野鸟源H8N2亚型禽流感病毒的生物学特性分析  

Biological characteristics of an H8N2 avian influenza virus isolated from wild bird

作　　者：田井满 李明慧 白晓利 李玉磊 刘丽娜[1] 李雁冰[1] 陈化兰[1] TIAN Jing-man;LI Ming-hui;BAI Xiao-li;LI Yu-lei;LIU Li-na;LI Yan-bing;CHEN Hua-lan(Animal Influenza Key Laboratory of the Ministry of Agriculture and Rural Affairs,State Key Laboratory of veterinary Biotechnology,Harbin Veterinary Research Institute,Chinese Academy of Agricultural Sciences,Harbin 150069,China)

机构地区：[1]中国农业科学院哈尔滨兽医研究所兽医生物技术国家重点实验室/农业部动物流感重点开放实验室,黑龙江哈尔滨150069

出　　处：《中国预防兽医学报》2022年第6期577-582,共6页Chinese Journal of Preventive Veterinary Medicine

基　　金：国家重点研发计划(2019YFC1200400);国家自然科学基金创新群体项目(31521005);黑龙江省科学基金重点项目(2018ZD007)。

摘　　要：本研究团队于2019年在常规主动监测野鸟源禽流感病毒(AIV)时,于山东省荣成市分离到一株H8N2亚型AIV,为了解该株H8N2亚型AIV的生物学特性,本研究对其全基因组进行了测序及遗传演化分析。结果显示,该病毒HA和NA基因分别来自鸭源H8N4和H9N2亚型AIV,其部分内部基因来源于野鸟源AIV,而且该H8N2亚型AIV的PB2基因起源于北美,表明该H8N2亚型AIV是一株跨大陆、跨物种、多亚型的重组AIV。关键氨基酸位点分析显示,其HA蛋白碱性裂解位点氨基酸序列为SIEPK/GLF,为低致病AIV分子标志;PB1蛋白出现D622G突变,NS1蛋白存在P^(42)S、I^(106)M、C^(138)F突变,提示其具有增强对哺乳动物致病性的潜在能力。采用该H8N2亚型AIV感染SPF鸡后采集各脏器及拭子样品,接种鸡胚后通过病毒滴定试验检测,结果显示,该病毒不能通过SPF鸡的喉头或泄殖腔排毒,且在感染鸡各脏器中均未检测到该病毒的有效复制。进一步采用该病毒感染BALB/c小鼠后观察临床症状,并采集各脏器后利用普通鸡胚进行脏器病毒滴定试验,结果显示,小鼠感染病毒后无明显临床症状和体质量下降。该H8N2亚型AIV虽不致死小鼠,但在其肺脏、鼻甲、肾脏以及脾脏均可有效复制。本研究对该H8N2亚型AIV的部分生物学特性进行了探究,为H8N2亚型AI的综合防控提供参考依据。During regular active surveillance of avian influenza virus from wild birds in China in 2019,one H8N2 subtype avian influenza virus was isolated in Rongcheng city,Shandong province.Phylogenetic analysis indicated that the HA and NA genes of H8N2 isolate originated from the H8N4 and H9N2 viruses of domestic ducks respectively,part of the internal genes derived from wild birds,and the PB2 gene came from North America lineage.These results showed that the H8N2 is a crosscontinental,cross-species,multi-subtype recombinant AIV.The HA protein of the H8N2 virus carried the cleavage-site motif SIEPK/GLF,which indicated low pathogenicity of the virus in chickens.However,the D622G mutation in PB1 protein and the P^(42)S,I^(106)M,and C^(138)F residues changed in NS1 protein,implying the virus could exhibit increased virulence in mice.Viral pathogenicity in SPF chickens indicated that the H8N2 virus could not effectively replicate in the organs of chickens and virus shedding could not be detected in oropharyngeal and cloacal samples after intravenous inoculation.Viral pathogenicity in mice indicated that the H8N2 virus is able to replicate in the lungs,nasal turbinates,spleens and kidneys of mice without prior adaptation,and the virus causes slight weight loss and inapparent signs of disease in mice.The biological characteristics of the virus were explored in this study,providing a theoretical basis for the comprehensive prevention and control of H8N2 subtype AI.

关 键 词：禽流感病毒 H8N2 野鸟 跨大陆重组 跨种感染 

分 类 号：S852.65[农业科学—基础兽医学]