Entamoeba coli has a worldwide distribution and is one of the most commonly reported Entamoeba species in clinical specimens. Non-human primates may serve as reservoir hosts. Trophozoites of E. coli measure 15–50 μm and have a single nucleus with irregular peripheral chromatin and a usually eccentric karyosome.
Entamoeba coli, E. hartmanni, E. polecki, Endolimax nana, and Iodamoeba buetschlii are generally considered nonpathogenic and reside in the large intestine of the human host . Both cysts and trophozoites of these species are passed in stool and considered diagnostic . Cysts are typically found in formed stool, whereas trophozoites are typically ...
The cyst form is rounded, 10 to 20 µm in diameter, with one to four nuclei showing the characteristic appearance. A chromatoidal bar with rounded or square ends may be seen. Classification and Antigenic Types Pathogenic strains can be grown at 37° C but not at room temperature and fall into specific enzyme assay groups.
E. histolytica cysts have a maximum of four nuclei, while the commensal Entamoeba coli cyst has up to 8 nuclei. Additionally, in E. histolytica, the endosome is centrally located in the nucleus, while it is usually off-center in Entamoeba coli. Finally, chromatoidal bodies in E. histolytica cysts are rounded, while they are jagged in Entamoeba ...
In addition, the cyst form of Entamoeba coli typically contains five to eight nuclei (see Fig. 109-2 ). Entamoeba coli is nonpathogenic and requires no specific treatment; however, it is a valuable marker of fecal-oral exposure, and it can be found concurrently with E. histolytica in 10% to 30% of patients in endemic regions. 7
Cysts of Entamoeba coli are usually spherical, but may be elongated, and measure 10 to 35 µm. Mature cysts typically have 8 nuclei but may have as many as 16 or more. Entamoeba coli is the only species in the genus encountered in humans with more than four nuclei in the cyst stage. The nuclei may be seen in unstained as well as stained specimens.
Nov 6, 2018 · The early cyst contains single nucleus. In case of E. histolytica, as the cyst matures, the nucleus undergoes two successive mitotic divisions to form two and then four nuclei. The mature cyst is quadrinucleate. Hence number of nucleus varies from one to four. It varies from one to eight in case of E. coli, and mature cyst contains eight.