Weekly Year 3: Medical Mycology Exam - August 21, 2026 (S...

Question 1

An organism without a known sexual stage of reproduction would be classified in which of the following fungal groups?

Accepted Answer

Deuteromycota (Fungi Imperfecti) — Fungi with no known teleomorph (sexual stage) are classified as Deuteromycota (Fungi Imperfecti or Mitosporic fungi).

Question 2

An antifungal drug such as Miconazole inhibits proper formation of which cellular component?

Accepted Answer

Ergosterol (plasma membrane component) — Azoles like miconazole block ergosterol synthesis, disrupting plasma membrane formation in fungi.

Question 3

Which of the following fungi would you most likely find growing in pigeon droppings?

Accepted Answer

Cryptococcus neoformans — Cryptococcus neoformans is commonly found in soil contaminated with pigeon droppings.

Question 4

Which fungal condition causes more than 200 million cases per year worldwide, with symptoms including an itching sensation and burning internal pain?

Accepted Answer

Vulvovaginal candidiasis — Vulvovaginal candidiasis is extremely common worldwide, causing itching and internal burning.

Question 5

The formation of arthrospores and spherules in infected tissue is characteristic of which fungal disease?

Accepted Answer

Coccidioidomycosis — Coccidioides forms arthroconidia in soil/mold form and spherules in tissue.

Question 6

Aflatoxin is produced by which organism, and what type of substance is it?

Accepted Answer

Aspergillus flavus; potent hepatocarcinogen — Aspergillus flavus produces aflatoxin, a potent hepatocarcinogen.

Question 7

A girl who pricked her finger while pruning rose bushes develops a local pustule that progresses to an ulcer. Several nodules then develop along the local lymphatic drainage. What is the most likely causative agent?

Accepted Answer

Sporothrix schenckii — This describes the classic 'rose gardener's disease' – lymphocutaneous sporotrichosis caused by Sporothrix schenckii.

Question 8

Fungal cells that reproduce by budding are seen in the infected tissues of patients with which of the following conditions?

Accepted Answer

Candida infection, Cryptococcosis, and Sporotrichosis — Candida, Cryptococcus, and Sporothrix all appear as budding yeasts in tissue.

Question 9

Which statement regarding paracoccidiomycosis is NOT correct?

Accepted Answer

It is caused by Paracoccidioides brasiliensis. — Paracoccidioides brasiliensis is susceptible to amphotericin B, not resistant.

Question 10

A kidney transplant patient develops a nosocomial systemic candidiasis. The isolated Candida glabrata is resistant to fluconazole. Which of the following would be a reasonable oral alternative for treatment?

Accepted Answer

Posaconazole — Posaconazole often retains activity against fluconazole-resistant Candida species.

Question 11

All of the following are characteristics of systemic/deep mycoses EXCEPT:

Accepted Answer

They are always restricted to the skin and hair. — Not all systemic fungal infections start in the lungs (e.g., candidiasis can be catheter/GI-related), and they are not always restricted to the skin and hair.

Question 12

Thousands of people in the western USA experienced a flu-like illness in 1992 following inhalation of soil fungal spores. This illness is known as 'valley fever.' What is the pathogen?

Accepted Answer

Coccidioides immitis — Coccidioidomycosis is commonly known as Valley Fever and is endemic to the southwestern US.

Question 13

Amphotericin B would be used to treat all of the following EXCEPT:

Accepted Answer

Superficial dermatophytosis — Amphotericin B is a potent antifungal used for systemic infections; superficial dermatophytoses are typically treated with topical or oral antifungals.

Question 14

All of the following are superficial mycoses EXCEPT:

Accepted Answer

Candidiasis of the esophagus — Candidiasis of the esophagus is a mucosal or deep-seated infection, not a superficial mycosis of the skin or hair.

Question 15

Which of the following statements regarding Tinea nigra is NOT correct?

Accepted Answer

It is treated with oral antifungal medications. — Tinea nigra is typically treated with topical antifungal agents; oral medications are generally reserved for more extensive or recalcitrant cases.

Question 16

Which of the following is the common cause of Athlete's foot?

Accepted Answer

Dermatophytes (e.g., Trichophyton rubrum) — Dermatophytes, particularly species of Trichophyton, are the most common cause of Tinea pedis (Athlete's foot).

Question 17

All of the following are characteristics of cutaneous mycoses EXCEPT:

Accepted Answer

They often present with pustules and abscesses. — While pustules and abscesses can occur in some cutaneous infections, this is not a universal characteristic, and some cutaneous mycoses present with scaling or discoloration.

Question 18

All of the following dermatophytes are responsible for nail infections EXCEPT:

Accepted Answer

Microsporum canis — Microsporum species typically infect hair and skin but not nails, whereas Trichophyton and Epidermophyton are common causes of onychomycosis.

Question 19

Which of the following is an opportunistic pathogenic fungus in humans?

