牛布鲁氏菌四种血清学检测方法的比较

[目的 ]为在布鲁氏菌病临床检疫中选择可靠的血清学检测方法提供参考。[方法 ]对采集的294份牛血清样品用虎红平板凝集试验(RBT)、试管凝集试验(SAT)、酶联免疫吸附试验(ELISA)和补体结合试验(CFT)进行布鲁氏菌病抗体检测,比较RBT与ELISA,SAT与CFT的符合率及Kappa值,以CFT作为判定标准,比较四种检测方法的敏感性和特异性。[结果 ]RBT与ELISA、SAT与CFT检测方法的符合率高达到95%以上,且Kappa值均大于0.75。以CFT作为判定标准,RBT和ELISA的敏感性较好,但有假阳性;SAT的特异性较好,但有假阴性。综合比较认为ELISA的敏感性和特异性都比较理想。[结论 ]临床工作中使用RBT或ELISA对布鲁氏菌病进行初筛,用CFT进行复核确诊,通过两种或两种以上的血清学检测方法联合诊断,结果较为理想。     

不同布鲁氏菌血清学方法检测牛羊血清抗体的比对

为评价不同布鲁氏菌血清学方法检测牛羊血清的性能,采用试管凝集试验(SAT)、竞争酶联免疫吸附试验(c ELISA)、荧光偏振试验(FPA)3种常规血清学检测方法,对已知感染情况的牛羊血清进行布鲁氏菌抗体检测,比较这3种方法的一致性、敏感性与特异性。结果显示:SAT检测牛血清的Kappa值小于0.75,一致性一般;cELISA、FPA检测牛羊血清的Kappa值均大于0.75,一致性较好。SAT特异性较高,假阳性率均为0,但敏感性较低,假阴性率较高;cELISA敏感性和特异性较为理想,均在92%以上;FPA敏感性最好,为100%,特异性也较高,达97%以上。结果表明,SAT特异性高,但敏感性略低,c ELISA和FPA敏感性、一致性和特异性均较好。结果提示,在实际诊断中,先用操作简便的SAT进行筛选,再用操作较为复杂、需要特定仪器、特异性高的cELISA和FPA进行复核较为理想。     

牛皮蝇蛆病间接ELISA诊断方法的建立

以纹皮蝇Ⅰ期幼虫粗提蛋白为包被抗原,通过方阵试验确定了血清最佳稀释倍数为80倍,抗原最佳包被浓度为26.64μg/mL,并对其特异性、敏感性和重复性进行了试验,建立了牛皮蝇蛆病间接ELSIA诊断方法。再以建立的ELISA诊断方法对采自内蒙古地区的233份牛血清进行了检测。结果表明,所建立的牛皮蝇蛆病间接ELISA诊断方法具有较好的特异性、敏感性和可重复性,可用于牛皮蝇蛆病的血清学检测。     

山羊布鲁氏菌病不同血清学检测方法的比较

为比较山羊布鲁氏菌病不同血清学检测方法,继而为山羊布鲁氏菌病的临床检测提供参考,对采集到的423份血清样品分别用虎红平板凝集试验(RBT)、试管凝集试验(SAT)和竞争酶联免疫吸附试验(c ELISA)3种方法进行检测,比较3种方法的一致性、敏感性和特异性。结果表明:RBT和SAT、cELISA和RBT、c ELISA和SAT的Kappa值均大于0.75,一致性较好;RBT和SAT符合率最高,RBT敏感性最好,cELISA特异性最好。因而建议在开展山羊布鲁氏菌病检测时,可先用RBT初筛,再用SAT或c ELISA复检。     

应用几种血清学诊断方法检测猪伪狂犬病血清抗体的比较试验

我们分别应用乳胶凝集试验(LAT)、琼脂免疫扩散试验(AGID)、血清中和试验(SN)3种诊断方法，对45份猪血清样品进行了猪伪狂犬病血清抗体检测，以进口试剂盒ELISA诊断方法为标准，对这3种血清学检测结果进行了比较分析。结果表明：LAT、AGID的可重复性均为100％；SN的准确性、敏感性、特异性均最为理想；LAT的敏感性较好，准确性和特异性稍差；AGID的准确性、敏感性、特异性均较差。     

