In vitro activity of CI-934 compared with ciprofloxacin, enoxacin, norfloxacin, and vancomycin.

The in vitro activity of the quinolone CI-934 was compared with ciprofloxacin, norfloxacin, enoxacin, and vancomycin against 607 Gram-positive and -negative isolates. CI-934 inhibited 90% of the Enterobacteriaceae, Aeromonas hydrophila, and Acinetobacter spp. at 1 microgram/ml. Decreased activity was observed against Pseudomonas aeruginosa. Pseudomonas maltophilia, and other Pseudomonas spp. with CI-934 MIC90 greater than or equal to 8 micrograms/ml. CI-934 activity against Gram-positive organisms exceeded vancomycin and the other quinolones. MIC90 for Streptococcus faecalis, Listeria monocytogenes, and Corynebacterium spp. were less than or equal to 2 micrograms/ml. CI-934 was equally effective against oxacillin-susceptible and -resistant staphylococci with MIC90 of 0.5 micrograms/ml.