Thread by @BCMIDFellowship

1/Welcome #IDFellows #IDTwitter #MedTwitter to another #IDFungiFriday

🍄 For the next few tweetorials @A_Spallonii @BCMIDFellowship is presenting a refresher in Med Mycology
🍄 Today’s tweet will focus on basic terminology, 🔬 morphology, and intro to mycoses

2/Goals for these tweets

✅Make you more comfortable with med mycology
✅Learn something you didn’t know before about fungi (🍄)
✅Convince you that 🍄 are fundamental to life on 🌎

3/So let’s start with a question 👉 What are 🍄?

Fungi are organisms that ___

4/A: All of above
🍄 are awesome!

✅They are eukaryotes
✅🚫🌱 (RH Whittaker fixed this in 1969)
✅ They secrete digestive enzymes and absorb nutrients from decaying organic matter…or humans
✅They have super strong cell walls (chitin + glucans)

5/Classification/taxonomy
🍄dz names are hard – why⁉️@GermHunterMD

🔸Decades of tech advancement required to understand where 🍄 belong in 🌳 of life
🔸Occupy vast 🌎 niches
dry➡️humid
tropics➡️temperate
desert➡️deep sea
🔸Reproduce sexually and/or asexually

6/It doesn’t help that 🍄 with a known sexual stage have two names. Ex 👇
🔸One for anamorph (asexual) stage
🔸One for teleomorph (sexual) stage
This was basis of 🔬classification BUT IT’S CONFUSING

Genotypic i.d. makes dual nomenclature of organisms irrelevant

7/Morphology
2 main groups: molds vs yeasts

Molds have hyphae=“web” of filamentous structures➡️vegetative growth

Hyphae
🔹Are multicell, branching
🔹Can be septate=cross walls (most 🍄 are this)
🔹Or aseptate=no cross walls & wide/ribbonlike (💡Zygomycetes)

8/Yeast are oval-round, unicellular, and reproduce by budding

Some produce pseudohyphae
🚫 pseudohyphae aren’t hyphae
✅ they are elongated yeast cells with incomplete budding

9/Dimorphism
Most 🍄 are either a mold or yeast, but these 🍄 can be both! 👇
♦️Grow as molds at room temp (25-30C)
♦️Grow as yeast at incubator/body temp (35-37C)
Adaptive advantage➡️ sense/respond to enviro
Essential for pathogenicity/virulence/immune evasion➡️survival!

10/🍄are ubiquitous ➡️ 1.5mil species but only a few known to be human pathogens
Why?
🔷Most🍄can’t invade us because…
🔸Body temp
🔸Low redox potential in tissue
🔸Immune barriers
🔷Changes in host environment ➡️ opportunistic fungi

11/Basic features of 🍄 pathogens
🔹Affect immunocompetent/-compromised pts
🔹Can be chronic (💡ringworm) or acute/rapidly progressive (💡Mucor/AML)
🔹🚫person-to-person transmission (except dermatophytes)
🔹Tx: polyenes, azoles, echinocandins
🔹Tx often long & with AE's ☠️

12/A way to categorize 🍄 infxns 👉location

Superficial 🍄
🔷Colonize/affect keratinized tissue (💡dermatophytes)

Subcutaneous (SQ) 🍄
🔷Skin + contiguous SQ tissue/lymphatics
🔷From trauma/cutaneous implantation with botanical material (🌹gardener's disease🖐/🌴frond in👁)

13/
Systemic/Endemic 🍄
🔷Can infect ANY organ system and ANY host
🔷Caused by 🍄 that have a specific geographical niche in the 🌎

Opportunistic 🍄
🔷Considered non-pathogens (e.g. saprophytes) but infect w/loss of host innate and acquired immunity/1° immunodeficiencies

14/Over the next few weeks, we’ll have #IDFungiFriday #tweetorials on each #mycoses group

#IDFellows #IDTwitter #IDMedEd what about 🍄 do you want to know more about?
@ID_fellows @VUMC_IDFellows @BCMPedIDFellows @jeffIDfellows @BIDMC_IDFellows @YaleIDFellows @UCLA_ID @iupedsID

15/@CHPpedifellow @tufts_id @UniversityMD_ID @DCPedsID @IUIDfellowship @MGHBWHIDFellows @MSBIMWIDFellows @BrownIDprogram @RushCCH_ID @mgh_id @ID_MUSC @OhioState_ID @id_bcm @UofA_ID @UNMC_ID @eurconfmedmycol @FungiScope @MSAFungi @TXMedCenter @MSG_ERC @DrFungus_MSGERC @AST_IDCOP