scholarly journals Construction and Characterization of an Effector Strain of Streptococcus mutans for Replacement Therapy of Dental Caries

2000 ◽  
Vol 68 (2) ◽  
pp. 543-549 ◽  
Author(s):  
J. D. Hillman ◽  
T. A. Brooks ◽  
S. M. Michalek ◽  
C. C. Harmon ◽  
J. L. Snoep ◽  
...  

ABSTRACT An effector strain has been constructed for use in the replacement therapy of dental caries. Recombinant DNA methods were used to make theStreptococcus mutans supercolonizing strain, JH1140, lactate dehydrogenase deficient by deleting virtually all of theldh open reading frame (ORF). To compensate for the resulting metabolic imbalance, a supplemental alcohol dehydrogenase activity was introduced by substituting the adhB ORF fromZymomonas mobilis in place of the deleted ldhORF. The resulting clone, BCS3-L1, was found to produce no detectable lactic acid during growth on a variety of carbon sources, and it produced significantly less total acid due to its increased production of ethanol and acetoin. BCS3-L1 was significantly less cariogenic than JH1140 in both gnotobiotic- and conventional-rodent models. It colonized the teeth of conventional rats as well as JH1140 in both aggressive-displacement and preemptive-colonization models. No gross or microscopic abnormalities of major organs were associated with oral colonization of rats with BCS3-L1 for 6 months. Acid-producing revertants of BCS3-L1 were not observed in samples taken from infected animals (reversion frequency, <10−3) or by screening cultures grown in vitro, where no revertants were observed among 105 colonies examined on pH indicator medium. The reduced pathogenic potential of BCS3-L1, its strong colonization potential, and its genetic stability suggest that this strain is well suited to serve as an effector strain in the replacement therapy of dental caries in humans.

Author(s):  
Hye-Eun Kim ◽  
Yuan Liu ◽  
Atul Dhall ◽  
Marwa Bawazir ◽  
Hyun Koo ◽  
...  

Early childhood caries, a virulent-form of dental caries, is painful, difficult, and costly to treat that has been associated with high levels of Streptococcus mutans (Sm) and Candida albicans (Ca) in plaque-biofilms on teeth. These microorganisms appear to develop a symbiotic cross-kingdom interaction that amplifies the virulence of plaque-biofilms. Although biofilm studies reveal synergistic bacterial-fungal association, how these organisms modulate cross-kingdom biofilm formation and enhance its virulence in the presence of saliva remain largely unknown. Here, we compared the properties of Sm and Sm-Ca biofilms cultured in saliva by examining the biofilm structural organization and capability to sustain an acidic pH environment conducive to enamel demineralization. Intriguingly, Sm-Ca biofilm is rapidly matured and maintained acidic pH-values (~4.3), while Sm biofilm development was retarded and failed to create an acidic environment when cultured in saliva. In turn, the human enamel slab surface was severely demineralized by Sm-Ca biofilms, while there was minimal damage to the enamel surface by Sm biofilm. Interestingly, Sm-Ca biofilms exhibited an acidic environment regardless of their hyphal formation ability. Our data reveal the critical role of symbiotic interaction between S. mutans and C. albicans in human saliva in the context of pathogenesis of dental caries, which may explain how the cross-kingdom interaction contributes to enhanced virulence of plaque-biofilm in the oral cavity.


2014 ◽  
Vol 82 (5) ◽  
pp. 1968-1981 ◽  
Author(s):  
Megan L. Falsetta ◽  
Marlise I. Klein ◽  
Punsiri M. Colonne ◽  
Kathleen Scott-Anne ◽  
Stacy Gregoire ◽  
...  

