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1.
Bioengineered ; 11(1): 449-462, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32208897

RESUMO

Human dental pulp cells (hDPCs) possess the capacity to differentiate into odontoblast-like cells in response to exogenous stimuli. Histone methylation is one of the most robust epigenetic marks and is essential for the regulation of multiple cellular processes. Previous studies have shown that histone methyltransferases (HMTs) and histone demethylases (HDMs) are crucial for the osteogenic differentiation of human bone marrow, adipose tissue, and tooth tissue. However, little is known about the role of histone methylation in hDPC differentiation. Here, the expression levels of HMTs and HDMs were profiled in hDPCs undergoing odontogenic induction. Among several differentially expressed enzymes, HDM KDM5A demonstrated significantly enhanced expression during cytodifferentiation. Furthermore, KDM5A expression increased during early passages and in a time-dependent manner during odontogenic induction. Using a shRNA-expressing lentivirus, KDM5A was knocked down in hDPCs. KDM5A depletion resulted in greater alkaline phosphatase activity and more mineral deposition formation. Meanwhile, the expression levels of the odontogenic markers DMP1, DSPP, OSX, and OCN were increased by KDM5A knockdown. As a histone demethylase specific for tri- and dimethylated histone H3 at lysine 4 (H3K4me3/me2), KDM5A deficiency led to a significant increment in total H3K4me3 levels, whereas no significant difference was found for H3K4 me2. H3K4me3 levels on the promoters of the odontogenic markers increased after KDM5A knockdown in hDPCs. These results demonstrated that KDM5A is present in hDPCs and inhibits the odontogenic differentiation potentiality of hDPCs by removing H3K4me3 from specific gene promoters, suggesting that KDM5A-dependent histone demethylation may play an important role in reparative dentinogenesis.

2.
BMC Oral Health ; 20(1): 9, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31914978

RESUMO

BACKGROUND: This study sought to evaluate dental utilization among 3-,4-, and 5-year-old children in China and to use Andersen's behavioural model to explore influencing factors, thereby providing a reference for future policy making. METHODS: This study is a cross-sectional study. Data of 40,305 children aged 3-5 years were extracted from the Fourth National Oral Health Survey, which was performed from August 2015 to December 2016. Patient data were collected using a questionnaire, which was answered by the child's parents, and clinical data were collected during a clinical examination. Stratification and survey weighting were incorporated into the complex survey design. Descriptive statistics, bivariate correlations and hierarchical logistic regression results were then analysed to find the factors associated with oral health service utilization. RESULTS: The oral health service utilization prevalence during the prior 12 months were 9.5% (95%CI: 8.1-11.1%) among 3-year-old children, 12.1% (95%CI: 10.8-13.5%) among 4-year-old children, and 17.5% (95%CI: 15.6-19.4%) among 5-year-old children. "No dental diseases" (71.3%) and "dental disease was not severe" (12.4%) were the principal reasons why children had not attended a dental visit in the past 12 months. The children whose parents had a bachelor's degree or higher (OR: 2.29, 95%CI: 1.97-2.67, p < 0.001), a better oral health attitude ranging from 5 to 8(OR: 1.64, 95%CI: 1.43-1.89, p < 0.001), annual per capital income more than 25,000 CNY (OR: 1.40, 95%CI: 1.18-1.65, p < 0.001),think their child have worse or bad oral health (OR: 3.54, 95%CI: 2.84-4.40, p < 0.001), and children who often have toothaches (OR: 9.72, 95%CI: 7.81-12.09, p < 0.001) were more likely to go to the dentist in the past year. CONCLUSION: The prevalence of dental service utilization was relatively low among preschool children. It is necessary to strengthen oral health education for parents and children, thereby improving oral health knowledge as well as attitude, and promoting dental utilization.

