scholarly journals Non-Native Peptides Capable of Pan-Activating the agr Quorum Sensing System across Multiple Specificity Groups of Staphylococcus epidermidis

2021 ◽  
Author(s):  
Korbin H. J. West ◽  
Wenqi Shen ◽  
Emma L. Eisenbraun ◽  
Tian Yang ◽  
Joseph K. Vasquez ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Staphylococcus Epidermidis ◽  
Sensing System ◽  
Quorum Sensing System ◽  
Native Peptides

scholarly journals Role of the luxS Quorum-Sensing System in Biofilm Formation and Virulence of Staphylococcus epidermidis

2006 ◽  
Vol 74 (1) ◽  
pp. 488-496 ◽  
Author(s):  
Lin Xu ◽  
Hualin Li ◽  
Cuong Vuong ◽  
Viveka Vadyvaloo ◽  
Jianping Wang ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Mutant Strain ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Bacterial Pathogens ◽  
Sensing System ◽  
Autoinducer 2 ◽  
Enhanced Production ◽  
Quorum Sensing System ◽  
Biofilm Development

ABSTRACT Nosocomial infections caused by Staphylococcus epidermidis are characterized by biofilm formation on implanted medical devices. Quorum-sensing regulation plays a major role in the biofilm development of many bacterial pathogens. Here, we describe luxS, a quorum-sensing system in staphylococci that has a significant impact on biofilm development and virulence. We constructed an isogenic ΔluxS mutant strain of a biofilm-forming clinical isolate of S. epidermidis and demonstrated that luxS signaling is functional in S. epidermidis. The mutant strain showed increased biofilm formation in vitro and enhanced virulence in a rat model of biofilm-associated infection. Genetic complementation and addition of autoinducer 2-containing culture filtrate restored the wild-type phenotype, demonstrating that luxS repressed biofilm formation through a cell-cell signaling mechanism based on autoinducer 2 secretion. Enhanced production of the biofilm exopolysaccharide polysaccharide intercellular adhesin in the mutant strain is presumably the major cause of the observed phenotype. The agr quorum-sensing system has previously been shown to impact biofilm development and biofilm-associated infection in a way similar to that of luxS, although by regulation of different factors. Our study indicates a general scheme of quorum-sensing regulation of biofilm development in staphylococci, which contrasts with that observed in many other bacterial pathogens.

scholarly journals Staphylococcus epidermidis agr Quorum-Sensing System: Signal Identification, Cross Talk, and Importance in Colonization

2014 ◽  
Vol 196 (19) ◽  
pp. 3482-3493 ◽  
Author(s):  
M. E. Olson ◽  
D. A. Todd ◽  
C. R. Schaeffer ◽  
A. E. Paharik ◽  
M. J. Van Dyke ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Cross Talk ◽  
Staphylococcus Epidermidis ◽  
Signal Identification ◽  
Sensing System ◽  
Quorum Sensing System

#99: Streptococcus pyogenes Utilizes the Peptide-Based Rgg 2/3 Quorum Sensing System During Oropharyngeal Colonization

2021 ◽  
Vol 10 (Supplement_1) ◽  
pp. S10-S10
Author(s):  
Artemis Gogos ◽  
Michael J Federle
Keyword(s):  
Quorum Sensing ◽  
Streptococcus Pyogenes ◽  
Lymphoid Tissue ◽  
Transcriptional Activator ◽  
Rt Pcr ◽  
Sensing System ◽  
Bacterial Rna ◽  
Quorum Sensing System ◽  
Luciferase Reporters

Abstract Background Streptococcus pyogenes is a human-restricted pathogen most often found in the human nasopharynx. Multiple bacterial factors have been found to contribute to persistent colonization of this niche, and many of these factors are important in mucosal immunity and vaccine development. In this work, we infected mice intranasally with transcriptional regulator mutants of the Rgg2/3 quorum sensing (QS) system—a peptide-based signaling system conserved in all sequenced isolates of S. pyogenes. Methods Three-week-old CD1 mice were intranasally infected with ~107 CFU of S. pyogenes strain MGAS315. Calcium alginate throat swabs were used to monitor nasopharyngeal colonization by the bacteria over time. Luciferase reporters used alongside an IVIS camera were able to show quorum sensing activity levels after inoculation into the mouse nose. Bacterial RNA was isolated from the throat of the mice and quantitative RT–PCR was performed on the samples to corroborate the luciferase reporter data. The nasal-associated lymphoid tissue (NALT) was excised and its supernatants were subjected to 32-plex murine cytokine and chemokine analysis (Millipore). Results Deletion of the QS system’s transcriptional activator (Δrgg2) dramatically diminished the percentage of colonized mice. Deletion of the transcriptional repressor (Δrgg3) increased the percentage of colonized mice compared with wild type. Stimulation of the QS system using synthetic pheromones prior to inoculation did not significantly increase the percentage of animals colonized, indicating that activity of the QS system is responsive to conditions of the host nasopharynx. Mice inoculated with QS-dependent luciferase reporters were subjected to in vivo imaging and showed activation within 1 hour. Bacterial RNA extracted directly from oropharyngeal swabs and evaluated by quantitative RT–PCR subsequently confirmed QS upregulation within 1 hour of inoculation. In the nasal-associated lymphoid tissue (NALT), a muted inflammatory response to the Δrgg2 bacteria suggests that their rapid elimination fails to elicit the previously characterized response to intranasal inoculation of GAS. Conclusions Deletion of the Rgg2 transcriptional activator of the Rgg 2/3 quorum sensing system eliminates colonization of the murine nasopharynx and changes the transcriptional profile of the bacteria in this niche. An existing small-molecule inhibitor of the Rgg2/3 system was unable to inhibit QS activation in vivo, likely due to the suboptimal achievable doses; however, results of our study indicate inhibition of QS may diminish the oropharyngeal colonization of S. pyogenes and argue for further development.

Investigating the Quorum Sensing System in Halophilic Bacteria

2015 ◽  
pp. 189-207 ◽  
Author(s):  
Tommonaro Giuseppina ◽  
Abbamondi Gennaro Roberto ◽  
Toksoy Oner Ebru ◽  
Nicolaus Barbara
Keyword(s):  
Quorum Sensing ◽  
Halophilic Bacteria ◽  
Sensing System ◽  
Quorum Sensing System
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