Accepted Answer

Candida albicans — While all can cause disease, Candida albicans is a common commensal that becomes opportunistic in immunocompromised individuals or when normal flora is disrupted.

Question 20

Aspergillosis is recognized in tissue by the presence of:

Accepted Answer

Hyphae with septations and dichotomous branching — Aspergillus species are characterized by septate hyphae with dichotomous (45-degree) branching, often forming characteristic conidiophores.

Question 21

Fungi often colonize lesions caused by other agents. Which of the following is LEAST likely to be present as a colonizer?

Accepted Answer

Staphylococcus aureus — While Staphylococcus aureus can colonize wounds, it's a bacterium and less commonly considered a fungal colonizer in the context of fungal opportunistic infections. Candida, Aspergillus, and dermatophytes are common fungal colonizers.

Question 22

Which statement regarding dermatophytosis is correct?

Accepted Answer

It is caused by fungi that utilize keratin for growth. — Dermatophytosis, also known as ringworm, is caused by fungi called dermatophytes that have the ability to digest keratin, found in skin, hair, and nails.

Question 23

Which statement regarding laboratory identification of fungi is correct?

Accepted Answer

Molecular methods are increasingly used for accurate and rapid identification. — While KOH mounts can reveal fungal elements, definitive species identification often requires culture. Fungal cultures can take days to weeks. India ink is for encapsulated yeasts like Cryptococcus. Molecular methods offer speed and accuracy.

Question 24

All of the following are examples of superficial mycoses EXCEPT:

Accepted Answer

Systemic candidiasis — Systemic candidiasis is a deep-seated or disseminated fungal infection, not a superficial mycosis.

Question 25

Amphotericin B would be used to treat all of the following EXCEPT:

Accepted Answer

Cutaneous candidiasis — Cutaneous candidiasis is typically treated with topical or oral antifungals. Amphotericin B is reserved for more severe or systemic infections.

Question 26

A component of the cell membrane of most fungi is:

Accepted Answer

Ergosterol — Ergosterol is the primary sterol found in fungal cell membranes, analogous to cholesterol in animal cell membranes, and is a target for many antifungal drugs.

Question 27

Which statement regarding dermatophytosis is correct?

Accepted Answer

It is caused by fungi that metabolize keratin. — Dermatophytes are fungi that can break down keratin, allowing them to infect skin, hair, and nails. Many cases can be treated with topical agents.

Question 28

Which statement regarding laboratory identification of fungi is correct?

Accepted Answer

Direct microscopic examination is sufficient for all fungal identification. — Special stains like Gomori methenamine silver (GMS) or periodic acid-Schiff (PAS) are valuable for visualizing fungal structures in tissue samples.

Question 29

Which of the following is an opportunistic pathogenic fungus in humans?

Accepted Answer

Pneumocystis jirovecii — Pneumocystis jirovecii is an obligate opportunistic pathogen that causes Pneumocystis pneumonia (PCP), primarily in immunocompromised individuals.

Question 30

Aspergillosis is recognized in tissue by the presence of:

Accepted Answer

Septate hyphae with acute angle branching — Aspergillus species are characterized by septate hyphae that branch dichotomously at acute angles (around 45 degrees).

Question 31

Fungi often colonize lesions caused by other agents. Which of the following is LEAST likely to be present as a colonizer?

Accepted Answer

Staphylococcus aureus — While Staphylococcus aureus can colonize wounds, it is a bacterium. Candida, Aspergillus, and dermatophytes are common fungal colonizers of various lesions.

Question 32

Each of the following statements concerning Cryptococcus neoformans is correct EXCEPT:

Accepted Answer

It is a common cause of pneumonia in immunocompetent individuals. — While Cryptococcus neoformans can cause pneumonia, it is a significant opportunistic pathogen that primarily causes severe disease (like meningitis) in immunocompromised individuals.

Question 33

Each of the following statements concerning Candida albicans is correct EXCEPT:

Accepted Answer

It is a dimorphic fungus. — Candida albicans is dimorphic in that it can exist as a yeast or filament (pseudohyphae/hyphae), but it does not typically have a distinct mold phase like some dimorphic pathogens.

Question 34

Natural habitat for Paracoccidioides brasiliensis is:

Accepted Answer

Soil and decaying vegetation in endemic areas — Paracoccidioides brasiliensis is found in soil and on vegetation, particularly in rural areas of Latin America.

Question 35

Coccidioidomycosis is also called:

Accepted Answer

Valley Fever — Coccidioidomycosis is commonly known as Valley Fever. San Joaquin Fever is also used, especially in California. Desert Rheumatism is an older term for associated arthralgias.

Question 36

One of the most common mycotoxins that infects nuts and grains and causes severe reactions is:

Accepted Answer

Aflatoxin — Aflatoxins, produced by Aspergillus species, are potent carcinogens and are commonly found in contaminated nuts and grains.

Weekly Year 3: Medical Mycology Exam - August 21, 2026 (S...

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