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Publisher: Elsevier   (Total: 3043 journals)

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Showing 1 - 200 of 3043 Journals sorted alphabetically
AASRI Procedia     Open Access   (Followers: 15)
Academic Pediatrics     Hybrid Journal   (Followers: 20, SJR: 1.402, h-index: 51)
Academic Radiology     Hybrid Journal   (Followers: 18, SJR: 1.008, h-index: 75)
Accident Analysis & Prevention     Partially Free   (Followers: 83, SJR: 1.109, h-index: 94)
Accounting Forum     Hybrid Journal   (Followers: 23, SJR: 0.612, h-index: 27)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 27, SJR: 2.515, h-index: 90)
Achievements in the Life Sciences     Open Access   (Followers: 4)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 5, SJR: 0.338, h-index: 19)
Acta Astronautica     Hybrid Journal   (Followers: 331, SJR: 0.726, h-index: 43)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
Acta Biomaterialia     Hybrid Journal   (Followers: 25, SJR: 2.02, h-index: 104)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription   (Followers: 1)
Acta de Investigación Psicológica     Open Access   (Followers: 2)
Acta Ecologica Sinica     Open Access   (Followers: 8, SJR: 0.172, h-index: 29)
Acta Haematologica Polonica     Free   (SJR: 0.123, h-index: 8)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.604, h-index: 38)
Acta Materialia     Hybrid Journal   (Followers: 211, SJR: 3.683, h-index: 202)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5, SJR: 0.615, h-index: 21)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.442, h-index: 21)
Acta Oecologica     Hybrid Journal   (Followers: 9, SJR: 0.915, h-index: 53)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription   (Followers: 1)
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 3, SJR: 0.311, h-index: 16)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 2)
Acta Poética     Open Access   (Followers: 4)
Acta Psychologica     Hybrid Journal   (Followers: 23, SJR: 1.365, h-index: 73)
Acta Sociológica     Open Access  
Acta Tropica     Hybrid Journal   (Followers: 6, SJR: 1.059, h-index: 77)
Acta Urológica Portuguesa     Open Access  
Actas Dermo-Sifiliograficas     Full-text available via subscription   (Followers: 4)
Actas Dermo-Sifiliográficas (English Edition)     Full-text available via subscription   (Followers: 3)
Actas Urológicas Españolas     Full-text available via subscription   (Followers: 4, SJR: 0.383, h-index: 19)
Actas Urológicas Españolas (English Edition)     Full-text available via subscription   (Followers: 2)
Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 5, SJR: 0.141, h-index: 3)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 4, SJR: 0.112, h-index: 2)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 3)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.967, h-index: 57)
Addictive Behaviors     Hybrid Journal   (Followers: 15, SJR: 1.514, h-index: 92)
Addictive Behaviors Reports     Open Access   (Followers: 5)
Additive Manufacturing     Hybrid Journal   (Followers: 8, SJR: 1.039, h-index: 5)
Additives for Polymers     Full-text available via subscription   (Followers: 20)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 128, SJR: 5.2, h-index: 222)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 11, SJR: 1.265, h-index: 53)
Advanced Powder Technology     Hybrid Journal   (Followers: 16, SJR: 0.739, h-index: 33)
Advances in Accounting     Hybrid Journal   (Followers: 9, SJR: 0.299, h-index: 15)
Advances in Agronomy     Full-text available via subscription   (Followers: 15, SJR: 2.071, h-index: 82)
Advances in Anesthesia     Full-text available via subscription   (Followers: 25, SJR: 0.169, h-index: 4)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 3)
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 6, SJR: 1.054, h-index: 35)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 10, SJR: 0.801, h-index: 26)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 22, SJR: 1.286, h-index: 49)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 16, SJR: 3.31, h-index: 42)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4, SJR: 2.277, h-index: 43)
Advances in Botanical Research     Full-text available via subscription   (Followers: 3, SJR: 0.619, h-index: 48)
Advances in Cancer Research     Full-text available via subscription   (Followers: 25, SJR: 2.215, h-index: 78)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 9, SJR: 0.9, h-index: 30)
Advances in Catalysis     Full-text available via subscription   (Followers: 5, SJR: 2.139, h-index: 42)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 12)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 24, SJR: 0.183, h-index: 23)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 10, SJR: 0.665, h-index: 29)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 10, SJR: 1.268, h-index: 45)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 28, SJR: 0.938, h-index: 33)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 18, SJR: 2.314, h-index: 130)
Advances in Computers     Full-text available via subscription   (Followers: 16, SJR: 0.223, h-index: 22)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 11)
Advances in Digestive Medicine     Open Access   (Followers: 4)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 5)
Advances in Drug Research     Full-text available via subscription   (Followers: 22)
Advances in Ecological Research     Full-text available via subscription   (Followers: 41, SJR: 3.25, h-index: 43)
Advances in Engineering Software     Hybrid Journal   (Followers: 25, SJR: 0.486, h-index: 10)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 7)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 40, SJR: 5.465, h-index: 64)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 3)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 8)
Advances in Food and Nutrition Research     Full-text available via subscription   (Followers: 47, SJR: 0.674, h-index: 38)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 15)
Advances in Genetics     Full-text available via subscription   (Followers: 15, SJR: 2.558, h-index: 54)
Advances in Genome Biology     Full-text available via subscription   (Followers: 11)
Advances in Geophysics     Full-text available via subscription   (Followers: 6, SJR: 2.325, h-index: 20)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 21, SJR: 0.906, h-index: 24)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 0.497, h-index: 31)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 25)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 2, SJR: 0.396, h-index: 27)
Advances in Immunology     Full-text available via subscription   (Followers: 35, SJR: 4.152, h-index: 85)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 9, SJR: 1.132, h-index: 42)
Advances in Insect Physiology     Full-text available via subscription   (Followers: 3, SJR: 1.274, h-index: 27)
Advances in Integrative Medicine     Hybrid Journal   (Followers: 5)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 4)
Advances in Life Course Research     Hybrid Journal   (Followers: 8, SJR: 0.764, h-index: 15)
Advances in Lipobiology     Full-text available via subscription   (Followers: 2)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 9)
Advances in Marine Biology     Full-text available via subscription   (Followers: 16, SJR: 1.645, h-index: 45)
Advances in Mathematics     Full-text available via subscription   (Followers: 10, SJR: 3.261, h-index: 65)
Advances in Medical Sciences     Hybrid Journal   (Followers: 6, SJR: 0.489, h-index: 25)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 4, SJR: 1.44, h-index: 51)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 22)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 10)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 7, SJR: 0.324, h-index: 8)
Advances in Nanoporous Materials     Full-text available via subscription   (Followers: 4)
Advances in Oncobiology     Full-text available via subscription   (Followers: 3)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 15, SJR: 2.885, h-index: 45)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7, SJR: 0.148, h-index: 11)
Advances in Parasitology     Full-text available via subscription   (Followers: 7, SJR: 2.37, h-index: 73)
Advances in Pediatrics     Full-text available via subscription   (Followers: 24, SJR: 0.4, h-index: 28)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 13)
Advances in Pharmacology     Full-text available via subscription   (Followers: 15, SJR: 1.718, h-index: 58)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 7, SJR: 0.384, h-index: 26)
Advances in Phytomedicine     Full-text available via subscription  
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3, SJR: 0.248, h-index: 11)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (Followers: 8)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 5)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 19, SJR: 1.5, h-index: 62)
Advances in Psychology     Full-text available via subscription   (Followers: 60)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 5, SJR: 0.478, h-index: 32)
Advances in Radiation Oncology     Open Access  
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 2, SJR: 0.1, h-index: 2)
Advances in Space Research     Full-text available via subscription   (Followers: 343, SJR: 0.606, h-index: 65)
Advances in Structural Biology     Full-text available via subscription   (Followers: 8)
Advances in Surgery     Full-text available via subscription   (Followers: 7, SJR: 0.823, h-index: 27)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 30, SJR: 1.321, h-index: 56)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 15)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 13)
Advances in Virus Research     Full-text available via subscription   (Followers: 5, SJR: 1.878, h-index: 68)
Advances in Water Resources     Hybrid Journal   (Followers: 43, SJR: 2.408, h-index: 94)
Aeolian Research     Hybrid Journal   (Followers: 5, SJR: 0.973, h-index: 22)
Aerospace Science and Technology     Hybrid Journal   (Followers: 307, SJR: 0.816, h-index: 49)
AEU - Intl. J. of Electronics and Communications     Hybrid Journal   (Followers: 8, SJR: 0.318, h-index: 36)
African J. of Emergency Medicine     Open Access   (Followers: 5, SJR: 0.344, h-index: 6)
Ageing Research Reviews     Hybrid Journal   (Followers: 8, SJR: 3.289, h-index: 78)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 405, SJR: 1.385, h-index: 72)
Agri Gene     Hybrid Journal  
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 15, SJR: 2.18, h-index: 116)
Agricultural Systems     Hybrid Journal   (Followers: 30, SJR: 1.275, h-index: 74)
Agricultural Water Management     Hybrid Journal   (Followers: 38, SJR: 1.546, h-index: 79)
Agriculture and Agricultural Science Procedia     Open Access  
Agriculture and Natural Resources     Open Access   (Followers: 1)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 53, SJR: 1.879, h-index: 120)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.434, h-index: 14)
Air Medical J.     Hybrid Journal   (Followers: 5, SJR: 0.234, h-index: 18)
AKCE Intl. J. of Graphs and Combinatorics     Open Access   (SJR: 0.285, h-index: 3)
Alcohol     Hybrid Journal   (Followers: 9, SJR: 0.922, h-index: 66)
Alcoholism and Drug Addiction     Open Access   (Followers: 6)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 1, SJR: 0.436, h-index: 12)
Alexandria J. of Medicine     Open Access  
Algal Research     Partially Free   (Followers: 8, SJR: 2.05, h-index: 20)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 3)
Allergologia et Immunopathologia     Full-text available via subscription   (Followers: 1, SJR: 0.46, h-index: 29)
Allergology Intl.     Open Access   (Followers: 4, SJR: 0.776, h-index: 35)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 7, SJR: 0.158, h-index: 9)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 48, SJR: 4.289, h-index: 64)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 5)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 3)
American Heart J.     Hybrid Journal   (Followers: 48, SJR: 3.157, h-index: 153)
American J. of Cardiology     Hybrid Journal   (Followers: 45, SJR: 2.063, h-index: 186)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 38, SJR: 0.574, h-index: 65)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 6, SJR: 1.091, h-index: 45)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 16, SJR: 1.653, h-index: 93)
American J. of Human Genetics     Hybrid Journal   (Followers: 31, SJR: 8.769, h-index: 256)
American J. of Infection Control     Hybrid Journal   (Followers: 24, SJR: 1.259, h-index: 81)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 33, SJR: 2.313, h-index: 172)
American J. of Medicine     Hybrid Journal   (Followers: 46, SJR: 2.023, h-index: 189)
American J. of Medicine Supplements     Full-text available via subscription   (Followers: 3)
American J. of Obstetrics and Gynecology     Hybrid Journal   (Followers: 191, SJR: 2.255, h-index: 171)
American J. of Ophthalmology     Hybrid Journal   (Followers: 54, SJR: 2.803, h-index: 148)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 3)
American J. of Orthodontics and Dentofacial Orthopedics     Full-text available via subscription   (Followers: 6, SJR: 1.249, h-index: 88)
American J. of Otolaryngology     Hybrid Journal   (Followers: 23, SJR: 0.59, h-index: 45)
American J. of Pathology     Hybrid Journal   (Followers: 26, SJR: 2.653, h-index: 228)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 21, SJR: 2.764, h-index: 154)
American J. of Surgery     Hybrid Journal   (Followers: 34, SJR: 1.286, h-index: 125)
American J. of the Medical Sciences     Hybrid Journal   (Followers: 12, SJR: 0.653, h-index: 70)
Ampersand : An Intl. J. of General and Applied Linguistics     Open Access   (Followers: 5)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.066, h-index: 51)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 55, SJR: 0.124, h-index: 9)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 10)
Anales de Cirugia Vascular     Full-text available via subscription  
Anales de Pediatría     Full-text available via subscription   (Followers: 2, SJR: 0.209, h-index: 27)
Anales de Pediatría (English Edition)     Full-text available via subscription  
Anales de Pediatría Continuada     Full-text available via subscription   (SJR: 0.104, h-index: 3)
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 2, SJR: 2.577, h-index: 7)
Analytica Chimica Acta     Hybrid Journal   (Followers: 38, SJR: 1.548, h-index: 152)
Analytical Biochemistry     Hybrid Journal   (Followers: 162, SJR: 0.725, h-index: 154)
Analytical Chemistry Research     Open Access   (Followers: 8, SJR: 0.18, h-index: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 11)
Anesthésie & Réanimation     Full-text available via subscription   (Followers: 1)
Anesthesiology Clinics     Full-text available via subscription   (Followers: 22, SJR: 0.421, h-index: 40)
Angiología     Full-text available via subscription   (SJR: 0.124, h-index: 9)
Angiologia e Cirurgia Vascular     Open Access  
Animal Behaviour     Hybrid Journal   (Followers: 157, SJR: 1.907, h-index: 126)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 5, SJR: 1.151, h-index: 83)
Animal Reproduction Science     Hybrid Journal   (Followers: 5, SJR: 0.711, h-index: 78)
Annales d'Endocrinologie     Full-text available via subscription   (Followers: 1, SJR: 0.394, h-index: 30)
Annales d'Urologie     Full-text available via subscription  
Annales de Cardiologie et d'Angéiologie     Full-text available via subscription   (SJR: 0.177, h-index: 13)
Annales de Chirurgie de la Main et du Membre Supérieur     Full-text available via subscription  
Annales de Chirurgie Plastique Esthétique     Full-text available via subscription   (Followers: 2, SJR: 0.354, h-index: 22)
Annales de Chirurgie Vasculaire     Full-text available via subscription   (Followers: 1)

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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  [3043 journals]
  • Impact of the NAP-1 strain on disease severity, mortality, and recurrence
           of healthcare-associated Clostridium difficile infection
    • Authors: Karri A. Bauer; Jessica E.W. Johnston; Eric Wenzler; Debra A. Goff; Charles H. Cook; Joan-Miquel Balada-Llasat; Preeti Pancholi; Julie E. Mangino
      Pages: 1 - 6
      Abstract: Publication date: December 2017
      Source:Anaerobe, Volume 48
      Author(s): Karri A. Bauer, Jessica E.W. Johnston, Eric Wenzler, Debra A. Goff, Charles H. Cook, Joan-Miquel Balada-Llasat, Preeti Pancholi, Julie E. Mangino
      Objectives Studies are conflicting regarding the association of the North American pulsed-field gel electrophoresis type 1 (NAP1) strain in Clostridium difficile infection (CDI) and outcomes. We evaluated the association of NAP1 with healthcare-associated CDI disease severity, mortality, and recurrence at our academic medical center. Methods Healthcare-associated CDI cases were identified from November 1, 2011 through January 31, 2013. Multivariable regression models were used to evaluate the associations of NAP1 with severe disease (based on the Hines VA severity score index), mortality, and recurrence. Results Among 5424 stool specimens submitted to the Clinical Microbiology Laboratory, 292 (5.4%) were positive for C. difficile by polymerase chain reaction (PCR) on or after hospital day 4; 70 (24%) of these specimens also tested positive for NAP1. During the study period, 247 (85%) patients had non-severe disease and 45 (15%) patients had severe disease. Among patients with non-severe disease, 65 (26%) had NAP1 and among patients with severe disease, 5 (11%) had NAP1. After controlling for potential confounders, NAP1 was not associated with an increased likelihood of severe disease (adjusted odds ratio [aOR] = 0.35; 95% confidence interval [CI], 0.13–0.93), in-hospital mortality (aOR = 1.02; 95% CI, 0.53–1.96), or recurrence (aOR = 1.16, 95% CI, 0.36–3.77). Conclusions The NAP1 strain did not increase disease severity, mortality, or recurrence in this study, although the incidence of NAP1-positive healthcare associated-CDI was low. The role of strain typing in outcomes and treatment selection in patients with healthcare-associated CDI remains uncertain.

