Effect of tyrosol in combination with chlorhexidine gluconate against Candida albicans, Candida glabrata and Streptococcus mutans biofilms

• Grant number: 15/09135-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2015
• End date: October 31, 2016
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Principal Investigator: Douglas Roberto Monteiro
• Grantee: Luana Ribeiro Do Vale
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

The present study aims to evaluate the effect of tyrosol in combination with chlorhexidine gluconate on single and mixed biofilms of Candida albicans, Candida glabrata and Streptococcus mutans developed on acrylic resin and hydroxyapatite specimes within 24-well microtiter plates. First, according to the microdilution method, it will be determined the minimum inhibitory concentration (MIC) of tyrosol in combination with chlorhexidine gluconate capable of inhibiting the growth of each strain in the planktonic state. After, the combination of drugs at 20 times the MIC will be applied to single and mixed biofilms (24-h old) of the three species twice a day for 1 min, during 3 days (totaling 96 h-old biofilms). The effect of tyrosol in combination with chlorhexidine gluconate on biofilms will be quantified by counting the number of culturable cells, total biomass (crystal violet staining assay) and metabolic activity of the cells (XTT reduction assay). Biofilm structure after treatment with the combination of drugs will be visualized by scanning electron microscopy. Appropriate controls will be included in all analyzes, and all tests will be performed in triplicate on three different occasions. Data will be analyzed to employ the most appropriate statistical test. P < .05 will be considered statistically significant.