An amoeba, often called an amoeboid, is a type of cell or unicellular organism which has the ability to alter its shape, primarily by extending and retracting pseudopods. Amoebae do not form a single taxonomic group; instead, they are found in every major lineage of eukaryotic organisms. Entamoeba histolytica is an anaerobic parasitic amoebozoan, part of the genus Entamoeba. Predominantly infecting humans and other primates causing amoebiasis, E. histolytica is estimated to infect about 35-50 million people worldwide. E. histolytica infection is estimated to kill more than 55,000 people each year

1. Entamoeba
histolytic
Prepared by: CJ T. Porras BSN 1-O

2. Introduction:
• E. histolytica was discovered by Losch in 1875
• It secretes proteinases that destroy proteins
• Entamoeba histolytica is an intestinal amoeba
• It destroys intestinal cells through direct-contact mechanism
• Amoeba formation, which forms pores in lipid bilayers of
infected cells
• Disrupts tight-junction proteins, resulting in increased
intestinal permeability

3. Morphology:
• E. histolytica shows three different stages:

4. Life Cycle:

5. Diagnostic Features:
• Only about 10% to 20% of people who are
infected with E. histolytica become sick from the
infection
• The symptoms are often quite mild and can
include loose feces (poop), stomach pain, and
stomach cramping

6. Mode of Transmission:
1. Faeco-oral route
2. Ingestion of cyst
contaminated foods and
water

7. Disease Produced:
Amebiasis

8. Pathology
and Symptomatology:
• The parasites express large number of virulence factors
including lectin, lytic peptide, cysteine, proteinases and
phospholipase.
• Excystation of cyst in intestine releases 4 trophozoites
• Trophozoites penetrates the columnar epithelium of mucosa
• Symptoms can include fulminating dysentery, bloody
diarrhea, weight loss, fatigue, abdominal pain, and
amoeboma.

9. Incubation Period:
2-4 weeks

10. Laboratory Diagnosis:
Stool macroscopy
Microscopy
Stool Ag detection
Stool culture
 Serology
PCR
Radiological finding
Blood test
Intradermal test

11. Treatment,
Prevention and Control:
Diloxanide fluorate, diidohydroxyquin,
rapamycin, metronidazole, imidazole,
paromomycin
4-aminoquinoline; for extra intestinal
infection
Oral rehydration

12. Entamoeba hartmanni

13. Introduction:
• Entamoeba hartmanni is a non-
pathogenic amoeba with worldwide
distribution
• Earlier considered as small race of E.
histolytica
• Inhabits the lumen of the large intestine
• It is not invasive
• Does not phagocytize GR, slow
displacement

14. Morphology:

15. Life Cycle:

16. Diagnostic Features:
• Presence of these organisms may imply host
consumption of fecally contaminated water or
food.
• Patients may rarely show
gastrointestinal symptoms such as loose
stools, colicky abdominal pain, and
flatulence

17. Mode of Transmission:
• similar to that of E. histolytica but it does not
have an invasive stage and does not ingest red
blood cells.
• organisms exists as a motile trophozoite and a
cyst. The cyst can survive outside the body and
can be transmitted to humans via ingestion of
contaminated food or water.

18. Disease Produced:
Amebic
Colitis

19. Pathology
and Symptomatology:
• Infections with E. hartmanni are typically
asymptomatic.
• Entamoeba hartmanni is a non-pathogenic amoeba
with worldwide distribution.
• Possess a certain pathogenicity as a causal agent of
mild diarrhea

20. Incubation Period:
2–4 weeks

21. Laboratory Diagnosis:
• Laboratory diagnosis is made by finding the
characteristic cysts in an iodine stained
• Stool examination for trophozoites and cysts

22. Treatment,
Prevention and Control:
• Metronidazole (750 mg three times daily for 5 days),
Tinidazole (1 g twice daily on 2 consecutive days), or a
Starch Placebo
• Proper hand hygiene and avoidance of contaminated food
and water

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