Parasites - Dientamoeba fragilis
Dientamoeba fragilis is a parasite that lives in the large intestine of people. This protozoan parasite produces trophozoites; cysts have not been identified. The intestinal infection may be either asymptomatic or symptomatic.
Image: Binucleate (left) and uninucleate (right) trophozoites of D. fragilis, stained with trichrome. (Credit: DPDx)