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Developmental Cell     Full-text available via subscription   (Followers: 33)
Developmental Dynamics     Hybrid Journal   (Followers: 2)
Developmental Neurobiology     Hybrid Journal   (Followers: 4)
Developments in Marine Biology     Full-text available via subscription   (Followers: 9)
Dhaka University Journal of Biological Sciences     Open Access  
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Differentiation     Hybrid Journal   (Followers: 1)
Disease Models and Mechanisms     Open Access   (Followers: 1)
DNA and Cell Biology     Hybrid Journal   (Followers: 5)
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DNA Research     Open Access   (Followers: 3)
Doklady Physics     Hybrid Journal   (Followers: 1)
Drug Discovery Today     Full-text available via subscription   (Followers: 89)
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Drug Resistance Updates     Hybrid Journal   (Followers: 3)
e-Neuroforum     Hybrid Journal  
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Ecología en Bolivia     Open Access  
Ecological Engineering     Hybrid Journal   (Followers: 5)
Ecological Questions     Open Access   (Followers: 6)
Ecology and Society     Open Access   (Followers: 31)
Ecology Letters     Hybrid Journal   (Followers: 161)
Economics & Human Biology     Hybrid Journal  
Ecoprint : An International Journal of Ecology     Open Access   (Followers: 2)
Ecoscience     Full-text available via subscription   (Followers: 3)
Educational Technology Research and Development     Partially Free   (Followers: 64)
Egyptian Journal of Basic and Applied Sciences     Open Access  
Egyptian Journal of Biology     Open Access  
Egyptian Journal of Histology     Partially Free   (Followers: 1)
Egyptian Journal of Natural History     Open Access   (Followers: 1)
EJNMMI Research     Open Access   (Followers: 1)
Ekológia (Bratislava) : The Journal of Institute of Landscape Ecology of Slovak Academy of Sciences     Open Access  
el-Hayah     Open Access   (Followers: 1)
Electromagnetic Biology and Medicine     Hybrid Journal   (Followers: 1)
eLife     Open Access   (Followers: 29)
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Emotion Review     Hybrid Journal   (Followers: 13)
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Engineering Economist, The     Hybrid Journal   (Followers: 3)
Engineering in Life Sciences     Hybrid Journal   (Followers: 4)
Engineering Optimization     Hybrid Journal   (Followers: 8)
Ensaios e Ciência: Ciências Biológicas, Agrárias e da Saúde     Open Access  
Environmental Biology of Fishes     Hybrid Journal   (Followers: 5)
Environmental Biosafety Research     Hybrid Journal   (Followers: 1)
Environmental Microbiology     Hybrid Journal   (Followers: 14)
Environmental Science & Technology     Full-text available via subscription   (Followers: 134)
Enzyme and Microbial Technology     Hybrid Journal   (Followers: 7)
Enzyme Research     Open Access   (Followers: 4)
Epidemiology & Infection     Hybrid Journal   (Followers: 15)
Epigenetics in Cancer     Open Access   (Followers: 1)
EPMA Journal     Open Access  
ESHRE Monographs     Hybrid Journal  
Ethiopian Journal of Biological Sciences     Open Access   (Followers: 5)
Ethnobiology and Conservation     Open Access   (Followers: 3)
Ethnobotany Research & Applications : a journal of plants, people and applied research     Open Access   (Followers: 6)
Ethology     Hybrid Journal   (Followers: 6)
Ethology Ecology & Evolution     Hybrid Journal   (Followers: 13)
Eukaryotic Cell     Full-text available via subscription   (Followers: 7)
EuPA Open Proteomics     Open Access   (Followers: 1)
EURASIP Journal on Bioinformatics and Systems Biology     Open Access   (Followers: 7)
European Journal of Biological Research     Open Access   (Followers: 3)
European Journal of Cell Biology     Hybrid Journal   (Followers: 3)
European Journal of Neuroscience     Hybrid Journal   (Followers: 30)
European Journal of Phycology     Hybrid Journal   (Followers: 6)
European Journal of Protistology     Hybrid Journal   (Followers: 3)
European Journal of Soil Biology     Hybrid Journal   (Followers: 2)
European Online Journal of Natural and Social Sciences     Open Access   (Followers: 14)
European Scientific Journal     Open Access   (Followers: 2)
Evidência - Ciência e Biotecnologia - Interdisciplinar     Open Access  
EvoDevo     Open Access   (Followers: 1)
Evolução e Conservação da Biodiversidade     Open Access  
Evolution     Partially Free   (Followers: 112)
Evolution and Human Behavior     Hybrid Journal   (Followers: 13)
Evolutionary Applications     Open Access   (Followers: 5)
Evolutionary Bioinformatics     Open Access   (Followers: 15)
Evolutionary Biology     Hybrid Journal   (Followers: 19)
Evolutionary Computation     Hybrid Journal   (Followers: 10)
Experimental & Molecular Medicine     Open Access   (Followers: 2)
Experimental and Applied Acarology     Hybrid Journal   (Followers: 1)
Experimental Cell Research     Hybrid Journal   (Followers: 4)
Expert Opinion on Biological Therapy     Hybrid Journal   (Followers: 9)
Expert Opinion on Environmental Biology     Hybrid Journal  
Expert Review of Proteomics     Hybrid Journal   (Followers: 3)
Extreme Life, Biospeology & Astrobiology - International Journal of the Bioflux Society     Full-text available via subscription   (Followers: 5)
Extremophiles     Hybrid Journal   (Followers: 1)
F1000Research     Open Access   (Followers: 4)
Facta Universitatis, Series : Medicine and Biology     Open Access  
Familial Cancer     Hybrid Journal   (Followers: 1)
Fatigue & Fracture of Engineering Materials and Structures     Hybrid Journal   (Followers: 14)
Fauna Norvegica     Open Access  
Fauna of New Zealand     Open Access  
Febs Journal     Hybrid Journal   (Followers: 15)
Feddes Repertorium     Hybrid Journal  
Fems Yeast Research     Hybrid Journal   (Followers: 12)
Field Mycology     Full-text available via subscription   (Followers: 2)

  First | 1 2 3 4 5 6 7 8 | Last

Journal Cover Anaerobe
  [SJR: 1.09]   [H-I: 44]   [3 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1075-9964 - ISSN (Online) 1095-8274
   Published by Elsevier Homepage  [2801 journals]
  • Factors predictive of severe Clostridium difficile infection depend on the
           definition used
    • Abstract: Publication date: February 2016
      Source:Anaerobe, Volume 37
      Author(s): Nagham Khanafer, Frédéric Barbut, Catherine Eckert, Michel Perraud, Clarisse Demont, Christine Luxemburger, Philippe Vanhems
      Context Clostridium difficile infection (CDI) produces a variety of clinical presentations ranging from mild diarrhea to severe infection with fulminant colitis, septic shock, and death. Over the past decade, the emergence of the BI/NAP1/027 strain has been linked to higher prevalence and severity of CDI. The guidelines to treat patients with CDI are currently based on severity factors identified in the literature and on expert opinion and have not been systematically evaluated. Objective The objective of this study was to identify factors associated with severe CDI defined according to four different severity definitions (Def): the 2010 SHEA/IDSA guidelines (Def1), the 2014 ESCMID guidelines (Def2), complicated CDI at the end of diarrhea (Def3), and our hospital-specific guidelines (white blood cell (WBC) count ≥15 × 109/L, serum creatinine concentration >50% above baseline, pseudomembranous colitis, megacolon, intestinal perforation, or septic shock requiring intensive care unit admission. Methods A three-year cohort study was conducted in a university hospital in Lyon, France. All hospitalized (≥48 h) patients ≥18 years old, suffering from CDI, and agreeing to participate were included. Patients were followed-up for 60 days after CDI diagnosis. After bivariate regression analyses, factors associated with severe CDI during the course of disease were identified by a multivariate logistic regression. Statistical significance was reached with a two-sided p-value <0.05. Results 233 CDI patients diagnosed between 2011 and 2014 were included for a mean incidence rate of 2.15 cases/1000 hospitalized patients or 3.16 cases/10,000 patient days. Mean age was 65.3 years and 52.5% were men. Death occurred in 37 patients (15.9%) within 60 days of diagnosis. Death was related to CDI in 15 patients (40.5%). Frequency of severe CDI ranges from 11.6% to 59.2% depending on the case-definition. Factors independently associated with severe CDI were: age ≥68 years, male gender, renal disease, and serum albumin <30 g/L according to Def1 (n = 106, 45.5%); exposure to antivirals in the previous 4 weeks, renal disease, and blood neutrophils >7,5 × 109/L in patients with Def2 (n = 138, 59.2%); abdominal pain, serum albumin <30 g/L, and WBC >10 × 109/L according to Def3 (n = 27, 11.6%); age ≥68 years, renal disease, serum albumin <30 g/L, serum lactate dehydrogenase >248 IU/L, and blood neutrophils >7,5 × 109/L were associated with severe CDI in patients with Def4 (n = 113, 48.5%). Conclusions Our results indicate that appropriate case definition is needed for characterizing patients at risk of developing severe CDI. Our study suggest that serum albumin and the presence of renal disease, associated with severe CDI in three definitions, may be useful for identifying patients at risk of a poor outcome.