3.
Community Dent Oral Epidemiol ; 48(1): 32-41, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31621099

RESUMO

OBJECTIVES: To explore the factors associated with utilization of oral health services among Chinese adults and older adults according to the Andersen Behavior Model. METHODS: Data from the 4th National Oral Health Survey (2015-2016) in China were used. A total of 7206 people (3669 adults aged 35-44 years and 3537 older adults aged 65-74 years) were included in our analysis. Oral health service utilization in the past 12 months was the outcome variable. Explanatory variables were selected according to the Andersen Behavior Model. Descriptive statistics and bivariate associations (chi-square tests) were analysed, followed by hierarchical Poisson regression models, which were conducted to determine the factors associated with oral health service utilization. RESULTS: In total, 21.4% (95% CI: 19.4%-23.7%) of adults (35-44 years old) and 20.7% (95% CI: 18.6%-22.9%) of older adults (65-74 years old) utilized oral health services in the past 12 months. Nearly 80% of adults (78.7%, 95% CI: 74.0%-82.7%) and more than 90% of older adults (93.7%, 95% CI: 91.0%-95.6%) visited a dentist for treatment. Adults aged 35-44 years old who were female (IRR: 1.15, 95% CI: 1.00-1.33, P = .047), had good oral health knowledge and attitudes (IRR: 1.30, 95% CI: 1.06-1.59, P = .011), perceived their oral health status as fair (IRR:1.51, 95% CI:1.24-1.85, P < .001) or poor/very poor (IRR:2.52, 95% CI:2.01-3.18, P < .001) and had a decayed, missing and filled teeth (DMFT) index >0 (IRR: 1.52, 95% CI: 1.11-2.09, P = .009) were more likely to report dental visits in the past 12 months. Older adults who utilized oral health services tended to be female (IRR: 1.32, 95% CI: 1.09-1.59, P = .004); to be covered by Urban Resident Basic Medical Insurance (URBMI) (IRR: 1.56, 95% CI: 1.18-2.05, P = .002), Urban Employee Basic Medical Insurance (UEBMI) (IRR: 1.69, 95% CI: 1.32-2.16, P < .001) or government medical insurance (GMI) (IRR: 1.03, 95% CI:1.01-2.16, P = .044); to have a high education level (IRR: 1.37, 95% CI: 1.08-1.74, P = .010); to have an income level in the 2nd tertile (IRR: 1.44, 95% CI: 1.13-1.84, P = .003) or 3rd tertile (IRR:1.52, 95% CI:1.18-1.95, P = .001); and to perceive their oral health status as poor or very poor (IRR: 1.53, 95% CI: 1.21-1.95, P = .001). CONCLUSIONS: Sex and self-perceived oral health status were associated with oral health utilization among Chinese population. Additionally, for older adults, education level, household income and insurance coverage were determinants of dental service use. These findings can aid in creating more targeted policies to increase the use of dental services by Chinese adults.

4.
Arch Oral Biol ; 111: 104637, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31884335

RESUMO

OBJECTIVE: The aim of this study was to evaluate whether individual genetic factors involved in amelogenesis, the immune response and water channel proteins may increase the susceptibility to Molar-Incisor Hypomineralization (MIH) in Chinese children. DESIGN: DNA samples were collected from 86 cases with MIH cases and 344 controls. Sixteen single-nucleotide polymorphisms (SNPs) were investigated. Logistic regression analysis was performed to assess association between SNPs and the risk of MIH. RESULTS: Our results showed that the risk of MIH in the rs13115627-AA genotype carriers and the rs1784418-TT genotype carriers were significantly higher than that among those with the rs13115627-GG genotype (OR (95 % CI)) = 4.942 (0.658-37.131) and the rs1784418-CT genotype (OR (95 % CI)) = 2.023 (1.63-3.521). The population with the rs1800972-CC genotype and the rs1800972-C allele had a higher risk to develop MIH, OR (95 % CI) = 2.284 (1.267-4.115), OR (95 % CI) = 2.427 (1.493-3.953) respectively. In the Aquaporin 5(AQP5) gene, we individually analyzed two SNPs, rs1996315 and rs923911. We found no significant associations between them and MIH. However, in the analysis of the gene-gene interactions, we discovered a significant two-locus model (P = 0.023) involving rs1996315 and rs923911. Participants with the rs1996315-AG and rs923911-AC genotypes had the highest MIH risk, compared to participants with the rs1996315-GG and rs923911-CC genotypes, OR (95 % CI) = 3.603 (1.147-11.318). CONCLUSION: This study showed that genetic variants in the AMBN, MMP20 and DEFB1 genes may contribute to MIH in the permanent dentition of children. Moreover, interactions among AQP5 gene may also increase the MIH susceptibility.


Assuntos
Aquaporina 5/genética , Hipoplasia do Esmalte Dentário/genética , Incisivo , Dente Molar , Amelogênese , Estudos de Casos e Controles , Criança , Proteínas do Esmalte Dentário , Humanos , Polimorfismo de Nucleotídeo Único , Prevalência , beta-Defensinas
5.
Microbiologyopen ; 8(12): e937, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31560838

