Submitted to: Journal of Eukaryotic Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 20, 1999
Publication Date: N/A
Interpretive Summary: Sarcocystis neurona is a single celled parasite that can cause fatal neurologic diseases (equine protozoal myeloencephalitis, EPM) in horses. The diagnosis in the living horse is made by the detection of antibodies to S. neurona in cerebrospinal fluid (CSF) of the horse. The S. neurona grown in cell culture is used to detect these antibodies. However, little is known of the antigenic variation among isolates of S. neurona. Scientists at Beltsville Agricultural Research Center and the Oregon State University report antigenic characterization of a recent isolate of S. neurona (SN6). These findings with be useful to veterinarians, pathologists, diagnosticians, and parasitologists.
An isolate of Sarcocystis neurona (SN6) was obtained from the spinal cord of a horse from Oregon with neurologic signs. The parasite was isolated in cultures of bovine monocytes and equine spleen cells. The parasite divided by endopolygeny and completed at least one asexual cycle in cell cultures in 3 days. Two gamma interferon knockout mice inoculated with cell culture-derived merozoites became ill 35 days later and S. neurona schizonts and merozoites were found in encephalitic lesions. The parasite in tissue sections of mice reacted with S. neurona - specific antibodies and S. neurona was reisolated from the brain of knockout mice.