Detection of Gallibacterium anatis by TaqMan fluorescent quantitative PCR

To better understand the prevalence of Gallibacterium anatis in different poultry species, a rapid and accurate method was developed to detect G. anatis using a TaqMan fluorescent quantitative polymerase chain reaction (qPCR). Specific primers and a TaqMan probe were designed based on the reference gtxA gene sequence. The qPCR standard curve showed a good linear relationship, and the method showed good reproducibility, sensitivity, and specificity, indicating its suitability for G. anatis identification and quantitative analysis. A comparison of the detection results in 160 clinical swab samples showed that the detection rate (54.4%) of the qPCR for G. anatis was better than that of two conventional methods: gyrB gene-based qPCR for G. anatis (51.9%) and culture-based identification (34.4%). G. anatis was detected in layer chicken (77.3%), Silkie chicken (72.7%), and duck (27.1%) with relatively high detection rates, whereas dove (8.8%) and quail (3.0%) showed lower detection rates, indicating the different prevalence of G. anatis in different fowl species.     

Association Patterns of Endothelial Nitric Oxide Synthase Gene (NOS3) Variant Glu298Asp with Blood Pressure and Serum Lipid Levels in Subjects with Coronary Artery Disease from Pakistan

Nitric oxide is an important antiatherosclerotic agent. The main determinant of nitric oxide levels is enzyme nitric oxide synthase encoded by the NOS3 gene, the common variants in this gene may be responsible for variations in plasma enzyme levels. The association of NOS3 variants with coronary artery disease (CAD) varies in different ethnicities. The current study aimed to determine the association of NOS3 Glu298Asp (rs1799983) with CAD and blood lipid levels in Pakistani subjects. Six hundred thirty‐six samples (412 cases, 224 controls) were genotyped by TaqMan allelic discrimination assay and serum total cholesterol, and High Density Lipoprotein cholesterol (HDL‐C)/Low Density Lipoprotein cholesterol (LDL‐C) and triglycerides were measured. The genotype frequency was Glu/Glu = 64.6%, Glu/Asp = 30.1%, and Asp/Asp = 5.3% in cases, and Glu/Glu = 68.8%, Glu/Asp = 26.7%, and Asp/Asp = 4.5% in controls. The Asp298 (T) frequency was not significantly higher in cases than controls (20.4% vs 17.9%, P = 0.28) and risk allele was not associated with CAD (OR 1.15 (0.86–1.54), P = 0.33) and the tested lipid traits but had a strong association with blood pressure (for systolic and diastolic P = 1.9×10^?–56 and 4×10^?–40, respectively). In conclusion, although Glu298Asp did not show association with CAD and lipid profile in the studied cohort, it may exert its effect through blood pressure; however, the mechanism of this effect needs to be explored in the future.     

利用荧光定量RT-PCR和PCR方法检测结核分枝杆菌复合群

目的建立一种新的检测结核分枝杆菌复合群的荧光定量试验方法(R/P分析),探讨R/P分析检测临床标本中结核分枝杆菌复合群的应用价值。方法根据结核分枝杆菌复合群基因保守序列设计引物和探针构建质粒标准品。运用R/P分析检测54例确诊结核病人临床样本,检测的结果同时与培养法、荧光定量PCR法进行比较。结果不同临床标本用R/P分析诊断结核病,其敏感性高于荧光定量PCR法和培养法,阳性检出率分别为96.3%、83.3%和55.6%。结论 R/P方法是一种快速、特异的直接检测方法,它可以区分结核分枝杆菌复合群的死菌与活菌,因此可以更好的指导医生进行治疗,更准确地做出公共卫生决策。     

口蹄疫病毒实时RT-PCR检测方法的建立

目的用TaqMan技术建立了一种实时RT-PCR的方法，用于检测口蹄疫病毒，并优选出最佳检测样品。方法设计合成一套引物和TaqMan探针，通过反应条件的优化，建立实时RT-PCR的方法，以扩增口蹄疫病毒的3D基因，并用该法检测患病仔猪的气管、前肢肌肉、皮肤、舌、颈浅淋巴结、脾脏、喉头、食管、腹股沟淋巴结、肺脏、扁桃体、肝脏、肾脏、胸肌、心脏、鼻黏膜、后肢肌肉、脑、骨髓、软腭和血清等样品。结果（1）该方法检测FMDV下限为0．01TCID50其敏感性比普通RT-PCR高100倍，并具有较好的特异性和重复性，（2）FMDV感染仔猪血清、淋巴结、扁桃体和肝脏中病毒含量较高是检测口蹄疫病毒很好的样品。结论建立了一种实时RT-PCR检测口蹄疫病毒的方法。     

