Entamoeba coli – Cyst

  • Cyst is the infective stage to human
  • Cysts detected in faecal specimens of infected human
Diagnostic Features
  • Shape: Spherical
  • Size: 15 – 25 mm (range 10 to 35 µm) – larger than histolytica
  • Nuclei: Contains up to 8 nuclei (usually >4 visible; need to change fine focus to see nuclei in different planes)
  • Large, eccentric karyosome in nucleus; Regular, coarse chromatin dots on nuclear membrane
  • Chromatoid bars visible occasionally – splinter-like with pointed ends
  • Diffused glycogen mass seen in immature and mature cysts

Magnification X10

Magnification X40

Magnification X100