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Photodiagnosis and Photodynamic Therapy Apr 2024Streptococcus mutans and Candida albicans are associated with caries recurrence. Therefore, this study evaluated the combination of a Ru(II)-loaded resin-based dental...
BACKGROUND
Streptococcus mutans and Candida albicans are associated with caries recurrence. Therefore, this study evaluated the combination of a Ru(II)-loaded resin-based dental material (RDM) and antimicrobial photodynamic therapy (aPDT) against a dual-species biofilm of S. mutans and C. albicans.
METHODS
An aPDT protocol was established evaluating Ru(II)'s photocatalytic activity and antimicrobial potential under blue LED irradiation (440-460 nm, 22.55 mW/cm) at different energy densities (0.00, 6.25, 20.25, 40.50 J/cm2). This evaluation involved singlet oxygen quantification and determination of minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC). The biofilm was grown (72 h) on resin disks prepared with Ru(II)-doped RDM (0.00, 0.56, or 1.12 %) and samples were exposed to aPDT or dark conditions. The biofilm was then harvested to analyze cell viability (CFU counts) and formation of soluble and insoluble exopolysaccharides.
RESULTS
The photocatalytic activity of Ru(II) was concentration and energy density dependent (p < 0.05), and MIC/MBC values were reduced for the microorganisms after LED irradiation (40.5 J/cm); therefor, this energy density was chosen for aPDT. Although incorporation of Ru(II) into RDM reduced the biofilm growth compared to Ru(II)-free RDM for both species in dark conditions (p < 0.05), aPDT combined with an Ru(II)-loaded RDM (0.56 or 1.12 %) potentialized CFU reductions (p < 0.05). Conversely, only 1.12 % Ru(II) with LED irradiation showed lower levels of both soluble and insoluble exopolysaccharides compared to Ru(II)-free samples in dark conditions (p < 0.05).
CONCLUSIONS
When the Ru(II)-loaded RDM was associated with blue LED, aPDT reduced cell viability and lower soluble and insoluble exopolysaccharides were found in the cariogenic dual-species biofilm.
Topics: Photochemotherapy; Biofilms; Streptococcus mutans; Photosensitizing Agents; Candida albicans; Ruthenium; Microbial Sensitivity Tests; Dental Materials; Singlet Oxygen; Dental Caries; Composite Resins
PubMed: 38395246
DOI: 10.1016/j.pdpdt.2024.104019 -
Clinical Oral Investigations Feb 2024To compare the antibacterial effect of Nanosilver Fluoride varnish (NSF) varnish, P11-4 and Sodium Fluoride (NaF) varnish against salivary Streptococcus mutans (S.... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES
To compare the antibacterial effect of Nanosilver Fluoride varnish (NSF) varnish, P11-4 and Sodium Fluoride (NaF) varnish against salivary Streptococcus mutans (S. mutans) and Lactobacilli.
METHODS
66 patients aged 10-24 years old were randomly assigned to receive single application of NSF, P11-4 or NaF varnish. Baseline unstimulated saliva samples were collected before the agents were applied and S.mutans and Lactobacilli colony forming units (CFU) were counted. After one, three and six months, microbiological samples were re-assessed. Groups were compared at each time point and changes across time were assessed. Multivariable linear regression compared the effect of P11-4 and NSF to NaF on salivary S. mutans and Lactobacilli log count at various follow up periods.
RESULTS
There was a significant difference in salivary S. mutans log count after 1 month between P11-4 (B= -1.29, p = 0.049) and NaF but not at other time points nor between NSF and NaF at any time point. The significant reduction in bacterial counts lasted up to one month in all groups, to three months after using P11-4 and NaF and returned to baseline values after six months.
CONCLUSION
In general, the antimicrobial effect of P11-4 and NSF on salivary S. mutans and Lactobacilli was not significantly different from NaF varnish. P11-4 induced greater reduction more quickly than the two other agents and NSF antibacterial effect was lost after one month.
CLINICAL RELEVANCE
NSF varnish and P11-4 have antimicrobial activity that does not significantly differ from NaF by 3 months. P11-4 has the greatest antibacterial effect after one month with sustained effect till 3 months. The antibacterial effect of NSF lasts for one month. NaF remains effective till 3 months.
