Dobson R J, Barnes E H
CSIRO Division of Animal Health, McMaster Laboratory, Blacktown, NSW, Australia.
Int J Parasitol. 1995 Apr;25(4):495-501. doi: 10.1016/0020-7519(94)00157-j.
Twenty-one-week-old, worm-free, pen-reared lambs were infected with either 6000 O. circumcincta L3 per week, or 3000 H. contortus L3 per week, or both (9000 L3 per week). Egg counts were monitored throughout the experiment, and worm burdens and larval establishment rates of both worm species were estimated after 4, 7, 10 and 13 weeks of infection. After 10-13 weeks of infection with H. contortus only, establishment of O. circumcincta was lower than in previously uninfected controls, demonstrating that a high level of immunity to H. contortus affords some cross-protection against O. circumcincta. Total H. contortus worm burdens and egg counts (about 2000 worms and 3000 e.p.g., respectively) in sheep infected with both worm species were less than half those observed in sheep infected with H. contortus alone (about 5000 worms and 10,000 e.p.g., respectively). Cross-protection between the two species was observed, but was probably less important than the reduction in H. contortus establishment that was caused by O. circumcincta disrupting abomasal physiology.
21周龄、未感染寄生虫、在围栏中饲养的羔羊，每周分别感染6000条环形奥斯特线虫L3期幼虫，或3000条捻转血矛线虫L3期幼虫，或两种寄生虫同时感染（每周9000条L3期幼虫）。在整个实验过程中监测虫卵计数，并在感染后4、7、10和13周估计两种寄生虫的虫负荷和幼虫定植率。仅感染捻转血矛线虫10 - 13周后，环形奥斯特线虫的定植率低于未感染过的对照组，这表明对捻转血矛线虫的高水平免疫能提供一定程度的针对环形奥斯特线虫的交叉保护。同时感染两种寄生虫的绵羊，其捻转血矛线虫的总虫负荷和虫卵计数（分别约为2000条虫和3000个虫卵/克）不到仅感染捻转血矛线虫的绵羊（分别约为5000条虫和10000个虫卵/克）的一半。观察到两种寄生虫之间存在交叉保护，但这可能不如环形奥斯特线虫破坏皱胃生理导致捻转血矛线虫定植减少那么重要。