ABSTRACTStreptococcus mutansis often cited as the main bacterial pathogen in dental caries, particularly in early-childhood caries (ECC).S. mutansmay not act alone;Candida albicanscells are frequently detected along with heavy infection byS. mutansin plaque biofilms from ECC-affected children. It remains to be elucidated whether this association is involved in the enhancement of biofilm virulence. We showed that the ability of these organisms together to form biofilms is enhancedin vitroandin vivo. The presence ofC. albicansaugments the production of exopolysaccharides (EPS), such that cospecies biofilms accrue more biomass and harbor more viableS. mutanscells than single-species biofilms. The resulting 3-dimensional biofilm architecture displays sizeableS. mutansmicrocolonies surrounded by fungal cells, which are enmeshed in a dense EPS-rich matrix. Using a rodent model, we explored the implications of this cross-kingdom interaction for the pathogenesis of dental caries. Coinfected animals displayed higher levels of infection and microbial carriage within plaque biofilms than animals infected with either species alone. Furthermore, coinfection synergistically enhanced biofilm virulence, leading to aggressive onset of the disease with rampant carious lesions. Ourin vitrodata also revealed that glucosyltransferase-derived EPS is a key mediator of cospecies biofilm development and that coexistence withC. albicansinduces the expression of virulence genes inS. mutans(e.g.,gtfB,fabM). We also found thatCandida-derived β1,3-glucans contribute to the EPS matrix structure, while fungal mannan and β-glucan provide sites for GtfB binding and activity. Altogether, we demonstrate a novel mutualistic bacterium-fungus relationship that occurs at a clinically relevant site to amplify the severity of a ubiquitous infectious disease.


2000 ◽  
Vol 68 (5) ◽  
pp. 2621-2629 ◽  
Author(s):  
K. Anne Clancy ◽  
Sylvia Pearson ◽  
William H. Bowen ◽  
Robert A. Burne

ABSTRACT Dental caries results from prolonged plaque acidification that leads to the establishment of a cariogenic microflora and demineralization of the tooth. Urease enzymes of oral bacteria hydrolyze urea to ammonia, which can neutralize plaque acids. To begin to examine the relationship between plaque ureolytic activity and the incidence of dental caries, recombinant, ureolytic strains ofStreptococcus mutans were constructed. Specifically, theureABCEFGD operon from Streptococcus salivarius57.I was integrated into the S. mutans chromosome in such a way that the operon was transcribed from a weak, cognate promoter inS. mutans ACUS4 or a stronger promoter in S. mutans ACUS6. Both strains expressed NiCl2-dependent urease activity, but the maximal urease levels in ACUS6 were threefold higher than those in ACUS4. In vitro pH drop experiments demonstrated that the ability of the recombinant S. mutans strains to moderate a decrease in pH during the simultaneous metabolism of glucose and urea increased proportionately with the level of urease activity expressed. Specific-pathogen-free rats that were infected with ACUS6 and fed a cariogenic diet with drinking water containing 25 mM urea and 50 μM NiCl2 had relatively high levels of oral urease activity, as well as dramatic decreases in the prevalence of smooth-surface caries and the severity of sulcal caries, relative to controls. Urease activity appears to influence plaque biochemistry and metabolism in a manner that reduces cariogenicity, suggesting that recombinant, ureolytic bacteria may be useful to promote dental health.


Author(s):  
Listyaning Kartiko Kinasih ◽  
Idamawati Nababan ◽  
Suci Erawati ◽  
Rouli Natasia M Simanjuntak

Intoduction: Health is the condition of the entire body and body parts of an individual who is free from disease both physically, mentally and socially, thus enabling the individual to be able to carry out daily activities more productively. However, many people neglect their own health, especially in the field of dental and oral health. Caries is one of the most common oral and dental problems. The prevalence of dental caries in Indonesia is high, namely 88.8%. Dental caries is caused by Streptococcus mutans bacteria which plays a role in the conversion of sucrose to lactic acid. Infection due to Streptococcus mutans bacteria can be treated by taking antibiotics. Apart from drugs, antibiotics can also be obtained from natural ingredients, one of which is the tintir castor plant (Jatropha multifida Linn) or commonly known as the betadine. Objective: To see the effect of the antibacterial content of tintir leaves against Streptococcus mutans bacteria and to determine the differences in the antibacterial effect of betadine leaf extract (Jatropha multifida L.) from a concentration of 25%, 50%, 75%, and 100% against Streptococcus mutans. Methods: The type of research used in this study was a laboratory experimental study with a post-test-only control group design as the research design and to test the sensitivity of bacteria using the paper disc diffusion test. Data analysis using One-Way ANOVA. Result: The results of this study indicate the effect of tintir castor leaf extract (Jatropha multifida L.) in inhibiting the growth of Streptococcus mutans bacteria.


