Isolation And Identification And Biological Character Of Swine Ineluenza Virus And Cloning Analysis Of HA Gene

A swine influenza is a kind of common respiratory infectious disease around the world . It who is killed diffuctlly is recognized as a continuing theat to animal husbandy health. Swine influenza has a important infection in public sanitation. The biological character and the HA gene of 4 strains H3N2 SIV isolated , was studied in this article to control and defend SI.The four srtains separated are named as A/Swine/Henan/01/2008, A/Swine/ Henan /02/2008, A/Swine/Henan/03/2008 ,A/Swine/Henan/04/2008 . Serum subtype of the four srtains were identificated as H3N2 in the Harbin Veterinary Institute . NP gene of SIV were amplifiedthen cloned and sequenced by RT-PCR to analysis.Sequence analysis showed that the length of whole NP gene is 1565bp which enxodes 520 amino acids.The phylogenetic tree indicates that these virus have more relationship to classical H3N2 subtypes of HongKong swine influenza virus.The biological character of SIV was studied in this articl .The resuh indicatedthat is the virus hemagglutinin instabal, lectin spectrum in rabbits and chickens, the appeal of the thermal instabal, and a swine flu virus can grow in Vero cells , but the hemagglutinin is lower . influenza virus can infect mice,chichens and pigs.The virus are detected at the first five days and tenth days . antibody of HI is detected at the fifth ,tenth,fiftieth.The HA gene of H3N2 subtype swine influenza virus isolated was successfully amplified by RT-PCR and the sequence has been submitted in GenBank. Sequence analysis showed that the length of whole HA gene is 1753 bp which encodes 583 amino acids. there are 9 glucosylation sites totally, including7 in HAland 2 in HA2. There is no basic amino acid around the cleavage site and no characteristic of high pathogenic virus.The HA gene of this SIV isolate is most closely related to that of SIV strains isolated in Hongkong.