Objective(s): Human gastrointestinal tract harbors a variety of bacteria with vital roles in human health. Bacteroides fragilis is considered one of the dominant constituents of gut microflora which can act as an opportunistic pathogen leading to various diseases, including colon cancer, diarrhea, uterine and intrathecal abscesses, septicemia, and pelvic inflammation. ...

The in vitro susceptibility of 155 strains of anaerobic bacteria to five cephalosporin antibiotics was tested. Cefoxitin was the most active against 33 isolates of Bacteroides fragilis; 82% of the strains were sensitive at 16 mug/ml. At 64 mug/ml cefazolin and cephaloridine were also generally effective. Cephalothin and cephalexin were relatively inactive versus B. fragilis. Cefoxitin, cephalor...

We studied the effect of pH (7.1, 6.3, and 5.8) on the in vitro susceptibilities of 59 isolates of Bacteroides fragilis and 60 isolates of other B. fragilis group species to trovafloxacin, ciprofloxacin, clindamycin, ampicillin-sulbactam, piperacillin-tazobactam, imipenem, and meropenem. For each agent tested the geometric mean MIC was highest at pH 5.8, intermediate at pH 6.3, and lowest at pH...

In order to determine the therapeutic value of penicillins in the management of anaerobic infections caused by Bacteroides fragilis, the antibacterial activity of penicillin G, ampicillin, and carbenicillin against 10 strains of B. fragilis subsp. fragilis, isolated from clinical material, was studied. This was undertaken by using a triple-layer technique, enzymatic inactivation of the antibiot...

A total of 94 clinical isolates of the Bacteroides fragilis group was tested for susceptibility to metronidazole, chloramphenicol, clindamycin, cefoxitin, cefotetan, cefmetazole, moxalactam, mezlocillin, amoxicillin-clavulanic acid, and imipenem. All the strains tested were susceptible to imipenem, metronidazole, amoxicillin-clavulanic acid, and chloramphenicol. The rate of resistance to clinda...

The in vitro activities of ofloxacin alone and in combination with metronidazole against 177 anaerobic bacteria isolated from intra-abdominal infections, as determined by broth microdilution, showed that some Bacteroides fragilis strains were susceptible and that most other B. fragilis group species strains were resistant to ofloxacin. Isolates of other anaerobic species and genera, including t...

The extracellular production of hyaluronidase and chondroitin sulfatase was demonstrated in all of the subspecies of Bacteroides fragilis tested with the exception of B. fragilis subsp. vulgatus. Elastase was found only in one strain of B. coagulans tested. This appears to be the first report of these enzyme activities in this genus. Additional enzymes found to be produced by certain members ot...

Twenty-one patients with serious infections involving anaerobic bacteria were treated with carbenicillin. Multiple anaerobes were involved in 8 cases, and in 10 cases, facultative anaerobes were also isolated. Bacteroides fragilis was isolated in 10 cases. Results were judged excellent in 7 cases, good in 8 cases, and fair in 5 cases. These data suggest that carbenicillin may be an effective an...

Enterotoxigenic Bacteroides fragilis (ETBF) is a human gut commensal bacteria that causes inflammatory diarrhea and colitis. ETBF also promotes colorectal tumorigenesis in the Min mouse model. The key virulence factor is a secreted metalloprotease called B. fragilis toxin (BFT). BFT induces E-cadherin cleavage, cell rounding, activation of the β-catenin pathway and secretion of IL-8 in colonic ...

This study developed a new statistical strategy for analyzing clone library data to observe whether there is a defined pattern in structural responses of gut microbiota to environmental perturbations. A large clone library of genus Bacteroides was constructed with fecal samples for each subject in rotavirus-infected (Group R) and healthy children (Group H). In all, 665 clones of the 12 Group H ...