Prevalence and antibiotic resistance pattern of extended spectrum beta lactamase producing Escherichia coli isolated from urinary tract infection

Abstract

Introduction: Urinary tract infection (UTI) due to extended spectrum beta-lactamase (ESBL)-producing bacteria including Escherichia coli has become widespread. Studies have shown a trend toward higher mortality, longer hospitalization, greater hospital expenses and reduced rates of clinical and microbiologic response in ESBL UTI. Objectives: The aim of this study is to determinate the prevalence and antibiotic resistance pattern of ESBL producing E. coli isolated from UTI. Patients and Methods: This cross-sectional study was conducted on 3126 samples. Urine specimens were cultured on Eosin Methylene Blue (EBM) and blood agar. The disk diffusion standard method (Kirby Bauer) was used to test the susceptibility of the drug on Muller- Hinton agar plates and results were reviewed based on Clinical and Laboratory Standards Institute (CLSI) criteria. The reviewing of ESBL-producing uropathogens was carried out using Combined Disk Test (CDT) by using cefotaxime (CTX; 30 μg) and cefotaximeclavulanic acid (CTX; 30 μg /CA:10 μg) disks and CLSI protocol. Results: Out of 291 E. coli isolates, 108 (37.11%) are ESBL-producer and 183 (62.89%) are non-ESBL-producer. Among ESBL-producing E. coli, the highest antibiotic resistance was observed with cefotaxime (100%), amoxicillin (97.22%) and piperacillin (96.3%) and the highest antibiotic sensitivity was observed with meropenem (93.5%), nitrofurantoin (81.48%) and gentamicin (55.56%). Conclusion: We recommended that cephalosporins, penicillins and cotrimoxazole are not suggested in the treatment of ESBL-producing E. coli. On the other hand, carbapenems as a first line and aminoglycosides as the next step in the treatment of ESBL-producing E. coli are recommended.