Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiology > 8.9 > Flashcards

8.9 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

All of the following are examples of appropriate specimens for the recovery of fungi except:
A. Tissue biopsy
B. CSF
C. Aspirate of exudate
D. Swab

A

D. Swab

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

For which clinical specimens is the KOH direct mount technique for examination of fungal elements used?
A. Skin
B. CSF
C. Blood
D. Bone marrow

A

A. Skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The India ink stain is used as a presumptive test for the presence of which organism?
A. Aspergillus niger in blood
B. Cryptococcus neoformans in CSF
C. Histoplasma capsulatum in CSF
D. Candida albicans in blood or body fluids

A

B. Cryptococcus neoformans in CSF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Cutaneous disease involving skin, hair, and nails usually indicates an infection with a:
A. Dimorphic fungus
B. Dermatophyte
C. Zygomycetes
D. Candida species

A

B. Dermatophyte

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

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

D. Germ tube test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

An isolate produced a constriction that was interpreted as a positive germ tube, but Candida albicans was ruled out when confirmatory tests were performed. Which of the following fungi is the most likely identification?
A. Candida tropicalis
B. Cryptococcus neoformans
C. Candida glabrata
D. Rhodotorula rubra

A

A. Candida tropicalis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Cornmeal agar wit Tween 80 is used to identify which characteristic of an unknown yeast isolate?
A. Hyphae (true and pseudo)
B. Blastoconidia and arthroconidia
C. Chlamydospores
D. All of these options

A

D. All of these options

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Blastoconidia are the beginning of which structures?
A. Arthroconidia
B. Germ tubes
C. Pseudohyphae
D. True hyphae

A

C. Pseudohyphae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

An isolate from CSF growing on cornmeal agar produces the following structures:
-Blastoconidia=+
-Chlamydospores=Neg
-Pseudohyphae=Neg
-Arthroconidia=Neg
Which test should be performed next?
A. Birdseed agar and urease
B. Germ tube and glucose
C. India ink and germ tube
D. All of these options

A

A. Birdseed agar and urease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which of the following yeast enzymes is detected using birdseed (niger seed) agar?
A. Phenol oxidase
B. Catalase
C. Urease
D. Nitrate reductase

A

A. Phenol oxidase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

C. neoformans; R. rubra; T. cutaneum; C. albicans
Urease: +, +, +, Neg
Germ tube: Neg, Neg, Neg, +
Brown and black colonies on niger seed agar: +, Neg, Neg, Neg
Which of the following yeast is characteristically positive for germ tube production?
A. Candida tropicalis
B. Candida kefyr (pseudotropicalis)
C. Cryptococcus neoformans
D. Candida albicans

A

D. Candida albicans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Arthroconidia production is used to differentiate which two yeast isolates?
A. Candida albicans and Candida dubliniensis
B. Trichosporon cutaneum and Crytococcus neoformans
C. Candida albicans and Candida tropicalis
D. Saccharomyces cerevisiae and Candida glabrata

A

B. Trichosporon cutaneum and Crytococcus neoformans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The urease test, niger seed agar test, and the germ tube test are all used for the presumptive identification of:
A. Rhodotorula rubra
B. Cryptococcus neoformans
C. Trichosporon cutaneum
D. Candida albicans

A

B. Cryptococcus neoformans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Blastoconidia; Pseudohyphae; Arthroconidia
Crytococcus spp: +, Neg, Neg
Candida spp.: +, +, Neg
Trichosporon spp.: +, +, +
Geotrichum: Neg, +, +
Which of the following yeasts produces only blastoconidia on cornmeal Tween 80 agar?
A. Candida spp.
B. Trichosporon spp.
C. Geotrichum spp.
D. Crytococcus spp.

A

D. Crytococcus spp.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Ascospores are formed by which yeast isolate?
A. Saccharomyces cerevisiae
B. Candida albicans
C. Cryptococcus neoformans
D. All of these options

A

A. Saccharomyces cerevisiae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

A germ tube-negative, pink yeast isolate was recovered form the respiratory secretions and urine of a patient with AIDS. Given the following results, what is the most likely identification?
Cornmeal Tween 80 Agar
-Blastoconidia=+
-Arthroconidia=Neg
-Pseudohyphae=Neg
-Urease=+
A. Candida albicans
B. Rhodotorula spp.
C. Crystococcus spp.
D. Trichosporon spp.

