PARA311: Prelim - Sarcomastigophora

Amoeba

Equipped with the ability to extend their cytoplasm in the form of pseudopods (false feet), which allows them to move.

Significant Amoeba in Humans

• Entamoeba

• Naegleria

• Acanthamoeba

Entamoeba Species

• Entamoeba coli

• Entamoeba hartmanni

• Entamoeba dispar

• Entamoeba moshkovskii

• Enatamoeba gingivalis

• Entamoeba histolytica (pathogenic)

The only pathogenic Entamoeba spp.

Entamoeba histolytica

Entamoeba polecki

A zoonotic protozoans of pigs and monkey.

Wet mount stained with iodine

Entamoeba polecki

Trichrome Stain

Entamoeba polecki

Free living protozoans found mainly in freshwater.

Naegleria and Acanthamoeba

Trophozoite

Escystation; delicate, fragile and motile (pseudopods)

Cysts

Non-feeding stage, have protective cell wall. Encystation.

Entamoeba

Characterized by vesicular nucleus with comparatively small karyosome located at or near its center and with varying characteristic of the peripheral chromatin attached to the nuclear membrane.

Entamoeba that is non lumen dwelling protozoan.

Entamoeba gingivalis

Entamoeba whose infective stage is not the cystic stage.

Entamoeba gingivalis

He first described E. histolytica

Losch (Russian)

E. histolytica (T)

Size: 16-60 um

Motility: pseudopods

Cytoplasm: hyaline-like (ectoplasm); hematophagous (with ingested RBCs

Nucleus: karyosome is located centrally

E. histolytica (C)

Size: 10-20 um

Nuclei: quadrinucleated mature cysts

Cytoplasm: chromatoidal bar