The Experts below are selected from a list of 1068 Experts worldwide ranked by ideXlab platform
Mark Morrison - One of the best experts on this subject based on the ideXlab platform.
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the gut bacterium and pathobiont Bacteroides vulgatus activates nf κb in a human gut epithelial cell line in a strain and growth phase dependent manner
Anaerobe, 2017Co-Authors: Paraic O Cuiv, Tomas De Wouters, Rabina Giri, Stanislas Mondot, Wendy J Smith, Herve M Blottiere, Jakob Begun, Mark MorrisonAbstract:The gut microbiota is increasingly implicated in the pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC) although the identity of the bacteria that underpin these diseases has remained elusive. The pathobiont Bacteroides vulgatus has been associated with both diseases although relatively little is known about how its growth and functional activity might drive the host inflammatory response. We identified an ATP Binding Cassette (ABC) export system and lipoprotein in B. vulgatus ATCC 8482 and B. vulgatus PC510 that displayed significant sequence similarity to an NF-κB immunomodulatory regulon previously identified on a CD-derived metagenomic fosmid clone. Interestingly, the ABC export system was specifically enriched in CD subjects suggesting that it may be important for colonization and persistence in the CD gut environment. Both B. vulgatus ATCC 8482 and PC510 activated NF-κB in a strain and growth phase specific manner in a HT-29/kb-seap-25 enterocyte like cell line. B. vulgatus ATCC 8482 also activated NF-κB in a Caco-2-NF-κBluc enterocyte like and an LS174T-NF-κBluc goblet cell like cell lines, and induced NF-κB-p65 subunit nuclear translocation and IL-6, IL-8, CXCL-10 and MCP-1 gene expression. Despite this, NF-κB activation was not coincident with maximal expression of the ABC exporter or lipoprotein in B. vulgatus PC510 suggesting that the regulon may be necessary but not sufficient for the immunomodulatory effects.
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draft genome sequence of Bacteroides vulgatus pc510 a strain isolated from human feces
Journal of Bacteriology, 2011Co-Authors: Paraic O Cuiv, Eline S Klaassens, Scott A Durkin, Derek M Harkins, Les Foster, Jamison Mccorrison, Manolito Torralba, Karen E Nelson, Mark MorrisonAbstract:Although Bacteroides vulgatus is one of the most prevalent microorganisms in the human gastrointestinal tract, little is known about the genetic potential of this species. Here, we describe the annotated draft genome sequence of B. vulgatus PC510 isolated from human feces.
Teruo Kirikae - One of the best experts on this subject based on the ideXlab platform.
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structural study on lipid a and the o specific polysaccharide of the lipopolysaccharide from a clinical isolate of Bacteroides vulgatus from a patient with crohn s disease
FEBS Journal, 2002Co-Authors: Masahito Hashimoto, Yasuo Suda, Fumiko Kirikae, Taeko Dohi, Shoichi Kusumoto, Seizi Adachi, Tsuyoshi Fujita, Hideo Naoki, Teruo KirikaeAbstract:Bacteroides vulgatus has been shown to be involved in the aggravation of colitis. Previously, we separated two potent virulence factors, capsular polysaccharide (CPS) and lipopolysaccharide (LPS), from a clinical isolate of B. vulgatus and characterized the structure of CPS. In this study, we elucidated the structures of O-antigen polysaccharide (OPS) and lipid A in the LPS. LPS was subjected to weak acid hydrolysis to produce the lipid A fraction and polysaccharide fraction. Lipid A was isolated by preparative TLC, and its structure determined by MS and NMR to be similar to that of Bacteroides fragilis except for the number of fatty acids. The polysaccharide fraction was subjected to gel-filtration chromatography to give an OPS-rich fraction. The structure of OPS was determined by chemical analysis and NMR spectroscopy to be a polysaccharide composed of the following repeating unit: [-->4)alpha-L-Rhap(1-->3)beta-D-Manp(1-->].
