scholarly journals Novel Synthetic Antimicrobial Peptides against Streptococcus mutans

2007 ◽  
Vol 51 (4) ◽  
pp. 1351-1358 ◽  
Author(s):  
Jian He ◽  
Randal Eckert ◽  
Thanh Pharm ◽  
Maurice D. Simanian ◽  
Chuhong Hu ◽  
...  
Keyword(s):  
Dental Caries ◽  
Antimicrobial Peptides ◽  
Streptococcus Mutans ◽  
Peptide Libraries ◽  
Tooth Surface ◽  
Fusion Peptides ◽  
Biochemical Characteristics ◽  
Killing Activity ◽  
Constrained Peptides ◽  
Synthetic Antimicrobial Peptides

ABSTRACT Streptococcus mutans, a common oral pathogen and the causative agent of dental caries, has persisted and even thrived on the tooth surface despite constant removal and eradication efforts. In this study, we generated a number of synthetic antimicrobial peptides against this bacterium via construction and screening of several structurally diverse peptide libraries where the hydrophobicity and charge within each library was varied incrementally in order to generate a collection of peptides with different biochemical characteristics. From these libraries, we identified multiple peptides with robust killing activity against S. mutans. To further improve their effectiveness, the most bactericidal peptides from each library were synthesized together as one molecule, in various combinations, with and without a flexible peptide linker between each antimicrobial region. Many of these “fusion” peptides had enhanced killing activities in comparison with those of the original nonconjoined molecules. The results presented here illustrate that small libraries of biochemically constrained peptides can be used to generate antimicrobial peptides against S. mutans, several of which may be likely candidates for the development of anticaries agents.

scholarly journals Essential Roles of thesppRAFructose-Phosphate Phosphohydrolase Operon in Carbohydrate Metabolism and Virulence Expression byStreptococcus mutans

2018 ◽  
Vol 201 (2) ◽  
Author(s):  
Lin Zeng ◽  
Robert A. Burne
Keyword(s):  
Dental Caries ◽  
Organic Acids ◽  
Streptococcus Mutans ◽  
Biochemical Characterization ◽  
Constitutive Expression ◽  
Extracellular Dna ◽  
Tooth Surface ◽  
Oral Diseases ◽  
Sugar Phosphate ◽  
Content Type

ABSTRACTThe dental caries pathogenStreptococcus mutanscan ferment a variety of sugars to produce organic acids. Exposure ofS. mutansto certain nonmetabolizable carbohydrates, such as xylitol, impairs growth and can cause cell death. Recently, the presence of a sugar-phosphate stress inS. mutanswas demonstrated using a mutant lacking 1-phosphofructokinase (FruK) that accumulates fructose-1-phosphate (F-1-P). Here, we studied an operon inS. mutans,sppRA, which was highly expressed in thefruKmutant. Biochemical characterization of a recombinant SppA protein indicated that it possessed hexose-phosphate phosphohydrolase activity, with preferences for F-1-P and, to a lesser degree, fructose-6-phosphate (F-6-P). SppA activity was stimulated by Mg2+and Mn2+but inhibited by NaF. SppR, a DeoR family regulator, repressed the expression of thesppRAoperon to minimum levels in the absence of the fructose-derived metabolite F-1-P and likely also F-6-P. The accumulation of F-1-P, as a result of growth on fructose, not only inducedsppAexpression, but it significantly altered biofilm maturation through increased cell lysis and enhanced extracellular DNA release. Constitutive expression ofsppA, via a plasmid or by deletingsppR, greatly alleviated fructose-induced stress in afruKmutant, enhanced resistance to xylitol, and reversed the effects of fructose on biofilm formation. Finally, by identifying three additional putative phosphatases that are capable of promoting sugar-phosphate tolerance, we show thatS. mutansis capable of mounting a sugar-phosphate stress response by modulating the levels of certain glycolytic intermediates, functions that are interconnected with the ability of the organism to manifest key virulence behaviors.IMPORTANCEStreptococcus mutansis a major etiologic agent for dental caries, primarily due to its ability to form biofilms on the tooth surface and to convert carbohydrates into organic acids. We have discovered a two-gene operon inS. mutansthat regulates fructose metabolism by controlling the levels of fructose-1-phosphate, a potential signaling compound that affects bacterial behaviors. With fructose becoming increasingly common and abundant in the human diet, we reveal the ways that fructose may alter bacterial development, stress tolerance, and microbial ecology in the oral cavity to promote oral diseases.

