Balantidium coli inhabite the human intestine. Pigs and other animals, are reservoir host.

1. Ciliates
by Mr. chu Samuel N
BMLS,MSc HBB

2. TAXONOMY
 Phylum: ciliophora
 Class: litostomatea
 Order: Vestibuliferia
 Family: Balantidiidae

3. Learning Objectives
Upon completion of this topic , you should be able to:
 Discuss the general features ciliates
 Explain transmission and Illustrate the life cycle of
Balantidium coli
 Discuss the clinical feature of Balantidium coli
 Discuss prevention and control of Balantidium coli infection
 Distinguish trophozoite and cyst forms of Balantidium coli

4. Out line
 General features of Ciliates
 Blantidium coli
 Epidemiology, habitat , morphology, transmission and
life cycle, clinical features ,laboratory diagnosis
,treatment , prevention and control

5. Ciliates
General features
 have trophozoites and cyst
 The trophozoites are covered with short hairs (cilia ) by which
they move
 They reproduce asexually by binary fission and sexually by
conjugation
 They posses two dissimilar nuclei (Macro and micronucleus )
& large contractile vacuole

6. Balantidium coli
 The largest protozoan parasite of man
Epidemiology
 World wide being more commonly found amongst those who
keep pigs, and uses pig faeces as fertilizer especially in
warmer climates

7. Habitat: Trophozoite and cyst in the large intestine of pig and
rarely man
Morphology
Trophozoite
Size: 50-200 m by 40-70m
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
Bal…

8. Bal…
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 cytopyge
Contractile vacuole : one of the two may be visible

9. Bal…
Cyst
Size : 50-70m, the size of a
round worm egg
Shape: round
Shell: thin double wall
Nuclei: one large kidney shape
macronucleus & one small
Micronucleus beside the large
nucleus
Cytoplasm: granular, greenish,
filled with inclusion bodies
Cilia(inside wall) :sometimes
be seen in younger cyst

10. Bal…
Transmission and life cycle
 Human acquires through ingestion of contaminated food
or water or hands contaminated with pig faeces
containing cyst

11. life cycle

12. Bal…
 Following ingestion, excystation occurs in the small intestine
 The trophozoites reside in the lumen of the large intestine of
humans and animals, where they replicate
 Some trophozoites invade the wall of the colon& multiply
 Some return to lumen and disintegrate
 Trophozoites undergo encystation to produce infective cysts
 Mature cysts are passed with feces

13. Clinical feature
 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
Bal…

14. Bal…
Laboratory Diagnosis
 Finding the tropozoites in dysenteric faecal specimens and
the cysts in formed or semi formed faeces
 In dysenteric specimens the ciliates usually contain ingested
red cell
Treatment
 Tetracycline, metronidazole

15. Bal…
Prevention and Control
1.Avoid contamination of food or drink
2.Improving personal hygiene especially those who keep pigs.
3.Treatment and health information dissemination

16. summary
 Ciliates have trophozoite and cyst stage
 Balantidium coli
 The largest protozoan parasite of man which is pathogenic
to human being
 Human acquires through ingestion of contaminated food or
water or hands contaminated with pig faeces containing cyst
 Cause balantidial dysentery
 Diagnosis by the finding balatidium coli tropozoites and cysts
satge

17. Review questions
1. What are unique features of B.coli among other intestinal
protozoa?
2. What is the diagnostic and infective stage of the B.coli?
3. What is the prevention and control method of B. coli?

18. References
1.Awole M., Cheneke W. Medical Parasitology for Medical
laboratory Technology students. Upgraded lecture Notes
Series .2006.
2. Cheesbrough M. District laboratory practice in tropical
countries United Kingdom, Cambridge university press, 2000,
part I

19. Thank you
God is in you