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BIOLOGY (1414 journals)            First | 1 2 3 4 5 6 7 8 | Last

Showing 801 - 1000 of 1720 Journals sorted alphabetically
Journal of Health and Biological Sciences     Open Access  
Journal of Heredity     Hybrid Journal   (Followers: 3)
Journal of Histology & Histopathology     Open Access   (Followers: 1)
Journal of Huazhong University of Science and Technology [Medical Sciences]     Hybrid Journal  
Journal of Human Evolution     Hybrid Journal   (Followers: 16)
Journal of Hymenoptera Research     Open Access   (Followers: 2)
Journal of Ichthyology     Hybrid Journal   (Followers: 3)
Journal of Insect Behavior     Hybrid Journal   (Followers: 9)
Journal of Insect Biodiversity     Open Access   (Followers: 3)
Journal of Insect Conservation     Hybrid Journal   (Followers: 10)
Journal of Integrated OMICS     Open Access  
Journal of Integrated Pest Management     Open Access   (Followers: 1)
Journal of Integrative Environmental Sciences     Hybrid Journal   (Followers: 4)
Journal of Intelligent Transportation Systems: Technology, Planning, and Operations     Hybrid Journal   (Followers: 4)
Journal of Invertebrate Pathology     Hybrid Journal   (Followers: 3)
Journal of Landscape Ecology     Open Access   (Followers: 12)
Journal of Law and the Biosciences     Open Access   (Followers: 2)
Journal of Leukocyte Biology     Open Access   (Followers: 2)
Journal of Life and Earth Science     Open Access  
Journal of Life Sciences Research     Open Access  
Journal of Lipid Research     Full-text available via subscription   (Followers: 6)
Journal of Lipids     Open Access  
Journal of Luminescence     Hybrid Journal   (Followers: 3)
Journal of Mammalian Evolution     Hybrid Journal   (Followers: 5)
Journal of Mammalian Ova Research     Full-text available via subscription  
Journal of Mammalogy     Full-text available via subscription   (Followers: 11)
Journal of Mammary Gland Biology and Neoplasia     Hybrid Journal   (Followers: 1)
Journal of Marine and Aquatic Sciences     Open Access  
Journal of Marine Biology     Open Access   (Followers: 12)
Journal of Mathematical Biology     Hybrid Journal   (Followers: 12)
Journal of Mechanics in Medicine and Biology     Hybrid Journal  
Journal of Medical Primatology     Hybrid Journal   (Followers: 1)
Journal of Medical Toxicology     Hybrid Journal   (Followers: 4)
Journal of Medicine and Philosophy     Hybrid Journal   (Followers: 7)
Journal of Melittology     Open Access  
Journal of Membrane Biology     Hybrid Journal   (Followers: 1)
Journal of Membrane Science     Hybrid Journal   (Followers: 14)
Journal of Molecular Biology     Hybrid Journal   (Followers: 48)
Journal of Molecular Biology Research     Open Access   (Followers: 3)
Journal of Molecular Catalysis B: Enzymatic     Hybrid Journal   (Followers: 2)
Journal of Molecular Cell Biology     Hybrid Journal   (Followers: 13)
Journal of Molecular Evolution     Hybrid Journal   (Followers: 9)
Journal of Molecular Signaling     Open Access  
Journal of Molecular Structure     Hybrid Journal   (Followers: 6)
Journal of Molluscan Studies     Hybrid Journal   (Followers: 1)
Journal of Muscle Research and Cell Motility     Hybrid Journal   (Followers: 1)
Journal of Mycology     Open Access   (Followers: 3)
Journal of Nanoparticle Research     Hybrid Journal   (Followers: 3)
Journal of Nanoparticles     Open Access  
Journal of Natural History     Hybrid Journal   (Followers: 8)
Journal of Natural Products     Full-text available via subscription   (Followers: 10)
Journal of Natural Science, Biology and Medicine     Open Access   (Followers: 2)
Journal of Natural Sciences Research     Open Access   (Followers: 4)
Journal of Negative Results in BioMedicine     Open Access   (Followers: 1)
Journal of Nematology     Open Access   (Followers: 1)
Journal of Neuroscience and Behavioral Health     Open Access  
Journal of New Seeds     Hybrid Journal  
Journal of Nucleic Acids     Open Access  
Journal of Parasitology     Full-text available via subscription   (Followers: 13)
Journal of Parasitology and Vector Biology     Open Access   (Followers: 1)
Journal of Pharmacological and Toxicological Methods     Hybrid Journal   (Followers: 5)
Journal of Phycology     Hybrid Journal   (Followers: 6)
Journal of Physics D : Applied Physics     Hybrid Journal   (Followers: 9)
Journal of Physics: Condensed Matter     Hybrid Journal   (Followers: 6)
Journal of Physics: Conference Series     Open Access   (Followers: 2)
Journal of Phytopathology     Hybrid Journal   (Followers: 2)
Journal of Plankton Research     Hybrid Journal   (Followers: 3)
Journal of Plant Ecology     Hybrid Journal   (Followers: 15)
Journal of Pollination Ecology     Open Access  
Journal of Porphyrins and Phthalocyanines     Hybrid Journal   (Followers: 1)
Journal of Progressive Research in Biology     Open Access  
Journal of Proteome Research     Full-text available via subscription   (Followers: 12)
Journal of Proteomics     Hybrid Journal   (Followers: 10)
Journal of Purdue Undergraduate Research     Open Access   (Followers: 1)
Journal of Radiation Research and Applied Sciences     Open Access   (Followers: 2)
Journal of Risk Research     Hybrid Journal   (Followers: 7)
Journal of Science of the University of Kelaniya Sri Lanka     Open Access  
Journal of Seed Science     Open Access  
Journal of Signal Transduction     Open Access   (Followers: 2)
Journal of Stem Cell Research & Therapy     Open Access   (Followers: 2)
Journal of Stored Products Research     Hybrid Journal  
Journal of Structural and Functional Genomics     Hybrid Journal   (Followers: 1)
Journal of Structural Biology     Hybrid Journal   (Followers: 9)
Journal of Sustainable Bioenergy Systems     Full-text available via subscription   (Followers: 1)
Journal of Sustainable Society     Open Access   (Followers: 6)
Journal of Systematic Palaeontology     Hybrid Journal   (Followers: 7)
Journal of Systematics Evolution     Open Access   (Followers: 4)
Journal of the American Mosquito Control Association     Full-text available via subscription   (Followers: 1)
Journal of the Korean Society for Applied Biological Chemistry     Hybrid Journal  
Journal of the Renin-Angiotensin-Aldosterone System     Open Access  
Journal of the Royal Society of New Zealand     Hybrid Journal   (Followers: 6)
Journal of the Selva Andina Research Society     Open Access   (Followers: 1)
Journal of the South Carolina Academy of Science     Open Access  
Journal of Theoretical Biology     Hybrid Journal   (Followers: 12)
Journal of Thermal Biology     Hybrid Journal   (Followers: 2)
Journal of Thyroid Research     Open Access  
Journal of Tissue Engineering     Open Access   (Followers: 6)
Journal of Vacuum Science & Technology A     Full-text available via subscription   (Followers: 2)
Journal of Vacuum Science & Technology B     Full-text available via subscription   (Followers: 2)
Journal of Vector Ecology     Free   (Followers: 2)
Journal of Vegetation Science     Full-text available via subscription   (Followers: 20)
Journal of Vinyl & Additive Technology     Hybrid Journal  
Journal of Virological Methods     Hybrid Journal   (Followers: 6)
Journal of Virology     Hybrid Journal   (Followers: 29)
Journal of Visualized Experiments     Full-text available via subscription   (Followers: 2)
Journal of Yeast and Fungal Research     Open Access  
Journal of Zhejiang University - Science B     Hybrid Journal  
Jurnal Fitopatologi Indonesia     Open Access  
Jurnal Penelitian Sains (JPS)     Open Access  
Jurnal Teknosains     Open Access  
Kahramanmaras Sutcu Imam University Journal Of Natural Sciences     Open Access  
Karbala International Journal of Modern Science     Open Access   (Followers: 3)
Kennedy Institute of Ethics Journal     Full-text available via subscription   (Followers: 6)
Kew Bulletin     Hybrid Journal   (Followers: 1)
KINOME     Open Access  
Knowledge and Management of Aquatic Ecosystems     Open Access   (Followers: 3)
Koedoe : African Protected Area Conservation and Science     Open Access   (Followers: 5)
Kurtziana     Open Access  
Landscape and Ecological Engineering     Hybrid Journal   (Followers: 4)
Large Marine Ecosystems     Full-text available via subscription  
Le Naturaliste canadien     Full-text available via subscription  
Letters in Mathematical Physics     Hybrid Journal   (Followers: 3)
Life     Open Access   (Followers: 2)
Life Sciences in Space Research     Hybrid Journal  
Life Sciences, Society and Policy     Open Access  
Limnological Papers     Open Access  
Lipid Insights     Open Access  
Lipid Technology     Hybrid Journal   (Followers: 2)
Lipids     Hybrid Journal   (Followers: 2)
Lipids in Health and Disease     Open Access  
Luminescence     Hybrid Journal   (Followers: 3)
mAbs     Full-text available via subscription   (Followers: 12)
Macromolecular Bioscience     Hybrid Journal   (Followers: 1)
Macromolecular Reaction Engineering     Hybrid Journal  
Madroño     Full-text available via subscription  
Malacologia     Full-text available via subscription  
Malacologica Bohemoslovaca     Open Access   (Followers: 1)
Malawi Journal of Science and Technology     Open Access   (Followers: 6)
Mammal Review     Hybrid Journal   (Followers: 6)
Mammal Study     Full-text available via subscription  
Mammalian Biology - Zeitschrift für Säugetierkunde     Hybrid Journal   (Followers: 4)
Mammalian Genome     Hybrid Journal   (Followers: 3)
Mammalian Species     Full-text available via subscription   (Followers: 1)
Manufacturing Engineer     Hybrid Journal   (Followers: 9)
Marine Biodiversity     Hybrid Journal   (Followers: 9)
Marine Biodiversity Records     Open Access   (Followers: 4)
Marine Biology     Hybrid Journal   (Followers: 56)
Marine Biotechnology     Hybrid Journal   (Followers: 4)
Marine Mammal Science     Hybrid Journal   (Followers: 9)
Materials Science and Engineering: C     Hybrid Journal   (Followers: 19)
Materials Technology : Advanced Performance Materials     Hybrid Journal   (Followers: 5)
Mathematical Biosciences     Hybrid Journal   (Followers: 3)
Mathematical Medicine and Biology: A Journal of the IMA     Hybrid Journal   (Followers: 2)
Mathematical Physics, Analysis and Geometry     Hybrid Journal   (Followers: 1)
Mathematical Problems in Engineering     Open Access   (Followers: 3)
Matrix Biology     Hybrid Journal   (Followers: 1)
mBio     Open Access   (Followers: 6)
Mechanisms of Ageing and Development     Hybrid Journal   (Followers: 2)
Mechanisms of Development     Hybrid Journal   (Followers: 5)
Médecine Nucléaire     Full-text available via subscription  
médecine/sciences     Full-text available via subscription   (Followers: 1)
Medical and Biological Engineering and Computing     Hybrid Journal   (Followers: 2)
Medical and Biological Sciences     Open Access  
Medical Engineering & Physics     Hybrid Journal   (Followers: 9)
Mediterranean Journal of Biosciences     Open Access  
Membrane Protein Transport     Full-text available via subscription   (Followers: 2)
Memoirs of the Association of Australasian Palaeontologists     Full-text available via subscription   (Followers: 2)
Messenger     Full-text available via subscription  
Metabolic Engineering     Hybrid Journal   (Followers: 13)
Metabolites     Open Access  
Metabolomics     Hybrid Journal   (Followers: 7)
Metallomics     Full-text available via subscription  
Metamorfosa : Journal of Bilogical Sciences     Open Access   (Followers: 1)
Methods     Hybrid Journal   (Followers: 12)
Methods in Cell Biology     Full-text available via subscription   (Followers: 6)
Methods in Cell Science     Hybrid Journal   (Followers: 3)
Methods in Ecology and Evolution     Partially Free   (Followers: 27)
Micologia Aplicada Internacional     Open Access  
Microarrays     Open Access  
Micron     Hybrid Journal  
Mitochondrial DNA     Hybrid Journal   (Followers: 4)
Mitochondrion     Hybrid Journal   (Followers: 3)
Modelling and Simulation in Engineering     Open Access   (Followers: 3)
Modelling and Simulation in Materials Science and Engineering     Hybrid Journal   (Followers: 7)
Modern Chemotherapy     Open Access  
Molecular & Cellular Proteomics     Full-text available via subscription   (Followers: 12)
Molecular & Cellular Toxicology     Hybrid Journal   (Followers: 2)
Molecular and Biochemical Parasitology     Hybrid Journal   (Followers: 2)
Molecular and Cellular Biochemistry     Hybrid Journal   (Followers: 4)
Molecular and Cellular Biology     Hybrid Journal   (Followers: 21)
Molecular Based Mathematical Biology     Open Access   (Followers: 1)
Molecular Biology     Hybrid Journal   (Followers: 10)
Molecular Biology and Evolution     Hybrid Journal   (Followers: 85)
Molecular Biology International     Open Access   (Followers: 2)
Molecular Biology of the Cell     Partially Free   (Followers: 19)
Molecular Biology Reports     Hybrid Journal   (Followers: 4)
Molecular Brain     Open Access   (Followers: 2)
Molecular Breeding     Hybrid Journal   (Followers: 9)
Molecular Cell     Full-text available via subscription   (Followers: 45)
Molecular Ecology     Hybrid Journal   (Followers: 29)

