Systematic Veterinary Virology

LABORATORY DIAGNOSIS

Isolation and identification

• Lung tissues are the ideal material for isolation of virus. The supernatant from the lung tissue homogenates are used for infecting the cell culture system or embryonated eggs. The preferred cell culture systems for virus growth are Madin–Darby canine kidney (MDCK), swine kidney, swine testicle or swine lung epithelial cell lines. Specific cytopathic effects appear 7 days of incubation. The virus can also be isolated in embryonated eggs (9-11 days old). The presence of the virus are confirmed by
• Haemagglutination test: This test is performed using 0.5% chicken or male turkey red blood cells. The HA activity is confirmed by HI test using specific serum (8HA units of virus are used unlike HA test for NDV)
• Neuraminidase inhibition test
• Fluorescent antibody test
• Immunoperoxidase test
• Antigen capture ELISA
• Polymerase chain reaction