2020-2022年山东地区H9N2亚型禽流感病毒的遗传进化分析  

Evolutionary analysis of H9N2 subtype avian influenza virus in Shandong in 2020-2022

作　　者：薛瑞雪 孙海峰[2] 邢林林 姜子昕 李玉杰[1] 陈峰 蔺晓月 兰邹然[1] 张月[1] 王贵升[1] XUE Ruixue;SUN Haifeng;XING Linlin;JIANG Zixin;LI Yujie;CHEN Feng;LIN Xiaoyue;LAN Zouran;ZHANG Yue;WANG Guisheng(Provincial Center for Animal Disease Control(Shandong Provincial Center for Zoonoses Epidemiology Investigation and Surveillance),Jinan 250100,China;Haidu College,Qingdao Agricultural University,Yantai,Shandong 265200,China)

机构地区：[1]山东省动物疫病预防与控制中心(山东省人畜共患病流调监测中心),山东济南250100 [2]青岛农业大学海都学院,山东烟台265200

出　　处：《中国兽医学报》2024年第8期1611-1621,共11页Chinese Journal of Veterinary Science

基　　金：山东省重点研发计划(重大科技创新工程)基金资助项目(2022CXGC010606)。

摘　　要：为了解山东省H9N2亚型禽流感病毒(avian influenza virus,AIV)流行及遗传变异情况,采用H9亚型AIV荧光定量RT-PCR方法对采集自山东部分地区有呼吸道症状养鸡场的492份鸡气管和肺脏组织样品进行检测,并对检测出的阳性样品进行鸡胚接种,利用Illumina Miseq测序平台将分离株进行全基因组测序,并构建了进化树,分析了与流感病毒传播能力及致病性相关的关键氨基酸位点的特征。结果显示,492份样品中有72份为H9亚型AIV阳性,阳性率14.63%,阳性样品经鸡胚传代后获得34株H9亚型AIV,通过全基因组测序后分析可得34株分离株均为H9N2亚型AIV。通过HA和NA基因进化树分析,34株分离株HA基因均属于Y280-like分支,NA基因均属于F/98-like分支,在此分支基础上,均存在明显的时间节点小分支,一支为“2013年以前分离株”分支,一支为“2013年以后分离株”分支。分离株HA裂解位点均为^(325)PSRSSR↓GLF^(333),符合低致病性AIV特征,所有病毒均发生了Q226L具有结合哺乳动物α-2,6受体的能力的氨基酸位点突变。内部基因哺乳动物适应性关键氨基酸位点中,所有病毒PB1蛋白发生了I^(368)V增强病毒在哺乳动物传播能力的氨基酸位点突变,部分毒株PB2蛋白发生I292V和A588V哺乳动物适应性增强的氨基酸位点突变。结果表明,山东省H9N2亚型AIV各基因节段存在不同程度的重组和基因变异情况,需加强病毒变异监测。In order to understand the prevalence and genetic variation of H9N2 subtype avian influenza virus in Shandong,a total 492 tracheal and lung tissue samples collected from chicken farms with respiratory symptoms in partial areas in Shandong were detected by H9 subtype AIV real-time RT-PCR,and the positive samples were inoculated with chicken embryos for two generations.Whole genome sequences of the positive strains by applying Illumina Miaseq platform,and genetic evolution and mutation at positions associating with viral pathogenicity and transmissibility were analyzed.The results showed that there were 72 samples were positive for H9 subtype AIV among the 492 samples,with a positive rate of 14.63%.Thirty-four strains of H9 subtype AIV were obtained from the positive samples after passing through chicken embryo,meanwhile,the 34 isolates were all H9N2 subtype AIV by whole genome sequencing analysis.By analyzing the evolutionary tree of HA and NA genes,HA and NA genes of the 34 H9N2AIV strains belonged to Y280-like branch and F/98-like branch,respectively.Meanwhile,based on above branches,there were obvious time node subbranch,which one was“isolates before 2013”,another one was“isolates after 2013”.The HA cleavage sites of thirty-four H9N2strains were all^(325)PSRSSR↓GLF^(333),which met the sequence characteristics of the lowly pathogenic avian influenza virus,and the HA receptor binding site 226amino acid was leucine,which had the characteristics of blinding toα-2,6mammalian sialic acid receptors.Among the internal amino acid sites that are key to mammalian adaptation,all strains had an I^(368)V mutation in the PB1gene that enhanced viral transmissibility in mammals and the PB2genes of some strains were mutated to enhance the mammalian adaptation of I292 V and A588 V.The above results illustrated that the H9N2subtype AIV gene segments in Shandong have different degrees of recombination and gene variation,so it is necessary to strengthen the monitoring of virus variation.

关 键 词：禽流感病毒 H9N2亚型 遗传进化分析 

分 类 号：S852.4[农业科学—基础兽医学]