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Sample records for fragilis group isolates

  1. In vitro effect of antibiotics on biofilm formation by Bacteroides fragilis group strains isolated from intestinal microbiota of dogs and their antimicrobial susceptibility.

    PubMed

    Silva, Janice Oliveira; Martins Reis, Ana Catarina; Quesada-Gómez, Carlos; Pinheiro, Adriana Queiroz; Freire, Rosemary Souza; Oriá, Reinaldo Barreto; de Carvalho, Cibele Barreto Mano

    2014-08-01

    The Bacteroides fragilis group strains colonize the intestinal tract of dogs as commensal bacteria. Nevertheless, they can be opportunistic pathogens responsible for significant morbidity and mortality rates in dogs, like in oral infections, abscesses and wound infections. The purpose of this study was to evaluate antimicrobial susceptibility in B. fragilis strains isolated from dogs intestinal microbiota and to evaluate the effect of subinhibitory concentrations of some antimicrobials on biofilm formation. A total of 30 B. fragilis group strains were tested for susceptibility to ten antimicrobial agents by broth microdilution method. Thirteen B. fragilis strains were tested for biofilm formation and the biofilm producer strains were chosen to evaluate the effect of subinhibitory concentrations of six antimicrobials on biofilm formation. The isolates were susceptible to amoxicillin-clavulanic acid, metronidazole, imipenem and chloramphenicol. Tetracycline and clindamycin were active against 50% and 33% of the strains, respectively. When biofilm-forming strains were grown in the presence of sub-MICs of imipenem and metronidazole, the inhibition of biofilm formation was observed. In contrast, enrofloxacin at ½ MIC caused a significant increase in biofilm formation in two of four strains examined. In conclusion, the B. fragilis group strains isolated were susceptible to most of the antimicrobials tested and the sub-MIC concentrations of imipenem, metronidazole and clindamycin were able to inhibit the biofilm formation. PMID:24799339

  2. Enterotoxigenic and nontoxigenic Bacteroides fragilis strains isolated in Brazil.

    PubMed

    Miranda, Karla R; Dias, Mariana F; Guimarães, Priscilla L S; Boente, Renata F; Pauer, Heidi; Ramos, Priscila Z; Falcão, Laís S; Ferreira, Eliane de O; Balassiano, Ilana T; Ferreira, Livia Q; Santos-Filho, Joaquim dos; Paula, Geraldo R de; Antunes, Eduardo N F; Avelar, Katia E S; Domingues, Regina M C P

    2008-11-01

    The presence of enterotoxigenic Bacteroides fragilis and nontoxigenic B. fragilis (NTBF) among 109 strains isolated from 1980-2008 in Brazil were investigated by PCR. One strain, representing 0.9% of the total analyzed strains, harbored the bft gene which was identified as bft-1 isoform based on PCR-RFLP and sequencing. Forty-nine strains (44.9%) exhibited the NTBF pattern III which possesses the flanking region required for pathogenicity island acquisition in which the bft gene is codified. These data reinforce the potential of B. fragilis as an emerging enteropathogen in our country. PMID:19057827

  3. A new chromogenic medium for isolation of Bacteroides fragilis suitable for screening for strains with antimicrobial resistance.

    PubMed

    Tierney, Daniel; Copsey, Sarah D; Morris, Trefor; Perry, John D

    2016-06-01

    There have been an increasing number of reports describing the acquisition of antimicrobial resistance by Bacteroides fragilis including the occurrence of strains with resistance to multiple antimicrobials that are relied upon for treatment of infections. The aim of this study was to design a chromogenic selective medium for isolation of B. fragilis that could be adapted for specific isolation of antimicrobial-resistant strains. Bacteroides chromogenic agar (BCA) was the result of this endeavour and allowed growth of Bacteroides spp. as black colonies and the efficient inhibition of almost all other genera tested. The medium also allowed some differentiation of B. fragilis from other members of the B. fragilis group. When compared with an adaptation of Bacteroides bile-esculin agar (BBE) for the isolation of B. fragilis from 100 stool samples, 30 isolates of B. fragilis were recovered on BCA compared with 19 isolates recovered on BBE (P = 0.022). When supplemented with meropenem (4 μg/ml) or metronidazole (2 μg/ml), BCA could be used to select for the growth of B. fragilis isolates with resistance to these agents. We conclude that BCA is a useful research tool for surveillance studies to assess the prevalence of B. fragilis and, in particular, the occurrence of antimicrobial-resistant strains. PMID:27060277

  4. First national survey of antibiotic susceptibility of the Bacteroides fragilis group: emerging resistance to carbapenems in Argentina.

    PubMed

    Fernández-Canigia, Liliana; Litterio, Mirta; Legaria, María C; Castello, Liliana; Predari, Silvia C; Di Martino, Ana; Rossetti, Adelaida; Rollet, Raquel; Carloni, Graciela; Bianchini, Hebe; Cejas, Daniela; Radice, Marcela; Gutkind, Gabriel

    2012-03-01

    The antibiotic susceptibility rates of 363 clinical Bacteroides fragilis group isolates collected from 17 centers in Argentina during the period from 2006 to 2009 were as follows: piperacillin-tazobactam, 99%; ampicillin-sulbactam, 92%; cefoxitin, 72%; tigecycline, 100%; moxifloxacin, 91%; and clindamycin, 52%. No metronidazole resistance was detected in these isolates during this time period. Resistance to imipenem, doripenem, and ertapenem was observed in 1.1%, 1.6%, and 2.3% of B. fragilis group strains, respectively. B. fragilis species showed a resistance profile of 1.5% to imipenem, 1.9% to doripenem, and 2.4% to ertapenem. This is the first report of carbapenem resistance in Argentina. The cfiA gene was present in 8 out of 23 isolates, all of them belonging to the B. fragilis species and displaying reduced susceptibility or resistance to carbapenems (MICs ≥ 4 μg/ml). Three out of eight cfiA-positive isolates were fully resistant to carbapenems, while 5 out of 8 isolates showed low-level resistance (MICs, 4 to 8 μg/ml). The inhibition by EDTA was a good predictor of the presence of metallo-β-lactamases in the fully resistant B. fragilis strains, but discrepant results were observed for low-level resistant isolates. B. fragilis was more susceptible to antimicrobial agents than other Bacteroides species. Bacteroides vulgatus species was the most resistant to ampicillin-sulbactam and piperacillin-tazobactam, and B. thetaiotaomicron/ovatus strains showed the highest level of resistance to carbapenems, with an unknown resistance mechanism. B. vulgatus and the uncommon non-Bacteroides fragilis species were the most resistant to moxifloxacin, showing an overall resistance rate of 15.1%. PMID:22232282

  5. Isolation, Detection, and Characterization of Enterotoxigenic Bacteroides fragilis in Clinical Samples

    PubMed Central

    Fathi, Payam; Wu, Shaoguang

    2016-01-01

    Bacteroides fragilis is an extensively studied anaerobic bacterium comprising the normal flora of the human gut. B. fragilis is known to be one of the most commonly isolated species from clinical samples and has been shown to cause a wide range of pathologies in humans [1, 2]. As an opportunistic pathogen B. fragilis can cause abscess formation and bacteremia [2]. Additionally in its enterotoxigenic form, B. fragilis is a known cause of diarrheal illness, is associated with inflammatory bowel disease, and has been recently characterized in patients with colon cancer [3 - 5]. As research in the field of the gut microbiome continues to expand at an ever increasing rate due to advances in the availability of next generation sequencing and analysis tools it is important to outline various molecular methods that can be employed in quickly detecting and isolating relevant strains of B. fragilis. This review outlines methods that are routinely employed in the isolation and detection of B. fragilis, with an emphasis on characterizing enterotoxigenic B. fragilis (ETBF) strains. PMID:27335618

  6. Heterogeneity in resistant fecal Bacteroides fragilis group collected from healthy people.

    PubMed

    Narimani, T; Douraghi, M; Owlia, P; Rastegar, A; Esghaei, M; Nasr, B; Talebi, M

    2016-06-01

    Normal nonpathogenic flora would represent a constant lake of resistance genes potentially transferable to human pathogens. To assess the prevalence of resistance genes and genetic variability of Bacteroides fragilis group (BFG) from normal flora, 177 Bacteroides isolates obtained from the fecal samples of healthy individuals. These isolates were subjected to antibiotic susceptibility testing and pulsed field gel electrophoresis (PFGE). The isolates were further tested for the presence of ermF, tetQ and bft genes by PCR. Our results indicated the presence of different clonal strains (1 common type and 57 single types) among the resistant isolates. The resistance rate for the six antibiotics in this study was between 1% and 95%. Most of the isolates (99%) were susceptible to metronidazole. ermF and tetQ were detected in all erythromycin and tetracycline resistant isolates. None of the isolates were carried bft gene. These data suggest dissemination of heterogenic clonal groups in healthy persons and resistance to 5 high commonly used antibiotics. PMID:26945562

  7. Isolation of a respiratory-deficient Kluyveromyces fragilis mutant for the production of ethanol from Jerusalem artichoke

    SciTech Connect

    Guiraud, J.P.; Bourgi, J.; Stervinou, M.; Claisse, M.; Galzy, P.

    1987-05-01

    A respiratory-deficient mutant of Kluyveromyces fragilis was isolated using a ethidium bromide mutagenesis. It was characterized by a loss of cytochromes a + a3 and by an improvement of its inulinase activity. Under anaerobic conditions this mutant was always better than the wild strain for ethanol production especially from Jerusalem artichoke extracts containing large amounts of high polyfructosans (early extracts).

  8. Distribution, detection of enterotoxigenic strains and antimicrobial drug susceptibility patterns of bacteroides fragilis group in diarrheic and non-diarrheic feces from brazilian infants.

    PubMed

    Ferreira, Débora Paula; Silva, Vânia Lúcia; Guimarães, Danielle Aparecida; Coelho, Cíntia Marques; Zauli, Danielle Alves Gomes; Farias, Luiz Macêdo; Carvalho, Maria Auxiliadora Roque; Diniz, Claudio Galuppo

    2010-07-01

    Despite the importance of gastrointestinal diseases and their global distribution, affecting millions of individuals around the world, the role and antimicrobial susceptibility patterns of anaerobic bacteria such as those in the Bacteroides fragilis group (BFG) are still unclear in young children. This study investigated the occurrence and distribution of species in the BFG and enterotoxigenic strains in the fecal microbiota of children and their antimicrobial susceptibility patterns. Diarrheic (n=110) and non-diarrheic (n=65) fecal samples from children aged 0-5 years old were evaluated. BFG strains were isolated and identified by conventional biochemical, physiological and molecular approaches. Alternatively, bacteria and enterotoxigenic strains were detected directly from feces by molecular biology. Antimicrobial drug susceptibility patterns were determined by the agar dilution method according to the guidelines for isolated bacteria. BFG was detected in 64.3% of the fecal samples (55% diarrheic and 80.4% non-diarrheic), and 4.6% were enterotoxigenic. Antimicrobial resistance was observed against ampicillin, ampicillin/sulbactam, piperacillin/tazobactam, meropenem, ceftriaxone, clindamycin and chloramphenicol. The data show that these bacteria are prevalent in fecal microbiota at higher levels in healthy children. The molecular methodology was more effective in identifying the B. fragilis group when compared to the biochemical and physiological techniques. The observation of high resistance levels stimulates thoughts about the indiscriminate use of antimicrobial drugs in early infancy. Further quantitative studies are needed to gain a better understanding of the role of these bacteria in acute diarrhea in children. PMID:24031535

  9. Nutritional features of Bacteroides fragilis subsp. fragilis.

    PubMed

    Varel, V H; Bryant, M P

    1974-08-01

    Studies of three reference strains of Bacteroides fragilis subsp. fragilis showed that they grow well in a minimal defined medium containing glucose, hemin, vitamin B(12), minerals, bicarbonate-carbon dioxide buffer, NH(4)Cl, and sulfide. The vitamin B(12) requirement of 0.1 ng/ml was replaced with 7.5 mug of methionine. Cysteine or sulfide was an excellent source of sulfur, thioglycolate was a poor source, and thiosulfate, methionine, beta-mercaptoethanol, dithiothreitol, sulfate, or sulfite did not serve as sole sources of sulfur. Neither single amino acids, nitrate, urea, nor a complex mixture of L-amino acids or peptides effectively replaced ammonia as the nitrogen source. Comparative studies with a few strains of other subspecies of B. fragilis including B. fragilis subsp. vulgatus, B. fragilis subsp. thetaiotaomicron, and B. fragilis subsp. distasonis indicate that they exhibit similar growth responses in the minimal medium. A single strain of B. fragilis subsp. ovatus required other materials. The results indicate the great biosynthetic ability of these organisms and suggest that, in their ecological niche within the large intestine, many nutrients such as amino acids are in very low supply, whereas materials such as ammonia, heme, and vitamin B(12), or related compounds, must be available during much of the time. PMID:4853401

  10. Transmission of Dientamoeba fragilis: pinworm or cysts?

    PubMed

    Clark, C Graham; Röser, Dennis; Stensvold, C Rune

    2014-03-01

    Recently, conflicting evidence has been published on the mode of transmission of the trichomonad Dientamoeba fragilis. Detection of D. fragilis DNA inside Enterobius vermicularis eggs agrees with the prediction of Dobell in 1940 that the eggs of a nematode act as a vector for transmission. However, the identification of a cyst stage of D. fragilis in the stool of rodents infected with a human isolate has also been reported, and this implies a life cycle similar to those of most other intestinal protistan parasites. Herein we discuss the recent data, identify gaps in the experimental evidence, and propose a method for determining which view of the life cycle of this organism is correct. PMID:24492020

  11. Detection of Bacteroides fragilis Enterotoxin Gene by PCR

    PubMed Central

    Shetab, Razeq; Cohen, Stuart H.; Prindiville, Thomas; Tang, Yajarayma J.; Cantrell, Mary; Rahmani, Darush; Silva, Joseph

    1998-01-01

    Bacteroides fragilis constitutes about 1% of the bacterial flora in intestines of normal humans. Enterotoxigenic strains of B. fragilis have been associated with diarrheal diseases in humans and animals. The enterotoxin produced by these isolates induces fluid changes in ligated intestinal loops and an in vitro cytotoxic response in HT-29 cells. We developed a nested PCR to detect the enterotoxin gene of B. fragilis in stool specimens. After DNA extraction, a 367-bp fragment was amplified with two outer primers. The amplicon from this reaction was subjected to a second round of amplification with a set of internal primers. With these inner primers, a 290-bp DNA fragment was obtained which was confirmed as part of the B. fragilis enterotoxin gene by Southern blotting with a nonradioactive internal probe and a chemiluminescence system. By this approach, B. fragilis enterotoxin gene sequences were detected in eight known enterotoxigenic human isolates and nine enterotoxigenic horse isolates. No amplification products were obtained from DNA extracted from 28 nonenterotoxigenic B. fragilis isolates or B. distasonis, B. thetaiotaomicron, B. uniformis, B. ovatus, Escherichia coli, or Clostridium difficile. The sensitivity of this assay allowed us to detect as little as 1 pg of enterotoxin DNA sequences or 100 to 1,000 cells of enterotoxigenic B. fragilis/g of stool. Enterotoxin production of all isolates was confirmed in vitro in HT-29 cells. A 100% correlation was obtained between enterotoxin detection by cytotoxin assay and the nested PCR assay. This rapid and sensitive assay can be used to identify enterotoxigenic B. fragilis and may be used clinically to determine the role of B. fragilis in diarrheal diseases. PMID:9620408

  12. In vitro susceptibility testing of Dientamoeba fragilis.

    PubMed

    Nagata, N; Marriott, D; Harkness, J; Ellis, J T; Stark, D

    2012-01-01

    Dientamoeba fragilis is a commonly encountered trichomonad which has been implicated as a cause of gastrointestinal disease in humans. Despite the frequency of reports recording infections with this parasite, little research has been undertaken in terms of antimicrobial susceptibility. The aim of this study was to evaluate the susceptibility of D. fragilis to several commonly used antiparasitic agents: diloxanide furoate, furazolidone, iodoquinol, metronidazole, nitazoxanide, ornidazole, paromomycin, secnidazole, ronidazole, tetracycline, and tinidazole. Antibiotic susceptibility testing was performed on four clinical strains of D. fragilis, designated A, E, M, and V, respectively. Molecular testing followed, and all strains were determined to be genotype 1. The activities of antiprotozoal compounds at concentrations ranging from 2 μg/ml to 500 μg/ml were determined via cell counts of D. fragilis trophozoites grown in dixenic culture. Minimum lethal concentrations (MLCs) were as follows: ornidazole, 8 to 16 μg/ml; ronidazole, 8 to 16 μg/ml; tinidazole, 31 μg/ml; metronidazole, 31 μg/ml; secnidazole, 31 to 63 μg/ml; nitazoxanide, 63 μg/ml; tetracycline, 250 μg/ml; furazolidone, 250 to 500 μg/ml; iodoquinol, 500 μg/ml; paromomycin, 500 μg/ml; and diloxanide furoate, >500 μg/ml. This is the first study to report the profiles of susceptibility to a wide range of commonly used treatments for clinical isolates of D. fragilis. Our study indicated 5-nitroimidazole derivatives to be the most active compounds in vitro against D. fragilis. PMID:22024820

  13. In Vitro Susceptibility Testing of Dientamoeba fragilis

    PubMed Central

    Nagata, N.; Marriott, D.; Harkness, J.; Ellis, J. T.

    2012-01-01

    Dientamoeba fragilis is a commonly encountered trichomonad which has been implicated as a cause of gastrointestinal disease in humans. Despite the frequency of reports recording infections with this parasite, little research has been undertaken in terms of antimicrobial susceptibility. The aim of this study was to evaluate the susceptibility of D. fragilis to several commonly used antiparasitic agents: diloxanide furoate, furazolidone, iodoquinol, metronidazole, nitazoxanide, ornidazole, paromomycin, secnidazole, ronidazole, tetracycline, and tinidazole. Antibiotic susceptibility testing was performed on four clinical strains of D. fragilis, designated A, E, M, and V, respectively. Molecular testing followed, and all strains were determined to be genotype 1. The activities of antiprotozoal compounds at concentrations ranging from 2 μg/ml to 500 μg/ml were determined via cell counts of D. fragilis trophozoites grown in dixenic culture. Minimum lethal concentrations (MLCs) were as follows: ornidazole, 8 to 16 μg/ml; ronidazole, 8 to 16 μg/ml; tinidazole, 31 μg/ml; metronidazole, 31 μg/ml; secnidazole, 31 to 63 μg/ml; nitazoxanide, 63 μg/ml; tetracycline, 250 μg/ml; furazolidone, 250 to 500 μg/ml; iodoquinol, 500 μg/ml; paromomycin, 500 μg/ml; and diloxanide furoate, >500 μg/ml. This is the first study to report the profiles of susceptibility to a wide range of commonly used treatments for clinical isolates of D. fragilis. Our study indicated 5-nitroimidazole derivatives to be the most active compounds in vitro against D. fragilis. PMID:22024820

  14. Pirin-like proteins are regulated by oxidative stress and iron in bacteroides fragilis and involved in the modulation of central energy metabolism and metronidazole susceptibility

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacteroides fragilis is the most frequent anaerobe isolated from human infections. Clinical isolates of B. fragilis are among the highest aerotolerant anaerobic bacteria. The oxidative stress response (OSR) in B. fragilis induces an array of genes enabling them to survive prolonged oxygen exposure i...

  15. Characterization of bactericidal activity of clindamycin against Bacteroides fragilis via kill curve methods.

    PubMed Central

    Klepser, M E; Banevicius, M A; Quintiliani, R; Nightingale, C H

    1996-01-01

    Kill curves were determined for five isolates of Bacteroides fragilis with clindamycin at concentrations equal to the MIC or to 4, 16, and 64 times the MIC. Examination of plots of log CFU per milliliter versus time revealed no association between the clindamycin concentration and the rate and extent of the bactericidal activity against B. fragilis at or below 64 times the MIC. PMID:8843310

  16. Current treatment options for Dientamoeba fragilis infections.

    PubMed

    Nagata, Noriyuki; Marriott, Deborah; Harkness, John; Ellis, John T; Stark, Damien

    2012-12-01

    Dientamoeba fragilis belongs to the trichomonad group of protozoan parasites and it has been implicated as a cause of gastrointestinal disease with world-wide prevalences ranging from 0.5% to 16%. The majority of patients with dientamoebiasis present with gastrointestinal complaints. Chronic symptoms are common with up to a third of patients exhibiting persistent diarrhoea. Numerous studies have successfully demonstrated parasite clearance, coupled with complete resolution of clinical symptoms following treatment with various antiparasitic compounds. Treatments reported to be successful for dientamoebiasis include carbarsone, diphetarsone, tetracyclines, paromomycin, erythromycin, hydroxyquinolines and the 5-nitroimidazoles, including metronidazole, secnidazole, tinidazole and ornidazole. It is of note that most current treatment data is based only on small number of case reports. No large scale double blind randomised placebo controlled trials testing the efficacy of antimicrobial agents against D. fragilis has been undertaken highlighting the need for further study. In addition there is very little in vitro susceptibility data available for the organism making some current treatment options questionable. The aim of this review is to critically discuss all treatment options currently available for dientamoebiasis. PMID:24533282

  17. Current treatment options for Dientamoeba fragilis infections

    PubMed Central

    Nagata, Noriyuki; Marriott, Deborah; Harkness, John; Ellis, John T.; Stark, Damien

    2012-01-01

    Dientamoeba fragilis belongs to the trichomonad group of protozoan parasites and it has been implicated as a cause of gastrointestinal disease with world-wide prevalences ranging from 0.5% to 16%. The majority of patients with dientamoebiasis present with gastrointestinal complaints. Chronic symptoms are common with up to a third of patients exhibiting persistent diarrhoea. Numerous studies have successfully demonstrated parasite clearance, coupled with complete resolution of clinical symptoms following treatment with various antiparasitic compounds. Treatments reported to be successful for dientamoebiasis include carbarsone, diphetarsone, tetracyclines, paromomycin, erythromycin, hydroxyquinolines and the 5-nitroimidazoles, including metronidazole, secnidazole, tinidazole and ornidazole. It is of note that most current treatment data is based only on small number of case reports. No large scale double blind randomised placebo controlled trials testing the efficacy of antimicrobial agents against D. fragilis has been undertaken highlighting the need for further study. In addition there is very little in vitro susceptibility data available for the organism making some current treatment options questionable. The aim of this review is to critically discuss all treatment options currently available for dientamoebiasis. PMID:24533282

  18. Characteristics of Bacteroides isolates from the cecum of conventional mice.

    PubMed Central

    Tannock, G W

    1977-01-01

    Bacteroides isolates from the cecum of conventional mice were characterized and grouped according to their ability to ferment or hydrolyze carbohydrates and other compounds believed to be present in the intestinal ecosystem. The isolates were divided into 11 groups on the basis of the fermentation of glucose, cellobiose, gum arabic and xylan (hemicelluloses), N-acetylglucosamine, and dextrin; the hydrolysis of starch and casein (proteolysis); and the production of indole. Stock cultures of B. fragilis, B. distasonis, B. ovatus, B. vulgatus, and B. ruminicola were characterized in the same way. The strains isolated most frequently from the mouse cecum resembled B. fragilis (except that arabinose was fermented) and B. thetaiotaomicron. PMID:869524

  19. Activation of Bacteroides fragilis toxin by a novel bacterial protease contributes to anaerobic sepsis in mice.

    PubMed

    Choi, Vivian M; Herrou, Julien; Hecht, Aaron L; Teoh, Wei Ping; Turner, Jerrold R; Crosson, Sean; Bubeck Wardenburg, Juliane

    2016-05-01

    Bacteroides fragilis is the leading cause of anaerobic bacteremia and sepsis. Enterotoxigenic strains that produce B. fragilis toxin (BFT, fragilysin) contribute to colitis and intestinal malignancy, yet are also isolated in bloodstream infection. It is not known whether these strains harbor unique genetic determinants that confer virulence in extra-intestinal disease. We demonstrate that BFT contributes to sepsis in mice, and we identify a B. fragilis protease called fragipain (Fpn) that is required for the endogenous activation of BFT through the removal of its auto-inhibitory prodomain. Structural analysis of Fpn reveals a His-Cys catalytic dyad that is characteristic of C11-family cysteine proteases that are conserved in multiple pathogenic Bacteroides spp. and Clostridium spp. Fpn-deficient, enterotoxigenic B. fragilis has an attenuated ability to induce sepsis in mice; however, Fpn is dispensable in B. fragilis colitis, wherein host proteases mediate BFT activation. Our findings define a role for B. fragilis enterotoxin and its activating protease in the pathogenesis of bloodstream infection, which indicates a greater complexity of cellular targeting and activity of BFT than previously recognized. The expression of fpn by both toxigenic and nontoxigenic strains suggests that this protease may contribute to anaerobic sepsis in ways that extend beyond its role in toxin activation. It could thus potentially serve as a target for disease modification. PMID:27089515

  20. Transposon mutagenesis of Bacteroides fragilis using a mariner transposon vector.

    PubMed

    Veeranagouda, Yaligara; Husain, Fasahath; Wexler, Hannah M

    2013-08-01

    The mariner transposon vector pYV07 was tested for use in the mutagenesis of Bacteroides fragilis 638R. The transposon vector efficiently generated mutants in B. fragilis 638R. The transposon disrupted genes were scattered throughout the genome of B. fragilis 638R. This method serves as a powerful tool to study B. fragilis. PMID:23664906

  1. Enteric group 17 in clinical isolates.

    PubMed

    Yang, D I; Chen, L C

    1989-11-01

    The Enteric Group 17, a new group of Enterobacteriaceae, has been classified (by the Centers for Disease Control, Atlanta, Georgia, U.S.A.) based on its positive methyl-red test as well as its negative response to Voges-Proskauer, motility, rhamnose and melibiose fermentation tests. The isolation rate of Enteric Group 17 among 500 clinical isolates of Enterobacteriaceae in Taiwan is 1.8% (9/500). This finding recommends that Taiwan's hospital laboratories should pay particular attention to the possible presence of this bacteria when an isolate has reactions similar to that of Enterobacter cloacae or other members of the Enterobacter species. PMID:2700157

  2. A novel strain of Bacteroides fragilis enhances phagocytosis and polarises M1 macrophages

    PubMed Central

    Deng, Huimin; Li, Zhengchao; Tan, Yafang; Guo, Zhaobiao; Liu, Yangyang; Wang, Ye; Yuan, Yuan; Yang, Ruifu; Bi, Yujing; Bai, Yang; Zhi, Fachao

    2016-01-01

    Commensal Bacteroides fragilis possesses immune-regulatory characteristics. Consequently, it has been proposed as a potential novel probiotic because of its therapeutic effects on immune imbalance, mental disorders and inflammatory diseases. Macrophages play a central role in the immune response, developing either a classical-M1 or an alternative-M2 phenotype after stimulation with various signals. The interactions between macrophages and B. fragilis, however, remain to be defined. Here, a new isolate of B. fragilis, ZY-312, was shown to possess admirable properties, including tolerance to simulated gastric fluid, intestinal fluid and ox bile, and good safety (MOI = 100, 200) and adherent ability (MOI = 100) to LoVo cells. Isolate ZY-312 cell lysate promoted phagocytosis of fluorescent microspheres and pathogenic bacteria in bone marrow-derived macrophage (BMDM) cells. Gene expression of IL-12, iNOS and IL-1β in BMDM cells was increased after treatment with ZY-312, indicating the induction of M1 macrophages, consistent with enhanced secretion of NO. Cell surface expression of CD80 and CD86 was also increased. This study is the first to demonstrate that B. fragilis enhances the phagocytic functions of macrophages, polarising them to an M1 phenotype. Our findings provide insight into the close relationship between B. fragilis and the innate immune system. PMID:27381366

  3. A novel strain of Bacteroides fragilis enhances phagocytosis and polarises M1 macrophages.

    PubMed

    Deng, Huimin; Li, Zhengchao; Tan, Yafang; Guo, Zhaobiao; Liu, Yangyang; Wang, Ye; Yuan, Yuan; Yang, Ruifu; Bi, Yujing; Bai, Yang; Zhi, Fachao

    2016-01-01

    Commensal Bacteroides fragilis possesses immune-regulatory characteristics. Consequently, it has been proposed as a potential novel probiotic because of its therapeutic effects on immune imbalance, mental disorders and inflammatory diseases. Macrophages play a central role in the immune response, developing either a classical-M1 or an alternative-M2 phenotype after stimulation with various signals. The interactions between macrophages and B. fragilis, however, remain to be defined. Here, a new isolate of B. fragilis, ZY-312, was shown to possess admirable properties, including tolerance to simulated gastric fluid, intestinal fluid and ox bile, and good safety (MOI = 100, 200) and adherent ability (MOI = 100) to LoVo cells. Isolate ZY-312 cell lysate promoted phagocytosis of fluorescent microspheres and pathogenic bacteria in bone marrow-derived macrophage (BMDM) cells. Gene expression of IL-12, iNOS and IL-1β in BMDM cells was increased after treatment with ZY-312, indicating the induction of M1 macrophages, consistent with enhanced secretion of NO. Cell surface expression of CD80 and CD86 was also increased. This study is the first to demonstrate that B. fragilis enhances the phagocytic functions of macrophages, polarising them to an M1 phenotype. Our findings provide insight into the close relationship between B. fragilis and the innate immune system. PMID:27381366

  4. Efficient utilization of complex N-linked glycans is a selective advantage for Bacteroides fragilis in extraintestinal infections

    PubMed Central

    Cao, Yanlu; Rocha, Edson R.; Smith, C. Jeffrey

    2014-01-01

    Bacteroides fragilis is the most common anaerobe isolated from clinical infections, and in this report we demonstrate a characteristic of the species that is critical to their success as an opportunistic pathogen. Among the Bacteroides spp. in the gut, B. fragilis has the unique ability of efficiently harvesting complex N-linked glycans from the glycoproteins common to serum and serous fluid. This activity is mediated by an outer membrane protein complex designated as Don. Using the abundant serum glycoprotein transferrin as a model, it has been shown that B. fragilis alone can rapidly and efficiently deglycosylate this protein in vitro and that transferrin glycans can provide the sole source of carbon and energy for growth in defined media. We then showed that transferrin deglycosylation occurs in vivo when B. fragilis is propagated in the rat tissue cage model of extraintestinal growth, and that this ability provides a competitive advantage in vivo over strains lacking the don locus. PMID:25139987

  5. Intragenomic Variation in the Internal Transcribed Spacer 1 Region of Dientamoeba fragilis as a Molecular Epidemiological Marker▿

    PubMed Central

    Bart, Aldert; van der Heijden, Harold M.; Greve, Sophie; Speijer, Dave; Landman, Wil J.; van Gool, Tom

    2008-01-01

    Dientamoeba fragilis is a parasite that has been recognized to be a causative agent of gastrointestinal symptoms. Because in most studies only some infected persons experience symptoms, it is possible that D. fragilis is a heterogeneous species with variants that display similar morphologies but different pathogenicities. The search for genetic variation in D. fragilis was based on the small-subunit rRNA gene, which was not found to be useful for molecular epidemiology. In this report, we describe the isolation and characterization of additional rRNA gene cluster sequences, the internal transcribed spacer 1 (ITS-1)-5.8S rRNA gene-ITS-2 region. For comparative purposes, we also isolated the ITS-1-5.8S rRNA gene-ITS-2 region of Histomonas meleagridis, a protozoan parasite of birds and a close relative of D. fragilis. This region was found to be highly variable, and 11 different alleles of the ITS-1 sequence could be identified. Variation in the ITS-1 region was found to be intragenomic, with up to four different alleles in a single isolate. So-called C profiles were produced from the ITS-1 repertoire of single isolates,. Analysis of the C profiles of isolates from nonrelated patients identified several clearly distinguishable strains of D. fragilis. Within families, it was shown that members can be infected with the same or different strains of D. fragilis. In conclusion, the ITS-1 region can serve as a molecular epidemiological tool for the subtyping of D. fragilis directly from feces. This may serve as a means of studying the transmission, geographical distribution, and relationships between strains and the pathogenicity of this parasite. PMID:18650356

  6. The dynamics of isolated Local Group galaxies

    NASA Astrophysics Data System (ADS)

    Kirby, Evan N.; Bullock, James S.; Boylan-Kolchin, Michael; Kaplinghat, Manoj; Cohen, Judith G.

    2014-03-01

    We measured velocities of 862 individual red giant stars in seven isolated dwarf galaxies in the Local Group: NGC 6822, IC 1613, VV 124 (UGC 4879), the Pegasus dwarf irregular galaxy (DDO 216), Leo A, Cetus and Aquarius (DDO 210). We also computed velocity dispersions, taking into account the measurement uncertainties on individual stars. None of the isolated galaxies is denser than the densest Local Group satellite galaxy. Furthermore, the isolated dwarf galaxies have no obvious distinction in the velocity dispersion-half-light radius plane from the satellite galaxies of the Milky Way and M31. The similarity of the isolated and satellite galaxies' dynamics and structural parameters imposes limitations on environmental solutions to the `too big to fail' problem, wherein there are fewer dense dwarf satellite galaxies than would be expected from cold dark matter simulations. This data set also has many other applications for dwarf galaxy evolution, including the transformation of dwarf irregular into dwarf spheroidal galaxies. We intend to explore these issues in future work.

  7. Case-Control Study on the Role of Enterotoxigenic Bacteroides fragilis as a Cause of Diarrhea among Children in Kolkata, India

    PubMed Central

    Ramamurthy, Dharanidharan; Pazhani, Gururaja P.; Sarkar, Anirban; Nandy, Ranjan K.; Rajendran, Krishnan; Sur, Dipika; Manna, Bamkesh; Ramamurthy, Thandavarayan

    2013-01-01

    A total of 874 fecal specimens (446 diarrheal cases and 428 controls) from diarrheal children admitted in the Infectious Diseases Hospital, Kolkata and age and sex matched asymptomatic subjects from an urban community were assessed for the prevalence of enterotoxigenic Bacteroides fragilis (ETBF). Isolates of B. fragilis were tested for the presence of enterotoxin gene (bft) by PCR. The detection rate of ETBF was 7.2% (63 of 874 specimens) that prevailed equally in diarrheal cases and controls (7.2% each; 32 of 446 cases and 31 of 428 controls). Male children up to one year age group was significantly (p<0.05) associated with ETBF infection as compared to children > 2 years of age in cases and controls. In 25 ETBF isolates, the bft gene was genotyped using PCR-RFLP and only two alleles were identified with prevalence rate of 40% and 60% for bft-1 and bft-3, respectively. All the ETBF isolates were susceptible for chloramphenicol and imipenem but resistant to clindamycin (48%), moxifloxacin (44%) and metronidazole (32%). Resistance of ETBF to moxifloxacin (44%) and metronidazole is an emerging trend. Pulsed-field gel electrophoresis (PFGE) revealed that majority of the ETBF isolates are genetically diverse. In the dendrogram analysis, two clusters were identified, one with ETBF resistant to 5–8 antimicrobials and the other cluster with metronidazole and moxifloxacin susceptible isolates from diarrheal cases. To our knowledge, this is the first detailed report on ETBF from India indicating its clinical importance and molecular characteristics. PMID:23577134

  8. The Bfp60 surface adhesin is an extracellular matrix and plasminogen protein interacting in Bacteroides fragilis

    PubMed Central

    de Oliveira Ferreira, Eliane; Teixeira, Felipe; Cordeiro, Fabiana; Lobo, Leandro Araujo; Rocha, Edson R.; Smith, Jeffrey C.; Domingues, Regina M C P

    2014-01-01

    Plasminogen (Plg) is a highly abundant protein found in the plasma component of blood and is necessary for the degradation of fibrin, collagen, and other structural components of tissues. This fibrinolytic system is utilized by several pathogenic species of bacteria to manipulate the host plasminogen system and facilitate invasion of tissues during infection by modifying the activation of this process through the binding of Plg at their surface. Bacteroides fragilis is the most commonly isolated Gram-negative obligate anaerobe from human clinical infections, such as intra-abdominal abscesses and anaerobic bacteraemia. The ability of B. fragilis to convert plasminogen (Plg) into plasmin has been associated with an outer membrane protein named Bfp60. In this study, we characterized the function of Bfp60 protein in B. fragilis 638R by constructing the bfp60 defective strain and comparing its with that of the wild type regarding binding to laminin-1 (LMN-1) and activation of Plg into plasmin. Although the results showed in this study indicate that Bfp60 surface protein of B. fragilis is important for the recognition of LMN-1 and Plg activation, a significant slow activation of Plg into plasmin was observed in the mutant strain. For that reason, the possibility of another unidentified mechanism activating Plg is also present in B. fragilis can not be discarded. The results demonstrate that Bfp60 protein is responsible for the recognition of laminin and Plg-plasmin activation. Although the importance of this protein is still unclear in the pathogenicity of the species, it is accepted that since other pathogenic bacteria use this mechanism to disseminate through the extracellular matrix during the infection, it should also contribute to the virulence of B. fragilis. PMID:23850366

  9. Differential proteomic analysis of outer membrane enriched extracts of Bacteroides fragilis grown under bile salts stress.

    PubMed

    Boente, Renata F; Pauer, Heidi; Silva, Deborah N S; Filho, Joaquim Santos; Sandim, Vanessa; Antunes, Luis Caetano M; Ferreira, Rosana Barreto Rocha; Zingali, Russolina B; Domingues, Regina M C P; Lobo, Leandro A

    2016-06-01

    Bacteroides fragilis is the most commonly isolated anaerobic bacteria from infectious processes. Several virulence traits contribute to the pathogenic nature of this bacterium, including the ability to tolerate the high concentrations of bile found in the gastrointestinal tract (GIT). The activity of bile salts is similar to detergents and may lead to membrane permeabilization and cell death. Modulation of outer membrane proteins (OMPs) is considered a crucial event to bile salts resistance. The primary objective of the current work was to identify B. fragilis proteins associated with the stress induced by high concentration of bile salts. The outer membrane of B. fragilis strain 638R was isolated after growth either in the presence of 2% conjugated bile salts or without bile salts. The membrane fractions were separated on SDS-PAGE and analyzed by ESI-Q/TOF tandem mass spectrometry. A total of 37 proteins were identified; among them nine were found to be expressed exclusively in the absence of bile salts whereas eight proteins were expressed only in the presence of bile salts. These proteins are related to cellular functions such as transport through membrane, nutrient uptake, and protein-protein interactions. This study demonstrates the alteration of OMPs composition in B. fragilis during bile salts stress resistance and adaptation to environmental changes. Proteomics of OMPs was also shown to be a useful approach in the identification of new targets for functional analyses. PMID:26948242

  10. Isolated galaxies, pairs, and groups of galaxies

    NASA Technical Reports Server (NTRS)

    Kuneva, I.; Kalinkov, M.

    1990-01-01

    The authors searched for isolated galaxies, pairs and groups of galaxies in the CfA survey (Huchra et al. 1983). It was assumed that the distances to galaxies are given by R = V/H sub o, where H sub o = 100 km s(exp -1) Mpc(exp -1) and R greater than 6 Mpc. The searching procedure is close to those, applied to find superclusters of galaxies (Kalinkov and Kuneva 1985, 1986). A sphere with fixed radius r (asterisk) is described around each galaxy. The mean spatial density in the sphere is m. Let G (sup 1) be any galaxy and G (sup 2) be its nearest neighbor at a distance R sub 2. If R sub 2 exceeds the 95 percent quintile in the distribution of the distances of the second neighbors, then G (sup 1) is an isolated galaxy. Let the midpoint of G (sup 1) and G (sup 2) be O sub 2 and r sub 2=R sub 2/2. For the volume V sub 2, defined with the radius r sub 2, the density D sub 2 less than k mu, the galaxy G (sup 2) is a single one and the procedure for searching for pairs and groups, beginning with this object is over and we have to pass to another object. Here the authors present the groups - isolated and nonisolated - with n greater than 3, found in the CfA survey in the Northern galactic hemisphere. The parameters used are k = 10 and r (asterisk) = 5 Mpc. Table 1 contains: (1) the group number, (2) the galaxy, nearest to the multiplet center, (3) multiplicity n, (4) the brightest galaxy if it is not listed in (2); (5) and (6) are R.A. and Dec. (1950), (7) - mean distance D in Mpc. Further there are the mean density rho (8) of the multiplet (galaxies Mpc (exp -3), (9) the density rho (asterisk) for r (asterisk) = 5 Mpc and (10) the density rho sub g for the group with its nearest neighbor. The parenthesized digits for densities in the last three columns are powers of ten.

  11. Prospective Study of the Prevalence, Genotyping, and Clinical Relevance of Dientamoeba fragilis Infections in an Australian Population

    PubMed Central

    Stark, D.; Beebe, N.; Marriott, D.; Ellis, J.; Harkness, J.

    2005-01-01

    A prospective study was conducted over a 30-month period, in which fecal specimens from 6,750 patients were submitted to the Department of Microbiology at St. Vincent's Hospital, Sydney, Australia. Trophozoites of Dientamoeba fragilis were detected in 60 (0.9%) patients by permanent staining, and confirmation was performed by PCR. Gastrointestinal symptoms were present in all patients, with diarrhea and abdominal pain the most common symptoms. Thirty-two percent of patients presented with chronic symptoms. The average age of infected patients was 39.8 years. No correlation was found between D. fragilis and Enterobius vermicularis, a proposed vector of transmission for D. fragilis. The genetic diversity of 50 D. fragilis isolates was examined by PCR, and the PCR products were analyzed for the presence of restriction fragment length polymorphisms. These results showed no variation in the small-subunit rRNA gene and demonstrated a single genotype for all Australian isolates. This study shows the potential pathogenic properties of D. fragilis and the need for all laboratories to routinely test for this organism. PMID:15956388

  12. Bis-sesquiterpene from the Marine Sponge Dysidea fragilis.

    PubMed

    Kiem, Phan Van; Nhiem, Nguyen Xuan; Tai, Bui Huu; Anh, Hoang Le Tuan; Hang, Dan Thi Thuy; Cuc, Nguyen Thi; Huyen, Le Thi; Nam, Nguyen Hoai; Yen, Pham Hai; Thung, Do Cong; Minh, Chau Van

    2016-04-01

    Two new sesquiterpenes and one new bis-sesquiterpene, named dysinidins C-E (1-3) along with three known sterols, dysideasterol F, 9α,l lα-epoxycholest-7-en-3β,5α,6α-triol, and 9α,11α-epoxycholest-7-en-3β,5α,6α,19-tetrol 6-acetate (4-6) were isolated from the Vietnamese marine sponge Dysidea fragilis (Montagu, 1814). Their structures were determined by 1D- and 2D-NMR spectroscopies and HR-ESI-MS, as well as by comparison with reported literature data. Compounds 4-6 were found to inhibit eight human cancer cell lines (KB, LU-1, HL-60, LNCaP, SK-Mel-2, HepG-2, MCF-7, and PC-3), with IC50 values ranging from 7.3 to 31.5 µM. PMID:27396186

  13. Role of Enterotoxigenic Bacteroides fragilis in Children Less Than 5 Years of Age With Diarrhea in Tabriz, Iran

    PubMed Central

    Akhi, Mohammad Taghi; Jedari Seifi, Sirus; Asgharzadeh, Mohammad; Ahangarzadeh Rezaee, Mohammad; Abdoli Oskuei, Shahram; Pirzadeh, Tahereh; Memar, Mohammad Yousef; Alizadeh, Naser; Seifi Yarijan Sofla, Hasan

    2016-01-01

    Background Diarrhea is the most frequent health problem among children in developing countries. Defining the etiology of acute diarrhea is critical to disease therapy and prevention. Some anaerobic bacteria such as Enterotoxigenic Bacteroides fragilis (ETBF) strains cause diarrheal disease by production of enterotoxin in children less than 5 years old. Objectives This study aimed to evaluate the prevalence of ETBF among common bacteria and viruses causing diarrhea in children aged less than five years. Materials and Methods One hundred diarrheal stools were cultured for detection of aerobic and anaerobic pathogen bacteria by direct plating on selective media and antibiotic susceptibility tests were performed according to clinical and laboratory standards institute (CLSI) guidelines on isolates of ETBF. The enterotoxigenic gene among B. fragilis isolates was also investigated using the polymerase chain reaction (PCR) method. Detection of viral pathogens was carried out using the latex agglutination test. Results Ten B. fragilis were isolated from 100 diarrheal fecal specimens. All isolates were susceptible to metronidazole, while 10% were susceptible to clindamycin. Four (40%) ETBF were isolated. Rotaviruses (57.2%) and adenoviruses (18.6%) were the most frequently detected etiological agents. Conclusions ETBF is one of the etiological agents that may cause diarrhea in children but it is not the commonest of them. Metronidazole is still an effective antibiotic against B. fragilis. Viruses are the most important etiological agents of diarrhea in children less than 5 years of age.