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structural study on lipid a and the o specific polysaccharide of the lipopolysaccharide from a clinical isolate of Bacteroides vulgatus from a patient with crohn s disease
FEBS Journal, 2002Co-Authors: Masahito Hashimoto, Yasuo Suda, Fumiko Kirikae, Taeko Dohi, Shoichi Kusumoto, Seizi Adachi, Tsuyoshi Fujita, Hideo Naoki, Teruo KirikaeAbstract:Bacteroides vulgatus has been shown to be involved in the aggravation of colitis. Previously, we separated two potent virulence factors, capsular polysaccharide (CPS) and lipopolysaccharide (LPS), from a clinical isolate of B. vulgatus and characterized the structure of CPS. In this study, we elucidated the structures of O-antigen polysaccharide (OPS) and lipid A in the LPS. LPS was subjected to weak acid hydrolysis to produce the lipid A fraction and polysaccharide fraction. Lipid A was isolated by preparative TLC, and its structure determined by MS and NMR to be similar to that of Bacteroides fragilis except for the number of fatty acids. The polysaccharide fraction was subjected to gel-filtration chromatography to give an OPS-rich fraction. The structure of OPS was determined by chemical analysis and NMR spectroscopy to be a polysaccharide composed of the following repeating unit: [4)α-l-Rhap(13)β-d-Manp(1].
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structural elucidation of a capsular polysaccharide from a clinical isolate of Bacteroides vulgatus from a patient with crohn s disease
FEBS Journal, 2001Co-Authors: Fumiko Kirikae, Taeko Dohi, Shoichi Kusumoto, Teruo KirikaeAbstract:The structure of a capsular polysaccharide (CPS) from a clinical isolate of Bacteroides vulgatus was elucidated. B. vulgatus IMCJ 1204 was isolated from feces of a patient with Crohn's disease. CPS was prepared by phenol/water extraction of the bacterial cells followed by hydrophobic interaction chromatography and then gel filtration chromatography of the extract. The structure of CPS was determined by chemical analysis and NMR spectroscopy including DQF-COSY, TOCSY, ROESY, HSQC-TOCSY, HMQC and HMBC to be a polysaccharide composed of the following repeating unit: -->3)beta-D-Glcp(1-->6)[alpha-D-GalpNAc(1-->2)beta-D-Galp(1-->4)]beta-D-GlcpNAc(1-->3)alpha-D-Galp(1-->4)beta-D-Manp(1-->.
Euclides Matheucci - One of the best experts on this subject based on the ideXlab platform.
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detection of increased plasma interleukin 6 levels and prevalence of prevotella copri and Bacteroides vulgatus in the feces of type 2 diabetes patients
Frontiers in Immunology, 2017Co-Authors: Aline Zazeri Leite, Nathalia De Campos Rodrigues, Marina Ignacio Gonzaga, Joao Carlos Cicogna Paiolo, Carolina Arantes De Souza, Nadine Stefanutto, Wellington Pine Omori, Daniel Guariz Pinheiro, Joao Luiz Brisotti, Euclides MatheucciAbstract:Intestinal dysbiosis and metabolic endotoxemia has been associated with metabolic disorders, such as obesity, insulin resistance and type 2 diabetes (T2D). The main goal of the present study was to evaluate the intestinal dysbiosis in Brazilian T2D patients and correlate these data with inflammatory cytokines and lipopolysaccharides (LPS) plasma concentrations. This study was approved by the Ethics Committees from Barretos Cancer Hospital and all individuals signed the informed consent form. Stool samples were required for DNA extraction, and the V3/V4 regions of bacterial 16S were sequenced using an Illumina platform. Peripheral blood were used to quantify inflammatory cytokines and plasma LPS concentrations, by CBA flex and ELISA, respectively. Statistical analyses were performed using Mann-Whitney and Spearman’s tests. Analysis of variance, diversity indexes and analysis of alpha and beta-diversity were conducted using an annotated OTU table. This study included 20 patients and 22 controls. We observed significant differences (P<0.01) in the microbiota composition (beta-diversity) between patients and controls, suggesting intestinal dysbiosis in Brazilian T2D patients. The prevalent species found in patients’ feces were the gram-negatives Prevotella copri, Bacteroides vulgatus, Bacteroides rodentium, and Bacteroides xylanisolvens. The proinflammatory interleukin-6 (IL-6) was significantly increased (P<0.05) in patients’ plasma and LPS levels were decreased. We find correlations between the proinflammatory interferon-gamma (IFN-γ) with gram-negatives Bacteroides and Prevotella species, and a positive correlation between the LPS levels and Prevotella copri reads. The Prevotella copri and Bacteroides vulgatus species were associated with insulin resistance in previous studies. In this study, we suggested that the prevalence of gram-negative species in the gut and the increased plasma IL-6 in patients could be linked to low-grade inflammation and insulin resistance. In conclusion, the Prevotella copri and Bacteroides vulgatus species could represent an intestinal microbiota signature, associated with T2D development. Furthermore, the identification of these gram-negative bacteria, and the detection of inflammatory markers, such as increased IL-6, could be used as diabetes predictive markers in overweight, obese and in genetically predisposed individuals to develop T2D.
