Xylitol is a five-carbon sugar alcohol that inhibits the growth of oral streptococci, including Streptococcus mutans. In this study, we tested xylitol sensitivity among the oral streptococci. We also compared nucleotide homology of putative fructose phosphotransferase system (PTS) and xylitol sensitivity, since xylitol is transported via the fructose PTS. Among the tested Streptococci, S. pneumonia showed the highest resistance to xylitol while S. gordonii and S. sanguinis showed the most sensitive growth inhibition. These streptococci could be grouped according to their xylitol sensitivity. S. mutans and S. salivarius showed similar bacterial growth inhibition by xylitol. S. mitis, S. oralis, S. pneumonia, S. intermedius and S. anginosus showed relatively low sensitivity to xylitol. When the genetic homologies of five fructose PTSs were compared among the tested streptococci, closely related streptococci showed similar sensitivity to xylitol. Taken together, fructose PTSs may mediate the sensitivity to xylitol in oral streptococci.
Fructose ; Pneumonia ; Streptococcus ; Streptococcus mutans ; Xylitol*

OBJECTIVETo study the inhibitory effect of erythritol by contrast to xylitol on growth and acid production of Streptococcus mutans (S. mutans).

METHODSS. mutans were incubated respectively in 0.5%, 1%, 2%, 4%, 8%, 12%, 16% erythritol or xylitol culture medium under anaerobic conditions. The A and pH value of the mediums were measured at 0, 2, 4, 6, 8, 10, 12, 18, 24 hours, following the profile plots by SPSS.

RESULTSThe data of A were higher in 0.5%, 1%, 2% erythritol culture medium than in xylitol culture medium at the same concentration, while lower in 8%, 12%, 16% erythritol culture medium than in xylitol culture medium at the same concentration. The data of pH were lower in 0.5%, 1%, 2% erythritol culture medium than in xylitol culture medium at the same concentration, while higer in 8%, 12%, 16% erythritol culture medium than in xylitol culture medium at the same concentration. It indicated that the growth and acid production of S. mutans were higer in 0.5%, 1%, 2% erythritol culture medium than in xylitol culture medium at the same concentration, while lower in 8%, 12%, 16% erythritol culture medium than in xylitol culture medium at the same concentration.

CONCLUSIONCompared with xylitol, erythritol in low concentration has weaker effort on the growth and acid production of S. mutans, while having stronger effort in high concentration.

The purpose of this study was to evaluate the effectiveness of gargling solution with 0.05% NaF and 10% Xylitol in orthodontic patients with fixed appliance. The sample consisted of 20 patients who were classified into an experimental group and a control group, 10 patients each. Experimental group was used experimental gargling solution and the control group was used with placebo solution. The results were as follows. 1. There were significant reduction in the number of S. mutans C.F.U. between pre and post 3 weeks(p<0.01), 9 weeks(p<0.05) in experimental group. 2. There were significant reduction in the ration of S. mutans C.F.U. to total C.F.U between pre and post 3, 6, 9 weeks(p<0.01) in experimental group. 3. S. mutans, which were reduced until 3 weeks, did not show significant change after 3, 6, 9 weeks. 4. S. mutans were strongly suppressed until 3 weeks after gargling solution with 0.05% NaF and 10% Xylitol.
Dental Plaque* ; Humans ; Streptococcus mutans* ; Streptococcus* ; Xylitol

