用荧光定量RT-PCR方法检测猪瘟病毒

为了建立能特异检测不同基因型猪瘟病毒(Classical swine fever virus,CSFV),同时又能区分其他瘟病毒的基因检测方法,本实验针对CSFV基因组5′端非编码区设计并合成了简并引物和TaqMan探针,在优化反应条件的基础上,成功地建立了特异检测CSFV的荧光定量RT-PCR检测方法。再以已知滴度的CSFV石门株血毒总RNA反转录产物建立标准品,该标准品可以用于定量临床样品中的CSFV滴度,所建立的荧光定量PCR方法可以灵敏地检测出10~(-0.82)个TCID_(50)病毒含量。最后用建立的方法对108份临床样品进行检测并同时进行病毒分离,荧光定量PCR方法检测出73份阳性样品且与病毒分离的符合率为100%,而常规RT-PCR只检测出54份阳性样品,表明本荧光定量RT-PCR法在检测猪瘟病料上具有潜在的应用价值。     

猪瘟病毒荧光RT-PCR快速检测方法的建立

以猪瘟病毒5＇端非编码区为靶核酸序列设计引物和探针，建立了一步法荧光RT-PCR检测猪瘟病毒。荧光RT-PCR仅检测出猪瘟C株、T株，未能检测出牛病毒性腹泻病毒（BVDV）、猪呼吸系统冠状病毒、猪传染性胃肠炎病毒、猪细小病毒、伪狂犬病病毒、猪生殖与呼吸综合征病毒、PK-15细胞和牛睾丸原代细胞；对猪瘟病毒T株的扩增反应产物进行了测序分析，与预期序列相符。荧光RT-PCR的检测极限可达到1 TCID50／mL，整个试验流程只需2h。采用荧光RT-PCR和抗原捕获ELISA同时检测临床病料、猪副产品共207份样本，两种方法的检出率分别为17．4％和13．5％，两者符合率为95．7％（198／207）；荧光RT-PCR的检出率高于ELISA，两者差异显著。结果表明，建立的荧光RT-PCR可用于猪产品、临床病料中猪瘟病毒的快速检测。     

Simultaneous vaccination of piglets against foot-and-mouth disease and classical swine fever

Six-week-old piglets, born of unvaccinated sows, were vaccinated against foot-and-mouth disease (FMD) with a trivalent, inactivated vaccine containing an adjuvant or vaccinated against classical swine fever (CSF) with a live attenuated vaccine or against both diseases simultaneously at two different sites. The antibody response to the FMD vaccine was not significantly influenced by the simultaneous vaccination against CSF. FMD vaccine administered simultaneously with the CSF vaccine produced a significantly higher antibody response to CSF than occurred with CSF vaccination only.     

实时荧光RT-PCR快速检测猪源性食品中猪瘟病毒的研究

为快速检测食品中的猪瘟病毒(CSFV),本研究参照GenBank中登录的CSFV序列,设计引物及特异性TaqMan探针,利用实时荧光PCR技术,以质粒作为阳性标准品,建立特异、敏感、重复性好的CSFV快速定量检测方法.用本方法对几种不同猪源性食品(盐渍肠衣、鲜肉和腌肉)中的CSFV进行检测,结果显示该方法比普通RT-PCR具有更高的敏感性.本研究表明,该实时荧光RT-PCR能用于猪源性食品中的CSFV检测.为快速、准确检测动物源性食品中CSFV提供一条新途径.     

Evaluation of real-time RT-PCR assay for the routine intra vitam diagnosis of classical swine fever

The aim of the study was to evaluate the diagnostic quality of the real-time RT-PCR assay described by Hoffmann et al. [Hoffmann, B., Beer, M., Schelp, C., Schirrmeier, H., Depner, K., 2005. Validation of a real-time RT-PCR assay for sensitive and specific detection of classical swine fever. J. Virol. Methods 130, 36-44] for the routine intra vitam diagnosis of classical swine fever (CSF). We compared the assay with conventional diagnostic methods by using defined diagnostic material from an animal experiment with pigs showing different clinical forms of CSF. Compared to virus isolation and antigen ELISA an enhanced sensitivity of the real-time RT-PCR could be shown. We were able to detect all infected pigs regardless of the clinical course of CSF. CSF infection was detected already during the incubation period, during the entire clinical phase as well as at the beginning of convalescence when the first antibodies were detected and no virus could be isolated any more. In most cases, positive PCR results were obtained 2 days earlier than with virus isolation and 2-4 days earlier than with the antigen ELISA.     

