Lomefloxacin, a new difluoroquinolone: in vitro activity against gram-positive and gram-negative bacteria.

The in vitro activity of lomefloxacin, a new difluoro-quinolone, was compared to other antimicrobial agents against a selection of Gram-positive and Gram-negative organisms. Against the Enterobacteriaceae, the lomefloxacin MIC inhibiting 90% of strains was less than or equal to 0.5 micrograms/ml. Ninety per cent of Pseudomonas aeruginosa and Acinetobacter sp. isolates were inhibited at less than or equal to 4 micrograms/ml. All staphylococci including methicillin-resistant organisms were susceptible at 1.0 micrograms/ml. Enterococcus faecalis, Listeria spp., and sero Group B streptococci were more resistant with an MIC90 of 8, 16 and 4 micrograms/ml, respectively.