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Cellular and Molecular Biology... Mar 2024Osteoinduction, and/or osteoconduction, and antibacterial characteristics are prerequisites for achieving successful bone grafting. This study aimed to coat bone...
Osteoinduction, and/or osteoconduction, and antibacterial characteristics are prerequisites for achieving successful bone grafting. This study aimed to coat bone allografts with silver nanoparticles and assess their antibacterial activity and biocompatibility compared to uncoated bone allografts. In this study, the bone allografts were coated with varying concentrations of silver nanoparticles (5 mg/l, 10 mg/l, and 50 mg/l) through a simple adsorption technique. Subsequently, the coated samples underwent characterization using SEM, FTIR, EDS, and XRD. The Minimal Inhibitory Concentration (MIC) of the silver nanoparticles was determined against Staphylococcus aureus and Streptococcus mutans. Bacterial growth inhibition was evaluated by measuring turbidity and performing a disk diffusion test. Moreover, qualitative investigation of biofilm formation on the coated bone allograft was conducted using SEM. Following this, MG-63 cell lines, resembling osteoblasts, were cultured on the bone allografts coated with 5 mg/l of silver nanoparticles, as well as on uncoated bone allografts, to assess biocompatibility. The MIC results demonstrated that silver nanoparticles exhibited antimicrobial effects on both microorganisms, inhibiting the growth of isolates at concentrations of 0.78 mg/L for Staphylococcus aureus and 0.39 mg/L for Streptococcus mutans. The bone allografts coated with varying concentrations of silver nanoparticles exhibited significant antibacterial activity against the tested bacteria, completely eradicating bacterial growth and preventing biofilm formation. The osteoblast-like MG-63 cells thrived on the bone allografts coated with 5 mg/l of silver nanoparticles, displaying no significant differences compared to both the uncoated bone allografts and the control group. Within the limit of this study, it can be concluded that silver nanoparticles have a positive role in controlling graft infection. In addition, simple adsorption technique showed an effective method of coating without overwhelming the healing of the graft.
Topics: Silver; Metal Nanoparticles; Anti-Bacterial Agents; Streptococcus mutans; Staphylococcus aureus; Humans; Microbial Sensitivity Tests; Biofilms; Bone Substitutes; Allografts; Coated Materials, Biocompatible; Bone Transplantation; Materials Testing; Cell Line
PubMed: 38650153
DOI: 10.14715/cmb/2024.70.3.10 -
Microbial Pathogenesis Jun 2024Pseudomonas aeruginosa is often identified as the causative agent in nosocomial infections. Their adapted resistance makes them strong towards antimicrobial treatments....
Pseudomonas aeruginosa is often identified as the causative agent in nosocomial infections. Their adapted resistance makes them strong towards antimicrobial treatments. They protect and empower their survival behind strong biofilm architecture that works as their armor toward antimicrobial therapy. Additionally, P. aeruginosa generates virulence factors, contributing to chronic infection and recalcitrant phenotypic characteristics. The current study utilizes the benevolence of nanotechnology to develop an alternate technique to control the spreading of P. aeruginosa by limiting its biofilm and virulence development. This study used a natural compound, tetramethylpyrazine, to generate gold nanoparticles. Tetramethylpyrazine-gold nanoparticles (Tet-AuNPs) were presented in spherical shapes, with an average size of 168 ± 52.49 nm and a zeta potential of -12.22 ± 2.06 mV. The minimum inhibition concentration (MIC) of Tet-AuNPs that proved more than 90 % effective in inhibiting P. aeruginosa was 256 μg/mL. Additionally, it also shows antibacterial activities against Staphylococcus aureus (MIC, 256 μg/mL), Streptococcus mutans (MIC, 128 μg/mL), Klebsiella pneumoniae (MIC, 128 μg/mL), Listeria monocytogenes (MIC, 256 μg/mL), and Escherichia coli (MIC, 256 μg/mL). The sub-MIC values of Tet-AuNPs significantly inhibited the early-stage biofilm formation of P. aeruginosa. Moreover, this concentration strongly affected hemolysis, protease activity, and different forms of motilities in P. aeruginosa. Additionally, Tet-AuNPs destroyed the well-established mature biofilm of P. aeruginosa. The expression of genes linked with the biofilm formation and virulence in P. aeruginosa treated with sub-MIC doses of Tet-AuNPs was shown to be significantly suppressed. Gene expression studies support biofilm- and virulence-suppressing effects of Tet-AuNPs at the phenotypic level.