The purpose of this study was to evaluate the effectiveness of gargling solution with 0.05% NaF and 10% Xylitol in orthodontic patients with fixed appliance. The sample consisted of 30 adolescent patients who were classified into an experimental group and a control group, 15 patients each. Experimental group was used experimental gargling solution and the control group was used with placebo solution. The change of S. mutans in saliva was observed by Cariescreen(R) SM kit at pre and post 2, 4, 6, 8 weeks. The results were as follows. 1. There were significant reduction in the number of S. mutans in saliva between pre and post 2 weeks(p<0.01), 4 weeks(p<0.05), 6 weeks(p<0001), and 8 weeks(p<0001) in experimental group. And significant reduction also were observed in the number of Ss mutans in saliva between post 2 weeks, 6 weeks(p<0.05), and 8 weeks(p<0.05), but no significant reduction were showed in control group. 2. There were significant correlation in the number of S. mutans between each measurement time(pre and post 2, 4, 6, 8 weeks) in control group. 3. There weee no correlation between pre and post 2 weeks, but significant correlation were observed between 2, 4, 6, 8 weeks in experimental group.
Adolescent ; Humans ; Saliva* ; Streptococcus mutans* ; Streptococcus* ; Xylitol

OBJECTIVEThis research aimed to study the inhibitory effect of xylitol on the growth and acid production of Actinomyces viscosus (A. viscosus).

METHODSWe cultivated A. viscosus in anaerobic conditions with different concentrations (128, 64, 32, 16, 8, and 4 g x L(-1)) of xylitol brain heart infusion liquid medium and determined the minimum inhibitory concentration (MIC). Subsequently, we measured the pH value of the control group, as well as those of 1/2, 1/4, 1/8 MIC, and MIC concentration groups at 1.5, 3, 6, 12, 24, and 48 h. The Delta pH and OD550 at 2, 4, 6, 8, 10, and 12 h were calculated. We discovered that the minimum xylitol concentrations suppressed 50% and 90% A. viscosus biofilm formation (i.e., MBIC50 and MBIC90). SPSS 19.0 was used to analyze the collected data, and conclusions were drawn afterward.

RESULTSXylitol inhibited the growth ofA. viscosus at MIC of 64 g x L(-1). After 12 h, the differences of pH value among groups were all statistically significant (P < 0.05), and Delta pH increased when the MIC concentration decreased. Except for the 1/2 MIC and MIC groups, the differences of OD550 among groups had no statistical significance (P>0.05), and OD550 also increased when the MIC concentration decreased. These results imply that the ability ofA. viscosus to grow and produce acid in 1/2 MIC and MIC conditions will be reduced with the increase in xylitol concentration. The value of MIBC50 was 64 g x L(-1), whereas the value of MIBC90 was 128 g x L(-1). This finding indicates that the xylitol medium can restrict A. viscosus biofilm formation.

CONCLUSIONXylitolcan effectively inhibit the growth, adhesion, and acid production ofA. viscosus, protecting teeth from cariogenic bacteria and preventing caries to a certain extent.

OBJECTIVES: Xylitol is an effective anticarious natural sugar substitute, by inhibiting the virulence of Streptococcus mutans (S. mutans). However, long-term xylitol consumption leads to an emergence of the xylitol-resistant (XR) strains. This study aimed to confirm the general characteristics, mRNA expression of gtf genes, and adhesive ability of the xylitol-sensitive (XS) and XR S. mutans , by xylitol-treated concentrations. METHODS: S. mutans KCTC3065 was maintained in TYE medium, containing 0.4% glucose with 1% xylitol for 30 days at 37degrees C, 10% CO2 to form XR strain and the same procedures, without xylitol, were repeated for the formation of XS S. mutans. Both XS and XR were cultured by xylitol-treated concentrations (0%, 0.1% and 1%), then, general characteristics, such as growth and acid production, mRNA expression of gtf genes and adhesive ability were analyzed. RESULTS: Xylitol reduced the cell growth of XS S. mutans in a dose-dependent manner, but did not reduce the XR. Xylitol inhibited acid production of XS in a dose-dependent manner. However, it did not inhibit that of XR. Xylitol reduced the gtfB and gtfD mRNA expression of the XS S. mutans, which the genes synthesized soluble and insoluble extracellular polysaccharides, but not reduced that of the XR. By a microtiter plate assay, biofilm formation was more reduced in the XR strains, which means biofilm's adhesive ability of XR S. mutans was lower than that of the XS. CONCLUSIONS: These results indicate that a lower level of adhesive ability for XR S. mutans is related with mRNA expression level of gtf genes, which suggested that the XR strains may be less cariogenic than that of the XS.
Adhesives ; Biofilms ; Glucose ; Glucosyltransferases ; Polysaccharides ; RNA, Messenger ; Sprains and Strains ; Streptococcus ; Streptococcus mutans ; Sweetening Agents ; Xylitol

