戊型肝炎病毒荧光定量RT-PCR快速检测技术的建立和初步应用

Development and Application of Real-time Quantitative RT- PCR Assay for the Detection of Hepatitis E Virus

摘要:

利用DNAMAN软件对GenBank登录的戊型肝炎病毒四个主要基因型代表株的序列进行分析, 选择其高度保守的ORF2区域设计合成引物和探针, 并用包含有扩增区域的核苷酸片段进行体外转录制备标准品cRNA。在对荧光定量RT-PCR的反应条件优化的基础上, 建立了适用于戊型肝炎病毒主要基因型检测的荧光定量RT-PCR检测技术。该检测技术可以有效检测I型和IV型戊型肝炎阳性病料, 而对猪的其它几种疫病阳性病料则为阴性结果, 证实本技术的特异性强、可靠性好。对阳性标准品的检测结果表明, 所建立的TaqMan荧光定量RT-PCR灵敏度可达2.0×101拷贝/反应, 相比于巢式RT-PCR方法, 其灵敏度高10~100倍以上。在对54份临床样品的检测中, 进一步证实了该方法快速、灵敏且重复性好, 可满足戊型肝炎病毒早期快速诊断的需要。

Abstract:

Hepatitis E virus (HEV) sequences including four major genotypes representative strains available in GenBank were aligned with the DNAMAN software. The highly conserved internal region of ORF2 was then subjected to design primers and a probe. Furthermore, a 0.3 kb fragment of HEV ORF2 containing the amplification region was transcribed in vitro to synthese cRNA standard and a universal real-time TaqMan PCR assay was optimized and developed to detect and quantify main genotypes RNA of HEV. The specificity and reliability of the real-time RT-PCR was confirmed by testing genotype I HEV, genotype IV HEV and clinical samples. The detection limit of real-time RT-PCR was found 2.0×101 copies per reaction using in vitro transcribed cRNA. Compared with nested RT-PCR in diagnosis of HEV, the real-time RT-PCR developed was 10 to 100-fold more sensitive than the nested RT-PCR. The detection results from 54 clinical specimens indicated real-time RT-PCR was a rapid, sensitive and reproducible diagnostic method for HEV. This assay will be useful as an early and rapid diagnostic assay for HEV.