Growth and viability of Streptococcus mutans in sucrose with different concentrations of Stevia rebaudiana Bertoni

Abstract

Objective: To evaluate total absorbance, planktonic growth, biofilm formation, viability, metabolic activity and pH of Streptococcus mutans UA159 cultures when different dilutions of Stevia Rebaudiana Bertoni were applied and to determine the minimum inhibitory concentration (MIC) and the minimum biofilm inhibitory concentration (MBIC) of Stevia on S. mutans. Materials and methods: The effects of different dilutions of Stevia (0-400 mg/ml) on S. mutans total growth, planktonic growth, biofilm formation, viability, metabolic activity and pH during a 72-hour growth period were evaluated in this in vitro study. A stock solution was prepared by mixing 10 ml of tryptic soy broth (TSB) supplemented with 1% sucrose (TSBS) and 4 g of Stevia. Results: S. mutans total growth and biofilm formation decreased with reduced concentrations of Stevia. Furthermore, the MIC was 25 mg/ml and the MBIC was 6.25 mg/ml. Complete eradication of S. mutans was not observed with any of the Stevia concentrations. Planktonic growth of S. mutans was not repressed by high concentrations of Stevia and most of the Stevia concentrations generated an increased pH. Conclusion: Because Stevia reduces biofilm and acid production, Stevia can be considered a non-cariogenic sweetener. Clinical relevance: This study confirms the anticariogenic effect of Stevia, like it has been previously reported; but more studies on the most effective concentration are needed and in the present study, the minimum inhibitory concentration (MIC) and the minimum biofilm inhibitory concentration (MBIC) was determined in the presence of sucrose.Additionally, this is the first study to evaluate the effect of Stevia on S. mutans metabolic activity.

Efecto de la Stevia rebaudiana en el crecimiento del Streptococcus mutans

“…Además, reportan que la Stevia en diversas concentraciones aumenta el pH y disminuye la producción del ácido en el Streptococcus mutans (14) . Como también la reducción del recuento salival del Streptococcus mutans, y además aumenta el flujo lo cual evitara que se adhiera la bacteria y el aumento del pH salival para así lograr un efecto anticariogénico (5)(6)(7)15) . Por consiguiente, coincide con nuestra investigación que disminuye el factor de riesgo cariogénico del Streptococcus mutans (16) .…”

In vitro assessment of natural extract as irrigant on root dentin microhardness

“…Escobar et al testi ied that S. mutans total growth and bio ilm formation showed a marked decrease with reduced concentrations of Stevia along with reduced bio ilm and acid production (Escobar et al, 2020). When it comes to microhardness, Maryam Kishta et al reported a loss of microhardness of bovine dentin with the use of 0.5% and 5% stevia extract (Kishta-Derani et al, 2012).…”

Single‐cell Raman microspectroscopy‐based assessment of three intracanal disinfectants' effect on Enterococcus faecalis

“…In previous studies, assessments of disinfectants' efficacy have been largely based on growth inhibition of microbial cells. Growth‐dependent methods typically evaluate the sensitivity of cell growth to disinfectants through dilution and diffusion experiments and then derive quantitative parameters such as “minimum inhibitory concentration” (MIC) [ 14 ] to guide clinical drug usage. However, these methods are usually time and labor consuming (frequently over 24 h [ 15 ] ) and generally unable to tackle yet‐to‐be‐cultured microorganisms.…”