用RT-PCR技术检测盐渍猪肠衣中猪瘟病毒的研究

参考GenBank中发表的猪瘟病毒（CSFV）序列，设计一对CSFV特异性PCR引物；从CSFV感染猪盐渍小肠中提取总RNA，经逆转录后进行PCR扩增，在盐渍小肠中成功扩增出与预期大小（168bp）一致的特异性条带，而正常猪和感染猪伪狂犬病病毒的猪小肠扩增结果均为阴性。用本方法对20例不同稀释浓度的盐渍猪肠衣样本进行检测，结果显示比经典抗原检测方法（抗原捕获ELISA法）具有更高的敏感性。实验表明，本RT—PCR技术能应用于盐渍猪肠衣的CSFV检测，为快速、准确检测盐渍猪肠衣中CSFV提供了一条新途径。     

塞内卡病毒和口蹄疫病毒二重实时荧光RT-PCR鉴别检测方法的建立

为了建立一种快速、敏感、特异的能够鉴别诊断口蹄疫病毒(FMDV)和塞内卡病毒(SVV)二重实时荧光RT-PCR方法,根据FMDV及SVV的保守基因序列,设计了2套特异性引物和不同荧光素标记的MGB探针。通过对PCR反应体系和反应条件的优化筛选,建立了FMDV和SVV二重实时荧光RT-PCR检测方法,并对二重实时荧光RT-PCR检测方法进行了特异性、敏感性、重复性试验;利用所建立的方法对98份疑似FMDV和SVV感染的临床样品进行了检测。结果显示,成功建立的FMDV及SVV二重实时荧光RT-PCR检测方法,模板在10~1～10~7拷贝/μL有很好的线性关系;对pGEM-T/FMDV和pGEM-T/SVV重组质粒出现阳性扩增信号,但对正常细胞培养物对照和其他7种病原对照未扩增出特异性曲线,方法特异性较好;最低检测模板浓度为10拷贝/μL;自98份疑似FMDV和SVV感染样品中检出9份FMDV阳性,10份SVV阳性,2份FMDV和SVV双阳性,并且和克隆测序结果一致。本研究建立的FMDV及SVV二重实时荧光RT-PCR检测方法,可用于FMDV和SVV的快速鉴别检测,为FMDV和SVV的鉴别诊断提供特异、敏感和高通量的方法。     

Comparison of two real-time RT-PCR assays for differentiation of C-strain vaccinated from classical swine fever infected pigs and wild boars

Classical swine fever is one of the most important infectious diseases for the pig industry worldwide due to its economic impact. Vaccination is an effective means to control disease, however within the EU its regular use is banned owing to the inability to differentiate infected and vaccinated animals, the so called DIVA principle. This inability complicates monitoring of disease and stops international trade thereby limiting use of the vaccine in many regions. The C-strain vaccine is safe to use and gives good protection. It is licensed for emergency vaccination in the EU in event of an outbreak. Two genetic assays that can distinguish between wild type virus and C-strain vaccines have recently been developed. Here the results from a comparison of these two real-time RT-PCR assays in an interlaboratory exercise are presented. Both assays showed similar performance.     

口蹄疫病毒TaqMan荧光定量PCR检测方法的建立

为建立检测口蹄疫病毒(FMDV)的方法,本研究根据GenBank中FMDV的2B基因序列,设计合成一对引物和一条TaqMan探针,将2B基因克隆到pBlueScriptSK(-)载体中,利用T7体外转录试剂盒制备标准品,通过优化反应条件,建立了TaqMan荧光定量PCR检测方法.结果表明,该检测方法的敏感性达到102拷贝/μL;与其它主要相关病毒均不发生交叉反应,批内和批间试验重复性的变异系数(CV)均小于3％.本研究建立的FMDV TaqMan荧光定量PCR方法对FMDV的快速检测具有重要意义.     

