Incidence of Extended-Spectrum β-lactamases ESBLs producing Escherichia coli in patients with urinary tract infection

Abstract

Two hundred seven isolates of Escherichia coli were isolated from urine samples collected from patient suffering from UTI obtained from Al-Diwaniya Teaching Hospital. During the period from March 2011 to May 2012, a total of 2000 urine samples were collected from patients with suspected UTI. Identification according to the traditional biochemical tests, then confirmed by VITEK 2 system. Detection of ESBLs by using initial screening and confirmatory test which carry out by disk approximation or double disk synergy test (DDS) and CHROMagar methods, showed that 186 (89.8%) / 207(100%) of E. coli were initially screened as positive for ESBL. CHROMagar CTX technique was the most 166 (80.2%) ambient method than the disk approximation or (DDS) 0(0.0%) tests regarding confirmation of ESBL production. The results revealed that Screening and confirmatory tests considered the most accurate method for detection of ESBL- producing isolates, while the disk approximation was not accurate method in detecting such enzymes. The results of PCR assay showed that, 50 (100%) and 49 (98.0%) of the blaCTX-M positive isolates harbored blaSHV and blaOXA genes, respectively. While, blaTEM, blaPER, blaVEB and blaGES genes were not detected in this investigation.