This a study was conducted in Khartoum State, Sudan to detect the causative agents of bacterial fish septicaemia (Aeromonas spp. and Pseudomonas spp.) and their prevalence in three seasons of years (Winter, Summer and Autumn). A total of 35 fish samples ;19 Oreochromis niloticus and 16 Clarias sp., were collected from Jabal Awalia dam and Elshagera localities (river Nile) and from Elshagara Fish Research Center farm in the period from December 2012 to June 2013. The samples were taken from gills, skin, intestine, liver, stomach and kidney. The experiment was conducted in the institute of Veterinary Research Institute, Bacteriology Department, Suba, Khartoum State. Different methods of identification were used for the identification of the isolates including conventional methods and rapid identification system by using API 20NE kits Strips. Statistical analysis of the obtained results revealed high significant differences between the seasons of the year (P < 0.01), different organs (P < 0.01) and significant differences between Oreochromis niloticus and Clarias sp. (P < 0.05 > 0.01) in the abundance of Aeromonas spp. The results also viewed that Pseudomonas spp. were not detected in all samples investigated in two species in all seasons throughout this study.
