scholarly journals Differential Utilization of Basic Proline-Rich Glycoproteins during Growth of Oral Bacteria in Saliva

2016 ◽  
Vol 82 (17) ◽  
pp. 5249-5258 ◽  
Author(s):  
Yuan Zhou ◽  
Jinghua Yang ◽  
Luxia Zhang ◽  
Xuedong Zhou ◽  
John O. Cisar ◽  
...  

ABSTRACTAlthough saliva is widely recognized as a primary source of carbon and nitrogen for growth of the dental plaque biofilm community, little is known about how different oral bacteria utilize specific salivary components. To address this question, 32 strains representing 16 genera commonly isolated from early plaque biofilms were compared for growth over two transfers in stimulated (by chewing Parafilm) whole saliva that was stabilized by heat treatment and dialysis. The cell densities, measured by quantitative PCR (qPCR), ranged from ∼1 × 106to 1 × 107/ml for strains ofStreptococcus gordonii,Streptococcus oralis, andStreptococcus mitisand one strain ofStreptococcus sanguinis. Strains ofStreptococcus mutans,Gemella haemolysans, andGranulicatella adiacensreached ∼1 × 105to 1 × 106/ml. In contrast, little or no growth was noted for three other strains ofS. sanguinis, as well as for strains ofStreptococcus parasanguinis,Streptococcus salivarius,Streptococcus vestibularis,Streptococcus sobrinus,Actinomycesspp.,Abiotrophia defectiva, andRothia dentocariosa. SDS-PAGE, lectin blotting, and two-dimensional gel electrophoresis of saliva from cultures ofS. gordonii,S. oralis, andS. mitisrevealed species-specific differences in the degradation of basic proline-rich glycoproteins (PRG). In contrast, saliva from cultures of other bacteria was indistinguishable from control saliva. Species-dependent differences in the utilization of individual host sugars were minor. Thus, differences in salivary glycan foraging between oral species may be important to cross-feeding and cooperation between organisms in dental plaque biofilm development.IMPORTANCEBacteria in the mouth use saliva for nutrition. How each of the many types of bacteria uses saliva is not clear. We show that a major protein in saliva, called PRG, is an important nutrition source for certain bacteria but not for others. PRG has many sugar molecules linked in chains, but the sugar is not available for bacteria until the chains are degraded. The bacteria that can grow by digesting this protein break the sugar chains into parts which not only support their own growth but could also be available to support the growth of those bacteria that cannot use the intact protein.

2020 ◽  
Vol 202 (12) ◽  
Author(s):  
Delphine Dufour ◽  
Abdelahhad Barbour ◽  
Yuki Chan ◽  
Marcus Cheng ◽  
Taimoor Rahman ◽  
...  

ABSTRACT Bacteriocins are ribosomally synthesized proteinaceous antibacterial peptides. They selectively interfere with the growth of other bacteria. The production and secretion of bacteriocins confer a distinct ecological advantage to the producer in competing against other bacteria that are present in the same ecological niche. Streptococcus mutans, a significant contributor to the development of dental caries, is one of the most prolific producers of bacteriocins, known as mutacins in S. mutans. In this study, we characterized the locus encoding mutacin B-Ny266, a lantibiotic with a broad spectrum of activity. The chromosomal locus is composed of six predicted operon structures encoding proteins involved in regulation, antimicrobial activity, biosynthesis, modification, transport, and immunity. Mutacin B-Ny266 was purified from semisolid cultures, and two inhibitory peptides, LanA and LanA′, were detected. Both peptides were highly modified. Such modifications include dehydration of serine and threonine and the formation of a C-terminal aminovinyl-cysteine (AviCys) ring. While LanA peptide alone is absolutely required for antimicrobial activity, the presence of LanA′ enhanced the activity of LanA, suggesting that B-Ny266 may function as a two-peptide lantibiotic. The activation of lanAA′ expression is most likely controlled by the conserved two-component system NsrRS, which is activated by LanA peptide but not by LanA′. The chromosomal locus encoding mutacin B-Ny266 was not universally conserved in all sequenced S. mutans genomes. Intriguingly, the genes encoding LanAA′ peptides were restricted to the most invasive serotypes of S. mutans. IMPORTANCE Although dental caries is largely preventable, it remains the most common and costly infectious disease worldwide. Caries is initiated by the presence of dental plaque biofilm that contains Streptococcus mutans, a species extensively characterized by its role in caries development and formation. S. mutans deploys an arsenal of strategies to establish itself within the oral cavity. One of them is the production of bacteriocins that confer a competitive advantage by targeting and killing closely related competitors. In this work, we found that mutacin B-Ny266 is a potent lantibiotic that is effective at killing a wide array of oral streptococci, including nearly all S. mutans strains tested. Lantibiotics produced by oral bacteria could represent a promising strategy to target caries pathogens embedded in dental plaque biofilm.


