Study On Duck Swollen Head Septicemia Virus Vaccine Immunity Response And Pathology

Duck Swollen Head Septicemia was an acute contagious virus disease recently in vogue, and it had the characters of swollen head, systemic septicemia, high incidence of disease and high mortality rate. Native vocation of duck breed was to the bad because of its prevalence. It was difficult to diagnose it for the reason that it was resemble between Duck Swollen Head Septicemia, Duck Plague and other duck epidemic disease, suck as clinic symptom, pathology change. And it were no potent immunity way to prevent the disease. It was the research developed an indirect ELISA method to detect the antibody of Duck Swollen Head Septicemia Virus, studied the ducks' immunity response to Duck Swollen Head Septicemia vaccine based upon it, and studied the pathology of duck embryos' infected Duck Swollen Head Septicemia Virus.First, the antigen of Duck Swollen Head Septicemia Virus was purified by Sephadex G-200 gel chromatography in this thesis.Then an indirect enzyme-linked immunosorbent assay (ELISA) was developed to detect the ducks' specific antibody to Swollen head Septicemia Virus. It suggested the optimum condition that the concentration of antigen was 6μg/ml, the blocking buffer was 2 per cent glutin, the sera dilution was 1:400, the conjugate dilution was 1:2000, and the discrimination level between positive and negative sera was set an optical density(λ =490nm) value of 0.44. The developing method of indirect ELISA was hypersusceptible, strongly specific and repeatable, had no crossing reaction with Duck Swollen Head Septicemia negative serum,duck Escherichia coli positive serum, Duck Plague positive serum, and Duck Hepatitis Viral positive serum. The result showed preferable repeatability to detect 4 Duck Swollen Head Septicemia positive serum, and the coefficient of variation was from 2.9 per cent to 5.0 per cent(<10%).