2. Balantidium coil
• Balantidium (=Neobalantidium) (=Balantioides) coli, a large ciliated
protozoan, is the only ciliate known to be capable of infecting humans.
• It is often associated with swine, the primary reservoir host. Recent
molecular analyses have suggested the need for taxonomic revision, and it
is now sometimes referred to as Neobalantidium coli or Balantioides
coli, although this nomenclature has neither been resolved nor widely
adopted in the medical community
• Geographical Distribution: World wide being more commonly found
amongst those who keep pigs, and uses pig faeces as fertilizer especially in
warmer climates.
Habitat: Trophozoite and cyst in the large intestine of pig and rarely man.
3. Morphology
Trophozoite
• Size: 50-200 μm by 40-70μm
• Shape: Oval, with one pole more rounded than the other.
• Motility: Rapid motility, crossing the field in a definite direction and
sometimes turning in circle.
• Cilia: Cover the whole body and many around the cytostome
• Nucleus: a large kidney shaped macronucleus and a small
micronucleus .
• Cytostome: a sort of “mouth” that contracts and expands to draw in
debris also has cytophage
4. • Cyst
• Size : 50-70μm, very large cyst /the size of a round worm egg.
• Shape: round
• Shell: thin double wall
• Nuclei: one large kidney shape macronucleus and one small
Micronucleus beside the large nucleus.
• Cytoplasm: granular, greenish, filled with inclusion bodies.
5. LIFE CYCLE
• Cysts are the stage responsible for transmission of balantidiasis. The
host most often acquires the cyst through ingestion of contaminated
food or water. Following ingestion, excystation occurs in the small
intestine, and the trophozoites colonize the large intestine. The
trophozoites reside in the lumen of the large intestine and appendix
of humans and animals, where they replicate by binary fission, during
which conjugation may occur. Trophozoites undergo encystation to
produce infective cysts. Some trophozoites invade the wall of the
colon and multiply, causing ulcerative pathology in the colon wall.
Some return to the lumen and disintegrate. Mature cysts are passed
with feces.
6.
7. Pathogenicity
• It is the only ciliate that parasitize humans.
• Causes balantidial dysentery.
• Infection with B.coli can be without symptoms unless the ciliates
invade the intestinal wall.
• Invasion can cause inflammation and ulceration, leading to dysentery
with blood and mucus being passed with faeces.
8. Prevention and Control
1. Avoid contamination of food or drink.
2. Improving personal hygiene especially those who keep pigs.
3. Treatment and health education.
9. Laboratory Diagnosis
• Finding the tropozoites in dysenteric faecal specimens and the cysts in
formed or semiformed faeces.
• In dysenteric specimens the ciliates usually contain ingested red cell.
