Frequency of TEM and PER Beta-Lactamase Genes in Urinary Isolates of Escherichia Coli Producing Extended-Spectrum Beta-Lactamases

recent years, increase in extended-spectrum β-lactamases (ESBLs) producing Escherichia coli has led to limitations of treatment options. This study aimed to find the frequency of blaTEM and blaPER genes among ESBL producing urinary isolates of E. coli and detect their resistance pattern.

From January 2016 to February 2017, 972 urine samples from patients suspected of having urinary tract infections in three main hospitals and laboratories in Karaj were collected. Bacterial identification, antimicrobial susceptibility and ESBL production were performed according to the standard guidelines. Polymerase chain reaction was used for the detection of TEM and PER -lactamases.

This study was approved by the Research Ethics Committee of Islamic Azad University of Tehran Medical Branch (Code: IR.IAU.TMU.REC.1396.274).

Out of 972 samples, 500 cases were culture-positive for E. coli. Thirty-six percent (n =180) of the isolates were determined as ESBL-producer. Among ESBL positive isolates, the most susceptibility was observed in amikacin and imipenem (80 and 60% respectively). Resistance to trimethoprim/sulfamethoxazole,ciprofloxacin, tetracycline and gentamicin was 92.7%, 78.9%, 66.1% and 57.8%, respectively. All ESBL producers exhibited multidrug resistance. Among the ESBL-positive isolates, blaTEM gene was detected in 44.72% (n=85) of the isolates, but the blaPER gene was not found in any of the isolates.

The prevalence of multidrug resistant ESBLs producing uropatogenic E. coli is high. Continues monitoring of ESBL producers and their resistance patterns can help to reduce the spread of such resistant strains in the community.