Quality of the Seafood in Southern Nigeria with References to Microbial Loads and Trace Metals in Citharidium ansorgii, An Endemic Fish Species

Abstract

Background and Objective: Trace metals may contaminate food sources and accumulate the agricultural product and seafood through water, air soil pollution, contamination of soil may further pose risks to human health through direct ingestion with the food chain. Hence, the microbial loads and heavy metals concentrations in Citharidium ansorgii, one of the most common fish species in Southern Nigeria were investigated to ascertain its health status. Materials and Methods: Sampling was done monthly and a total of 36 fish samples were randomly purchased from fishmongers in six major markets in the region. Bacteriological isolates were analyzed using standard bacteriological procedures, while standard identification keys and atlas were used in identifying fungal isolates. The trace metals were analyzed using the atomic absorption spectrophotometer (G105 UV-VIS). Results: The total bacteria population of C. asorgii from the markets varied from 8.40-43.10 CFU gG 1 . The fungi count ranged from 3.80-18.20 CFU gG 1 . The bacteria isolates were, Micrococcus species, Klebsiella pneumonia, Enterococcus species, Bacillus cereus, Staphylococcus albus, Actinomycetes species, Enterobacter aerogenes, Pseudomonas species, Salmonella species, Listeria monocytogenes, Yersinia species, Proteus species, Shigella species, Chromatium species. Klebsiella pneumonia, Staphylococcus albus, Shigella species and Salmonella species had the highest frequency of occurrence. The fungi isolated were Aspergillus flavus, Fusarium species, Rhizopus stolonifera, Mucor species and Trichophyton species. A. flavus, Fusarium species and Trichophyton species had the highest frequency of occurrence. The concentration ranges of the metals were, Cu, 1120-3540 µg gG 1 dw, Zn, 2250-7420 µg gG 1 dw, Cd, 1.60-600 µg gG 1 dw and Pb, 7.80-7.20 µg gG 1 dw and were above the standard limits prescribed by regulatory bodies. Conclusion: The pathogenic microorganism and heavy metals detected in the endemic fish in this region can pose serious health hazards to consumers as they are not safe for human consumption, an observation that calls for regular monitoring of the kinds of seafood in this region.