Intestinal Parasites I Flashcards Preview

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Flashcards in Intestinal Parasites I Deck (27):
1

Protazoa are unicellular _______

eukaryotes

2

Do Protozoa have cell walls? If not, what do they have?

NO! Cyst forms have a cyst wall

3

What are the 3 types of protozoan locomotory appendages

Cilia, flagella, pseudopodia

4

What are temporary, foot-like projections filled with cytoplasm in ______; mediate "crawling" over surfaces

These are Pseudopodia
Blank: amoeboids

5

What are hair-like projections typically cover the surface of _______; beat in waves that propels a cell

These are Cilia
Blank: ciliates

6

flexible, whip-like projections localized to specific areas on _________; movement of flagella propels a cell

These are flagella
Blank: flagellates

7

The motile, feeding, and proliferative form is called the ______

trophozoite

8

Most protozoa produce a ______ form in response to adverse environment stimuli

cyst

9

Purpose of cyst form?

Cyst encases trophs within a thick shell to protect from harsh conditions

10

Process of forming a cyst (enter)

Encystation

11

Process of leaving a cyst (exit)

Excystation

12

For many pathogenic protozoa, what is the infectious form?

Cysts

13

In fecal concentrates, _______ are damages and unrecognizable, _______ remain intact and are observable

trophs
cysts

14

What are three lab methods for detecting protozoa in stool specimen?

Antigen detection assays
Microscopic examination
Molecular methods

15

What is found more in formed stool?
What is found more in watery?

formed: cysts
watery: trophs

16

Why should more then 1 fecal specimen be examined?

because of intermittent shedding of parasites in stool

17

How should stool be collected for detecting protozoa

Three specimen over the period of 10 days

18

How long should you wait to preserve fecal specimens

Don't wait! Preserve immediately

19

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)

20

For microscopic examination of wet mount of preserved feces, what are usually destroyed and what remain intact

Trophs destroyed and cysts remain

21

What is an important component of light microscopes used in parasitology labs?

ocular micrometer

22

When making wet mounts, you should make two different types of mount on the same slide...what are they?

Saline mount and Iodine mount

23

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

24

Dried smears are usually stained with what?

trichrome stain

25

Stained smears should be first examined on low power and then use the _____________ objective

100x oil immersion objective (1000x total mag)

26

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)

27

What is the setback to Molecular Methods like Nucleic acid amplification test?

currently only available for detection of a limited number of intestinal protozoa