      PubDate: 2017-08-15T20:13:04Z
      DOI: 10.1016/j.anaerobe.2017.06.009
      Issue No: Vol. 48 (2017)
       
  • Development of a real-time PCR method for quantification of Prevotella
           histicola from the gut
    • Authors: Baskar Balakrishnan; David Luckey; Eric Marietta; Melissa Karau; Robin Patel; Joseph Murray; Veena Taneja
      Pages: 37 - 41
      Abstract: Publication date: December 2017
      Source:Anaerobe, Volume 48
      Author(s): Baskar Balakrishnan, David Luckey, Eric Marietta, Melissa Karau, Robin Patel, Joseph Murray, Veena Taneja
      We designed species-specific primers and developed a qPCR method for enumerating P. histicola from intestinal samples. The two designed primer sets showed specificity for the target 16S rRNA gene of P. histicola. The absolute qPCR method was sensitive to quantify as few as 103 colony-forming units (CFU) in the gut.

      PubDate: 2017-07-10T08:44:58Z
      DOI: 10.1016/j.anaerobe.2017.06.019
      Issue No: Vol. 48 (2017)
       
  • Clinical and molecular characteristics of community-acquired Clostridium
           difficile infections in comparison with those of hospital-acquired
           C. difficile
    • Authors: Soon Sung Kwon; Jung Lim Gim; Myung Sook Kim; Heejung Kim; Jun Yong Choi; Dongeun Yong; Kyungwon Lee
      Pages: 42 - 46
      Abstract: Publication date: December 2017
      Source:Anaerobe, Volume 48
      Author(s): Soon Sung Kwon, Jung Lim Gim, Myung Sook Kim, Heejung Kim, Jun Yong Choi, Dongeun Yong, Kyungwon Lee
      Community-acquired Clostridium difficile infection (CA-CDI) is a growing concern. CA-CDI differs from hospital-acquired C. difficile infection (HA-CDI) in its epidemiology, risk factors, severity, and outcomes. In this study, we investigated C. difficile infections in a tertiary care hospital in Seoul, Korea, and compared the CA-CDI and HA-CDI cases diagnosed in the same period. Total 593 cases were confirmed as CDI in 2014, of which CA-CDI accounted for 68 (11.5%) of the total CDI cases. Compared with HA-CDI, the mean age of CA-CDI cases was lower than that of HA-CDI (42.7 vs 60.4). In CA-CDI, antibiotic and proton pump inhibitor (PPI) use in the 12 preceding weeks and concurrent chemotherapy and tube feeding were less frequent compared with HA-CDI. In most cases (63/68, 92.6%), patients with CA-CDI recovered without any complications or recurrence. The most prevalent C. difficile type in CA-CDI cases was PCR-ribotype 012, accounting for 18.3% of the total, followed by PCR-ribotype 018 (16.7%).

      PubDate: 2017-08-15T20:13:04Z
      DOI: 10.1016/j.anaerobe.2017.06.014
      Issue No: Vol. 48 (2017)
       
  • Prevalence and characteristics of Clostridium perfringens and Clostridium
           difficile in dogs and cats attended in diverse veterinary clinics from the
           Madrid region
    • Authors: Sergio Álvarez-Pérez; José L. Blanco; Celine Harmanus; Ed J. Kuijper; Marta E. García
      Pages: 47 - 55
      Abstract: Publication date: Available online 5 July 2017
      Source:Anaerobe
      Author(s): Sergio Álvarez-Pérez, José L. Blanco, Celine Harmanus, Ed J. Kuijper, Marta E. García
      Despite extensive research on the epidemiology of pathogenic clostridia in dogs and cats, most published studies focus on a selected animal population and/or a single veterinary medical centre. We assessed the burden of Clostridium perfringens and C. difficile shedding by small animals in 17 veterinary clinics located within the Madrid region (Spain) and differing in size, number and features of animals attended and other relevant characteristics. In addition, we studied the genetic diversity and antibiotic susceptibility of recovered isolates. Selective culture of all fecal specimens collected during a single week from dogs (n = 105) and cats (n = 37) attended in participating clinics yielded C. perfringens/C. difficile from 31%, 4.8% of the dogs, and 20%, 0% of the cats analyzed, respectively, and three dogs yielded both species. Furthermore, 17 animals (15 dogs and two cats) that yielded a positive culture for either species were recruited for a follow-up survey and C. perfringens was again obtained from nine dogs. Considerable differences in prevalence were observed among participating clinics for both clostridial species. C. perfringens isolates (n = 109) belonged to toxinotypes A (97.2%) and E (three isolates from one dog), whereas C. difficile isolates (n = 18) belonged to the toxigenic ribotypes 106 (33.3%) and 154 (16.7%), a 009-like ribotype (33.3%) and an unknown non-toxigenic ribotype (16.7%). Amplified fragment length polymorphism-based fingerprinting classified C. perfringens and C. difficile isolates into 105 and 15 genotypes, respectively, and tested isolates displayed in vitro resistance to benzylpenicillin (2.8%, 88.8%), clindamycin (0%, 16.7%), erythromycin (0.9%, 16.7%), imipenem (1.8%, 100%), levofloxacin (0.9%, 100%), linezolid (5.5%, 0%), metronidazole (4.6%, 0%) and/or tetracycline (7.3%, 0%). All animals from which multiple isolates were retrieved yielded ≥2 different genotypes and/or antimicrobial susceptibility profiles. Future studies should focus on the seasonal and geographical variations of prevalence and diversity patterns of clostridial species in small animals.

      PubDate: 2017-07-10T08:44:58Z
      DOI: 10.1016/j.anaerobe.2017.06.023
      Issue No: Vol. 48 (2017)
       
  • Clostridium perfringens and C. difficile in parvovirus-positive dogs
    • Authors: Rodrigo Otávio Silveira Silva; Fernanda Alves Dorella; Henrique Cesar Pereira Figueiredo; Érica Azevedo Costa; Vanessa Pelicia; Bruna Letícia Devidé Ribeiro; Marcio Garcia Ribeiro; Antonio Carlos Paes; Jane Megid; Francisco Carlos Faria Lobato
      Pages: 66 - 69
      Abstract: Publication date: December 2017
      Source:Anaerobe, Volume 48
      Author(s): Rodrigo Otávio Silveira Silva, Fernanda Alves Dorella, Henrique Cesar Pereira Figueiredo, Érica Azevedo Costa, Vanessa Pelicia, Bruna Letícia Devidé Ribeiro, Marcio Garcia Ribeiro, Antonio Carlos Paes, Jane Megid, Francisco Carlos Faria Lobato
      The aim of this study was to investigate Clostridium difficile and Clostridium perfringens in 82 diarrheic dogs positive for canine parvovirus type 2 (CPV). Enterotoxigenic C. perfringens type A was isolated from three (3.6%) dogs. One (1.2%) strain was also positive for NetE- and NetF-encoding genes, which are commonly associated with diarrhea in dogs. Toxigenic C. difficile was isolated from one animal (1.2%), which was also positive for A/B toxins. The present study identified C. difficile and C. perfringens infection in CPV-positive dogs. Further studies are necessary to clarify if clostridial infections may predispose or potentiate CPV-infection in dogs or vice versa.

      PubDate: 2017-07-27T10:19:59Z
      DOI: 10.1016/j.anaerobe.2017.07.001
      Issue No: Vol. 48 (2017)
       
  • Description of Absiella argi gen. nov., sp. nov., and transfer of
           Eubacterium dolichum and Eubacterium tortuosum to the genus Absiella as
           Absiella dolichum comb. nov. and Absiella tortuosum comb. nov
    • Authors: Jayoung Paek; Yeseul Shin; Joong-Su Kim; Hongik Kim; Joong-Ki Kook; Woon Kee Paek; Young-Hyo Chang
      Pages: 70 - 75
      Abstract: Publication date: December 2017
      Source:Anaerobe, Volume 48
      Author(s): Jayoung Paek, Yeseul Shin, Joong-Su Kim, Hongik Kim, Joong-Ki Kook, Woon Kee Paek, Young-Hyo Chang
      Gram-positive, straight or slightly curved rod-shaped bacteria, designated as strains N6H1-5T and N6H1-3, were isolated from fecal samples of old dog. The analysis of 16S rRNA gene sequences indicated that the isolates belonged to the Clostridium cluster XVI and were closely related to Eubacterium dolichum KCTC 5832T, Eubacterium tortuosum DSM 3987T, Clostridium innocuum KCTC 5183T, Allobaculum stecoricanis DSM 13633T, Eubacterium limosum KCTC 3266T, and Clostridium butyricum KCTC 1871T, with 94.0%, 93.8%, 92.0%, 84.9%, 80.7%, and 80.0% sequence similarity, respectively. Chemotaxonomic data supported placement of the strains N6H1-5T and N6H1-3 in the new taxon. The strains contained m-diaminopimelic acid cell wall peptidoglycan; the major polar lipids were diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), and glycolipids (GL); and the major fatty acids were C18:1 cis 9 (30.7%) and C16:0 (17.1%). The predominant metabolic end product was lactic acid. The G + C content was 35.8 mol%. The most closely related species, E. dolichum and E. tortuosum, were also assigned to the new taxon, based on the phylogenetic analysis and phenotypic data. Thus, the type strain N6H1-5T (=KCTC 15422 = JCM 30884) represents a novel genus and species, for which the name Absiella argi gen. nov., sp. nov is proposed. It is also proposed that E. dolichum KCTC 5832T and E. tortuosum DSM 3987T be transferred to this new genus, and named Absiella dolichum comb. nov. and Absiella tortuosum comb. nov., respectively.

      PubDate: 2017-08-04T19:42:55Z
      DOI: 10.1016/j.anaerobe.2017.07.006
      Issue No: Vol. 48 (2017)
       
  • Comparative phenotypic analysis of “Clostridium neonatale” and
           Clostridium butyricum isolates from neonates
    • Authors: S. Schönherr-Hellec; G. Klein; J. Delannoy; L. Ferraris; I. Friedel; J.C. Rozé; M.J. Butel; J. Aires
      Pages: 76 - 82
      Abstract: Publication date: December 2017
      Source:Anaerobe, Volume 48
      Author(s): S. Schönherr-Hellec, G. Klein, J. Delannoy, L. Ferraris, I. Friedel, J.C. Rozé, M.J. Butel, J. Aires
      “Clostridium neonatale” was recently described as a new species within the Cluster I of the Clostridium genus sensu stricto. In this study, we characterized “C. neonatale” isolates (n = 42) and compared their phenotypic properties with those of Clostridium butyricum (n = 26), a close related species. Strains isolated from fecal samples of healthy neonates were tested for different phenotypic characteristics. Compared to C. butyricum, “C. neonatale” showed a significant higher surface hydrophobicity (p = 0.0047), exopolysaccharide production (p = 0.0069), aero-tolerance (p = 0.0222) and viability at 30 °C (p = 0.0006). A lower swimming ability (p = 0.0146) and tolerance against bile (0.3%) (p = 0.0494), acid (pH 4.5) (p < 0.0001), osmolarity (NaCl 5%, p = 0.0188) and temperature at 50 °C (p = 0.0013) characterized “C. neonatale” strains. Our results showed that “C. neonatale” behaves very differently from C. butyricum and suggests specific responses to environmental changes. Besides it is the first study on clinical isolates for these two anaerobic members of the newborns' gut microbiota and broadens our knowledge about their phenotypic traits.

      PubDate: 2017-08-04T19:42:55Z
      DOI: 10.1016/j.anaerobe.2017.07.002
      Issue No: Vol. 48 (2017)
       
  • Effects of Clostridium perfringens iota toxin in the small intestine of
           mice
    • Authors: Leandro M. Redondo; Enzo A. Redondo; Gabriela C. Dailoff; Carlos L. Leiva; Juan M. Díaz-Carrasco; Octavio A. Bruzzone; Adriana Cangelosi; Patricia Geoghegan; Mariano E. Fernandez-Miyakawa
      Pages: 83 - 88
      Abstract: Publication date: December 2017
      Source:Anaerobe, Volume 48
      Author(s): Leandro M. Redondo, Enzo A. Redondo, Gabriela C. Dailoff, Carlos L. Leiva, Juan M. Díaz-Carrasco, Octavio A. Bruzzone, Adriana Cangelosi, Patricia Geoghegan, Mariano E. Fernandez-Miyakawa
      Iota toxin is a binary toxin solely produced by Clostridium perfringens type E strains, and is structurally related to CDT from C. difficile and CST from C. spiroforme. As type E causes hemorrhagic enteritis in cattle, it is usually assumed that associated diseases are mediated by iota toxin, although evidence in this regard has not been provided. In the present report, iota toxin intestinal effects were evaluated in vivo using a mouse model. Histological damage was observed in ileal loops treated with purified iota toxin after 4 h of incubation. Luminal iota toxin induced fluid accumulation in the small intestine in a dose dependent manner, as determined by the enteropooling and the intestinal loop assays. None of these changes were observed in the large intestine. These results suggest that C. perfringens iota toxin alters intestinal permeability, predominantly by inducing necrosis and degenerative changes in the mucosal epithelium of the small intestine, as well as changes in intestinal motility. The obtained results suggest a central role for iota toxin in the pathogenesis of C. perfringens type E hemorrhagic enteritis, and contribute to remark the importance of clostridial binary toxins in digestive diseases.

