for Journals by Title or ISSN
for Articles by Keywords
  Subjects -> BIOLOGY (Total: 2896 journals)
    - BIOCHEMISTRY (215 journals)
    - BIOENGINEERING (97 journals)
    - BIOLOGY (1404 journals)
    - BIOPHYSICS (44 journals)
    - BIOTECHNOLOGY (190 journals)
    - BOTANY (221 journals)
    - CYTOLOGY AND HISTOLOGY (26 journals)
    - ENTOMOLOGY (60 journals)
    - GENETICS (150 journals)
    - MICROBIOLOGY (243 journals)
    - MICROSCOPY (11 journals)
    - ORNITHOLOGY (29 journals)
    - PHYSIOLOGY (65 journals)
    - ZOOLOGY (141 journals)

BIOLOGY (1404 journals)            First | 1 2 3 4 5 6 7 8 | Last

Developmental Biology Journal     Open Access  
Developmental Cell     Full-text available via subscription   (Followers: 33)
Developmental Dynamics     Hybrid Journal   (Followers: 2)
Developmental Neurobiology     Hybrid Journal   (Followers: 4)
Developments in Marine Biology     Full-text available via subscription   (Followers: 9)
Dhaka University Journal of Biological Sciences     Open Access  
Diatom Research     Hybrid Journal  
Differentiation     Hybrid Journal   (Followers: 1)
Disease Models and Mechanisms     Open Access   (Followers: 1)
DNA and Cell Biology     Hybrid Journal   (Followers: 4)
DNA Repair     Hybrid Journal   (Followers: 2)
DNA Research     Open Access   (Followers: 3)
Doklady Physics     Hybrid Journal   (Followers: 1)
Drug Discovery Today     Full-text available via subscription   (Followers: 129)
Drug Discovery Today: Disease Mechanisms     Full-text available via subscription   (Followers: 7)
Drug Discovery Today: Disease Models     Full-text available via subscription   (Followers: 6)
Drug Discovery Today: Technologies     Full-text available via subscription   (Followers: 11)
Drug Discovery Today: Therapeutic Strategies     Full-text available via subscription   (Followers: 10)
Drug Resistance Updates     Hybrid Journal   (Followers: 4)
e-Neuroforum     Hybrid Journal  
Ecohydrology & Hydrobiology     Full-text available via subscription   (Followers: 3)
Ecología en Bolivia     Open Access  
Ecological Engineering     Hybrid Journal   (Followers: 3)
Ecology and Society     Open Access   (Followers: 31)
Ecology Letters     Hybrid Journal   (Followers: 203)
Economics & Human Biology     Hybrid Journal  
Ecoprint : An International Journal of Ecology     Open Access   (Followers: 2)
Ecoscience     Full-text available via subscription   (Followers: 3)
Educational Technology Research and Development     Partially Free   (Followers: 106)
Egyptian Journal of Basic and Applied Sciences     Open Access  
Egyptian Journal of Biology     Open Access  
Egyptian Journal of Histology     Partially Free   (Followers: 1)
Egyptian Journal of Natural History     Open Access   (Followers: 1)
EJNMMI Research     Open Access   (Followers: 1)
Ekológia (Bratislava) : The Journal of Institute of Landscape Ecology of Slovak Academy of Sciences     Open Access  
el-Hayah     Open Access   (Followers: 1)
Electromagnetic Biology and Medicine     Hybrid Journal   (Followers: 1)
eLife     Open Access   (Followers: 29)
Embo Molecular Medicine     Open Access   (Followers: 4)
EMBO reports     Full-text available via subscription   (Followers: 20)
Emotion Review     Hybrid Journal   (Followers: 13)
Endocrine Connections     Open Access   (Followers: 4)
Engineering & Technology     Hybrid Journal   (Followers: 19)
Engineering Economist, The     Hybrid Journal   (Followers: 3)
Engineering in Life Sciences     Hybrid Journal   (Followers: 4)
Engineering Optimization     Hybrid Journal   (Followers: 8)
Ensaios e Ciência: Ciências Biológicas, Agrárias e da Saúde     Open Access  
Environmental Biology of Fishes     Hybrid Journal   (Followers: 5)
Environmental Biosafety Research     Hybrid Journal   (Followers: 1)
Environmental Microbiology     Hybrid Journal   (Followers: 14)
Environmental Science & Technology     Full-text available via subscription   (Followers: 176)
Enzyme and Microbial Technology     Hybrid Journal   (Followers: 6)
Enzyme Research     Open Access   (Followers: 4)
Epidemiology & Infection     Hybrid Journal   (Followers: 14)
Epigenetics in Cancer     Open Access   (Followers: 1)
EPMA Journal     Open Access  
ESHRE Monographs     Hybrid Journal  
Ethiopian Journal of Biological Sciences     Open Access   (Followers: 5)
Ethnobiology and Conservation     Open Access   (Followers: 2)
Ethnobotany Research & Applications : a journal of plants, people and applied research     Open Access   (Followers: 7)
Ethology     Hybrid Journal   (Followers: 6)
Ethology Ecology & Evolution     Hybrid Journal   (Followers: 14)
Eukaryotic Cell     Full-text available via subscription   (Followers: 7)
EuPA Open Proteomics     Open Access   (Followers: 2)
EURASIP Journal on Bioinformatics and Systems Biology     Open Access   (Followers: 7)
European Journal of Cell Biology     Hybrid Journal   (Followers: 3)
European Journal of Neuroscience     Hybrid Journal   (Followers: 29)
European Journal of Phycology     Hybrid Journal   (Followers: 5)
European Journal of Protistology     Hybrid Journal   (Followers: 3)
European Journal of Soil Biology     Hybrid Journal   (Followers: 2)
European Online Journal of Natural and Social Sciences     Open Access   (Followers: 14)
European Scientific Journal     Open Access   (Followers: 2)
Evidência - Ciência e Biotecnologia - Interdisciplinar     Open Access  
EvoDevo     Open Access   (Followers: 1)
Evolução e Conservação da Biodiversidade     Open Access  
Evolution     Partially Free   (Followers: 133)
Evolution and Human Behavior     Hybrid Journal   (Followers: 13)
Evolutionary Applications     Open Access   (Followers: 3)
Evolutionary Bioinformatics     Open Access   (Followers: 15)
Evolutionary Biology     Hybrid Journal   (Followers: 18)
Evolutionary Computation     Hybrid Journal   (Followers: 10)
Experimental & Molecular Medicine     Open Access   (Followers: 2)
Experimental and Applied Acarology     Hybrid Journal   (Followers: 1)
Experimental Cell Research     Hybrid Journal   (Followers: 4)
Expert Opinion on Biological Therapy     Hybrid Journal   (Followers: 8)
Expert Opinion on Environmental Biology     Hybrid Journal  
Expert Review of Proteomics     Hybrid Journal   (Followers: 2)
Extreme Life, Biospeology & Astrobiology - International Journal of the Bioflux Society     Full-text available via subscription   (Followers: 5)
Extremophiles     Hybrid Journal   (Followers: 1)
F1000Research     Open Access   (Followers: 4)
Facta Universitatis, Series : Medicine and Biology     Open Access  
Familial Cancer     Hybrid Journal   (Followers: 1)
Fatigue & Fracture of Engineering Materials and Structures     Hybrid Journal   (Followers: 14)
Fauna Norvegica     Open Access  
Fauna of New Zealand     Open Access  
Febs Journal     Hybrid Journal   (Followers: 10)
Feddes Repertorium     Hybrid Journal  
Fems Yeast Research     Hybrid Journal   (Followers: 12)
Field Mycology     Full-text available via subscription   (Followers: 2)
Fish & Shellfish Immunology     Hybrid Journal   (Followers: 11)

  First | 1 2 3 4 5 6 7 8 | Last

Journal Cover   Anaerobe
  [SJR: 1.09]   [H-I: 44]   [3 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1075-9964 - ISSN (Online) 1095-8274
   Published by Elsevier Homepage  [2801 journals]
  • Routine detection of Clostridium difficile in Western Australia
    • Abstract: Publication date: Available online 22 November 2015
      Author(s): Deirdre A. Collins, Thomas V. Riley
      Despite increasing infection rates, Clostridium difficile is not currently routinely tested for in all diarrhoeal faecal specimens in Australia. In July 2014, all diarrhoeal specimens submitted to a diagnostic laboratory in Western Australia were surveyed to determine the true prevalence of C. difficile. In total, 1010 diarrhoeal non-duplicate faecal specimens were received during the month. Testing for C. difficile was requested, or the criteria for a C. difficile investigation were met, for 678 specimens which were investigated by PCR for the tcdB gene using the BD MAX platform, followed by toxigenic culture on PCR positive samples. The remaining 332 specimens, with either no C. difficile test request or the criteria for a C. difficile investigation were not met, were examined by toxigenic culture. All isolates were PCR ribotyped. C. difficile was the most commonly detected diarrhoeal pathogen among all specimens. The overall prevalence of C. difficile in all 1010 specimens was 6.4%; 7.2% in the routinely tested group, and 4.8% in the non-requested group. The proportion of non-requested positive detections among all cases was 24.6%. Community-onset infection was present in 50.8% of all cases. The median age of all CDI cases was 60.0 years and the age range in CDI patients in the routine group was 0.6-96.6 years (median 72.7 years), compared to 0.2-2.3 years (median 0.8 years) in the non-requested group. The most common ribotype (RT) found was RT 014/020 (34.1% in the routine group, 43.8% in the non-requested group), followed by RTs 002, 056, 005 and 018. While the routine testing group and the non-requested group differed markedly in age and patient classification, C. difficile was the most common cause of diarrhoea in hospitals and the community in Western Australia. The significance of finding C. difficile in the community paediatric population requires further study.

