The rnc Gene Regulates the Microstructure of Exopolysaccharide in the Biofilm of Streptococcus mutans through the β-Monosaccharides

2021 ◽  
Vol 55 (5) ◽  
pp. 534-545
Author(s):  
Yangyu Lu ◽  
Hongyu Zhang ◽  
Meng Li ◽  
Mengying Mao ◽  
Jiaqi Song ◽  
...  
Keyword(s):  
Dental Caries ◽  
Streptococcus Mutans ◽  
Bacterial Adhesion ◽  
Extracellular Polysaccharide ◽  
Water Soluble ◽  
Glycosidic Bond ◽  
Glycosidic Bonds ◽  
Overexpression Strain ◽  
1H Nuclear Magnetic Resonance ◽  
Biofilm Development

Streptococcus mutans is known as the crucial pathogen of human dental caries, owing to its contribution to the biofilm development via the capacity of synthesizing exopolysaccharide (EPS), which mainly compose of α-glycosidic bond and β-glycosidic bond. β-glycosidic bond is less flexible than α-glycosidic bond because of differences between their configurational properties. Previous studies have shown that the rnc gene is implicated in the EPS formation and the cariogenicity of S. mutans. However, the effects of rnc on the microstructure of EPS have been not well-understood yet. Here, we further investigated how the rnc gene worked to modulate microstructural properties of the extracellular polysaccharide of S. mutans using glycomics methods. The gas chromatography-mass spectrometer showed that the proportion of glucose was decreased in water-soluble EPS and galactose was absent in water-insoluble EPS from the S. mutans rnc-deficient strain (Smurnc), compared with the isogenic wild-type strain (UA159). The composition of functional groups and the displacement of hydrogen bond were analyzed by infrared radiation and 1H nuclear magnetic resonance, respectively. In addition, phenotypic modulation of the biofilm matrix was assessed by microscopy. We found that the EPS of UA159 and the rnc overexpression strain (Smurnc+) mainly consisted of β-glycosidic bonds. Conversely, the EPS of Smurnc were made up of mostly α-glycosidic bonds, leading to the attenuation of biofilm biomass and bacterial adhesion. Furthermore, the existence of β-glycosidic bond was verified by enzyme digestion. Collectively, the rnc gene modulates the conversion of β-glycosidic bonds, which may play important roles in regulating the micromolecule structure of the EPS matrix, thus affecting the characteristics of S. mutans biofilm. These data illustrate that β-glycosidic bonds mediated by rnc may be potential targets for the prevention and treatment of dental caries.

scholarly journals Synergism of Streptococcus mutans and Candida albicans Reinforces Biofilm Maturation and Acidogenicity in Saliva: An In Vitro Study

2021 ◽  
Vol 10 ◽  
Author(s):  
Hye-Eun Kim ◽  
Yuan Liu ◽  
Atul Dhall ◽  
Marwa Bawazir ◽  
Hyun Koo ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Dental Caries ◽  
Streptococcus Mutans ◽  
Critical Role ◽  
In Vitro Study ◽  
Acidic Ph ◽  
Acidic Environment ◽  
Symbiotic Interaction ◽  
Biofilm Development

Early childhood caries, a virulent-form of dental caries, is painful, difficult, and costly to treat that has been associated with high levels of Streptococcus mutans (Sm) and Candida albicans (Ca) in plaque-biofilms on teeth. These microorganisms appear to develop a symbiotic cross-kingdom interaction that amplifies the virulence of plaque-biofilms. Although biofilm studies reveal synergistic bacterial-fungal association, how these organisms modulate cross-kingdom biofilm formation and enhance its virulence in the presence of saliva remain largely unknown. Here, we compared the properties of Sm and Sm-Ca biofilms cultured in saliva by examining the biofilm structural organization and capability to sustain an acidic pH environment conducive to enamel demineralization. Intriguingly, Sm-Ca biofilm is rapidly matured and maintained acidic pH-values (~4.3), while Sm biofilm development was retarded and failed to create an acidic environment when cultured in saliva. In turn, the human enamel slab surface was severely demineralized by Sm-Ca biofilms, while there was minimal damage to the enamel surface by Sm biofilm. Interestingly, Sm-Ca biofilms exhibited an acidic environment regardless of their hyphal formation ability. Our data reveal the critical role of symbiotic interaction between S. mutans and C. albicans in human saliva in the context of pathogenesis of dental caries, which may explain how the cross-kingdom interaction contributes to enhanced virulence of plaque-biofilm in the oral cavity.

