Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2000
Publication Date: N/A
Interpretive Summary: Sarcocystis neurona is a single celled parasite. It causes a fatal neurologic disease (EPM) in horses in the U.S. Opossums (Didelphis virginiana) are the main reservoir of this infection. Horses become infected by ingesting food and water contaminated with opossum feces. Little is known of the prevalence of S. neurona in Mississippi. Scientists sat the Beltsville Agricultural Research Center and Mississippi State University found S. neurona in feces of 19 of 72 opossums from rural Mississippi. These results will be of use to veterinarians, parasitologists and horse owners.
Technical Abstract: Sarcocystis species sporocysts were found in intestinal scrapings from 24 of 72 opossums (Didelphis virginiana) from rural Mississippi. The number of sporocysts in each opossum varied from a few (<100000) to 187 million. Sporocysts from 24 opossums were bioassayed for S. neurona infections by feeding to gamma-interferon knockout (KO) mice. Sarcocystis neurona was detected in the brains of KO mice fed sporocysts from 19 opossums by immunohistochemical staining with anti-S. neurona specific, polyclonal rabbit serum. Sarcocystis neurona was cultured in vitro from the brains of KO mice fed sporocysts from 15 opossums.