一种快速检测HBV基因的荧光定量PCR法的建立

目的：利用二聚体蝎型荧光探针技术,建立一种能用于临床的快捷、敏感、特异、价格低廉的HBV实时荧光定量PCR检测方法。方法：根据HBV基因组保守区域precore／core设计二聚体蝎型荧光探针和引物,构建质粒标准品,优化荧光定量PCR条件,并进行方法学评价。结果：所建方法的检测范围为10^1～10^8 copies／μl,灵敏度达到10copies／μl,低拷贝样品的批内和日间重复性（CV）分别为1．71％和2．57％,高拷贝样品的批内和日间GV,分别为3．00％和3．86％。与商品化TaqMan试剂盒相比,本法阳性检出率较高,且检测时间缩短了45min（约减少1／3）,成本降低50％。结论：成功建立了快速检测HBVDNA的二聚体蝎型荧光定量PCR方法,为研发适合临床应用的HBV基因定量检测试剂盒奠定了基础。     

荧光定量PCR检测梅毒螺旋体方法的建立及初步应用

目的采用二聚体蝎型探针技术建立一种高敏感性和特异性的检测梅毒螺旋体(TP)的荧光定量聚合酶链反应(PCR)方法。方法根据TP特异性外膜蛋白Gpd的基因序列设计引物和荧光探针,采用基因工程技术构建可用于TP定量的标准品,优化荧光定量PCR的反应体系和反应条件,建立检测TP的二聚体蝎型探针定量PCR。采用本研究建立方法和商品化荧光定量PCR试剂盒检测40例临床标本,对比分析检测结果的统计学差异。结果成功构建了TP重组质粒标准品和TP的二聚体蝎型探针定量PCR,该方法线性范围为101~108 copy/mL,灵敏度为10copy/mL,特异性和敏感性均为100.0%;二聚体蝎型探针定量PCR对疑似梅毒病例阳性检出率显著高于目前商品化Taqman荧光定量PCR试剂盒(82.5%vs 62.5%,P0.05)。结论成功建立了二聚体蝎型探针荧光定量PCR快速检测TP的方法,为临床上TP的早期诊断和防控奠定了基础。     

新型二聚体突变荧光引物定量检测沙眼衣原体

目的 以二聚体突变荧光引物技术为基础建立对沙眼衣原体进行定量检测的新方法.方法 以沙眼衣原体主要外膜蛋白(MOMP)基因构建重组质粒作为DNA标准品,设计二聚体突变荧光引物,优化定量PCR体系并进行性能评价;同时对148例临床生殖道标本进行检测.结果 建立的二聚体突变荧光引物的定量PCR方法,其线性范围为101～109...     

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。     

新型TaqMan-MGB探针实时荧光定量PCR检测HCV-RNA方法学的建立

目的建立一种快速、准确定量HCV-RNA的实时荧光定量PCR检测方法。方法 Clustal X软件对HCV核酸序列进行比对分析,在HCV-RNA的保守区域5'UTR设计引物和探针,棋盘滴定法对实时荧光定量PCR体系进行性能优化,制作假病毒颗粒作为定量标准品对新建方法进行性能评价,并与临床常用HCV-RNA定量检测试剂盒进行比对分析,探讨其应用价值。结果建立HCV核酸定量高灵敏度方法,该方法可以检测1a,1b,2a,3a,3b,6a,6b等多个HCV基因型,检测HCV-RNA的灵敏度为50 IU/ml,精密度CV5%,检测结果可溯源至卫生部临床检验中心丙型肝炎病毒核酸(HCV-RNA)血清标准物质GBW09151a。新建方法与凯杰HCV-RNA荧光定量检测试剂盒同时检测40例临床样本,阳性一致率为100%,阴性一致率为56%;自建方法检测阳性的14个样本中,凯杰试剂0个阳性,表明自建方法的检测灵敏度要高于凯杰试剂。结论建立的HCV核酸定量新方法灵敏度高、特异性好、精密度高,可应用于临床。     