scholarly journals Suppressive Effects of Octyl Gallate on Streptococcus mutans Biofilm Formation, Acidogenicity, and Gene Expression

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3170 ◽  
Author(s):  
Vika Gabe ◽  
Tomas Kacergius ◽  
Saleh Abu-Lafi ◽  
Mouhammad Zeidan ◽  
Basheer Abu-Farich ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dental Caries ◽  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Colorimetric Method ◽  
Solid Surfaces ◽  
Dependent Manner ◽  
Oral Diseases ◽  
Expression Change ◽  
Biofilm Development

The accumulation of biofilm by Streptococcus mutans bacteria on hard tooth tissues leads to dental caries, which remains one of the most prevalent oral diseases. Hence, the development of new antibiofilm agents is of critical importance. The current study reports the results from testing the effectiveness of octyl gallate (C8-OG) against: (1) S. mutans biofilm formation on solid surfaces (polystyrene, glass), (2) acidogenicity, (3) and the expression of biofilm-related genes. The amount of biofilm formed by S. mutans bacteria was evaluated using the colorimetric method and optical profilometry. The pH of the biofilm growth medium was measured with microelectrode. A quantitative reverse transcription-polymerase chain reaction (RT-qPCR) was used to assess the expression of genes encoding glucan binding protein B (gbpB), glucosyltransferases B, -C, -D (gtfB, -C, -D), and the F-ATPase β subunit of the F1 protein (atpD). The results show that C8-OG significantly diminished biofilm formation by exposed S. mutans on solid surfaces and suppressed acidogenicity in a dose-dependent manner, compared to unexposed bacteria (p < 0.05). The C8-OG concentration of 100.24 µM inhibited S. mutans biofilm development on solid surfaces by 100% and prevented a decrease in pH levels by 99%. In addition, the RT-qPCR data demonstrate that the biofilm-producing bacteria treated with C8-OG underwent a significant reduction in gene expression in the case of the four genes under study (gbpB, gtfC, gtfD, and atpD), and there was a slight decrease in expression of the gtfB gene. However, C8-OG treatments did not produce significant expression change compared to the control for the planktonic cells, although there was a significant increase for the atpD gene. Therefore, C8-OG might be a potent antibiofilm and/or anticaries agent for oral formulations that aim to reduce the prevalence of dental caries.

Effects of Fluoride, Lithium and Strontium on Extracellular Polysaccharide Production by Streptococcus mutans and Actinomyces viscosus

1981 ◽  
Vol 60 (C) ◽  
pp. 1601-1610 ◽  
Author(s):  
Patrick Treasure
Keyword(s):  
Trace Elements ◽  
Streptococcus Mutans ◽  
Extracellular Polysaccharide ◽  
Water Soluble ◽  
Extracellular Polysaccharides ◽  
Polysaccharide Production

Effects of trace elements on production of extracellular polysaccharides (EPS) by S. mutans and A. viscosus were examined in vitro. Fluoride enhanced EPS production. Lithium and strontium had little effect alone, but tended to reverse the effect of fluoride. The proportion of water-soluble EPS and the proportion of glucosyl-EPS were increased by fluoride.

scholarly journals Symbiotic Relationship between Streptococcus mutans and Candida albicans Synergizes Virulence of Plaque BiofilmsIn Vivo

2014 ◽  
Vol 82 (5) ◽  
pp. 1968-1981 ◽  
Author(s):  
Megan L. Falsetta ◽  
Marlise I. Klein ◽  
Punsiri M. Colonne ◽  
Kathleen Scott-Anne ◽  
Stacy Gregoire ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Dental Caries ◽  
Streptococcus Mutans ◽  
Bacterial Pathogen ◽  
Single Species ◽  
Content Type ◽  
3 Dimensional ◽  
Biofilm Development

