA8 were upregulated in THP-1 cell infected with B. melitensis similar to that reported for THP-1 cells infected with M. tuberculosis. At the host-pathogen interaction interface, this study depicts overlapping changes for different bacteria with common survival strategies; a fact that implies designing therapeutic approaches based on common targets may be possible.

Pathogenic seedborne viruses are rare but Phaseolus vulgaris endornaviruses are common in bean varieties grown in Nicaragua and Tanzania.

PubMed

Nordenstedt, Noora; Marcenaro, Delfia; Chilagane, Daudi; Mwaipopo, Beatrice; Rajamäki, Minna-Liisa; Nchimbi-Msolla, Susan; Njau, Paul J R; Mbanzibwa, Deusdedith R; Valkonen, Jari P T

2017-01-01

Common bean (Phaseolus vulgaris) is an annual grain legume that was domesticated in Mesoamerica (Central America) and the Andes. It is currently grown widely also on other continents including Africa. We surveyed seedborne viruses in new common bean varieties introduced to Nicaragua (Central America) and in landraces and improved varieties grown in Tanzania (eastern Africa). Bean seeds, harvested from Nicaragua and Tanzania, were grown in insect-controlled greenhouse or screenhouse, respectively, to obtain leaf material for virus testing. Equal amounts of total RNA from different samples were pooled (30-36 samples per pool), and small RNAs were deep-sequenced (Illumina). Assembly of the reads (21-24 nt) to contiguous sequences and searches for homologous viral sequences in databases revealed Phaseolus vulgaris endornavirus 1 (PvEV-1) and PvEV-2 in the bean varieties in Nicaragua and Tanzania. These viruses are not known to cause symptoms in common bean and are considered non-pathogenic. The small-RNA reads from each pool of samples were mapped to the previously characterized complete PvEV-1 and PvEV-2 sequences (genome lengths ca. 14 kb and 15 kb, respectively). Coverage of the viral genomes was 87.9-99.9%, depending on the pool. Coverage per nucleotide ranged from 5 to 471, confirming virus identification. PvEV-1 and PvEV-2 are known to occur in Phaseolus spp. in Central America, but there is little previous information about their occurrence in Nicaragua, and no information about occurrence in Africa. Aside from Cowpea mild mosaic virus detected in bean plants grown from been seeds harvested from one region in Tanzania, no other pathogenic seedborne viruses were detected. The low incidence of infections caused by pathogenic viruses transmitted via bean seeds may be attributable to new, virus-resistant CB varieties released by breeding programs in Nicaragua and Tanzania.

Detection of rotavirus and other enteropathogens in children hospitalized with acute gastroenteritis in Havana, Cuba.

PubMed

Ribas, María de Los Angeles; Tejero, Yahisel; Cordero, Yanislet; de Los Angeles León, María; Rodriguez, Misladys; Perez-Lastre, Jorge; Triana, Thelma; Guerra, Mabel; Ayllón, Lucía; Escalante, Gladys; Hadad, Jorge

2015-08-01

The aim of the study was to diagnose infections with rotavirus and other enteric pathogens in children under five years old with acute gastroenteritis and to identify the most common epidemiological and clinical characteristics of these pathogens. The study was conducted using 110 stool samples from the same number of children under five years old who were inpatients at three paediatric hospitals in Havana, Cuba, between October and December 2011. The samples were tested for rotavirus and other enteric pathogens using traditional and molecular microbiological methods. Pathogens were detected in 85 (77.3 %) of the children. Rotavirus was the most commonly found, appearing in 54.5 % of the children, followed by bacteria (29 %) and parasites (10.9 %). Other viral pathogens detected included adenovirus (6.4 %) and astrovirus (3.6 %). In rotavirus-positives cases, at least one other pathogen was detected, usually a bacterium (26.6 %). More than three episodes of watery diarrhea in 24 hours were observed in 78.3 % of the cases. Dehydration was found in 30 (50 %) rotavirus-positive children, of whom seven (11.6 %) were transferred to an intensive care unit due to complications of metabolic acidosis. Rotavirus was most commonly observed among children under 12 months old (65 %). The highest incidence of infection occurred in children who were under the care of a relative at home (78.3 %), had not been breastfed (65 %), or had been breastfed for less than six months (28.3 %). The genotype combinations most frequently found were G9P8 (28.3 %) and G1P8 (10 %). This study demonstrates the presence of rotavirus and other enteric pathogens as causes of gastroenteritis in hospitalized infants and young children in Cuba.

Parkinson disease-associated mutations in LRRK2 cause centrosomal defects via Rab8a phosphorylation.

PubMed

Madero-Pérez, Jesús; Fdez, Elena; Fernández, Belén; Lara Ordóñez, Antonio J; Blanca Ramírez, Marian; Gómez-Suaga, Patricia; Waschbüsch, Dieter; Lobbestael, Evy; Baekelandt, Veerle; Nairn, Angus C; Ruiz-Martínez, Javier; Aiastui, Ana; López de Munain, Adolfo; Lis, Pawel; Comptdaer, Thomas; Taymans, Jean-Marc; Chartier-Harlin, Marie-Christine; Beilina, Alexandria; Gonnelli, Adriano; Cookson, Mark R; Greggio, Elisa; Hilfiker, Sabine

2018-01-23

Mutations in LRRK2 are a common genetic cause of Parkinson's disease (PD). LRRK2 interacts with and phosphorylates a subset of Rab proteins including Rab8a, a protein which has been implicated in various centrosome-related events. However, the cellular consequences of such phosphorylation remain elusive. Human neuroblastoma SH-SY5Y cells stably expressing wildtype or pathogenic LRRK2 were used to test for polarity defects in the context of centrosomal positioning. Centrosomal cohesion deficits were analyzed from transiently transfected HEK293T cells, as well as from two distinct peripheral cell types derived from LRRK2-PD patients. Kinase assays, coimmunoprecipitation and GTP binding/retention assays were used to address Rab8a phosphorylation by LRRK2 and its effects in vitro. Transient transfections and siRNA experiments were performed to probe for the implication of Rab8a and its phosphorylated form in the centrosomal deficits caused by pathogenic LRRK2. Here, we show that pathogenic LRRK2 causes deficits in centrosomal positioning with effects on neurite outgrowth, cell polarization and directed migration. Pathogenic LRRK2 also causes deficits in centrosome cohesion which can be detected in peripheral cells derived from LRRK2-PD patients as compared to healthy controls, and which are reversed upon LRRK2 kinase inhibition. The centrosomal cohesion and polarity deficits can be mimicked when co-expressing wildtype LRRK2 with wildtype but not phospho-deficient Rab8a. The centrosomal defects induced by pathogenic LRRK2 are associated with a kinase activity-dependent increase in the centrosomal localization of phosphorylated Rab8a, and are prominently reduced upon RNAi of Rab8a. Our findings reveal a new function of LRRK2 mediated by Rab8a phosphorylation and related to various centrosomal defects.

Community-acquired urinary tract infection in hospitalized children: etiology and antimicrobial resistance. A comparison between first episode and recurrent infection.

PubMed

Sakran, Waheeb; Smolkin, Vladislav; Odetalla, Ahmad; Halevy, Raphael; Koren, Ariel

2015-05-01

Urinary tract infection (UTI) is common in infants and children, and Escherichia coli is the leading pathogen. The aims of this study were to compare first episode of UTI with recurrent infection, reveal organisms that cause UTI, uropathogen resistance, and presence of bacteria producing extended-spectrum β-lactamase (ESBL). The first-UTI group included 456 children. E coli was the leading pathogen (80.5%), and Pseudomonas aeruginosa was found in 1.5%. The uropathogens were resistant to gentamicin (3.41%) and cefuroxime (5.71%), and highly resistant to cefamezin (37.39%). The recurrent-infection group included 106 children. E coli was also the leading pathogen, but 7.5% of the isolates were P aeruginosa (P = .002 compared with first-episode group); 6.6% were ESBL-producing bacteria compared with 1.1% in the first-episode group (P = .002). E coli is the leading pathogen in both groups. P aeruginosa and ESBL-producing bacteria were more common in the recurrent infection group. © The Author(s) 2014.

Current pathogenic Escherichia coli foodborne outbreak cases and therapy development.

PubMed

Yang, Shih-Chun; Lin, Chih-Hung; Aljuffali, Ibrahim A; Fang, Jia-You

2017-08-01

Food contamination by pathogenic microorganisms has been a serious public health problem and a cause of huge economic losses worldwide. Foodborne pathogenic Escherichia coli (E. coli) contamination, such as that with E. coli O157 and O104, is very common, even in developed countries. Bacterial contamination may occur during any of the steps in the farm-to-table continuum from environmental, animal, or human sources and cause foodborne illness. To understand the causes of the foodborne outbreaks by E. coli and food-contamination prevention measures, we collected and investigated the past 10 years' worldwide reports of foodborne E. coli contamination cases. In the first half of this review article, we introduce the infection and symptoms of five major foodborne diarrheagenic E. coli pathotypes: enteropathogenic E. coli (EPEC), Shiga toxin-producing E. coli/enterohemorrhagic E. coli (STEC/EHEC), Shigella/enteroinvasive E. coli (EIEC), enteroaggregative E. coli (EAEC), and enterotoxigenic E. coli (ETEC). In the second half of this review article, we introduce the foodborne outbreak cases caused by E. coli in natural foods and food products. Finally, we discuss current developments that can be applied to control and prevent bacterial food contamination.

Metabolic evidence of diminished lipid oxidation in women with polycystic ovary syndrome

USDA-ARS?s Scientific Manuscript database

Complex diseases, such as polycystic ovary syndrome (PCOS), are not limited to specific genes, pathogens, toxicoses, or identifiable environmental influences. PCOS still remains a diagnosis of exclusion despite being the most common female endocrinopathy and the leading cause of metabolic syndrome, ...

Seroprevalence of CANINE LEISHMANIASIS AND American trypanosomiasis in dogs from Grenada, West Indies

USDA-ARS?s Scientific Manuscript database

Canine leishmaniasis and American trypanosomiasis (AT) are caused by related hemoflagellated parasites, Leishmania spp. and Trypanosoma cruzi, which share several common host species. Dogs are reservoirs for human infections with both pathogens. We determined the prevalence of antibodies to Leishman...

Consensus guidelines for the treatment of invasive mould infections in haematological malignancy and haemopoietic stem cell transplantation, 2014.

PubMed

Blyth, C C; Gilroy, N M; Guy, S D; Chambers, S T; Cheong, E Y; Gottlieb, T; McGuinness, S L; Thursky, K A

2014-12-01

Mould species represent the pathogens most commonly associated with invasive fungal disease in patients with haematological malignancies and patients of haemopoietic stem cell transplants. Invasive mould infections in these patient populations, particularly in the setting of neutropenia, are associated with high morbidity and mortality, and significantly increase the complexity of management. While Aspergillus species remain the most prevalent cause of invasive mould infections, Scedosporium and Fusarium species and the Mucormycetes continue to place a significant burden on the immunocompromised host. Evidence also suggests that infections caused by rare and emerging pathogens are increasing within the setting of broad-spectrum antifungal prophylaxis and improved survival times placing immunosuppressed patients at risk for longer. These guidelines present evidence-based recommendations for the antifungal management of common, rare and emerging mould infections in both adult and paediatric populations. Where relevant, the role of surgery, adjunctive therapy and immunotherapy is also discussed. © 2014 The Authors; Internal Medicine Journal © 2014 Royal Australasian College of Physicians.

Results of a 6-month survey of stool cultures for Escherichia coli O157:H7.

PubMed

Marshall, W F; McLimans, C A; Yu, P K; Allerberger, F J; Van Scoy, R E; Anhalt, J P

1990-06-01

Escherichia coli O157:H7 is a recently recognized enteric pathogen that causes acute hemorrhagic colitis. Although the infection is usually self-limited, it may be complicated by hemolytic uremic syndrome and thrombotic thrombocytopenic purpura. At our institution, stool specimens are now routinely cultured for this organism. To determine the prevalence of E. coli O157:H7-associated diarrhea in our patient population, we surveyed all submitted stool cultures for 6 months for this organism. Specimens were screened for non-sorbitol fermenting E. coli and confirmed by slide-agglutination and immobilization testing. Of 2,164 specimens, 10 yielded E. coli O157:H7. It was the fourth most common bacterial stool pathogen found. Bloody diarrhea and abdominal pain were the most common symptoms of the infected patients. E. coli O157:H7 causes sporadic infections in our patient population and should be considered in the differential diagnosis of acute hemorrhagic colitis.

Serum inflammatory biomarkers and clinical outcomes of COPD exacerbation caused by different pathogens.

PubMed

Kawamatawong, Theerasuk; Apiwattanaporn, Apitch; Siricharoonwong, Warisara

2017-01-01

COPD exacerbation is characterized by worsening of symptoms, warranting change in treatment. Systemic and airway inflammation play roles in the pathogenesis of COPD exacerbation. We hypothesized whether increased serum inflammatory biomarkers are associated with the clinical outcomes of COPD exacerbation caused by different infectious pathogens. COPD patients with exacerbation were recruited from a hospital emergency department during 2014-2015. Serum procalcitonin (PCT) and C-reactive protein (CRP) were measured. Dyspnea, eosinopenia, consolidation, acidemia, and atrial fibrillation (DECAF) score was calculated for predicting mortality. Multiplex polymerase chain reaction was carried out for respiratory viral assay from nasopharyngeal swabs, and sputum bacterial culture was also performed. Hospital mortality, invasive mechanical ventilation requirement, and length of hospital stay (LOS) were evaluated, and their associations with clinical characteristics, DECAF score, and serum biomarkers were examined. A total of 62 COPD patients were enrolled. These patients were classified as Global Initiative for Obstructive Lung Disease (GOLD) stage 2, 3, and 4 in 12.9%, 6.4%, and 80.7% of cases, respectively. Isolated bacterial exacerbation was recovered in 30.6% of exacerbation episodes: Klebsiella pneumoniae was the most commonly identified bacteria. Viral pathogens and coinfections were noted in 9.6% and 16.1% of exacerbated patients, respectively. Influenza was the most commonly detected viral pathogen. Serum biomarkers and DECAF score for viruses, bacteria, coinfection, and noninfectious causes of exacerbations were similar. Neither DECAF score nor serum biomarkers were able to differentiate patients with and without mortality or requiring mechanical ventilation. Increased serum PCT was noted in patients with LOS ≥7 days when compared with those with LOS <7 days (0.38 ng/mL vs 0.1 ng/mL; P =0.035). Increased serum PCT is associated with longer LOS in COPD exacerbation. However, CRP and DECAF score play limited roles in predicting clinical outcome and lack an association with causes of exacerbation.

Transcriptome landscape of a bacterial pathogen under plant immunity.

PubMed

Nobori, Tatsuya; Velásquez, André C; Wu, Jingni; Kvitko, Brian H; Kremer, James M; Wang, Yiming; He, Sheng Yang; Tsuda, Kenichi

2018-03-27

Plant pathogens can cause serious diseases that impact global agriculture. The plant innate immunity, when fully activated, can halt pathogen growth in plants. Despite extensive studies into the molecular and genetic bases of plant immunity against pathogens, the influence of plant immunity in global pathogen metabolism to restrict pathogen growth is poorly understood. Here, we developed RNA sequencing pipelines for analyzing bacterial transcriptomes in planta and determined high-resolution transcriptome patterns of the foliar bacterial pathogen Pseudomonas syringae in Arabidopsis thaliana with a total of 27 combinations of plant immunity mutants and bacterial strains. Bacterial transcriptomes were analyzed at 6 h post infection to capture early effects of plant immunity on bacterial processes and to avoid secondary effects caused by different bacterial population densities in planta We identified specific "immune-responsive" bacterial genes and processes, including those that are activated in susceptible plants and suppressed by plant immune activation. Expression patterns of immune-responsive bacterial genes at the early time point were tightly linked to later bacterial growth levels in different host genotypes. Moreover, we found that a bacterial iron acquisition pathway is commonly suppressed by multiple plant immune-signaling pathways. Overexpression of a P. syringae sigma factor gene involved in iron regulation and other processes partially countered bacterial growth restriction during the plant immune response triggered by AvrRpt2. Collectively, this study defines the effects of plant immunity on the transcriptome of a bacterial pathogen and sheds light on the enigmatic mechanisms of bacterial growth inhibition during the plant immune response.

Interaction of pathogens with host cholesterol metabolism.

PubMed

Sviridov, Dmitri; Bukrinsky, Michael

2014-10-01

Pathogens of different taxa, from prions to protozoa, target cellular cholesterol metabolism to advance their own development and to impair host immune responses, but also causing metabolic complications, for example, atherosclerosis. This review describes recent findings of how pathogens do it. A common theme in interaction between pathogens and host cholesterol metabolism is pathogens targeting lipid rafts of the host plasma membrane. Many intracellular pathogens use rafts as an entry gate, taking advantage of the endocytic machinery and high abundance of outward-looking molecules that can be used as receptors. At the same time, disruption of the rafts' functional capacity, achieved by the pathogens through a number of various means, impairs the ability of the host to generate immune response, thus helping pathogen to thrive. Pathogens cannot synthesize cholesterol, and salvaging host cholesterol helps pathogens build advanced cholesterol-containing membranes and assembly platforms. Impact on cholesterol metabolism is not limited to the infected cells; proteins and microRNAs secreted by infected cells affect lipid metabolism systemically. Given an essential role that host cholesterol metabolism plays in pathogen development, targeting this interaction may be a viable strategy to fight infections, as well as metabolic complications of the infections.

Changing epidemiology of melioidosis? A case of acute pulmonary melioidosis with fatal outcome imported from Brazil.

PubMed Central

Aardema, H.; Luijnenburg, E. M.; Salm, E. F.; Bijlmer, H. A.; Visser, C. E.; Van't Wout, J. W.

2005-01-01

Melioidosis is an infectious disease caused by Burkholderia pseudomallei. It is endemic in South East Asia and tropical regions of Northern Australia. Sporadic cases have been described elsewhere. In this article we present a case of acute pulmonary melioidosis with fatal outcome imported from Brazil. The most common pathogen causing severe community-acquired pneumonia in Brazil is Streptococcus pneumoniae. Other possible pathogens include Legionella spp., Mycoplasma pneumonia, Gram-negative rods and viruses. There are few reports of melioidosis in the Americas. This article represents the second known human case of melioidosis from Brazil. Recognition of melioidosis as a possible cause of severe pneumonia, even if a patient has not been travelling in a highly endemic area, is important because of the therapeutic consequences. The epidemiology of melioidosis will be reviewed. PMID:16181507

It's not all about us: evolution and maintenance of Cryptococcus virulence requires selection outside the human host.

PubMed

Gerstein, Aleeza C; Nielsen, Kirsten

2017-04-01

Cryptococcus is predominantly an AIDS-related pathogen that causes significant morbidity and mortality in immunocompromised patients. Research studies have historically focused on understanding how the organism causes human disease through the use of in vivo and in vitro model systems to identify virulence factors. Cryptococcus is not an obligate pathogen, however, as human-human transmission is either absent or rare. Selection in the environment must thus be invoked to shape the evolution of this taxa, and directly influences genotypic and trait diversity. Importantly, the evolution and maintenance of pathogenicity must also stem directly from environmental selection. To that end, here we examine abiotic and biotic stresses in the environment, and discuss how they could shape the factors that are commonly identified as important virulence traits. We identify a number of important unanswered questions about Cryptococcus diversity and evolution that are critical for understanding this deadly pathogen, and discuss how implementation of modern sampling and genomic tools could be utilized to answer these questions. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Micrococcus species-related peritonitis in patients receiving peritoneal dialysis.

PubMed

Kao, Chih-Chin; Chiang, Chih-Kang; Huang, Jenq-Wen

2014-01-01

Peritonitis is a major complication of peritoneal dialysis (PD) and remains the most common cause of PD failure. Micrococci are catalase-positive, coagulase-negative, and gram-positive cocci that are spherical, often found in tetrad, and belong to the family Micrococcaceae. Micrococcus species are commonly found in the environment, and it is now recognized that Micrococcus species can be opportunistic pathogens in immunocompromised patients. The only consistent predisposing factor for Micrococcus infection is an immunocompromised state. We report three cases of Micrococcus PD peritonitis. Improper practice of PD may have been the causative factor. Although Micrococcus species are low-virulence pathogens, infection could result in refractory peritonitis and subsequent PD failure. Intraperitoneal administration of vancomycin for at least 2 weeks is recommended for Micrococcus peritonitis.

Toscana meningoencephalitis: a comparison to other viral central nervous system infections

PubMed Central

Jaijakul, Siraya; Arias, Cesar A.; Hossein, Monir; Arduino, Roberto C.; Wootton, Susan H.; Hasbun, Rodrigo

2012-01-01

Background Toscana virus (TOSV) is an emerging pathogen causing central nervous system (CNS) infection in Mediterranean countries, mostly during summer season. Objectives To compare the clinical and laboratory characteristics of Toscana CNS infections to the most common viral pathogens seen in the United States. Study Design We performed a case series of patients with 41 TOSV infection and compared the clinical characteristics, laboratory findings, imaging results and clinical outcomes to the most commonly recognized viral causes of meningoencephalitis in the US (enterovirus (n=60), herpes simplex virus (n=48), and west nile virus (n=30) from our multi-center study of patients with aseptic meningoencephalitis syndromes in the Greater Houston area. Results TOSV infection occurs in different age groups compared to enterovirus, HSV, and WNV. All infections most frequently occur during summer-fall except HSV which distributes throughout the year. All patients with TOSV had history of travel to endemic areas. There are differences in clinical presentation and CSF findings comparing TOSV and enterovirus, HSV, and WNV infection. There are no significant differences in outcomes of each infection except WNV meningoencephalitis which had a poorer outcome compared to TOSV infection. Conclusions TOSV is an emerging pathogen that should be considered in the differential diagnosis of patients with CNS infections and a recent travel history to endemic areas. PMID:22867730

The Role of Biofilms in Drinking Water Exposure to Potentially Pathogenic Legionella spp.

EPA Science Inventory

Legionellosis is a bacterial infection caused by species of the genera Legionella and is the most common waterborne disease reported in the United States. This type of infection has two clinically distinct forms: Legionnaire's disease, a severe type of infection, which include...

Protection against common bean rust conferred by a gene silencing method

USDA-ARS?s Scientific Manuscript database

Rust disease of the dry bean plant, Phaseolus vulgaris, is caused by the fungus Uromyces appendiculatus. The fungus acquires its nutrients and energy from bean leaves using a specialized cell structure, the haustorium, through which it secretes effector proteins that contribute to pathogenicity by ...

Plant Natural Compounds with Antibacterial Activity Towards Common Pathogens of Pond-Cultured Channel Catfish (Ictalurus punctatus)

USDA-ARS?s Scientific Manuscript database

The bacteria Edwardsiella ictaluri and Flavobacterium columnare cause enteric septicemia and columnaris disease, respectively, in channel catfish (Ictalurus punctatus). Natural therapeutants may provide an alternative to current management approaches used by producers. In this study, a rapid bioas...

Putative rust fungal effector proteins in infected bean and soybean leaves

USDA-ARS?s Scientific Manuscript database

The plant pathogenic fungi Uromyces appendiculatus and Phakopsora pachyrhizi cause debilitating rust diseases on common bean and soybean. These rust fungi secrete effector proteins that allow them to infect plants, but the effector repertoire for U. appendiculatus and P. pachyrhizi is not fully def...

Vaccine development for protection against systemic infections with Streptococcus suis and Haemophilus parasuis in swine

USDA-ARS?s Scientific Manuscript database

Both Streptococcus suis and Haemophilus parasuis are important invasive bacterial pathogens of swine, commonly causing meningitis, arthritis, polyserositis, and septicemia. Due to the presence of many serotypes and high genotypic variability, efficacious vaccines are not readily available. We are us...

Microbial- and isothiocyanate-mediated control of Phytophthora and Pythium species

Treesearch

M.F. Cohen; E. Yamamoto; E. Condeso; B.L. Anacker; N. Rank; M. Mazzola

2008-01-01

Plant pathogens of the oomycete lineage share common susceptibilities to many biotic and abiotic stresses. We are investigating the potential of antagonistic bacteria, isothiocyanates, and mycophagous amoebae to control diseases caused by Phytophthora spp., including the etiologic agent of sudden oak death, Phytophthora ramorum (...

A fungal pathogen of amphibians, Batrachochytrium dendrobatidis, attenuates in pathogenicity with in vitro passages.

PubMed

Langhammer, Penny F; Lips, Karen R; Burrowes, Patricia A; Tunstall, Tate; Palmer, Crystal M; Collins, James P

2013-01-01

Laboratory investigations into the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), have accelerated recently, given the pathogen's role in causing the global decline and extinction of amphibians. Studies in which host animals were exposed to Bd have largely assumed that lab-maintained pathogen cultures retained the infective and pathogenic properties of wild isolates. Attenuated pathogenicity is common in artificially maintained cultures of other pathogenic fungi, but to date, it is unknown whether, and to what degree, Bd might change in culture. We compared zoospore production over time in two samples of a single Bd isolate having different passage histories: one maintained in artificial media for more than six years (JEL427-P39), and one recently thawed from cryopreserved stock (JEL427-P9). In a common garden experiment, we then exposed two different amphibian species, Eleutherodactylus coqui and Atelopus zeteki, to both cultures to test whether Bd attenuates in pathogenicity with in vitro passages. The culture with the shorter passage history, JEL427-P9, had significantly greater zoospore densities over time compared to JEL427-P39. This difference in zoospore production was associated with a difference in pathogenicity for a susceptible amphibian species, indicating that fecundity may be an important virulence factor for Bd. In the 130-day experiment, Atelopus zeteki frogs exposed to the JEL427-P9 culture experienced higher average infection intensity and 100% mortality, compared with 60% mortality for frogs exposed to JEL427-P39. This effect was not observed with Eleutherodactylus coqui, which was able to clear infection. We hypothesize that the differences in phenotypic performance observed with Atelopus zeteki are rooted in changes of the Bd genome. Future investigations enabled by this study will focus on the underlying mechanisms of Bd pathogenicity.

Aetiology of diarrhoeal disease and evaluation of viral-bacterial coinfection in children under 5 years old in China: a matched case-control study.

PubMed

Li, L L; Liu, N; Humphries, E M; Yu, J M; Li, S; Lindsay, B R; Stine, O C; Duan, Z J

2016-04-01

Globally, diarrhoeal diseases are the second leading cause of death among children under 5 years old. Few case-control studies on the aetiology of diarrhoea have been conducted in China. A case-control study on 922 children under 5 years old who presented with diarrhoea and individually matched controls was conducted in China between May 2011 and January 2013. Quantitative PCR was used to analyze stool samples for 10 diarrhoeal pathogens. Potential enteric pathogens were detected in 377 (81.8%) of 461 children with diarrhoea and 215 controls (46.6%, p <0.001). Rotavirus, norovirus GII, Shigella and adenovirus were qualitatively associated with diarrhoea. Using receiver operating characteristic curves, the optimal cutoff threshold for defining a symptomatic individual was 72, 5840, and 10(4) copies per reaction for rotavirus (odds ratio 259), norovirus GII (odds ratio 10.6) and Shigella (odds ratio 5.1). The attributable fractions were 0.18 for rotavirus, 0.08 for norovirus GII, 0.01 for Shigella and 0.04 for adenovirus. Coinfections between pathogens were common. Two pairs, rotavirus and adenovirus, and norovirus GII and Salmonella were positively associated. The co-occurrence of rotavirus and sapovirus, astrovirus, enterotoxigenic Escherichia coli or Campylobacter jejuni only occurred in children with disease. Coinfection was not correlated with clinical symptoms. Quantitative data are critical. Our results indicate that increased pathogen loads increase the OR between diarrhoea and rotavirus, norovirus GII and Shigella. Coinfections with rotavirus and norovirus GII are common and occur in a nonrandom distribution. Despite testing for ten diarrhoeal pathogens, over two-thirds of cases do not have a recognized attributable cause. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Norovirus prevalence in ‘pathogen negative’ gastroenteritis in children from periurban areas in Lima, Peru

PubMed Central

Rivera, Fulton P.; Ochoa, Theresa J.; Ruiz, Joaquim; Medina, Anicia M.; Ecker, Lucie; Mercado, Erik; Gil, Ana I.; Huicho, Luis; Lanata, Claudio F.

2011-01-01

Summary Norovirus was detected in 17.4% of 224 diarrhoeal samples from children younger than 24 months of age in Lima, in whom all common pathogens had been excluded (pathogen negative). Norovirus was identified more frequently in children older than 12 months of age than in younger children (34% vs 8%, P<0.001). Among norovirus-positive samples, genogroup II was the predominant group (92%). Compared with rotavirus, norovirus episodes tended to be of shorter duration and less severe. The role of norovirus as a cause of diarrhoea and the ascertainment of its severity in developing countries needs further confirmation by future epidemiological studies. PMID:21962615

Fast detection of Listeria monocytogenes through a nanohybrid quantum dot complex.

PubMed

Donoso, Wendy; Castro, Ricardo I; Guzmán, Luis; López-Cabaña, Zoraya; Nachtigall, Fabiane M; Santos, Leonardo S

2017-09-01

Listeria monocytogenes is a recognized foodborne pathogen that causes listeriosis in susceptible consumers. Currently, the detection systems for Listeria in food detect live and dead bacteria, being the viable microorganisms most relevant for their ability to cause sickness in the population at risk. For this reason, a new nanohybrid compound was developed for the optical detection of Listeria that was based on polyamidoamine dendrimers functionalized with an auxotrophic cofactor (lipoic acid), together with the coupling of fluorescent semiconductor crystals (quantum dots). The nanohybrid sensor has a detection limit for viable L. monocytogenes of 5.19 × 10 3 colony-forming units per milliliter under epifluorescence microscopy. It was specific when used among other pathogens commonly found in food.

Characterization and pathogenicity assessment of gut-associated microbes of muga silkworm Antheraea assamensis Helfer (Lepidoptera: Saturniidae).

PubMed

Haloi, Kishor; Kalita, Moni Kankana; Nath, Ramesh; Devi, Dipali

2016-07-01

Antheraea assamensis Helfer (muga silkworm) is an economically important endemic insect species of North Eastern Region of India. The silkworm is often susceptible to infection by pathogenic bacteria, leads to a disease commonly known as flacherie which causes 40% loss per annum to the silk industry. In this study, we have reported isolation, characterization and pathogenicity assessment of gut-associated bacteria of healthy and diseased muga silkworms. Thirty five bacterial isolates were screened from the gut of healthy and diseased silkworms by morphological observation and biochemical tests. 11 and 5 strains from healthy and diseased silkworm respectively were identified by 16S rRNA gene sequencing and analyzed. Pseudomonas aeruginosa (DRK1), Ornithinibacillus bavariensis (DRK2), Achromobacter xylosoxidans (KH3) and Staphylococcus aureus (FLG1) strains were commonly found in healthy as well as diseased larvae whereas, Bacillus thuringiensis (MK1) was found only in diseased larvae. Survivability analysis was performed with the identified strains by injection and oral administration (10(4)CFU/ml). The immune response of the silkworm against the pathogen was also studied by phenoloxidase and lysozyme enzyme activity assay, total and differential hemocyte count and phagocytic activity of hemocytes. It was observed that S. aureus, P. aeruginosa and B. thuringiensis significantly reduced the survivability of silkworm (p<0.001) hence found highly pathogenic. The lethal concentrations (LC50) values of the pathogenic strains were calculated at different time intervals (24, 48, 72 and 96h) within the range from 1.38×10(2) to 3.63×10(7)CFU/ml. The pathogenic groups demonstrated inhibition of phenoloxidase activity and decreased in total hemocyte count after 48h of infection. However, the lysozyme activity increased significantly in the pathogenic groups compared to the control (p<0.05). Granulocytes and plasmatocytes showed phagocytosis whereas; other types of cells did not show any phagocytic activity. Increasing granulocytes and plasmatocytes counts corroborates the results of phagocytic activity. The present study might be helpful in understanding the disease prognosis and colonization of bacteria causing the disease in muga silkworm. Copyright © 2016 Elsevier Inc. All rights reserved.

Dynamic transcriptome profiling of Bean Common Mosaic Virus (BCMV) infection in Common Bean (Phaseolus vulgaris L.).

PubMed

Martin, Kathleen; Singh, Jugpreet; Hill, John H; Whitham, Steven A; Cannon, Steven B

2016-08-11

Bean common mosaic virus (BCMV) is widespread, with Phaseolus species as the primary host plants. Numerous BCMV strains have been identified on the basis of a panel of bean varieties that distinguish the pathogenicity types with respect to the viral strains. The molecular responses in Phaseolus to BCMV infection have not yet been well characterized. We report the transcriptional responses of a widely susceptible variety of common bean (Phaseolus vulgaris L., cultivar 'Stringless green refugee') to two BCMV strains, in a time-course experiment. We also report the genome sequence of a previously unreported BCMV strain. The interaction with the known strain NL1-Iowa causes moderate symptoms and large transcriptional responses, and the newly identified strain (Strain 2 or S2) causes severe symptoms and moderate transcriptional responses. The transcriptional profiles of host plants infected with the two isolates are distinct, and involve numerous differences in splice forms in particular genes, and pathway specific expression patterns. We identified differential host transcriptome response after infection of two different strains of Bean common mosaic virus (BCMV) in common bean (Phaseolus vulgaris L.). Virus infection initiated a suite of changes in gene expression level and patterns in the host plants. Pathways related to defense, gene regulation, metabolic processes, photosynthesis were specifically altered after virus infection. Results presented in this study can increase the understanding of host-pathogen interactions and provide resources for further investigations of the biological mechanisms in BCMV infection and defense.

Tick-Borne Zoonoses in the United States: Persistent and Emerging Threats to Human Health

PubMed Central

Eisen, Rebecca J.; Kugeler, Kiersten J.; Eisen, Lars; Beard, Charles B.; Paddock, Christopher D.

2017-01-01

In the United States, ticks transmit the greatest diversity of arthropod-borne pathogens and are responsible for the most cases of all vector-borne diseases. In recent decades, the number of reported cases of notifiable tick-borne diseases has steadily increased, geographic distributions of many ticks and tick-borne diseases have expanded, and new tick-borne disease agents have been recognized. In this review, we (1) describe the known disease agents associated with the most commonly human-biting ixodid ticks, (2) review the natural histories of these ticks and their associated pathogens, (3) highlight spatial and temporal changes in vector tick distributions and tick-borne disease occurrence in recent decades, and (4) identify knowledge gaps and barriers to more effective prevention of tick-borne diseases. We describe 12 major tick-borne diseases caused by 15 distinct disease agents that are transmitted by the 8 most commonly human-biting ixodid ticks in the United States. Notably, 40% of these pathogens were described within the last two decades. Our assessment highlights the importance of animal studies to elucidate how tick-borne pathogens are maintained in nature, as well as advances in molecular detection of pathogens which has led to the discovery of several new tick-borne disease agents. PMID:28369515

Participation of necroptosis in the host response to acute bacterial pneumonia

PubMed Central

Ahn, Danielle; Prince, Alice

2017-01-01

Common pulmonary pathogens, such as Streptococcus pneumoniae and Staphylococcus aureus as well as the host-adapted pathogens responsible for health care associated pneumonias such as the carbapenem-resistant Klebsiella pneumoniae and Serratia marcesens are able to activate cell death through the RIPK1/RIPK3/MLKL cascade that causes necroptosis. Necroptosis can influence the pathogenesis of pneumonia through several mechanisms. Activation of this pathway can result in the loss of specific types of immune cells, especially macrophages and in doing so contribute to host pathology through loss of their critical immunoregulatory functions. However, in other settings of infection, necroptosis promotes pathogen removal and eradication of infected cells to control excessive proinflammatory signaling. Bacterial production of pore forming toxins provides a common mechanism to activate necroptosis by diverse bacterial species, with variable consequences depending upon the specific pathogen. Included in this brief review are data demonstrating the ability of the carbapenem-resistant ST258 K. pneumoniae to activate necroptosis in the setting of pneumonia, which is counterbalanced by their suppression of CYLD expression. Exactly how necroptosis and other mechanisms of cell death are co-regulated in the response to specific pulmonary pathogens remains a topic of active investigation and may provide potential therapeutic targets in the future. PMID:28125817

Participation of Necroptosis in the Host Response to Acute Bacterial Pneumonia.

PubMed

Ahn, Danielle; Prince, Alice

2017-01-01

Common pulmonary pathogens, such as Streptococcus pneumoniae and Staphylococcus aureus, as well as the host-adapted pathogens responsible for health care-associated pneumonias, such as the carbapenem-resistant Klebsiella pneumoniae and Serratia marcecsens, are able to activate cell death through the RIPK1/RIPK3/MLKL cascade that causes necroptosis. Necroptosis can influence the pathogenesis of pneumonia through several mechanisms. Activation of this pathway can result in the loss of specific types of immune cells, especially macrophages, and, in so doing, contribute to host pathology through the loss of their critical immunoregulatory functions. However, in other settings of infection, necroptosis promotes pathogen removal and the eradication of infected cells to control excessive proinflammatory signaling. Bacterial production of pore-forming toxins provides a common mechanism to activate necroptosis by diverse bacterial species, with variable consequences depending upon the specific pathogen. Included in this brief review are data demonstrating the ability of the carbapenem-resistant ST258 K. pneumoniae to activate necroptosis in the setting of pneumonia, which is counterbalanced by their suppression of CYLD expression. Exactly how necroptosis and other mechanisms of cell death are coregulated in the response to specific pulmonary pathogens remains a topic of active investigation, and it may provide potential therapeutic targets in the future. © 2017 S. Karger AG, Basel.

[THE CLINICAL AND EPIDEMIOLOGICAL CHARACTERISTICS OF MALARIA CONCURRENT WITH OTHER INFECTIONS AND INVASIONS].

PubMed

Kondrashin, A V; Tokmalaev, A K; Morozov, E N; Morozova, L F

2016-01-01

The present review considers malaria infection concurrent with different species of helminths, bacterial and viral infections, as well as mixed malaria pathogens in the subtropical and tropical countries of the world, causing the clinical picture and epidemiological situation to be different. Malaria co-infections with different pathogenic micro-organisms, such as HIV, tuberculosis, viral hepatitides, and others, affect almost one third of the planet's population. It is known that people who are at risk for malaria may be also at risk for other parasitic and infectious diseases, most commonly helminthisms.

Wild-type and mutant SOD1 share an aberrant conformation and a common pathogenic pathway in ALS

PubMed Central

Bosco, Daryl A.; Morfini, Gerardo; Karabacak, N. Murat; Song, Yuyu; Gros-Louis, Francois; Pasinelli, Piera; Goolsby, Holly; Fontaine, Benjamin A.; Lemay, Nathan; McKenna-Yasek, Diane; Frosch, Matthew P.; Agar, Jeffery N.; Julien, Jean-Pierre; Brady, Scott T.; Brown, Robert H.

2010-01-01

Many mutations confer upon copper/zinc superoxide dismutase-1 (SOD1) one or more toxic function(s) that impair motor neuron viability and cause familial amyotrophic lateral sclerosis (FALS). Using a conformation-specific antibody that detects misfolded SOD1 (C4F6), we demonstrate that oxidized WT-SOD1 and mutant-SOD1 share a conformational epitope that is not present in normal WT-SOD1. In a subset of human sporadic ALS (SALS) cases, motor neurons in the lumbosacral spinal cord displayed striking C4F6 immunoreactivity, denoting the presence of aberrant WT-SOD1 species. Recombinant, oxidized WT-SOD1 and WT-SOD1 immunopurified from SALS tissues inhibited kinesin-based fast axonal transport in a manner similar to FALS-linked mutant SOD1. Studies here suggest that WT-SOD1 can be pathogenic in SALS and identifies an SOD1-dependent pathogenic mechanism common to FALS and SALS. PMID:20953194

Genome-wide association study of anthracnose resistance in Andean beans

USDA-ARS?s Scientific Manuscript database

Anthracnose is a seed-borne disease of common bean (Phaseolus vulgaris L.) caused by the fungus Colletotrichum lindemuthianum, and the pathogen is cosmopolitan in distribution. The objectives of this study were to identify new sources of anthracnose resistance in a diverse panel of 230 Andean beans ...

Antimicrobial efficacy of radiant catalytic ionization against shiga toxin-producing Escherichia coli on inoculated beef

USDA-ARS?s Scientific Manuscript database

Introduction: Shiga Toxin-producing Escherichia coli (STEC), as a common foodborne pathogen, may cause severe human hemorrhagic colitis infection. The radiant catalytic ionization (RCI) technology utilizes a combination of UV light and low-level oxidizers such as ozone, hydroxyl radicals, and hydrog...

Characterization of resistance to powdery mildew in the Hop cultivars Newport and Comet

USDA-ARS?s Scientific Manuscript database

Hop powdery mildew, caused by Podosphaera macularis, is an important disease in the Northwestern U.S. Outbreaks of powdery mildew on cultivars previously resistant to the disease have been reported increasingly with the emergence of virulent pathogen strains capable of overcoming a commonly deployed...

Heroes and villains: Research identifies harmful and beneficial microbes in nursery soil

USDA-ARS?s Scientific Manuscript database

Phytophthora and Pythium species are common pathogens in nursery systems that can cause rhododendron root rot. Plants with root rot are often stunted, and may wilt and die, thus directly reducing nursery profit. Rhododendrons are an important crop in Pacific Northwest nurseries, but are highly susc...

Development of a two-step, non-probed multiplex real-time PCR for surveilling Vibrio anguillarum in seawater

USDA-ARS?s Scientific Manuscript database

Vibrio anguillarum is an aggressive and halophilic bacterial pathogen commonly found in seawater. Its presence in aquaculture facilities causes significant morbidity and mortality among aquaculture species primarily from hemorrhaging of the body and skin of the infected fish that eventually leads t...

In vitro selection of enteric microflora for potential use as a probiotic culture against Campylobacter in poultry.

USDA-ARS?s Scientific Manuscript database

Campylobacter is one of the most commonly reported bacterial causes of human foodborne illness and epidemiological evidence indicates poultry and poultry products as significant sources of human Campylobacter infection. In an effort to reduce colonization of enteric pathogens in poultry, scientists...

Contributions of hydrology to Vesicular Stomatitis Virus emergence in the Western United States

USDA-ARS?s Scientific Manuscript database

Relationships between environmental variables associated with the spread of vector-borne pathogens, such as RNA viruses transmitted to humans and animals, remain poorly understood. Vesicular stomatitis (VS) is caused by a vector-borne, zoonotic RNA virus (VSV), and is the most common vesicular dise...

Biology, biological control and molecular genetics of root diseases of wheat and barley

USDA-ARS?s Scientific Manuscript database

Root diseases cause billions of dollars annually in losses to cereal growers. Resistance to foliar diseases is common, but resistance to root diseases is rare. Soilborne pathogens of cereals are managed through crop rotation, tillage, and chemical seed treatments. However, plants also defend themsel...

Identification of Bordetella bronchseptica in fatal pneumonia of dogs and cats

USDA-ARS?s Scientific Manuscript database

Infection with Bordetella bronchiseptica is a common cause of tracheobronchitis and upper respiratory disease in dogs and cats, but it can also lead to fatal pneumonia. Identification of this pathogen is important due the risk of transmission to other animals, availability of vaccines and potential...

Winter Iinjury of American chestnut seedlings grown in a common garden at the species' northern range limit

Treesearch

Paul G. Schaberg; Thomas M. Saielli; Gary J. Hawley; Joshua M. Halman; Kendra M. Gurney

2013-01-01

Hybridization of American chestnut (Castanea dentata) with Chinese chestnut (C. mollissima), followed by backcrossing to American chestnut, is conducted to increase the resistance of resulting stock to chestnut blight, caused by the fungal pathogen Cryphonectria parasitica (Murr.) Barr. Backcross breeding is...

Persistence of Mycobacterium bovis Bacillus Calmette-Guerin (BCG) in White-tailed Deer (Odocoileus virginianus) After Oral or Parenteral Vaccination

USDA-ARS?s Scientific Manuscript database

Mycobacterium bovis is the cause of tuberculosis in cattle and a serious zoonotic pathogen, most commonly contracted through consumption of unpasteurized dairy products. To control this zoonosis, many countries have developed bovine tuberculosis eradication programs. Although relatively successful, ...

Development of hyperspectral imaging technique for salmonella enteritidis and typhimurium on agar plates

USDA-ARS?s Scientific Manuscript database

Salmonella is a common cause of foodborne disease resulting from the consumption of contaminated food products. Although a direct plating method is widely used for presumptive positive screening of pathogenic Salmonella colonies on agar plates, it is labor-intensive, time-consuming and also prone to...

Gene expression profiling in chicken heterophils with Salmonella enteritidis stimulation using a chicken 44 K Agilent microarray

USDA-ARS?s Scientific Manuscript database

Salmonella enterica serovar Enteritidis (SE) is one of the most common food-borne pathogens that cause human salmonellosis and usually results from the consumption of contaminated poultry products. The mechanism of SE resistance in chickens remains largely unknown. Previously, heterophils isolated...

DEVELOPMENT OF A MOLECULAR METHOD TO IDENTIFY HEPATITIS E VIRUS

EPA Science Inventory

Hepatitis E virus (HEV) is a waterborne emerging pathogen that causes significant illness in the developing world. Thus far, an HEV outbreak has not been reported in the U.S., although a swine variant of the virus is common in Midwestern hogs. Because viruses isolated from two ...

Primer prueba de desafio controlado en tilapia del Nilo Para Resistencia a Streptococcus iniae

USDA-ARS?s Scientific Manuscript database

Intensification of tilapia production has resulted in disease outbreaks that negatively affect commercial fish farmers. One bacterial pathogen that commonly causes losses in tilapia production is Streptococcus iniae. Control and prevention of S. iniae can be difficult and requires an integrated fish...

Alfalfa and pastures: sources of pests or generalist natural enemies?

USDA-ARS?s Scientific Manuscript database

Pierce’s disease of grapevine and almond leaf scorch disease are both caused by the bacterial pathogen Xyllela fastidiosa. In the Central Valley of California, the green sharpshooter is the most common vector of X. fastidiosa. As alfalfa fields and pastures are considered source habitats for green s...

Colony Collapse Disorder: A Descriptive Study

PubMed Central

vanEngelsdorp, Dennis; Evans, Jay D.; Saegerman, Claude; Mullin, Chris; Haubruge, Eric; Nguyen, Bach Kim; Frazier, Maryann; Frazier, Jim; Cox-Foster, Diana; Chen, Yanping; Underwood, Robyn; Tarpy, David R.; Pettis, Jeffery S.

2009-01-01

Background Over the last two winters, there have been large-scale, unexplained losses of managed honey bee (Apis mellifera L.) colonies in the United States. In the absence of a known cause, this syndrome was named Colony Collapse Disorder (CCD) because the main trait was a rapid loss of adult worker bees. We initiated a descriptive epizootiological study in order to better characterize CCD and compare risk factor exposure between populations afflicted by and not afflicted by CCD. Methods and Principal Findings Of 61 quantified variables (including adult bee physiology, pathogen loads, and pesticide levels), no single measure emerged as a most-likely cause of CCD. Bees in CCD colonies had higher pathogen loads and were co-infected with a greater number of pathogens than control populations, suggesting either an increased exposure to pathogens or a reduced resistance of bees toward pathogens. Levels of the synthetic acaricide coumaphos (used by beekeepers to control the parasitic mite Varroa destructor) were higher in control colonies than CCD-affected colonies. Conclusions/Significance This is the first comprehensive survey of CCD-affected bee populations that suggests CCD involves an interaction between pathogens and other stress factors. We present evidence that this condition is contagious or the result of exposure to a common risk factor. Potentially important areas for future hypothesis-driven research, including the possible legacy effect of mite parasitism and the role of honey bee resistance to pesticides, are highlighted. PMID:19649264

Ischaemic stroke and Clostridium septicum sepsis and meningitis in a patient with occult colon carcinoma - a case report and review of the literature.

PubMed

Macha, Kosmas; Giede-Jeppe, Antje; Lücking, Hannes; Coras, Roland; Huttner, Hagen B; Held, Jürgen

2016-11-24

Clostridium septicum is a rare cause of meningitis and brain abscess in children and adults. Gas production by the pathogen can lead to pneumocephalus and the overall mortality rate of Clostridium septicum CNS infection is as high as 74%. The most common entry site of the pathogen is the gastrointestinal tract. We describe a 74-year-old man who presented with a left-sided cerebral infarction in the middle cerebral artery territory. In addition the patient showed signs of Systemic Inflammatory Response Syndrome and Disseminated Intravascular Coagulation. Examination of blood cultures and cerebrospinal fluid led to the diagnosis of sepsis and meningitis caused by Clostridium septicum. Despite appropriate antibiotic therapy the condition of the patient deteriorated rapidly and he died on day 2 after admission. Autopsy revealed a previously unknown adenocarcinoma of the colon ascendens as entry site of the pathogen. Clostridium septicum should be considered as potential pathogen in patients with sepsis and meningitis. Gram stain morphology in conjunction with severe sepsis can rapidly point into the direction of this pathogen. CNS infections manifest either as meningoencephalitis/cerebritis or as brain abscess. Entry site of the pathogen is almost uniquely the gastrointestinal tract. In adults more than 50% suffer from colorectal carcinoma, therefore survivors of Clostridium septicum infections should be examined for underlying occult colorectal malignancy.

Colony collapse disorder: a descriptive study.

PubMed

Vanengelsdorp, Dennis; Evans, Jay D; Saegerman, Claude; Mullin, Chris; Haubruge, Eric; Nguyen, Bach Kim; Frazier, Maryann; Frazier, Jim; Cox-Foster, Diana; Chen, Yanping; Underwood, Robyn; Tarpy, David R; Pettis, Jeffery S

2009-08-03

Over the last two winters, there have been large-scale, unexplained losses of managed honey bee (Apis mellifera L.) colonies in the United States. In the absence of a known cause, this syndrome was named Colony Collapse Disorder (CCD) because the main trait was a rapid loss of adult worker bees. We initiated a descriptive epizootiological study in order to better characterize CCD and compare risk factor exposure between populations afflicted by and not afflicted by CCD. Of 61 quantified variables (including adult bee physiology, pathogen loads, and pesticide levels), no single measure emerged as a most-likely cause of CCD. Bees in CCD colonies had higher pathogen loads and were co-infected with a greater number of pathogens than control populations, suggesting either an increased exposure to pathogens or a reduced resistance of bees toward pathogens. Levels of the synthetic acaricide coumaphos (used by beekeepers to control the parasitic mite Varroa destructor) were higher in control colonies than CCD-affected colonies. This is the first comprehensive survey of CCD-affected bee populations that suggests CCD involves an interaction between pathogens and other stress factors. We present evidence that this condition is contagious or the result of exposure to a common risk factor. Potentially important areas for future hypothesis-driven research, including the possible legacy effect of mite parasitism and the role of honey bee resistance to pesticides, are highlighted.

Genomes and Virulence Factors of Novel Bacterial Pathogens Causing Bleaching Disease in the Marine Red Alga Delisea pulchra

PubMed Central

Fernandes, Neil; Case, Rebecca J.; Longford, Sharon R.; Seyedsayamdost, Mohammad R.; Steinberg, Peter D.; Kjelleberg, Staffan; Thomas, Torsten

2011-01-01

Nautella sp. R11, a member of the marine Roseobacter clade, causes a bleaching disease in the temperate-marine red macroalga, Delisea pulchra. To begin to elucidate the molecular mechanisms underpinning the ability of Nautella sp. R11 to colonize, invade and induce bleaching of D. pulchra, we sequenced and analyzed its genome. The genome encodes several factors such as adhesion mechanisms, systems for the transport of algal metabolites, enzymes that confer resistance to oxidative stress, cytolysins, and global regulatory mechanisms that may allow for the switch of Nautella sp. R11 to a pathogenic lifestyle. Many virulence effectors common in phytopathogenic bacteria are also found in the R11 genome, such as the plant hormone indole acetic acid, cellulose fibrils, succinoglycan and nodulation protein L. Comparative genomics with non-pathogenic Roseobacter strains and a newly identified pathogen, Phaeobacter sp. LSS9, revealed a patchy distribution of putative virulence factors in all genomes, but also led to the identification of a quorum sensing (QS) dependent transcriptional regulator that was unique to pathogenic Roseobacter strains. This observation supports the model that a combination of virulence factors and QS-dependent regulatory mechanisms enables indigenous members of the host alga's epiphytic microbial community to switch to a pathogenic lifestyle, especially under environmental conditions when innate host defence mechanisms are compromised. PMID:22162749

Children hospitalized due to acute otitis media: how does this condition differ from acute mastoiditis?

PubMed

Laulajainen-Hongisto, Anu; Saat, Riste; Lempinen, Laura; Aarnisalo, Antti A; Jero, Jussi

2015-09-01

To evaluate the clinical picture and microbiological findings of children hospitalized due to acute otitis media and to analyze how it differs from acute mastoiditis. A retrospective review of the medical records of all children (0-16 years) hospitalized due to acute otitis media in the Department of Otorhinolaryngology at the Helsinki University Hospital, between 2003 and 2012. Comparison with previously published data of children with acute mastoiditis (n=56) from the same institute and period of time. The most common pathogens in the children hospitalized due to acute otitis media (n=44) were Streptococcus pneumoniae (18%), Pseudomonas aeruginosa (16%), Streptococcus pyogenes (14%), and Staphylococcus aureus (14%). One of the most common pathogens of out-patient acute otitis media, Haemophilus influenzae, was absent. Otorrhea was common in infections caused by S. pyogenes and otorrhea via tympanostomy tube in infections caused by P. aeruginosa. In children under 2 years-of-age, the most common pathogens were S. pneumoniae (43%), Moraxella catarrhalis (14%), and S. aureus (7%). S. pyogenes and P. aeruginosa were only found in children over 2 years-of-age. Previous health problems, bilateral infections, and facial nerve paresis were more common in children hospitalized due to acute otitis media, compared with acute mastoiditis, but they also demonstrated lower CRP values and shorter duration of hospital stay. The number of performed tympanostomies and mastoidectomies was also comparatively smaller in the children hospitalized due to acute otitis media. S. aureus was more common and S. pneumoniae, especially its resistant strains, was less common in the children hospitalized due to acute otitis media than acute mastoiditis. Acute otitis media requiring hospitalization and acute mastoiditis compose a continuum of complicated acute otitis media that differs from common out-patient acute otitis media. The bacteriology of children hospitalized due to acute otitis media resembled more the bacteriology of acute mastoiditis than that of out-patient acute otitis media. The children hospitalized due to acute otitis media needed less surgical treatment and a shorter hospitalization than those hospitalized due to acute mastoiditis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Utilizing Bacillus to inhibit the growth and infection by sheath blight pathogen, Rhizoctoniasolani in rice

NASA Astrophysics Data System (ADS)

Margani, R.; Hadiwiyono; Widadi, S.

2018-03-01

Rhizoctonia solani Kuhn is a common pathogen of rice. The pathogen causes sheath blight of rice. The pathogen can cause loss in the production of rice up to 45%. So far, the disease however is still poorly taken care of by the farmers and researchers, so the control measures is nearly never practiced by the farmers in the fields. It due to the unavailability of effective control method of the disease. Therefore, development to control the disease is important. Bacillus is one of popular bacteria which is effective as biological control agent of a lot of pathogens in plants, but it has not been used for control sheath blight in rice yet. The current researches were aimed to study the potential of Bacillus collected from healthy rice as candidates of biological control agent of the disease. The results showed that some isolates showed indications to inhibit significantly the growth and infection of the pathogen. We obtained at least five isolates of Bacillus collected from leaves, sheath, and stem of healthy rice fields. All of the isolates could effectively inhibit the growth of R. solani in vitro on potato dextrose medium at range 30.33-58.00%, whereas in vivo B05 isolate was the most effective in inhibiting the infection of pathogen at 30.43%. It was not significantly different (P≥0.05) to application of hexaconazol with dosage of 2 ml L-1.

Potential worldwide distribution of Fusarium dry root rot in common beans based on the optimal environment for disease occurrence.

PubMed

Macedo, Renan; Sales, Lilian Patrícia; Yoshida, Fernanda; Silva-Abud, Lidianne Lemes; Lobo, Murillo

2017-01-01

Root rots are a constraint for staple food crops and a long-lasting food security problem worldwide. In common beans, yield losses originating from root damage are frequently attributed to dry root rot, a disease caused by the Fusarium solani species complex. The aim of this study was to model the current potential distribution of common bean dry root rot on a global scale and to project changes based on future expectations of climate change. Our approach used a spatial proxy of the field disease occurrence, instead of solely the pathogen distribution. We modeled the pathogen environmental requirements in locations where in-situ inoculum density seems ideal for disease manifestation. A dataset of 2,311 soil samples from commercial farms assessed from 2002 to 2015 allowed us to evaluate the environmental conditions associated with the pathogen's optimum inoculum density for disease occurrence, using a lower threshold as a spatial proxy. We encompassed not only the optimal conditions for disease occurrence but also the optimal pathogen's density required for host infection. An intermediate inoculum density of the pathogen was the best disease proxy, suggesting density-dependent mechanisms on host infection. We found a strong convergence on the environmental requirements of both the host and the disease development in tropical areas, mostly in Brazil, Central America, and African countries. Precipitation and temperature variables were important for explaining the disease occurrence (from 17.63% to 43.84%). Climate change will probably move the disease toward cooler regions, which in Brazil are more representative of small-scale farming, although an overall shrink in total area (from 48% to 49% in 2050 and 26% to 41% in 2070) was also predicted. Understanding pathogen distribution and disease risks in an evolutionary context will therefore support breeding for resistance programs and strategies for dry root rot management in common beans.

A Presenilin-1 Mutation Identified in Familial Alzheimer Disease with Cotton Wool Plaques Causes a Nearly Complete Loss of γ-Secretase Activity*

PubMed Central

Heilig, Elizabeth A.; Xia, Weiming; Shen, Jie; Kelleher, Raymond J.

2010-01-01

Mutations in presenilin-1 and presenilin-2 (PS1 and PS2) are the most common cause of familial Alzheimer disease. PS1 and PS2 are the presumptive catalytic components of the multisubunit γ-secretase complex, which proteolyzes a number of type I transmembrane proteins, including the amyloid precursor protein (APP) and Notch. APP processing by γ-secretase produces β-amyloid peptides (Aβ40 and Aβ42) that accumulate in the Alzheimer disease brain. Here we identify a pathogenic L435F mutation in PS1 in two affected siblings with early-onset familial Alzheimer disease characterized by deposition of cerebral cotton wool plaques. The L435F mutation resides in a conserved C-terminal PAL sequence implicated in active site conformation and catalytic activity. The impact of PS1 mutations in and around the PAL motif on γ-secretase activity was assessed by expression of mutant PS1 in mouse embryo fibroblasts lacking endogenous PS1 and PS2. Surprisingly, the L435F mutation caused a nearly complete loss of γ-secretase activity, including >90% reductions in the generation of Aβ40, Aβ42, and the APP and Notch intracellular domains. Two nonpathogenic PS1 mutations, P433L and L435R, caused essentially complete loss of γ-secretase activity, whereas two previously identified pathogenic PS1 mutations, P436Q and P436S, caused partial loss of function with substantial reductions in production of Aβ40, Aβ42, and the APP and Notch intracellular domains. These results argue against overproduction of Aβ42 as an essential property of presenilin proteins bearing pathogenic mutations. Rather, our findings provide support for the hypothesis that pathogenic mutations cause a general loss of presenilin function. PMID:20460383

Novel Antigens for enterotoxigenic Escherichia coli (ETEC) Vaccines

PubMed Central

Fleckenstein, James M.; Sheikh, Alaullah; Qadri, Firdausi

2014-01-01

Enterotoxigenic Escherichia coli (ETEC) are the most common bacterial pathogens-causing diarrhea in developing countries where they cause hundreds of thousands of deaths, mostly in children. These organisms are leading cause of diarrheal illness in travelers to endemic countries. ETEC pathogenesis, and consequently vaccine approaches, have largely focused on plasmid-encoded enterotoxins or fimbrial colonization factors. To date these approaches have not yielded a broadly protective vaccine. However, recent studies suggest that ETEC pathogenesis is more complex than previously appreciated and involves additional plasmid and chromosomally-encoded virulence molecules that can be targeted in vaccines. Here, we review recent novel antigen discovery efforts, potential contribution of these proteins to the molecular pathogenesis of ETEC and protective immunity, and the potential implications for development of next generation vaccines for important pathogens. These proteins may help to improve the effectiveness of future vaccines by making simpler and possibly broadly protective because of their conserved nature. PMID:24702311

[Invasive fungal disease due to Scedosporium, Fusarium and mucorales].

PubMed

Pemán, Javier; Salavert, Miguel

2014-01-01

The number of emerging organisms causing invasive fungal infections has increased in the last decades. These etiological agents include Scedosporium, Fusarium and mucorales. All of them can cause disseminated, virulent, and difficult-to treat infections in immunosuppressed patients, the most affected, due to their resistance to most available antifungal agents. Current trends in transplantation including the use of new immunosuppressive treatments, the common prescription of antifungal agents for prophylaxis, and new ecological niches could explain the emergence of these fungal pathogens. These pathogens can also affect immunocompetent individuals, especially after natural disasters (earthquakes, floods, tsunamis), combat wounds or near drowning. All the invasive infections caused by Scedosporium, Fusarium, and mucorales are potentially lethal and a favourable outcome is associated with rapid diagnosis by direct microscopic examination of the involved tissue, wide debridement of infected material, early use of antifungal agents including combination therapy, and an improvement in host defenses, especially neutropenia. Copyright © 2014. Published by Elsevier Espana.

Coagulase-negative staphylococci as reservoirs of genes facilitating MRSA infection

PubMed Central

Otto, Michael

2013-01-01

Recent research has suggested that Staphylococcus epidermidis is a reservoir of genes that, after horizontal transfer, facilitate the potential of Staphylococcus aureus to colonize, survive during infection, or resist antibiotic treatment, traits that are notably manifest in methicillin-resistant S. aureus (MRSA). S. aureus is a dangerous human pathogen and notorious for acquiring antibiotic resistance. MRSA in particular is one of the most frequent causes of morbidity and death in hospitalized patients. S. aureus is an extremely versatile pathogen with a multitude of mechanisms to cause disease and circumvent immune defenses. In contrast, most other staphylococci, such as S. epidermidis, are commonly benign commensals and only occasionally cause disease. Recent findings highlight the key importance of efforts to better understand how genes of staphylococci other than S. aureus contribute to survival in the human host, how they are transferred to S. aureus, and why this exchange appears to be uni-directional. PMID:23165978

Urban Breeding Corvids as Disseminators of Ticks and Emerging Tick-Borne Pathogens.

