Entamoebae and Balantidium Flashcards
amoebae
protozoans that are able to change their shape, and feed by phagocytosis; found in soil and freshwater mainly
Entamoebae
obligatory parasites, which require an intestinal tract infection in host to survive!
3 Genera of Free-Living Amoeba
- Naegleria fowleri
- Acanthamoeba sp.
- Balamuthia sp.
these don’t need a host but can cause disease when they accidentally enter a host
Are entamoeba host specific?
yes
Entamoeba histolytica species
mainly humans, who act as a reservoir for dogs and cats
Entamoeba invadens species
reptiles
Unique aspect of E. histolytica cysts
the infective stage, has bluntly rounded chromatoidal bars
Characteristic E. histolytica appearance on histology?
Flask-shaped ulcers in the muscularis mucosa!
Best treatment for E. histolytica and invadens?
metronidazole
Why can’t the snake and the turtle go camping?
because turtles are commensal hosts for E. invadens but it’s super pathogenic in snakes
Free-living amoeba pathogenesis
inhaled into upper respiratory tract and migrate along olfactory nerves in the cranium
Acanthamoeba
spine like structures on weird trophozoites (looks like it has feet) and also causes a corneal ring of keratitis in the eye
Largest protozoan?
Balantidium
Balantidium
VERY common non-pathogenic protozoa that resides in the GI tract of pigs; concern is zoonotic transmission to humans (rare) via fecal-oral route
Unique aspect of Balantidium coli?
the trophozoite that is bean shaped ish is covered in cilia, and the cyst has refractive cilia (on the inside!)
life cycle is also completed in a single host
