Lindsay D S, Blagburn B L, Dubey J P
Department of Pathobiology, College of Veterinary Medicine, Auburn University, Alabama 36849-5519.
Infect Immun. 1990 Aug;58(8):2699-700. doi: 10.1128/iai.58.8.2699-2700.1990.
Neospora caninum and Toxoplasma gondii are structurally related protozoal parasites of mammals that may cause abortion and neonatal morbidity and mortality. Groups of mice were subcutaneously inoculated with 10(5) live zoites of the NC-1 or NC-3 isolates of N. caninum and reinoculated with an identical number of live zoites 2 weeks later. Groups of mice which were injected subcutaneously with Hanks balanced salt solution served as controls. Three weeks after the final N. caninum inoculation, one-half of the mice were inoculated subcutaneously with 2.5 x 10(4) zoites of the RH isolate of T. gondii and the other half were inoculated subcutaneously with 2.5 x 10(4) zoites of the GT-1 isolate of T. gondii. Serum samples taken from mice on the day of T. gondii inoculation were negative for specific antibodies to T. gondii, but mice inoculated with N. caninum had reciprocal titers of greater than or equal to 800 to this protozoan. All of the mice died after challenge with T. gondii, and no significant differences (P greater than 0.05) between the survival times of mice inoculated with either isolate of N. caninum and those of control mice were seen. This study indicates that N. caninum and T. gondii are distinct biologic entities and not closely related isolates.
犬新孢子虫和刚地弓形虫是结构相关的哺乳动物原生动物寄生虫，可导致流产以及新生动物发病和死亡。将几组小鼠皮下接种10⁵个犬新孢子虫NC - 1或NC - 3分离株的活速殖子，2周后再接种相同数量的活速殖子。皮下注射汉克斯平衡盐溶液的几组小鼠作为对照。在最后一次接种犬新孢子虫三周后，一半小鼠皮下接种2.5×10⁴个刚地弓形虫RH分离株的速殖子，另一半小鼠皮下接种2.5×10⁴个刚地弓形虫GT - 1分离株的速殖子。在接种刚地弓形虫当天从小鼠采集的血清样本中，针对刚地弓形虫的特异性抗体呈阴性，但接种犬新孢子虫的小鼠针对这种原生动物的双向滴度大于或等于800。所有小鼠在受到刚地弓形虫攻击后死亡，接种犬新孢子虫任一分离株的小鼠与对照小鼠的存活时间之间未观察到显著差异（P＞0.05）。这项研究表明，犬新孢子虫和刚地弓形虫是不同的生物实体，并非密切相关的分离株。
