Ciliates

• Balantidium coli

  • largest protozoan and only ciliated parasite of man
• Balantidium coli


  initially identifies as Paramecium coli by Malmsten
• Cyst stage of Balantidium coli


  • double cyst wall
  • cilia between cyst wall
  • infective stage
• Troph stage of Balantidium coli


  • have 2 nuclei: Micronucleus and Macronucleus
• Blastocystis hominis


  • intestinal protozoan
  • previously classified as yeast
• 4 morphological forms of Blastocystis hominis

  • vacuolated
  • amoeba-like
  • granular
  • multiple fission
• Vacuolated form

  What morphological stage is this?

  • predominant in stool specimens
  • spherical shape
• Amoeba like forms


  What morphological stage is this?

  • occasionally observed in stool samples
  • exhibit active extension and retraction
• Granular forms


  What morphological stage is this?

  • multinucleated
  • observed from old cultures
  • granular forms develop into daughter cells of amoeba form when the cell raptures
• Multiple fission


  What morphological stage is this?

  • composed of 2 or more vacuoles