Lecture 6 - Protozoa Flashcards
what are protozoa?
one celled eukaryotes
what are protzoan cysts?
cysts are tough protective layers outside of the cytoplasmic membrane of the protozome
it is used for protection from inhospitable environments (i.e. protecting the cell not explode in hypotonic environments)
what are trophozites?
the growing form of many protozoan species (has no cyst wall)
what are oocysts?
a cyst containing a zygote (fertilized egg)
if a oocyst enters the body, the egg will just grow into adult form and then lay more eggs within the body
Entamoeba histolytica
- can be contracted as a cyst or trophozoite
- caused ameobic dysentery (diarrhea), flask shaped ulcers
- Does this by eating Red Blood Cells from the intestinal wall
- Transmitted fecal-orally (through the water)
- is treatable
Giardia lamblia
“beaver fever”
- can be contracted as a cyst or trophozoite
- causes intestinal upsets, flatulence, nausea, abdominal cramping, and diarrhea
- does this by staying in the small intestine and taking up all the nutrients
- transmitted fecal-orally
- is treatable
Trichomonas vaginalis
“trich”
- is only contracted as a trophozoite, therefore it does not have protection against the environment and will dry out super quickly
- causes intense itching, and inflammation of tissues
- it does this by irritating the vaginal and male urethra
- it is transmitted sexually (mucous membrane to mucous membrane)
- can be treated
Acanthamoeba sp.
- it is contracted as a cyst but grows to be a trophozoite in the body
- it gets in the microscopic abrasions in the eye and then grows in the person’s eye
- does this by getting into un-sterile contact solution like tap water or settling in dust
- transmitted via cysts in tap water or dust
- treatment would be corneal transplants if its quick but if not, its loss of eye
Cryptosporidium parvum
- contracted as a oocyst
- causes chronic diarrhea in immunocompromised and severe diarrhea for immunocompetent
- does this by existing in the intestinal tissue and causing an intestinal lining infection
- transmitted fecal-orally (found in lakes, and unfiltered water)
- no good treatment available
Toxoplasma gondii
- contracted as an oocyst
- causes death and fetal complications for pregnant women
- does this by having its lifecycle (reproductive) in a cat and then being pooped out into their litter box; it can also be in undercooked meat
- transmitted fecal-orally
- not treatable
Trypanosoma (2 types)
- T.brucei gambienese/T. brucei rhodesiense
- causes African sleeping sickness
- transmitted by Tsetse fly (vector) - T.cruzi
- causes Chaga’s Disease (~10% cardiac mortality)
- transmitted by Reduviid bug (kissing bug)
Leishmania sp.
- transmitted via sandfly
- cause visceral, cutaneous and mucocutaneous syndromes (can eat away cartilage)
- does this by living and developing in macrophages (immune cells)
Plasmodium sp.
- transmitted by female Anopheles mosquito
- mosquito carries sporozoite (trophozoite) in its saliva
- can cause a range of diseases depending on the type of Plasmodium species but P.falciparum causes malaria
- does this by entering the blood stream and then the liver cells within 30 minutes (site of infection is in the liver)
- no clear treatments yet
5 types of Plasmodium species
- P. falciparum (most dangerous type) [eats any age RBC]
- P. malariae [eats only old RBC]
- P.ovale
- P.vivax [eats newly produced RBC]
- P.knowlesii (monkey malaria)
What are the symptoms of P.falciparum?
fever and chills cause by the release of toxic breakdown products when red blood cell’s rupture (because it goes in them and eats them) and the release of parasite
