Whittington R J, Eamens G J, Cousins D V
NSW Agriculture, Elizabeth Macarthur Agricultural Institute, Camden, New South Wales 2570.
Aust Vet J. 2003 Jan-Feb;81(1-2):71-5. doi: 10.1111/j.1751-0813.2003.tb11437.x.
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.
A laboratory study.
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.
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.
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.
确定澳大利亚兽医诊断实验室目前用于检测山羊副结核分枝杆菌感染的血清学检测方法的特异性。
一项实验室研究。
研究了四项检测，包括使用源自牛分离株（山羊或牛源）的副结核分枝杆菌抗原进行的琼脂凝胶免疫扩散试验（AGID）、山羊副结核吸收酶联免疫吸附试验（EMAI）和CSL PARACHEK副结核吸收酶免疫分析（EIA）。在检查了从西澳大利亚州（一个无副结核病的地区）收集的1000份山羊血清样本后，评估了AGID和ELISA检测副结核病（副结核）的特异性。此外，还使用两个存档样本中的血清，对新南威尔士州少数患有副结核病的山羊的检测性能进行了比较。
在适当的阳性-阴性临界值下，AGID检测的特异性为100%，而两种吸收ELISA的特异性为99.7%至99.8%。基于对感染山羊的少量血清样本的检测，吸收ELISA检测出患有副结核病的山羊数量约为AGID的两倍。每种检测方法都能检测出副结核动物，无论感染是由副结核分枝杆菌的牛株还是羊株引起的。
ELISA和AGID检测副结核病的方法都具有高特异性，可用于市场保证计划，而不会产生大量假阳性检测结果的风险。然而，结果表明ELISA在检测感染山羊方面更敏感，应优先于AGID使用。本研究中评估的两种ELISA形式具有相似的特征，可用于山羊产业的副结核病控制计划，但关于敏感性的更多数据将增加对其应用的信心。
