Fungal

Question 1

If Mississippi/Ohio river valley is mentioned in the stem of the question, and the person has a possible fungal infection, what fungus is it?

Answer 1

Histoplasma capsulatam

Question 2

If rotting wood in eastern US is mentioned in the stem of the question, and the person has a possible fungal infection, what fungus is it?

Answer 2

Blastomyces dermatitidis

Question 3

If “valley fever” or southwest US is mentioned in the stem of the question, and the person has a possible fungal infection, what fungus is it?

Answer 3

Cocidioides immitis

Question 4

Besides geographical location, what else would implicate a coccidioides immitis infection?

Answer 4

Pulmonary lesions may calcify

Question 5

How does amphotericin B kill fungi?

Answer 5

Binds ergosterol –> holes in membrane –> leakage of electrolytes

Question 6

What is the side effect of amphotericin B?

Answer 6

Binds to cholesterol –> decreases renal blood flow –> destroys BM

Question 7

Is there resistance to amphotericin B?

Answer 7

Rarely…there can decreased ergosterol in the membrane

Question 8

What do aspergillus fumigatus usually infect?

Answer 8

Lungs… hypersensitivity forms fungal balls with eosinophils (Allergic BronchoPulmonary Aspergillosis…ABPA)

Question 9

What can be used to treat ABPA?

Answer 9

Voriconazole (antifungal)

Prednisone

Question 10

How do azoles (voriconazole or itraconazole) work?

Answer 10

Binds fungal P450 enzyme (Erg11) –> inhibits synthesis of ergosterol –> build up of toxic lanosterol

Question 11

What toxicities do azoles have?

Answer 11

Drug-drug interactions
Hepatotoxicity*
Neurotoxicity
Alters hormone synthesis –> avoid during pregnancy

Question 12

What causes the resistance to azoles?

Answer 12

Altered P450

Upregulation of efflux transporters

Question 13

Is metronidazole an azole?

Answer 13

No…heck no…fuck no