Antibacterial spectrum of a novel des-fluoro(6) quinolone, BMS-284756

The in vitro spectrum of a novel des-fluoro(6) quinolone, BMS-284756, was c ompared with those of five fluoroquinolones (trovafloxacin, moxifloxacin, l evofloxacin, ofloxacin, and ciprofloxacin). EMS-284756 aas among the most a ctive and often was the most active quinolone against staphylococci (includ ing methicillin-resistant strains), streptococci, pneumococci (including ci profloxacin-nonsusceptible and penicillin-resistant strains), and Enterococ cus faecalis. EMS-284756 inhibited approximate to 60 to approximate to 70% of the Enterococcus faecium (including vancomycin-resistant) strains and 90 to 100% of the Enterobacteriaceae strains and gastroenteric bacillary path ogens at the anticipated MIC susceptible breakpoint (less than or equal to4 mug/ml). Against the nonfermenters, EMS-284756 inhibited 90 to 100% of Pse udomonas fluorescens, Pseudomonas stutzeri, Stenotrophomonas maltophilia, F lavobacterium spp., and Acinetobacter spp. and 72% of Pseudomonas aeruginos a strains at 4 mug/ml. Against anaerobic bacteria, BMS-284756 was among the most active, inhibiting essentially an strains tested. It had very low MIC s against the fastidious and atypical microbial species, in particular agai nst mycoplasmas or ureaplasmas, Borrelia burgdorferi, chlamydia, and gonoco cci. These results indicate that with its broad antibacterial spectrum, BMS -284756 should be evaluated clinically for the treatment of community and n osocomial infections.