Photodynamic inhibition of Trichophyton rubrum: in vitro activity and the role of oxidative and nitrosative bursts in fungal death
Photodynamic inhibition of Trichophyton rubrum: in vitro activity and the role of oxidative and nitrosative bursts in fungal death
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DOI：
10.1093/jac/dks414
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发表时间：
2013-02-01
影响因子：
5.2
通讯作者：
Cisalpino, Patricia Silva
中科院分区：
文献类型：
--
作者：
Baltazar, Ludmila de Matos;Soares, Betania Maria;Cisalpino, Patricia Silva
抗微生物光动力抑制（API）是基于使用光源和光敏剂来杀死病原体。对皮肤癣菌的API及其作用机制知之甚少。为评价红色毛癣菌的API，以甲苯胺蓝（TBO）为光敏剂，630 nm发光二极管（LED）为光源，以12 T为靶点进行了实验。红色分离物体外API的最佳条件为TBO 10 mg/L，LED 48 J/cm 2，对不同菌株的真菌有98的杀灭或抑制作用。单独的LED或TBO处理不抑制生长。对90株菌的MIC为2.0mg/L。时间杀灭曲线分析显示，病原体死亡发生在治疗后24小时。光动力学抑制比抗真菌剂环吡酮胺更有效地促进T.红色。ROS、ONOO和NO在API的杀菌活性中起重要作用。这种活性的建议机制是TBO被LED光（630 nm）激发，与生物分子反应并增加一氧化氮合酶的过渡电子和底物的可用性，从而增加真菌细胞中的氧化和亚硝化爆发。
Antimicrobial photodynamic inhibition (aPI) is based on the use of a light source and a photosensitizer to kill pathogens. Little is known about aPI of dermatophytic fungi and its mechanism of action. We aimed to evaluate aPI of Trichophyton rubrum.We performed tests using toluidine blue (TBO) as a photosensitizer and a 630 nm light-emitting diode (LED) as a source of light to target 12 T. rubrum isolates. Susceptibility testing with cyclopiroxolamine, timekill curves and quantification of reactive oxygen species (ROS), peroxynitrite (ONOO) and nitric oxide (NO) were performed.The optimal conditions for in vitro aPI were 10 mg/L for TBO and 48 J/cm(2) for LED; these conditions were fungicidal or inhibited 98 of fungal growth depending on the strain tested. LED or TBO treatment alone did not inhibit growth. The MICs of cyclopiroxolamine were 2.0 mg/L for 90 of the strains. Analysis of timekill curves revealed that pathogen death occurred 24 h post-treatment. Quantification of ROS, ONOO and NO revealed improvement after aPI.Photodynamic inhibition was more efficient in promoting cell death than the antifungal cyclopiroxolamine against T. rubrum. ROS, ONOO and NO were important in the fungicidal activity of aPI. A suggested mechanism for this activity is that TBO is excited by LED light (630 nm), reacts with biomolecules and increases the availability of transition electrons and substrates for nitric oxide synthase, thereby increasing the oxidative and nitrosative bursts in the fungal cell.