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  Subjects -> BIOLOGY (Total: 2840 journals)
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BIOLOGY (1385 journals)            First | 1 2 3 4 5 6 7 8 | Last

Developmental Dynamics     Hybrid Journal   (Followers: 2)
Developmental Neurobiology     Hybrid Journal   (Followers: 4)
Developments in Marine Biology     Full-text available via subscription   (Followers: 9)
Dhaka University Journal of Biological Sciences     Open Access  
Diatom Research     Hybrid Journal  
Differentiation     Hybrid Journal   (Followers: 1)
Disease Models and Mechanisms     Open Access   (Followers: 1)
DNA and Cell Biology     Hybrid Journal   (Followers: 4)
DNA Repair     Hybrid Journal   (Followers: 2)
DNA Research     Open Access   (Followers: 2)
Doklady Physics     Hybrid Journal   (Followers: 1)
Drug Discovery Today     Full-text available via subscription   (Followers: 94)
Drug Discovery Today: Disease Mechanisms     Full-text available via subscription   (Followers: 7)
Drug Discovery Today: Disease Models     Full-text available via subscription   (Followers: 6)
Drug Discovery Today: Technologies     Full-text available via subscription   (Followers: 11)
Drug Discovery Today: Therapeutic Strategies     Full-text available via subscription   (Followers: 9)
Drug Resistance Updates     Hybrid Journal   (Followers: 4)
e-Neuroforum     Hybrid Journal  
Ecohydrology & Hydrobiology     Full-text available via subscription   (Followers: 4)
Ecología en Bolivia     Open Access  
Ecological Engineering     Hybrid Journal   (Followers: 2)
Ecology and Society     Open Access   (Followers: 28)
Ecology Letters     Hybrid Journal   (Followers: 171)
Economics & Human Biology     Hybrid Journal  
Ecoprint : An International Journal of Ecology     Open Access  
Ecoscience     Full-text available via subscription   (Followers: 2)
Educational Technology Research and Development     Partially Free   (Followers: 79)
Egyptian Journal of Basic and Applied Sciences     Open Access  
Egyptian Journal of Biology     Open Access  
Egyptian Journal of Histology     Partially Free   (Followers: 1)
Egyptian Journal of Natural History     Open Access   (Followers: 1)
EJNMMI Research     Open Access   (Followers: 1)
Electromagnetic Biology and Medicine     Hybrid Journal   (Followers: 1)
eLife     Open Access   (Followers: 22)
el–Hayah     Open Access   (Followers: 1)
Embo Molecular Medicine     Open Access   (Followers: 4)
EMBO reports     Full-text available via subscription   (Followers: 17)
Emotion Review     Hybrid Journal   (Followers: 13)
Endocrine Connections     Open Access   (Followers: 4)
Engineering & Technology     Hybrid Journal   (Followers: 19)
Engineering Economist, The     Hybrid Journal   (Followers: 2)
Engineering in Life Sciences     Hybrid Journal   (Followers: 4)
Engineering Optimization     Hybrid Journal   (Followers: 7)
Ensaios e Ciência: Ciências Biológicas, Agrárias e da Saúde     Open Access  
Environmental Biology of Fishes     Hybrid Journal   (Followers: 4)
Environmental Biosafety Research     Hybrid Journal   (Followers: 1)
Environmental Microbiology     Hybrid Journal   (Followers: 14)
Environmental Science & Technology     Full-text available via subscription   (Followers: 157)
Enzyme and Microbial Technology     Hybrid Journal   (Followers: 5)
Enzyme Research     Open Access   (Followers: 4)
Epidemiology & Infection     Hybrid Journal   (Followers: 13)
Epigenetics in Cancer     Open Access  
EPMA Journal     Open Access  
ESHRE Monographs     Hybrid Journal  
Ethiopian Journal of Biological Sciences     Open Access   (Followers: 3)
Ethnobiology and Conservation     Open Access   (Followers: 2)
Ethnobotany Research & Applications : a journal of plants, people and applied research     Open Access   (Followers: 7)
Ethology     Hybrid Journal   (Followers: 6)
Ethology Ecology & Evolution     Hybrid Journal   (Followers: 12)
Eukaryotic Cell     Full-text available via subscription   (Followers: 6)
EuPA Open Proteomics     Open Access   (Followers: 2)
EURASIP Journal on Bioinformatics and Systems Biology     Open Access   (Followers: 6)
European Journal of Cell Biology     Hybrid Journal   (Followers: 3)
European Journal of Neuroscience     Hybrid Journal   (Followers: 27)
European Journal of Phycology     Hybrid Journal   (Followers: 5)
European Journal of Protistology     Hybrid Journal   (Followers: 3)
European Journal of Soil Biology     Hybrid Journal   (Followers: 2)
European Online Journal of Natural and Social Sciences     Open Access   (Followers: 13)
European Scientific Journal     Open Access   (Followers: 2)
Evidência - Ciência e Biotecnologia - Interdisciplinar     Open Access  
EvoDevo     Open Access   (Followers: 1)
Evolução e Conservação da Biodiversidade     Open Access  
Evolution     Partially Free   (Followers: 67)
Evolution and Human Behavior     Hybrid Journal   (Followers: 11)
Evolutionary Applications     Open Access   (Followers: 3)
Evolutionary Bioinformatics     Open Access   (Followers: 15)
Evolutionary Biology     Hybrid Journal   (Followers: 18)
Evolutionary Computation     Hybrid Journal   (Followers: 9)
Experimental & Molecular Medicine     Open Access   (Followers: 2)
Experimental and Applied Acarology     Hybrid Journal   (Followers: 1)
Experimental Cell Research     Hybrid Journal   (Followers: 3)
Expert Opinion on Biological Therapy     Hybrid Journal   (Followers: 10)
Expert Opinion on Environmental Biology     Hybrid Journal  
Expert Review of Proteomics     Hybrid Journal   (Followers: 2)
Extreme Life, Biospeology & Astrobiology - International Journal of the Bioflux Society     Full-text available via subscription   (Followers: 5)
Extremophiles     Hybrid Journal   (Followers: 1)
F1000Research     Open Access   (Followers: 3)
Facta Universitatis, Series : Medicine and Biology     Open Access  
Familial Cancer     Hybrid Journal   (Followers: 1)
Fatigue & Fracture of Engineering Materials and Structures     Hybrid Journal   (Followers: 14)
Fauna Norvegica     Open Access  
Febs Journal     Hybrid Journal   (Followers: 8)
Feddes Repertorium     Hybrid Journal  
Fems Yeast Research     Hybrid Journal   (Followers: 11)
Field Mycology     Full-text available via subscription   (Followers: 1)
Fish & Shellfish Immunology     Hybrid Journal   (Followers: 10)
Fitoterapia     Hybrid Journal   (Followers: 4)
Fly     Full-text available via subscription  
Folia Biologica     Free  
Folia Biologica et Oecologica     Open Access   (Followers: 1)

  First | 1 2 3 4 5 6 7 8 | Last

Journal Cover   Anaerobe
  [SJR: 1.09]   [H-I: 44]   [3 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1075-9964 - ISSN (Online) 1095-8274
   Published by Elsevier Homepage  [2811 journals]
  • Bacteremic Meningitis Caused by Parvimonas micra in an Immunocompetent
           Host
    • Abstract: Publication date: Available online 11 May 2015
      Source:Anaerobe
      Author(s): Jae-Hoon Ko , Jin Yang Baek , Cheol-In Kang , Woo Joo Lee , Ji Yong Lee , Sun Young Cho , Young Eun Ha , So Hyun Kim , Doo Ryeon Chung , Kyong Ran Peck , Nam Yong Lee , Jae-Hoon Song
      A 61-year-old man with chronic hepatitis B and dyslipidemia visited the emergency department with a fever and severe headache. He was diagnosed with bacterial meningitis after a lumbar puncture, and blood culture revealed Parvimonas micra bacteremia. Although he had a history of extraction of a molar two weeks before symptom onset, there was no evidence of abscess formation on physical examination or imaging studies. He was successfully treated with oral metronidazole for 12 days after 9 days of treatment with IV ceftriaxone and vancomcycin. This is the first report of primary bacterial meningitis caused by this organism, which indicates that this organism is capable of being a bacterial meningitis pathogen.


      PubDate: 2015-05-20T01:33:39Z
       
  • Aciduric microbial taxa including Scardovia wiggsiae and Bifidobacterium
           spp. in caries and caries free subjects
    • Abstract: Publication date: Available online 28 April 2015
      Source:Anaerobe
      Author(s): Karsten Henne , Anke Rheinberg , Beate Melzer-Krick , Georg Conrads
      Actinobacteria came into focus of being potential caries-associated pathogens and could, together with the established Streptococcus mutans and lactobacilli thus function as caries indicator species. Here we analyzed the role and diagnostic predictive value of the acidogenic-aciduric species Scardovia wiggsiae and Bifidobacterium dentium together with S. mutans, lactobacilli and bifidobacteria in biofilm of non-cavitated (n=20) and cavitated (n=6) caries lesions versus controls (n=30). For the genus Bifidobacterium and for B. dentium new sets of primers were designed. Based on real-time quantitative PCR and confirmed by DNA sequencing we found a higher prevalence (61.5%) of S. wiggsiae in caries lesions than in controls (40%). However, among the controls we found three individuals with both the highest absolute and relative S. wiggsiae numbers. Testing for S. mutans revealed the same prevalence as S. wiggsiae in caries lesions (61.5%) but in controls its prevalence was only 10%. B. dentium was never found in healthy plaque but in 30.8% of clinical cases, with the highest numbers in cavitated lesions. The Bifidobacterium-genus specific PCR had less discriminative power as more control samples were positive. We calculated the relative abundances and applied receiver operating characteristic analyses. The top results of specificity (93% and 87%) and sensitivity (100% and 88%) were found when the constraint set was “Lactobacillus relative abundance ≥0.02%” and “two aciduric species with a relative abundance of each ≥ 0.007%”. Combinatory measurement of several aciduric taxa may be useful to reveal caries activity or even to predict caries progression.