  14. Fecal detection of enterotoxigenic Bacteroides fragilis.

    PubMed

    Chen, L A; Van Meerbeke, S; Albesiano, E; Goodwin, A; Wu, S; Yu, H; Carroll, K; Sears, C

    2015-09-01

    Bacteroides fragilis is a common colonic symbiote of which one subtype, enterotoxigenic Bacteroides fragilis (ETBF), causes inflammatory diarrhea. However, asymptomatic ETBF colonization is common. Through its primary virulence factor, B. fragilis toxin (BFT), ETBF causes asymptomatic, chronic colitis in C57BL/6 mice and increased colon tumorigenesis in multiple intestinal neoplasia mice. Human studies suggest an association between ETBF infection, inflammatory bowel disease, and colon cancer. Additional studies on ETBF epidemiology are, therefore, crucial. The goal of this study is to develop a reliable fecal diagnostic for ETBF. To develop a sensitive assay for ETBF, we tested multiple protocols on mouse stools spiked with serially diluted ETBF. Each assay was based on either touchdown or quantitative polymerase chain reaction (qPCR) and used primers targeted to bft to detect ETBF. Using touchdown PCR or qPCR, the mean ETBF detection limit was 1.55 × 10(6) colony-forming units (CFU)/g stool and 1.33 × 10(4) CFU/g stool, respectively. Augmentation of Bacteroides spp. growth in fecal samples using PYGB (Peptone Yeast Glucose with Bile) broth enhanced ETBF detection to 2.93 × 10(2) CFU/g stool using the touchdown PCR method and 2.63 × 10(2) CFU/g stool using the qPCR method. Fecal testing using combined culture-based amplification and bft touchdown PCR is a sensitive assay for the detection of ETBF colonization and should be useful in studying the role of ETBF colonization in intestinal diseases, such as inflammatory bowel disease and colon cancer. We conclude that touchdown PCR with culture-based amplification may be the optimal ETBF detection strategy, as it performs as well as qPCR with culture-based amplification, but is a less expensive technique. PMID:26173688

  15. Treatment of Dientamoeba fragilis in Patients with Irritable Bowel Syndrome

    PubMed Central

    Engsbro, Anne Line; Stensvold, C. Rune; Nielsen, Henrik V.; Bytzer, Peter

    2012-01-01

    The role of Dientamoeba fragilis in irritable bowel syndrome (IBS) is incompletely known. We aimed to investigate whether eradication of D. fragilis alleviates symptoms in IBS. Twenty-five D. fragilis-positive IBS patients were treated with Metronidazole (MZ) or Tetracycline. The patients were mostly female (89%), and mean age (SD) was 35.1 (8.2) years. Microbiological response, evaluated 2 weeks post-treatment, was observed in 15 of 25 patients (60%), all by MZ. Clinical response, defined as adequate relief of symptoms, was observed in 7 of 22 patients (32%), all by MZ. In a logistic regression analysis, we found no significant association between clinical and microbiological response. This case study did not support our hypothesis of a simple association between D. fragilis and IBS. Some D. fragilis-infections were insufficiently treated by MZ. Further studies into the prevalence and effect of eradication of D. fragilis in IBS and into efficient treatments of D. fragilis are warranted. PMID:23091195

  16. Dientamoeba fragilis DNA detection in Enterobius vermicularis eggs

    PubMed Central

    Ögren, Jessica; Dienus, Olaf; Löfgren, Sture; Iveroth, Peter; Matussek, Andreas

    2013-01-01

    Dientamoeba fragilis is an intestinal protozoan suspected of causing gastrointestinal symptoms, and its mode of transmission is unknown, although first described almost a century ago. A hypothesis is that Enterobius vermicularis is a vector for D. fragilis, and recently, D. fragilis DNA was detected within surface-sterilized eggs of E. vermicularis. Using real-time PCR, we detected D. fragilis DNA in 18 (85%) of 21 samples of E. vermicularis eggs collected from patients harbouring D. fragilis in faeces. This finding supports the hypothesis that E. vermicularis may have an important role in the transmission of D. fragilis. This paper describes a protocol to wash and surface-sterilize E. vermicularis eggs, with the aim of showing presence of both E. vermicularis and D. fragilis specific DNA within, and the results from 20 co-infected patients. The study has merit as a confirmatory study of the trials by Röser et al. (2013), and includes improvements of the protocol. PMID:23893951

  17. The Bacteroides fragilis toxin fragilysin disrupts the paracellular barrier of epithelial cells.

    PubMed Central

    Obiso, R J; Azghani, A O; Wilkins, T D

    1997-01-01

    Bacteroides fragilis is a member of the normal colonic microflora of most mammals and is the most commonly isolated anaerobe from human clinical specimens. Some strains produce a toxin (fragilysin, a zinc-metalloproteinase) implicated as a cause of diarrheal disease in farm animals and humans. Studies in our laboratory confirm that the proteolytic activity of this toxin is responsible for the fluid secretion and tissue damage observed in vivo. In this study, we investigated the effects of fragilysin on the paracellular barrier of epithelial cells. Researchers suggest that, since the toxin rapidly intoxicates HT-29 cells, it may be internalized. However, we could not prevent cell rounding by using inhibitors of receptor-mediated endocytosis, which indicates that the toxin may act outside the cell. Based on these observations, we studied the effects of the highly purified B. fragilis fragilysin on the barrier function of cultured epithelial cells. Fragilysin rapidly increased the permeability of the paracellular barrier of epithelial cells to ions (decrease in electrical resistance across monolayers) and to larger molecules (increase in mannitol flux across monolayers). We tested a human colon cell line and cell lines from the lung and the kidney; the human colon cell line was most sensitive, but all three were affected in the same manner. Our studies show that B. fragilis fragilysin alters the barrier function of the epithelial lining, possibly by degrading the tight junction proteins, such as ZO-1. The proteolytic activity is required to cause this effect. The toxin's action has been assumed to be limited to the intestine; however, our studies show that fragilysin could also contribute to the pathogenesis of B. fragilis in extraintestinal infections. PMID:9119484

  18. In vitro utilization of mucin by Bacteroides fragilis.

    PubMed Central

    Roberton, A M; Stanley, R A

    1982-01-01

    A method for isolating pig colon mucin in a soluble high-molecular-weight form, suitable for addition to bacterial growth media, is described. This preparation was utilized as a sole carbohydrate energy source by two strains of Bacteroides fragilis. The extent of degradation was compared with that of commercial pig gastric mucin by the same strains. Gas-liquid chromatographic analysis of the mucin carbohydrates and gel chromatography of the preparations were carried out before and after in vitro degradation. The mucin carbohydrates were utilized only to a very limited extent, colon mucin being more resistant to degradation than gastric mucin. Both mucins chromatographed at or near the excluded volume on Sepharose 4B, and only in the case of ATCC 25285 grown on gastric mucin was a significant degradation peak detected. If mucins are degraded in vivo by the sequential action of several bacteria, a pure culture in vitro might be expected to degrade mucins to a limited extent only. Techniques previously used to examine mucin utilization by pure cultures may have overlooked limited mucin degradation demonstrated by the methods used in this work. PMID:6174077

  19. Pharmacodynamics of Trovafloxacin and Levofloxacin against Bacteroides fragilis in an In Vitro Pharmacodynamic Model

    PubMed Central

    Peterson, M. L.; Hovde, L. B.; Wright, D. H.; Brown, G. H.; Hoang, A. D.; Rotschafer, J. C.

    2002-01-01

    An in vitro pharmacodynamic investigation was conducted to explore whether the area under the concentration time curve from 0 to 24 h (AUC0–24)/MIC ratio could predict fluoroquinolone performance against Bacteroides fragilis. An in vitro model was used to generate kill curves for trovafloxacin (TVA) and levofloxacin (LVX) at AUC0–24/MIC ratios of 1 to 406 against three strains of B. fragilis (ATCC 25285, ATCC 23745, and clinical isolate M97-117). TVA and LVX were bolused prior to the start of experiments to achieve the corresponding AUC0–24/MIC ratio. Experiments were performed in duplicate over 24 h and in an anaerobic environment. Analyses of antimicrobial performance were conducted by comparing the rates of bacterial kill (K) using nonlinear regression analysis with 95% confidence intervals. Statistical significance was defined as a lack of overlap in the 95% confidence limits generated from the slope of each kill curve. For both TVA and LVX, K was maximized once an AUC0–24/MIC ratio of ≥40 was achieved and was not further increased despite a 10-fold increase in AUC0–24/MIC from approximately 40 to 400 against all three strains of B. fragilis. No significant differences were found in K between AUC0–24/MIC ratios of approximately 40 to 200. In experiments where AUC0–24/MIC ratios that were ≥ 5 and ≤ 44 were conducted, 64% demonstrated regrowth at 24 h. Resistant strains were selected in 50% of those experiments, demonstrating regrowth, which resulted in increased MICs of two- to 16-fold for both TVA and LVX. Regrowth did not occur, nor were resistant strains selected in any studies with an AUC/MIC that was > 44. Our findings suggest that fluoroquinolones provide antibacterial effects against B. fragilis in a concentration-independent manner associated with an AUC0–24/MIC ratio of ≥40. Also, the potential for the selection of resistant strains of B. fragilis may increase with an AUC0–24/MIC ratio of ≤44. PMID:11751135

  20. Improved methods for typing nontypeable isolates of group B streptococci.

    PubMed

    Benson, Jeffrey A; Flores, Aurea E; Baker, Carol J; Hillier, Sharon L; Ferrieri, Patricia

    2002-06-01

    Group B streptococci (GBS) are classified by capsular polysaccharide (CPS) type and by cell surface-expressed proteins (c and R). Isolates lacking detectable CPS are considered nontypeable (NT) although they frequently express surface proteins. Immunological and genetic methods were used to study 91 NT GBS isolates collected during surveillance studies for invasive disease or colonization in pregnant or non-pregnant women and neonates less than seven days of age. CPS production was upregulated by the addition of glucose and sodium phosphate to Todd-Hewitt broth (THB) and cells were extracted using hot HCl or mutanolysin. Extracts were tested with antisera for specific CPS types Ia, Ib, and II - VIII by double immunodiffusion (DD) in agarose. By mutanolysin extraction, 12 (13.2%) of the 91 isolates were typeable. In contrast, only four of these 12 newly typeable isolates tested positive for CPS with the HCl extracts of cells grown in modified THB. DNA was analyzed by pulsed-field gel electrophoresis (PFGE) using SmaI restriction with NT isolates grouped by protein profile to facilitate analysis. PFGE results of the NT isolates were compared to DNA profiles of typeable isolates and were correlated with the DD results. The DNA profiles of the newly typeable isolates were similar to profiles of isolates with corresponding defined CPS type. Of the remaining 78 NT isolates digested by SmaI, 63 (80.8%) had DNA profiles that resembled those of specific types of GBS. These approaches will be useful for classification of NT isolates in continued epidemiological surveillance associated with GBS vaccine trials. PMID:12139427

  1. Phylogenetic Group Determination of Escherichia coli Isolated from Animals Samples.

    PubMed

    Coura, Fernanda Morcatti; Diniz, Soraia de Araújo; Silva, Marcos Xavier; Mussi, Jamili Maria Suhet; Barbosa, Silvia Minharro; Lage, Andrey Pereira; Heinemann, Marcos Bryan

    2015-01-01

    This study analyzes the occurrence and distribution of phylogenetic groups of 391 strains of Escherichia coli isolated from poultry, cattle, and water buffalo. The frequency of the phylogroups was A = 19%, B1 = 57%, B2 = 2.3%, C = 4.6%, D = 2.8%, E = 11%, and F = 3.3%. Phylogroups A (P < 0.001) and F (P = 0.018) were associated with E. coli strains isolated from poultry, phylogroups B1 (P < 0.001) and E (P = 0.002) were associated with E. coli isolated from cattle, and phylogroups B2 (P = 0.003) and D (P = 0.017) were associated with E. coli isolated from water buffalo. This report demonstrated that some phylogroups are associated with the host analyzed and the results provide knowledge of the phylogenetic composition of E. coli from domestic animals. PMID:26421310

  2. Phylogenetic Group Determination of Escherichia coli Isolated from Animals Samples

    PubMed Central

    Morcatti Coura, Fernanda; Diniz, Soraia de Araújo; Silva, Marcos Xavier; Mussi, Jamili Maria Suhet; Barbosa, Silvia Minharro; Lage, Andrey Pereira; Heinemann, Marcos Bryan

    2015-01-01

    This study analyzes the occurrence and distribution of phylogenetic groups of 391 strains of Escherichia coli isolated from poultry, cattle, and water buffalo. The frequency of the phylogroups was A = 19%, B1 = 57%, B2 = 2.3%, C = 4.6%, D = 2.8%, E = 11%, and F = 3.3%. Phylogroups A (P < 0.001) and F (P = 0.018) were associated with E. coli strains isolated from poultry, phylogroups B1 (P < 0.001) and E (P = 0.002) were associated with E. coli isolated from cattle, and phylogroups B2 (P = 0.003) and D (P = 0.017) were associated with E. coli isolated from water buffalo. This report demonstrated that some phylogroups are associated with the host analyzed and the results provide knowledge of the phylogenetic composition of E. coli from domestic animals. PMID:26421310

  3. 60. Shock isolator at center, pneumatic control group panel at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    60. Shock isolator at center, pneumatic control group panel at left, power distribution box at right, all at right of entrance to lcc. - Ellsworth Air Force Base, Delta Flight, Launch Control Facility, County Road CS23A, North of Exit 127, Interior, Jackson County, SD

  4. A Distinct Group II Alphabaculovirus Isolated from a Peridroma Species.

    PubMed

    Rohrmann, George F; Erlandson, Martin A; Theilmann, David A

    2015-01-01

    The genome sequence of an alphabaculovirus isolated from a Peridroma species indicated that it is a novel member of a group II lineage most closely related to alphabaculoviruses from Spodoptera exigua and Agrotis segetum. It contains a genome of 151,110 nucleotides (nt), with a G+C content of 53.3%. PMID:25838477

  5. PREVALENCE OF DIENTAMOEBA FRAGILIS AMONG AN ORANG ASLI POPULATION IN RURAL MALAYSIA.

    PubMed

    Anuar, Tengku Shahrul; Hasim, Liyana; Moktar, Norhayati; Salleh, Fatmah Md; Al-Mekhlafi, Hesham M

    2015-09-01

    Dientamoeba fragilis is a trichomonad parasite that can infect the gastrointestinal tract of humans causing gastrointestinal disease. Little is known about its epidemiology. We evaluated the prevalence of D. fragilis by conducting a cross sectional study of an Orang Asli population in rural Malaysia. We examined stool samples from 150 participants for D. fragilis using Wheatley's trichrome stain and collected demographic data from each participant using a structured questionnaire. Five participants (3.3%) had D. fragilis in their stool; four of these were aged < 15 years; 3 were male and 2 were female. All participants with positive stool sample for D. fragilis were symptomatic; 3 had diarrhea and 2 had other gastrointestinal symptoms. D. fragilis is present in the study population. Further studies are needed to determine the virulence, pathogenicity and mode of transmission of D. fragilis in the study population. PMID:26863855

  6. DNA Inversion Regulates Outer Membrane Vesicle Production in Bacteroides fragilis

    PubMed Central

    Nakayama-Imaohji, Haruyuki; Hirota, Katsuhiko; Yamasaki, Hisashi; Yoneda, Saori; Nariya, Hirofumi; Suzuki, Motoo; Secher, Thomas; Miyake, Yoichiro; Oswald, Eric; Hayashi, Tetsuya; Kuwahara, Tomomi

    2016-01-01

    Phase changes in Bacteroides fragilis, a member of the human colonic microbiota, mediate variations in a vast array of cell surface molecules, such as capsular polysaccharides and outer membrane proteins through DNA inversion. The results of the present study show that outer membrane vesicle (OMV) formation in this anaerobe is also controlled by DNA inversions at two distantly localized promoters, IVp-I and IVp-II that are associated with extracellular polysaccharide biosynthesis and the expression of outer membrane proteins. These promoter inversions are mediated by a single tyrosine recombinase encoded by BF2766 (orthologous to tsr19 in strain NCTC9343) in B. fragilis YCH46, which is located near IVp-I. A series of BF2766 mutants were constructed in which the two promoters were locked in different configurations (IVp-I/IVp-II = ON/ON, OFF/OFF, ON/OFF or OFF/ON). ON/ON B. fragilis mutants exhibited hypervesiculating, whereas the other mutants formed only a trace amount of OMVs. The hypervesiculating ON/ON mutants showed higher resistance to treatment with bile, LL-37, and human β-defensin 2. Incubation of wild-type cells with 5% bile increased the population of cells with the ON/ON genotype. These results indicate that B. fragilis regulates the formation of OMVs through DNA inversions at two distantly related promoter regions in response to membrane stress, although the mechanism underlying the interplay between the two regions controlled by the invertible promoters remains unknown. PMID:26859882

  7. Dientamoeba fragilis, the Neglected Trichomonad of the Human Bowel.

    PubMed

    Stark, Damien; Barratt, Joel; Chan, Douglas; Ellis, John T

    2016-07-01

    Dientamoeba fragilis is a protozoan parasite of the human bowel, commonly reported throughout the world in association with gastrointestinal symptoms. Despite its initial discovery over 100 years ago, arguably, we know less about this peculiar organism than any other pathogenic or potentially pathogenic protozoan that infects humans. The details of its life cycle and mode of transmission are not completely known, and its potential as a human pathogen is debated within the scientific community. Recently, several major advances have been made with respect to this organism's life cycle and molecular biology. While many questions remain unanswered, these and other recent advances have given rise to some intriguing new leads, which will pave the way for future research. This review encompasses a large body of knowledge generated on various aspects of D. fragilis over the last century, together with an update on the most recent developments. This includes an update on the latest diagnostic techniques and treatments, the clinical aspects of dientamoebiasis, the development of an animal model, the description of a D. fragilis cyst stage, and the sequencing of the first D. fragilis transcriptome. PMID:27170141

  8. Metronidazole- and Carbapenem-Resistant Bacteroides thetaiotaomicron Isolated in Rochester, Minnesota, in 2014

    PubMed Central

    Sadarangani, Sapna P.; Cunningham, Scott A.; Jeraldo, Patricio R.; Wilson, John W.; Khare, Reeti

    2015-01-01

    Emerging antimicrobial resistance in members of the Bacteroides fragilis group is a concern in clinical medicine. Although metronidazole and carbapenem resistance have been reported in Bacteroides thetaiotaomicron, a member of the B. fragilis group, they have not, to the best of our knowledge, been reported together in the same B. thetaiotaomicron isolate. Herein, we report isolation of piperacillin-tazobactam-, metronidazole-, clindamycin-, ertapenem-, and meropenem-resistant B. thetaiotaomicron from a patient with postoperative intra-abdominal abscess and empyema. Whole-genome sequencing demonstrated the presence of nimD with at least a portion of IS1169 upstream, a second putative nim gene, two β-lactamase genes (one of which has not been previously reported), two tetX genes, tetQ, ermF, two cat genes, and a number of efflux pumps. This report highlights emerging antimicrobial resistance in B. thetaiotaomicron and the importance of identification and antimicrobial susceptibility testing of selected anaerobic bacteria. PMID:25941219

  9. Interaction of Bacteroides fragilis and Bacteroides thetaiotaomicron with the kallikrein–kinin system

    PubMed Central

    Mörgelin, Matthias; Cooney, Jakki C.; Frick, Inga-Maria

    2011-01-01

    Many bacterial pathogens interfere with the contact system (kallikrein–kinin system) in human plasma. Activation of this system has two consequences: cleavage of high-molecular-mass kininogen (HK) resulting in release of the potent proinflammatory peptide bradykinin, and initiation of the intrinsic pathway of coagulation. In this study, two species of the Gram-negative anaerobic commensal organism Bacteroides, namely Bacteroides fragilis and Bacteroides thetaiotaomicron, were found to bind HK and fibrinogen, the major clotting protein, from human plasma as shown by immunoelectron microscopy and Western blot analysis. In addition, these Bacteroides species were capable of activating the contact system at its surface leading to a significant prolongation of the intrinsic coagulation time and also to the release of bradykinin. Members of the genus Bacteroides have been known to act as opportunistic pathogens outside the gut, with B. fragilis being the most common isolate from clinical infections, such as intra-abdominal abscesses and bacteraemia. The present results thus provide more insight into how Bacteroides species cause infection. PMID:21527472

  10. Galaxies in extreme environments: Isolated galaxies versus compact groups

    NASA Astrophysics Data System (ADS)

    Durbala, Adriana

    2009-06-01

    This Dissertation comprises two distinct studies of galaxies in dramatically different environments: extreme isolation versus compact groups. We emphasize empirically how "nature" (i.e. internal, secular processes) plays the dominant role in defining the evolution of isolated galaxies and how "nurture" dictates the fate of galaxies in very crowded environments. Two chapters report on a detailed photometric study of a well-defined sample of N ~100 isolated Sb-Sc spiral galaxies. Data source is Sloan Digital Sky Survey. Using i-band images we perform three kinds of measures: (a) bulge/disk/bar decomposition, (b) CAS parametrization (Concentration, Asymmetry, Clumpiness), and (c) Fourier decomposition/analysis of spiral arms and bar properties including dynamical measures of the torque. Having quantified a large set of properties we look for: (i) the interplay between different components of the same galaxy, (ii) trends along the morphological sequence Sb-Sbc-Sc, and (iii) statistical differences between our "isolated" sample and samples of galaxies of similar morphology constructed without regard for isolation. We find that the majority of isolated late-type disk galaxies host pseudobulges rather than classical bulges. The pseudobulges probably form through internal secular processes and bars may play an important role. A clear separation is noted between Sb and Sbc/Sc in various measures, i.e. the former are redder, brighter, have larger disks and bars, more luminous bulges, are more concentrated, more symmetric and dumpier than the latter. Isolated galaxies host larger bars than galaxies in samples defined without isolation constraints. Longer bars are not necessarily stronger, but show a higher contrast in Fourier analysis. Another chapter is a multiwavelength study of Seyfert's Sextet, the highest density galaxy aggregate in the local Universe. Four of its five galaxies are interpreted as remnant bulges of accreted spirals and are now embedded in a luminous halo

  11. Internal character dictates transition dynamics between isolation and cohesive grouping

    NASA Astrophysics Data System (ADS)

    Manrique, Pedro D.; Hui, Pak Ming; Johnson, Neil F.

    2015-12-01

    We show that accounting for internal character among interacting heterogeneous entities generates rich transition behavior between isolation and cohesive dynamical grouping. Our analytical and numerical calculations reveal different critical points arising for different character-dependent grouping mechanisms. These critical points move in opposite directions as the population's diversity decreases. Our analytical theory may help explain why a particular class of universality is so common in the real world, despite the fundamental differences in the underlying entities. It also correctly predicts the nonmonotonic temporal variation in connectivity observed recently in one such system.

  12. The detection of two antigenic groups among Renibacterium salmoninarum isolates.

    PubMed

    Bandín, I; Santos, Y; Magariños, B; Barja, J L; Toranzo, A E

    1992-07-01

    The analysis of the membrane proteins and their antigenic properties in a group of 14 geographically diverse strains of Renibacterium salmoninarum revealed the existence of antigenic diversity within this species. Eleven isolates, including the type strain ATCC 33209, shared a similar protein profile with a major component of 57 kDa whereas three strains showed a common pattern with a major protein of 30 kDa. The quantitative agglutination tests and Western blotting assays seem to indicate the existence of serological heterogeneity, with two distinct groups being detected. PMID:1521757

  13. The enterotoxin of Bacteroides fragilis is a metalloprotease.

    PubMed Central

    Moncrief, J S; Obiso, R; Barroso, L A; Kling, J J; Wright, R L; Van Tassell, R L; Lyerly, D M; Wilkins, T D

    1995-01-01

    During the past decade, strains of Bacteroides fragilis that produce an enterotoxin have been implicated in diarrheal disease in animals and humans. The extracellular enterotoxin has been purified and characterized as a single polypeptide (M(r), approximately 20,000). Single specific primer-PCR was used to clone a portion of the B. fragilis enterotoxin gene. The recombinant protein expressed by the cloned gene fragment reacted with monospecific antibodies to B. fragilis enterotoxin by enzyme-linked immunosorbent assay and immunoblot analysis. The deduced amino acid sequence revealed a signature zinc-binding consensus motif (HEXXHXXGXXH/Met-turn) characteristic of metalloproteases termed metzincins. Sequence comparisons showed close identity to matrix metalloproteases (e.g., human fibroblast collagenase) within the zinc-binding and Met-turn region. Purified enterotoxin contained 1 g-atom of Zn2+ per molecule and hydrolyzed gelatin, azocoll, actin, tropomyosin, and fibrinogen. The enterotoxin also underwent autodigestion. The N-terminal amino acid sequences of two autodigestion products were identical to the deduced amino acid sequence of the recombinant enterotoxin and revealed cleavage at Cys-Leu and Ser-Leu peptide bonds. Gelatinase (type IV collagenase) activity comigrated with the toxin when analyzed by gel fractionation and zymography, indicating that protease activity is due to the enterotoxin and not to a contaminating protease(s). Optimal proteolytic activity occurred at 37 degrees C and pH 6.5. Primary proteolytic cleavage sites in actin were identified, revealing cleavage at Gly-Met and Thr-Leu peptide bonds. Enzymatic activity was inhibited by metal chelators but not by inhibitors of other classes of proteases. Additionally, cytotoxic activity of the enterotoxin on human carcinoma HT-29 cells was inhibited by acetoxymethyl ester EDTA. The metalloprotease activity of the enterotoxin suggests a possible mechanism for enterotoxicity and may have additional

  14. Dientamoeba fragilis prevalence coincides with gastrointestinal symptoms in children less than 11 years old in Sweden.

    PubMed

    Ögren, J; Dienus, O; Löfgren, S; Einemo, I-M; Iveroth, P; Matussek, A

    2015-10-01

    Dientamoeba fragilis is a protozoan with a debated role in gastrointestinal (GI) disease. Although correlated to GI symptoms, no virulence factors have been described. In this study, we evaluated the cause of GI symptoms in children at two schools, with children aged 1 to 10 years, in the county of Jönköping, Sweden. D. fragilis infection correlated to GI symptoms in children and Enterobius vermicularis correlated to D. fragilis infection. PMID:26173693

  15. Cloning and characterization of the Bacteroides fragilis metalloprotease toxin gene.

    PubMed Central

    Franco, A A; Mundy, L M; Trucksis, M; Wu, S; Kaper, J B; Sears, C L

    1997-01-01

    Strains of Bacteroides fragilis that produce a ca. 20-kDa heat-labile protein toxin (termed B. fragilis toxin [BFT]) have been associated with diarrheal disease of animals and humans. BFT alters the morphology of intestinal epithelial cells both in vitro and in vivo and stimulates secretion in ligated intestinal segments of rats, rabbits, and lambs. Previous genetic and biochemical data indicated that BFT was a metalloprotease which hydrolyzed G (monomeric) actin, gelatin, and azocoll in vitro. In this paper, the cloning and sequencing of the entire B. fragilis toxin gene (bft) from enterotoxigenic B. fragilis (ETBF) 86-5443-2-2 is reported. The bft gene from this ETBF strain consists of one open reading frame of 1,191 nucleotides encoding a predicted 397-residue holotoxin with a calculated molecular weight of 44,493. Comparison of the predicted BFT protein sequence with the N-terminal amino acid sequence of purified BFT indicates that BFT is most probably synthesized by ETBF strains as a preproprotein. These data predict that BFT is processed to yield a biologically active toxin of 186 residues with a molecular mass of 20.7 kDa which is secreted into the culture supernatant. Analysis of the holotoxin sequence predicts a 20-residue amphipathic region at the carboxy terminus of BFT. Thus, in addition to the metalloprotease activity of BFT, the prediction of an amphipathic domain suggests that oligomerization of BFT may permit membrane insertion of the toxin with creation of a transmembrane pore. Comparison of the sequences available for the bft genes from ETBF 86-5443-2-2 and VPI 13784 revealed two regions of reduced homology. Hybridization of oligonucleotide probes specific for each bft to toxigenic B.fragilis strains revealed that 51 and 49% of toxigenic strains contained the 86-5433-2-2 and VPI 13784 bft genes, respectively. No toxigenic strain hybridized with both probes. We propose that these two subtypes of bft be termed bft-1 (VPI 13784) and bft-2 (86

  16. Ribotyping of Lactobacillus casei group strains isolated from dairy products.

    PubMed

    Svec, P; Dráb, V; Sedlácek, I

    2005-01-01

    A series of lactobacilli isolated from dairy products were characterized using biotyping and ribotyping with EcoRI and HindIII restriction enzymes. Biotyping assigned 14 strains as Lactobacillus casei, 6 strains as Lactobacillus paracasei subsp. paracasei and 12 as Lactobacillus rhamnosus. The obtained ribotype patterns separated all analyzed strains into two clearly distinguished groups corresponding to L. rhamnosus and L. casei/L. paracasei subsp. paracasei. The HindIII ribotypes of individual strains representing these two groups were visually very similar. In contrast, EcoRI ribotyping revealed high intraspecies variability. All ribotypes of L. casei and L. paracasei subsp. paracasei dairy strains were very close and some strains even shared identical ribotype profiles. The type strains L. casei CCM 7088T (= ATCC 393T) and Lactobacillus zeae CCM 7069T revealing similar ribopatterns formed a separate subcluster using both restriction enzymes. In contrast, the ribotype profile of L. casei CCM 7089 (= ATCC 334) was very close to ribopatterns obtained from the dairy strains. These results support synonymy of L. casei and L. paracasei species revealed by other studies as well as reclassification of the type strain L. casei CCM 7088T as L. zeae and designation of L. casei CCM 7089 as the neotype strain. PMID:16295661

  17. Efficient isolation and identification of Bacillus cereus group.

    PubMed

    Tallent, Sandra M; Kotewicz, Kristin M; Strain, Errol A; Bennett, Reginald W

    2012-01-01

    Bacillus cereus is a group of ubiquitous facultative anaerobic sporeforming Gram-positive rods commonly found in soil. The spores frequently contaminate a variety of foods, including produce, meat, eggs, and dairy products. Foodborne illnesses associated with toxins produced by B. cereus can result in self-limiting diarrhea or vomiting. Plate enumeration methods recommended by recognized food authorities to detect the presence of B. cereus in potentially contaminated food products do not inhibit other Gram-positive competitive bacteria. This study evaluated the use of Bacara, a new chromogenic agar, as an efficient method to identify and enumerate B. cereus group from food matrixes, even in the presence of background flora. Inclusivity and exclusivity testing was performed using four different selective and differential media for B. cereus, including Mannitol Egg Yolk Polymyxin (MYP), Polymyxin Pyruvate Egg-Yolk Mannitol Bromothymol Blue Agar, Bacillus Chromogenic Media, Brilliance, and Bacara. MYP and Bacara were also used in plate enumeration studies to isolate B. cereus from artificially contaminated foods. PMID:22649932

  18. Bacteroides fragilis in biopsies of patients with major abscesses and diabetic foot infections: direct molecular versus culture-based detection.

    PubMed

    Stappers, Mark H T; Hagen, Ferry; Reimnitz, Peter; Mouton, Johan W; Meis, Jacques F; Gyssens, Inge C

    2016-06-01

    Direct determination by pathogen-specific real-time PCR assay for Bacteroides fragilis was compared to culture in major abscess and diabetic foot infection biopsy samples. Real-time PCR resulted in an increased detection rate of 12% for B. fragilis and could improve the detection of B. fragilis in clinical samples. PMID:27112830

  19. Bacteroides fragilis induce necrosis on mice peritoneal macrophages: In vitro and in vivo assays

    SciTech Connect

    Vieira, J.M.B.D.; Seabra, S.H.; Vallim, D.C.; Americo, M.A.; Fracallanza, S.E.L.; Vommaro, R.C.; Domingues, R.M.C.P.

    2009-10-02

    Bacteroides fragilis is an anaerobic bacteria component of human intestinal microbiota and agent of infections. In the host B. fragilis interacts with macrophages, which produces toxic radicals like NO. The interaction of activated mice peritoneal macrophages with four strains of B. fragilis was evaluated on this study. Previously was shown that such strains could cause metabolic and morphologic alterations related to macrophage death. In this work propidium iodide staining showed the strains inducing macrophage necrosis in that the labeling was evident. Besides nitroblue tetrazolium test showed that B. fragilis stimulates macrophage to produce oxygen radicals. In vivo assays performed in BalbC mice have results similar to those for in vitro tests as well as scanning electron microscopy, which showed the same surface pore-like structures observed in vitro before. The results revealed that B. fragilis strains studied lead to macrophage death by a process similar to necrosis.

  20. Physiological effects of environmental acidification in the deep-sea urchin Strongylocentrotus fragilis

    NASA Astrophysics Data System (ADS)

    Taylor, J. R.; Lovera, C.; Whaling, P. J.; Buck, K. R.; Pane, E. F.; Barry, J. P.

    2014-03-01

    Anthropogenic CO2 is now reaching depths over 1000 m in the Eastern Pacific, overlapping the Oxygen Minimum Zone (OMZ). Deep-sea animals are suspected to be especially sensitive to environmental acidification associated with global climate change. We have investigated the effects of elevated pCO2 and variable O2 on the deep-sea urchin Strongylocentrotus fragilis, a species whose range of 200-1200 m depth includes the OMZ and spans a pCO2 range of approx. 600-1200 μatm (approx. pH 7.6 to 7.8). Individuals were evaluated during two exposure experiments (1-month and 4 month) at control and three levels of elevated pCO2 at in situ O2 levels of approx. 10% air saturation. A treatment of control pCO2 at 100% air saturation was also included in experiment two. During the first experiment, perivisceral coelomic fluid (PCF) acid-base balance was investigated during a one-month exposure; results show S. fragilis has limited ability to compensate for the respiratory acidosis brought on by elevated pCO2, due in part to low non-bicarbonate PCF buffering capacity. During the second experiment, individuals were separated into fed and fasted experimental groups, and longer-term effects of elevated pCO2 and variable O2 on righting time, feeding, growth, and gonadosomatic index (GSI) were investigated for both groups. Results suggest that the acidosis found during experiment one does not directly correlate with adverse effects during exposure to realistic future pCO2 levels.

  1. Cloning and characterization of the endogenous cephalosporinase gene, cepA, from Bacteroides fragilis reveals a new subgroup of Ambler class A beta-lactamases.

    PubMed Central

    Rogers, M B; Parker, A C; Smith, C J

    1993-01-01

    Bacteroides fragilis CS30 is a clinical isolate resistant to high concentrations of benzylpenicillin and cephaloridine but not to cephamycin or penem antibiotics. beta-Lactam resistance is mediated by a chromosomally encoded cephalosporinase produced at a high level. The gene encoding this beta-lactamase was cloned from genomic libraries constructed in Escherichia coli and then mated with B. fragilis 638 for identification of ampicillin-resistant (Apr) strains. Apr transconjugants contained a nitrocefin-reactive protein with the physical and enzymatic properties of the original CS30 isolate. The beta-lactamase gene (cepA) was localized by deletion analysis and subcloned, and its nucleotide sequence was determined. The 903-bp cepA open reading frame encoded a 300-amino-acid precursor protein (predicted molecular mass, 34,070 Da). A beta-lactamase-deficient mutant strain of B. fragilis 638 was constructed by insertional inactivation with the cepA gene of CS30, demonstrating strict functional homology between these chromosomal beta-lactamase genes. An extensive comparison of the CepA protein sequence by alignment with other beta-lactamases revealed the strict conservation of at least four elements common to Ambler class A. A further comparison of the CepA protein sequence with protein sequences of beta-lactamases from two other Bacteroides species indicated that they constitute their own distinct subgroup of class A beta-lactamases. Images PMID:8285623

  2. Peptide Sequence Region That is Essential for the Interactions of the Enterotoxigenic Bacteroides fragilis Metalloproteinase II with E-cadherin

    PubMed Central

    Shiryaev, Sergey A.; Remacle, Albert G.; Cieplak, Piotr; Strongin, Alex Y.

    2015-01-01

    Bacteroides fragilis is a valuable anaerobic commensal and an essential component of the gut microbiome in humans. The presence of a short pathogenicity island in the genome is predominantly associated with the enterotoxigenic strains of B. fragilis. Metallopro-teinase II (MPII) and fragilysin (FRA) are the structurally related enzymes encoded by the pathogenicity island in the enterotoxigenic strains. Accordingly, there is a significant overlap between the cleavage preferences of MPII and FRA. These proteinases, however, are counter-transcribed in the bacterial genome suggesting their distinct and specialized functions in the course of infection. It is well established that FRA directly cleaves E-cadherin, a key protein of the cell-to-cell adhesion junctions in the intestinal epithelium. Counterintuitively, MPII directly binds to, rather than cleaves, E-cadherin. Structural modeling suggested that a potential E-cadherin binding site involves the C-terminal -helical region of the MPII catalytic domain. The sequence of this region is different in MPII and FRA. Here, we employed substitution mutagenesis of this C-terminal -helical region to isolate the MPII mutants with the potentially inactivated E-cadherin binding site. Overall, as a result of our modeling, mutagenesis and binding studies, we determined that the C-terminal ten residue segment is essential for the binding of MPII, but not of FRA3, to E-cadherin, and that the resulting MPII•E-cadherin complex does not impair E-cadherin-dependent cell-to-cell contacts. It is possible to envision that the putative cleavage targets of MPII should be explored not only on the host cell surface but also in B. fragilis. PMID:25964952

  3. [Susceptibilities of clinical bacterial isolates to antimicrobial agents. A study mainly focused on imipenem. Reported by the Research Group for Testing Imipenem Susceptibility on Clinical Isolates].

    PubMed

    Igari, J

    1990-11-01

    This study was conducted to investigate susceptibilities of clinical bacterial isolates to imipenem (IPM) and other antibacterial agents at 64 hospital laboratories throughout Japan from September to December of 1988. In this study, identification and susceptibility testing were carried out at each laboratory and the tests were performed according to the disk dilution method recommended by NCCLS in which susceptibilities are classified into "S", "MS", "I" and "R". IPM showed markedly high in vitro activities against Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, Enterococcus faecalis, Haemophilus influenzae, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae, Serratia marcescens, Salmonella spp., Citrobacter freundii, Proteus mirabilis, Proteus vulgaris, Morganella morganii, Providencia rettgeri, Providencia stuartii, Acinetobacter calcoaceticus, Moraxella (Branhamella) catarrhalis, Alcaligenes spp., Peptococcus spp./Peptostreptococcus spp., Bacteroides fragilis and Bacteroides spp. IPM also had strong activities against Achromobacter xylosoxidans and Pseudomonas aeruginosa, but less active against Flavobacterium spp., E. faecium, coagulase-negative staphylococci (CNS), Staphylococcus aureus and Pseudomonas cepacia. In a study in which activities of IPM against bacteria isolated from different clinical sources were compared, differences in susceptibilities were observed among S. aureus, CNS, A. calcoaceticus and P. aeruginosa, but such differences were not apparent among S. pneumoniae, E. faecalis, H. influenzae, E. coli, K. pneumoniae, E. cloacae, C. freundii, S. marcescens or P. mirabilis. PMID:2287060

  4. History of antimicrobial use and the risk of Dientamoeba fragilis infection.

    PubMed

    Röser, D; Simonsen, J; Nielsen, H V; Stensvold, C R; Mølbak, K

    2015-06-01

    Associations between antimicrobial use and risk of enteric infection with intestinal protozoa are scarcely studied. The aim of this study was to quantify the risk of Dientamoeba fragilis infection conferred by exposure to antimicrobials. We conducted a registry-based retrospective cohort study of 9,945 Danish patients investigated for D. fragilis infection between 2008 and 2011, using data from the Danish Register of Medicinal Product Statistics, and calculating relative risks (RR) for D. fragilis infection by stratified binary regression. Furthermore, we conducted a population based case-control study using controls sampled from the Danish Civil Registration System, calculating hazard ratios (HR) for D. fragilis infection by conditional logistic regression. Exposure to metronidazole was found to confer decreased risk of D. fragilis infection; however, similar associations were found for antimicrobials not commonly used to treat D. fragilis, such as broad-spectrum penicillin, fluoroquinolones, and macrolides. In contrast, mebendazole exposure was associated with increased risk. The intake of antimicrobials influences the risk of D. fragilis. PMID:25663130

  5. A zymodeme study of Entamoeba histolytica in a group of South African schoolchildren.

    PubMed

    Sargeaunt, P G; Williams, J E; Jackson, T F; Simjee, A E

    1982-01-01

    Using a biphasic culture medium, stocks of intestinal amoebae were isolated from a group of children attending school in Durban, South Africa. These were compared with stocks collected in other areas of the world already characterized using the electrophoretic patterns of four enzymes: glucose phosphate isomerase (GPI), phosphoglucomutase (PGM) L-malate: NADP+ oxido-reductase (oxalacetate-decarboxylating) (ME) and hexokinase (HK). 33% of 94 samples grew Entamoeba histolytica, only one of which gave a pattern indicative of a pathogenic stock. Entamoeba hartmanni, Dientamoeba fragilis and Entamoeba coli were also grown from some samples, increasing the total positive samples for all species isolated to 40%. PMID:6287686

  6. Comparison of Hemagglutination and Hemolytic Activity of Various Bacterial Clinical Isolates Against Different Human Blood Groups

    PubMed Central

    HRV, Rajkumar; Devaki, Ramakrishna

    2016-01-01

    Among the various pathogenic determinants shown by microorganisms hemagglutination and hemolysin production assume greater significance in terms of laboratory identification. This study evaluated the hemagglutination and hemolytic activity of various bacterial isolates against different blood groups. One hundred and fifty bacterial strains, isolated from clinical specimens like urine, pus, blood, and other body fluids were tested for their hemagglutinating and hemolytic activity against human A, B, AB, and O group red blood cells. Among the 150 isolates 81 were Escherichia coli, 18 were Klebsiella pneumoniae, 19 were Pseudomonas aeruginosa, 10 were Pseudomonas spp, six were Proteus mirabilis, and the rest 16 were Staphylococcus aureus. Nearly 85% of the isolates agglutinated A group cells followed by B and AB group (59.3% and 60.6% respectively). Least number of isolates agglutinated O group cells (38.0%). When the hemolytic activity was tested, out of these 150 isolates 79 (52.6%) hemolyzed A group cells, 61 (40.6%) hemolyzed AB group cells, 46 (30.6%) hemolyzed B group cells, and 57 (38.6%) isolates hemolyzed O group cells. Forty-six percent of the isolates exhibited both hemagglutinating and hemolytic property against A group cells, followed by B and AB group cells (28.6% and 21.3% respectively). Least number of isolates i.e., 32 (21.3%) showed both the properties against O group cells. The isolates showed wide variation in their hemagglutination and hemolytic properties against different combinations of human blood group cells. The study highlights the importance of selection of the type of cells especially when human RBCs are used for studying the hemagglutination and hemolytic activity of bacterial isolates because these two properties are considered as characteristic of pathogenic strains. PMID:27014523

  7. Comparison of Hemagglutination and Hemolytic Activity of Various Bacterial Clinical Isolates Against Different Human Blood Groups.