  First | 1 2 3 4 5 6 7 8 | Last

Journal Cover Anaerobe
  [SJR: 1.066]   [H-I: 51]   [4 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1075-9964 - ISSN (Online) 1095-8274
   Published by Elsevier Homepage  [3038 journals]
  • Heat shock increases conjugation efficiency in Clostridium difficile
    • Authors: Joseph A. Kirk; Robert P. Fagan
      Pages: 1 - 5
      Abstract: Publication date: December 2016
      Source:Anaerobe, Volume 42
      Author(s): Joseph A. Kirk, Robert P. Fagan
      Clostridium difficile infection has increased in incidence and severity over the past decade, and poses a unique threat to human health. However, genetic manipulation of C. difficile remains in its infancy and the bacterium remains relatively poorly characterised. Low-efficiency conjugation is currently the only available method for transfer of plasmid DNA into C. difficile. This is practically limiting and has slowed progress in understanding this important pathogen. Conjugation efficiency varies widely between strains, with important clinically relevant strains such as R20291 being particularly refractory to plasmid transfer. Here we present an optimised conjugation method in which the recipient C. difficile is heat treated prior to conjugation. This significantly improves conjugation efficiency in all C. difficile strains tested including R20291. Conjugation efficiency was also affected by the choice of media on which conjugations were performed, with standard BHI media giving most transconjugant recovery. Using our optimised method greatly increased the ease with which the chromosome of R20291 could be precisely manipulated by homologous recombination. Our method improves on current conjugation protocols and will help speed genetic manipulation of strains otherwise difficult to work with.

      PubDate: 2016-07-24T11:57:37Z
      DOI: 10.1016/j.anaerobe.2016.06.009
      Issue No: Vol. 42 (2016)
  • Effects of corn silage and grass silage in ruminant rations on diurnal
           changes of microbial populations in the rumen of dairy cows
    • Authors: Melanie B. Lengowski; Maren Witzig; Jens Möhring; Gero M. Seyfang; Markus Rodehutscord
      Pages: 6 - 16
      Abstract: Publication date: Available online 20 July 2016
      Author(s): Melanie B. Lengowski, Maren Witzig, Jens Möhring, Gero M. Seyfang, Markus Rodehutscord
      Here, we examined diurnal changes in the ruminal microbial community and fermentation characteristics of dairy cows fed total mixed rations containing either corn silage (CS) or grass silage (GS) as forage. The rations, which consisted of 52% concentrate and 48% GS or CS, were offered for ad libitum intake over 20 days to three ruminal-fistulated lactating Jersey cows during three consecutive feeding periods. Feed intake, ruminal pH, concentrations of short chain fatty acids and ammonia in rumen liquid, as well as abundance change in the microbial populations in liquid and solid fractions, were monitored in 4-h intervals on days 18 and 20. The abundance of total bacteria and Fibrobacter succinogenes increased in solids in cows fed CS instead of GS, and that of protozoa increased in both solid and liquid fractions. Feeding GS favored numbers of F. succinogenes and Selenomonas ruminantium in the liquid fraction as well as the numbers of Ruminobacter amylophilus, Prevotella bryantii and ruminococci in both fractions. Minor effects of silage were detected on populations of methanogens. Despite quantitative changes in the composition of the microbial community, fermentation characteristics were less affected by forage source. These results suggest a functional adaptability of the ruminal microbiota to total mixed rations containing either GS or CS as the source of forage. Diurnal changes in microbial populations were primarily affected by feed intake and differed between species and fractions, with fewer temporal fluctuations evident in the solid than in the liquid fraction. Interactions between forage source and sampling time were of minor importance to most of the microbial species examined. Thus, diurnal changes of microbial populations and fermentative activity were less affected by the two silages.

      PubDate: 2016-07-24T11:57:37Z
      DOI: 10.1016/j.anaerobe.2016.07.004
      Issue No: Vol. 42 (2016)
  • Analysis of the rumen bacterial diversity of goats during shift from
           forage to concentrate diet
    • Authors: Diego Javier Grilli; Kateřina Fliegerová; Jan Kopečný; Sebastián Paez Lama; Vanina Egea; Noelia Sohaefer; Celia Pereyra; María Soledad Ruiz; Miguel Angel Sosa; Graciela Nora Arenas; Jakub Mrázek
      Pages: 17 - 26
      Abstract: Publication date: Available online 12 July 2016
      Author(s): Diego Javier Grilli, Kateřina Fliegerová, Jan Kopečný, Sebastián Paez Lama, Vanina Egea, Noelia Sohaefer, Celia Pereyra, María Soledad Ruiz, Miguel Angel Sosa, Graciela Nora Arenas, Jakub Mrázek
      High-grain feeding used in the animal production is known to affect the host rumen bacterial community, but our understanding of consequent changes in goats is limited. This study was therefore aimed to evaluate bacterial population dynamics during 20 days adaptation of 4 ruminally cannulated goats to the high-grain diet (grain: hay – ratio of 40:60). The dietary transition of goats from the forage to the high-grain-diet resulted in the significant decrease of rumen fluid pH, which was however still higher than value established for acute or subacute ruminal acidosis was not diagnosed in studied animals. DGGE analysis demonstrated distinct ruminal microbial populations in hay-fed and grain-fed animals, but the substantial animal-to-animal variation were detected. Quantitative PCR showed for grain-fed animals significantly higher number of bacteria belonging to C. leptum group at 10 days after the incorporation of corn into the diet and significantly lower concentration of bacteria belonging to Actinobacteria phylum at the day 20 after dietary change. Taxonomic distribution analysed by NGS at day 20 revealed the similar prevalence of the phyla Firmicutes and Bacteroidetes in all goats, significantly higher presence of the unclassified genus of groups of Bacteroidales and Ruminococcaceae in grain-fed animals and significantly higher presence the genus Prevotella and Butyrivibrio in the forage-fed animals. The three different culture-independent methods used in this study show that high proportion of concentrate in goat diet does not induce any serious disturbance of their rumen ecosystem and indicate the good adaptive response of caprine ruminal bacteria to incorporation of corn into the diet.

      PubDate: 2016-07-24T11:57:37Z
      DOI: 10.1016/j.anaerobe.2016.07.002
      Issue No: Vol. 42 (2016)
  • Changes in the antibiotic susceptibility of anaerobic bacteria from
           2007–2009 to 2010–2012 based on the CLSI methodology
    • Authors: Christine J. Hastey; Halsey Boyd; Audrey N. Schuetz; Karen Anderson; Diane M. Citron; Jody Dzink-Fox; Meredith Hackel; David W. Hecht; Nilda V. Jacobus; Stephen G. Jenkins; Maria Karlsson; Cynthia C. Knapp; Laura M. Koeth; Hannah Wexler; Darcie E. Roe-Carpenter
      Pages: 27 - 30
      Abstract: Publication date: Available online 15 July 2016
      Author(s): Christine J. Hastey, Halsey Boyd, Audrey N. Schuetz, Karen Anderson, Diane M. Citron, Jody Dzink-Fox, Meredith Hackel, David W. Hecht, Nilda V. Jacobus, Stephen G. Jenkins, Maria Karlsson, Cynthia C. Knapp, Laura M. Koeth, Hannah Wexler, Darcie E. Roe-Carpenter
      Antimicrobial susceptibility testing of anaerobic isolates was conducted at four independent sites from 2010 to 2012 and compared to results from three sites during the period of 2007–2009. This data comparison shows significant changes in antimicrobial resistance in some anaerobic groups. Therefore, we continue to recommend institutions regularly perform susceptibility testing when anaerobes are cultured from pertinent sites. Annual generation of an institutional-specific antibiogram is recommended for tracking of resistance trends over time.