      PubDate: 2015-05-20T01:33:39Z
       
  • Leukemoid reaction to Clostridium difficile infection
    • Abstract: Publication date: Available online 13 May 2015
      Source:Anaerobe
      Author(s): Ashutossh Naaraayan , Melissa Aleta , Prasanta Basak , Stephen Jesmajian , Robert Goldstein
      Clostridium difficile infections (CDI) are increasing in incidence and severity. Leukemoid reaction is rarely seen with CDI, and indicates severe disease with grave prognosis. We present an elderly female who developed leukemoid reaction in response to CDI. The patient died despite early antibiotic therapy with surgical evaluation.


      PubDate: 2015-05-20T01:33:39Z
       
  • Fusobacterium necrophorum and other Fusobacterium spp. isolated from head
           and neck infections: a 10- year epidemiology study in an academic hospital
           
    • Abstract: Publication date: Available online 16 May 2015
      Source:Anaerobe
      Author(s): Erlangga Yusuf , Stijn Halewyck , Ingrid Wybo , Denis Piérard , Frans Gordts
      Background Fusobacterium spp. from clinical specimens are increasingly reported. We sought to describe the epidemiology, the microbiological, and the clinical characteristics of head and neck infections caused by F. necrophorum and other Fusobacterium spp. Materials and methods Retrospective cohort study between October 1st, 2004 and September 30th, 2014 performed in an academic hospital. Electronic patient charts and the laboratory information system were reviewed for demographic and microbiological data. The number and percentages of specific diagnosis and treatment among patients with positive Fusobacterium spp. culture were calculated. The incidence was calculated based on the number of specimens investigated each year. Results Included were 230 cultures of 230 patients (median age of 28 years, 61.7 % men). F. necrophorum were often found in young patients with high C-reactive protein (CRP) and high number of leukocytes in blood. Other Fusobacterium spp. were often found in middle aged patients with relatively high CRP and slightly increased leukocytes. Three major causes of the isolation of F. necrophorum and other Fusobacterium spp.. were acute tonsillitis (n=18, incidence of 0.2%), peritonsillar abscess (n=39, 0.5%) and acute otitis (n=45, 0.1%). While F. necrophorum were found in majority (37/57) of patients with acute tonsillitis or peritonsillar abscess, Fusobacterium spp. other than F. necrophorum were found in the majority (35/45) of patients with acute otitis. Isolated fusobacteria were susceptible to beta-lactam antibiotics, clindamycin and metronidazole. The outcomes of patients with Fusobacterium spp. were good. Conclusion F. necrophorum and other Fusobacterium spp. are rare cause of head and neck infections. The infections are well treated by combination of antibiotics and surgery.


      PubDate: 2015-05-20T01:33:39Z
       
  • Isolation and identification of cultivable Bifidobacterium spp. from the
           faeces of 5 baby common marmosets (Callithrix jacchus L.)
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Samanta Michelini , Monica Modesto , Kaihei Oki , Verena Stenico , Ilaria Stefanini , Bruno Biavati , Koichi Watanabe , Alessia Ferrara , Paola Mattarelli
      Ninety-two bifidobacterial strains were obtained from the faeces of 5 baby common marmosets, three known species Bifidobacterium aesculapii, Bifidobacterium callithricos and Bifidobacterium reuteri and 4 novel putative bifidobacterial species were retrieved. The occurrence of bifidobacteria in non-human primate babies is described for the first time.


      PubDate: 2015-05-20T01:33:39Z
       
  • Oral microbiota change, tooth decay and hemorrhoidal disease
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Bugra Ozkan , Sinem N. Topuk , Nesibe Taser , Levent Filik



      PubDate: 2015-05-20T01:33:39Z
       
  • Occurrence and New Mutations Involved in Rifampicin-Resistant
           Propionibacterium acnes Strains Isolated from Biofilm or Device-Related
           Infections
    • Abstract: Publication date: Available online 18 May 2015
      Source:Anaerobe
      Author(s): Ulrika Furustrand Tafin , Guillaume Ghislain Aubin , Geri Eich , Andrej Trampuz , Stéphane Corvec
      We described for the first time the amino acid substitutions conferring rifampicin resistance in eight Propionibacterium acnes strains isolated from patients with biofilm or device-related infections. We identified different mutations in cluster I and one mutation, never reported, in cluster II of the rpoB gene (I480V) associated with the most frequent one in cluster I (S442L). Half of the patients previously received treatment with rifampicin.


      PubDate: 2015-05-20T01:33:39Z
       
  • Acute graft-versus-host disease, invasive aspergillosis and Clostridium
           difficile colitis after peripheral blood stem cell transplantation: A
           complex network of causalities and a challenge for prevention
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Nagham Khanafer , Antoine Neuraz , Thomas Bénet , Martin Cour , Florence Persat , Hélène Labussière , Laurent Argaud , Mauricette Michallet , Philippe Vanhems
      Graft-versus-host disease (GVHD) is a known risk factor for invasive aspergillosis (IA), but remains poorly studied in relation to Clostridium difficile infection (CDI). We report a case of a 58-years-old patient who developed an IA within a protected room, CDI and GVHD after allogeneic allogeneic peripheral blood stem cell transplantation (PBSCT). Factors associated with this complex condition in patients receiving allogeneic PBSCT need to be identified.


      PubDate: 2015-05-20T01:33:39Z
       
  • Changes in lipopolysaccharide profile of Porphyromonas gingivalis clinical
           isolates correlate with changes in colony morphology and polymyxin B
           resistance
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Leonor Díaz , Anilei Hoare , Cristopher Soto , Isaac Bugueño , Nora Silva , Nicolás Dutzan , Darna Venegas , Daniela Salinas , José Manuel Pérez-Donoso , Jorge Gamonal , Denisse Bravo
      Virulence factors on the surface of Porphyromonas gingivalis constitute the first line of interaction with host cells and contribute to immune modulation and periodontitis progression. In order to characterize surface virulence factors present on P. gingivalis, we obtained clinical isolates from healthy and periodontitis subjects and compared them with reference strains. Colony morphology, aggregation in liquid medium, surface charge, membrane permeability to bactericidal compounds, novobiocin and polymyxin B resistance, capsule presence and lipopolysaccharide (LPS) profiles were evaluated. By comparing isolates from healthy and periodontitis subjects, differences in colony morphology and aggregation in liquid culture were found; the latter being similar to two reference strains. These differences were not a consequence of variations in bacterial surface charge. Furthermore, isolates also presented differences in polymyxin B and novobiocin resistance; isolates from healthy subjects were susceptible to polymyxin B and resistant to novobiocin and, in contrast, isolates from periodontitis subjects were resistant to polymyxin B and susceptible to novobiocin. These changes in antimicrobial resistance levels correlate with variations in LPS profiles, since -unlike periodontitis isolates–isolates from healthy samples synthesize LPS molecules lacking both O-antigen moieties and anionic polysaccharide. Additionally, this phenotype correlated with the absence of O-antigen ligase activity. Altogether, our results reveal novel variations on surface components of P. gingivalis isolates obtained from healthy and periodontitis subjects that could be associated with differences in bacterial virulence and periodontitis progression.
      Graphical abstract image

      PubDate: 2015-05-20T01:33:39Z
       
  • Identification, purification and characterization of furfural transforming
           enzymes from Clostridium beijerinckii NCIMB 8052
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Yan Zhang , Victor Ujor , Macdonald Wick , Thaddeus Chukwuemeka Ezeji
      Generation of microbial inhibitory compounds such as furfural and 5-hydroxymethylfurfural (HMF) is a formidable roadblock to fermentation of lignocellulose-derived sugars to butanol. Bioabatement offers a cost effective strategy to circumvent this challenge. Although Clostridium beijerinckii NCIMB 8052 can transform 2–3 g/L of furfural and HMF to their less toxic alcohols, higher concentrations present in biomass hydrolysates are intractable to microbial transformation. To delineate the mechanism by which C. beijerinckii detoxifies furfural and HMF, an aldo/keto reductase (AKR) and a short-chain dehydrogenase/reductase (SDR) found to be over-expressed in furfural-challenged cultures of C. beijerinckii were cloned and over-expressed in Escherichia coli Rosetta-gami™ B(DE3)pLysS, and purified by histidine tag-assisted immobilized metal affinity chromatography. Protein gel analysis showed that the molecular weights of purified AKR and SDR are close to the predicted values of 37 kDa and 27 kDa, respectively. While AKR has apparent Km and Vmax values of 32.4 mM and 254.2 mM s−1 respectively, using furfural as substrate, SDR showed lower Km (26.4 mM) and Vmax (22.6 mM s−1) values on the same substrate. However, AKR showed 7.1-fold higher specific activity on furfural than SDR. Further, both AKR and SDR were found to be active on HMF, benzaldehyde, and butyraldehyde. Both enzymes require NADPH as a cofactor for aldehydes reduction. Based on these results, it is proposed that AKR and SDR are involved in the biotransformation of furfural and HMF by C. beijerinckii.


