BETA LACTAMASE SUSCEPTIBILITY PATTERNS AND PREVALENCE OF ESBL GENES IN UROPATHOGENIC Escherichia coli

Abstract

Escherichia coli is one of the main causes of urinary tract infections (UTIs). The pathogenic isolates are becoming increasingly resistant to antibiotics especially beta-lactam by their ability to produce extended-spectrum beta-lactamases (ESBLs). The aim of this study was to isolate E. coli from UTIs, and detection the antimicrobial resistance and its association with ESBL genes. CHROM agar Orientation medium was used for rapid detection of E. coli from urine specimens. According to phenotype of ESBL detection by Double Disk Synergy Test (DDST), eighty-four of E. coli isolates were ESBL producing. Polymerase chain reaction (PCR) was used for detection beta-lactamase genes (blaCTX-M, blaTEM and blaSHV). The percentage of ESBL-producing E. coli isolates was 57.5 %. The most frequent gene was blaTEM (82.1 %) followed by blaSHV (67.9 %) and blaCTX-M (34.5 %) genes. The most common ESBL genotype among our isolates was blaSHV and blaTEM (33.3 %). E. coli isolates that able to produce ESBL were susceptible to Meropenem and Imipenem, 94.1 % and 90.5 % respectively, and showed 100 % resistance to Amoxicillin, Cefotaxime and Cephalexin. The negative ESBL isolates exhibited high resistance to Amoxicillin and Cephalexin, and high sensitive to other antibiotic in comparison with the positive ESBL isolates. In conclusion, the most effective antibiotics against ESBL-producing uropathognic E. coli were carbapenems. The cephalosporins resistance is mainly due to ESBL production, where TEM-type gene was the most frequent among our local isolates. Study on ESBL producers among E. coli strains helps to control drug resistance cases and choose the right antibiotics for therapy of UTI.