Yeast and Fungi characteristics

Question 1

Normal Flora of skin, mucous membrane, and gastrointestinal tract, Dimorphic fungi which produce yeast and hyphae

Answer 1

Candida albicans

Question 2

Candida chromagar green

Answer 2

C. albicans

Question 3

Candida chromagar blue

Answer 3

C. tropicalis

Question 4

Candida chromagar white (fungemia in neonatal ICU)

Answer 4

C. parapsilosis

Question 5

Candida chromagar pink/purple

Answer 5

C. glabrata

Question 6

Risk factors for Candida albicans

Answer 6

Pregnancy, Newborn, HIV, Diabetes, Malnutrition, Prolonged use of antibiotics, Chemotherapy

Question 7

Disease caused by C. albicans

Answer 7

Thrush, Moniliasis, Oroesophageal candidiasis, Intertriginous candidiasis, Paronychia, Respiratory infections, Eye infection, Endocarditis, Meningitis

Question 8

Germ tube test

Answer 8

0.05mL serum + yeast (35-37˚C for 1-3 hrs) (POSITIVE - no constriction/tube-like projections)

Question 9

Chlamydospore formation confirmatory test

Answer 9

Cornmeal agar (Room temperature for 2-3 days)

Question 10

Produces chlamydospore, blastoconidia, pseudohyphae and true hyphae

Answer 10

Candida albicans

Question 11

Transmitted through pigeon droppings via inhalation by humans

Answer 11

Cryptococcus neoformans

Question 12

Virulence factor of Cryptococcus neoformans

Answer 12

Capsule (anti-phagocytic), Phenoloxidase (melanin production)

Question 13

Disease caused by Cryptococcus neoformans

Answer 13

Meningitis and Torulosis (opportunistic)

Question 14

Screening test for C. neoformans

Answer 14

India ink of CSF (yeast with halo +), Inositol, Urease, Nitrate assimilation, Phenol oxidase, Birdseed agar + Latex agglutination (w/ CSF)

Question 15

Detects CAD (cryptococcal antigen)

Answer 15

Latex agglutination test

Question 16

Bright salmon pink color

Answer 16

Rhodotorula spp

Question 17

Causes opportunistic infections and is rare

Answer 17

Rhodotorula spp

Question 18

Resemblance cryptococcus; have capsule and are urease positive

Answer 18

Rhodotorula spp

Question 19

Common yeast used in baking and food products

Answer 19

Saccharomyces cerevisiae

Question 20

Benefit of Saccharomyces cerevisiae

Answer 20

Used in probiotics for treating antibiotic-resistant diarrhea, inflammatory bowel disease, and malabsorption syndrome

Question 21

Fungi that are like protozoa with 3 stages: 1. Trophozoite (irregular shaped), 2. Precyst, 3. Cyst (infective stage)

Answer 21

Pneumocystis jirovecii

Question 22

Infective stage of P. jirovecii

Answer 22

Cyst with up to 8 intracystic bodies (punched-out appearance)

Question 23

Pneumocystis found in rats

Answer 23

Pneumocystis carinii

Question 24

Primary pneumonia of AIDS patients

Answer 24

Pneumocystis jirovecii

Question 25

Specimen for P. jirovecii diagnosis

Answer 25

Bronchoalveolar lavage (BAL) fluid, transbronchial biopsy, tracheal aspirate, pleural fluid, induced sputum

Question 26

Staining methods for P. jirovecii

Answer 26

Giemsa, Gomori Methenamine Silver (GMS), Calcofluor

Question 27

Malassezia furfur

Answer 27

Tinea versicolor (Pityriasis versicolor)

Question 28

Malassezia furfur appearance

Answer 28

Fawn-colored liver spots or patches in skin

Question 29

Sample for Malassezia furfur

Answer 29

Skin scraping at room temperature

Question 30

Test for Malassezia furfur

Answer 30

10% KOH (dandruff), spaghetti and meatball appearance on SDA with olive oil (lipids), Wood's lamp

Question 31

Piedraia hortae

Answer 31

Black piedra, hard, dark brown to black gritty nodules in hair shaft

Question 32

Sample for Piedraia hortae

Answer 32

Hair sample at room temperature, 10% KOH

Question 33

Trichosporon spp. T. asahii

Answer 33

Immunocompromised patients

Question 34

Trichosporon spp. T. mucoides

Answer 34

Meningitis

Question 35

Trichosporon spp. appearance

Answer 35

White piedra, soft white nodules in hair shaft

Question 36

Sample for Trichosporon spp.

Answer 36

Hair, 10% KOH

Question 37

Test for Trichosporon spp.

Answer 37

KNO3, CHO assimilation (Non-fermenter), Urease positive

Question 38

Hortaea werneckii

Answer 38

Tinea nigra

Question 39

Hortaea werneckii appearance

Answer 39

Brown to black non-scaly macules, most often on palms and soles

Question 40

Sample for Hortaea werneckii

Answer 40

Skin scraping, 10% KOH