prorozoans trophozoite

Motility and Characteristics of Amoeba Species

• E. dispar: Motility is non-progressive, fingerlike; karyosome is small and central; peripheral chromatin is fine and evenly distributed; cytoplasm is finely granulate; cytoplasmic inclusions are ingested RBCs.

• E. histolytica: Motility is sluglike, blunt; karyosome is large and usually centrally located; peripheral chromatin is absent; cytoplasm is granular and usually vacuolated; cytoplasmic inclusions are notable for causing PAM (primary amoebic meningoencephalitis).

• E. hartmanni: Motility is non-progressive, blunt; karyosome is large, irregular, and eccentric; peripheral chromatin is unevenly distributed; cytoplasm is coarse and granulated; cytoplasmic inclusions are vacuoles containing bacteria.

• E. coli: Motility is normal in stool (sluggish, non-progressive) and diarrheal stool (progressive, unidirectional); karyosome is small and central; peripheral chromatin is fine and evenly distributed; cytoplasm is granular and vacuolated; cytoplasmic inclusions are ingested bacteria and other food particles.

• Acanthamoeba: Motility is sluggish, spinelike; karyosome is large; peripheral chromatin is granular and vacuolated; cytoplasm is granular and usually vacuolated; cytoplasmic inclusions are notable for causing PAM (primary amoebic meningoencephalitis) and GAE (granulomatous amoebic encephalitis) and some eye infections.

• Naegleria: Motility is active, varying pseudopod appearance; karyosome is centrally located; peripheral chromatin is fine and evenly distributed; cytoplasm is finely granulated; cytoplasmic inclusions are leukocytes, epithelial cells, and bacteria, which can be examined through mouth scrapings.

• Balamuthia: Motility is sluggish, non-progressive blunt; karyosome is large, irregular, and blotlike; peripheral chromatin is absent; cytoplasm is granular and vacuolated; cytoplasmic inclusions are bacteria.

• Free-living Amoeba: Motility is sluggish, usually progressive; karyosome is large, usually central, with refractive acromatic granules that may or may not be present; peripheral chromatin is absent; cytoplasm is coarsely granular and vacuolated; cytoplasmic inclusions are bacteria, yeast cells, and other debris.

Balantidium coli

• Young oocyst has two sporoblasts; mature oocyst has two sporocysts, each containing four sausage-shaped sporozoites.
• Centrally located fluid-filled structure consumes almost 90% of the organism.

Identify the characteristics of Entamoeba, a genus of parasitic amoebae, including their motility, karyosome, peripheral chromatin, and cytoplasm. Learn about the distinguishing features of E. dispar and more.