Bacterial and fungal cytoplasmic membrane

The bacterial and fungal cytoplasmic membrane is a vital lipid bilayer that serves as the primary barrier between the cytoplasm and the external environment (Suller & Russell, 2000). In bacteria, it is the site of essential processes such as oxidative phosphorylation, nutrient transport, and the synthesis of cell wall components (Silhavy et al., 2010). In fungi, the membrane is characterized by the presence of ergosterol, which maintains structural integrity and fluidity (Odds et al., 2003). Because these membranes are essential for viability, they are major targets for antimicrobial and antifungal therapies. Drugs like polymyxins and daptomycin target bacterial membranes by inducing pore formation or depolarization (Heidary et al., 2018), while polyenes like amphotericin B target fungal membranes by binding to ergosterol to create lethal pores (Mesa-Arango et al., 2012). The primary therapeutic challenge lies in achieving selectivity to avoid toxicity toward host (human) cell membranes, which contain cholesterol instead of ergosterol or specific bacterial lipids (Zasloff, 2002).

Other names

Plasma membraneInner membraneCell membraneCytoplasmic membrane

Drugs targeting the cytoplasmic membrane typically act through direct physical disruption, such as pore formation (e.g., polyenes, polymyxins) or depolarization (e.g., daptomycin), or by inhibiting the synthesis of essential membrane components like ergosterol (e.g., azoles), leading to loss of cytoplasmic contents and cell death.