ABSTRACTStreptococcus mutansis often cited as the main bacterial pathogen in dental caries, particularly in early-childhood caries (ECC).S. mutansmay not act alone;Candida albicanscells are frequently detected along with heavy infection byS. mutansin plaque biofilms from ECC-affected children. It remains to be elucidated whether this association is involved in the enhancement of biofilm virulence. We showed that the ability of these organisms together to form biofilms is enhancedin vitroandin vivo. The presence ofC. albicansaugments the production of exopolysaccharides (EPS), such that cospecies biofilms accrue more biomass and harbor more viableS. mutanscells than single-species biofilms. The resulting 3-dimensional biofilm architecture displays sizeableS. mutansmicrocolonies surrounded by fungal cells, which are enmeshed in a dense EPS-rich matrix. Using a rodent model, we explored the implications of this cross-kingdom interaction for the pathogenesis of dental caries. Coinfected animals displayed higher levels of infection and microbial carriage within plaque biofilms than animals infected with either species alone. Furthermore, coinfection synergistically enhanced biofilm virulence, leading to aggressive onset of the disease with rampant carious lesions. Ourin vitrodata also revealed that glucosyltransferase-derived EPS is a key mediator of cospecies biofilm development and that coexistence withC. albicansinduces the expression of virulence genes inS. mutans(e.g.,gtfB,fabM). We also found thatCandida-derived β1,3-glucans contribute to the EPS matrix structure, while fungal mannan and β-glucan provide sites for GtfB binding and activity. Altogether, we demonstrate a novel mutualistic bacterium-fungus relationship that occurs at a clinically relevant site to amplify the severity of a ubiquitous infectious disease.

scholarly journals Effects of resveratrol on cariogenic virulence properties of Streptococcus mutans

2020 ◽  
Author(s):  
Jinheng Li ◽  
Tiantian Wu ◽  
Weiwei Peng ◽  
yaqin zhu
Keyword(s):  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Acid Production ◽  
Virulence Gene ◽  
Acid Tolerance ◽  
Extracellular Polysaccharide ◽  
Inhibitory Effect ◽  
Water Soluble ◽  
Virulence Gene Expression ◽  
Virulence Properties

Abstract Background: Streptococcus mutans is the principal etiological agent of human dental caries. The major virulence factors of S. mutans are acid production, acid tolerance, extracellular polysaccharide (EPS) synthesis and biofilm formation. The aim of this study is to evaluate the effect of resveratrol, a natural compound, on virulence properties of S. mutans . Results: Resveratrol at sub-MIC levels significantly decreased acid production and acid tolerance, inhibited synthesis of water-soluble polysaccharide and water-insoluble polysaccharide, compromised biofilm formation. Related virulence gene expression ( ldh, relA, gtfC, comDE ) was down-regulated with increasing concentrations of resveratrol. Conclusions : Resveratrol has an inhibitory effect on S. mutans cariogenic virulence properties and it represents a promising anticariogenic agent. Keywords : resveratrol, Streptococcus mutans , acidogenicity, aciduricity, extracellular polysaccharide, biofilm

scholarly journals l-Arginine Modifies the Exopolysaccharide Matrix and Thwarts Streptococcus mutans Outgrowth within Mixed-Species Oral Biofilms

2016 ◽  
Vol 198 (19) ◽  
pp. 2651-2661 ◽  
Author(s):  
Jinzhi He ◽  
Geelsu Hwang ◽  
Yuan Liu ◽  
Lizeng Gao ◽  
LaTonya Kilpatrick-Liverman ◽  
...  
Keyword(s):  
Dental Caries ◽  
Streptococcus Mutans ◽  
Biological Properties ◽  
Vehicle Control ◽  
Microbial Interactions ◽  
Mixed Species ◽  
Matrix Assembly ◽  
Content Type ◽  
Biofilm Development ◽  
Biofilm Matrix

