title: In vitro activity of the new 4-quinolone compound Ro 23-6240.
abstract: The in vitro activity of the new 4-quinolone Ro 23-6240 was compared with that of pefloxacin, ciprofloxacin, norfloxacin, nalidixic acid and gentamicin against a total of 397 recent clinical isolates. An agar dilution procedure was used to determine MICs and two inocula (10(4) and 10(6) CFU) were used throughout. Ro 23-6240 inhibited most species of the Enterobacteriaceae, Haemophilus influenzae and Staphylococcus aureus (including methicillin-resistant strains) at less than or equal to 1 mg/l. Pseudomonas aeruginosa was somewhat more resistant (MIC 90 4 mg/l) and the Bacteroides fragilis group were considerably more resistant (MIC 90 32 mg/l). Overall Ro 23-6240 was as active as pefloxacin but was two- to eight-fold less active than ciprofloxacin against most species tested.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D001441:Bacteroides fragilis / Q000187:drug effects; D002939:Ciprofloxacin / Q000031:analogs & derivatives* / Q000494:pharmacology; D004352:Drug Resistance, Microbial; D004755:Enterobacteriaceae / Q000187:drug effects; D016576:Fleroxacin; D005839:Gentamicins / Q000494:pharmacology; D006193:Haemophilus influenzae / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D009268:Nalidixic Acid / Q000494:pharmacology; D009643:Norfloxacin / Q000031:analogs & derivatives / Q000494:pharmacology; D015366:Pefloxacin; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins; D015366:Pefloxacin; D009268:Nalidixic Acid; D002939:Ciprofloxacin; D009643:Norfloxacin; D016576:Fleroxacin