Mycology MCQs

This organism grew on Sabouraud Dextrose agar without any antimicrobials. The patient presented with onychomycosis onychomycosis of both great toenails. The nails were dark and dystrophic, and thick scale was apparent on both feet. Identify the fungus. 1

Trichophyton rubrum

2

Microsporum distortum

3

Scytalidium dimidiatum

4

Coccidioides immitis

5

Trichophyton violaceum

Q/Q(M)-474523 Report a Problem This organism grew on Sabouraud Dextrose agar without any antimicrobials. The patient presented with onychomycosis onychomycosis of both great toenails. The nails were dark and dystrophic, and thick scale was apparent on both feet. Identify the fungus. 3


This organism is inhibited by cycloheximide in artificial media. Clinically it appears identical to a dermatophyte infection. Q/Q(M)-474523 Report a Problem A biopsy shows broad-based budding thick walled yeast cells, 10-15 um with a double contoured appearance. 1

This yeast has a yeast phase at room temperature

2

Does not grow at 37 � C

3

Usually produces a severe characteristic pulmonary disease

4

May be found in dogs

5

Is transmitted by mosquitoes

Q/Q(M)-474527 Report a Problem A biopsy shows broad-based budding thick walled yeast cells, 10-15 um with a double contoured appearance. 4

May be found in dogs

This biopsy describes Blastomyces dermatitidis which generally can be found in decaying vegetation but can be carried by dogs. Q/Q(M)-474527 Report a Problem Septate hyphae with 90 � branching and thick walled barrel shaped arthroconidia alternating with empty cells best describes the t he microscopic morphology of: 1

Histoplasma capsulatum

2

Sporothrix schenckii

3

Microsporum gypseum

4

Trichophyton tonsurans

5

Coccidioides immitis Q/Q(M)-474516 Report a Problem

1

Septate hyphae with 90 � branching and thick walled barrel shaped arthroconidia alternating with empty cells best describes the t he microscopic morphology of: 5


This is the only organism in this list that fits this description. Q/Q(M)-474516 Report a Problem A patient with scaly feet has a positive KOH. Fungal culture reveals smooth, clubshaped macroconidia attached to hyphae in groups. No microconidida are seen. The organism is: 1

Microsporum canis

2

Epidermophyton floccosum

3

Trichophyton rubrum

4

Microsporum gypseum

5


Q/Q(M)-477322 Report a Problem A patient with scaly feet has a positive KOH. Fungal culture reveals smooth, clubshaped macroconidia attached to hyphae in groups. No microconidida are seen. The organism is: 2


The wet mount Epidermophyton floccosum shows smooth, thin-walled macroconidia without microconidia. The appearance is occasionally referred to as �snow shoes �. Epidermophyton floccosum is incapable of hair invasion, and therefore, does not cause tinea capitis. Q/Q(M)-477322 Report a Problem Which of the following organisms will cause infections of skin, nails and endothrix hair? 1


2

Microsporum audouinii

3

Trichophyton schoenlinii

4

Microsporum canis

5

Trichophyton mentagrophytes

Q/Q(M)-474522 Report a Problem Which of the following organisms will cause infections of skin, nails and endothrix hair? 3

Trichophyton schoenlinii

E. floccosum does not infect hair; M. audouinii and M. canis cause fluorescent ectothrix T. capitis, T. mentagrophytes ectothrix T. capitis. Q/Q(M)-474522 Report a Problem An organism producing an apricot colored colony and reflexive branching with few conidia was cultured from a patient from Africa. Which of the following is/are true? 1. This mostly likely is T. verrucosum 2. This most likely is T. soudanense 3. This

2

most likely is T. violaceum 4. This organism causes endothrix tinea capitis 5. This organism is zoophilic 1

1,5

2

2,4

3

2,4,5

4

3, 4

5

3, 4, 5

Q/Q(M)-474491 Report a Problem An organism producing an apricot colored colony and reflexive branching with few conidia was cultured from a patient from Africa. Which of the following is/are true? 1. This mostly likely is T. verrucosum 2. This most likely is T. soudanense 3. This most likely is T. violaceum 4. This organism causes endothrix tinea capitis 5. This organism is zoophilic 2

2,4

T. soudanense produces an apricot colored colony with reflexive branching. It is an anthropophilic organism causing an endothrix tinea capitis. T. verrucosum produces a white colony and requires thiamine and inositol for sporulation, T. violaceum produces a purple colony and has a partial requirement for thiamine Q/Q(M)-474491 Report a Problem The most common cause of tinea capitis in the United States today is: 1

Trichophyton schoenleinii

2

T. tonsurans

3

T. mentagrophytes

4


5

M. canis

Q/Q(M)-474498 Report a Problem The most common cause of tinea capitis in the United States today is: 2

T. tonsurans

M. audouinii was previously the primary cause of T. capitis in the US. Q/Q(M)-474498 Report a Problem The most sensitive microscopic test for fungal infection is: 1

Potassium Hydroxide

2

Potassium Hydroxide with DMSO

3

Chlorazol Black E

4

Calcofluor white

5

Swartz Lamkins stain

Q/Q(M)-478218 Report a Problem The most sensitive microscopic test for fungal infection is:

3

4

Calcofluor white

Calcofluor white is the most sensitive microscopic test for fungal infection. It is a glucan specific immunofluorescent stain. The remaining options are useful in direct microscopic examination, but not the most sensitive. Q/Q(M)-478218 Report a Problem Which two characteristics combined form a significant risk for acquiring sporotrichosis? 1. Animal handler 2. Male gender 3. Alcoholism 4. Filipino or African decent 5. Genetic predisposition 1

1, 2

2

1, 3

3

3, 4

4

4, 5

5

3, 4

Q/Q(M)-474509 Report a Problem Which two characteristics combined form a significant risk for acquiring sporotrichosis? 1. Animal handler 2. Male gender 3. Alcoholism 4. Filipino or African decent 5. Genetic predisposition 2

1, 3

A variety of domestic animals can carry carr y Sporotrichosis. Alcoholism increases the risk for this cutaneous infection. Q/Q(M)-474509 Report a Problem Which of the following statements regarding dermatophyte infection FALSE? 1

Trichophyton schoenleinii is a common cause of favus

2

Microsporum canis is associated with ectothrix tinea capitis

3

Trichophyton violaceum is normally associated with endothrix tinea capitis

4

Microsporum audouinii displays yellow fluorescence with Wood�s lamp examination

5

Trichophyton rubrum is always an ectothrix infection

Q/Q(M)-477569 Report a Problem Which of the following statements regarding dermatophyte infection FALSE? 5

Trichophyton rubrum is always an ectothrix infection

Organisms that cause an ectothrix pattern of tinea ti nea capitis include M. canis, M. audouinii, M. ferruginosum, M. distortium, M. gypseum and occas ionally T. rubrum. T. tonsurans, T. violaceum, T. soudanense, T. gourvilli, T. yaoundei, and occasionally T. rubrum cause an endothrix pattern. T. schoenleinii causes favus in which hyphae and air spaces are seen in the hair shaft. A bluish-white fluorescence pattern is seen with Wood �s lamp. Clinically, patients have thick, yellow, cup-shaped crusts (scutula); scarring and secondary infection may result. M. canis, M. audouinii, M. ferruginosum, M. distortium display a yellow fluorescence on Wood �s lamp examination. Q/Q(M)-477569 Report a Problem 4

The major endemic area for Histoplasmosis 1

Africa

2

Central America

3

Southwest United States

4

South America

5

Eastern United States

Q/Q(M)-474497 Report a Problem The major endemic area for Histoplasmosis 5

Eastern United States

The endemic area for Histoplasmosis includes: the t he Ohio, Mississippi and Missouri River Valleys Syracuse NY area and the Caribbean. This organism prefers soil with a high nitrogen content such as that enriched with bird and bat guano. Q/Q(M)-474497 Report a Problem Which of the following is TRUE regarding coccidiomycosis? 1

First line treatment in pregnancy is itraconazole

2

Droplet transmission is the most common method of acquisition of disease

3

Southeast Asians are at a higher risk of disseminated disease

4

Erythema nodosum is associated with a poor prognosis

5

Approximately 75% of those contracting the disease will be symptomatic

Q/Q(M)-482493 Report a Problem Which of the following is TRUE regarding coccidiomycosis? 3

Southeast Asians are at a higher risk of disseminated disease

Southeast Asians and African Americans are at a higher risk for disseminated cocci, as are pregnant women and a nd the immunocompromised. Approximately 60% of those contracting coccidiomycosis are asymptomatic, and the disease is infectious not contagious. The most common method of disease acquisition is inhalation from the soil during natural events (dust storms etc). Erythema nodosum is associated with a good prognosis prognosis and the first-line first -line treatment during pregnancy is amphotericin B. (JAAD 2006 CME) Q/Q(M)-482493 Report a Problem Which of the following organisms is most likely to cause a sporotrichoid nodule on the arm: 1

Nocardia brasiliensis

2

Phialophora verrucosa

3

Rhinospiridium seeberii

4

Fusarium

5

Fonsecaea pedrosoi Q/Q(M)-474510 Report a Problem

5

Which of the following organisms is most likely to cause a sporotrichoid nodule on the arm: 1


Nocardia brasiliensis is a common cause of actinomycotic mycetoma and the ulcerative, draining lesions can be misdiagnosed as sporotrichosis. Q/Q(M)-474510 Report a Problem Culturing T. rubrum from a white opacity on the fingernail plate should prompt testing for what? 1

Diabetes mellitus

2

Hypothyroidism

3

Hyperthyroidism

4

HIV

5

Cirrhosis

Q/Q(M)-476555 Report a Problem Culturing T. rubrum from a white opacity on the fingernail plate should prompt testing for what? 4

HIV

White superficial onychomycosis of the fingernails is a marker for immunosuppresion and should prompt testing for HIV. Generally, T. mentag is the most common cause of white superfical onychomycosis. However, in immunosuppressed patients, T. rubrum is the more common dermatophyte. Q/Q(M)-476555 Report a Problem Which of the following statements regarding mycelium is NOT true? 1

A mass of hyphae is mycelium

2

Mycelium has reproductive capability

3

Hyphae forming corkscrew-like turns are spiral hyphae

4

Pectinate bodies are hyphae resembling a comb

5

Racket forms are club-shaped cells

Q/Q(M)-478215 Report a Problem Which of the following statements regarding mycelium is NOT true? 2

Mycelium has reproductive capability

Mycelium does not have reproductive capabilities. The remaining statements a re correct. Q/Q(M)-478215 Report a Problem A pet store owner comes into your office with pruritic scal y plaques on his arms. A fungal culture demonstrates a yellow colony with spindle-shaped macroconidia which grows on polished rice grains. The organism is: 1

Microsporum canis

2

Epidermophyton floccosum 6

3

Trichophyton rubrum

4

Microsporum gypseum

5

Trichophyton tonsurans Q/Q(M)-477336 Report a Problem

A pet store owner comes into your office with pruritic scal y plaques on his arms. A fungal culture demonstrates a yellow colony with spindle-shaped macroconidia which grows on polished rice grains. The organism is: 1

