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International Journal of Molecular... Oct 2023We conducted a meta-analysis and systematic review to investigate the efficacy of chitosan-containing chewing gums, and to test their inhibitory effects on . The... (Meta-Analysis)
Meta-Analysis Review
We conducted a meta-analysis and systematic review to investigate the efficacy of chitosan-containing chewing gums, and to test their inhibitory effects on . The systematic search was performed in three databases (Cochrane Library, EMBASE, and PubMed) and included English-language randomized-controlled trials to compare the efficacy of chitosan in reducing the number of . To assess the certainty of evidence, the GRADE tool was used. Mean differences were calculated with a 95% confidence interval for one outcome: bacterial counts in CFU/mL. The protocol of the study was registered on PROSPERO, registration number CRD42022365006. Articles were downloaded ( = 6758) from EMBASE ( = 2255), PubMed ( = 1516), and Cochrane ( = 2987). After the selection process, a total of four articles were included in the qualitative synthesis and three in the quantitative synthesis. Our results show that chitosan reduced the number of bacteria. The difference in mean quantity was -4.68 × 10. The interval of the random-effects model was [-2.15 × 10; 1.21 × 10] and the prediction interval was [1.03 × 10; 9.40 × 10]. The I2 value was 98% ( = 0.35), which indicates a high degree of heterogeneity. Chitosan has some antibacterial effects when used as a component of chewing gum, but further studies are needed. It can be a promising antimicrobial agent for prevention.
Topics: Humans; Streptococcus mutans; Saliva; Chitosan; Anti-Infective Agents; Anti-Bacterial Agents; Chewing Gum; Dental Caries
PubMed: 37894948
DOI: 10.3390/ijms242015270 -
Medicina (Kaunas, Lithuania) Oct 2023: The oral cavity is inhabited by pathogenic bacteria, whose growth can be inhibited by synthetic oral drugs, including antibiotics and other chemical compounds. Natural...
: The oral cavity is inhabited by pathogenic bacteria, whose growth can be inhibited by synthetic oral drugs, including antibiotics and other chemical compounds. Natural antimicrobial substances that elicit fewer negative side effects may serve as alternatives to synthetic agents for long-term use. Thus, the aim of this study was to evaluate the effects of edible mixed herbal extracts on the growth of oral pathogenic bacteria. : The yield of each herbal extract was as follows: 5% Briq (STB), 10.94% (MP), 5.47% Seem (AS), and 10.66% (GU). The herbal extracts used included 0.5 mg/mL STB, 1.5 mg/mL MP, 1.5 mg/mL AS, and 2.0 mg/mL GU. Antimicrobial tests, morphological analyses (using scanning electron microscopy), microbial surface hydrophobicity measurements, and oral malodor reduction tests were performed using each extract. Statistical analyses were performed with IBM SPSS (version 24), using paired -tests. : The mixed herbal extracts significantly inhibited the growth of and compared to the control ( < 0.001). Scanning electron microscopy results further revealed altered cellular morphology in the groups treated with the mixed herbal extracts. Additionally, the hydrophobicity assay results showed that the mixed herbal extracts reduced the oral adhesion capacities of bacteria ( < 0.001). Administration of the mixed herbal extracts also reduced the levels of volatile sulfur compounds, the main contributors to oral malodor ( < 0.001). : Edible mixed herbal extracts can effectively eliminate oral pathogens and may be useful for improving oral health. The herbal extracts used were effective against all species of oral pathogens studied in this report.
Topics: Humans; Plant Extracts; Halitosis; Streptococcus mutans; Anti-Infective Agents; Anti-Bacterial Agents
PubMed: 37893489
DOI: 10.3390/medicina59101771 -
Anais Da Academia Brasileira de Ciencias 2023Streptococcus mutans is one of the main factors in formation of cariogenic biofilms. New strategies need to be developed to reduce the formation of cariogenic biofilms....