      PubDate: 2015-05-20T01:33:39Z
       
  • Development of a PCR assay based on the 16S–23S rDNA internal
           transcribed spacer for identification of strictly anaerobic bacterium
           Zymophilus
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Jurgen Felsberg , Markéta Jelínková , Petra Kubizniaková , Dagmar Matoulková
      PCR-primers were designed for identification of strictly anaerobic bacteria of the genus Zymophilus based on genus-specific sequences of the 16S–23S rDNA internal transcribed spacer region. The specificity of the primers was tested against 37 brewery-related non-target microorganisms that could potentially occur in the same brewery specimens. None DNA was amplified from any of the non-Zymophilus strains tested including genera from the same family (Pectinatus, Megasphaera, Selenomonas), showing thus 100% specificity. PCR assay developed in this study allows an extension of the spectra of detected beer spoilage microorganisms in brewery laboratories.


      PubDate: 2015-05-20T01:33:39Z
       
  • In vitro modulation of tumor necrosis factor α production in
           THP-1 cells by lactic acid bacteria isolated from healthy human infants
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Boonyarut Ladda , Talent Theparee , Juntana Chimchang , Somboon Tanasupawat , Malai Taweechotipatr
      The human microbiota is a source of probiotics capable of modulating the host immune system. In this study, we collected fecal samples from 100 healthy infants and isolated lactic acid bacteria which were screened for immune modulating effects on tumor necrosis factor α (TNF-α) production. Cell-free culture supernatants from 26 isolates were able to decrease TNF-α production in vitro and three of the isolates were selected as candidate probiotics (MSMC39-1, MSMC39-3, MSMC57-1). These isolates were identified using 16S ribosomal DNA sequencing as Lactobacillus paracasei, Lactobacillus casei, and Weissella confusa respectively. All three isolates were acid tolerant and bile tolerant to pH 3.0 and 4% bile respectively. Preparations of cell-free culture supernatants were processed and tested, and revealed that cell-free culture supernatants of isolates L. paracasei MSMC39-1, L. casei MSMC39-3, and W. confusa MSMC57-1 decreased the production of TNF-α significantly and were heat resistant. Only L. paracasei MSMC39-1 supernatant was proteinase-K sensitive. The effects of viable bacteria, heat-killed bacteria, and sonicated bacteria were compared. The heat-killed preparations of isolate W. confusa MSMC57-1 decreased the production of TNF-α. Sonicated cell preparations did not significantly alter TNF-α production. For isolates L. paracasei MSMC39-1 and L. casei MSMC39-3, this suggests that a substance in the cell-free culture supernatant may be responsible for in vitro cytokine modulation.


      PubDate: 2015-05-20T01:33:39Z
       
  • Differences in acid tolerance between Bifidobacterium breve BB8 and its
           acid-resistant derivative B. breve BB8dpH, revealed by RNA-sequencing
           and physiological analysis
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Xu Yang , Xiaomin Hang , Jing Tan , Hong Yang
      Bifidobacteria are common inhabitants of the human gastrointestinal tract, and their application has increased dramatically in recent years due to their health-promoting effects. The ability of bifidobacteria to tolerate acidic environments is particularly important for their function as probiotics because they encounter such environments in food products and during passage through the gastrointestinal tract. In this study, we generated a derivative, Bifidobacterium breve BB8dpH, which displayed a stable, acid-resistant phenotype. To investigate the possible reasons for the higher acid tolerance of B. breve BB8dpH, as compared with its parental strain B. breve BB8, a combined transcriptome and physiological approach was used to characterize differences between the two strains. An analysis of the transcriptome by RNA-sequencing indicated that the expression of 121 genes was increased by more than 2-fold, while the expression of 146 genes was reduced more than 2-fold, in B. breve BB8dpH. Validation of the RNA-sequencing data using real-time quantitative PCR analysis demonstrated that the RNA-sequencing results were highly reliable. The comparison analysis, based on differentially expressed genes, suggested that the acid tolerance of B. breve BB8dpH was enhanced by regulating the expression of genes involved in carbohydrate transport and metabolism, energy production, synthesis of cell envelope components (peptidoglycan and exopolysaccharide), synthesis and transport of glutamate and glutamine, and histidine synthesis. Furthermore, an analysis of physiological data showed that B. breve BB8dpH displayed higher production of exopolysaccharide and lower H+-ATPase activity than B. breve BB8. The results presented here will improve our understanding of acid tolerance in bifidobacteria, and they will lead to the development of new strategies to enhance the acid tolerance of bifidobacterial strains.


      PubDate: 2015-05-20T01:33:39Z
       
  • Morphological and genetic characterization of group I Clostridium
           botulinum type B strain 111 and the transcriptional regulator spoIIID gene
           knockout mutant in sporulation
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Koji Hosomi , Ritsuko Kuwana , Hiromu Takamatsu , Tomoko Kohda , Shunji Kozaki , Masafumi Mukamoto
      Clostridium botulinum is a heat-resistant spore-forming bacterium that causes the serious paralytic illness botulism. Heat-resistant spores may cause food sanitation hazards and sporulation plays a central role in the survival of C. botulinum. We observed morphological changes and investigated the role of the transcriptional regulator SpoIIID in the sporulation of C. botulinum type B strain 111 in order to elucidate the molecular mechanism in C. botulinum. C. botulinum type B formed heat-resistant spores through successive morphological changes corresponding to those of Bacillus subtilis, a spore-forming model organism. An analysis of the spoIIID gene knockout mutant revealed that the transcriptional regulator SpoIIID contributed to heat-resistant spore formation by C. botulinum type B and activated the transcription of the sigK gene later during sporulation. Transcription of the spoIIID gene, which differed from that in B. subtilis and Clostridium difficile, was observed in the sigE gene knockout mutant of C. botulinum type B. An analysis of the sigF gene knockout mutant showed that the sporulation-specific sigma factor SigF was essential for transcription of the spoIIID gene in C. botulinum type B. These results suggest that the regulation of sporulation in C. botulinum is not similar to that in B. subtilis and other clostridia.


      PubDate: 2015-05-20T01:33:39Z
       
  • High-throughput 16S rRNA gene sequencing reveals alterations of mouse
           intestinal microbiota after radiotherapy
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Young Suk Kim , Jinu Kim , Soo-Je Park
      The mammalian gastrointestinal tract harbors a highly complex microbial community that comprises hundreds of different types of bacterial cells. The gastrointestinal microbiota plays an important role in the function of the host intestine. Most cancer patients undergoing pelvic irradiation experience side effects such as diarrhea; however, little is currently known about the effects of irradiation on the microorganisms colonizing the mucosal surfaces of the gastrointestinal tract. The aim of this study was to investigate the effects of gamma irradiation on the compositions of the large and small intestinal microbiotas. The gut microbiotas in control mice and mice receiving irradiation treatment were characterized by high-throughput sequencing of the bacterial 16S rRNA gene. Irradiation treatment induced significant alterations in the bacterial compositions of the large and small intestines at the genus level. Unexpectedly, irradiation treatment increased the number of operational taxonomic units in the small intestine but not the large intestine. In particular, irradiation treatment increased the level of the genera Alistipes in the large intestine and increased the level of the genus Corynebacterium in the small intestine. By contrast, compared with that in the corresponding control group, the level of the genera Prevotella was lower in the irradiated large intestine, and the level of the genera Alistipes was lower in the irradiated small intestine. Overall, the data presented here reveal the potential microbiological effects of pelvic irradiation on the gastrointestinal tracts of cancer patients.


      PubDate: 2015-05-20T01:33:39Z
       
  • High rate of non-susceptibility to metronidazole and clindamycin
           in anaerobic isolates: Data from a clinical laboratory from Karachi,
           Pakistan
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Sadia Omer Sheikh , Kauser Jabeen , Saba Qaiser , Syed Tanwir Ahsan , Erum Khan , Afia Zafar
      Due to increasing resistance amongst anaerobic pathogens periodic surveillance of resistance has been recommended in regional/local settings. Anaerobic antimicrobial susceptibility testing is not routinely performed in many laboratories in Pakistan, hence absence of local data may lead to inappropriate empirical therapy in serious cases. 121 clinically significant anaerobic strains (26/121; 21% bacteremic isolates) were isolated and saved from 2010 to 2011. Susceptibility testing against metronidazole, clindamycin, co-amoxiclav, meropenem, piperacillin/tazobactam, linezolid and gatifloxacin was performed by determining minimum inhibitory concentrations (MICs). A high proportion of non-susceptible strains to metronidazole (10% of 121 isolates) and clindamycin (12% of 121 isolates) was seen, most noticeable in Bacteroides fragilis. Three Bacteroides species strains were non-susceptible to both metronidazole and clindamycin. One strain of Clostridium species was fully resistant to metronidazole and had intermediate resistance to clindamycin. No resistance to any of the other tested antibiotics was seen. Resistance to metronidazole was higher in bacteremic vs. non bacteremic isolates (p = value 0.07). In our setting where there is a high usage of empirical metronidazole and clindamycin for the treatment of serious anaerobic infections clinicians should be aware of increased resistance to these agents. Periodic surveillance of resistance to anti-anaerobic drugs especially metronidazole and clindamycin should be performed to generate antibiogram and guide appropriate empiric therapy.


