【摘要】 目的 分析2018-2019年福建省禽类外环境H5亚型禽流感病毒的分子特征和遗传进化特点，为禽流感防控提供参考依据。方法 对2018-2019年福建省禽类外环境H5亚型单阳性标本进行复核，筛选出Ct值小于30的标本，对HA和NA基因进行靶向扩增和二代测序，从NCBI和GISAID数据库下载参考序列，使用生物信息学软件分别对HA和NA基因进行分子突变位点和遗传进化分析。结果 共完成12株H5亚型HA和NA全基因测序。序列比对结果显示，HA基因最高一致性在98.59%～99.89%,NA基因最高一致性在98.19%～99.85%。遗传进化分析显示，HA基因归属于Clade 2.3.4.4h分支，NA基因归属于欧亚谱系H5N6和H6N6分支。12株毒株的裂解位点均为高致病性禽流感病毒分子特征，受体结合位点为禽源受体，但S123P、S133A、I151T、T156A突变可增强病毒与人源受体的亲和力。HA基因糖基化位点分析显示，常见154位糖基化位点缺失，在124位(-NHTS)新增潜在糖基化位点。结论 2018-2019年福建省禽类外环境中存在Clade 2.3.4.4h进化分支H5N6高致病性禽流感病毒，并且N6基因在进化上具有多样性，提示基因进化重组的可能，需加强对病毒分子进化的持续监测。更多还原

【Abstract】 To analysis the molecular characteristics and genetic evolution of environmental samples of H5 subtype avian influenza virus in Fujian Province from 2018 to 2019. The positive samples of H5 subtype in Fujian Province from 2018 to 2019 were reexamined by fluorescence quantitative RT-PCR, and specimens with Ct value less than 30 were screened for targeted amplication and next-generation sequencing of HA and NA genes. Reference sequences were downloaded from the NCBI and GISAID databases, and the characteristics of molecular variation and genetic evolution were analyzed by using bioinformatics software. A total of 12 strains of H5 subtype HA and NA genes were fully sequenced. The results of database sequence alignment showed that the highest identity of HA gene ranged from 98.59% to 99.89%, and the highest identity of NA gene ranged from 98.19% to 99.85%. All the strains belonged to Clade 2.3.4.4h, and the NA gene belonged to H5N6 and H6N6 of Eurasian lineage. The cleavage sites of all the strains showed the characteristic of highly pathogenicity. Receptor binding sites were avian-derived receptors, however, the mutations of S123P, S133A, I151T and T156A could enhance the affinity of human receptors. Analysis of the HA gene glycosylation sites showed a deletion of glycosylation sites at position 154 and a new potential glycosylation site at position 124(-NHTS). In conclusion, there were H5N6 highly pathogenic avian influenza virus which belonged to Clade 2.3.4.4h evolutionary branch in poultry environments in Fujian Province from 2018 to 2019. And the N6 gene was evolutionarily diverse, suggesting the possibility of genetic evolutionary recombination. Thus, continuous surveillance of the molecular evolution of the virus needs to be strengthened.更多还原