Evaluation of curcumin incubation time in Staphylococcus aureus and Pseudomonas aeruginosa Photodynamic Inactivation

This study evaluated curcumin incubation time in photodynamic inactivation with bacteria of different wall compositions: Staphylococcus aureus and Pseudomonas aeruginosa. Bacteria samples were cultured for 24h (37°C). Curcumin was dissolved in dimethylsulphoxide and subsequently diluted for final concentrations. Fluence used was 30J/cm2 (at 460nm excitation). After incubation with photosensitizer and irradiation, ten-fold serial dilutions were plated and incubated at 37°C for 48h for CFU counting. Treatment reduced approximately 7 logs of 1µM S. aureus after 30min incubation, whereas 2 logs only for P. aeruginosa at 50µM maximum concentration. Photosensitizer removed from the medium before irradiation resulted in lower reductions.