Viability Of Streptococcus Mutans Research Articles

Effect of storage temperature on Streptococcus mutans viability

Abstract Introduction Proper storage conditions and maintenance of viable biological material plays an important role in microbiological research, allowing for the opportunity to conduct future studies. Objective To evaluate the viability of Streptococcus mutans strains that were previously grown and stored under different temperatures for approximately eight years. Material and method In this study, we evaluated 393 bacterial isolates that were stored in a freezer at -80°C (G1) and 200 isolates stored in a freezer at -20°C (G2). Aliquots of each sample were plated on blood agar and mitis-salivarius bacitracin sucrose agar-solidified medium. After incubating under microaerophilic conditions in an incubator at 37°C for 72 hours, the presence, morphology and purity of bacterial growth was observed. The data were analyzed by means of descriptive statistics. Result Microbial viability was observed in almost all samples (99.7%) in G1, whereas all isolates stored at -20°C were considered inviable. Conclusion The viability of S. mutans is influenced by the storage temperature of the samples, and the strains remain viable when stored under ideal temperature conditions (-80°C), even when stored for a long period of time.

THE EFFECT OF CURCUMA XANTHORRHIZA ETHANOL EXTRACT ON THE VIABILITY OF STREPTOCOCCUS MUTANS AND AGGREGATIBACTER ACTINOMYCETEMCOMITANS (DENTAL BIOFILM RESEARCH: IN VITRO STUDY)

Objective: This study aimed to compare the effect of Curcuma xanthrorrhiza ethanol extract to the viability of Streptococcus mutans and Aggregatibacter actinomycetemcomitans using single- and dual-species biofilm at different phases of formation.Methods: Biofilm models were incubated for 4, 12, and 24 hrs, then exposed to the extract at a concentration of 0.525%.Results: The viability of the single-species S. mutans biofilm was low (p<0.05), and no significant difference (p>0.05) was found between singlespeciesA. actinomycetemcomitans and dual-species biofilm.Conclusions: Curcuma xanthorrhiza ethanol extract is more effective for decreasing the viability of single-species S. mutans biofilm.

Efficacy of a mouthrinse based on hydroxyapatite to reduce initial bacterial colonisation in situ

ObjectiveThe present in situ - investigation aimed to specify the impact of pure hydroxyapatite microclusters on initial bioadhesion and bacterial colonization at the tooth surface. DesignPellicle formation was carried out in situ on bovine enamel slabs (9 subjects). After 1min of pellicle formation rinses with 8ml of hydroxyapatite (HA) microclusters (5%) in bidestilled water or chlorhexidine 0.2% were performed. As negative control no rinse was adopted. In situ biofilm formation was promoted by the intraoral slab exposure for 8h overnight. Afterwards initial bacterial adhesion was quantified by DAPI staining and bacterial viability was determined in vivo/in vitro by live/dead-staining (BacLight). SEM analysis evaluated the efficacy of the mouthrinse to accumulate hydroxyapatite microclusters at the specimens’ surface and spit-out samples of the testsolution were investigated by TEM. ResultsCompared to the control (2.36×106±2.01×106bacteria/cm2), significantly reduced amounts of adherent bacteria were detected on specimens rinsed with chlorhexidine 0.2% (8.73×104±1.37×105bacteria/cm2) and likewise after rinses with the hydroxyapatite testsolution (2.08×105±2.85×105bacteria/cm2, p<0.001). No demonstrable effect of HA-particles on Streptococcus mutans viability could be shown. SEM analysis confirmed the temporary adsorption of hydroxyapatite microclusters at the tooth surface. Adhesive interactions of HA-particles with oral bacteria were shown by TEM. ConclusionHydroxyapatite microclusters reduced initial bacterial adhesion to enamel in situ considerably and could therefore sensibly supplement current approaches in dental prophylaxis.

Association of chlorhexidine and high fluoride dentifrice on Streptococcus mutans viability using an in vitro biofilm model

Objective. This in vitro study investigated the effect of Fluoride (F), Chlorhexidine (CHX), and their association on the viability of Streptococcus mutans using a biofilm model. Materials and Methods. Biofilms were anaerobically grown on glass slides that were vertically suspended in 24-well plates for 5 days. After 48 h of initial growth, biofilms were treated for the next 72 h, 2x/day with CHX at 0.12% and 2%, F as NaF at 0.08% and 0.4% and their association. Results. CHX treatment decreased the bacteria counts either alone or in association with both F concentrations, when compared with control group and the F treatments alone (p&lt;0.05). Conclusion. No addition effect was observed when CHX and F were used in combination, when compared with CHX used alone.

