Submitted to: Journal of Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 5, 1999
Publication Date: N/A
Interpretive Summary: Sarcocystis species are single-celled parasites of livestock and humans. Herbivores (intermediate hosts) become infected by ingesting food and water contaminated with sporocysts (resistant stages) excreted in the feces of carnivores. The North American opossum is host for three pathogenic species of Sarcocystis: Sarcocystis neurona which causes a fatal disease in nhorses; Sarcocystis falcatula which causes mortality in birds; and an unnamed species which causes fatal disease in rodents. Scientists at the Beltsville Agricultural Research Service and the Agricultural University in Argentina have for the first time isolated a Sarcocystis species from the South American opossum, Didelphis albiventris and are studying its pathogenicity in different hosts. These results will be useful to parasitologists and wildlife biologists.
Sarcocystis sporocysts from the intestines of 2 opossums (Didelphis albiventris) from Argentina were fed to gamma-interferon knockout (KO) and nude mice. Protozoal schizonts were seen in brain, liver, spleen, and adrenal glands of mice examined 33 to 64 days after feeding sporocysts. Sarcocysts were seen in skeletal muscles of KO mice 34 to 71 days after feeding sporocysts. Schizonts and sarcocysts were structurally similar to Sarcocystis sp. of Dubey, Speer and Lindsay, 1998 seen in mice fed sporocysts from the North American opossum, Didelphis virginiana from the U.S.