A five-year multicenter study of the susceptibility of the Bacteroides fragilis group isolates to cephalosporins, cephamins, penicillins, clindamycin, and metronidazole in the United States.

Journal Article (Journal Article;Multicenter Study)

Over 2800 clinical strains of the Bacteroides fragilis group were collected during a 5-year period from ten geographically separate sites and tested for their susceptibility to various antimicrobial agents using a broth microdilution method. Among the cephalosporins, ceftizoxime was the most active (13% resistance) and importantly exhibited relatively equal activity against both B. fragilis species and non-B. fragilis species. Cefotaxime exhibited similar activity with an overall resistance rate of 18%. Both ceftriaxone and cefoperazone were appreciably less active cephalosporins especially against non-B. fragilis species. With regard to cephamycins, cefoxitin (MIC90, 32 micrograms/ml) was more active than cefotetan (MIC90, > or = 256 micrograms/ml) and cefmetazole (MIC90, 64 micrograms/ml). Non-B. fragilis species were highly resistant to cefotetan and cefmetazole. Imipenem was highly active against all strains with the exception of four strains of B. fragilis. Ampicillin-sulbactam, amoxicillin-clavulanate, piperacillin-tazobactam, and cefoperazone-sulbactam were all highly active with resistance rates < 2%. No resistance was detected to metronidazole, whereas 14% of isolates were resistant to clindamycin. When compared with other studies, these findings underscore the wide variability in susceptibility patterns reported nationwide and the need to continue monitoring these patterns to aid in choosing the most active compounds for therapy.

Full Text

Duke Authors

Cited Authors

  • Aldridge, KE; Gelfand, M; Reller, LB; Ayers, LW; Pierson, CL; Schoenknecht, F; Tilton, RC; Wilkins, J; Henderberg, A; Schiro, DD

Published Date

  • April 1, 1994

Published In

Volume / Issue

  • 18 / 4

Start / End Page

  • 235 - 241

PubMed ID

  • 7924220

International Standard Serial Number (ISSN)

  • 0732-8893

Digital Object Identifier (DOI)

  • 10.1016/0732-8893(94)90026-4


  • eng

Conference Location

  • United States