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Archives of Oral Biology Aug 2024There have been reports on the effects of epigallocatechin gallate (EGCG) against Streptococcus mutans viability and acidogenesis. However, the effects of EGCG on the...
INTRODUCTION
There have been reports on the effects of epigallocatechin gallate (EGCG) against Streptococcus mutans viability and acidogenesis. However, the effects of EGCG on the virulence of S. mutans biofilm development have yet to be fully investigated using validated cariogenic biofilm models.
OBJECTIVE
Thus, this study aimed to evaluate the effects of EGCG on S. mutans biofilm virulence using a validated cariogenic model and clinically relevant treatment regimens, twice a day for 1.5 min.
METHODS
Effects of EGCG on bacterial viability, polyssacharide synthesis and biofilm acidogenesis were evaluated. The morphology and 3D structure of the biofilms were evaluated by scanning electron (SEM) and confocal laser scanning microscopy, respectively.
RESULTS
No significant change in S. mutans viability or culture medium pH were observed when comparing EGCG-treated and NaCl-treated biofilms. EGCG significantly reduced the accumulation of soluble and insoluble polysaccharides, resulting in the formation of a biofilm with interspaced exopolysaccharide-microcolony complexes unevenly distributed on enamel. The SEM images of the biofilm treated with EGCG depict multilayers of cells arranged in short chains of microorganisms adhered to an unstructured matrix, which is not continuous and does not enmesh or protect the microorganisms entirely. Importantly, confocal images demonstrated that treatment with EGCG affected the 3D structure and organization of S. mutans biofilm, which presented a biofilm matrix more confined to the location of the microcolonies.
CONCLUSION
In conclusion, EGCG lowered the virulence of S. mutans matrix-rich biofilm by reducing the synthesis of biofilm matrix components, altering the biofilm matrix structure, organization, and distribution.
Topics: Biofilms; Streptococcus mutans; Catechin; Virulence; Microscopy, Confocal; Microscopy, Electron, Scanning; Dental Caries; Hydrogen-Ion Concentration; Microbial Viability; Polysaccharides, Bacterial; Dental Enamel
PubMed: 38749386
DOI: 10.1016/j.archoralbio.2024.105990 -
ACS Nano May 2024Dental caries is a widespread oral disease that poses a significant medical challenge. Traditional caries prevention methods, primarily the application of fluoride,...
Dental caries is a widespread oral disease that poses a significant medical challenge. Traditional caries prevention methods, primarily the application of fluoride, often fall short in effectively destroying biofilms and preventing enamel demineralization, thereby providing limited efficacy in halting the progression of caries over time. To address this issue, we have developed a green and cost-effective synergistic strategy for the prevention of dental caries. By combining natural sodium phytate and chitosan, we have created chitosan-sodium phytate nanoparticles that offer both the antimicrobial properties of chitosan and the enamel demineralization-inhibiting capabilities of sodium phytate. In an biofilm model of human teeth, we found that these nanoparticles effectively prevent biofilm buildup and acid damage to the mineralized tissue. Additionally, topical treatment of dental caries in rodent models has shown that these nanoparticles effectively suppress disease progression without negatively impacting oral microbiota diversity or causing harm to the gingival-mucosal tissues, unlike traditional prevention methods.
Topics: Dental Caries; Chitosan; Humans; Nanoparticles; Phytic Acid; Animals; Biofilms; Streptococcus mutans; Anti-Bacterial Agents; Mice
PubMed: 38747549
DOI: 10.1021/acsnano.3c11806 -
Portuguese Journal of Cardiac Thoracic... May 2024Purulent pericarditis secondary to esophago-pericardial fistula is a serious complication that has been previously reported in patients with esophageal cancer treated...
Purulent pericarditis secondary to esophago-pericardial fistula is a serious complication that has been previously reported in patients with esophageal cancer treated with radio/chemotherapy and esophageal stenting. However, the presence of esophago-pericardial fistula as the first manifestation of advanced carcinoma of the esophagus is exceedingly infrequent. We report the case of a 61-year-old male who presented with sepsis, cardiac tamponade and septic shock who was found to have an esophago-pericardial fistula secondary to squamous carcinoma of the esophagus. Emergency pericardiocentesis was performed with subsequent hemodynamic improvement. The drained pericardial fluid was purulent in nature and cultures were positive for Streptococcus anginosus. A CT scan followed by upper gastrointestinal endoscopy with tissue biopsy confirmed the diagnosis of squamous cell carcinoma of the esophagus. A self-expanding covered stent was endoscopically placed to exclude the fistula and restore the esophageal lumen. In this report, we discuss some aspects related to the diagnosis and management of this serious clinical entity.
Topics: Humans; Male; Middle Aged; Esophageal Neoplasms; Pericarditis; Carcinoma, Squamous Cell; Esophageal Fistula; Streptococcal Infections; Streptococcus anginosus; Pericardiocentesis; Stents; Tomography, X-Ray Computed; Cardiac Tamponade
PubMed: 38743514
DOI: 10.48729/pjctvs.423 -
Scientific Reports May 2024The aim of this study was to evaluate the antimicrobial efficacy of an air gas soft jet CAP for its potential use in removing oral biofilms, given that plasma-based...
The aim of this study was to evaluate the antimicrobial efficacy of an air gas soft jet CAP for its potential use in removing oral biofilms, given that plasma-based technologies have emerged as promising methods in periodontology. Two types of biofilms were developed, one by Streptococcus mutans UA 159 bacterial strain and the other by a complex mixture of saliva microorganisms isolated from a patient with periodontitis. This latter biofilm was characterized via Next Generation Sequencing to determine the main bacterial phyla. The CAP source was applied at a distance of 6 mm for different time points. A statistically significant reduction of both CFU count and XTT was already detected after 60 s of CAP treatment. CLSM analysis supported CAP effectiveness in killing the microorganisms inside the biofilm and in reducing the thickness of the biofilm matrix. Cytotoxicity tests demonstrated the possible use of CAP without important side effects towards human gingival fibroblasts cell line. The current study showed that CAP treatment was able to significantly reduce preformed biofilms developed by both S. mutans and microorganisms isolated by a saliva sample. Further studies should be conducted on biofilms developed by additional saliva donors to support the potential of this innovative strategy to counteract oral pathogens responsible for periodontal diseases.
Topics: Biofilms; Humans; Plasma Gases; Streptococcus mutans; Saliva; Fibroblasts; Periodontitis; Cell Line; Mouth
PubMed: 38740792
DOI: 10.1038/s41598-024-61438-z -
World Journal of Microbiology &... May 2024Cariogenic biofilms have a matrix rich in exopolysaccharides (EPS), mutans and dextrans, that contribute to caries development. Although several physical and chemical...
Cariogenic biofilms have a matrix rich in exopolysaccharides (EPS), mutans and dextrans, that contribute to caries development. Although several physical and chemical treatments can be employed to remove oral biofilms, those are only partly efficient and use of biofilm-degrading enzymes represents an exciting opportunity to improve the performance of oral hygiene products. In the present study, a member of a glycosyl hydrolase family 66 from Flavobacterium johnsoniae (FjGH66) was heterologously expressed and biochemically characterized. The recombinant FjGH66 showed a hydrolytic activity against an early EPS-containing S. mutans biofilm, and, when associated with a α-(1,3)-glucosyl hydrolase (mutanase) from GH87 family, displayed outstanding performance, removing more than 80% of the plate-adhered biofilm. The mixture containing FjGH66 and Prevotella melaninogenica GH87 α-1,3-mutanase was added to a commercial mouthwash liquid to synergistically remove the biofilm. Dental floss and polyethylene disks coated with biofilm-degrading enzymes also degraded plate-adhered biofilm with a high efficiency. The results presented in this study might be valuable for future development of novel oral hygiene products.
Topics: Biofilms; Dextranase; Flavobacterium; Streptococcus mutans; Glycoside Hydrolases; Recombinant Proteins; Bacterial Proteins; Hydrolysis; Biotechnology
PubMed: 38736020
DOI: 10.1007/s11274-024-04014-x -
Southern African Journal of Infectious... 2024Viridans Group Streptococci (VGS) are often considered organisms of low virulence; however, infection can result in clinically significant sepsis and life-threatening...
BACKGROUND
Viridans Group Streptococci (VGS) are often considered organisms of low virulence; however, infection can result in clinically significant sepsis and life-threatening complications in paediatric patients.
OBJECTIVES
This study aimed to describe the spectrum of clinical presentation of VGS bacteraemia in paediatric patients, to analyse risk factors, and to describe the antibiotics resistance patterns of VGS.
METHOD
Cultures of VGS in paediatric patients admitted to Chris Hani Baragwanath Academic Hospital in 2019 were identified through National Health Laboratory Service. Data were extracted from archived clinical records and analysed. Sepsis scores were calculated at the time of bacteraemia.
RESULTS
A total of 133 cultures were identified; 64 (48.1%) polymicrobial cultures and no records 4 (0.03%) were excluded; 65 (48.9%) were analysed. The median age was 1.5 months (range 0.03 to 168, interquartile range [IQR]: 0.3-13.25), 27/65 (42%) were neonates. The median duration of hospitalisation was 7 days (IQR: 3-21). The commonest diagnoses were neonatal sepsis 30.8% ( = 20) and pneumonia 28% ( = 18). The systemic inflammatory response syndrome (SIRS) score was ≥ 2 in 57% (16/28) patients; paediatric sequential organ failure assessment (pSOFA) score was > 2 in 10/24 (42%). Fifty-seven (88%) patients were discharged; three (5%) required ICU admission and 8/65 (12.3%) died. Malnutrition was present in 50% of patients who died. Cephalosporins and penicillin had sensitivity of 89% and 55%, respectively.
CONCLUSION
Viridans Group Streptococci bacteraemia was common in neonates, and pneumonia was a common presentation in this cohort. The VGS bacteraemia was associated with morbidity and deaths in this cohort.
CONTRIBUTION
The VGS should be considered a significant organism when cultured from sterile sites and routine antibiotic susceptibility testing should be performed. Prospective studies are recommended.
PubMed: 38726020
DOI: 10.4102/sajid.v39i1.563 -
Archives of Oral Biology Aug 2024To evaluate the adhesion of mono and duospecies biofilm on a commercially available dental implant surface coated with hydroxyapatite nanoparticles (nanoHA).
AIM
To evaluate the adhesion of mono and duospecies biofilm on a commercially available dental implant surface coated with hydroxyapatite nanoparticles (nanoHA).
MATERIAL AND METHODS
Titanium discs were divided into two groups: double acid-etched (AE) and AE coated with nanoHA (NanoHA). Surface characteristics evaluated were morphology, topography, and wettability. Mono and duospecies biofilms of Streptococcus sanguinis (S. sanguinis) and Candida albicans (C. albicans) were formed. Discs were exposed to fetal bovine serum (FBS) to form the pellicle. Biofilm was growth in RPMI1640 medium with 10% FBS and 10% BHI medium for 6 h. Microbial viability was evaluated using colony-forming unit and metabolic activity by a colorimetric assay of the tetrazolium salt XTT. Biofilm architecture and organization were evaluated by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM).
RESULTS
AE surface had more pores, while NanoHA had even nanoHA crystals distribution. Roughness was similar (AE: 0.59 ± 0.07 µm, NanoHA: 0.69 ± 0.18 µm), but wettability was different (AE: Θw= 81.79 ± 8.55°, NanoHA: Θw= 53.26 ± 11.86°; P = 0.01). NanoHA had lower S. sanguinis viability in monospecies biofilm (P = 0.007). Metabolic activity was similar among all biofilms. In SEM both surfaces on C. albicans biofilm show a similar distribution of hyphae in mono and duospecies biofilms. AE surface has more S. sanguinis than the NanoHA surface in the duospecies biofilm. CLSM showed a large proportion of live cells in all groups.
CONCLUSIONS
The nanoHA surface reduced the adhesion of S. sanguinis biofilm but did not alter the adhesion of C. albicans or the biofilm formed by both species.
Topics: Titanium; Candida albicans; Biofilms; Durapatite; Streptococcus sanguis; Nanoparticles; Surface Properties; Microscopy, Electron, Scanning; Dental Implants; Microscopy, Confocal; In Vitro Techniques; Bacterial Adhesion; Wettability; Coated Materials, Biocompatible; Acid Etching, Dental; Microbial Viability
PubMed: 38723421
DOI: 10.1016/j.archoralbio.2024.105986 -
Dental Materials : Official Publication... Jun 2024Bisphenol A glycidyl methacrylate (Bis-GMA) is of great importance for dental materials as the preferred monomer. However, the presence of bisphenol-A (BPA) core in...
OBJECTIVE
Bisphenol A glycidyl methacrylate (Bis-GMA) is of great importance for dental materials as the preferred monomer. However, the presence of bisphenol-A (BPA) core in Bis-GMA structure causes potential concerns since it is associated with endocrine diseases, developmental abnormalities, and cancer lesions. Therefore, it is desirable to develop an alternative replacement for Bis-GMA and explore the intrinsic relationship between monomer structure and resin properties.
METHODS
Here, the betulin maleic diester derivative (MABet) was synthesized by a facile esterification reaction using plant-derived betulin and maleic anhydride as raw materials. Its chemical structure was confirmed by H and C NMR spectra, FT-IR spectra, and HR-MS, respectively. The as-synthesized MABet was then used as polymerizable comonomer to partially or completely substitute Bis-GMA in a 50:50 Bis-GMA: TEGDMA resin (5B5T) to formulate dental restorative resins. These were then determined for the viscosity behavior, light transmittance, real-time degree of conversion, residual monomers, mechanical performance, cytotoxicity, and antibacterial activity against Streptococcus mutans (S. mutans) in detail.
RESULTS
Among all experimental resins, increasing the MABet concentration to 50 wt% made the resultant 5MABet5T resin have a maximum in viscosity and appear dark yellowish after polymerization. In contrast, the 1MABet4B5T resin with 10 wt% MABet possessed comparable shear viscosity and polymerization conversion (46.6 ± 1.0% in 60 s), higher flexural and compressive strength (89.7 ± 7.8 MPa; 345.5 ± 14.4 MPa) to those of the 5B5T control (48.5 ± 0.6%; 65.7 ± 6.7 MPa; 223.8 ± 57.1 MPa). This optimal resin also had significantly lower S. mutans colony counts (0.35 ×10 CFU/mL) than 5B5T (7.6 ×10 CFU/mL) without affecting cytocompatibility.
SIGNIFICANCE
Introducing plant-derived polymerizable MABet monomer into dental restorative resins is an effective strategy for producing antibacterial dental materials with superior physicochemical property.
Topics: Anti-Bacterial Agents; Triterpenes; Materials Testing; Streptococcus mutans; Bisphenol A-Glycidyl Methacrylate; Viscosity; Dental Materials; Polymerization; Polymethacrylic Acids; Composite Resins; Polyethylene Glycols; Spectroscopy, Fourier Transform Infrared; Betulinic Acid
PubMed: 38719709
DOI: 10.1016/j.dental.2024.04.007 -
Archives of Oral Biology Aug 2024To evaluate the effect of the association of potassium iodide to antimicrobial photodynamic therapy on human carious dentin produced with a microcosm biofilm model.
OBJECTIVE
To evaluate the effect of the association of potassium iodide to antimicrobial photodynamic therapy on human carious dentin produced with a microcosm biofilm model.
METHODS
A microcosm biofilm model was used to generate a caries lesion on human dentin. Pooled human saliva diluted with glycerol was used as an inoculum on specimens immersed on McBain artificial saliva enriched with 1 % sucrose (24 h at 37 °C in 5 % CO). After refreshing culture media for 7 days, the dentin specimens were divided in 5 groups (3 specimens per group, in triplicate; n = 9): C (NaCl 0.9 %), CX (2 % chlorhexidine), PKI (0.01 % methylene blue photosensitizer+50 mM KI), L (laser at 15 J, 180 s, 22.7 J/cm), and PKIL (methylene blue + KI + Laser). After the treatments, dentin was collected, and a 10-fold serial dilution was performed. The number of total microorganisms, total lactobacilli, total streptococci, and Streptococcus mutans was analyzed by microbial counts (CFU/mL). After normality and homoscedasticity analysis, the Welch's ANOVA and Dunnett's tests were used for CFU. All tests used a 5 % significance level.
RESULTS
CX and PKIL groups showed significant bacterial decontamination of dentin, compared to group C (p < 0.05) reaching reductions up to 3.8 log for CX for all microorganisms' groups and PKIL showed 0.93, 1.30, 1.45, and 1.22 log for total microorganisms, total lactobacilli, total streptococci, and S. mutans, respectively.
CONCLUSION
aPDT mediated by the association of KI and methylene blue with red laser reduced the viability of microorganisms from carious dentin and could be a promising option for cavity decontamination.
Topics: Humans; Methylene Blue; Photochemotherapy; Dental Caries; Dentin; Potassium Iodide; Biofilms; Streptococcus mutans; Photosensitizing Agents; Saliva; Lactobacillus; Streptococcus; Chlorhexidine; In Vitro Techniques; Colony Count, Microbial; Saliva, Artificial; Lasers
PubMed: 38718465
DOI: 10.1016/j.archoralbio.2024.105978 -
PloS One 2024Bacterial pathogens have remained a major public health concern for several decades. This study investigated the antibacterial activities of Miang extracts (at...
Bacterial pathogens have remained a major public health concern for several decades. This study investigated the antibacterial activities of Miang extracts (at non-neutral and neutral pH) against Bacillus cereus TISTR 747, Escherichia coli ATCC 22595, Salmonella enterica serovar Typhimurium TISTR 292 and Streptococcus mutans DMST 18777. The potential of Polyvinylpolypyrrolidone (PVPP)-precipitated tannin-free Miang extracts in growth-inhibition of the cariogenic Streptococcus mutans DMST 18777 and its biofilms was also evaluated. The tannin-rich fermented extracts had the best bacterial growth inhibition against S. mutans DMST 18777 with an MIC of 0.29 and 0.72 mg/mL for nonfilamentous fungi (NFP) Miang and filamentous-fungi-processed (FFP) Miang respectively. This observed anti-streptococcal activity still remained after PVPP-mediated precipitation of bioactive tannins especially, in NFP and FFP Miang. Characterization of the PVPP-treated extracts using High performance liquid chromatography quadrupole-time of flight-mass spectrometry (HPLC-QToF-MS) analysis, also offered an insight into probable compound classes responsible for the activities. In addition, Crystal violet-staining also showed better IC50 values for NFP Miang (4.30 ± 0.66 mg/mL) and FFP Miang (12.73 ± 0.11 mg/mL) against S. mutans DMST 18777 biofilms in vitro. Homology modeling and molecular docking analysis using HPLC-MS identified ligands in tannin-free Miang supernatants, was performed against modelled S. mutans DMST 18777 sortase A enzyme. The in silico analysis suggested that the inhibition by NFP and FFP Miang might be attributed to the presence of ellagic acid, flavonoid aglycones, and glycosides. Thus, these Miang extracts could be optimized and explored as natural active pharmaceutical ingredients (NAPIs) for applications in oral hygienic products.
Topics: Streptococcus mutans; Anti-Bacterial Agents; Tannins; Microbial Sensitivity Tests; Biofilms; Plant Extracts; Molecular Docking Simulation; Bacterial Proteins
PubMed: 38718045
DOI: 10.1371/journal.pone.0302717