Dynamics of urinary tract infections: a comprehensive study on antimicrobial susceptibility, virulence profiling and molecular epidemiology of uropathogenic Escherichia coli from Pakistan.

Background: Urinary tract infections (UTIs), primarily caused by Escherichia coli, pose a global health challenge owing to rising antimicrobial resistance (AMR), particularly carbapenem-resistant (Carb-RT) and extended-spectrum beta-lactamase (ESBL)-producing uropathogenic E. coli (UPEC). This study analyzed AMR trends, virulence determinants, and molecular epidemiology of UPEC isolates from community and hospital settings in Pakistan.

Methods And Results: A total of 2700 urine samples were screened in this study. UPEC isolates underwent antimicrobial susceptibility testing, PCR screening for ESBL/carbapenemase genes (bla, bla, bla, and bla), virulence factor detection, and multilocus sequence typing (MLST) of Carb-RT strains. Among the 390 UPEC isolates, third-generation cephalosporin resistance was higher in hospital (80.2%) than in community (37.9%) strains. Carbapenem resistance varied between community-acquired (CA-UTI: 7.4%) and hospital-acquired (HA-UTI: 34.2%) infections. The ESBL genes included bla (53.3%), bla (39.7%), and bla (13.35%), while bla accounted for 89% of carbapenem resistance. Virulence profiling showed the prevalence of adhesion genes fimH(89.5%), papC (74.4%), and papG (58.5%), iron acquisition markers iutA (66.4%) and fyuA (50%), and capsule gene kpsMTII (60%). The hemolysin gene hlyA was detected in 66.7% of isolates. MLST identified sequence types ST405 (19%), ST10 (18%), ST101 (18%), and ST131 (13%). bla was associated with major STs, except ST8051, indicating clonal resistance spread.

Conclusions: The high prevalence of Carb-RT UPEC with ESBLs and virulence genes in Pakistan poses a public health threat. The dominance of ST405 and ST131 highlights the need for genomic surveillance. These findings advocate for revised empirical therapies to combat AMR in healthcare and community settings.