Parasites - Blastocystis spp. infection
Blastocystis is a common microscopic organism that inhabits the intestine and is found throughout the world. A full understanding of the biology of Blastocystis and its relationship to other organisms is not clear, but is an active area of research.
Image: B. spp. cyst-like forms in wet mounts under differential interference contrast (DIC) microscopy. (Credit: DPDx)