Pathogen Streptococcus Mutans Research Articles

Selective Biofilm Inhibition through Mucin-Inspired Engineering of Silk Glycopolymers.

Mucins are key components of innate immune defense and possess remarkable abilities to manage pathogenic microbes while supporting beneficial ones and maintaining microbial homeostasis at mucosal surfaces. Their unique properties have garnered significant interest in developing mucin-inspired materials as novel therapeutic strategies for selectively controlling pathogens without disrupting the overall microbial ecology. However, natural mucin production is challenging to scale, driving the need for simpler materials that reproduce mucin's bioactivity. In this work, we generated silk-based glycopolymers with different monosaccharides (GalNAc, GlcNAc, NeuNAc, GlcN, and GalN) and different grafting densities. Using the oral cavity as a model system, we treated in vitro cultures of pathogenic Streptococcus mutans and commensal Streptococcus sanguinis with our glycopolymers, finding that silk-tethered GalNAc uniquely prevented biofilm formation without affecting overall bacterial growth of either species. This relatively simple material reproduced mucin's virulence-neutralizing effects while maintaining biocompatibility. These mucin-inspired materials represent a valuable tool for preventing infection-related harm and offer a strategy for the domestication of pathogens in other environments.

Monomelittoside and Dichotomoside D from bark extract of Alstonia scholaris (L.) R. Br. inhibits dental caries pathogen Streptococcus mutans

Dental caries advances to be a significant global health concern, primarily attributed to the virulent actions of Streptococcus mutans. The antibacterial property of the bark extract of Alstonia scholaris was assessed using standard disc diffusion assays, which revealed significant inhibition of S. mutans. Subsequently, we determined the Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) revealed potent antibacterial activity of bark extract against S. mutans, at MIC and MBC values 62.5 and 125 µg/mL, respectively and antibiofilm activity at 125 µg/mL. Furthermore, cytotoxicity assays showed no adverse effects on mammalian cells. Moreover, we employed liquid chromatography–mass spectrometry to identify bioactive compounds in the bark extract and revealed the presence of major active compounds as Monomelittoside and Dichotomoside D effective in targeting the S. mutans. These findings showed that, the promising antibacterial efficacy of Monomelittoside and Dichotomoside D, highlighting their potential as natural therapeutics for combating dental caries.

Oral Anti-Inflammatory and Symbiotic Effects of Fermented Lingonberry Juice-Potential Benefits in IBD.

Microbial dysbiosis may manifest as inflammation both orally and in the gastrointestinal tract. Altered oral and gut microbiota composition and decreased diversity have been shown in inflammatory bowel disease (IBD) and periodontal disease (PD). Recent studies have verified transmission of oral opportunistic microbes to the gut. Prebiotics, probiotics, or dietary interventions are suggested to alleviate IBD symptoms in addition to medicinal treatment. Lingonberries contain multiple bioactive molecules, phenolics, which have a broad spectrum of effects, including antimicrobial, anti-inflammatory, antioxidant, anti-proteolytic, and anti-cancer properties. An all-natural product, fermented lingonberry juice (FLJ), is discussed as a potential natural anti-inflammatory substance. FLJ has been shown in clinical human trials to promote the growth of oral lactobacilli, and inhibit growth of the opportunistic oral pathogens Candida, Streptococcus mutans, and periodontopathogens, and decrease inflammation, oral destructive proteolysis (aMMP-8), and dental microbial plaque load. Lactobacilli are probiotic and considered also beneficial for gut health. Considering the positive outcome of these oral studies and the fact that FLJ may be swallowed safely, it might be beneficial also for the gut mucosa by balancing the microbiota and reducing proteolytic inflammation.

Triple-function carbon-based Ca2+ ion-selective pH ring microelectrode to study real-time bacteria-mediated hydroxyapatite corrosion

