Disruption of Streptococcus mutans and Candida albicans synergy by a commensal streptococcus

Abstract

Polymicrobial interactions in dental plaque play a significant role in dysbiosis and homeostasis in the oral cavity. In early childhood caries, Streptococcus mutans and Candida albicans are often co-isolated from carious lesions and associated with increased disease severity. Studies have demonstrated that metabolic and glucan-dependent synergism between C. albicans and S. mutans contribute to enhanced pathogenesis. However, it is unclear how oral commensals influence pathogen synergy. Streptococcus parasanguinis, a hydrogen peroxide (H2O2) producing oral commensal, has antimicrobial activity against S. mutans. In this study, we utilized a three species biofilm model to understand the impact of S. parasanguinis on S. mutans and C. albicans synergy. We report that S. parasanguinis disrupts S. mutans and C. albicans biofilm synergy in a contact and H2O2-independent manner. Further, metabolomics analysis revealed a S. parasanguinis-driven alteration in sugar metabolism that restricts biofilm development by S. mutans. Moreover, S. parasanguinis inhibits S. mutans glucosyltransferase (GtfB) activity, which is important for glucan matrix development and GtfB-mediated binding to C. albicans mannan. Taken together, our study describes a new antimicrobial role for S. parasanguinis and highlights how this abundant oral commensal may be utilized to attenuate pathogen synergism.

Recent Advances and Opportunities in the Study of Candida albicans Polymicrobial Biofilms

“…Although several researchers have studied the impact of individual (or a few) members of the microbiome on C. albicans (as discussed in this review), the complexity of the microbiome poses challenges in gaining a more complete picture of how all the interactions within the microbiome. A recent example of the influence of a commensal bacterium on a PMB is found in the work of Huffines and Scoffield (2020) who found that the commensal bacterium, Streptococcus parasanguinis, influenced C. albicans-S. mutans PMB formation. In this context, S. parasanguinis decreased biofilm formation and restricted the incorporation of C. albicans into the PMB.…”

In it together: Candida–bacterial oral biofilms and therapeutic strategies

“…Furthermore, the use of Lactobacillus plantarum CCFM8724 outperformed chlorhexidine in treating and preventing dental caries induced by C. albicans-S. mutans biofilm in vivo (Zhang et al, 2020). Similarly, antagonizing Streptococcus parasanguinis disrupted C. albicans-S. mutans biofilm by altering sugar metabolism and glucosyltransferase activity of S. mutans (Huffines and Scoffield, 2020), which is critical for EPS-matrix development and GtfB-mediated cross-kingdom interaction (Hwang et al, 2017;Kim et al, 2021). Another alternative approach for biofilm eradication is antimicrobial photodynamic therapy (aPDT).…”

“…mutans biofilm by altering sugar metabolism and glucosyltransferase activity of S . mutans (Huffines and Scoffield, 2020), which is critical for EPS‐matrix development and GtfB‐mediated cross‐kingdom interaction (Hwang et al ., 2017; Kim et al ., 2021). Another alternative approach for biofilm eradication is antimicrobial photodynamic therapy (aPDT).…”

Nitrite Triggers Reprogramming of the Oral Polymicrobial Metabolome by a Commensal Streptococcus

“…We previously demonstrated the ability of S. parasanguinis to inhibit the growth of S. mutans and caries development in a H 2 O 2 - and nitrite-dependent manner using a rat caries model ( Scoffield et al., 2019 ). Further, we have demonstrated that S. parasanguinis disrupts synergy between S. mutans and C. albicans in a contact and H 2 O 2 -independent manner ( Huffines and Scoffield, 2020 ). While bacterial and host-derived metabolites are known to shape oral polymicrobial communities and nitrite has been shown to aid oral commensal streptococci in the inhibition of diverse pathogens, no studies have observed how oral commensals such as S. parasanguinis influence the metabolomes of polymicrobial communities in the presence of nitrite.…”