Deck 63: Anti-fungal Susceptibility Testing, Therapy, and Prevention

Question 1

A patient who is positive for the human immunodeficiency virus (HIV)is diagnosed with a Cryptococcus neoformans infection.The attending resident prescribed Griseofulvin; however, the patient's condition did not seem to improve.Which one of the following statements explains this discrepancy?

A) The dose should be increased to penetrate the blood-brain barrier.
B) Nystatin, which would have been more effective, should have been prescribed.
C) Griseofulvin is not effective against C. neoformans; therefore the therapy should be changed.
D) Potassium iodide is the therapy of choice, not griseofulvin.

Answer 1

C
Fluconazole has excellent activity against most Candida spp.and Cryptococcus neoformans; therapeutic levels are easily reached in the central nervous system.Griseofulvin is an oral agent used to treat dermatophytosis fungal infections; therefore the wrong antifungal was prescribed to this patient.

Question 2

MATCHING
Match the antifungal agent with its mode of action.
a.Amphotericin B
b.Griseofulvin
c.5-Fluorocytosine
d.Echinocandin
e.Azole
Binds microtubular proteins

Answer 2

B

Question 3

The agency that provides documents and sets standards for antifungal susceptibility testing is the:

A) National Accrediting Agency for Clinical Library Sciences (NAACLS).
B) Association of Specialized and Cooperative Library Agencies (ASCLS).
C) College of American Pathologists (CAP).
D) Clinical Laboratory Standards Institute (CLSI).

Answer 3

D
The Clinical Laboratory Standards Institute (CLSI), formerly the National Committee for Clinical Laboratory Standards (NCCLS), provides documents and sets standards for antifungal susceptibility testing.Their website is available at www.nccls.org.

Question 4

MATCHING
Match the antifungal agent with its mode of action.
a.Amphotericin B
b.Griseofulvin
c.5-Fluorocytosine
d.Echinocandin
e.Azole
Alters membrane permeability

Question 5

MATCHING
Match the antifungal agent with its mode of action.
a.Amphotericin B
b.Griseofulvin
c.5-Fluorocytosine
d.Echinocandin
e.Azole
Interferes with ergosterol synthesis

Question 6

MATCHING
Match the antifungal agent with its mode of action.
a.Amphotericin B
b.Griseofulvin
c.5-Fluorocytosine
d.Echinocandin
e.Azole
Is a glucan synthesis inhibitor

Question 7

MATCHING
Match the antifungal agent with its mode of action.
a.Amphotericin B
b.Griseofulvin
c.5-Fluorocytosine
d.Echinocandin
e.Azole
Inhibits protein synthesis

Question 8

The Reference Method for Broth Dilution Antifungal Susceptibility Testing of Filamentous Fungi; Approved Standard (M38-A)describes the guidelines for antifungal susceptibility testing for molds.The suspension must be standardized with a spectrophotometer.Susceptibility testing is determined by which method?

A) Disk diffusion
B) Microdilution
C) Broth dilution
D) Immunodiffusion

Question 9

A patient is diagnosed with an invasive Aspergillosis infection.The antifungal therapy that should be administered is:

A) nystatin.
B) griseofulvin.
C) amphotericin B.
D) fluconazole.