      PubDate: 2016-07-24T11:57:37Z
      DOI: 10.1016/j.anaerobe.2016.07.003
      Issue No: Vol. 42 (2016)
  • A case of multiple recurrence of Clostridium difficile infection with
           severe hematochezia in an immunocompromised host
    • Authors: Xuewu Zhang; Yunbo Chen; Silan Gu; Beiwen Zheng; Tao Lv; Yinjun Lou; Jie Jin
      Pages: 31 - 32
      Abstract: Publication date: Available online 1 July 2016
      Author(s): Xuewu Zhang, Yunbo Chen, Silan Gu, Beiwen Zheng, Tao Lv, Yinjun Lou, Jie Jin
      Clostridium difficile infection (CDI) is increasing in incidence and severity. Clinically, diarrhea frequently occurs, but severe hematochezia is rarely seen with CDI. We describe here a hematopoietic stem cell transplantation (HSCT) recipient who experienced life-threatening gastrointestinal bleeding due to severe CDI. Subsequent stool surveillance and molecular typing observed the patient who had two episodes of recurrence with a new strain of C. difficile distinct from the initial infection. We analyze C. difficile strains obtained from the patient, and also discuss the diagnosis and treatment of this case.

      PubDate: 2016-07-24T11:57:37Z
      DOI: 10.1016/j.anaerobe.2016.06.010
      Issue No: Vol. 42 (2016)
  • Robinsoniella peoriensis, originally isolated from swine manure, and early
           periprosthetic hip infection: Case report and review of the literature
    • Authors: Heime Rieber; Andre Frontzek; Andreas Bell; Lars Frommelt
      Pages: 33 - 36
      Abstract: Publication date: Available online 30 July 2016
      Author(s): Heime Rieber, Andre Frontzek, Andreas Bell, Lars Frommelt
      We report on the first case of a periprosthetic joint infection with the anaerobic spore-forming Gram-positive rod Robinsoniella peoriensis as the causative agent. The bacterium was first isolated from a swine manure storage pit and has so far rarely been associated with human infections.

      PubDate: 2016-08-03T12:28:56Z
      DOI: 10.1016/j.anaerobe.2016.07.005
      Issue No: Vol. 42 (2016)
  • Porphyromonas pogonae identification from a soft tissue infection: The
           first human case
    • Authors: Bongyoung Kim; Hyunjoo Pai; Kyu Tae Hwang; Yangsoon Lee
      Pages: 37 - 39
      Abstract: Publication date: December 2016
      Source:Anaerobe, Volume 42
      Author(s): Bongyoung Kim, Hyunjoo Pai, Kyu Tae Hwang, Yangsoon Lee
      We report a first human case of Porphyromonas pogonae causing soft tissue infection in a patient with open fracture. Strong β-hemolytic, aerotolerant, and non-pigmented gram-negative coccobacilli which matched Porphyromonas pogonae by PCR for 16S rRNA genes were identified from the pus specimen. The clinical course of the patient improved with repeated surgical drainage and tigecycline administration.

      PubDate: 2016-08-12T13:08:31Z
      DOI: 10.1016/j.anaerobe.2016.08.002
      Issue No: Vol. 42 (2016)
  • A genetic assay for gene essentiality in Clostridium
    • Authors: David J.F. Walker; John T. Heap; Klaus Winzer; Nigel P. Minton
      Pages: 40 - 43
      Abstract: Publication date: Available online 31 July 2016
      Author(s): David J.F. Walker, John T. Heap, Klaus Winzer, Nigel P. Minton
      Essential genes of pathogens are potential therapeutic targets, but are difficult to verify. Here, gene essentiality was determined by targeted knockout following engineered gene duplication. Null mutants of candidate essential genes of Clostridium difficile were viable only in the presence of a stable second copy of the gene.

      PubDate: 2016-08-03T12:28:56Z
      DOI: 10.1016/j.anaerobe.2016.07.007
      Issue No: Vol. 42 (2016)
  • First isolation of Clostridium indolis in a patient with chronic osteitis:
           A case report and literature review of human infections related to
           Clostridium saccharolyticum group species
    • Authors: Romain Lotte; Laurène Lotte; Philippe Bouvet; Nicolas Degand; Antonin Bal; Michel Carles; Regis Bernard de Dompsure; Michel-Robert Popoff; Raymond Ruimy
      Pages: 44 - 49
      Abstract: Publication date: Available online 7 August 2016
      Author(s): Romain Lotte, Laurène Lotte, Philippe Bouvet, Nicolas Degand, Antonin Bal, Michel Carles, Regis Bernard de Dompsure, Michel Popoff, Raymond Ruimy
      Clostridium indolis is an anaerobic spore-forming Gram-positive bacillus belonging to the Clostridium saccharolyticum group. Its clinical significance in human remains poorly known. We describe the first case of osteitis related to C. indolis, identified by MALDI-TOF mass spectrometry and provide a literature review of human infections related to C. saccharolyticum group species.

      PubDate: 2016-08-12T13:08:31Z
      DOI: 10.1016/j.anaerobe.2016.08.001
      Issue No: Vol. 42 (2016)
  • Multidrug-resistant oral Capnocytophaga gingivalis responsible for an
           acute exacerbation of chronic obstructive pulmonary disease: Case report
           and literature review
    • Authors: Elodie Ehrmann; Anne Jolivet-Gougeon; Martine Bonnaure-Mallet; Thierry Fosse
      Pages: 50 - 54
      Abstract: Publication date: Available online 13 August 2016
      Author(s): Elodie Ehrmann, Anne Jolivet-Gougeon, Martine Bonnaure-Mallet, Thierry Fosse
      Introduction Capnocytophaga genus was recently known to highly contribute to the beta-lactam (BL) and macrolide-lincosamide-streptogramin (MLS) resistance gene reservoir in the oral microbiota (BL: bla CSP-1 and bla CfxA; MLS: erm(F) and erm(C)). But fluoroquinolone (FQ) resistance remains uncommon in literature, without available data on resistance mechanisms. Case report For the first time, a case of acute exacerbation of chronic obstructive pulmonary disease (COPD) was described in a 78-year-old immunocompetent patient due to a multidrug-resistant Capnocytophaga gingivalis isolate with significant microbiological finding. C.gingivalis acquired resistance to third generation cephalosporins (bla CfxA3 gene), MLS (erm(F) gene), and fluoroquinolones. Genetics of the resistance, unknown as regards fluoroquinolone, was investigated and a substitution in QRDR of GyrA was described (Gly80Asn substitution) for the first time in the Capnocytophaga genus. Literature review A comprehensive literature review of Capnocytophaga spp. extra-oral infection was conducted. Including the present report, on 43 cases, 7 isolates were BL-resistant (17%), 4 isolates were MLS-resistant (9.5%) and 4 isolates were FQ-resistant (9.5%). The studied clinical isolate of C.gingivalis was the only one to combine resistance to the three groups of antibiotics BL, MLS and FQ. Four cases of Capnocytophaga lung infection were reported, including three infections involving C. gingivalis (two FQ resistant) and one involving C. sputigena. Conclusion This multidrug-resistant C. gingivalis isolate illustrated the role of oral flora as a reservoir of antibiotic resistance and its contribution to the limitation of effective antibiotics in severe respiratory infections.

      PubDate: 2016-08-16T13:27:29Z
      DOI: 10.1016/j.anaerobe.2016.08.003
      Issue No: Vol. 42 (2016)
  • Evaluation of oral microbiota in undernourished and eutrophic children
           using checkerboard DNA-DNA hybridization
    • Authors: M. Testa; S. Erbiti; A. Delgado; I.L. Cardenas
      Pages: 55 - 59
      Abstract: Publication date: Available online 20 August 2016
      Author(s): M. Testa, S. Erbiti, A. Delgado, I.L. Cardenas
      The aim of this study was to evaluate the relationship among nutritional status, gingival health and the composition of oral microbiota in children of a public school from a very poor area of San Miguel de Tucuman. Forty-five children ranging in age from 6 to 14 years old, 13 males and 32 females were studied. Twenty of these children were undernourished (Lejarraga-Morasso Table) and twenty-five were eutrophic. A clinical study that included DMF and dmf indexes, Löe Silness Plaque Index and bleeding on probing was performed. For microbiological study, saliva samples without stimulation were taken; aliquots of them were immediately placed in TAE buffer pH 7.6, adding NaOH (N and keeping at -70 °C until processed by checkerboard DNA-DNA hybridization method to check the presence of 40 oral microorganism species. Positive bleeding on probing was present in more than 80% of children, without significant differences between eutrophic and undernourished groups. Same result were obtain for the other clinical indexes (p > 0.05, Two Way ANOVA). Significant differences were found for some oral microorganism species, with a higher percentage of undernourished children harboring them. That was the case of S. gordonii (p < 0.05), Capnocitophaga gingivalis and C. ochraceae (p < 0.01 and p < 0.10, respectively), F. nucleatum ss nucleatum (p < 0.05), P. nigrescens (p < 0.10), Campylobacter gracilis (p < 0,05), and T. denticola (p < 0.10, multiple logistic regression). Significant differences were also found between children groups for E. saborreum (p < 0.001), P. acnes (p < 0.10), G. morbillorum (p < 0.05) and L. buccalis (p < 0.10). Gingivitis and bleeding on probing would not be related to nutritional status in the groups of children studied. There were significant differences for the presence of some of the main periodontal pathogen species between eutrophic and undernourished children. It would be important to study the meaning of significant differences found for the other microorganisms more deeply.

      PubDate: 2016-08-21T13:47:36Z
      DOI: 10.1016/j.anaerobe.2016.08.005
      Issue No: Vol. 42 (2016)
  • In vitro analysis of partially hydrolyzed guar gum fermentation on
           identified gut microbiota
    • Authors: Justin Carlson; Trevor Gould; Joanne Slavin
      Pages: 60 - 66
      Abstract: Publication date: Available online 30 August 2016
      Author(s): Justin Carlson, Trevor Gould, Joanne Slavin
      Background Prebiotic dietary fibers resist digestion in the upper gastrointestinal tract and allow for stimulation of bacteria in the distal intestine and colon. Stimulation of bacteria among different individuals varies greatly, depending on a wide range of variables. Objective To determine the range of differences in response between individuals, a preclinical in vitro fermentation was conducted with six fecal donors. The primary objective was to compare the fecal microbiota of six individuals at baseline, 12 h and 24 h post-exposure to partially hydrolyzed guar gum (PHGG). Method Fecal donations were collected from six healthy individuals consuming a non-specific Western diet, free of antibiotic treatments in the past year, not affected by any GI diseases and not consuming any probiotic or prebiotic supplements. Fecal samples were exposed to 0.5 g of PHGG and measured for bacterial changes at 0, 12 and 24 h base on 16S rRNA sequencing. Results Parabacteroides increased from 3.48% of sequence reads to 10.62% of sequence reads after 24 h (p = 0.0181) and Bacteroidetes increased from 45.89% of sequence reads to 50.29% of sequence reads (p = 0.0008). Conclusions PHGG stimulates growth of Parabacteroides, a genus of bacteria that have been inversely associated with IBS and ulcerative colitis. PHGG provides stimulation of beneficial Bacteroidetes (Bacteroides and Parabacteroides), which may be correlated with many positive health markers and outcomes. PHGG is a prebiotic dietary fiber that is readily fermentable.

