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ProtozoaPart II

Continously Lecture

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Class ZoomastigophoraLeishmania

• Leishmaniasis• 12 million people• Promastigote (above)

in insect vector• Amastigote in host

– Parasite in a macrophage (WBC)

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Sand Fly

• Vector for leishmaniasis

• Genus Phlebotomus

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Cutaneous Leishmaniasis

• Parasites form skin ulcers.

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As many as 200 lesions may form causing disability and social stigma

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Mucocutaneous Leishmaniasis

• Central & South America

• Destroys mucous membranes of nose & mouth

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Visceral Leishmaniasis Kala Azar

• Primarily occurs in Africa and Asia.

• Characterized by irregular fever, weight loss, swelling of spleen & liver, & anemia.

• Fatality can be 90% if untreated.

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Subphylum Sarcodina

• Pseudopodia• Phagocytosis

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Subphylum Sarcodina

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Subphylum Sarcodina Amoeba proteus

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Subphylum Sarcodina Entomoeba histolytica

• Amoebic dysentery• Transmitted by food &

water contaminated with cysts

• Bloody diarrhea

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Freshwater Amoeba

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Variations in Pseudopodia

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Subphylum Sarcodina Heliozoan

• Found most often in freshwater

• video

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Subphylum Sarcodina Foraminifera

• Secrete a shell of calcium carbinate

• Grow new chambers as organism increases in size– Foramen (opening)

between chambers• Shells constitute vast

deposits on ocean floors

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White Cliffs of Dover, England

• Foramifera deposits uplifted from ocean floor

• Chalk

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Pyramids of Egypt

• Made of limestone from foraminera

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Subphylum Sarcodina Foraminifera

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Phylum Apicomplexa• Apical complex

– Helps in penetrating host’s cells

• Endoparasites• Movement

– Male gamete• Male gametocyte

• Class Sporozoa– Plasmodium

• attacks red blood cells• malaria

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Malaria

• Most important parasitic disease of humans today

• WHO estimates that 270 million new cases occur annually with 2 million annual deaths

• Parasite - species of genus Plasmodium• Transmitted by bite of infected mosquitoes

of genus Anopheles

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Mosquito feeds on blood of infected host & ingests

gametocytes

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Gametes unite in mosquito stomach to form oocysts in wall

of stomach

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Oocysts

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Sporozoites produced in oocysts by sporogony move to salivary glands of mosquito &

are injected into next host

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Sporozoites invade liver cells and undergo schizogony to

produce merozoites

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Merozoites invade circulating RBCs

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Each merozoite produces as many as 36 new merozoites through schizogony in RBCs

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Merozoites rupture RBCs to invade other RBCs

Simultaneous lysing of RBCs causes the sudden chills & fever typical of malaria

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Gametocytes are produced in blood & ingested by mosquito to

complete the cycle

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Sporozoites from mosquito bite

Schizogony to make merozoites

Ingest gametocytes

Sporozoites to liver

Merozoites enter RBCs

Schizogony to make merozoites

Fertilization in stomach

Oocyst forms

Sporozoites by sporogony

Sporozoites invade salivary gland

Man Mosquito

Merozoites become gametocytesMerozoites become gametocytes Bites man

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Malaria control involves:

• Eliminating the vectors

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Malaria control involves:

• Reducing contact with the vectors

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Malaria control involves:

• Administration of anti-malarial drugs

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Phylum Cilophora

• Cilia for movement

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Ciliate (Paramecium)

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Trichocysts

• Released as a defense

• Long threadlike• Release triggered by

mechanical or chemical stimulation

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Phylum Cilophora Paramecium

• Movie

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Phylum CilophoraVorticella

• Spiral stock attaches to substrate– Contract and extend

• Cilia used to sweep food into mouth (see arrow)

• Movie

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Phylum CilophoraStentor

• Solitary• Use cilia to sweep

food into mouth• Movie

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Phylum Cilophora Didinium

• Bands of cilia• Eats Paramecium

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Phylum Cilophora Spirostoman

• Up to 3 mm long

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The End