Microsporum canis

Microsporum canis os a zoophilic dermatophyte, which causes ectothrix invasion when infecting the hair. Colonies of M. canis are flat , spreading, white to creamcolored with a dense cottony surface, The reverse of t he plate is a canary yellow. Wet mount of the fungus shows spindle-shaped macroconidia with 5-15 cells and often have a terminal knob. Q/Q(M)-477336 Report a Problem A neutropenic patient has erythematous nodules for several days. A biopsy shows branching septate hyaline hyphae. Which of of the following conditions should be included in the differential? 1. Coccidioidomycosis 2. Fusariosis 3. Aspergillosis 4. Zygomycosis 5. Phaeohyphomycosis 1

1

2

1, 2

3

2, 3

4

3, 4

5

2, 3, 5 Q/Q(M)-474508 Report a Problem

A neutropenic patient has erythematous nodules for several days. A biopsy shows branching septate hyaline hyphae. Which of of the following conditions should be included in the differential? 1. Coccidioidomycosis 2. Fusariosis 3. Aspergillosis 4. Zygomycosis 5. Phaeohyphomycosis 3

2, 3

Aspergillus and Fusarium produce similar appearing morphology in biopsy. Coccidioidomycosis produces spherules, very few if any septations are seen in Zygomycosis, dark hyphae, yeast cells are seen in Phaeohyphomycosis. Q/Q(M)-474508 Report a Problem A 34-year-old male patient presents with a verrucous lesion of the nasal mucosa; the biopsy showed spherules ranging in size from 200 to 325 um. The mature endospores have a rough appearance. The diagnosis is: 1

Coccidioidomycosis

2

Protothecosis 7

3

Rhinosporidiosis

4

Pseudallescheriosis

5

Cryptococcosis Q/Q(M)-474486 Report a Problem

A 34-year-old male patient presents with a verrucous lesion of the nasal mucosa; the biopsy showed spherules ranging in size from 200 to 325 um. The mature endospores have a rough appearance. The diagnosis is: 3

Rhinosporidiosis

The large size of the spherule and the rough endospores describe this organism along with the clinical symptoms. The other organisms that produce spherules are Prototheca (8-20 um) and Coccidioides immitis (10-80 um) Q/Q(M)-474486 Report a Problem A patient returns from a vacation in Brazil with keloidal-like nodules on the face and arms. The patient denies any sick contacts or exposures and reports only lying on the beach and swimming with dolphins. dolphins. She likely has: 1

Actinomycosis

2

Lobomycosis

3

Chromoblastomycosis

4

Mucormycosis

5

Sporotrichosis Q/Q(M)-477329 Report a Problem

A patient returns from a vacation in Brazil with keloidal-like nodules on the face and arms. The patient denies any sick contacts or exposures and reports only lying on the beach and swimming with dolphins. dolphins. She likely has: 2

Lobomycosis

Lobomycosis, also called Keloidal blastomycosis, is caused by Loboa loboi. Lesions characteristically appear keloidal with or without fistulas. A common location for the infection is on the ears and has been associated asso ciated with dolphins. Histologically, double contoured refractile spherules with budding may be seen. Q/Q(M)-477329 Report a Problem Which of the following statements regarding superficial mycotic infections is TRUE? 1

Malassezia species do not fluoresce under a Wood �s lamp

2

Phaeoannellomyces wernecki causes tinea nigra

3

Trichophyton beigelii causes white piedra

4

Trichosporon hortae causes black piedra

5

Micrococcus sedentarius causes tinea nigra

8

Q/Q(M)-477565 Report a Problem Which of the following statements regarding superficial mycotic infections is TRUE? 2

Phaeoannellomyces wernecki causes tinea nigra

Malassezia species fluoresce pale yellow with Wood�s lamp examination. Trichosporon beigelii (not trichophyton) causes white piedra, an infection that causes tan to white, soft non-adherent concretions on head and pubic hairs. Piedraia hortae causes black piedra, which forms dark concretions that are adherent to scalp, beard, and pubic hairs. Micrococcus sedentarius is a bacterium that is responsible for pitted keratolysis, which is characterized by crateriform pitting that primarily affects the pressure-bearing aspects of the plantar surface of the feet and, occasionally, the palms of the hands. Tinea nigra (superficial phaeohyphomycosis) presents with asymptomatic brown to black, macular, non-scaly macules and patches on the palms or soles. Phaeoannellomyces werneckii is causative. Q/Q(M)-477565 Report a Problem The most reliable method for distinguishing between Trichophyton rubrum and T. mentagrophytes is: 1

Morphology of microconidia

2

Morphology of macroconidia

3

Pigmentation studies

4

Hair perforation test

5

Colony morphology Q/Q(M)-474511 Report a Problem

The most reliable method for distinguishing between Trichophyton rubrum and T. mentagrophytes is: 4

Hair perforation test

The diagnostic morphology of the Trichophytons overlap and may be difficult to differentiate. T. mentagrophytes produces a positive hair perforation test (wedges in the test hair). Q/Q(M)-474511 Report a Problem A young girl presented with a scaly annular facial rash and alopecia of her lower eyelashes. Which of the following statements is/are true? 1. A KOH prep and fungal culture might confirm the diagnosis. 2. The etiologic agent might be Microsporum canis. 3. The family puppy might be infected. 4. Griseofulvin would be the drug of choice. 5. A topical azole cream would be the drug of choice. 1

1,2,4

2

1,2,3,4

3

1,3,4

4

1,2,5

9

5

1,2,3,5 Q/Q(M)-474504 Report a Problem

A young girl presented with a scaly annular facial rash and alopecia of her lower eyelashes. Which of the following statements is/are true? 1. A KOH prep and fungal culture might confirm the diagnosis. 2. The etiologic agent might be Microsporum canis. 3. The family puppy might be infected. 4. Griseofulvin would be the drug of choice. 5. A topical azole cream would be the drug of choice. 2

1,2,3,4

KOH and culture are the best and most reliable lab tests to diagnose a fungal infection. M. canis is frequently found in kittens and puppies and is a common cause of tinea faciei in children. An oral antifungal should be prescrib ed when a fungal infection involves hair. Q/Q(M)-474504 Report a Problem This organism does not produce microconidia. The macroconidia are club shaped, and smooth walled, they grow singly or in clusters. 1

Trichophyton rubrum

2


3

Microsporum gypseum

4

Microsporum canis

5

Trichophyton mentagrophytes Q/Q(M)-474517 Report a Problem

This organism does not produce microconidia. The macroconidia are club shaped, and smooth walled, they grow singly or in clusters. 2


This is the only organism in this list that fits this description. Q/Q(M)-474517 Report a Problem Which of the following organisms causes favus? 1


2


3

Microsporum canis

4

Trichophyton rubrum

5

Microsporum distortum Q/Q(M)-477158 Report a Problem

Which of the following organisms causes favus? 1

Trichophyton schoenleinii 10

Favus is a chronic dermatophyte infection defined by the presence of yellowish crusts in the hair follicles called scutula. Prolonged infections lead to cicatricial alopecias of the scalp and glabrous skin. s kin. The infection is most commonly caused by Trichophyton schoenleinii. Q/Q(M)-477158 Report a Problem Growth of which of the following is not inhibited on Mycosel media? 1

Cryptococcus neoformans

2

Yeast forms of Histoplasma

3

Yeast forms of Blastomyces

4

Microsporum gypseum

5

Scytalidium species

Q/Q(M)-478109 Report a Problem Growth of which of the following is not inhibited on Mycosel media? 4

Microsporum gypseum

Cycloheximide in Mycosel or Mycobiotic media (SDA with cycloheximide and chloramphenicol) inhibits rapidly growing nonpathogenic molds and some pathogens (Cryptococcus neoformans, some Candida species, Prototheca, Scytalidium species, yeast forms of Histoplasma and Blastomyces). Q/Q(M)-478109 Report a Problem

This organism is the most common cause of eumycotic mycetoma in the US: 1

Madurella mycetomatis

2

Nocardia asteriodes

3

Scedosporium apiospermum

4


5

Wangiella dermatitis

This organism is the most common cause of eumycotic mycetoma in the US: 3


Although fairly uncommon, S. apiospermum is the most frequently recovered organism causing eumycotic mycetoma in the US. This name represents the asexual stage of the organism which grows as a filamentous mould, the se xual state, Pseudallescheria boydii, grows as a cleistothecia (round sac containing ascospores). A horticulturist of sphagnum moss topiaries comes in with a nodular eruption with lymphangitic spread and treatment with oral potassium iodide is initiated. What is the most well recognized side effect of this treatment. 1

Gastrointestinal distress

11

2

Shortness of breath

3

Flushing

4

Angioedema

5

Pruritus

A horticulturist of sphagnum moss topiaries comes in with a nodular eruption with lymphangitic spread and treatment with oral potassium iodide is initiated. What is the most well recognized side effect of this treatment. 1

Gastrointestinal distress

This patient has sporotrichosis. Sporotrichosis is mainly an occupational disease of farmers, gardeners, and horticulturists. horticult urists. Persons who handle thorny plants, sphagnum moss, or baled hay are at increased risk. ris k. Outbreaks have occurred in nursery workers who handled sphagnum moss, rose gardeners, children playing on baled hay, and greenhouse workers who handled bayberry thorns contaminated b y the fungus. Classic treatment is with oral potassium iodide for 3-4 weeks. The most recognised side effect of treatment is i s gastrointestinal distress. Thyroid function tests should be performed during treatment as supppression can occur. Q/Q(M)-479615 Report a Problem This organism produces an endothrix tinea capitis: 1


2

Microsporum gypseum

3

Microsporum nanum

4

Trichophyton verrucosum

5

Trichophyton soudanense

Q/Q(M)-474063 Report a Problem This organism produces an endothrix tinea capitis: 5


Only T. soudanense in this group of choices produces an endothrix type of tinea capitis. Trichophyton mentagrophytes, Microsporum nanum and Trichophyton verrucosum produce nonfluorescent ectothrix tinea capit is. Microsporum gypseum may produce a fluorescent or nonfluorescent ectothrix tinea capitis. Q/Q(M)-474063 Report a Problem A blood culture from a neutropenic patient with onychomycosis grew which of the following organism: 1

Scopulariopsis sp

2

Aspergillus sp

3

Fusarium sp

4

Acremonium sp

5

T. rubrum Q/Q(M)-474907 Report a Problem

12

A blood culture from a neutropenic patient with onychomycosis grew which of the following organism: 3

Fusarium sp

Fusarium is one of the few moulds, which yield positive blood cultures, neutropenia is one of the risk factors for Fusariosis. Q/Q(M)-474907 Report a Problem Which of the following causes "black dot ringworm"? 1

M. canis

2

T. violaceum

3

T. verrucosum

4

M. gypseum

5

M. auddouinii

Q/Q(M)-478131 Report a Problem Which of the following causes "black dot ringworm"? 2

