[Analysis of anti-microbial resistance of Escherichia coli that caused infection in urogenital system].

ABSTRACT

OBJECTIVE: To study the anti-microbial resistance of Escherichia coli (E.coli) that caused infection in urogenital system. METHOD: Anti-microbial susceptibility tests for 148 strains of E.coli were conducted by disc diffusion technique. RESULTS: In 28 commonly used antibiotics, the resistance rates of E. coli to beta-lactam and quinolones were high (73.6%-86.4%). High resistance rates to the first- and the second-generation cephalosporin (cefradime, cephazolin and cefaclor) were also observed (44%). Resistance rate to ceftazidime is the lowest (10.1%) in the third-generation cephalosporin. The resistance rates of E. coli to piperacillin, pefoperazone and ampicillin were 84.5%, 44.6% and 83.0% respectively. Combined antibiotic and beta-lactam inhibitor gave lower resistance rates than antibiotic alone (piperacillin/tazobactam, cefoporazone/sulbactam and ampicillin/sulbactam were 4.1%, 10.8% and 52.0% respectively, P<0.01). Of 148 E. coli isolates, 38 strains were capable of yielding extended-spectrum beta-lactamases (ESBLs) (25.7%), 110 strains were not able to produce ESBLs (74.3%) and the resistance rates of isolates with ESBLs to 28 antibiotics were significantly lower than those of isolates without ESBLs. CONCLUSION: Antibiotic/beta-lactam inhibitor and nitrofurantoin are effective for urogenital infections caused by E. coli.