<unk>  is a non-pathogenic species of Entamoeba that frequently exists as a commensal parasite in the human gastrointestinal tract. E.<unk>  (not to be confused with the bacterium Escherichia<unk>  is important in medicine because it can be confused during microscopic examination of stained stool specimens with the pathogenic Entamoeba histolytica. This amoeba does not move much by the use of its pseudopod, and creates a "sur place (non-progressive) movement" inside the large intestine. Usually, the amoeba is immobile, and keeps its round shape. This amoeba, in its trophozoite stage, is only visible in fresh, unfixed stool specimens. Sometimes the<unk>  have parasites as well. One is the fungus Sphaerita spp. This fungus lives in the cytoplasm of the E.<unk> . While this differentiation is typically done by visual examination of the parasitic cysts via light microscopy, new methods using molecular biology techniques have been developed. The scientific name of the amoeba, E.<unk> , is often mistaken for the bacterium, Escherichia<unk> . Unlike the bacterium, the amoeba is mostly harmless, and does not cause as many intestinal problems as some strains of the E.<unk>  bacterium. Some of these harmful strains are inside raw or uncooked meat that is consumed. For example, the bacterium, E.<unk>  O157:H7, which can cause illness, and even death, if eaten. To make the naming of these organisms less confusing, "alternate contractions" are used to name the species for the purpose making the naming easier; for example, using Esch.<unk>  and Ent.<unk>  for the bacterium and amoeba, instead of using E.<unk>  for both. Common lifecycle of non-pathogen parasites.
Entamoeba coli
Entamoeba histolytica
Ascaris lumbricoides
Entamoeba moshkovskii
Schistosoma haematobium
Schistosoma mansoni
Taenia solium
Cryptosporidium parvum