      PubDate: 2016-08-31T14:28:41Z
      DOI: 10.1016/j.anaerobe.2016.08.006
      Issue No: Vol. 42 (2016)
  • Preface for Anaerobe – Special issue on Clostpath9
    • Authors: Panagiotis Papatheodorou; Klaus Aktories
      First page: 1
      Abstract: Publication date: October 2016
      Source:Anaerobe, Volume 41
      Author(s): Panagiotis Papatheodorou, Klaus Aktories

      PubDate: 2016-09-30T16:09:34Z
      DOI: 10.1016/j.anaerobe.2016.04.008
      Issue No: Vol. 41 (2016)
  • Tohru Shimizu Memorial
    • Authors: Julian I. Rood; Bruce A. McClane; Kaori Ohtani
      Pages: 3 - 4
      Abstract: Publication date: October 2016
      Source:Anaerobe, Volume 41
      Author(s): Julian I. Rood, Bruce A. McClane, Kaori Ohtani

      PubDate: 2016-09-30T16:09:34Z
      DOI: 10.1016/j.anaerobe.2016.04.007
      Issue No: Vol. 41 (2016)
  • Functional analysis of an feoB mutant in Clostridium perfringens strain 13
    • Authors: Milena M. Awad; Jackie K. Cheung; Joanne E. Tan; Alastair G. McEwan; Dena Lyras; Julian I. Rood
      Pages: 10 - 17
      Abstract: Publication date: October 2016
      Source:Anaerobe, Volume 41
      Author(s): Milena M. Awad, Jackie K. Cheung, Joanne E. Tan, Alastair G. McEwan, Dena Lyras, Julian I. Rood
      Bacterial pathogens have adopted numerous mechanisms for acquiring iron from host proteins during an infection, including the direct acquisition of ferric iron from heme-associated proteins or from iron-scavenging siderophores. Ferric iron then is transported into the cytosol, where it can be utilized by the bacterial pathogen. Under anaerobic conditions bacteria can also transport ferrous iron using the transmembrane complex FeoAB, but little is known about iron transport systems in anaerobic bacteria such as the pathogenic clostridia. In this study we sought to characterize the iron acquisition process in Clostridium perfringens. Bioinformatic analysis of the Clostridium perfringens strain 13 genome sequence revealed that it has seven potential iron acquisition systems: three siderophore-mediated systems, one ferric citrate uptake system, two heme-associated acquisition systems and one ferrous iron uptake system (FeoAB). The relative level of expression of these systems was determined using quantitative real-time RT-PCR assays that were specific for one gene from each system. Each of these genes was expressed, with the feoAB genes generating the most abundant iron-uptake related transcripts. To further examine the role of this system in the growth of C. perfringens, insertional inactivation was used to isolate a chromosomal feoB mutant. Growth of this mutant in the presence and absence of iron revealed that it had altered growth properties and a markedly reduced total iron and manganese content compared to the wild type; effects that were reversed upon complementation with the wild-type feoB gene. These studies suggest that under anaerobic conditions FeoB is the major protein required for the uptake of iron into the cell and that it may play an important role in the pathogenesis of C. perfringens infections.
      Graphical abstract image

      PubDate: 2016-09-30T16:09:34Z
      DOI: 10.1016/j.anaerobe.2016.05.005
      Issue No: Vol. 41 (2016)
  • The interaction of Clostridium perfringens enterotoxin with receptor
    • Authors: Archana Shrestha; Francisco A. Uzal; Bruce A. McClane
      Pages: 18 - 26
      Abstract: Publication date: October 2016
      Source:Anaerobe, Volume 41
      Author(s): Archana Shrestha, Francisco A. Uzal, Bruce A. McClane
      Clostridium perfringens enterotoxin (CPE) has significant medical importance due to its involvement in several common human gastrointestinal diseases. This 35 kDa single polypeptide toxin consists of two domains: a C-terminal domain involved in receptor binding and an N-terminal domain involved in oligomerization, membrane insertion and pore formation. The action of CPE starts with its binding to receptors, which include certain members of the claudin tight junction protein family; bound CPE then forms a series of complexes, one of which is a pore that causes the calcium influx responsible for host cell death. Recent studies have revealed that CPE binding to claudin receptors involves interactions between the C-terminal CPE domain and both the 1st and 2nd extracellular loops (ECL-1 and ECL-2) of claudin receptors. Of particular importance for this binding is the docking of ECL-2 into a pocket present in the C-terminal domain of the toxin. This increased understanding of CPE interactions with claudin receptors is now fostering the development of receptor decoy therapeutics for CPE-mediated gastrointestinal disease, reagents for cancer therapy/diagnoses and enhancers of drug delivery.

      PubDate: 2016-09-30T16:09:34Z
      DOI: 10.1016/j.anaerobe.2016.04.011
      Issue No: Vol. 41 (2016)
  • Bile acid sensitivity and in vivo virulence of clinical Clostridium
           difficile isolates
    • Authors: Brittany B. Lewis; Rebecca A. Carter; Eric G. Pamer
      Pages: 32 - 36
      Abstract: Publication date: October 2016
      Source:Anaerobe, Volume 41
      Author(s): Brittany B. Lewis, Rebecca A. Carter, Eric G. Pamer
      Clostridium difficile is an anaerobic bacterium that causes diarrheal illnesses. Disease onset is linked with exposure to oral antibiotics and consequent depletion of secondary bile acids. Here we investigate the relationship between in vitro secondary bile acid tolerance and in vivo disease scores of diverse C. difficile strains in mice.

      PubDate: 2016-09-30T16:09:34Z
      DOI: 10.1016/j.anaerobe.2016.05.010
      Issue No: Vol. 41 (2016)
  • Structural and functional changes within the gut microbiota and
           susceptibility to Clostridium difficile infection
    • Authors: Caná L. Ross; Jennifer K. Spinler; Tor C. Savidge
      Pages: 37 - 43
      Abstract: Publication date: October 2016
      Source:Anaerobe, Volume 41
      Author(s): Caná L. Ross, Jennifer K. Spinler, Tor C. Savidge
      Alteration of the gut microbial community structure and function through antibiotic use increases susceptibility to colonization by Clostridium difficile and other enteric pathogens. However, the mechanisms that mediate colonization resistance remain elusive. As the leading definable cause of infectious diarrhea, toxigenic C. difficile represents a burden for patients and health care systems, underscoring the need for better diagnostics and treatment strategies. Next-generation sequence data has increased our understanding of how the gut microbiota is influenced by many factors including diet, disease, aging and drugs. However, a microbial-based biomarker differentiating C. difficile infection from antibiotic-associated diarrhea has not been identified. Metabolomics profiling, which is highly responsive to changes in physiological conditions, have shown promise in differentiating subtle disease phenotypes that exhibit a nearly identical microbiome community structure, suggesting metabolite-based biomarkers may be an ideal diagnostic for identifying patients with CDI. This review focuses on the current understanding of structural and functional changes to the gut microbiota during C. difficile infection obtained from studies assessing the microbiome and metabolome of samples from patients and murine models.

      PubDate: 2016-09-30T16:09:34Z
      DOI: 10.1016/j.anaerobe.2016.05.006
      Issue No: Vol. 41 (2016)
  • Impact of microbial derived secondary bile acids on colonization
           resistance against Clostridium difficile in the gastrointestinal tract
    • Authors: Jenessa A. Winston; Casey M. Theriot
      Pages: 44 - 50
      Abstract: Publication date: October 2016
      Source:Anaerobe, Volume 41
      Author(s): Jenessa A. Winston, Casey M. Theriot
      Clostridium difficile is an anaerobic, Gram positive, spore-forming bacillus that is the leading cause of nosocomial gastroenteritis. Clostridium difficile infection (CDI) is associated with increasing morbidity and mortality, consequently posing an urgent threat to public health. Recurrence of CDI after successful treatment with antibiotics is high, thus necessitating discovery of novel therapeutics against this pathogen. Susceptibility to CDI is associated with alterations in the gut microbiota composition and bile acid metabolome, specifically a loss of microbial derived secondary bile acids. This review aims to summarize in vitro, ex vivo, and in vivo studies done by our group and others that demonstrate how secondary bile acids affect the different stages of the C. difficile life cycle. Understanding the dynamic interplay of C. difficile and microbial derived secondary bile acids within the gastrointestinal tract will shed light on how bile acids play a role in colonization resistance against C. difficile. Rational manipulation of secondary bile acids may prove beneficial as a treatment for patients with CDI.
      Graphical abstract image

      PubDate: 2016-09-30T16:09:34Z
      DOI: 10.1016/j.anaerobe.2016.05.003
      Issue No: Vol. 41 (2016)
  • Probiotics as adjunctive therapy for preventing Clostridium difficile
           infection – What are we waiting for'
    • Authors: Jennifer K. Spinler; Caná L. Ross; Tor C. Savidge
      Pages: 51 - 57
      Abstract: Publication date: October 2016
      Source:Anaerobe, Volume 41
      Author(s): Jennifer K. Spinler, Caná L. Ross, Tor C. Savidge
      With the end of the golden era of antibiotic discovery, the emergence of a new post-antibiotic age threatens to thrust global health and modern medicine back to the pre-antibiotic era. Antibiotic overuse has resulted in the natural evolution and selection of multi-drug resistant bacteria. One major public health threat, Clostridium difficile, is now the single leading cause of hospital-acquired bacterial infections and is by far the most deadly enteric pathogen for the U.S. population. Due to the high morbidity and mortality and increasing incidence that coincides with antibiotic use, non-traditional therapeutics are ideal alternatives to current treatment methods and also provide an avenue towards prevention. Despite the need for alternative therapies to antibiotics and the safety of most probiotics on the market, researchers are inundated with regulatory issues that hinder the translational science required to push these therapies forward. This review discusses the regulatory challenges of probiotic research, expert opinion regarding the application of probiotics to C. difficile infection and the efficacy of probiotics in preventing this disease.

      PubDate: 2016-09-30T16:09:34Z
      DOI: 10.1016/j.anaerobe.2016.05.007
      Issue No: Vol. 41 (2016)
  • Immune responses induced by Clostridium difficile
    • Authors: Séverine Péchiné; Anne Collignon
      Pages: 68 - 78
      Abstract: Publication date: October 2016
      Source:Anaerobe, Volume 41
      Author(s): Séverine Péchiné, Anne Collignon
      The spectrum of Clostridium difficile infections is highly variable, ranging from asymptomatic carriage to fatal colitis depending on the strain virulence and on the host, its gut microbiota and its immune response. After disruption of the gut microbiota, C. difficile pathogenesis can be divided into three steps: 1) contamination by spores and their germination; 2) multiplication of vegetative cells and intestinal colonization using colonization factors; 3) production of the toxins TcdA and TcdB, and for some strains, the binary toxin, which are responsible for the clinical signs. Three lines of defense counteract C. difficile. The first line is the epithelial barrier, which is breached by the toxins. Then, a rapid innate immune response follows, which forms the second line of defense. It provides very quick defense reactions against C. difficile but is non-specific and does not confer memory. C. difficile and its virulence factors, the toxins and colonization factors, induce a highly pro-inflammatory response, which can be either beneficial or harmful, but triggers the adaptive immunity as the third line of defense required to control the infectious process. Adaptive immunity provides a highly specific immune response against C. difficile with memory and long lasting immunity. The innate and adaptive immune responses against the toxins and surface components are analyzed as well as their role in disease susceptibility, severity and recurrences.

