.Nijampatnam, Bhavitavya; Casals, Luke; Zheng, Ruowen; Wu, Hui; Velu, Sadanandan E2016-08-01Streptococcus mutans has been implicated as the major etiological agent in the initiation and the development of dental caries due to its robust capacity to form tenacious biofilms. Ideal therapeutics for this disease will aim to selectively inhibit the biofilm formation process while preserving the natural bacterial flora of the mouth. Several studies have demonstrated the efficacies of flavonols on S. Mutans biofilms and have suggested the mechanism of action through their effect on S. Mutans glucosyltransferases (Gtfs). These enzymes metabolize sucrose into water insoluble and soluble glucans, which are an integral measure of the dental caries pathogenesis.
Numerous studies have shown that flavonols and polyphenols can inhibit Gtf and biofilm formation at millimolar concentrations. We have screened a group of 14 hydroxychalcones, synthetic precursors of flavonols, in an S. Mutans biofilm assay.
Several of these compounds emerged to be biofilm inhibitors at low micro-molar concentrations. Chalcones that contained a 3-OH group on ring A exhibited selectivity for biofilm inhibition. Moreover, we synthesized 6 additional analogs of the lead compound and evaluated their potential activity and selectivity against S. Mutans biofilms. The most active compound identified from these studies had an IC50 value of 44μM against biofilm and MIC50 value of 468μM against growth displaying 10-fold selectivity inhibition towards biofilm. The lead compound displayed a dose dependent inhibition of S.
The lead compound also did not affect the growth of two commensal species ( Streptococcus sanguinis and Streptococcus gordonii) at least up to 200μM, indicating that it can selectively inhibit cariogenic biofilms, while leaving commensal and/or beneficial microbes intact. Thus non-toxic compounds have the potential utility in public oral health regimes. Copyright © 2016. Published by Elsevier Ltd.Perry, Dennis; Kuramitsu, Howard K.1981-01-01Three strains of Streptococcus mutans belonging to serotypes a, c, and f were transformed to streptomycin resistance by deoxyribonucleic acids derived from homologous and heterologous streptomycin-resistant strains of S. Mutans and Streptococcus sanguis strain Challis. Homologous transformation of S. Mutans was less efficient than heterologous transformation by deoxyribonucleic acids from other strains of S.
Mutans.193512/715242 Final Report U VIRULENCE FACTORS OF STREPTOCOCCUS MUTANS U Samuel Rosen Department of Oral Biology For the Period April 1, 1983 - June 30.00 FINAL REPORT VIRULENCE FACTORS OF STREPTOCOCCUS MUTANS Sam Rosen, Irving Shklair, E. Beck Ohio State University Columbus,Oh and.206-212.
Johnson CP, Gorss S, Hillman JD (1978). Cariogenic properties of LDH deficient mutants of streptococcus mutans. J Dent Res 57, Special Issue.Deng, D.M.; Hoogenkamp, M.A.; ten Cate, J.M.; Crielaard, W.2009-01-01Antimicrobial resistance of micro-organisms in biofilms requires novel strategies to evaluate the efficacy of caries preventive agents in actual biofilms. Hence we investigated fluorescence intensity (FI) in Streptococcus mutans biofilms constitutively expressing green fluorescent protein (GFP).Wang, Bing-Yan; Kuramitsu, Howard K.2005-01-01Streptococcus mutans has been recognized as an important etiological agent in human dental caries.
May 06, 2013 Pembalut wanita anion paling bagus memiliki sedikit manfaat dan paling jelek adalah berpengaruh negatif. Saudari Lita di: Mitos Ion Negatif dan Pembalut Sehat telah membahasnya cukup mendalam dan saya rekomendasikan untuk mempelajarinya lebih lanjut di sana termasuk diskusinya, atau lewat referensi di bawah, atau kenapa tidak anda beli. Alkohol merupakan senyawa yang penting dalam kehidupan sehari-hari karena dapat digunakan sebagai zat pembunuh kuman, bahan bakar maupun pelarut. Dalam laboratorium dan industri alkohol digunakan sebagai pelarut dan reagensia. Alkohol dapat membentuk ikatan hidrogen antara molekul-molekulnya maupun dengan air.
