Antibiotic sensitivity of the Bacteroides fragilis group in Denmark. Danish Study Group

Resistance rates to 9 antibiotics were determined for 370 isolates of the Bacteroides fragilis group submitted during a 5-month period in 1990-91 from 6 laboratories in Denmark. There was no resistance to imipenem (MIC > 8 mg/l) or metronidazole (MIC > 16 mg/l), while resistance to ampicillin was the rule (97% at > 4 mg/l) and to ceftriaxone rather common (19% at > 32 mg/l). Resistance was uncommon to cefoxitin (0.5% at > 32 mg/l), cefotaxime (6% at > 32 mg/l), piperacillin (7% at > 64 mg/l), ampicillin/sulbactam (1% at > 16 mg/l), and clindamycin (3% at > 4 mg/l). Two hundred and thirty-nine strains were Bacteroides fragilis. The 131 other strains were generally more resistant than the Bacteroides fragilis strains. For 5 antibiotics the Bacteroides fragilis had a significantly lower MIC in western than in eastern laboratories. For the group with other strains there was no significant difference.