Objectives: Extended spectrum beta-lactamases (ESBL), are enzymes which can hydrolise cephalosporins and monobactams and usually responsible for resistance to beta-lactam antibiotics in Gram negative bacilli. The presence of ESBL in Escherichia coli strains isolated from urine samples in a State Hospital, was investigated and the sensitivity of these strains to some antibiotics was examined.
Materials and methods: E. coli strains isolated from urinary cultures were identified by conventional methods. Antimicrobial susceptibility tests have been studied by using “Kirby-Bauer disk diffusion method”. Extended Spectrum β-Lactamase producing E. coli strains have been detected by using “double disk synergy test”.
Results: In this study, the prevalence of ESBL producing isolates among E. coli was found to be 13%. The antimicrobial resistance rates of ESBL positive strains to many antibiotics which were not substrate for these enzymes were found higher than those of ESBL negative strains (p<0.05).
Conclusion: Since resistant strains isolated from urinary tract infections frequently show multiple resistances, selection of antibiotic should be made by considering results of antibiotic susceptibility tests in treatment. Determination of ESBL production and reporting antimicrobial susceptibility testing will be important for enhancing the success of treatment.