RESUMO

Streptococcus mutans and Candida albicans are often isolated from plaques associated with early childhood caries. However, there are limited studies examining how these microorganisms interact with one another and how best to manage them. Recent studies have shown that curcumin (CUR), a natural compound, has the potential to independently control both of these microorganisms. The purpose of this study was to investigate how S. mutans and C. albicans respond in mono- and dual-species biofilms challenged with CUR. Quantitative biofilm biomass and viability were first evaluated and supported by live-dead PCR to assess biofilm composition. Confocal laser scanning microscopy (CLSM) was used to evaluate the exopolysaccharide (EPS) content and thickness of the biofilms, and the structure of the biofilms and morphology of the cells were observed by scanning electron microscopy (SEM). Quantitative real-time PCR (qRT-PCR) was applied to assess relative gene expression. The 50% minimum biofilm eradication concentration (MBEC50 ) of CUR against S. mutans and C. albicans was 0.5 mM. The biomass and viability decreased after treatment with CUR both in dual-species biofilms and in mono-species biofilm. CUR inhibited S. mutans and C. albicans in both mono- and dual-species biofilms. Streptococcus mutans was more sensitive to CUR in dual-species biofilm than in mono-species biofilms, whereas C. albicans was less sensitive in dual-species biofilms. EPS production was decreased by CUR in both mono- and dual-species biofilms, which coincided with the downregulation of glucosyltransferase and quorum sensing-related gene expression of S. mutans. In C. albicans, the agglutinin-like sequence family of C. albicans was also downregulated in dual-species biofilms. Collectively, these data show the potential benefit of using a natural antimicrobial, CUR, to control caries-related dual-species plaque biofilms.

6.
Curr Microbiol ; 76(11): 1238-1246, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31377819

RESUMO

Streptococcus mutans (S. mutans) adheres to the tooth surface, metabolizes carbohydrates, and produces acid products, leading to enamel demineralization-the onset of dental caries. Rapid acidification by S. mutans has been observed in the presence of glucose. However, little is known about the role of small RNAs (sRNAs) in S. mutans in the presence of glucose and their relationship to tooth adherence. The objective of this study was to evaluate the role of sRNAs in S. mutans (18-50 nucleotides) regarding adherence capacity under 1% and 5% glucose concentrations. The pH drop and adherence capacity in the 1% glucose condition were similar to these parameters under conditions of 5% sucrose that were published in our previous study. A total of 2149 candidate sRNA with at least 100 average reads in the 5% and 1% glucose libraries were obtained. Between the two libraries, 581 sRNAs were differentially expressed and 43 sRNAs were verified. However, the expression levels of the predicted target genes gtfC and spaP were similar between the 1% and 5% glucose conditions. The bioinformatic analysis suggested that differentially expressed sRNAs may be involved in several pathways. These findings indicate that sRNAs were induced under these glucose concentrations and a series of sRNAs were specifically induced, respectively. sRNAs that are induced under glucose stress may be involved in regulating adherence of S. mutans.


Assuntos
Aderência Bacteriana , Glucose/análise , RNA Bacteriano/metabolismo , Streptococcus mutans/fisiologia , Cárie Dentária/microbiologia , Regulação Bacteriana da Expressão Gênica , Glucose/metabolismo , Humanos , RNA Bacteriano/genética , Streptococcus mutans/genética , Streptococcus mutans/crescimento & desenvolvimento , Sacarose/metabolismo
7.
AMB Express ; 9(1): 31, 2019 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-30820691

RESUMO

There are signs that amyloid fibers exist in Streptococcus mutans biofilm recently. However, the characteristics of amyloid fibers and fibrillation influencing factors are unknown. In this study, we firstly used transmission electron microscopy (TEM) and atomic force microscopy (AFM) to observe the morphology of amyloid fibers in S. mutans. Then the extracted amyloid fibers from biofilm were studied for their characteristics. Further, the influencing factors, PH, temperature and eDNA, were investigated. Results showed there were mainly two morphologies of amyloid fibers in S. mutans, different in width. Amyloid fibers inhibitor-EGCG obviously destroyed biofilm at different stages, which is dose-dependent. The amount of amyloid fibers positively correlated with biofilm biomass in clinical isolates. Acidic pH and high temperature obviously accelerated amyloid fibrillation. During amyloid fibrillation, amyloid growth morphologies were observed by TEM and results showed two growth morphologies. Amyloid fibers formed complex with eDNA, which we call (a)eDNA. The molecular weight of (a)eDNA was similar to genomic DNA, greatly larger than that of eDNA in matrix. Combined use of DNase I and EGCG was more efficiently in inhibiting amyloid fibers and biofilm biomass. In conclusion, amyloid fibers are the crucial structures for S. mutans biofilm formation, showing two types of morphology. Acidic pH and temperature can obviously accelerate amyloid fibrillation. Amyloid fibers form complex with (a)eDNA and combined use of DNase and amyloid fiber inhibitor is more efficiently in inhibiting S. mutans biofilm formation.