ABSTRACTl-Arginine, a ubiquitous amino acid in human saliva, serves as a substrate for alkali production by arginolytic bacteria. Recently, exogenousl-arginine has been shown to enhance the alkalinogenic potential of oral biofilm and destabilize its microbial community, which might help control dental caries. However,l-arginine exposure may inflict additional changes in the biofilm milieu when bacteria are growing under cariogenic conditions. Here, we investigated how exogenousl-arginine modulates biofilm development using a mixed-species model containing both cariogenic (Streptococcus mutans) and arginolytic (Streptococcus gordonii) bacteria in the presence of sucrose. We observed that 1.5% (wt/vol)l-arginine (also a clinically effective concentration) exposure suppressed the outgrowth ofS. mutans, favoredS. gordoniidominance, and maintainedActinomyces naeslundiigrowth within biofilms (versus vehicle control). In parallel, topicall-arginine treatments substantially reduced the amounts of insoluble exopolysaccharides (EPS) by >3-fold, which significantly altered the three-dimensional (3D) architecture of the biofilm. Intriguingly,l-arginine repressedS. mutansgenes associated with insoluble EPS (gtfB) and bacteriocin (SMU.150) production, whilespxBexpression (H2O2production) byS. gordoniiincreased sharply during biofilm development, which resulted in higher H2O2levels in arginine-treated biofilms. These modifications resulted in a markedly defective EPS matrix and areas devoid of any bacterial clusters (microcolonies) on the apatitic surface, while thein situpH values at the biofilm-apatite interface were nearly one unit higher in arginine-treated biofilms (versus the vehicle control). Our data reveal new biological properties ofl-arginine that impact biofilm matrix assembly and the dynamic microbial interactions associated with pathogenic biofilm development, indicating the multiaction potency of this promising biofilm disruptor.IMPORTANCEDental caries is one of the most prevalent and costly infectious diseases worldwide, caused by a biofilm formed on tooth surfaces. Novel strategies that compromise the ability of virulent species to assemble and maintain pathogenic biofilms could be an effective alternative to conventional antimicrobials that indiscriminately kill other oral species, including commensal bacteria.l-Arginine at 1.5% has been shown to be clinically effective in modulating cariogenic biofilms via alkali production by arginolytic bacteria. Using a mixed-species ecological model, we show new mechanisms by whichl-arginine disrupts the process of biofilm matrix assembly and the dynamic microbial interactions that are associated with cariogenic biofilm development, without impacting the bacterial viability. These results may aid in the development of enhanced methods to control biofilms usingl-arginine.

scholarly journals Glycosyltransferase-Mediated Biofilm Matrix Dynamics and Virulence ofStreptococcus mutans

2018 ◽  
Vol 85 (5) ◽  
Author(s):  
Katherine Rainey ◽  
Suzanne M. Michalek ◽  
Zezhang T. Wen ◽  
Hui Wu
Keyword(s):  
Dental Caries ◽  
Streptococcus Mutans ◽  
Virulence Factor ◽  
Membrane Vesicles ◽  
Tooth Decay ◽  
Content Type ◽  
Matrix Components ◽  
Biofilm Development ◽  
Biofilm Matrix ◽  
Matrix Dynamics

