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https://www.readbyqxmd.com/read/28800585/comparative-pathogenomics-of-clostridium-tetani
#1
Jonathan E Cohen, Rong Wang, Rong-Fong Shen, Wells W Wu, James E Keller
Clostridium tetani and Clostridium botulinum produce two of the most potent neurotoxins known, tetanus neurotoxin and botulinum neurotoxin, respectively. Extensive biochemical and genetic investigation has been devoted to identifying and characterizing various C. botulinum strains. Less effort has been focused on studying C. tetani likely because recently sequenced strains of C. tetani show much less genetic diversity than C. botulinum strains and because widespread vaccination efforts have reduced the public health threat from tetanus...
2017: PloS One
https://www.readbyqxmd.com/read/28799283/selection-and-transfer-of-an-inci1-tet-a-plasmid-of-escherichia-coli-in-an-ex-vivo-model-of-the-porcine-cecum-at-doxycycline-concentrations-caused-by-cross-contaminated-feed
#2
Laura E J Peeters, Thijs De Mulder, Els Van Coillie, Judith Huygens, Annemieke Smet, Els Daeseleire, Jeroen Dewulf, Hein Imberechts, Patrick Butaye, Freddy Haesebrouck, Siska Croubels, Marc Heyndrickx, Geertrui Rasschaert
AIMS: The aim of this study was to investigate the effect of subtherapeutic intestinal doxycycline (DOX) concentrations (4 and 1 mg l(-1) ), caused by cross-contamination of feed, on the enrichment of a DOX resistant commensal E. coli and it's resistance plasmid in an ex vivo model of the porcine cecum. METHODS AND RESULTS: A DOX resistant, tet(A) carrying, porcine commensal E. coli strain (EC 682) was cultivated for 6 days in the porcine cecum model under different conditions (0, 1 and 4 mg l(-1) DOX)...
August 11, 2017: Journal of Applied Microbiology
https://www.readbyqxmd.com/read/28798374/culture-independent-assessment-of-human-milk-microbial-community-in-lactational-mastitis
#3
Shriram H Patel, Yati H Vaidya, Reena J Patel, Ramesh J Pandit, Chaitanya G Joshi, Anju P Kunjadiya
Breastfeeding undoubtedly provides important benefits to the mother-infant dyad and should be encouraged. Mastitis, one of the common but major cause of premature weaning among lactating women, is an inflammation of connective tissue within the mammary gland. This study reports the influence of mastitis on human milk microbiota by utilizing 16 S rRNA gene sequencing approach. We sampled and sequenced microbiome from 50 human milk samples, including 16 subacute mastitis (SAM), 16 acute mastitis (AM) and 18 healthy-controls...
August 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28795339/impact-of-nasopharyngeal-microbiota-on-the-development-of-respiratory-tract-diseases
#4
REVIEW
S Esposito, N Principi
Knowledge of whether and how respiratory microbiota composition can prime the immune system and provide colonisation resistance, limiting consecutive pathobiont overgrowth and infections, is essential to improving the prevention and therapy of respiratory disorders. Modulation of dysbiotic ecosystems or reconstitution of missing microbes might be a possible measure to reduce respiratory diseases. The aim of this review is to analyse the role of nasopharyngeal microbiota in the development of respiratory tract disease in paediatric-age subjects...
August 9, 2017: European Journal of Clinical Microbiology & Infectious Diseases
https://www.readbyqxmd.com/read/28795125/the-microbiome-activates-cd4-t-cell-mediated-immunity-to%C3%A2-compensate-for-increased-intestinal-permeability
#5
Karen L Edelblum, Gil Sharon, Gurminder Singh, Matthew A Odenwald, Anne Sailer, Severine Cao, Sarina Ravens, Irene Thomsen, Kamal El Bissati, Rima McLeod, Chen Dong, Sandeep Gurbuxani, Immo Prinz, Sarkis K Mazmanian, Jerrold R Turner
BACKGROUND & AIMS: Despite a prominent association, chronic intestinal barrier loss is insufficient to induce disease in human subjects or experimental animals. We hypothesized that compensatory mucosal immune activation might protect individuals with increased intestinal permeability from disease. We used a model in which intestinal barrier loss is triggered by intestinal epithelial-specific expression of constitutively active myosin light chain kinase (CA-MLCK). Here we asked whether constitutive tight junction barrier loss impacts susceptibility to enteric pathogens...
