Rhinosporiodiosis

Question 1

Causative agent

Answer 1

t is a chronic granulomatous disease caused by Rhinospo-

ridium seeberi and affects both man and animal

Question 2

the life cycle of the organism

Answer 2

trophic stage

Development of sporangium

Production of endospores

Question 3

Trophic stage The endospore is

Answer 3

oval or rounded, 6–8 μm in size, clear cytoplasm, vesicular nucleus with a nucleo- lus and a covering of chitin. It gradually increases in size, begins to divide cytoplasm and nucleus forming small endospores by several divisions. Trophocyte becomes large filled with young endospores.

Question 4

Development of sporangium

Answer 4

The mature trophocyte then develops into sporangium. A sporangium is 200– 250 μm in diameter, contains 12,000–16,000 endospores. It has a thick wall consisting of two layers: outer chitinous and inner cellulose layer.
Endospores mature with the formation of mucoid and chitinous wall. Sporangium filled with thousands of endospores develops a germinal pore ready to burst and liberate the endospores.

Question 5

Production of endospores

Answer 5

Sporangium filled with endo- spores develops high internal pressure and ruptures liberating endospores into the surrounding tissue. If internal pressure is not high, spores are liberated one by one without breaking the wall. After liberation endo- spores start their life as trophic stage. Some endospores are carried by lymphatic channels to the blood stream to cause disseminated form of disease.