8.
Front Microbiol ; 9: 1498, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30083138

RESUMO

Aim: The purpose of this study was to investigate strain dependent differences of the cariogenic biofilm forming Streptococcus mutans within both simple and complex communities. Methods: A mono-species containing representative S. mutans clinical isolates (caries and non-caries), and a multispecies in vitro caries biofilm model containing Lactobacillus casei, Veillonella dispar, Fusobacterium nucleatum and Actinomyces naeslundii, and either of two representative S. mutans clinical isolates (caries and non-caries), was developed as a comparison model. Compositional analysis of total and live bacteria within biofilms, and transcriptional analysis of biofilm associated virulence factors were evaluated by live/dead PCR and quantitative PCR, respectively. Scanning electron microscopy (SEM) was used to analyze the architecture of biofilm. One-way analysis of variance and t-tests were used to investigate significant differences between independent groups of data. Results: Within a mono-species biofilm, different S. mutans strains responded similarly to one another during biofilm formation in different carbohydrate sources, with sucrose showing the highest levels of biofilm biomass and galactose showing the lowest. Within the polymicrobial biofilm system, compositional analysis of the bacteria within the biofilm showed that S. mutans derived from a caries-free patient was preferentially composed of both total and viable L. casei, whereas S. mutans derived from a caries patient was dominated by both total and viable S. mutans (p < 0.001). Normalized gene expression analysis of srtA, gtfB, ftf, spaP, gbpB, and luxS, showed a general upregulation within the S. mutans dominant biofilm. Conclusion: We were able to demonstrate that individual strains derived from different patients exhibited altered biofilm characteristics, which were not obvious within a simple mono-species biofilm model. Influencing the environmental conditions changed the composition and functionality S. mutans within the polymicrobial biofilm. The biofilm model described herein provides a novel and reproducible method of assessing the impact on the biofilm microbiome upon different environmental influences.

9.
Biomed Res Int ; 2018: 4508709, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29682545

RESUMO

Streptococcus mutans (S. mutans) has been proved to be the main aetiological factor in dental caries. Curcumin, a natural product, has been shown to exhibit therapeutic antibacterial activity, suggesting that curcumin may be of clinical interest. The objective of this study is to evaluate the inhibitory effects of curcumin on metabolism and biofilm formation in S. mutans using a vitro biofilm model in an artificial oral environment. S. mutans biofilms were treated with varying concentrations of curcumin. The biofilm metabolism and biofilm biomass were assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and the crystal violet assay. Confocal laser scanning microscopy was used to analyse the composition and extracellular polysaccharide content of S. mutans biofilm after curcumin treatment. The biofilm structure was evaluated using a scanning electron microscope. The gene expression of virulence-related factors was assessed by real-time PCR. The antibiofilm effect of curcumin was compared with that of chlorhexidine. The sessile minimum inhibitory concentration (SMIC50%) of curcumin against S. mutans biofilm was 500 µM. Curcumin reduced the biofilm metabolism from 5 min to 24 h. Curcumin inhibited the quantity of live bacteria and total bacteria in both the short term (5 min) and the long term. Moreover, curcumin decreased the production of extracellular polysaccharide in the short term. The expression of genes related to extracellular polysaccharide synthesis, carbohydrate metabolism, adherence, and the two-component transduction system decreased after curcumin treatment. The chlorhexidine-treated group showed similar results. We speculate that curcumin has the capacity to be developed as an alternative agent with the potential to reduce the pathogenic traits of S. mutans biofilm.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Curcumina/farmacologia , Streptococcus mutans/efeitos dos fármacos , Clorexidina/farmacologia , Cárie Dentária/microbiologia , Testes de Sensibilidade Microbiana/métodos , Microscopia Confocal/métodos , Fatores de Virulência/metabolismo
10.
J Med Microbiol ; 67(5): 641-651, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29595415

RESUMO

PURPOSE: Adherence capacity is one of the principal virulence factors of Streptococcus mutans, and adhesion virulence factors are controlled by small RNAs (sRNAs) at the post-transcriptional level in various bacteria. Here, we aimed to identify and decipher putative adhesion-related sRNAs in clinical strains of S. mutans. METHODOLOGY: RNA deep-sequencing was performed to identify potential sRNAs under different adhesion conditions. The expression of sRNAs was analysed by quantitative real-time PCR (qRT-PCR), and bioinformatic methods were used to predict the functional characteristics of sRNAs. RESULTS: A total of 736 differentially expressed candidate sRNAs were predicted, and these included 352 sRNAs located on the antisense to mRNA (AM) and 384 sRNAs in intergenic regions (IGRs). The top 7 differentially expressed sRNAs were successfully validated by qRT-PCR in UA159, and 2 of these were further confirmed in 100 clinical isolates. Moreover, the sequences of two sRNAs were conserved in other Streptococcus species, indicating a conserved role in such closely related species. A good correlation between the expression of sRNAs and the adhesion of 100 clinical strains was observed, which, combined with GO and KEGG, provides a perspective for the comprehension of sRNA function annotation. CONCLUSION: This study revealed a multitude of novel putative adhesion-related sRNAs in S. mutans and contributed to a better understanding of information concerning the transcriptional regulation of adhesion in S. mutans.


