Sweeney R W, Whitlock R H, Buckley C L, Spencer P, Rosenberger A E, Hutchinson L J
Department of Clinical Studies, New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square 19348.
Am J Vet Res. 1994 Jul;55(7):905-9.
An ELISA containing lipoarabinomannan (LAM) antigen was used to detect antibodies in milk and serum for diagnosis of Mycobacterium paratuberculosis infection in dairy cattle. In experiment 1, milk and serum samples were obtained from 25 cows, and subjected to LAM ELISA testing immediately, and after 1 year of storage at -70 C. Milk samples, with and without a commonly used chemical preservative, were tested. There was no significant difference in LAM ELISA results between fresh and frozen samples or between preserved and unpreserved milk samples. In experiment 2, milk samples were collected daily from 30 cows over a 14-day period. The day-to-day coefficient of variation was 0.19 for milk LAM ELISA and was 0.15 for serum LAM ELISA, with no statistically significant time effect detected. In experiment 3, single milk, serum, and fecal samples were obtained from 764 cows. The fecal samples were cultured for M paratuberculosis to identify infected cows, and the serum and milk samples were subjected to LAM ELISA testing. Results were compared, using the area under the receiver operating characteristic curves. The milk LAM ELISA had specificity (+/- 95% confidence limits) of 87 +/- 8.1% when the cutoff was set at 50% sensitivity, and specificity of 83 +/- 9.1% when sensitivity was set at 60%. The area under the receiver operating characteristic curve was 0.85 +/- 0.03 for the milk ELISA and 0.75 +/- 0.02 for the serum ELISA. In this population of cattle, the milk LAM ELISA had comparable accuracy to serum LAM ELISA, although the milk LAM ELISA was slightly less reproducible (higher coefficient of variation).
一种含有脂阿拉伯甘露聚糖（LAM）抗原的酶联免疫吸附测定（ELISA）用于检测奶牛乳汁和血清中的抗体，以诊断副结核分枝杆菌感染。在实验1中，从25头奶牛采集乳汁和血清样本，立即进行LAM ELISA检测，并在-70℃储存1年后再次检测。对添加和未添加常用化学防腐剂的乳汁样本进行了检测。新鲜样本与冷冻样本之间或添加防腐剂与未添加防腐剂的乳汁样本之间，LAM ELISA结果无显著差异。在实验2中，在14天内每天从30头奶牛采集乳汁样本。乳汁LAM ELISA的每日变异系数为0.19，血清LAM ELISA的每日变异系数为0.15，未检测到统计学上显著的时间效应。在实验3中，从764头奶牛采集单一的乳汁、血清和粪便样本。对粪便样本进行副结核分枝杆菌培养以鉴定感染奶牛，对血清和乳汁样本进行LAM ELISA检测。使用受试者工作特征曲线下面积比较结果。当将临界值设定为50%灵敏度时，乳汁LAM ELISA的特异性（±95%置信限）为87±8.1%，当灵敏度设定为60%时，特异性为83±9.1%。乳汁ELISA的受试者工作特征曲线下面积为0.85±0.03，血清ELISA的受试者工作特征曲线下面积为0.75±0.02。在这群奶牛中，乳汁LAM ELISA与血清LAM ELISA的准确性相当，尽管乳汁LAM ELISA的重复性略差（变异系数较高）。
