Flashcards in Intestinal Parasites I Deck (27):
Protazoa are unicellular _______
Do Protozoa have cell walls? If not, what do they have?
NO! Cyst forms have a cyst wall
What are the 3 types of protozoan locomotory appendages
Cilia, flagella, pseudopodia
What are temporary, foot-like projections filled with cytoplasm in ______; mediate "crawling" over surfaces
These are Pseudopodia
What are hair-like projections typically cover the surface of _______; beat in waves that propels a cell
These are Cilia
flexible, whip-like projections localized to specific areas on _________; movement of flagella propels a cell
These are flagella
The motile, feeding, and proliferative form is called the ______
Most protozoa produce a ______ form in response to adverse environment stimuli
Purpose of cyst form?
Cyst encases trophs within a thick shell to protect from harsh conditions
Process of forming a cyst (enter)
Process of leaving a cyst (exit)
For many pathogenic protozoa, what is the infectious form?
In fecal concentrates, _______ are damages and unrecognizable, _______ remain intact and are observable
What are three lab methods for detecting protozoa in stool specimen?
Antigen detection assays
What is found more in formed stool?
What is found more in watery?
Why should more then 1 fecal specimen be examined?
because of intermittent shedding of parasites in stool
How should stool be collected for detecting protozoa
Three specimen over the period of 10 days
How long should you wait to preserve fecal specimens
Don't wait! Preserve immediately
Antigen detection assays work well for detecting protozoa but what is the disadvantages to them?
Only for a limited number of organisms (the common ones: Giardia, Cryptosporidium, Entamoeba)
For microscopic examination of wet mount of preserved feces, what are usually destroyed and what remain intact
Trophs destroyed and cysts remain
What is an important component of light microscopes used in parasitology labs?
When making wet mounts, you should make two different types of mount on the same slide...what are they?
Saline mount and Iodine mount
Smears of preserved, concentrated stool are made on a slide. Many modern fixatives permit specimen adherence to slide. How do you make this slide?
Use applicator stick (up and down motion) to make thick and thin areas
Dried smears are usually stained with what?
Stained smears should be first examined on low power and then use the _____________ objective
100x oil immersion objective (1000x total mag)
What are three other methods besides trichrome to stain smears?
Modified acid-fast stain (cryptosporidium spp and coccidia)
Modified safranin stain (cyclospora cayetanensis)
Chromotrope R2 / modified trichrome (microsporidia)