      PubDate: 2016-09-30T16:09:34Z
      DOI: 10.1016/j.anaerobe.2016.04.014
      Issue No: Vol. 41 (2016)
  • The microbiota and immune response during Clostridium difficile infection
    • Authors: Erica L. Buonomo; William A. Petri
      Pages: 79 - 84
      Abstract: Publication date: October 2016
      Source:Anaerobe, Volume 41
      Author(s): Erica L. Buonomo, William A. Petri
      Clostridium difficile is a gram-positive, spore forming anaerobe that infects the gut when the normal microbiota has been disrupted. C. difficile infection (CDI) is the most common cause of hospital acquired infection in the United States, and the leading cause of death due to gastroenteritis. Patients suffering from CDI have varying symptoms which range from mild diarrhea to pseudomembranous colitis and death. The involvement of the immune response to influence disease severity is just beginning to be investigated. There is evidence that the immune response can facilitate either protective or pathogenic phenotypes, suggesting it plays a multifaceted role during CDI. In addition to the immune response, the microbiota is pivotal in dictating the pathogenesis to CDI. A healthy microbiota effectively inhibits infection by restricting the ability of C. difficile to expand in the colon. Thus, understanding which immune mediators and components of the microbiota play beneficial roles during CDI will be important to future therapeutic developments. This review outlines how the microbiota can modulate specific immune mediators, such as IL-23 and others, to influence disease outcome.

      PubDate: 2016-09-30T16:09:34Z
      DOI: 10.1016/j.anaerobe.2016.05.009
      Issue No: Vol. 41 (2016)
  • Neutrophil-mediated inflammation in the pathogenesis of Clostridium
           difficile infections
    • Authors: Shinsmon Jose; Rajat Madan
      Pages: 85 - 90
      Abstract: Publication date: October 2016
      Source:Anaerobe, Volume 41
      Author(s): Shinsmon Jose, Rajat Madan
      Clostridium difficile is the most important cause of nosocomial infectious diarrhea in the western world. C. difficile infections are a major healthcare burden with approximately 500,000 new cases every year and an estimated annual cost of nearly $1 billion in the U.S. Furthermore, the infections are no longer restricted to health care facilities, and recent studies indicate spread of C. difficile infection to the community as well. The clinical spectrum of C. difficile infection ranges from asymptomatic colonization to severe diarrhea, fulminant colitis and death. This spectrum results from a complex interplay between bacterial virulence factors, the colonic microbiome and the host inflammatory response. The overall vigor of host inflammatory response is believed to be an important determinant of C. difficile disease severity, and a more robust immune response is associated with worse outcomes. Neutrophils are the primary cells that respond to C. difficile invasion and neutrophilic inflammation is the hallmark of C. difficile-associated disease. In this review, we will focus on the role of neutrophils (infiltration to infected tissue, pathogen clearance and resolution of inflammation) in the immuno-pathogenesis of C. difficile-associated disease (CDAD).

      PubDate: 2016-09-30T16:09:34Z
      DOI: 10.1016/j.anaerobe.2016.04.001
      Issue No: Vol. 41 (2016)
  • A roadmap for gene system development in Clostridium
    • Authors: Nigel P. Minton; Muhammad Ehsaan; Christopher M. Humphreys; Gareth T. Little; Jonathan Baker; Anne M. Henstra; Fungmin Liew; Michelle L. Kelly; Lili Sheng; Katrin Schwarz; Ying Zhang
      Pages: 104 - 112
      Abstract: Publication date: October 2016
      Source:Anaerobe, Volume 41
      Author(s): Nigel P. Minton, Muhammad Ehsaan, Christopher M. Humphreys, Gareth T. Little, Jonathan Baker, Anne M. Henstra, Fungmin Liew, Michelle L. Kelly, Lili Sheng, Katrin Schwarz, Ying Zhang
      Clostridium species are both heroes and villains. Some cause serious human and animal diseases, those present in the gut microbiota generally contribute to health and wellbeing, while others represent useful industrial chassis for the production of chemicals and fuels. To understand, counter or exploit, there is a fundamental requirement for effective systems that may be used for directed or random genome modifications. We have formulated a simple roadmap whereby the necessary gene systems maybe developed and deployed. At its heart is the use of ‘pseudo-suicide’ vectors and the creation of a pyrE mutant (a uracil auxotroph), initially aided by ClosTron technology, but ultimately made using a special form of allelic exchange termed ACE (Allele-Coupled Exchange). All mutants, regardless of the mutagen employed, are made in this host. This is because through the use of ACE vectors, mutants can be rapidly complemented concomitant with correction of the pyrE allele and restoration of uracil prototrophy. This avoids the phenotypic effects frequently observed with high copy number plasmids and dispenses with the need to add antibiotic to ensure plasmid retention. Once available, the pyrE host may be used to stably insert all manner of application specific modules. Examples include, a sigma factor to allow deployment of a mariner transposon, hydrolases involved in biomass deconstruction and therapeutic genes in cancer delivery vehicles. To date, provided DNA transfer is obtained, we have not encountered any clostridial species where this technology cannot be applied. These include, Clostridium difficile, Clostridium acetobutylicum, Clostridium beijerinckii, Clostridium botulinum, Clostridium perfringens, Clostridium sporogenes, Clostridium pasteurianum, Clostridium ljungdahlii, Clostridium autoethanogenum and even Geobacillus thermoglucosidasius.

      PubDate: 2016-09-30T16:09:34Z
      DOI: 10.1016/j.anaerobe.2016.05.011
      Issue No: Vol. 41 (2016)
  • The bacteriocin bactofencin A subtly modulates gut microbial populations
    • Authors: Caitriona M. Guinane; Elaine M. Lawton; Paula M. O'Connor; Órla O'Sullivan; Colin Hill; R. Paul Ross; Paul D. Cotter
      Pages: 41 - 49
      Abstract: Publication date: August 2016
      Source:Anaerobe, Volume 40
      Author(s): Caitriona M. Guinane, Elaine M. Lawton, Paula M. O'Connor, Órla O'Sullivan, Colin Hill, R. Paul Ross, Paul D. Cotter
      The diverse and dynamic microbiota of the gastrointestinal tract represents a vast source of bioactive substances. These include bacteriocins, which are antimicrobial peptides with the potential to modulate gut populations to impact positively on human health. Although several gut-derived bacteriocins have been isolated, there remain only a few exceptional studies in which their influence on microbial populations within the gut has been investigated. To facilitate such investigations, in vitro faecal fermentation systems can be used to simulate the anaerobic environment of the colon. In this instance, such a system was employed to explore the impact of bactofencin A, a novel broad spectrum class IId bacteriocin produced by gut isolates of Lactobacillus salivarius, on intestinal populations and overall microbial diversity. The study reveals that, although bactofencin A is a broad spectrum bacteriocin, it has a relatively subtle influence on intestinal communities, with a potentially positive impact on anaerobic populations such as Bacteroides, Clostridium and Bifidibacterium spp. The strategy taken is an important first step in investigating the merits of using bactofencin A to manipulate the gut microbiota in a beneficial way for health.

      PubDate: 2016-06-15T02:04:32Z
      DOI: 10.1016/j.anaerobe.2016.05.001
      Issue No: Vol. 40 (2016)
  • Virulence arsenal of the most pathogenic species among the gram positive
           anaerobic cocci, Finegoldia magna
    • Authors: Lyudmila Boyanova; Rumyana Markovska; Ivan Mitov
      Abstract: Publication date: Available online 15 October 2016
      Author(s): Lyudmila Boyanova, Rumyana Markovska, Ivan Mitov
      This review focuses on the virulence arsenal of the most pathogenic species among Gram positive anaerobic cocci, Finegoldia magna according to recently published data from 2012-2016. Virulence factors like sortase dependent pili and F. magna adhesion factor (FAF) facilitate the start of the infection. Albumin binding protein (PAB) enhances F. magna survival. FAF, subtilisin-like extracellular serine protease (SufA) and superantigen protein L protect the bacteria from factors of innate defense system. SufA, capsule and tissue-destroying enzymes provide a deep penetration or spread of the infections and the protein L is associated with infection severity. Biofilm production results in infection chronification and complicated treatment as well as to persistence of multi-species biofilms. Resistance rates to quinolones (13.0->70%) and clindamycin (0–40.0%) are important, and resistance to penicillins (<4%), chloramphenicol (7.0%) and metronidazole (<7%) has been reported. F. magna should not be overlooked when present in monoinfections or mixed infections in humans.

      PubDate: 2016-10-16T17:27:26Z
      DOI: 10.1016/j.anaerobe.2016.10.007
  • Distribution of Clostridium difficile PCR ribotypes and high proportion of
           027 and 176 in some hospitals in four South Eastern European countries
    • Authors: Maja Rupnik; Arjana Tambic Andrasevic; Elena Trajkovska Dokic; Ivanka Matas; Milica Jovanovic; Selma Pasic; Aleksander Kocuvan; Sandra Janezic
      Abstract: Publication date: Available online 15 October 2016
      Author(s): Maja Rupnik, Arjana Tambic Andrasevic, Elena Trajkovska Dokic, Ivanka Matas, Milica Jovanovic, Selma Pasic, Aleksander Kocuvan, Sandra Janezic
      While Clostridium difficile epidemiology is well documented in many European countries, data are largely missing for South Eastern European region. Here we report the PCR ribotype distribution of 249 C. difficile isolates received for typing from six hospital settings from Croatia, Bosnia and Herzegovina, Republic of Macedonia and Serbia in time period from 2008 to 2015. Twenty-four PCR ribotypes were detected. The majority of strains from Bosnia and Herzegovina and Serbia belonged to PCR ribotype 027 (65.8%). Other three dominating PCR ribotypes were 176 (18 strains; Croatia), 001/072 (15 strains; all countries) and 014/020 (15 strains; all countries).