2017 ◽  
Vol 83 (24) ◽  
Author(s):  
Nyssa Cullin ◽  
Sylvio Redanz ◽  
Kirsten J. Lampi ◽  
Justin Merritt ◽  
Jens Kreth

ABSTRACT The overall health of the oral cavity is dependent on proper homeostasis between health-associated bacterial colonizers and bacteria known to promote dental caries. Streptococcus sanguinis is a health-associated commensal organism, a known early colonizer of the acquired tooth pellicle, and is naturally competent. We have shown that LytF, a competence-controlled murein hydrolase, is capable of inducing the release of extracellular DNA (eDNA) from oral bacteria. Precipitated LytF and purified LytF were used as treatments against planktonic cultures and biofilms. Larger amounts of eDNA were released from cultures treated with protein samples containing LytF. Additionally, LytF could affect biofilm formation and cellular morphology. Biofilm formation was significantly decreased in the lytF-complemented strain, in which increased amounts of LytF are present. The same strain also exhibited cell morphology defects in both planktonic cultures and biofilms. Furthermore, the LytF cell morphology phenotype was reproducible in wild-type cells using purified LytF protein. In sum, our findings demonstrate that LytF can induce the release of eDNA from oral bacteria, and they suggest that, without proper regulation of LytF, cells display morphological abnormalities that contribute to biofilm malformation. In the context of the oral biofilm, LytF may play important roles as part of the competence and biofilm development programs, as well as increasing the availability of eDNA. IMPORTANCE Streptococcus sanguinis, a commensal organism in the oral cavity and one of the pioneer colonizers of the tooth surface, is associated with the overall health of the oral environment. Our laboratory showed previously that, under aerobic conditions, S. sanguinis can produce H2O2 to inhibit the growth of bacterial species that promote dental caries. This production of H2O2 by S. sanguinis also induces the release of eDNA, which is essential for proper biofilm formation. Under anaerobic conditions, S. sanguinis does not produce H2O2 but DNA is still released. Determining how S. sanguinis releases DNA is thus essential to understand biofilm formation in the oral cavity.


Author(s):  
Siew Woh Choo ◽  
Waleed K. Mohammed ◽  
Naresh V. R. Mutha ◽  
Nadia Rostami ◽  
Halah Ahmed ◽  
...  

Cell-cell adhesion between oral bacteria plays a key role in the development of polymicrobial communities such as dental plaque. Oral streptococci such as Streptococcus gordonii and Streptococcus oralis are important early colonizers of dental plaque and bind to a wide range of different oral microorganisms, forming multispecies clumps or ‘coaggregates’. S. gordonii actively responds to coaggregation by regulating gene expression. To further understand these responses, we assessed gene regulation in S. gordonii and S. oralis following coaggregation in 25% human saliva. Coaggregates were formed by mixing and, after 30 minutes, RNA was extracted for Dual RNASeq analysis. In S. oralis , 18 genes (6 upregulated and 12 downregulated) were regulated by coaggregation. Significantly downregulated genes encoded functions such as amino acid and antibiotic biosynthesis, ribosome and central carbon metabolism. In total, 28 genes were differentially regulated in Streptococcus gordonii (25 upregulated and 3 downregulated). Many genes associated with transporters and a two component (NisK/SpaK) regulatory system were upregulated following coaggregation. Our comparative analyses of S. gordonii - S. oralis with different previously published S. gordonii pairings ( S. gordonii - Fusobacterium nucleatum and S. gordonii - Veillonella parvula ) suggest that the gene regulation is specific to each pairing and responses do not appear to be conserved. This ability to distinguish between neighboring bacteria may be important for S. gordonii to adapt appropriately during the development of complex biofilms such as dental plaque. Importance Dental plaque is responsible for two of the most prevalent diseases in humans, dental caries and periodontitis. Controlling the formation of dental plaque and preventing the transition from oral health to disease requires a detailed understanding of microbial colonization and biofilm development. Streptococci are among the most common colonizers of dental plaque. This study identifies key genes that are regulated when oral streptococci bind to one another, as they do in the early stages of dental plaque formation. We show that specific genes are regulated in two different oral streptococci following the formation of mixed-species aggregates. The specific responses of S. gordonii to coaggregation with S. oralis are different from coaggregation with other oral bacteria. Targeting the key genes that are upregulated during interspecies interactions may be a powerful approach to control the developing biofilm and maintain oral health.


