MTAP 2 Flashcards
A bulldozer operator became ill while working on a new highway in the San
Joaquin Valley. He developed chest pain, anorexia, headache and general malaise, and myalgia with fever. Chest X-ray showed pneumonic infiltrate and a single, well-defined nodule in the left lower lobe. His leukocyte count and sedimentation rate were slightly elevated. Although no fungus was seen in direct examination of a sputum specimen, processing included a culture on Sabouraud dextrose agar with chloramphenicol and cycloheximide. Within 3 days at 30°C, this culture produced moist, grayish growth, and white aerial mycelia began to develop (see Color Plate 30B). A lactophenol cotton blue wet mount of this organism is seen in Color Plate 31
What is the most likely identification of this fungus?
A. Asperigillus fumigatus
B. Blastomyces dermatitidis
C. Coccidioides immitis
D. Histoplasma capsulatum
C. Coccidioides immitis
A 38-year-old male from Ohio presented to his physician with a mild influenza like illness that included headache and malaise. His chest X-ray showed no infiltrates. His past medical history was unremarkable. He had no history of travel but reported recently cleaning the bell tower at his church, which was littered with bird excrement. The most likely agent causing his disease is
A. Aspergillus fumigatus
B. Coccidioides immitis
C. Candida albicans
D. Histoplasma capsulatum
D. Histoplasma capsulatum
A 44-year-old gardener pricked herself with a rose thorn. A subcutaneous fungal
infection characterized by the development of necrotic ulcers followed this
direct inoculation of fungal spores into the skin. The causative fungus was
cultured as a small yeast form at 35°C (see Color Plate 32 •) and as a mould at room temperature with delicate hyphae and conidia. This disease is
A. Blastomycosis
B. Chromomycosis
C. Mycetoma
D. Sporotrichosis
D. Sporotrichosis
A yeastlike fungus was isolated from a sputum sample. No hyphae were produced on cornmeal agar with Tween 80. The isolate was negative for nitrate assimilation and positive for inositol assimilation and produced urease at 37°C. These findings are typical of
A. Candida krusei
B. Cryptococcus terreus
C. Cryptococcus neoformans
D. Trichospown beigelii
C. Cryptococcus neoformans
A 24-year-old Vietnamese refugee was seen at a clinic in Houston. His chief
complaints were weight loss and fever. A complete blood count confirmed he was suffering from anemia as well. Multiple skin lesions were present on his arms, some of them draining pus. Gram stain of the pus revealed what appeared to be yeastlike cells. A culture of the pus grew a green mould at 22°C, which produced a red soluble pigment (see Color Plate 33). A lactophenol cotton blue wet mount of
this organism is seen in Color Plate 34. The causative agent in this case is
A. Aspergillus fumigatus
B. Fusarium sp.
C. Trichoderma sp.
D. Penicillium marneffei
D. Penicillium marneffei
A section of a lymph node stained with the Gomori silver and hematoxylin and eosin stains is shown in Color Plate 35. A lactophenol cotton blue wet mount of a mould that grew from this specimen is shown in Color Plate 36. Large, one celled, smooth to tuberculate macroconidia and smooth or echinulate microconidia are typical of mycelial phase growth of
A. Blastomyces dermatitidis
B. Coccidioides immitis
C. Histoplasma capsulatum
D. Paracoccidioides brasiliensis
C. Histoplasma capsulatum
Which of the following types of Candida albicans infection is commonly acquired from an exogenous source?
A. Diaper rash
B. Neonatal thrush
C. Perianal infection
D. Urinary tract infection
B. Neonatal thrush
In a direct examination of a KOH wet mount of a nail specimen, Epidermophyton floccosum could be detected as
A. Arthroconidia
B. Blastoconidia
C. Macroconidia
D. Microconidia
A. Arthroconidia
The mould phase of the systemic fungus Blastomyces dermatitidis can be confused with
A. Scedosporium apiospermum
B. Sporothrix schenckii
C. Aspergillus sp.
D. Penicillium notatum
A. Scedosporium apiospermum
It is usually difficult or impossible to identify a fungal culture before it is
mature. However, hyaline, septate hyphae, and a young conidiophore with a foot cell (see Color Plate 37B) and a swollen vesicle are excellent clues to the identification of
A. Acremonium
B. Aspergillus
C. Paecilomyces
D. Penicillium
B. Aspergillus
Zygomycetes are rapidly growing, airborne saprobes. In clinical specimens
they
A. Are common as normal, human microflora
B. Are found only as contaminants
C. May be seen in a dimorphic tissue phase
D. May be found as a cause of rapidly fatal infection
D. May be found as a cause of rapidly fatal infection
Trichophyton rubrum and T. mentagrophytes may be differentiated by the
A. Consistently different appearance of their colonies
B. Endothrix hair infection produced by T. rubrum
C. Fluorescence of hairs infected with T. rubrum
D. In vitro hair penetration by T. mentagrophytes
D. In vitro hair penetration by T. mentagrophytes
Broad, coenocytic hyphae found in tissue would be most typical of infection with
A. Aspergillus
B. Blastomyces
C. Microsporum
D. Rhizopus
D. Rhizopus
A fungus infecting only skin and nails typically produces in culture
A. Spindle-shaped, hyaline, echinulate macroconidia and microconidia
B. Cylindrical or club-shaped, smooth, thin-walled macroconidia and microconidia
C. Many microconidia in clusters or along the hyphae
D. Large, thin-walled, club-shaped macroconidia without microconidia
D. Large, thin-walled, club-shaped macroconidia without microconidia
The most useful finding for prompt, presumptive identification of C. albicans
is its
A. Failure to assimilate sucrose
B. “Feathering” on EMB
C. Production of chlamydospores
D. Production of germ tubes
D. Production of germ tubes
Identify the dimorphic fungus that typically has a tissue phase in which the
large mother cells have one to a dozen narrow-necked buds and a slowly growing
mycelial form with intercalary chlamydoconidia and coiled hyphae.
