scholarly journals Enamel Carious Lesion Development in Response to Sucrose and Fluoride Concentrations and to Time of Biofilm Formation: An Artificial-Mouth Study

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Rodrigo Alex Arthur ◽  
Eduardo Kazuo Kohara ◽  
Robert Aaron Waeiss ◽  
George J. Eckert ◽  
Domenick Zero ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Artificial Saliva ◽  
Fluoride Concentration ◽  
Carious Lesion ◽  
Lesion Development ◽  
Viable Cells ◽  
Artificial Mouth ◽  
Carious Lesions ◽  
Caries Model

The aim of this study was to evaluate both sucrose and fluoride concentrations and time of biofilm formation on enamel carious lesions induced by an in vitro artificial-mouth caries model. For Study 1, biofilms formed by streptococci and lactobacilli were grown on the surface of human enamel slabs and exposed to artificial saliva containing 0.50 or 0.75 ppmF (22.5 h/d) and broth containing 3 or 5% sucrose (30 min; 3x/d) over 5 d. In Study 2, biofilms were grown in the presence of 0.75 ppmF and 3% sucrose over 3 and 9 days. Counts of viable cells on biofilms, lesion depth (LD), and the integrated mineral loss (IML) on enamel specimens were assessed at the end of the tested conditions. Counts of total viable cells and L. casei were affected by sucrose and fluoride concentrations as well as by time of biofilm formation. Enamel carious lesions were shallower and IML was lower in the presence of 0.75 ppmF than in the presence of 0.50 ppmF (P<0.005). No significant effect of sucrose concentrations was found with respect to LD and IML (P>0.25). Additionally, deeper lesions and higher IML were found after 9 d of biofilm formation (P<0.005). Distinct sucrose concentrations did not affect enamel carious lesion development. The severity of enamel demineralization was reduced by the presence of the higher fluoride concentration. Additionally, an increase in the time of biofilm formation produced greater demineralization. Our results also suggest that the present model is suitable for studying aspects related to caries lesion development.

scholarly journals Dietary Nitrite Drives Disease Outcomes in Oral Polymicrobial Infections

2019 ◽  
Vol 98 (9) ◽  
pp. 1020-1026 ◽  
Author(s):  
J. Scoffield ◽  
S. Michalek ◽  
G. Harber ◽  
P. Eipers ◽  
C. Morrow ◽  
...  
Keyword(s):  
Dental Caries ◽  
Biofilm Formation ◽  
Reactive Nitrogen Species ◽  
Nitrosative Stress ◽  
Disease Outcomes ◽  
Carious Lesions ◽  
Caries Model ◽  
Polymicrobial Infections

Streptococcus mutans resides in the oral polymicrobial biofilm and is a major contributor to the development of dental caries. Interestingly, high salivary nitrite concentrations have been associated with a decreased prevalence of dental caries. Moreover, the combination of hydrogen peroxide–producing oral commensal streptococci and nitrite has been shown to mediate the generation of reactive nitrogen species, which have antimicrobial activity. The goal of this study was to examine whether nitrite affects S. mutans virulence during polymicrobial infections with the commensal Streptococcus parasanguinis. Here, we report that the combination of S. parasanguinis and nitrite inhibited S. mutans growth and biofilm formation in vitro. Glucan production, which is critical for S. mutans biofilm formation, was also inhibited in 2-species biofilms with S. parasanguinis containing nitrite as compared with biofilms that contained no nitrite. In the in vivo caries model, enamel and dentin carious lesions were significantly reduced in rats that were colonized with S. parasanguinis prior to infection with S. mutans and received nitrite in the drinking water, as compared with animals that had a single S. mutans infection or were co-colonized with both bacteria and received no nitrite. Last, we report that S. mutans LiaS, a sensor kinase of the LiaFSR 3-component system, mediates resistance to nitrosative stress. In summary, our data demonstrate that commensal streptococci and nitrite provide protection against S. mutans pathogenesis. Modulating nitrite concentrations in the oral cavity could be a useful strategy to combat the prevalence of dental caries.

scholarly journals Influence of artificial saliva in biofilm formation of Candida albicans in vitro

