布鲁氏菌弱毒疫苗鉴别技术研究进展

布鲁氏菌病是由布鲁氏菌引起的一种重要的人畜共患传染病,不仅给畜牧业造成严重的经济损失,并威胁人类健康。弱毒疫苗免疫是防控布病的重要手段,但弱毒疫苗的使用往往对布病的诊断和监测造成干扰。各国学者利用细菌学、免疫学、分子生物学等技术手段,建立了病原分离鉴定、补体结合试验、利凡诺尔试验、酶联免疫吸附试验、荧光偏振实验、限制性片段长度多态性、PCR、real-time PCR等多种布鲁氏菌弱毒疫苗鉴别检测方法。研究表明,ELISA和FPT以其高通量以及操作方便的优势,在布鲁氏菌弱毒疫苗与野生菌株感染的血清学鉴别诊断方面前景良好;分子生物学特别是PCR、real-time PCR方法目前仍广泛用于布鲁氏菌纯培养物的鉴定。     

猪瘟强毒与疫苗毒鉴别检测方法的研究进展

猪瘟弱毒疫苗在我国的大规模免疫应用,对预防和控制猪瘟起到了重要作用,但同时使CSFV野毒感染猪和疫苗接种猪的鉴别诊断变得非常困难和必要。本文就猪瘟强毒与疫苗毒的鉴别诊断方法作一综述,以期为猪瘟的诊断与防控提供合理的科学依据。     

伪狂犬病弱毒疫苗与野毒株PCR鉴别诊断方法的建立

目前,在国内用于预防猪伪狂犬病的疫苗主要是基因缺失的弱毒（Ｂａｒｔｈａ－Ｋ６１）为了有效地地区弱毒免疫猪和野毒感染猪,本实验分别建立了一种通用和一种鉴别ＰＣＲ诊断方法,根据已发表的伪狂犬病病毒（ＰｒＶ）ｇＢ,ｇＥ基因的序列,设计并合成了两对引物：ＰＢ１／ＰＢ２和ＰＥ１／ＰＥ２,以疫苗株Ｂａｒｔｈａｋ－６１及野毒株Ｓ,Ｓｕ,Ｆ,Ｌ,Ｙ及闽Ａ（Ｍｉｎ－Ａ）ＤＮＡ为模板进行了ＰＣＲ扩增,结果显示用引物Ｐ     

采用SYBR Green I实时荧光定量RT-PCR方法对猪瘟强毒与疫苗弱毒的鉴别研究

为建立一种能够区分猪瘟病毒(CSFV)强毒与弱毒疫苗C株的SYBR Green Ⅰ荧光定量RT-PCR结合熔解曲线分析方法,本研究对GenBank中登录的25株CSFV强毒株和兔化弱毒疫苗C株全基因组序列进行比较分析,设计一对共用下游引物以及分别针对CSFV强毒株与弱毒疫苗的特异性上游引物,其Tm值分别为84.5±0.5℃和88.5±0.5℃,熔解曲线分析显示为单特异峰.检测结果显示本实验建立的鉴别CSFV强毒感染与弱毒疫苗的荧光定量RT-PCR结合熔解曲线分析方法特异性强,对其他相关病毒无特异性扩增;敏感性高,最低检出量为5×RID50的细胞疫苗基因组拷贝;重复性好;并且扩增效率高、线性范围广、检测时间短,可对免疫猪群中CSFV强毒感染做出快速准确的鉴别检测,为有效防制猪瘟提供依据.     