      PubDate: 2015-11-24T23:24:19Z
  • Microbiological diagnosis of Eggerthella lenta blood culture isolates in a
           Swedish tertiary hospital: Rapid identification and antimicrobial
           susceptibility profile
    • Abstract: Publication date: Available online 22 November 2015
      Author(s): Karin Liderot, Paul Ratcliffe, Petra Lüthje, Ellinor Tidholm, Volkan Özenci
      Eggerthella lenta is a Gram-positive anaerobic bacillus. Improved diagnostics and increased awareness of rare pathogens have revealed its potential to cause serious invasive infections. In this study, 18 clinical E. lenta isolates derived from positive blood cultures were included. Underlying problems of the patients were in the majority of cases related to the gastrointestinal tract. The performance of two MALDI-TOF MS systems, i.e. Bruker and Vitek MS, in identification of E. lenta was analyzed. In addition, the minimal inhibitory concentrations for clinically relevant antimicrobial agents were determined by routine procedures using E-test. 17 of the 18 E. lenta isolates investigated in this study were correctly identified to species level by the Bruker MS system, while the Vitek MS system identified all 18 isolates. Antimicrobial sensitivity towards the tested agents was in general good. However, high resistance rates were observed for penicillin G and piperacillin-tazobactam based on EUCAST breakpoints.

      PubDate: 2015-11-24T23:24:19Z
  • Missing microbes – a must-read written by an influential pioneer
    • Abstract: Publication date: Available online 14 November 2015
      Author(s): Lars Engstrand

      PubDate: 2015-11-20T23:07:39Z
  • Comparison of vaginal microbial community structure in healthy and
           endometritis dairy cows by PCR-DGGE and Real-time PCR
    • Abstract: Publication date: Available online 10 November 2015
      Author(s): Jun Wang, Chengtao Sun, Chang Liu, Yujiang Yang, Wenfa Lu
      The normal vaginal microflora provides protection against infections of the reproductive tract. Previous studies have focused on the isolation and screening of probiotic strains from the vagina of cows; however, the vaginal microflora of postpartum cows is poorly characterized. The present study was conducted to evaluate and characterize the vaginal microflora of healthy postpartum cows in relation to postpartum cows with endometritis by using PCR followed by denaturing gradient gel electrophoresis (PCR-DGGE) and Real-time PCR. The study population comprised 5 healthy cows and 5 cows with endometritis. The results indicated that the vaginal bacterial microflora of healthy postpartum cows was dominated by Lactobacillus sakei subsp. and Weissella koreensis, while there were no dominant bacterial species in the vaginal microflora of postpartum cows with endometritis. Common microorganisms such as Bacteroides spp., Fusobacterium spp., Enterococcus spp., Prevotella spp., Clostridium perfringens strains, and Escherichia coli were detected in both groups of cows by Real-time PCR. The bacterial diversity in the vagina of cows with endometritis was significantly higher than that in healthy cows. The results indicated that the vaginal microflora of cows with endometritis was more diverse and lacked dominant bacterial species as compared to that of the healthy cows, suggesting that disruption of the normal vaginal microflora may contribute to the onset of endometritis. This microbial community analysis provided information that might be used to develop probiotics to treat endometritis in cows; however, further investigation is needed.

      PubDate: 2015-11-12T22:21:15Z
  • A Whole New Ball Game: Stem Cell-Derived Epithelia in the Study of
           Host-Microbe Interactions
    • Abstract: Publication date: Available online 5 November 2015
      Author(s): Jhansi L. Leslie, Vincent B. Young
      Recent advances in developmental and stem cell biology have resulted in techniques that enable the generation and maintenance of complex epithelium in vitro. While these models have been utilized to study host development and disease, a renewed appreciation of host-microbe interactions has sparked interest in employing these new techniques to study microbes at the epithelial interface. Here we review the current advances in host-microbe interactions that have resulted from experiments using these complex epithelia. Furthermore we highlight aspects of these techniques that warrant further development to facilitate these the study of host-microbe interactions.

      PubDate: 2015-11-08T22:00:42Z
  • Diagnostic testing for Clostridium difficile in Italian microbiological
    • Abstract: Publication date: Available online 7 November 2015
      Author(s): Patrizia Spigaglia, Fabrizio Barbanti, Matteo Morandi, Maria Luisa Moro, Paola Mastrantonio
      A laboratory diagnosis survey of Clostridium difficile infection (CDI) was performed in Italy in 2012-2013. Questionnaires from 278 healthcare settings from 15 regions of Italy were collected and analysed. Eighty seven percent of the laboratories declared to routinely perform CDI diagnosis, 99% of them only after the clinician’s request. Among the 216 laboratories providing information on the size of the hospitals in which they were located, 65 had more than 500 beds (large hospitals), while 151 had less than 500 beds (small hospitals). The average percentage of positive tests for C. difficile toxins was 12.2%. Almost half of the laboratories (42%) used immunoenzymatic assay (EIA) for Tox A/B as a stand-alone method, while only 34% used an algorithm for CDI as indicated by the European guidelines. A low percentage of laboratories performed molecular assays or C. difficile culture, 25% and 29%, respectively. Most laboratories (161/278) declared to type C. difficile strains, the majority in collaboration with a reference laboratory. Among the 103 C. difficile clinical isolates collected during the study, 31 different PCR-ribotypes were identified. PCR-ribotype 356/607 (27%) was predominant, followed by 018 (12%). These two PCR-ribotypes show 87.5% of similarity in ribotyping profile. PCR-ribotypes 027 and 078 represented 8% and 4% of the strains, respectively. Four PCR-ribotypes (027, 033, 078 and 126) were positive for the binary toxin CDT. In particular, PCR-ribotype 033 produces only CDT, and it has recently been associated with symptomatic cases. The majority of strains were multidrug resistant. In particular, all strains PCR-ribotypes 356/607 and 018 were resistant to moxifloxacin, rifampicin, erythromycin and clindamycin. The results obtained highlight the need to raise awareness to the microbiological diagnosis of CDI among clinicians and to implement and harmonize diagnostic methods for CDI in Italian laboratories in the perspective of a future national surveillance.

      PubDate: 2015-11-08T22:00:42Z
  • Inactivation of Clostridium difficile spores by microwave irradiation
    • Abstract: Publication date: Available online 4 November 2015
      Author(s): Suvash Chandra Ojha, Surang Chankhamhaengdecha, Sombat Singhakaew, Puey Ounjai, Tavan Janvilisri
      Spores are a potent agent for C. difficile transmission. Therefore, factors inhibiting spores have been of continued interest. In the present study, we investigated the influence of microwave irradiation in addition to conductive heating for C. difficile spore inactivation in aqueous suspension. The spores of 15 C. difficile isolates from different host origins were exposed to conductive heating and microwave irradiation. The complete inhibition of spore viability at 107 CFU/ml was encountered following microwave treatment at 800W for 60 seconds, but was not observed in the conductive-heated spores at the same time-temperature exposure. The distinct patterns of ultrastructural alterations following microwave and conductive heat treatment were observed and the degree of damages by microwave was in the exposure time-dependent manner. Microwave would therefore be a simple and time-efficient tool to inactivate C. difficile spores, thus reducing the risk of C. difficile transmission.
      Graphical abstract image

      PubDate: 2015-11-05T15:40:39Z
  • Livers provide a reliable matrix for real-time PCR confirmation of avian
    • Abstract: Publication date: Available online 3 November 2015
      Author(s): Caroline Le Maréchal, Valentine Ballan, Sandra Rouxel, Marie-Hélène Bayon-Auboyer, Marie-Agnès Baudouard, Hervé Morvan, Emmanuelle Houard, Typhaine Poëzevara, Rozenn Souillard, Cédric Woudstra, Sophie Le Bouquin, Patrick Fach, Marianne Chemaly
      Diagnosis of avian botulism is based on clinical symptoms, which are indicative but not specific. Laboratory investigations are therefore required to confirm clinical suspicions and establish a definitive diagnosis. Real-time PCR methods have recently been developed for the detection of Clostridium botulinum group III producing type C, D, C/D or D/C toxins. However, no study has been conducted to determine which types of matrices should be analyzed for laboratory confirmation using this approach. This study reports on the comparison of different matrices (pooled intestinal contents, livers, spleens and cloacal swabs) for PCR detection of C. botulinum. Between 2013 and 2015, 63 avian botulism suspicions were tested and 37 were confirmed as botulism. Analysis of livers using real-time PCR after enrichment led to the confirmation of 97% of the botulism outbreaks. Using the same method, spleens led to the confirmation of 90 % of botulism outbreaks, cloacal swabs of 93 % and pooled intestinal contents of 46%. Liver appears to be the most reliable type of matrix for laboratory confirmation using real-time PCR analysis.

      PubDate: 2015-11-05T15:40:39Z
  • Complete Genome Sequences and Analysis of the Fusobacterium nucleatum
           subspecies animalis 7-1 Bacteriophage ɸFunu1 and ɸFunu2
    • Abstract: Publication date: Available online 3 November 2015
      Author(s): Kyla Cochrane, Abigail Manson McGuire, Margaret E. Priest, Amr Abouelleil, Gustavo C. Cerqueira, Reggie Lo, Ashlee M. Earl, Emma Allen-Vercoe
      Fusobacterium nucleatum is a strictly anaerobic, Gram negative bacterial species that has been associated with dental infections, pre-term labour, appendicitis, inflammatory bowel disease, and, more recently, colorectal cancer. The species is unusual in its phenotypic and genotypic heterogeneity, with some strains demonstrating a more virulent phenotype than others; however, as yet the genetic basis for these differences is not understood. Bacteriophage are known to contribute to the virulence phenotype of several bacterial species. In this work, we set out to characterize the bacteriophage associated with F. nucleatum subsp. animalis strain 7-1, a highly invasive isolate from the human gastrointestinal tract. As well, we used computational approaches to predict and compare bacteriophage signatures across available sequenced Fusobacterium nucleatum genomes.