2011 ◽  
pp. 430-437 ◽  
Author(s):  
Luis Eduardo Carmona ◽  
Niradiz Reyes ◽  
Farith González

Objectives: To detect the presence of Streptococcus mutans and Streptococcus sobrinus in dental plaque of children from Cartagena and correlate it to dental caries precavity stages, applying a standardized PCR-based technique for epidemiological purposes. Methods: Descriptive study using a non-probabilistic sample of 50 children between 3 and 5 years of age, preschoolers from a Caribbean population in Colombia. Criteria for selection were that children should exhibit plaque accumulations on the surface of the cervical margins of the rearmost molars, and placed in one of two study groups: carious lesions and sound surfaces. Dental plaque samples from both groups were subjected to molecular analysis and statistical analysis was applied to determine the difference between the two groups using the frequencies of presence of S. mutans, S. sobrinus or both in the two groups applying Fisher’s exact test for association between the presence of microorganisms and the state of the tooth surface from where the dental plaque was taken. Results: The frequency of S. mutans in carious lesions was 76% and 24% in healthy surfaces. The frequency of S. sobrinus in carious lesions was 81.9% and 18.1% in caries-free surfaces. There was statistical significance between the presence of S. mutans and the presence of caries (p=0.001) and between the presence of S. sobrinus (p=0.02) and the presence of caries. There was no statistical significance between the presence of caries and the simultaneous presence of both microorganisms (p=0.08). Conclusions: The presence of S. mutans and S. sobrinus in dental plaque samples is highly prevalent and associated to non cavitated carious lesions, being the molecular identification of these microorganisms by PCR a sensitive, fast, and easy to use detection method for the mutans group of oral bacteria.


2017 ◽  
Vol 84 (2) ◽  
Author(s):  
Xingqun Cheng ◽  
Sylvio Redanz ◽  
Nyssa Cullin ◽  
Xuedong Zhou ◽  
Xin Xu ◽  
...  

ABSTRACTCommensalStreptococcus sanguinisandStreptococcus gordoniiare pioneer oral biofilm colonizers. Characteristic for both is the SpxB-dependent production of H2O2, which is crucial for inhibiting competing biofilm members, especially the cariogenic speciesStreptococcus mutans. H2O2production is strongly affected by environmental conditions, but few mechanisms are known. Dental plaque pH is one of the key parameters dictating dental plaque ecology and ultimately oral health status. Therefore, the objective of the current study was to characterize the effects of environmental pH on H2O2production byS. sanguinisandS. gordonii.S. sanguinisH2O2production was not found to be affected by moderate changes in environmental pH, whereasS. gordoniiH2O2production declined markedly in response to lower pH. Further investigation into the pyruvate node, the central metabolic switch modulating H2O2or lactic acid production, revealed increased lactic acid levels forS. gordoniiat pH 6. The bias for lactic acid production at pH 6 resulted in concomitant improvement in the survival ofS. gordoniiat low pH and seems to constitute part of the acid tolerance response ofS. gordonii. Differential responses to pH similarly affect other oral streptococcal species, suggesting that the observed results are part of a larger phenomenon linking environmental pH, central metabolism, and the capacity to produce antagonistic amounts of H2O2.IMPORTANCEOral biofilms are subject to frequent and dramatic changes in pH.S. sanguinisandS. gordoniican compete with caries- and periodontitis-associated pathogens by generating H2O2. Therefore, it is crucial to understand howS. sanguinisandS. gordoniiadapt to low pH and maintain their competitiveness under acid stress. The present study provides evidence that certain oral bacteria respond to environmental pH changes by tuning their metabolic output in favor of lactic acid production, to increase their acid survival, while others maintain their H2O2production at a constant level. The differential control of H2O2production provides important insights into the role of environmental conditions for growth competition of the oral flora.