A. Blastomyces dermatitidis
B. Coccidioides immitis
C. Histoplasma capsulatum
D. Paracoccidioides brasiliensis
D. Paracoccidioides brasiliensis
Which of the following stains greatly enhances the visibility of fungi by binding
to the cell walls, causing the fungi to fluoresce blue-white or apple green?
A. Rhodamine-auramine
B. Warthin-Starry
C. Calcofluor white
D. Periodic acid-Schiff
C. Calcofluor white
The formation of arthroconidia is not an important characteristic in the identification of
A. Coccidioides
B. Geotrichum
C. Trichosporon
D. Sporothrix
D. Sporothrix
A black pigment produced by colonies growing on bird seed agar is due to
A. Urease
B. Phenol oxidase
C. Sucrose assimilation
D. Arthroconidia production
B. Phenol oxidase
Which of the following fungi is not considered an opportunistic pathogen?
A. Absidia
B. Aspergillus
C. Coccidioides
D. Fusarium
C. Coccidioides
Observation of hyaline or dematiaceous hyphae is an early clue in the identification of common, airborne fungi. Which of the following genera contains species found as dematiaceous contaminants?
A. Alternaria
B. Aspergillus
C. Fusarium
D. Penicillium
A. Alternaria
Which of the following fungi is most likely to be found as a common saprobe
and as an agent of keratitis?
A. Exophiala
B. Phialophora
C. Fusarium
D. Wamgiella
C. Fusarium
The microscopic identification of Pneumocystis jirovecii is based on the
detection of
A. Arthroconidia in subcutaneous tissue biopsies
B. Cysts and trophozoites in respiratory specimens
C. Yeasts in respiratory specimens
D. Tuberculate macroconidia in lung biopsies
B. Cysts and trophozoites in respiratory specimens
Fungi that undergo asexual reproduction
are termed
A. Imperfect
B. Perfect
C. Aseptate
D. Septate
A. Imperfect
Hyaline septate hyphae, branched or unbranched conidiophores, and
multicelled banana-shaped conidia are characteristic of which of the following?
A. Fusarium
B. Curvularia
C. Acremonium
D. Trichophyton
A. Fusarium
Which of the following does not correctly describe the yeast Rhodotorula rubra?
A. It has been isolated from dairy products, soil, and water.
B. It is the most common fungal cause of diaper rash.
C. It has been identified as a nosocomial pathogen.
D. It has been found as a contaminant or commensal in specimens of urine,
sputum, and feces.
B. It is the most common fungal cause of diaper rash.
A 21-year-old male member of a university track team presents to student health services with a light brown circular lesion on his upper back. The agent most likely responsible for this condition is
A. Candida albicans
B. Fusarium spp.
C. Geotrichum candidum
D. Malassezia furfur
D. Malassezia furfur
Which of the following is likely to be found in clinical specimens as normal microflora and as clinically significant isolates?
A. Aspergillus niger
B. Paracoccidioides brasiliensis
C. Penicillium marneffei
D. Candida albicans
D. Candida albicans
A 4-year-old child’s hair is falling out in patches. The hair fluoresces when subjected to the UV light from a Wood’s lamp. When the hair is cultured, a white cottony mould grows at 25°C on potato dextrose agar. Microscopically, rare microconidia, septate hyphae, and terminal chlamydospores are seen. Macroconidia are absent. The mould fails to grow on polished rice grains. The causative agent is
A. Microsporum audouinii
B. Microsporum gypseum
C. Trichophyton mentagrophytes
D. Trichophyton rubrum
A. Microsporum audouinii
In tissues infected with Histoplasma capsulatum
A. The hyphae usually invade blood vessels
B. Encapsulated yeast cells are typical
C. Tuberculate macroconidia are typical
D. The fungus is usually intracellular
D. The fungus is usually intracellular
For each numbered mycosis below, choose the letter of the environment most commonly associated with an increased incidence of that infection.
- Blastomycosis
- Coccidioidomycosis
- Cryptococcosis
A. Lower Sonoran Life Zone
B. Mississippi and Ohio River basins
C. Pigeon roosts
D. Bat roosts
- Blastomycosis - B. Mississippi and Ohio River basins
- Coccidioidomycosis - A. Lower Sonoran Life Zone
- Cryptococcosis - C. Pigeon roosts
For each numbered mycosis below, choose the letter of the environment most commonly associated with an increased incidence of that infection.
- Histoplasmosis
- Sporotrichosis
A. Sphagnum moss
B. Starling roosts
C. Stagnant fresh water
D. Colorado River Valley
- Histoplasmosis - B. Starling roosts
35. Sporotrichosis - A. Sphagnum moss
For each numbered incomplete statement, select the letter of the most appropriate
species.
- The cause of white piedra
- The cause of black piedra
- The cause of tinea nigra
A. Hortaea werneckii
B. Trichosporon sp.
C. Piedraia hortae
D. Fonsecaea compacta
- The cause of white piedra - B. Trichosporon sp.
- The cause of black piedra - C. Piedraia hortae
- The cause of tinea nigra - A. Hortaea werneckii
For each numbered incomplete statement, select the letter of the most appropriate
species.
- The cause of tinea versicolor
- A keratinophilic saprophyte
41 A cause of otomycosis
A. Aspergillus niger
B. Malassesia furfur
C. Microsporum gypseum
D. Geotrichum Candid
- The cause of tinea versicolor - B. Malassesia furfur
- A keratinophilic saprophyte - C. Microsporum gypseum
41 A cause of otomycosis - A. Aspergillus niger