Anti-biofilm and Antibacterial Effect of Psoralen Plus Ultraviolet-A (PUVA) Treatment Against Staphylococcus Aureus Isolated from Tatients Wounds

Background and Objective: Staphylococcus aureus is a major pathogen associated with wound infections, and the formation of biofilms by this bacterium poses significant challenges to successful treatment. Biofilms not only protect bacteria from antibiotics but also contribute to chronicity and recurrence of infections. Therefore, novel strategies are urgently required to prevent biofilm formation. This study aimed to investigate the potential of phototherapy with psoralen-ultraviolet A (PUVA) as a new treatment method for preventing biofilm formation in S. aureus samples isolated from patients' wounds.Material and Methods: A total of ۳۰ wound specimens were collected from patients diagnosed with S.aureus infections. The isolates were phenotypically confirmed using standard microbiological techniques. Biofilm-forming ability was assessed using crystal violet staining and microtiter plate assays. PUVA treatment involved exposing the bacterial isolates to a combination of ۸-methoxypsoralen(۸-MOP) and ultraviolet A radiation at specific wavelengths and doses. Control groups consisting of untreated bacteria and bacteria treated with either psoralen or ultraviolet A alone were included for comparison.Results and Discussion: PUVA treatment significantly inhibited biofilm formation and bacterial growth ability of S. aureus strain when the UVA dose was ۱۰۰۰ mj/cm۲ and the ۸-MOP concentration was ۵۰ µg/ml or more. However, when the UVA dose decreased to ۵۰۰ mj/cm۲, inhibition of biofilm formation started from ۸-MOP concentration of ۷۵ µg/ml.Conclusion: PUVA treatment has been found to significantly reduce biofilm formation in a dose-dependent manner in S. aureus. The optimal conditions for inhibiting biofilm formation were a ۷۵ µg/ml concentration of ۸-MOP and a ۵۰۰ mj/cm۲ UVA dose. Further research is needed to explore the mechanisms underlying the inhibitory effects of PUVA treatment and to evaluate its potential clinical applications in preventing biofilm formation and improving the management of S. aureus infections