Parasitology Diagnostic Laboratory

Iodamoeba butschlii

The image below is a trichrome-stained cyst of Iodamoeba butschlii, a nonpathogenic amoeba distributed worldwide. Although it can be difficult to differentiate the trophozoites of Iodamoeba butschlii from Endolimax nana, the cysts of Iodamoeba are very distinctive. They contain a single nucleus with a large karyosome and no peripheral chromatin. Cysts are 5-20 µm and also contain a large well-defined glycogen vacuole. Infection occurs via the fecal oral route. The trophozoites are 8-20 µm and their internal structure is similar to that of cysts except that the granular cytoplasm contains many vacuoles.