Some strains of S. Mutans also produce bacteriocins. In this study, we sought to demonstrate that bacteriocin production by S.
Mutans strains GS5 and BM71 was mediated by quorum sensing, which is dependent on a competence-stimulating peptide (CSP) signaling system encoded by the com genes. We also demonstrated that interactions with some other oral streptococci interfered with S. Mutans bacterio.Zeng, Huihui; Liu, Jia; Ling, Junqi2017-04-01It is well established that efflux pumps play important roles in bacterial pathogenicity and efflux inhibitors (EIs) have been proved to be effective in suppressing bacterial virulence properties. However, little is known regarding the EI of Streptococcus mutans, a well-known caries-inducing bacterium. In this study, we identified the EI of S.
Mutans through ethidium bromide efflux assay and investigated how EI affected S. Mutans virulence regarding the cariogenicity and stress response. Results indicated that reserpine, the identified EI, suppressed acid tolerance, mutacin production and transformation efficiency of S. Mutans, and modified biofilm architecture and extracellular polysaccharide distribution. Suppressed glycosyltransferase activity was also noted after reserpine exposure. The data from quantitative real-time-PCR demonstrated that reserpine significantly altered the expression profile of quorum-sensing and virulence-associated genes.
These findings suggest that reserpine represents a promising adjunct anticariogenic agent in that it suppresses virulence properties of S. All rights reserved. For permissions, please e-mail: [email protected], Bing-Yan; Kuramitsu, Howard K2005-01-01Streptococcus mutans has been recognized as an important etiological agent in human dental caries. Some strains of S. Mutans also produce bacteriocins. In this study, we sought to demonstrate that bacteriocin production by S. Mutans strains GS5 and BM71 was mediated by quorum sensing, which is dependent on a competence-stimulating peptide (CSP) signaling system encoded by the com genes.
We also demonstrated that interactions with some other oral streptococci interfered with S. Mutans bacteriocin production both in broth and in biofilms.
The inhibition of S. Mutans bacteriocin production by oral bacteria was stronger in biofilms than in broth. Using transposon Tn916 mutagenesis, we identified a gene (sgc; named for Streptococcus gordonii challisin) responsible for the inhibition of S.
Mutans bacteriocin production by S. Gordonii Challis. Interruption of the sgc gene in S. Gordonii Challis resulted in attenuated inhibition of S. Mutans bacteriocin production.
The supernatant fluids from the sgc mutant did not inactivate the exogenous S. Mutans CSP as did those from the parent strain Challis. Gordonii Challis did not inactivate bacteriocin produced by S. Mutans uses quorum sensing to regulate virulence, strategies designed to interfere with these signaling systems may have broad applicability for biological control of this caries-causing organism.Ahn, Ki Bum; Baik, Jung Eun; Park, Ok-Jin; Yun, Cheol-Heui2018-01-01Dental caries is a biofilm-dependent oral disease and Streptococcus mutans is the known primary etiologic agent of dental caries that initiates biofilm formation on tooth surfaces. Although some Lactobacillus strains inhibit biofilm formation of oral pathogenic bacteria, the molecular mechanisms by which lactobacilli inhibit bacterial biofilm formation are not clearly understood. In this study, we demonstrated that Lactobacillus plantarum lipoteichoic acid (Lp.LTA) inhibited the biofilm formation of S. Mutans on polystyrene plates, hydroxyapatite discs, and dentin slices without affecting the bacterial growth.
Lp.LTA interferes with sucrose decomposition of S. Mutans required for the production of exopolysaccharide, which is a main component of biofilm. Lp.LTA also attenuated the biding of fluorescein isothiocyanate-conjugated dextran to S. Mutans, which is known to have a high affinity to exopolysaccharide on S.
