Unit 3 Topics Flashcards
Agent of Spelunker’s disease and Darling disease.
Histoplasma capsulatum
The demonstration of encapsulated yeast cells in India ink from a CSF specimen is diagnostic for meningitis caused by…
Cryptococcus neoformans
Fungal cultures are routinely incubated at
25 – 30 oC
A scalp infection that penetrates deep into the hair shaft is referred to as an
endothrix infection
Oral thrush in AIDS patients is usually caused by which yeast?
Candida albicans
The following culture media are used to demonstrate spore formation, EXCEPT…
- potato dextrose agar
- rice medium
- cornmeal agar
- none of the choices
rice medium
The male:female ratio of disseminated form of coccidioidomycosis is
9:1
Coccidioidomycosis is acquired through
inhalation of arthrospores
The most frequently encountered opportunistic fungal agent.
Candida albicans
Which of the following statements is NOT TRUE about agents of endemic mycoses?
- all are dimorphic fungi
- all are agents of systemic disease
- usually acquired by
- inhalation of infective spores
- does not illicit an immune response
does not illicit an immune response
The following are dimorphic fungi, EXCEPT…
- Blastomyces dermatitidis
- Rhizopus spp.
- Sporothrix schenckii
- Histoplasma capsulatum
Rhizopus spp.
What is the gold standard method for identifying yeasts such as Candida in the laboratory?
carbohydrate assimilation test
White Piedra is caused by
Trichosporon beigelii
A carcinogenic hepatotoxin produced by
Aflatoxin
The germ tube test is performed to either confirm or rule out…
Candida albicans
Which of the following media can be used to differentiate Candida albicans from other yeast species?
chlamydospore agar
Subcutaneous fungal infection characterized by the presence of granules in the pus of tumor-like lesions.
eumycotic mycetoma
What tests for the diagnosis of Cryptococcal meningitis may be performed on either CSF or serum?
Ag detection (latex agglutination) test
Which of the following statements is true about Aspergillus species?
normally found in soil
Which of the following is the correct sequence of steps in the laboratory diagnosis of fungal infections?
*direct microscopy – culture - biochem testing – microscopic exam
- culture – microscopic exam of culture – biochem testing – direct microscopy
- direct microscopy – culture – microscopic exam – biochem testing
- biochem testing – microscopic exam – culture – direct microscopy
direct microscopy – culture – microscopic exam – biochem testing
Large budding yeasts described as “mariner’s wheel” or “mickey mouse cap” demonstrated from a sputum specimen is consistent with an infection caused by…
Paracoccidioides brasiliensis
Agent of San Joaquin Valley fever.
Coccidioides immitis
Hyaline septate hyphae were seen in a direct microscopic examination of a tissue sample from an AIDS patient. Upon culture, the mold colonies demonstrated sickle-shaped septate conidia as shown below. Which of the following organisms is the most likely agent?
Fusarium solani
An organism found in caves due to its affinity to soil with high contents of nitrogen from bird and bat guano.
Histoplasma capsulatum
Sclerotic bodies seen in a biopsy are pathognomonic for…
Chromoblastomycosis
M. canis can be differentiated from M. audouinii by its ability to grow on…
Rice medium
Infection of the scalp characterized by yellowish cup-shaped crusts forming honeycomb-like masses.
tinea favosa
Which of the following infections is acquired through skin injuries?
- coccidioidomycosis
- aspergillosis
- sporotrichosis
- blastomycosis
sporotrichosis
Organisms that are said to be adapted exclusively to living on human hosts are called…
Anthropophilic
An organism acquired by inhaling arthroconidia and diagnosed through the demonstration of spherules from a respiratory specimen.
Coccidioides immitis
stains is used primarily for examining fungal cultures?
lactophenol cotton blue
used to be classified as a protozoan?
Pneumocystis jiroveci
what matches the correct site for the following infections
- Tinea Unguium
- Tinea Pedis
- Tinea Imbricata
- Tinea Favosa
nails
feet
body
head
This organism is associated with infections resulting from inhalation of infective conidia from decaying wood and soil.
Blastomyces dermatitidis
Which of the following is not true about tinea favosa?
- It is a type of dermatophyte infection
- It is a form of tinea corporis
- It demonstrates yellow cup-shaped crusts
- none of the choices
It is a form of tinea corporis
A positive result in this test is considered adequate for the identification of a yeast isolate as Candida albicans.
chlamydospores on cornmeal agar
Rhizopus, Mucor, and Absidia species are etiologic agents of…
Zygomycosis
The following are used for direct microscopic examination of fungi from biopsy specimens, EXCEPT…
- KOH with Methylene Blue
- Masson-Fontana
- Periodic Acid Schiff
- Methenamine-Silver stain
KOH with Methylene Blue
only produce surface erosions in the hair penetration test?
