24重荧光real-time PCR技术在食物中毒快速检测中的应用

目的:应用24重荧光real-time PCR检测技术快速筛检食物中毒病原菌,结合国家标准中的培养法探讨24重荧光real-time PCR检测技术符合性和应用价值。方法:采用高灵敏度、高特异性的24重荧光real-time PCR检测技术作为中毒病原菌的初筛方法,国标方法进行细菌分离培养,并对分离出的病原菌进行生化鉴定。结果:5份食物中毒患者肛拭子在增菌前检出4份霍乱弧菌核酸(非O1/非O139群,24重荧光real-time PCR),9份患者肛拭子在增菌后检出5株霍乱弧菌(非O1/非O139群,国标培养法),其中包含4份PCR技术初筛阳性样品,两个方法的符合率为80%。所有样本均未检出沙门氏菌、志贺菌、副溶血性弧菌、致泻性大肠埃希菌以及金黄色葡萄球菌。结论:应用24重荧光real-time PCR检测技术同时检测24种常见致病病原菌,能高效锁定中毒病原菌。将其与国标培养法相结合,对临床治疗和食物中毒快速处置能起到积极作用,值得应用和推广。

Detection of Ratoon Stunting Disease in Virus-free Seedcane via Real-time Fluorescence Quantitative PCR

This study was to develop the real-time fluorescence quantitative PCR technique for detecting the ratoon stunting disease （RSD） in virus-free seedcane seedlings. Healthy tissue culture seedlings were obtained from six plants of sugarcane ROC22, which had been confirmed RSD-positive by detecting the sugarcane juice, by employing the sugarcane seedlings production protocol. Real-time fluorescence quantitative PCR was used to detect RSD pathogens in tissue culture sam- pies. The results showed that target fragment of RSD pathogens was not found in all 10 samples in real-time fluorescence quantitative PCR, with the Ct values of 37 - 39. The healthy tissue culture sugarcane seedlings do not carry RSD pathogens, indicating that adopting healthy seedcane seedlings production technique could thoroughly get rid of RSD pathogens.

Synchronous Detection of DNA/RNA of Four Shrimp Viruses by Real-time Fluorescence Quantitative RT-PCR

[ Objective] This study aimed to establish a simultaneous detection method of shrimp viruses by real-time fluorescence quantitative RT-PCR, to improve the efficiency of inspection and quarantine. [ Method] A novel real-time fluorescence quantitative RT-PCR assay was established and optimized for simultaneously detecting DNA/RNA of four shrimp viruses （WSSV, IHHNV, TSV and YHV ）. [ Result] The optimized real-time fluorescence quantitative RT-PCR system gener- ated typical amplification curves with high amplification efficiencies （E = 1.06, 1.07, 0.92 and 0.92, respectively）, good hnear relationship （ r = 1 ）, uniform repeatability （ standard deviation = 0.05 - 0.46 ; variation coefficient = 0.26% - 1.62% ） and high sensitivity, exhibiting no significant differences compared with re- al-time fluorescence quantitative PCR （average error of Ct value = 0.04 -0.40; T = 0.53 -2.50; P 〉 0.05 ）. The total detection time was about 1 h. [ Conclusion] The optimized real-time fluorescence quantitative RT-PCR system can be used for rapid detection of WSSV, IHHNV, TSV and YHV.

Detection and clinical significance of multidrug resistance-1 mRNA in bone marrow cells in children with acute lymphoblastic leukemia by real-time fluorescence quantitative RT-PCR

