筛选伊氏锥虫单克隆抗体检测方法的建立—ELISA

首先采用DEAE纤维素柱层析法从感染动物血液中分离获得纯净的伊氏锥虫,通过超声乳化结合离心得到可溶性锥虫抗原,作为免疫接种及检测用:通过免疫大白鼠获得鼠抗伊氏锥虫阳性血清,用辣根过氧化物酶标记羊抗鼠IgG血清获得酶标抗体,经测试,抗原工作浓度为1:80(原浓度为2.57mg/ml),酶标抗体工作浓度为1:400,从而建立了酶联免疫吸附试验(ELISA),作为筛选抗伊氏锥虫单克隆抗体的检测手段。实践证明该方法灵敏度高,特异性强,使用方便。     

兔抗鹅IgG酶标抗体的制备及初步应用

为了研究兔抗鹅IgG酶标抗体的制备,试验采用水稀释-辛酸-硫酸铵法粗提,透析除盐,DEAEA-50纤维素层析相结合的方法提取鹅卵黄IgG,经核酸蛋白检测仪和SDS-PAGE测定IgG浓度;制备兔抗鹅IgG酶标抗体;利用酶标抗体检测小鹅瘟病毒(GPV)VP3基因疫苗的免疫效果。结果表明,粗提的IgG浓度为10 mg/mL,抗体纯度可达到94.5%;免疫扩散得出兔抗鹅 IgG抗血清效价约 1∶32,抗体酶标后效价为1∶3000;酶标抗体可以作为检测疫苗效果一种很好的工具。     

羊伪结核棒状杆菌的分离鉴定及ELISA检测方法的建立

从疑似山羊干酪性淋巴结炎羊的肩前淋巴结脓肿内分离到2株菌,经鉴定均为羊伪结核棒状杆菌。利用羊伪结核棒状杆菌标准菌株(ATCC19410株)制成外毒素作为检测抗原,通过酶标抗体、阳性血清、外毒素抗原最适浓度的选择试验,确定适当的抗原、抗体和酶标抗体稀释浓度,建立了间接ELISA方法用于检测抗体。用建立的ELISA方法检测100份待检羊血清,其中阳性血清4份,阳性检出率为4％。     

牛奶中孕酮直接竞争ELISA检测方法的建立

采用直接竞争ELISA方法检测牛奶中孕酮含量.采用碳化二亚胺法,应用辣根过氧化物酶(HRP)标记11-α羟基孕酮琥珀酸酯(11α-OH-P4-HS),制备孕酮酶标抗原;酶标抗原与牛奶样品中的孕酮共同竞争结合固相包被的孕酮单克隆抗体,建立直接竞争ELISA反应体系.试验结果表明,最佳抗体包被浓度为1∶2 000,最佳酶标抗原工作浓度为1∶16 000,建立的标准曲线为y=-2.4598x+0.999(R2=0.996),牛奶中孕酮检测范围0.12～40 ng/mL,最低检测量为0.12 ng/mL,批内和批间变异系数分别为1.63%和2.49%.成功建立了可用于牛乳中孕酮快速检测的直接竞争ELISA方法.     

检测猪等孢球虫抗体的间接ELISA方法的建立

以纯化的猪等孢球虫孢子化卵囊为抗原,以辣根过氧化物酶(HRP)标记的山羊抗鼠IgG为二抗,建立了检测猪等孢球虫抗体的间接ELISA方法。经检测筛选出最佳反应条件为:2.5μg/孔纯化的猪等孢球虫抗原包被酶标板;抗原最佳包被条件是37℃,2h;酶标二抗的最佳工作浓度为1∶10000;血清、酶标二抗的作用时间分别为30min、45min。     

应用Dot-ELISA检测禽白血病病毒抗原的研究

以鸽抗鸡劳氏肉瘤病毒(RSV)血清IgG作为包被抗体及酶标抗体的双抗体夹心法Dot-ELISA,检测禽白血病病毒抗原,其特异性及敏感性与澳大利亚ELISA(用兔抗AMV-P_(27)血清IgG作为包被抗体及酶标抗体)相同。可用以检测卵清中禽白血病病毒抗原及用鸡胚或鸡胚细胞生产的各种疫苗中污染的禽白血病病毒抗原。     

