In vitro influence of photodynamic antimicrobial chemotherapy on staphylococcus aureus by using phenothiazines derivatives associated with laser/LED Light
ABSTRACT The aim of this study was to evaluate the effect of photodynamic antimicrobial chemotherapy (PACT) using phenothiazinium dyes -PTZ irradiated with red laser (ʎ660nm) or red-orange LED (ʎ632±2nm) on Staphylococcus aureus in vitro. triplicate tests were performed in 10 groups: control, Laser (L1 + P -and L2 + P -) bacterial suspensions were irradiated only with laser energy 2.4 and 4.8 J/cm 2 respectively, (Led1 + P -and Led2 + P -) irradiated only with LED energy 2.4 and 4.8 J/cm 2 respectively, (L1 + P + and L2 + P + ) irradiated with laser in the presence of 1μg/ml of photosensitizer, (Led1 + P + and Led2 + P + ) irradiated with LED in the presence of 1μg/ml of photosensitizer and finally (L -P + ) only in the presence of PTZ dye. Bactericidal effect of the PACT was assessed by counting colony-forming units. The results showed no significant difference on regards different energy densities on group PACT for both lights. PACT groups (L2 + P + and Led2 + P + ) compared to the Control showed significant reduction of CFUs. LED/Laser groups (L2 + P -and Led2 + P -) compared to control and PTZ groups showed also significant differences as groups LED/Laser (4.8J/cm 2 ) increased the average of CFUs. Although the results of this study have shown a reduction in average number of colonyforming units by the appropriate Laser or LED-dye treatment combination, it this topic requires further investigation
