Microbial cell membrane and cell wall

The microbial cell membrane and cell wall are essential structural components that define the boundary and maintain the internal environment of bacteria and fungi (Nature Reviews Microbiology, 2017). The cell wall provides the necessary mechanical strength to withstand high internal osmotic pressure, primarily through a cross-linked peptidoglycan network in bacteria or glucan and chitin polymers in fungi (Microbiology Spectrum, 2015). Beneath the wall, the cytoplasmic membrane acts as a selective permeability barrier, facilitating nutrient uptake and energy transduction (Frontiers in Microbiology, 2019). These structures are primary targets for many of the most effective antimicrobial agents because they contain components absent in human cells, such as peptidoglycan and ergosterol (StatPearls, 2023). Drugs like beta-lactams and glycopeptides inhibit the assembly of the cell wall, leading to cell lysis, while lipopeptides and polyenes disrupt membrane integrity (NIH, 2022). Despite their success, the clinical utility of these drugs is increasingly threatened by the evolution of microbial resistance, including the production of degrading enzymes and structural modifications of the target (Nature Reviews Microbiology, 2017).

Other names

Bacterial cell wallFungal cell wallCytoplasmic membranePlasma membranePeptidoglycan layerMicrobial envelope

Drugs targeting these structures function by either inhibiting the biosynthesis of essential structural polymers, such as peptidoglycan in bacteria or beta-glucans in fungi, or by directly disrupting the physical integrity and permeability of the lipid bilayer (StatPearls, 2023). For example, beta-lactams inhibit penicillin-binding proteins (PBPs) to prevent cell wall cross-linking, while polymyxins act as surfactants to destabilize the membranes of Gram-negative bacteria (NIH, 2022).