Triclosan inhibition of membrane enzymes and glycolysis of Streptococcus mutans in suspensions and biofilms

2006 ◽  
Vol 52 (10) ◽  
pp. 977-983 ◽  
Author(s):  
Tuan-Nghia Phan ◽  
Robert E Marquis

Triclosan was found to be a potent inhibitor of the F(H+)-ATPase of the oral pathogen Streptococcus mutans and to increase proton permeabilities of intact cells. Moreover, it acted additively with weak-acid transmembrane proton carriers, such as fluoride or sorbate, to sensitize glycolysis to acid inhibition. Even at neutral pH, triclosan could inhibit glycolysis more directly as an irreversible inhibitor of the glycolytic enzymes pyruvate kinase, lactic dehydro genase, aldolase, and the phosphoenolpyruvate:sugar phosphotransferase system (PTS). Cell glycolysis in suspensions or biofilms was inhibited in a pH-dependent manner by triclosan at a concentration of about 0.1 mmol/L at pH 7, approximately the lethal concentration for S. mutans cells in suspensions. Cells in intact biofilms were almost as sensitive to triclosan inhibition of glycolysis as were cells in suspensions but were more resistant to killing. Targets for irreversible inhibition of glycolysis included the PTS and cytoplasmic enzymes, specifically pyruvate kinase, lactic dehydrogenase, and to a lesser extent, aldolase. General conclusions are that triclosan is a multi-target inhibitor for mutans streptococci, which lack a triclosan-sensitive FabI enoyl-ACP reductase, and that inhibition of glycolysis in dental plaque biofilms, in which triclosan is retained after initial or repeated exposure, would reduce cariogenicity.Key words: triclosan, oral streptococci, glycolysis, biofilms, F-ATPase.

2011 ◽  
Vol 57 (3) ◽  
pp. 217-225 ◽  
Author(s):  
Phuong T. M. Nguyen ◽  
Robert E. Marquis

The increasing prevalence of dental caries is making it more of a major world health problem. Caries is the direct result of acid production by cariogenic oral bacteria, especially Streptococcus mutans . New and better antimicrobial agents active against cariogenic bacteria are badly needed, especially natural agents derived directly from plants. We have evaluated the inhibitory actions of α-mangostin, a xanthone purified from ethanolic extracts of the tropical plant Garcinia mangostana L., by repeated silica gel chromatography. α-Mangostin was found to be a potent inhibitor of acid production by S. mutans UA159, active against membrane enzymes, including the F(H+)-ATPase and the phosphoenolpyruvate – sugar phosphotransferase system. α-Mangostin also inhibited the glycolytic enzymes aldolase, glyceraldehyde-3-phosphate dehydrogenase, and lactic dehydrogenase. Glycolysis by intact cells in suspensions or biofilms was inhibited by α-mangostin at concentrations of 12 and 120 µmol·L–1, respectively, in a pH-dependent manner, with greater potency at lower pH values. Other targets for inhibition by α-mangostin included (i) malolactic fermentation, involved in alkali production from malate, and (ii) NADH oxidase, the major respiratory enzyme for S. mutans. The overall conclusion is that α-mangostin is a multitarget inhibitor of mutans streptococci and may be useful as an anticaries agent.


1973 ◽  
Vol 52 (6) ◽  
pp. 1209-1215 ◽  
Author(s):  
Charles F. Schachtele ◽  
John A. Mayo

Streptococcus mutans, S sanguis, and S salivarius use a phosphoenolpyruvate (PEP)-dependent phosphotransferase system that results in phosphorylation of glucose at carbon 6. This enzyme system is not sensitive to fluoride. Glucose uptake into resting cell suspensions is sensitive to fluoride because of inhibition of intracellular PEP production. The glucose phosphotransferase system is constitutive in oral streptococci.


2021 ◽  
pp. 205-214
Author(s):  
Sili Han ◽  
Yuki Abiko ◽  
Jumpei Washio ◽  
Yufang Luo ◽  
Linglin Zhang ◽  
...  

