畜禽及环境中沙门氏菌的PCR快速检测与控制

本文运用PCR技术检测家畜及环境中的沙门氏菌,25种沙门氏菌均获得特异性扩增,3种非沙门氏菌检测结果为阴性。表明PCR技术具有快速简便、敏感高和特异性强等优点,值得在沙门氏菌的快速检测中推广应用。并简要介绍了沙门氏菌的相关控制措施。     

畜禽及环境中沙门氏菌的PCR快速检测与控制

本文运用PCR技术检测家畜及环境中的沙门氏菌，25种沙门氏菌均获得特异性扩增，3种非沙门氏菌检测结果为阴性。表明PCR技术具有快速简便、敏感高和特异性强等优点，值得在沙门氏菌的快速检测中推广应用。并简要介绍了沙门氏菌的相关控制措施。     

多重PCR技术在食品微生物检测中的应用进展

聚合酶链式反应(polymerase chain reaction,PCR)技术在微生物检测中具有快速、灵敏、操作简单等优点,而多重PCR检测还可以同时扩增多个目的基因,对高效快速检测具有重要意义,已经成为近几年来的研究热点。作者对近来多重PCR技术在食品病原微生物、食品非致病微生物及相关环境食品微生物中应用的研究现状,以及未来在食品检测中的应用展望进行了综述。     

多重PCR技术在猪病检测中的应用

多重PCR技术是一种实用的分子诊断技术,该技术能在同一反应体系中同步扩增多个目的片段,具有高效、快捷、敏感、特异等优势,适用于对大量临床样本的快速检测。本文就多重PCR的技术原理、在猪病检测中的技术类型(常规技术、分型技术、创新技术)等进行了叙述。     

重组酶聚合酶扩增技术及其在牛病原检测中的应用

重组酶聚合酶扩增技术(RPA)是2006年由英国科学家研发的一种核酸恒温扩增技术,它不同于传统的PCR扩增,可在恒温条件下短时间内实现靶基因大量扩增,具有恒温、快速、便携、灵敏度高、特异性强、操作简单等优点,具有广阔的应用前景。本文综述了RPA技术的原理、引物设计与反应条件、产物检测方式及在牛病原检测中的应用等内容,旨在为牛病原检测新技术、新方法的研制提供参考。     

PCR在肉类科学中的应用

聚合酶链式反应技术是一项体外酶促扩增DNA技术,具有特异性强、敏感性高、操作简便、快速高效等特点,在肉品科学方面有潜在的应用价值。综述了PCR在肉类科学中的应用,如微生物的检测、肉类品种的鉴定等。     

动物疫病PCR检测实验室的污染与对策

PCR(polymerase chain reaction,聚合酶链式反应)技术是美国Cetus公司人类遗传研究室的科学家Mullis于1985年发明的一种在体外快速扩增特定基因或DNA序列的方法,又称为基因的体外扩增法。这种技术操作简单,容易掌握,有极高的灵敏度,结果可靠。近几年,随着PCR相关技术的发展,复合PCR、定量PCR、荧光PCR等PCR技术在动物疫病的快速检测方面得到了广泛应用,为动物疫病的诊断及检验检疫提供了良好的依据。但该方法较强的扩增能力也带来了令人头痛的问题?易污染,极其微量的污染即可造成假阳性的产生。1引起PCR污染的因素1.1 PCR试剂的…     

环介导等温扩增技术及其在鸡病诊断中的应用

环介导等温扩增技术(Loop-mediated Isothermal Amplification,简称LAMP)是一种体外等温扩增核酸片段的新技术,利用4条特异性引物,在Bst DNA聚合酶的催化下能够有效地扩增出靶基因。与常规PCR法相比该法具有特异性强、灵敏度高、快速准确以及操作简便等优点,现已广泛应用于动物疾病检测中。此文综述了LAMP技术原理及其在鸡传染性疾病病原检测中的应用,旨在为该技术的深入研究和应用提供参考。     

