The comparative activity of norfloxacin with other antimicrobial agents against Gram-positive and Gram-negative bacteria.

Norfloxacin (MK0366) displayed appreciable activity against the great majority of Gram-negative and Gram-positive bacteria. The minimum inhibitory concentration for 90% of isolates (MIC90) of the Enterobacteriaceae was 0.5 mg/l or less while for Campylobacter, Neisseria, Haemophilus MIC90s were 0.25 mg/l or less. Norfloxacin was also among the most active drugs tested against methicillin susceptible and resistant Staphylococcus aureus, Staph. epidermidis, enterococci and Pseudomonas aeruginosa with MIC90s between 0.5 and 4 mg/l.