In vitro Activity of Enoxacin versus Ciprofloxacin, Fleroxacin, Lomefloxacin, Ofloxacin, Pefloxacin, and Rufloxacin against Uropathogens

Abstract

Minimum inhibitory concentrations (MIC) of enoxacin, ciprofloxacin, fleroxacin, lomefloxacin, ofloxacin, pefloxacin and rufloxacin were determined against 400 uropathogens cultured from the urine of patients with complicated and/or hospital-acquired urinary tract infections (UTI) using an agar dilution method. The bacterial spectrum consisted of Enterobacteriaceae (34.5%), enterococci (31.5%), staphylococci (21.2%) and non-fermenting bacteria (12.8%). Enoxacin inhibited all but one strain (Enterobacter cloacae) of Enterobacteriaceae up to an MIC of 1 mg/l (MIC₉₀ 0.25 mg/l). Regarding the total bacterial spectrum, enoxacin inhibited 54.5, 59.5, 76.0 and 83.8% up to an MIC of 1, 2, 4 and 8 mg/l, respectively. If the same breakpoint of resistance for ofloxacin according to DIN 58 940 (NCCLS), i.e. MIC ≥4 mg/l (≥8 mg/l), is also taken for the other fluoroquinolones, and the 126 strains of enterococci are excluded, for which alternative agents, e.g. aminopenicillins, should be considered instead, the following resistance rates were found: ciprofloxacin and enoxacin 15.3% (15.0%), ofloxacin 17.2% (15.3%), pefloxacin 18.2% (15.3%), fleroxacin 19.3% (15.3%), lomefloxacin 19.7% (17.9%) and rufloxacin 31.8% (27.4%). According to their in vitro activity, all fluoroquinolones tested besides rufloxacin show similar rates of resistance against uropathogens and can therefore be considered good alternative agents for the treatment of complicated UTI.