September 2017: Cellular and Molecular Gastroenterology and Hepatology
https://www.readbyqxmd.com/read/28793322/stool-consistency-is-significantly-associated-with-pain-perception
#6
Yukiko Shiro, Young-Chang Arai, Tatsunori Ikemoto, Kazuhiro Hayashi
BACKGROUND: Commensal as well as pathogenic bacteria can influence a variety of gut functions, thereby leading to constipation and diarrhea in severe cases. In fact, several researchers have reported evidence supporting the association between stool consistency or constipation and the Gut microbiome (GM) composition and dysbiosis. GM influences the human health and disease via the gut-brain axis. We thus hypothesized that the pathogenic bacteria increases pain perception to some extent, which means that there could be an association between stool consistency or constipation and pain perception of healthy subjects...
2017: PloS One
https://www.readbyqxmd.com/read/28793252/human-gut-derived-commensal-bacteria-suppress-cns-inflammatory-and-demyelinating-disease
#7
Ashutosh Mangalam, Shailesh K Shahi, David Luckey, Melissa Karau, Eric Marietta, Ningling Luo, Rok Seon Choung, Josephine Ju, Ramakrishna Sompallae, Katherine Gibson-Corley, Robin Patel, Moses Rodriguez, Chella David, Veena Taneja, Joseph Murray
The human gut is colonized by a large number of microorganisms (∼10(13) bacteria) that support various physiologic functions. A perturbation in the healthy gut microbiome might lead to the development of inflammatory diseases, such as multiple sclerosis (MS). Therefore, gut commensals might provide promising therapeutic options for treating MS and other diseases. We report the identification of human gut-derived commensal bacteria, Prevotella histicola, which can suppress experimental autoimmune encephalomyelitis (EAE) in a human leukocyte antigen (HLA) class II transgenic mouse model...
August 8, 2017: Cell Reports
https://www.readbyqxmd.com/read/28790997/tetracycline-resistance-genes-identified-from-distinct-soil-environments-in-china-by-functional-metagenomics
#8
Shaochen Wang, Xia Gao, Yuejiao Gao, Yanqing Li, Mingming Cao, Zhenhua Xi, Lixing Zhao, Zhiyang Feng
Soil microbiota represents one of the ancient evolutionary origins of antibiotic resistance and has been increasingly recognized as a potentially vast unstudied reservoir of resistance genes with possibilities to exchange with pathogens. Tetracycline resistance is one of the most abundant antibiotic resistances that may transfer among clinical and commensal microorganisms. To investigate tetracycline resistance genes from soil bacteria in different habitats, we performed functional analysis of three metagenomic libraries derived from soil samples collected from Yunnan, Sichuan, and Tibet, respectively, in China...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28783566/autoclaved-sludge-as-the-ideal-seed-to-culture-anammox-bacteria-reactor-performance-and-microbial-community-diversity
#9
Yu Wang, Cui-Na Bu, Qi Kang, Hafiz Adeel Ahmad, Jian Zhang, Baoyu Gao, Shou-Qing Ni
Reducing activity of commensal bacteria in inocula may enhance anammox bacteria proliferation and realization of anammox process. Fast start-up of anammox process in an UASB reactor was successfully achieved by using autoclaved sludge (anaerobic granular sludge pretreated by autoclaving) and 0.3% active anammox sludge as inoculum. Continuous experiments indicated that R2 (autoclaved sludge addition) could shorten the start-up period from 72days to 63days. The first 50days anammox population specific growth rates (μ) of R1 (the control) and R2 were determined to be 0...
