Subunit Vaccine Efficacy Of Evaluation And Preliminary Study Of Colloidal Gold Strip For Fiber Protein Fowl Adenovirus Type 4 Of Group ?

Objective:The outbreak of chicken inclusion body hepatitis has been rised and manifested by pericardial hydrops caused serum type 4 and chicken inclusion body hepatitis since 2012.At present,there are few rapid diagnostic methods for type 4 antibody of avian adenovirus,and most traditional diagnostic methods are not only complicated to diagnose,but also can not be applied to production practice on a large scale.For the prevention and control of type 4 avian adenovirus,there is no licensed commercial avian adenovirus vaccine in China.Therefore,the truncated fibrin protein was used as an antigen and the efficacy was evaluated by immunizing animals with a laboratory-made subunit vaccine in this experiment,which could be a new method for effectively preventing and controlling the disease.The protein was used to prepare avian adenovirus test strips,which provided a new method for the subsequent diagnosis of avian type 4 adenovirus disease.Methods:The amino acid sequence containing the Fiber-2 antigenic protein determinant was obtained by screening for the Fiber-2 protein from amino acid 283 to amino acid 479,and then expressed and purified by E.coli prokaryotic expression system to obtain antigenic protein.The Fiber-2 antigen protein is emulsified with an adjuvant to obtain a subunit vaccine,and then the 3 week old SPF chicken is immunized,and the efficacy of the subunit vaccine is evaluated by an immunological challenge method and a serum neutralization method,and different periods after immunization and challenge.Blood collection for use.The colloidal gold test strip was prepared by using the immunochromatographic technique of the Fiber-2 antigen protein as an antibody detection method for avian adenovirus type 4.Results:After prokaryotic expression of type 4 FAd V,the concentration of Fiber-2 protein was 3269 ?g/mL,and the purity was over 90%.The results of immunoassay experiments showed that the minimum immunization dose of the Fiber-2 subunit vaccine could reach 2.5/feather and the protection rate was over 95%.The serum neutralization test showed that the serum neutralizing antibody titer of the chickens isolated after immunization could reach 1:1000;colloidal gold test strip experimental results show that the colloidal gold test strip prepared by the Fiber-2 antigen protein can specifically detect the antibody level of the chicken after the release of the Fiber-2 subunit vaccine,and the average value of the positive signal is maintained above 300.The control chickens had a mean signal between 10 and 50.Conclusion:The study-prepared Fiber-2 protein subunit vaccine has a good protective effect after immunizing chickens,and can protect chickens from virulent attacks.The immunogold gold strip of FAd V-2 protein was prepared preliminarily from this experiment.