应用复合多聚酶链反应方法快速鉴别伪狂犬病弱毒疫苗与野毒

本研究根据伪狂犬病病毒（ＰｒＶ）共有ｇＢ和疫苗株缺失的ｇＥ基因序列分别设计合成１对通用（ＰＢ１／ＰＢ２）和１对鉴别引物（ＰＥ１／ＰＥ２）,以在我国广泛使用的疫苗株Ｂａｒｔｈａ－Ｋ６１及从国内外收集的野毒株Ｓ、ＳＵ、Ｆ、Ｌ、Ｙ、Ｍｉｎ－Ａ、Ｓｈｏｐｅ、Ｓ（川）、ＳＬ１、１０＃、ＥＡ（鄂Ａ）ＤＮＡ为模板在同一反应管中同时扩增ｇＢ和ｇＥ基因序列建立了复合多聚酶链反应（ＰＣＲ）方法。ＰＣＲ产物经２．０％琼     

布鲁氏菌病的研究进展

布鲁氏菌病是目前世界上对人畜危害最大的人畜共患病之一,不仅给畜牧业生产造成重大经济损失,也给人的生命安全带来威胁。本文主要结合文献记载对布鲁氏菌病的相关知识进行介绍．以期为有效防控该病提供参考。     

猪细小病毒弱毒冻干疫苗的检测报告

猪细小病毒病是引起母猪繁殖障碍的主要病因之一 ,给养猪业造成严重的经济损失。我所研制成功的猪细小病毒病油乳剂灭活疫苗已被全国各地的养猪场广泛应用 ,取得了良好的社会效益和经济效益。但是随着当今养猪业规模化和集约化的发展 ,仍十分需要猪细小病毒弱毒冻干疫苗 ,而且冻干疫苗拥有保存时间长、运输方便、生产工艺简单、免疫剂量小、成本相对比较低等优点 ,因此课题组又研制了猪细小病毒弱毒冻干疫苗 ,经过实验室的检测 ,取得了令人满意的结果。本文就检测试验结果报道如下 :1　材料和方法1 .1 　猪睾丸 (ＳＴ)传代细胞。ＳＴ细胞的…     

鸡病毒性关节炎弱毒疫苗的研制

将鸡病毒性关节炎病毒鸡胚毒Ｊ－１株适应于鸡胚细胞和Ｖｅｒｏ细胞，经连续传代，通过４０．５℃、３７℃的交替升降培养温度培养，筛选出１株毒力较弱的克隆株，该克隆株蚀斑大小为２．７－３．１ｍｍ，以１０＾５．７２５ＴＣＩＤ５０注射于１日龄敏感雏鸡的足掌皮下和以１０４．７２５－１０＾６．７２５ＴＣＩＤ５０注射于１日龄 敏感雏鸡胸部肌肉内，对雏鸡无致病性，该克隆株在敏感雏鸡内连传３代，无毒力返强现象。这一结果     

鉴别猪伪狂犬病病毒野毒与疫苗毒双重PCR检测方法的建立

依据基因库中的猪伪狂犬病病毒(PRV)基因序列,分别设计了g E和g H两对引物,以PRV闽A株、Bartha(g E-)株和Norden(Tk-)株为模板,筛选最佳反应条件,建立了检测猪伪狂犬病病毒野毒株与疫苗毒株的鉴别PCR方法。该方法能从PRV闽A株、Norden(Tk-)株中扩增出一条355 bp的条带,但Bartha(g E-)株没有扩增出该目的条带。对正常细胞、猪细小病毒(PPV)、猪圆环病毒(PCV)进行检测,结果均为阴性,没有出现交叉反应。在对单项PCR反应条件(引物浓度、Mg~(2+)浓度、退火温度等)优化的基础上,建立了鉴别猪伪狂犬病病毒野毒与疫苗毒的双重PCR检测方法,并分别用双重PCR和单项PCR检测15份临床病料,两者符合率为97.5%,表明该双重PCR检测方法有较高的敏感度,可以用于临床病料的检测。     