      PubDate: 2015-11-05T15:40:39Z
  • Virulence of Aggregatibacter actinomycetemcomitans serotypes and DGGE
           subtypes isolated from chronic adult periodontitis in Thailand
    • Abstract: Publication date: Available online 31 October 2015
      Author(s): Nuntiya Pahumunto, Praphansri Ruangsri, Mutita Wongsuwanlert, Supatcharin Piwat, Gunnar Dahlen, Rawee Teanpaisan
      A high proportion of non-serotypeable isolates of Aggregatibacter actinomycetemcomitans among Thai periodontitis cases has been previously reported. The aim of this study was to investigate the expression of leukotoxin and toxicity, cytolethal distending toxin (Cdts), and internalization and the killing effect on fibroblasts by A. actinomycetemcomitans subtypes from Thai chronic periodontitis cases. A total of 96 A. actinomycetemcomitans strains from 37 periodontitis cases, previously serotyped with PCR and subtyped with DGGE, were examined for the presence of the ltx gene and cdt genes (cdtBC), and tested for leukotoxin expression, leukotoxicity, internalization, and apoptosis of fibroblast cells. The ltx gene was present in all isolates, while 84.4% showed the cdtBC gene. Two strains with a JP2-like ltx gene with a deletion of 530 bp in the promoter region, serotyped as c, showed virulence of similar magnitude to the JP2 strain. Furthermore, a higher virulence was found in the two non-serotypeable DGGE subtypes, NS1 and NS2, compared with the serotypeable strains (serotype a-f, serotype b and d were absent). Generally, the virulence of strains obtained from deep periodontal pockets was higher than those isolated from shallow non-bleeding pockets. A. actinomycetemcomitans subtypes isolated from adult Thais with chronic periodontitis showed a highly variable virulence, leukotoxin expression, leukotoxicity, internalization and apoptosis of fibroblast, and are regulated both genetically and environmentally.

      PubDate: 2015-11-01T08:30:15Z
  • Evidence for a natural humoral response in dairy cattle affected by
           persistent botulism sustained by non-chimeric type C strains
    • Abstract: Publication date: December 2015
      Source:Anaerobe, Volume 36
      Author(s): Luca Bano, Ilenia Drigo, Elena Tonon, Giacomo Berto, Alexander Tavella, Cedric Woudstra, Katia Capello, Fabrizio Agnoletti
      Bovine botulism is a sporadic acute disease that usually causes catastrophic losses in the herds. The unusual clinical evolution of a persistent mild outbreak in a dairy herd, prompted us to characterize the neurotoxin gene profile of the strain involved and to evaluate whether seroconversion had occurred. Diagnosis was based on mild classical symptoms and was supported by PCR and bacteriological findings, which revealed the involvement of a non-mosaic type C strain. An in-house ELISA was developed to detect antibodies to botulinum neurotoxin type C and its performance was evaluated in a vaccination study. Fifty days after the index case, fecal and serum samples were collected from the 14 animals of the herd and screened for Clostridium botulinum and anti-botulinum neurotoxin antibodies type C, respectively. The in-house developed ELISA was also used to test 100 sera samples randomly collected from 20 herds. Strong ELISA reactions were observed in 3 convalescent and 5 asymptomatic animals involved in the studied outbreak. The ELISA-positive cows all tested positive for non-mosaic C. botulinum type C in the feces and the same strain was also detected in the alfalfa hay, suspected to be the carrier source. Ten out of the 100 randomly collected sera tested positive for anti-botulinum neurotoxin type C antibodies: 7 had borderline values and 3 from the same herd showed titers three times higher than the cut-off. We concluded that type C botulism in cattle may occur with variable severity and that prolonged exposure to sublethal doses of botulinum neurotoxin C may occur, resulting in detectable antibodies.

      PubDate: 2015-11-01T08:30:15Z
  • Outcome of relapsing Clostridium difficile infections do not correlate
           with virulence-, spore- and vegetative cell-associated phenotypes
    • Abstract: Publication date: December 2015
      Source:Anaerobe, Volume 36
      Author(s): Ángela Plaza-Garrido, Camila Miranda-Cárdenas, Pablo Castro-Córdova, Valeria Olguín-Araneda, Glenda Cofré-Araneda, Cristian Hernández-Rocha, Robert Carman, Patricio Ibáñez, Warren N. Fawley, Mark H. Wilcox, Fernando Gil, Iván L. Calderón, Juan A. Fuentes, Ana María Guzmán-Durán, Manuel Alvarez-Lobos, Daniel Paredes-Sabja
      One of the main clinical challenges of Clostridium difficile infections (CDI) is the high rate of relapse episodes. The main determinants involved in relapse of CDI include the presence of antibiotic-resistant C. difficile spores in the colonic environment and a permanent state of dysbiosis of the microbiota caused by antibiotic therapy. A possible scenario is that phenotypes related to the persistence of C. difficile spores might contribute to relapsing infections. In this study, 8 C. difficile isolates recovered from 4 cases with relapsing infection, and 9 isolates recovered from single infection cases were analyzed for PCR ribotyping and the presence of tcdA, tcdB and cdtAB genes. Factors associated to spore persistence, sporulation, spore adherence and biofilm formation and sporulation during biofilm formation were characterized. We also evaluated motility and cytotoxicity. However, we observed no significant difference in the analyzed phenotypes among the different clinical outcomes, most likely due to the high variability observed among strains within clinical backgrounds in each phenotype and the small sample size. It is noteworthy that C. difficile spores adhered to similar extents to undifferentiated and differentiated Caco-2 cells. By contrast, spores of all clinical isolates tested had increased germination efficiency in presence of taurocholate, while decreased sporulation rate during biofilm development in the presence of glucose. In conclusion, these results show that, at least in this cohort of patients, the described phenotypes are not detrimental in the clinical outcome of the disease.

      PubDate: 2015-11-01T08:30:15Z
  • Virulence factors of Clostridium difficile and their role during infection
    • Abstract: Publication date: Available online 24 October 2015
      Author(s): Claire Janoir
      Clostridium difficile is the prominent etiological agent of healthcare-associated diarrhea. The disease symptoms range from mild diarrhea to life-threatening pseudomembranous colitis. The main risk factor for developing an infection after contamination by the resistant spores is the disruption of the gut microbiota, allowing the spores to germinate. The colonization of the gut is likely to be governed by the bacterial resistance to the host response and the bacterial adhesion to the mucosa. To date, several putative adhesins have been identified, most of them displaying MSCRAMM function, and studies of adhesin mutants have clearly underlined the multi-factorial feature of C. difficile adhesion to the host. Flagella have also been involved in the colonisation process, but their role depends on the tested strains. The clinical signs are mainly due to two large glucosylating toxins, TcdA and TcdB, which are essential for the disease manifestations. The importance of each toxin differs according to strains and experimental conditions, but TcdB seems to be the prominent one, as showed by mutant studies and the natural occurrence of pathogenic strains that do not produce TcdA. The role of the ADP ribosylating binary toxin expressed by some strains, including epidemic lineages, is not clearly established, although it has been related to higher morbidity and mortality. Production of low level of the glucosylating toxins and of the binary toxin seems to promote adhesion to host cells. Expression of the TcdA and TcdB genes is under the control of the second messenger c-di-GMP. This is also the case for other virulence factors, in particular for flagellar, pili type IV and some adhesin genes. Indeed, several studies using knock-out mutants suggest that C. difficile may undergo a switch between the adhesion phenotype and the motility phenotype during the course of infection, regulated by the c-di-GMP intracellular level. In vivo, this could result in biofilm formation that, associated with persistence of spores, could promote the occurrence of relapses observed in at least 20% of patients.

      PubDate: 2015-10-28T08:10:28Z
  • BV and non-BV associated Gardnerella vaginalis establish similar
           synergistic interactions with other BV-associated microorganism in
           dual-species biofilms
    • Abstract: Publication date: Available online 24 October 2015
      Author(s): Joana Castro, Nuno Cerca
      Dual-species biofilm formation between Gardnerella vaginalis strains isolated from women with or without bacterial vaginosis (BV) and other 24 BV-associated microorganisms support that the key difference in virulence potential between BV-negative and BV-positive G. vaginalis strains seems not to be related with biofilm maturation.

      PubDate: 2015-10-28T08:10:28Z
  • Immunogenic properties of the surface layer precursor of Clostridium
           difficile and vaccination assays in animal models
    • Abstract: Publication date: Available online 24 October 2015
      Author(s): J.-F. Bruxelle, A. Mizrahi, S. Hoys, A. Collignon, C. Janoir, S. Péchiné
      Clostridium difficile is an opportunistic pathogen causing gut inflammation generally associated with an intestinal dysbiosis due to antibiotics. Several virulence factors have been identified as playing a key role in gut colonization. The surface-layer proteins, comprised of two proteins, the high molecular weight SlpA (HMW-SLP) and the low molecular weight SlpA (LMW-SLP), are the most abundant proteins on the C. difficile surface. These two proteins are derived from the Cwp84-mediated cleavage of a single precursor protein SlpA. In this study, we assessed the immunogenic properties of a recombinant SlpA precursor derived from a toxigenic C. difficile strain (630) and its protective effect as a vaccine antigen co-administered with the cholera toxin as an adjuvant in both hamster and mouse models. First, we confirmed the immunogenicity of SlpA in humans. Sera from patients with C. difficile infection were analyzed by ELISA. Patients with CDI have a greater number of SlpA antibodies than healthy patients, confirming the immunogenicity of this protein during the pathogenic process. Then, rectal vaccination assays were performed in both conventional hamsters and mice. The animals’ sera were sampled before and after vaccination, and were analyzed by ELISA. In addition, in the mouse model, feces were sampled after vaccination and IgA directed against SlpA were detected by ELISA. In both models, the intestinal colonization was evaluated by fecal bacterial count after challenge. Intra-rectal vaccination with SlpA and cholera toxin as an adjuvant induced a local and systemic humoral immune response in mice and hamsters potentially responsible for the weak decrease of C. difficile colonization in mice and the partial protection observed in a lethal-hamster model.

