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Harry J Fli - One of the best experts on this subject based on the ideXlab platform.
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acetate utilization and butyryl coenzyme a coa acetate coa transferase in butyrate Producing Bacteria from the human large intestine
Applied and Environmental Microbiology, 2002Co-Authors: Sylvia H Dunca, C S Stewa, Adela Arcenilla, Susa E Pryde, Harry J FliAbstract:Seven strains of Roseburia sp., Faecalibacterium prausnitzii, and Coprococcus sp. from the human gut that produce high levels of butyric acid in vitro were studied with respect to key butyrate pathway enzymes and fermentation patterns. Strains of Roseburia sp. and F. prausnitzii possessed butyryl coenzyme A (CoA):acetate-CoA transferase and acetate kinase activities, but butyrate kinase activity was not detectable either in growing or in stationary-phase cultures. Although unable to use acetate as a sole source of energy, these strains showed net utilization of acetate during growth on glucose. In contrast, Coprococcus sp. strain L2-50 is a net producer of acetate and possessed detectable butyrate kinase, acetate kinase, and butyryl-CoA:acetate-CoA transferase activities. These results demonstrate that different functionally distinct groups of butyrate-Producing Bacteria are present in the human large intestine.
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phylogenetic relationships of butyrate Producing Bacteria from the human gut
Applied and Environmental Microbiology, 2000Co-Authors: Adela Arcenilla, Sylvia H Dunca, C S Stewa, Susan E Pryde, Jennife C Marti, Coli Henderso, Harry J FliAbstract:Butyrate is a preferred energy source for colonic epithelial cells and is thought to play an important role in maintaining colonic health in humans. In order to investigate the diversity and stability of butyrate-Producing organisms of the colonic flora, anaerobic butyrate-Producing Bacteria were isolated from freshly voided human fecal samples from three healthy individuals: an infant, an adult omnivore, and an adult vegetarian. A second isolation was performed on the same three individuals 1 year later. Of a total of 313 Bacterial isolates, 74 produced more than 2 mM butyrate in vitro. Butyrate-Producing isolates were grouped by 16S ribosomal DNA (rDNA) PCR-restriction fragment length polymorphism analysis. The results indicate very little overlap between the predominant ribotypes of the three subjects; furthermore, the flora of each individual changed significantly between the two isolations. Complete sequences of 16S rDNAs were determined for 24 representative strains and subjected to phylogenetic analysis. Eighty percent of the butyrate-Producing isolates fell within the XIVa cluster of gram-positive Bacteria as defined by M. D. Collins et al. (Int. J. Syst. Bacteriol. 44:812–826, 1994) and A. Willems et al. (Int. J. Syst. Bacteriol. 46:195–199, 1996), with the most abundant group (10 of 24 or 42%) clustering with Eubacterium rectale , Eubacterium ramulus , and Roseburia cecicola . Fifty percent of the butyrate-Producing isolates were net acetate consumers during growth, suggesting that they employ the butyryl coenzyme A-acetyl coenzyme A transferase pathway for butyrate production. In contrast, only 1% of the 239 non-butyrate-Producing isolates consumed acetate.
Petra Louis - One of the best experts on this subject based on the ideXlab platform.
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diversity of human colonic butyrate Producing Bacteria revealed by analysis of the butyryl coa acetate coa transferase gene
Environmental Microbiology, 2010Co-Authors: Petra Louis, Pauline Young, Grietje HoltropAbstract:Butyrate-Producing Bacteria play an important role in the human colon, supplying energy to the gut epithelium and regulating host cell responses. In order to explore the diversity and culturability of this functional group, we designed degenerate primers to amplify butyryl-CoA:acetate CoA-transferase sequences from faecal samples provided by 10 healthy volunteers. Eighty-eight per cent of amplified sequences showed >98% DNA sequence identity to CoA-transferases from cultured butyrate-Producing Bacteria, and these fell into 12 operational taxonomic units (OTUs). The four most prevalent OTUs corresponded to Eubacterium rectale, Roseburia faecis, Eubacterium hallii and an unnamed cultured species SS2/1. The remaining 12% of sequences, however, belonged to 20 OTUs that are assumed to come from uncultured butyrate-Producing strains. Samples taken after ingestion of inulin showed significant (P=0.019) increases in Faecalibacterium prausnitzii. Because several of the dominant butyrate producers differ in their DNA % G+C content, analysis of thermal melt curves obtained for PCR amplicons of the butyryl-CoA:acetate CoA-transferase gene provides a convenient and rapid qualitative assessment of the major butyrate Producing groups present in a given sample. This type of analysis therefore provides an excellent source of information on functionally important groups within the colonic microbial community.