猪流行性腹泻病毒野毒株及弱毒疫苗株RT-PCR鉴别检测方法的建立及应用

为建立猪流行性腹泻病毒(PEDV)野毒株及弱毒疫苗株快速鉴别检测方法,根据Gen Bank中公布的PEDV野毒株及弱毒疫苗株的ORF3基因序列,在缺失区的两端设计合成1对特异性扩增引物,用以特异性的扩增PEDV ORF3基因片段,根据目的片段大小判断PEDV的毒株类型;通过退火温度等反应条件优化,建立了区分PEDV野毒株和弱毒疫苗株的RT-PCR鉴别检测方法。结果显示:所建立的RT-PCR鉴别检测方法能特异性区分PEDV野毒株和弱毒疫苗株;PEDV野毒株扩增出234 bp目的片段,PEDV弱毒疫苗株扩增出185 bp目的片段;与猪传染性胃肠炎病毒(TGEV)、A群猪轮状病毒(PRo VA)、猪嵴病毒(PKV)、猪繁殖与呼吸综合征病毒(PRRSV)、伪狂犬病毒(PRV)、猪瘟病毒(CSFV)、猪圆环病毒2型(PCV2)、猪乙型脑炎病毒(JEV)及猪细小病毒(PPV)均无交叉反应;敏感性试验显示,该方法能检测到病毒滴度为1.3×10~3TCID_(50)/mL。利用该方法对采集自广西部分地区93份临床腹泻样品进行检测,临床腹泻样品中PEDV野毒株阳性率为61.29%(57/93),弱毒株阳性率为5.38%(5/93)。结果表明:该RT-PCR鉴别检测方法特异性强、灵敏度高、操作简便,能快速、准确地区分PEDV自然感染野毒株和弱毒疫苗毒株,为猪流行性腹泻的快速诊断及病原分子鉴别检测研究提供了可供借鉴的技术手段。     

Antibody response and antigen-specific gamma-interferon profiles of vaccinated and unvaccinated pregnant sheep experimentally infected with Brucella melitensis

It is well known that the immune response in sheep against Brucella melitensis is subject to individual variation, depending on diverse factors. It bears asking whether these factors (e.g. clinical disease, active infection, state of previous immunity), when affecting a group, can cause variation in the performance of different diagnostic tests. To clarify some of the circumstances in which this immune response can vary, we examine the immune-response profile of sheep protected against the clinical disease by prior vaccination with strain Rev. 1 in comparison with the profile of unprotected females showing the classical brucellosis symptoms. An experimental infection was provoked at midpregnancy under controlled conditions of both non-vaccinated (n=7) and previously Rev.1-vaccinated ewes (n=5). Their immune response was monitored from 7 to 9 weeks before abortion or normal birth to 30 weeks afterwards. Antibody response was assessed by classical tests (Rose Bengal test, complement fixation test (CFT)) in comparison with other diagnostic tests (indirect ELISA (iELISA), competitive ELISA (cELISA), fluorescence polarization assay (FPA), immunocapture test (ICT)). In addition, the cell-mediated immune response was indirectly evaluated by the in vitro antigen-specific release of gamma-interferon. The antibody levels and antigen-specific gamma-IFN profile of the non-vaccinated ewes having the disease and excreting the pathogen was notably high and differed significantly (P<0.05 or P<0.01) from those of vaccinated ewes that neither contracted brucellosis nor excreted the pathogen. In general, all the tests detect the infection in the non-vaccinated ewes with substantial effectiveness. It can be concluded that the high levels of circulating antibodies and of antigen-specific gamma-IFN are related to active Brucella infection. Similarly, the state of protection against the disease, but not necessarily against infection, due to a previous immunization with the Rev. 1 vaccination, appears to be responsible for a low level of detectable immune response. Nevertheless, the design of the study limits conclusions to pregnant ewes and cannot be extrapolated to non-pregnant ewes or rams. Likewise, the study provides no information on animals which are carriers of B. melitensis.     