Streptococcus mutans is one of the main factors in formation of cariogenic biofilms. New strategies need to be developed to reduce the formation of cariogenic biofilms. For this purpose, bacterial exopolysaccharides (EPS) could be considered as new agents against biofilms. Therefore, cell-bound (b-EPS) and released exopolysaccharides (r-EPS) were extracted from the strains Apilactobacillus kunkeei K1.10 and Latilactobacillus curvatus Kar.9b isolated from the microbiota of honeybees, and their antibiofilm effects on S. mutans biofilm formation were determined. The highest reduction in biofilm formation was achieved by r-EPS of L. curvatus Kar.9b and A. kunkeei K1.10. Scanning electron micrographs (SEM) showed that r-EPS inhibited biofilm formation by reducing adhesion of S. mutans. To increase the production of r-EPS from A. kunkeei K1.10, the effects of different incubation conditions were also analyzed. The highest EPS production was obtained during 48 h-incubation at 37ºC in a medium containing 1% fructose. r-EPS can be used as a raw material to inhibit cariogenic biofilms. Further studies revealing the detailed structural analysis of r-EPS and the mechanism of action of its antibiofilm effect could be beneficial. Finally, b-EPS and r-EPS from lactic acid bacteria were found to have very different properties in terms of their antibiofilm properties.
Topics: Bees; Animals; Streptococcus mutans; Lactobacillales; Biofilms
PubMed: 37878910
DOI: 10.1590/0001-3765202320220979 -
MicrobiologyOpen Oct 2023The oral cavity is colonized by a plethora of bacteria, fungi, and archaea, including streptococci of the mitis group (MSG) and the yeast Candida albicans. This study...
The oral cavity is colonized by a plethora of bacteria, fungi, and archaea, including streptococci of the mitis group (MSG) and the yeast Candida albicans. This study aims to investigate the role of streptococcal species in the development of oral biofilm and the cross-kingdom interactions between some of the members of the commensal MSG and the pathogen yeast C. albicans using a multispecies supragingival biofilm model. A total of nine different in vitro biofilms were grown, quantified with culture analyses, and visually examined with confocal laser scanning microscopy (CLSM). A four-species biofilm without any streptococcal species was used as a basic biofilm. In each subsequent inoculum, one species of MSG was added and afterward combined with Streptococcus mutans. The eight-species biofilm contained all eight strains used in this study. Culture analyses showed that the presence of S. mutans in a four-species biofilm with Streptococcus oralis or S. oralis subsp. tigurinus did not differ significantly in C. albicans colony-forming unit (CFU) counts compared to biofilms without S. mutans. However, compared to other mitis species, Streptococcus gordonii combined with S. mutans resulted in the lowest CFUs of C. albicans. Visual observation by CLSM showed that biofilms containing both S. mutans and one species of MSG seemed to induce the formation of filamentous form of C. albicans. However, when several species of MSG were combined with S. mutans, C. albicans was again found in its yeast form.
Topics: Candida albicans; Biofilms; Streptococcus mutans; Mouth; Streptococcus gordonii
PubMed: 37877656
DOI: 10.1002/mbo3.1381 -
Backbone NMR resonance assignments for the C terminal domain of the Streptococcus mutans adhesin P1.Biomolecular NMR Assignments Dec 2023Adhesin P1 (aka AgI/II) plays a pivotal role in mediating Streptococcus mutans attachment in the oral cavity, as well as in regulating biofilm development and...
