13 - Intro to enteric protozoa Flashcards
enteric protozoa are found in
human GI
status of enteric protozoa May be
depending on species:
- commensal
pathogen
asymptomatic carriage of pathogen
routes protozoa can be transmitted to humans by
direct
faecal-oral
vector-borne
predator-prey
direct transmission
body contact such as sexual
eg. trichomonas vaginalis
faecal-oral transmission
in food and water, sometimes sexual
eg. entamoeba histolytica, giardia intestinalis
vector-borne transmission
blood sucking anthropoids
eg. plasmodium spp.
trypanosoma spp.
leishmania spp.
predator-prey transmission
in animal tissue eaten by a carnivore
eg. toxoplasma gondii
sarcocystis spp.
enteric protozoa are transmitted by
faecal oral route
most enteric protozoa have a life cycle involving
trophozoites and cysts
cysts are shed in the faeces and enable the protozoan to survive in the environment
trophozoites emerge from cysts after ingestion by the host. they live in the intestine where pathogenic species causes disease
faecal protozoa are common in
underdeveloped countrys where hygiene and lack of access to clean water are poor
4 groups of protozoa
- amoebae
- flagellates
- ciliates
- sporozoans
amoebae
move by means of pseudopodia
entamoeba histolytica is a pathogen
flagellates
move by long, whiplike flagella
pathogens are
giardia intestinalis, dientamoeba fragilis
trichomonad vaginalis is not an enteric protozoan but is a flagellate
ciliates
propelled by rows of cilia
pathogens are balantium coli
sporozoans
lack specialised organelles of motility pathogens are sarcocystis spp. isospora belli cryptosporidium parvum cyclospora cayetanensis microsporidium spp.
