Quantitative detection of Streptococcus mutans in the dental plaque of Japanese preschool children by real-time PCR

Effects of short-term xylitol chewing gum on pro-inflammatory cytokines and Streptococcus mutans: A randomised, placebo-controlled trial

INTRODUCTION

Dental caries is an infectious disease with predominantly of cariogenic bacteria such as Streptococcus mutans (S mutans). Xylitol is considered as one of the effective agents that can limit this dental infection. In this randomised, placebo-controlled trial, we aimed to evaluate the potential reflection of short-term xylitol consumption on pro-inflammatory cytokines (TNF-α, IL-6 and IL-8) and S mutans counts by ELISA and qPCR (Quantitative real-time PCR), respectively.

METHODS

In this study, 154 participants were assigned to two groups, control and xylitol. Dental examination, saliva and swab samples were done at baseline and at 3-week for clinical and microbiological assessment.

RESULTS

In xylitol group at the end of 3-week, gingival and plaque index scores were significantly decreased with respect to baseline values (P < .001 and P < .05, respectively). The salivary concentration of TNF-α, IL-6 and IL-8 were statistically declined at 3-week, more so than those at baseline in xylitol group (P < .001). S mutans expression was reduced about fivefold at 3-week use of xylitol and it was a statistically significant difference compared to baseline (P < .001).

CONCLUSION

Intriguingly, even short-term consumption of xylitol might play a favourable role in maintaining the oral health status, possibly as a result of decreasing the release of pro-inflammatory cytokines and the counts of S mutans. Nonetheless, this investigation warrants further endorsement.

Impact of polyols on Oral microbiome of Estonian schoolchildren

BACKGROUND

Oral microbiome has significant impact on both oral and general health. Polyols have been promoted as sugar substitutes in prevention of oral diseases. We aimed to reveal the effect of candies containing erythritol, xylitol or control (sorbitol) on salivary microbiome.

METHODS

Ninety children (11.3 ± 0.6 years) consumed candies during 3 years. Microbial communities were profiled using Illumina HiSeq 2000 sequencing and real-time PCR.

RESULTS

The dominant phyla in saliva were Firmicutes (39.1%), Proteobacteria (26.1%), Bacteroidetes (14.7%), Actinobacteria (12%) and Fusobacteria (6%). The microbiome of erythritol group significantly differed from that of the other groups. Both erythritol and xylitol reduced the number of observed bacterial phylotypes in comparison to the control group. The relative abundance of the genera Veillonella, Streptococcus and Fusobacterium were higher while that of Bergeyella lower after erythritol intervention when comparing with control. The lowest prevalence of caries-related mutans streptococci corresponded with the lowest clinical caries markers in the erythritol group.

CONCLUSIONS

Daily consumption of erythritol, xylitol or control candies has a specific influence on the salivary microbiome composition in schoolchildren. Erythritol is associated with the lowest prevalence of caries-related mutans streptococci and the lowest levels of clinical caries experience.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT01062633.

Quantitative analysis of S. mutans, Lactobacillus and Bifidobacterium found in initial and mature plaques in Thai children with early childhood caries

AIMS

To quantify Streptococcus mutans, lactobacillus and bifidobacterium in initial and mature plaque collected from children with severe early childhood caries (S-ECC) and caries-free (CF) groups and to analyse the association between these bacteria and caries-related factors in each group.

STUDY DESIGN

A collection of 120 initial and overnight supra-gingival plaques were collected from Thai children aged 2-5 years-old (S-ECC = 60, CF = 60). Plaque, gingival indices and decayed, missing, filled tooth (dmft) scores were recorded. A questionnaire was used to assess the parents' attitudes and behaviour regarding the child's oral hygiene care and diet.

METHODS

After DNA extraction, quantitative real-time polymerase chain reaction (PCR) using fluorescent dye (SYBR green) was performed.