scholarly journals Antibiofilm Activity of Mangosteen (Garcinia mangostana L.) Flavonoids against Streptococcus mutans Bacteria

2020 ◽  
Vol 10 (2) ◽  
pp. 48
Author(s):  
Sri Kunarti ◽  
Aulia Ramadhani ◽  
Laskmiari Setyowati
Keyword(s):  
Dental Caries ◽  
Streptococcus Mutans ◽  
Tooth Enamel ◽  
Tooth Surface ◽  
Control Group ◽  
Antibiofilm Activity ◽  
Garcinia Mangostana ◽  
Control Group Design ◽  
Biofilm Inhibition ◽  
Significant Difference

Background: Dental caries is one of the most common infectious diseases and often occurs in the community caused by bacteria. Attached bacteria in the tooth surface for a long time will form a biofilm and will lead to demineralization characterized by damage in the structure of the tooth enamel. The bacteria that cause dental caries and can form biofilms is Streptococcus mutans. The bacteria inside biofilms are more resistant to antibacterial agents. Flavonoids in mangosteen pericarp extract can be a cleaner alternative for the anti-biofilm cavity that has properties against Streptococcus mutans. Purpose: To determine the activity of flavonoids in mangosteen pericarp extract at a certain concentration against Streptococcus mutans bacteria. Methods: This study was a laboratory experimental study with a post-test only control group design. Streptococcus mutans were diluted according to the Mc Farland dilution standard 106 in Tryptic Soy Broth (TSB) medium and put in a flexible U-bottom microtiter plate. Then it was incubated for 5x24 hours and checked using crystal violet simple staining to see the formation of biofilms. Flavonoid extract of mangosteen pericarp performed serial dilution in a concentration of 100%, 50%, 25%, 12.5%, 6.25%, 3.125%, 1.56%, and 0.78% was added, and the incubation process were conducted for 1x24 hours. OD (Optical Density) readings were done with a wavelength of 595 nm. Results: There was a significant difference between the test groups and the positive control group. The concentration of 100% had the anti-biofilm activity and showed the value of the highest percentage of inhibition, whilst the concentration of 0.78% showed a minimum biofilm inhibition concentration. The results were demonstrated by a statistical analysis test. Conclusion: Flavonoid extract of mangosteen pericarp at a certain concentration has anti-biofilm activity against Streptococcus mutans biofilm.

scholarly journals Cloning, Expression, Purification, and Preliminary Characterization of Single-Crystal X-Ray Diffraction of Glucosyltransferase B of Streptococcus mutans

2019 ◽  
Vol 14 (5) ◽  
pp. 1934578X1984933
Author(s):  
Joshua L. Mieher ◽  
Norbert Schormann ◽  
Manisha Patel ◽  
Hui Wu ◽  
Champion Deivanayagam
Keyword(s):  
Dental Caries ◽  
Oral Cavity ◽  
Single Crystal ◽  
Streptococcus Mutans ◽  
Tooth Enamel ◽  
Tooth Surface ◽  
X Ray Diffraction ◽  
Persistent Disease ◽  
X Ray

Dental caries characterized by acid damage of tooth enamel is a persistent disease that begins with the formation of biofilms on the tooth surface. The secreted glucosyltransferases enable Streptococcus mutans to synthesize extracellular glucan polymers using ingested starch within the oral cavity, which eventually results in the production of acid, a contributing factor to cariogenesis. In this paper, we report the cloning, expression, purification, crystallization, and preliminary X-ray diffraction characterization of glucosyltransferase B.