T. violaceum

"Black dot ringworm" is endothrix tinea capitis. Black dots are remnants of brittle hair broken at the surface of the scalp (cuticle intact). On KOH prep, spores are seen within the hair shaft. Causes are T. rubrum, r ubrum, T. gourvilli, T. yaounde, T. tonsurans, tonsurans, T. schoeleinii, T. soudanense, and T. violaceum ("Ringo Gave Yoko Two Squeaky Violins."). T. verrucosum causes nonfluorescent ectothrix tinea capitis. M canis, gypseum, and auddouinii also cause ectothrix tinea capitis. Q/Q(M)-478131 Report a Problem Cutaneous lesions of Cryptococcosis may be 1. Nodular 2. Papular 3. Granulomatousulcerative 4. Herpetiform 5. Cellulitis-like: 1

2, 3, 4

2

3, 4, 5

3

2, 3, 4

4

1, 3, 4, 5

5

All of these answers are correct

Q/Q(M)-474490 Report a Problem Cutaneous lesions of Cryptococcosis may be 1. Nodular 2. Papular 3. Granulomatousulcerative 4. Herpetiform 5. Cellulitis-like: 5


Polymorphous lesions have been reported in Cryptococcosis Cr yptococcosis Q/Q(M)-474490 Report a Problem Sabouraud Dextrose Agar (SDA) Emmons Modification contains which of the following? 1

Peptones

2

Phenol red

13

3

Chloramphenicol

4

Gentamicin

5

Cycloheximide

Q/Q(M)-478108 Report a Problem Sabouraud Dextrose Agar (SDA) Emmons Modification contains which of the following? 1

Peptones

SDA Emmons Modification is the gold standard medium. It is nutritionally nutriti onally poor, containing dextrose, peptones, water, and agar, and encourages sporulation. Phenol red, gentamicin, and cycloheximide are found in dermatophyte test media (DTM). Chloramphenicol and cycloheximide are found in Mycosel/Mycobiotic. M ycosel/Mycobiotic. Q/Q(M)-478108 Report a Problem Mycelia can form structures with a comb-lke appearance called: 1

Racket forms

2

Favic chandeliers

3

Pectinate bodies

4

Spiral hyphae

5

Nodular bodies

Q/Q(M)-478104 Report a Problem Mycelia can form structures with a comb-lke appearance called: 3

Pectinate bodies

Racket forms (club-shaped cells), favic chandeliers (terminal hyphal branches having an antler-like appearance), pectinate bodies (hyphae (h yphae resembling a comb), spiral hyphae (hyphae forming corkscrew-like turns), and nodular bodies (knot-like structure of hyphae) are among the types of mycelia. Q/Q(M)-478104 Report a Problem Nondermatophytes growing on Dermatophyte Test Media cause the media to turn what color? 1

Amber

2

Red

3

Yellow

4

Black

5

Green

Q/Q(M)-478112 Report a Problem Nondermatophytes growing on Dermatophyte Test Media cause the media to turn what color? 3

Yellow

Dermatophytes utilize protein as a carbon source producing alkaline by-products causing Dermatophyte Test Media to turn from amber to red. Nondermatophytes 14

cause the media to turn yellow due to acid by-products. b y-products. Q/Q(M)-478112 Report a Problem Which of the following is not true regarding fungal culture media containing cycloheximide? Cycloheximide is not found in Sabouraud Dextrose Agar (SDA) Emmons 1 Modification 2

Cycloheximide is found in Mycosel

3

Cycloheximide is found in Dermatophyte Test Media

4

Cycloheximide is found in Mycobiotic

5

Cycloheximide inhibits bacterial flora

Q/Q(M)-478110 Report a Problem Which of the following is not true regarding fungal culture media containing cycloheximide? 5

Cycloheximide inhibits bacterial flora

Sabouraud Dextrose Agar (SDA) Emmons Modification does not contain cycloheximide. Mycosel/Mycobiotic (SDA with cycloheximide and chloramphenicol) and Dermatophyte Test Media contain cycloheximide. Cycloheximide inhibits rapidly growing nonpathogenic molds and some pathogens (Cryptococcus neoformans, some Candida species, Prototheca, Scytalidium species, yeast forms of Histoplas ma and Blastomyces). Chloramphenicol inhibits bacterial flora. Q/Q(M)-478110 Report a Problem Which of the following statments regarding pseudohyphae is incorrect? 1

Pseudohyphae are seen in yeasts

2

Are constricted at septations

3

Branching occurs at septations

4

The terminal cell is smaller than the others

5

Are not septated

Q/Q(M)-478214 Report a Problem Which of the following statments regarding pseudohyphae is incorrect? 5

Are not septated

Pseudohyphae are seen in yeast and resemble true hyphae except that the y are constricted at septations, branching occurs at septations, and the terminal cell is smaller than the others. They are septated. Q/Q(M)-478214 Report a Problem Trichophyton tonsurans sporulates via thick-walled round cells resistant to the environment known as: 1

Arthroconidia

2

Blastoconidia

3

Chlamydoconidia

4

Sporangia 15

5

Mycelia

Q/Q(M)-478105 Report a Problem Trichophyton tonsurans sporulates via thick-walled round cells resistant to the environment known as: 3

Chlamydoconidia

Chlamydoconidia are thick-walled round cells, resistant to t he environment. Arthroconidia are formed by fragmentation of hyphae, and may appear as thick or thin-walled rectangular cells. Blastoconidia are for med by budding. Sporangia Sporangia are spores that are produced in a sac. Q/Q(M)-478105 Report a Problem Which of the following is true regarding culture of the organisms that cause Pityriasis versicolor? 1

Difficult to grow, requires olive oil overlay

2

Grow easily on Mycosel media

3

Cannot be cultured

4

Grow easily on Dermatophyte Test Media

5

Grow easily on Sabouraud Dextrose Agar

Q/Q(M)-478113 Report a Problem Which of the following is true regarding culture of the organisms that cause Pityriasis versicolor? 1

Difficult to grow, requires olive oil overlay

Pityriasis versicolor (Tinea versicolor) is caused caus ed by Malassezia furfur, M. globosa (most common cause), M. pachydermatis, M. dermatis, M. obtuse, M. restrica, M. sympodialis, and M. sloofiae. The organisms that cause Pityriasis versicolor are difficult to grow. The culture requires olive oil overlay. Q/Q(M)-478113 Report a Problem Medlar bodies are diagnostic of infection with which organism? 1

Blastomycosis

2

Chromomycosis

3

Coccidiomycosis

4

Histoplasmosis

5

Sporotrichosis

Q/Q(M)-475863 Report a Problem Medlar bodies are diagnostic of infection with which organism? 2

Chromomycosis

Chromoblastomycosis, or chromomycosis, is a cutaneous mycosis caused by dematiaceous, or pigmented, fungi. Several fungal species are associated with this infection including Phialophora verrucosa, Fonsecaea pedrosoi, F compactum, Exophiala (Fonsecaea, Wangiella) dermatitidis and Cladosporium carrionii. Infection is typically trauma-induced and involves the lower extremities. Lesions appear as 16

verrucous papules, nodules and plaques, with occasional elephantiasis resulting from lymphatic blockage. Histopathologic findings include pseudoepitheliomatous epidermal hyperplasia and a dermal infiltrate composed of epithelioid histiocytes, multinucleated giant cells, and small clusters cluster s of inflammatory cells including plasma cells, neutrophils, eosinophils and lymphocytes. The characteristic histopathologic feature is the presence of dark brown, thick-walled, ovoid spheres in clusters or chains referred to as "copper pennies" or Medlar bodies. They are visible without the use of special stains. Q/Q(M)-475863 Report a Problem A mass of hyphae is known as a: 1

Sporangia

2

Conidia

3

Mycelium

4

Chlamydoconidia

5

Pseudohyphae

Q/Q(M)-478102 Report a Problem A mass of hyphae is known as a: 3

Mycelium

A mass of hyphae (vegetative tube-like structures) is known as a mycelium. Sporangia, Conidia, and Chlamydoconidia are structures formed through different types of asexual reproduction. Pseudohyphae are seen in yeast. Q/Q(M)-478102 Report a Problem All of the following parameters are used to distinguish dermatophytes except: 1

Nutritional requirements

2

Colony morphology

3

Sucrose hydrolysis

4

Hair fluorescence

5

Growth temperature

Q/Q(M)-477173 Report a Problem All of the following parameters are used to distinguish dermatophytes except: 3

Sucrose hydrolysis

Sucrose hydrolysis is not a useful parameter to dis tinguish dermatophytes from one another. Growth temperature, colony morphology, hair fluorescence and nutritional requirements can be used to identify dermatophytes. Q/Q(M)-477173 Report a Problem A slimy, mucoid colony growing on Sabouraud's agar at 37 degrees Celsius is observed to produce urease. The organism is: 1

Candida albicans

2


3

Candida glabrata 17

4

Candida tropicalis

5

Aspergilus flavus

Q/Q(M)-476962 Report a Problem A slimy, mucoid colony growing on Sabouraud's agar at 37 degrees Celsius is observed to produce urease. The organism is: 2


Cryptococcus neoformans is an encapsulated yeast with a worldwide distribution. Cryptococcosis is usually acquired by inhalation and subsequent dissemination to various organs including the meninges and the skin can occur. Immunosuppressed patients are particularly susceptible to infection. In approximately ten percent of disseminated cases, cutaneous lesions may develop. These present as acneiform papules or pustules and may progress progress to infiltrated plaques, nodules, or ulcers. Less commonly, cutaneous lesions can represent primary cutaneous cr yptococcosis via direct inoculation of organisms into the skin. Diagnosis is made by direct microscopy and India ink stains can aid visualization. visualizati on. The organisms are large, encapsulated budding yeasts. In histopathologic histopathologic sections, capsules stain with alcian blue and mucicarmine stains. In culture, C. neoformans is dist inguished by production of urease as well as the ability to pigment on Guizotia seed medium. Colonies are described as slimy and mucoid. Serologic antigen-detection assays are also available. Treatment of disseminated cryptococcosis includes amphotericin combined with flucytosine. Q/Q(M)-476962 Report a Problem This organism causes a resistant tinea pedis indistinguishable from dermatophytosis: 1

Aspergillus flavus

2


3

Curvularia sp.

