microbio. visit BISHAL CHAUHAN channel for lecture.

1. Leishmania
donovani

2. • Phylum: Sarcomastigophora
• Class: Zoomastigophora
• Genus: Leishmania

3. • Geographical distribution
– Endemic: India, China, Africa, Southern Europe, South
America & Russia
• Habitat
– Parasite of R.E. system
– In the vertebrate host, is always intracellular:
amastigote form

4. • Morphology:
– Amastigote stage (Aflagellar stage): man
– Promastigote form (Flagellar stage): gut of
sandfly & in artificial culture

6. Amastigote stage
• Shape: Round or oval body 2-4 µm
• Cell membrane: delicate
• Nucleus: ‹1 mm in diameter; oval or round
• Kinetoplast comprises of DNA- containing body & a
mitochondrial structure: lies at rt. angle to nucleus
• Axoneme: filament extending from kinetoplast: represents the
root of flagellum

7. Promastigote stage
• Slender spindle shaped body: 15-20µm X 1-2
µm
• Nucleus: central
• Flagellum projects from the front

8. • Reservoir of infection: dog; man
• Transmission: sandfly of genera Phlebotomus &
Lutzomyia

9. Life cycle

10. • Man
– Amastigote form: multiplies by binary fission; host cell enlarged :
becomes packed by parasites, eventually ruptures
– Parasite again taken up by fresh cells & the cycle is repeated
– Some free amastigotes phagocytosed by neutrophilic granulocytes &
monocytes (macrophages)
• Sandfly draws these free amastigote form a.w.a those within
monocytes during its blood meal
Life cycle

11. • Sandfly
– Amastigote forms develop into promastigote form: multiply by
binary fission in the mid gut of sandfly
– The flagellates then spreads to anterior part of alimentary canal
(pharynx & buccal cavity)
– Heavy pharyngeal infection observed b/w 6-9th day after blood
meal (anterior station infection)
– Bite of sandfly: infection

13. • Incubation period: 3-6 months
• Clinical features
– Pyrexia: double rise in 24 hrs
– Splenic enlargement
– Liver enlarged
– Epistaxis
– Skin dry,rough & pigmented
– Jaundice
– Anemia

14. Diagnosis
• Direct evidences
– Microscopy
• Splenic pulp tissue
• Bone marrow
• Blood
• Lymph node: aspirate or biopsy

15. – Culture
• 1-2 ml of blood taken aseptically from a vein: diluted
with 10ml citrated saline solution
• Cells allowed to settle in a cool incubator (22˚C)
• Cellular deposits inoculated in the water of
condensation of N.N.N medium (Novy, MacNeal,
Nicolle ) : incubated at 22˚C for 1-4 weeks

16. Serological test
• DAT
• RK-39 test

17. • Indirect evidences
– Blood count: neutropenia, relative increase of lymphocytes
& monocytes
– Serological tests: Aldehyde test: for rise of gamma globulin
– Antimony tests
– Complement fixation tests with W.K.K. antigen

18. • Leishmanin test
• Adler’s test

19. Treatment
• Antimony compounds
• Pentamidine isethionate

20. Prophylaxis
• Attack on parasite
• Attack on vector
• Personal prophylaxis

21. Post kala azar dermal
leishmaniasis
• Depigmented macules
• Erythematous patches
• Yellowish pink nodules