PubMed

Sándor, Attila D; Kalmár, Zsuzsa; Matei, Ioana; Ionică, Angela Monica; Mărcuţan, Ioan-Daniel

2017-02-01

Crows (Corvidae) are common city dwellers worldwide and are increasingly important subjects of epidemiology studies. Although their importance as hosts and transmitters of a number of zoonotic parasites and pathogens is well known, there are no studies on their importance as tick hosts. After mosquitoes, ticks are the most important vectors of zoonotic pathogens, especially for those causing emerging zoonotic diseases. Pathogenic bacteria, especially Borrelia spp., Rickettsia spp., and Anaplasma spp., vectored by ticks, are the cause for most vector-borne diseases in Europe. Here we report on ticks and tick-borne pathogens harbored by urban breeding crows. A total of 36 birds (33.33%, n = 108) hosted ticks, with 91 individual ticks belonging to 6 species (Haemaphysalis concinna, Haemaphysalis parva, Haemaphysalis punctata, Hyalomma marginatum, Ixodes arboricola, and Ixodes ricinus). Rickettsia spp. DNA was found in 6.6% of ticks and 1.9% of bird tissues, whereas Anaplasma phagocytophilum was found in 5.9% of ticks and 0.9% of birds. Two rickettsial genospecies were located, Rickettsia helvetica and Rickettsia monacensis. This is the first study to determine such a diverse tick spectrum feeding on urban corvids, while highlighting their importance as tick hosts and raising concerns about their potential risk to human health.

Screening of Viral Pathogens from Pediatric Ileal Tissue Samples after Vaccination

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

Hewitson, Laura; Thissen, James B.; Gardner, Shea N.

In 2010, researchers reported that the two US-licensed rotavirus vaccines contained DNA or DNA fragments from porcine circovirus (PCV). Although PCV, a common virus among pigs, is not thought to cause illness in humans, these findings raised several safety concerns. In this study, we sought to determine whether viruses, including PCV, could be detected in ileal tissue samples of children vaccinated with one of the two rotavirus vaccines. A broad spectrum, novel DNA detection technology, the Lawrence Livermore Microbial Detection Array (LLMDA), was utilized, and confirmation of viral pathogens using the polymerase chain reaction (PCR) was conducted. The LLMDA technologymore » was recently used to identify PCV from one rotavirus vaccine. Ileal tissue samples were analyzed from 21 subjects, aged 15–62 months. PCV was not detected in any ileal tissue samples by the LLMDA or PCR. LLMDA identified a human rotavirus A from one of the vaccinated subjects, which is likely due to a recent infection from a wild type rotavirus. LLMDA also identified human parechovirus, a common gastroenteritis viral infection, from two subjects. Additionally, LLMDA detected common gastrointestinal bacterial organisms from the Enterobacteriaceae , Bacteroidaceae , and Streptococcaceae families from several subjects. This study provides a survey of viral and bacterial pathogens from pediatric ileal samples, and may shed light on future studies to identify pathogen associations with pediatric vaccinations.« less

Efficacy/safety of amoxicillin/clavulanate in adults with bacterial rhinosinusitis.

PubMed

Anon, Jack B; Berkowitz, Elchonon; Breton, John; Twynholm, Monique

2006-01-01

Acute bacterial rhinosinusitis (ABRS) is a common and uncomfortable condition, frequently caused by Streptococcus pneumoniae or Haemophilus influenzae. Antibacterial resistance among these and other common respiratory pathogens is now widespread and of concern. Pharmacokinetically enhanced amoxicillin/clavulanate 2000/125 mg was developed to be effective against the common respiratory pathogens, including many resistant strains. This open-label, noncomparative study assessed the bacteriologic and clinical efficacy of amoxicillin/clavulanate 2000/125 mg in adult patients with ABRS. Requirements for study entry included a clinical diagnosis of ABRS supported by radiologic findings. In addition, sinus puncture for bacteriologic assessment was required at study entry. Overall, bacteriologic success (eradication or clinical evidence of eradication) at the follow-up visit (days 17-28) was achieved in 87.8% (722/822) of patients with 1 or more pathogen isolated at screening, in 93.2% (246/264) of patients with S pneumoniae, in 96.7% (29/30) of those with penicillin-resistant S pneumoniae (penicillin minimum inhibitory concentrations >or=2 microg/mL), and in 88.7% (110/124) of patients with beta-lactamase-positive pathogens. Bacteriologic success was achieved against 6 of 7 S pneumoniae isolates with amoxicillin/clavulanic acid minimum inhibitory concentrations of 4/2 microg/mL or higher. Amoxicillin/clavulanate 2000/125 mg was generally well tolerated. This new amoxicillin/clavulanate formulation provides a suitable option for empiric therapy for ABRS in adults.

Screening of Viral Pathogens from Pediatric Ileal Tissue Samples after Vaccination

DOE PAGES

Hewitson, Laura; Thissen, James B.; Gardner, Shea N.; ...

2014-01-01

In 2010, researchers reported that the two US-licensed rotavirus vaccines contained DNA or DNA fragments from porcine circovirus (PCV). Although PCV, a common virus among pigs, is not thought to cause illness in humans, these findings raised several safety concerns. In this study, we sought to determine whether viruses, including PCV, could be detected in ileal tissue samples of children vaccinated with one of the two rotavirus vaccines. A broad spectrum, novel DNA detection technology, the Lawrence Livermore Microbial Detection Array (LLMDA), was utilized, and confirmation of viral pathogens using the polymerase chain reaction (PCR) was conducted. The LLMDA technologymore » was recently used to identify PCV from one rotavirus vaccine. Ileal tissue samples were analyzed from 21 subjects, aged 15–62 months. PCV was not detected in any ileal tissue samples by the LLMDA or PCR. LLMDA identified a human rotavirus A from one of the vaccinated subjects, which is likely due to a recent infection from a wild type rotavirus. LLMDA also identified human parechovirus, a common gastroenteritis viral infection, from two subjects. Additionally, LLMDA detected common gastrointestinal bacterial organisms from the Enterobacteriaceae , Bacteroidaceae , and Streptococcaceae families from several subjects. This study provides a survey of viral and bacterial pathogens from pediatric ileal samples, and may shed light on future studies to identify pathogen associations with pediatric vaccinations.« less

Clinical and tree hollow populations of human pathogenic yeast in Hamilton, Ontario, Canada are different.

PubMed

Carvalho, Chris; Yang, Jiaqi; Vogan, Aaron; Maganti, Harinad; Yamamura, Deborah; Xu, Jianping

2014-05-01

Yeast are among the most frequent pathogens in humans. The dominant yeast causing human infections belong to the genus Candida and Candida albicans is the most frequently isolated species. However, several non-C. albicans species are becoming increasingly common in patients worldwide. The relationships between yeast in humans and the natural environments remain poorly understood. Furthermore, it is often difficult to identify or exclude the origins of disease-causing yeast from specific environmental reservoirs. In this study, we compared the yeast isolates from tree hollows and from clinics in Hamilton, Ontario, Canada. Our surveys and analyses showed significant differences in yeast species composition, in their temporal dynamics, and in yeast genotypes between isolates from tree hollows and hospitals. Our results are inconsistent with the hypothesis that yeast from trees constitute a significant source of pathogenic yeast in humans in this region. Similarly, the yeast in humans and clinics do not appear to contribute to yeast in tree hollows. © 2013 Blackwell Verlag GmbH.

Comparative genome analysis of rice-pathogenic Burkholderia provides insight into capacity to adapt to different environments and hosts.

PubMed

Seo, Young-Su; Lim, Jae Yun; Park, Jungwook; Kim, Sunyoung; Lee, Hyun-Hee; Cheong, Hoon; Kim, Sang-Mok; Moon, Jae Sun; Hwang, Ingyu

2015-05-06

In addition to human and animal diseases, bacteria of the genus Burkholderia can cause plant diseases. The representative species of rice-pathogenic Burkholderia are Burkholderia glumae, B. gladioli, and B. plantarii, which primarily cause grain rot, sheath rot, and seedling blight, respectively, resulting in severe reductions in rice production. Though Burkholderia rice pathogens cause problems in rice-growing countries, comprehensive studies of these rice-pathogenic species aiming to control Burkholderia-mediated diseases are only in the early stages. We first sequenced the complete genome of B. plantarii ATCC 43733T. Second, we conducted comparative analysis of the newly sequenced B. plantarii ATCC 43733T genome with eleven complete or draft genomes of B. glumae and B. gladioli strains. Furthermore, we compared the genome of three rice Burkholderia pathogens with those of other Burkholderia species such as those found in environmental habitats and those known as animal/human pathogens. These B. glumae, B. gladioli, and B. plantarii strains have unique genes involved in toxoflavin or tropolone toxin production and the clustered regularly interspaced short palindromic repeats (CRISPR)-mediated bacterial immune system. Although the genome of B. plantarii ATCC 43733T has many common features with those of B. glumae and B. gladioli, this B. plantarii strain has several unique features, including quorum sensing and CRISPR/CRISPR-associated protein (Cas) systems. The complete genome sequence of B. plantarii ATCC 43733T and publicly available genomes of B. glumae BGR1 and B. gladioli BSR3 enabled comprehensive comparative genome analyses among three rice-pathogenic Burkholderia species responsible for tissue rotting and seedling blight. Our results suggest that B. glumae has evolved rapidly, or has undergone rapid genome rearrangements or deletions, in response to the hosts. It also, clarifies the unique features of rice pathogenic Burkholderia species relative to other animal and human Burkholderia species.

Development of a specific polymerase chain reaction assay for the detection of Basidiobolus.

PubMed

Gómez-Muñoz, María Teresa; Fernández-Barredo, Salceda; Martínez-Díaz, Rafael Alberto; Pérez-Gracia, María Teresa; Ponce-Gordo, Francisco

2012-01-01

The etiology of chronic diarrhea is complex in humans and animals. It is always necessary to evaluate a list of differential diagnosis, including bacteria, protozoa and fungi. Basidiobolomycosis is a fungal disease reported sporadically worldwide, mainly caused by B. ranarum, a frequent organism found in soil or in the intestine and skin of lizards and frogs. It is an opportunistic pathogen that causes infections characterized by granulomatous lesions in the subcutaneous tissues as well as in the intestinal wall in humans and animals. In this work we have developed a PCR technique to differentiate Basidiobolus from other causes of intestinal disease in dogs and humans. To test the specificity of the PCR assay we included closely related organisms, common intestinal microbiota and pathogenic organisms, such as Aspergillus, Candida, Cryptosporidium, Escherichia, Giardia, Mucor, Proteus, Rhizopus and Salmonella. Pythium insidiosum, which cause clinically similar disease in dogs but require a different treatment. Only Basidiobolus was positive to the PCR assay.

Rice Bran Amendment Suppresses Potato Common Scab by Increasing Antagonistic Bacterial Community Levels in the Rhizosphere.

PubMed

Tomihama, Tsuyoshi; Nishi, Yatsuka; Mori, Kiyofumi; Shirao, Tsukasa; Iida, Toshiya; Uzuhashi, Shihomi; Ohkuma, Moriya; Ikeda, Seishi

2016-07-01

Potato common scab (PCS), caused by pathogenic Streptomyces spp., is a serious disease in potato production worldwide. Cultural practices, such as optimizing the soil pH and irrigation, are recommended but it is often difficult to establish stable disease reductions using these methods. Traditionally, local farmers in southwest Japan have amended soils with rice bran (RB) to suppress PCS. However, the scientific mechanism underlying disease suppression by RB has not been elucidated. The present study showed that RB amendment reduced PCS by repressing the pathogenic Streptomyces population in young tubers. Amplicon sequencing analyses of 16S ribosomal RNA genes from the rhizosphere microbiome revealed that RB amendment dramatically changed bacterial composition and led to an increase in the relative abundance of gram-positive bacteria such as Streptomyces spp., and this was negatively correlated with PCS disease severity. Most actinomycete isolates derived from the RB-amended soil showed antagonistic activity against pathogenic Streptomyces scabiei and S. turgidiscabies on R2A medium. Some of the Streptomyces isolates suppressed PCS when they were inoculated onto potato plants in a field experiment. These results suggest that RB amendment increases the levels of antagonistic bacteria against PCS pathogens in the potato rhizosphere.

Childhood vulvovaginitis: report of two cases.

PubMed

Tsai, Hsiu-Yuan; Wan, Chuan; Tseng, Ching-Chang

2006-01-01

Vaginal discharge in young prepubertal girls is a common problem in clinical practice. No specific infective pathogen is identified in most of the children. The reported common microbes include group A beta-hemolytic streptococci, Haemophilus influenzae and some Gram-negative bacilli. Sexually transmitted pathogens such as Neisseria gonorrhoeae and Chlamydia trachomatis are important causes of vulvovaginitis in children suffering from sexual abuse. We report two cases of prepubertal vulvovaginitis presenting with profuse purulent vaginal discharge, and H. influenzae and N. gonorrhoeae identified respectively. Both girls denied any sexual exposure and there was no evidence of sexual abuse. They responded well to antibiotic treatment, and no symptoms recurred in the following months. We would like to emphasize the defined etiology of childhood vulvovaginitis and appropriate treatment, in addition to gynecological evaluation for evidence of sexual abuse.

Current methodologies on genotyping for nosocomial pathogen methicillin-resistant Staphylococcus aureus (MRSA).

PubMed

Miao, Jian; Chen, Lequn; Wang, Jingwen; Wang, Wenxin; Chen, Dingqiang; Li, Lin; Li, Bing; Deng, Yang; Xu, Zhenbo

2017-06-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a common pathogen in hospitals and the community. As the rapid spread and wide distribution of antimicrobial resistance (such as MRSA), treatment for infectious diseases caused by microorganisms has become a vital threat. Thus, early identification and genotyping are essential for further therapeutic treatment and the control of rapid expansion of MRSA. In combination with applications and data feedbacks, this review focused on the currently available molecular-based assays on their utility and performance for rapid typing of MRSA, especially on effective molecular-based methods. Besides, a common mobile element SCCmec and prevalence of HA-MRSA, LA-MRSA and CA-MRSA were introduced in this review in order to provide a more complete profile of MRSA. Copyright © 2017 Elsevier Ltd. All rights reserved.

Defining the genetic connection linking amyotrophic lateral sclerosis (ALS) with frontotemporal dementia (FTD).

PubMed

Lattante, Serena; Ciura, Sorana; Rouleau, Guy A; Kabashi, Edor

2015-05-01

Several genetic causes have been recently described for neurological diseases, increasing our knowledge of the common pathological mechanisms involved in these disorders. Mutation analysis has shown common causative factors for two major neurodegenerative disorders, ALS and FTD. Shared pathological and genetic markers as well as common neurological signs between these diseases have given rise to the notion of an ALS/FTD spectrum. This overlap among genetic factors causing ALS/FTD and the coincidence of mutated alleles (including causative, risk and modifier variants) have given rise to the notion of an oligogenic model of disease. In this review we summarize major advances in the elucidation of novel genetic factors in these diseases which have led to a better understanding of the common pathogenic factors leading to neurodegeneration. Copyright © 2015 Elsevier Ltd. All rights reserved.

Coinfection by the tick-borne pathogens Babesia microti and Borrelia burgdorferi: ecological, epidemiological and clinical consequences

PubMed Central

Diuk-Wasser, Maria A.; Vannier, Edouard

2015-01-01

Ixodes ticks maintain a large and diverse array of human pathogens in the enzootic cycle, including Borrelia burgdorferi and Babesia microti. Despite the poor ecological fitness of B. microti, babesiosis has recently emerged in areas endemic for Lyme disease. Studies in ticks, reservoir hosts and humans indicate that coinfection with B. burgdorferi and B. microti is common, promotes transmission and emergence of B. microti in the enzootic cycle, and causes greater disease severity and duration in humans. These integrative studies may serve as a paradigm for the study of other vector-borne coinfections. Identifying ecological drivers of pathogen emergence and host factors that fuel disease severity will help guide the design of effective curative and prevention strategies. PMID:26613664

Economics and financing of vaccines for diarrheal diseases.

PubMed

Bartsch, Sarah M; Lee, Bruce Y

2014-01-01

The considerable burden of infectious disease-caused diarrhea around the world has motivated the continuing development of a number of vaccine candidates over the past several decades with some reaching the market. As with all major public health interventions, understanding the economics and financing of vaccines against diarrheal diseases is essential to their development and implementation. This review focuses on each of the major infectious pathogens that commonly cause diarrhea, the current understanding of their economic burden, the status of vaccine development, and existing economic evaluations of the vaccines. While the literature on the economics and financing of vaccines against diarrhea diseases is growing, there is considerable room for more inquiry. Substantial gaps exist for many pathogens, circumstances, and effects. Economics and financing studies are integral to vaccine development and implementation.

Economics and financing of vaccines for diarrheal diseases

PubMed Central

Bartsch, Sarah M; Lee, Bruce Y

2014-01-01

The considerable burden of infectious disease-caused diarrhea around the world has motivated the continuing development of a number of vaccine candidates over the past several decades with some reaching the market. As with all major public health interventions, understanding the economics and financing of vaccines against diarrheal diseases is essential to their development and implementation. This review focuses on each of the major infectious pathogens that commonly cause diarrhea, the current understanding of their economic burden, the status of vaccine development, and existing economic evaluations of the vaccines. While the literature on the economics and financing of vaccines against diarrhea diseases is growing, there is considerable room for more inquiry. Substantial gaps exist for many pathogens, circumstances, and effects. Economics and financing studies are integral to vaccine development and implementation. PMID:24755623

Persistent anthrax as a major driver of wildlife mortality in a tropical rainforest

NASA Astrophysics Data System (ADS)

Hoffmann, Constanze; Zimmermann, Fee; Biek, Roman; Kuehl, Hjalmar; Nowak, Kathrin; Mundry, Roger; Agbor, Anthony; Angedakin, Samuel; Arandjelovic, Mimi; Blankenburg, Anja; Brazolla, Gregory; Corogenes, Katherine; Couacy-Hymann, Emmanuel; Deschner, Tobias; Dieguez, Paula; Dierks, Karsten; Düx, Ariane; Dupke, Susann; Eshuis, Henk; Formenty, Pierre; Yuh, Yisa Ginath; Goedmakers, Annemarie; Gogarten, Jan F.; Granjon, Anne-Céline; McGraw, Scott; Grunow, Roland; Hart, John; Jones, Sorrel; Junker, Jessica; Kiang, John; Langergraber, Kevin; Lapuente, Juan; Lee, Kevin; Leendertz, Siv Aina; Léguillon, Floraine; Leinert, Vera; Löhrich, Therese; Marrocoli, Sergio; Mätz-Rensing, Kerstin; Meier, Amelia; Merkel, Kevin; Metzger, Sonja; Murai, Mizuki; Niedorf, Svenja; de Nys, Hélène; Sachse, Andreas; van Schijndel, Joost; Thiesen, Ulla; Ton, Els; Wu, Doris; Wieler, Lothar H.; Boesch, Christophe; Klee, Silke R.; Wittig, Roman M.; Calvignac-Spencer, Sébastien; Leendertz, Fabian H.

2017-08-01

Anthrax is a globally important animal disease and zoonosis. Despite this, our current knowledge of anthrax ecology is largely limited to arid ecosystems, where outbreaks are most commonly reported. Here we show that the dynamics of an anthrax-causing agent, Bacillus cereus biovar anthracis, in a tropical rainforest have severe consequences for local wildlife communities. Using data and samples collected over three decades, we show that rainforest anthrax is a persistent and widespread cause of death for a broad range of mammalian hosts. We predict that this pathogen will accelerate the decline and possibly result in the extirpation of local chimpanzee (Pan troglodytes verus) populations. We present the epidemiology of a cryptic pathogen and show that its presence has important implications for conservation.

Persistent anthrax as a major driver of wildlife mortality in a tropical rainforest.

PubMed

Hoffmann, Constanze; Zimmermann, Fee; Biek, Roman; Kuehl, Hjalmar; Nowak, Kathrin; Mundry, Roger; Agbor, Anthony; Angedakin, Samuel; Arandjelovic, Mimi; Blankenburg, Anja; Brazolla, Gregory; Corogenes, Katherine; Couacy-Hymann, Emmanuel; Deschner, Tobias; Dieguez, Paula; Dierks, Karsten; Düx, Ariane; Dupke, Susann; Eshuis, Henk; Formenty, Pierre; Yuh, Yisa Ginath; Goedmakers, Annemarie; Gogarten, Jan F; Granjon, Anne-Céline; McGraw, Scott; Grunow, Roland; Hart, John; Jones, Sorrel; Junker, Jessica; Kiang, John; Langergraber, Kevin; Lapuente, Juan; Lee, Kevin; Leendertz, Siv Aina; Léguillon, Floraine; Leinert, Vera; Löhrich, Therese; Marrocoli, Sergio; Mätz-Rensing, Kerstin; Meier, Amelia; Merkel, Kevin; Metzger, Sonja; Murai, Mizuki; Niedorf, Svenja; De Nys, Hélène; Sachse, Andreas; van Schijndel, Joost; Thiesen, Ulla; Ton, Els; Wu, Doris; Wieler, Lothar H; Boesch, Christophe; Klee, Silke R; Wittig, Roman M; Calvignac-Spencer, Sébastien; Leendertz, Fabian H

2017-08-02

Anthrax is a globally important animal disease and zoonosis. Despite this, our current knowledge of anthrax ecology is largely limited to arid ecosystems, where outbreaks are most commonly reported. Here we show that the dynamics of an anthrax-causing agent, Bacillus cereus biovar anthracis, in a tropical rainforest have severe consequences for local wildlife communities. Using data and samples collected over three decades, we show that rainforest anthrax is a persistent and widespread cause of death for a broad range of mammalian hosts. We predict that this pathogen will accelerate the decline and possibly result in the extirpation of local chimpanzee (Pan troglodytes verus) populations. We present the epidemiology of a cryptic pathogen and show that its presence has important implications for conservation.

Comprehensive Rare Variant Analysis via Whole-Genome Sequencing to Determine the Molecular Pathology of Inherited Retinal Disease.

PubMed

Carss, Keren J; Arno, Gavin; Erwood, Marie; Stephens, Jonathan; Sanchis-Juan, Alba; Hull, Sarah; Megy, Karyn; Grozeva, Detelina; Dewhurst, Eleanor; Malka, Samantha; Plagnol, Vincent; Penkett, Christopher; Stirrups, Kathleen; Rizzo, Roberta; Wright, Genevieve; Josifova, Dragana; Bitner-Glindzicz, Maria; Scott, Richard H; Clement, Emma; Allen, Louise; Armstrong, Ruth; Brady, Angela F; Carmichael, Jenny; Chitre, Manali; Henderson, Robert H H; Hurst, Jane; MacLaren, Robert E; Murphy, Elaine; Paterson, Joan; Rosser, Elisabeth; Thompson, Dorothy A; Wakeling, Emma; Ouwehand, Willem H; Michaelides, Michel; Moore, Anthony T; Webster, Andrew R; Raymond, F Lucy

2017-01-05

Inherited retinal disease is a common cause of visual impairment and represents a highly heterogeneous group of conditions. Here, we present findings from a cohort of 722 individuals with inherited retinal disease, who have had whole-genome sequencing (n = 605), whole-exome sequencing (n = 72), or both (n = 45) performed, as part of the NIHR-BioResource Rare Diseases research study. We identified pathogenic variants (single-nucleotide variants, indels, or structural variants) for 404/722 (56%) individuals. Whole-genome sequencing gives unprecedented power to detect three categories of pathogenic variants in particular: structural variants, variants in GC-rich regions, which have significantly improved coverage compared to whole-exome sequencing, and variants in non-coding regulatory regions. In addition to previously reported pathogenic regulatory variants, we have identified a previously unreported pathogenic intronic variant in CHM in two males with choroideremia. We have also identified 19 genes not previously known to be associated with inherited retinal disease, which harbor biallelic predicted protein-truncating variants in unsolved cases. Whole-genome sequencing is an increasingly important comprehensive method with which to investigate the genetic causes of inherited retinal disease. Copyright © 2017. Published by Elsevier Inc.

RETRACTED ARTICLE: Quorum-sensing of bacteria and its application

NASA Astrophysics Data System (ADS)

Jiang, Guoliang; Su, Mingxia

2009-12-01

Quorum sensing, or auto induction, as a cell density dependent signaling mechanism in many microorganisms, is triggered via auto inducers which passively diffuse across the bacterial envelope and therefore intracellulaly accumulate only at higher bacterial densities to regulate specialized processes such as genetic competence, bioluminescence, virulence and sporulation. N-acyl homoserine lactones are the most common type of signal molecules. Aquaculture is one of the fastest-growing food-producing industries, but disease outbreaks caused by pathogenic bacteria are a significant constraint on the development of the sector worldwide. Many of these pathogens have been found to be controlled by their quorum sensing systems. As there is relevance between the pathogenic bacteria's virulence factor expression and their auto inducers, quorum quenching is a new effective anti-infective strategy to control infections caused by bacterial pathogens in aquaculture. The techniques used to do this mainly include the following: (1) the inhibition of signal molecule biosynthesis, (2) blocking signal transduction, and (3) chemical inactivation and biodegradation of signal molecules. To provide a basis for finding alternative means of controlling aquatic diseases by quorum quenching instead of treatment by antibiotics and disinfectants, we will discuss the examination, purification and identification of auto inducers in this paper.

High Prevalence of Mycoplasma pneumoniae and Chlamydia pneumoniae in Children with Acute Respiratory Infections from Lima, Peru

PubMed Central

del Valle-Mendoza, Juana; Orellana-Peralta, Fiorella; Marcelo-Rodríguez, Alvaro; Verne, Eduardo; Esquivel-Vizcarra, Mónica; Silva-Caso, Wilmer; Aguilar-Luis, Miguel Angel; Weilg, Pablo; Casabona-Oré, Verónica; Ugarte, Claudia; del Valle, Luis J.

2017-01-01

Background Mycoplasma pneumoniae and Chlamydia pneumoniae are atypical pathogens responsible for pneumonia and a leading cause of morbidity and mortality in low income countries. The study objective is to determine the prevalence of this pathogens in Peruvian children with acute respiratory infections. Methods A consecutive cross-sectional study was conducted in Lima, Peru from May 2009 to September 2010. A total of 675 children admitted with clinical diagnoses of acute respiratory infections were tested for Mycoplasma pneumoniae and Chlamydia pneumoniae detection by polymerase chain reaction (PCR), and clinical symptoms were registered by the attending physician. Results Mycoplasma pneumonia was detected in 25.19% (170/675) of nasopharyngeal samples and Chlamydia pneumonia in 10.52% (71/675). The most common symptoms in patients with these atypical pathogens were rhinorrhea, cough and fever. A higher prevalence of Mycoplasma pneumoniae cases were registered in summer, between December 2009 and March 2010. Conclusions Mycoplasma pneumoniae and Chlamydia pneumonia are a significant cause of morbidity in Peruvian children with acute respiratory infections (ARI). Further studies should evaluate the use of reliable techniques such as PCR in Peru in order to avoid underdiagnoses of these atypical pathogens. PMID:28129377

Canopy gaps decrease microbial densities and disease risk for a shade-intolerant tree species

NASA Astrophysics Data System (ADS)

Reinhart, Kurt O.; Royo, Alejandro A.; Kageyama, Stacie A.; Clay, Keith

2010-11-01

Canopy disturbances such as windthrow events have obvious impacts on forest structure and composition aboveground, but changes in soil microbial communities and the consequences of these changes are less understood. We characterized the densities of a soil-borne pathogenic oomycete ( Pythium) and a common saprotrophic zygomycete ( Mortierella) in nine pairs of forest gaps created by windthrows and adjacent forest understories. We determined the levels of Pythium necessary to cause disease by performing pathogenicity experiments using two Pythium species, a range of Pythium densities, and two common tree species ( Acer rubrum and Prunus serotina) from the study sites. Three years post-disturbance, densities of Mortierella remained suppressed in soil from forest gaps compared to levels in intact forest understories while varying across sites and sampling dates. Pythium were infrequently detected likely because of soil handling effects. Expression of disease symptoms increased with increasing inoculum density for seedlings of P. serotina with each Pythium spp. having a similar effect on this species. Conversely, A. rubrum appeared resistant to the two species of Pythium. These results suggest that Pythium densities at sites where they were detected are sufficient to cause disease and possibly affect establishment of susceptible species like P. serotina. Because early seral environments have lower loads of the saprotrophic Mortierella, pathogen loads may follow a similar pattern, causing susceptible species to establish more frequently in those habitats than in late-seral forests. Forest disturbances that alter the disease landscape may provide an additional mechanism for explaining succession of temperate forests in addition to the shade-tolerance paradigm.

Reproductive losses caused by bovine viral diarrhea virus and leptospirosis.

PubMed

Grooms, Daniel L

2006-08-01

Bovine viral diarrhea virus and Leptospira spp. are two of the common pathogenic organisms responsible for reproductive losses in cattle worldwide. Both can be come endemic in herds resulting in chronic low-grade reproductive losses or they can be introduced into relatively naïve herds, resulting in substantial reproductive losses over a short period of time. Both organisms are a differential diagnoses for common reproductive losses that veterinarians investigate, including low conception rates and abortions.

Fungal Contaminants in Drinking Water Regulation? A Tale of Ecology, Exposure, Purification and Clinical Relevance

PubMed Central

Novak Babič, Monika; Gunde-Cimerman, Nina; Vargha, Márta; Tischner, Zsófia; Magyar, Donát; Veríssimo, Cristina; Sabino, Raquel; Viegas, Carla; Meyer, Wieland; Brandão, João

2017-01-01

Microbiological drinking water safety is traditionally monitored mainly by bacterial parameters that indicate faecal contamination. These parameters correlate with gastro-intestinal illness, despite the fact that viral agents, resulting from faecal contamination, are usually the cause. This leaves behind microbes that can cause illness other than gastro-intestinal and several emerging pathogens, disregarding non-endemic microbial contaminants and those with recent pathogenic activity reported. This white paper focuses on one group of contaminants known to cause allergies, opportunistic infections and intoxications: Fungi. It presents a review on their occurrence, ecology and physiology. Additionally, factors contributing to their presence in water distribution systems, as well as their effect on water quality are discussed. Presence of opportunistic and pathogenic fungi in drinking water can pose a health risk to consumers due to daily contact with water, via several exposure points, such as drinking and showering. The clinical relevance and influence on human health of the most common fungal contaminants in drinking water is discussed. Our goal with this paper is to place fungal contaminants on the roadmap of evidence based and emerging threats for drinking water quality safety regulations.

Analysis of a food-borne fungal pathogen outbreak: virulence and genome of a Mucor circinelloides isolate from yogurt.

PubMed

Lee, Soo Chan; Billmyre, R Blake; Li, Alicia; Carson, Sandra; Sykes, Sean M; Huh, Eun Young; Mieczkowski, Piotr; Ko, Dennis C; Cuomo, Christina A; Heitman, Joseph

2014-07-08

Food-borne pathogens are ongoing problems, and new pathogens are emerging. The impact of fungi, however, is largely underestimated. Recently, commercial yogurts contaminated with Mucor circinelloides were sold, and >200 consumers became ill with nausea, vomiting, and diarrhea. Mucoralean fungi cause the fatal fungal infection mucormycosis, whose incidence has been continuously increasing. In this study, we isolated an M. circinelloides strain from a yogurt container, and multilocus sequence typing identified the strain as Mucor circinelloides f. circinelloides. M. circinelloides f. circinelloides is the most virulent M. circinelloides subspecies and is commonly associated with human infections, whereas M. circinelloides f. lusitanicus and M. circinelloides f. griseocyanus are less common causes of infection. Whole-genome analysis of the yogurt isolate confirmed it as being close to the M. circinelloides f. circinelloides subgroup, with a higher percentage of divergence with the M. circinelloides f. lusitanicus subgroup. In mating assays, the yogurt isolate formed sexual zygospores with the (-) M. circinelloides f. circinelloides tester strain, which is congruent with its sex locus encoding SexP, the (+) mating type sex determinant. The yogurt isolate was virulent in murine and wax moth larva host systems. In a murine gastromucormycosis model, Mucor was recovered from fecal samples of infected mice for up to 10 days, indicating that Mucor can survive transit through the GI tract. In interactions with human immune cells, M. circinelloides f. lusitanicus induced proinflammatory cytokines but M. circinelloides f. circinelloides did not, which may explain the different levels of virulence in mammalian hosts. This study demonstrates that M. circinelloides can spoil food products and cause gastrointestinal illness in consumers and may pose a particular risk to immunocompromised patients. Importance: The U.S. FDA reported that yogurt products were contaminated with M. circinelloides, a mucoralean fungal pathogen, and >200 consumers complained of symptoms, including vomiting, nausea, and diarrhea. The manufacturer voluntarily withdrew the affected yogurt products from the market. Compared to other food-borne pathogens, including bacteria, viruses, and parasites, less focus has been placed on the risk of fungal pathogens. This study evaluates the potential risk from the food-borne fungal pathogen M. circinelloides that was isolated from the contaminated commercial yogurt. We successfully cultured an M. circinelloides isolate and found that the isolate belongs to the species M. circinelloides f. circinelloides, which is often associated with human infections. In murine and insect host models, the isolate was virulent. While information disseminated in the popular press would suggest this fungal contaminant poses little or no risk to consumers, our results show instead that it is capable of causing significant infections in animals. Copyright © 2014 Lee et al.

Computational approaches for discovery of common immunomodulators in fungal infections: towards broad-spectrum immunotherapeutic interventions.

PubMed

Kidane, Yared H; Lawrence, Christopher; Murali, T M

2013-10-07

Fungi are the second most abundant type of human pathogens. Invasive fungal pathogens are leading causes of life-threatening infections in clinical settings. Toxicity to the host and drug-resistance are two major deleterious issues associated with existing antifungal agents. Increasing a host's tolerance and/or immunity to fungal pathogens has potential to alleviate these problems. A host's tolerance may be improved by modulating the immune system such that it responds more rapidly and robustly in all facets, ranging from the recognition of pathogens to their clearance from the host. An understanding of biological processes and genes that are perturbed during attempted fungal exposure, colonization, and/or invasion will help guide the identification of endogenous immunomodulators and/or small molecules that activate host-immune responses such as specialized adjuvants. In this study, we present computational techniques and approaches using publicly available transcriptional data sets, to predict immunomodulators that may act against multiple fungal pathogens. Our study analyzed data sets derived from host cells exposed to five fungal pathogens, namely, Alternaria alternata, Aspergillus fumigatus, Candida albicans, Pneumocystis jirovecii, and Stachybotrys chartarum. We observed statistically significant associations between host responses to A. fumigatus and C. albicans. Our analysis identified biological processes that were consistently perturbed by these two pathogens. These processes contained both immune response-inducing genes such as MALT1, SERPINE1, ICAM1, and IL8, and immune response-repressing genes such as DUSP8, DUSP6, and SPRED2. We hypothesize that these genes belong to a pool of common immunomodulators that can potentially be activated or suppressed (agonized or antagonized) in order to render the host more tolerant to infections caused by A. fumigatus and C. albicans. Our computational approaches and methodologies described here can now be applied to newly generated or expanded data sets for further elucidation of additional drug targets. Moreover, identified immunomodulators may be used to generate experimentally testable hypotheses that could help in the discovery of broad-spectrum immunotherapeutic interventions. All of our results are available at the following supplementary website: http://bioinformatics.cs.vt.edu/~murali/supplements/2013-kidane-bmc.

Computational approaches for discovery of common immunomodulators in fungal infections: towards broad-spectrum immunotherapeutic interventions

PubMed Central

2013-01-01

Background Fungi are the second most abundant type of human pathogens. Invasive fungal pathogens are leading causes of life-threatening infections in clinical settings. Toxicity to the host and drug-resistance are two major deleterious issues associated with existing antifungal agents. Increasing a host’s tolerance and/or immunity to fungal pathogens has potential to alleviate these problems. A host’s tolerance may be improved by modulating the immune system such that it responds more rapidly and robustly in all facets, ranging from the recognition of pathogens to their clearance from the host. An understanding of biological processes and genes that are perturbed during attempted fungal exposure, colonization, and/or invasion will help guide the identification of endogenous immunomodulators and/or small molecules that activate host-immune responses such as specialized adjuvants. Results In this study, we present computational techniques and approaches using publicly available transcriptional data sets, to predict immunomodulators that may act against multiple fungal pathogens. Our study analyzed data sets derived from host cells exposed to five fungal pathogens, namely, Alternaria alternata, Aspergillus fumigatus, Candida albicans, Pneumocystis jirovecii, and Stachybotrys chartarum. We observed statistically significant associations between host responses to A. fumigatus and C. albicans. Our analysis identified biological processes that were consistently perturbed by these two pathogens. These processes contained both immune response-inducing genes such as MALT1, SERPINE1, ICAM1, and IL8, and immune response-repressing genes such as DUSP8, DUSP6, and SPRED2. We hypothesize that these genes belong to a pool of common immunomodulators that can potentially be activated or suppressed (agonized or antagonized) in order to render the host more tolerant to infections caused by A. fumigatus and C. albicans. Conclusions Our computational approaches and methodologies described here can now be applied to newly generated or expanded data sets for further elucidation of additional drug targets. Moreover, identified immunomodulators may be used to generate experimentally testable hypotheses that could help in the discovery of broad-spectrum immunotherapeutic interventions. All of our results are available at the following supplementary website: http://bioinformatics.cs.vt.edu/~murali/supplements/2013-kidane-bmc PMID:24099000

Influence of Varroa mite (Varroa destructor) infestation levels and management practices on insecticide sensitivity in the honey bee (Apis mellifera)

USDA-ARS?s Scientific Manuscript database

Because Varroa mites may cause devastating losses of honey bees through direct feeding, transmitting diseases, and increasing pathogen susceptibility, chemical and mechanical practices commonly are used to reduce mite infestation. While miticide applications are typically the most consistent and eff...

H9N2 avian influenza transmission and antigenicity

USDA-ARS?s Scientific Manuscript database

Low pathogenic H9N2 avian influenza has become endemic in parts of Asia, the Middle East and North Africa causing respiratory disease with occasional mortality. The use of vaccination has become common to try and control the clinical disease, but vaccination has not been shown to be an effective er...

Description of microsporidia in simulids: molecular and morphological characterization of microsporidia in the larvae of Simulium pertinax Kollar (Diptera: Simuliidae)

USDA-ARS?s Scientific Manuscript database

Microsporidia constitute the most common black fl y pathogens, although the species’ diversity, seasonal occurrence and transmission mechanisms remain poorly understood. Infections by this agent are often chronic and non-lethal, but they can cause reduced fecundity and decreased longevity. The objec...

Influence of weed species and time of glyphosate application on Rhizoctonia root rot of barley

USDA-ARS?s Scientific Manuscript database

Rhizoctonia solani AG-8 causes root disease in wheat, barley, canola and other small grains in the dryland inland Pacific Northwest. The pathogen survives between crops on roots of volunteers and grassy weeds. Destroying this green bridge with herbicides such as glyphosate is a common tactic to cont...

Blue mold to genomics and beyond: Insights into the biology and virulence of phytopathogenic Penicillium species

USDA-ARS?s Scientific Manuscript database

Pomes, mainly apples and pears, are economically important fruits produced and consumed worldwide. The United States is the second largest producer of pome fruit in the world behind China. Penicillium expansum and other Penicillium spp. are the most common fungal plant pathogens that cause blue mold...

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.

Pathogenicity of fumonisin-producing and nonproducing strains of Aspergillus species in section Nigri to maize ears and seedlings

USDA-ARS?s Scientific Manuscript database

Species of Aspergillus section Nigri are commonly associated with maize kernels, and some strains can produce fumonisin mycotoxins. However, there is little information about the extent to which these fungi contribute to fumonisin contamination in grain, the damage they cause to maize ears, or their...

Rothia mucilaginosa Prosthetic Device Infections: a Case of Prosthetic Valve Endocarditis

PubMed Central

Tokarczyk, Mindy J.; Jungkind, Donald; DeSimone, Joseph A.

2013-01-01

Rothia mucilaginosa is increasingly recognized as an emerging opportunistic pathogen associated with prosthetic device infections. Infective endocarditis is one of the most common clinical presentations. We report a case of R. mucilaginosa prosthetic valve endocarditis and review the literature of prosthetic device infections caused by this organism. PMID:23467598

Complete genome sequence of Campylobacter jejuni YH001 from beef liver which contains a novel plasmid

USDA-ARS?s Scientific Manuscript database

Campylobacter jejuni is an important foodborne pathogen that causes gastroenteritis in humans and is commonly found in poultry and meat products. Here, we report the complete genome sequence of a Campylobacter jejuni strain recently isolated from retail beef liver. The genome size was 1,712,361 bp, ...

Comparative quantification of Campylobacter jejuni from environmental samples using traditional and molecular biological techniques

USDA-ARS?s Scientific Manuscript database

Campylobacter jejuni (C. jejuni) is one of the most common causes of gastroenteritis in the world. Given the potential risks to human, animal and environmental health the development and optimization of methods to quantify this important pathogen in environmental samples is essential. Two of the mos...

[Bacterial biofilm as a cause of urinary tract infection--pathogens, methods of prevention and eradication].

PubMed

Ostrowska, Kinga; Strzelczyk, Aleksandra; Różalski, Antoni; Stączek, Paweł

2013-10-25

Urinary tract infections (UTI) are one of the common chronic and recurrent bacterial infections. Uropathogens which are able to form biofilm constitute a major etiological factor in UTI, especially among elder patients who are subject to long-term catheterization. It is caused by the capacity of the microorganisms for efficient and permanent colonization of tissues and also adhesion to diverse polymers used for urological catheter production such as propylene, polystyrene, silicone, polyvinyl chloride or silicone coated latex. Antibiotic therapy is the most common treatment for UTI. Fluoroquinolones, nitrofurans, beta-lactams, aminoglycosides, trimethoprim and sulfonamides are used predominantly. However, the biofilm due to its complex structure constitutes an effective barrier to the antibiotics used in the treatment of urinary tract infections. In addition, the growing number of multidrug resistant strains limits the usage of many of the currently available chemotherapeutic agents. Therefore, it seems important to search for new methods of treatment such as coating of catheters with non-pathogenic E. coli strains, the design of vaccines against fimbrial adhesive proteins of the bacterial cells or the use of bacteriophages.

TDP-43 Is Not a Common Cause of Sporadic Amyotrophic Lateral Sclerosis

PubMed Central

Guerreiro, Rita J.; Schymick, Jennifer C.; Crews, Cynthia; Singleton, Andrew; Hardy, John; Traynor, Bryan J.

2008-01-01

Background TAR DNA binding protein, encoded by TARDBP, was shown to be a central component of ubiquitin-positive, tau-negative inclusions in frontotemporal lobar degeneration (FTLD-U) and amyotrophic lateral sclerosis (ALS). Recently, mutations in TARDBP have been linked to familial and sporadic ALS. Methodology/Principal Findings To further examine the frequency of mutations in TARDBP in sporadic ALS, 279 ALS cases and 806 neurologically normal control individuals of European descent were screened for sequence variants, copy number variants, genetic and haplotype association with disease. An additional 173 African samples from the Human Gene Diversity Panel were sequenced as this population had the highest likelihood of finding changes. No mutations were found in the ALS cases. Several genetic variants were identified in controls, which were considered as non-pathogenic changes. Furthermore, pathogenic structural variants were not observed in the cases and there was no genetic or haplotype association with disease status across the TARDBP locus. Conclusions Our data indicate that genetic variation in TARDBP is not a common cause of sporadic ALS in North American. PMID:18545701

Chitayat-Hall and Schaaf-Yang syndromes:a common aetiology: expanding the phenotype of MAGEL2-related disorders.

PubMed

Jobling, Rebekah; Stavropoulos, Dimitri James; Marshall, Christian R; Cytrynbaum, Cheryl; Axford, Michelle M; Londero, Vanessa; Moalem, Sharon; Orr, Jennifer; Rossignol, Francis; Lopes, Fatima Daniela; Gauthier, Julie; Alos, Nathalie; Rupps, Rosemarie; McKinnon, Margaret; Adam, Shelin; Nowaczyk, Malgorzata J M; Walker, Susan; Scherer, Stephen W; Nassif, Christina; Hamdan, Fadi F; Deal, Cheri L; Soucy, Jean-François; Weksberg, Rosanna; Macleod, Patrick; Michaud, Jacques L; Chitayat, David

2018-05-01

Chitayat-Hall syndrome, initially described in 1990, is a rare condition characterised by distal arthrogryposis, intellectual disability, dysmorphic features and hypopituitarism, in particular growth hormone deficiency. The genetic aetiology has not been identified. We identified three unrelated families with a total of six affected patients with the clinical manifestations of Chitayat-Hall syndrome. Through whole exome or whole genome sequencing, pathogenic variants in the MAGEL2 gene were identified in all affected patients. All disease-causing sequence variants detected are predicted to result in a truncated protein, including one complex variant that comprised a deletion and inversion. Chitayat-Hall syndrome is caused by pathogenic variants in MAGEL2 and shares a common aetiology with the recently described Schaaf-Yang syndrome. The phenotype of MAGEL2 -related disorders is expanded to include growth hormone deficiency as an important and treatable complication. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

A MAYAN FOUNDER MUTATION IS A COMMON CAUSE OF DEAFNESS IN GUATEMALA

PubMed Central

Carranza, Claudia; Menendez, Ibis; Herrera, Mariana; Castellanos, Patricia; Amado, Carlos; Maldonado, Fabiola; Rosales, Luisa; Escobar, Nancy; Guerra, Mariela; Alvarez, Darwin; Foster, Joseph; Guo, Shengru; Blanton, Susan H.; Bademci, Guney; Tekin, Mustafa

2017-01-01

SUMMARY Over 5% of the world population have varying degrees of hearing loss. Mutations in GJB2 are the most common cause of autosomal recessive non-syndromic hearing loss (NSHL) in many populations. The frequency and type of mutations are influenced by ethnicity. Guatemala is a multi-ethnic country with four major populations: Maya, Ladino, Xinca, and Garifuna. To determine the mutation profile of GJB2 in a NSHL population from Guatemala, we sequenced both exons of GJB2 in 133 unrelated families. A total of six pathogenic variants were detected. The most frequent pathogenic variant is c.131G>A (p.Trp44*) detected in 21 of 266 alleles. We show that c.131G>A is associated with a conserved haplotype in Guatemala suggesting a single founder. The majority of Mayan population lives in the west region of the country from where all c.131G>A carriers originated. Further analysis of genome-wide variation of individuals carrying the c.131G>A mutation compared to those of Native American, European, and African populations shows a close match with the Mayan population. PMID:26346709

Standard methods for fungal brood disease research

PubMed Central

Jensen, Annette Bruun; Aronstein, Kathrine; Flores, José Manuel; Vojvodic, Svjetlana; Palacio, María Alejandra; Spivak, Marla

2013-01-01

Summary Chalkbrood and stonebrood are two fungal diseases associated with honey bee brood. Chalkbrood, caused by Ascosphaera apis, is a common and widespread disease that can result in severe reduction of emerging worker bees and thus overall colony productivity. Stonebrood is caused by Aspergillus spp. that are rarely observed, so the impact on colony health is not very well understood. A major concern with the presence of Aspergillus in honey bees is the production of airborne conidia, which can lead to allergic bronchopulmonary aspergillosis, pulmonary aspergilloma, or even invasive aspergillosis in lung tissues upon inhalation by humans. In the current chapter we describe the honey bee disease symptoms of these fungal pathogens. In addition, we provide research methodologies and protocols for isolating and culturing, in vivo and in vitro assays that are commonly used to study these host pathogen interactions. We give guidelines on the preferred methods used in current research and the application of molecular techniques. We have added photographs, drawings and illustrations to assist bee-extension personnel and bee scientists in the control of these two diseases. PMID:24198438

Structured literature review of responses of cattle to viral and bacterial pathogens causing bovine respiratory disease complex.

PubMed

Grissett, G P; White, B J; Larson, R L

2015-01-01

Bovine respiratory disease (BRD) is an economically important disease of cattle and continues to be an intensely studied topic. However, literature summarizing the time between pathogen exposure and clinical signs, shedding, and seroconversion is minimal. A structured literature review of the published literature was performed to determine cattle responses (time from pathogen exposure to clinical signs, shedding, and seroconversion) in challenge models using common BRD viral and bacterial pathogens. After review a descriptive analysis of published studies using common BRD pathogen challenge studies was performed. Inclusion criteria were single pathogen challenge studies with no treatment or vaccination evaluating outcomes of interest: clinical signs, shedding, and seroconversion. Pathogens of interest included: bovine viral diarrhea virus (BVDV), bovine herpesvirus type 1 (BHV-1), parainfluenza-3 virus, bovine respiratory syncytial virus, Mannheimia haemolytica, Mycoplasma bovis, Pastuerella multocida, and Histophilus somni. Thirty-five studies and 64 trials were included for analysis. The median days to the resolution of clinical signs after BVDV challenge was 15 and shedding was not detected on day 12 postchallenge. Resolution of BHV-1 shedding resolved on day 12 and clinical signs on day 12 postchallenge. Bovine respiratory syncytial virus ceased shedding on day 9 and median time to resolution of clinical signs was on day 12 postchallenge. M. haemolytica resolved clinical signs 8 days postchallenge. This literature review and descriptive analysis can serve as a resource to assist in designing challenge model studies and potentially aid in estimation of duration of clinical disease and shedding after natural pathogen exposure. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Predators indirectly control vector-borne disease: linking predator-prey and host-pathogen models.

PubMed

Moore, Sean M; Borer, Elizabeth T; Hosseini, Parviez R

2010-01-06

Pathogens transmitted by arthropod vectors are common in human populations, agricultural systems and natural communities. Transmission of these vector-borne pathogens depends on the population dynamics of the vector species as well as its interactions with other species within the community. In particular, predation may be sufficient to control pathogen prevalence indirectly via the vector. To examine the indirect effect of predators on vectored-pathogen dynamics, we developed a theoretical model that integrates predator-prey and host-pathogen theory. We used this model to determine whether predation can prevent pathogen persistence or alter the stability of host-pathogen dynamics. We found that, in the absence of predation, pathogen prevalence in the host increases with vector fecundity, whereas predation on the vector causes pathogen prevalence to decline, or even become extinct, with increasing vector fecundity. We also found that predation on a vector may drastically slow the initial spread of a pathogen. The predator can increase host abundance indirectly by reducing or eliminating infection in the host population. These results highlight the importance of studying interactions that, within the greater community, may alter our predictions when studying disease dynamics. From an applied perspective, these results also suggest situations where an introduced predator or the natural enemies of a vector may slow the rate of spread of an emerging vector-borne pathogen.

Enhancing pathogen identification in patients with meningitis and a negative Gram stain using the BioFire FilmArray(®) Meningitis/Encephalitis panel.

PubMed

Wootton, Susan H; Aguilera, Elizabeth; Salazar, Lucrecia; Hemmert, Andrew C; Hasbun, Rodrigo

2016-04-21

Meningitis with a negative cerebrospinal (CSF) Gram stain represents a diagnostic and therapeutic challenge. The purpose of our study was to evaluate the performance of the BioFire FilmArray(®) Meningitis/Encephalitis (FA ME) panel in patients presenting with community-acquired meningitis with a negative Gram stain. CSF from 48 patients with community-acquired meningitis with a negative Gram stain admitted to four hospitals in Houston, TX underwent additional testing by the FA ME. FA ME results were compared to results obtained as part of routine evaluation. The panel detected pathogens not previously identified in 11 (22.9 %) of 48, but did not detect pathogens identified by standard technique (West Nile virus, Histoplasma) in 5 (15.2 %) patients. Rapid testing for the most common pathogens causing meningitis will aid in the diagnosis and treatment of patients with meningitis.

Increased BRAF Heterodimerization Is the Common Pathogenic Mechanism for Noonan Syndrome-Associated RAF1 Mutants

PubMed Central

Wu, Xue; Yin, Jiani; Simpson, Jeremy; Kim, Kyoung-Han; Gu, Shengqing; Hong, Jenny H.; Bayliss, Peter; Backx, Peter H.

2012-01-01

Noonan syndrome (NS) is a relatively common autosomal dominant disorder characterized by congenital heart defects, short stature, and facial dysmorphia. NS is caused by germ line mutations in several components of the RAS–RAF–MEK–extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) pathway, including both kinase-activating and kinase-impaired alleles of RAF1 (∼3 to 5%), which encodes a serine-threonine kinase for MEK1/2. To investigate how kinase-impaired RAF1 mutants cause NS, we generated knock-in mice expressing Raf1D486N. Raf1D486N/+ (here D486N/+) female mice exhibited a mild growth defect. Male and female D486N/D486N mice developed concentric cardiac hypertrophy and incompletely penetrant, but severe, growth defects. Remarkably, Mek/Erk activation was enhanced in Raf1D486N-expressing cells compared with controls. RAF1D486N, as well as other kinase-impaired RAF1 mutants, showed increased heterodimerization with BRAF, which was necessary and sufficient to promote increased MEK/ERK activation. Furthermore, kinase-activating RAF1 mutants also required heterodimerization to enhance MEK/ERK activation. Our results suggest that an increased heterodimerization ability is the common pathogenic mechanism for NS-associated RAF1 mutations. PMID:22826437

Antibiotic sensitivity pattern of bacteria from diabetic foot infections Haji Adam Malik central general hospital

NASA Astrophysics Data System (ADS)

Bulolo, B. A.; Pase, M. A.; Ginting, F.

2018-03-01

Increasing rate of Diabetic Foot Infections (DFIs) caused by multi-drug-resistance pathogens plays a huge role in the duration of hospitalization, morbidity, and mortality of diabetic patients. The aim of the study is to assess the antibiotic sensitivity pattern of bacteria in DFIs and causative microorganisms. Using cross-sectional retrospective study, data were collected from medical records of DFIs patients previously hospitalized atHaji Adam Malik Hospital, Medan from January to July 2017. 33 patients met the criteria and got enrolled in the study. The classification of DFIs was evaluated according to Wagner’s Classification. Evaluation of antibiotic sensitivity and identification of causative microorganisms were performed in standard microbiologic methods. The most common grade of DFIs was Grade-4 (48.5%), followed by Grade-3 (39.4%) and Grade-5 (9.1%). A total of 12 pathogens were identified. The most common infecting microorganism isolated on pus cultures was Klebsiella pneumonia (33.3%), followed by Escherichia coli (24.2%), Acinetobacter baumanni (12.1%), and Staphylococcus aureus (9.1%). Frequent susceptible antibiotics were Amikacin (88.8%), Imipenem (87%), Meropenem (84.6%), Erythromycin (75%), and Cefoperazone/Sulbactam (68.9%). DFIs are polymicrobial infections in this study K. pneumonia was the most common cause microorganism.

[Etiological and molecular characteristics of diarrhea caused Proteus mirabilis].

PubMed

Shi, Xiaolu; Hu, Qinghua; Lin, Yiman; Qiu, Yaqun; Li, Yinghui; Jiang, Min; Chen, Qiongcheng

2014-06-01

To analyze the etiological characteristics, virulence genes and plasmids that carrying diarrhea-causing Proteus mirabilis and to assess their relationship with drug resistance and pathogenicity. Proteus mirabilis coming from six different sources (food poisoning, external environment and healthy people) were analyzed biochemically, on related susceptibility and pulsed-field gel electrophoresis (PFGE). Virulence genes were detected by PCR. Plasmids were extracted and sequenced after gel electrophoresis purification. The biochemical characteristics of Proteus mirabilis from different sources seemed basically the same, and each of them showed having common virulence genes, as ureC, rsmA, hpmA and zapA. However, the PFGE patterns and susceptibility of these strains were different, so as the plasmids that they carried. Plasmid that presented in the sequenced strain showed that the 2 683 bp length plasmid encodes qnrD gene was associated with the quinolone resistance. Etiological characteristics and molecular characteristics of Proteus mirabilis gathered from different sources, were analyzed. Results indicated that traditional biochemical analysis and common virulence gene identification might be able to distinguish the strains with different sources. However, PFGE and plasmids analysis could distinguish the sources of strains and to identify those plasmids that commonly carried by the drug-resistant strains. These findings also provided theoretical basis for further study on the nature of resistance and pathogenicity in Proteus mirabilis.

The Human Stomach in Health and Disease: Infection Strategies by Helicobacter pylori.

PubMed

Robinson, Karen; Letley, Darren P; Kaneko, Kazuyo

2017-01-01

Helicobacter pylori is a bacterial pathogen which commonly colonizes the human gastric mucosa from early childhood and persists throughout life. In the vast majority of cases, the infection is asymptomatic. H. pylori is the leading cause of peptic ulcer disease and gastric cancer, however, and these outcomes occur in 10-15% of those infected. Gastric adenocarcinoma is the third most common cause of cancer-associated death, and peptic ulcer disease is a significant cause of morbidity. Disease risk is related to the interplay of numerous bacterial host and environmental factors, many of which influence chronic inflammation and damage to the gastric mucosa. This chapter summarizes what is known about health and disease in H. pylori infection, and highlights the need for additional research in this area.

Comparative Genomic Analysis of Pathogenic and Probiotic Enterococcus faecalis Isolates, and Their Transcriptional Responses to Growth in Human Urine

PubMed Central

Snipen, Lars; Nes, Ingolf F.; Brede, Dag A.

2010-01-01

Urinary tract infection (UTI) is the most common infection caused by enterococci, and Enterococcus faecalis accounts for the majority of enterococcal infections. Although a number of virulence related traits have been established, no comprehensive genomic or transcriptomic studies have been conducted to investigate how to distinguish pathogenic from non-pathogenic E. faecalis in their ability to cause UTI. In order to identify potential genetic traits or gene regulatory features that distinguish pathogenic from non-pathogenic E. faecalis with respect to UTI, we have performed comparative genomic analysis, and investigated growth capacity and transcriptome profiling in human urine in vitro. Six strains of different origins were cultivated and all grew readily in human urine. The three strains chosen for transcriptional analysis showed an overall similar response with respect to energy and nitrogen metabolism, stress mechanism, cell envelope modifications, and trace metal acquisition. Our results suggest that citrate and aspartate are significant for growth of E. faecalis in human urine, and manganese appear to be a limiting factor. The majority of virulence factors were either not differentially regulated or down-regulated. Notably, a significant up-regulation of genes involved in biofilm formation was observed. Strains from different origins have similar capacity to grow in human urine. The overall similar transcriptional responses between the two pathogenic and the probiotic strain suggest that the pathogenic potential of a certain E. faecalis strain may to a great extent be determined by presence of fitness and virulence factors, rather than the level of expression of such traits. PMID:20824220

Cln1 gene disruption in mice reveals a common pathogenic link between two of the most lethal childhood neurodegenerative lysosomal storage disorders.

PubMed

Chandra, Goutam; Bagh, Maria B; Peng, Shiyong; Saha, Arjun; Sarkar, Chinmoy; Moralle, Matthew; Zhang, Zhongjian; Mukherjee, Anil B

2015-10-01

Neurodegeneration is a devastating manifestation in the majority of >50 lysosomal storage disorders (LSDs). Neuronal ceroid lipofuscinoses (NCLs) are the most common childhood neurodegenerative LSDs. Mutations in 13 different genes (called CLNs) underlie various types of NCLs, of which the infantile NCL (INCL) and congenital NCL (CNCL) are the most lethal. Although inactivating mutations in the CLN1 gene encoding palmitoyl-protein thioesterase-1 (PPT1) cause INCL, those in the CLN10 gene encoding cathepsin D (CD) underlie CNCL. PPT1 is a lysosomal thioesterase that cleaves the thioester linkage in S-acylated proteins required for their degradation by lysosomal hydrolases like CD. Thus, PPT1 deficiency causes lysosomal accumulation of these lipidated proteins (major constituents of ceroid) leading to INCL. We sought to determine whether there is a common pathogenic link between INCL and CNCL. Using biochemical, histological and confocal microscopic analyses of brain tissues and cells from Cln1(-/-) mice that mimic INCL, we uncovered that Cln10/CD is overexpressed. Although synthesized in the endoplasmic reticulum, the CD-precursor protein (pro-CD) is transported through endosome to the lysosome where it is proteolytically processed to enzymatically active-CD. We found that despite Cln10 overexpression, the maturation of pro-CD to enzymatically active-CD in lysosome was disrupted. This defect impaired lysosomal degradative function causing accumulation of undegraded cargo in lysosome leading to INCL. Notably, treatment of intact Cln1(-/-) mice as well as cultured brain cells derived from these animals with a thioesterase-mimetic small molecule, N-tert-butyl-hydroxylamine, ameliorated the CD-processing defect. Our findings are significant in that they define a pathway in which Cln1 mutations disrupt the maturation of a major degradative enzyme in lysosome contributing to neuropathology in INCL and suggest that lysosomal CD deficiency is a common pathogenic link between INCL and CNCL. Published by Oxford University Press 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Rodents as potential couriers for bioterrorism agents.

PubMed

Lõhmus, Mare; Janse, Ingmar; van de Goot, Frank; van Rotterdam, Bart J

2013-09-01

Many pathogens that can cause major public health, economic, and social damage are relatively easily accessible and could be used as biological weapons. Wildlife is a natural reservoir for many potential bioterrorism agents, and, as history has shown, eliminating a pathogen that has dispersed among wild fauna can be extremely challenging. Since a number of wild rodent species live close to humans, rodents constitute a vector for pathogens to circulate among wildlife, domestic animals, and humans. This article reviews the possible consequences of a deliberate spread of rodentborne pathogens. It is relatively easy to infect wild rodents with certain pathogens or to release infected rodents, and the action would be difficult to trace. Rodents can also function as reservoirs for diseases that have been spread during a bioterrorism attack and cause recurring disease outbreaks. As rats and mice are common in both urban and rural settlements, deliberately released rodentborne infections have the capacity to spread very rapidly. The majority of pathogens that are listed as potential agents of bioterrorism by the Centers for Disease Control and Prevention and the National Institute of Allergy and Infectious Diseases exploit rodents as vectors or reservoirs. In addition to zoonotic diseases, deliberately released rodentborne epizootics can have serious economic consequences for society, for example, in the area of international trade restrictions. The ability to rapidly detect introduced diseases and effectively communicate with the public in crisis situations enables a quick response and is essential for successful and cost-effective disease control.

Recovery Estimation of Dried Foodborne Pathogens Is Directly Related to Rehydration Kinetics

PubMed Central

Lang, Emilie; Zoz, Fiona; Iaconelli, Cyril; Guyot, Stéphane; Alvarez-Martin, Pablo; Beney, Laurent; Perrier-Cornet, Jean-Marie; Gervais, Patrick

2016-01-01

Drying is a common process which is used to preserve food products and technological microorganisms, but which is deleterious for the cells. The aim of this study is to differentiate the effects of drying alone from the effects of the successive and necessary rehydration. Rehydration of dried bacteria is a critical step already studied in starter culture but not for different kinetics and not for pathogens. In the present study, the influence of rehydration kinetics was investigated for three foodborne pathogens involved in neonatal diseases caused by the consumption of rehydrated milk powder: Salmonella enterica subsp. enterica serovar Typhimurium, Salmonella enterica subsp. enterica serovar Senftenberg and Cronobacter sakazakii. Bacteria were dried in controlled relative humidity atmospheres and then rehydrated using different methods. Our results showed that the survival of the three pathogens was strongly related to rehydration kinetics. Consequently, rehydration is an important step to consider during food safety assessment or during studies of dried foodborne pathogens. Also, it has to be considered with more attention in consumers’ homes during the preparation of food, like powdered infant formula, to avoid pathogens recovery. PMID:27494169

Recurrent vaginal discharge in children.