Dealanylated Lp.LTA did not inhibit biofilm formation of S. Mutans implying that D-alanine moieties in the Lp.LTA structure were crucial for inhibition. Collectively, these results suggest that Lp.LTA attenuates S. Mutans biofilm formation and could be used to develop effective anticaries agents. PMID:29420616.Bao, X.; de Soet, J.J.; Tong, H.; Gao, X.; He, L.; van Loveren, C.; Deng, D.M.2015-01-01Homeostasis of oral microbiota can be maintained through microbial interactions. Previous studies showed that Streptococcus oligofermentans, a non- mutans streptococci frequently isolated from caries-free subjects, inhibited the cariogenic Streptococcus mutans by the production of hydrogen peroxide.Huang, Xuelian; Palmer, Sara R; Ahn, Sang-Joon; Richards, Vincent P; Williams, Matthew L; Nascimento, Marcelle M; Burne, Robert A2016-01-29The ability of certain oral biofilm bacteria to moderate pH through arginine metabolism by the arginine deiminase system (ADS) is a deterrent to the development of dental caries. Here, we characterize a novel Streptococcus strain, designated strain A12, isolated from supragingival dental plaque of a caries-free individual.
A12 not only expressed the ADS pathway at high levels under a variety of conditions but also effectively inhibited growth and two intercellular signaling pathways of the dental caries pathogen Streptococcus mutans. A12 produced copious amounts of H2O2 via the pyruvate oxidase enzyme that were sufficient to arrest the growth of S. A12 also produced a protease similar to challisin (Sgc) of Streptococcus gordonii that was able to block the competence-stimulating peptide (CSP)-ComDE signaling system, which is essential for bacteriocin production by S.
Wild-type A12, but not an sgc mutant derivative, could protect the sensitive indicator strain Streptococcus sanguinis SK150 from killing by the bacteriocins of S. A12, but not S. Gordonii, could also block the XIP (comX-inducing peptide) signaling pathway, which is the proximal regulator of genetic competence in S.
Mutans, but Sgc was not required for this activity. The complete genome sequence of A12 was determined, and phylogenomic analyses compared A12 to streptococcal reference genomes.
A12 was most similar to Streptococcus australis and Streptococcus parasanguinis but sufficiently different that it may represent a new species. A12-like organisms may play crucial roles in the promotion of stable, health-associated oral biofilm communities by moderating plaque pH and interfering with the growth and virulence of caries pathogens. Copyright © 2016, American Society for Microbiology. All Rights Reserved.Stoesser, L.; Kneist, S.; Tumovec, M.; Katzmann, M.1988-01-01The growth kinetic parameters of S. Mutans OMZ 176 culture as well as the 32 PO 4 uptake, as a measure of living cell mass, and the acid production rate by germ suspensions in a pH-stat technique were estimated.
Subsequently, the acidogenicity of 20 S. Mutans strains, other oral streptococci and dental plaque was measured and compared taking into consideration the growth kinetic dependence of studied activities. The strains OMZ 176 and OMZ 65 exhibited the most acidogenic properties whereas FA 1 produced 3.6 times less acid. (author).Oli, M.
N.; Crowley, P. P.; Nascimento, M. M.; Ramsook, C. B.; Lipke, P. N.2012-01-01Dental caries is a common infectious disease associated with acidogenic and aciduric bacteria, including Streptococcus mutans.
Organisms that cause cavities form recalcitrant biofilms, generate acids from dietary sugars and tolerate acid end products. It has recently been recognized that micro-organisms can produce functional amyloids that are integral to biofilm development. We now show that the S. Mutans cell-surface-localized adhesin P1 (antigen I/II, PAc) is an amyloid-forming protein.