BackgroundThe local pH change mediated by the pathogenic bacterial species Streptococcus mutans plays a significant role in the corrosion of hydroxyapatite (HA) present in the tooth in the dynamic oral cavity. The acid produced by the bacteria decreases the local pH and releases Ca2+ ions from the HA. We studied the bacteria-mediated demineralization of HA by scanning electrochemical microscopy (SECM) after growing S. mutans biofilm on HA for 7 days. ResultsWe notably developed a triple-function SECM-compatible tip that could be positioned above the biofilm. It can also measure the pH and [Ca2+] change simultaneously above the biofilm-HA substrate. The triple-function SECM tip is a combination of a potentiometric pH sensor deposited with iridium oxide and a dual-function carbon-based Ca2+ ion-selective membrane electrode with a slope of 67 mV/pH and 34.3 mV/log [Ca2+], respectively. The distance-controlled triple-function SECM tip monitored real-time pH and [Ca2+] changes 30 μm above the S. mutans biofilm. The high temporal resolution pH data demonstrated that after approximately 20 min of sucrose addition, S. mutans started to produce acid to titrate the solution buffer, causing a pH change from 7.2 to 6.5 for HA and from 7.2 to 5 for the glass substrate. We observed that, after 30 min of acid production, ∼300 μM of Ca2+ ions were increased at pH 6.5 above the biofilm surface as a result of the pH change in the local microenvironment. After the release of Ca2+ from HA, the pH environment again shifted toward the neutral side, from 6.5 to 7.2. Therefore, precipitation of Ca2+ happens at the top of the biofilm, thus corroding the HA from underneath. For a glass substrate, in contrast, no Ca2+ ions were released, and the pH did not change back to 7.2. We were able to observe the dynamics of the HA demineralization–remineralization process simultaneously with our newly developed triple-function SECM tip or microprobe. SignificanceThis technique could notably advance the study of similar complex processes, such as bacteria-mediated corrosion in biomedical and environmental contexts.

Formulation and Evaluation of Toothpaste Combining Clove Flower Extract (Syzygium aromaticum L.) and Chamomile Flower Essential Oil (Matricaria chamomilla)

Introduction: Herbal remedies like clove and chamomile have been traditionally used for their potential oral health benefits. This study aimed to formulate and evaluate a toothpaste combining clove flower extract (Syzygium aromaticum L.) and chamomile flower essential oil (Matricaria chamomilla) for its efficacy in promoting oral hygiene. Methods: Clove flower extract was obtained through ethanol extraction, while chamomile essential oil was procured commercially. Various toothpaste formulations (F1-F3) were prepared with varying concentrations of the herbal extracts, alongside a control formulation (F0) without the extracts. The formulations underwent comprehensive evaluation, including organoleptic assessment, pH determination, homogeneity testing, and foam height analysis. Additionally, antimicrobial activity against common oral pathogens (Streptococcus mutans and Staphylococcus aureus) was assessed using the agar well diffusion method. Results: All formulations (F0-F3) exhibited acceptable organoleptic properties, pH levels within the safe range for oral use, and homogeneity. However, foam height varied among formulations, with F1-F3 showing lower foam compared to the control (F0). Notably, F2 and F3 demonstrated significant antimicrobial activity against both S. mutans and S. aureus, suggesting their potential in combating oral pathogens. Conclusion: The combination of clove flower extract and chamomile essential oil in toothpaste formulations holds promise for enhancing oral hygiene due to their antimicrobial properties. Further research is warranted to optimize foam height and explore the long-term clinical effects of this herbal toothpaste.

Chemical composition, cytotoxicity, antimicrobial, antibiofilm, and anti-quorum sensing potential of Mentha Piperita essential oil against the oral pathogen Streptococcus mutans

ABSTRACT Dental caries is a highly prevalent oral disease affecting billions of individuals globally. The disease occurs chemically as a result of breakdown of the tooth surface attributed to metabolic activity in colonizing biofilm. Biofilms, composed of exopolysaccharides and proteins, protect bacteria like Streptococcus mutans, which is notable for its role in tooth decay due to its acid-producing abilities. While various antimicrobial agents may prevent biofilm formation, these drugs often produce side effects including enamel erosion and taste disturbances. This study aimed to examine utilization of the Mentha piperita essential oil as a potential antibiofilm activity agent against S. mutans. M. piperita oil significantly (1) reduced bacterial biofilm, (2) exhibited a synergistic effect when combined with chlorhexidine, and (3) did not induce cell toxicity. Chemical analysis identified the essential oil with 99.99% certainty, revealing menthol and menthone as the primary components, constituting approximately 42% and 26%, respectively. Further, M. piperita oil eradicated preformed biofilms and inhibited biofilm formation at sub-inhibitory concentrations. M. piperita oil also interfered with bacterial quorum sensing communication and did not produce any apparent cell toxicity in immortalized human keratinocytes (HaCaT). M. piperita represented an alternative substance for combating S. mutans and biofilm formation and a potential combination option with chlorhexidine to minimize side effects. An in-situ performance assessment requires further studies.