Assuntos
Aderência Bacteriana , Pequeno RNA não Traduzido/análise , Streptococcus mutans/genética , Streptococcus mutans/fisiologia , Criança , Biologia Computacional , Cárie Dentária/microbiologia , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Pequeno RNA não Traduzido/genética , Reação em Cadeia da Polimerase em Tempo Real , Streptococcus mutans/isolamento & purificação
11.
Caries Res ; 52(3): 230-245, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29353283

RESUMO

Research on the association between dental caries and body mass index (BMI) in children has shown contradictory results; thus we aimed to examine the association between dental caries and the full range of BMI classes among children. We comprehensively searched PubMed, Embase, and the Cochrane Library for studies published prior to March 2017. Articles comparing dental caries among the full range of BMI classes for children below 18 years of both genders were included. Fourteen studies were eligible for this study. Basic information - i.e., first author, published year, study design, country, sample size, age, type of dental caries index and BMI, main results and conclusions, and means and standard deviations of the dental caries indexes used - was pooled. The weighted mean differences and corresponding 95% confidence intervals for dental caries between children with abnormal weight and those with normal weight were analyzed. Generally, no significant differences in caries were found between any abnormal-weight group and the normal-weight group for both primary and permanent teeth. Sensitivity analyses showed that the obese group had more caries than the normal-weight group in their primary teeth. Significantly more caries was found among the overweight and obese children in both primary and permanent teeth in high-income countries, but not in low- and middle-income countries. We recommend that further studies use suitable sample sizes, unify the criteria for BMI categorization and the dental caries index, and investigate the confounding factors that might influence dental caries and BMI.


Assuntos
Índice de Massa Corporal , Cárie Dentária/etiologia , Criança , Humanos , Obesidade Pediátrica/complicações , Fatores de Risco
12.
Front Physiol ; 8: 851, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29163197

RESUMO

Genetic studies have shown that variations in enamel formation genes are associated with caries susceptibility. The aim of this study was to test in vitro whether variants in these genes are associated with dental enamel demineralization in a Streptococcus mutans biofilm model. DNA and enamel samples were obtained from 213 individuals. DNA was extracted from saliva, and 16 single nucleotide polymorphisms were analyzed. The physical and chemical properties of sound enamel samples and the mineral loss and the lesion depth of the demineralized enamel samples under cariogenic challenge were analyzed. Microhardness, enamel chemicals, mineral loss and demineralization depth were compared between different genotypes at each single nucleotide polymorphism. The GG genotype of TUFT1 (rs17640579) and the GT genotype of MMP20 (rs1612069) exhibited increased microhardness (p = 0.044 and 0.016, respectively). The GG genotype of AMBN (rs7694409) had a higher magnesium level, while the CT genotype of TFIP11 (rs2097470) had a lower magnesium level (p = 0.044 and 0.046, respectively). The GT genotype of MMP20 (rs1612069) had a higher calcium level (p = 0.034). The GG genotype of AMBN (rs13115627), the AG genotype of ENAM (rs12640848) and the AA genotype of MMP20 (rs2292730) had a lower phosphorus level (p = 0.012, 0.006, and 0.023, respectively). The GG genotype of AMBN (rs13115627) was also associated with a higher calcium-phosphorus ratio (p = 0.034). Individuals with the CC genotype of TFIP11 (rs134143) exhibited significantly more mineral loss (p = 0.011) and a deeper lesions (p = 0.042). Individuals with the TT genotype of TFIP11 (rs2097470) had more mineral loss (p = 0.018). Individuals with the GG genotype of TUFT1 (rs17640579) exhibited a shallower demineralization depth (p = 0.047). Individuals with the GT genotype of MMP20 (rs1612069) exhibited a shallower demineralization depth (p = 0.042). Individuals with the GG genotype of ENAM (rs12640848) exhibited less mineral loss (p = 0.01) and a shallower demineralization depth (p = 0.03). Genetic variations in TFIP11, TUFT1, MMP20, and ENAM influenced enamel demineralization in a Streptococcus mutans biofilm model.