4

Scopulariopsis

5

Fonsecaea sp

Q/Q(M)-474494 Report a Problem This organism causes a resistant tinea pedis indistinguishable from dermatophytosis: 2


This fungus is very difficult to treat due to its it s resistance to most antifungals. It is sensitive to cylcoheximide so it should be cultured on media free of this antifungal. Q/Q(M)-474494 Report a Problem Which of the following statements regarding candidal infection is FALSE? 1

Candida species displays true hyphae on potassium hydroxide examination

2

Predisposing factors for candidal infection include diabetes mellitus, hyperhidrosis and broad spectrum antibiotics

3

Candida albicans is the number one cause of mucocutaneous infections

4

Candidal infections typically do not spare the scrotum

5

Candida species may be associated with granuloma gluteale infantum

18

Q/Q(M)-477571 Report a Problem Which of the following statements regarding candidal infection is FALSE? 1

Candida species displays true hyphae on potassium hydroxide examination

Candida species are part of the resident resi dent flora but they are also the most common cause of opportunistic mycotic infection. Cutaneous clinical manifestations include thrush, perleche, paronychia, onychomycosis, onychomycosis, intertrigo, and folliculitis. Candida albicans is the most common organism; however, C. dubliniensis is often implicated in mucosal disease in AIDS patients. C. parapsilosis causes chronic paronychia and C. glabrata is fluconazole resistant. Infection is most common in the extreme of age, and the mucosal disease is prevalent in HIV patients. Factors predisposing patients to infection include impaired mucocutaneous barrier function, immunodeficiencies, broad spectrum antibiotic use, malignancies, heat, humidity, friction, diabetes, and indwelling catheters. Groin infections often involve the scrotum unlike tinea cruris caused by dermatophytes. On KOH examination, budding yeast a nd pseudohyphae (not true hyphae) are diagnostic. Predisposing factors for granuloma gluteale infantum include occlusion, topical corticosteroids, and possibly Candida diaper dermatitis. Q/Q(M)-477571 Report a Problem What organism produces round thick walled spiny macroconidia and pear shaped microconidia? 1

Sporothrix schenckii

2

Blastomyces dermatitidis

3

Paracoccidioides brasiliensis

4


5


Q/Q(M)-474064 Report a Problem What organism produces round thick walled spiny macroconidia and pear shaped microconidia? 5


At room temperature Histoplasma capsulatum produces round thick walled spin y macroconidia and pear shaped microconidia. Q/Q(M)-474064 Report a Problem All of the following are common causes of chromoblastomycosis EXCEPT: 1

Cladosporium carrionii

2

Rhinocladiella aquaspera

3


4

Pseudallescheria boydii

5

Fonsecaea pedrosi

Q/Q(M)-477566 Report a Problem All of the following are common causes of chromoblastomycosis EXCEPT: 4


Chromoblastomycosis is a chronic fungal infection of the skin and the subcutaneous 19

tissue caused by traumatic inoculation of a specific group of dematiaceous (pigmented) fungi. Fonsecaea pedrosoi is the most common causative organism, but Fonecaea compacta, Rhinocladiella aquaspersa, Phialophora verrucosa, Exophilia jeanselmei and Cladosporium carrionii are pathogenic as well. It is found most commonly in agricultural workers in the tropics and subtropics, and it is notoriously resistant to therapy. It presents as verrucous papules and plaques that may coalesce. Histopathological findings include brown, thick-walled cells known described as �copper pennies.� Early in its course, limited disease may respond to surgical excision, electrodessication or cryosurgery. More extensive lesions may require systemic antifungal agents including itraconazole or terbinafine, which are the treatments of choice. Q/Q(M)-477566 Report a Problem All of the following statements about paracoccidioidomycosis are true EXCEPT? 1

It is most common in male agricultural workers

2

It has a characteristic �mariner �s wheel� appearance on histopathology

3

Disease is almost always confined to the skin

4

It is endemic to Brazil

5

It may cause mucocutaneous lesions

Q/Q(M)-477575 Report a Problem All of the following statements about paracoccidioidomycosis are true EXCEPT? 3

Disease is almost always confined to the skin

Paracoccidioidomycosis is caused by Paracoccidioidomycosis brasiliensis, and is endemic to Central and South America, especially Brazil, Argentina, Venezuela, Ecuador and Columbia. Male agricultural workers are at greatest risk. Infection is most commonly caused by direct inoculation which leads to pulmonary disease. Lung disease may be followed by dissemination to mucocutaneous surfaces, gastrointesti nal tract, spleen, adrenal glands, and lymph nodes. Cutaneous lesions are verrucous and/or ulcerative, and usually found on the face and in the nasal and oral mucosa. Primary mucocutaneous disease exists as well and is caused by direct inoculation. Biopsy specimens display multiple narrow-based budding yeast cells, described as a �mariner �s wheel.� The treatment of choice is itraconazole. Q/Q(M)-477575 Report a Problem A 45 year-old agricultural worker from Brazil presented with ulcers of the buccal mucosa and tongue. Cervical lymph nodes were tender and enlarged. The biopsy b iopsy would most likely reveal: Yeast cells in chains and a large thick walled round central yeast cell 1 surrounded by several thinly attached budding smaller yeast cells 2

Yeast cells with large capsules

3

Small budding yeast cells

4

Yeast cells with pseudohyphae

5

Copper pennies Q/Q(M)-474505 Report a Problem

20

A 45 year-old agricultural worker from Brazil presented with ulcers of the buccal mucosa and tongue. Cervical lymph nodes were tender and enlarged. The biopsy b iopsy would most likely reveal: Yeast cells in chains and a large thick walled round central yeast cell 1 surrounded by several thinly attached budding smaller yeast cells Yeast cells in chains and a large thick walled round central yeast cell surrounded by several thinly attached budding smaller yeast cells p.18. This biopsy is describing Paracoccidioides brasiliensis, an organism endemic in Braz il. Its yeast form seen in tissue produces a Mariners wheel-like configuration. Generally this organism is inhaled and disseminates causing mucocutaneous lesions with lymphadenopathy. Q/Q(M)-474505 Report a Problem Choose the correct statement regarding Coccidioidomycosis: 1

The most common form of primary inoculation is cutaneous

2

Dissemination may involve the bones, joints, viscera, brain and skin

3

Causative organism, C. immitits, is a thick-walled spherule with a polysaccharide capsule demonstrated with Alcain blue

4

Erythema nodosum is a poor prognotic sign

5

Outbreaks occur in the Mississippi and Ohio River Valley

Q/Q(M)-478745 Report a Problem Choose the correct statement regarding Coccidioidomycosis: 2

Dissemination may involve the bones, joints, viscera, brain and skin

Coccidioidomycosis: Primary inoculation is pulmonary. Erythema nodosum is a favorable prognostic sighn. Dissemination from the localized pulomary lesions may occur in less than 1% of infections. Target ogans of dissemination include the bones, joints, viscera, brain, meinnges, and skin. The The causative organisms is Coccidioides immitis, is a nonbudding, thick-walled spherule, with a polysaccharide capsule demonstrated with Gridley or Gomori methanamine silver stain. It is endemic in northern Mexico, Venezuela, and in southwest US, especially California Q/Q(M)-478745 Report a Problem Which one of the following agents accounts for the depigmentation seen in pityriasis versicolor? 1

Thymidine kinase

2

Ketoconazole

3

Acetone

4

Dicarbocyclic acid

5

Postinflammatory effect

Q/Q(M)-477188 Report a Problem Which one of the following agents accounts for the depigmentation seen in pityriasis versicolor? 4

Dicarbocyclic acid

Pityriasis versicolor is primarily caused by b y the yeast M. furfur. M. furfur is a dimorphic, lipophilic organism that can produce metabolites such as azaleic acid (a 21

dicarboxylic acid) that can inhibit tyrosinase and injure melanocytes. Q/Q(M)-477188 Report a Problem All of the following statements regarding superficial mycotic infections are true EXCEPT: Trichosporon species can cause systemic disease in immunocompromised 1 patients 2

Malassezia furfur is the most common cause of tinea versicolor

3

Trichosporon beigelii causes white piedra

4

Malassezia species may be associated with neonatal cephalic pustulosis

5

Piedraia hortae causes black piedra

Q/Q(M)-477567 Report a Problem All of the following statements regarding superficial mycotic infections are true EXCEPT: 2

Malassezia furfur is the most common cause of tinea versicolor

Trichosporon asahii can cause disseminated disease in immunocompromised patients, especially those with neutropenia. Patients develop nodular and then necrotic lesions and require systemic antifungal agents. Malassezia globosa is the most common cause of tinea versicolor, not M. furfur. M. pachydermatis, M. dermatis, M. obtuse, M. restrica, M. sympodialis and M. slooffiae are all thought to be medically important as well. M.sympodialis is part of the skin �s normal flora. Trichosporon beigelii and Piedraia hortae are the etiological agents of white and black piedra respectively. Several Malassezia species have been implicated in neonatal cephalic pustulosis (�neonatal acne�). Q/Q(M)-477567 Report a Problem The most common eumycotic organism in the US produces which color grains in its microcolony? 1

White

2

Black

3

Red

4

Yellow

5

Green

Q/Q(M)-482372 Report a Problem The most common eumycotic organism in the US produces which color grains in its microcolony? 1

White

The most common cause of fungal (eumycotic) eumycetoma in the US is Pseudallescheria boydii. This and Acremonium produce white colonies. Black colonies are caused by Exophilia, Madurella, and Curvalaria. Red colonies are cre ated by Actinomadura pelletieri. Yellow colonies are made by Streptomyces Streptomyces and Nocardia, both causes of bacterial mycetoma. Q/Q(M)-482372 Report a Problem Trichosporon ovoides is a cause of: 22

1

Black piedra

2

White piedra

3

Tinea nigra palmaris

4

Ectothrix tinea capitis

5

Endothrix tinea capitis

Q/Q(M)-478114 Report a Problem Trichosporon ovoides is a cause of: 2

White piedra

White piedra is cause by Trichosporon beigelii, or Trichosporon ovoides and T. inkin (new nomenclature). It presents with tan to white soft, nonadherent small concretions ~1mm, seen on the scalp, beard, moustache, and pubic areas. The hairs may fluoresce. Q/Q(M)-478114 Report a Problem A landscape worker complained of several tender nodules on the right dorsal hand and forearm. The biopsy of the lesion showed asteroid bodies but no organisms. The likely diagnosis is: 1

Nocardiosis

2

Blastomycosis

3

Sporotrichosis

4

Candidiasis

5

Coccidioidomycosis

Q/Q(M)-474506 Report a Problem A landscape worker complained of several tender nodules on the right dorsal hand and forearm. The biopsy of the lesion showed asteroid bodies but no organisms. The likely diagnosis is: 3

Sporotrichosis

Sporothrix schenckii produces tiny yeast cells 4-6 um difficult to demonstrate on biopsy unless there is an overwhelming infection. Asteroid bodies are seen on H & E and PAS as radiating fingers of eosinophilic material. Q/Q(M)-474506 Report a Problem This organism is often considered a contaminant but has been reported to cause onychomycosis: 1

Sepedonium

2

Curvularia

3

Scopulariopsis

4

Penicillium

5

Phialophora

Q/Q(M)-474488 Report a Problem This organism is often considered a contaminant but has been reported to cause onychomycosis: 23

3

Scopulariopsis

Causes white superficial onychomycosis. Q/Q(M)-474488 Report a Problem This dermatophyte has a growth requirement for inositol and thiamine 1

Trichophyton equinum

2


3

Trichophyton concentricum

4


5


Q/Q(M)-474525 Report a Problem This dermatophyte has a growth requirement for inositol and thiamine 5


Trichophyton verrucosum is a zoophilic fungus that requires thiamine and sometimes inositol for growth. T. violaceum and tonsurans only have a partial requirement for thiamine. Trichophyton equinum requires niacin. (Horses are nice). Q/Q(M)-474525 Report a Problem A solitary chancre-like lesion appeared on the arm of a florist who has a pet dog. No organisms were seen on biopsy, however Sporothrix schenckii was cultured from the tissue. This infection is known as �fixed cutaneous sporotrichosis�. It remains fixed because: 1

