Eficacy of antimicrobial photodynamic and sonodynamic therapies for the inactivation of candida species. In vitro and clinical study

Author(s)

Fernanda Alves

• Document type: Doctoral Thesis
• Press: Araraquara. 2018-02-06.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Odontologia. Araraquara
• Defense date: 2017-08-02
• Advisor: Ana Cláudia Pavarina

Abstract

This work evaluated the efficacy of Antimicrobial Photodynamic (aPDT) and Sonodynamics (SDT) Therapies in the inactivation of Candida species. The study 1 evaluated the efficacy of aPDT in the inactivation of susceptible and fluconazole resistant Candida albicans biofilms, as well as its effect on the virulence factors of the strains. For this, biofilms were treated with aPDT mediated by Photodithazine and LED light. After aPDT, cells were recovered and the virulence factors were evaluated. The adhesion capacity was assessed by XTT assay (metabolic activity) and CFU/mL (cell viability). The ability to form biofilm was evaluated by XTT, CFU/mL and total biomass. The synthesis of exoenzymes was evaluated by fluorimetric tests. Data were analyzed by ANOVA-2 or 3 way (p≤0.05). It was found that aPDT reduced the viability of the strains, however aPDT did not alter the virulence factors. The study 2, evaluated the effectiveness of aPDT in the treatment of patients with denture stomatitis in comparison with Nystatin (NYS). Patients of the aPDT group (n=30) underwent 6 sessions of aPDT (3 times/week, 15 days). Patients of the NYS group (n=35) rinsed the antifungal, 4 times/day, for 15 days. Microbiological collections of dentures and palates were performed and cultured on blood agar and chromagar (CFU/mL). Photographs of the palates were taken for clinical evaluation. Data were analyzed by the Linear Model of Repeated Measures (p≤0.05). It was observed that aPDT was more effective in reducing the total microbiota than NYS. The aPDT was as effective as NYS to reduce Candida spp. of the palate. aPDT and NYS showed similar clinical improvement percentage. The study 3 evaluated the efficacy of aPDT, SDT and the combination of both treatments in the inactivation C. albicans. Planktonic cultures were treated with aPDT and SDT. Cell survival was determined by CFU/mL. Biofilms were treated with aPDT, SDT and the combination of both treatments (aPDT+SDT). Efficacy in treating biofilms was evaluated by CFU/mL, total biomass and microscopy. Data were analyzed by ANOVA (p≤0.05). Although aPDT and SDT completely eradicated planktonic cultures, these treatments had no effect on biofilms. However, the combined treatment (aPDT+SDT) reduced the cell viability and total biomass (AU)

• FAPESP's process: 14/01262-1 - Clinical evaluation of the Photodynamic Therapy efficacy, mediated by Photodithazine®,in the treatment of denture stomatitis.
• Grantee: Fernanda Alves Dias de Sousa
• Support Opportunities: Scholarships in Brazil - Doctorate