Susceptibility of Staphylococcus aureus to porphyrin-mediated photodynamic antimicrobial chemotherapy: an in vitro study
Susceptibility of Staphylococcus aureus to porphyrin-mediated photodynamic antimicrobial chemotherapy: an in vitro study
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DOI：
10.1007/s10103-009-0705-0
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发表时间：
2010-05-01
影响因子：
2.1
通讯作者：
Bagnato, Vanderlei Salvador
中科院分区：
文献类型：
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作者：
Gois, Mariana M.;Kurachi, Christina;Bagnato, Vanderlei Salvador
金黄色葡萄球菌产生多重耐药性的能力已得到充分证明，并且越来越多的细菌表现出的抗生素耐药性表明需要替代疗法来治疗感染，光动力疗法（PDT）是一种潜在的候选疗法。本研究的目的是确定光动力疗法作为一种基于光的杀菌方式消除金黄色葡萄球菌的效果。该研究研究了一种基于光和光敏剂组合的技术，该技术能够产生氧化物质以诱导细胞毒性作用。将金黄色葡萄球菌悬浮液暴露于发光二极管 (LED) 下，在不同浓度的卟啉存在下 (PhotogemA (R))，发光二极管 (LED) 的发射波长为 628 nm、14.6 mW/cm(2)，能量密度为 20J/cm(2)、40J/cm(2) 或 60 J/cm(2)。使用三种药物浓度：12μl/ml、25μl/ml和50μl/ml。通过光暴露后的细菌菌落形成单位（CFU）的数量来评估治疗反应。结果表明，平均而言，暴露于 60 J/cm(2) 下可以消除 100%（10 log(10) 尺度）的细菌。通过暴露于 LED 光并结合浓度范围为 25 μl/ml 至 50 μl/ml 的光敏剂，实现了消除金黄色葡萄球菌的最佳 PDT 响应率。这些数据表明PDT具有消除悬浮液中金黄色葡萄球菌的潜力，并表明了必要的药物浓度和光流畅度。
The ability of Staphylococcus aureus to develop multidrug resistance is well documented, and the antibiotic resistance showed by an increasing number of bacteria has shown the need for alternative therapies to treat infections, photodynamic therapy (PDT) being a potential candidate. The aim of this study was to determine the effect of photodynamic therapy as a light-based bactericidal modality to eliminate Staphylococcus aureus. The study investigated a technique based on a combination of light and a photosensitizer that is capable of producing oxidative species to induce a cytotoxic effect. A Staphylococcus aureus suspension was exposed to a light emitting diode (LED) emitting at 628 nm, 14.6 mW/cm(2), and energy density of 20J/cm(2), 40J/cm(2), or 60 J/cm(2) in the presence of different porphyrin concentrations (PhotogemA (R)). Three drug concentrations were employed: 12 mu l/ml, 25 mu l/ml, and 50 mu l/ml. The treatment response was evaluated by the number of bacterial colony forming units (CFU) after light exposure. The results indicated that exposure to 60 J/cm(2) eliminated 100% (10 log(10) scales) of bacteria, on average. The best PDT response rate to eliminate Staphylococcus aureus was achieved with exposure to LED light in combination with the photosensitizer at concentrations ranging from 25 mu l/ml to 50 mu l/ml. These data suggest that PDT has the potential to eliminate Staphylococcus aureus in suspension and indicates the necessary drug concentration and light fluency.