Objective： Multidrug resistance（MDR） is one of the most important reasons for treatment failure and recurrence of acute leukemia. Its manifestations are different in children with acute lymphoblastic leukemia（ALL） which may be due to different detection methods. This study was to detect the expression of MDR1 mRNA in bone marrow cells of children with ALL by real-time fluorescence- quantitative reverse transcription polymerase-chain reaction（FQ-RT-PCR）, and combine minimal residual desease（MRD） detection by flow cytometry（FCM） and to study their relationship with treatment response and prognosis of ALL. Methods：The MDR1 mRNA levels in bone marrow cells from 67 children with ALL[28 had newly diagnosed disease, 27 had achieved complete remission（CR）, 12 recurrent] and 22 children without leukemia were detected by FQ-RT-PCR. MRD was detected by FCM. The patients were observed for 9-101 months, with a median of 64 months. Results：Standard curves of human MDR1 and GAPDH genes were constructed successfully. MDR1 mRNA was detected in all children with a positive rate of 100%. The mRNA level of MDR1 was similar among the newly diagnosed ALL group, CR group, and control group（P 〉 0.05）, but significantly higher in the recurrence group than that in newly diagnosed disease group and control group（0.50 ± 0.55 vs. 0.09 ± 0.26 and 0.12 ± 0.23, P〈 0.05）. 54 ALL patients were followed up, and it was found that MDR1 mRNA level was significantly higher in ALL patients within 3 years duration than that of ALL patients with 3-6 years and over 6 years duration（0.63 ± 0.56 vs. 0.11 ± 0.12 and 0.04 ± 0.06, P〈 0.01）. For the 28 children with newly diagnosed disease, the MDR1 mRNA level was similar between WBC 〉 50 ~ 109 group and WBC〈50 × 10^9 group（P〉 0.05）. In the 33 CR patients, the MDR1 mRNA level was significantly higher in MRD〉10a group than that in MRD〈10a group（0.39 ± 0.47 vs. 0.03 ± 0.03, P 〈 0.05）. Conclusion：The sensitivity and specificity of FQ-RT-PCR in detecting MDR1 mRNA in bone marrowy cells of children with ALL patients are high. MDR1 mRNA is expressed in children with and without leukemia. MDR1 mRNA is highly expressed in the CR ALL patients with high MRD, recurrence and short duration（within 3 years）. Monitoring MRD and the MDR1 mRNA level might be helpful for individual treatment.

Development and Preliminary Application of SYBR Green I Real-Time Fluorescence Quantitative PCR Method for Detecting Porcine Parvovirus Virus

According to VP2 gene sequence of the porcine parvovirus virus strain NADL-2 （NC001718） available in GenBank （NC_001718）, a pair of specific primer was designed, and the target fragment of 431 bp was obtained by PCR amplification. The products were ligated with pMD18- T vector and then transformed into bacteria DH5α for recombinant plasmid extraction. After PCR identification and sequencing, recombinant plasmid was used as a standard template to establish the standard curve of SYBR Green I fluorescence quantitative PCR. Sensitivity test, specificity test and repeatability test were also determined. The results indicated that there was a good linear relationship between threshold cycle of the standard curve and template concentration, R2 =0.997 6. Tm ranged from 82.3 to 82.9 ℃, while the sensitivity was 72.1 copies/μl with good specificity and repeatability. The developed SYBR Green I real-time quantitative PCR method to detect PPV VP2 gene laid the basis for further studies on patho- oenesis, early clinical diaonosis of this virus and quantitative analysis of PPV infection.

鸽腺病毒通用型实时荧光PCR检测方法的建立与应用

鸽腺病毒(pigeon adenovirus,PiAdV)是影响鸽产业健康发展的重要病原之一。为实现PiAdV的高通量快速检测,根据GeneBank登录的PiAdV-A种和PiAdV-B种病毒pⅧ基因序列的共同保守区域设计特异性检测引物和探针,经反应条件优化,建立了一种PiAdV通用型实时荧光PCR检测方法,并对该方法进行了特异性、敏感性、重复性试验。结果显示:该方法的最佳探针浓度为0.2μmol/L,与鸽群其他常见病毒无交叉反应,对PiAdV的最低检测限为56.9 copies/μL,比常规PCR敏感性高100倍,组内和组间重复变异系数均小于1.8%。利用该方法和常规PCR方法对20份疑似PiAdV感染样品进行检测,发现PiAdV通用型实时荧光PCR检测方法的病毒阳性检出率高于常规PCR方法。结果表明,本研究建立的PiAdV通用型实时荧光PCR检测方法特异性强、敏感性高、可靠性好,可用于PiAdV感染的临床检测及流行病学调查。

