Multicenter evaluation of the in vitro activities of three new quinolones, sparfloxacin, CI-960, and PD 131,628, compared with the activity of ciprofloxacin against 5,252 clinical bacterial isolates.

The in vitro activities of three new quinolones (sparfloxacin, CI-960, and PD 131,628) were compared with that of ciprofloxacin against 5,252 routine clinical aerobic and facultatively anaerobic bacterial isolates. Overall, CI-960 was the most active drug in vitro (MIC for 90% of the strains tested, 0.13 micrograms/ml); ciprofloxacin and sparfloxacin were the least active (MIC for 90% of the strains tested, 1.0 micrograms/ml). All three new quinolones, but particularly CI-960 and PD 131,628, exhibited significantly greater activity than ciprofloxacin against enterococci and staphylococci.