Quiz 2 - Hanson - Intro To Mycology

Question 1

What is mycology?

Answer 1

Study of yeasts and molds

Question 2

T/F - Fungi are eukaryotes.

Answer 2

TRUE

*Ubiquitous in nature

Question 3

What is in the cell walls of yeasts and molds?

Answer 3

CHITIN

*Also beta-glucans

Question 4

What is ergosterol?

Answer 4

A lot like cholesterol, but different, and we can target that with drugs. Gives the cell membrane rigidity

Question 5

Contrast yeasts vs. molds

Answer 5

Yeasts
-Single cells
-Culture is:
—Single colonies
—Creamy, mucoid
—FACULTATIVE ANAEROBES

Molds
-Multicellular, filamentous
-Hyphae
—These can interweave to form a mycelium mat
-Culture is:
—Fuzzy, velvety
—OBLIGATE AEROBES

Question 6

What is the micro term for a bud of a yeast?

Answer 6

Blastoconidia

Question 7

What are chains of blastoconidia called?

Answer 7

Pseudohyphae (yeast)

*These have distinctive indents, or pinches, in them, not a continuous tube

Question 8

What yeast can make true hyphae?

Answer 8

Candida albicans

Question 9

What is a germ tube?

Answer 9

A true hyphael element

Question 10

True hyphae have two divisions. Name them.

Answer 10

Septate- Aspergillus - look like pseudohyphae, but are true hyphae. They are not tapered at the end of the tube

Nonseptate/Aseptate - Zygomycete - Germ tube

Question 11

What is the asexual state of yeasts and molds called?

Answer 11

Anamorph

*Mitotic division of a haploid nucleus - budding for yeasts, conidia or separation of hyphael elements

Question 12

What is the sexual state of yeasts/molds called?

Answer 12

Telomorph

*Diploid nucleus divides by meiosis - Haploid nuclei of donor and recipient fertile cells fuse for yeasts, for molds, spores are used

Question 13

What does dimorphism fungi mean?

Give 3 important species that exhibit dimorphism.

Answer 13

Group of geographically restricted pathogens that exist as a mold at RT and a yeast at BT

Blastomyces dermatitidis
Coccidiodes immitis/posadasii
Histoplasma capsulatum/duboisii

Question 14

What does opportunistic fungi mean?

Answer 14

Only cause disease in compromised hosts

Question 15

Give 5 risk factors for yeast/fungal infections.

Answer 15

Immunocompromised
-organs recipients
-HIV
-Autoimmune disease
Premature infants
Critically ill and hospitalized patients
Travelers and residents of endemic areas
Direct contact with animals or infected materials

Question 16

What are three methods to ID specimens?

Answer 16

Direct microscopy - Fast, cheap

Culture - Gold standard from sterile body site

Histopathology - Gold standard for invasive disease

Question 17

If you have a pure culture, what are 2 methods used for IDing?

Answer 17

Proteomic ID - MALDITOFMS - Matrix assisted laser desorption ionization time of flight mass spectrometry

Targeted gene sequencing

Question 18

What are the 2 most common candida types?

Answer 18

Albicans, glabrata

*Thrush, vaginitis, esophagitis, etc.

**GLABRATA RESISTANT TO FLUCONAZOLE

Question 19

T/F - Rhinocerebral zygomycosis is angioinvasive.

Answer 19

TRUE - It follows blood vessels. Lady with large mass and pain in her maxillary sinus