H9N2亚型禽流感病毒的序列分析及对哺乳动物致病力研究

摘要

为研究H9N2亚型禽流感病毒(AIV)对哺乳动物的致病力,本研究选取了2009年～2010年从我国南方地区分离到的6株H9N2AIV,测定分析了其基因组序列及在小鼠体内的复制能力.HA基因分析显示:6株病毒均属于A/CK/BJ/94谱系,HA均含有人样受体结合位点Leu226.PB2基因分析表明,6株H9N2AIV分离株均具有AIV低致病力的分子特征(Glu627和Asp701).对BALB/c小鼠感染试验显示:感染组无任何临床症状及增重;病毒仅局限于小鼠呼吸道复制.本研究结果有助于全面了解近年我国H9N2AIV分子进化情况,并对评估H9N2AIV对哺乳动物的潜在威胁提供参考.%To study the pathogenesis of H9N2 avian influenza virus (AIV) in mammalian host,we sequenced the genomes of 6 H9N2 AIVs isolated in southern China during 2009 to 2010 and determined their replicative ability in mice.Phylogenetic analysis of the HA genes of these H9N2 viruses revealed that they all belonged to A/CK/BJ/94 lineage and possessed Leu226,which has been shown to possess human type receptor binding specificity.The PB2 gene of these 6 viruses possessed Glu627 and Asp701,which are the molecular signatures of low pathogenic AIV.The pathogenic study showed that these H9N2 viruses were low pathogenic in BALB/c mice,causing no significant change of body weight and restricting their replication in respiratory organs.Our study is helpful for a further investigation of the genetic evolution of H9N2 AIV in China.