Background: NH125, a known WalK inhibitor kills MRSA persisters. However, its precise mode of action is still unknown.
Methods & results: The mode of action of NH125 was investigated by comparing its spectrum of antimicrobial activity and its effects on membrane permeability and giant unilamellar vesicles (GUVs) with walrycin B, a WalR inhibitor and benzyldimethylhexadecylammonium chloride (16-BAC), a cationic surfactant. NH125 killed persister cells of a variety of Staphylococcus aureus strains. Similar to 16-BAC, NH125 killed MRSA persisters by inducing rapid membrane permeabilization and caused the rupture of GUVs, whereas walrycin B did not kill MRSA persisters or induce membrane permeabilization and did not affect GUVs.
Conclusion: NH125 kills MRSA persisters by interacting with and disrupting membranes in a detergent-like manner.
Keywords: MRSA; NH125; antibiotics; giant unilamellar vesicle; two-component system.