Mycology Exam Flashcards
This type of hyphae are not pigmented
a. Demitaceous
b. Hyaline
c. Phaeoid
d. Mycelia
b. Hyaline
This fungi is associated with tinea versicolor and requires lipids for growth
a. Coccidiodes immitis
b. Blastomyces dermatitidis
c. Sporothrix schenckii
d. Malassezia furfur
d. Malassezia furfur
Which fungi is most associated with decaying wood and leaves, primary lung disease, and large, broad based yeasts?
a. Histoplasma capsulaturm
b. Blastomyces dermatitidis
c. Coccidioides immitis
d. Paracoccidioides brasiliensis
b. Blastomyces dermatitidis
Match the fungal differential agar on the left with it’s use on the right:
POTATO DEXTROSE AGAR (PDA)
a. promotes sporulation and pigmentation of colonies
b. Enhances chlamydospores production for Candida spp.
c. C. neoformans will produce black to brown colonies due to the activity of phenol oxidase
a. promotes sporulation and pigmentation of colonies
Match the fungal differential agar on the left with it’s use on the right:
BIRD SEED AGAR
a. promotes sporulation and pigmentation of colonies
b. Enhances chlamydospores production for Candida spp.
c. C. neoformans will produce black to brown colonies due to the activity of phenol oxidase
c. C. neoformans will produce black to brown colonies due to the activity of phenol oxidase
Match the fungal differential agar on the left with it’s use on the right:
CORNMEAL w/TWEEN 80
a. promotes sporulation and pigmentation of colonies
b. Enhances chlamydospores production for Candida spp.
c. C. neoformans will produce black to brown colonies due to the activity of phenol oxidase
b. Enhances chlamydospores production for Candida spp.
A 45-year old pigeon breeder, who is on immunosuppressive steroids complained to his physician of headache, dizziness, blurred vision and a stiff neck. Specimens of purulent CSF were sent to your microbiology laboratory. Gram stain of the CSF was reported as negative, however on brain heart infusion agar with blood, a white, mucoid yeast grew rapidly.
What test(s) will you use to identify this organism? (select all that applies)
a. rapid urea
b. phenyl oxidase production on bird seed agar
c. wood’s lamp fluorescence
d. cornmeal agar morphology
a. rapid urea
b. phenyl oxidase production on bird seed agar
All of the following are dimorphic fungi except
a. Histoplasma capsulatum
b. Blastomyces dermatitidis
c. Coccidiodes spp
d. Aspergillus niger
d. Aspergillus niger
Which fungus is most often acquired by traumatic implantation into the skin?
a. Histoplasma capsulatum
b. Sporothrix schenkii
c. Coccidiodes ssp
d. Talaromyces marneffei
b. Sporothrix schenkii
Sickle- or boat- shaped macroconidia on potato dextrose agar are characteristic of
a. Alternaria spp
b. Aspergillus spp
c. Penicillium spp
d. Fusarium spp
d. Fusarium spp
Microsporum infections involve:
a. Hair, skin, and nails
b. Hair and skin
c. Skin and nails
d. none of the above
b. Hair and skin
Which of the following is a fungus known to cause chromoblastomycosis?
a. Curvularia
b. Acremonium spp
c. Madurella spp
d. Fonsecaea spp
d. Fonsecaea spp
A 65-year-old male with HIV presents to the emergency department with night sweats, a non productive cough, and a low grade fever. PCP is suspected. Which of the following is the best specimen for diagnostic staining for P. jirovecii?
a. Urine
b. Sputum
c. Bronchial alveolar large fluid (BAL)
d. Blood
e. Nasopharyngeal swab
c. Bronchial alveolar large fluid (BAL)
Match each description with the correct organism
CANDIDA ALBICANS
a. Phenoloxidase positive
b. Develops germ tubes
c. Causes white piedra
d. Causes tinea versicolor
b. Develops germ tubes
Match each description with the correct organism
CRYPTOCOCCUS SPP
a. Phenoloxidase positive
b. Develops germ tubes
c. Causes white piedra
d. Causes tinea versicolor
a. Phenoloxidase positive
Match each description with the correct organism
TRICHOSPORON SPP
a. Phenoloxidase positive
b. Develops germ tubes
c. Causes white piedra
d. Causes tinea versicolor
c. Causes white piedra
Match each description with the correct organism
MALASSEZIA SPP
a. Phenoloxidase positive
b. Develops germ tubes
c. Causes white piedra
d. Causes tinea versicolor
d. Causes tinea versicolor
A spinal fluid (CSF) specimen arrives in the lab with an order for fungal culture.
Select the best media to set up this specimen (Select all that apply)
a. Sabouraud dextrose with brain-heart infusion agar (SABHI)
b. Dermatophyte Test Medium (DTM)
c. Brain-Heart Infusion Agar w/ blood (BHIB)
d. Cornmeal Agar with Tween 80
a. Sabouraud dextrose with brain-heart infusion agar (SABHI)
c. Brain-Heart Infusion Agar w/ blood (BHIB)
Routine fungal cultures are incubated:
a. at 37C in a CO2 incubator
b. at 42C in a humid environment
c. at 4C
d. at 30C in a humid environment
d. at 30C in a humid environment
A 60 year-old chicken farmer from Florida presented with fever, cough and fatigue and a lesion on his arm. Direct examination of biopsy tissue from the arm revealed abundant small yeast like cells and the cultures grew the fungus shown below.
