Different real-time PCR formats compared for the quantitative detection of human cytomegalovirus DNA.

BACKGROUND: The aim of this study was to compare the ABI PRISM 7700 Sequence Detection System and the LightCycler to develop a quantitative real-time PCR assay for the detection of human cytomegalovirus (HCMV) DNA suitable for routine hospital application. METHODS: We used one exonuclease probe and five different hybridization probe sets as sequence-specific fluorescence detection formats. For the exonuclease assay and two hybridization probe sets, reproducibility and the detection limit were determined. To keep the total assay time to a minimum, we gradually shortened individual reaction steps on both instruments. RESULTS: The exonuclease assay can be interchangeably performed on the 7700 and the LightCycler. No change of reaction conditions is required, except for the addition of bovine serum albumin to the LightCycler reaction. The shortest possible total assay time is 80 min for the ABI PRISM 7700 Sequence Detection System and 20 min for the LightCycler. When the LightCycler is used, the exonuclease probe can be replaced by a set of hybridization probes. All assays presented here detected HCMV DNA in a linear range from 10(1) to 10(7) HCMV genome equivalents/assay (r >0.995) with low intraassay (<5%) and interassay (<10%) variation. CONCLUSIONS: The ABI PRISM 7700 Sequence Detection System as well as the LightCycler are useful instruments for rapid and precise online PCR detection. Moreover, the two principles of fluorescence signal production allow HCMV quantification with the same accuracy.     

p53基因第8外显子实时荧光PCR方法的建立

目的建立实时荧光定量聚合酶链反应(PCR)检测p53基因第8外显子的方法。方法用酚-氯仿抽提法提取云南省中医院的常规体检患者的DNA,应用SYBR GreenⅠ作荧光染料,通过检测PCR产物中荧光讯号的强度来定量p53基因,重复测定该标本18次,以此建立检测p53基因的实时荧光定量PCR方法。结果融解曲线分析表明该方法特异可靠。结论该研究建立了p53基因实时荧光定量PCR检测方法,该方法简便、特异、重复性好、可信度高,为p53基因第8外显子的定量研究提供了理想的检测方法。     

实时荧光定量-聚合酶链反应方法检测肺炎支原体

目的 建立一种快速、灵敏、特异的肺炎支原体实时荧光定量-聚合酶链反应(real-time PCR)检测方法,以期用于临床肺炎支原体感染检测。 方法 通过测序分析和序列比对,选取肺炎支原体p1基因中保守区域设计特异性引物和荧光探针,建立和完善此real-time PCR检测方法,并进行扩增效率、灵敏度及特异度评价。与已报道的肺炎支原体常规聚合酶链反应(PCR)方法进行150份临床标本检测能力比较。 结果 建立的real-time PCR方法对肺炎支原体的检测限约为10 cfu。使用该方法对9株肺炎支原体ATCC标准株和30株临床分离株核酸扩增均为阳性;对10种其他支原体、13种常见呼吸道病原菌染色体及人类染色体扩增结果均为阴性。同时,临床标本的检测结果显示该方法检测灵敏度优于常规PCR。 结论 本研究建立的real-time PCR方法可快速、灵敏、特异地检测标本中肺炎支原体核酸,可适用于临床肺炎支原体诊断。     

TaqMan实时荧光定量PCR检测肺炎链球菌

目的利用实时荧光定量聚合酶链反应（实时PCR）方法进行肺炎链球茵的检测和流行病学调查。方法用实时PCR技术扩增并检测400例临床标本的肺炎链球菌的自溶素（1yt）基因,并将其与传统的培养法进行对比。结果400例,临床标本中,实时PCR检测肺炎链球菌为阳性的有78例（阳性率为18％）,传统培养法结果为阳性的有29例（阳性率为7．25％）。结论实时PCR是一种灵敏、特异、快速的检测肺炎链球菌方法,其可用于肺炎链球菌的诊断和流行病学调查。     

荧光定量PCR方法在空肠弯曲菌检测中的应用

空肠弯曲菌是引起人类食源性疾病的主要病原菌之一。快速、特异检测方法的建立对于该病原菌感染的诊断及鉴别诊断具有重要意义。荧光定量PCR方法作为一种快速诊断方法已经广泛应用于空肠弯曲菌的检测及鉴定。本文从荧光定量PCR方法在空肠弯曲菌病原检测中的建立、发展以及应用等方面进行综述。     

