title: In vitro antibacterial activity of norfloxacin (MK-0366).
abstract: The in vitro activity of norfloxacin (MK-0366) compared with that of beta-lactam antibiotics and, where appropriate of gentamicin or metronidazole was assessed against recent clinical isolates of common bacteria. The compound was highly active against most enterobacteria (minimal inhibitory concentrations [MICs], 0.008 to 32 micrograms/ml; 90% inhibited by 0.25 micrograms/ml), Haemophilus influenzae (MICs, 0.03 to 0.12 micrograms/ml), and Neisseria gonorrhoeae (MICs, 0.008 to 0.016 micrograms/ml). It was also active against Pseudomonas aeruginosa (MICs, 0.12 to 2 micrograms/ml), most other pseudomonads (MICs, 0.03 to 32 micrograms/ml), and Acinetobacter calcoaceticus (MICs 0.06 to 4 micrograms/ml). Norfloxacin was somewhat less active against staphylococci (MICs, 0.25 to 4 micrograms/ml; 1 microgram/ml required to inhibit 50% of isolates) and streptococci (MICs, 0.5 to 64 micrograms/ml). Members of the Bacteroides fragilis group of anaerobes were relatively resistant to norfloxacin (MICs, 8 to 128 micrograms/ml), as were most other anaerobes.
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D009268:Nalidixic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D009643:Norfloxacin; D013210:Staphylococcus / Q000187:drug effects; D013291:Streptococcus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D009268:Nalidixic Acid; D009643:Norfloxacin