RESULTS

Levels of Streptococcus mutans, lactobacillus and bifidobacterium in both initial and mature plaques of S-ECC were significantly higher than those from the caries-free group (p < 0.05). The ratio of S. mutans, lactobacillus, and bifidobacterium to the total bacteria in S-ECC was significantly higher than in the caries-free group (p < 0.05). Levels of lactobacillus and bifidobacterium in both plaques significantly correlated with dmft scores and the plaque index, while S. mutans levels only correlated with dmft scores (p < 0.05). Factors that were significantly associated with caries were parents's education, duration of bottle feeding, especially during sleeping and the frequency of consuming cariogenic food between meals (p < 0.05).

CONCLUSION

Levels of S. mutans, lactobacillus, bifidobacterium and the ratio of these bacteria to total bacteria in both initial and mature plaques were significantly higher in children with S-ECC and related to dmft scores, oral hygiene and dietary habits.

Dental plaque microbial profiles of children from Khartoum, Sudan, with congenital heart defects

Few studies have focused on the bacterial species associated with the deterioration of the dental and gingival health of children with congenital heart defects (CHD). The aims of this study were (1) to examine the dental plaque of children with CHD in order to quantify bacterial load and altered bacterial composition compared with children without CHD; and (2) to investigate the correlation between the level of caries and gingivitis and dental biofilm bacteria among those children. In this cross-sectional study, participants were children (3-12 years) recruited in Khartoum State, Sudan. A total of 80 CHD cases from the Ahmed Gasim Cardiac Centre and 80 healthy controls from randomly selected schools and kindergartens were included. Participants underwent clinical oral examinations for caries (decayed, missing, and filled teeth indices [DMFT] for primary dentition, and DMFT for permanent dentition), and gingivitis (simplified gingival index [GI]). Pooled dental biofilm samples were obtained from four posterior teeth using paper points. Real-time quantitative polymerase chain reaction was used for the detection and quantification of Streptococcus mutans, Streptococcussanguinis, and Lactobacillus acidophilus. Checkerboard DNA-DNA hybridization was used for the detection of 40 additional bacterial species. CHD cases had a significantly higher caries experience (DMFT = 4.1 vs. 2.3, p < 0.05; DMFT = 1.4 vs. 0.7, p < 0.05) and a higher mean number of examined teeth with gingivitis (4.2 vs. 2.0; p < 0.05) compared with controls. S. mutans counts were significantly higher among the CHD cases (p < 0.05). Checkerboard results revealed that 18/40 bacterial species exhibited significantly higher mean counts among CHD cases (p < 0.01). Correlation analyses revealed that among CHD cases, the detection levels of Tannerella forsythia, Campylobacter rectus, Fusobacterium nucleatum subsp. vincentii, F. nucleatum subsp. nucleatum, and F. nucleatum subsp. polymorphum were highly positively correlated with GI. CHD cases harbor more cariogenic and periodontopathogenic bacterial species in their dental plaque, which correlated with higher levels of caries and gingivitis.

Rapid and sensitive PCR-dipstick DNA chromatography for multiplex analysis of the oral microbiota

A complex of species has been associated with dental caries under the ecological hypothesis. This study aimed to develop a rapid, sensitive PCR-dipstick DNA chromatography assay that could be read by eye for multiplex and semiquantitative analysis of plaque bacteria. Parallel oligonucleotides were immobilized on a dipstick strip for multiplex analysis of target DNA sequences of the caries-associated bacteria, Streptococcus mutans, Streptococcus sobrinus, Scardovia wiggsiae, Actinomyces species, and Veillonella parvula. Streptavidin-coated blue-colored latex microspheres were to generate signal. Target DNA amplicons with an oligonucleotide-tagged terminus and a biotinylated terminus were coupled with latex beads through a streptavidin-biotin interaction and then hybridized with complementary oligonucleotides on the strip. The accumulation of captured latex beads on the test and control lines produced blue bands, enabling visual detection with the naked eye. The PCR-dipstick DNA chromatography detected quantities as low as 100 pg of DNA amplicons and demonstrated 10- to 1000-fold higher sensitivity than PCR-agarose gel electrophoresis, depending on the target bacterial species. Semiquantification of bacteria was performed by obtaining a series of chromatograms using serial 10-fold dilution of PCR-amplified DNA extracted from dental plaque samples. The assay time was less than 3 h. The semiquantification procedure revealed the relative amounts of each test species in dental plaque samples, indicating that this disposable device has great potential in analysis of microbial composition in the oral cavity and intestinal tract, as well as in point-of-care diagnosis of microbiota-associated diseases.

