- Common non-pathogenic commensal of human
- Habitat in human: Large intestines
- Trophozoites detected in faecal specimens of infected human
Diagnostic Features
- Live parasites show sluggish movements
- Size: 20 – 25 µm (range 15 to 50 µm) – larger than E. histolytica
- Shape: Irregular with blunt pseudopodia
- Nucleus: One nucleus; Peripheral chromatin granules: irregularly distributed & coarse
- Large, usually eccentric karyosome in nucleus
- Cytoplasm appears coarse, often with vacuoles
- No RBCs in cytoplasm; Bacteria, yeast, etc., present
