鉴别伪狂犬病病毒野毒与疫苗毒荧光定量PCR方法的建立

Diagonsis Establishment of Fluorescen Quantitative PCR Assay for Pseudorabies Wild-type Virus and Vaccine Virus

摘要:

根据猪伪狂犬病病毒(PRV) gH、gE基因的序列, 设计了两对引物及其对应的TaqMan探针, 通过对引物、探针、Mg2+的浓度和样品DNA提取方法等进行优化, 建立了鉴别PRV野毒与疫苗毒感染的荧光定量PCR方法。该方法线性范围为101~108拷贝/mL, 达8个数量级, 灵敏度可达101拷贝/mL, 比常规PCR高100倍。用此方法对60份疑似组织样品进行检测, 并与血清中和试验、常规PCR相比较, 结果显示该方法具有快速、灵敏、特异、重复性好和能对样品进行定量检测等优点, 并且该法以闭管的模式操作, 减少了后续步骤污染的可能性, 整个PCR检测过程不到2 h。此方法的建立, 为猪伪狂犬病病毒的早期鉴别诊断和定量分析猪伪狂犬病病毒感染程度奠定了基础。

Abstract:

We designed two pairs of primers and their corresponding TaqMan probes according to gH, gE gene of PRV. By optimizing the probe’s concentration, Mg2+ concentration, primers concentration and sample DNA extraction, rea1-time fluorescent quantitative PCR (FQ-PCR) which can quickly identity field virus and vaccine virus of PRV was established. According to our results, the dynamic range of the FQ-PCR assay is between 10×101 copies/mL and 10×108 copies/mL, and the detection limit of FQ-PCR is 1.0×101 copies/mL, which is 100 fold higher than that of conventional PCR. We detected 60 doubtful tissue samples using the FQ-PCR assay, serum neutralization and conventional PCR. In conclusion, the FQ-PCR method is rapid, sensitive, specific and accurate, and can be used to detect field strains of PRV rapidly. The closed-tube format of the assay minimized the risk of contamination of subsequent reaction and the assay can be performed in 2 h or less. Development of real-time quantitative PCR provides the basis for the early and rapid detection and analyzing quantitatively the infectious degree of PRV.