5-aminolevulinic acid-photodynamic therapy ameliorates cutaneous granuloma by killing drug-resistant Mycobacterium marinum

Abstract

Although 5-aminolevulinic acid photodynamic therapy (ALA-PDT) has been extensively used to treat to various skin disease, the application of ALA-PDT on cutaneous infection caused by Mycobacterium marinum (M. marinum), especially by drug-resistant M. marinum is still not clear. We evaluated the therapeutic efficacy of ALA-PDT on M. marinum in a mouse infection model and tested its killing effect on M. marinumin vitro. Finally, we investigated the clinical effect of ALA-PDT in treating cutaneous granuloma caused by drug-resistant M. marinum. We isolated total 9 strains of M. marinum from patients and confirmed by morphological and molecular approaches. The strains were identified by anti-mycobacterial susceptibility. Then we evaluated the killing effect of ALA-PDT on M. marinum in vitro and in a mouse model to observe the antimycobacterial effect of ALA-PDT. Therapeutic efficacy was further assessed in patients with cutaneous granuloma caused by drug-resistant M. marinum. We demonstrated that the ALA-PDT directly killed M. marinumin vitro. The paws cutaneous lesions of mice caused by M. marinum were fully recovered 2 weeks after ALA-PDT treatment. However, there was no significant difference for immune cells in peripheral blood before and after ALA-PDT therapy. Finally, ALA-PDT proved to be effective in treat two patients with cutaneous infection caused by drug-resistant M. marinum. The results suggest that ALA-PDT is effective in treating M. marinum cutaneous infections by killing M. marinum directly, independent of systemic immune responses. The data highlight the ALA-PDT as a promising therapeutic choice for M. marinum infection, especially for drug-resistant strains.

ALA_PDT Promotes Ferroptosis-Like Death of Mycobacterium abscessus and Antibiotic Sterilization via Oxidative Stress

“…ALA_PDT is safe and easy to implement, and effective against bacteria [52], fungi [53], viruses [54,55] and protozoa [56,57]. Compared with conventional antibiotics, ALA_PDT acts rapidly and can even sterilize drug resistant strains [58,59]. This broad-spectrum effect might have an important role in the treatment of emerging infectious diseases.…”