Systemic consumption of probiotic curd and use of probiotic toothpaste to reduce Streptococcus mutans in plaque around orthodontic brackets

INTRODUCTION

The objectives of the study were to evaluate and compare the effects of the systemic consumption of probiotic curd and the topical application of probiotic toothpaste on the Streptococcus mutans levels in the plaque of orthodontic patients.

METHODS

The study consisted of 60 orthodontic patients divided into 3 groups of 20 each. Group 1 was the control group. The patients in group 2 were given probiotic curd, and those in group 3 were asked to brush twice daily with probiotic toothpaste (GD toothpaste; Dental Asia Manufacturing, Shah Alam, Selangor, Malaysia). Samples were collected at 2 times: before the study began and after 30 days. Plaque specimens were collected from the labial surfaces immediately surrounding the orthodontic brackets of the maxillary lateral incisors using a 4-pass technique. The presence of S mutans was evaluated using real-time polymerase chain reaction. Statistical analysis was performed, and comparisons were made using a 2-tailed chi-square test for categorical data (P <0.05).

RESULTS

At the end of the study, there were reductions in S mutans concentration in groups 2 and 3 that were statistically significant compared with group 1, but there was no statistically significant difference between groups 2 and 3.

CONCLUSIONS

The consumption of probiotic curd and the use of probiotic toothpaste cause a significant decrease in the S mutans levels in the plaque around brackets in orthodontic patients. Although the probiotic toothpaste was more effective than systemic consumption, this was not statistically significant.

Caries prevalence associated with Streptococcus mutans and Streptococcus sobrinus in Japanese schoolchildren

BACKGROUND

Streptococcus mutans and Streptococcus sobrinus are known to be associated with dental caries in humans.

AIM

We used a polymerase chain reaction method to detect S. mutans and S. sobrinus in 128 Japanese schoolchildren and then compared their presence with the dental caries experience.

DESIGN

Plaque samples were collected from all erupted tooth sites with a sterile toothbrush, and dental examinations were performed to determine the numbers of decayed and filled teeth in primary (dft) and permanent (DFT) dentition using the WHO caries diagnostic criteria. Fisher's PLSD test was employed to compare caries scores between combinations of the detected bacteria.

RESULTS

Streptococcus mutans and S. sobrinus were present in 38.3% and 68.0%, respectively, whereas 14.8% were positive for S. mutans alone, 44.5% for S. sobrinus alone, and 23.5% for both S. mutans and S. sobrinus, with 17.2% negative for both. The DFT, dft, and total (DFT + dft) scores for subjects positive for both S. mutans and S. sobrinus were significantly higher than those positive for S. mutans alone (P < 0.05, in triplicate).

CONCLUSION

These results suggest that schoolchildren harbouring both S. mutans and S. sobrinus have a significant higher dental caries experience in both permanent and primary teeth as compared to those with S. mutans alone.

Real-time quantitative polymerase chain reaction for enumeration of Streptococcus mutans from oral samples

This study compared SYBR Green real-time quantitative PCR (qPCR) with standard plate counting for the enumeration of Streptococcus mutans in oral samples. Oral samples (n = 710) were collected from high-caries-risk children for quantification of S. mutans by qPCR using primer pairs. The S. mutans copy number was calculated with reference to a qPCR quantification cycle (Cq) standard curve and compared with the absorbance value at 600 nm of a standard suspension of S. mutans UA159. The S. mutans copy number results were evaluated in relation to standard plate count (SPC) results obtained from each sample following culture on Petri plates containing S. mutans selective media and reported as colony-forming units (CFUs). The mean S. mutans copy number calculated from qPCR was higher than the SPC CFUs (1.3 × 10(6) and 1.5 × 10(5) CFUs, respectively). The qPCR values were usually higher in individual samples and qPCR detected the presence of S. mutans 84% (231/276) of the time that the SPC did not, compared with 33% (4/12) of the time when qPCR failed to detect S. mutans and the SPC did. The qPCR technique was found to be more sensitive for detection of S. mutans from oral samples, a method that is not dependent on the viability of the sample taken and therefore is proposed as a more reliable and efficient means of quantification of S. mutans.

