Glucose supplementation effect on the acidogenicity, viability, and extracellular matrix of Candida single- and dual-species biofilms

Abstract

Aim: Evidence of glucose supplementation effect on Candida biofilm metabolism has not been demonstrated. Therefore, the aim of the present study was to evaluate the effect of glucose concentration on Candida biofilms.

Methods: Single- and dual-species biofilms of Candida were grown on saliva-coated poly(methyl-methacrylate) disks for 72 hours. Biofilms (N = 8/group) were exposed to the following concentrations of glucose: 100 mmol/L (G100), 300 mmol/L (G300), and no glucose (G0: control). Biofilms were collected to determine the acidogenicity, viability, amount of soluble and insoluble extracellular polysaccharides (IEPS), and surface roughness. Data were analyzed using analysis of variance and Tukey's tests (α < 0.05).

Results: Single- and dual-species biofilms from G300 were more acidogenic at 48 and 72 hours compared to G100 and G0 (P < 0.05). The viability of the G100 and G300 groups did not differ (P > 0.05), but differed statistically from G0. The amount of IEPS in the G300 group was statistically higher than the G0 and G100 groups (P < 0.05). The G300 group also presented a higher IEPS proportion per number of viable cells compared to others. G300 presented greater surface roughness for both single- (mean roughness = 1460 μm) and dual-species (mean roughness = 1990 μm) biofilms.

Conclusions: Higher glucose concentration (300 mmol/L) during biofilm development favors the growth of single- and dual-species biofilms of Candida.

Keywords: Candida; biofilm; extracellular polysaccharides; glucose; oral candidiasis.