Exercise No. 6c-1 PROTOZOA Phylum Sarcomastigophora - Subphylum Mastigophora

Question 1

Trophozoite: 9 to 12 µm long by 5 to l5 µm wide

Answer 1

Giardia lamblia

Question 2

Trophozoite: average size of 14 x 7 µm

Answer 2

Giardia lamblia

Question 3

Trophozoite: pyriform, pear-shaped or teardrop shaped

Answer 3

Giardia lamblia

Question 4

Trophozoite: rounded anterior

Answer 4

Giardia lamblia

Question 5

Trophozoite: tapering, pointed, attenuated posterior

Answer 5

Giardia lamblia

Question 6

Trophozoite: resembles the curved portion of a spoon if examined from the side

Answer 6

Giardia lamblia

Question 7

Trophozoite: dorsoventrally flattened

Answer 7

Giardia lamblia

Question 8

Trophozoite: dorsal side is convex and the ventral side is flat or concave

Answer 8

Giardia lamblia

Question 9

Trophozoite: anterior half of the ventral surface bears two sucking discs on each side

Answer 9

Giardia lamblia

Question 10

Trophozoite: bilaterally symmetrical with a pair of medial lines

Answer 10

Giardia lamblia

Question 11

Trophozoite: possesses two ovoid to spherical nuclei, located one in each of the sucking disc

Answer 11

Giardia lamblia

Question 12

Trophozoite: Each nucleus has a large karyosome, usually centrally located

Answer 12

Giardia lamblia

Question 13

Trophozoite: no peripheral chromatin

Answer 13

Giardia lamblia

Question 14

Trophozoite: Two slightly curved rodlike structures sit on the axonemes posterior to the nuclei

Answer 14

Giardia lamblia

Question 15

Trophozoite: four pairs of flagella that arise from the blepharoplasts

Answer 15

Giardia lamblia

Question 16

Trophozoite: One pair of the flagella projects from the the anterior end, another pair on the posterior end, and 2 pairs on the midportion extending laterally.

Answer 16

Giardia lamblia

Question 17

Trophozoite: propelled into a “falling leat” or “flipflop” motility

Answer 17

Giardia lamblia

Question 18

Trophozoite: “monkey face”

Answer 18

Giardia lamblia

Question 19

Trophozoite: “old man with eyeglasses”

Answer 19

Giardia lamblia

Question 20

used for attachment to the intestinal mucosa

Answer 20

sucking discs

Question 21

bilaterally symmetrical with a pair of medial lines dividing the trophozoite into 2 halves throughout most of its length

Answer 21

axostyles (or axonemes)

Question 22

Two slightly curved rodlike structures

Answer 22

parabasal bodies (or median bodies)

Question 23

Cyst: ovoid or ellipsoidal in shape

Answer 23

Giardia lamblia

Question 24

Cyst: 8 to 12 µm long by 7 to 10 µm wide

Answer 24

Giardia lamblia

Question 25

Cyst: surrounded by a tough hyaline cyst wall secreted from cytoplasm

Answer 25

Giardia lamblia

Question 26

Cyst: cytoplasm may retract from the cyst wall creating a clearing zone and a double wall appearance

Answer 26

Giardia lamblia

Question 27

Cyst: immature cyst contains two nuclei

Answer 27

Giardia lamblia

Question 28

Cyst: mature cyst has four

Answer 28

Giardia lamblia

Question 29

Cyst: axostyles lie diagonally forming a dividing line

Answer 29

Giardia lamblia

Question 30

Cyst: Remnants of the flagella and parabasal bodies are seen

Answer 30

Giardia lamblia

Question 31

Trophozoite: 5- 12 µm in diameter

Answer 31

Dientamoeba fragilis

Question 32

Trophozoite: slightly progressive motility

Answer 32

Dientamoeba fragilis

Question 33

Trophozoite: does not have flagella

Answer 33

Dientamoeba fragilis

Question 34

Trophozoite: characterized as having one (20 to 40%) or two (60 to 80%) nuclei

Answer 34

Dientamoeba fragilis

Question 35

Trophozoite: nuclear chromatin is usually fragmented into three to five granules

Answer 35

Dientamoeba fragilis

Question 36

Trophozoite: no peripheral chromatin on the nuclear membrane

Answer 36

Dientamoeba fragilis

Question 37

Trophozoite: has a hyaline ectoplasm

Answer 37

Dientamoeba fragilis

Question 38

Trophozoite: highly vacuolated endoplasm with ingested bacteria, yeast, and other debri

Answer 38

Dientamoeba fragilis

Question 39

possess characteristic serrate margins which sometimes give it a stellate appearance

Answer 39

broad hyaline pseudopodia

Question 40

Giardiasis can be diagnosed by identification of cysts or trophozoites of Giardia lamblia in stool by

Answer 40

direct fecal smears, concentration, or permanent staining

Question 41

Cysts of G. lamblia are found in

Answer 41

formed stools

Question 42

Cysts and trophozoites of G. lamblia are found in

Answer 42

diarrheal stools

Question 43

Often multiple specimens need to be examined and concentration techniques prior to reporting that a patient is free of Giardia.

Answer 43

Direct Microscopy: Stool examination

Question 44

This is done if the stool exam reveals negative results despite the clinical manifestations of giardiasis.

Answer 44

Examination of duodenal specimen

Question 45

Obtained by gastroduodenoscopy and examined microscopically as a wet preparation or permanent-stained smear

Answer 45

Duodenal aspirate

Question 46

another method for obtaining duodenal specimen

Answer 46

Enterotest® (HDC Mountain View, CA) or string test

Question 47

a gelatin capsule lined with silicone rubber that contains a spool of nylon string and a weight

Answer 47

Enterotest® (HDC Mountain View, CA) or string test

Question 48

The end of the string is taped to the back of the patient’s [?]

Answer 48

neck or cheek

Question 49

The patient then swallows the [?]

Answer 49

capsule with water

Question 50

The patient is not allowed to eat during this time but is allowed to [?]

Answer 50

drink a small amount of water

Question 51

As the capsule dissolves, the string unwinds and is carried by [?] to the duodenum, and the duodenal mucus adheres to the string.

Answer 51

peristalsis

Question 52

After about [?], the string is retrieved, and duodenal contents adherent to the string is scraped off and placed in saline on the slide for microscopic examination.

Answer 52

4 to 6 hours

Question 53

also used for detecting larvae of Strongyloides, eggs of liver flukes and oocysts of lsospora

Answer 53

Enterotest® (HDC Mountain View, CA) or string test

Question 54

A variety of immunodiagnostic methods, relying on detection of serum antibodies or antigens in feces, are in use.

Answer 54

Immunodiagnosis of Giardia lamblia

Question 55

have been used to demonstrate parasitic genome in the stool specimen containing Giardia lamblia

Answer 55

Deoxyribonucleic acid (DNA) probes and polymerase chain reaction (PCR)

Question 56

has only the trophozoite stage; Cysts have not been identified

Answer 56

Dientamoeba fragilis