Quantitative real-time PCR for cancer detection: the lymphoma case

Advances in the biologic sciences and technology are providing molecular targets for diagnosis and treatment of cancer. Lymphoma is a group of cancers with diverse clinical courses. Gene profiling opens new possibilities to classify the disease into subtypes and guide a differentiated treatment. Real-time PCR is characterized by high sensitivity, excellent precision and large dynamic range, and has become the method of choice for quantitative gene expression measurements. For accurate gene expression profiling by real-time PCR, several parameters must be considered and carefully validated. These include the use of reference genes and compensation for PCR inhibition in data normalization. Quantification by real-time PCR may be performed as either absolute measurements using an external standard, or as relative measurements, comparing the expression of a reporter gene with that of a presumed constantly expressed reference gene. Sometimes it is possible to compare expression of reporter genes only, which improves the accuracy of prediction. The amount of biologic material required for real-time PCR analysis is much lower than that required for analysis by traditional methods due to the very high sensitivity of PCR. Fine-needle aspirates and even single cells contain enough material for accurate real-time PCR analysis.     

食品中志贺活菌叠氮溴乙锭实时荧光聚合酶链反应技术研究

目的 利用叠氮溴乙锭（ethidium monoazide bromide,EMA）实时荧光聚合酶链反应（PCR）技术,建立一种简便、快速、特异、灵敏的在食品中检测志贺活菌的方法。方法 根据志贺菌ipaH基因保守序列设计特异性引物和探针。用不同EMA浓度、不同光照次数优化样品EMA前处理条件。用已知菌验证志贺活菌检测的敏感性和志贺死菌检测的抑制性。用31株志贺菌、26株单增李斯特菌、24株沙门菌、25株副溶血弧菌、11株阪崎肠杆菌、10株致病性大肠埃希菌和1株大肠埃希菌验证方法的特异性和稳定性。同时用本研究方法和常规分离培养法,对30件模拟样品进行实样验证。结果 志贺活菌EMA实时荧光PCR方法的循环阈值（Ct）=32.10~3.19log（菌量）（R2=0.994）。最低检测浓度为2.20 CFU/反应。对死菌DNA抑制效率99.97%。31株志贺菌Ct值最低为15.04,最高为26.54,而97株非志贺菌的Ct值均35或无Ct值（呈一条直线）。重复试验Ct值变异系数3。30件模拟样品采用本研究方法和常规分离培养法的检测结果一致,但采用EMA实时荧光PCR方法耗时不超过7.5 h,而常规分离培养方法则需要3～5 d。结论 EMA实时荧光PCR技术是一种快速简便、特异性强、灵敏度高、仅检测志贺活菌的方法,建议在食品检测中推广应用。     

分子信标荧光探针检测结核分枝杆菌的临床应用

目的:探讨分子信标荧光探针检测结核分枝杆菌的临床应用价值。方法:应用设置内参照的分子信标荧光探针检测178例肺结核标本,并与痰涂片和培养结果进行比较。结果:肺结核组分子信标荧光探针阳性率显著高于痰涂片和培养,检出率分别为56.2%(100/178),34.8%(62/178)、34.8%(62/178)。结论:分子信标荧光探针具有较高的灵敏度和特异度,对结核病的辅助诊断有一定的临床意义。     

类志贺邻单胞菌实时荧光TaqMan PCR快速检测体系的建立

目的建立针对类志贺邻单胞菌的高灵敏、高特异的实时荧光TaqMan聚合酶链式反应(PCR)快速检测体系。方法根据类志贺邻单胞菌23S rRNA基因的一段特异性序列设计引物及TaqMan探针,利用实时荧光PCR检测平台探讨该检测体系的灵敏度;用30种其他肠道致病菌及院内感染中常见的致病菌评价该检测体系的特异性。结果实时荧光TaqMan PCR快速检测体系对类志贺邻单胞菌重组质粒的检测灵敏度为1×102拷贝/反应体系;对类志贺邻单胞菌基因组的检测灵敏度为3×10-2pg/反应体系;该检测体系在检测30种其他肠道致病菌及院内感染中常见的致病菌时未出现特异性扩增,整个反应在2 h内完成。结论本研究建立的实时荧光TaqMan PCR检测体系可作为类志贺邻单胞菌灵敏、特异、快速的检测方法。     

