Submitted to: Journal of Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 30, 2001
Publication Date: N/A
Interpretive Summary: Sarcocystis neurona is a single-celled parasite of animals. It causes a fatal disease of horses in the Americas. There is no vaccine or effective therapy to control this disease. The life cycle stages of this parasite are not completely known. A scientist at the Beltsville Agricultural Research Center has found that an immune-deficient mouse is a good animal model for S. neurona. In these mice the parasite is spread in the body via blood. The results will be of interest to pathologists, parasitologists, and biologists.
Technical Abstract: Early localization and parasitemia of Sarcocystis neurona were studied in gamma interferon gene knockout (KO) mice fed S. neurona sporocysts. Mice were examined for S. neurona infection histologically, immunohistochemically, and by bioassay in KO mice. For bioassay, blood and tissue homogenates were inoculated subcutaneously into KO mice. Parasitemia was demonstrated by bioassay in KO mice 1 through 8 days after feeding sporocysts (DAFS). Sporozoites were seen in histologic sections of all regions of small intestine and in cells in Peyer's patches of a mouse killed 6 hr after feeding sporocysts. At 1 DAFS, organisms were present in all regions of small intestine and were also seen in mesenteric lymph nodes. At 3 DAFS, organisms had begun to invade extra-intestinal tissues. Sarcocystis neurona was demonstrated histologically in mouse brain as early as 4 DAFS.