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Detection of Increased Plasma Interleukin-6 Levels and Prevalence of Prevotella copri and Bacteroides vulgatus in the Feces of Type 2 Diabetes Patients
Frontiers Media S.A., 2017Co-Authors: Aline Zazeri Leite, Nathalia De Campos Rodrigues, Marina Ignacio Gonzaga, Joao Carlos Cicogna Paiolo, Carolina Arantes De Souza, Nadine Stefanutto, Wellington Pine Omori, Daniel Guariz Pinheiro, Joao Luiz Brisotti, Euclides MatheucciAbstract:Intestinal dysbiosis and metabolic endotoxemia have been associated with metabolic disorders, such as obesity, insulin resistance, and type 2 diabetes (T2D). The main goal of the present study was to evaluate the intestinal dysbiosis in Brazilian T2D patients and correlate these data with inflammatory cytokines and lipopolysaccharides (LPS) plasma concentrations. This study was approved by the Ethics Committees from Barretos Cancer Hospital and all individuals signed the informed consent form. Stool samples were required for DNA extraction, and the V3/V4 regions of bacterial 16S were sequenced using an Illumina platform. Peripheral blood was used to quantify inflammatory cytokines and plasma LPS concentrations, by CBA flex and ELISA, respectively. Statistical analyses were performed using Mann–Whitney and Spearman’s tests. Analysis of variance, diversity indexes, and analysis of alpha- and beta-diversity were conducted using an annotated Operational Taxonomic Unit table. This study included 20 patients and 22 controls. We observed significant differences (P < 0.01) in the microbiota composition (beta-diversity) between patients and controls, suggesting intestinal dysbiosis in Brazilian T2D patients. The prevalent species found in patients’ feces were the Gram-negatives Prevotella copri, Bacteroides vulgatus, Bacteroides rodentium, and Bacteroides xylanisolvens. The proinflammatory interleukin-6 (IL-6) was significantly increased (P < 0.05) in patients’ plasma and LPS levels were decreased. We find correlations between the proinflammatory interferon-gamma with Gram-negatives Bacteroides and Prevotella species, and a positive correlation between the LPS levels and P. copri reads. The P. copri and B. vulgatus species were associated with insulin resistance in previous studies. In this study, we suggested that the prevalence of Gram-negative species in the gut and the increased plasma IL-6 in patients could be linked to low-grade inflammation and insulin resistance. In conclusion, the P. copri and B. vulgatus species could represent an intestinal microbiota signature, associated with T2D development. Furthermore, the identification of these Gram-negative bacteria, and the detection of inflammatory markers, such as increased IL-6, could be used as diabetes predictive markers in overweight, obese and in genetically predisposed individuals to develop T2D
J P G Ballesta - One of the best experts on this subject based on the ideXlab platform.
