Lu Min, Wong Ka Ioi, Li Xin, Wang Fei, Wei Li, Wang Shen, Wu Mei X
Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Department of Orthopaedics, Ruijin Hospital, Shanghai Institute of Traumatology and Orthopaedics, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Front Microbiol. 2022 Mar 10;13:810746. doi: 10.3389/fmicb.2022.810746. eCollection 2022.
Blue light (BL) at 405 nm and oregano essential oil (OEO) have shown bactericidal activity by its own. Here, we demonstrated that the two synergistically killed multidrug-resistant (MDR) (). ATCC19660 and HS0065 planktonic cells and mature biofilms were reduced by more than 7 log after treatment by BL combined with OEO, in sharp contrast to no significant bacterial reduction with the monotreatment. The duo also sufficiently eliminated acute or biofilm-associated infection of open burn wounds in murine without incurring any harmful events in the skin. The synergic bactericide was attributed mainly to the ability of OEO to magnify cytotoxic reactive oxygen species (ROS) production initiated by BL that excited endogenous tetrapyrrole macrocycles in bacteria while completely sparing the surrounding tissues from the phototoxic action. OEO ingredient analysis in combination with microbial assays identified carvacrol and its isomer thymol to be the major phytochemicals that cooperated with BL executing synergic killing. The finding argues persuasively for valuable references of carvacrol and thymol in assessing and standardizing the bactericidal potential of various OEO products.
405纳米的蓝光（BL）和牛至精油（OEO）自身已显示出杀菌活性。在此，我们证明了二者协同作用可杀死多重耐药（MDR）（）。与单一处理无明显细菌减少形成鲜明对比的是，用BL联合OEO处理后，ATCC19660和HS0065浮游细胞以及成熟生物被膜减少了7个对数以上。二者组合还充分消除了小鼠开放性烧伤创面的急性或生物被膜相关感染，且未在皮肤中引发任何有害事件。这种协同杀菌剂主要归因于OEO放大由BL引发的细胞毒性活性氧（ROS）产生的能力，BL激发细菌内源性四吡咯大环，同时使周围组织完全免受光毒性作用。结合微生物分析的OEO成分分析确定香芹酚及其异构体百里香酚是与BL协同执行杀菌作用的主要植物化学物质。这一发现有力地证明了香芹酚和百里香酚在评估和规范各种OEO产品杀菌潜力方面具有重要参考价值。
