Assessment of Bacteriological Quality of Freshwater Fish Sold in Retail Markets in Ibadan, Oyo State

Food safety risks associated with bacteriologically contaminated fish are a growing public health concern in urban markets across South West Nigeria, where hygienic handling practices remain inconsistent. This study assesses the bacteriological quality of fresh and smoked Clarias gariepinus and Oreochromis niloticus sold in three major retail markets in Ibadan, Oyo State. A total of 72 fish samples, 18 per species per processing method, were collected over three months. Surface swabs and gill tissue samples were analysed for total viable count, coliform count, Escherichia coli, Staphylococcus aureus, Salmonella species, and Listeria monocytogenes using standard microbiological procedures. Results revealed that fresh fish samples had significantly higher total viable counts than smoked fish, with 52% of fresh samples exceeding the ICMSF recommended limit of 10^7 CFU/g. Escherichia coli was detected in 38% of fresh samples and 12% of smoked samples. Salmonella species were isolated from 14% of fresh catfish gills. Listeria monocytogenes was absent in all smoked samples but detected in 8% of fresh samples. Market conditions, including absence of refrigeration, open display on unclean surfaces, and poor hand hygiene among vendors, were documented as contributing factors. The study provides evidence for mandatory bacteriological quality standards and hygiene training programmes targeting fish vendors in Ibadan urban markets.

Keywords: bacteriological quality, fresh fish, smoked fish, market hygiene, Ibadan