Interaction between XTT Assay and Candida Albicans or Streptococcus Mutans Viability

Interaction between XTT Assay and Candida Albicans or Streptococcus Mutans Viability

Optimum Treatment Parameters for Photodynamic Antimicrobial Chemotherapy on &amp;lt;italic&amp;gt;Streptococcus mutans&amp;lt;/italic&amp;gt; Biofilms

The purpose of this study was to evaluate the effects of Photochemotherapy using a combination of erythrosine and standard halogen dental curing lights on the viability of Streptococcus mutans in the biofilm phase. To investigate the optimum treatment parameters, the researchers controlled the concentration of erythrosine, light irradiation time and the treatment time of erythrosine. The higher concentration of erythrosine (0, 10, 20, 40, 80 M) in the presence of light irradiation created greater effects in reducing the viability of S. mutans. The results showed a statistically significant difference among the antimicrobial effects in 20, 40, 80 M erythrosine. The higher irradiation time of light (0, 5, 15, 30, 60, 75s) in the presence of erythrosine showed greater effects in reducing the viability of S. mutans. There was statistically significant difference in 30, 60, 75 seconds. The higher treatment time of erythrosine (0, 1, 2.5, 5min) in the presence of erythrosine created greater effects on reduction of S. mutans viability. Statistically significant differences were found between 2.5 and 5 minutes of erythrosine treatment time. The results of this study showed that the photochemotherapy on S. mutans using erythrosine and the halogen dental curing lights conventionally used in dental clinics is effective in the condition of 20-40 M erythrosine concentration, irradiation time over 30 seconds, and erythrosine treatment time over 2.5 minutes.

Flow cytometric assessment of Streptococcus mutans viability after exposure to blue light-activated curcumin

Streptococcus mutans biofilms are considered as primary causative agents of dental caries. Photodynamic antimicrobial chemotherapy (PACT) has been recently proposed as a strategy for inactivating dental biofilms. This study aimed to investigate the effect of blue light-activated curcumin on S. mutans viability and to explore its potential as a new anti-caries therapeutic agent. The effect of different concentrations and incubation times of photo-activated curcumin on the survival of S. mutans in planktonic and biofilm models of growth was assessed by flow cytometry. Streptococcus mutans in planktonic suspensions or biofilms formed on hydroxyapatite disks were incubated for 5 or 10min with curcumin prior to blue light activation. Bacteria were labeled with SYTO 9 and propidium iodide before viability was assessed by flow cytometry. Results were statistically analyzed using one-way ANOVA and Tukey multiple comparison intervals (α=0.05). For planktonic cultures, 0.2μM of light-activated curcumin significantly reduced S. mutans viability (p<0.05). For biofilm cultures, light-activated curcumin at concentration of 40-60μM only suppressed viability by 50% (p<0.05). Independently of the mode of growth, incubation time has no significant effect on PACT efficiency. This study indicates that blue light-activated curcumin can efficiently inactivate planktonic cultures of S. mutans whereas biofilms were more resistant to treatment. Flow cytometry allowed the detection of bacteria with damaged membranes that were unable to replicate and grow after cell sorting. Further studies seem warranted to optimize the efficacy of light-activated curcumin against S. mutans biofilms.

The effect of a commercial probiotic drink on oral microbiota in healthy complete denture wearers

BackgroundIt is acknowledged that oral and general health status declines with age. The global population of denture wearers is increasing, so is the incidence of denture biofilm-related problems, such as denture-associated stomatitis, aspiration pneumonia and malodour. It has been suggested that consumption of probiotic bacteria may improve oral health. However, the effects of probiotics on the oral microbiota of denture wearers have received little attention.MethodsThe aim of this study was to investigate the effect of consumption of a commercial probiotic product (Yakult) on microbiota of saliva, tongue and denture biofilm in healthy complete denture wearers. Eight healthy complete denture-wearing National Health Service (NHS) patients undertook a 7-week trial comprising three phases: baseline; 4-week consumption of one bottle of Yakult per day, each containing a minimum 6.5×109 viable cells of Lactobacillus casei strain Shirota (LcS); 4-week washout period. The microbial viability and composition of saliva, tongue dorsum coating and denture biofilm were assessed using a range of solid selective and indicator media. Questionnaires were used to explore participants’ denture cleaning habits and impact of wearing dentures on their life quality and well-being [modified oral health impact profile (OHIP-14)] prior to and after the study.ResultsSeven volunteers (1 male, 6 females) completed the trial. LcS temporarily colonised oral cavity and denture surface. There was no significant change in the viability of Streptococcus mutans, acidogenic microorganisms, total anaerobic species and Gram-negative obligate anaerobes between study phases. There was no obvious effect of LcS on occurrence and viability of Candida. Participants presented a good general knowledge of denture hygiene and their responses to OHIP-14 questionnaires improved after completing the study (p=0.16).ConclusionIt appeared that 4-week consumption of probiotic drink had no overall effect on selected oral parameters in healthy denture wearers despite temporary presence of LcS.

