Evaluation of the efficacy of DNase associated with photodynamic therapy against fluconazole resistant Candida albicans biofilm

• Grant number: 19/11602-8
• Support Opportunities: Scholarships in Brazil - Master
• Start date: September 01, 2019
• End date: April 30, 2021
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Principal Investigator: Ana Cláudia Pavarina
• Grantee: César Augusto Abreu Pereira
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
• Associated research grant: 13/07276-1 - CEPOF - Optics and Photonic Research Center, AP.CEPID

Abstract

Studies have shown that antimicrobial photodynamic therapy (aPDT) promotes complete inactivation of microorganisms in suspension, however, the complete inactivation of biofilms has not yet been observed. The resistance of Candida spp. biofilm is multifactorial and has been associated with factors such as the protective effect of the extracellular matrix of biofilm (MEC) performed by ²-glucans, which bind to fluconazole and amphotericin B, preventing the drugs penetration into the biofilm. The MEC biofilm also hinders the photosensitizing penetration agent and other drugs. Another important aspect is that Candida species resistant to fluconazole have also been shown to be more resistant to aPDT. Based on that, this study aims to evaluate the efficacy of DNase enzyme associated with aPDT on biofilms of clinical isolates of Candida albicans resistant to fluconazole. Biofilms will be formed from resistant strains of C. albicans [ATCC 96901, and two clinical isolates (R10 and R15)]. After 48 h of biofilm formation these strains were will be treated with DNase and then exposed to aPDT (incubated with Photodithazine® for 20 min and exposed to LED light (660 nm, 37.5 J/cm2). The following methods will be used to evaluate the treatments effectiveness: colony-forming unit (CFU)/mL, dry weight analysis, protein quantification by Bradford method, analysis of water-soluble polysaccharides (WSP), analysis of alkali soluble polysaccharides (ASP) and analysis of eDNA. Besides that, the biofilm structure will be evaluated through Confocal Laser Microscopy. The data obtained will be submitted to the most adequate statistical analysis for each experimental condition. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ABREU-PEREIRA, CESAR AUGUSTO; KLEIN, MARLISE INEZ; LOBO, CARMELIA ISABEL VITORINO; GORAYB PEREIRA, ANA LUIZA; JORDAO, CLAUDIA CAROLINA; PAVARINA, ANA CLAUDIA. DNase enhances photodynamic therapy against fluconazole-resistant Candida albicans biofilms. ORAL DISEASES, v. N/A, p. 13-pg., 2022-02-19. (19/11602-8, 14/50857-8, 13/07276-1)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

PEREIRA, César Augusto Abreu. Evaluation of the effectiveness of Dnase associated with photodynamic therapy in inactivating biofilms from clinical isolates of Candida albicans resistant to fluconazole. 2021. Master's Dissertation - Universidade Estadual Paulista (Unesp). Faculdade de Odontologia. Araraquara Araraquara.