      PubDate: 2016-02-10T17:47:36Z
  • Clinical significance of direct cytotoxicity and toxigenic culture in
           Clostridium difficile infection
    • Abstract: Publication date: February 2016
      Source:Anaerobe, Volume 37
      Author(s): E. Reigadas, L. Alcalá, M. Marín, P. Muñoz-Pacheco, P. Catalán, A. Martin, E. Bouza
      Background Clostridium difficile infection (CDI) is the leading cause of hospital-acquired diarrhoea in developed countries. Although an optimal diagnosis is crucial, laboratory diagnostics remain challenging. Currently, the reference methods are direct cytotoxicity assay and toxigenic culture; however there is controversy in the interpretation of discordant results of these tests. Objective The aim of our study was to determine the clinical significance of detecting C. difficile only by toxigenic culture with a negative direct cytotoxicity assay. Methods We conducted a prospective study in which patients aged >2 years with CDI were enrolled and monitored at least 2 months after their last episode. Samples were tested by both cytotoxicity assay and toxigenic culture. Results During the 6-month study period, we identified 169 episodes meeting CDI criteria that had been tested by both assays, out of which 115 were positive for both cytotoxicity assay and toxigenic culture, and 54 CDI episodes (31.9%) were positive only by toxigenic culture. Overall, patients median age was 71.3, 50.9% were male and the most frequent underlying disease was malignancy. The comparison of CDI episodes positive for both assays and by toxigenic culture only revealed the following, respectively: mild CDI (77.4% vs 94.4%; p = 0.008), severe CDI (21.7% vs 5.6%; p = 0.008), severe complicated (0.9% vs 0.0%; p = 1.000), pseudomembranous colitis (1.7% vs 1.9% p = 1.000), recurrence (17.4% vs 14.8%; p = 0.825), overall mortality (8.7% vs 7.4%; p = 1.000) and CDI related mortality (2.6% vs 0%; p = 0.552). Conclusion CDI episodes positive by cytotoxicity assay were more severe than those positive only by toxigenic culture, however there were a significant proportion of CDI cases (31.9%) that would have been missed if only cytotoxicity had been considered as clinically significant for CDI treatment, including severe CDI cases. Our data suggest that a positive test by toxigenic culture with a negative result for cytotoxicity should not be interpreted as colonization.

      PubDate: 2016-02-10T17:47:36Z
  • Virulence factors of Clostridium difficile and their role during infection
    • Abstract: Publication date: February 2016
      Source:Anaerobe, Volume 37
      Author(s): Claire Janoir
      Clostridium difficile is the prominent etiological agent of healthcare-associated diarrhea. The disease symptoms range from mild diarrhea to life-threatening pseudomembranous colitis. The main risk factor for developing an infection after contamination by the resistant spores is the disruption of the gut microbiota, allowing the spores to germinate. The colonization of the gut is likely to be governed by the bacterial resistance to the host response and the bacterial adhesion to the mucosa. To date, several putative adhesins have been identified, most of them displaying MSCRAMM function, and studies of adhesin mutants have clearly underlined the multi-factorial feature of C. difficile adhesion to the host. Flagella have also been involved in the colonisation process, but their role depends on the tested strains. The clinical signs are mainly due to two large glucosylating toxins, TcdA and TcdB, which are essential for the disease manifestations. The importance of each toxin differs according to strains and experimental conditions, but TcdB seems to be the prominent one, as showed by mutant studies and the natural occurrence of pathogenic strains that do not produce TcdA. The role of the ADP ribosylating binary toxin expressed by some strains, including epidemic lineages, is not clearly established, although it has been related to higher morbidity and mortality. Production of low level of the glucosylating toxins and of the binary toxin seems to promote adhesion to host cells. Expression of the tcdA and tcdB genes is under the control of the second messenger c-di-GMP. This is also the case for other virulence factors, in particular for flagellar, pili type IV and some adhesin genes. Indeed, several studies using knock-out mutants suggest that C. difficile may undergo a switch between the adhesion phenotype and the motility phenotype during the course of infection, regulated by the c-di-GMP intracellular level. In vivo, this could result in biofilm formation that, associated with persistence of spores, could promote the occurrence of relapses observed in at least 20% of patients.

      PubDate: 2016-02-10T17:47:36Z
  • Editorial board
    • Abstract: Publication date: February 2016
      Source:Anaerobe, Volume 37

      PubDate: 2016-02-10T17:47:36Z
  • Introduction to the special issue on Clostridium difficile and the history
           of the International Clostridium difficile Symposium (ICDS)
    • Abstract: Publication date: February 2016
      Source:Anaerobe, Volume 37
      Author(s): Maja Rupnik, Paola Mastrantonio

      PubDate: 2016-02-10T17:47:36Z
  • Performance management of Clostridium difficile infection in hospitals
           – The carrot or stick approach'
    • Abstract: Publication date: February 2016
      Source:Anaerobe, Volume 37
      Author(s): Fidelma Fitzpatrick, Mary O. Riordan
      Public and political pressure for healthcare quality indicator monitoring, specifically healthcare-associated infection (HAI) has intensified the debate regarding the merits of public reporting and target setting as policy approaches. This paper reviews the evidence for these approaches with a focus on HAI, including Clostridium difficile infection (CDI). Healthcare key performance indicators (KPIs) and associated targets have been used widely with little evaluation. While targets are associated with some HAI reductions including CDI, as their control is multi-factorial, it is likely that reductions are due to numerous, concurrent control measures. Targets may help tackle organizational-wide issues that require high level management engagement and have contributed to the increased access and influence of infection control teams. HAI public reporting has also gained traction and is mandatory in many countries despite little scientific evaluation. CDI is one of the KPIs used but there is little consensus as to the best KPI for public reporting. Countries without public reporting have also seen improvements. Using indicator-based strategies rather than evidence-based ones risk improving the KPI but not necessarily quality of care. ‘Bottom-up’ approaches focussing on quality improvement and innovation generated by front line staff are seen as a lever for sustainable change. Positive deviance, where the resourcefulness and problem solving abilities of staff is harnessed, enables ‘bottom-up’ changes with process and outcome improvements. As implementation of best practice in healthcare is dependent on behavioural and cultural change, it is most likely that a combination of ‘top-down’ and ‘bottom-up’ approaches are required for sustainable improvement. This combined approach was used to improve staff influenza vaccination rates. Regulation may initially direct the spot-light onto infection control needs but true sustainable HAI reduction will only be fostered with concurrent cultural and behavioural shifts in practice and ownership of the HAI burden across clinical, policy and management domains. It will be interesting if this approach will be increasingly used by policy makers, however, irrespective it is clear that there is a need for rigorous evaluation of our HAI policy approaches from this point forward.

