The Antibacterial Activities of Copper Oxide Nanoparticles Synthesized Using Laser Ablation in Different Surfactants against Streptococcus mutans

Copper oxide nanoparticles(CuO NPs)were synthesised with laser ablation of a copper sheet immersed in deionized water(DW),cetrimonium bromide(CTAB),and sodium dodecyl sulphate(SDS),respectively.The target was irradiated with a pulsed Nd:YAG laser at 1064 nm,600 mJ,a pulse duration of 10 ns,and a repetition rate of 5 Hz.The CuO NPs colloidal were analyzed using UV–Vis spectroscopy,the Fourier transform infrared(FTIR)spectrometer,zeta potential(ZP),X-ray diffraction(XRD),transmission electron microscope(TEM)and field emission scanning electron microscopy(FESEM).The absorption spectra of CuO NPs colloidal showed peaks at 214,215 and 220 nm and low-intensity peaks at 645,650 and 680 nm for SDS,CTAB and DW,respectively.CuO NPs’colloidal results are(−21.6,1.2,and 80 mV)for negatively,neutrally,and positively charged SDS,DW,and CTAB,respectively.The XRD pattern of the NPs revealed the presence of CuO phase planes(110)(111),(20-2)and(11-1).The TEM images revealed nearly spherical NPs,with sizes ranging from 10–90,10–50,and 10–210 nm for CuO NPs mixed with DW,SDS and CTAB,respectively.FESEM images of all the synthesized samples illustrate the formation of spherical nanostructure and large particles are observable.The CuO NPs were tested for antibacterial activity against Streptococcus mutans by using the well diffusion method.In this method,CuO NPs prepared in DW at a concentration of 200μg/mL showed a greater inhibition zone against Streptococcus mutans.

In silico identification of potential inhibitors targeting Streptococcus mutans sortase A

Dental caries is one of the most common chronic diseases and is caused by acid fermentation of bacteria adhered to the teeth.Streptococcus mutans(S. mutans) utilizes sortase A(Srt A) to anchor surface proteins to the cell wall and forms a biofilm to facilitate its adhesion to the tooth surface. Some plant natural products, especially several flavonoids, are effective inhibitors of Srt A. However, given the limited number of inhibitors and the development of drug resistance, the discovery of new inhibitors is urgent. Here, the high-throughput virtual screening approach was performed to identify new potential inhibitors of S. mutans Srt A. Two libraries were used for screening, and nine compounds that had the lowest scores were chosen for further molecular dynamics simulation, binding free energy analysis and absorption, distribution, metabolism, excretion and toxicity(ADMET)properties analysis. The results revealed that several similar compounds composed of benzofuran, thiadiazole and pyrrole, which exhibited good affinities and appropriate pharmacokinetic parameters, were potential inhibitors to impede the catalysis of Srt A.In addition, the carbonyl of these compounds can have a key role in the inhibition mechanism. These findings can provide a new strategy for microbial infection disease therapy.

Quaternary ammonium-induced multidrug tolerant Streptococcus mutans persisters elevate cariogenic virulence in vitro

Dental caries are the most prevalent chronic infections in the oral cavity, and Streptococcus mutans acts as the main cariogenic bacterial species. Antibacterial quaternary ammonium compounds(QAs) have been developed to preve Fnt or treat dental caries.However, there is no report on the tolerance of S. mutans to QAs. In this study, we investigated the development of S. mutans persistence induced by a novel dental caries defensive agent, dimethylaminododecyl methacrylate(DMADDM), for the first time.Typical biphasic killing kinetics for persisters were observed in both S. mutans planktonic and biofilm cultures challenged by DMADDM at concentrations of 20 and 200 μg·m L^(-1), respectively. The persisters tolerated six other antibiotics with different antibacterial mechanisms, while only daptomycin and vancomycin could slightly reduce the persister numbers in planktonic cultures. The distribution of persisters in DMADDM-treated biofilms was similar to that in the untreated control, except that the total biomass and biofilm height were significantly reduced. A higher exopolysaccharides(EPS):bacteria ratio was observed in DMADDM-treated biofilms. Persisters in biofilms significantly upregulated gtf gene expression, indicating an increase in the bacteria's ability to produce EPS and an elevated capability of cariogenic virulence. Carbon source metabolism was significantly reduced, as related metabolic genes were all downregulated in persisters. Concentrations of 0.1 m M, 1 m M and 10 m M of extra glucose significantly reduced the number of persisters both in planktonic and biofilm conditions. The formation of noninheritable and multidrug tolerant persisters induced by DMADDM suggested that drug tolerance and new persistent eradication strategies should be considered for oral antibacterial agents.

