Mucus glycoproteins and bacterial biofilm matrix

Mucus glycoproteins, primarily gel-forming mucins like MUC5AC and MUC5B, are the structural backbone of the protective mucus layer in the respiratory and gastrointestinal tracts (PubMed: 28832566). In chronic infections, these glycoproteins often co-mingle with the bacterial biofilm matrix, a complex assembly of extracellular polymeric substances (EPS) including polysaccharides, proteins, and extracellular DNA (eDNA) (PubMed: 23622218). This combined matrix serves as a robust physical and chemical shield that protects pathogens from host immune responses and significantly hinders the penetration of antimicrobial therapies. In conditions such as cystic fibrosis and chronic obstructive pulmonary disease (COPD), the accumulation of hyperviscous mucus and biofilms leads to severe airway obstruction and persistent inflammation (NIH: Cystic Fibrosis). Therapeutic interventions target this complex through mucolytics that reduce disulfide bonds in mucins and enzymes like dornase alfa that degrade eDNA to lower viscosity (PubChem: Dornase alfa). By compromising the structural integrity of the mucus-biofilm complex, these agents facilitate mechanical clearance and enhance the efficacy of co-administered antibiotics.

Other names

MucinsExtracellular Polymeric Substances (EPS)Biofilm matrixMucus-biofilm complexGel-forming mucins

Reduction of disulfide bonds in mucin polymers, enzymatic degradation of extracellular DNA, and hydrolysis of biofilm-associated polysaccharides to decrease viscoelasticity and promote clearance.