Photodynamic inactivation of Streptococcus mutans and Streptococcus sanguinis biofilms in vitro

The purpose of this study was to evaluate specific effects of photodynamic inactivation (PDI) using erythrosine (ER) and Rose Bengal (RB) photosensitizers and a blue light-emitting diode (LED) on the viability of Streptococcus mutans and Streptococcus sanguinis biofilms. Biofilms were grown in acrylic disks immersed in broth to production of biofilms, inoculated with microbial suspension (10(6) cells/mL) and incubated for 48 h. After the formation of biofilms, the effects of the photosensitizers ER and RB at a concentration of 5 μM for 5 min and blue LED (455 ± 20 nm) for 180 s, photosensitizers alone and conjugated were evaluated. Next, the disks were placed in tubes with sterile physiological solution (0.9 % sodium chloride) and sonicated for to disperse the biofilms. Tenfold serial dilutions were carried and aliquots seeded in brain heart infusion agar which were then incubated for 48 h. Then the numbers colony-forming units per milliliter (CFU/mL; log10) were counted and analyzed statistically (ANOVA, Tukey test, P ≤ 0.05). Significant decreases in the viability of all microorganisms were observed for biofilms exposed to PDI mediated by both photosensitizers. The reductions with RB and ER were, 0.62 and 0.52 log10 CFU mL(-1) for S. mutans biofilms (p=0.001), and 0.95 and 0.88 log10 CFU mL(-1) for S. sanguinis biofilms (p=0.001), respectively. The results showed that biofilms formed in vitro by S. mutans and S. sanguinis, were sensitive to PDI using a blue LED associated with photosensitizers ER or RB, indicating its use in the control of caries and periodontal diseases.

A novel furanone-modified antibacterial dental glass ionomer cement

A novel furanone derivative and a polyacid constructed from it were synthesized, characterized and formulated into experimental high strength cements. The compressive strength (CS) and Streptococcus mutans viability were used to evaluate the mechanical strength and antibacterial activity of the cements. The effect of human saliva and aging were investigated. The antibacterial activity against Lactobacillus sp. and cytotoxicity to human pulp cells were also evaluated. The results show that all the formulated furanone-containing cements showed antibacterial activity, with an initial reduction in CS. The effect of the furanone derivative loading was significant. Increasing loading enhanced the antibacterial activity but reduced the initial CS of the formed cements. The derivative showed antibacterial activity against both S. mutans and Lactobacillus sp. Human saliva did not affect the antibacterial activity of the cement. The cytotoxicity study with human dental pulp cells shows that the furanone-modified cement was biocompatible. A 30day aging study indicated that the cements may have long-lasting antibacterial activity. Within the limitations of this study it appears that the experimental cement could be a clinically attractive dental restorative due to its high mechanical strength and antibacterial function.

A novel antibacterial resin composite for improved dental restoratives

A novel furanone-containing antibacterial resin composite has been prepared and evaluated. compressive strength (CS) and Streptococcus mutans viability were used to evaluate the mechanical strength and antibacterial activity of the composites. The modified resin composites showed a significant antibacterial activity without substantially decreasing the mechanical strengths. With 5-30 % addition of the furanone derivative, the composite kept its original CS unchanged but showed a significant antibacterial activity with a 16-68 % reduction in the S. mutans viability. Further, the antibacterial function of the new composite was not affected by human saliva. The aging study indicates that the composite may have a long-lasting antibacterial function. Within the limitations of this study, it appears that the experimental antibacterial resin composite may potentially be developed into a clinically attractive dental restorative due to its high mechanical strength and antibacterial function.