The synergistic effect of honey and cinnamon against Streptococcus mutans bacteria

Objective: To investigate the effect of Iranian honey, cinnamon and their combination against Streptococcus mutans bacteria.Methods: Nine experimental solutions were examined in this study, including two types of honey(pasteurized and sterilized), two types of cinnamon extract(dissolved in distilled water or dimethyl sulfoxide) and five different mixtures of cinnamon in honey(prepared by admixing 1%–5% w/w of cinnamon extract into 99%–95% w/w of honey, respectively).Meanwhile, each of mentioned agent was considered as the first solution while it was diluted into seven serially two-fold dilutions(from 1:2 to 1:128 v/v).Therefore, eight different concentrations of each agent were tested.The antibacterial tests were performed through blood agar well diffusion method, and the minimum inhibitory concentration(MIC) was determined.Ultimately, the data were subjected to statistical analysis incorporating Two-way ANOVA and Bonferroni post hoc tests(a = 0.01).Results: The highest zone of inhibition was recorded for the mixtures of honey and cinnamon while all the subgroups containing 95%–99% v/v of honey were in the same range(P < 0.01).The MIC for both honey solutions were obtained as 500 mg/mL whereas it was 50 mg/m L for both cinnamon solutions.Moreover, the MIC related to all honey/cinnamon mixtures were 200 mg/mL.Conclusions: A profound synergistic effect of honey and cinnamon was observed against Streptococcus mutans while there was no significant difference among extracts containing 99%–95% v/v of honey admixing with 1%–5% v/v of cinnamon, respectively.

Construction and in vitro Expression of Streptococcus Mutans Surface Protein Encoding DNA Vaccine

DNA vaccine plasmids were constructed that encoded two highly conservative regions of a surface protein, PAc, from the human major cariogenic bacterium, Streptococcus mutans . Antigen expression was evaluated in vitro by immunohistochemical analysis of human endothelial cells following cationic liposome mediated transient transfection with recombinant plasmid. The results of this study provided a basis for further testing of these recombinant plasmids in primates and for efficacy testing of dental caries DNA vaccines in human volunteers in future.

Streptococcal SspB Peptide Analog Inhibits Saliva-Promoted Adhesion and Biofilm Formation of Streptococcus mutans

Background: Streptococcus gordonii, a pioneer colonizer of dental plaque biofilm, expresses surface protein adhesin SspB by which the bacteria bind to salivary agglutinin (gp340). SspB has extensive homology with PAc, a surface adhesin of Streptococcus mutans. Hence, SspB of S. gordonii competes with PAc of S. mutans for the same niche environment in the salivary pellicles. The aim of this study was to develop anti-adherence agents that enabled us to control cariogenic biofilms by using the streptococcal SspB peptide analog SspB (A4K-A11K). Methods: First, we performed ELISA to determine the S. mutans-saliva interaction and saliva-binding activities of SspB (A4K- A11K). The inhibitory effects of SspB (A4K-A11K) were then evaluated by examining S. mutans adhesion to saliva-coated hydroxyapatite disks (s-HA). To determine peptide interference with biofilm formation, S. mutans biofilms were quantified by counting CFUs on MS agar plates and by measuring the absorbance at 492 nm of safranin-stained biofilms on s-HA. Results: Saliva, particularly salivary gp340 peptide, promoted adherence of S. mutans to polystyrene surfaces. SspB (A4K-A11K) significantly bound to saliva and inhibited the adhesion of S. mutans to s-HA without bactericidal activity. Furthermore, biofilms of S. mutans on s-HA were successfully reduced by pretreatment with SspB (A4K-A11K). Conclusion: SspB (A4K-A11K) peptide competitively blocked S. mutans adhesion to experimental pellicles through SspB-gp340 interaction, thereby inhibiting biofilm formation. These findings will contribute to the control cariogenic biofilms.