This conclusion is based on the defining properties of amyloids, including binding by the amyloidophilic dyes Congo red (CR) and Thioflavin T (ThT), visualization of amyloid fibres by transmission electron microscopy and the green birefringent properties of CR-stained protein aggregates when viewed under cross-polarized light. We provide evidence that amyloid is present in human dental plaque and is produced by both laboratory strains and clinical isolates of S. We provide further evidence that amyloid formation is not limited to P1, since bacterial colonies without this adhesin demonstrate residual green birefringence. Mutans lacking sortase, the transpeptidase enzyme that mediates the covalent linkage of its substrates to the cell-wall peptidoglycan, including P1 and five other proteins, is not birefringent when stained with CR and does not form biofilms. Biofilm formation is inhibited when S. Mutans is cultured in the presence of known inhibitors of amyloid fibrillization, including CR, Thioflavin S and epigallocatechin-3-gallate, which also inhibited ThT uptake by S. Mutans extracellular proteins.
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Taken together, these results indicate that S. Mutans is an amyloid-forming organism and suggest that amyloidogenesis contributes to biofilm formation by this oral microbe. PMID:23082034.Ahn, Ki Dong; Kim, Gyu Tae; Choi, Yong Suk; Hwang, Eui Hwan2007-01-01To observe direct effect of irradiation on cariogenic Streptococcus mutans.
Mutans GS5 was exposed to irradiation with a single absorbed dose of 10, 20, 30, and 40 Gy. Viability and changes in antibiotic sensitivity, morphology, transcription of virulence factors, and protein profile of bacterium after irradiation were examined by pour plate, disc diffusion method, Transmission electron microscopy.
RT-PCR, and SDS-PAGE, respectively. After irradiation with 10 and 20 Gy, viability of S. Mutans was reduced. Further increase in irradiation dose, however, did not affect the viability of the remaining cells of S. Irradiated S. Mutans was found to have become sensitive to antibiotics.
In particular, the bacterium irradiated with 40 Gy increased its susceptibility to cefotaxime, penicillin, and tetracycline. Under the transmission electron microscope, number of morphologically abnormal cells was increased as the irradiation dose was increased. Mutans irradiated with 10 Gy revealed a change in the cell wall and cell membrane. As irradiation dose was increased. A higher number of cells showed thickened cell wall and cell membrane and lysis, and appearance of ghost cells was noticeable.
In RT-PCR, no difference was detected in expression of gtfB and spaP between cells with and without irradiation of 40 Gy. In SDS-PAGE, proteins with higher molecular masses were gradually diminished as irradiation dose was increased. These results suggest that irradiation affects the cell integrity of S. Mutans, as observed by SDS-PAGE, and as manifested by the change in cell morphology, antibiotic sensitivity, and eventually viability of the bacterium.Ahn, Ki Dong; Kim, Gyu Tae; Choi, Yong Suk; Hwang, Eui Hwan Kyung Hee Univ., Seoul (Korea, Republic of)2007-03-15To observe direct effect of irradiation on cariogenic Streptococcus mutans. Mutans GS5 was exposed to irradiation with a single absorbed dose of 10, 20, 30, and 40 Gy. Viability and changes in antibiotic sensitivity, morphology, transcription of virulence factors, and protein profile of bacterium after irradiation were examined by pour plate, disc diffusion method, Transmission electron microscopy.
RT-PCR, and SDS-PAGE, respectively. After irradiation with 10 and 20 Gy, viability of S. Mutans was reduced.
Further increase in irradiation dose, however, did not affect the viability of the remaining cells of S. Irradiated S.
Mutans was found to have become sensitive to antibiotics. In particular, the bacterium irradiated with 40 Gy increased its susceptibility to cefotaxime, penicillin, and tetracycline.
Under the transmission electron microscope, number of morphologically abnormal cells was increased as the irradiation dose was increased. Mutans irradiated with 10 Gy revealed a change in the cell wall and cell membrane. As irradiation dose was increased. A higher number of cells showed thickened cell wall and cell membrane and lysis, and appearance of ghost cells was noticeable. In RT-PCR, no difference was detected in expression of gtfB and spaP between cells with and without irradiation of 40 Gy. In SDS-PAGE, proteins with higher molecular masses were gradually diminished as irradiation dose was increased.
