title: Sarcocystis sigmodontis n. sp. from the cotton rat (Sigmodon hispidus).
abstract: Sarcocystis sarcocysts were found in 3 of 4 cotton rats (Sigmodon hispidus) from Atlanta, Georgia. Sarcocysts were several centimetres long and were present only in skeletal muscles. The sarcocyst wall appeared thin (less than 1 micron), with minute projections in the light microscope. By transmission electron microscopy, the sarcocyst wall had 0.6-1.0 x 0.21-0.36-micron villar protrusions without microtubules. The metrocytes were 6.5 x 3.8 micron, and the bradyzoites were 8 x 2.7 micron. The sarcocysts were not infectious for dogs and cats. The parasite was named Sarcocystis sigmodontis because it differed from all sarcocysts in rodents.
mesh_terms: D000818:Animals; D003411:Arvicolinae / Q000469:parasitology*; D002415:Cats; D004285:Dogs; D005845:Georgia; D012522:Sarcocystis / Q000145:classification / Q000302:isolation & purification* / Q000648:ultrastructure