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diversity metabolism and microbial ecology of butyrate Producing Bacteria from the human large intestine
Fems Microbiology Letters, 2009Co-Authors: Petra LouisAbstract:Butyrate-Producing Bacteria play a key role in colonic health in humans. This review provides an overview of the current knowledge of the diversity, metabolism and microbial ecology of this functionally important group of Bacteria. Human colonic butyrate producers are Gram-positive firmicutes, but are phylogenetically diverse, with the two most abundant groups related to Eubacterium rectale/Roseburia spp. and to Faecalibacterium prausnitzii. Five different arrangements have been identified for the genes of the central pathway involved in butyrate synthesis, while in most cases butyryl-CoA : acetate CoA-transferase, rather than butyrate kinase, appears to perform the final step in butyrate synthesis. Mechanisms have been proposed recently in non-gut Clostridium spp. whereby butyrate synthesis can result in energy generation via both substrate-level phosphorylation and proton gradients. Here we suggest that these mechanisms also apply to the majority of butyrate producers from the human colon. The roles of these Bacteria in the gut community and their influence on health are now being uncovered, taking advantage of the availability of cultured isolates and molecular methodologies. Populations of F. prausnitzii are reported to be decreased in Crohn's disease, for example, while populations of Roseburia relatives appear to be particularly sensitive to the diet composition in human volunteer studies.
Sylvia H Dunca - One of the best experts on this subject based on the ideXlab platform.
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acetate utilization and butyryl coenzyme a coa acetate coa transferase in butyrate Producing Bacteria from the human large intestine
Applied and Environmental Microbiology, 2002Co-Authors: Sylvia H Dunca, C S Stewa, Adela Arcenilla, Susa E Pryde, Harry J FliAbstract:Seven strains of Roseburia sp., Faecalibacterium prausnitzii, and Coprococcus sp. from the human gut that produce high levels of butyric acid in vitro were studied with respect to key butyrate pathway enzymes and fermentation patterns. Strains of Roseburia sp. and F. prausnitzii possessed butyryl coenzyme A (CoA):acetate-CoA transferase and acetate kinase activities, but butyrate kinase activity was not detectable either in growing or in stationary-phase cultures. Although unable to use acetate as a sole source of energy, these strains showed net utilization of acetate during growth on glucose. In contrast, Coprococcus sp. strain L2-50 is a net producer of acetate and possessed detectable butyrate kinase, acetate kinase, and butyryl-CoA:acetate-CoA transferase activities. These results demonstrate that different functionally distinct groups of butyrate-Producing Bacteria are present in the human large intestine.
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phylogenetic relationships of butyrate Producing Bacteria from the human gut
Applied and Environmental Microbiology, 2000Co-Authors: Adela Arcenilla, Sylvia H Dunca, C S Stewa, Susan E Pryde, Jennife C Marti, Coli Henderso, Harry J FliAbstract:Butyrate is a preferred energy source for colonic epithelial cells and is thought to play an important role in maintaining colonic health in humans. In order to investigate the diversity and stability of butyrate-Producing organisms of the colonic flora, anaerobic butyrate-Producing Bacteria were isolated from freshly voided human fecal samples from three healthy individuals: an infant, an adult omnivore, and an adult vegetarian. A second isolation was performed on the same three individuals 1 year later. Of a total of 313 Bacterial isolates, 74 produced more than 2 mM butyrate in vitro. Butyrate-Producing isolates were grouped by 16S ribosomal DNA (rDNA) PCR-restriction fragment length polymorphism analysis. The results indicate very little overlap between the predominant ribotypes of the three subjects; furthermore, the flora of each individual changed significantly between the two isolations. Complete sequences of 16S rDNAs were determined for 24 representative strains and subjected to phylogenetic analysis. Eighty percent of the butyrate-Producing isolates fell within the XIVa cluster of gram-positive Bacteria as defined by M. D. Collins et al. (Int. J. Syst. Bacteriol. 44:812–826, 1994) and A. Willems et al. (Int. J. Syst. Bacteriol. 46:195–199, 1996), with the most abundant group (10 of 24 or 42%) clustering with Eubacterium rectale , Eubacterium ramulus , and Roseburia cecicola . Fifty percent of the butyrate-Producing isolates were net acetate consumers during growth, suggesting that they employ the butyryl coenzyme A-acetyl coenzyme A transferase pathway for butyrate production. In contrast, only 1% of the 239 non-butyrate-Producing isolates consumed acetate.
