福建省首株基孔肯雅病毒株的分离、鉴定及全基因特征分析

Isolation,Identification and Complete Gene Characterization of the First Chikungunya Virus Strain in Fujian Province,China

为获得基孔肯雅病毒(Chikungunya virus,CHIKV)毒株并了解其分子生物学特征,本研究通过将2018年6月从菲律宾输入的基孔肯雅热(Chikungunya fever,CHIKF)病例发病1d的血清标本接种C6/36细胞进行病毒分离,并成功分离到福建省首株CHIKV毒株FJCHIKV1801。利用高通量测序方法对该毒株进行测序,成功获得完整的基因序列,全长12139 bp。通过E1、E2结构蛋白重要氨基酸位点分析发现所获毒株E1蛋白氨基酸出现了可能增强埃及伊蚊的适应性突变K211E。最大似然法系统进化树分析结果显示毒株FJCHIKV1801的基因型属于亚洲基因型;其进化关系与2014年菲律宾分离的毒株Philippines 2014(MF773563)最为接近,提示毒株可能来源于菲律宾,这与该毒株源病例来源于菲律宾的流行病学调查结果相一致。本研究所建立的CHIKV病毒分离、基因测序和分析的方法可用于追溯可能的传染来源及监测病毒氨基酸变异情况,为CHIKF突发疫情处置提供技术支持。

To obtain the Chikungunya virus(CHIKV)strain and understand its molecular biological characteristics,C6/36 cells was inoculated with the serum sample from Chikungunya fever(CHIKF)case imported from the Philippines in June 2018 on the first day of onset,and the first CHIKV strain(FJCHIKV1801)in Fujian Province was successfully isolated.This strain was sequenced by high-throughput sequencing,and the complete gene sequence was obtained,with a full length of 12,139 bp.Analysis of the important amino acid sites of E1 and E2 structural proteins of the obtained strain showed that the amino acids of the E1 protein had the mutation K211E,which may enhance the fitness of Aedes aegypti.The phylogenetic tree showed that the genotype of strain FJCHIKV1801 belonged to the Asian genotype.Its evolutionary relationship was closest to the strain Philippines 2014(MF773563),suggesting that the strain may be originated from the Philippines.This result was consistent with the epidemiological investigation of the source case of this strain which was from the Philippines.The method of virus isolation,gene sequencing and analyses of the CHIKV established in this study can be used to trace the possible source of infection and monitor the amino acid variation of CHIKV,so as to provide technical support for responding to the CHIKF outbreak.