A

B. Rhodotorula spp.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Chlamydospore production is demonstrated by which Candida species?
A. C. glabrata
B. C. krusei
C. C. albicans
D. C. tropicalis

A

C. C. albicans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Carbohydrate assimilation tests are used for the identification of yeast isolates by inoculating media:
A. Free of carbohydrates
B. Free of niger seed
C. Containing carbohydrates
D. Containing yeast extract

A

A. Free of carbohydrates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Yeast recovered form the urine of a catheterized patient receiving chemotherapy for cancer gave the fllowing results:
Cornmeal Tween 80 agar
-Germ tube=+
-Pseudohyphae=+
-Blastoconidia=+
-Arthroconidia=Neg
-Chlamydospores=+
What further testing is necessary?
A. Carbohydrate assimilation and urease
B. Urease and niger seed
C. Nitrate reductase and carbohydrate fermentation
D. No further testing is needed for identification

A

D. No further testing is needed for identification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

A blood agar plate inoculated with sputum from a patient with diabetes mellitus grew very few bacterial flora and predominance of yeast. Given the following results, what is the most likely identification of the yeast isolate?
Cornmeal Tween 80 Agar
-Germ tube=Neg
-Arthroconidia=Neg
-Chlamydospores=Neg
-Pseudohyphae=+
-Blastoconidia=+ (arranged along pseudohyphae)
A. Candida tropicalis
B. Candida kefyr (pseudotropicalis)
C. Trichosporon cutaneum
D. Geotrichum candidum

A

A. Candida tropicalis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Dimorphic mold are found in infected tissue in which form?
A. Mold phase
B. Yeast phase
C. Encapsulated
D. Latent

A

B. Yeast phase

22
Q

The mycelial form of which dimorphic mold produced thick-walled, rectangular, or barrel-shaped alternate arthroconidia?
A. Coccidiodes immitis
B. Sporothrix schenckii
C. Histoplasma capsulatum
D. Blastomyces dermatitidis

A

A. Coccidiodes immitis

23
Q

The yeast form of which dimorphic fungus appears as oval or elongate cigar shapes?
A. Coccidioides immitis
B. Sporothrix schenckii
C. Histoplasma capsulatum
D. Blastomyces dermatitidis

A

B. Sporothrix schenckii

24
Q

The mycelial form of Histoplasma capsulatum seen on agar resembles:
A. Sepedonium spp.
B. Penicillium spp.
C. Sporothrix spp.
D. Coccidiodes spp.

A

A. Sepedonium spp.

25
Q

The yeast form of which dimorphic mold shows a large parent yeast cell surrounded by smaller budding yeast cells?
A. Paracoccidioides brasiliensis
B. Sporothrix schenckii
C. Coccidioides immitis
D. Histoplasma capsulatum

A

A. Paracoccidioides brasiliensis

26
Q

Which group of molds can be ruled out when septate hyphae are observed in a culture?
A. Dematiaceous
B. Zygomycetes
C. Dermatophytes
D. Dimorphic molds

A

B. Zygomycetes

27
Q

Tinea versicolor is a skin infection caused by:
A. Malassezia furfur
B. Trichophyton rubrum
C. Trichophyton schoenleinii
D. Microsporum gypseum

A

A. Malassezia furfur

28
Q

Which of the following structures is invaded by the genus Trichophyton?
A. Hair
B. Nails
C. Skin
D. All of these options

A

D. All of these options

29
Q

An organism cultured from the skin produces colonies displaying a cherry-red color on Sabouraud dextrose agar after 3-4 weeks and teardrop-shaped microconidia along the side of hyphae. The most likely identification is:
A. Trichophyton rubrum
B. Trichophyton tonsurans
C. Trichophyton schoenleinii
D. Trichophyton violaceum

A

A. Trichophyton rubrum

30
Q

Which Mircosporum species causes an epidemic form of tinea capitis in children?
A. Microsporum canis
B. Microsporum audouinii
C. Microsporum gypseum
D. All of these options

A

B. Microsporum audouinii

31
Q

Microscopic examination of a fungus cultured from a patient with athlete’s foot showed large, smooth-walled, club-shaped macroconidia appearing singly or in clusters of two to three from the tips of short conidiophores. The colonies did not produce microconidia. What is the most likely identification?
A. Trichophyton spp.
B. Alternaria spp.
C. Epidermophyton spp.
D. Microsporum spp.