PubMed

McGreal, Sharon; Wood, Paul

2013-08-01

Childhood vaginal discharge remains a frequent reason for referral from primary to secondary care. The Pediatric and Adolescent Gynecology (PAG) service at Kettering General Hospital was established in 1993 and provides a specialized service that meets the needs of children with gynaecological conditions. To investigate recurrent vaginal discharge noting symptomatology, defining pathogens, common and rarer causes, exploring management regimes, and any changes in practice over time. Retrospective review spanning 15 years identifying prepubertal children attending the outpatient PAG clinic with recurrent vaginal discharge. We reviewed the medical notes individually. 110 patients were identified; 85% were referred from primary care. The age distribution was bimodal at four and eight years. Thirty-five percent of our patients were discharged after the initial consultation. The commonest cause of discharge was vulvovaginitis (82%). Other important causes included suspected sexual abuse (5%), foreign body (3%), labial adhesions (3%), vaginal agenesis (2%). 35% of patients were admitted for vaginoscopy. Vaginal discharge is the most common gynecological symptom in prepubertal girls and can cause repeated clinical episodes. Vulvovaginitis is the most common cause and often responds to simple hygiene measures. Awareness of the less common causes of vaginal discharge is essential. Copyright © 2013 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

Human Pathogen Shown to Cause Disease in the Threatened Eklhorn Coral Acropora palmata

PubMed Central

Sutherland, Kathryn Patterson; Shaban, Sameera; Joyner, Jessica L.; Porter, James W.; Lipp, Erin K.

2011-01-01

Coral reefs are in severe decline. Infections by the human pathogen Serratia marcescens have contributed to precipitous losses in the common Caribbean elkhorn coral, Acropora palmata, culminating in its listing under the United States Endangered Species Act. During a 2003 outbreak of this coral disease, called acroporid serratiosis (APS), a unique strain of the pathogen, Serratia marcescens strain PDR60, was identified from diseased A. palmata, human wastewater, the non-host coral Siderastrea siderea and the corallivorous snail Coralliophila abbreviata. In order to examine humans as a source and other marine invertebrates as vectors and/or reservoirs of the APS pathogen, challenge experiments were conducted with A. palmata maintained in closed aquaria to determine infectivity of strain PDR60 from reef and wastewater sources. Strain PDR60 from wastewater and diseased A. palmata caused disease signs in elkhorn coral in as little as four and five days, respectively, demonstrating that wastewater is a definitive source of APS and identifying human strain PDR60 as a coral pathogen through fulfillment of Koch's postulates. A. palmata inoculated with strain PDR60 from C. abbreviata showed limited virulence, with one of three inoculated fragments developing APS signs within 13 days. Strain PDR60 from non-host coral S. siderea showed a delayed pathogenic effect, with disease signs developing within an average of 20 days. These results suggest that C. abbreviata and non-host corals may function as reservoirs or vectors of the APS pathogen. Our results provide the first example of a marine “reverse zoonosis” involving the transmission of a human pathogen (S. marcescens) to a marine invertebrate (A. palmata). These findings underscore the interaction between public health practices and environmental health indices such as coral reef survival. PMID:21858132

Efficacy of a new pharmacokinetically enhanced formulation of amoxicillin/clavulanate (2000/125 mg) in adults with community-acquired pneumonia caused by Streptococcus pneumoniae, including penicillin-resistant strains.

PubMed

File, Thomas M; Garau, Javier; Jacobs, Michael R; Wynne, Brian; Twynholm, Monique; Berkowitz, Elchonon

2005-02-01

Community-acquired pneumonia (CAP) is a common respiratory illness, frequently caused by Streptococcus pneumoniae. The prevalence of S. pneumoniae resistance to common antimicrobials has increased over recent years. A new pharmacokinetically enhanced formulation of amoxicillin/clavulanate (2000/125 mg) has been developed, designed to combat infections caused by S. pneumoniae, including penicillin-resistant (PRSP, penicillin minimum inhibitory concentrations (MICs) >or=2mg/l) isolates, and those with elevated amoxicillin/clavulanic acid MICs, while maintaining coverage of beta-lactamase-producing pathogens. A pooled efficacy analysis of four randomized (1:1) and one non-comparative clinical trials of amoxicillin/clavulanate, 2000/125 mg, given twice daily, was conducted in adult patients with CAP. Comparator agents were conventional amoxicillin/clavulanate formulations. At follow-up (days 16-39), efficacy (eradication of the initial pathogen or clinical cure in patients for whom no repeat culture was performed) in patients with S. pneumoniae infection was 92.3% (274/297) for amoxicillin/clavulanate, 2000/125 mg and 85.2% (46/54) for comparators (P=0.11). Twenty-four of 25 PRSP-infected patients receiving amoxicillin/clavulanate, 2000/125 mg were treated successfully. Both amoxicillin/clavulanate, 2000/125 mg and comparators were well tolerated, with few patients withdrawing from the studies.

Molecular epidemiology of mastitis pathogens of dairy cattle and comparative relevance to humans.

PubMed

Zadoks, Ruth N; Middleton, John R; McDougall, Scott; Katholm, Jorgen; Schukken, Ynte H

2011-12-01

Mastitis, inflammation of the mammary gland, can be caused by a wide range of organisms, including gram-negative and gram-positive bacteria, mycoplasmas and algae. Many microbial species that are common causes of bovine mastitis, such as Escherichia coli, Klebsiella pneumoniae, Streptococcus agalactiae and Staphylococcus aureus also occur as commensals or pathogens of humans whereas other causative species, such as Streptococcus uberis, Streptococcus dysgalactiae subsp. dysgalactiae or Staphylococcus chromogenes, are almost exclusively found in animals. A wide range of molecular typing methods have been used in the past two decades to investigate the epidemiology of bovine mastitis at the subspecies level. These include comparative typing methods that are based on electrophoretic banding patterns, library typing methods that are based on the sequence of selected genes, virulence gene arrays and whole genome sequencing projects. The strain distribution of mastitis pathogens has been investigated within individual animals and across animals, herds, countries and host species, with consideration of the mammary gland, other animal or human body sites, and environmental sources. Molecular epidemiological studies have contributed considerably to our understanding of sources, transmission routes, and prognosis for many bovine mastitis pathogens and to our understanding of mechanisms of host-adaptation and disease causation. In this review, we summarize knowledge gleaned from two decades of molecular epidemiological studies of mastitis pathogens in dairy cattle and discuss aspects of comparative relevance to human medicine.

Gene flow in environmental Legionella pneumophila leads to genetic and pathogenic heterogeneity within a Legionnaires' disease outbreak.

PubMed

McAdam, Paul R; Vander Broek, Charles W; Lindsay, Diane S J; Ward, Melissa J; Hanson, Mary F; Gillies, Michael; Watson, Mick; Stevens, Joanne M; Edwards, Giles F; Fitzgerald, J Ross

2014-01-01

Legionnaires' disease is a severe form of pneumonia caused by the environmental bacterium Legionella pneumophila. Outbreaks commonly affect people with known risk factors, but the genetic and pathogenic complexity of L. pneumophila within an outbreak is not well understood. Here, we investigate the etiology of the major Legionnaires' disease outbreak that occurred in Edinburgh, UK, in 2012, by examining the evolutionary history, genome content, and virulence of L. pneumophila clinical isolates. Our high resolution genomic approach reveals that the outbreak was caused by multiple genetic subtypes of L. pneumophila, the majority of which had diversified from a single progenitor through mutation, recombination, and horizontal gene transfer within an environmental reservoir prior to release. In addition, we discover that some patients were infected with multiple L. pneumophila subtypes, a finding which can affect the certainty of source attribution. Importantly, variation in the complement of type IV secretion systems encoded by different genetic subtypes correlates with virulence in a Galleria mellonella model of infection, revealing variation in pathogenic potential among the outbreak source population of L. pneumophila. Taken together, our study indicates previously cryptic levels of pathogen heterogeneity within a Legionnaires' disease outbreak, a discovery that impacts on source attribution for future outbreak investigations. Furthermore, our data suggest that in addition to host immune status, pathogen diversity may be an important influence on the clinical outcome of individual outbreak infections.

Functions and origin of plasmids in Erwinia species that are pathogenic to or epiphytically associated with pome fruit trees.

PubMed

Llop, Pablo; Barbé, Silvia; López, María M

The genus Erwinia includes plant-associated pathogenic and non-pathogenic species. Among them, all species pathogenic to pome fruit trees ( E. amylovora, E. pyrifoliae, E. piriflorinigrans, Erwinia sp. from Japan) cause similar symptoms, but differ in their degrees of aggressiveness, i.e. in symptoms, host range or both. The presence of plasmids of similar size, in the range of 30 kb, is a common characteristic that they possess. Besides, they share some genetic content with high homology in several genes associated with exopolysaccharide production and hence, with virulence, as well as in some other genes. Knowledge of the content of these plasmids and comparative genetic analyses may provide interesting new clues to understanding the origin and evolution of these pathogens and the level of symptoms they produce. Furthermore, genetic similarities observed among some of the plasmids (and genomes) from the above indicated pathogenic species and E. tasmaniensis or E. billingiae , which are epiphytic on the same hosts, may reveal associations that could expose the mechanisms of origin of pathogens. A summary of the current information on their plasmids and the relationships among them is presented here.

Immune effects of the vaccine of live attenuated Aeromonas hydrophila screened by rifampicin on common carp (Cyprinus carpio L).

PubMed

Jiang, Xinyu; Zhang, Chao; Zhao, Yanjing; Kong, Xianghui; Pei, Chao; Li, Li; Nie, Guoxing; Li, Xuejun

2016-06-08

Aeromonas hydrophila, as a strong Gram-negative bacterium, can infect a wide range of freshwater fish, including common carp Cyprinus carpio, and cause the huge economic loss. To create the effective vaccine is the best way to control the outbreak of the disease caused by A. hydrophila. In this study, a live attenuated A. hydrophila strain, XX1LA, was screened from the pathogenic A. hydrophila strain XX1 cultured on medium containing the antibiotic rifampicin, which was used as a live attenuated vaccine candidate. The immune protection of XX1LA against the pathogen A. hydrophila in common carp was evaluated by the relative percent survival (RPS), the specific IgM antibody titers, serum lysozyme activity and the expression profiles of multiple immune-related genes at the different time points following immunization. The results showed that the variable up-regulations of the immune-related genes, such as the pro-inflammatory cytokine IL-1β, the chemokine IL-10 and IgM, were observed in spleen and liver of common carp injected in the vaccines with the formalin-killed A. hydrophila (FKA) and the live attenuated XX1LA. Specific antibody to A. hydrophila was found to gradually increase during 28 days post-vaccination (dpv), and the RPS (83.7%) in fish vaccinated with XX1LA, was significant higher than that (37.2%) in fish vaccinated with FKA (P<0.05) on Day 28 after challenged by pathogen. It was demonstrated that the remarkable immune protection presented in the group vaccinated with XX1LA. During the late stage of 4-week immunization phase, compared with FKA and the control, specific IgM antibody titers significantly increased (P<0.05) in the XX1LA group. The activity of the lysozyme in serum indicated no significant change among three groups. In summary, the live attenuated bacterial vaccine XX1LA, screened in this study, indicates the better protect effect on common carp against A. hydrophila, which can be applied in aquaculture of common carp to prevent from the disease outbreak in the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

First report of monomicrobial Candida parapsilosis necrotizing fasciitis.

PubMed

Gassiep, I; Douglas, J; Playford, E G

2016-10-01

Candida parapsilosis is an emerging pathogen worldwide. It commonly causes soft tissue infection; however, to our knowledge there has been no previous report of monomicrobial necrotizing soft tissue infection (NSTI) secondary to C. parapsilosis. We report the first case of NSTI caused by C. parapsilosis in an immunocompromised renal transplant patient, with the diagnosis proven both histologically and microbiologically. Our patient required aggressive surgical intervention and antifungal therapy, with postoperative survival at 90 days. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Antimicrobial property of zinc based nanoparticles

NASA Astrophysics Data System (ADS)

Chiriac, V.; Stratulat, D. N.; Calin, G.; Nichitus, S.; Burlui, V.; Stadoleanu, C.; Popa, M.; Popa, I. M.

2016-06-01

Pathogen bacteria strains with wide spectrum can cause serious infections with drastic damages on humans. There are studies reflecting antibacterial effect of nanoparticles type metal or metal oxides as an alternative or concurrent treatment to the diseases caused by infectious agents. Synthesised nanoparticles using different methods like sol-gel, hydrothermal or plant extraction were tested following well-established protocols with the regard to their antimicrobial activity. It was found that zinc based nanoparticles possess strong synergistic effect with commonly used antibiotics on infection tratment.

Campylobacter jejuni—An Emerging Foodborne Pathogen

PubMed Central

Stern, Norman J.; Fields, Patricia I.; Swerdlow, David L.

1999-01-01

Campylobacter jejuni is the most commonly reported bacterial cause of foodborne infection in the United States. Adding to the human and economic costs are chronic sequelae associated with C. jejuni infection—Guillian-Barré syndrome and reactive arthritis. In addition, an increasing proportion of human infections caused by C. jejuni are resistant to antimicrobial therapy. Mishandling of raw poultry and consumption of undercooked poultry are the major risk factors for human campylobacteriosis. Efforts to prevent human illness are needed throughout each link in the food chain. PMID:10081669

First Human Case of Meningitis and Sepsis in a Child Caused by Actinobacillus suis or Actinobacillus equuli.

PubMed

Montagnani, Carlotta; Pecile, Patrizia; Moriondo, Maria; Petricci, Patrizia; Becciani, Sabrina; Chiappini, Elena; Indolfi, Giuseppe; Rossolini, Gian Maria; Azzari, Chiara; de Martino, Maurizio; Galli, Luisa

2015-06-01

We report the first human case of meningitis and sepsis caused in a child by Actinobacillus suis or A. equuli, a common opportunistic pathogen of swine or horses, respectively. Identification was performed by matrix-assisted laser desorption ionization-time of flight mass spectrometry and real-time PCR assay. A previous visit to a farm was suspected as the source of infection. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Campylobacter jejuni--an emerging foodborne pathogen.

PubMed

Altekruse, S F; Stern, N J; Fields, P I; Swerdlow, D L

1999-01-01

Campylobacter jejuni is the most commonly reported bacterial cause of foodborne infection in the United States. Adding to the human and economic costs are chronic sequelae associated with C. jejuni infection--Guillian-Barré syndrome and reactive arthritis. In addition, an increasing proportion of human infections caused by C. jejuni are resistant to antimicrobial therapy. Mishandling of raw poultry and consumption of undercooked poultry are the major risk factors for human campylobacteriosis. Efforts to prevent human illness are needed throughout each link in the food chain.

Screening for duplications, deletions and a common intronic mutation detects 35% of second mutations in patients with USH2A monoallelic mutations on Sanger sequencing.

PubMed

Steele-Stallard, Heather B; Le Quesne Stabej, Polona; Lenassi, Eva; Luxon, Linda M; Claustres, Mireille; Roux, Anne-Francoise; Webster, Andrew R; Bitner-Glindzicz, Maria

2013-08-08

Usher Syndrome is the leading cause of inherited deaf-blindness. It is divided into three subtypes, of which the most common is Usher type 2, and the USH2A gene accounts for 75-80% of cases. Despite recent sequencing strategies, in our cohort a significant proportion of individuals with Usher type 2 have just one heterozygous disease-causing mutation in USH2A, or no convincing disease-causing mutations across nine Usher genes. The purpose of this study was to improve the molecular diagnosis in these families by screening USH2A for duplications, heterozygous deletions and a common pathogenic deep intronic variant USH2A: c.7595-2144A>G. Forty-nine Usher type 2 or atypical Usher families who had missing mutations (mono-allelic USH2A or no mutations following Sanger sequencing of nine Usher genes) were screened for duplications/deletions using the USH2A SALSA MLPA reagent kit (MRC-Holland). Identification of USH2A: c.7595-2144A>G was achieved by Sanger sequencing. Mutations were confirmed by a combination of reverse transcription PCR using RNA extracted from nasal epithelial cells or fibroblasts, and by array comparative genomic hybridisation with sequencing across the genomic breakpoints. Eight mutations were identified in 23 Usher type 2 families (35%) with one previously identified heterozygous disease-causing mutation in USH2A. These consisted of five heterozygous deletions, one duplication, and two heterozygous instances of the pathogenic variant USH2A: c.7595-2144A>G. No variants were found in the 15 Usher type 2 families with no previously identified disease-causing mutations. In 11 atypical families, none of whom had any previously identified convincing disease-causing mutations, the mutation USH2A: c.7595-2144A>G was identified in a heterozygous state in one family. All five deletions and the heterozygous duplication we report here are novel. This is the first time that a duplication in USH2A has been reported as a cause of Usher syndrome. We found that 8 of 23 (35%) of 'missing' mutations in Usher type 2 probands with only a single heterozygous USH2A mutation detected with Sanger sequencing could be attributed to deletions, duplications or a pathogenic deep intronic variant. Future mutation detection strategies and genetic counselling will need to take into account the prevalence of these types of mutations in order to provide a more comprehensive diagnostic service.

Detecting the emergence of novel, zoonotic viruses pathogenic to humans.

PubMed

Rosenberg, Ronald

2015-03-01

RNA viruses, with their high potential for mutation and epidemic spread, are the most common class of pathogens found as new causes of human illness. Despite great advances made in diagnostic technology since the 1950s, the annual rate at which novel virulent viruses have been found has remained at 2-3. Most emerging viruses are zoonoses; they have jumped from mammal or bird hosts to humans. An analysis of virus discovery indicates that the small number of novel viruses discovered annually is an artifact of inadequate surveillance in tropical and subtropical countries, where even established endemic pathogens are often misdiagnosed. Many of the emerging viruses of the future are already infecting humans but remain to be uncovered by a strategy of disease surveillance in selected populations.

Novel organisms: comparing invasive species, GMOs, and emerging pathogens.

PubMed

Jeschke, Jonathan M; Keesing, Felicia; Ostfeld, Richard S

2013-09-01

Invasive species, range-expanding species, genetically modified organisms (GMOs), synthetic organisms, and emerging pathogens increasingly affect the human environment. We propose a framework that allows comparison of consecutive stages that such novel organisms go through. The framework provides a common terminology for novel organisms, facilitating knowledge exchange among researchers, managers, and policy makers that work on, or have to make effective decisions about, novel organisms. The framework also indicates that knowledge about the causes and consequences of stage transitions for the better studied novel organisms, such as invasive species, can be transferred to more poorly studied ones, such as GMOs and emerging pathogens. Finally, the framework advances understanding of how climate change can affect the establishment, spread, and impacts of novel organisms, and how biodiversity affects, and is affected by, novel organisms.

Pathogenic variability of individuals and populations of cucurbit powdery mildew–great confusion and great mystery, or why we still need the classical phytopathology.

USDA-ARS?s Scientific Manuscript database

Golovinomyces cichoracearum and Podosphaera xanthii (family Erysiphales) are considered the most important species causing cucurbit powdery mildew (CPM), a serious disease of field and greenhouse cucurbits. Podosphaera xanthii (Px) is common in subtropical and tropical areas and in greenhouses in te...

De novo genome assembly of Geosmithia morbida, the causal agent of thousand cankers disease

Treesearch

Taruna A. Schuelke; Anthony Westbrook; Kirk Broders; Keith Woeste; Matthew D. MacManes

2016-01-01

Geosmithia morbida is a filamentous ascomycete that causes thousand cankers disease in the eastern black walnut tree. This pathogen is commonly found in the western U.S.; however, recently the disease was also detected in several eastern states where the black walnut lumber industry is concentrated. G. morbida is one of two...

Convergent evolution in peptidoglycan cut sites of phage endolysins protecting mice from methicillin-resistant Staphylococcus aureus septicemia

USDA-ARS?s Scientific Manuscript database

Staphylococcus S. aureus is a Gram-positive pathogen relevant for both human and animal health. It is one of the most common causes of nosocomial infections and associated with a wide range of life-threatening human diseases. As the major causative agent of bovine mastitis, it also has significant ...

First report of Fusarium graminearum, F. asiaticum and F. cortaderiae as head blight pathogens of annual ryegrass in Brazil

USDA-ARS?s Scientific Manuscript database

Members of the Fusarium graminearum species complex (FGSC) cause Fusarium head blight (FHB) of small grains and several grasses, including annual ryegrass (Lolium multiflorum Lam.), an important forage crop, but also a common weed in wheat, rice and maize agroecosystem in southern Brazil. Although i...

Evaluation of four commercial natural products for repellency and toxicity against the lone star tick, Amblyomma americanum (Acari: Ixodidae)

USDA-ARS?s Scientific Manuscript database

Lone star ticks are aggressive ectoparasites of domestic and wild animals, as well as humans. These ticks can transmit many pathogens that cause disease including Erhlichia and tularemia. Common compounds used for personal protection and area sprays are N-diethyl-3-methyl benzamide (DEET) and permet...

Mycoplasma pneumoniae Epidemiology in England and Wales: A National Perspective.

PubMed

Brown, Rebecca J; Nguipdop-Djomo, Patrick; Zhao, Hongxin; Stanford, Elaine; Spiller, O Brad; Chalker, Victoria J

2016-01-01

Investigations of patients with suspected Mycoplasma pneumoniae infection have been undertaken in England since the early 1970s. M. pneumoniae is a respiratory pathogen that is a common cause of pneumonia and may cause serious sequelae such as encephalitis and has been documented in children with persistent cough. The pathogen is found in all age groups, with higher prevalence in children aged 5-14 years. In England, recurrent epidemic periods have occurred at ~4-yearly intervals. In addition, low-level sporadic infection occurs with seasonal peaks from December to February. Voluntarily reports from regional laboratories and hospitals in England from 1975 to 2015 were collated by Public Health England for epidemiological analysis. Further data pertaining cases of note and specimens submitted to Public Health England from 2005 to 2015 for confirmation, molecular typing is included.

Economic comparison of common treatment protocols and J5 vaccination for clinical mastitis in dairy herds using optimized culling decisions.

PubMed

Kessels, J A; Cha, E; Johnson, S K; Welcome, F L; Kristensen, A R; Gröhn, Y T

2016-05-01

This study used an existing dynamic optimization model to compare costs of common treatment protocols and J5 vaccination for clinical mastitis in US dairy herds. Clinical mastitis is an infection of the mammary gland causing major economic losses in dairy herds due to reduced milk production, reduced conception, and increased risk of mortality and culling for infected cows. Treatment protocols were developed to reflect common practices in dairy herds. These included targeted therapy following pathogen identification, and therapy without pathogen identification using a broad-spectrum antimicrobial or treating with the cheapest treatment option. The cost-benefit of J5 vaccination was also estimated. Effects of treatment were accounted for as changes in treatment costs, milk loss due to mastitis, milk discarded due to treatment, and mortality. Following ineffective treatments, secondary decisions included extending the current treatment, alternative treatment, discontinuing treatment, and pathogen identification followed by recommended treatment. Average net returns for treatment protocols and vaccination were generated using an existing dynamic programming model. This model incorporates cow and pathogen characteristics to optimize management decisions to treat, inseminate, or cull cows. Of the treatment protocols where 100% of cows received recommended treatment, pathogen-specific identification followed by recommended therapy yielded the highest average net returns per cow per year. Out of all treatment scenarios, the highest net returns were achieved with selecting the cheapest treatment option and discontinuing treatment, or alternate treatment with a similar spectrum therapy; however, this may not account for the full consequences of giving nonrecommended therapies to cows with clinical mastitis. Vaccination increased average net returns in all scenarios. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Detection of Viral and Bacterial Pathogens in Hospitalized Children With Acute Respiratory Illnesses, Chongqing, 2009–2013

PubMed Central

Wei, Lan; Liu, Wei; Zhang, Xiao-Ai; Liu, En-Mei; Wo, Yin; Cowling, Benjamin J.; Cao, Wu-Chun

2015-01-01

Abstract Acute respiratory infections (ARIs) cause large disease burden each year. The codetection of viral and bacterial pathogens is quite common; however, the significance for clinical severity remains controversial. We aimed to identify viruses and bacteria in hospitalized children with ARI and the impact of mixed detections. Hospitalized children with ARI aged ≤16 were recruited from 2009 to 2013 at the Children's Hospital of Chongqing Medical University, Chongqing, China. Nasopharyngeal aspirates (NPAs) were collected for detection of common respiratory viruses by reverse transcription polymerase chain reaction (RT-PCR) or PCR. Bacteria were isolated from NPAs by routine culture methods. Detection and codetection frequencies and clinical features and severity were compared. Of the 3181 hospitalized children, 2375 (74.7%) were detected with ≥1 virus and 707 (22.2%) with ≥1 bacteria, 901 (28.3%) with ≥2 viruses, 57 (1.8%) with ≥2 bacteria, and 542 (17.0%) with both virus and bacteria. The most frequently detected were Streptococcus pneumoniae, respiratory syncytial virus, parainfluenza virus, and influenza virus. Clinical characteristics were similar among different pathogen infections for older group (≥6 years old), with some significant difference for the younger. Cases with any codetection were more likely to present with fever; those with ≥2 virus detections had higher prevalence of cough; cases with virus and bacteria codetection were more likely to have cough and sputum. No significant difference in the risk of pneumonia, severe pneumonia, and intensive care unit admission were found for any codetection than monodetection. There was a high codetection rate of common respiratory pathogens among hospitalized pediatric ARI cases, with fever as a significant predictor. Cases with codetection showed no significant difference in severity than those with single pathogens. PMID:25906103

Aseptic and Bacterial Meningitis: Evaluation, Treatment, and Prevention.

PubMed

Mount, Hillary R; Boyle, Sean D

2017-09-01

The etiologies of meningitis range in severity from benign and self-limited to life-threatening with potentially severe morbidity. Bacterial meningitis is a medical emergency that requires prompt recognition and treatment. Mortality remains high despite the introduction of vaccinations for common pathogens that have reduced the incidence of meningitis worldwide. Aseptic meningitis is the most common form of meningitis with an annual incidence of 7.6 per 100,000 adults. Most cases of aseptic meningitis are viral and require supportive care. Viral meningitis is generally self-limited with a good prognosis. Examination maneuvers such as Kernig sign or Brudzinski sign may not be useful to differentiate bacterial from aseptic meningitis because of variable sensitivity and specificity. Because clinical findings are also unreliable, the diagnosis relies on the examination of cerebrospinal fluid obtained from lumbar puncture. Delayed initiation of antibiotics can worsen mortality. Treatment should be started promptly in cases where transfer, imaging, or lumbar puncture may slow a definitive diagnosis. Empiric antibiotics should be directed toward the most likely pathogens and should be adjusted by patient age and risk factors. Dexamethasone should be administered to children and adults with suspected bacterial meningitis before or at the time of initiation of antibiotics. Vaccination against the most common pathogens that cause bacterial meningitis is recommended. Chemoprophylaxis of close contacts is helpful in preventing additional infections.

Genetic and pathogenic difference between Streptococcus agalactiae serotype Ia fish and human isolates.

PubMed

Chu, Chishih; Huang, Pei-Yu; Chen, Hung-Ming; Wang, Ying-Hsiang; Tsai, I-An; Lu, Chih-Cheng; Chen, Che-Chun

2016-08-02

Streptococcus agalactiae (GBS) is a common pathogen to infect newborn, woman, the elderly, and immuno-compromised human and fish. 37 fish isolates and 554 human isolates of the GBS in 2007-2012 were investigated in serotypes, antibiotic susceptibility, genetic difference and pathogenicity to tilapia. PCR serotyping determined serotype Ia for all fish GBS isolates and only in 3.2 % (3-4.2 %) human isolates. For fish isolates, all consisted a plasmid less than 6 kb and belonged to ST7 type, which includes mainly pulsotypes I and Ia, with a difference in a deletion at the largest DNA fragment. These fish isolates were susceptible to all antimicrobials tested in 2007 and increased in non-susceptibility to penicillin, and resistance to clindamycin and ceftriaxone in 2011. Differing in pulsotype and lacking plasmid from fish isolates, human serotype Ia isolates were separated into eight pulsotypes II-IX. Main clone ST23 included pulsotypes II and IIa (50 %) and ST483 consisted of pulsotype III. Human serotype Ia isolates were all susceptible to ceftriaxone and penicillin and few were resistant to erythromycin, azithromycin, clindamycin, levofloxacin and moxifloxacine with the resistant rate of 20 % or less. Using tilapia to analyze the pathogenesis, fish isolates could cause more severe symptoms, including hemorrhage of the pectoral fin, hemorrhage of the gill, and viscous black and common scites, and mortality (>95 % for pulsotype I) than the human isolates (<30 %); however, the fish pulostype Ia isolate 912 with deletion caused less symptoms and the lowest mortality (<50 %) than pulsotype I isolates. Genetic, pathogenic, and antimicrobial differences demonstrate diverse origin of human and fish serotype Ia isolates. The pulsotype Ia of fish serotype Ia isolates may be used as vaccine strains to prevent the GBS infection in fish.

Nebulization of Antiinfective Agents in Invasively Mechanically Ventilated Adults: A Systematic Review and Meta-analysis.

PubMed

Solé-Lleonart, Candela; Rouby, Jean-Jacques; Blot, Stijn; Poulakou, Garyfallia; Chastre, Jean; Palmer, Lucy B; Bassetti, Matteo; Luyt, Charles-Edouard; Pereira, Jose M; Riera, Jordi; Felton, Tim; Dhanani, Jayesh; Welte, Tobias; Garcia-Alamino, Jose M; Roberts, Jason A; Rello, Jordi

2017-05-01

Nebulization of antiinfective agents is a common but unstandardized practice in critically ill patients. A systematic review of 1,435 studies was performed in adults receiving invasive mechanical ventilation. Two different administration strategies (adjunctive and substitute) were considered clinically relevant. Inclusion was restricted to studies using jet, ultrasonic, and vibrating-mesh nebulizers. Studies involving children, colonized-but-not-infected adults, and cystic fibrosis patients were excluded. Five of the 11 studies included had a small sample size (fewer than 50 patients), and only 6 were randomized. Diversity of case-mix, dosage, and devices are sources of bias. Only a few patients had severe hypoxemia. Aminoglycosides and colistin were the most common antibiotics, being safe regarding nephrotoxicity and neurotoxicity, but increased respiratory complications in 9% (95% CI, 0.01 to 0.18; I = 52%), particularly when administered to hypoxemic patients. For tracheobronchitis, a significant decrease in emergence of resistance was evidenced (risk ratio, 0.18; 95% CI, 0.05 to 0.64; I = 0%). Similar findings were observed in pneumonia by susceptible pathogens, without improvement in mortality or ventilation duration. In pneumonia caused by resistant pathogens, higher clinical resolution (odds ratio, 1.96; 95% CI, 1.30 to 2.96; I = 0%) was evidenced. These findings were not consistently evidenced in the assessment of efficacy against pneumonia caused by susceptible pathogens. Performance of randomized trials evaluating the impact of nebulized antibiotics with more homogeneous populations, standardized drug delivery, predetermined clinical efficacy, and safety outcomes is urgently required. Infections by resistant pathogens might potentially have higher benefit from nebulized antiinfective agents. Nebulization, without concomitant systemic administration of the drug, may reduce nephrotoxicity but may also be associated with higher risk of respiratory complications.

Cow-specific risk factors for clinical mastitis in Brazilian dairy cattle.

PubMed

Oliveira, C S F; Hogeveen, H; Botelho, A M; Maia, P V; Coelho, S G; Haddad, J P A

2015-10-01

Information related to mastitis risk factors is useful for the design and implementation of clinical mastitis (CM) control programs. The first objective of our study was to model the risk of CM under Brazilian conditions, using cow-specific risk factors. Our second objective was to explore which risk factors were associated with the occurrence of the most common pathogens involved in Brazilian CM infections. The analyses were based on 65 months of data from 9,789 dairy cows and 12,464 CM cases. Cow-specific risk factors that could easily be measured in standard Brazilian dairy farms were used in the statistical analyses, which included logistic regression and multinomial logistic regression. The first month of lactation, high somatic cell count, rainy season and history of clinical mastitis cases were factors associated with CM for both primiparous and multiparous cows. In addition, parity and breed were also associated risk factors for multiparous cows. Of all CM cases, 54% showed positive bacteriological culturing results from which 57% were classified as environmental pathogens, with a large percentage of coliforms (35%). Coagulase-negative Staphylococcus (16%), Streptococcus uberis (9%), Streptococcus agalactiae (7%) and other Streptococci (9%) were also common pathogens. Among the pathogens analyzed, the association of cow-specific risk factors, such as Zebu breed (OR=5.84, 95%CI 3.77-10.77) and accumulated history of SCC (1.76, 95%CI 1.37-2.27), was different for CM caused by Coagulase-negative Staphylococcus and S. agalactiae in comparison to CM caused by coliforms. Our results suggest that CM control programs in Brazil should specially consider the recent history of clinical mastitis cases and the beginning of the lactations, mainly during the rainy season as important risk factor for mastitis. Copyright © 2015 Elsevier B.V. All rights reserved.

Prevalence and Seasonal Distribution of Respiratory Viruses During the 2014 - 2015 Season in Istanbul

PubMed Central

Goktas, Safak; Sirin, Mumtaz Cem

2016-01-01

Background Acute respiratory tract infection (ARTI) is one of the most common infections worldwide, causing significant morbidity and mortality. Objectives This study was conducted to determine the prevalence and seasonal distribution of respiratory viruses in our region, in children and adults with a pre-diagnosis of ARTI. Methods A total of 845 nasopharyngeal swab specimens were analyzed with the RespiFinder Smart 22 kit (PathoFinder BV, Netherlands) and the Rotor-Gene 6000 real-time PCR system. Results At least one pathogen was detected in 612 (72.4%) of the specimens. Overall, 902 pathogens were detected; 821 (91%) were viruses and 81 (9%) were bacteria. The most commonly detected pathogens were influenza A virus (IFV-A) (n = 219), influenza B virus (IFV-B) (n=157), rhinovirus/enterovirus (n = 107), human bocavirus (HBoV) (n = 91), respiratory syncytial virus (RSV) A/B (n = 64), adenovirus (n = 56), human coronaviruses (n = 51), Mycoplasma pneumoniae (n = 49), parainfluenza viruses (n = 40), human metapneumovirus (n = 36), Bordetella pertussis (n = 15), Legionella pneumophila (n = 11), and Chlamydophila pneumoniae (n = 6), respectively. Among the 215 (25.4%) co-infected cases, IFV-A/HBoV and IFV-A/IFV-B were the most common co-infections. IFV-A was the most prevalent agent in all age groups except for children under 5 years of age, in whom RSV A/B was the most common pathogen. Approximately two thirds of the respiratory viruses were detected in early spring and winter, with peaks in January, March, and April. Conclusions With regard to the prevalence and seasonal distribution of respiratory viruses, our epidemiological data for the 2014 - 2015 season in Istanbul showed a predominance of IFV-A infections with a peak activity in early spring. Enhanced surveillance and early detection of respiratory viral pathogens can be useful in the diagnosis, treatment, and prevention of ARTIs, and for guiding the development of appropriate public health strategies. PMID:27800148

The consequences of human actions on risks for infectious diseases: a review

PubMed Central

Lindahl, Johanna F.; Grace, Delia

2015-01-01

The human population is growing, requiring more space for food production, and needing more animals to feed it. Emerging infectious diseases are increasing, causing losses in both human and animal lives, as well as large costs to society. Many factors are contributing to disease emergence, including climate change, globalization and urbanization, and most of these factors are to some extent caused by humans. Pathogens may be more or less prone to emergence in themselves, and rapidly mutating viruses are more common among the emerging pathogens. The climate-sensitive vector-borne diseases are likely to be emerging due to climate changes and environmental changes, such as increased irrigation. This review lists the factors within pathogens that make them prone to emergence, and the modes of transmission that are affected. The anthropogenic changes contributing to disease emergence are described, as well as how they directly and indirectly cause either increased numbers of susceptible or exposed individuals, or cause increased infectivity. Many actions may have multiple direct or indirect effects, and it may be difficult to assess what the consequences may be. In addition, most anthropogenic drivers are related to desired activities, such as logging, irrigation, trade, and travelling, which the society is requiring. It is important to research more about the indirect and direct effects of the different actions to understand both the benefits and the risks. PMID:26615822

A Novel Missense Mutation p.Gly162Glu of the Gene MYL2 Involved in Hypertrophic Cardiomyopathy: A Pedigree Analysis of a Proband.

PubMed

Renaudin, Pauline; Janin, Alexandre; Millat, Gilles; Chevalier, Philippe

2018-04-01

Hypertrophic cardiomyopathy (HCM), a common and clinically heterogeneous disease characterized by unexplained ventricular myocardial hypertrophy, is mostly caused by mutations in sarcomeric genes. Identifying the genetic cause is important for management, therapy, and genetic counseling. A molecular diagnosis was performed on a 51-year-old woman diagnosed with HCM using a next-generation sequencing workflow based on a panel designed for sequencing the most prevalent cardiomyopathy-causing genes. Segregation analysis was performed on the woman's family. A novel myosin regulatory light chain (MYL2) missense variant, NM_000432.3:c485G>A, p.Gly162Glu, was identified and firstly considered as a putative pathogenic mutation. Among the 27 family members tested, 16 were carriers for the MYL2-p.Gly162Glu mutation, of whom 12 with the phenotype were positive. None of the 11 family members without mutation had cardiomyopathy. Genetic analysis combined with a segregation study allowed us to classify this novel MYL2 variation, p.Gly162Glu, as a novel pathogenic mutation leading to a familial form of HCM. Due to absence of fast in vitro approaches to evaluate the functional impact of missense variants on HCM-causing genes, segregation studies remain, when possible, the easiest approach to evaluate the putative pathogenicity of novel gene variants, more particularly missense ones.

Surgical treatment for pulmonary aspergilloma in seventeenth years old female: case report

NASA Astrophysics Data System (ADS)

Yanni, G. N.; Lubis, M.; Yoel, C.

2018-03-01

Aspergillosis is defined as a mycosis group caused by various pathogenic fungi of the Aspergillus genus. Aspergillus has more than 900 species that cause infection in human. The most common Aspergillus species that cause infection is Aspergillus fumigatus, about 90%. Other species, Aspergillus flavus, about 10% cause invasive disease. Have been reported a young girl 17-year-8-month-old woman was admitted to emergency with complaints of coughing up blood. The patient has diagnosed an aspergilloma and treated with thoracotomy bi-lobectomy right lower lung based on thorax scan. The patient took Fluconazole and surgical bilobectomyfor treated the aspergilloma and got improvement.

Identification and antimicrobial resistance of pathogens in neonatal septicemia in China-A meta-analysis.

PubMed

Li, Jing-Yang; Chen, Shang-Qin; Yan, Yan-Yan; Hu, Ying-Ying; Wei, Jia; Wu, Qiu-Ping; Lin, Zhen-Lang; Lin, Jing

2018-06-01

The purpose of this study was to analyze the distribution and antimicrobial resistance of common bacterial pathogens causing neonatal septicemia based on a systematic review of published studies in China. Articles on neonatal sepsis published in the Chinese literature from 2009 to 2014 were identified according to the inclusion and exclusion criteria. Data were extracted and analyzed using Comprehensive Meta-Analysis software. A total of 71 studies were included, in which a total of 8080 bacterial species were isolated from culture-positive blood samples. The pooled distribution rates of common bacterial pathogens were as follows: Staphylococcus 67.1% (95% confidence interval (CI) 63.3-70.6%), Enterococcus 4.1% (95% CI 3.5-4.8%), Streptococcus 2.3% (95% CI 1.6-3.2%), Escherichia coli 7.4% (95% CI 6.4-8.7%), Klebsiella 6.5% (95% CI 5.2-8.2%), Enterobacterium 2.3% (95% CI 1.9-2.8%), Acinetobacter 1.6% (95% CI 1.3-2.0%), Pseudomonas 1.7% (95% CI 1.3-2.2%). Among the Staphylococcus aureus strains isolated, more than 60% were methicillin-resistant (MRSA). In addition, over 50% of the Gram-negative isolates, including Escherichia and Klebsiella, were resistant to the commonly used third-generation cephalosporins. Most of the Gram-positive and Gram-negative bacteria isolated were sensitive to aminoglycosides, especially amikacin. It is concluded that Staphylococcus, especially coagulase-negative Staphylococcus, continues to be the principal organism responsible for neonatal septicemia in China; Enterobacteriaceae are common among the Gram-negative isolates. Significant numbers of MRSA and multidrug-resistant Gram-negative bacteria are being isolated as pathogens responsible for neonatal septicemia in China. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Using high-resolution variant frequencies to empower clinical genome interpretation.

PubMed

Whiffin, Nicola; Minikel, Eric; Walsh, Roddy; O'Donnell-Luria, Anne H; Karczewski, Konrad; Ing, Alexander Y; Barton, Paul J R; Funke, Birgit; Cook, Stuart A; MacArthur, Daniel; Ware, James S

2017-10-01

PurposeWhole-exome and whole-genome sequencing have transformed the discovery of genetic variants that cause human Mendelian disease, but discriminating pathogenic from benign variants remains a daunting challenge. Rarity is recognized as a necessary, although not sufficient, criterion for pathogenicity, but frequency cutoffs used in Mendelian analysis are often arbitrary and overly lenient. Recent very large reference datasets, such as the Exome Aggregation Consortium (ExAC), provide an unprecedented opportunity to obtain robust frequency estimates even for very rare variants.MethodsWe present a statistical framework for the frequency-based filtering of candidate disease-causing variants, accounting for disease prevalence, genetic and allelic heterogeneity, inheritance mode, penetrance, and sampling variance in reference datasets.ResultsUsing the example of cardiomyopathy, we show that our approach reduces by two-thirds the number of candidate variants under consideration in the average exome, without removing true pathogenic variants (false-positive rate<0.001).ConclusionWe outline a statistically robust framework for assessing whether a variant is "too common" to be causative for a Mendelian disorder of interest. We present precomputed allele frequency cutoffs for all variants in the ExAC dataset.

Rice Sheath Rot: An Emerging Ubiquitous Destructive Disease Complex

PubMed Central

Bigirimana, Vincent de P.; Hua, Gia K. H.; Nyamangyoku, Obedi I.; Höfte, Monica

2015-01-01

Around one century ago, a rice disease characterized mainly by rotting of sheaths was reported in Taiwan. The causal agent was identified as Acrocylindrium oryzae, later known as Sarocladium oryzae. Since then it has become clear that various other organisms can cause similar disease symptoms, including Fusarium sp. and fluorescent pseudomonads. These organisms have in common that they produce a range of phytotoxins that induce necrosis in plants. The same agents also cause grain discoloration, chaffiness, and sterility and are all seed-transmitted. Rice sheath rot disease symptoms are found in all rice-growing areas of the world. The disease is now getting momentum and is considered as an important emerging rice production threat. The disease can lead to variable yield losses, which can be as high as 85%. This review aims at improving our understanding of the disease etiology of rice sheath rot and mainly deals with the three most reported rice sheath rot pathogens: S. oryzae, the Fusarium fujikuroi complex, and Pseudomonas fuscovaginae. Causal agents, pathogenicity determinants, interactions among the various pathogens, epidemiology, geographical distribution, and control options will be discussed. PMID:26697031

The potential of pathogens as biological control of parthenium weed (Parthenium hysterophorus L.) in Ethiopia.

PubMed

Taye, T; Gossmann, M; Einhorn, G; Büttner, C; Metz, R; Abate, D

2002-01-01

P. hsyterophorus is an exotic invasive annual weed now causing severe infestation in Ethiopia. Studies on diagnosis, incidence and distribution of pathogens associated with parthenium weed in Ethiopia were carried out from 1998-2002. Several fungal isolates were obtained from seed and other parts of parthenium plants. Among them were putative pathogenic fungal species of the genus Helminthosporium, Phoma, Curvularia, Chaetomium, Alternaria, and Fusarium. However, pathogenecity test of the isolates obtained showed no or non-specific symptoms. It was concluded that these pathogens could be opportunistic with insignificant potential for biological control of parthenium. Two most important diseases associated with parthenium were a rust disease, caused by Puccinia abrupta var. partheniicola, and a phyllody disease, caused by a phytoplasma of fababean phyllody (PBP) phytoplasma group. The rust was commonly found in cool mid altitude (1500-2500 m) areas while phyllody was observed in low to mid altitude regions (900-2500 m) of Ethiopia, with a disease incidence up to 100% and 75%, respectively, in some locations. Study of the individual effects of the rust and phyllody diseases under field conditions showed a reduction on weed morphological parameters (plant height, leaf area, and dry matter yield). Parthenium seed production was reduced by 42% and 85% due to rust and phyllody, respectively. Phyllody and rust diseases of parthenium showed significant potential for classical biological control of parthenium after further confirmation of insect vectors that transmit phyllody and host range of phyllody disease to the related economic plants in Ethiopia.

MICROBIAL PROFILE AND ANTIBIOTIC SUSCEPTIBILITY PATTERNS OF PATHOGENS CAUSING VENTILATOR- ASSOCIATED PNEUMONIA AT INTENSIVE CARE UNIT, SESTRE MILOSRDNICE UNIVERSITY HOSPITAL CENTER, ZAGREB, CROATIA.

PubMed

Turković, Tihana Magdić; Grginić, Ana Gverić; Cucujić, Branka Đuras; Gašpar, Božena; Širanović, Mladen; Perić, Mladen

2015-06-01

Ventilator-associated pneumonia (VAP) is very common in many intensive care Units, but there are still many uncertainties about VAP, especially about the choice of initial empiric antibiotics. The incidence of specific pathogens with different susceptibility patterns causing VAP varies from hospital to hospital. This is the reason why empiric initial antibiotic treatment for VAP should be based not only on general guidelines (that recommend therapy according to the presence of risk factors for multidrug-resistant bacteria), but also on up-to-date information on local epidemiology. The aim of this study was to determine the microbial profile of pathogens causing VAP and their antibiotic susceptibility patterns. The study was conducted in the 15-bed surgical and neurosurgical Intensive Care Unit, Department of Anesthesiology and Intensive Care, Sestre milosrdnice University Hospital Center, Zagreb, Croatia. Retrospective data were collected from September 2009 to March 2013. All patients that developed VAP during the study period were eligible for the study. According to study results, the incidence of VAP was 29.4%. The most commonly isolated bacterium was Staphylococcus aureus (21.1%), followed by Pseudomonas aeruginosa (19.0%) and Acinetobacter species (13.6%). All Staphylococcus aureus isolates were susceptible to vancomycin and linezolid. Pseudomonas aeruginosa showed 100% susceptibility to cefepime and very high susceptibility to pip'eracillin-tazobactam (96%), ceftazidime (93%) and ciprofloxacin (89%). Ampicillin-sulbactam was highly effective for Acinetobacter species, showing resistance in only 8% of isolates. In conclusion, according to study data, appropriate empiric antibiotic therapy for patients with VAP without risk factors for multidrug-resistant bacteria is ceftriaxone and for patients with risk factors for multidrug-resistant bacteria ampicillin-sulbactam plus cefepime plus vancomycin or linezolid.

Analysis of a Food-Borne Fungal Pathogen Outbreak: Virulence and Genome of a Mucor circinelloides Isolate from Yogurt

PubMed Central

Billmyre, R. Blake; Li, Alicia; Carson, Sandra; Sykes, Sean M.; Huh, Eun Young; Mieczkowski, Piotr; Ko, Dennis C.; Cuomo, Christina A.

2014-01-01

ABSTRACT Food-borne pathogens are ongoing problems, and new pathogens are emerging. The impact of fungi, however, is largely underestimated. Recently, commercial yogurts contaminated with Mucor circinelloides were sold, and >200 consumers became ill with nausea, vomiting, and diarrhea. Mucoralean fungi cause the fatal fungal infection mucormycosis, whose incidence has been continuously increasing. In this study, we isolated an M. circinelloides strain from a yogurt container, and multilocus sequence typing identified the strain as Mucor circinelloides f. circinelloides. M. circinelloides f. circinelloides is the most virulent M. circinelloides subspecies and is commonly associated with human infections, whereas M. circinelloides f. lusitanicus and M. circinelloides f. griseocyanus are less common causes of infection. Whole-genome analysis of the yogurt isolate confirmed it as being close to the M. circinelloides f. circinelloides subgroup, with a higher percentage of divergence with the M. circinelloides f. lusitanicus subgroup. In mating assays, the yogurt isolate formed sexual zygospores with the (−) M. circinelloides f. circinelloides tester strain, which is congruent with its sex locus encoding SexP, the (+) mating type sex determinant. The yogurt isolate was virulent in murine and wax moth larva host systems. In a murine gastromucormycosis model, Mucor was recovered from fecal samples of infected mice for up to 10 days, indicating that Mucor can survive transit through the GI tract. In interactions with human immune cells, M. circinelloides f. lusitanicus induced proinflammatory cytokines but M. circinelloides f. circinelloides did not, which may explain the different levels of virulence in mammalian hosts. This study demonstrates that M. circinelloides can spoil food products and cause gastrointestinal illness in consumers and may pose a particular risk to immunocompromised patients. PMID:25006230

The expanding spectrum of human infections caused by Kocuria species: a case report and literature review

PubMed Central

Purty, Shashikala; Saranathan, Rajagopalan; Prashanth, K; Narayanan, K; Asir, Johny; Sheela Devi, Chandrakesan; Kumar Amarnath, Satish

2013-01-01

Although not previously known to cause human infections, Kocuria species have now emerged as human pathogens, mostly in compromised hosts with severe underlying disease. Recently, there has been an increasing incidence of different types of Kocuria infections reported, most likely due to the adoption of better identification methods. Here, we report a case of peritonitis caused by Kocuria rosea in a diabetic nephropathy patient who was on continuous ambulatory peritoneal dialysis. Sepsis and peritonitis caused by K. rosea in our case yielded two identical Kocuria isolates from the peritoneal dialysate fluid within a period of three days. The infection was subsequently resolved by antibiotic treatment and catheter removal. In addition to reporting this case, we herein review the literature concerning the emergence of Kocuria as a significant human pathogen. The majority of cases were device-related, acquired in the hospital or endogenous, and different Kocuria species appear to share a common etiology of peritonitis. The overall disease burden associated with Kocuria appears to be high, and the treatment guidelines for diseases associated with Kocuria have not yet been clearly defined. PMID:26038440

Workplace cluster of Bell’s palsy in Lima, Peru

PubMed Central

2014-01-01

Background We report on a workplace cluster of Bell’s palsy that occurred within a four-month period in 2011 among employees of a three-story office building in Lima, Peru and our investigation to determine the etiology and associated risk factors. Findings An outbreak investigation was conducted to identify possible common infectious or environmental exposures and included patient interviews, reviews of medical records, an epidemiologic survey, serological analysis for IgM and IgG antibodies to putative Bell’s palsy-inducing pathogens, and an environmental exposure assessment of the office building. Three cases of Bell’s palsy were reported among 65 at-risk employees, attack rate 4.6%. Although two patients had underlying risk factors, there was no clear association or common identifiable risk factor among all cases. Serologic analysis showed no evidence of recent infections, and air and water sample measures of all known chemical or neurotoxins were below maximum allowable concentrations for exposure. Conclusions An infection spread among workplace employees could not be excluded as a potential cause of this cluster; however, it was unlikely a pathogen commonly associated with individual cases of Bell’s palsy. Although a specific etiology was not identified among all cases, we believe this methodology will aid future outbreak investigations of Bell’s palsy and a better understanding of its etiology. While environmental assessments may be useful in their ability to ascertain the cause of clusters of Bell’s palsy, future investigations should prioritize focus on common infectious etiology. PMID:24885256

Identification of genetic and environmental factors stimulating excision from Streptomyces scabiei chromosome of the toxicogenic region responsible for pathogenicity.

PubMed

Chapleau, Mélanie; Guertin, Julien F; Farrokhi, Ali; Lerat, Sylvain; Burrus, Vincent; Beaulieu, Carole

2016-05-01

The genes conferring pathogenicity in Streptomyces turgidiscabies, a pathogen causing common scab of potato, are grouped together on a pathogenicity island (PAI), which has been found to be mobile and appears to transfer and disseminate like an integrative and conjugative element (ICE). However, in Streptomyces scabiei, another common scab-inducing species, the pathogenicity genes are clustered in two regions: the toxicogenic region (TR) and the colonization region. The S. scabiei 87.22 genome was analysed to investigate the potential mobility of the TR. Attachment sites (att), short homologous sequences that delineate ICEs, were identified at both extremities of the TR. An internal att site was also found, suggesting that the TR has a composite structure (TR1 and TR2). Thaxtomin biosynthetic genes, essential for pathogenicity, were found in TR1, whereas candidate genes with known functions in recombination, replication and conjugal transfer were found in TR2. Excision of the TR1 or TR2 subregions alone, or of the entire TR region, was observed, although the excision frequency of TR was low. However, the excision frequency was considerably increased in the presence of either mitomycin C or Streptomyces coelicolor cells. A composite TR structure was not observed in all S. scabiei and Streptomyces acidiscabies strains tested. Of the ten strains analysed, seven lacked TR2 and no TR excision event could be detected in these strains, thus suggesting the implication of TR2 in the mobilization of S. scabiei TR. © 2015 BSPP AND JOHN WILEY & SONS LTD.

The clinical and microbiological characteristics of infections in burn patients from the Formosa Fun Coast Dust Explosion.

PubMed

Lin, Tzu-Chao; Wu, Rui-Xin; Chiu, Chih-Chien; Yang, Ya-Sung; Lee, Yi; Lin, Jung-Chung; Chang, Feng-Yee

2018-04-01

Bloodstream infection is a leading cause of mortality among burn patients. This study aimed to evaluate the risk factors, causative pathogens, and the relationship between bloodstream infections and other infections among burn patients from the Formosa Fun Coast Dust Explosion. This retrospective study evaluated the demographic and clinical characteristics, infection types, causative pathogen(s), and isolates' antibiotic susceptibilities from patients who were hospitalized between June 27 and September 31, 2015. Fifty-eight patients were admitted during the study period (36 males, mean age: 22.6 years). The mean burned total body surface area (TBSA) was 40% for all patients. Eighteen (31%) patients with mean TBSA of 80% had 66 episodes of bloodstream infections caused by 92 isolates. Twelve (18.2%) episodes of bloodstream infections were polymicrobial. Acinetobacter baumannii (19, 20.7%), Ralstonia pickettii (17, 18.5%), and Chryseobacterium meningosepticum (13, 14.1%) were the most common pathogens causing bloodstream infections. A high concordance rate of wound cultures with blood cultures was seen in Staphylococcus aureus (3, 75%) and C. meningosepticum (8, 61.5%) infections. However, no Ralstonia isolate was found in burn wounds of patients with Ralstonia bacteremia. A high concordance rate of central venous catheter cultures with blood cultures was noted in Ralstonia mannitolilytica (5, 62.5%) and Chryseobacterium indologenes (3, 60%) infections. Approximately 21.1% of A. baumannii strains were resistant to carbapenem. All S. aureus isolates were susceptible to methicillin. Waterborne bacteria should be considered in patients of burns with possible water contact. Empirical broad-spectrum antibiotics should be considered for patients who were hospitalized for severe sepsis, or septic shock with a large burn. Antibiotic treatment should be administered based on the specific pathogens and their detection points. Copyright © 2017. Published by Elsevier B.V.

Exome-based analysis of cardiac arrhythmia, respiratory control, and epilepsy genes in sudden unexpected death in epilepsy.

PubMed

Bagnall, Richard D; Crompton, Douglas E; Petrovski, Slavé; Lam, Lien; Cutmore, Carina; Garry, Sarah I; Sadleir, Lynette G; Dibbens, Leanne M; Cairns, Anita; Kivity, Sara; Afawi, Zaid; Regan, Brigid M; Duflou, Johan; Berkovic, Samuel F; Scheffer, Ingrid E; Semsarian, Christopher

2016-04-01

The leading cause of epilepsy-related premature mortality is sudden unexpected death in epilepsy (SUDEP). The cause of SUDEP remains unknown. To search for genetic risk factors in SUDEP cases, we performed an exome-based analysis of rare variants. Demographic and clinical information of 61 SUDEP cases were collected. Exome sequencing and rare variant collapsing analysis with 2,936 control exomes were performed to test for genes enriched with damaging variants. Additionally, cardiac arrhythmia, respiratory control, and epilepsy genes were screened for variants with frequency of <0.1% and predicted to be pathogenic with multiple in silico tools. The 61 SUDEP cases were categorized as definite SUDEP (n = 54), probable SUDEP (n = 5), and definite SUDEP plus (n = 2). We identified de novo mutations, previously reported pathogenic mutations, or candidate pathogenic variants in 28 of 61 (46%) cases. Four SUDEP cases (7%) had mutations in common genes responsible for the cardiac arrhythmia disease, long QT syndrome (LQTS). Nine cases (15%) had candidate pathogenic variants in dominant cardiac arrhythmia genes. Fifteen cases (25%) had mutations or candidate pathogenic variants in dominant epilepsy genes. No gene reached genome-wide significance with rare variant collapsing analysis; however, DEPDC5 (p = 0.00015) and KCNH2 (p = 0.0037) were among the top 30 genes, genome-wide. A sizeable proportion of SUDEP cases have clinically relevant mutations in cardiac arrhythmia and epilepsy genes. In cases with an LQTS gene mutation, SUDEP may occur as a result of a predictable and preventable cause. Understanding the genetic basis of SUDEP may inform cascade testing of at-risk family members. © 2016 American Neurological Association.

Development of a multiplex PCR assay for rapid and simultaneous detection of four genera of fish pathogenic bacteria.

PubMed

Zhang, D F; Zhang, Q Q; Li, A H

2014-11-01

Species of genus Aeromonas, Vibrio, Edwardsiella and Streptococcus are the most common fish pathogenic bacteria that cause economically devastating losses in aquaculture. A multiplex polymerase chain reaction (mPCR) was developed for the simultaneous detection and differentiation of the four genera of fish pathogenic bacteria. Through the use of genus-specific primers instead of species-specific ones, the current mPCR covered much more target bacterial species compared with previously reported species-specific mPCR methods. The specificity of the four putative genus-specific primers was validated experimentally while used exclusively (uniplex PCR) or combined (mPCR) against bacterial genomic DNA templates of the target bacteria and nontarget bacteria. The PCR amplicons for the following genera were obtained as expected: Aeromonas (875 bp), Vibrio (524 bp), Edwardsiella (302 bp) and Streptococcus (197 bp), and the fragments could be separated clearly on the agarose gel electrophoresis. The mPCR did not produce nonspecific amplification products when used to amplify 21 nontarget species of bacteria. The mPCR detection limits for each target bacterial genera were 50 colony-forming units (CFU) in pure culture and 100 CFU in fish tissue samples. In conclusion, the mPCR assay was proven to be a powerful alternative to the conventional culture-based method, given its rapid, specific, sensitive and reliable detection of target pathogens. The fish pathogenic bacteria of genus Aeromonas, Vibrio, Edwardsiella and Streptococcus frequently cause severe outbreaks of diseases in cultured fish, and the genus-specific multiplex PCR assay developed in this study can detect the bacteria of the four genera when present in the samples either alone or mixed. The mPCR assay is expected to identify the causative agents more efficiently than uniplex PCR or species-specific multiplex PCR for clinical diagnosis, resulting in the earlier implementation of control measures. This mPCR assay provides a rapid, specific and sensitive tool for the detection or identification of common fish pathogenic bacteria in aquaculture practice. © 2014 The Society for Applied Microbiology.

Common and emerging infectious diseases in the animal shelter.

PubMed

Pesavento, P A; Murphy, B G

2014-03-01

The beneficial role that animal shelters play is unquestionable. An estimated 3 to 4 million animals are cared for or placed in homes each year, and most shelters promote public health and support responsible pet ownership. It is, nonetheless, inevitable that shelters are prime examples of anthropogenic biological instability: even well-run shelters often house transient, displaced, and mixed populations of animals. Many of these animals have received minimal to no prior health care, and some have a history of scavenging or predation to survive. Overcrowding and poor shelter conditions further magnify these inherent risks to create individual, intraspecies, and interspecies stress and provide an environment conducive to exposure to numerous potentially collaborative pathogens. All of these factors can contribute to the evolution and emergence of new pathogens or to alterations in virulence of endemic pathogens. While it is not possible to effectively anticipate the timing or the pathogen type in emergence events, their sites of origin are less enigmatic, and pathologists and diagnosticians who work with sheltered animal populations have recognized several such events in the past decade. This article first considers the contribution of the shelter environment to canine and feline disease. This is followed by summaries of recent research on the pathogenesis of common shelter pathogens, as well as research that has led to the discovery of novel or emerging diseases and the methods that are used for their diagnosis and discovery. For the infectious agents that commonly affect sheltered dogs and cats, including canine distemper virus, canine influenza virus, Streptococcus spp, parvoviruses, feline herpesvirus, feline caliciviruses, and feline infectious peritonitis virus, we present familiar as well as newly recognized lesions associated with infection. Preliminary studies on recently discovered viruses like canine circovirus, canine bocavirus, and feline norovirus indicate that these pathogens can cause or contribute to canine and feline disease.

DEVELOPMENT OF A MOLECULAR METHOD TO IDENTIFY ...

EPA Pesticide Factsheets

Hepatitis E virus (HEV) is an emerging pathogen that causes significant illness in the developing world. Like the hepatitis A virus, it is transmitted via the fecal-oral route and can cause short-term, acute hepatitis. In addition, hepatitis E has been found to cause a significant rate of mortality in pregnant women. Thus far, a hepatitis E outbreak has not been reported in the U. S. although a swine variant of the virus is common in Midwestern hogs. Since it will be important to identify the presence of this virus in the water supply, we have developed and are testing a reverse transcription-polymerase chain reaction (RT-PCR) method that should be able to identify all of the known HEV strains. Develop sensitive techniques to detect and identify emerging human waterborne pathogenic viruses and viruses on the CCL.Determine effectiveness of viral indicators to measure microbial quality in water matrices.Support activities: (a) culture and distribution of mammalian cells for Agency and scientific community research needs, (b) provide operator expertise for research requiring confocal and electron microscopy, (c) glassware cleaning, sterilization and biological waste disposal for the Cincinnati EPA facility, (d) operation of infectious pathogenic suite, (e) maintenance of walk-in constant temperature rooms and (f) provide Giardia cysts.

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.

Urinary tract infections: epidemiology, mechanisms of infection and treatment options

PubMed Central

Flores-Mireles, Ana L.; Walker, Jennifer N.; Caparon, Michael; Hultgren, Scott J.

2015-01-01

Urinary tract infections (UTIs) are a severe public health problem and are caused by a range of pathogens, but most commonly by Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Enterococcus faecalis and Staphylococcus saprophyticus. High recurrence rates and increasing antimicrobial resistance among uropathogens threaten to greatly increase the economic burden of these infections. In this Review, we discuss how basic science studies are elucidating the molecular details of the crosstalk that occurs at the host–pathogen interface, as well as the consequences of these interactions for the pathophysiology of UTIs. We also describe current efforts to translate this knowledge into new clinical treatments for UTIs. PMID:25853778

Prudent Use of Antimicrobials in Exotic Animal Medicine.

PubMed

Broens, Els M; van Geijlswijk, Ingeborg M

2018-05-01

Reduction of antimicrobial use can result in reduction of resistance in commensal bacteria. In exotic animals, information on use of antimicrobials and resistance in commensals and pathogens is scarce. However, use of antimicrobials listed as critically important antimicrobials for human medicine seems high in exotic animals. Ideally, the selection of a therapy should be based on an accurate diagnosis and antimicrobial susceptibility testing. When prescribing antimicrobials based on empiricism, knowledge of the most common pathogens causing specific infections and the antimicrobial spectrum of antimicrobial agents is indispensable. Implementing antimicrobial stewardship promotes the prudent use of antimicrobials in exotic animals. Copyright © 2018 Elsevier Inc. All rights reserved.