    PubMed

    Hrv, Rajkumar; Devaki, Ramakrishna; Kandi, Venkataramana

    2016-01-01

    Among the various pathogenic determinants shown by microorganisms hemagglutination and hemolysin production assume greater significance in terms of laboratory identification. This study evaluated the hemagglutination and hemolytic activity of various bacterial isolates against different blood groups. One hundred and fifty bacterial strains, isolated from clinical specimens like urine, pus, blood, and other body fluids were tested for their hemagglutinating and hemolytic activity against human A, B, AB, and O group red blood cells. Among the 150 isolates 81 were Escherichia coli, 18 were Klebsiella pneumoniae, 19 were Pseudomonas aeruginosa, 10 were Pseudomonas spp, six were Proteus mirabilis, and the rest 16 were Staphylococcus aureus. Nearly 85% of the isolates agglutinated A group cells followed by B and AB group (59.3% and 60.6% respectively). Least number of isolates agglutinated O group cells (38.0%). When the hemolytic activity was tested, out of these 150 isolates 79 (52.6%) hemolyzed A group cells, 61 (40.6%) hemolyzed AB group cells, 46 (30.6%) hemolyzed B group cells, and 57 (38.6%) isolates hemolyzed O group cells. Forty-six percent of the isolates exhibited both hemagglutinating and hemolytic property against A group cells, followed by B and AB group cells (28.6% and 21.3% respectively). Least number of isolates i.e., 32 (21.3%) showed both the properties against O group cells. The isolates showed wide variation in their hemagglutination and hemolytic properties against different combinations of human blood group cells. The study highlights the importance of selection of the type of cells especially when human RBCs are used for studying the hemagglutination and hemolytic activity of bacterial isolates because these two properties are considered as characteristic of pathogenic strains. PMID:27014523

  8. [Susceptibilities of clinical bacterial isolates to antimicrobial agents. A study mainly focused on imipenem. Research Group for Testing Imipenem Susceptibility on Clinical Isolates].

    PubMed

    Igari, J

    1990-10-01

    We investigated susceptibilities of clinical bacterial isolates to imipenem (IPM) and other antimicrobial agents at 459 hospital laboratories throughout Japan from September to December of 1988. In this study, identification and susceptibility testing were performed at each hospital laboratory and the tests were carried out according to the 1-dilution or 3-dilution disc technique in which susceptibilities are classified into 4 grades: , ++, + and -. IPM had significantly high activity against Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, Neisseria gonorrhoeae, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae, Salmonella spp., Citrobacter freundii, Proteus mirabilis, Providencia rettgeri, Acinetobacter calcoaceticus, Moraxella catarrhalis, Alcaligenes spp., Peptococcus spp./Peptostreptococcus spp., Bacteroides fragilis and Bacteroides spp. and should slightly lower activities on coagulase-negative staphylococci (CNS), Enterococcus faecalis, Haemophilus influenzae, Serratia marcescens, Proteus vulgaris, Providencia stuartii and Pseudomonas aeruginosa than on the above mentioned bacteria. In a comparative study on activities of IPM against bacteria from different clinical sources, no remarkable differences were found due to different sources among S. pneumoniae, E. faecalis, H. influenzae, E. coli, K. pneumoniae, E. cloacae, C. freundii, P. mirabilis or A. calcoaceticus, whereas slight differences were found among Staphylococcus aureus, CNS, S. marcescens and P. aeruginosa. PMID:2086814

  9. Social Interaction and Isolation Among a Group of Elderly Blacks.

    ERIC Educational Resources Information Center

    Heisel, Marsel A.

    Presented in this paper is a study undertaken to determine the level of social interaction and isolation in a randomly selected sample of 156 aged blacks in an urban area of New Jersey. The interaction patterns are analyzed in terms of availability, relations with, and reactions toward close and distant relatives and friends. The relation between…

  10. Is paromomycin the drug of choice for eradication of Dientamoeba fragilis in adults?

    PubMed Central

    van Hellemond, Jaap J.; Molhoek, Nicky; Koelewijn, Rob; Wismans, Pieter J.; van Genderen, Perry J.J.

    2012-01-01

    Dientamoeba fragilis is a debated protozoan parasite that is often detected in stools of patients with chronic gastro-intestinal complaints. A retrospective follow-up study of a large cohort of patients was performed to better understand the natural course of the infection and possible treatment options. D. fragilis was spontaneously cleared in 41% of untreated cases. With an eradication rate of 98%, treatment with paromomycin appeared more effective than treatment with clioquinol (83%) or metronidazole (57%). PMID:24533277

  11. Detection of Dientamoeba fragilis in animal faeces using species specific real time PCR assay.

    PubMed

    Chan, Douglas; Barratt, Joel; Roberts, Tamalee; Phillips, Owen; Šlapeta, Jan; Ryan, Una; Marriott, Deborah; Harkness, John; Ellis, John; Stark, Damien

    2016-08-30

    Dientamoeba fragilis is a potentially pathogenic, enteric, protozoan parasite with a worldwide distribution. While clinical case reports and prevalence studies appear regularly in the scientific literature, little attention has been paid to this parasite's biology, life cycle, host range, and possible transmission routes. Overall, these aspects of Dientamoeba biology remain poorly understood at best. In this study, a total of 420 animal samples, collected from Australia, were surveyed for the presence of Dientamoeba fragilis using PCR. Several PCR assays were evaluated for sensitivity and specificity. Two previously published PCR methods demonstrated cross reactivity with other trichomonads commonly found in animal samples. Only one assay exhibited excellent specificity. Using this assay D. fragilis was detected from one dog and one cat sample. This is the first report of D. fragilis from these animals and highlights the role companion animals may play in D. fragilis transmission. This study demonstrated that some published D. fragilis molecular assays cross react with other closely related trichomonads and consequently are not suitable for animal prevalence studies. PMID:27523936

  12. Cytologic and Genetic Characteristics of Endobiotic Bacteria and Kleptoplasts of Virgulinella fragilis (Foraminifera).

    PubMed

    Tsuchiya, Masashi; Toyofuku, Takashi; Uematsu, Katsuyuki; Brüchert, Volker; Collen, John; Yamamoto, Hiroyuki; Kitazato, Hiroshi

    2015-01-01

    The benthic foraminifer Virgulinella fragilis Grindell and Collen 1976 has multiple putative symbioses with both bacterial and kleptoplast endobionts, possibly aiding its survival in environments from dysoxia (5-45 μmol-O2 /L) to microxia (0-5 μmol-O2 /L) and in the dark. To clarify the origin and function of V. fragilis endobionts, we used genetic analyses and transmission electron microscope observations. Virgulinella fragilis retained δ-proteobacteria concentrated at its cell periphery just beneath the cell membranes. Unlike another foraminifer Stainforthia spp., which retains many bacterial species, V. fragilis has a less variable bacterial community. This suggests that V. fragilis maintains a specific intracellular bacterial flora. Unlike the endobiotic bacteria, V. fragilis klepto-plasts originated from various diatom species and are found in the interior cytoplasm. We found evidence of both retention and digestion of kleptoplasts, and of fragmentation of the kleptoplastid outer membrane that likely facilitates transport of kleptoplastid products to the host. Accumulations of mitochondria were observed encircling endobiotic bacteria. It is likely that the bacteria use host organic material for carbon oxidation. The mitochondria may use oxygen available around the δ-proteobacteria and synthesize adenosine triphosphate, perhaps for sulfide oxidation. PMID:25510528

  13. Antigenic cross-reactivity among isolates of group JK corynebacteria.

    PubMed

    Moore, M K; Chaudhry, S; Noble, W C

    1990-08-01

    Using rocket and rocket-line immunoelectrophoresis and immunoblotting it was demonstrated that a group of antibiotic-resistant bacteria, including several authenticated Corynebacterium jeikeium strains, shared many cross-reacting antigens. Only weak cross-reactivity was demonstrated with representatives of three other skin corynebacteria, C. bovis, C. hofmanii and C. minutissimum or with non-coryneforms. Differences within C. jeikeium are sufficient to permit the use of immunoblotting as an epidemiological tool. PMID:1976676

  14. Comparison of the pathogenicity of porcine circovirus type 2 group 1 and group 2 isolates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    1. Introduction and Objectives Phylogenetically, porcine circovirus type 2 (PCV2) can be divided into two major genotypic groups, PCV2-group 1 and PCV2-group 2 .1 It was noted that PCV2 group designations have no apparent association with disease status or geographic area. Interestingly, all of t...

  15. Genomic Diversity of Enterotoxigenic Strains of Bacteroides fragilis.

    PubMed

    Pierce, Jessica V; Bernstein, Harris D

    2016-01-01

    Enterotoxigenic (ETBF) strains of Bacteroides fragilis are the subset of strains that secrete a toxin called fragilysin (Bft). Although ETBF strains are known to cause diarrheal disease and have recently been associated with colorectal cancer, they have not been well characterized. By sequencing the complete genome of four ETBF strains, we found that these strains exhibit considerable variation at the genomic level. Only a small number of genes that are located primarily in the Bft pathogenicity island (BFT PAI) and the flanking CTn86 conjugative transposon are conserved in all four strains and a fifth strain whose genome was previously sequenced. Interestingly, phylogenetic analysis strongly suggests that the BFT PAI was acquired by non-toxigenic (NTBF) strains multiple times during the course of evolution. At the phenotypic level, we found that the ETBF strains were less fit than the NTBF strain NCTC 9343 and were susceptible to a growth-inhibitory protein that it produces. The ETBF strains also showed a greater tendency to form biofilms, which may promote tumor formation, than NTBF strains. Although the genomic diversity of ETBF strains raises the possibility that they vary in their pathogenicity, our experimental results also suggest that they share common properties that are conferred by different combinations of non-universal genetic elements. PMID:27348220

  16. Genomic Diversity of Enterotoxigenic Strains of Bacteroides fragilis

    PubMed Central

    Pierce, Jessica V.; Bernstein, Harris D.

    2016-01-01

    Enterotoxigenic (ETBF) strains of Bacteroides fragilis are the subset of strains that secrete a toxin called fragilysin (Bft). Although ETBF strains are known to cause diarrheal disease and have recently been associated with colorectal cancer, they have not been well characterized. By sequencing the complete genome of four ETBF strains, we found that these strains exhibit considerable variation at the genomic level. Only a small number of genes that are located primarily in the Bft pathogenicity island (BFT PAI) and the flanking CTn86 conjugative transposon are conserved in all four strains and a fifth strain whose genome was previously sequenced. Interestingly, phylogenetic analysis strongly suggests that the BFT PAI was acquired by non-toxigenic (NTBF) strains multiple times during the course of evolution. At the phenotypic level, we found that the ETBF strains were less fit than the NTBF strain NCTC 9343 and were susceptible to a growth-inhibitory protein that it produces. The ETBF strains also showed a greater tendency to form biofilms, which may promote tumor formation, than NTBF strains. Although the genomic diversity of ETBF strains raises the possibility that they vary in their pathogenicity, our experimental results also suggest that they share common properties that are conferred by different combinations of non-universal genetic elements. PMID:27348220

  17. Lichens promote flowering Opuntia fragilis in west-central Wisconsin

    USGS Publications Warehouse

    Bennett, J.P.; Bornar, C.R.; Harrington, C.A.

    2003-01-01

    Clumps of the cactus Opuntia fragilis growing in association with mats of the lichens Cladina mitis, Cladina rangiferina and a spikemoss, Selaginella rupestris, were discovered in an agricultural field in Pepin County, Wisconsin, that had been abandoned for over 50 y. The association appeared to be beneficial to the cactus, which flowered almost exclusively in the presence of lichens. Of 294 cactus clumps examined in 2001, 127 grew in the presence of lichen mats and, of these, 24 flowered, producing 91 flowers, while none of the cacti growing in the absence of lichens flowered. In 2002, 19 out of 265 cactus clumps flowered, all but one in the presence of lichens. All sizes of cacti in the presence of lichens flowered and the probability of flowering increased with cactus size. In addition, the cacti that flowered had cladodes that were on average 19% heavier than those of cacti that did not flower. The presence of lichens lowered summer soil temperatures 2a??4 C compared to soil temperatures in the absence of lichens. Cooler soil temperatures conserve soil moisture better, which may enhance flowering in these cacti.

  18. [Production of Kluyveromices fragilis biomass in deproteinized milk whey].

    PubMed

    Chinappi, I; Sánchez Crispín, J A

    2000-01-01

    The milk whey from a mature cheese factory deproteinised by acid thermic coagulation (pH 4.5 and 90 degrees C), provides a good culture media for the production of Kluyveromices fragilis biomass. The optimal experimental conditions for the maximal production of biomass were established by using fermenters with different capacity and design. For lactose concentration of 15 g/l, pH 4.5, 30 degrees C and aireation between 0.25 and 1 VVM, the duplication time was below two hours and 98% of the lactose was consumed. The obtained yield in dried weight was between 36 and 49% (g biomass/g lactose). The biomass (without broken cell) contain 46% protein on dry base and showed an "in vitro" digestibility of 65%. The organic mass decreased 80% after 12 hour of fermentation. This process eliminates a polluting agent and simultaneously, produces a biomass that could have industrial use as a protein complement in feeds. PMID:11460792

  19. Phylogenetic grouping, epidemiological typing, analysis of virulence genes, and antimicrobial susceptibility of Escherichia coli isolated from healthy broilers in Japan

    PubMed Central

    2014-01-01

    Background The aim of our study was to investigate the possible etiology of avian colibacillosis by examining Escherichia coli isolates from fecal samples of healthy broilers. Findings Seventy-eight E. coli isolates from fecal samples of healthy broilers in Japan were subjected to analysis of phylogenetic background, virulence-associated gene profiling, multi-locus sequence typing (MLST), and antimicrobial resistance profiling. Phylogenetic analysis demonstrated that 35 of the 78 isolates belonged to group A, 28 to group B1, one to group B2, and 14 to group D. Virulence-associated genes iutA, iss, cvaC, tsh, iroN, ompT, and hlyF were found in 23 isolates (29.5%), 16 isolates (20.5%), nine isolates (11.5%), five isolates (6.4%), 19 isolates (24.4%), 23 isolates (29.5%), and 22 isolates (28.2%) respectively. Although the genetic diversity of group D isolates was revealed by MLST, the group D isolates harbored iutA (10 isolates, 71.4%), iss (6 isolates, 42.9%), cvaC (5 isolates, 35.7%), tsh (3 isolates, 21.4%), hlyF (9 isolates, 64.3%), iroN (7 isolates, 50.0%), and ompT (9 isolates, 64.3%). Conclusions Our results indicated that E. coli isolates inhabiting the intestines of healthy broilers pose a potential risk of causing avian colibacillosis. PMID:25061511

  20. New Insertion Sequence Elements in the Upstream Region of cfiA in Imipenem-Resistant Bacteroides fragilis Strains

    PubMed Central

    Kato, Naoki; Yamazoe, Kikuo; Han, Chang-Gyun; Ohtsubo, Eiichi

    2003-01-01

    The 747-bp cfiA gene, which encodes a metallo-β-lactamase, and the regions flanking cfiA in six imipenem-resistant and four imipenem-susceptible Bacteroides fragilis strains isolated in Japan were analyzed by PCR and DNA sequencing. The nucleotide sequences of the cfiA genes (designated cfiA1 to cfiA10) of all 10 strains tested varied from that of the standard cfiA gene from B. fragilis TAL2480. However, putative proteins encoded by the cfiA variants contained conserved amino acid residues important for zinc binding and hairpin loop formation, suggesting that cfiA variants have the capability of producing metallo-β-lactamases with full catalytic activities. PCR assay indicated that six metallo-β-lactamase-producing, imipenem-resistant strains had an insertion mutation in the region immediately upstream of cfiA. Nucleotide sequencing of the PCR-amplified fragments along with the upstream region of cfiA revealed that there were five new kinds of insertion sequence (IS) elements (designated IS612, IS613, IS614, IS615, and IS616, with a size range of 1,594 to 1,691 bp), of which only IS616 was found to be almost identical to IS1188, one of the IS elements previously identified in the upstream region of cfiA. These elements had target site duplications of 4 or 5 bp in length, terminal inverted repeats (14, 15, or 17 bp in size), and a large open reading frame encoding a putative transposase which is required for the transcription of IS elements. Each element was inserted such that the transcriptional direction of the transposase was opposite to that of cfiA. A computer-aided homology search revealed that, based on the homology of their putative transposases, the sizes of their terminal inverted repeat sequences, and their target site duplications, IS612, IS613, IS614, and IS615 belong to the IS4 family, which includes IS942, previously found in some drug-resistant B. fragilis strains, but that IS616 belongs to the IS1380 family. All the IS elements appear to have

  1. Emerging from Obscurity: Biological, Clinical, and Diagnostic Aspects of Dientamoeba fragilis

    PubMed Central

    Johnson, Eugene H.; Windsor, Jeffrey J.; Clark, C. Graham

    2004-01-01

    Ever since its first description in 1918, Dientamoeba fragilis has struggled to gain recognition as a significant pathogen. There is little justification for this neglect, however, since there exists a growing body of case reports from numerous countries around the world that have linked this protozoal parasite to clinical manifestations such as diarrhea, abdominal pain, flatulence, and anorexia. A number of studies have even incriminated D. fragilis as a cause of irritable bowel syndrome, allergic colitis, and diarrhea in human immunodeficiency virus patients. Although D. fragilis is most commonly identified using permanently stained fecal smears, recent advances in culturing techniques are simplifying as well as improving the ability of investigators to detect this organism. However, there are limitations in the use of cultures since they cannot be performed on fecal samples that have been fixed. Significant progress has been made in the biological classification of this organism, which originally was described as an ameba. Analyses of small-subunit rRNA gene sequences have clearly demonstrated its close relationship to Histomonas, and it is now known to be a trichomonad. How the organism is transmitted remains a mystery, although there is some evidence that D. fragilis might be transmitted via the ova of the pinworm, Enterobius vermicularis. Also, it remains to be answered whether the two distinct genotypes of D. fragilis recently identified represent organisms with differing virulence. PMID:15258093

  2. Structural and functional diversity of metalloproteinases encoded by the Bacteroides fragilis pathogenicity island

    PubMed Central

    Shiryaev, Sergey A.; Aleshin, Alexander E.; Muranaka, Norihito; Kukreja, Muskan; Routenberg, David A.; Remacle, Albert G.; Liddington, Robert C.; Cieplak, Piotr; Kozlov, Igor A.; Strongin, Alex Y.

    2014-01-01

    Summary Bacteroides fragilis causes the majority of anaerobic infections in humans. The presence of a pathogenicity island in the genome discriminates pathogenic and commensal B. fragilis strains. The island encodes metalloproteinase II (MPII), a potential virulence protein, and one of three homologous fragilysin isozymes (FRA; also termed B. fragilis toxin or BFT). Here, we report biochemical data on the structural-functional characteristics of the B. fragilis pathogenicity island proteases by reporting the crystal structure of MPII at 2.13 Å resolution combined with detailed characterization of the cleavage preferences of MPII and FRA3 (as a representative of the FRA isoforms) identified using a high-throughput peptide cleavage assay with 18,583 substrate peptides. We suggest that the evolution of the MPII catalytic domain can be traced to human and archaebacterial proteinases, while the prodomain fold is a feature specific to MPII and FRA. We conclude that the catalytic domain of both MPII and FRA3 evolved differently relative to the prodomain, and that the prodomain evolved specifically to fit the B. fragilis pathogenicity. Overall, our data provide insights into the evolution of cleavage specificity and activation mechanisms in the virulent metalloproteinases. PMID:24698179

  3. Emerging from obscurity: biological, clinical, and diagnostic aspects of Dientamoeba fragilis.

    PubMed

    Johnson, Eugene H; Windsor, Jeffrey J; Clark, C Graham

    2004-07-01

    Ever since its first description in 1918, Dientamoeba fragilis has struggled to gain recognition as a significant pathogen. There is little justification for this neglect, however, since there exists a growing body of case reports from numerous countries around the world that have linked this protozoal parasite to clinical manifestations such as diarrhea, abdominal pain, flatulence, and anorexia. A number of studies have even incriminated D. fragilis as a cause of irritable bowel syndrome, allergic colitis, and diarrhea in human immunodeficiency virus patients. Although D. fragilis is most commonly identified using permanently stained fecal smears, recent advances in culturing techniques are simplifying as well as improving the ability of investigators to detect this organism. However, there are limitations in the use of cultures since they cannot be performed on fecal samples that have been fixed. Significant progress has been made in the biological classification of this organism, which originally was described as an ameba. Analyses of small-subunit rRNA gene sequences have clearly demonstrated its close relationship to Histomonas, and it is now known to be a trichomonad. How the organism is transmitted remains a mystery, although there is some evidence that D. fragilis might be transmitted via the ova of the pinworm, Enterobius vermicularis. Also, it remains to be answered whether the two distinct genotypes of D. fragilis recently identified represent organisms with differing virulence. PMID:15258093

  4. Structural and functional diversity of metalloproteinases encoded by the Bacteroides fragilis pathogenicity island.

    PubMed

    Shiryaev, Sergey A; Aleshin, Alexander E; Muranaka, Norihito; Kukreja, Muskan; Routenberg, David A; Remacle, Albert G; Liddington, Robert C; Cieplak, Piotr; Kozlov, Igor A; Strongin, Alex Y

    2014-06-01

    Bacteroides fragilis causes the majority of anaerobic infections in humans. The presence of a pathogenicity island in the genome discriminates pathogenic and commensal B. fragilis strains. The island encodes metalloproteinase II (MPII), a potential virulence protein, and one of three homologous fragilysin isozymes (FRA; also termed B. fragilis toxin or BFT). Here, we report biochemical data on the structural-functional characteristics of the B. fragilis pathogenicity island proteases by reporting the crystal structure of MPII at 2.13 Å resolution, combined with detailed characterization of the cleavage preferences of MPII and FRA3 (as a representative of the FRA isoforms), identified using a high-throughput peptide cleavage assay with 18 583 substrate peptides. We suggest that the evolution of the MPII catalytic domain can be traced to human and archaebacterial proteinases, whereas the prodomain fold is a feature specific to MPII and FRA. We conclude that the catalytic domain of both MPII and FRA3 evolved differently relative to the prodomain, and that the prodomain evolved specifically to fit the B. fragilis pathogenicity. Overall, our data provide insights into the evolution of cleavage specificity and activation mechanisms in the virulent metalloproteinases. PMID:24698179

  5. [Bacteria isolated from surgical infections and its susceptibilities to antimicrobial agents--special references to bacteria isolated between April 2003 and March 2004].

    PubMed

    Shinagawa, Nagao; Taniguchi, Masaaki; Hirata, Koichi; Katsuramaki, Tadashi; Mizukuchi, Tohru; Mashita, Keiji; Ushijima, Yasuhide; Ushida, Tomohiro; Ishikawa, Syu; Aikawa, Naoki; Yo, Kikuo; Mizuno, Akira; Takayama, Tadatoshi; Sato, Takeshi; Kato, Koumei; Kubo, Shoji; Suehiro, Shigefumi; Yura, Jiro; Fujimoto, Mikio; Manabe, Tadao; Takeyama, Hiromitsu; Tanimura, Hiroshi; Taniguchi, Katsutoshi; Hasegawa, Masamitsu; Yamaue, Hiroki; Ohnishi, Hironobu; Tanaka, Noriaki; Iwagaki, Hiromi; Kimura, Hideyuki; Tsumura, Hiroaki; Fuchimoto, Sadayoshi; Yokoyama, Takashi; Sueda, Taijiro; Takesue, Yoshio; Takeuchi, Hitoshi; Yasui, Yoshimasa; Hiyama, Eizo; Ikeda, Seiyo; Yasunami, Yoichi

    2006-04-01

    Tendency of isolated bacteria from infections in general surgery during the period from April 2004 to March 2005 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, 645 strains including 17 strains of Candida spp. were isolated from 226 (79.0%) of 286 patients with surgical infections. Three hundred and seventeen strains were isolated from primary infections, and 345 strains were isolated from postoperative infections. From primary infections, anaerobic Gram-positive bacteria and anaerobic Gram-negative bacteria were predominant, while aerobic Gram-positive bacteria were predominant from postoperative infections. The isolation rate of aerobic Gram-positive bacteria, such as Enterococcus spp. and Staphylococcus aureus were higher from both types of infections. Among anaerobic Gram-positive bacteria, the isolation rate of Peptostreptococcus spp. was the highest from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Pseudomonas aeruginosa, Klebsiella pneumoniae and Citrobacter freundii in this order, and from postoperative infections, P. aeruginosa was the most predominantly isolated, followed by E. coli, E. cloacae, and K. pneumoniae. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both primary infections followed by Bilophila wadsworthia. While the isolation rate of B. fragilis group was also the highest from postoperative infections, the following bacteria were Bacteroides thetaiotaomicron and B. wadsworthia in this order. In this series, we noticed no vancomycin-resistant Gram-positive cocci, but a few strains of moderately arbekacin-resistant MRSA. Carbapenem-resistant P. aeruginosa but not multidrug-resistant was seen in 13.3 per cents. Also cefazolin-resistant E. coli probably producing extended spectrum beta-lactamase was seen in 7.0 per

  6. Metabolism of a 5-nitroimidazole in susceptible and resistant isogenic strains of Bacteroides fragilis.

    PubMed Central

    Carlier, J P; Sellier, N; Rager, M N; Reysset, G

    1997-01-01

    We investigated the metabolism of dimetridazole (1,2-dimethyl-5-nitroimidazole) (DMZ) by the resting cell method in a susceptible strain of Bacteroides fragilis and in the same strain containing the nimA gene, which conferred resistance to 5-nitroimidazole drugs. In both cases, under strict anaerobic conditions DMZ was metabolized without major ring cleavage or nitrate formation. However, one of two distinct metabolic pathways is involved, depending on the susceptibility of the strain. In the susceptible strain, the classical reduction pathway of nitroaromatic compounds is followed at least as far as the nitroso-radical anion, with further formation of the azo-dimer: 5,5'-azobis-(1,2-dimethylimidazole). In the resistant strain, DMZ is reduced to the amine derivative, namely, 5-amino-1,2-dimethylimidazole, preventing the formation of the toxic form of the drug. The specificity of the six-electron reduction of the nitro group, which is restricted to 4- and 5-nitroimidazole, suggests an enzymatic reaction. We thus conclude that nimA and related genes may encode a 5-nitroimidazole reductase. PMID:9210672

  7. [Bacteria isolated from surgical infections and its susceptibilities to antimicrobial agents--special references to bacteria isolated between april 2003 and march 2004].

    PubMed

    Shinagawa, Nagao; Fuchimoto, Sadayoshi; Sueda, Taijiro; Hiyama, Eizo; Takesue, Yoshio; Murakami, Yoshiaki; Ooge, Hiroki; Uemura, Kenichiro; Mizuno, Isamu; Tsumura, Hiroaki; Hirata, Koichi; Katsuramaki, Tadashi; Mizukuchi, Tohru; Ushijima, Yasuhide; Ushida, Tomohiro; Aikawa, Naoki; Yo, Kikuo; Takayama, Tadatoshi; Sato, Takeshi; Kato, Koumei; Yura, Jiro; Manabe, Tadao; Takeyama, Hiromitsu; Wakasugi, Takehiro; Taniguchi, Masaaki; Yokoyama, Takashi; Takeuchi, Hitoshi; Yasui, Yoshimasa; Mashita, Keiji; Ikeda, Seiyo; Yasunami, Yoichi; Ryu, Shinichiro; Ishikawa, Syu; Mizuno, Akira; Kubo, Shoji; Suehiro, Shigefumi; Fujimoto, Mikio; Higaki, Kazuyuki; Tanimura, Hiroshi; Taniguchi, Katsutoshi; Tsuji, Takeshi; Ohnishi, Hironobu; Yamaue, Hiroki; Kawai, Manabu; Tanaka, Noriaki; Iwagaki, Hiromi; Kimura, Hideyuki

    2007-04-01

    Tendency of isolated bacteria from infections in abdominal surgery during the period from April 2005 to March 2006 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, 384 strains including 18 strains of Candida spp. were isolated from 161 (70.3%) of 229 patients with surgical infections. One hundred and ninty-five strains were isolated from primary infections, and 171 strains were isolated from postoperative infections. From primary infections, aerobic Gram-negative bacteria and aerobic Gram-positive bacteria were predominant, while aerobic Gram-positive bacteria were predominant from postoperative infections. The isolation rate of aerobic Gram-positive bacteria, such as Enterococcus spp. and Staphylococcus aureus were higher from both types of infections. Among anaerobic Gram-positive bacteria, the isolation rate of Peptostreptococcus spp. was the highest from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Pseudomonas aeruginosa, Klebsiella spp. in this order, and from postoperative infections, E. coli was the most predominantly isolated, followed by Klebsiella pneumoniae and P. aeruginosa. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both primary and postoperative infections. In this series, we noticed no vancomycin-resistant Gram-positive cocci, nor multidrug-resistant P. aeruginosa. But cefazolin-resistant E. coli producing extended spectrum fl-lactamase was seen in 5.0 per cents. We should be carefully followed up the facts that the increasing isolation rates of B. fragilis group and Bilophila wadsworthia which were resistant to both penicillins and cephems. PMID:17612256

  8. Group dynamics and catecholamines during long-duration confinement in an isolated environment

    NASA Technical Reports Server (NTRS)

    Kraft, Norbert O.; Lyons, Terence J.; Binder, Heidi

    2003-01-01

    INTRODUCTION: The objectives of this study were to investigate possible relationships between catecholamine excretion and long-duration confinement in an isolated environment. METHODS: Stays of long duration were made by Group I (n = 4, all Russian, weeks 1-34), Group II (n = 4, mixed nationality, weeks 3-18), and Group III (n = 4, mixed nationality, weeks 22-38); other groups joined the residents for 1-wk intervals at weeks #13, #19, and #33. Data were collected from Groups I and III. RESULTS: In both Group I and Group III, the daily epinephrine excretion was significantly elevated during and after confinement compared with the pre-isolation baseline (p < 0.05), but remained mostly within normal limits during the experiment. During isolation, epinephrine excretion was significantly higher, compared with other weeks in isolation, during weeks #19 and #27 for Group I, and during week #30 for Group III. In both Group I and Group II, norepinephrine excretion increased significantly during and after isolation (p < 0.05) and was above the normal range. The daily norepinephrine excretion was significantly higher (p < 0.05) in Group I during weeks #12, #13, and #27, and during week #30 for Group III. DISCUSSION: Epinephrine excretion generally remained in the normal range. However, occasional elevations occurred due to psychological stress, which apparently correlate with changes in group dynamics. Norepinephrine excretion was above the normal range and was correlated with social events. These results suggest that to ensure optimum crew performance, entire crews along with their visiting crews should be selected collectively, rather than individually.

  9. Multiple Mobile Promoter Regions for the Rare Carbapenem Resistance Gene of Bacteroides fragilis

    PubMed Central

    Podglajen, I.; Breuil, J.; Rohaut, A.; Monsempes, C.; Collatz, E.

    2001-01-01

    Two novel insertion sequences (IS), IS1187 and IS1188, are described upstream from the carbapenem resistance gene cfiA in strains of Bacteroides fragilis. Mapping, with the RACE procedure, of transcription start sites of cfiA in these and two other previously reported IS showed that transcription of this rarely encountered gene is initiated close to a variety of B. fragilis consensus promoter sequences, as recently defined (D. P. Bayley, E. R. Rocha, and C. J. Smith, FEMS Microbiol. Lett. 193:149–154, 2000). In the cases of IS1186 and IS1188, these sequences overlap with putative Eς70 promoter sequences, while in IS942 and IS1187 such sequences can be observed either upstream or downstream of the B. fragilis promoters. PMID:11344163

  10. Clostridium botulinum Group II Isolate Phylogenomic Profiling Using Whole-Genome Sequence Data

    PubMed Central

    Weedmark, K. A.; Mabon, P.; Hayden, K. L.; Lambert, D.; Van Domselaar, G.; Austin, J. W.

    2015-01-01

    Clostridium botulinum group II isolates (n = 163) from different geographic regions, outbreaks, and neurotoxin types and subtypes were characterized in silico using whole-genome sequence data. Two clusters representing a variety of botulinum neurotoxin (BoNT) types and subtypes were identified by multilocus sequence typing (MLST) and core single nucleotide polymorphism (SNP) analysis. While one cluster included BoNT/B4/F6/E9 and nontoxigenic members, the other comprised a wide variety of different BoNT/E subtype isolates and a nontoxigenic strain. In silico MLST and core SNP methods were consistent in terms of clade-level isolate classification; however, core SNP analysis showed higher resolution capability. Furthermore, core SNP analysis correctly distinguished isolates by outbreak and location. This study illustrated the utility of next-generation sequence-based typing approaches for isolate characterization and source attribution and identified discrete SNP loci and MLST alleles for isolate comparison. PMID:26116673

  11. Clostridium botulinum Group II Isolate Phylogenomic Profiling Using Whole-Genome Sequence Data.

    PubMed

    Weedmark, K A; Mabon, P; Hayden, K L; Lambert, D; Van Domselaar, G; Austin, J W; Corbett, C R

    2015-09-01

    Clostridium botulinum group II isolates (n = 163) from different geographic regions, outbreaks, and neurotoxin types and subtypes were characterized in silico using whole-genome sequence data. Two clusters representing a variety of botulinum neurotoxin (BoNT) types and subtypes were identified by multilocus sequence typing (MLST) and core single nucleotide polymorphism (SNP) analysis. While one cluster included BoNT/B4/F6/E9 and nontoxigenic members, the other comprised a wide variety of different BoNT/E subtype isolates and a nontoxigenic strain. In silico MLST and core SNP methods were consistent in terms of clade-level isolate classification; however, core SNP analysis showed higher resolution capability. Furthermore, core SNP analysis correctly distinguished isolates by outbreak and location. This study illustrated the utility of next-generation sequence-based typing approaches for isolate characterization and source attribution and identified discrete SNP loci and MLST alleles for isolate comparison. PMID:26116673

  12. Association of social isolation and health across different racial and ethnic groups of older Americans

    PubMed Central

    MIYAWAKI, CHRISTINA E.

    2015-01-01

    Social isolation is a social and public health problem that affects people of all ages, especially elders. Previous studies have found that social isolation across numerous industrialised countries is associated with negative health outcomes. However, it is unknown whether and how this association differs by race/ethnicity and age. To begin to address this gap, this study examines the association of social isolation and physical and mental health among Black, White and Hispanic elders in the United States of America. Building on Cornwell and Waite's perceived isolation and social disconnectedness dimension model of social isolation, the author used multi-stage survey data from a nationally representative sample of 3,005 community-residing adults aged 57–85 from the National Social Life, Health, and Aging Project. Tests for association were conducted on health by age, gender, marital status, education and race/ethnicity separately. Multivariate logistic regressions were used to test the association of social isolation and health exclusively and separately among these three groups. Results showed that social isolation is strongly associated with physical and mental health. Both perceived isolation and social disconnectedness had a significant negative association with physical and mental health among White elders. For Blacks, social disconnectedness is negatively associated with their physical health while perceived isolation had a negative association with mental health. Among Hispanic elders, there seemed to be no association between social isolation and physical health, but a significant negative association was found with their mental health. Despite various associated patterns, however, social isolation overall was associated with health outcomes that were similar across three elder groups. By identifying factors influencing social isolation and health among minority older Americans, this study has relevance to the development of culturally sensitive health

  13. Streptococcus equi subsp. zooepidemicus isolates from equine infectious endometritis belong to a distinct genetic group.

    PubMed

    Rasmussen, Camilla Dooleweerdt; Haugaard, Maria Mathilde; Petersen, Morten Roenn; Nielsen, Jesper Møller; Pedersen, Hanne Gervi; Bojesen, Anders Miki

    2013-01-01

    Streptococcus equi subsp. zooepidemicus is the pathogen most commonly isolated from the uterus of mares. S. zooepidemicus is an opportunistic pathogen and part of the resident flora in the caudal reproductive tract. The aim of this study was to investigate whether a genotypically distinct subpopulation of S. zooepidemicus is associated with endometritis in the mare, by genotyping and comparing uterine S. zooepidemicus strains with isolates from the vagina and clitoral fossa. Mares with (n=18) or without (n=11) clinical symptoms of endometritis were included. Uterine samples were obtained using a guarded endometrial biopsy punch, whereas a swab was used to recover samples from the cranial vagina and the clitoral fossa. If S. zooepidemicus was present, up to three colonies were selected from each anatomical location (max. 9 isolates per mare). Bacterial isolates were characterized by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). S. zooepidemicus was isolated from the endometrium of 12 mares. A total of 88 isolates were analyzed by PFGE: 31 from the endometrium, 26 from the cranial vagina and 31 isolates from the clitoral fossa. For MLST 21 isolates were chosen. Results demonstrated a higher genetic similarity of the isolates obtained from infectious endometritis compared to isolates obtained from the caudal reproductive tract. In conclusion, we demonstrate for the first time that a genetically distinct group of S. zooepidemicus is associated with infectious endometritis in the mare. PMID:23597033

  14. Streptococcus equi subsp. zooepidemicus isolates from equine infectious endometritis belong to a distinct genetic group

    PubMed Central

    2013-01-01

    Streptococcus equi subsp. zooepidemicus is the pathogen most commonly isolated from the uterus of mares. S. zooepidemicus is an opportunistic pathogen and part of the resident flora in the caudal reproductive tract. The aim of this study was to investigate whether a genotypically distinct subpopulation of S. zooepidemicus is associated with endometritis in the mare, by genotyping and comparing uterine S. zooepidemicus strains with isolates from the vagina and clitoral fossa. Mares with (n = 18) or without (n = 11) clinical symptoms of endometritis were included. Uterine samples were obtained using a guarded endometrial biopsy punch, whereas a swab was used to recover samples from the cranial vagina and the clitoral fossa. If S. zooepidemicus was present, up to three colonies were selected from each anatomical location (max. 9 isolates per mare). Bacterial isolates were characterized by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). S. zooepidemicus was isolated from the endometrium of 12 mares. A total of 88 isolates were analyzed by PFGE: 31 from the endometrium, 26 from the cranial vagina and 31 isolates from the clitoral fossa. For MLST 21 isolates were chosen. Results demonstrated a higher genetic similarity of the isolates obtained from infectious endometritis compared to isolates obtained from the caudal reproductive tract. In conclusion, we demonstrate for the first time that a genetically distinct group of S. zooepidemicus is associated with infectious endometritis in the mare. PMID:23597033

  15. Evaluation of Multiplex Tandem Real-Time PCR for Detection of Cryptosporidium spp., Dientamoeba fragilis, Entamoeba histolytica, and Giardia intestinalis in Clinical Stool Samples ▿

    PubMed Central

    Stark, D.; Al-Qassab, S. E.; Barratt, J. L. N.; Stanley, K.; Roberts, T.; Marriott, D.; Harkness, J.; Ellis, J. T.

