BVDV、IBRV和AKAV多重PCR检测方法的建立与应用

牛病毒性腹泻病毒(bovine viral diarrhea virus, BVDV)、牛传染性鼻气管炎病毒(infectious bovine rhinotracheitis virus, IBRV)和阿卡斑病毒(Akabane virus, AKAV)是引起牛发生繁殖障碍性传染病的主要病原。本研究根据BVDV的5′-UTR、IBRV的gB基因和AKAV的S基因设计了3对特异性引物,构建了检测BVDV、IBRV和AKAV的多重PCR方法,并优化反应体系和条件,验证了该方法的特异性和敏感性。结果显示,构建的多重PCR方法对其他牛源病毒无扩增,对BVDV、IBRV和AKAV的最低检测限分别为10³、10³和10⁴ 拷贝/μL。对采集的184份临床血清样品进行检测,BVDV、IBRV和AKAV的阳性率分别为18.48%、14.13%和1.63%,BVDV和IBRV 2种病原混合感染的阳性率为3.8%,BVDV和AKAV两种病原混合感染的阳性率为1.63%。该结果与我国出入境检疫行业标准符合率达92%以上,BVDV+IBRV和...     

牛诺瓦病毒和牛轮状病毒双重RAA-LFD快速检测方法的建立及应用

为建立能同时检测牛诺瓦病毒(bovine norovirus, BNoV)和牛轮状病毒(bovine rotavirus, BRV)的重组酶辅助扩增-侧流层析试纸条(recombinase aided amplification-lateral flow dipstick, RAA-LFD)快速检测方法。本试验按照RAA引物探针设计原则,分别针对BNoV RdRp基因和BRV VP7基因的保守区设计引物和探针,制备标准重组质粒,建立并优化RAA-LFD反应体系,同时对该检测方法进行特异性、敏感性及重复性评估,用建立的RAA-LFD法与PCR法、qPCR法分别对采集的168份腹泻犊牛的临床样本进行平行检测。结果显示,该方法可在20 min, 39℃的条件下扩增目标片段,对BNoV和BRV敏感度均为10³ copies·μL^-1,与PCR的检测结果基本一致,且与牛冠状病毒(bovine coronavirus, BCoV)、牛病毒性腹泻病毒(bovine viral diarrhea virus, BVDV)和牛传染性鼻气管炎病毒(infecti...     

牛病毒性黏膜/腹泻病毒与牛传染性鼻气管炎病毒双重PCR检测方法的建立

为了建立同时检测牛病毒性黏膜/腹泻病毒(BVDV)与牛传染性鼻气管炎病毒(IBRV)的双重PCR方法,试验采用文献记载的检测BVDV和IBRV的单项PCR方法,设计并合成引物,通过优化反应条件和反应体系,以及特异性和灵敏度试验,建立同时检测BVDV和IBRV的双重PCR方法。结果表明:建立的方法具有高度特异性,可同时扩增出BVDV的244 bp和IBRV的362 bp片段,而对猪瘟病毒(CSFV)与牛轮状病毒(BRV)均无扩增;并且该双重PCR方法对BVDV和IBRV的检测下限均为10 pg;用25份临床样本对双重PCR方法与单项PCR方法进行对比验证,二者的符合率为100%。说明建立的双重PCR检测方法具有特异、灵敏、快速的特点,可用于BVDV和IBRV的同时检测。     