弗氏枸橼酸杆菌TaqMan实时荧光定量-聚合酶链反应检测方法的建立

目的 建立针对弗氏枸橼酸杆菌的TaqMan实时荧光定量-聚合酶链反应(real time-PCR)检测方法。 方法 针对弗氏枸橼酸杆菌的特有序列设计引物和TaqMan探针,扩增目的基因建立标准曲线,确定检测方法的灵敏度;对20种其他肠道致病菌及院内感染中常见的致病菌进行检测,评价该检测方法的特异性;使用牛奶模拟标本评价方法在实际检测工作中应用性。 结果 TaqMan real time-PCR检测方法对弗氏枸橼酸杆菌重组质粒的检测灵敏度为1.0101拷贝／反应体系;该检测方法在检测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。该检测方法对牛奶模拟样本中弗氏枸橼酸杆菌检测下限为1.0102cfu/ml的菌量;通过对1.0107、1.0105和1.0103三个浓度质粒标准品的重复检测,确定本方法的组内变异系数为1.90%~3.91%;组间变异系数为1.52%~1.69%。 结论 本研究建立的TaqMan real time-PCR检测方法可作为检测弗氏枸橼酸杆菌灵敏、特异、快速的方法。     

Shrews as reservoir hosts of borna disease virus

Borna disease virus (BDV) is the causative agent of severe T-cell-mediated meningoencephalitis in horses, sheep, and other animal species in central Europe. Here we report the first unequivocal detection of a BDV reservoir species, the bicolored white-toothed shrew, Crocidura leucodon, in an area in Switzerland with endemic Borna disease.     

Genetic risk factors associated with Creutzfeld-Jakob disease in Slovenians and a rapid typing for PRNP codon 129 single nucleotide polymorphism

PRNP has been the most informative marker for the predisposition to variant Creutzfeld-Jakob disease (vCJD). All victims of the vCJD carried methionine (M) at the position 129 of the PrP. Prions could travel through the immune system to get from the gut to the brain, and human leucocyte antigens (HLAs) could be involved in this carriage, with HLA-DQ7 being less efficient. Contradictory reports have raised the question of the influence of sampling in population studies. We developed a fast and reliable real-time polymerase chain reaction for codon 129 single nucleotide polymorphism (SNP) using TaqMan technology, which overcomes the main drawbacks of other methods and analysed Slovenian population (n = 97). The comparison with other populations served for the estimation of the genetic risk for the development of vCJD in Slovenians. The frequencies at the codon 129 SNP in the Slovenian population were 43.3% M, 45.4% M/V 11.3% V. Considerable differences between the DQ7 frequencies in diverse samples from the same population can be seen, especially when compared to Slovenian population. This could be because of the diverse criteria for including subjects into the study and the sampling of geographically distinct subpopulations. Analysing the adequacy of HLA-DQ7 as a possible predictive factor for developing Creutzfeld-Jakob disease (CJD) by case - control studies could be improved with exact and equal sampling of groups of patients and controls. CJD genetic risk factors in the Slovenians were not found significantly different than those in British.     

Real-time RT-PCR for detection of Raspberry bushy dwarf virus, Raspberry leaf mottle virus and characterizing synergistic interactions in mixed infections

Two TaqMan-based real-time One-Step RT-PCR assays were developed for the rapid and efficient detection of Raspberry bushy dwarf virus (RBDV) and Raspberry leaf mottle virus (RLMV), two of the most common raspberry viruses in North America and Europe. The primers and probes were designed from conserved fragments of the polymerase region of each virus and were effective for the detection of different isolates tested in this study. The RBDV assay amplified a 94 bp amplicon and was able to detect as few as 30 viral copies. Whereas the RLMV assay amplified a 180 bp amplicon and detected as few as 300 viral copies from plant and aphid RNA extracts. Both assays were significantly more sensitive than their corresponding conventional RT-PCR methods. The sensitivity of the RLMV assay was also tested on single aphids after a fixed acquisition access period (AAP). In addition, the assays revealed a novel synergistic interaction between the two viruses, where the concentration of RBDV was enhanced ∼400-fold when it occurred in combination with RLMV compared to its concentration in single infections. The significance of this finding and the importance of the development of real-time RT-PCR assays for the detection of RBDV and RLMV are discussed.     

利用荧光定量RT-PCR和PCR方法检测结核分枝杆菌复合群

目的 建立一种新的检测结核分枝杆菌复合群的荧光定量试验方法 （R/P分析）,探讨R/P分析检测临床标本中结核分枝杆菌复合群的应用价值.方法 根据结核分枝杆菌复合群基因保守序列设计引物和探针构建质粒标准品.运用R/P分析检测54例确诊结核病人临床样本,检测的结果 同时与培养法、荧光定量PCR法进行比较.结果 不同临床标本用R/P分析诊断结核病,其敏感性高于荧光定量PCR法和培养法,阳性检出率分别为96.3%、83.3%和55.6%.结论 R/P方法 是一种快速、特异的直接检测方法,它可以区分结核分枝杆菌复合群的死菌与活菌,因此可以更好的指导医生进行治疗,更准确地做出公共卫生决策.