      PubDate: 2015-10-28T08:10:28Z
  • Clinical Significance of Direct Cytotoxicity and Toxigenic Culture in C.
           difficile Infection
    • Abstract: Publication date: Available online 24 October 2015
      Author(s): E. Reigadas, L. Alcalá, M. Marín, P. Muñoz-Pacheco, P. Catalán, A. Martin, E. Bouza
      Background Clostridium difficile infection (CDI) is the leading cause of hospital-acquired diarrhoea in developed countries. Although an optimal diagnosis is crucial, laboratory diagnostics remain challenging. Currently, the reference methods are direct cytotoxicity assay and toxigenic culture; however there is controversy in the interpretation of discordant results of these tests. Objective The aim of our study was to determine the clinical significance of detecting C. difficile only by toxigenic culture with a negative direct cytotoxicity assay. Methods We conducted a prospective study in which patients aged >2 years with CDI were enrolled and monitored at least 2 months after their last episode. Samples were tested by both cytotoxicity assay and toxigenic culture. Results During the 6-month study period, we identified 169 episodes meeting CDI criteria that had been tested by both assays, out of which 115 were positive for both cytotoxicity assay and toxigenic culture, and 54 CDI episodes (31.9%) were positive only by toxigenic culture. Overall, patients median age was 71.3, 50.9% were male and the most frequent underlying disease was malignancy. The comparison of CDI episodes positive for both assays and by toxigenic culture only revealed the following, respectively: mild CDI (77.4% vs 94.4%; p=0.008), severe CDI (21.7% vs 5.6%; p=0.008), severe complicated (0.9% vs 0.0%; p=1.000), pseudomembranous colitis (1.7% vs 1.9% p=1.000), recurrence (17.4% vs 14.8%; p=0.825), overall mortality (8.7% vs 7.4%; p=1.000) and CDI related mortality (2.6% vs 0%; p=0.552). Conclusion CDI episodes positive by cytotoxicity assay were more severe than those positive only by toxigenic culture, however there were a significant proportion of CDI cases (31.9%) that would have been missed if only cytotoxicity had been considered as clinically significant for CDI treatment, including severe CDI cases. Our data suggest that a positive test by toxigenic culture with a negative result for cytotoxicity should not be interpreted as colonization.

      PubDate: 2015-10-28T08:10:28Z
  • From culturomics to taxonomogenomics: A need to change the taxonomy of
           prokaryotes in clinical microbiology
    • Abstract: Publication date: Available online 27 October 2015
      Author(s): Pierre-Edouard Fournier, Jean-Christophe Lagier, Gregory Dubourg, Didier Raoult
      By diversifying culture conditions, in a strategy named culturomics, we were able in a short time to grow 124 new bacterial species from human stools, including 39 strict anaerobes. To describe these microorganisms, we use genome sequencing and MALDI-TOF mass spectrometry. Both tools have been major breakthroughs in clinical microbiology over the past decade, have previously been used for taxonomic purposes, and have the advantage over chemotaxonomic methods and DNA-DNA hybridization, to exhibit an excellent intra- and inter-laboratory reproducibility. We developed a polyphasic taxonomic strategy including MALDI-TOF MSand genomic analyses to describe new bacterial species associated with human beings. This strategy, that we have named taxono-genomics, was used to propose the description of 48 new species, the names of 13 of which have officially been validated. In this manuscript, we briefly reviewed the pros and cons of the currently validated taxonomic tools and propose that genomic sequencing and MALDI-TOF mass spectrometry may be incorporated in the taxonomic classification of prokaryotes.

      PubDate: 2015-10-28T08:10:28Z
  • Clostridium polynesiense sp. nov., a new member of the human gut
           microbiota in French Polynesia
    • Abstract: Publication date: Available online 17 October 2015
      Author(s): Senthil Alias Sankar, Jaishriram Rathored, Sarah Metidji, Jean-Christophe Lagier, Saber Khelaifia, Noemie Labas, Didier Musso, Didier Raoult, Pierre-Edouard Fournier
      Strain MS1, a Gram-positive, obligately anaerobic, motile and spore-forming rod belonging to the Clostridium genus, was isolated from the feces of a healthy Polynesian male living in French Polynesia. The temperature range for growth was 30 to 45°C. We sequenced its complete genome and studied its phenotypic characteristics. The 3,560,738-bp long genome (one chromosome, no plasmid, G+C content 34%) contained 3,535 protein-coding and 70 RNA genes. Strain MS1 exhibited a 98.24% 16S rRNA similarity with C. amylolyticum, the phylogenetically closest species. When compared with other Clostridium species with standing in nomenclature, it had an average genomic similarity of 68.8 to 70%, a unique MALDI-TOF spectrum, and differed in nitrate reduction, motility and L-arabinose and D-lactose metabolism with most of the closest species. Therefore, strain MS1 is sufficiently distinct from type strains of the genus Clostridium to represent a novel species within this genus, for which the name Clostridium polynesiense sp. nov. is proposed. The type strain of C. polynesiense is MS1T (= CSUR P630 = DSM 27072).

      PubDate: 2015-10-24T07:48:54Z
  • The non-toxigenic Clostridium difficile CD37 protects mice against
           infection with a BI/NAP1/027 type of C. difficile strain
    • Abstract: Publication date: Available online 13 October 2015
      Author(s): Keshan Zhang, Song Zhao, Yuankai Wang, Xuejun Zhu, Hong Shen, Yugen Chen, Xingmin Sun
      C. difficile CD37, a clinical isolate from the USA, does not produce toxin A, B or binary toxin. The aim of this study was to determine whether strain CD37 can protect mice against infection from a challenge with a toxigenic C. difficile strain. Three groups of mice (n=10) were pretreated with a antibiotics cocktail for 5 days, switched to sterile water for 2 days, and given one dose of clindamycin (10 mg/kg) one day (day-1) before challenge (day 0) with a toxigenic C. difficile strain. Group 1 (CD37+UK6) was given 107 C. difficile CD37 vegetative cells by gavage twice a day on days -1 and -2, followed by challenge with 106 spores of the toxigenic C. difficile UK6 (BI/NAPI/027) on day 0; Group 2 (UK6) was infected with 106 C. difficile UK6 spores on day 0; Group 3 (CD37) was challenged with 106 CD37 vegetative cells on day 0. Our data show that pre-inoculation with strain CD37 provided significant protection (survival, p < 0.001 between groups CD37+UK6 and UK6) against subsequent infection with the strain UK6, while mice infected with CD37 only did not develop any symptoms of C. difficile infection (CDI). Our results highlight the potential use of CD37 as a therapeutic strain for the prevention of primary and recurrent CDI in humans.

      PubDate: 2015-10-24T07:48:54Z
  • Polymicrobial infection alter inflammatory microRNA in rat salivary glands
           during periodontal disease
    • Abstract: Publication date: Available online 22 October 2015
      Author(s): Gautam Nayar, Adrienne Gauna, Sasanka Chukkapalli, Irina Velsko, Lakshmyya Kesavalu, Seunghee Cha
      Periodontal disease initiated by subgingival pathogens is linked with diminished secretion of saliva, and implies pathogenic bacteria dissemination to or affects secondary sites such as the salivary glands. MicroRNAs activated in response to bacteria may modulate immune responses against pathogens. Therefore, Sprague-Dawley rats were infected by oral lavage consisting of polymicrobial inocula, namely Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola, or sham-infected for 12 weeks (n=6). We quantified inflammatory miRNA expression levels of miRNA-132, miR-146a, and miR-155 at secondary sites to the primary infection of the gingiva, including submandibular salivary glands, lacrimal glands, and pancreas. The presence of bacteria was detected in situ at secondary sites. Infected rat gingiva showed increased relative expression of miR-155. In contrast, miRNA-155 expression was decreased in submandibular salivary glands, along with positive identification of P. gingivalis in 2/6 and T. denticola in 1/6 rat salivary glands. Furthermore, miRNA-132 and miRNA-146a were significantly decreased in the pancreas of infected rats. This study is the first to show primary periodontal infections can alter miRNA profiles in secondary sites such as the salivary gland and pancreas. Whether these alterations contribute to pathologies of salivary glands in Sjögren’s syndrome or of pancreas in diabetes warrants further investigation.

      PubDate: 2015-10-24T07:48:54Z
  • Comparison of culture-dependent and independent approaches to characterize
           fecal bifidobacteria and lactobacilli
    • Abstract: Publication date: Available online 19 October 2015
      Author(s): Andrea Quartieri, Marta Simone, Caterina Gozzoli, Mina Popovic, Giuseppe D'Auria, Alberto Amaretti, Stefano Raimondi, Maddalena Rossi
      Different culture-dependent and independent methods were applied to investigate the population of bifidobacteria and lactobacilli in the feces of five healthy subjects. Bacteria were isolated on MRS, a complex medium supporting growth of lactobacilli and bifidobacteria, and on three selective media for bifidobacteria and two for lactobacilli. Taxonomic characterization of the isolates was carried out by RAPD-PCR and partial 16S sequencing. The selectivity of genus-specific media was also investigated by challenging colonies from MRS plates to grow onto each medium. In parallel, a quantitative and qualitative description of bifidobacteria and lactic acid bacteria was obtained by FISH, qPCR, TRFLP, and 16S rRNA gene sequencing. Bifidobacteria did not fail to grow on their specific media and were easily isolated and enumerated, showing comparable quantitative data among culture-dependent and -independent techniques. The Bifidobacterium species identified on plates and those extracted from TRFLP and 16S rRNA gene sequencing were mostly overlapping. Selective media for lactobacilli gave unsuitable results, being too stringent or too permissive. The quantification of lactobacilli through selective plates, qPCR, FISH, and 16S rRNA gene sequencing gave unreliable results. Therefore, unlike bifidobacteria, intestinal lactobacilli are still problematic in terms of quantification and accurate profiling at level of species and possibly of strains by both culture-dependent and culture-independent techniques.