These results suggest that irradiation affects the cell integrity of S. Mutans, as observed by SDS-PAGE, and as manifested by the change in cell morphology, antibiotic sensitivity, and eventually viability of the bacterium.Michiyo Matsumoto-Nakano2018-02-01Full Text Available Summary: Streptococcus mutans has been implicated as a primary causative agent of dental caries in humans. An important virulence property of the bacterium is its ability to form biofilm known as dental plaque on tooth surfaces. In addition, this organism also produces glucosyltransferases, multiple glucan-binding proteins, protein antigen c, and collagen-binding protein, surface proteins that coordinate to produce dental plaque, thus inducing dental caries.
Bacteria utilize quorum-sensing systems to modulate environmental stress responses. A major mechanism of response to signals is represented by the so called two-component signal transduction system, which enables bacteria to regulate their gene expression and coordinate activities in response to environmental stress. Mutans, a signal peptide-mediated quorum-sensing system encoded by comCDE has been found to be a regulatory system that responds to cell density and certain environmental stresses by excreting a peptide signal molecule termed CSP (competence-stimulating peptide. One of its principal virulence factors is production of bacteriocins (peptide antibiotics referred to as mutacins. Two-component signal transduction systems are commonly utilized by bacteria to regulate bacteriocin gene expression and are also related to biofilm formation by S. Keywords: Streptococcus mutans, Surface proteins, Biofilm, Signal transduction.Hoogenkamp, M.A.; Crielaard, W.; ten Cate, J.M.; Wever, R.; Hartog, A.F.; Renirie, R.2009-01-01The aim of this study was to investigate the antimicrobial activity of vanadium chloroperoxidase (VCPO) reaction products on planktonic and biofilm cellsof Streptococcus mutans C180-2.
Planktonic and biofilm cells were incubated in a buffered reaction mixture containing VCPO, halide (either chloride.Jarosz, Lucja M; Deng, Dong Mei; van der Mei, Henny C; Crielaard, Wim; Krom, Bastiaan P2009-11-01The oral cavity is colonized by microorganisms growing in biofilms in which interspecies interactions take place. Streptococcus mutans grows in biofilms on enamel surfaces and is considered one of the main etiological agents of human dental caries. Candida albicans is also commonly found in the human oral cavity, where it interacts with S.
Albicans is a polymorphic fungus, and the yeast-to-hypha transition is involved in virulence and biofilm formation. The aim of this study was to investigate interkingdom communication between C. Albicans and S. Mutans based on the production of secreted molecules. Mutans UA159 inhibited C. Albicans germ tube (GT) formation in cocultures even when physically separated from C.
Mutans spent medium collected in the early exponential phase (4-h-old cultures) inhibited the GT formation of C. During this phase, S. Mutans UA159 produces a quorum-sensing molecule, competence-stimulating peptide (CSP). The role of CSP in inhibiting GT formation was confirmed by using synthetic CSP and a comC deletion strain of S. Mutans UA159, which lacks the ability to produce CSP. Mutans strains and other Streptococcus spp.
Also inhibited GT formation but to different extents, possibly reflecting differences in CSP amino acid sequences among Streptococcus spp. Or differences in CSP accumulation in the media. In conclusion, CSP, an S. Mutans quorum-sensing molecule secreted during the early stages of growth, inhibits the C.
Albicans morphological switch.Liao, Ying2017-01-01Fluoride has been used as the most effective anti-caries agent for over five decades. It functions not only on the dental hard tissues, but also as an antimicrobial agent. It is known that oral bacteria are able to develop resistance to fluoride, which may affect the effectiveness of fluoride in.Branting, C.; Linder, L.E.; Sund, M.-L.; Oden, A.; Wiatr-Adamczak, E.1988-01-01The adhesion of Streptococcus rattus BHT and Streptococcus mutans IB to metal specimens of amalgam, silver, tin and copper was studied using (6- 3 H) thymidine labeled cells. In the standard assay the metal specimens were suspended by a nylon thread in an adhesion solution containing a chemically defined bacterial growth medium (FMC), sucrose, and radiolabeled bacteria.
