实时荧光PCR方法检测禽病毒病的研究

通用探针是实时荧光PCR探针类的一种,具有高度的特异性和灵敏度,可对样品进行准确的定量分析。本试验主要采用该方法对通用探针检测禽病毒病进行了研究,试验结果显示本方法的特异性、灵敏度和Taq Man探针相近,且具有操作简便、费用低廉等优点。     

猪细环病毒数字PCR定量检测方法的建立

[目的]实现猪细环病毒(TTSuV)的准确定量检测。[方法 ]根据TTSuV的序列特点,设计特异性引物、探针,建立数字PCR检测技术。对数字PCR反应体系中的引物和探针浓度进行优化,分析方法的灵敏度、特异性,并初步应用于进行临床检测。[结果 ]最终确定TTSuV1a和TTSuV1b数字PCR反应体系中最佳引物浓度均为250 nmol/L,最佳探针浓度均为300 nmol/L,TTSuV1a型和TTSuV1b型灵敏度均可达到单个拷贝数;以猪圆环病毒Ⅱ型、猪细小病毒和猪伪狂犬病毒进行特异性试验,结果无交叉反应;批内和批间试验表明,该方法的重复性良好;本实验室留存的92份血清样本的检测结果与其背景信息一致。[结论 ]本研究建立的TTSuV数字PCR法具有特异性强、灵敏度高、检测限低等优点,可用于TTSuV的定量检测。     

狂犬病病毒微滴式数字PCR检测方法的建立

为了建立可绝对定量狂犬病病毒(RABV)的微滴式数字PCR(ddPCR)检测方法,本试验根据RABV基因组起始区域设计引物和探针,继而优化引物和探针浓度以及退火温度,并对建立的ddPCR方法的灵敏度、特异性和重复性进行分析。结果显示：ddPCR方法的最佳引物和探针浓度分别为900 nmol/L和250 nmol/L,最佳退火温度为55℃;ddPCR方法的标准曲线相关系数(R²)为0.999,呈现良好的线性关系;灵敏度高,最低可检测到3.37 copies/μL;特异性良好,与常见犬病原无交叉反应;重复性好,检测结果稳定。临床样品的检测结果显示,本试验建立的狂犬病病毒ddPCR方法与实时荧光定量反转录PCR(RT-PCR)方法的符合率为100%。结果表明,本试验建立的狂犬病病毒微滴式数字PCR方法灵敏度高、特异性强,可用于狂犬病病毒的绝对定量检测。     

Taqman荧光PCR法检测肉制品中牛源性成分及定量研究

本研究通过以牛线粒体保守基因序列设计的特异性引物和探针,建立了肉制品中牛源性成分Taqman荧光PCR检测方法,并对方法的特异性、灵敏度和稳定性进行了评价;通过模拟浓度标准曲线,完成了对牛源性成分的相对定量检测。结果显示,本方法具有特异性强、灵敏度高(检出限为0.001%)的特点,适用于肉制品中牛源性成分及含量的快速检测。     

基于实时荧光PCR法定量检测食品中鸡源性成分

肉类食品真伪鉴定是目前食品安全检测领域的重点研究内容之一。为准确定量检测食品中的鸡源性成分,根据现行检验检疫标准(SN/T 2727—2010)合成引物及探针,并拓展了特异性、灵敏度、检出限和定量分析等试验。结果显示:特异性试验中,仅鸡成分检测出现特异性扩增,其他动物组织均未出现特异性扩增;梯度稀释鸡源性DNA模板原液进行灵敏度评价,发现引物和探针灵敏度较高,可以检测到100 fg级的鸡组分模板DNA,且建立的标准曲线具有良好的线性关系,R2达0.99以上,定量准确;加工制品中的验证试验结果显示,合成的引物及探针具有良好的适用性和定量检测能力。以上研究结果均说明,此引物和探针适用于市场食品中鸡源性成分的定性、定量检测。本研究为今后TaqMan实时荧光PCR法不同动物源性引物和探针的自主研发奠定了基础。     

猪瘟病毒荧光定量RT-PCR检测方法的建立

本研究在CSFV 5'端非编码区设计一对引物和一条特异性TaqMan探针,以构建的重组质粒为标准品,建立了一种检测CSFV的荧光定量PCR方法(FQ-PCR),对该方法进行特异性、敏感性和重复性试验.结果显示,可特异地检测CSFV,该方法在101～107拷贝/μL范围内具有良好的线性关系,灵敏度可达10拷贝/μL,重复...     