scholarly journals Intranasal Immunization against Dental Caries with a Streptococcus mutans-Enriched Fimbrial Preparation

1999 ◽  
Vol 6 (3) ◽  
pp. 405-409 ◽  
Author(s):  
Margherita Fontana ◽  
Ann J. Dunipace ◽  
George K. Stookey ◽  
Richard L. Gregory
Keyword(s):  
Dental Caries ◽  
Cholera Toxin ◽  
Streptococcus Mutans ◽  
Surface Proteins ◽  
Mucosal Vaccine ◽  
Tooth Surface ◽  
Cholera Toxin B Subunit ◽  
Sprague Dawley ◽  
Igg Antibody ◽  
Group A

ABSTRACT Streptococcus mutans has been identified as the major etiological agent of human dental caries. The first step in the initiation of infection by this pathogenic bacterium is its attachment (i.e., through bacterial surface proteins such as glucosyltransferases, P1, glucan-binding proteins, and fimbriae) to a suitable receptor. It is hypothesized that a mucosal vaccine against a combination ofS. mutans surface proteins would protect against dental caries by inducing specific salivary immunoglobulin A (IgA) antibodies which may reduce bacterial pathogenesis and adhesion to the tooth surface by affecting several adhesins simultaneously. Conventional Sprague-Dawley rats, infected withS. mutans at 18 to 20 days of age, were intranasally immunized with a mixture of S. mutans surface proteins, enriched for fimbriae and conjugated with cholera toxin B subunit (CTB) plus free cholera toxin (CT) at 13, 15, 22, 29, and 36 days of age (group A). Control rats were either not immunized (group B) or immunized with adjuvant alone (CTB and CT [group C]). At the termination of the study (when rats were 46 days of age), immunized animals (group A) had significantly (P < 0.05) higher salivary IgA and serum IgG antibody responses to the mixture of surface proteins and to whole bacterial cells than did the other two groups (B and C). No significant differences were found in the average numbers of recoveredS. mutans cells among groups. However, statistically fewer smooth-surface enamel lesions (buccal and lingual) were detected in the immunized group than in the two other groups. Therefore, a mixture of S. mutans surface proteins, enriched with fimbria components, appears to be a promising immunogen candidate for a mucosal vaccine against dental caries.

scholarly journals Uji Konsentrasi Hambat Minimum Ekstrak Daun Gedi (Abelmoschus manihot L.) terhadap Pertumbuhan Bakteri Streptococcus Mutans

e-GIGI ◽  
2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Helen N. Sekeon ◽  
Heriyannis Homenta ◽  
Michael A. Leman
Keyword(s):  
Dental Caries ◽  
Streptococcus Mutans ◽  
Leaf Extract ◽  
Inhibitory Concentration ◽  
Inhibitory Effect ◽  
Tooth Surface ◽  
Control Group ◽  
Control Group Design ◽  
Cariogenic Bacteria ◽  
Group Design