Maximum amounts of adhering bacteria were obtained after about 100 min of incubation. Saturation of the metal specimens with bacteria was not observed. Both strains also adhered in the absence of sucrose, indicating that glucan formation was not necessary for adhesion.
However, in the presence of glucose, adhesion was only 26-45% of that observed in the presence of equimolar sucrose. Sucrose-dependent stimulation of adhesion seemed to be due to increased cell-to-cell adhesion capacity.
Isolated radiolabeled water-insoluble and water-soluble polysaccharides produced from sucrose by S. Rattus BHT were not adsorbed to the metal surfaces. (author).Branting, C.; Linder, L.E.; Sund, M.-L.; Oden, A.; Wiatr-Adamczak, E.1988-01-01The adhesion of Streptococcus rattus BHT and Streptococcus mutans IB to metal specimens of amalgam, silver, tin and copper was studied using (6-/sup 3/H) thymidine labeled cells. In the standard assay the metal specimens were suspended by a nylon thread in an adhesion solution containing a chemically defined bacterial growth medium (FMC), sucrose, and radiolabeled bacteria.
Maximum amounts of adhering bacteria were obtained after about 100 min of incubation. Saturation of the metal specimens with bacteria was not observed. Both strains also adhered in the absence of sucrose, indicating that glucan formation was not necessary for adhesion. However, in the presence of glucose, adhesion was only 26-45% of that observed in the presence of equimolar sucrose. Sucrose-dependent stimulation of adhesion seemed to be due to increased cell-to-cell adhesion capacity. Isolated radiolabeled water-insoluble and water-soluble polysaccharides produced from sucrose by S. Rattus BHT were not adsorbed to the metal surfaces.Telma Blanca Lombardo BedranFull Text Available Triclosan is a general membrane-active agent with a broad-spectrum antimicrobial activity that is commonly used in oral care products.
In this study, we investigated the effect of sub-minimum inhibitory concentrations (MICs of triclosan on the capacity of the cariogenic bacterium Streptococcus mutans to form biofilm and adhere to oral epithelial cells. As quantified by crystal violet staining, biofilm formation by two reference strains of S. Mutans was dose-dependently promoted, in the range of 2.2- to 6.2-fold, by 1/2 and 1/4 MIC of triclosan. Observations by scanning electron microscopy revealed the presence of a dense biofilm attached to the polystyrene surface. Mutans in the presence of triclosan at sub-MICs also increased its capacity to adhere to a monolayer of gingival epithelial cells. The expression of several genes involved in adherence and biofilm formation in S. Mutans was investigated by quantitative RT-PCR.
It was found that sub-MICs of triclosan significantly increased the expression of comD, gtfC, and luxS, and to a lesser extent of gtfB and atlA genes. These findings stress the importance of maintaining effective bactericidal concentrations of therapeutic triclosan since sub-MICs may promote colonization of the oral cavity by S.
Mutans.Liu, Ying; Zhang, Xiangyu; Wang, Yuzhi; Chen, Feifei; Yu, Zhifen; Wang, Li; Chen, Shuanglu; Guo, Maoding2013-07-01In order to exploit novel anticaries agents, we investigated the effects of citrus lemon oil (CLO), a type of natural product, on growth and adherence of the primary oral cariogenic bacteria Streptococcus mutans (S. The growth inhibitory effect was explored with a micro-dilution assay. Adherence was analyzed by colony counts on the respective surfaces and the adherence inhibition rate (AIR). Real time-PCR was used to investigate the effects of CLO on transcription of glucosyltransferase (Gtf) encoding genes, gtfB, C and D. Neson-Somogyi method was used to measure the effects of CLO on Gtf activity. The minimum inhibitory concentration of CLO against S. Mutans was 4.5 mg/ml.
