福建省人感染H5N1禽流感病毒血凝素基因测定和分析

Sequencing and analysis of HA gene of Avian influenza H5N1 subtype virus from two human infections found in Fujian province

目的了解我省人感染高致病性禽流感H5N1亚型病毒血凝素基因的特点以及和其他毒株序列间的关系。方法从采集自两例福建省感染者的标本中扩增H5N1禽流感病毒血凝素基因并作序列测定,获得的序列同其他H5N1禽流感病毒的血凝素基因进行比较并作进化分析。结果获得福建省的两例感染者中的H5N1禽流感病毒血凝素基因,并推导出该基因的氨基酸序列。结果表明,两株病毒的血凝素基因在蛋白酶水解位点均含有多个连续的碱性氨基酸,符合高致病性禽流感病毒的特征。经Blast程序检索发现,我省两例感染者与国内其他省份的感染者携带的病毒血凝素基因具有很高的相似性,提示国内的H5N1禽流感病毒感染者的病毒来源可能有一定的关系。结论通过对两例福建省感染者标本中的H5N1禽流感病毒血凝素基因进行序列测定,了解病毒基因的部分特点。通过序列比较分析为分子流行病学调查提供线索,但还需对其他基因序列以及病毒的致病性等生物学特征作进一步分析。

To characterize the hemagglutinin （HA） gene of high pathogenic avian influenza viruses （HPAIV） HSN1 in Fujan province and to analyse the phylogenetic relation with other HSN1 viruses isolated previously. Viral HA gene segments were amplified from the respiratory specimen collected form two human cases, and the product were cloned into plasmid followed by sequencing and comparison with other viral sequence data released previously. A multiple basic residual motif was found in hydrolysis site in two obtained viral HA sequences, which was consistent with the feature of high pathogenicity. By blasting throughout the GenBank and the phylogenetic analysis, the closest related virus sequences were those from the infected persons in Guanxi and Anhui provinces. This result implicates that those viruses, caused human infected, might be close related genetically, but the circulated status were still unclear. Meanwhile,according to the reconstructed phylogenetic tree, there were three groups （Gps） in the viruses participated in the comparison, which was inconsistent with the previous study. The global migratory route of the wild birds and the pattern of poultry raised might contribute to the genetic complexity of avian influenza virus in China mainland. Of the two HPAIV strains found in Fujian, the other internal genes and viral biological feature, including pathogenic effect in animal host, need further identification.