8. Clinically Significant Yeasts

Question 1

Causative agent of thrush

Answer 1

Candida spp.

Question 2

Indicator of immunosuppression

Answer 2

Thrush

Question 3

Most common cause of yeast infection

Answer 3

Candida albicans

Question 4

Germ tube result of Candida albicans

Answer 4

Germ tube positive

Question 5

Sucrose reaction of C. albicans

Answer 5

Sucrose positive

Question 6

Candida spp. that is sucrose negative

Answer 6

C. stellatoidea

Question 7

Second most common Candida spp.

Answer 7

C. tropicalis

Question 8

Macroscopic: creamy, glabrous, with mycelial fringe colonies

Answer 8

C. tropicalis

Question 9

Major cause of nosocomial infections; in indwelling catheters

Answer 9

Candida parapsilosis

Question 10

Rarely isolated as a cause of endocarditis and vaginitis

Answer 10

C. krusei

Question 11

Microscopic: pseudohyphae and elongated blastoconidia, branch-like trees

Answer 11

C. krusei

Question 12

Most commonly found as fungemia

Answer 12

Torulopsis glabrata/Candida glabrata

Question 13

The “working yeast”

Answer 13

Saccharomyces cerevisiae

Question 14

Causative agent of meningitis and pulmonary disease

Answer 14

Cryptococcus spp.

Question 15

A major cause of opportunistic infection in patients with AIDS

Answer 15

Cryptococcus neoformans

Question 16

Found in soil contaminated with pigeon excreta

Answer 16

C. neoformans

Question 17

Responsible for the mucoid appearance of colonies of Cryptococcus spp.

Answer 17

Capsule

Question 18

Stain for Cryptococcus spp. capsule

Answer 18

India ink (negative stain)

Question 19

Today, India ink stain for Cryptococcus is being replaced with

Answer 19

Latex agglutination

Question 20

Latex agglutination detects

Answer 20

Cryptococcal antigen

Question 21

Urease reaction of Cryptococcus spp.

Answer 21

Urease positive

Question 22

Phenol oxidase reaction of C. neoformans

Answer 22

Phenol oxidase positive

Question 23

Media used to detect phenol oxidase production

Answer 23

Caffeic acid agar

Bird seed agar

Question 24

Closely related to Cryptococcus

Answer 24

Rhodotorula spp.

Question 25

Differentiating characteristic of Rhodotorula spp. from Cryptococcus spo.

Answer 25

Rhodotorula spp. are inositol negative

Question 26

Urease reaction of T. beigelii

Answer 26

Urease positive

Question 27

Seen in catheter-related infections in patients on long-term intravenous lipids

Answer 27

Malassezia furfur

Question 28

Most often recovered from environmental samples.

Microscopic: oval, elongated yeast cells, projectile spores

Answer 28

Sporobolomyces spp.

Question 29

Causative agent of Pneumocystis pneumonia

Answer 29

Pneumocystis jiroveci

Question 30

Disease caused by Pneumocystis jiroveci

Answer 30

Pneumocystis pneumonia

Question 31

Commonly used stain for P. jiroveci

Answer 31

GMS

Question 32

Appearance of P. jiroveci in GMS stain

Answer 32

Deflated ball

Question 33

Deflated ball appearance in GMS stain

Answer 33

P. jiroveci

Question 34

Media used for culture of P. jiroveci

Answer 34

Animals

Question 35

Yeast infections are often ____________.

Endogenous/exogenous

Answer 35

Endogenous