      PubDate: 2015-10-24T07:48:54Z
  • Infectious Endocarditis Caused by Parvimonas micra
    • Abstract: Publication date: Available online 17 October 2015
      Author(s): Carlos A. Gomez, Daniel A. Gerber, Eduardo Zambrano, Niaz Banaei, Stan Deresinski, Brian G. Blackburn
      P. micra is an anaerobic Gram-positive cocci, and a known commensal organism of the human oral cavity and gastrointestinal tract. Although it has been classically described in association with endodontic disease and peritonsillar infection, recent reports have highlighted the role of P. micra as the primary pathogen in the setting of invasive infections. In its most recent taxonomic classification, P. micra has never been reported causing infectious endocarditis in humans. Here, we describe a 71 year-old man who developed severe native valve endocarditis complicated by aortic valvular destruction and perivalvular abscess, requiring emergent surgical intervention. Molecular sequencing enabled identification of P. micra.

      PubDate: 2015-10-24T07:48:54Z
  • Editorial board
    • Abstract: Publication date: October 2015
      Source:Anaerobe, Volume 35, Part B

      PubDate: 2015-10-11T17:00:45Z
  • Improvement of the butanol production selectivity and butanol to acetone
           ratio (B:A) by addition of electron carriers in the batch culture of a new
           local isolate of Clostridium acetobutylicum YM1
    • Abstract: Publication date: Available online 9 October 2015
      Author(s): Najeeb Kaid Nasser Al-Shorgani, Mohd Sahaid Kalil, Wan Mohtar Wan Yusoff, Chowdhury Mohammad Monirul Hasan, Aidil Abdul Hamid
      Improvement in the butanol production selectivity or enhanced butanol: acetone ratio (B:A) is desirable in acetone-butanol-ethanol (ABE) fermentation by Clostridium strains. In this study, artificial electron carriers were added to the fermentation medium of a new isolate of Clostridium acetobutylicum YM1 in order to improve the butanol yield and B:A ratio. The results revealed that medium supplementation with electron carriers changed the metabolism flux of electron and carbon in ABE fermentation by YM1. A decrease in acetone production, which subsequently improved the B:A ratio, was observed. Further improvement in the butanol production and B:A ratios were obtained when the fermentation medium was supplemented with butyric acid. The maximum butanol production (18.20±1.38 g/L) was gained when a combination of methyl red and butyric acid was added. Although the addition of benzyl viologen (0.1 mM) and butyric acid resulted in high a B:A ratio of 16:1 (800% increment compared with the conventional 2:1 ratio), the addition of benzyl viologen to the culture after 4 h resulted in the production of 18.05 g/L butanol. Manipulating the metabolic flux to butanol through the addition of electron carriers could become an alternative strategy to achieve higher butanol productivity and improve the B:A ratio.

      PubDate: 2015-10-11T17:00:45Z
  • Distribution and characterization of Clostridium difficile isolated from
           dogs in Japan
    • Abstract: Publication date: Available online 9 October 2015
      Author(s): Masaru Usui, Kaname Suzuki, Kentaro Oka, Kentaro Miyamoto, Motomichi Takahashi, Takashi Inamatsu, Shigeru Kamiya, Yutaka Tamura
      We collected 204 canine fecal samples and isolated 68 Clostridium difficile strains from 62 of these samples. Of these strains, 47% were toxigenic. These strains comprised 29 PCR ribotypes, and the most frequent ribotype (n = 16, 24%) was toxigenic.

      PubDate: 2015-10-11T17:00:45Z
  • Performance Management of Clostridium difficile Infection in Hospitals
           – the Carrot or Stick Approach'
    • Abstract: Publication date: Available online 9 October 2015
      Author(s): Fidelma Fitzpatrick, Mary O. Riordan
      Public and political pressure for healthcare quality indicator monitoring, specifically healthcare-associated infection (HAI) has intensified the debate regarding the merits of public reporting and target setting as policy approaches. This paper reviews the evidence for these approaches with a focus on HAI, including Clostridium difficile infection (CDI). Healthcare key performance indicators (KPIs) and associated targets have been used widely with little evaluation. While targets are associated with some HAI reductions including CDI, as their control is multi-factorial, it is likely that reductions are due to numerous, concurrent control measures. Targets may help tackle organizational-wide issues that require high level management engagement and have contributed to the increased access and influence of infection control teams. HAI public reporting has also gained traction and is mandatory in many countries despite little scientific evaluation. CDI is one of the KPIs used but there is little consensus as to the best KPI for public reporting. Countries without public reporting have also seen improvements. Using indicator-based strategies rather than evidence-based ones risk improving the KPI but not necessarily quality of care. ‘Bottom-up’ approaches focusing on quality improvement and innovation generated by front line staff are seen as a lever for sustainable change. Positive deviance, where the resourcefulness and problem solving abilities of staff is harnessed, enables ‘bottom-up’ changes with process and outcome improvements. As implementation of best practice in healthcare is dependent on behavioural and cultural change, it is most likely that a combination of ‘top-down’ and ‘bottom-up’ approaches are required for sustainable improvement. This combined approach was used to improve staff influenza vaccination rates. Regulation may initially direct the spot-light onto infection control needs but true sustainable HAI reduction will only be fostered with concurrent cultural and behavioural shifts in practice and ownership of the HAI burden across clinical, policy and management domains. It will be interesting if this approach will be increasingly used by policy makers, however, irrespective it is clear that there is a need for rigorous evaluation of our HAI policy approaches from this point forward.

      PubDate: 2015-10-11T17:00:45Z
  • Fibronectin-binding protein TDE1579 affects cytotoxicity of Treponema
    • Abstract: Publication date: Available online 9 October 2015
      Author(s): Xiaoping Xu, Bjorn Steffensen, Trista K. Robichaud, Margarita Mikhailova, Veronica Lai, Ryan Montgomery, Lianrui Chu
      While FbpA, a family of bacterial fibronectin (FN) binding proteins has been studied in several gram-positive bacteria, the gram-negative Treponema denticola, an anaerobic periodontal pathogen, also has an overlooked fbp gene (tde1579). In this research, we confirm that recombinant Fbp protein (rFbp) of T. denticola binds human FN with a K dapp of 1.5 × 10-7 M and blocks the binding of T. denticola to FN in a concentration-dependent manner to a level of 42%. The fbp gene was expressed in T. denticola. To reveal the roles of fbp in T. denticola pathogenesis, an fbp isogenic mutant was constructed. The fbp mutant had 51% reduced binding ability to human gingival fibroblasts (hGF). When hGF were challenged with T. denticola, the fbp mutant caused less cell morphology change, had 50% reduced cytotoxicity to hGF, and had less influence on the growth of hGF cells.

      PubDate: 2015-10-11T17:00:45Z
  • Isolation and characterization of Clostridium difficile from pet dogs in
           Assam, India
    • Abstract: Publication date: Available online 21 September 2015
      Author(s): Isfaqul Hussain, R.K. Sharma, P. Borah, S. Rajkhowa, Iftikar Hussain, L.M. Barkalita, D. Hasin, M. Chaudhury, M. Rupnik, N.K. Deka, G.K. Saikia
      One hundred and seventeen faecal samples from pet dogs (pup = 21 and adult = 96) brought for treatment to a veterinary clinic were examined for Clostridium difficile. A total of 16 (13.67%) samples were positive. Nine (56.25%) isolates were obtained from 17 adult dogs undergoing antibiotic treatment and this was significantly higher (p < 0.01) as compared to isolates from dogs without antibiotic treatment. Ten isolates (62.5%) were toxigenic (all toxinotype 0) and six were non-toxigenic. None of the isolates were positive for binary toxin genes. PCR ribotyping revealed three different ribotypes (012, 014 and 046) among A+B+ isolates and five different ribotypes (010, SLO 131, and ACD 001 to ACD 003) among A-B- isolates. The PFGE analysis of toxigenic isolates revealed three different pulsotypes corresponding to the PCR ribotypes.

      PubDate: 2015-09-25T15:41:11Z
  • Does estradiol have an impact on the dipeptidyl peptidase iv enzyme
           activity of the prevotella intermedia group bacteria'
    • Abstract: Publication date: Available online 18 September 2015
      Author(s): Dareen Fteita, Eija Könönen, Mervi Gürsoy, Eva Söderling, Ulvi Kahraman Gürsoy
      Initiation and development of pregnancy-associated gingivitis is seemingly related to the microbial shift towards specific gram-negative anaerobes in subgingival biofilms. It is known that Prevotella intermedia sensu lato is able to use estradiol as an alternative source of growth instead of vitamin K. The aim of the present study was to investigate the impact of estradiol on the bacterial dipeptidyl peptidase IV (DPPIV) enzyme activity in vitro as a virulent factor of the P. intermedia group bacteria, namely P. intermedia, Prevotella nigrescens, Prevotella pallens, and Prevotella aurantiaca. In all experiments, 2 strains of each Prevotella species were used. Bacteria were incubated with the concentrations of 0, 30, 90, and 120 nmol/L of estradiol and were allowed to build biofilms at an air-solid interface. DPPIV activities of biofilms were measured kinetically during 20 min using a fluorometric assay. The enzyme activity was later related to the amount of protein produced by the same biofilm, reflecting the biofilm mass. Estradiol significantly increased DPPIV activities of the 8 Prevotella strains in a strain- and dose-dependent manner. In conclusion, our in vitro experiments indicate that estradiol regulates the DPPIV enzyme activity of P. intermedia, P. nigrescens, P. pallens, and P. aurantiaca strains differently. Our results may, at least partly, explain the role of estradiol to elicit a virulent state which contributes to the pathogenesis of pregnancy-related gingivitis.

