Assessment of Bacterial Contamination in Farmed Catfish and Wild Caught (Clarias gariepinus) (Burchell, 1822) and Water Sources in Zaria, Nigeria

Abstract

Catfish (Clarias gariepinus), obtained from both cultivated farms and natural environments serves as an important source of protein in Nigeria. Nevertheless, the presence of bacterial contamination in both fish and aquatic habitats presents considerable risks to public health. Evaluating the microbial quality of both farmed and wild catfish, as well as their water sources in Zaria is crucial for ensuring food safety and mitigating the threat of waterborne diseases. This study therefore, aimed at assessing the bacterial contamination levels in water and fish (Clarias gariepinus) from selected dams and fish farms in Zaria, Nigeria, and identified the bacterial species present. Water and fish organ samples (kidney and liver) were analyzed for bacterial and coliform counts over 12 months using standard culture methods. Results revealed significant variations in bacterial (0.35x105- 10.65x105) and coliform (0.8x104-9.0x104) counts across months and sampling sites, with farm water samples exhibiting higher contamination levels than dam water. For the fish organs, however, the bacterial contamination rate of dam fish samples was higher (12.62x105) than the farm fish samples (8.75x105). Pathogenic bacteria were isolated from water and fish samples, including Staphylococcus aureus, Escherichia coli, Salmonella typhi, and Klebsiella pneumoniae. The findings reveal the public health risks associated with consuming contaminated fish and emphasize the need for improved water quality management and good food safety practices in the region.