鹅星状病毒江苏分离株JSSQ遗传特征分析

Genetic characterization of goose astrovirus strain JSSQ isolated from Jiangsu province

摘要:

【背景】自2016年以来，我国山东、安徽、江苏、广东等养鹅地区暴发了一种以痛风为主要特征的急性传染病。【目的】研究引起江苏某鹅场雏鹅痛风的鹅星状病毒(goose astrovirus，GAstV)的基因组特征。【方法】从疑似患有痛风的雏鹅肝脏样品中分离到一株GAstV，命名为JSSQ，并对JSSQ全基因组序列及遗传特征进行分析。【结果】 GAstV JSSQ株可在LMH细胞上稳定传代，无明显细胞病变；该毒株基因组全长7 175 nt，与其他已报道的鹅星状病毒参考株相似性为57.3%-99.1%。系统进化分析显示，JSSQ与参考毒株AHAU3亲缘关系最近，处于同一分支。重组分析显示，在GAstV JSSQ基因组中的第807和2 818位点发生了2次重组，起源于GDAHAU2(major parent)和AHAU4(minor parent)。抗原表位分析显示，在ORF2区出现多处氨基酸突变，存在P64S、A224T、A228S、Q229P等独特突变，可引起抗原表位的变化。【结论】不同地区GAstV可能存在不同生物学特性，在防控中应予以注意。

Abstract:

[Background] A severe infectious disease characterized with gout has attacked the goslings in Shandong, Anhui, Jiangsu, and Guangdong provinces in China since 2016. [Objective] To study the genetic characteristics of goose astrovirus (GAstV) causing this disease. [Methods] A strain of GAstV, named JSSQ, was isolated from the liver sample of a gosling suspected to be undergoing gout from a goose farm in Jiangsu province. The virus genes were sequenced for the genetic characterization. [Results] GAstV JSSQ strain stably propagated in LMH cells without obvious cytopathic changes. The strain had a full-length genome of 7 175 nt and shared the similarity of 57.3%–99.1% with other reported reference strains of GAstV. The phylogenetic analysis showed that JSSQ was close related to the reference strain AHAU3 and they were in the same branch. Two recombination events occurred at the sites 807 and 2 818 in GAstV JSSQ genome, originating from GD AHAU2 (major parent) and AHAU4 (minor parent). The antigenic epitope analysis showed that there were several amino acid mutations, such as P64S, A224T, A228S, and Q229P, in ORF2 region, which resulted in changes in antigenic epitope. [Conclusion] The biological characteristics may vary between the GAstVs in different areas, and thus attention should be paid to the prevention and control of such viruses.