牛病毒性腹泻病毒和牛传染性鼻气管炎病毒双重荧光定量PCR检测方法的建立

为建立牛病毒性腹泻病毒(BVDV)和牛传染性鼻气管炎病毒(IBRV) TaqMan双重荧光定量PCR检测方法,本研究根据GenBank中已登录的BVDV 5'-UTR基因序列和IBRV gB基因序列,设计了2对特异性引物和2条TaqMan探针。结果显示以含有BVDV 5'-UTR基因和IBRV gB基因的重组质粒为模板绘制的标准曲线,其相关系数(R~2)均大于0.990,线性关系较好。特异性试验结果显示,该方法仅对BVDV和IBRV检测为阳性,而对口蹄疫病毒、牛流行热病毒、牛副流感病毒、牛轮状病毒、牛巴氏杆菌、猪瘟病毒、牛支原体、牛、羊布鲁氏菌检测结果均为阴性,表明其特异性强。该方法的检测下限约为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%,利用OIE采纳的BVDV、IBRV荧光定量PCR方法与本实验建立的方法分别对47份牛病料样品进行检测,二者对BVDV和IBRV检测的符合率分别可达97.87%和100%。研究表明所建立的荧光定量PCR方法具有快速、敏感、准确等优点,可以用于BVDV和IBRV的双重定量检测。     

牛传染性鼻气管炎病毒SYBR GreenⅠ荧光定量PCR检测方法的建立

为检测牛传染性鼻气管炎病毒,通过设计针对gB基因的特异性引物扩增gB基因,构建阳性重组质粒。经过优化建立了牛传染性鼻气管炎病毒的SYBR GreenⅠ荧光定量PCR检测方法。结果显示,建立的实时荧光定量PCR检测方法在阳性标准质粒拷贝数在5.474×10⁴～5.474×10⁹拷贝/μL时线性关系良好,线性相关系数R²=0.999 3。该方法最低检测限为5.747×10²拷贝/μL;可以特异性检测牛传染性鼻气管炎病毒(IBRV),与牛病毒性腹泻病毒(BVDV)、牛副流感病毒(BPIV)、牛呼吸道合胞体病毒(BRSV)不发生交叉反应。病毒滴度与拷贝数的线性关系良好,线性相关系数R²=0.985 4。该方法为牛传染性鼻气管炎病毒的快速检测提供了技术支持。     

牛病毒性腹泻病毒、牛传染性支气管炎病毒和口蹄疫病毒多重TaqMan荧光定量PCR检测方法的建立

为建立同时快速鉴别检测牛病毒性腹泻病毒(BVDV)、牛传染性支气管炎病毒(IBRV)和口蹄疫病毒(FMDV)的方法,本研究根据高度保守的BVDV的5'UTR基因、IBRV的g B基因和FMDV的3D基因,分别设计了3对对应的特异性引物和3种不同发光基团标记的Taq Man探针,建立了同时检测这3种病毒的多重荧光定量PCR的方法。并对其反应条件进行优化。结果表明,该多重荧光定量PCR方法能够特异性检测出BVDV、IBRV和FMDV,而对BTV等检测结果均为阴性,对BVDV、IBRV、FMDV的最低检测量分别为194拷贝/μL、208拷贝/μL和150拷贝/μL。而且组内和组间变异系数均低于0.85%。本研究所建立的多重荧光定量PCR具有方便、快速、特异性好、灵敏度高、重复性好等优点,能够用于BVDV、IBRV和FMDV的同时检测。     

牛传染性鼻气管炎病毒和牛病毒性腹泻病毒双重荧光定量PCR检测方法的建立

为建立基于TaqMan探针的双重荧光PCR技术检测牛传染性鼻气管炎病毒(IBRV)和牛病毒性腹泻病毒(BVDV)的方法,根据IBRV gB基因序列和BVDV 5′端非编码区序列的保守区域,分别设计1对IBRV的特异性引物和1条FAM标记的TaqMan探针,1对BVDV的特异性引物和1条ROX标记的TaqMan探针,建立双重荧光定量PCR检测IBRV和BVDV的方法。对建立的检测方法进行特异性和敏感性测定,并用临床样品进行检测验证。特异性试验结果显示,该方法检测参试的IBRV毒株,在波长530μm(FAM)时收集到特异性荧光信号曲线,检测参试的BVDV毒株,在610μm(ROX)时收集到特异性荧光信号曲线,无交叉信号出现,对照的毒株无论是在530μm(FAM),还是610μm(ROX)处,均无荧光信号曲线出现,方法的特异性好;敏感性试验结果显示,该双重荧光定量PCR可检测到100个拷贝的IBRV和BVDV质粒DNA模板;临床样品检测结果表明,对保存在-70℃的127份牛病料样品核酸进行检测,IBRV阳性12份,BVDV阳性26份,IBRV和BVDV同为阳性2份,为混合感染,检测的拷贝数分别为6.24×105和6.32×104拷贝/μL。阳性样品经序列比对分析,分别与IBRV和BVDV的序列100%同源。建立的双重实时荧光定量PCR方法检测IBRV和BVDV具有特异、敏感等优点,可用于临床样品的鉴别检测。     

