WEEK 3.1 AMOEBA Flashcards
Entamoeba histolytica
Pathogenic
Entamoeba dispar
- Entamoeba hartmanii - Entamoeba coli - Entamoeba gingivalis
- Entamoeba polecki - Entamoeba moshkovskii - Endolimaxnana
- Iodamoeba butschii - Blastocystis hominis
Non Pathogenic
Negleria fowleri
- Acanthamoeba spp.
Pathogenic
and Free- Living
Balantidium coli
Ciliata
Dientamoeba fragilis
Other int. protozoan
2 Stages of Development
Cyst and Trophozoite
Non-motile, non-Feeding stage, Resistant to acid
Trophozoite
development of cyst into trophozoite
Excystation
development of trophozoite into cyst
Encystation
mode of reproduction of trophozoite
Binary Fission
All amoeba are commensal except for
Entamoeba histolytica.
With pseudopodium (false feet)
finger-like structures for movement
Undergoes ENCYSTATION except for
E. gingivalis and Dientamoeba fragilis
Inhabits the large intestine except
E. gingivalis (gums)
presence of amoeba in any part ofthe body (exclusively applied to E. histolytica)
Amoebiasis
divides through “binary fission”, irregular in shape, motility: unidirectional, flask-shaped ulcers
Trophozoite
1 to 4 nucleus, cigar/rod shaped chromatoidal body, centrally located karyosome.
Cyst
Infective stage of E. histolytica
Tetranucleated/mature cyst
MOT of E. histolytica
ingestion of contaminated food and/or water with E. histolytica cyst
Vegetative and motile stage (Feeding stage)
Trophozoite
Found in watery, soft, or semi-formed stool
Trophozoite
Fragile
Trophozoite
Non-motile, non- feeding stage
Cyst
Found in soft to formed stool
Cyst
Resistant to acidic pH
Cyst
- Gradual onset of abdominal pain
- Diarrhea (with or without blood and mucus)
- In children, bloody diarrhea, fever and abdominal pain
- Abscess formation → Amoebic liver abscess
Symptoms of E. histolytica
The presence of Charcot-Leyden crystals was found microscopically in the stool in cases of
Amoebic dysentery
Amebic colitis / Amebic dysentery: Abdominal pain, diarrhea (with or without mucus and blood)
Intestinal Amebiasis
Ameboma-mass like lesion with abdominal pain and dysentery (<1%)
Characteristic Ulcer: FLASK-SHAPE ULCER