Intestinal Parasites I

Question 1

Protazoa are unicellular _______

Answer 1

eukaryotes

Question 2

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

Answer 2

NO! Cyst forms have a cyst wall

Question 3

What are the 3 types of protozoan locomotory appendages

Answer 3

Cilia, flagella, pseudopodia

Question 4

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

Answer 4

These are Pseudopodia

Blank: amoeboids

Question 5

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

Answer 5

These are Cilia

Blank: ciliates

Question 6

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

Answer 6

These are flagella

Blank: flagellates

Question 7

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

Answer 7

trophozoite

Question 8

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

Answer 8

cyst

Question 9

Purpose of cyst form?

Answer 9

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

Question 10

Process of forming a cyst (enter)

Answer 10

Encystation

Question 11

Process of leaving a cyst (exit)

Answer 11

Excystation

Question 12

For many pathogenic protozoa, what is the infectious form?

Answer 12

Cysts

Question 13

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

Answer 13

trophs

cysts

Question 14

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

Answer 14

Antigen detection assays
Microscopic examination
Molecular methods

Question 15

What is found more in formed stool?

What is found more in watery?

Answer 15

formed: cysts
watery: trophs

Question 16

Why should more then 1 fecal specimen be examined?

Answer 16

because of intermittent shedding of parasites in stool

Question 17

How should stool be collected for detecting protozoa

Answer 17

Three specimen over the period of 10 days

Question 18

How long should you wait to preserve fecal specimens

Answer 18

Don’t wait! Preserve immediately

Question 19

Antigen detection assays work well for detecting protozoa but what is the disadvantages to them?

Answer 19

Only for a limited number of organisms (the common ones: Giardia, Cryptosporidium, Entamoeba)

Question 20

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

Answer 20

Trophs destroyed and cysts remain

Question 21

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

Answer 21

ocular micrometer

Question 22

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

Answer 22

Saline mount and Iodine mount

Question 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?

Answer 23

Use applicator stick (up and down motion) to make thick and thin areas

Question 24

Dried smears are usually stained with what?

Answer 24

trichrome stain

Question 25

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

Answer 25

100x oil immersion objective (1000x total mag)

Question 26

What are three other methods besides trichrome to stain smears?

Answer 26

Modified acid-fast stain (cryptosporidium spp and coccidia)
Modified safranin stain (cyclospora cayetanensis)
Chromotrope R2 / modified trichrome (microsporidia)

Question 27

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

Answer 27

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