Adhesin P1 (aka AgI/II) plays a pivotal role in mediating Streptococcus mutans attachment in the oral cavity, as well as in regulating biofilm development and maturation. P1's naturally occurring truncation product, Antigen II (AgII), adopts both soluble, monomeric and insoluble, amyloidogenic forms within the bacterial life cycle. Monomers are involved in important quaternary interactions that promote cell adhesion and the functional amyloid form promotes detachment of mature biofilms. The heterologous, 51-kD C123 construct comprises most of AgII and was previously characterized by X-ray crystallography. C123 contains three structurally homologous domains, C1, C2, and C3. NMR samples made using the original C123 construct, or its C3 domain, yielded moderately resolved NMR spectra. Using Alphafold, we re-analyzed the P1 sequence to better identify domain boundaries for C123, and in particular the C3 domain. We then generated a more tractable construct for NMR studies of the monomeric form, including quaternary interactions with other proteins. The addition of seven amino acids at the C-terminus greatly improved the spectral dispersion for C3 relative to the prior construct. Here we report the backbone NMR resonance assignments for the new construct and characterize some of its quaternary interactions. These data are in good agreement with the structure predicted by Alphafold, which contains additional β-sheet secondary structure compared to the C3 domain in the C123 crystal structure for a construct lacking the seven C-terminal amino acids. Its quaternary interactions with known protein partners are in good agreement with prior competitive binding assays. This construct can be used for further NMR studies, including protein-protein interaction studies and assessing the impact of environmental conditions on C3 structure and dynamics within C123 as it transitions from monomer to amyloid form.
Topics: Streptococcus mutans; Nuclear Magnetic Resonance, Biomolecular; Adhesins, Bacterial; Protein Structure, Secondary; Amyloid; Amino Acids
PubMed: 37864759
DOI: 10.1007/s12104-023-10158-y -
Clinical and Experimental Medicine Dec 2023Knowledge of the epidemiology of bloodstream infection (BSI) in haematology patients is essential to guide patient management. We investigated the epidemiology of BSI in...
Bloodstream infections in neutropenic and non-neutropenic patients with haematological malignancies: epidemiological trends and clinical outcomes in Queensland, Australia over the last 20 years.
Knowledge of the epidemiology of bloodstream infection (BSI) in haematology patients is essential to guide patient management. We investigated the epidemiology of BSI in patients with haematological malignancies in Queensland over the last 20 years (2000-2019), including all episodes diagnosed by the state-wide microbiology service. We identified 7749 BSI in 5159 patients, 58% associated with neutropenia. Gram-negatives were the main causative pathogens (58.3%), more frequent in neutropenic than non-neutropenic patients (3308/5309, 62.3% vs 1932/3678, 52.5%, p < 0.001). Amongst 8987 isolates the most common were E. coli (15.4%) and Pseudomonas spp. (14.2%). Pseudomonas spp. (16.6% vs 10.7%, p < 0.001), Klebsiella spp. (11.6% vs 6.8%, p < 0.001), viridans-group streptococci (4.4% vs 1.2%, p < 0.001) and E. faecium (2.4% vs 0.9%, p < 0.001) were more common in neutropenic than non-neutropenic patients, while S. aureus was less common (5.9% vs 15.6%, p < 0.001). Several antimicrobial resistance rates increased over time and had higher prevalence in neutropenic than non-neutropenic patients, including ciprofloxacin-resistant E. coli (94/758, 12.4% vs 42/506, 8.3%, p = 0.021), trimethoprim-sulfamethoxazole-resistant E. coli (366/764, 47.9% vs 191/517, 36.9%, p < 0.001), penicillin-resistant streptococci (51/236, 21.6% vs 28/260, 10.8%, p < 0.001) and vancomycin-resistant enterococci (46/250, 18.4% vs 9/144, 6.3%, p < 0.001). Carbapenem-resistant Pseudomonas spp. (OR 7.32, 95%CI 2.78-19.32) and fungi, including yeasts and moulds (OR 3.33, 95%CI 2.02-5.48) were associated to the highest odds of 30-day case-fatality at a multivariable logistic regression analysis. Neutropenia was associated with survival (OR 0.66, 95%CI 0.55-0.78). Differences were observed in the BSI epidemiology according to neutropenic status, with an overall increase of resistance over time associated to adverse outcome.
Topics: Humans; Bacteremia; Queensland; Escherichia coli; Staphylococcus aureus; Sepsis; Hematologic Neoplasms; Neutropenia; Australia; Anti-Bacterial Agents; Retrospective Studies
PubMed: 37815735
DOI: 10.1007/s10238-023-01206-x -
Dental and Medical Problems 2023With the recent use and development of nanomaterials, silver nanoparticles (AgNPs) are gaining much attention as a promising antibacterial agent for use in caries...