基于牛呼吸道合胞体病毒F基因TB Green Ⅱ荧光定量PCR检测方法的建立

为了对牛呼吸道合胞体病毒(bovine respiratory syncytial virus, BRSV)进行准确定量检测，针对BRSV F基因设计特异性引物，构建pMD19T-BRSV-gF重组质粒，以其为模板优化反应条件及反应体系，建立TB GreenⅡ荧光定量PCR方法并应用于临床BRSV检测。结果显示，针对BRSV F基因建立的TB GreenⅡ荧光定量PCR方法标准曲线线性关系良好，相关系数为0.995 2;灵敏度高，BRSV最低检测限达3.9×10¹ copies/μL;特异性良好，可特异性检测出BRSV,对牛传染性鼻气管炎病毒和牛病毒性腹泻病毒的扩增呈阴性；重复性好，批内和批间重复性试验变异系数均小于2%。对50份临床样品进行检测，荧光定量PCR对BRSV的阳性检出率(26%)明显优于常规PCR方法(14%)。结果表明针对BRSV F基因建立的TB GreenⅡ荧光定量PCR检测方法适合BRSV的临床检测。     

牛星状病毒、牛病毒性腹泻病毒1型、牛冠状病毒和牛轮状病毒四重实时荧光定量RT-PCR检测方法的建立

利用多重荧光定量RT-PCR （real-time RT-PCR）方法,提高对多病原检测的速度和灵敏度,促进对犊牛腹泻的快速诊断和及时治疗。分别在牛星状病毒（BAstV）ORF2基因,牛病毒性腹泻病毒1型（BVDV-1）5'端非编码区,牛冠状病毒（BCV）N pro基因和牛轮状病毒（BRV）VP6基因的保守基因序列设计、合成并试验筛选了四对有效的特异性引物和探针。进一步利用含4种病毒目的片段的重组质粒,对引物和探针的浓度以及反应条件进行了优化,建立了Real-time RT-PCR标准曲线,并对四重Real-time PCR方法的特异性、敏感性、重复性和各种临床样本的适用性进行了评价。结果显示：Real-time RT-PCR最适退火温度和时间分别为50.0℃和45 s,BAstV、BVDV-1、BCV和BRV的引物浓度分别为300、300、400和500 nmol·L^-1,探针浓度分别为250、150、100和300 nmol·L^-1。对BVDV-1、BCV和BRV的最低检测限均为10²copies·μL^-1,对BAstV的最低检测限为10³ copies·μL^-1,具有良好的特异性和重复性。该方法对临床采集的粪样的阳性检出率高于PCR方法。上述结果表明,建立的四重Real-time RT-PCR方法可以用于犊牛腹泻常见病原BAstV、BVDV-1、BCV和BRV的快速鉴别诊断。     

牛病毒性腹泻病毒重组E2蛋白间接ELISA抗体检测方法的建立与应用

为建立一种简单快速、敏感特异、高通量的牛病毒性腹泻病毒(bovine viral diarrhea virus,BVDV)抗体检测方法,采用原核表达方法对BVDV E2基因中免疫原性强的1段序列进行截短表达,获得了具有良好反应活性的重组E2蛋白,以重组E2蛋白为包被抗原建立了检测BVDV抗体的间接ELISA方法。结果显示:该方法检测牛副流感病毒3型(BPIV-3)、牛轮状病毒(BRV)、牛冠状病毒(BCV)、牛传染性鼻气管炎病毒(IBRV)阳性血清均为阴性,检测BVDV抗体的灵敏度可达1∶12 800,批内和批间重复性试验的变异系数分别小于5%和10%,与中和试验的符合率为94.44%。应用该方法检测国内外5个生产厂家的53批次细胞培养用牛血清样品,阳性污染率达39.62%;检测589份临床牛血清样品,阳性感染率为34.80%。研究表明,建立的BVDV重组E2蛋白间接ELISA抗体检测方法具有良好的特异性、敏感性、重复性和适用性,为BVDV感染的监测提供了重要工具。     

