scholarly journals QPCR Screening of Pediatric Saliva Samples to Evaluate Effects of Dental Sealants on Cariogenic Bacteria Streptococcus Mutans and Scardovia Wiggsiae

2021 ◽  
Vol 2 (1) ◽  
pp. 14-20
Author(s):  
Olivia Tsang ◽  
Kevin Major ◽  
Sonia Santoyo ◽  
Karl Kingsley ◽  
Linh Nguyen
Keyword(s):  
Dental Caries ◽  
Streptococcus Mutans ◽  
Bacterial Species ◽  
Conclusive Evidence ◽  
Oral Microbiota ◽  
Average Amount ◽  
Fluoride Treatment ◽  
Dental Sealants ◽  
Exact Effect ◽  
The Impact

Dental caries is an alarmingly prevalent multifactorial disease worldwide but is most common as a chronic disease among children and adolescents. Within the oral cavity there are hundreds bacterial species, including specific cariogenic pathogens such as Streptococcus mutans and Scardoviawiggsiae. Although dental caries are highly prevalent, it may also be preventable using methods such as dental sealants or fluoride treatment, which have proven to be highly effective in reducing caries risk – although there is limited evidence on the exact effect of these treatments on S. wiggsiaeinparticular. Due to the lack of conclusive evidence, this study is aimed to evaluate the microbial burden of S. mutans and S. wiggsiae among pediatric saliva samples to analyze the effects dental sealants have on these oral microbiota. Saliva samples derived from pediatric patients pre- and post-sealant were obtained from an existing repository. DNA was extracted and screened using qPCR and primers specific for the cariogenic organisms, S. mutans (SM) and S. wiggsiae (SW). These data demonstrated an overall reduction in SW among Post-sealant samples (11.14 U/uL) compared with Pre-sealant samples (11.68 U/uL), as well as a reduction in the overall number of samples harboring S. wiggsiae (n=8). The Pre-sealant average amount of SM (14.54 U/uL) was slightly increased among the Post-sealant samples (15.67 U/uL) with half of the samples analyzed (n=13) exhibiting slight increases in SM levels, and nearly one-third (n=8) exhibiting slight decreases in SM levels. The data from this study may suggest that dental sealants have an impact on certain cariogenic pathogens in the oral microbiota. Whether or not the impact is positive or not in light of the increase in S. mutans remains an observation that should be further analyzed. More research is required to address the limitations found in this study in order to localize the exact effect on the teeth with dental sealants.

scholarly journals THE IMPACT OF ASTHMAAND ITS MEDICATIONS ON DENTAL CARIES STATUS AND STREPTOCOCCUS MUTANS COUNT IN CHILDREN: A CROSS-SECTIONAL STUDY

2020 ◽  
pp. 20-23
Author(s):  
Sneha Upadhyay ◽  
Jyoti Bhavthankar ◽  
Mandakini Mandale ◽  
Nivedita Kaorey
Keyword(s):  
Dental Caries ◽  
Streptococcus Mutans ◽  
Cross Sectional Study ◽  
Control Group ◽  
Healthy Children ◽  
Sectional Study ◽  
Cross Sectional ◽  
Asthmatic Children ◽  
Significant Difference ◽  
The Impact

Background: Asthma and its medications have been linked to oral diseases in asthmatic children. Aim: Assessment of the dental caries status, salivary Streptococcus mutans count and S. mutans colony score in children receiving inhaled anti asthmatic medications and their comparison in healthy children Material and Method: A cross-sectional study was performed on 40 asthmatic children and 40 healthy children in the age group of 6-14 years. DMFT/deft indices were calculated and saliva samples were collected. Diluted saliva was inoculated on MSB agar plates. S. mutans count and colony score were analysed after 24-48 hours of inoculation. Results: Statistically significant difference was observed in the mean DMFT/deft index, salivary S. mutans load and S. mutans colony score in children of the asthmatic group and control group. Conclusion: Prevalence of dental caries and cariogenic bacteria is higher in asthmatic children.

scholarly journals NagR Differentially Regulates the Expression of theglmSandnagABGenes Required for Amino Sugar Metabolism by Streptococcus mutans

2015 ◽  
Vol 197 (22) ◽  
pp. 3533-3544 ◽  
Author(s):  
Lin Zeng ◽  
Robert A. Burne
Keyword(s):  
Dental Caries ◽  
Streptococcus Mutans ◽  
Bacterial Species ◽  
Random Mutagenesis ◽  
Sugar Metabolism ◽  
Amino Sugar ◽  
Binding Domain ◽  
Promoter Regions ◽  
Content Type ◽  
Effector Binding

