Assay of the bacterial flora in the gut, gill and flesh of fresh catfish (Clarias gariepinus)

Abstract

This study was carried out to ascertain the bacterial flora in the gut, gill and flesh surfaces of fresh Clarias gariepinus purchased from four different markets located in Ota metropolis: Iyana-Iyesi, Oja-Ota, Oju-Ore and Sango-Ota. The fresh fish samples were randomly purchased from the markets and analysed using appropriate microbiological procedures. Bacterial isolates were identified based on colonial morphology, microscopy and biochemical tests. Analyses showed that the highest values of total bacteria counts (TBC) were 74.55 x 105 CFU/g in the gut, followed by that of the gill at 47.40 x 105 CFU/g and the flesh, 34.37 x 105 CFU/g; all from fresh C. gariepinus purchased from Oja-Ota market. There were five bacteria specie isolated from the gut, gill and flesh, namely Escherichia coli, Citrobacter spp., Salmonella spp., Shigella spp. and Proteus spp. The percentage occurrence of the bacteria species in the isolates indicated that Salmonella spp. had 36.4%, E. coli 27.3%, Citrobacter spp. 9.1%, Shigella spp. 18.1%, and Proteus spp. 9.1%. As a result of the presence of these pathogens in the fish; adoption of good fish culture standards, water quality and feeds, hygienic transportation and proper handling of fish by farmers and at the retail level by the vendors is highly recommended.