There is a resistance due to a prior exposure

2

There is a decreased resistance due to AIDS

3

The infection was acquired from the dog rather than from a plant

4

The infection occurred in the absence of tissue injury

5

This species of Sporothrix has limited infectivity

Q/Q(M)-474521 Report a Problem A solitary chancre-like lesion appeared on the arm of a florist who has a pet dog. No organisms were seen on biopsy, however Sporothrix schenckii was cultured from the tissue. This infection is known as �fixed cutaneous sporotrichosis�. It remains fixed because: 1

There is a resistance due to a prior exposure

There is a resistance due to a prior exposure. Q/Q(M)-474521 Report a Problem Which actinomycotic organism has red grains? 1

Streptomyces somaliensis

2

Nocardia asteroides

3

Actinomadura madurae

4

Actinomadura pelletieri

24

5


Q/Q(M)-477574 Report a Problem Which actinomycotic organism has red grains? 4

Actinomadura pelletieri

Mycetoma is a granulomatous infection of dermal and subcutaneous tissues usually occurring on the foot. Draining sinuses containing grains characterize such i nfections. Three types of mycetoma exist: eumycotic (true fungal), actinomycotic (fila mentous organisms) and botryomycotic (bacterial infections). Madurella and Leptosphaeria species produce black grains. Pseudallescheria and Acremonium species, along with dermatophytes, make white grains. Nocardia brasiliensis and N. asteroides produce white grains, while Nocardia caviae and Actinomyces israelii tend to have yellowwhite grains. Actinomadura madurae produce pink or white grains and Actinomadura pelleteri make red grains. Streptomyces somaliensis produce brown or yellow yellow grains. Q/Q(M)-477574 Report a Problem Which structure is found in a biopsy of Candida tropicalis, it is branching and pinching in at the points of septations: 1

Septate hyphae

2

Arthroconidia

3

Mosaic fungus

4

Pseudohyphae

5

Pectinate bodies

Q/Q(M)-474502 Report a Problem Which structure is found in a biopsy of Candida tropicalis, it is branching and pinching in at the points of septations: 4

Pseudohyphae

Pseudohyphae are products of yeast, which produce elongated yeast cells that do not pinch off, branching and pinching pinching in at the points of septations. Q/Q(M)-474502 Report a Problem Which of the following stains is NOT used to stain fungal elements? 1

Mucicarmine

2

Periodic Acid Schiff

3

Fontana-Masson

4

Von Kossa

5

Gormori methenamine silver

Q/Q(M)-477578 Report a Problem Which of the following stains is NOT used to stain fungal elements? 4

Von Kossa

Mucicarmine stain is used to stain adenocarcinoma in addition to infectious organisms including Cryptococcus and Rhinosporidium. The Cryptococcus capsule stains red. Periodic Acid Schiff (PAS) is useful in identifying fungi, parasites, gl ycogen and the 25

basement membrane. The wall of the organism stains red. Fontana-Masson Fontana-Masson stains melanin black and therefore helps identify dematiaceous (melanin-producing) fungi. Gormori methenamine silver stains fungi, parasites, Donovan bodies and Rhinoscleroma black. Von Kossa stain is used to identify calcium b y staining it black. Q/Q(M)-477578 Report a Problem This dermatophyte is not an anthropophilic organism: 1

Trichophyton rubrum

2


3

Microsporum gypseum

4


5


Q/Q(M)-474518 Report a Problem This dermatophyte is not an anthropophilic organism: 3

Microsporum gypseum

M. gypseum is a geophilic organism, all others listed are anthropophilic. Q/Q(M)-474518 Report a Problem A 30 year-old male living in the Chicago suburbs complained of a slowly growing verrucous plaque with sharp borders on his left wrist. A biopsy revealed yeast cells 10-14 um. Mucicarmine was negative. A fluffy white colony grew at room temperature having small round conidia on thin conidiophores. The diagnosis is: 1

Blastomycosis

2

Cryptococcosis

3

Candidiasis

4

South American Blastomycosis

5

Histoplasmosis

Q/Q(M)-475927 Report a Problem A 30 year-old male living in the Chicago suburbs complained of a slowly growing verrucous plaque with sharp borders on his left wrist. A biopsy revealed yeast cells 10-14 um. Mucicarmine was negative. A fluffy white colony grew at room temperature having small round conidia on thin conidiophores. The diagnosis is: 1

Blastomycosis

The biopsy describes Blastomyces dermatitidis, the negative mucicarmine rules out Cryptococcus. Chicago is an endemic area ar ea for Blastomyces. The colony morphology also describes Blastomyces. Q/Q(M)-475927 Report a Problem The diagnosis is phaeohyphomycosis, what is the organism 1. Alternaria sp. 2. Bipolaris sp. 3. Fusarium sp. 4. Exophiala sp. 1

1,2,3

2

2,3,4

3

1,2,4 26

4

1,3,4

5


Q/Q(M)-474493 Report a Problem The diagnosis is phaeohyphomycosis, what is the organism 1. Alternaria sp. 2. Bipolaris sp. 3. Fusarium sp. 4. Exophiala sp. 3

1,2,4

All these organisms are dematiaceous, Fusarium is a hyalohyphomycete. Q/Q(M)-474493 Report a Problem The outstanding characteristics of Aspergillus species on biopsy include: 1

Blastoconidia

2

Hyaline, septate dichotomously branching hyphae

3

Copper pennies

4

Ribbon-like filaments that may be twisted and distorted branching at right angles

5

Stain with Fontana-Mason stain

Q/Q(M)-474512 Report a Problem The outstanding characteristics of Aspergillus species on biopsy include: 2

Hyaline, septate dichotomously branching hyphae

Aspergillus is seen as wide (3 um) septate septat e dichotomously branching (45� angles) hyphae. Q/Q(M)-474512 Report a Problem A patient with white nodules on the hair shaft has a KOH which shows hyphae and arthroconidia. The etiology is: 1

Corynebacterium minutissimum

2

Exophiala wernickii

3

Piedraia hortae

4

Trichosporon beigelii

5

Corynebacterium tenuis

Q/Q(M)-477143 Report a Problem A patient with white nodules on the hair shaft has a KOH which shows hyphae and arthroconidia. The etiology is: 4


White piedra is an infection of the hair shaft caused by Trichosporon beigelii. Unlike black piedra which is firmly adherent to the shaft, white piedra presents as light brown nodules composed composed of hyphae and arthroconidia, which move easily along the hair shaft. The most common sites of infection occur on the mustache, beard and pubic area. Q/Q(M)-477143 Report a ProblemOf ProblemOf the following Candida species, which is likely to cause disseminated Candidiasis with cutaneous lesions?

27

1

Candida albicans

2

C. parapsilosis

3

C. tropicalis

4

C. krusei

5

C. neoformans

Q/Q(M)-474500 Report a Problem Of the following Candida species, which is likely to cause disseminated Ca ndidiasis with cutaneous lesions? 3

C. tropicalis

C. albicans is responsible for approximately 50% of all Candidemia, but C. tropicalis is seen with increasing frequency among patients with disseminati on and cutaneous manifestations. Q/Q(M)-474500 Report a Problem A 6 year-old Hispanic girl came into the clinic with a history of alopecia and scaly scalp for 3 weeks. The Wood's lamp examination was negative and her cervical lymph nodes were not enlarged. It was noted that the hairs were broken off at the surface of the scalp. The most likely li kely organism to be isolated would be: 1

M. audouinii

2

M. canis

3

M. gypseum

4

T. tonsurans

5

T. rubrum

Q/Q(M)-474013 Report a Problem A 6 year-old Hispanic girl came into the clinic with a history of alopecia and scaly scalp for 3 weeks. The Wood's lamp examination was negative and her cervical lymph nodes were not enlarged. It was noted that the hairs were broken off at the surface of the scalp. The most likely li kely organism to be isolated would be: 4

T. tonsurans

T. tonsurans causes the endothrix infection "Black Dot Ringworm". All other choices cause Grey Patch Ringworm. Q/Q(M)-474013 Report a Problem Which of the following statements about dimorphic fungi is INCORRECT? 1

Are in the mould form in the environment

2

Are in yeast/spherule form in tissue

3

Are in mould form at 25 degrees C

4

Are in yeast/spherule form at 37 degrees C

5

Are in mould form in tissue

Q/Q(M)-478213 Report a Problem Which of the following statements about dimorphic fungi is INCORRECT? 28

5

Are in mould form in tissue

Yeasts and moulds are not mutually exclusive. Dimorphism can occur - a dimorphic fungus will be in a mould form in the environment at 25 degrees and in a yeast/spherule form at 37 degrees C. Q/Q(M)-478213 Report a Problem Although this organism is not a fungus, it stains with PAS and GMS and produces spherules in tissue. This organism can be identified as: 1

Rhinosporidium seeberi

2


3

Penicillium marneffei

4

Prototheca wickerhami

5

Leishmania mexicana

Q/Q(M)-474065 Report a Problem Although this organism is not a fungus, it stains with PAS and GMS and produces spherules in tissue. This organism can be identified as: 4

Prototheca wickerhami

This achloic algae produces spherules or sporangia 8-20um in tissue. The mature form is called a morula. Q/Q(M)-474065 Report a Problem Which of the following DOES NOT typically cause white superficial onychomycosis? 1

Aspergillus species

2

Fusarium species

3


4

Scopulariopsis species

5

Trichophyton rubrum

Q/Q(M)-477573 Report a Problem Which of the following DOES NOT typically cause white superficial onychomycosis? 5

Trichophyton rubrum

In white superficial onychomycosis, the organism only invades the superficial nail plate, and it clinically appears as chalky white patches on the nails. The most common organism is T. mentagrophytes, but Aspergillus, Cephalosporium, Fusarium, Acreconium and Scopulariopsis are implicated as well. Q/Q(M)-477573 Report a Problem A 56-year-old male with HIV presents with multiple umbilicated brown papules on the face. Which of the following is the least likely cause of his lesions? 1

Cryptococcus

2

Histoplasmosis

3

Coccidiomycosis

4

Penicilliosis 29

5

Blastomycosis

Q/Q(M)-482329 Report a Problem A 56-year-old male with HIV presents with multiple umbilicated brown papules on the face. Which of the following is the least likely cause of his lesions? 5

Blastomycosis

This patient has molluscum-like lesions on the face in the setting of immunosuppression. The differential for such papules includes cryptococcus, histoplasmosis, coccidiomycosis, and penicilliosis. Blastomycosis can cause sporotrichoid lesions, warty vegetations, papillomatous proliferations, and osteomyelitis; it usually does not produce molluscum-type papules. Q/Q(M)-482329 Report a Problem A 12 year old boy has a pruritic bullous eruption on his feet. A KOH is positive and a fungal culture shows microconidia in grape-like clusters. The etiology is: 1


