Extended spectrum beta-lactamase (ESBL) production and antibiotic resistances of Escherichia coli and Klebsiella spp. strains isolated from urine cultures

Objective: It was aimed to determine extended spectrumbeta-lactamase (ESBL) production and antibiotic resistancerates of Escherichia coli and Klebsiella spp. strainsisolated from urine cultures of patients admitted to variousoutpatient clinics and inpatient clinics of our hospitalbetween December 2011 and August 2012.Methods: E.coli and Klebsiella spp. strains isolated fromurine cultures were identified by conventional methods.Antibiotic susceptibilities were determined by using Kirby-Bauer’s disk diffusion method according to Clinical andLaboratory Standards Institute (CLSI) recommendations.Extended spectrum beta-lactamase (ESBL) producingE.coli and Klebsiella spp. strains were detected by using“double disk sinergy method”.Results: During the study period, 308 E.coli and 54 Klebsiellaspp. strains were isolated from urine cultures. ESBLproduction was detected in 64 (20.8%) of E.coli strainsand 21 (38.9%) of Klebsiella spp. strains. ESBL positivitywas encountered the most frequently in urine samples ofpatients who were from outpatient clinics of pediatrics andurology, it was followed by internal clinics and intensivecare units. Imipenem resistance was found to be 4.7%and amikacin resistance was 7.8% in ESBL-positiveE.coli strains. There was no resistance to carbapenemsin ESBL-positive Klebsiella spp. strains, but their amikacinresistance was 4.8%. Piperacillin tazobactam resistancerate in ESBL-positive E.coli and Klebsiella spp. was17.2% and 14.3%, respectively.Conclusion: Selection of antibiotics should be made byconsidering results of antibiotic susceptibility tests fortreatment of urinary tract infections. Also, determinationof ESBL production and reporting it with antibiotic susceptibilitytests will enhance the success of treatment. J ClinExp Invest 2013; 4 (1): 56-62Key words: Escherichia coli, Klebsiella spp., antimicrobialsensitivity tests, ESBL, urinary tract infection.