副溶血弧菌实时荧光定量PCR快速检测方法的建立

为建立检测副溶血弧菌(Vibrio parahaemolyticus,VP)的快速检测方法,本研究以VP toxR基因为靶基因设计合成引物及TaqMan探针,建立了实时荧光定量PCR快速检测VP的方法。结果显示,对15株试验菌株进行实时荧光定量PCR检测,只有VP检测为阳性,表明该检测方法特异性强;该方法的灵敏度为4.9 CFU/mL,利用该检测方法对采集的150份样品进行检测,共计检出3份VP阳性样品,与国标法(GB 4789.7-2013)检测结果一致,显示了良好的实用性。该检测方法灵敏度高、特异性强,具有良好的实用性。     

犬细环病毒SYBR GreenⅠ荧光定量PCR检测方法的建立

为建立犬细环病毒(TTCV)的快速检测方法,本研究根据GenBank中登录的TTCV ORF7基因设计合成一对特异性引物,并对反应条件和反应体系进行优化,建立了检测TTCV的SYBR Green I荧光定量PCR方法。结果显示:建立的荧光定量PCR方法 Ct值与标准品模板在5.82×10~9拷贝/μL~5.82×10~3拷贝/μL范围内呈良好的线性关系。该检测方法仅对TTCV检测为阳性,而对狂犬病病毒、犬冠状病毒、犬细小病毒、犬瘟热病毒和犬副流感病毒均无特异扩增;该检测方法灵敏度可达5.82×103拷贝/μL。对27份犬血清样品检测结果显示,建立的荧光定量PCR阳性检测率为11.11%,而普通PCR方法检测阳性率为3.7%。本实验建立了TTCV SYBR Green Ⅰ荧光定量PCR检测方法,对TTCV诊断及致病机制的研究提供了高通量的定量检测方法。     

犬腺病毒和犬细小病毒双重TaqMan荧光定量PCR检测方法的建立

为建立犬腺病毒(CAV)和犬细小病毒(CPV)双重荧光定量PCR检测方法,本研究根据GenBank中已登录的CAV Hexon基因序列和CPV VP2基因序列,设计了2对特异性引物和2条Taq Man探针。经过条件优化建立了检测CAV和CPV的双重TaqMan荧光定量PCR检测方法。结果显示,以含有CAV Hexon基因和CPV VP2基因的重组质粒标准品为模板绘制标准曲线,其相关系数(R~2)均大于0.990,CAV和CPV荧光定量PCR均具有良好的线性关系。特异性试验结果显示,该方法仅对CAV-I型、CAV-II型和CPV检测结果为阳性,而对犬瘟热病毒、犬副流感病毒和犬冠状病毒检测结果均为阴性,表明其特异性强。该方法的敏感性检测结果显示其检测下限为10拷贝/μL。重复性试验结果显示该方法的组内和组间变异系数均小于2%,表明该方法重复性好。利用普通PCR方法与本实验建立的方法分别对感染CAV(10份)和CPV(27份)的犬模拟病料样品进行检测,两种方法对CAV和CPV检测的符合率分别可达100%和96.30%。本研究建立的荧光定量PCR检测方法具有快速、敏感、准确等优点,可以用于CAV和CPV的临床检测。     

牛传染性鼻气管炎病毒TaqMan-MGB荧光定量PCR方法的建立

为建立牛传染性鼻气管炎病毒(IBRV)的TaqMan荧光定量PCR检测方法,本研究根据IBRVgB基因保守区域设计特异性引物和MGB探针,并采用矩阵法优化了PCR反应条件。结果显示,标准曲线相关系数(R2)为0.998,103拷贝/μL~108拷贝/μL内具有较好的线性关系。对牛呼吸道合胞体、牛病毒性腹泻粘膜病1型、牛副流感病毒3型的cDNA进行检测,结果均为阴性,特异性良好。该方法对IBRV检测的灵敏度可达到1.49×101拷贝/μL,是常规PCR灵敏度的100倍,重复性试验表明该方法的组内和组间变异系数均小于1.5%。应用建立的方法与普通PCR方法分别对17份疑似临床呼吸道症状牛鼻黏液拭子样品进行检测,该方法检测的阳性率比传统PCR法检测的阳性率提高了约12%。研究表明建立的IBRV TaqMan-MGB荧光定量PCR方法灵敏、快速、特异性强、重复性好,适用于临床疑似样品的快速定量检测。     