牛病毒性腹泻-黏膜病病毒斑点酶联免疫吸附检测法的建立

采用辛酸-硫酸铵法提取兔抗BVDV高免血清中的免疫球蛋白IgG,在混合硝酸纤维素膜上进行间接酶联免疫吸附试验,建立了检测BVDV抗原的斑点酶联免疫吸附检测法.结果显示,抗体最佳包被量为400μg/mL,酶标记羊抗兔IgG的最佳工作浓度是1:500倍稀释,抗原最小检出量是5.36μg/mL.应用建立的检测方法对78份腹泻...     

抗阪崎肠杆菌LPS单克隆抗体的制备及初步应用

为制备抗阪崎肠杆菌(ES)脂多糖(LPS)抗原单克隆抗体(MAb)及建立双抗夹心ELISA检测方法,本研究以热灭活的Es(ATCC51329)菌体抗原作为免疫原,ES菌体结合LPS作为筛选抗原,采用杂交瘤细胞技术筛选获得9株稳定分泌抗ES LPS特异性MAb的杂交瘤细胞株.采用改良的过碘酸钠法制备辣根过氧化物酶(HRP)酶标抗体,并建立检测ES的双抗体夹心ELISA方法,该方法对ES ATCC51329具有良好的特异性,最低检测限可达103 cfu/mL,为食品中ES的检测提供特异性MAb及ELISA检测方法.     

抗猪IgG单克隆抗体的制备与应用

采用辛酸一硫酸铵盐析和SuperdexTM-200 凝胶层析分离纯化猪血清IgG,免疫BALB/c小鼠,利用细胞融合技术获得8株稳定分泌抗猪IgG 单克隆抗体的杂交瘤细胞.Ig 亚类分析表明,所制备单克隆抗体的轻链亚类均为K,重链除6H3为IgG2b外,其余7株均属于IgG1.Western blot分析显示,5株单克隆抗体识别猪IgG轻链,3株单克隆抗体识别猪IgG重链.以蛋白G亲和层析纯化单克隆抗体7H1腹水,用改良过碘酸钠法进行辣根过氧化物酶(HRP)标记,结果显示,HRP 标记抗猪IgG单克隆抗体对纯化猪IgG的工作浓度达1:12 800.将HRP标记鼠抗猪IgG单克隆抗体与HRP标记羊抗猪IgG多克隆抗体应用于猪血清圆环病毒抗体检测,二者符合率为95.12%,其ELISA和Westem blot的工作浓度为1:2 000和1:10000,表明HRP标记抗猪IgG单克隆抗体具有高度的敏感性.本研究制备的酶标抗猪IgG单克隆抗体为猪病的免疫诊断试剂研究和猪细胞生物学研究提供了一种基础工具.     

牛病毒性腹泻病毒双抗体夹心ELISA检测方法的建立

将牛病毒性腹泻病毒超免疫血清以常规方法提取IgG，采用过碘酸钠法标记辣根过氧化物酶（HRP），建立了从粪样中检测牛病毒性腹泻病毒抗原的双抗体夹心ELISA。结果，抗体的最佳包被量为150μg／mL，酶标抗体最适工作浓度为1：200；封闭液为50mL／L的兔血清；待检粪样及酶标抗体的感作时间为37℃ 120min；底物显色时间为室温15min。应用建立的检测方法对河北省8个大中型奶牛场298份乳牛腹泻粪样进行了检测，结果，阳性检出率为42．6％。     

重组PEA受体结合区蛋白的免疫活性

为了观察重组绿脓杆菌外毒素 A(PEA)受体结合区蛋白在不同动物体内的免疫效果 ,将该蛋白纯化后免疫了小鼠、家兔、山羊等动物。对小鼠进行了攻毒实验 ,通过 EL ISA方法检测了家兔、山羊血清中抗体的消长规律。结果对小鼠的保护情况为 :最后 1次免疫后 14 d小鼠对 3倍 L D50 的 PEA攻毒保护率为 10 0 % ,2 1d保护率为 5 0 % ,2 8d后无保护效果。家兔和山羊免疫后 7～ 14 d达到峰值 ,2 1d后逐渐降低 ,2 8～ 35 d后降至免疫前水平     

