PROTOZOA

PROTOZOA

PROTOZOA

Presented By:Dr. Shaymaa AbdalalMedical Parasitology Demonstrator INTESTINAL PROTOZOA

INTESTINAL PROTOZOA

Numerous protozoa inhabit the gastro-intestinal tract of humans .

Entamoeba histolytica can become a highly virulent and invasive organism that causes a potentially lethal systemic disease.

Giardia lamblia can cause severe acute diarrhea which may lead to a chronic diarrhea and nutritional disordersINTESTINAL PROTOZOA

Intestinal protozoa are transmitted by the fecal-oral route .

exhibit similar life cycles consisting of a cyst stage and a trophozoite stage INTESTINAL PROTOZOA

www.tulane.eduGiardia lamblia Giardia lamblia Disease:GIARDIASIS

Distribution:worldwide distribution and is the most common protozoan isolated from human stools.

Giardia lamblia Definitive host : man

Habitat: upper portions of the small intestine.

Infective stage: cysts.

Giardia lamblia trophozoiteGiardia lamblia trophozoiteCharacteristic features :Two nuclei (Nu).Central karyosomes (k).median bodies (MB). Axonemes (Ax) .Four pairs of flagella (Fg).An adhesive disk (AD).

www.tulane.edu/~wiser/protozoology/notes/intes.htmlGiardia lamblia trophozoiteMorphology:

Size : 12-15 X 5-10m.

Shape: Pear or Tear Drop

www.tulane.edu/~wiser/protozoology/notes/intes.htmlGiardia lamblia trophozoite

Giardia lamblia cystGiardia lamblia cystCharacteristic features :

Four nuclei (Nu).Axonemes (Ax) .Median bodies (MB).Well-defined wall (CW)

Giardia lamblia cystMorphology :

Size : 11-14X 6-10m.

Shape: Oval

Giardia lamblia cyst

Entamoeba histolytica Entamoeba histolytica Disease:amebiasis or amebic dysentery.

Distribution:found throughout the world, they are more common in tropical countries or other areas with poor sanitary conditions.

Entamoeba histolytica Definitive host : man

Habitat: large intestine.

Reservoir: no animal reservoirs.

Infective stage: cysts.

Entamoeba histolytica trophozoite Entamoeba histolytica trophozoite Characteristic features :

a finger-like pseudopodium (psd) . the ectoplasm (ecto). cytoplasm has a granular appearance the endoplasm (endo).a glycogen vacuole (vac).Nuclear (Nu).chromatin and a centrally located karyosome (ka).

Entamoeba histolytica trophozoite Morphology :

Size : 15-30 m.

Shape: an amorphous shape .

Entamoeba histolytica trophozoite

Entamoeba histolytica cyst Entamoeba histolytica cyst Characteristic features :

Chromatoid bodies (cb) .1-4 nuclei (Nu).a glycogen vacuole (vac) .

Entamoeba histolytica cyst Morphology :

Size : 12-15 m.

Shape: spherical shape .

Entamoeba histolytica cyst

MalariaMalariaMalaria is the 5th cause of death from infectious diseases worldwide (after respiratory infections, HIV/AIDS, diarrheal diseases, and tuberculosis) in low-income countries.

Malaria is the 2nd leading cause of death from infectious diseases in Africa, after HIV/AIDS.

MalariaDisease:Malaria

Distribution:Malaria today is usually restricted to tropical and subtropical areas MalariaIntermediate Host: man

Vector (Definitive host) : femaleAnopheles mosquito

habitat: RBC`s

Infective stage: sporozoites .

P. vivaxP. vivaxP. Vivax ring stageP. Vivax ring stage

Diagnostic Points: Red cells containing parasites are usually enlarged.

Schuffner's dots are frequently present in the red cells as shown above.

The mature ring forms tend to be large and coarse.

Developing forms are frequently present.

P. Vivax schizont stageP. Vivax schizont stageschizonts of P. vivax are large and amoeboid.Schizont large may almost fill the RBC`s.Mature = 12 to 24 merozites.

P. falciparumP. falciparum

P. falciparum ring stageP. falciparum ring stageDiagnostic Points:

Red Cells are not enlarged. Rings appear fine and delicate and there may be several in one cell. Some rings may have two chromatin dots. Presence of marginal or applique forms. No Trophosoite and schizont.

P. falciparum gametocyte stageP. falciparum gametocyte stage

Gametocytes of P. falciparum. Figs. 27-28:Macrogametocytes (female); Figs. 29-30: Microgametocytes (male).Illustrations from: Coatney GR, Collins WE, Warren M, Contacos PG. The Primate Malarias.Bethesda: U.S. Department of Health, Education and Welfare; 1971.P. falciparum gametocyte stagecrescent- or sausage-shaped.

1.5 times the diameter of an RBC in length.

remnants of the host RBC can be seen; this is often referred to as Laveran's bib.

P. falciparum gametocyte stageGametocyte of P. falciparum in a thin blood smear, showing Laveran's bib.

Key Morphological Differences Falciparumvivaxnumerous rings

smaller rings

no trophozoites or schizonts

cresent-shaped gametocytes

enlarged erythrocyte

Schffner's dots

'ameboid' trophozoite

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