RAPD技术及其在动物医学中的应用

RAPD技术即随机扩增多态性DNA技术，是一种建立在PCR基础上的新的DNA多态性检测技术，其主要特点是利用随机寡核苷酸引物扩增基因组DNA片段，通过凝胶电泳分析其指纹图谱特征。该技术具有快速灵敏，程序简便等优点，现已经广泛应用于多个领域，此文综述了RAPD技术的原理、优缺点、影响因素及其在动物医学中的应用。     

布鲁氏菌鉴定和检测方法研究进展

布鲁氏菌是重要的人畜共患病病原菌，其鉴定和检测方法受到国内外的普遍重视。本文对近年来布鲁菌DNA同源性及其内切酶图谱分析、血清学检测、PCR扩增、核酸探针杂交等鉴定、检测方法进行了综述，并展望了分子生物学技术在布鲁氏菌快速、准确鉴定、检测中的良好前景。     

Rapid diagnosis of vibriosis and white spot syndrome (WSS) in the culture of shrimp, <Emphasis Type="Italic">Penaeus monodon</Emphasis> in Philippines

Viral and bacterial pathogens have raised serious concerns in the sustainability of the shrimp culture industry in the Philippines. Heavy mortality associated with luminous vibriosis and white spot syndrome virus (WSSV) infection has been the major problem besetting the industry. Using published PCR protocols for the diagnosis of vibriosis and white spot syndrome virus (WSSV) disease in shrimp, we optimized these assays that could be suited to the shrimp aquaculture setting in the Philippines. Genomic DNAs of Vibrio spp. that exhibited luminescence as well as those that grew on thiosulfate citrate bile salt sucrose agar (TCBS) were used for the PCR amplification of the ribonuclease P (RNase P) gene. There was differential amplification of the RNase P gene based on the phenotypic characters of the Vibrio spp. Similar results were also obtained using direct colony PCR of the bacterial colonies. White spot syndrome virus was also detected in the infected shrimp and there were differences in the detection frequency in relation to the tissues used for PCR amplification. Duplex PCR was also optimized that could be used for simultaneous detection of these pathogens in shrimp.     

根据线粒体保守序列检测鹿属动物源性成分

本文根据鹿线粒体mtDNA细胞色素b中的保守序列 ,设计了针对鹿属动物的特异性扩增引物。通过聚合酶链反应 (PolymeraseChainReac tion,PCR)得到 1 94bp的特异片段 ,而其它动物如鸡、牛、羊、兔、猪、鱼、骆驼、马等中则无此条带。通过内切酶AlwI酶切可对扩增结果进行验证。该方法对鹿成分的检测低限为 0 1 % ,可作为饲料中鹿属动物源性成分鉴别检测的有效方法之一 ,也可作为鹿类药材真伪鉴别的方法。     

The effect of the DNA preparation method on the sensitivity of PCR for the detection of Trypanosoma evansi in rodents and implications for epidemiological surveillance efforts

Trypanosoma evansi is responsible for the most largely distributed animal trypanosomosis, affecting a wide range of wild and domestic animals. Its surveillance requires the implementation of standardized and reliable diagnostic tools. Although the development of polymerase chain reaction (PCR) tools has greatly improved our diagnostic capacity, factors affecting their sensitivity need to be acknowledged and accounted for in the interpretation of results. The targeted gene and the primer design have already been shown to greatly affect the sensitivity of a PCR, and the best-performing sets of primers have been previously identified. However, the sensitivity of the PCR is also largely influenced by the DNA extraction or sample preparation method. In this paper, we selected 6 DNA extraction or blood sample preparation methods representative of what would be used in a budget-constrained setting: phenol–chloroform, Chelex^®, Flexigen (Qiagen^®) kit, Genekam^® kit and two original protocols using sodium hydroxide. We studied the effects of the preparation method on the detection limit of the subsequent PCR. Our results show that the extraction method strongly affects the PCR sensitivity. The classical phenol–chloroform extraction method allowed for the PCR with the lowest detection limit. Some combinations of extraction method and primer set had detection limits that were not compatible with their use as a reliable diagnostic test, and would severely reduce the performance of a surveillance program. Therefore, we encourage laboratories to carefully select their sample preparation and PCR protocols, depending on the aimed sensitivity, cost, safety, time requirement and objectives.     