      PubDate: 2017-08-04T19:42:55Z
      DOI: 10.1016/j.anaerobe.2017.07.007
      Issue No: Vol. 48 (2017)
       
  • A multi-center ring trial for the identification of anaerobic bacteria
           using MALDI-TOF MS
    • Authors: A.C.M. Veloo; H. Jean-Pierre; U.S. Justesen; T. Morris; E. Urban; I. Wybo; H.N. Shah; A.W. Friedrich; T. Morris; H.N. Shah; H. Jean-Pierre; U.S. Justesen; E. Nagy; E. Urban; M. Kostrzewa; A. Veloo; A.W. Friedrich
      Pages: 94 - 97
      Abstract: Publication date: December 2017
      Source:Anaerobe, Volume 48
      Author(s): A.C.M. Veloo, H. Jean-Pierre, U.S. Justesen, T. Morris, E. Urban, I. Wybo, H.N. Shah, A.W. Friedrich, T. Morris, H.N. Shah, H. Jean-Pierre, U.S. Justesen, E. Nagy, E. Urban, M. Kostrzewa, A. Veloo, A.W. Friedrich
      Inter-laboratory reproducibility of Matrix Assisted Laser Desorption Time-of-Flight Mass Spectrometry (MALDI-TOF MS) of anaerobic bacteria has not been shown before. Therefore, ten anonymized anaerobic strains were sent to seven participating laboratories, an initiative of the European Network for the Rapid Identification of Anaerobes (ENRIA). On arrival the strains were cultured and identified using MALDI-TOF MS. The spectra derived were compared with two different Biotyper MALDI-TOF MS databases, the db5627 and the db6903. The results obtained using the db5627 shows a reasonable variation between the different laboratories. However, when a more optimized database is used, the variation is less pronounced. In this study we show that an optimized database not only results in a higher number of strains which can be identified using MALDI-TOF MS, but also corrects for differences in performance between laboratories.

      PubDate: 2017-08-15T20:13:04Z
      DOI: 10.1016/j.anaerobe.2017.07.004
      Issue No: Vol. 48 (2017)
       
  • Detection of enterotoxin and protease genes among Hungarian clinical
           Bacteroides fragilis isolates
    • Authors: Károly Péter Sárvári; József Sóki; Miklós Iván; Cecília Miszti; Krisztina Latkóczy; Szilvia Zsóka Melegh; Edit Urbán
      Pages: 98 - 102
      Abstract: Publication date: December 2017
      Source:Anaerobe, Volume 48
      Author(s): Károly Péter Sárvári, József Sóki, Miklós Iván, Cecília Miszti, Krisztina Latkóczy, Szilvia Zsóka Melegh, Edit Urbán
      Bacteroides fragilis as a commensal bacterium is a member of the human intestinal flora, but as an opportunistic pathogen it can cause serious infections as well. Some of them, harbouring an enterotoxin gene (bft), may cause diarrhoea mainly in young children. Recently it has been shown that a member of C11 proteases called fragipain (fpn) can activate the enterotoxin, while C10 protease (bfp) is suspected of playing an important role in the invasiveness of the B. fragilis isolates. The objective of this study was to investigate the prevalence and distribution of the bft isotypes in 200 Hungarian B. fragilis isolates collected recently; and in a subset of 72 strains, we wanted to determine the prevalence of bfp1-4 and fpn genes in bft-positive and bft-negative strains. Using the MALDI-TOF MS cfiA identification project file, 19 B. fragilis strains belonging to Division II were identified and the presence of the cfiA gene was confirmed by RT-PCR. Twenty six (13.0%) B. fragilis isolates turned out to be bft gene positive by RT-PCR; 20 isolates harboured bft-1 and six bft-2 isotypes, but no bft-3 isotype containing strains were found. A melting curve analysis and the PCR-RFLP were performed to differentiate between the bft-1 and bft-2 isotypes confirmed by sequencing. Thirty eight strains harboured bfp1, 58 isolates contained bfp2 gene, while 17 isolates proved positive for bfp3. Morever, no bfp4 positive isolate was found, and some of the B. fragilis strains tested harboured two or three bfp isotypes simultaneously. Among the 26 bft-positive strains, 24 contained the fpn gene, which confirms the role of fragipain in the activation of B. fragilis enterotoxin. In experiments, a significant negative correlation between fpn and cfiA was demonstrated (p < 0.000), a positive correlation was found between bfp2 and fpn genes (p = 0.0000803), and a negative correlation between bfp2 and cfiA genes (p = 0.011).

      PubDate: 2017-08-15T20:13:04Z
      DOI: 10.1016/j.anaerobe.2017.07.005
      Issue No: Vol. 48 (2017)
       
  • Pro-inflammatory cytokine responses in human gingival epithelial cells
           after stimulation with cell wall extract of Aggregatibacter
           actinomycetemcomitans subtypes
    • Authors: Nuntiya Pahumunto; Pareena Chotjumlong; Anupong Makeudom; Suttichai Krisanaprakornkit; Gunnar Dahlen; Rawee Teanpaisan
      Pages: 103 - 109
      Abstract: Publication date: December 2017
      Source:Anaerobe, Volume 48
      Author(s): Nuntiya Pahumunto, Pareena Chotjumlong, Anupong Makeudom, Suttichai Krisanaprakornkit, Gunnar Dahlen, Rawee Teanpaisan
      Varying cytokine responses of human gingival epithelial cells (HGECs) by Aggregatibacter actinomycetemcomitans subtypes have been found. Most studies have used reference strains, whereas a few has evaluated the cytokine expression in response to clinical subtypes of this bacterial species. This study aimed to examine whether there was any difference in cytokine responses of HGECs stimulated with cell wall extract (CWE) from A. actinomycetemcomitans subtypes included clinical strains from Thai adult periodontitis, various serotypes and non-serotypeable strains, strains from deep or shallow pockets, and reference serotype strains. Totally 50 clinical strains and 7 reference strains of A. actinomycetemcomitans were analyzed for the expression of IL-1β, IL-6, IL-8, and TNF-α mRNAs in HGECs by real time-PCR, and the IL-8 concentrations in cell-free supernatant measured using ELISA. An in vitro effect of released IL-8 on neutrophil migration was examined using transwell chambers. Result showed that among four cytokines studied, IL-8 mRNA was highly up-regulated by both clinical and reference strains. Serotype f revealed the highest expression compared to other serotypes. The JP2-like leukotoxin promoter gene and non-serotypeable (NS1 and NS2) demonstrated lower IL-8 responses compared to serotypeable strains, and IL-8 responses upon stimulation with clinical strains from deep pockets were also significantly lower than those isolated from shallow pockets (P < 0.01). Our findings suggest that the clinical isolates of A. actinomycetemcomitans associating with deep pockets, JP2-like leukotoxin promoter gene, NS1, and NS2 may interfere neutrophil function via minimal and immunosuppressing IL-8 responses, which may enhance their survival and virulence.

      PubDate: 2017-08-15T20:13:04Z
      DOI: 10.1016/j.anaerobe.2017.08.001
      Issue No: Vol. 48 (2017)
       
  • Stability and efficacy of frozen and lyophilized fecal microbiota
           transplant (FMT) product in a mouse model of Clostridium difficile
           infection (CDI)
    • Authors: Zhi-Dong Jiang; Ashley Alexander; Shi Ke; Evangelia M. Valilis; Shaofan Hu; Bingjie Li; Herbert L. DuPont
      Pages: 110 - 114
      Abstract: Publication date: December 2017
      Source:Anaerobe, Volume 48
      Author(s): Zhi-Dong Jiang, Ashley Alexander, Shi Ke, Evangelia M. Valilis, Shaofan Hu, Bingjie Li, Herbert L. DuPont
      Freezing donor fecal microbiota has simplified fecal microbiota transplantation (FMT) in the treatment of recurrent C. difficile infection (CDI). However, the optimal storage time for the frozen FMT products remains unknown. Using an established murine model of CDI, stability and efficacy of frozen and lyophilized FMT product was studied at time points from 2 months to 15 months. DNA was extracted from fecal samples from the mice with identification of specific bacterial species by real-time quantitative PCR (qPCR). FMT product stability and efficacy were measured by occurrence of diarrhea in the challenged mice together with stability of the microbiota composition. The results were analyzed and compared by SAS statistical software. All mice treated with only C. difficile developed diarrhea within 72 h. Mice treated with frozen (n = 5/group), lyophilized (n = 5/group) products stored for ≤ 7-month or fresh FMT product (n = 22) were protected from post C. difficile challenge diarrhea. There was no difference between frozen and lyophilized products (n = 5/group) stored for ≤ 7 months 95% CI 1.00 (0.38–2.64) and 1.00 (0.38–2.64), respectively. Prevention if CDI by frozen and lyophilized product was not different for storage of 9-, 11- and 15-months. qPCR results demonstrated there were no significant quantitative change in Bacteroides and Clostridium species during any of the storage times (P > 0.05). In the present study, frozen and lyophilized FMT products were stored up to 7 months without losing microbiota composition and therapeutic efficacy. The animal model described may be useful to study stability of human microbiota designed for FMT.

      PubDate: 2017-08-15T20:13:04Z
      DOI: 10.1016/j.anaerobe.2017.08.003
      Issue No: Vol. 48 (2017)
       
  • Endocarditis caused by anaerobic bacteria
    • Authors: M. Kestler; P. Muñoz; M. Marín; M.A. Goenaga; P. Idígoras Viedma; A. de Alarcón; J.A. Lepe; D. Sousa Regueiro; J.M. Bravo-Ferrer; M. Pajarón; C. Costas; M.V. García-López; C. Hidalgo-Tenorio; M. Moreno; E. Bouza
      Pages: 33 - 38
      Abstract: Publication date: October 2017
      Source:Anaerobe, Volume 47
      Author(s): M. Kestler, P. Muñoz, M. Marín, M.A. Goenaga, P. Idígoras Viedma, A. de Alarcón, J.A. Lepe, D. Sousa Regueiro, J.M. Bravo-Ferrer, M. Pajarón, C. Costas, M.V. García-López, C. Hidalgo-Tenorio, M. Moreno, E. Bouza
      Background Infective endocarditis (IE) caused by anaerobic bacteria is a rare and poorly characterized disease. Most data reported in the literature are from case reports [1–3]. Therefore, we assessed the situation of anaerobic IE (AIE) in Spain using the database of the Spanish Collaboration on Endocarditis (GAMES). Methods We performed a prospective study from 2008 to 2016 in 26 Spanish centers. We included 2491 consecutive cases of definite IE (Duke criteria). Results Anaerobic bacteria caused 22 cases (0.9%) of definite IE. Median age was 66 years (IQR, 56–73), and 19 (86.4%) patients were men. Most patients (14 [63.6%]) had prosthetic valve IE and all episodes were left-sided: aortic valves, 12 (54.5%); and mitral valves, 8 (36.4%). The most common pathogens were Propionibacterium acnes (14 [63.6%]), Lactobacillus spp (3 [13.63%]), and Clostridium spp. (2 [9.0%]), and the infection was mainly odontogenic. Fifteen of the 22 patients (68.2%) underwent cardiac surgery. Mortality was 18.2% during admission and 5.5% after 1 year of follow-up. When patients with AIE were compared with the rest of the cohort, we found that although those with AIE had a similar age and Charlson comorbidity index, they were more likely to have community-acquired IE (86.4% vs. 60.9%, p = 0.01), have undergone cardiac surgery (68.2% vs 48.7% p = 0.06), and have had lower mortality rates during admission (18.2% vs. 27.3%). Conclusion IE due to anaerobic bacteria is an uncommon disease that affects mainly prosthetic valves and frequently requires surgery. Otherwise, there are no major differences between AIE and IE caused by other microorganisms.

      PubDate: 2017-08-15T20:13:04Z
      DOI: 10.1016/j.anaerobe.2017.04.002
      Issue No: Vol. 47 (2017)
       
  • A comparative study of Cutibacterium (Propionibacterium) acnes clones from
           acne patients and healthy controls
    • Authors: H.B. Lomholt; C.F.P. Scholz; H. Brüggemann; H. Tettelin; M. Kilian
      Pages: 57 - 63
      Abstract: Publication date: October 2017
      Source:Anaerobe, Volume 47
      Author(s): H.B. Lomholt, C.F.P. Scholz, H. Brüggemann, H. Tettelin, M. Kilian
      Background Cutibacterium (Propionibacterium) acnes is assumed to play an important role in the pathogenesis of acne. Objectives To examine if clones with distinct virulence properties are associated with acne. Methods Multiple C. acnes isolates from follicles and surface skin of patients with moderate to severe acne and healthy controls were characterized by multilocus sequence typing. To determine if CC18 isolates from acne patients differ from those of controls in the possession of virulence genes or lack of genes conducive to a harmonious coexistence the full genomes of dominating CC18 follicular clones from six patients and five controls were sequenced. Results Individuals carried one to ten clones simultaneously. The dominating C. acnes clones in follicles from acne patients were exclusively from the phylogenetic clade I-1a and all belonged to clonal complex CC18 with the exception of one patient dominated by the worldwide-disseminated and often antibiotic resistant clone ST3. The clonal composition of healthy follicles showed a more heterogeneous pattern with follicles dominated by clones representing the phylogenetic clades I-1a, I-1b, I-2 and II. Comparison of follicular CC18 gene contents, allelic versions of putative virulence genes and their promoter regions, and 54 variable-length intragenic and inter-genic homopolymeric tracts showed extensive conservation and no difference associated with the clinical origin of isolates. Conclusions The study supports that C. acnes strains from clonal complex CC18 and the often antibiotic resistant clone ST3 are associated with acne and suggests that susceptibility of the host rather than differences within these clones may determine the clinical outcome of colonization.