      PubDate: 2015-09-21T15:36:29Z
  • Identification and antimicrobial susceptibility of obligate anaerobic
           bacteria from clinical samples of animal origin
    • Abstract: Publication date: Available online 15 September 2015
      Author(s): Melissa Mayorga, Evelyn Rodríguez-Cavallini, Diana López-Ureña, Elías Barquero-Calvo, Carlos Quesada-Gómez
      The etiology of veterinary infectious diseases has been the focus of considerable research, yet relatively little is known about the causative agents of anaerobic infections. Susceptibility studies have documented the emergence of antimicrobial resistance and indicate distinct differences in resistance patterns related to veterinary hospitals, geographic regions, and antibiotic-prescribing regimens. The aim of the present study was to identify the obligate anaerobic bacteria from veterinary clinical samples and to determinate the in vitro susceptibility to eight antimicrobials and their resistance-associated genes. 81 clinical specimens obtained from food-producing animals, pets and wild animals were examined to determine the relative prevalence of obligate anaerobic bacteria, and the species represented. Bacteroides spp, Prevotella spp and Clostridium spp represented approximately 80% of all anaerobic isolates. Resistance to metronidazole, clindamycin, tetracycline and fluoroquinolones was found in strains isolated from food-producing animals. Ciprofloxacin, enrofloxacin and cephalotin showed the highest resistance in all isolates. In 17%, 4% and 14% of tetracycline-resistant isolates, the resistance genes tetL, tetM and tetW were respectively amplified by PCR whereas in 4% of clindamycin-resistant strains the ermG gene was detected. 26% of the isolates were positive for cepA, while only 6% harbored the cfxA (resistance-conferring genes to beta-lactams). In this study, the obligate anaerobic bacteria from Costa Rica showed a high degree of resistance to most antimicrobials tested. Nevertheless, in the majority of cases this resistance was not related to the resistance acquired genes usually described in anaerobes. It is important to address and regulate the use of antimicrobials in the agricultural industry and the empirical therapy in anaerobic bacterial infections in veterinary medicine, especially since antibiotics and resistant bacteria can persist in the environment.

      PubDate: 2015-09-17T15:22:58Z
  • The functional dlt operon of Clostridium butyricum controls the
           D-alanylation of cell wall components and influences cell septation and
           vancomycin-induced lysis
    • Abstract: Publication date: Available online 10 September 2015
      Author(s): Sandra Wydau-Dematteis, Mathilde Louis, Noël Zahr, René Lai-Kuen, Bruno Saubaméa, Marie-José Butel, Jean-Louis Pons
      Clostridium butyricum is a Gram-positive bacterium involved in the development of necrotizing enterocolitis (NEC) in preterm infants. To colonize the digestive tract, components of the cell wall of C. butyricum must interact with the intestinal mucosa. The D-alanylation of cell wall components such as teichoic acids results in a net positive charge on the cell wall, which is important for many functions of Gram-positive bacteria. Notably, D-alanylation mediates resistance to antimicrobial peptides and antibiotics. Here, we show that the dlt operon of C. butyricum encodes the enzymes responsible for the D-alanylation of cell wall components and influences the surface properties of the cell wall. We show that the D-alanylation of cell wall components controls the septation of C. butyricum, which is an essential mechanism during vegetative growth. Furthermore, we find that D-alanylation is involved in the resistance of C. butyricum to some cationic antimicrobial peptides (CAMPs) and lysozyme. Finally, we show that the D-alanylation of cell wall components influences vancomycin-induced lysis.
      Graphical abstract image

      PubDate: 2015-09-13T14:32:46Z
  • Anaerobic Prosthetic Joint Infection
    • Abstract: Publication date: Available online 1 September 2015
      Author(s): Neel B. Shah, Aaron J. Tande, Robin Patel, Elie F. Berbari
      In an effort to improve mobility and alleviate pain from degenerative and connective tissue joint disease, an increasing number of individuals are undergoing prosthetic joint replacement in the United States. Joint replacement is a highly effective intervention, resulting in improved quality of life and increased independence [1]. By 2030, it is predicted that approximately 4 million total hip and knee arthroplasties will be performed yearly in the United States [2]. One of the major complications associated with this procedure is prosthetic joint infection (PJI), occurring at a rate of 1-2% [3-7]. In 2011, the Musculoskeletal Infectious Society created a unifying definition for prosthetic joint infection [8]. The following year, the Infectious Disease Society of America published practice guidelines that focused on the diagnosis and management of PJI. These guidelines focused on the management of commonly encountered organisms associated with PJI, including staphylococci, streptococci and select aerobic Gram-negative bacteria. However, with the exception of Propionibacterium acnes, management of other anaerobic organisms was not addressed in these guidelines [1]. Although making up approximately 3-6% of PJI [9, 10], anaerobic microorganisms cause devastating complications, and similar to the more common organisms associated with PJI, these bacteria also result in significant morbidity, poor outcomes and increased health-care costs. Data on diagnosis and management of anaerobic PJI is mostly derived from case reports, along with a few cohort studies [3]. There is a paucity of published data outlining factors associated with risks, diagnosis and management of anaerobic PJI. We therefore reviewed available literature on anaerobic PJI by systematically searching the PubMed database, and collected data from secondary searches to determine information on pathogenesis, demographic data, clinical features, diagnosis and management. We focused our search on five commonly encountered anaerobic organisms associated with PJI. Since anaerobic PJI has also been linked to dental procedures, we also reviewed information on the use of dental procedures and prophylaxis, when available.

      PubDate: 2015-09-04T14:00:52Z
  • Effect of Bdellovibrio bacteriovorus HD100 on multispecies oral
    • Abstract: Publication date: October 2015
      Source:Anaerobe, Volume 35, Part A
      Author(s): Gitte Loozen, Nico Boon, Martine Pauwels, Vera Slomka, Esteban Rodrigues Herrero, Marc Quirynen, Wim Teughels
      The predation of Bdellovibrio bacteriovorus on different periodontal pathogens has already been described. However, it is necessary to consider the polymicrobial nature of periodontal disease. The current study explores the predation of Bdellovibrio on oral pathogens organized in multispecies communities. The effect of the predator was evaluated on in vitro six species communities with microbial culturing. Additionally, the effect on ex vivo subgingival plaque and saliva samples from periodontitis patients was assessed. In the latter experiment results were examined with microbial culturing, quantitative polymerase chain reaction (qPCR) and denaturing gradient gel electrophoresis (DGGE). The latter technique was used to get an overview of the whole mixed microbial population. Results showed that even in more complex models, B. bacteriovorus was still able to predate on Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans. However predation on Prevotella intermedia and Porphyromonas gingivalis could not be validated in multispecies models. The effect of Bdellovibrio was not restricted to the target bacteria. Changes in the overall ecology of the different models were evident. It could be concluded that the efficiency of predation decreased when complexity of the models increased. However, B. bacteriovorus was able to attack two important oral pathogens, F. nucleatum, and A. actinomycetemcomitans, even when present in ex vivo clinical samples. These effects still have to be validated in in vivo models to see the impact of Bdellovibrio on the whole bacterial ecology.

      PubDate: 2015-08-19T12:30:23Z
  • 16S rRNA based microarray analysis of ten periodontal bacteria in patients
           with different forms of periodontitis
    • Abstract: Publication date: October 2015
      Source:Anaerobe, Volume 35, Part A
      Author(s): Nursen Topcuoglu, Guven Kulekci
      DNA microarray analysis is a computer based technology, that a reverse capture, which targets 10 periodontal bacteria (ParoCheck) is available for rapid semi-quantitative determination. The aim of this three-year retrospective study was to display the microarray analysis results for the subgingival biofilm samples taken from patient cases diagnosed with different forms of periodontitis. A total of 84 patients with generalized aggressive periodontitis (GAP,n:29), generalized chronic periodontitis (GCP, n:25), peri-implantitis (PI,n:14), localized aggressive periodontitis (LAP,n:8) and refractory chronic periodontitis (RP,n:8) were consecutively selected from the archives of the Oral Microbiological Diagnostic Laboratory. The subgingival biofilm samples were analyzed by the microarray-based identification of 10 selected species. All the tested species were detected in the samples. The red complex bacteria were the most prevalent with very high levels in all groups. Fusobacterium nucleatum was detected in all samples at high levels. The green and blue complex bacteria were less prevalent compared with red and orange complex, except Aggregatibacter actinomycetemcomitas was detected in all LAP group. Positive correlations were found within all the red complex bacteria and between red and orange complex bacteria especially in GCP and GAP groups. Parocheck enables to monitoring of periodontal pathogens in all forms of periodontal disease and can be alternative to other guiding and reliable microbiologic tests.

      PubDate: 2015-08-19T12:30:23Z
  • Antibiotic susceptibility of 33 Prevotella strains isolated from Romanian
           patients with abscesses in head and neck spaces
    • Abstract: Publication date: October 2015
      Source:Anaerobe, Volume 35, Part A
      Author(s): Gabriela Bancescu, Andreea Didilescu, Adrian Bancescu, Maria Bari
      The purpose of this study was to investigate the susceptibility of a series of 33 Prevotella strains isolated from patients with abscesses in the head and neck spaces, presented to one Romanian hospital. The Etest was applied to determine the value of the minimum inhibitory concentrations for: penicillin G, ampicillin, amoxicillin-clavulanate, metronidazole and clindamycin. In addition, the beta-lactamase activity was detected by the chromogenic cephalosporin disc method. The results indicated that 11 isolates were resistant to both penicillin G and ampicillin due to the beta-lactamase production. All the 33 Prevotella strains were susceptible to the other 3 antimicrobial agents tested, except for only one penicillin G – ampicillin resistant isolate of Prevotella buccae (MIC > 32 and MIC = 12 mg/L, respectively), which showed high resistance to clindamycin (MIC > 256 mg/L) too. Our data underline the necessity for antimicrobial testing including monitoring of beta-lactamase production in cases of oro-maxillo-facial mixed anaerobic infections where antimicrobial treatment is required in addition to the surgical drainage. The results of the study indicated that amoxicillin-clavulanate, like metronidazole, was fully active against the tested Prevotella strains. However, local and multicentre surveys on drug resistance among the clinically significant anaerobic isolates should be carried out periodically.