2019 ◽  
Vol 8 (41) ◽  
Author(s):  
Siew-Ging Gong ◽  
Yuki Chan ◽  
Céline M. Lévesque

Streptococcus salivarius strain LAB813 was isolated from the dental plaque biofilm of a caries-free child with healthy oral tissues. We report here the complete genome sequence of S. salivarius strain LAB813. This genome consists of a chromosome of 2.2 Mb and a megaplasmid, pSAL813, of 183 kb.


2017 ◽  
Vol 83 (11) ◽  
Author(s):  
Robert J. Palmer ◽  
Nehal Shah ◽  
Alex Valm ◽  
Bruce Paster ◽  
Floyd Dewhirst ◽  
...  

ABSTRACT Specific interbacterial adhesion, termed coaggregation, is well established for three early colonizers of the plaque biofilm: streptococci, actinomyces, and veillonellae. However, little is known about interactions of other early colonizers and about the extent of interactions within the bacterial community from a single host. To address these gaps, subject-specific culture collections from two individuals were established using an intraoral biofilm retrieval device. Molecular taxonomy (Human Oral Microbe Identification Microarray [HOMIM]) analysis of biofilm samples confirmed the integrity and completeness of the collections. HOMIM analysis verified the isolation of Streptococcus gordonii and S. anginosus from only one subject, as well as isolation of a previously uncultivated streptococcal phylotype from the other subject. Strains representative of clonal diversity within each collection were further characterized. Greater than 70% of these streptococcal strains from each subject coaggregated with at least one other coisolate. One-third of the strains carry a known coaggregation mediator: receptor polysaccharide (RPS). Almost all nonstreptococcal isolates coaggregated with other coisolates. Importantly, certain Rothia strains demonstrated more coaggregations with their coisolated bacteria than did any Streptococcus or Actinomyces strain, and certain Haemophilus isolates participated in twice as many. Confocal microscopy of undisturbed biofilms showed that Rothia and Haemophilus each occur in small multispecies microcolonies. However, in confluent high-biomass regions, Rothia occurred in islands whereas Haemophilus was distributed throughout. Together, the data demonstrate that coaggregation networks within an individual's oral microflora are extensive and that Rothia and Haemophilus can be important initiators of cell-cell interactions in the early biofilm. IMPORTANCE Extensive involvement of specific interbacterial adhesion in dental plaque biofilm formation has been postulated based on in vitro coaggregation between oral bacteria from culture collections that are not subject specific. In the present study, subject-specific culture collections were obtained from early plaque biofilm of two volunteers, and coaggregations within each culture collection were assayed. Coaggregations, several of which involved a coaggregation-mediating cell surface molecule known from well-studied streptococci, were widespread. Unexpectedly, the little-studied organisms Haemophilus and Rothia participated in the greatest numbers of interactions with community members; these two organisms showed different distributions within the undisturbed biofilm. The data show that coaggregation networks encompass most organisms within the biofilm community of each individual, and they indicate prominent participation of organisms such as Haemophilus and Rothia in early plaque biofilm formation.


2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Peter de Cock ◽  
Kauko Mäkinen ◽  
Eino Honkala ◽  
Mare Saag ◽  
Elke Kennepohl ◽  
...  