TRIAL REGISTRATION
This trial was prospectively registered on the clinicaltrials.gov registry with ID: NCT04929509 on 18/6/2021.
Topics: Adolescent; Child; Humans; Young Adult; Anti-Bacterial Agents; Anti-Infective Agents; Dental Caries; Fluorides; Fluorides, Topical; Silver Compounds; Sodium; Sodium Fluoride; Streptococcus mutans; Nanostructures
PubMed: 38388987
DOI: 10.1007/s00784-024-05562-0 -
Microbiology Spectrum Apr 2024The oral microbiome plays an important role in protecting oral health. Here, we established a controlled mixed-species biofilm model and used it to assess the impact of...
The oral microbiome plays an important role in protecting oral health. Here, we established a controlled mixed-species biofilm model and used it to assess the impact of glucose and lactate on the ability of , an acidogenic and aciduric species, to compete with commensal oral bacteria. A chemically defined medium was developed that supported the growth of and four common early colonizers of dental plaque: , , , and . Biofilms containing the early colonizers were developed in a continuous flow bioreactor, exposed to , and incubated for up to 7 days. The abundance of bacteria was estimated by quantitative polymerase chain reaction (qPCR). At high glucose and high lactate, the pH in bulk fluid rapidly decreased to approximately 5.2, and outgrew other species in biofilms. In low glucose and high lactate, the pH remained above 5.5, and was the most abundant species in biofilms. By contrast, in low glucose and low lactate, the pH remained above 6.0 throughout the experiment, and the microbial community in biofilms was relatively balanced. Fluorescence hybridization confirmed that all species were present in the biofilm and the majority of cells were viable using live/dead staining. These data demonstrate that carbon source concentration is critical for microbial homeostasis in model oral biofilms. Furthermore, we established an experimental system that can support the development of computational models to predict transitions to microbial dysbiosis based on metabolic interactions.IMPORTANCEWe developed a controlled (by removing host factor) dynamic system metabolically representative of early colonization of not measurable . Hypotheses on factors influencing colonization, such as community composition and inoculation sequence and the effect of metabolite concentrations, can be tested and used to predict the effect of interventions such as dietary modifications or the use of toothpaste or mouthwash on colonization. The defined model (species and medium) can be simulated in an model to explore more of the parameter space.
Topics: Streptococcus mutans; Lactic Acid; In Situ Hybridization, Fluorescence; Glucose; Biofilms
PubMed: 38376204
DOI: 10.1128/spectrum.03713-23 -
EBioMedicine Mar 2024Lifestyle- and sucrose-dependent polymicrobial ecological shifts are a primary cause of caries in populations with high caries prevalence. In populations with low...
BACKGROUND
Lifestyle- and sucrose-dependent polymicrobial ecological shifts are a primary cause of caries in populations with high caries prevalence. In populations with low prevalence, PRH1, PRH2 susceptibility and resistance phenotypes may interact with the Streptococcus mutans adhesin cariogenicity phenotype to affect caries progression, but studies are lacking on how these factors affect the microbial profile of caries.
METHODS
We analysed how the residency and infection profiles of S. mutans adhesin (SpaP A/B/C and Cnm/Cbm) phenotypes and commensal streptococci and lactobacilli influenced caries progression in a prospective case-referent sample of 452 Swedish adolescents with high (P4a), moderate (P6), and low (P1) caries PRH1, PRH2 phenotypes. Isolates of S. mutans from participants were analysed for adhesin expression and glycosylation and in vitro and in situ mechanisms related to caries activity.
FINDINGS
Among adolescents with the resistant (P1) phenotype, infection with S. mutans high-virulence phenotypes was required for caries progression. In contrast, with highly (P4a) or moderately (P6) susceptible phenotypes, caries developed from a broader polymicrobial flora that included moderately cariogenic oral commensal streptococci and lactobacilli and S. mutans phenotypes. High virulence involved unstable residency and fluctuating SpaP ABC, B-1, or Cnm expression/glycosylation phenotypes, whereas low/moderate virulence involved SpaP A phenotypes with stable residency. Adhesin phenotypes did not display changes in individual host residency but were paired within individuals and geographic regions.
INTERPRETATION
These results suggest that receptor PRH1, PRH2 susceptibility and resistance and S. mutans adhesin virulence phenotypes specify different microbial profiles in caries.