      PubDate: 2015-08-19T12:30:23Z
  • Bacterial profiles and proteolytic activity in peri-implantitis versus
           healthy sites
    • Abstract: Publication date: October 2015
      Source:Anaerobe, Volume 35, Part A
      Author(s): J. Neilands, C. Wickström, B. Kinnby, J.R. Davies, J. Hall, B. Friberg, G. Svensäter
      Peri-implantitis is a biofilm-induced destructive inflammatory process that, over time, results in loss of supporting bone around an osseointegrated dental implant. Biofilms at peri-implantitis sites have been reported to be dominated by Gram-negative anaerobic rods with a proteolytic metabolism such as, Fusobacterium, Porphyromonas, Prevotella and Tannerella, as well as anaerobic Gram-positive cocci. In this study, we hypothesized that protease activity is instrumental in driving bone destruction and we therefore compared the microbial composition and level of protease activity in samples of peri-implant biofluid (PIBF) from 25 healthy subjects (H group) and 25 subjects with peri-implantitis (PI group). Microbial composition was investigated using culture techniques and protease activity was determined using a FITC-labelled casein substrate. The microbial composition was highly variable in subjects both in the H and PI groups but one prominent difference was the prevalence of Porphyromonas/Prevotella and anaerobic Gram positive cocci which was significantly higher in the PI than in the H group. A subgroup of subjects with peri-implantitis displayed a high level of protease activity in the PIBF compared to healthy subjects. However, this activity could not be related to the presence of specific bacterial species. We propose that a high level of protease activity may be a predictive factor for disease progression in peri-implantitis. Further longitudinal studies are however required to determine whether assessment of protease activity could serve as a useful method to identify patients at risk for progressive tissue destruction.

      PubDate: 2015-08-19T12:30:23Z
  • Hydrogen sulfide production from subgingival plaque samples
    • Abstract: Publication date: October 2015
      Source:Anaerobe, Volume 35, Part A
      Author(s): A. Basic, G. Dahlén
      Periodontitis is a polymicrobial anaerobe infection. Little is known about the dysbiotic microbiota and the role of bacterial metabolites in the disease process. It is suggested that the production of certain waste products in the proteolytic metabolism may work as markers for disease severity. Hydrogen sulfide (H2S) is a gas produced by degradation of proteins in the subgingival pocket. It is highly toxic and believed to have pro-inflammatory properties. We aimed to study H2S production from subgingival plaque samples in relation to disease severity in subjects with natural development of the disease, using a colorimetric method based on bismuth precipitation. In remote areas of northern Thailand, adults with poor oral hygiene habits and a natural development of periodontal disease were examined for their oral health status. H2S production was measured with the bismuth method and subgingival plaque samples were analyzed for the presence of 20 bacterial species with the checkerboard DNA–DNA hybridization technique. In total, 43 subjects were examined (age 40–60 years, mean PI 95 ± 6.6%). Fifty-six percent had moderate periodontal breakdown (CAL > 3 < 7 mm) and 35% had severe periodontal breakdown (CAL > 7 mm) on at least one site. Parvimonas micra, Filifactor alocis, Porphyromonas endodontalis and Fusobacterium nucleatum were frequently detected. H2S production could not be correlated to periodontal disease severity (PPD or CAL at sampled sites) or to a specific bacterial composition. Site 21 had statistically lower production of H2S (p = 0.02) compared to 16 and 46. Betel nut chewers had statistically significant lower H2S production (p = 0.01) than non-chewers. Rapid detection and estimation of subgingival H2S production capacity was easily and reliably tested by the colorimetric bismuth sulfide precipitation method. H2S may be a valuable clinical marker for degradation of proteins in the subgingival pocket.

      PubDate: 2015-08-19T12:30:23Z
  • Quantitation of biofilm and planktonic life forms of coexisting
           periodontal species
    • Abstract: Publication date: October 2015
      Source:Anaerobe, Volume 35, Part A
      Author(s): Maribasappa Karched, Radhika G. Bhardwaj, Anandavalli Inbamani, Sirkka Asikainen
      Background Complexity of oral polymicrobial communities has prompted a need for developing in vitro models to study behavior of coexisting bacteria. Little knowledge is available of in vitro co-growth of several periodontitis-associated species without early colonizers of dental plaque. The aim was to determine temporal changes in the quantities of six periodontal species in an in vitro biofilm model in comparison with parallel planktonic cultures. Material and methods Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Parvimonas micra, Campylobacter rectus and Fusobacterium nucleatum were anaerobically grown as multispecies and monospecies biofilms and parallel planktonic cultures using cell culture plates and microfuge tubes, respectively. After incubating 2, 4, 6, 8 days, biofilms and planktonic cultures were harvested, DNA extracted and the target species quantified using qPCR with species-specific 16S rDNA primers. Biofilm growth as monocultures was visualized at day 2 and 8 with confocal microscopy and crystal violet staining. Results The six species were found throughout the test period in all culture conditions, except that P. gingivalis and F. nucleatum were not detected in multispecies planktonic cultures at day 8. In multispecies biofilm, P. gingivalis qPCR counts (cells/ml) increased (P<0.05) from day 2–8 and were then higher (P<0.05) than those of A. actinomycetemcomitans and C. rectus, whereas in monospecies biofilm, P. gingivalis counts were lower (P<0.05) than those of the other species, except A. actinomycetemcomitans. When multi- and monospecies biofilm cultures were compared, P. gingivalis counts were higher (P<0.05) but those of the other species, except P. intermedia, lower (P<0.05) in multispecies biofilm. Comparison between planktonic and biofilm cultures showed that A. actinomycetemcomitans, P. micra and C. rectus had higher (P<0.05) counts in planktonic cultures no matter whether grown in mono- or multispecies environment. Conclusions Six periodontal species were able to form multispecies biofilm up to 8 days in vitro without pioneer plaque bacteria. P. gingivalis seemed to prefer multispecies biofilm environment whereas P. micra and A. actinomycetemcomitans planktonic culture.

      PubDate: 2015-08-19T12:30:23Z
  • Relationship between methanogenic archaea and subgingival microbial
           complexes in human periodontitis
    • Abstract: Publication date: October 2015
      Source:Anaerobe, Volume 35, Part A
      Author(s): H.P. Horz, N. Robertz, M.E. Vianna, K. Henne, G. Conrads
      We compared the amounts of methanogenic archaea with ten of the most important periodontal pathogens in 125 clinical samples. Correlation analysis suggests that the support of the periodontitis-associated bacterial consortium by methanogenic archaea may be driven through direct or indirect interactions with Prevotella intermedia.

      PubDate: 2015-08-19T12:30:23Z
  • Editorial board
    • Abstract: Publication date: October 2015
      Source:Anaerobe, Volume 35, Part A

      PubDate: 2015-08-19T12:30:23Z
  • LuxS signaling in Porphyromonas gingivalis-host interactions
    • Abstract: Publication date: October 2015
      Source:Anaerobe, Volume 35, Part A
      Author(s): Nina Scheres, Richard J. Lamont, Wim Crielaard, Bastiaan P. Krom
      Dental plaque is a multispecies biofilm in the oral cavity that significantly influences oral health. The presence of the oral anaerobic pathogen Porphyromonas gingivalis is an important determinant in the development of periodontitis. Direct and indirect interactions between P. gingivalis and the host play a major role in disease development. Transcriptome analysis recently revealed that P. gingivalis gene-expression is regulated by LuxS in both an AI-2-dependent and an AI-2 independent manner. However, little is known about the role of LuxS-signaling in P. gingivalis-host interactions. Here, we investigated the effect of a luxS mutation on the ability of P. gingivalis to induce an inflammatory response in human oral cells in vitro. Primary periodontal ligament (PDL) fibroblasts were challenged with P. gingivalis ΔluxS or the wild-type parental strain and gene-expression of pro-inflammatory mediators IL-1β, IL-6 and MCP-1 was determined by real-time PCR. The ability of P. gingivalis ΔluxS to induce an inflammatory response was severely impaired in PDL-fibroblasts. This phenotype could be restored by providing of LuxS in trans, but not by addition of the AI-2 precursor DPD. A similar phenomenon was observed in a previous transcriptome study showing that expression of PGN_0482 was reduced in the luxS mutant independently of AI-2. We therefore also analyzed the effect of a mutation in PGN_0482, which encodes an immuno-reactive, putative outer-membrane protein. Similar to P. gingivalis ΔluxS, the P. gingivalis Δ0482 mutant had an impaired ability to induce an inflammatory response in PDL fibroblasts. LuxS thus appears to influence the pro-inflammatory responses of host cells to P. gingivalis, likely through regulation of PGN_0482.

      PubDate: 2015-08-19T12:30:23Z
  • Comparative analysis of extractable proteins from Clostridium perfringens
           type A and type C strains showing varying degree of virulence
    • Abstract: Publication date: Available online 31 July 2015
      Author(s): Pratistha Dwivedi, Syed Imteyaz Alam, Om Kumar, Ravi Bhushan Kumar
      The prevailing scenario of bioterrorism warrants development of medical countermeasures with expanded coverage of select agents. Clostridium perfringens is a pathogen of medical, veterinary and military importance, and has been listed as Validated Biological Agent. We employed 2DE-MS approach to identify a total of 134 unique proteins (529 protein spot features) from the extractable proteome of four type A and type C strains. Proteins showing altered expression under host-simulated conditions from virulent type A strain (ATCC13124) were also elucidated. Significant among the differentially expressed proteins were elongation factor, molecular chaperones, ribosomal proteins, carbamoyl phosphate synthase, clpB protein, choloylglycine hydrolase, phosphopyruvate hydratase, and trigger factor. Predictive elucidation, of putative virulence associated proteins and sequence conservation pattern of selected candidates, was carried out using homologous proteins from other bacterial select agents to screen for the commonality of putative antigenic determinants. Pathogens (17 select agents) were observed to form three discrete clusters; composition of I and II being consistent in most of the phylogenetic reconstructions. This work provides a basis for further validation of putative candidate proteins as prophylactic agents and for their ability to provide protection against clusters of pathogenic select bacterial agents; aimed at mitigating the shadows of biothreat.
      Graphical abstract image

      PubDate: 2015-08-02T03:26:01Z
  • Functional analysis of the type II toxin-antitoxin systems of the MazEF
           and RelBE families in Bifidobacterium longum subsp. infantis ATCC 15697
    • Abstract: Publication date: Available online 23 July 2015
      Author(s): Olga Averina, Maria Alekseeva, Andrei Shkoporov, Valery Danilenko
      Analysis of the Bifidobacterium longum subsp. infantis ATCC 15697 genome sequence for the presence of toxin-antitoxin genes revealed two relBE-like operons, three relB-mazF-like operons, one relB-vapC-like operon, one solitary gene coding for the MazF toxin and one gene coding for the RelB antitoxin. An attempt to clone the selected relE and mazF toxin genes from B. longum subsp. infantis ATCC 15697 revealed their toxic effects on Escherichia coli, which could be neutralized by coexpression of these toxins with their cognate antitoxins. The only two toxin proteins, RelE and VapC, that were found to be non-toxic to E. coli, were overproduced and purified. Electrophoretic assays showed that both RelE and VapC possessed direct endoribonuclease activity. The expression levels of toxin genes in B. longum subsp. infantis ATCC 15697 increased during the nutrient starvation and entry into the late stationary phase. The two relBE bicistronic operons relE2-relB1 and relE1-relB4 from B. longum subsp. infantis ATCC 15697 were cloned and overexpressed in B. longum subsp. longum NCC2705 strain. The strain B. longum NCC2705 [pCESH80::relE1-relB4] showed a significantly decreased growth rate with later onset of the log phase and decreased cells density in the stationary phase.