犬腺病毒I型和II型TaqMan双重荧光定量PCR方法的建立

为鉴别检测犬腺病毒（CAV）I型和II型,根据GenBank中CAV-I和CAV-II型参考基因序列,设计合成1对通用引物和2条鉴别探针,建立了可鉴别检测CAV-I型和CAV-II型的双重荧光定量PCR检测方法。同时,对该方法进行了优化,并对该方法的特异性、敏感性和重复性进行了试验,并与普通PCR检测方法进行样品检测符合率分析。特异性试验结果显示;本研究建立方法对犬瘟热病毒、犬副流感病毒、犬冠状病毒均未产生扩增曲线。敏感性试验结果显示,建立方法对CAV-I的检测敏感度为100 copies/μL,对CAV-II的检测敏感度为10 copies/μL。重复性试验结果显示,组内和组间变异系数均小于5%。临床样品检测对比结果显示,建立方法与普通PCR方法的符合率为95.12%。结果表明,本研究建立的TaqMan双重荧光定量PCR方法具有特异性好、灵敏度高、重复性好等优点,可用于临床鉴别检测CAV-I和CAV-II型。本研究为CAV-I和CAV-II型感染的检测、鉴别以及流行病学调查提供了便捷快速的方法。     

犬腺病毒Ⅰ型和Ⅱ型Taq Man双重荧光定量PCR方法的建立

为鉴别检测犬腺病毒(CAV)Ⅰ型和Ⅱ型,根据GenBank中CAV-Ⅰ和CAV-Ⅱ型参考基因序列,设计合成1对通用引物和2条鉴别探针,建立了可鉴别检测CAV-Ⅰ型和CAV-Ⅱ型的双重荧光定量PCR检测方法。同时,对该方法进行了优化,并对该方法的特异性、敏感性和重复性进行了试验,并与普通PCR检测方法进行样品检测符合率分析。特异性试验结果显示;本研究建立方法对犬瘟热病毒、犬副流感病毒、犬冠状病毒均未产生扩增曲线。敏感性试验结果显示,建立方法对CAV-Ⅰ的检测敏感度为100 copies/μL,对CAV-Ⅱ的检测敏感度为10 copies/μL。重复性试验结果显示,组内和组间变异系数均小于5%。临床样品检测对比结果显示,建立方法与普通PCR方法的符合率为95.12%。结果表明,本研究建立的Taq Man双重荧光定量PCR方法具有特异性好、灵敏度高、重复性好等优点,可用于临床鉴别检测CAV-Ⅰ和CAV-Ⅱ型。本研究为CAV-Ⅰ和CAV-Ⅱ型感染的检测、鉴别以及流行病学调查提供了便捷快速的方法。     

裂谷热病毒两种PCR检测方法的建立及比较分析

裂谷热(RVF)具有较高的发病率与死亡率,极大危害着当地养殖业和生态系统的稳定。为建立一种能够快速有效检测裂谷热病毒(RVFV)的方法,本研究根据RVFV的保守序列设计了特异性引物与探针,分别建立了探针PCR和荧光PCR,并对这两种检测方法进行比较分析。结果显示,两种检测方法均不存在非特异扩增;最低检测浓度分别为1.03×10~(-2)拷贝/μL和1.03×10~0拷贝/μL,前者比后者有更高的灵敏度;探针PCR和荧光PCR组内和组间变异系数均小于3%。实验表明,探针PCR具有特异性强、灵敏度高、稳定性好、准确度高、检测速度快等优点。因此,探针PCR是一种灵敏度和可靠性均较高的RVFV检测方法。     

应用多重实时荧光PCR方法对8种动物毛纤维种类鉴别的研究

本研究旨在利用多重实时荧光PCR方法对水貂、狐狸、骆驼、兔、山羊、绵羊、鸭和鹅8种动物毛纤维进行物种鉴定研究。利用碱裂解法加入二硫苏糖醇,并结合硅珠吸附核酸法来优化动物毛纤维DNA的提取;根据8种动物16S rDNA基因特异核苷酸序列设计通用PCR引物和特异性TaqMan荧光探针;通过优化引物和探针浓度及退火温度等PCR反应体系和条件,建立了多重实时荧光PCR检测体系;并对多重PCR体系的特异性、灵敏度、重复性和适用性进行评估。结果表明,使用SDS-二硫苏糖醇DTT-蛋白酶K结合Chelex-100法,并利用硅珠纯化提取动物毛纤维DNA效果最佳,满足实时荧光PCR检测要求。本方法 DNA灵敏度为0.01ng,混合样本方法检出限为1.0%。因此本方法能够从动物毛纤维提取高质量DNA,建立的多重实时荧光PCR检测体系具有特异性强、重复性好和灵敏度高等优势。本方法可用于水貂、狐狸、骆驼、兔、山羊、绵羊、鸭和鹅8种动物及其混合物毛纤维的鉴定,为拓展动物毛纤维在物种识别、分子进化研究、分子标记辅助育种和遗传资源评价等领域中的应用奠定基础。     

