5-aminolevulinic acid-mediated photodynamic therapy and its strain-dependent combined effect with antibiotics on Staphylococcus aureus biofilm.

摘要: Staphylococcus aureus (S. aureus) is hard to be eradicated, not only due the emergence of antibiotic resistant strains but also because its ability form biofilm. Antibiotics are major approach treating biofilm infections, their effects unsatisfactory. One potential alternative treatments for controlling infections photodynamic therapy (PDT), which requires administration photosensitizer, followed by light activation. 5-aminolevulinic acid (ALA), a natural photosensitizer prodrug, presents favorable characteristics, such as easy penetration and rapid clearance. These advantages enable ALA-based PDT (ALA-PDT) well-tolerated patients it can repeatedly applied without cumulative toxicity or serious side effects. ALA-PDT has been proven an effective treatment multidrug pathogens; however, study effect on S. limited. Here, we established our system based utilization ALA light-emitting diode, tested well combined antibiotics Our results showed that strong antibacterial biofilm, was confirmed confocal laser scanning microscope. We found lethal photosensitization occurred predominantly in upper layer while residual live bacteria were located lower In addition, improved bactericidal observed group strain-dependent manner. suggest future clinical use treat biofilm-associated some may benefit from antibiotics, drug sensitivity testing should performed advance.