    2011-01-01

    The aim of this study was to describe the first development and evaluation of a multiplex tandem PCR (MT-PCR) assay for the detection and identification of 4 common pathogenic protozoan parasites, Cryptosporidium spp., Dientamoeba fragilis, Entamoeba histolytica, and Giardia intestinalis, from human clinical samples. A total of 472 fecal samples submitted to the Department of Microbiology at St. Vincent's Hospital were included in the study. The MT-PCR assay was compared to four real-time PCR (RT-PCR) assays and microscopy by a traditional modified iron hematoxylin stain. The MT-PCR detected 28 G. intestinalis, 26 D. fragilis, 11 E. histolytica, and 9 Cryptosporidium sp. isolates. Detection and identification of the fecal protozoa by MT-PCR demonstrated 100% correlation with the RT-PCR results, and compared to RT-PCR, MT-PCR exhibited 100% sensitivity and specificity, while traditional microscopy of stained fixed fecal smears exhibited sensitivities and specificities of 56% and 100% for Cryptosporidium spp., 38% and 99% for D. fragilis, 47% and 97% for E. histolytica, and 50% and 100% for G. intestinalis. No cross-reactivity was detected in 100 stool samples containing various other bacterial, viral, and protozoan species. The MT-PCR assay was able to provide rapid, sensitive, and specific simultaneous detection and identification of the four most important diarrhea-causing protozoan parasites that infect humans. This study also highlights the lack of sensitivity demonstrated by microscopy, and thus, molecular methods such as MT-PCR must be considered the diagnostic methods of choice for enteric protozoan parasites. PMID:21048004

  16. Group C streptococci in human infection: a study of 308 isolates with clinical correlations.

    PubMed

    Barnham, M; Kerby, J; Chandler, R S; Millar, M R

    1989-06-01

    A collection of 308 clinical isolates of beta-haemolytic Lancefield group C streptococci was assembled from laboratories in England, Nigeria and New Zealand. Of these, 276 isolates were Streptococcus equisimilis, 23 S. milleri and nine S. zooepidemicus. Isolates of S. equisimilis in the African collection, though few, gave higher rates of lactose and raffinose fermentation, aesculin hydrolysis and positive alpha-galactosidase reactions than those from elsewhere. Erythromycin resistance was found in 1.9% of the English isolates of S. equisimilis. Strains from superficial infections accounted for 88% of the collection and were most commonly isolated from the upper respiratory tract, skin or wounds. Amongst the 36 patients yielding isolates from deep sites S. equisimilis was found in septicaemia, cellulitis, abscess, peritonitis, septic arthritis, pneumonia, mycotic aneurysm and acute epiglottitis, S. milleri was found in abdominal abscesses, peritonitis, pleural empyema and osteomyelitis and S. zooepidemicus was found in septicaemia, pneumonia, meningitis and septic arthritis. Within the collection an unselected general catchment of 214 isolates of group C streptococci from the laboratories in Yorkshire showed the following species: from 199 superficial infections 94% S. equisimilis, 5% S. milleri and 1% S. zooepidemicus and 15 patients with deeper, more aggressive infections 67, 27 and 6.7% of these species respectively. PMID:2737252

  17. Use of guinea pig embryo cell cultures for isolation and propagation of group A coxsackieviruses.

    PubMed Central

    Landry, M L; Madore, H P; Fong, C K; Hsiung, G D

    1981-01-01

    The isolation of group A coxsackieviruses from clinical specimens generally requires the use of suckling mice. By using guinea pig embryo cells, the following coxsackieviruses were isolated from throat swabs and stool samples obtained from patients with a variety of illnesses: two of type A2, one each of types A6 and A8, and four of type 10. Distinct cytopathic effects were produced in 3 to 5 days in the guinea pig embryo cells inoculated with the clinical specimens. In addition, a number of prototype group A coxsackieviruses, including types 2--6, 8, 10, and 12, were readily propagated in guinea pig embryo cell cultures. Thus, guinea pig embryo cells appeared to be a sensitive alternative cell culture system for the isolation and propagation of certain types of group A coxsackieviruses. Images PMID:6263943

  18. Effect of Habitat Size, Quality, and Isolation on Functional Groups of Beetles in Hollow Oaks.

    PubMed

    Pilskog, Hanne Eik; Birkemoe, Tone; Framstad, Erik; Sverdrup-Thygeson, Anne

    2016-01-01

    One of the largest threats to biodiversity is land use change and habitat loss. Hollow oaks (Quercus spp. L.) are well-defined patches that are hotspots for biodiversity and red-listed species, but they are often rare and fragmented in the landscape. We investigated the effect of patch size, habitat quality, and isolation on functional groups and red-listed saproxylic beetles in hollow oaks (n = 40) in Norway. The groups were defined by host tree association, trophic grouping, and red-listed status. Habitat quality, represented by tree form was most important in explaining species richness for most groups. Patch size, represented by circumference and amount of dead branches, was most important in explaining abundance. Isolation, that is single oaks compared with oaks in groups, had a negative effect on the abundance of beetles feeding both on wood and fungi (xylomycethopagous), as well as on species associated with broadleaved trees (oak semi-specialists), but did not affect species richness. This indicates that at this scale and in this landscape, isolated oaks are as species rich and valuable for conservation as other oaks, although some functional groups may be more vulnerable to isolation than others. The red-listed species only responded to patch size, indicating that oaks with large circumference and many dead branches are especially important for red-listed species and for conservation. PMID:26945089

  19. Effect of Habitat Size, Quality, and Isolation on Functional Groups of Beetles in Hollow Oaks

    PubMed Central

    Pilskog, Hanne Eik; Birkemoe, Tone; Framstad, Erik; Sverdrup-Thygeson, Anne

    2016-01-01

    One of the largest threats to biodiversity is land use change and habitat loss. Hollow oaks (Quercus spp. L.) are well-defined patches that are hotspots for biodiversity and red-listed species, but they are often rare and fragmented in the landscape. We investigated the effect of patch size, habitat quality, and isolation on functional groups and red-listed saproxylic beetles in hollow oaks (n = 40) in Norway. The groups were defined by host tree association, trophic grouping, and red-listed status. Habitat quality, represented by tree form was most important in explaining species richness for most groups. Patch size, represented by circumference and amount of dead branches, was most important in explaining abundance. Isolation, that is single oaks compared with oaks in groups, had a negative effect on the abundance of beetles feeding both on wood and fungi (xylomycethopagous), as well as on species associated with broadleaved trees (oak semi-specialists), but did not affect species richness. This indicates that at this scale and in this landscape, isolated oaks are as species rich and valuable for conservation as other oaks, although some functional groups may be more vulnerable to isolation than others. The red-listed species only responded to patch size, indicating that oaks with large circumference and many dead branches are especially important for red-listed species and for conservation. PMID:26945089

  20. Draft Genome Sequence of the Probiotic Yeast Kluyveromyces marxianus fragilis B0399

    PubMed Central

    Quarella, Sara; Lovrovich, Paola; Scalabrin, Simone; Campedelli, Ilenia; Backovic, Ana; Gatto, Veronica; Cattonaro, Federica; Turello, Alessandro; Felis, Giovanna E.

    2016-01-01

    Here, we report the draft genome sequence of Kluyveromyces marxianus fragilis B0399, the first yeast approved as a probiotic for human consumption not belonging to the genus Saccharomyces. The genome is composed of 8 chromosomes, with a total size of 11.44 Mb, including mitochondrial DNA. PMID:27587830

  1. Multidrug-Resistant Bacteroides fragilis Bacteremia in a US Resident: An Emerging Challenge

    PubMed Central

    Parajuli, Sunita; Siegfried, Justin; Dubrovskaya, Yanina; Rahimian, Joseph

    2016-01-01

    We describe a case of Bacteroides fragilis bacteremia associated with paraspinal and psoas abscesses in the United States. Resistance to b-lactam/b-lactamase inhibitors, carbapenems, and metronidazole was encountered despite having a recent travel history to India as the only possible risk factor for multidrug resistance. Microbiological cure was achieved with linezolid, moxifloxacin, and cefoxitin. PMID:27418986

  2. Draft Genome Sequence of the Probiotic Yeast Kluyveromyces marxianus fragilis B0399.

    PubMed

    Quarella, Sara; Lovrovich, Paola; Scalabrin, Simone; Campedelli, Ilenia; Backovic, Ana; Gatto, Veronica; Cattonaro, Federica; Turello, Alessandro; Torriani, Sandra; Felis, Giovanna E

    2016-01-01

    Here, we report the draft genome sequence of Kluyveromyces marxianus fragilis B0399, the first yeast approved as a probiotic for human consumption not belonging to the genus Saccharomyces The genome is composed of 8 chromosomes, with a total size of 11.44 Mb, including mitochondrial DNA. PMID:27587830

  3. Plasmids in group JK coryneform bacteria isolated in a single hospital.

    PubMed Central

    Kerry-Williams, S. M.; Noble, W. C.

    1986-01-01

    Investigation of 39 JK-type coryneform isolates from patients at a single hospital revealed that 23 possessed plasmids, which formed six groups on restriction endonuclease analysis. Four of the groups were associated with production of similar bacteriocin-like substances, and shared a minimum of 6.4 kilobase pairs of DNA. These plasmids, found in isolates from different patients, provide strong direct evidence that person-to-person transmission of JK bacteria had occurred within the hospital. Images Fig. 1 PMID:3023480

  4. Expression of group B protective surface protein (BPS) by invasive and colonizing isolates of group B streptococci.

    PubMed

    Flores, Aurea E; Chhatwal, G S; Hillier, Sharon L; Baker, Carol J; Ferrieri, Patricia

    2014-12-01

    Group B protective surface protein (BPS) is expressed on the cell surface of some group B streptococcal (GBS) (Streptococcus agalactiae) strains and adds to the identification by capsular polysaccharide (CPS), and c or R proteins. We investigated the prevalence of BPS among GBS clinical isolates (303 invasive, 4122 colonizing) collected over 11 years in four American cities. Hot HCl cell extracts were tested by immunoprecipitation in agarose with rabbit antisera to BPS; the alpha (α) and beta (β) components of c protein; R1, R3, and R4 species of R protein; and CPS serotypes Ia-VIII. BPS was found in 155 isolates (seven invasive, 148 colonizing). Of these, 87 were Ia, 37 II, 20 V; none were III. BPS was expressed usually with another protein: a species of R by 87 or a component of c by 39. The predominant CPS/protein profiles with BPS were Ia/R1,BPS and II/c(α + β),BPS. Thus, along with CPS serotype and other surface proteins, BPS can be a valuable marker for precise strain characterization of unique GBS clinical isolates with complex surface protein profiles. PMID:25108378

  5. Comparison of the transport of Bacteroides fragilis and Escherichia coli within saturated sand packs.

    PubMed

    Johanson, Jennifer J; Feriancikova, Lucia; Banerjee, Areen; Saffarini, Daâd A; Wang, Lixia; Li, Jin; Grundl, Timothy J; Xu, Shangping

    2014-11-01

    Pathogens in groundwater accounted for ∼50% of waterborne disease outbreaks in the United States between 1971 and 2006. The fast and reliable detection of groundwater microbial contamination and the identification of the contamination sources are of critical importance to the protection of public health. Recent studies suggested that fecal anaerobe Bacteriodes spp. could be employed as an effective tool for surface water microbial source tracking (MST). The usefulness of Bacteroides spp. for groundwater MST depends strongly on its mobility within the subsurface system. This research provides laboratory results comparing transport and attachment of E. coli K12 and B. fragilis within packed quartz sands. The results indicate that at low ionic strengths both E. coli K12 and B. fragilis are readily transported through saturated sand packs. At higher ionic strengths such as may be found near concentrated sources of fecal contamination, B. fragilis displayed significantly higher mobility than E. coli K12. Analysis of the extended Derjaguin-Landau-Verweu-Overbeek (XDLVO) energy interactions for both types of bacteria showed a significant repulsive energy barrier exists between the sand surface and the bacteria, precluding attachment directly to the sand surface. However a secondary minimum energy level exists under higher ionic strength conditions. The depth of this energy low is greater for E. coli K12, which results in greater attachment of E. coli K12 than of B. fragilis. The high mobility of B. fragilis suggests that it represents a promising tool for the detection of groundwater fecal contamination as well as the identification of the microbial sources. PMID:25448721

  6. Portability of tag SNPs across isolated population groups: an example from India.

    PubMed

    Sarkar Roy, N; Farheen, S; Roy, N; Sengupta, S; Majumder, P P

    2008-01-01

    Isolated population groups are useful in conducting association studies of complex diseases to avoid various pitfalls, including those arising from population stratification. Since DNA resequencing is expensive, it is recommended that genotyping be carried out at tagSNP (tSNP) loci. For this, tSNPs identified in one isolated population need to be used in another. Unless tSNPs are highly portable across populations this strategy may result in loss of information in association studies. We examined the issue of tSNP portability by sampling individuals from 10 isolated ethnic groups from India. We generated DNA resequencing data pertaining to 3 genomic regions and identified tSNPs in each population. We defined an index of tSNP portability and showed that portability is low across isolated Indian ethnic groups. The extent of portability did not significantly correlate with genetic similarity among the populations studied here. We also analyzed our data with sequence data from individuals of African and European descent. Our results indicated that it may be necessary to carry out resequencing in a small number of individuals to discover SNPs and identify tSNPs in the specific isolated population in which a disease association study is to be conducted. PMID:17627800

  7. [Genetic diversity of group A rotavirus isolates found in Western Siberia in 2007-2011].

    PubMed

    Zhirakovskaia, E V; Aksanova, R Kh; Gorbunova, M G; Tikunov, A Iu; Kuril'shchikov, A M; Sokolov, S N; Netesov, S V; Tikunova, N V

    2012-01-01

    Genetic analysis of group A rotavirus recovered from fecal samples of children admitted to hospitals in Novosibirsk and Omsk during four epidemic seasons 2007, 2007/2008, 2009/2010, 2010/2011 was performed. A total of 1416 rotavirus isolates were genotyped using multiplex PCR. The isolates of the most common rotavirus genotypes G1P[8], G4P[8], G2P[4], G3P[8] co-circulated in Western Siberia during 2007-2011. In isolated cases G9P[8], G2P[8], G3P[9], and G4P[6] genotypes were detected. Change of dominant genotype from G1P[8] to G4P[8] occurred in 2008 in Omsk and in Novosibirsk in 2009 as well. Incidence and distribution of rotavirus genotypes differed and changed every epidemic season in both cities. The phylogenetic analysis based on VP4 (VP8*), VP7, and VP6 gene sequences showed that the majority of isolates from Novosibirsk and Omsk were clustered together and demonstrated high level homology with rotavirus isolates found in other regions of Eurasia. In addition, a rare P[8]b (OP354-like) subtype of the VP4 gene was identified in fourteen isolates (G9, G1, and G4) in Novosibirsk and in a single isolate Omsk08-381/G9P[8]b in Omsk. The results obtained in this study demonstrate the necessity of long-term monitoring of rotavirus isolates in Western Siberia. This is important for selection of rotavirus vaccine for immunization of infants, improvement of diagnostic kits and understanding of the epidemiology and the evolution of group A rotaviruses. PMID:23248851

  8. Streptococcus anginosus (milleri) Group Strains Isolated in Poland (1996-2012) and their Antibiotic Resistance Patterns.

    PubMed

    Obszańska, Katarzyna; Kern-Zdanowicz, Izabella; Kozińska, Aleksandra; Machura, Katarzyna; Stefaniuk, Elzbieta; Hryniewicz, Waleria; Sitkiewicz, Izabela

    2016-01-01

    Streptococcus anginosus, Streptococcus intermedius and Streptococcus constellatus form a group of related streptococcal species, namely the Streptococcus Anginosus Group (SAG). The group, previously called "milleri" had been rarely described until 1980/1990 as source of infections. Nowadays SAG bacteria are often described as pathogens causing predominantly purulent infections. The number of infections is highly underestimated, as SAG strains are often classified in the microbiology laboratory as less virulent "viridans streptococci" Epidemiological situation regarding SAG infections in Poland has been unrecognized, therefore we performed a retrospective analysis of strains isolated between 1996 and 2012. Strains suspected of belonging to SAG were re-identified using an automated biochemical approach (Vitek2) and MALDI-TOF MS. We performed first analysis of antibiotic resistance among SAG strains isolated in Poland using automated methods (Vitek2), disk diffusion tests and E-Tests. We also performed PCR detection of resistance determinants in antibiotic resistant strains. Clonal structure of analyzed strains was evaluated with PFGE and MLVF methods. All three species are difficult to distinguish using automated diagnostic methods and the same is true for automated MIC evaluation. Our analysis revealed SAG strains are rarely isolated in Poland, predominantly from purulent infections. All isolates are very diverse on the genomic level as estimated by PFGE and MLVF analyses. All analyzed strains are sensitive to penicillin, a substantial group of strains is resistant to macrolides and the majority of strains are resistant to tetracycline. PMID:27281992

  9. Reproduction of PMWS of high mortality with a porcine circovirus type 2-group 1 isolate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction In late 2005, sporadic cases of an acute onset of high mortality disease were observed in growing pigs among USA swine herds. PCV2-group 1 (Gp1) virus was consistently detected among the affected animals. Phylogenetic analysis showed that the PCV2 isolates from the United States until l...

  10. Clinical features of group B Streptococcus prosthetic joint infections and molecular characterization of isolates.

    PubMed

    Corvec, S; Illiaquer, M; Touchais, S; Boutoille, D; van der Mee-Marquet, N; Quentin, R; Reynaud, A; Lepelletier, D; Bémer, P

    2011-01-01

    Twelve group B Streptococcus (GBS) prosthetic joint infection (PJI) cases are reported. The mean patient age was 55 years. Eleven infections were caused by GBS alone. The associated isolates belonged to phylogenetic lineages different from those that cause neonatal meningitis. The clinical outcome was favorable for the eight patients for whom follow-up data were available. PMID:21068273

  11. Clinical Features of Group B Streptococcus Prosthetic Joint Infections and Molecular Characterization of Isolates

    PubMed Central

    Corvec, S.; Illiaquer, M.; Touchais, S.; Boutoille, D.; van der Mee-Marquet, N.; Quentin, R.; Reynaud, A.; Lepelletier, D.; Bémer, P.

    2011-01-01

    Twelve group B Streptococcus (GBS) prosthetic joint infection (PJI) cases are reported. The mean patient age was 55 years. Eleven infections were caused by GBS alone. The associated isolates belonged to phylogenetic lineages different from those that cause neonatal meningitis. The clinical outcome was favorable for the eight patients for whom follow-up data were available. PMID:21068273

  12. Genomic Characterization of Group C Orthobunyavirus Reference Strains and Recent South American Clinical Isolates

    PubMed Central

    Yang, Yu; Solórzano, Víctor Fiestas; Kuschner, Robert A.; Halsey, Eric S.; Jarman, Richard G.; Kochel, Tadeusz J.

    2014-01-01

    Group C orthobunyaviruses (family Bunyaviridae, genus Orthobunyavirus), discovered in the 1950s, are vector-borne human pathogens in the Americas. Currently there is a gap in genomic information for group C viruses. In this study, we obtained complete coding region sequences of reference strains of Caraparu (CARV), Oriboca (ORIV), Marituba (MTBV) and Madrid (MADV) viruses, and five clinical isolates from Peru and Bolivia, using an unbiased de novo approach consisting of random reverse transcription, random anchored PCR amplification, and high throughput pyrosequencing. The small, medium, and large segments encode for a 235 amino acid nucleocapsid protein, an approximately 1430 amino acid surface glycoprotein polyprotein precursor, and a 2248 amino acid RNA-dependent RNA polymerase, respectively. Additionally, the S segment encodes for an 83 amino acid non-structural protein, although this protein is truncated or silenced in some isolates. Phylogenetically, three clinical isolates clustered with CARV, one clustered with MTBV, and one isolate appeared to be a reassortant or a genetic drift resulted from the high variability of the medium segment which was also seen in a few other orthobunyaviruses. These data represent the first complete coding region sequences for this serocomplex of pathogenic orthobunyaviruses. The genome-wide phylogeny of reference strains is consistent with the antigenic properties of the viruses reported in the original serological studies conducted in the 1960s. Comparative analysis of conserved protein regions across group C virus strains and the other orthobunyavirus groups revealed that these group C viruses contain characteristic domains of potential structural and functional significance. Our results provide the basis for the developments of diagnostics, further genetic analyses, and future epidemiologic studies of group C viruses. PMID:24633174

  13. Population Biology of Intestinal Enterococcus Isolates from Hospitalized and Nonhospitalized Individuals in Different Age Groups

    PubMed Central

    Tedim, Ana P.; Ruiz-Garbajosa, Patricia; Corander, Jukka; Rodríguez, Concepción M.; Cantón, Rafael; Willems, Rob J.; Baquero, Fernando

    2014-01-01

    The diversity of enterococcal populations from fecal samples from hospitalized (n = 133) and nonhospitalized individuals (n = 173) of different age groups (group I, ages 0 to 19 years; group II, ages 20 to 59 years; group III, ages ≥60 years) was analyzed. Enterococci were recovered at similar rates from hospitalized and nonhospitalized persons (77.44% to 79.77%) of all age groups (75.0% to 82.61%). Enterococcus faecalis and Enterococcus faecium were predominant, although seven other Enterococcus species were identified. E. faecalis and E. faecium (including ampicillin-resistant E. faecium) colonization rates in nonhospitalized persons were age independent. For inpatients, E. faecalis colonization rates were age independent, but E. faecium colonization rates (particularly the rates of ampicillin-resistant E. faecium colonization) significantly increased with age. The population structure of E. faecium and E. faecalis was determined by superimposing goeBURST and Bayesian analysis of the population structure (BAPS). Most E. faecium sequence types (STs; 150 isolates belonging to 75 STs) were linked to BAPS groups 1 (22.0%), 2 (31.3%), and 3 (36.7%). A positive association between hospital isolates and BAPS subgroups 2.1a and 3.3a (which included major ampicillin-resistant E. faecium human lineages) and between community-based ampicillin-resistant E. faecium isolates and BAPS subgroups 1.2 and 3.3b was found. Most E. faecalis isolates (130 isolates belonging to 58 STs) were grouped into 3 BAPS groups, BAPS groups 1 (36.9%), 2 (40.0%), and 3 (23.1%), with each one comprising widespread lineages. No positive associations with age or hospitalization were established. The diversity and dynamics of enterococcal populations in the fecal microbiota of healthy humans are largely unexplored, with the available knowledge being fragmented and contradictory. The study offers a novel and comprehensive analysis of enterococcal population landscapes and suggests that E. faecium

  14. Molecular epidemiology of Legionella pneumophila serogroup 1 isolates identify a prevalent sequence type, ST505, and a distinct clonal group of clinical isolates in Toyama Prefecture, Japan.

    PubMed

    Kanatani, Jun-Ichi; Isobe, Junko; Kimata, Keiko; Shima, Tomoko; Shimizu, Miwako; Kura, Fumiaki; Sata, Tetsutaro; Watahiki, Masanori

    2013-08-01

    We performed comparative analyses of Legionella pneumophila serogroup (SG) 1 isolates obtained during 2005-2012 in Toyama Prefecture, Japan, by sequence-based typing (SBT) and pulsed-field gel electrophoresis (PFGE). Seventy-three isolates of L. pneumophila SG 1, including 17 isolates from patients, 51 from public baths, 4 from cooling towers, and 1 from a shower, were analyzed. The isolates were classified into 43 sequence types (STs) by SBT and 52 types by PFGE. Fourteen STs were unique to Toyama Prefecture, as determined from the SBT database of European Working Group for Legionella Infections (EWGLI), as of October 31, 2012. ST505 strain was identified in 4 isolates from patients and 5 isolates from public baths, and these isolates belonged to 2 PFGE types. These, however, were similar because of the difference with only two restriction fragments, indicating that ST505 strain was prevalent among L. pneumophila SG 1 isolates in this area. ST505 strains isolated from patients and public baths were distributed along the river in a western part of Toyama Prefecture. SBT and PFGE profiles of 3 clinical isolates were identical with those of 3 environmental isolates from the suspected origins of the infection in each case, respectively. This finding suggested that SBT and PFGE were useful for epidemiological study. Furthermore, by SBT analysis, we identified a clonal group formed only by 7 clinical isolates that are not associated with bathwater, suggesting that they were derived from unrecognized sources. PMID:23269379

  15. Group dynamics during the EXEMSI isolation study. Experimental Campaign for the European Manned Space Infrastructure.

    PubMed

    Cazes, C; Rosnet, E; Bachelard, C; Le Scanff, C; Rivolier, J

    1996-01-01

    The objectives of this study were to investigate the social behavior, interrelations, cohesion, efficiency and team formation of the crew during 60 days of isolation and confinement, to make a critical comparison of a variety of test methods used for this purpose and to formulate recommendations for their applications in selection, training and support for future studies of this kind. The study consisted of three phases: (1) the pre-isolation period, in which initial individual and group assessment were made to understand the motivation, characteristics, and styles of the crew members, the state of the crew, and to make a prognosis for the behavior of the group and its members, (2) the isolation period, with tests and observations to follow and analyze behavior and group dynamics of the crew, and to detect manifestations of stress, and (3) the post-isolation period with final assessment and debriefing. During these three periods individual and group tests were carried out. Direct methods, questionnaires and tests, as well as indirect methods, observations of behavior, were used. These had cognitive, affective-emotional and social components; they were quantitative, qualitative or a combination. Before isolation the crew members expressed strong confidence in the team and in their own personal capability. The leadership of the Commander seemed uncontested. Crew functioning during this period was conflict-free, but was structured in a rather rigid and defensive way (isolation of affects, denial of anxiety). Apparently, the members strongly needed to present a good image image of themselves. The relatively short period of the experiment, and the absence of real risk suggested that the crew would be able to maintain their cohesion, but in a real spaceflight situation this behavior could be inadequate and even dangerous. The pre-isolation prognosis for crew behavior during isolation was validated to a large extent. During isolation there were no clear manifestations of

  16. Superantigen genes in group A streptococcal isolates and their relationship with emm types.

    PubMed

    Commons, Robert; Rogers, Susan; Gooding, Travis; Danchin, Margie; Carapetis, Jonathan; Robins-Browne, Roy; Curtis, Nigel

    2008-10-01

    Superantigens are important virulence factors in the pathogenesis of invasive disease caused by group A streptococcus (GAS). There has been a recent re-emergence of this disease worldwide. A number of novel superantigens have been described recently. This study investigated 107 isolates of GAS for possession of each of the 11 currently known superantigen genes to determine the prevalence, co-occurrence and genetic restriction amongst different emm types of GAS. The results were compared with those in previously published studies. Superantigen genes were not randomly distributed amongst GAS isolates. Certain combinations of superantigen genes were more common and the majority of emm types showed restricted superantigen profiles. This is the first prevalence study of GAS isolates to include the complete range of known superantigen genes and their restriction amongst emm types. This study contributes to the understanding of the relationship between superantigen genes and emm types, and highlights the importance of comprehensive studies in different populations. PMID:18809552

  17. Frequency perception of individual and group successes as a function of competition, coaction, and isolation.

    PubMed

    Janssens, L; Nuttin, J R

    1976-11-01

    The frequency perception of successful and unsuccessful outcomes obtained in serial tasks was investigated in two experiments. Subjects were assigned to serial tasks in which the outcome stimuli ("right" and "wrong") immediately followed subjects' responses to each task item. Subjects' perceptual judgment about the number of "rights and wrongs" obtained was requested at the end of the serial task (incidental event perception). In Experiment 1, subjects performing in groups of four were compared with individual performers both in competing and noncompeting (coacting) conditions. In Experiment 2, the influence of verbal communication and competition versus isolation was examined. Significant and predicted differences in frequeency perception were found (a) in group performers as compared with individual performers, (b) in groups with verbal communication as compared with groups without verbal communication, and (c) in competing groups as compared with noncompeting, especially isolated, groups. The frequency perception of success is discussed in the context of impression formation processes, and its impact on person perception and learning is mentioned. A tentative explanation in terms of affective and cognitive processes related to social interaction is submitted. PMID:993983

  18. Accumulation and effects of sulfadimethoxine in Salix fragilis L. plants: a preliminary study to phytoremediation purposes.

    PubMed

    Michelini, Lucia; Meggio, Franco; La Rocca, Nicoletta; Ferro, Stefania; Ghisi, Rossella

    2012-04-01

    The application of manure to fertilize arable lands is one of the major means through which veterinary sulfonamides (SAs) enter the environment. Little is known about the capacity of woody plants to phytoremediate this class of antibiotics. To this purpose we performed preliminary studies to evaluate Salix fragilis L. response to sulfadimethoxine (SDM) by investigating both its ability to absorb and tolerate doses of SDM found in fresh faeces of treated calves. Forty cuttings were exposed to either 0, 0.5, 1, or 2 mM of SDM for one month. Decreases in photosynthetic electron transport rate and net CO2 assimilation after 25 days for the higher SDM concentrations were noticed. Moreover, alterations in root morphology of treated plants were observed and further investigated through electron microscopy. However, collected data revealed high root accumulation potential. These preliminary results are promising as they demonstrate that Salix fragilis L. can both absorb and tolerate high concentrations of SAs. PMID:22567719

  19. Inhibition of ribonucleic acid polymerase by a bacteriocin from Bacteroides fragilis.

    PubMed Central

    Mossie, K G; Robb, F T; Jones, D T; Woods, D R

    1981-01-01

    The Bacteroides fragilis bacteriocin which inhibits ribonucleic acid (RNA) polymerase activity had a narrow activity spectrum in vivo and only inhibited the growth of certain B. fragilis strains. In vitro the bacteriocin was not specific and inhibited RNA polymerases from widely diverse bacterial genera. RNA polymerases from rifampin-resistant strains of Bacteroides thetaiotaomicron and Clostridium acetobutylicum were resistant to the bacteriocin in vitro. Purified bacteriocin bound to partially purified RNA polymerase, and both proteins were cosedimented in a glycerol gradient. In the RNA polymerase reaction, the bacteriocin acted as a competitive inhibitor for adenosine, cytidine, and uridine 5'-triphosphates and as a noncompetitive inhibitor for guanosine 5'-triphosphate. The bacteriocin did not inhibit RNA polymerase from chicken embryos. PMID:6177280

  20. A review of the Nearctic linyphiid spider Arcuphantes fragilis (Araneae, Linyphiidae) and closely related species.

    PubMed

    Ma, Shuangchun; Marusik, Yuri M; Tu, Lihong

    2016-01-01

    The Western Nearctic species Arcuphantes fragilis Chamberlin & Ivie, 1943 and several closely related species are reviewed. Seven species are recognized, including two new species: A. cavaticus Chamberlin & Ivie, 1943, A. decoratus Chamberlin & Ivie, 1943, A. fragilis Chamberlin & Ivie, 1943, A. dentatus n. sp., A. curvomarginatus n. sp., A. potteri Chamberlin & Ivie, 1943, and A. sylvaticus Chamberlin & Ivie, 1943. The female of A. decoratus is described for the first time. These seven species share a same genital type, distinguishing them from other congeners, with small differences among them. Illustrations for A. dentatus n. sp., SEM images and digital photographs for all seven species are presented. Descriptions of new species, redescriptions of known species and a key for the seven species are provided. PMID:27470863

  1. Biochemical and genetic analyses of a catalase from the anaerobic bacterium Bacteroides fragilis.

    PubMed Central

    Rocha, E R; Smith, C J

    1995-01-01

    A single catalase enzyme was produced by the anaerobic bacterium Bacteroides fragilis when cultures at late log phase were shifted to aerobic conditions. In anaerobic conditions, catalase activity was detected in stationary-phase cultures, indicating that not only oxygen exposure but also starvation may affect the production of this antioxidant enzyme. The purified enzyme showed a peroxidatic activity when pyrogallol was used as an electron donor. It is a hemoprotein containing one heme molecule per holomer and has an estimated molecular weight of 124,000 to 130,000. The catalase gene was cloned by screening a B. fragilis library for complementation of catalase activity in an Escherichia coli catalase mutant (katE katG) strain. The cloned gene, designated katB, encoded a catalase enzyme with electrophoretic mobility identical to that of the purified protein from the B. fragilis parental strain. The nucleotide sequence of katB revealed a 1,461-bp open reading frame for a protein with 486 amino acids and a predicted molecular weight of 55,905. This result was very close to the 60,000 Da determined by denaturing sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified catalase and indicates that the native enzyme is composed of two identical subunits. The N-terminal amino acid sequence of the purified catalase obtained by Edman degradation confirmed that it is a product of katB. The amino acid sequence of KatB showed high similarity to Haemophilus influenzae HktE (71.6% identity, 66% nucleotide identity), as well as to gram-positive bacterial and mammalian catalases. No similarities to bacterial catalase-peroxidase-type enzymes were found. The active-site residues, proximal and distal hemebinding ligands, and NADPH-binding residues of the bovine liver catalase-type enzyme were highly conserved in B. fragilis KatB. PMID:7768808

  2. Characterization of enterotoxigenic Bacteroides fragilis by a toxin-specific enzyme-linked immunosorbent assay.

    PubMed Central

    Van Tassell, R L; Lyerly, D M; Wilkins, T D

    1994-01-01

    Within the past decade, certain strains of Bacteroides fragilis have been associated with diarrhea in humans and cytotoxic activity on certain colon carcinoma cell lines. An enzyme-linked immunosorbent assay (ELISA) for detecting the enterotoxin of B. fragilis in cultures and stools was developed by using high-titer monospecific goat and rabbit antitoxins in an indirect format. The lower limit of detection for purified toxin was approximately 0.05 micrograms/ml; the linear range was from 0.05 to 10 microgram/ml. Using the ELISA to screen cultures of toxigenic and nontoxigenic strains of B. fragilis, we observed 100% correlation with 16 known toxigenic strains which had various cytotoxic activities on HT-29 cells. In addition, we found 6 of 62 previously untested strains also to be positive in both assays. Stability studies revealed that although the cytotoxic activities of crude and purified toxin preparations incubated at elevated temperatures were rapidly lost, the ELISA responses were not significantly reduced. Sodium dodecyl sulfate(SDS)-polyacrylamide gel electrophoresis and SDS-capillary electrophoresis showed that the purified toxin autodigested to several stable peptides. Studies on partially purified membranes from the toxigenic strains revealed the presence of several membrane-associated components which were noncytotoxic but strongly immunoreactive in the ELISA. Preliminary studies with spiked feces indicated that the ELISA may be useful for screening not only cultures for the enterotoxigenic B. fragilis but also stool specimens. Ongoing studies are focusing on determining the nature of the toxin's apparent proteolytic capabilities and investigating the feasibility of using the ELISA on stool specimens from healthy and diarrheic humans. Images PMID:8556504

  3. Polyethylene glycol-facilitated transformation of Bacteroides fragilis with plasmid DNA

    SciTech Connect

    Smith, C.J.

    1985-10-01

    A method for the transformation of Bacteroides fragilis with plasmid DNA was developed by using the clindamycin resistance plasmid pBFTM10 as the source of transforming DNA. The method was technically simple to perform and resulted in an average of 4.2 x 10/sup 3/ tranformants per ..mu..g of pBFTM10 added. A method for the preparation of frozen competent cells is also described.

  4. Frequency of specific agr groups and antibiotic resistance in Staphylococcus aureus isolated from bovine mastitis in the northeast of Iran.

    PubMed

    Mohsenzadeh, Mohammad; Ghazvini, Kiarash; Azimian, Amir

    2015-01-01

    Staphylococcus aureus is generally regarded as a leading cause of mastitis in dairy cattle. The aim of this study was to investigate the pattern of agr groups and any possible relationship between agr groups and antibiotic resistance among S. aureus strains isolated from bovine mastitis in Northeast of Iran. For this purpose, a total of 300 bovine mastitic milk samples were taken from dairy industry farms of Khorasan Razavi Province, Iran. S. aureus were isolated and identified according to the standard methods. Antibiotic susceptibility testing was conducted by disk diffusion method. In this study a total of 31 isolates of S. aureus were evaluated for agrD gene polymorphism by specific primers. Most of the isolates belonged to agr group I (54.8%), followed by agr group III (25.8%) and agr group II (19.4%). There was not any isolates belonging to group IV. Resistance to methicillin in agr group I isolates was more than other groups. Agr groups II and III were quite susceptible to methicillin. Due to high prevalent of S. aureus isolates and high antibiotic resistance rate in bovine mastitic isolates, it is important to verify the characteristics of S. aureus strains in Iran. PMID:26973764

  5. Frequency of specific agr groups and antibiotic resistance in Staphylococcus aureus isolated from bovine mastitis in the northeast of Iran

    PubMed Central

    Mohsenzadeh, Mohammad; Ghazvini, Kiarash; Azimian, Amir

    2015-01-01

    Staphylococcus aureus is generally regarded as a leading cause of mastitis in dairy cattle. The aim of this study was to investigate the pattern of agr groups and any possible relationship between agr groups and antibiotic resistance among S. aureus strains isolated from bovine mastitis in Northeast of Iran. For this purpose, a total of 300 bovine mastitic milk samples were taken from dairy industry farms of Khorasan Razavi Province, Iran. S. aureus were isolated and identified according to the standard methods. Antibiotic susceptibility testing was conducted by disk diffusion method. In this study a total of 31 isolates of S. aureus were evaluated for agrD gene polymorphism by specific primers. Most of the isolates belonged to agr group I (54.8%), followed by agr group III (25.8%) and agr group II (19.4%). There was not any isolates belonging to group IV. Resistance to methicillin in agr group I isolates was more than other groups. Agr groups II and III were quite susceptible to methicillin. Due to high prevalent of S. aureus isolates and high antibiotic resistance rate in bovine mastitic isolates, it is important to verify the characteristics of S. aureus strains in Iran. PMID:26973764

  6. Pyogenic arthritis of native joints due to Bacteroides fragilis: Case report and review of the literature.

    PubMed

    Nolla, Joan M; Murillo, Oscar; Narvaez, Javier; Vaquero, Carmen Gómez; Lora-Tamayo, Jaime; Pedrero, Salvador; Cabo, Javier; Ariza, Javier

    2016-06-01

    Pyogenic arthritis of native joints due to Bacteroides fragilis seems to be an infrequent disease. We analyzed the cases diagnosed in a tertiary hospital during a 22-year period and reviewed the literature to summarize the experience with this infectious entity.In our institution, of 308 patients with pyogenic arthritis of native joints, B fragilis was the causative organism in 2 (0.6%) cases. A MEDLINE search (1981-2015) identified 19 additional cases.Of the 21 patients available for review (13 men and 8 women, with a mean age, of 54.4 ± 17 years), 19 (90%) presented a systemic predisposing factor for infection; the most common associated illness was rheumatoid arthritis (8 patients). Bacteremia was documented in 65% (13/20) of cases. In 5 patients (24%), 1 or more concomitant infectious process was found. Metronidazole was the most frequently used antibiotic. Surgical drainage was performed in 11 cases (52%). The overall mortality rate was 5%.Pyogenic arthritis of native joints due to B fragilis is an infrequent disease that mainly affects elderly patients with underlying medical illnesses and in whom bacteremia and the presence of a concomitant infectious process are frequent conditions. PMID:27336895

  7. Different metabolic features of Bacteroides fragilis growing in the presence of glucose and exopolysaccharides of bifidobacteria.

    PubMed

    Rios-Covian, David; Sánchez, Borja; Salazar, Nuria; Martínez, Noelia; Redruello, Begoña; Gueimonde, Miguel; de Los Reyes-Gavilán, Clara G

    2015-01-01

    Bacteroides is among the most abundant microorganism inhabiting the human intestine. They are saccharolytic bacteria able to use dietary or host-derived glycans as energy sources. Some Bacteroides fragilis strains contribute to the maturation of the immune system but it is also an opportunistic pathogen. The intestine is the habitat of most Bifidobacterium species, some of whose strains are considered probiotics. Bifidobacteria can synthesize exopolysaccharides (EPSs), which are complex carbohydrates that may be available in the intestinal environment. We studied the metabolism of B. fragilis when an EPS preparation from bifidobacteria was added to the growth medium compared to its behavior with added glucose. 2D-DIGE coupled with the identification by MALDI-TOF/TOF evidenced proteins that were differentially produced when EPS was added. The results were supported by RT-qPCR gene expression analysis. The intracellular and extracellular pattern of certain amino acids, the redox balance and the α-glucosidase activity were differently affected in EPS with respect to glucose. These results allowed us to hypothesize that three general main events, namely the activation of amino acids catabolism, enhancement of the transketolase reaction from the pentose-phosphate cycle, and activation of the succinate-propionate pathway, promote a shift of bacterial metabolism rendering more reducing power and optimizing the energetic yield in the form of ATP when Bacteroides grow with added EPSs. Our results expand the knowledge about the capacity of B. fragilis for adapting to complex carbohydrates and amino acids present in the intestinal environment. PMID:26347720

  8. A proteomic approach towards understanding the cross talk between Bacteroides fragilis and Bifidobacterium longum in coculture.

    PubMed

    Rios-Covián, David; Sánchez, Borja; Martínez, Noelia; Cuesta, Isabel; Hernández-Barranco, Ana M; de Los Reyes-Gavilán, Clara G; Gueimonde, Miguel

    2016-07-01

    A better understanding of the interactions among intestinal microbes is needed to decipher the complex cross talk that takes place within the human gut. Bacteroides and Bifidobacterium genera are among the most relevant intestinal bacteria, and it has been previously reported that coculturing of these 2 microorganisms affects their survival. Therefore, coculturing of Bifidobacterium longum NB667 and Bacteroides fragilis DSMZ2151 was performed with the aim of unravelling the mechanisms involved in their interaction. To this end, we applied proteomic (2D-DIGE) analyses, and by chromatographic techniques we quantified the bacterial metabolites produced during coincubation. Coculture stimulated the growth of B. longum, retarding that of B. fragilis, with concomitant changes in the production of some proteins and metabolites of both bacteria. The combined culture promoted upregulation of the bifidobacterial pyruvate kinase and downregulation of the Bacteroides phosphoenolpyruvate carboxykinase - 2 enzymes involved in the catabolism of carbohydrates. Moreover, B. fragilis FKBP-type peptidyl-prolyl cis-trans isomerase, a protein with chaperone-like activity, was found to be overproduced in coculture, suggesting the induction of a stress response in this microorganism. This study provides mechanistic data to deepen our understanding of the interaction between Bacteroides and Bifidobacterium intestinal populations. PMID:27156738

  9. Different metabolic features of Bacteroides fragilis growing in the presence of glucose and exopolysaccharides of bifidobacteria

    PubMed Central

    Rios-Covian, David; Sánchez, Borja; Salazar, Nuria; Martínez, Noelia; Redruello, Begoña; Gueimonde, Miguel; de los Reyes-Gavilán, Clara G.

    2015-01-01

    Bacteroides is among the most abundant microorganism inhabiting the human intestine. They are saccharolytic bacteria able to use dietary or host-derived glycans as energy sources. Some Bacteroides fragilis strains contribute to the maturation of the immune system but it is also an opportunistic pathogen. The intestine is the habitat of most Bifidobacterium species, some of whose strains are considered probiotics. Bifidobacteria can synthesize exopolysaccharides (EPSs), which are complex carbohydrates that may be available in the intestinal environment. We studied the metabolism of B. fragilis when an EPS preparation from bifidobacteria was added to the growth medium compared to its behavior with added glucose. 2D-DIGE coupled with the identification by MALDI-TOF/TOF evidenced proteins that were differentially produced when EPS was added. The results were supported by RT-qPCR gene expression analysis. The intracellular and extracellular pattern of certain amino acids, the redox balance and the α-glucosidase activity were differently affected in EPS with respect to glucose. These results allowed us to hypothesize that three general main events, namely the activation of amino acids catabolism, enhancement of the transketolase reaction from the pentose-phosphate cycle, and activation of the succinate-propionate pathway, promote a shift of bacterial metabolism rendering more reducing power and optimizing the energetic yield in the form of ATP when Bacteroides grow with added EPSs. Our results expand the knowledge about the capacity of B. fragilis for adapting to complex carbohydrates and amino acids present in the intestinal environment. PMID:26347720

  10. Physiological compensation for environmental acidification is limited in the deep-sea urchin Strongylocentrotus fragilis

    NASA Astrophysics Data System (ADS)

    Taylor, J. R.; Lovera, C.; Whaling, P. J.; Buck, K. R.; Pane, E. F.; Barry, J. P.