Comprehensive in vitro and in vivo evaluation of therapeutic potential of Bacopa-derived asiatic acid against a human oral pathogen Streptococcus mutans.

Dental caries is a common human oral disease worldwide, caused by an acid-producing bacteria Streptococcus mutans. The use of synthetic drugs and antibiotics to prevent dental caries has been increasing, but this can lead to severe side effects. To solve this issue, developing and developed countries have resorted to herbal medicines as an alternative to synthetic drugs for the treatment and prevention of dental caries. Therefore, there is an urgent need for plant-derived products to treat such diseases. Bacopa monnieri, a well-documented medicinal plant, contains 52 phytocompounds, including the pentacyclic triterpenoid metabolite known as asiatic acid (ASTA). Hence, this study aimed to demonstrate, for the first time, the antibacterial activity of phytocompound ASTA against S. mutans. The findings revealed that ASTA significantly inhibited the growth of S. mutans and the production of virulence factors such as acidurity, acidogenicity, and eDNA synthesis. Molecular docking analysis evaluated the potential activity of ASTA against S. mutans virulence genes, including VicR and GtfC. Furthermore, toxicity assessment of ASTA in human buccal epithelial cells was performed, and no morphological changes were observed. An in vivo analysis using Danio rerio (zebrafish) confirmed that the ASTA treatment significantly increased the survival rates of infected fish by hindering the intestinal colonization of S. mutans. Furthermore, the disease protection potential of ASTA against the pathognomonic symptom of S. mutans infection was proven by the histopathological examination of the gills, gut, and kidney. Overall, these findings suggest that ASTA may be a promising therapeutic and alternative drug for the treatment and prevention of oral infection imposed by S. mutans.

Chitosan from the base of Flammulina velutipes stipe alleviates oral Candida albicans infection via modulating Th-17 cell differentiation and Streptococcus mutans

The base of Flammulina velutipes (F. velutipes) stipe are agricultural wastes generated during the cultivation of edible fungus F. velutipes with high amount of chitin. Herein, this study firstly prepared chitosan from the base of F. velutipes stipe (FVC) and its structure was identified. It was confirmed that FVC acted as an antigenic substance to activate the immune system in vivo and in vitro, drive T cells to differentiate into Th-17 cells, and establish an effective mucosal immune barrier in the oral cavity, thus inhibited C. albicans infection; On the other hand, FVC maintained the oral flora stability and significantly reduced the abundance of Streptococcus spp., which was closely related to C. albicans infection. On this basis, the inhibitory effects of FVC on oral pathogens Streptococcus mutans and Lactobacillus casei associated with C. albicans infection were further verified, and it was demonstrated that FVC effectively interfered with the growth of pathogenic bacteria by inducing the production of intracellular ROS to damage bacterial cells. Therefore, FVC may be potentially exploited as a novel approach to the prevention and treatment of oral C. albicans infection.

Dental Caries Management with Antibacterial Silver-Doped Prussian Blue Hydrogel by the Combined Effects of Photothermal Response and Ion Discharge.

Caries is a destructive condition caused by bacterial infection that affects the hard tissues of the teeth, significantly reducing the quality of life for individuals. Photothermal therapy (PTT) offers a noninvasive and painless treatment for caries, but the use of unsafe laser irradiance limits its application. To address this challenge, we prepared nanoparticles of silver ion-doped Prussian blue (AgPB), which was encased within cationic guar gum (CG) to form the antibacterial PTT hydrogel CG-AgPB with a photothermal conversion efficiency of 34.4%. When exposed to an 808 nm laser at a power density of 0.4 W/cm2, the hydrogel readily reached a temperature of over 50 °C in just 3 min, synchronized by the discharge of Ag+ ions from the interstitial sites of AgPB crystals, resulting in broad-spectrum and synergistic antibacterial activities (>99%) against individual oral pathogens (Streptococcus sanguinis, Streptococcus mutans, and Streptococcus sobrinus) and pathogen-induced biofilms. In vivo, CG-AgPB-mediated PTT demonstrated a capability to profoundly reduce the terminal number of cariogenic bacteria to below 1% in a rat model of caries. Given the outstanding biocompatibility, injectability, and flushability, this CG-AgPB hydrogel may hold promise as a next-generation oral hygiene adjunct for caries management in a clinical setting.