2012 ◽  
Vol 26 (1) ◽  
pp. 24-28 ◽  
Author(s):  
Michelle Peneluppi Silva ◽  
José Chibebe Junior ◽  
Adeline Lacerda Jorjão ◽  
Ana Karina da Silva Machado ◽  
Luciane Dias de Oliveira ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Biofilm Formation ◽  
Artificial Saliva

scholarly journals Synthetic antigen-binding fragments (Fabs) against S. mutans and S. sobrinus inhibit caries formation

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Md. Kausar Alam ◽  
Li Zheng ◽  
Ruirui Liu ◽  
Silvana Papagerakis ◽  
Petros Papagerakis ◽  
...  
Keyword(s):  
Dental Caries ◽  
Biofilm Formation ◽  
Passive Immunization ◽  
Tooth Surface ◽  
Antigen Binding ◽  
Streptococcus Sobrinus ◽  
Immunization Strategies ◽  
Caries Model ◽  
Causative Agents

Abstract Streptococcus mutans and Streptococcus sobrinus are the main causative agents of human dental caries. Current strategies for treating caries are costly and do not completely eradicate them completely. Passive immunization using nonhuman antibodies against Streptococcal surface antigens has shown success in human trials, however they often invoke immune reactions. We used phage display to generate human antigen-binding fragments (Fabs) against S. mutans and S. sobrinus. These Fabs were readily expressed in E. coli and bound to the surface S. mutans and S. sobrinus. Fabs inhibited sucrose-induced S. mutans and S. sobrinus biofilm formation in vitro and a combination of S. mutans and S. sobrinus Fabs prevented dental caries formation in a rat caries model. These results demonstrated that S. mutans and S. sobrinus Fabs could be used in passive immunization strategies to prevent dental caries. In the future, this strategy may be applied towards a caries therapy, whereby Fabs are topically applied to the tooth surface.

scholarly journals An In-Vitro Evaluation of Microbial Adhesion on Different Types of Orthodontic Brackets

2021 ◽  
Author(s):  
Vedant Patni ◽  
Kuldeep Dmello ◽  
Jitesh Wadhwa ◽  
Mora Sathi Rami Reddy ◽  
Atul Singh
Keyword(s):  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Artificial Saliva ◽  
Bacterial Species ◽  
Brain Heart Infusion ◽  
In Vitro Study ◽  
The Self ◽  
Orthodontic Brackets ◽  
Ceramic Brackets

Introduction: Information regarding the adhesion of bacterial species and plaque accumulation to bracket material is limited. Adequate information is needed in order to offer patients orthodontic treatment without significantly increasing their risk of developing white spots, caries, or gingival inflammation. Aim: To determine the levels of the caries-inducing S. mutans species on metallic, self-ligating and ceramic brackets and to compare the total bacterial counts and counts of species present on these bracket materials. Materials and Methods: By means of an in-vitro study, six commercially available bracket systems {3M Gemini (A), American Ortho (B), Ormco (C), Begg (D), Ceramic (E) and Self-ligating (F)} were compared. The brackets were bonded in the cell well culture plate and the agar plates were prepared. Brain heart infusion medium including bacteria and artificial saliva was introduced to each bracket system containing 10 premolar brackets and were incubated. After 72 hours, the adherent bacteria were then detached by sonication and the Colony-Forming Units (CFU) of Streptococcus mutans were calculated on each bracket and were analysed using Statistical Package for the Social Sciences (SPSS) software version 17.0 for Windows. Results: Between the different bracket types, significant differences were found in terms of biofilm formation. The Begg brackets showed the least bacterial adhesion and the self-ligating brackets showed the highest bacterial adhesion and was statistically significant among all the groups (p<0.05). Ceramic brackets also showed a higher bacterial adhesion after the self-ligating brackets. Among the three groups of metallic brackets, 3M brackets showed the least bacterial adhesion but was statistically insignificant (p>0.05). Conclusion: Different orthodontic brackets serve as different loci for biofilm formation showing that the Begg brackets are the most hygienic among all the brackets taken in this study.

scholarly journals The Antibacterial and Anti-biofilm Activities of Two Thiazolidione Derivatives (H2-60 and H2-81) Against Clinical Enterococcus Faecium Strains