      PubDate: 2016-10-16T17:27:26Z
      DOI: 10.1016/j.anaerobe.2016.10.005
  • Effect of smokeless tobacco products on human oral bacteria growth and
    • Authors: Min Liu; Jinshan Jin; Hongmiao Pan; Jinhui Feng; Carl E. Cerniglia; Maocheng Yang; Huizhong Chen
      Abstract: Publication date: Available online 15 October 2016
      Author(s): Min Liu, Jinshan Jin, Hongmiao Pan, Jinhui Feng, Carl E. Cerniglia, Maocheng Yang, Huizhong Chen
      To evaluate the toxicity of smokeless tobacco products (STPs) on oral bacteria, seven smokeless tobacco aqueous extracts (STAEs) from major brands of STPs and three tobacco-specific N-nitrosamines (TSNAs) were used in a growth and viability test against 38 oral bacterial species or subspecies. All seven STAEs showed concentration-dependent effects on the growth and viability of tested oral bacteria under anaerobic culture conditions, although there were strain-to-strain variations. In the presence of 1 mg/ml STAEs, the growth of 4 strains decreased over 0.32–2.14 log10 fold, while 14 strains demonstrated enhanced growth of 0.3–1.76 log10 fold, and the growth of 21 strains was not significantly affected. In the presence of 10 mg/ml STAEs, the growth of 17 strains was inhibited 0.3–2.11 log10 fold, 18 strains showed enhanced growth of 0.3–0.97 log10 fold, and 4 strains were not significantly affected. In the presence of 50 mg/ml STAEs, the growth of 32 strains was inhibited 0.3–2.96 log10 fold, 8 strains showed enhanced growth of 0.3–1.0 log10 fold, and 2 strains were not significantly affected. All seven STAEs could promote the growth of 4 bacterial strains, including Eubacterium nodatum, Peptostreptococcus micros, Streptococcus anginosus, and Streptococcus constellatus. Exposure to STAEs modulated the viability of some bacterial strains, with 21.1–66.5% decrease for 4 strains at 1 mg/ml, 20.3–85.7% decrease for 10 strains at 10 mg/ml, 20.0–93.3% decrease for 27 strains at 50 mg/ml, and no significant effect for 11 strains at up to 50 mg/ml. STAEs from snuffs inhibited more tested bacterial strains than those from snus indicating that the snuffs may be more toxic to the oral bacteria than snus. For TSNAs, cell growth and viability of 34 tested strains were not significantly affected at up to 100 μg/ml; while the growth of P. micros was enhanced 0.31–0.54 log10 fold; the growth of Veillonella parvula was repressed 0.33–0.36 log10 fold; and the cell viabilities of 2 strains decreased 56.6–69.9%. The results demonstrate that STAEs affected the growth of some types of oral bacteria, which may affect the healthy ecological balance of oral bacteria in humans. On the other hand, TSNAs did not significantly affect the growth of the oral bacteria.

      PubDate: 2016-10-16T17:27:26Z
      DOI: 10.1016/j.anaerobe.2016.10.006
  • The effect of quercetin on genetic expression of the commensal gut
           microbes Bifidobacterium catenulatum, Enterococcus caccae and Ruminococcus
    • Authors: Jenni Firrman; LinShu Liu; Liqing Zhang; Gustavo Arango Argoty; Minqian Wang; Peggy Tomasula; Masuko Kobori; Sherri Pontious; Weidong Xiao
      Abstract: Publication date: Available online 11 October 2016
      Author(s): Jenni Firrman, LinShu Liu, Liqing Zhang, Gustavo Arango Argoty, Minqian Wang, Peggy Tomasula, Masuko Kobori, Sherri Pontious, Weidong Xiao
      Quercetin is one of the most abundant polyphenols found in fruits and vegetables. The ability of the gut microbiota to metabolize quercetin has been previously documented; however, the effect that quercetin may have on commensal gut microbes remains unclear. In the present study, the effects of quercetin on the commensal gut microbes Ruminococcus gauvreauii, Bifidobacterium catenulatum and Enterococcus caccae were determined through evaluation of growth patterns and cell morphology, and analysis of genetic expression profiles between quercetin treated and non-treated groups using Single Molecule RNA sequencing via Helicos technology. Results of this study revealed that phenotypically, quercetin did not prevent growth of Ruminococcus gauvreauii, mildly suppressed growth of Bifidobacterium catenulatum, and moderately inhibited growth of Enterococcus caccae. Genetic analysis revealed that in response to quercetin, Ruminococcus gauvreauii down regulated genes responsible for protein folding, purine synthesis and metabolism. Bifidobacterium catenulatum increased expression of the ABC transport pathway and decreased metabolic pathways and cell wall synthesis. Enterococcus caccae upregulated genes responsible for energy production and metabolism, and downregulated pathways of stress response, translation and sugar transport. For the first time, the effect of quercetin on the growth and genetic expression of three different commensal gut bacteria was documented. The data provides insight into the interactions between genetic regulation and growth. This is also a unique demonstration of how RNA single molecule sequencing can be used to study the gut microbiota.

      PubDate: 2016-10-13T17:09:25Z
      DOI: 10.1016/j.anaerobe.2016.10.004
  • Transcriptomic analysis of Propionibacterium acnes biofilms in vitro
    • Authors: Anika C. Jahns; Hinnerk Eilers; Oleg A. Alexeyev
      Abstract: Publication date: Available online 7 October 2016
      Author(s): Anika C. Jahns, Hinnerk Eilers, Oleg A. Alexeyev
      Propionibacterium acnes is a well-known commensal of the human skin connected to acne vulgaris and joint infections. It is extensively studied in planktonic cultures in the laboratory settings but occurs naturally in biofilms. In this study we have developed an in vitro biofilm model of P. acnes and studied growth features, matrix composition, matrix penetration by fluorescent-labelled antibiotics as well as gene expression. Antibiotic susceptibility of biofilms was studied and could be enhanced by increased glucose concentrations. Biofilm cells were characterized by up-regulated stress-induced genes and up-regulation of genes coding for the potential virulence-associated CAMP factors. P. acnes can generate persister cells showing a reversible tolerance to 50 fold MIC of common antibiotics.

      PubDate: 2016-10-13T17:09:25Z
      DOI: 10.1016/j.anaerobe.2016.10.001
  • In-vitro activity of solithromycin against anaerobic bacteria from the
           normal intestinal microbiota
    • Authors: Andrej Weintraub; Mamun-Ur Rashid; Carl Erik Nord
      Abstract: Publication date: Available online 7 October 2016
      Author(s): Andrej Weintraub, Mamun-Ur Rashid, Carl Erik Nord
      Solithromycin is a novel fluoroketolide with high activity against bacteria associated with community-acquired respiratory tract infections as well as gonorrhea. However, data on the activity of solithromycin against anaerobic bacteria from the normal intestinal microbiota are scarce. In this study, 1024 Gram-positive and Gram-negative anaerobic isolates from the normal intestinal microbiota were analyzed for in-vitro susceptibility against solithromycin and compared to azithromycin, amoxicillin/clavulanic acid, ceftriaxone, metronidazole and levofloxacin by determining the minimum inhibitory concentration (MIC). Solithromycin was active against Bifidobacteria (MIC50, 0.008 mg/L) and Lactobacilli (MIC50, 0.008 mg/L). The MIC50 for Clostridia, Bacteroides, Prevotella and Veillonella were 0.5, 0.5, 0.125 and 0.016 mg/L, respectively. Gram-positive anaerobes were more susceptible to solithromycin as compared to the other antimicrobials tested. The activity of solithromycin against Gram-negative anaerobes was equal or higher as compared to other tested agents.

      PubDate: 2016-10-13T17:09:25Z
      DOI: 10.1016/j.anaerobe.2016.10.002
  • Characterization of Clostridium difficile PCR-ribotype 018: A problematic
           emerging type
    • Authors: Fabrizio Barbanti; Patrizia Spigaglia
      Abstract: Publication date: Available online 7 October 2016
      Author(s): Fabrizio Barbanti, Patrizia Spigaglia
      Recent surveys indicate that the majority of toxigenic Clostridium difficile strains isolated in European hospitals belonged to PCR-ribotypes (RTs) different from RT 027 or RT 078. Among these types, RT 018 has been reported in Italy and, more recently, in Korea and Japan. In Italy, strains RT 018 have become predominant in the early 2000s, whereas the majority of strains isolated before were RT 126, a type belonging to the same lineage as the RT 078. In this study, we have found that Italian strains RT 018 are resistant to erythromycin, clindamycin, moxifloxacin and rifampicin. Rifampicin resistance is rarely observed in strains RT 018 from other countries and in Italian strains RT 078 and RT 126, therefore the decennial use of rifamycin antibiotics in Italy may be one of the driving factors for the spread of RT 018 in our country. The strains RT 018 examined showed a significant higher adhesion to Caco-2 cells compared to strains RT 078 and RT 126. Furthermore, strains RT 018 became predominant in in vitro competition assays with strains RT 078 or RT 126. If maintained in vivo, these characteristics could lead to a rapid colonization of the intestine by strains RT 018. Under the conditions used, isolates RT 018 produced significantly higher toxins levels compared to strains RT 078 and RT 126, while heat-resistant CFUs production seems to be strain-dependent. Robust toxin production and enhanced sporulation could in part explain the high diffusion and interpatient transmissibility observed for strains RT 018 in the hospital environment. In conclusion, the characteristics observed in the Italian isolates RT 018 seem to contribute in conferring an adaptive advantage to these strains, allowing their successful spread in our country.

      PubDate: 2016-10-13T17:09:25Z
      DOI: 10.1016/j.anaerobe.2016.10.003
  • The unappreciated in vitro activity of tedizolid against Bacteroides
           fragilis species, including strains resistant to metronidazole and
    • Authors: Ellie J.C. Goldstein; Diane M. Citron; Kerin L. Tyrrell; Elisa Leoncio; C. Vreni Merriam
      Abstract: Publication date: Available online 3 October 2016
      Author(s): Ellie J.C. Goldstein, Diane M. Citron, Kerin L. Tyrrell, Elisa Leoncio, C. Vreni Merriam
      The comparative in vitro activity of tedizolid against 124 Bacteroides group species isolates, including carbapenem, metronidazole and piperacillin-tazobactam resistant strains, had an MIC90 of 2 μg/ml (range, 0.5–4 μg/ml) and was 1–4 times more active than linezolid that had an MIC90 of 8 μg/ml (range, 2–16 μg/ml).

      PubDate: 2016-10-06T16:39:29Z
      DOI: 10.1016/j.anaerobe.2016.09.008
  • Evaluation of MALDI-TOF MS (Matrix-Assisted Laser Desorption-Ionization
           Time-of-Flight Mass Spectrometry) for routine identification of anaerobic
    • Authors: Belén Rodríguez-Sánchez; Luis Alcalá; Mercedes Marín; Adrián Ruiz; Elena Alonso; Emilio Bouza
      Abstract: Publication date: Available online 1 October 2016
      Author(s): Belén Rodríguez-Sánchez, Luis Alcalá, Mercedes Marín, Adrián Ruiz, Elena Alonso, Emilio Bouza
      Information regarding the use of MALDI-TOF MS as an alternative to conventional laboratory methods for the rapid and reliable identification of bacterial isolates is still limited. In this study, MALDI-TOF MS was evaluated on 295 anaerobic isolates previously identified by 16S rRNA gene sequencing and with biochemical tests (Rapid ID 32A system, BioMérieux). In total, 85.8% of the isolates were identified by MALDI-TOF MS at the species level vs 49.8% using the Rapid ID 32A system (p < 0.0001). None of the isolates was discordantly identified at the genus level using MALDI-TOF MS and only 9 of them could not be identified using the method. Thus, our results show that MALDI-TOF MS is a robust and reliable tool for the identification of anaerobic isolates in the microbiology laboratory. Its implementation will reduce the turnaround time for a final identification and the number of isolates that require 16S rRNA sequencing.

