Action of photodynamic inactivation in antibiotic failures

The increase in the number of microorganisms resistant to antimicrobials motivates the search for strategies that recover the use of traditional antibiotics. Photodynamic Inactivation (PDI) is an alternative to antibiotics because the combination of a photosensitizer with light leads to the production of reactive oxygen species that promote the elimination of undesirable cells. Curcumin and light at 450 nm are applied at regular intervals and new values of minimum inhibitory concentration of antibiotics are obtained. We demonstrated that the application of PDI reduces the necessary dosage of antibiotics for the elimination of the bacterial cell, proving to be an efficient strategy for application in resistant strains. Furthermore, we verified that the interaction of the photosensitizer with the antibiotics promotes alterations in the metabolism and the bacterial biomolecules. These results are essential to transfer in vitro studies to the clinical implementation of DIF as an adjuvant to antibiotic therapy.