Addressing the Analytic Challenges of Cross-Sectional Pediatric Pneumonia Etiology Data.

PubMed

Hammitt, Laura L; Feikin, Daniel R; Scott, J Anthony G; Zeger, Scott L; Murdoch, David R; O'Brien, Katherine L; Deloria Knoll, Maria

2017-06-15

Despite tremendous advances in diagnostic laboratory technology, identifying the pathogen(s) causing pneumonia remains challenging because the infected lung tissue cannot usually be sampled for testing. Consequently, to obtain information about pneumonia etiology, clinicians and researchers test specimens distant to the site of infection. These tests may lack sensitivity (eg, blood culture, which is only positive in a small proportion of children with pneumonia) and/or specificity (eg, detection of pathogens in upper respiratory tract specimens, which may indicate asymptomatic carriage or a less severe syndrome, such as upper respiratory infection). While highly sensitive nucleic acid detection methods and testing of multiple specimens improve sensitivity, multiple pathogens are often detected and this adds complexity to the interpretation as the etiologic significance of results may be unclear (ie, the pneumonia may be caused by none, one, some, or all of the pathogens detected). Some of these challenges can be addressed by adjusting positivity rates to account for poor sensitivity or incorporating test results from controls without pneumonia to account for poor specificity. However, no classical analytic methods can account for measurement error (ie, sensitivity and specificity) for multiple specimen types and integrate the results of measurements for multiple pathogens to produce an accurate understanding of etiology. We describe the major analytic challenges in determining pneumonia etiology and review how the common analytical approaches (eg, descriptive, case-control, attributable fraction, latent class analysis) address some but not all challenges. We demonstrate how these limitations necessitate a new, integrated analytical approach to pneumonia etiology data. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Addressing the Analytic Challenges of Cross-Sectional Pediatric Pneumonia Etiology Data

PubMed Central

Feikin, Daniel R.; Scott, J. Anthony G.; Zeger, Scott L.; Murdoch, David R.; O’Brien, Katherine L.; Deloria Knoll, Maria

2017-01-01

Abstract Despite tremendous advances in diagnostic laboratory technology, identifying the pathogen(s) causing pneumonia remains challenging because the infected lung tissue cannot usually be sampled for testing. Consequently, to obtain information about pneumonia etiology, clinicians and researchers test specimens distant to the site of infection. These tests may lack sensitivity (eg, blood culture, which is only positive in a small proportion of children with pneumonia) and/or specificity (eg, detection of pathogens in upper respiratory tract specimens, which may indicate asymptomatic carriage or a less severe syndrome, such as upper respiratory infection). While highly sensitive nucleic acid detection methods and testing of multiple specimens improve sensitivity, multiple pathogens are often detected and this adds complexity to the interpretation as the etiologic significance of results may be unclear (ie, the pneumonia may be caused by none, one, some, or all of the pathogens detected). Some of these challenges can be addressed by adjusting positivity rates to account for poor sensitivity or incorporating test results from controls without pneumonia to account for poor specificity. However, no classical analytic methods can account for measurement error (ie, sensitivity and specificity) for multiple specimen types and integrate the results of measurements for multiple pathogens to produce an accurate understanding of etiology. We describe the major analytic challenges in determining pneumonia etiology and review how the common analytical approaches (eg, descriptive, case-control, attributable fraction, latent class analysis) address some but not all challenges. We demonstrate how these limitations necessitate a new, integrated analytical approach to pneumonia etiology data. PMID:28575372

Molecular survey of neglected bacterial pathogens reveals an abundant diversity of species and genotypes in ticks collected from animal hosts across Romania.

PubMed

Andersson, Martin O; Tolf, Conny; Tamba, Paula; Stefanache, Mircea; Radbea, Gabriel; Frangoulidis, Dimitrios; Tomaso, Herbert; Waldenström, Jonas; Dobler, Gerhard; Chitimia-Dobler, Lidia

2018-03-20

Ticks are transmitting a wide range of bacterial pathogens that cause substantial morbidity and mortality in domestic animals. The full pathogen burden transmitted by tick vectors is incompletely studied in many geographical areas, and extensive studies are required to fully understand the diversity and distribution of pathogens transmitted by ticks. We sampled 824 ticks of 11 species collected in 19 counties in Romania. Ticks were collected mainly from dogs, but also from other domestic and wild animals, and were subjected to molecular screening for pathogens. Rickettsia spp. was the most commonly detected pathogen, occurring in 10.6% (87/824) of ticks. Several species were detected: Rickettsia helvetica, R. raoultii, R. massiliae, R. monacensis, R. slovaca and R. aeschlimannii. A single occurrence of the zoonotic bacterium Bartonella vinsonii berkhoffii was detected in a tick collected from a dog. Anaplasma phagocytophilum occurred in four samples, and sequences similar to Anaplasma marginale/ovis were abundant in ticks from ruminants. In addition, molecular screening showed that ticks from dogs were carrying an Ehrlichia species identical to the HF strain as well as the enigmatic zoonotic pathogen "Candidatus Neoehrlichia mikurensis". An organism similar to E. chaffeensis or E. muris was detected in an Ixodes ricinus collected from a fox. We describe an abundant diversity of bacterial tick-borne pathogens in ticks collected from animal hosts in Romania, both on the level of species and genotypes/strains within these species. Several findings were novel for Romania, including Bartonella vinsonii subsp. berkhoffii that causes bacteremia and endocarditis in dogs. "Candidatus Neoehrlichia mikurensis" was detected in a tick collected from a dog. Previously, a single case of infection in a dog was diagnosed in Germany. The results warrant further studies on the consequences of tick-borne pathogens in domestic animals in Romania.

Evaluation of effects of Mycoplasma mastitis on milk composition in dairy cattle from South Australia.

PubMed

Al-Farha, Abd Al-Bar; Hemmatzadeh, Farhid; Khazandi, Manouchehr; Hoare, Andrew; Petrovski, Kiro

2017-11-25

Mycoplasma mastitis is increasingly posing significant impact on dairy industry. Although the effects of major conventional mastitis pathogens on milk components has been widely addressed in the literature, limited data on the effects of different Mycoplasma and Acholeplasma spp. on milk quality and quantity is available. The aim of this study was to determine the casual relationship of Mycoplasma spp. and A. laidlawii to mastitis and compare them to subclinical mastitis caused by conventional mastitis pathogens from a single dairy herd in South Australia; Mycoplasma spp. and A. laidlawii were detected using PCR applied directly to milk samples. The herd had mastitis problem with high somatic cell count and low response rate to conventional antimicrobial therapy. A total of 288 cow-level milk samples were collected aseptically and used in this study. Conventional culture showed a predominance of coagulase-negative staphylococci, followed by coagulase-positive staphylococci, Streptococcus spp., Enterococcus spp., E. coli, and Klebsiella spp. PCR results showed a high prevalence of mycoplasmas (76.7%), including A. laidlawii (10.8%), M. bovis (6.2%), M. bovirhinis (5.6%), M. arginini (2%), and (52.1%) of cows were co-infected with two or more Mycoplasma and Acholeplasma species. Mycoplasma co-infection significantly increased somatic cell counts (SCC) similar to conventional mastitis pathogens and compared to non-infected cows with 389.3, 550.3 and 67.3 respectively; and decreased the milk yield with 29.0, 29.9 and 34.4 l, respectively. Mycoplasma co-infection caused significant increase in protein percentage, and significant decrease in fat percentage and total milk solids, similar to other conventional mastitis pathogens. In contrast, changes in milk composition and yield caused by various individual Mycoplasma species were non-significant. Mycoplasma mastitis had on-farm economic consequences similar to common conventional mastitis pathogens. Results of our study indicate that co-infection Mycoplasma mastitis caused similar effect on milk composition to other mastitis pathogens and we hope these findings raise the awareness of the importance of their detection on routine diagnostic panels.

The atypical pneumonias: clinical diagnosis and importance.

PubMed

Cunha, B A

2006-05-01

The most common atypical pneumonias are caused by three zoonotic pathogens, Chlamydia psittaci (psittacosis), Francisella tularensis (tularemia), and Coxiella burnetii (Q fever), and three nonzoonotic pathogens, Chlamydia pneumoniae, Mycoplasma pneumoniae, and Legionella. These atypical agents, unlike the typical pathogens, often cause extrapulmonary manifestations. Atypical CAPs are systemic infectious diseases with a pulmonary component and may be differentiated clinically from typical CAPs by the pattern of extrapulmonary organ involvement which is characteristic for each atypical CAP. Zoonotic pneumonias may be eliminated from diagnostic consideration with a negative contact history. The commonest clinical problem is to differentiate legionnaire's disease from typical CAP as well as from C. pneumoniae or M. pneumonia infection. Legionella is the most important atypical pathogen in terms of severity. It may be clinically differentiated from typical CAP and other atypical pathogens by the use of a weighted point system of syndromic diagnosis based on the characteristic pattern of extrapulmonary features. Because legionnaire's disease often presents as severe CAP, a presumptive diagnosis of Legionella should prompt specific testing and empirical anti-Legionella therapy such as the Winthrop-University Hospital Infectious Disease Division's weighted point score system. Most atypical pathogens are difficult or dangerous to isolate and a definitive laboratory diagnosis is usually based on indirect, i.e., direct flourescent antibody (DFA), indirect flourescent antibody (IFA). Atypical CAP is virtually always monomicrobial; increased IFA IgG tests indicate past exposure and not concurrent infection. Anti-Legionella antibiotics include macrolides, doxycycline, rifampin, quinolones, and telithromycin. The drugs with the highest level of anti-Legionella activity are quinolones and telithromycin. Therapy is usually continued for 2 weeks if potent anti-Legionella drugs are used. In adults, M. pneumoniae and C. pneumoniae may exacerbate or cause asthma. The importance of the atypical pneumonias is not related to their frequency (approximately 15% of CAPs), but to difficulties in their diagnosis, and their nonresponsiveness to beta-lactam therapy. Because of the potential role of C. pneumoniae in coronary artery disease and multiple sclerosis (MS), and the role of M. pneumoniae and C. pneumoniae in causing or exacerbating asthma, atypical CAPs also have public health importance.

An Improved Medium for Growing Staphylococcus aureus Biofilm

DTIC Science & Technology

2012-04-19

implantitis, chronic wound infections , chronic rhinosinusitis, endocarditis , and ocular infections (Archer et al., 2011). In addition, emerging evidence...causes of human bacterial infections , Staphylococcus aureus, a gram positive organism, is a ubiquitous oppor tunistic pathogen that commonly colonizes...resistant to antibiotic therapy. It has been shown that S. aureus biofilms are involved in oste omyelitis; indwelling medical device infections ; and peri

Marker development, saturation mapping, and high-resolution mapping of the Septoria nodorum blotch susceptibility gene Snn3-B1 in wheat

USDA-ARS?s Scientific Manuscript database

Septoria nodorum blotch (SNB), caused by Parastagonospora nodorum, is a severe foliar and glume disease on durum and common wheat. Pathogen-produced necrotrophic effectors (NEs) are the major determinants for SNB on leaves. One such NE is SnTox3, which evokes programmed cell death and leads to dis...

BIOLOGY, BIOLOGICAL CONTROL AND MOLECULAR GENETICS OF ROOT DISEASES OF WHEAT AND BARLEY. BIOLOGY, BIOLOGICAL CONTROL AND MOLECULAR GENETICS OF ROOT DISEASES OF WHEAT AND BARLEY.

USDA-ARS?s Scientific Manuscript database

Root diseases cause billions of dollars annually in losses to cereal growers. Resistance to foliar diseases is common, but resistance to root diseases is rare. Soilborne pathogens of cereals are managed through crop rotation, tillage, and chemical seed treatments. However, plants also defend themsel...

Does Fusarium-caused seed mortality contribute to Bromus tectorum stand failure in the Great Basin?

Treesearch

S. E. Meyer; J.-L. Franke; O. W. Baughman; J. Beckstead; B. Geary

2014-01-01

Bromus tectorum (cheatgrass, downy brome) is an important invader in western North America, dominating millions of hectares of former semi-arid shrubland. Stand failure or 'die-off' is relatively common in monocultures of this annual grass. The study reported here investigated whether soil-borne pathogens could be causal agents in die-offs. Soils from two die...

Allozyme-Specific Modification of a Maize Seed Chitinase by a Protein Secreted by the Fungal Pathogen Stenocarpella maydis

USDA-ARS?s Scientific Manuscript database

Stenocarpella maydis causes both dry-ear rot and stalk rot of maize. Maize inbreds have varying levels of resistance to S. maydis ear rot. The genetic basis of resistance appears to rely on multiple genetic factors, none of which are known. The commonly used stiff stalk inbred B73 has been shown ...

Characterization of free lytic bacteriophages isolated from compost against O145 Shiga toxin-producing Escherichia coli (STEC) as a potential biocontrol agent

USDA-ARS?s Scientific Manuscript database

Shiga toxin-producing E. coli (STEC), one of the most prevalent foodborne pathogens, are notorious for hemolytic uremic syndrome (HUS) and causing high mortality among children and the elder population after infection. Besides O157 STEC, non-O157 STEC—particularly serogroup O145—is commonly associat...

Transcriptome profiling of soybean (Glycine max) roots challenged with pathogenic and non-pathogenic isolates of Fusarium oxysporum.

PubMed

Lanubile, Alessandra; Muppirala, Usha K; Severin, Andrew J; Marocco, Adriano; Munkvold, Gary P

2015-12-21

Fusarium oxysporum is one of the most common fungal pathogens causing soybean root rot and seedling blight in U.S.A. In a recent study, significant variation in aggressiveness was observed among isolates of F. oxysporum collected from roots in Iowa, ranging from highly pathogenic to weakly or non-pathogenic isolates. We used RNA-seq analysis to investigate the molecular aspects of the interactions of a partially resistant soybean genotype with non-pathogenic/pathogenic isolates of F. oxysporum at 72 and 96 h post inoculation (hpi). Markedly different gene expression profiles were observed in response to the two isolates. A peak of highly differentially expressed genes (HDEGs) was triggered at 72 hpi in soybean roots and the number of HDEGs was about eight times higher in response to the pathogenic isolate compared to the non-pathogenic one (1,659 vs. 203 HDEGs, respectively). Furthermore, the magnitude of induction was much greater in response to the pathogenic isolate. This response included a stronger activation of defense-related genes, transcription factors, and genes involved in ethylene biosynthesis, secondary and sugar metabolism. The obtained data provide an important insight into the transcriptional responses of soybean-F. oxysporum interactions and illustrate the more drastic changes in the host transcriptome in response to the pathogenic isolate. These results may be useful in the developing new methods of broadening resistance of soybean to F. oxysporum, including the over-expression of key soybean genes.

A Mayan founder mutation is a common cause of deafness in Guatemala.

PubMed

Carranza, C; Menendez, I; Herrera, M; Castellanos, P; Amado, C; Maldonado, F; Rosales, L; Escobar, N; Guerra, M; Alvarez, D; Foster, J; Guo, S; Blanton, S H; Bademci, G; Tekin, M

2015-09-08

Over 5% of the world's population has varying degrees of hearing loss. Mutations in GJB2 are the most common cause of autosomal recessive non-syndromic hearing loss (ARNHL) in many populations. The frequency and type of mutations are influenced by ethnicity. Guatemala is a multi-ethnic country with four major populations: Maya, Ladino, Xinca, and Garifuna. To determine the mutation profile of GJB2 in a ARNHL population from Guatemala, we sequenced both exons of GJB2 in 133 unrelated families. A total of six pathogenic variants were detected. The most frequent pathogenic variant is c.131G>A (p.Trp44*) detected in 21 of 266 alleles. We show that c.131G>A is associated with a conserved haplotype in Guatemala suggesting a single founder. The majority of Mayan population lives in the west region of the country from where all c.131G>A carriers originated. Further analysis of genome-wide variation of individuals carrying the c.131G>A mutation compared with those of Native American, European, and African populations shows a close match with the Mayan population. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

De novo REEP2 missense mutation in pure hereditary spastic paraplegia.

PubMed

Roda, Ricardo H; Schindler, Alice B; Blackstone, Craig

2017-05-01

Alterations in proteins that regulate endoplasmic reticulum morphology are common causes of hereditary spastic paraplegia (SPG1-78, plus others). Mutations in the REEP1 gene that encodes an endoplasmic reticulum-shaping protein are well-known causes of SPG31, a common autosomal dominant spastic paraplegia. A closely-related gene, REEP2, is mutated in SPG72, with both autosomal and recessive inheritances. Here, we report a patient with a pure hereditary spastic paraplegia due to a de novo missense mutation (c.119T > G, p.Met40Arg) in REEP2 at a highly-conserved residue very close to another known pathogenic missense change. This represents only the second autosomal dominant SPG72 missense mutation reported.

Concurrent Drought Stress and Vascular Pathogen Infection Induce Common and Distinct Transcriptomic Responses in Chickpea

PubMed Central

Sinha, Ranjita; Gupta, Aarti; Senthil-Kumar, Muthappa

2017-01-01

Chickpea (Cicer arietinum); the second largest legume grown worldwide is prone to drought and various pathogen infections. These drought and pathogen stresses often occur concurrently in the field conditions. However, the molecular events in response to that are largely unknown. The present study examines the transcriptome dynamics in chickpea plants exposed to a combination of water-deficit stress and Ralstonia solanacearum infection. R. solanacearum is a potential wilt disease causing pathogen in chickpea. Drought stressed chickpea plants were infected with this pathogen and the plants were allowed to experience progressive drought with 2 and 4 days of R. solanacearum infection called short duration stress (SD stresses) and long duration stress (LD stresses), respectively. Our study showed that R. solanacearum multiplication decreased under SD-combined stress compared to SD-pathogen but there was no significant change in LD-combined stress compared to LD-pathogen. The microarray analysis during these conditions showed that 821 and 1039 differentially expressed genes (DEGs) were unique to SD- and LD-combined stresses, respectively, when compared with individual stress conditions. Three and fifteen genes were common among all the SD-stress treatments and LD-stress treatments, respectively. Genes involved in secondary cell wall biosynthesis, alkaloid biosynthesis, defense related proteins, and osmo-protectants were up-regulated during combined stress. The expression of genes involved in lignin and cellulose biosynthesis were specifically up-regulated in SD-combined, LD-combined, and LD-pathogen stress. A close transcriptomic association of LD-pathogen stress with SD-combined stress was observed in this study which indicates that R. solanacearum infection also exerts drought stress along with pathogen stress thus mimics combined stress effect. Furthermore the expression profiling of candidate genes using real-time quantitative PCR validated the microarray data. The study showed that down-regulation of defense-related genes during LD-combined stress resulted in an increased bacterial multiplication as compared to SD-combined stress. Overall, our study highlights a sub-set of DEGs uniquely expressed in response to combined stress, which serve as potential candidates for further functional characterization to delineate the molecular response of the plant to concurrent drought-pathogen stress. PMID:28382041

Dermatological infectiology--Quo vadis? Symposium, Ruhr-University, September 29-30, 2000. Abstracts.

PubMed

2000-11-30

Infectious diseases remain a major cause of morbidity and mortality in the year 2000. 17 million deaths per year or roughly a third of all deaths are caused by infections. Infectious diseases also pose a serious economic threat. While many well-established pathogens have not been contained several new infectious agents have been discovered within the past 27 years which include rotavirus, legionella, HIV, ebola, campylobacter, helicobacter, nipah, HHV8, hepatitis C, and many others. Additionally many new pathogens have emerged as serious threats to the ever-growing number of immuno-compromised patients. Infectious etiologies have been found for many common diseases (certain leukemias, duodenal ulcers, etcetera). It is likely that infections are at least co-factors for many other diseases (transplant-associated atherosclerosis). Only specialized care and multi-disciplinary collaboration will enable us to cope with current problems and the inevitable emergence of new infectious diseases.

Genomic identification of potential targets unique to Candida albicans for the discovery of antifungal agents.

PubMed

Tripathi, Himanshu; Luqman, Suaib; Meena, Abha; Khan, Feroz

2014-01-01

Despite of modern antifungal therapy, the mortality rates of invasive infection with human fungal pathogen Candida albicans are up to 40%. Studies suggest that drug resistance in the three most common species of human fungal pathogens viz., C. albicans, Aspergillus fumigatus (causing mortality rate up to 90%) and Cryptococcus neoformans (causing mortality rate up to 70%) is due to mutations in the target enzymes or high expression of drug transporter genes. Drug resistance in human fungal pathogens has led to an imperative need for the identification of new targets unique to fungal pathogens. In the present study, we have used a comparative genomics approach to find out potential target proteins unique to C. albicans, an opportunistic fungus responsible for severe infection in immune-compromised human. Interestingly, many target proteins of existing antifungal agents showed orthologs in human cells. To identify unique proteins, we have compared proteome of C. albicans [SC5314] i.e., 14,633 total proteins retrieved from the RefSeq database of NCBI, USA with proteome of human and non-pathogenic yeast Saccharomyces cerevisiae. Results showed that 4,568 proteins were identified unique to C. albicans as compared to those of human and later when these unique proteins were compared with S. cerevisiae proteome, finally 2,161 proteins were identified as unique proteins and after removing repeats total 1,618 unique proteins (42 functionally known, 1,566 hypothetical and 10 unknown) were selected as potential antifungal drug targets unique to C. albicans.

Whole genome sequencing revealed host adaptation-focused genomic plasticity of pathogenic Leptospira

PubMed Central

Xu, Yinghua; Zhu, Yongzhang; Wang, Yuezhu; Chang, Yung-Fu; Zhang, Ying; Jiang, Xiugao; Zhuang, Xuran; Zhu, Yongqiang; Zhang, Jinlong; Zeng, Lingbing; Yang, Minjun; Li, Shijun; Wang, Shengyue; Ye, Qiang; Xin, Xiaofang; Zhao, Guoping; Zheng, Huajun; Guo, Xiaokui; Wang, Junzhi

2016-01-01

Leptospirosis, caused by pathogenic Leptospira spp., has recently been recognized as an emerging infectious disease worldwide. Despite its severity and global importance, knowledge about the molecular pathogenesis and virulence evolution of Leptospira spp. remains limited. Here we sequenced and analyzed 102 isolates representing global sources. A high genomic variability were observed among different Leptospira species, which was attributed to massive gene gain and loss events allowing for adaptation to specific niche conditions and changing host environments. Horizontal gene transfer and gene duplication allowed the stepwise acquisition of virulence factors in pathogenic Leptospira evolved from a recent common ancestor. More importantly, the abundant expansion of specific virulence-related protein families, such as metalloproteases-associated paralogs, were exclusively identified in pathogenic species, reflecting the importance of these protein families in the pathogenesis of leptospirosis. Our observations also indicated that positive selection played a crucial role on this bacteria adaptation to hosts. These novel findings may lead to greater understanding of the global diversity and virulence evolution of Leptospira spp. PMID:26833181

Immunity to intestinal pathogens: lessons learned from Salmonella

PubMed Central

McSorley, Stephen J.

2014-01-01

Summary Salmonella are a common source of food or water-borne infection and cause a wide range of clinical disease in human and animal hosts. Salmonella are relatively easy to culture and manipulate in a laboratory setting, and the infection of laboratory animals induces robust innate and adaptive immune responses. Thus, immunologists have frequently turned to Salmonella infection models to expand understanding of immunity to intestinal pathogens. In this review, I summarize current knowledge of innate and adaptive immunity to Salmonella and highlight features of this response that have emerged from recent studies. These include the heterogeneity of the antigen-specific T-cell response to intestinal infection, the prominence of microbial mechanisms to impede T and B-cell responses, and the contribution of non-cognate pathways for elicitation of T-cell effector functions. Together, these different issues challenge an overly simplistic view of host-pathogen interaction during mucosal infection but also allow deeper insight into the real-world dynamic of protective immunity to intestinal pathogens. PMID:24942689

Core Proteomic Analysis of Unique Metabolic Pathways of Salmonella enterica for the Identification of Potential Drug Targets.

PubMed

Uddin, Reaz; Sufian, Muhammad

2016-01-01

Infections caused by Salmonella enterica, a Gram-negative facultative anaerobic bacteria belonging to the family of Enterobacteriaceae, are major threats to the health of humans and animals. The recent availability of complete genome data of pathogenic strains of the S. enterica gives new avenues for the identification of drug targets and drug candidates. We have used the genomic and metabolic pathway data to identify pathways and proteins essential to the pathogen and absent from the host. We took the whole proteome sequence data of 42 strains of S. enterica and Homo sapiens along with KEGG-annotated metabolic pathway data, clustered proteins sequences using CD-HIT, identified essential genes using DEG database and discarded S. enterica homologs of human proteins in unique metabolic pathways (UMPs) and characterized hypothetical proteins with SVM-prot and InterProScan. Through this core proteomic analysis we have identified enzymes essential to the pathogen. The identification of 73 enzymes common in 42 strains of S. enterica is the real strength of the current study. We proposed all 73 unexplored enzymes as potential drug targets against the infections caused by the S. enterica. The study is comprehensive around S. enterica and simultaneously considered every possible pathogenic strain of S. enterica. This comprehensiveness turned the current study significant since, to the best of our knowledge it is the first subtractive core proteomic analysis of the unique metabolic pathways applied to any pathogen for the identification of drug targets. We applied extensive computational methods to shortlist few potential drug targets considering the druggability criteria e.g. Non-homologous to the human host, essential to the pathogen and playing significant role in essential metabolic pathways of the pathogen (i.e. S. enterica). In the current study, the subtractive proteomics through a novel approach was applied i.e. by considering only proteins of the unique metabolic pathways of the pathogens and mining the proteomic data of all completely sequenced strains of the pathogen, thus improving the quality and application of the results. We believe that the sharing of the knowledge from this study would eventually lead to bring about novel and unique therapeutic regimens against the infections caused by the S. enterica.

Secondary Bacterial Infections Associated with Influenza Pandemics

PubMed Central

Morris, Denise E.; Cleary, David W.; Clarke, Stuart C.

2017-01-01

Lower and upper respiratory infections are the fourth highest cause of global mortality (Lozano et al., 2012). Epidemic and pandemic outbreaks of respiratory infection are a major medical concern, often causing considerable disease and a high death toll, typically over a relatively short period of time. Influenza is a major cause of epidemic and pandemic infection. Bacterial co/secondary infection further increases morbidity and mortality of influenza infection, with Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus reported as the most common causes. With increased antibiotic resistance and vaccine evasion it is important to monitor the epidemiology of pathogens in circulation to inform clinical treatment and development, particularly in the setting of an influenza epidemic/pandemic. PMID:28690590

Meningitis and septicemia caused by nontypeable Haemophilus influenzae in a previously healthy 2-year-old girl.

PubMed

Ito, Takao; Shibata, Hironori; Nakazawa, Mie; Myokai, Michiko; Ikegaya, Kazuko; Tsuchiya, Ken; Kamimaki, Tsutomu

2011-08-01

Nontypeable Haemophilus influenzae (NTHi) commonly colonizes the upper respiratory tract of children and causes otitis media, sinusitis, and bronchitis. Invasive NTHi diseases such as meningitis and septicemia have rarely been reported, especially in children with underlying predisposing conditions such as head trauma and immune compromise. However, we report a previously healthy 2-year-old girl who developed meningitis and septicemia caused by NTHi biotype ΙΙΙ. She was treated with dexamethasone, meropenem, and ceftriaxone, and recovered uneventfully. We wish to emphasize that NTHi should be borne in mind as a potential pathogen that can cause meningitis and septicemia, even in previously healthy children.

Parallel Evolution of Two Clades of an Atlantic-Endemic Pathogenic Lineage of Vibrio parahaemolyticus by Independent Acquisition of Related Pathogenicity Islands

PubMed Central

Xu, Feng; Drees, Kevin P.; Sebra, Robert P.; Jones, Stephen H.

2017-01-01

ABSTRACT Shellfish-transmitted Vibrio parahaemolyticus infections have recently increased from locations with historically low disease incidence, such as the Northeast United States. This change coincided with a bacterial population shift toward human-pathogenic variants occurring in part through the introduction of several Pacific native lineages (ST36, ST43, and ST636) to nearshore areas off the Atlantic coast of the Northeast United States. Concomitantly, ST631 emerged as a major endemic pathogen. Phylogenetic trees of clinical and environmental isolates indicated that two clades diverged from a common ST631 ancestor, and in each of these clades, a human-pathogenic variant evolved independently through acquisition of distinct Vibrio pathogenicity islands (VPaI). These VPaI differ from each other and bear little resemblance to hemolysin-containing VPaI from isolates of the pandemic clonal complex. Clade I ST631 isolates either harbored no hemolysins or contained a chromosome I-inserted island we call VPaIβ that encodes a type 3 secretion system (T3SS2β) typical of Trh hemolysin producers. The more clinically prevalent and clonal ST631 clade II had an island we call VPaIγ that encodes both tdh and trh and that was inserted in chromosome II. VPaIγ was derived from VPaIβ but with some additional acquired elements in common with VPaI carried by pandemic isolates, exemplifying the mosaic nature of pathogenicity islands. Genomics comparisons and amplicon assays identified VPaIγ-type islands containing tdh inserted adjacent to the ure cluster in the three introduced Pacific and most other emergent lineages that collectively cause 67% of infections in the Northeast United States as of 2016. IMPORTANCE The availability of three different hemolysin genotypes in the ST631 lineage provided a unique opportunity to employ genome comparisons to further our understanding of the processes underlying pathogen evolution. The fact that two different pathogenic clades arose in parallel from the same potentially benign lineage by independent VPaI acquisition is surprising considering the historically low prevalence of community members harboring VPaI in waters along the Northeast U.S. coast that could serve as the source of this material. This illustrates a possible predisposition of some lineages to not only acquire foreign DNA but also become human pathogens. Whereas the underlying cause for the expansion of V. parahaemolyticus lineages harboring VPaIγ along the U.S. Atlantic coast and spread of this element to multiple lineages that underlies disease emergence is not known, this work underscores the need to define the environment factors that favor bacteria harboring VPaI in locations of emergent disease. PMID:28687650

[Reccurent mycobacterial diseases in patients with impaired axis IL-12/INF-gamma].

PubMed

Strach, Magdalena; Nalepa, Piotr; Sulicka-Grodzicka, Joanna; Kierzkowska, Izabella; Siedlar, Maciej; Grodzicki, Tomasz

2013-01-01

Mycobacteria is a large group of pathogens that are common in environment, in soil and tap water. Although mycobacteria [non tuberculosis mycobacteria] can inhabit body surface without causing any disease in the circumstances of primary or secondary immunodeficiency can cause clinically significant organ or systemic damage. Defect of IL-12/INFgamma axis is an example of primary immunodeficiency that predispose to mycobacterial infections while protection against other microorganisms is not damaged. We present review of known defects of IL-12/IFNgamma axis and brief presentation of our own experience.

Dermatologic Infectious Diseases in International Travelers.

PubMed

Wilson, Mary E.; Chen, Lin H.

2004-02-01

Skin lesions provide an important clue to the diagnoses of many infections in returned travelers. New information related to epidemiology, recognition, diagnosis, or management is described for the systemic infections--dengue fever, several of the rickettsial infections, African trypanosomiasis, and coccidioidomycosis. Many pathogens cause focal skin findings. Recent findings are presented for cutaneous leishmaniasis, Buruli ulcer, gnatho-stomiasis, cutaneous larva migrans, myiasis, tungiasis, and scabies. This paper describes the most common skin problems in returning travelers and outlines the types of infections that cause skin lesions, as defined by morphologic characteristics.

Prediction of Pan-Specific B-Cell Epitopes From Nucleocapsid Protein of Hantaviruses Causing Hantavirus Cardiopulmonary Syndrome.

PubMed

Kalaiselvan, Sagadevan; Sankar, Sathish; Ramamurthy, Mageshbabu; Ghosh, Asit Ranjan; Nandagopal, Balaji; Sridharan, Gopalan

2017-08-01

Hantaviruses are emerging viral pathogens that causes hantavirus cardiopulmonary syndrome (HCPS) in the Americas, a severe, sometimes fatal, respiratory disease in humans with a case fatality rate of ≥50%. IgM and IgG-based serological detection methods are the most common approaches used for laboratory diagnosis of hantaviruses. Such emerging viral pathogens emphasizes the need for improved rapid diagnostic devices and vaccines incorporating pan-specific epitopes of genotypes. We predicted linear B-cell epitopes for hantaviruses that are specific to genotypes causing HCPS in humans using in silico prediction servers. We modeled the Andes and Sin Nombre hantavirus nucleocapsid protein to locate the identified epitopes. Based on the mean percent prediction probability score, epitope IMASKSVGS/TAEEKLKKKSAF was identified as the best candidate B-cell epitope specific for hantaviruses causing HCPS. Promiscuous epitopes were identified in the C-terminal of the protein. Our study for the first time has reported pan-specific B-cell epitopes for developing immunoassays in the detection of antibodies to hantaviruses causing HCPS. Identification of epitopes with pan-specific recognition of all genotypes causing HCPS could be valuable for the development of immunodiagnositic tools toward pan-detection of hantavirus antibodies in ELISA. J. Cell. Biochem. 118: 2320-2324, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Fatty liver and drugs: the two sides of the same coin.

PubMed

Miele, L; Liguori, A; Marrone, G; Biolato, M; Araneo, C; Vaccaro, F G; Gasbarrini, A; Grieco, A

2017-03-01

Drug-induced liver injury (DILI) is a common and underestimated cause of liver disease. Several drugs and other xenobiotics can be the cause of different clinicopathologic patterns of liver disease. Steatosis and steatohepatitis are rare but well-documented types of DILI. Over the past decades commonly used drugs like amiodarone, tamoxifen, irinotecan, methotrexate, valproic acid and glucocorticoids have been recognized to be associated with steatosis. Even though the pathophysiological pathways are still only partially understood, inhibition of mitochondrial beta-oxidation, reduced very low-density lipoprotein secretion, insulin resistance induction and increased de novo synthesis or increased liver uptake of fatty acids are considered the main pathogenic mechanisms through which drugs can lead to hepatic steatosis. On the other hand, fatty liver itself is a very common clinical condition, and there is a growing awareness of the potential risk factors for DILI due to the underlying metabolic condition itself.

A comparative hidden Markov model analysis pipeline identifies proteins characteristic of cereal-infecting fungi

PubMed Central

2013-01-01

Background Fungal pathogens cause devastating losses in economically important cereal crops by utilising pathogen proteins to infect host plants. Secreted pathogen proteins are referred to as effectors and have thus far been identified by selecting small, cysteine-rich peptides from the secretome despite increasing evidence that not all effectors share these attributes. Results We take advantage of the availability of sequenced fungal genomes and present an unbiased method for finding putative pathogen proteins and secreted effectors in a query genome via comparative hidden Markov model analyses followed by unsupervised protein clustering. Our method returns experimentally validated fungal effectors in Stagonospora nodorum and Fusarium oxysporum as well as the N-terminal Y/F/WxC-motif from the barley powdery mildew pathogen. Application to the cereal pathogen Fusarium graminearum reveals a secreted phosphorylcholine phosphatase that is characteristic of hemibiotrophic and necrotrophic cereal pathogens and shares an ancient selection process with bacterial plant pathogens. Three F. graminearum protein clusters are found with an enriched secretion signal. One of these putative effector clusters contains proteins that share a [SG]-P-C-[KR]-P sequence motif in the N-terminal and show features not commonly associated with fungal effectors. This motif is conserved in secreted pathogenic Fusarium proteins and a prime candidate for functional testing. Conclusions Our pipeline has successfully uncovered conservation patterns, putative effectors and motifs of fungal pathogens that would have been overlooked by existing approaches that identify effectors as small, secreted, cysteine-rich peptides. It can be applied to any pathogenic proteome data, such as microbial pathogen data of plants and other organisms. PMID:24252298

Cryptosporidium species from common edible bivalves in Manila Bay, Philippines.

PubMed

Pagoso, Edison Jay A; Rivera, Windell L

2017-06-15

Manila Bay is one of the major propagation sites of edible bivalves in the Philippines. Studies have shown that bivalves might be contaminated with human pathogens like the protozoan parasite Cryptosporidium, one of the major causes of gastroenteritis in the world. In this study, Cryptosporidium from four species of edible bivalves were isolated using a combination of sucrose flotation and immunomagnetic separation. Using direct fluorescent antibody test, Cryptosporidium oocysts were found in 67 out of 144 samples collected. DNA sequence analysis of the 18S rRNA gene of the isolates detected C. parvum and C. hominis (major causes of human cryptosporidiosis) and C. meleagridis (causes infection in avian species). Analysis of the 60kDa glycoprotein gene further confirmed the genotypes of the Cryptosporidium isolates. This study is the first to provide baseline information on Cryptosporidium contamination of Manila Bay where bivalves are commonly cultured. Copyright © 2017 Elsevier Ltd. All rights reserved.

The genome sequence of avian pathogenic Escherichia coli strain O1:K1:H7 shares strong similarities with human extraintestinal pathogenic E. coli genomes.

PubMed

Johnson, Timothy J; Kariyawasam, Subhashinie; Wannemuehler, Yvonne; Mangiamele, Paul; Johnson, Sara J; Doetkott, Curt; Skyberg, Jerod A; Lynne, Aaron M; Johnson, James R; Nolan, Lisa K

2007-04-01

Escherichia coli strains that cause disease outside the intestine are known as extraintestinal pathogenic E. coli (ExPEC) and include human uropathogenic E. coli (UPEC) and avian pathogenic E. coli (APEC). Regardless of host of origin, ExPEC strains share many traits. It has been suggested that these commonalities may enable APEC to cause disease in humans. Here, we begin to test the hypothesis that certain APEC strains possess potential to cause human urinary tract infection through virulence genotyping of 1,000 APEC and UPEC strains, generation of the first complete genomic sequence of an APEC (APEC O1:K1:H7) strain, and comparison of this genome to all available human ExPEC genomic sequences. The genomes of APEC O1 and three human UPEC strains were found to be remarkably similar, with only 4.5% of APEC O1's genome not found in other sequenced ExPEC genomes. Also, use of multilocus sequence typing showed that some of the sequenced human ExPEC strains were more like APEC O1 than other human ExPEC strains. This work provides evidence that at least some human and avian ExPEC strains are highly similar to one another, and it supports the possibility that a food-borne link between some APEC and UPEC strains exists. Future studies are necessary to assess the ability of APEC to overcome the hurdles necessary for such a food-borne transmission, and epidemiological studies are required to confirm that such a phenomenon actually occurs.

Eicosanoids and Respiratory Viral Infection: Coordinators of Inflammation and Potential Therapeutic Targets

PubMed Central

McCarthy, Mary K.; Weinberg, Jason B.

2012-01-01

Viruses are frequent causes of respiratory infection, and viral respiratory infections are significant causes of hospitalization, morbidity, and sometimes mortality in a variety of patient populations. Lung inflammation induced by infection with common respiratory pathogens such as influenza and respiratory syncytial virus is accompanied by increased lung production of prostaglandins and leukotrienes, lipid mediators with a wide range of effects on host immune function. Deficiency or pharmacologic inhibition of prostaglandin and leukotriene production often results in a dampened inflammatory response to acute infection with a respiratory virus. These mediators may, therefore, serve as appealing therapeutic targets for disease caused by respiratory viral infection. PMID:22665949

Differentiation of Mycoplasma gallisepticum vaccine strains ts-11 and 6/85 from commonly used Mycoplasma gallisepticum challenge strains by PCR.

PubMed

Evans, J D; Leigh, S A

2008-09-01

Mycoplasma gallisepticum (MG) is an important avian pathogen causing significant economic losses within the poultry industry. In an effort to develop tools to aid in MG research and diagnostics, we have compared sequences of the attenuated MG vaccine strain ts-11 to those of commonly used pathogenic challenge strains in search of a simple means of differentiation. Via gapA sequence alignments and comparisons, we have identified and designed primers facilitating strain differentiation. When applied to conventional polymerase chain reaction (PCR) assay at low annealing temperature, the primer sets allow for the differentiation of MG attenuated vaccine strains ts-11 as well as the attenuated MG vaccine strain 6/85 from the commonly utilized MG challenge strains R(low), R, and S6. Conventional PCR differentiation is based on the visualization of sole products with the attenuated MG strains ts-11 and 6/85 and the lack of the corresponding products from MG strains R(low), R, and S6. When applied to MG strain F, product visualization varies with the applied primer set. The differentiation of MG strains ts-11 and 6/85 from the pathogenic challenge strains was also accomplished via real-time analyses, however, the primer sets were not able to differentiate MG strains ts-11 and 6/85 from selected MG field isolates.

[Analysis of pathogenic bacteria and drug resistance in neonatal purulent meningitis].

PubMed

Zhu, Minli; Hu, Qianhong; Mai, Jingyun; Lin, Zhenlang

2015-01-01

To study the clinical characteristics, pathogenic bacteria, and antibiotics resistance of neonatal purulent meningitis in order to provide the guide for early diagnosis and appropriate treatment. A retrospective review was performed and a total of 112 cases of neonatal purulent meningitis (male 64, female 58) were identified in the neonatal intensive care unit of Yuying Children's Hospital of Wenzhou Medical University seen from January 1, 2004 to December 31, 2013. The clinical information including pathogenic bacterial distribution, drug sensitivity, head imageology and therapeutic outcome were analyzed. Numeration data were shown in ratio and chi square test was applied for group comparison. Among 112 cases, 46 were admitted from 2004 to 2008 and 66 from 2009 to 2013, 23 patients were preterm and 89 were term, 20 were early onset (occurring within 3 days of life) and 92 were late onset meningitis (occurring after 3 days of life). In 62 (55.4%) cases the pathogens were Gram-positive bacteria and in 50 (44.6%) were Gram-negative bacteria. The five most frequently isolated pathogens were Escherichia coli (32 cases, 28.6%), coagulase-negative staphylococcus (CNS, 20 cases, 17.9%), Streptococcus (18 cases, 16.1%, Streptococcus agalactiae 15 cases), Enterococci (13 cases, 11.6%), Staphylococcus aureus (9 cases, 8.0%). Comparison of pathogenic bacterial distribution between 2004-2008 and 2009-2013 showed that Gram-positive bacteria accounted for more than 50% in both period. Escherichia coli was the most common bacterium, followed by Streptococcus in last five years which was higher than the first five years (22.7% (15/66) vs. 6.5% (3/46), χ(2) = 5.278, P < 0.05). Klebsiella pneumoniae was more common isolate in preterm infants than in term infants (13.0% (3/23) vs. 1.1% (1/89), χ(2) = 7.540, P < 0.05). Streptococcus (most were Streptococcus agalactiae) was the most common bacteria in early onset meningitis and higher than those in late onset meningitis (35.0% (7/20) vs. 12.0% (11/92), χ(2) = 4.872, P < 0.05). Drug sensitivity tests showed that all the Gram-positive bacterial isolates were sensitive to linezolid. Staphylococci were resistant to penicillin, and most of them were resistant to erythromycin, oxacillin and cefazolin; 77.8%of CNS isolates were methicillin-resistant staphylococcus. No Streptococcus and Enterococcus faecalis was resistant to penicillin. None of enterococci was resistant to vancomycin. Among the Gram-negative bacterial isolates, more than 40% of Escherichia coli were resistant to commonly used cephalosporins such as cefuroxime, cefotaxime and ceftazidime, and all of them were sensitive to amikacin, cefoperazone sulbactam and imipenem. Isolates of Klebsiella pneumoniae were all resistant to ampicillin, cefuroxime, cefotaxime and ceftazidime, but none of them was resistant to piperacillin tazobactam and imipenem. Of the 112 patients, 69 were cured, 23 improved, 9 uncured and 11 died. There were 47 cases (42.0%) with poor prognosis, they had abnormal head imageology, severe complications and some cases died, 13 of 18 (72.2%) patients with meningitis caused by Streptococcus died. Escherichia coli, CNS and Streptococcus are the predominant pathogens responsible for neonatal purulent meningitis over the past ten years. There were increasing numbers of cases with Streptococcus meningitis which are more common in early onset meningitis with adverse outcome, therefore careful attention should be paid in clinic. Linezolid should be used as a new choice in intractable neonatal purulent meningitis cases caused by gram positive bacteria.

Infection with Pathogens Transmitted Commonly Through Food and the Effect of Increasing Use of Culture-Independent Diagnostic Tests on Surveillance--Foodborne Diseases Active Surveillance Network, 10 U.S. Sites, 2012-2015.

PubMed

Huang, Jennifer Y; Henao, Olga L; Griffin, Patricia M; Vugia, Duc J; Cronquist, Alicia B; Hurd, Sharon; Tobin-D'Angelo, Melissa; Ryan, Patricia; Smith, Kirk; Lathrop, Sarah; Zansky, Shelley; Cieslak, Paul R; Dunn, John; Holt, Kristin G; Wolpert, Beverly J; Patrick, Mary E

2016-04-15

To evaluate progress toward prevention of enteric and foodborne illnesses in the United States, the Foodborne Diseases Active Surveillance Network (FoodNet) monitors the incidence of laboratory-confirmed infections caused by nine pathogens transmitted commonly through food in 10 U.S. sites. This report summarizes preliminary 2015 data and describes trends since 2012. In 2015, FoodNet reported 20,107 confirmed cases (defined as culture-confirmed bacterial infections and laboratory-confirmed parasitic infections), 4,531 hospitalizations, and 77 deaths. FoodNet also received reports of 3,112 positive culture-independent diagnostic tests (CIDTs) without culture-confirmation, a number that has markedly increased since 2012. Diagnostic testing practices for enteric pathogens are rapidly moving away from culture-based methods. The continued shift from culture-based methods to CIDTs that do not produce the isolates needed to distinguish between strains and subtypes affects the interpretation of public health surveillance data and ability to monitor progress toward prevention efforts. Expanded case definitions and strategies for obtaining bacterial isolates are crucial during this transition period.

Antibacterial isoeugenol coating on stainless steel and polyethylene surfaces prevents biofilm growth.

PubMed

Nielsen, C K; Subbiahdoss, G; Zeng, G; Salmi, Z; Kjems, J; Mygind, T; Snabe, T; Meyer, R L

2018-01-01

Pathogenic bacteria can spread between individuals or between food items via the surfaces they share. Limiting the survival of pathogens on surfaces, therefore, presents an opportunity to limit at least one route of how pathogens spread. In this study, we propose that a simple coating with the essential oil isoeugenol can be used to circumvent the problem of bacterial transfer via surfaces. Two commonly used materials, stainless steel and polyethylene, were coated by physical adsorption, and the coatings were characterized by Raman spectroscopy, atomic force microscopy and water contact angle measurements. We quantified and visualized the colonization of coated and uncoated surfaces by three bacteria: Staphylococcus aureus, Listeria monocytogenes and Pseudomonas fluorescens. No viable cells were detected on surfaces coated with isoeugenol. The isoeugenol coating prepared with simple adsorption proved effective in preventing biofilm formation on stainless steel and polyethylene surfaces. The result was caused by the antibacterial effect of isoeugenol, as the coating did not diminish the adhesive properties of the surface. Our study demonstrates that a simple isoeugenol coating can prevent biofilm formation of S. aureus, L. monocytogenes and P. fluorescens on two commonly used surfaces. © 2017 The Society for Applied Microbiology.

PBP-2 Negative Methicillin Resistant Staphylococcus schleiferi Bacteremia from a Prostate Abscess: An Unusual Occurrence

PubMed Central

Merchant, Chandni; Villanueva, Daphne-Dominique; Lalani, Ishan; Eng, Margaret; Kang, Yong

2016-01-01

Staphylococcus schleiferi subsp. schleiferi is a coagulase-negative Staphylococcus which has been described as a pathogen responsible for various nosocomial infections including bacteremia, brain abscess, and infection of intravenous pacemakers. Recently, such bacteria have been described to be found typically on skin and mucosal surfaces. It is also believed to be a part of the preaxillary human flora and more frequently found in men. It is very similar in its pathogenicity with Staphylococcus aureus group and expresses a fibronectin binding protein. Literature on this pathogen reveals that it commonly causes otitis among dogs because of its location in the auditory meatus of canines. Also, it has strong association with pyoderma in dogs. The prime concern with this organism is the antibiotic resistance and relapse even after appropriate treatment. Very rarely, if any, cases have been reported about prostatic abscess (PA) with this microbe. Our patient had a history of recurrent UTIs and subsequent PA resulting in S. schleiferi bacteremia in contrast to gram negative bacteremia commonly associated with UTI. This organism was found to be resistant to methicillin, in spite of being negative for PBP2, which is a rare phenomenon and needs further studies. PMID:27092283

Raw Meat-Based Diets in Dogs and Cats

PubMed Central

Heikkilä, Tiina; Pernu, Noora; Kovanen, Sara; Hielm-Björkman, Anna; Kivistö, Rauni

2017-01-01

Feeding pets raw meat-based diets (RMBDs) is commonly practiced by many companion animal owners and has received increasing attention in recent years. It may be beneficial for the animals, but may also pose a health risk for both pets and their owners, as RMBDs may be contaminated by enteric pathogens—such as Campylobacter, Salmonella, and Yersinia—which are the most common zoonotic bacteria causing enteritis in humans. Little information exists on the prevalence of these pathogens in pet food, and thus one aim was to investigate the prevalence of Campylobacter, Salmonella, and Yersinia in commercial RMBDs from retail stores. Little evidence also exists on the significance of raw meat feeding on the shedding of Campylobacter, Salmonella, and enteropathogenic Yersinia in the feces of pets, and therefore, the second goal was to study the presence of these pathogens in dogs and cats fed RMBDs. Polymerase chain reaction (PCR) only sporadically detected Campylobacter, Salmonella, and enteropathogenic Yersinia in RMBDs. These pathogens were not found by culturing, indicating a low contamination level in frozen RMBDs. They were also detected in the feces of dogs and cats, but the association with feeding RMBDs to them remained unclear. PMID:29056692

Comprehensive bactericidal activity of an ethanol-based hand gel in 15 seconds.

PubMed

Kampf, Günter; Hollingsworth, Angela

2008-01-22

Some studies indicate that the commonly recommended 30 s application time for the post contamination treatment of hands may not be necessary as the same effect may be achieved with some formulations in a shorter application time such as 15 s. We evaluated the bactericidal activity of an ethanol-based hand gel (Sterillium Comfort Gel) within 15 s in a time-kill-test against 11 Gram-positive, 16 Gram-negative bacteria and 11 emerging bacterial pathogens. Each strain was evaluated in quadruplicate. The hand gel (85% ethanol, w/w) was found to reduce all 11 Gram-positive and all 16 Gram-negative bacteria by more than 5 log10 steps within 15 s, not only against the ATCC test strains but also against corresponding clinical isolates. In addition, a log10 reduction > 5 was observed against all tested emerging bacterial pathogens. The ethanol-based hand gel was found to have a broad spectrum of bactericidal activity in only 15 s which includes the most common species causing nosocomial infections and the relevant emerging pathogens. Future research will hopefully help to find out if a shorter application time for the post contamination treatment of hands provides more benefits or more risks.

Vector-borne diseases on Fire Island, New York (Fire Island National Seashore Science Synthesis Paper)

USGS Publications Warehouse

Ginsberg, H.S.

2005-01-01

This paper discusses eleven tick-borne and five mosquito-borne pathogens that are known to occur at FIlS, or could potentially occur. The potential for future occurrence, and ecological factors that influence occurrence, are assessed for each disease. Lyme disease is the most common vector-borne disease on Fire Island. The Lyme spirochete, Borrelia burgdorferi, is endemic in local tick and wildlife populations. Public education, personal precautions against tick bite, and prompt treatment of early-stage infections can help manage the risk of Lyme disease on Fire Island. The pathogens that cause Human Monocytic Ehrlichiosis and Tularemia have been isolated from ticks or wildlife on Fire Island, and conditions suggest that other tickborne diseases (including Babesiosis, Rocky Mountain Spotted Fever, and Human Granulocytic Ehrlichiosis) might also occur, but these are far less common than Lyme disease, if present. West Nile Virus (WNV) is the primary mosquito- borne human pathogen that is known to occur on Fire Island. Ecological conditions and recent epizootiological events suggest that WNV occurs in foci that can shift from year to year. Therefore, a surveillance program with appropriate responses to increasing epizootic activity can help manage the risk of WNV transmission on Fire Island.

B cell signatures of BCWD-resistant and susceptible lines of rainbow trout: a shift towards more EBF-expressing progenitors and fewer mature B cells in resistant animals

USDA-ARS?s Scientific Manuscript database

Bacterial Cold Water Disease (BCWD) is a chronic disease of rainbow trout, and is caused by the gram-negative bacterium Flavobacterium psychrophilum (Fp), a common aquaculture pathogen. The National Center for Cool and Cold Water Aquaculture has bred two genetic lines of rainbow trout: a line of Fp...

Central venous catheter-related bacteremia caused by Kocuria kristinae: case report and review of the literature.

PubMed

Dunn, Ryan; Bares, Sara; David, Michael Z

2011-08-24

Kocuria species are unusual human pathogens isolated most commonly from immunocompromised hosts, such as transplant recipients and cancer patients undergoing chemotherapy, or from patients with chronic medical conditions. A case of catheter-related bacteremia with pulmonary septic emboli in a pregnant adult female without chronic medical conditions is described. A review of other reported Kocuria infections is provided.

Fusarium oxysporum protects Douglas-fir (Pseudotsuga menziesii) seedlings from root disease caused by Fusarium commune

Treesearch

R. Kasten Dumroese; Mee-Sook Kim; Robert L. James

2012-01-01

Fusarium root disease can be a serious problem in forest and conservation nurseries in the western United States. Fusarium inoculum is commonly found in most container and bareroot nurseries on healthy and diseased seedlings, in nursery soils, and on conifer seeds. Fusarium spp. within the F. oxysporum species complex have been recognized as pathogens for more than a...

Modeling the inactivatin of Escherichia coli 0157:H7 and uropathogenic E. coli in ground beef by high pressure processing and citral

USDA-ARS?s Scientific Manuscript database

Disease causing Escherichia coli commonly found in meat and poultry include intestinal pathogenic E. coli (iPEC) as well as extraintestinal types such as the Uropathogenic E. coli (UPEC). In this study we compared the resistance of iPEC (O157:H7) to UPEC in ground beef using High Pressure Processing...

Leptographium tereforme, sp. nov. and other Ophiostomatales isolated from the redhaired pine bark beetle, Hylurgus ligniperda, in California

Treesearch

S. Kim; T.C. Harrington; J. C. Lee; S. J. Seybold

2011-01-01

The redhaired pine bark beetle Hylurgus ligniperda (F.) is native to Europe but was discovered in Los Angeles, California, in 2003. This root- and stump-feeding beetle is a common vector of Ophiostomatales, which are potential tree pathogens or causes of blue stain of conifer sapwood. In this study Ophiostomatales were isolated on a...

Modeling the inactivation of Escherichia coli 0157:H7 and uropathogenic E.coli in ground chicken by high pressure processing and thymol

USDA-ARS?s Scientific Manuscript database

Disease causing Escherichia coli commonly found in meat and poultry include intestinal pathogenic E. coli (iPEC) as well as extraintestinal types such as the Uropathogenic E. coli (UPEC). In this study we compare the resistance of iPEC (O157:H7) to UPEC in chicken meat using High Pressure Processing...

Genome sequence of Lactobacillus salivarius SMXD51, a potential probiotic strain isolated from chicken cecum, showing anti-campylobacter activity.

PubMed

Kergourlay, Gilles; Messaoudi, Soumaya; Dousset, Xavier; Prévost, Hervé

2012-06-01

We report the draft genome sequence of Lactobacillus salivarius SMXD51, isolated from the cecum of healthy chickens showing an activity against Campylobacter--the food-borne pathogen that is the most common cause of gastroenteritis in the European Union (EU)--and potentially interesting features for a probiotic strain, explaining our interest in it.

The insulin-like growth factor pathway is altered in Spinocerebellar ataxia type 1 and type 7

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

Gatchel, Jennifer R.; Watase, Kei; Thaller, Christina

2008-01-29

Polyglutamine diseases are inherited neurodegenerative disorders caused by expansion of CAG trinucleotide repeats encoding a polyglutamine tract in the disease-causing proteins. There are nine of these disorders each having distinct features but also clinical and pathological similarities. In particular, spinocerebellar ataxia type 1 and 7 (SCA1 and SCA7) patients manifest cerebellar ataxia with corresponding degeneration of Purkinje cells. Given this common phenotype, we asked whether the two disorders share common molecular pathogenic events. To address this question we studied two genetically accurate mouse models of SCA1 and SCA7—Sca1154Q/2Q and Sca7266Q/5Q knock-in mice—that express the glutamine-expanded proteins from the respective endogenousmore » loci. We found common transcriptional changes in early symptomatic mice, with downregulation of Insulin-like growth factor binding protein 5 (Igfbp5) representing one of the most robust transcriptional changes that closely correlates with disease state. Interestingly, down-regulation of Igfbp5 occurred in granule neurons through a non-cell autonomous mechanism and was concomitant with activation of the Insulin-like growth factor I (Igf-I) pathway, and, in particular, the Igf-I receptor, expressed in part on Purkinje cells (PC). These data define a possible common pathogenic response in SCA1 and SCA7 and reveal the importance of neuron-neuron interactions in SCA1 and SCA7 pathogenesis. The sensitivity of Igfbp5 levels to disease state could render it and other components of its effector pathway useful as biomarkers in this class of diseases.« less

Modeling Fate and Transport of Rotavirus in Surface Flow by Integrating WEPP and a Pathogen Transport Model

NASA Astrophysics Data System (ADS)

Bhattarai, R.; Kalita, P. K.; Davidson, P. C.; Kuhlenschmidt, M. S.

2012-12-01

More than 3.5 million people die each year from a water related diseases in this world. Every 20 seconds, a child dies from a water-related illness. Even in a developed country like the United States, there have been at least 1870 outbreaks associated with drinking water during the period of 1920 to 2002, causing 883,806 illnesses. Most of these outbreaks are resulted due to the presence of microbial pathogens in drinking water. Rotavirus infection has been recognized as the most common cause of diarrhea in young children throughout the world. Laboratory experiments conducted at the University of Illinois have demonstrated that recovery of rotavirus has been significantly affected by climatic and soil-surface conditions like slope, soil types, and ground cover. The objective of this study is to simulate the fate and transport of Rotavirus in overland and near-surface flow using a process-based model. In order to capture the dynamics of sediment-bound pathogens, the Water Erosion Prediction Project (WEPP) is coupled with the pathogen transport model. Transport of pathogens in overland flow can be simulated mathematically by including terms for the concentration of the pathogens in the liquid phase (in suspension or free-floating) and the solid phase (adsorbed to the fine solid particles like clay and silt). Advection, adsorption, and decay processes are considered. The mass balance equations are solved using numerical technique to predict spatial and temporal changes in pathogen concentrations in two phases. Outputs from WEPP simulations (flow velocity, depth, saturated conductivity and the soil particle fraction exiting in flow) are transferred as input for the pathogen transport model. Three soil types and three different surface cover conditions have been used in the experimental investigations. Results from these conditions have been used in calibrating and validating the simulation results. Bare surface conditions have produced very good agreement between observed and predicted results; however, transport of pathogens from vegetated surface has been challenging. This paper will provide concepts of the pathogen transport model, integration with WEPP, and results obtained from the modeling framework.

Animal Models of Ebolavirus Infection

PubMed Central

Claire, Marisa C St; Ragland, Dan R; Bollinger, Laura; Jahrling, Peter B

2017-01-01

Ebola virus is a highly pathogenic member of the family Filoviridae that causes a severe hemorrhagic disease in humans and NHP. The 2013–2016 West African outbreak has increased interest in the development and refinement of animal models of Ebola virus disease. These models are used to test countermeasures and vaccines, gain scientific insights into the mechanisms of disease progression and transmission, and study key correlates of immunology. Ebola virus is classified as a BSL4 pathogen and Category A agent, for which the United States government requires preparedness in case of bioterrorism. Rodents, such as Syrian golden hamsters (Mesocricetus auratus), mice (Mus musculus), and guinea pigs (Cavia porcellus), are the most common research species. However, NHP, especially macaques, are favored for Ebola virus disease research due to similarities with humans regarding the pathogenesis, clinical presentation, laboratory findings, and causes of fatality. To satisfy the regulatory requirements for approval of countermeasures against high-consequence pathogens, the FDA instituted the Animal Rule, which permits efficacy studies in animal models in place of human clinical data when such studies are not feasible or ethical. This review provides a comprehensive summary of various animal models and their use in Ebola virus disease research. PMID:28662754

Cryptococcal pathogenic mechanisms: a dangerous trip from the environment to the brain.

PubMed

Esher, Shannon K; Zaragoza, Oscar; Alspaugh, James Andrew

2018-01-01

Cryptococcus neoformans is an opportunistic pathogenic yeast that causes serious infections, most commonly of the central nervous system (CNS). C. neoformans is mainly found in the environment and acquired by inhalation. It could be metaphorically imagined that cryptococcal disease is a "journey" for the microorganism that starts in the environment, where this yeast loads its suitcase with virulence traits. C. neoformans first encounters the infected mammalian host in the lungs, a site in which it must choose the right elements from its "virulence suitcase" to survive the pulmonary immune response. However, the lung is often only the first stop in this journey, and in some individuals the fungal trip continues to the brain. To enter the brain, C. neoformans must "open" the main barrier that protects this organ, the blood brain barrier (BBB). Once in the brain, C. neoformans expresses a distinct set of protective attributes that confers a strong neurotropism and the ability to cause brain colonisation. In summary, C. neoformans is a unique fungal pathogen as shown in its ability to survive in the face of multiple stress factors and to express virulence factors that contribute to the development of disease.

Pathogenic bacteria carried by companion animals and their susceptibility to antibacterial agents.

PubMed

Buma, Ryoko; Maeda, Takuya; Kamei, Masaharu; Kourai, Hiroki

2006-03-01

Results of the investigation showed that there was a difference in the bacteria isolated from dogs, cats and their living environment. The number and species isolated from the hair and front paw samples from dogs kept outdoors and from cats were greater and more varied than those from the samples from dogs kept indoors. Staphylococcus, Micrococcus and Bacillus were frequently detected from skin surfaces. On the other hand, Escherichia, Pseudomonas, Proteus and others were detected on each sampling area on dogs kept outdoors and on cats. About 60% of the bacteria commonly causes infectious diseases and carries a risk of food poisoning. Moreover, Pasteurella multocida, which causes pasteurellasis, a kind of zoonosis, was isolated from dogs and cats. These pathogenic bacteria were transmitted from animals to humans by direct contact. This result suggests that direct contact with dogs and cats and contact with aerosols can possibly transmit infectious diseases. Most of the isolates (75.9%, 60/79) were resistant to antibacterial agents. We then investigated the effect of household detergents and pet care deodorant sprays containing antibacterial agents on isolates from dogs and cats. They were effective in preventing the transmission of pathogens from dogs and cats to humans.