环形泰勒虫SYBR Green I荧光定量PCR方法的建立及应用

为建立一种快速、敏感检测牛环形泰勒虫的方法,本研究根据GenBank中登录的牛环形泰勒虫Tams1基因序列,设计合成1对特异性引物,通过优化反应条件,建立了检测牛环形泰勒虫SYBR Green I荧光定量PCR检测方法。研究结果显示,该方法可以特异地检测牛环形泰勒虫,而对牛巴贝斯虫、反刍动物艾立希体和弓形虫检测均为阴性;该方法的灵敏度可达到180拷贝/μL,比常规PCR敏感10倍;组内和组间变异系数均小于1.0%。对15份临床血液样品和20只璃眼蜱进行检测,SYBR Green I荧光定量PCR和常规PCR的阳性检出率分别为42.86%和28.57%。本研究建立的SYBR Green I荧光定量PCR检测方法具有特异性强、敏感性高的特点,可准确、高效检测牛环形泰勒虫,为牛环形泰勒虫病防控提供技术支持。     

鸡Caspase-1基因SYBR Green Ⅰ荧光定量PCR检测方法的建立

为了建立快速定量检测鸡Caspase-1基因的方法,本研究根据鸡Caspase-1基因序列设计特异性检测引物,PCR扩增Caspase-1基因片段,构建pMD-Caspase-1重组质粒。以该重组质粒为标准品进行荧光定量PCR扩增,建立标准曲线,并通过反应条件优化、特异性、敏感性及重复性等试验,建立了鸡Caspase-1基因SYBR Green I荧光定量PCR检测方法。结果显示,本研究建立的该荧光定量PCR方法在重组质粒标准品为1.0×10~3拷贝/μL～1.0×10~8拷贝/μL范围内具有良好的线性关系;该荧光定量PCR方法对Caspase-1基因的扩增具有较强的特异性;对重组质粒标准品的检测下限为1.0×10~2拷贝/μL,比常规PCR敏感100倍;批内和批间变异系数分别在0.51%～4.41%和0.37%～0.88%,重复性好。利用所建立的方法可以定量检测致病性禽腺病毒血清4型感染鸡不同组织中Caspase-1的转录水平。本研究方法的建立将为研究鸡Caspase-1在免疫反应和疫病发展过程中的作用提供技术支持。     

单核细胞增生李斯特氏菌实时荧光定量PCR快速检测方法的建立

为建立单核细胞增生李斯特菌(Listeria monocytogenes,LM)的快速检测方法,本研究以LM iap基因为靶基因设计合成引物及TaqMan探针,建立实时荧光定量PCR快速检测LM的方法。结果显示,对15株试验菌株进行实时荧光定量PCR检测,只有LM菌株检测为阳性,表明该检测方法特异性强;该方法的灵敏度为6.5 CFU/mL;稳定性和重复性试验结果表明,同一样品重复检测4次Ct值的变异系数均小于2%;利用该检测方法对采集的139份样品进行检测,共计检出3份LM阳性样品,与国标法(GB 478930-2010)检测结果一致。该检测方法灵敏度高、特异性强、重复性好,具有良好的实用性。     

TaqMan荧光定量PCR在饲料沙门氏菌检测中的应用评估

为评估Taq Man荧光定量PCR应用于饲料沙门氏菌检测的可行性,本研究以沙门氏菌JEO402-1基因为靶基因,并采用已建立的沙门氏菌Taq Man荧光定量PCR检测方法,进行了特异性、灵敏度、检测限等相关方法学验证。结果显示:Taq Man荧光定量PCR法特异性良好,在饲料加标样本检测中的最低检测限为2×10~(-1)cfu/m L。重复性试验表明,在不同浓度样本中的变异系数均低于1.0%,具有较高的重复性和稳定性。利用该方法和传统培养法对72份饲料样本进行检测,结果显示两种方法检测结果符合率为65.3%,Taq Man荧光定量PCR法阳性检出率比传统培养法高34.7%;传统培养法检测阳性样本,PCR法检测结果均为阳性。以上结果表明,本研究建立的Taq Man荧光定量PCR法可以应用于饲料样本的沙门氏菌检测。     

