Eriksen L, Bøgh H O, Loftager M, Lind P
Danish Centre for Experimental Parasitology, The Royal Veterinary and Agricultural University, 88 Dyrlaegevej, Copenhagen DK-1870 Frederiskberg C, Denmark.
J Vet Med B Infect Dis Vet Public Health. 2004 May;51(4):185-90. doi: 10.1111/j.1439-0450.2004.00752.x.
This experimental study was designed to compare the acquired resistance in pigs to Ascaris suum eggs following 4-weekly oral immunizations with either 200 A. suum infective eggs or 50 A. suum third stage larvae (L3). The two immunized groups (n = 7) together with an unimmunized control group (n = 7) of pigs were challenged orally with 50 infective A. suum eggs per kilogram bodyweight on day 19 after the last immunization. Seven days post-challenge the group immunized with eggs showed signs of resistance as evidenced by reduced lung larval counts compared with the challenge control group. Such significant resistance was not observed in the L3-immunized group. However, a markedly increased inflammatory liver reaction and white spot formation was demonstrated in the L3-immunized pigs after challenge compared with both control animals and egg-immunized pigs. On the day of challenge only the egg-immunized pigs mounted an anti-Ascaris antibody response both in serum and in lung lavage fluid. Ascaris-antigen induced increased histamine release from peripheral leucocytes following both immunization and challenge could only be demonstrated in the egg-immunized pigs. On day 7 post-challenge local IgA-anti-Ascaris antibodies were further demonstrated in bile of the egg-immunized group and in the small intestine of both immunized groups. In conclusion, oral A. suum egg immunization of pigs induced a significant reduction in lung larval counts upon challenge. In contrast, oral L3 immunization seemed to prime the pigs as observed by the presence of stunted lung larval growth and increased liver reaction post-challenge with A. suum eggs.
本实验研究旨在比较猪在每隔4周口服200个猪蛔虫感染性虫卵或50个猪蛔虫第三期幼虫（L3）进行免疫后，对猪蛔虫卵获得性抵抗力的情况。两组免疫组（每组n = 7）以及一组未免疫的猪对照组（n = 7）在最后一次免疫后第19天，每千克体重口服50个感染性猪蛔虫卵进行攻毒。攻毒后7天，与攻毒对照组相比，虫卵免疫组出现了抵抗力迹象，表现为肺内幼虫数量减少。L3免疫组未观察到如此显著的抵抗力。然而，与对照动物和虫卵免疫猪相比，L3免疫猪在攻毒后出现了明显增强的肝脏炎症反应和白斑形成。在攻毒当天，只有虫卵免疫猪在血清和肺灌洗液中产生了抗蛔虫抗体反应。只有在虫卵免疫猪中才能证明，免疫和攻毒后蛔虫抗原诱导外周白细胞组胺释放增加。攻毒后第7天，在虫卵免疫组的胆汁以及两组免疫猪的小肠中进一步检测到局部IgA抗蛔虫抗体。总之，猪口服猪蛔虫卵免疫在攻毒时可显著减少肺内幼虫数量。相比之下，口服L3免疫似乎使猪产生了预激状态，表现为攻毒猪蛔虫卵后肺内幼虫生长发育迟缓以及肝脏反应增强。
