近日，美国麻省总医院和哈佛医学院的研究人员发现，蓝光能够选择性根除皮肤和软组织中的绿脓杆菌感染，同时不会对外层皮肤造成损伤。相关论文在线发表于美国微生物学会会刊《抗菌剂与化疗》杂志上。
负责该研究的迈克尔·汉布林表示，在治疗皮肤和软组织感染方面，蓝光是一种潜在的无毒、非抗生素疗法，特别是对那些由抗生素耐药菌引起的感染更为有效。
在这项研究中，研究人员在被绿脓杆菌感染的动物模型上进行了实验，结果显示：所有经过蓝光治疗的动物均存活了下来，而在未经过蓝光治疗的对照组中，82%（11只中的9只）的动物死亡。
许多病菌具有极强的复制能力，为应对抗生素，它们会快速发生突变，并在整个微生物种群中占据主导地位。最近一种名为DM-1的超级病菌便是一个例子，这种病菌具有极强的耐药性，目前，除替加环素、黏菌素和万古霉素这三种抗生素外，其他抗生素对这类细菌均无杀灭作用。抗生素耐药性的大暴发正在让治疗此类感染变得愈发复杂，许多医生甚至认为一些感染在不久之后将变得无法治愈。
除了危害公众健康，抗生素耐药性的提高还进一步增加了医疗成本。治疗软组织和皮肤感染，往往需要使用更贵的药物，这可能会导致受感染的病人延长住院时间。皮肤和软组织感染是临床实践中遇到的第二种最常见的细菌感染。在美国，因皮肤及软组织感染而住院的患者大约占患者总数的10%，加上大约14.2万的门诊患者，每年需支出医疗费用240亿美元，平均在每个美国人身上高达76美元。
Blue light rescues mice from potentially fatal Pseudomonas aeruginosa burn infection: efficacy, safety, and mechanism of action
Tianhong Dai, Asheesh Gupta, Ying-Ying Huang, Rui Yin, Clinton K. Murray, Mark S. Vrahas, Margaret Sherwood, George P Tegos and Michael R. Hamblin
Blue light has attracted increasing attention due to its intrinsic antimicrobial effect without the addition of exogenous photosensitizers. However, the use of blue light for wound infections has not been established yet. In this study, we demonstrated the efficacy of blue light at 415 nm for treatment of acute, potentially lethal Pseudomonas aeruginosa burn infections in mice. In vitro studies demonstrated that the inactivation rate of P. aeruginosa cells by blue light was approximately 35-fold faster than that of keratinocytes (P=0.0014). Transmission electron microscopy revealed blue light mediated intracellular damage to P. aeruginosa cells. Fluorescence spectroscopy suggested that coproporphyrin III or/and uroporphyrin III are possibly the intracellular photosensitive chromophores associated with the blue light inactivation of P. aeruginosa. In vivo studies using an in vivo bioluminescence imaging technique and the area-under-the-bioluminescence-time-curve (AUBC) analysis showed that a single exposure of blue light at 55.8 J/cm2, applied 30 min after bacterial inoculation to the infected mouse burns, reduced the AUBC by an approximately 100-fold in comparison with untreated and infected mouse burns (P<0.0001). Histological analysis and TUNEL assay indicated no significant damages in the mouse skin exposed to blue light at the effective antimicrobial dose. Survival analysis revealed that blue light increased the survival rate of infected mice from 18.2% to 100% (P<0.0001). In conclusion, blue light therapy may offer an effective and safe alternative to conventional antimicrobial therapy for P. aeruginosa burn infections.
