【摘要】 目的了解福州市人感染H7N9流感病毒基因特性及进化分布。方法对2013-2016年福州市流感监测网络实验室从监测哨点医院采集的不明原因肺炎病例中人感染H7N9流感病毒核酸检测阳性的标本进行病毒分离,选取部分H7N9禽流感病毒株进行基因组基因序列测定,使用DNAman.exe分析软件进行基因序列比对,并对病毒关键位点的氨基酸变异情况进行分析,绘制遗传进化树进行进化分布分析。结果血凝素(HA)和神经氨酸酶(NA)基因进化树分析结果显示福州市人感染H7N9禽流感病毒株与以上海、浙江为代表的长三角分支相近。7株毒株中均出现可导致宿主特异性改变、病毒传播力、致病力、毒力及复制能力增强的相关致病位点突变。病毒的HA蛋白受体结合区均发生G186V和Q226L这2个关键氨基酸位点的变异,HA蛋白裂解位点序列均为PEIPKGR↓GLF,含有2个碱性氨基酸。7株病毒的NA蛋白茎杆区69~73位氨基酸均出现缺失。病毒的M2蛋白均发生S31N突变。结论福州市人感染H7N9病毒株具有遗传多样性及复杂性,呈现致病力增强、对金刚烷胺类药物耐药等特点,在监测工作中应加强病原学的监测和遗传变异特性的研究。更多还原

【Abstract】 Objective To understand the genetic variations and evolutionary distribution of Avian influenza A(H7 N9)virus in Fuzhou city of China. Methods The virus strains were isolated from specimens tested positive for the H7 N9 avian influenza virus during 2013 and 2016.Genomes of the avian influenza A(H7 N9)virus were aligned to analyze the nucleotide sequences and deduced amino acid sequences.The phylogenetic tree was constructed using DNAman software. Results Comparing to virus strains from Zhejiang province and Shanghai city,the HA and NA gene evolution of the H7 N9 strains in Fuzhou city are categorized into the Yangtze River Delta evolution branch in the phylogenetic tree.Two alkaline amino acid variances in the cleavage site of HA(G186 Vand Q226 L)were found that are crucial sites related to the receptor of HA protein;in addition,one mutation(E627 K)in the PB2 protein and one drug resistance mutation(S31 N)in the M2 protein were found. Conclusions The genetic characteristics of the prevailed avian influenza A(H7 N9)viruses in Fuzhou city of China are different from the representative strains of Zhejiang province and Shanghai city of China.更多还原