MOLECULAR CHARACTERISATION AND ANTIBIOTIC RESISTANCE PROFILING OF FOODBORNE BACTERIAL PATHOGENS FROM CAMPUS FOOD OUTLETS IN POLYTECHNICS IN SOUTH-WEST NIGERIA

Abstract

Foodborne bacterial disease remains a major public-health burden, and ready-to-eat (RTE) foods are a recognised vehicle for pathogens where hygiene is inadequate. This study isolated, molecularly characterised and profiled the antibiotic resistance of foodborne bacterial pathogens from campus food outlets in polytechnics in South-West Nigeria. An experimental laboratory design was used. RTE foods and food-contact surface swabs were collected from purposively selected outlets, isolates
were cultured on selective media and confirmed by 16S rRNA sequencing, and susceptibility was tested by Kirby-Bauer disc
diffusion. A total of 60 food samples and 40 surface swabs yielded 142 isolates: Escherichia coli (28.2%), Klebsiella pneumoniae (18.3%), Staphylococcus aureus (16.9%), Salmonella spp. (12.7%), Shigella spp. (9.9%), Pseudomonas aeruginosa (7.7%) and Listeria monocytogenes (6.3%). Multidrug resistance occurred in 62.4% of isolates, highest in E. coli (78.6%) and K. pneumoniae (72.3%). Resistance was most frequent against amoxicillin-clavulanate (83.3 to 92.5% across species), tetracycline (66.7 to 82.5%) and co-trimoxazole (66.7 to 77.5%). Resistance genes detected included blaTEM (68.4% of E. coli), blaCTX-M (42.1%), tetA (57.9%) and sul1 (63.2%). Campus food outlets harbour multidrug-resistant pathogens, including WHO highpriority organisms, which supports food safety and antimicrobial stewardship interventions.