Cryptococcal pathogenic mechanisms: a dangerous trip from the environment to the brain

PubMed Central

Esher, Shannon K; Zaragoza, Oscar; Alspaugh, James Andrew

2018-01-01

Cryptococcus neoformans is an opportunistic pathogenic yeast that causes serious infections, most commonly of the central nervous system (CNS). C. neoformans is mainly found in the environment and acquired by inhalation. It could be metaphorically imagined that cryptococcal disease is a “journey” for the microorganism that starts in the environment, where this yeast loads its suitcase with virulence traits. C. neoformans first encounters the infected mammalian host in the lungs, a site in which it must choose the right elements from its “virulence suitcase” to survive the pulmonary immune response. However, the lung is often only the first stop in this journey, and in some individuals the fungal trip continues to the brain. To enter the brain, C. neoformans must “open” the main barrier that protects this organ, the blood brain barrier (BBB). Once in the brain, C. neoformans expresses a distinct set of protective attributes that confers a strong neurotropism and the ability to cause brain colonisation. In summary, C. neoformans is a unique fungal pathogen as shown in its ability to survive in the face of multiple stress factors and to express virulence factors that contribute to the development of disease. PMID:29668825

Serratia marcescens is injurious to intestinal epithelial cells

PubMed Central

Ochieng, John B; Boisen, Nadia; Lindsay, Brianna; Santiago, Araceli; Ouma, Collins; Ombok, Maurice; Fields, Barry; Stine, O Colin; Nataro, James P

2014-01-01

Diarrhea causes substantial morbidity and mortality in children in low-income countries. Although numerous pathogens cause diarrhea, the etiology of many episodes remains unknown. Serratia marcescens is incriminated in hospital-associated infections, and HIV/AIDS associated diarrhea. We have recently found that Serratia spp. may be found more commonly in the stools of patients with diarrhea than in asymptomatic control children. We therefore investigated the possible enteric pathogenicity of S. marcescens in vitro employing a polarized human colonic epithelial cell (T84) monolayer. Infected monolayers were assayed for bacterial invasion, transepithelial electrical resistance (TEER), cytotoxicity, interleukin-8 (IL-8) release and morphological changes by scanning electron microscopy. We observed significantly greater epithelial cell invasion by S. marcescens compared to Escherichia coli strain HS (p = 0.0038 respectively). Cell invasion was accompanied by reduction in TEER and secretion of IL-8. Lactate dehydrogenase (LDH) extracellular concentration rapidly increased within a few hours of exposure of the monolayer to S. marcescens. Scanning electron microscopy of S. marcescens-infected monolayers demonstrated destruction of microvilli and vacuolization. Our results suggest that S. marcescens interacts with intestinal epithelial cells in culture and induces dramatic alterations similar to those produced by known enteric pathogens. PMID:25426769

Serratia marcescens is injurious to intestinal epithelial cells.

PubMed

Ochieng, John B; Boisen, Nadia; Lindsay, Brianna; Santiago, Araceli; Ouma, Collins; Ombok, Maurice; Fields, Barry; Stine, O Colin; Nataro, James P

2014-01-01

Diarrhea causes substantial morbidity and mortality in children in low-income countries. Although numerous pathogens cause diarrhea, the etiology of many episodes remains unknown. Serratia marcescens is incriminated in hospital-associated infections, and HIV/AIDS associated diarrhea. We have recently found that Serratia spp. may be found more commonly in the stools of patients with diarrhea than in asymptomatic control children. We therefore investigated the possible enteric pathogenicity of S. marcescens in vitro employing a polarized human colonic epithelial cell (T84) monolayer. Infected monolayers were assayed for bacterial invasion, transepithelial electrical resistance (TEER), cytotoxicity, interleukin-8 (IL-8) release and morphological changes by scanning electron microscopy. We observed significantly greater epithelial cell invasion by S. marcescens compared to Escherichia coli strain HS (p = 0.0038 respectively). Cell invasion was accompanied by reduction in TEER and secretion of IL-8. Lactate dehydrogenase (LDH) extracellular concentration rapidly increased within a few hours of exposure of the monolayer to S. marcescens. Scanning electron microscopy of S. marcescens-infected monolayers demonstrated destruction of microvilli and vacuolization. Our results suggest that S. marcescens interacts with intestinal epithelial cells in culture and induces dramatic alterations similar to those produced by known enteric pathogens.

Expression of an Engineered Heterologous Antimicrobial Peptide in Potato Alters Plant Development and Mitigates Normal Abiotic and Biotic Responses

PubMed Central

Goyal, Ravinder K.; Hancock, Robert E. W.; Mattoo, Autar K.; Misra, Santosh

2013-01-01

Antimicrobial cationic peptides (AMPs) are ubiquitous small proteins used by living cells to defend against a wide spectrum of pathogens. Their amphipathic property helps their interaction with negatively charged cellular membrane of the pathogen causing cell lysis and death. AMPs also modulate signaling pathway(s) and cellular processes in animal models; however, little is known of cellular processes other than the pathogen-lysis phenomenon modulated by AMPs in plants. An engineered heterologous AMP, msrA3, expressed in potato was previously shown to cause resistance of the transgenic plants against selected fungal and bacterial pathogens. These lines together with the wild type were studied for growth habits, and for inducible defense responses during challenge with biotic (necrotroph Fusarium solani) and abiotic stressors (dark-induced senescence, wounding and temperature stress). msrA3-expression not only conferred protection against F. solani but also delayed development of floral buds and prolonged vegetative phase. Analysis of select gene transcript profiles showed that the transgenic potato plants were suppressed in the hypersensitive (HR) and reactive oxygen species (ROS) responses to both biotic and abiotic stressors. Also, the transgenic leaves accumulated lesser amounts of the defense hormone jasmonic acid upon wounding with only a slight change in salicylic acid as compared to the wild type. Thus, normal host defense responses to the pathogen and abiotic stressors were mitigated by msrA3 expression suggesting MSRA3 regulates a common step(s) of these response pathways. The stemming of the pathogen growth and mitigating stress response pathways likely contributes to resource reallocation for higher tuber yield. PMID:24147012

Recombinant Endolysins as Potential Therapeutics against Antibiotic-Resistant Staphylococcus aureus: Current Status of Research and Novel Delivery Strategies.

PubMed

Haddad Kashani, Hamed; Schmelcher, Mathias; Sabzalipoor, Hamed; Seyed Hosseini, Elahe; Moniri, Rezvan

2018-01-01

Staphylococcus aureus is one of the most common pathogens of humans and animals, where it frequently colonizes skin and mucosal membranes. It is of major clinical importance as a nosocomial pathogen and causative agent of a wide array of diseases. Multidrug-resistant strains have become increasingly prevalent and represent a leading cause of morbidity and mortality. For this reason, novel strategies to combat multidrug-resistant pathogens are urgently needed. Bacteriophage-derived enzymes, so-called endolysins, and other peptidoglycan hydrolases with the ability to disrupt cell walls represent possible alternatives to conventional antibiotics. These lytic enzymes confer a high degree of host specificity and could potentially replace or be utilized in combination with antibiotics, with the aim to specifically treat infections caused by Gram-positive drug-resistant bacterial pathogens such as methicillin-resistant S. aureus . LysK is one of the best-characterized endolysins with activity against multiple staphylococcal species. Various approaches to further enhance the antibacterial efficacy and applicability of endolysins have been demonstrated. These approaches include the construction of recombinant endolysin derivatives and the development of novel delivery strategies for various applications, such as the production of endolysins in lactic acid bacteria and their conjugation to nanoparticles. These novel strategies are a major focus of this review. Copyright © 2017 American Society for Microbiology.

Rice-Infecting Pseudomonas Genomes Are Highly Accessorized and Harbor Multiple Putative Virulence Mechanisms to Cause Sheath Brown Rot.

PubMed

Quibod, Ian Lorenzo; Grande, Genelou; Oreiro, Eula Gems; Borja, Frances Nikki; Dossa, Gerbert Sylvestre; Mauleon, Ramil; Cruz, Casiana Vera; Oliva, Ricardo

2015-01-01

Sheath rot complex and seed discoloration in rice involve a number of pathogenic bacteria that cannot be associated with distinctive symptoms. These pathogens can easily travel on asymptomatic seeds and therefore represent a threat to rice cropping systems. Among the rice-infecting Pseudomonas, P. fuscovaginae has been associated with sheath brown rot disease in several rice growing areas around the world. The appearance of a similar Pseudomonas population, which here we named P. fuscovaginae-like, represents a perfect opportunity to understand common genomic features that can explain the infection mechanism in rice. We showed that the novel population is indeed closely related to P. fuscovaginae. A comparative genomics approach on eight rice-infecting Pseudomonas revealed heterogeneous genomes and a high number of strain-specific genes. The genomes of P. fuscovaginae-like harbor four secretion systems (Type I, II, III, and VI) and other important pathogenicity machinery that could probably facilitate rice colonization. We identified 123 core secreted proteins, most of which have strong signatures of positive selection suggesting functional adaptation. Transcript accumulation of putative pathogenicity-related genes during rice colonization revealed a concerted virulence mechanism. The study suggests that rice-infecting Pseudomonas causing sheath brown rot are intrinsically diverse and maintain a variable set of metabolic capabilities as a potential strategy to occupy a range of environments.

Inactivation of DNA mismatch repair by variants of uncertain significance in the PMS2 gene.

PubMed

Drost, Mark; Koppejan, Hester; de Wind, Niels

2013-11-01

Lynch syndrome (LS) is a common cancer predisposition caused by an inactivating mutation in one of four DNA mismatch repair (MMR) genes. Frequently a variant of uncertain significance (VUS), rather than an obviously pathogenic mutation, is identified in one of these genes. The inability to define pathogenicity of such variants precludes targeted healthcare. Here, we have modified a cell-free assay to test VUS in the MMR gene PMS2 for functional activity. We have analyzed nearly all VUS in PMS2 found thus far and describe loss of MMR activity for five, suggesting the applicability of the assay for diagnosis of LS. © 2013 WILEY PERIODICALS, INC.

Evolution of pathogenicity and sexual reproduction in eight Candida genomes

PubMed Central

Butler, Geraldine; Rasmussen, Matthew D.; Lin, Michael F.; Santos, Manuel A.S.; Sakthikumar, Sharadha; Munro, Carol A.; Rheinbay, Esther; Grabherr, Manfred; Forche, Anja; Reedy, Jennifer L.; Agrafioti, Ino; Arnaud, Martha B.; Bates, Steven; Brown, Alistair J.P.; Brunke, Sascha; Costanzo, Maria C.; Fitzpatrick, David A.; de Groot, Piet W. J.; Harris, David; Hoyer, Lois L.; Hube, Bernhard; Klis, Frans M.; Kodira, Chinnappa; Lennard, Nicola; Logue, Mary E.; Martin, Ronny; Neiman, Aaron M.; Nikolaou, Elissavet; Quail, Michael A.; Quinn, Janet; Santos, Maria C.; Schmitzberger, Florian F.; Sherlock, Gavin; Shah, Prachi; Silverstein, Kevin; Skrzypek, Marek S.; Soll, David; Staggs, Rodney; Stansfield, Ian; Stumpf, Michael P H; Sudbery, Peter E.; Thyagarajan, Srikantha; Zeng, Qiandong; Berman, Judith; Berriman, Matthew; Heitman, Joseph; Gow, Neil A. R.; Lorenz, Michael C.; Birren, Bruce W.; Kellis, Manolis; Cuomo, Christina A.

2009-01-01

Candida species are the most common cause of opportunistic fungal infection worldwide. We report the genome sequences of six Candida species and compare these and related pathogens and nonpathogens. There are significant expansions of cell wall, secreted, and transporter gene families in pathogenic species, suggesting adaptations associated with virulence. Large genomic tracts are homozygous in three diploid species, possibly resulting from recent recombination events. Surprisingly, key components of the mating and meiosis pathways are missing from several species. These include major differences at the Mating-type loci (MTL); Lodderomyces elongisporus lacks MTL, and components of the a1/alpha2 cell identity determinant were lost in other species, raising questions about how mating and cell types are controlled. Analysis of the CUG leucine to serine genetic code change reveals that 99% of ancestral CUG codons were erased and new ones arose elsewhere. Lastly, we revise the C. albicans gene catalog, identifying many new genes. PMID:19465905

Antibiotic-non-antibiotic combinations for combating extremely drug-resistant Gram-negative 'superbugs'.

PubMed

Schneider, Elena K; Reyes-Ortega, Felisa; Velkov, Tony; Li, Jian

2017-02-28

The emergence of antimicrobial resistance of Gram-negative pathogens has become a worldwide crisis. The status quo for combating resistance is to employ synergistic combinations of antibiotics. Faced with this fast-approaching post-antibiotic era, it is critical that we devise strategies to prolong and maximize the clinical efficacy of existing antibiotics. Unfortunately, reports of extremely drug-resistant (XDR) Gram-negative pathogens have become more common. Combining antibiotics such as polymyxin B or the broad-spectrum tetracycline and minocycline with various FDA-approved non-antibiotic drugs have emerged as a novel combination strategy against otherwise untreatable XDR pathogens. This review surveys the available literature on the potential benefits of employing antibiotic-non-antibiotic drug combination therapy. The apex of this review highlights the clinical utility of this novel therapeutic strategy for combating infections caused by 'superbugs'. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Confronting inconsistencies in the amphibian-chytridiomycosis system: implications for disease management.

PubMed

Venesky, Matthew D; Raffel, Thomas R; McMahon, Taegan A; Rohr, Jason R

2014-05-01

Chytridiomycosis, caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd), is one of the largest threats to wildlife and is putatively linked to the extirpation of numerous amphibians. Despite over a decade of research on Bd, conflicting results from a number of studies make it difficult to forecast where future epizootics will occur and how to manage this pathogen effectively. Here, we emphasize how resolving these conflicts will advance Bd management and amphibian conservation efforts. We synthesize current knowledge on whether Bd is novel or endemic, whether amphibians exhibit acquired resistance to Bd, the importance of host resistance versus tolerance to Bd, and how biotic (e.g. species richness) and abiotic factors (e.g. climate change) affect Bd abundance. Advances in our knowledge of amphibian-chytrid interactions might inform the management of fungal pathogens in general, which are becoming more common and problematic globally. © 2013 The Authors. Biological Reviews © 2013 Cambridge Philosophical Society.

Risk factors for community-acquired bacterial meningitis.

PubMed

Lundbo, Lene Fogt; Benfield, Thomas

2017-06-01

Bacterial meningitis is a significant burden of disease and mortality in all age groups worldwide despite the development of effective conjugated vaccines. The pathogenesis of bacterial meningitis is based on complex and incompletely understood host-pathogen interactions. Some of these are pathogen-specific, while some are shared between different bacteria. We searched the database PubMed to identify host risk factors for bacterial meningitis caused by the pathogens Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae type b, because they are three most common causative bacteria beyond the neonatal period. We describe a number of risk factors; including socioeconomic factors, age, genetic variation of the host and underlying medical conditions associated with increased susceptibility to invasive bacterial infections in both children and adults. As conjugated vaccines are available for these infections, it is of utmost importance to identify high risk patients to be able to prevent invasive disease.

Hymenolepis nana: a common cause of paediatric diarrhoea in urban slum dwellers in India.

PubMed

Mirdha, Bijay Ranjan; Samantray, Jyotish Chandra

2002-12-01

The prevalence of intestinal parasitic infections was studied for a period of 5 years (April 1996-April 2001) among urban slum dwellers. All age groups were represented in the study. Parasitological examinations were performed on 939 faecal specimens collected on a household basis. The total prevalence of pathogenic parasites was 33.6 per cent. No significant age and sex differences in pathogenic parasites were observed. The prevalence of intestinal helminths and pathogenic protozoa was as follows: Hymenolepis nana (9.9 per cent), Ascaris lumbricoides (8.5 per cent), Giardia lamblia (8.4 per cent) and Entamoeba histolyticaldispar (3.7 per cent). Thirty-four E. histolytica/dispar positive samples were cultured and speciation was done using polymerase chain reaction (PCR). The predominant isolate was E. dispar compared to E. histolytica. The notable finding of the present study was high prevalence of Hymenolepis nana compared with other parasitic infections in slum dwellers.

Pasteurella multocida non-native joint infection after a dog lick: A case report describing a complicated two-stage revision and a comprehensive review of the literature

PubMed Central

Philip W, Lam; Page, Andrea V

2015-01-01

Prosthetic joint infections (PJIs) are commonly caused by pathogens such as Staphylococcus aureus and coagulase-negative staphylococci; however, other microbial etiologies and specific risk factors are increasingly recognized. Pasteurella multocida is a Gram-negative coccobacillus that is part of the normal oral flora in many animals, and is particularly common in dogs and cats. PJIs caused by P multocida have been reported only rarely in the literature and typically occur in the context of an animal bite or scratch. The present article describes a P multocida joint infection that occurred after a dog lick and complicated a two-stage revision arthroplasty. A comprehensive review of the literature regarding P multocida PJIs follows. PMID:26361490

Septic Pulmonary Embolism Requiring Critical Care: Clinicoradiological Spectrum, Causative Pathogens and Outcomes

PubMed Central

Chou, Deng-Wei; Wu, Shu-Ling; Chung, Kuo-Mou; Han, Shu-Chen; Cheung, Bruno Man-Hon

2016-01-01

OBJECTIVES: Septic pulmonary embolism is an uncommon but life-threatening disorder. However, data on patients with septic pulmonary embolism who require critical care have not been well reported. This study elucidated the clinicoradiological spectrum, causative pathogens and outcomes of septic pulmonary embolism in patients requiring critical care. METHODS: The electronic medical records of 20 patients with septic pulmonary embolism who required intensive care unit admission between January 2005 and December 2013 were reviewed. RESULTS: Multiple organ dysfunction syndrome developed in 85% of the patients, and acute respiratory failure was the most common organ failure (75%). The most common computed tomographic findings included a feeding vessel sign (90%), peripheral nodules without cavities (80%) or with cavities (65%), and peripheral wedge-shaped opacities (75%). The most common primary source of infection was liver abscess (40%), followed by pneumonia (25%). The two most frequent causative pathogens were Klebsiella pneumoniae (50%) and Staphylococcus aureus (35%). Compared with survivors, nonsurvivors had significantly higher serum creatinine, arterial partial pressure of carbon dioxide, and Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores, and they were significantly more likely to have acute kidney injury, disseminated intravascular coagulation and lung abscesses. The in-hospital mortality rate was 30%. Pneumonia was the most common cause of death, followed by liver abscess. CONCLUSIONS: Patients with septic pulmonary embolism who require critical care, especially those with pneumonia and liver abscess, are associated with high mortality. Early diagnosis, appropriate antibiotic therapy, surgical intervention and respiratory support are essential. PMID:27759843

Clinical Manifestations, Hematology, and Chemistry Profiles of the Six Most Common Etiologies from an Observational Study of Acute Febrile Illness in Indonesia

PubMed Central

Kosasih, Herman; Karyana, Muhammad; Lokida, Dewi; Alisjahbana, Bachti; Tjitra, Emiliana; Gasem, Muhammad Hussein; Aman, Abu Tholib; Merati, Ketut Tuti; Arif, Mansyur; Sudarmono, Pratiwi; Suharto, Suharto; Lisdawati, Vivi; Neal, Aaron; Siddiqui, Sophia

2017-01-01

Abstract Background Infectious diseases remain a significant healthcare burden in the developing world. In Indonesia, clinicians often manage and treat patients solely based on clinical presentations since the diagnostic testing capacities of hospitals are limited. Unfortunately, the most common infections in this tropical environment share highly similar manifestations, complicating the identification of etiologies and leading to the misdiagnosis of illness. When pathogen-specific testing is available, generally at top-tier specialist hospitals, the limited range of tests and slow turnaround times may never lead to a definitive diagnosis or improved patient outcomes. Methods To identify clinical parameters that can be used for differentiating the most common causes of fever in Indonesia, we evaluated clinical data from 1,486 acute febrile patients enrolled in a multi-site observational cohort study during 2013 to 2016. Results From the 66% of subjects with confirmed etiologies, the six most common infections were dengue virus (455), Salmonella spp. (124), Rickettsia spp. (109), influenza virus (64), Leptospira spp. (53), and chikungunya virus (37). The accompanying figure shows the clinical signs and symptoms (A) and hematology and blood chemistry results (B) for the color-coded pathogens. Comparing the profiles of all infected subjects reveals parameters that are uniquely associated with particular pathogens, such as leukopenia with dengue virus. Conclusion These observations will assist clinicians in healthcare systems with limited diagnostic testing capacities and may be useful in formulating diagnostic algorithms for Indonesia and other developing countries. Disclosures All authors: No reported disclosures.

Guillian-Barre syndrome.

PubMed

Talukder, R K; Sutradhar, S R; Rahman, K M; Uddin, M J; Akhter, H

2011-10-01

Guillian-Barre syndrome (GBS) is the most common cause of acute flaccid paralysis. All age groups can be affected, more common in elderly. Campylobacter jejuni, a major cause of bacterial gastroenteritis worldwide has become recognized as a most frequent antecedent pathogen for GBS. A prospective case-controlled study showed, positive C. Jejuni serology was found in an unprecedented high frequency of 57% as compared to 8% in family controls and 3% in control patients with other neurological diseases. In GBS there is molecular mimicry between epitops found in the cell walls of some micro-organisms and gangliosides in schwann cell membrane. Diagnosis is mainly clinical. The mainstay of treatment of GBS is supportive care and prevention of complications. Respiratory failure and autonomic dysfunction are the common causes of death from GBS. Plasma exchange and intravenous immunoglobulin therapy shorten the duration of ventilation and improve prognosis. Overall, prognosis of GBS is good. Eighty percent of patients recover completely within 3-6 months, 4% die, and the remainder suffers residual neurological disability. GBS may be prevented by development of a vaccine against C. Jejuni. Early and specific diagnosis is important to ensure a favourable outcome.

Periodontitis-associated septic pulmonary embolism caused by Actinomyces species identified by anaerobic culture of bronchoalveolar lavage fluid: a case report.

PubMed

Endo, Shun; Mishima, Eikan; Takeuchi, Yoichi; Ohi, Takashi; Ishida, Masatsugu; Yanai, Masaru; Kiyomoto, Hideyasu; Nagasawa, Tasuku; Ito, Sadayoshi

2015-12-01

Periodontal disease is a less common but important cause of septic pulmonary embolism (SPE). However, the pathogens causing periodontal disease-associated SPE (PD-SPE) have been poorly understood. Actinomyces species are resident microbiota in the oral cavity. Here we report a case of PD-SPE caused by Actinomyces species, which was identified by anaerobic culture of bronchoalveolar lavage fluid (BAL). A 64-year-old Asian man, complicated with severe chronic periodontitis, was admitted with chest pain and fever. Chest CT revealed multiple bilateral pulmonary nodules located subpleurally. We diagnosed the case as SPE associated with periodontitis. Although blood cultures were negative for the usual 5-day incubation, anaerobic culture of the BAL fluid sample yielded Actinomyces species. Antibacterial therapy alone did not ameliorate the symptoms; however, additional dental treatment, including tooth extraction, promptly did. The patient was discharged 23 days after admission. The 3-month follow-up revealed no recurrence of the symptoms and complete resolution of the lung lesions. This case demonstrated that Actinomyces species can cause PD-SPE. Additionally, clinicians should consider performing appropriate anaerobic culture of BAL fluid to identify the pathogen of SPE, and to ordering dental treatment, if necessary, in addition to antibiotics for the initial management of PD-SPE.

Infectious diarrheal disease caused by contaminated well water in Chinese schools: A systematic review and meta-analysis.

PubMed

Ding, Zheyuan; Zhai, Yujia; Wu, Chen; Wu, Haocheng; Lu, Qinbao; Lin, Junfen; He, Fan

2017-06-01

In China, waterborne outbreaks of infectious diarrheal disease mainly occur in schools, and contaminated well water is a common source of pathogens. The objective of this review was to present the attack rates, durations of outbreak, pathogens of infectious diarrheal disease, and sanitary conditions of wells in primary and secondary schools in China, and to analyze risk factors and susceptibility of school children. Relevant articles and reports were identified by searching PubMed, Web of Science, China National Knowledge Infrastructure, China Information System for Disease Control and Prevention, and the Chinese Field Epidemiology Training Program. Essential information, including urban/rural areas, school types, attack rates, pathogens, durations of outbreak, report intervals, and interventions were extracted from the eligible articles. Wilcoxon signed-rank test, Kruskal-Wallis H test, and Spearman correlation test were conducted in statistical analyses. Sex- and age-specific attack rate ratios were calculated as pooled effect sizes. We screened 2188 articles and retrieved data of 85 outbreaks from 1987 to 2014. Attack rates of outbreaks in rural areas (median, 12.63 cases/100 persons) and in primary schools (median, 14.54 cases/100 persons) were higher than those in urban areas (median, 5.62 cases/100 persons) and in secondary schools (median, 8.74 cases/100 persons) (P = 0.004 and P = 0.013, respectively). Shigella, pathogenic Escherichia coli, and norovirus were the most common pathogens. Boys tended toward higher attack rates than girls (sex-specific attack rate ratio, 1.13; 95% CI, 1.00-1.29, P = 0.05). Unsanitary conditions of water wells were reported frequently, and unhealthy behavior habits were common in students. School children were susceptible to waterborne disease in China. Chinese government should make efforts to improve access to safe water in schools. Health education promotion and conscientiousness of school leaders and teachers should be enhanced. Copyright © 2017. Production and hosting by Elsevier B.V.

Germline MLH1, MSH2 and MSH6 variants in Brazilian patients with colorectal cancer and clinical features suggestive of Lynch Syndrome.

PubMed

Schneider, Nayê Balzan; Pastor, Tatiane; Paula, André Escremim de; Achatz, Maria Isabel; Santos, Ândrea Ribeiro Dos; Vianna, Fernanda Sales Luiz; Rosset, Clévia; Pinheiro, Manuela; Ashton-Prolla, Patricia; Moreira, Miguel Ângelo Martins; Palmero, Edenir Inêz

2018-05-01

Lynch syndrome (LS) is the most common hereditary colorectal cancer syndrome, caused by germline mutations in one of the major genes involved in mismatch repair (MMR): MLH1, MSH2, MSH6 and more rarely, PMS2. Recently, germline deletions in EPCAM have been also associated to the syndrome. Most of the pathogenic MMR mutations found in LS families occur in MLH1 or MSH2. Gene variants include missense, nonsense, frameshift mutations, large genomic rearrangements and splice-site variants and most of the studies reporting the molecular characterization of LS families have been conducted outside South America. In this study, we analyzed 60 unrelated probands diagnosed with colorectal cancer and LS criteria. Testing for germline mutations and/or rearrangements in the most commonly affected MMR genes (MLH1, MSH2, EPCAM and MSH6) was done by Sanger sequencing and MLPA. Pathogenic or likely pathogenic variants were identified in MLH1 or MSH2 in 21 probands (35.0%). Of these, approximately one-third were gene rearrangements. In addition, nine variants of uncertain significance (VUS) were identified in 10 (16.6%) of the sixty probands analyzed. Other four novel variants were identified, only in MLH1. Our results suggest that MSH6 pathogenic variants are not common among Brazilian LS probands diagnosed with CRC and that MMR gene rearrangements account for a significant proportion of the germline variants in this population underscoring the need to include rearrangement analysis in the molecular testing of Brazilian individuals with suspected Lynch syndrome. © 2018 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Plesiomonas shigelloides Periprosthetic Knee Infection After Consumption of Raw Oysters.

PubMed

Hustedt, Joshua W; Ahmed, Sarim

Periprosthetic infections are a leading cause of morbidity after total joint arthroplasty. Common pathogens include Staphylococcus aureus, streptococcus, enterococcus, Escherichia coli, and Pseudomonas aeruginosa. However, there are many cases in which rare bacteria are isolated. This case report describes a periprosthetic knee infection caused by Plesiomonas shigelloides. In the United States, P shigelloides and 2 other Vibrionaceae family members, Vibrio vulnificus and Vibrio parahaemolyticus, are most often contracted from eating raw oysters and shellfish. P shigelloides usually causes a self-limiting watery diarrhea, but in immunosuppressed people it can cause septicemia. In this case report, a chemically and biologically immunosuppressed man consumed raw oysters and developed P shigelloides septicemia and acute periprosthetic knee infection that required surgical intervention.

Pathogenic Streptomyces spp. abundance affected by potato cultivars.

PubMed

Nahar, Kamrun; Goyer, Claudia; Zebarth, Bernie J; Burton, David L; Whitney, Sean

2018-04-16

Potato cultivars vary in their tolerance to common scab (CS), however how they affect CS-causing Streptomyces spp. populations over time is poorly understood. This study investigated the effects of potato cultivar on pathogenic Streptomyces spp. abundance, measured using quantitative PCR, in three spatial locations in a CS-infested field: 1) soil close to the plant (SCP); 2) rhizosphere (RS); and 3) geocaulosphere (GS) soils. Two tolerant (Gold Rush, Hindenburg) and two susceptible cultivars (Green Mountain, Agria) were tested. The abundance of pathogenic Streptomyces spp. significantly increased in late August compared with other dates in RS of susceptible cultivars in both years. Abundance of pathogenic Streptomyces spp., when averaged over locations and time, was significantly greater in susceptible cultivars compared with tolerant cultivars in 2014. Principal coordinates analysis showed that SCP and RS soil properties (pH, organic carbon and nitrogen concentrations) explained 68% and 76% of total variation in Streptomyces spp. abundance among cultivars in 2013, respectively, suggesting that cultivars influenced CS pathogen growth conditions. The results suggested that the genetic background of potato cultivars influenced the abundance of pathogenic Streptomyces spp., with 5 to 6 times more abundant Streptomyces spp. in RS of susceptible cultivars compared with tolerant cultivars, which would result in substantially more inoculum left in the field after harvest.  .

Aspergillus flavus: human pathogen, allergen and mycotoxin producer.

PubMed

Hedayati, M T; Pasqualotto, A C; Warn, P A; Bowyer, P; Denning, D W

2007-06-01

Aspergillus infections have grown in importance in the last years. However, most of the studies have focused on Aspergillus fumigatus, the most prevalent species in the genus. In certain locales and hospitals, Aspergillus flavus is more common in air than A. fumigatus, for unclear reasons. After A. fumigatus, A. flavus is the second leading cause of invasive aspergillosis and it is the most common cause of superficial infection. Experimental invasive infections in mice show A. flavus to be 100-fold more virulent than A. fumigatus in terms of inoculum required. Particularly common clinical syndromes associated with A. flavus include chronic granulomatous sinusitis, keratitis, cutaneous aspergillosis, wound infections and osteomyelitis following trauma and inoculation. Outbreaks associated with A. flavus appear to be associated with single or closely related strains, in contrast to those associated with A. fumigatus. In addition, A. flavus produces aflatoxins, the most toxic and potent hepatocarcinogenic natural compounds ever characterized. Accurate species identification within Aspergillus flavus complex remains difficult due to overlapping morphological and biochemical characteristics, and much taxonomic and population genetics work is necessary to better understand the species and related species. The flavus complex currently includes 23 species or varieties, including two sexual species, Petromyces alliaceus and P. albertensis. The genome of the highly related Aspergillus oryzae is completed and available; that of A. flavus in the final stages of annotation. Our understanding of A. flavus lags far behind that of A. fumigatus. Studies of the genomics, taxonomy, population genetics, pathogenicity, allergenicity and antifungal susceptibility of A. flavus are all required.

Contaminated milk is a common cause of necrotising enterocolitis: A hypothesis.

PubMed

Boo, N Y

2016-12-01

Necrotising enterocolitis (NEC) is the most commonly acquired gastrointestinal disease of neonates, particularly the very preterm (gestation <32 weeks) and/or very low birth weight (<1500g). It is associated with high morbidity and mortality. Despite improvement in neonatal care and increased use of expressed breast milk (EBM), the incidence remains high in many neonatal intensive care units (NICU), and even shows increasing trend in some countries. Numerous studies have pointed to the infective nature of NEC. Some investigators have reported an increase in the incidence of NEC in their NICU when the percentage of infants with pathogens isolated from their gut increased, and decreased when gut colonisation rate was low. Both bacteria and viruses have been reported to be associated with outbreaks of NEC. The majority (>90%) of the NEC cases occurred in neonates on enteral feeding. Studies have shown that milk (whether EBM or formula) fed to neonates was not sterile and were further contaminated during collection, transport, storage and/or feeding. Other investigators have reported a reduction in the incidence of NEC when they improved infection control measures and hygienic procedures in handling milk. It is, therefore, hypothesised that the most common cause of NEC is due to the feeding of neonates, particularly the vulnerable very preterm small neonates, with milk heavily contaminated during collection at source, transport, storage and/or feeding. Because of the immaturity of the immune system of the neonates, excessive inflammatory response to the pathogen load in the gut leads to the pathogenesis of NEC.

Fungi in healthy and diseased sea fans ( Gorgonia ventalina): is Aspergillus sydowii always the pathogen?

NASA Astrophysics Data System (ADS)

Toledo-Hernández, C.; Zuluaga-Montero, A.; Bones-González, A.; Rodríguez, J. A.; Sabat, A. M.; Bayman, P.

2008-09-01

Caribbean corals, including sea fans ( Gorgonia spp.), are being affected by severe and apparently new diseases. In the case of sea fans, the pathogen is reported to be the fungus Aspergillus sydowii, and the disease is named aspergillosis. In order to understand coral diseases and pathogens, knowledge of the microbes associated with healthy corals is also necessary. In this study the fungal community of healthy Gorgonia ventalina colonies was contrasted with that of diseased colonies. In addition, the fungal community of healthy and diseased tissue within colonies with aspergillosis was contrasted. Fungi were isolated from healthy and diseased fans from 15 reefs around Puerto Rico, and identified by sequencing the nuclear ribosomal ITS region and by morphology. Thirty fungal species belonging to 15 genera were isolated from 203 G. ventalina colonies. Penicillum and Aspergillus were the most common genera isolated from both healthy and diseased fans. However, the fungal community of healthy fans was distinct and more diverse than that of diseased ones. Within diseased fans, fungal communities from diseased tissues were distinct and more diverse than from healthy tissue. The reduction of fungi in diseased colonies may occur prior to infection due to environmental changes affecting the host, or after infection due to increase in dominance of the pathogen, or because of host responses to infection. Data also indicate that the fungal community of an entire sea fan colony is affected even when only a small portion of the colony suffers from aspergillosis. An unexpected result was that A. sydowii was found in healthy sea fans but never in diseased ones. This result suggests that A. sydowii is not the pathogen causing aspergillosis in the studied colonies, and suggests several fungi common to healthy and diseased colonies as opportunistic pathogens. Given that it is not clear that Aspergillus is the sole pathogen, calling this disease aspergillosis is an oversimplification at best.

Impact of Vector Dispersal and Host-Plant Fidelity on the Dissemination of an Emerging Plant Pathogen

PubMed Central

Johannesen, Jes; Foissac, Xavier; Kehrli, Patrik; Maixner, Michael

2012-01-01

Dissemination of vector-transmitted pathogens depend on the survival and dispersal of the vector and the vector's ability to transmit the pathogen, while the host range of vector and pathogen determine the breath of transmission possibilities. In this study, we address how the interaction between dispersal and plant fidelities of a pathogen (stolbur phytoplasma tuf-a) and its vector (Hyalesthes obsoletus: Cixiidae) affect the emergence of the pathogen. Using genetic markers, we analysed the geographic origin and range expansion of both organisms in Western Europe and, specifically, whether the pathogen's dissemination in the northern range is caused by resident vectors widening their host-plant use from field bindweed to stinging nettle, and subsequent host specialisation. We found evidence for common origins of pathogen and vector south of the European Alps. Genetic patterns in vector populations show signals of secondary range expansion in Western Europe leading to dissemination of tuf-a pathogens, which might be newly acquired and of hybrid origin. Hence, the emergence of stolbur tuf-a in the northern range was explained by secondary immigration of vectors carrying stinging nettle-specialised tuf-a, not by widening the host-plant spectrum of resident vectors with pathogen transmission from field bindweed to stinging nettle nor by primary co-migration from the resident vector's historical area of origin. The introduction of tuf-a to stinging nettle in the northern range was therefore independent of vector's host-plant specialisation but the rapid pathogen dissemination depended on the vector's host shift, whereas the general dissemination elsewhere was linked to plant specialisation of the pathogen but not of the vector. PMID:23284774

Impact of vector dispersal and host-plant fidelity on the dissemination of an emerging plant pathogen.

PubMed

Johannesen, Jes; Foissac, Xavier; Kehrli, Patrik; Maixner, Michael

2012-01-01

Dissemination of vector-transmitted pathogens depend on the survival and dispersal of the vector and the vector's ability to transmit the pathogen, while the host range of vector and pathogen determine the breath of transmission possibilities. In this study, we address how the interaction between dispersal and plant fidelities of a pathogen (stolbur phytoplasma tuf-a) and its vector (Hyalesthes obsoletus: Cixiidae) affect the emergence of the pathogen. Using genetic markers, we analysed the geographic origin and range expansion of both organisms in Western Europe and, specifically, whether the pathogen's dissemination in the northern range is caused by resident vectors widening their host-plant use from field bindweed to stinging nettle, and subsequent host specialisation. We found evidence for common origins of pathogen and vector south of the European Alps. Genetic patterns in vector populations show signals of secondary range expansion in Western Europe leading to dissemination of tuf-a pathogens, which might be newly acquired and of hybrid origin. Hence, the emergence of stolbur tuf-a in the northern range was explained by secondary immigration of vectors carrying stinging nettle-specialised tuf-a, not by widening the host-plant spectrum of resident vectors with pathogen transmission from field bindweed to stinging nettle nor by primary co-migration from the resident vector's historical area of origin. The introduction of tuf-a to stinging nettle in the northern range was therefore independent of vector's host-plant specialisation but the rapid pathogen dissemination depended on the vector's host shift, whereas the general dissemination elsewhere was linked to plant specialisation of the pathogen but not of the vector.

The enemy within: phloem-limited pathogens

USDA-ARS?s Scientific Manuscript database

The growing impact of phloem-limited pathogens on high-value crops has led to a renewed interest in understanding how they cause disease. Although these pathogens cause substantial crop losses, many are poorly characterized. In this review, we present examples of phloem-limited pathogens that includ...

Potential worldwide distribution of Fusarium dry root rot in common beans based on the optimal environment for disease occurrence

PubMed Central

Macedo, Renan; Sales, Lilian Patrícia; Yoshida, Fernanda; Silva-Abud, Lidianne Lemes

2017-01-01

Root rots are a constraint for staple food crops and a long-lasting food security problem worldwide. In common beans, yield losses originating from root damage are frequently attributed to dry root rot, a disease caused by the Fusarium solani species complex. The aim of this study was to model the current potential distribution of common bean dry root rot on a global scale and to project changes based on future expectations of climate change. Our approach used a spatial proxy of the field disease occurrence, instead of solely the pathogen distribution. We modeled the pathogen environmental requirements in locations where in-situ inoculum density seems ideal for disease manifestation. A dataset of 2,311 soil samples from commercial farms assessed from 2002 to 2015 allowed us to evaluate the environmental conditions associated with the pathogen’s optimum inoculum density for disease occurrence, using a lower threshold as a spatial proxy. We encompassed not only the optimal conditions for disease occurrence but also the optimal pathogen’s density required for host infection. An intermediate inoculum density of the pathogen was the best disease proxy, suggesting density-dependent mechanisms on host infection. We found a strong convergence on the environmental requirements of both the host and the disease development in tropical areas, mostly in Brazil, Central America, and African countries. Precipitation and temperature variables were important for explaining the disease occurrence (from 17.63% to 43.84%). Climate change will probably move the disease toward cooler regions, which in Brazil are more representative of small-scale farming, although an overall shrink in total area (from 48% to 49% in 2050 and 26% to 41% in 2070) was also predicted. Understanding pathogen distribution and disease risks in an evolutionary context will therefore support breeding for resistance programs and strategies for dry root rot management in common beans. PMID:29107985

Follow-up after infants younger than 2 months of age with urinary tract infection in Southern Israel: epidemiologic, microbiologic and disease recurrence characteristics.

PubMed

Gurevich, Evgenia; Tchernin, Dov; Schreyber, Ruth; Muller, Robert; Leibovitz, Eugene

2016-01-01

The timing of most recurrences after neonatal urinary tract infection is during the first year of life, with peak incidence 2-6 months after the initial infection. Information on the microbiologic characteristics of recurrent urinary tract infection episodes in relation to the microbiology of the initial episodes is limited. To analyze the epidemiologic/microbiological characteristics of 1st and recurrent urinary tract infection in infants <2 months of age. A retrospective study including all infants <2 months of age with urinary tract infection admitted during 2005-2009 and followed till the age of 1 year. 151 neonates were enrolled (2.7% of all 5617 febrile infants <2 months of age admitted). The overall incidence of urinary tract infection occurring during the first 2 months of life was 151/73,480 (0.2%) live births during 2005-2009 in southern Israel (2.1 cases/1000 live births). One pathogen was isolated in 133 (88.1%); Escherichia coli, Klebsiella spp., Enterococcus spp., Morganella morganii, Proteus spp., and Enterobacter spp. represented the most common pathogens (57.9%, 12.2%, 7.9%, 6.7%, 6.1%, and 5%, respectively). Trimethoprim/sulfamethoxazole, ampicillin, and cefuroxime-axetil were the most commonly recommended prophylactic antibiotics (45%, 13.2%, and 8%, respectively). Twenty-three recurrent urinary tract infection episodes were recorded in 20 (13.2%) patients; 6/23 (26%) were diagnosed within one month following 1st episode. E. coli was the most frequent recurrent urinary tract infection pathogen (12/23, 52.2%). No differences were recorded in E. coli distribution between first urinary tract infection vs. recurrent urinary tract infection. Seventeen (74%) recurrent urinary tract infection episodes were caused by pathogens different (phenotypically) from those isolated in 1st episode. Recurrent urinary tract infection occurred in 25.0%, 8.3%, and 0 patients recommended trimethoprim/sulfamethoxazole, cefuroxime-axetil, or amoxicillin prophylaxis, respectively. (1) The study determined the incidence of urinary tract infection in febrile infants <2 months of age in Southern Israel; (2) E. coli was responsible for the majority of first and recurrent urinary tract infection; (3) recurrent urinary tract infection was caused mostly by pathogens different than the pathogens isolated at initial episode. Copyright © 2015 Elsevier Editora Ltda. All rights reserved.

Genotypic and Phenotypic Characterization of Enterotoxigenic Escherichia coli Strains Isolated from Peruvian Children

DTIC Science & Technology

2010-09-01

Organization (WHO), ETEC is the second most common cause of diarrhea after rotavirus in children less than 5 years of age and is therefore an...pathogens (Shigella, Salmonella. Vibrio, Campylo/Jacter, Gi- ardia Iamblia, Cryptosporidium, and rotavirus ) by conventional methods. Five lactose...DAEC (2% and 3%, respec- tively), Campylobacter (20% and 6%, respectively), and Shi- gella (2% and 0%, respectively). Rotavirus was found in 10% ( 4

Central venous catheter-related bacteremia caused by Kocuria kristinae: Case report and review of the literature

PubMed Central

2011-01-01

Kocuria species are unusual human pathogens isolated most commonly from immunocompromised hosts, such as transplant recipients and cancer patients undergoing chemotherapy, or from patients with chronic medical conditions. A case of catheter-related bacteremia with pulmonary septic emboli in a pregnant adult female without chronic medical conditions is described. A review of other reported Kocuria infections is provided. PMID:21864336

Interplay between Candida albicans and the Mammalian Innate Host Defense

PubMed Central

Cheng, Shih-Chin; Joosten, Leo A. B.; Kullberg, Bart-Jan

2012-01-01

Candida albicans is both the most common fungal commensal microorganism in healthy individuals and the major fungal pathogen causing high mortality in at-risk populations, especially immunocompromised patients. In this review, we summarize the interplay between the host innate system and C. albicans, ranging from how the host recognizes, responds, and clears C. albicans infection to how C. albicans evades, dampens, and escapes from host innate immunity. PMID:22252867

Looking into Candida albicans infection, host response, and antifungal strategies.

PubMed

Wang, Yan

2015-01-01

Candida albicans, a commonly encountered fungal pathogen, causes diseases varying from superficial mucosal complaints to life-threatening systemic disorders. Among the virulence traits of C. albicans, yeast-to-hypha transition is most widely acknowledged. Host innate immunity to C. albicans critically requires pattern recognition receptors (PRRs), and defence against C. albicans infection is provided by an exquisite interplay between the innate and adaptive arms of the host immune system.

Host-Pathogen Checkpoints and Population Bottlenecks in Persistent and Intracellular Uropathogenic E. coli Bladder Infection

PubMed Central

Hannan, Thomas J.; Totsika, Makrina; Mansfield, Kylie J.; Moore, Kate H.; Schembri, Mark A.; Hultgren, Scott J.

2013-01-01

Bladder infections affect millions of people yearly, and recurrent symptomatic infections (cystitis) are very common. The rapid increase in infections caused by multi-drug resistant uropathogens threatens to make recurrent cystitis an increasingly troubling public health concern. Uropathogenic E. coli (UPEC) cause the vast majority of bladder infections. Upon entry into the lower urinary tract, UPEC face obstacles to colonization that constitute population bottlenecks, reducing diversity and selecting for fit clones. A critical mucosal barrier to bladder infection is the epithelium (urothelium). UPEC bypass this barrier when they invade urothelial cells and form intracellular bacterial communities (IBCs), a process which requires type 1 pili. IBCs are transient in nature, occurring primarily during acute infection. Chronic bladder infection is common and can be either latent, in the form of the Quiescent Intracellular Reservoir (QIR), or active, in the form of asymptomatic bacteriuria (ASB/ABU) or chronic cystitis. In mice, the fate of bladder infection: QIR, ASB, or chronic cystitis, is determined within the first 24 hours of infection and constitutes a putative host-pathogen mucosal checkpoint that contributes to susceptibility to recurrent cystitis. Knowledge of these checkpoints and bottlenecks is critical for our understanding of bladder infection and efforts to devise novel therapeutic strategies. PMID:22404313

Drug susceptibility and treatment response of common urinary tract infection pathogens in children.

PubMed

Chen, Pei-Chun; Chang, Luan-Yin; Lu, Chun-Yi; Shao, Pei-Lan; Tsai, I-Jung; Tsau, Yong-Kwei; Lee, Ping-Ing; Chen, Jong-Ming; Hsueh, Po-Ren; Huang, Li-Min

2014-12-01

To document the trends of sensitivity and to find whether it is necessary to change antibiotics in selected patients according to the sensitivity test results in our clinical practice. We collected urine culture results from 0-18-year-old patients in the National Taiwan University Hospital from January 1, 2003 to October 31, 2012. Their medical chart was reviewed to identify true pathogens responsible for their urinary tract infection (UTI). We checked the percentage of susceptibility of these pathogens to ampicillin, amoxicillin-clavulanate (AMC), cefazolin, cefmetazole, ceftriaxone, gentamicin, and trimethoprim-sulfamethoxazole (TMP-SMX) according to the Clinical and Laboratory Standards Institute (CLSI) guideline. The extended-spectrum-beta-lactamases (ESBLs) rate was also checked. In addition, we reviewed the treatment response of different antibiotics. Defervescence within 48 hours after initial antibiotics use was considered responsive. A total of 7758 urine cultures positive for Escherichia coli infection were collected during the 10-year period. The E. coli cefazolin susceptibility rate was 62-73% during 2003-2010, but it dropped to 23% in 2011 and 28% in 2012 after the new CLSI guideline (M100-S21) was released. However, other antibiotics did not show a significant difference. In UTI caused by E. coli, on average, the sensitivity rates for various antibiotics were as follows: cefmetazole, 90%; ceftriaxone, 85%; gentamicin, 77%; AMC, 61%; TMP-SMX, 47%; and ampicillin, 20%. The ESBL rate was also found to increase (2-11%; p < 0.01). The overall response rate of UTI caused by E. coli to first-line antibiotics such as first-generation cephalosporin and/or gentamicin was 78%. The susceptibility of common urinary tract pathogens to cefazolin has decreased dramatically since 2010. This trend may be due to the change in the CLSI guideline. Although the susceptibility rate to first-line empirical antibiotics shows a decreasing trend, we found that the clinical response was acceptable for our first-line empirical antibiotics. Copyright © 2013. Published by Elsevier B.V.

Arboviral etiologies of acute febrile illnesses in Western South America, 2000-2007.

PubMed

Forshey, Brett M; Guevara, Carolina; Laguna-Torres, V Alberto; Cespedes, Manuel; Vargas, Jorge; Gianella, Alberto; Vallejo, Efrain; Madrid, César; Aguayo, Nicolas; Gotuzzo, Eduardo; Suarez, Victor; Morales, Ana Maria; Beingolea, Luis; Reyes, Nora; Perez, Juan; Negrete, Monica; Rocha, Claudio; Morrison, Amy C; Russell, Kevin L; Blair, Patrick J; Olson, James G; Kochel, Tadeusz J

2010-08-10

Arthropod-borne viruses (arboviruses) are among the most common agents of human febrile illness worldwide and the most important emerging pathogens, causing multiple notable epidemics of human disease over recent decades. Despite the public health relevance, little is know about the geographic distribution, relative impact, and risk factors for arbovirus infection in many regions of the world. Our objectives were to describe the arboviruses associated with acute undifferentiated febrile illness in participating clinics in four countries in South America and to provide detailed epidemiological analysis of arbovirus infection in Iquitos, Peru, where more extensive monitoring was conducted. A clinic-based syndromic surveillance system was implemented in 13 locations in Ecuador, Peru, Bolivia, and Paraguay. Serum samples and demographic information were collected from febrile participants reporting to local health clinics or hospitals. Acute-phase sera were tested for viral infection by immunofluorescence assay or RT-PCR, while acute- and convalescent-phase sera were tested for pathogen-specific IgM by ELISA. Between May 2000 and December 2007, 20,880 participants were included in the study, with evidence for recent arbovirus infection detected for 6,793 (32.5%). Dengue viruses (Flavivirus) were the most common arbovirus infections, totaling 26.0% of febrile episodes, with DENV-3 as the most common serotype. Alphavirus (Venezuelan equine encephalitis virus [VEEV] and Mayaro virus [MAYV]) and Orthobunyavirus (Oropouche virus [OROV], Group C viruses, and Guaroa virus) infections were both observed in approximately 3% of febrile episodes. In Iquitos, risk factors for VEEV and MAYV infection included being male and reporting to a rural (vs urban) clinic. In contrast, OROV infection was similar between sexes and type of clinic. Our data provide a better understanding of the geographic range of arboviruses in South America and highlight the diversity of pathogens in circulation. These arboviruses are currently significant causes of human illness in endemic regions but also have potential for further expansion. Our data provide a basis for analyzing changes in their ecology and epidemiology.

Isolation and characterization of Escherichia coli pili from diverse clinical sources.

PubMed

Salit, I E; Vavougios, J; Hofmann, T

1983-11-01

Bacteria which attach to different mucous membranes should have differing specificities of adherence in vitro. Human Escherichia coli isolates from blood and urine (pathogens) and from stool and throat (commensals) were characterized as to the patterns of hemagglutination (HA), as well as the structure and function of their pili. Bacterial HA was done in microtiter plates and on slides after bacterial growth in broth or agar. Human erythrocytes were agglutinated by 95% of the pathogens and 65 to 70% of the commensals grown in broth or agar. Mannose-resistant HA was characteristically caused by pathogens, and commensals characteristically caused mannose-sensitive HA of guinea pig cells. Strains often had both mannose-resistant and mannose-sensitive reactions, or even a mannose-paradoxical reaction. Pathogens more often caused HA, but titers were lower than those for commensals. Slide HA was less sensitive than the microtiter method. All isolates were piliated. Commensals also had more pili than pathogens when grown in broth (117.8 versus 38.3 pili per bacterium), but pathogens had more pili after growth on agar (32.1 versus 8.1 pili per bacterium). Isolates causing high-titer HA had large numbers of pili (greater than 85 pili per bacterium), but some well-piliated strains were non-hemagglutinating. Pili were purified from seven E. coli strains from different sites of isolation and with different erythrocyte-binding specificity. Pili usually migrated as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. However, more than one type of pilus could be copurified from some strains since there were two or more bands after separation in octyl-glucoside and two different amino terminal sequences. Protein sequencing was done on five different pili: four resembled type 1 pili and one was a P fimbria. The type 1-like pili (strains 2239 and 9353) had an initial variable sequence of 1 to 5 residues, followed by a common region of 21 residues. The P fimbria (strain 7714) had different erythrocyte-binding specificity but was still 27% homologous with 2239 and 9353. E. coli strains from different body sites have characteristic attachments to erythrocytes. Pili derived from these different sources may also have different binding specificity, but they are similar in primary structure.

Isolation and characterization of Escherichia coli pili from diverse clinical sources.

PubMed Central

Salit, I E; Vavougios, J; Hofmann, T

1983-01-01

Bacteria which attach to different mucous membranes should have differing specificities of adherence in vitro. Human Escherichia coli isolates from blood and urine (pathogens) and from stool and throat (commensals) were characterized as to the patterns of hemagglutination (HA), as well as the structure and function of their pili. Bacterial HA was done in microtiter plates and on slides after bacterial growth in broth or agar. Human erythrocytes were agglutinated by 95% of the pathogens and 65 to 70% of the commensals grown in broth or agar. Mannose-resistant HA was characteristically caused by pathogens, and commensals characteristically caused mannose-sensitive HA of guinea pig cells. Strains often had both mannose-resistant and mannose-sensitive reactions, or even a mannose-paradoxical reaction. Pathogens more often caused HA, but titers were lower than those for commensals. Slide HA was less sensitive than the microtiter method. All isolates were piliated. Commensals also had more pili than pathogens when grown in broth (117.8 versus 38.3 pili per bacterium), but pathogens had more pili after growth on agar (32.1 versus 8.1 pili per bacterium). Isolates causing high-titer HA had large numbers of pili (greater than 85 pili per bacterium), but some well-piliated strains were non-hemagglutinating. Pili were purified from seven E. coli strains from different sites of isolation and with different erythrocyte-binding specificity. Pili usually migrated as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. However, more than one type of pilus could be copurified from some strains since there were two or more bands after separation in octyl-glucoside and two different amino terminal sequences. Protein sequencing was done on five different pili: four resembled type 1 pili and one was a P fimbria. The type 1-like pili (strains 2239 and 9353) had an initial variable sequence of 1 to 5 residues, followed by a common region of 21 residues. The P fimbria (strain 7714) had different erythrocyte-binding specificity but was still 27% homologous with 2239 and 9353. E. coli strains from different body sites have characteristic attachments to erythrocytes. Pili derived from these different sources may also have different binding specificity, but they are similar in primary structure. Images PMID:6139339

Model systems for the study of Enterococcal colonization and infection

PubMed Central

Goh, H. M. Sharon; Yong, M. H. Adeline; Chong, Kelvin Kian Long

2017-01-01

ABSTRACT Enterococcus faecalis and Enterococcus faecium are common inhabitants of the human gastrointestinal tract, as well as frequent opportunistic pathogens. Enterococci cause a range of infections including, most frequently, infections of the urinary tract, catheterized urinary tract, bloodstream, wounds and surgical sites, and heart valves in endocarditis. Enterococcal infections are often biofilm-associated, polymicrobial in nature, and resistant to antibiotics of last resort. Understanding Enterococcal mechanisms of colonization and pathogenesis are important for identifying new ways to manage and intervene with these infections. We review vertebrate and invertebrate model systems applied to study the most common E. faecalis and E. faecium infections, with emphasis on recent findings examining Enterococcal-host interactions using these models. We discuss strengths and shortcomings of each model, propose future animal models not yet applied to study mono- and polymicrobial infections involving E. faecalis and E. faecium, and comment on the significance of anti-virulence strategies derived from a fundamental understanding of host-pathogen interactions in model systems. PMID:28102784

Multilocus Sequence Types of Campylobacter jejuni Isolates from Different Sources in Eastern China.

PubMed

Zhang, Gong; Zhang, Xiaoyan; Hu, Yuanqing; Jiao, Xin-An; Huang, Jinlin

2015-09-01

Campylobacter jejuni is a major food-borne pathogen that causes human gastroenteritis in many developed countries. In our study, we applied multilocus sequence typing (MLST) technology to 167 C. jejuni isolates from diverse sources in Eastern China to examine their genetic diversity. MLST defined 94 sequence types (STs) belonging to 18 clonal complexes (CCs). Forty-five STs from 60 isolates (36%) and 22 alleles have not been previously documented in an international database. One hundred and two isolates, accounting for 61.1% of all isolates, belonged to eight clonal complexes. The eight major CCs were also the most common complexes from different sources. The most common ST type of isolates from human and food was ST-353. The dominant ST type in chicken and foods was ST-354. Among 21 STs that contained two or more different sources isolates, 15 STs contained human isolates and isolates from other sources, suggesting that potentially pathogenic strains are not restricted to specific lineages.

The diagnosis and management of respiratory viral infections in cystic fibrosis.

PubMed

Flight, William; Jones, Andrew

2017-03-01

Respiratory viruses, such as those that cause influenza and the common cold, are a regular feature of life for the entire human population. Among people with CF, these viruses are associated with prolonged respiratory illness and show a clear association with pulmonary exacerbations which in turn are associated with lung function decline and risk of death. Human rhinovirus is the most commonly encountered respiratory viral pathogen in CF although adenovirus, bocavirus, coronavirus, influenza, parainfluenza, metapneumovirus and respiratory syncytial virus are all also responsible for infections in this population. Areas covered: This article reviews the epidemiology, clinical impact and therapeutic options for respiratory virus infection in both children and adults with CF. Expert commentary: The management of CF to date has largely focused on airway clearance strategies, nutritional support and aggressive antibacterial therapy. We highlight the significant role that respiratory viruses play in CF lung disease and argue that these pathogens represent an under-exploited target in the battle to control patients' symptoms and disease progression.

Current Microbiology of Surgical Site Infections in Patients with Cancer: A Retrospective Review.

PubMed

Rolston, Kenneth V I; Nesher, Lior; Tarrand, Jeffrey T

2014-12-01

Patients with solid tumors frequently undergo surgical procedures and develop procedure-related infections. We sought to describe the current microbiologic spectrum of infections at various sites following common surgical procedures. This was a retrospective review of microbiologic data between January 2011 and February 2012. The sites studied were those associated with breast cancer surgery, thoracotomy, craniotomy, percutaneous endoscopic gastrostomy (PEG) tube insertion, and abdominal/pelvic surgery. Only patients with solid tumors were included. A total of 368 surgical site infections (SSIs) were identified (68 breast cancer related; 91 thoracotomy related; 45 craniotomy related; 75 PEG-tube insertion related; and 89 abdominal/pelvic surgery related). Of these, 58% were monomicrobial and 42% were polymicrobial. Overall, 85% of the 215 monomicrobial infections were caused by Gram-positive organisms and 13% by Gram-negative bacilli (GNB). Staphylococcus aureus was the predominant pathogen in monomicrobial infections (150 of 215, 70%). Sixty (40%) of these staphylococcal isolates were methicillin resistant (MRSA), and 65% had a vancomycin minimal inhibitory concentration (MIC) ≥1.0 µg/ml. Pseudomonas aeruginosa was the predominant GNB pathogen (19 of 27, 70%). Staphylococci were also the predominant pathogens in polymicrobial infections, while P. aeruginosa and Escherichia coli were the predominant GNB. Overall, 35% of isolates from polymicrobial infections were GNB. Cephalosporins (e.g., cefazolin) or amoxicillin/clavulanate was used most often for surgical prophylaxis, and 47% of organisms from monomicrobial infections (MRSA, P. aeruginosa) were resistant to them. A similar resistance pattern was observed in polymicrobial infections. Staphylococcus species were isolated most often from the sites studied. Polymicrobial infections (42%) and GNB monomicrobial infections (13%) were relatively frequent causes of SSIs. Many of these infections were caused by organisms that are resistant to agents commonly used for surgical prophylaxis. Additionally, 65% of staphylococcal isolates had a vancomycin MIC ≥1.0 µg/ml, suggesting the need for alternative therapeutic agents.

Altered virulence potential of Salmonella Enteritidis cultured in different foods: A cumulative effect of differential gene expression and immunomodulation.

PubMed

Jaiswal, Sangeeta; Sahoo, Prakash Kumar; Ryan, Daniel; Das, Jugal Kishore; Chakraborty, Eesha; Mohakud, Nirmal Kumar; Suar, Mrutyunjay

2016-08-02

Salmonella enterica serovars Enteritidis (S. Enteritidis) is one of the most common causes of food borne illness. Bacterial growth environment plays an important role in regulating gene expression thereby affecting the virulence profile of the bacteria. Different foods present diverse growth conditions which may affect the pathogenic potential of the bacteria. In the present study, the effect of food environments on the pathogenic potential of S. Enteritidis has been evaluated. S. Enteritidis was grown in different foods e.g. egg white, peanut butter and milk, and virulent phenotypes were compared to those grown in Luria Bertani broth. In-vivo experiments in C57BL/6 mice revealed S. Enteritidis grown in egg white did not induce significant (p<0.001) production of proinflammatory cytokines in mice and were unable to cause colitis despite efficient colonization in cecum, mesenteric lymph node, spleen and liver. Further studies revealed that bacteria grown in LB activated MAP Kinase and NFκB pathways efficiently, while those grown in egg white poorly activated the above pathways which can account for the decreased production of proinflammatory cytokines. qRT PCR analysis revealed SPI-1 effectors were downregulated in bacteria grown in egg white. Interestingly, bacteria grown in egg white showed reversal of phenotype upon change in growth media to LB. Additionally, bacteria grown in milk and peanut butter showed different degrees of virulence in mice as compared to those grown in LB media. Thus, the present study demonstrates that, S. Enteritidis grown in egg white colonizes systemic sites without causing colitis in a mouse model, while bacteria grown in milk and peanut butter show different pathogenicity profiles suggesting that food environments significantly affect the pathogenicity of S. Enteritidis. Copyright © 2016 Elsevier B.V. All rights reserved.

Mechanisms of Surface Antigenic Variation in the Human Pathogenic Fungus Pneumocystis jirovecii.

PubMed

Schmid-Siegert, Emanuel; Richard, Sophie; Luraschi, Amanda; Mühlethaler, Konrad; Pagni, Marco; Hauser, Philippe M

2017-11-07

Microbial pathogens commonly escape the human immune system by varying surface proteins. We investigated the mechanisms used for that purpose by Pneumocystis jirovecii This uncultivable fungus is an obligate pulmonary pathogen that in immunocompromised individuals causes pneumonia, a major life-threatening infection. Long-read PacBio sequencing was used to assemble a core of subtelomeres of a single P. jirovecii strain from a bronchoalveolar lavage fluid specimen from a single patient. A total of 113 genes encoding surface proteins were identified, including 28 pseudogenes. These genes formed a subtelomeric gene superfamily, which included five families encoding adhesive glycosylphosphatidylinositol (GPI)-anchored glycoproteins and one family encoding excreted glycoproteins. Numerical analyses suggested that diversification of the glycoproteins relies on mosaic genes created by ectopic recombination and occurs only within each family. DNA motifs suggested that all genes are expressed independently, except those of the family encoding the most abundant surface glycoproteins, which are subject to mutually exclusive expression. PCR analyses showed that exchange of the expressed gene of the latter family occurs frequently, possibly favored by the location of the genes proximal to the telomere because this allows concomitant telomere exchange. Our observations suggest that (i) the P. jirovecii cell surface is made of a complex mixture of different surface proteins, with a majority of a single isoform of the most abundant glycoprotein, (ii) genetic mosaicism within each family ensures variation of the glycoproteins, and (iii) the strategy of the fungus consists of the continuous production of new subpopulations composed of cells that are antigenically different. IMPORTANCE Pneumocystis jirovecii is a fungus causing severe pneumonia in immunocompromised individuals. It is the second most frequent life-threatening invasive fungal infection. We have studied the mechanisms of antigenic variation used by this pathogen to escape the human immune system, a strategy commonly used by pathogenic microorganisms. Using a new DNA sequencing technology generating long reads, we could characterize the highly repetitive gene families encoding the proteins that are present on the cellular surface of this pest. These gene families are localized in the regions close to the ends of all chromosomes, the subtelomeres. Such chromosomal localization was found to favor genetic recombinations between members of each gene family and to allow diversification of these proteins continuously over time. This pathogen seems to use a strategy of antigenic variation consisting of the continuous production of new subpopulations composed of cells that are antigenically different. Such a strategy is unique among human pathogens. Copyright © 2017 Schmid-Siegert et al.

