Abstract
The in vitro activity of grepafloxacin (GPFX), a novel quinolone, was compared with that of lomefloxacin, ciprofloxacin (CPFX), ofloxacin (OFLX) and norfloxacin against 49 reference strains and recent clinical isolates of anaerobic bacteria and Gardnerella vaginalis. The MIC was determined by an agar dilution method. GPFX had broad antibacterial activity against anaerobic gram-positive andnegative cocci and gram-positive and-negative rods. Fifty and ninety percent of Bacteroides fragilis isolates were susceptible to 1.56 and 25μg/ml of GPFX, respectively; the activity of GPFX against the organism was comparable to that of OFLX and CPFX. Against Bacteroides thetaiotaomicron and other members of the B. fragilis group, GPFX was the most potent agent tested (MIC for 50% of the isolates, ≤3.13μg/ml). GPFX demonstrated activity similar to that of OFLX and CPFX against gram-positive cocci: Peptostreptococcus anaerobius, Peptostreptococcus magnus and Peptostreptococcus asaccharolyticus. Although GPFX showed modest activity against Clostridium difficile, the MIC90 was 25μg/ml. The compound was the most active agent tested against Clostridium perfringens, Mobiluncus spp. and G. vaginalis with MIC90 of 0.39, 0.10 and 3.13μg/ml, respectively.
