Evaluation of in vitro activity of a new fluoroquinolone trovafloxacin (cp-99,219) compared with other anti-anaerobic antimicrobials against members of the Bacteroides fragilis group

The in vitro activity of a new fluoroquinolone, trovafloxacin (CP-99,219) was compared with that of ten other agents against 100 clinical isolates in the Bacteroides fragilis group. Trovafloxacin was the most active quinolone (MIC90, 1 mu g/ml) followed by sparfloxacin (MIC90, 8 mu g/ml), levofloxacin (MIC90, 16 mu g/ml) and ofloxacin (MIC90, 32 mu g/ml). Ciprofloxacin was the least active quinolone (MIC90, 64 mu g/ml). Metronidazole, chloramphenicol, imipenem and piperacillin/tazobactam, showed excellent activity with an MIC90 of 1, 8, 0.25 and 16 mu g/ml, respectively. Cefoxitin showed good activity and piperacillin was the least active compound. B. vulgatus and B. ovatus were the most resistant species to trovafloxacin among those of the B.fragilis group with an MIC90 of 4 mu g/ml while B. fragilis and B. thetaiotaomicron were the most susceptible (MIC90, 1 mu g/ml). (C) 1997 Elsevier Science B.V.