EVALUATION OF ANTIBIOTIC RESISTANCE PATTERNS IN E. COLI ISOLATED FROM POULTRY AND ITS PHARMACOLOGICAL IMPLICATIONS

Abstract

Background: Multidrug-resistant (MDR) and extended-spectrum β-lactamase-producing (ESBL) Escherichia coli threaten empirical treatment of urinary tract and bloodstream infections in Pakistan. Poultry and human clinical isolates show high resistance but lack contemporaneous comparison in Lahore. The extent of overlapping resistance patterns remains unclear. This study compares MDR/ESBL prevalence across sources.

Research Design and Methods: This cross-sectional observational study (STROBE-compliant) assessed 180 E. coli isolates from 5 poultry farms/slaughterhouses and 3 microbiology laboratories in Lahore, Pakistan (Jan–Jun 2025). Eligible unique isolates (n=120) underwent CLSI-standardized Kirby-Bauer disk diffusion or microdilution susceptibility testing. Primary endpoint: isolate-level MDR (nonsusceptibility to ≥1 agent in ≥3 classes) and ESBL (phenotypic confirmation). Secondary: resistance genes (blaTEM/SHV/CTX-M, mcr-1) via PCR subset, farm antibiotic/biosecurity via questionnaire. Multivariable logistic regression adjusted for specimen type/laboratory. No blinding/follow-up.

Results: Of 180 assessed, 120 were analyzed (72 poultry [60%], 48 human clinical [40%]; 100% completion). Poultry: mostly cloacal (53%), carcass swabs (47%); human: urine (67%), blood (33%). Primary: MDR 62.5% (95% CI 50.7–73.3%; poultry) vs 50.0% (35.9–64.1%; human), adj OR 1.65 (0.82–3.31), p=0.16; ESBL 41.7% (30.5–53.5%) vs 37.5% (24.2–52.2%), adj OR 1.22 (0.61–2.44), p=0.57. High resistance: ampicillin 83%/73%, ciprofloxacin 69%/60%. Genes (MDR/ESBL subset n=80): blaCTX-M 52%/60%. No adverse events (non-interventional).

Conclusions: In Lahore, poultry and human E. coli exhibited comparably high MDR/ESBL prevalence, compromising first-line empirical therapy. Safety not applicable. Limitations: modest sample, cross-sectional design, single-city. Findings support One Health stewardship; larger genomic studies needed for transmission causality.