African swine fever and classical swine fever: a review of the pathogenesis

This paper describes major pathogenetic mechanisms of African and Classical Swine Fever virus infections. The interactions between both viruses and the monocyte-macrophage-system result in the release of mediator molecules, which are important for the further progression of the diseases. The causes of the thrombocytopenia and the mechanisms of the haemorrhages, which are characteristic in both infections, are described. Apoptotic cell death is regarded as the predominant cause of lymphopenia in both virus infections.     

Virus survival in slurry: analysis of the stability of foot-and-mouth disease, classical swine fever, bovine viral diarrhoea and swine influenza viruses

Farm slurry can be highly contaminated with viral pathogens. The survival of these pathogens within slurry is important since this material is often distributed onto farm land either directly or after heat treatment. There is clearly some risk of spreading pathogens in the early stages of an outbreak of disease before it has been recognized. The survival of foot-and-mouth disease virus, classical swine fever virus, bovine viral diarrhoea virus and swine influenza virus, which belong to three different RNA virus families plus porcine parvovirus (a DNA virus) was examined under controlled conditions. For each RNA virus, the virus survival in farm slurry under anaerobic conditions was short (generally ≤ 1 h) when heated (to 55°C) but each of these viruses could retain infectivity at cool temperatures (5°C) for many weeks. The porcine parvovirus survived considerably longer than each of the RNA viruses under all conditions tested. The implications for disease spread are discussed.     

猪瘟病毒垂直感染的检测

猪瘟是一种急性、高度接触性传染的一种重要传染病。近年来猪瘟流行的方式发生了改变，典型猪瘟逐渐减少，非典型猪瘟逐渐增多，表现怀孕母猪流产，产死胎、木乃伊和病弱的仔猪等，尤其是新生仔猪猪瘟，临床症状不十分明显，但发病率、病死率较高，严重危害养猪业的发展。关于新生仔猪猪瘟的发生，多认为是母猪怀孕期间感染猪瘟病毒而通过垂直传播的方式引起仔猪感染，但到目前为止未见有关新生仔猪垂直感染猪瘟病毒的直接证据。     

繁殖障碍型猪瘟的研究进展

猪瘟是威胁我国乃至全世界养猪业的主要疾病。目前该病的流行和发病特点发生了很大变化 ,本文仅就繁殖障碍型猪瘟的发病情况、发病特点及其防制的研究进展作一综述     

应用套式RT—PCR检测猪瘟制品中牛病毒性腹泻病毒污染的研究

为建立猪瘟制品中牛病毒性腹泻病毒（BVDV）污染的诊断方法,本研究根据GenBank公布的BVDV全基因组序列,选择BVDV保守性比较高的5′非编码区,利用Olig06．0软件设计了2对特异性引物,建立了检测BVDV的套式RT-PCR方法。该方法极大提高了常规RT-PCR检测方法的特异性和敏感性,重复性好、特异性强、敏感性高,可以准确快速检测出极低含量的BVDV,为动物与疫苗生物制品原辅料中BVDV的快速低含量检测提供了一种简单、特异、敏感、快速的检测方法。     

食源性动物组织中CSFV和PRRSV双重双色荧光定量RT-PCR检测方法的建立及应用

为建立同时检检测食源性动物组织中猪瘟病毒(CSFV)和猪蓝耳病病毒(PRRSV)的双色荧光定量RT-PCR方法。本研究根据SCFV和PRRSV基因序列设计特异性的引物和不同荧光标记的TaqMan荧光探针,通过优化反应的体系和扩增条件,建立了能够检测食源性动物组织中SCFV和PRRSV的双重双色荧光定量PCR的方法。其检测下限为1×102拷贝/μL,而且与其他一些猪病病毒无交叉反应,具有良好的特异性。该方法重复性和稳定性试验表明其组内和组间的变异系数最高分别为4.2和4.5。对比试验表明,该方法对CSFV和PRRSV检验的敏感性为常规RT-PCR方法的200倍;该方法的建立为食源性动物组织中CSFV和PRRSV提供了有效手段,该方法特异性和敏感性较好,能够应用于临床检测。