Microbial Profile of Smoked Fish Sold in Selected Markets in Ibadan Metropolis, Oyo State, Nigeria

Aim: Smoked fish is a widely consumed food and protein source prepared in various cultures around the world. The aim of this study was to determine microbial load of smoked fish sold in select markets in Ibadan, Oyo State.

Methodology: A total of 36 samples of 4 different fish species; Mackerel (Scomber scombrus), Sardine (Sardinela eba), Panla (Gadus morhua) and Cat fish (Clarias gariepinus) were sourced from three different market locations. Three pieces of whole smoke-dried fish samples of each of these four species was collected at three different markets. These samples were purchased from Taska market, Adelabu market, and Molete market, all situated in Ibadan Metropolis.

Results: The study identified microorganisms; Listeria monocytogenes (15%), staphylococcus aureus (15%), Vibrio paraheamolyticus (10%), Salmonella sp. (15%), Pseudomonas sp. (15%), Aeromonas sp (15%)., and Escherichia coli (15%) from the samples. The presence of these bacteria pose a health risk as some of them have been reported in previous studies as hazardous for human consumption. The Multiple Antibiotics Resistance (MAR) Index of bacterial isolates showed some isolates displayed high resistance (e.g., Listeria monocytogenes with a MAR Index of 1.0) and others showing lower resistance levels (e.g., Vibrio parahaemolyticus and Salmonella sp., both with a MAR Index of 0.1).

Conclusion: The presence of these bacteria in smoked-fish sample is a cause for concern because it suggests that the fish is contaminated with pathogenic bacteria that have survived the smoking process. Caution should be exercised in consuming smoked-dried fish displayed openly, reheating and prolonged cooking may be necessary to deactivate such micro-organisms before consumption.