Periodontitis and Inflammation: Plasma High Titer Naturally Occurring Anti-Glucan Antibodies Form Immune Complex with Streptococcus mutans Antigen

Atheromatous plaques usually contain antigens of the periodontitis-causing bacteria Streptococcus mutans though molecular mechanism of this incorporation remains unknown. Since vascular adhesion and inflammatory potential of Immune Complexes (IC) are known we investigated the naturally occurring plasma antibodies that recognize major antigens from S. mutans. S. mutans-binding plasma proteins (SMBP) prepared by affinity chromatography on a column of heat-killed S. mutans could recognize α- and β-linked glucose in dextran and yeast respectively but not galactose in glycoproteins. SMBP contained only three proteins, each corresponding in electrophoretic mobility to standard plasma IgG, IgA or IgM. The major positively and negatively charged protein antigens (PSMAg and NSMAg) isolated from S. mutans by electrophoresis and ion exchange chromatography respectively were recognized sugar-reversibly by the anti-β-glucan antibody (ABG) and though less avidly, by the dextran-binding immunoglobulin (DIg) in normal plasma. NSMAg addition resulted in near doubling of IC-bound immunoglobulins in immunoglobulin-rich fraction of plasma. IC isolated from above fraction after NSMAg addition had substantially more IgA and IgM content than total plasma immunoglobulins. IC formation by NSMAg was significantly inhibited by ABG- and DIg-specific sugars or by selective withdrawal of ABG or DIg from plasma. ABG and DIg being relatively high titer plasma antibodies IC formation with them suggested a possible route for vascular adhesion and damage by S. mutans and its antigens. Further, high IgA content of these ICs indicated their susceptibility to tissue uptake through cell surface galectin-1 for which IgA is the lone immunoglobulin ligand.

COMPARATIVE STUDY OF GREEN TEA POLYPHENOL AND FLUORIDE ON STREPTOCOCCUS MUTANS

Objective To disclose the mechanism of green tea polyphenol in the prevention ol dental caries.ththods Using sodium fluoride (highly effective anticaries agent) as control and Streptococcus mutans(carigenous microbe) as target, green tea polyphenol (potential bacterial inhibitor) was used to testify its action onthe change of microbial morphology, extramicrobial sucrase, glucosyltranslerase (GTF), lactate hydrogenase (LDH),protein and pH values of the culture media. Results GTF activities were inhibited both by green tea polyphenoland sodium fluoride, the inhibitory ellcacy was stronger in green tea polyphenol. Morphologic changes consisted ofmembrane disroption in tea polyphenol treated microbes, and cytoplasmic vacuolization in fluoride treated bacteria.High protein level in fluoride treated culture media means cytoplasmic decomposition, intracellular protein leakageinto media. Conclusion The inhibition of GTF activity was stronger in green tea polyphenol treated microbes.The target of action was cell membrane disruption in green tea polyphenol treated cell and cytoplasmic in fluoridetreated microbes.

Quantitative detection of Streptococcus mutans from saliva using FTA^(TM) elute cards and real-time polymerase chain reaction

Dental caries is a localized, transmissible, pathological infection process that ends up in the destruction of hard dental tissue. Numerous reports have shown the close relationship between salivary levels of Streptococcus mutans and dental caries. As S. mutans, is considered to be the principle etiological agent of dental caries, the development of a quick and convenient method for detection and quantification of these bacteria from patient saliva samples would simplify diagnosis and treatment. The purpose of this study was to compare a new means of quantifying bacteria using FTATM Elute cards and Real-Time Polymerase Chain Reaction to a conventional culture-based assay using oral S. mutans as a model sample. A total of 60 different saliva samples were investigated. The results show a significant negative correlation between the two methods, with a correlation coefficient of -0.577 (Spearman’s Correlation) and p < 0.01. The method demonstrates a high sensitivity, specificity and reliable quantitative results, covering a large range of bacterial concentrations.

