鸭甲型肝炎病毒的遗传和抗原稳定性分析

GENETIC AND ANTIGENIC VARIATIONS OF DUCK HEPATITIS A VIRUSES

本研究测定了实验室保存的25株(2000年～2017年)鸭甲型肝炎病毒1型(DHAV-1)和32株(2008年～2017年)鸭甲型肝炎病毒3型(DHAV-3)的VP1基因序列,利用生物信息学软件对其以及Genbank中下载的DHAV的VP1基因进行遗传进化关系分析,并选取代表毒株进行血清中和试验,分析DHAV-1或DHAV-3的遗传和抗原稳定性。结果表明,DHAV-1进化为2个遗传分支,2016年～2017年的分离毒株分布在同一分支上;DHAV-3进化为2个不同的分支,2008年～2017年分离毒株集中在相同分支上,又进一步进化为不同的亚分支;DHAV-1或DHAV-3毒株之间无明显的地理分布差异。血清交叉中和试验结果表明,DHAV-1或DHAV-3同一血清型之间具有较好的交叉保护,表明同一血清型的DHAV未发生抗原变异。本研究揭示了DHAV-1或DHAV-3的遗传进化特点和相同血清型之间的抗原稳定性。

In the present study,25 DHAV-1 isolates collected during 2000-2017 and 32 DHAV-3 isolates collected in 2008-2017 were used for genetic and antigenic analysis based on their VP1 coding sequences.All of these isolates were obtained from clinical cases.Antigenic variations of representative DHAV-1 and DHAV-3 strains were evaluated using serum neutralization assay.Bioinformatics analysis of VP1 sequences of these isolates and other published DHAV strains demonstrated that DHAV-1 viruses evolved into two genetic lineages,among which those strains isolated in 2016-2017 were distributed into the same lineage.On the contrary,DHAV-3 viruses exhibited two distinct lineages and those strains isolated in 2008-2017 were classified into the same lineage.No differences in geographical distributions were observed among DHAV-1 or DHAV-3 viruses.Antigenic analysis of representative DHAV-1 and DHAV-3 strains revealed no detectable changes in viral neutralization properties within the same serotype.Results of these experiments described here would give novel insights into genetic and antigenic variability of duck hepatitis A viruses.