      PubDate: 2015-05-20T01:33:39Z
       
  • Characterization of Lactobacillus isolated from dairy samples for
           probiotic properties
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Ashwani Kumar , Dinesh Kumar
      In the present study twelve Lactobacillus isolates (LBS 1-LBS 12) were characterized for probiotic properties. Out of the twelve, eight isolates (LBS 1–6, 8 and 11) were bile resistant (survival > 50% at 0.3% bile salt w/v) and five isolates (LBS 1, 2, 5, 6 and 11) were found acid pH value resistant (survival > 50% at pH 3). All twelve isolates inhibited the growth of Staphylococcus aureus whereas isolate LBS 2 also inhibited the growth of Escherichia coli and Salmonella typhimurium. Antibiotic susceptibility testing of isolates was also performed and isolate LBS 2 was selected for further study based on its broad spectrum effect in clinical pathogen inhibition. LBS 2 was characterized phenotypically at Institute of Microbial Technology (IMTECH), Chandigarh, India and was confirmed as Lactobacillus rhamnosus by 16S rDNA sequencing and subsequent analysis using BLAST. The gene sequence was deposited in GenBank with accession number KJ562858. Scanning electron microscopy (SEM) study was used to study in vitro epithelial cell adherence and bile salt effect on isolate LBS 2. Epithelial cells adherence assay showed positive results and surface roughness of LBS 2 increased with increase in bile salt (0.15–0.45% w/v).


      PubDate: 2015-05-20T01:33:39Z
       
  • Comparison of Clostridium difficile isolates from individuals with
           recurrent and single episode of infection
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Connor Richardson , Peter Kim , Christine Lee , Alexa Bersenas , J. Scott Weese
      Purpose Recurrent Clostridium difficile infection (CDI) is an increasing problem, yet reasons for this are poorly understood. Attention has been paid to the role of strain, with conflicting association of ribotype 027 and recurrences. Methods Stool samples and medical records data were collected from 60 patients: 27 with recurrent CDI and 33 with single episode CDI. C. difficile was isolated and ribotyped, and minimum inhibitory concentrations of metronidazole and vancomycin were determined by Etest. Results Twenty-seven ribotypes were identified, but only four (027, 014 and two internally designated strains) were found in more than one patient. Ribotype 027 predominated and was significantly over-represented in the recurrent CDI group (70%) versus the single episode CDI group (30%) (P = 0.004). Female gender and the presence of ribotype 027 were significantly associated with recurrent CDI in the multivariable model. Metronidazole MICs for recurrent isolates were significantly higher compared to single episode isolates (P ≤ 0.024). A general linear model indicated that the difference in MIC was associated with ribotype 027 (P = 0.0023), not whether the isolate was from recurrent or single episode disease (P = 0.25). Conclusions Ribotype 027 was associated with recurrent disease. While there was no difference in the prevalence of metronidazole resistance, isolates from recurrent CDI patients had significantly higher metronidazole MICs, because of higher MICs in ribotype 027. This study provides further support to the clinical importance of ribotype 027 and raises questions about the potential impact of decreased metronidazole susceptibility on the pathophysiology of recurrent CDI.


      PubDate: 2015-05-20T01:33:39Z
       
  • Anaerococcus degenerii sp. nov., isolated from human clinical specimens
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): A.C.M. Veloo , P.E. Elgersma , A.J. van Winkelhoff
      Four clinical isolates of gram-positive strict anaerobic cocci were isolated from four different human mixed anaerobic infections. The taxonomical status of the four strains could not be established using standard identification techniques. The biochemical features of the strains were established and their taxonomic position was determined using 16S rRNA sequencing. The four strains form a homogeneous phenotypical and genotypical cluster. A new Anaerococcus species is proposed for these isolates: Anaerococcus degenerii sp. nov. The type strain is UMCG-104T = DSM29674T (accession number AM176528).


      PubDate: 2015-05-20T01:33:39Z
       
  • Interactions of Salmonella enterica subspecies enterica serovar
           Typhimurium with gut bacteria
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Gaspar Avendaño-Pérez , Carmen Nueno-Palop , Arjan Narbad , Susan M. George , József Baranyi , Carmen Pin
      The aim of this study was to evaluate the impact of the gut microbiota on the growth and survival of S. Typhimurium. This was tested in two-species co-cultures and in mixed cultures with a simplified gut model microbiota. Subsequently, interactions between S. Typhimurium and human faecal bacteria were quantified in both batch and continuous culture systems simulating the human colon. The exponential growth of S. Typhimurium was halted when the population of Escherichia coli reached the maximum population density in a two-compartment co-culture system where the two species were separated by a 0.45 μm pore membrane. Furthermore, the growth of some gut bacteria such as Lactobacillus gasseri and Bifidobacterium bifidum was inhibited by the presence of S. Typhimurium in the other compartment. The survival of S. Typhimurium was severely affected in mixed batch cultures with human faecal samples; a reduction of 103–104 cfu/ml in the concentration of S. Typhimurium was observed in these cultures. However, no effect on S. Typhimurium survival was observed in mixed batch cultures with a simplified gut model microbiota under the same conditions. The effect of human faecal samples on S. Typhimurium in a three-stage continuous culture was different to that obtained in batch cultures; its growth rather than survival was affected under these conditions. S. Typhimurium growth was inhibited, and the bacterium was therefore eliminated by the continuous flow of the medium. Depending upon culturing conditions, the gut microbiota caused either growth inhibition, inactivation or did not affect S. Typhimurium.


      PubDate: 2015-05-20T01:33:39Z
       
  • Variation in germination of Clostridium difficile clinical isolates
           correlates to disease severity
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Paul E. Carlson Jr. , Alyssa M. Kaiser , Sarah A. McColm , Jessica M. Bauer , Vincent B. Young , David M. Aronoff , Philip C. Hanna
      Over the past two decades, Clostridium difficile infections have been increasing in both number and severity throughout the world. As with other spore forming bacteria, germination is a vital step in the life cycle of this pathogen. Studies have examined differences in sporulation and toxin production among a number of C. difficile clinical isolates; however, few have examined differences in germination and the relationship between this phenotype and disease severity. Here, over 100 C. difficile isolates from the University of Michigan Health System were examined for overall germination in response to various combinations of known germinants (taurocholate) and co-germinants (glycine and histidine). Significant variation was observed among isolates under all conditions tested. Isolates representing ribotype 014-020, which was the most frequently isolated ribotype at our hospital, exhibited increased germination in the presence of taurocholate and glycine when compared to isolates representing other ribotypes. Interestingly, isolates that caused severe disease exhibited significantly lower germination in response to minimal germination conditions (taurocholate only), indicating increased control over germination in these isolates. These data provide a broad picture of C. difficile isolate germination and indicate a role for precise control of germination in disease severity.


      PubDate: 2015-05-20T01:33:39Z
       
  • Development of a recombinant flagellin based ELISA for the detection of
           Clostridium chauvoei
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): J. Usharani , Viswas Konasagara Nagaleekar , Prasad Thomas , Santosh K. Gupta , Sanjeev K. Bhure , Premanshu Dandapat , Rajesh K. Agarwal , Vijendra P. Singh
      Blackleg, an economically important and highly fatal disease of ruminants, is caused by anaerobic bacillus, Clostridium chauvoei. Identification and differentiation of the causative agent is crucial for implementation of therapeutic and control measures in real time. Most of the diagnostic tests available for blackleg are PCR based, and only a couple of serological tests have been reported. In this study, we targeted flagellin, an important immunogenic protein of C. chauvoei, to develop a sandwich ELISA for detection of C. chauvoei. Sequence analysis of flagellin gene of related Clostridium species showed that central region of flagellin gene is unique to C. chauvoei. Hence, we cloned and expressed central region of flagellin in a prokaryotic expression system. Antiserum against recombinant flagellin was generated in rabbits and chickens. A sandwich ELISA was developed, in which rabbit anti-flagellin antibodies were used as capture antibodies and chicken anti-flagellin antibodies as detecting antibodies. The test was specific and sensitive in detection of up to 104 CFU/ml of C. chauvoei. This study shows that assay developed can be used for detection of C. chauvoei in suspected samples.


      PubDate: 2015-05-20T01:33:39Z
       
  • Prevalence and risk factors associated with Clostridium difficile shedding
           in veal calves in Italy
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Chiara Francesca Magistrali , Carmen Maresca , Lucilla Cucco , Luca Bano , Ilenia Drigo , Giovanni Filippini , Annalisa Dettori , Sayra Broccatelli , Giovanni Pezzotti
      The aim of this study is to describe the prevalence and risk factors of Clostridium difficile shedding in six farms belonging to two companies in Northern Italy. Four hundred and twenty veal calves, randomly selected and individually identified, were sampled three times: at 0–16, 90–120, and 150 days after introduction. C. difficile was isolated at least once from 87 out of the 420 calves (20.7%). The prevalence of shedding was 20.24% at the first sampling and dropped to 0.72% at the second sampling. None of the samples obtained at 150 days tested positive. Sampling of cecal contents and carcass swabs at slaughter was stratified according to the herd of origin of the animals. C. difficile was never isolated at slaughter, excluding a prevalence higher than 3.5% on the basis of previous investigations. Therefore, in this work, the veal calf could not be confirmed as a potential source of C. difficile for the consumer. Eight different ribotypes (RT) have been described, but the vast majority of the isolates (87.8%) belonged to three ribotypes only: RT-078, RT-012 and RT-126, which are also among the most common of the ribotypes detected in humans in Europe. Most isolates, and all the RT-078 isolates, harbored genes coding for toxins A and B, the binary toxin, and showed a deletion in the gene encoding toxin C, suggesting that the veal calf was a reservoir for epidemic hyper-virulent strains. A correlation between age and shedding was found: the odds ratio (OR) ranged from 2.79 for 36–45 days of age to 4.57 for 13–28 days of age. The presence of diarrhea at first sampling was significantly associated with the recovery of C. difficile in feces (OR 3.26). A correlation was found between the administration of antimicrobials and shedding: an increased risk was shown when the number of antimicrobials used was higher than 4 (OR 4.02) or 5–6 (OR 5.83) or when polymyxin E or beta-lactams were administered.


