Disease relevance of Bacteroides

• Bacteremia with a doxycycline-resistant Bacteroides fragilis developed in one patient during therapy [1].
• Here we show that monocytes from individuals heterozygous for both mutations in the TLR4 gene exhibit no deficit in recognition of LPS of Escherichia coli, Neisseria meningitidis, Bacteroides fragilis, Yersinia pestis, Chlamydia trachomatis, Porphyromonas gingivalis, or Pseudomonas aeruginosa [2].
• In contrast, none of 16 other fecal Bacteroides, Escherichia coli, Streptococcus faecalis, and Bifidobacterium strains produced ABH blood group-degrading enzymes; other glycosidases produced by these strains were predominantly cell bound except for extracellular beta-N-acetylhexosaminidases produced by the five S. faecalis strains [3].
• A luminal PO2 of approximately 700 mm Hg did not significantly influence the fecal concentration of total anaerobes recovered on rabbit blood agar or of Bifidobacterium sp. and Bacteroides sp. recovered on selective media [4].
• Phylogenetic comparative analyses of RNase P RNA-encoding gene sequences from Chlorobium limicola, Chlorobium tepidum, Bacteroides thetaiotaomicron, and Flavobacterium yabuuchiae refine the secondary structure model of the general (eu)bacterial RNase P RNA and show that a highly conserved feature of that RNA is not essential [5].

High impact information on Bacteroides

• This means of generating surface diversity allows the organism to exhibit a wide array of distinct surface polysaccharide combinations, and may have broad implications for how the predominant human colonic microorganisms, the Bacteroides species, maintain an ecological niche in the intestinal tract [6].
• Colonization of germ-free mice with Bacteroides thetaiotaomicron, a component of this flora, restored the fucosylation program, whereas an isogenic strain carrying a transposon insertion that disrupts its ability to use L-fucose as a carbon source did not [7].
• Ang4 expression is induced by Bacteroides thetaiotaomicron, a predominant member of the gut microflora, revealing a mechanism whereby intestinal commensal bacteria influence gut microbial ecology and shape innate immunity [8].
• The clinical significance of clindamycin-resistant Bacteroides fragilis [9].
• Seven patients with infections including Bacteroides fragilis were treated with penicillin G, and all responded well [10].

Chemical compound and disease context of Bacteroides

• Metronidazole-resistant Bacteroides from untreated patient [11].
• Simultaneous resistance to metronidazole, co-amoxiclav, and imipenem in clinical isolate of Bacteroides fragilis [12].
• Clavulanic acid and susceptibility of Bacteroides fragilis to penicillin [13].
• Enzyme-mediated resistance of Bacteroides fragilis to moxalactam [14].
• Metronidazole and tetracycline eliminated Bacteroides sp. from blind loops, but polymyxin B and gentamicin did not.(ABSTRACT TRUNCATED AT 400 WORDS)[15]

Biological context of Bacteroides

• The polysaccharide capsule of Bacteroides fragilis has been shown to be important in the virulence of the organism [16].
• Cellular immunity to Bacteroides fragilis capsular polysaccharide [16].
• The genomes of P. putida, P. aeruginosa, Nitrosomonas europaea, Bacteroides thetaiotaomicron and Caulobacter crescentus predict the existence of many more such transcriptional regulatory devices [17].
• Isoforms IA and III-PII had an identical N-terminal amino acid sequence which showed homologies to the N-terminal sequence of sialidases produced by Bacteroides fragilis SBT3182, another commensal enteric bacterium [18].
• A DNA fragment was cloned from Bacteroides fragilis that bestowed low-level tetracycline resistance to Escherichia coli strains harbouring the cloned fragment on a multicopy plasmid [19].

Anatomical context of Bacteroides

• Effect of human colonic microsomes and cell-free extracts of Bacteroides fragilis on the mutagenicity of 2-aminoanthracene [20].
• Strains of Bacteroides fragilis associated with diarrheal disease (enterotoxigenic B. fragilis) produce a 20-kDa zinc-dependent metalloprotease toxin (B. fragilis enterotoxin; BFT) that reversibly stimulates chloride secretion and alters tight junctional function in polarized intestinal epithelial cells [21].
• A histidine auxotroph of Salmonella typhimurium, strain TA1538, will lodge for several months in the gastrointestinal tract of otherwise germ-free rats and of rats additionally associated with bacteria characteristic of the normal flora such as Lactobacillus plantarum and Bacteroides vulgatus [22].
• The large-molecular-sized zwitterionic capsular polysaccharide of the anaerobe Bacteroides fragilis NCTC 9343, designated polysaccharide (PS) A, stimulates T cell proliferation in vitro and induces T cell-dependent protection against abscess formation in vivo [23].
• LPS regulation of the immune response: separate mechanisms for murine B cell activation by lipid A (direct) and polysaccharide (macrophage-dependent) derived from Bacteroides LPS [24].

Gene context of Bacteroides

• VSL3 DNA inhibited colonic interferon (IFN)-gamma secretion in mouse colons and also attenuated a Bacteroides vulgatus-induced IFN-gamma release from murine splenocytes [25].
• Furthermore, IL-6 was detected mainly in the supernatant of fibroblast cultures stimulated with Bacteroides LPS [26].
• Endogenously induced beta interferon was suggested to be necessary for fibroblasts to produce cell-associated IL-1 alpha in response to Bacteroides LPS [26].
• The stimulation of TNF production by E. coli LPS was between two- and fourfold more than that by Bacteroides LPS in MNL, in THP-1 cells (with enhancement for CD14), and in peritoneal macrophages from C3H/HeN mice [27].
• Bacteroides fragilis-derived LPS, however, can effectively stimulate MIP-2 expression in the absence of functional TLR4 in the 10ScNCr/23 cell line [28].

Analytical, diagnostic and therapeutic context of Bacteroides

• 43 specimens from a variety of sites were directly examined by indirect immunofluorescence assay (I.F.A.) with specific antisera against the capsular polysaccharide of Bacteroides fragilis and pooled antisera against a number of serotypes of Bacteroides sp. (all of the former B. fragilis subspecies) [29].
• In four patients with continent ileostomy and malabsorption of B12, there was evidence of a stagnant loopsyndrome as oral lincomycin treatment resulted in increased absorption of B12 decreased excretion of faecal fat, and decreased concentrations of Bacteroides in the ileum [30].
• The hemagglutinating factor (hemagglutinin) of Bacteroides gingivalis was prepared from the supernatant of a 5-day diffusate broth culture by ammonium sulfate precipitation and column chromatography with a hydrophobic column of Phenyl-Sepharose CL-4B, DEAE-Sephadex A-50, and Sephadex G-100 gel filtration [31].
• The 747-bp cfiA gene, which encodes a metallo-beta-lactamase, and the regions flanking cfiA in six imipenem-resistant and four imipenem-susceptible Bacteroides fragilis strains isolated in Japan were analyzed by PCR and DNA sequencing [32].
• However, cefoxitin provided serum and uterine concentrations above the minimum inhibitory concentration of Bacteroides fragilis for a longer period than did cefotaxime [33].

References