It has been suggested that green tea-derived epigallocatechin gallate (EGCG), which has antimicrobial properties, might help prevent dental caries. However, the detailed properties of EGCG remain unclear. In this study, the antimicrobial properties of EGCG were evaluated by examining its bactericidal activity, its inhibitory effects against bacterial growth, acid production, acidic end-product formation, and sugar uptake (phosphoenolpyruvate-dependent phosphotransferase system, PEP-PTS activity), and its effects on bacterial aggregation, using monocultured planktonic cells of <i>Streptococcus mutans</i> and non-mutans streptococci. Coincubating <i>S. mutans</i> with EGCG (1 mg/mL) for 4 h had no bactericidal effects, while it decreased the growth and acid production of <i>S. mutans</i> by inhibiting the activity of the PEP-PTS. EGCG (2 mg/mL) caused rapid bacterial cell aggregation and had reduced the optical density of <i>S. mutans</i> cell suspension by 86.7% at pH 7.0 and 90.7% at pH 5.5 after 2 h. EGCG also reduced the acid production of non-mutans streptococci, including <i>S. sanguinis</i>, <i>S. gordonii</i>, and <i>S. salivarius</i>, and promoted the aggregation of these non-mutans streptococci. Furthermore, these antimicrobial effects of short-term EGCG treatment persisted in the presence of saliva. These results suggest that EGCG might have short-term antibacterial effects on caries-associated streptococci in the oral cavity.


2006 ◽  
Vol 188 (11) ◽  
pp. 3748-3756 ◽  
Author(s):  
Jacqueline Abranches ◽  
Melissa M. Candella ◽  
Zezhang T. Wen ◽  
Henry V. Baker ◽  
Robert A. Burne

ABSTRACT The phosphoenolpyruvate:sugar phosphotransferase system (PTS) is the major carbohydrate transport system in oral streptococci. The mannose-PTS of Streptococcus mutans, which transports mannose and glucose, is involved in carbon catabolite repression (CCR) and regulates the expression of known virulence genes. In this study, we investigated the role of EIIGlc and EIIABMan in sugar metabolism, gene regulation, biofilm formation, and competence. The results demonstrate that the inactivation of ptsG, encoding a putative EIIGlc, did not lead to major changes in sugar metabolism or affect the phenotypes of interest. However, the loss of EIIGlc was shown to have a significant impact on the proteome and to affect the expression of a known virulence factor, fructan hydrolase (fruA). JAM1, a mutant strain lacking EIIABMan, had an impaired capacity to form biofilms in the presence of glucose and displayed a decreased ability to be transformed with exogenous DNA. Also, the lactose- and cellobiose-PTSs were positively and negatively regulated by EIIABMan, respectively. Microarrays were used to investigate the profound phenotypic changes displayed by JAM1, revealing that EIIABMan of S. mutans has a key regulatory role in energy metabolism, possibly by sensing the energy levels of the cells or the carbohydrate availability and, in response, regulating the activity of transcription factors and carbohydrate transporters.


2003 ◽  
Vol 69 (8) ◽  
pp. 4760-4769 ◽  
Author(s):  
Jacqueline Abranches ◽  
Yi-Ywan M. Chen ◽  
Robert A. Burne

ABSTRACT The phosphoenolpyruvate:sugar phosphotransferase system (PTS) is the major sugar uptake system in oral streptococci. The role of EIIABMan (encoded by manL) in gene regulation and sugar transport was investigated in Streptococcus mutans UA159. The manL knockout strain, JAM1, grew more slowly than the wild-type strain in glucose but grew faster in mannose and did not display diauxic growth, indicating that EIIABMan is involved in sugar uptake and in carbohydrate catabolite repression. PTS assays of JAM1, and of strains lacking the inducible (fruI) and constitutive (fruCD) EII fructose, revealed that S. mutans EIIABMan transported mannose and glucose and provided evidence that there was also a mannose-inducible or glucose-repressible mannose PTS. Additionally, there appears to be a fructose PTS that is different than FruI and FruCD. To determine whether EIIABMan controlled expression of the known virulence genes, glucosyltransferases (gtfBC) and fructosyltransferase (ftf) promoter fusions of these genes were established in the wild-type and EIIABMan-deficient strains. In the manL mutant, the level of chloramphenicol acetyltransferase activity expressed from the gtfBC promoter was up to threefold lower than that seen with the wild-type strain at pH 6 and 7, indicating that EIIABMan is required for optimal expression of gtfBC. No significant differences were observed between the mutant and the wild-type background in ftf regulation, with the exception that under glucose-limiting conditions at pH 7, the mutant exhibited a 2.1-fold increase in ftf expression. Two-dimensional gel analysis of batch-grown cells of the EIIABMan-deficient strain indicated that the expression of at least 38 proteins was altered compared to that seen with the wild-type strain, revealing that EIIABMan has a pleiotropic effect on gene expression.