Abstract: Streptococcus mutans is the most common bacterium that causes dental caries due to its ability to ferment carbohydrates into acid resulting in the decreased pH on the tooth surface. Prevention of dental caries could be achieved by inhibiting the growth of cariogenic bacteria. Various efforts to control and prevent the cariogenic bacteria include the usage of herbal ingredients; one of them is gedi leaves (Abelmoschus manihot L.). These gedi leaves contain bioactive compounds such as flavonoids, alkaloids, steroids, and saponins. This study was aimed to prove that gedi leaf extract had inhibitory effect on the growth of S.mutans and to obtain the minimum inhibitory concentration (MIC) of this extract on the growth of S. mutans. This was a true experimental design with a randomized pretest-posttest control group design. Gedi leaf extract was obtained by maceration method in 96% ethanol. The results showed that gedi leaf extract had an antibacterial effect on the growth of S. mutans. We used turbidimetry, UV-Vis spectrophotometer, and two times of treatment to obtain the MIC of gedi leaf extract on Streptococcus mutans which was 6.25%. Conclusion: Gedi leaf extract could inhibit the growth of S. mutans with a MIC of 6.25%.Keywords: dental caries, gedi leaf extract (Abelmoschus manihot L.), Streptococcus mutans Abstrak: Streptococcus mutans merupakan bakteri yang paling banyak menyebabkan karies gigi karena bakteri ini berkemampuan memfermentasi karbohidrat menjadi asam yang berakibat turunnya pH pada permukaan gigi. Pencegahan karies gigi dapat dicapai dengan menghambat pertumbuhan bakteri kariogenik. Berbagai upaya dilakukan untuk mengen-dalikan dan mencegah bakteri kariogenik, antara lain dengan menggunakan bahan herbal; salah satunya yaitu tanaman gedi (Abelmoschus manihot L.). Daun gedi mengandung senyawa bioaktif antara lain flavonoid, alkaloid, steroid, dan saponin. Penelitian ini bertujuan untuk membuktikan efek inhibisi ekstrak daun gedi terhadap pertumbuhan S. mutans dan mendapatkan konsentrasi hambat minimum (KHM) ekstrak daun gedi terhadap pertumbuhan bakteri S. mutans. Jenis penelitian ini ialah eksperimental murni dengan randomized pretest-posttest control group design. Ekstrak daun gedi dibuat dengan metode maserasi dengan menggunakan etanol 96%. Hasil penelitian menunjukkan bahwa ekstrak daun gedi (Abelmoschus manihot L.) memiliki efek antibakteri dalam menghambat pertumbuhan bakteri Streptococcus mutans. Dengan menggunakan metode turbidimetri dan spektrofotometer UV-Vis dalam 2 (dua) kali perlakuan maka diperoleh KHM ekstrak daun gedi (Abelmoschus manihot L.) terhadap bakteri Streptococcus mutans terdapat pada konsentrasi 6,25%. Simpulan: Ekstrak daun gedi dapat meghambat pertumbuhan Streptococcus mutans dengan KHM pada konsentrasi 6,25%.Kata kunci: karies gigi, ekstrak daun gedi (Abelmoschus manihot L.), Streptococcus mutans

pH Response and Tooth Surface Solubility at the Tooth/Bacteria Interface

2017 ◽  
Vol 51 (2) ◽  
pp. 160-166 ◽  
Author(s):  
Gen Mayanagi ◽  
Koei Igarashi ◽  
Jumpei Washio ◽  
Nobuhiro Takahashi
Keyword(s):  
Dental Caries ◽  
Streptococcus Mutans ◽  
Polymethyl Methacrylate ◽  
Proteolytic Activity ◽  
Tooth Surface ◽  
Ph Response ◽  
Mineral Solubility ◽  
Experimental Apparatus ◽  
Root Dentin ◽  
Dissolved Components

Evaluating the physiochemical processes at the tooth surface/bacteria interface is important for elucidating the etiology of dental caries. This study aimed to compare the mineral solubility and protein degradation of coronal enamel (CE) and root dentin (RD), and investigate the involvement of dissolved components in bacteria-induced pH changes using a model of tooth/bacteria interface. An experimental apparatus forming a well was made of polymethyl methacrylate, and a bovine tooth (CE or RD) specimen was fixed at the bottom of the well. A miniature pH electrode was placed on the tooth, and Streptococcus mutans NCTC 10449 cells, grown in 0.5% glucose-containing complex medium, were packed into the well. The pH at the tooth/S. mutans interface was monitored continuously for 120 min after the addition of 0.5% glucose at 37°C. S. mutans cells were recovered from the wells, and the amounts of lactate and calcium were measured using a portable lactate meter and a fluorescent dye, respectively. Proteolytic activity was also evaluated fluorometrically. The pH of the RD/S. mutans interface was significantly higher than that of the CE/S. mutans interface (30 min: 6.37 ± 0.12 vs. 6.18 ± 0.11, 60 min: 6.08 ± 0.14 vs. 5.66 ± 0.27, 90 min: 5.49 ± 0.24 vs. 5.14 ± 0.22, p < 0.05). Greater amounts of calcium were dissolved from RD (3.19 ± 0.74 µg/mL) than from CE (1.84 ± 0.68 µg/mL; p < 0.05), while similar amounts of lactate were produced. Proteolytic activity was not detected at any of the interfaces. These results indicate that RD is more soluble to bacteria-induced acidification than CE. This method can contribute to the evaluation and development of caries-preventive materials.