ABSTRACTStreptococcus mutansis a key cariogenic bacterium responsible for the initiation of tooth decay. Biofilm formation is a crucial virulence property. We discovered a putative glycosyltransferase, SMU_833, inS. mutanscapable of modulating dynamic interactions between two key biofilm matrix components, glucan and extracellular DNA (eDNA). The deletion ofsmu_833decreases glucan and increases eDNA but maintains the overall biofilm biomass. The decrease in glucan is caused by a reduction in GtfB and GtfC, two key enzymes responsible for the synthesis of glucan. The increase in eDNA was accompanied by an elevated production of membrane vesicles, suggesting that SMU_833 modulates the release of eDNA via the membrane vesicles, thereby altering biofilm matrix constituents. Furthermore, glucan and eDNA were colocalized. The complete deletion ofgtfBCfrom thesmu_833mutant significantly reduced the biofilm biomass despite the elevated eDNA, suggesting the requirement of minimal glucans as a binding substrate for eDNA within the biofilm. Despite no changes in overall biofilm biomass, the mutant biofilm was altered in biofilm architecture and was less acidicin vitro. Concurrently, the mutant was less virulent in anin vivorat model of dental caries, demonstrating that SMU_833 is a new virulence factor. Taken together, we conclude that SMU_833 is required for optimal biofilm development and virulence ofS. mutansby modulating extracellular matrix components. Our study of SMU_833-modulated biofilm matrix dynamics uncovered a new target that can be used to develop potential therapeutics that prevent and treat dental caries.IMPORTANCETooth decay, a costly and painful disease affecting the vast majority of people worldwide, is caused by the bacteriumStreptococcus mutans. The bacteria utilize dietary sugars to build and strengthen biofilms, trapping acids onto the tooth’s surface and causing demineralization and decay of teeth. As knowledge of our body’s microbiomes increases, the need for developing therapeutics targeted to disease-causing bacteria has arisen. The significance of our research is in studying and identifying a novel therapeutic target, a dynamic biofilm matrix that is mediated by a new virulence factor and membrane vesicles. The study increases our understanding ofS. mutansvirulence and also offers a new opportunity to develop effective therapeutics targetingS. mutans. In addition, the mechanisms of membrane vesicle-mediated biofilm matrix dynamics are also applicable to other biofilm-driven infectious diseases.

scholarly journals Coordinated Regulation of the EIIMan and fruRKI Operons of Streptococcus mutans by Global and Fructose-Specific Pathways

2017 ◽  
Vol 83 (21) ◽  
Author(s):  
Lin Zeng ◽  
Brinta Chakraborty ◽  
Tanaz Farivar ◽  
Robert A. Burne
Keyword(s):  
Energy Metabolism ◽  
Dental Caries ◽  
Streptococcus Mutans ◽  
Regulation Of Gene Expression ◽  
Phosphotransferase System ◽  
Carbohydrate Source ◽  
Content Type ◽  
Fructose Metabolism ◽  
Biofilm Development

ABSTRACTThe glucose/mannose-phosphotransferase system (PTS) permease EIIManencoded bymanLMNin the dental caries pathogenStreptococcus mutanshas a dominant influence on sugar-specific, CcpA-independent catabolite repression (CR). Mutations inmanLaffect energy metabolism and virulence-associated traits, including biofilm formation, acid tolerance, and competence. Using promoter::reporter fusions, expression of themanLMNand thefruRKIoperons, encoding a transcriptional regulator, a fructose-1-phosphate kinase and a fructose-PTS permease EIIFru, respectively, was monitored in response to carbohydrate source and in mutants lacking CcpA, FruR, and components of EIIMan. Expression of genes for EIIManand EIIFruwas directly regulated by CcpA and CR, as evinced byin vivoandin vitromethods. Unexpectedly, not only was thefruRKIoperon negatively regulated by FruR, but also so wasmanLMN. Carbohydrate transport by EIIManhad a negative influence on expression ofmanLMNbut notfruRKI. In agreement with the proposed role of FruR in regulating these PTS operons, loss offruRorfruKsubstantially altered growth on a number of carbohydrates, including fructose. RNA deep sequencing revealed profound changes in gene regulation caused by deletion offruKorfruR. Collectively, these findings demonstrate intimate interconnection of the regulation of two major PTS permeases inS. mutansand reveal novel and important contributions of fructose metabolism to global regulation of gene expression.IMPORTANCEThe ability ofStreptococcus mutansand other streptococcal pathogens to survive and cause human diseases is directly dependent upon their capacity to metabolize a variety of carbohydrates, including glucose and fructose. Our research reveals that metabolism of fructose has broad influences on the regulation of utilization of glucose and other sugars, and mutants with changes in certain genes involved in fructose metabolism display profoundly different abilities to grow and express virulence-related traits. Mutants lacking the FruR regulator or a particular phosphofructokinase, FruK, display changes in expression of a large number of genes encoding transcriptional regulators, enzymes required for energy metabolism, biofilm development, biosynthetic and degradative processes, and tolerance of a spectrum of environmental stressors. Since fructose is a major component of the modern human diet, the results have substantial significance in the context of oral health and the development of dental caries.

