AHRI report No.22

 Isolation And Characterization of Thymidine Kinase Deficient Mutants of Pseudorabies Virus

1. Taiwan Provincial Research Institute for Animal Health.
2. Central Veterinary Institute, Department of Virology, Lelystad, The Netherlands.

Three thymidine kinase-deficient (TK-) mutants from each local isolate, named p7, TNL and C2A, were obtained after passaging in PK cell and cloning 3 times in LTK-cell under the presence of BUdR. These TK mutants were safe to 6-8 weeks old Balb/C mice. Inoculated mice could resist challenge exposure with a virulent virus. Neither TK-mutant nor challenge virus was recovered. All mutants did not reverted to the TK-positive phenotype· in vitro.