      PubDate: 2017-04-25T12:31:39Z
      DOI: 10.1016/j.anaerobe.2017.04.006
      Issue No: Vol. 47 (2017)
       
  • Evaluation of the routine antimicrobial susceptibility testing results of
           clinically significant anaerobic bacteria in a Slovenian tertiary-care
           hospital in 2015
    • Authors: Samo Jeverica; Urša Kolenc; Manica Mueller-Premru; Lea Papst
      Pages: 64 - 69
      Abstract: Publication date: October 2017
      Source:Anaerobe, Volume 47
      Author(s): Samo Jeverica, Urša Kolenc, Manica Mueller-Premru, Lea Papst
      The aim of our study was to determined antimicrobial susceptibility profiles of 2673 clinically significant anaerobic bacteria belonging to the major genera, isolated in 2015 in a large tertiary-care hospital in Slovenia. The species identification was performed by MALDI-TOF mass spectrometry. Antimicrobial susceptibility was determined immediately at the isolation of the strains against: penicillin, co-amoxiclav, imipenem, clindamycin and metronidazole, using gradient diffusion methodology and EUCAST breakpoints. The most frequent anaerobes were Bacteroides fragilis group with 31% (n = 817), Gram positive anaerobic cocci (GPACs) with 22% (n = 589), Prevotella with 14% (n = 313) and Propionibacterium with 8% (n = 225). Metronidazole has retained full activity (100%) against all groups of anaerobic bacteria intrinsically susceptible to it. Co-amoxiclav and imipenem were active against most tested anaerobes with zero or low resistance rates. However, observed resistance to co-amoxiclav (8%) and imipenem (1%) is worrying especially among B. fragilis group isolates. High overall resistance (23%) to clindamycin was detected in our study and was highest among the genera Prevotella, Bacteroides, Parabacteroides, GPACs and Clostridium. Routine testing of antimicrobial susceptibility of clinically relevant anaerobic bacteria is feasible and provides good surveillance data.

      PubDate: 2017-08-15T20:13:04Z
      DOI: 10.1016/j.anaerobe.2017.04.007
      Issue No: Vol. 47 (2017)
       
  • Eggerthella lenta bacteremia in solid tumor cancer patients: Pathogen or
           witness of frailty'
    • Authors: Paul-Louis Woerther; Sami Antoun; Elisabeth Chachaty; Mansouria Merad
      Pages: 70 - 72
      Abstract: Publication date: October 2017
      Source:Anaerobe, Volume 47
      Author(s): Paul-Louis Woerther, Sami Antoun, Elisabeth Chachaty, Mansouria Merad
      Eggerthella lenta is increasingly found in patients with severe comorbidities. Because oncologic patients are exposed to emerging pathogens, we aimed to describe the factors associated with E. lenta bacteremia in this immunosuppressed population. Oncology patients with blood cultures positive for E. lenta were retrospectively recorded from 2009 to 2015. Socio-demographic and medical/biological data as well as potential risk factors and mortality were recorded and analyzed. Twenty-three patients were included. Gastro intestinal (GI) and gynecological cancers were reported in 12/23 (52%) and 7/23 cases (30%), respectively. Eleven/23 patients (48%) had metastatics lesions and 6/23 (26%) had peritoneal carcinomatosis. No associated tissue infection was found in 14/23 cases (61%). Blood cultures yielded at least one other species in addition to E. lenta in 10/23 cases (43%). Mortality associated with E. lenta bacteremia was 22% (5/23). E. lenta bacteremia often occurred in patients with advanced cancer disease without documented infection. In most of the cases, intestinal obstruction and/or isolated fever were the only recorded symptoms. In these cases, the damages of intestinal barrier induced by the cancer and/or its specific treatments may be the cause of bacterial translocation.

      PubDate: 2017-08-15T20:13:04Z
      DOI: 10.1016/j.anaerobe.2017.04.010
      Issue No: Vol. 47 (2017)
       
  • Evaluation of the genus of Caldicellulosiruptor for production of
           1,2-propanediol from methylpentoses
    • Authors: Eva Maria Ingvadottir; Sean Michael Scully; Johann Orlygsson
      Pages: 86 - 88
      Abstract: Publication date: October 2017
      Source:Anaerobe, Volume 47
      Author(s): Eva Maria Ingvadottir, Sean Michael Scully, Johann Orlygsson
      Caldicellulosiruptor species degrade l-rhamnose and l-fucose to 1,2-propanediol. Six of the nine species within the genus produced 1,2-propanediol from l-rhamnose and three utilized l-fucose to produce the compound. Yields of 1,2-propanediol up to 40.5% of the theoretical yield were observed from methylpentoses catabolism.

      PubDate: 2017-05-02T12:45:07Z
      DOI: 10.1016/j.anaerobe.2017.04.015
      Issue No: Vol. 47 (2017)
       
  • Susceptibility of bacterial vaginosis (BV)-associated bacteria to
           secnidazole compared to metronidazole, tinidazole and clindamycin
    • Authors: Melinda A.B. Petrina; Lisa A. Cosentino; Lorna K. Rabe; Sharon L. Hillier
      Pages: 115 - 119
      Abstract: Publication date: October 2017
      Source:Anaerobe, Volume 47
      Author(s): Melinda A.B. Petrina, Lisa A. Cosentino, Lorna K. Rabe, Sharon L. Hillier
      Secnidazole, a 5-nitroimidazole with a longer half-life, is structurally related to metronidazole and tinidazole. For treatment of bacterial vaginosis (BV), secnidazole is a suitable single-dose oral drug having a longer serum half-life than metronidazole. The objective of this study was to evaluate the antimicrobial susceptibility of vaginal isolates of facultative and anaerobic bacteria to secnidazole, metronidazole, tinidazole and clindamycin. A total of 605 unique BV-related bacteria and 108 isolates of lactobacilli recovered from the human vagina of US women during the years 2009–2015 were tested for antimicrobial susceptibility by the agar dilution CLSI reference method to determine the minimal inhibitory concentration (MIC). The MIC90 (μg/mL) for secnidazole was similar to metronidazole and tinidazole for Anaerococcus tetradius (secnidazole: MIC90 2; metronidazole: MIC90 2; tinidazole: MIC90 4), Atopobium vaginae (32; >128; 128), Bacteroides species (2; 2; 2), Finegoldia magna (2; 2; 4), Gardnerella vaginalis (128; 64; 32), Mageeibacillus indolicus (2; 2; 2), Megasphaera-like bacteria (0.5; 0.25; 0.5), Mobiluncus curtisii (128; >128; >128) and Mobiluncus mulieris (>128; >128; >128), Peptoniphilus lacrimalis (4; 4; 4) and Peptoniphilus harei (2; 2; 4), Porphyromonas species (0.25; 0.5; 0.25), Prevotella bivia (8; 8; 8), Prevotella amnii (2; 1; 2) and Prevotella timonensis (2; 2; 2). In this evaluation, 14 (40%) of 35 P. bivia, 5 (14%) of 35 P. amnii and 21 (58%) of 36 P. timonensis isolates were resistant to clindamycin with MIC values of >128 μg/mL. Secnidazole, like metronidazole, was superior to clindamycin for Prevotella spp., Bacteroides spp., Peptoniphilus spp., Anaerococcus tetradius and Finegoldia magna. Clindamycin had greater activity against Atopobium vaginae, Gardnerella vaginalis and Mobiluncus spp. compared to the nitroimidazoles. All 27 Lactobacillus crispatus, 26 (96%) of 27 L. jensenii, 5 (19%) of 27 L. gasseri and 18 (67%) of 27 L. iners isolates were susceptible to clindamycin (MIC ≤2) while the MIC90 for all lactobacilli tested was >128 μg/mL for secnidazole, metronidazole and tinidazole. Secnidazole has similar in vitro activity against the range of microorganisms associated with BV compared to metronidazole or tinidazole. Further, secnidazole spares lactobacilli, a characteristic which is desirable in drugs used to treat bacterial vaginosis.

      PubDate: 2017-08-15T20:13:04Z
      DOI: 10.1016/j.anaerobe.2017.05.005
      Issue No: Vol. 47 (2017)
       
  • First described case of prosthetic joint infection with Clostridium
           disporicum
    • Authors: Joseph A. McBride; Alana K. Sterkel; William M. Rehrauer; Jeannina A. Smith
      Abstract: Publication date: Available online 1 July 2017
      Source:Anaerobe
      Author(s): Joseph A. McBride, Alana K. Sterkel, William M. Rehrauer, Jeannina A. Smith
      An orthopedic hardware infection with Clostridium disporicum is described. C. disporicum is a gram positive anaerobic bacillus which can contain two subterminal spores. C. disporicum had not previously been reported in musculoskeletal infections. Gram stains demonstrating gram positive bacilli with two subterminal spores should alert practitioners to the possibility of C. disporicum infection.
      Graphical abstract image

      PubDate: 2017-07-01T15:30:53Z
      DOI: 10.1016/j.anaerobe.2017.06.022
       
  • Is Clostridium difficile infection a risk factor for subsequent
           bloodstream infection'
    • Authors: Robert J. Ulrich; Kavitha Santhosh; Jill A. Mogle; Vincent B. Young; Krishna Rao
      Abstract: Publication date: Available online 29 June 2017
      Source:Anaerobe
      Author(s): Robert J. Ulrich, Kavitha Santhosh, Jill A. Mogle, Vincent B. Young, Krishna Rao
      Background Clostridium difficile infection (CDI) is a common nosocomial diarrheal illness increasingly associated with mortality in United States. The underlying factors and mechanisms behind the recent increases in morbidity from CDI have not been fully elucidated. Murine models suggest a mucosal barrier breakdown leads to bacterial translocation and subsequent bloodstream infection (BSI). This study tests the hypothesis that CDI is associated with subsequent BSI in humans. Methods We conducted a retrospective cohort study on 1132 inpatients hospitalized >72 h with available stool test results for toxigenic C. difficile. The primary outcome was BSI following CDI. Secondary outcomes included 30-day mortality, colectomy, readmission, and ICU admission. Unadjusted and adjusted logistic regression models were developed. Results CDI occurred in 570 of 1132 patients (50.4%). BSI occurred in 86 (7.6%) patients. Enterococcus (14%) and Klebsiella (14%) species were the most common organisms. Patients with BSI had higher comorbidity scores and were more likely to be male, on immunosuppression, critically ill, and have a central venous catheter in place. Of the patients with BSI, 36 (42%) had CDI. CDI was not associated with subsequent BSI (OR 0.69; 95% CI 0.44–1.08; P = 0.103) in unadjusted analysis. In multivariable modeling, CDI appeared protective against subsequent BSI (OR 0.57; 95% CI 0.34–0.96; P = 0.036). Interaction modeling suggests a complicated relationship among CDI, BSI, antibiotic exposure, and central venous catheter use. Conclusions In this cohort of inpatients that underwent testing for CDI, CDI was not a risk factor for developing subsequent BSI.
      Teaser Key Points: Clostridium difficile infection is not associated with subsequent bloodstream infection. It is associated with male gender, immunosuppression, comorbid disease burden, and systemic inflammatory response syndrome.

      PubDate: 2017-07-01T15:30:53Z
      DOI: 10.1016/j.anaerobe.2017.06.020
       
  • A case of severe empyema with acute respiratory distress syndrome caused
           by Slackia exigua requiring veno-venous extracorporeal membrane
           oxygenation
    • Authors: M.Y. Man; H.P. Shum; Alan Wu; R.A. Lee; W.W. Yan
      Abstract: Publication date: Available online 28 June 2017
      Source:Anaerobe
      Author(s): M.Y. Man, H.P. Shum, Alan Wu, R.A. Lee, W.W. Yan
      Slackia exigua (S. exigua) is an obligatory anaerobic coccobacillus under the family of Coriobacteriaceae. It is a rare cause of pyogenic extraoral infections. We report a 58-year-old lady with good past health presented with fulminant community-acquired pneumonia causing acute respiratory distress syndrome caused by S. exigua requiring veno-venous extra-corporeal membrane oxygenation (VV-ECMO). Bacterial identification can be challenging and often require 16 S rRNA and MALDI-TOF MS. The patient was treated with amoxicillin-clavulanic acid according to sensitivity and made significant recovery.

      PubDate: 2017-07-01T15:30:53Z
      DOI: 10.1016/j.anaerobe.2017.06.017
       
  • Dose-response effects of dietary pequi oil on fermentation characteristics
           and microbial population using a rumen simulation technique (Rusitec)
    • Authors: Andrea Camacho Duarte; Zoey Durmic; Philip E. Vercoe; Alexandre V. Chaves
      Abstract: Publication date: Available online 28 June 2017
      Source:Anaerobe
      Author(s): Andrea Camacho Duarte, Zoey Durmic, Philip E. Vercoe, Alexandre V. Chaves
      The effect of increasing the concentration of commercial pequi (Caryocar brasiliense) oil on fermentation characteristics and abundance of methanogens and fibrolityc bacteria was evaluated using the rumen simulation technique (Rusitec). In vitro incubation was performed over 15 days using a basal diet consisting of ryegrass, maize silage and concentrate in equal proportions. Treatments consisted of control diet (no pequi oil inclusion, 0 g/kg DM), pequi dose 1 (45 g/kg DM), and pequi dose 2 (91 g/kg DM). After a 7 day adaptation period, samples for fermentation parameters (total gas, methane, and VFA production) were taken on a daily basis. Quantitative real time PCR (q-PCR) was used to evaluate the abundance of the main rumen cellulolytic bacteria, as well as abundance of methanogens. Supplementation with pequi oil did not reduce overall methane production (P = 0.97), however a tendency (P = 0.06) to decrease proportion of methane in overall microbial gas was observed. Increasing addition of pequi oil was associated with a linear decrease (P < 0.01) in dry matter disappearance of maize silage. The abundance of total methanogens was unchanged by the addition of pequi oil, but numbers of those belonging to Methanomassiliicoccaceae decreased in liquid-associated microbes (LAM) samples (P < 0.01) and solid-associated microbes (SAM) samples (P = 0.09) respectively, while Methanobrevibacter spp. increased (P < 0.01) only in SAM samples. Fibrobacter succinogenes decreased (P < 0.01) in both LAM and SAM samples when substrates were supplemented with pequi oil. In conclusion, pequi oil was ineffective in mitigating methane emissions and had some adverse effects on digestibility and selected fibrolytic bacteria.