OBJECTIVES: This study was designed to evaluate the synergistic antibacterial effect of xylitol and ursolic acid (UA) against oral biofilms in vitro. MATERIALS AND METHODS: S. mutans UA 159 (wild type), S. mutans KCOM 1207, KCOM 1128 and S. sobrinus ATCC 33478 were used. The susceptibility of S. mutans to UA and xylitol was evaluated using a broth microdilution method. Based on the results, combined susceptibility was evaluated using optimal inhibitory combinations (OIC), optimal bactericidal combinations (OBC), and fractional inhibitory concentrations (FIC). The anti-biofilm activity of xylitol and UA on Streptococcus spp. was evaluated by growing cells in 24-well polystyrene microtiter plates for the biofilm assay. Significant mean differences among experimental groups were determined by Fisher's Least Significant Difference (p < 0.05). RESULTS: The synergistic interactions between xylitol and UA were observed against all tested strains, showing the FICs < 1. The combined treatment of xylitol and UA inhibited the biofilm formation significantly and also prevented pH decline to critical value of 5.5 effectively. The biofilm disassembly was substantially influenced by different age of biofilm when exposed to the combined treatment of xylitol and UA. Comparing to the single strain, relatively higher concentration of xylitol and UA was needed for inhibiting and disassembling biofilm formed by a mixed culture of S. mutans 159 and S. sobrinus 33478. CONCLUSIONS: This study demonstrated that xylitol and UA, synergistic inhibitors, can be a potential agent for enhancing the antimicrobial and anti-biofilm efficacy against S. mutans and S. sobrinus in the oral environment.
Biofilms* ; Hydrogen-Ion Concentration ; Polystyrenes ; Streptococcus ; Streptococcus mutans ; Streptococcus sobrinus ; Xylitol*

This study aimed to examine the inhibitory effect of rare sugars on Streptococcus mutans (S. mutans) in the presence of sucrose. Xylitol and three rare sugars (D-xylose, D-lyxose and D-mannose) were used in this study. S. mutans KCTC 3065 was cultured in Brain Heart Infusion (BHI) medium containing xylitol, D-xylose, D-lyxose, or D-mannose in the presence of sucrose, and the effect on S. mutans growth was assessed by measuring solution turbidity at different time points after inoculation. To assess effects on pH, sucrose was added at different concentrations, and solution pH was measured at different time points after inoculation. All sugars significantly inhibited the growth of S. mutans in the presence of sucrose. Especially, D-lyxose and D-mannose exhibited significantly greater inhibition than that of xylitol. Furthermore, unlike D-lyxose, D-mannose significantly inhibited the decrement of pH, and its effect was greater than that of xylitol. Taken together, D-mannose has strong inhibitory effect on S. mutans in the presence of sucrose.
Brain ; Carbohydrates ; Dental Caries ; Heart ; Hydrogen-Ion Concentration ; Mannose* ; Streptococcus mutans* ; Streptococcus* ; Sucrose* ; Xylitol ; Xylose

