Antimicrobial activity of advanced-spectrum fluoroquinolones tested against more than 2000 contemporary bacterial isolates of species causing community-acquired respiratory tract infections in the United States (1999)

In vitro activity of four newer fluoroquinolones (clinafloxacin, gemifloxacin, moxifloxacin, sitafloxacin) and an equal number control drugs in the same class (ciprofloxacin, grepafloxacin, levofloxacin, trovafloxacin) was determined by reference dilution tests against 2156 recent United States clinical isolates of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. All the fluoroquinolones demonstrated excellent in vitro activity against these pathogens. Streptococcus pneumoniae isolates were fully susceptible to clinafloxacin, sitafloxacin, and gemifloxacin at 0.5 microg/ml, and over 98% of sampled strains had MICs of