      PubDate: 2016-02-10T17:47:36Z
  • Rumen microbial abundance and fermentation profile during severe subacute
           ruminal acidosis and its modulation by plant derived alkaloids in vitro
    • Abstract: Publication date: Available online 8 February 2016
      Author(s): Elsayed Mickdam, Ratchaneewan Khiaosa-ard, Barbara U. Metzler-Zebeli, Fenja Klevenhusen, Remigius Chizzola, Qendrim Zebeli
      Rumen microbiota have important metabolic functions for the host animal. This study aimed at characterizing changes in rumen microbial abundances and fermentation profiles using a severe subacute ruminal acidosis (SARA) in vitro model, and to evaluate a potential modulatory role of plant derived alkaloids (PDA), containing quaternary benzophenanthridine and protopine alkaloids, of which sanguinarine and chelerythrine were the major bioactive compounds. Induction of severe SARA strongly affected the rumen microbial composition and fermentation variables without suppressing the abundance of total bacteria. Protozoa and fungi were more sensitive to the low ruminal pH condition than bacteria. Induction of severe SARA clearly depressed degradation of fiber (P < 0.001), which came along with a decreased relative abundance of fibrolytic Ruminococcus albus and Fibrobacter succinogenes (P < 0.001). Under severe SARA conditions, the genus Prevotella, Lactobacillus group, Megasphaera elsdenii, and Entodinium spp. (P < 0.001) were more abundant, whereas Ruminobacter amylophilus was less abundant. SARA largely suppressed methane formation (-70%, P < 0.001), although total methanogenic 16S rRNA gene abundance was not affected. According to principal component analysis, Methanobrevibacter spp. correlated to methane concentration. Addition of PDA modulated ruminal fermentation under normal conditions such as enhanced (P < 0.05) concentration of total SCFA, propionate and valerate, and increased (P < 0.05) degradation of crude protein compared with the unsupplemented control diet. Our results indicate strong shifts in the microbial community during severe SARA compared to normal conditions. Supplementation of PDA positively modulates ruminal fermentation under normal ruminal pH conditions.
      Graphical abstract image

      PubDate: 2016-02-10T17:47:36Z
  • Immunogenic properties of the surface layer precursor of Clostridium
           difficile and vaccination assays in animal models
    • Abstract: Publication date: February 2016
      Source:Anaerobe, Volume 37
      Author(s): J.-F. Bruxelle, A. Mizrahi, S. Hoys, A. Collignon, C. Janoir, S. Péchiné
      Clostridium difficile is an opportunistic pathogen causing gut inflammation generally associated with an intestinal dysbiosis due to antibiotics. Several virulence factors have been identified as playing a key role in gut colonization. The surface-layer proteins, comprised of two proteins, the high molecular weight SlpA (HMW-SLP) and the low molecular weight SlpA (LMW-SLP), are the most abundant proteins on the C. difficile surface. These two proteins are derived from the Cwp84-mediated cleavage of a single precursor protein SlpA. In this study, we assessed the immunogenic properties of a recombinant SlpA precursor derived from a toxigenic C. difficile strain (630) and its protective effect as a vaccine antigen co-administered with the cholera toxin as an adjuvant in both hamster and mouse models. First, we confirmed the immunogenicity of SlpA in humans. Sera from patients with C. difficile infection were analyzed by ELISA. Patients with CDI have a greater number of SlpA antibodies than healthy patients, confirming the immunogenicity of this protein during the pathogenic process. Then, rectal vaccination assays were performed in both conventional hamsters and mice. The animals’ sera were sampled before and after vaccination, and were analyzed by ELISA. In addition, in the mouse model, feces were sampled after vaccination and IgA directed against SlpA were detected by ELISA. In both models, the intestinal colonization was evaluated by fecal bacterial count after challenge. Intra-rectal vaccination with SlpA and cholera toxin as an adjuvant induced a local and systemic humoral immune response in mice and hamsters potentially responsible for the weak decrease of C. difficile colonization in mice and the partial protection observed in a lethal-hamster model.

      PubDate: 2016-02-10T17:47:36Z
  • Distribution and characterization of Clostridium difficile isolated from
           dogs in Japan
    • Abstract: Publication date: February 2016
      Source:Anaerobe, Volume 37
      Author(s): Masaru Usui, Kaname Suzuki, Kentaro Oka, Kentaro Miyamoto, Motomichi Takahashi, Takashi Inamatsu, Shigeru Kamiya, Yutaka Tamura
      We collected 204 nondiarrhoeic canine fecal samples and isolated 68 Clostridium difficile strains from 62 of these samples. Strains were grouped into 29 PCR ribotypes. Only 47% of the strains were toxigenic.

      PubDate: 2016-02-10T17:47:36Z
  • Case series of patients with Fusobacterium nucleatum bacteremia with
           emphasis on the presence of cancer
    • Abstract: Publication date: June 2016
      Source:Anaerobe, Volume 39
      Author(s): Erlangga Yusuf, Ingrid Wybo, Denis Piérard
      Fusobacterium nucleatum is anaerobic oral microbiota that might be associated with cancer. We reported 22 consecutive cases of patients (mean age of 63.8 years (range 34–89), 59.1% male) with F. nucleatum bacteremia that were admitted to a university hospital over a 10-year period. In 17 (77.2%) of these patients, F. nucleatum was the sole possible pathogen. Seven of the 22 patients (31.8%) had active cancer: esophagus carcinoma (n = 3), hematologic malignancies (n = 1), gastrointestinal stromal tumor (n = 1), melanoma (n = 1), and breast cancer (n = 1). In six out of seven patients (85.7%), the F. nucleatum was found within six months of the diagnosis of cancer. Four of seven (57.1%), patients with cancer were on chemotherapy. Three of 22 patients (13.4%) died within 1 month of F. nucleatum bacteremia due to cancer. In conclusion, F. nucleatum bacteremia occurs rarely and when it is found, it is often in patients with cancer, especially those with a recent diagnosis.

      PubDate: 2016-02-10T17:47:36Z
  • Clostridium difficile recurrences in Stockholm
    • Abstract: Publication date: Available online 21 January 2016
      Author(s): Staffan Sandell, Mamun-Ur Rashid, Christina Jorup-Rönström, Kristina Ellström, Carl Erik Nord, Andrej Weintraub
      Sixty-eight hospital-admitted patients with a first episode of Clostridium difficile infection (CDI) were included and followed up during 1 year. Faeces samples were collected at 1, 2, 6 and 12 months after inclusion and analyzed for the presence of C. difficile toxin B, genes for toxin A, toxin B, binary toxin and TcdC deletion by PCR. All strains were also PCR-ribotyped and the MICs of the isolates were determined against eight antimicrobial agents. In 68 patients initially included, antibiotics, clinical signs and co-morbidities were analyzed and 56 were evaluable for recurrences. The mean number of different antibiotics given during 3 months prior to inclusion was 2.6 (range 0-6). Six patients had not received any antibiotics and three of them had diagnosed inflammatory bowel disease. Thirty-two patients (57%) had either a microbiological or clinical recurrence, 16 of whom had clinical recurrences that were confirmed microbiologically (13, 23%) or unconfirmed by culture (3, 5%). Twenty-nine patients were positive in at least one of the follow-up tests, 16 had the same ribotype in follow-up tests, i.e. relapse, and 13 a different ribotype, i.e., reinfection. Most common ribotypes were 078/126, 020, 023, 026, 014/077, 001 and 005. No strain of ribotype 027 was found. Strains ribotype 078/126 and 023 were positive for binary toxin and were the strains most prone to cause recurrence. All strains were sensitive to vancomycin and metronidazole. Patients with recurrences were significantly older (p=0.02) and all patients had a high burden of comorbidities, which could explain the high fatality rate, 26 (38%) patients died during the 1-year follow-up.