羊附红细胞体双抗体夹心ELISA诊断方法的建立

为快速准确诊断和检测羊附红细胞体病,及时采取防治措施,建立了检测羊附红细胞体抗原的双抗夹心ELISA诊断方法。选取规模化养殖场羊,镜检附红细胞体红细胞感染率> 90%,无菌采取血液,分离羊附红细胞体抗原,制备纯化兔抗羊附红细胞体抗体,应用辣根过氧化物酶标记抗体,进行双抗体夹心ELISA试验。试验结果表明,双抗体夹心ELISA方法的最佳工作条件为:抗体最佳包被量为82.91 μg/mL,酶标抗体最适工作浓度为1∶400,抗原最低检出量为7.81 μg/mL;而且与支原体、大肠杆菌、葡萄球菌以及牛、猪、兔附红细胞体均不出现交叉反应,表明该方法具有良好的特异性,可用于羊附红细胞体病的诊断和群体检测。     

传染性支气管炎病毒抗体间接ELISA检测方法的建立

为了快速检测针对传染性支气管炎病毒(IBV)抗体,本研究建立相应的间接ELISA(iELISA)检测方法。以本实验室分离的临床毒株DS10为检测抗原,经过差速离心纯化获得DS10病毒作为包被抗原,利用方阵试验,优化一系列条件,最终确定了最佳的ELISA反应条件。抗原最佳包被浓度为0.11mg/mL,血清最适稀释度为1:100,封闭液为含1%BSA的PBST,封闭时间为60min,一抗作用时间90min,HRP标记的兔抗鸡IgG稀释倍数为1:3500,作用时间为60min,显色时间为10min。用iELISA方法和血凝抑制试验(HI)同时检测145份血清样品的结果表明,建立的iELISA方法与常规的HI检测的符合率为92.41%,iELISA和HI的阳性检出率分别为92.41%和90.34%,iELISA的敏感性略优于HI。     

Activation of the resident microbial flora as a possibility for the improvement of humoral antibody potentials]

The effect of a parenteral application of an adjuvant (Propionibacterium acnes) and an adjuvant/antigen combination (Staphylococcus aureus Cowan I/Al(OH)3, Pseudomonas aeruginosa/Al(OH)3 respectively, was tested with regard to the improvement of antibacterial resistance. Parameter was the humoral antibody production (IgG) of rabbits against six facultative pathogen bacterial species (St. aureus, Sc. faecium, Bac. cereus, P. multocida, E. coli, Ps. aeruginosa) and against sheep rod blood cell membranes. The three methods of treatment led to a significant enhancement of IgG-antibodies against the particular homologous antigen. In addition to this specific reaction the application of adjuvant/antigen combinations provoked a significant enhancement of antibodies also against heterologous antigens (P. multocida, Bac. cereus, sheep red blood cell membranes). The application of P. acnes had no distinct effect on the antibody titer against the different antigen preparations. In order to analyse the immune response qualitatively, a greater part of serum samples was examined by immuno blot technique. The number of partial antigens recognized by the sera increased during the experiments but the rise did generally not relate to developments of antibody titers. Nevertheless, the Ps. aeruginosa/Al(OH)3-treatment seemed to improve the ability of sera to detect antigenic determinants of heterologous bacterial species.     

