Hemoflagellates:Leishmania spp.

University of SulaimaniUniversity of SulaimaniCollege of ScienceCollege of Science

Department of BiologyDepartment of Biology

University of SulaimaniUniversity of SulaimaniCollege of ScienceCollege of Science

Department of BiologyDepartment of Biology

PracticalPractical ParasitologyParasitology22ndnd stage stage

Lab 8 : LeishmaniasisLab 8 : Leishmaniasis

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Objectives: Students should be able to:

1.List human pathogenic species of Leishmania

2.Identify amastigote stage.3.Describe methods of diagnosis of

Leishmania spp.

Leishmania spp.

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The leishmaniasis is a group of vector-borne diseases caused by protozoan

haemoflagelates of the genus LeishmaniaIt is spread through females of Sandflies of the genus Phlebotomus spp. in the Old World, and of the genus Lutzomyia in the

New World.Leishmaniasis is a zoonotic deadly parasitic disease that affects over 12 million people worldwide, with 350 millions are at risk.With more than 2 million new cases reported every year.

Leishmania spp.

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Leishmania spp.

Phlebotomus 4

Leishmania spp.In 1901, professor William B. Leishman (Scotish Pathologist), identified certain organisms in smears taken from the spleen of a patient who had died from “Dum-Dum fever".This disease was similar to what Indian physicians called kala-azar (black fever). Initially, these organisms were considered to be trypanosomes.

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Leishmania spp.In 1903, Captain Charles Donovan described them as being new. These new microorganisms were given the name ‘Leishman-Donovan bodies’ After that taxonomically designated Leishmania donovani.

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Amastigote. (Leishmanial form)

Spherical or Oval in shape 2-3 μm in diameter.non-motile Large eccentrically located nucleus Rode shape KinetoplastUsually found in the vertebrate host.

Leishmania spp.

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• A macrophage filled with Leishmania amastigotes.

Leishmania spp.

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Promastigote: (Leptomonad stage)Spindle shaped with 14-20 by 1.5 - 4 μm in diameterFree anterior flagellumKinetoplast at the anterior end of the body.There is no undulating membrane.Usually promastigote found in female Sandflies and Culture

Leishmania spp.

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In humans, There are different forms of this disease :Visceral leishmaniasis: involving liver, spleen, and bone marrow Cutaneous leishmaniasis: involving the skin at the site of a sandfly bite mucocutaneous leishmaniasis: involving mucous membranes of the mouth and nose after spread from a nearby cutaneous lesion (very rare).

Leishmania spp.

Different species of Leishmania cause different forms of disease

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Leishmania donovaniVisceral leishmaniasis (VL)• Most severe form of the disease,

usually fatal if left untreated• Usually associated with fever,

weight loss, and an enlarged spleen and liver.

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G.D. Asia, Africa and south America and can affect people of all ages

90% of all visceral leishmaniasis occurs in Bangladesh, Brazil, India, Iraq and the Sudan

•2893 cases were reported in Iraq in 2001•12 visceral leishmania cases were reported in Americans in Desert Storm.

Leishmania donovani

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Visceral leishmaniasis (VL)

Habitat:- internal organ (liver, lymph nodes, spleen ,bone marrow)Disease Visceral leishmaniasis, Kala azar, Dum Dum feverTransmission VL. is transmitted chiefly by female Sandflies (Phlebotomus spp.)

Leishmania donovani

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Visceral leishmaniasis (VL)

Leishmania tropica Cutaneous leishmaniasis (CL)

• Most common form• Characterized by one or more sores, or

nodules on the skin• Sores can change in size and appearance

over time• Often described as looking somewhat like

a volcano with a raised edge and central crater

• Sores are painless or painful.

