Extracellular divalent cations

Extracellular divalent cations, specifically calcium (Ca2+) and magnesium (Mg2+), are fundamental structural components of the bacterial biofilm matrix. These ions function by forming ionic bridges between negatively charged components of the extracellular polymeric substance (EPS), including polysaccharides, extracellular DNA (eDNA), and proteins (Mulcahy et al., 2008, Journal of Bacteriology). This cross-linking provides mechanical stability to the biofilm, protecting the bacterial community from environmental stressors, host immune defenses, and antibiotic penetration (Whitchurch et al., 2002, Science). In clinical contexts, these cations contribute to the persistence of chronic infections in conditions like cystic fibrosis and on indwelling medical devices (Banin et al., 2006, Applied and Environmental Microbiology). Targeting these ions with chelating agents such as EDTA or citrate destabilizes the biofilm architecture, promoting its dissolution and enhancing the effectiveness of traditional antimicrobial therapies (Percival et al., 2005, Journal of Wound Care).

Other names

Biofilm matrix cationsExtracellular calcium and magnesiumEPS-associated divalent cationsBiofilm-associated divalent cations

Chelation of divalent cations (primarily Ca2+ and Mg2+) disrupts the ionic bridges that stabilize the extracellular polymeric substance (EPS) matrix, leading to biofilm dispersal and increased antibiotic penetration.