BACKGROUND
With the recent use and development of nanomaterials, silver nanoparticles (AgNPs) are gaining much attention as a promising antibacterial agent for use in caries prevention.
OBJECTIVES
This study aimed to biosynthesize AgNPs using chamomile extract as a reducing agent and to investigate its inhibitory effect against Streptococcus mutans (S. mutans) dental bacteria.
MATERIAL AND METHODS
Chamomile extract was prepared by sonication and added dropwise to silver nitrate (1mM) solution to synthesize AgNPs. Its formation was confirmed spectrophotometrically, and its size was determined. The disc diffusion method was used to test the antibacterial activity of the biosynthesized AgNPs against S. mutans. Also, its minimum inhibitory concentration (MIC) was assessed.
RESULTS
The spectrum of biosynthesized AgNPs showed a maximum peak at 454 nm, and the peak area increased with increasing time. The mean AgNP size was 41 nm. The inhibition zone diameter recorded for AgNPs against S. mutans was 10 mm, while the MIC was 280 μg/ml.
CONCLUSIONS
AgNPs biosynthesized using chamomile extract were proven to exert good antibacterial activity against cariogenic S. mutans. Using chamomile extract as a reducing agent can provide a rapid, affordable, and eco-friendly approach for AgNP production, which could be incorporated into various dental vehicles for dental caries prevention.
Topics: Humans; Dental Caries; Metal Nanoparticles; Streptococcus mutans; Reducing Agents; Silver; Anti-Bacterial Agents
PubMed: 37815513
DOI: 10.17219/dmp/152063 -
Dental Materials Journal Nov 2023Incorporating zinc oxide (ZnO) nanoparticles as antibacterial fillers in heat-cured acrylic resin could decrease mucin and Streptococcus mutans (S. mutans) adhesion,...
Incorporating zinc oxide (ZnO) nanoparticles as antibacterial fillers in heat-cured acrylic resin could decrease mucin and Streptococcus mutans (S. mutans) adhesion, reducing the incidence of dental caries in the baseplates of orthodontic patients. Here, ZnO nanoparticles were modified using 3-(trimethoxysilyl)propyl methacrylate with various concentrations, added to acrylic resin powder, homogenized, mixed with acrylic resin liquid, and processed. The composite systems interfered well with mucin and S. mutans adhesion. The lowest mean of the amount of mucin adhered was on heat-cured acrylic resin with 7.5% ZnO nanoparticles, with a standard deviation of 18.07±0.80 mg/mL. The ZnO nanoparticles with a concentration of 7.5% showed an 87.09±0.88% S. mutans adhesion in control groups with no additives. These composite systems were proven to have better physicochemical characteristics and antibacterial abilities. Combining ZnO nanoparticles with heat-cured acrylic resin has great potential for self-cleaning baseplates of orthodontic patients in the future.
Topics: Humans; Acrylic Resins; Zinc Oxide; Streptococcus mutans; Composite Resins; Mucins; Dental Caries; Hot Temperature; Nanoparticles; Anti-Bacterial Agents
PubMed: 37793826
DOI: 10.4012/dmj.2023-016 -
Applied and Environmental Microbiology Oct 2023Biofilms are complex polymicrobial communities which are often associated with human infections such as the oral disease periodontitis. Studying these complex...