实时荧光PCR技术在手足口病检查中的应用

目的采用实时荧光聚合酶链反应(PCR)法检测手足口病患儿病原体。方法收集433例疑似手足口病患儿的粪便标本进行肠道病毒通用型、肠道病毒71型(EV-71)和柯萨奇病毒16型(CA-16)鉴别与分析。结果实时荧光PCR法检测433例患儿肛拭子标本使用通用型试剂盒检出366例阳性,其中66例为EV-71感染,151例为CA-16感染。结论 EV-71和CA-16肠道病毒是手足口病的主要病原体,该地区2011年以CA-16感染为主,实时荧光PCR技术对手足口病的病原诊断具有重要价值。     

荧光定量聚合酶链反应检测常见致病真菌方法的建立

目的建立快速的检测临床致病真菌的荧光定量聚合酶链反应(PCR)方法。方法使用真菌的通用引物ITS86和ITS4,检测临床常见的致病性真菌,并观察检测方法的敏感性和特异性。结果建立的荧光定量PCR可以准确地检测念珠菌属、曲霉菌属和新型隐球菌等常见的致病真菌,白色念珠菌的敏感性为0.87fg,光滑念珠菌的敏感性为4.2fg,与细菌和人类基因组DNA以及病毒DNA均无交叉反应,根据融解曲线的Tm值可以进行菌种的初步鉴定。结论荧光定量PCR方法检测真菌的敏感性和特异性好,可以应用于临床进行快速检测。     

实时荧光定量PCR法与常规PCR法及细菌培养法检测副溶血弧菌的比较

目的:比较实时荧光定量PCR法、常规PCR法及细菌培养法检测副溶血弧菌的灵敏度与特异性。方法:采用建立的实时荧光定量PCR、常规PCR及传统细菌培养法3种方法,同时对副溶血弧菌等细菌进行检测。结果:实时荧光定量PCR检测的灵敏度可达19cfu/mL,且有很高的特异性,对金黄色葡萄球菌等10种相关细菌均无交叉反应,从细菌核酸提取至完成检测仅需3h左右。结论:实时荧光定量PCR检测由于在密封环境中进行,避免了产物与环境间的交叉污染,是3种方法中最为快速敏感的方法,适用于公共卫生应急疫情的实验室快速诊断。     

Comparison of real-time PCR and MassTag PCR for the multiplex detection of highly pathogenic agents

Multiplex PCR assays are a cost- as well as labour-effective way to analyse one sample for several pathogens simultaneously. Besides the mutual competition of the individual PCR reactions included in a multiplex PCR assay, their specific read-out displays a limiting factor for the total number of PCR reactions that can be multiplexed. In this study, two PCR systems with different read-out approaches are compared, using a pentaplex PCR assay for the detection of highly pathogenic agents. A pentaplex assay was used since five represents the current limit of real-time PCR multiplexing capacity due to the low resolution of fluorescence emission peaks of the current equipment. In contrast, MassTag PCR as a quite new technique offers the possibility to detect up to 20-30 target sequences from one reaction. After extensive and separate optimisation of the PCR protocol for both platforms, a comparative probit analysis showed good sensitivities for MassTag and real-time PCR detection. Nevertheless, the detection limits of MassTag PCR have been undercut by the real-time PCR for each target. We therefore conclude that MassTag PCR is a useful diagnostic technique for the sensitive screening for pathogens by highly multiplexed PCR assays, but cannot reach the sensitivity of real-time PCR for lower multiplexed PCR assays.     

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。     

Successful nanolitre real-time PCR detection of respiratory pathogens in clinical specimens

We performed a proof-of-concept study to determine if human pathogens could be detected in clinical specimens using nanolitre-volume real-time PCR. Nanolitre PCR for Bordetella pertussis/B. parapertussis and respiratory syncytial virus (RSV) was performed on nasopharyngeal specimens and results compared with conventional methods. B. pertussis/B. parapertussis nanolitre PCR detection was 100% sensitive (20/20; 95% CI, 84-100%) and 100% specific (26/26; 95% CI, 87-100%). RSV nanolitre PCR was also 100% sensitive (21/21; 95% CI, 85-100%) and specific (25/25; 95%, CI 87-100%). Respiratory pathogens can be successfully detected in clinical specimens using nanolitre-volume PCR.     

实时荧光定量聚合酶链反应检测血清2型猪链球菌的研究

目的 基于TaqMan-MGB探针实时荧光定量聚合酶链反应(Real.time PCR)技术,建立针对血清2型猪链球菌的快速检测方法.方法 针对血清2型猪链球菌的csp2J基因序列,应用Beacon Designer 7.0,设计了引物和TaqMan-MGB探针,建立Real-time PCR检测方法;把目的 片段克隆...