MULTICENTER IN-VITRO COMPARATIVE-STUDY OF FLUOROQUINOLONES AGAINST 25,129 GRAM-POSITIVE AND GRAM-NEGATIVE CLINICAL ISOLATES

In vitro activities of fleroxacin, ciprofloxacin, ofloxacin, and lomef loxacin were evaluated against 25,129 fresh bacterial isolates from 51 US hospital or medical center laboratories, beginning in October of 1 990. Susceptibility rates were greater than or equal to 85% against ma st species of Gram-negative bacteria. Notable exceptions were Pseudomo nas, Acinetobacter, Xanthomonas, and Providencia. The study drugs disp layed similar activity against most Gram-negative species. At least 90 % of oxacillin-susceptible staphylococci were susceptible but, of oxac illin-resistant strains, only approximately 60% of Staphylococcus epid ermidis and 25% of Staphylococcus aureus were susceptible to the quino lones tested. Staphylococcus saprophyticus strains were less susceptib le to fleroxacin (42%) than to the other compounds (79%-97%). Ofloxaci n and ciprofloxacin were more active against streptococci, and none of the compounds demonstrated appreciable activity against enterococci. Thus, the spectra of activity of fluoroquinolones illustrate that they remain effective agents for the treatment of many types of infections caused by Gram-negative pathogens.