Topics: Biofilms; Gold; Pseudomonas aeruginosa; Virulence Factors; Anti-Bacterial Agents; Pyrazines; Microbial Sensitivity Tests; Metal Nanoparticles; Staphylococcus aureus; Escherichia coli; Klebsiella pneumoniae; Streptococcus mutans; Listeria monocytogenes
PubMed: 38643850
DOI: 10.1016/j.micpath.2024.106658 -
Archives of Oral Biology Jul 2024The present study investigated the effects of 4-hydroxy-3-methoxybenzaldehyde (4-H-3-MB) against Streptococcus mutans (S. mutans) using an in vitro cariogenic biofilm...
OBJECTIVE
The present study investigated the effects of 4-hydroxy-3-methoxybenzaldehyde (4-H-3-MB) against Streptococcus mutans (S. mutans) using an in vitro cariogenic biofilm model.
DESIGN
The antimicrobial susceptibility of biofilm-forming S. mutans was evaluated by disc diffusion method. In vitro investigations were performed using crystal violet staining assay (biofilm assay), exopolysaccharide (EPS) assay, acid production, growth curve analysis, optical microscopic, and FE-SEM analyses to determine the antibiofilm activity of 4-H-3-MB.
RESULTS
S. mutans (SDC-05) was resistant to ampicillin, piperacillin/tazobactam and ceftriaxone, whereas the other strains of S. mutans (SDC-01, 02, 03 and SDC-04) were sensitive to all the antibiotics tested. 4-H-3-MB showed promising antibiofilm activity on S. mutans UA159 (79.81 %, 67.76 % and 56.31 %) and S. mutans SDC-05 (77.00 %, 59.48 % and 48.22 %) at the lowest concentration of 0.2, 0.1, 0.05 mg/ml. 4-H-3-MB did not inhibit bacterial growth even at concentrations 0.2 mg/ml. Similarly, 4-H-3-MB led to significant attrition in exopolysaccharide (EPS) and acid production by S. mutans UA159 and S. mutans (SDC-05) at the concentration of 0.2, 0.1 mg/ml, respectively. Optical microscopy and FE-SEM analysis 4-H-3-MB reduced the biofilm thickness of S. mutans UA159 and S. mutans SDC-05 relative to the untreated specimens.
CONCLUSION
4-H-3-MB significantly inhibited biofilm formation by S. mutans in a dose-dependent manner. Hence, our findings indicate that the active principle of 4-H-3-MB could be used as a biofilm inhibiting agent against S. mutans.
Topics: Streptococcus mutans; Biofilms; Quorum Sensing; Benzaldehydes; Microbial Sensitivity Tests; Virulence Factors; Anti-Bacterial Agents; Polysaccharides, Bacterial; Microscopy, Electron, Scanning; In Vitro Techniques
PubMed: 38640776
DOI: 10.1016/j.archoralbio.2024.105976 -
Journal of Trace Elements in Medicine... Jul 2024S. mutans has been identified as the primary pathogenic bacterium in biofilm-mediated dental caries. The biogenic selenium nanoparticles (SeNPs) produced by L. plantarum...
INTRODUCTION
S. mutans has been identified as the primary pathogenic bacterium in biofilm-mediated dental caries. The biogenic selenium nanoparticles (SeNPs) produced by L. plantarum KNF-5 were used in this study against S. mutans ATCC 25175.
OBJECTIVES
The aims of this study were: (1) the biosynthesis of SeNPs by L. plantarum KNF-5, (2) the characterization of SeNPs, (3) the investigation of the inhibitory effect of biogenic SeNPs against S. mutans ATCC 25175, and (4) the determination of the anti-biofilm potential of SeNPS against S. mutans ATCC 25175.
METHODOLOGY
3 mL of the culture was added to 100 mL of MRS medium and incubated. After 4 h, NaSeO solution (concentration 100 μg/mL) was added and incubated at 37 °C for 36 h. The color of the culture solution changed from brownish-yellow to reddish, indicating the formation of SeNPs. The characterization of SeNPs was confirmed by UV-Vis spectrophotometry, FTIR, SEM-EDS and a particle size analyzer. The antibacterial activity was determined by the disk diffusion method, the MIC by the micro-double dilution method, and the biofilm inhibitory potential by the crystal violet method and the MTT assay. The effect of SeNPs on S. mutans ATCC 25175 was determined using SEM and CLSM spectrometry techniques. The sulfate-anthrone method was used to analyze the effect of SeNPs on insoluble extracellular polysaccharides. The expression of genes in S. mutans ATCC 25175 was analyzed by real-time quantitative polymerase chain reaction (RT-qPCR).