July 29, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28782508/circulating-and-tissue-resident-cd4-t-cells-with-reactivity-to-intestinal-microbiota-are-abundant-in-healthy-individuals-and-function-is-altered-during-inflammation
#10
Ahmed N Hegazy, Nathaniel R West, Michael J T Stubbington, Emily Wendt, Kim I M Suijker, Angeliki Datsi, Sebastien This, Camille Danne, Suzanne Campion, Sylvia H Duncan, Benjamin M J Owens, Holm H Uhlig, Andrew McMichael, Andreas Bergthaler, Sarah A Teichmann, Satish Keshav, Fiona Powrie
BACKGROUND & AIMS: Interactions between commensal microbes and the immune system are tightly regulated and maintain intestinal homeostasis, but little is known about these interactions in humans. We investigated responses of human CD4(+) T cells to the intestinal microbiota. We measured the abundance of T cells in circulation and intestinal tissues that respond to intestinal microbes and determined their clonal diversity. We also assessed their functional phenotypes and effects on intestinal resident cell populations, and studied alterations in microbe-reactive T cells in patients with chronic intestinal inflammation...
August 3, 2017: Gastroenterology
https://www.readbyqxmd.com/read/28782479/candida-infections-and-human-defensins
#11
Vania Polesello, Ludovica Segat, Sergio Crovella, Luisa Zupin
Candida species infections are an important worldwide health issue since they do not only affect immunocompromised patients but also healthy individuals. Indeed Candida spp. are present as commensal flora in the host human body but they can switch into a pathological form inducing cellular damage and disease. Among Candida strains, C. albicans is the most prevalent in both mucosal and systemic infections. The host developed different mechanisms of protection against Candida infections; specifically the immune system and the innate immune response are the first line of defence...
August 7, 2017: Protein and Peptide Letters
https://www.readbyqxmd.com/read/28776953/establishment-of-oral-bacterial-communities-in-germ-free-mice-and-the-influence-of-recipient-age
#12
Yingying Wu, Caroline Westwater, E Xiao, Jôice Dias Corrêa, Wenmei Xiao, Dana T Graves
The acquisition of the oral microbiome is a complex process. We examined how the timing of microbial exposure alters bacterial colonization of the tooth surface. Germ-free mice were conventionalized by exposure to specific pathogen free (SPF) mice to acquire a commensal microbiome over three distinct four week periods, 0-4 weeks of age (Conv0-4w), 4-8 weeks (Conv4-8w), or 8-12 weeks (Conv8-12w). Bacterial DNA was extracted from the tooth surface and analyzed by 16S rDNA sequencing. Total bacteria and inflammatory cytokine expression in gingiva were determined by quantitative real-time PCR...
August 4, 2017: Molecular Oral Microbiology
https://www.readbyqxmd.com/read/28775282/ecological-effect-of-arginine-on-oral-microbiota
#13
Xin Zheng, Jinzhi He, Lin Wang, Shuangshuang Zhou, Xian Peng, Shi Huang, Liwei Zheng, Lei Cheng, Yuqing Hao, Jiyao Li, Jian Xu, Xin Xu, Xuedong Zhou
Dental caries is closely associated with the microbial dybiosis between acidogenic/aciduric pathogens and alkali-generating commensal bacteria colonized in the oral cavity. Our recent studies have shown that arginine may represent a promising anti-caries agent by modulating microbial composition in an in vitro consortium. However, the effect of arginine on the oral microbiota has yet to be comprehensively delineated in either clinical cohort or in vitro biofilm models that better represent the microbial diversity of oral cavity...
August 3, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28774470/history-and-mechanisms-of-oral-tolerance
#14
REVIEW
Rafael M Rezende, Howard L Weiner
Since its first description by Wells and Osbourne in 1911, oral tolerance has intrigued researchers due to its potential for therapeutic applications. Oral tolerance can be defined as an inhibition of specific immune responsiveness to subsequent parenteral injections of proteins to which an individual or animal has been previously exposed via the oral route. Tolerance induction to commensal bacteria and dietary proteins represents the major immunological event taking place in the gut in physiological conditions...
July 31, 2017: Seminars in Immunology
https://www.readbyqxmd.com/read/28771951/microbial-approaches-for-targeting-antibiotic-resistant-bacteria
#15
REVIEW
Wing Fei Wong, Marina Santiago
Antibiotic resistant bacterial infections are a global public health challenge that has been increasing in severity and scope for the last few decades. Without creative solutions to this problem, treatment of injuries and infections will become progressively more challenging. A better understanding of the human microbiome has led to a new appreciation for the role commensal microbes play in protecting us from pathogens, especially in the gut. Antibiotics lead to disruption of the gut microbial ecosystem, enabling colonization by antibiotic resistant bacterial pathogens...
