Micro: Intro to Mycology

Question 1

Are fungi eukaryotes or prokaryotes, and where are they found?

Answer 1

eukaryotes; found almost exclusively in soil, water, or on plants

Question 2

____ are asexual reproductive elements.

Answer 2

Conidia

Question 3

Spores are _________.

Answer 3

sexual reproductive elements.

Question 4

What are the two differences between fungi and animal cells that are medically exploited?

Answer 4

1. fungi have cell walls containing chitin

2. fungal membranes contain ergosterol instead of cholesterol

Question 5

____, a component of fungi cell membranes, that is a target for several anti-fungal drugs.

Answer 5

Ergosterol

Question 6

Regarding fungal morphology, ____ are single-celled and ____ are multi-celled fungi.

Answer 6

yeasts; molds

Question 7

Molds develop tube-like extensions called ____ that can be ____ or non-____.

Answer 7

hyphae; septate or non-septate

Question 8

An intertwined mass of hyphae is called a ____.

Answer 8

mycelium

Question 9

What is a dimorphic fungus?

Answer 9

a fungus that can grow in both yeast and mold form; yeast in tissue/37˚C in culture, and mold in culture at room temp

Question 10

Fungi cause 3 types of problems (in humans). Funging name them.

Answer 10

1. allergies
2. mycotoxicoses (eg, mushroom poisoning)
3. mycoses (true infections)

Question 11

Zygomycetes, ascomycetes, basidomycetes, and deuteromycetes are 4 ____ of fungal human pathogens.

Answer 11

phyla

Question 12

In increasing severity, working classifications of fungi include: superficial mycoses; ____ mycoses; subcutaneous mycoses; ____ mycoses, and ____ mycoses.

Answer 12

cutaneous; systemic; opportunistic

Question 13

Superficial mycoses often develop because of ____ ____.

Answer 13

poor hygiene

Question 14

What causes athlete’s foot and what working class of pathogen it is?

Answer 14

tineas; it’s a cutaneous mycosus

Question 15

Subcutaneous mycoses are often from wounds to the ____ and can involve the ____.

Answer 15

skin; lymphatics

Question 16

Inhalation of conidia or spores mostly causes what type of mycoses?

Answer 16

systemic

Question 17

What type of pathogenic fungal class can cause chronic infection resembling tuberculosis?

Answer 17

systemic mycoses

Question 18

____ mycoses can cause disease in healthy individuals, whereas ____ mycoses are found predominantly in immunocompromised patients.

Answer 18

systemic; opportunistic

Question 19

Do opportunistic mycoses respond to antibiotics?

Answer 19

Nope

Question 20

True or false: in general, fungi produce subacute, self-limiting infections in normally healthy individuals.

Answer 20

True .. so boring

Question 21

Among what patient population are fungal infections the most likely?

Answer 21

Among the immunocompromised, e.g., AIDS, chemotherapy, transplant patients

Question 22

What are some examination dimensions for diagnosing fungal infections?

Answer 22

• clinical appearance
• microscopic exam of samples treated with 10% KOH
• culture on Sabouraud’s medium
• biochemical assays
• serology

Question 23

What is the general rate of fungal metabolism, and how does this impact treatment?

Answer 23

their metabolism is generally slow, therefore treatment is for long periods of time (order of months)

Question 24

True or false: Antifungals are fairly toxic to the host.

Answer 24

True because fungi are eukayotes

Question 25

What are the 3 common targets of antifungal drugs?

Answer 25

1. ergosterol
2. cell wall
3. genome replication

Question 26

True or false: immunocompromised patients are not treated for fungal infections because something is going to kill them eventually. It’s probably going to be PKU.

Answer 26

False - you heartless SOB. On the contrary, immunocompromised patients are on prophylactic antifungals 4lyfe. And you can’t catch PKU.

Question 27

Do yeasts produce sexually or asexually?

Answer 27

they like it both ways–those dirty spores.
acospores = sexual
budding = asexual

Question 28

Candida albicans is what type of fungal pathogen (working class)?

Answer 28

opportunistic

Question 29

True or false: a popular virulence factor of many fungi is toxins.

Answer 29

False, there are actually no known toxins involved in human infection

Question 30

What key players of the immune system get really excited when they see fun guys coming?

Answer 30

• neutrophils - opportunistic molds are super sensitive to neutrophils
• T-cell immunity - real important
• antibodies - play a part in preventing reinfection

Question 31

DIsseminated infections are treated with ____ and/or ____.

Answer 31

amphotericin B and/or azoles

Question 32

Deutoermycetes - how do they do their sexual stage?

Answer 32

they don’t. like at all. and they’re still alive.

Question 33

What is sporotrichosis?

Answer 33

a disease marked by nodules or ulcers of the lymph nodes and skin; caused by sporothrix schenckii, a dimorphic fungus

Question 34

What is histoplasmosis?

Answer 34

infection by a fungus found in the droppings of birds and bats in humid areas. It is not serious if confined to the lungs but can be fatal if spread throughout the body.

Question 35

What is coccidioidomycosis?

Answer 35

the fungus that can be inhaled and cause valley fever

Question 36

Candidiasis is a fungal infection caused by ____ and appearing as what?

Answer 36

Candida albicans; appearing as oral or vaginal thrush