Deck 27: Medically Significant Fungi

Question 1

A patient with very pale patches on his arms and legs is examined at his physician's office. His physician orders a fungal culture. The fungus shows a "spaghetti-and-meatball" appearance on the direct smear. What organism is it?

A) Microsporum canis
B) Malassezia furfur
C) Trichophyton rubrum
D) Epidermophyton floccosum

Answer 1

B

Question 2

A recreational cave explorer develops a productive cough and fever. A sputum culture is sent to the laboratory for bacterial, fungal, and mycobacterial cultures. A white mold colony develops on Sabouraud dextrose agar after 5 days at 22° C. Identify the organism from the following:

A) Histoplasma capsulatum
B) Toxoplasma gondii
C) Microsporum tonsurans
D) Paracoccidioides brasiliensis

Answer 2

A

Question 3

A young boy develops itchy, dry scaly lesions on his leg with a raised, red, outer edge. A culture of the lesion reveals the following organism in a lactophenol cotton blue stain. This organism is most likely

A) Trichophyton spp.
B) Mucor spp.
C) Microsporum canis.
D) Blastomyces dermatitidis.

Answer 3

C

Question 4

This organism was isolated from a diabetic patient with a sinus infection. The mold was extremely fast growing with a dirty white surface. Microscopic observation revealed wide sparsely septate (aseptate) hyphae without rhizoids. This organism is most likely

A) Mucor spp.
B) Microsporum spp.
C) Sporothrix schenckii.
D) Malassezia furfur.

Question 5

A patient who wears long-term contact lenses comes to her physician after noting a small spot on her cornea. Collection of the lesion for culture produced a fast-growing mold with a slight pink color on the surface. Microscopic review showed the following organism. This organism is most likely

A) Sporothrix schenckii.
B) Fusarium spp.
C) Mucor spp.
D) Geotrichum spp.

Question 6

The following organism was isolated from an immunocompetent patient with chronic sinusitis. This organism is most likely

A) Mucor spp.
B) Rhizopus spp.
C) Alternaria spp.
D) Curvularia spp.

Question 7

A Seattle woman with HIV complains of headaches and also displays some memory loss. Because of her history, the physician collects cerebrospinal fluid (CSF) and sends it to the laboratory for analysis. The following image is seen using India ink stain. What is the most likely identification of this organism?

A) Coccidioides immitis
B) Blastomyces dermatitidis
C) Cryptococcus gattii
D) Candida albicans

Question 8

The following organism is isolated from a case of tinea capitis. The organism grew rapidly producing tan mold colonies. This organism is most likely

A) Trichophyton rubrum.
B) Epidermophyton audouinii.
C) Fonsecaea compacta.
D) Microsporum gypseum.

Question 9

A bone marrow transplant patient develops an abrupt fever with respiratory distress. Despite treatment with antifungal medications, the patient dies on the fifth day. The following organism was isolated from both sputum and blood cultures. Identify the organism seen in the image below.

A) Rhizopus spp.
B) Mucor spp.
C) Histoplasma capsulatum
D) Aspergillus spp.

Question 10

The following organism was isolated from the sputum culture of a cancer chemotherapy patient. This organism is most likely

A) Mucor spp.
B) Penicillium spp.
C) Geotrichum spp.
D) Alternaria spp.

Question 11

A graduate student returning from a month-long fieldwork experience in South America develops a dark nodular lesion on his left hand. Microscopic examination of the nodule reveals dark, coinlike inclusions. The following organism grows in culture. This organism is most likely

A) Cladosporium spp.
B) Candida spp.
C) Coccidioides immitis.
D) Cryptococcus neoformans.

Question 12

This organism was isolated from a sinus aspirate of a patient with chronic sinusitis and respiratory allergies. Identify the organism from the following:

A) Candida albicans
B) Alternaria spp.
C) Mucor spp.
D) Pseudallescheria boydii

Question 13

A student working for the summer at a plant nursery has a nodular lesion on his forearm that develops a draining tract. The following organism is isolated from the culture at 22° C. Identify the organism from the following:

A) Trichosporon boydii
B) Sporothrix schenckii
C) Trichophyton rubrum
D) Microsporum canis

Question 14

A patient returning from a trip to tropical Africa comes to his physician noting scaly patches of skin along the waistband, which are lighter in color than his normal skin. A skin scraping reveals budding yeast and short septate hyphal elements, with some branching present. This organism, shown below, is most likely

A) Malassezia furfur.
B) Trichophyton schoenleinii.
C) Microsporum audouinii.
D) Trichophyton rubrum.

Question 15

What is the causative agent of tinea nigra?

A) Microsporum canis
B) Trichosporon beigelii
C) Piedraia hortae
D) Hortaea werneckii

Question 16

A young man notices a darkened area of skin on the palm of his hand. It seems to be increasing in size over the past 2 weeks. His health care provider collects a skin scraping for microscopic examination, which shows septate hyphal elements and budding cells. This organism is most likely

A) Malassezia furfur.
B) Mucor spp.
C) Hortaea werneckii.
D) Microsporum canis.

Question 17

What is the causative agent of black piedra?

A) Microsporum canis
B) Trichosporon beigelii
C) Piedraia hortae
D) Sporothrix schenckii

Question 18

All of the following are examples of dimorphic fungi, except

A) Candida albicans.
B) Coccidioides immitis.
C) Histoplasma capsulatum.
D) Sporothrix schenckii.

Question 19

After returning from a vacation trip to the Amazon River delta in Brazil, a man notices a white dirtlike substance on his axilla hair that does not wash off in the shower. His health care provider samples the hairs and sends them to the laboratory for culture. Straw-colored yeastlike colonies show the following microscopic morphology. This is most consistent with an identification of

A) Malassezia furfur.
B) Trichosporon spp.
C) Microsporum audouinii.
D) Trichophyton rubrum.

Question 20

A patient with thickened and discolored nails was diagnosed with onychomycosis. A scraping of the nail was sent for culture. Microscopic analysis of the mold colony growth revealed the following morphology. The most likely identity of this organism is

A) Microsporum canis.
B) Sporothrix schenckii.
C) Aspergillus fumigatus.
D) Trichophyton mentagrophytes.

Question 21

What organism is found in the San Joaquin Valley region of California?

A) Sporothrix schenckii
B) Penicillium marneffei
C) Coccidioides immitis
D) Paracoccidioides brasiliensis

Question 22

Chromoblastomycosis is caused by all the following organisms, except

A) Fonsecaea compacta.
B) Penicillium marneffei.
C) Fonsecaea pedrosoi.
D) Phialophora verrucosa.

Question 23

What organism frequently presents in fungus balls?

A) Fonsecaea compacta
B) Penicillium marneffei
C) F. pedrosoi
D) Aspergillus fumigatus

Question 24

All of the following organisms cause cutaneous mycoses, except

A) Sporothrix schenckii.
B) Trichophyton beigelii.
C) Microsporum canis.
D) Epidermophyton floccosum.

Question 25

What organism is one of the primary opportunistic infections in AIDS patients?

A) Pneumocystis jirovecii
B) Hortaea werneckii
C) Coccidioides immitis
D) Paracoccidioides brasiliensis

Question 26

For KOH to work properly, what is done to speed up the dissolution of the keratin and skin layers?

A) Mix gently.
B) Let the slide sit for 30 minutes before reading.
C) Heat gently, then cool.
D) Let sit under an ultraviolet light for 20 minutes.