水貂圆环病毒实时荧光定量PCR检测方法的建立与应用

为快速检测水貂圆环病毒(MiCV),本试验根据MiCV Cap基因序列设计合成特异性引物,建立了水貂圆环病毒SYBR Green II实时荧光定量PCR检测方法。结果显示,该方法在模板浓度为1.0×10^(6)~1.0×10^(1) copies/μL范围内呈良好线性关系,相关系数为0.9983。本试验建立的检测方法对水貂阿留申病毒、猪圆环病毒2型、水貂肠炎病毒、犬瘟热病毒和猪伪狂犬病毒进行检测均无特异性扩增,批内和批间CV均小于2%,对重组阳性质粒的检测下限为1.0×10^(1) copies/μL,比普通PCR的敏感度高100倍,对阳性样品DNA的检测下限为2.38×10^(-2) pg/μL,比普通PCR的敏感度高1000倍。应用该方法对吉林省部分毛皮动物养殖场的水貂、狐狸、貉和环境样品进行检测,结果其阳性率分别为57.23%、48.42%、39.71%和68.48%。上述结果表明,本研究建立的实时荧光定量PCR检测方法具有良好的灵敏性、特异性和重复性,为MiCV的诊断及流行病学调查提供技术支持。

美洲鳗鲡腺瘤病毒(AEAdoV)普通PCR和SYBR Green I实时荧光定量PCR检测方法的建立及应用

为建立美洲鳗鲡腺瘤病毒(AEAdoV)的检测方法,根据AEAdoV福建株(AEAdoVFJ)的superfamily 3 helicases(S3H)序列,设计引物,建立了AEAdoV的普通PCR和qPCR检测方法;进一步评价检测方法的灵敏性、特异性及重复性,利用2种方法对美洲鳗鲡“出血性烂鳃”病料进行了检测,并对美洲鳗鲡体内不同组织的病毒含量进行分析。结果显示,普通PCR扩增的目的片段长度约300 bp,利用其构建的qPCR质粒标准品,其拷贝数与qPCR阈值循环数(C_(t))线性关系良好,线性范围广,标准曲线相关系数(R2)达到0.999,扩增效率为105.067%。建立的普通PCR法和qPCR的最低检测AEAdoV拷贝数分别为100个和10个。2种方法均可特异性检测AEAdoV,而对蛙虹彩病毒(RGV)、鳗鲡疱疹病毒(AngHV)、鲤疱疹病毒(KHV)、对虾白斑综合征病毒(WSSV)、日本鳗鲡内皮细胞坏死病毒(JEAdoV)和花鳗鲡腺瘤病毒(MEAdoV)均无扩增反应。qPCR法的组内和组间变异系数均小于2%,表明其重复性良好。临床应用结果显示,35份美洲鳗鲡“出血性烂鳃”病料,采用普通PCR法的AEAdoV检出率为82.8%,而qPCR法的AEAdoV检出率为97%。对美洲鳗鲡不同组织的病毒含量分析结果显示,心脏、肝脏、鳃、鳍的AEAdoV相对含量较高,而黏液、皮肤和脾脏的病毒含量相对较低。研究表明,建立的AEAdoV的灵敏度高、特异性强的普通PCR和qPCR检测方法,证实AEAdoV与美洲鳗鲡“出血性烂鳃”病密切相关,且在感染鳗鲡主要组织中都存在。实验结果对于研究AEAdoV的致病性,开展其流行情况和病原学情况分析具有重要意义。

鸽微RNA病毒实时荧光定量RT-PCR检测方法的建立

旨在建立鸽微RNA病毒(pigeon megrivirus,PiMeV)实时荧光定量RT-PCR检测方法。本研究根据GenBank中PiMeVs序列特征设计特异性检测引物,从信鸽粪便中检测到PiMeV阳性(命名为PiMeV-CHN001株),并对其3 C基因进行核苷酸同源性比较和遗传进化分析,明确其基因特征后,设计特异性实时荧光定量RT-PCR检测(RT-qPCR)引物组,建立检测PiMeV的RT-qPCR方法。结果显示:PiMeV-CHN001株3 C基因全长为591 bp,编码197个氨基酸,和其他2株野鸽源PiMeV(MeV-B1株和MeV-B2株)核苷酸相似性分别为89.5%和92.0%。建立的检测PiMeV的RT-qPCR方法的标准曲线Y轴截距为37.93,斜率为-3.335,相关系数为1.00,扩增效率为99.4%。特异性强,仅PiMeV出现特异性扩增信号和特异性峰值[Tm值为(81.69±0.22)℃],对鸽源禽流感病毒(avian influenza virus,AIV)、鸽源禽I型副黏病毒(pigeon paramyxovirus type I,PPMV-1)、鸽输血传播病毒(pigeon torque teno virus,PTTV)、鸽腺病毒(pigeon adenovirus,PiAd)及鸽圆环病毒(pigeon circovirus,PiCV)检测均未见特异性扩增信号;敏感性优,最低检测限为54.0拷贝·μL^(-1);重复性好,批内和批间变异系数均低于1.5%。用建立的检测方法对42份信鸽粪便样品进行检测,发现2份阳性样品(阳性率为4.76%)。本研究首次证实我国大陆地区信鸽中存在PiMeV,丰富了PiMeV宿主谱信息;建立的RT-qPCR方法为后续开展PiMeV流行病学研究提供支撑。