      PubDate: 2016-01-21T16:21:49Z
  • A novel murine model of Clostridium sordellii myonecrosis: Insights into
           the pathogenesis of disease
    • Abstract: Publication date: Available online 21 January 2016
      Author(s): Michael J. Aldape, Clifford R. Bayer, Amy E. Bryant, Dennis L. Stevens
      Clostridium sordellii infections have been reported in women following natural childbirth and spontaneous or medically-induced abortion, injection drug users and patients with trauma. Death is rapid and mortality ranges from 70-100%. Clinical features include an extreme leukemoid reaction, the absence of fever, and only minimal pain or erythema at the infected site. In the current study, we developed a murine model of C. sordellii soft tissue infection to elucidate the pathogenic mechanisms. Mice received 0.5, 1.0 or 2.0 x 106 CFU C. sordellii (ATCC 9714 type strain) in the right thigh muscle. All doses caused fatal infection characterized by intense swelling of the infected limb but no erythema or visible perfusion deficits. Survival rates and time to death were inoculum dose-dependent. Mice developed a granulocytic leukocytosis with left shift, the onset of which directly correlated with disease severity. Histopathology of infected tissue showed widespread edema, moderate muscle damage and minimal neutrophil infiltration. Circulating levels of granulocyte colony-stimulating factor (G-CSF), soluble tumor necrosis factor receptor I (sTNF-RI) and interlukin-6 (IL-6) were significantly increased in infected animals, while TNF-α, and IL-1β levels were only mildly elevated, suggesting these host factors likely mediate the leukocytosis and innate immune dysfunction characteristic of this infection. Thus, this model mimics many of the salient features of this infection in humans and has allowed us to identify novel targets for intervention.

      PubDate: 2016-01-21T16:21:49Z
  • Corrigendum to “Cloning and characterization of l-lactate
           dehydrogenase gene of Staphylococcus aureus” [Anaerobe 24 (2013)
    • Abstract: Publication date: Available online 14 January 2016
      Author(s): Sthanikam Yeswanth, Yellapu Nanda Kumar, Uppu Venkateswara Prasad, Vimjam Swarupa, Valasani Koteswara Rao, Potukuchi Venkata Gurunadha Krishna Sarma

      PubDate: 2016-01-17T16:07:36Z
  • Clostridium difficile flagella predominantly activate TLR5-linked
           NF-κB pathway in epithelial cells
    • Abstract: Publication date: Available online 11 January 2016
      Author(s): Jameel Batah, Cécile Denève-Larrazet, Pierre-Alain Jolivot, Sarah Kuehne, Anne Collignon, Jean-Christophe Marvaud, Imad Kansau
      Clostridium difficile has become the most common enteropathogen responsible for intestinal nosocomial post-antibiotic infections. This has coincided with the appearance of serious cases related to the emergence of hypervirulent strains. The toxins are the main virulence factors and elicit an inflammatory response during C. difficile infection. However, other bacterial components appear to be involved in the inflammatory process. In some pathogens, flagella play a role in pathogenesis through abnormal stimulation of the TLR5-mediated host immune response. To date, few studies have addressed this role for C. difficile flagella. In the current study, we confirm in two different epithelial cell models that C. difficile thanks to its FliC flagellin interact with TLR5. In addition, thanks to inhibition and transcriptomic studies we demonstrate that the interaction of flagellin and TLR5 predominantly activates the NF-κB and, in a lesser degree, the MAPK pathways, via TLR5, leading to up-regulation of pro-inflammatory gene expression and synthesis of pro-inflammatory mediators. These results suggest a role for C. difficile flagella in contributing to inflammatory response in host intestinal cells.

      PubDate: 2016-01-13T15:55:30Z
  • Clostridium perfringens type A netF and netE positive and C. difficile
           co-infection in two adult dogs
    • Abstract: Publication date: Available online 4 January 2016
      Author(s): Amanda Nádia Diniz, Rodrigo Otávio Silveira Silva, Carlos Augusto Oliveira Junior, Felipe Pierezan, Francisco Carlos Faria Lobato
      The aim of this study was to report two cases of Clostridium perfringens type A and C. difficile co-infection in adult dogs. Both animals were positive for A/B toxin. Toxigenic C. difficile and C. perfringens type A positive for NetE and NetF-encoding genes were isolated. This report reinforces the necessity of studying a possible synergism of C. difficile and C. perfringens in enteric disorders.

      PubDate: 2016-01-05T14:30:13Z
  • Multidrug resistance in Clostridium perfringens isolated from diarrheal
           neonatal piglets in Thailand
    • Abstract: Publication date: Available online 2 January 2016
      Author(s): Bhinyada Ngamwongsatit, Wimonrat Tanomsridachchai, Orasa Suthienkul, Supanee Urairong, Wichian Navasakuljinda, Tavan Janvilisri
      Clostridium perfringens causes diarrhea in neonatal piglets, thereby affecting commercial swine farming. The objective of this study was to determine the prevalence and characterize antimicrobial resistance in C. perfringens isolated from diarrheal neonatal piglets in Thailand. A total of 260 rectal swab samples were collected from 13 farms and were subjected to C. perfringens isolation. A total of 148 samples were PCR-positive for C. perfringens toxin genes, from which 122 were recovered. All isolates were cpb2-encoding C. perfringens type A and enterotoxin gene negative. Most of the isolates were susceptible to ampicillin, bacitracin, chlorotetracycline, doxycycline, and oxytetracycline with MIC50 values ranging from 0.32 – 8 μg/ml. The high resistance rates were observed for ceftiofur, enrofloxacin, erythromycin, lincomycin, and tylosin. Among resistant isolates, 82% were resistant to more than one type of antibiotics. The distinct pattern of multiple drug resistance in C. perfringens was observed in different regions, potentially reflecting the farm specific usage of these agents.

      PubDate: 2016-01-05T14:30:13Z
  • Survival of the ovine footrot pathogen Dichelobacter nodosus in different
    • Abstract: Publication date: Available online 30 December 2015
      Author(s): Mohd Muzafar, Laura E. Green, Leo A. Calvo-Bado, Esther Tichauer, Hayley King, Philip James, Elizabeth M.H. Wellington
      Dichelobacter nodosus (D. nodosus) is the causative agent of footrot in sheep; one of the most important health and welfare issues of sheep worldwide. For control programmes to be effective, it is essential that the transmission cycle of D. nodosus is understood and bacterial reservoirs in the environment are better defined. This study evaluated the survival of D. nodosus in different soils using soil microcosms. Cultivation independent and dependent methods were used to detect D. nodosus over 40 days from seeding in soil. A D. nodosus specific probe was used for quantification by qPCR and viability was assessed by cell permeability to an intercalating dye, PMA, and by culture. Survival varied dramatically depending on soil type, matric potential (MP) and temperature. Our findings indicate that D. nodosus survival was higher at 5 oC compared with 25 o C in all soils and significantly longer at both temperatures in clay soil (>44% clay) compared with other soil types. Survival under all conditions was longer than 30 days for both culture independent and dependent methods, this is substantially longer than previous studies and, if this is an infectious dose, longer than the current recommendation of resting a field for 14 days to prevent onward infection.

