title: In vitro activity of OPC-17116 compared to other broad-spectrum fluoroquinolones.
abstract: The in vitro activity of OPC-17116 was compared to that of five similar fluoroquinolones (ciprofloxacin, enoxacin, norfloxacin, ofloxacin and temafloxacin). A total of 700 isolates from recent cases of clinical bacteremia were tested. Fifty additional stock strains with well-characterized resistance mechanisms were also processed. The minimal concentrations inhibiting 90% of strains (MIC90) of Enterobacteriaceae species were for OPC-17116 0.015-0.5 micrograms/ml and for ciprofloxacin 0.015-0.25 micrograms/ml. Moraxella catarrhalis, Haemophilus influenzae and Neisseria gonorrhoeae were very susceptible to OPC-17116 (MIC90 0.015 micrograms/ml) thus being fourfold more active than ciprofloxacin. For all beta-hemolytic streptococci and pneumococci OPC-17116 MICs were less than or equal to 0.5 micrograms/ml. The most resistant enteric bacilli were among the Citrobacter freundii and Providencia rettgeri strains (MIC90 0.5 micrograms/ml). Pseudomonas aeruginosa strains were comparably susceptible to OPC-17116 (MIC90 0.5 micrograms/ml). Low pH and CO2 incubation had an adverse effect on OPC-17116 MICs, and resistance development was documented among current clinical isolates of staphylococci, pseudomonas and some Enterobacteriaceae.
authors.affiliation: Department of Pathology, University of Iowa College of Medicine, Iowa City 52242.
authors.forename: H S
authors.initials: HS
authors.lastname: Sader
authors.forename: M E
authors.initials: ME
authors.lastname: Erwin
authors.forename: R N
authors.initials: RN
authors.lastname: Jones
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D004353:Drug Evaluation, Preclinical; D004352:Drug Resistance, Microbial; D024841:Fluoroquinolones; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D009154:Mutation / Q000235:genetics; D010879:Piperazines / Q000494:pharmacology*; D015363:Quinolones / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D010879:Piperazines; D015363:Quinolones; C075375:grepafloxacin