Objective. To provide a comprehensive overview of published evidence on the impact of erythritol, a noncaloric polyol bulk sweetener, on oral health.Methods. A literature review was conducted regarding the potential effects of erythritol on dental plaque (biofilm), dental caries, and periodontal therapy. The efficacy of erythritol on oral health was compared with xylitol and sorbitol.Results. Erythritol effectively decreased weight of dental plaque and adherence of common streptococcal oral bacteria to tooth surfaces, inhibited growth and activity of associated bacteria likeS. mutans, decreased expression of bacterial genes involved in sucrose metabolism, reduced the overall number of dental caries, and served as a suitable matrix for subgingival air-polishing to replace traditional root scaling.Conclusions. Important differences were reported in the effect of individual polyols on oral health. The current review provides evidence demonstrating better efficacy of erythritol compared to sorbitol and xylitol to maintain and improve oral health.


2021 ◽  
Vol 9 (2) ◽  
pp. 450
Author(s):  
Maigualida Cuenca ◽  
María Carmen Sánchez ◽  
Pedro Diz ◽  
Lucía Martínez-Lamas ◽  
Maximiliano Álvarez ◽  
...  

The aim of this study was to evaluate the potential anti-biofilm and antibacterial activities of Streptococcus downii sp. nov. To test anti-biofilm properties, Streptococcus mutans, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans were grown in a biofilm model in the presence or not of S. downii sp. nov. for up to 120 h. For the potential antibacterial activity, 24 h-biofilms were exposed to S. downii sp. nov for 24 and 48 h. Biofilms structures and bacterial viability were studied by microscopy, and the effect in bacterial load by quantitative polymerase chain reaction. A generalized linear model was constructed, and results were considered as statistically significant at p < 0.05. The presence of S. downii sp. nov. during biofilm development did not affect the structure of the community, but an anti-biofilm effect against S. mutans was observed (p < 0.001, after 96 and 120 h). For antibacterial activity, after 24 h of exposure to S. downii sp. nov., counts of S. mutans (p = 0.019) and A. actinomycetemcomitans (p = 0.020) were significantly reduced in well-structured biofilms. Although moderate, anti-biofilm and antibacterial activities of S. downii sp. nov. against oral bacteria, including some periodontal pathogens, were demonstrated in an in vitro biofilm model.


2011 ◽  
Vol 77 (15) ◽  
pp. 5394-5401 ◽  
Author(s):  
Emilie Lyautey ◽  
Amandine Cournet ◽  
Soizic Morin ◽  
Stéphanie Boulêtreau ◽  
Luc Etcheverry ◽  
...  

ABSTRACTElectroactivity is a property of microorganisms assembled in biofilms that has been highlighted in a variety of environments. This characteristic was assessed for phototrophic river biofilms at the community scale and at the bacterial population scale. At the community scale, electroactivity was evaluated on stainless steel and copper alloy coupons used both as biofilm colonization supports and as working electrodes. At the population scale, the ability of environmental bacterial strains to catalyze oxygen reduction was assessed by cyclic voltammetry. Our data demonstrate that phototrophic river biofilm development on the electrodes, measured by dry mass and chlorophyllacontent, resulted in significant increases of the recorded potentials, with potentials of up to +120 mV/saturated calomel electrode (SCE) on stainless steel electrodes and +60 mV/SCE on copper electrodes. Thirty-two bacterial strains isolated from natural phototrophic river biofilms were tested by cyclic voltammetry. Twenty-five were able to catalyze oxygen reduction, with shifts of potential ranging from 0.06 to 0.23 V, cathodic peak potentials ranging from −0.36 to −0.76 V/SCE, and peak amplitudes ranging from −9.5 to −19.4 μA. These isolates were diversified phylogenetically (Actinobacteria,Firmicutes,Bacteroidetes, andAlpha-,Beta-, andGammaproteobacteria) and exhibited various phenotypic properties (Gram stain, oxidase, and catalase characteristics). These data suggest that phototrophic river biofilm communities and/or most of their constitutive bacterial populations present the ability to promote electronic exchange with a metallic electrode, supporting the following possibilities: (i) development of electrochemistry-based sensors allowingin situphototrophic river biofilm detection and (ii) production of microbial fuel cell inocula under oligotrophic conditions.


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