What is the most likely identification of this fungus?
a. Histoplasma capsulatum
b. Blastomyces dermatitidis
c. Coccidiodes immitis
d. Sporothrix schenkii
a. Histoplasma capsulatum
A 64-year-old male presented with an ulcerating lesion on the leg. He remembered receiving a penetrating injury by a thorn from an African Acacia tree some 9 months earlier. A biopsy showed the presence of fungal elements and the culture grew the fungus shown below
What is the most likely identification of this fungus?
a. Histoplasma capsulatum
b. Blastomyces dermatitidis
c. Coccidiodes immitis
d. Sporothrix schenkii
d. Sporothrix schenkii
A 35-year-old retired painter with chronic myeloid leukemia developed a necrotizing pneumonia with a bronchopleural fistula. Lobectomy showed the presence of filamentous hyphae and the culture below was isolated.
a. Aspergillus niger
b. Mucor spp
c. Aspergillus fumigatus
d. Acremonium spp
c. Aspergillus fumigatus
A 35-year old male mountain bike rider presented with vesicular scaly lesions with a serous exudate on the sole of his foot. Nail scrapings were taken. KOH microscopy was negative, however the culture seen below was isolated.
What is the most likely identification of this fungus?
a. Microsporum gypseum
b. Trichophyton rubrum
c. Microsporum audouinii
d. Trichophyton mentagrophtes
d. Trichophyton mentagrophtes
A 68 year-old New England man was admitted to the hospital for refractory pneumonia. Despite the initiation of triple antibiotic therapy, he continued to spike fevers and his respiratory status progressively declined. Notably, the patient reported recent travel to Arizona. Fungal cultures from a sputum specimen isolated the fungus in the images below:
What is the most likely identification of this fungus?
a. Coccidiodes immitis
b. Blastomyces dermatitidis
c. Histoplasma capsulatum
d. Aspergillus fumigatus
a. Coccidiodes immitis
What antibiotic is used in growth media to help isolate dermatophytes?
a. Fluconazole
b. Penicillin
c. Cyclohexamide
d. Aminoglycoside
c. Cyclohexamide
What is the characteristic appearance of the microconidia and hyphae of Trichophyton rubrum on lactophenol cotton blue preparations?
a. Club-shaped
b. Broad-based budding
c. Birds on a telephone wire
d. Mariner’s wheel
c. Birds on a telephone wire
Which supplement is necessary to add to culture media to ensure proper growth of Malassezia species?
a. Short chain fatty acid
b. Olive oil
c. KOH
d. Catalase
b. Olive oil
Which Candida spp. is the most commonly encountered human pathogen?
a. Candida glabrata
b. Candida tropicalis
c. Candida albicans
d. Candida krusei
c. Candida albicans
If zygomycosis is clinically suspected, how should a tissue specimen be prepared for culture?
a. The specimen should be blended
b. The specimen should be grinded
c.The specimen should be frozen
d. The specimen should be minced
d. The specimen should be minced
What are the typical colony colors of Aspergillus fumigatus?
a. Yellow-red
b. Blue-green
c. Yellow-green
d. Orange-brown
b. Blue-green
A Zygomycete with no rhizoid. The sporangia are spherical and tend to fall apart, releasing numerous spores.
a. Rhizopus spp
b. Rhizomucor spp.
c. Sycephalastrum spp
d. Mucor spp.
d. Mucor spp.
What is the characteristic budding morphology that can help identify Blastomyces spp.?
a. Narrow-based budding
b. Broad- based budding
c. Circumferential budding
d. Radial budding
b. Broad- based budding
This organism is considered high-risk to laboratory personnel. Extreme care must be taken with this organism and all manipulations must use BSL-3 work practices.
a. Candida albicans
b. Coccidiodes spp
c. Aspergillus spp
d. Cryptococcus spp
b. Coccidiodes spp
This organism produces large, round yeast cells with circumferential budding that gives the appearance of a ‘mariner’s wheel’
a. Paracoccidiodes brasiliensis
b. Coccidioides immitis
c. Candida albicans
d. Histoplasma capsulatum
a. Paracoccidiodes brasiliensis
What is the most helpful feature in differentiating the Zygomycetes from the other hyaline molds in the clinical mycology laboratory?
a. the production of rhizoids
b. the production of spores within sporangia
c. the formation of septate hyphae
d. the formation of germ tubes
b. the production of spores within sporangia
The curved, multi-celled, dark brow staining macroconidia divided by transverse septa that can be observed in this image is characteristic of which of the following species of dematiaceous fungi?
a. Bipolaris spp.
b. Stemphylium spp.
c. Curvularia spp.
d. Alternaria spp.
c. Curvularia spp.