    2013-05-01

    Anthropogenic CO2 is now reaching depths over 1000 m in the Eastern Pacific, overlapping the Oxygen Minimum Zone (OMZ). Deep-sea animals - particularly, calcifiers - are suspected to be especially sensitive to environmental acidification associated with global climate change. We have investigated the effects of hypercapnia and hypoxia on the deep-sea urchin Strongylocentrotus fragilis, during two long-term exposure experiments (1 month and 4 month) at three levels of reduced pH at in situ O2 levels of approx. 10% saturation, and also to control pH at 100% O2 saturation. During the first experiment, internal acid-base balance was investigated during a one-month exposure; results show S. fragilis has limited ability to compensate for the respiratory acidosis brought on by reduced pH, due in part to low non-bicarbonate extracellular fluid buffering capacity. During the second experiment, longer-term effects of hypercapnia and variable O2 on locomotion, feeding, growth, and gonadosomatic index (GSI) were investigated; results show significant mortality and correlation of all measured parameters with environmental acidification at pH 6.6. Transient adverse effects on locomotion and feeding were seen at pH 7.2, without compromise of growth or GSI. Based on the expected changes in ocean pH and oxygen, results suggest extinction of S. fragilis in the eastern North Pacific is unlikely. Rather, we expect a shoaling and contraction of its bathymetric range.

  11. Isolation of Naturally Occurring Viruses of the Murine Leukemia Virus Group in Tissue Culture

    PubMed Central

    Hartley, Janet W.; Rowe, Wallace P.; Capps, Worth I.; Huebner, Robert J.

    1969-01-01

    A tissue culture cell system for isolation and identification of members of the murine leukemia virus group (the complement fixation for murine leukemia test) was modified to permit the isolation of naturally occurring virus from leukemic and normal mice. The important factors for increasing the sensitivity of the test were the use of National Institutes of Health (NIH) strain Webster Swiss embryo cell cultures and the selection of rat-immune sera having complement-fixing antibodies to tissue culture antigens of both the Gross and FMR subgroups. In all, 163 strains of mouse leukemia virus, from 11 inbred mouse strains, have been isolated. Representative virus isolates were shown to possess the properties of the murine leukemia virus group; i.e., they were chloroform-sensitive, noncytopathic agents which replicated in mouse embryo tissue culture and produced group-reactive, complement-fixing antigen and budding C-type particles visible by electron microscopy. These viruses could serve as helpers in the rescue of Moloney sarcoma virus genome from non-producer hamster sarcoma cells, yielding pseudotypes. All of the 19 field isolates tested were neutralized by Gross passage A antiserum but not by potent antisera to the Moloney, Rauscher, and Friend strains. Virus was recovered regularly from embryos and from the plasma and spleen of adult mice of high leukemic strains. In low leukemic mouse strains, different patterns of virus detection were observed. In C3H/He mice, virus was occasionally present in embryos and was found in 40% of adult spleens. BALB/c mice were virus-negative as fetuses or weanlings, but spleens of more than half of the mice over 6 months of age yielded virus. NIH mice have never yielded virus. In reciprocal matings between AKR and BALB/c mice, virus recovery from embryos was maternally determined. The development of tissue culture isolation procedures made possible for the first time the application of classical infectious disease methods to the

  12. Distribution and sequence variations of selected virulence genes among group A streptococcal isolates from western Norway.

    PubMed

    Mylvaganam, H; Bjorvatn, B; Osland, A

    2000-11-01

    In order to compare the distribution of selected virulence genes among group A streptococci recovered from invasive disease and superficial infections, 42 isolates were screened for mga, speB, speA, ssa and ska, by PCR. The isolates were predominantly of the sequence types emm1, emm3 and emm6, but also included a few of the types emm22, emm28, emm75 and emm78. The phage-mediated speA seemed to be prevalent in emm types 1 and 3, and its distribution was not related to disease severity. The other genes were present in all isolates. The mga, speB and speA were further studied by sequence analysis. Although allotypic associations with invasiveness were not found, allelic specificity to the emm sequence type was observed. In addition, the mga sequences indicated two lineages, related to opacity factor production. A possible recombination between these two main divergent mga genes was observed in isolates of the types emm22 and emm75. A logical nomenclature of the alleles of mga and speB is suggested. PMID:11211972

  13. Antagonism of ampicillin and chloramphenicol for meningeal isolates of group B streptococci.

    PubMed Central

    Weeks, J L; Mason, E O; Baker, C J

    1981-01-01

    The increasing prevalence of ampicillin-resistant Haemophilus influenzae type b has led to the recommendation that ampicillin and chloramphenicol be given as the initial therapy for suspected bacterial meningitis in infants and children. However, during the first 2 months of life, H. influenzae type b is a rare cause of meningitis, whereas group B streptococcus is the most frequently isolated agent. Since ampicillin and chloramphenicol have been shown to be antagonistic for other streptococci, an in vitro study of their effect on group B streptococci was performed. The effect of ampicillin and chloramphenicol, alone and in combination, on 18 meningeal isolates was determined for 2 different inocula of group B streptococci, using microtiter broth dilution and growth kinetic assays. Isoboles, fractional lethal concentration indices, or both indicated antagonism for all strains. Growth kinetic assays for two representative strains demonstrated inhibition of the early bactericidal activity of ampicillin by chloramphenicol. These findings of in vitro antagonism suggest that this combination may be contraindicated for the treatment of infants with group B streptococcal meningitis. PMID:7030197

  14. Characterisation of the first actinobacterial group isolated from a Mexican extremophile environment.

    PubMed

    Quintana, Erika T; Badillo, Ricardo Flores; Maldonado, Luis A

    2013-07-01

    The "Cave of Crystals" (aka 'Naica') in Chihuahua Mexico is a natural unique subterranean ecosystem which mainly consists of crystals made of calcium sulfate. The main system of caves are found at a depth of 300 meters (m) below sea level with crystals that range in size from a few centimeters to 15 m. The crystals date from nearly 400,000 years old and are thought to be formed when the cave was fully covered by water. At present time, this place shows a nearly constant temperature of 55 °C over the year and a humidity of 100 % which makes this place incomparable and unbearable to animal and/or human life. In the present study, two actinobacterial groups were isolated from within this system of caves and subjected to a systematic study to establish their phylogenetic relationship to microorganisms belonging to this vast group of Gram positive bacteria. Phenotypic properties, chemotaxonomic and 16S rRNA gene sequencing show that the microorganisms are members of the family Pseudonocardiaceae and are most closely related to the genus Prauserella. The present study is the first to report the isolation and presence of Actinobacteria or any other microbial form of life in this exceptional place. Moreover, this unexpected biodiversity can also provide an insight of the antibiotic resistome present in the isolates reported in this study. PMID:23640690

  15. Differentiation and grouping of isolates of the Ganoderma lucidum complex by random amplified polymorphic DNA-PCR compared with grouping on the basis of internal transcribed spacer sequences.

    PubMed Central

    Hseu, R S; Wang, H H; Wang, H F; Moncalvo, J M

    1996-01-01

    Laccate polypores of the Ganoderma lucidum species complex are widespread white rot fungi of economic importance, but isolates cannot be identified by traditional taxonomic methods. Parsimony analysis of nucleotide sequences from the internal transcribed spacers (ITS) of the ribosomal gene (rDNA) distinguished six lineages in this species complex. Each ITS lineage may represent one or more putative species. While some isolates have identical ITS sequences, all of them could be clearly differentiated by genetic fingerprinting using random amplified polymorphic DNA (RAPD). To investigate the suitability of RAPD markers for taxonomic identification and grouping of isolates of the G. lucidum complex, RAPD fragments (RAPDs) were used as phenotypic characters in numerical and parsimony analyses. Results show that data from RAPDS do not distinguish the same clades as ITS data do. Groupings based on analysis of RAPD data were very sensitive to the choice of the grouping method used, and no consistent grouping of isolates could be proposed. However, analysis with RAPDs did resolve several robust terminal clades containing putatively conspecific isolates, suggesting that RAPDs might be helpful for systematics at the lower taxonomic levels that are unresolved by ITS sequence data. The limitations of RAPDs for systematics are briefly discussed. The conclusion of this study is that ITS sequences can be used to identify isolates of the G. lucidum complex, whereas RAPDs can be used to differentiate between isolates having identical ITS sequences. The practical implications of these results are briefly illustrated. PMID:8919797

  16. A new Streptococcus group A M-29 variant isolated during a suspected common-source epidemic.

    PubMed

    Gillis, D; Cohen, D; Beck, A; Rouach, T; Katzenelson, E; Green, M

    1992-06-01

    In the summer of 1988, a large epidemic of acute pharyngitis occurred in an Israeli military base. The clinical features were those of acute pharyngitis. The epidemic curve was characteristic of a common-source outbreak, possibly food-borne. Throat swabs from a sample of cases were positive for group A streptococci. Nine isolates from the epidemic were further evaluated at the local reference laboratory and serotyping showed that all were of the same strain with a distinct M protein that is a hitherto undescribed variant of M-29. We discuss the significance of unusual strains of beta-hemolytic Streptococcus appearing in food-borne outbreaks. PMID:1620392

  17. Molecular characterization of Streptococcus pyogenes group A isolates from a tertiary hospital in Lebanon.

    PubMed

    Karaky, Nathalie M; Araj, George F; Tokajian, Sima T

    2014-09-01

    Streptococcus pyogenes [Group A Streptococcus (GAS)] is one of the most important human pathogens, responsible for numerous diseases with diverse clinical manifestations. As the epidemiology of GAS infections evolves, a rapid and reliable characterization of the isolates remains essential for epidemiological analysis and infection control. This study investigated the epidemiological patterns and genetic characteristics of 150 GAS isolates from a tertiary hospital in Lebanon by emm typing, superantigens (SAgs) detection, PFGE and antibiotic profiling. The results revealed 41 distinct emm types, the most prevalent of which were emm89 (16 %), emm12 (10 %), emm2 (9 %) and emm1 (8 %). Testing for the presence of superantigens showed that speB (87 %), ssa (36 %) and speG (30 %) were predominant. PFGE detected 39 pulsotypes when a similarity cut-off value of 80 % was implemented. Antibiotic-susceptibility testing against seven different classes of antibiotics showed that 9 % of the isolates were resistant to clindamycin, 23 % were resistant to erythromycin and 4 % showed the macrolide-lincosamide-streptogramin B (MLSB) phenotype. The emergence of tetracycline-resistant strains (37 %) was high when compared with previous reports from Lebanon. This study provided comprehensive evidence of the epidemiology of GAS in Lebanon, highlighting the association between emm types and toxin genes, and providing valuable information about the origin and dissemination of this pathogen. PMID:24980572

  18. Isolation and purification of blood group antigens using immuno-affinity chromatography on short monolithic columns.

    PubMed

    Mönster, Andrea; Hiller, Oliver; Grüger, Daniela; Blasczyk, Rainer; Kasper, Cornelia

    2011-02-01

    Monolithic columns have gained increasing attention as stationary phases for the separation of biomolecules and biopharmaceuticals. In the present work the performance of monolithic convective interaction media (CIM(®)) chromatography for the purification of blood group antigens was established. The proteins employed in this study are derived from blood group antigens Knops, JMH and Scianna, equipped both with a His-tag and with a V5-tag by which they can be purified. In a first step a monoclonal antibody directed against the V5-tag was immobilized on a CIM(®) Disk with epoxy chemistry. After this, the immobilized CIM(®) Disk was used in immuno-affinity chromatography to purify the three blood group antigens from cell culture supernatant. Up-scaling of the applied technology was carried out using CIM(®) Tubes. In comparison to conventional affinity chromatography, blood group antigens were also purified via His-tag using a HiTrap(®) metal-affinity column. The two purifications have been compared regarding purity, yield and purification speed. Using the monolithic support, it was possible to isolate the blood group antigens with a higher flow rate than using the conventional bed-packed column. PMID:21194702

  19. Viridans Group Streptococci Clinical Isolates: MALDI-TOF Mass Spectrometry versus Gene Sequence-Based Identification

    PubMed Central

    Angeletti, Silvia; Dicuonzo, Giordano; Avola, Alessandra; Crea, Francesca; Dedej, Etleva; Vailati, Francesca; Farina, Claudio; De Florio, Lucia

    2015-01-01

    Viridans Group Streptococci (VGS) species-level identification is fundamental for patients management. Matrix-assisted laser desorption ionization—time of flight mass spectrometry (MALDI-TOF MS) has been used for VGS identification but discrimination within the Mitis group resulted difficult. In this study, VGS identifications with two MALDI-TOF instruments, the Biotyper (Bruker) and the VITEK MS (bioMérieux) have been compared to those derived from tuf, soda and rpoB genes sequencing. VGS isolates were clustered and a dendrogram constructed using the Biotyper 3.0 software (Bruker). RpoB gene sequencing resulted the most sensitive and specific molecular method for S. pneumonia identification and was used as reference method. The sensitivity and the specificity of the VITEK MS in S. pneumonia identification were 100%, while the Biotyper resulted less specific (92.4%). In non pneumococcal VGS strains, the group-level correlation between rpoB and the Biotyper was 100%, while the species-level correlation was 61% after database upgrading (than 37% before upgrading). The group-level correlation between rpoB and the VITEK MS was 100%, while the species-level correlation was 36% and increases at 69% if isolates identified as S. mitis/S. oralis are included. The less accurate performance of the VITEK MS in VGS identification within the Mitis group was due to the inability to discriminate between S. mitis and S. oralis. Conversely, the Biotyper, after the release of the upgraded database, was able to discriminate between the two species. In the dendrogram, VGS strains from the same group were grouped into the same cluster and had a good correspondence with the gene-based clustering reported by other authors, thus confirming the validity of the upgraded version of the database. Data from this study demonstrated that MALDI-TOF technique can represent a rapid and cost saving method for VGS identification even within the Mitis group but improvements of spectra database are

  20. Antibiotic susceptibility patterns and prevalence of group B Streptococcus isolated from pregnant women in Misiones, Argentina

    PubMed Central

    Quiroga, M.; Pegels, E.; Oviedo, P.; Pereyra, E.; Vergara, M.

    2008-01-01

    This study was performed to determine the susceptibility patterns and the colonization rate of Group B Streptococcus (GBS) in a population of pregnant women. From January 2004 to December 2006, vaginal-rectal swabs were obtained from 1105 women attending Dr. Ramón Madariaga Hospital, in Posadas, Misiones, Argentina. The carriage rate of GBS among pregnant women was 7.6%. A total of 62 GBS strains were randomly selected for in vitro susceptibility testing to penicillin G, ampicillin, tetracycline, levofloxacin, gatifloxacin, ciprofloxacin, quinupristin-dalfopristin, linezolid, vancomycin, rifampicin, trimethoprim- sulfametoxazol, nitrofurantoin, gentamicin, clindamycin and erythromycin, and determination of resistance phenotypes. No resistance to penicillin, ampicillin, quinupristin-dalfopristin, linezolid, and vancomycin was found. Of the isolates examined 96.8%, 98.3%, 46.8%, and 29.0% were susceptible to rifampicin, nitrofurantoin, trimethoprim-sulfametoxazol and tetracycline, respectively. Rank order of susceptibility for the quinolones was: gatifloxacin (98.4%) > levofloxacin (93.5%) > ciprofloxacin (64.5%). The rate of resistance to erythromycin (9.7%) was higher than that of other reports from Argentina. High-level resistance to gentamicin was not detected in any of the isolates. Based on our finding of 50% of GBS isolates with MIC to gentamicin equal o lower than 8 μg/ml, a concentration used in one of the selective media recommended for GBS isolation, we suggested, at least in our population, the use of nalidixic acid and colistin in selective media with the aim to improve the sensitivity of screening cultures for GBS carriage in women. PMID:24031210

  1. Assignment of Colletotrichum coccodes isolates into vegetative compatibility groups using infrared spectroscopy: a step towards practical application.

    PubMed

    Salman, A; Shufan, E; Lapidot, I; Tsror, L; Moreh, R; Mordechai, S; Huleihel, M

    2015-05-01

    Colletotrichum coccodes (C. coccodes) is a pathogenic fungus that causes anthracnose on tomatoes and black dot disease in potatoes. It is considered as a seed tuber and soil-borne pathogen that is difficult to control. C. coccodes isolates are classified into Vegetative Compatibility Groups (VCGs). Early classification of isolates into VCGs is of great importance for a better understanding of the epidemiology of the disease and improving its control. Moreover, the differentiation among these isolates and the assignment of newly-discovered isolates enable control of the disease at its early stages. Distinguishing between isolates using microbiological or genetic methods is time-consuming and not readily available. Our results show that it is possible to assign the isolates into their VCGs and to classify them at the isolate level with a high success rate using Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA). PMID:25790802

  2. Freezing tolerance and water relations of Opuntia fragilis from Canada and the United States

    SciTech Connect

    Loik, M.E.; Nobel, P.S. )

    1993-09-01

    To investigate the influence of winter climate on freezing tolerance at the population level, minimum January air temperatures in the field and cold acclimation determined in the laboratory were compared for Opuntia fragilis. Populations occurred at 20 locations as far north as 56[degrees]46' N latitude and at elevations up to 3029 m in Canada and the United States, most of which experience extreme freezing temperatures each winter. Low-temperature responses and water relations of stems were examined in the laboratory at day/night air temperatures of 25[degrees]/15[degrees]C and 14 d after the plants were shifted to a 5[degrees]/[minus]5[degrees]C temperature cycle. Cold acclimation averaged 17[degrees]C and freezing tolerance averaged [minus]29[degrees]C for the 20 populations following a shift to low day/night air temperatures, indicating that O. fragilis has the greatest cold acclimation ability and the greatest freezing tolerance reported for any cactus. Moreover, freezing tolerance and cold acclimation were both positively correlated (r[sup 2] [congruent] 0.7) with the minimum temperatures at the 20 locations. Plants lost water during low-temperature acclimation, leading to 30% decreases in cladode and chlorenchyma thickness; the decrease in water content was greater for the five warmest populations than for the five coldest ones. Over the same period, the average osmotic pressure of the chlorenchyma increased from 1.42 to 1.64 MPa, and the relative water content (RWC) decreased from 0.58 to 0.49, but the average osmotic pressure of saturated chlorenchyma was unchanged, indicating no net change in solute content during acclimation. Although the role of water relations in freezing tolerance is unclear, the substantial freezing tolerance and cold acclimation ability of O. fragilis leads to its distribution into regions of Canada and the United States that experience minimum temperatures below [minus]40[degrees]C during the winter. 47 refs., 3 figs., 5 tabs.

  3. UDP-Glucuronic Acid Decarboxylases of Bacteroides fragilis and Their Prevalence in Bacteria▿†

    PubMed Central

    Coyne, Michael J.; Fletcher, C. Mark; Reinap, Barbara; Comstock, Laurie E.

    2011-01-01

    Xylose is rarely described as a component of bacterial glycans. UDP-xylose is the nucleotide-activated form necessary for incorporation of xylose into glycans and is synthesized by the decarboxylation of UDP-glucuronic acid (UDP-GlcA). Enzymes with UDP-GlcA decarboxylase activity include those that lead to the formation of UDP-xylose as the end product (Uxs type) and those synthesizing UDP-xylose as an intermediate (ArnA and RsU4kpxs types). In this report, we identify and confirm the activities of two Uxs-type UDP-GlcA decarboxylases of Bacteroides fragilis, designated BfUxs1 and BfUxs2. Bfuxs1 is located in a conserved region of the B. fragilis genome, whereas Bfuxs2 is in the heterogeneous capsular polysaccharide F (PSF) biosynthesis locus. Deletion of either gene separately does not result in the loss of a detectable phenotype, but deletion of both genes abrogates PSF synthesis, strongly suggesting that they are functional paralogs and that the B. fragilis NCTC 9343 PSF repeat unit contains xylose. UDP-GlcA decarboxylases are often annotated incorrectly as NAD-dependent epimerases/dehydratases; therefore, their prevalence in bacteria is underappreciated. Using available structural and mutational data, we devised a sequence pattern to detect bacterial genes encoding UDP-GlcA decarboxylase activity. We identified 826 predicted UDP-GlcA decarboxylase enzymes in diverse bacterial species, with the ArnA and RsU4kpxs types confined largely to proteobacterial species. These data suggest that xylose, or a monosaccharide requiring a UDP-xylose intermediate, is more prevalent in bacterial glycans than previously appreciated. Genes encoding BfUxs1-like enzymes are highly conserved in Bacteroides species, indicating that these abundant intestinal microbes may synthesize a conserved xylose-containing glycan. PMID:21804000

  4. Multispacer Typing (MST) of Spotted Fever Group Rickettsiae Isolated from Humans and Rats in Chengmai County, Hainan Province, China.

    PubMed

    Cheng, Xueqin; Jin, Yuming; Lao, Shijun; Huang, Changhe; Huang, Fang; Jia, Pengben; Zhang, Lijuan

    2014-09-01

    Spotted fever caused by spotted fever group rickettsiae (SFGR) is found throughout China. During 2007-2008, 28 human SFGR isolates and 34 rat SFGR isolates including 15 isolates from Rattus fulvescens, 5 isolates from R. edwardsi, 7 isolates from Callosciurus erythraeus roberti and 7 isolates from Dremomys rufigenis) were obtained from L929 cell culture. Previous research indicated that the 62 strains of SFGR mentioned above shared not only the same serophenotype but also 100% of identity sequences of 16S rRNA, gltA, ompA, groEL and 17KD, which enabled us to apply multispacer typing (MST) to the 62 SFGR isolates in the study. Six primer pairs, which were used for typing of Rickettsia rickettsii and Rickettsia conorii, were chosen, and the results exhibited greater nucleotide polymorphisms among the 62 isolates tested. A total of 48 distinct genotypes were identified. The dominant genotype, represented by h3 isolates, accounted for 21.7% (13/60) of the isolates tested, and the remaining 47 genotypes were all unique. Phylogenetic analysis showed that all the 48 genotypes could be classified in the same clade, while the genetically related strain, R. heilongjiangensis, was close but not the same as the cluster. We concluded that the genetically diverse of spotted fever group rickettsiae strains are endemic in Chengmai County, Hainan Province, China. PMID:25324688

  5. Cloacal aerobic bacterial flora and absence of viruses in free-living slow worms (Anguis fragilis), grass snakes (Natrix natrix) and European Adders (Vipera berus) from Germany.

    PubMed

    Schmidt, Volker; Mock, Ronja; Burgkhardt, Eileen; Junghanns, Anja; Ortlieb, Falk; Szabo, Istvan; Marschang, Rachel; Blindow, Irmgard; Krautwald-Junghanns, Maria-Elisabeth

    2014-12-01

    Disease problems caused by viral or bacterial pathogens are common in reptiles kept in captivity. There is no information available on the incidence of viral pathogens or the physiological cloacal bacterial flora of common free-living reptiles in Germany. Therefore, 56 free-living reptiles including 23 European adders (Vipera berus), 12 grass snakes (Natrix natrix) and 21 slow worms (Anguis fragilis) were investigated on the island Hiddensee in northeastern Germany. Pharyngeal and cloacal swabs were taken immediately after capture. Bacteriological examination was performed from the cloacal swabs to study the aerobic cloacal flora. Molecular biological examination included amplification of DNA or RNA from adeno-, rana- and ferlaviruses as well as culturing on Russell's viper heart cells for virus isolation. Salmonella spp. were isolated from European adders but not from the other reptiles examined. The minimal inhibitory concentration was determined from the isolated Salmonella spp. However, some potentially human pathogenic bacteria, such as Proteus vulgaris, Aeromonas hydrophila, Klebsiella pneumoniae and Escherichia coli were isolated. Viruses were not detected in any of the examined reptiles. To the authors' best knowledge, the present study is the first survey of viral pathogens in free-living snakes and slow worms in Germany and the first survey of cloacal aerobic bacterial flora of slow worms. PMID:24866333

  6. Efflux Pump Overexpression in Multiple-Antibiotic-Resistant Mutants of Bacteroides fragilis

    PubMed Central

    Pumbwe, Lilian; Glass, Daniel; Wexler, Hannah M.

    2006-01-01

    Multidrug-resistant mutants of a wild-type Bacteroides fragilis strain (strain ADB77) and a quadruple resistance nodulation division family efflux pump deletion mutant (ADB77 ΔbmeB1 ΔbmeB3 ΔbmeB12 ΔbmeB15) were selected with antimicrobials. Ampicillin, doripenem, imipenem, levofloxacin, and metronidazole selected for mutants from both strains; cefoxitin selected for mutants from strain ADB77 only; and sodium dodecyl sulfate selected mutants from ADB77ΔbmeB1 ΔbmeB3 ΔbmeB12 ΔbmeB15 only. The mutants overexpressed one or more efflux pumps. PMID:16940115

  7. Exploring dinosaur neuropaleobiology: viewpoint computed tomography scanning and analysis of an Allosaurus fragilis endocast.

    PubMed

    Rogers, S W

    1998-10-01

    The unique opportunity to examine an exceptionally well-preserved natural endocranial cast (endocast) from a carnivorous dinosaur of the late Jurassic period, Allosaurus fragilis, was afforded this neurobiologist. The endocast exhibits numerous surface features including the complete vestibular apparatus. Spiral computed tomography scanning revealed multiple internal features including putative blood vessels, connective tissue-like arrays, and a prominent symmetrical density consistent with the putative brain or its cast. The evidence suggests that this organism's neurobiology resembled closely that of modern crocodylian species and should be included for consideration when examining ideas of Allosaurus evolution, behavior, and eventual extinction. PMID:9808455

  8. Application of Bacteroides fragilis phage as an alternative indicator of sewage pollution in Tampa Bay, Florida

    USGS Publications Warehouse

    McLaughlin, M.R.; Rose, J.B.

    2006-01-01

    Traditional fecal coliform bacterial indicators have been found to be severely limited in determining the significance and sources of fecal contamination in ambient waters of tropical and subtropical regions. The bacteriophages that infect Bacteroides fragilis have been suggested as better fecal indicators and at least one type may be human specific. In this study, the phages that infect B. fragilis host RYC2056 (RYC), including phage B56-3, and host ATCC 51477-HSP40 (HSP), including the human specific phage B40-8, were evaluated in the drainage basins of Tampa Bay, 7 samples (n = 62), or 11%, tested positive for the presence of phages infecting the host HSP, whereas 28 samples, or 45%, tested positive using the host RYC. A survival study was also done to compare the persistence of phages B56-3 and B40-8 to MS2 coliphage in seawater at various temperatures. The decay rates for MS2 were 0.239 log 10 d-1 at 10??C, but increased to 0.896 at 20??C and 2.62 log10 d-1 at 30??C. The two B. fragilis phages persisted much longer in the seawater compared to the coliphage and showed little variation between the temperatures. All sewage influents sampled from area wastewater treatment plants contained phages that infected the two B. fragilis hosts at levels from 1.2 ?? 104 to 1.11 ?? 10 5 pfu 100 ml-1 for host RYC and 67 to 350 pfu 100 ml -1 for host HSP. Of the 7 chlorinated effluent samples tested, 3 were positive for the presence of the phage using the host RYC and the phage enrichment method, with levels estimated to be <10 pfu 100 ml-1. No phages were detected using the host HSP in the treated sewage effluent. Coliphages were found in 3 of the 7 effluent samples at a range of 30 to 1.2 ?? 103 pfu 100 ml-1. ?? 2006 Estuarine Research Federation.

  9. Demographic Histories, Isolation and Social Factors as Determinants of the Genetic Structure of Alpine Linguistic Groups

    PubMed Central

    Coia, Valentina; Capocasa, Marco; Anagnostou, Paolo; Pascali, Vincenzo; Scarnicci, Francesca; Boschi, Ilaria; Battaggia, Cinzia; Crivellaro, Federica; Ferri, Gianmarco; Alù, Milena; Brisighelli, Francesca; Busby, George B. J.; Capelli, Cristian; Maixner, Frank; Cipollini, Giovanna; Viazzo, Pier Paolo; Zink, Albert; Destro Bisol, Giovanni

    2013-01-01

    Great European mountain ranges have acted as barriers to gene flow for resident populations since prehistory and have offered a place for the settlement of small, and sometimes culturally diverse, communities. Therefore, the human groups that have settled in these areas are worth exploring as an important potential source of diversity in the genetic structure of European populations. In this study, we present new high resolution data concerning Y chromosomal variation in three distinct Alpine ethno-linguistic groups, Italian, Ladin and German. Combining unpublished and literature data on Y chromosome and mitochondrial variation, we were able to detect different genetic patterns. In fact, within and among population diversity values observed vary across linguistic groups, with German and Italian speakers at the two extremes, and seem to reflect their different demographic histories. Using simulations we inferred that the joint effect of continued genetic isolation and reduced founding group size may explain the apportionment of genetic diversity observed in all groups. Extending the analysis to other continental populations, we observed that the genetic differentiation of Ladins and German speakers from Europeans is comparable or even greater to that observed for well known outliers like Sardinian and Basques. Finally, we found that in south Tyroleans, the social practice of Geschlossener Hof, a hereditary norm which might have favored male dispersal, coincides with a significant intra-group diversity for mtDNA but not for Y chromosome, a genetic pattern which is opposite to those expected among patrilocal populations. Together with previous evidence regarding the possible effects of “local ethnicity” on the genetic structure of German speakers that have settled in the eastern Italian Alps, this finding suggests that taking socio-cultural factors into account together with geographical variables and linguistic diversity may help unveil some yet to be understood

  10. Phylogenetic grouping and pathotypic comparison of urine and fecal Escherichia coli isolates from children with urinary tract infection

    PubMed Central

    Navidinia, Masoumeh; Peerayeh, Shahin Najar; Fallah, Fatemeh; Bakhshi, Bita; Sajadinia, Raheleh Sadat

    2014-01-01

    The aim of this study was to investigate the phylogenetic background and to assess hlyD (involved in the secretion of haemolysin A) and intI1 (encoding a class 1 integrase) in Escherichia coli isolates derived from urinary and fecal specimens. A total of 200 E. coli isolates was collected from patients presenting with urinary tract infection (UTI) during September 2009 to September 2010 and screened for hlyD and intI1 genes by polymerase chain reaction (PCR). Phylogenetic analysis showed that E. coli is composed of four main phylogenetic groups (A, B1, B2 and D) and that uropathogenic E. coli (UPEC) isolates mainly belong to groups B2 (54%) and D (34%) whereas group A (44%) and D (26%) are predominant among commensal E. coli isolates. In this study, hlyD was present in 26% of UPEC and 2% of commensal E. coli isolates. However, hemolytic activity was detected for 42% of UPEC and 6% of commensal E. coli isolates (p < 0.05). intI1 gene was more frequently expressed in UPEC (24%) in comparison with commensal E. coli isolates (12%). Resistance to aztreonam, co-trimoxazole and cefpodoxime were frequently found among UPEC isolates whereas commensal E. coli isolates were commonly resistant to co-trimoxazole, nalidixic acid and cefotaxime. Concluding, a considerable difference between UPEC and commensal E. coli isolates was observed regarding their phylogenetic groups, presence of class 1 integron and hlyD gene, hemolysin activity and resistance pattern. The detection of class 1 integrons and hlyD gene was higher among UPEC compared with commensal E. coli isolates. These findings may contribute for a better understanding of the factors involved in the pathogenesis of UPEC. PMID:25242935

  11. Virulence Gene Pool Detected in Bovine Group C Streptococcus dysgalactiae subsp. dysgalactiae Isolates by Use of a Group A S. pyogenes Virulence Microarray ▿

    PubMed Central

    Rato, Márcia G.; Nerlich, Andreas; Bergmann, René; Bexiga, Ricardo; Nunes, Sandro F.; Vilela, Cristina L.; Santos-Sanches, Ilda; Chhatwal, Gursharan S.

    2011-01-01

    A custom-designed microarray containing 220 virulence genes of Streptococcus pyogenes (group A Streptococcus [GAS]) was used to test group C Streptococcus dysgalactiae subsp. dysgalactiae (GCS) field strains causing bovine mastitis and group C or group G Streptococcus dysgalactiae subsp. equisimilis (GCS/GGS) isolates from human infections, with the latter being used for comparative purposes, for the presence of virulence genes. All bovine and all human isolates carried a fraction of the 220 genes (23% and 39%, respectively). The virulence genes encoding streptolysin S, glyceraldehyde-3-phosphate dehydrogenase, the plasminogen-binding M-like protein PAM, and the collagen-like protein SclB were detected in the majority of both bovine and human isolates (94 to 100%). Virulence factors, usually carried by human beta-hemolytic streptococcal pathogens, such as streptokinase, laminin-binding protein, and the C5a peptidase precursor, were detected in all human isolates but not in bovine isolates. Additionally, GAS bacteriophage-associated virulence genes encoding superantigens, DNase, and/or streptodornase were detected in bovine isolates (72%) but not in the human isolates. Determinants located in non-bacteriophage-related mobile elements, such as the gene encoding R28, were detected in all bovine and human isolates. Several virulence genes, including genes of bacteriophage origin, were shown to be expressed by reverse transcriptase PCR (RT-PCR). Phylogenetic analysis of superantigen gene sequences revealed a high level (>98%) of identity among genes of bovine GCS, of the horse pathogen Streptococcus equi subsp. equi, and of the human pathogen GAS. Our findings indicate that alpha-hemolytic bovine GCS, an important mastitis pathogen and considered to be a nonhuman pathogen, carries important virulence factors responsible for virulence and pathogenesis in humans. PMID:21525223

  12. Evaluation of Three Diagnostic Methods, Including Real-Time PCR, for Detection of Dientamoeba fragilis in Stool Specimens

    PubMed Central

    Stark, D.; Beebe, N.; Marriott, D.; Ellis, J.; Harkness, J.

    2006-01-01

    Dientamoeba fragilis is a protozoan parasite of humans that infects the mucosa of the large intestine and is associated with gastrointestinal disease. We developed a 5′ nuclease (TaqMan)-based real-time PCR assay, targeting the small subunit rRNA gene, for the detection of D. fragilis in human stool specimens and compared its sensitivity and specificity to conventional PCR and microscopic examination by a traditional modified iron-hematoxylin staining procedure. Real-time PCR exhibited 100% sensitivity and specificity. PMID:16390978

  13. Strain Diversity of Pseudomonas fluorescens Group with Potential Blue Pigment Phenotype Isolated from Dairy Products.

    PubMed

    Chierici, Margherita; Picozzi, Claudia; La Spina, Marisa Grazia; Orsi, Carla; Vigentini, Ileana; Zambrini, Vittorio; Foschino, Roberto

    2016-08-01

    The blue discoloration in Mozzarella cheese comes from bacterial spoilage due to contamination with Pseudomonas. Fourteen Pseudomonas fluorescens strains from international collections and 55 new isolates of dominant bacterial populations from spoiled fresh cheese samples were examined to assess genotypic and phenotypic strain diversity. Isolates were identified by 16S rRNA gene sequencing and tested for the production of the blue pigment at various temperatures on Mascarpone agar and in Mozzarella preserving fluid (the salty water in which the cheese is conserved, which becomes enriched by cheese minerals and peptides during storage). Pulsed-field gel electrophoresis analysis after treatment with the endonuclease SpeI separated the isolates into 42 genotypes at a similarity level of 80%. Based on the pulsotype clustering, 12 representative strains producing the blue discoloration were chosen for the multilocus sequence typing targeting the gyrB, glnS, ileS, nuoD, recA, rpoB, and rpoD genes. Four new sequence typing profiles were discovered, and the concatenated sequences of the investigated loci grouped the tested strains into the so-called ''blue branch'' of the P. fluorescens phylogenetic tree, confirming the linkage between pigment production and a specific genomic cluster. Growth temperature affected pigment production; the blue discoloration appeared at 4 and 14°C but not at 30°C. Similarly, the carbon source influenced the phenomenon; the blue phenotype was generated in the presence of glucose but not in the presence of galactose, sodium succinate, sodium citrate, or sodium lactate. PMID:27497132

  14. The enhancement of biofilm formation in Group B streptococcal isolates at vaginal pH.

    PubMed

    Ho, Yueh-Ren; Li, Chien-Ming; Yu, Chen-Hsiang; Lin, Yuh-Jyh; Wu, Ching-Ming; Harn, I-Chen; Tang, Ming-Jer; Chen, Yi-Ting; Shen, Fang-Chi; Lu, Chien-Yi; Tsai, Tai-Chun; Wu, Jiunn-Jong

    2013-04-01

    Group B streptococcus (GBS) is a common asymptomatic colonizer in acidic vagina of pregnant women and can transmit to newborns, causing neonatal pneumonia and meningitis. Biofilm formation is often associated with bacterial colonization and pathogenesis. Little is known about GBS biofilm and the effect of environmental stimuli on their growth along with biofilm formation. The objective of this study was to investigate the survival and biofilm formation of GBS, isolated from pregnant women, in nutrient-limited medium under various pH conditions. Growth and survival experiments were determined by optical density and viable counts. Crystal violet staining, scanning electron microscopy, and atomic force microscopy (AFM) were used to analyze the capacity of biofilm production. Our results showed that GBS isolates proliferated with increasing pH with highest maximum specific growth rate (μmax) at pH 6.5, but survived at pH 4.5 for longer than 48 h. Biofilm formation of the 80 GBS isolates at pH 4.5 was significantly higher than at pH 7.0. This difference was confirmed by two other methods. The low elastic modulus obtained from samples at pH 4.5 by AFM revealed the softness of biofilm; in contrast, little or no biofilm was measured at pH 7.0. Under acidic pH, the capability of biofilm formation of serotypes III and V showed statistically significant difference from serotypes Ia and Ib. Our finding suggested that survival and enhanced biofilm formation at vaginal pH are potentially advantageous for GBS in colonizing vagina and increase the risk of vaginosis and neonatal infection. PMID:22797522

  15. PCR detection of cytK gene in Bacillus cereus group strains isolated from food samples.

    PubMed

    Oltuszak-Walczak, Elzbieta; Walczak, Piotr

    2013-11-01

    A method for detection of the cytotoxin K cytK structural gene and its active promoter preceded by the PlcR-binding box, controlling the expression level of this enterotoxin, was developed. The method was applied for the purpose of the analysis of 47 bacterial strains belonging to the Bacillus cereus group isolated from different food products. It was found that the majority of the analyzed strains carried the fully functional cytK gene with its PlcR regulated promoter. The cytK gene was not detected in four emetic strains of Bacillus cereus carrying the cesB gene and potentially producing an emetic toxin - cereulide. The cytotoxin K gene was detected in 4 isolates classified as Bacillus mycoides and one reference strain B. mycoides PCM 2024. The promoter region and the N-terminal part of the cytK gene from two strains of B. mycoides (5D and 19E) showed similarities to the corresponding sequences of Bacillus cereus W23 and Bacillus thuringiensis HD-789, respectively. It was shown for the first time that the cytK gene promoter region from strains 5D and 19E of Bacillus mycoides had a similar arrangement to the corresponding sequence of Bacillus cereus ATCC 14579. The presence of the cytK gene in Bacillus mycoides shows that this species, widely recognized as nonpathogenic, may pose potential biohazard to human beings. PMID:24060693

  16. Group A streptococcal strains isolated in Lao People's Democratic Republic from 2004 to 2013.

    PubMed

    Rattanavong, S; Dance, D A B; Davong, V; Baker, C; Frost, H; Phetsouvanh, R; Vongsouvath, M; Newton, P N; Steer, A C; Smeesters, P R

    2016-06-01

    Epidemiological data regarding group A streptococcal (GAS) infections in South East Asia are scarce with no information from Laos. We characterized emm types, emm clusters and the antibiotic resistance profile of 124 GAS isolates recovered in Laos during 2004-2013. Most strains were recovered from skin and invasive infections (76% and 19%, respectively). Thirty-four emm types were identified as belonging to 12 emm clusters and no novel emm types were identified. No significant differences were observed in the distribution of emm types or emm clusters according to age or site of recovery (skin or invasive infections). There was moderate strain diversity in this country but considerable differences in emm-type distribution between Laos, Thailand and Cambodia. Vaccine coverage was high for the J8 vaccine candidate. The theoretical coverage for the 30-valent vaccine candidate needs further investigation. Antibiotic resistance was moderate to erythromycin and chloramphenicol (8% and 7%, respectively) and low to ofloxacin (<1%). PMID:26645633

  17. Bacteroides fragilis enterotoxin induces cytoskeletal changes and surface blebbing in HT-29 cells.

    PubMed Central

    Donelli, G; Fabbri, A; Fiorentini, C

    1996-01-01

    Certain strains of the anaerobic bacterium Bacteroides fragilis are known to produce an enterotoxin of about 20 kDa which is able to induce a fluid response in ligated intestinal loops and a cytotoxic response in HT-29 cells. It presents protease activity, belonging to a family of metalloproteases termed metzincins. In order to investigate the mode of action of the enterotoxin in cultured cells, we performed a study with HT-29 cells, using both fluoresence and electron microscopy. Treated cells underwent morphological changes, mainly consisting of the retraction of the cell body and the formation of numerous blebs on the cell surface. The microfilament system was reorganized, the F-actin being condensed as a ring at the cell periphery, whereas other cell organelles appeared to be unaffected. All these changes, clearly visible after 3 h of exposure to the toxin, were reversed within 24 h of treatment. By inhibiting the protease activity of the toxin with specific metal chelators, the cytoskeletal effects were also prevented. Thus, B. fragilis enterotoxin appears to act on cells by reversibly modifying the actin cytoskeleton, an effect probably dependent on its proteolytic activity. PMID:8557328

  18. Adolescents' Information Behavior When Isolated from Peer Groups: Lessons from New Immigrant Adolescents' Everyday Life Information Seeking

    ERIC Educational Resources Information Center

    Koo, Joung Hwa

    2013-01-01

    Purpose: The purpose of this study is to investigate how isolated immigrant adolescents seek and use necessary information when they are not able to use significant information sources--their peer groups--in the period of transition before new peer groups are established. Method: To achieve the study's purpose, sixteen recently arrived (three…

  19. Antimicrobial resistance among Pseudomonas spp. and the Bacillus cereus group isolated from Danish agricultural soil.

    PubMed

    Jensen, L B; Baloda, S; Boye, M; Aarestrup, F M

    2001-06-01

    From four Danish pig farms, bacteria of Pseudomonas spp. and the Bacillus cereus group were isolated from soil and susceptibility towards selected antimicrobials was tested. From each farm, soil samples representing soil just before and after spread of animal waste and undisturbed agricultural soil, when possible, were collected. Soil from a well-characterized Danish farm soil (Højbakkegaard) was collected for comparison. The Pseudomonas spp. and B. cereus were chosen as representative for Gram-negative and Gram-positive indigenous soil bacteria to test the effect of spread of animal waste on selection of resistance among soil bacteria. No variations in resistance levels were observed between farms; but when the four differently treated soils were compared, resistance was seen for carbadox, chloramphenicol, nalidixan (nalidixic acid), nitrofurantoin, streptomycin and tetracycline for Pseudomonas spp., and for bacitracin, erythromycin, penicillin and streptomycin for the B. cereus group. Variations in resistance levels were observed when soil before and after spread of animal waste was compared, indicating an effect from spread of animal waste. PMID:11485227

  20. [The suicide phenomenon and fermentative metabolic activity in strains of the Aeromonas group isolated from feces].