The CLO effectively reduced the adherence of S. Mutans on glass surface (the AIR were from 98.3 to 100%, P 0.05) and saliva-coated enamel surface (the AIR were from 54.8 to 79.2%, P.Moye, Zachary D; Son, Minjun; Rosa-Alberty, Ariana E; Zeng, Lin; Ahn, Sang-Joon; Hagen, Stephen J; Burne, Robert A2016-08-01The capacity to internalize and catabolize carbohydrates is essential for dental caries pathogens to persist and cause disease. The expression of many virulence-related attributes by Streptococcus mutans, an organism strongly associated with human dental caries, is influenced by the peptide signaling pathways that control genetic competence. Here, we demonstrate a relationship between the efficiency of competence signaling and carbohydrate source. A significant increase in the activity of the promoters for comX, comS, and comYA after exposure to competence-stimulating peptide (CSP) was observed in cells growing on fructose, maltose, sucrose, or trehalose as the primary carbohydrate source, compared to cells growing on glucose.
However, only cells grown in the presence of trehalose or sucrose displayed a significant increase in transformation frequency. Notably, even low concentrations of these carbohydrates in the presence of excess glucose could enhance the expression of comX, encoding a sigma factor needed for competence, and the effects on competence were dependent on the cognate sugar:phosphotransferase permease for each carbohydrate. Using green fluorescent protein (GFP) reporter fusions, we observed that growth in fructose or trehalose resulted in a greater proportion of the population activating expression of comX and comS, encoding the precursor of comX-inducing peptide (XIP), after addition of CSP, than growth in glucose. Thus, the source of carbohydrate significantly impacts the stochastic behaviors that regulate subpopulation responses to CSP, which can induce competence in S. Mutans The signaling pathways that regulate development of genetic competence in Streptococcus mutans are intimately intertwined with the pathogenic potential of the organism, impacting biofilm formation, stress tolerance, and expression of known virulence determinants. Induction of the gene for the master regulator of competence, ComX, by competence-stimulating peptide (CSP.Moye, Zachary D.; Son, Minjun; Rosa-Alberty, Ariana E.; Zeng, Lin; Ahn, Sang-Joon2016-01-01ABSTRACT The capacity to internalize and catabolize carbohydrates is essential for dental caries pathogens to persist and cause disease.
The expression of many virulence-related attributes by Streptococcus mutans, an organism strongly associated with human dental caries, is influenced by the peptide signaling pathways that control genetic competence. Here, we demonstrate a relationship between the efficiency of competence signaling and carbohydrate source. A significant increase in the activity of the promoters for comX, comS, and comYA after exposure to competence-stimulating peptide (CSP) was observed in cells growing on fructose, maltose, sucrose, or trehalose as the primary carbohydrate source, compared to cells growing on glucose. However, only cells grown in the presence of trehalose or sucrose displayed a significant increase in transformation frequency.
Notably, even low concentrations of these carbohydrates in the presence of excess glucose could enhance the expression of comX, encoding a sigma factor needed for competence, and the effects on competence were dependent on the cognate sugar:phosphotransferase permease for each carbohydrate. Using green fluorescent protein (GFP) reporter fusions, we observed that growth in fructose or trehalose resulted in a greater proportion of the population activating expression of comX and comS, encoding the precursor of comX-inducing peptide (XIP), after addition of CSP, than growth in glucose. Thus, the source of carbohydrate significantly impacts the stochastic behaviors that regulate subpopulation responses to CSP, which can induce competence in S. IMPORTANCE The signaling pathways that regulate development of genetic competence in Streptococcus mutans are intimately intertwined with the pathogenic potential of the organism, impacting biofilm formation, stress tolerance, and expression of known virulence determinants. Induction of the gene for the master regulator of competence, ComX, by competence.Aryan Morita2016-06-01Full Text Available Background: Various materials have been used for treating dental caries.
Dental caries is a disease that attacks hard tissues of the teeth. The initial phase of caries is a formation of bacterial biofilm, called as dental plaque. Dental restorative materials are expected for preventing secondary caries formation initiated by dental plaque. Initial bacterial adhesion is assumed to be an important stage of dental plaque formation. Bacteria that recognize the receptor for binding to the pellicle on tooth surface are known as initial bacterial colonies. One of the bacteria that plays a role in the early stage of dental plaque formation is Streptococcus mutans (S.
