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Quorum-sensing regulation in staphylococci-an overview.
Katherine Y Le1, Michael Otto2
1Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health Bethesda, MD, USA ; Division of Hospital Internal Medicine, Department of Medicine, Mayo Clinic College of Medicine Rochester, MN, USA.
Frontiers in Microbiology
|November 19, 2015
Summary
The accessory gene regulator (Agr) system controls Staphylococcus aureus virulence. Inhibiting Agr may combat acute infections and reduce chronic biofilm formation.
Area of Science:
- Microbiology
- Bacterial Pathogenesis
- Molecular Biology
Background:
- Staphylococci are common human bacteria, with Staphylococcus aureus being a significant pathogen.
- The accessory gene regulator (Agr) system governs bacterial cell density sensing and adaptive responses in staphylococci.
- Agr regulates virulence by modulating toxin and exoenzyme expression, and colonization factors.
Purpose of the Study:
- To elucidate the role of the Agr system in staphylococcal virulence and infection dynamics.
- To explore the potential of Agr inhibition as a therapeutic strategy against Staphylococcus aureus infections.
Main Methods:
- Analysis of Agr system function in regulating gene expression based on bacterial cell density.
- Investigation of the link between Agr activity and acute versus chronic infection phenotypes, including biofilm formation.
Main Results:
- The Agr system controls the switch between virulence factor production and colonization factors based on cell density.
- High Agr activity is linked to acute infections, while low activity is associated with chronic infections and biofilms.
- Agr's extracellular peptide signal, featuring a thiolactone structure, mediates these density-dependent responses.
Conclusions:
- The Agr system is a critical regulator of Staphylococcus aureus virulence, orchestrating the timing of pathogenic factor expression.
- Targeting the Agr system presents a promising therapeutic avenue for managing both acute and chronic Staphylococcus aureus infections.
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