川西北牦牛布鲁氏菌病血清流行病学调查

同时采用间接ELISA、虎红平板凝集试验和试管凝集试验三种血清学方法调查川西北牦牛布鲁氏菌病血清流行情况。对1070份采自川西北阿坝州8个草地县的牦牛血清样品经三种血清学方法检测,间接ELISA检测阳性率为25.4%（272/1070）,虎红平板凝集试验检测阳性率为12.7%（136/1070）,而试管凝集试验检测阳性率为9.1%（97/1070）。8个县均发现阳性布鲁氏菌病血清。与间接ELISA相比,虎红平板凝集试验的相对敏感性和特异性分别为50%和100%,而试管凝集试验的相对敏感性和特异性分别为35.7%和100%。布鲁氏菌病在川西北地区广泛存在,血清学方法是检测和监测布鲁氏菌病最常用和最简便的方法,其中间接ELISA方法最为敏感。     

猪瘟抗体检测方法的研究

本文探讨了猪瘟抗体的血清学检测方法,分别对IHA、2—ME—HI、SPA—ELISA、BLPA—ELISA及兔体中和试验进行了比较,结果表明它们之间有良好的相关性。IHA操作简单、易推广;BLPA—ELISA是新建立的血清学方法,敏感性高,用于猪瘟抗体的检测上,非特异性极低,阴、阳分界线可定在1:10。     

牛羊布鲁氏菌病四种血清学检测方法对比分析

[目的]对布鲁氏菌病的几种检测方法进行比对分析,为国家标准修订提供参考。[方法]对收集到的669份血清样本用虎红平板凝集试验（RBT）、试管凝集试验（SAT）、补体结合试验（CFT）和酶联免疫吸附试验（ELISA）方法进行检测,比较四种检测方法的一致性、敏感性与特异性。[结果]RBT、SAT、CFT、ELISA四种牛羊布鲁菌病的血清学检测方法一致率较高,Kappa值均大于或等于0.75。RBT敏感性较高,CFT特异性好,而SAT有一定的假阳性和假阴性,ELISA的敏感性和特异性都比较理想。[结论]用RBT初筛,用CFT和ELISA联合诊断结果较为理想。     

布鲁氏菌病血清学检测方法优缺点对比

布鲁氏菌病(简称布病)严重危害畜牧养殖业安全和人类健康,而有效的检测方法能够为布病的预防、检测和净化提供技术支持。目前针对布病的血清学检测方法主要包括:布病虎红平板凝集试验(RBT)、试管凝集试验(SAT)、全乳环状实验(MRT)、酶联免疫吸附试验(ELISA)、荧光偏振测定法(FPA)、补体结合试验(CFT)以及琼脂扩散试验(NH-GD)等。不同的血清学检测方法各有优缺点:RBT操作简便,敏感性较高,但环境会对检测结果产生一定影响;ELISA敏感性较高,可一次性检测多个样本,但对仪器要求较高;FPA短时间内能够检测大量样品,操作简单,特异性和敏感性与ELISA相似,但需要专业的荧光偏振仪器;SAT特异性较强,但敏感性不高,操作步骤繁琐;CFT的特异性和敏感性都高于SAT,但试验较为繁琐,耗时长;MRT一般只用于牛奶样本检测,无需采血,特异性强,但对牛奶的质量有一定要求;NH-GD对疫苗免疫样本和野毒感染样本具有鉴别诊断能力,但抗原纯度要求高。因此,RBT、MRT、ELISA、FAP和NH-GD更适合用于布病初筛,而SAT和CFT更加适用于布病复核。未来应探索更多的血清学检测方法,如荧光微球法、半抗原鉴别诊断方法等,以便为布病检测提供更优选择。     

