TK/gI/gE/11K Genes Is Not Involved in the Virulence Enhancement of Highly Virulent Pseudorabies Virus

Abstract

The large-scale outbreaks of Pseudorabies in china since 2011 in vaccine-immunized pig farms were caused by the highly virulent Pseudorabies virus (PRV). To investigate the factors involved in the virulence enhancement of the variant PRV, four recombinant viruses with the virulence gene’s replacement, gI/gE/11K and TK/gI/gE/11K, between the variant strain HN1201 and the classical strain Fa were constructed based on bacterial artificial chromosome infectious clones. Compared with their parental strain, the viral titers of the recombinant PRV strains are not strongly influenced by the replacement of TK/gI/gE/11K, while as previously reported, the strain HN1201 and its derived viruses showed the higher mortality, the severer clinical symptoms and tissues damage than that of strain Fa and its derived strains. In summary, the TK/gI/gE/11K genes of variant strain HN1201 showed no contribute to its virulence enhancement compares with the classical strain.