Antibiotic Resistance Profile and Microbiological Quality of Bacteria Isolated from Street-vended Smoked Fish Sold in Owo, Ondo State, Nigeria

Abstract

Antimicrobial resistance in ready-to-eat foods is an increasing food-safety concern, particularly where food processing and retailing occur under informal conditions. This study evaluated the microbiological quality and antibiotic resistance profiles of bacteria isolated from street-vended smoked fish sold in Owo, Ondo State, Nigeria. Nine smoked fish samples were obtained from three vending locations and analysed using standard microbiological procedures. Bacterial isolates were identified through conventional biochemical methods, while antimicrobial susceptibility was assessed using the Kirby–Bauer disc diffusion method. Total heterotrophic bacterial counts ranged from 0.00 to 7.00 × 10⁶ CFU/g, whereas enteric bacterial counts ranged from 0.00 to 6.00 × 10⁶ CFU/g. Four bacterial genera were identified: Pseudomonas spp., Staphylococcus spp., Proteus spp. and Micrococcus spp. Pseudomonas and Staphylococcus isolates were resistant to all antibiotics tested, whereas Proteus spp. were susceptible to all antibiotics tested. Micrococcus spp. showed resistance to Ampiclox and ciprofloxacin. The findings demonstrate that street-vended smoked fish may contain viable bacterial contaminants after processing and that antimicrobial susceptibility patterns differ among the recovered organisms. The observed variation across markets also indicates that post-processing handling and retail conditions may influence microbiological quality. Improved hygienic handling, routine microbiological surveillance and antimicrobial-resistance monitoring are therefore important for strengthening the safety of smoked fish sold to consumers.