Laboratório de Terapia Fotodinâmica, Instituto de Pesquisa e Desenvolvimento (IP&D), Universidade do Vale do Paraíba, São José dos Campos, SP, Brazil.
Laboratório de Dinâmica de Compartimentos Celulares, Instituto de Pesquisa e Desenvolvimento (IP&D), Universidade do Vale do Paraíba, São José dos Campos, SP, Brazil.
Photodiagnosis Photodyn Ther. 2018 Jun;22:43-50. doi: 10.1016/j.pdpdt.2018.02.008. Epub 2018 Feb 15.
Bacterial infections have been a major challenge to health. Increasing resistance to antimicrobial agents, according to World Health Organization, could be the major cause of death until 2050. Photodynamic therapy emerges as an alternative in microbial inactivation, due to its selectivity and to decreasing or dismissing antibiotic use. This study aimed at evaluating, in vitro, the internalization of the Methylene Blue and its photodynamic activity against a clinical and ATCC strain of Pseudomonas aeruginosa and Staphyloccocus aureus. Thus, the strains were incubated with MB in concentrations of 100, 300 e 500 μg/ml and then irradiated with a LED (±660 nm) at fluence of 10 and 25 J/cm. The MB internalization was evaluated using a confocal microscope (Zeiss LSM 700), to capture the MB and the DAPI (for DNA staining). It was possible to observe that the MB was internalized by the bacterial cells, in all concentrations tested. The CFU/ml count demonstrated significant reduction (p ≤ 0,01) at the average 5.0 logs comparing with control group for the two species in all the tested concentrations. In conclusion, the strains tested were capable of internalizing the MB. PDT with MB was able to decrease the growth of the tested strains in vitro, being a promising alternative to the future treatment of infections caused by these species.
细菌感染一直是健康的主要挑战。根据世界卫生组织的数据，到 2050 年，对抗生素的耐药性增加可能成为主要死因。光动力疗法因其选择性以及减少或避免使用抗生素而成为微生物失活的一种替代方法。本研究旨在评估亚甲蓝（Methylene Blue）的体内摄取及其对临床和 ATCC 铜绿假单胞菌和金黄色葡萄球菌的光动力活性。因此，将菌株在浓度为 100、300 和 500μg/ml 的 MB 中孵育，然后用 LED（±660nm）在 10 和 25J/cm 的辐照下照射。使用共聚焦显微镜（Zeiss LSM 700）评估 MB 的内化，以捕获 MB 和 DAPI（用于 DNA 染色）。可以观察到 MB 被细菌细胞内化，在所有测试浓度下均如此。CFU/ml 计数显示，与对照组相比，两种细菌在所有测试浓度下的平均 5.0 个对数级均有显著减少（p≤0.01）。总之，测试的菌株能够内化 MB。MB 的 PDT 能够在体外减少测试菌株的生长，是未来治疗这些物种引起的感染的有前途的替代方法。
