First isolation of Sarcocystis hominis from cattle in Japan.

Sarcocystis hominis was first isolated from slaughtered cattle raised in Japan. Cysts were 1,220-4,460 x 80-384 microns in size and their wall was 3 to 6 microns thick and appeared radially striated in the histopathological sections because of the presence of palisade-like villar protrusions on the surface. The protrusions were 3.1-4.3 x 0.7-1.1 microns in size and had many microtubules in the core. Two cynomolgus monkeys, Macaca fascicularis, fed with the Sarcocystis cysts began to pass sporocysts, which measured a size of 14.3-15 x 9.5-10 microns, in the feces 10 days after ingestion.