scholarly journals Avaliação in vitro da Atividade Antimicrobiana de Extrato Alcoólico de Própolis Comparado à Solução de Clorexidina 0,12%

2017 ◽  
Vol 19 (2) ◽  
pp. 95
Author(s):  
Maria Paula Jacobucci Botelho ◽  
Amanda Da Silva ◽  
Fernanda Da Conceição Antônio Ferreira ◽  
Lígia Maria Molinari Capel
Keyword(s):  
Drinking Water ◽  
Dental Caries ◽  
Streptococcus Mutans ◽  
Positive Control ◽  
Negative Control ◽  
Tooth Surface ◽  
Dental Biofilm ◽  
Fermentable Carbohydrates ◽  
Broad Understanding

Apesar dos esforços e do amplo entendimento sobre a cárie dental, está continua bastante prevalente em determinados segmentos da população. A doença apresenta etiologia multifatorial, com a dieta e os micro-organismos envolvidos desenvolvendo papéis fundamentais. Os Streptococcus mutans têm papel fundamental em seu início e é ubíquo em crianças a partir dos sete anos de idade. Para controlar essas bactérias é preciso uma dieta com baixo consumo de sacarose e de carboidratos fermentáveis, o que nem sempre se consegue. Sua remoção da superfície dentária só é possível por meio da fricção mecânica, mas pode-se prevenir sua presença no biofilme dentário através da utilização de antissépticos. O mais utilizado na Odontologia é a clorexidina, porém como não é isenta de efeitos adversos, atualmente, vêm-se estudando produtos alternativos, dentre os quais alguns agentes fitoterápicos. O objetivo deste trabalho foi analisar a atividade da própolis contra os S. mutans em relação à clorexidina. Foi analisada própolis 70% diluída em álcool 96% e após diluída em água potável 5ml, própolis 50%, própolis 12% e clorexidina 0,12% (controle positivo), e solução salina (controle negativo). O operador foi cego em relação às substâncias que estava utilizando. Somente a clorexidina 0.12% e a própolis 12% apresentaram halo de inibição claro. Neste estudo, a clorexidina apresentou melhor atividade contra os S.mutans.Palavras-chave: Clorexidina. Cárie Dentária. Streptococcus mutans.AbstractDespite the efforts and the broad understanding on dental caries, it is still quite prevalent in certain segments of the population. The disease shows a multifactorial etiology, with diet and microorganisms involved developing fundamental roles. The Streptococcus mutans has key role in its beginning and is ubiquitous in children as young as seven years of age. To control these bacteria a diet is necessary with low consumption of sucrose and of fermentable carbohydrates, which is not always possible. The tooth surface removal is only possible through mechanical friction, but it is possible to prevent the presence of dental biofilm through the use of antiseptics. The most widely used in dentistry is chlorhexidine, however as it is not devoid of adverse effects, currently alternative products have been studying, among which some herbal agents. The aim of this study was to analyze the activity of propolis against S. mutans compared to chlorhexidine. Propolis was analyzed diluted in 70% ethanol 96% and further diluted in drinking water 5ml, 50% propolis, propolis 12% and 0.12% chlorhexidine (positive control), and saline (negative control). The operator was blinded for the substances he was using. Only 0.12% chlorhexidine and 12% propolis showed clear inhibition halo. In this study the chlorhexidine presented better activity against S. mutans.Keywords: Chlorhexidine. Dental Caries. Antimicrobials. Streptococcus mutans

scholarly journals Identifikasi gen kariogenik glukosiltransferase Streptococcus mutans pada pasien karies gigiIdentification of Streptococcus mutans cariogenic gene glucosyltransferase (gtf) in dental caries patients

