ADHERENCE REDUCTION OF PSEUDOMONAS AERUGINOSA UFPEDA 416 UNDER BLUE LED LIGHT IRRADIATION AND CURCUMIN EXPOSURE

Abstract

This study assessed the adhesion of Pseudomonas aeruginosa UFPEDA 416 (ATCC 27853) exposed to curcumin-mediated Photodynamic Antimicrobial Chemotherapy (PACT). Initially, the Minimum Inhibitory Concentration of curcumin was determined (0.63 μg/mL). After, P. aeruginosa UFPEDA 416 was exposed to the MIC solution of curcumin and then irradiated with a high-power blue LED light at 480 nm for 20, 40, 60 and 120 minutes (28.03 mW/cm2). At each interval, 100 µL aliquots were transferred to microtubes containing Müeller-Hinton broth and incubated at 30ºC for 24 h. The biofilm formed was quantified by the crystal violet method. The adherence rate was calculated using the difference in the absorbance of the treatment, compared to the control. There was a reduction in adhesion capacity from 40.8% in the first 20 minutes to approximately 11% after 60 minutes. The reduction in the adhesion rate accompanied the decrease in planktonic cells, determined from the measurement of the absorbance of the supernatant at 620 nm. The results indicated action by bacteriostasis.