Henderson L M, Katz J B, Erickson G A, Mayfield J E
National Veterinary Services Laboratories, Science and Technology, USDA, Ames, IA 50010.
Am J Vet Res. 1990 Oct;51(10):1656-62.
Pseudorabies virus (PRV), an alpha-herpesvirus, causes substantial economic losses in the swine industry and is currently the focus of eradication and control programs. Some of these programs rely on the ability of veterinarians to differentiate animals exposed to virulent strains of PRV from animals exposed to avirulent vaccine strains of PRV on the basis of a serologic response to nonessential glycoproteins that are deleted in some vaccine strains of PRV. Genetic recombination resulting in the creation of virulent strains of PRV with the same negative immunologic markers as vaccine strains could disrupt these programs. Two strains of PRV were coinoculated either into tissue culture or into sheep to facilitate recombination. Progeny viruses were selected to detect a specific recombinant phenotype. We were able to detect genetic recombination between vaccine strains of PRV following in vitro or in vivo coinoculation of 2 strains of PRV. The selected recombinants had marker-deleted phenotypes in strains with restored virulence genes. Increased virulence was observed in sheep after coinoculation of 2 avirulent vaccine strains of PRV.
伪狂犬病病毒（PRV）是一种α疱疹病毒，在养猪业中造成重大经济损失，目前是根除和控制计划的重点。其中一些计划依赖兽医根据对某些PRV疫苗株中缺失的非必需糖蛋白的血清学反应，将接触强毒株PRV的动物与接触无毒疫苗株PRV的动物区分开来的能力。导致产生具有与疫苗株相同阴性免疫标记的强毒株PRV的基因重组可能会扰乱这些计划。将两株PRV共同接种到组织培养物或绵羊体内以促进重组。选择子代病毒以检测特定的重组表型。在体外或体内共同接种两株PRV后，我们能够检测到PRV疫苗株之间的基因重组。所选重组体在具有恢复毒力基因的菌株中具有标记缺失表型。在共同接种两株无毒PRV疫苗株后，在绵羊中观察到毒力增加。