Inhibition of Streptococcus mutans binding to hydroxylapatite using partially digested whey protein concentrate and individual whey proteins

The effect of a bovine whey protein concentrate partially digested with lipase to release free fatty acids (WPD) on growth and viability of Streptococcus mutans, and its adherence to hydroxylapatite (HA) in phosphate-buffered saline were examined. The effects of other whey mixtures and individual whey proteins, β-lactoglobulin (BLG), lactoferrin (LF), caseinoglycomacropeptide (CGMP) and α-lactalbumin were also investigated. Bacterial viability was assessed by incubation with whey protein and measuring colony-forming units. S. mutans binding was quantified using Syto-13 nucleic-acid binding dye and Alamar Blue, which measures cellular metabolic activity. WPD was bactericidal, and inhibited S. mutans growth and adhesion to HA. Other wheys inhibited S. mutans adhesion, particularly acid whey, as well as the parent compound for WPD, Carbelac 80, and a whey protein isolate. BLG, CGMP and LF inhibited S. mutans adhesion. A mixture containing 56% BLG and 20% CGMP was as effective an inhibitor of bacterial adhesion as WPD.

2P5-12 Effects of high-intensity ultrasound on the viability of Streptococcus mutans(Poster Session)

2P5-12 Effects of high-intensity ultrasound on the viability of Streptococcus mutans(Poster Session)

Preparation and evaluation of a novel glass-ionomer cement with antibacterial functions

Objective The objective of this study was to use the newly synthesized poly(quaternary ammonium salt) (PQAS)-containing polyacid to formulate the light-curable glass-ionomer cements and study the effect of the PQAS on the compressive strength and antibacterial activity of the formed cements. Materials and methods The functional QAS and their constructed PQAS were synthesized, characterized and formulated into the experimental high-strength cements. Compressive strength (CS) and Streptococcus mutans viability were used to evaluate the mechanical strength and antibacterial activity of the cements. Fuji II LC cement was used as control. The specimens were conditioned in distilled water at 37 °C for 24 h prior to testing. The effects of the substitute chain length, loading as well as grafting ratio of the QAS and aging on CS and S. mutans viability were investigated. Results All the PQAS-containing cements showed a significant antibacterial activity, accompanying with an initial CS reduction. The effects of the chain length, loading and grafting ratio of the QAS were significant. Increasing chain length, loading, grafting ratio significantly enhanced antibacterial activity but reduced the initial CS. Under the same substitute chain length, the cements containing QAS bromide were found to be more antibacterial than those containing QAS chloride although the CS values of the cements were not statistically different from each other, suggesting that we can use QAS bromide directly without converting bromide to chloride. The experimental cement showed less CS reduction and higher antibacterial activity than Fuji II LC. The long-term aging study suggests that the cements may have a long-lasting antibacterial function. Conclusions This study developed a novel antibacterial glass-ionomer cement. Within the limitations of this study, it appears that the experimental cement is a clinically attractive dental restorative due to its high mechanical strength and antibacterial function.

A novel antibacterial dental glass‐ionomer cement

This study reports the synthesis and evaluation of a novel non-leachable poly(quaternary ammonium salt) (PQAS)-containing antibacterial glass-ionomer cement. Fuji II LC cement was used for comparison. Compressive strength (CS) and Streptococcus mutans viability were used to evaluate strength and antibacterial activity, respectively. All specimens were conditioned in distilled water at 37 degrees C before testing. After the addition of 1-30% PQAS, both cements showed a reduction in CS, of 25-95% for Fuji II LC and 13-78% for the experimental cement, and a reduction in S. mutans viability, of 40-79% for Fuji II LC and 40-91% for the experimental cement. The experimental cement showed less CS reduction and higher antibacterial activity compared with Fuji II LC. The result also indicates that the cements are permanently antibacterial, with no leaching of PQAS. It appears that the experimental cement is a clinically attractive dental restorative that can be potentially used for longlasting restorations as a result of its high mechanical strength and permanent antibacterial function.

Effects of Short-Period Exposure to Antibacterial Monomer MDPB on Viability of Streptococcus mutans.

Effects of Short-Period Exposure to Antibacterial Monomer MDPB on Viability of Streptococcus mutans.

