PHENOTYPIC ISOLATION AND CHARACTERIZATION OF EXTENDED SPECTRUM BETA-LACTAMASES (ESBLS) IN ESCHERICHIA COLI ISOLATES FROM (MAMMY MARKET, ABAKPA) ABATTOIR

Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli represents a growing threat in the fight against antimicrobial resistance, particularly in low-resource environments where animal-human-environment interactions are poorly regulated. Abattoirs are critical hotspots for the emergence and spread of such resistant strains. This study assessed the prevalence and phenotypic profile of ESBL-producing E. coli from the Mammy Market abattoir in Abakpa, Enugu State, Nigeria. Eight environmental and animal-contact surface samples were aseptically collected from the abattoir. Isolation and identification of E. coli were performed using MacConkey and EMB agar, followed by biochemical tests. Antimicrobial susceptibility was assessed using the agar well diffusion method. The antibiotics used included Ceftazidime, Ceftriaxone, Cefotaxime (all third-generation cephalosporins), and Piperacillin/Tazobactam. Interpretation of susceptibility results was done according to Clinical and Laboratory Standards Institute (CLSI) guidelines. All eight samples yielded E. coli isolates. Seven out of the eight isolates (87.5%) demonstrated reduced susceptibility to the tested antibiotics, suggesting ESBL production. Zones of inhibition were notably smaller in suspected ESBL producers, particularly with cefotaxime and ceftazidime. These findings highlight a serious public health concern, with potential for zoonotic and foodborne transmission of resistant bacteria. These findings call for urgent implementation of antimicrobial stewardship, routine surveillance, and improved hygiene practices within abattoir settings to mitigate the spread of resistance at the animal-human-environment interface.