LED Photochemotherapy against Staphylococcus aureus: an in vitro study

Bacterial resistance to antibiotics is reality and need for alternative treatments is urgent. The aim of this work was to evaluate, in vitro, the effect of LED photochemotherapy on Staphylococcus aureus (ATCC 23529) using 25 mu g / mL of phenothiazine compound combined with LED light (lambda 632 +/- 2 eta m) using 12 J/cm(2) energy density. The experiments were carried out in triplicate and the samples were divided into groups: Control, Irradiated (treated only with light), Photosensitizer (treated only in the presence of the dye), LED-Photochemotherapy (treatment with light associated with dye). Counts of the colony forming units and the data obtained were statistically analyzed (ANOVA, Tukey's test, p<0.05). The present study demonstrated that the efficacy of LED-Photochemotherapy as the use of 25 mu g/mL x 12 J/cm(2) caused 91.57 % of inhibition of bacterial growth. It is concluded that using energy density of 12 J/cm(2) associated to 25 mu g/mL caused high in vitro inhibition of S. aureus.