牛轮状病毒实时荧光定量PCR检测方法的建立及应用

Establishment and application of a real‑time fluorescent quantitative PCR assay for Bovine Rotavirus

  • 摘要: 基于NCBI数据库中牛轮状病毒 (Bovine rotavirus,BRV) VP7基因的保守序列设计特异性引物,通过优化反应体系与扩增条件,建立BRV SYBR Green Ⅰ RT‑qPCR检测方法。实验结果表明,最佳退火温度为52 ℃,引物最佳终浓度为0.8 μmol/L;在3.16×103~3.16×107 copies/μL的DNA拷贝数范围内,模板浓度与Ct 值呈良好线性关系(R2=0.998 9),最低检测限为3.16×10¹ copies/μL,较常规PCR方法的灵敏度提升约100倍。特异性与重复性验证显示,该方法仅对BRV产生特异性扩增带,犊牛腹泻常见病原均未出现非特异性扩增信号;组内与组间变异系数均小于1%。对60份疑似BRV感染的粪便样品进行检测,阳性检出率为21.7%,显著高于常规PCR方法的13.3%。综上,所建立的RT‑qPCR方法具有高特异性、灵敏度和重复性,可用于BRV的临床快速检测及诊断试剂盒的研发。

     

    Abstract: Specific primers were designed based on the conserved sequences of the VP7 gene of Bovine rotavirus (BRV) retrieved from the NCBI database. By optimizing the reaction system and amplification conditions, a SYBR Green Ⅰ RT‑qPCR assay for BRV detection was established. Experimental results showed that the optimal annealing temperature was determined as 52 °C and the optimal final concentration of the primers was 0.8 μmol/L. A good linear relationship (R²=0.998 9) was observed between the template concentration and the Ct value within the range of 3.16×10³~3.16×107 copies/μL, with the minimum detection limit of 3.16×10¹ copies/μL, which represented a 100 fold increase in sensitivity compared with the conventional PCR method. Specificity and repeatability verification tests indicated that the established assay produced specific amplification bands only for BRV, and no non‑specific amplification signals were detected for other common pathogens causing calf diarrhea. The coefficients of variation (CVs) of both intra‑assay and inter‑assay were less than 1%. A total of 60 fecal samples suspected of BRV infection were detected, and the positive detection rate was 21.7%, which was significantly higher than that of the conventional PCR method (13.3%). In conclusion, the established RT‑qPCR assay exhibited high specificity, sensitivity and repeatability, and could be applied for the rapid clinical detection of BRV and the development of diagnostic kits.

     

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