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1.
本研究的目的是探索副结核分枝杆菌特异性蛋白MAP0862在牛副结核病血清学诊断中的作用,建立牛副结核病特异性ELISA诊断方法。将通过原核表达获得的副结核特异性蛋白MAP0862纯化并定量后作为包被抗原,经过一系列条件优化后初步建立了牛副结核病间接ELISA诊断方法。使用牛副结核阳性血清、牛布病阳性血清、牛结核阳性血清、卡介苗免疫牛血清、牛大肠杆菌阳性血清以及健康阴性牛血清对该方法的验证表明其具有良好的特异性。使用该方法对300份临床血清进行检测,结果表明该方法与IDEXX副结核检测试剂盒的符合率为94.3%。基于副结核特异性蛋白质MAP0862建立的间接ELISA诊断方法能有效检测牛副结核病。  相似文献   

2.
吉林省兽医科学研究所(以下简称省兽研)研制的牛副结核病补体结合反应抗原[以下简称牛副结核补反抗原]。经实验室研制,野外  相似文献   

3.
采用ELISA检测方法对内蒙古地区17个奶牛场的2 391头奶牛进行牛副结核血清学检测。结果表明,大型奶牛场副结核的血清阳性率较低,在0~5%之间;小型奶牛场的副结核血清阳性率较高,平均阳性率为14.1%。调查结果提示,内蒙古地区奶牛场存在牛副结核病的流行,对该病的防控工作应给予高度重视。  相似文献   

4.
建立了检测牛血清中副结核分枝杆菌的特异抗体的酶联免疫吸附试验(ELISA),在试验过程中探索出一种可以避免在 ELISA 检测副结核分枝杆菌原生质抗原的抗体时,经常遇到的假阳性反应的方法。被检血清来源于副结核分枝杆菌、牛型结核分枝杆菌。堪萨斯分枝杆菌或星形诺卡氏菌感染的牛,经细菌学检查为阴性而副结核补体结合反应阳性及用假结核分枝杆菌感染的羊。预先使用草分枝杆菌吸收后的试验血清,基本上可以消除掉假阳性反应。凡经过这种方法处理的血清,不会影响副结核病牛的 ELISA 抗体水平。试验结果表明预先用草分枝杆菌吸收的血清,可以消除在 ELISA 诊断牛副结核病  相似文献   

5.
以亲和层析法提取副结核特异性抗原,用以作牛副结核ELISA的检测。结果证明,本抗原的特异性优于Sephadex-G200凝胶柱第一蛋白峰抗原。  相似文献   

6.
在前一报告中,采用副结核菌原生质抗原进行ELISA捡测牛副结核抗体时,由于副结核分枝杆菌与其他许多分支杆菌具有类属的抗原性,因此常出现假阳性反应而干扰对副结核抗体的检测。为此,我们参考Y. Yokomizo的方法,利用草分枝杆菌对待检血  相似文献   

7.
补体结合反应(以下简称补反)在兽医实践中,对于牛肺疫、布氏杆菌病、牛副结核、马传染性贫血等病的诊断有较大的实用价值。在血清学反应中,补反的操作方法是比较复杂的。一些文献和农牧渔业部公布的《动物检疫操作规程》指出:“每次做补反正式试验前都要当日测定补体效价,否则由于使用补体量不准而影响试验结果。”我们  相似文献   

8.
为探索副结核特异性蛋白MAP0862与MAP1345在牛副结核病血清学诊断中的作用,将通过串联表达获得的融合蛋白MAP0862-1345纯化定量后包被酶标板,经过对反应条件的优化,初步建立了基于融合蛋白MAP0862-1345的间接ELISA诊断方法。使用建立的ELISA方法对牛副结核病阳性血清、牛结核病阳性血清、牛布病阳性血清、卡介苗免疫牛血清、健康牛血清检测的结果表明其具有较好的特异性;使用该方法与IDEXX副结核病抗体检测试剂盒共同对300份临床血清样本检测,总符合率为92.7%。  相似文献   

9.
牛副结核分枝杆菌实时荧光定量 PCR 检测方法的建立   总被引：1，自引：1，他引：0  
根据GenBank上公布的牛副结核分枝杆菌C-2染色体的ISMav2基因保守区域序列设计合成1对特异性引物,建立了一套SYBR GreenⅠ荧光定量PCR检测牛副结核分枝杆菌(Mycobacterium paratuberculosis)的方法。以实验室构建的牛副结核分枝杆菌pMD-ISMav2阳性重组质粒为标准品,通过优化反应条件,建立了标准曲线,其相关系数为0.999。以构建的标准品为模板,进行了特异性和敏感性试验。结果显示,该方法检测布氏杆菌、大肠杆菌、沙门氏菌、链球菌DNA均为阴性;最低可检测到相当于每微升1.96×101拷贝数的标准品阳性质粒。本研究建立的实时荧光定量PCR具有特异、敏感和快速等优点,可用于牛副结核杆菌病的监测。  相似文献   