间接血凝检测猪瘟抗体与ElisA检测结果对比观察

我们对猪瘟抗体的血清学检测方法,分别以间接血凝检测抗体方法(IHA)和ELISA进行比较,结果表明它们之间有较好的相关性。IHA操作简单,易于推广应用。ELISA用于抗体检测上,敏感性高。     

Sensitivity and specificity of two serological tests for the detection of ovine paratuberculosis

OBJECTIVE: To determine the sensitivity and specificity of an absorbed ELISA and an AGID test for the detection of clinical and subclinical paratuberculosis in sheep. DESIGN: By testing a panel of sera from 1257 Australian Merino and crossbred sheep greater than 1 year of age, of which 1137 sheep were not infected with Mycobacterium avium subsp paratuberculosis and 120 sheep had paratuberculosis. PROCEDURE: Sera were collected from 457 sheep in Victoria and 800 sheep in Western Australia. Presence of M a paratuberculosis infection in Victorian sheep was determined by histological examination of intestinal tissues, whereas sheep from Western Australia were presumed to be free of Johne's disease. The ability of an absorbed ELISA to discriminate between infected and uninfected sheep was described by test sensitivity and specificity, the distribution of ELISA OD, and the area under a receiver operating characteristic curve. RESULTS: The absorbed ELISA had a specificity of 98.2 to 99.5% (CI) and a sensitivity of 35 to 54% (CI). In sheep from infected flocks in Victoria, the AGID test had a specificity of 99 to 100% (CI) and a sensitivity of 38 to 56% (CI). The sensitivity of serological tests was higher in sheep with a body condition representative of the lower quintile of their flock of origin. CONCLUSION: The AGID test and absorbed ELISA are useful tests for the detection of ovine paratuberculosis. Although the tests had a similar accuracy, they detected different subpopulations of infected sheep with only moderate overlap. The AGID test had a higher specificity than the absorbed ELISA.     

Development and Bayesian evaluation of an ELISA to detect specific antibodies to Sarcoptes scabiei var suis in the meat juice of pigs

Samples of ear scrapings, serum and diaphragmatic muscle were collected from 271 fattening pigs at the slaughterhouse. The scrapings were examined for the presence of mites, and tests for specific antibodies to Sarcoptes scabiei var suis in the serum and meat juice were made with an experimental ELISA. The cut-off value for the meat-juice ELISA was estimated at an optical density of 0.5 by receiver operating characteristic curve analysis, on the basis of the cut-off value for the serum ELISA of 0.4. The results of the three tests were used in a Bayesian model to estimate the characteristics of each test. The specificity of the tests of the ear scrapings was considered to be 1 and their sensitivity was estimated by Bayesian analysis to be 0.86, with a 95 per cent confidence interval (CI) of 0.73 to 0.99. The sensitivity of the meat juice ELISA (0.71, 95 per cent CI 0.6 to 0.8) and its specificity (0.77, 95 per cent CI 0.66 to 0.89) were comparable with the sensitivity (0.73, 95 per cent CI 0.6 to 0.8) and specificity (0.81, 95 per cent CI 0.69 to 0.95) of the serum ELISA.     

Comparison of indirect fluorescent antibody test and enzyme linked immunosorbent assay in the detection of exposure of cattle to Theileria parva in Kenya.

Appraisal of the indirect fluorescent antibody test (IFAT) and antigen enzyme linked immunosorbent assay (ELISA) serological tests as carried out to detect cattle exposed to Theileria parva at the National Veterinary Research Centre, Muguga (NVRC), Kenya is reported. Using sera from T. parva naive cattle and cattle experimentally exposed to T. parva, the two tests were appraised in terms of their sensitivity and specificity. IFAT and ELISA had the same sensitivity of 90% while ELISA had a higher specificity (90%) than IFAT (80%). A comparison was also made of the capability of the two tests to detect exposure of dairy cattle to T. parva prior to immunization against East Coast fever (ECF). The positive outcome from the IFAT was significantly higher (chi 2 = 30.36; P < 0.001) than that from the ELISA. The agreement between the two tests was low (Kappa = 0.21). The two tests indicated a higher risk of ECF in the study area than was expected. Indications are that the ELISA has been effectively adopted at NVRC.     

