Streptococcus mutans Membrane Vesicles Harboring Glucosyltransferases Augment Candida albicans Biofilm Development

Abstract

Candida albicans, as the most common fungus in the oral cavity, is often detected in early childhood caries. Streptococcus mutans is the major etiological agent of dental caries, but the role of S. mutans on C. albicans growth and biofilm development remains to be elucidated. Membrane vesicles (MVs) are a cell-secreted subcellular fraction that play an important role in intercellular communication and disease progression. In the present study, we investigated whether MVs from S. mutans augment C. albicans growth and biofilm development. The results indicated that S. mutans MVs augmented C. albicans biofilm development but had no significant effect on C. albicans growth under planktonic conditions. Subsequently, we labeled S. mutans MVs with PKH26 and used confocal laser scanning microscopy (CLSM) to track S. mutans MVs, which were observed to be located in the C. albicans biofilm extracellular matrix. Monosaccharide tests showed that S. mutans MVs contribute to sucrose metabolism in C. albicans. Polysaccharides were significantly enriched in the S. mutans MV-treated group. MVs from gtfBC mutant strains were compared with those from the wild-type S. mutans. The results revealed that MVs from the gtfBC mutant had no effect on C. albicans biofilm formation and exopolysaccharide production. In addition, C. albicans biofilm transcriptional regulators (Ndt80, Als1, Mnn9, Van1, Pmr1, Gca1, and Big1) expression were upregulated in S. mutans MV-treated group. In summary, the results of the present study showed that S. mutans MVs harboring glucosyltransferases involved in exopolysaccharide production augment C. albicans biofilm development, revealing a key role for S. mutans MVs in cross-kingdom interactions between S. mutans and C. albicans.

Formation, Development, and Cross-Species Interactions in Biofilms

“…Recent research found that MVs promoted the formation of single-strain bacterial biofilms ( Seike et al, 2020 ). The MVs from S. mutans augmented C. albicans biofilm development but had no significant effect on C. albicans growth under planktonic conditions ( Wu et al, 2020 ). However, the role of MVs and GTAs in multistrain bacterial biofilms remain unclear.…”

Streptococcus Mutans Membrane Vesicles Enhance Candida albicans Pathogenicity and Carbohydrate Metabolism

“…To further investigate the effect of S. mutans MVs on C. albicans biofilm cariogenic potential, a C. albicans biofilmbovine dentin model was employed according to Sampaio et al' experimental method (Sampaio et al, 2019). S. mutans MVs have no significant effect on the pH of the C. albicans biofilm culture medium supernatants, which was reported by our previous study (Wu et al, 2020). Enamel demineralization is mainly due to the acid production of plaque biofilms (Wu et al, 2018), and C. albicans is usually detected in dentin tubules (Klinke et al, 2011).…”

“…S. mutans MVs were harvested by centrifugation at 100,000 × g for 70 min at 4°C. The S. mutans MVs yield was quantified using a BCA assay (CWBIO, Beijing, China) as we previously described (Wu et al, 2020).…”

“…It has been demonstrated that S. mutans MVs are involved in cell wall synthesis, bacterial adhesion and biofilm formation ( Cao et al., 2020 ; Morales-Aparicio et al., 2020 ). Moreover, they can promote the biofilm formation of Streptococcus mitis , Streptococcus oralis , C. albicans and other microorganisms in the oral cavity ( Senpuku et al., 2019 ; Wu et al., 2020 ). Our previous research found that S. mutans MVs harboring glucosyltransferases augment C. albicans biofilm formation by increasing exopolysaccharide production ( Cao et al., 2020 ; Wu et al., 2020 ).…”

The Influence of Propolis on Dental Plaque Reduction and the Correlation between Dental Plaque and Severity of COVID-19 Complications—A Literature Review

“…2.4.1.5; sucrose: 1,6-a- d -glucan 6-a- d -glucosyltransferase; dextransucrase, because they synthesize water-soluble and insoluble glucans from sucrose. They act like an invertase when hydrolyzing sucrose into glucose and fructose and as a transferase when transferring the released glucose into the growing glucan chains [ 6 ].…”