    PubMed

    Reina, J; Serra, A; Borrell, N; Gómez, J

    1992-11-01

    We study the "suicide" phenomena as well as metabolic pathways of mixed acids (methyl red test, MR) and butylene glycol (Voges-Proskauer, VP), in 107 strains belonging to mesophilic Aeromonas group, isolated from stools. The strains have been identified as A. hydrophila, 28 cases (26.1%), A. sobria 26 cases (24.3%) and A. caviae 53 cases (49.6%). All A. caviae strains behave homogeneously as F+, RM+ and VP-, independently of temperature (30 or 37 degrees C). A. hydrophila strains only showed their trend to "suicide" at 37 degrees C, being this behavior linked to RM test positivity. At 30 degrees C all strains were NS and RM-, keeping always positive the VP test (both temperatures). In A. sobria we have recorded changes in their behavior related to the temperature of incubation. At 37 degrees C, 57.7% were NS, whereas at 30 degrees C, 69.2% showed the same phenotype. The metabolic activity had remained stable, therefore F+ strains were VP and RM+, and NS strains were VP+ and RM-. It seems that FS is a phenotypic behavior of this bacterial group species and temperature-dependent, and also is related to a fermentative metabolic activity modulation of each of them. PMID:1489794

  1. Effect of distance from the polluting focus on relative concentrations of Bacteroides fragilis phages and coliphages in mussels.

    PubMed Central

    Lucena, F; Lasobras, J; McIntosh, D; Forcadell, M; Jofre, J

    1994-01-01

    Concentrations of fecal bacteria, somatic and F-specific coliphages, and phages infecting Bacteroides fragilis in naturally occurring black mussels (Mytilus edulis) were determined. Mussels were collected over a 7-month period at four sampling sites with different levels of fecal pollution. Concentrations of both fecal bacteria and bacteriophages in mussel meat paralleled the concentration of fecal bacteria in the overlying waters. Mussels bioaccumulated efficiently, although with different efficiencies, all of the microorganisms studied. Ratios comparing the levels of microorganisms in mussels were determined. These ratios changed in mussels collected at the different sites. They suggest that bacteriophages infecting B. fragilis and somatic coliphages have the lowest decay rates among the microorganisms studied, with the exception of Clostridium perfringens. On the contrary, concentrations of F-specific coliphages showed a greater rate of decay than the other bacteriophages at sites more distant from the focus of contamination. Additionally, levels of enteroviruses were studied in a number of samples, and in these samples, the B. fragilis bacteriophages clearly outnumbered the enteroviruses. The results of this study indicate that, under the environmental conditions studied, the fate of phages infecting B. fragilis released into the marine environment resembles that of human viruses more than any other microorganism examined. Images PMID:8074509

  2. Evaluation of Bacteroides fragilis GB-124 bacteriophages as novel human-associated faecal indicators in the United States

    EPA Science Inventory

    Phages infecting human-associated Bacteroides fragilis (GB-124 phages) have been employed in the European Union (EU) to identify human fecal pollution, but their utility for U.S. was unclear. Primary sewage effluent samples were collected seasonally from seven wastewater treatme...

  3. The effect of environmental conditions on expression of Bacteroides fragilis and Bacteroides thetaiotaomicron C10 protease genes

    PubMed Central

    2012-01-01

    Background Bacteroides fragilis and Bacteroides thetaiotaomicron are members of the normal human intestinal microbiota. However, both organisms are capable of causing opportunistic infections, during which the environmental conditions to which the bacteria are exposed change dramatically. To further explore their potential for contributing to infection, we have characterized the expression in B. thetaiotaomicron of four homologues of the gene encoding the C10 cysteine protease SpeB, a potent extracellular virulence factor produced by Streptococcus pyogenes. Results We identified a paralogous set of genes (btp genes) in the B. thetaiotaomicron genome, that were related to C10 protease genes we recently identified in B. fragilis. Similar to C10 proteases found in B. fragilis, three of the B. thetaiotaomicron homologues were transcriptionally coupled to genes encoding small proteins that are similar in structural architecture to Staphostatins, protease inhibitors associated with Staphopains in Staphylococcus aureus. The expression of genes for these C10 proteases in both B. fragilis and B. thetaiotaomicron was found to be regulated by environmental stimuli, in particular by exposure to oxygen, which may be important for their contribution to the development of opportunistic infections. Conclusions Genes encoding C10 proteases are increasingly identified in operons which also contain genes encoding proteins homologous to protease inhibitors. The Bacteroides C10 protease gene expression levels are responsive to different environmental stimuli suggesting they may have distinct roles in the bacterial-host interaction. PMID:22943521

  4. Acinetobacter variabilis sp. nov. (formerly DNA group 15 sensu Tjernberg & Ursing), isolated from humans and animals.

    PubMed

    Krizova, Lenka; McGinnis, Jana; Maixnerova, Martina; Nemec, Matej; Poirel, Laurent; Mingle, Lisa; Sedo, Ondrej; Wolfgang, William; Nemec, Alexandr

    2015-03-01

    We aimed to define the taxonomic status of 16 strains which were phenetically congruent with Acinetobacter DNA group 15 described by Tjernberg & Ursing in 1989. The strains were isolated from a variety of human and animal specimens in geographically distant places over the last three decades. Taxonomic analysis was based on an Acinetobacter-targeted, genus-wide approach that included the comparative sequence analysis of housekeeping, protein-coding genes, whole-cell profiling based on matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS), an array of in-house physiological and metabolic tests, and whole-genome comparative analysis. Based on analyses of the rpoB and gyrB genes, the 16 strains formed respective, strongly supported clusters clearly separated from the other species of the genus Acinetobacter. The distinctness of the group at the species level was indicated by average nucleotide identity values of ≤82 % between the whole genome sequences of two of the 16 strains (NIPH 2171(T) and NIPH 899) and those of the known species. In addition, the coherence of the group was also supported by MALDI-TOF MS. All 16 strains were non-haemolytic and non-gelatinase-producing, grown at 41 °C and utilized a rather limited number of carbon sources. Virtually every strain displayed a unique combination of metabolic and physiological features. We conclude that the 16 strains represent a distinct species of the genus Acinetobacter, for which the name Acinetobacter variabilis sp. nov. is proposed to reflect its marked phenotypic heterogeneity. The type strain is NIPH 2171(T) ( = CIP 110486(T) = CCUG 26390(T) = CCM 8555(T)). PMID:25510976

  5. Acinetobacter variabilis sp. nov. (formerly DNA group 15 sensu Tjernberg & Ursing), isolated from humans and animals

    PubMed Central

    Krizova, Lenka; McGinnis, Jana; Maixnerova, Martina; Nemec, Matej; Poirel, Laurent; Mingle, Lisa; Sedo, Ondrej; Wolfgang, William

    2015-01-01

    We aimed to define the taxonomic status of 16 strains which were phenetically congruent with Acinetobacter DNA group 15 described by Tjernberg & Ursing in 1989. The strains were isolated from a variety of human and animal specimens in geographically distant places over the last three decades. Taxonomic analysis was based on an Acinetobacter-targeted, genus-wide approach that included the comparative sequence analysis of housekeeping, protein-coding genes, whole-cell profiling based on matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS), an array of in-house physiological and metabolic tests, and whole-genome comparative analysis. Based on analyses of the rpoB and gyrB genes, the 16 strains formed respective, strongly supported clusters clearly separated from the other species of the genus Acinetobacter. The distinctness of the group at the species level was indicated by average nucleotide identity values of ≤82 % between the whole genome sequences of two of the 16 strains (NIPH 2171T and NIPH 899) and those of the known species. In addition, the coherence of the group was also supported by MALDI-TOF MS. All 16 strains were non-haemolytic and non-gelatinase-producing, grown at 41 °C and utilized a rather limited number of carbon sources. Virtually every strain displayed a unique combination of metabolic and physiological features. We conclude that the 16 strains represent a distinct species of the genus Acinetobacter, for which the name Acinetobacter variabilis sp. nov. is proposed to reflect its marked phenotypic heterogeneity. The type strain is NIPH 2171T ( = CIP 110486T = CCUG 26390T = CCM 8555T). PMID:25510976

  6. Domesticated horses differ in their behavioural and physiological responses to isolated and group housing.

    PubMed

    Yarnell, Kelly; Hall, Carol; Royle, Chris; Walker, Susan L

    2015-05-01

    The predominant housing system used for domestic horses is individual stabling; however, housing that limits social interaction and requires the horse to live in semi-isolation has been reported to be a concern for equine welfare. The aim of the current study was to compare behavioural and physiological responses of domestic horses in different types of housing design that provided varying levels of social contact. Horses (n = 16) were divided equally into four groups and exposed to each of four housing treatments for a period of five days per treatment in a randomized block design. The four housing treatments used were single housed no physical contact (SHNC), single housed semi-contact (SHSC), paired housed full contact (PHFC) and group housed full contact (GHFC). During each housing treatment, adrenal activity was recorded using non-invasive faecal corticosterone metabolite analysis (fGC). Thermal images of the eye were captured and eye temperature was assessed as a non-invasive measure of the stress response. Behavioural analysis of time budget was carried out and an ease of handling score was assigned to each horse in each treatment using video footage. SHNC horses had significantly higher (p = 0.01) concentrations of fGC and were significantly (p = 0.003) more difficult to handle compared to the other housing types. GHFC horses, although not significantly different, had numerically lower concentrations of fGC and were more compliant to handling when compared to all other housing treatments. Eye temperature was significantly (p = 0.0001) lower in the group housed treatment when compared to all other treatments. These results indicate that based on physiological and behavioural measures incorporating social contact into the housing design of domestic horses could improve the standard of domestic equine welfare. PMID:25725117

  7. Antibiotic Susceptibility Evaluation of Group A Streptococcus Isolated from Children with Pharyngitis: A Study from Iran

    PubMed Central

    2015-01-01

    Background The aim of this study was to evaluate the antibiotic susceptibility of Group A streptococcus (GAS) to antibiotics usually used in Iran for treatment of GAS pharyngitis in children. Materials and Methods From 2011 to 2013, children 3-15 years of age with acute tonsillopharyngitis who attended Mofid Children's Hospital clinics and emergency ward and did not meet the exclusion criteria were enrolled in a prospective study in a sequential manner. The isolates strains from throat culture were identified as GAS by colony morphology, gram staining, beta hemolysis on blood agar, sensitivity to bacitracin, a positive pyrrolidonyl aminopeptidase (PYR) test result, and the presence of Lancefield A antigen determined by agglutination test. Antimicrobial susceptibility was identified by both disk diffusion and broth dilution methods. Results From 200 children enrolled in this study, 59 (30%) cases were culture positive for GAS. All isolates were sensitive to penicillin G. The prevalence of erythromycin, azithromycin, and clarithromycin resistance by broth dilution method was 33.9%, 57.6%, and 33.9%, respectively. Surprisingly, 8.4% of GAS strains were resistant to rifampin. In this study, 13.5% and 32.2% of the strains were resistant to clindamycin and ofloxacin, respectively. Conclusion The high rate of resistance of GAS to some antibiotics in this study should warn physicians, especially in Iran, to use antibiotics restrictedly and logically to prevent the rising of resistance rates in future. It also seems that continuous local surveillance is necessary to achieve the best therapeutic option for GAS treatment. PMID:26788405

  8. Identification, genetic diversity and cereulide producing ability of Bacillus cereus group strains isolated from Beninese traditional fermented food condiments.

    PubMed

    Thorsen, Line; Azokpota, Paulin; Hansen, Bjarne Munk; Hounhouigan, D Joseph; Jakobsen, Mogens

    2010-08-15

    Bacillus cereus sensu lato is often detected in spontaneously fermented African foods but is rarely identified to species level. Only some of the B. cereus group species are reported to be pathogenic to humans and identification to species level is necessary to estimate the safety of these products. In the present study, a total of 19 Bacillus cereus group spp. isolated from afitin, iru and sonru, three spontaneously fermented African locust (Parkia biglobosa) bean based condiments produced in Benin, were investigated. The strains were isolated at 6, 12, 18, 24 and 48 h fermentation time. By using phenotypic and genotypic methods all of the isolates could be identified as B. cereus sensu stricto. The isolates were grouped according to their PM13 PCR (random amplification of polymorphic DNA PCR) fingerprint and formed two major clusters, one of which contained eight strains isolated from afitin (cluster 1). Highly similar PM13 profiles were obtained for seven of the isolates, one from afitin, one from iru and five from sonru (cluster 2). Four of the isolates, one from afitin and three from sonru, did not form any particular cluster. The PM13 profiles of cluster 2 isolates were identical to those which are specific to emetic toxin producers. Cereulide production of these isolates was confirmed by liquid chromatography mass spectrometry/mass spectrometry. This is the first report on cereulide producing B. cereus in African fermented foods. Occurrence of the opportunistic human pathogen B. cereus, which is able to produce emetic toxin in afitin, iru and sonru, could impose a health hazard. Interestingly, no reports on food poisoning from the consumption of the fermented condiments exist. PMID:20599285

  9. Activities of potential therapeutic and prophylactic antibiotics against blood culture isolates of viridans group streptococci from neutropenic patients receiving ciprofloxacin.

    PubMed Central

    McWhinney, P H; Patel, S; Whiley, R A; Hardie, J M; Gillespie, S H; Kibbler, C C

    1993-01-01

    All 47 sequential blood culture isolates of viridans group streptococci obtained from febrile neutropenic patients receiving quinolone prophylaxis were susceptible to vancomycin, teicoplanin, and imipenem. Resistance to benzylpenicillin (MIC for 50% of isolates [MIC50], 0.125 microgram/ml) and ceftazidime (MIC50, 4 micrograms/ml) was common. Most isolates were susceptible to amoxicillin, co-amoxiclav (amoxicillin-clavulanic acid at a 2:1 ratio by weight), azlocillin, clarithromycin, and erythromycin, with azithromycin showing comparable activity. The MIC90 of sparfloxacin was 1 microgram/ml; those for ciprofloxacin and ofloxacin were > 16 and 16 micrograms/ml, respectively. PMID:8285642

  10. The gut bacterial communities associated with lab-raised and field-collected ants of Camponotus fragilis (Formicidae: Formicinae).

    PubMed

    He, Hong; Wei, Cong; Wheeler, Diana E

    2014-09-01

    Camponotus is the second largest ant genus and known to harbor the primary endosymbiotic bacteria of the genus Blochmannia. However, little is known about the effect of diet and environment changes on the gut bacterial communities of these ants. We investigated the intestinal bacterial communities in the lab-raised and field-collected ants of Camponotus fragilis which is found in the southwestern United States and northern reaches of Mexico. We determined the difference of gut bacterial composition and distribution among the crop, midgut, and hindgut of the two types of colonies. Number of bacterial species varied with the methods of detection and the source of the ants. Lab-raised ants yielded 12 and 11 species using classical microbial culture methods and small-subunit rRNA genes (16S rRNAs) polymerase chain reaction-restriction fragment-length polymorphism analysis, respectively. Field-collected ants yielded just 4 and 1-3 species using the same methods. Most gut bacterial species from the lab-raised ants were unevenly distributed among the crop, midgut, and hindgut, and each section had its own dominant bacterial species. Acetobacter was the prominent bacteria group in crop, accounting for about 55 % of the crop clone library. Blochmannia was the dominant species in midgut, nearly reaching 90 % of the midgut clone library. Pseudomonas aeruginosa dominated the hindgut, accounting for over 98 % of the hindgut clone library. P. aeruginosa was the only species common to all three sections. A comparison between lab-raised and field-collected ants, and comparison with other species, shows that gut bacterial communities vary with local environment and diet. The bacterial species identified here were most likely commensals with little effect on their hosts or mild pathogens deleterious to colony health. PMID:24748441

  11. Highly frequent mutations in negative regulators of multiple virulence genes in group A streptococcal toxic shock syndrome isolates.

    PubMed

    Ikebe, Tadayoshi; Ato, Manabu; Matsumura, Takayuki; Hasegawa, Hideki; Sata, Tetsutaro; Kobayashi, Kazuo; Watanabe, Haruo

    2010-04-01

    Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of shock and multiorgan failure; it has a high mortality rate. Although a number of studies have attempted to determine the crucial factors behind the onset of STSS, the responsible genes in group A Streptococcus have not been clarified. We previously reported that mutations of csrS/csrR genes, a two-component negative regulator system for multiple virulence genes of Streptococcus pyogenes, are found among the isolates from STSS patients. In the present study, mutations of another negative regulator, rgg, were also found in clinical isolates of STSS patients. The rgg mutants from STSS clinical isolates enhanced lethality and impaired various organs in the mouse models, similar to the csrS mutants, and precluded their being killed by human neutrophils, mainly due to an overproduction of SLO. When we assessed the mutation frequency of csrS, csrR, and rgg genes among S. pyogenes isolates from STSS (164 isolates) and non-invasive infections (59 isolates), 57.3% of the STSS isolates had mutations of one or more genes among three genes, while isolates from patients with non-invasive disease had significantly fewer mutations in these genes (1.7%). The results of the present study suggest that mutations in the negative regulators csrS/csrR and rgg of S. pyogenes are crucial factors in the pathogenesis of STSS, as they lead to the overproduction of multiple virulence factors. PMID:20368967

  12. Highly Frequent Mutations in Negative Regulators of Multiple Virulence Genes in Group A Streptococcal Toxic Shock Syndrome Isolates

    PubMed Central

    Ikebe, Tadayoshi; Ato, Manabu; Matsumura, Takayuki; Hasegawa, Hideki; Sata, Tetsutaro; Kobayashi, Kazuo; Watanabe, Haruo

    2010-01-01

    Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of shock and multiorgan failure; it has a high mortality rate. Although a number of studies have attempted to determine the crucial factors behind the onset of STSS, the responsible genes in group A Streptococcus have not been clarified. We previously reported that mutations of csrS/csrR genes, a two-component negative regulator system for multiple virulence genes of Streptococcus pyogenes, are found among the isolates from STSS patients. In the present study, mutations of another negative regulator, rgg, were also found in clinical isolates of STSS patients. The rgg mutants from STSS clinical isolates enhanced lethality and impaired various organs in the mouse models, similar to the csrS mutants, and precluded their being killed by human neutrophils, mainly due to an overproduction of SLO. When we assessed the mutation frequency of csrS, csrR, and rgg genes among S. pyogenes isolates from STSS (164 isolates) and non-invasive infections (59 isolates), 57.3% of the STSS isolates had mutations of one or more genes among three genes, while isolates from patients with non-invasive disease had significantly fewer mutations in these genes (1.7%). The results of the present study suggest that mutations in the negative regulators csrS/csrR and rgg of S. pyogenes are crucial factors in the pathogenesis of STSS, as they lead to the overproduction of multiple virulence factors. PMID:20368967

  13. Increasing verbal interaction among elderly socially isolated mentally retarded adults: a group language training procedure.

    PubMed Central

    Kleitsch, E C; Whitman, T L; Santos, J

    1983-01-01

    The present study examined the effectiveness of a group language training procedure for directly increasing and generalizing the rate of verbal interaction among four elderly, socially isolated, moderately mentally retarded men. A withdrawal of treatment design was used to examine the effect of the procedure that used verbal prompts. behavioral rehearsal, and contingent social praise. Changes in behavior were examined in two generalization settings, one similar to the training environment (Generalization I) and the other arranged as part of the subjects' daily routine (Generalization II). Baseline data indicated no verbal interaction among the subjects. During treatment the training procedure increased the rate of subjects' verbal interactions not only in the training situation, but also in the two generalization settings. An analysis of the data obtained during the Generalization II situation indicated that subjects' verbal interaction increased not only among themselves, but with nonsubject peers present in this setting. Follow-up data showed that increases in rates of verbal interaction were maintained four months after the cessation of training. The implications of the results for program generalization and work with the language deficient individual is discussed. PMID:6885671

  14. Group-specific comparison of four lactobacilli isolated from human sources using differential blast analysis.

    PubMed

    Altermann, Eric; Klaenhammer, Todd R

    2011-08-01

    Lactic acid bacteria (LAB) have been used in fermentation processes for centuries. More recent applications including the use of LAB as probiotics have significantly increased industrial interest. Here we present a comparative genomic analysis of four completely sequenced Lactobacillus strains, isolated from the human gastrointestinal tract, versus 25 lactic acid bacterial genomes present in the public database at the time of analysis. Lactobacillus acidophilus NCFM, Lactobacillus johnsonii NCC533, Lactobacillus gasseri ATCC33323, and Lactobacillus plantarum WCFS1are all considered probiotic and widely used in industrial applications. Using Differential Blast Analysis (DBA), each genome was compared to the respective remaining three other Lactobacillus and 25 other LAB genomes. DBA highlighted strain-specific genes that were not represented in any other LAB used in this analysis and also identified group-specific genes shared within lactobacilli. Initial comparative analyses highlighted a significant number of genes involved in cell adhesion, stress responses, DNA repair and modification, and metabolic capabilities. Furthermore, the range of the recently identified potential autonomous units (PAUs) was broadened significantly, indicating the possibility of distinct families within this genetic element. Based on in silico results obtained for the model organism L. acidophilus NCFM, DBA proved to be a valuable tool to identify new key genetic regions for functional genomics and also suggested re-classification of previously annotated genes. PMID:21484153

  15. The yin yang of bacterial polysaccharides: Lessons learned from B. fragilis PSA

    PubMed Central

    Surana, Neeraj K.; Kasper, Dennis L.

    2011-01-01

    Summary Over the past several years, there have been remarkable advances in our understanding of how commensal organisms shape host immunity. Although the full cast of immunogenic bacteria and their immunomodulatory molecules remains to be elucidated, lessons learned from the interactions between bacterial zwitterionic polysaccharides (ZPSs) and the host immune system represent an integral step toward better understanding how the intestinal microbiota effect immunologic changes. Somewhat paradoxically, ZPSs, which are found in numerous commensal organisms, are able to elicit both proinflammatory and immunoregulatory responses; both of these outcomes involve fine-tuning the balance between T-helper 17 cells and interleukin-10–producing regulatory T cells. In this review, we discuss the immunomodulatory effects of the archetypal ZPS, Bacteroides fragilis PSA. In addition, we highlight some of the opportunities and challenges in applying these lessons in clinical settings. PMID:22168411

  16. Mutants of Group D1Salmonella Carrying the Somatic Antigen of Group A Organisms: Isolation and Serological Characterization

    PubMed Central

    Uchida, Takahiro; Matsumoto, Takeshi; Sasaki, Terukatsu

    1974-01-01

    O antigen mutants were obtained from Salmonella durban, a group D1 organism, by treatment with N-methyl-N′-nitro-N-nitrosoguanidine. Serological studies demonstrated that the mutants lost the O-9 antigen factor of the parent organism but acquired the O-2 factor specific to group A Salmonella. Lipopolysaccharides of the mutant strains contained paratose which determines the specificity of O-2 factor. Tyvelose, present in the wild-type lipopolysaccharide, was not found in the mutants. H antigens and other biological characteristics of the mutant strains were the same as those of the wild-type organism. The present finding implies that group A Salmonella species might be derived from group D1 organisms. PMID:4587616

  17. Genetic variability of the coat protein sequence of pea seed-borne mosaic virus isolates and the current relationship between phylogenetic placement and resistance groups.

    PubMed

    Wylie, S J; Coutts, B A; Jones, R A C

    2011-07-01

    Nucleotide sequences of complete or partial coat protein (CP) genes were determined for 11 isolates of pea seed-borne mosaic virus (PSbMV) from Australia and one from China, and compared with known sequences of 20 other isolates. On phylogenetic analysis, the isolates from Australia and China grouped into 2 of 3 clades. Clade A contained three sub-clades (Ai, Aii and Aiii), Australian isolates were in Ai or Aiii, and the Chinese isolate in Aii. Clade A contained isolates in pathotypes P-1, P-2 and U-2; clade B, one isolate in P-2; and clade C, only isolates in P-4. PMID:21519930

  18. Nasal Histopathology and Intracage Ammonia Levels in Female Groups and Breeding Mice Housed in Static Isolation Cages

    PubMed Central

    Mexas, Angela M; Brice, Angela K; Caro, Adam C; Hillanbrand, Troy S

    2015-01-01

    Many factors influence ammonia levels in rodent cages, and high intracage ammonia has been associated with specific types of abnormal nasal pathology in mice. The use of autoclaved corncob bedding and the maintenance of low room humidity reduce the accumulation of ammonia in mouse cages. However, there are no engineering standards that define the limits of ammonia exposure for mice housed in static isolation cages. Regulatory guidance indicates that solid bottom cages must be sanitized at least weekly and that cage components in direct contact with animals must be sanitized at least every 2 wk. Common practice is to replace the bottoms and bedding of static isolation cages once weekly. To determine whether changing static isolation cages once weekly is an appropriate performance standard for mice, we prospectively evaluated the relationship between ammonia levels, nasal histopathology, and housing densities in various grouping strategies of mice housed in static isolation cages. Here, we report that the average nasal pathology score per cage and intracage ammonia levels were correlated, but nasal pathology scores did not differ among mice housed in breeding pairs, breeding trios, or female groups. In light of ammonia levels and histopathology scores as performance standards, these results suggest that a weekly cage-change frequency for static isolation cages does not result in adverse effects. Our results provide evidence to support current practices in the use of static isolation cages for housing laboratory mice in modern vivaria. PMID:26424245

  19. Preferential Acquisition and Activation of Plasminogen Glycoform II by PAM Positive Group A Streptococcal Isolates.

    PubMed

    De Oliveira, David M P; Law, Ruby H P; Ly, Diane; Cook, Simon M; Quek, Adam J; McArthur, Jason D; Whisstock, James C; Sanderson-Smith, Martina L

    2015-06-30

    Plasminogen (Plg) circulates in the host as two predominant glycoforms. Glycoform I Plg (GI-Plg) contains glycosylation sites at Asn289 and Thr346, whereas glycoform II Plg (GII-Plg) is exclusively glycosylated at Thr346. Surface plasmon resonance experiments demonstrated that Plg binding group A streptococcal M protein (PAM) exhibits comparative equal affinity for GI- and GII-Plg in the "closed" conformation (for GII-Plg, KD = 27.4 nM; for GI-Plg, KD = 37.0 nM). When Plg was in the "open" conformation, PAM exhibited an 11-fold increase in affinity for GII-Plg (KD = 2.8 nM) compared with that for GI-Plg (KD = 33.2 nM). The interaction of PAM with Plg is believed to be mediated by lysine binding sites within kringle (KR) 2 of Plg. PAM-GI-Plg interactions were fully inhibited with 100 mM lysine analogue ε-aminocaproic acid (εACA), whereas PAM-GII-Plg interactions were shown to be weakened but not inhibited in the presence of 400 mM εACA. In contrast, binding to the KR1-3 domains of GII-Plg (angiostatin) by PAM was completely inhibited in the presence 5 mM εACA. Along with PAM, emm pattern D GAS isolates express a phenotypically distinct SK variant (type 2b SK) that requires Plg ligands such as PAM to activate Plg. Type 2b SK was able to generate an active site and activate GII-Plg at a rate significantly higher than that of GI-Plg when bound to PAM. Taken together, these data suggest that GAS selectively recruits and activates GII-Plg. Furthermore, we propose that the interaction between PAM and Plg may be partially mediated by a secondary binding site outside of KR2, affected by glycosylation at Asn289. PMID:26029848

  20. Summary of presentation for research on social structure, agreement, and conflict in groups in extreme and isolated environments

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Despite a vast amount of research, little is known concerning the effect of group structure, and individuals' understanding of that structure, on conflict in Antarctic groups. The overall objective of the research discussed is to determine the interrelationships of group structure, social cognition, and group function and conflict in isolated and extreme environments. In the two decades following WWII, a large body of research focused on the physiological, psychological, and social psychological factors affecting the functioning of individuals and groups in a variety of extreme and isolated environments in both the Arctic and Antarctic. There are two primary reasons for further research of this type. First, Antarctic polar stations are considered to be natural laboratories for the social and behavioral sciences and provide an opportunity to address certain theoretical and empirical questions concerned with agreement and conflict in social groups in general and group behavior in extreme, isolated environments in particular. Recent advances in the analysis of social networks and intracultural variation have improved the methods and have shifted the theoretical questions. The research is motivated by three classes of questions: (1) What are the characteristics of the social relations among individuals working and living together in extreme and isolated environments?; (2) What do individuals understand about their group, how does that understanding develop, and how is it socially distributed?; and (3) What is the relationship between that understanding and the functioning of the social group? Answers to these questions are important if we are to advance our knowledge of how individuals and groups adapt to extreme environments. Second, although Antarctic winter-over candidates may be evaluated as qualified on the basis of individual characteristics, they may fail to adapt because of certain characteristics of the social group. Consequently, the ability of winter-over-groups

  1. Silting up and development of anoxic conditions enhanced by high abundance of the geoengineer species Ophiothrix fragilis

    NASA Astrophysics Data System (ADS)

    Murat, A.; Méar, Y.; Poizot, E.; Dauvin, J. C.; Beryouni, K.

    2016-04-01

    In the English Channel, the brittle-star Ophiothrix fragilis is a common epifaunal species typically found on pebbles in habitats with strong tidal currents. This species forms dense aggregations on the seafloor, supporting populations that can reach up to 7500 ind m-2 in the eastern part of the Baie de Seine, offshore from Antifer harbour. Here, O. fragilis occurs in an area with unexpected amounts of fine-grained sediment. Some of these mud deposits are made up of unusually compact black muds, an indication of the development of anoxic conditions in surficial sediments. To highlight a potential link between silting up and dense O. fragilis populations, and identify the interactions between environmental conditions and the population dynamics of this species, we analyse the data from three surveys corresponding to exceptional situations: (1) just after a Seine flood; (2) just after a storm and (3) after a period of ten months without any flood or storm. Four parameters are taken into account: number of brittle stars per 0.25 m2, Fine Fraction percentage, Total Organic Carbon and Total Sulphur. The main environmental forcings appear to be Seine river inflow, regional circulation dependent on tidal currents and the occurrence of storms. O. fragilis is able to geoengineer its environment in various ways and at different rates. Silting up is enhanced by increasing abundance of O. fragilis and takes place at a very fast rate. As a result, floods and storms reflecting instantaneous events give rise to a steady-state situation established between the abundance of this species and the fine fraction percentage. Anoxic conditions are dependent on the degradation of organic matter and require more time to be established. After many months in the absence of any disturbing events, anoxic conditions are developed in non-compacted muddy sediments (stability situation) and represent the normal surficial situation when the sediment becomes compacted (compact black muds). The

  2. Isolation of Flavimonas oryzihabitans (CDC group Ve-2) from catheter-induced bacteremia in an immunocompromised patient.

    PubMed

    Mutters, R; Köppler, H; Krause, T

    1990-12-01

    Bacteria of the newly proposed genus and combination Flavimonas oryzihabitans, previously known as CDC group Ve-2 or Pseudomonas oryzihabitans, are uncommon pathogens. We report here the first isolation of the organism in Germany from a case of bacteremia and describe the phenotypic characteristics of the strain. PMID:2091948

  3. Antibiotic susceptibilities, streptococcal pyrogenic exotoxin gene profiles among clinical isolates of group C or G Streptococcus dysgalactiae subsp. equisimilis & of group G S. anginosus group at a tertiary care centre

    PubMed Central

    Behera, Bijayini; Mathur, Purva; Bhardwaj, Nidhi; Jain, Neetu; Misra, M. C.; Kapil, Arti; Singh, Sarman

    2014-01-01

    Background & objectives: Group C and group G streptococci (together GCGS) are often regarded as commensal bacteria and their role in streptococcal disease burden is under-recognized. While reports of recovery of GCGS from normally sterile body sites are increasing, their resistance to macrolides, fluoroquinolone further warrants all invasive β haemolytic streptococci to be identified to the species level and accurately tested for antimicrobial susceptibility. This study was aimed to determine the prevalence, clinical profile, antimicrobial susceptibility and streptococcal pyrogenic exotoxin gene profile (speA, speB, speC, speF, smeZ, speI, speM, speG, speH and ssa) of GCGS obtained over a period of two years at a tertiary care centre from north India. Methods: The clinical samples were processed as per standard microbiological techniques. β-haemolytic streptococci (BHS) were characterized and grouped. Antimicrobial susceptibility of GCGS was performed using disk diffusion method. All GCGS were characterized for the presence of streptococcal pyrogenic exotoxins (spe) and spe genes were amplified by PCR method. Results: GCGS (23 GGS, 2GCS) comprised 16 per cent of β haemolytic streptococci (25/142 βHS, 16%) isolated over the study period. Of the 25 GCGS, 22 (88%) were recovered from pus, two (8%) from respiratory tract, whereas one isolate was recovered from blood of a fatal case of septicaemia. Of the total 23 GGS isolates, 18 (78%) were identified as Streptococcus dysgalactiae subsp equisimilis (SDSE, large-colony phenotype), five (21%) were Streptococcus anginosus group (SAG, small-colony phenotype). The two GCS were identified as SDSE. All GCGS isolates were susceptible to penicillin, vancomycin, and linezolid. Tetracycline resistance was noted in 50 per cent of SDSE isolates. The rates of macrolide and fluoroquinolone resistance in SDSE were low. Twelve of the 20 SDSE isolates were positive for one or more spe genes, with five of the SDSE isolates

  4. Assessing Site-Isolation of Amine Groups on Aminopropyl-Functionalized SBA-15 Materials via Spectroscopic and Reactivity Probes

    SciTech Connect

    Hicks, Jason C; Dabestani, Reza T; Buchanan III, A C; Jones, Christopher W

    2008-01-01

    The average degree of separation and the accessibility of aminopropyl groups on SBA-15 silica materials prepared using different silane grafting approaches are compared. Three specific synthetic approaches are used: (1) the traditional grafting of 3-aminopropyltrimethoxysilane in toluene, (2) a protection/deprotection method using benzyl- or trityl-spacer groups, and (3) a cooperative dilution method where 3-aminopropyltrimethoxysilane and methyltrimethoxysilane are co-condensed on the silica surface as a silane mixture. The site-isolation and accessibility of the amine groups are probed via three methods: (a) evaluation of pyrene groups adsorbed onto the solids using fluorescence spectroscopy, (b) the reactions of chlorodimethyl(2,3,4,5-tetramethyl-2,4-cyclopentadien-1-yl)silane (Cp'Si(Me){sub 2}Cl) and chloro(cyclopenta-2,4-dienyl)dimethylsilane (CpSi(Me){sub 2}Cl) with the tethered amine sites, and (c) comparison of the reactivity of zirconium constrained-geometry-inspired catalysts (CGCs) prepared using the Cp'Si(Me){sub 2}-modified aminosilicas in the catalytic polymerization of ethylene to produce poly(ethylene). The spectroscopic probe of site-isolation suggests that both the protection/deprotection method and the cooperative dilution method yield similarly isolated amine sites that are markedly more isolated than sites on traditional aminosilica. In contrast, both reactivity probes show that the protection/deprotection strategy leads to more uniformly accessible amine groups. It is proposed that the reactivity probes are more sensitive tests for accessibility and site-isolation in this case.

  5. [Investigation of the serotype distribution, biofilm production and antibiotic susceptibilities of group B streptococci isolated from urinary samples].

    PubMed

    Baba, Sevinç; Aydın, Mustafa Derya

    2016-07-01

    Streptococcus agalactiae (Group B streptococcus, GBS), a member of normal flora of human gastrointestinal and genitourinary systems, is a leading cause of sepsis, meningitis, and pneumonia particularly in newborn. GBS can also cause severe infections in pregnant women and adults with underlying disease, as well as mild diseases, such as urinary tract infections (UTIs). GBS strains exhibit 10 different serotypes, and the identification of serotype distribution is important epidemiologically. The role of biofilm production is one of the virulence factors that has been discussed in the pathogenesis of GBS infections. Although resistance to penicillin and ampicillin has not been documented in GBS, different rates of resistance has been reported for the alternative antibiotics to penicillin. The aim of this study was to investigate the serotype distribution, the ability of biofilm formation and the antibiotic susceptibilities of S.agalactiae strains isolated from urine cultures. A total of 60 strains were included in the study, 40 of them were isolated from patients (38 female 2 male; mean age: 36.7 years) with urinary tract complaints whose cultures yielded single type of colonies in the number of ≥ 50.000 cfu/ml, whereas 20 of them were isolated from patients (19 female 1 male; mean age: 37.2 years) without urinary tract complaints whose cultures yielded mixed colonies in the number of ≤ 20.000 cfu/ml. Chromogenic media were used for the isolation and the isolates were identified by conventional methods. The isolates were then serotyped by latex agglutination method and their antibiotic susceptibilities were determined by disk diffusion method recommended by CLSI documents. Biofilm formation of the strains were investigated by microplate and Congo red agar (CRA) methods. In our study, the most frequently detected serotypes were V (n= 18; 30%) and II (n= 14; 23.3%), followed by serotype Ia (n= 10; 16.7%), III (n= 9; 15%), Ib (n= 3; 5%), VI (n= 1; 1.7%) and VII (n

  6. In vitro effects of sulbactam combinations with different antibiotic groups against clinical Acinetobacter baumannii isolates.

    PubMed

    Deveci, Aydin; Coban, Ahmet Yilmaz; Acicbe, Ozlem; Tanyel, Esra; Yaman, Gorkem; Durupinar, Belma

    2012-10-01

    Treatment of multidrug resistant (MDR) Acinetobacter baumannii infections causes some problems as a result of possessing various antibacterial resistance mechanisms against available antibiotics. Combination of antibiotics, acting by different mechanisms, is used for the treatment of MDR bacterial infections. It is an important factor to determine synergy or antagonism between agents in the combination for the constitution of effective therapy. The study aimed to determine In vitro interactions interpreted according to calculated fractional inhibitory concentration (FIC) index between sulbactam and ceftazidime, ceftriaxone, cefepime, ciprofloxacin, gentamicin, meropenem, tigecycline, and colistin. Ten clinical isolates of A. baumannii were tested for determination of synergistic effects of sulbactam with different antimicrobial combinations. Minimal inhibitory concentration (MIC) values of both sulbactam and combined antibiotics decreased 2- to 128-fold. Synergy and partial synergy were determined in combination of sulbactam with ceftazidime and gentamicin (FIC index: ≤ 0.5 or >0.5 to <1) and MIC values of both ceftazidime and gentamicin for five isolates fell down below the susceptibility break point. Similarly, MIC value of ciprofloxacin for six ciprofloxacin resistant isolates was determined as below the susceptibility break point in combination. However, all isolates were susceptible to colistin and tigecycline, MIC values of both were decreased in combination with sulbactam. Although synergistic and partial synergistic effects were observed in the combination of sulbactam and ceftriaxone, all isolates remained resistant to ceftriaxone. The effect of cefepime-sulbactam combination was synergy in five, partial synergy in one and indifferent in four isolates. Meropenem and sulbactam showed a partial synergistic effect (FIC index: >0.5 to <1) in three, an additive effect (FIC index: 1) in one and an indifferent effect (FIC index: >1-2) in six isolates

  7. Classification of Colletotrichum coccodes isolates into vegetative compatibility groups using infrared attenuated total reflectance spectroscopy and multivariate analysis.

    PubMed

    Salman, A; Shufan, E; Tsror, L; Moreh, R; Mordechai, S; Huleihel, M

    2014-07-01

    In this study the potential of infrared (IR) spectroscopy for the classification of Colletotrichum coccodes (C. coccodes) isolates into vegetative compatibility groups (VCGs) was evaluated. Isolates which belong to the same VCG may have similar pathological and physiological traits that differ from those that are not assigned to the same VCG. Early classification of isolates into VCGs is of a great importance for a better understanding of the epidemiology of the disease and improves its control. The main goal of the present study was to classify 14 isolates of C. coccodes into VCGs and differentiate between them, based on their IR absorption spectra as obtained by the FTIR-ATR sampling technique. Advanced statistical and mathematical methods, including Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA), were applied to the spectra after manipulation. The results show that it is possible to assign the isolates into VCGs with more than 90% success based on the wavenumber low region (1800-800 cm(-1)) and using 15 PCs. However, on the isolate level, the best differentiation results were obtained using PCA (15 PCs) and LDA for the combined regions (2990-2800 cm(-1), 1800-800 cm(-1)), with identification success rates of 87.2%. PMID:24582779

  8. Genetic polymorphism of Malassezia furfur isolates from Han and Tibetan ethnic groups in China using DNA fingerprinting.

    PubMed

    Zhang, Hao; Zhang, Ruifeng; Ran, Yuping; Dai, Yaling; Lu, Yao; Wang, Peng

    2010-12-01

    Reported isolation rates of Malassezia yeast from human skin show geographic variations. In China, the populations of the Han (1,182.95 million) and Tibetan (5.41 million) ethnic groups are distributed over 9.6 and 3.27 million square kilometers respectively, making biodiversity research feasible and convenient. Malassezia furfur clinical strains (n = 29) isolated from different individuals, with or without associated dermatoses, of these two ethnic groups (15 Han and 12 Tibetan) were identified and analyzed with DNA fingerprinting using single primers specific to minisatellites. Using the Bionumerics software, we found that almost all M. furfur clinical isolates and type strains formed five distinct group clusters according to their associated skin diseases and the ethnic groups of the patients. These findings are the first to focus on the genetic diversity and relatedness of M. furfur in the Tibetan and Han ethnic groups in China and reveal genetic variation associated with related diseases, host ethnicity and geographic origin. PMID:20507265

  9. Genetic and antigenic typing of border disease virus (BDV) isolates from Italy reveals the existence of a novel BDV group.

    PubMed

    Giammarioli, Monica; La Rocca, Severina Anna; Steinbach, Falko; Casciari, Cristina; De Mia, Gian Mario

    2011-01-27

    Border disease virus belongs to the Pestivirus genus, within the family Flaviviridae. Genetic analysis of pestiviruses isolated from sheep in continental Europe have led to the proposal that BDV isolates are segregated into at least seven clusters. In 2005 the molecular analysis of an Italian caprine BDV strain provided evidence for the presence of an atypical pestivirus, which may represent the first member of a putative novel pestivirus sub-group. To further build on this study, ovine pestivirus strains were isolated from small ruminant flocks and characterized both genetically and antigenically. A defined section of the 5'UTR and the complete N(pro) coding region were amplified and used for phylogenetic analysis. This revealed that these pestiviruses belong to the BDV species but differed significantly from all previously described ovine pestiviruses providing evidence for the presence of a novel genetic group. Four of the five isolates were also typed antigenically with a panel of pestivirus specific mAbs directed against NS2/3, E(rns) and E2 proteins. The four isolates reacted with a distinct set of mAbs, in particular against the BDV-E2 and the BDV-E(rns) epitopes. The isolates were greatly reactive for E(rns) and NS2/3 mAbs, which are otherwise typical for BVDV-2, and one E2 mAb that typically stains BVDV-1. The Italian pestiviruses analysed in this study, according to their antigenic and genetic properties, clustered into a novel phylogenetic group, that we propose to term BDV-7. PMID:20656426

  10. Nest-Gallery Development and Caste Composition of Isolated Foraging Groups of the Drywood Termite, Incisitermes minor (Isoptera: Kalotermitidae).