肺炎链球菌TaqMan实时荧光定量PCR的建立及临床应用

目的：建立TaqMan实时荧光定量PCR检测肺炎链球菌的方法,应用于临床儿童社区获得性肺炎（CAP）标本的快速筛查。方法根据 GenBank公布的肺炎链球菌自溶酶基因（lytA）设计引物和探针,建立实时荧光定量 PCR,并对体系进行优化;同时以痰培养法做双盲对照,应用于1504份 CAP患儿标本检测。结果 TaqMan实时荧光定量 PCR菌液的最低检出限可达18.75 cfu/PCR,无交叉反应,特异度好;对1504份儿童CAP标本检测,141份肺炎链球菌实时荧光定量PCR阳性,其中140份肺炎链球菌痰培养阳性,该方法灵敏度为100％,特异度为99.93％。从样品处理到结果报告仅需2.5 h。结论 TaqMan实时荧光定量PCR快速、简便、灵敏度高、特异度强,可用于儿童CAP中肺炎链球菌的初筛和指导抗生素的的合理使用。     

嗜肺巴斯德菌TaqMan MGB探针实时荧光定量PCR快速检测方法的建立及应用研究

目的 建立嗜肺巴斯德菌的TaqMan MGB探针实时荧光定量PCR快速检测方法.方法 针对嗜肺巴斯德菌16SrRNA基因设计特异性引物和探针,建立嗜肺巴斯德菌TaqMan MGB探针实时荧光定量PCR检测方法,并验证该方法的特异度、敏感度和稳定性.对2008～2011年采集的1 680份样本进行检测.结果 嗜肺巴斯德菌TaqMan MGB探针实时荧光定量PCR检测方法具有高度特异性,对多杀巴斯德菌、产气巴斯德菌、支气管鲍特杆菌、肺炎克雷伯杆菌、大肠埃希菌、铜绿假单胞菌均无交叉反应,检测灵敏度达22拷贝.标准曲线显示备浓度范围内具有良好的线性关系,相关系数为0.999,斜率为-3.488,PCR效率为100％.荧光定量PCR检测1 680份样本,检出137份嗜肺巴斯德菌阳性.该方法可直接从样本中特异性地检出嗜肺巴斯德菌.结论 TaqMan MGB探针实时荧光定量PCR方法具有灵敏、特异、稳定的特性,适用于嗜肺巴斯德菌的快速检测.     

自身猝灭探针定量PCR检测HCV方法的建立

目的 建立自身猝灭荧光探针定量PCR技术检测HCV方法.方法 构建重组质粒pMD18-T-HCV5'NCR作为标准品,并通过Sigma在线软件设计自身猝灭探针,优化定量PCR体系,并进行方法学评价.结果 建立了自身猝灭荧光探针的定量PCR方法,线性为101～1010copies/μl;灵敏度达50 copies/μl;批内CV为6.1%,批间CV为6.5%,日间CV为6.8%;特异性为100%,与其他肝炎病毒无交叉反应.与紫外定量方法比较,结果差异无显著性,且高度相关.结论 以自身猝灭荧光探针建立的HCV荧光定量PCR检测方法,灵敏度高、特异性强,为新型试剂盒的开发奠定了基础.     

实时荧光PCR监测HBV感染患者拉米夫定治疗病毒YMDD变异

目的 建立一种快速准确的实时荧光PCR方法检测HBV感染患者经拉米夫定治疗后YMDD变异情况.方法 首先用PCR法筛选HBV DNA阳性血清157例,HBV DNA含量为2.0×103～8.0×108拷贝/ml,HBV DNA阴性血清30例,然后采用TaqMan探针技术和选择性引物的实时荧光PCR对其进行YMDD变异检测.通过变异株和对照管的循环阈值(cycle threshold,Ct值)差来计算血清中总HBV中的YMDD变异株含量,并用PCR产物直接测序方法随机对69例HBV DNA阳性标本RT区进行基因序列分析,验证所建立方法的准确性.结果 187例接受拉米夫定治疗患者血清标本中,发生YMDD变异88例,其中YIDD变异39例,YVDD变异38例,YIDD与YVDD混合变异11例.突变株的含量为10%～100%.30例HBV DNA阴性血清的C管循环40次,69例测序结果显示68例两种方法检测结果完全相同,符合率为98.55%.结论 采用选择性引物和TaqMan探针技术建立实时荧光PCR方法能快速准确地检测YMDD变异情况,并能检测患者变异株在HBV总量中的比例,为临床使用拉米夫定治疗乙型肝炎病毒感染监测耐药性提供一种有效方法.     