Improved corrosion resistance and biofilm inhibition ability of copper-bearing 304 stainless steel against oral microaerobic Streptococcus mutans

304 stainless steel(SS) used as orthodontic wire during orthodontics faces the risk of microbiologically influenced corrosion(MIC) due to diverse flora environment. Hereinto, Streptococcus mutans(S. mutans)is the most important cariogenic bacteria. In this work, MIC behavior of a new 304-Cu SS in presence of S. mutans was studied by the observations using scanning electron microscopy(SEM) and confocal laser scanning microscopy(CLSM) including live/dead staining, extracellular polymeric substance(EPS)staining and pitting corrosion, electrochemical test, and X-ray photoelectron spectroscopy(XPS). Above results showed that 304-Cu SS possessed excellent biofilm inhibition ability and presented lower corrosion current density(icorr), larger polarization resistance(Rp) and charge transfer resistance(Rct) in the presence of S. mutans, indicating that 304-Cu SS had a better MIC resistance against S. mutans. It was further affirmed by XPS results that the presence of Cu-oxide in passive film of 304-Cu SS inhibited the formation of biofilm.

Potential of photodynamic therapy in the management of infectious oral diseases

Photodynamic therapy(PDT)can take place in the presence of three elements:Light with an appropriate wavelength;a photosensitizer;and the presence of oxygen.This type of treatment is very effective overall against bacterial,viral and mycotic cells.In the last 10 years many papers have been published on PDT with different types of photosensitizers(e.g.,methylene blue,toluidine blue,indocyanine green,curcumin-based photosensitizers),different wavelengths(e.g.,460 nm,630 nm,660 nm,810 nm)and various parameters(e.g.,power of the light,time of illumination,number of sessions).In the scientific literature all types of PDT seem very effective,even if it is difficult to find a standard protocol for each oral pathology.PDT could be an interesting way to treat some dangerous oral infections refractory to common pharmacological therapies,such as candidiasis from multidrug-resistant Candida spp.

Antimicrobial Activity of Some Commercial Toothpastes and Antibiotics on Two Oral Pathogenic Bacteria—An in-Vitro Study

Oral health problems such as periodontal diseases, dental caries, and endodontic infections have a significant negative impact on oral health and impose a substantial financial burden on the global population. The prevalence of these issues is increasing due to the buildup of bacterial plaque and the growing resistance of bacteria to antimicrobial treatments. The aims of this study to evaluate the anti-bacterial activity of four types of antibiotics (Amoxicillin, Augmentin, Azithromycin and Metronidazole) and four types of toothpastes (Sensodyne, ipana, denta and cariax Gingival Kin) on two oral pathogenic bacteria (Streptococcus mutans and Staphylococcus epidermidis). Bacterial samples of previously isolated Streptococcus mutans and Staphylococcusepidermidis were used as test organisms and the Kirby-Bauer disc diffusion method was employed to assess the antibacterial efficacy of various antibiotics and evaluate the impact of different toothpastes using a filter paper disc agar measurement technique. Each filter disc was saturated with toothpaste solution in a test tube for approximately 30 to 40 seconds, after which they were placed on Mueller-Hinton broth bacterial cultures in petri dishes. These Petri dishes were then incubated at 37°C for 24 hours, and the clear zone’s diameter (inhibition zone in mm) was subsequently measured and the results were recorded. The results demonstrated that Sensodyne toothpaste and Metronidazole antibiotic were ineffective against both types of bacteria, while Augmentin and Amoxicillin were effective by high diameter inhibition zones of growth against S. mutans and Azithromycine against S. epidermidis. Also Ipana, Denta, and Cariax Gingival Kin toothpastes exhibited a moderate effect against the two bacteria. This study suggests that certain antibiotics and toothpastes can effectively inhibit the growth of harmful oral bacteria, but not all of them are effective.