      PubDate: 2015-07-25T08:03:03Z
  • Gut Bifidobacterium microbiota in one-month-old Brazilian newborns
    • Abstract: Publication date: Available online 20 July 2015
      Author(s): Łukasz Grześkowiak, Tatiana Fiche Sales Teixeira, Solange Mara Bigonha, Guilherme Lobo, Seppo Salminen, Celia Lucia de Luces Fortes Ferreira
      Gut colonisation with bifidobacteria in early infancy is essential for the well-being of the infant. Gestational age and mode of delivery are among the factors influencing the colonisation process. The aim was to characterise the bifidobacterial composition in the gut of one-month-old full-term and pre-term Brazilian infants, both being delivered vaginally or by caesarean section. Fourthy nine Brazilian (Viçosa, Minas Gerais state) one-month-old infants were divided in two groups: full-term (n=24) and pre-term (n=25), and compared to each other. Each group was then characterised according to its mode of delivery. Infant stool samples were available for bifidobacterial characterisation by quantitative polymerase chain reaction (qPCR) method. All study infants were colonised by bifidobacteria. Bifidobacterium longum colonised all full-term and pre-term newborns. Differences were observed in counts of Bifidobacterium genus and Bifidobacterium longum between full-term and pre-term infants (8.8 log cells/g, IQR 7.9-9.1 vs. 7.1 log cells/g, IQR 6.6-8.6, p=0.02 and 8.3 log cells/g, IQR 6.7-9.1 vs. 6.4 log cells/g, IQR 6.1-6.7, p=0.001, respectively). Furthermore, the prevalence of Bifidobacterium lactis differed between pre-term caesarean and pre-term vaginally born infants (50.0 % vs. 93.8 %, p=0.023). Gut bifidobacterial composition of one-month-old full-term infants differs from that of pre-term newborns in Viçosa, Minas Gerais state, Brazil. Gestational age is a factor influencing bacterial numbers and species, while mode of delivery have an impact on the prevalence and quantity of bifidobacteria in studied infants. Bifidobacteria may have an impact on later health of the infants and the species B. longum and B. lactis might provide clues on the potential probiotic applications in pre-term newborns at the risk of developing postnatal complications.

      PubDate: 2015-07-21T07:51:22Z
  • First Clinical Description of Eggerthia catenaformis Bacteremia in a
           Patient with Dental Abscess
    • Abstract: Publication date: Available online 11 July 2015
      Author(s): Hayarpi H. Kordjian , Joyce D.J.H. Schultz , Flemming Schønning Rosenvinge , Jakob Møller , Rune M. Pedersen
      We present a case of Eggerthia catenaformis bacteremia originating from a dental abscess and imitating necrotizing fasciitis in a previously healthy adult. The isolates were easily identified by MALDI-TOF MS. The clinical course, surgical and antibiotic treatment as well as the successful outcome are reported.

      PubDate: 2015-07-13T07:07:23Z
  • Evaluation of immunomodulatory activity of two potential probiotic
           Lactobacillus strains by in vivo tests
    • Abstract: Publication date: October 2015
      Source:Anaerobe, Volume 35, Part B
      Author(s): Dayong Ren , Chang Li , Yanqing Qin , Ronglan Yin , Shouwen Du , Hongfeng Liu , Yanfang Zhang , Cuiyan Wang , Fengjun Rong , Ningyi Jin
      Here we evaluate the immunomodulatory function of two potential probiotic strains, Lactobacillus salivarius CICC 23174 and Lactobacillus plantarum CGMCC 1.557. Mice were fed with each Lactobacillus strain at different doses for several consecutive days. The effects of the two probiotic strains on immune organs, immune cells and immune molecules were investigated on days 10 and 20. Both Lactobacillus strains increased the spleen index, improved the spleen lymphocyte transformation rate, enhanced sIgA production and improved the number of CD11c+ CD80+ double-positive cells. L. plantarum CGMCC 1.557 was the more active strain in enhancing the phagocytic activity of macrophages, while, L. salivarius CICC 23174 was the more effective strain at maintaining the Th1/Th2 balance. This study suggests that these two Lactobacillus strains have beneficial effects on regulation of immune responses, which has promising implications for the development of ecological agents and functional foods.

      PubDate: 2015-07-08T06:30:23Z
  • 16S rDNA analysis of archaea indicates dominance of Methanobacterium and
           high abundance of Methanomassiliicoccaceae in rumen of Nili-Ravi buffalo
    • Abstract: Publication date: October 2015
      Source:Anaerobe, Volume 35, Part B
      Author(s): S.S. Paul , S.M. Deb , A. Dey , S.P.S. Somvanshi , D. Singh , R. Rathore , J. Stiverson
      The molecular diversity of rumen methanogens was investigated using 16S rDNA gene library prepared from the rumen contents of Nili-Ravi buffaloes. Microbial genomic DNA was isolated from four adult male fistulated buffaloes and PCR conditions were set up using specific primers. Amplified product was cloned into a suitable vector, and the inserts of positive clones were sequenced. A total of 142 clones were examined, and the analysis revealed 46 species level (0.01 distance) operational taxonomic units (OTUs). Twenty six OTUs comprising 89 clones (63% of the total clones) were taxonomically assigned to Methanobacterium genus and the majority of them had highest percent identity with Methanobacterium flexile among cultured methanogens. Five OTUs comprising 27 clones (19% of total clones) were taxonomically assigned to Methanomicrobium genus and these clones showed highest sequence identity with Methanomicrobium mobile. Only two OTUs comprising 6 clones (4% of total clones) were assigned to Methanobrevibacter genus. A total of 17 clones belonging to 10 species level OTUs showed highest percent identity (ranging from 85 to 95%) with Methanomassilicoccus luminyensis and were taxonomically classified as Methanomassiliicocaceae. Out of the 142 rDNA clones, 112 clones, which constitute 79% of the total clones representing 42 OTUs, had less than 98.5% sequence identity with any of the cultured strains of methanogens and represent novel species of methanogens. This study has revealed the largest assortment of hydrogenotrophic methanogen phylotypes ever identified from the rumen of Nili-Ravi buffaloes. The study indicates that Methanobacterium is the most dominant methanogen in the rumen of Nili-Ravi buffalo. This is also the first report on the presence of methanogens phylogenetically close to M. luminyensis, an H2 dependent methylotrophic methanogen, in the rumen of buffaloes at such a high level of abundance.

      PubDate: 2015-07-08T06:30:23Z
  • Actinomycosis of eye: Forgotten but not uncommon
    • Abstract: Publication date: October 2015
      Source:Anaerobe, Volume 35, Part B
      Author(s): Neha Mehrotra , Ankita Baidya , Megha Brijwal , Rita Aggarwal , Rama Chaudhry
      Actinomyces species are known to cause a variety of human infections. Ocular actinomycosis is a rare disease. We report an unusual case of bilateral actinomycotic blepharoconjunctivitis in the absence of canaliculitis that presented with forniceal masses in eye. The case report is discussed here along with Indian literature.

      PubDate: 2015-07-08T06:30:23Z
  • Clostridium amazonense sp. nov. an obliqately anaerobic bacterium isolated
           from a remote Amazonian community in Peru
    • Abstract: Publication date: Available online 26 June 2015
      Author(s): Lindsey O’Neal , Alexandra J. Obregón-Tito , Raul Y. Tito , Andrew T. Ozga , Susan I. Polo , Cecil M. Lewis Jr. , Paul A. Lawson
      A strictly anaerobic Gram-stain positive, spore-forming, rod-shaped bacterium designated NE08VT, was isolated from a fecal sample of an individual residing in a remote Amazonian community in Peru. Phylogenetic analysis based on the 16S rRNA gene sequence showed the organism belonged to the genus Clostridium and is most closely related to Clostridium vulturis (97.4% sequence similarity) and was further characterized using biochemical and chemotaxonomic methods. The major cellular fatty acids were anteiso C13:0 and C16:0 with a genomic DNA G + C content of 31.6 mol%. Fermentation products during growth on glucose were acetate and butyrate. Based on phylogenetic, phenotypic and chemotaxonomic information, strain NE08V was identified as representing a novel species of the genus Clostridium, for which the name Clostridium amazonense sp. nov. is proposed. The type strain is NE08VT (DSM 23598 T = CCUG 59712T).

      PubDate: 2015-07-08T06:30:23Z
  • Oral anaerobes in health and disease
    • Abstract: Publication date: Available online 3 June 2015
      Author(s): Georg Conrads

      PubDate: 2015-07-08T06:30:23Z
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2015