Question 1

MATCHING&#10;Match the organism with its characteristics.&#10;a.Trichosporon spp.&#10;b.Candida albicans&#10;c.Malassezia furfur&#10;d.Cryptococcus neoformans&#10;Polysaccharide capsule

Accepted Answer

Cryptococcus neoformans is known for having a polysaccharide capsule which helps protect it from host defenses.

Answer: A, B, C
 Trichosporon spp., Candida albicans, and Malassezia furfur do not have a polysaccharide capsule as a defining characteristic.

Question 2

MATCHING&#10;Match the organism with its characteristics.&#10;a.Trichosporon spp.&#10;b.Candida albicans&#10;c.Malassezia furfur&#10;d.Cryptococcus neoformans&#10;White piedra

Accepted Answer

White piedra is a fungal infection caused by Trichosporon spp.

Question 3

Tinea versicolor is a skin infection characterized by superficial brownish scaly areas most often on the trunk, arms, or shoulders.Which type of replacement therapy places patients at risk for developing this type of skin infection?

A) Hormone
B) Lipid
C) Saccharide
D) Gene

Accepted Answer

Malassezia furfur causes tinea versicolor, a skin infection that is characterized by superficial brownish scaly areas on light-skinned persons and lighter areas on dark-skinned persons.The lesions occur on the smooth surfaces of the body, specifically, the trunk, arms, shoulders, and face.It has a worldwide distribution.Malassezia furfur is also a cause of disseminated infection in infants and young children and in adults taking lipid replacement therapy.

Question 4

Encapsulated yeast is identified in the cerebrospinal fluid (CSF)of a patient with AIDS.The most likely stain or reagent used to identify this organism is:&#10;A) potassium hydroxide (KOH).&#10;B) calcofluor white.&#10;C) lactophenol cotton blue.&#10;D) India ink.

Accepted Answer

Traditionally, the India ink preparation has been the most widely used method for the rapid detection of Cryptococcus neoformans in clinical specimens.This method delineates the large capsule of C.neoformans, because the ink particles cannot penetrate the capsular polysaccharide material.

Question 5

Determining urease activity and growth on niger seed agar is helpful in determining which type of yeast?&#10;A) Candida albicans&#10;B) Trichosporon&#10;C) Cryptococcus neoformans&#10;D) Malassezia furfur

Accepted Answer

The rapid urease test (Procedure 63-2)is a most useful tool for screening for urease-producing yeast recovered from respiratory secretions and other clinical specimens.An alternative to traditional urease testing is the rapid selective urease test (Procedure 63-3).This method appears to be useful in rapidly detecting C.neoformans.Using these screening tests is helpful to make a presumptive identification of C.neoformans.In instances in which inoculum is limited, the laboratorian must use tests that can be performed and then prepare a subculture so that additional tests can be performed later.Often, inoculating the organism onto the surface of a plate of niger seed agar is just as fast; the results may be obtained during the same day of incubation at 25º C.This is discussed further in this section.

Question 6

A patient with leukemia is diagnosed with a Candida infection after receiving several doses of chemotherapy.The most likely yeast causing the infection is:&#10;A) C. albicans.&#10;B) C. parapsilosis.&#10;C) C. tropicalis.&#10;D) C. metapsilosis.

Accepted Answer

C.tropicalis has been shown to be prevalent in patients with hematologic malignancies, especially those with neutropenia.

Question 7

MATCHING&#10;Match the organism with its characteristics.&#10;a.Trichosporon spp.&#10;b.Candida albicans&#10;c.Malassezia furfur&#10;d.Cryptococcus neoformans&#10;&#34;Spaghetti and meatball&#34; morphologic appearance

Accepted Answer

"Spaghetti and meatball" appearance is commonly seen in Malassezia furfur under microscopy due to the arrangement of its spores.

Question 8

A patient with acquired immunodeficiency syndrome (AIDS)notices skin lesions on his back that have begun to ulcerate.Upon physical examination, his physician also notices hepatomegaly that is most likely caused by hepatitis.The physician prescribes antifungal therapy to prevent the dissemination of which of the following yeasts?

