Fungi

Question 1

Beta-D-Glucan notably misses:

Answer 1

cryptococcus

the zygomycetes (mucor, etc)

blastomyces

Question 2

What are notable misses of amphotericin?

Answer 2

Aspergillus Terreus

Candida lusitanae (fluc/mica)

Candida auris (mica)

Scedosporium (vori)

+/-fusarium

Question 3

What does vori miss?

Answer 3

MUCOR (needs ampho/cresemba/posa)

Question 4

What does posa miss?

Answer 4

Nothing?

but break through can include:

• fusarium
• scedosporium (need vori or cresemba)

Question 5

Answer 5

these are rhizoids

aseptate hyphae

mucor lacks these - so this is likely either rhizopus or rhizomucor (of the most common)

Question 6

Answer 6

Aspergillus has 45⁰ angles (really only identifiable on path) and dandelion-head conidiophores VORI

Question 7

Answer 7

Fusarium has oval shaped microconidia and canoe-shaped macroconidia AMPHO+VORI

Question 8

Answer 8

Fusarium has oval shaped microconidia and canoe-shaped macroconidia AMPHO+VORI

Question 9

Answer 9

Scedosporium has single conidia on long conidiophores VORICONAZOLE

Question 10

Answer 10

Histoplasma looks like coronaviruses AMPHO/Itraconzazole

Question 11

Answer 11

Blastomyces looks like Christmas lights

AMPHO/VORI

Question 12

Answer 12

Sporothrix looks like grape clusters ITRA/AMPHO

Question 13

Answer 13

Cryptococcus

AMPHO+FLUC

Question 14

Answer 14

candida

Question 15

Answer 15

barrel-shaped arthroconidia - coccioides

Question 16

Answer 16

rosette shaped conidia

SPOROTHRIX

(also cigar-shaped yeast)

Question 17

Answer 17

lollipop conidia and broad based budding yeast (blasto)

Question 18

Answer 18

intracellular yeast - histoplasmosis

Question 19

What is the differential for this lesion?

Answer 19

Crypto

Histo

Molluscum

Talaromyces (penicillium)

(Smallpox?)

Question 20

64M from puerto rico p/w fevers, weight loss, dyspnea. Began two months ago and progressed. Now hypotensive, febrile and satting 88%.

SPlenomegally, hyponatremic, Pancytopenic, HIV+

PJP/TB on BAL negative

Dx?

Rx?

Answer 20

Disseminated Histoplasmosis

Can cause AI from infected adrenals

Start Amphotericin and Steroids(for AI)

Question 21

mechanism of voriconazole

Answer 21

inhibits lanosterol 14-a demthylase, disrupting ergosterol synthesis

Question 22

mechanism of amphotericin

Answer 22

binding ergosterol and altering membrane permeability

Question 23

mechanism of echinocandins

Answer 23

inhibit 13BDG syntehsis

Question 24

oval shaped yeast with a visible central septum

umbilicated lesions in HIV patient

Answer 24

(SE asia)

Talaromyces

*Histo/crypto clinically also could present with same syndrome, but would not have septum on microscopy

ampho/itra

Question 25

82F on TPN presents with fevers/chills. Line looks fine, cultures negative.

Answer 25

Add olive oil to look for Malassezia!

lipophilic yeast that causes tinea versicolor but can cause CLABSI in TPN patients.

Question 26

40M immunocomptetent man from michigan presents with fulminant pneumonia not responsive to standard therapy. Histo Ag positive. Verrucous Skin lesions.

Histo or Blasto?

Answer 26

Blasto - skin lesions more common in US, and blasto more commonly afflicts immunocompetent patients.

Question 27

Answer 27

narrow based budding yeast

histo

Question 28

Fungemia in cancer patient. Yeast is oval and budding, but crypto Ag is +

Answer 28

Trichosporon

pleomorphic budding yeast favors candida or trichosporon (crypto has no budding or psydohyae and is round)

Trichosporon can cause false crypto+ Ag

Question 29

patient on TPN develops fevers/hypotension. no improvement with ABX and routine blood Cx negative.

Dx?

Rx?

Answer 29

Malssezia

enrich culture media with olive oil

Rx with ampho or azole (intrinsically resistant to echinocandins)

Question 30

Answer 30

Histo

Question 31

Answer 31

Cocci endospore spherule

Question 32

Fontana Masson

Answer 32

Cryptococcus stain+