Bacterial cell surface and biofilm extracellular matrix (EPS)

The bacterial cell surface and biofilm extracellular matrix (ECM) represent a complex, multi-component structure that serves as the primary interface between bacteria and their environment. The cell surface includes the peptidoglycan layer, outer membrane (in Gram-negative species), and various appendages, while the biofilm ECM, often termed extracellular polymeric substances (EPS), consists of a self-produced mixture of polysaccharides, proteins, lipids, and extracellular DNA (eDNA) (Flemming & Wingender, 2010, Nature Reviews Microbiology). These structures provide mechanical stability, facilitate adhesion to surfaces or host tissues, and act as a protective barrier against environmental stressors, host immune responses, and antimicrobial agents (Silhavy et al., 2010, Cold Spring Harbor Perspectives in Biology). In clinical settings, biofilms are a major cause of chronic and persistent infections, such as those found in cystic fibrosis lungs, chronic wounds, and on medical implants (NIH, 2023). Therapeutic strategies targeting these structures include traditional antibiotics that inhibit cell wall synthesis or disrupt membranes, as well as emerging anti-biofilm agents designed to degrade the ECM or inhibit the signaling pathways, such as quorum sensing, that regulate its production (PubMed, 2021).

Other names

Biofilm matrixExtracellular polymeric substancesBacterial envelopeBacterial cell wallExopolysaccharide matrix

Drugs targeting this complex structure work by inhibiting peptidoglycan synthesis (e.g., Vancomycin), disrupting the integrity of the cytoplasmic or outer membrane (e.g., Daptomycin, Colistin), or enzymatically degrading the components of the biofilm matrix such as extracellular DNA or polysaccharides (e.g., Dornase alfa, Dispersin B).