2

Microsporum canus

3


4

Microsporum gypseum

5


Q/Q(M)-477351 Report a Problem A 12 year old boy has a pruritic bullous eruption on his feet. A KOH is positive and a fungal culture shows microconidia in grape-like clusters. The etiology is: 3


Trichophyton mentagrophytes mentagrophytes is the dermatophyte primarily responsible for bullous tinea pedis. It typically has septate, spiral hypahe with cigar or grape like thin-walled microconidia. Q/Q(M)-477351 Report a Problem A 49-year-old man has painless subcutaneous nodules on his feet with sinus tracts and abscesses. Pathology shows "grain" in sinus tract drainage. A diagnosis of eumycotic mycetoma is made. What is the most common cause in the United States? 1

Acremonium

2

Curvalaria

3

Exophilia jeanselmei

4


5

Nocardia

Q/Q(M)-482371 Report a Problem A 49-year-old man has painless subcutaneous nodules on his feet with sinus tracts and abscesses. Pathology shows "grain" in sinus tract drainage. A diagnosis of eumycotic mycetoma is made. What is the most common cause in the United States? 4


Eumycotic mycetoma is fungal and can be caused by Pseudallescheria boydii (most 30

common in US), Madurella, Acremonium, curvalaria, and Exophilia jeanselmei. Actinomycotic mycetoma is bacterial and maybe caused by Nocardia asteroids or brasiliensis, Streptomyces, and Actinomyces. Q/Q(M)-482371 Report a Problem Which of the following is the most useful morphologic feature in identifying the mycelial phase of Histoplasma capsulatum? 1

Arthroconidia in every other cell

2

Encapsulated spores 2-5 um

3

Tuberculate macroconidia 8-14 um

4

Small oval conidia on long thin conidiophores

5

Microconidia laterally along the hyphae strand

Q/Q(M)-474514 Report a Problem Which of the following is the most useful morphologic feature in identifying the mycelial phase of Histoplasma capsulatum? 3

Tuberculate macroconidia 8-14 um

On artificial media the mould form of Histoplasmosis produces hyphae with tear drop microconidia and round thick wall tuberculate macroconidia. Q/Q(M)-474514 Report a Problem Which of the following statements regarding lobomycosis is FALSE? 1

Itraconazole is the treatment of choice

2

It resembles a �chain of coins� on histopathology

3

It is also known as �keloidal blastomycosis�

4

Lacazia (formerly Loboa) loboi is the number one cause

5

The infection also occurs in dolphins

Q/Q(M)-477576 Report a Problem Which of the following statements regarding lobomycosis is FALSE? 1

Itraconazole is the treatment of choice

Lobomycosis, also know as keloidal blastomycosis is caused by Lacazia loboi (formerly Loboa loboi). It is endemic to Brazil and the Caribbean and is associated with dolphins. Clinically, the disease presents with painless keloidal papules and plaques, ulcerative lesions and/or verrucous lesions. Biopsy specimens display multiple budding thick-walled cells attached with a bridge, often ref erred to as a �chain of coins. � Surgical treatment is necessary as antifungal medications are ineffective. Q/Q(M)-477576 Report a Problem Which of the following organisms would you expect to recover from a fluorescent tinea capitis? 1

T. tonsurans

2

M. gypseum

3

M. canis and M. gypseum 31

4

T. violaceum

5

T. rubrum

Q/Q(M)-474495 Report a Problem Which of the following organisms would you expect to recover from a fluorescent tinea capitis? 3

M. canis and M. gypseum

M. gypseum may occasionally produce a dull fluorescence - all other or ganisms are nonfluorescent. Q/Q(M)-474495 Report a Problem Which of the following most accurately describe conidia? 1

Cells produced on the end or sides of hypha or conidiophore

2

Spores that are produced in a sac

3

Thick-walled round cell

4

Formed by budding

5

Formed by fragmentation of hyphae

Q/Q(M)-478217 Report a Problem Which of the following most accurately describe conidia? 1

Cells produced on the end or sides of hypha or conidiophore

Conidia are cells produced on the end or sides of hypha or conidiophore, the size and shape arrangement are generally characteristic characterist ic of the organism. The remaining descriptions are of specific types of conidia. Spores produced in a sac are sporangia, thick-walled round cells that are resistant resista nt to the environment are chlamydoconidia, blastoconidia are formed by budding budding and arthroconidia are formed by fragmentation of hyphae. Q/Q(M)-478217 Report a Problem The etiologic agent responsible for White Piedra is: 1

Candida albicans

2

Pityrosporum obiculare

3

Corynebacterium tenuis

4

Piedra hortai

5

Trichosporon ovoides

Q/Q(M)-474499 Report a Problem The etiologic agent responsible for White Piedra is: 5


Formerly known as T. beigelii. Q/Q(M)-474499 Report a Problem What is the most frequently reported cause of primary cutaneous asper gillosis? 1

Aspergillus flavus

2

Aspergillus fumigatus 32

3

Aspergillus niger

4

Aspergillus solani

5

Aspergillus marneffei

Q/Q(M)-477452 Report a Problem What is the most frequently reported cause of primary cutaneous asper gillosis? 1

Aspergillus flavus

Primary cutaneous aspergillosis is a rare disease dis ease reported mostly frequently in children with hematologic malignancies who developed skin lesions at the site of IV canulas. Q/Q(M)-477452 Report a Problem Penicillium marneffei is an infection endemic to which part of t he world? 1

Mexico

2

South America

3

Africa

4

Southeast Asia

5

The Caribbean

Q/Q(M)-475870 Report a Problem Penicillium marneffei is an infection endemic to which part of t he world? 4

Southeast Asia

Penicillosis is a recently recognized disease caused by infection with Penicillium marneffei, a dimorphous fungus that is contracted through inhalation. Cases have been described in Vietnam, China, and Thailand Thailand as well as imported cases in the U.S. in veterans returning from Vietnam. Bamboo rats in these areas have been shown to be infected with P. marneffei and may represent a reservoir. Although penicillosis has a tendency to occur in immunocompromised hosts opportunistically, it has also been described in normal hosts. Clinical presentation is typically with pulmonary or disseminated disease which can affect the t he skin, gastrointestinal tract, spleen, l ymph nodes, skin, and bone marrow. Cutaneous features include multiple umbilicated papules which can enlarge and ulcerate occurring commonly on on the face and trunk. Diagnosis is by culture or histopathology. Treatment is with itraconazole. Severe cases may require amphotericin B. Q/Q(M)-475870 Report a Problem A creamy white colony might be any of these organisms except: 1

Candida albicans

2

Prototheca wickerhamii

3

Curvularia

4

Sporothrix schenckii at 37 � C

5


Q/Q(M)-474492 Report a Problem A creamy white colony might be any of these organisms except: 33

3

Curvularia

Is a dematiaceous organism and is the only organism list ed that does not produce creamy white colonies. Q/Q(M)-474492 Report a Problem Which of the following statements regarding histoplasmosis is TRUE? 1

Terbinafine is the treatment of choice

2

Histoplasma capsulatum is a yeast at 25�C

3

The organisms are intracellular on histological examination

4

The disease is most common in the San Joaquin Valley

5

The disease is primarily a mucocutaneous infection

Q/Q(M)-477577 Report a Problem Which of the following statements regarding histoplasmosis is TRUE? 3

The organisms are intracellular on histological examination

Histoplasmosis is primarily a pulmonary infection that can disseminate to other organs. It is endemic to the Ohio, Missouri and Missis sippi River Valleys where the bird and bat droppings droppings in the soil contain the fungus. Primary cutaneous disease disease is extremely rare. At 25�C it displays septate hyphae and at 37 �C H. capsulatum is a yeast. Itraconazole is the treatment of choice. On histopathological examination, intracellular organisms that display a halo are seen. The halo is not the result of a capsule but rather shrinkage artifact. Q/Q(M)-477577 Report a Problem Which of the following methods of direct microscopic examination is chitin specif ic? 1

Chlorazol black E

2

Calcofluor white

3

Gomori Methenamine Silver

4

Fontana-Masson

5

KOH

Q/Q(M)-478106 Report a Problem Which of the following methods of direct microscopic examination is chitin specif ic? 1

Chlorazol black E

Chlorazol black E is chitin specific. Calcofluor white is glucan specific. Gomori Methenamine Silver (GMS) and Fontana-Masson are histology stains. KOH is a rapid, easy, reliable method for diagnosing fungal infections, but is not chitin-specific. Q/Q(M)-478106 Report a Problem Which pathogen is not inhibited by cycloheximide? c ycloheximide? 1

Cryptococcus

2

Candida albicans

3

Prototheca

4

Scopuloniopsos brevicaulis 34

5

Scytalidium species

Q/Q(M)-476756 Report a Problem Which pathogen is not inhibited by cycloheximide? c ycloheximide? 2

Candida albicans

Cycloheximide is used is fungal culture media to reduce contaminants. Q/Q(M)-476756 Report a Problem Which dermatophyte is most commonly responsible for tinea corporis gladiotorum? 1

T. mentag

2

T. tonsurans

3

T. schonlenleinii

4

T. rubrum

5

E. floccosum

Q/Q(M)-476550 Report a Problem Which dermatophyte is most commonly responsible for tinea corporis gladiotorum? 2

T. tonsurans

Tinea corporis gladiotorum is caused by Trychophyton tonsurans. Clinically, it appears as well-defined, scaly plaques usually usuall y located on the arms, neck, and head. Q/Q(M)-476550 Report a Problem Which of the following dermatophytes causes endothrix tinea capitis? 1

Microsporum gypseum

2


3


4

Microsporum canis

5

Microsporum ferrugineum

Q/Q(M)-477570 Report a Problem Which of the following dermatophytes causes endothrix tinea capitis? 3


Organisms that cause an ectothrix pattern of tinea ti nea capitis include M. canis, M. audouinii, M. ferruginosum, M. distortium, M. gypseum and occas ionally T. rubrum. T. tonsurans, T. violaceum, T. soudanense, T. gourvilli, T. yaoundei, and occasionally T. rubrum cause an endothrix pattern. T. schoenleinii causes favus in which hyphae and air spaces are seen in the hair shaft. A bluish-white fluorescence pattern is seen with Wood �s lamp. Clinically, patients have thick, yellow, cup-shaped crusts (scutula); scarring and secondary infection may result. M. canis, M. audouinii, M. ferruginosum, M. distortium display a yellow fluorescence on Wood �s lamp examination. Q/Q(M)-477570 Report a Problem All of the following are features of mycetoma m ycetoma except: 1

Swelling

35

2

Self-limited

3

Granules

4

Fascia and bone involvement

5

Draining sinuses

Q/Q(M)-477230 Report a Problem All of the following are features of mycetoma m ycetoma except: 2

Self-limited

Mycetomas may be subdivided into eumycetoma and actinomycetoma . Mycetomas generally begin as subcutaneous swellings occurring on the feet. Later, sin uses, granules, and nodules may be seen. The skin and subcutaneous tissue may also become involved. Treatment is difficult in later stages. Q/Q(M)-477230 Report a Problem Septate true hyphae are characterized by: 1