2021 ◽  
Vol 33 (1) ◽  
pp. 14
Author(s):  
Rita Endriani ◽  
Fajri Marindra Siregar ◽  
Elita Rafni ◽  
Rahmat Kemal Azhari ◽  
Jefrizal Jefrizal
Keyword(s):  
Polymerase Chain Reaction ◽  
Dental Caries ◽  
Streptococcus Mutans ◽  
Cellular Adhesion ◽  
Tooth Surface ◽  
Chain Reaction ◽  
Consecutive Sampling ◽  
Pcr Method ◽  
Polymerase Chain ◽  
Attachment Process

Pendahuluan: Streptococcus mutans (S. mutans) merupakan bakteri yang mempunyai glukosiltransferase surface (GTFs) yang berperan pada proses  perlekatan dan virulensi bakteri pada permukaan gigi. Enzim GTFs terdiri atas  tiga jenis enzim GTFs yaitu GTFB, GTFC dan GTFD dan masing-masing enzim ini dikode oleh gen gtfB, gtfC dan gtfD yang juga berperan sebagai prekursor dalam adhesi seluler plak gigi yang dapat menyebabkan karies gigi. Tujuan penelitian adalah mengidentifikasi gen gtfC dan gtfD S. mutans  pada pasien karies gigi. Metode: Penelitian dilakukan dengan consecutive sampling. Sampel penelitian diambil dari kerokan jaringan karies gigi, diisolasi, dikultur, dan diidentifikasi di laboratorium Mikrobiologi dan Sentral FK UNRI. Identifikasi S. mutans dan gen kariogenik gtfC dan gtfD menggunakan metode Polymerase Chain Reaction (PCR). Data ditampilkan dalam bentuk tabel distribusi frekuensi dan dinyatakan dalam persentase Hasil: Dari 60 kerokan jaringan karies  didapatkan  S. mutans sebanyak 10 isolat, sedangkan gen gtfC dan gen gtfD didapatkan masing-masing 4 (40%) isolat. Simpulan: Gen kariogenik teridentifikasi gen gtfC dan gtfD pada isolat S. mutans dari pasien karies gigi sebanyak 40%.Kata kunci: gtfC, gtfD, kariogenik glukosiltransferase Streptococcus mutans. ABSTRACTIntroduction: Streptococcus mutans (S. mutans) is a bacterium with a glucosyltransferase (Gtfs) surface, which plays a role in the attachment process and bacteria virulence on the tooth surface. The Gtfs enzyme consists of three types of Gtfs enzymes, namely GtfB, GtfC, and GtfD. These enzymes are encoded by the GtfB, GtfC, and GtfD genes, which also act as precursors in the cellular adhesion of dental plaque that can cause dental caries. This study was aimed to identify the GtfC and GtfD of S. mutans in dental caries patients. Methods: This study was conducted with consecutive sampling. Research samples were taken from dental caries tissue scrapings, isolated, cultured, and identified in the Microbiology and Central Laboratory of the Faculty of Medicine University of Riau. Identification of S. mutans and GtfC and GtfD cariogenic genes using the Polymerase Chain Reaction (PCR) method. The data was displayed in the form of a frequency distribution table and expressed as a percentage. Results: From 60 caries tissue scrapings, ten isolates were obtained, while the GtfC gene and GtfD gene were obtained 4 (40%) isolates each. Conclusion: Forty percents of S. mutans isolates from dental caries patients were identified as the GtfC and GtfD cariogenic genes.Keywords: GtfC, GtfD, cariogenic, Streptococcus mutans glucosyltransferase.

scholarly journals Exploration of the antimicrobial synergy between selected natural substances on Streptococcus mutans to identify candidates for the control of dental caries

2021 ◽  
Author(s):  
Alisha Evangeline Prince ◽  
David J McDonald ◽  
Soumya Roy
Keyword(s):  
Dental Caries ◽  
Streptococcus Mutans ◽  
Dental Plaque ◽  
Synergistic Effects ◽  
Treatment Options ◽  
Antimicrobial Effect ◽  
Antimicrobial Action ◽  
Tooth Surface ◽  
Manuka Honey ◽  
Synergistic Combinations

