Mycology

Topics in this chapter

• Superficial and Cutaneous Mycoses
• Subcutaneous Mycoses
• Systemic Dimorphic Mycoses
• Opportunistic Invasive Mycoses
• Fungal Laboratory Identification
• Antifungal Drugs and Mechanisms

Practice questions

1. Question 1Q-3B972B

   A 45-year-old uncontrolled diabetic patient presents with a blackish nasal discharge, facial pain, and left-sided ptosis. Biopsy from the nasal mucosa reveals broad, non-septate hyphae branching at right angles (90 degrees). Which of the following is the drug of choice for the management of this condition?

   1. A.Fluconazole
   2. B.Liposomal Amphotericin B
   3. C.Voriconazole
   4. D.Caspofungin
   See the answer and solution
2. Question 2Q-0BCBA7

   A 30-year-old HIV-positive male presents with subacute meningitis. CSF analysis shows high opening pressure, low glucose, and high protein. India ink preparation of the CSF reveals yeast cells with a prominent unstained halo. Which fungal structure constitutes the primary virulence factor responsible for the halo?

   1. A.Chitin cell wall
   2. B.Melanin pigment
   3. C.Glucuronoxylomannan capsule
   4. D.beta-glucan layer
   See the answer and solution
3. Question 3Q-27B98D

   A gardener presents with a nodular, ulcerating skin lesion on his right index finger, along with similar painless subcutaneous nodules tracking up the lymphatic drainage of the arm. The causative agent is cultured at 25 degrees Celsius and 37 degrees Celsius. What is the characteristic microscopic morphology of this dimorphic fungus at 25 degrees Celsius (room temperature)?

   1. A.Broad, aseptate hyphae with sporangiospores
   2. B.Spherules containing endospores
   3. C.Tuberculate macroconidia and smooth microconidia
   4. D.Thin, septate hyphae with delicate conidia arranged in rosettes (daflower-like)
   See the answer and solution
4. Question 4Q-35BAA1

   A patient with prolonged neutropenia develops pulmonary infiltrates. A sputum sample grows a mold that forms 45-degree dichotomously branching septate hyphae. Serum galactomannan assay is positive. Which fungus is the most likely etiology?

   1. A.Aspergillus fumigatus
   2. B.Mucor circinelloides
   3. C.Histoplasma capsulatum
   4. D.Candida albicans
   See the answer and solution
5. Question 5Q-208939

   A 22-year-old immigrant from the Ohio River Valley presents with fever, weight loss, and hepatosplenomegaly. A bone marrow aspirate is performed, and intracellular yeast cells are seen within macrophages, resembling small oval yeasts with a narrow-based bud. The fungus responsible for this infection is:

   1. A.Blastomyces dermatitidis
   2. B.Histoplasma capsulatum
   3. C.Coccidioides immitis
   4. D.Paracoccidioides brasiliensis
   See the answer and solution