10.
原核表达纯化牛副结核分枝杆菌MAP3290-1595蛋白,为检测牛副结核分枝杆菌提供了新的材料。笔者通过基因串联融合MAP3290和MAP1595基因,获得MAP3290-1595基因,并使用DNAMAN软件对MAP3290-1595基因序列进行分析;构建重组质粒pET30aMAP3290-1595,将其转化至E.coli BL21(DE3)感受态细胞中,使用IPTG诱导目的蛋白表达;使用亲和层析法对目的蛋白进行亲和纯化,从而获得MAP3290-1595蛋白;利用Western Blot方法对该蛋白进行质检。成功表达纯化出MAP3290-1595蛋白。该蛋白大小为43 k Da,浓度为0.430 mg/mL,纯度大于90%。本试验成功获得MAP3290-1595蛋白,利用Western Blot和间接ELISA法检测该蛋白的反应原性,与牛副结核阴性血清反应良好,得出该蛋白具有良好的反应原性,为建立牛副结核分支杆菌检测方法提供材料。  相似文献   

11.
An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of antibodies to Mycobacterium paratuberculosis in the sera of cattle. This assay was designed to minimize the nonspecific ELISA reactions caused by immunoglobulin (Ig)M by measuring only IgG1 antibodies against a protoplasmic antigen from the organism. The ELISA detected IgG1 antibodies in the sera of 58% of cattle with positive fecal cultures for M paratuberculosis compared with detection of 45% of culture-positive animals with an immunodiffusion test. In addition to its sensitivity, the ELISA apparently is highly specific because only 4% of the sera from fecal culture-negative animals gave a false-positive result.  相似文献   

12.
Three serological assays were compared for detection of antibodies to bovine herpes-virus type 1. These were virus neutralization (VN), enhanced complement fixation (CF) and enzyme-linked immunosorbent assay (ELISA). The ELISA was developed using an infected cell lysate antigen and purified virus and was optimized in relation to antigen and antisera dilutions. The CF assay was enhanced by the addition of bovine complement. These 3 assays were compared for detection of: specific virus antibody titers; sero-conversions; early antibody response in experimentally-infected cattle. Both ELISA end-point titers and single dilution values were found to be more sensitive than the CF or VN assays for specific antibody level quantitation. With a single dilution ELISA test procedure a correlation was obtained between ELISA values and VN titers. Using the single dilution ELISA test the assay also detected antibodies in experimentally-infected cattle before either the VN or CF assays, and agreed with the VN test in 35/38 seroconversions found by 4-fold or more VN changes between acute and convalescent paired sera from naturally-infected animals. The single dilution ELISA was a rapid and sensitive test for routine antibody detection in bovine sera.  相似文献   

13.
OBJECTIVE: To determine the specificity of serological tests that are currently used in veterinary diagnostic laboratories in Australia for detection of Mycobacterium avium subsp paratuberculosis infection in goats. DESIGN: A laboratory study. PROCEDURE: Four tests were studied, comprising AGID with M. a. paratuberculosis antigen derived from cattle isolates of caprine or bovine origin, the EMAI caprine Johne's disease absorbed ELISA and the CSL PARACHEK Johne's absorbed EIA. The specificities of AGID and ELISA for paratuberculosis (Johne's disease) were estimated after examining a panel of 1000 serum samples collected from goats in Western Australia, a region free of paratuberculosis. In addition a comparison was made of test performance in a small number of paratuberculous goats from New South Wales using sera from two archival collections. RESULTS: The specificity of the AGID tests was 100% while the specificities of the two absorbed ELISA were 99.7 to 99.8% at appropriate positive-negative cut-offs. Based on testing the small sample of sera from infected goats, the absorbed ELISA tests detected about twice as many goats with Johne's disease as the AGID. Each test detected paratuberculous animals regardless of whether infection was caused by cattle or sheep strains of M. a. paratuberculosis. CONCLUSIONS: Both ELISA and AGID tests for paratuberculosis have high specificity and can be used in a market assurance program without risk of generating large proportions of false positive test results. However, the results suggested the ELISA is more sensitive for detection of infected goats and should be used in preference to the AGID. The two formats of ELISA evaluated in this study have similar characteristics and could be used in paratuberculosis control programs for the goat industries, but further data on sensitivity would increase confidence in their application.  相似文献   

