In-vitro activity of fleroxacin compared with three other quinolones.

The in-vitro activity of fleroxacin (Ro23-6240), a new synthetic quinolone, was compared with that of three other quinolones against 665 clinical isolates of aerobic bacteria by the agar dilution technique. Fleroxacin showed similar activity to norfloxacin, enoxacin and pefloxacin against most isolates of Enterobacteriaceae, Neisseria meningitidis, N. gonorrhoeae, Haemophilis influenzae, Staphylococcus spp. and streptococcus faecalis. Fleroxacin was the most active quinolone against Enterobacter spp. Fleroxacin was not as active against Pseudomonas aeruginosa, but the MIC90 (4 mg/l) is still below the reported peak serum level after a standard oral dose of 400 mg.