Effect of polyhexamethylene biguanide functionalized silver nanoparticles on the growth of Staphylococcus aureus.

Polyhexamethylene biguanide (PHMB) was used as a stabilizing ligand to synthesize uniform silver nanoparticles (Ag NPs). The effects and action mechanism of PHMB functionalized Ag NPs (Ag NPs-PHMB) on the growth of the Gram-positive bacteria Staphylococcus aureus were investigated. The results showed that a high concentration Ag NPs-PHMB could be obtained and prepared particles were fairly uniform. Prepared Ag NPs-PHMB enhanced the bactericidal effect and the log kill reached 5.06 when S. aureus was exposed to Ag NPs-PHMB for 20 min. Ag NPs-PHMB caused damage to cell wall, a decrease in the membrane fluidity, and leakage of K+, Mg2+, ATP and proteins from the cell, eventually leading to the death of S. aureus.