2006 ◽  
Vol 188 (3) ◽  
pp. 834-841 ◽  
Author(s):  
Ann R. Griswold ◽  
Max Jameson-Lee ◽  
Robert A. Burne

ABSTRACT We previously demonstrated that Streptococcus mutans expresses a functional agmatine deiminase system (AgDS) encoded by the agmatine-inducible aguBDAC operon (A. R. Griswold, Y. Y. Chen, and R. A. Burne, J. Bacteriol. 186:1902-1904, 2004). The AgDS yields ammonia, CO2, and ATP while converting agmatine to putrescine and is proposed to augment the acid resistance properties and pathogenic potential of S. mutans. To initiate a study of agu gene regulation, the aguB transcription initiation site was identified by primer extension and a putative σ70-like promoter was mapped 5′ to aguB. Analysis of the genome database revealed an open reading frame (SMU.261c) encoding a putative transcriptional regulator located 239 bases upstream of aguB. Inactivation of SMU.261c decreased AgD activity by sevenfold and eliminated agmatine induction. AgD was also found to be induced by certain environmental stresses, including low pH and heat, implying that the AgDS may also be a part of a general stress response pathway of this organism. Interestingly, an AgDS-deficient strain was unable to grow in the presence of 20 mM agmatine, suggesting that the AgDS converts a growth-inhibitory substance into products that can enhance acid tolerance and contribute to the competitive fitness of the organism at low pH. The capacity to detoxify and catabolize agmatine is likely to have major ramifications on oral biofilm ecology.


2017 ◽  
Vol 20 (1) ◽  
pp. 41-46
Author(s):  
Dewi Nurul Mustaqimah ◽  
Josh Erry HW

The increasing prevalence of dental caries is still as a major world health problem. Caries is the direct result of acid production by cariogenic oral pathogens, especially Streptococcus mutans. New and better antimicrobial agents active against cariogenic bacteria with minimal side effects on the oral tissues are much needed, especially natural agents derived directly from plants. Phytochemical studies have shown that the extracts from various parts of mangosteen or Garciniamangostana Linn tree contain varieties of secondary metabolites such as prenylated and oxygenated xanthones, many of which have been found in vitro to have antimicrobial properties against oral pathogens. Several studies which examined the eficacy of herbal for human health have shown that xanthones from mangosteen have remarkable biological activities such as antioxidant, antimicrobial, anticancer etc, and had no cytotoxic effects on human gingival fibroblasts. Their results showed that among these xanthone derivatives obtain from pericarp extract of mangosteen, α-mangostin has the most potent antimicrobial activity against cariogenic Streptococcus mutans. It can be concluded that the strong antimicrobial activity of the pericarp extract of mangosteen is a good drug of choice that might be helpful in preventing the dental caries.


2002 ◽  
Vol 81 (11) ◽  
pp. 784-787 ◽  
Author(s):  
M.W. Fan ◽  
Z. Bian ◽  
Z.X. Peng ◽  
Y. Zhong ◽  
Z. Chen ◽  
...  

A cell-surface protein antigen (PAc) of Streptococcus mutans is considered a virulence factor because it may mediate initial attachment of Streptococcus mutans to tooth surfaces. Thus, inhibiting PAc is predicted to provide protection against caries. To develop vaccines against dental caries, we constructed a DNA vaccine, pCIA-P, which encodes two high-conservative regions of PAc. Expression of the recombinant protein was obtained in eukaryotic cells in vitro and in vivo. In this report, we provide evidence that fewer caries lesions, and high levels of PAc-specific salivary IgA antibody and serum IgG antibody, were observed in gnotobiotic rats following targeted salivary gland (TSG) administration of pCIA-P. This study shows that the recombinant DNA vaccine pCIA-P could induce protective anti-caries immune responses and that TSG immunization is a promising strategy for the inhibition of dental caries.


2017 ◽  
Vol 19 (2) ◽  
pp. 95
Author(s):  
Maria Paula Jacobucci Botelho ◽  
Amanda Da Silva ◽  
Fernanda Da Conceição Antônio Ferreira ◽  
Lígia Maria Molinari Capel

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


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