    PubMed

    Himmi, S Khoirul; Yoshimura, Tsuyoshi; Yanase, Yoshiyuki; Oya, Masao; Torigoe, Toshiyuki; Akada, Masanori; Imadzu, Setsuo

    2016-01-01

    An X-ray computed-tomographic examination of nest-gallery development from timbers naturally infested by foraging groups of Incisitermes minor colonies was conducted. This study documents the colonization process of I. minor to new timbers and how the isolated groups maintain their nest-gallery system. The results suggested that development of a nest-gallery within a suitable wood item is not random, but shows selection for softer substrate and other adaptations to the different timber environments. Stigmergic coordinations were expressed in dynamic changes of the nest-gallery system; indicated by fortification behavior in sealing and re-opening a tunnel approaching the outer edge of the timber, and accumulating fecal pellets in particular chambers located beneath the timber surface. The study also examines the caste composition of isolated groups to discover how I. minor sustains colonies with and without primary reproductives. PMID:27455332

  11. Allocation of Klebsiella pneumoniae Bloodstream Isolates into Four Distinct Groups by ompK36 Typing in a Taiwanese University Hospital

    PubMed Central

    Zheng, Po-Xing; Wang, Ming-Cheng; Tsai, Shu-Huei; Wang, Li-Rong; Wu, Jiunn-Jong

    2015-01-01

    The OmpK36 porin plays a role in carbapenem resistance and may contribute to bacterial virulence in Klebsiella pneumoniae. This study aimed to investigate the characteristics of different groups of K. pneumoniae separated by ompK36 typing. Among 226 nonduplicate K. pneumoniae bloodstream isolates collected at a Taiwanese hospital in 2011, four ompK36 types, designated types A, B, C, and D, were identified by PCR in 61, 28, 100, and 36 isolates, respectively; 1 isolate was untypeable. Statistical analysis showed significantly higher rates of antimicrobial resistance (all tested antibiotics except meropenem), extended-spectrum β-lactamases or DHA-1 (47.5% together), Qnr-type quinolone resistance determinants (50.8%), and IncFIIA-type plasmids (49.2%) in group A than in others. Seventeen isolates were identified as belonging to 3 international high-risk clones (4 sequence type 11 [ST11], 10 ST15, and 3 ST147 isolates); all isolates but 1 ST15 isolate were classified in group A. The significant characteristics of group C were hypermucoviscosity (62.0%) and a higher virulence gene content. This group included all serotype K1 (n = 30), K2 (n = 25), and K5 (n = 3) isolates, 6 of 7 K57 isolates, all isolates of major clones associated with pyogenic liver abscesses (29 ST23, 11 ST65, 5 ST86, 7 ST373, and 1 ST375 isolates), and 16 (94.1%) of 17 isolates causing bacteremic liver abscesses. Twelve (42.9%) of the group B isolates were responsible for bacteremic biliary tract infections. Group D was predominant (83.3%) among 12 K20 isolates. This study suggests that most clinical K. pneumoniae isolates can be allocated into four groups with distinct characteristics based on ompK36 types. PMID:26224840

  12. Mutation of the Zinc-Binding Metalloprotease Motif Affects Bacteroides fragilis Toxin Activity but Does Not Affect Propeptide Processing

    PubMed Central

    Franco, Augusto A.; Buckwold, Simy L.; Shin, Jai W.; Ascon, Miguel; Sears, Cynthia L.

    2005-01-01

    To evaluate the role of the zinc-binding metalloprotease in Bacteroides fragilis toxin (BFT) processing and activity, the zinc-binding consensus sequences (H348, E349, H352, G355, H358, and M366) were mutated by site-directed-mutagenesis. Our results indicated that single point mutations in the zinc-binding metalloprotease motif do not affect BFT processing but do reduce or eliminate BFT biologic activity in vitro. PMID:16041055

  13. Screening for probiotic properties of strains isolated from feces of various human groups.

    PubMed

    Sathyabama, Sathyaseelan; Vijayabharathi, Rajendran; Bruntha Devi, Palanisamy; Ranjith Kumar, Manohar; Priyadarisini, Venkatesan Brindha

    2012-08-01

    The present study searched for potential probiotic strains from various human fecal samples. A total of 67 aerobic and 38 anaerobic strains were isolated from 5 different categories of human feces. Systematic procedures were used to evaluate the probiotic properties of the isolated strains. These showed about 75-97% survivability in acidic and bile salt environments. Adhesion to intestinal cell line Caco-2 was also high. The isolates exhibited hydrophobic properties in hexadecane. The culture supernatants of these strains showed antagonistic effects against pathogens. The isolates were resistant to a simulated gastrointestinal environment in vitro. Of the 4 best isolates, MAbB4 (Staphylococcus succinus) and FIdM3 (Enterococcus fecium), were promising candidates for a potential probiotic. S. succinus was found to be a probiotic strain, which is the second such species reported to date in this particular genus. A substantial zone of inhibition was found against Salmonella spp., which adds further support to the suggestion that the probiotic strain could help prevent intestinal infection. This study suggested that the human flora itself is a potential source of probiotics. PMID:22923108

  14. Analysis of the outer membrane proteome and secretome of Bacteroides fragilis reveals a multiplicity of secretion mechanisms.

    PubMed

    Wilson, Marlena M; Anderson, D Eric; Bernstein, Harris D

    2015-01-01

    Bacteroides fragilis is a widely distributed member of the human gut microbiome and an opportunistic pathogen. Cell surface molecules produced by this organism likely play important roles in colonization, communication with other microbes, and pathogenicity, but the protein composition of the outer membrane (OM) and the mechanisms used to transport polypeptides into the extracellular space are poorly characterized. Here we used LC-MS/MS to analyze the OM proteome and secretome of B. fragilis NCTC 9343 grown under laboratory conditions. Of the 229 OM proteins that we identified, 108 are predicted to be lipoproteins, and 61 are predicted to be TonB-dependent transporters. Based on their proximity to genes encoding TonB-dependent transporters, many of the lipoprotein genes likely encode proteins involved in nutrient or small molecule uptake. Interestingly, protease accessibility and biotinylation experiments indicated that an unusually large fraction of the lipoproteins are cell-surface exposed. We also identified three proteins that are members of a novel family of autotransporters, multiple potential type I protein secretion systems, and proteins that appear to be components of a type VI secretion apparatus. The secretome consisted of lipoproteins and other proteins that might be substrates of the putative type I or type VI secretion systems. Our proteomic studies show that B. fragilis differs considerably from well-studied Gram-negative bacteria such as Escherichia coli in both the spectrum of OM proteins that it produces and the range of secretion strategies that it utilizes. PMID:25658944

  15. Antibacterial activity of diketopiperazines isolated from a marine fungus using t-butoxycarbonyl group as a simple tool for purification.

    PubMed

    El-Gendy, Bahaa El-Dien M; Rateb, Mostafa E

    2015-08-15

    Nine diketopiperazines were characterized from the culture of marine fungal isolate MR2012 which based on DNA amplification and sequencing of the fungal internal transcribed spacer (ITS) region was identified as Aspergillus fumigatus. The isolated fungal metabolites 4-12 were unambiguously identified as a series of simple and re-arranged diketopiperazines by analysis of spectroscopic data. t-Butoxycarbonyl group (BOC) derivatization was used to separate the intractable mixture of 4 and 5. When all compounds were evaluated for antimicrobial activity against gram positive bacteria, the isolated metabolites showed moderate to weak effects, while the semisynthetic derivatives 4a and 5a displayed strong activity comparable to the positive control, tetracycline against gram positive bacteria. PMID:26099531

  16. Outbreeding lethality between toxic Group I and nontoxic Group III Alexandrium tamarense spp. isolates: Predominance of heterotypic encystment and implications for mating interactions and biogeography

    NASA Astrophysics Data System (ADS)

    Brosnahan, Michael L.; Kulis, David M.; Solow, Andrew R.; Erdner, Deana L.; Percy, Linda; Lewis, Jane; Anderson, Donald M.

    2010-02-01

    We report the zygotic encystment of geographically dispersed isolates in the dinoflagellate species complex Alexandrium tamarense, in particular, successful mating of toxic Group I and nontoxic Group III isolates. However, hypnozygotes produced in Group I/III co-cultures complete no more than three divisions after germinating. Previous reports have suggested a mate recognition mechanism whereby hypnozygotes produced in co-cultures could arise from either homotypic (inbred) or heterotypic (outbred) gamete pairs. To determine the extent to which each occurs, a nested PCR assay was developed to determine parentage of individual hypnozygotes. The vast majority of hypnozygotes from pairwise Group I/III co-cultures were outbred, so that inviability was a result of hybridization, not inbreeding. These findings support the assertion that complete speciation underlies the phylogenetic structure of the Alexandrium tamarense species complex. Additionally, the ribosomal DNA (rDNA) copy numbers of both hybrid and single ribotype hypnozygotes were reduced substantially from those of haploid motile cells. The destruction of rDNA loci may be crucial for the successful mating of genetically distant conjugants and appears integral to the process of encystment. The inviability of Group I/III hybrids is important for public health because the presence of hybrid cysts may indicate ongoing displacement of a nontoxic population by a toxic one (or vice versa). Hybrid inviability also suggests a bloom control strategy whereby persistent, toxic Group I blooms could be mitigated by introduction of nontoxic Group III cells. The potential for hybridization in nature was investigated by applying the nested PCR assay to hypnozygotes from Belfast Lough, Northern Ireland, a region where Group I and III populations co-occur. Two hybrid cysts were identified in 14 successful assays, demonstrating that Group I and III populations do interbreed in that region. However, an analysis of mating data

  17. Outbreeding lethality between toxic Group I and nontoxic Group III Alexandrium tamarense spp. isolates: Predominance of heterotypic encystment and implications for mating interactions and biogeography

    PubMed Central

    Brosnahan, Michael L.; Kulis, David M.; Solow, Andrew R.; Erdner, Deana L.; Percy, Linda; Lewis, Jane; Anderson, Donald M.

    2013-01-01

    We report the zygotic encystment of geographically dispersed isolates in the dinoflagellate species complex Alexandrium tamarense, in particular, successful mating of toxic Group I and nontoxic Group III isolates. However, hypnozygotes produced in Group I/III co-cultures complete no more than three divisions after germinating. Previous reports have suggested a mate recognition mechanism whereby hypnozygotes produced in co-cultures could arise from either homotypic (inbred) or heterotypic (outbred) gamete pairs. To determine the extent to which each occurs, a nested PCR assay was developed to determine parentage of individual hypnozygotes. The vast majority of hypnozygotes from pairwise Group I/III co-cultures were outbred, so that inviability was a result of hybridization, not inbreeding. These findings support the assertion that complete speciation underlies the phylogenetic structure of the Alexandrium tamarense species complex. Additionally, the ribosomal DNA (rDNA) copy numbers of both hybrid and single ribotype hypnozygotes were reduced substantially from those of haploid motile cells. The destruction of rDNA loci may be crucial for the successful mating of genetically distant conjugants and appears integral to the process of encystment. The inviability of Group I/III hybrids is important for public health because the presence of hybrid cysts may indicate ongoing displacement of a nontoxic population by a toxic one (or vice versa). Hybrid inviability also suggests a bloom control strategy whereby persistent, toxic Group I blooms could be mitigated by introduction of nontoxic Group III cells. The potential for hybridization in nature was investigated by applying the nested PCR assay to hypnozygotes from Belfast Lough, Northern Ireland, a region where Group I and III populations co-occur. Two hybrid cysts were identified in 14 successful assays, demonstrating that Group I and III populations do interbreed in that region. However, an analysis of mating data

  18. Enterotoxin production in relation to taxonomic grouping and source of isolation of Aeromonas species.

    PubMed

    Turnbull, P C; Lee, J V; Miliotis, M D; Van de Walle, S; Koornhof, H J; Jeffery, L; Bryant, T N

    1984-02-01

    A total of 19 of 20 (95%) strains of Aeromonas hydrophila biovar hydrophila and 16 of 17 (94%) strains of Aeromonas sobria isolated from a variety of clinical and environmental sources were found to be enterotoxin positive. Only 2 of 18 (11%) A. hydrophila biovar anaerogenes and 2 of 13 (15%) unidentified Aeromonas strains from a similar variety of sources produced enterotoxin. No association was apparent between the source of isolation, in particular diarrheal stools, and enterotoxigenicity; 41% of the isolates from diarrheal stools were enterotoxin negative. A strong correlation was noted between ability to produce enterotoxin and positive results in six characters: lysine decarboxylase and Voges-Proskauer reactions, production of gas from glucose, gluconate oxidation, xanthine hydrolysis, and hemolysis of human erythrocytes. In the majority of cases (35 of 39 strains), enterotoxigenicity was detected using cell-free filtrates of brain heart infusion broth cultures grown at 36 degrees C for 15; however, the other four positive isolates were detected after growth in the same broth at 30 degrees C or in Casamino Acids-yeast extract broth at 30 or 37 degrees C. It is recommended that for enterotoxin tests, strains should be grown in both media at both temperatures. The infant mouse test was found to be a simple and reliable method for detection of the enterotoxin. The toxin proved to be heat labile and not neutralized by cholera antitoxin. PMID:6699147

  19. A Simple, Semiselective Medium for Anaerobic Isolation of Anginosus Group Streptococci from Patients with Chronic Lung Disease

    PubMed Central

    Waite, Richard D.; Wareham, David W.; Gardiner, Samuel

    2012-01-01

    The anaerobic isolation of anginosus group streptococci (AGS) from respiratory specimens containing diverse microbiota using a semiselective blood agar medium incorporating nalidixic acid and sulfamethazine (NAS) is described. AGS were detected in 60% of tested sputa from patients with cystic fibrosis, chronic obstructive pulmonary disease, and bronchiectasis. This demonstrates NAS to be a diagnostic tool for detecting AGS within the complex microbial communities associated with chronic lung disorders. PMID:22238446

  20. Phylogenetic groups, extended-spectrum β-lactamases and metallo-β-lactamase in Escherichia coli isolated from fecal samples of patients with diarrhea in Iran

    PubMed Central

    Alizade, Hesam; Fallah, Fatemeh; Ghanbarpour, Reza; Aflatoonian, Mohammad Reza; Goudarzi, Hossein; Sharifi, Hamid

    2015-01-01

    Aim: The aims of this study were to investigate the phenotypic and genotypic of extended-spectrum β-lactamase (ESBL) and metallo-β-lactamases (MBLs) and determine phylogenetic background E. coli isolates from fecal samples of patients with diarrhea in Kerman, southeast of Iran Background: The emergence of ESBLs and MBLs-producing E. coli caused problems in antibiotic treatments. E. coli strains can be assigned to four main phylog-groups, including: A, B1, B2 and D. Patients and methods: E. coli isolates (n=216) were obtained from fecal samples of patients with diarrhea between June and December 2013. ESBLs and MBLs were confirmed by disk-diffusion and broth micro-dilution methods. Using PCR, the ESBL-positive isolates were screened to determine the phylo-groups and the presence of blaCTX-M-15, blaOXA-1, blaPER-1, blaVIM and blaIMP genes. Results: ESBL-positive isolates (n= 56) were detected. Among ESBL-positive isolates, 51 isolates were positive for blaCTX-M15 and one isolate was positive for both blaCTX-M-15 and blaOXA-1 genes. None of the isolates were positive for blaPER-1, blaVIM and blaIMP genes. PCR assay for phylotyping of isolates indicated that the isolates were belonged to groups A (54.16%), B1 (11.11%), B2 (12.96%) and D (21.75%). The isolates possessed blaCTX-M-15 gene were belonged to A (35 isolates), B1 (5), B2 (3) and D (8) phylo-groups. Conclusion: Our results indicate that blaCTX-M-15 gene is widespread among diarrheagenic E. coli isolates. ESBL-producing E. coli isolates were disseminated among a diversity of phylo-groups. Further studies are necessary to identify the ESBL genes in relation to phylogenetic groups. PMID:26328043

  1. A snapshot of the predominant single nucleotide polymorphism cluster groups of Mycobacterium tuberculosis clinical isolates in Delhi, India.

    PubMed

    Varma-Basil, Mandira; Narang, Anshika; Chakravorty, Soumitesh; Garima, Kushal; Gupta, Shraddha; Kumar Sharma, Naresh; Giri, Astha; Zozio, Thierry; Couvin, David; Hanif, Mahmud; Bhatnagar, Anuj; Menon, Balakrishnan; Niemann, Stefan; Rastogi, Nalin; Alland, David; Bose, Mridula

    2016-09-01

    Several attempts have been made to associate phylogenetic differences among Mycobacterium tuberculosis strains to variations in the clinical outcome of the disease and to drug resistance. We genotyped 139 clinical isolates of M. tuberculosis obtained from patients of pulmonary tuberculosis in North Delhi region. The isolates were analyzed using nine Single nucleotide polymorphism (SNP) markers, spoligotyping and MIRU-VNTRs; and the results were correlated with their drug susceptibility profile. Results of SNP cluster group (SCG) analysis (available for 138 isolates) showed that the most predominant cluster was SCG 3a, observed in 58.7% (81/138) of the isolates with 44.4% (36/81) of these being drug susceptible, while 16% (13/81) were multidrug resistant (MDR). Of the ancestral cluster SCG 1 observed in 19.5% (27/138) of the isolates, 14.8% (4/27) were MDR while 44.4% (12/27) were drug susceptible. SCG 2 formed 5.79% (8/138) of the isolates and 50% (4/8) of these were multidrug resistant (MDR). Spoligotyping subdivided the strains into 45 shared types (n = 125) and 14 orphan strains. The orphan strains were mostly associated with SCG 3a or SCG 1, reflecting the principal SCGs found in the Indian population. SCG 1 and SCG 2 genotypes were concordant with the East African Indian (EAI) and Beijing families respectively. Central Asian (CAS) clade and its sublineages were predominantly associated with SCG 3a. No consistent association was seen between the SCGs and Harlem, T or X clades. The 15 loci MIRU-VNTR typing revealed 123/136 isolates to be unclustered, while 13 isolates were present in 6 clusters of 2-3 isolates each. However, correlating the cluster analysis with patient details did not suggest any evidence of recent transmission. In conclusion, though our study revealed the preponderance of SCG 1 and 3a in the M. tuberculosis population circulating in the region, the diversity of strains highlights the changes occurring within lineages and reemphasizes the

  2. Temporal isolation explains host-related genetic differentiation in a group of widespread mycoparasitic fungi.

    PubMed

    Kiss, Levente; Pintye, Alexandra; Kovács, Gábor M; Jankovics, Tünde; Fontaine, Michael C; Harvey, Nick; Xu, Xiangming; Nicot, Philippe C; Bardin, Marc; Shykoff, Jacqui A; Giraud, Tatiana

    2011-04-01

    Understanding the mechanisms responsible for divergence and specialization of pathogens on different hosts is of fundamental importance, especially in the context of the emergence of new diseases via host shifts. Temporal isolation has been reported in a few plants and parasites, but is probably one of the least studied speciation processes. We studied whether temporal isolation could be responsible for the maintenance of genetic differentiation among sympatric populations of Ampelomyces, widespread intracellular mycoparasites of powdery mildew fungi, themselves plant pathogens. The timing of transmission of Ampelomyces depends on the life cycles of the powdery mildew species they parasitize. Internal transcribed spacer sequences and microsatellite markers showed that Ampelomyces populations found in apple powdery mildew (Podosphaera leucotricha) were genetically highly differentiated from other Ampelomyces populations sampled from several other powdery mildew species across Europe, infecting plant hosts other than apple. While P. leucotricha starts its life cycle early in spring, and the main apple powdery mildew epidemics occur before summer, the fungal hosts of the other Ampelomyces cause epidemics mainly in summer and autumn. When two powdery mildew species were experimentally exposed to Ampelomyces strains naturally occurring in P. leucotricha in spring, and to strains naturally present in other mycohost species in autumn, cross-infections always occurred. Thus, the host-related genetic differentiation in Ampelomyces cannot be explained by narrow physiological specialization, because Ampelomyces were able to infect powdery mildew species they were unlikely to have encountered in nature, but instead appears to result from temporal isolation. PMID:21261766

  3. Isolation and identification of Pseudomonas syringae facilitated by a PCR targeting the whole P. syringae group.

    PubMed

    Guilbaud, Caroline; Morris, Cindy E; Barakat, Mohamed; Ortet, Philippe; Berge, Odile

    2016-01-01

    We present a reliable PCR-based method to avoid the biases related to identification based on the conventional phenotypes currently used in the identification of Pseudomonas syringae sensu lato, a ubiquitous environmental bacterium including plant pathogens. We identified a DNA target suitable for this purpose by applying a comparative genomic pipeline to Pseudomonas genomes. We designed primers and developed PCR conditions that led to a clean and strong PCR product from 97% of the 185 strains of P. syringae strains tested and gave a clear negative result for the 31 non-P. syringae strains tested. The sensitivity of standard PCR was determined with pure strains to be 10(6) bacteria mL(-1) or 0.4 ng of DNA μL(-1). Sensitivity could be improved with the touchdown method. The new PCR-assisted isolation of P. syringae was efficient when deployed on an environmental sample of river water as compared to the isolation based on phenotypes. This innovation eliminates the need for extensive expertise in isolating P. syringae colonies, was simpler, faster and very reliable. It will facilitate discovery of more diversity of P. syringae and research on emergence, dispersion and evolution to understand the varied functions of this environmental bacterium. PMID:26610434

  4. UV light-induced survival response in a highly radiation-resistant isolate of the Moraxella-acinetobacter group

    SciTech Connect

    Keller, L.C.; Thompson, T.L.; Maxcy, R.B.

    1982-02-01

    A highly radiation-resistant member of the Moraxella-Acinetobacter group, isolate 4, obtained from meat, was studied to determine the effect of preexposure to UV radiation on subsequent UV light resistance. Cultures that were preexposed to UV light and incubated for a short time in plate count broth exhibited increased survival of a UV light challenge dose. This response was inhibited in the presence of chloramphenicol. Frequencies of mutation to streptomycin, trimethoprim, and sulfanilamide resistance remained the same after the induction of this survival response and were not altered by treatment with mutagens, with the exception of mutation to streptomycin resistance after ..gamma..-irradiation or nitrosoguanidine or methyl methane sulfonate treatment. The results indicated that isolate 4 has a UV light-inducible UV light resistance mechanism which is not associated with increased mutagenesis. The characteristics of the radiation resistance response in this organism are similar to those of certain other common food contaminants. Therefore, considered as part of the total microflora of meat, isolate 4 and the other radiation-resistant Moraxella-Acinetobacter isolates should not pose unique problems in a proposed radappertizaton process.

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

    PubMed

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

    2015-03-01

    Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of shock, multi-organ failure, and high mortality. In Japan, appropriate notification measures based on the Infectious Disease Control law are mandatory for cases of STSS caused by β-haemolytic streptococcus. STSS is mainly caused by group A streptococcus (GAS). Although an average of 60-70 cases of GAS-induced STSS are reported annually, 143 cases were recorded in 2011. To determine the reason behind this marked increase, we characterized the emm genotype of 249 GAS isolates from STSS patients in Japan from 2010 to 2012 and performed antimicrobial susceptibility testing. The predominant genotype was found to be emm1, followed by emm89, emm12, emm28, emm3, and emm90. These six genotypes constituted more than 90% of the STSS isolates. The number of emm1, emm89, emm12, and emm28 isolates increased concomitantly with the increase in the total number of STSS cases. In particular, the number of mefA-positive emm1 isolates has escalated since 2011. Thus, the increase in the incidence of STSS can be attributed to an increase in the number of cases associated with specific genotypes. PMID:25703404

  6. Unusual groups of Morganella ("Proteus") morganii isolated from clinical specimens: lysine-positive and ornithine-negative biogroups.

    PubMed Central

    Hickman, F W; Framer, J J; Steigerwalt, A G; Brenner, D J

    1980-01-01

    Morganella ("Proteus") morganii is the only species in the recently proposed genus Morganella, but we suspect there are yet undescribed species in the genus. Two candidates for new species were recently investigated. Nineteen strains isolated from clinical specimens resembled M. morganii but were lysine positive and nonmotile and fermented glycerol within 24 h. Typical M. morganii are lysine negative and motile and ferment glycerol slowly or not at all. The three-test variance from typical M. morganii suggested that this new group might be a new Morganella species; however, strains of the group were closely related to typical M. morganii by deoxyribonucleic acid (DNA)-DNA hybridization. A second group of 14 strains isolated from clinical specimens was ornithine negative but was otherwise very similar to M. morganii. This group was also closely related to M. morganii by DNA hybridization. Both sets of strains clearly belong in the species Morganella morganii as distinct biogroups; they are not separate species as originally suspected. Initially both biogroups posed a problem in identification until their true relationship to M. morganii was determined. PMID:6775010

  7. Identification and Genomic Analysis of a Novel Group C Orthobunyavirus Isolated from a Mosquito Captured near Iquitos, Peru

    PubMed Central

    Treangen, Todd J.; Schoeler, George; Phillippy, Adam M.; Bergman, Nicholas H.; Turell, Michael J.

    2016-01-01

    Group C orthobunyaviruses are single-stranded RNA viruses found in both South and North America. Until very recently, and despite their status as important vector-borne human pathogens, no Group C whole genome sequences containing all three segments were available in public databases. Here we report a Group C orthobunyavirus, named El Huayo virus, isolated from a pool of Culex portesi mosquitoes captured near Iquitos, Peru. Although initial metagenomic analysis yielded only a handful of reads belonging to the genus Orthobunyavirus, single contig assemblies were generated for L, M, and S segments totaling over 200,000 reads (~0.5% of sample). Given the moderately high viremia in hamsters (>107 plaque-forming units/ml) and the propensity for Cx. portesi to feed on rodents, it is possible that El Huayo virus is maintained in nature in a Culex portesi/rodent cycle. El Huayo virus was found to be most similar to Peruvian Caraparu virus isolates and constitutes a novel subclade within Group C. PMID:27074162

  8. Identification and Genomic Analysis of a Novel Group C Orthobunyavirus Isolated from a Mosquito Captured near Iquitos, Peru.

    PubMed

    Treangen, Todd J; Schoeler, George; Phillippy, Adam M; Bergman, Nicholas H; Turell, Michael J

    2016-04-01

    Group C orthobunyaviruses are single-stranded RNA viruses found in both South and North America. Until very recently, and despite their status as important vector-borne human pathogens, no Group C whole genome sequences containing all three segments were available in public databases. Here we report a Group C orthobunyavirus, named El Huayo virus, isolated from a pool of Culex portesi mosquitoes captured near Iquitos, Peru. Although initial metagenomic analysis yielded only a handful of reads belonging to the genus Orthobunyavirus, single contig assemblies were generated for L, M, and S segments totaling over 200,000 reads (~0.5% of sample). Given the moderately high viremia in hamsters (>107 plaque-forming units/ml) and the propensity for Cx. portesi to feed on rodents, it is possible that El Huayo virus is maintained in nature in a Culex portesi/rodent cycle. El Huayo virus was found to be most similar to Peruvian Caraparu virus isolates and constitutes a novel subclade within Group C. PMID:27074162

  9. Genetic survey of an isolated community in Bali, Indonesia. I. Blood groups, serum proteins and hepatitis B serology.

    PubMed

    Breguet, G; Ney, R; Grimm, W; Hope, S L; Kirk, R L; Blake, N M; Narendra, I B; Toha, A

    1982-01-01

    320 adults and children of an isolated community of Bali, Indonesia, have been tested for blood groups ABO, Rh, MNS, P, Lewis, Duffy, Kell, for haptoglobin and transferrin and for hepatitis B surface antigen and antibodies. Phenotype distribution and gene frequencies are given for the total population tested and for two subgroups representative of the inbred population of the isolate and of the non-inbred part of the population. Significant differences between the two subgroups show a clear genetic drift in the inbred population. The study brings biological support to the ethnological hypothesis of population migrations in this area. Tests for hepatitis B surface antigen reveal a lower prevalence of the disease than in most other south-east Asian populations. PMID:7068159

  10. Evaluation of four chromogenic media for the isolation of Group B Streptococcus from vaginal specimens in pregnant women.

    PubMed

    Salem, Nahim; Anderson, Jeffrey J

    2015-10-01

    Direct culture onto four commercial chromogenic media, selective for the isolation of Group B Streptococcus (GBS), were compared with the conventional pre-enrichment Centers for Disease Control and Prevention (CDC) method for the ability to isolate GBS from 242 pregnant women's self-collected vaginal/perineal swabs. The sensitivities and specificities for direct culture on to chromogenic agar were 92% and 100% for StrepBSelect (Bio-Rad Laboratories), 96% and 100% for Brilliance GBS (Thermo-Fisher Scientific), 94% and 100% for CHROMagar StrepB (CHROMagar, Dutec Diagnostics), 86% and 100% for ChromID Strepto B (bioMerieux). CDC recommended broth pre-enrichment then culture on blood containing selective agar had a sensitivity and specificity of 90.0% and 100% respectively. The chromogenic agar tested produced comparable results to the pre-enrichment CDC method. PMID:26308132

  11. Antibiotic Susceptibility Pattern of Aerobic and Anaerobic Bacteria Isolated From Surgical Site Infection of Hospitalized Patients

    PubMed Central

    Akhi, Mohammad Taghi; Ghotaslou, Reza; Beheshtirouy, Samad; Asgharzadeh, Mohammad; Pirzadeh, Tahereh; Asghari, Babak; Alizadeh, Naser; Toloue Ostadgavahi, Ali; Sorayaei Somesaraei, Vida; Memar, Mohammad Yousef

    2015-01-01

    Background: Surgical Site Infections (SSIs) are infections of incision or deep tissue at operation sites. These infections prolong hospitalization, delay wound healing, and increase the overall cost and morbidity. Objectives: This study aimed to investigate anaerobic and aerobic bacteria prevalence in surgical site infections and determinate antibiotic susceptibility pattern in these isolates. Materials and Methods: One hundred SSIs specimens were obtained by needle aspiration from purulent material in depth of infected site. These specimens were cultured and incubated in both aerobic and anaerobic condition. For detection of antibiotic susceptibility pattern in aerobic and anaerobic bacteria, we used disk diffusion, agar dilution, and E-test methods. Results: A total of 194 bacterial strains were isolated from 100 samples of surgical sites. Predominant aerobic and facultative anaerobic bacteria isolated from these specimens were the members of Enterobacteriaceae family (66, 34.03%) followed by Pseudomonas aeruginosa (26, 13.4%), Staphylococcus aureus (24, 12.37%), Acinetobacter spp. (18, 9.28%), Enterococcus spp. (16, 8.24%), coagulase negative Staphylococcus spp. (14, 7.22%) and nonhemolytic streptococci (2, 1.03%). Bacteroides fragilis (26, 13.4%), and Clostridium perfringens (2, 1.03%) were isolated as anaerobic bacteria. The most resistant bacteria among anaerobic isolates were B. fragilis. All Gram-positive isolates were susceptible to vancomycin and linezolid while most of Enterobacteriaceae showed sensitivity to imipenem. Conclusions: Most SSIs specimens were polymicrobial and predominant anaerobic isolate was B. fragilis. Isolated aerobic and anaerobic strains showed high level of resistance to antibiotics. PMID:26421133

  12. Isolation of Hypervalent Group-16 Radicals and Their Application in Organic-Radical Batteries.

    PubMed

    Imada, Yasuyuki; Nakano, Hideyuki; Furukawa, Ko; Kishi, Ryohei; Nakano, Masayoshi; Maruyama, Hitoshi; Nakamoto, Masaaki; Sekiguchi, Akira; Ogawa, Masahiro; Ohta, Toshiaki; Yamamoto, Yohsuke

    2016-01-20

    Using a newly prepared tridentate ligand, we isolated hypervalent sulfur and selenium radicals for the first time and characterized their structures. X-ray crystallography, electron spin resonance spectroscopy, and density functional theory calculations revealed a three-coordinate hypervalent structure. Utilizing the reversible redox reactions between hypervalent radicals and the corresponding anions bearing Li(+), we developed organic radical batteries with these compounds as cathode-active materials. Furthermore, an all-radical battery, with these compounds as the cathode and a silyl radical as the anode, was developed that exhibited a practical discharge potential of ∼ 1.8 V and stable cycle performance, demonstrating the potential of these materials for use in metal-free batteries that can replace conventional Li-ion batteries where Li is used in the metal form. PMID:26721786

  13. Genetic heterogeneity in wild isolates of cellular slime mold social groups.

    PubMed

    Sathe, Santosh; Kaushik, Sonia; Lalremruata, Albert; Aggarwal, Ramesh K; Cavender, James C; Nanjundiah, Vidyanand

    2010-07-01

    This study addresses the issues of spatial distribution, dispersal, and genetic heterogeneity in social groups of the cellular slime molds (CSMs). The CSMs are soil amoebae with an unusual life cycle that consists of alternating solitary and social phases. Because the social phase involves division of labor with what appears to be an extreme form of "altruism", the CSMs raise interesting evolutionary questions regarding the origin and maintenance of sociality. Knowledge of the genetic structure of social groups in the wild is necessary for answering these questions. We confirm that CSMs are widespread in undisturbed forest soil from South India. They are dispersed over long distances via the dung of a variety of large mammals. Consistent with this mode of dispersal, most social groups in the two species examined for detailed study, Dictyostelium giganteum and Dictyostelium purpureum, are multi-clonal. PMID:20179919

  14. Structural characterization of neutral oligosaccharides with blood-group A and H activity isolated from bovine submaxillary mucin.

    PubMed Central

    Savage, A V; D'Arcy, S M; Donoghue, C M

    1991-01-01

    In this study we investigated the structures of 11 neutral oligosaccharides released from bovine submaxillary mucin by alkaline borohydride treatment and isolated by h.p.l.c. One hexa-, one penta-, three tetra-, four tri- and two di-saccharides containing core types 1, 2, 3 or 4 were obtained. We report their structures, determined by a combination of one- and two-dimensional 1H n.m.r. spectroscopy at 270 MHz and methylation analysis involving g.l.c.-m.s., along with their approximate molar ratios. Only three of these oligosaccharides have previously been reported in this source. Of the new oligosaccharides, one contains the blood-group-A antigenic determinant, two contain the blood-group-H type 2 determinant, while another contains the blood-group-H type 3 determinant. The oligosaccharide GlcNAc beta (1----6)[GlcNAc beta (1----3)]GalNAcol, although previously found as a core structure, has been isolated here as a novel trisaccharide. PMID:1718265

  15. [Yearly changes in antibacterial activities of cefozopran against various clinical isolates between 1996 and 2001--II. Gram-negative bacteria].

    PubMed

    Suzuki, Yumiko; Nishinari, Chisato; Endo, Harumi; Hiramatsu, Nobuyoshi; Akiyama, Kazumitsu; Koyama, Tsuneo

    2003-08-01

    The in vitro antibacterial activities of cefozopran (CZOP), an agent of cephems, against various clinical isolates obtained between 1996 and 2001 were yearly evaluated and compared with those of other cephems, oxacephems and carbapenems. A total of 3,245 strains in 32 species of Gram-negative bacteria were isolated from the clinical materials annually collected from January to December, and consisted of Moraxella subgenus Branhamella catarrhalis, Escherichia coli, Citrobacter freundii, Citrobacter koseri, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae, Serratia marcescens, Proteus mirabillis, Proteus vulgaris, Morganella morganii, Providencia spp. (P. alcalifaciens, P. rettgeri, P. stuartii), Pseudomonas aeruginosa, Pseudomonas putida, Burkholderia cepacia, Stenotrophomonas maltophilia, Haemophilus influenzae, Acinetobactor baumannii, Acinetobactor lwoffii, Bacteroides fragilis group (B. fragilis, B. vulgatus, B. distasonis, B. ovatus, B. thetaiotaomicron), and Prevotella spp. (P. melaninogenica, P. intermedia, P. bivia, P. oralis, P. denticola). CZOP possessed stable antibacterial activities against M. (B.) catarrhalis, E. coli, C. freundii, C. koseri, K. pneumoniae, K. oxytoca, E. aerogenes, E. cloacae, S. marcescens, P. mirabilis, P. vulgaris, M. morganii, Providencia spp., P. aeruginosa, and A. lwoffii throughout 6 years. The MIC90 of CZOP against those strains were consistent with those obtained from the studies performed until the new drug application approval. On the other hand, the MIC90 of CZOP against H. influenzae yearly obviously increased with approximately 64-time difference during the study period. The MIC90 of cefpirome, cefepime, and flomoxef against H. influenzae also yearly tended to rise. The present results demonstrated that CZOP had maintained the antibacterial activity against almost Gram-negative strains tested. However, the decrease in antibacterial activities of CZOP against B. cepacia, and H

  16. Prevalence of Dientamoeba fragilis, Giardia duodenalis, Entamoeba histolytica/dispar, and Cryptosporidium spp in Da Nang, Vietnam, detected by a multiplex real-time PCR.

    PubMed

    Ögren, Jessica; Van Nguyen, Song; Nguyen, Minh Khac; Dimberg, Jan; Matussek, Andreas

    2016-06-01

    We surveyed the prevalence of Dientamoeba fragilis, Giardia duodenalis, Entamoeba histolytica, Entamoeba dispar, and Cryptosporidium spp in individuals with and without gastrointestinal (GI) symptoms residing in and around Da Nang city, Vietnam. Fecal samples were collected from children (n = 100) and adults (n = 80) with GI symptoms and from healthy individuals (n = 88) reporting no GI symptoms. Parasite detection was performed by multiplex real-time PCR. Overall, except for G. duodenalis, we found a low prevalence (<5%) of D. fragilis and E. dispar and no detection of E. histolytica and C. spp in all participants with GI symptoms. Specifically for D. fragilis this contrasts with findings in European populations of children with GI symptoms showing prevalence up to 73%. Moreover, our results indicate that the prevalence of G. duodenalis is higher in patients with GI symptoms compared to asymptomatic individuals and this difference is most obvious in young patients. PMID:27102222

  17. Comparison of a homemade blood culture broth containing a papain digest of liver, with four commercially available media for the isolation of anaerobes from simulated paediatric blood cultures.

    PubMed Central

    Hunt, G H; Price, E H

    1982-01-01

    The recovery of small inocula of fastidious organisms, mainly non-sporing anaerobes, was studied in simulated paediatric blood culture experiments where only 1.5 ml of blood was added to each broth. A 25 ml homemade Queen Elizabeth Hospital medium (QEH medium) containing a papain digest of liver showed the best overall performance during the first four days of incubation; this medium was also satisfactory for maintenance of the majority of the organisms tested for longer than one week. LAB M Fastidious Anaerobe Broth (75 ml) with thymidine, also showed early isolation and satisfactory survival of most organisms. Difco Thiol broth, 50 ml with Liquoid, yielded early growth of the three strains of Bacteroides fragilis tested and maintained these organisms well; however, variable results were obtained with some other organisms in Difco Thiol media. Southern Group Brewer's thioglycollate broth (80 ml) gave the least satisfactory performance. PMID:6752208

  18. Pseudomonas aeruginosa isolates from dental unit waterlines can be divided in two distinct groups, including one displaying phenotypes similar to isolates from cystic fibrosis patients

    PubMed Central

    Ouellet, Myriam M.; Leduc, Annie; Nadeau, Christine; Barbeau, Jean; Charette, Steve J.

    2015-01-01

    Pseudomonas aeruginosa displays broad genetic diversity, giving it an astonishing capacity to adapt to a variety of environments and to infect a wide range of hosts. While many P. aeruginosa isolates of various origins have been analyzed, isolates from cystic fibrosis (CF) patients have received the most attention. Less is known about the genetic and phenotypic diversity of P. aeruginosa isolates that colonize other environments where flourishing biofilms can be found. In the present study, 29 P. aeruginosa isolates from dental unit waterlines and CF patients were collected and their genetic and phenotypes profiles were compared to determine whether environmental and clinical isolates are related. The isolates were first classified using the random amplified polymorphic DNA method. This made it possible to distribute the isolates into one clinical cluster and two environmental clusters. The isolates in the environmental cluster that were genetically closer to the clinical cluster also displayed phenotypes similar to the clinical isolates. The isolates from the second environmental cluster displayed opposite phenotypes, particularly an increased capacity to form biofilms. The isolates in this cluster were also the only ones harboring genes that encoded specific epimerases involved in the synthesis of lipopolysaccharides, which could explain their increased ability to form biofilms. In conclusion, the isolates from the dental unit waterlines could be distributed into two clusters, with some of the environmental isolates resembled the clinical isolates. PMID:25653647

  19. Use of Zymomonas mobilis and Saccharomyces cerevisiae mixed with Kluyveromyces fragilis for improved ethanol production from Jerusalem artichoke tubers.

    PubMed

    Szambelan, Katarzyna; Nowak, Jacek; Czarnecki, Zbigniew

    2004-05-01

    Jerusalem artichoke mashed tubers were fermented using single yeasts and a bacterium as well as mixed culture of microorganisms. Kluyveromyces fragilis, a yeast with an active inulinase, was used together with either a commercial distillery yeast, Saccharomyces cerevisiae, or the bacterium Zymomonas mobilis. After batch fermentation the best ethanol concentration of 0.48 g g(-1) for the mixed population and 0.46 g g(-1) for the single population can be obtained. The theoretical yield of the mixed cultures was 2-12% higher than for the single microorganism. PMID:15269559

  20. Rediscovery and a new record of Hemidactylus laevis (Reptilia: Gekkonidae) from Somaliland, with notes on and resurrection of Hemidactylus fragilis.

