Establishment Of VP3-ELISA And NS2-ELISA For Detection Of Goose Parvovirus And Detection For The Antibody Dynamics

Goose Parvovirus infection also known as Gosling Plague or Derzsy's disease, Mainly infect 4-day-old to 20-day-old domestic goslings and Muscovy duckings.It's can cause chordapsus and also liver, kidney, heart and other organs septic lesions, particularly the fibrous of the small intestine. The short course of the disease, rapid transmission, and a high mortality rate, causing serious economic losses, it's one of the important infectious diseases of goose cultural industry. The disease spread every year in different degree that hinder the healthy development of goose cultural industry, requires an accurate and convenient diagnostic method for diagnosis.The genomes of GPV contain two main open reading frame (ORF), encoding structural proteins and non-structural proteins. VP3 protein is a mainly structural proteins and highly conservative. VP3 protein which is the major components of virus nucleocapsid and accounting for about 80% of total protein and the main structural protein of goose parvovirus, exposes to the virus particle surface. It can be used as candidate gene to construct gene engineering recombinant vaccine.NS2 protein as a non-structural protein mainly involved in viral DNA replication and regulation of gene expression. The research in non- structural protein is less and we have found in Western blot assays that recombinant NS2 protein can recognized by the sera of geese infected with GPV. So we select structure protein VP3 and non- structure protein NS2 as antigen.Recombinant plasmid pET-30a-NS2 was constructed according to recombinant plasmid pGEX-6p-NS2. Then the recombinant plasmid was transferred into E. coli expression system to express GPV-NS2 protein. The positive recombinant plasmid pET-30a- VP3 is correct. Purified by Ni+-NTA Agarose, NS2 protein and VP3 protein were used as antigens to establish of two indirect ELISA detection methods, and theirs optimal reactive conditions were determined. Experimental immune serum antibodise of goose parvovirus have been tested by the VP3-ELISA and NS2-ELISA detection method. The results showed that the antibodies against VP3 at the fifth week after vaccination reached its peak, and the antibodies levels decreased slightly later. Antibodies against NS2 at the fourth week reached a peak, maintained at a relatively high level until the fourteenth week. Compared with the antibodies against VP3 and the antibodies against NS2, the antibodies against NS2 reaches its peak one week earlier than the antibodies against VP3, and fluctuates obviously.In this study, we established the VP3-ELISA and NS2-ELISA detection methods, and detected the antibodies against goose parvovirus especially antibodies against non-structural protein. The work is founder to monitoring for the rapid diagnosis of disease Gosling, disease surveillance, epidemiological investigation and immune antibody titer determination. The added advantage of using recombinate NS2 as the antigen ia that it might be able to discriminate between infected and vaccinated goose when recombinant capsid protein (VP2 and VP3) is used as the vaccine.