Prevalence and association of the presence of blaTEM، blaSHV، and blaCTX-M beta-lactamase genes in multiple drug resistance (MDR) Uropathogenic Escherichia coli resistant and susceptible isolated from patients with urinary tract infections in Chalus

This study was performed to investigate the prevalence and association of blaCTX-M, blaTEM, and blaSHV beta-lactamase genes in multiple drug resistance (MDR) uropathogenic Escherichia coli resistant and susceptible isolated from patients with urinary tract infections in Chalus, Iran.

In the cross-sectional study a total of 437 samples were obtained from December 2018 to November 2019. Identification of Uropathogenic Escherichia coli strains was performed using standard microbiological and biochemical tests. Drug susceptibility to cefepime, ceftazidime, cefotaxime, cefixime, ceftriaxone, nalidixic acid, ciprofloxacin, trimethoprim, sulfamethoxazole, gentamicin, nitrofurantoin, and ampicillin was done by Kirby-Bauer disk diffusion method. Molecular identification of blaCTX-M, blaTEM و blaSHV was conducted by PCR (polymerase chain reaction) assay. The relationship between the presence of beta-lactamase genes in MDR strains was measured. Data analysis was performed using an appropriate statistical test.

It was observed that among the 437 positive urine culture samples of the patient, there were 106 UPEC strains (24.3%). The highest level of drug resistance was recognized toward ampicillin (99%), and the highest level of drug susceptibility was against cefepime (83%), and norfloxacin (82%). Multiple drug resistance (MDR) resistance was observed in 46 (43%) isolates. The blaTEM gene was more common among MDR-positive isolates (51.5%), and the blaCTX-M gene was more seen among MDR-positive isolates (65.8%).

Based on the present study results, the blaTEM gene was the dominant gene between beta-lactamase genes. Moreover, we found that the blaCTX-M gene's presence could be playing a role in MDR development.