Björkman C, Gondim L F P, Näslund K, Trees A J, McAllister M M
Department of Clinical Sciences, Swedish University of Agricultural Sciences, P.O. Box 7019, SE-75007 Uppsala, Sweden.
Vet Parasitol. 2005 Mar 31;128(3-4):195-200. doi: 10.1016/j.vetpar.2004.11.030. Epub 2005 Jan 27.
The avidity (functional affinity) of specific antibodies are being used to estimate duration of bovine Neospora caninum infection. Here, we report for the first time the avidity pattern in cattle orally inoculated with N. caninum oocysts. In all, 16 pregnant cows and 7 calves were administered N. caninum oocysts. In the cows, the avidity increased during the early course of infection. In all but one, the avidity was < or = 35 during the first 6 weeks after infection and no cow had an avidity value >50 until week 9. The calves were sampled either week 6 (n = 3) or week 9 (n = 9) after infection, and by then had avidities between 2 and 17. The results are in agreement with results from previous investigations of naturally infected cattle, and calves that were experimentally infected with tachyzoites. They further validate the ability of the N. caninum iscom avidity ELISA to accurately assess the duration of infection.
特定抗体的亲和力（功能亲和力）正被用于估计牛新孢子虫感染的持续时间。在此，我们首次报告了经口接种新孢子虫卵囊的牛的亲和力模式。总共对16头怀孕母牛和7头小牛接种了新孢子虫卵囊。在母牛中，感染初期亲和力增加。除一头母牛外，其他所有母牛在感染后的前6周内亲和力≤35，直到第9周没有母牛的亲和力值>50。小牛在感染后第6周（n = 3）或第9周（n = 9）进行采样，此时它们的亲和力在2至17之间。这些结果与先前对自然感染牛以及经实验感染速殖子的小牛的研究结果一致。它们进一步验证了新孢子虫iscom亲和力ELISA准确评估感染持续时间的能力。
