The development of antimicrobial agents with novel model of actions is a promising strategy to combat multiple resistant bacteria. Here, three ruthenium-based complexes, which acted as potential antimicrobial agents, were synthesized and characterized. Importantly, three complexes all showed strong bactericidal potency against Staphylococcus aureus. In particular, the most active one has a MIC of 6.25 μg/mL. Mechanistic studies indicated that ruthenium complex killed S. aureus by releasing ROS and damaging the integrity of bacterial cell membrane. In addition, the most active complex not only could inhibit the biofilm formation and hemolytic toxin secretion of S. aureus, but also serve as a potential antimicrobial adjuvant as well, which showed synergistic effects with eight traditional antibiotics. Finally, both G. mellonella larva infection model and mouse skin infection model all demonstrated that ruthenium complex also showed significant efficacy against S. aureus in vivo. In summary, our study suggested that ruthenium-based complexes bearing a phenyl hydroxide are promising antimicrobial agents for combating S. aureus.
Keywords: Antibacterial mechanism; Reactive oxygen species; S. aureus; Synergistic effect.
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