Fungi

Question 1

Dematiaceous

Answer 1

Dark colored

Question 2

Agent of ringworms

Answer 2

Trichophyton Microsporum

Question 3

Dimorphic fungi

30 degrees- yeast

25 degrees- mould

Answer 3

Blastomyces

Histoplasma

Coccidioides

Sporothrix

Paracoccidioides

Question 4

Hyaline

Answer 4

Clear

Question 5

Septate hyphae

Answer 5

Cross walls with fairly regular width

Question 6

Nonseptate hyphae

Answer 6

No cross walls, broad hyphae with irregular width, broad branching angle

Question 7

Conidia

Answer 7

Asexual spores formed off of hyphae, airborne

Question 8

Blastoconidia

Answer 8

Buds on yeast ( asexual budding daughter yeast cells)

Question 9

Arthroconidia

Answer 9

Asexual spores formed by a joint

Question 10

Spherules and endospores

Answer 10

Spores inside spherules in tissues, common to Coccidioides

Question 11

Culture media for recovering fungi

Answer 11

• Sabouraud agar
• blood agar
• both of these with antibiotics

Question 12

• Caused by malassezia furfur
• Superficial infection of keratinized cells
• Likes warm, moist climates
• Hypopigmented spots on chest/back
• KOH mount shows spaghetti and meatball appearance
• Yeast clusters with short curved septate hyphae
• Coppery- orange under woods lamp
• Treat with topical selenium sulfide
• Causes fungemia in premature infants on I’ve lipid supplements
• Inhibits pigment production by interfering with tyrosinases

Answer 12

Tinea versicolor or pityriasis

Question 13

Agent of Black piedra

Answer 13

Piedra horti Rare in US, more in tropical areas

Question 14

• Infection of hair shafts
• Hard black nodules along shaft that weaken hair
• Broken hair shaft may resemble Tinea capitis
• Tx: haircut and topical salicylic acid, oral terbinafine or clotrimazole
• Caused by piedra hortai

Answer 14

Black piedra

Question 15

Agent of white piedra

Answer 15

• Trichsporon beigelii
• Seen in semitropics, southern US

Question 16

• Soft, tan nodules surrounding hair shaft
• Dissemination in immunocompromised (neutropenic)
• Tx: remove infected hair, salicylic acid, selsun, or oral antifungals (clotrimazole, ketoconazole)
• May resemble head lice
• Caused by trichosporon beigelii

Answer 16

White piedra

Question 17

Agent of Tinea nigra

Answer 17

Hortaea werneckii

From soil, wood

Rare in US mostly coastal (pt vacationing in caribbean)

Question 18

• Brown-black patches on palms, soles
• Thickened and dark pigment
• Detect with KOH prep of skin scrapings
• Demitiacious hyphae
• Treat with salicylic acid, 10% benzoic acid, or oral antifungals
• Superficial infection caused by hortaea werneckii

Answer 18

Tinea nigra

Question 19

Superficial fungal infections and their causative agents

Answer 19

• Tinea versicolor/pityriasis–> malassezia furfur
• Black piedra–> piedra hortai
• White piedra–> trichosporon beigelii
• Tinea nigra–> hortaea werneckii

Question 20

Dermatophytes

Answer 20

• Trichophyton species
• Microsporum species
• Epidermophyton floccosum

Question 21

Dermatophyte that affects hair, skin, and nails

Answer 21

Trichophyton species

Question 22

Dermatophyte that affects hair and skin

Answer 22

Microsporum species

Question 23

Dermatophyte that affects skin and nails

Answer 23

Epidermophyton floccosum