Comparative in vitro activity of the new quinolone gemifloxacin (SB-265805) with other fluoroquinolones against respiratory tract pathogens

The in vitro activity of gemifloxacin (SB-265805) was compared with that of other fluoroquinolones against 302 clinical isolates of Streptococcus pneu moniae, 300 clinical isolates of Haemophilus influenzae and 28 clinical iso lates of Moraxella catarrhalis, including multiply resistant strains, Gemif loxacin at 0.12 mg/L inhibited all microorganisms tested. MIC50 values of g emifloxacin, trovafloxacin, grepafloxacin and levofloxacin against all (630 ) isolates tested were 0.03, 0.12, 0.12 and 1 mg/L, respectively, MIC90 val ues of the same fluoroquinolones against S. pneumoniae were 0.06, 0.25, 0.1 2 and 1 mg/L, respectively.