Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA.
Vet Parasitol. 2011 Sep 27;181(2-4):239-47. doi: 10.1016/j.vetpar.2011.03.051. Epub 2011 Apr 16.
The Gulf Coast Native (Native) breed of sheep among many others is identified as being relatively resistant to Haemonchus contortus, an abomasal nematode parasite of small ruminants. Understanding the mode of immune response that helps these breeds of sheep control infection could help design and implement appropriate control programs. In this experiment, the components of the immune response during the early infection period in resistant Native lambs were evaluated and compared with susceptible Suffolk breed of sheep. Groups (n=5) of six month old Native and Suffolk lambs were given infective larvae as one time (single) or trickle experimental infections. Fecal, blood, and serum samples were collected on days 0, 2, 7, 14 and 21 post-infection. Abomasal mucosa and regional lymph node samples were collected at the time of necropsy on days 14 and 21. There was no significant difference in number of worms recovered at necropsy but the ratio of adult versus larvae was significantly greater in single infected Suffolk than Native lambs. Native lambs had significantly greater numbers of mast cells and eosinophils in the abomasal mucosa and serum IgG production was significantly greater compared to Suffolk lambs. Native lambs also showed a trend of increased level of serum IgA and IgE compared to Suffolk lambs.
海湾海岸本地（Native）绵羊品种与其他品种一样，被认为对捻转血矛线虫具有相对抗性，捻转血矛线虫是一种寄生在小反刍动物皱胃中的寄生线虫。了解有助于这些绵羊品种控制感染的免疫反应模式，可以帮助设计和实施适当的控制计划。在这项实验中，评估了在抗性本地羔羊早期感染期间的免疫反应成分，并与易感的萨福克品种绵羊进行了比较。将 6 月龄的本地和萨福克羔羊（每组 5 只）给予一次（单次）或滴注实验感染感染性幼虫。在感染后第 0、2、7、14 和 21 天采集粪便、血液和血清样本。在第 14 和 21 天剖检时采集皱胃黏膜和区域淋巴结样本。在剖检时回收的蠕虫数量没有显著差异，但在单次感染的萨福克羔羊中，成虫与幼虫的比例明显高于本地羔羊。与萨福克羔羊相比，本地羔羊的皱胃黏膜和血清中的肥大细胞和嗜酸性粒细胞数量明显更多，血清 IgG 产生也明显更多。与萨福克羔羊相比，本地羔羊的血清 IgA 和 IgE 水平也呈现出增加的趋势。