FUNDING
Swedish Research Council and funding bodies listed in the acknowledgement section.
Topics: Adolescent; Humans; Streptococcus mutans; Virulence; Dental Caries Susceptibility; Biofilms; Adhesins, Bacterial; Phenotype
PubMed: 38364699
DOI: 10.1016/j.ebiom.2024.105001 -
International Journal of Nanomedicine 2024To investigate the inhibition of Streptococcus mutans (S.mutans) and its biofilm by AgBr-nanoparticles (NP) @CTMAB (cetyltrimethyl-ammonium bromide) and evaluate the...
PURPOSE
To investigate the inhibition of Streptococcus mutans (S.mutans) and its biofilm by AgBr-nanoparticles (NP) @CTMAB (cetyltrimethyl-ammonium bromide) and evaluate the changes in Polymethyl methacrylate (PMMA)'s surface roughness (Ra), microhardness, and flexural strength during prolonged immersion in AgBr-NP@CTMAB for application in the denture cleaning industry.
PATIENTS AND METHODS
The antibacterial activity of AgBr-NP@CTMAB against S.mutans was measured colony formation assay, OD600 and laser confocal microscopy. Changes in the specimens' values for surface roughness, microhardness, and flexural strength (MPa) were measured after immersion solutions for 180 or 360 days.
RESULTS
The AgBr-NP@CTMAB solution exhibited a robust antibacterial effect on planktonic S. mutans, with a minimum bactericidal concentration of 5 µg/mL. The 10 µg/mL AgBr-NP@CTMAB solution efficiently inhibited S. mutans biofilm formation. (2) No significant difference in surface roughness after immersion in AgBr-NP@CTMAB (10 µg/mL and 20 µg/mL) comparing with distilled water (P > 0.05) and Polident had significantly higher than distilled water (P < 0.05). There was a significant decrease in the surface hardness of the PMMA specimens that were immersed in the Polident compared with those in distilled water (P < 0.05). While, no significant differences in surface hardness after immersion in the AgBr-NP@CTMAB (P > 0.05). The result of flexural strength suggested that there was no statistically significant difference (P < 0.05) between AgBr-NP@CTMAB as well as Polident and water.
CONCLUSION
AgBrNP@CTMAB can efficiently inhibit the growth of plankton S.mutans and biofilm formation, without affecting the flexural strength, microhardness, or surface roughness of PMMA. Therefore, AgBrNP@CTMAB holds promise as a new denture cleaning agent.
Topics: Polymethyl Methacrylate; Hardness; Flexural Strength; Streptococcus mutans; Denture Bases; Nanoparticles; Water; Anti-Bacterial Agents; Surface Properties; Materials Testing; Borates; Sulfates
PubMed: 38348176
DOI: 10.2147/IJN.S436613 -
Frontiers in Cellular and Infection... 2024Improved understanding of throat colonization in the presence of other co-existing microbes is important for mapping adaptation to the human throat, and recurrence of...
INTRODUCTION
Improved understanding of throat colonization in the presence of other co-existing microbes is important for mapping adaptation to the human throat, and recurrence of infection. Here, we explore the responses triggered by the encounter between two common throat bacteria, and , to identify genes in that are important for colonization in the presence of human tonsillar epithelial cells and , and further compare this transcriptome with the genes expressed in as only bacterium.
METHODS
We performed an co-culture experiment followed by RNA sequencing to identify interaction-induced transcriptional alterations and differentially expressed genes (DEGs), followed by gene enrichment analysis.
RESULTS AND DISCUSSION
A total of 332 and 279 significantly differentially expressed genes with p-value < 0.05 and log FoldChange (logFC) ≥ |2| were identified in after 1 h and 3 h co-culturing, respectively. Alterations in expression of various survival factors were observed when co-cultured with and tonsillar cells. The serine-aspartate repeat-containing protein D () involved in adhesion, was for example highly upregulated in during co-culturing with compared to grown in the absence of , especially at 3 h. Several virulence genes encoding secreted proteins were also highly upregulated only when was co-cultured with and tonsillar cells, and iron does not appear to be a limiting factor in this environment. These findings may be useful for the development of interventions against throat colonization and could be further investigated to decipher the roles of the identified genes in the host immune response in context of a throat commensal landscape.