14.
An enzyme-linked immunosorbent assay (ELISA) was evaluated and compared in parallel with the standard complement fixation test (CFT) for the diagnosis of bovine subclinical paratuberculosis. Bovine sera preabsorbed with the mixture of Mycobacterium phlei and kaolin suspension were assayed for antibody activities to the crude protoplasmic antigen of Mycobacterium paratuberculosis in the ELISA. ELISA antibody titer was expressed as ELISA antibody index (EAI) value: EAI = (At-An)/(Ap-An), where At, Ap and An are the absorbance values of a 1:200 dilution of unknown test sera, a 1:400 dilution of positive control serum, and a 1:200 dilution of negative control serum. An EAI of 0.6 or greater was established as a reasonable cutoff point for a positive antibody titer by ELISA. Of the 156 sera from cattle with subclinical M. paratuberculosis-infection, 106 (67.9%) were positive by ELISA and 41 (26.3%) by CFT. Of the 3,880 sera from cattle in the herds which had no history or evidence of paratuberculosis, 3,875 (99.9%) were negative by ELISA, and 3,787 (97.6%) by CFT. Positive ELISA titers were detectable 1 to 5 months earlier than positive CFT titers in experimentally infected cattle, and 7 to 10 months earlier in naturally infected cattle. These results indicate that the ELISA should replace the CFT as the routine test of choice for the diagnosis of bovine paratuberculosis.  相似文献   

15.
An antigen was isolated from the protoplasm of Mycobacterium paratuberculosis by a combination of gel filtration, ion exchange, and affinity chromatography. The purified antigen constituted 7.8% of the total protein in the protoplasm. The specificity and sensitivity of the enzyme-linked immunosorbent assay (ELISA) for paratuberculosis, using the purified antigen, were evaluated with sera from 104 cattle which were examined (surveyed) for M paratuberculosis infection by fecal cultural technique. The ELISA was positive in 50 of 60 infected animals. Five of 44 noninfected animals were also test-positive. When a crude protoplasmic extract was used as antigen in the ELISA, sera from 37 infected and from 18 noninfected animals were test-positive. Cross-reactions were encountered in both complement-fixation test and the ELISA between crude or partially purified M paratuberculosis antigens and antisera to Nocardia asteroides, M avium, M phlei, and M fortuitum. The purified antigen gave no complement-fixation reaction with any of these antisera. In the ELISA, cross-reaction was not found when purified antigen was used and the sera were screened at 1:40 dilution.  相似文献   

16.
A dot ELISA was developed for detection of antibodies to Mycobacterium paratuberculosis. The assay was evaluated by testing sera from cattle that were determined, by bacteriologic culturing of feces, to be infected with M paratuberculosis and were suspected of having clinical disease. Further evaluation involved testing sera from cattle in which M paratuberculosis had not been isolated from feces on several attempts. Results of the dot ELISA were positive for sera from 86 of 101 infected cattle, and results were negative for sera from 64 of 64 noninfected cattle. Results of conventional ELISA and agar gel immunodiffusion (AGID) tests were positive for 79 of 99 and for 51 of 101 infected cattle, respectively. The dot ELISA also was evaluated by comparing results of testing 708 sera with results of bacteriologic culturing of matched fecal samples from 262 cattle in 3 central Ohio dairy herds known to include cattle infected with M paratuberculosis. Results of the dot ELISA were positive for 25 of 39 sera from cattle with positive results on culturing of concurrently obtained fecal specimens. The dot ELISA results were negative for 661 of 669 sera from cattle with negative results to culturing of concurrently obtained fecal specimens. The 39 sera from cattle with positive results on bacteriologic culturing of matched fecal specimens had positive results for ELISA and the AGID test 25 and 14 times, respectively. The 669 sera from cattle with concurrently negative results on bacteriologic culturing of feces had negative results to ELISA and the AGID test 559 and 668 times, respectively.  相似文献   

17.
Three hundred and forty-one sera from cattle in Western Australia and 106 sera from Mycobacterium paratuberculosis faecal culture positive cattle were used to evaluate the performance of two absorbed enzyme-linked immunosorbent assays (ELISA) (one locally produced, the other a commercial test) and a complement fixation test (CFT) for the detection of Johne's disease in cattle. The diagnostic sensitivity (47.2%) of the local ELISA was significantly higher than that of the commercial ELISA (31.1%), and significantly higher than that for the complement fixation test (17.9%) and immunoblot (20.8%). Diagnostic specificity for the two ELISAs was 99.7% and 97.9% and similar for CFT and immunoblot (97.1% and 97.7%, respectively). The diagnostic sensitivity rose for both ELISAs and the CFT as the number of M. paratuberculosis isolated from the faeces increased. The ELISA antigen was characterised by polyacrylamide gel electrophoresis and electrophoretic immunoblotting and was found to consist mostly of a carbohydrate-type macromolecule of 32-42 kDa. This macromolecule was identified as lipoarabinomannan (LAM) by using a LAM-specific monoclonal antibody in immunoblots and purified LAM in absorption experiments. By applying more complex antigen preparations in immunoblots, serum antibodies against proteins of 47, 37, 30, 24 and 21 kDa, and against the 32-42 kDa carbohydrate component were frequently found in infected cattle, and of these the 47 kDa protein and the 32-42 kDa antigen were immuno-dominant. Pre-absorption of the sera with M. phlei sonicate indicated that the protein antigens contributed markedly to non-specific serological cross-reactions, while the 32-42 kDa non-protein macromolecule appeared to be specific.  相似文献   