猪肺炎支原体实时荧光定量PCR检测方法建立及应用

猪肺炎支原体(Mycoplasma hyopneumoniae)是一种严重危害养猪业的重要传染性病原,以猪肺炎支原体编码乳酸脱氢酶的P 36基因保守序列为基础,设计一套特异性引物和探针,并通过优化筛选反应条件,建立了一种Mhp的实时荧光定量RT-PCR检测方法。结果表明,最适引物浓度为10μmol/L,探针浓度为5μmol/L,以浓度为1×10^(2)~1×10^(6)copies/μL的标准品构建标准曲线相关系数为0.998,扩增效率可达96%。该方法能特异地检测猪肺炎支原体,与其他动物支原体及猪繁殖与呼吸综合征病毒、猪圆环病毒2型、猪瘟病毒、伪狂犬病病毒等病原无交叉反应;灵敏度是常规PCR的10倍,可达到10拷贝;该方法重复性较好,组内和组间变异系数均小于2%。在对30份临床样本的检测中,建立的实时荧光定量PCR检出率为63%(19/30),而常规PCR的检出率仅有30%(9/30)。结果表明,成功建立了猪肺炎支原体实时荧光定量PCR检测方法,可用于猪肺炎支原体的病原学检测和流行病学调查。

基于LNA-TaqMan探针实时荧光定量PCR检测技术的药用黄精掺伪研究

目的:建立一种快速、灵敏、有效的实时荧光定量聚合酶链式反应(PCR)方法,用于检测湖北黄精掺伪药用黄精。方法:基于锁核酸(LNA)-TaqMan探针实时荧光定量PCR技术,利用不同基原药用黄精样品的叶绿体DNA中trnC-petN基因序列差异,根据常见混伪品湖北黄精特异性差异位点设计筛选探针引物,并对引物及LNA-TaqMan探针的特异性进行验证。根据扩增曲线临界循环数(Ct)值的差值计算湖北黄精掺伪比例。结果:基于LNA-TaqMan探针能够特异性地检测出湖北黄精并确定掺伪比例,在湖北黄精掺伪1%时,仍可稳定检出。结论:该方法简便准确、稳定可靠,可以用于药用黄精掺伪湖北黄精定量检测。

牛呼吸道合胞体病毒一步法实时荧光定量PCR检测方法的建立及应用

为建立一种牛呼吸道合胞体病毒(Bovine respiratory syncytial virus, BRSV)快速简便的检测方法,本研究基于BRSV M基因保守区序列,设计特异性引物及探针,通过优化反应条件,建立用于BRSV检测的一步法实时荧光定量PCR,并验证了该方法的敏感性、特异性和重复性;同时利用建立的检测方法对采集的临床样本进行检测。结果表明:本研究所建立的BRSV荧光定量检测方法,其特异性好,仅对BRSV存在特异性扩增;敏感性高,最低可达10 copies/μL;稳定性好,组内变异系数和组间变异系数小。使用所建立的BRSV一步法实时荧光定量PCR对宁夏地区94份临床样品进行检测,阳性率为5.3%(5/94)。上述结果表明,本研究建立的检测方法可为BRSV的快速诊断提供有力的技术支持。