ABSTRACTThe ability of bacteria to metabolize glucosamine (GlcN) andN-acetyl-d-glucosamine (GlcNAc) is considered important for persistent colonization of the oral cavity. In the dental caries pathogenStreptococcus mutans, the NagR protein regulates the expression ofglmS, which encodes a GlcN-6-P synthetase, andnagA(GlcNAc-6-P deacetylase) andnagB(GlcN-6-P deaminase), which are required for the catabolism of GlcNAc and GlcN. Two NagR-binding sites (dre) were identified in each of the promoter regions fornagBandglmS. Using promoter-reporter gene fusions, the role of eachdresite was examined in the regulation ofglmSandnagBpromoter activities in cells grown with glucose, GlcNAc, or GlcN. A synergistic relationship between the twodresites in theglmSpromoter that required proper spacing was observed, but that was not the case fornagB. Binding of purified NagR to DNA fragments from both promoter regions, as well as todresites alone, was strongly influenced by particular sugar phosphates. Using a random mutagenesis approach that targeted the effector-binding domain of NagR, mutants that displayed aberrant regulation of both theglmSandnagABgenes were identified. Collectively, these findings provide evidence that NagR is essential for regulation of genes for both the synthesis and catabolism of GlcN and GlcNAc inS. mutans, and that NagR engages differently with the target promoter regions in response to specific metabolites interacting with the effector-binding domain of NagR.IMPORTANCEGlucosamine andN-acetylglucosamine are among the most abundant naturally occurring sugars on the planet, and they are catabolized by many bacterial species as sources of carbon and nitrogen. Representing a group called lactic acid bacteria (LAB), the human dental caries pathogenStreptococcus mutansis shown to differ from known paradigm organisms in that it possesses a GntR/HutC-type regulator, NagR, that is required for the regulation of both catabolism of GlcN and biosynthesis. Results reported here reveal a simple and elegant mechanism whereby NagR differentially regulates two opposing biological processes by surveying metabolic intermediates. This study provides insights that may contribute to the development of novel therapeutic tools to combat dental caries and other infectious diseases.

scholarly journals Genotypic diversity of Streptococcus mutans isolated from preschoolers with and without early dental care

2019 ◽  
Vol 48 ◽  
Author(s):  
Ana Lídia Soares COTA ◽  
Janaína Accordi JUNKES ◽  
Regina Célia POLI-FREDERICO
Keyword(s):  
Dental Caries ◽  
Streptococcus Mutans ◽  
Dental Care ◽  
Random Amplified Polymorphic Dna ◽  
Genotypic Diversity ◽  
Caries Experience ◽  
Oral Microbiota ◽  
Preventive Program ◽  
Arbitrary Primers ◽  
History Of

Abstract Introduction Streptococcus mutans (S. mutans) exhibits extensive genotypic diversity, but the role of this variation is poorly understood. Objective To evaluate the genotypic diversity of S. mutans in preschoolers with and without early dental care and to associate it with dental caries experience. Material and method Twenty children, aged five year old, with history of dental care since they were one year old (G1) and 20 children without history of dental care (G2) were included. Their oral health status was assessed by the dmft index. S. mutans samples were isolated from the saliva and analysed by polymerase chain reaction. A total of 339 S. mutans isolates (173 from G1 and 166 from G2) were genotyped by random amplified polymorphic DNA with arbitrary primers OPA-02 and OPA-13. Result The results revealed 75 distinct genotypes of S. mutans in G1 and 73 in G2. Furthermore, G1 and G2 subjects harboured one to eight and one to seven distinct genotypes of S. mutans, respectively. A statistically significant association (P=0.021) and a moderate correlation (r= 0.503) were observed between dental caries experience and genotypic diversity of S. mutans in G1. Conclusion From the limitations of the study design, we just can hypothesize that actions of early dental care carried out by an educative-preventive program can contribute to a distinct oral microbiota.

scholarly journals Effect of Rubusoside, a Natural Sucrose Substitute, on Streptococcus mutans Biofilm Cariogenic Potential and Virulence Gene Expression In Vitro

2020 ◽  
Vol 86 (16) ◽  
Author(s):  
Chunru Guan ◽  
Faai Che ◽  
Huoxiang Zhou ◽  
Yiwei Li ◽  
Yaru Li ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dental Caries ◽  
Streptococcus Mutans ◽  
Virulence Genes ◽  
Virulence Gene ◽  
Extracellular Polysaccharides ◽  
Bacterial Viability ◽  
Content Type ◽  
Virulence Gene Expression ◽  
The Impact

