2.4 Pseudorabies Virus

Pseudorabies virus (Suid herpesvirus 1 or PRV) is a member of the genusVaricellovirus , and the family Herpesviridae (Peng et al., 2016). PRV is the major causative agent of Aujeszky’s disease and contributes to the substantial economic losses in swine production (Freuling, Muller, & Mettenleiter, 2017).
PRV always targets the mucosal epithelium of the pig respiratory and nervous system tissue, causing central nervous system infection and respiratory disease (Pomeranz, Reynolds, & Hengartner, 2005). PRV infection can downregulate the function of macrophage, under conditions such as phagocytosis, killing of phagocytized bacteria, IFN-α production and phagosome fusion were downregulated in PRV infected pigs (Fuentes & Pijoan, 1986; Iglesias, Pijoan, & Molitor, 1992). Shibata and colleagues have indicated that the mean percentage of the lung lesions were 0.1% and 8.3% inoculate with Mhp alone, whereas 9.8% and 17.2% in co-infection with Mhp and PRV in post-inoculation-week (PIW) 2 and 4 respectively(Shibata et al., 1998). Consequently, PRV infection appears to have effect on the severity of experimentally induced acute Mhp in young pigs. Further studies will prove the exact mechanism involved in the interaction of PRV with Mhp, providing reference for the developing of vaccine which can combat both pathogens.