Characterization and genomic analysis of emerging astroviruses causing fatal gout in goslings

Abstract

Since February 2017, severe outbreaks of fatal gout caused by novel gosling astroviruses (GoAstVs) have occurred in several Chinese provinces, causing a considerable economic impact on the poultry industry. To assess the infection status of GoAstVs causing gout, 165 clinical samples were collected from goslings from seven farms located in different Chinese provinces, and they were screened for viral infection. Seven GoAstV strains were completely sequenced. The positive infection rates of GoAstV, goose parvovirus, reovirus, goose haemorrhagic polyomavirus and Tembusu virus were 100%, 9.69%, 3.64%, 0% and 0%, respectively, indicating the role of GoAstV in gout. The genomes of all seven GoAstV strains were 7170‐nt long and encoded three open reading frames (ORFs), namely, ORF1a, ORF1b and ORF2. Sequence and phylogenetic analyses of the seven GoAstV strains showed that these were avastroviruses and were closely related to viruses classified within Avastrovirus 3 and turkey astrovirus 2. Moreover, the mutation rates of ORF1a and ORF2 were high, and ORF1a was highly mutated at amino acid loci 545–580. The tertiary structure of the mutated ORF2 protein was smooth, and its antigenic epitope was highly mutated, which may be related to the pathogenicity of the virus and caused by antibody pressure from the host. These findings enrich our understanding of the evolution of novel GoAstVs causing gout and their circulation as well as lay the foundation for the selection of vaccine strains.

Coinfection of parvovirus and astrovirus in gout‐affected goslings

“…While it is believed that the novel GoAstV is causal agent for the emerging gosling gout, several reports indicated that other infectious agents together with GoAstV may collectively contribute to the development of gout in gosling (Bulbule et al, 2013;Chen et al, 2020;Liu et al, 2019). In this study, we identified the coin- In compared with AstV-induced diseases in other hosts, the findings in this study might imply the increasing severity of gout which might be associated with coinfection of GoAstV and GPV.…”

“…While it is believed that the novel GoAstV is causal agent for the emerging gosling gout, several reports indicated that other infectious agents together with GoAstV may collectively contribute to the development of gout in gosling (Bulbule et al, 2013; Chen et al., 2020; Liu et al., 2019). In this study, we identified the coinfection of GoAstV and GPV in gout‐affected goslings in 12 goose farms.…”

Novel goose-origin astrovirus infection in geese: the effect of age at infection

“…Chicken astroviruses have been reported to induce gout disease in chickens ( Bulbule et al., 2013 ), and the susceptibility of turkeys to TAstVs at different ages has been reported ( Awe et al., 2015 ). At present, a few studies have reported the genomic characteristics of novel goose astrovirus causing fatal gout in goslings ( Liu et al., 2018 ; Chen et al., 2020 ), with some reports about the pathogenicity of astrovirus ( Zhang et al., 2018 ). To the best of our knowledge, there are few reports that age at infection affected the outcome of AStV infection in goslings.…”

Novel genotype definition and genome characteristics of duck circovirus in central and Eastern China

“…Subsequently, liver and spleen DNA and RNA samples were subjected to polymerase chain reaction (PCR) amplification. Infection status and co‐infections were assessed by testing for the presence of DuCV, duck‐origin goose parvovirus (DGPV), reovirus (REOV) and Tembusu virus (TMUV) using previously described PCR and RT‐PCR protocols (Chen et al., 2020; Woźniakowski, Samorek‐Salamonowicz, & Gaweł, 2014). Furthermore, a duplex PCR assay was also used for simultaneous detection and differentiation of DuCV1 and DuCV2 as described previously (Li, Zhang, Xia, & Xie, 2014).…”