Swine Influenza Virus Isolation And Identification: Cloning And Analysing Of The HA Gene And Serological Studies

Swine influenza is a highly infectious respiratory disease caussed by Swine Influenza Virus affecting swine of different stages, sexes and breeds. Swine influenza was first reported in U.S.A in 1918. Shope isolated and identified H1N1 subtype swine influenza from swine in 1930. The disease results economic lose and threats animal husbandry and human health . At present, it widely takes place in many nations and regions in the world. The research of swine influenza has become a hot topic nowadays.Swine influenza broken in our courtry in 2002. Our laboratory carried out isalation and identification from collected clinical samples. Three SIV H3 subtype strains were identified using standard diagnostic methods. Besides biological characterizations were studied to these virus. These isolates can agglutinate red blood cells coming from different animals, but their hemagglutinin were not stable. These isolates were sensitive to physical and chemical factors, but were strongly resistant to dry and cold. These isolates are highly infectious to chicken embryo. These mice and pigs experimently infected with swine influenza displayed classic respiratory syndromes and visible pathology. The swine influenza virusThe full HA 1 gene was amplified by RT-PCR with primers designed spefic to conserved Haregion . The results indicated that three swine influenza had highly homogalar sequences with H5 subtype avian influenza virus. Meantime the result showed that fujian isolate belongs to the same branch as AIV.Indirect Enzyme-Linked Immunosorbent Assay (ELISA) of SIV was Established for diagnose SIV. The best work condition was done, meantime speficity and reproducibility test were carried out. The result indicated SIV ELISA we established has good speficity and reproducibility, and can be applied to diagnose swine influenza.The results indicated that our nation had existed and prevailed swine influenza, that swine influenza had become serious disease through our assay method which had been established.With the increasing danger of multi-infection, the Serological study was be done. The results showed swine influenza and PCV or APP have highly infectious percent, though swine influenza and PRRS had lowly infectious percent.