1984 ◽  
Vol 30 (4) ◽  
pp. 495-502 ◽  
Author(s):  
Christian Vadeboncoeur

The presence of three distinct enzymes II that catalysed the phosphoenolpyruvate-dependent phosphorylation of glucose, fructose, and mannose was established in membranes of glucose-grown cells of Streptococcus salivarius 25975 and various strains of Streptococcus mutans. The enzyme II mannose phosphorylated mainly mannose, glucose, and 2-deoxyglucose, and the enzyme II glucose phosphorylated glucose, α-methylglucoside, and 2-deoxyglucose. The phosphoenolpyruvate-dependent phosphorylation of glucose and α-methylglucoside by isolated membrane of wild-type or EII mannose negative mutant cells did not require the presence of any soluble protein other than enzyme I and the phosphocarrier protein HPr. This result suggested that oral streptococci do not possess a soluble factor III glucose. The enzyme II activities varied as a function of the growth sugar but were not coordinately regulated. The variation elicited by specific sugars was not identical for all the strains tested. Nevertheless, in the case of the S. mutans strains, growth at the expense of lactose always caused a significant decrease in the level of enzyme II activities. Finally, experiments conducted with EII mannose negative mutants and also with a pseudorevertant isolated from one of these mutants indicated that the preferential utilization of glucose over lactose by cells growing in mixtures depended on the presence of the EII mannose, but not on glucose-derived metabolites.


2020 ◽  
Vol 203 (2) ◽  
pp. e00293-20
Author(s):  
Matthew E. Turner ◽  
Khanh Huynh ◽  
Ronan K. Carroll ◽  
Sang-Joon Ahn ◽  
Kelly C. Rice

ABSTRACTStreptococcus mutans utilizes numerous metabolite transporters to obtain essential nutrients in the “feast or famine” environment of the human mouth. S. mutans and most other streptococci are considered auxotrophic for several essential vitamins including riboflavin (vitamin B2), which is used to generate key cofactors and to perform numerous cellular redox reactions. Despite the well-known contributions of this vitamin to central metabolism, little is known about how S. mutans obtains and metabolizes B2. The uncharacterized protein SMU.1703c displays high sequence homology to the riboflavin transporter RibU. Deletion of SMU.1703c hindered S. mutans growth in complex and defined medium in the absence of saturating levels of exogenous riboflavin, whereas deletion of cotranscribed SMU.1702c alone had no apparent effect on growth. Expression of SMU.1703c in a Bacillus subtilis riboflavin auxotroph functionally complemented growth in nonsaturating riboflavin conditions. S. mutans was also able to grow on flavin adenine dinucleotide (FAD) or flavin mononucleotide (FMN) in an SMU.1703c-dependent manner. Deletion of SMU.1703c and/or SMU.1702c impacted S. mutans acid stress tolerance, as all mutants showed improved growth at pH 5.5 compared to that of the wild type when medium was supplemented with saturating riboflavin. Cooccurrence of SMU.1703c and SMU.1702c, a hypothetical PAP2 family acid phosphatase gene, appears unique to the streptococci and may suggest a connection of SMU.1702c to the acquisition or metabolism of flavins within this genus. Identification of SMU.1703c as a RibU-like riboflavin transporter furthers our understanding of how S. mutans acquires essential micronutrients within the oral cavity and how this pathogen successfully competes within nutrient-starved oral biofilms.IMPORTANCE Dental caries form when acid produced by oral bacteria erodes tooth enamel. This process is driven by the fermentative metabolism of cariogenic bacteria, most notably Streptococcus mutans. Nutrient acquisition is key in the competitive oral cavity, and many organisms have evolved various strategies to procure carbon sources or necessary biomolecules. B vitamins, such as riboflavin, which many oral streptococci must scavenge from the oral environment, are necessary for survival within the competitive oral cavity. However, the primary mechanism and proteins involved in this process remain uncharacterized. This study is important because it identifies a key step in S. mutans riboflavin acquisition and cofactor generation, which may enable the development of novel anticaries treatment strategies via selective targeting of metabolite transporters.


