Leishmania Donovani

 Leishmania Donovani

Common name:- Kala-azar

Discovery:- It is named after discovery Leishmann and Donovan, both of whom reported an organism simultaneously. Leishmann from London in may 1903 and Donovan from Madras in July 1903.

Geographical distribution:- Endemic in many places in India and China allver the world.in India it is specially common in Assam, W. Bengal, also coasts of Brahma, Ganga ,also in Bihar, Orissa, M.P. & U.P.

RE syaurabitat:- It is essentially a parasite of R.E. System.

Morphology:-

Also read :BARGAIN

 Parasite exist in 2 stages -

1. Amastigote stage: Occurs in man

2. Promastigote stage:- 

Occurs in-a) Gut of insect sandfly

b) Artificial culture

1) Amastigote stage or Aflagellar:-Parasite in this stage resides in cells of R.E system of vertebrate host,man, dog, etc. characteristic of this form arc-

> Shape:- Round or oval

Also read : 🩸 A short story of Pulsatilla

> Size:-2-4 um along longitudinal axis, cell membrane is delicate.

>Nucleus:- Small, less than 1 m, situated centrally or at sides of cellwall.

>Kinetoplast :- lies tangertiaily/right angles to the nucleus.It contains DNA containing body and mitochondria.

Axoneme:- (Rhizoplast)- A delicate filament extending from the kinetoplastto the margin of the body. It represent the root of flagellum.

Vacuole:- A clear unstained space lying along the side of axoneme.

KimatopkastNucteuBatal-bodyAxenemeFig:- Amastigote stageParasitology (H.S.C) 63

AxonomPost andQC(Flagellumto kinetoplast.→Basal bodyFig:- Promastigote stage

Also read :Lycopodium

2) Promastigote stage (Flagellar):- This stage is present only in vector and culture.

Shape:- Early oval or pear shaped..

Developed:- Spindle shaped, Slendor body.

Size:- Early length 5-10 µm.Breadth

After developed:- Length2-3 um. & 15-20 μmBreadth 1-2 μm

Nucleus situated centrally kinetoplast lies transvesly near ant end.

Vacuole (Basal body): Lies infront of kinetoplast from which root of flagellum arises cosinophilic vacuole.Flagella may be of the same length as that of body or even longer projecting from the front.

Also read : IPC 🤕🤕🤕

Life cycle: Parasite has 2 stages in its lifeCycle:-

1)life cycle in man

2) Life cycle in sandfly (vector)

1) Life cycle in man:-

Mode of infection:- By vector sandfly. Infection of man by sandfly takes place during its blood meal. Thus promastigote from enters into circulation.Promastigote from via circulation enters into R.E organs, and settles there.In R.E.and increase in no.organs and promastigote multiply rapidly for binary fission. Few amastigote engulfed by neutrophil monocyte and thus entersinto circulation within these cells.2) Life cycle in sandfly:- Amastigesandfly during its blood meal.present in blood cells sucked byIn sandfly amastigote converted into promastigote in the gut of sandfly.These promastigote increase in no. rapidly by binary fission.These amastigote tend to spread towards ant. part of G.I tract of sandflyi.e. in pharynx and buccal cavity.This collection of promastigote in ant. end of sandfly is called as ant.station development (6th-9th day.)Now promastigote are waiting for chance for entry in human being whensandfly bites human entry of promastigote into them and cycle goes on.. Parasitology (ILS.C) 65