Submitted to: Journal of Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 30, 2000
Publication Date: N/A
Interpretive Summary: Parasites of the genus Sarcocystis are single-celled parasites of livestock and wild animals. Certain species of Sarcocystis cause abortion and mortality in livestock. Sarcocystis campestris is a parasite of badgers and ground squirrels. Scientists at the Beltsville Agricultural Research Center and the Virginia-Maryland College of Veterinary Medicine report Sarcocystis campestris infection in a squirrel for the first time in the U.S. The results will be of interest to biologists and parasitologists.
Grossly visible sarcocysts were seen in the skeletal muscles of 1 of 12 13-lined ground squirrels, Spermophilus tridecemlineatus tridecemlineatus, collected in Nebraska, USA. The tissue cyst wall was up to 5.0 um thick and contained spike-like projections. Transmission electron microscopy of tissue cysts revealed they were similar but not identical to Sarcocystis campestris Cawthorn, Wobeser, and Gajadhar, 1983 previously known only from experimental infections in Richardson's ground squirrel, Spermophilus richardsonii. Prominent electron dense bodies were observed lining the microfilaments present in the spike-like projections of the sarcocyst wall. This is the first report of S. campestris in a natural intermediate host and the first report of this parasite outside of Saskatton, Canada.