The effect of extracellular polysaccharides from Streptococcus mutans on the bactericidal activity of human neutrophils (original) (raw)
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In vitro colonization of Streptococcus mutans
Infection and Immunity
An in vitro model consisting of enamel from extracted human molars, suspended from wires in inoculated culture tubes, was used to study the adhesion of bacteria to enamel. Under conditions in which there was no macroscopically visible plaque formation, electron micrographs showed no bacterial deposits on the enamel surface. In samples where Streptococcus mutans attached to enamel, an extracellular, pellicle-like material was'associated with the bacteria adjacent to the enamel. This material appeared to bind to the enamel surface and to mediate bacterial attachment. Membrane-filtered (Millipore Corp.) saliva deposited a thin surface layer on the enamel, but there were no observable alterations of S. mutans attachment to enamel pretreated with saliva. It was noted that Bratthall serotype c and e strains of S. mutans, when grown in glucose-containing medium, attached, although less tenaciously, to enamel and nichrome wires. Chemical and gas chromatographic analyses of cell-associated materials formed by serotype c and e strains cultured in glucose-containing medium revealed low amounts of glucosepositive material and no polymer linkages characteristic of glucan; yet the same strains cultured in sucrose-containing medium had relatively high amounts of glucose-positive material, with polymer linkages characteristic of glucan. Serotype a, b, and d strains could attach only in sucrose-containing media.
Frontiers in Cell and Developmental Biology, 2020
Cariogenic Streptococcus mutans (S. mutans) is implicated in the dental pulp necrosis but also in cardiovascular tissue infections. Herein, the purpose was to elucidate how human dental pulp derived stromal cells (DPSCs) react toward a direct interaction with S. mutans. DPSCs were challenged with S. mutans. Following 3 h of interaction, DPSCs were able to internalize S. mutans (rate < 1%), and F-actin fibers played a significant role in this process. S. mutans persisted in the DPSCs for 48 h without causing a cytotoxic effect. S. mutans was, however, able to get out of the DPSCs cytoplasm and to proliferate in the extracellular environment. Yet, we noticed several adaptive responses of bacteria to the extracellular environment such as a modification of the kinetic growth, the increase in biofilm formation on type I collagen and polyester fabrics, as well as a tolerance toward amoxicillin. In response to infection, DPSCs adopted a proinflammatory profile by increasing the secretion of IL-8, lL-1β, and TNF-α, strengthening the establishment of the dental pulp inflammation. Overall, these findings showed a direct impact of S. mutans on DPSCs, providing new insights into the potential role of S. mutans in infective diseases.
Microbial Biosystems, 2021
Streptococcus mutans has significant virulence factors associated with the etiology and pathophysiology of dental plaque and caries through adherence to the tooth surface and biofilm formation. These microbes can tolerate and survive the acidic environment. The study aimed to compare the behavior of the S. mutans isolates from dental plaque and caries conditions, in addition to the evaluation of the biofilm formation by S. mutans with oral microbiota (Candida albicans). A total of 106 S. mutans isolates were recovered including 56 isolates from soft caries lesions, 30 isolates from the plaque of caries active and 20 isolates from the plaque of cariesfree samples. The isolates' virulence efficacy was assessed phenotypically by acid production, acid tolerance, and biofilm formation assays. PCR detected genes encoding these virulence traits. There was a significant difference (p < 0.05) between the three groups of isolates in biofilm formation, biofilm formation when co-cultivated with C. albicans, pH reduction by acid production, but there was no significant difference in withstanding acidic pH. S. mutans isolates harbored the genes glucosyltransferase B (gtfB), glucan binding protein B (gbpB), F1F0 membrane-bound proton-translocating ATPase C subunit (atpH) and lactate dehydrogenase (ldh) which are responsible for biofilm formation, sucrosedependent adhesion, acid tolerance and acid production, respectively. In conclusion, S. mutans isolates from caries-free and caries active dental plaque and dental caries conditions showed different virulence efficacy-based behaviour. C. albicans enhances the biofilm formation by S. mutans. Further investigation of factors influencing variable behavior of S. mutans bacteria from different lesions is warranted.
Streptococcus mutans-derived extracellular matrix in cariogenic oral biofilms
Frontiers in Cellular and Infection Microbiology, 2015
Biofilms are highly structured microbial communities that are enmeshed in a self-produced extracellular matrix. Within the complex oral microbiome, Streptococcus mutans is a major producer of extracellular polymeric substances including exopolysaccharides (EPS), eDNA, and lipoteichoic acid (LTA). EPS produced by S. mutans-derived exoenzymes promote local accumulation of microbes on the teeth, while forming a spatially heterogeneous and diffusion-limiting matrix that protects embedded bacteria. The EPS-rich matrix provides mechanical stability/cohesiveness and facilitates the creation of highly acidic microenvironments, which are critical for the pathogenesis of dental caries. In parallel, S. mutans also releases eDNA and LTA, which can contribute with matrix development. eDNA enhances EPS (glucan) synthesis locally, increasing the adhesion of S. mutans to saliva-coated apatitic surfaces and the assembly of highly cohesive biofilms. eDNA and other extracellular substances, acting in concert with EPS, may impact the functional properties of the matrix and the virulence of cariogenic biofilms. Enhanced understanding about the assembly principles of the matrix may lead to efficacious approaches to control biofilm-related diseases.
