Parasitology Flashcards
What is the definitive host in a parasitic infection?
The host where the parasite gains sexual maturity as well as reproducing inside of.
Wha is the intermediate host in a parasitic infection?
The host whereby the parasite develops and reproduces asexually
What is the paratenic host in a parasitic infection?
Not a part of the parasites life cycle but one that is used as a vehicle to get to the obligatory host
What is a protist?
referes to a single-celled colonial eukaryote other than fungi. Includes many diverse clades of algae and protozoa
What are protozoa?
Single celled heterotrophic protists
What are the features of protists?
flagella
undulating membrane
cysts- dormant stage w thick protective wall
kinetoplast- one large mitochondrion
pseudopods- projection of membrane and cytoplasm that allows movement and phagocytosis
Parasites -> protozoa –> Excavata
Within the excavata supergroup there metamonada and discicristata. What are the organisms/features associated with metamonada?
Giardia, trichomonas
Reduced mitochondria
pinocytosis
specialized structures used for species identification
intestinal parasites
form cysts
have cilia
Parasites -> protozoa –> Excavata
Within the excavata supergroup there metamonada and discicristata. What are the organisms/features associated with discicristata?
Naegleria, leishmania, trypanosoma
cytoskeleton
flat or disc shaped cristae in the mitochondria
can be free living or vector transmitted
Parasites -> protozoa –> Amoebozoa
Within the amoebozoa supergroup what are the organisms/features associated with it?
Acanthamoeba, balamuthia, entamoeba, endolimax, lodamoeba
Locomotion achieved by pseudopodia
Mitchondria with tubular cristae
Phagocytic
Form cysts
Parasites -> protozoa –> SAR
Within the SAR supergroup there apicomplexa (sporozoaans), Ciliophora, stramenopila. What are the organisms/features associated with apicomplexa?
Babesia, plasmodium, cryptosporidium, cyclosora, cystoisospora, sarcocystis, toxoplasma
-complex organelles in apical tip to penetrate host barriers
-adults have no cilia or flagella
-multiple forms
-pinocytosis
-alternate between sexual and asexual reproduction
-frequently intracellular
Parasites -> protozoa –> SAR
Within the SAR supergroup there apicomplexa (sporozoaans), Ciliophora, stramenopila. What are the organisms/features associated with ciliophora?
Balantidium coli
- cilia = locomotion
- only ciliate parasite in humans
- has macro- and micronucleus
- uses conjugation for sexual reproduction and binary fission for asexual reproduction
- Nutrition via ingestion through cytosome
- forms cysts
Of the parasitic worm family otherwise known as helminths, what are the distinguishing features of the Platyhelminths or “flatworms”?
Free living in water or damp soil
tissue acting like organs but no specialized respiratory, circulatory or digestrive tracts
gus is gastrovascular cavity –>ie single opening for intake and output
complex reproduction with many hermaphroditic species
Of the parasitic worm family otherwise known as helminths, what are the distinguishing features of the Trematodes or “flukes”?
complex life cycle with encysted egg stages and temporary larval forms
Multiple sucker devices => 1 for nutrition/waste and 1 for attachement
Will generally includea definitive host and intermediate host
When humans are the definitive hosts, fertilized eggs are excreted through feces and urine
-In water, eggs develop into ciliated larvae
–>Larvae then infect intermediate host (such as fish) to reproduce asexually and then escape to environment where they are picked up by the definitive host (human in this case)
—>evades host immunity by mimmicking host cell surface proteins
Of the parasitic worm family otherwise known as helminths, what are the distinguishing features of the Cestodes aka tapeworm?
infects all mammals and many other vertebrates
typically 2 hosts- hermaphroditic
most common source of human infection is the ingestion of cysts in undercooked meat
Live in intestines and can grow to meters in length
ribbon like body made of proglottids- reproductive units
–>once the proglottid/eggs are free they are able to spread through water
No GI tract absorb nutrition throughout their entire body
wasting disease => as worm load increases more nutrients are stolen from the host
Of the parasitic worm family otherwise known as helminths, what are the distinguishing features of the Nematode or roundworm?
Parasitize all plants and animals
mm to meters in length
covered in protective covering known as cuticle
have longitudinal muscles and separate sexes but no circulatory system
larvae resemble mini adults and grow via cell enlargement and mitosis
Wasting disease is what ultimately causes host damage via blockage
Cause nutritional deficiencies and muscle damage