      PubDate: 2016-10-06T16:39:29Z
      DOI: 10.1016/j.anaerobe.2016.09.009
  • Introduction
    • Abstract: Publication date: October 2016
      Source:Anaerobe, Volume 41

      PubDate: 2016-09-30T16:09:34Z
  • Bypass graft infection and bacteremia caused by Anaerostipes caccae: First
           report of human infection caused by a recently described gut anaerobe
    • Authors: Meklit Workneh; Frances Wang; Mark Romagnoli; Patricia J. Simner; Karen Carroll
      Abstract: Publication date: Available online 28 September 2016
      Author(s): Meklit Workneh, Frances Wang, Mark Romagnoli, Patricia J. Simner, Karen Carroll
      We report a case of bypass graft infection and bacteremia caused by Anaerostipes caccae. A review of the literature shows no reported human infection caused by this microorganism to date. The patient was initially treated with vancomycin and piperacillin-tazobactam on admission and with amoxicillin-clavulanate upon discharge. The slow-growing organism was subsequently found to be susceptible to metronidazole and ertapenem.

      PubDate: 2016-09-30T16:09:34Z
      DOI: 10.1016/j.anaerobe.2016.09.005
  • The role of Fusobacterium necrophorum in pharyngotonsillitis – A
    • Authors: Karin Holm; Steffen Bank; Hanne Nielsen; Lena Hagelskjær Kristensen; Jørgen Prag; Anders Jensen
      Abstract: Publication date: Available online 28 September 2016
      Author(s): Karin Holm, Steffen Bank, Hanne Nielsen, Lena Hagelskjær Kristensen, Jørgen Prag, Anders Jensen
      Fusobacterium necrophorum is a gram-negative anaerobic bacterium that is the causative agent of the invasive disease Lemierre's syndrome. In addition, it is also associated with peritonsillar abscess formation and otitis media in small children. Recent research has shown that F. necrophorum may be involved in pharyngotonsillitis especially in adolescent and young adults and that it may be the second most common bacterial cause of pharyngotonsillitis after Streptococcus pyogenes (Group A streptococci). Peritonsillar abscesses and Lemierre's syndrome due to F. necrophorum are also found in this age group, suggesting that they may be complications of F. necrophorum pharyngotonsillitis. In this review we present the present knowledge about the role of F. necrophorum in pharyngotonsillitis with special emphasis on the age distribution. We argue that F. necrophorum is an important pathogen involved in pharyngotonsillitis in the age group of 13–40 years of age and we urge clinical microbiology labs to set up the appropriate techniques to be able to detect F. necrophorum from throat swabs.

      PubDate: 2016-09-30T16:09:34Z
      DOI: 10.1016/j.anaerobe.2016.09.006
  • Clostridium difficile: A rare cause of pyogenic liver abscess
    • Authors: Nurver Ulger Toprak; Gulcin Balkose; Deniz Durak; Ender Dulundu; Tolga Demirbaş; Cumhur Yegen; Guner Soyletir
      Abstract: Publication date: Available online 28 September 2016
      Author(s): Nurver Ulger Toprak, Gulcin Balkose, Deniz Durak, Ender Dulundu, Tolga Demirbaş, Cumhur Yegen, Guner Soyletir
      Extra-intestinal infections due to Clostridium difficile have been reported rarely. Herein we report a case of pyogenic liver abscess from toxigenic C. difficile in an 80-year-old non-hospitalized woman with diabetes mellitus, cerebrovascular and cardiovascular diseases. The patient was admitted to the emergency department with fever and abdominal pain. There was no history of diarrhea or use of antibiotics. Laboratory parameters revealed signs of inflammation and elevated AST and ALT levels. Abdominal ultrasound and computer tomography showed multiple focal lesions in the bilateral liver lobes and hydropic gallbladder with stones. The patient underwent cholecystectomy and the liver abscesses were drained. Toxigenic C. difficile strains were isolated from the drained pus and also from the stool sample. According to repetitive-element PCR (rep-PCR) analyses both organisms were the same. The organisms were susceptible to antibiotics. Despite proper antibiotic therapy and surgical drainage, the patient succumbed to her illness.

      PubDate: 2016-09-30T16:09:34Z
      DOI: 10.1016/j.anaerobe.2016.09.007
  • Counterselection employing mutated pheS for markerless genetic deletion in
           Bacteroides species
    • Authors: Yasuhiro Kino; Haruyuki Nakayama-Imaohji; Masashi Fujita; Ayano Tada; Saori Yoneda; Kazuya Murakami; Masahito Hashimoto; Tetsuya Hayashi; Katsuichiro Okazaki; Tomomi Kuwahara
      Abstract: Publication date: Available online 14 September 2016
      Author(s): Yasuhiro Kino, Haruyuki Nakayama-Imaohji, Masashi Fujita, Ayano Tada, Saori Yoneda, Kazuya Murakami, Masahito Hashimoto, Tetsuya Hayashi, Katsuichiro Okazaki, Tomomi Kuwahara
      Markerless gene deletion is necessary for multiple gene disruptions due to the limited number of antibiotic resistant markers for some bacteria. However, even in transformable strains, obtaining the expected mutation without a marker requires laborious screening of a large number of colonies. Previous studies had success in various bacteria with a counter-selection system where a conditional lethal gene was incorporated into the vector. We examined the efficacy of the mutated pheS gene (pheS*) as a counter-selective marker for gene deletion in Bacteroides. This mutation produces an amino acid substitution (A303G) in the alpha subunit of Bacteroides phenylalanyl tRNA synthetase, which in E. coli alters the specificity of the tRNA synthetase resulting in a conditional lethal mutation due to the incorporation of p-chloro-phenylalanine (p-Cl-Phe) into protein. B. fragilis YCH46 and B. thetaiotaomicron VPI-5482 transformed with a pheS*-harboring shuttle vector were clearly growth-inhibited in the presence of >5 mM p-Cl-Phe in liquid defined minimal media (DMM) and on DMM agar plates. A targeting plasmid was constructed to delete the genetic region for capsular polysaccharide PS2 in B. fragilis or PS1 in B. thetaiotaomicron. After counterselection, p-Cl-Phe-resistant colonies were generated at a frequency of 8.1 × 10−3 for B. fragilis and 1.7 × 10−3 for B. thetaiotaomicron. Of the p-Cl-Phe-resistant colonies, 4.2% and 72% harbored the correct genetic deletion for B. fragilis and B. thetaiotaomicron, respectively. These results indicate that mutated pheS is a useful counter-selective gene to construct markerless genetic deletions in Bacteroides.

      PubDate: 2016-09-15T15:08:41Z
      DOI: 10.1016/j.anaerobe.2016.09.004
  • A case of Bacteroides pyogenes bacteremia secondary to liver abscess
    • Authors: Jong Eun Park; So-Young Park; Dong Joon Song; Hee Jae Huh; Chang-Seok Ki; Kyong Ran Peck; Nam Yong Lee
      Abstract: Publication date: Available online 8 September 2016
      Author(s): Jong Eun Park, So-Young Park, Dong Joon Song, Hee Jae Huh, Chang-Seok Ki, Kyong Ran Peck, Nam Yong Lee
      Bacteroides pyogenes, a non-spore-forming, anaerobic, gram-negative rod, is a component of the oral flora of animals and has, on occasion, been reported to cause human infection through dog or cat bites. We report the first case of B. pyogenes bacteremia secondary to liver abscess with no history of an animal bite. The microorganism was identified by 16S rRNA sequencing.

      PubDate: 2016-09-10T14:55:45Z
      DOI: 10.1016/j.anaerobe.2016.09.002
  • The role of the bacterial microbiota on reproductive and pregnancy health
    • Authors: Deborah B. Nelson; L. Christie Rockwell; Morgan D. Prioleau; Laura Goetzl
      Abstract: Publication date: Available online 6 September 2016
      Author(s): Deborah B. Nelson, L. Christie Rockwell, Morgan D. Prioleau, Laura Goetzl
      Recent assessments have examined the composition of bacterial communities influencing reproductive, pregnancy and infant health. The Microbiome Project has made great strides in sequencing the microbiome and identifying the vast communities of microorganisms that inhabit our bodies and much work continues to examine the individual contribution of bacteria on health and disease to inform future therapies. This review explores the current literature outlining the contribution of important bacteria on reproductive health among sexually active men and women, outlines gaps in current research to determine causal and interventional relationships, and suggests future research initiatives. Novel treatments options to reduce adverse outcomes must recognize the heterogeneity of the bacteria within the microbiome and adequately assess long-term benefits in reducing disease burden and re-establishing a healthy Lactobacillus-dominant state. Recognizing other reservoirs outside of the lower genital track and within sexual partners as well as genetic and individual moderators may be most important for long-term cure and reduction of disease. It will be important to develop useful screening tools and comprehensively examine novel therapeutic options to promote the long-term reduction of high-risk bacteria and the re-establishment of healthy bacterial levels to considerably improve outcomes among pregnant women and sexually active men and women.

      PubDate: 2016-09-10T14:55:45Z
      DOI: 10.1016/j.anaerobe.2016.09.001
  • First case report of a human sepsis involving a recently identified
           anaerobic agent: Bacteroides faecis
    • Authors: M. Garcia; P. Bouvet; F. Petitpas; C. Jayle; C. Legeay; J. Sautereau; A. Michaud; C. Burucoa; C. Plouzeau
      Abstract: Publication date: Available online 18 August 2016
      Author(s): M. Garcia, P. Bouvet, F. Petitpas, C. Jayle, C. Legeay, J. Sautereau, A. Michaud, C. Burucoa, C. Plouzeau
      Up until now, Bacteroides faecis, a Gram-negative, anaerobic, non-motile, nonsporeforming rod has been principally described as a commensal microbe isolated from the feces of healthy adults. We report the first case of human Bacteroides faecis sepsis after removal of suspected post-colonic ischemia colonized epicardic electrodes. Electrodes and blood cultures both grew Gram-negative anaerobic rods but usual phenotypic methods and 16S rARN gene sequencing failed to ensure its species identification. B. faecis was finally identified using hsp60 gene sequencing. Because this species is not well-known and is difficult to identify, it may have been overlooked or misidentified in previous studies.

