Summary
Pseudorabies virus (PRV), the cause agent of Aujeszky’s disease, is an
infectious pathogen which greatly affects the heathy development of pig
industry worldwide. The low specific host tropism of PRV allows this
virus to infect a variety of animals, such as pigs, cattle, minks, dogs,
and even possible humans. However, the occurrence of PRV natural
infection in goats has never been documented. Herein we provided robust
evidences demonstrating the first case of a variant PRV infection
leading to the acute goat death in Yunnan Province, China, which might
be resulted from mixed feeding with PRV-infected fattening pigs.
Therefore, this report not only highlights the potential threat of newly
emerging variant PRV strain(s) to goat industry, but also appeals the
development of effective and safe vaccines against PRV variants for
goats/ruminants in future.
Keywords: pseudorabies virus variant, goat, natural infection,
China
Introduction
Pseudorabies virus (PRV), also called as Suid alphaherpesvirus 1 that
belongs to the genus Varicellovirus of the sufamilyAlphaherpesviridae , within the family Herpesviridae , is an
enveloped virus with a length of nearly 143 kb linear double-stranded
DNA genome encoding more than 72 genes (Sun et al., 2016; Szpara et al.,
2011). The unique natural and reservoir host for PRV are pigs (including
wild boars), however the first suspected infection of this pathogen was
recorded in American cattle with clinical signs characterized by intense
itching in 1813 (Laval & Enquist, 2020). Since the initial isolation of
PRV in 1902, the presence of this pathogen was widely documented almost
in all pig raising countries, indicating that PRV has quickly swept
across the world and posed a huge threat to various animal species,
especially to the development of pig industry (Lee & Wilson, 1979).
Pseudorabies (PR) is a highly contagious disease that causes severe
clinical symptoms in the infected pigs, thereby leading high morbidity
and mortality especially to the sucking piglets. The infected piglets
usually present clinical signs characterized by diarrhea, vomiting,
nervous system disorders (such as tremor, dyskinesia, and lethargy) (Sun
et al., 2016). Vaccination is regarded as the most effective approach
for the eradication of PR. Though the infectious disease has
successfully been eradicated in some developed countries via the wide
application of virulent gene-deleted live vaccines, PRV remains a fatal
pathogen circulating in Chinese pig population (Freuling, Müller, &
Mettenleiter, 2017; Sun et al., 2018). In this regard, at least two
great PR outbreaks have been witnessed in China, mainly resulting from
PRV classical strains prevalent in the 1990s and variant strains
circulating after 2011, respectively.
PRV has a broad species tropism, which facilitates it to infect a
variety of mammals, including carnivores (Jin, Gao, Liu, Zhang, & Hu,
2016; H. Liu et al., 2017; Serena et al., 2018), ruminants (Cheng et
al., 2020), and rodents. Even a case of human encephalitis caused by a
PRV variant strain has been reported recently (Q. Liu et al., 2020).
However, naturally occurring PRV infection in goats has not been
reported yet. In current study, we provided the first case of a variant
PRV infection causing the acute goat death in Yunnan province, China.
Meanwhile, the genetic characteristics of this PRV strain YNG were
characterized in detail.
Materials and methods