Antimicrobial activity of DW286 against Streptococcus pneumoniae

DW286 is a novel broad-spectrum fluoroquinolone with excellent antipneumococcal activity. The in vitro activity of DW286 was evaluated against quinolone-susceptible and -resistant Streptococcus pneumoniae and was compared with the activities of reference compounds. Among the tested agents, DW286 showed the most potent antibacterial activity against 94 quinolone-susceptible strains [minimum inhibitory concentration (MIC) 0.008–0.03 mg/L]. Against 23 quinolone-resistant S. pneumoniae with known resistance mechanisms, DW286 also had the lowest MICs of all the tested quinolones [MIC at which 90% of isolates were inhibited (MIC90) = 0.5 mg/L], followed by ciprofloxacin, sparfloxacin, moxifloxacin and gemifloxacin. The in vivo activity of DW286 against penicillin-susceptible and -resistant S. pneumoniae was more effective than that of gemifloxacin.