Institution: | a Department of Microbiology-104, Bristol-Myers Squibb Company, 5 Research Parkway, Wallingford, CT 06457, USA b Department of Biostatistics and Data Management, Bristol-Myers Squibb Company, Wallingford, CT, USA |
Abstract: | MICs of gatifloxacin and ciprofloxacin against 3482 pre-treatment, clinical trial isolates collected during 1997–1998 are reported. These data suggested that gatifloxacin was four- to eight-fold more active than ciprofloxacin against Gram-positive bacteria, with gatifloxacin MIC90s≤0.33 mg/l against Staphylococcus aureus and Streptococcus pneumoniae, and ≤1.0 mg/l versus viridans streptococci and Enterococcus faecalis. Both quinolones had similar MIC90s versus Enterobacteriaceae (generally ≤0.38 mg/l, except 0.7–0.8 mg/l for Citrobacter freundii) and Pseudomonas aeruginosa (8 mg/l). A total of 78% P. aeruginosa had gatifloxacin MICs ≤2 mg/l. Gatifloxacin was more active than ciprofloxacin against Acinetobacter species and non-P. aeruginosa pseudomonads. Both had exceptional activity versus Haemophilus spp, Moraxella catarrhalis and Neisseria gonorrhoeae. In summary, compared to ciprofloxacin, gatifloxacin had improved activity against Gram-positive bacteria and comparable activity against Gram-negative bacteria. |