Field efficacy of nonpathogenic Streptomyces species against potato common scab

USDA-ARS?s Scientific Manuscript database

Reports of potato fields suppressive to common scab (CS) and of association of non-pathogenic streptomycetes with CS resistance suggest that non-pathogenic strains have potential to control or modulate CS disease. Biocontrol potential of non-pathogenic Streptomyces was examined in field experiments ...

Prospective multi-centre sentinel surveillance for Haemophilus influenzae type b & other bacterial meningitis in Indian children

PubMed Central

Ramachandran, Padmanabhan; Fitzwater, Sean Patrick; Aneja, Satinder; Verghese, Valsan Philip; Kumar, Vishwajeet; Nedunchelian, Krishnamoorthy; Wadhwa, Nitya; Veeraraghavan, Balaji; Kumar, Rashmi; Meeran, Mohamed; Kapil, Arti; Jasmine, Sudha; Kumar, Aarti; Suresh, Saradha; Bhatnagar, Shinjini; Thomas, Kurien; Awasthi, Shally; Santosham, Mathuram; Chandran, Aruna

2013-01-01

Background & objectives: Haemophilus influenzae type b (Hib) is one of the leading bacterial causes of invasive disease in populations without access to Hib conjugate vaccines (Hib-CV). India has recently decided to introduce Hib-CV into the routine immunization programme in selected States. Longitudinal data quantifying the burden of bacterial meningitis and the proportion of disease caused by various bacteria are needed to track the impact of Hib-CV once introduced. A hospital-based sentinel surveillance network was established at four places in the country and this study reports the results of this ongoing surveillance. Methods: Children aged 1 to 23 months with suspected bacterial meningitis were enrolled in Chennai, Lucknow, New Delhi, and Vellore between July 2008 and June 2010. All cerebrospinal fluid (CSF) samples were tested using cytological, biochemical, and culture methods. Samples with abnormal CSF (≥10 WBC per μl) were tested by latex agglutination test for common paediatric bacterial meningitis pathogens. Results: A total of 708 patients with abnormal CSF were identified, 89 of whom had a bacterial pathogen confirmed. Hib accounted for the majority of bacteriologically confirmed cases, 62 (70%), while Streptococcus pneumoniae and group B Streptococcus were identified in 12 (13%) and seven (8%) cases, respectively. The other eight cases were a mix of other bacteria. The proportion of abnormal CSF and probable bacterial meningitis that was caused by Hib was 74 and 58 per cent lower at Christian Medical College (CMC), Vellore, which had a 41 per cent coverage of Hib-CV among all suspected meningitis cases, compared to the combined average proportion at the other three centres where a coverage between 1 and 8 per cent was seen (P<0.001 and P= 0.05, respectively). Interpretation & conclusions: Hib was found to be the predominant cause of bacterial meningitis in young children in diverse geographic locations in India. Possible indications of herd immunity was seen at CMC compared to sites with low immunization coverage with Hib-CV. As Hib is the most common pathogen in bacterial meningitis, Hib-CV would have a large impact on bacterial meningitis in Indian children. PMID:23703338

Prospective multi-centre sentinel surveillance for Haemophilus influenzae type b & other bacterial meningitis in Indian children.

PubMed

Ramachandran, Padmanabhan; Fitzwater, Sean Patrick; Aneja, Satinder; Verghese, Valsan Philip; Kumar, Vishwajeet; Nedunchelian, Krishnamoorthy; Wadhwa, Nitya; Veeraraghavan, Balaji; Kumar, Rashmi; Meeran, Mohamed; Kapil, Arti; Jasmine, Sudha; Kumar, Aarti; Suresh, Saradha; Bhatnagar, Shinjini; Thomas, Kurien; Awasthi, Shally; Santosham, Mathuram; Chandran, Aruna

2013-04-01

Haemophilus influenzae type b (Hib) is one of the leading bacterial causes of invasive disease in populations without access to Hib conjugate vaccines (Hib-CV). India has recently decided to introduce Hib-CV into the routine immunization programme in selected States. Longitudinal data quantifying the burden of bacterial meningitis and the proportion of disease caused by various bacteria are needed to track the impact of Hib-CV once introduced. A hospital-based sentinel surveillance network was established at four places in the country and this study reports the results of this ongoing surveillance. Children aged 1 to 23 months with suspected bacterial meningitis were enrolled in Chennai, Lucknow, New Delhi, and Vellore between July 2008 and June 2010. All cerebrospinal fluid (CSF) samples were tested using cytological, biochemical, and culture methods. Samples with abnormal CSF (≥10 WBC per μl) were tested by latex agglutination test for common paediatric bacterial meningitis pathogens. A total of 708 patients with abnormal CSF were identified, 89 of whom had a bacterial pathogen confirmed. Hib accounted for the majority of bacteriologically confirmed cases, 62 (70%), while Streptococcus pneumoniae and group B Streptococcus were identified in 12 (13%) and seven (8%) cases, respectively. The other eight cases were a mix of other bacteria. The proportion of abnormal CSF and probable bacterial meningitis that was caused by Hib was 74 and 58 per cent lower at Christian Medical College (CMC), Vellore, which had a 41 per cent coverage of Hib-CV among all suspected meningitis cases, compared to the combined average proportion at the other three centres where a coverage between 1 and 8 per cent was seen (P<0.001 and P= 0.05, respectively). Hib was found to be the predominant cause of bacterial meningitis in young children in diverse geographic locations in India. Possible indications of herd immunity was seen at CMC compared to sites with low immunization coverage with Hib-CV. As Hib is the most common pathogen in bacterial meningitis, Hib-CV would have a large impact on bacterial meningitis in Indian children.

Urinary tract infection during pregnancy: current concepts on a common multifaceted problem.

PubMed

Kalinderi, Kallirhoe; Delkos, Dimitrios; Kalinderis, Michail; Athanasiadis, Apostolos; Kalogiannidis, Ioannis

2018-02-06

Urinary tract infections (UTIs) are the most common bacterial infection in pregnancy, increasing the risk of maternal and neonatal morbidity and mortality. Urinary tract infections may present as asymptomatic bacteriuria, acute cystitis or pyelonephritis. Escherichia coli is the most common pathogen associated with both symptomatic and asymptomatic bacteriuria. If asymptomatic bacteriuria is untreated, up to 30% of mothers develop acute pyelonephritis, with an increased risk of multiple maternal and neonatal complications, such as preeclampsia, preterm birth, intrauterine growth restriction and low birth weight. Urinary tract infection is a common, but preventable cause of pregnancy complications, thus urinary tests, such as urine culture or new technologies such as high-throughput DNA sequence-based analyses, should be used in order to improve antenatal screening of pregnant women.

MICROBIAL CONTAMINATION OF STREET VENDED FOODS FROM A UNIVERSITY CAMPUS IN BANGLADESH.

PubMed

Islam, Sufia; Nasrin, Nishat; Rizwan, Farhana; Nahar, Lutfun; Bhowmik, Adity; Esha, Sayma Afrin; Talukder, Kaisar Ali; Akter, Mahmuda; Roy, Ajoy; Ahmed, Muniruddin

2015-05-01

The microbiological quality of street vended food samples from Dhaka, Bangladesh was evaluated. The objective of the study was to identify the presence of common pathogens (Escherichia coli, Shigella spp, Salmonella and Vibrio spp) and to describe the molecular characterization of E coli, a commonly found pathogen in various street foods. Fifty food samples were collected from fixed and mobile vendors from two sampling locations (Mohakhali and Aftabnagar) in Dhaka city, Bangladesh. The tested samples included deep fried and fried snacks; quick lunch items; pickles; fruit chutney; baked items; spicy, sour and hot snacks etc: Juices, tamarind water and plain drinking water were also tested. Sterile polythene bags were used for collecting 200 g of each category of samples. They were tested for the presence of microorganisms following conventional microbiological processes. Biochemical tests followed by serology were done for the confirmation of Shigella and Salmonella. Serological reaction was carried out for confirmation of Vibrio spp. DNA was isolated for the molecular characterization to detect the pathogenic E. coli by polymerase chain reaction (PCR). Out of 50 food samples, six (12%) were confirmed to contain different species of E. coli and Shigella. Molecular characterization of E. coli revealed that three samples were contaminated with enteroaggregative E. coli (EAEC) and one was contaminated with enterotoxigenic E. coli (ETEC). Shigellaflexneri X variant was detected in one food item and Shigella flexneri 2a was found in drinking water. All these enteric pathogens could be the potential cause for foodborne illnesses.

The Causes and Treatment Outcomes of 91 Patients with Adult Nosocomial Meningitis

PubMed Central

Kim, Hye-In; Park, Ga-Young; Kwon, Eu-Gene; Kim, Hyo-Hoon; Jeong, Ju-Young; Chang, Hyun-Ha; Lee, Jong-Myung; Kim, Neung-Su

2012-01-01

Background/Aims Frequent pathogens of nosocomial meningitis were investigated and the adequacy of empiric antibiotic therapy was assessed. Outcomes of nosocomial meningitis were also evaluated. Methods Ninety-one patients, who were diagnosed and treated for nosocomial meningitis at a single tertiary hospital in Daegu, Korea for 10 years, were included. Medical record and electronic laboratory data on the causative pathogens, antibiotics used, and outcomes were retrospectively investigated. Results Coagulase-negative Staphylococcus (40.9%) was the most common pathogen, followed by Acinetobacter (32.5%). Both were cultured as a single organism in cerebrospinal fluid (CSF). Seventy-eight patients (85.7%) had infections related to external ventricular drains (EVD). The most common empirical antibiotics were extended-spectrum beta-lactam antibiotics plus vancomycin (35/91, 38.6%). Of the 27 patients who had cultured Acinetobacter in CSF, 10 (37%) were given the wrong empirical antibiotic treatment. Seven of the 27 patients (26.9%) with cultured Acinetobacter died, and overall mortality of the 91 patients was 16.5%. In the multivariate analysis, the presence of combined septic shock (p < 0.001) and a persistent EVD state (p = 0.021) were associated with a poor prognosis. Conclusions Acinetobacter is one of the leading pathogens of nosocomial meningitis and may lead to inadequate coverage of empiric antibiotic therapy due to increasing resistance. An EVD should be removed early in cases of suspected nosocomial meningitis, and carbapenem might be required for the poor treatment response. PMID:22707889

Human microbiomes and their roles in dysbiosis, common diseases, and novel therapeutic approaches.

PubMed

Belizário, José E; Napolitano, Mauro

2015-01-01

The human body is the residence of a large number of commensal (non-pathogenic) and pathogenic microbial species that have co-evolved with the human genome, adaptive immune system, and diet. With recent advances in DNA-based technologies, we initiated the exploration of bacterial gene functions and their role in human health. The main goal of the human microbiome project is to characterize the abundance, diversity and functionality of the genes present in all microorganisms that permanently live in different sites of the human body. The gut microbiota expresses over 3.3 million bacterial genes, while the human genome expresses only 20 thousand genes. Microbe gene-products exert pivotal functions via the regulation of food digestion and immune system development. Studies are confirming that manipulation of non-pathogenic bacterial strains in the host can stimulate the recovery of the immune response to pathogenic bacteria causing diseases. Different approaches, including the use of nutraceutics (prebiotics and probiotics) as well as phages engineered with CRISPR/Cas systems and quorum sensing systems have been developed as new therapies for controlling dysbiosis (alterations in microbial community) and common diseases (e.g., diabetes and obesity). The designing and production of pharmaceuticals based on our own body's microbiome is an emerging field and is rapidly growing to be fully explored in the near future. This review provides an outlook on recent findings on the human microbiomes, their impact on health and diseases, and on the development of targeted therapies.

Human microbiomes and their roles in dysbiosis, common diseases, and novel therapeutic approaches

PubMed Central

Belizário, José E.; Napolitano, Mauro

2015-01-01

The human body is the residence of a large number of commensal (non-pathogenic) and pathogenic microbial species that have co-evolved with the human genome, adaptive immune system, and diet. With recent advances in DNA-based technologies, we initiated the exploration of bacterial gene functions and their role in human health. The main goal of the human microbiome project is to characterize the abundance, diversity and functionality of the genes present in all microorganisms that permanently live in different sites of the human body. The gut microbiota expresses over 3.3 million bacterial genes, while the human genome expresses only 20 thousand genes. Microbe gene-products exert pivotal functions via the regulation of food digestion and immune system development. Studies are confirming that manipulation of non-pathogenic bacterial strains in the host can stimulate the recovery of the immune response to pathogenic bacteria causing diseases. Different approaches, including the use of nutraceutics (prebiotics and probiotics) as well as phages engineered with CRISPR/Cas systems and quorum sensing systems have been developed as new therapies for controlling dysbiosis (alterations in microbial community) and common diseases (e.g., diabetes and obesity). The designing and production of pharmaceuticals based on our own body’s microbiome is an emerging field and is rapidly growing to be fully explored in the near future. This review provides an outlook on recent findings on the human microbiomes, their impact on health and diseases, and on the development of targeted therapies. PMID:26500616

First step in the differential diagnosis of folliculitis: cytology.

PubMed

Durdu, Murat; Ilkit, Macit

2013-02-01

Folliculitis is a superficial inflammation of the hair follicles, and can be observed in individuals of any age or race. The incidence of folliculitis is unknown because most patients only consult a doctor in cases of increasing lesions. There are various infectious and non-infectious causes of folliculitis, and the most common causative agent is Staphylococcus aureus. In addition, several Gram-negative bacterial, fungal, parasitic, and viral pathogens can cause follicular papules and pustules. In routine practice, however, these lesions are usually thought to be bacterial. Therefore, topical and/or systemic antibacterial treatment is recommended, but this involves the risk of being misused for months or even years. Cytology, a simple, rapid, inexpensive, and repeatable diagnostic method, can reveal various bacterial, fungal, viral, and parasitic pathogens. This review discusses the use of clinical sampling and staining of cytologic samples for the differential diagnosis of folliculitis, cytologic findings, and the frequency with which dermatologists use cytology to diagnose folliculitis, particularly in the age of molecular biology and more expensive, sophisticated investigations.

Developments in Fungal Taxonomy

PubMed Central

Guarro, Josep; Gené, Josepa; Stchigel, Alberto M.

1999-01-01

Fungal infections, especially those caused by opportunistic species, have become substantially more common in recent decades. Numerous species cause human infections, and several new human pathogens are discovered yearly. This situation has created an increasing interest in fungal taxonomy and has led to the development of new methods and approaches to fungal biosystematics which have promoted important practical advances in identification procedures. However, the significance of some data provided by the new approaches is still unclear, and results drawn from such studies may even increase nomenclatural confusion. Analyses of rRNA and rDNA sequences constitute an important complement of the morphological criteria needed to allow clinical fungi to be more easily identified and placed on a single phylogenetic tree. Most of the pathogenic fungi so far described belong to the kingdom Fungi; two belong to the kingdom Chromista. Within the Fungi, they are distributed in three phyla and in 15 orders (Pneumocystidales, Saccharomycetales, Dothideales, Sordariales, Onygenales, Eurotiales, Hypocreales, Ophiostomatales, Microascales, Tremellales, Poriales, Stereales, Agaricales, Schizophyllales, and Ustilaginales). PMID:10398676

Essential Oil from Sweet Potato Vines, a Potential New Natural Preservative, and an Antioxidant on Sweet Potato Tubers: Assessment of the Activity and the Constitution.

PubMed

Yuan, Bo; Xue, Ling-Wei; Zhang, Qiu-Yue; Kong, Wan-Wan; Peng, Jun; Kou, Meng; Jiang, Ji-Hong

2016-10-12

Pathogenic fungi and oxidation are the major factors that cause the deterioration of sweet potatoes and also cause the loss of quality that makes consumption unsafe. In the present study, the in vitro results demonstrate that the essential oil from sweet potato vines exhibits significantly enhanced activity compared to that of the control. Furthermore, the essential oil can actively inhibit the growth of some common microorganisms inducing pathogenic bacteria and fungi (inhibition rates above 50% at low concentrations). A total of 31 constituents were identified using GC-MS and confirmed that linalool and p-hydroxybenzoic acid are the major active ingredients. The experiment involving actual tubers showed that the essential oil could retains its quality and effectiveness again the fungus disease. This suggests that it could be used in the food industry to increase the shelf life of stored produce (tubers) to ensure food safety without the use of additives or preservatives.

Genotypic, physiological, and biochemical characterization of potentially pathogenic Acanthamoeba isolated from the environment in Cairo, Egypt.

PubMed

Tawfeek, Gihan Mostafa; Bishara, Sawsan Abdel-Hamid; Sarhan, Rania Mohammad; ElShabrawi Taher, Eman; ElSaady Khayyal, Amira

2016-05-01

Acanthamoebae are the most common opportunistic amphizoic protozoa that cause life-threatening granulomatous amoebic encephalitis in immunocompromised individuals and sight-threatening amoebic keratitis (AK) in contact lens wearers. The present work aimed to determine the presence of Acanthamoeba isolates in different environmental sources: water, soil, and dust in Cairo, Egypt and to characterize the pathogenic potential of the isolated Acanthamoeba using physiological and biochemical assays as well as determination of the genotypes in an attempt to correlate pathogenicity with certain genotypes. The study included the collection of 22 corneal scrapings from patients complaining of symptoms and signs indicative of acanthamoeba keratitis (AK) and 75 environmental samples followed by cultivation on non-nutrient agar plates preseeded with E. coli. Positive samples for Acanthamoeba were subjected to osmo- and thermo-tolerance assays and zymography analysis. Potentially pathogenic isolates were subjected to PCR amplification using genus-specific primer pair. Isolates were classified at the genotype level based on the sequence analysis of Acanthamoeba 18S rRNA gene (diagnostic fragment 3). The total detection rate for Acanthamoeba in environmental samples was 33.3 %, 31.4 % in water, 40 % in soil, and 20 % in dust samples. Three and two Acanthamoeba isolates from water and soil sources, respectively, had the potential for pathogenicity as they exhibited full range of pathogenic traits. Other 12 isolates were designated as weak potential pathogens. Only ten of the environmental isolates were positive in PCR and were classified by genotype analysis into T4 genotype (70 %), T3 (10 %) and T5 (20 %). Potential pathogens belonged to genotypes T4 (from water) and T5 (from soil) while weak potential pathogens belonged to genotypes T3 (from water) and T4 (from water and soil). Additionally, T7 genotype was isolated from keratitis patients. There is a considerable variation in the response of Acanthamoeba members of the same genotype to pathogenicity indicator assays making correlation of pathogenicity with certain genotypes difficult. Presence of potentially pathogenic Acanthamoeba isolates in habitats related directly to human populations represent a risk for human health. Isolation of Acanthamoeba genotype T7 from AK cases, which is commonly considered as nonpathogenic, might draw the attention to other Acanthamoeba genotypes considered as non pathogenic and reevaluate their role in production of human infections. To our knowledge, this is the first study on the presence and distribution of Acanthamoeba genotypes in the environment, Cairo, Egypt.

Epigenetics of human papillomaviruses

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

Johannsen, Eric; Department of Medicine, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53706; McArdle Laboratory for Cancer Research, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53706

Human papilllomaviruses (HPVs) are common human pathogens that infect cutaneous or mucosal epithelia in which they cause warts, self-contained benign lesions that commonly regress. The HPV life cycle is intricately tied to the differentiation of the host epithelium it infects. Mucosotropic HPVs are the most common sexually transmitted pathogen known to mankind. A subset of the mucosotropic HPVs, so-called high risk HPVs, is etiologically associated with numerous cancers of the anogenital tract, most notably the cervix, as well as a growing fraction of head and neck cancers. In these cancers, the HPV genome, which normally exists an a double stranded,more » circular, nuclear plasmid, is commonly found integrated into the host genome and expresses two viral oncogenes, E6 and E7, that are implicated in the development and maintainance of the cancers caused by these high risk HPVs. Numerous studies, primarily on the high risk HPV16, have documented that the methylation status of the viral genome changes not only in the context of the viral life cycle but also in the context of the progressive neoplastic disease that culminates in cancer. In this article, we summarize the knowledge gained from those studies. We also provide the first analysis of available ChIP-seq data on the occupancy of both epigentically modified histones as well as transcription factors on the high risk HPV18 genome in the context of HeLa cells, a cervical cancer-derived cell line that has been the subject of extensive analyses using this technique. - Highlights: • Methylation status of HPV genomes is dynamic. • Changes are seen in both the viral life cycle and neoplasia. • Histone modification status at LCR is predictive of transcription factor occupancy. • Novel transcription factor binding noted by ChIP-seq.« less

Wild ducks excrete highly pathogenic avian influenza virus H5N8 (2014-2015) without clinical or pathological evidence of disease.

PubMed

van den Brand, Judith M A; Verhagen, Josanne H; Veldhuis Kroeze, Edwin J B; van de Bildt, Marco W G; Bodewes, Rogier; Herfst, Sander; Richard, Mathilde; Lexmond, Pascal; Bestebroer, Theo M; Fouchier, Ron A M; Kuiken, Thijs

2018-04-18

Highly pathogenic avian influenza (HPAI) is essentially a poultry disease. Wild birds have traditionally not been involved in its spread, but the epidemiology of HPAI has changed in recent years. After its emergence in southeastern Asia in 1996, H5 HPAI virus of the Goose/Guangdong lineage has evolved into several sub-lineages, some of which have spread over thousands of kilometers via long-distance migration of wild waterbirds. In order to determine whether the virus is adapting to wild waterbirds, we experimentally inoculated the HPAI H5N8 virus clade 2.3.4.4 group A from 2014 into four key waterbird species-Eurasian wigeon (Anas penelope), common teal (Anas crecca), mallard (Anas platyrhynchos), and common pochard (Aythya ferina)-and compared virus excretion and disease severity with historical data of the HPAI H5N1 virus infection from 2005 in the same four species. Our results showed that excretion was highest in Eurasian wigeons for the 2014 virus, whereas excretion was highest in common pochards and mallards for the 2005 virus. The 2014 virus infection was subclinical in all four waterbird species, while the 2005 virus caused clinical disease and pathological changes in over 50% of the common pochards. In chickens, the 2014 virus infection caused systemic disease and high mortality, similar to the 2005 virus. In conclusion, the evidence was strongest for Eurasian wigeons as long-distance vectors for HPAI H5N8 virus from 2014. The implications of the switch in species-specific virus excretion and decreased disease severity may be that the HPAI H5 virus more easily spreads in the wild-waterbird population.

Molecular genetic techniques for gene manipulation in Candida albicans.

PubMed

Xu, Qiu-Rong; Yan, Lan; Lv, Quan-Zhen; Zhou, Mi; Sui, Xue; Cao, Yong-Bing; Jiang, Yuan-Ying

2014-05-15

Candida albicans is one of the most common fungal pathogen in humans due to its high frequency as an opportunistic and pathogenic fungus causing superficial as well as invasive infections in immunocompromised patients. An understanding of gene function in C. albicans is necessary to study the molecular basis of its pathogenesis, virulence and drug resistance. Several manipulation techniques have been used for investigation of gene function in C. albicans, including gene disruption, controlled gene expression, protein tagging, gene reintegration, and overexpression. In this review, the main cassettes containing selectable markers used for gene manipulation in C. albicans are summarized; the advantages and limitations of these cassettes are discussed concerning the influences on the target gene expression and the virulence of the mutant strains.

Laboratory Diagnosis of Infections in Cancer Patients: Challenges and Opportunities

PubMed Central

2016-01-01

Infections remain a significant cause of morbidity and mortality in cancer patients. The differential diagnosis for these patients is often wide, and the timely selection of the right clinical tests can have a significant impact on their survival. However, laboratory findings with current methodologies are often negative, challenging clinicians and laboratorians to continue the search for the responsible pathogen. Novel methodologies are providing increased sensitivity and rapid turnaround time to results but also challenging our interpretation of what is a clinically significant pathogen in cancer patients. This minireview provides an overview of the most common infections in cancer patients and discusses some of the challenges and opportunities for the clinical microbiologist supporting the care of cancer patients. PMID:27280421

[Recent achievements in the microbiological etiology of dental caries].

PubMed

Jing, Chen; Lei, Cheng; Xuedong, Zhou; Xian, Peng

2018-02-01

Dental caries is the most common chronic infectious disease of the oral cavity. The bacterium Streptococcus mutans is the sole pathogen that causes this disease. However, substantial evidence suggests that prevention and treatment strategies developed from traditional "cariogenic pathogen theory" are inefficient in reducing the prevalence of dental caries. An increasing number of individuals adopt the ecological view of the microbiota in the pathogenesis of dental caries. Recent technological improvements have enabled the detection and analysis of oral microorganisms, and many studies have focused on this area. The core microbiota is defined as a cluster of microbes playing critical roles in the initial and development phases of dental caries and may provide future direction for microorganism-related etiological studies.

Botrytis pseudocinerea Is a Significant Pathogen of Several Crop Plants but Susceptible to Displacement by Fungicide-Resistant B. cinerea Strains

PubMed Central

Plesken, Cecilia; Weber, Roland W. S.; Rupp, Sabrina; Leroch, Michaela

2015-01-01

Botrytis cinerea is one of the most important pathogens worldwide, causing gray mold on a large variety of crops. Botrytis pseudocinerea has been found previously to occur together with B. cinerea in low abundance in vineyards and strawberry fields. Here, we report B. pseudocinerea to be common and sometimes dominant over B. cinerea on several fruit and vegetable crops in Germany. On apples with calyx end rot and on oilseed rape, it was the major gray mold species. Abundance of B. pseudocinerea was often negatively correlated with fungicide treatments. On cultivated strawberries, it was frequently found in spring but was largely displaced by B. cinerea following fungicide applications. Whereas B. cinerea strains with multiple-fungicide resistance were common in these fields, B. pseudocinerea almost never developed resistance to any fungicide even though resistance mutations occurred at similar frequencies in both species under laboratory conditions. The absence of resistance to quinone outside inhibitors in B. pseudocinerea was correlated with an intron in cytB preventing the major G143A resistance mutation. Our work indicates that B. pseudocinerea has a wide host range similar to that of B. cinerea and that it can become an important gray mold pathogen on cultivated plants. PMID:26231644

Screening a UK amyotrophic lateral sclerosis cohort provides evidence of multiple origins of the C9orf72 expansion.

PubMed

Fratta, Pietro; Polke, James M; Newcombe, Jia; Mizielinska, Sarah; Lashley, Tammaryn; Poulter, Mark; Beck, Jon; Preza, Elisavet; Devoy, Anny; Sidle, Katie; Howard, Robin; Malaspina, Andrea; Orrell, Richard W; Clarke, Jan; Lu, Ching-Hua; Mok, Kin; Collins, Toby; Shoaii, Maryam; Nanji, Tina; Wray, Selina; Adamson, Gary; Pittman, Alan; Renton, Alan E; Traynor, Bryan J; Sweeney, Mary G; Revesz, Tamas; Houlden, Henry; Mead, Simon; Isaacs, Adrian M; Fisher, Elizabeth M C

2015-01-01

An expanded hexanucleotide repeat in the C9orf72 gene is the most common genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia (C9ALS/FTD). Although 0-30 hexanucleotide repeats are present in the general population, expansions >500 repeats are associated with C9ALS/FTD. Large C9ALS/FTD expansions share a common haplotype and whether these expansions derive from a single founder or occur more frequently on a predisposing haplotype is yet to be determined and is relevant to disease pathomechanisms. Furthermore, although cases carrying 50-200 repeats have been described, their role and the pathogenic threshold of the expansions remain to be identified and carry importance for diagnostics and genetic counseling. We present clinical and genetic data from a UK ALS cohort and report the detailed molecular study of an atypical somatically unstable expansion of 90 repeats. Our results across different tissues provide evidence for the pathogenicity of this repeat number by showing they can somatically expand in the central nervous system to the well characterized pathogenic range. Our results support the occurrence of multiple expansion events for C9ALS/FTD. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Homozygous nonsense mutation in SGCA is a common cause of limb-girdle muscular dystrophy in Assiut, Egypt.

PubMed

Reddy, Hemakumar M; Hamed, Sherifa A; Lek, Monkol; Mitsuhashi, Satomi; Estrella, Elicia; Jones, Michael D; Mahoney, Lane J; Duncan, Anna R; Cho, Kyung-Ah; Macarthur, Daniel G; Kunkel, Louis M; Kang, Peter B

2016-10-01

The genetic causes of limb-girdle muscular dystrophy (LGMD) have been studied in numerous countries, but such investigations have been limited in Egypt. A cohort of 30 families with suspected LGMD from Assiut, Egypt, was studied using immunohistochemistry, homozygosity mapping, Sanger sequencing, and whole exome sequencing. Six families were confirmed to have pathogenic mutations, 4 in SGCA and 2 in DMD. Of these, 3 families harbored a single nonsense mutation in SGCA, suggesting that this may be a common mutation in Assiut, Egypt, originating from a founder effect. The Assiut region in Egypt appears to share at least several of the common LGMD genes found in other parts of the world. It is notable that 4 of the 6 mutations were ascertained by means of whole exome sequencing, even though it was the last approach adopted. This illustrates the power of this technique for identifying causative mutations for muscular dystrophies. Muscle Nerve 54: 690-695, 2016. © 2016 Wiley Periodicals, Inc.

Relationship between antimicrobial susceptibility of clinical mastitis pathogens and treatment outcome in cows.

PubMed

Hoe, Fernanda G H; Ruegg, Pamela L

2005-11-01

To determine whether there was any association between results of in vitro antimicrobial susceptibility testing of pathogens isolated from cows with mild or moderate clinical mastitis and outcome of treatment. Observational study. 133 cows with mild or moderate mastitis in a single quarter. Cows were treated by means of intramammary infusion of pirlimycin (50 mg) in the affected quarter once daily for 2 days; additional intramammary treatments with the same product were administered if the milk continued to appear abnormal. Duration of treatment and days until clinical cure were recorded. Bacterial isolates were tested for antimicrobial susceptibility by means of a broth micro-dilution technique. Environmental streptococci, coliforms, and coagulase-negative Staphylococcus spp were the most commonly isolated pathogens. Duration of treatment and days until clinical cure were not significantly different for cows from which pathogens that were susceptible or resistant to pirlimycin were isolated. Bacteriologic cure rates 14 and 21 days after treatment were not significantly different for cows with mastitis caused by susceptible or resistant bacteria. Similar results were found when data only from cows with mastitis caused by gram-positive isolates were analyzed. In the present study, differences in clinical outcome for cows with mild or moderate mastitis that could be attributed to differences in results of in vitro susceptibility testing were not identified. The use of in vitro susceptibility testing to guide intramammary mastitis treatment cannot be recommended on the basis of results of this study.

Selection of endophytic fungi from comfrey (Symphytum officinale L.) for in vitro biological control of the phytopathogen Sclerotinia sclerotiorum (Lib.)

PubMed Central

Rocha, Rafaeli; da Luz, Daniela Eleutério; Engels, Cibelle; Pileggi, Sônia Alvim Veiga; de Souza Jaccoud Filho, David; Matiello, Rodrigo Rodrigues; Pileggi, Marcos

2009-01-01

Biological control consists of using one organism to attack another that may cause economic damage to crops. Integrated Pest Management (IPM) is a very common strategy. The white mold produced by Sclerotinia sclerotiorum (Lib.) causes considerable damage to bean crops. This fungus is a soil inhabitant, the symptoms of which are characterized by water-soaked lesions covered by a white cottony fungal growth on the soil surface and/or the host plant. Possible biological control agents taken from plants are being investigated as phytopathogen inhibitors. These are endophytic microorganisms that inhabit the intercellular spaces of vegetal tissues and are often responsible for antimicrobial production. The objective of the present study was to select endophytic fungi isolated from comfrey (Symphytum officinale L.) leaves with in vitro antagonist potential against the phytopathogenic fungus S. sclerotiorum. Twelve isolates of endophytic fungi and a pathogenic strain of S. sclerotiorum were used in the challenge method. With the aid of this method, four endophytes with the best antagonistic activity against S. sclerotiorum were selected. Pathogen growth inhibition zones were considered indicative of antibiosis. The percentages of pathogenic mycelia growth were measured both with and without the antagonist, resulting in growth reductions of 46.7% to 50.0% for S. sclerotiorum. These analyses were performed by evaluating the endophytic/pathogenic mycelia growth in mm/day over an eight-day period of antagonistic tests. PMID:24031320

Antimicrobial susceptibility of 22746 pathogens from Canadian hospitals: results of the CANWARD 2007-11 study.

PubMed

Zhanel, George G; Adam, Heather J; Baxter, Melanie R; Fuller, Jeff; Nichol, Kimberly A; Denisuik, Andrew J; Lagacé-Wiens, Philippe R S; Walkty, Andrew; Karlowsky, James A; Schweizer, Frank; Hoban, Daryl J

2013-05-01

The purpose of the CANWARD study was to assess the antimicrobial activity of a variety of available agents against 22,746 pathogens isolated from patients in Canadian hospitals between 2007 and 2011. Between 2007 and 2011, 27,123 pathogens were collected from tertiary-care centres from across Canada; 22,746 underwent antimicrobial susceptibility testing using CLSI broth microdilution methods. Patient demographic data were also collected. Of the isolates collected, 45.2%, 29.6%, 14.8% and 10.4% were from blood, respiratory, urine and wound specimens, respectively. Patient demographics were as follows: 54.4%/45.6% male/female, 12.8% ≤ 17 years old, 45.1% 18-64 years old and 42.1% ≥65 years old. Isolates were obtained from patients in medical and surgical wards (37.8%), emergency rooms (25.7%), clinics (18.0%) and intensive care units (18.5%). The three most common pathogens were Escherichia coli (20.1%), Staphylococcus aureus [methicillin-susceptible S. aureus and methicillin-resistant S. aureus (MRSA)] (20.0%) and Pseudomonas aeruginosa (8.0%), which together accounted for nearly half of the isolates obtained. Susceptibility rates (SRs) for E. coli were 100% meropenem, 99.9% tigecycline, 99.7% ertapenem, 97.7% piperacillin/tazobactam, 93.7% ceftriaxone, 90.5% gentamicin, 77.9% ciprofloxacin and 73.4% trimethoprim/sulfamethoxazole. Twenty-three percent of the S. aureus were MRSA. SRs for MRSA were 100% daptomycin, 100% linezolid, 100% telavancin, 99.9% vancomycin, 99.8% tigecycline, 92.2% trimethoprim/sulfamethoxazole and 48.2% clindamycin. SRs for P. aeruginosa were 90.1% amikacin, 93.1% colistin, 84.0% piperacillin/tazobactam, 83.5% ceftazidime, 82.6% meropenem, 72.0% gentamicin and 71.9% ciprofloxacin. The CANWARD surveillance study has provided important data on the antimicrobial susceptibility of pathogens commonly causing infections in Canadian hospitals.

Antimicrobial resistance among aerobic biofilm producing bacteria isolated from chronic wounds in the tertiary care hospitals of Peshawar, Pakistan.

PubMed

Rahim, K; Qasim, M; Rahman, H; Khan, T A; Ahmad, I; Khan, N; Ullah, A; Basit, A; Saleha, S

2016-08-01

Chronic wound infections impose major medical and economic costs on health-care systems, cause significant morbidity, mortality and prolonged hospitalisation. The presence of biofilm producing bacteria in these wounds is considered as an important virulence factor that leads to chronic implications including ulceration. The undertaken study aimed to isolate and identify the biofilm aerobic bacterial pathogens from patients with chronic wound infections, and determine their antibiotics resistance profiles Method: During this study, swab specimens were collected from patients with chronic wounds at teaching hospitals of Peshawar, Pakistan between May 2013 and June 2014. The isolated aerobic bacterial pathogens were identified on the basis of standard cultural characteristics and biochemical tests. Antibiotics resistance profiles of biofilm producing bacteria against selected antibiotics were then determined. Among the chronic wound infections, diabetic foot ulcers were most common 37 (37%), followed by surgical ulcers 27 (27%). Chronic wounds were common in male patients older than 40 years. Among the total 163 isolated bacterial pathogens the most prevalent bacterial species were Pseudomonas aeruginosa 44 (27%), Klebsiella pneumoniae 26 (16%), Staphylococcus species 22 (14%) and Streptococcus spp. 21 (13%). The isolation rate of bacterial pathogens was high among patients with diabetic foot ulcers 83 (50.9%). Among bacterial isolates, 108 (66.2%) were observed as biofilm producers while 55 (33.8%) did not form biofilm in our model. The investigated biofilm producing bacterial isolates showed comparatively high resistance against tested antibiotics compared to non-biofilm producing bacterial isolates. The most effective antibiotics were amikacine and cefepime against all isolates. Increased multidrug resistance in biofilm producing bacteria associated with chronic wounds was observed in this study. Judicious use of antibiotics is needed to control the wound associated biofilm associated pathogens.

Inefficient co-feeding transmission of Borrelia afzelii in two common European songbirds

PubMed Central

Heylen, Dieter J. A.; Sprong, Hein; Krawczyk, Aleksandra; Van Houtte, Natalie; Genné, Dolores; Gomez-Chamorro, Andrea; van Oers, Kees; Voordouw, Maarten J.

2017-01-01

The spirochete bacterium Borrelia afzelii is the most common cause of Lyme borreliosis in Europe. This tick-borne pathogen can establish systemic infections in rodents but not in birds. However, several field studies have recovered larval Ixodes ricinus ticks infected with B. afzelii from songbirds suggesting successful transmission of B. afzelii. We reviewed the literature to determine which songbird species were the most frequent carriers of B. afzelii-infected I. ricinus larvae and nymphs. We tested experimentally whether B. afzelii is capable of co-feeding transmission on two common European bird species, the blackbird (Turdus merula) and the great tit (Parus major). For each bird species, four naïve individuals were infested with B. afzelii-infected I. ricinus nymphal ticks and pathogen-free larval ticks. None of the co-feeding larvae tested positive for B. afzelii in blackbirds, but a low percentage of infected larvae (3.33%) was observed in great tits. Transstadial transmission of B. afzelii DNA from the engorged nymphs to the adult ticks was observed in both bird species. However, BSK culture found that these spirochetes were not viable. Our study suggests that co-feeding transmission of B. afzelii is not efficient in these two songbird species. PMID:28054584

Genome Sequence of the Necrotrophic Plant Pathogen Alternaria brassicicola Abra43

PubMed Central

Belmas, Elodie; Briand, Martial; Kwasiborski, Anthony; Colou, Justine; N’Guyen, Guillaume; Iacomi, Béatrice; Grappin, Philippe; Campion, Claire; Simoneau, Philippe; Barret, Matthieu

2018-01-01

ABSTRACT Alternaria brassicicola causes dark spot (or black spot) disease, which is one of the most common and destructive fungal diseases of Brassicaceae spp. worldwide. Here, we report the draft genome sequence of strain Abra43. The assembly comprises 29 scaffolds, with an N50 value of 2.1 Mb. The assembled genome was 31,036,461 bp in length, with a G+C content of 50.85%. PMID:29439047

Freeze-fracture of infected plant leaves in ethanol for scanning electron microscopic study of fungal pathogens.

PubMed

Moore, Jayma A; Payne, Scott A

2012-01-01

Fungi often are found within plant tissues where they cannot be visualized with the scanning electron microscope (SEM). We present a simple way to reveal cell interiors while avoiding many common causes of artifact. Freeze-fracture of leaf tissue using liquid nitrogen during the 100% ethanol step of the dehydration process just before critical point drying is useful in exposing intracellular fungi to the SEM.

Assessing the potential for maladaptation during active management of limber pine populations: A common garden study detects genetic differentiation in response to soil moisture in the Southern Rocky Mountains

Treesearch

Erin M. Borgman; Anna W. Schoettle; Amy L. Angert

2015-01-01

Active management is needed to sustain healthy limber pine (Pinus flexilis E. James) forests in the Southern Rocky Mountains (henceforth, Southern Rockies), as they are threatened by the interaction of the mountain pine beetle (Dendroctonus ponderosae Hopkins) epidemic, climate change, and the spread of the non-native pathogen that causes white pine blister...

Resistance profile for pathogens causing urinary tract infection in a pediatric population, and antibiotic treatment response at a university hospital, 2010-2011.

PubMed

Vélez Echeverri, Catalina; Serna-Higuita, Lina María; Serrano, Ana Katherina; Ochoa-García, Carolina; Rojas Rosas, Luisa; María Bedoya, Ana; Suárez, Margarita; Hincapié, Catalina; Henao, Adriana; Ortiz, Diana; Vanegas, Juan José; Zuleta, John Jairo; Espinal, David

2014-01-01

Urinary tract infection (UTI) is one of the most common bacterial infections in childhood and causes acute and chronic morbidity and long-term hypertension and chronic kidney disease. To describe the demographic characteristics, infectious agents, patterns of antibiotic resistance, etiologic agent and profile of susceptibility and response to empirical treatment of UTI in a pediatric population. This is a descriptive, retrospective study. Included in the study were 144 patients, 1:2.06 male to female ratio. The most common symptom was fever (79.9%) and 31.3% had a history of previous UTI. 72.0% of the patients had positive urine leukocyte count (>5 per field), urine gram was positive in 85.0% of samples and gram negative bacilli accounted for 77.8% for the total pathogens isolated. The most frequent uropathogens isolated were Escherichia coli and Klebsiella pneumoniae. Our E.coli isolates had a susceptibility rate higher than 90% to most of the antibiotics used, but a resistance rate of 42.6% to TMP SMX and 45.5% to ampicillin sulbactam. 6.3% of E. coli was extended-spectrum beta-lactamases producer strains. The most frequent empirical antibiotic used was amikacin, which was used in 66.0% of the patients. 17 of 90 patients who underwent voiding cistouretrography (VCUG) had vesicoureteral reflux. This study revealed that E. coli was the most frequent pathogen of community acquired UTI. We found that E. coli and other uropathogens had a high resistance rate against TMP SMX and ampicillin sulbactam. In order to ensure a successful empirical treatment, protocols should be based on local epidemiology and susceptibility rates.

Resistance profile for pathogens causing urinary tract infection in a pediatric population, and antibiotic treatment response at a University Hospital, 2010-2011

PubMed Central

Vélez Echeverri, Catalina; Serrano, Ana Katherina; Ochoa-García, Carolina; Rojas Rosas, Luisa; María Bedoya, Ana; Suárez, Margarita; Hincapié, Catalina; Henao, Adriana; Ortiz, Diana; Vanegas, Juan José; Zuleta, John Jairo; Espinal, David

2014-01-01

Introduction: Urinary tract infection (UTI) is one of the most common bacterial infections in childhood and causes acute and chronic morbidity and long-term hypertension and chronic kidney disease. Objectives: To describe the demographic characteristics, infectious agents, patterns of antibiotic resistance, etiologic agent and profile of susceptibility and response to empirical treatment of UTI in a pediatric population. Methods: This is a descriptive, retrospective study. Results: Included in the study were 144 patients, 1:2.06 male to female ratio. The most common symptom was fever (79.9%) and 31.3% had a history of previous UTI. 72.0% of the patients had positive urine leukocyte count (>5 per field), urine gram was positive in 85.0% of samples and gram negative bacilli accounted for 77.8% for the total pathogens isolated. The most frequent uropathogens isolated were Escherichia coli and Klebsiella pneumoniae. Our E.coli isolates had a susceptibility rate higher than 90% to most of the antibiotics used, but a resistance rate of 42.6% to TMP SMX and 45.5% to ampicillin sulbactam. 6.3% of E. coli was extended-spectrum beta-lactamases producer strains. The most frequent empirical antibiotic used was amikacin, which was used in 66.0% of the patients. 17 of 90 patients who underwent voiding cistouretrography (VCUG) had vesicoureteral reflux. Conclusion: This study revealed that E. coli was the most frequent pathogen of community acquired UTI. We found that E. coli and other uropathogens had a high resistance rate against TMP SMX and ampicillin sulbactam. In order to ensure a successful empirical treatment, protocols should be based on local epidemiology and susceptibility rates. PMID:24970958

Bacterial Prostatitis: Bacterial Virulence, Clinical Outcomes, and New Directions.

PubMed

Krieger, John N; Thumbikat, Praveen

2016-02-01

Four prostatitis syndromes are recognized clinically: acute bacterial prostatitis, chronic bacterial prostatitis, chronic prostatitis/chronic pelvic pain syndrome, and asymptomatic prostatitis. Because Escherichia coli represents the most common cause of bacterial prostatitis, we investigated the importance of bacterial virulence factors and antimicrobial resistance in E. coli strains causing prostatitis and the potential association of these characteristics with clinical outcomes. A structured literature review revealed that we have limited understanding of the virulence-associated characteristics of E. coli causing acute prostatitis. Therefore, we completed a comprehensive microbiological and molecular investigation of a unique strain collection isolated from healthy young men. We also considered new data from an animal model system suggesting certain E. coli might prove important in the etiology of chronic prostatitis/chronic pelvic pain syndrome. Our human data suggest that E. coli needs multiple pathogenicity-associated traits to overcome anatomic and immune responses in healthy young men without urological risk factors. The phylogenetic background and accumulation of an exceptional repertoire of extraintestinal pathogenic virulence-associated genes indicate that these E. coli strains belong to a highly virulent subset of uropathogenic variants. In contrast, antibiotic resistance confers little added advantage to E. coli strains in these healthy outpatients. Our animal model data also suggest that certain pathogenic E. coli may be important in the etiology of chronic prostatitis/chronic pelvic pain syndrome through mechanisms that are dependent on the host genetic background and the virulence of the bacterial strain.

Disturbance in forest ecosystems caused by pathogens and insects

Treesearch

Philip M. Wargo; Philip M. Wargo

1995-01-01

Pathogens and insects are major driving forces of processes in forested ecosystems. Disturbances caused by them are as intimately involved in ecosystem dynamics as the more sudden and obvious abiotic disturbances, for example, those caused by wind or fire. However, because pathogens and insects are selective and may affect only one or several related species of...

Development and Disease: How Susceptibility to an Emerging Pathogen Changes through Anuran Development

PubMed Central

Haislip, Nathan A.; Gray, Matthew J.; Hoverman, Jason T.; Miller, Debra L.

2011-01-01

Ranaviruses have caused die-offs of amphibians across the globe. In North America, these pathogens cause more amphibian mortality events than any other pathogen. Field observations suggest that ranavirus epizootics in amphibian communities are common during metamorphosis, presumably due to changes in immune function. However, few controlled studies have compared the relative susceptibility of amphibians to ranaviruses across life stages. Our objectives were to measure differences in mortality and infection prevalence following exposure to ranavirus at four developmental stages and determine whether the differences were consistent among seven anuran species. Based on previous studies, we hypothesized that susceptibility to ranavirus would be greatest at metamorphosis. Our results did not support this hypothesis, as four of the species were most susceptible to ranavirus during the larval or hatchling stages. The embryo stage had the lowest susceptibility among species probably due to the protective membranous layers of the egg. Our results indicate that generalizations should be made cautiously about patterns of susceptibility to ranaviruses among amphibian developmental stages and species. Further, if early developmental stages of amphibians are susceptible to ranaviruses, the impact of ranavirus epizootic events may be greater than realized due to the greater difficulty of detecting morbid hatchlings and larvae compared to metamorphs. PMID:21799820

[Non-viral sexually transmitted infections - Epidemiology, clinical manifestations, diagnostics and therapy : Part 2: Chlamydia and mycoplasma].

PubMed

Nenoff, P; Manos, A; Ehrhard, I; Krüger, C; Paasch, U; Helmbold, P; Handrick, W

2017-01-01

Chlamydia trachomatis is the most common pathogen of sexually transmitted bacterial infections worldwide. Every year in Germany approximately 300,000 new infections are to be expected. Chlamydia infections occur nearly exclusively in the postpubertal period. The peak age group is 15-25 years. The infection usually runs an asymptomatic course and the diagnosis is made by nucleic acid amplification techniques (NAAT) often after chlamydial screening or if complications occur. For treatment of chlamydial infections oral doxycycline 100 mg twice daily over 7 days is initially used or alternatively oral azithromycin 1.5 g as a single dose is recommended. The sexual partner should also be investigated and treated. Genital Mycoplasma infections are caused by Ureaplasma urealyticum (pathogen of urethritis and vaginitis), Ureaplasma parvum (mostly saprophytic and rarely a cause of urethritis) and Mycoplasma hominis (facultative pathogenic). Mycoplasma genitalium represents a relatively new sexually transmitted Mycoplasma species. Doxycycline is effective in Ureaplasma infections or alternatively clarithromycin and azithromycin. Doxycycline can be ineffective in Mycoplasma hominis infections and an alternative is clindamycin. Non-gonococcal and non-chlamydial urethritis due to Mycoplasma genitalium can now be diagnosed by molecular biological techniques using PCR and should be treated by azithromycin.

A molecular arms race between host innate antiviral response and emerging human coronaviruses.

PubMed

Wong, Lok-Yin Roy; Lui, Pak-Yin; Jin, Dong-Yan

2016-02-01

Coronaviruses have been closely related with mankind for thousands of years. Community-acquired human coronaviruses have long been recognized to cause common cold. However, zoonotic coronaviruses are now becoming more a global concern with the discovery of highly pathogenic severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) coronaviruses causing severe respiratory diseases. Infections by these emerging human coronaviruses are characterized by less robust interferon production. Treatment of patients with recombinant interferon regimen promises beneficial outcomes, suggesting that compromised interferon expression might contribute at least partially to the severity of disease. The mechanisms by which coronaviruses evade host innate antiviral response are under intense investigations. This review focuses on the fierce arms race between host innate antiviral immunity and emerging human coronaviruses. Particularly, the host pathogen recognition receptors and the signal transduction pathways to mount an effective antiviral response against SARS and MERS coronavirus infection are discussed. On the other hand, the counter-measures evolved by SARS and MERS coronaviruses to circumvent host defense are also dissected. With a better understanding of the dynamic interaction between host and coronaviruses, it is hoped that insights on the pathogenesis of newly-identified highly pathogenic human coronaviruses and new strategies in antiviral development can be derived.

A recombinase polymerase amplification assay for the diagnosis of atypical pneumonia.

PubMed

Kersting, Sebastian; Rausch, Valentina; Bier, Frank F; von Nickisch-Rosenegk, Markus

2018-04-18

Pneumonia is one of the most common and potentially lethal infectious conditions worldwide. Streptococcus pneumoniae is the pathogen most frequently associated with bacterial community-acquired pneumonia, while Legionella pneumophila is the major cause for local outbreaks of legionellosis. Both pathogens can be difficult to diagnose since signs and symptoms are nonspecific and do not differ from other causes of pneumonia. Therefore, a rapid diagnosis within a clinically relevant time is essential for a fast onset of the proper treatment. Although methods based on polymerase chain reaction significantly improved the identification of pathogens, they are difficult to conduct and need specialized equipment. We describe a rapid and sensitive test using isothermal recombinase polymerase amplification and detection on a disposable test strip. This method does not require any special instrumentation and can be performed in less than 20 min. The analytical sensitivity in the multiplex assay amplifying specific regions of S. pneumoniae and L. pneumophila simultaneously was 10 CFUs of genomic DNA per reaction. In cross detection studies with closely related strains and other bacterial agents the specificity of the RPA was confirmed. The presented method is applicable for near patient and field testing with a rather simple routine and the possibility for a read out with the naked eye. Copyright © 2018. Published by Elsevier Inc.

Novel pathogenic ACAN variants in non-syndromic short stature patients.

PubMed

Hu, Xuyun; Gui, Baoheng; Su, Jiasun; Li, Hongdou; Li, Niu; Yu, Tingting; Zhang, Qinle; Xu, Yufei; Li, Guoqiang; Chen, Yulin; Qing, Yanrong; Li, Chuan; Luo, Jingsi; Fan, Xin; Ding, Yu; Li, Juan; Wang, Jian; Wang, Xiumin; Chen, Shaoke; Shen, Yiping

2017-06-01

Pathogenic variants of ACAN have been reported to cause spondyloepiphyseal dysplasia Kimberley type, spondyloepimetaphyseal dysplasia, familial osteochondritis dissecans and idiopathic short stature with normal to advanced bone age. A recent international cohort study significantly expanded the ACAN mutation spectrum, further delineated the heterogeneous clinical characteristics of ACAN mutation patients. The prevalence of ACAN mutation in short stature patients is yet unknown. Here we set to assess the frequency of ACAN variants among a cohort of 218 Chinese children with non-syndromic short stature. We identified three novel truncating variants at the 5' end of ACAN gene. All these pathogenic variants co-segregate with severe short stature phenotype in families. In addition, none of the probands showed significant advanced bone age. All affected individuals showed no signs of significant dysmorphic features or skeletal abnormities. The prevalence of ACAN defect in this cohort is estimated to be 1.4% (3/218). It is higher among families with parents also affected with severe short stature, up to 7.0% (3/43) if parental height is <2.5 SD or 16.7% (3/18) if parental height is <3.0 SD. Our data suggest that ACAN mutation is a relative common cause of familial severe short stature. Copyright © 2017 Elsevier B.V. All rights reserved.

Pathogen Loading From Canada Geese Faeces in Freshwater: Potential Risks to Human Health Through Recreational Water Exposure.

PubMed

Gorham, T J; Lee, J

2016-05-01

Canada geese (Branta canadensis) faeces have been shown to contain pathogenic protozoa and bacteria in numerous studies over the past 15 years. Further, increases in both the Canada geese populations and their ideal habitat requirements in the United States (US) translate to a greater presence of these human pathogens in public areas, such as recreational freshwater beaches. Combining these factors, the potential health risk posed by Canada geese faeces at freshwater beaches presents an emerging public health issue that warrants further study. Here, literature concerning human pathogens in Canada geese faeces is reviewed and the potential impacts these pathogens may have on human health are discussed. Pathogens of potential concern include Campylobacter jejuni, Salmonella Typhimurium, Listeria monocytogenes, Helicobacter canadensis, Arcobacter spp., Enterohemorragic Escherichia coli pathogenic strains, Chlamydia psitacci, Cryptosporidium parvum and Giardia lamblia. Scenarios presenting potential exposure to pathogens eluted from faeces include bathers swimming in lakes, children playing with wet and dry sand impacted by geese droppings and other common recreational activities associated with public beaches. Recent recreational water-associated disease outbreaks in the US support the plausibility for some of these pathogens, including Cryptosporidium spp. and C. jejuni, to cause human illness in this setting. In view of these findings and the uncertainties associated with the real health risk posed by Canada geese faecal pathogens to users of freshwater lakes, it is recommended that beach managers use microbial source tracking and conduct a quantitative microbial risk assessment to analyse the local impact of Canada geese on microbial water quality during their decision-making process in beach and watershed management. © 2015 Blackwell Verlag GmbH.

Specific detection of Pectobacterium carotovorum by loop-mediated isothermal amplification.

PubMed

Yasuhara-Bell, Jarred; Marrero, Glorimar; De Silva, Asoka; Alvarez, Anne M

2016-12-01

Potatoes are an important agroeconomic crop worldwide and maceration diseases caused by pectolytic bacterial pathogens result in significant pre- and post-harvest losses. Pectobacterium carotovorum shares a common host range with other Pectobacterium spp. and other members of the Enterobacteriaceae, such as Dickeya spp. As these pathogens cannot be clearly differentiated on the basis of the symptoms they cause, improved methods of identification are critical for the determination of sources of contamination. Current standardized methods for the differentiation of pectolytic species are time consuming and require trained personnel, as they rely on traditional bacteriological practices that do not always produce conclusive results. In this growing world market, there is a need for rapid diagnostic tests that can differentiate between pectolytic pathogens, as well as separate them from non-pectolytic enteric bacteria associated with soft rots of potato. An assay has been designed previously to detect the temperate pathogen Pectobacterium atrosepticum, but there is currently no recognized rapid assay for the detection of the tropical/subtropical counterpart, Pectobacterium carotovorum. This report describes the development of a loop-mediated isothermal amplification (LAMP) assay that detects P. carotovorum with high specificity. The assay was evaluated using all known species of Pectobacterium and only showed positive reactions for P. carotovorum. This assay was also tested against 15 non-target genera of plant-associated bacteria and did not produce any false positives. The LAMP assay described here can be used as a rapid test for the differentiation of P. carotovorum from other pectolytic pathogens, and its gene target can be the basis for the development of other molecular-based detection assays. © 2016 BSPP and John Wiley & Sons Ltd.

The Causes of Post-Operative Meningitis: The Comparison Of Gram-Negative and Gram-Positive Pathogens.

PubMed

Kurtaran, Behice; Kuscu, Ferit; Ulu, Aslihan; Inal, Ayse Seza; Komur, Suheyla; Kibar, Filiz; Cetinalp, Nuri Eralp; Ozsoy, Kerem Mazhar; Arslan, Yusuf Kemal; Aksu, Hasan Salih; Tasova, Yesim

2017-06-20

In this study, we aim to determine the microbiological etiology in critically ill neurosurgical patients with nosocomial meningitis (NM) and show the impact of Gram-negative rods and differences of patient's characteristics, clinical and prognostic measures between Gram-negative and Gram-positive meningitis. In this prospective, one center study we reviewed all adult patients hospitalized during a 12-year period and identified pathogens isolated from post-neurosurgical cases of NM. Demographic, clinical, and treatment characteristics were noted from the medical records. Of the 134 bacterial NM patients, 78 were male and 56 were female, with a mean age of 46±15.9 and median age of 50 (18-80) years. 141 strains isolated; 82 (58.2%) were Gram negative, 59 (41.8%) were Gram positive. Most common isolated microorganism was Acinetobacter baumannii (%34.8). In comparison of mortality data shows that the patients who have meningitis with Gram-negative pathogens have higher mortality than with Gram positives (p=0.034). The duration between surgery and meningitis was shorter in Gram negative meningitis cases compared to others (p=0.045) but the duration between the diagnosis and death was shorter in Gram-positive meningitis cases compared to Gram negatives (p= 0.017). CSF protein and lactate level were higher and glucose level was lower in cases of NM with Gram negatives (p value were respectively, 0.022, 0.039 and 0.049). As conclusions; in NM, Gram-negative pathogens were seen more frequently; A.baumanni was the predominant pathogen; and NM caused by Gram negatives had worse clinical and laboratory characteristic and prognostic outcome than Gram positives.

Diseases and pathogens associated with mortality in Ontario beef feedlots.

PubMed

Gagea, Mihai I; Bateman, Kenneth G; van Dreumel, Tony; McEwen, Beverly J; Carman, Susy; Archambault, Marie; Shanahan, Rachel A; Caswell, Jeff L

2006-01-01

This study determined the prevalence of diseases and pathogens associated with mortality or severe morbidity in 72 Ontario beef feedlots in calves that died or were euthanized within 60 days after arrival. Routine pathologic and microbiologic investigations, as well as immunohistochemical staining for detection of bovine viral diarrhea virus (BVDV) antigen, were performed on 99 calves that died or were euthanized within 60 days after arrival. Major disease conditions identified included fibrinosuppurative bronchopneumonia (49%), caseonecrotic bronchopneumonia or arthritis (or both) caused by Mycoplasma bovis (36%), viral respiratory disease (19%), BVDV-related diseases (21%), Histophilus somni myocarditis (8%), ruminal bloat (2%), and miscellaneous diseases (8%). Viral infections identified were BVDV (35%), bovine respiratory syncytial virus (9%), bovine herpesvirus-1 (6%), parainfluenza-3 virus (3%), and bovine coronavirus (2%). Bacteria isolated from the lungs included M. bovis (82%), Mycoplasma arginini (72%), Ureaplasma diversum (25%), Mannheimia haemolytica (27%), Pasteurella multocida (19%), H. somni (14%), and Arcanobacterium pyogenes (19%). Pneumonia was the most frequent cause of mortality of beef calves during the first 2 months after arrival in feedlots, representing 69% of total deaths. The prevalence of caseonecrotic bronchopneumonia caused by M. bovis was similar to that of fibrinosuppurative bronchopneumonia, and together, these diseases were the most common causes of pneumonia and death. M. bovis pneumonia and polyarthritis has emerged as an important cause of mortality in Ontario beef feedlots.

The CommonGround Visual Paradigm for Biosurveillance

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

Livnat, Yarden; Jurrus, Elizabeth R.; Gundlapalli, Adi V.

2013-06-14

Biosurveillance is a critical area in the intelligence community for real-time detection of disease outbreaks. Identifying epidemics enables analysts to detect and monitor disease outbreaks that might be spread from natural causes or from possible biological warfare attacks. Containing these events and disseminating alerts requires the ability to rapidly find, classify and track harmful biological signatures. In this paper, we describe a novel visual paradigm to conduct biosurveillance using an Infectious Disease Weather Map. Our system provides a visual common ground in which users can view, explore and discover emerging concepts and correlations such as symptoms, syndromes, pathogens, and geographicmore » locations.« less

Tinea capitis: temporal shift in pathogens and epidemiology.

PubMed

Ziegler, Wiebke; Lempert, Sigrid; Goebeler, Matthias; Kolb-Mäurer, Annette

2016-08-01

Tinea capitis is the most common type of dermatomycosis in children. Its pathogen profile shows geographic variations as well as temporal shifts. Data from 150 patients with mycologically confirmed tinea capitis treated at the Department of Dermatology, University Hospital Würzburg, between 1990 and 2014 were analyzed with respect to gender, age, and pathogen spectrum. Two time periods, each 12.5 years long, were compared. Although tinea capitis was most frequently diagnosed in children between the ages of 0 and 5, the percentage of adults (16 %) was higher than previously reported. The zoophilic dermatophyte Microsporum canis was most frequently identified as the causative agent of tinea capitis. However, there was a rise in infections caused by the anthropophilic fungi Trichophyton tonsurans and Trichophyton rubrum, and also a trend towards a lower percentage of zoophilic versus anthropophilic pathogens. Over the course of time, we observed an increase in the diversity of the pathogen spectrum. Dermatophytes such as Trichophyton soudanense, the Trichophyton anamorph of Arthroderma benhamiae, Trichophyton schoenleinii, and Microsporum audouinii were isolated either for the first time or for the first time after a long hiatus. Although Microsporum canis infections still predominate, there has been an increase in anthropophilic pathogens. Given the unexpectedly high percentage of adults, tinea capitis should be included in the differential diagnostic considerations in all age groups. © 2016 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

Acute encephalitis in the immunocompromised individual.