      PubDate: 2017-07-01T15:30:53Z
      DOI: 10.1016/j.anaerobe.2017.06.013
       
  • Microbial analysis of root canal and periradicular lesion associated to
           teeth with endodontic failure
    • Authors: R.S. Pereira; V.A.A. Rodrigues; W.T. Furtado; S. Gueiros; G.S. Pereira; M.J. Avila-Campos
      Abstract: Publication date: Available online 27 June 2017
      Source:Anaerobe
      Author(s): R.S. Pereira, V.A.A. Rodrigues, W.T. Furtado, S. Gueiros, G.S. Pereira, M.J. Avila-Campos
      The quantification of ten microorganisms at the root ends and in the surrounding periradicular lesions was performed. Thirty 3 mm samples root ends and 30 samples of the surrounding chronic periapical infection were collected during apical microsurgery. Samples were triturated, and the bacterial DNA was obtained. The bacterial quantification was performed by using the SYBR Green system. At least one microorganism was detected in all patients. In both the root end and periapical samples, Fusobacterium nucleatum (71.6%), Dialister pneumosintes (58.3%) and Tannerella forsythia (48.3%) were the most prevalent species. Dialister pneumosintes showed statistically significant values in the root end, and F. nucleatum was also significant in the apical periodontitis samples. A statistically significant association between T. forsythia and Porphyromonas gingivalis in the root ends was observed. Bacterial associations from 2 to 7 species were observed in most samples. Extra-radicular and/or intra-radicular infections were present in all teeth with failed endodontic treatment, and showed polymicrobial infection in most cases, with a predominance of F. nucleatum, D. pneumosintes and T. forsythia. When present, Enterococcus faecalis was never found to be the most prevalent species. The presence of a microbial diversity in post-treatment apical periodontitis confirms the polymicrobial and synergistic characteristic of this process. Our results show that the bacterial array associated with the 3 mm root ends and periradicular lesions in post-treatment apical periodontitis are complex and with a high inter-individual variability. These results might be useful to delineate treatment strategies for microbial elimination in apical periodontitis. Further studies are necessary to elucidate the role of these microorganisms in endodontic treatment failures.

      PubDate: 2017-07-01T15:30:53Z
      DOI: 10.1016/j.anaerobe.2017.06.016
       
  • Prevalence of Clostridium perfringens toxin in patients suspected of
           having antibiotic-associated diarrhea
    • Authors: Young Jin Kim; Si Hyun Kim; Junggu Ahn; Soongmoon Cho; Dongchun Kim; Kwanghyun Kim; Heegun Lee; Hyunwoo Son; Hee Joo Lee; Dongeun Yong; Jun Yong Choi; Hye Ran Kim; Jeong Hwan Shin
      Abstract: Publication date: Available online 26 June 2017
      Source:Anaerobe
      Author(s): Young Jin Kim, Si Hyun Kim, Junggu Ahn, Soongmoon Cho, Dongchun Kim, Kwanghyun Kim, Heegun Lee, Hyunwoo Son, Hee Joo Lee, Dongeun Yong, Jun Yong Choi, Hye Ran Kim, Jeong Hwan Shin
      Background Although Clostridium perfringens has been reported as a cause of antibiotic-associated diarrhea (AAD), it is uncommon to detect this pathogen in clinical microbiology laboratories in Korea. The aim of this study was to investigate the prevalence of C. perfringens toxin in patients suspected of having AAD. Methods A total of 135 stool specimens submitted to a clinical microbiology laboratory for C. difficile toxin assay were tested. We tried to detect both C. difficile and C. perfringens toxins using the Seeplex Diarrhea ACE Detection kit (Seegene, Seoul, Korea). We evaluated the prevalence of 10 bacteria and 5 viruses. Results A total of 40 Clostridium spp. were detected in 34 specimens (29.6%). The C. perfringens toxin was detected in 14 of 135 specimens (10.4%), while C. difficile toxin was detected in 26 specimens (19.3%). Other bacteria and viruses, including 8 Aeromonas spp., were detected in 15 specimens. All tests were negative in 92 of the 135 specimens (68.1%). Conclusion Clostridium. perfringens toxin is relatively common, and we should consider the possibility of its presence in patients suspected of having AAD, especially if C. difficile tests are negative.

      PubDate: 2017-07-01T15:30:53Z
      DOI: 10.1016/j.anaerobe.2017.06.015
       
  • Actinomyces radicidentis and Actinomyces haliotis, coccoid Actinomyces
           species isolated from the human oral cavity
    • Authors: Rolf Claesson; Ulf Sjögren; Anders Esberg; Malin Brundin; Margareta Granlund
      Abstract: Publication date: Available online 21 June 2017
      Source:Anaerobe
      Author(s): Rolf Claesson, Ulf Sjögren, Anders Esberg, Malin Brundin, Margareta Granlund
      There are few reports on the bacterial species Actinomyces radicidentis in the literature. In this study, putative A. radicidentis isolates were collected from 16 root canal samples from 601 examined patients. The isolates were examined by biochemical tests, 16S rRNA gene sequencing, Arbitrarily-primed (AP-) PCR, antibiotic susceptibility testing, and MALDI-TOF analyses. In parallel, two A. radicidentis reference strains and two putative A. radicidentis isolates from United Kingdom were tested. Sixteen of the 18 isolates were confirmed as A. radicidentis. The remaining two isolates, both of which were isolated from root canals (one from Sweden and the other from the UK), but were identified as Actinomyces haliotis by sequencing ∼ 1300 base pairs of the 16S rRNA-gene. This isolates had a divergent, but between them similar, AP-PCR pattern, and a common distribution of sequence signatures in the 16S rRNA gene, but were not identified by MALDI-TOF. A. haliotis is a close relative to A. radicidentis, hitherto only been described from a sea-snail. The identity of A. haliotis was confirmed by a phylogenetic tree based on 16S rRNA gene sequences with species specific sequences included, and by additional biochemical tests. The examined bacteria exhibited similar antibiotic susceptibility patterns when tested for 10 separate antibiotic classes with E-tests (bioMérieux). The MIC90 for β-lactams (benzylpenicillin and cefuroxime) and vancomycin was 0.5 mg/L, for colistin and ciprofloxacin 8 mg/mL and for the other antibiotic classes ≤ 25 mg/mL The isolation of A. haliotis from infected dental root canals cast doubt on the accepted opinion that all Actinomyces infections have an endogenous source.

      PubDate: 2017-07-01T15:30:53Z
      DOI: 10.1016/j.anaerobe.2017.06.011
       
  • Temporal microbiota changes of high-protein diet intake in a rat model
    • Authors: Chunlong Mu; Yuxiang Yang; Zhen Luo; Weiyun Zhu
      Abstract: Publication date: Available online 17 June 2017
      Source:Anaerobe
      Author(s): Chunlong Mu, Yuxiang Yang, Zhen Luo, Weiyun Zhu
      Alterations of specific microbes serve as important indicators that link gut health with specific diet intake. Although a six-week high-protein diet (45% protein) upregulates the pro-inflammatory response and oxidative stress in colon of rats, the dynamic alteration of gut microbiota remains unclear. To dissect temporal changes of microbiota, dynamic analyses of fecal microbiota were conducted using a rat model. Adult rats were fed a normal-protein diet or an HPD for 6 weeks, and feces collected at different weeks were used for microbiota and metabolite analysis. The structural alteration of fecal microbiota was observed after 4 weeks, especially for the decreased appearance of bands related to Akkermansia species. HPD increased numbers of Escherichia coli while decreased Akkermansia muciniphila, Bifidobacterium, Prevotella, Ruminococcus bromii, and Roseburia/Eubacterium rectale (P < 0.05), compared to the normal-protein diet. HPD also decreased the copies of genes encoding butyryl-CoA:acetate CoA-transferase and and Prevotella-associated methylmalonyl-CoA decarboxylase α-subunit (P < 0.05). The concentrations of acetate, propionate, and butyrate were decreased by HPD (P < 0.05). Additionally, HPD tended to decrease (P = 0.057) the concentration of IgG in the colonic lumen, which was positively correlated with fecal butyrate at week 6 (P < 0.05). Collectively, this study found the temporal alteration of fecal microbiota related to the decreased numbers and activity of propionate- and butyrate-producing bacteria in feces after the HPD. These findings may provide important reference for linking changes of specific fecal microbes with gut health under high-protein diet.
      Graphical abstract image

      PubDate: 2017-06-21T15:01:25Z
      DOI: 10.1016/j.anaerobe.2017.06.003
       
  • Mikania glomerata Sprengel extract and its major compound ent-kaurenoic
           acid display activity against bacteria present in endodontic infections
    • Authors: Dora Lúcia Carrara Moreti; Luís Fernando Leandro; Thaís da Silva Moraes; Monique Rodrigues Moreira; Rodrigo Cassio Sola Veneziani; Sergio Ricardo Ambrosio; Brenda Paula Figueiredo Almeida Gomes; Carlos Henrique Gomes Martins
      Abstract: Publication date: Available online 13 June 2017
      Source:Anaerobe
      Author(s): Dora Lúcia Carrara Moreti, Luís Fernando Leandro, Thaís da Silva Moraes, Monique Rodrigues Moreira, Rodrigo Cassio Sola Veneziani, Sergio Ricardo Ambrosio, Brenda Paula Figueiredo Almeida Gomes, Carlos Henrique Gomes Martins
      The search for new, effective and safe antimicrobial compounds from plant sources has continued to play an important role in the maintenance of human health since ancient times. Such compounds can be used to help to eradicate microorganisms from the root canal system, preventing/healing periapical diseases. Mikania glomerata (Spreng.), commonly known as “guaco,” is a native climbing plant from Brazil that displays a wide range of pharmacological properties. Many of its activities have been attributed to its phytochemical composition, which is mainly composed of diterpenes, such as ent-kaurenoic acid (KA). The present study evaluated the potential activity of an ent-kaurenoic-rich (KA) extract from Mikania glomerata (i.e. Mikania glomerata extract/MGE) and its major compound KA against bacteria that can cause endodontic infections. Time-kill assays were conducted and the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), anti-biofilm activity, and synergistic antimicrobial activity of MGE and KA were determined. The MGE exhibited MIC and MBC values, which ranged from 6.25 to 100 μg/mL and 12.5 to 200 μg/mL respectively. The MIC and MBC results obtained for the KA, ranged from 3.12 to 100 μg/mL and 3.12 to 200 μg/mL respectively. Time-kill and anti-biofilm activity assays conducted for KA at concentrations between 3.12 and 12.5 μg/mL exhibited bactericidal activity between 6 and 72 h of incubation and 50% inhibition of biofilm formation for Porphyromonas gingivalis (clinical isolate), Propionibacterium acnes (ATCC 6919), Prevotella nigrescens (ATCC 33563), P. melaninogenica (ATCC 25845), Aggregatibacter actinomycetemcomitans (ATCC 43717). For synergistic antimicrobial activity, KA combined with chlorhexidine dichlorohydrate (CHD) had an additive effect with increased efficacy against P. gingivalis (clinical isolate) compared to CHD alone. It was concluded that M. glomerata extract and its major compound ent-kaurenoic acid (KA) showed in vitro antibacterial activity, being the latter a potential biofilm inhibitory agent. They may play important roles in the search for novel sources of agents that can act against bacteria present in endodontic infections.

      PubDate: 2017-06-16T14:51:25Z
      DOI: 10.1016/j.anaerobe.2017.06.008
       
  • Changes in faecal bacteria during fattening in finishing swine
    • Authors: T. Ban-Tokuda; S. Maekawa; T. Miwa; S. Ohkawara; H. Matsui
      Abstract: Publication date: Available online 10 June 2017
      Source:Anaerobe
      Author(s): T. Ban-Tokuda, S. Maekawa, T. Miwa, S. Ohkawara, H. Matsui
      Body fat accumulation in mice and human is linked to the percentage of Firmicutes and Bacteroidetes, two bacterial phyla dominant in the large intestine. However, little is known about the relationship between the composition of the gut microbiota and fattening in pig. This study aimed to investigate the abundance of Firmicutes, Bacteroidetes, and Bacteroides, which is the major genus within Bacteroidetes, in porcine faeces during fattening. Ten 4-month-old crossbred pigs were given free access to commercial feed for fattening and water for 14 weeks. Daily feed intake and body weight were measured every 2 weeks. Faecal samples were collected at 0, 4, 8, and 14 weeks, and plasma samples were collected every 2 weeks. Daily feed intake increased until 8 weeks, and then decreased. Body weight increased with fattening during the experimental period. Feed efficiency showed high values at 0–4 and 6–8 weeks. The level of Firmicutes increased (P < 0.05), whereas those of Bacteroides and Bacteroidetes decreased (P < 0.05) with fattening. The total short chain fatty acid content in the faeces increased (P < 0.05) with fattening until 8 weeks and then decreased (P < 0.05) at 14 weeks. There were no significant relationships between the level of Firmicutes and feed intake or plasma leptin concentration. The levels of Bacteroidetes and Bacteroides correlated with feed intake, body weight, and plasma leptin or plasma urea nitrogen (PUN) concentration. Our results suggested that the level of Firmicutes increased and those of Bacteroidetes and Bacteroides decreased with increase in feed intake and body weight, similar to previous results obtained for mice and human. However, energy extraction from feed was not influenced by compositional alteration of gut flora, because daily gain and feed efficiency did not show high values towards the end of the fattening period. Manipulating the gut microbiota might help improve fattening performance, although further studies are necessary to understand the relationships between the composition of gut microbiota and energy absorption.

      PubDate: 2017-06-12T14:33:00Z
      DOI: 10.1016/j.anaerobe.2017.06.006
       
  • erm gene distribution among Norwegian Bacteroides isolates and evaluation
           of phenotypic tests to detect inducible clindamycin resistance in
           Bacteroides species
    • Authors: Bjørn Odd Johnsen; Nina Handal; Roger Meisal; Jørgen Vildershøj Bjørnholt; Peter Gaustad; Truls Michael Leegaard
      Abstract: Publication date: Available online 8 June 2017
      Source:Anaerobe
      Author(s): Bjørn Odd Johnsen, Nina Handal, Roger Meisal, Jørgen Vildershøj Bjørnholt, Peter Gaustad, Truls Michael Leegaard
      The aims of this study were to describe the distribution of the most common erm genes in a collection of Norwegian Bacteroides isolates and to investigate whether the phenotypic tests for determining inducible clindamycin resistance among Bacteroides species recommended by EUCAST, NordicAST and the manufacturer of E-test®, are effective. We investigated 175 unique Bacteroides isolates for the presence of erm(B), erm(F) and erm(G) genes, determined their minimum inhibitory concentrations (MICs) to clindamycin and categorised their susceptibility according to EUCAST breakpoints. 27 isolates were resistant to clindamycin. Furthermore, we investigated whether these recommended methods could detect inducible resistance in the Bacteroides isolates: 1) EUCAST recommendation: Dissociated resistance to erythromycin (clindamycin susceptible with erythromycin MIC > 32 mg/L), 2) NordicAST recommendation: Double disk diffusion test (DDD) or 3) Manufacturer of E-test®’s recommendation: prolonged incubation of clindamycin E-test® for 48 h. erm genes were detected in 30 (17%, 95% CI 12%–23%) of 175 Bacteroides isolates with erm(F) as the dominating gene. There were six (4%, 95% CI 1%–7%) of 148 clindamycin susceptible isolates harbouring erm genes, they were considered inducibly resistant to clindamycin. None of the methods for phenotypic detection of inducible clindamycin resistance performed satisfactory with sensitivities of 33%, 17% and 0% and specificities of 90%, 99% and 97% for dissociated resistance, DDD and prolonged incubation of clindamycin E-test®, respectively. In our view, the scientific basis for investigating every Bacteroides isolate for inducible resistance to clindamycin is weak. Molecular detection of erm genes may prove a better option than the phenotypic methods we evaluated.