犬瘟热病毒、犬细小病毒二重TaqMan MGB探针实时荧光定量PCR检测方法的建立与应用

为建立一种特异、高通量检测犬瘟热病毒(canine distemper virus,CDV)和犬细小病毒(canine parvovirus,CPV)的二重TaqMan MGB探针实时荧光定量PCR方法,本研究选取高度保守且具有型特异性的CDV H基因和CPVVP2基因序列,设计CDV和CPV特异性引物对及TaqMan MGB探针;经反应条件优化,建立了检测CDV和CPV的二重TaqMan MGB探针实时荧光定量PCR方法,并进行了敏感性、特异性和重复性试验。结果显示,该方法检测CDV、CPV的标准曲线线性相关系数(R~2)分别为0.997和0.993,最低检出限均为10拷贝/μL,具有较高的灵敏性;对犬副流感病毒等4种病原对照和阴性对照均未出现扩增,特异性良好;CDV、CPV标准品批间试验结果显示,该方法具有很好的重复性;对48份临床疑似CDV或CPV感染样品检测结果显示,14份为CDV阳性,19份为CPV阳性,4份为CDV/CPV双阳性,与CDV H基因、CPVVP2基因测序结果符合率为100%。本研究建立的二重TaqMan MGB探针实时荧光定量PCR方法具有灵敏、特异、高通量和可准确定量等优点,可用于临床CDV/CPV病毒感染各个时期的快速鉴别检测。     

猪圆环病毒3型实时荧光定量PCR检测方法的建立及应用

为建立快速、灵敏且特异的检测猪圆环病毒3型(porcine circovirus, PCV)的实时荧光定量PCR方法,本研究根据ORF2基因的保守序列设计一对特异性引物和TaqMan探针,通过构建标准品质粒来制作荧光定量PCR标准曲线,优化反应条件,验证敏感性、特异性及重复性,建立了检测PCV3的实时荧光定量PCR方法。结果显示,该方法可以特异性检测出PCV3,而对猪圆环病毒2型、猪瘟病毒、猪繁殖与呼吸综合征病毒、猪流行性腹泻病毒、猪细小病毒、伪狂犬病毒等检测结果均为阴性,表明其具有良好的特异性。用构建的标准品质粒测得的灵敏度可以达到10 copies/μL,重复试验批内及批间变异系数均小于2%,表明其具有良好的灵敏性和重复性。以上结果表明,本研究建立的TaqMan荧光定量PCR检测方法具有快速、灵敏性高、特异性强的优点,可为我国PCV3型的早期检测及相关研究工作提供可靠的技术支持。     

化脓隐秘杆菌TaqMan实时荧光定量PCR检测方法的建立

本试验旨在建立检测化脓隐秘杆菌(Arcanobacterium pyogenes,A.pyogenes)特异、灵敏的TaqMan实时荧光定量PCR检测方法。根据GenBank公布的化脓隐秘杆菌溶血素(pyolysin,PLO)基因高保守序列,设计特异性引物和探针建立检测体系,用于化脓隐秘杆菌的快速检测,并对该方法的特异性和灵敏度进行检测。结果显示,本试验建立的TaqMan实时荧光定量PCR方法仅对化脓隐秘杆菌的检测结果为阳性;该方法最低检测DNA浓度为77.6 fg,最低检测细菌浓度为63 CFU/mL。采用本研究建立的方法检测23份林麝临床病例样品,共鉴定出16株化脓隐秘杆菌,与API Coryne生化鉴定方法的结果相同。本研究为化脓隐秘杆菌的检测提供了一种灵敏、特异、快速的检测方法,其可用于化脓隐秘杆菌的诊断和流行病学调查。     

Establishment of TaqMan Real-time PCR Assay for Detection of Arcanobacterium pyogenes

The study was aimed to establish a specific and sensitive TaqMan Real-time PCR assay for detection of Arcanobacterium pyogenes (A.pyogenes).Based on the conservative sequence of pyolysin (PLO) gene of A.pyogenes published in GenBank, specific primers and TaqMan probes were designed. The TaqMan Real-time PCR assay was established, and the specificity and sensitivity were tested.The specificity test results showed that only A.pyogenes exhibited typical curves.The detection sensitivity of this assay was 77.6 fg genomic DNA per 20 μL reaction, and 63 CFU/mL for pure cultures.16 out of 23 clinical samples were positive detected by the TaqMan Real-time PCR assay, which were consistent with API Coryne identification.The TaqMan Real-time PCR assay developed in this study was specific and sensitive for detection of A.pyogenes, and it could be used for identification and epidemiological investigation of A.pyogenes.     