Topics: Humans; Staphylococcus aureus; Transcriptome; Streptococcus anginosus; Coculture Techniques; Staphylococcal Infections
PubMed: 38333035
DOI: 10.3389/fcimb.2024.1326730 -
MSphere Feb 2024The bacteria within supragingival biofilms participate in complex exchanges with other microbes inhabiting the same niche. One example is the mutans group streptococci...
UNLABELLED
The bacteria within supragingival biofilms participate in complex exchanges with other microbes inhabiting the same niche. One example is the mutans group streptococci (s), implicated in the development of tooth decay, and other health-associated commensal streptococci species. Previously, our group transcriptomically characterized intermicrobial interactions between and several species of oral bacteria. However, these experiments were carried out in a medium without human saliva. To better mimic their natural environment, we first evaluated how inclusion of saliva affected growth and biofilm formation of eight species individually and found saliva to positively benefit growth rates while negatively influencing biofilm biomass accumulation and altering spatial arrangement. These results carried over during evaluation of 29 saliva-derived isolates of various species. Surprisingly, we also found that addition of saliva increased the competitive behaviors of in coculture competitions against commensal streptococci that led to increases in biofilm microcolony volumes. Through transcriptomically characterizing mono- and cocultures of and with and without saliva, we determined that each species developed a nutritional niche under mixed-species growth, with upregulating carbohydrate uptake and utilization pathways while upregulated genome features related to peptide uptake and glycan foraging. also upregulated genes involved in oxidative stress tolerance, particularly manganese uptake, which we could artificially manipulate by supplementing in manganese leading to an advantage over its opponent. Our report highlights observable changes in microbial behaviors through leveraging environmental- and host-supplied resources over their competitors.
IMPORTANCE
Dental caries (tooth decay) is the most prevalent disease for both children and adults nationwide. Caries are initiated from demineralization of the enamel due to organic acid production through the metabolic activity of oral bacteria growing in biofilm communities attached to the tooth's surface. Mutans group streptococci are closely associated with caries development and initiation of the cariogenic cycle, which decreases the amount of acid-sensitive, health-associated commensal bacteria while selecting for aciduric and acidogenic species that then further drives the disease process. Defining the exchanges that occur between mutans group streptococci and oral commensals in a condition that closely mimics their natural environment is of critical need toward identifying factors that can influence odontopathogen establishment, persistence, and outgrowth. The goal of our research is to develop strategies, potentially through manipulation of microbial interactions characterized here, that prevent the emergence of mutans group streptococci while keeping the protective flora intact.
Topics: Child; Humans; Saliva; Competitive Behavior; Dental Caries; Manganese; Streptococcus; Streptococcus mutans; Biofilms
PubMed: 38319113
DOI: 10.1128/msphere.00771-23 -
Cell Feb 2024Streptococcus anginosus (S. anginosus) was enriched in the gastric mucosa of patients with gastric cancer (GC). Here, we show that S. anginosus colonized the mouse...
Streptococcus anginosus (S. anginosus) was enriched in the gastric mucosa of patients with gastric cancer (GC). Here, we show that S. anginosus colonized the mouse stomach and induced acute gastritis. S. anginosus infection spontaneously induced progressive chronic gastritis, parietal cell atrophy, mucinous metaplasia, and dysplasia in conventional mice, and the findings were confirmed in germ-free mice. In addition, S. anginosus accelerated GC progression in carcinogen-induced gastric tumorigenesis and YTN16 GC cell allografts. Consistently, S. anginosus disrupted gastric barrier function, promoted cell proliferation, and inhibited apoptosis. Mechanistically, we identified an S. anginosus surface protein, TMPC, that interacts with Annexin A2 (ANXA2) receptor on gastric epithelial cells. Interaction of TMPC with ANXA2 mediated attachment and colonization of S. anginosus and induced mitogen-activated protein kinase (MAPK) activation. ANXA2 knockout abrogated the induction of MAPK by S. anginosus. Thus, this study reveals S. anginosus as a pathogen that promotes gastric tumorigenesis via direct interactions with gastric epithelial cells in the TMPC-ANXA2-MAPK axis.
