ATLASINTESTINAL PARASITES (Protozoa)
      KINETOFRAGMINOPHOREA Order: Trichostomatida

      BALANTIDIUM COLI

      Adapted and redrawn from NCDC

      bal1-ic

      Balantidium coli: B.coli is the largest ciliated protozoon found in humans.
      Pigs, large primates and humans are the reservoir of the parasite.
      Faecal-oral is the commonest mode of transmission
      (other route are person-to-person and water).
      (Life cycle.)


      Courtesy of John H. Cross, Professor.

      bal2-ic

      Balantidium coli: B.coli can cause a severe colitis with ulcerations like ameobiasis.
      Large trophozoites are recognized in faeces by their size (50-80 by 40-60 µm)
      and the presence of cilia.
      (Trophozoite in fresh sample).


      Courtesy of John H. Cross, Professor.

      bal3-ic

      Balantidium coli: the large ciliated trophozoites have a cytostome
      that continues in the cytopharynx,
      2 contractile vacuoles controlling the osmotic pressure and two nuclei:
      the micronucleus and the crescent-shaped macronucleus.
      (Wet mount preparation).


      Courtesy of John H. Cross, Professor.

      bal4-ic

      Balantidium coli: details of the trophozoite (cilia and cytostome).
      (Wet mount preparation).


      Courtesy of John H. Cross, Professor.

      bal5-ic

      Balantidium coli: details of the trophozoite (cilia and macronucleus).
      (Wet mount preparation).


      Courtesy of John H. Cross, Professor.

      bal6-ic

      Balantidium coli: the trophozoite after excistation invades the submucosa
      of the large intestine.
      Trophozoites divide by binary fission within the submucosa.
      (Wet mount preparation in relief).


      Courtesy of John H. Cross, Professor.

      bal7-ic

      Balantidium coli: diagnosis is obtained by microscopic observation of trophozoites
      and/or cysts in faeces in fresh or formalin concentrated preparations.
      Rectal biopsy can also provide specimens for diagnosis.
      (MIF concentration).


      Courtesy of John H. Cross, Professor.

      bal8-ic

      Balantidium coli: encystation happens in the lumen with the formation
      of a mature cyst containing a single trophozoite.
      Cysts are round and measure 55 µm.
      Cysts are mature when they have a complete wall.
      (Immature cyst at fresh examination).

      bal2, bal3, bal4, bal5, bal6, bal7, bal8
      Courtesy of john H. Cross, PhD:
             Professor, Tropical Public Health Division of Tropical Public Health,
      Department of Preventive Medicine and Biometrics,
      Uniformed Services University of the Health Sciences,
      F.Edward Hebert School of Medicine Bethesda, Maryland        


      Courtesy of Dr. Gustavo A. Gini Courtesy of Dr. Gustavo A. Gini Courtesy of Dr. Gustavo A. Gini
      Bal9-ic Bal10-ic Bal11-ic

      Balantidium coli: cyst and two vacuolated trophozoites.

      Courtesy of Dr. Gustavo A. Gini:
       Quimico-Biologo, Microbiologist, Bacteriology
      Professor at University of del Valle of Guatemala
      Former Chief of Microbiology Department and Director
      of School of Chemical Biology University of San Carlos of Guatemala