Enhanced sterilization and healing of cutaneous pseudomonas infection using 5-aminolevulinic acid as a photosensitizer with 410-nm LED light

Background: Pseudomonas aeruginosa (PA) frequently develops antibiotic-resistant characteristics, which is clinically problematic. The main reason behind the rise of antibiotic-resistant PA is the extensive use of antibiotics. Therefore, a novel technique is needed to treat PA infections. Photodynamic therapy (PDT) is thought to have the potential to be a non-antibiotic treatment for infections. 5-Aminolevulinic acid (ALA), which works as a photosensitizer after being metabolized into protoporphyrin IX (PpIX) in the heme synthetic pathway, is used for PDT. Thus far, the in vivo effectiveness of PDT using ALA against PA is unknown. Objective: In this study, we investigated PDT using ALA both in vitro and in vivo. Methods and results: Although PDT with ALA alone did not show a bactericidal effect on PA, PDT with both ALA and EDTA-2Na had a bactericidal effect in vitro. In in vivo experiments, wounds healed faster in PA-infected mice treated with PDT using both EDTA-2Na and ALA compared to non-PDT. Conclusion: These results suggest that PDT with EDTA-2Na and ALA is a potential novel treatment option for PA-infected wounds. (C) 2018 Published by Elsevier B.V. on behalf of Japanese Society for Investigative Dermatology.