Abstract: The preliminary antimicrobial effects and mechanisms of PAMs against Gram-positive S. aureus were investigated. Double dilution was used to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) as well as bacteriostatic dynamics and mouse trauma infection model being conducted to illustrate the antimicrobial effects of PAMs. Also, the mechanisms were elucidated by determining the changes of electric conductivity and total soluble sugar concentration of the bacterial solution together with the observation of the super microstructure of S. aureus by scanning electron microscope. As shown ?in the results, the inhibition rate of S. aureus reached to 100% at one minute treated by PAMs, as well the MIC and MBC were 32% and 36%, respectively. Wound healing rate of S. aureus infected mouse back reached to 99.54±0.42%, significantly higher than those of the alcoholic control of 88.58±1.29% at 15 days. Changes of total soluble sugar content and relative electric conductivity in S. aureus solution treated by PAMs indicated a tendency of initiatory decrease and subsequent increase. Observation by scanning electron microscope disclosed the ruptures in the cell membranes of some S. aureus. In conclusion, PAMs can remarkably inhibit the growth of S. aureus and enhance the wound healing of mouse by increasing the permeability of bacterial cell membrane, leakage of contents, and eventually cause the death of S. aureus. As natural plant antimicrobial product, PAMs showed great potential in both scientific research and application.

Key words: Natural plant antimicrobial solution－PAMs, S. aureus－ Antimicrobial effect－ mechanism