Enzyme-linked immunosorbent assay for detection of antibody to Pseudomonas aeruginosa and measurement of antibody titer in horse serum

Enzyme-linked immunosorbent assay (ELISA) was used for detection of immunoglobulin (Ig) M and IgG antibodies against a serologically common antigen (original endotoxin protein), protease, and elastase of Pseudomonas aeruginosa. The P aeruginosa antibody in horse sera was measured, using ELISA. Horseradish peroxidase-labeled rabbit anti-horse IgM and IgG antibodies were used for enzyme-labeled antibody conjugate. 5-Aminosalicylic acid and H2O2 were used for substrate. Sera collected from a vaccinated horse, a newborn foal, and 72 healthy racehorses were investigated for antibodies against P aeruginosa by ELISA and passive hemagglutination procedure. Changes in IgM and IgG antibody titers with vaccination were clear by ELISA. In the newborn foal, significant amounts of IgM and IgG antibodies from colostrum were present on the 1st day after birth. It was shown by ELISA that the level of antibodies in the newborn decreased initially and then increased. Some antibodies against original endotoxin protein, protease, and elastase of P aeruginosa were detected in almost all the healthy racehorses investigated.     

A monoclonal antibody capture ELISA to detect antibody to border disease virus in sheep serum.

An enzyme-linked immunosorbent assay (ELISA) has been developed to detect antibody to border disease virus (BDV) in sheep serum. A monoclonal antibody bound to 96-well microplates was used to capture antigen from detergent-solubilised BDV-infected cells. Single dilutions of test sera were then added to wells containing bound BDV antigen and control wells containing uninfected cell lysates. Specific antibody to BDV was detected by an anti-ovine IgG antiserum conjugated with horseradish peroxidase and the results expressed as ELISA units with reference to a standard curve. Sequential sera from 16 experimentally infected sheep and single sera from 103 sheep involved in a field outbreak were tested in the ELISA and for neutralising antibody. There was good qualitative correlation between the two tests.     

犬细粒棘球绦虫粪抗原夹心ELISA检测方法的建立

为建立特异性和敏感性高的检验犬细粒棘球绦虫感染的方法。用细粒棘球绦虫(简称,Eg)成虫抗原分别免疫兔和绵羊,收集高免血清,纯化的高免抗体。依据抗体夹心ELISA工作原理,以兔抗体包被,检测感染Eg、不同犬带科绦虫的实验犬和空白犬粪样,绵羊抗体扑捉抗原,HRP标记兔抗绵羊IgG(1∶8 000)催化显色,用酶标仪测定OD 405nm吸光度,用以确定其特异性和敏感性。试验结果表明,敏感性为82.69%(43/52),特异性为85.88%(140/163);粪抗原在感染细粒棘球绦虫16d后可检出,最低抗原浓度为9.7ng/mL即犬感染5条成虫时可检测出阳性。该检测方法具有较好的特异性和灵敏性,为进一步研制检测细粒棘球绦虫虫体抗原ELISA检测试剂盒奠定了基础。     

Development and validation of an ELISA to detect antibodies to Corynebacterium pseudotuberculosis in ovine sera

Several enzyme-linked immunosorbent assays (ELISAs) have been developed for the detection of antibodies to Corynebacterium pseudotuberculosis, the causative agent of caseous lymphadenitis (CLA). However, none are commercially available in the UK. It was therefore necessary to develop a new, economic ELISA for use in a research project studying the epidemiology of CLA in UK sheep. The ELISA with its diagnostic qualities is presented. The ELISA was developed using sonicated C. pseudotuberculosis and optimised to detect total antibody or IgG class antibody in serum. Receiver operating characteristic (ROC) curves were obtained and the area under the ROC curve was used to compare the sensitivity and specificity of the two ELISAs. Both versions of the ELISA were evaluated on a panel of 150 positive reference sera and 103 negative reference sera. Using the test at 100% specificity, the sensitivity of detection of total antibody was 71% (95% confidence interval 63-78%), and the sensitivity of detection of IgG antibody to C. pseudotuberculosis was 83% (76-89%), which compares favourably with other reported ELISA tests for CLA in sheep. The sensitivity of the IgG antibody assay may be higher because of the greater affinity of IgG class antibodies compared with the IgM antibodies also detected by the total antibody ELISA. The results of ROC analysis indicated that the IgG isotype ELISA was more accurate than the total antibody ELISA. The efficiency of the test was greatest when serum samples were run in a dilution series than when any single serum dilution was used. The ELISA is considered to be suitable for application in field studies of CLA in UK sheep.     