      PubDate: 2015-05-20T01:33:39Z
       
  • Gut microbial and short-chain fatty acid profiles in adults with chronic
           constipation before and after treatment with lubiprostone
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Dae-Wook Kang , John K. DiBaise , Zehra Esra Ilhan , Michael D. Crowell , Jai Ram Rideout , J. Gregory Caporaso , Bruce E. Rittmann , Rosa Krajmalnik-Brown
      Identifying specific gut microorganisms associated with chronic constipation may be useful for diagnostic and therapeutic purposes. The objective of this study was to evaluate whether or not the gut microbial community of constipated subjects had specific microbial signatures and to assess the effects of lubiprostone treatment on the gut microbial community. Stool diaries, breath H2 and CH4 levels, and stool samples were collected from ten healthy subjects and nine patients meeting the Rome III criteria for chronic functional constipation. Constipated subjects received lubiprostone for four weeks, during which stool diaries were maintained. Stool samples were evaluated for gut microbial communities using pyrosequencing and quantitative real-time PCR (qPCR) targeting 16S-rRNA gene, along with concentrations of short-chain fatty acids (SCFAs) using high-performance liquid chromatography. Prior to treatment, gut microbial profiles were similar between constipated subjects and healthy subjects, while iso-butyrate levels were significantly higher in constipated subjects compared with healthy subjects. Despite increases in stool frequency and improvements in consistency after lubiprostone treatment, gut microbial profiles and community diversity after treatment showed no significant change compared to before treatment. While we did not observe a significant difference in either breath methane or archaeal abundance between the stool samples of healthy and constipated subjects, we confirmed a strong correlation between archaeal abundance measured by qPCR and the amount of methane gas exhaled in the fasting breath. Butyrate levels, however, were significantly higher in the stool samples of constipated subjects after lubiprostone treatment, suggesting that lubiprostone treatment had an effect on the net accumulation of SCFAs in the gut. In conclusion, lubiprostone treatment improved constipation symptoms and increased levels of butyrate without substantial modification of the gut microbial structure.


      PubDate: 2015-05-20T01:33:39Z
       
  • Clostridium perfringens: A review of enteric diseases in dogs, cats and
           wild animals
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Rodrigo Otávio Silveira Silva , Francisco Carlos Faria Lobato
      Clostridium perfringens is a gram-positive anaerobic bacillus that is commonly part of the microbiota of humans and animals. It is considered a common enteric pathogen, but the pathogenesis and the predisposing factors of the disease commonly differ between host species. Thus, specific research is necessary to understand the role of this pathogen, how to diagnose it, and which control measures are applicable. The aim of this paper is to review the current knowledge of C. perfringens infections in dogs, cats and wild animals.


      PubDate: 2015-05-20T01:33:39Z
       
  • Detection of integron-associated gene cassettes and other antimicrobial
           resistance genes in enterotoxigenic Bacteroides fragilis
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Anirban Sarkar , Gururaja P. Pazhani , Ramamurthy Dharanidharan , Amit Ghosh , Thandavarayan Ramamurthy
      Twenty seven Enterotoxigenic Bacteroides fragilis (ETBF) strains isolated from children in Kolkata, India, were tested for their antimicrobial resistance, presence of integrons and resistance encoding genes. Almost all the strains (>90%) were resistant to two or more antimicrobials. About 59–92% of the strains were resistant to ampicillin, amoxicillin, streptomycin, tetracycline, ciprofloxacin and norfloxacin. Most of these antimicrobial agents have been used in the treatment of diarrhea and other infectious diseases. In addition, about half a number of strains (48–55%) were resistant to clindamycin, cefotaxime, ceftazidime, ampicillin/sulbactam and trimethoprim/sulfamethoxazole. Moxifloxacin and metronidazole resistance ranged from 30 to 40%. All strains however, were found to be susceptible to chloramphenicol and imipenem. Class 1 integrase (intI1) was detected in seven and class 2 integrase (intI2) in one of the twenty seven ETBF strains. Resistance gene cassettes carried by these integrons had different alleles of dfr or aad genes. Beside these integron-borne genes, other genes encoding different antimicrobial resistance were also detected. Resistance genes such as cep(A) and tet(Q) were detected in most of the ETBF strains. To the best of our knowledge, this work constituted the first extensive report from India on the detection of integrons and antimicrobial resistance genes in ETBF.


      PubDate: 2015-05-20T01:33:39Z
       
  • Ezakiella peruensis gen. nov., sp. nov. isolated from human fecal sample
           from a coastal traditional community in Peru
    • Abstract: Publication date: April 2015
      Source:Anaerobe, Volume 32
      Author(s): Nisha B. Patel , Raul Y. Tito , Alexandra J. Obregón-Tito , Lindsey O'Neal , Omar Trujillo-Villaroel , Luis Marin-Reyes , Luzmila Troncoso-Corzo , Emilio Guija-Poma , Moriyuki Hamada , Yoshihito Uchino , Cecil M. Lewis Jr. , Paul A. Lawson
      A novel Gram-stain positive, non-motile, non-sporeforming coccus-shaped, obligately anaerobic bacterium was isolated from a fecal sample of an individual residing in a traditional Peruvian community. The organism was characterized using biochemical, chemotaxonomic and phylogenetic methods. Comparative 16S rRNA gene sequence analyses and phenotypic characteristics demonstrated that the organism was biochemically and phenotypically related, but distinct, from a group of organisms referred to as the Gram-stain positive anaerobic cocci (GPAC). The major cellular fatty acids of the novel isolate were determined to be C16:0 (18.3%), C18:1ω9c (39.8%), C18:2ω6,9c/C18:0 ANTE (13.2%). Fermentation end products from PYG are acetate and formate. Cell-wall peptidoglycan was found to be A4α (L-Lys-L-Ala-L-Glu) and the G + C content was determined to be 38.4 mol%. Based on the phenotypic, chemotaxonomic, and phylogenetic results, Ezakiella peruensis gen. nov., sp. nov., is now proposed. The type strain is M6.X2T (DSM 27367T = NBRC 109957 T = CCUG 64571T).


      PubDate: 2015-05-20T01:33:39Z
       
  • In-vitro activity of taurolidine on single species and a multispecies
           population associated with periodontitis
    • Abstract: Publication date: April 2015
      Source:Anaerobe, Volume 32
      Author(s): Lilly Zollinger , Simone Schnyder , Sandor Nietzsche , Anton Sculean , Sigrun Eick
      The antimicrobial activity of taurolidine was compared with minocycline against microbial species associated with periodontitis (four single strains and a 12-species mixture). Minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs), killing as well as activities on established and forming single-species biofilms and a 12-species biofilm were determined. The MICs of taurolidine against single species were always 0.31 mg/ml, the MBCs were 0.64 mg/ml. The used mixed microbiota was less sensitive to taurolidine, MIC and the MBC was 2.5 mg/ml. The strains and the mixture were completely killed by 2.5 mg/ml taurolidine, whereas 256 μg/ml minocycline reduced the bacterial counts of the mixture by 5 log10 colony forming units (cfu). Coating the surface with 10 mg/ml taurolidine or 256 μg/ml minocycline prevented completely biofilm formation of Porphyromonas gingivalis ATCC 33277 but not of Aggregatibacter actinomycetemcomitans Y4 and the mixture. On 4.5 d old biofilms, taurolidine acted concentration dependent with a reduction by 5 log10 cfu (P. gingivalis ATCC 33277) and 7 log10 cfu (A. actinomycetemcomitans Y4) when applying 10 mg/ml. Minocycline decreased the cfu counts by 1–2 log10 cfu independent of the used concentration. The reduction of the cfu counts in the 4.5 d old multi-species biofilms was about 3 log10 cfu after application of any minocycline concentration and after using 10 mg/ml taurolidine. Taurolidine is active against species associated with periodontitis, even within biofilms. Nevertheless a complete elimination of complex biofilms by taurolidine seems to be impossible and underlines the importance of a mechanical removal of biofilms prior to application of taurolidine.


      PubDate: 2015-05-20T01:33:39Z
       
  • Mageeibacillus indolicus gen. nov., sp. nov.: A novel bacterium isolated
           from the female genital tract
    • Abstract: Publication date: April 2015
      Source:Anaerobe, Volume 32
      Author(s): Michele N. Austin , Lorna K. Rabe , Sujatha Srinivasan , David N. Fredricks , Harold C. Wiesenfeld , Sharon L. Hillier
      Three isolates of a bacterium recovered from human endometrium using conventional culture methods were characterized biochemically and subjected to 16S rRNA gene sequencing and phylogenetic analysis. Isolates were non-motile, obligately anaerobic, non-spore forming, asaccharolytic, non-cellulolytic, indole positive, Gram positive rods. Cell wall fatty acid profiling revealed C14:0, C16:0, C18:2 ω6, 9c, C18:1 ω9c and C18:0 to be the major fatty acid composition. The DNA mol % G+C was determined to be 44.2%. 16S rRNA gene sequence analysis revealed only 91% sequence similarity with the closest cultivated bacterial isolate, Saccharofermentans acetigenes. Based on genotypic and phenotypic data, all three isolates are considered to be members of the same species and data suggest it represents a novel genus and species in the order Clostridiales with an association with Clostridium rRNA cluster III within the family Ruminococcaceae. We propose the name, Mageeibacillus indolicus gen. nov., sp. nov. The type strain is BAA-2120T and CCUG 59143T.


