Cruz-Rojo M A, Martínez-Valladares M, Rojo-Vázquez F A
Universidad de León, Facultad de Veterinaria, Campus de Vegazana, 24071, León, Spain.
Vet Parasitol. 2012 Sep 10;188(3-4):386-90. doi: 10.1016/j.vetpar.2012.04.006. Epub 2012 Apr 5.
The aim of this study was to evaluate the IgG activity in serum and milk samples of experimentally infected lactating ewes with the nematode Teladorsagia circumcincta as well as its relationship to the degree of infection. In a previous study 28 pregnant ewes were divided into two homogeneous groups, with high (H) and low (L) level of parasitism, respectively. Blood and milk samples were taken weekly after lambing until the end of the lactation, 126 days post-partum (pp). IgG against T. circumcincta were measured by means of an indirect ELISA. The kinetic of the immunoglubulins in serum samples showed a very low activity at the beginning but gradually increased throughout the lactation; H group showed higher values most of the sampled days than L group. Contrary, IgG in milk samples remained high during the first month pp, then decreased around 38% and by the end of the study rose again. Antibodies in both samples were correlated and especially during the second month of lactation (r=0.3; p<0.001). With the aim to correlate the immune response and the degree of infection we found an inverse relationship (r=-0.2; p<0.05) during the second month of lactation between eggs and IgG in serum. However the correlation with immunoglobulins in milk was positive, mainly, on the last third of lactation (r=0.2; p<0.01). As a conclusion, the individual detection of total IgG antibodies against T. circumcincta in lactating ewes is highly dependent on the stage of lactation. Therefore, these associations should be confirmed under field conditions.
本研究的目的是评估经实验感染环形泰勒虫的泌乳母羊血清和乳汁样本中的IgG活性及其与感染程度的关系。在之前的一项研究中，28只怀孕母羊被分为两组，分别具有高（H）和低（L）寄生虫感染水平。产羔后每周采集血液和乳汁样本，直至泌乳结束，即产后126天（pp）。通过间接ELISA法检测抗环形泰勒虫的IgG。血清样本中免疫球蛋白的动力学在开始时活性非常低，但在整个泌乳期逐渐增加；在大多数采样日，H组的值高于L组。相反，乳汁样本中的IgG在产后第一个月保持较高水平，然后下降约38%，在研究结束时再次上升。两个样本中的抗体具有相关性，尤其是在泌乳的第二个月（r = 0.3；p < 0.001）。为了将免疫反应与感染程度相关联，我们发现在泌乳的第二个月，血清中的虫卵与IgG之间呈负相关（r = -0.2；p < 0.05）。然而，与乳汁中免疫球蛋白的相关性为正，主要在泌乳的最后三分之一阶段（r = 0.2；p < 0.01）。结论是，泌乳母羊中抗环形泰勒虫总IgG抗体的个体检测高度依赖于泌乳阶段。因此，这些关联应在田间条件下得到证实。