Marine Microalgae Schizochytrium sp. S31: Potential Source for New Antimicrobial and Antibiofilm Agent.

The rise of antibiotic-resistant bacteria necessitates the discovery of new, safe, and bioactive antimicrobial compounds. The antibacterial and antibiofilm activity of microalgae makes them a potential candidate for developing natural antibiotics to limit microbial infection in various fields. This study aimed to analyze the antibacterial effect of the methanolic extract of Schizochytrium sp. S31 microalgae by broth microdilution and spot plate assays. The antibacterial effects of Schizochytrium sp. S31 extract was studied on gramnegative pathogens, Pseudomonas aeruginosa, Escherichia coli 35218, Klebsiella pneumonia, which cause many different human infections, and the gram-positive pathogen Streptococcus mutans. At the same time, the antibiofilm activity of the Schizochytrium sp. S31 extract on Pseudomonas aeruginosa and Escherichia coli 35218 bacteria were investigated by crystal violet staining method. Schizochytrium sp. S31 extract at a 60% concentration for 8 hours displayed the highest antibacterial activity against P. aeruginosa, E. coli 35218, and K. pneumonia, with a decrease of 87%, 92%, and 98% in cell viability, respectively. The experiment with Streptococcus mutans revealed a remarkable antibacterial effect at a 60% extract concentration for 24 hours, leading to a notable 93% reduction in cell viability. Furthermore, the extract exhibited a dose-dependent inhibition of biofilm formation in P. aeruginosa and E. coli 35218. The concentration of 60% extract was identified as the most effective dosage in terms of inhibition. This research emphasizes the potential of Schizochytrium sp. S31 as a natural antibacterial and antibiofilm agent with promising applications in the pharmaceutical sectors. This is the first study to examine the antibacterial activity of Schizochytrium sp. S31 microalgae using broth microdilution, spot plate assays, and the antibiofilm activity by a crystal staining method. The findings of this study show that Schizochytrium sp. S31 has antibacterial and antibiofilm activities against critical bacterial pathogens.

Nanofibrous ε-Polycaprolactone Matrices Containing Nano-Hydroxyapatite and Humulus lupulus L. Extract: Physicochemical and Biological Characterization for Oral Applications.

Oral bone defects occur as a result of trauma, cancer, infections, periodontal diseases, and caries. Autogenic and allogenic grafts are the gold standard used to treat and regenerate damaged or defective bone segments. However, these materials do not possess the antimicrobial properties necessary to inhibit the invasion of the numerous deleterious pathogens present in the oral microbiota. In the present study, poly(ε-caprolactone) (PCL), nano-hydroxyapatite (nHAp), and a commercial extract of Humulus lupulus L. (hops) were electrospun into polymeric matrices to assess their potential for drug delivery and bone regeneration. The fabricated matrices were analyzed using scanning electron microscopy (SEM), tensile analysis, thermogravimetric analysis (TGA), FTIR assay, and in vitro hydrolytic degradation. The antimicrobial properties were evaluated against the oral pathogens Streptococcus mutans, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans. The cytocompatibility was proved using the MTT assay. SEM analysis established the nanostructured matrices present in the three-dimensional interconnected network. The present research provides new information about the interaction of natural compounds with ceramic and polymeric biomaterials. The hop extract and other natural or synthetic medicinal agents can be effectively loaded into PCL fibers and have the potential to be used in oral applications.

Free Radical Scavenging, Anti-inflammatory and Antibacterial Activity of Acorus calamus Leaves Extract Against Pseudomonas aeruginosa and Staphylococcus aureus.