Transverse cross walls forming within the hyphae

2

Discrete unicellular bodies

3

Constrictions at septations

4

Branching occuring at septations

5

A terminal cell that is smaller than the others

Q/Q(M)-478103 Report a Problem Septate true hyphae are characterized by: 1

Transverse cross walls forming within the hyphae

Hyphae are vegetative tube-like structures. In septate hyphae, transverse cross walls form within the hyphae. Pseudohyphae, seen in yeast, resemble true hyphae except that they are constricted at septations, septa tions, branching occurs at septations, and the terminal cell is smaller than the others. Q/Q(M)-478103 Report a Problem Which of the following causes tinea imbricata? 1


2


3

Trichophyton rubrum

4


5


Q/Q(M)-477572 Report a Problem Which of the following causes tinea imbricata? 2


Tinea imbricata is characterized by concentric, annular, scaly rings resembling erythema annulare centrifugum. The causative agent is T. concentricum, which is endemic to the South Pacific, South and Central America and Asia. The infecti on is usually chronic. 36

Q/Q(M)-477572 Report a Problem This 16 year-old patient was recently diagnosed with HIV, the diagnosis is: 1

Distal Onychomycosis

2

Proximal Subungual Onychomycosis

3

Proximal White Subungual Onychomycosis

4

White Superficial Onychomycosis

5

Paronychia with Candida Onychomycosis

Q/Q(M)-475928 Report a Problem This 16 year-old patient was recently diagnosed with HIV, the diagnosis is: 3

Proximal White Subungual Onychomycosis

Proximal White Subungual onychomycosis is an AIDS marker, nails have a characteristic white opaque appearance beginning in the region of the lunula and extending distally under the nail plate. Q/Q(M)-475928 Report a Problem Yeast: 1

Are filamentous fungi

2

Are characterized by tubular branching cells

3

Form fuzzy colonies

4

Form smooth colonies

5

Are unicellular oval to round cells that reproduce by budding or fission

Q/Q(M)-478212 Report a Problem Yeast: 5

Are unicellular oval to round cells that reproduce by budding or fission

All of the listed features are those of molds. Yeast are unicellular, oval to round cells that reproduce by budding or fission. They The y form moist colonies, not smooth or fuzzy colonies. Q/Q(M)-478212 Report a Problem Which one of the following is not caused by a Candida infection? 1

Angular cheilitis

2

Balanitis

3

Median rhomboid glossitis

4

Leukoplakia

5

Mycetoma

Q/Q(M)-477380 Report a Problem Which one of the following is not caused by a Candida infection? 5

Mycetoma

Candidal infections may clinically present as thrush/leukoplakia, perleche/angular cheilitis, vulvovaginitis, balanitis, paronychia, onychomcosis, intertrigo, a nd 37

folliculititis. Median rhomboid glossitis is now also associated with candidal infections. Mycetomas are caused by true fungi (eumycetoma) or filamentous bacteria (actinmycetoma). Q/Q(M)-477380 Report a Problem Which of the following usually does not fluoresce bright green upon Woods lamp l amp examination? 1

M. audouinii

2

M. canis

3

T. violaceum

4

T. schoenleinii

5

M. distortum

Q/Q(M)-478740 Report a Problem Which of the following usually does not fluoresce bright green upon Woods lamp l amp examination? 3

T. violaceum

Fluorescent-positive infections are caused by:"Dogs And Cats Fight Some Gypsies" M. Distortum M. audouinii M canis M. ferrugineum T. schoenleinii M. gypsium (occasionally) Q/Q(M)-478740 Report a Problem Erythematous to violaceous papules that may progress to nodular and necrotizing skin lesions in neutropenic patients may be caused by which of the following organisms? 1

Trichosporon asahii

2


3


4

Trichosporon inkin

5

Trichophyton rubrum

Q/Q(M)-478115 Report a Problem Erythematous to violaceous papules that may progress to nodular and necrotizing skin lesions in neutropenic patients may be caused by which of the following organisms? 1

Trichosporon asahii

Trichosporon asahii can cause trichosporanosis, which presents with diss eminated disease in neutropenic patients. Patients may present with erythematous to violaceous papules that may progress to nodular and necrotizing skin lesions. Trichosporon beigelii (new nomenclature: Trichosporon ovoides ovoides and Trichosporon inkin) causes white piedra and other superficial infections. Q/Q(M)-478115 Report a Problem A child presents with several yellowish, cup-shaped crusts on the scalp, some with single hairs piercing through the center. KOH prep reveals arthroconidia a nd airspaces within the hair shaft. A likely cause is: 1

M. gypseum

38

2

M. canis

3

T. tonsurans

4

T. verrucosum

5

T. mentagrophytes

Q/Q(M)-478133 Report a Problem A child presents with several yellowish, cup-shaped crusts on the scalp, some with single hairs piercing through the center. KOH prep reveals arthroconidia a nd airspaces within the hair shaft. A likely cause is: 1

M. gypseum

This child is presenting with the characteristic characteristi c scutula of favus. Favus is most often caused by T. schoenleinii, T. violaceum, and M. gypseum. Q/Q(M)-478133 Report a Problem Which of the following statements about arthroconidia is correct? 1

Arthroconidia are formed by budding

2

Arthroconidia are formed by fragmentation of hyphae

3

Arthroconidia are thick-walled round cells

4

Arthroconidia are spores that are produced in a sac

5

Arthroconidia are yeast forms of dimorphic fungi

Q/Q(M)-478216 Report a Problem Which of the following statements about arthroconidia is correct? 2

Arthroconidia are formed by fragmentation of hyphae

Arthroconidia are formed by fragmentation of hyphae and may appear as thick or thin walled rectangular cells. An example would be the mould form of Coccidioides immitis. The remaining options are incorrect. Q/Q(M)-478216 Report a Problem A patient has a positive Wood's light exam that is caused by pteridine. What is the causative condition? 1


2

Corynebacterium

3


4

Pseudomonas

5


Q/Q(M)-482334 Report a Problem A patient has a positive Wood's light exam that is caused by pteridine. What is the causative condition? 1


Wood's light positive dermatophytes (M. canis, M. audouinii, M. distortum, M. ferrugineum, M gypseum, and T. schoenleinii) fluoresce secondary to pteridine. Corynebacterium can fluoresce as well due to coproporphyrin III. Pseudomonas 39

fluoresces from production of pycyanin. The other organisms do not react with a Wood's light. Q/Q(M)-482334 Report a Problem Which of the following is a fluorescent ectothrix dermatophyte? 1

Trichophyton rubrum

2


3


4


5

Microsporum nanum

Q/Q(M)-478129 Report a Problem Which of the following is a fluorescent ectothrix dermatophyte? 3


Fluorescent ectothrix dermatophytes include M. canis, M. audouinii, M. distortum, M. ferrugineum, and sometimes M. gypseum and T. schoenleinii ("Cats And Dogs Fight and Growl Sometimes.") Nonfluorescent ectothrix dermatophytes include T. mentagrophytes, T. rubrum, T. verrucosum, T. megninii, and M. nanum. Endothrix dermatophytes include T. rubrum, T. gourvilli, T. yaounde, T. tonsurans, T. schoenleinii, T. soudanense, and T. violaceum. Q/Q(M)-478129 Report a Problem Which of the following stains is specific for chitin? 1

KOH

2

KOH with DMSO

3

Swartz Lamkins

4

Chlorazol Black E

5

Calcofluor White

Q/Q(M)-478220 Report a Problem Which of the following stains is specific for chitin? 4

Chlorazol Black E

Chlorazol Black E is a chitin specific stain. The remaining options are useful in direct microscopic examination for fungal elements, but are not chitin specific. Q/Q(M)-478220 Report a Problem Two weeks after a bicycle accident a 25-year-old female diabetic patient complained of a swollen tender right cheek The PAS biopsy demonstrated ring forms and distorted wide hyphae with few septations and right angle branching. The diagnosis is: 1

Aspergillosis

2

Actinomycosis

3

Mucormycosis

4

Dermatophytosis

40

5

Fusariosis

Q/Q(M)-474487 Report a Problem Two weeks after a bicycle accident a 25-year-old female diabetic patient complained of a swollen tender right cheek The PAS biopsy demonstrated ring forms and distorted wide hyphae with few septations and right angle branching. The diagnosis is: 3

Mucormycosis

Having diabetes is a risk factor for Mucormycosis, ring forms in the biopsy are the xsection of the wide sparsely septate hyphae. Q/Q(M)-474487 Report a Problem Cryptococcus neoformans resides in: 1

The Mississippi Valley region

2

Chicken roosts

3

Pigeon droppings

4

Sandy soil

5

None of these answers are correct

Q/Q(M)-474513 Report a Problem Cryptococcus neoformans resides in: 3

Pigeon droppings

This organism is ubiquitous and is abundant in soil enriched with pigeon droppings. Q/Q(M)-474513 Report a Problem A fungal culture demonstrates a suedelike cream-colored colony of teardrop and balloon-shaped microconidia which produce produce a red-brown pigment. Which of the following is true of this organism? 1

Causes ectothrix infection

2

Requires partial thiamine for growth

3

Does not have arthroconidia

4

Causes fluorescent hair infection

5

Is not a cause of tinea unguim

Q/Q(M)-477216 Report a Problem A fungal culture demonstrates a suedelike cream-colored colony of teardrop and balloon-shaped microconidia which produce produce a red-brown pigment. Which of the following is true of this organism? 2

Requires partial thiamine for growth

Trichophyton tonsurans is an anthropophilic dermatophyte that causes non-fluorescent endothrix hair invasion. It can cause black dot tinea capitis, tinea corporis, tinea pedis, and tinea unguium. An important identifying feature of T. tonsurans is its red-brown pigment that diffuses into the medium. Also, abundant abundant tear-drop or club shaped microconidia can be found. It grows best in the presence of thiamine. Q/Q(M)-477216 Report a Problem 41

This agent causes a superficial, asymptomatic infection usually on the palms of the hands. The lesions are flat, nonscaly and appear as irr egularly shaped brown macules: 1

Piedra hortae

2

Cladosporium carrionii

3

Aureobasidium pullulans

4

Phaeoannellomyces werneckii

5

Exophiala jeanselmei

Q/Q(M)-474503 Report a Problem This agent causes a superficial, asymptomatic infection usually on the palms of the hands. The lesions are flat, nonscaly and appear as irr egularly shaped brown macules: 4

Phaeoannellomyces werneckii

These lesions often have a deeper pigment at the advancing border. The other organisms are dematiaceous but are not the etiologic agent of tinea nigra. Q/Q(M)-474503 Report a Problem Which of the following is true regarding Dermatophyte Test Media (DTM)? 1

DTM contains chlortetracycline and minocycline

2

Alizarin red is the indicator present in DTM

3

Non-dermatophytes cause the media to turn yellow due to acid byproducts

4

DTM is useful for culturing dermatophytes from skin and nails, but not hair.

5

Dermatophytes utilize glucose as a carbon source, producing alkaline by products.