化学修饰法制备B组轮状病毒生物素核酸探针及应用研究

用亚硫酸氢钠—乙二胺溶液对B组轮状病毒的ssRNA胞嘧啶修饰和转氨基作用，与生物素e—氨基己酸N—羟基琥珀酰亚胺酯反应，制备探针与样品在硝酸纤维膜上进行点杂交，经亲合素—碱性磷酸酶系统显色，可测出106.25－212.5pg的RNA靶序列，特异性试验表明：B组生物素探针只能与B组核酸杂交，而与无关核酸无杂交信号，用B组探针检测45份仔猪腹泻粪样，检出B组阳性5份，检出率11．1％，明显高于PAGE法，实验结果表明，生物素核酸探针制备简单并且有特异、灵敏、稳定的优点，可用于各组轮状病毒的检测。     

Comparison of two enzyme-linked immunosorbent assays for diagnosis of Mycobacterium avium subsp. paratuberculosis.

Enzyme-linked immunosorbent assays (ELISAs) are used in Johne's disease (JD) control programs as a first screening for presence of the disease in a herd. A high sensitivity of the ELISA is therefore important, yet the commonly used ELISAs have relatively low sensitivity. The inclusion of an absorption phase, although improving specificity, potentially decreases sensitivity. Sera and feces of 383 adult dairy cows in 8 herds were used to compare the test characteristics of an absorbed and a nonabsorbed indirect ELISA for the detection of JD. The absorbed ELISA is based on a protoplasmic antigen, whereas the nonabsorbed uses a lipoarabinomannan-based antigen. The potential advantage of the nonabsorbed ELISA is that it may be less specific and more sensitive. Two herds certified free of JD were used to compare the specificity of the ELISAs. The other herds used to compare sensitivity were either infected with Mycobacterium avium subsp. paratuberculosis or had unknown status. Using fecal culture as a gold standard, the diagnostic specificity for the absorbed and nonabsorbed ELISAs were 98.4% and 87.9%, respectively. The diagnostic sensitivity was 72.4% and 65.5% for the absorbed and the nonabsorbed ELISA, respectively. Furthermore, a comparison using a fecal DNA probe as the comparison standard resulted in both ELISAs having a sensitivity of 61.9%. Agreement between the 2 ELISAs was moderate, with a kappa statistic of 0.58. The nonabsorbed ELISA did not have a higher sensitivity and had a lower specificity than the absorbed ELISA. Therefore, in this population, there was no advantage gained with using the nonabsorbed ELISA.     

Comparison of DNA probe test and cultivation methods for detection of Mycobacterium avium subsp paratuberculosis in caprine and ovine faeces

OBJECTIVE: To compare a DNA probe test with two cultivation methods for the detection of Mycobacterium avium subsp paratuberculosis in goat and sheep faeces. DESIGN: Comparison of the results of the three methods with histological examination as the reference standard. PROCEDURE: Faecal specimens were obtained from goats and sheep originating from flocks known to be affected with paratuberculosis and tested for Mycobacterium avium subsp paratuberculosis with a DNA probe test and two cultivation methods (old conventional culture and new double incubation method in Herrold's and Lowenstein-Jensen medium). RESULTS: In goats, the sensitivity of the various tests were for the DNA probe test 17.2%, for the double incubation culture method 25.4% and for the old conventional culture method 22.8% using the histopathological results as reference. In sheep the sensitivity of the various tests were for the DNA probe test 13.2%, for the double incubation culture method 8.8% and for the old conventional culture method 5.9% using the histopathological results as reference. The specificity of the above tests was 100% in goats and sheep and the specificity of the double incubation culture method in goats was 91%. CONCLUSIONS: The DNA probe test is a rapid and specific test that could be used in a control program if the sensitivity of the test were improved and possibly in combination with another test.     

