Goose QY12H9N2Subtype Avian Influenza Cirus Strain Biological Characteristics

Avian influenza virus, H9N2subtype, caused worldwide pandemic in the nature, wild poultry, bird is the main hosts, H9N2subtype avian influenza virus can be generally isolated in the poultry farms. It is a remarkable fact that the waterfowls, are the repository of the influenza viruses.Waterfowls are contribution to the avian influenza, the avian influenza virus of waterfowls and swine play the important in the avian influenza epidemic.under normal circumstances, the incidence of death can not be caused by only the H9N2subtype avian influenza virus infected, the caused of poultry deaths is extremely by the other viruses infected. humans can also be infected by H9N2subtype avian influenza virus. Therefore, the biological characteristics of the H9N2subtype avian influenza virus to be researched, not only has important academic significance, but also an important public health significance. In this essay, the experiment virus A/Goose/Guangdong/QY12/2010A (H9N2)(referred to as QY12strain) were isolated from the the dead goose organs from Qingyuan County, Guangdong Province. The pathogenic, antigenic differences and molecular genetic evolution of the QY12strain were be researched in this essay. The main ideas is to understood and grasped the biological the characteristics of the H9N2subtype avian influenza virus from the goose of, as well as the law of the genetic evolution, and so to control of the H9N2subtype avian influenza prevention.The50%embryo infective dose (EID50), mean dead time (MDT) and intravenous pathogenicity index (IVPI) have been conducted, in order to demonstrate the pathogenicity of QY12strain in this experiment. And the result of the IVPI was (0.05<1.2), and the EID50was10-3.36, and the MDT was124.8h, it is showed that the QY12strain was the low pathogenic strains; the10-day-old chicks, ducklings and goslings was infected by QY12strain from fresh infectious and intramuscular injection of0.4mL (105.76EID50), the results showed that the QY12strain was the low pathogenic strain. This experiment analyzes the antigenic analysis between the e the QY12strain and A/Chicken/Beijing/1/94A (H9N2) strain, the results show that the QY12strain was no significant difference in the antigenic variation.