丙肝抗HCV与HCV RNA定性、荧光定量之间的关系

自从1989年丙型肝炎病毒(HCV)正式命名以来,HCV研究即成为病毒性肝炎的热点之一。丙型肝炎呈全球分布,我国整体人群的流行率约为3%,而其慢性化率高达85%,其中20%患者易发展为肝硬化,且与肝细胞癌的发生密切相关犤1犦。血清HCVRNA阳性是HCV感染的直接依据,对丙肝的早期诊断具有重要意义。本文采用常规PCR定性、实时荧光定量PCR检测丙肝患者血清HCVRNA,并与ELISA夹心法测定抗HCV的结果相比较分析,认为HCVRNA荧光定量的检出率明显高于前两者,这可能与方法学敏感性、病毒感染所处的临床阶段、基因的突变及抗病毒药物的应用相关…     

Detection of hepatitis C virus RNA by a two-stage polymerase chain reaction with two pairs of primers deduced from the 5'-noncoding region

The 5'-noncoding region of hepatitis C virus (HCV) genomes is highly conserved. A two-stage polymerase chain reaction (PCR), involving two pairs of primers deduced from the 5'-noncoding region of the HCV genome, was developed for a sensitive and specific detection of HCV RNA. The first stage of PCR was performed for 35 cycles with primers capable of multiplying fragments of 221 base pairs. PCR products in samples negative for HCV RNA were subjected to the second stage of PCR for 30 cycles with primers located internal to those employed in the first stage of PCR. The two-stage PCR detected up to 10 chimpanzee infectious doses/ml of HCV, and HCV RNA in 11 (92%) of 12 sera from patients with chronic non-A, non-B hepatitis without detectable antibodies to HCV by a commercial assay kit. Primers from the 5'-noncoding region of the HCV genome would be suitable for detecting HCV RNA by PCR, since the other regions of the HCV genome diverge extensively in sequence because of its nature as an RNA virus.     

副溶血弧菌TaqMan双重实时-聚合酶链反应检测方法的建立

目的建立副溶血弧菌TaqMan实时-PCR和毒力基因TaqMan双重实时-PCR筛检的实验室检测方法。方法根据副溶血弧菌ItoxR/I基因的保守序列设计引物和TaqMan探针,建立检测副溶血弧菌的实时-PCR方法;根据副溶血弧菌耐热直接溶血素（thermostable direct hemolysin, Itdh/I）和耐热相关溶血素（thermostable related hemolysin, Itrh/I）基因的保守序列设计引物和探针,建立检测致病性副溶血弧菌毒力基因的双重TaqMan实时-PCR方法。对所建立的副溶血弧菌实时-PCR检测方法进行灵敏度和特异度评价。结果副溶血弧菌的检测下限为10sup2/sup拷贝/l,Itdh/I和Itrh/I双重实时PCR的检测下限为10sup2/sup拷贝/l。针对ItoxR/I基因建立的副溶血弧菌实时-PCR方法对11种其他弧菌和肠道细菌的染色体无扩增。结论建立的方法能够特异和敏感地检测副溶血弧菌,并能确定致病性副溶血弧菌的毒力基因,能作为副溶血弧菌的灵敏和快速检测方法。     

Clinical performance of the new rRoche COBAS TaqMan HCV Test and High Pure System for extraction, detection and quantitation of HCV RNA in plasma and serum

We evaluated the Roche COBAS TaqMan HCV Test For Use With The High Pure System (TaqMan HPS; Roche Diagnostics), for the extraction, detection and quantitation of hepatitis C virus (HCV) RNA in serum or plasma of HCV-infected individuals. The TaqMan HPS is a real-time PCR assay with a reported linear dynamic range of 3.0x10(1) to 2.0x10(8) HCV RNA IU/ml, and a reported lower limit of detection (LLD) of 10 IU/ml. Calculation of the HCV RNA titre is based upon an external standard curve in the presence of an internal control. Intra-assay and inter-assay variation were small in reference panel members with HCV RNA > or =100 IU/ml. Genotype performance and quantitative correlation between the TaqMan HPS and the bDNA (VERSANT HCV 3.0 assay; Bayer Diagnostics), assessed in 59 patient samples, were good for HCV genotype 1 but poor for genotypes 2, 3 and 4. For genotypes 2, 3 and 4, values obtained from the TaqMan HPS were in general 0.5 log lower than those from the bDNA. Sensitivity was poor in low viral titre samples of genotypes 1, 2, 3 and 4. The LLD (95%) was estimated at 41 HCV RNA IU/ml for genotype 4. The TaqMan HPS underestimates HCV RNA at all levels in plasma and serum from HCV-infected individuals, and the LLD should be reconsidered. This is clinically relevant because underestimation of HCV RNA levels during therapy may lead physicians into making incorrect treatment decisions.     

