抗菌蓝光(aBL)被用作抑制金黄色葡萄球菌生长的新方法(S.金黄色葡萄球菌)。由内源性发色团介导,aBL具有与aPDI(抗微生物光动力灭活)相似的光杀伤特性,然而,它们在引发葡萄球菌细胞死亡方面的机制差异尚不清楚.这里,我们描述了使用460nm-LED抑制金黄色葡萄球菌的生存力.根据结果,当使用蓝光时,细菌的存活率急剧下降,达到最大4.11±0.04log10单位。此外,膜完整性被aBL破坏,导致细胞内DNA的泄漏.转录组分析表明aBL或aPDI时基因表达不同,通过运输等途径,DNA修复,aBL对表达调控和卟啉的影响很大。在普遍调控的基因中,LrgA的基础是其参与生物膜形成和蛋白质转运。通过比较野生型与LrgA过表达(LrgA+)菌株,存活率,膜渗透,表面结构和生物膜的形成,在不同程度上,对LrgA+进行了改进,这可能表明LrgA在调节金黄色葡萄球菌的反应性中起着至关重要的作用。此外,LrgA可能通过调节自溶相关系统的表达来发挥作用。最后,LrgA过表达不会减弱但会加重aPDI诱导的损伤,展示了来自aBL的独特响应策略。一起来看,这项研究揭示了aBL介导的失活的独特分子改变,为利用蓝光减少金黄色葡萄球菌带来的危害提供了依据。
Antimicrobial blue light (aBL) is utilized as a new approach to inhibit the growth of Staphylococcus aureus (S. aureus). Mediated by the endogenous chromophore, aBL possesses the similar photokilling property with aPDI (antimicrobial photodynamic inactivation), however, their mechanistic discrepancies in triggering the death of staphylococcal cells are not yet understood. Here, we describe the use of a 460-nm-LED to curb the viability of S. aureus. According to the results, the bacterial survival was sharply decreased when blue light was applied, reaching a maximum of 4.11 ± 0.04 log10 units. Moreover, the membrane integrity was damaged by aBL, causing the leakage of intracellular DNA. Transcriptomic analysis indicates the divergent gene expression upon either aBL or aPDI, with pathways such as transport, DNA repair, expression regulation and porphyrin massively affected by aBL. Among the commonly regulated genes, LrgA was underpinned on account of its involvement with biofilm formation and protein transport. By comparing the wildtype with the LrgA-overexpressing (LrgA+) strain, the survival rate, membrane penetration, surface structure and biofilm formation were, to a varying degree, improved for LrgA+, which may suggest that LrgA plays essential roles in modulating the responsiveness of S. aureus. Besides, LrgA may function through regulating the expression of autolysis-related systems. Finally, LrgA overexpression did not attenuate but aggravate the impairment induced by aPDI, showcasing a distinct responsive strategy from aBL. Taken together, this study unveils a unique molecular alteration for the aBL-mediated inactivation, providing the basis of utilizing blue light to reduce the harm brought by S. aureus.