Biofilms are complex polymicrobial communities which are often associated with human infections such as the oral disease periodontitis. Studying these complex communities under controlled conditions requires biofilm model systems that mimic the natural environment as close as possible. This study established a multispecies periodontal model in the drip flow biofilm reactor in order to mimic the continuous flow of nutrients at the air-liquid interface in the oral cavity. The design is engineered to enable real-time characterization. A community of five bacteria, -GFPmut3*, -GFPmut3*, -pVMCherry, , and -SNAP26 is visualized using two distinct fluorescent proteins and the SNAP-tag. The biofilm in the reactor develops into a heterogeneous, spatially uniform, dense, and metabolically active biofilm with relative cell abundances similar to those in a healthy individual. Metabolic activity, structural features, and bacterial composition of the biofilm remain stable from 3 to 6 days. As a proof of concept for our periodontal model, the 3 days developed biofilm is exposed to a prebiotic treatment with L-arginine. Multifaceted effects of L-arginine on the oral biofilm were validated by this model setup. L-arginine showed to inhibit growth and incorporation of the pathogenic species and to reduce biofilm thickness and volume. Additionally, L-arginine is metabolized by -GFPmut3* and -pVMCherry, producing high levels of ornithine and ammonium in the biofilm. In conclusion, our drip flow reactor setup is promising in studying spatiotemporal behavior of a multispecies periodontal community.ImportancePeriodontitis is a multifactorial chronic inflammatory disease in the oral cavity associated with the accumulation of microorganisms in a biofilm. Not the presence of the biofilm as such, but changes in the microbiota (i.e., dysbiosis) drive the development of periodontitis, resulting in the destruction of tooth-supporting tissues. In this respect, novel treatment approaches focus on maintaining the health-associated homeostasis of the resident oral microbiota. To get insight in dynamic biofilm responses, our research presents the establishment of a periodontal biofilm model including , , , , and . The added value of the model setup is the combination of simulating continuously changing natural mouth conditions with spatiotemporal biofilm profiling using non-destructive characterization tools. These applications are limited for periodontal biofilm research and would contribute in understanding treatment mechanisms, short- or long-term exposure effects, the adaptation potential of the biofilm and thus treatment strategies.
Topics: Humans; Bacteria; Streptococcus gordonii; Fusobacterium nucleatum; Streptococcus sanguis; Streptococcus oralis; Biofilms; Periodontitis; Arginine; Porphyromonas gingivalis
PubMed: 37768099
DOI: 10.1128/aem.01081-23 -
Biomolecules Aug 2023bacteria form a biofilm called plaque that causes oral diseases, including tooth decay. Therefore, inhibition of biofilm formation is essential to maintaining good oral...
bacteria form a biofilm called plaque that causes oral diseases, including tooth decay. Therefore, inhibition of biofilm formation is essential to maintaining good oral health. The health and nutritional benefits of are well documented, but very little is known about its use to treat against oral diseases. The aim of this study was to detect the adhesion strength of the bacterial biofilm in 100 cases in the Rajshahi region and evaluate the inhibitory activity of different compound extracts of on the bacterial biofilm by determining the composition of isolated compounds using phytochemical analysis. Nuclear magnetic resonance (NMR) spectroscopy confirmed that three specific compounds from were discovered in this study: 3,7,11,15 tetramethyl hexadec-2-4dien 1-o1, compound 3,7,11,15 tetramethylhexadec-2-en-1-o1 from phytol derivatives, and stigmasterol. Results indicated that the compound of 3,7,11,15-tetramethyl-hexadec-2-en-1-ol exhibited higher antibiofilm activities on than those of the other compound extracts. A lower level of minimum inhibitory concentration was exposed by 3, 7, 11,15 tetramethyl hexadeca-2-en-1-o1 (T2) on at 12.5 mL. In this case, the compound of 3,7,11,15 tetramethyl hexadec 2en-1-o1 was used, and patients showed a mean value and standard error reduced from 3.42 ± 0.21 to 0.33 ± 0.06 nm. The maximum inhibition was (80.10%) in the case of patient no. 17, with a value of < 0.05 found for to which 12.5 μL/mL ethyl acetate extract was applied. From these findings, it may be concluded that extracts can be incorporated into various oral preparations to prevent tooth decay.
Topics: Humans; Streptococcus mutans; Cynodon; Bangladesh; Biofilms; Cell Aggregation
PubMed: 37759692
DOI: 10.3390/biom13091292