The molecular mechanism of action of bactericidal gold nanoparticles on Escherichia coli

This work examines the molecular mechanism of action of a class of bactericidal gold nanoparticles (NPs) which show potent antibacterial activities against multidrug-resistant Gram-negative bacteria by transcriptomic and proteomic approaches. Gold NPs exert their antibacterial activities mainly by two ways: one is to collapse membrane potential, inhibiting ATPase activities to decrease the ATP level; the other is to inhibit the subunit of ribosome from binding tRNA. Gold NPs enhance chemotaxis in the early-phase reaction. The action of gold NPs did not include reactive oxygen species (ROS)-related mechanism, the cause for cellular death induced by most bactericidal antibiotics and nanomaterials. Our investigation would allow the development of antibacterial agents that target the energy-metabolism and transcription of bacteria without triggering the ROS reaction, which may be at the same time harmful for the host when killing bacteria. (C) 2011 Elsevier Ltd. All rights reserved.