13.
Mol Med Rep ; 16(6): 9242-9250, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29039505

RESUMO

Streptococcus mutans is a cariogenic bacterium that contributes to dental caries due to its ability to produce lactic acid, which acidifies the local environment. The potential of S. mutans to respond to environmental stress and tolerate low pH is essential for its survival and predominance in caries lesions. Small noncoding RNAs (sRNAs) have been reported to be involved in bacterial stress and virulence. Few studies have investigated the sRNAs of S. mutans and the function of these sRNAs remains to be elucidated. In the present study, the association between sRNA133474 and acid tolerance, including potential underlying mechanisms, were investigated within clinical strains of S. mutans. From pediatric dental plaques, 20 strains of S. mutans were isolated. An acid killing assay was performed to analyze acid tolerance of S. mutans. Expression patterns of sRNA133474 were investigated during various growth phases under various acidic conditions via reverse transcription­quantitative polymerase chain reaction. RNA predator and Kyoto Encyclopedia of Genes and Genomes analyses were performed to predict target mRNAs of sRNA133474 and to examine the involvement of putative pathways of target mRNAs, respectively. The results of the present study demonstrated that sRNA133474 activity was growth phase­dependent, and two distinct expression patterns were identified in 10 clinical strains. At pH 5.5 and 7.5 the expression levels of sRNA133474 were significantly different, and high­acid tolerant strains exhibited reduced expression levels of sRNA133474 compared with low­acid tolerant strains. A correlation between sRNA133474 expression levels and acid tolerance was observed in 20 clinical isolates of S. mutans (r=­0.6298, P<0.01). Finally, five target mRNAs (liaS, liaR, comE, covR and ciaR) involved in the two­component system (TCS) were selected for further evaluation; the expression levels of three target mRNAs (liaR, ciaR and covR) were negatively correlated with sRNA133474 expression levels. In conclusion, the results of the present study suggested that S. mutans may utilize sRNA133474 to orchestrate TCSs for optimal adaption to acidic pH in clinical strains.


Assuntos
Adaptação Biológica/genética , Concentração de Íons de Hidrogênio , RNA Bacteriano , Pequeno RNA não Traduzido/genética , Infecções Estreptocócicas/microbiologia , Streptococcus mutans/genética , Streptococcus mutans/metabolismo , Biomarcadores , Criança , Pré-Escolar , Biologia Computacional/métodos , Cárie Dentária/microbiologia , Cárie Dentária/prevenção & controle , Placa Dentária/microbiologia , Regulação Bacteriana da Expressão Gênica , Humanos , Streptococcus mutans/isolamento & purificação
14.
BMC Oral Health ; 17(1): 114, 2017 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-28705197

RESUMO

BACKGROUND: To explore and analyse the association between biofilm and the genetic polymorphisms of scrA gene of EnzymeIIscr found in clinical isolates of Streptococcus mutans (S. mutans) from severe early childhood caries (S-ECC) in 3 years old children. METHODS: Clinical strains of S. mutans were conserved from a previous study. Thirty strains of S. mutans from the S-ECC group and 30 strains of S. mutans from the caries free (CF) group were selected. Biomass and viability of biofilm formed by the strains were evaluated by crystal violet and alamar blue assay. Genomic DNA was extracted from the S. mutans isolates. PCR was conducted to amplify scrA gene. After purified and sequenced the PCR products, BioEdit sofeware was used to analyse the sequence results. A chi-square test was used to compare the results. RESULTS: Compared to the CF group, the biomass of S-ECC group was higher (P = 0.0424). However, the viability of the two groups showed no significant difference. All 60 clinically isolated S. mutans strains had a 1995 base pair (bp) scrA gene. Forty-nine point mutations were identified in scrA from the 60 clinical isolates. There were 17 missense point mutations at the 10, 65, 103, 284, 289, 925, 1444, 1487, 1494, 1508, 1553, 1576, 1786, 1822, 1863, 1886, and 1925 bp positions. The other 32 mutations were silent point mutations. No positions were found at active sites of ScrA. The statistic analyse showed no significant missense mutation rates between the two groups. CONCLUSIONS: There was no association between biofilm and genetic polymorphisms of scrA from S. mutans with S-ECC in 3 years old children.


Assuntos
Biofilmes , Cárie Dentária/microbiologia , Genes Bacterianos/genética , Streptococcus mutans/genética , Biofilmes/crescimento & desenvolvimento , Estudos de Casos e Controles , Pré-Escolar , DNA Bacteriano/genética , Humanos , Mutação de Sentido Incorreto/genética , Reação em Cadeia da Polimerase , Polimorfismo Genético/genética , Mutação Silenciosa/genética , Streptococcus mutans/isolamento & purificação
15.
Int J Mol Sci ; 17(9)2016 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-27649155

