Bacteriological Analysis of Nile Tilapia Fish (Oreochoromis niloticus)

Fish is a major food in great demand throughout the world. Fish protein is better and safer than meat (animal protein) because it contains lower cholesterol. A research was conducted to analyze the bacterial habitat and content of Tilapia fish. Total seven fishes were taken. The samples were examined in microbiology laboratory by serial dilution method. Sections of the skin, gills and intestine of fishes were aseptically removed by means of a sterile scalpel and pair of sterile scissors. A serial dilution was prepared and from last dilution 0.1ml was plated on nutrient agar plates. Total eighteen different species of bacteria were isolated and identified. Gram negative include Pseudomonas sp. and Enterobacter sp., while gram positive species include Staphylococcus aureus and Streptococcus sp. Some of these pathogens have tendancy to transmit to man (who eat fish meat or deal with fish and fish products). Streptococcus infection was detected in high prevalence among cultured fresh water fishes, especially during summer seasons. The most common signs of Streptococcosis in fish were septicemia, skin ulcers, hemorrhages of the eye, in some cases changed cloudy and destructed (pop –eye) and hemorrhages on the skin especially in the base of fins and tail. Hence it is considered that a variety of bacterial species can be associated with fresh Tilapia fish related pathogen to humans