Submitted to: Journal of Eukaryotic Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/24/2003
Publication Date: 11/20/2003
Citation: Dubey, J.P., Cawthorn, R.J., Speer, C.A., Wobeser, G.A. 2003. Redescription of the sarcocysts of sarcocystis rileyi (apicomplexa : sarcocystidae. Journal of Eukaryotic Microbiology. 50:476-482. Interpretive Summary: Sarcocystis species are single-celled parasites of livestock and humans. They can cause morbidity and mortality in livestock. Scientists at the Beltsville Agricultural Research Center redescribe the structure of Sarcocystis rileyi, a parasite commonly found in ducks. These findings will be of interest to biologists and parasitologists.
Technical Abstract: The intermediate hosts for Sarcocystis rileyi ( Stiles 1893 ) Minchin 1913 are ducks (Anas spp.), and the striped skunk (Mephitis mephitis) is its definitive host. The structure of sarcocysts from an experimentally-infected shoveler duck (Anas cylpeata) fed sporocysts from an experimentally-infected M. mephitis was studied and compared with type specimens from a naturally-infected duck. The experimentally-infected duck was killed 154 days after feeding sporocysts. By light microscopy the sarcocyst wall was 3-5 um thick with indistinct villar protrusions. Ultrastructurally, the sarcocyst wall was a type-23 cyst wall with anastomosing villar protrusions that were up to 7.5 um long. The villar projections contained filamentous structures. The bradyzoites were 12-14 um long. Structurally, the sarcocyst from the naturally-infected and experimentally-infected ducks appeared similar.