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antibiotic sensitivity of ribosomes from wild type and clindamycin resistant Bacteroides vulgatus strains
Journal of Antimicrobial Chemotherapy, 1992Co-Authors: Antonio Jimenezdiaz, M Reig, Fernando Baquero, J P G BallestaAbstract:The sensitivity to different antibiotics of in-vitro polyuridylic acid-dependent polypeptide synthesizing system from Bacteroides vulgatus RYC18F6 and two clindamycin-resistant derivatives was studied. The ribosomes from the resistant strains were not affected by concentrations of up to 0.1 mM clindamycin and lincomycin. In contrast, streptogramin B was found to cause strong stimulation of the clindamycin-resistant polymerizing systems. The modified ribosomes from the resistant strains were more sensitive to other antibiotics like sparsomycin and chloramphenicol. The data indicate that resistance in these B. vulgatus mutant strains is due to alteration of the ribosome structure.
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inducible expression of ribosomal clindamycin resistance in Bacteroides vulgatus
Antimicrobial Agents and Chemotherapy, 1992Co-Authors: M Reig, M C Fernandez, J P G Ballesta, Fernando BaqueroAbstract:The abilities of erythromycin and clindamycin to act as inducers of clindamycin resistance in the strain Bacteroides vulgatus RYC18F6 is evaluated in vivo (efficiency of plating of inhibitory clindamycin concentrations) and in vitro [efficiency of poly(U)-directed polypeptide synthesis by ribosomes]. Uninduced cells failed to grow during the first 72 h, even at a very low clindamycin concentration (0.1 microgram/ml); after induction with erythromycin or clindamycin, cells were able to form colonies at 32 micrograms/ml after 48 h. The in vitro polymerization test with B. vulgatus RYC18F6 ribosomes (S-30 extract) showed that ribosomes from uninduced cells were fully sensitive to the inhibitory effect of clindamycin. Ribosomes obtained from erythromycin- or clindamycin-induced cells presented a reduced sensitivity to clindamycin inhibition. These results show that resistance to clindamycin in B. vulgatus RYC18F6 is an inducible phenomenon involving a ribosomal modification, probably similar to that previously described for gram-positive bacteria.
Fernando Baquero - One of the best experts on this subject based on the ideXlab platform.
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antibiotic sensitivity of ribosomes from wild type and clindamycin resistant Bacteroides vulgatus strains
Journal of Antimicrobial Chemotherapy, 1992Co-Authors: Antonio Jimenezdiaz, M Reig, Fernando Baquero, J P G BallestaAbstract:The sensitivity to different antibiotics of in-vitro polyuridylic acid-dependent polypeptide synthesizing system from Bacteroides vulgatus RYC18F6 and two clindamycin-resistant derivatives was studied. The ribosomes from the resistant strains were not affected by concentrations of up to 0.1 mM clindamycin and lincomycin. In contrast, streptogramin B was found to cause strong stimulation of the clindamycin-resistant polymerizing systems. The modified ribosomes from the resistant strains were more sensitive to other antibiotics like sparsomycin and chloramphenicol. The data indicate that resistance in these B. vulgatus mutant strains is due to alteration of the ribosome structure.
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inducible expression of ribosomal clindamycin resistance in Bacteroides vulgatus
Antimicrobial Agents and Chemotherapy, 1992Co-Authors: M Reig, M C Fernandez, J P G Ballesta, Fernando BaqueroAbstract:The abilities of erythromycin and clindamycin to act as inducers of clindamycin resistance in the strain Bacteroides vulgatus RYC18F6 is evaluated in vivo (efficiency of plating of inhibitory clindamycin concentrations) and in vitro [efficiency of poly(U)-directed polypeptide synthesis by ribosomes]. Uninduced cells failed to grow during the first 72 h, even at a very low clindamycin concentration (0.1 microgram/ml); after induction with erythromycin or clindamycin, cells were able to form colonies at 32 micrograms/ml after 48 h. The in vitro polymerization test with B. vulgatus RYC18F6 ribosomes (S-30 extract) showed that ribosomes from uninduced cells were fully sensitive to the inhibitory effect of clindamycin. Ribosomes obtained from erythromycin- or clindamycin-induced cells presented a reduced sensitivity to clindamycin inhibition. These results show that resistance to clindamycin in B. vulgatus RYC18F6 is an inducible phenomenon involving a ribosomal modification, probably similar to that previously described for gram-positive bacteria.