反刍动物埃立克体荧光定量PCR检测技术的建立和应用

为快速、准确地检测反刍动物埃立克体,本研究以反刍动物埃立克体pCS20为靶基因设计特异性引物和探针,建立了TaqMan和Eva Green荧光定量PCR方法,对其反应的特异性、敏感性和重复性进行了分析,并与OIE推荐的套式PCR方法一起对临床样品进行检测。结果显示,本方法特异性强,与牛巴贝斯虫、牛双芽巴贝斯虫、环形泰勒虫、犬埃立克体、牛埃立克体、马埃立克体和立氏埃立克体无交叉反应;TaqMan和Eva Green荧光定量PCR对pCS20质粒标准品的最低检测限分别为17.4拷贝·μL^-1和1.74拷贝·μL^-1,标准曲线相关系数大于0.99,组内和组间CV均小于1.5%。对420只钝眼蜱样本的检测显示,TaqMan和Eva Green荧光定量PCR的检出率分别为25.48%和29.29%,与套式PCR检测方法相比,敏感性更高。本研究为反刍动物埃立克体的检测和流行病学调查提供了一种快速、准确的检测方法。     

Development of a TaqMan PCR assay for the detection of Trypanosoma evansi, the agent of surra

A TaqMan PCR assay was developed for the detection of Trypanosoma evansi. The assay targets the internal transcribed spacer 1 (ITS-1) region of rRNA. The ITS-1 region of eleven strains of T. evansi from widely separated geographical regions were sequenced and alignments compared. Primers and probe for the test were designed from these sequence data. The assay was tested using blood from infected rats and was found to be sensitive, detecting less than one genomic equivalent of T. evansi. The assay has been tested against 10 different species of trypanosomes found in native animals in Australia and did not detect any of these trypanosome species. Time course experiments using rats infected with T. evansi were performed to compare the TaqMan assay with the Haematocrit centrifugation test (HCT) and the mouse inoculation (MI) assay. The assay was more sensitive than the HCT but not as sensitive as the MI. The TaqMan assay has the ability to rapidly detect T. evansi and determine the number of organisms present in a blood sample from an infected animal. This is the first time a TaqMan assay has been developed for the detection of T. evansi.     

Establishment and Application of TaqMan MGB Fluorescent-Quantitative PCR Assay for Detection of Canine Parvovirus

In order to establish a TaqMan MGB fluorescent-quantitative PCR (FQ-PCR) assay for detecting canine parvovirus (CPV) specifically, sensitively and rapidly, a highly sensitive and specific TaqMan MGB FQ-PCR assay was developed using the specific primers and TaqMan MGB probe designed basing on the conservative sequences of VP2 gene of CPV in GenBank. The sensitivity, specificity and repetition assay of FQ-PCR assay were tested, and 46 clinic suspicious CPV infected samples were detected by the FQ-PCR assay in contrast to the routine PCR method. The results indicated that the FQ-PCR was successfully established. The developed FQ-PCR assay was able to detect as little as 1×10¹copies/μL of recombinant pGEX-T/CPV plasmid DNA, and the sensitivity of which was 100 times more than that of the routine PCR. The specificity assay exhibited that positive signals could be obtained from recombinant pGEM-T/CPV plasmid, but not from the genomic DNA or total cDNA of the other 5 kinds of pathogenic microorganism acting as the controls. The repetition tests were carried out by detection repeated 3 times for 3 different concentrations of recombinant pGEX-T/CPV plasmid, and the results indicated that the FQ-PCR was reproducible. Twenty-three positive results from 46 clinic suspicious CPV infected samples were obtained, which showed the better sensitivity than that of the routine PCR, with 19 positive samples from the same 46 suspected samples. The study suggested that the CPV FQ-PCR method was successfully established, and suitable for clinic rapid diagnosing of CPV and early detection of latent infection.     

应用TaqMan荧光定量PCR检测牛分枝杆菌

为建立快速检测牛分枝杆菌(M.bovis)的TaqMan荧光定量PCR方法,本研究以GenBank登录的M.bovis特有229 bp基因为研究对象,设计并合成引物及探针。该方法具有较好的特异性,与标准质控菌株呈阳性反应,与其他微生物样品呈阴性反应;灵敏性最低检测值可达1 pg/mL;对20阳性临床样品进行荧光定量PCR检测,均为阳性;而对培养为阴性的20份临床样品进行检测,6份为阳性。该研究结果表明,建立的方法特异性强,敏感性高,稳定性好,能够用于M.bovis的鉴别检测,对牛分枝杆菌病的快速检测和早期诊断具有重要意义。     

