CILIATED PROTOZOAEXERCISE #12

BSMT3D GROUP 6: LOPEZ, DAVID, CAPIL

CILIATES

• have cilia that are similar to but shorter than flagella

Balantidium coli

• only ciliate that is a human parasite • largest protozoan to infect humans

PROCEDURE:• EXAMINE PREPARED SLIDES UNDER THE

MICROSCOPE

CYST OF Balantidium coli

• Rounded• 50–70 μm• Cilia • nuclear characteristics are similar to those of trophozoites.

INFECTIVE STAGE

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

LIFE CYCLE OF Balantidium coli

What is the reservoir host of B. coli?

• Pigs • Potentially: rodents and non human primates.

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.

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

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.

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.

References:

• http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2917745/ - 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