Taxonomy: Class Blastocystea
Animal: Blastocystis hominis 8 04 .jpg
Sites: Gut
Blastocystis hominis EM - Cyst form. The cysts arises from multivacuolar forms in the colon, are about 5 microns wide, usually one (occ. up to 4) nucleus with a crescentic band of chromatin, thick cyst wall and very small vacuoles. It is shedding the thick fibrillar surface coat which covers the other forms of Blastocystis and may act as a mechanical and chemical protection against host responses - the cyst wall may develop under this surface coat which is shed on maturation of the cyst. The cyst wall may protect the organism from the harsh external environment. This may be the transmissible stage but this has not been proven (EM by Deb Stenzel). (Compare the appearance of these more usually encountered cysts with those of the abnormal cysts in a patient present with severe gastrointestinal symptoms - 6 15 - 6 24)

First Picture | Previous Picture | Next Picture | Last Picture