Bacterial envelope

The bacterial envelope is a complex multi-layered structure that serves as the primary interface between a bacterium and its environment (Silhavy et al., 2010). It typically consists of the inner cytoplasmic membrane and a peptidoglycan cell wall; in Gram-negative bacteria, it also includes an outer membrane containing lipopolysaccharides (LPS) and a periplasmic space (Breijyeh et al., 2020). This structure is essential for maintaining cell shape, protecting against osmotic lysis, and regulating the transport of nutrients and waste. Because many components of the envelope, such as peptidoglycan, are unique to bacteria and absent in human cells, it is a premier target for antimicrobial therapy (Kapoor et al., 2017). Drugs targeting the envelope work by either inhibiting the synthesis of its structural components or directly disrupting the integrity of its membranes, leading to cell death. For instance, beta-lactams and glycopeptides target cell wall synthesis, while polymyxins and lipopeptides target membrane stability (StatPearls, 2023). However, the envelope also serves as a major barrier to drug entry, and modifications to its structure, such as changes in porin expression or LPS modification, are primary mechanisms of antibiotic resistance.

Other names

Bacterial cell envelopeBacterial cell wallBacterial membrane system

Inhibition of peptidoglycan synthesis (e.g., beta-lactams, glycopeptides), disruption of cytoplasmic membrane potential (e.g., lipopeptides), and disruption of outer membrane integrity via lipopolysaccharide binding (e.g., polymyxins).