Effect of different salivary glucose concentrations on dual-species biofilms of Candida albicans and Streptococcus mutans

Abstract

Diabetes mellitus is one of the most prevalent diseases worldwide. The glucose levels found in the blood of diabetic patients can be reflected in the saliva, which can favor biofilm growth and predispose denture wearers to oral candidiasis. This study aimed to evaluate the effect of different salivary glucose concentrations on dual-species biofilms of Candida albicans and Streptococcus mutans. A 96-h biofilm was developed on acrylic resin specimens exposed to ‘feast’ (10% sucrose) and ‘famine’ periods. Biofilms were constantly exposed to salivary glucose concentrations equivalent to 0, 20, 60 and 100 mM. Higher salivary glucose concentrations resulted in increased counts of C. albicans and a higher quantity of insoluble extracellular polysaccharides. All biofilms presented high phospholipase activity. The biofilms were characterized by the predominance of yeast cells and microcolonies in all the groups analyzed with co-localization of both species. Higher salivary glucose concentrations formed more robust and potentially virulent biofilms.

Keywords:

• Glucose
• oral candidiasis
• biofilms

Acknowledgements

The authors would like to thank the Coordination for the Improvement of Higher Education Personnel (CAPES) and the National Council for Scientific and Technological Development (CNPq) for granting scholarships to IMB (CAPES-1757970) and ACMB (CNPq-130005), respectively. This research was supported by the National Council for Scientific and Technological Development (CNPq), under reseach grant: 422866/2018-0.

Disclosure statement

The authors declare that they have no associative interest that represents a conflict of interest related to the manuscript.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.