摘要
目的对引起天津滨海新区本土新型冠状病毒肺炎(COVID-19,简称新冠肺炎)疫情的新型冠状病毒(SARS-CoV-2,简称新冠病毒)进行全基因组溯源及变异情况分析。方法对2020年11月7日至12月5日采集的天津滨海新区新冠肺炎疫情1例本地无症状感染者和5例确诊病例咽拭子样本进行全基因组高通量测序,De novo拼接测序数据,使用MAFFT v7.0多重序列比对程序和MEGA X软件对上述数据进行比对和构建系统进化树(Neighbor-joining法)。结果6株新冠病毒序列与武汉参考序列(Wuhan-Hu-1)基因相似度均大于99.9%;6株病毒中2株基因完全相同,符合L基因型欧洲家系分支Ⅱ.1(北美分支)/B.1特征;另外4株基因完全相同,符合L基因型欧洲家系分支Ⅰ/B.1.1特征,此6株新冠病毒序列分属不同的进化分支,为两条不同的传播链。6株新冠病毒序列共有18个核苷酸突变位点,其中8个位点是同义突变,9个位点为错义突变,产生9个氨基酸突变位点,均发现RdRp-P323L、S-D614G重要变异位点。结论本研究中天津滨海新区新冠肺炎疫情为两起事件,6株新冠病毒序列分属不同的进化分支,为两条不同的传播链。提示可能来源于搬运工人接触了已污染新冠病毒的不同来源进口冷链物品。6株新冠病毒序列均有P323L、D614G突变,病毒突变、传播能力更强,应持续加强天津冷链重点从业人员及本土、输入性病例的监测。
Objective To analyze the whole genome traceability and variation analysis of SARS-CoV-2 in local COVID-19 outbreaks in Binhai New Area,Tianjin.Methods The whole-genome high-throughput sequencing was performed on throat swab samples collected from one local asymptomatic infected person and five confirmed cases of COVID-19 in Binhai New Area of Tianjin from November 7 to December 5,2020.The sequencing data were assembled by De novo.MAFFT v7.0 multiple sequence alignment program and MEGA X software were used to compare the above data and construct phylogenetic tree(Neighbor-joining method).Results The genetic similarity between the sequences of 6 SARS-CoV-2 strains and Wuhan reference sequence(Wuhan-Hu-1)was greater than 99.9%.Two of six strains were genetically identical,conform to the L-Lineage European BranchⅡ.1(America Branch)/B.1;The other four strains had the same genes and were in line with the characteristics of L-Lineage European BranchⅠ/B.1.1.These six strains belonged to different evolutionary branches and two different transmission chains.There were 18 nucleotide mutation sites in sequences of six SARS-CoV-2 strains,eight of which were synonymous mutation sites,nine of which were missense mutation sites,resulting in nine amino acid mutation sites,and important mutation sites of RDRP-P323L and S-D614G were found in all of the six samples.Conclusions In this study,there were two COVID-19 outbreaks in Binhai New Area of Tianjin,and the sequences of six SARS-CoV-2 strains belonged to different evolutionary branches and two different transmission chains.It might come from porters′contact with imported cold chain items contaminated with SARS-CoV-2 from different sources.All the sequences of six SARS-CoV-2 strains had P323L and D614G mutations,which indicated that the virus mutation and transmission ability were stronger.The surveillance of important employees of the cold chain in Tianjin and local and imported cases should be continuously strengthened.
作者
郑宝璐
高鑫
庄志超
苏承
邹明
于爱萍
谭昭麟
李晓燕
Zheng Baolu;Gao Xin;Zhuang Zhichao;Su Cheng;Zou Ming;Yu Aiping;Tan Zhaolin;Li Xiaoyan(Department of Pathogenic Microbiology,Tianjin Center for Disease Control and Prevention,Tianjin 300011,China)
出处
《中华微生物学和免疫学杂志》
CAS
CSCD
北大核心
2021年第8期581-587,共7页
Chinese Journal of Microbiology and Immunology
基金
天津市卫生健康委新冠肺炎防治科技项目(2020xkm01)
天津市科技计划项目(20JCZDJC00130)。
