1株鹅H5N6亚型流感病毒的分离鉴定与遗传进化分析

Isolation,identification and phylogenetic analysis of a goose H5N6 subtype influenza virus

在散养鹅群中检测到流感病毒,经全基因组测序和遗传进化分析,结果显示该分离株为H5N6亚型流感病毒,其HA基因属于Clade2.3.4.4分支,裂解位点序列符合高致病性禽流感病毒的特性。NP基因与M基因均与人源H5N6亚型同源性最近,提示该分离株可能与人源H5N6亚型流感分离株发生过基因重组,并具有感染人类的潜在风险。对SPF鸡致病性试验结果显示,攻毒组和同居组中的所有鸡均死亡;在肺脏、肝脏、肾脏、脾脏、心脏、脑等组织器官均检测到病毒,表明该分离株对鸡具有高致病性和水平传播能力,这警示应该继续加强对H5N6亚型流感病毒的监视和防控。

Waterfowl,including geese,is the reservoir of all subtypes of influenza A viruses,and highly pathogenic influenza A viruses pose a great threat to the health of a variety of birds and mammals.It is of great significance to make surveillance for evolution of influenza A viruses in waterfowl for public health.In this study,influenza A virus was detected and isolated from a flock of geese.The whole genome sequencing and phylogenetic analysis showed that the isolate was H5 N6 subtype influenza A virus.The HA gene belonged to Clade2.3.4.4 branch,and the sequence of cleavage site was the same as that of highly pathogenic avian influenza A virus.NP gene and M gene were highly homologous to that of human origin.It indicated that this H5 N6 isolate may be a recombinant of avian H5 N6 influenza virus and human H5 N6 influenza virus,and pose the potential risk of infecting human beings.Results of pathogenicity test to SPF chickens showed that all chickens in the challenge group and co-resident group died,and the virus was detected in lung,liver,kidney,spleen,heart,brain,indicating that the isolate had high pathogenicity and horizontal transmission ability to chickens,which warned that we should continue to strengthen the surveillance and prevention of H5 N6 influenza virus.