Abstract:Experiments were carried out to evaluate the influences of inactivated Nocardia seriolae on the nonspecific immune indexes of Channa argus. One hundred healthy fish (C. argus) at body weight of 300~400 g were divided randomly into immunized and control groups. Each individual in the immunized group was intraperitoneally injected with 0.5 ml 1.0×108CFU/ml N.seriolae which was inactivated by formalin and ultrasonic disruption, while each individual was intraperitoneally injected with 0.5 ml sterile saline solution in the control group. After the injection, blood samples were taken from the fish caudal vein on days 0, 3, 6, 9, 12, 15, 18, and 21 to test the changes of nonspecific immune indexes such as haematocyte number, serum total protein, alkaline phosphatase(AKP), acid phosphatase(ACP), superoxide dismutase(SOD) and lysozyme activities. The results showed that haematocyte number in immunized C. argus increased at first and was significantly higher than that in control group on day 12, but then decreased. Content of serum total protein of the immunized C. argus was significantly higher than that in the control group on day 9. Alkaline phosphatase (AKP), acid phosphatase (ACP), superoxide dismutase (SOD) and lysozyme activities showed significant changes during the experiment. All these findings indicate that inactivated N. seriolae may enhance the non-specific immunity of C. argus, producing a significant protection against the pathogen bacteria.