Dental caries is caused by dental plaque, a community of micro-organisms embedded in an extracellular polymer matrix as a biofilm on the tooth surface. Natural products that are widely available could be used as an alternative or adjunctive anti-caries therapy. Sometimes, when two products are used together, they yield a more powerful antimicrobial effect than the anticipated additive effect. These synergistic combinations are often better treatment options because individual agents may not have sufficient antimicrobial action to be effective when used alone. Cranberries contain phenolic compounds like proanthocyanidins (PAC) that disrupt biofilm formation. Manuka honey has high concentrations of the agent methylglyoxal, which is cariostatic. Because these agents have varied modes of antimicrobial action, they show potential for possible synergistic effects when paired. Various cranberry extracts were tested pairwise with manuka honey or methylglyoxal by well-diffusion assays and 96-well checkerboard assays in the presence of Streptococcus mutans to test for synergy. Synergy was demonstrated in two of the cranberry extracts paired with manuka honey. The synergistic combinations found in this research thus can be considered as candidates for the formulation of a dentifrice that could be used to inhibit the formation of dental plaque and thereby avoid the development of caries.

scholarly journals Nitrite Production from Nitrate and Its Link with Lactate Metabolism in Oral Veillonella spp.

2020 ◽  
Vol 86 (20) ◽  
Author(s):  
Dimas Prasetianto Wicaksono ◽  
Jumpei Washio ◽  
Yuki Abiko ◽  
Hitomi Domon ◽  
Nobuhiro Takahashi
Keyword(s):  
Lactic Acid ◽  
Dental Caries ◽  
Oral Cavity ◽  
Streptococcus Mutans ◽  
General Health ◽  
Pathogenic Bacteria ◽  
Reducing Power ◽  
Lactate Metabolism ◽  
Content Type ◽  
Biochemical Characteristics

ABSTRACT Veillonella species are among the major anaerobes in the oral cavity and are frequently detected in both caries lesions and healthy oral microbiomes. They possess the ability to utilize lactate and convert nitrate (NO3–) into nitrite (NO2–). Recently, interest in NO2– has increased rapidly because of its beneficial effects on oral and general health; i.e., it inhibits the growth and metabolism of oral pathogenic bacteria, such as Streptococcus mutans, and lowers systemic blood pressure. However, there is only limited information about the biochemical characteristics of NO2– production by Veillonella species. We found that NO3– did not inhibit the growth of Veillonella atypica or Veillonella parvula, and it inhibited the growth of Streptococcus mutans only at a high concentration (100 mM). However, NO2– inhibited the growth of Streptococcus mutans at a low concentration (0.5 mM), while a higher concentration of NO2– (20 mM) was needed to inhibit the growth of Veillonella species. NO2– production by Veillonella species was increased by environmental factors (lactate, acidic pH, and anaerobic conditions) and growth conditions (the presence of NO3– or NO2–) and was linked to anaerobic lactate metabolism. A stoichiometric evaluation revealed that NO3– is reduced to NO2– by accepting reducing power derived from the oxidization of lactate. These findings suggest that the biochemical characteristics of NO2– production from NO3– and its linkage with lactate metabolism in oral Veillonella species may play a key role in maintaining good oral and general health. IMPORTANCE The prevalence of dental caries is still high around the world. Dental caries is initiated when the teeth are exposed to acid, such as lactic acid, produced via carbohydrate metabolism by acidogenic microorganisms. Veillonella species, which are among the major oral microorganisms, are considered to be beneficial bacteria due to their ability to convert lactic acid to weaker acids and to produce NO2– from NO3–, which is thought to be good for both oral and general health. Therefore, it is clear that there is a need to elucidate the biochemical characteristics of NO2– production in Veillonella species. The significance of our research is that we have found that lactate metabolism is linked to NO2– production by Veillonella species in the environment found in the oral cavity. This study suggests that Veillonella species are potential candidates for maintaining oral and general health.

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