Evaluation of antimicrobial photodynamic therapy application for control and treatment of infections involving Candida spp. and Staphylococcus aureus

Author(s)

Elis Rodrigues Oliveira Barbosa

• Document type: Master's Dissertation
• Press: Araraquara. 2023-04-11.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Odontologia. Araraquara
• Defense date: 2023-03-03
• Advisor: Fernanda Lourenção Brighenti

Abstract

This Dissertation was divided into two publications that aimed: a) to perform a systematic literature review and meta-analysis on the clinical application and efficacy of aPDT in the treatment of oral infections involving Candida spp. and b) to evaluate the in vitro potential of Senna spp. as photosensitizer in aPDT on single- and dual species biofilms of Candida albicans and Staphylococcus aureus. Publication 1: Electronic searches were performed seeking for randomized clinical trials that evaluated the effect of aPDT as a treatment for oral infections involving Candida spp. The review followed the PRISMA protocol, and the selected studies were synthesized qualitatively and quantitatively. The level of evidence and the risk of bias of each study were assessed. A network meta-analysis was performed considering the reduction of microbial counting on palate and prosthetic surface. Most studies investigated the effect of aPDT on denture stomatitis. C. albicans was the most prevalent species. All included studies were classified as Level 2 of Evidence and had bias risk regarding missing outcome data. Four articles were included in the network meta-analysis. On the palate, all treatments were effective when compared to the control group. aPDT and aPDT+nystatin were similarly effective, while nystatin or miconazole were more effective than aPDT. aPDT was also effective to prosthesis surfaces disinfection. The results suggest that aPDT application represents an effective approach for the treatment of oral infections involving Candida spp. Publication 2: Crude extracts of Senna macranthera (SM) and Senna splendida (SS) were fractionated by the chromatographic method. The fractions had the light absorption spectrum checked and were chemically characterized. Single- and dualspecies biofilms of C. albicans and S. aureus were cultured for 48 h. The following groups were tested: negative control (NC), fractions without light (SM1-, SM2-, SS1-, SS2-), light control (LC), vehicle control with or without light (DMSO 1%; VC+, VC-, respectively) and fractions with irradiation (aPDT: SM1+, SM2+, SS1+, SS2+). Each fraction (0.2 mg/ml) was applied to the fractions without irradiation and aPDT groups and pre-incubated for 15 min (single-species biofilm) or 20 min (dual-species biofilm). The VC+, LC and aPDT groups were irradiated at 450 nm and 139.5 J/cm2 for 900 s in fractionated mode. Data were analyzed using IBM SPSS 20.0 (α=0.05) and R (CI=95%) programs. From the 12 fractions obtained, four showed light absorption between 400 and 450 nm and were selected for the study. Phytochemical characterization showed the presence of anthraquinones class. In aPDT groups, all fractions reduced microbial viability in single- and dual species biofilms. In the presence of light, a greater microbial reduction was observed in dual-species biofilms. Only the SM1 fraction led to > 3 log CFU/mL reduction in all biofilms. aPDT mediated by fractions of Senna spp. demonstrated in vitro potential for the reduction of single- and dual species biofilms of S. aureus and C. albicans. (AU)

• FAPESP's process: 20/16330-3 - Senna spp. extracts fractionation: phytochemical study and evaluation as photosensitizers on Candida albicans and Staphylococcus aureus monotypic and heterotypic biofilms
• Grantee: Elis Rodrigues Oliveira Barbosa
• Support Opportunities: Scholarships in Brazil - Master