THE INVASION OF THE RABBIT INTESTINAL-TRACT BY EIMERIA-INTESTINALIS SPOROZOITES

To follow the route of migration of Eimeria intestinalis sporozoites f rom the excystation stage to their development in the epithelial cells of the ileum, we inoculated sporocysts into the duodenum of coccidia- free rabbits and euthanized the animals at 10 min to 12 h post-inocula tion. Excystation occurred at less than 10 min after the experimental infection. The sporozoites penetrated into the epithelium of the duode num at as early as 10 min post-inoculation; 6 h later, the number of s porozoites had dramatically decreased in the duodenal mucosa, with a c orresponding increase being noted in the ileal mucosa. These findings suggest that sporozoites invade the duodenal epithelium and migrate to the ileum by an as yet unknown nonlumenal tissue route.