      PubDate: 2016-08-21T13:47:36Z
      DOI: 10.1016/j.anaerobe.2016.08.004
  • Tetanus toxin production is triggered by the transition from amino acid
           consumption to peptides
    • Authors: Cuauhtemoc Licona-Cassani; Jennifer A. Steen; Nicolas E. Zaragoza; Glenn Moonen; George Moutafis; Mark P. Hodson; John Power; Lars K. Nielsen; Esteban Marcellin
      Abstract: Publication date: Available online 1 August 2016
      Author(s): Cuauhtemoc Licona-Cassani, Jennifer A. Steen, Nicolas E. Zaragoza, Glenn Moonen, George Moutafis, Mark P. Hodson, John Power, Lars K. Nielsen, Esteban Marcellin
      Bacteria produce some of the most potent molecules known, of which many cause serious diseases such as tetanus. For prevention, billions of people and countless animals are immunised with the highly effective vaccine, industrially produced by large-scale fermentation. However, toxin production is often hampered by low yields and batch-to-batch variability. Improved productivity has been constrained by a lack of understanding of the molecular mechanisms controlling toxin production. Here we have developed a reproducible experimental framework for screening phenotypic determinants in Clostridium tetani under a process that mimics an industrial setting. We show that amino acid depletion induces production of the toxin. Using time-course transcriptomics and extracellular metabolomics to generate a ‘fermentation atlas’ that ascribe growth behaviour, nutrient consumption and gene expression to the fermentation phases, we found a subset of preferred amino acids. Exponential growth is characterised by the consumption of those amino acids followed by a slower exponential growth phase where peptides are consumed, and toxin is produced. The results aim at assisting in fermentation medium design towards the improvement of vaccine production yields and reproducibility. In conclusion, our work not only provides deep fermentation dynamics but represents the foundation for bioprocess design based on C. tetani physiological behaviour under industrial settings.

      PubDate: 2016-08-03T12:28:56Z
      DOI: 10.1016/j.anaerobe.2016.07.006
  • Induction of antitoxin responses in Clostridium-difficile-infected
           patients compared to healthy blood donors
    • Authors: Alice von Eichel-Streiber; Wonbeom Paik; Katherine Knight; Karina Gisch; Karolina Nadjafi; Christine Decker; Oliver Bosnjak; Adam Cheknis; Stuart Johnson; Christoph von Eichel-Streiber
      Abstract: Publication date: Available online 15 July 2016
      Author(s): Alice von Eichel-Streiber, Wonbeom Paik, Katherine Knight, Karina Gisch, Karolina Nadjafi, Christine Decker, Oliver Bosnjak, Adam Cheknis, Stuart Johnson, Christoph von Eichel-Streiber
      According to the literature Clostridium difficile antitoxins are present in up to 66% of humans. In a survey of ∼400 plasma samples from healthy blood donors we found that less than 6% were positive for anti-TcdA or anti-TcdB antitoxins. Using the same standard immunoassay protocol, we looked for IgG and IgA antitoxins in the blood and stool samples from 25 patients with C. difficile infection (CDI). Some patients with CDI had no antitoxin detected at all, while others had high levels of specific IgG- and IgA-antitoxins against both TcdA and TcdB in blood and IgA-anti-TcdA and -anti-TcdB antibodies in stool. Systemic responses to TcdB and mucosal responses to TcdA predominated. Among patients infected with the NAP1/027/BI strain, systemic IgG-anti-TcdB responses were particularly elevated. In contrast, patients infected with non-027 strains had more elevated mucosal IgA-anti-TcdA responses. Furthermore, high titer sera did not correlate with high neutralizing potential. We hypothesize that paradoxical killing of primed B-cells by antibody-mediated endosomal uptake of the Large Clostridial Toxins, TcdA and TcdB leads to clonal elimination of the fittest B-cells. If this hypothesis is confirmed, immune suppression rather than protective humoral immunity might be the consequence in some patients infected with toxigenic C. difficile.
      Graphical abstract image

      PubDate: 2016-07-24T11:57:37Z
      DOI: 10.1016/j.anaerobe.2016.07.001
  • New insights into Clostridium perfringens epsilon toxin activation and
           action on the brain during enterotoxemia
    • Authors: John C. Freedman; Bruce A. McClane; Francisco A. Uzal
      Abstract: Publication date: Available online 16 June 2016
      Author(s): John C. Freedman, Bruce A. McClane, Francisco A. Uzal
      Epsilon toxin (ETX), produced by Clostridium perfringens types B and D, is responsible for diseases that occur mostly in ruminants. ETX is produced in the form of an inactive prototoxin that becomes proteolytically-activated by several proteases. A recent ex vivo study using caprine intestinal contents demonstrated that ETX prototoxin is processed in a step-wise fashion into a stable, active ∼27 kDa band on SDS-PAGE. When characterized further by mass spectrometry, the stable ∼27 kDa band was shown to contain three ETX species with varying C-terminal residues; each of these ETX species is cytotoxic. This study also demonstrated that, in addition to trypsin and chymotrypsin, proteases such as carboxypeptidases are involved in processing ETX prototoxin. Once absorbed, activated ETX species travel to several internal organs, including the brain, where this toxin acts on the vasculature to cross the blood-brain barrier, produces perivascular edema and affects several types of brain cells including neurons, astrocytes, and oligodendrocytes. In addition to perivascular edema, affected animals show edema within the vascular walls. This edema separates the astrocytic end-feet from affected blood vessels, causing hypoxia of nervous system tissue. Astrocytes of rats and sheep affected by ETX show overexpression of aquaporin-4, a membrane channel protein that is believed to help remove water from affected perivascular spaces in an attempt to resolve the perivascular edema. Amyloid precursor protein, an early astrocyte damage indicator, is also observed in the brains of affected sheep. These results show that ETX activation in vivo seems to be more complex than previously thought and this toxin acts on the brain, affecting vascular permeability, but also damaging neurons and other cells.

      PubDate: 2016-06-18T18:01:24Z
      DOI: 10.1016/j.anaerobe.2016.06.006
  • Development of SYN-004, an oral beta-lactamase treatment to protect the
           gut microbiome from antibiotic-mediated damage and prevent Clostridium
           difficile infection
    • Authors: Michael Kaleko; J. Andrew Bristol; Steven Hubert; Todd Parsley; Giovanni Widmer; Saul Tzipori; Poorani Subramanian; Nur Hasan; Perrti Koski; John Kokai-Kun; Joseph Sliman; Annie Jones; Sheila Connelly
      Abstract: Publication date: Available online 2 June 2016
      Author(s): Michael Kaleko, J. Andrew Bristol, Steven Hubert, Todd Parsley, Giovanni Widmer, Saul Tzipori, Poorani Subramanian, Nur Hasan, Perrti Koski, John Kokai-Kun, Joseph Sliman, Annie Jones, Sheila Connelly
      The gut microbiome, composed of the microflora that inhabit the gastrointestinal tract and their genomes, make up a complex ecosystem that can be disrupted by antibiotic use. The ensuing dysbiosis is conducive to the emergence of opportunistic pathogens such as Clostridium difficile. A novel approach to protect the microbiome from antibiotic-mediated dysbiosis is the use of beta-lactamase enzymes to degrade residual antibiotics in the gastrointestinal tract before the microflora are harmed. Here we present the preclinical development and early clinical studies of the beta-lactamase enzymes, P3A, currently referred to as SYN-004, and its precursor, P1A. Both P1A and SYN-004 were designed as orally-delivered, non-systemically available therapeutics for use with intravenous beta-lactam antibiotics. SYN-004 was engineered from P1A, a beta-lactamase isolated from Bacillus licheniformis, to broaden its antibiotic degradation profile. SYN-004 efficiently hydrolyses penicillins and cephalosporins, the most widely used IV beta-lactam antibiotics. In animal studies, SYN-004 degraded ceftriaxone in the GI tract of dogs and protected the microbiome of pigs from ceftriaxone-induced changes. Phase I clinical studies demonstrated SYN-004 safety and tolerability. Phase 2 studies are in progress to assess the utility of SYN-004 for the prevention of antibiotic-associated diarrhea and Clostridium difficile disease.

      PubDate: 2016-06-15T02:04:32Z
      DOI: 10.1016/j.anaerobe.2016.05.015
  • Gene regulation by the VirS/VirR system in Clostridium perfringens
    • Authors: Kaori Ohtani
      Abstract: Publication date: Available online 11 June 2016
      Author(s): Kaori Ohtani
      The Gram-positive anaerobic spore-forming rod, Clostridium perfringens, is widely distributed in nature, especially in soil and the gastrointestinal tract of humans and animals. C. perfringens produces many secreted toxins and enzymes that are involved in the pathogenesis of gas gangrane and gastrointestinal disease. One of the most important systems regulating the production of these proteins in C. perfringens is the VirS/VirR-VR-RNA signal transduction cascade. The Agr system also important for the regulation of toxin genes. VirS appears to sense the peptide produced by the Agr (accessory gene regulator) system. The VirS/VirR-VR-RNA cascade controls the pathogenesis of C. perfringens infections by regulating virulence related genes and genes for energy metabolism. These systems are important for the host cell-induced upregulation of toxin production.

      PubDate: 2016-06-15T02:04:32Z
  • Zoonotic potential of the Clostridium difficile RT078 family in Taiwan
    • Authors: Bo-Yang Tsai; Wen-Chien Ko; Ter-Hsin Chen; Ying-Chen Wu; Po-Han Lan; Yi-Hsuan Chen; Yuan-Pin Hung; Pei-Jane Tsai
      Abstract: Publication date: Available online 9 June 2016
      Author(s): Bo-Yang Tsai, Wen-Chien Ko, Ter-Hsin Chen, Ying-Chen Wu, Po-Han Lan, Yi-Hsuan Chen, Yuan-Pin Hung, Pei-Jane Tsai
      Clostridium difficile is the major cause of nosocomial diarrhea. We have previously demonstrated that in southern Taiwan, severe C. difficile-associated diarrhea (CDAD) cases were due to the C. difficile RT 126 strain infection, indicating the arrival of an epidemic C. difficile clone in southern Taiwan. RT126 has a close genetic relationship with RT078. However, the RT078 family is the predominant strain of C. difficile in animals worldwide, particularly in swine. In this study, we surveyed C. difficile strains isolated from swine at several farms in Taiwan from August 2011 to March 2015. We found that all swine strains, namely RT078 (32.5%, 37 of 114), RT126 (28.9%, 33 of 114) and RT127 (37.7%, 43 of 114), belonged to the toxigenic RT078 family. All strains had high gyrA mutation rate (57.9%, 66/114), which was linked to quinolone resistance. Notably, Rep-PCR revealed that 3 RT078 animal strains had the same fingerprint as human RT078 clinical isolates; their phylogenic relationship was closely related to the whole gene sequences of tcdB, thus suggesting zoonotic potential for C. difficile infection in Taiwan.

      PubDate: 2016-06-15T02:04:32Z
      DOI: 10.1016/j.anaerobe.2016.06.002
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