Virulence factors of different Candida species: reliability of microbiological methods and effect of photodynamic treatment

• Grant number: 13/16677-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: January 01, 2014
• End date: September 30, 2015
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Lívia Nordi Dovigo
• Grantee: Paula Tamião Arantes
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

The potential of Photodynamic Therapy (PDT) for inactivation of Candida species has been explored. If the exposition of Candida cells to PDT decreased the virulence of the yeast cells, then this therapy could be safely recommended. Furthermore, assessment of the accuracy of the virulence factors measurement is fundamental to reduce the introduction of biases that will certainly influence the variability of results and consequently the calculation of sample size and statistical tests power. This project contains two studies. Study I will establish a reproducible protocol of production of degradative enzymes. Standardized suspensions of C. albicans will be used and the methodology will follow published recommendations (n = 30). The dependent variables are the measurements of the ratio between the measurement of colony diameter and the diameter of the precipitation halo (Pz) for phospholipase (Pz-f) and proteinase (Pz-p) production. The independent variables will be: i. way of reading the halos of precipitation, ii. background of reading. The intra-and inter-rater Pz measures will be estimated using the Intraclass Correlation Coefficient (ICC). In Study II, in vitro tests will be performed to assess the reliability of the measurements made for other virulence factors (adhesion ability and biofilm formation) and to analyze the expression of virulence factors in C. albicans, C. glabrata, C. tropicalis and C. krusei, after PDT mediated by curcumin. Dependent variables are the colony forming units per milliliter (CFU / mL), cell metabolism (XTT), biomass (crystal violet, CV), Pz-f and Pz-p; the independent variable will be the application of PDT in two levels (with and without application). The sample size will be set after a pilot study. The intra-and inter-rater reliability (CFU/mL, XTT, and CV) will be estimated with the ICC. The dependent variables CFU/ml, XTT, and CV will be evaluated separately and mean comparison according to the independent variable will be performed with Student t test (assumptions of normality and homoscedasticity). The association of PDT (+ / -) with the expression of degradative enzymes will be assessed using the chi-square for each species of Candida. The level of significance will be set at 5%.

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)

ARANTES, PAULA TAMIAO; SANITA, PAULA VOLPATO; SANTEZI, CAROLINA; BARBEIRO, CAMILA DE OLIVEIRA; REINA, BARBARA DONADON; VERGANI, CARLOS EDUARDO; DOVIGO, LIVIA NORDI. Reliability of the agar based method to assess the production of degradative enzymes in clinical isolates of Candida albicans. Medical Mycology, v. 54, n. 3, p. 266-274, MAR 2016. (13/16677-0, 12/21251-9)

Academic Publications

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

ARANTES, Paula Tamião. Expression of virulence factors in Candida albicans: reliability of microbiological methods and effect of photodynamic treatment. 2015. Master's Dissertation - Universidade Estadual Paulista (Unesp). Faculdade de Odontologia. Araraquara Araraquara.