In vitro activity of quinolones and other antimicrobial agents against anaerobic bacteria.

The in vitro activities of ciprofloxacin, ofloxacin, sparfloxacin, and DU-6859a against peptostreptococci, Clostridium perfringens, Clostridium difficile, Bacteroides fragilis, Porphyromonas, Prevotella, and Fusobacterium were determined by an agar dilution method. These activities were compared with those of piperacillin/tazobactam, cefoxitin, imipenem, clindamycin, and metronidazole. Imipenem, metronidazole, and DU-6859a were the most active antimicrobial agents that were tested. The in vitro activity of DU-6859a was superior to those of ciprofloxacin, lomefloxacin, ofloxacin, and sparfloxacin.