Artificial mouth system (AMS used in bacterial biofilm research on the oral cavity provides the real condition of oral cavity and continous and intermittent supply of nutrients for bacteria. Purpose: This study aimed to compare the profile of S. Mutans bacterial adhesion as the primary etiologic agent for dental caries between using static method and using artificial mouth system, a dinamic. Method: The study was conducted at Faculty of Dentistry and Integrated Research and testing laboratory (LPPT in Universitas Gadjah Mada from April to August 2015. Composite resin was used as the subject of this research. Twelve composite resins with a diameter of 5 mm and a width of 2 mm were divided into two groups, namely group using static method and group using dynamic method.
Static method was performed by submerging the samples into a 100µl suspension of 1.5 x 108 CFU/ml S. Mutans and 200µl BHI broth. Meanwhile AMS method was carried out by placing the samples at the AMS tube drained with 20 drops/minute of bacterial suspension and sterile aquadest. After 72 hours, five samples from each group were calculated for their biofilm mass using 1% crystal violet and read by a spectrofotometer with a wavelength of 570 nm.
Meanwhile, one sample from each group was taken for its.Rosella Camere-Colarossi; Gabriela Ulloa-Urizar; Dyanne Medina-Flores; Stefany Caballero-Garca; Frank Mayta-Tovalino; Juana del Valle-Mendoza2016-01-01Objective: To evaluate the antibacterial and cytotoxic effect of Myrciaria dubia (Camu camu) (M. Dubia) methanol extract, against Streptococcus mutans (ATCC 25175) (S. Mutans) and Streptococcus sanguinis (ATCC 10556) (S. Methods: Two methanol extracts of M.
Dubia were prepared in vitro, from the seeds and pulp. Ten independent tests were prepared for each type of extract, using 0.12% chlor-hexidine solution as positive control.
Agar diffusion test was used by preparing wells with the experimental solutions cultivated in anaerobic conditions for 48 h at 37 ° C. Mean-while, the minimum inhibitory concentration and the cytotoxic effect over MDCK cell line was found. Results: A higher antibacterial effect was observed with the methanol seed extract with an inhibitory halo of (21.36 ± 6.35) mm and (19.21 ± 5.18) mm against S. Mutans and S. Sanguinis, respectively. The methanol extract of the pulp had an effect of (16.20 ± 2.08) mm and (19.34 ± 2.90) mm, respectively.
The minimum inhibitory concentration of the pulp extract was 62.5μg/mL for both strains, whereas for the seed antibacterial activity was observed even at low concentrations. The CC50 of the seeds extract was at a higher con-centration than 800μg/mL and 524.37μg/mL for the pulp extract. Conclusions: The experimental findings demonstrated the antibacterial effect of the methanol extract of M. Dubia against S. Mutans and S. These extracts were not cytotoxic at high concentrations.Yulita Kristanti2013-12-01Full Text Available Background: Direct contact between the bleaching agent and the enamel surface results in demineralization, alteration in surface roughness and bacterial adhesion. Many studies try to minimize this side effect through different way.
Purpose: The aim of this study was to determined the effect of Calcium Phospho Peptide-Amorphous Calcium Phosphate (CPP-ACP containing fluoride application before and after bleaching procedure on the adhesion of S. Mutans and enamel roughness. Methods: The samples were 6 teeth which were divided into 4 groups, and each tooth was cut into four pieces. Group A and C were treated with CPP-ACP after bleaching, while group B and D were treated with CPP-ACP before and after bleaching. CPP-ACP used in group C and D was the one that contain fluoride. After treatment, all samples were sterilized, immersed in steril human saliva for one hour, then immersed into S.
Mutans suspension of 108 CFU. Samples were incubated overnight.
On the next day the samples were put into steril BHI and vortexed for one minute to detach the bacteria. Fifteen ml BHI containing bacteria was poured into TYS agar then incubated 37°Cfor 48 hours. Bacterial colony was counted with colony counter. The SEM examination was done on all samples. Results: Application of desensitizing agent reduced the S. Mutans adhesion significantly among groups (p.
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