PRRSV、CSFV、PRV和PCV2四重实时荧光定量PCR检测方法的建立及应用

为建立同时检测猪繁殖与呼吸综合征病毒(PRRSV)、猪瘟病毒(CSFV)、猪伪狂犬病病毒(PRV)、猪圆环病毒2型(PCV2)的四重荧光定量PCR(qPCR)检测方法,针对PRRSV的ORF2基因、CSFV的5′UTR基因、PRV的gB基因、PCV2的ORF2基因设计了引物及Taq Man探针,并进行反应体系优化,敏感性、特异性验证,建立了同时检测上述4种病原的四重实时荧光定量PCR。结果显示,所建立的四重荧光PCR扩增效率(E)、相关系数(R^(2))及曲线斜率均在正常范围内,检测PRRSV、CSFV、PRV、PCV2 E值、R^(2)、斜率分别为92.9%、0.998、-3.504,90.7%、0.998、-3.566,94.3%、0.996、-3.466,94.2%、0.997及-3.470。PRRSV、CSFV、PRV、PCV2重组质粒最低检出限分别达到10^(2)、10^(2)、10^(2)、10^(3) copies/μL;四重qPCR反应体系中的多条引物间不发生交叉反应,经评价该方法特异性良好;批内和批间重复性试验结果显示,变异系数(CV)均在1%以下,具有良好的重复性。分别使用该方法和相应的国标荧光定量检测法对采集的298份临床样品进行检测对比,两种方法检测PRRSV、CSFV、PRV、PCV2阳性符合率分别为96.08%、96.38%、100%、94.95%,均在94%以上。结果表明,建立的检测方法方便、灵敏、高效、特异性强,适用于猪呼吸道疾病病原学、流行病学研究以及临床病例的诊断,并为猪呼吸道疾病的预防和控制提供技术支撑。

黄芪根腐病菌腐皮镰刀菌的实时荧光定量PCR检测方法建立

本研究成功建立了一种针对黄芪根腐病菌腐皮镰刀菌(Fusarium solani)的实时荧光定量PCR(RT-qPCR)检测方法。该方法基于腐皮镰刀菌翻译延伸因子EF-1α基因序列,设计了特异性引物对FP.F/FP.R,并验证其特异性。建立腐皮镰刀菌的RT-qPCR检测方法;运用所建方法检测黄芪及土壤中腐皮镰刀菌的含量,验证其检测效果。结果表明:设计的引物FP.F/FP.R特异性强,RT-qPCR检测的灵敏度为0.0192 ng/μL,重复性评价显示方法稳定、可靠。应用该RT-qPCR方法,可从黄芪接种发病和疑似发病样本及土壤样本中检测出腐皮镰刀菌。结果表明,3组样本的总阳性检出率均为100%。同时,植株和土壤中腐皮镰刀菌的含量变化与根腐病的严重度基本一致。因此,本研究建立的RT-qPCR方法能够有效地用于黄芪植株及土壤中腐皮镰刀菌的定量检测,为根腐病的早期诊断、预警和病原菌的动态监测提供了重要的技术支持。

禽源大肠杆菌荧光定量PCR方法的构建及应用

为建立一种灵敏、准确且快速检测禽源大肠杆菌的方法,根据禽源大肠杆菌uidA基因的一节特异性保守序列设计引物,建立用于禽源大肠杆菌的荧光定量PCR(qPCR)检验方法,并对其各方面进行评价。试验数据表明所建立的qPCR方法的Ct值与标准品在4.69×10^(2)~4.69×10^(9 )copies/μL范围内存在优良的线性关系,线性相关系数为R2=0.993;该方法标准曲线方程为y=-3.2786x+39.032,熔解曲线表现为单峰,不存在非特异性扩增。对重组质粒标准品的最低检测浓度为4.69×10^(2) copies/μL,是普通PCR方法的1000倍。该方法检测临床样本阳性率为68.3%(41/60),普通PCR阳性检出率为23.3%(14/60),阳性检出率高出45%。此次研究建立的检测禽源大肠杆菌的荧光定量PCR检测方法可用于禽源大肠杆菌的快速诊断,对于禽大肠杆菌病的监测具有重要意义。

Application of Real-time Fluorescent Quantitative PCR in Studies on Plants

Real-Lime fluorescent quantitative PCR is a method for quantitative analysis of gene expression developed in recent years, which has been widely used in various fields such as basic scientific research, clinical diagnosis, disease study, drug research and development since its appearance. It starts relatively late in study on plants, but has already been used for analysis of gene expression in plants and gene identification of exogenous genes. The principles or advantages and dis- advantages of real-time fluorescent quantitative PCR, or its potential problems and condition optimizations in tests were introduced in this study, and then the appli- cation and prospect of real-time fluorescent quantitative PCR in study on plants were also been discussed.

