Abstract:
The main objectives of this study was to determine the presence of Pathogenic bacteria species Counted and isolated, identified pathogenic bacteria in O. niloticus and C. gariepienus, and which organ(s) was more susceptible to bacterial infection. Six fish samples were collected randomly three Nile tilapia O.niloticus and three catfish C.gariepienus from fish hatchery, all fish were weighed using sensitive balance, then External observations on fish were also performed. Samples were inoculated medium were observed for the presence of bacterial growth after 24 hours incubation. the bacterial colonies present were sub-cultured onto (MckA) medium and incubated at 30 C in an incubator for 24 hours. Data were analyzed by SPSS version 2.1 The result from this research shows that the bacterial abundance varies in the six segments of the fishes analyzed, the skin, gills, gonad, spleen, liver and viscera. The bacterial occurrence in all sample was high (salmonella, 30.5, Psdomonus 11.1 , Protieus 8.3 and E.coli 0.0, 8.3) in tilapia and catfish respectively.