检测鸡传染性支气管炎病毒抗体的三种血清学方法的比较

应用酶联免疫吸附试验（ＥＬＩＳＡ）、琼脂扩散沉淀试验（ＡＧＰ）和鸡气管环培养中和试验（ＳＮｉｎＴＯＣｓ）三种常规血清学方法对实验鸡血样的鸡传染性支气管炎病毒抗体进行了检测。从实验鸡血样的检测结果表明，ＥＬＩＳＡ和气管环中和试验的灵敏度较好，而ＡＧＰ的灵敏度相对较差，但三者均有较好的特异性。对田间送检血样的检测结果表明，ＥＬＩＳＡ与气管环中和试验、ＥＬＩＳＡ与ＡＧＰ的一致性均较好，而气管环中和试验与ＡＧＰ的一致性较差。ＥＬＩＳＡ效价与气管环中和试验效价的相关系数为０．８４     

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.     

A comparison of four serological tests for the diagnosis of caseous lymphadenitis in sheep and goats

A double antibody sandwich ELISA (ELISA A) developed for the detection of Corynebacterium pseudotuberculosis infection in sheep and goats was modified to improve its sensitivity. To establish the sensitivity and specificity of this modified ELISA (ELISA B), sera from 183 sheep and 186 goats were tested using ELISAs A and B. Comparison was also made with two further ELISAs (C and D) developed in Australia that, respectively, detect antibodies to cell wall antigens or toxin.ELISA B had the best performance of the four tests. Its specificity was 98+/-1% for goats and 99+/-1% sheep. Its sensitivity was 94+/-3% for goats and 79+/-5% for sheep. ELISA B will now be tested for use in caseous lymphadenitis eradication and control programmes in The Netherlands. It will also be used in experimental studies of CL in Scotland.     

Evaluation of two absorbed enzyme-linked immunosorbent assays and a complement fixation test as replacements for fecal culture in the detection of cows shedding Mycobacterium avium subspecies paratuberculosis.

Control of paratuberculosis in dairy herds is based on preventing the transmission of Mycobacterium avium subsp. paratuberculosis (Mptb) from cows to calves by management measures, supported by removal of cows excreting these bacteria by the fecal route (Mptb shedders). Fecal culture is the most accurate test for identifying Mptb shedders, but this technique is expensive and takes up to 16 weeks for results to be available. Serologic tests are inexpensive, rapid, and easy to perform. Of serologic tests, the complement fixation test (CFT) and absorbed enzyme-linked immunosorbent assay (ELISA) are the serologic tests used most frequently; the CFT is considered less accurate than the ELISA with respect to sensitivity and specificity. The commonly accepted absorbed ELISA is from the Australian Central Serum Laboratory. However, a European supplier has marketed a second ELISA that is supposed to be more sensitive in detecting Mptb shedders. These 2 absorbed ELISAs, designated ELISA-A and ELISA-B, and an in-house CFT were compared with data from 2 serum panels. The Mptb shedding panel consisted of sera from 198 culture-positive cows from 53 infected herds. The method used for culture of fecal samples was a modified J?rgensen method on individual samples. The Mptb shedder detection rate by the 3 serologic tests ranged from 29.8% to 39.4%. Detection rate for ELISA-A was lower than that for ELISA-B and CFT. For all 3 tests, detection rate was dependent on the level of Mptb shedding and the age of the animals. Detection rates increased as cattle age increased to 4 years. The specificity panel was initially composed of sera from 811 cows randomly selected from 41 herds without clinical paratuberculosis that were negative for Mptb based on whole-herd fecal culture. The modified J?rgensen method for culture was used on pooled fecal samples. Serologic test specificity ranged from 93.4% to 99.8%. The specificity of ELISA-A was higher than that of ELISA-B and CFT. Specificity of ELISA-B between herds was 75-100%. Specificity of CFT between herds was 62-100%. The low specificity of ELISA-B and CFT could not be explained by a higher sensitivity for Mptb-infected cows before onset of shedding, because in the 19 herds with 8 more subsequent negative whole-herd fecal cultures in the 4 years after sampling, specificity was not improved. The insufficient specificity of ELISA-B was not corrected sufficiently by heightening the cutoff value because Mptb shedder detection rate was lowered to 28.9%, equal to that of ELISA-A, and specificity only rose to 97%, much lower than that of ELISA-A. Taking into account the different test characteristics, serologic tests are a cost-effective alternative to fecal culture in high-prevalence herds. For certification programs, only ELISA-A is recommended because in a large number of nonsuspect herds specificity remained almost 100%.     

