IADR Abstract Archives
The Anticariogenic Effect of Xylitol on Seven Streptococus mutans Strains
Objectives: The objective of this study was to investigate the affect of xylitol on the viability and biofilm formation of seven S. muatns strains.
Methods: Seven Streptococcus mutans strains (UA159, UA130, NG8, LM7, A32-2, OMZ175, and 10449) were cultured in a tryptic soy broth (TSB) solution for 24 hours in 5% CO2 incubator at 37°C. Eight concentrations (0.2, 0.1, 0.05, 0.025, 0.0125, 0.0063, 0.0031, 0.016g/mL) of xylitol with tryptic soy broth with sucrose (TSBS) were prepared through serial dilution. Sterile 96-well flat-bottom polystyrene microtiter plates were utilized and 10μL of each strain inoculum was added in each well. Microtitre plates were incubated for 24 hours and absorbance readings were recorded using a spectrophotometer. Resultant biofilms were fixed by adding 200 μL of 10% formaldehyde. Crystal violet solution was added after washing followed by 200μL Isopropanol. Biofilm absorbance readings were measured at 595nm wavelength. Two strains (10449 and A32-2) were further investigated using agar diffusion assay to observe the inhibition zones. All absorbance values were analyzed using one-way analysis of variance (ANOVA) at 0.05 significance level followed by Tukey’s post hoc pairwise comparisons.
Results: 10449 was the most sensitive strain in the total absorbance assay. In the biofilm assay, OMZ175 and UA130 were the least resistant strains. For agar diffusion clear inhibition zones were observed with 10449 and A32-2 at concentrations of .0031g/mL and above.
Conclusions: There was a clear difference between the seven tested strains against xylitol concentrations indicating a variation of the inhibitory effect of xylitol according to the type of S. mutans.
Methods: Seven Streptococcus mutans strains (UA159, UA130, NG8, LM7, A32-2, OMZ175, and 10449) were cultured in a tryptic soy broth (TSB) solution for 24 hours in 5% CO2 incubator at 37°C. Eight concentrations (0.2, 0.1, 0.05, 0.025, 0.0125, 0.0063, 0.0031, 0.016g/mL) of xylitol with tryptic soy broth with sucrose (TSBS) were prepared through serial dilution. Sterile 96-well flat-bottom polystyrene microtiter plates were utilized and 10μL of each strain inoculum was added in each well. Microtitre plates were incubated for 24 hours and absorbance readings were recorded using a spectrophotometer. Resultant biofilms were fixed by adding 200 μL of 10% formaldehyde. Crystal violet solution was added after washing followed by 200μL Isopropanol. Biofilm absorbance readings were measured at 595nm wavelength. Two strains (10449 and A32-2) were further investigated using agar diffusion assay to observe the inhibition zones. All absorbance values were analyzed using one-way analysis of variance (ANOVA) at 0.05 significance level followed by Tukey’s post hoc pairwise comparisons.
Results: 10449 was the most sensitive strain in the total absorbance assay. In the biofilm assay, OMZ175 and UA130 were the least resistant strains. For agar diffusion clear inhibition zones were observed with 10449 and A32-2 at concentrations of .0031g/mL and above.
Conclusions: There was a clear difference between the seven tested strains against xylitol concentrations indicating a variation of the inhibitory effect of xylitol according to the type of S. mutans.
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