Background Herbal medicine, or phytotherapy, has been used for centuries in traditional healing practices to harness the therapeutic properties of different plant-derived elements. Acorus calamus, a perennial herbaceous plant, has significant historical importance in traditional medicine, specifically in Ayurveda, where it is referred to as "Vacha."This study investigates the antioxidant, anti-inflammatory, and antimicrobial characteristics of the A. calamus dimethyl sulfoxide (DMSO) extract. The objectives of the research are to provide valuable knowledge about the preparation of A. calamus DMSO extract and to explore its potential anti-inflammatory, antioxidant, and antimicrobial effects. Materials and methods The A. calamus DMSO extract was derived from leaves, and its antioxidant activity was evaluated through the use of the 2,2-diphenyl-1-picryl hydrazyl (DPPH) assay, hydroxyl radical scavenging assay (H2O2 assay), and ferric reducing antioxidant power (FRAP) assay. The anti-inflammatory activity was assessed using the Bovine serum albumin (BSA) denaturation assay, egg albumin (EA) denaturation assay, and membrane stabilization assays. The antimicrobial activity was analyzed using the agar well diffusion technique and the time-kill curve assay. Results In DPPH and H2O2 tests, the DMSO extract of A. calamus showed significant antioxidant activity, near that ofstandard ascorbic acid. The FRAP assay demonstrated a correlation between the dose and the activity of reducing ferric ions. The A. calamusDMSO extract exhibited significant anti-inflammatory properties in BSA and EA denaturation assays, similar to the standard diclofenac sodium. The anti-inflammatory potential of the A. calamus DMSO extract was further confirmed through the membrane stabilization assay. The DMSO extract of A. calamus exhibited a significant inhibition zone against the pathogens Streptococcus mutans and Pseudomonas aeruginosa during the antimicrobial evaluation, surpassing the efficacy of the standard antibiotic. The time-kill curve assay validated the antibacterial efficacy, which was dependent on the concentration. Conclusion The A. calamus DMSO extract exhibited promising antioxidant, anti-inflammatory, and antimicrobial properties, supporting its traditional use in alternative medicine. The findings suggest its potential as a natural resource of compounds with bioactive properties for use in pharmaceutical and nutraceutical applications.

In vitro Study of the Synergistic Effect of Different Concentrations of Chlorhexidine Mouthwash and Ethanolic Extract of Pinus Gerardiana on Oral Pathogens (Streptococcus Mutans and Candida Albicans)

Introduction: Tooth decay is the most common chronic disease in the world. Streptococcus mutans is the most important bacteria that cause tooth decay. The most common chemical method to prevent tooth decay is using mouthwash. Chlorhexidine is used as a standard mouthwash. The use of herbal compounds with antibacterial effect is preferable to chlorhexidine due to less side effects. The purpose of this study was to investigate the combination of different concentrations of chlorhexidine mouthwash and ethanol extract of Pinus gerardiana medicinal plant on oral pathogens (Streptococcus mutans and Candida albicans). Method: A combination of different concentrations of chlorhexidine mouthwash and ethanol extract of Pinus gerardiana medicinal plant was prepared and its effect in different dilution against Streptococcus mutans and Candida albicans was investigated by disc diffusion, well diffusion, and prevention of biofilm formation methods. Results: The results of disc diffusion, well diffusion, and biofilm method showed that the ethanolic extract of Pinus gerardiana medicinal plant alone had no significant antimicrobial effect on Streptococcus mutans and Candida albicans and it was not comparable to chlorhexidine. Conclusion: According to the findings of this study, the antibacterial and antifungal effects of chlorhexidine gradually increased with the increase in concentration, and 0.2% chlorhexidine had the highest inhibitory effect on bacteria and fungi under the present study.

Biosynthesis of Silver Nanoparticles From Marine Actinobacterium Micromonospora sp. and Their Bioactive Potential.

Background The biosynthesis of nanoparticles represents a rapid, environmentally friendly, cost-effective, and straightforward technology. This approach allows for the production of nanoparticles with a wide range of chemical compositions, sizes, shapes, high uniformity, and scalability. One of the principal advantages of biogenic nanoparticles is their water solubility and compatibility with biological systems. Biologically synthesized nanoparticles have demonstrated superior efficiency compared to conventionally synthesized particles. Among biosynthesis, microbial-mediated biosynthesis is a promising one that has a selectively reducing ability on specific metal ions through electron transfer. Objectives Evaluation of antimicrobial and antioxidant activity of silver nanoparticle synthesized by actinobacteria Micromonospora sp. which is isolated from marine environment. Materials and methods In this study, actinobacteria were isolated from the marine sediment using the spread plate method. The isolates were identified based on morphological observation, cell wall amino acids, sugar analysis, and micromorphological analysis. The silver nanoparticle synthesis from microbes and their inhibition against clinical pathogens have been evaluated by the disc diffusion method.Antioxidant efficiency was evaluated in termsof total antioxidant activity through ammonium molybdenum assay. Results A total of five isolates were isolated from the sediment sample. The cell-free extract of MBIT-MSA4 can synthesize silver nanoparticles that have potential antimicrobial activity against the clinical pathogens Streptococcus mutans at a zone of inhibition 6 mm, 10 mm inhibition zone of Klebsiella pneumonia,and 8 mm zone of inhibition of Staphylococcus aureus. Also, it has significant antioxidant activity up to 73% of free radical inhibition. Conclusion Marine microbial-mediated biosynthesized silver nanoparticles have potential antimicrobial activity against S.mutansand methicillin-resistantStaphylococcus aureus(MRSA) and inhibit the oxidation process through antioxidant activity. Thisenhanced efficient biosynthesisednanoparticle has significantly reduced the concentration of free radicals caused by pathogens.