A

C. Epidermophyton spp.

32
Q

Which trichophyton species causes the favus type of tinea capitis seen in the Scandinavian countries and in the Appalachian region of the United States?
A. T. verrucosum
B. T. violaceum
C. T. tonsurans
D. T. schoenleinii

A

D. T. schoenleinii

33
Q

The Hair Baiting Test is used to differentiate whic tow species of Trichophyton that produce red colonies on Sabouraud agar plates?
A. T. mentagrophytes and T. rubrum
B. T. tonsurans and T. schoenleinii
C. T. tonsurans and T. violaceum
D. T. verrucosum and T. rubrum

A

A. T. mentagrophytes and T. rubrum

34
Q

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:
A. Dematiaceous mold
B. Dermatophyte
C. Hyaline mold
D. Dimorphic fungus

A

A. Dematiaceous mold

35
Q

A rapidly growing hyaline mold began as a white colony but soon developed a black “pepper” effect on the agar surface. the older colony produced a black matte, making it resemble a dematiaceous mold. What is the most likely identification?
A. Penicillium notatum
B. Aspergillus niger
C. Paecilomyces spp.
D. Scopulariopsis spp

A

B. Aspergillus niger

36
Q

Which dematiaceous mold forms flask-shaped phialides, each with a flask-shaped collarette?
A. Phialophora spp.
B. Exophiala spp.
C. Wangiella spp.
D. All of these options

A

A. Phialophora spp.

37
Q

Which Aspergillus species, recovered from sputum or bronchial mucus, is the most common cause of pulmonary aspergillosis?
A. A. niger
B. A. flavus
C. A. funigatus
D. All of these options

A

C. A. funigatus

38
Q

A hyaline mold recovered form a patient with AIDS produced rose-colored colonies with lavender centers on Sabouraud dextrose agar. Microscopic examination showed multiseptate macroconidia appearing as sickles or canoes. What is the most likely identification>
A. Fusarium spp.
B. Wangiella spp.
C. Exophiala spp.
D. Phialophora spp.

A

A. Fusarium spp.

39
Q

Material from a fungus-ball infection produced colonies with a green surface on Sabouraud agar in 5 days at 30C. Microscopic examination showed club-shaped vesicles with sporulation only from the top half of the vesicle. This hyaline mold is most probably which Aspergillus spp.?
A. A. niger
B. A. funigatus
C. A. flavus
D. A terreus

A

B. A. funigatus

40
Q

A rapidly growing nonseptate mold produced colonies with a gray surface resembling cotton candy that covered the entire plate. Microscopic examination revealed sporangiophores arising between, not opposite, the rhizoids and producing pear-shaped sporangia. what is the most likely identification?
A. Absidia spp.
B. Penicillium spp.
C. Rhizopus spp.
D. Aspergillus spp.

A

A. Absidia spp.

41
Q

An India ink test was performed on CSF from an HIV-infected male patient. Many encapsulated yeast cells were seen in the centrifuged sample. Further testing revealed a positive urease test and growth of brown colonies on niger-seed agar. The diagnosis of meningitis was caused by which yeast?
A. Candida albicans
B. Cryptococcus neoformans
C. Cryptococcus laurentii
D. Candida tropicalis

A

B. Cryptococcus neoformans

42
Q

A bone marrow sample obtained form an immunocompromised patient revealed small intracellular cells using a Wright’s stain preparation. Growth on Sabouraud-dextrose agar plates of a mold phase at 25C and a yeast phase at 37C designates the organism as dimorphic. The mold phase produced thick, spherical tuberculated macroconidia. What is the most likely identification?
A. Histoplasma capsulatum
B. Sepedonium spp.
C. Sporothrix schenckii
D. Coccidioides immitis

