Winterhoff C, Beyerbach M, Homuth M, Strutzberg K, Gerlach G F
Gesellschaft für Innovative Veterinärdiagnostik (IVD-GmbH), An-Institut der Tierärztlichen Hochschule Hannover.
Dtsch Tierarztl Wochenschr. 2002 May;109(5):230-4.
Mycobacterium avium ssp. paratuberculosis (M. paratuberculosis) is the etiological agent of paratuberculosis (Johne's Disease), a chronic granulomatous enteritis of ruminants occurring worldwide with increasing frequency and leading to growing economic losses. Continuous surveillance of dairy farms would be advisable, particularly with respect to the increasing economic importance of paratuberculosis and the high tenacity of the pathogen, which can persist in the environment for many months. So far, such measures have not been taken as the cost-intensive collection of serum samples would have been required. Based on these considerations, it was the aim of this study to evaluate an economically viable diagnostic method for antibody detection using milk samples. This objective was reached by establishing a milk-ELISA. A commercially available test (Svanovir-ELISA by Svanova, Sweden) was chosen, because this ELISA has an excellent specificity with respect to cultural examination of the ileocaecal lymph node ("Gold-Standard"). The Svanovir-ELISA could be successfully adapted for testing milk for antibodies against M. paratuberculosis. The milk is skimmed by centrifugation and is diluted 1:10 for testing. The inter-assay-variation was 17%. A comparative antibody analysis done in parallel with milk and serum samples from 601 dairy cows using the Svanovir-ELISA showed a significant correlation between the results obtained with both methods. The optimal "cut-off" for the milk-ELISA of 46 EUMS (> 46 EUMS = positive) resulting in a specificity of 94.6% and a sensitivity of 60.9% was confirmed by receiver-operator characteristics (ROC) analysis. In the meantime the Svanovir-ELISA has been licensed for use with milk samples in Germany.
副结核分枝杆菌（M. paratuberculosis）是副结核病（约翰氏病）的病原体，这是一种反刍动物的慢性肉芽肿性肠炎，在全球范围内发病率不断上升，导致经济损失日益增加。建议对奶牛场进行持续监测，特别是考虑到副结核病日益增加的经济重要性以及该病原体的高韧性，它可在环境中持续存在数月之久。到目前为止，尚未采取此类措施，因为此前需要进行成本高昂的血清样本采集。基于这些考虑，本研究的目的是评估一种使用牛奶样本进行抗体检测的经济可行的诊断方法。通过建立牛奶ELISA实现了这一目标。选择了一种市售检测方法（瑞典Svanova公司的Svanovir-ELISA），因为该ELISA相对于回盲部淋巴结的培养检查（“金标准”）具有出色的特异性。Svanovir-ELISA能够成功适用于检测牛奶中抗副结核分枝杆菌的抗体。牛奶通过离心脱脂，并稀释1:10用于检测。批间变异为17%。使用Svanovir-ELISA对601头奶牛的牛奶和血清样本进行的平行比较抗体分析表明，两种方法获得的结果之间存在显著相关性。通过受试者工作特征（ROC）分析确定了牛奶ELISA的最佳“临界值”为46 EUMS（> 46 EUMS = 阳性），特异性为94.6%，敏感性为60.9%。与此同时，Svanovir-ELISA已在德国获得用于牛奶样本检测的许可。
