Fungi basics and drugs

Question 1

There are 3 classes of fungi that cause human infection, namely A__, B___ and M___

Answer 1

Ascomyctes (that *ss CO is on my cete! (seat)

Basidiomycetes (includes mushrooms and Cryptococcus – affects the brain and causes infection in HIV patients)

Mucormycetes – destroy sinuses, go into brain and kill (mucormycetes kill your mucus, mygrate to your brain and cete it on fire)

Question 2

Which yeast is the only one with a capsule and commonly affects HIV patients? (hint: its one of the Basidiomycetes)

Answer 2

Cryptococcus is a real gansta – it’s the only yeast that has a CAPSULE (and remember this the nigga that affects HIV patients)

Question 3

Which yeast has hyphae, pseudohyphae and yeast?

Answer 3

Candida albicans (your bug candida in your room)

Question 4

Candida albicans has 2 important distinguishing features: the pseudohypha, and __ (hint: looks the handle of a ping pong paddle)

Answer 4

A germ tube!!

Candida albicans is Germ tube positive: identification clue. When you incubate in RPMI solution or serum solution, within 2 hrs @ 37degrees, an elongated structure forms (it makes the yeast look like a ping pong paddle handle)

**non albicans species tend to be resistant to meds so you need to know which kinda Candida you’re dealing with**

Question 5

Name an organism that has dichotomous and septate hyphae

Answer 5

Apsergillus is a dichotomously branching, septate organism (septate just means its segmented, kinda like a segmented worm)

Question 6

Name an organism that has right angled, non septate hypha

Answer 6

Mucormycetes (e.g. Rhizopus spp)

Question 7

Fungi can exist in 2 forms, namely__

Answer 7

Mould and yeast

Question 8

What is the difference between mould and yeast?

Answer 8

Mould are what they are in the environment

Yeast: what they become inside our bodies when we inhale their spores!

Question 9

Name 3 of the thermally dimorphic fungi (hint: when you’re having a blast with a bunch of nerds, you open a wine bottlewith a cockscrew and watch the histry channel on a plasma screen)

Answer 9

when you’re having a blast with a bunch of nerds, you open a wine bottle with a cockscrew and watch the history channel on a plasma screen:

Blastomyces

Coccidiodes

Histoplasma

Question 10

State the features of Blastomyces in the body

Answer 10

Blastomyces in the host: pyogranulomatous infection with a bunch of budding yeast

Question 11

State the features of Coccidiodes in the body

Answer 11

Spherical yeast; releases endospores that damage the lungs

(coccidiodes got spores in spheres!)

Question 12

State the features of Histoplasma in the body

Answer 12

Makes tiny yeast forms that sequester themselves within macrophages

(Histoplasma hides in macrophages)

Question 13

What is the role of a capsule in fungi?

Answer 13

Antiphagocytic/basically immune system evasion

Question 14

The main components of a fungal cell wall are ___

Answer 14

Mannoproteins

Beta (1, 3) glucans

Chitin

Question 15

What is the carbohydrate that is in Aspergillus that is not in Candida spp?

Answer 15

Galactomannan

Question 16

A __ polymorphism puts one at increased risk for apsergillosis and candidiasis infection

Answer 16

TLR4

Question 17

Polymorphisms in MBL and __ cause an increased risk of Candidiasis

Answer 17

MBL (esp in kids, pediatric oncology patients), and Dectin-1

(D comes after C, D for dectin 1 polymorphism)

Question 18

__ have simple septa, Basidiomycetes produce ___ and ___ have few - no septa

Answer 18

Ascomycetes - have simple septa

Basidiomycetes - produce elaborate septa (called dolipore)

Mucormycetes - few to no septa

Question 19

Which bug is this?

Answer 19

These are Aspergillus conidia

Question 20

Which bug is this?

Answer 20

This is Rhizopus (mucorales sporangiospores)

Question 21

Name 5 virulence factors of fungi

Answer 21

Cell surface receptors

Hydrolytic enzymes

Host mimicry

Polysaccharide capsule (only Cryptococcus really)

Melanin production

**

Host mimicry (e.g. Candida)

Melanin production: e.g. Aspergillus has melanin on its conidia that allow it to bypass host defense and establish itself in the lungs; Cryptococcus has melanin that serves as an oxidative sink (absorbs the oxidative intermediates produced by immune cells)

Question 22

Which fungi will only exhibit budding yeast forms in tissues?

Answer 22

cryptococcosis, histoplasmosis, blastomycosis, and sporotrichosis

(tales from the crypts: a history of the blast of the spor-os)

Question 23

Which fungi exhibit budding yeast forms AND hyphae

Answer 23

Candidiasis

Tinea versicolor

(A CT has no color?)

Question 24

Which particular fungus exists as a spherule in tissues?

Answer 24

coccidiodomycosis

Question 25

Which stain is used to differentiate host response, but not sensitive for detection of fungi? (hint: this is a very standard go to stain)

Answer 25

H and E

Question 26

Which stain stains the polysaccharide wall of fungi? (hint: name sounds like Sheriff)

Answer 26

Periodic acid schiff

Question 27

The GMS stain is a silver stain that does what 2 things?

Answer 27

Stains fungal cell wall silver and allows one to see background of cellular response

Question 28

Mucicarmine/Alcian blue stain which organism?

Answer 28

Mucicarmine/Alcian blue: specifically for Cryptococcus neoformans capsule

Question 29

What does Fontana Masson stain?

Answer 29

stains melanin (Fontana Masson is this white dude that ain’t got no melanin so he stains himself brown)

Question 30

What are the 4 categories used to classify fungal infections?

Answer 30

Superficial

Mucocutaneous

Subcutaneous

Deep mycoses (opportunistic, pathogenic)