The yeast seen below was isolated in a sputum culture. Based on what is seen in this image, what is the presumptive identification?
a. Cryptococcus neoformans
b. Candida albicans
c. Candida glabrata
d. Candida kefyr
b. Candida albicans
All of the following observations are consistent with the laboratory identification of Cryptococcus neoformans EXCEPT:
a. colonies that appear mucoid on primary isolation culture medium
b. negative urease test
c.presence of capsular material
d. tan-brown pigment on bird seed agar
b. negative urease test
The formation of germ tubes when fetal bovine serum is inoculated with the yeast isolate leads to the presumptive identification of which of the following yeasts?
a. Candida glabrata
b. Candida parapsilosis
c. Candida albicans
d. Cryptococcus neoformans
c. Candida albicans
Which of the following dimorphic molds produces spherical or oval conidia, each supported by and individual conidiophore (‘lollipop’) as represented in this imate?
a. Blastomyces dermatitidis
b. Coccidiodes immitis
c. Histoplasma capsulatum
d. Sporthrix schenckii
a. Blastomyces dermatitidis
Interpret this germ tube result:
a. Germ tube: postive
b. Germ tube: negative
b. Germ tube: negative
Match the mycosis with the etiological agent:
Sporotrichosis
a. Alternaria spp.
b. Sporothrix schenckii
c. Fonsecaea pedrosi
d. Pseudoallscheria boydii
b. Sporothrix schenckii
Match the mycosis with the etiological agent:
Chromoblastomycosis
a. Alternaria spp.
b. Sporothrix schenckii
c. Fonsecaea pedrosi
d. Pseudoallscheria boydii
c. Fonsecaea pedrosi
Match the mycosis with the etiological agent:
Phaeohyphomycosis
a. Alternaria spp.
b. Sporothrix schenckii
c. Fonsecaea pedrosi
d. Pseudoallscheria boydii
a. Alternaria spp.
Match the mycosis with the etiological agent:
Mycetoma
a. Alternaria spp.
b. Sporothrix schenckii
c. Fonsecaea pedrosi
d. Pseudoallscheria boydii
d. Pseudoallscheria boydii
Which of the following fungal infections is endemic in the southwestern United States desert regions and has now been found in southeast Washington?
a. Histoplasmosis
b. Blastomycosis
c. Coccidiomycosis
d. Sportrichosis
c. Coccidiomycosis
All of the following are examples of appropriate specimens for the recovery of fungi except:
a. Tissue biopsy
b. Cerebrospinal fluid
c. Aspirate of exudate
d. Swab
d. swab
Dimorphic molds are found in infected tissue in which form?
a. Mold phase
b. Yeast phase
c. Encapsulated
d. Latent
b. Yeast phase
A mold that produces colonies with a dark brown, green-black, or black appearance of both the surface and reverse side is classified as:
a. Dematiaceous mold
b. Dermatophyte
c. Hyaline mold
d. Dimorphic fungus
a. Dematiaceous mold
A hyaline mold was recovered from a patient with AIDS. It produced rose colored colonies on SabDex agar. Microscopic examination showed what is seen in the image below:
What is the most likely identification?
a. Fusarium spp
b. Wangiella spp
c. Exophiala spp
d. Phialophora spp
a. Fusarium spp
The fungus in the image(s) below was isolated from a pulmonary nodule specimen. What is the most likely identification?
a. Aspergillus spp
b. Paecilomyces spp
c. Penicillium spp
d. Chrysosporium spp
b. Paecilomyces spp
A 2-month old infant in good health was scheduled for a checkup at the pediatrician’s office. After arriving for the appointment, the mother noted white patches on the baby’s tongue and in his mouth. The baby constantly used a pacifier.
What is the most likely organism causing the white patches?
a. Cryptococcus neoformans
b. Candida albicans
c. Aspergillus fumigatus
d. Coccidiodes immitis
b. Candida albicans
A 79-year old female nursing home patient was admitted to the hospital with a fever and central nervous system dysfunction. Routine blood work and blood cultures were ordered. After 48 hours the blood cultures revealed a budding yeast. The following tests performed from Sabouraud dextrose agar after 3 days showed:
Germ Tube = Negative
Urease = Positive
Birdseed agar = Brown
Pseudohyphae = negative
Blastospores = positive
chlamydospores = negative
What is the most likely identification?
a. Candida albicans
b. Candida tropicalis
c. Cryptococcus neoformans
d. Coccidiodes immitis
c. Cryptococcus neoformans
What is the first step to be performed in the identification of an unknown yeast isolate?
a. Gram stain smear
b. India ink stain
c. Catalase test
d. Germ tube test
a. Gram stain smear
For which clinical specimen is the KOH direct mount technique fore examination of fungal elements used?
a. Skin
b. CSF
c. Blood
d. Bone marrow
a. Skin
Which practices must be used to safely work with fungal cultures?
a. Seal plates closed
b. Work in a BSC when opening plates
c. Wear gloves
d. All of the above
d. All of the above