Topics: Animals; Humans; Mice; Atrophy; Carcinogenesis; Cell Transformation, Neoplastic; Gastric Mucosa; Gastritis; Inflammation; Mitogen-Activated Protein Kinases; Stomach Neoplasms; Streptococcus anginosus; Streptococcal Infections
PubMed: 38295787
DOI: 10.1016/j.cell.2024.01.004 -
Infection and Immunity Mar 2024Oral streptococci, key players in oral biofilm formation, are implicated in oral dysbiosis and various clinical conditions, including dental caries, gingivitis,...
Oral streptococci, key players in oral biofilm formation, are implicated in oral dysbiosis and various clinical conditions, including dental caries, gingivitis, periodontal disease, and oral cancer. Specifically, is associated with esophageal, gastric, and pharyngeal cancers, while is linked to oral cancer. However, no study has investigated the mechanistic links between these species and cancer-related inflammatory responses. As an initial step, we probed the innate immune response triggered by and in RAW264.7 macrophages. These bacteria exerted time- and dose-dependent effects on macrophage morphology without affecting cell viability. Compared with untreated macrophages, macrophages infected with exhibited a robust proinflammatory response characterized by significantly increased levels of inflammatory cytokines and mediators, including TNF, IL-6, IL-1β, NOS2, and COX2, accompanied by enhanced NF-κB activation. In contrast, -infected macrophages failed to elicit a robust inflammatory response. Seahorse Xfe96 analysis revealed an increased extracellular acidification rate in macrophages infected with compared with . At the 24-h time point, the presence of led to reduced extracellular itaconate, while triggered increased itaconate levels, highlighting distinct metabolic profiles in macrophages during infection in contrast to aconitate decarboxylase expression observed at the 6-h time point. This initial investigation highlights how and , two Gram-positive bacteria from the same genus, can prompt distinct immune responses and metabolic shifts in macrophages during infection.IMPORTANCEThe surge in head and neck cancer cases among individuals devoid of typical risk factors such as Human Papilloma Virus (HPV) infection and tobacco and alcohol use sparks an argumentative discussion around the emerging role of oral microbiota as a novel risk factor in oral squamous cell carcinoma (OSCC). While substantial research has dissected the gut microbiome's influence on physiology, the oral microbiome, notably oral streptococci, has been underappreciated during mucosal immunopathogenesis. , a viridans streptococci group, has been linked to abscess formation and an elevated presence in esophageal cancer and OSCC. The current study aims to probe the innate immune response to compared with the early colonizer as an important first step toward understanding the impact of distinct oral species on the host immune response, which is an understudied determinant of OSCC development and progression.
Topics: Humans; Streptococcus anginosus; Carcinoma, Squamous Cell; Mouth Neoplasms; Dental Caries; Streptococcus; Macrophages; Succinates
PubMed: 38289109
DOI: 10.1128/iai.00536-23 -
International Journal of Molecular... Jan 2024The effects of TiO nanotube (TNT) and reduced graphene oxide (rGO) deposition onto titanium, which is widely used in dental implants, on () and preosteoblastic cells...
The effects of TiO nanotube (TNT) and reduced graphene oxide (rGO) deposition onto titanium, which is widely used in dental implants, on () and preosteoblastic cells were evaluated. TNTs were formed through anodic oxidation on pure titanium, and rGO was deposited using an atmospheric plasma generator. The specimens used were divided into a control group of titanium specimens and three experimental groups: Group N (specimens with TNT formation), Group G (rGO-deposited specimens), and Group NG (specimens under rGO deposition after TNT formation). Adhesion of to the surface was assessed after 24 h of culture using a crystal violet assay, while adhesion and proliferation of MC3T3-E1 cells, a mouse preosteoblastic cell line, were evaluated after 24 and 72 h through a water-soluble tetrazolium salt assay. TNT formation and rGO deposition on titanium decreased adhesion ( < 0.05) and increased MC3T3-E1 cell adhesion and proliferation ( < 0.0083). In Group NG, adhesion was the lowest ( < 0.05), while MC3T3-E1 cell proliferation was the highest ( < 0.0083). In this study, TNT formation and rGO deposition on a pure titanium surface inhibited the adhesion of at an early stage and increased the initial adhesion and proliferation of preosteoblastic cells.
Topics: Mice; Animals; Streptococcus mutans; Titanium; Surface Properties; Nanotubes; Graphite
PubMed: 38279351
DOI: 10.3390/ijms25021351