T. rubrum
Ringworms are skin infections that demonstrate ring like patches of scaling and erythema. These infections are also known as…
dermatophytoses
positive result for the 5-day urease test?
T. mentagrophytes
Also known as “barber’s itch”.
tinea barbae
This fungus demonstrates trophozoite and cyst stages.
Pneumocystis jiroveci
Olive oil overlayed on the inoculated medium is a technique for the isolation of…
Malassezia furfur
This dermatophyte demonstrate colonies that produce a red pigment and macroconidia described as “pencil-shaped.”
Trichophyton rubrum
Small yeast cells in significant numbers within monocytes and macrophages from a sputum sample is consistent with…
Histoplasma capsulatum
Cycloheximide is added to fungal culture media to inhibit contamination due to…
saprophytic molds
A patient with a nail infection submitted a specimen for culture. Direct microscopic exam revealed septate hyaline hyphae. Microscopic study of the culture demonstrated hyphae and these macroconidia. No microconidia were seen. The organism is most likely:
Epidermophyton floccosum
Filipinos and African Americans run the highest risk of developing the disseminated form of this disease.
Coccidioidomycosis
Cryptococcus neoformans can easily be differentiated from Candida by a…
positive urease test
What matches the following?
- beaver’s tail macroconidia in culture
- septate hyphae and yeasts in skin scrapings
- spiral hyphae
- tuberculate, spindle-shaped macroconidia with 3-15 cells
- hyaline arthroconidia in culture
Epidermophyton floccosum
Malassezia Furfur
Trichophyton Mentagrophytes
Microsporum Canis
Trichosporon beigelli
Conidiospores are produced…
asexually
techniques best maintain the microscopic morphology of fungal hyphae and fruiting structures?
microslide culture
what matches the following:
- tinea manuum
- tinea cruris
- tinea corporis
- tinea barbae
Hand
groin
body
beard
Agent of South American blastomycosis or Lutz-Splendore-Almeida disease.
Paracoccidioides brasiliensis
An infection characterized by the presence of soft, white nodules on hair shafts.
white piedra
what organisms is known to produce chlamydospores?
Candida albicans
Black-dot ringworm is an example of an…
endothrix infection
Often mistaken for melanomas, this infection is characterized by brown to black non-scaly macules that occur often on the palms and soles.
tinea nigra
what organism matches the following:
- cigar shaped yeast cells in direct microscopic exam
- barrel shaped alternating arthroconidia in culture
- shield cells in culture of mold form
- tuberculate spherical macroconidia in culture of mold form
- brush-like conidiophores in culture of mold form
Sporothrix Shenckii
Coccidiodes immitis
Chladophialophora carionii
Histoplasma Capsulatum
Talaromyces marneffei
The causative agent of “gardener’s disease” or “rose handler’s disease”.
Sporothrix schenckii
Trichophyton schoenleinii and T. violaceum are the etiologic agents of…
tinea favosa
What diagnoses will be consistent with finding “copper bodies” in biopsy samples?
chromoblastomycosis
Tinea nigra is caused by…
Hortaea werneckii
Dermatophytoses are caused by members of the following genera, EXCEPT…
- Trichosporon
- Trichophyton
- Epidermophyton
- Microsporum
Trichosporon
Tinea versicolor is caused by…
Malassezia furfur
what is the etiologic agent of tinea imbricata?
Trichophyton concentricum
What is the most probable organism present when a sputum sample exhibits broad-based budding yeasts upon direct examination?
Blastomyces dermatitidis
Hortaea werneckii and Piedraia hortae are agents of…
superficial mycoses
Chlamydospores found at the side of a hyphal segment is called…
sessile
An isolate obtained from a hair sample demonstrated hyphae with very thick septations resembling bamboo rods. Which of the following is most consistent with this finding?
Microsporum ferrugineum
brush-like conidiophores known as penicillus when grown at 25C?
Talaromyces marneffei
what matches the infection with the specimen for direct microscopy
- Tinea versicolor
- Coccidiodes immitis
- cryptcoccosis
- eumycotic mycetoma
skin scarping
sputum
CSF
granules
Samples collected from a case of tinea barbae revealed the following fungal structures in culture: Which of the following is the most probable organism?
Microsporum gypseum
what organism matches the structures
- broad-based budding yeasts in direct microscopic exam
- flowerette or rosette microconidia in culture of mold form
- multiple budding yeasts in direct microscopic exam
- trophozoites and cysts in direct microscopic exam
- pseudohyphae in direct microscopic exam
Blastomyces dermatitidis
sporothrix schenckii
Paracoccidioides Brasiliensis
Pneumocystis jiroveci
Candida Albicans
“Mocassin foot” is a form of…
tinea pedis
Direct examination of a lung biopsy revealed septate hyphae while culture produced molds with the structure shown below. Which of following would be consistent with the findings?
aspergilloma
