Bacterial cell envelope and biofilm matrix

The bacterial cell envelope and biofilm matrix represent a broad category of structural targets rather than a single molecular entity. The cell envelope includes the cytoplasmic membrane and the peptidoglycan cell wall, which are essential for maintaining bacterial cell integrity and protecting against osmotic lysis (Silhavy et al., 2010, Cold Spring Harb Perspect Biol). In Gram-negative bacteria, this structure also encompasses an outer membrane that acts as a barrier to many antibiotics and contains lipopolysaccharides. The biofilm matrix is a distinct extracellular polymeric substance (EPS) composed of polysaccharides, proteins, and extracellular DNA that encases bacterial communities (Flemming and Wingender, 2010, Nat Rev Microbiol). This matrix provides a physical shield against host immunity and significantly reduces the penetration of antimicrobial agents. While these structures are functionally related in providing protection, they involve distinct biochemical components and are targeted by different classes of drugs. For example, beta-lactams target cell wall synthesis, whereas anti-biofilm agents like dornase alfa target the matrix components to sensitize bacteria to treatment. Because this target definition combines multiple complex systems, it is often subdivided into more specific targets in drug discovery contexts.

Other names

Bacterial cell wallExtracellular polymeric substances (EPS)Bacterial integumentBiofilm extracellular matrixBacterial surface structures

Inhibition of peptidoglycan transpeptidation, binding to cell wall precursors (e.g., Lipid II), disruption of cytoplasmic or outer membrane integrity, and enzymatic degradation of extracellular matrix components like eDNA.