      PubDate: 2015-05-20T01:33:39Z
       
  • Editorial board
    • Abstract: Publication date: April 2015
      Source:Anaerobe, Volume 32




      PubDate: 2015-05-20T01:33:39Z
       
  • The occurrence of antibiotic resistance genes in drug resistant
           Bacteroides fragilis isolates from Groote Schuur Hospital, South Africa
    • Abstract: Publication date: April 2015
      Source:Anaerobe, Volume 32
      Author(s): Rosemary Meggersee , Valerie Abratt
      Bacteroides fragilis, an anaerobic gut commensal and opportunistic pathogen, is a leading cause of anaerobic abscesses and bacteraemias. Treatment of infections is complicated by the emergence of resistance to several of the antibiotics used in the clinical setting. Genetic analysis of 23 B. fragilis isolates found that none of the metronidazole resistant strains carried the nimA-J genes, and no cfxA or ermF genes were detected. All of the tetracycline resistant isolates contained the tetQ gene and were sensitive to tigecycline. The cfiA gene was found in 3 of the strains, one of which was imipenem resistant and contained an upstream IS4351 insertion sequence. Another resistant strain had a unique G to A substitution in the promoter region of the cfiA gene, while the third was imipenem sensitive. Thirty percent of the isolates contained at least one plasmid, however, tetQ gene was located on the chromosome and not on any of the plasmids.


      PubDate: 2015-05-20T01:33:39Z
       
  • Bacterial profiles and proteolytic activity in peri-implantitis versus
           healthy sites
    • Abstract: Publication date: Available online 11 April 2015
      Source:Anaerobe
      Author(s): J. Neilands , C. Wickström , B. Kinnby , J.R. Davies , J. Hall , B. Friberg , G. Svensäter
      Peri-implantitis is a biofilm-induced destructive inflammatory process that, over time, results in loss of supporting bone around an osseointegrated dental implant. Biofilms at peri-implantitis sites have been reported to be dominated by Gram-negative anaerobic rods with a proteolytic metabolism such as, Fusobacterium, Porphyromonas, Prevotella and Tannerella, as well as anaerobic Gram-positive cocci. In this study, we hypothesized that protease activity is instrumental in driving bone destruction and we therefore compared the microbial composition and level of protease activity in samples of peri-implant biofluid (PIBF) from 25 healthy subjects (H group) and 25 subjects with peri-implantitis (PI group). Microbial composition was investigated using culture techniques and protease activity was determined using a FITC-labelled casein substrate. The microbial composition was highly variable in subjects both in the H and PI groups but one prominent difference was the prevalence of Porphyromonas/Prevotella and anaerobic Gram positive cocci which was significantly higher in the PI than in the H group. A subgroup of subjects with peri-implantitis displayed a high level of protease activity in the PIBF compared to healthy subjects. However, this activity could not be related to the presence of specific bacterial species. We propose that a high level of protease activity may be a predictive factor for disease progression in peri-implantitis. Further longitudinal studies are however required to determine whether assessment of protease activity could serve as a useful method to identify patients at risk for progressive tissue destruction.


      PubDate: 2015-05-20T01:33:39Z
       
  • Quantitation of biofilm and planktonic life forms of coexisting
           periodontal species
    • Abstract: Publication date: Available online 26 April 2015
      Source:Anaerobe
      Author(s): Maribasappa Karched , Radhika G. Bhardwaj , Anandavalli Inbamani , Sirkka Asikainen
      Background Complexity of oral polymicrobial communities has prompted a need for developing in vitro models to study behavior of coexisting bacteria. Little knowledge is available of in vitro co-growth of several periodontitis-associated species without early colonizers of dental plaque. The aim was to determine temporal changes in the quantities of six periodontal species in an in vitro biofilm model in comparison with parallel planktonic cultures. Material and methods Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Parvimonas micra, Campylobacter rectus and Fusobacterium nucleatum were anaerobically grown as multispecies and monospecies biofilms and parallel planktonic cultures using cell culture plates and microfuge tubes, respectively. After incubating 2, 4, 6, 8 days, biofilms and planktonic cultures were harvested, DNA extracted and the target species quantified using qPCR with species-specific 16S rDNA primers. Biofilm growth as monocultures was visualized at day 2 and 8 with confocal microscopy and crystal violet staining. Results The six species were found throughout the test period in all culture conditions, except that P. gingivalis and F. nucleatum were not detected in multispecies planktonic cultures at day 8. In multispecies biofilm, P. gingivalis qPCR counts (cells/ml) increased (P<0.05) from day 2–8 and were then higher (P<0.05) than those of A. actinomycetemcomitans and C. rectus, whereas in monospecies biofilm, P. gingivalis counts were lower (P<0.05) than those of the other species, except A. actinomycetemcomitans. When multi- and monospecies biofilm cultures were compared, P. gingivalis counts were higher (P<0.05) but those of the other species, except P. intermedia, lower (P<0.05) in multispecies biofilm. Comparison between planktonic and biofilm cultures showed that A. actinomycetemcomitans, P. micra and C. rectus had higher (P<0.05) counts in planktonic cultures no matter whether grown in mono- or multispecies environment. Conclusions Six periodontal species were able to form multispecies biofilm up to 8 days in vitro without pioneer plaque bacteria. P. gingivalis seemed to prefer multispecies biofilm environment whereas P. micra and A. actinomycetemcomitans planktonic culture.


      PubDate: 2015-05-20T01:33:39Z
       
  • Synergistic inhibition of Clostridium difficile with nisin-lysozyme
           combination treatment
    • Abstract: Publication date: August 2015
      Source:Anaerobe, Volume 34
      Author(s): Changhoon Chai , Kyung-Soo Lee , Se-Wook Oh
      Clostridium difficile vegetative cells were not inhibited completely after a 120-min treatment with 40 nM nisin or 0.8 mM lysozyme. However, these cells were completely inhibited after only a 30-min incubation with both 20 nM nisin and 0.2 mM lysozyme.
      Graphical abstract image

      PubDate: 2015-05-20T01:33:39Z
       
  • Detection and genetic characterization of β-lactamases in Prevotella
           intermedia and Prevotella nigrescens isolated from oral cavity infections
           and peritonsillar abscesses
    • Abstract: Publication date: June 2015
      Source:Anaerobe, Volume 33
      Author(s): Liliana Fernández-Canigia , Daniela Cejas , Gabriel Gutkind , Marcela Radice
      A prospective analysis on β-lactam resistance mechanisms and β-lactamase prevalence was conducted on Prevotella intermedia and Prevotella nigrescens recovered from patients with chronic periodontitis and peritonsillar abscesses. Both phenotypic and genotypic methods were performed to characterize the β-lactamases, their coding genes and their genetic contexts. Overall, β-lactamase production was observed in 64% (16/25) P. intermedia and 23.8% (5/21) P. nigrescens (p < 0.01). Besides higher β-lactamase production rates were observed in P. intermedia (8/16) than in P. nigrescens (2/16) recovered from chronic periodontitis, almost all isolates from peritonsillar abscesses were producers (8/9 and 3/3, respectively). cfxA, but not cepA and cblA, was detected in those isolates, which were previously categorized as β-lactamase producers. CfxA producing isolates displayed higher β-lactam MICs than non-producers in both species. The most frequent allele was cfxA2, followed by cfxA3 and a new allelic variant named cfxA6. The analysis of the downstream flanking region in the three cfxA variants revealed the association with mobA of Tn4555, suggesting their localization in a mobilizable element. β-lactam resistance and cfxA carriage prevalence seems to be not only related to the bacterial species but also to the infection site.


      PubDate: 2015-05-20T01:33:39Z
       
  • Chemical communication in the gut: Effects of microbiota-generated
           metabolites on gastrointestinal bacterial pathogens
    • Abstract: Publication date: August 2015
      Source:Anaerobe, Volume 34
      Author(s): Stefanie L. Vogt , Jorge Peña-Díaz , B. Brett Finlay
      Gastrointestinal pathogens must overcome many obstacles in order to successfully colonize a host, not the least of which is the presence of the gut microbiota, the trillions of commensal microorganisms inhabiting mammals' digestive tracts, and their products. It is well established that a healthy gut microbiota provides its host with protection from numerous pathogens, including Salmonella species, Clostridium difficile, diarrheagenic Escherichia coli, and Vibrio cholerae. Conversely, pathogenic bacteria have evolved mechanisms to establish an infection and thrive in the face of fierce competition from the microbiota for space and nutrients. Here, we review the evidence that gut microbiota-generated metabolites play a key role in determining the outcome of infection by bacterial pathogens. By consuming and transforming dietary and host-produced metabolites, as well as secreting primary and secondary metabolites of their own, the microbiota define the chemical environment of the gut and often determine specific host responses. Although most gut microbiota-produced metabolites are currently uncharacterized, several well-studied molecules made or modified by the microbiota are known to affect the growth and virulence of pathogens, including short-chain fatty acids, succinate, mucin O-glycans, molecular hydrogen, secondary bile acids, and the AI-2 quorum sensing autoinducer. We also discuss challenges and possible approaches to further study of the chemical interplay between microbiota and gastrointestinal pathogens.