Effect of peanut stilbenoids, arachidin-1 and arachidin-3, on Streptococcus mutans growth and acid production

In this study we evaluated the effect of prenylated peanut stilbenoids on the growth, biofilm accumulation and acid production of the dental caries pathogen Streptococcus mutans. Prior research with the non-prenylated stilbenes, resveratrol and piceatannol, has shown that these molecules are active against S. mutans. Here we sought to determine if the addition of a prenyl group to the stilbene backbone increased anti-S. mutans activities. Two prenylated stilbenes, arachidin-1 and arachidin-3, were produced using a peanut hairy root production system. Compared to resveratrol and piceatannol, both arachidin-1 and arachidin-3 led to greater inhibition of S. mutans planktonic growth. This effect also led to reduced biofilm formation, by inhibiting growth, instead of a specific action against biofilm cells. Lastly, sub-MIC concentrations of arachidin-3 reduced the acid production of S. mutans above the ‘critical pH’ that leads to tooth enamel erosion. In summary, stilbenoids have anti-S. mutans activity, and prenylation enhances this activity.

Capsaicin Shows Species and Strain-specific Activity: Investigation of the Antibacterial Effects on the Oral Pathogen Streptococcus mutans and the Oral Probiotics Streptococcus salivarius M18 and K12

Extensive research has investigated capsaicin (CAP), the primary bioactive compound in chili peppers, to explore its diverse pharmacological and physiological properties. Recently, the focus has shifted to understanding the potential effects of CAP on gut microbiota due to the strong link between gut bacterial profile and diet. However, there has been no research on the effects of CAP on oral microbiota. Therefore, our study aimed to explore the antibacterial effects of CAP on two oral probiotics, Streptococcus salivarius M18, and S. salivarius K12, along with the oral pathogen S. mutans. Previously, the anti-cancer activity of CAP had been demonstrated, and in accordance with these findings, here, we show its growth inhibitory activity on colorectal cancer cell lines. However, this study is the first to examine the impact of CAP on specific oral microorganisms while considering the oral consumption of CAP and the interconnectedness of the oral and gut microbiomes. The findings revealed that CAP exhibited antibacterial properties against the M18 strain at concentrations exceeding 100 µg/mL. Surprisingly, it did not show any growth-inhibitory effects on S. salivarius K12, even at a concentration of 2 mg/mL. Similarly, CAP did not inhibit the growth of S. mutans, a significant factor in dental caries. These results suggest that CAP's effects are species and strain-specific, indicating potential changes in the oral microbiota upon CAP consumption.

Antimicrobial properties of copper tetraamine fluoride.

A stable copper tetraamine fluoride (CTF) with low cytotoxicity has been developed for dental use. To investigate the antimicrobial effects of CTF against common microbes associated with dental caries and periodontal disease. The minimum inhibitory concentrations (MIC) and minimum bactericidal/fungicidal concentrations (MBC/MFC) were used to evaluate the antimicrobial effects of CTF against eight common bacteria and one fungus associated with dental caries and periodontal disease. These nine microbes included cariogenic pathogens (Streptococcus mutans, Streptococcus sobrinus, Lactobacillus acidophilus, Lacticaseibacillus casei, Actinomyces naeslundii and Candida albicans), pulpitis-related bacteria (Enterococcus faecalis) and periodontal disease-related bacteria (Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans). Transmission electron microscopy (TEM) was employed to examine the morphological changes of microbes with and without CTF treatment. The MIC of CTF against nine microbes ranged from 80 ppm (Lacticaseibacillus casei) to 640 ppm (Candida albicans and Enterococcus faecalis). The MBC/MFC ranged from 320 ppm (Lacticaseibacillus casei) to 2560 ppm (Candida albicans). TEM revealed abnormal curvature of cell membranes, disrupted cell membranes, cytoplasmic clear zone, and cytoplasmic content leakage of the microbes treated with CTF. CTF has antimicrobial effects against common oral pathogens and presents a promising antimicrobial agent to aid management of dental caries and periodontal disease.