PREPARATION OF NANOPARTICLES
SeNPs produced by probiotic bacteria are considered a safe method. In this study, L. plantarum KNF-5 (probiotic strain) was used for the production of SeNPs.
RESULTS
The biogenic SeNPs were spherical and coated with proteins and polysaccharides and had a diameter of about 270 nm. The MIC of the SeNPs against S. mutans ATCC 25175 was 3.125 mg/mL. Biofilm growth was also significantly suppressed at this concentration. The expression of genes responsible for biofilm formation (GtfB, GtfC, BrpA and GbpB,) was reduced when S. mutans ATCC 25175 was treated with SeNPs.
CONCLUSION
It was concluded that the biogenic SeNPs produced by L. plantarum KNF-5 was highly effective to inhibit the growth of S. mutans ATCC 25175.
NOVELTY STATEMENT
The application of biogenic SeNPs, a natural anti-biofilm agent against S. mutans ATCC 25175. In the future, this study will provide a new option for the prevention and treatment of dental caries.
Topics: Streptococcus mutans; Biofilms; Selenium; Nanoparticles; Anti-Bacterial Agents; Microbial Sensitivity Tests; Lactobacillus plantarum; Particle Size
PubMed: 38626650
DOI: 10.1016/j.jtemb.2024.127448 -
MBio May 2024Microorganisms resist fluoride toxicity using fluoride export proteins from one of several different molecular families. Cariogenic species and extrude intracellular...
UNLABELLED
Microorganisms resist fluoride toxicity using fluoride export proteins from one of several different molecular families. Cariogenic species and extrude intracellular fluoride using a CLC F/H antiporter and FEX fluoride channel, respectively, whereas oral commensal eubacteria, such as export fluoride using a Fluc fluoride channel. In this work, we examine how genetic knockout of fluoride export impacts pathogen fitness in single-species and three-species dental biofilm models. For biofilms generated using with the genetic knockout of the CLC transporter, exposure to low fluoride concentrations decreased counts, synergistically reduced the populations of , increased the relative proportion of oral commensal , and reduced properties associated with biofilm pathogenicity, including acid production and hydroxyapatite dissolution. Biofilms prepared with with genetic knockout of the FEX channel also exhibited reduced fitness in the presence of fluoride but to a lesser degree. Imaging studies indicate that is highly sensitive to fluoride, with the knockout strain undergoing complete lysis when exposed to low fluoride for a moderate amount of time. Biochemical purification of the CLC transporter and functional reconstitution establishes that the functional protein is a dimer encoded by a single gene. Together, these findings suggest that fluoride export by oral pathogens can be targeted by specific inhibitors to restore biofilm symbiosis in dental biofilms and that is especially susceptible to fluoride toxicity.
IMPORTANCE
Dental caries is a globally prevalent condition that occurs when pathogenic species, including and , outcompete beneficial species, such as , in the dental biofilm. Fluoride is routinely used in oral hygiene to prevent dental caries. Fluoride also has antimicrobial properties, although most microbes possess fluoride exporters to resist its toxicity. This work shows that sensitization of cariogenic species and to fluoride by genetic knockout of fluoride exporters alters the microbial composition and pathogenic properties of dental biofilms. These results suggest that the development of drugs that inhibit fluoride exporters could potentiate the anticaries effect of fluoride in over-the-counter products like toothpaste and mouth rinses. This is a novel strategy to treat dental caries.
Topics: Biofilms; Candida albicans; Streptococcus mutans; Fluorides; Streptococcus gordonii; Gene Knockout Techniques; Bacterial Proteins; Dental Caries
PubMed: 38624207
DOI: 10.1128/mbio.00184-24 -
PLoS Pathogens Apr 2024Post-transcriptional regulation by small RNAs and post-translational modifications (PTM) such as lysine acetylation play fundamental roles in physiological circuits,...
