Extended-Spectrum β-Lactamase-Producing Escherichia coli and Klebsiella spp. in Community-Acquired Urinary Tract Infections and Their Antimicrobial Resistance

Objective: Production of extended-spectrum beta-lactamases (ESBLs) is the most important antimicrobial resistance mechanism among Gram-negative pathogens. In this study, ESBL frequency and antimicrobial resistance of Escherichia coli and Klebsiella spp. isolated from community-acquired urinary tract infections (UTIs) are investigated. Methods: In this retrospective cross-sectional study, ESBL rates and the results of antimicrobial susceptibility tests were determined for E. coli and Klebsiella spp. grown in the urine cultures of 520 patients with community-acquired UTI, and the changes in the antimicrobial resistance rates of the isolates were compared in terms of ESBL production. Results: E. coli had grown in 220 samples and Klebsiella spp. in 38 samples. ESBL production frequencies of the isolates were found as 40% and 47.4%, respectively, and the rate of carbapenem resistance was found as 3.1%. Among the isolates, the highest resistance was found for amoxicillin-clavulanate (46%), ciprofloxacin (44.9%), and ceftriaxone (42.2%), while the lowest resistance was found for colistin (0.3%), fosfomycin (1.5%), amikacin (3.1%), and nitrofurantoin (4.2%). In ESBL-producers, significantly higher resistance was found for all antibiotics studied, except colistin, nitrofurantoin and fosfomycin. Conclusions: In this study, it was shown that almost half of the community-acquired isolates were ESBL-producers, and these isolates had acquired resistance against many antimicrobials including the last resorts such as carbapenems and colistin. To reduce the progress of resistance rates in E. coli and Klebsiella spp. which are the most common pathogens in community-acquired UTIs, their therapies should be planned according to the results of susceptibility tests as much as possible.