São Paulo State University (Unesp), Department of Biosciences and Oral Diagnosis, Institute of Science and Technology, São Paulo, Brazil.
Photodiagnosis Photodyn Ther. 2018 Dec;24:95-101. doi: 10.1016/j.pdpdt.2018.07.003. Epub 2018 Jul 7.
This study evaluated the effects of photodynamic inactivation (PDI) on single and multi-species biofilms, compounds by Candida albicans and Streptococcus sanguinis. Biofilms were formed, on microplate of 96 wells, by suspensions of C. albicans (ATCC 18804) and S. sanguinis (ATCC 7073) adjusted in 10 cells/mL, followed by incubation of 48 h (with 5% CO). The effects of the photosensitizer erythrosine (ER) at 400 μM for 5 min and green light-emitting diode (LED - 532 ± 10 nm) for 3 min, alone and conjugated, were evaluated. After normality test, results was analysed by Tukey´s test (P < 0.05). PDI group promoted reductions of 1.07 and 0.39 log, respectively, in biofilms of C. albicans alone and in association with S. sanguinis. Biofilms of S. sanguinis alone were more sensitive, with reduction of 4.48 log. When in association with the yeast, S. sanguinis have a decrease of 2.67 log. SEM analysis revealed a decrease in bacterial and fungal structures of biofilms treated with PDI. In conclusion PDI promoted significant microbial reductions in both species of microorganisms grown on mixed biofilms. This study is one of the pioneers to evaluate the antimicrobial action of PDI on biofilms of S. sanguinis and C. albicans, demonstrating a way to control these microorganisms of clinical importance.
本研究评估了光动力灭活（PDI）对白色念珠菌和酿脓链球菌单种和多种生物膜的影响。通过将白色念珠菌（ATCC 18804）和酿脓链球菌（ATCC 7073）的悬浮液调整为 10 个细胞/mL，在 96 孔微量板上形成生物膜，然后在 5% CO 下孵育 48 小时。单独和共轭使用 400 μM 血卟啉衍生物（ER）5 分钟和绿光发光二极管（LED-532 ± 10 nm）3 分钟的光敏剂的效果进行了评估。在进行正态性检验后，通过 Tukey 检验（P<0.05）分析结果。PDI 组分别使白色念珠菌单独和与酿脓链球菌相关的生物膜减少了 1.07 和 0.39 log。酿脓链球菌单独的生物膜更敏感，减少了 4.48 log。当与酵母结合时，酿脓链球菌的减少量为 2.67 log。SEM 分析显示，经 PDI 处理的生物膜中细菌和真菌结构减少。综上所述，PDI 对混合生物膜中生长的两种微生物都具有显著的微生物减少作用。这项研究是评估 PDI 对酿脓链球菌和白色念珠菌生物膜的抗菌作用的先驱之一，为控制这些具有临床重要性的微生物提供了一种方法。
