Screening for Extended-Spectrum Beta-Lactamase Producing Escherichia coli in Poultry Farms in Ogun State

The emergence of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in livestock settings represents a critical One Health concern, with potential spillover to human populations through food chains and environmental contamination. This study screened for ESBL-producing E. coli in commercial poultry farms across three local government areas in Ogun State, Southwest Nigeria. Cloacal swabs were collected from 200 broiler chickens across ten farms, and E. coli isolates were identified using standard biochemical tests. ESBL phenotypic screening was performed using the combined disc diffusion test with cefotaxime and cefotaxime-clavulanic acid. Confirmatory genotypic detection of blaTEM, blaSHV, and blaCTX-M genes was performed by multiplex PCR. Of 180 E. coli isolates obtained, 52 (28.9%) were phenotypically ESBL-positive. Molecular analysis confirmed blaCTX-M-15 as the predominant gene type, consistent with global trends. The high prevalence of ESBL producers on farms with unrestricted antibiotic use suggests that prophylactic antibiotic practices in poultry agriculture are contributing to resistance gene dissemination. The study recommends regulatory enforcement of veterinary antibiotic prescription policies in Ogun State. Keywords: ESBL, Escherichia coli, poultry, blaCTX-M, Ogun State.