棘球蚴病免疫诊断技术研究进展

综述了棘球蚴病的多种免疫诊断技术。皮内试验操作简便、迅速、敏感性高，但特异性较差，不宜作为诊断依据，可在流行病学调查中起筛查作用；间接血凝试验快速简易，重复性好，特异性和敏感性较高，具有一定的诊断价值；胶乳凝集试验虽然操作方法简便，但敏感性较低；ELISA操作简便，敏感性高，特异性强，适用于临床诊断和流行病学调查时使用，目前已作为包虫病临床辅助诊断的常规技术之一；DNA探针技术由于其敏感性高，特异性强，是将来发展方向之一。     

PCR结合斑点杂交技术检测禽多瘤病毒方法的建立及应用

鹦鹉幼雏病是由禽类多瘤病毒(APV)引起的多种鹦鹉雏鸟死亡的急性病毒性传染病,严重危害鹦鹉养殖业的健康发展.为提高分子生物学方法检测APV的敏感性和特异性,对APV基因片段进行克隆和序列分析,设计合成1对特异性引物,以VP1基因为模板,经PCR扩增获得731 bp的核苷酸DNA,并用DIG标记,制备用于检测APV的特异...     

Use of an Alkaline Phosphatase‐Labelled Probe for the Detection of Mycoplasma synoviae in Chickens

Short nucleotides directly labelled to alkaline phosphatase (SNAP probes) are an interesting alternative to digoxigenin‐labelled probes (DIG probes), because they reduce the number of steps necessary in dot blots for the detection of DNA or amplificate. This study examined the questions whether a SNAP probe might not only save time, but also increase the sensitivity of another PCR‐based DNA probe test using a digoxigenin probe. Amplificates obtained by multispecies polymerase chain reaction (PCR), with either purified genomic DNA or DNA extracted from tracheal swabs taken in chicken flocks, were detected by both methods. The results for the clinical specimens were compared to culture. Under stringent conditions, the specificity and sensitivity obtained with the SNAP probe were comparable to the results obtained with the DIG probe. The quantities 10 fg (SNAP probe) and 100 fg (DIG probe) of purified Mycoplasma synoviae DNA were detected after amplification, but more positive clinical specimens were detected with the DIG probe. Under non‐stringent conditions sensitivity with purified DNA did no change, but the coloration of the dots improved markedly, and more positive specimens could be detected with the SNAP probe than with the DIG probe, truly positives as confirmed by culture. Because cross‐reaction with Mycoplasma gallisepticum and Mycoplasma imitans, two species with DNA that was also recognized by the multispecies primers, occurred under non‐stringent conditions, it was concluded that, to take the full advantage of SNAP probes, their use in combination with species‐specific primer pairs is recommended. PCR as a method for mycoplasma detection is however, always accompanied with serological and cultural methods. When a M. synoviae mono‐infection is likely by serological results, non‐stringent dot blot conditions and use of the SNAP probe will ease and improve the detection of mycoplasma.     

探针实时荧光定量PCR检测白藜芦醇体外抗鸭瘟病毒活性方法的建立及应用

建立以TaqMan荧光探针为特点的PCR,检测白藜芦醇体外抗鸭瘟病毒活性。本研究针对鸭瘟病毒UL30基因序列设计特异性引物和TaqMan荧光探针,建立鸭瘟病毒TaqMan探针实时荧光定量PCR检测方法,并验证方法的特异度、敏感度和稳定性及对临床样品进行检测;运用该方法检测白藜芦醇对鸭胚成纤维细胞接种鸭瘟病毒后细胞中病毒增殖情况的影响,用以评价该药物体外抗鸭瘟病毒效果。结果显示,该方法建立的定量标准曲线阈值循环数（Threshold cycle,Ct）与模板拷贝数呈良好线性关系（R2=0.997）,斜率为-3.328,扩增效率（E）为99.7%,具有良好的特异度、敏感度和稳定性并能对临床样本进行准确的检测。运用该方法检测白藜芦醇体外抗鸭瘟病毒结果显示：经白藜芦醇处理后,染毒细胞中病毒拷贝数为（7.71±0.37）×10^4,与病毒对照组比较（5.63±0.26）×10^6明显减少（P〈0.01）。结果表明,TaqMan探针实时荧光定量PCR方法建立并成功用于体外药物抗鸭瘟病毒的检测;白藜芦醇具有良好的体外抗鸭瘟病毒活性。     

猪伪狂犬病病毒野毒LNA探针real-time PCR检测方法的建立

本研究根据猪伪狂犬病病毒gE基因保守区域设计特异性引物和LNA-TaqMan探针,建立了基于LNA-TaqMan探针的猪伪狂犬病病毒野毒株荧光定量PCR检测方法.结果显示:所建立的方法能够特异性的检测出猪伪狂犬病病毒野毒株;灵敏度更高,最低检测下限为10个拷贝/μL;批内变异系数和批间变异系数分别为0.43％～0.64...