Department of Pharmacy, First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Department of Obstetrics and Gynecology, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Photodiagnosis Photodyn Ther. 2019 Mar;25:300-308. doi: 10.1016/j.pdpdt.2019.01.010. Epub 2019 Jan 8.
Antibiotic resistance has emerged as one of the most important determinants in diabetic foot infections outcomes. Antimicrobial Photodynamic therapy(A-PDT) or Photodynamic antimicrobial chemotherapy (PACT) has been proposed as an alternative approach for inactivating bacteria, especially resistant bacterial biofilms. This research investigated the synergistic effects of PACT mediated by the photosensitizer indocyanine green (ICG) and ethylenediamine tetraacetate (EDTA) combined with antibiotics against common pathogens of diabetic foot ulcer infection, including Staphylococcus aureus and Pseudomonas aeruginosa, in vitro.
Planktonic bacteria and biofilms of S. aureus and P. aeruginosa were incubated with ICG and EDTA, and then exposed to laser treatment. Quantitative viable counting estimates the phototoxic effects on S. aureus and P. aeruginosa. The susceptibility of methicillin-resistant S. aureus (MRSA) and multidrug-resistant P. aeruginosa (MRPA) to PACT treatment was detected by disk diffusion and micro-broth dilution methods. Confocal microscopy was used to detect the morphology of biofilms treated with PACT and antibiotics. The resazurin assay was used to quantify the metabolic activity of bacteria in biofilms.
PACT mediated by ICG and EDTA led to a more pronounced antibacterial effect in S. aureus and P. aeruginosa compared with ICG alone-mediated PACT. P. aeruginosa was more sensitive to ICG and EDTA-mediated PACT than S. aureus. After PACT treatment, the susceptibility of MRSA and MRPA to antibiotics increased. Furthermore, PACT combined with antibiotic treatment significantly contributed to killing bacteria in the biofilm and disrupting biofilm structure.
ICG and EDTA-mediated PACT combined with antibiotics synergistically enhanced the effects of sterilization and biofilm destruction.
抗生素耐药性已成为糖尿病足感染结果的最重要决定因素之一。光动力抗菌疗法（A-PDT）或光动力抗菌化学疗法（PACT）已被提议作为一种灭活细菌的替代方法，特别是针对耐药细菌生物膜。这项研究调查了光敏剂吲哚菁绿（ICG）和乙二胺四乙酸（EDTA）介导的 PACT 与抗生素联合治疗糖尿病足溃疡感染常见病原体（金黄色葡萄球菌和铜绿假单胞菌）的协同作用，体外。
将金黄色葡萄球菌和铜绿假单胞菌的浮游细菌和生物膜与 ICG 和 EDTA 孵育，然后进行激光处理。定量活菌计数估计 ICG 和 EDTA 介导的 PACT 对金黄色葡萄球菌和铜绿假单胞菌的光毒性作用。通过圆盘扩散和微量肉汤稀释法检测耐甲氧西林金黄色葡萄球菌（MRSA）和多药耐药铜绿假单胞菌（MRPA）对 PACT 治疗的敏感性。共聚焦显微镜用于检测用 PACT 和抗生素处理的生物膜的形态。使用 Resazurin 测定法定量生物膜中细菌的代谢活性。
与 ICG 单独介导的 PACT 相比，ICG 和 EDTA 介导的 PACT 导致金黄色葡萄球菌和铜绿假单胞菌的抗菌作用更为明显。铜绿假单胞菌对 ICG 和 EDTA 介导的 PACT 比金黄色葡萄球菌更敏感。经过 PACT 治疗后，MRSA 和 MRPA 对抗生素的敏感性增加。此外，PACT 联合抗生素治疗显著有助于杀死生物膜中的细菌并破坏生物膜结构。
ICG 和 EDTA 介导的 PACT 联合抗生素协同增强了杀菌和破坏生物膜的效果。
