title: Bacteremia due to Bacteroides fragilis group: distribution of species, beta-lactamase production, and antimicrobial susceptibility patterns.
abstract: A retrospective analysis of susceptibility data on 542 blood isolates of the Bacteroides fragilis group tested from 1987 to 1999 by the same NCCLS-recommended broth microdilution method throughout is presented. Metronidazole, beta-lactam-beta-lactamase inhibitor combinations, carbapenems, and trovafloxacin were the most active agents (susceptibility of >or=93%). Among the cephalosporin-cephamycins, the order of activity was cefoxitin > ceftizoxime > cefotetan = cefotaxime = cefmetazole > ceftriaxone. All isolates were resistant to penicillin G, and 22% were resistant to clindamycin. The susceptibility rates to piperacillin-tazobactam, imipenem, and meropenem were affected least among isolates resistant to cefoxitin or clindamycin. Except for piperacillin-tazobactam, imipenem, and meropenem, the B. fragilis species was more susceptible than were the non-B. fragilis species. These data underscore the importance of susceptibility testing of the B. fragilis group and can serve as a guide in the choice of empirical antimicrobial therapy.
authors.affiliation: Department of Medicine (Infectious Diseases), Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, USA.
authors.forename: Kenneth E
authors.initials: KE
authors.lastname: Aldridge
authors.forename: Deborah
authors.initials: D
authors.lastname: Ashcraft
authors.forename: Megan
authors.initials: M
authors.lastname: O'Brien
authors.forename: Charles V
authors.initials: CV
authors.lastname: Sanders
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001442:Bacteroides Infections / Q000097:blood / Q000201:enzymology*; D001441:Bacteroides fragilis / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D008826:Microbial Sensitivity Tests; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases