Mechanism of Antibacterial Activities of Cu (Ⅱ) Ions against Staphylococcus aureus and Escherichia coli on the Ground of Results Obtained from Dilution Medium Method

Antibacterial activities by copper(Ⅱ) ion solution based antibacterial results of broth dilution medium method were investigated. From dilution medium method, Minimum Inhibitory Concentration (MIC) = 625 mg/L as bacteriostatic action, Minimum Bactericide Concentration (MBC) = 1250 mg/L as bactericide action by Cu2+ ion solution were obtained against Staphylococcus aureus. Bacteriolysis of Staphylococcus aureus peptidoglycan (PGN) cell wall by Cu2+ ions is ascribed to the inhibition of PGN elongation due to the damages of PGN biosynthesis of transglycosylase (TG) and transpeptidase (TP), and the activations of PGN forth autolysins. The other, bacteriolysis of Escherichia coli outer membrane cell wall by Cu2+ ions is attributed to the destruction of outer membrane structure and to the inhibition of PGN elongation due to the damage of PGN biosynthesis TP and the activations of PGN autolysins. Cu2+ ions induced ROS such as O2 －, H2O2,･OH, OH－ producing in bacterial cell wall occur oxidative stress.