Microbios, 1976
This study comprised an ultrastructural examination of a cariogenic strain of Streptococcus mutans, C67-1, and a non-cariogenic mutant of that strain, C67-25. The aim of the work was to define more clearly the relationship between S. mutans and dental caries and, more specifically, to elicit ultrastructural evidence for the conclusion from a previous investigation that the greater survival of the parent strain in sucrose broth at uncontrolled pH was related partly to the production in this medium of abundant extracellular polysaccharide (EPS). The strains were grown as previously in 5% (w/v) glucose or sucrose broths, the pH being either allowed to fall or maintained above 6.0, and processed by the thiosemicarbazide technique for election microscopy. It was confirmed that EPS was most abundant in the sucrose broth culture of the parent strain at uncontrolled pH. While the presence of abundant EPS relates to the greater survival of the parent strain in sucrose broth at uncontrolled p...
A REVIEW ON STREPTOCOCCUS MUTANS WITH ITS DISEASES DENTAL CARIES, DENTAL PLAQUE AND ENDOCARDITIS
Indian Journal of Microbiology Research, 2015
Microorganisms present in our oral cavity which are called the human micro flora attach to our tooth surfaces and develop biofilms. In maximum organic habitats microorganisms generally prevail as multispecies biolfilms with the help of intercellular interactions and communications among them which are the main keys for their endurance. These biofilms are formed by initial attachment of bacteria to a surface, development of a multi-dimensional complex structure and detachment to progress other site. The best example of biofilm formation is dental plaque. Plaque formation can lead to dental caries and other associated diseases causing tooth loss. Many different bacteria are involved in these processes and one among them is Streptococcus mutans which is the principle and the most important agent. When these infections become severe, during the treatment the bacterium can enter the bloodstream from the oral cavity and cause endocarditis. The oral bacterium S. mutans is greatly skilled in its mechanical modes of carbohydrate absorption. It also synthesizes polysaccharides that are present in dental plaque causing caries. As dental caries is a preventable disease major distinct approaches for its prevention are: carbohydrate diet, sugar substitutes, mechanical cleaning techniques, use of fluorides, antimicrobial agents, fissure sealants, vaccines, probiotics, replacement theory and dairy products and at the same time for tooth remineralization fluorides and casein phosphopeptides are extensively employed. The aim of this review article is to put forth the general features of the bacterium S.mutans and how it is involved in certain diseases like: dental plaque, dental caries and endocarditis.
Acta Odontologica Scandinavica, 2012
Objectives. To examine potential correlations between streptococcal biofilm formation and lactate production in streptococcal biofilms formed on the surface of dental materials with different surface characteristics. Materials and methods. Samples of a glass-ionomer cement (Ketac Molar) and a ceramic (Empress 2) were incubated with whole saliva and suspensions of Streptococcus mutans ATCC 25175 or Streptococcus sobrinus ATCC 33478 for initiating single-species biofilm formation for either 4 or 24 h. The relative amount of adherent, viable cells was determined using a Resazurin and a MTT assay. Metabolic activity was assessed by quantifying lactate production with a modification of the commercial Clinpro Cario L-Pop kit. Results. Both assays identified similar S. sobrinus biofilm formation on the two substrata; for S. mutans, the MTT test showed significantly fewer streptococci on the glass-ionomer cement than on the ceramic. Concerning metabolic activity, for S. sobrinus, significantly higher lactate production was observed for biofilms formed on the glass-ionomer cement in comparison to the ceramic, whereas similar values were identified for S. mutans. Conclusions. Within the limitations of the study, the results suggest that the pure amount of adherent streptococci does not a priori indicate the metabolic activity of the cariogenic bacteria organized in the respective biofilm. Thus, comparisons between the relative amount of adherent streptococci and their metabolic activity may allow for an improved understanding of the effect of dental material surfaces on the formation and metabolic activity of streptococcal biofilms.
Modulation of Streptococcus mutans virulence by dental adhesives containing anti-caries agents
Dental Materials, 2017
Objectives. The aim of this in vitro study was to analyze the effect of the incorporation of two anti-caries agents into dental adhesives on the reduction of the virulence of Streptococcus mutans and on the adhesion to dentin. Methods. Apigenin (1 mM) and tt-Farnesol (5 mM) were added separately and in combination to a self-etch adhesive (CS3-Clearfil S3 Bond Plus) and to an each-and-rinse adhesive (OPT-OptiBond S). Biofilm of S. mutans was grown on adhesive-coated hydroxyapatite disks for 115 h and bacterial viability, dry-weight, alkali soluble, water soluble, intracellular polysaccharides and protein were quantified. Bond strength and dentin-adhesive interface were performed to analyze the effects of the incorporation on the physical properties and to identify changes in hybrid layer morphology. Results. Addition of Apigenin and Apigenin + tt-Farnesol to CS3, and Apigenin or tt-Farnesol to OPT reduced the dry-weight of S. mutans biofilm. Insoluble polysaccharide decreased with the addition of Apigenin to CS3 and tt-Farnesol to OPT. Intracellular polysaccharide decreased with addition of Apigenin and Apigenin + tt-Farnesol to CS3. No changes in dentin bond strength, resin-dentin interfacial morphology, total amount of protein and soluble polysaccharide were observed with the additions. Significance. Biofilms that are less cariogenic around dental restorations could decrease secondary caries formation; in addition, the reduction of virulence of S. mutans without necessarily killing the microorganism is more unlikely to induce antimicrobial resistance.