A) Candida albicans
B) C. neoformans
C) C. glabrata
D) C. tropicalis

Accepted Answer

In the patient who is immunocompromised, disseminated disease with meningitis caused by C.neoformans is common.Disseminated cryptococcosis and cryptococcal meningitis became well recognized in patients with AIDS, and both infections remain important causes of morbidity and mortality in patients in resource-poor countries who do not have access to highly active antiretroviral therapy (HAART).Patients with disseminated infection may exhibit painless papular skin lesions that may ulcerate.Other less common manifestations of cryptococcosis include endocarditis, hepatitis, renal infection, and pleural effusion.

Question 9

The most commonly isolated yeast in clinical specimens is:&#10;A) Candida albicans.&#10;B) C. tropicalis.&#10;C) C. dubliniensis.&#10;D) C. krusei.

Accepted Answer

Candida infections are caused by a variety of species.Although C.albicans is the most commonly isolated yeast, other species are emerging such as C.glabrata, C.parapsilosis, C.tropicalis, C.dubliniensis, and C.krusei.The frequency with which these are isolated varies by institution.Until recently, C.albicans was the most common yeast isolated from infections, constituting at least 60% to 70% of the infections.In the last decade, epidemiologic data reveal a paradigm shift in Candida infections.Studies in the intensive care environment are now confirming an increase of C.glabrata and C.krusei isolated in approximately 25% of the infections and C.albicans in approximately 50% of the infections.

Question 10

If cornmeal agar is set up and chlamydoconidia are produced, the organism is most likely:&#10;A) C. krusei.&#10;B) C. glabrata.&#10;C) C. albicans.&#10;D) C. tropicalis.

Accepted Answer

Cornmeal agar may be successfully used for the detection of characteristic chlamydoconidia produced by C.albicans.This method is currently satisfactory for the definitive identification of C.albicans when the germ-tube test is negative.

Question 11

A patient with diabetes is experiencing creamy patches on his tongue and mucous membranes.Cultures are performed, and yeast is recovered.His diagnosis is most likely:&#10;A) paronychia.&#10;B) onychomycosis.&#10;C) candidemia.&#10;D) thrush.

Accepted Answer

The answer of A patient with diabetes is experiencing creamy...

Question 12

In general, yeast reproduce asexually by the formation of:&#10;A) ascospores.&#10;B) basidiospores.&#10;C) blastoconidia.&#10;D) arthroconidia.

Accepted Answer

The answer of In general, yeast reproduce asexually by the...

Question 13

MATCHING&#10;Match the organism with its characteristics.&#10;a.Trichosporon spp.&#10;b.Candida albicans&#10;c.Malassezia furfur&#10;d.Cryptococcus neoformans&#10;Creamy, white patches

Accepted Answer

The answer of MATCHING&#10;Match the organism with its characteristics.&#10;a.Trichosporon spp.&#10;b.Candida...

Question 14

Blood cultures are drawn on a patient suspected of having a fungemia.Positive cultures reveal the presence of chlamydoconidia on cornmeal agar.In addition, the yeast is germ-tube positive.The most likely identification of the fungal agent is:

A) C. glabrata.
B) C. tropicalis.
C) Cryptococcus neoformans.
D) C. albicans.

Accepted Answer

The answer of Blood cultures are drawn on a patient...

Question 15

Agar medium overlaid with olive oil will enhance the growth of which organism?&#10;A) Malassezia&#10;B) Candida&#10;C) Trichosporon&#10;D) Cryptococcus

Accepted Answer

The answer of Agar medium overlaid with olive oil will...

Question 16

A fungal infection found mostly in the tropics and temperate regions is characterized by the development of soft, yellow or pale-brown aggregations around hair shafts in the axillary, facial, genital, and scalp regions.The fungus that would most likely be isolated is:

A) Candida.
B) Malassezia.
C) Cryptococcus.
D) Trichosporon.

Accepted Answer

The answer of A fungal infection found mostly in the...

Question 17

Cryptococcus neoformans is widely distributed in nature, and aerosolization is a prerequisite to most infections.This organism is most often associated with exposure to:&#10;A) contaminated soil.&#10;B) pigeon excreta.&#10;C) contaminated food.&#10;D) rat excreta.

Accepted Answer

The answer of Cryptococcus neoformans is widely distributed in nature,...

Question 18

Which yeast identification system uses chromogenic substrates to assess specific enzyme activity usually detected within 4 hours?&#10;A) Vitek&#10;B) MicroScan&#10;C) API-20C AUX&#10;D) Uni-Yeast-Tek

Accepted Answer

The answer of Which yeast identification system uses chromogenic substrates...

Deck 62: The Yeasts