16株新型H3N3亚型禽流感病毒的遗传变异分析  

Genetic Variation Analysis of Sixteen Novel H3N3 Subtype Avian Influenza Viruses

作　　者：赵康宁 杨忠龙 陈怡 朱春成 郭云飞 印云聪 秦涛[1,2] 陈素娟 彭大新[1,2] ZHAO Kangning;YANG Zhonglong;CHEN Yi;ZHU Chuncheng;GUO Yunfei;YIN Yuncong;QIN Tao;CHEN Sujuan;PENG Daxin(College of Veterinary Medicine,Yangzhou University,Yangzhou 225009,China;Jiangsu Co-innovation Center for Prevention and Control of Important Animal,Infectious Diseases and Zoonoses,Yangzhou 225009,China)

机构地区：[1]扬州大学兽医学院,扬州225009 [2]江苏省动物重要疫病与人兽共患病防控协同创新中心,扬州225009

出　　处：《畜牧兽医学报》2024年第9期4029-4040,共12页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：国家重点研发计划项目(2022YFD1801001);江苏省农业科技自主创新资金项目[CX(22)3004];长三角地区家禽-野禽禽流感检测项目(16230027)。

摘　　要：为了解新出现的H3N3亚型禽流感病毒(AIV)的遗传变异特征,对2022—2023年分离鉴定的H3亚型AIV进行了全基因组测序分析,并对代表株进行了抗原差异分析。结果共分离鉴定出15株家禽源和1株野鸟源H3N3亚型AIV。全基因遗传演化分析结果显示,16株分离株均属于欧亚分支,其HA基因均源自H3N8亚型AIV,与人源H3N8亚型AIV的核苷酸相似性为97.3%~99.2%;NA基因均源自H10N3亚型AIV,与人源H10N3亚型毒株的核苷酸相似性为98.1%~98.4%;内部基因片段均来自H9N2亚型AIV。分离株HA基因裂解位点均符合低致病性AIV的分子特征。分离毒株存在多个能增强病毒对哺乳动物适应性及致病性的突变位点,如PB2蛋白的A588V和E627V突变、PB1蛋白的I368V和S375N突变等。抗原差异性分析结果表明,分离株与华东地区早期流行株的HI抗体滴度相差1 log2~3 log2。因此,本研究分离的16株H3N3亚型AIV均为三源重组病毒,由H9N2亚型AIV提供全部内部基因,毒株存在多个哺乳动物适应性及致病性增强的突变,并已传播给野禽。本研究揭示了新型H3N3亚型AIV的遗传特征、变异和多宿主分布情况,为禽流感的防控提供理论支持。In order to understand the genetic variation characteristics of the newly emerged H3N3 subtype avian influenza virus(AIV),we conducted whole-genome sequence analysis of H3 subtype AIV isolated during 2022-2023,and analyzed antigenic differences among representative strains.A total of 15 strains of H3N3 subtype AIV from poultry origin and 1 strain from wildfowl origin were isolated and identified.Phylogenetic analysis of the whole genome revealed that all 16 isolates belonged to the Eurasian lineage,with the HA gene derived from H3N8 subtype AIV,sharing a nucleotide homology of 97.3%to 99.2%when compared to human H3N8 subtype AIV isolates.The NA gene was derived from H10N3 subtype AIV,with a nucleotide homology of 98.1%to 98.4%when compared to human H10N3 subtype AIV isolates.The internal gene segments were all derived from H9N2 subtype AIVs.The cleavage sites of the HA gene of the isolates are consistent with the molecular characteristics of low pathogenic AIV.The isolated strains have multiple mutation sites that can enhance the adaptability and pathogenicity of the virus in mammals,such as the A588V and E627V mutations in the PB2 protein,the I368V and S375N mutations in the PB1 protein.Antigenic difference analysis showed that the isolates had HI antibody titers 1 log2-3 log2 different from those of earlier circulating strains in East China.Therefore,all 16 strains of H3N3 AIVs in this study are triple-recombinant viruses,with H9N2 AIV serving as the donor for all internal genes,and they harbor multiple amino acid mutations that enhance their adaptability and pathogenicity in mammals.These strains have already spread to wildfowl.This study reveals the genetic characteristics,variation and multi host distribution of the novel H3N3 AIVs,providing theoretical support for the prevention and control of avian influenza.

关 键 词：禽流感病毒 新型 H3N3亚型 基因变异 抗原变异 

分 类 号：S852.659.5[农业科学—基础兽医学]