A

A. Histoplasma capsulatum

43
Q

A lung biopsy obtained from an immunocompromised patient showed many “cup-shaped” cysts (gray to black) in a foamy exudate (green background) using Gomori methenamine silver (GMS) stain. the organism cannot be cultured because it does not grow on routine culture media for molds. The patient was routine culture media for molds. The patient was diagnosed with pneumonia that resisted antibiotic treatment. The most likely identification is?
A. Pneumocystis jirovecci (carinii)
B. Histoplasma capsulatum
C. Sporothrix schenckii
D. Scopulariopsis spp.

A

A. Pneumocystis jirovecci (carinii)

44
Q

Upon direct examination of a sputum specimen, several spherules were noted that contained endospores. Growth on Sabouraud-dextrose agar showed aerial mycelial elements. The septate hyphae produced barrel-shaped arthroconidia. What is the most likely identification?
A. Penicillium marneffei
B. Scopulariopsis spp.
C. Cryptococcus neoformans
D. Coccidioides immittis

A

D. Coccidioides immittis

45
Q

A bone marrow specimen was obtained form an immunocompromised patient who tested positive for HIV. The organism grew rapidly at 3 days showing a mold form (at 25C), displaying conidiophores with four to five terminal metulae with each having four to six phialides. The conidia at the end of the phialides were oval and in short chains. They appear as a fan or broom when viewing under 10X and 40X. At 37C, the yeast form grew more slowly, showing conidia that formed hyphal elements breaking at the septa to produce oval arthroconidia. This thermodimorphic mold is most likely:
A. Paecilomyces spp.
B. Penicillium marneffei
C. Rhizomucor spp.
D. Aspergillus fumigatus

A

B. Penicillium marneffei

46
Q

What is the specimen of choice for the initial diagnosis of Pneumocytstis jirovecii (carinii) in an immunocompromised patient, such as someone with AIDS?
A. Induced sputum
B. Open-thorax lung biopsy
C. CSF
D. Urine

A

A. Induced sputum

46
Q

A transplant patient is suspected of having invasive aspergillosis on the basis of clinical and radiological findings. Which specimen is best for the initial identification of aspergillosis by soluble antigen testing?
A. Blood culture
B. Lung biopsy
C. Serum or urine
D. Sputum

A

C. Serum or urine

47
Q

What is the most common cause of mucormycosis infection in humans?
A. Penicillium spp.
B. Candida albicans
C. Scopulariopsis spp.
D. Rhizopus spp.

A

D. Rhizopus spp.

48
Q

A thermally dimorphic fungus shows a filamentous mold form with tuberculate macroconidia at room temperature, and a yeast form above 35C. Which organism best fits this description?
A. Histoplasma capsulatum
B. Paracoccidioides brasiliensis
C. Candida albicans
D. Coccidioides immitis

A

A. Histoplasma capsulatum

49
Q

SITUATION: After a vacation to the Southwestern United States, a midwesterner complained of flulike symptoms with fever, chills, nonproductive cough, and chest pain. Microscopic exam of sputum, cleared with KOH, revealed lard, thick-walled spherules containing endospores. Upon culture, the mold phase sowed septate hyphae and alternating barrel-shaped arthroconidia. Which organism is most likely the cause of this pneumonia?
A. Coccidioides immitis
B. Histoplasma capsulatum
C. Paracoccidioides brasiliensis
D. Penicillium marneffei

A

A. Coccidioides immitis

50
Q

SITUATION: After a vacation to the Southwestern United States, a midwesterner complained of flulike symptoms with fever, chills, nonproductive cough, and chest pain. Microscopic exam of sputum, cleared with KOH, revealed lard, thick-walled spherules containing endospores. Upon culture, the mold phase sowed septate hyphae and alternating barrel-shaped arthroconidia. Which organism is most likely the cause of this pneumonia?
A. Coccidioides immitis
B. Histoplasma capsulatum
C. Paracoccidioides brasiliensis
D. Penicillium marneffei

A

A. Coccidioides immitis

Microbiology (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions