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Dental and Medical Problems 2024Sleep quality has a significant impact on a child's health and is linked to oral and systemic diseases. It affects the circadian rhythm, which plays a crucial role in... (Comparative Study)
Comparative Study
BACKGROUND
Sleep quality has a significant impact on a child's health and is linked to oral and systemic diseases. It affects the circadian rhythm, which plays a crucial role in regulating the balance of the endocrine and hormonal systems. Current research has focused on exploring its role in the development of caries, which is influenced by inherent oral factors such as the composition of the oral microbiome and pH levels.
OBJECTIVES
This study aimed to investigate the relationship between bacterial population, pH, and buffering properties of saliva and sleep patterns in 8- to 12-year-old children.
MATERIAL AND METHODS
This cross-sectional study was conducted on 85 elementary school children aged 8-12 years. After obtaining written consent, non-stimulating saliva samples were collected using the spitting method. The participants' sleep pattern information was obtained with the use of the Persian version of the Children's Sleep Habits Questionnaire (CSHQ). Based on the results of the CSHQ, the participants were divided into 2 groups: those with appropriate sleep patterns; and those with inappropriate sleep patterns. The study compared the bacterial population of Streptococcus mutans, Lactobacillus spp. and Candida albicans, as well as the buffering capacity and pH of the saliva between the 2 groups. The statistical analysis employed the χ2 test, the independent samples t-test and Spearman's correlation.
RESULTS
The group with inappropriate sleep patterns had significantly lower pH and buffering capacity (p < 0.001) and significantly higher colony counts of Lactobacillus and S. mutans (p < 0.001 and p = 0.012, respectively). There was no association between C. albicans and sleep patterns (p = 0.121).
CONCLUSIONS
Inappropriate sleep patterns increase the population of caries-causing bacteria and reduce salivary pH and buffering capacity. This can be a significant factor in the development of dental caries in children aged 8-12 years.
Topics: Humans; Child; Saliva; Hydrogen-Ion Concentration; Cross-Sectional Studies; Female; Male; Dental Caries; Streptococcus mutans; Candida albicans; Buffers; Lactobacillus; Sleep
PubMed: 38668709
DOI: 10.17219/dmp/167411 -
Journal of Applied Oral Science :... 2024This study evaluated the surface roughness, wettability and adhesion of multispecies biofilms (Candida albicans, Staphylococcus aureus and Streptococcus mutans) on...
OBJECTIVE
This study evaluated the surface roughness, wettability and adhesion of multispecies biofilms (Candida albicans, Staphylococcus aureus and Streptococcus mutans) on 3D-printed resins for complete denture bases and teeth compared to conventional resins (heat-polymerized acrylic resin; artificial pre-fabricated teeth).
METHODOLOGY
Circular specimens (n=39; 6.0 mm Ø × 2.0 mm) of each group were subjected to roughness (n=30), wettability (n=30) and biofilm adhesion (n=9) tests. Three roughness measurements were taken by laser confocal microscopy and a mean value was calculated. Wettability was evaluated by the contact angle of sessile drop method, considering the mean of the three evaluations per specimen. In parallel, microorganism adhesion to resin surfaces was evaluated using a multispecies biofilm model. Microbial load was evaluated by determining the number of Colony Forming Units (CFU/mL) and by scanning electron microscopy (SEM). Data were subjected to the Wald test in a generalized linear model with multiple comparisons and Bonferroni adjustment, as well as two-way ANOVA (α=5%).
RESULTS
The roughness of the conventional base resin (0.01±0.04) was lower than that of the conventional tooth (0.14±0.04) (p=0.023) and 3D-printed base (0.18±0.08) (p<0.001). For wettability, conventional resin (84.20±5.57) showed a higher contact angle than the 3D-printed resin (60.58±6.18) (p<0.001). Higher microbial loads of S. mutans (p=0.023) and S. aureus (p=0.010) were observed on the surface of the conventional resin (S. mutans: 5.48±1.55; S. aureus: 7.01±0.57) compared to the 3D-printed resin (S. mutans: 4.11±1.96; S. aureus: 6.42±0.78). The adhesion of C. albicans was not affected by surface characteristics. The conventional base resin showed less roughness than the conventional dental resin and the printed base resin.
CONCLUSION
The 3D-printed resins for base and tooth showed less hydrophobicity and less adhesion of S. mutans and S. aureus than conventional resins.
Topics: Biofilms; Surface Properties; Printing, Three-Dimensional; Streptococcus mutans; Staphylococcus aureus; Candida albicans; Wettability; Microscopy, Electron, Scanning; Materials Testing; Denture Bases; Microscopy, Confocal; Acrylic Resins; Bacterial Adhesion; Analysis of Variance; Reproducibility of Results; Denture, Complete; Reference Values; Colony Count, Microbial; Linear Models
PubMed: 38656049
DOI: 10.1590/1678-7757-2023-0326 -
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 -
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 -
Microbiology Spectrum May 2024The tenacious biofilms formed by are resistant to conventional antibiotics and current treatments. There is a growing need for novel therapeutics that selectively...
The tenacious biofilms formed by are resistant to conventional antibiotics and current treatments. There is a growing need for novel therapeutics that selectively inhibit biofilms while preserving the normal oral microenvironment. Previous studies have shown that increased levels of cyclic di-AMP, an important secondary messenger synthesized by diadenylate cyclase (DAC), favored biofilm formation in . Thus, targeting DAC is a novel strategy to inhibit biofilms. We screened a small NCI library of natural products using a fluorescence detection assay. (+)-Brazilin, a tetracyclic homoisoflavanoid found in the heartwood of , was identified as one of the 11 "hits," with the greatest reduction (>99%) in fluorescence at 100 µM. The DAC inhibitory profiles of the 11 "hits" established by a quantitative high-performance liquid chromatography assay revealed that (+)-brazilin had the most enzymatic inhibitory activity (87% at 100 µM) and was further studied to determine its half maximal inhibitory concentration (IC = 25.1 ± 0.98 µM). (+)-Brazilin non-competitively inhibits DAC's enzymatic activity ( = 140.0 ± 27.13 µM), as determined by a steady-state Michaelis-Menten kinetics assay. In addition, (+)-brazilin's binding profile with DAC ( = 11.87 µM) was illustrated by a tyrosine intrinsic fluorescence quenching assay. Furthermore, at low micromolar concentrations, (+)-brazilin selectively inhibited the biofilm of (IC = 21.0 ± 0.60 µM) and other oral bacteria. biofilms were inhibited by a factor of 10 in colony-forming units when treated with 50 µM (+)-brazilin. In addition, a significant dose-dependent reduction in extracellular DNA and glucan levels was evident by fluorescence microscopy imaging of biofilms exposed to different concentrations of (+)-brazilin. Furthermore, colonization of on a representative model of enamel using suspended hydroxyapatite discs showed a >90% reduction with 50 µM (+)-brazilin. In summary, we have identified a drug-like natural product inhibitor of biofilm that not only binds to DAC but can also inhibit the function of DAC. (+)-Brazilin could be a good candidate for further development as a potent therapeutic for the prevention and treatment of dental caries.IMPORTANCEThis study represents a significant advancement in our understanding of potential therapeutic options for combating cariogenic biofilms produced by . The research delves into the use of (+)-brazilin, a natural product, as a potent inhibitor of ' diadenylate cyclase (DAC), an enzyme crucial in the formation of biofilms. The study establishes (+)-brazilin as a non-competitive inhibitor of DAC while providing initial insights into its binding mechanism. What makes this finding even more promising is that (+)-brazilin does not limit its inhibitory effects to alone. Instead, it demonstrates efficacy in hindering biofilms in other oral bacteria as well. The broader spectrum of anti-biofilm activity suggests that (+)-brazilin could potentially serve as a versatile tool in a natural product-based treatment for combating a range of conditions caused by resilient biofilms.
Topics: Biofilms; Streptococcus mutans; Isoflavones; Anti-Bacterial Agents; Biological Products; Microbial Sensitivity Tests; Phosphorus-Oxygen Lyases; Bacterial Proteins; Humans
PubMed: 38591917
DOI: 10.1128/spectrum.02418-23 -
JPMA. the Journal of the Pakistan... Mar 2024
Topics: Humans; Chlorhexidine; Streptococcus mutans; Oral Health; Dental Plaque; Saliva; Probiotics; Dental Caries; Colony Count, Microbial
PubMed: 38591271
DOI: 10.47391/JPMA.24-15 -
BMC Neurology Apr 2024Streptococcus intermedius is a member of the S. anginosus group and is part of the normal oral microbiota. It can cause pyogenic infections in various organs, primarily...
BACKGROUND
Streptococcus intermedius is a member of the S. anginosus group and is part of the normal oral microbiota. It can cause pyogenic infections in various organs, primarily in the head and neck area, including brain abscesses and meningitis. However, ventriculitis due to periodontitis has not been reported previously.
CASE PRESENTATION
A 64-year-old male was admitted to the hospital with a headache, fever and later imbalance, blurred vision, and general slowness. Neurological examination revealed nuchal rigidity and general clumsiness. Meningitis was suspected, and the patient was treated with dexamethasone, ceftriaxone and acyclovir. A brain computer tomography (CT) scan was normal, and cerebrospinal fluid (CSF) Gram staining and bacterial cultures remained negative, so the antibacterial treatment was discontinued. Nine days after admission, the patient's condition deteriorated. The antibacterial treatment was restarted, and a brain magnetic resonance imaging revealed ventriculitis. A subsequent CT scan showed hydrocephalus, so a ventriculostomy was performed. In CSF Gram staining, chains of gram-positive cocci were observed. Bacterial cultures remained negative, but a bacterial PCR detected Streptococcus intermedius. An orthopantomography revealed advanced periodontal destruction in several teeth and periapical abscesses, which were subsequently operated on. The patient was discharged in good condition after one month.
CONCLUSIONS
Poor dental health can lead to life-threatening infections in the central nervous system, even in a completely healthy individual. Primary bacterial ventriculitis is a diagnostic challenge, which may result in delayed treatment and increased mortality.
Topics: Male; Humans; Middle Aged; Streptococcus intermedius; Cerebral Ventriculitis; Anti-Bacterial Agents; Meningitis; Central Nervous System Bacterial Infections; Periodontitis
PubMed: 38580923
DOI: 10.1186/s12883-024-03604-4 -
Journal of Global Antimicrobial... Jun 2024Eravacycline, a new tetracycline derivative, exhibits broad-spectrum antimicrobial susceptibility. This study aimed to comprehensively investigate in vitro activities of... (Comparative Study)
Comparative Study
OBJECTIVES
Eravacycline, a new tetracycline derivative, exhibits broad-spectrum antimicrobial susceptibility. This study aimed to comprehensively investigate in vitro activities of eravacycline, tigecycline, and ertapenem against various Gram-positive, Gram-negative, and anaerobic bacteria.
METHODS
Minimum inhibitory concentrations (MICs) were determined using the broth microdilution method. The following bacterial species were collected: vancomycin-sensitive (VS) Enterococci species, vancomycin-resistant Enterococci species (VRE), Staphylococcus aureus, Streptococcus anginosus, Bacteroides species, Clostridioides difficile, Clostridium innocuum, Clostridium perfringens, Parabacteroides distasonis, and Stenotrophomonas maltophilia.
RESULTS
We found that eravacycline exhibited superior in vitro activity compared to tigecycline and ertapenem. Notably, it exhibited the lowest MIC for several bacterial species, including VS E. faecalis (0.12 µg/mL), VS E. faecium (0.12 µg/mL), and others. Besides, VRE was susceptible to eravacycline (MIC:0.12 µg/mL) and tigecycline (MIC:0.12 µg/mL), but was all resistant to ertapenem (MIC > 64 µg/mL). S. aureus was also susceptible to eravacycline (MIC:0.5 µg/mL) as well as tigecycline (MIC:1.0 µg/mL). Furthermore, S. anginosus showed higher susceptibility to eravacycline (MIC:2.0 µg/mL) and tigecycline (MIC:4.0 µg/mL), but lower to ertapenem (MIC:32.0 µg/mL). Eravacycline and tigecycline also demonstrated good susceptibility to anaerobes, including Bacteroides species (susceptibility rate: 100%), P. distasonis (100%), C. difficile (94.1‒100%), C. innocuum (94.1‒96.1%), and C. perfringens (88.9‒96.3%). For S. maltophilia, both tigecycline and eravacycline showed an MIC of 2 µg/mL. A moderate-to-strong correlation (rho = 0.608-0.804, P < 0.001) was noted between the MIC values of eravacycline and tigecycline against various bacterial species.
CONCLUSIONS
Our study highlights the potential of eravacycline as an effective treatment option for multidrug-resistant bacterial infections.
Topics: Microbial Sensitivity Tests; Tigecycline; Tetracyclines; Humans; Anti-Bacterial Agents; Bacteria, Anaerobic; Taiwan; Ertapenem; Staphylococcus aureus; Bacteria, Aerobic; Vancomycin-Resistant Enterococci; Streptococcus anginosus; Clostridioides difficile; Stenotrophomonas maltophilia; Vancomycin; Gram-Negative Bacteria; Gram-Positive Bacteria
PubMed: 38552878
DOI: 10.1016/j.jgar.2024.03.014 -
BMC Complementary Medicine and Therapies Mar 2024Natural products are one of the best candidates for controlling drug-resistant pathogens, the advantages of which include low production costs and low side effects. In...
BACKGROUND
Natural products are one of the best candidates for controlling drug-resistant pathogens, the advantages of which include low production costs and low side effects. In this study, as potential antimicrobials, the anti-bacterial and antibiofilm activities of several Iranian native medicinal plants were screened.
METHODS
The antibacterial/antifungal and anti-biofilm activities of 18 medicinal plants including Reseda lutea L., Nepeta sintenisii Bunge., Stachys turcomanica Trautv., Stachys lavandulifolia Vahl, Diarthron antoninae (Pobed.) Kit Tan., Ziziphora clinopodioides Lam., Euphorbia kopetdaghi Prokh, Euphorbia serpens Kunth., Hymenocrater calycinus Benth., Scutellaria pinnatifida A.Ham., Viola tricolor L., Hypericum helianthemoides (Spach) Boiss., Hypericum scabrum L., Convolvulus lineatus L., Scabiosa rotata M.Bieb Greuter & Burdet, Delphinium semibarbatum Bien. Ex Boiss., Glycyrrhiza triphylla Fisch. & C.A.Mey., and Ziziphus jujuba Mill., against two Gram-positive bacteria, Staphylococcus aureus, Bacillus cereus, as well as two Gram-negative bacteria, Pseudomonas aeruginosa, Escherichia coli; and Candida albicans as a fungal strain, were evaluated. The minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC) values of the extracts against tested microorganisms were reported and we investigated their effect on the biofilm inhibition of Pseudomonas aeruginosa PAO1, Staphylococcus epidermis, Staphylococcus aureus and Streptococcus mutans. In addition, the effect of the extracts on the eradication of the biofilms of these bacteria was evaluated.
RESULTS
In this study, H. scabrum was found to exhibit potentially significant activity against Gram-positive bacteria with the MIC range of 6.25-25 µg/mL. This extract also showed a significant effect on inhibiting the biofilm of S. aureus, S. mutans, and S. epidermidis and eradicating the biofilm of S. epidermidis DSMZ 3270. In addition, Hymenocrater calycinus root extract had moderate antibacterial activity against B. cereus with the MIC and MBC 62.5 µg/mL, respectively.
CONCLUSIONS
The results of this study showed that the root extracts of two plants, Hypericum scabrum and Hymenocrater calycinus, had antimicrobial and anti-biofilm effects. Based on the observed anti-biofilm effects, these two plants may be considered in future studies to find responsible antimicrobial compounds.
Topics: Plants, Medicinal; Iran; Staphylococcus aureus; Plant Extracts; Anti-Infective Agents; Anti-Bacterial Agents; Biofilms; Candida albicans; Pseudomonas aeruginosa; Streptococcus mutans
PubMed: 38549139
DOI: 10.1186/s12906-024-04437-x