铕标记基因探针半定量检测丙型肝炎病毒RNA

目的 利用自行设计的引物、探针和新型铕螯合物BHHCT,建立一种半定量丙型肝炎病毒(HCV)RNA的检测方法。方法 收集44份丙型肝炎病人血清,20份正常人血清。利用中山大学达安基因有限公司RNA提取试剂提取HCV RNA,用自行设计的引物进行逆转录聚合酶链反应(RT-PCR)。扩增产物cDNA与微孔板上的捕捉探针杂交后,借助于其上游引物5′端带有的生物素,与标记有铕的链霉亲合素特异性结合,将铕连接到微孔板上,在特定波长激发光激发下,发出荧光,进行检测。结果 铕标记HCV RNA检测法的线性范围为102-106cDNA拷贝,敏感性、特异性均为100％。结论 铕标记RT-PCR检测HCV RNA法的线性范围宽,敏感性、特异性好,检测时间短,无放射性污染,有推广应用的价值。     

两种荧光定量法检测HCV RNA结果的比较

目的建立双探针荧光定量HCV RNA检测方法，分析其定量检测HCV RNA的灵敏度和特异性以及HCV RNA含量与患者病情的相关性。方法选取100例抗HCV抗体阳性患者，包括慢性肝炎患者45例、肝硬化患者30例、肝癌患者25例的样本，用双探针荧光定量法和两种商品荧光定量试剂方法进行HCV RNA检测，另观察近期196例抗HCV抗体阳性和48例抗HCV抗体阴性样本荧光定量PCR HCV RNA含量与肝功能的相关关系。结果荧光定量双探针法阳性率为93％（93／100）；两种商品荧光定量试剂方法阳性率分别为84％（84／100）和79％（79／100），经卡方检验差异有统计学意义（P〈0．05）。196例中抗HCV与HCV RNA阳性一致率为57．1％（116／196），其中伴肝功能改变49．0％（96／196）。HCV RNA含量与AST和ALT异常程度无显著相关性（P〉0．05），相关系数分别为0．4293及0．3899。HCV RNA高拷贝数患者肝功能异常率为85．2％（69／81），低拷贝数者肝功能异常率为40．9％（47／115），经卡方检验，X^2=38．63，差异有统计学意义（P〈0．001）。结论双探针荧光定量提高了HCV RNA检测的灵敏度和特异性，HCV RNA含量与患者肝功能损伤程度无明显相关性。     

New approaches to in vitro diagnosis of hepatitis C infection a reason for post transfusion hepatitis: Diagnostic value of determination of hepatitis C virus core antigen

In between the dates of February 2008–March 2009, by applying to Istanbul University CTF Microbiology and Clinical Microbiology Basic Sciences Branch and Duzen laboratories, 123 cases, where HCV RNA and anti-HCV positivity are identified with molecular (real-time PCR) and serologic (ELISA) methods as a positive control group, and 48 cases where HCV RNA and anti-HCV negativity are identified as a negative control group are established. The values of sensitivity, specificity, positive and negative approximation of recently developed HCV Core Ag (Abbott Diagnostics, Germany) kit are determined successively as 94.3%, 97.9%, 99.1%, 87%, 95.3% and 88%. Although the new HCV Ag assay is clearly not sensitive enough to replace HCV NAT it may serve as a valuable tool in the HCV diagnostic algorithm as it is able to pick up a great majority of anti-HCV and HCV RNA positive samples, thus allowing a timely and less expensive serological diagnosis of an active HCV infection. This may be an advantage for labs that do not have access to PCR easily.     

