Parasites Flashcards
What is symbiosis?
the intimate living together of two dissimilar organism in a mutually beneficial relationship
Amoebas
trophozoites move by pseudopodia. multiply by binary fission. most are non-pathogenic
What is a trophozoite?
- motile
- sensitive to environment
- feeding
- reproducitve stage
- find in diarrheal stools
- noninfection
What is a cysts?
- nonmotile
- protected by cyst wall
- resistant to environment
- non feedin-nonreproductive
- infectious
Entamoeba histolytica
Transmission
- food and water
- survive in environment for weeks/months
- humans are primary known reservoir
- sexual
- domestic mammals, nonhuman primates, cockroaches
Disease
- dysentery
- pulmonary abscesses, can cough up in sputum
- can cause liver damage
Entamoeba gingivalis
- opportunistic oral pathogen
- lives in the gingival pockets
Giardia lamblia
-found in streams/ponds world wide
transmission
-fecal oral
areas of poor sanitation or personal hygiene
-beavers appear to be a source
Disease
- diarrheal disorder that affects the small intestine directly
- stool is watery early and then becomes foul smelling and can float
Trichomonas Vaginalis
Disease
- trichomoniasis
- indicative of pH imbalance in women
- causes purulent discharge, itching, burning, can complicate pregnancy
- men are usually asymptomatic
- transmission: sexual
- found in male prostrate and urethra
Crytosporidium Parvum
Transmission
- contaminated food and water, including recreational water
- zoonosis: spread animal to animal
- Resists chlorine and ozone treatment
Cytptosporidiosis
- mild, self-limiting, watery diarrhea without blood
- remission in approx. 10 days
- AIDS patients are encouraged to boil or filter their drinking water
Toxoplasma Gondii
causes toxoplasmosis which resembles a mild cold or mono; caused by ingesting cysts found in uncooked pork or lamb or cat feces; sexual reproduction occurs in cat intestine; can cross placental barrier
Pneumocystis carinii
This causes pneumonia in immunocompromised patients and is often fatal
Balantidium coli
This is the largest protozoan parasite in humans; it is a ciliated protozoan than can cause nausea, vomiting, and bloody stools
Characteristics of Helminths
- tapeworm (cestode)
-head with flat segmented body
hermaphrodites - Fluke (trematode)
-leaf-shaped with oral and ventral suckers
-most hermaphrodites
-Separate sexes: blood flukes (schistosoma)
-Blind - Foundworm (nematode)
-spindle shaped
-separate sexes
-tubular
Cestodes (tapeworms)
Cysticercosis
- infects both humans and pigs (tania sodium)
- greatest concern is cerebral cysticercosis –> neurological defects
- absorb nutrients through outer segment
- ribbon-shaped worms
- Tanea saginata (beef)
- Tanea Solium (pork)
Trematodes (flukes)
- leaf shaped flat worm
- have mouth and intestinal track
- include blood flukes and lung flukes
- Blood: Schistosoma spp.
- Lung: Paragonimus westermani
