2014-2018年新疆人感染H7N9禽流感分子流行病学特征分析

Molecular epidemiological characteristics of human infection with avian influenza A(H7N9)virus in Xinjiang from 2014 to 2018

目的分析2014-2018年新疆14例人感染H7N9禽流感病例的分子流行病学特征,为防控及治疗提供科学依据。方法提取核酸后采用高通量基因测序技术获得基因组序列,并用生物信息学分析软件对基因组序列进行同源性分析、进化分析、变异位点分析及同源建模。结果14例人感染H7N9禽流感病毒HA基因核苷酸同源性介于97.39%~100%,氨基酸同源性介于98.38%~100%;NA基因核苷酸同源性介于97.73%~100%,氨基酸同源性介于97.73%~100%,均属于长江三角洲谱系和低致病性禽流感病毒,分属于2个亚分支,与A/Hunan/02650/2016疫苗株最为接近。HA蛋白G186V、T160A全部发生了变异,Q226L中13株病毒发生了变异,NA蛋白4个关键的神经氨酸酶抑制剂耐药位点全部未发生变异。M2蛋白S31N和V27A位点全部发生了突变,PB1蛋白T368V位点全部发生了突变,PA蛋白位点K356R全部发生了突变。结论新疆H7N9禽流感病毒具有双受体结合性,对金刚烷胺类药物耐药,对神经氨酸酶抑制剂敏感,可在疾病发生早期及时使用神经氨酸酶抑制剂。需加强禽流感病毒基因组变化的监测,做好基因突变的应对措施。

This study was aimed at analyzing the molecular epidemiological characteristics of all 14 cases of human infection with avian influenza A(H7N9)virus in Xinjiang from 2014 to 2018,to provide a scientific basis for prevention,control,and treatment.The genomic sequence was obtained through high-throughput gene sequencing after nucleic acid extraction.Homology analysis,evolution analysis,mutation locus analysis,and homology modeling were performed in bioinformatics analysis software.The nucleotide homology and amino acid homology of the HA gene in 14 human infected H7N9 viruses were(97.39%-100%)and(98.38%-100%),respectively.The nucleotide homology of the NA gene and the amino acid homology ranged from 97.73%to 100%.All viruses were low pathogenic avian influenza viruses belonging to the Yangtze River Delta lineage and were divided into two subclades,which were most similar to the A/Hunan/02650/2016 vaccine strain.All HA proteins G186V and T160A were mutated;13 strains of Q226L were mutated;and none of the four key neuraminidase inhibitor resistance sites of NA protein were mutated.All sites of M2 protein S31N and V27A were mutated,all sites of PB1 protein T368V were mutated,and all sites of PA protein K356R were mutated.Xinjiang H7N9 virus exhibited double receptor binding,and was resistant to amantadine drugs and sensitive to neur aminidase inhibitors,which may be used in early disease stages.Strengthened monitoring and timely detection of avian influenza virus genome changes will be critical for prevention and control,and formulation of countermeasures.