狂犬病毒TaqMan PCR检测方法的建立

目的建立检测狂犬病毒（RV）核蛋白（N）基因片段的TaqMan PCR检测方法。方法针对RVN基因保守区域设计特异性引物与探针；优化检测体系中引物与探针的浓度；以体外转录的RV完整的N基因RNA作为定量分析模型；考核检测体系灵敏性、特异性、稳定性；初步用于RV的检测。结果引物和探针具有良好的特异性，使用浓度分别为0．6μmol／L和0．2μmol／L，可检测到2700个RNA拷贝数，较传统RT-PCR检测方法敏感性提高了10倍；同一样品Ct值重复检测5次，变异系数均〈5％，表明检测体系具有较好的稳定性；通过所建立的检测体系，绘制了以模板拷贝数为分析指标的RV定量检测标准曲线，对实验室内保存毒株的检测结果显示TaqMan PCR检测比普通PCR检测更快捷、敏感。结论所建立的RV TaqMan PCR可以用于RV的实验室检测，并且比普通PCR检测方法更灵敏、特异。     

扎伊尔型、苏丹型埃博拉病毒TaqMan探针实时定量PCR核酸检测方法的建立

目的建立针对扎伊尔型(ZEBOV)及苏丹型埃博拉病毒(SEBOV)特异、灵敏和快速的Taq Man探针实时定量PCR核酸检测方法。方法选用世界卫生组织(WHO)参比实验室所使用的引物和探针序列,建立针对扎伊尔型及苏丹型埃博拉病毒的NP基因序列保守区的Taq Man探针实时定量PCR核酸检测方法,验证检测方法的灵敏性、特异性和稳定性,并与常规PCR检测方法进行比较。结果所建立的实时定量PCR方法可用于ZEBOV及SEBOV的特异性检测,较传统PCR方法反应快捷、灵敏,分别可达:ZEBOV 34拷贝/反应、SEBOV 24拷贝/反应;具有良好的特异性、稳定性和可重复性。结论建立了ZEBOV及SEBOV Taq Man探针实时定量PCR核酸检测方法,该方法可有望用于埃博拉病毒(EBOV)的实验室、临床及现场核酸检测。     

miRNA分子在肺结核患者单核细胞中的表达及意义

目的分析肺结核患者(TB)外周血单核细胞中miR-34a-5p和miR-708-5p的表达水平,并探讨其临床诊断价值。方法选取TB患者和健康对照(HD)各25例,应用Taq Man q PCR技术测定两组人群外周血单核细胞中miR-34a-5p和miR-708-5p表达水平,以U6 sn RNA作为内参。应用ROC曲线评价miR-34a-5p和miR-708-5p诊断TB的临床意义。结果 miR-34a-5p在TB患者中的表达水平为(10.08±0.68),显著高于HD的(7.67±0.36),差异有统计学意义(P<0.01);miR-708-5p在TB患者中的表达水平显著高于HD的(13.52±0.98 Vs 7.71±0.57),差异有统计学意义(P<0.01)。ROC曲线分析表明在肺结核诊断中,miR-34a-5p的敏感性、特异性分别为72%、76%;miR-708-5p的敏感性、特异性为76%、76%。结论 miR-34a-5p和miR-708-5p分子在TB患者外周血单核细胞中异常表达,对TB辅助诊断具有一定参考价值。     

细粒棘球绦虫TaqMan实时荧光定量PCR检测方法的建立及应用

目的 为建立高效、特异的细粒棘球绦虫(Echinococcus granulosus,Eg)检测方法。方法 本研究设计了一组基于Eg线粒体基因的特异性引物和TaqMan探针,通过反应体系及条件的优化,建立了Eg荧光定量PCR检测方法。结果 该方法线性关系好,灵敏度高,在10⁹~10²拷贝/μL相关系数达0.998,灵敏度达10²拷贝/L;在特异性试验中,与其他病原虫株无交叉反应,特异性较好;重复性试验变异系数均低于3%。应用该方法对50份临床样品进行检测,发现6份为Eg感染阳性。结论 由此可见,建立的荧光定量PCR方法可快速、灵敏、特异地检测细粒棘球绦虫,具有一定的实际应用价值。     

A quantitative real-time RT-PCR assay for salmon IGF-I mRNA, and its application in the study of GH regulation of IGF-I gene expression in primary culture of salmon hepatocytes

The hormone insulin-like growth factor-I (IGF-I) regulates vertebrate growth. The liver produces most circulating IGF-I, under the control of pituitary growth hormone (GH) and nutritional status. To study the regulation of liver IGF-I production in salmon, we established a primary hepatocyte culture system and developed a TaqMan quantitative real-time RT-PCR assay for salmon IGF-I gene expression. A portion of the coho salmon acidic ribosomal phosphoprotein P0 (ARP) cDNA was sequenced for use as a reference gene. A systematic bias across the 96 well PCR plate was discovered in an initial IGF-I assay, which was corrected when the assay was redesigned. IGF-I mRNA levels measured with the validated assay correlated well with levels measured with an RNase protection assay, and were highest in liver compared with other tissues. We examined the time course of hepatocyte IGF-I gene expression over 48 h in culture, the response to a range of GH concentrations in hepatocytes from fed and fasted fish, and potential effects of variation in IGF-I in the medium. IGF-I gene expression decreased over time in culture in hepatocytes in plain medium, and in cells treated with 5 nM GH with or without a combination of metabolic hormones (1 microM insulin, 100 nM triiodothyronine, and 0.1 nM dexamethasone). GH stimulated IGF-I gene expression at all time points. In cells treated with GH plus metabolic hormones, IGF-I gene expression was intermediate between the controls and GH alone. Increasing concentrations of GH resulted in biphasic IGF-I gene expression response curves in cells from fed and fasted fish, with the threshold for stimulation from 0.5 to 2.5 nM GH, maximal response from 5 to 50 nM, and a reduced response at 500 nM. Medium IGF-I (5 nM) did not affect basal or GH stimulated IGF-I gene expression. This study shows that primary hepatocyte culture and the TaqMan IGF-I assay can be used to study the regulation of hepatic IGF-I gene expression in salmon, and provides the first evidence of a biphasic response to GH concentration in fish hepatocyte culture.     

