广州市2018年输入性登革病毒4型全基因组序列特征分析

目的 本文对广州市2018年输入性DENV-4型病毒的生物学来源进行分析,为本地登革热的防控提供科学依据并累积基线数据。方法 通过传染病监测网络收集广州市2018年输入性DENV-4病例, 对急性期患者血清进行病毒分离培养并对分离到的DENV-4毒株进行全基因组测序、系统发生树重建和生物信息学分析。结果 共分离得到5株DENV-4毒株,其中4株由泰国和柬埔寨输入的分离株均属于DENV-4基因Ⅰ型;菲律宾输入的病例分离株与其他4株亲缘性较低,属于DENV-4基因Ⅱa型;5株分离株间的核苷酸(氨基酸)同源性为90.8%(96.7%~96.9%);经过比对,5株分离株和6株参考株的E蛋白区域有9个位点出现差异,NS1蛋白区域有14个位点出现差异,NS5蛋白区域有25个位点出现差异。结论 本研究对广州地区输入性DENV-4毒株进行全基因组测定,间接地掌握周边国家地区DENV-4的基因特征,为本地登革热的防控和溯源提供基线数据,具有重要的公共卫生意义。

Molecular characteristics of the full-length genomes of DENV-4 strains isolated from imported dengue fever cases in Guangzhou,China,2018

In this article,the biological sources of imported DENV-4 cases in 2018 were analyzed.The information of imported DENV-4 cases was collected in the infectious disease surveillance network;the serum samples in the acute phase of cases were isolated;and the full-length genomes of the DENV-4 strains were sequenced and analyzed by the reconstruction of phylogenetic tree and other bioinformatics analysis.A total of 5 DENV-4 strains were isolated;and 4 strains which imported from Thailand and Cambodia belonged to DENV-4 genotype Ⅰ;the strain imported from Philippines was separated from the other 4 strains in the phylogenetic tree and belonged to DENV-4 genotype Ⅱa.The nucleotide(amino acid)homology among the 5 strains was 90.8%(96.7%~96.9%).Nine substitutions in Envelop protein,14 substitutions in NS1 protein and 25 substitutions in NS5 protein were observed among the 5 isolates and 6 reference sequences by bioinformatics analysis.By full-length genome sequencing,the genetic characteristics of DENV-4 in the surrounding countries and regions are indirectly explored,providing baseline data and information for the prevention and control of local dengue fever in Guangzhou.