      PubDate: 2015-05-20T01:33:39Z
       
  • Mesophilic hydrogen production in acidogenic packed-bed reactors (APBR)
           using raw sugarcane vinasse as substrate: Influence of support materials
    • Abstract: Publication date: August 2015
      Source:Anaerobe, Volume 34
      Author(s): Antônio Djalma Nunes Ferraz Júnior , Claudia Etchebehere , Marcelo Zaiat
      Bio-hydrogen production from sugarcane vinasse in anaerobic up-flow packed-bed reactors (APBR) was evaluated. Four types of support materials, expanded clay (EC), charcoal (Ch), porous ceramic (PC), and low-density polyethylene (LDP) were tested as support for biomass attachment. APBR (working volume – 2.3 L) were operated in parallel at a hydraulic retention time of 24 h, an organic loading rate of 36.2 kg-COD m−3 d−1, at 25 °C. Maximum volumetric hydrogen production values of 509.5, 404, 81.4 and 10.3 mL-H2 d−1 L−1 reactor and maximum yields of 3.2, 2.6, 0.4 and 0.05 mol-H2 mol−1 carbohydrates total, were observed during the monitoring of the reactors filled with LDP, EC, Ch and PC, respectively. Thus, indicating the strong influence of the support material on H2 production. LDP was the most appropriate material for hydrogen production among the materials evaluated. 16S rRNA gene by Terminal Restriction Fragment Length Polymorphism (T-RFLP) analysis and scanning electron microscopy confirmed the selection of different microbial populations. 454-pyrosequencing performed on samples from APBR filled with LDP revealed the presence of hydrogen-producing organisms (Clostridium and Pectinatus), lactic acid bacteria and non-fermentative organisms.


      PubDate: 2015-05-20T01:33:39Z
       
  • Optimal spore germination in Clostridium botulinum ATCC 3502 requires the
           presence of functional copies of SleB and YpeB, but not CwlJ
    • Abstract: Publication date: August 2015
      Source:Anaerobe, Volume 34
      Author(s): Carolyn A. Meaney , Stephen T. Cartman , Peter J. McClure , Nigel P. Minton
      Germination, the process by which dormant endospores return to vegetative growth, is a critical process in the life cycle of the notorious pathogen Clostridium botulinum. Crucial is the degradation by hydrolytic enzymes of an inner peptidoglycan spore layer termed the cortex. Two mechanistically different systems of cortex lysis exist in spores of Clostridium species. C. botulinum ATCC 3502 harbours the Bacillus-like system of SleB, CwlJ and YpeB cortex lytic enzymes (CLEs). Through the construction of insertional gene knockout mutants in the sleB, cwlJ and ypeB genes of C. botulinum ATCC 3502 and the production of spores of each mutant strain, the effect on germination was assessed. This study demonstrates a reduced germination efficiency in spores carrying mutations in either sleB or ypeB with an approximate 2-fold reduction in heat resistant colony forming units (CFU/OD600) when plated on rich media. This reduction could be restored to wild-type levels by removing the spore coat and plating on media supplemented with lysozyme. It was observed that cwlJ spores displayed a similar germination efficiency as wild-type spores (P > 0.05). An optimal germinant commixture was identified to include a combination of l-alanine with sodium bicarbonate as it resulted in a 32% drop in OD600, while the additional incorporation of l-lactate resulted in a 57% decrease. Studies of the germination efficiency of spores prepared from all three CLE mutants was performed by monitoring the associated decrease in optical density but a germination defect was not observed in any of the CLE mutant strains. This was likely due to the lack of specificity of this particular assay. Taken together, these data indicate that functional copies of SleB and YpeB, but not CwlJ are required for the optimal germination of the spores of C. botulinum ATCC 3502.


      PubDate: 2015-05-20T01:33:39Z
       
  • Evaluation of composition and individual variability of rumen microbiota
           in yaks by 16S rRNA high-throughput sequencing technology
    • Abstract: Publication date: August 2015
      Source:Anaerobe, Volume 34
      Author(s): Wei Guo , Ying Li , Lizhi Wang , Jiwen Wang , Qin Xu , Tianhai Yan , Bai Xue
      The Yak (Bos grunniens) is a unique species of ruminant animals that is important to agriculture of the Tibetan plateau, and has a complex intestinal microbial community. The objective of the present study was to characterize the composition and individual variability of microbiota in the rumen of yaks using 16S rRNA gene high-throughput sequencing technique. Rumen samples used in the present study were obtained from grazing adult male yaks (n = 6) in a commercial farm in Ganzi Autonomous Prefecture of Sichuan Province, China. Universal prokaryote primers were used to target the V4–V5 hypervariable region of 16S rRNA gene. A total of 7200 operational taxonomic units (OTUs) were obtained after sequence filtering and chimera removal. Within these OTUs, 0.56% belonged to Archaea (40 OTUs), 7.19% to unassigned species (518 OTUs), and the remaining OTUs (6642) in all samples were of bacterial origin. When examining the community structure of bacteria, we identified 23 phyla within 159 families after taxonomic summarization. Bacteroidetes and Firmicutes were the predominant phyla accounting for 39.68% (SD = 0.05) and 45.90% (SD = 0.06), respectively. Moreover, 3764 OTUs were identified as shared OTUs (i.e. represented in all yaks) and belonged to 35 genera, exhibiting highly variable abundance across individual samples. Phylogenetic placement of these genera across individual samples was examined. In addition, we evaluated the distance among the 6 rumen samples by adding taxon phylogeny using UniFrac, representing 24.1% of average distance. In summary, the current study reveals a shared rumen microbiome and phylogenetic lineage and presents novel information on composition and individual variability of the bacterial community in the rumen of yaks.


      PubDate: 2015-05-20T01:33:39Z
       
  • In-vitro model for studying methanogens in human gut microbiota
    • Abstract: Publication date: August 2015
      Source:Anaerobe, Volume 34
      Author(s): William Tottey , Nadia Gaci , Guillaume Borrel , Monique Alric , Paul W. O'Toole , Jean-François Brugère
      Reported failures with gnotobiotic animal models led us to establish an in-vitro model of reciprocal conversion of methanogenic and non methanogenic microbiota from human fecal samples. Consequences on gas and microbiota compositions are reported. This should facilitate the study of the controversial role of gut methanogens in human health.
      Graphical abstract image

      PubDate: 2015-05-20T01:33:39Z
       
  • Development of a triplex real-time PCR assay for the simultaneous
           detection of Clostridium beijerinckii, Clostridium sporogenes and
           Clostridium tyrobutyricum in milk
    • Abstract: Publication date: August 2015
      Source:Anaerobe, Volume 34
      Author(s): Stefano Morandi , Paola Cremonesi , Tiziana Silvetti , Bianca Castiglioni , Milena Brasca
      Clostridium beijerinckii, Clostridium sporogenes and Clostridium tyrobutyricum are considered the leading bacteria implicated in late blowing defects affecting semi-hard and hard cheese production. The aim of this study was to develop a multiplex Real-Time PCR (qPCR) analysis for a rapid and simultaneous detection of C. beijerinckii, C. sporogenes and C. tyrobutyricum, using specific primers respectively targeting the nifH, gerAA and enr genes. The limits of detection in raw milk were 300 CFU/50 mL in the case of C. beijerinckii, 2 CFU/50 mL for C. sporogenes and 5 CFU/50 mL for C. tyrobutyricum spores. The qPCR method was applied to artificially contaminated raw milk samples, and molecular quantification showed good correlation (R2 = 0.978) with microbiological counting. Our results demonstrate that this method, combined with a DNA extraction protocol optimized for spore lysis, could be a useful tool for the direct quantification of the considered clostridia species.


      PubDate: 2015-05-20T01:33:39Z
       
  • Non-classical azoreductase secretion in Clostridium perfringens in
           response to sulfonated azo dye exposure
    • Abstract: Publication date: August 2015
      Source:Anaerobe, Volume 34
      Author(s): Jessica M. Morrison , Gilbert H. John
      Clostridium perfringens, a strictly anaerobic microorganism and inhabitant of the human intestine, has been shown to produce an azoreductase enzyme (AzoC), an NADH-dependent flavin oxidoreductase. This enzyme reduces azo dyes into aromatic amines, which can be carcinogenic. A significant amount of work has been completed on the activity of AzoC. Despite this, much is still unknown, including whether azoreduction of these dyes occurs intracellularly or extracellulary. A physiological study of C. perfringens involving the effect of azo dye exposure was completed to answer this question. Through exposure studies, azo dyes were found to cause cytoplasmic protein release, including AzoC, from C. perfringens in dividing and non-dividing cells. Sulfonation (negative charge) of azo dyes proved to be the key to facilitating protein release of AzoC and was found to be azo-dye-concentration-dependent. Additionally, AzoC was found to localize to the Gram-positive periplasmic region. Using a ΔazoC knockout mutant, the presence of additional azoreductases in C. perfringens was suggested. These results support the notion that the azoreduction of these dyes may occur extracellularly for the commensal C. perfringens in the intestine.


      PubDate: 2015-05-20T01:33:39Z
       
  • Microbiota and probiotics in canine and feline welfare
    • Abstract: Publication date: August 2015
      Source:Anaerobe, Volume 34
      Author(s): Łukasz Grześkowiak , Akihito Endo , Shea Beasley , Seppo Salminen
      Dogs and cats have been cohabiting with us for thousands of years. They are the major human companions. Today, dogs and cats live in urban areas. Cats and most dogs are on high carbohydrate diets and face similar life-style challenges as the human beings. The health and well-being of companion animals, just as their owners, depends on the gut microbes. Providing a proper care and nutritionally balanced diet to companion animals is recognised as a part of our responsibility to maintain the health and well being of our pet. However, as microbiota differences may facilitate exposure to pathogens and harmful environmental influences, it is prudent to search for novel tools to protect dogs and cats and at the same time the human owners from pathogens. Specific probiotic strains and/or their defined combinations may be useful in the canine and feline nutrition, therapy, and care. Probiotic supplementations have been successful in the prevention and treatment of acute gastroenteritis, treatment of IBD, and prevention of allergy in companion animals. New challenges for probiotic applications include maintenance of obesity and overweight, urogenital tract infections, Helicobacter gastritis and parasitic infections. The probiotics of human origin appear to be among the new promising tools for the maintenance of pets' health. However, the host-derived microorganisms might be the most appropriate probiotic source. Therefore, more controlled trials are needed to characterise new and safe probiotic preparations with an impact on general health and well being as well as health maintenance in dogs and cats.