      PubDate: 2017-06-12T14:33:00Z
      DOI: 10.1016/j.anaerobe.2017.06.004
       
  • In vitro emergence of fluoroquinolone resistance in Cutibacterium
           (formerly Propionibacterium) acnes and molecular characterization of
           mutations in the gyrA gene
    • Authors: Takoudju Eve-Marie; Aurélie Guillouzouic; Stanimir Kambarev; Frédéric Pecorari; Stéphane Corvec
      Abstract: Publication date: Available online 8 June 2017
      Source:Anaerobe
      Author(s): Takoudju Eve-Marie, Aurélie Guillouzouic, Stanimir Kambarev, Frédéric Pecorari, Stéphane Corvec
      In vitro occurrence of levofloxacin (LVX) resistance in C. acnes and characterization of its molecular background were investigated. The mutation frequency was determined by inoculation of 108 cfu of C. acnes ATCC 11827 (LVX MIC = 0.25 mg/L) on LVX-containing agar plates. The progressive emergence of resistance was studied by a second exposure to increasing LVX concentrations. For mutants, the QRDR regions including the gyrA and parC genes were sequenced and compared to both C. acnes ATCC 11827 and C. acnes KPA171202 reference sequences (NC006085). The importance of the efflux pump system in resistance was investigated by using inhibitors on selected resistant mutants with no mutation in the QRDR. C. acnes growth was observed on LVX-containing plates with mutation frequencies of 3. 8 cfu × 10−8 (8 × MIC) and 1.6 cfu × 10−7 (4 × MIC). LVX resistance emerged progressively after one-step or two-step assays. In LVX-resistant isolates, the MIC ranged from 0.75 to >32 mg/L. Mutations were detected exclusively in the gyrA gene. Ten genotypes were identified: G99 C, G99 D, D100N, D100 H, D100 G, S101L, S101W, A102 P, D105 H and A105 G. Mutants S101L and S101W were always associated with a high level of resistance. Mutants with no mutation in the QRDR were more susceptible when incubated with an efflux pump inhibitor (phenyl-arginine β-naphthylamide) only, suggesting, for the first time, the expression of such a system in C. acnes LVX-resistant mutants.

      PubDate: 2017-06-12T14:33:00Z
      DOI: 10.1016/j.anaerobe.2017.06.005
       
  • The gut bacterium and pathobiont Bacteroides vulgatus activates NF-κB in
           a human gut epithelial cell line in a strain and growth phase dependent
           manner
    • Authors: Páraic Ó Cuív; Tomas de Wouters; Rabina Giri; Stanislas Mondot; Wendy J. Smith; Hervé M. Blottière; Jakob Begun; Mark Morrison
      Abstract: Publication date: Available online 3 June 2017
      Source:Anaerobe
      Author(s): Páraic Ó Cuív, Tomas de Wouters, Rabina Giri, Stanislas Mondot, Wendy J. Smith, Hervé M. Blottière, Jakob Begun, Mark Morrison
      The gut microbiota is increasingly implicated in the pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC) although the identity of the bacteria that underpin these diseases has remained elusive. The pathobiont Bacteroides vulgatus has been associated with both diseases although relatively little is known about how its growth and functional activity might drive the host inflammatory response. We identified an ATP Binding Cassette (ABC) export system and lipoprotein in B. vulgatus ATCC 8482 and B. vulgatus PC510 that displayed significant sequence similarity to an NF-κB immunomodulatory regulon previously identified on a CD-derived metagenomic fosmid clone. Interestingly, the ABC export system was specifically enriched in CD subjects suggesting that it may be important for colonization and persistence in the CD gut environment. Both B. vulgatus ATCC 8482 and PC510 activated NF-κB in a strain and growth phase specific manner in a HT-29/kb-seap-25 enterocyte like cell line. B. vulgatus ATCC 8482 also activated NF-κB in Caco-2-NF-κBluc enterocyte like and LS174T-NF-κBluc goblet cell like cell lines and induced NF-κB-p65 subunit nuclear translocation and IL-6, IL-8, CXCL-10 and MCP-1 gene expression. Despite this, NF-κB activation was not coincident with maximal expression of the ABC exporter or lipoprotein in B. vulgatus PC510 suggesting that the regulon may be necessary but not sufficient for the immunomodulatory effects.

      PubDate: 2017-06-06T14:11:11Z
      DOI: 10.1016/j.anaerobe.2017.06.002
       
  • Effect of electro-activated aqueous solutions, nisin and moderate heat
           treatment on the inactivation of Clostridium sporogenes PA 3679 spores in
           green beans puree and whole green beans
    • Authors: Omar El Jaam; Ismail Fliss; Mohammed Aïder
      Abstract: Publication date: Available online 31 May 2017
      Source:Anaerobe
      Author(s): Omar El Jaam, Ismail Fliss, Mohammed Aïder
      In this work, the synergistic effect of electro-activated solutions (EAS) of potassium acetate and potassium citrate, nisin and moderate heat treatment to inactivate C. sporogenes PA 3679 spores was evaluated in green beans puree and whole green beans. Electro-activated solutions (EAS) of potassium acetate and potassium citrate were generated under 400 mA during 60 min. They were characterized by an oxidation-reduction potential (ORP) and pH values ranged from +300 to +1090 mV and 2.8 to 3.67, respectively. Moreover, the EAS were combined with a bacteriocin nisin at concentrations of 250, 500, 750 and 1000 IU/mL and the targeted sporicidal effect was evaluated under moderate heat treatment. The inoculated mixtures were subjected to temperatures of 95, 105 and 115 °C for exposure times of 5, 15 and 30 min. After plate counting, the synergistic effect of the hurdle principle composed of electro-activated solutions, nisin and moderate temperatures was demonstrated. The obtained results showed that the synergistic effect of the used hurdle was able to achieve an inactivation efficacy of 5.9–6.1 log CFU/mL. Furthermore, experiments carried out with whole green beans showed that spore inactivation level was significantly higher and reach 6.5 log CFU/mL. Moreover, spore morphology was examined by transmission electron microscopy and the obtained micrographs showed important damages in all of the treated spores.
      Graphical abstract image

      PubDate: 2017-06-02T13:53:46Z
      DOI: 10.1016/j.anaerobe.2017.05.017
       
  • A novel antimicrobial peptide against dental-caries-associated bacteria
    • Authors: Long Chen; Lili Jia; Qiang Zhang; Xirui Zhou; Zhuqing Liu; Bingjie Li; Zhentai Zhu; Fenwei Wang; Changyuan Yu; Qian Zhang; Feng Chen; Shi-Zhong Luo
      Abstract: Publication date: Available online 29 May 2017
      Source:Anaerobe
      Author(s): Long Chen, Lili Jia, Qiang Zhang, Xirui Zhou, Zhuqing Liu, Bingjie Li, Zhentai Zhu, Fenwei Wang, Changyuan Yu, Qian Zhang, Feng Chen, Shi-Zhong Luo
      Dental caries, a highly prevalent oral disease, is primarily caused by pathogenic bacteria infection, and most of them are anaerobic. Herein, we investigated the activity of a designed antimicrobial peptide ZXR-2, and found it showed broad-spectrum activity against a variety of Gram-positive and Gram-negative oral bacteria, particularly the caries-related taxa Streptococcus mutans. Time-course killing assays indicated that ZXR-2 killed most bacterial cells within 5 min at 4 × MIC. The mechanism of ZXR-2 involved disruption of cell membranes, as observed by scanning electron microscopy. Moreover, ZXR-2 inhibited the formation of S. mutans biofilm, but showed limited hemolytic effect. Based on its potent antimicrobial activity, rapid killing, and inhibition of S. mutans biofilm formation, ZXR-2 represents a potential therapeutic for the prevention and treatment of dental caries.

      PubDate: 2017-06-02T13:53:46Z
      DOI: 10.1016/j.anaerobe.2017.05.016
       
  • Impact of Exopolysaccharides (EPSs) of Lactobacillus gasseri strains
           isolated from human vagina on cervical tumor cells (HeLa)
    • Authors: Tolga Sungur; Belma Aslim Cagatay Karaaslan Busra Aktas
      Abstract: Publication date: Available online 26 May 2017
      Source:Anaerobe
      Author(s): Tolga Sungur, Belma Aslim, Cagatay Karaaslan, Busra Aktas
      Lactobacilli, commonly used as probiotics, have been shown to maintain vaginal health and contribute to host microbiota interaction. Exopolysaccharides (EPSs) produced by lactobacillus have been found to have an important role in probiotic activity; however, there is limited knowledge concerning their impact on cervical cancer and urogenital health. The objective of this study is to investigate and compare EPSs of L. gasseri strains (G10 and H15), isolated from a healthy human vagina, for their capability to inhibit cervical cancer cell (HeLa) growth and modulate immune response. HeLa cells were treated with live culture at ∼108 CFU/ml or increasing concentration of lyophilized EPS (L-EPS) (100, 200, or 400 μg/ml) of L. gasseri strains and their ability to adhere to host cells, inhibit proliferation, and modulate immune response were evaluated. Additionally, monosaccharide composition of the L-EPSs produced by L. gasseri strains was determined by HPLC. The sugar component was the same; however, relative proportions of the individual monosaccharides except mannose were different. Although they both produce similar amount of EPS, the most adhesive strain was G10. Both live and L-EPS of L. gasseri strains were capable of inhibiting the cell proliferation of HeLa cells with the impact of L-EPS being strain specific. L-EPSs of L. gasseri strains induced apoptosis in HeLa cells in a strain dependent manner. The ability to induce apoptosis by G10 associated with an upregulation of Bax and Caspase 3. L. gasseri strains showed an anti-inflammatory impact on HeLa cells by decreasing the production of TNF-α and increasing the IL-10 production. In conclusion, diversity in sugar composition of EPS might contribute to adhesion and proliferation properties. Although our results suggest a relationship between the ability of a strain to induce apoptosis and its sugar composition of EPS, further research is required to determine the probiotic mechanisms of action by which L. gasseri strains result in strain specific anti-proliferative activity.

      PubDate: 2017-05-27T13:18:29Z
       
  • Quantification, isolation and characterization of Bifidobacterium from the
           vaginal microbiomes of reproductive aged women
    • Authors: Aline C. Freitas; Janet E. Hill
      Abstract: Publication date: Available online 25 May 2017
      Source:Anaerobe
      Author(s): Aline C. Freitas, Janet E. Hill
      The vaginal microbiome plays an important role in women's reproductive health. Imbalances in this microbiota, such as the poorly defined condition of bacterial vaginosis, are associated with increased susceptibility to sexually transmitted infections and negative reproductive outcomes. Currently, a “healthy” vaginal microbiota in reproductive aged women is understood to be dominated by Lactobacillus, although “atypical” microbiomes, such as Bifidobacterium-dominated profiles, have been described. Despite these observations, vaginal bifidobacteria remain relatively poorly characterized, and questions remain regarding their actual abundance in the microbiome. In this study, we used quantitative PCR to confirm the relative abundance of Bifidobacterium in the vaginal microbiomes of healthy reproductive aged women (n = 42), previously determined by deep sequencing. We also isolated and phenotypically characterized vaginal bifidobacteria (n = 40) in the context of features thought to promote reproductive health. Most isolates were identified as B. breve or B. longum based on cpn60 barcode sequencing. Fermentation patterns of vaginal bifidobacteria did not differ substantially from corresponding type strains of gut or oral origin. Lactic acid was produced by all vaginal isolates, with B. longum strains producing the highest levels, but only 32% of isolates produced hydrogen peroxide. Most vaginal bifidobacteria were also able to tolerate high levels of lactic acid (100 mM) and low pH (4.5 or 3.9), conditions typical of vaginal fluid of healthy women. Most isolates were resistant to metronidazole but susceptible to clindamycin, the two most common antibiotics used to treat vaginal dysbiosis. These findings demonstrate that Bifidobacterium is the dominant member of some vaginal microbiomes and suggest that bifidobacteria have the potential to be as protective as lactobacilli according to the current understanding of a healthy vaginal microbiome.

      PubDate: 2017-05-27T13:18:29Z
      DOI: 10.1016/j.anaerobe.2017.05.012
       
  • Molecular characterization and antimicrobial resistance profile of
           Clostridium perfringens type A isolates from humans, animals, fish and
           their environment
    • Authors: Jay Prakash Yadav; Suresh Chandra Das; Pankaj Dhaka; Deepthi Vijay; Manesh Kumar; Asish Kumar Mukhopadhyay; Goutam Chowdhury; Pranav Chauhan; Rahul Singh; Kuldeep Dhama; Satya Veer Singh Malik; Ashok Kumar
      Abstract: Publication date: Available online 17 May 2017
      Source:Anaerobe
      Author(s): Jay Prakash Yadav, Suresh Chandra Das, Pankaj Dhaka, Deepthi Vijay, Manesh Kumar, Asish Kumar Mukhopadhyay, Goutam Chowdhury, Pranav Chauhan, Rahul Singh, Kuldeep Dhama, Satya Veer Singh Malik, Ashok Kumar
      The study was aimed to characterize, and determine antibiogram of C. perfringens type A isolated from the feces of human and animal diarrhoeal cases, as well as healthy animals, meat of pigs and goats, gills and intestine of fish and samples from fish pond. A total of 460 samples, including human diarrhoeal cases (n = 130); diarrhoeal cases of pig (n = 52) and goat (n = 50); fecal samples from healthy pig (n = 50) and goat (n = 50); meat samples viz. pork meat (n = 52); goat meat (n = 50) and fish including their environmental sources (n = 26) were used for isolation and identification of C. perfringens type A. All the biochemically confirmed isolates were positive for species-specific 16S rRNA and cpa genes by PCR assays. Toxinotyping of C. perfringens type A isolates showed that overall prevalence of C. perfringens type A with only cpa + gene was 43.2%; with cpa + and cpb2 + genes was 45.4%; with cpa + and cpe + genes was 4.9%; however, with cpa + , cpb2 + and cpe + genes was 6.6%. Antimicrobial susceptibility testing revealed that 83.7% of isolates were resistant to three or more antibiotics.