Thierry Naas - One of the best experts on this subject based on the ideXlab platform.
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the real threat of klebsiella pneumoniae carbapenemase Producing Bacteria
Lancet Infectious Diseases, 2009Co-Authors: Patrice Nordmann, Gaelle Cuzon, Thierry NaasAbstract:Summary From early this decade, EnteroBacteriaceae that produce Klebsiella pneumoniae carbapenemases (KPC) were reported in the USA and subsequently worldwide. These KPC-Producing Bacteria are predominantly involved in nosocomial and systemic infections; although they are mostly EnteroBacteriaceae, they can also be, rarely, Pseudomonas aeruginosa isolates. KPC β lactamases (KPC-1 to KPC-7) confer decreased susceptibility or resistance to virtually all β lactams. Carbapenems (imipenem, meropenem, and ertapenem) may thus become inefficient for treating enteroBacterial infections with KPC-Producing Bacteria, which are, in addition, resistant to many other non-β-lactam molecules, leaving few available therapeutic options. Detection of KPC-Producing Bacteria may be difficult based on routine antibiotic susceptibility testing. It is therefore crucial to implement efficient infection control measures to limit the spread of these pathogens.
Huanming Yang - One of the best experts on this subject based on the ideXlab platform.
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saturated long chain fatty acid Producing Bacteria contribute to enhanced colonic motility in rats
Microbiome, 2018Co-Authors: Ling Zhao, Wei Yang, Tao Huang, Yufe Huang, Hiuyee Kwa, Hoi Leong Xavie Wong, Yang Che, Xuefeng Xie, Xiaodong Fang, Huanming YangAbstract:The gut microbiota is closely associated with gastrointestinal (GI) motility disorder, but the mechanism(s) by which Bacteria interact with and affect host GI motility remains unclear. In this study, through using metabolomic and metagenomic analyses, an animal model of neonatal maternal separation (NMS) characterized by accelerated colonic motility and gut dysbiosis was used to investigate the mechanism underlying microbiota-driven motility dysfunction. An excess of intracolonic saturated long-chain fatty acids (SLCFAs) was associated with enhanced bowel motility in NMS rats. Heptadecanoic acid (C17:0) and stearic acid (C18:0), as the most abundant odd- and even-numbered carbon SLCFAs in the colon lumen, can promote rat colonic muscle contraction and increase stool frequency. Increase of SLCFAs was positively correlated with elevated abundances of Prevotella, Lactobacillus, and Alistipes. Functional annotation found that the level of Bacterial LCFA biosynthesis was highly enriched in NMS group. Essential synthetic genes Fabs were largely identified from the genera Prevotella, Lactobacillus, and Alistipes. Pseudo germ-free (GF) rats receiving fecal microbiota from NMS donors exhibited increased defecation frequency and upregulated Bacterial production of intracolonic SLCFAs. Modulation of gut dysbiosis by neomycin effectively attenuated GI motility and reduced Bacterial SLCFA generation in the colon lumen of NMS rats. These findings reveal a previously unknown relationship between gut Bacteria, intracolonic SLCFAs, and host GI motility, suggesting the importance of SLCFA-Producing Bacteria in GI motility disorders. Further exploration of this relationship could lead to a precise medication targeting the gut microbiota for treating GI motility disorders.