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• Most sores develop within a few weeks of the sandfly bite, however they can appear up to months later

• Skin sores of cutaneous leishmaniasis can heal on their own, but this can take months or even years

• Sores can leave significant scars and be disfiguring if they occur on the face

Leishmania tropica

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Cutaneous leishmaniasis (CL)

G.D. in Asia, Africa, and Mediterranean90% of cutaneous leishmaniasis occurs in Afghanistan, Iran, Iraq, Saudi Arabia, Syria, Brazil and Peru

•8,779 cases were reported in Iraq in 1992•At least 20 cases of cutaneous leishmaniasis were reported in Americans from Desert Storm

Leishmania tropica

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Cutaneous leishmaniasis (CL)

Habitat:- SkinDisease Cutaneous leishmaniasis, Oriental sore, Delhi or Baghdad boilsTransmission female Sandflies (Phlebotomus sp.)

Leishmania tropica

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Cutaneous leishmaniasis (CL)

Multiple lesions on arm with a variety of appearances.

Leishmania tropica

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Cutaneous leishmaniasis (CL)

Note the raised border and wet appearance of the sore on the back of the hand.

Both lesions are leishmaniasis.

Leishmania tropica

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Cutaneous leishmaniasis (CL)

Back of hand.Note raised border and wet appearance. Patient has bacitracin ointment applied to lesion.

Leishmania tropica

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Cutaneous leishmaniasis (CL)

Small, raised lesion on trunk.

Leishmania tropica

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Cutaneous leishmaniasis (CL)

Upper Eyelid. Note the dry, crusted appearance which is different than previous sores shown.

Leishmania tropica

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Cutaneous leishmaniasis (CL)

Three lesions on face. Raised and dry. Another different presentation.

Leishmania tropica

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Cutaneous leishmaniasis (CL)

Leishmania braziliensisMucocutaneous Leishmaniasis Mucocutaneous Leishmaniasis

(MCL)(MCL)

• This type occurs if a cutaneous lesion on the face spreads to involve the nose or mouth

• May occur months to years after original skin lesion

• Lesions can be very disfiguring

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Leishmania braziliensis

G.D. In South and Central America (Brazil, Bolivia, and Peru)   Habitat:- Skin and mucosa Disease mucocutaneous leishmaniasis, espundia, Uta, American leishmaniasisTransmission: female Sandflies Lutzomyia

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Mucocutaneous Leishmaniasis Mucocutaneous Leishmaniasis (MCL)(MCL)

Leishmania braziliensis

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Mucocutaneous Leishmaniasis Mucocutaneous Leishmaniasis (MCL)(MCL)

Life Cycle

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Laboratory Diagnosis:1.Microscopy: (slit-skin smear, splenic aspirate, liver

biopsy or bone marrow biopsy). Examination of Giemsa and Leishman stained slides of the relevant tissue is still the technique most commonly used to detect the parasite.

2. Culture: The aspirates can be cultured in NNN. In

culture the amastigote stage converts to the promastigote stage. However, this is not a rapid technique, as the parasites may take from 10 - 21 days to grow.

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3. Serodiagnosis:VL produces large amounts of specific IgG

which can be used for diagnosis. Currently the most used serodiagnostic tests Enzyme Linked Immunosorbent Assay (ELISA).

4. Molecular techniques: PCR, such technique, however, are not readily available in general diagnostic laboratories.

Laboratory Diagnosis:

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Promastigotes from culture.

Amastigotes from blood.

ReferencesReferences

1. Schmidt GD, & Roberts LS. (2005). Foundations of Parasitology. 7th ed. McGraw Hill. Boston.

2. Gillespie S, & Pearson RD. (2001). Principles and Practice of Clinical Parasitology. John Wiley & Sons Ltd. Chichester.

3. Singh RK, Pandey HP, Sundar S. (2006 ). Visceral leishmaniasis (kala-azar): challenges ahead. Indian J Med Res. 123(3):331-44.

4. Soto J`, et al. (2001).Treatment of American cutaneous leishmaniasis with miltefosine, an oral agent. Clin Infect Dis. 33(7):57-61.

5. http://www.cdc.gov/parasites/leishmaniasis/6. http://www.cdfound.to.it/7. http://www.stanford.edu/class/humbio103/ParaSites2006/

Leishmaniasis/Mucocutaneous.htm

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Next LabApicomplexa: Tissue Apicomplexa

Toxoplasma gondii

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