Abstract: In order to investigate the current prevalence and variation of pseudorabies virus (PRV) in Guangdong Province, blood samples of diseased pigs with suspected PRV infection were collected from a large-scale pig farm in Foshan City, Guangdong Province in 2020. PRV was identified by transmission electron microscopy and indirect immunofluorescence, and which was named as GDFS2020 strain. Molecular characteristics and genetic evolution of gB, gC, gD, gE and TK deduced amino acid sequences were analyzed. The results indicated that GDFS2020 strain was a domestic variant, but there were individual amino acid mutations. The results of the pathogenicity test showed that there were infarcts at the edge of liver, hyperemia, swelling, and congestion in heart, kidney, spleen, and brain tissues. The results of the histopathological section showed obvious pathological changes such as degeneration and atrophy of neurons, nucleus slightly shrunken, and increase of voids in brain. Our results indicated that a mutant PRV strain was successfully isolated in this study and had high pathogenicity in rabbits, providing reference data for the epidemiological research and genetic evolution of PRV in Guangdong Province.

Key words: porcine pseudorabies virus, isolation and identification, sequence analysis, rabbits, pathogenicity