GENETIC ANALYSIS OF CARBAPENEMASE-PRODUCING BACTERIA CAUSING URINARY TRACT INFECTIONS IN REPRODUCTIVE-AGE FEMALES OF LAHORE

Abstract

Background: Carbapenemase-producing uropathogens represent a critical public health challenge, especially among women of reproductive age who are predisposed to recurrent urinary tract infections (UTIs) due to hormonal, anatomical, and behavioral factors. In high-burden regions such as Pakistan, the growing dissemination of extended-spectrum β-lactamases (ESBLs) and carbapenemase determinants significantly limits therapeutic options, necessitating molecular-level investigations to inform targeted interventions and antimicrobial stewardship programs.

Objective: The study aimed to determine the genetic distribution of ESBL and carbapenemase genes, specifically blaTEM, blaSHV, blaCTX-M, blaIMP, and blaVIM, in uropathogens isolated from reproductive-age females in Lahore, Pakistan.

Methods: A total of 100 non-duplicate bacterial isolates were obtained from culture-confirmed UTIs in female patients aged 18–45 years. Demographic data were stratified by age groups, with emphasis on the reproductive-age cohort. Antimicrobial susceptibility testing was performed using standard disc diffusion and broth microdilution methods against β-lactams, aminoglycosides, fluoroquinolones, carbapenems, and colistin. Molecular screening was conducted via PCR to detect ESBL genes (blaTEM, blaSHV, blaCTX-M) and carbapenemase genes (blaIMP, blaVIM).

Results: The highest burden of UTIs was found in women aged 31–59 years (70%), including 40% from the reproductive-age group. Escherichia coli was the most prevalent isolate (62%), followed by Klebsiella oxytoca (22%), K. pneumoniae (10%), Pseudomonas aeruginosa (4%), and Citrobacter freundii (2%). Overall antimicrobial susceptibility was low (19%), with colistin showing the highest retained activity (83%), while resistance to cephalosporins and fluoroquinolones exceeded 85%. Molecular screening revealed universal presence of blaTEM (100%), high prevalence of blaCTX-M (94%) and blaSHV (84%), and notable detection of blaIMP in 39% of isolates. In contrast, blaVIM was rarely observed (1%).

Conclusion: This study underscores the co-existence of ESBL and carbapenemase determinants among UTI pathogens in reproductive-age women, with blaIMP emerging as a dominant carbapenemase allele. The findings highlight the urgent need for enhanced molecular surveillance, rapid diagnostics, and context-specific stewardship measures to curb the spread of multidrug-resistant uropathogens in Pakistan.