RESUMO

Streptococcus mutans (S. mutans) is the major clinical pathogen responsible for dental caries. Its acid tolerance has been identified as a significant virulence factor for its survival and cariogenicity in acidic conditions. Small RNAs (sRNAs) are recognized as key regulators of virulence and stress adaptation. Here, we constructed three libraries of sRNAs with small size exposed to acidic conditions for the first time, followed by verification using qRT-PCR. The levels of two sRNAs and target genes predicted to be bioinformatically related to acid tolerance were further evaluated under different acid stress conditions (pH 7.5, 6.5, 5.5, and 4.5) at three time points (0.5, 1, and 2 h). Meanwhile, bacterial growth characteristics and vitality were assessed. We obtained 1879 sRNAs with read counts of at least 100. One hundred and ten sRNAs were perfectly mapped to reported msRNAs in S. mutans. Ten out of 18 sRNAs were validated by qRT-PCR. The survival of bacteria declined as the acid was increased from pH 7.5 to 4.5 at each time point. The bacteria can proliferate under each pH except pH 4.5 with time. The levels of sRNAs gradually decreased from pH 7.5 to 5.5, and slightly increased in pH 4.5; however, the expression levels of target mRNAs were up-regulated in acidic conditions than in pH 7.5. These results indicate that some sRNAs are specially induced at acid stress conditions, involving acid adaptation, and provide a new insight into exploring the complex acid tolerance for S. mutans.


Assuntos
Cárie Dentária/prevenção & controle , RNA Bacteriano/genética , Pequeno RNA não Traduzido/genética , Streptococcus mutans/genética , Ácidos/química , Proteínas de Bactérias/genética , Cárie Dentária/microbiologia , Pesquisa em Odontologia/métodos , Biblioteca Gênica , Humanos , Concentração de Íons de Hidrogênio , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Streptococcus mutans/crescimento & desenvolvimento , Streptococcus mutans/patogenicidade , Virulência/genética
16.
Arch Oral Biol ; 58(9): 1129-38, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23664249

RESUMO

OBJECTIVE: To monitor the longitudinal changes in oral microbial diversity of children with severe early childhood caries (S-ECC) compared to caries free (CF) controls. METHODS: Dental plaque samples of 12 children in each group at 8, 14, 20, 26 and 32 months of age were analysed. Total microbial genomic DNA was isolated from each sample, and PCR-denaturing gradient gel electrophoresis (DGGE) analyses were carried out. RESULTS: The number of bands was significantly higher in the CF group (18.17±4.91 bands) than in the S-ECC group (14.54±5.56 bands) at 32 months of age (P<0.05). A total of 21 genera were identified in all subjects, and there were no significant differences between the two groups at genus level. DGGE profiles showed that most of the clusters were constructed from one individual over time in the both groups. CONCLUSIONS: The onset of S-ECC is accompanied by a decrease in microbial diversity. The overall composition of the microbiota is highly similar within an individual over time.


Assuntos
DNA Bacteriano/genética , Cárie Dentária/microbiologia , Placa Dentária/microbiologia , Microbiota/genética , Análise de Variância , Pré-Escolar , Estudos de Coortes , Eletroforese em Gel de Gradiente Desnaturante/métodos , Cárie Dentária/diagnóstico , Feminino , Humanos , Lactente , Estudos Longitudinais , Masculino , Reação em Cadeia da Polimerase/métodos , RNA Ribossômico 16S
17.
Int J Paediatr Dent ; 21(1): 58-67, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20731736

RESUMO

BACKGROUND: In China, there is a massive rural-urban migration and the children of migrants are often unregistered residents (a 'floating population'). AIM: This pilot study aimed to profile the oral health of migrant children in South China's principal city of migration and identify its socio-demographic/behavioural determinants. DESIGN: An epidemiological survey was conducted in an area of Guangzhou among 5-year-old migrant children (n = 138) who received oral examinations according to the World Health Organization criteria. Parents' oral health knowledge/attitude, child practices, and impact of children's oral health on their quality-of-life (QoL) were assessed. RESULTS: The caries rate and mean (SD) dmft were 86% and 5.17 (4.16), respectively, higher than those national statistics for both rural and urban areas (P < 0.05). Oral hygiene was satisfactory (DI-S < 1.0) in 3% of children. Oral health impacts on QoL were considerable; 60% reported one or more impacts. 58% variance in 'dmft' was explained by 'non-local-born', 'low-educated parents', 'bedtime feeding', 'parental unawareness of fluoride's effect and importance of teeth', and 'poor oral hygiene' (all P < 0.05). 'Non-local-born' and 'dmft' indicated poor oral health-related QoL (both P < 0.05), accounting for 32% of variance. CONCLUSION: Oral health is poor among rural-urban migrant children and requires effective interventions in targeted sub-groups.


