Laboratory of Photobiology Applied to Health (PHOTOBIOS), Research and Development Institute (IP&D), University of Vale do Paraíba (UNIVAP), São José dos Campos, São Paulo, Brazil.
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA, CCT La Plata-CONICET), Facultad de Ciencias Exactas, Departamento de Química, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata, Argentina.
Photodiagnosis Photodyn Ther. 2022 Mar;37:102729. doi: 10.1016/j.pdpdt.2022.102729. Epub 2022 Jan 16.
Healthcare-Associated Infections (HAI) effect approximately 1.5 million individuals worldwide. Among the causes of HAIs in Latin America, Staphylococcus aureus presents a severe danger due to its rapid spread and ease of developing antibiotic resistance. Upon acquiring methicillin resistance, it receives the classification Methicillin-Resistant Staphylococcus aureus (MRSA), responsible for 40 to 60% of HAIs. The increase in resistant microorganisms led to the search for alternative methods, such as antimicrobial Photodynamic Therapy (aPDT), forming Reactive Oxygen Species (ROS), leading bacterial cells to death. The objective of this work was to evaluate in vitro the antimicrobial action of PDT with curcumin in MRSA biofilm. The strains were induced to form biofilm and incubated with curcumin for 20 min, irradiated with LED (Light Emitting Diode) 450 nm, at 110 mW/cm2, 50 J/cm2 for 455 s, subsequently counting the Colony Forming Units, Scanning Electron Microscopy (SEM) micrographs, Confocal Microscopy images, Resazurin dye test, ROS quantification to assess the effect of PDT on biofilm. The results show that PDT with curcumin reduced the biofilm growth of the MRSA strain. In addition, confocal microscopy showed that curcumin was internalized by S. aureus in the cells at the concentration used, and when isolated, curcumin and the irradiation parameter did not show cytotoxicity. The study demonstrated that the PDT in the established parameters reduced the growth of the MRSA strain biofilm, making it a relevant alternative possibility for the inactivation of this strain.
医疗保健相关感染（HAI）影响全球约 150 万人。在拉丁美洲 HAI 的病因中，金黄色葡萄球菌由于其快速传播和容易产生抗生素耐药性而构成严重威胁。获得耐甲氧西林后，它被归类为耐甲氧西林金黄色葡萄球菌（MRSA），占 HAI 的 40%至 60%。耐药微生物的增加促使人们寻找替代方法，例如抗菌光动力疗法（aPDT），形成活性氧（ROS），导致细菌细胞死亡。这项工作的目的是评估姜黄素在 MRSA 生物膜中的光动力疗法的体外抗菌作用。将菌株诱导形成生物膜，并与姜黄素孵育 20 分钟，用 450nm 的 LED（发光二极管）照射，功率密度为 110mW/cm2，50J/cm2 照射 455s，然后计算集落形成单位、扫描电子显微镜（SEM）显微照片、共聚焦显微镜图像、Resazurin 染料测试、ROS 定量以评估 PDT 对生物膜的影响。结果表明，姜黄素的 PDT 减少了 MRSA 菌株的生物膜生长。此外，共聚焦显微镜显示，姜黄素在使用的浓度下被金黄色葡萄球菌内化到细胞中，并且当分离时，姜黄素和照射参数均未显示细胞毒性。该研究表明，在既定参数下的 PDT 减少了 MRSA 菌株生物膜的生长，使其成为该菌株灭活的一种相关替代可能性。