Post-transcriptional regulation by small RNAs and post-translational modifications (PTM) such as lysine acetylation play fundamental roles in physiological circuits, offering rapid responses to environmental signals with low energy consumption. Yet, the interplay between these regulatory systems remains underexplored. Here, we unveil the cross-talk between sRNAs and lysine acetylation in Streptococcus mutans, a primary cariogenic pathogen known for its potent acidogenic virulence. Through systematic overexpression of sRNAs in S. mutans, we identified sRNA SmsR1 as a critical player in modulating acidogenicity, a key cariogenic virulence feature in S. mutans. Furthermore, combined with the analysis of predicted target mRNA and transcriptome results, potential target genes were identified and experimentally verified. A direct interaction between SmsR1 and 5'-UTR region of pdhC gene was determined by in vitro binding assays. Importantly, we found that overexpression of SmsR1 reduced the expression of pdhC mRNA and increased the intracellular concentration of acetyl-CoA, resulting in global changes in protein acetylation levels. This was verified by acetyl-proteomics in S. mutans, along with an increase in acetylation level and decreased activity of LDH. Our study unravels a novel regulatory paradigm where sRNA bridges post-transcriptional regulation with post-translational modification, underscoring bacterial adeptness in fine-tuning responses to environmental stress.
Topics: Animals; Acetylation; Bacterial Proteins; Dental Caries; Gene Expression Regulation, Bacterial; Protein Processing, Post-Translational; RNA, Bacterial; RNA, Small Untranslated; Streptococcus mutans; Virulence; Female; Rats
PubMed: 38620039
DOI: 10.1371/journal.ppat.1012147 -
Microbial Drug Resistance (Larchmont,... Jun 2024Integrative and conjugative elements (ICEs) are important vectors of lateral gene transfer and contribute to the evolution of bacterial pathogens. However, studies on...
Integrative and conjugative elements (ICEs) are important vectors of lateral gene transfer and contribute to the evolution of bacterial pathogens. However, studies on the transfer among species and the physiological consequences of ICEs are rare. The objective of this study was to investigate the cross-species transferability of newly identified (B)-carried ICE in 95 and its physiological consequences after transfer. The (B)-carried ICE, characterized by a triple serine integrase module, integrated into genes, thus designated ICE95_. Analysis of ICE95_ revealed 32 additional ICE95-like ICEs in the available NCBI genome ( = 24) and sequence of clinical isolates ( = 8). Polymerase chain reaction (PCR) was used to evaluate the 467 clinical isolates, of which 84 were positive for core genes (integrase, relaxase, and T4SS genes) of ICE95_. Cross-species transfer experiments demonstrated that ICE95_ could transfer from to different streptococcal and enterococcal recipients. Growth and competitive culture assays showed acquisition of ICE95_ incurred no fitness cost. Our work discovered a group of ICEs in Streptococci and Enterococci. For the first time, we demonstrated the broad cross-species transferability to different species or genera of ICEs with no fitness cost that enables commensal to deliver antimicrobial resistance genes to other streptococci and enterococci.
Topics: Streptococcus anginosus; Anti-Bacterial Agents; Gene Transfer, Horizontal; Enterococcus; Conjugation, Genetic; Streptococcus; Microbial Sensitivity Tests; Humans; Bacterial Proteins; Drug Resistance, Bacterial
PubMed: 38608246
DOI: 10.1089/mdr.2023.0342 -
Journal of Dentistry Jun 2024The objective of this study was to synthesize arginine loaded mesoporous silica nanoparticles (Arg@MSNs), develop a novel orthodontic adhesive using Arg@MSNs as...
OBJECTIVES
The objective of this study was to synthesize arginine loaded mesoporous silica nanoparticles (Arg@MSNs), develop a novel orthodontic adhesive using Arg@MSNs as modifiers, and investigate the adhesive performance, antibacterial activity, and biocompatibility.
METHODS
Arg@MSNs were synthesized by immobilizing arginine into MSNs and characterized using transmission electron microscope (TEM), dynamic light scattering (DLS), and Fourier Transform Infrared Spectrometer (FT-IR). Arg@MSNs were incorporated into Transbond XT adhesive with different mass fraction to form functional adhesives. The degree of conversion (DC), arginine release behavior, adhesive performance, antibacterial activity against Streptococcus mutans biofilm, and cytotoxicity were comprehensively evaluated.
RESULTS
TEM, DLS, and FT-IR characterizations confirmed the successful preparation of Arg@MSNs. The incorporation of Arg@MSNs did not significantly affect DC and exhibited clinically acceptable bonding strength. Compared to the commercial control, the Arg@MSNs modified adhesives greatly suppressed the metabolic activity and polysaccharide production while increased the biofilm pH values. The cell counting kit (CCK)-8 test indicated no cytotoxicity.