Rapid detection of porcine reproductive and respiratory syndrome viral nucleic acid in blood using a fluorimeter based PCR method

Porcine reproductive and respiratory syndrome virus (PRRSV) is an Arterivirus recognised world wide as an important cause of reproductive failure and pneumonia in pigs. American and European strains of PRRSV, differentiated antigenically and genomically, have been reported. PRRSV infections are currently diagnosed using serology, virus isolation and/or immunocytochemistry. In order to overcome various drawbacks associated with these techniques, conventional, block-based RT-PCR methods for the detection of PRRSV nucleic acid in clinical samples have been described. These methods require gel electrophoresis for analysis of PCR products and present high risk of DNA carry-over contamination between the samples tested. We describe the detection of PRRSV RNA in serum samples and in blood impregnated filter disks (FDs), obtained from experimentally inoculated pigs, using a closed-tube, fluorimeter-based PCR assay. The assay eliminates the use of gel electrophoresis, and is as sensitive and specific as the conventional block-based PCR assay, detecting positive samples as early as 1 day post-inoculation. We also report a rapid fluorimeter based PCR method for differentiating American and European strains of PRRSV.     

分子生物学技术在病毒性传染病中的临床应用

分子生物学方法目前是病毒检测和定性的一部分。PCR 技术可以检测传统病毒学方法检测不到的病毒,为病毒学进一步研究提供了技术平台。分子方法不仅能检测到抗生素抗性基因,而且还能进行病毒株基因分型,为公众提供健康信息。通过对抗病毒治疗应答的监控可检测到病毒抑制和病毒量,大大提高病毒的治疗水平。随着多重 PCR、实时定量荧光 PCR 出现和自动化效率的提高,分子检测方法价格将不断降低,分子方法发挥的作用将进步增加。这篇文章将重点叙述分子生物学方法在临床病毒学检测中的应用情况,通过一些例子阐明这些方法如何改变实验室诊断,达到防治病毒性传染病的目的。     

禾草内生真菌检测方法研究进展

从最初发现黑麦草(Lolium perenne)和高羊茅(Festuca arundinacea)引起家畜中毒到后来其携带的内生真菌被发现,以及进一步的研究证实,内生真菌的存在不但导致家畜中毒而且能显著提高宿主在群落中的竞争力,也因禾草内生真菌的这种重要生理和生态作用,使其逐步成为国内外研究的热点之一,这也给内生真菌检测技术的发展提供了契机。初期主要是借鉴病原真菌等微生物检测的一些较成熟的方法,对禾草内生真菌进行染色镜检或分离检测,但容易受宿主种类、物候期、检测部位等因素的影响,造成检测结果的不准确。随着分子生物学、遗传学等学科的快速发展,酶联免疫吸附测定法(enzyme linked immunosorbent assay,ELISA)、聚合酶链式反应法(polymerase chain reaction,PCR)、实时荧光PCR法(realtime PCR)等现代分子技术在禾草内生真菌方面的应用和改进,使得内生真菌的检测方法不断推陈出新,这些方法能在一定程度上对传统检测方法给予有效的补充。快速有效的确定禾草内生真菌的存在、分布规律、分类地位等,需要准确合理地选择特异性较强的检测方法,例如定性或定量检测,并结合经典的染色镜检和分离法对禾草内生真菌进行确定。本研究对以上内容进行了综述,以期更深层次的借鉴和发展关于其它微生物的经典检测方法,同时开发具有禾草内生真菌特异性的检测技术,这些技术不仅能够鉴定内生真菌存在与否,而且能对内生真菌进行定量和活性的检测,是发展的重要方向和热点。对内生真菌定性、定量和活性的检测是未来值得研究的重点。     

Detection of porcine circovirus type 1 in commercial pig vaccines using polymerase chain reaction