August 3, 2017: Microbial Biotechnology
https://www.readbyqxmd.com/read/28770665/immunopathophysiology-of-inflammatory-bowel-disease-how-genetics-link-barrier-dysfunction-and-innate-immunity-to-inflammation
#16
Minesh Mehta, Shifat Ahmed, Gerald Dryden
Inflammatory bowel diseases (IBD) comprise a distinct set of clinical symptoms resulting from chronic or relapsing immune activation and corresponding inflammation within the gastrointestinal (GI) tract. Diverse genetic mutations, encoding important aspects of innate immunity and mucosal homeostasis, combine with environmental triggers to create inappropriate, sustained inflammatory responses. Recently, significant advances have been made in understanding the interplay of the intestinal epithelium, mucosal immune system, and commensal bacteria as a foundation of the pathogenesis of inflammatory bowel disease...
August 2017: Innate Immunity
https://www.readbyqxmd.com/read/28769037/mechanism-of-biofilm-mediated-stress-resistance-and-lifespan-extension-in-c-elegans
#17
Olga Smolentseva, Ivan Gusarov, Laurent Gautier, Ilya Shamovsky, Alicia S DeFrancesco, Richard Losick, Evgeny Nudler
Bacteria naturally form communities of cells known as biofilms. However the physiological roles of biofilms produced by non-pathogenic microbiota remain largely unknown. To assess the impact of a biofilm on host physiology we explored the effect of several non-pathogenic biofilm-forming bacteria on Caenorhabditis elegans. We show that biofilm formation by Bacillus subtilis, Lactobacillus rhamnosus and Pseudomonas fluorescens induces C. elegans stress resistance. Biofilm also protects against pathogenic infection and prolongs lifespan...
August 2, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28766918/the-skin-microbiome-and-immune-system-potential-target-for-chemoprevention
#18
REVIEW
Mohammad Asif Sherwani, Saba Tufail, Anum Fatima Muzaffar, Nabiha Yusuf
There has been increasing interest in understanding the role of the human microbiome in skin diseases. Microbiome studies are being utilized in skin cancer research in numerous ways. Commensal bacteria are being studied as a potential tool to judge the biggest environmental risk of skin cancer, ultraviolet (UV) radiation. Owing to the recognized link of skin microbes in the process of inflammation, there have been theories linking commensal bacteria to skin cancer. Viral metagenomics has also provided insight into virus linked forms of skin cancers...
August 2, 2017: Photodermatology, Photoimmunology & Photomedicine
https://www.readbyqxmd.com/read/28766556/antigen-specific-regulatory-t-cell-responses-to-intestinal-microbiota
#19
REVIEW
E V Russler-Germain, S Rengarajan, C-S Hsieh
The mammalian gastrointestinal tract can harbor both beneficial commensal bacteria important for host health, but also pathogenic bacteria capable of intestinal damage. It is therefore important that the host immune system mount the appropriate immune response to these divergent groups of bacteria-promoting tolerance in response to commensal bacteria and sterilizing immunity in response to pathogenic bacteria. Failure to induce tolerance to commensal bacteria may underlie immune-mediated diseases such as human inflammatory bowel disease...
August 2, 2017: Mucosal Immunology
https://www.readbyqxmd.com/read/28766043/intestinal-macrophages-in-peyer-s-patches-sacculus-rotundus-and-appendix-of-angora-rabbit
#20
Feyzullah Beyaz, Narin Liman, Emel Ergün, Levent Ergün, Mehmet Özbek
The largest pool of macrophages in the body is harboured by the intestinal mucosa. As the principal phagocytic component of the immune system, macrophages are essential for maintaining mucosal homeostasis as they prevent commensal bacteria from adhering to mucosal epithelial cells. This study provides a RAM11 immunohistochemical and electron microscopic investigation of the existence, localization and distribution of intestinal macrophages in organized gut-associated lymphoid tissue (GALT), including Peyer's patches (PPs), the sacculus rotundus (SR) and the appendix, in the Angora rabbit...
August 2, 2017: Cell and Tissue Research
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