Chapter 50: Opportunistic Mycoses

Chapter 50: Opportunistic Mycoses

SELF-ASSESSMENT QUESTIONS

1. Regarding C. albicans, which one of the following is most accurate?

(A) The diagnosis of disseminated candidiasis is typically made by

detecting IgM antibodies.

(B) It exists as a yeast on mucosal surfaces but forms pseudohyphae

when it invades tissue.

(C) Antibody-mediated immunity is a more important host defense

than cell-mediated immunity.

(D) A positive skin test can be used to confirm the diagnosis of skin

infection caused by C. albicans.

(E) In the clinical laboratory, it is diagnosed by isolating a mold

with nonseptate hyphae when cultures are grown at room

-temperature.

1. Regarding Cryptococcus neoformans, which one of the following is

most accurate?

(A) It is a dimorphic fungus, growing as a mold in the soil and a

yeast in the body.

(B) It is acquired primarily by ingestion of food contaminated with

pigeon guano.

(C) Dark field microscopy is typically used to visualize the organism

in spinal fluid.

(D) Pathogenesis involves an exotoxin that acts as a superantigen

recruiting lymphocytes into the spinal fluid.

(E) Laboratory diagnosis of cryptococcal meningitis can be

achieved by detecting the capsular polysaccharide of the organism

in the spinal fluid.

1. Regarding Aspergillus fumigatus and aspergillosis, which one of

the following is most accurate?

(A) The natural habitat of A. fumigatus is the hair follicles of the

human skin.

(B) In the clinical laboratory, cultures of A. fumigatus incubated at

37°C form yeast colonies.

(C) The India ink stain is typically used to visualize A. fumigatus in

the clinical laboratory.

(D) A. fumigatus causes “fungus balls” in patients with lung cavities

caused by tuberculosis.

(E) The main predisposing factor to allergic bronchopulmonary

aspergillosis is neutropenia.

1. Regarding Mucor species, which one of the following is most

accurate?

(A) Infection is acquired by the ingestion of food contaminated by

spores of the organism.

(B) Diabetic ketoacidosis is a major predisposing factor for invasive

mucormycosis.

(C) Mucor species have septate hyphae in contrast to Aspergillus

species, which have nonseptate hyphae.

(D) In biopsy specimens obtained from patients with invasive disease,

Mucor species appear as pseudohyphae.

(E) Skin tests using mucoroidin as the immunogen are used to determine

whether the patient has been infected with Mucor species.

1. Your patient is a 20-year-old woman who is human immunodeficiency

virus (HIV) antibody positive with a CD4 count of 50.

She has recovered from cryptococcal meningitis. Which one of

the following is the best choice of drug to use as long-term prophylaxis

to prevent another episode of cryptococcal meningitis?

(A) Amphotericin B

(B) Caspofungin

(C) Fluconazole

(D) Flucytosine

(E) Terbinafine

1. Your patient is a 1-month-old infant with whitish lesions in the

mouth that are diagnosed as oropharyngeal candidiasis (thrush).

Which one of the following is the best choice of drug to treat this

infection?

(A) Amphotericin B

(B) Caspofungin

(C) Fluconazole

(D) Flucytosine

(E) Terbinafine

1. Your patient is a 50-year-old woman with leukemia who is neutropenic

from her cancer chemotherapy. She now has disseminated

aspergillosis that does not respond to amphotericin B. Which one

of the following is the best choice of drug to treat this infection?

(A) Amphotericin B

(B) Caspofungin

(C) Fluconazole

(D) Flucytosine

(E) Terbinafine

ANSWERS

1. (B)
2. (E)
3. (D)
4. (B)
5. (C)
6. (C)
7. (B)