National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, The Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, The Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, 710119, People's Republic of China.
National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, The Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, The Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, 710119, People's Republic of China.
Photodiagnosis Photodyn Ther. 2019 Dec;28:80-87. doi: 10.1016/j.pdpdt.2019.08.031. Epub 2019 Aug 27.
Antibacterial photodynamic therapy (aPDT) has been proposed as an alternative strategy to inactivate bacteria. This study was designed to investigate the antibacterial effect of a novel photosensitizer S-Porphin sodium (S-PS) on plankton and biofilm cultures of Staphylococcus aureus (S. aureus) and its multiple drug resistance strain S. aureus (MDR S. aureus).
The plate counting method was used to evaluate the antimicrobial effect of S-PS-aPDT. The bacterial viability was detected by SYTO9/PI. The intracellular reactive oxygen species (ROS) generation was estimated by electron spin resonance spectroscopy and flow cytometry. The destruction of bacteria and biofilm was observed by scanning electron microscope (SEM) and atomic force microscope (AFM), respectively.
The aPDT induced antibacterial effect in S. aureus and MDR S. aureus was S-PS concentration- and light dose-dependent. S. aureus exhibited much higher sensitivity to aPDT than MDR S. aureus, regarding to cell killing, ROS level, as well as morphological damages under AFM observation. When pretreated with the efflux pump inhibitors (EPIs), the intracellular uptake of S-PS in MDR S. aureus increased and the coupled aPDT produced significantly enhanced antibacterial efficiency.
S-PS-aPDT exhibited excellent bactericidal activity in plankton and biofilms. S-PS might be a good candidate for using in PDT anti-bacterial field. The introduction of EPIs could effectively improve the killing effect of MDR S. aureus.
抗菌光动力疗法（aPDT）已被提出作为一种替代策略来灭活细菌。本研究旨在研究新型光敏剂 S-卟啉钠（S-PS）对金黄色葡萄球菌（S. aureus）及其多药耐药株金黄色葡萄球菌（MDR S. aureus）浮游和生物膜培养物的抗菌作用。
平板计数法评估 S-PS-aPDT 的抗菌效果。通过 SYTO9/PI 检测细菌活力。通过电子自旋共振光谱和流式细胞术估计细胞内活性氧（ROS）的产生。通过扫描电子显微镜（SEM）和原子力显微镜（AFM）分别观察细菌和生物膜的破坏情况。
aPDT 诱导 S. aureus 和 MDR S. aureus 的抗菌作用是 S-PS 浓度和光剂量依赖性的。与细胞杀伤、ROS 水平以及 AFM 观察下的形态损伤相比，S. aureus 对 aPDT 的敏感性明显高于 MDR S. aureus。当用外排泵抑制剂（EPIs）预处理时，MDR S. aureus 中的 S-PS 细胞内摄取增加，联合 aPDT 产生的抗菌效率显著增强。
S-PS-aPDT 在浮游和生物膜中表现出优异的杀菌活性。S-PS 可能是 PDT 抗菌领域的良好候选药物。引入 EPIs 可以有效提高 MDR S. aureus 的杀伤效果。