scholarly journals Effects of brief sodium fluoride treatments on the growth of early and mature cariogenic biofilms

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ye Han
Keyword(s):  
Dental Caries ◽  
Sodium Fluoride ◽  
Biofilm Formation ◽  
Water Soluble ◽  
Laser Scanning Microscopy ◽  
Extracellular Polysaccharides ◽  
Antibiofilm Activity ◽  
Fluoride Treatment ◽  
Biofilm Development ◽  
Cariogenic Biofilm

AbstractAlthough fluoride has been widely used as a preventive agent for dental caries, the effects of fluoride on the activities of biofilms in different stages of cariogenic biofilm formation are less studied. This study was designed to investigate the antibiofilm activity of sodium fluoride during the early and mature stages of Streptococcus mutans (S. mutans) biofilm formation. S. mutans biofilms were formed on saliva-coated hydroxyapatite disks. In the early (0–46 h) and mature (46–94 h) biofilm stages, the biofilms were treated with different concentrations of fluoride (250, 500, 1000, 2000 ppm; 5 times in total, 1 min/treatment). Acidogenicity, dry weight, colony-forming units (CFUs), water-soluble/insoluble extracellular polysaccharides (EPSs), and intracellular polysaccharides were analysed, and confocal laser scanning microscopy images were obtained of the two stages of biofilms to determine antibiofilm activities of fluoride at varying concentrations during the formation of early and mature biofilms. In the early stages of cariogenic biofilm formation, test groups with all fluoride concentrations significantly inhibited the growth of S. mutans biofilms. The antibiofilm and anti-EPS formation activities of the brief fluoride treatments increased with a concentration-dependent pattern. At the mature biofilm stage, only the 2000 ppm fluoride treatment group significantly inhibited biofilm accumulation, activity, and intracellular/extracellular polysaccharide content compared with those of the control and other fluoride treatment groups. The antimicrobial effect of fluoride treatment on the growth of S. mutans biofilms was linked with the stage of cariogenic biofilm formation. The inhibition of S. mutans biofilm growth by fluoride treatment was easier in the early formation stage than in the mature stage. Fluoride treatment in the early stage of cariogenic biofilm formation may be an effective approach to controlling cariogenic biofilm development and preventing dental caries.

scholarly journals Effects of resveratrol on cariogenic virulence properties of Streptococcus mutans

2020 ◽  
Author(s):  
Jinheng Li ◽  
Yaqin Zhu ◽  
Tiantian Wu ◽  
Weiwei Peng
Keyword(s):  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Acid Production ◽  
Virulence Gene ◽  
Acid Tolerance ◽  
Extracellular Polysaccharide ◽  
Inhibitory Effect ◽  
Water Soluble ◽  
Virulence Gene Expression ◽  
Virulence Properties

Abstract Background: Streptococcus mutans is the principal etiological agent of human dental caries. The major virulence factors of S. mutans are acid production, acid tolerance, extracellular polysaccharide (EPS) synthesis and biofilm formation. The aim of this study is to evaluate the effect of resveratrol, a natural compound, on virulence properties of S. mutans . Methods: The effect of resveratrol on acidogenicity was investigated by pH drop and lactate dehydrogenase (LDH) assay, on aciduricity through survival rate at pH 5.0 and F-ATPase assay, on EPS synthesis (including water-soluble polysaccharide and water-insoluble polysaccharide) by quantitative measurement, on biofilm formation by crystal violet assay and structure observation. The expression of related virulence genes was also detected . Results: Resveratrol at sub-MIC levels can significantly decrease acid production, acid tolerance, EPS synthesis and biofilm formation. Related virulence gene expression ( ldh , relA , gtfC , comDE ) was down-regulated with increasing concentrations of resveratrol. Conclusion: Resveratrol has an inhibitory effect on S. mutans cariogenic virulence properties and it represents a promising anticariogenic agent .

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