5. CYST OF Balantidium coli
• Rounded
INFECTIVE STAGE
• 50–70 μm
• Cilia
• nuclear characteristics are similar to those of trophozoites.
6. TROPOZOITE OF Balantidium coli
• 40-200 um
• uniformly covered with cilia
• large macronucleus
• micronucleus is infrequently visible
• food vacuoles and contractile vacuoles are present in the cytoplasm
8. What is the reservoir host of B. coli?
• Pigs
• Potentially: rodents and non human primates.
9. Compare the pathology caused by B.
coli and E. histolytica.
• Balantidiasis - most people infected with
Balantidium coli experience no symptoms.
• infects the large intestine in humans and
produces infective microscopic cysts that
are passed in the feces, potentially leading to
re-infection or infection of others.
10. Compare the pathology caused by B.
coli and E. histolytica.
• Amebiasis - symptoms are often quite mild
and can include loose feces, stomach pain,
and stomach cramping.
• may invade mucus membranes of the
colon, forming abscesses and granulomas
called amebomas.
• Rarely, invades the liver, lungs, or brain
and forms an abscess
11. Give the laboratory methods employed
for Balantidium coli identification.
Stool examination - wet mount is preparation
-cysts or trophozoites in the patient's stools
• Sigmoidoscopy - To take a tissue sample from
the large intestine visually examine the
intestinal lining to look for bleeding, ulcers, and
inflammation in order to diagnose the cause of
diarrhea and other GI complaints and obtain
small tissue specimens.
12. Update
• A Cover of Glass: First Report of Biomineralized Silicon in a Ciliate, Maryna umbrellata (Ciliophora:
Colpodea)
• Using hydrofluoric acid, scanning electron microscope-assisted X-ray microanalysis, and
energy-filtered transmission electron microscopy, we present the first definite proof of
biomineralized silicon [(SiO2)]nin a ciliophoran protist, Maryna umbrellata, a common
inhabitant of ephemeral pools. In the trophic specimen, the amorphic silicon (glass)
granules are accumulated in the anterior half of the body. When entering the dormant
stage, most glass granules are excreted to form the surface cover of the globular resting
cyst. Most likely, the silicon granules are synthesized in vesicles of the Golgi apparatus.
First, nanospheres with a size of 20–40 nm are formed in a fibrous matrix; they grow to be
spongious complexes, eventually becoming amorphous glass granules with an average size
of 819 nm × 630 nm. In the transmission electron microscope, the silicon granules show
the characteristic fracture pattern of glass known from many other silicon-bearing
organisms. A literature survey suggests that silicon is very rare in ciliates. The fine structure
and genesis of silicon granules in M. umbrellata are very similar to those of other
organisms, including vascular plants and animals, indicating a common mechanism. Light
perception and protection against mechanical stress and predators might be functions of
the silicon granules in M. umbrellata. The palaeontological significance of glass cysts in
ciliates is also discussed.
13. References:
• http://www.ncbi.nlm.nih.gov/pmc/articles/P
MC2917745/ - update
• John, D.T. Petri, W.A. Markell and Voge’s
Medical Parasitology. 9th Edition. 2010
• McPherson, R.A., Pincus, M.R. Henry’s Clinical
Diagnosis and Management by Laboratory
Methods. 22nd Edition. 2011
• Tortora, G.J.et al. Microbiology An
Introduction. 10th Edition. 2010