      PubDate: 2016-01-01T14:13:40Z
  • Clostridium difficile associated reactive arthritis: case report and
           literature review
    • Abstract: Publication date: Available online 30 December 2015
      Author(s): Paul Legendre, Valérie Lalande, Catherine Eckert, Fréderic Barbut, Laurence Fardet, Jean-Luc Meynard, Laure Surgers
      Introduction Extra-gastro-intestinal tract manifestations associated with Clostridium difficile infection (CDI), including reactive arthritis (ReA), are uncommon. Method We report a case of ReA associated with a relapse of CDI in a 46-year-old woman. A toxigenic C. difficile strain was isolated from stools and characterized as PCR-ribotype 014/020/077. We conducted a comprehensive literature review of ReA associated with CDI (ReA-CDI). Diagnostic criteria for ReA-CDI were: (i) evidence of aseptic synovitis (confirmed by culture) developing during or immediately after colitis, (ii) presence of a toxigenic C. difficile strain in stool samples, and (iii) absence of other causes of colitis and arthritis. Results Forty-nine cases of ReA-CDI (excluding the present report) have already been described since 1976. Of these reports, Mean age of patients was 38 years (SD: 18.5), 46% were male, and 68% had HLA B27 genotype. Sixty-nine percent of patients received a β-lactamin treatment before CDI. ReA-CDI occurred a median 10 days (range 0-55 days) after CDI. Outcome was favorable in 90% of patients and oral non anti-inflammatory drugs were required for 55%. Conclusion ReA-CDI remains uncommon. Compared to the general population, it is more likely observed in younger patients with HLA B27-positive genotype.

      PubDate: 2016-01-01T14:13:40Z
  • Effects of the dietary protein level on the microbial composition and
           metabolomic profile in the hindgut of the pig
    • Abstract: Publication date: Available online 24 December 2015
      Author(s): Liping Zhou, Lingdong Fang, Yue Sun, Yong Su, Weiyun Zhu
      The aim of this study was to investigate the effects of a long-term low protein diet on the microbial composition and metabolomic profile in the hindgut of the pig. Thirty-six Duroc × Landrace × Large White growing barrows (70 days of age, 23.57 ± 1.77 kg) were randomly allocated to normal protein diet (NP) and low protein diet (LP) groups using a randomized block design. At the age of 170 days, the digesta in the hindguts of the pigs were collected for microbial and metabolomic analysis. The results showed that there were no significant differences in the average daily gain, average daily feed intake, or feed:gain ratio between the NP and LP groups. The concentrations of isobutyrate, isovalerate, and branched-chain fatty acids (BCFAs)/short-chain fatty acids (SCFAs) in the cecum decreased with the reduction of dietary protein. Pyrosequencing of the V1–V3 region of the 16S rRNA genes showed that LP diet significantly decreased the relative abundance of Lactobacillus in the cecum, and Streptococcus in the colon; however, the relative abundance of Prevotella and Coprococcus in the LP group was significantly higher than in the NP group in the cecum, and Sarcina, Peptostreptococcaceae incertae sedis, Mogibacterium, Subdoligranulum, and Coprococcus was higher in the colon. The gas chromatography–mass spectrometry (GC–MS) analysis showed that the dietary protein level mainly affected phenylalanine metabolism; glycine, serine, and threonine metabolism; the citrate cycle; pyruvate metabolism; and the alanine, aspartate, and glutamate metabolism. Moreover, the correlation analysis of the combined datasets revealed some potential relationships between the colonic metabolites and certain microbial species. These results suggest that a low protein diet may modulate the microbial composition and metabolites of the hindgut, without affecting the growth performance of pigs; however, potential roles of this modulation to the health of pigs remains unknown.

      PubDate: 2015-12-28T13:49:25Z
  • Synergistic efficacy of 405 nm light and chlorinated disinfectants for the
           enhanced decontamination of Clostridium difficile spores
    • Abstract: Publication date: Available online 18 December 2015
      Author(s): Sian Moorhead, Michelle Maclean, John E. Coia, Scott J. MacGregor, John G. Anderson
      The ability of Clostridium difficile to form highly resilient spores which can survive in the environment for prolonged periods causes major contamination problems. Antimicrobial 405nm light is being developed for environmental decontamination within hospitals, however further information relating to its sporicidal efficacy is required. This study aims to establish the efficacy of 405nm light for inactivation of C. difficile vegetative cells and spores, and to establish whether spore susceptibility can be enhanced by the combined use of 405nm light with low concentration chlorinated disinfectants. Vegetative cells and spore suspensions were exposed to increasing doses of 405nm light (at 70-225 mW/cm2) to establish sensitivity. A 99.9% reduction in vegetative cell population was demonstrated with a dose of 252 J/cm2, however spores demonstrated higher resilience, with a 10-fold increase in required dose. Exposures were repeated with spores suspended in the hospital disinfectants sodium hypochlorite, Actichlor and Tristel at non-lethal concentrations (0.1%, 0.001% and 0.0001%, respectively). Enhanced sporicidal activity was achieved when spores were exposed to 405nm light in the presence of the disinfectants, with a 99.9% reduction achieved following exposure to 33% less light dose than required when exposed to 405nm light alone. In conclusion, C. difficile vegetative cells and spores can be successfully inactivated using 405nm light, the sporicidal efficacy can be significantly enhanced when exposed in the presence of low concentration chlorinated disinfectants. Further research may lead to the potential use of 405nm light decontamination in combination with selected hospital disinfectants to enhance C. difficile cleaning and infection control procedures.

      PubDate: 2015-12-20T13:05:47Z
  • Clostridium difficile-mediated effects on human intestinal epithelia:
           Modelling host-pathogen interactions in a vertical diffusion chamber
    • Abstract: Publication date: Available online 19 December 2015
      Author(s): Nazila V. Jafari, Sarah A. Kuehne, Nigel P. Minton, Elaine Allan, Mona Bajaj-Elliott
      C. difficile infection is one of the leading causes of healthcare associated diarrhoea in the developed world. Although the contribution of C. difficile toxins to disease pathogenesis is now well understood, many facets of host-pathogen interactions between the human intestinal epithelia and the C. difficile bacterium that may contribute to asymptomatic carriage and/or clinical disease remain less clear. Herein, we tested the hypothesis that C. difficile strains mediate intestinal epithelial cell (IEC) antimicrobial immunity via toxin dependent and independent means and that the ‘anaerobic’ environment has a significant impact on bacterial-IEC interactions. Crosstalk between three C. difficile PCR ribotypes (RT) [RT027 (strain R20291), RT012 (strain 630) and RT017 (strains M68 and CF5)] and IEC cell-lines were investigated. All RTs showed significant engagement with human Toll-like receptors (TLR)-5, TLR2-CD14 and TLR2/6 as measured by IL-8 release from TLR-transfected HEK cells. Co-culture studies indicated minimal impact of R20291 and 630 TcdA and TcdB on bacterial adherence to Caco-2 cells. An apical anaerobic environment had a major effect on C. difficile-T84 crosstalk as significantly greater cytokine immunity and trans-epithelial electrical resistance (TEER) dysfunction was recorded when co-cultures were performed in an Ussing chamber system compared to standard 5% CO2 conditions. Overall, this study suggests that anaerobic C. difficile engagement with human IECs is a complex interplay that involves bacterial and toxin-mediated cellular events.

