Isolation and identification of pathogenic bacteria from fresh fish organs

Abstract

Aquaculture products can harbor pathogenic bacteria which are part of the natural microflora. Microbial pathogens associated with fish can be transmitted to human that uses the fishes as source of food or handling. This study aimed to isolate human pathogenic bacteria present in the gills, gut and skin of apparently healthy fishes. Tilapia (Clarias lazera) and Oreochromicniloticus (Cat fish) were collected from Gombe main market and Dadin-kowa of Gombe state. Bacteria were isolated from the fish skin, gill, and gut. Identification of the bacteria was conducted using biochemical tests on specific culture media. Different pathogenic bacteria were isolated from the fish species which appeared yellow or white in colour, small with pin head, while some are circular and irregular that spread all over the media.. The isolates were higher from Dadin-kowa samples compared to Gombe main market. The total bacteria count value ranges between 1.01 x 103 to 1.50 x 103 for the tilapia fish and 1.04 x 103 to 2.20 x 103 cfu/ml for cat fish. The identification results revealed that Staphylococcus aureus and Eshcherichia coli was the most abundant pathogenic bacteria. Presence of Staphylococcus aureus and Eshcherichia coli is attributed to contamination of the fish samples by man through handling and processing. These enteric bacteria from the fishes indicated the organisms faecal contamination and/or water pollution, as well, represents a potential hazard to humans’ life.