Table 2.

Summary of mechanisms of antibacterial action of antiseptics and disinfectants

TargetAntiseptic or disinfectantMechanism of action
Cell envelope (cell wall, outer membrane)GlutaraldehydeCross-linking of proteins
EDTA, other permeabilizersGram-negative bacteria: removal of Mg2+, release of some LPS
Cytoplasmic (inner) membraneQACsGeneralized membrane damage involving phospholipid bilayers
ChlorhexidineLow concentrations affect membrane integrity, high concentrations cause congealing of cytoplasm
DiaminesInduction of leakage of amino acids
PHMB, alexidinePhase separation and domain formation of membrane lipids
PhenolsLeakage; some cause uncoupling
Cross-linking of macromoleculesFormaldehydeCross-linking of proteins, RNA, and DNA
GlutaraldehydeCross-linking of proteins in cell envelope and elsewhere in the cell
DNA intercalationAcridinesIntercalation of an acridine molecule between two layers of base pairs in DNA
Interaction with thiol groupsSilver compoundsMembrane-bound enzymes (interaction with thiol groups)
Effects on DNAHalogensInhibition of DNA synthesis
Hydrogen peroxide, silver ionsDNA strand breakage
Oxidizing agentsHalogensOxidation of thiol groups to disulfides, sulfoxides, or disulfoxides
PeroxygensHydrogen peroxide: activity due to from formation of free hydroxy radicals (·OH), which oxidize thiol groups in enzymes and proteins; PAA: disruption of thiol groups in proteins and enzymes