      PubDate: 2015-12-20T13:05:47Z
  • Sentinel Community Clostridium difficile infection (CDI) Surveillance in
           Scotland, April 2013 to March 2014
    • Abstract: Publication date: Available online 18 December 2015
      Author(s): A-Lan Banks, Derek J. Brown, Henry Mather, John E. Coia, Camilla Wiuff
      Surveillance of Clostridium difficile infection (CDI) in Scotland does not currently distinguish between CDI cases from hospitals and the community. Therefore, the incidence of CDI in the community is unknown, and the burden of disease and the relationship with the hospital/healthcare setting is not well understood. A one-year sentinel community surveillance programme was initiated in collaboration with five Scottish health boards (representing 36% of all CDI cases reported in Scotland) in 2013. Inclusion criteria were all cases aged ≥15 years with a CDI diagnosis in the community or within 48 h following admission to hospital. CDI cases were categorised according to definitions used by the European Centre for Disease Prevention and Control. 256 CDI cases met the inclusion criteria, of which 158 (62%) were community-associated cases (CA-CDI). This represented 26% of all cases reported during the surveillance period by the participating health boards (n=614). The overall CA-CDI incidence rate was 9.9 per 100 000 population per year. CA-CDI cases were more likely to be female and younger, compared to hospital acquired cases (HA-CDI). The total proportion of cases that had onset in the community was 27%. Ribotypes 015, 002, 078 and 005 were the most common types isolated from both CA-CDI and HA-CDI cases. There were no statistically significant differences between the proportion of types that were either CA-CDI or HA-CDI. Of the CA-CDI cases, 37% had not received antibiotics in the 12 weeks preceding CDI diagnosis, 4% were resident in care homes, and the case-fatality rate for CA-CDI cases was 5.6% (with a 30-day mortality rate for CA-CDI of 0.44 per 100 000 population per year). This study has shown that a substantial proportion of CDI cases reported in Scotland are community associated and that there are close links between the community and healthcare settings. It is therefore essential to monitor the trends in CDI in the community at a national level. The study also provides evidence for the need to examine the feasibility for development of interventions to reduce the burden in the community in addition to hospitals.

      PubDate: 2015-12-20T13:05:47Z
  • Spectrum of Clostridium difficile infections: Particular clinical
    • Abstract: Publication date: Available online 15 December 2015
      Author(s): Emilio Bouza, Marcela González Del Vecchio, Elena Reigadas
      Incidence, pathogenesis, diagnostic techniques and therapeutic management of CDI have prompted abundant and adequate recent literature. However, report on clinical manifestations of CDI is frequently biased by the type of patients selected, the retrospective nature of many papers, the epidemic or endemic characteristics of the population reported. This article seeks to review some less discussed clinical and epidemiological aspects of CDI trying to include the clinical manifestations of this disease in unselected populations and also including discussion of CDI in specific groups of patients such as patients without colon and rectum, pediatric and critical care patients.

      PubDate: 2015-12-16T12:47:41Z
  • Susceptibility of Clostridium difficile to the food preservatives sodium
           nitrite, sodium nitrate and sodium metabisulphite
    • Abstract: Publication date: Available online 15 December 2015
      Author(s): Su-Chen Lim, Niki F. Foster, Thomas V. Riley
      Clostridium difficile is an important enteric pathogen of humans and food animals. Recently it has been isolated from retail foods with prevalences up to 42%, prompting concern that contaminated foods may be one of the reasons for increased community-acquired C. difficile infection (CA-CDI). A number of studies have examined the prevalence of C. difficile in raw meats and fresh vegetables; however, fewer studies have examined the prevalence of C. difficile in ready-to-eat meat. The aim of this study was to investigate the in vitro susceptibility of 11 C. difficile isolates of food animal and retail food origins to food preservatives commonly used in ready-to-eat meats. The broth microdilution method was used to determine the minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) for sodium nitrite, sodium nitrate and sodium metabisulphite against C. difficile. Checkerboard assays were used to investigate the combined effect of sodium nitrite and sodium nitrate, commonly used in combination in meats. Modal MIC values for sodium nitrite, sodium nitrate and sodium metabisulphite were 250 μg/ml, >4000 μg/ml and 1000 μg/ml, respectively. No bactericidal activity was observed for all three food preservatives. The checkerboard assays showed indifferent interaction between sodium nitrite and sodium nitrate. This study demonstrated that C. difficile can survive in the presence of food preservatives at concentrations higher than the current maximum permitted levels allowed in ready-to-eat meats. The possibility of retail ready-to-eat meats contaminated with C. difficile acting as a source of CDI needs to be investigated.

      PubDate: 2015-12-16T12:47:41Z
  • Metagenomic assessment of the functional potential of the rumen microbiome
           in Holstein dairy cows
    • Abstract: Publication date: Available online 15 December 2015
      Author(s): Dipti W. Pitta, Nagaraju Indugu, Sanjay Kumar, Bonnie Vecchiarelli, Rohini Sinha, Linda D. Baker, Bhima Bhukya, James D. Ferguson
      The microbial ecology of the rumen microbiome is influenced by the diet and the physiological status of the dairy cow and can have tremendous influence on the yield and components of milk. There are significant differences in milk yields between first and subsequent lactations of dairy cows, but information on how the rumen microbiome changes as the dairy cow gets older has received little attention. We characterized the rumen microbiome of the dairy cow for phylogeny and functional pathways by lactation group and stage of lactation using a metagenomics approach. Our findings revealed that the rumen microbiome was dominated by Bacteroidetes (70%), Firmicutes (15-20%) and Proteobacteria (7%). The abundance of Firmicutes and Proteobacteria were independently influenced by diet and lactation. Bacteroidetes contributed to a majority of the metabolic functions in first lactation dairy cows while the contribution from Firmicutes and Proteobacteria increased incrementally in second and third lactation dairy cows. We found that nearly 70% of the CAZymes were oligosaccharide breaking enzymes which reflect the higher starch and fermentable sugars in the diet. The results of this study suggest that the rumen microbiome continues to evolve as the dairy cow advances in lactations and these changes may have a significant role in milk production.

      PubDate: 2015-12-16T12:47:41Z
  • Early diagnosis and treatment in a child with foodborne botulism
    • Abstract: Publication date: Available online 11 December 2015
      Author(s): Maria Renata Proverbio, Marta Lamba, Alessandro Rossi, Paolo Siani
      Introduction Foodborne botulism is a neuroparalytic disease caused by ingestion of food contaminated with botulinum toxins. Despite rare the mortality rate is high if untreated. Diagnosis of botulism is still a challenge for clinician, due to the variability of clinical manifestations and disease course. We report on a child with type B botulin intoxication who was early diagnosed and; treated underlining that clinical suspicion is crucial to start prompt treatment. Case presentation An 11-year-old boy presented with bilateral ptosis and mydriasis, dry mouth, difficulty in swallowing, dysphonia, urine retention and constipation. Clear sensorium and no fever were observed. Immediately the suspicion of botulism was risen and botulinum antitoxin was administered. 3 days later serum and rectal samples tested positive for C. botulinum. The patient completely recovered when discharged from hospital. Discussion Foodborne botulism is still possible in developed countries. The confirmation test of botulism requires some days. To avoid long delays between intoxication and diagnosis prompt clinical suspicion is thus crucial. The outcome depends on rapid implementation of appropriate management with intensive respiratory care and antitoxin administration.

      PubDate: 2015-12-12T12:26:45Z
  • Immunogenicity and Protective Efficacy of Clostridium difficile Spore
    • Abstract: Publication date: Available online 11 December 2015
      Author(s): Chandrabali Ghose, Ioannis Eugenis, Adrianne N. Edwards, Xingmin Sun, Shonna M. McBride, David D. Ho
      Clostridium difficile is a spore-forming, anaerobic, Gram-positive organism that is the leading cause of antibiotic-associated infectious diarrhea, commonly known as C. difficile infection (CDI). C. difficile spores play an important role in the pathogenesis of CDI. Spore proteins, especially those that are surface-bound may play an essential role in the germination, colonization and persistence of C. difficile in the human gut. In our current study, we report the identification of two surface-bound spore proteins, CdeC and CdeM that may be utilized as immunization candidates against C. difficile. These spore proteins are immunogenic in mice and are able to protect mice against challenge with C. difficile UK1, a clinically-relevant 027/B1/NAP1 strain. These spore proteins are also able to afford high levels of protection against challenge with C. difficile 630Δerm in golden Syrian hamsters. This unprecedented study shows the vaccination potential of C. difficile spore exosporium proteins.