牛传染性鼻气管炎弱毒与牛病毒性腹泻弱毒抗原免疫干扰的研究

本试验使用3~6月龄健康易感牛9头(牛传染性鼻气管炎病毒(IBRV)和牛病毒性腹泻病毒(BVDV)抗原、抗体均阴性),共分3组,每组3头犊牛。第1组首免肌肉注射IBRV-LNM弱毒疫苗株种毒,接种1周后,每头牛接种BVDV-SM弱毒疫苗株;第2组只接种BVDV-SM弱毒疫苗株种毒,接种时间同第1组;第3组为对照组,接种MDBK细胞培养液。接种BVDV-SM疫苗毒后每周采血至疫苗毒接种后28 d,测定接种后BVDV抗体效价,并采用BVDV-JL检验用强毒进行攻毒试验。结果表明,第1组与第2组试验动物血清中牛病毒性腹泻病毒抗体水平无明显差异,能够抵抗BVDV-JL强毒攻击达到免疫保护的效果,说明牛传染性鼻气管炎病毒IBRV-LNM弱毒疫苗株接种后在牛体内对牛病毒性腹泻病毒BVDV-SM疫苗毒不产生免疫干扰作用。     

BPIV-3和BVDV双重RT-PCR快速检测方法的建立

参照GenBank中登录的牛副流感病毒3型(BPIV-3)和牛病毒性腹泻病毒(BVDV)全基因序列,分别针对BPIV3特异性NP蛋白保守基因和BVDV保守区段E2基因设计2对引物,经优化反应条件建立了快速鉴别BPIV-3和BVDV的双重RT-PCR诊断方法。最佳扩增条件为94℃30s,56.2℃30s,72℃1min,循环30次;72℃延伸5min,16℃10min;BVDV引物浓度为1.0μmol/L,BPIV-3引物浓度为0.5μmol/L。采用该方法检测BPIV-3和BVDV参考病毒株,能同时扩增出预期为425bp和294bp大小的特异性片段,而扩增牛传染性鼻气管炎病毒、牛合胞体病毒、猪瘟病毒以及牛支原体、致病性大肠埃希菌、多杀性巴氏杆菌A型、化脓隐秘杆菌和鼠伤寒沙门菌等均呈阴性反应。对参考病毒株进行梯度稀释检测,结果证明该方法检测BPIV-3的灵敏度可达10-3 TCID50/0.1mL,而BVDV的灵敏度达102 TCID50/0.1mL。     

Interactions of Bovine Viral Diarrhoea Virus and Foot-and-mouth Disease Virus with Bovine Reproductive Tissues and Embryos

Contents This review will focus upon the interactions of two important viral pathogens in cattle, bovine viral diarrhoea virus (BVDV) and foot-and-mouth disease virus (FMDV), respectively, with bovine reproductive tissues and embryos. Both viruses are widely spread throughout the world and cause serious economic losses due to death, loss of appetite and weight, respiratory disease, reproductive problems (infertility, early embryonic death, abortions) and decreased milk production (Baker, J Am Vet Med Assoc 190, 1449–1458, 1987; Kitching, J Comp Path 118, 89–108, 1998).     

Spatial patterns of Bovine Corona Virus and Bovine Respiratory Syncytial Virus in the Swedish beef cattle population

Background

Both bovine coronavirus (BCV) and bovine respiratory syncytial virus (BRSV) infections are currently wide-spread in the Swedish dairy cattle population. Surveys of antibody levels in bulk tank milk have shown very high nationwide prevalences of both BCV and BRSV, with large variations between regions. In the Swedish beef cattle population however, no investigations have yet been performed regarding the prevalence and geographical distribution of BCV and BRSV. A cross-sectional serological survey for BCV and BRSV was carried out in Swedish beef cattle to explore any geographical patterns of these infections.

