Exam II - Phylum Sarcomastigophora

Question 1

What are the final hosts for Trypanosoma cruzi?

Answer 1

dogs, cats, & humans

Question 2

How would you identify Trypanosoma cruzi?

Answer 2

trypomastigote in blood smear

trypomastigote in blood smear is elongated, spindle or leaf shaped, 20µm long

Question 3

Which end would be the anterior end?

Answer 3

A

Question 4

What is the common name of the condition caused by Trypanosoma cruzi?

Answer 4

Chagas’ disease

Question 5

What is/are the site(s) of infection for Trypanosoma cruzi?

Answer 5

cardiac & smooth muscle, blood

Question 6

Where for Trypanosoma cruzi amastigotes cause pathogenesis?

Answer 6

heart muscle

Question 7

Which animals are most susceptible to Chagas’ disease?

Answer 7

puppies & kittens

Question 8

What is the infective stage of Trypanosoma cruzi?

Answer 8

trypomastigote

Question 9

Which diagnostic method(s) are used to diagnose Trypanosoma cruzi?

Answer 9

• blood smear
• xenodiagnosis

Question 10

Describe the treatment options available for Trypanosoma cruzi

Answer 10

there is no satisfactory treatment known

Question 11

What form of locomotion do both Giardia & Trypanosoma utilize?

Answer 11

pseudopodia and/or flagella

Question 12

What is/are the host(s) for Giardia intestinalis?

Answer 12

dogs, cats, cattle

possibly humans?

Question 13

Describe the appearance of Giardia intestinalis trophozoites

Answer 13

Trophozoites are 21 um long, teardrop, 2 nuclei, 8 flagella, face-like appearance

Question 14

Describe the appearance of Giardia intestinalis cysts

Answer 14

Cysts are 12 um long, ovoid, 4 nuclei

Question 15

Describe the life cycle of Giardia intestinalis

Answer 15

Trophozoites adhere to the small intestine and multiply asexually. After several replications, a trophozoite encysts. Cysts pass down the small intestine and are passed in the feces. These are the infective form.

Cysts survive for 2-4 weeks. PPP is 1-2 weeks.

Question 16

What is the infective form of Giardia intestinalis?

Answer 16

cyst

Question 17

What is the PPP for Giardia intestinalis?

Answer 17

1-2 weeks

Question 18

What is/are the site(s) of infection for Giardia intestinalis?

Answer 18

Small intestine

Question 19

Describe any pathogenesis associated with Giardia intestinalis

Answer 19

Many infections are asymptomatic. Trophozoites can cause an acute focal inflammation

Question 20

What are some clinical signs associated with Giardia intestinalis?

Answer 20

Often none. Acute or chronic diarrhea

Question 21

How would you diagnose Giardia intestinalis?

Answer 21

fecal smear will show cysts and/or trophozoites; fecal flotation with zinc sulphate; ELISA

Question 22

What are some treatment & prevention options with Giardia intestinalis?

Answer 22

parasiticides (benzimidazoles) and good hygeine. There are, however, no approved treatments in the USA.

Question 23

Describe the appearance of the Trypanosoma cruzi trypomastigote

Answer 23

Trypomastigote in blood smear is elongated, spindle or leaf shaped, 20 um long, with nucleus near middle of its length, posterior end pointed

Question 24

How do trypanosomes enter the body?

Answer 24

oral, nasal, conjunctival mucosae or by infectious bug feces rubbed into skin abrasions