Spatial mapping of polymicrobial communities reveals a precise biogeography associated with human dental caries

Tooth decay (dental caries) is a widespread human disease caused by microbial biofilms.Streptococcus mutans, a biofilm-former, has been consistently associated with severe childhood caries; however, how this bacterium is spatially organized with other microorganisms in the oral cavity to promote disease remains unknown. Using intact biofilms formed on teeth of toddlers affected by caries, we discovered a unique 3D rotund-shaped architecture composed of multiple species precisely arranged in a corona-like structure with an inner core ofS. mutansencompassed by outer layers of other bacteria. This architecture creates localized regions of acidic pH and acute enamel demineralization (caries) in a mixed-species biofilm model on human teeth, suggesting this highly ordered community as the causative agent. Notably, the construction of this architecture was found to be an active process initiated by production of an extracellular scaffold byS. mutansthat assembles the corona cell arrangement, encapsulating the pathogen core. In addition, this spatial patterning creates a protective barrier against antimicrobials while increasing bacterial acid fitness associated with the disease-causing state. Our data reveal a precise biogeography in a polymicrobial community associated with human caries that can modulate the pathogen positioning and virulence potential in situ, indicating that micron-scale spatial structure of the microbiome may mediate the function and outcome of host–pathogen interactions.

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Models and Role Models

Caries Research ◽

10.1159/000380870 ◽

2015 ◽

Vol 49 (Suppl. 1) ◽

pp. 3-10 ◽

Cited By ~ 17

Author(s):

Jacob M. ten Cate

Keyword(s):

Dental Caries ◽

Role Models ◽

Oral Care ◽

Experimental Models ◽

Biofilm Model ◽

Information Models ◽

Bacterial Aetiology ◽

Ph Cycling ◽

Available Information

Developing experimental models to understand dental caries has been the theme in our research group. Our first, the pH-cycling model, was developed to investigate the chemical reactions in enamel or dentine, which lead to dental caries. It aimed to leverage our understanding of the fluoride mode of action and was also utilized for the formulation of oral care products. In addition, we made use of intra-oral (in situ) models to study other features of the oral environment that drive the de/remineralization balance in individual patients. This model addressed basic questions, such as how enamel and dentine are affected by challenges in the oral cavity, as well as practical issues related to fluoride toothpaste efficacy. The observation that perhaps fluoride is not sufficiently potent to reduce dental caries in the present-day society triggered us to expand our knowledge in the bacterial aetiology of dental caries. For this we developed the Amsterdam Active Attachment biofilm model. Different from studies on planktonic (‘single') bacteria, this biofilm model captures bacteria in a habitat similar to dental plaque. With data from the combination of these models, it should be possible to study separate processes which together may lead to dental caries. Also products and novel agents could be evaluated that interfere with either of the processes. Having these separate models in place, a suggestion is made to design computer models to encompass the available information. Models but also role models are of the utmost importance in bringing and guiding research and researchers.

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Physicochemical Studies of Enamel (I) Dye Penetration Into Enamel of Adult Human Teeth In Situ**From the Foundation for Dental Research of the Chicago College of Dental Surgery.

The Journal of the American Dental Association and The Dental Cosmos ◽

10.14219/jada.archive.1938.0060 ◽

1938 ◽

Vol 25 (2) ◽

pp. 223-227

Author(s):

Oscar Kanner

Keyword(s):

Human Teeth ◽

Dental Surgery ◽

Dental Research ◽

Dye Penetration ◽

Adult Human ◽

Physicochemical Studies

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Effect of Hydrogen Peroxide at 35% on the Morphology of Enamel and Interference in the De-remineralization Process: An In Situ Study

Operative Dentistry ◽

10.2341/11-112-l ◽

2012 ◽

Vol 37 (5) ◽

pp. 518-525 ◽

Cited By ~ 15

Author(s):

AM de Arruda ◽

PH dos Santos ◽

RH Sundfeld ◽

SB Berger ◽

ALF Briso

Keyword(s):

Hydrogen Peroxide ◽

Dental Caries ◽

Microscopic Analysis ◽

Enamel Surface ◽

In Situ Study ◽

Bovine Enamel ◽

Histologic Changes

SUMMARY This study evaluated the microhardness and histomorphology of bovine enamel when 35% hydrogen peroxide is used. A total of 44 specimens were adapted to removable devices used by 11 individuals subjected to dental caries challenge. A decrease in microhardness was observed for all groups after the cariogenic challenge. Microscopic analysis revealed that fragments subjected to cariogenic challenge associated with bleaching had more intense superficial histologic changes, but the depth of the lesions remained unchanged. It was concluded that 35% hydrogen peroxide enhanced the reduction in hardness and histomorphologic changes in the enamel surface exposed to cariogenic challenge.