基于大片吸虫分泌排泄产物层析组分的牛片形吸虫病间接ELISA诊断方法的建立

为建立更敏感、特异的牛片形吸虫病早期诊断方法,本试验将收集的大片吸虫分泌排泄产物（Fasciola gigantica excretory-secretory products,FgESP）进行凝胶过滤层析并从中筛选出检测效果最优的UV280吸收峰,从此峰对应的组分中筛选出诊断效果最优的层析组分后将其作为抗原,通过棋盘滴定试验优化抗原包被浓度、血清稀释度、酶标二抗稀释度、显色时间等,确定临界值,建立牛片形吸虫病间接ELISA诊断方法。对建立的方法进行敏感性和特异性试验,检测试验感染0~14周的水牛血清和临床160份水牛血清样本,并与已有的诊断抗原FgESP（阴阳临界值为0.320）进行诊断效果比较。结果显示,层析组分F22具有较优的检测效果。间接ELISA的最佳反应条件为：F22抗原包被浓度0.157 μg/mL,待测血清与酶标二抗的稀释度分别为1：400和1：40 000,显色时间为25 min。应用建立的方法检测15份水牛阴性血清,确定D_{450 nm}阴阳性临界值为0.408。比较F22与FgESP发现,二者特异性相似,但F22作为抗原的敏感性高于FgESP。检测试验感染大片吸虫的水牛0~14周血清,结果表明,从感染第2周开始F22-IgG水平极显著高于FgESP-IgG水平（P<0.01）,因此,F22比FgESP诊断效果更优。对160份水牛血清检测发现,F22阳性检出率为71.25%,FgESP阳性检出率为63.75%。上述结果表明,相比于FgESP,以F22作为诊断抗原建立的大片吸虫病间接ELISA诊断方法敏感性更高,可更有效地进行牛大片吸虫病的早期诊断。     

Comparison of the Q-fever complement fixation test and two commercial enzyme-linked immunosorbent assays for the detection of serum antibodies against Coxiella burnetii (Q-fever) in ruminants: Recommendations for use of serological tests on imported animals in New Zealand

Abstract

AIM: To make valid recommendations on the use of serological test methods for the detection of serum antibodies in ruminants against Coxiella burnetii (Q-fever), by comparing the performance of the complement fixation test (CFT) and two ELISA, and by identifying reasons for discrepancies between the test methods.

METHODS: A total of 73 serum samples from infected cattle, 69 from infected goats, and 100 samples from non-infected cattle and 57 samples from non-infected sheep, as well as 95 samples from infected cattle herds (mix of seropositive and seronegative samples), were tested using the CFT, the IDEXX ELISA (I-ELISA) and the Pourquier ELISA (P-ELISA). A mixed panel of 12 serum samples from sheep from inter-laboratory proficiency testing (proficiency panel) was also tested using the CFT and both ELISA, and further investigated using IgG- and IgM-specific ELISA.

RESULTS: Generally, the two commercial ELISA were more sensitive than the CFT for the detection of infected ruminants. Good agreement between ELISA for positive and negative results was found for samples from the infected herd, while results for the positive panels varied between the two ELISA. For the total of the positive serum panels, the I-ELISA detected 95% of samples as positive or suspicious, while the P-ELISA detected only 81%. In the P-ELISA, more samples were considered suspicious (18%) than in the I-ELISA (14%). All sera from noninfected sheep and cattle tested negative in the serological test methods employed, except for one positive sample from a sheep in the P-ELISA. Further investigation revealed that a CFT-positive but ELISA-negative result was due to high IgM and low IgG reactivity.

CONCLUSIONS: The two commercial ELISA were more sensitive than the CFT in all panels from infected ruminants. However, they could only detect IgG. The I-ELISA should be the serological test method of choice for cattle, sheep and goats for import testing of animals into New Zealand because it was more sensitive than the P-ELISA and was equally specific to the PELISA and the CFT. For other animal species, such as deer and camelids, the CFT should still be used since none of the ELISA has been evaluated for these species. This study has shown that the two commercial ELISA will detect the majority of infected ruminants but may miss animals that have not developed an IgG response.