    PubMed

    Mazuch, Tomáš; Šmíd, Jiří; Bauer, Aaron M

    2016-01-01

    Hemidactylus laevis, a gekkonid lizard originally described from the Gaan Libah Mountains in Somaliland, is recorded herein from Erigavo, Sanaag Region, in the same state, which represents the second-ever known specimen and locality for this species in more than 100 years since its description. The species is endemic to Somaliland. Data on morphology and natural history, as well as the first life photographs are provided. Based on morphological data we conclude the species to be closely related to H. laticaudatus. Additionally, H. fragilis from southern Somalia and extreme south-east Ethiopia is resurrected from the synonymy of H. frenatus based on morphological data. PMID:27395191

  1. Diversity of DIS, SD and psi hairpins in HIV-1 isolates of group M: in silico study.

    PubMed

    Zarudnaya, M I; Potyahaylo, A L; Kolomiets, I N; Hovorun, D M

    2007-01-01

    The primary sequence and secondary structure of the region encompassing DIS, SD and psi hairpins in HIV-1 genomic RNAs have been analyzed for 731 group M isolates from NCBI database. The secondary structures have been predicted by the m fold program (M. Zuker). Though the primary sequence of the region studied was found to be highly heterogeneous, this region is folded into DIS, SD and psi hairpins (DIS-, SD- and psi-like hairpins) in 96% of the isolates studied. The phylogenetic analysis showed that the most frequent variants of DIS hairpin (DIS(Lai), DIS(Mal) and DIS(C)) tolerate certain base changes. Particularly, base changes at stem position 23 occur 5 and 33 times more frequently in DIS(Lai) than in DIS(Mal) and DIS(C), respectively, while A insertion at the 5'end of apical loop is tolerated in DIS(Mal) and DIS(C) but not in DIS(Lai). We have revealed that the bottom base pair substitution G-C --> A-U in SD hairpin is highly specific for subtype D isolates. All variants of DIS, SD and psi hairpins found in our database are discussed, systematized and presented in schemes of hypothetical transitions between variants via a single base change. Most variants of DIS and psi hairpins were found to adopt several conformations. PMID:18030736

  2. Evaluation of the ATB 32 A system for identification of anaerobic bacteria isolated from clinical specimens.

    PubMed Central

    Looney, W J; Gallusser, A J; Modde, H K

    1990-01-01

    A new miniaturized 4-h method for the identification of anaerobic bacteria, ATB 32 A (API System SA, Montalieu Vercieu, France), was evaluated against conventional methods of identification. The evaluation was done by using 260 recent clinical isolates and 21 reference strains of anaerobic bacteria. All reference strains were correctly identified and did not figure in the detailed analysis. Of the 140 gram-negative bacilli, 90.6% of Bacteroides spp. and 95.5% of Fusobacterium spp. were correctly identified to the species level, with an additional 8.4% of the Bacteroides spp. being identified to the genus level. Clostridia were correctly identified in 85.9% of cases, with an additional 9.9% being identified to the genus level. Peptostreptococci were correctly identified in 91.6% of cases. The 4 strains of Actinomyces spp. were all identified correctly, as were 10 of the 11 strains of Propionibacterium spp. A total of 3.1% of strains were not identified by ATB 32 A, while for 1.9% of strains, completely false identifications were obtained. Estimation of the individual preformed enzyme results may pose problems, although these decrease with familiarity with the system. With certain enzyme profiles, additional testing was necessary to arrive at an identification; however, there was no requirement for gas-liquid chromatography. If certain additions are made to the data base and the difficulties of determination of organisms to the species level among the non-Bacteroides fragilis (sensu stricto) members of the B. fragilis group can be reduced, this system holds promise as a reliable standardized alternative for the identification of anaerobic bacteria in clinical laboratories. PMID:2199516

  3. Comparison of the activity of imipenem and beta-lactams combined with sulbactam and clavulanic acid in beta-lactamase-producing strains of Bacteroides fragilis.

    PubMed

    Martín, M A; Castillo, A M; Liébana, J; Marín, A; Alados, J C; Piédrola, G

    1991-01-01

    We compared the "in vitro" activity of imipenem with 14 beta-lactams, both alone and in combination with clavulanic acid, and sulbactam against 110 beta-lactamase-producing strains of Bacteroides fragilis. The following antibiotics were tested: amoxycillin, penicillin, mezlocillin, piperacillin, cephalothin, cephazolin, cefamandole, cefmetazole, cefonicid, cefoxitin, cefotaxime, ceftazidime, ceftizoxime, and ceftriaxone. In all cases, except those of cefoxitin and cefmetazole, these combinations showed a statistically significant increase in beta-lactam activity, which was, however, never higher than that of imipenem, the antibiotic which performed best against Bacteroides fragilis. PMID:1940333

  4. [Study on virulence factors associated with biofilm formation and phylogenetic groupings in Escherichia coli strains isolated from patients with cystitis].

    PubMed

    Tiba, Monique Ribeiro; Nogueira, Gustavo Prado; Leite, Domingos da Silva

    2009-01-01

    Escherichia coli samples isolated from female patients with cystitis were characterized with regard to the presence of virulence factors associated with biofilm formation and phylogenetic groupings. Polymerase chain reaction results demonstrated that all the samples were positive for the gene fimH (type 1 fimbriae), 91 for fliC (flagellins), 50 for papC (P fimbriae), 44 for kpsMTII (capsules) and 36 for flu (antigen 43). The results from assays to quantify the biofilm formation demonstrated that 44 samples produced biofilm on polystyrene microplates and 56 samples produced weak or no biofilm. We also confirmed that Escherichia coli samples were present in phylogenetic groups B2 and D. PMID:19287937

  5. Increasing antimicrobial resistance in clinical isolates of Staphylococcus intermedius group bacteria and emergence of MRSP in the UK.

    PubMed

    Beever, L; Bond, R; Graham, P A; Jackson, B; Lloyd, D H; Loeffler, A

    2015-02-14

    Frequencies of antimicrobial resistance were determined amongst 14,555 clinical Staphylococcus intermedius group (SIG) isolates from UK dogs and cats to estimate resistance trends and quantify the occurrence of meticillin-resistant Staphylococcus pseudintermedius (MRSP). Reports from two diagnostic laboratories (13,313 general submissions, 1242 referral centre only submissions) were analysed retrospectively (2003/2006-2012). MRSP were defined by phenotypic resistance to meticillin and concurrent broad β-lactam resistance; a subset was confirmed genetically (SIG-specific nuc and mecA). Trends were analysed by Cochran-Armitage test. Resistance remained below 10 per cent for cefalexin, amoxicillin-clavulanic acid and the fluoroquinolones. Increasing resistance trends were seen in both laboratories for ampicillin/amoxicillin (both P<0.001), cefovecin (both P<0.046) and enrofloxacin (both P<0.02). Resistance to cefalexin increased over time in referral hospital isolates (P<0.001) to clindamycin (P=0.01) and trimethoprim-sulfamethoxazole (P=0.001) amongst general laboratory submissions. Overall, 106 MRSP were isolated (0.7 per cent of submissions) including 32 (2.6 per cent of submissions, all genetically confirmed) from the referral centre population (inter-laboratory difference P<0.001). Against a background of widely susceptible SIG isolates, a new trend of increasing resistance to important antimicrobials was identified overtime and the emergence of MRSP from UK clinical cases was confirmed. Attention to responsible use of antibacterial therapy in small animal practice is urgently needed. PMID:25376505

  6. Isolation of a very high molecular weight polylactosamine from an ovarian cyst mucin of blood group

    SciTech Connect

    Wu, A.S.S.; Bush, C.A.

    1986-05-01

    Treatment of a blood group A active ovarian cyst mucin glycoprotein with alkaline borohydride under conditions expected to cleave-O-glycosidically linked carbohydrate chains releases a polysaccharide of average molecular weight 25,000 daltons. It contains no peptide or mannose at the 1% level and carbohydrate analysis gives fuc:galNAc:gal:glcNAc in the ratio of 1:1:2.5:2.5. The /sup 13/C and /sup 1/H NMR spectra show that the polysaccharide has non-reducing terminal side chains of the structure galNAc(..cap alpha..-1 ..-->.. 3)(fuc(..cap alpha..-1 ..-->.. 2)) gal(..beta..-1 ..-->.. 3) glcNAc (i.e. a type 1 chain). Periodate oxidation removes all the fucose and galNAc from the non-reducing terminal but leaves intact the backbone composed of ..beta..-linked gal and glcNAc as would be expected for a polylactosamine. They conclude that this is a high molecular weight polylactosamine which is related to the asparagine linked polylactosamine chains of cell surface glycoproteins which have been implicated in cell differentiation. However, the blood group A polysaccharide from the ovarian cyst mucin is unique in several respects. It has a much larger molecular weight than even the erythroglycan of the red cell membrane protein, band 3, and is linked to the protein by an -O-glycosidic bond rather than the -N-asparagine linkage of the previously known polylactosamines which have a trimannosyl core. Its blood group A side chains are on a type one core rather than type 2 which is found on other polylactosamines.

  7. Antimicrobial resistance in fecal Escherichia coli isolates from healthy urban children of two age groups in relation to their antibiotic therapy.

    PubMed

    Literak, Ivan; Petro, Radim; Dolejska, Monika; Gruberova, Erika; Dobiasova, Hana; Petr, Jan; Cizek, Alois

    2011-06-01

    The study was performed in the Czech Republic during 2007 to 2009. Of Escherichia coli isolates from 275 children aged 6 weeks, 36% (n = 177) were resistant to 1 to 7 antibiotics. Of isolates from 253 children aged 6 to 17 years, 24% (n = 205) were resistant to 1 to 5 antibiotics. There was no significant difference in the prevalences of antibiotic-resistant E. coli isolates between these groups of children, even though the consumptions of antibiotics were quite different. PMID:21464246

  8. Antimicrobial Resistance in Fecal Escherichia coli Isolates from Healthy Urban Children of Two Age Groups in Relation to Their Antibiotic Therapy▿

    PubMed Central

    Literak, Ivan; Petro, Radim; Dolejska, Monika; Gruberova, Erika; Dobiasova, Hana; Petr, Jan; Cizek, Alois

    2011-01-01

    The study was performed in the Czech Republic during 2007 to 2009. Of Escherichia coli isolates from 275 children aged 6 weeks, 36% (n = 177) were resistant to 1 to 7 antibiotics. Of isolates from 253 children aged 6 to 17 years, 24% (n = 205) were resistant to 1 to 5 antibiotics. There was no significant difference in the prevalences of antibiotic-resistant E. coli isolates between these groups of children, even though the consumptions of antibiotics were quite different. PMID:21464246

  9. [Hazardous health effect of isolation. A clinical study of 2 groups of persons in custody].

    PubMed

    Gamman, T

    1995-08-10

    The possible effects of solitary confinement on prisoners' health were studied using a prospective design. 27 secluded prisoners were compared with 27 others who were held in custody. The latter group of prisoners was able to see other prisoners, visitors, friends and family members, and could participate in prison activities. The results showed that secluded prisoners had more health problems than prisoners serving less restrictive prison sentences did. The most usual complaints were headache, pain in the neck, stomach and shoulders, anxiety and depression. Psychotic symptoms were rare. The complaints tended to last for the whole period of solitary confinement and were difficult to treat while the prisoners remained secluded. Patients with chronic somatic diseases tended to deteriorate in solitary confinement. Most patients recovered when the seclusion was terminated. PMID:7652720

  10. Extensive introgressive hybridization within the northern oriole group (Genus Icterus) revealed by three-species isolation with migration analysis

    PubMed Central

    Jacobsen, Frode; Omland, Kevin E

    2012-01-01

    Until recently, studies of divergence and gene flow among closely-related taxa were generally limited to pairs of sister taxa. However, organisms frequently exchange genes with other non-sister taxa. The “northern oriole” group within genus Icterus exemplifies this problem. This group involves the extensively studied hybrid zone between Baltimore oriole (Icterus galbula) and Bullock's oriole (I. bullockii), an alleged hybrid zone between I. bullockii and black-backed oriole (I. abeillei), and likely mtDNA introgression between I. galbula and I. abeillei. Here, we examine the divergence population genetics of the entire northern oriole group using a multipopulation Isolation-with-Migration (IM) model. In accordance with Haldane's rule, nuclear loci introgress extensively beyond the I. galbula–I. bullockii hybrid zone, while mtDNA does not. We found no evidence of introgression between I. bullockii and I. abeillei or between I. galbula and I. abeillei when all three species were analyzed together in a three-population model. However, traditional pairwise analysis suggested some nuclear introgression from I. abeillei into I. galbula, probably reflecting genetic contributions from I. bullockii unaccounted for in a two-population model. Thus, only by including all members of this group in the analysis was it possible to rigorously estimate the level of gene flow among these three closely related species. PMID:23145328

  11. NAD- and NADP-dependent 7alpha-hydroxysteroid dehydrogenases from bacteroides fragilis.

    PubMed

    Macdonald, I A; Williams, C N; Mahony, D E; Christie, W M

    1975-03-28

    Twenty strains of Bacteroides fragilis were screened for hydroxysteroid oxidoreductase activity in cell-free preparations. Eighteen strains were shown to contain NAD-dependent 7alpha-hydroxysteroid dehydrogenase. Sixteen of the strains containing the NAD-dependent enzyme also contained NADP-depedent 7alpha-hydroxysteroid dehydrogenase, but invariably in lesser amounts. A strain particulary rich in both 7alpha-hydroxysteroid dehydrogenase activities was selected for further study. Measurement of activity as a function of pH revealed a fairly sharp optimal activity range of 9.5--10.0 for the NAD-dependent enzyme and a broad flat optimal range of 7.0--9.0 for the NADP-dependent enzyme. Michaelis constants for trihydroxy-bile acids for the NAD-dependent enzyme were in the range of 0.32--0.34 mM, whereas dihydroxy-bile acids gave a Km of 0.1 mM. Thin-layer chromatography studies on the oxidation product of 3alpha, 7alpha-dihydroxy-5beta-cholanoic acid (chenodeoxycholic acid) by the dehydrogenase revealed a band corresponding to that of synthetic 3alpha-hydroxy, 7-keto-5beta-cholanoic acid. Similarly the oxidation product of chenodeoxycholic acid by both 7alpha-hydroxysteroid dehydrogenase and commercially available 3alpha-hy-droxysteroid dehydrogenase revealed a band corresponding to that of synthetic 3,7-diketo-5beta-cholanoic acid. Neither of these two oxidation products could be distinguished from those by the Escherichia coli dehydrogenase oxidation previously reported. Disc-gel electrophoresis of a cell-free lyophilized preparation indicated one active band for NAD-dependent activity of mobility similar to that for the NADP-dependent E. coli enzyme. The NADP-dependent dehydrogenase was unstable and rapidly lost activity after polyacylamide disc-gel electrophoresis, ultracentrifugation, freezing on refrigeration at 4 degrees C. No 3 alpha- or 12alpha-oriented oxidoreductase activity was demonstrated in any of the strains examined. PMID:236764

  12. Efficient and regioselective synthesis of globotriose by a novel α-galactosidase from Bacteroides fragilis.

    PubMed

    Gong, Wei; Xu, Li; Gu, Guofeng; Lu, Lili; Xiao, Min

    2016-08-01

    Globotriose (Galα1-4Galβ1-4Glc) is an important cell surface epitope that acts as the receptor for Shiga-like toxins, and it is also the core structure of Globo H and SSEA4 that are tumor-associated glycans. Hence, the enzymatic synthesis of globotriose would be necessary for the development of carbohydrate-based therapeutics for bacterial infections and cancers. Here, a novel GH27 α-galactosidase gene (agaBf3S), a 1521-bp DNA encoding 506 amino acids with a calculated molecular mass of 57.7 kDa, from Bacteroides fragilis NCTC9343 was cloned and heterogeneously expressed in Escherichia coli. The recombinant enzyme AgaBf3S preferentially hydrolyzed p-nitrophenyl-α-D-galactopyranoside (pNPαGal) in all tested nitrophenyl glycosides. It showed maximum activity at pH 4.5 and 40 °C, and it was stable at pH 4.0-11.0 below 40 °C and metal-independent. The K m and k cat values for pNPαGal, melibiose, and globotriose were 1.27 mM and 172.97 S(-1), 62.76 mM and 17.74 S(-1), and 4.62 mM and 388.45 S(-1), respectively. AgaBf3S could transfer galactosyl residue from pNPαGal to lactose (Galβ1-4Glc) with high efficiency and strict α1-4 regioselectivity. The effects of initial substrate concentration, pH, temperature, and reaction time on transglycosylation reaction catalyzed by AgaBf3S were studied in detail. AgaBf3S could synthesize globotriose as a single transglycosylation product with a maximum yield of 32.4 % from 20 mM pNPαGal and 500 mM lactose (pH 4.5) at 40 °C for 30 min. This new one-enzyme one-step synthetic reaction is simple, fast, and low cost, which provides a promising alternative to the current synthetic methods for access to pharmaceutically important Galα1-4-linked oligosaccharides. PMID:27020280

  13. Aeromonas jandaei (formerly genospecies DNA group 9 A. sobria), a new sucrose-negative species isolated from clinical specimens.

    PubMed Central

    Carnahan, A; Fanning, G R; Joseph, S W

    1991-01-01

    . The esculin-, sucrose-, and cellobiose-negative and colistin-resistant profile distinguished A. jandaei from other Aeromonas species. These A. jandaei strains were isolated from blood (two strains), wounds (two strains), diarrheal stools (four strains), and a prawn (one strain). The blood and wound isolates, in particular, suggest that there is a possible clinical significance for this species and justify identification of and further research on this group of motile aeromonads. PMID:2037673

  14. Population structure and characterization of viridans group streptococci (VGS) isolated from the upper respiratory tract of patients in the community

    PubMed Central

    Nakajima, Takuya; Nakanishi, Shigeyuki; Mason, Charlene; Montgomery, Janice; Leggett, Paul; Matsuda, Motoo; Coulter, Wilson A.; Millar, B. Cherie; Goldsmith, Colin E.; Moore, John E.

    2013-01-01

    A study was undertaken to examine the population structure of viridans group streptococci (VGS) isolated the upper respiratory tract of adult and paediatric patients within the community. VGS are common commensal bacterial inhabitants of the upper respiratory tract and valuable sentinel reporters of underlying antibiotic resistance (AR). Laboratory examination of the colonising VGS species may provide a valuable ecological description of the species isolated from the upper respiratory tract and their antibiotic susceptibility, including an estimation of the AR reservoir in this population. Freshly obtained nasal and oropharyngeal swabs from 84 patients were examined by selective conventional culture on Mitis-Salivarius agar and yielded 363 isolates of VGS. Sequence analyses of the rpnB and 16–23S rRNA ITS genes identified these isolates to belong to 10 species of VGS and included S. anginosus, S. australis, S. constellatus, S. infantis, S. mitis, S. oralis, S. parasanguinis, S. salivarius, S. sanguinis and S. vestibularis. The most frequent VGS organisms isolated was S. salivarius (282/363; 78.0%), followed by S. sanguinis (23/363; 6.3%), S. parasanguinis (21/363; 5.8%), S. mitis (18/363; 5.0%), S. anginosus (5/363; 1.4%), S. vestibularis (5/363; 1.4%), S. australis (3/363; 0.8%), S. oralis (3/363; 0.8%), S. infantis (1/363; 0.3%) and S. constellatus (1/363; 0.3%). All patients examined carried at least one VGS organism, where there were 17 combination patterns of carriage of the 10 species of VGS species isolated, where 54.2%, 37.3%, 7.2% and 1.2% of patients harboured one, two, three and four different VGS species, respectively. Antibiotic susceptibility was determined by standard disk diffusion assay testing against four classes of antibiotics, including the b-lactams [cefotaxime, cefuroxime], the tetracyclines [doxycycline], the fluoroquinolones [levofloxacin] and the macrolides [erythromycin]. Overall, there was no resistance to levofloxacin and cefuroxime

  15. Niemeyer Virus: A New Mimivirus Group A Isolate Harboring a Set of Duplicated Aminoacyl-tRNA Synthetase Genes

    PubMed Central

    Boratto, Paulo V. M.; Arantes, Thalita S.; Silva, Lorena C. F.; Assis, Felipe L.; Kroon, Erna G.; La Scola, Bernard; Abrahão, Jônatas S.

    2015-01-01

    It is well recognized that gene duplication/acquisition is a key factor for molecular evolution, being directly related to the emergence of new genetic variants. The importance of such phenomena can also be expanded to the viral world, with impacts on viral fitness and environmental adaptations. In this work we describe the isolation and characterization of Niemeyer virus, a new mimivirus isolate obtained from water samples of an urban lake in Brazil. Genomic data showed that Niemeyer harbors duplicated copies of three of its four aminoacyl-tRNA synthetase genes (cysteinyl, methionyl, and tyrosyl RS). Gene expression analysis showed that such duplications allowed significantly increased expression of methionyl and tyrosyl aaRS mRNA by Niemeyer in comparison to APMV. Remarkably, phylogenetic data revealed that Niemeyer duplicated gene pairs are different, each one clustering with a different group of mimivirus strains. Taken together, our results raise new questions about the origins and selective pressures involving events of aaRS gain and loss among mimiviruses. PMID:26635738

  16. Chemical history of isolated dwarf galaxies of the Local Group - I. dSphs: Cetus and Tucana

    NASA Astrophysics Data System (ADS)

    Avila-Vergara, N.; Carigi, L.; Hidalgo, S. L.; Durazo, R.

    2016-04-01

    For the first time, we obtain chemical evolution models (CEMs) for Tucana and Cetus, two isolated dwarf spheroidal galaxies of the Local Group. The CEMs have been built from the star formation histories (SFHs) and the metallicity histories, both obtained independently by the Local Cosmology from Isolated Dwarfs (LCID) project from deep colour-magnitude diagrams. Based on our models, we find that the chemical histories were complex and can be divided into different epochs and scenarios. In particular, during 75 per cent of the SFH, the galaxies behaved as closed boxes and, during the remaining 25 per cent, either received a lot of primordial gas by accretion or they lost metals through metal-rich winds. In order to discriminate between these two scenarios, abundances ratios in old stars are needed. At t ˜ 4.5 Gyr, the galaxies lost most of their gas due to a short-strong, well-mixed wind. We obtain very similar CEMs for both galaxies, although Cetus is twice as massive as Tucana. We conclude that the star formation in both galaxies began with only 1.5 per cent of the baryonic mass fraction predicted by Λ cold dark matter.

  17. Isolation and characterization of a unique group of slowly growing mycobacteria: description of Mycobacterium lentiflavum sp. nov.

    PubMed Central

    Springer, B; Wu, W K; Bodmer, T; Haase, G; Pfyffer, G E; Kroppenstedt, R M; Schröder, K H; Emler, S; Kilburn, J O; Kirschner, P; Telenti, A; Coyle, M B; Böttger, E C

    1996-01-01

    A distinct group of slowly growing mycobacteria was identified on the basis of growth characteristics, biochemical and lipid profiles, and nucleic acid analyses. The isolates showed growth at 22 to 37 degrees C, yellow pigmentation, and negative tests for Tween 80 hydrolysis, nicotinic acid, nitrate reductase, and urease; tests for arylsulfatase, pyrazinamidase, and heat-stable catalase were variable. Analysis of cellular fatty acids by gas-liquid chromatography and mycolic acids by thin-layer chromatography and high-performance liquid chromatography indicated a distinctive pattern which was unlike those of other species. Determination of the 16S rRNA gene sequence showed a unique sequence closely related to Mycobacterium simiae and M. genavense. On the basis of DNA homology studies, we suggest that these organisms are representatives of a novel species, for which the name M. lentiflavum sp. nov. is proposed. PMID:8727884

  18. [Antimicrobial activity of cefodizime against clinical isolates].

    PubMed

    Suzuki, Y; Ishihara, R; Ishii, Y; Nakazawa, A; Deguchi, K; Matsumoto, Y; Nishinari, C; Nakane, Y; Fukumoto, T

    1996-10-01

    In order to evaluate antimicrobial activity of cefodizime (CDZM), minimum inhibitory concentrations (MICs) of CDZM and control drugs were determined against clinical isolates collected from nation-wide medical institutions and in our laboratory from September to December of 1992 and from September to December of 1995. The results are summarized as follows: 1. Bacterial species with no or few strains resistant to CDZM included Streptococcus pyogenes, Haemophilus influenzae, Citrobacter koseri, Proteus mirabilis and Neisseria gonorrhoeae. The range of MIC values of CDZM against Klebsiella pneumoniae was spread. Other strains, Streptococcus pneumoniae, Moraxella subgenus Branhamella catarrhalis, Escherichia coli, Citrobacter freundii, Enterobacter spp., Serratia marcescens, Proteus vulgaris, Morganella morganii, Providencia spp., Peptostreptococcus spp. and Bacteroides fragilis group were resistant to cephems including CDZM. 2. The MIC90's of CDZM were 0.05 approximately 3.13 micrograms/ml against Streptococcus spp., H. influenzae, M. (B.) catarrhalis, E. coli, Klebsiella spp., P. mirabilis, N. gonorrhoeae and Peptostreptococcus spp. obtained in 1995 that were frequently found in daily treatment of infections. It appears that the effectiveness of CDZM was still relatively high against community-acquired infections. 3. Among H. influenzae isolates included imipenem (IPM)-resistant and norfloxacin (NFLX)-resistant strains. The MIC-range of CDZM against strains collected in 1995 including IPM-resistant and NFLX-resistant strains was < or = 0.025 approximately 0.1 microgram/ml, and MIC90 against these strains was 0.05 microgram/ml. CDZM showed strong antimicrobial activities against H. influenzae strains resistant to carbapenems and new-quinolones. PMID:8986558

  19. THE PRIMARY STARCH UTILIZATION OPERON IN THE OBLIGATE ANAEROBE BACTEROIDES FRAGILIS IS REGULATED BY CARBON SOURCE AND OXYGEN, AND EXPRESSION IS IMPORTANT FOR SURVIVAL DURING OXIDATIVE STRESS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The obligate anaerobe Bacteroides fragilis is a commensal organism of the human large intestine where it utilizes both dietary and host-derived polysaccharides as a source of carbon and energy. This study describes the characterization of a novel operon, designated oxygen-induced starch utilization...

  20. Adult Male Mice Emit Context-Specific Ultrasonic Vocalizations That Are Modulated by Prior Isolation or Group Rearing Environment

    PubMed Central

    Ey, Elodie; Bellier, Ludovic; Aubin, Thierry; Bourgeron, Thomas; Granon, Sylvie

    2012-01-01

    Social interactions in mice are frequently analysed in genetically modified strains in order to get insight of disorders affecting social interactions such as autism spectrum disorders. Different types of social interactions have been described, mostly between females and pups, and between adult males and females. However, we recently showed that social interactions between adult males could also encompass cognitive and motivational features. During social interactions, rodents emit ultrasonic vocalizations (USVs), but it remains unknown if call types are differently used depending of the context and if they are correlated with motivational state. Here, we recorded the calls of adult C57BL/6J male mice in various behavioral conditions, such as social interaction, novelty exploration and restraint stress. We introduced a modulator for the motivational state by comparing males maintained in isolation and males maintained in groups before the experiments. Male mice uttered USVs in all social and non-social situations, and even in a stressful restraint context. They nevertheless emitted the most important number of calls with the largest diversity of call types in social interactions, particularly when showing a high motivation for social contact. For mice maintained in social isolation, the number of calls recorded was positively correlated with the duration of social contacts, and most calls were uttered during contacts between the two mice. This correlation was not observed in mice maintained in groups. These results open the way for a deeper understanding and characterization of acoustic signals associated with social interactions. They can also help evaluating the role of motivational states in the emission of acoustic signals. PMID:22238608

  1. Unanticipated inhibition of the metallo-beta-lactamase from Bacteroides fragilis by 4-morpholineethanesulfonic acid (MES): a crystallographic study at 1.85-A resolution.

    PubMed

    Fitzgerald, P M; Wu, J K; Toney, J H

    1998-05-12

    As part of a structure-aided effort to design clinically useful inhibitors of metallo-beta-lactamases, the X-ray crystal structure of a complex between the metallo-beta-lactamase from Bacteroides fragilis and 4-morpholinoethanesulfonic acid (MES) has been determined and a model for the structure has been refined to a crystallographic R-factor of 0.151 for data between 10.0- and 1.85-A resolution. Although the binding of MES was an adventitious result of the use of MES as a buffer in the crystallization mixture, MES was subsequently shown to be a competitive inhibitor of the enzyme, with a Ki of 23 +/- 5 mM. MES binds in the same fashion to both of the molecules in the crystallographic asymmetric unit; both direct and solvent-mediated hydrogen bonds to the protein and to the binuclear zinc cluster are observed, involving the oxygens of the sulfonic acid group and the nitrogen of the morpholino ring. In addition, there are hydrophobic interactions between the morpholino ring and residues in the flexible beta-strand of the enzyme between residues 26 and 36. Comparison of this structure with the previously reported unliganded structures of the same enzyme [Concha, N. O., Rasmussen, B. A., Bush, K., and Herzberg, O. (1996) Structure 4, 823-836; Carfi, A., Duée, E., Paul-Soto, R., Galleni, M., Frère, J. -M., and Dideberg, O. (1998) Acta Crystallogr. D54, 47-57] reveals that although the overall conservation of structure in the three different crystal lattices is very high, binding of MES is correlated with a significant change in the conformation of this beta-strand. The flexibility of this beta-strand will be an important consideration in the design of inhibitors of the metallo-beta-lactamases. PMID:9578564

  2. MLVA-16 typing of 295 marine mammal Brucella isolates from different animal and geographic origins identifies 7 major groups within Brucella ceti and Brucella pinnipedialis

    PubMed Central

    2009-01-01

    Background Since 1994, Brucella strains have been isolated from a wide range of marine mammals. They are currently recognized as two new Brucella species, B. pinnipedialis for the pinniped isolates and B. ceti for the cetacean isolates in agreement with host preference and specific phenotypic and molecular markers. In order to investigate the genetic relationships within the marine mammal Brucella isolates and with reference to terrestrial mammal Brucella isolates, we applied in this study the Multiple Loci VNTR (Variable Number of Tandem Repeats) Analysis (MLVA) approach. A previously published assay comprising 16 loci (MLVA-16) that has been shown to be highly relevant and efficient for typing and clustering Brucella strains from animal and human origin was used. Results 294 marine mammal Brucella strains collected in European waters from 173 animals and a human isolate from New Zealand presumably from marine origin were investigated by MLVA-16. Marine mammal Brucella isolates were shown to be different from the recognized terrestrial mammal Brucella species and biovars and corresponded to 3 major related groups, one specific of the B. ceti strains, one of the B. pinnipedialis strains and the last composed of the human isolate. In the B. ceti group, 3 subclusters were identified, distinguishing a cluster of dolphin, minke whale and porpoise isolates and two clusters mostly composed of dolphin isolates. These results were in accordance with published analyses using other phenotypic or molecular approaches, or different panels of VNTR loci. The B. pinnipedialis group could be similarly subdivided in 3 subclusters, one composed exclusively of isolates from hooded seals (Cystophora cristata) and the two others comprising other seal species isolates. Conclusion The clustering analysis of a large collection of marine mammal Brucella isolates from European waters significantly strengthens the current view of the population structure of these two species, and their

  3. Survey of the bp/tee genes from clinical group A streptococcus isolates in New Zealand - implications for vaccine development.

    PubMed

    Steemson, John D; Moreland, Nicole J; Williamson, Deborah; Morgan, Julie; Carter, Philip E; Proft, Thomas

    2014-12-01

    Group A streptococcus (GAS) is responsible for a wide range of diseases ranging from superficial infections, such as pharyngitis and impetigo, to life-threatening diseases, such as toxic shock syndrome and acute rheumatic fever (ARF). GAS pili are hair-like extensions protruding from the cell surface and consist of highly immunogenic structural proteins: the backbone pilin (BP) and one or two accessory pilins (AP1 and AP2). The protease-resistant BP builds the pilus shaft and has been recognized as the T-antigen, which forms the basis of a major serological typing scheme that is often used as a supplement to M typing. A previous sequence analysis of the bp gene (tee gene) in 39 GAS isolates revealed 15 different bp/tee types. In this study, we sequenced the bp/tee gene from 100 GAS isolates obtained from patients with pharyngitis, ARF or invasive disease in New Zealand. We found 20 new bp/tee alleles and four new bp/tee types/subtypes. No association between bp/tee type and clinical outcome was observed. We confirmed earlier reports that the emm type and tee type are associated strongly, but we also found exceptions, where multiple tee types could be found in certain M/emm type strains, such as M/emm89. We also reported, for the first time, the existence of a chimeric bp/tee allele, which was assigned into a new subclade (bp/tee3.1). A strong sequence conservation of the bp/tee gene was observed within the individual bp/tee types/subtypes (>97 % sequence identity), as well as between historical and contemporary New Zealand and international GAS strains. This temporal and geographical sequence stability provided further evidence for the potential use of the BP/T-antigen as a vaccine target. PMID:25190737

  4. Alcohol from whey permeate: strain selection, temperature, and medium optimization. [Candida pseudotropicalis, Kluyveromyces fragilis, and K. lactis

    SciTech Connect

    Vienne, P.; Von Stockar, U.

    1983-01-01

    A comparative study of shaken flask cultures of some yeast strains capable of fermenting lactose showed no significant differences in alcohol yield among the four best strains. Use of whey permeate concentrated three times did not affect the yields. An optimal growth temperature of 38/sup 0/C was determined for K. fragilis NRRL 665. Elemental analysis of both the permeate and the dry cell mass of two strains indicated the possibility of a stoichiometric limitation by nitrogen. Batch cultures in laboratory fermentors confirmed this finding and revealed in addition the presence of a limitation due to growth factors. Both types of limitations could be overcome by adding yeast extract. The maximum productivity of continuous cultures could thus be improved to 5.1 g/l-h. The maximum specific growth rate was of the order of 0.310 h/sup -1/. 15 references, 10 figures, 9 tables.

  5. The Complete Genome Phylogeny of Geographically Distinct Dengue Virus Serotype 2 Isolates (1944-2013) Supports Further Groupings within the Cosmopolitan Genotype

    PubMed Central

    Ali, Akhtar; Ali, Ijaz

    2015-01-01

    Dengue virus serotype 2 (DENV-2) isolates have been implicated in deadly outbreaks of dengue fever (DF) and dengue hemorrhagic fever (DHF) in several regions of the world. Phylogenetic analysis of DENV-2 isolates collected from particular countries has been performed using partial or individual genes but only a few studies have examined complete whole-genome sequences collected worldwide. Herein, 50 complete genome sequences of DENV-2 isolates, reported over the past 70 years from 19 different countries, were downloaded from GenBank. Phylogenetic analysis was conducted and evolutionary distances of the 50 DENV-2 isolates were determined using maximum likelihood (ML) trees or Bayesian phylogenetic analysis created from complete genome nucleotide (nt) and amino acid (aa) sequences or individual gene sequences. The results showed that all DENV-2 isolates fell into seven main groups containing five previously defined genotypes. A Cosmopolitan genotype showed further division into three groups (C-I, C-II, and C-III) with the C-I group containing two subgroups (C-IA and C-IB). Comparison of the aa sequences showed specific mutations among the various groups of DENV-2 isolates. A maximum number of aa mutations was observed in the NS5 gene, followed by the NS2A, NS3 and NS1 genes, while the smallest number of aa substitutions was recorded in the capsid gene, followed by the PrM/M, NS4A, and NS4B genes. Maximum evolutionary distances were found in the NS2A gene, followed by the NS4A and NS4B genes. Based on these results, we propose that genotyping of DENV-2 isolates in future studies should be performed on entire genome sequences in order to gain a complete understanding of the evolution of various isolates reported from different geographical locations around the world. PMID:26414178

  6. Fluoroquinolone Resistance Mutations in the parC, parE, and gyrA Genes of Clinical Isolates of Viridans Group Streptococci

    PubMed Central

    González, Irene; Georgiou, Marios; Alcaide, Fernando; Balas, Delia; Liñares, Josefina; de la Campa, Adela G.

    1998-01-01

    The nucleotide sequences of the quinolone resistance-determining regions (QRDRs) of the parC and gyrA genes from seven ciprofloxacin-resistant (Cpr) isolates of viridans group streptococci (two high-level Cpr Streptococcus oralis and five low-level Cpr Streptococcus mitis isolates) were determined and compared with those obtained from susceptible isolates. The nucleotide sequences of the QRDRs of the parE and gyrB genes from the five low-level Cpr S. mitis isolates and from the NCTC 12261 type strain were also analyzed. Four of these low-level Cpr isolates had changes affecting the subunits of DNA topoisomerase IV: three in Ser-79 (to Phe or Ile) of ParC and one in ParE at a position not previously described to be involved in quinolone resistance (Pro-424). One isolate did not show any mutation. The two high-level Cpr S. oralis isolates showed mutations affecting equivalent residue positions of ParC and GyrA, namely, Ser-79 to Phe and Ser-81 to Phe or Tyr, respectively. The parC mutations were able to transform Streptococcus pneumoniae to ciprofloxacin resistance, while the gyrA mutations transformed S. pneumoniae only when mutations in parC were present. These results suggest that DNA topoisomerase IV is a primary target of ciprofloxacin in viridans group streptococci, DNA gyrase being a secondary target. PMID:9797205

  7. Tofla virus: A newly identified Nairovirus of the Crimean-Congo hemorrhagic fever group isolated from ticks in Japan

    PubMed Central

    Shimada, Satoshi; Aoki, Kotaro; Nabeshima, Takeshi; Fuxun, Yu; Kurosaki, Yohei; Shiogama, Kazuya; Onouchi, Takanori; Sakaguchi, Miako; Fuchigami, Takeshi; Ono, Hokuto; Nishi, Kodai; Posadas-Herrera, Guillermo; Uchida, Leo; Takamatsu, Yuki; Yasuda, Jiro; Tsutsumi, Yutaka; Fujita, Hiromi; Morita, Kouichi; Hayasaka, Daisuke

    2016-01-01

    Ixodid ticks transmit several important viral pathogens. We isolated a new virus (Tofla virus: TFLV) from Heamaphysalis flava and Heamaphysalis formsensis in Japan. The full-genome sequences revealed that TFLV belonged to the genus Nairovirus, family Bunyaviridae. Phylogenetic analyses and neutralization tests suggested that TFLV is closely related to the Hazara virus and that it is classified into the Crimean-Congo hemorrhagic fever group. TFLV caused lethal infection in IFNAR KO mice. The TFLV-infected mice exhibited a gastrointestinal disorder, and positron emission tomography-computed tomography images showed a significant uptake of 18F-fluorodeoxyglucose in the intestinal tract. TFLV was able to infect and propagate in cultured cells of African green monkey-derived Vero E6 cells and human-derived SK-N-SH, T98-G and HEK-293 cells. Although TFLV infections in humans and animals are currently unknown, our findings may provide clues to understand the potential infectivity and to develop of pre-emptive countermeasures against this new tick-borne Nairovirus. PMID:26863911

  8. Tofla virus: A newly identified Nairovirus of the Crimean-Congo hemorrhagic fever group isolated from ticks in Japan.

    PubMed

    Shimada, Satoshi; Aoki, Kotaro; Nabeshima, Takeshi; Fuxun, Yu; Kurosaki, Yohei; Shiogama, Kazuya; Onouchi, Takanori; Sakaguchi, Miako; Fuchigami, Takeshi; Ono, Hokuto; Nishi, Kodai; Posadas-Herrera, Guillermo; Uchida, Leo; Takamatsu, Yuki; Yasuda, Jiro; Tsutsumi, Yutaka; Fujita, Hiromi; Morita, Kouichi; Hayasaka, Daisuke

    2016-01-01

    Ixodid ticks transmit several important viral pathogens. We isolated a new virus (Tofla virus: TFLV) from Heamaphysalis flava and Heamaphysalis formsensis in Japan. The full-genome sequences revealed that TFLV belonged to the genus Nairovirus, family Bunyaviridae. Phylogenetic analyses and neutralization tests suggested that TFLV is closely related to the Hazara virus and that it is classified into the Crimean-Congo hemorrhagic fever group. TFLV caused lethal infection in IFNAR KO mice. The TFLV-infected mice exhibited a gastrointestinal disorder, and positron emission tomography-computed tomography images showed a significant uptake of (18)F-fluorodeoxyglucose in the intestinal tract. TFLV was able to infect and propagate in cultured cells of African green monkey-derived Vero E6 cells and human-derived SK-N-SH, T98-G and HEK-293 cells. Although TFLV infections in humans and animals are currently unknown, our findings may provide clues to understand the potential infectivity and to develop of pre-emptive countermeasures against this new tick-borne Nairovirus. PMID:26863911

  9. [Genetic Characteristics of Coxsackievirus Group A Type 4 Isolated from Patients with Acute Flaccid Paralysis in Shaanxi, China].

    PubMed

    Wang, Dongyan; Xu, Yi; Zhang, Yong; Zhu, Shuangli; Si, Yuan; Yan, Dongmei; Zhu, Hui; Yang, Qian; Ji, Tianjiao; Xu, Wenbo

    2016-03-01

    We analyzed the genetic characteristics of coxsackievirus A4 (CV-A4) based on the entire VP1 coding region. Samples were isolated from patients with acute flaccid paralysis (AFP) in Shaanxi, China from 2006 to 2010. We wished to ascertain the predominant genotype and the relationship between CV-A4 infection and AFP. Sixty-eight non-polio enteroviruses were inoculated onto RD cells (to increase the virus titer) and molecular typing was undertaken. The entire VP1 coding region was amplified. Percentage of CV-A4 was 10.3% (7/68). Analyses of genetic identify and creation of phylogenetic trees revealed that CV-A4 could be classified into A, B and C genotypes. Seven CV-A4 strains from Shaanxi and other CV-A4 strains from China formed an independent evolution lineage located in group 4 and belonged to the C2 sub-genotype. These data suggested that CV-A4 strains of sub-genotype C2 were the predominant genotypes in China. These strains co-evolved and co-circulated with those from other provinces in China, so continued monitoring of CV-A4 (by clinical and genetic surveillance) should be enhanced. PMID:27396156

  10. Diversity and biofilm-production ability among isolates of Escherichia coli phylogroup D belonging to ST69, ST393 and ST405 clonal groups

    PubMed Central

    2013-01-01

    Background Phylogenetic group D Escherichia coli clones (ST69, ST393, ST405) are increasingly reported as multidrug resistant strains causing extra-intestinal infections. We aim to characterize inter- and intraclonal diversity of a broad sample (isolates from different geographic locations and origins with variable antibiotic resistance profiles, 1980-2010) and their ability to adhere and form biofilm by both a modified quantitative biofilm producing assay and Field Emission Scanning Electron Microscopy (FESEM). Results High virulence scores were observed among ST69 (median 14/range 9–15) and ST393 (median 14/range 8–15) clones, particularly enriched in pap alleles, iha, kpsMTII-K5 and ompT, in contrast with ST405 (median 6/range 2–14) isolates, exhibiting frequently fyuA, malX and traT. All ST69 and ST393 and only two ST405 isolates were classified as ExPEC. Biofilm production was detected in two non-clinical ST69 and three ST393 isolates from different origins showing variable virulence profiles. Within each clonal group, and despite the high diversity of PFGE-types observed, isolates from different countries and recovered over large periods of time were clustered in a few groups sharing common virulence gene profiles among ST69 (n = 10 isolates) and ST393 (n = 9 isolates) (fimH-iha-iutA-kpsMTII-K5-(traT)-sat-(ompT)-papA-papEF-papGII-papC) or ST405 (n = 6 isolates) (fimH-traT-fyuA-malX). Conclusions This study highlights the circulation of highly transmissible ST69, ST393 and ST405 variants among different settings. Biofilm production seems not to be directly correlated with their epidemiological success. PMID:23800205