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Bile Salt-induced Biofilm Formation in Enteric Pathogens: Techniques for Identification and Quantification
Published on: May 6, 2018
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Exopolysaccharides regulate calcium flow in cariogenic biofilms.
Monika Astasov-Frauenhoffer1, Muth M Varenganayil1, Alan W Decho2
1Department of Preventive Dentistry and Oral Microbiology, University Center for Dental Medicine, University of Basel, Basel, Switzerland.
Plos One
|October 13, 2017
Summary
Dental plaque
Area of Science:
- Oral microbiology
- Biochemistry
- Dental research
Background:
- Caries-associated biofilms cause calcium loss from teeth.
- Exopolysaccharides (EPS) form biofilm matrices and bind molecules.
- The calcium-binding role of EPS in cariogenic biofilms is not fully understood.
Purpose of the Study:
- Investigate calcium dissolution and tolerance in caries-associated microbes.
- Examine EPS properties and quantify calcium-binding affinity.
Main Methods:
- Measured calcium dissolution using Pikovskaya's agar.
- Assessed calcium tolerance via isothermal microcalorimetry (IMC).
- Identified functional groups using FTIR and acid-base titration.
- Quantified calcium binding affinity using isothermal titration calorimetry (ITC).
Main Results:
- Lactobacillus spp. and mutans streptococci showed calcium dissolution.
- High dissolution rates correlated with increased calcium tolerance (IMC).
- Acidic functional groups in EPS were identified as primary calcium binding sites.
- EPS exhibited higher calcium-binding affinity than lactic acid (ITC).
Conclusions:
- EPS plays a key role in cariogenic microbiota's calcium tolerance.
- EPS regulates free calcium concentrations within biofilms.
- This self-regulation is a mechanism in dental caries pathogenesis.
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