中国部分地区发热伴血小板减少综合征病毒M片段分子流行病学研究

Molecular epidemiological study on M fragment of fever with thrombocytopenia syndrome virus in parts of China

目的研究中国地区发热伴血小板减少综合征病毒(severe fever with thrombocytopenia syndrome virus, SFTSV)分离株已上传至GenBank序列中M片段基本特征及该病毒的遗传和进化规律。方法从GenBank中获取2020年6月25日前分离于中国的SFTSV毒株M片段全序,利用BioEdit软件进行多序列比对,MEGA5.0软件构建系统发生树,比较不同型别及不同来源SFTSV核苷酸和氨基酸的同源性。结果在GenBank数据库收集到203株中国地区发热伴血小板减少综合征病毒分离株的M片段全序,其中分离于人的毒株185株,占总毒株的91.1%,分离于蜱的毒株共11株,占总毒株的5.4%,分离于其他动物如羊、鼠、刺猬的共5株,占总毒株的3.5%。系统发生树分析显示中国地区流行优势株为C2基因亚型,占总毒株的42.4%,核苷酸序列和氨基酸序列同源性分别为96.4%~100.0%和94 .5%~100.0%。人源毒株与动物分离株同源性极高,核苷酸序列和氨基酸序列同源性分别为92.5%~100.0%和92.0%~100.0%。结论对分离自中国的发热伴血小板减少综合征病毒分离株优势株为C2型,且存在着多种型别的共循环。SFTSV可能有从C型向J型进行适应性转换的可能。

Objective To study the basic characteristics and gene evolution of M segment of fever and thrombocytopenia syndrome virus(SFTSV)in China.Methods The full sequence of M fragment of SFTSV strain isolated in China before June 25,2020 was obtained from GenBank.The BioEdit software was used for multi-sequence alignment and MEGA5.0 software was used to construct the phylogenetic tree to compare the homology of SFTSV,which came from different types and sources.Results M fragments of 203 SFTSV isolated in China was collected from GenBank database..Among them,185 strains were isolated from humans(91.1%),11 strains were isolated from ticks(5.4%),and 5 strains were isolated from goat,mice and hedgehog(3.5%).Phylogenetic tree analysis showed that C2 genotype was dominant in China,accounting for 42.4%of total.The nucleotide sequence and amino acid sequence homology were 96.4%~100.0%,94.5%~100.0%,respectively.The homology of human and animal isolates was very high.The nucleotide sequence and amino acid sequence homology were 92.5%~100.0%and 92.0%~100.0%,respectively.Conclusions Phylogenetic tree analysis of SFTSV isolates in China based on the M fragment showed that C2 genotype was dominant,and there are multiple types of co-circulation.By comparing M and S-segment-based phylogenetic tree,it suggests that SFTSV may potential undergo adaptive conversion from C-type to J-type.