      PubDate: 2015-12-12T12:26:45Z
  • Persistence of Clostridium difficile RT 237 infection in a Western
           Australian piggery
    • Abstract: Publication date: Available online 8 December 2015
      Author(s): Peter Moono, Papanin Putsathit, Daniel R. Knight, Michele M. Squire, David J. Hampson, Niki F. Foster, Thomas V. Riley
      Clostridium difficile is commonly associated with healthcare-related infections in humans, and is an emerging pathogen in food animal species. There is potential for transmission of C. difficile from animals or animal products to humans. This study aimed to determine if C. difficile RT 237 had persisted in a Western Australian piggery or if there had been a temporal change in C. difficile diversity. C. difficile carriage in litters with and without diarrhea was investigated, as was the acquisition of C. difficile over time using cohort surveys. Rectal swabs were obtained from piglets aged 1-10 days to determine prevalence of C. difficile carriage and samples were obtained from 20 piglets on days 1, 7, 13, 20, and 42 of life to determine duration of shedding. Isolation of C. difficile from feces was achieved by selective enrichment culture. All isolates were characterized by standard molecular typing. Antimicrobial susceptibility testing was performed on selected isolates (n=29). Diarrheic piglets were more likely to shed C. difficile than the non-diseased (p=0.0124, χ2). In the cohort study, C. difficile was isolated from 40% samples on day 1, 50% on day 7, 20% on day 13, and 0% on days 20 and 42. All isolates were RT 237 and no antimicrobial resistance was detected. The decline of shedding of C. difficile to zero has public health implications because slaughter age pigs have a low likelihood of spreading C. difficile to consumers via pig meat.

      PubDate: 2015-12-12T12:26:45Z
  • Diversity of Clostridium perfringens isolates from various sources and
           prevalence of conjugative plasmids
    • Abstract: Publication date: April 2016
      Source:Anaerobe, Volume 38
      Author(s): Miseon Park, Joanna Deck, Steven L. Foley, Rajesh Nayak, J. Glenn Songer, Janice R. Seibel, Saeed A. Khan, Alejandro P. Rooney, David W. Hecht, Fatemeh Rafii
      Clostridium perfringens is an important pathogen, causing food poisoning and other mild to severe infections in humans and animals. Some strains of C. perfringens contain conjugative plasmids, which may carry antimicrobial resistance and toxin genes. We studied genomic and plasmid diversity of 145 C. perfringens type A strains isolated from soils, foods, chickens, clinical samples, and domestic animals (porcine, bovine and canine), from different geographic areas in the United States between 1994 and 2006, using multiple-locus variable-number tandem repeat analysis (MLVA) and/or pulsed-field gel electrophoresis (PFGE). MLVA detected the genetic diversity in a majority of the isolates. PFGE, using SmaI and KspI, confirmed the MLVA results but also detected differences among the strains that could not be differentiated by MLVA. All of the PFGE profiles of the strains were different, except for a few of the epidemiologically related strains, which were identical. The PFGE profiles of strains isolated from the same domestic animal species were clustered more closely with each other than with other strains. However, a variety of C. perfringens strains with distinct genetic backgrounds were found among the clinical isolates. Variation was also observed in the size and number of plasmids in the strains. Primers for the internal fragment of a conjugative tcpH gene of C. perfringens plasmid pCPF4969 amplified identical size fragments from a majority of strains tested; and this gene hybridized to the various-sized plasmids of these strains. The sequences of the PCR-amplified tcpH genes from 12 strains showed diversity among the tcpH genes. Regardless of the sources of the isolates, the genetic diversity of C. perfringens extended to the plasmids carrying conjugative genes.

      PubDate: 2015-12-03T08:37:45Z
  • A case of bacteremia caused by Dialister pneumosintes and Slackia exigua
           in a patient with periapical abscess
    • Abstract: Publication date: April 2016
      Source:Anaerobe, Volume 38
      Author(s): Min Young Lee, Young Jin Kim, Hyun Jung Gu, Hee Joo Lee
      Dialister pneumosintes and Slackia exigua are both obligatory anaerobe and known to be associated with periodontal diseases and other oral infection. We report a case of blood stream infection caused by D. pneumosintes and S. exigua. This occurred in a 78-year-old female patient that presented with general weakness and fever. We revealed that she had a periapical absecess. The blood culture was positive for D. pneumosintes and S. exigua; however, identifying them was challenging. Ultimately, 16S rRNA sequencing was used to identify the organisms. The patient recovered after being treated with ceftriaxone and clindamycin. To the best of our knowledge, this is the first report of bacteremia caused by mixed infection of D. pneumosintes and S. exigua.

      PubDate: 2015-12-03T08:37:45Z
  • Microbial colonization of normal skin: direct visualization of 194 skin
    • Abstract: Publication date: Available online 2 December 2015
      Author(s): Anika C. Jahns, Oleg A. Alexeyev
      Recent genetic studies have suggested the presence of numerous microbial species on and in the skin. We characterised microbial colonization of a large collection of skin biopsies from 194 healthy subjects by fluorescence assay. Forty per cent of all biopsies did not show any evidence for microbial colonization. Propionibacterium acnes was the sole predominant bacterial species in both sebaceous and non-sebaceous areas. Non- P. acnes species were present in 20% of all biopsies. Only hair follicles and stratum corneum were colonized. Understanding of cutaneous microbiota requires validation from a variety of approaches and techniques.

      PubDate: 2015-12-03T08:37:45Z
  • Robust and effective methodologies for cryopreservation and DNA extraction
           from anaerobic gut fungi
    • Abstract: Publication date: Available online 24 November 2015
      Author(s): Kevin V. Solomon, John K. Henske, Michael K. Theodorou, Michelle A. O’Malley
      Cell storage and DNA isolation are essential to developing an expanded suite of microorganisms for biotechnology. However, many features of non-model microbes, such as an anaerobic lifestyle and rigid cell wall, present formidable challenges to creating strain repositories and extracting high quality genomic DNA. Here, we establish accessible, high efficiency, and robust techniques to store lignocellulolytic anaerobic gut fungi long term without specialized equipment. Using glycerol as a cryoprotectant, gut fungal isolates were preserved for a minimum of 23 months at -80°C. Unlike previously reported approaches, this improved protocol is non-toxic and rapid, with samples surviving twice as long with negligible growth impact. Genomic DNA extraction for these isolates was optimized to yield samples compatible with next generation sequencing platforms (e.g. Illumina, PacBio). Popular DNA isolation kits and precipitation protocols yielded preps that were unsuitable for sequencing due to carbohydrate contaminants from the chitin-rich cell wall and extensive energy reserves of gut fungi. To address this, we identified a proprietary method optimized for hardy plant samples that rapidly yielded DNA fragments in excess of 10 kb with minimal RNA, protein or carbohydrate contamination. Collectively, these techniques serve as fundamental tools to manipulate powerful biomass-degrading gut fungi and improve their accessibility among researchers.

