Morphology and life cycle of leishmania donovani

Morphology and life cycle of leishmania donovani

1. MORPHOLOGY AND LIFE CYCLE OF LEISHMANIA DONOVANI

2. Leishmania Donovani . L. Donovani causes visceral leishmaniasis It is also known as kala azar and black fever. It is found at dum dum , calcutta thats why it is also known as dum dum fever.

3. Morphology. The parasite exists in two forms . a. Amastigote form ; In humans and other mammals. b. Promastigote form ; In sandfly and artificial culture.

4. Amastigote form. Aflagellar stage also called L-D body. Round or oval in shape . 2-4 micro meter in length . Seen in reticulo endothelial cell of vetebrate host. i.e man ,dog and other mammals . Nucleus usually situated in the middle of the cells or along the sides of the cell wall

5. Contd... Kinetoplast lies at the right angle to the nucleus . Axoneme is delicate filament extending from the kinetoplast to the margine of the body and represents the root of the flagellum .

6. Promastigote form. Flagellar stage . Seen in digestive tract of sandfly . Spindle shaped. Measures 15-20 micro meter in length and 1-2 micro meter in breadth. There is no undulating membrane.

7. Contd... Nucleus is situated centrally. Kinetoplast lies transversely near the anterior end. The flagellum is single delicate and measures 15-28 micro meter . A vacuole is present near the root of the flagellum

8. LIFE CYCLE. Leishmania donovani completes its life cycle in two host a. Definitive host ; man , dog and other mammals b. Vector ; female sandfly ( phlebotomus species) Infective form ; promastigote form present in midgut of female sandfly