Objective This study aimed to determine the activity of antimicrobial peptide P9-0 on pathogens that cause oral infection, and to explore preliminarily the mechanism of its antibacterial property. Methods Staphylococcus aureus(S. aureus) and Fusobacterium nucleatum(F. nucleatum), which are common pathogenic bacteria causing oral infection, were selected as the research organisms. The minimal inhibitory concentrations(MIC) of these bacteria were measured by trace dilution method. Changes in the morphology and integrity of the cell membrane of these bacteria were observed under fluorescence microscope and scanning electron microscope. Results The minimal inhibitory concentrations of P9-0 is 50 μg•mL-1 in both S. aureus and F. nucleatum. Scanning electron microscopy revealed that an apparent change in morphology occurred on the bacteria, such as edge coarsening and formation of cell membrane bubble among others. Fluorescence microscopy showed that antimicrobial peptide can lead to loss of integrity of bacterial cell membrane. Conclusion Antimicrobial peptide P9-0 effectively restrains common pathogenic bacteria such as S. aureus and F. nucleatum from causing oral infection, and the mechanism of action is possibly membrane destruction.
