DETECTION OF BLATEM GENE IN ESCHERICHIA COLI ISOLATED FROM CLINICAL SAMPLES

Abstract

Background: UTIs are one of the most common bacterial infections seen in clinical settings and antimicrobial resistance has become more of a therapeutic challenge. One of the most important cause of UTI is uropathogenic Escherichia coli and β-lactam production called extended-spectrum β-lactamase (ESBL) may significantly decrease the effectiveness of β-lactam antibiotics. blaTEM is a relevant determinant that is related to resistance to β-lactam antibiotics and has been found in clinical Enterobacteriaceae strains. As far as Pakistan is concerned the distribution of this gene on the UTI associated isolates is still limited.

Objective: The objective of this study was to determine the prevalence of blaTEM-mediated antimicrobial resistance and characterize the antimicrobial susceptibility pattern of Escherichia coli isolates recovered from urine samples of patients with urinary tract infections (UTIs) in tertiary-care hospitals in Lahore, Pakistan.

Methods: A total of 52 Escherichia coli isolates were recovered from urine samples of UTI patients attending tertiary-care hospitals in Lahore, Pakistan. The isolates were cultured and identified using MacConkey and Eosin Methylene Blue (EMB) agar. Antimicrobial susceptibility testing was performed against 24 antibiotics using the Kirby–Bauer disk diffusion method. Genomic DNA was extracted by heat lysis, and conventional PCR was employed to detect the blaTEM β-lactamase resistance gene. PCR products were visualized by agarose gel electrophoresis. The association between blaTEM gene detection and patient gender was assessed using the chi-square test.

Results: The blaTEM gene was detected in 14 of 52 (26.9%) E. coli isolates, while 38 (73.1%) were negative. The prevalence of blaTEM-positive isolates was higher among females (11/29; 37.9%) than males (3/23; 13.0%), with a statistically significant association between gender and blaTEM detection (p = 0.04). Most isolates were obtained from patients aged ≤20 years (24/52; 46%), followed by those aged 21–40 years (12/52; 23%) and 61–80 years (10/52; 19%), while 4 (7.6%) were aged 41–60 years; age data were unavailable for two patients. High resistance rates were observed against cefuroxime (90%), ampicillin (88%), nitrofurantoin (87%), and cefotaxime (82%).

Conclusion: The study identified blaTEM-mediated resistance in uropathogenic Escherichia. coli, with high resistance to broad-spectrum cephalosporins and ampicillin, particularly among female patients. These findings highlight the need for continuous molecular surveillance and judicious antibiotic use to support effective treatment and minimize antimicrobial resistance and therapeutic failure.