Evaluation of an enzyme-linked immunosorbent assay for the detection of antibodies to caprine arthritis-encephalitis virus in goat serum.

An indirect enzyme-linked immunosorbent assay (ELISA), was evaluated for its ability to detect serum antibodies against caprine arthritis-encephalitis virus (CAEV). The ELISA was compared to three other serological immunoassays, agar gel immunodiffusion test (AGIDT), immunoblot assay (IBA), and a fixed-cell immunoperoxidase assay (FCIPA). A total of 511 samples, from 40 farms representing a variety of goat breeds and ages were tested. An estimate of the ELISA sensitivity and specificity was made, relative to combined test results of the three other CAEV serological assays. The degree of agreement of test results among these four assays was evaluated. The number of positives detected by the ELISA, AGIDT, IBA and IPA tests was 193, 154, 204 and 163, respectively. Of the 511 sera tested, 172 were positive to any two or all three of these tests, and were defined as reference positive. A total of 237 samples were negative to all three reference tests, and were defined as reference negative. Relative to these references, the ELISA had a point estimate of 98.3% sensitivity and 97.9% specificity. There was good agreement between the ELISA and the other three assays with a kappa statistic of agreement greater than 0.7 for all three comparisons. The ELISA is therefore considered a suitable assay, with high sensitivity and specificity, for detection of antibodies to CAEV in serum.     

The development and validation of an antibody-ELISA to detect Trypanosoma evansi infection in cattle in Australia and Papua New Guinea

Trypanosoma evansi is exotic to Australia and Papua New Guinea (PNG). However, it might have been introduced to Papua (Indonesia); thus, there is a risk of it entering PNG and thence Australia. Because of logistical difficulties in PNG and northern Australia, surveillance for T. evansi must rely on serological tests. The accuracy of an Ab-ELISA using a detergent extract of T. evansi and three antigen fractions purified from the detergent extract using stepwise precipitation with saturated ammonium sulphate (AS) were compared. The ELISA using the AS 40-50% fraction had greater discriminatory power compared to the ELISA using the other antigen fractions. This ELISA then was compared with two commercial tests: the Card Agglutination Test for trypanosomiasis/T. evansi (CATT) and Suratex. CATT/T. evansi at 1/4 serum dilution has higher sensitivity and the ELISA has higher specificity. There is no likely benefit in combining antibody detection tests to improve the accuracy of diagnosis. Furthermore, the combination of Suratex (which was independent of the antibody tests) with the CATT or the ELISA did not improve the sensitivity. None of the tests was sufficiently sensitive to be used confidently to determine freedom from infection in animals imported into Australia from countries where T. evansi infection is endemic.     

Evaluation of an enzyme immunoassay for detection of antibodies to pseudorabies virus in porcine field sera.

The performance of an indirect enzyme-linked immunosorbent assay and the standard serum neutralization test for detection of antibodies to pseudorabies virus in porcine field sera were compared, using 304 sera from pseudorabies-free pigs in Canada, and 1082 and 580 swine sera from the USA and England, respectively. The sensitivity and specificity of the ELISA relative to the serum neutralization test were in the order of 97 to 98%, with the higher agreement between the tests when a 1:40 dilution of serum samples was used for the ELISA. The indirect ELISA was considered to be a rapid and convenient procedure, offering many advantages over the serum neutralization test for routine serodiagnostic use.