Xylitol, a five-carbon sugar alcohol, has many interesting applications in the food, pharmaceutical, and odontological industries, owing to its high sweetening power, its anticariogenic properties, and its insulin-independent metabolism. The bioconversion of detoxified hemicellulosic hydrolysate to xylitol by microorganisms could be a cheaper alternative to the current chemical process, since it is a simple process, with great specificity and low energy requirements. However, the success of fermentations for xylitol production depends on the productivity of the strain and its tolerance to different toxic or inhibitory compounds existing in the hydrolysates. In addition, a number of culture process parameters proved to have significant effects on xylitol production in hemicellulosic hydrolysate media. One of the most important control variables in this bioconversion is the aeration level, which affects the biochemical pathways in the xylose metabolism. The production of biomass is favored by aerobic conditions, while under anaerobic conditions xylose cannot be assimilated by yeast, whereas xylitol is formed in oxygen-limited incubation conditions. An adapted Candida sp. with enhanced resistance to the inhibitors in the hydrolysate can directly ferment the simply detoxified corn cob hemicellulosic hydrolysate to xylitol. In the present study, the combined effects of shaking speed, C/ N ratio, initial pH, and inoculum level on the fermentation of corn cob hemicellulosic hydrolysate to xylitol by an adapted Candida sp. were investigated using an orthogonal experimental design in flask. As a result, the optimum fermentation conditions were as follows: 180 r/min, a C/N ratio of 50, initial pH 5.5, and an inoculum level of 5% (volume ratio). Moreover, the optimum concentration factor of hydrolysate varied between 3.0 and 3.72 was obtained. Based on these results, in order to evaluate the effect of aeration rate on the fermentation of corn cob hemicellulosic hydrolysate to xylitol in fermentor, batch fermentations were carried out in a 3.7 L stirred fermentor using four different aeration strategies, including three kind of two-stage aeration strategies, which provided relatively high aeration rate in the early stage but reduced it in the later stage, and including a one-stage aeration strategy provided a constant aeration rate. With respect to xylitol yield, the results indicated that two-stage aeration strategy was significantly superior to one-stage aeration strategy. The highest xylitol yield (0.75 g/g) was obtained with oxygen supply strategy C (3.75 L/min for first 24 h, then lowered it to 1.25 L/min, 2.5 L fermentation medium was employed). In this process, without extensive detoxification of hydrolysate, an adapted Candida sp. can efficiently ferment the simply treated corn cob hemicellulosic hydrolysate to xylitol under the optimized fermentation conditions. This work should help the development of an efficient process for producing xylitol from corn cob hemicellulosic hydrolysate on a larger scale by bioconversion.
Aerobiosis ; Candida tropicalis ; metabolism ; Fermentation ; Hydrolysis ; Polysaccharides ; metabolism ; Xylitol ; biosynthesis ; Zea mays ; metabolism

The aim of this study was to evaluate the effect a chewable tablet containing sodium fluoride and xylitol (DenPo, Hamizzle, Bucheon, Kyungki) on the oral hygiene state in the orthodontic patients. The subjects consisted of 30 adult orthodontic patients, who have worn the fixed orthodontic appliance at least 6 months. They were instructed to use the tablet forth a day. Gingival index (GI), plaque index (PI), and sulcus bleeding index (SBI) of upper and lower anterior and posterior regions were measured before using the tablet (T0), 2 weeks after using the tablet (T1), and 4 weeks after using the tablet (T2). The data were analyzed with Wilcoxon signed ranks tests. The results were as follows ; 1. PI was decreased significantly in the T1 and T2 stage compared with T0 stage in the both anterior and posterior regions (p < 0.05). Although PI was decreased in the T2 stage compared with T1, there was not statistical significance (p > 0.05). 2. GI and SBI showed similar results compared with PI. In the T1 and T2 stage, there was statistically significant decrease in the GI and SBI (p < 0.05). This study showed that the DenPo tablet could be used as an adjunct to improve oral hygiene in the orthodontic patients. The decrease of the indices may suggest that DenPo tablet could be effective in the plaque removal and prevention of gingival inflammation in the orthodontic patients.
Adult ; Gyeonggi-do ; Hemorrhage ; Humans ; Inflammation ; Oral Hygiene* ; Orthodontic Appliances ; Periodontal Index ; Sodium Fluoride* ; Sodium* ; Xylitol*