18.
Fifty dairy herds in Alberta were tested for the presence of Mycobacterium paratuberculosis by fecal culture and serum enzyme linked immunosorbent assay (ELISA). Individual sera (1500) were tested for antibodies to M. paratuberculosis by ELISA. Fecal samples were combined in pools of 3 (10 pools/herd) for a total of 500 pools that were cultured for M. paratuberculosis. Thirty cultures, including all 10 pools from 1 herd, were not readable due to fungal contamination. The remaining 470 cultures, representing 49 herds, yielded 16 positive pools (3.4% +/- 2.1%) from 10 herds (20.4% +/- 11.3%). The ELISA of each of the 1500 sera detected 105 (7.0% +/- 2.4%) positive sera and 20 (40.0% +/- 13.6%) positive herds, based on 2 or more individual positive sera in the herd. The true herd-level prevalence, as determined by ELISA, was 26.8% +/- 9.6%. The true herd-level prevalence, as determined by M. paratuberculosis fecal culture, ranged from 27.6% +/- 6.5% to 57.1% +/- 8.3%, depending on whether 1, 2, or all 3 individual fecal samples in the positive fecal pool were culture positive.  相似文献   

19.
An enzyme-linked immunosorbent assay (ELISA) was developed and used to detect antibodies to Mycobacterium paratuberculosis in serum samples obtained in December of 1983 from 954 hunter-killed white-tailed deer (Odocoileus virginianus) in 13 Ohio counties. Positive or negative status was determined by calculating a signal-to-noise ratio, a ratio between the optical density of the test serum and negative reference sera; a ratio of greater than or equal to 3.0 was considered positive. Twenty-four samples (2.5%) were found to be assay positive, using this method. A statistically significant difference among age groups was found, with those less than or equal to 6 months of age having a lower proportion of positives. Differences by sex were not observed. To determine the validity of the ELISA in deer, serum samples from 46 fallow (Dama dama) and axis deer (Axis axis) harvested from a known infected population were tested by ELISA and agar-gel immunodiffusion. The agar-gel immunodiffusion test showed evidence of exposure of the deer to M paratuberculosis or a related antigen. The ELISA closely approximated the prevalence of paratuberculosis infection as previously determined by fecal culture in this population. As a result of these tests, it was concluded that free-ranging Ohio deer have been infected with M paratuberculosis or exposed to a closely related antigen.  相似文献   

20.
To facilitate the control of enzootic pneumonia (EP) of swine caused by Mycoplasma hyopneumoniae, the complement fixation (CF) test has been used for the detection of M. hyopneumoniae antibodies. However, the CF test is a cumbersome and time-consuming technique and cross-reactivity are major drawbacks associated with this method. To circumvent these drawbacks, we have developed a double-sandwich enzyme-linked immunosorbent assay (ELISA), consisting of purified monoclonal antibody (Mab) against the 46 kDa surface antigen (P46) of M. hyopneumoniae and recombinant P46 protein expressed in Escherichia coli, for the detection of antibodies to M. hyopneumoniae in serum samples from pigs experimentally inoculated with M. hyopneumoniae and from naturally infected pigs, and compared the practical usefulness of ELISA using the CF test. In experimentally inoculated pigs, the CF and ELISA antibodies were detected at almost the same time, and a good correlation was demonstrated between the CF test and the ELISA. In a survey conducted on field samples, the seropositivity by ELISA in pigs of age 2-6 months was increased. At the time of slaughter, approximately 80% of the animals were seropositive for ELISA. However, a gradual decrease in the prevalence of ELISA positive samples was observed in sows with increasing parity. No correlation was seen between the results obtained with the two methods in the clinical samples. The CF test appears to have limited value for the diagnosis of EP in conventional herds because nonspecific reactions were frequently observed. Therefore, this ELISA is a useful alternative to the CF test currently used for the diagnosis of EP.  相似文献   

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