2021 ◽  
Author(s):  
Zhong Chen ◽  
Yanpeng Xiong ◽  
Yuanyuan Tang ◽  
Yuxi Zhao ◽  
Junwen Chen ◽  
...  
Keyword(s):  
Recombinant Proteins ◽  
Histidine Kinase ◽  
Enterococcus Faecium ◽  
Biofilm Formation ◽  
Confocal Laser ◽  
Competent Cell ◽  
E Coli ◽  
Viable Cells ◽  
Mic Value

Abstract Background: Previous reports have demonstrated two thiazolidione derivatives (H2-60 and H2-81) can robustly inhibit the planktonic growth and biofilm formation of S. epidermidis and S. aureus by targeting the histidine kinase (HK) YycG. Whereas the antibacterial and anti-biofilm activity of these two thiazolidione derivatives (H2-60 and H2-81) against Enterococcus faecium remains elusive. Here, the YycG recombinant proteins containing HisKA and HATPase_c domain of E. faecium DO were in vitro expressed in E. coli competent cell BL21 (DE3) and then purified for the autophosphorylation test, indicating these two thiazolidione derivatives (H2-60 and H2-81) could directly impact the kinase phosphoration activity of YycG of E. faecium.Results: The MICs of H2-60 and H2-81 in the clinical isolates of E. faecium was in the range from 3.125mg/L to 25mg/L. Moreover, either H2-60 or H2-81showed the excellent bactericidal activity against E. faecium with the single dose or its combination with daptomycin (4 × MIC) by time-killing assay. Furthermore, over 90% of E. faecium biofilm formation could markedly be inhibited by two thiazolidione derivatives (H2-60 and H2-81) within 1/4×MIC value. In addition, the frequency of the eradicated viable cells embedded in mature biofilm were evaluated by the confocal laser microscopy, suggesting that of H2-60 combined with ampicillin or daptomycin was significantly high when compared with its monotherapy (78.17% and 74.48%vs.41.59%, respectively, P< 0.01). Conclusion: Two thiazolidione derivatives (H2-60 and H2-81) exhibit the robust antibacterial and anti-biofilm activity against E. faecium by targeting the histidine kinase (HK) YycG.

scholarly journals Phage Targeting Streptococcus mutans In Vitro and In Vivo as a Caries-Preventive Modality

Antibiotics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1015
Author(s):  
Amit Wolfoviz-Zilberman ◽  
Reut Kraitman ◽  
Ronen Hazan ◽  
Michael Friedman ◽  
Yael Houri-Haddad ◽  
...  
Keyword(s):  
Sustained Release ◽  
Streptococcus Mutans ◽  
Delivery System ◽  
Phage Therapy ◽  
Caries Prevention ◽  
Promising Alternative ◽  
Carious Lesions ◽  
Caries Model

Dental caries is a common infectious disease worldwide. Current conventional therapies lack specific antimicrobial effects against Streptococcus mutans, a key bacterium that induces caries. A promising alternative approach is bacteriophage (phage) therapy. Recently, SMHBZ8 phage targeting S. mutans was isolated and characterized. The aim of this study was to evaluate the caries-prevention efficacy of SMHBZ8 using in vitro and in vivo caries models. Hemi-mandibles dissected from euthanized healthy mice were subjected to caries-promoting conditions in vitro. Jaws treated with phage therapy in suspension and in formulation with a sustained-release delivery system showed no carious lesions, similar to control and chlorhexidine-treated jaws. Subsequently, SMHBZ8 phage suspension also prevented carious lesion development in a murine caries model in vivo. In both models, caries lesions were analyzed clinically and radiographically by µCT scans. This study shows how SMHBZ8 phage therapy targeting S. mutans can serve as an efficient caries-prevention modality, in suspension or with a sustained-release delivery system, by in vitro and in vivo mouse models.

scholarly journals In vitro activities of thiazolidione derivatives combined with daptomycin against clinical Enterococcus faecium strains

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Zhong Chen ◽  
Yanpeng Xiong ◽  
Yuanyuan Tang ◽  
Yuxi Zhao ◽  
Junwen Chen ◽  
...  
Keyword(s):  
Enterococcus Faecium ◽  
Biofilm Formation ◽  
Microtiter Plate ◽  
Confocal Laser ◽  
Competent Cell ◽  
E Coli ◽  
Killing Assay ◽  
Viable Cells ◽  
Polystyrene Microtiter Plate

