Bacterial cell wall and periplasmic membrane components

The bacterial cell wall and periplasmic membrane components constitute the essential protective envelope of bacteria, providing structural rigidity and protection against osmotic pressure (Silhavy et al., 2010). In Gram-positive bacteria, this consists primarily of a thick peptidoglycan layer, while Gram-negative bacteria possess a thinner peptidoglycan layer situated within a periplasmic space between an inner cytoplasmic membrane and an outer membrane containing lipopolysaccharides (Sarkar et al., 2017). These structures are critical for bacterial survival and are the primary targets for several major classes of antibiotics, including beta-lactams, glycopeptides, and polymyxins. Drugs targeting the cell wall typically inhibit the synthesis or cross-linking of peptidoglycan, leading to cell lysis, whereas those targeting the membranes disrupt lipid bilayer integrity (Poirel et al., 2017). Because these structures are unique to prokaryotes or significantly different from eukaryotic membranes, they offer high therapeutic indices. However, the emergence of resistance mechanisms like beta-lactamase production and membrane alterations remains a significant clinical challenge in treating bacterial infections.

Other names

Bacterial cell envelopePeptidoglycan layerBacterial cell wallPeriplasmic spaceInner and outer bacterial membranes

Inhibition of peptidoglycan synthesis by binding to penicillin-binding proteins (PBPs), inhibition of cell wall cross-linking via glycopeptide binding to D-Ala-D-Ala, and disruption of membrane integrity through detergent-like interactions with phospholipids and lipopolysaccharides (Sarkar et al., 2017; Poirel et al., 2017).