ABSTRACT Dental caries is a biofilm-mediated disease in which Streptococcus mutans is the main pathogenic microorganism, and its incidence is closely related to sucrose. Rubusoside is a natural nonnutritive sweetener isolated from Rubus suavissimus S. Lee. This study was designed to determine the effect of this sucrose substitute on the cariogenic properties and virulence gene expression of S. mutans biofilms. S. mutans was exposed to brain heart infusion (BHI) medium (as a control), 1% sucrose-supplemented medium, 1% rubusoside-supplemented medium, and 1% xylitol-supplemented medium. The growth curve of the biofilm was monitored by crystal violet staining, and the pH was measured every 24 h. After 5 days, the biofilms formed on the glass coverslips were recovered to determine the biomass (dry weight and total amount of soluble proteins), numbers of CFU, and amounts of intra- and extracellular polysaccharides. Biofilm structural imaging was performed using a scanning electron microscope (SEM). Virulence gene expression (gtfB, gtfC, gtfD, ftf, spaP, gbpB, ldh, atpF, vicR, and comD) was determined by reverse transcription-quantitative PCR. Growth in rubusoside resulted in lower levels of acid production than observed during growth in sucrose, xylitol, and the control, while it also reduced the level of biofilm accumulation and bacterial viability and even reduced the level of production of extracellular polysaccharides. By SEM, the levels of biofilm formation and extracellular matrix during growth in rubusoside were lower than these levels during growth in sucrose and xylitol. From the perspective of virulence genes, growth in rubusoside and xylitol significantly inhibited the expression of virulence genes compared with their levels of expression after growth in sucrose. Among these genes, gtfB, gtfC, gbpB, ldh, and comD downregulation was found with growth in rubusoside compared with their expression with growth in xylitol. Therefore, rubusoside appears to be less potentially cariogenic than sucrose and xylitol and may become an effective sucrose substitute for caries prevention. Further studies are needed to deepen these findings. IMPORTANCE Dental caries is a major public health challenge and places heavy biological, social, and financial burdens on individuals and health care systems. To palliate the deleterious effect of sucrose on the virulence factors of S. mutans, massive commercial efforts have been oriented toward developing products that may act as sucrose substitutes. Rubusoside, a natural sucrose substitute, is a plant extract with a high level of sweetness. Although some studies have shown that rubusoside does not produce acids or inhibit the growth of S. mutans, little attention has been paid to its effect on dental biofilm and the underlying mechanisms. Our study focuses on the effect of rubusoside on the formation and structure of biofilms and the expression of virulence genes. The results confirm that rubusoside can inhibit accumulation, bacterial viability, polysaccharide production by the biofilm, and related gene expression. These results provide further insight into the cariogenicity of S. mutans biofilms and demonstrate a new perspective for studying the impact of sucrose substitutes on caries.

scholarly journals Association of Bitter Taste Receptor T2R38 Polymorphisms, Oral Microbiota, and Rheumatoid Arthritis

2021 ◽  
Vol 43 (3) ◽  
pp. 1460-1472
Author(s):  
Vivianne Cruz de Jesus ◽  
Manu Singh ◽  
Robert J. Schroth ◽  
Prashen Chelikani ◽  
Carol A. Hitchon
Keyword(s):  
Rheumatoid Arthritis ◽  
Relative Abundance ◽  
Bitter Taste ◽  
Bacterial Species ◽  
Taste Receptor ◽  
Oral Microbiome ◽  
Rrna Gene ◽  
Oral Microbiota ◽  
Microbial Composition ◽  
The Impact

The association of taste genetics and the oral microbiome in autoimmune diseases such as rheumatoid arthritis (RA) has not been reported. We explored a novel oral mucosal innate immune pathway involving the bitter taste G protein-coupled receptor T2R38. This case–control study aimed to evaluate whether T2R38 polymorphisms associate with the buccal microbial composition in RA. Genomic DNA was obtained from buccal swabs of 35 RA patients and 64 non-RA controls. TAS2R38 genotypes were determined by Sanger sequencing. The buccal microbiome was assessed by Illumina MiSeq sequencing of the V4-16S rRNA gene. Bacterial community differences were analyzed with alpha and beta diversity measures. Linear discriminant analysis effect size identified taxa discriminating between RA versus non-RA and across TAS2R38 genotypes. TAS2R38 genotype frequency was similar between RA and non-RA controls (PAV/PAV; PAV/AVI; AVI/AVI: RA 42.9%; 45.7%; 11.4% versus controls 32.8%; 48.4%; 18.8%, chi-square (2, N = 99) = 2.1, p = 0.35). The relative abundance of Porphyromonas, among others, differed between RA and non-RA controls. The relative abundance of several bacterial species also differed across TAS2R38 genotypes. These findings suggest an association between T2R38 polymorphisms and RA buccal microbial composition. However, further research is needed to understand the impact of T2R38 in oral health and RA development.

