Stankiewicz M, Jeska E L, Froe D L
Veterinary Medical Research Institute, Iowa State University, Ames 50011.
J Parasitol. 1990 Jun;76(3):383-8.
Cross-bred 3- and 8-wk-old pigs were used to test whether drug-abbreviated infections with Ascaris suum can stimulate acquired resistance to challenge. During the immunization period, both age groups of animals were infected with increasing numbers of A. suum eggs (500, 1,000, 2,000, 5,000, 10,000, and 20,000) at 7-day intervals while the pigs were receiving pyrantel tartrate in the feed. Two days after the last infective dose, animals were placed on unmedicated feed for 8 days and then challenged with 10,000 eggs. All pigs were killed 7 days after challenge, and milk spots on the livers and larvae recovered from the lungs were counted. Larval recoveries from lungs of the immunized animals were significantly smaller than those from the unimmunized animals in both age groups, suggesting that the pigs were capable of acquiring strong resistance to parasitic infections. In immunized animals, challenge infection did not contribute significantly to milk spot formation. The number of milk spots was significantly greater in the older animals, indicating that milk spot formation may be age related.
使用杂交的3周龄和8周龄猪来测试猪蛔虫药物缩短感染是否能刺激获得性抗攻击能力。在免疫期间，两个年龄组的动物在接受饲料中添加的噻嘧啶时，每隔7天感染数量递增的猪蛔虫卵（500、1000、2000、5000、10000和20000）。在最后一次感染剂量后两天，将动物置于无药物饲料中8天，然后用10000个卵进行攻击。在攻击后7天处死所有猪，并对肝脏上的乳斑和从肺中回收的幼虫进行计数。两个年龄组中免疫动物肺中的幼虫回收率均显著低于未免疫动物，这表明猪能够获得对寄生虫感染的强大抵抗力。在免疫动物中，攻击感染对乳斑形成的贡献不显著。老年动物中的乳斑数量显著更多，表明乳斑形成可能与年龄有关。
