Study On Biological Characteristics Of Duck-origin AIV And Sequencing And Sequence Analysis Of HA Gene And NA Gene

Avian influenza is caused by Orthomyxoviridae influenza A virus whichcan infect poultry diseases. It consists of8different RNA segments. The virus can causechicken, Turkey and other poultry and waterfowl, birds death. It also can infect human. The AIVhas many subtypes. The subtype is based on emagglutinin (HA) and neuraminidase (NA). TheHA has16subtypes and the NA has9subtypes. With different combination of HA and NA willform different subtypes AIV. Most of them have no pathogenicity or only lower pathogenicity. Alittle of them have strong pathogenicity. The H5N1, H9N2, H7N7subtype can infect the human.Experiments showed that some lower pathogenicity can not infect human, but it can changepower pathogenicity when it pass a period of time in the chicken, ducks and other poultry.The AIV has a wide distribution in the world. It has found in America Europe and othercountries and regions now. After it first found in China at1995, it will be isolated in each yearand it showed a normal trend. This study will analysis of physical and chemical and biologicalcharacteristics of a strain of H5N5subtype avian influenza virus of duck isolated in2010.Toprovide a theoretical basis for the prevention and control of avian influenza virus。This research through inoculated with AIV in egg isolated from a strain of H5N5subtype topurified virus. And to observe the morphology of virus by electron microscopy andPCR identified as avian influenza virus. The research study by physical and chemicalproperties, to the strains of virus biological characteristics, immunological characteristics. Theresults showed that the virus sensitive to acids, organic reagent without heat and can increase theactivity of trypsin. The virus could agglutinate red blood cells of various animal，and causeavian embryo infection. The strain of virus inactivated vaccine could induce antibodies. It cancounteract H5subtype influenza viruses，but it can not counteract H9subtype influenzaviruses.According to influenza virus sequence published in NCBI we design two pairs of primersfor HA gene and NA gene. The PCR products were purified and clone into pMD-18T. Theplasmid was transformed into E.coli DH5α. Extraction of plasmid andsequenced to bio-technology Company. The sequencing results were analyzed, sequenceanalysis and protein molecular characteristics analysis, prediction and analysis of signalpeptide, Tran membrane hydrophobic analysis, potential glycosylation and phosphorylation sites. We will provide a theoretical basis for the prevention and control of avian influenza virus.