[Elizabeth_Zeibig]_Clinical_Parasitology__A_Practi(z-lib.org)

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CHAPTER 7 Miscellaneous Protozoa
CASE STUDY 7-2
UNDER THE MICROSCOPE—cont’d
permanent stain did not confirm the laboratory technician’s
suspicions. Not satisfied that the sample was negative, the
laboratory technician performed an alternative permanent
stain. The organisms seen on this stain are illustrated in the
diagram. These organisms were noted as 5 µm in size with
one to six dark granules within their cytoplasm.
Questions and Issues for Consideration*
1. What organism did the laboratory technician suspect,
and why? What morphologic form is seen in this
diagram? (Objective 7-10A)
2. What was the alternative permanent stain, and how
would these parasites appear following this stain procedure?
(Objective 7-10E, 7-12)
3. What fungal elements might appear similar to this
organism? How would they stain with the alternative
stain? (Objective 7-10H, 7-12)
Average size: 4-6 m
*Please see Chapter 2 for assistance in answering questions relating to parasite appearance after staining.
COMPARISON DRAWINGS
Intestinal Miscellaneous Protozoa
FIGURE 7-5A. Balantidium coli trophozoite
FIGURE 7-6A. Balantidium coli cyst
Size range: 28-152 m by 22-123 m
Average size: 35-50 m by 40 m
FIGURE 7-7. Isospora belli oocyst
Size range: 43-66 m
Average size: 52-55 m
FIGURE 7-8. Sarcocystis oocyst
Size range: 25-35 m by 10-15 m
Average size: 30 m by 12 m
Average sporocyst length: 10-18 m