【摘要】 为了解鹅痛风病致病原鹅星状病毒的主要生物学特性，本试验对山东某养殖场临床典型症状雏鹅进行病毒的分离、鉴定、全基因组测序分析及致病性试验。将患病鹅肝、肾等组织病料研磨接种11日龄健康鹅胚，连续传代，收集尿囊液进行鹅星状病毒的RT-PCR鉴定，并利用电镜对病毒粒子的形态进行观察；利用分段扩增法对分离毒株的全基因组进行扩增测序，并与国内外不同宿主源的星状病毒进行同源性分析、绘制系统进化树；分离毒株经口接种1日龄健康雏鹅，通过观察动物的临床表现、检测血清中尿酸含量以及主要脏器的病理变化对分离毒株的致病性进行分析。结果鹅胚连续传代6次后出现规律性死亡，RT-PCR检测及测序确定其为鹅星状病毒，命名为SD株，电镜观察到直径约30 nm的球状病毒粒子，与星状病毒形态一致；全基因测序发现SD株全长7 128 nt(GenBank登录号：OM937013),具有星状病毒典型的基因组结构，同源性分析显示SD株与鹅源星状病毒同源性在61.2%～98.9%之间，其中与HN03株同源性最高为98.9%,与AHAU3株和AHAU5株同源性为98.7%,而与FLX株的同源性只有61.2%,与除鹅源外禽星状病毒同源性在52.9%～67.5%之间，其中与鸭星状病毒的同源性在61.0%～65.6%之间；系统进化树显示SD株与所有的鹅星状病毒都在禽属星状病毒分支上，且与鸭星状病毒和火鸡星状病毒同源关系较近；致病性试验显示SD株能够复制出典型的临床症状，感染组动物发病率100%,死亡率60%,雏鹅血清中尿酸含量显著高于阴性对照组，组织病理学观察发现病死雏鹅肝脏、肾脏和脾脏均有不同程度的损伤和变性，提示SD株应为高致病力毒株。本试验结果可为开发鹅星状病毒的特异性疫苗或精制卵黄抗体等生物制品奠定前期基础。更多还原

【Abstract】 In order to explore the main biological characteristics of goose astrovirus(GAstV),diseased gosling samples with typical symptoms from a farm of Shandong Province were taken and the virus was isolated, identified, sequenced, and tested for pathogenicity.Tissues including livers and kidneys were homogenized and inoculated into 11-day-old healthy goose embryos for successive generations.The allantoic fluid was collected for RT-PCR identification of GAstV,and the morphology of virus particles was observed by electron microscope.The whole genome of the isolated virus was detected by using the segmented amplification method.The homology analysis and phylogenetic tree of the isolated GAstV with the other domestic and foreign GAstVs of different host sources were carried out.The pathogenicity of the isolated virus, orally inoculated to 1-day-old healthy goslings,was analyzed by observing the clinical manifestations,the content of uric acid in serum and the pathological changes of main organs.Results showed that the goose embryos died regularly after 6consecutive passages and the isolate was identified as GAstV(named SD strain)by RT-PCR amplification and sequencing.Globular virus particles with a diameter of about 30nm were observed under electron microscope,which was consistent with the morphology of the GAstV.Results of whole genomic sequencing revealed that SD strain had a total length of 7 128nt(GenBank registration number:OM937013),and a typical genome structure of GAstV.Homological analysis showed that SD strain had 61.2%-98.9% homology with goose origin astrovirus,among which the highest was 98.9% with HN03strain,98.7% with AHAU3and AHAU5strains.However,it was only 61.2% with FLX strain.When compared with other avian original astrovirus,the homology shared 52.9% to 67.5%.Phylogenetic tree showed that SD strain along with all GAstV strains were on the branch of avian astrovirus,and had close genetic relationship with duck astrovirus and turkey astrovirus.The pathogenicity test showed that SD strain could reproduce typical clinical symptoms.The incidence rate and mortality of infected goslings were 100% and 60%,respectively.The serum uric acid content of infected goslings was significantly higher than that of the control group.Histopathological observation showed that the liver,kidney and spleen of dead goslings were damaged and denatured to varying degrees,suggesting that SD strain should be a highly pathogenic strain.All these findings can lay a foundation for the development of specific vaccine or refined egg yolk antibody and other biological products of GAstV.更多还原