Terms and Procedures

Question 1

BHI

Answer 1

Chloramphenical and cycloheximide (suppress fast growing saprophytes and bacteria)
Growth of Histoplasma capsulatum and Blastomyces dermatitidis

Question 2

Mycosel Agar

Answer 2

Primary recovery of dermatophytes

Question 3

Cornmeal Agar (CMA)

Answer 3

Identification of C. albicans

Question 4

Niger Seed Agar (aka Bird Seed)

Answer 4

Identification of Cryptococcus neoformans

Question 5

Potato Dextrose Agar (PDA)

Answer 5

Stimulate the sporulation of dermatophytes

Question 6

Christensen’s Urea Agar

Answer 6

Used to differentiate between:
Cryptococcus species (negative) or Cryptococcus neoformans (positive)
T. mentagrophytes (positive) or T. rubrum (negative)
Trichosporon (positive)

Question 7

Rapid Growers

Answer 7

< 7 days
Most saprophytes
Mucormycetes (Zygomycetes)
Coccidiodes immitus
Yeast

Question 8

Moderate Growers

Answer 8

7-10 days
Dermatophytes (most)
Some saprophytes
Sporothrix schenkii

Question 9

Slow Growers

Answer 9

> 10 days
Subcutaneous dematiaceous fungi (Phialophora, Cladophialophora, & Fonsecaea)
Dermatophytes (a few)
Systemic dimorphic fungi except Coccidiodes immitus

Question 10

Topography

Answer 10

Flat (no topography)
Raised, folded, verrucose (wrinkled, convoluted, or wart-like)
Cerebriform (brain-like)
Rugose (deep furrows irregularly radiating from center)
Umbonate (button like central elevation)

Question 11

Septate

Answer 11

Subdivided into individual cells by transverse walls or septa

Question 12

Aseptate

Answer 12

Without transverse septa or walls

Question 13

Aerial mycelium

Answer 13

Grows above the substrate and supports development of fruiting bodies

Question 14

Vegetative mycelium

Answer 14

Extends downward into the nutrient substrate

Question 15

Favic chandeliers

Answer 15

Terminal hyphal branches that are irregular, broad, and antler or moose-like appearance
Characteristic in Trichophyton schoenleinii

Question 16

Spiral hyphae

Answer 16

Form coiled or cork-screw like turns
Commonly seen in Trichophyton species

Question 17

Asexual Reproduction

Answer 17

Involves nuclear and cytoplasmic division in which 2 daughter cells contain same genetic information as one parent.
Seen most commonly in fungi

Question 18

Poroconidia

Answer 18

Found in Bipolaris
Fruiting bodies are formed by daughter cell pushing through a minute pore in parent cell (conidiophore)

Question 19

Annelloconidia

Answer 19

Found in Scopulariopsos
Arise from inside a vase-shaped structure called annellide

Question 20

Blastospores/Blastoconidia

Answer 20

Budding forms produced by yeast
Cells are produced by budding when daughter cell is pinched off from portions of mother cell

Question 21

Pseudohyphae

Answer 21

Elongated blastoconida that remain attached from structures called pseudohyphae

Question 22

Chlamydospores/Chlamydoconia

Answer 22

Round, thick-walled resistant spores
Observed at the hyphal tip (chlamydospores), on the sides of hyphae (sessile chlamydospores), or within the hyphal strand (intercalary chlamydospores)

Question 23

Arthrospores/Arthroconidia

Answer 23

Formed directly on hyphae by fragmentation through points of septation.
Mature they appear as square, rectangular, or barrel-shaped, thick-walled cells

Question 24

Tease Mount

Answer 24

Small portion of colony including some of the subsurface is dug out with a pair of dissecting needles
Colony is teased apart with needles and overlaid with a cover slip

Question 25

Scotch Tape Prep

Answer 25

Spore arrangement of more delicate molds are better preserved Using frosted, clear cellophane tape, press sticky side gently but firmly to surface of the colony Place a drop of LPCB Stick end of tape to surface of slide

Question 26

Slide Culture

Answer 26

Method used when tease mount of scotch tape prep cannot establish an accurate ID Media is placed onto the glass slide Organism inoculated on media Cover slip placed on top and incubated

Question 27

Hair Perforation Test

Answer 27

Obtain light colored hair from child and place into tube Add 20-25 mL of sterile DI Place several fragments of fungal culture into tube Incubate and look for positive reaction

Question 28

India Ink Prep

Answer 28

India Ink is placed on slide Spinal Fluid or small amount of isolated yeast is added Add cover slip Look for capsulated yeast cells

Question 29

Calcofluor White Stain

Answer 29

Binds to beta 1-3 and 1-4 polysaccharides Fluoresces when exposed to UV radiation Fungal elements stand out as bright apple green on a red background

Question 30

Acid Fast Stain for Ascopores

Answer 30

Ascospores stain green Vegetative cells stain red

Question 31

Acid Fast Stain (Modified)

Answer 31

Nocardia species appear at least partially acid fast

Question 32

KOH Prep

Answer 32

10% KOH is used to clear debris and dissolve keratinous material from skin, hair, and nails

Question 33

Latex agglutination

Answer 33

Test for Cryptococcus neoformans in CSF

Question 34

Wrights Giemsa Stain

Answer 34

Detect intracellular yeast forms of Histoplasma capsulatum in bone marrow

Question 35

Mycotic

Answer 35

infection with fungus or disease caused by fungus

Question 36

Keratitis

Answer 36

Inflammation of the cornea

Question 37

Mycetomas

Answer 37

chronic, progressively destructive infectious disease of the subcutaneous tissues that spreads to affect the skin, deep tissues, and bone

Question 38

Keratomycosis

Answer 38

invasive infection of corneal stroma

Question 39

Onychomycosis

Answer 39

fungal infection of the nail unit

Question 40

Phaeohyphomycosis

Answer 40

Rare mycotic infection caused by various heterogenous groups of phaeoid (dematiaceous) fungi involving the skin and subcutaneous tissue