incidence of fluoroquinolone resistance in pseudomonas aeruginosa from urinary tract infections

The susceptibility of 105 Pseudomonas aeruginosa isolates collected from patients with urinary tract infections was assessed by determination of minimum inhibitory concentration (MICs) using agar dilution method against the following agents: norfloxacin, ofloxacin, ciprofloxacin and pefloxacin. Resistance rates of P. aeruginosa to tested fluoroquinolones was fairly uniformly distributed between compounds as followed: norfloxacin - 52.4%, ofloxacin- 49.5%, ciprofloxacin - 51.4%, pefloxacin - 49.5%. Analysis of cross-resistance in P. aeruginosa showed a correlated magnitude of resistance between fluoroquinolones. Among the P.aeruginosa strains the number of those showing simultaneously resistance to all tested agents is high (n=50). The significant increase in fluoroquinolone resistance probably reflects the widspread use of this agent and the clinical use of these compunds should be carefully monitored since most bacterial strains shows cross-resitance.