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Norspermidine changes the basic structure of S. mutans biofilm
1Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Provincial Key Laboratory of Stomatology, Sun Yat‑sen University, Guangzhou, Guangdong 510055, P.R. China.
Molecular Medicine Reports
|December 7, 2016
Summary
Norspermidine inhibits Streptococcus mutans biofilm formation by affecting cell viability and altering biofilm structure. This unusual polyamine impacts bacteria-exopolysaccharide units and quorum-sensing systems, revealing new insights into biofilm assembly.
Area of Science:
- Microbiology
- Biochemistry
- Molecular Biology
Background:
- The assembly of Streptococcus mutans biofilm structure is not fully understood.
- Polyamines are crucial for biofilm formation in some bacteria, but the role of norspermidine in S. mutans is unknown.
Purpose of the Study:
- To investigate the impact of norspermidine on Streptococcus mutans biofilm formation and structure.
- To elucidate the role of norspermidine in regulating biofilm assembly.
Main Methods:
- Biofilm architecture analysis in the presence and absence of norspermidine.
- Assessment of cell viability and exopolysaccharide (EPS) composition.
- Gene-expression microarray analysis to identify affected regulatory pathways.
Main Results:
- Norspermidine significantly inhibited S. mutans biofilm formation at 5 mM concentration.
- The study identified bacteria-exopolysaccharide units (BEUs) as the basic structural units of S. mutans biofilms.
- Norspermidine altered EPS architecture and downregulated quorum-sensing system components (2.7–15-fold).
Conclusions:
- Bacteria-exopolysaccharide units (BEUs) are fundamental to S. mutans biofilm structure and assembly.
- Quorum-sensing systems are major regulators of BEU assembly.
- Norspermidine disrupts S. mutans biofilm structure by influencing the quorum-sensing system and reducing cell viability.
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