Detection of Lactobacillus acidophilus in Fermented Material by Real-time Fluorescent Quantitative PCR

The species distinctive PCR primer of Lactobacillus acidophilus （ L. acidophilus） was designed according to 16S rRNA gene sequences of conunon Lac- tobacillus species in fermented material. Bacterial genome DNA of separated L. acidophilus in fermented sample was taken as template, and L. acidophilus in fer- mented material was conducted the quantitative determination by real-time quantitative PCR （RT-PCR）. Analysis on RT-PCR results shown that contents of L. aci- dophilus in the test sample reached 1.5 billion CFU / g. Test results shown that contents of L. acidophilus in fermented material could be detected accurately by the established RT-PCR method in the test. indicating that the established RT-PCR method could be aookued to the detection of L. acidophilus in fermented material.

Real-time fluorescent quantitative immuno-PCR method for determination of fluoranthene in water samples with a molecular beacon

A reliable and sensitive competitive real-time fluorescent quantitative immuno-PCR （RTFQ-IPCR） assay using a molecular beacon was developed for the determination of trace fluoranthene （FL） in the environment.Under optimized assay conditions,FL can be determined in the concentration range from 1 fg/mL to 100 ng/mL,with y=0.194x ＋ 7.859,and a correlation coefficient of 0.967 was identified,with a detection limit of 0.6 fg/mL.Environmental water samples were successfully analyzed,recovery was between 90% and 116%,with intra-day relative standard deviation （RSD） of 6.7%-12.8% and inter-day RSD of 8.4%-15.2%.The results obtained from RTFQ-IPCR were confirmed by ELISA,showing good accuracy and suitability to analyze FL in field samples.As a highly sensitive method,the molecular beacon-based RTFQ-IPCR is acceptable and promising for providing reliable test results to make environmental decisions.

实时荧光定量PCR检测猴痘病毒的方法研究

目的建立猴痘病毒(mpox virus)的实时荧光定量PCR(RT-PCR)检测方法。方法以猴痘病毒F3L基因为靶序列,设计特异性引物和探针,建立猴痘病毒RT-PCR检测方法,并对方法的灵敏度、特异性和重复性进行检测;对疑似猴痘阳性的人脓拭子临床样本核酸进行检测,对RT-PCR方法检测临床样本能力进行评价。结果本研究建立的RT-PCR检测方法可实现猴痘病毒的特异性检测,与天花、痘苗、牛痘等其他正痘病毒无交叉反应,检测重复性好,最低检测限为103copies/μL。可以对人皮肤拭子样本中的猴痘病毒进行准确检测。结论本研究建立了猴痘病毒的RT-PCR检测方法,可在临床样本中快速、特异、灵敏的检测猴痘病毒。

Development of Real-Time Fluorescent PCR for Rapid Detection of Haempohlius parasuis

[ Objective] To develop a real-time fluorescent PCR assay for rapid detection of Haempohlius parasuis （HPS）. [ Method] According to the conservative sequences of 16 S rRNA genes of HPS published in GenBank, a pair of specific primers was designed. The real-time fluorescent PCR was developed by optimizing primer concentration and annealing temperature. And its specificity and reproducibility were evaluated. Ten HPS- suspected samples were detected by the developed method. [ Result] The lowest detection limit of the developed real-time fluorescent PCR was 50 copies/μl. This method had good reproducibility, and its coefficient of variation was lower than 2%. Only HPS rather than Streptococcus suis type 2, Staphylococcus aureus, E. coli DH5 alpha, and swine Salmonella typhi could be detected by the developed real-time fluorescent PCR. The HPS-pesitive samples detected by this method were also positive when they were detected by isolation of bacteria or conventional PCR. [ Conclusion] The developed real-time fluorescent PCR is rapid, sensitive, specific and highly reproducible; thus, it can be used for rapid detection of HPS.