Activity of ampicillin/sulbactam, ticarcillin/clavulanate, clarithromycin, and eleven other antimicrobial agents against anaerobic bacteria isolated from infections in children.

The activity of 14 antimicrobial agents against 253 clinical isolates of anaerobic bacteria from pediatric infections was assessed by the agar dilution method. Fifty-eight percent of the isolates were from intraabdominal sites. The drugs tested were ampicillin/sulbactam, ticarcillin/clavulanate, ampicillin, sulbactam, piperacillin, cefoxitin, cefotaxime, cefoperazone/sulbactam, clarithromycin, azithromycin, erythromycin, clindamycin, metronidazole, and chloramphenicol. Ticarcillin/clavulanate was active against all isolates. Clarithromycin was the most active macrolide; combination of this agent with its 14-hydroxy metabolite did not result in synergy. Sixty-two percent of Bacteroides fragilis group isolates, 13% of B. fragilis isolates, and 22% of peptostreptococcal isolates were resistant to clindamycin at a concentration of 4 micrograms/mL. The distribution of these strains in clinical specimens and the patterns of antimicrobial susceptibility documented were different from the findings for isolates from adults in the Los Angeles area.