Walker R L, Read D H, Loretz K J, Hird D W, Berry S L
California Veterinary Diagnostic Laboratory System, University of California, Davis 95616, USA.
Am J Vet Res. 1997 Jul;58(7):744-8.
To determine whether a humoral response against spirochetes isolated from papillomatous digital dermatitis (PDD) lesions is elicited in dairy cattle affected with PDD.
41 cattle with PDD from 8 dairies (study population) and 30 cattle from 2 dairies free of PDD (control population). Additionally evaluated were 32 cattle from a dairy with a past history of PDD but no current disease, and 52 cattle from a dairy with high prevalence of PDD, 25 with and 27 without detectable lesions.
ELISA were used to evaluate the humoral response of all cattle to representative isolates from 2 groups of spirochetes of unknown species isolated from PDD lesions. Specificity of the response was evaluated, using immune sera prepared against each of the spirochetes, and by adsorption studies of immune and field sera. The potential for confounding by an antibody response to other spirochetes associated with diseases of cattle was assessed.
The antibody response (specific) to both PDD spirochete groups of cows with PDD was significantly increased, compared with that of cows from PDD-free dairies. There was no association between antibody response to PDD-associated spirochetes and antibody response to other spirochetal diseases of cattle. None of the cattle from the dairy with previous history of PDD but without current disease were classified as test positive by either PDD ELISA. There was a significant (P < 0.01) difference in classification results for both PDD ELISA for cattle with PDD from the dairy with a high herd prevalence of PDD, compared with cattle without detectable disease from the same dairy.
The humoral response in cattle with PDD lesions was significantly different from that in cattle without detectable lesions, thus providing additional information regarding the potential role of spirochetes isolated from PDD lesions in the etiopathogenesis of PDD.
确定患有乳头瘤状指皮炎（PDD）的奶牛是否会引发针对从PDD病变中分离出的螺旋体的体液免疫反应。
来自8个奶牛场的41头患有PDD的奶牛（研究群体）和来自2个无PDD奶牛场的30头奶牛（对照群体）。此外，还评估了来自一个曾有PDD病史但目前无疾病的奶牛场的32头奶牛，以及来自一个PDD高发奶牛场的52头奶牛，其中25头有可检测到的病变，27头没有。
采用酶联免疫吸附测定（ELISA）来评估所有奶牛对从PDD病变中分离出的2组未知种类螺旋体的代表性菌株的体液免疫反应。使用针对每种螺旋体制备的免疫血清，并通过免疫血清和现场血清的吸附研究来评估反应的特异性。评估了对与牛疾病相关的其他螺旋体的抗体反应造成混淆的可能性。
与无PDD奶牛场的奶牛相比，患有PDD的奶牛对两组PDD螺旋体的抗体反应（特异性）显著增强。对与PDD相关螺旋体的抗体反应与对牛的其他螺旋体疾病的抗体反应之间没有关联。来自曾有PDD病史但目前无疾病的奶牛场的奶牛，通过任何一种PDD ELISA检测均未被归类为检测阳性。与来自同一奶牛场无可检测到疾病的奶牛相比，来自PDD高发奶牛场的患有PDD的奶牛在两种PDD ELISA的分类结果上存在显著（P < 0.01）差异。
患有PDD病变的奶牛的体液免疫反应与无可检测到病变的奶牛显著不同，从而为从PDD病变中分离出的螺旋体在PDD病因发病机制中的潜在作用提供了更多信息。
