In vitro activity of gemifloxacin and contemporary oral antimicrobial agents against 27,247 Gram-positive and Gram-negative aerobic isolates: a global surveillance study

This study was a multi-centre, multi-country surveillance of 27,247 Gram-positive and Gram-negative isolates collected from 131 study centres in 44 countries from 1997 to 2000. MICs of gemifloxacin were compared with penicillin, amoxicillin-clavulanic acid, cefuroxime, azithromycin, clarithromycin, trimethoprim–sulphamethoxazole, ciprofloxacin, grepafloxacin and levofloxacin by broth microdilution. Penicillin resistance in Streptococcus pneumoniae was extremely high in the Middle East (65.6%), Africa (64.0%) and Asia (60.4%) and lower in North America (40.3%), Europe (36.9%) and the South Pacific (31.8%). Macrolide resistance in S. pneumoniae was highest in Asia (51.7%) but varied widely between laboratories in Europe (26.0%), North America (21.6%), the Middle East (13.7%), the South Pacific (10.6%) and Africa (10.0%). All the study quinolones were highly active against penicillin-resistant and macrolide-resistant S. pneumoniae. Overall, gemifloxacin had the lowest MIC 90 at 0.06 mg/l with MICs 4–64-fold lower than ciprofloxacin, levofloxacin and grepafloxacin against S. pneumoniae. Gemifloxacin MICs were more potent than grepafloxacin>levofloxacin>ciprofloxacin against the Gram-positive aerobes and shared comparable Gram-negative activity with ciprofloxacin and levofloxacin.