Development Of Detected Antibody Method Of Porcine Reproductive And Respiratory Syndrome

PRRS was first reported in the United States in1987,Our country also found that the disease in1996.Now has become one of the most widely popular all over the world pig disease, caused huge losses to the pig breeding industry, so it is particularly important to the diagnosis and prevention of the disease.There are many methods to detect this disease.The detecting of the antibodies includes EILSA IFA、IPMA and SVN; The detecting of the antigens includes PCR and the real time PCR. Compared to the other methods,ELISA is simpler to perform,time-saving, sensitive and suitable for large scale surveys of PRRSV infection and is useful to evaluate the efficiency of various vaccines against PRRSV.PRRSV is a small envelope virus replicase encoded by ORF1containing ORF1a and ORF1b,virus envelope glycoprotein GP2,GP3,GP4and GP5encoded by ORF2-5respectively/virus unglycosylated membrane protein M encoded by ORF6and highly conserved nucleocapsid protein N encoded by ORF7.GP5protein is the major glycoprotein and protective antigen with molecular weight of25KD.There are six antigenic determinants on gp5,which can induce the neutralizing antibody to neutralize the virus infection in vitro.Meanwhile,GP5is also a multifunctional protein and the strongest capability in PRRSV,which takes part in cellular immunity and humoral immunity.Thus,GP5protein has an important significance in pathogenicity,diagnosis,prevention and control of PRRSV,and is also the most powerful candidate gene for genetic engineering vaccine.This experiment successfully constructed pGEX-6P-1-GP5prokaryotic expression vector, and using E.coli expression system to make efficient target protein expression, get the size of about42kDa recombinant protein;With recombinant GP5protein as envelope antigen, established the detection of PRRSV serum antibody ELISA kit.With recombinant GP5protein as envelope antigen, established the detection of PRRSV serum antibody ELISA kit.Kits are in line with the research, compare GP5-ELISA and IDEXX kit test results, the immune serum coincidence rate was98.67%, the infection serum coincidence rate was94.1%, show that PRRSV serum antibody detection kit has the very high sensitivity and specificity.