2013 ◽  
Vol 14 (4) ◽  
pp. 601-604 ◽  
Author(s):  
Praveen Kumar Madineni ◽  
Suresh Babu Ghanta ◽  
Naveen Kumar Motupalli ◽  
Mahanthesh Bembalgi ◽  
P Krishnam Raju

ABSTRACT Objectives To study and compare the number of colony forming units of Streptococcus mutans, Streptococcus sanguis, Streptococcus salivarius, Streptococcus mitis and Streptococcus milleri in dentulous, edentulous and in those wearing partial and complete dentures by using semi-quantitative culture method of saliva samples with calibrated standard loop Materials Sterile specimen collection bottles, Mitis salivarius agar plates, Standard loop, Candle jar, Incubator, Colony counter Methodology Study population consisted of 100 subjects with 25 in each group, with an age range of 40 to 80 years, who were attending the Department of Community Dentistry and Prosthodontics at MNR Dental College, Sangareddy, Hyderabad. Unstimulated saliva samples were collected from patients and inoculated on to Mitis salivarius agar plates using calibrated standard loop. The plates were then incubated anaerobically at 37°C for 24 hours and left at room temperature for further 24 hours. Using a colony counter, the number of colonies of each species was counted. Results Streptococcus mutans and Streptococcus mitis predominates in the dentulous group, Streptococcus sanguis in complete denture group, Streptococcus salivarius in edentulous group and Streptococcus milleri in removable partial denture group. Conclusion The results of our study are in accordance with the previous studies, which have sought to differentiate different groups of mutans streptococci using a simple calibrated standard loop. How to cite this article Ealla KKR, Ghanta SB, Motupalli NK, Bembalgi M, Madineni PK, Raju PK. Comparative Analysis of Colony Counts of Different Species of Oral Streptococci in Saliva of Dentulous, Edentulous and in those Wearing Partial and Complete Dentures. J Contemp Dent Pract 2013;14(4):601-604.


2019 ◽  
Vol 17 (3) ◽  
pp. 329-336
Author(s):  
Wang Jinli ◽  
Xu Fenfen ◽  
Zheng Yuan ◽  
Cheng Xu ◽  
Zhang Piaopiao ◽  
...  

Cardiovascular disease including cerebral ischemic stroke is the major complication that increases the morbidity and mortality in patients with diabetes mellitus as much as four times. It has been well established that irisin, with its ability to regulate glucose and lipid homeostasis as well as anti-inflammatory and anti-apoptotic properties, has been widely examined for its therapeutic potentials in managing metabolic disorders. However, the mechanism of irisin in the regulation of cerebral ischemic stroke remains unclear. Using PC12 cells as a model, we have shown that hypoxia/reoxygenation inhibits cell viability and increases lactic dehydrogenase. Irisin, in a dose-dependent manner, reversed these changes. The increase in inflammatory mediators (IL-1β, IL-6, and TNF-α) by hypoxia/reoxygenation was reversed by irisin. Furthermore, the cell apoptosis promoted by hypoxia/reoxygenation was also inhibited by irisin. Irisin suppressed TLR4/MyD88 signaling pathway leading to amelioration of inflammation and apoptosis in PC12 cells. Thus, inhibition of TLR4/MyD88 signaling pathway via irisin could be an important mechanism in the regulation of hypoxia/reoxygenation-induced inflammation and apoptosis in PC12 cells.


2017 ◽  
Vol 68 (11) ◽  
pp. 2691-2693
Author(s):  
Krisztina Martha ◽  
Cristina Bica ◽  
Edva Anna Frunda

By the end of the 60�s, the theory that refined carbohydrates promotes the absorption of saccharolytic Gram-positive microbial species on the tooth surfaces has become generally. Mutans streptococci (Streptococcus mutans and Streptococcus sobrinus) were key players in this theory. On agar plates, Str. mutans produces small, circular colonies, in the presence of glucose, and in the presence of sucrose large, sticky, gelatinous colonies. This gelatinous texture is due to the shell material: mutant 1 � 3 glucose polymers and dextran 1 �! 6 glucose polymers. Str. mutans are able to survive in the oral cavity with a pH lower than 5.5. That is why consecutive multiple sugar intake promotes the colonization of Str. mutans, which results in dental caries in stagnant zones. As oral pH is continuously shifted to acid, more acid-resistant bacteria appear. Our aim was to identify species in infant-mother pair gingival crevicular bacterial flora, which can be detected on high-sucrose culture media and to underline the jeopardy of vertical oral contamination from mother to infant.


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