Limitations in the clinical treatment of Staphylococcus aureus (S. aureus) infections have arisen due to the advent of antibiotic-resistant strains. Given the immense potential of therapeutic strategies targeting bacterial virulence, the role of MgrA as a pivotal virulence determinant in S. aureus-orchestrating resistance, adherence, and hundreds of virulence targets—becomes indispensable. In this investigation, leveraging advanced virtual screening and fluorescence anisotropy assays, we discerned methylophiopogonanone A (Mo-A), a flavonoid derivative, as a potent disruptor of the MgrA-DNA interaction nexus. Subsequent analysis revealed that Mo-A effectively inhibits the expression of virulence factors such as Hla and Pvl in S. aureus and markedly reduces its adhesion capability to fibrinogen. On a cellular landscape, Mo-A exerts a mitigating influence on the deleterious effects inflicted by S. aureus USA300 on A549 cells. Furthermore, our data indicate that Mo-A downregulates the transcription of genes associated with immune evasion, such as nucleases (nuc), Staphylococcal Chemotaxis Inhibitory Protein (chips), and Staphylococcal Complement Inhibitor (scin), thereby undermining immune escape and amplifying neutrophil chemotaxis. Upon application in an in vivo setting, Mo-A assumes a protective persona in a murine model of S. aureus USA300-induced pneumonia and demonstrates efficacy in the Galleria mellonella infection model. Of note, S. aureus displayed no swift acquisition of resistance to Mo-A, and the effect was synergistically enhanced when used in combination with vancomycin. Our findings add substantive weight to the expanding field of virulence-targeted therapeutic strategies and set the stage for more comprehensive exploration of Mo-A potential in combating antibiotic-resistant S. aureus.

由于抗生素耐药菌株的出现，金黄色葡萄球菌（S. aureus ）感染的临床治疗受到了限制。鉴于针对细菌毒力的治疗策略具有巨大潜力，MgrA 作为金黄色葡萄球菌的关键毒力决定因素（协调耐药性、粘附性和数百个毒力目标）的作用变得不可或缺。在这项研究中，利用先进的虚拟筛选和荧光各向异性测定，我们发现甲基硫草酮 A (Mo-A)（一种类黄酮衍生物）是 MgrA-DNA 相互作用关系的有效破坏者。后续分析表明，Mo-A能有效抑制金黄色葡萄球菌Hla、Pvl等毒力因子的表达，并显着降低其对纤维蛋白原的粘附能力。在细胞景观中，Mo-A 可减轻金黄色葡萄球菌USA300 对 A549 细胞造成的有害影响。此外，我们的数据表明，Mo-A 下调与免疫逃避相关的基因的转录，例如核酸酶 (nuc)、葡萄球菌趋化抑制蛋白 (chips) 和葡萄球菌补体抑制剂 (scin)，从而破坏免疫逃避并增强中性粒细胞趋化性。在体内应用后，Mo-A 在金黄色葡萄球菌USA300 诱导的肺炎小鼠模型中呈现出保护作用，并在大蜡螟感染模型中表现出功效。值得注意的是，金黄色葡萄球菌并没有表现出对Mo-A的快速耐药性，并且当与万古霉素联合使用时，其效果得到协同增强。我们的研究结果为不断扩大的毒力靶向治疗策略领域增添了实质性的分量，并为更全面地探索 Mo-A 在对抗抗生素耐药性金黄色葡萄球菌方面的潜力奠定了基础。