The life cycle of Entamoeba histolytica begins when humans ingest infective cysts via feces, fingers, food, fomites, and fleas. Then the cyst passes to the small intestine where excystation occurs and trophozoites multiply asexually by binary fission. The diagnostic stage is marked by resistant, infective cysts passed in feces.
Trophozoites of E. histolytica with ingested erythrocytes stained with trichrome. The ingested erythrocytes appear as dark inclusions. The parasite above show nuclei that have the typical small, centrally located karyosome, and thin, uniform peripheral chromatin
A certain parasitic amoeba (Entamoeba histolytica) kills about 70,000 people each year, but how exactly it causes apparent, devastating tissue damage has been unclear. Recently, a group of researchers found that the amoebas actually kill a person's cells by eating those cells alive! It's a very unusual tactic. You can read more about it at http://www.biology-bytes.com/ (Image credit: Stefan Walkowski)