EDAPT Infection Practice Test

Polyenes, including amphotericin B and nystatin, target and bind to sterols, primarily ergosterol, which is a key component of fungal cell membranes. By binding to ergosterol, these drugs create pores in the fungal membrane, leading to increased permeability. This disrupts the integrity of the cell, causing vital cellular contents to leak out and resulting in cell death. Sterols are crucial for maintaining membrane stability and fluidity in fungi, making them a strategic target for antifungal treatment. The effectiveness of polyenes comes from their ability to exploit the unique composition of fungal cell membranes, enabling them to selectively affect fungal cells while sparing human cells, which predominantly contain cholesterol instead of ergosterol.