[Elizabeth_Zeibig]_Clinical_Parasitology__A_Practi(z-lib.org)

CHAPTER 4 The Flagellates
101
Column A
___ D. Retortamonas
intestinalis
___ E. Chilomastix
mesnili
___ F. Trichomonas
vaginalis
Column B
4. Specimen of
choice is a
mouth scraping
5. Specimen of
choice can be a
urethral swab
6. Fibrils form a
characteristic
bird’s beak
4-2. List the intestinal and then the atrial flagellates.
(Objective 4-4)
4-3. Which of the flagellates are commonly
found in the United States? (Objective 4-2)
4-4. Which of the flagellates is(are) considered
to be sexually transmitted infections?
(Objective 4-6)
4-5. Describe the life cycles of Giardia intestinalis,
Dientamoeba fragilis, and Trichomonas
vaginalis. (Objective 4-5C)
4-6. Other than size, list three major morphologic
characteristics that are visible with
routine staining preparations of each of
the flagellates. (Objective 4-9A)
4-7. List the flagellates that have both trophozoite
and cyst stages, and list those that
have one or the other. (Objectives 4-5A,
4-5B, and 4-11)
4-8. Which of the flagellates can cause gastrointestinal
distress? (Objectives 4-6, 4-11A)
4-9. Define the following terms: (Objective 4-1)
A. Axoneme
B. Axostyle
C. Costa
D. Cytosome
E. Median bodies
F. Undulating membrane
4-10. Why can Giardia intestinalis and Dientamoeba
fragilis be difficult to diagnose?
Which specimen collection regimen should
be used? (Objectives 4-8, 4-11A, and 4-12)
4-11. Which of the flagellates can be contracted
by ingesting the cyst form of the organism?
(Objective 4-5C, 4-11A)
4-12. Which of the flagellates are considered to
be nonpathogens? (Objective 4-11A)
4-13. An infection caused by which of the flagellates
can be a result of poor oral hygiene?
(Objective 4-5C)
CASE STUDY 4-2
UNDER THE MICROSCOPE
Marcy took her two young children, Justin, age 4 years, and
Shannon, age 6 years, to their pediatrician for evaluation.
Both children had been ill for several days. Their symptoms
included diarrhea with mucoid stools, weakness, flatulence,
nausea, and abdominal cramping. Stool samples from both
children were sent to the laboratory for parasite examination
(O&P), culture, and sensitivity. The culture showed no
intestinal pathogens.
Standard O&P processing techniques were carried out,
and the organisms shown in the diagram were observed
on the permanent stain. The roundish organisms each measured
approximately 12 µm in diameter and had two
somewhat discrete nuclei.
2. Which permanent stain was likely used in this case?
(Objective 4-10F)
3. Name the structures that are shown in the diagram.
(Objective 4-10A)
4. What structures allow this parasite to move? (Objective
4-10A)
5. What other morphologic forms, if any, may be seen in
clinical samples of patients infected with this parasite?
(Objective 4-10I)
6. By what means is it suspected that this parasite may be
transmitted to unsuspecting humans? (Objective 4-10D)
Questions for Consideration
1. Based on the morphology of the organism depicted
here, which parasite do you suspect is present? State
the full name of the parasite (i.e., genus and species).
(Objective 4-10B)