摘要
目的对盐城市1起病毒性脑炎聚集性疫情分离的Echovirus18(E-18)型肠道病毒进行VP1基因分子进化特征分析。方法通过实时荧光RT-PCR方法,对2019年盐城市病毒性脑炎聚集性疫情标本进行肠道病毒的检测,对非EV71或CVA16其他肠道病毒进行分子分型,采用RT-PCR扩增E-18型肠道病毒VP1基因并测序,采用生物信息软件从核苷酸、氨基酸和分子进化3个层面进行分子特征分析。结果该起病毒性脑炎聚集性疫情是由E-18型肠道病毒感染引起,其6例病例;肛拭子肠道病毒核酸通用阳性4例,阳性率66.67%;均为轻症,全部治愈。4株E-18型肠道病毒株VP1基因片段均未见核苷酸的插入或者缺失,长度均为861bp、编码287个氨基酸,其核苷酸、氨基酸同源性分别为99.9%~100.0%和100.0%;与2019年E-18型手足口病盐城株(151/HFMD/JSYC/2019)VP1基因核苷酸、氨基酸同源性分别为99.5%~99.7%和100.0%;与原型株Metcalf VP1基因核苷酸、氨基酸同源性分别为79.0%~79.1%和93.4%。遗传进化树显示,2019年盐城市4株病毒性脑炎代表株与1株手足口病代表株聚集成簇,构成1个独立进化分支,属于C2基因亚群分支毒株。与原型株Metcalf相比,盐城市4株病毒性脑炎代表株涉及19个氨基酸位点的变异,变异率为6.62%,与1株手足口病代表株在VP1基因B-C loop区域发生了R84N氨基酸位点的变异。结论该起病毒性脑炎聚集疫情由E-18型肠道病毒引起,该病毒属于C2基因亚群优势进化分支,与本地手足口病代表株可能有共同的来源。
Objective To analyze the molecular evolution characteristics of the VP1 gene of Echovirus18(E-18)in a clustered viral encephalitis epidemic in Yancheng city.Methods The real-time RT-PCR method was used to conduct nucleic acid detection for samples collected in a viral encephalitis epidemic.The non EV71 or CVA16 enterovirus strains were subjected for molecular subtyping analysis.The VP1 coding regions of E-18 strains were amplified by RT-PCR followed by sequence analysis.The molecular characteristics of the VP1 regions were analyzed by bioinformation softwares at nucleic acid level,amino acid level and molecular evolution level.Results The viral encephalitis epidemic was caused by E-18 infection.The general positive rate of enterovirus nucleic acid of anal swabs of 6 cases was 66.67%(4 cases),and all 6 cases were mild patients and cured.No nucleotide insertion or deletion was found in the VP1 coding regions of the 4 E-18 strains,all had 861 bp and encoded 287 amino acids.The nucleotide and amino acid homologies were 99.9%-100.0% and 100.0%,respectively.Compared with 1 E-18 strain(151/HFMD/JSYC/2019)isolated from a hand foot mouth disease(HFMD)patients in 2019 and prototype strain Metcalf,the nucleotide and amino acid homologies were 99.5%-99.7% and 100.0%,79.0%-79.1% and 93.4%,respectively.Phylogenetic analysis showed the 4 E-18 strains isolated from the viral encephalitis epidemic and 1 strain from HMFD patient were clustered to form an independent evolution branch belonging to C2 subgroup.Compared with the prototype strain Metcalf,the 4 E-18 strains had mutations in 19 amino acid sites,resulting mutation rate of6.62%.The 4 E-18 strains and 1 HFMD strain all found R84 N mutation in B-C loop region.Conclusion The clustered viral encephalitis epidemic was caused by E-18 infection,which belongs to the dominant evolutionary branch of C2 gene subgroup and may share the same origin with the local HFMD representative strain.
作者
李春香
陈国清
王瑶
李峰
徐士林
李长城
LI Chun-xiang;CHEN Guo-qing;WANG Yao;LI Feng;XU Shi-lin;LI Chang-cheng(Yancheng Maternity and Child Health Care Hospital,Jiangsu Yancheng 224000,China)
出处
《江苏预防医学》
CAS
2021年第1期13-16,共4页
Jiangsu Journal of Preventive Medicine
基金
盐城市医学科技发展计划项目(YK2018022)。
