protozoa amoeba Flashcards
- Motile
- Reproducing
- Feeding stage
trophozoite
- Non-motile
- Nonfeeding stage
- Infective stage to
humans
cysts
- Cause dysentery
Entamoeba histolytica
Transmission of
amebae is generally by
ingestion of cysts in
fecally contaminated
food or water.
*Nucleus has karyosome (endosome)
Entamoeba histolytica
Mostly with RBC in cytoplasm
Entamoeba histolytica
- Cyst
- With chromatoid bars (rounded)
Entamoeba histolytica
amebiasis stage
cysts and trophozoite passed in feces
mature cysts ingested
excystation
trophozoite
multiplication
cyst or trophozoites
exits host
- Nonpathogenic
- Size: cyst = < 10um, trophozoite = < 12 um
Entamoeba hartmanni
*Cysts and trophozoites are morphologically
identical to E. histolytica
Entamoeba dispar
noninvasive
Entamoeba dispar
never ingests RBCs
Entamoeba dispar
Flask-shaped ulcerations of the intestinal wall and bloody
dysentery
pathology of E.histolytica
If amebae penetrate the intestinal wall and spread via
blood,
ulceration may occur in the liver, lungs, brain, or other
tissues.
pathology of E.histolytica
are most common and lung invasion usually
results from erosion of the liver abscess
- Liver abscesses
Any of these extraintestinal infections can be fatal.
pathology of E.histolytica
Transmission (Entamoeba histolytica)
- The infection can be transmitted sexually by
homosexual males
Transmission (Entamoeba histolytica)
one cause of the disease known a
“gay bowel syndrome.”
- Nonpathogenic
- Commonly confused with E. histolytica
Entamoeba coli
large eccentric karyosome
nucleus
e.coli
irregular peripheral chromatin clumping along the nuclear membrane
nucleus
e.coli
granular cytoplasm
trophozoite
e.coli
ingested bacteria but not RBCs.
trophozoite
e.coli
the pseudopods
e.coli
blunt
Motility in
e.coli
sluggish
up to 8 nuclei
* Chromatoid bars (splintered or pointed ends)
cyst stage
e.coli
- nonpathogenic
- found primarily in pigs and monkeys
- Occasionally in humans
Entamoeba polecki
resembles both E. histolytica and E. coli morphologically
Entamoeba polecki
- large glycogen
“inclusion mass”
- no cyst stage
Entamoeba gingivalis
usually 1 in mature cysts
* large glycogen “inclusion mass”
* Chromatoid bodies (abundant and are pointed)
nucleus
Entamoeba polecki
Nonpathogenic
*found in:
* mouth in soft tartar between teeth or in tonsillar crypts
* Occasionally in sputum
Entamoeba gingivalis
- only species to ingest white blood cells.
- (fragments in large vacuole)
Entamoeba gingivalis
