A laboratory assessment of ciprofloxacin and comparable antimicrobial agents

The in vitro activity of ciprofloxacin against a wide range of bacterial isolates was assessed in comparison with norfloxacin, enoxacin, co-trimoxazole and penicillin (or ampicillin) where appropriate. Minimal inhibitory concentrations (MICs) indicated that ciprofloxacin was highly active against gram-negative bacilli of the Enterobacteriaceae and Pseudomonas groups, notably against strains resistant to gentamicin. Similarly, Staphylococcus aureus (including methicillin-resistant strains) and Haemophilus influenzae were susceptible, regardless of penicillinase production. Norfloxacin and enoxacin were less active than ciprofloxacin against the majority of species tested, although enoxacin blood levels were generally higher. Most co-trimoxazole-resistant strains were susceptible to the quinoline group of drugs.