Effect of Psidium cattleianum Leaf Extract on Streptococcus mutans Viability, Protein Expression and Acid Production

Plants naturally produce secondary metabolites that can be used as antimicrobials. The aim of this study was to assess the effects of Psidium cattleianum leaf extract on Streptococcus mutans. The extract (100%) was obtained by decoction of 100 g of leaves in 600 ml of deionized water. To assess killing, S. mutans biofilms were treated with water (negative control) or various extract dilutions [100, 50, 25% (v/v) in water] for 5 or 60 min. To evaluate the effect on protein expression, biofilms were exposed to water or 1.6% (v/v) extract for 120 min, proteins were extracted and submitted to 2-dimensional difference gel electrophoresis. Differentially expressed proteins were identified by mass spectrometry. The effect of 1.6% (v/v) extract on acid production was determined by pH measurements and compared to a water control. Viability was similar after 5 min of treatment with the 100% extract or 60 min with the 50% extract (about 0.03% survival). There were no differences in viability between the biofilms exposed to the 25 or 50% extract after 60 min of treatment (about 0.02% survival). Treatment with the 1.6% extract significantly changed protein expression. The abundance of 24 spots was decreased compared to water (p < 0.05). The extract significantly inhibited acid production (p < 0.05). It is concluded that P. cattleianum leaf extract kills S. mutans grown in biofilms when applied at high concentrations. At low concentrations it inhibits S. mutans acid production and reduces the expression of proteins involved in general metabolism, glycolysis and lactic acid production.

光动力疗法对口腔生物膜中变形链球菌作用的研究

We investigated the effect of photodynamic therapy (PDT) with hematoporphyrin monomethyl ether (HMME) on the viability of Streptococcus mutans (S. mutans) cells on biofilms in vitro. Streptococcus mutans is the primary etiological agent of human dental caries. Since dental caries are localized infections, such plaque-related diseases would be well suited to PDT. The diode laser used in this study had the wavelength of 635 nm, whose output power was 10 mW and the energy density was 12.74 J/cm2. HMME was used as photosensitizer. Samples were prepared and divided into five groups: (1) HMME; (2) Laser; (3) HMME+Laser; (4) Control group (+) with chlorhexidine; and (5) Control group (-) with sterile physiological saline. Inoculum of S. mutans incubated with HMME also examined with fluorescence microscopy. PDT exhibited a significantly (Pl0.05) increased antimicrobial potential compared with 20 \mum/mL HMME only, laser only, 0.05% chlorhexidine, and 0.9% sterile physiological saline, which reduced the S. mutans of the biofilm most effectively. Laser and 0.05% chlorhexidine were caused reduction in the viable counts of S. mutans significantly different (Pl0.05) also, but these two test treatments did not statistically differ from each other. HMME group did not statistically differ with negative control group. Fluorescence microscopy indicated that HMME localized primarily in the S. mutans of the biofilm. It was demonstrated that HMME-mediated PDT was efficient at killing S. mutans of biofilms and a useful approach in the treatment of dental plaque-related diseases.

In vitro effects of a fraction separated from Polygonum cuspidatum root on the viability, in suspension and biofilms, and biofilm formation of mutans streptococci

Polygonum cuspidatum (Polygonaceae) has traditionally been used in folk medicine to control oral diseases. Nevertheless, there are no reports related to its possible effect on the diseases, particularly on biofilm-related diseases such as dental caries. In this study, we evaluated in vitro effects of a fraction separated from Polygonum cuspidatum root on the viability, in both suspension and biofilms, and the biofilm formation of mutans streptococci. The separated fraction (F1) showed bacteriostatic and bactericidal activity against mutans streptococci in suspension, with minimum inhibitory concentration (MIC) range of 31.3–250 μg/ml and minimum bactericidal concentration (MBC) range of 0.5–1 mg/ml. At a concentration of 1.5 mg/ml, F1 killed approximately 2 log 10 CFU/ml of Streptococcus mutans and Streptococcus sobrinus after 2 h of exposure. In biofilms, F1 also inhibited the viability of Streptococcus mutans and Streptococcus sobrinus, dependent on the biofilm age, the concentration of F1, and the treatment time. Four hours of exposure to 1.5 mg/ml F1 reduced the viable counts of Streptococcus mutans and Streptococcus sobrinus by greater than 2 log 10 CFU/disc. Furthermore, at sub-MIC levels, F1 inhibited biofilm formation by Streptococcus mutans and Streptococcus sobrinus in a dose-dependent fashion. Based on the preliminary phytochemical analysis, the activity of F1 may be related to the presence of anthraquinones, cardiac glycosides, terpenoids, and phenolics. These results indicate that F1 is probably useful in the control of oral biofilms and subsequent dental caries development.

Pharmacologically Active Boranes

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