The VP1/2 Protein of a New Recombinant PRV Strain Promotes the Infectivity and Pathogenicity of PRV in Northeastern China

Pseudorabies virus (PRV) is an acute infectious disease characterized by neurological and respiratory symptoms. In order to have a better understanding of the current prevalence of PRV in northeastern China, a strain of PRV was isolated by us. Then, protein structure analysis and pathogenicity testing of the virus were performed to give insight into the characterization of the isolated PRV strains. In this study, the PRV strain named CH/HLJPRVJ/2023 was isolated and identified. Genome-wide phylogenetic analysis shows CH/HLJPRVJ/2023 and HeN1 have higher homology. The CH/HLJPRVJ/2023 strain had the highest homology with HeN1 strain (97.3%) and the lowest homology with Bartha-K61 (89.2%). Recombinant evolution analysis shows CH/HLJPRVJ/2023 shows many variants in OBP, AN, UL21, UL17, VP11/12, and VP1/2 fragments, which predict its unique genetically. VP1/2, an effector protein of capsid transport and neuroinvasion, has mutations and deletions in its amino acids, which cause changes in the protein conformation of CH/HLJPRVJ/2023. Besides the typical neurologic and respiratory lesions, infection with highly pathogenic CH/HLJPRVJ/2023 can lead to damage to the colonic villi and colonic barrier in piglets. This study will provide a basis for knowledge about the prevalence, genetic evolution, and vaccine optimization of endemic PRV strains in northeastern China.