湖北地区人源与猪源戊型肝炎病毒部分基因序列的分析

Partial sequence analysis of hepatitis E virus isolated from patients and pigs in Hubei,China

目的调查湖北地区戊型肝炎病毒(HEV)人源与猪源基因型的流行情况。方法用套式RT-PCR方法对湖北地区25例急性戊型肝炎患者血清和33份用实时荧光RT-PCR检测为HEV核酸阳性的猪血清进行HEV RNA检测。HEV核酸使用QIAamp Viral RNA Mini Kit(QIAGEN)提取,用AMV ReverseTranscriptase(Promega)进行逆转录合成cDNA,所用扩增引物为基于HEV ORF2区域的简并引物,并对阳性产物进行克隆测序,对所得序列进行同源性比较和进化树分析。结果用RT-PCR从25份急性戊型肝炎患者血清和33份猪血清中分别检出HEV RNA阳性者9份和8份。序列分析显示17株戊型肝炎病毒株在ORF2部分区域的核苷酸序列同源性为82%～100%,氨基酸同源性为87%～100%。该17株戊型肝炎病毒序列与HEV 4型代表株的核苷酸序列的同源性为82%～94%,均为HEV 4型,而且人源和猪源HEV均分为相同的4个亚型。进化树分析显示该17株戊型肝炎病毒株分属于4个不同的亚型分支。结论湖北地区人与猪群中流行的HEV基因型以及亚型相同。

Objective To investigate the prevalence of hepatitis E virus（HEV）genotypes in patients and pigs in Hubei province of China.Methods HEV infection was confirmed in 33 pigs and 25 patients by using the nested RT-PCR.Serum RNA was purified from serum samples using QIAamp Viral RNA Mini Kit（QIAGene）and nested RT-PCR was performed to identify HEV sequences using degenerate oligonucleotide primers corresponding to partial region of ORF2.The positive PCR products were cloned and sequenced.Results Nine and eight samples were detected positive from 25 patients and 33 pigs,respectively.The obtained 17 sequences share 82%-100% and 87%-100% identity with each other at the nucleotide level and amino acid level,respectively.All of the virus strains were classified into HEV genotype 4 based on their homology（82%-94%）with the reference sequence.Four identical subtypes were identified from both human and pig samples.Conclusions Same genotypes and subtypes of HEV were prevalent in both patients and pigs in Hubei province of China.