Relationship of quantitative salivary levels of Streptococcus mutans and S. sobrinus in mothers to caries status and colonization of mutans streptococci in plaque in their 2.5-year-old children

OBJECTIVES

The aim of this study was to assess the relationships of quantitative salivary levels of Streptococcus mutans and S. sobrinus in mothers with the colonization of mutans streptococci (MS) in plaque and caries status in their 2.5-year-old children. Furthermore, the dynamics of caries status in the children was evaluated in a 2-year follow-up survey.

METHODS

After oral examination of 54 mother-and-child pairs, the saliva samples from the mothers and the plaque samples from the children were collected. The levels (log DNA copies/ml saliva) of S. mutans and S. sobrinus were quantified using real-time polymerase chain reaction (PCR) assays, while MS in the plaque samples were detected using a cultivation method. In addition, 50 of the 54 children participated in a 2-year follow-up survey of caries prevalence.

RESULTS

In the 2.5-year-old children, the percentage of dft-positive subjects and mean number of dft were significantly higher in the MS(+) group when compared with the MS(-) group. Findings from the 2-year follow-up survey indicated that MS(+) subjects had a persistently higher mean number of dft at 4.5 years. The 2.5-year-old children were divided into three groups based on the quantitative levels of salivary S. mutans and S. sobrinus in their mothers: those whose mothers had low levels of S. mutans (<4 log DNA copies/ml) and S. sobrinus (<2) (group 1); those whose mothers had a high level of S. mutans (> or = 4) and low level of S. sobrinus (<2) (group 2); and those whose mothers had high levels of both (> or = 4 and > or = 2, respectively) (group 3). Among the three groups, the percentages of MS(+) and dft-positive children were highest in group 3 and lowest in group 1. Furthermore, multiple logistic regression analyses revealed that grouping the mothers based on salivary level of S. mutans and S. sobrinus was an efficient means to predict both MS colonization (OR = 2.96) and prevalence of dental caries (OR = 9.39) in children at 2.5 years of age.

CONCLUSIONS

In the 54 mother-and-child pairs tested, the maternal salivary levels of S. mutans and S. sobrinus determined by real-time PCR were significantly related to MS colonization in plaque as well as dental caries in their children at 2.5 years of age. Thus, determination of maternal levels of both organisms using the present cut-off values is proposed as an efficient method to indicate the risks of maternal transmission of MS and childhood dental caries.

Quantitative real-time polymerase chain reaction for Streptococcus mutans and Streptococcus sobrinus in dental plaque samples and its association with early childhood caries

BACKGROUND

Streptococcus mutans and Streptococcus sobrinus are closely associated with the development of early childhood caries (ECC). Recently, quantitative real-time polymerase chain reaction (qRT-PCR) has been used for rapid and accurate quantification of these bacterial species.

AIM

This study aims to detect quantitatively the levels of S. mutans and S. sobrinus in plaque samples by qRT-PCR, and to assess their association with the prevalence of ECC in Korean preschool children.

DESIGN

One hundred and five children (71 months old or younger) were examined and classified into three groups (caries-free, ECC, severe ECC). Dental plaque samples were collected and qRT-PCR was conducted using oligonucleotide primers specific for glucosyltransferase gene (S. mutans-gtfB, S. sobrinus-gtfU) and universal primer. Pearson's correlation test was conducted to evaluate the relationship between the dmfs (decayed, missing, or filled surfaces primary teeth) scores and the microbiological findings.

RESULTS

There was a significant difference between the levels of S. mutans and S. sobrinus in the plaque samples of the three groups (P < 0.05). The proportion of S. sobrinus to S. mutans showed strong correlation to the dmfs scores (r = 0.748, P < 0.05).

CONCLUSIONS

The qRT-PCR results of this study showed that children with ECC had higher level of S. mutans and S. sobrinus in their dental plaque samples. The children with higher ratio of S. sobrinus to S. mutans in their dental plaque showed higher incidence of ECC.