Clinical significance and spread of fluoroquinolone resistant uropathogens in hospitalised urological patients.

The minimum inhibitory concentrations (MIC) of ciprofloxacin were determined for 441 uropathogens from patients with complicated and/or hospital acquired urinary tract infections (UTI). None of the Enterobacteriaceae was resistant (MIC > or = 4 mg/l), but 21.7% of enterococci, 28.3% of Pseudomonas spp. and 38.5% of staphylococci were. Subtyping of the strains revealed that with staphylococci there was no clonal spread of resistant strains. In the case of enterococci and Pseudomonas spp., however, cross infections played a major role (46% and 40% respectively). In a retrospective analysis of 370 UTI episodes caused by Pseudomonas aeruginosa (74), enterococci (185) or staphylococci (111) there was no difference between sensitive and resistant strains with respect to clinical aspects and rates of elimination by appropriate anti-bacterial therapy. The rates of spontaneous disappearance without antibacterial therapy ranged from 28% in the case of P. aeruginosa up to 63% in the case of coagulase-negative staphylococci. This implies that especially in UTI caused by gram-positive cocci an indication for antibacterial therapy should be weighted thoroughly and fluoroquinolones should only be used in accordance with sensitivity testing.