Dematiaceous Fungi

Question 1

dark or black

Answer 1

melanized

Question 2

Reverse of colony is dark or black (front may vary)

Answer 2

dematiaceous

Question 3

Infection with black molds

Answer 3

phaeohyphomycosis

Question 4

Chronic subcutaneous skin condition with cauliflower-like growths; always caused by dematiaceous fungi

Answer 4

chromomycosis/chromoblastomycosis

Question 5

Chronic granulomatous infection; usually at site of inoculation; swollen tissue with draining sinus tracts (grainy discharge); invasive into the bone

Answer 5

mycetoma

Question 6

Inflammation of the cornea of the eye caused by many different bacteria, yeast, molds, parasites,

Answer 6

keratitis

Question 7

Mycetoma agent of infection by bacteria (gram positive bacilli); branching, filamentous

Answer 7

actinomycotic

Question 8

Agent of mycetoma by fungi; often dematiaceous fungi (BLACK granules); less often non-dematiaceous (WHITE granules)

Answer 8

eumycotic

Question 9

(“copper pennies”) in tissue diagnostic for chromoblastomycosis

Answer 9

medlar (or sclerotic or muriform) bodies

Question 10

Most common organism that cause tinea nigra

Answer 10

Hortaea werneckii

Question 11

Most common organism that causes black piedra

Answer 11

Piedraia hortae

Question 12

Most common organism that causes chromoblastomycosis

Answer 12

Slow growing dematiaceous fungi:

• Fonsecaea
• Phialophora
• Cladophialophora

Question 13

Most common organism that causes white grain mycetoma

Answer 13

Pseudallescheria boydii, Fusarium and others

Question 14

Most common organism that causes black grain mycetoma

Answer 14

Exophiala and others

Question 15

Most common organism that causes actinomycotic mycetoma

Answer 15

Partially Acid Fast: Nocardia, Rhodococcus and others

Nonacid-fast: Streptomyces, Actinomadura

Question 16

Most common organism that causes cerebral phaeohyphomycosis

Answer 16

Cladophialophora bantiana (leading cause in immunoCOMPETENT individual) 
- Bacterial brain infections are MUCH more common

Question 17

Clinical manifestations involved in tinea nigra

Answer 17

Dark patches on skin, usually palms of hands, soles of feet; can resemble malignant melanoma

Question 18

Clinical manifestations involved in black piedra

Answer 18

Black nodules on hair (any body part)

Question 19

Clinical manifestations involved in chromomycosis

Answer 19

cauliflower-like growths; Sclerotic bodies (“copper pennies”) in tissue

Question 20

Clinical manifestations involved in mycetoma

Answer 20

Swollen tissue with draining sinus tracts (purulent, grainy discharge); sclerotia (also known as granules or grains)

Question 21

Two dematiaceous fungi that are “rapid” growers

Answer 21

Curvularia and Alternaria

Question 22

What is the criteria for slow growers and rapid growers?

Answer 22

Rapid: <7 days
Slow: may take weeks to grow (10-14 days)

Question 23

How is man usually infected?

Answer 23

accidentally infected from traumatic injury, inhalation in immunocompromised people (usually involve lower extremities)

Question 24

What is the gold standard for diagnosing Melanized (Dematiaceous) Fungi?

Answer 24

Culture

Question 25

What are considered cutaneous (superficial) infections?

Answer 25

• Tinea nigra
• Black piedra
• White piedra

Question 26

Subcutaneous infections are usually the result of traumatic inoculation to the deep layers of the skin. What are two examples of this type of infection?

Answer 26

1. Chromoblastomycosis (Chromomycosis)

2. Mycetoma

Question 27

Where are Chromomycosis infections most commonly seen?

Answer 27

tropic or subtropic climates (S. America) but cases seen in U.S.

Question 28

What are diagnostic for chomoblastomycosis?

Answer 28

Sclerotic bodies (copper pennies) in tissue (also known as medlar or muriform bodies

Question 29

What is chomoblastomycosis usually caused by?

Answer 29

slow-growing dematiaceous fungi

Question 30

What is important to culture in a Mycetoma?

Answer 30

Biopsy (culture the grains)

Question 31

Mycotic keratitis is often from what?

Answer 31

traumatic injury, contact lens use, surgery