Measurement and analysis of microbial fluoride resistance in dental biofilm models.

The interactions between communities of microorganisms inhabiting the dental biofilm is a major determinant of oral health. These biofilms are periodically exposed to high concentrations of fluoride, which is present in almost all oral healthcare products. The microbes resist fluoride through the action of membrane export proteins. This chapter describes the culture, growth and harvest conditions of model three-species dental biofilm comprised of cariogenic pathogens Streptococcus mutans and Candida albicans and the commensal bacterium Streptococcus gordonii. In order to examine the role of fluoride export by S. mutans in model biofilms, procedures for generating a strain of S. mutans with a genetic knockout of the fluoride exporter are described. We present a case study examining the effects of this mutant strain on the biofilm mass, acid production and mineral dissolution under exposure to low levels of fluoride. These general approaches can be applied to study the effects of any gene of interest in physiologically realistic multispecies oral biofilms.

Purification, Characterization and Antimicrobial Properties of Hemolymph Lectin from the Larva of Red Palm Weevil, Rhynchophorus ferrugineus

Lectins are renowned hemagglutinins and multivalent proteins with a well-known quality for sugar-binding specificity that participate significantly in invertebrate defense functions. Studies on biological activity of lectin from coleopteran insect are very scarce. A lectin with specific affinity for N-acetyl neuraminic acid was purified from the hemolymph of the larva of the red palm weevil, Rhynchophorus ferrugineus by biospecific adsorption using formalinized rabbit erythrocytes and affinity chromatography using PSM-linked cyanogen bromide activated Sepharose 4B. The specific activity of the lectin purified by affinity chromatography was much higher than the lectin purified by biospecific adsorption. The binding specificity of the weevil lectin distinguishes it from other known insect lectins. Like the crude agglutinin, the lectin purified by affinity chromatography also showed the same pattern of specificity towards erythrocytes. However, 4-to-8-fold decrease in HA titer was observed when tested with the purified lectin. In the same way, reduction is also observed in the HAI titer of the purified lectin with most of the inhibitors except PSM where the HAI titer was identical both in the crude agglutinin and purified lectin. Sugars N-acetyl neuraminic acid, N-acetyl mannosamine and N-acetyl-D-galactosamine inhibited the HA titer of the purified lectin with greater efficacy than the crude agglutinin. The sialic acid specificity of the lectin was confirmed by 16-fold reduction in HA titer with asialo rabbit erythrocytes and 32-fold reduction in HAI titer with desialylated PSM. The purified lectin is homogenous on sodium dodecyl sulphate-polyacrylamide electrophorogram with a molecular weight of about 60 kDa. The lectin showed antimicrobial activity against pathogenic bacteria Streptococcus mutans, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeroginosa and fungi Candida albicans and Aspergillus niger.

Green synthesis of TiO2 nanoparticles using Terminalia chebula and its potent antibiofilm activity against dental caries-associated bacterium Streptococcus mutans

The production of eco-friendly nanoparticles with biocompatible properties is gaining prominence in global medical research. In this study, we explore the antibiofilm potential of Titanium dioxide nanoparticles (TiO2NPs) synthesized from Terminalia chebula against the oral pathogen Streptococcus mutans. Characterization of TiO2NPs revealed a UV–Vis peak at 322 nm. FT-IR spectrum identified Ti–O–Ti vibrations, hydroxyl, and carboxylic groups. SEM analysis revealed tetragonal TiO2NPs, with EDX confirming titanium. XRD confirmed TiO2 anatase crystallographic planes at 25.8° with an average grain size of the particle of 56 nm. Biofilm inhibitory activity indicated significant inhibition of biofilm with BIC50 of 65.71 μg/ml. Microscopic visualization substantiated the efficiency of TiO2NPs in impeding biofilm formation. Increased TiO2NPs concentrations showed a marked reduction in exopolysaccharide and increased protein leakage from S. mutans after prolonged exposure. These findings suggest TiO2NPs as potential agents for treating dental caries, though further validation is needed for therapeutic use in oral care.