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Regional hydrology controls stream microbial biofilms: evidence from a glacial catchment

Biogeosciences Discussions ◽

10.5194/bgd-1-497-2004 ◽

2004 ◽

Vol 1 (1) ◽

pp. 497-531 ◽

Cited By ~ 1

Author(s):

T. J. Battin ◽

A. Wille ◽

R. Psenner ◽

A. Richter

Keyword(s):

Landscape Heterogeneity ◽

Low Flow ◽

Detection Rates ◽

Stream Communities ◽

Stream Discharge ◽

Carbon Production ◽

Microbial Biofilms ◽

Short Period ◽

Alpine Stream

Abstract. Glaciers are highly responsive to global warming and important agents of landscape heterogeneity. While it is well established that glacial ablation and snowmelt regulate stream discharge, linkage among streams and streamwater hydrogeochemistry, the controls of these factors on stream microbial biofilms remain insufficiently understood. We investigated glacial (metakryal, hypokryal), groundwater-fed (krenal) and snow-fed (rhithral) streams – all of them representative for alpine stream networks – and present evidence that these hydrologic and hydrogeochemical factors differentially affect sediment microbial biofilms. Average microbial biomass and bacterial carbon production were low in the glacial streams, whereas bacterial cell size, biomass, and carbon production were higher in the tributaries, most notably in the krenal stream. Whole-cell in situ fluorescence hybridization revealed reduced detection rates of the Eubacteria and higher abundance of α-Proteobacteria in the glacial stream, a pattern that most probably reflects the trophic status of this ecosystem. Our data suggest low flow during the onset of snowmelt and autumn as a short period (hot moment) of favorable environmental conditions with pulsed inputs of allochthonous nitrate and dissolved organic carbon, and with disproportional high microbial growth. Krenal and rhithral streams with more constant and favorable environments serve as possible sources of microbes and organic matter to the main glacial channel during periods (e.g. snowmelt) of elevated hydrologic linkage among streams. Ice and snow dynamics have a crucial impact on microbial biofilms, and we thus need better understanding of the microbial ecology and enhanced consideration of critical hydrological episodes in future models predicting alpine stream communities.

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Novel Antibiofilm Non-Biocidal Strategies

Microorganisms in the Deterioration and Preservation of Cultural Heritage ◽

10.1007/978-3-030-69411-1_5 ◽

2021 ◽

pp. 117-136

Author(s):

Francesca Cappitelli ◽

Federica Villa

Keyword(s):

Control Strategies ◽

Model Systems ◽

Negative Effects ◽

Alternative Strategies ◽

Biofilm Model ◽

Biocidal Products ◽

Multiple Species ◽

Cultural Heritage Objects ◽

And Control ◽

By Products

AbstractSubaerial biofilm (SAB) formation on cultural heritage objects is often considered an undesirable process in which microorganisms and their by-products, e.g., enzymes and pigments, cause damage or alteration to a surface. Since biofilms are widespread phenomena, there has been a high demand for preventive and control strategies that resist their formation or reduce their negative effects once formed. Up to date, the main strategy to control biofilms has been the use of biocides. Because of their intrinsic properties, biocidal products can pose risks to humans, animals, and the environment. In this chapter, the authors call “green” only those alternative strategies to biocides able to prevent/control biofilms but that do not kill microorganisms, i.e., irrespective of the use of natural compounds. Here, we describe some of the methods that are most commonly used to test the effectiveness of antibiofilm compounds with multiple-species biofilm model systems. A unified terminology and well described protocols and guidelines are still required to compare and test the effectiveness of traditional or novel compounds against biofilms retrieved on heritage surfaces.

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Differential cytokeratin gene expression reveals early dorsal-ventral regionalization in chick mesoderm

Development ◽

10.1242/dev.110.2.417 ◽

1990 ◽

Vol 110 (2) ◽

pp. 417-425 ◽

Cited By ~ 2

Author(s):

T.S. Charlebois ◽

J.J. Henry ◽

R.M. Grainger

Keyword(s):

Gene Expression ◽

Spatial Patterning ◽

Germ Layer ◽

Dorsal Region ◽

Histological Differentiation ◽

Tissue Remodelling ◽

Early Step ◽

Present Evidence ◽

Hierarchical Manner

The induction and spatial patterning of early mesoderm are known to be critical events in the establishment of the vertebrate body plan. However, it has been difficult to define precisely the steps by which mesoderm is initially subdivided into functionally discrete regions. Here we present evidence for a sharply defined distinction between presumptive dorsal and presumptive ventral regions in early chick mesoderm. Northern blot and in situ hybridization analyses reveal that transcripts corresponding to CKse1, a cytokeratin gene expressed during early development, are present at high levels in the presumptive ventral mesoderm, but are greatly reduced or undetectable in the future dorsal region of mesoderm, where the formation of axial structures occurs later in development. This distinction is present even while the mesoderm layer is being formed, and persists during the extensive cellular movements and tissue remodelling associated with morphogenesis. These results point to an early step in which two fundamentally distinct states are established along the presumptive dorsal-ventral axis in the mesoderm, and suggest that determination in this germ layer occurs in a hierarchical manner, rather than by direct specification of individual types of histological differentiation. The differential expression of CKse1 represents the earliest molecular index of dorsoventral regionalization detected thus far in the mesoderm.

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