Abstract Background Previous reports have demonstrated two thiazolidione derivatives (H2-60 and H2-81) can robustly inhibit the planktonic growth and biofilm formation of S. epidermidis and S. aureus by targeting the histidine kinase YycG. Whereas the antibacterial and anti-biofilm activity of these two thiazolidione derivatives (H2-60 and H2-81) against Enterococcus faecium remains elusive. Here, the pET28a-YycG recombinant plasmid were in vitro expressed in E. coli competent cell BL21 (DE3) and induced to express YycG’ protein (conding HisKA and HATPase_c domain) by 0.5 mM IPTG and was purified by Ni – NTA agarose and then for the autophosphorylation test. Antimicrobial testing and time-killing assay were also be determined. Anti-biofilm activity of two derivatives with sub-MIC concentration towards positive biofilm producers of clinical E. faecium were detected using polystyrene microtiter plate and CLSM. Results The MICs of H2-60 and H2-81 in the clinical isolates of E. faecium were in the range from 3.125 mg/L to 25 mg/L. Moreover, either H2-60 or H2-81 showed the excellent bactericidal activity against E. faecium with monotherapy or its combination with daptomycin by time-killing assay. E. faecium planktonic cells can be decreased by H2-60 or H2-81 for more than 3 × log10 CFU/mL after 24 h treatment when combined with daptomycin. Furthermore, over 90% of E. faecium biofilm formation could markedly be inhibited by H2-60 and H2-81 at 1/4 × MIC value. In addition, the frequency of the eradicated viable cells embedded in mature biofilm were evaluated by the confocal laser microscopy, suggesting that of H2-60 combined with ampicillin or daptomycin was significantly high when compared with single treatment (78.17 and 74.48% vs. 41.59%, respectively, P < 0.01). Conclusion These two thiazolidione derivatives (H2-60 and H2-81) could directly impact the kinase phosphoration activity of YycG of E. faecium. H2-60 combined with daptomycin exhibit the excellent antibacterial and anti-biofilm activity against E. faecium by targeting YycG.

Caries lesion development and biofilm composition responses to varying demineralization times and sucrose exposures

Biofilms ◽  
2004 ◽  
Vol 1 (4) ◽  
pp. 229-237 ◽  
Author(s):  
M. Fontana ◽  
A. Haider ◽  
C. González-Cabezas
Keyword(s):  
Lactobacillus Casei ◽  
Bacterial Colonization ◽  
Bacterial Species ◽  
Lesion Size ◽  
Lesion Development ◽  
Carious Lesions ◽  
Caries Model ◽  
Significant Difference ◽  
Frequent Feeding ◽  
Overnight Culture

The aim of this research was to study the effect of varying incubation times and sucrose exposures on lesion development and biofilm composition using a multi-species biofilm caries model. Two studies were conducted. In study 1, enamel specimens were divided into four groups, inoculated with a mixed overnight culture of Streptococcus mutans, Lactobacillus casei, Actinomycesnaeslundii, Streptococcusparasanguis and Streptococcussalivarius, and exposed to circulating trypticase soy broth + 5% (w/v) sucrose (TSBS; 30 min, three times per day (3 × /day)) and a mineral washing solution containing 0.25 p.p.m. fluoride (22.5 h/day) for 2, 5, 6 or 8 days. In study 2, additional enamel specimens were divided into four groups and exposed to the same biofilm for 7 days, but with variations in the feeding schedule: TSBS 3×/day for 5 min, TSBS 3×/day for 15 min, TSBS 3 × /day for 30 min, or TSBS 3×/day for 30 min + 1×/day for 15 min. At the end of each study, bacterial colonization counts and lesion size were determined. In study 1, specimens developed significantly deeper carious lesions with longer demineralization time (average lesion depth was 52.16 μm, 67.86 μm, 84.91 μm, and 99.97 μm, respectively, for 2, 5, 6, and 8 days). In study 2, there was no significant difference in size between the lesions developed at feeding schedules of 3 × /day for 5 or 15 min. Lesions exposed to longer (30 min) and more frequent feeding schedules (4×/day) were significantly larger than the other groups. In both studies, all five bacterial species were able to colonize the enamel and were present in all groups at the end of the experiments, with predominance of lactobacilli over S. mutans. In conclusion, larger lesions were observed with increased incubation time and more frequent feeding schedules, with small variations in biofilm composition.

