Prevalence of Extended Spectrum Beta-Lactamase (ESBL) and O157- Producing <i>Escherichia coli</i> in broiler chickens in Abia State, Nigeria

Antimicrobial-resistant bacteria, including Extended Spectrum Beta-Lactamase (ESBL) and O157-producing Escherichia coli, pose significant challenges to public health and poultry farming. This study was aimed at determining the prevalence of Extended Spectrum Beta-Lactamase (ESBL) and O157-producing Escherichia coli among broiler chickens in Abia State, Nigeria. A total of 334 cloacal swab samples were collected from broiler birds across various local government areas (LGAs), including both farms (156 samples) and central markets (178 samples). Isolation and identification of E. coli were performed using standard microbiological techniques, followed by screening for ESBL production using the Double Disc Synergy Test (DDST) and O157 identification through the Latex Agglutination Test. The overall prevalence of E. coli was 80.8%, with a higher occurrence in market samples (86.5%) compared to farm samples (74.4%). Statistically significant (p=0.04) variability was observed across LGAs, with the highest E. coli prevalence in Aba South (95.2%) and the lowest in Umuahia North (63.3%). Among the isolates resistant to cephalosporins, 36 (43.9%) were confirmed as ESBL producers, with Ikwuano LGA exhibiting a 100% prevalence of ESBL-producing E. coli. Conversely, no resistance to third-generation cephalosporins was detected in Aba South, Aba North, and Bende. O157-producing E. coli was identified in only 4 isolates (4.9%), and all from Umuahia North. Antibiotic resistance profiling revealed that resistance was highest for cefotaxime (46.67%) and lowest for meropenem (8.89%). These findings highlight the considerable presence of antimicrobial-resistant E. coli in broiler birds in Abia State, underscoring the need for improved antibiotic stewardship and biosecurity measures to mitigate the spread of resistant strains.