Interference between Variants of Pseudorabies Virus demonstrable in Tissue Culture

Abstract

THE results of a series of investigations dealing with the cytopathogenic activity of pseudorabies virus have recently been reported from this Institute¹. In these studies a strain of pseudorabies virus was serially transferred in tissue suspensions derived from chick embryos, and these served as a source of virus for the experiments. Destructive effects of the virus on tissue cultures made from fragments of embryonic chicken heart were recorded, and the cytopathogenic titre of virus material was used as a measure of its activity. Our present experiments have demonstrated that the virus became modified in its cytopathogenic activity for chicken cells by passages carried out in tissue suspensions of mouse embryo. The change in cytopathogenicity set in after four or five serial transfers of the virus in this tissue suspension. The characters of virus materials serially passed in suspensions of chicken and mouse embryonic tissue respectively are given in Table 1.