目的:戊型肝炎病毒(hepatitis E virus，HEV)属于戊型肝炎病毒科(Hepeviridae)，包括四个属，即HEV-A、-B、-C和-D。HEV是一种正单链，长约7 kb的裸露RNA病毒，可以引起急、慢性戊型肝炎，特别是孕妇感染HEV后死亡率较高。目前，普遍认为只有HEV-A对人类具有致病性。然而，近期在中国香港、西班牙和中非等地区陆续报告由HEV-C，即鼠戊型肝炎病毒感染引起的戊型肝炎病例，说明HEV-C也是一种人兽共患病毒，可传染于人类。在前期工作中，课题组从海南省澄迈县捕获的褐家鼠粪便中检测到了HEV-C基因部分片段。为进一步了解海南HEV-C基因分子特征，本研究中扩增了HEV-C全长基因，并对其进行了系统发育分析。方法:使用Trizol试剂从海南省澄迈县捕获的褐家鼠粪便中分离HEV RNA，并利用Oligo dT引物进一步转录合成cDNA。接着用PCR方法扩增HEV的四个ORF区，并用Sanger法测序，拼接全长HEV基因。利用MEGA X软件的Clustal W方法与参考序列进行比对，并构建系统进化树。结果:通过系统进化树分析发现本研究中扩增的HEV-C为C1型，与广东省湛江市褐家鼠中发现的HEV-C1(基因号:LC549184)的同源性是93。1%，但与我国云南省、香港特别行政区和湖北省等地区的同源性比较远，分别为65。7%、65。9%、85。4%。结论:本研究首次针对海南省褐家鼠携带HEV-C1全长基因进行了系统进化分析。该研究结果提示海南省存在HEV-C的鼠-人传播的潜在风险。因此，应继续控制鼠类的同时，也应预防鼠HEV传染人类的风险。
Genetic evolutionary analysis of a rat hepatitis E virus from Hainan Province
Objective:Hepatitis E virus(HEV)is a member of Hepeviridae that has a positive sense,single-stranded approxi-mately 7 kb-long RNA.HEV can be divided into four genera:HEV-A,-B,-C and,-D.HEV-A is known to be pathogenic to hu-mans.However,the genetically highly divergent rat origin HEV(HEV-C),which was originally considered only to infect ro-dents,was also reported to infect humans in Hong Kong China,Spain,and central Africa as well as in nonhuman primates,imply-ing a possibility of rat HEV transmission to human.From our preliminary study,we have detected a HEV-C gene in rat feces col-lected from Chengmai City,Hainan province.Here,we extensively studied the molecular characteristics of a rat HEV whole ge-nome denoted ratHEV-HMU-8.Methods:Viral RNA was isolated from rat feces using Trizol reagent and was further reversely transcribed into cDNA using Oligo dT primer using commercial reagent according to the manufacturer's instructions.Each ratHEV ORF region was amplified with PCR and the nucleotide sequences were determined by the Sanger sequencing method.Obtained ORF sequences were assembled to build a full-length ratHEV genome.Sequence alignment was performed with the Clustal W method and the ratHEV-HMU-8 genotype was further verified by a maximum likelihood method with 1000 iterations of bootstrap sampling using DNAstar software.Results:Based on phylogenetic analysis,the HEV-C gene studied here was identi-fied as the genotype HEV-C1 subgenotype and genetically close to the HEV-C1 from Zhanjiang City(GenBank No.LC549184),the genetic identity is 93.1%.However,the genetic homology is low when compared with the reference from Yunnan Province,Hubei Province,and Hong Kong China,the genetic identity is 65.7%,65.9%,and 85.4%,respectively.Conclusions:In our study,the first full-length genome of rat HEV-C1 from Hainan province was isolated and analysis by phylogenetic analysis,imply-ing the potential risk of HEV-C rat-to-human transmission that would cause rat HEV infection in Hainan.Thus,the prevalence of rat HEV in domestic animals and humans should be investigated to prevent or warn of a possible outbreak of rat HEV infection in the future.
万方数据
维普