Enzyme-linked immunosorbent assay for antibodies against the capsid protein of hepatitis C virus with a synthetic oligopeptide

An enzyme-linked immunosorbent assay was developed for the determination of antibodies against the putative capsid protein of hepatitis C virus (HCV). A 36-mer oligopeptide with a sequence of RRGPRLGVRATRKTSERSQPRGRRQPIPKVRRPEGR (CP9) was synthesized; it was selected on the translation product of the presumptive HCV core gene, because of a high local hydrophilicity and excellent conservation by different HCV strains. The synthetic peptide was immobilized on a solid-support to capture antibodies directed to CP9 (anti-CP9) in test sera, which were detected by Fab' fragments of monoclonal anti-human IgG/gamma labeled with horseradish peroxidase. The specificity of anti-CP9 was confirmed by absorption tests. Anti-CP9 was detected in 13 (68%) of 19 patients with sporadic acute non-A, non-B (NANB) hepatitis and in 15 (83%) of 18 patients with post-transfusion acute NANB hepatitis. In 7 cases of acute NANB hepatitis who were followed, anti-CP9 developed earlier than antibodies against HCV (anti-HCV) detectable by a commercial assay kit. Among patients with chronic NANB liver diseases, anti-CP9 was detected in 103 (77%) of 133 with chronic hepatitis, 70 (62%) of 113 with liver cirrhosis and 31 (76%) of 41 with hepatocellular carcinoma. Anti-CP9 and anti-HCV overlapped in 175 (54%) among 324 cases of acute or chronic NANB liver diseases; 58 (18%) were positive only for anti-CP9 while 49 (15%) were positive only for anti-HCV. HCV RNA was detected, by amplifying HCV cDNA with polymerase chain reaction, in 10 of 11 sera positive only for anti-CP9. Among sera from 606 blood donors, 21 were positive only for anti-CP9. HCV RNA was detected in 5 (24%) of them, all of which had A492 values greater than 0.600 in ELISA for anti-CP9. Based on these results, anti-CP9 would complement anti-HCV for the diagnosis of HCV infection and contribute toward further decreasing posttransfusion NANB hepatitis.     

Rapid and reliable genotyping of HLA-B*27 in the Chinese Han population using a duplex real-time TaqMan PCR assay

ObjectivesTo develop a duplex real-time TaqMan PCR assay for genotyping HLA-B*27 in the Chinese Han population.Design and methodsA standard curve was constituted to deduce amplification efficiency, dynamic range and detection limit of the duplex real-time TaqMan PCR assay, whereas PCR-SBT (PCR with sequence-based typing) was used to evaluate the accuracy of the assay.ResultsA linear standard curve for determining HLA-B*27 was obtained within the range of 10¹–10⁹ copies per reaction with the correlation coefficient of 0.99 and amplification efficiency of 98.30%. The detection limit was 3.09 copies per reaction. Complete concordance was found between the results obtained by the duplex real-time TaqMan PCR assay and PCR-SBT. Fifty-nine of the 178 genomic samples were HLA-B*27 positive and the other 119 were HLA-B*27 negative.ConclusionsThe duplex real-time TaqMan PCR approach appears to be a reliable, sensitive, rapid and high-throughput method to genotype HLA-B*27 in the Chinese Han population.     

炭疽芽孢杆菌特异性基因序列双重TaqMan聚合酶链反应快速检测体系的建立

目的 以炭疽芽孢杆菌的主基因和致病毒素基因pagA特异性序列为检测标志，建立高敏感、高特异的荧光双重实时TaqMan聚合酶链反应快速检测体系。方法 根据炭疽杆菌主基因组特异性序列（Gs）和特异的毒力岛pagA基因序列（Pag）设计引物及探针，通过构建目的质粒获得标准模板，利用TaqMan标记探针和便携式Smartcycle实时聚合酶链反应检测平台探讨该检测体系的检测敏感性和特异性。结果该体系炭疽芽孢杆菌的检测敏感度为10^2拷贝每反应体系，与其他蜡样杆菌群细菌未出现非特异性扩增，具有较高的特异性。整个反应在1h内完成，适合于实验室或野外环境下炭疽芽孢杆菌的快速检测。结论 本研究建立的双重TaqMan实时聚合酶链反应检测体系可作为炭疽芽孢杆菌快速、准确、特异、敏感的检测手段。