Effects of the Consumption of Probiotic Yogurt Containing Bifidobacterium lactis Bb12 on the Levels of Streptococcus mutans and Lactobacilli in Saliva of Students with Initial Stages of Dental Caries: A Double-Blind Randomized Controlled Trial

2019 ◽  
Vol 54 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Ahmad Zare Javid ◽  
Essam Amerian ◽  
Leila Basir ◽  
Alireza Ekrami ◽  
Mohammad Hosein Haghighizadeh ◽  
...  
Keyword(s):  
Dental Caries ◽  
Streptococcus Mutans ◽  
Saliva Sample ◽  
Intervention Group ◽  
Control Group ◽  
Controlled Clinical Trial ◽  
Oral Microbiota ◽  
Double Blind ◽  
Bifidobacterium Lactis ◽  
Probiotic Yogurt

Dental caries, caused by oral microbiota, is one of the most common human diseases. The present study aimed to investigate the effect of consumption of probiotic yogurt containing Bifidobacterium lactis Bb12 on salivary Streptococcus mutans and lactobacilli in students with initial stages of dental caries. In this double-blind randomized placebo-controlled clinical trial, 66 students (18–30 years) with initial stages of dental caries were selected and randomly assigned into 2 groups: the intervention group received 300 g/day of probiotic yogurt and the control group received 300 g/day of conventional yogurt for 2 weeks. An unstimulated fasting saliva sample was collected pre- and post-intervention. Bacterial counting was performed for salivary S. mutans and lactobacilli. A significant reduction in salivary S. mutans and lactobacillus counts was observed in the intervention group compared to their baseline and compared to the control group. In conclusion, it is suggested that the consumption of probiotic yogurt containing B. lactis Bb12 may modify the oral biofilm.

scholarly journals Characterization of a Type II-A CRISPR-Cas System in Streptococcus mutans

mSphere ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Cas Mosterd ◽  
Sylvain Moineau
Keyword(s):  
Streptococcus Mutans ◽  
Defense Mechanisms ◽  
Bacterial Species ◽  
Oral Microbiota ◽  
Type Ii ◽  
Content Type ◽  
C Terminus ◽  
Protospacer Adjacent Motif ◽  
Cas9 Protein

ABSTRACT Streptococcus mutans and its virulent phages are important members of the human oral microbiota. S. mutans is also the primary causal agent of dental caries. To survive in this ecological niche, S. mutans must encode phage defense mechanisms, which include CRISPR-Cas systems. Here, we describe the CRISPR-Cas type II-A system of S. mutans strain P42S, which was found to display natural adaptation and interference activity in response to phage infection and plasmid transformation. Newly acquired spacers were integrated both at the 5′ end of the CRISPR locus and ectopically. In comparisons of the cas genes of P42S to those of other strains of S. mutans, cas1, cas2, and csn2 appear to be highly conserved within the species. However, more diversity was observed with cas9. While the nuclease domains of S. mutans Cas9 (SmCas9) are conserved, the C terminus of the protein, including the protospacer adjacent motif (PAM) recognition domain, is less conserved. In support of these findings, we experimentally demonstrated that the PAMs associated with SmCas9 of strain P42S are NAA and NGAA. These PAMs are different from those previously reported for the CRISPR-Cas system of the model strain S. mutans UA159. This study illustrates the diversity of CRISPR-Cas type II-A systems that can be found within the same bacterial species. IMPORTANCE CRISPR-Cas is one of the mechanisms used by bacteria to defend against viral predation. Increasing our knowledge of the biology and diversity of CRISPR-Cas systems will also improve our understanding of virus-bacterium interactions. As CRISPR-Cas systems acquiring novel immunities under laboratory conditions are rare, Streptococcus mutans strain P42S provides an alternative model to study the adaptation step, which is still the least understood step in CRISPR-Cas biology. Furthermore, the availability of a natural Cas9 protein recognizing an AT-rich PAM opens up new avenues for genome editing purposes.

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