辛德毕斯病毒荧光PCR检测方法的建立

Detection of Sindbis virus-specific nucleic acid with SYBR GREEN Ι real time PCR assay

目的建立辛德毕斯病毒核酸的SYBRGREENΙ荧光PCR检测方法。方法根据辛德毕斯病毒基因组核苷酸序列特性设计引物。病毒在BHK21细胞上繁殖扩增后提取RNA和逆转录。以病毒cDNA为模板分别进行SYBRGREENΙ荧光PCR和常规RTPCR扩增,并对SYBRGREENΙPCR法的灵敏性、特异性、重复性等进行分析。结果最适退火温度为55℃,最适引物浓度为0.5μmol/L。用该方法检测2株SIN病毒株YN87448和XJ160结果均为阳性,而对其他虫媒病毒如甲病毒属Geta病毒、乙脑病毒、Batai病毒、Banna病毒、环状病毒及西方马脑炎病毒合成模板检测时结果均为阴性。根据病毒空斑形成实验结果,将YN87448病毒悬液进行连续10倍稀释后分别用常规PCR和SYBRGREENΙ荧光PCR方法进行检测。结果SYBRGREENΙ荧光PCR检测敏感性比常规PCR方法要高近100倍,检出下限可达0.1PFU/ml。对模拟感染的人血清标本检测结果表明人血清中成分对检测体系无明显影响。对151份不明原因发热和病毒性脑炎患者的血清或脑脊液标本进行检测,结果检测到6份标本阳性。结论本实验建立了辛德毕斯病毒特异性核酸的SYBRGREENΙ荧光PCR检测方法,实验结果显示了较好的特异性、广谱性,初步证实可应用于临床标本的检测,为将来用于临床和调查辛德毕斯病毒在我国的流行情况提供了新的技术手段。

Objective To develop a rapid, specific and sensitive method for detecting Sindbis virus （SINV） with SYBR GREEN Ⅰ real time PCR. Methods Total RNA of strains of Sindbis virus and a related virus were extracted and reverse transcribed to cDNAs. With the cDNAs as template, the SYBR GREEN Ⅰ real time PCR assay was developed and optimized on ABI 7300 apparatus for specific-detection of Sindbis virus, and the sensitivity, specificity and reproducibility were evaluated. Results For the PCR, 55℃ was chosen as the optimal anneal temperature and 0. 5 μmol/L as the optimal primer concentration. Using this method, all the selected SINV were detected as positive, while the results of control arboviruses such as Geta virus, Japanese encephalitis virus （JEV） , Batai virus, Seadomavirus, Orbiviruses and synthesized WEEV cDNA were negative. With this system,0. 1 PFU/ml SINV cDNA could be detected; The sensitivity of this assay was about 100 times higher than standard RT-PCR. All the results were reproducible within two compatible tests, and the stability of the detection system was very good. The test results of simulated infection human serum samples showed that human serum had no obvious interference with this system. With this system, 6 of 151 clinical samples with unknown fever or encephalitis were determined as positive. Conclusion The developed SYBR GREEN I real time PCR assay for detecting Sindbis virus was highly sensitive, specific and showed a good reproducibility and stability. It is our belief that the present method can be further used in clinic sample to verify its stringency.