Isolation and phylogenetic analysis of goose astrovirus type 1 from goslings with gout in Jiangxi province, China

Abstract

Goose astrovirus (GoAstV) is a new Avastrovirus of the genus astrovirus causing gout, hemorrhage, and swellings of kidneys that have affected goslings around the major goose-producing regions in China. The GoAstV is divided into goose astrovirus type 1 (GoAstV-1) and goose astrovirus type 2 (GoAstV-2). Although GoAstV-2 is known to be the causative agent of goose gout, little published information about the relationship between GoAstV-1 and goose gout is unknown. In this study, we investigated the presence of GoAstV-1 in 293 visceral tissue/dead embryos samples with gout on different farms in Jiangxi province, China. A survey result indicated that the mono-infection of GoAstV-1 (32.08%) and co-infection of GoAstV-1 (12.28%) with GoAstV-2 in gout goslings in Jiangxi, China. JXGZ, a GoAstV-1 strain, was effectively isolated from the visceral tissue of gosling gout and serially propagated for more than 25 passages in a goose embryo. The JXGZ strain's whole genome was sequenced and investigated. Phylogenetic analysis of complete genome and capsid protein sequences of JXGZ strain show that it was more closely related to GoAstV-1 strain than GoAstV-2 strain and was grouped within the GoAstV-1 cluster. These findings will aid in the development of efficient diagnostic reagents and possible vaccinations by providing insight into the prevalence and genetic evolution of GoAstV-1 in China.

Keywords: goose astrovirus type 1; goose gout; isolation; phylogenetic analysis.

Figure 1

Phylogenetic tree of the nucleotide sequences of AstVs isolates based on the complete genome (A), ORF1a (B), ORF1b (C), and ORF2 (D). All the reference sequences used in this study were obtained from the GenBank database. The Tree was constructed by the neighbor-joining method with 1,000 bootstrap replications using MEGA 7.0.14 software. The JXGZ strains (GenBank accession no. OL762471) were marked with a black triangle.

Figure 2

Gross lesions and pathologic changes of goslings infected with GoAstV-1 strain JXGZ. Macroscopic lesions of visceral organs (A, a), kidneys(B, b), articular cavity(C, c) from the infected gosling (A, B, C), and uninfected (a, b, c) at 5 dpi. The tissues from the goslings incubated with JXGZ or PBS were collected at 5 DPI and were stained with hematoxylin and eosin. Severe cell necrosis with inflammatory cell infiltration in the GoAstV-1 infected goslings' spleen, liver, and kidney, is presented.