Virus-like particles in Blastocystis sp. from simian faecal material.

Virus-like particles were observed in the cytoplasm of Blastocystis sp. found in fresh faecal material from 2 monkeys (Macaca fascicularis). Two morphological types of particles were found during examination by transmission electron microscopy: 1 was approximately 55-60 nm diameter, with an electron-opaque core of approximately 30 nm in diameter; and the other was approximately 200 nm in diameter with a core of approximately 100 nm in diameter. This is the first report of virus-like particles identified in situ in Blastocystis.