      PubDate: 2015-05-20T01:33:39Z
       
  • Insight into alteration of gut microbiota in Clostridium difficile
           infection and asymptomatic C. difficile colonization
    • Abstract: Publication date: August 2015
      Source:Anaerobe, Volume 34
      Author(s): Lihua Zhang , Danfeng Dong , Cen Jiang , Zhen Li , Xuefeng Wang , Yibing Peng
      Clostridium difficile is well recognized as the common pathogen of nosocomial diarrhea, meanwhile, asymptomatic colonization with C. difficile in part of the population has also drawn public attention. Although gut microbiota is known to play an important role in the pathogenesis of C. difficile infection (CDI), whether there is any alteration of gut microbial composition in asymptomatic C. difficile carriers hasn't been clearly described. The purpose of this study was to explore the differences in gut microbiome among CDI patients, asymptomatic C. difficile carriers and healthy individuals. We performed fecal microbiota analysis on the samples of eight CDI patients, eight asymptomatic C. difficile carriers and nine healthy subjects using 16S rRNA gene pyrosequencing. CDI patients and asymptomatic carriers showed reduced microbial richness and diversity compared with healthy subjects, accompanied with a paucity of phylum Bacteroidetes and Firmicutes as well as an overabundance of Proteobacteria. Some normally commensal bacteria, especially butyrate producers, were significantly depleted in CDI patients and asymptomatic carriers. Furthermore, the differences observed in microbial community structure between CDI patients and asymptomatic carriers suggested that the gut microbiota may be a potential factor of disease state for CDI. Our study demonstrates the characterization and diversity of gut microbiota in CDI and asymptomatic C. difficile colonization, which will provide new ideas for surveillance of the disease state and development of microbiota-targeted agents for CDI prevention and treatment.


      PubDate: 2015-05-20T01:33:39Z
       
  • Molecular characterization and antimicrobial susceptibilities of
           Clostridium difficile clinical isolates from Victoria, Australia
    • Abstract: Publication date: August 2015
      Source:Anaerobe, Volume 34
      Author(s): Kate E. Mackin , Briony Elliott , Despina Kotsanas , Benjamin P. Howden , Glen P. Carter , Tony M. Korman , Thomas V. Riley , Julian I. Rood , Grant A. Jenkin , Dena Lyras
      Some Australian strain types of Clostridium difficile appear unique, highlighting the global diversity of this bacterium. We examined recent and historic local isolates, finding predominantly toxinotype 0 strains, but also toxinotypes V and VIII. All isolates tested were susceptible to vancomycin and metronidazole, while moxifloxacin resistance was only detected in recent strains.


      PubDate: 2015-05-20T01:33:39Z
       
  • Actinobaculum schaalii bacteremia: A report of two cases
    • Abstract: Publication date: August 2015
      Source:Anaerobe, Volume 34
      Author(s): Lemuel R. Non , Allison Nazinitsky , Mark D. Gonzalez , Carey-Ann D. Burnham , Rupa Patel
      We report two cases of bacteremia with Actinobaculum schaalii, a rarely reported, anaerobic, Gram-positive bacterium. The first case was a patient with renal cancer who developed pyelonephritis after cryoablation, and the second was a patient who developed sepsis after a urogenital procedure. Bacteremia resolved after administration of empiric antibiotic therapy.


      PubDate: 2015-05-20T01:33:39Z
       
  • Recurrent Clostridium difficile infection: From colonization to cure
    • Abstract: Publication date: August 2015
      Source:Anaerobe, Volume 34
      Author(s): Kelsey Shields , Roger V. Araujo-Castillo , Thimmaiah G. Theethira , Carolyn D. Alonso , Ciaran P. Kelly
      Clostridium difficile infection (CDI) is increasingly prevalent, dangerous and challenging to prevent and manage. Despite intense national and international attention the incidence of primary and of recurrent CDI (PCDI and RCDI, respectively) have risen rapidly throughout the past decade. Of major concern is the increase in cases of RCDI resulting in substantial morbidity, morality and economic burden. RCDI management remains challenging as there is no uniformly effective therapy, no firm consensus on optimal treatment, and reliable data regarding RCDI-specific treatment options is scant. Novel therapeutic strategies are critically needed to rapidly, accurately, and effectively identify and treat patients with, or at-risk for, RCDI. In this review we consider the factors implicated in the epidemiology, pathogenesis and clinical presentation of RCDI, evaluate current management options for RCDI and explore novel and emerging therapies.


      PubDate: 2015-05-20T01:33:39Z
       
  • Antibacterial activity of Lactobacillus spp. isolated from the feces of
           healthy infants against enteropathogenic bacteria
    • Abstract: Publication date: August 2015
      Source:Anaerobe, Volume 34
      Author(s): Abolfazl Davoodabadi , Mohammad Mehdi Soltan Dallal , Abbas Rahimi Foroushani , Masoumeh Douraghi , Mohammad kazem Sharifi Yazdi , Farzaneh Amin Harati
      Lactobacilli are normal microflora of the gastrointestinal (GI) tract and are a heterogeneous group of lactic acid bacteria (LAB). Lactobacillus strains with Probiotic activity may have health Benefits for human. This study investigates the probiotic potential of Lactobacillus strains obtained from the feces of healthy infants and also explores antibacterial activity of Lactobacillus strains with probiotic potential against enteropathogenic bacteria. Fecal samples were collected from 95 healthy infants younger than 18 months. Two hundred and ninety Lactobacillus strains were isolated and assessed for probiotic potential properties including ability to survive in gastrointestinal conditions (pH 2.0, 0.3% oxgall), adherence to HT-29 cells and antibiotic resistance. Six strains including L actobacillus fermentum (4 strains), Lactobacillus paracasei and Lactobacillus plantarum showed good probiotic potential and inhibited the growth of enteropathogenic bacteria including ETEC H10407, Shigella flexneri ATCC 12022, Shigella sonnei ATCC 9290, Salmonella ent e ritidis H7 and Yersinia enterocolitica ATCC 23715. These Lactobacillus strains with probiotic potential may be useful for prevention or treatment of diarrhea, but further in vitro and in vivo studies on these strains are still required.


      PubDate: 2015-05-20T01:33:39Z
       
  • A new medium containing mupirocin, acetic acid, and norfloxacin for the
           selective cultivation of bifidobacteria
    • Abstract: Publication date: August 2015
      Source:Anaerobe, Volume 34
      Author(s): Eva Vlková , Hana Salmonová , Věra Bunešová , Martina Geigerová , Vojtěch Rada , Šárka Musilová
      Various culture media have been proposed for the isolation and selective enumeration of bifidobacteria. Mupirocin is widely used as a selective factor along with glacial acetic acid. TOS (transgalactosylated oligosaccharides) medium supplemented with mupirocin is recommended by the International Dairy Federation for the detection of bifidobacteria in fermented milk products. Mupirocin media with acetic acid are also reliable for intestinal samples in which bifidobacteria predominate. However, for complex samples containing more diverse microbiota, the selectivity of mupirocin media is limited. Resistance to mupirocin has been demonstrated by many anaerobic bacteria, especially clostridia. The objective was to identify an antibiotic that inhibits the growth of clostridia and allows the growth of bifidobacteria, and to use the identified substance to develop a selective cultivation medium for bifidobacteria. The susceptibility of bifidobacteria and clostridia to 12 antibiotics was tested on agar using the disk diffusion method. Only norfloxacin inhibited the growth of clostridia and did not affect the growth of bifidobacteria. Using both pure cultures and faecal samples from infants, adults, calves, lambs, and piglets, the optimal concentration of norfloxacin in solid cultivation media was determined to be 200 mg/L. Our results showed that solid medium containing norfloxacin (200 mg/L) in combination with mupirocin (100 mg/L) and glacial acetic acid (1 mL/L) is suitable for the enumeration and isolation of bifidobacteria from faecal samples of different origins.


      PubDate: 2015-05-20T01:33:39Z
       
  • The role of anaerobes in diabetic foot infections
    • Abstract: Publication date: August 2015
      Source:Anaerobe, Volume 34
      Author(s): Patrick G.P. Charles , Ilker Uçkay , Benjamin Kressmann , Stéphane Emonet , Benjamin A. Lipsky
      Diabetic foot infections (DFI) are a common cause of morbidity and, on occasion, even mortality. Infection can be either mono- or polymicrobial, with a wide variety of potential pathogens. Anaerobes may be involved, particularly in wounds that are deeper or more chronic, and are more frequently identified when using modern molecular techniques, such as 16s PCR and pyrosequencing. It remains unclear whether the presence of anaerobes in DFI leads to more severe manifestations, or if these organisms are largely colonizers associated with the presence of greater degrees of tissue ischemia and necrosis. Commonly used empiric antibiotic therapy for diabetic foot infections is generally broad-spectrum and usually has activity against the most frequently identified anaerobes, such as Peptostreptococcus and Bacteroides species. Adequate surgical debridement and, when needed, foot revascularization may be at least as important as the choice of antibiotic to achieve a successful treatment outcome.


      PubDate: 2015-05-20T01:33:39Z
       
 
 
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