Echinocandins are not active against which organisms?

Echinocandins are not active against which organisms?

• A. Cryptococcus and Mucorales
• B. Candida
• C. Aspergillus
• D. Histoplasma

Answer: (A)

Echinocandins target the fungal cell wall by inhibiting beta-1,3-glucan synthase, which blocks the production of beta-1,3-glucan, a key structural component in many fungi. Because Candida species rely on this glucan for their cell wall integrity, echinocandins are highly effective against invasive candidiasis. They also show some activity against other molds, such as Aspergillus, though they are not preferred monotherapy for aspergillosis and are not as reliably effective as for Candida. The two organisms in which this drug class has essentially no useful activity are Cryptococcus and Mucorales. Cryptococcus neoformans has relatively low beta-1,3-glucan content in its cell wall and relies on other structural features, so blocking glucan synthesis doesn’t compromise it. Mucorales (the agents of Mucor, Rhizopus infections) have little beta-1,3-glucan and rely on different wall components, making them intrinsically resistant to echinocandins. So, echinocandins aren’t active against Cryptococcus and Mucorales, which is why those organisms are the correct selection.

Echinocandins target the fungal cell wall by inhibiting beta-1,3-glucan synthase, which blocks the production of beta-1,3-glucan, a key structural component in many fungi. Because Candida species rely on this glucan for their cell wall integrity, echinocandins are highly effective against invasive candidiasis. They also show some activity against other molds, such as Aspergillus, though they are not preferred monotherapy for aspergillosis and are not as reliably effective as for Candida.

The two organisms in which this drug class has essentially no useful activity are Cryptococcus and Mucorales. Cryptococcus neoformans has relatively low beta-1,3-glucan content in its cell wall and relies on other structural features, so blocking glucan synthesis doesn’t compromise it. Mucorales (the agents of Mucor, Rhizopus infections) have little beta-1,3-glucan and rely on different wall components, making them intrinsically resistant to echinocandins.

So, echinocandins aren’t active against Cryptococcus and Mucorales, which is why those organisms are the correct selection.