The absence of extraneous viruses is a requirement in the quality control of vaccines for veterinary use in the European Pharmacopoeia. A polymerase chain reaction (PCR) assay for the detection of porcine circovirus type 1 (PCV1) and type 2 (PCV2) was evaluated in 18 commercial porcine vaccines. Since vaccine components may contain PCR enhancers or inhibitors, 13 of the studied vaccines (used as diluents) were subsequently spiked with different dilutions of PCV2 and tested by PCR. Although PCV2 DNA was not detected in any of the vaccines tested, PCV1 was detected in 2/18 vaccines (11%). Eleven out of 13 PCV2 spiked vaccines showed a positive PCR result. The lack of amplification observed in two spiked vaccines suggested that use of the PCR assay to detect PCV2 could depend on vaccine composition. The results of this exploratory study have demonstrated that PCR is a rapid and fairly sensitive method for the detection of porcine circoviruses as extraneous agents in vaccine products and can be used in the quality control of pig vaccines. The study has also indicated the need for optimising the sensitivity of PCR methods for PCV genome detection in vaccine products.     

Molecular genetic methods in the veterinary clinical bacteriology laboratory: current usage and future applications

In the last 5 years, numerous molecular methods have been published for the detection and characterization of bacteria in the field of veterinary medicine. PCR has been the most commonly used technology. Although not currently used for clinical veterinary diagnosis, new technologies such as liquid-phase hybridization, real-time PCR, pathogen load determination and DNA/protein microarray have been described and have many possible applications in the clinical bacteriology laboratory because of their sensitivity and efficiency. This review describes the basic principles and application of recently published DNA-based molecular techniques for the purpose of veterinary clinical bacteriological diagnosis. It covers advances in probe hybridization technology, DNA/RNA amplification techniques and other molecular detection methods, including 16S rRNA analysis for bacterial characterization and DNA microarrays for bacterial detection. The review briefly summarizes the application of molecular methods for the diagnosis of specific important bacterial infections of animals, and for other animal pathogens that are slow or difficult to isolate in the clinical bacteriology laboratory. In addition, the molecular detection of antimicrobial resistance genes and of bovine mastitis pathogens is briefly described and current commercially available tests are listed.     

Efficacy of a modified polymerase chain reaction assay for detection of Ehrlichia canis infection.

Detection of Ehrlichia canis in acutely infected and convalescent dogs is important for effective treatment and control. However, accurate detection has been difficult to achieve, in part because dogs that have been treated therapeutically often remain seropositive for extended periods. A new method, polymerase chain reaction (PCR) assay using biotinylated E. canis-specific primers (PCR-BP), was developed for detection of E. canis. Four dogs experimentally infected with E. canis by intravenous inoculation of whole blood from carrier dogs and 2 naturally infected convalescent carriers were used to compare the specificity and sensitivity of the new method with that of microscopy/blood smear evaluation, serologic test, and conventional PCR assay using E. canis-specific primers. In experimentally infected animals, infection was detected as early as 7 days post-exposure using PCR-BP. Although the 2 naturally infected dogs were positive by serologic test and PCR-BP, both were negative by conventional PCR. Results suggest that the new method is a sensitive assay for detection of E. canis infection. In addition, results were obtained more rapidly than with other PCR-based assays.     

金色葡萄球菌、伤寒沙门氏菌和副溶血弧菌单管多重PCR检测方法的建立及初步应用

本研究根据金黄色葡萄球菌（Staphylococcus auretls，SA）耐热核酸酶（nut）基因、伤寒沙门氏菌（Salmonella typhi，ST）鞭毛抗原（H1-d）基因和副溶血性弧菌（Vibrio parahaemolyticus，VP）热稳定直接溶血素（tdh）基因，分别设计了三对引物Nuc-F／Nu-R、H1-d—F／H1-d—R和Tdh-F／Tdh-R，预计PCR扩增的DNA片断分别为279bp、202bp和458bp。通过对单个基因PCR和单管多重PCR扩增的特异性、敏感性分析以及对单管多重PCR扩增条件如引物浓度、退火温度和dNTP浓度等的优化，建立了快速检测金黄色葡萄球菌、伤寒沙门氏菌和副溶血弧菌的单管多重PCR方法，该方法检测的敏感性分别为：47．8PgST的基因组DNA．22．7PgSA的基因组DNA和0．3745PgVP的基因组DNA。模拟试验显示最低检测限度为分别为：SA150CFU／反应体系，ST98CFU／反应体系，VP53CFU／反应体系。表明该方法具有很好的应用价值和开发前景。