In vitro activities of pazufloxacin, a novel injectable quinolone, against bacteria causing infections in obstetric and gynecological patients

T-3762 is an injectable new quinolone with a broad spectrum of antibacterial activity. Pazufloxacin (T-3761) is an active form of T-3762. The minimal inhibitory concentrations (MICs) of pazufloxacin for 50% of the clinical isolates tested were 3.13 µg/ml for Streptococcus agalactiae, 6.25 µg/ml for Gardnerella vaginalis, 0.025 µg/ml for Escherichia coli, 0.78 µg/ml for Pseudomonas aeruginosa, 6.25 µg/ml for Peptostreptococcus magnus, 6.25 µg/ml for Bacteroides fragilis and 12.5 µg/ml for Prevotella bivia. The MICs of T-3762 for 90% of the clinical isolates tested were 3.13 µg/ml for S. agalactiae, 6.25 µg/ml for G. vaginalis, 0.10 µg/ml for E. coli, 12.5 µg/ml for P. aeruginosa, 25 µg/ml for P. magnus, 12.5 µg/ml for B. fragilis and 25 µg/ml for P. bivia. The results of this study suggest that, subject to confirmation by clinical trials, T-3762, in combination with an agent with reliable activity against anaerobic bacteria, is suitable as an empirical therapy of patients with obstetric and gynecological infections.