Establishment and Application of A Double TaqMan MGB Real-time PCR Assay for Detection of Canine Distemper Virus and Canine Parvovirus

This study was aimed to establish a double TaqMan MGB Real-time PCR assay to simultaneously and specifically detect canine distemper virus (CDV) and canine parvovirus (CPV) in one reaction.Two pairs of specific primers for CDV and CPV,along with two TaqMan MGB probes for each virus were designed in the assay basing on CDV H gene and CPV VP2 gene sequences.The specificity,sensitivity and repetition of the double TaqMan MGB Real-time PCR assay were tested,and 48 samples taken from clinic suspicious CDV and CPV infected canines had been testified by the established double TaqMan MGB Real-time PCR.The results indicated that the doulde TaqMan MGB Real-time PCR assay was successfully established,and the number of standard curve correlation (R²) of CDV and CPV were 0.997 and 0.993,respectively.The specificity of the double TaqMan MGB Real-time PCR assay revealed that amplifications were showed on CDV and CPV samples,but other pathogens and negative controls had no amplifications;The sensitivity of CDV and CPV were both 10 copies/μL.Meanwhile,14 CDV positive samples,19 CPV positive samples and 4 CDV/CPV double positive samples were detected,which were consistent with the results of the sequencing.Therefore,the established double TaqMan MGB Real-time PCR assay had high sensitivity,specificity and flux accurate quantitative,which could be applied to clinical CDV/CPV infection each periods.     

Real-time polymerase chain reaction testing for the detection of Mycobacterium genavense and Mycobacterium avium complex species in avian samples

Diagnosis of avian mycobacteriosis, caused by Mycobacterium genavense or species belonging to the Mycobacterium avium complex (MAC), is problematic. Polymerase chain reaction (PCR) offers rapid and sensitive detection of minute quantities of DNA, and conventional protocols have been used for evaluating avian specimens. The recent development of real-time PCR offers several advantages over conventional PCR. In attempts to improve diagnosing avian mycobacteriosis, a real-time TaqMan PCR assay was developed targeting the 65-kD heat shock protein gene of M. genavense and MAC spp. Nineteen reference isolates, 16 clinical isolates, and 32 avian tissue samples were used to evaluate the assay. When sufficient amplicons were produced, the species of mycobacteria was determined by standard sequencing of TaqMan PCR products and compared with results from commercial mycobacteriology laboratories and/or standard sequencing of conventional PCR products. The TaqMan PCR detected DNA from reference isolates of M. genavense, MAC spp., and Mycobacterium tuberculosis complex spp. Of the clinical isolates, the TaqMan PCR detected DNA from 10 of 12 Mycobacterium avium avium isolates and two of three Mycobacterium avium intracellulare isolates. For the tissue samples, the TaqMan PCR amplified DNA in six of nine samples that were identified by sequencing of conventional PCR products and/or by commercial mycobacteriology laboratories as being MAC spp. positive and three of four samples that were positive for M. genavense. There was some disagreement between speciation results from the TaqMan PCR and those from commercial mycobacteriology laboratories or conventional PCR or both. This disagreement was suspected to be because of relatively small numbers of base pairs in the TaqMan PCR products. The TaqMan PCR may provide a useful tool for evaluating clinical samples for DNA from mycobacteria species that most commonly infect birds; however, further refinement is needed in order to improve sensitivity and provide more accurate speciation.     

牛轮状病毒TaqMan实时荧光RT-PCR 快速检测方法的建立

本研究按照牛轮状病毒(BRV)结构蛋白VP6基因序列,设计合成引物和探针,经各反应条件的优化,建立了BRV TaqMan实时荧光定量RT-PCR技术。对BRV进行了特异性、敏感性和重复性试验。结果表明,TaqMan实时荧光RT-PCR最低可检测到100个拷贝病毒RNA;与牛病毒性腹泻病毒(BVD)、猪瘟病毒(CSFV)、牛结核杆菌(MB)和牛传染性鼻气管炎病毒(IBRV)不发生交叉反应;所制作的标准曲线在10²~10⁹拷贝/μL浓度范围内有极好的线性关系且线性范围宽,相关系数为0.997;与常规的RT-PCR相比,该方法具有快速、特异、敏感、重复性好、可同时检测大量样品等优点。可对样品中微量BRV进行准确检测,对BRV的诊断有重要意义。