PubMed

Saylor, Deanna; Thakur, Kiran; Venkatesan, Arun

2015-08-01

This article describes recent advances in the diagnosis and management of encephalitis in immunocompromised individuals. Herpes simplex virus (HSV) and varicella zoster virus (VZV) are common causes of encephalitis in immunocompromised individuals, although clinical manifestations may be atypical, and thus challenging to recognize. Recently, an increased incidence of HSV and VZV central nervous system infections has been reported in association with novel immunosuppressive and immunomodulatory treatments. The free-living ameba Balamuthia mandrillaris causes granulomatous encephalitis predominantly in immunocompromised individuals and is associated with nearly uniform fatality. In the setting of organ transplantation, the recipient's immunocompromised state along with the potential for donor-transmitted infections can result in a unique epidemiology of encephalitis, including infection by human herpes virus-6 and BK virus. Recent studies utilizing next-generation sequencing techniques have identified several pathogens, including Leptospira santarosai and a neurotropic astrovirus, as causes of encephalitis in immunocompromised individuals. Diagnosis and management of encephalitis is challenging in immunocompromised individuals, in part because of atypical clinical presentations and the presence of uncommon or novel infectious agents. Unbiased techniques for pathogen discovery are likely to play an increasing role in the diagnosis of central nervous system infections in immunocompromised individuals.

Host-directed therapies for infectious diseases: current status, recent progress, and future prospects.

PubMed

Zumla, Alimuddin; Rao, Martin; Wallis, Robert S; Kaufmann, Stefan H E; Rustomjee, Roxana; Mwaba, Peter; Vilaplana, Cris; Yeboah-Manu, Dorothy; Chakaya, Jeremiah; Ippolito, Giuseppe; Azhar, Esam; Hoelscher, Michael; Maeurer, Markus

2016-04-01

Despite extensive global efforts in the fight against killer infectious diseases, they still cause one in four deaths worldwide and are important causes of long-term functional disability arising from tissue damage. The continuing epidemics of tuberculosis, HIV, malaria, and influenza, and the emergence of novel zoonotic pathogens represent major clinical management challenges worldwide. Newer approaches to improving treatment outcomes are needed to reduce the high morbidity and mortality caused by infectious diseases. Recent insights into pathogen-host interactions, pathogenesis, inflammatory pathways, and the host's innate and acquired immune responses are leading to identification and development of a wide range of host-directed therapies with different mechanisms of action. Host-directed therapeutic strategies are now becoming viable adjuncts to standard antimicrobial treatment. Host-directed therapies include commonly used drugs for non-communicable diseases with good safety profiles, immunomodulatory agents, biologics (eg monoclonal antibodies), nutritional products, and cellular therapy using the patient's own immune or bone marrow mesenchymal stromal cells. We discuss clinically relevant examples of progress in identifying host-directed therapies as adjunct treatment options for bacterial, viral, and parasitic infectious diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

Aquatic Pseudomonads Inhibit Oomycete Plant Pathogens of Glycine max

PubMed Central

Wagner, Andrew; Norris, Stephen; Chatterjee, Payel; Morris, Paul F.; Wildschutte, Hans

2018-01-01

Seedling root rot of soybeans caused by the host-specific pathogen Phytophthora sojae, and a large number of Pythium species, is an economically important disease across the Midwest United States that negatively impacts soybean yields. Research on biocontrol strategies for crop pathogens has focused on compounds produced by microbes from soil, however, recent studies suggest that aquatic bacteria express distinct compounds that efficiently inhibit a wide range of pathogens. Based on these observations, we hypothesized that freshwater strains of pseudomonads might be producing novel antagonistic compounds that inhibit the growth of oomycetes. To test this prediction, we utilized a collection of 330 Pseudomonas strains isolated from soil and freshwater habitats, and determined their activity against a panel of five oomycetes: Phytophthora sojae, Pythium heterothalicum, Pythium irregulare, Pythium sylvaticum, and Pythium ultimum, all of which are pathogenic on soybeans. Among the bacterial strains, 118 exhibited antagonistic activity against at least one oomycete species, and 16 strains were inhibitory to all pathogens. Antagonistic activity toward oomycetes was significantly more common for aquatic isolates than for soil isolates. One water-derived strain, 06C 126, was predicted to express a siderophore and exhibited diverse antagonistic profiles when tested on nutrient rich and iron depleted media suggesting that more than one compound was produced that effectively inhibited oomycetes. These results support the concept that aquatic strains are an efficient source of compounds that inhibit pathogens. We outline a strategy to identify other strains that express unique compounds that may be useful biocontrol agents. PMID:29896163

NetF-producing Clostridium perfringens: Clonality and plasmid pathogenicity loci analysis.

PubMed

Mehdizadeh Gohari, Iman; Kropinski, Andrew M; Weese, Scott J; Whitehead, Ashley E; Parreira, Valeria R; Boerlin, Patrick; Prescott, John F

2017-04-01

Clostridium perfringens is an important cause of foal necrotizing enteritis and canine acute hemorrhagic diarrhea. A major virulence determinant of the strains associated with these diseases appears to be a beta-sheet pore-forming toxin, NetF, encoded within a pathogenicity locus (NetF locus) on a large tcp-conjugative plasmid. Strains producing NetF also produce the putative toxin NetE, encoded within the same pathogenicity locus, as well as CPE enterotoxin and CPB2 on a second plasmid, and sometimes the putative toxin NetG within a pathogenicity locus (NetG locus) on another separate large conjugative plasmid. Previous genome sequences of two netF-positive C. perfringens showed that they both shared three similar plasmids, including the NetF/NetE and CPE/CPB2 toxins-encoding plasmids mentioned above and a putative bacteriocin-encoding plasmid. The main purpose of this study was to determine whether all NetF-producing strains share this common plasmid profile and whether their distinct NetF and CPE pathogenicity loci are conserved. To answer this question, 15 equine and 15 canine netF-positive isolates of C. perfringens were sequenced using Illumina Hiseq2000 technology. In addition, the clonal relationships among the NetF-producing strains were evaluated by core genome multilocus sequence typing (cgMLST). The data obtained showed that all NetF-producing strains have a common plasmid profile and that the defined pathogenicity loci on the plasmids are conserved in all these strains. cgMLST analysis showed that the NetF-producing C. perfringens strains belong to two distinct clonal complexes. The pNetG plasmid was absent from isolates of one of the clonal complexes, and there were minor but consistent differences in the NetF/NetE and CPE/CPB2 plasmids between the two clonal complexes. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of qPCR systems to quantify shoot infections by canker-causing pathogens in stone fruits and nut crops.

PubMed

Luo, Y; Gu, S; Felts, D; Puckett, R D; Morgan, D P; Michailides, T J

2017-02-01

To develop real-time PCR assays for quantification of shoot infection levels of canker disease of stone fruits and nut crops caused by six fungal pathogen groups. This study focused on six major canker-causing fungal pathogen groups: Phomopsis sp., Botryosphaeria dothidea, Lasiodiplodia sp., Cytospora sp., Neofusicoccum sp. and Diplodia sp., occurring in stone fruits and nut crops in California. DNA primers were designed to specifically target each of the six pathogen groups after the specificity tests using canker-causing and non-canker-causing pathogens and by using DNA sequences of other species from GenBank using blast. The quantitative real-time PCR (qPCR) systems were developed and used to quantify the infection levels of inoculated dried plum shoots. For Neofusicoccum sp. and Phomopsis sp., which were used in inoculation of walnut shoots, the values of the molecular severity ranged from 5·60 to 6·94 during the 16 days of latent infection period. The qPCR assays were more efficient, accurate and precise to quantify latent infections caused by canker-causing pathogens as compared to the traditional plating methods. This study demonstrated the potential of using the developed qPCR systems for epidemiological studies on canker diseases of woody plants. © 2016 The Society for Applied Microbiology.

Under the lash

PubMed Central

Lacey, Noreen; Kavanagh, Kevin; Tseng, Scheffer C.G.

2010-01-01

Demodex mites, class Arachnida and subclass Acarina, are elongated mites with clear cephalothorax and abdomens, the former with four pairs of legs. There are more than 100 species of Demodex mite, many of which are obligatory commensals of the pilosebaceous unit of mammals including cats, dogs, sheep, cattle, pigs, goats, deer, bats, hamsters, rats and mice. Among them, Demodex canis, which is found ubiquitously in dogs, is the most documented and investigated. In excessive numbers D. canis causes the inflammatory disease termed demodicosis (demodectic mange, follicular mange or red mange), which is more common in purebred dogs and has a hereditary predisposition in breeding kennels1. Two distinct Demodex species have been confirmed as the most common ectoparasite in man. The larger Demodex folliculorum, about 0.3–0.4 mm long, is primarily found as a cluster in the hair follicle (Figure 1a), while the smaller Demodex brevis, about 0.2–0.3 mm long with a spindle shape and stubby legs, resides solitarily in the sebaceous gland (Figure 1b). These two species are also ubiquitously found in all human races without gender preference. The pathogenic role of Demodex mites in veterinary medicine is not as greatly disputed as in human diseases. In this article, we review the key literature and our joint research experience regarding the pathogenic potential of these two mites in causing inflammatory diseases of human skin and eye. We hope that the evidence summarized herein will invite readers to take a different look at the life of Demodex mites in several common human diseases. PMID:20664811

Under the lash: Demodex mites in human diseases.

PubMed

Lacey, Noreen; Kavanagh, Kevin; Tseng, Scheffer C G

2009-08-01

Demodex mites, class Arachnida and subclass Acarina, are elongated mites with clear cephalothorax and abdomens, the former with four pairs of legs. There are more than 100 species of Demodex mite, many of which are obligatory commensals of the pilosebaceous unit of mammals including cats, dogs, sheep, cattle, pigs, goats, deer, bats, hamsters, rats and mice. Among them, Demodex canis, which is found ubiquitously in dogs, is the most documented and investigated. In excessive numbers D. canis causes the inflammatory disease termed demodicosis (demodectic mange, follicular mange or red mange), which is more common in purebred dogs and has a hereditary predisposition in breeding kennels1. Two distinct Demodex species have been confirmed as the most common ectoparasite in man. The larger Demodex folliculorum, about 0.3-0.4 mm long, is primarily found as a cluster in the hair follicle (Figure 1a), while the smaller Demodex brevis, about 0.2-0.3 mm long with a spindle shape and stubby legs, resides solitarily in the sebaceous gland (Figure 1b). These two species are also ubiquitously found in all human races without gender preference. The pathogenic role of Demodex mites in veterinary medicine is not as greatly disputed as in human diseases. In this article, we review the key literature and our joint research experience regarding the pathogenic potential of these two mites in causing inflammatory diseases of human skin and eye. We hope that the evidence summarized herein will invite readers to take a different look at the life of Demodex mites in several common human diseases.

Differentiation of Yersinia enterocolitica biotype 1A from pathogenic Yersinia enterocolitica biotypes by detection of β-glucosidase activity: comparison of two chromogenic culture media and Vitek2.

PubMed

Karhukorpi, Jari; Päivänurmi, Marjut

2014-01-01

Aesculin hydrolysis (ESC) is one of the key reactions in differentiating pathogenic Yersinia enterocolitica biotypes 1B, 2, 3, 4 and 5 from the less-pathogenic biotype 1A. Because the ESC reaction is caused by β-glucosidase (βGLU) activity of the bacteria, we studied whether two commonly used methods (BBL CHROMagar Orientation and Vitek2 Gram-negative identification card) could be used in assessing βGLU activity of 74 Yersinia strains. Both methods were sensitive (100 % and 97 %) and specific (100 % and 100 %) in differentiating βGLU-positive YE BT1A from βGLU-negative Y. enterocolitica biotypes. For a subset of strains (n = 69), a new selective CHROMagar Yersinia showed excellent agreement with the strains' βGLU activity. Thus all the methods evaluated in this study may be used to differentiate between YE BT1A and other Y. enterocolitica biotypes.

Molecular detection of Dirofilaria immitis, Hepatozoon canis, Babesia spp., Anaplasma platys and Ehrlichia canis in dogs on Costa Rica.

PubMed

Wei, Lanjing; Kelly, Patrick; Ackerson, Kate; El-Mahallawy, Heba S; Kaltenboeck, Bernhard; Wang, Chengming

2014-03-01

Although vector-borne diseases are important causes of morbidity and mortality in dogs in tropical areas, there is little information on these conditions in Costa Rica. In PCRs of blood from dogs in Costa Rica, we did not detect DNAs of Rickettsia (R.) felis and Coxiella (C.) burnetii but we did find evidence of infection with Dirofilaria (D.) immitis (9/40, 22.5%), Hepatozoon (H.) canis (15/40, 37.5%), Babesia spp. (10/40, 25%; 2 with B. gibsoni and 8 with B. vogeli), Anaplasma (A.) platys (3/40, 7.5%) and Ehrlichia (E.) canis (20/40, 50%). Nine dogs (22.5%) were free of any vector-borne pathogens while 14 (35%) were infected with a single pathogen, 11 (27.5%) with two, 4 (10%) with three, 1 (2.5%) with four, and 1 (2.5%) with five pathogens. Dogs in Costa Rica are commonly infected with vector-borne agents.

Antigenic variability: Obstacles on the road to vaccines against traditionally difficult targets.

PubMed

Servín-Blanco, R; Zamora-Alvarado, R; Gevorkian, G; Manoutcharian, K

2016-10-02

Despite the impressive impact of vaccines on public health, the success of vaccines targeting many important pathogens and cancers has to date been limited. The burden of infectious diseases today is mainly caused by antigenically variable pathogens (AVPs), which escape immune responses induced by prior infection or vaccination through changes in molecular structures recognized by antibodies or T cells. Extensive genetic and antigenic variability is the major obstacle for the development of new or improved vaccines against "difficult" targets. Alternative, qualitatively new approaches leading to the generation of disease- and patient-specific vaccine immunogens that incorporate complex permanently changing epitope landscapes of intended targets accompanied by appropriate immunomodulators are urgently needed. In this review, we highlight some of the most critical common issues related to the development of vaccines against many pathogens and cancers that escape protective immune responses owing to antigenic variation, and discuss recent efforts to overcome the obstacles by applying alternative approaches for the rational design of new types of immunogens.

Indicator organisms in meat and poultry slaughter operations: their potential use in process control and the role of emerging technologies.

PubMed

Saini, Parmesh K; Marks, Harry M; Dreyfuss, Moshe S; Evans, Peter; Cook, L Victor; Dessai, Uday

2011-08-01

Measuring commonly occurring, nonpathogenic organisms on poultry products may be used for designing statistical process control systems that could result in reductions of pathogen levels. The extent of pathogen level reduction that could be obtained from actions resulting from monitoring these measurements over time depends upon the degree of understanding cause-effect relationships between processing variables, selected output variables, and pathogens. For such measurements to be effective for controlling or improving processing to some capability level within the statistical process control context, sufficiently frequent measurements would be needed to help identify processing deficiencies. Ultimately the correct balance of sampling and resources is determined by those characteristics of deficient processing that are important to identify. We recommend strategies that emphasize flexibility, depending upon sampling objectives. Coupling the measurement of levels of indicator organisms with practical emerging technologies and suitable on-site platforms that decrease the time between sample collections and interpreting results would enhance monitoring process control.

LAMP detection assays for boxwood blight pathogens: A comparative genomics approach

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

Malapi-Wight, Martha; Demers, Jill E.; Veltri, Daniel

Rapid and accurate molecular diagnostic tools are critical to efforts to minimize the impact and spread of emergent pathogens. The identification of diagnostic markers for novel pathogens presents several challenges, especially in the absence of information about population diversity and where genetic resources are limited. The objective of this study was to use comparative genomics datasets to find unique target regions suitable for the diagnosis of two fungal species causing a newly emergent blight disease of boxwood. Candidate marker regions for loop-mediated isothermal amplification (LAMP) assays were identified from draft genomes of Calonectria henricotiae and C. pseudonaviculata, as well asmore » three related species not associated with this disease. To increase the probability of identifying unique targets, we used three approaches to mine genome datasets, based on (i) unique regions, (ii) polymorphisms, and (iii) presence/absence of regions across datasets. From a pool of candidate markers, we demonstrate LAMP assay specificity by testing related fungal species, common boxwood pathogens, and environmental samples containing 445 diverse fungal taxa. In conclusion, this comparative-genomics-based approach to the development of LAMP diagnostic assays is the first of its kind for fungi and could be easily applied to diagnostic marker development for other newly emergent plant pathogens.« less

LAMP detection assays for boxwood blight pathogens: A comparative genomics approach

DOE PAGES

Malapi-Wight, Martha; Demers, Jill E.; Veltri, Daniel; ...

2016-05-20

Rapid and accurate molecular diagnostic tools are critical to efforts to minimize the impact and spread of emergent pathogens. The identification of diagnostic markers for novel pathogens presents several challenges, especially in the absence of information about population diversity and where genetic resources are limited. The objective of this study was to use comparative genomics datasets to find unique target regions suitable for the diagnosis of two fungal species causing a newly emergent blight disease of boxwood. Candidate marker regions for loop-mediated isothermal amplification (LAMP) assays were identified from draft genomes of Calonectria henricotiae and C. pseudonaviculata, as well asmore » three related species not associated with this disease. To increase the probability of identifying unique targets, we used three approaches to mine genome datasets, based on (i) unique regions, (ii) polymorphisms, and (iii) presence/absence of regions across datasets. From a pool of candidate markers, we demonstrate LAMP assay specificity by testing related fungal species, common boxwood pathogens, and environmental samples containing 445 diverse fungal taxa. In conclusion, this comparative-genomics-based approach to the development of LAMP diagnostic assays is the first of its kind for fungi and could be easily applied to diagnostic marker development for other newly emergent plant pathogens.« less

Protein Chips for Detection of Salmonella spp. from Enrichment Culture

PubMed Central

Poltronieri, Palmiro; Cimaglia, Fabio; De Lorenzis, Enrico; Chiesa, Maurizio; Mezzolla, Valeria; Reca, Ida Barbara

2016-01-01

Food pathogens are the cause of foodborne epidemics, therefore there is a need to detect the pathogens in food productions rapidly. A pre-enrichment culture followed by selective agar plating are standard detection methods. Molecular methods such as qPCR have provided a first rapid protocol for detection of pathogens within 24 h of enrichment culture. Biosensors also may provide a rapid tool to individuate a source of Salmonella contamination at early times of pre-enrichment culture. Forty mL of Salmonella spp. enrichment culture were processed by immunoseparation using the Pathatrix, as in AFNOR validated qPCR protocols. The Salmonella biosensor combined with immunoseparation showed a limit of detection of 100 bacteria/40 mL, with a 400 fold increase to previous results. qPCR analysis requires processing of bead-bound bacteria with lysis buffer and DNA clean up, with a limit of detection of 2 cfu/50 μL. Finally, a protein chip was developed and tested in screening and identification of 5 common pathogen species, Salmonella spp., E. coli, S. aureus, Campylobacter spp. and Listeria spp. The protein chip, with high specificity in species identification, is proposed to be integrated into a Lab-on-Chip system, for rapid and reproducible screening of Salmonella spp. and other pathogen species contaminating food productions. PMID:27110786

Role of the sseK1 gene in the pathogenicity of Salmonella enterica serovar enteritidis in vitro and in vivo.

PubMed

Yang, Yadong; Yu, Chuan; Ding, Ke; Zhang, Chunjie; Liao, Chengshui; Jia, Yanyan; Li, Jing; Cheng, Xiangchao

2018-04-01

Salmonella enteritidis is a common food-borne pathogen associated with consumption of contaminated poultry meat and eggs, which frequently causes gastroenteritis in humans. Salmonella secreted effector K1 (SseK1), as a translocated and secreted protein has been identified to be essential for the virulence of Salmonella typhimurium in host cells. However, the role of the sseK1 gene in the pathogenicity of S. enteritidis remain unclear. In this study, a sseK1 deletion mutant of S. enteritidis was constructed and its biological characteristics were examined. It was found that the sseK1 deletion mutant did not affect the growth, adherence and invasion of Salmonella enteritidis when compared to the wild-type S. enteritidis. However, the mutant showed decreased formation of biofilm and significantly reduced intracellular survival of bacteria in activated mouse peritoneal macrophages, as well as showed reduced pathogenicity to a murine model by increasing the lethal dose 50% (LD 50 ) value and decreasing the proliferation ratio of bacteria in vivo. Taken together, this study determined an important role for SseK1 in the pathogenicity of S. enteritidis in vitro and in vivo. Copyright © 2018 Elsevier Ltd. All rights reserved.

Challenges imposed by minor reference alleles on the identification and reporting of clinical variants from exome data.

PubMed

Koko, Mahmoud; Abdallah, Mohammed O E; Amin, Mutaz; Ibrahim, Muntaser

2018-01-15

The conventional variant calling of pathogenic alleles in exome and genome sequencing requires the presence of the non-pathogenic alleles as genome references. This hinders the correct identification of variants with minor and/or pathogenic reference alleles warranting additional approaches for variant calling. More than 26,000 Exome Aggregation Consortium (ExAC) variants have a minor reference allele including variants with known ClinVar disease alleles. For instance, in a number of variants related to clotting disorders, the phenotype-associated allele is a human genome reference allele (rs6025, rs6003, rs1799983, and rs2227564 using the assembly hg19). We highlighted how the current variant calling standards miss homozygous reference disease variants in these sites and provided a bioinformatic panel that can be used to screen these variants using commonly available variant callers. We present exome sequencing results from an individual with venous thrombosis to emphasize how pathogenic alleles in clinically relevant variants escape variant calling while non-pathogenic alleles are detected. This article highlights the importance of specialized variant calling strategies in clinical variants with minor reference alleles especially in the context of personal genomes and exomes. We provide here a simple strategy to screen potential disease-causing variants when present in homozygous reference state.

Fever in immunocompromised hosts.

PubMed

Patel, Devang M; Riedel, David J

2013-11-01

Fever is one of the most common reasons for the emergency department presentation of immunocompromised patients. Their differential diagnosis can be broad and includes rare or unexpected pathogens. Certain infectious causes of fever portend true emergencies; if they are not managed appropriately, rapid progression and death may ensue. This article reviews the diagnosis and management of fevers in patients immunocompromised by human immunodeficiency virus/AIDS, solid-organ and hematopoietic transplants, chemotherapy-induced neutropenia, and tumor necrosis factor-α inhibitors. Prompt recognition of the type of immunosuppression and delineation of possible causes of fever are critical for management of these complex patients. Copyright © 2013 Elsevier Inc. All rights reserved.

Whole-Body Microbiota of Sea Cucumber (Apostichopus japonicus) from South Korea for Improved Seafood Management.

PubMed

Kim, Tae-Yoon; Lee, Jin-Jae; Kim, Bong-Soo; Choi, Sang Ho

2017-10-28

Sea cucumber ( Apostichopus japonicus ) is a popular seafood source in Asia, including South Korea, and its consumption has recently increased with recognition of its medicinal properties. However, because raw sea cucumber contains various microbes, its ingestion can cause foodborne illness. Therefore, analysis of the microbiota in the whole body of sea cucumber can extend our understanding of foodborne illness caused by microorganisms and help to better manage products. We collected 40 sea cucumbers from four different sites in August and November, which are known as the maximum production areas in Korea. The microbiota was analyzed by an Illumina MiSeq system, and bacterial amounts were quantified by real-time PCR. The diversity and bacterial amounts in sea cucumber were higher in August than in November. Alpha-, Beta-, and Gammaproteobacteria were common dominant classes in all samples. However, the microbiota composition differed according to sampling time and site. Staphylococcus warneri and Propionibacterium acnes were commonly detected potential pathogens in August and November samples, respectively. The effect of experimental Vibrio parahaemolyticus infection on the indigenous microbiota of sea cucumber was analyzed at different temperatures, revealing clear alterations of Psychrobacter and Moraxella ; thus, these shifts can be used as indicators for monitoring infection of sea cucumber. Although further studies are needed to clarify and understand the virulence and mechanisms of the identified pathogens of sea cucumber, our study provides a valuable reference for determining the potential of foodborne illness caused by sea cucumber ingestion and to develop monitoring strategies of products using microbiota information.

Spontaneous gram-negative bacillary meningitis in adult patients: characteristics and outcome.

PubMed

Pomar, Virginia; Benito, Natividad; López-Contreras, Joaquin; Coll, Pere; Gurguí, Mercedes; Domingo, Pere

2013-09-30

Spontaneous meningitis caused by gram-negative bacilli in adult patients is uncommon and poorly characterized. Our objective is to describe and compare the characteristics and the outcome of adult patients with spontaneous gram-negative bacilli meningitis (GNBM) and spontaneous meningitis due to other pathogens. Prospective single hospital-based observational cohort study conducted between 1982 and 2006 in a university tertiary hospital in Barcelona (Spain). The Main Outcome Measure: In-hospital mortality. Gram-negative bacilli meningitis was diagnosed in 40 (7%) of 544 episodes of spontaneous acute bacterial meningitis. The most common pathogens were Escherichia coli and Pseudomonas species. On admission, characteristics associated with spontaneous gram-negative bacilli meningitis by multivariate modeling were advanced age, history of cancer, nosocomial acquisition of infection, urinary tract infection as distant focus of infection, absence of rash, hypotension, and a high cerebrospinal fluid white-cell count. Nine (23%) episodes were acquired in the hospital and they were most commonly caused by Pseudomonas. The in-hospital mortality rate was 53%. The mortality rate was higher among patients with Gram-negative bacillary meningitis than among those with other bacterial meningitis and their risk of death was twenty times higher than among patients infected with Neisseria meningitidis (odds ratio 20.47; 95% confidence interval 4.03-103.93; p<0.001). Gram-negative bacilli cause 9% of spontaneous bacterial meningitis of known etiology in adults. Characteristics associated with GNBM include advanced age, history of cancer, nosocomial acquisition, and urinary tract infection as distant focus of infection. The mortality rate is higher among patients with gram-negative bacillary meningitis than among those with other bacterial meningitides.

A breath fungal secondary metabolite signature to diagnose invasive aspergillosis.

PubMed

Koo, Sophia; Thomas, Horatio R; Daniels, S David; Lynch, Robert C; Fortier, Sean M; Shea, Margaret M; Rearden, Preshious; Comolli, James C; Baden, Lindsey R; Marty, Francisco M

2014-12-15

Invasive aspergillosis (IA) remains a leading cause of mortality in immunocompromised patients, in part due to the difficulty of diagnosing this infection. Using thermal desorption-gas chromatography/mass spectrometry, we characterized the in vitro volatile metabolite profile of Aspergillus fumigatus, the most common cause of IA, and other pathogenic aspergilli. We prospectively collected breath samples from patients with suspected invasive fungal pneumonia from 2011 to 2013, and assessed whether we could discriminate patients with proven or probable IA from patients without aspergillosis, as determined by European Organization for Research and Treatment of Cancer/Mycoses Study Group consensus definitions, by direct detection of fungal volatile metabolites in these breath samples. The monoterpenes camphene, α- and β-pinene, and limonene, and the sesquiterpene compounds α- and β-trans-bergamotene were distinctive volatile metabolites of A. fumigatus in vitro, distinguishing it from other pathogenic aspergilli. Of 64 patients with suspected invasive fungal pneumonia based on host risk factors, clinical symptoms, and radiologic findings, 34 were diagnosed with IA, whereas 30 were ultimately diagnosed with other causes of pneumonia, including other invasive mycoses. Detection of α-trans-bergamotene, β-trans-bergamotene, a β-vatirenene-like sesquiterpene, or trans-geranylacetone identified IA patients with 94% sensitivity (95% confidence interval [CI], 81%-98%) and 93% specificity (95% CI, 79%-98%). In patients with suspected fungal pneumonia, an Aspergillus secondary metabolite signature in breath can identify individuals with IA. These results provide proof-of-concept that direct detection of exogenous fungal metabolites in breath can be used as a novel, noninvasive, pathogen-specific approach to identifying the precise microbial cause of pneumonia. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Successful heart transplantation in patients with total artificial heart infections.

PubMed

Taimur, Sarah; Sullivan, Timothy; Rana, Mennakshi; Patel, Gopi; Roldan, Julie; Ashley, Kimberly; Pinney, Sean; Anyanwu, Anelechi; Huprikar, Shirish

2018-02-01

Data are limited on clinical outcomes in patients awaiting heart transplant (HT) with total artificial heart (TAH) infections. We retrospectively reviewed all TAH recipients at our center. TAH infection was classified as definite if a microorganism was isolated in cultures from the exit site or deep tissues around the TAH; as probable in patients without surgical or microbiologic evidence of infection but no other explanation for persistent or recurrent bloodstream infection (BSI); or possible in patients with clinical suspicion and radiographic findings suggestive of TAH infection, but without surgical intervention or microbiologic evidence. From 2012 to 2015, a total of 13 patients received a TAH, with a median age at implantation of 52 years (range: 28-60). TAH infection occurred in nine patients (seven definite, one probable, one possible) a median of 41 days after implant (range: 17-475). The majority of TAH infections were caused by Staphylococcus species. Seven of nine patients underwent HT (four had pre-HT mediastinal washout, and five had positive HT operative cultures). Three patients had an active BSI caused by the same pathogen causing TAH infection at the time of HT, with one developing a post-HT BSI with the same bacteria. No patient developed post-HT surgical site infection caused by the TAH infection pathogen. No deaths among HT recipients were attributed to infection. TAH infection is frequently associated with BSI and mediastinitis and Staphylococcus was the most common pathogen. A multimodal approach of appropriate pre- and post-HT antimicrobial therapy, surgical drainage, and heart transplantation with radical mediastinal debridement was successful in curing infection. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Bacillus cereus and related species.

PubMed

Drobniewski, F A

1993-10-01

Bacillus cereus is a gram-positive aerobic or facultatively anaerobic spore-forming rod. It is a cause of food poisoning, which is frequently associated with the consumption of rice-based dishes. The organism produces an emetic or diarrheal syndrome induced by an emetic toxin and enterotoxin, respectively. Other toxins are produced during growth, including phospholipases, proteases, and hemolysins, one of which, cereolysin, is a thiol-activated hemolysin. These toxins may contribute to the pathogenicity of B. cereus in nongastrointestinal disease. B. cereus isolated from clinical material other than feces or vomitus was commonly dismissed as a contaminant, but increasingly it is being recognized as a species with pathogenic potential. It is now recognized as an infrequent cause of serious nongastrointestinal infection, particularly in drug addicts, the immunosuppressed, neonates, and postsurgical patients, especially when prosthetic implants such as ventricular shunts are inserted. Ocular infections are the commonest types of severe infection, including endophthalmitis, panophthalmitis, and keratitis, usually with the characteristic formation of corneal ring abscesses. Even with prompt surgical and antimicrobial agent treatment, enucleation of the eye and blindness are common sequelae. Septicemia, meningitis, endocarditis, osteomyelitis, and surgical and traumatic wound infections are other manifestations of severe disease. B. cereus produces beta-lactamases, unlike Bacillus anthracis, and so is resistant to beta-lactam antibiotics; it is usually susceptible to treatment with clindamycin, vancomycin, gentamicin, chloramphenicol, and erythromycin. Simultaneous therapy via multiple routes may be required.

Central nervous system infection due to Cryptococcus gattii sensu lato in India: Analysis of clinical features, molecular profile and antifungal susceptibility.

PubMed

Lahiri Mukhopadhyay, Shayanki; Bahubali, Veenakumari H; Manjunath, Netravathi; Swaminathan, Aarthi; Maji, Sayani; Palaniappan, Marimuthu; Parthasarathy, Satishchandra; Chandrashekar, Nagarathna

2017-11-01

Cryptococcus gattii species complex has evolved as a pathogen in the last two decades causing infection among both immunocompetent and immunocompromised hosts. We aimed to analyse the clinical features of CNS infection caused by C. gattii sensu lato, molecular and antifungal susceptibility profile of this pathogen. Cases diagnosed to have CNS cryptococcosis were included in the study. Cryptococcus recovered from patient's specimen was identified by standard protocol. Species confirmation, mating type and molecular type determination were performed by PCR based methods. Antifungal susceptibility was tested in VITEK2C to amphotericin B, 5-flucytosine, fluconazole and voriconazole. Among 199 cases, 20 (10%) were due to C. gattii, comprising of 75% cryptococcal meningitis and 25% cryptococcoma cases. Young adult males were commonly affected. Headache and vomiting were prominent symptoms and 50% were immunocompromised. Among the isolates, 75%, 20% and 5% were C. tetragattii, C. gattii sensu stricto and C. bacillisporus respectively and all had mating type α. Four (20%) isolates of C. tetragattii and the only isolate of C. bacillisporus were resistant to fluconazole. The most common species isolated from south India is C. tetragattii. The study contributes to the epidemiology of C. gattii and reiterates the need for genotyping and antifungal susceptibility testing. © 2017 Blackwell Verlag GmbH.

Preoperative biliary colonization/infection caused by multidrug-resistant (MDR) pathogens in patients undergoing major hepatectomy with extrahepatic bile duct resection.

PubMed

Sugawara, Gen; Yokoyama, Yukihiro; Ebata, Tomoki; Igami, Tsuyoshi; Yamaguchi, Junpei; Mizuno, Takashi; Yagi, Tetsuya; Nagino, Masato

2018-05-01

The aim of this study was to review the surgical outcomes of patients who underwent major hepatectomy with extrahepatic bile duct resection after preoperative biliary drainage with a particular focus on the impact of preoperative biliary colonization/infection caused by multidrug-resistant pathogens. Medical records of patients who underwent hepatobiliary resection after preoperative external biliary drainage between 2001 and 2015 were reviewed retrospectively. Prophylactic antibiotics were selected according to the results of drug susceptibility tests of surveillance bile cultures. In total, 565 patients underwent surgical resection. Based on the results of bile cultures, the patients were classified into three groups: group A, patients with negative bile cultures (n = 113); group B, patients with positive bile cultures without multidrug-resistant pathogen growth (n = 416); and group C, patients with multidrug-resistant pathogen-positive bile culture (n = 36). The incidence of organ/space surgical site infection, bacteremia, median duration of postoperative hospital stay, and the mortality rate did not differ among the three groups. The incidence of incisional surgical site infection and infectious complications caused by multidrug-resistant pathogens was significantly higher in group C than in groups A and B. Fifty-two patients had postoperative infectious complications caused by multidrug-resistant pathogens. Multivariate analysis identified preoperative multidrug-resistant pathogen-positive bile culture as a significant independent risk factor for postoperative infectious complications caused by multidrug-resistant pathogens (P< .001). Major hepatectomy with extrahepatic bile duct resection after biliary drainage can be performed with acceptable rates of morbidity and mortality using appropriate antibiotic prophylaxis, even in patients with biliary colonization/infection caused by multidrug-resistant pathogens. Copyright © 2018 Elsevier Inc. All rights reserved.

[Prevalence and features of pathogenic bacteria in the department of hematology without bone marrow transplantation in Peking Union Medical College Hospital from 2010 to 2012].

PubMed

Wnag, Lu; Yang, Chen; Zhang, Qian; Han, Bing; Zhuang, Jun-jing; Chen, Miao; Zou, Nong; Li, Jian; Duan, Ming-hui; Zhang, Wei; Zhu, Tie-nan; Xu, Ying; Wang, Shu-jie; Zhou, Dao-bin; Zhao, Yong-qiang; Zhang, Hui; Wang, Peng; Xu, Ying-chun

2014-08-01

To investigate the incidence, pathogens, and clinical features of infection in consecutive cases from 2010 to 2012 in Peking Union Medical College Hospital. The incidence, pathogen, treatment, and outcomes of patients with hematological diseases who had positive findings of bacterium in their samples from 2010 to 2012 were retrospectively analyzed. There were 449 positive samples (5.8%) from 4 890 patients during this period, among which 388 were proved to be with pathogenic bacteria. Samples separated from patients with community-aquired infections accounted for 8.4% of all positive samples. Most community-aquired infections were caused by Gram-negative bacteria (75%), although no multidrug-resistant bacteria was observed. Samples separated from patients with nosocomial infections accounted for 91.6% of all positive samples. Respiratory tract (49.4%) and peripheral blood (32.6%) were the most common samples with positive results. Skin soft tissues (10.4%), and urine (3.7%) were less common samples. Most of the pathogenic bacteria of the nosocomial infections were Gram-negative (66.9%). The most common Gram-negative bacteria included Escherichia coli (13.8%), Pseudomonas aeruginosa (12.1%), and Klebsiella pneumonia (12.1%), while Staphylococcus aureus (10.4%), Enterococcus faecium (7.0%), and Staphylococcus epidermidis (5.1%) were the most common Gram-positive bacteria. Gram-negative bacteria consisted of most of sputum samples and peripheral blood samples. Samples from the surface of skin wound and anal swab were composed largely by Gram-positive bacteria (63.8%). The detection rates of extended-spectrum beta-lactamase-producing Klebsiella pneumonia/Klebsiella oxytoca, Escherichia coli, and Proteus mirabilis were 24.0%, 87.9% and 38.4%, respectively. The resistance to Acinetobacter baumannii was serious. Multidrug-resistant, extensive drug resistant and pan drug resistant A. baumannii acountted for 74% of all A. Baumannii infections. Stenotrophomonas maltophilia showed low resistance to sulfamethoxazole/trimethoprim, levofloxacin and minocycline. Also, 22 methicillin-resistant Staphylococcus aureus and 9 methicillin-resistant Staphylococcus Epidermidis were detected, which were only sensitive to vancomycin, teicoplanin, and linezolid. All patients were treated in the haematology wards and most of them were under agranulocytosis or immunosuppression. Finally, 22 patients reached clinical recovery through anti-infective therapy, whereas 49 patients died. Among those deaths, 42 patients attributed to severe infections and infection-associated complications. Fourteen of all the deaths might be infected with drug-resistance bacteria. There were 61 samples proved to be bacteria colonization. Nonfermenters such as Acinetobacter baumannii and Stenotrophomonas maltophilia made up for a large amount of bacteria colonization. The pathogens of nosocomial infections in the hematology ward are mainly Gram-negative bacteria. The incidences and pathogens vary from different infection sites. Nosocomial infection still has a higher mortality rate. Once nonfermenters are detected positive, the pathogenic or colonial bacteria should be distinguished.

The prevalence and distribution of indicators of fecal contamination in the sand from beaches of Oran coast

NASA Astrophysics Data System (ADS)

Messaoui, N.; Matallah-Boutiba, A.; Boutiba, Z.

2017-02-01

The microbiological quality of water at public bathing beaches is regularly monitored using fecal indicator bacteria (FIB) as a surrogate for the presence of human sewage and pathogens. The common feature of all these routine screening procedures is that the primary analysis is for indicator organisms rather than the pathogens that might cause concern. Indicator organisms are bacteria such as non-specific coliforms, Escherichia coli and Pseudomonas aeruginosa that are very commonly found in the human or animal gut and which, if detected, may suggest the presence of sewage. Indicator organisms are used because even when a person is infected with more pathogenic bacteria, they will still be excreting many millions times more indicator organisms than pathogens. It is therefore reasonable to surmise that if indicator organism levels are low, then pathogen levels will be very much lower or absent. Judgments as to suitability of water for use are based on very extensive precedents and relate to the probability of any sample population of bacteria being able to be infective at a reasonable statistical level of confidence. Exposure to FIB and associated pathogens may also occur through contact with contaminated beach sand, but no standards limiting levels of microbes in sand or required monitoring program has been established. As a result, the factors affecting FIB and pathogen survival/persistence in sand remain largely unstudied. A possible contamination of the sand by bacterial communities could be a source of transmission of certain pathogenic bacteria. The goal of this study was to look for a presence of certain bacteria that could be a source of illness to swimmers and compare the different levels of contamination between beach sand and sea water in four sites along the Western Oranian coast. First analysis were made during the dry season and rainy season from December 2010 to June 2012 to estimate fecal coliforms, Pseudomonas spp and total germs levels. E.coli and Enterococcus.ssp levels were estimated from September 2012 to June 2015. Highest levels of bacterial flora were detected in dry sand beach in impacted locations for almost all the period of studies. PCR or molecular biology techniques can be used in order to show the presence of pathogenic strains of E. coli like E.coli O157:H7.

Surveillance for foodborne disease outbreaks - United States, 1998-2008.

PubMed

Gould, L Hannah; Walsh, Kelly A; Vieira, Antonio R; Herman, Karen; Williams, Ian T; Hall, Aron J; Cole, Dana

2013-06-28

Foodborne diseases cause an estimated 48 million illnesses each year in the United States, including 9.4 million caused by known pathogens. Foodborne disease outbreak surveillance provides valuable insights into the agents and foods that cause illness and the settings in which transmission occurs. CDC maintains a surveillance program for collection and periodic reporting of data on the occurrence and causes of foodborne disease outbreaks in the United States. This surveillance system is the primary source of national data describing the numbers of illnesses, hospitalizations, and deaths; etiologic agents; implicated foods; contributing factors; and settings of food preparation and consumption associated with recognized foodborne disease outbreaks in the United States. 1998-2008. The Foodborne Disease Outbreak Surveillance System collects data on foodborne disease outbreaks, defined as the occurrence of two or more cases of a similar illness resulting from the ingestion of a common food. Public health agencies in all 50 states, the District of Columbia, U.S. territories, and Freely Associated States have primary responsibility for identifying and investigating outbreaks and use a standard form to report outbreaks voluntarily to CDC. During 1998-2008, reporting was made through the electronic Foodborne Outbreak Reporting System (eFORS). During 1998-2008, CDC received reports of 13,405 foodborne disease outbreaks, which resulted in 273,120 reported cases of illness, 9,109 hospitalizations, and 200 deaths. Of the 7,998 outbreaks with a known etiology, 3,633 (45%) were caused by viruses, 3,613 (45%) were caused by bacteria, 685 (5%) were caused by chemical and toxic agents, and 67 (1%) were caused by parasites. Among the 7,724 (58%) outbreaks with an implicated food or contaminated ingredient reported, 3,264 (42%) could be assigned to one of 17 predefined commodity categories: fish, crustaceans, mollusks, dairy, eggs, beef, game, pork, poultry, grains/beans, oils/sugars, fruits/nuts, fungi, leafy vegetables, root vegetables, sprouts, and vegetables from a vine or stalk. The commodities implicated most commonly were poultry (18.9%; 95% confidence interval [CI] = 17.4-20.3) and fish (18.6%; CI = 17.2-20), followed by beef (11.9%; CI = 10.8-13.1). The pathogen-commodity pairs most commonly responsible for outbreaks were scombroid toxin/histamine and fish (317 outbreaks), ciguatoxin and fish (172 outbreaks), Salmonella and poultry (145 outbreaks), and norovirus and leafy vegetables (141 outbreaks). The pathogen-commodity pairs most commonly responsible for outbreak-related illnesses were norovirus and leafy vegetables (4,011 illnesses), Clostridium perfringens and poultry (3,452 illnesses), Salmonella and vine-stalk vegetables (3,216 illnesses), and Clostridium perfringens and beef (2,963 illnesses). Compared with the first 2 years of the study (1998-1999), the percentage of outbreaks associated with leafy vegetables and dairy increased substantially during 2006-2008, while the percentage of outbreaks associated with eggs decreased. Outbreak reporting rates and implicated foods varied by state and year, respectively; analysis of surveillance data for this 11-year period provides important information regarding changes in sources of illness over time. A substantial percentage of foodborne disease outbreaks were associated with poultry, fish, and beef, whereas many outbreak-related illnesses were associated with poultry, leafy vegetables, beef, and fruits/nuts. The percentage of outbreaks associated with leafy vegetables and dairy increased during the surveillance period, while the percentage associated with eggs decreased. Outbreak surveillance data highlight the etiologic agents, foods, and settings involved most often in foodborne disease outbreaks and can help to identify food commodities and preparation settings in which interventions might be most effective. Analysis of data collected over several years of surveillance provides a means to assess changes in the food commodities associated most frequently with outbreaks that might occur following improvements in food safety or changes in consumption patterns or food preparation practices. Prevention of foodborne disease depends on targeted interventions at appropriate points from food production to food preparation. Efforts to reduce foodborne illness should focus on the pathogens and food commodities causing the most outbreaks and outbreak-associated illnesses, including beef, poultry, fish, and produce.

The genome sequence of the emerging common midwife toad virus identifies an evolutionary intermediate within ranaviruses.

PubMed

Mavian, Carla; López-Bueno, Alberto; Balseiro, Ana; Casais, Rosa; Alcamí, Antonio; Alejo, Alí

2012-04-01

Worldwide amphibian population declines have been ascribed to global warming, increasing pollution levels, and other factors directly related to human activities. These factors may additionally be favoring the emergence of novel pathogens. In this report, we have determined the complete genome sequence of the emerging common midwife toad ranavirus (CMTV), which has caused fatal disease in several amphibian species across Europe. Phylogenetic and gene content analyses of the first complete genomic sequence from a ranavirus isolated in Europe show that CMTV is an amphibian-like ranavirus (ALRV). However, the CMTV genome structure is novel and represents an intermediate evolutionary stage between the two previously described ALRV groups. We find that CMTV clusters with several other ranaviruses isolated from different hosts and locations which might also be included in this novel ranavirus group. This work sheds light on the phylogenetic relationships within this complex group of emerging, disease-causing viruses.

Transmission of Enterobacter aerogenes septicemia in healthcare workers.

PubMed

Jha, Piyush; Kim, Choon-Mee; Kim, Dong-Min; Chung, Jong-Hoon; Yoon, Na-Ra; Jha, Babita; Kim, Seok Won; Jang, Sook Jin; Ahn, Young-Joon; Chung, Jae Keun; Jeon, Doo Young

2016-01-01

Enterobacter aerogenes is recognized as an important bacterial pathogen in hospital-acquired infections. This report describes two unusual cases of septicemia caused by E. aerogenes in immunocompetent healthcare workers. E. aerogenes was isolated from blood cultures of the two patients experiencing septicemia. The clinical isolates were initially identified as E. aerogenes using a VITEK II automated system and 16S rRNA sequence analysis, and; both isolates involved in the outbreak shared a common pulse-field gel electrophoresis pattern. The similarities between the two cases included the simultaneous development of gastroenteritis symptoms, severe sepsis and thrombocytopenia after taking intravenous injections of ketorolac tromethamine. A common source of normal saline, a 100 mL bottle, was used for diluting the analgesic in both cases. In addition to the general population, healthcare workers, especially those who are also intravenous drug abusers, should be considered subjects that could cause a transmission of Enterobacter infection.

Association of genotypes with infection types and antifungal susceptibilities in Candida albicans as revealed by recent molecular typing strategies

PubMed Central

Bai, Feng-Yan

2014-01-01

Candida albicans is a commensal microorganism in the mucosa of healthy individuals, but is also the most common opportunistic fungal pathogen of humans. It causes from benign infections such as oral and vaginal candidiasis to fatal, systematic diseases in immunocompromised or critically ill patients. In addition to improved therapy, the rapid and accurate identification of the disease-causing strains is crucial for diagnosis, clinical treatment and epidemiological studies of candidiasis. A variety of methods for strain typing of C. albicans have been developed. The most commonly used methods with the focus on recently developed molecular typing or DNA-fingerprinting strategies and the recent findings in the association of specific and genetically similar genotypes with certain infection types and the correlation between azole susceptibilities and certain genotypes of C. albicans from China are reviewed. PMID:24772369

How recent advances in molecular tests could impact the diagnosis of pneumonia.

PubMed

Murdoch, David R

2016-01-01

Molecular diagnostic tests have been the single major development in pneumonia diagnostics over recent years. Nucleic acid detection tests (NATs) have greatly improved the ability to detect respiratory viruses and bacterial pathogens that do not normally colonize the respiratory tract. In contrast, NATs do not yet have an established role for diagnosing pneumonia caused by bacteria that commonly colonize the nasopharynx due to difficulties discriminating between pathogens and coincidental carriage strains. New approaches are needed to distinguish infection from colonization, such as through use of quantitative methods and identification of discriminating cut-off levels. The recent realization that the lung microbiome exists has provided new insights into the pathogenesis of pneumonia involving the interaction between multiple microorganisms. New developments in molecular diagnostics must account for this new paradigm.

A review on detection methods used for foodborne pathogens

PubMed Central

Priyanka, B.; Patil, Rajashekhar K.; Dwarakanath, Sulatha

2016-01-01

Foodborne pathogens have been a cause of a large number of diseases worldwide and more so in developing countries. This has a major economic impact. It is important to contain them, and to do so, early detection is very crucial. Detection and diagnostics relied on culture-based methods to begin with and have developed in the recent past parallel to the developments towards immunological methods such as enzyme-linked immunosorbent assays (ELISA) and molecular biology-based methods such as polymerase chain reaction (PCR). The aim has always been to find a rapid, sensitive, specific and cost-effective method. Ranging from culturing of microbes to the futuristic biosensor technology, the methods have had this common goal. This review summarizes the recent trends and brings together methods that have been developed over the years. PMID:28139531

Healthcare-associated Pneumonia: Clinical Features and Retrospective Analysis Over 10 Years

PubMed Central

Qi, Fei; Zhang, Guo-Xin; She, Dan-Yang; Liang, Zhi-Xin; Wang, Ren-Tao; Yang, Zhen; Chen, Liang-An; Cui, Jun-Chang

2015-01-01

Background: Healthcare-associated pneumonia (HCAP) is associated with drug-resistant pathogens and high mortality, and there is no clear evidence that this is due to inappropriate antibiotic therapy. This study was to elucidate the clinical features, pathogens, therapy, and outcomes of HCAP, and to clarify the risk factors for drug-resistant pathogens and prognosis. Methods: Retrospective observational study among hospitalized patients with HCAP over 10 years. The primary outcome was 30-day all-cause hospital mortality after admission. Demographics (age, gender, clinical features, and comorbidities), dates of admission, discharge and/or death, hospitalization costs, microbiological results, chest imaging studies, and CURB-65 were analyzed. Antibiotics, admission to Intensive Care Unit (ICU), mechanical ventilation, and pneumonia prognosis were recorded. Patients were dichotomized based on CURB-65 (low- vs. high-risk). Results: Among 612 patients (mean age of 70.7 years), 88.4% had at least one comorbidity. Commonly detected pathogens were Acinetobacter baumannii, Pseudomonas aeruginosa, and coagulase-negative staphylococci. Initial monotherapy with β-lactam antibiotics was the most common initial therapy (50%). Mean age, length of stay, hospitalization expenses, ICU admission, mechanical ventilation use, malignancies, and detection rate for P. aeruginosa, and Staphylococcus aureus were higher in the high-risk group compared with the low-risk group. CURB-65 ≥3, malignancies, and mechanical ventilation were associated with an increased mortality. Logistic regression analysis showed that cerebrovascular diseases and being bedridden were independent risk factors for HCAP. Conclusion: Initial treatment of HCAP with broad-spectrum antibiotics could be an appropriate approach. CURB-65 ≥3, malignancies, and mechanical ventilation may result in an increased mortality. PMID:26481734

A Framework to Reduce Infectious Disease Risk from Urban Poultry in the United States

PubMed Central

Tobin, Molly R.; Goldshear, Jesse L.; Price, Lance B.; Graham, Jay P.

2015-01-01

Objectives Backyard poultry ownership is increasingly common in U.S. cities and is regulated at the local level. Human contact with live poultry is a well-known risk for infection with zoonotic pathogens, notably Salmonella, yet the ability of local jurisdictions to reduce the risk of infectious disease transmission from poultry to humans is unstudied. We reviewed urban poultry ordinances in the United States and reported Salmonella outbreaks from backyard poultry to identify regulatory gaps in preventing zoonotic pathogen transmission. Based on this analysis, we propose regulatory guidelines for U.S. cities to reduce infectious disease risk from backyard poultry ownership. Methods We assessed local ordinances in the 150 most populous U.S. jurisdictions for content related to noncommercial poultry ownership using online resources and communications with government officials. We also performed a literature review using publicly available data sources to identify human infectious disease outbreaks caused by contact with backyard poultry. Results Of the cities reviewed, 93% (n=139) permit poultry in some capacity. Most urban poultry ordinances share common characteristics focused on reducing nuisance to neighbors. Ordinances do not address many pathways of transmission relevant to poultry-to-human transmission of pathogens, such as manure management. Conclusions To reduce the risk of pathogen exposure from backyard poultry, urban ordinances should incorporate the following seven components: limited flock size, composting of manure in sealed containers, prohibition of slaughter, required veterinary care to sick birds, appropriate disposal of dead birds, annual permits linked to consumer education, and a registry of poultry owners. PMID:26346104

Healthcare-associated Pneumonia: Clinical Features and Retrospective Analysis Over 10 Years.

PubMed

Qi, Fei; Zhang, Guo-Xin; She, Dan-Yang; Liang, Zhi-Xin; Wang, Ren-Tao; Yang, Zhen; Chen, Liang-An; Cui, Jun-Chang

2015-10-20

Healthcare-associated pneumonia (HCAP) is associated with drug-resistant pathogens and high mortality, and there is no clear evidence that this is due to inappropriate antibiotic therapy. This study was to elucidate the clinical features, pathogens, therapy, and outcomes of HCAP, and to clarify the risk factors for drug-resistant pathogens and prognosis. Retrospective observational study among hospitalized patients with HCAP over 10 years. The primary outcome was 30-day all-cause hospital mortality after admission. Demographics (age, gender, clinical features, and comorbidities), dates of admission, discharge and/or death, hospitalization costs, microbiological results, chest imaging studies, and CURB-65 were analyzed. Antibiotics, admission to Intensive Care Unit (ICU), mechanical ventilation, and pneumonia prognosis were recorded. Patients were dichotomized based on CURB-65 (low- vs. high-risk). Among 612 patients (mean age of 70.7 years), 88.4% had at least one comorbidity. Commonly detected pathogens were Acinetobacter baumannii, Pseudomonas aeruginosa, and coagulase-negative staphylococci. Initial monotherapy with β-lactam antibiotics was the most common initial therapy (50%). Mean age, length of stay, hospitalization expenses, ICU admission, mechanical ventilation use, malignancies, and detection rate for P. aeruginosa, and Staphylococcus aureus were higher in the high-risk group compared with the low-risk group. CURB-65 ≥3, malignancies, and mechanical ventilation were associated with an increased mortality. Logistic regression analysis showed that cerebrovascular diseases and being bedridden were independent risk factors for HCAP. Initial treatment of HCAP with broad-spectrum antibiotics could be an appropriate approach. CURB-65 ≥3, malignancies, and mechanical ventilation may result in an increased mortality.

Review of Non-Bacterial Infections in Respiratory Medicine: Viral Pneumonia.

PubMed

Galván, José María; Rajas, Olga; Aspa, Javier

2015-11-01

Although bacteria are the main pathogens involved in community-acquired pneumonia, a significant number of community-acquired pneumonia are caused by viruses, either directly or as part of a co-infection. The clinical picture of these different pneumonias can be very similar, but viral infection is more common in the pediatric and geriatric populations, leukocytes are not generally elevated, fever is variable, and upper respiratory tract symptoms often occur; procalcitonin levels are not generally affected. For years, the diagnosis of viral pneumonia was based on cell culture and antigen detection, but since the introduction of polymerase chain reaction techniques in the clinical setting, identification of these pathogens has increased and new microorganisms such as human bocavirus have been discovered. In general, influenza virus type A and syncytial respiratory virus are still the main pathogens involved in this entity. However, in recent years, outbreaks of deadly coronavirus and zoonotic influenza virus have demonstrated the need for constant alert in the face of new emerging pathogens. Neuraminidase inhibitors for viral pneumonia have been shown to reduce transmission in cases of exposure and to improve the clinical progress of patients in intensive care; their use in common infections is not recommended. Ribavirin has been used in children with syncytial respiratory virus, and in immunosuppressed subjects. Apart from these drugs, no antiviral has been shown to be effective. Prevention with anti-influenza virus vaccination and with monoclonal antibodies, in the case of syncytial respiratory virus, may reduce the incidence of pneumonia. Copyright © 2014 SEPAR. Published by Elsevier Espana. All rights reserved.

Modeling the intracellular pathogen-immune interaction with cure rate

NASA Astrophysics Data System (ADS)

Dubey, Balram; Dubey, Preeti; Dubey, Uma S.

2016-09-01

Many common and emergent infectious diseases like Influenza, SARS, Hepatitis, Ebola etc. are caused by viral pathogens. These infections can be controlled or prevented by understanding the dynamics of pathogen-immune interaction in vivo. In this paper, interaction of pathogens with uninfected and infected cells in presence or absence of immune response are considered in four different cases. In the first case, the model considers the saturated nonlinear infection rate and linear cure rate without absorption of pathogens into uninfected cells and without immune response. The next model considers the effect of absorption of pathogens into uninfected cells while all other terms are same as in the first case. The third model incorporates innate immune response, humoral immune response and Cytotoxic T lymphocytes (CTL) mediated immune response with cure rate and without absorption of pathogens into uninfected cells. The last model is an extension of the third model in which the effect of absorption of pathogens into uninfected cells has been considered. Positivity and boundedness of solutions are established to ensure the well-posedness of the problem. It has been found that all the four models have two equilibria, namely, pathogen-free equilibrium point and pathogen-present equilibrium point. In each case, stability analysis of each equilibrium point is investigated. Pathogen-free equilibrium is globally asymptotically stable when basic reproduction number is less or equal to unity. This implies that control or prevention of infection is independent of initial concentration of uninfected cells, infected cells, pathogens and immune responses in the body. The proposed models show that introduction of immune response and cure rate strongly affects the stability behavior of the system. Further, on computing basic reproduction number, it has been found to be minimum for the fourth model vis-a-vis other models. The analytical findings of each model have been exemplified by numerical simulations.

Experimental infection of bats with Geomyces destructans causes white-nose syndrome

USGS Publications Warehouse

Lorch, J.M.; Meteyer, C.U.; Behr, M.J.; Boyles, J.G.; Cryan, P.M.; Hicks, A.C.; Ballmann, A.E.; Coleman, J.T.H.; Redell, D.N.; Reeder, D.M.; Blehert, D.S.

2011-01-01

White-nose syndrome (WNS) has caused recent catastrophic declines among multiple species of bats in eastern North America. The disease's name derives from a visually apparent white growth of the newly discovered fungus Geomyces destructans on the skin (including the muzzle) of hibernating bats. Colonization of skin by this fungus is associated with characteristic cutaneous lesions that are the only consistent pathological finding related to WNS. However, the role of G. destructans in WNS remains controversial because evidence to implicate the fungus as the primary cause of this disease is lacking. The debate is fuelled, in part, by the assumption that fungal infections in mammals are most commonly associated with immune system dysfunction. Additionally, the recent discovery that G. destructans commonly colonizes the skin of bats of Europe, where no unusual bat mortality events have been reported, has generated further speculation that the fungus is an opportunistic pathogen and that other unidentified factors are the primary cause of WNS. Here we demonstrate that exposure of healthy little brown bats (Myotis lucifugus) to pure cultures of G. destructans causes WNS. Live G. destructans was subsequently cultured from diseased bats, successfully fulfilling established criteria for the determination of G. destructans as a primary pathogen. We also confirmed that WNS can be transmitted from infected bats to healthy bats through direct contact. Our results provide the first direct evidence that G. destructans is the causal agent of WNS and that the recent emergence of WNS in North America may represent translocation of the fungus to a region with a naive population of animals. Demonstration of causality is an instrumental step in elucidating the pathogenesis and epidemiology of WNS and in guiding management actions to preserve bat populations against the novel threat posed by this devastating infectious disease. ?? 2011 Macmillan Publishers Limited. All rights reserved.

A Case Report of Penile Infection Caused by Fluconazole- and Terbinafine-Resistant Candida albicans.

PubMed

Hu, Yongxuan; Hu, Yanqing; Lu, Yan; Huang, Shiyun; Liu, Kangxing; Han, Xue; Mao, Zuhao; Wu, Zhong; Zhou, Xianyi

2017-04-01

Candida albicans is the most common pathogen that causes balanoposthitis. It often causes recurrence of symptoms probably due to its antifungal resistance. A significant number of balanitis Candida albicans isolates are resistant to azole and terbinafine antifungal agents in vitro. However, balanoposthitis caused by fluconazole- and terbinafine-resistant Candida albicans has rarely been reported. Here, we describe a case of a recurrent penile infection caused by fluconazole- and terbinafine-resistant Candida albicans, as well as the treatments administered to this patient. The isolate from the patient was tested for drug susceptibility in vitro. It was sensitive to itraconazole, voriconazole, clotrimazole and amphotericin B, but not to terbinafine and fluconazole. Thus, oral itraconazole was administrated to this patient with resistant Candida albicans penile infection. The symptoms were improved, and mycological examination result was negative. Follow-up treatment of this patient for 3 months showed no recurrence.

Antimicrobial peptides in marine invertebrate health and disease

PubMed Central

Destoumieux-Garzón, Delphine; Rosa, Rafael Diego; Schmitt, Paulina; Barreto, Cairé; Vidal-Dupiol, Jeremie; Mitta, Guillaume; Gueguen, Yannick; Bachère, Evelyne

2016-01-01

Aquaculture contributes more than one-third of the animal protein from marine sources worldwide. A significant proportion of aquaculture products are derived from marine protostomes that are commonly referred to as ‘marine invertebrates’. Among them, penaeid shrimp (Ecdysozosoa, Arthropoda) and bivalve molluscs (Lophotrochozoa, Mollusca) are economically important. Mass rearing of arthropods and molluscs causes problems with pathogens in aquatic ecosystems that are exploited by humans. Remarkably, species of corals (Cnidaria) living in non-exploited ecosystems also suffer from devastating infectious diseases that display intriguing similarities with those affecting farmed animals. Infectious diseases affecting wild and farmed animals that are present in marine environments are predicted to increase in the future. This paper summarizes the role of the main pathogens and their interaction with host immunity, with a specific focus on antimicrobial peptides (AMPs) and pathogen resistance against AMPs. We provide a detailed review of penaeid shrimp AMPs and their role at the interface between the host and its resident/pathogenic microbiota. We also briefly describe the relevance of marine invertebrate AMPs in an applied context. This article is part of the themed issue ‘Evolutionary ecology of arthropod antimicrobial peptides’. PMID:27160602

Microbial Inhibition of Fusarium Pathogens and Biological Modification of Trichothecenes in Cereal Grains

PubMed Central

Wachowska, Urszula; Packa, Danuta

2017-01-01

Fungi of the genus Fusarium infect cereal crops during the growing season and cause head blight and other diseases. Their toxic secondary metabolites (mycotoxins) contaminate grains. Several dozen toxic compounds produced by fungal pathogens have been identified to date. Type B trichothecenes—deoxynivalenol, its acetyl derivatives and nivalenol (produced mainly by F. graminearum and F. culmorum)—are most commonly detected in cereal grains. “T-2 toxin” (produced by, among others, F. sporotrichioides) belongs to type-A trichothecenes which are more toxic than other trichothecenes. Antagonistic bacteria and fungi can affect pathogens of the genus Fusarium via different modes of action: direct (mycoparasitism or hyperparasitism), mixed-path (antibiotic secretion, production of lytic enzymes) and indirect (induction of host defense responses). Microbial modification of trichothecenes involves acetylation, deacetylation, oxidation, de-epoxidation, and epimerization, and it lowers the pathogenic potential of fungi of the genus Fusarium. Other modifing mechanisms described in the paper involve the physical adsorption of mycotoxins in bacterial cells and the conjugation of mycotoxins to glucose and other compounds in plant and fungal cells. The development of several patents supports the commercialization and wider application of microorganisms biodegrading mycotoxins in grains and, consequently, in feed additives. PMID:29261142

Identification of urinary tract pathogens after 3-hours urine culture by MALDI-TOF mass spectrometry.

