Protozoa Flashcards
Protozoa
single celled eukaryotes with nuclei
4 groups of protozoa based on locomotion
- flagellate
- amoeboid
- sporozoid
- ciliate
two forms a protozoa takes during life cycle
- cyst form
2. trophozoite form
cyst form
protects from desiccation, temperature and toxins
the normal infective stage
fecal/oral contamination moves cysts from host to host
trophozoite form
feeding stage
causing symptoms
motile
protozoa reproduction
asexually through budding, fission or shizogeny
schizogeny
parasite divides repeatedly in host cell to form many parasites that are eventually released
Mastigophora
(Archaezoa) Flagellate most primitive many lack mitochondria and Golgi Trypanosoma brucei Trypanosoma cruzi Giardia Trichonomas vaginalis
Trypanosoma brucei
African sleeping sickness
neurotoxins eventually reach CNS- treatment effective if before infection reaches brain
can alter surface antigens to escape detection by immune system
reservoir- lion, hyena, antelope
vector- tse tse fly
Trypanosoma cruzi
Chagas disease
chronic- death from heart failure
reservoir- opossum and armadillo
vector- reduviid bug
bug bites on lips, defecates near bite, scratching deposits feces into bite
Giardia
hikers diarrhea interferes with peristalsis Van Leeuwenhoek observed Giardia cysts in his own feces heart shaped with 2 nuclei cysts can survive up to 2 months
person to person by cysts/ personal contact
water, food contaminated by human or animal feces
boiling, filtering, chemicals (chlorine) required to kill cysts
Trichomonas vaginalis
infects female reproductive tract and male urinary tract
no cyst in life cycle
reservoir- human
transferred by intercourse
macrophages with CD4 receptors enter damaged area
Sarcodina
amoeboid
Entamoeba
Naegleria
Pseudopodia
Entamoeba histolytica
amoebic dysentery
can be extra intestinal (leaves digestive tract and enters body)
cysts transmitted in fecal contaminated water/food
10% world population infected with Entamoeba
Naegleria fowleri
causes amoebic meningitis
exists as part of normal flora in children
ameoba enters body through cuts, scrapes, conjunctiva during swimming in warm water
reaches brain through nasal passages