scholarly journals Effect of treatment time on performance of nano-encapsulatedfluoride de ntifrices for remineralization of initial carious lesions: an in vitro study

2021 ◽  
Vol 34 (1) ◽  
pp. 56-62
Author(s):  
Andressa Oliveira ◽  
Elizabeth Sousa ◽  
Nayanna Fernandes ◽  
Ingrid Meira ◽  
Juliane Lavôr ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Treatment Time ◽  
In Vitro Study ◽  
Positive Control ◽  
Negative Control ◽  
Vitro Study ◽  
Carious Lesion ◽  
Time Data ◽  
Carious Lesions

The aim of this in vitro study was to evaluate the influence of treatment time on the remineralization performance of nanoencapsulated fluoride dentifrices on initial carious lesions. Ninety-six human enamel samples were allocated to eight groups (n = 12): 50% NanoF + 50% free NaF, 100% NanoF, 100% NaF (positive control), and placebo (negative control), using two different treatment times (one and five minutes) for each dentifrice tested. After the carious lesion induction, the specimens were submitted to a pH remineralizing cycling model for seven days. Surface microhardness was measured before and after carious lesion induction and after treatment. The percentage of surface remineralization was calculated for each study time. Data were analyzed using two-way ANOVA and ANOVA repeated-measures tests followed by the Bonferroni correction (p < 0.05). Remineralization differences were observed in the dentifrices analyzed according to the treatment time used. NanoF formulations with 50% (one-min treatment) and 100% (five-min treatment) promoted significant remineralization of enamel after the caries challenge when compared to the placebo dentifrice (p < 0.05). Thus, time was considered an important factor for the fluoride release system. Nanotechnology can be a promising system for caries remineralization as it makes fluoride available on the dental surface for a longer time.

scholarly journals Acetylation of glucosyltransferases regulates Streptococcus mutans biofilm formation and virulence

2021 ◽  
Vol 17 (12) ◽  
pp. e1010134
Author(s):  
Qizhao Ma ◽  
Yangyang Pan ◽  
Yang Chen ◽  
Shuxing Yu ◽  
Jun Huang ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Extracellular Polysaccharides ◽  
Lysine Acetylation ◽  
Post Translational Modification ◽  
Caries Model ◽  
Acetyl Group ◽  
Important Virulence Factor ◽  
Protein Acetyltransferase

Lysine acetylation is a frequently occurring post-translational modification (PTM), emerging as an important metabolic regulatory mechanism in prokaryotes. This process is achieved enzymatically by the protein acetyltransferase (KAT) to specifically transfer the acetyl group, or non-enzymatically by direct intermediates (acetyl phosphate or acetyl-CoA). Although lysine acetylation modification of glucosyltransferases (Gtfs), the important virulence factor in Streptococcus mutans, was reported in our previous study, the KAT has not been identified. Here, we believe that the KAT ActG can acetylate Gtfs in the enzymatic mechanism. By overexpressing 15 KATs in S. mutans, the synthesized water-insoluble extracellular polysaccharides (EPS) and biofilm biomass were measured, and KAT (actG) was identified. The in-frame deletion mutant of actG was constructed to validate the function of actG. The results showed that actG could negatively regulate the water-insoluble EPS synthesis and biofilm formation. We used mass spectrometry (MS) to identify GtfB and GtfC as the possible substrates of ActG. This was also demonstrated by in vitro acetylation assays, indicating that ActG could increase the acetylation levels of GtfB and GtfC enzymatically and decrease their activities. We further found that the expression level of actG in part explained the virulence differences in clinically isolated strains. Moreover, overexpression of actG in S. mutans attenuated its cariogenicity in the rat caries model. Taken together, our study demonstrated that the KAT ActG could induce the acetylation of GtfB and GtfC enzymatically in S. mutans, providing insights into the function of lysine acetylation in bacterial virulence and pathogenicity.

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