Performance of skin tests with allergens from B. melitensis B115 and rough B. abortus mutants for diagnosing swine brucellosis

Swine brucellosis by Brucella suis biovar 2 is an emerging disease whose control is based on serological testing and culling. However, current serological tests detect antibodies to the O-polysaccharide (O/PS) moiety of Brucella smooth lipopolysaccharide (S-LPS), and thus lack specificity when infections by Yersinia enterocolitica O:9 and other gram-negative bacteria carrying cross-reacting O/PS occur. The skin test with the protein-rich brucellin extract obtained from rough B. melitensis B115 is assumed to be specific for discriminating these false positive serological reactions (FPSR). However, B115 strain, although unable to synthesize S-LPS, accumulates O/PS internally, which could cause diagnostic problems. Since the brucellin skin test has been seldom used in pigs and FPSR are common in these animals, we assessed its performance using cytosoluble protein extracts obtained from B. abortus rough mutants in manBcore or per genes (critical for O/PS biosynthesis) and B. melitensis B115. The diagnostic sensitivity and specificity were determined in B. suis biovar 2 culture positive and brucellosis free sows, and apparent prevalence in sows of unknown individual bacteriological and serological status belonging to B. suis biovar 2 naturally infected herds. Moreover, the specificity in discriminating brucellosis from FPSR was assessed in brucellosis free boars showing FPSR. The skin test with B. abortus ΔmanBcore and B. melitensis B115 allergens performed similarly, and the former one resulted in 100% specificity when testing animals showing FPSR in indirect ELISA, Rose Bengal and complement fixation serological tests. We conclude that O/PS-free genetically defined mutants represent an appropriate alternative to obtain Brucella protein extracts for diagnosing swine brucellosis.     

鸡新城疫-鸡传染性支气管炎-禽流感-产蛋下降综合征四联灭活油乳剂疫苗的研制与免疫试验

用鸡新城疫La Sota株,鸡传染性支气管炎H120株,产蛋下降综合征127株和禽流感病毒HB1(H9N2)株做为抗原制成油乳剂灭活联苗,并对其进行了物理性状、纯净、安全性、灭活效果、保存期和免疫效力等方面的检验.证明所制备疫苗完全符合质量标准;鸡体对该疫苗4种抗原均产生了良好的免疫应答;攻毒试验证明,免疫鸡能良好地抵抗同种强毒的攻击;所制备疫苗于2～8℃保存12个月后,其免疫效力没有下降.     

Assessment of serological response of young and adult sheep to conjunctival vaccination with Rev-1 vaccine by fluorescence polarization assay (FPA) and other serological tests for B. melitensis

The serological response of young and adult sheep vaccinated conjunctivally with Rev-1 vaccine was assessed by fluorescence polarization assay (FPA), Rose Bengal test (RBT), complement fixation test (CFT), modified Rose Bengal test (m-RBT), indirect ELISA (i-ELISA) and competitive ELISA (c-ELISA), at different post vaccination intervals. One hundred and thirty six adult sheep and 64 lambs were used in the study. The vaccinated animals were bled prior to vaccination (0 day) and thereafter at 21st, 42nd, 35th, 63rd, 91st, 125th, 159th, and 223rd and 330th day post vaccination. The majority of animals (young and adult) showed positive reaction by FPA, RBT, CFT, m-RBT and c-ELISA 21 days post vaccination, whereas by i-ELISA at 42 days. All tests perform equal when animals vaccinated as young are tested 125 days (4 months) post vaccination. In case of animals vaccinated at adulthood, FPA, RBT, CFT and c-ELISA perform equal if the animals are tested 223 days (approximately 8 months) post vaccination. I-ELISA and m-RBT show low specificity if ewes vaccinated at adulthood are tested 330 days (11 months) post vaccination. If control of brucellosis in sheep is based on conjunctivally vaccination of lambs with Rev-1, the vaccinated animals can be tested by any test used for diagnosis of B.melitensis infection accurately at least 4 months post vaccination. If brucellosis control is based on mass vaccination the use of m-RBT and i-ELISA is not recommended for testing adult animals at least for 330 days (11 months) post vaccination due to tests low specificity. Further research is needed so the appropriate cut-offs to be established for FPA, c-ELISA or i-ELISA to become valuable tools for the eradication of Brucella spp. infection in small ruminants in areas where vaccination is practiced.