      PubDate: 2015-11-29T08:26:10Z
  • Clostridium difficile carriage in healthy pregnant women in China
    • Abstract: Publication date: Available online 26 November 2015
      Author(s): Guang-yong Ye, Na Li, Yun-Bo Chen, Tao Lv, Ping Shen, Si-Lan Gu, Yun-hui Fang, Lan-Juan Li
      Infection with Clostridium difficile has been shown to have particularly poor outcomes for pregnant women, including an increased risk of death. The purpose of this study was to investigate the prevalence, genotypic distribution, and characterization of Clostridium difficile strains isolated from pregnant women without diarrhea in China. As part of this study, 3.7% (37 out of 1,009) of samples acquired from pregnant females tested positive for C. difficile. Of these positive samples, 27.0% (10) were toxigenic isolates containing both toxin A and toxin B genes (A+B+), 13.5% (5) of the variant strains contained the toxin B gene (A-B+) only, while the rest were non-toxigenic isolates (59.5%, 22 isolates). Among the non-pregnant women without diarrhea tested, 1.4% (9 of 651) contained toxigenic isolates (all of which were A+B+). Sixteen different sequence types (STs) were isolated during the course of this study. ST-37 (ribotype 017) and ST-54 (ribotype 012) were the most frequent toxigenic types observed in pregnant women. All strains showed susceptibility to the antibiotics metronidazole and vancomycin. The resistance rates of toxigenic C. difficile strains isolated from pregnant females to clindamycin, erythromycin, moxifloxacin, levofloxacin, and rifampicin were 20%, 46.7%, 13.6%, 46.7% and 13.3%, respectively. There was no significant difference between resistance rates of toxigenic and non-toxigenic strains with respect to their susceptibility to these antibiotics. However, when compared with the same data from non-pregnant women, toxigenic strains from pregnant women showed lower resistance rates to clindamycin (P < 0.05).

      PubDate: 2015-11-29T08:26:10Z
  • Editorial board
    • Abstract: Publication date: December 2015
      Source:Anaerobe, Volume 36

      PubDate: 2015-11-29T08:26:10Z
  • Routine detection of Clostridium difficile in Western Australia
    • Abstract: Publication date: Available online 22 November 2015
      Author(s): Deirdre A. Collins, Thomas V. Riley
      Despite increasing infection rates, Clostridium difficile is not currently routinely tested for in all diarrhoeal faecal specimens in Australia. In July 2014, all diarrhoeal specimens submitted to a diagnostic laboratory in Western Australia were surveyed to determine the true prevalence of C. difficile. In total, 1010 diarrhoeal non-duplicate faecal specimens were received during the month. Testing for C. difficile was requested, or the criteria for a C. difficile investigation were met, for 678 specimens which were investigated by PCR for the tcdB gene using the BD MAX platform, followed by toxigenic culture on PCR positive samples. The remaining 332 specimens, with either no C. difficile test request or the criteria for a C. difficile investigation were not met, were examined by toxigenic culture. All isolates were PCR ribotyped. C. difficile was the most commonly detected diarrhoeal pathogen among all specimens. The overall prevalence of C. difficile in all 1010 specimens was 6.4%; 7.2% in the routinely tested group, and 4.8% in the non-requested group. The proportion of non-requested positive detections among all cases was 24.6%. Community-onset infection was present in 50.8% of all cases. The median age of all CDI cases was 60.0 years and the age range in CDI patients in the routine group was 0.6-96.6 years (median 72.7 years), compared to 0.2-2.3 years (median 0.8 years) in the non-requested group. The most common ribotype (RT) found was RT 014/020 (34.1% in the routine group, 43.8% in the non-requested group), followed by RTs 002, 056, 005 and 018. While the routine testing group and the non-requested group differed markedly in age and patient classification, C. difficile was the most common cause of diarrhoea in hospitals and the community in Western Australia. The significance of finding C. difficile in the community paediatric population requires further study.

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

      PubDate: 2015-11-24T23:24:19Z
  • Comparison of vaginal microbial community structure in healthy and
           endometritis dairy cows by PCR-DGGE and Real-time PCR
    • Abstract: Publication date: Available online 10 November 2015
      Author(s): Jun Wang, Chengtao Sun, Chang Liu, Yujiang Yang, Wenfa Lu
      The normal vaginal microflora provides protection against infections of the reproductive tract. Previous studies have focused on the isolation and screening of probiotic strains from the vagina of cows; however, the vaginal microflora of postpartum cows is poorly characterized. The present study was conducted to evaluate and characterize the vaginal microflora of healthy postpartum cows in relation to postpartum cows with endometritis by using PCR followed by denaturing gradient gel electrophoresis (PCR-DGGE) and Real-time PCR. The study population comprised 5 healthy cows and 5 cows with endometritis. The results indicated that the vaginal bacterial microflora of healthy postpartum cows was dominated by Lactobacillus sakei subsp. and Weissella koreensis, while there were no dominant bacterial species in the vaginal microflora of postpartum cows with endometritis. Common microorganisms such as Bacteroides spp., Fusobacterium spp., Enterococcus spp., Prevotella spp., Clostridium perfringens strains, and Escherichia coli were detected in both groups of cows by Real-time PCR. The bacterial diversity in the vagina of cows with endometritis was significantly higher than that in healthy cows. The results indicated that the vaginal microflora of cows with endometritis was more diverse and lacked dominant bacterial species as compared to that of the healthy cows, suggesting that disruption of the normal vaginal microflora may contribute to the onset of endometritis. This microbial community analysis provided information that might be used to develop probiotics to treat endometritis in cows; however, further investigation is needed.

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

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

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

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

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

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

      PubDate: 2015-11-01T08:30:15Z
  • BV and non-BV associated Gardnerella vaginalis establish similar
           synergistic interactions with other BV-associated microorganism in
           dual-species biofilms
    • Abstract: Publication date: Available online 24 October 2015
      Author(s): Joana Castro, Nuno Cerca
      Dual-species biofilm formation between Gardnerella vaginalis strains isolated from women with or without bacterial vaginosis (BV) and other 24 BV-associated microorganisms support that the key difference in virulence potential between BV-negative and BV-positive G. vaginalis strains seems not to be related with biofilm maturation.

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

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

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

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

      PubDate: 2015-10-24T07:48:54Z
  • Improvement of the butanol production selectivity and butanol to acetone
           ratio (B:A) by addition of electron carriers in the batch culture of a new
           local isolate of Clostridium acetobutylicum YM1
    • Abstract: Publication date: Available online 9 October 2015
      Author(s): Najeeb Kaid Nasser Al-Shorgani, Mohd Sahaid Kalil, Wan Mohtar Wan Yusoff, Chowdhury Mohammad Monirul Hasan, Aidil Abdul Hamid
      Improvement in the butanol production selectivity or enhanced butanol: acetone ratio (B:A) is desirable in acetone-butanol-ethanol (ABE) fermentation by Clostridium strains. In this study, artificial electron carriers were added to the fermentation medium of a new isolate of Clostridium acetobutylicum YM1 in order to improve the butanol yield and B:A ratio. The results revealed that medium supplementation with electron carriers changed the metabolism flux of electron and carbon in ABE fermentation by YM1. A decrease in acetone production, which subsequently improved the B:A ratio, was observed. Further improvement in the butanol production and B:A ratios were obtained when the fermentation medium was supplemented with butyric acid. The maximum butanol production (18.20±1.38 g/L) was gained when a combination of methyl red and butyric acid was added. Although the addition of benzyl viologen (0.1 mM) and butyric acid resulted in high a B:A ratio of 16:1 (800% increment compared with the conventional 2:1 ratio), the addition of benzyl viologen to the culture after 4 h resulted in the production of 18.05 g/L butanol. Manipulating the metabolic flux to butanol through the addition of electron carriers could become an alternative strategy to achieve higher butanol productivity and improve the B:A ratio.

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

      PubDate: 2015-10-11T17:00:45Z
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