Reduction of viral load of avian influenza A virus (H9N2) on SPF eggs and cell line by gamma irradiation

Avian influenza A H9N2 viruses are circulating in domestic poultry worldwide. In this research a low-pathogenic AIV H9N2 was multiplied on MDCK cell line and SPF eggs and irradiated by a Nordian gamma cell instrument. Irradiated and non-irradiated AIV samples were titrated by TCID50 and EID50 methods, respectively. Haemagglutinin antigen was analysed by Haemagglutinin test. Infectivi­ty of irradiated virus samples was determined by cell culture and egg inoculation methods. The virus titration decreased as the dose of gamma radiation increased. AIV proliferation on cell culture can be inactivated by gamma irradiation at a lower dose of gamma-ray (20 kGy) than the virus inactivation on embryonated eggs (30 kGy). The safety test showed complete inactivation of AIV on allantoic fluid with gamma-ray doses: 30 kGy and 20 kGy for virus on MDCK cells after four blind cultures.