Comparative in-vitro activity of Ro 23-6240, a new trifluorinated quinolone.

The in-vitro activity of Ro 23-6240, a new quinolone, was tested in comparison with that of other quinolones against 486 recent clinical isolates. Ro 23-6240 displayed the typical features of the new quinolones: highest activity against Gram-negative bacilli, MBCs close to the MICs, minimum inoculum effect and rapid killing. Against Gram-negative organisms (Enterobacteriaceae, non-fermenters, Haemophilus influenzae and gonococci) the activity of Ro 23-6240 was between that of ofloxacin and norfloxacin; against staphylococci its activity was between that of ciprofloxacin and ofloxacin, and against streptococci it was similar to that of norfloxacin.