Fungi basics and drugs Flashcards
There are 3 classes of fungi that cause human infection, namely A__, B___ and M___
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)
Which yeast is the only one with a capsule and commonly affects HIV patients? (hint: its one of the Basidiomycetes)
Cryptococcus is a real gansta – it’s the only yeast that has a CAPSULE (and remember this the nigga that affects HIV patients)
Which yeast has hyphae, pseudohyphae and yeast?
Candida albicans (your bug candida in your room)
Candida albicans has 2 important distinguishing features: the pseudohypha, and __ (hint: looks the handle of a ping pong paddle)
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**
Name an organism that has dichotomous and septate hyphae
Apsergillus is a dichotomously branching, septate organism (septate just means its segmented, kinda like a segmented worm)
Name an organism that has right angled, non septate hypha
Mucormycetes (e.g. Rhizopus spp)
Fungi can exist in 2 forms, namely__
Mould and yeast
What is the difference between mould and yeast?
Mould are what they are in the environment
Yeast: what they become inside our bodies when we inhale their spores!
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)
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
State the features of Blastomyces in the body
Blastomyces in the host: pyogranulomatous infection with a bunch of budding yeast
State the features of Coccidiodes in the body
Spherical yeast; releases endospores that damage the lungs
(coccidiodes got spores in spheres!)
State the features of Histoplasma in the body
Makes tiny yeast forms that sequester themselves within macrophages
(Histoplasma hides in macrophages)
What is the role of a capsule in fungi?
Antiphagocytic/basically immune system evasion
The main components of a fungal cell wall are ___
Mannoproteins
Beta (1, 3) glucans
Chitin
What is the carbohydrate that is in Aspergillus that is not in Candida spp?
Galactomannan
A __ polymorphism puts one at increased risk for apsergillosis and candidiasis infection
TLR4
Polymorphisms in MBL and __ cause an increased risk of Candidiasis
MBL (esp in kids, pediatric oncology patients), and Dectin-1
(D comes after C, D for dectin 1 polymorphism)
__ have simple septa, Basidiomycetes produce ___ and ___ have few - no septa
Ascomycetes - have simple septa
Basidiomycetes - produce elaborate septa (called dolipore)
Mucormycetes - few to no septa
Which bug is this?
These are Aspergillus conidia
Which bug is this?
This is Rhizopus (mucorales sporangiospores)
Name 5 virulence factors of fungi
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)
Which fungi will only exhibit budding yeast forms in tissues?
cryptococcosis, histoplasmosis, blastomycosis, and sporotrichosis
(tales from the crypts: a history of the blast of the spor-os)
Which fungi exhibit budding yeast forms AND hyphae
Candidiasis
Tinea versicolor
(A CT has no color?)
Which particular fungus exists as a spherule in tissues?
coccidiodomycosis
Which stain is used to differentiate host response, but not sensitive for detection of fungi? (hint: this is a very standard go to stain)
H and E
Which stain stains the polysaccharide wall of fungi? (hint: name sounds like Sheriff)
Periodic acid schiff
The GMS stain is a silver stain that does what 2 things?
Stains fungal cell wall silver and allows one to see background of cellular response
Mucicarmine/Alcian blue stain which organism?
Mucicarmine/Alcian blue: specifically for Cryptococcus neoformans capsule
What does Fontana Masson stain?
stains melanin (Fontana Masson is this white dude that ain’t got no melanin so he stains himself brown)
What are the 4 categories used to classify fungal infections?
Superficial
Mucocutaneous
Subcutaneous
Deep mycoses (opportunistic, pathogenic)
