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Updated: Apr 15, 2026
An In Vitro Model to Study the Effect of 5-Aminolevulinic Acid-mediated Photodynamic Therapy on Staphylococcus aureus Biofilm
Published on: April 16, 2018
Antimicrobial photodynamic activity of hypericin against methicillin-susceptible and resistant Staphylococcus aureus
Isabel García1, Sofía Ballesta, Yolanda Gilaberte
1Department of Microbiology, School of Medicine, Universidad de Sevilla, Sevilla, Spain.
Aim:
To evaluate the effectiveness of the photodynamic therapy using hypericin (HYP) against both planktonic and biofilm-forming Staphylococcus aureus.
Materials & Methods:
HYP photoactivity was evaluated against methicillin-susceptible and resistant S. aureus. Bacterial suspension or biofilm were preincubated with HYP and subjected to LED illumination. Viable bacteria were determined by colony counting.
Results:
Preincubation with HYP (5 min) plus light exposure (10 min) showed bactericidal effect against planktonic methicillin-susceptible S. aureus and methicillin-resistant S. aureus. Longer preincubation times (24 h) and time light exposure (30 min) were required to reach HYP-photoactivity against S. aureus biofilms. HYP-photoactivity was correlated to the biofilm production.
Conclusion:
HYP could be a potential photosensitizer for the inactivation of staphylococcal biofilms forming on the surfaces accessible to visible light.