Assuntos
Saúde da População Rural/estatística & dados numéricos , Doenças Dentárias/epidemiologia , Migrantes/estatística & dados numéricos , Atitude Frente a Saúde , Cariostáticos/uso terapêutico , Pré-Escolar , China/epidemiologia , Índice CPO , Assistência Odontológica/estatística & dados numéricos , Cárie Dentária/epidemiologia , Escolaridade , Estudos Epidemiológicos , Comportamento Alimentar , Feminino , Fluoretos/uso terapêutico , Comportamentos Relacionados com a Saúde , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Renda , Masculino , Índice de Higiene Oral , Relações Pais-Filho , Pais/educação , Projetos Piloto , Qualidade de Vida , Características de Residência , Classe Social , Escovação Dentária/estatística & dados numéricos , Saúde da População Urbana/estatística & dados numéricos
18.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 44(2): 82-4, 2009 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-19563039

RESUMO

OBJECTIVE: To explore the relationship between the concentrations of lactoferrin and lysozyme in saliva and dental caries in primary dentition among Chinese children. METHODS: Forty children with high dmft score (dmft > or = 5) and 40 caries-free children (dmft = 0) were sampled and assigned into two groups. Total salivary proteins was measured by means of bicinchoninic acid. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was performed to analyze the images of target straps. Lactoferrin and lysozyme were detected using Western blotting method. RESULTS: The total salivary protein in high dmft group [(852.02 +/- 206.14) mg/L] was lower than that of caries-free group [(1032.44 +/- 221.99) mg/L, P < 0.001]. The ratio of 77,000 protein in high dmft group [(12.50 +/- 7.73) IA/microg] was significantly higher than that of the caries-free children [(8.71 +/- 4.28) IA/microg, P = 0.009], while there was no significant difference for 14,500 protein between them (P = 0.137). The ratio of lactoferrin was higher in high dmft group [(229.04 +/- 197.14) IA/microg] than that in caries-free children [(144.07 +/- 99.91) IA/microg, P = 0.018], while no significant difference for lysozyme between the two groups (P = 0.091). CONCLUSIONS: Saliva protein is closely related to caries in primary dentition. Lactoferrin may be one of the important components.


Assuntos
Cárie Dentária/metabolismo , Lactoferrina/metabolismo , Muramidase/metabolismo , Saliva/química , Dente Decíduo , Estudos de Casos e Controles , Pré-Escolar , Cárie Dentária/epidemiologia , Feminino , Humanos , Masculino , Prevalência , Proteínas e Peptídeos Salivares
19.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 44(10): 611-3, 2009 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-20079308

RESUMO

OBJECTIVE: To investigate the prevalence and influencing factors of dental erosion among college students in Guangzhou and to provide necessary information for the prevention. METHODS: A total of 1704 16-24-year-old students from six colleges or universities were assessed for dental erosion. Data on the social economical status, eating habits, oral hygiene habits, and other related factors were obtained through questionnaire. The influencing factors were analyzed by chi(2)-test and logistic regression analysis. RESULTS: Five hundreds and one of the 1704 subjects suffered from dental erosion (29.4%). The teeth most frequently affected were the upper and lower incisors and first mandibular molar. For tooth surfaces were incisal/occlusal surfaces [66.1% (5491/8311)] and labial/buccal surfaces [31.0% (2574/8311)]. Logistic regression analysis showed that female, those who were not the only child in the family, and students who consumed carbonated drinks more than once per week or drank 500 ml or more of acidic beverages per week were more likely to have dental erosion. CONCLUSIONS: Control of the consuming of acidic beverages is an important measure for the prevention of dental erosion.


Assuntos
Erosão Dentária/epidemiologia , Adulto , China/epidemiologia , Estudos Transversais , Feminino , Humanos , Modelos Logísticos , Masculino , Prevalência
20.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 42(4): 219-22, 2007 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-17683669

RESUMO

OBJECTIVE: To isolate and identify Streptococcus mutans (Sm) and Streptococcus sobrinus (Ss) in dental plaque of children with high dmft and no caries by selective medium, biochemical methods and arbitrarily primed-polymerase chain reaction (AP-PCR). METHODS: A total of 401 3-4-year-old children from seven kindergartens were recruited using cluster sampling and their dental caries status were examined. From 30% of children with the highest dmft score (dmft >/= 5), 20 children were chosen randomly as test group and 20 age and gender-matched caries-free children were selected as control. Plaque samples were collected from buccal surfaces of the molars and plated onto TYCSB plate. Sm and Ss were primarily identified by colony morphology and biochemical characteristics. Then chromosomal DNA of the strains was isolated and Sm or Ss were confirmed by AP-PCR. RESULTS: The proportion positive for Sm and Ss in children with high dmft was 100% and 40% respectively while that in caries-free children was 75% and 5% by AP-PCR analysis. The differences were statistically significant between the two groups. CONCLUSIONS: The proportions positive for Sm and Ss detected by AP-PCR method were significantly higher in children with high dmft than in caries-free children and it is a risk factor for high dmft in deciduous teeth harboring Sm and Ss.


Assuntos
Cárie Dentária/microbiologia , Placa Dentária/microbiologia , Streptococcus mutans/isolamento & purificação , Streptococcus sobrinus/isolamento & purificação , Pré-Escolar , Feminino , Humanos , Masculino , Streptococcus mutans/genética , Streptococcus sobrinus/genética
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