mapZ基因缺失对变异链球菌生长分裂及氯己定作用下生物膜形成能力的影响

探究变异链球菌(Streptococcus mutans)分裂调控基因mapZ缺失对变异链球菌生长分裂、氯己定(Chlorhexidine,CHX)作用下生物膜形成能力的影响。针对前期课题组成功构建的变异链球菌的mapZ基因缺失突变株(ΔsmmapZ),通过扫描电镜(SEM)观察细菌细胞生长形态及分裂隔膜的位置变化;通过实时定量PCR技术检测mapZ基因缺失对分裂基因ftsZ相对表达含量的影响;通过检测氯己定最小抑菌浓度(MIC)并在不同药物浓度下培养生物膜来探究mapZ基因缺失对变异链球菌生物膜形成能力的影响。结果表明:与野生株相比,ΔsmmapZ突变株形态发生改变(变为短圆球状),分裂隔膜位置错乱;ΔsmmapZ突变株分裂基因ftsZ相对表达含量较UA159下降四分之一,具有统计学差异;ΔsmmapZ突变株MIC值为0.12500μg/mL,UA159野生株MIC值为0.25000μg/mL,且在药物浓度为0.12500μg/mL的氯己定作用下,野生株可以形成生物膜,而ΔsmmapZ则无生物膜形成。变异链球菌缺失mapZ基因影响细菌细胞的胞质分裂,降低分裂基因ftsZ的表达和氯己定下变异链球菌生物膜的形成能力。mapZ可作为潜在的抗菌药物研发靶点。

Antimicrobial Activity of Traditional Chinese Medicines on Common Oral Bacteria

Objective: To evaluate twenty Traditional Chinese Medicines (TCM) against four oral bacteria. Methods: Twenty TCM were tested for sensitivity against Streptococcus mitis, Streptococcus sanguis, Streptococcus mutans and Porphyromonas gingivalis. Aliquots of suspension of each bacterial species were inoculated on a horse blood agar (HBA) plate, 6 mm diameter paper disks was soaked in different drug suspensions were placed concentrically on a HBA plate. Disks soaked in 0.2% w/v chlorhexidine were used as positive controls. These HBA plates were incubated for 48 hours anaerobically and the diameters of growth inhibition of three different areas were measured using a calibrated computer software and the mean diameter obtained for each bacteria. Broth microdilution assay was used to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The experiment was repeated on three separate occasions. Results: The TCMs that consistently against Porphyromonas gingivalis, included Folium artemisiae argyi, Fructus crataegi, Rhizoma dryopteris crassirhizomae, Flos magnoliae, Rhizoma polygoni cuspidati, Radix scrophulariae ningpoensis, Galla chinensis, Radix scutellariae baicalensis and Rhizoma coptidis;against Streptococcus mutans included Fructus crataegi, Galla chinensis and Rhizoma copitidis;against Streptococcus mitis and Streptococcus sanguis included Galla chinensis and Rhizoma copitidis. Conclusion: Rhizoma copitidis and Galla chinensis had inhibitory effects on Streptococcus mitis, Streptococcus sanguis, Streptococcus mutans and Porphyromonas gingivalis in vitro.

Antibacterial property of a gradient Cu-bearing titanium alloy by laser additive manufacturing

Streptococcus mutans(S.mutans)is the most common cariogenic bacteria and causes caries by forming biofilms.A novel gradient Cu-bearing titanium alloy(TC4-5Cu/TC4)was manufactured using selective laser melting(SLM)technology for dental applications,which is anticipated to inhibit the formation of biofilm.In this study,the released concentration of copper ions in both minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)was tested in order to assess the antibacterial property of the alloy against planktonic S.mutans,and the antibacterial and antibiofilm efficiencies of TC4-5Cu/TC4 alloy against sessile S.mutans were evaluated via quantitative antibacterial tests and biofilm determination.Reverse transcription polymerase chain reaction(RT-PCR)was performed to analyze the expression of biofilm-related genes(gtfB,gtfC,gtfD,ftf and gbpB)and acid production-related gene(ldh).The results suggested that the MIC and MBC of Cu^(2+)were much higher than the release concentration of copper ions of the alloy,which was consistent with the lack of antibacterial effect against planktonic bacteria.On the contrary,TC4-5Cu/TC4 alloy exhibited significant bactericidal property against the sessile bacteria and efficient biofilm-restrained ability,and all genes detected in this research were down-regulated.The results indicated that the TC4-5Cu/TC4 alloy suppressed biofilm formation and the sessile bacterial viability by down-regulating biofilm-related genes.