      PubDate: 2017-05-17T12:57:26Z
      DOI: 10.1016/j.anaerobe.2017.05.009
       
  • Mixed species biofilms of Fusobacterium necrophorum and Porphyromonas
           levii impair the oxidative response of bovine neutrophils in vitro
    • Authors: Joey S. Lockhart; Andre G. Buret; Howard Ceri; Douglas G. Storey; Stefanie J. Anderson; Douglas W. Morck
      Abstract: Publication date: Available online 17 May 2017
      Source:Anaerobe
      Author(s): Joey S. Lockhart, Andre G. Buret, Howard Ceri, Douglas G. Storey, Stefanie J. Anderson, Douglas W. Morck
      Biofilms composed of anaerobic bacteria can result in persistent infections and chronic inflammation. Host immune cells have difficulties clearing biofilm-related infections and this can result in tissue damage. Neutrophils are a vital component of the innate immune system and help clear biofilms. The comparative neutrophilic response to biofilms versus planktonic bacteria remains incompletely understood, particularly in the context of mixed infections. The objective of this study was to generate mixed species anaerobic bacterial biofilms composed of two opportunistic pathogens, Fusobacterium necrophorum and Porphyromonas levii, and evaluate neutrophil responses to extracellular fractions from both biofilms and planktonic cell co-cultures of the same bacteria. Purified bovine neutrophils exposed to culture supernatants from mixed species planktonic bacteria showed elevated oxidative activity compared to neutrophils exposed to biofilms composed of the same bacteria. Bacterial lipopolysaccharide plays a significant role in the stimulation of neutrophils; biofilms produced substantially more lipopolysaccharide than planktonic bacteria under these experimental conditions. Removal of lipopolysaccharide significantly reduced neutrophil oxidative response to culture supernatants of planktonic bacteria. Oxidative responses to LPS-removed biofilm supernatants and LPS-removed planktonic cell supernatants were similar. The limited neutrophil response to biofilm bacteria observed in this study supports the reduced ability of the innate immune system to eradicate biofilm-associated infections. Lipopolysaccharide is likely important in neutrophil response; however, the presence of other extracellular, immune modifying molecules in the bacterial media also appears to be important in altering neutrophil function.

      PubDate: 2017-05-17T12:57:26Z
      DOI: 10.1016/j.anaerobe.2017.05.008
       
  • Molecular typing of Clostridium difficile isolates cultured from patient
           stool samples and gastroenterological medical devices in a single Iranian
           hospital
    • Authors: Masoumeh Azimirad; Marcela Krutova; Otakar Nyc; Zahra Hasani; Leili Afrisham; Masoud Alebouyeh; Mohammad Reza Zali
      Abstract: Publication date: Available online 10 May 2017
      Source:Anaerobe
      Author(s): Masoumeh Azimirad, Marcela Krutova, Otakar Nyc, Zahra Hasani, Leili Afrisham, Masoud Alebouyeh, Mohammad Reza Zali
      This study aimed to characterize Clostridium difficile isolates cultured from stool samples of patients with C. difficile infection (CDI) and swabs from a medical environment in a gastroenterology centre in Tehran, Iran. A total of 158 samples (105 stool samples from hospitalized patients and 53 swabs from medical devices and the environment) were collected from January 2011 to August 2011 and investigated for the presence of C. difficile by direct anaerobic culture on a selective media for C. difficile. C. difficile isolates were further characterized by capillary electrophoresis (CE) ribotyping and toxin gene multiplex PCR. Of 158 samples, C. difficile was cultured in 19 of 105 stool samples (18%) and in 4 of 53 swabs (7.5%). C. difficile PCR ribotype (RT) 126 was the most common RT in the study (21.7%). Further RTs were: 001, 003, 014, 017, 029, 039, 081, 103 and 150. RTs 126, 001, 150 were cultured from both the stool samples and swabs of medical devices and the hospital environment which suggest a possible route of transmission.

      PubDate: 2017-05-12T12:54:52Z
      DOI: 10.1016/j.anaerobe.2017.05.004
       
  • Tolerance mechanisms of human-residential bifidobacteria against lysozyme
    • Authors: Takuma Sakurai; Nanami Hashikura; Junichi Minami; Akio Yamada; Toshitaka Odamaki; Jin-zhong Xiao
      Abstract: Publication date: Available online 3 May 2017
      Source:Anaerobe
      Author(s): Takuma Sakurai, Nanami Hashikura, Junichi Minami, Akio Yamada, Toshitaka Odamaki, Jin-zhong Xiao
      We previously reported that lysozyme present in breast milk is a selection factor for bifidobacterial colonization in infant human intestines. This study is aimed at examining their underlying mechanisms. Human-residential bifidobacteria (HRB) generally exhibited higher tolerance than non-HRB to lysozymes, except B. bifidum subspecies. To assess the involvement of enzymatic activity of lysozyme, peptidoglycan (PG) was isolated and the degree of O-acetylation (O-Ac) in 19 strains, including both HRB and non-HRB, was determined. Variety in the degree of O-Ac was observed among each of the Bifidobacterium species; however, all purified PGs were found to be tolerant to lysozyme, independent of their O-Ac degree. In addition, De-O-Ac of PGs affected the sensitivity to lysozyme of only B. longum-derived PG. To examine the non-enzymatic antibacterial activity of lysozyme on bifidobacteria, lysozyme was heat-denatured. The HRB and non-HRB strains exhibited similar patterns of susceptibility to intact lysozyme as they did to heat-denatured lysozyme. In addition, strains of B. bifidum (30 strains), which showed various tolerance of lysozyme, also exhibited similar patterns of susceptibility to intact lysozyme as they did to heat-denatured lysozyme. These results suggest that bifidobacteria are resistant to the peptidoglycan-degrading property of lysozyme, and the tolerance to lysozyme among some HRB strains is due to resistance to the non-enzymatic antibacterial activity of lysozyme.

      PubDate: 2017-05-07T12:51:34Z
      DOI: 10.1016/j.anaerobe.2017.05.001
       
  • A combination of the probiotic and prebiotic product can prevent the
           germination of Clostridium difficile spores and infection
    • Authors: M. Rätsep; S. Kõljalg; E. Sepp; I. Smidt; K. Truusalu; E. Songisepp; J. Stsepetova; P. Naaber; R.H. Mikelsaar; M. Mikelsaar
      Abstract: Publication date: Available online 29 April 2017
      Source:Anaerobe
      Author(s): M. Rätsep, S. Kõljalg, E. Sepp, I. Smidt, K. Truusalu, E. Songisepp, J. Stsepetova, P. Naaber, R.H. Mikelsaar, M. Mikelsaar
      Clostridium difficile infection (CDI) is one of the most prevalent healthcare associated infections in hospitals and nursing homes. Different approaches are used for prevention of CDI. Absence of intestinal lactobacilli and bifidobacteria has been associated with C. difficile colonization in hospitalized patients. Our aim was to test a) the susceptibility of C. difficile strains of different origin and the intestinal probiotic Lactobacillus plantarum Inducia (DSM 21379) to various antimicrobial preparations incl. metronidazole, vancomycin; b) the susceptibility of C. difficile strains to antagonistic effects of the probiotic L. plantarum Inducia, prebiotic xylitol (Xyl) and their combination as a synbiotic (Syn) product; c) the suppression of germination of C. difficile spores in vitro and in vivo in animal model of C. difficile infection with Inducia, Xyl and Syn treatment. The VPI strain 10463 (ATCC 43255), epidemic strain (M 13042) and clinical isolates (n = 12) of C. difficile from Norway and Estonia were susceptible and contrarily L. plantarum Inducia resistant to vancomycin, metronidazole and ciprofloxacin. The intact cells of Inducia, natural and neutralized cell free supernatant inhibited in vitro the growth of tested C. difficile reference strain VPI and Estonian and Norwegian clinical isolates of C. difficile after co-cultivation. This effect against C. difficile sustained in liquid media under ampicillin (0.75 μg/ml) and Xyl (5%) application. Further, incubation of Inducia in the media with 5% Xyl fully stopped germination of spores of C. difficile VPI strain after 48 h. In infection model the 48 hamsters were administered ampicillin (30 mg/kg) and 10–30 spores of C. difficile VPI strain. They also received five days before and after the challenge a pretreatment with a synbiotic (single daily dose of L. plantarum Inducia 1 ml of 1010 CFU/ml and 20% xylitol in 1 ml by orogastric gavage). The survival rate of hamsters was increased to 78% compared to 13% (p = 0.003) survival rate of specimens who received no treatment. When administered Xyl the survival rate of hamsters reached 56% vs.13% (p = 0.06). In both Syn (6/9, p = 0.003) and Xyl (3/9, p = 0.042) groups the number of specimens not colonized with C. difficile significantly increased. In conclusion, the combination of xylitol with L. plantarum Inducia suppresses the germination of spores and outgrowth into vegetative toxin producing cells of C. difficile and reduces the colonization of gut with the pathogen. Putative therapeutical approach includes usage of the synbiotic during antimicrobial therapy for prevention of CDI and its potential to reduce recurrences of CDI.

      PubDate: 2017-05-02T12:45:07Z
      DOI: 10.1016/j.anaerobe.2017.03.019
       
  • Tropism and virulence of Cutibacterium (formerly Propionibacterium) acnes
           involved in implant-associated infection
    • Authors: Guillaume Ghislain Aubin; Jean-Philippe Lavigne; Yohan Foucher; Sarah Dellière; Didier Lepelletier; François Gouin; Stéphane Corvec
      Abstract: Publication date: Available online 25 April 2017
      Source:Anaerobe
      Author(s): Guillaume Ghislain Aubin, Jean-Philippe Lavigne, Yohan Foucher, Sarah Dellière, Didier Lepelletier, François Gouin, Stéphane Corvec
      The recognition of the pathogenicity of Cutibacterium acnes in implant-associated infection is not always obvious. In this paper, we aimed to distinguish pathogenic and non-pathogenic C. acnes isolates. To reach this goal, we investigated the clonal complex (CC) of a large collection of C. acnes clinical isolates through Multi-Locus Sequence Typing (MLST), we established a Caenorhabditis elegans model to assess C. acnes virulence and we investigated the presence of virulence factors in our collection. Ours results showed that CC36 and CC53 C. acnes isolates were more frequently observed in prosthetic joint infections (PJI) than CC18 and CC28 C. acnes isolates (p = 0.021). The C. elegans model developed here showed two distinct virulence groups of C. acnes (p < 0.05). These groups were not correlated to CC or clinical origin. Whole genome sequencing allowed us to identify a putative gene linked to low virulent strains. In conclusion, MLST remains a good method to screen pathogenic C. acnes isolates according to their clinical context but mechanisms of C. acnes virulence need to be assess thought transcriptomic analysis to investigate regulatory process.

      PubDate: 2017-04-25T12:31:39Z
      DOI: 10.1016/j.anaerobe.2017.04.009
       
  • Antimicrobial resistance in the Bacteroides fragilis group in faecal
           samples from patients receiving broad-spectrum antibiotics
    • Authors: Kia Cirkeline Møller Hansen; Simon A.F. Schwensen; Daniel Pilsgaard Henriksen; Ulrik Stenz Justesen; Thomas Vognbjerg Sydenham
      Abstract: Publication date: Available online 23 April 2017
      Source:Anaerobe
      Author(s): Kia Cirkeline Møller Hansen, Simon A.F. Schwensen, Daniel Pilsgaard Henriksen, Ulrik Stenz Justesen, Thomas Vognbjerg Sydenham
      Members of the Bacteroides fragilis group are opportunistic pathogens and cause severe infections including bacteraemia. As increased levels of antimicrobial resistance in B. fragilis group bacteria can be detected years after administration of specific antibiotics, monitoring antimicrobial susceptibility in the gut microbiota could be important. The objectives of this study were to 1) investigate the distribution of species and the occurrence of reduced antimicrobial susceptibility in the B. fragilis group from patients treated at departments with a high level of antibiotic use, 2) to determine the prevalence of the carbapenem resistance gene cfiA in B. fragilis in this patient group, and 3) to determine the association between previous antibiotic treatment and reduced susceptibility to clindamycin, meropenem, metronidazole, and piperacillin-tazobactam. Consecutive faecal samples (n = 197) were collected from patients at the departments of haematology, oncology, and infectious diseases at Odense University Hospital, Denmark. Three colonies from each sample were identified by Matrix Assisted Lazer Desorption Ionization Time of Flight Mass Spectrometry and isolates were screened for resistance to clindamycin, meropenem, metronidazole, and piperacillin-tazobactam. B. fragilis isolates were tested for the cfiA metallo-beta-lactamase gene. Fisher's Exact test was used to test for correlation between antimicrobial exposure and reduced susceptibility. A total of 359 isolates were tested for reduced susceptibility. Of these 28%, 5%, <1%, and 11% were intermediate susceptible or resistant to clindamycin, meropenem, metronidazole, and piperacillin-tazobactam respectively. Three metronidazole resistant Bacteroides spp. were isolated. The proportion of B. fragilis belonging to division II (cfiA+) was 5.3%. Previous exposure to meropenem was associated with reduced susceptibility to meropenem (p= 0.001). In conclusion, antimicrobial resistance is prevalent and the distribution of species appears to be affected in the B. fragilis group from patients receiving broad-spectrum antibiotics, with meropenem exposure being associated with meropenem resistance.

      PubDate: 2017-04-25T12:31:39Z
      DOI: 10.1016/j.anaerobe.2017.04.013
       
  • Performance of MALDI-TOF MS for identification of oral Prevotella species
    • Authors: Mervi Gürsoy; Inka Harju; Jaakko Matomäki; Anne Bryk; Eija Könönen
      Abstract: Publication date: Available online 21 April 2017
      Source:Anaerobe
      Author(s): Mervi Gürsoy, Inka Harju, Jaakko Matomäki, Anne Bryk, Eija Könönen
      During the past decade, the clinically relevant genus Prevotella has expanded considerably. Prevotella species can be isolated from nearly all types of oral infections but also from various non-oral infections. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been introduced in clinical microbiology laboratories as a convenient method for identifying bacterial isolates from clinical specimens. Here we tested the diagnostic accuracy of a total of 123 oral Prevotella isolates, selected based on their biochemical profile, by Bruker MALDI-TOF MS. Partial 16S rRNA sequencing was used as a reference method. The performance of MALDI-TOF MS to identify the isolates to the genus level was excellent with 100.0% accuracy, while a good identification rate of 88.6% was achieved to the species level with a log score of ≥2.0. The isolates representing P. aurantiaca and P. jejuni, which are currently missing from the MALDI BioTyper database, were identified correctly to the genus level. Of the 123 isolates, one P. pallens isolate (0.8%) was identified with a score variation of 1.7–1.999. Overall, biochemical testing produced a high proportion (70.7%) of incorrect identifications within different species. MALDI-TOF MS offers a reliable and rapid method for the identification of Prevotella species included in the database.

