Insights into Metallic Ag+, Cu2+, Zn2+ Ions-Induced Bacteriolytic Mechanism against S. Aureus and E. Coli

Abstract

Metallic Ag+, Cu2+, Zn2+ ions, respectively, induced bacteriolytic mechanism has been elucidated against S. aureus and E. coli. Bacteriolytic mechanism for Ag+, Cu2+, Zn2+ ions, respectively, induced S. aureus is clarified that bacteriolysis and destruction of S. aureus PGN cell wall occur by inhibition of PGN elongation through metallic Ag+, Cu2+, Zn2+ ions-induced PGN inhibitory transglycosylase (TG) and transpeptidase (TP) syntheses (TG for Zn2+) and PGN activated major autolysin of amidase. The other, bacteriolytic mechanism for Ag+, Cu2+, Zn2+ ions, respectively, induced E. coli is found that bacteriolysis and destruction of E. coli cell wall occur by disruption of E. coli outer membrane (OM) structure with OM lipoprotein-endopeptidase activation, and by inhibition of PGN elongation through inhibitory TG and TP syntheses (TG for Zn2+) and PGN activated major autolysins. Ag+, Cu2+, Zn2+ ions-induced ROS generation of O2- and H2 O2 and ROS-mediated oxidative stress in bacterial cell lead to killing by stress damage for silver ions, cell membrane damages due to high reactive •OH and OH－ are formed by Haber-Weiss and Fenton reactions for Cu2+ ions, and DNA molecular damage for Zn2+ ions.