Q/Q(M)-478111 Report a Problem Which of the following is true regarding Dermatophyte Test Media (DTM)? 3

Non-dermatophytes cause the media to turn yellow due to acid byproducts

Dermatophyte Test Media (DTM) contains peptones, dextrose, gentamicin, chlortetracycline, cycloheximide, and phenol red. Dermatophytes utilize protein as a carbon source producing alkaline byproducts causing the media to turn from amber to red. Nondermatophytes cause the media to turn yellow due to acid byproducts. Q/Q(M)-478111 Report a Problem A whitish, heaped and convoluted colony with growth submerged into the agar and a colorless reverse was isolated from the scalp of a 35-year-old male. The organism did not produce any conidia. The diagnosis most likely is: 1

Microsporum canis

2


3

Trichophyton rubrum

4


5

Trichophyton schoenleinii Q/Q(M)-474489 Report a Problem

42

A whitish, heaped and convoluted colony with growth submerged into the agar and a colorless reverse was isolated from the scalp of a 35-year-old male. The organism did not produce any conidia. The diagnosis most likely is: 5


Produces a white cerebriform colony lacking any conidia. M. ferrugineum produces a rust colored colony with bamboo-like hyphae without c onidia. The other organisms produce micro and macroconidia. Q/Q(M)-474489 Report a Problem A 37 year old woman from New Mexico, now 30 weeks pregnant, presents with flulike symptoms. Chest x-ray revealed diffuse miliary infiltrates, with blood cultures growing Coccidioidis immitis. What is the treatment of choice? 1

Amphotericin B

2

Terbinafine

3

Itraconazole

4

Griseofulvin

5

No therapy

Q/Q(M)-482494 Report a Problem A 37 year old woman from New Mexico, now 30 weeks pregnant, presents with flulike symptoms. Chest x-ray revealed diffuse miliary infiltrates, with blood cultures growing Coccidioidis immitis. What is the treatment of choice? 1

Amphotericin B

There is an increased risk of dissemination of Coccidiomycosis in pregnant women, especially during the third trimester and the post-part um period. In a review by Crum et al, maternal demise correlated correlat ed with disease diagnosed later in pregnancy, with only 45% of patients diagnosed in the third trimester surviving (Am J Medicine 2006;119(11):Pages 993.e11-993.e17). 993.e11-993.e17). Given that azoles have been shown to cause teratogenicity, amphotericin B is recommended as the therapy in pregnant women. Q/Q(M)-482494 Report a Problem Which of the following is NOT used for histologic examination for fungal infection? 1

Chlorazol Black-E

2

Gormori Methanamine Silver

3

Periodic Acid Schiff

4

Fontana-Masson

5

Mayer's mucicarmine

Q/Q(M)-478219 Report a Problem Which of the following is NOT used for histologic examination for fungal infection? 1

Chlorazol Black-E

Chlorazol Black-E is a stain specific for chitin and is used in direct examination, not histologic preparations. The remaining options are histology stains useful in fungal identification in tissue. Q/Q(M)-478219 Report a Problem 43

What is the most likely cause of this infection? 1

T. tonsurans

2

T. schoenleinii

3

M. canis

4

T. mentag

5

T. rubrum

Q/Q(M)-476870 Report a Problem What is the most likely cause of this infection? 3

M. canis

M. canis and T. tonsurans both cause tinea capitis. M. cains is more commonly associated with inflammatory tinea capitis and kerion formation. Q/Q(M)-476870 Report a Problem An elderly lady with moccasin-type tinea pedis has a fungal culture which demonstrates smooth, teardrop-shaped microconidia which produce a � port-wine� pigment. The organism is: 1


2

Microsporum canus

3

Trichophyton rubrum

4

Microsporum gypseum

5


Q/Q(M)-477365 Report a Problem An elderly lady with moccasin-type tinea pedis has a fungal culture which demonstrates smooth, teardrop-shaped microconidia which produce a � port-wine� pigment. The organism is: 3

Trichophyton rubrum

Trichophyton rubrum is an anthropophilic anthropophilic dermatophyte that is a cause of T. pedis, T. manum, T. corporis, T. cruris, onychomycosis, Majocchi �s granuloma, and rarely T. capitis. Colonies appear as fluffy to granular white t o cream colored with reverse nondiffusible port-wine or red pigment. Macroconidia are rare, thin-walled pencil shaped. Microconidia are delicate teardrop shaped. Q/Q(M)-477365 Report a Problem Clinically, actinomycotic mycetoma and eumycotic mycetoma appear identical. The importance of identifying the etiologic agent is 1

Academic

2

Selecting the appropriate therapy

3

Ordering appropriate stains

4

Determine if the infection is contagious

5

Determine if amputation is necessary Q/Q(M)-474520 Report a Problem 44

Clinically, actinomycotic mycetoma and eumycotic mycetoma appear identical. The importance of identifying the etiologic agent is 2

Selecting the appropriate therapy

The etiologic agents of actinomycotic mycetoma are filamentous bacteri a that require antibiotics, whereas fungal agents causing eumycotic mycetoma require antif ungal therapy. Q/Q(M)-474520 Report a Problem The organism that causes white piedra: 1

Does not cause onychomycosis

2

Is known as Piedraia hortae

3

May also cause post-operative wound infections

4

Grows as small, compact, black-greenish velvety colonies

5

Can only be treated by cutting off affected hairs

Q/Q(M)-478116 Report a Problem The organism that causes white piedra: 3

May also cause post-operative wound infections

Trichosporon beigelii (new nomenclature: Trichosporon ovoides and Trichosporon inkin) causes white piedra as well as other superficial infections, including postoperative wound infections, paronychia, and onychomycosis. It grows as cream to yellow-colored pasty colonies when cultured. Treatment is with topical amphotericin B lotion, benzoic acid, salicylic acid, or cutting off affected hair. Black piedra is caused by Piedraia hortae, which grows as small, compact, black- greenish velvety colonies when cultured, and can be treated only by cutting off affected hairs . Q/Q(M)-478116 Report a Problem Which of the following methods of direct microscopic examination for fungi is glucan specific? 1

KOH

2

Swartz Lamkins

3

Chlorazol black E

4

Calcofluor white

5

Mayer's mucicarmine

Q/Q(M)-478107 Report a Problem Which of the following methods of direct microscopic examination for fungi is glucan specific? 4

Calcofluor white

Calcofluor white is a glucan specific stain. Chlorazol black E is chitin specific. KOH is a rapid, easy, reliable method of diagnosing fungal infections but is not glucan specific; Swartz Lamkins contains a counterstain but is not glucan specific. Mayer's mucicarmine is a histology stain. Q/Q(M)-478107 Report a Problem Which of the following is FALSE with regards to asexual reproduction of fungi? 45

1

Arthroconidia are formed by the fragmentation of hyphae

2

Sporangia are spores that are produced in a sac

3

Chlamydoconidia are thin-walled and are susceptible to environmental injury

4

Conidia are cells produced on the sides or ends of hyphae

5

Dematophytes produce conidia

Q/Q(M)-477564 Report a Problem Which of the following is FALSE with regards to asexual reproduction of fungi? Chlamydoconidia are thin-walled and are susceptible to environmental 3 injury The structures formed during asexual propagation of fungi are termed either spores or conidia depending on their mode of production and they arise following mitosis of a parent nucleus. Conidia arise either by budding budding off conida-producing hyphae hyphae (on the sides or ends) or by differentiation of preformed hyphae. The size and shape are generally characteristic of the organism. Dermatophytes produce conidia. Arthroconidia are produced when hyphae fragment or lyse. They may appear as thickor thin-walled cells and are typically typicall y larger than the hyphae from which they came. The separation occurs at the septae. The mold form of Coccidioides immitis reproduce in such a fashion. Sporangia are sacs or cases that are multicellular structures in which spores are produced. Zygomycetes reproduce in this way. Chlamydoconidia are thick-walled, round conidia that are formed during unpleasant environmental conditions. Trichophyton tonsurans produces these structures. Q/Q(M)-477564 Report a Problem Numerous umbilicated nodules resembling molluscum molluscum contagiosum developed in a patient with recently diagnosed HIV infection. Which of the following fungi might be the causative agent(s)? 1. Candida tropicalis 2. Cryptococcus neoformans 3. Aspergillus fumigatus 4. Histoplasma capsulatum 5. Penicillium marneffei 1

2

2

3

3

2, 4

4

4, 5

5

2, 4, 5

Q/Q(M)-474507 Report a Problem Numerous umbilicated nodules resembling molluscum molluscum contagiosum developed in a patient with recently diagnosed HIV infection. Which of the following fungi might be the causative agent(s)? 1. Candida tropicalis 2. Cryptococcus neoformans 3. Aspergillus fumigatus 4. Histoplasma capsulatum 5. Penicillium marneffei 5

2, 4, 5

All three organisms are seen in AIDS patients and can produce molluscum-like lesions. Q/Q(M)-474507 Report a Problem Which of the following is most likely to be a primary cutaneous infection? 1

North American Blastomycosis 46

2

Histoplasmosis

3

Paracoccidioidomycosis

4

Cryptococcosis

5

Penilliosis

Q/Q(M)-474496 Report a Problem Which of the following is most likely to be a primary cutaneous infection? 1

North American Blastomycosis

All other mycoses are primary pulmonary infections, which may disseminate to the skin. Q/Q(M)-474496 Report a Problem Black granules are found in mycetoma caused all the following organisms except: 1

Madurella grisea

2

M. mycetomatis

3

Exophiala jeanselmei

4

Curvularia

5


Q/Q(M)-474515 Report a Problem Black granules are found in mycetoma caused all the following organisms except: 5


All organisms listed other than S. apiospermum are dematiaceous agents of mycetoma. Q/Q(M)-474515 Report a Problem A patient with a pulmonary infection and cervical adenopathy has vesicles, papules and ulcerations on the oral and nasal mucosa. Tissue culture reveals yeast with multiple buds giving a �mariner �s wheel� appearance. The organism is: 1

Penicillium marneffei

2


3


4

Blastomyces dermatitidis

5

Leishmania mexicana

Q/Q(M)-477202 Report a Problem A patient with a pulmonary infection and cervical adenopathy has vesicles, papules and ulcerations on the oral and nasal mucosa. Tissue culture reveals yeast with multiple buds giving a �mariner �s wheel� appearance. The organism is: 3


Paracoccidioides brasiliensis causes a chronic progressive infection that is most commonly seen in rural areas of South America. Patients may have constitutional symptoms, lung involvement, ulcers of the upper respiratory and digestive tract, and verrucous/ulcerated cutaneous lesions. Classically, Paracoccidioides brasiliensis has a 47

�mariner �s wheel� appearance. Q/Q(M)-477202 Report a Problem Tinea imbricata is most frequently caused by: 1

T. mentagrophytes

2

M. Audouinii

3

T. concentricum

4

E. floccosum

5

M. furfur

Q/Q(M)-474519 Report a Problem Tinea imbricata is most frequently caused by: 3

T. concentricum

Tinea imbricata or Tokelau, an unusual type of tinea corporis causing polycyclic scaly lesions, is endemic in the South Pacific Islands, Far East and C. & S. America. Q/Q(M)-474519 Report a Problem

48

Mycology MCQs

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