Effectiveness of cefotaxime alone and in combination with desacetylcefotaxime against Bacteroides fragilis.
The synergistic activity of the combination cefotaxime-desacetylcefotaxime (CTX/dCTX) was compared to the effectiveness of seven other antimicrobial agents: cefoxitin (CFOX), cefotetan (CTAN), ceftizoxime (CTIZ), chloramphenicol (CLOR), clindamycin (CLIND), metronidazole (METR), and ampicillin-sulbactam (A/S) tested against 100 clinical isolates belonging to the Bacteroides fragilis group. All tests were performed using the NCCLS reference agar-dilution method. The overall susceptibility of these organisms to CTX/dCTX was 84% compared to CFOX at 78% or CTAN at 66%. The other antimicrobials inhibited greater than 90% of these isolates. There was no difference between the susceptibility rates of CTX/dCTX and CTX with the B fragilis (85%) or B. distasonis (75%) strains. Bacteroides thetaiotaomicron showed a 11% greater susceptibility to CTX/dCTX than to CTX. Of the 100 isolates tested, 40% showed either synergy or partial synergistic interactions between CTX and dCTX. Most of the isolates showed indifference (52%), while 8% demonstrated antagonism; a relatively unique finding to date.
Wasilauskas
B L
BL
Department of Pathology, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, North Carolina 27103.
D000667:Ampicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001441:Bacteroides fragilis / Q000187:drug effects*; D002439:Cefotaxime / Q000031:analogs & derivatives* / Q000494:pharmacology*; D015313:Cefotetan / Q000494:pharmacology; D002440:Cefoxitin / Q000494:pharmacology; D015296:Ceftizoxime / Q000494:pharmacology; D002701:Chloramphenicol / Q000494:pharmacology; D002981:Clindamycin / Q000494:pharmacology; D004352:Drug Resistance, Microbial; D004357:Drug Synergism; D004359:Drug Therapy, Combination / Q000494:pharmacology; D008795:Metronidazole / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D013407:Sulbactam / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D008795:Metronidazole; D002981:Clindamycin; D015313:Cefotetan; C035444:sultamicillin; D002701:Chloramphenicol; C029281:desacetylcefotaxime; D002440:Cefoxitin; D000667:Ampicillin; D015296:Ceftizoxime; D002439:Cefotaxime; D013407:Sulbactam