CONCLUSIONS
The novel orthodontic adhesive containing Arg@MSNs exhibited significantly enhanced antibacterial activities and inhibitory effects on acid production compared to the commercial adhesive without compromising their bonding strength or biocompatibility.
CLINICAL SIGNIFICANCE
The novel orthodontic adhesive containing Arg@MSNs exhibits potential clinical benefits in preventing demineralization of enamel surfaces around or beneath orthodontic brackets due to its enhanced antibacterial activities and acid-producing inhibitory effects.
Topics: Arginine; Silicon Dioxide; Nanoparticles; Streptococcus mutans; Biofilms; Anti-Bacterial Agents; Spectroscopy, Fourier Transform Infrared; Resin Cements; Humans; Dental Cements; Porosity; Materials Testing; Microscopy, Electron, Transmission; Dental Bonding; Orthodontic Brackets; Hydrogen-Ion Concentration; Biocompatible Materials
PubMed: 38599563
DOI: 10.1016/j.jdent.2024.104992 -
Bioorganic & Medicinal Chemistry Letters Jun 2024A new monoterpenoid, neoroseoside (1), along with two previously reported compounds, 2″-O-α-l-rhamnosyl-6-C-fucosylluteolin (2) and farobin A (3) were isolated from...
A new monoterpenoid, neoroseoside (1), along with two previously reported compounds, 2″-O-α-l-rhamnosyl-6-C-fucosylluteolin (2) and farobin A (3) were isolated from the Zea mays. The structure of compound 1 was determined through the analysis spectroscopic data, including mass spectrometry (MS), infrared (IR) spectroscopy, and nuclear magnetic resonance (NMR) data. The absolute configurations of 1 were deduced from the comparing the values of optical rotations and from the interpretation of electronic circular dichroism (ECD) spectra. Compounds 2 and 3 displayed moderate antibacterial activity against Streptococcus mutans ATCC 25175 (inhibition rates 24 % and 28 %, respectively) and Streptococcus sobrinus ATCC 33478 (inhibition rate of 26 %), at a concentration of 100 μg/mL, whereas compound 1 did not have any significant antibacterial activities. The compounds 1-3 also showed anti-inflammatory activity on cytokine IL-6 and TNF-α.
Topics: Zea mays; Anti-Bacterial Agents; Microbial Sensitivity Tests; Monoterpenes; Anti-Inflammatory Agents; Structure-Activity Relationship; Molecular Structure; Streptococcus mutans; Interleukin-6; Drug Discovery; Tumor Necrosis Factor-alpha; Dose-Response Relationship, Drug; Streptococcus
PubMed: 38599297
DOI: 10.1016/j.bmcl.2024.129737 -
ACS Applied Bio Materials May 2024Bacterial biofilms play a central role in the development and progression of periodontitis, a chronic inflammatory condition that affects the oral cavity. One solution...
Bacterial biofilms play a central role in the development and progression of periodontitis, a chronic inflammatory condition that affects the oral cavity. One solution to current treatment constraints is using nitric oxide (NO)─with inherent antimicrobial properties. In this study, an antimicrobial coating is developed from the NO donor -nitroso--acetylpenicillamine (SNAP) embedded within polyethylene glycol (PEG) to prevent periodontitis. The SNAP-PEG coating design enabled a controlled NO release, achieving tunable NO levels for more than 24 h. Testing the SNAP-PEG composite on dental floss showed its effectiveness as a uniform and bioactive coating. The coating exhibited antibacterial properties against and , with inhibition zones measuring up to 7.50 ± 0.28 and 14.80 ± 0.46 mm, respectively. Furthermore, SNAP-PEG coating materials were found to be stable when stored at room temperature, with 93.65% of SNAP remaining after 28 d. The coatings were biocompatible against HGF and hFOB 1.19 cells through a 24 h controlled release study. This study presents a facile method to utilize controlled NO release with dental antimicrobial coatings comprising SNAP-PEG. This coating can be easily applied to various substrates, providing a user-friendly approach for targeted self-care in managing gingival infections associated with periodontitis.
Topics: Streptococcus mutans; Nitric Oxide; Escherichia coli; Humans; Anti-Bacterial Agents; Materials Testing; Coated Materials, Biocompatible; Polyethylene Glycols; Microbial Sensitivity Tests; Particle Size; Biofilms; S-Nitroso-N-Acetylpenicillamine; Surface Properties; Periodontitis; Gingiva
PubMed: 38593411
DOI: 10.1021/acsabm.4c00051