Prevalence and Antibiotic Resistance Pattern of Escherichia coli Isolated from Urine Samples of Pediatric Outpatients with Underlying Medical Conditions from Pakistan.

BACKGROUND: Urinary tract infections (UTIs) caused by Escherichia coli pose a significant health burden in children, particularly in those with underlying medical conditions. The emergence of antimicrobial resistance, including extended-spectrum β-lactamase (ESBL) production and multidrug resistance (MDR), complicates treatment strategies. Data on resistance patterns in this vulnerable population remain limited in low-income and middle-income countries. METHODS: To determine the prevalence and antibiotic resistance patterns of E. coli isolated from urine samples of pediatric outpatients (1-12 years old) with underlying medical conditions. This hospital-based cross-sectional study was conducted at the Pakistan Institute of Medical Sciences (January 2022-January 2023). Urine samples were collected from 941 pediatric outpatients with documented underlying conditions. E. coli were identified biochemically and molecularly. Antimicrobial susceptibility testing was performed using Kirby-Bauer disc diffusion, with ESBL screening and confirmation. RESULTS: E. coli was detected in 30.08% (283/941) of samples, which was significantly higher in females than in males (38.1%, p <0.001). ESBL production was detected in 30.4% (86/283) of the isolates and MDR isolates in 18.7% (53/283). The highest rates of resistance were observed against ampicillin (70.3%), cephalexin (60.1%), and trimethoprim-sulfamethoxazole (59.4%). Low resistance was noted to nitrofurantoin (2.8%) and amikacin (1.8%). Age was a significant predictor, with 1-year old children showing 2.1-fold 95% CI: 1.01-4.55) and 3.6‑fold (95% CI: 1.60-8.15) increased odds of ESBL production and MDR, respectively, compared to children aged 6-12 years. CONCLUSION: High rates of ESBL-producing and MDR E. coli in Pakistani children with underlying conditions underscore the critical need for antimicrobial stewardship and empirical therapy guided by local susceptibility patterns, particularly in younger children.