      PubDate: 2017-04-25T12:31:39Z
      DOI: 10.1016/j.anaerobe.2017.04.008
       
  • Antimicrobial susceptibility of Bacteroides fragilis group organisms in
           Hong Kong by the tentative EUCAST disc diffusion method
    • Authors: Pak-Leung Ho; Chong-Yee Yau; Lok-Yan Ho; Eileen Ling-Yi Lai; Melissa Chun-Jiao Liu; Cindy Wing-Sze Tse; Kin-Hung Chow
      Abstract: Publication date: Available online 14 April 2017
      Source:Anaerobe
      Author(s): Pak-Leung Ho, Chong-Yee Yau, Lok-Yan Ho, Eileen Ling-Yi Lai, Melissa Chun-Jiao Liu, Cindy Wing-Sze Tse, Kin-Hung Chow
      This study used a recently developed EUCAST disc diffusion method to measure the susceptibility of 741 B. fragilis group isolates to six antibiotics. Isolates nonsusceptible to imipenem and metronidazole by the disc method were further investigated by E-test. Species identification was obtained by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), PCR assays and 16S rRNA sequencing. The most common species were B. fragilis (n = 424, including 81 division II and 343 division I isolates), B. thetaiotaomicron (n = 111), B. ovatus (n = 53) and B. vulgatus (n = 46). Overall, metronidazole following by imipenem and amoxicillin-clavulanate are the most active agents with over 90% of all the isolates being susceptible at the tentative disc breakpoints. Susceptibility rates for moxifloxacin (69.5%), piperacillin-tazobactam (58.2%) and clindamycin (37.2%) were much lower. Metronidazole is the only agent active against >90% of B. fragilis, non-fragilis Bacteroides and Parabacteroides isolates. With the exception of B. fragilis division II, imipenem was active against 88.0%–98.3% of isolates of the other species. Susceptibility rates for clindamycin (14.4%–54.3%) and moxifloxacin (33.3%–80.6%) were low across all species and many isolates had no inhibition zone around the discs. E-test testing confirmed 8.2% (61/741) and 1.6% (12/741) isolates as nonsusceptible to imipenem and metronidazole, respectively with B. fragilis and B. thetaoiotaomicron accounting for a large share of the observed resistance to both agents. Two imipenem-resistant and one metronidazole-resistant B. dorei were misidentified as B. vulgatus by MALDI-TOF MS. These data highlights the importance anaerobic susceptibility testing in clinical laboratories to guide therapy.

      PubDate: 2017-04-18T12:09:26Z
      DOI: 10.1016/j.anaerobe.2017.04.005
       
  • Bifidobacterium longum vertebrodiscitis in a patient with cirrhosis and
           prostate cancer
    • Authors: Heather L. Wilson; Chong Wei Ong
      Abstract: Publication date: Available online 10 April 2017
      Source:Anaerobe
      Author(s): Heather L. Wilson, Chong Wei Ong
      Bifidobacterium species are anaerobic, Gram-positive bacilli that colonize the human intestinal tract and oral cavity. They are an infrequent cause of invasive human infection. We report a case of Bifidobacterium longum lumbar vertebrodiscitis in a 71 year old man who was subsequently diagnosed with liver cirrhosis and prostate cancer. The clinical outcome was good following antibiotic treatment with penicillin and clindamycin. The laboratory identification of Bifidobacterium species and risk factors for invasive infection are discussed.

      PubDate: 2017-04-11T11:45:07Z
      DOI: 10.1016/j.anaerobe.2017.04.004
       
  • Rumen microbial and fermentation characteristics are affected differently
           by acarbose addition during two nutritional types of simulated severe
           subacute ruminal acidosis in vitro
    • Authors: Yue Wang; Junhua Liu; Yuyang Yin; Weiyun Zhu; Shengyong Mao
      Abstract: Publication date: Available online 7 April 2017
      Source:Anaerobe
      Author(s): Yue Wang, Junhua Liu, Yuyang Yin, Weiyun Zhu, Shengyong Mao
      Little information is available on whether or not the effect of an alpha-glucosidase inhibitor on the prevention of ruminal acidosis is influenced by the type of diet during ruminant feeding. This study was conducted to explore the effect of acarbose addition on the prevention of severe subacute ruminal acidosis induced by either cracked wheat or beet pulp in vitro. Cracked wheat and beet pulp were fermented in vitro by rumen microorganisms obtained from three dairy cows. When cracked wheat was used as the substrate and fermented for 24 h, compared with the control, acarbose addition decreased the concentrations of acetate, propionate, butyrate, total volatile fatty acids, and lactate (P < 0.05), while linearly increasing the ratio of acetate to propionate, pH value and, the ammonia-nitrogen level (P < 0.05). Applying Illumina MiSeq sequencing of a fragment of the 16S rRNA gene revealed that the relative abundance of Firmicutes and Bacteroidetes as well as the ACE (abundance-based coverage estimator) value, Chao 1 value, and Shannon index increased significantly (P < 0.05), while there was a significant reduction (P < 0.05) in the relative abundance of Tenericutes as well as Proteobacteria after adding acarbose compared to the control. On the other hand, when beet pulp was used as the substrate, acarbose addition had no significant effects (P > 0.05) on the fermentation parameters and the Chao 1 value, the Shannon index, and the proportion of Firmicutes and Bacteroidetes. In general, these findings indicate that acarbose had more effects on ruminal fermentation when wheat was used as the substrate, whereas it exhibited little effect on ruminal fermentation when beet pulp was used as the substrate.

      PubDate: 2017-04-11T11:45:07Z
      DOI: 10.1016/j.anaerobe.2017.04.003
       
  • The effect of penicillin administration in early life on murine gut
           microbiota and blood lymphocyte subsets
    • Authors: Jaroslaw Daniluk; Urszula Daniluk; Malgorzata Rusak; Milena Dabrowska; Joanna Reszec; Magdalena Garbowicz; Kinga Humińska; Andrzej Dabrowski
      Abstract: Publication date: Available online 18 March 2017
      Source:Anaerobe
      Author(s): Jaroslaw Daniluk, Urszula Daniluk, Malgorzata Rusak, Milena Dabrowska, Joanna Reszec, Magdalena Garbowicz, Kinga Humińska, Andrzej Dabrowski
      Background and aim Antibiotics have many beneficial effects but their uncontrolled use may lead to increased risk of serious diseases in the future. Our hypothesis is that an early antibiotic exposition may affect immune system by altering gut microbiota. Therefore, the aim of the study was to determine the effect of penicillin treatment on gut microorganisms and immune system of mice. Methods: 21-days old C57BL6/J/cmdb male mice were treated with low-dose of penicillin (study group) or water only (control group) for 4 weeks. Tissue and stool samples for histology or microbiome assessment and peripheral blood for CBC and flow cytometry evaluation were collected. Results: We found high variability in microbiota composition at different taxonomic levels between littermate mice kept in the same conditions, independently of treatment regimen. Interestingly, low-dose of penicillin caused significant increase of Parabacteroides goldsteinii in stool and in colon tissue in comparison to control group (9.5% vs. 4.9%, p = 0.008 and 10.7% vs. 6.1%, p = 0.008, respectively). Moreover, mice treated with penicillin demonstrated significantly elevated percentage of B cells (median 10.5% vs 8.0%, p = 0.01) and decrease in the percentage of total CD4+ cell (median 75.4% vs 82.5%, p = 0.0039) with subsequent changes among subsets - increased percentage of regulatory T cells (Treg), T helper 1 (Th1) and T helper 2 (Th2) cells. Conclusion: Our study showed significant effect of penicillin on B and T cells in peripheral blood of young mice. This effect may be mediated through changes in gut microbiota represented by the expansion of Parabacteroides goldsteinii.

      PubDate: 2017-03-20T21:19:39Z
      DOI: 10.1016/j.anaerobe.2017.03.015
       
  • Effect of operating temperature on anaerobic digestion of the Brazilian
           waterweed Egeria densa and its microbial community
    • Authors: Keiko Watanabe; Mitsuhiko Koyama; Junko Ueda; Syuhei Ban; Norio Kurosawa; Tatsuki Toda
      Abstract: Publication date: Available online 16 March 2017
      Source:Anaerobe
      Author(s): Keiko Watanabe, Mitsuhiko Koyama, Junko Ueda, Syuhei Ban, Norio Kurosawa, Tatsuki Toda
      To develop an effective treatment for the globally invasive Brazilian waterweed Egeria densa, anaerobic digestion was observed at 37 °C, 55 °C, and 65 °C. The average methane production rate at 55 °C was 220 mL L−1 day−1, which was two-fold that at 37 °C and 65 °C. Volatile fatty acid accumulation was detected under thermophilic conditions; however, although there was methane production, the system did not shutdown. The microbial communities differed between mesophilic (37 °C) and thermophilic (55 °C and 65 °C) conditions. A bacterial community consisting of the phyla Bacteroidetes (43%), Firmicutes (37%), Proteobacteria (9%), Synergistetes (5%), Spirochaetes (1%), and unclassified bacteria (5%) were detected under mesophilic condition. In contrast, the phylum Firmicutes was dominant under thermophilic conditions. In the archaeal community, Methanosaeta concilii (40%), Methanolinea sp. (17%), and unclassified euryarchaeota (43%) were detected under mesophilic condition. Methanosarcina thermophila (87% at 55 °C, 54% at 65 °C) and Methanothermobacter thermautotrophicus (13% at 55 °C, 46% at 65 °C) were detected under thermophilic conditions. At both 37 °C and 55 °C, acetoclastic methanogenesis likely occurred because of the lower abundance of hydrogenotrophic methanogens. At 65 °C, the growth of the acetoclastic methanogen Methanosarcina thermophila was limited by the high temperature, therefore, acetate oxidation and hydrogenotrophic methanogenesis may have occurred.

      PubDate: 2017-03-20T21:19:39Z
      DOI: 10.1016/j.anaerobe.2017.03.014
       
  • Characterization of vaginal Lactobacillus species by rplK -based multiplex
           qPCR in Russian women
    • Authors: Vladimir V. Demkin; Stanislav I. Koshechkin
      Abstract: Publication date: Available online 14 March 2017
      Source:Anaerobe
      Author(s): Vladimir V. Demkin, Stanislav I. Koshechkin
      We describe a multiplex qPCR assay for identification and quantitative assessment of a set of vaginal Lactobacillus species, including L. acidophilus, L. crispatus, L. gasseri, L. helveticus, L. iners, and L. jensenii. The assay extends the previously developed qPCR method for Lactobacillus detection and total quantification based on targeting the rplK gene. Both assays use only single pair of primers and a set of probes combined in three reactions, comprising a vaginal Lactobacillus diagnostic assay panel. The utility of the diagnostic panel was evaluated by analyzing of vaginal swab specimens from 145 patients with different status of vaginal health. Most frequently, only one Lactobacillus species was dominant (68,9%), mostly L. crispatus (18,6%) or L. iners (33,1%), but two or three Lactobacillus species were also being simultaneously detected (24,9%). The diagnostic panel will facilitate investigations of the role of Lactobacillus species in the health of the female reproductive system and promote studies of variability of the vaginal microbiota.

      PubDate: 2017-03-20T21:19:39Z
      DOI: 10.1016/j.anaerobe.2017.03.011
       
  • Distribution and phylogeny of Brachyspira spp. in human intestinal
           spirochetosis revealed by FISH and 16S rRNA-gene analysis
    • Authors: Pablo Rojas; Annett Petrich; Julia Schulze; Alexandra Wiessner; Christoph Loddenkemper; Hans-Jörg Epple; William Sterlacci; Michael Vieth; Judith Kikhney; Annette Moter
      Abstract: Publication date: Available online 12 March 2017
      Source:Anaerobe
      Author(s): Pablo Rojas, Annett Petrich, Julia Schulze, Alexandra Wiessner, Christoph Loddenkemper, Hans-Jörg Epple, William Sterlacci, Michael Vieth, Judith Kikhney, Annette Moter
      During six years as National Reference Laboratory for Spirochetes we investigated 149 intestinal biopsies from 91 patients, which were histopathologically diagnosed with human intestinal spirochetosis (HIS), using fluorescence in situ hybridization (FISH) combined with 16S rRNA gene PCR and sequencing. Aim of this study was to complement histopathological findings with FISH and PCR for definite diagnosis and species identification of the causative pathogens. HIS is characterized by colonization of the colonic mucosa of the human distal intestinal tract by Brachyspira spp. Microbiological diagnosis of HIS is not performed, because of the fastidious nature and slow growth of Brachyspira spp. in culture. In clinical practice, diagnosis of HIS relies solely on histopathology without differentiation of the spirochetes. We used a previously described FISH probe to detect and identify Brachyspira spp. in histological gut biopsies. FISH allowed rapid visualization and identification of Brachyspira spp. in 77 patients. In most cases, the bright FISH signal already allowed rapid localization of Brachyspira spp. at 400× magnification. By sequencing, 53 cases could be assigned to the B. aalborgi lineage including “B. ibaraki” and “B. hominis”, and 23 cases to B. pilosicoli. One case showed mixed colonization. The cases reported here reaffirm all major HIS Brachyspira spp. clusters already described. However, the phylogenetic diversity seems to be even greater than previously reported. In 14 cases, we could not confirm HIS by either FISH or PCR, but found colonization of the epithelium by rods and cocci, indicating misdiagnosis by histopathology. FISH in combination with molecular identification by 16S rRNA gene sequencing has proved to be a valuable addition to histopathology. It provides definite diagnosis of HIS and allows insights into phylogeny and distribution of Brachyspira spp. HIS should be considered as a differential diagnosis in diarrhea of unknown origin, particularly in patients from risk groups (e.g. patients with colonic adenomas, inflammatory polyps, inflammatory bowel disease or HIV infection and in men who have sex with men).

      PubDate: 2017-03-12T17:58:06Z
      DOI: 10.1016/j.anaerobe.2017.03.012
       
 
 
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