PubMed

Haiko, Johanna; Savolainen, Laura E; Hilla, Risto; Pätäri-Sampo, Anu

2016-10-01

Complicated urinary tract infections, such as pyelonephritis, may lead to sepsis. Rapid diagnosis is needed to identify the causative urinary pathogen and to verify the appropriate empirical antimicrobial therapy. We describe here a rapid identification method for urinary pathogens: urine is incubated on chocolate agar for 3h at 35°C with 5% CO2 and subjected to MALDI-TOF MS analysis by VITEK MS. Overall 207 screened clinical urine samples were tested in parallel with conventional urine culture. The method, called U-si-MALDI-TOF (urine short incubation MALDI-TOF), showed correct identification for 86% of Gram-negative urinary tract pathogens (Escherichia coli, Klebsiella pneumoniae, and other Enterobacteriaceae), when present at >10(5)cfu/ml in culture (n=107), compared with conventional culture method. However, Gram-positive bacteria (n=28) were not successfully identified by U-si-MALDI-TOF. This method is especially suitable for rapid identification of E. coli, the most common cause of urinary tract infections and urosepsis. Turnaround time for identification using U-si-MALDI-TOF compared with conventional urine culture was improved from 24h to 4-6h. Copyright © 2016 Elsevier B.V. All rights reserved.

Evolution of amoxicillin/clavulanate in the treatment of adults with acute bacterial rhinosinusitis and community-acquired pneumonia in response to antimicrobial-resistance patterns.

PubMed

File, Thomas M; Benninger, Michael S; Jacobs, Michael R

2004-06-01

Current treatment guidelines for community-acquired respiratory tract infections no longer depend solely on the characteristics of the patient and the clinical syndrome, but on those of the offending pathogen, including presence and level of antimicrobial resistance. The most common respiratory tract pathogens known to cause acute bacterial rhinosinusitis (ABRS) and community-acquired pneumonia (CAP) include Streptococcus pneumoniae and Haemophilus influenzae. The prevalence of antimicrobial resistance, especially b-lactum and macrolide resistance, among S pneumoniae and H influenzae has increased dramatically during the past 2 decades, diminishing the activity of many older antimicrobials against resistant organisms. A pharmacokinetically enhanced formulation of amoxicillin/clavulanate has been developed to fulfill the need for an oral b-lactam antimicrobial that achieves a greater time that the serum drug concentration exceeds the minimum inhibitory concentration (T > MIC) of antimicrobials against pathogens than conventional formulations to improve activity against S pneumoniae with reduced susceptibility to penicillin. The b-lactamase inhibitor clavulanate allows for coverage of b-lactamase-producing pathogens, such as H influenzae and M catarrhalis. This article reviews the rationale for, and evolution of, oral amoxicillin clavulanate for ABRS and CAP

Antimicrobial peptides in marine invertebrate health and disease.

PubMed

Destoumieux-Garzón, Delphine; Rosa, Rafael Diego; Schmitt, Paulina; Barreto, Cairé; Vidal-Dupiol, Jeremie; Mitta, Guillaume; Gueguen, Yannick; Bachère, Evelyne

2016-05-26

Aquaculture contributes more than one-third of the animal protein from marine sources worldwide. A significant proportion of aquaculture products are derived from marine protostomes that are commonly referred to as 'marine invertebrates'. Among them, penaeid shrimp (Ecdysozosoa, Arthropoda) and bivalve molluscs (Lophotrochozoa, Mollusca) are economically important. Mass rearing of arthropods and molluscs causes problems with pathogens in aquatic ecosystems that are exploited by humans. Remarkably, species of corals (Cnidaria) living in non-exploited ecosystems also suffer from devastating infectious diseases that display intriguing similarities with those affecting farmed animals. Infectious diseases affecting wild and farmed animals that are present in marine environments are predicted to increase in the future. This paper summarizes the role of the main pathogens and their interaction with host immunity, with a specific focus on antimicrobial peptides (AMPs) and pathogen resistance against AMPs. We provide a detailed review of penaeid shrimp AMPs and their role at the interface between the host and its resident/pathogenic microbiota. We also briefly describe the relevance of marine invertebrate AMPs in an applied context.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'. © 2016 The Author(s).

Temporal and spatial scaling of the genetic structure of a vector-borne plant pathogen.

PubMed

Coletta-Filho, Helvécio D; Francisco, Carolina S; Almeida, Rodrigo P P

2014-02-01

The ecology of plant pathogens of perennial crops is affected by the long-lived nature of their immobile hosts. In addition, changes to the genetic structure of pathogen populations may affect disease epidemiology and management practices; examples include local adaptation of more fit genotypes or introduction of novel genotypes from geographically distant areas via human movement of infected plant material or insect vectors. We studied the genetic structure of Xylella fastidiosa populations causing disease in sweet orange plants in Brazil at multiple scales using fast-evolving molecular markers (simple-sequence DNA repeats). Results show that populations of X. fastidiosa were regionally isolated, and that isolation was maintained for populations analyzed a decade apart from each other. However, despite such geographic isolation, local populations present in year 2000 were largely replaced by novel genotypes in 2009 but not as a result of migration. At a smaller spatial scale (individual trees), results suggest that isolates within plants originated from a shared common ancestor. In summary, new insights on the ecology of this economically important plant pathogen were obtained by sampling populations at different spatial scales and two different time points.

II. Pathogens

Treesearch

Ned B. Klopfenstein; Brian W. Geils

2011-01-01

Invasive fungal pathogens have caused immeasurably large ecological and economic damage to forests. It is well known that invasive fungal pathogens can cause devastating forest diseases (e.g., white pine blister rust, chestnut blight, Dutch elm disease, dogwood anthracnose, butternut canker, Scleroderris canker of pines, sudden oak death, pine pitch canker) (Maloy 1997...

Marker-Assisted Molecular Profiling, Deletion Mutant Analysis, and RNA-Seq Reveal a Disease Resistance Cluster Associated with Uromyces appendiculatus Infection in Common Bean Phaseolus vulgaris L.

PubMed

Todd, Antonette R; Donofrio, Nicole; Sripathi, Venkateswara R; McClean, Phillip E; Lee, Rian K; Pastor-Corrales, Marcial; Kalavacharla, Venu Kal

2017-05-23

Common bean ( Phaseolus vulgaris L.) is an important legume, useful for its high protein and dietary fiber. The fungal pathogen Uromyces appendiculatus (Pers.) Unger can cause major loss in susceptible varieties of the common bean. The Ur-3 locus provides race specific resistance to virulent strains or races of the bean rust pathogen along with Crg , (Complements resistance gene), which is required for Ur-3 -mediated rust resistance. In this study, we inoculated two common bean genotypes (resistant "Sierra" and susceptible crg) with rust race 53 of U. appendiculatus , isolated leaf RNA at specific time points, and sequenced their transcriptomes. First, molecular markers were used to locate and identify a 250 kb deletion on chromosome 10 in mutant crg (which carries a deletion at the Crg locus). Next, we identified differential expression of several disease resistance genes between Mock Inoculated (MI) and Inoculated (I) samples of "Sierra" leaf RNA within the 250 kb delineated region. Both marker assisted molecular profiling and RNA-seq were used to identify possible transcriptomic locations of interest regarding the resistance in the common bean to race 53. Identification of differential expression among samples in disease resistance clusters in the bean genome may elucidate significant genes underlying rust resistance. Along with preserving favorable traits in the crop, the current research may also aid in global sustainability of food stocks necessary for many populations.

Marker-Assisted Molecular Profiling, Deletion Mutant Analysis, and RNA-Seq Reveal a Disease Resistance Cluster Associated with Uromyces appendiculatus Infection in Common Bean Phaseolus vulgaris L.

PubMed Central

Todd, Antonette R.; Donofrio, Nicole; Sripathi, Venkateswara R.; McClean, Phillip E.; Lee, Rian K.; Pastor-Corrales, Marcial; Kalavacharla, Venu (Kal)

2017-01-01

Common bean (Phaseolus vulgaris L.) is an important legume, useful for its high protein and dietary fiber. The fungal pathogen Uromyces appendiculatus (Pers.) Unger can cause major loss in susceptible varieties of the common bean. The Ur-3 locus provides race specific resistance to virulent strains or races of the bean rust pathogen along with Crg, (Complements resistance gene), which is required for Ur-3-mediated rust resistance. In this study, we inoculated two common bean genotypes (resistant “Sierra” and susceptible crg) with rust race 53 of U. appendiculatus, isolated leaf RNA at specific time points, and sequenced their transcriptomes. First, molecular markers were used to locate and identify a 250 kb deletion on chromosome 10 in mutant crg (which carries a deletion at the Crg locus). Next, we identified differential expression of several disease resistance genes between Mock Inoculated (MI) and Inoculated (I) samples of “Sierra” leaf RNA within the 250 kb delineated region. Both marker assisted molecular profiling and RNA-seq were used to identify possible transcriptomic locations of interest regarding the resistance in the common bean to race 53. Identification of differential expression among samples in disease resistance clusters in the bean genome may elucidate significant genes underlying rust resistance. Along with preserving favorable traits in the crop, the current research may also aid in global sustainability of food stocks necessary for many populations. PMID:28545258

Zebrafish and Streptococcal Infections.

PubMed

Saralahti, A; Rämet, M

2015-09-01

Streptococcal bacteria are a versatile group of gram-positive bacteria capable of infecting several host organisms, including humans and fish. Streptococcal species are common colonizers of the human respiratory and gastrointestinal tract, but they also cause some of the most common life-threatening, invasive infections in humans and aquaculture. With its unique characteristics and efficient tools for genetic and imaging applications, the zebrafish (Danio rerio) has emerged as a powerful vertebrate model for infectious diseases. Several zebrafish models introduced so far have shown that zebrafish are suitable models for both zoonotic and human-specific infections. Recently, several zebrafish models mimicking human streptococcal infections have also been developed. These models show great potential in providing novel information about the pathogenic mechanisms and host responses associated with human streptococcal infections. Here, we review the zebrafish infection models for the most relevant streptococcal species: the human-specific Streptococcus pneumoniae and Streptococcus pyogenes, and the zoonotic Streptococcus iniae and Streptococcus agalactiae. The recent success and the future potential of these models for the study of host-pathogen interactions in streptococcal infections are also discussed. © 2015 The Foundation for the Scandinavian Journal of Immunology.

Dysregulation of Innate Lymphoid Cells in Common Variable Immunodeficiency.

PubMed

Maglione, Paul J; Cols, Montserrat; Cunningham-Rundles, Charlotte

2017-10-05

Common variable immunodeficiency (CVID) is the most prevalent symptomatic primary immune deficiency. With widespread use of immunoglobulin replacement therapy, non-infectious complications, such as autoimmunity, chronic intestinal inflammation, and lung disease, have replaced infections as the major cause of morbidity and mortality in this immune deficiency. The pathogenic mechanisms that underlie the development of these complications in CVID are not known; however, there have been numerous associated laboratory findings. Among the most intriguing of these associations is elevation of interferon signature genes in CVID patients with inflammatory/autoimmune complications, as a similar gene expression profile is found in systemic lupus erythematosus and other chronic inflammatory diseases. Linked with this heightened interferon signature in CVID is an expansion of circulating IFN-γ-producing innate lymphoid cells. Innate lymphoid cells are key regulators of both protective and pathogenic immune responses that have been extensively studied in recent years. Further exploration of innate lymphoid cell biology in CVID may uncover key mechanisms underlying the development of inflammatory complications in these patients and may inspire much needed novel therapeutic approaches.

[Spontaneous bacterial peritonitis].

PubMed

Velkey, Bálint; Vitális, Eszter; Vitális, Zsuzsanna

2017-01-01

Spontaneous bacterial peritonitis occurs most commonly in cirrhotic patients with ascites. Pathogens get into the circulation by intestinal translocation and colonize in peritoneal fluid. Diagnosis of spontaneous bacterial peritonitis is based on elevated polymorphonuclear leukocyte count in the ascites (>0,25 G/L). Ascites culture is often negative but aids to get information about antibiotic sensitivity in positive cases. Treatment in stable patient can be intravenous then orally administrated ciprofloxacin or amoxicillin/clavulanic acid, while in severe cases intravenous III. generation cephalosporin. Nosocomial spontaneous bacterial peritonitis often caused by Gram-positive bacteria and multi-resistant pathogens can also be expected thus carbapenem should be the choice of the empiric treatment. Antibiotic prophylaxis should be considered. Norfloxacin is used most commonly, but changes are expected due to increase in quinolone resistance. As a primary prophylaxis, a short-term antibiotic treatment is recommended after gastrointestinal bleeding for 5 days, while long-term prophylaxis is for patients with low ascites protein, and advanced disease (400 mg/day). Secondary prophylaxis is recommended for all patients recovered from spontaneous bacterial peritonitis. Due to increasing antibiotic use of antibiotics prophylaxis is debated to some degree. Orv. Hetil., 2017, 158(2), 50-57.

Ranid Herpesvirus 3 and Proliferative Dermatitis in Free-Ranging Wild Common Frogs (Rana Temporaria).

PubMed

Origgi, F C; Schmidt, B R; Lohmann, P; Otten, P; Akdesir, E; Gaschen, V; Aguilar-Bultet, L; Wahli, T; Sattler, U; Stoffel, M H

2017-07-01

Amphibian pathogens are of current interest as contributors to the global decline of amphibians. However, compared with chytrid fungi and ranaviruses, herpesviruses have received relatively little attention. Two ranid herpesviruses have been described: namely, Ranid herpesvirus 1 (RHV1) and Ranid herpesvirus 2 (RHV2). This article describes the discovery and partial characterization of a novel virus tentatively named Ranid herpesvirus 3 (RHV3), a candidate member of the genus Batrachovirus in the family Alloherpesviridae. RHV3 infection in wild common frogs (Rana temporaria) was associated with severe multifocal epidermal hyperplasia, dermal edema, a minor inflammatory response, and variable mucous gland degeneration. Intranuclear inclusions were numerous in the affected epidermis together with unique extracellular aggregates of herpesvirus-like particles. The RHV3-associated skin disease has features similar to those of a condition recognized in European frogs for the last 20 years and whose cause has remained elusive. The genome of RHV3 shares most of the features of the Alloherpesviruses. The characterization of this presumptive pathogen may be of value for amphibian conservation and for a better understanding of the biology of Alloherpesviruses.

Laboratory monitoring of bacterial gastroenteric pathogens Salmonella and Shigella in Shanghai, China 2006-2012.

PubMed

Zhang, J; Wang, F; Jin, H; Hu, J; Yuan, Z; Shi, W; Yang, X; Meng, J; Xu, X

2015-02-01

In 2006 we initiated an enhanced laboratory-based surveillance of Salmonella and Shigella infections in Shanghai, China. A total of 4483 Salmonella and 2226 Shigella isolates were recovered from stool specimens by 2012. In 80 identified Salmonella serovars, Enteritidis (34·5%) and Typhimurium (26·2%) were the most common. Shigella (S.) sonnei accounted for 63·9% of human Shigella infections over the same time period, and replaced S. flexneri to become the primary cause of shigellosis since 2010. Overall, a high level of antimicrobial resistance was observed in Salmonella and Shigella, particularly to nalidixic acid, ampicillin, and tetracycline. Ciprofloxacin resistance was common in Salmonella Typhimurium (21·0%) and S. flexneri (37·6%). The cephalosporin resistance in both pathogens also increased over the years, ranging from 3·4% to 7·0% in Salmonella, and from 10·4% to 28·6% in Shigella. Resistance to multiple antimicrobials was also identified in a large number of the isolates. This study provides insight into the distribution of Salmonella and Shigella in diarrhoeal diseases.

Dysregulation of Innate Lymphoid Cells in Common Variable Immunodeficiency

PubMed Central

Maglione, Paul J.; Cols, Montserrat

2018-01-01

Common variable immunodeficiency (CVID) is the most prevalent symptomatic primary immune deficiency. With widespread use of immunoglobulin replacement therapy, non-infectious complications, such as autoimmunity, chronic intestinal inflammation, and lung disease, have replaced infections as the major cause of morbidity and mortality in this immune deficiency. The pathogenic mechanisms that underlie the development of these complications in CVID are not known; however, there have been numerous associated laboratory findings. Among the most intriguing of these associations is elevation of interferon signature genes in CVID patients with inflammatory/autoimmune complications, as a similar gene expression profile is found in systemic lupus erythematosus and other chronic inflammatory diseases. Linked with this heightened interferon signature in CVID is an expansion of circulating IFN-γ-producing innate lymphoid cells. Innate lymphoid cells are key regulators of both protective and pathogenic immune responses that have been extensively studied in recent years. Further exploration of innate lymphoid cell biology in CVID may uncover key mechanisms underlying the development of inflammatory complications in these patients and may inspire much needed novel therapeutic approaches. PMID:28983810

Type-IVC Secretion System: A Novel Subclass of Type IV Secretion System (T4SS) Common Existing in Gram-Positive Genus Streptococcus

PubMed Central

Chen, Chen; Gao, George F.

2012-01-01

A growing number of pathogens are being found to possess specialized secretion systems which they use in various ways to subvert host defenses. Type IV secretion system (T4SS) is one of versatile secretion systems essential for the virulence and even survival of some bacteria species, and they enable the secretion of protein and DNA substrates across the cell envelope. T4SS was once believed to be present only in Gram-negative bacteria. In this study, we present evidence of a new subclass of T4SS, Type-IVC secretion system and indicate its common existence in the Gram-positive bacterial genus Streptococcus. We further identified that VirB1, VirB4, VirB6 and VirD4 are the minimal key components of this system. Using genome comparisons and evolutionary relationship analysis, we proposed that Type-IVC secretion system is movable via transposon factors and mediates the conjugative transfer of DNA, enhances bacterial pathogenicity, and could cause large-scale outbreaks of infections in humans. PMID:23056296

"Stormy waters ahead": global emergence of carbapenemases.

PubMed

Patel, Gopi; Bonomo, Robert A

2013-01-01

Carbapenems, once considered the last line of defense against of serious infections with Enterobacteriaceae, are threatened with extinction. The increasing isolation of carbapenem-resistant Gram-negative pathogens is forcing practitioners to rely on uncertain alternatives. As little as 5 years ago, reports of carbapenem resistance in Enterobacteriaceae, common causes of both community and healthcare-associated infections, were sporadic and primarily limited to case reports, tertiary care centers, intensive care units, and outbreak settings. Carbapenem resistance mediated by β-lactamases, or carbapenemases, has become widespread and with the paucity of reliable antimicrobials available or in development, international focus has shifted to early detection and infection control. However, as reports of Klebsiella pneumoniae carbapenemases, New Delhi metallo-β-lactamase-1, and more recently OXA-48 (oxacillinase-48) become more common and with the conveniences of travel, the assumption that infections with highly resistant Gram-negative pathogens are limited to the infirmed and the heavily antibiotic and healthcare exposed are quickly being dispelled. Herein, we provide a status report describing the increasing challenges clinicians are facing and forecast the "stormy waters" ahead.

“Stormy waters ahead”: global emergence of carbapenemases

PubMed Central

Patel, Gopi; Bonomo, Robert A.

2013-01-01

Carbapenems, once considered the last line of defense against of serious infections with Enterobacteriaceae, are threatened with extinction. The increasing isolation of carbapenem-resistant Gram-negative pathogens is forcing practitioners to rely on uncertain alternatives. As little as 5 years ago, reports of carbapenem resistance in Enterobacteriaceae, common causes of both community and healthcare-associated infections, were sporadic and primarily limited to case reports, tertiary care centers, intensive care units, and outbreak settings. Carbapenem resistance mediated by β-lactamases, or carbapenemases, has become widespread and with the paucity of reliable antimicrobials available or in development, international focus has shifted to early detection and infection control. However, as reports of Klebsiella pneumoniae carbapenemases, New Delhi metallo-β-lactamase-1, and more recently OXA-48 (oxacillinase-48) become more common and with the conveniences of travel, the assumption that infections with highly resistant Gram-negative pathogens are limited to the infirmed and the heavily antibiotic and healthcare exposed are quickly being dispelled. Herein, we provide a status report describing the increasing challenges clinicians are facing and forecast the “stormy waters” ahead. PMID:23504089

Antimicrobial Activity of Seven Essential Oils From Iranian Aromatic Plants Against Common Causes of Oral Infections

PubMed Central

Zomorodian, Kamiar; Ghadiri, Pooria; Saharkhiz, Mohammad Jamal; Moein, Mohammad Reza; Mehriar, Peiman; Bahrani, Farideh; Golzar, Tahereh; Pakshir, Keyvan; Fani, Mohammad Mehdi

2015-01-01

Background: Over the past two decades, there has been a growing trend in using oral hygienic products originating from natural resources such as essential oils (EOs) and plant extracts. Seven aromatic plants used in this study are among popular traditional Iranian medicinal plants with potential application in modern medicine as anti-oral infectious diseases. Objectives: This study was conducted to determine the chemical composition and antimicrobial activities of essential oils from seven medicinal plants against pathogens causing oral infections. Materials and Methods: The chemical compositions of EOs distilled from seven plants were analyzed by gas chromatography/mass spectrometry (GC/MS). These plants included Satureja khuzestanica, S. bachtiarica, Ocimum sanctum, Artemisia sieberi, Zataria multiflora, Carum copticum and Oliveria decumbens. The antimicrobial activity of the essential oils was evaluated by broth micro-dilution in 96 well plates as recommended by the Clinical and Laboratory Standards Institute (CLSI) methods. Results: The tested EOs inhibited the growth of examined oral pathogens at concentrations of 0.015-16 µL/mL. Among the examined oral pathogens, Enterococcus faecalis had the highest Minimum Inhibitory Concentrations (MICs) and Minimum Microbicidal Concentrations (MMCs). Of the examined EOs, S. khuzestanica, Z. multiflora and S. bachtiarica, showed the highest antimicrobial activities, respectively, while Artemisia sieberi exhibited the lowest antimicrobial activity. Conclusions: The excellent antimicrobial activities of the tested EOs might be due to their major phenolic or alcoholic monoterpenes with known antimicrobial activities. Hence, these EOs can be possibly used as an antimicrobial agent in treatment and control of oral pathogens. PMID:25793100

[Clinical analysis for patients with continuous ambulatory peritoneal dialysis associated peritonitis].

PubMed

Liu, Jian; Huang, Xun; Liu, Yao; Xu, Hui; Gong, Rui'e; Li, Chunhui

2016-12-28

To analyze the clinical characteristics of continuous ambulatory peritoneal dialysis (CAPD) associated peritonitis in the tertiary hospitals and to discuss the preventive and therapeutic strategy.
 Methods: The clinical characteristics, pathogens, resistance and outcomes of 126 CAPD associated peritonitis in 104 patients from Jan, 2013 to June, 2016, were retrospectively analyzed.
 Results: Among the patients, the incidence rates of abdominal pain, fever, diarrhea and emesis were 104 (82.54%), 56 (44.44%), 49 (38.89%), and 31 (23.60%), respectively. Among them, 88 patients suffered peritonitis once, other 16 patients suffered multiple peritonitis or recurrent peritonitis for 38 times. Among the 38 times, the numbers for recurrent, repeated or catheter-associated peritonitis were 2, 2, or 3, respectively. Peritoneal fluids from 103 cases were cultured, and 64 cases were positive in bacteria, with a rate of 62.14%. A total of 70 strains of bacteria were separated, including 42 strains of gram-positive bacteria, 21 strains of gram-negative bacteria, and 7 strains of fungus. The most common gram-positive pathogens were Staphylococcus epidermidis, Enterococcus faecalis and Staphylococcus haemolyticus, while Escherichia coli, Klebsiella pneumoniae and Klebsiella pneumoniae were the most common gram-negative bacteria. Candida albicans was the major fungal pathogens. Gram-positive cocci showed resistance to gentamycin, levofloxacin, moxifloxacin, vancomycin and linezolid, with a rate at 20.00%, 36.11%, 5%, 0%, and 0%, respectively. The gram-negative bacilli were resistent to cefoperazone/sulbactam, gentamycin, cephazolin, and ceftazidime, with a rate at 6.25%, 10.53%, 64.29%, and 15.38%, respectively. There were no imipenem, amikacin, piperacillin/tazobactam-resistant strains were found.
 Conclusion: The most common pathogen causing CAPD associated peritonitis is gram-positive bacteria. It is crucial to take the anti-infection therapy for CAPD associated peritonitis early. The positive rates for bacterial culture need to be enhanced through improvement of methods. At the same time, doctors could improve the outcome of CAPD associated peritonitis by adjusting the medication according to the drug sensitivity results.

Prevalence of vaginitis in different age groups among females in Greece.

PubMed

Sianou, Argiri; Galyfos, George; Moragianni, Dimitra; Baka, Stavroula

2017-08-01

Patients with vaginitis were classified into four groups: Group A (prepubertal under-aged females); Group B (pubertal under-aged females); Group C (reproductive age adult females); Group D (postmenopausal adult females). All vaginal specimens underwent microscopy, amine testing, Gram staining and culturing. Overall, 163 patients were included (33, 14, 81 and 35 patients, respectively). The most common infection was bacterial vaginosis (BV), followed by Ureaplasma infection, aerobic vaginitis (AV) and candidiasis. The most common AV-associated organism was Escherichia coli and the most common BV-associated organism was Gardnerella vaginalis. AV was more frequent in Group A, BV in Group C and Ureaplasma infections in Groups C/D. Decreased lactobacilli concentrations were associated with BV in fertile patients (Groups B-C). Although presentation of vaginitis is similar among females of different age in Greece, type and prevalence of pathogens differ. Normal vaginal flora changes are associated with higher risk of vaginitis in specific age groups. Impact Statement The worldwide incidence of reproductive tract infections has been increasing, with specific pathogens being associated with significant risk of morbidity and complications. However, literature data on the distribution of such infections in different age groups is limited. Therefore, the aim of this study was to provide data on the prevalence and causes of vaginitis in adult and non-adult females of all ages. This study has shown that although presentation of vaginitis is similar among females of different age groups and menstrual status in Greece, type and prevalence of responsible pathogens are different among groups. Changes in normal vaginal flora seem to be associated with higher risk of vaginitis in specific age-groups as well. These findings could contribute in adjusting diagnostic and therapeutic strategies for each age group according to the prevailing pathogens. Further research on antibiotic resistance and treatment outcomes for each age group should be conducted.

Rain-induced ejection of pathogens from leaves: revisiting the hypothesis of splash-on-film using high-speed visualization.

PubMed

Gilet, Tristan; Bourouiba, Lydia

2014-12-01

Plant diseases are a major cause of losses of crops worldwide. Although rainfalls and foliar disease outbreaks are correlated, the detailed mechanism explaining their link remains poorly understood. The common assumption from phytopathology for such link is that a splash is generated upon impact of raindrops on contaminated liquid films coating sick leaves. We examine this assumption using direct high-speed visualizations of the interactions of raindrops and leaves over a range of plants. We show that films are seldom found on the surface of common leaves. We quantify the leaf-surface's wetting properties, showing that sessile droplets instead of films are predominant on the surfaces of leaves. We find that the presence of sessile drops rather than that of films has important implications when coupled with the compliance of a leaf: it leads to a new physical picture consisting of two dominant rain-induced mechanisms of ejection of pathogens. The first involves a direct interaction between the fluids of the raindrop and the sessile drops via an off-centered splash. The second involves the indirect action of the raindrop that leads to the inertial detachment of the sessile drop via the leaf's motion imparted by the impact of the raindrop. Both mechanisms are distinct from the commonly assumed scenario of splash-on-film in terms of outcome: they result in different fragmentation processes induced by surface tension, and, thus, different size-distributions of droplets ejected. This is the first time that modern direct high-speed visualizations of impacts on leaves are used to examine rain-induced ejection of pathogens at the level of a leaf and identify the inertial detachment and off-center splash ejections as alternatives to the classically assumed splash-on-film ejections of foliar pathogens. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Extreme sensitivity to ultraviolet light in the fungal pathogen causing white-nose syndrome of bats

Treesearch

Jonathan M. Palmer; Kevin P. Drees; Jeffrey T. Foster; Daniel L. Lindner

2018-01-01

Bat white-nose syndrome (WNS), caused by the fungal pathogen Pseudogymnoascus destructans, has decimated North American hibernating bats since its emergence in 2006. Here, we utilize comparative genomics to examine the evolutionary history of this pathogen in comparison to six closely related nonpathogenic species....

Potential Use of Dimethyl Sulfoxide in Treatment of Infections Caused by Pseudomonas aeruginosa

PubMed Central

Guo, Qiao; Wu, Qiaolian; Bai, Dangdang; Liu, Yang; Chen, Lin; Jin, Sheng; Wu, Yuting

2016-01-01

Dimethyl sulfoxide (DMSO) is commonly used as a solvent to dissolve water-insoluble drugs or other test samples in both in vivo and in vitro experiments. It was observed during our experiment that DMSO at noninhibitory concentrations could significantly inhibit pyocyanin production in the human pathogen Pseudomonas aeruginosa. Pyocyanin is an important pathogenic factor whose production is controlled by a cell density-dependent quorum-sensing (QS) system. Investigation of the effect of DMSO on QS showed that DMSO has significant QS antagonistic activities and concentrations of DMSO in the micromolar range attenuated a battery of QS-controlled virulence factors, including rhamnolipid, elastase, and LasA protease production and biofilm formation. Further study indicated that DMSO inhibition of biofilm formation and pyocyanin production was attained by reducing the level of production of an autoinducer molecule of the rhl QS system, N-butanoyl-l-homoserine lactone (C4-HSL). In a mouse model of a burn wound infection with P. aeruginosa, treatment with DMSO significantly decreased mouse mortality compared with that for mice in the control group. The capacity of DMSO to attenuate the pathogenicity of P. aeruginosa points to the potential use of DMSO as an antipathogenic agent for the treatment of P. aeruginosa infection. As a commonly used solvent, however, DMSO's impact on bacterial virulence calls for cautionary attention in its usage in biological, medicinal, and clinical studies. PMID:27645245

Escherichia coli and urinary tract infections: the role of poultry-meat.

PubMed

Manges, A R

2016-02-01

Extraintestinal pathogenic Escherichia coli (ExPEC) is the most common cause of community-acquired and hospital-acquired extraintestinal infections. The hypothesis that human ExPEC may have a food animal reservoir has been a topic of investigation by multiple groups around the world. Experimental studies showing the shared pathogenic potential of human ExPEC and avian pathogenic E. coli suggest that these extraintestinal E. coli may be derived from the same bacterial lineages or share common evolutionary roots. The consistent observation of specific human ExPEC lineages in poultry or poultry products, and rarely in other meat commodities, supports the hypothesis that there may be a poultry reservoir for human ExPEC. The time lag between human ExPEC acquisition (in the intestine) and infection is the fundamental challenge facing studies attempting to attribute ExPEC transmission to poultry or other environmental sources. Even whole genome sequencing efforts to address attribution will struggle with defining meaningful genetic relationships outside of a discrete food-borne outbreak setting. However, if even a fraction of all human ExPEC infections, especially antimicrobial-resistant ExPEC infections, is attributable to the introduction of multidrug-resistant ExPEC lineages through contaminated food product(s), the relevance to public health, food animal production and food safety will be significant. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Comparative experimental subcutaneous glanders and melioidosis in the common marmoset (Callithrix jacchus)

PubMed Central

Nelson, Michelle; Salguero, Francisco J; Dean, Rachel E; Ngugi, Sarah A; Smither, Sophie J; Atkins, Timothy P; Lever, Mark S

2014-01-01

Glanders and melioidosis are caused by two distinct Burkholderia species and have generally been considered to have similar disease progression. While both of these pathogens are HHS/CDC Tier 1 agents, natural infection with both these pathogens is primarily through skin inoculation. The common marmoset (Callithrix jacchus) was used to compare disease following experimental subcutaneous challenge. Acute, lethal disease was observed in marmosets following challenge with between 26 and 1.2 × 108 cfu Burkholderia pseudomallei within 22–85 h. The reproducibility and progression of the disease were assessed following a challenge of 1 × 102 cfu of B. pseudomallei. Melioidosis was characterised by high levels of bacteraemia, focal microgranuloma progressing to non-necrotic multifocal solid lesions in the livers and spleens and multi-organ failure. Lethal disease was observed in 93% of animals challenged with Burkholderia mallei, occurring between 5 and 10.6 days. Following challenge with 1 × 102 cfu of B. mallei, glanders was characterised with lymphatic spread of the bacteria and non-necrotic, multifocal solid lesions progressing to a multifocal lesion with severe necrosis and pneumonia. The experimental results confirmed that the disease pathology and presentation is strikingly different between the two pathogens. The marmoset provides a model of the human syndrome for both diseases facilitating the development of medical countermeasures. PMID:25477002

Amoxicillin/clavulanate potassium extended release tablets: a new antimicrobial for the treatment of acute bacterial sinusitis and community-acquired pneumonia.

PubMed

Benninger, Michael S

2003-10-01

Community-acquired bacterial respiratory tract infections are among the most common health disorders requiring medical care and are associated with substantial morbidity, mortality, and direct and indirect costs. Recent increases in the prevalence of antimicrobial resistance have resulted in reduced susceptibility of the most common respiratory tract bacterial pathogens to a number of antimicrobials. Amoxicillin/clavulanate potassium extended release (ER) tablets (Augmentin XR, GlaxoSmithKline) is a new formulation of amoxicillin/clavulanate that retains activity against betalactamase-producing organisms whilst increasing the activity against Streptococcus pneumoniae through elevated and sustained plasma amoxicillin concentrations. The bilayer tablet provides immediate release of clavulanate and both immediate and sustained release of amoxicillin to maintain therapeutic concentrations of amoxicillin over longer periods of the dosing interval. In clinical trials of acute bacterial sinusitis (ABS) and community-acquired pneumonia (CAP), amoxicillin/clavulanate ER was shown to have excellent bacteriological and clinical success rates, even in patients infected with antimicrobial-resistant pathogens, and was found to be generally well tolerated. Amoxicillin/clavulanate ER is approved in the US for the treatment of patients with ABS or CAP caused by beta-lactamase-producing pathogens (ie, Haemophilus influenzae, Moraxella catarrhalis, Haemophilus parainfluenzae, Klebsiella pneumoniae, or methicillin-susceptible Staphylococcus aureus) and S. pneumoniae with reduced susceptibility to penicillin (penicillin minimum inhibitory concentration = 2.0 microg/ml).

Targeting agr- and agr-Like Quorum Sensing Systems for Development of Common Therapeutics to Treat Multiple Gram-Positive Bacterial Infections

PubMed Central

Gray, Brian; Hall, Pamela; Gresham, Hattie

2013-01-01

Invasive infection by the Gram-positive pathogen Staphylococcus aureus is controlled by a four gene operon, agr that encodes a quorum sensing system for the regulation of virulence. While agr has been well studied in S. aureus, the contribution of agr homologues and analogues in other Gram-positive pathogens is just beginning to be understood. Intriguingly, other significant human pathogens, including Clostridium perfringens, Listeria monocytogenes, and Enterococcus faecalis contain agr or analogues linked to virulence. Moreover, other significant human Gram-positive pathogens use peptide based quorum sensing systems to establish or maintain infection. The potential for commonality in aspects of these signaling systems across different species raises the prospect of identifying therapeutics that could target multiple pathogens. Here, we review the status of research into these agr homologues, analogues, and other peptide based quorum sensing systems in Gram-positive pathogens as well as the potential for identifying common pathways and signaling mechanisms for therapeutic discovery. PMID:23598501

An Egyptian HPAI H5N1 isolate from clade 2.2.1.2 is highly pathogenic in an experimentally infected domestic duck breed (Sudani duck).

PubMed

Samir, M; Hamed, M; Abdallah, F; Kinh Nguyen, V; Hernandez-Vargas, E A; Seehusen, F; Baumgärtner, W; Hussein, A; Ali, A A H; Pessler, F

2018-06-01

The highly pathogenic avian influenza (HPAI) H5N1 viruses continue to cause major problems in poultry and can, although rarely, cause human infection. Being enzootic in domestic poultry, Egyptian isolates are continuously evolving, and novel clades vary in their pathogenicity in avian hosts. Considering the importance of domestic ducks as natural hosts of HPAI H5N1 viruses and their likelihood of physical contact with other avian hosts and humans, it is of utmost importance to characterize the pathogenicity of newly emerged HPAI strains in the domestic duck. The most recently identified Egyptian clade 2.2.1.2 HPAI H5N1 viruses have been isolated from naturally infected pigeons, turkeys and humans. However, essentially nothing is known about their pathogenicity in domestic ducks. We therefore characterized the pathogenicity of an Egyptian HPAI H5N1 isolate A/chicken/Faquos/amn12/2011 (clade 2.2.1.2) in Sudani duck, a domestic duck breed commonly reared in Egypt. While viral transcription (HA mRNA) was highest in lung, heart and kidney peaking between 40 and 48 hpi, lower levels were detected in brain. Weight loss of infected ducks started at 16 hpi and persisted until 120 hpi. The first severe clinical signs were noted by 32 hpi and peaked in severity at 72 and 96 hpi. Haematological analyses showed a decline in total leucocytes, granulocytes, platelets and granulocyte/lymphocyte ratio, but lymphocytosis. Upon necropsy, lesions were obvious in heart, liver, spleen and pancreas and consisted mainly of necrosis and petechial haemorrhage. Histologically, lungs were the most severely affected organs, whereas brain only showed mild neuronal degeneration and gliosis at 48 hpi despite obvious neurological clinical signs. Taken together, our results provide first evidence that this HPAI H5N1 isolate (clade 2.2.1.2) is highly pathogenic to Sudani ducks and highlight the importance of this breed as potential reservoir and disseminator of HPAI strains from this clade. © 2018 Blackwell Verlag GmbH.

Diarrheal outbreak caused by atypical enteropathogenic Escherichia coli O157:H45 in South Korea.

PubMed

Park, Ji-Hyuk; Oh, Sung-Suk; Oh, Kyung-Hwan; Shin, Jaeseung; Jang, Eun Jung; Jun, Byung-Yool; Youn, Seung-Ki; Cho, Seung-Hak

2014-10-01

Background: In May 2013, an outbreak of gastroenteritis occurred in a high school in Incheon, South Korea. We investigated the outbreak in order to identify the pathogen and mode of transmission. A case-control study was performed using standardized questionnaires with a case definition of illness with diarrhea. Stool samples, environmental samples, and samples from preserved food items were collected to test pathogens. Pulsed-field gel electrophoresis (PFGE) was performed on the outbreak-related Escherichia coli strains. Thirty-three people (attack rate: 2.5%) met the case definition, and the pattern of the epidemic curve suggested a point-source outbreak. The common symptoms of cases were diarrhea (100.0%), abdominal pain (75.8%), chills (45.5%), and nausea (39.4%). Cases were found to be 8.26 times more likely to have eaten spicy fish soup with cod (95% confidence interval: 1.05-65.01). Consumption of egg soup with spring onions or braised eggs with razor clam flesh was significantly associated with illness. Atypical enteropathogenic E. coli O157:H45 was isolated from samples of 9 cases (27.3%) and tuna bibimbap. PFGE patterns of all tested isolates of O157 serotype were indistinguishable. This outbreak was caused by atypical enteropathogenic E. coli O157:H45 and the food vehicle was suspected to be tuna bibimbap. The statistical analysis was not in concordance with the microbiologic tests, probably owing to low pathogenicity of atypical enteropathogenic E. coli O157. This is the first report of an outbreak caused by atypical enteropathogenic E. coli O157.

Evaluation of bovine abortion cases and tissue suitability for identification of infectious agents in California diagnostic laboratory cases from 2007 to 2012.

PubMed

Clothier, K; Anderson, M

2016-03-15

Establishing a definitive cause of bovine abortion is a challenging problem faced by veterinary practitioners and diagnosticians. Detection of an infectious or noninfectious source for abortion may facilitate interventions that mitigate future fetal loss in the herd. The purposes of this study were to identify the most common causes of bovine abortion in cases submitted to the California Animal Health and Food Safety Laboratory System, Davis (CAHFS) from 2007 to 2013 and to determine if detection of infectious pathogens differed with the fetal tissue evaluated. Records of 665 bovine abortion cases of 709 animals were reviewed for pathologic diagnoses, test methods used to identify causative conditions, and which tissues yielded successful identification of infectious agents associated with abortion. Over 58% of abortions were attributed to an infectious cause and 46.9% had an infectious agent identified. The most common infectious conditions were Epizootic Bovine Abortion (EBA) (16.2% of all fetuses), other fetal bacterial infections (14.7% of all fetuses), and Neospora caninum (9.3% of all fetuses.) The bacterium associated with EBA (currently named Pajaroellobacter abortibovis) was most commonly identified by immunohistochemistry (IHC) in lymphoid organs (thymus and spleen); N. caninum IHC was most frequently positive in brain, kidney, and placenta. In cases of pathogenic and opportunistic bacterial infections, abomasal samples yielded a significantly greater proportion of definitive aerobic culture results than lung or liver tissues. Direct fluorescent antibody test results for Bovine Viral Diarrhea Virus testing were identical between lung and kidney tissues and nearly identical (96.0%) for Bovine Herpesvirus I. Noninfectious abortive conditions included fetal stress (10.5%), dystocia (3.9%), congenital defects (3.3%), toxicological or mineral problems (1.8%), and death of the cow (1.1%). Just over 20% of the aborted fetuses had no gross or histopathological lesions to explain the abortion. This review highlights the need for submission of critical samples including abomasal contents, lymphoid tissues (thymus, spleen, and lymph nodes), and brain to maximize the diagnosticians' ability to identify causes of abortion. Copyright © 2016 Elsevier Inc. All rights reserved.

Detection Protocols for West Nile Virus in Mosquitoes, Birds, and Nonhuman Mammals.

PubMed

Kauffman, Elizabeth B; Franke, Mary A; Kramer, Laura D

2016-01-01

West Nile virus is the most widespread mosquito-borne virus in the world, and the most common cause of encephalitis in the USA. Surveillance for this medially important mosquito-borne pathogen is an important part of public health practice. Here we present protocols for testing environmental samples such as mosquitoes, nonvertebrate mammals, and birds for this virus, including RT-PCR, virus isolation in cell culture, and antigenic assays, as well as serologic assays for antibody detection.

Photodynamic therapy in peri-implantitis

NASA Astrophysics Data System (ADS)

Leretter, Marius; Cândea, Adrian; Topala, Florin

2014-01-01

Peri-implantitis is like Damocles sword, threatening over our final results as is the most common cause of implant failure. It is, was and will be one of the most challenging tasks for the practitioner to deal with. The rough implant surface offers the ideal conditions for the pathogenic bacteria to stick and multiply. Even more, the growing mature biofilm is harder to eliminate. Mechanical cleaning and rinsing is not capable to destroy it entirely. Most treatment protocols include strong antibiotics, disregarding their side effects and interactions with other medications.

Diagnosing Medical Parasites: A Public Health Officers Guide to Assisting Laboratory and Medical Officers

DTIC Science & Technology

2009-01-01

an infection usually caused by the pathogenic Entamoeba histolytica / dispar, and is commonly an infection of the colon. It has a world wide...The parasitic adult females lay eggs while they are in the duodenum where they hatch producing rhabditiform (non- infective ) larvae. 1. The... females begin to oviposit 60 to 70 days after infection . Female worms in the cecum shed between 3,000 and 20,000 eggs per day. The life span of the

BSE Case Associated with Prion Protein Gene Mutation

PubMed Central

Richt, Jürgen A.; Hall, S. Mark

2008-01-01

Bovine spongiform encephalopathy (BSE) is a transmissible spongiform encephalopathy (TSE) of cattle and was first detected in 1986 in the United Kingdom. It is the most likely cause of variant Creutzfeldt-Jakob disease (CJD) in humans. The origin of BSE remains an enigma. Here we report an H-type BSE case associated with the novel mutation E211K within the prion protein gene (Prnp). Sequence analysis revealed that the animal with H-type BSE was heterozygous at Prnp nucleotides 631 through 633. An identical pathogenic mutation at the homologous codon position (E200K) in the human Prnp has been described as the most common cause of genetic CJD. This finding represents the first report of a confirmed case of BSE with a potential pathogenic mutation within the bovine Prnp gene. A recent epidemiological study revealed that the K211 allele was not detected in 6062 cattle from commercial beef processing plants and 42 cattle breeds, indicating an extremely low prevalence of the E211K variant (less than 1 in 2000) in cattle. PMID:18787697

Quantifying penetrance in a dominant disease gene using large population control cohorts

PubMed Central

Minikel, Eric Vallabh; Vallabh, Sonia M.; Lek, Monkol; Estrada, Karol; Samocha, Kaitlin E.; Sathirapongsasuti, J. Fah; McLean, Cory Y.; Tung, Joyce Y.; Yu, Linda P.C.; Gambetti, Pierluigi; Blevins, Janis; Zhang, Shulin; Cohen, Yvonne; Chen, Wei; Yamada, Masahito; Hamaguchi, Tsuyoshi; Sanjo, Nobuo; Mizusawa, Hidehiro; Nakamura, Yosikazu; Kitamoto, Tetsuyuki; Collins, Steven J.; Boyd, Alison; Will, Robert G.; Knight, Richard; Ponto, Claudia; Zerr, Inga; Kraus, Theo F.J.; Eigenbrod, Sabina; Giese, Armin; Calero, Miguel; de Pedro-Cuesta, Jesús; Haïk, Stéphane; Laplanche, Jean-Louis; Bouaziz-Amar, Elodie; Brandel, Jean-Philippe; Capellari, Sabina; Parchi, Piero; Poleggi, Anna; Ladogana, Anna; O'Donnell-Luria, Anne H.; Karczewski, Konrad J.; Marshall, Jamie L.; Boehnke, Michael; Laakso, Markku; Mohlke, Karen L.; Kähler, Anna; Chambert, Kimberly; McCarroll, Steven; Sullivan, Patrick F.; Hultman, Christina M.; Purcell, Shaun M.; Sklar, Pamela; van der Lee, Sven J.; Rozemuller, Annemieke; Jansen, Casper; Hofman, Albert; Kraaij, Robert; van Rooij, Jeroen G.J.; Ikram, M. Arfan; Uitterlinden, André G.; van Duijn, Cornelia M.; Daly, Mark J.; MacArthur, Daniel G.

2016-01-01

More than 100,000 genetic variants are reported to cause Mendelian disease in humans, but the penetrance - the probability that a carrier of the purported disease-causing genotype will indeed develop the disease - is generally unknown. Here we assess the impact of variants in the prion protein gene (PRNP) on the risk of prion disease by analyzing 16,025 prion disease cases, 60,706 population control exomes, and 531,575 individuals genotyped by 23andMe, Inc. We show that missense variants in PRNP previously reported to be pathogenic are at least 30× more common in the population than expected based on genetic prion disease prevalence. While some of this excess can be attributed to benign variants falsely assigned as pathogenic, other variants have genuine effects on disease susceptibility but confer lifetime risks ranging from <0.1% to ~100%. We also show that truncating variants in PRNP have position-dependent effects, with true loss-of-function alleles found in healthy older individuals, supporting the safety of therapeutic suppression of prion protein expression. PMID:26791950

[Biological preparations with different mechanism of action for protecting potato against fungal diseases].

PubMed

Kulikov, S N; Alimova, F K; Zakharova, N G; Nemtsev, S V; Varlamov, V P

2006-01-01

Mycological analysis throughout the vegetation period of potato (Solanum tuberosum) made it possible to study in detail the structure of micromycete community, to determine typical dominant (frequency, more than 60%), typical common (frequency, 30 to 60%), typical rare (frequency, 10 to 30%), and casual (frequency, less than 10%) species and to estimate changes in the microorganism community caused by plant protection preparations with different mechanisms of action. It was shown that, as a result of occurrence of resistant forms, synthetic preparations against fungal pathogens of potato (such as TMTD, Ridomil gold MC, and Cupricol) were only slightly more effective than biological preparations (Trichodermin and AgroChit), with the former considerably changing the natural saprophytic mycological community. An increase in the soil pool of Trichoderma harzianum as a result of application of a biological preparation based on this antagonistic fungus correlated with its effectiveness against the soil pathogen Fusarium sp., which causes root rots. A chitosan-based elicitor preparation more effectively suppressed the development of early (Alternaria sp. and Macrosporium sp.) and late (Phytophthora sp.) blights of leaves and had a weaker effect on the soil microflora.

Characterization of Pseudomonas syringae pv. syringae, Causal Agent of Citrus Blast of Mandarin in Montenegro.

PubMed

Ivanović, Žarko; Perović, Tatjana; Popović, Tatjana; Blagojević, Jovana; Trkulja, Nenad; Hrnčić, Snježana

2017-02-01

Citrus blast caused by bacterium Pseudomonas syringae is a very important disease of citrus occuring in many areas of the world, but with few data about genetic structure of the pathogen involved. Considering the above fact, this study reports genetic characterization of 43 P. syringae isolates obtained from plant tissue displaying citrus blast symptoms on mandarin ( Citrus reticulata ) in Montenegro, using multilocus sequence analysis of gyrB , rpoD , and gap1 gene sequences. Gene sequences from a collection of 54 reference pathotype strains of P. syringae from the Plant Associated and Environmental Microbes Database (PAMDB) was used to establish a genetic relationship with our isolates obtained from mandarin. Phylogenetic analyses of gyrB , rpoD , and gap1 gene sequences showed that P. syringae pv. syringae causes citrus blast in mandarin in Montenegro, and belongs to genomospecies 1. Genetic homogeneity of isolates suggested that the Montenegrian population might be clonal which indicates a possible common source of infection. These findings may assist in further epidemiological studies of this pathogen and for determining mandarin breeding strategies for P. syringae control.

Characterization of Pseudomonas syringae pv. syringae, Causal Agent of Citrus Blast of Mandarin in Montenegro

PubMed Central

Ivanović, Žarko; Perović, Tatjana; Popović, Tatjana; Blagojević, Jovana; Trkulja, Nenad; Hrnčić, Snježana

2017-01-01

Citrus blast caused by bacterium Pseudomonas syringae is a very important disease of citrus occuring in many areas of the world, but with few data about genetic structure of the pathogen involved. Considering the above fact, this study reports genetic characterization of 43 P. syringae isolates obtained from plant tissue displaying citrus blast symptoms on mandarin (Citrus reticulata) in Montenegro, using multilocus sequence analysis of gyrB, rpoD, and gap1 gene sequences. Gene sequences from a collection of 54 reference pathotype strains of P. syringae from the Plant Associated and Environmental Microbes Database (PAMDB) was used to establish a genetic relationship with our isolates obtained from mandarin. Phylogenetic analyses of gyrB, rpoD, and gap1 gene sequences showed that P. syringae pv. syringae causes citrus blast in mandarin in Montenegro, and belongs to genomospecies 1. Genetic homogeneity of isolates suggested that the Montenegrian population might be clonal which indicates a possible common source of infection. These findings may assist in further epidemiological studies of this pathogen and for determining mandarin breeding strategies for P. syringae control. PMID:28167885

Filaments in curved streamlines: rapid formation of Staphylococcus aureus biofilm streamers

NASA Astrophysics Data System (ADS)

Kim, Minyoung Kevin; Drescher, Knut; Pak, On Shun; Bassler, Bonnie L.; Stone, Howard A.

2014-06-01

Biofilms are surface-associated conglomerates of bacteria that are highly resistant to antibiotics. These bacterial communities can cause chronic infections in humans by colonizing, for example, medical implants, heart valves, or lungs. Staphylococcus aureus, a notorious human pathogen, causes some of the most common biofilm-related infections. Despite the clinical importance of S. aureus biofilms, it remains mostly unknown how physical effects, in particular flow, and surface structure influence biofilm dynamics. Here we use model microfluidic systems to investigate how environmental factors, such as surface geometry, surface chemistry, and fluid flow affect biofilm development of S. aureus. We discovered that S. aureus rapidly forms flow-induced, filamentous biofilm streamers, and furthermore if surfaces are coated with human blood plasma, streamers appear within minutes and clog the channels more rapidly than if the channels are uncoated. To understand how biofilm streamer filaments reorient in flows with curved streamlines to bridge the distances between corners, we developed a mathematical model based on resistive force theory of slender filaments. Understanding physical aspects of biofilm formation of S. aureus may lead to new approaches for interrupting biofilm formation of this pathogen.

Filaments in curved flow: Rapid formation of Staphylococcus aureus biofilm streamers

NASA Astrophysics Data System (ADS)

Kim, Min Young; Drescher, Knut; Pak, On Shun; Bassler, Bonnie L.; Stone, Howard A.

2014-03-01

Biofilms are surface-associated conglomerates of bacteria that are highly resistant to antibiotics. These bacterial communities can cause chronic infections in humans by colonizing, for example, medical implants, heart valves, or lungs. Staphylococcus aureus, a notorious human pathogen, causes some of the most common biofilm-related infections. Despite the clinical importance of S. aureus biofilms, it remains mostly unknown how physical effects, in particular flow, and surface structure influence biofilm dynamics. Here we use model microfluidic systems to investigate how environmental factors, such as surface geometry, surface chemistry, and fluid flow affect biofilm development in S. aureus.We discovered that S. aureus rapidly forms flow-induced, filamentous biofilm streamers, and furthermore if surfaces are coated with human blood plasma, streamers appear within minutes and clog the channels more rapidly than if the channels are uncoated. To understand how biofilm streamer filaments reorient in curved flow to bridge the distances between corners, we developed a mathematical model based on resistive force theory and slender filaments. Understanding physical aspects of biofilm formation in S. aureus may lead to new approaches for interrupting biofilm formation of this pathogen.

Simulated hatchery system to assess bacteriophage efficacy against Vibrio harveyi.

PubMed

Raghu Patil, J; Desai, Srividya Narayanamurthy; Roy, Panchali; Durgaiah, Murali; Saravanan, R Sanjeev; Vipra, Aradhana

2014-12-02

Vibriosis caused by luminous Vibrio harveyi commonly contributes to poor survival in shrimp hatcheries and aquaculture ponds. Lytic bacteriophages pathogenic for V. harveyi are currently being investigated as an alternative to antibiotics to prevent vibriosis. Here, 8 bacteriophages were isolated from oysters and clams using V. harveyi strains as baiting hosts. Among these bacteriophages, 1 strain (VHP6b) identified as broadly pathogenic for 27 V. harveyi strains examined was further characterized by electron microscopy and genome sequence analysis. Phage VHP6b possessed a tail and morphology consistent with it being a member of the family Siphoviridae, and its genome and proteome were most closely related to the Vibrio phages SSP02 and MAR10. An integrase gene essential for lysogeny was not evident. The ability of bacteriophage VHP6b to protect shrimp postlarvae against vibriosis caused by V. harveyi strain VH6 was demonstrated in a model system designed to simulate typical hatchery conditions. Bacteriophage treatment improved survival of postlarvae by 40 to 60% under these conditions, so therapies based on this or other bacteriophages may be useful in shrimp hatcheries.

Foodborne illness: new developments concerning an old problem.

PubMed

Kasowski, Eric J; Gackstetter, Gary D; Sharp, Trueman W

2002-08-01

Foodborne illnesses continue to cause substantial morbidity and mortality in the United States, primarily as gastroenteritis but occasionally as other syndromes as well. Most of these illnesses are caused by a variety of widely known infectious agents, principally viruses, and are probably the result of common mistakes in food handling in the home or in restaurants. The epidemiology of foodborne illness is evolving. Major changes in food production, distribution, and consumption have created opportunities for new pathogens to emerge and for old ones to reemerge, and the potential for widespread outbreaks is increasing. Antibiotic resistance in bacterial pathogens resulting from the widespread use of antimicrobial agents in animal husbandry is also an important concern. Clinicians must be aware of the changing epidemiology of foodborne illness to recognize and manage these conditions in the clinical setting. In addition, clinicians are critical in the reporting of recognized or suspected foodborne illness, so that public health authorities are able to investigate, understand, and ultimately better control them. A number of new techniques have been employed, and others under development will improve our ability to recognize and cope with foodborne diseases.

Modeling the Lymphocytic Choriomeningitis Virus: Insights into understanding its epidemiology in the wild

NASA Astrophysics Data System (ADS)

Contreras, Christy; McKay, John; Blattman, Joseph; Holechek, Susan

2015-03-01

The lymphocytic choriomenigitis virus (LCMV) is a rodent-spread virus commonly recognized as causing neurological disease that exhibits asymptomatic pathology. The virus is a pathogen normally carried among rodents that can be transmitted to humans by direct or indirect contact with the virus in excretions and secretions from rodents and can cause aseptic meningitis and other conditions in humans. We consider an epidemiological system within rodent populations modeled by a system of ordinary differential equations that captures the dynamics of the diseases transmission and present our findings. The asymptotic nature of the pathogen plays a large role in its spread within a given population, which has motivated us to expand upon an existing SIRC model (Holechek et al in preparation) that accounts for susceptible-, infected-, recovered-, and carrier-mice on the basis of their gender. We are interested in observing and determining the conditions under which the carrier population will reach a disease free equilibrium, and we focus our investigation on the sensitivity of our model to gender, pregnancy related infection, and reproduction rate conditions.

Infective endocarditis in a hemodialysis patient: a dreaded complication.

PubMed

Schubert, Claudia; Moosa, Mohammed R

2007-10-01

Infection is the most common cause of death in hemodialysis patients, after cardiovascular disease. Dialysis access infections, with secondary septicemia, contribute significantly to patient mortality. The most common source is temporary catheterization. Bacteremia occurs commonly in patients receiving hemodialysis, with infective endocarditis being a relatively uncommon, but potentially lethal complication. Valvular calcification is the most significant risk factor. The diagnosis of infective endocarditis is made clinically and confirmed with the echocardiographic modified Duke's criteria. The most common pathogen is Staphylococcus aureus and the mitral valve is the most common site. Staphylococcus aureus infective endocarditis is commonly associated with embolic phenomenon. A high index of suspicion is critical in the early recognition and management of infective endocarditis. However, prevention of bacteremia is undoubtedly the best strategy with the early placement of arteriovenous fistulae. In the case of temporary catheterization, the use of topical mupirocin or polysporin and gentamicin and/or citrate locking is beneficial. Although catheter salvage has not been studied in randomized trials, catheter removal remains standard therapy during bacteremia.

Arboviral Etiologies of Acute Febrile Illnesses in Western South America, 2000–2007

PubMed Central

Forshey, Brett M.; Guevara, Carolina; Laguna-Torres, V. Alberto; Cespedes, Manuel; Vargas, Jorge; Gianella, Alberto; Vallejo, Efrain; Madrid, César; Aguayo, Nicolas; Gotuzzo, Eduardo; Suarez, Victor; Morales, Ana Maria; Beingolea, Luis; Reyes, Nora; Perez, Juan; Negrete, Monica; Rocha, Claudio; Morrison, Amy C.; Russell, Kevin L.; J. Blair, Patrick; Olson, James G.; Kochel, Tadeusz J.

2010-01-01

Background Arthropod-borne viruses (arboviruses) are among the most common agents of human febrile illness worldwide and the most important emerging pathogens, causing multiple notable epidemics of human disease over recent decades. Despite the public health relevance, little is know about the geographic distribution, relative impact, and risk factors for arbovirus infection in many regions of the world. Our objectives were to describe the arboviruses associated with acute undifferentiated febrile illness in participating clinics in four countries in South America and to provide detailed epidemiological analysis of arbovirus infection in Iquitos, Peru, where more extensive monitoring was conducted. Methodology/Findings A clinic-based syndromic surveillance system was implemented in 13 locations in Ecuador, Peru, Bolivia, and Paraguay. Serum samples and demographic information were collected from febrile participants reporting to local health clinics or hospitals. Acute-phase sera were tested for viral infection by immunofluorescence assay or RT-PCR, while acute- and convalescent-phase sera were tested for pathogen-specific IgM by ELISA. Between May 2000 and December 2007, 20,880 participants were included in the study, with evidence for recent arbovirus infection detected for 6,793 (32.5%). Dengue viruses (Flavivirus) were the most common arbovirus infections, totaling 26.0% of febrile episodes, with DENV-3 as the most common serotype. Alphavirus (Venezuelan equine encephalitis virus [VEEV] and Mayaro virus [MAYV]) and Orthobunyavirus (Oropouche virus [OROV], Group C viruses, and Guaroa virus) infections were both observed in approximately 3% of febrile episodes. In Iquitos, risk factors for VEEV and MAYV infection included being male and reporting to a rural (vs urban) clinic. In contrast, OROV infection was similar between sexes and type of clinic. Conclusions/Significance Our data provide a better understanding of the geographic range of arboviruses in South America and highlight the diversity of pathogens in circulation. These arboviruses are currently significant causes of human illness in endemic regions but also have potential for further expansion. Our data provide a basis for analyzing changes in their ecology and epidemiology. PMID:20706628

The impact of hurricanes and flooding disasters on hymenopterid-inflicted injuries.

PubMed

Diaz, James H

2007-01-01

Insect bites and stings, often complicated by allergic reactions or skin infections with community-acquired pathogens, are common sources of morbidity following hurricanes and flooding disasters. The hymenopterids are the most commonly stinging arthropods to cause allergic reactions, and include bees, wasps, and ants. To assess the evolving epidemiology of hymenopterid-inflicted injuries, and the impact of hurricanes and flooding disasters on hymenopterid-inflicted injuries in the United States, an epidemiological analysis of the scientific literature on hymenopterid stings and allergic sting reactions was conducted by MEDLINE search, 1966-2006. The increasing incidence of hymenopterid-inflicted injuries following hurricanes and flooding disasters was described. Common immunological reactions to hymenopterid-inflicted injuries were stratified by clinical severity and outcome. Current recommendations for management, prevention, and prophylaxis of hymenopterid-inflicted injuries were presented. Hymenopterid stings and allergic reactions remain common indications for emergency department visits, especially following hurricanes and flooding disasters. Unrecognized anaphylactic reactions to hymenopterid stings remain significant causes of unanticipated deaths outdoors in young people. Disaster planners and managers are obliged to alert regional healthcare providers of the increased risks of hymenopterid-inflicted injuries following flooding disasters and to assure that emergency drug formularies are properly stocked to treat hymenopterid-inflicted injuries.

Introduction of Non-Native Pollinators Can Lead to Trans-Continental Movement of Bee-Associated Fungi.

PubMed

Hedtke, Shannon M; Blitzer, Eleanor J; Montgomery, Graham A; Danforth, Bryan N

2015-01-01

Bees are essential pollinators for many flowering plants, including agriculturally important crops such as apple. As geographic ranges of bees or their host plants change as a result of human activities, we need to identify pathogens that could be transmitted among newly sympatric species to evaluate and anticipate their effects on bee communities. We used PCR screening and DNA sequencing to evaluate exposure to potentially disease-causing microorganisms in a pollinator of apple, the horned mason bee (Osmia cornifrons). We did not detect microsporidia, Wolbachia, or trypanosomes, which are common pathogens of bees, in any of the hundreds of mason bees screened. We did detect both pathogenic and apathogenic (saprophytic) fungal species in the genus Ascosphaera (chalkbrood), an unidentified species of Aspergillus fungus, and a strain of bacteria in the genus Paenibacillus that is probably apathogenic. We detected pathogenic fungal strains in asymptomatic adult bees that therefore may be carriers of disease. We demonstrate that fungi from the genus Ascosphaera have been transported to North America along with the bee from its native range in Japan, and that O. cornifrons is exposed to fungi previously only identified from nests of other related bee species. Further study will be required to quantify pathogenicity and health effects of these different microbial species on O. cornifrons and on closely-related native North American mason bees that may now be exposed to novel pathogens. A global perspective is required for pathogen research as geographic ranges of insects and microorganisms shift due to intentional or accidental introductions.