Identification and quantification of the Acanthamoeba species and genotypes from reservoirs in Taiwan by molecular techniques

The occurrence of Acanthamoeba was investigated from 21 main reservoirs of Taiwan with 12 (57.1%) testing positive. Analysis of the 18S rRNA gene PCR product was performed in order to identify the Acanthamoeba isolates. Acanthamoeba spp. concentrations were determined according to TaqMan real-time qPCR. Acanthamoeba genotypes of all isolates were identified T4. The species were categorized to Acanthamoeba culbertsoni, Acanthamoeba polyphaga, Acanthamoeba castellanii and Acanthamoeba hatchetti. The concentration of Acanthamoeba spp. in detected positive reservoir water samples was in the range of 3.0–1.8 × 10³ cells/L. These results highlight the importance of Acanthamoeba in reservoirs of potential pathogens and its possible role in the spread of bacterial genera with interest in public and environmental health.     

应用多重TaqMan MGB探针实时聚合酶链反应检测A型和B型流感病毒的研究

目的 应用多重real-time PCR方法检测A型和B型流感病毒,探讨其在快速诊断流感病毒感染中的优越性.方法 根据A型和B型流感病毒M基因的相对保守序列,设计两套特异性引物和TaqMan MGB探针,进行多重real-time PCR检测A型和B型流感病毒.将该方法与病毒分离、免疫层析、传统RT-PCR进行比较,并对多重real-time PCR的特异性进行评估.并应用multiplex real-time PCR方法和常规的病毒分离方法对广东省流感样病例334份咽拭标本进行检测,比较其灵敏性和特异性.结果 多重real-time PCR反应可以检测到A、B型流感病毒的最低病毒量分别为10-1和10-3TCID50/反应.该方法在对流感病毒株以及其他呼吸道病毒株样品的检测中,未发现假阳性和假阴性现象,特异性为100%.该方法对334份临床标本进行检测,结果与经典检测方法(病毒分离鉴定结合血清学检测)的符合率达100%,且灵敏度明显高于病毒分离.结论 该研究建立的多重TaqMan MGB real-time PCR是一种快速、灵敏性和特异性高的流感病毒检测方法,对于流感的早期诊断及指导临床有重要意义.     

登革病毒TaqManMGB实时荧光定量PCR检测方法的建立及初步应用

目的建立登革病毒TaqMan实时荧光定量PCR快速检测方法及应用于临床。方法根据1～4型登革病毒3’端非编码区的一段高度保守序列,设计一套型通用的引物和TaqManMGB探针,以4个血清型登革病毒标准株为标准,以日本乙脑病毒和丙肝病毒作阴性对照,以包含登革病毒2型标准株（DENV-2NGC株）3’非编码区349bD片段的质粒DNA作标准品,对引物和TaqManMGB探针的特异性、灵敏度进行分析,从而建立登革病毒实时荧光定量PCR检测方法。用该法对登革病毒野毒株和10份登革病毒患者血清进行检测。结果TaqMan实时荧光定量PCR检测的1～4型登革病毒标准株及野毒株均为阳性,日本乙脑病毒和丙肝病毒均为阴性;检测灵敏度可达到每反应2个基因拷贝;检测的10份登革患者血清样本中,8份检测结果为阳性。结论TaqManMGB实时荧光定量PCR方法是一个快速、特异性强、敏感性高的检测登革病毒的方法,适用于登革病毒的临床早期诊断。     

鸭疱疹病毒1型实时荧光定量PCR方法的建立

目的建立检测鸭疱疹病毒1型(鸭瘟病毒)的实时荧光定量PCR方法,为快速诊断、致病机理研究及抗病毒药物筛选等奠定基础。方法根据病毒DNA聚合酶基因的序列,设计引物和探针,采用TaqMan探针技术进行实时荧光定量PCR,用含有125bp扩增产物的pMD18-T载体质粒为阳性对照,构建标准曲线,对该方法的特异性、可重复性、敏感性进行评价,同时与传统PCR方法进行比较研究。结果标准曲线表明在2.3×105~2.3×10拷贝数之间有很好的线性关系(r=0.999);实时荧光定量PCR最少可检测到23个阳性质粒,说明有很好的敏感性;试验内及试验间变异系数分别为1.22~6.69以及2.09~8.84,说明有较好的重复性;对非鸭瘟病毒DNA无扩增,说明有很好的特异性;在对病毒DNA的检测方面,比传统PCR的敏感性高出104倍。结论成功建立了针对鸭瘟病毒的特异、敏感、重复性强且可准确定量的实时荧光定量PCR方法。