Methods

Blood samples were collected from 2,763 animals located in 2,137 herds and analyzed for presence of antibodies to BCV and BRSV. Moran''s I was calculated to assess spatial autocorrelation, and identification of geographical cluster was performed using spatial scan statistics.

Results

Animals detected positive to BCV or BRSV were predominately located in the central-western and some southern parts of Sweden. Moran''s I indicated global spatial autocorrelation. BCV and BRSV appeared to be spatially related: two areas in southern Sweden (Skaraborg and Skåne) had a significantly higher prevalence of BCV (72.5 and 65.5% respectively); almost the same two areas were identified as being high-prevalence clusters for BRSV (69.2 and 66.8% respectively). An area in south-east Sweden (Kronoberg-Blekinge) had lower prevalences for both infections than expected (23.8 and 20.7% for BCV and BRSV respectively). Another area in middle-west Sweden (Värmland-Dalarna) had also a lower prevalence for BRSV (7.9%). Areas with beef herd density > 10 per 100 km² were found to be at significantly higher risk of being part of high-prevalence clusters.

Conclusion

These results form a basis for further investigations of between-herds dynamics and risk factors for these infections in order to design effective control strategies.     

Concurrent Bovine Virus Diarrhea and Bovine Papular Stomatitis Infection in a Calf

A case of concurrent infection with the viruses of bovine virus diarrhea and papular stomatitis in a calf is reported. The difficulties posed by such situations are described and the criteria used for diagnosis outlined. The two diseases are reviewed briefly and the possible mechanisms whereby bovine virus diarrhea virus is suspected of facilitating infection by other agents are discussed.     

Susceptibility of Bovine Umbilical Cord Endothelial Cells to Bovine Herpesviruses and Pseudocowpox Virus

The purpose of the study was to determine the susceptibility of bovine umbilical cord endothelial (BUE) cells to bovine herpesvirus (BHV) 1, BHV2, BHV4 and BHV5, and to pseudocowpox virus. The detection limits and growth curves of these viruses in BUE cells were compared with those in Vero, Madin-Darby bovine kidney (MDBK), or bovine fetal diploid lung (BFDL) cells. Detection limits were determined by inoculating cell cultures with serial 10-fold dilutions of these viruses, and growth curves by titration of virus, harvested at various times after infecting cells at a multiplicity of infection of 0.1. The detection limits of BHV2 and BHV4 were lower in BUE cells than in Vero or MDBK cells, and cytopathic effects were observed earlier in BUE cells. In addition, BHV2 and BHV4 grew to higher titres in BUE cells than in Vero or MDBK cells. BUE cells appeared to be equally susceptible to BHV5, but less susceptible to BHV1.1 and BHV1.2 than MDBK cells. The study showed that BUE cells are highly susceptible to BHV2 and BHV4, and that the use of BUE cells can improve the laboratory diagnosis of these viruses. The use of BUE cells could also improve the isolation and growth of pseudocowpox virus.     

牛呼吸道合胞体病毒的分离鉴定

从黑龙江省某牛场患有呼吸道疾病的病牛鼻汁中分离到1株病毒,并对其进行了系统鉴定.结果该病毒株能在Vero细胞上增殖并产生特征性的合胞体形态的细胞病变;病毒对5-碘脱氧尿核苷不敏感,对酸、氯仿、乙醚均敏感,不耐热,56℃加热30 min可被灭活,且无血凝性和血吸附特性;该病毒能被牛呼吸道合胞体病毒(BRSV)标准阳性血清中和;应用特异性引物,通过反转录-聚合酶链式反应可从病毒细胞培养物中扩增出BRSV N基因中596 bp的特异性片段,并且分离株与GenBank中BRSV毒株N基因相应片段的核苷酸序列同源性为97.8%～99.3%.以上结果表明所分离到的病毒为牛呼吸道合胞体病毒,命名为BRSV HJ株.