长沙市首例人感染H9N2禽流感病毒的HA基因序列特征分析

目的对长沙市首例人源H9N2禽流感病毒进行病毒分离与HA基因特征序列分析。方法用细胞培养法在可疑病例标本中分离H9N2禽流感病毒毒株,RT-PCR方法扩增禽流感病毒HA基因全长并测序,对所得结果进行氨基酸同源性与进化树分析。结果分离的毒株命名为A/Hunan/44558/2015,GenBank登录号为KX595338。毒株存在2处新发突变位点,HAT197D、HAD483N,第313位出现与湖南省人源H9N2毒株A/Lengshuitan/11197/2013相同的糖基化位点NCS。与A/Wild Chicken/Shanghai/C1/2014和A/Environment/Hunan/28028/2014的同源性分别为97.9%和97.6%。进化树分析分离的毒株处于Y280分支。结论发现病毒2处新的基因突变位点,与2014年湖南省环境源毒株同源性较高,存在基因交换重组,从分子水平揭示病毒HA基因的进化趋势。

Isolation and characteristic analysis of an avian influenza virus (H9N2) from a patient in Changsha,China

In order to analyze the characteristic of hemagglutinin gene in an avian influenza virus (H9N2) that occurred in human, influenza-like illness sample was collected in a routine supervision and we confirmed the virus as H9N2 avian influenza virus by RT-PCR, and DNA sequencing. Homology and phylogeny tree analysis was performed after amplification of the HA gene fragment. The nucleotide sequence GenBank accession number is NO:KX595338. DNA sequencing showed that two mutation sites included HAT197D and HAD483N were found. The glycosylation site in 313 location of HA gene was the same to A/Lengshuitan/11197/2013 virus. Phylogenetic and homology analysis revealed that it belong to Y280-like branch, and had 97.6% percent identity compared with A/Environment/Hunan/28028/2014. In all, the study results reveal two novel mutation sites, and with highly homology with avian influenza virus isolated from Hunan Province environment. Our results highlight the genetic re-assortment of H9N2 virus was existed.