MECHANISM OF INHIBITOR ACTIVITY OF BOVINE SERUM ON THE GROWTH OF INFECTIOUS BURSAL DISEASE VIRUS
Yu Dahai Chen Guanchun Wang Xiaomei ( Harbin Veterirary Research Institute, Chinese Academy of Agricultural Sciences)
The mechanism of inhibitor of plaque formation of infectious bursal di-sease virus ( IBDV ) by calf serum ( CS ) was investigated. Inhibitor present in CS was absorbed by incubation of the serum with chicken embryo fibro-blast ( CEF ) , indicating the attachment of inhibitor to CEF. The amount of IBDV that was able to absorb to CEF decreased when the celis were pre-treated with CS. Suppression of IBDV plaque formation was also noted when CS was added to the agar overlay medium, indicating that the serum inhibited the spread of the virus infection to the surrounding celis. The inhibitory effect of CS was not due to a direct inactivation ( neutralization) of IBDV.The results indicated that the inhibitor in CS attaches to the sur-face of CEF and probably occupies the virus receptors of the celis, there fore blocking the absorptioa of the IBDV and reducing the plaque count.