Activities of newer fluoroquinolones against Shigella sonnei.

The activities of six fluoroquinolones were determined for 117 separate strains of Shigella sonnei. The order of increasing activity (MICs for 90% of strains tested) was enoxacin (0.25 micrograms/ml), temafloxacin (0.032 micrograms/ml), sparfloxacin (0.016 micrograms/ml), CI-960 (0.008 micrograms/ml), ciprofloxacin (0.008 micrograms/ml), and PD-131628-2 (0.008 micrograms/ml). These data, along with results of killing and mutational rate studies, showed that all six fluoroquinolones were highly inhibitory against S. sonnei and five fluoroquinolones were rapidly and persistently bactericidal.