Nematollahi Lectures Flashcards
A close, long-term association between organisms of different species is called what?
Symbiosis
A symbiotic relationship in which one member benefits at the other member’s expense is called what?
Parasitism
Parasites that are unable to survive outside of its host are called?
Obligatory parasites
*Facultative can exist independent of host
Parasites that establish themselves inside the body are called?
Endoparasites
*Outside the body are ectoparasites
The host in which the adult or sexual phase of the parasite occurs is called what?
Definitive host
The host in which the larval or asexual phase of a parasite occurs is called what?
Intermediate host
When a host other than the normal host is harboring a parasite it is said to be?
Accidental/incidental host
When the host that harbors a parasite that infects humans it is said to be?
Reservoir host
Stage in the parasitic life cycle that is capable of invading a definitive host is called what?
Infective stage
Stage in the parasitic life cycle that can be identified by examining the specimen from the host is called?
Diagnostic stage
What are the 5 classes of Protozoa parasites?
1-Amoebas (Rhizopods) 2-Ciliates 3-Flagellates 4-Sporozoans 5-Apicomplexans
Which GI parasites move by pseudopodia, multiply by binary fission, are found in nature and are transmitted in water, food, sexually and on flies/cockroaches?
Amoebas
What are the two stages of the life cycles of most parasitic amoebas and flagellates?
1-Trophozoites (Pseudopod motility, feeding, find in diarrheal stool, non infectious)
2-Cysts (nonmotile, protected by cyst wall, infectious)
What are the 5 parts of the life cycle of an intestinal amoeba?
1-Host ingests infective cysts 2-Cysts excyst in GI tract to form trophozoite 3-Toph multiplies (binary fission) 4-Troph encysts 5-Host excretes cysts in stool
What are 4 things you should look at when identifying Trophozoites?
1-Size (micrometer)
2-Arrangement of chromatin
3-Clean vs dirty cytoplasm
4-Presence/absence of inclusions
What are 4 things you should look at when identifying cysts?
1-Size (micrometer)
2-Shape
3-# of nuclei
4-Presence/absence of chromatoid bodies or other inclusions
What two species of amoebas are the main pathogens?
1-Entamoeba histolytica (only in genus)
2-Dientamoeba fragilis
Which amoeba is the only to have RBC inclusions, causes dysentery, is transmitted by food and water, and can be asymptomatic?
Entamoeba histolytica
*8-65 um troph, 8-22 um cyst. cysts viable for 30 days
Which amoeba is actually a flagella but occurs as an amoeba with wide pseudopodia, doesn’t have a cyst stage and causes diarrhea, abdominal pain, etc.?
Dientamoeba fragilis
The only known ciliate parasite of humans, which pathogen is transmitted by food and water and causes balantidiasis?
Balantidium Coli
*largest protozoa in humans
What are the three main flagellate pathogens?
1-Dientamoeba fragilis
2-Giardia duodenalis (aka. G. lamblia, G. intestinalis)
3-Trichomonas vaginalis
Which pathogen is in streams and ponds, has two haploid nuclei (old man with glasses) is transmitted fecal/oral route and causes Giardiasis?
Giardia Duodenalis (aka. G. Lamblia, G. intestinalis)
*very relictual flagellate (diplomonadida)