SARCOCYSTIS SUIHOMINIS DETECTED FOR THE FIRST TIME FROM PIGS IN JAPAN

Sarcocystis suihominis was detected for the first time in Japan from the heart and diaphragm of 5 out of 600 older culled breeding pigs slaughtered in Saitama Prefecture, Japan. Fresh cysts were 1,080-2,040 × 106-170 μm in size. Bradyzoites measured 15 × 4 μm on average. The cyst wall was usually observed thick, 4-6 μm, and striated, but occasionally thin and smooth according to the difference in sectioning angle and in portion of cysts. Scanning electron microscopy showed that many palisade-like villar protrusions, 6-7 × 0.3-0.5 μm in size, were closely folded onto the surface of cyst. A small number of microtubules were seen in the core of protrusion. No dogs nor domestic cats fed with 20 fresh cysts each excreted oocysts or sporocysts in the feces throughout the experimental period of 30 days.