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Papers by Cuong Vuong

Research paper thumbnail of The D-Alanine Residues of Staphylococcus aureus Teichoic Acids Alter the Susceptibility to Vancomycin and the Activity of Autolytic Enzymes

Antimicrobial Agents and Chemotherapy, 2000

Research paper thumbnail of Construction and Characterization of an agr Deletion Mutant of Staphylococcus epidermidis

Infection and Immunity, 2000

Research paper thumbnail of Impact of the agr Quorum‐Sensing System on Adherence to Polystyrene in Staphylococcus aureus

Journal of Infectious Diseases, 2000

Biofilm formation by Staphylococcus aureus is a serious problem in nosocomial infections. There a... more Biofilm formation by Staphylococcus aureus is a serious problem in nosocomial infections. There are great differences in the capacity of S. aureus to express biofilms, but the reasons are unknown. In all, 105 S. aureus strains were tested for a correlation between the agr quorum-sensing system phenotype and the ability of S. aureus to adhere to polystyrene. Some 78% of agr-negative, but only 6% of agr-positive, strains formed a biofilm, demonstrating a profound impact of agr on biofilm formation. This result was confirmed with defined agr mutants and by inhibition of agr with quorum-sensing blockers. The observed effect was not due to differential expression of the autolysin Atl or of the exopolysaccharide polysaccharide intercellular adhesin but seemed to be caused, at least in part, by the surfactant properties of delta-toxin. The detected biofilm-enhancing effect of S. aureus quorum-sensing blockers call into question the proposed therapeutic use of such substances.

Research paper thumbnail of Staphylococcus epidermidis Polysaccharide Intercellular Adhesin Production Significantly Increases during Tricarboxylic Acid Cycle Stress

Journal of Bacteriology, 2005

Research paper thumbnail of SaeR Binds a Consensus Sequence within Virulence Gene Promoters to Advance USA300 Pathogenesis

Journal of Infectious Diseases, 2010

Research paper thumbnail of Engagement of the Pathogen Survival Response Used by Group A Streptococcus to Avert Destruction by Innate Host Defense

Research paper thumbnail of The SaeR/S Gene Regulatory System Is Essential for Innate Immune Evasion by Staphylococcus aureus

Journal of Infectious Diseases, 2009

Research paper thumbnail of Control of antimicrobial peptide synthesis by the agr quorum sensing system in Staphylococcus epidermidis: activity of the lantibiotic epidermin is regulated at the level of precursor peptide processing

Research paper thumbnail of Identification of the sigB Operon in Staphylococcus epidermidis: Construction and Characterization of a sigB Deletion Mutant

Infection and Immunity, 2001

Research paper thumbnail of Role of the luxS Quorum-Sensing System in Biofilm Formation and Virulence of Staphylococcus epidermidis

Infection and Immunity, 2006

Research paper thumbnail of Inhibition of virulence factor expression in Staphylococcus aureus by the Staphylococcus epidermidis agr pheromone and derivatives

Febs Letters, 1999

The agr quorum-sensing system in Staphylococci controls the production of surface proteins and ex... more The agr quorum-sensing system in Staphylococci controls the production of surface proteins and exoproteins. In the pathogenic species Staphylococcus aureus, these proteins include many virulence factors. The extracellular signal of the quorum-sensing system is a thiolactone-containing peptide pheromone, whose sequence varies among the different staphylococcal strains. We demonstrate that a synthetic Staphylococcus epidermidis pheromone is a competent inhibitor of the Staphylococcus aureus agr system. Derivatives of the pheromone, in which the N-terminus or the cyclic bond structure was changed, were synthesized and their biological activity was determined. The presence of a correct N-terminus and a thiolactone were absolute prerequisites for an agr-activating effect in S. epidermidis, whereas inhibition of the S. aureus agr system was less dependent on the original structure. Our results show that effective quorum-sensing blockers that suppress the expression of virulence factors in S. aureus can be designed based on the S. epidermidis pheromone.

Research paper thumbnail of Quorum‐Sensing Control of Biofilm Factors in Staphylococcus epidermidis

Journal of Infectious Diseases, 2003

Research paper thumbnail of Staphylococcus epidermidis infections

Microbes and Infection, 2002

Research paper thumbnail of SarZ Is a Key Regulator of Biofilm Formation and Virulence in Staphylococcus epidermidis

Journal of Infectious Diseases, 2008

Research paper thumbnail of Regulated expression of pathogen-associated molecular pattern molecules in Staphylococcus epidermidis: quorum-sensing determines pro-inflammatory capacity and production of phenol-soluble modulins: Quorum sensing control of inflammation in S. epidermidis

Cellular Microbiology, 2004

Phenol-soluble modulin (PSM) is a peptide complex produced by the nosocomial pathogen Staphylococ... more Phenol-soluble modulin (PSM) is a peptide complex produced by the nosocomial pathogen Staphylococcus epidermidis that has a strong capacity to activate the human innate immune response. We developed a novel method based on liquid chromatography-mass spectrometry (LC-MS) to quantify the production of the individual PSM components. Each PSM peptide was abundant in most of the 76 S epidermidis strains tested. Importantly, none of the PSM components were secreted by an agr mutant strain, indicating that PSM synthesis is regulated strictly by the agr quorum-sensing system. Furthermore, the agr mutant strain failed to elicit production of TNFα by human myeloid cells and induced significantly less neutrophil chemotaxis compared with the wild-type strain. Thus, quorum-sensing in S. epidermidis dramatically influenced activation of human host defence. We propose that an agr quorum-sensing mechanism facilitates growth and survival in infected hosts by adapting production of the pro-inflammatory PSMs to the stage of infection.

Research paper thumbnail of Inducible expression and cellular location of AgrB, a protein involved in the maturation of the staphylococcal quorum-sensing pheromone

Archives of Microbiology, 2000

AgrB has been suggested to be responsible for the posttranslational modification in staphylococci... more AgrB has been suggested to be responsible for the posttranslational modification in staphylococci that leads to the production of the thiolactone-containing agr peptide pheromone. We demonstrate that AgrB is located in the cytoplasmic membrane. Vectors were constructed for the xylose-inducible overexpression of agrB, and of agrB and agrD together. A Staphylococcus epidermidis strain deleted for agr and containing these vectors was assayed for AgrB protein and pheromone production. The lack of adequate pheromone production suggests the involvement of additional factors in the production of the agr pheromone.

Research paper thumbnail of Conversion of Staphylococcus epidermidis Strains from Commensal to Invasive by Expression of the ica Locus Encoding Production of Biofilm Exopolysaccharide

Infection and Immunity, 2005

Research paper thumbnail of Characterization of the Staphylococcus epidermidis Accessory-Gene Regulator Response: Quorum-Sensing Regulation of Resistance to Human Innate Host Defense

Journal of Infectious Diseases, 2006

Research paper thumbnail of Key role of poly-γ-dl-glutamic acid in immune evasion and virulence of Staphylococcus epidermidis

Journal of Clinical Investigation, 2005

Research paper thumbnail of Development of Real‐Time In Vivo Imaging of Device‐Related Staphylococcus epidermidis Infection in Mice and Influence of Animal Immune Status on Susceptibility to Infection

Journal of Infectious Diseases, 2008

Research paper thumbnail of The D-Alanine Residues of Staphylococcus aureus Teichoic Acids Alter the Susceptibility to Vancomycin and the Activity of Autolytic Enzymes

Antimicrobial Agents and Chemotherapy, 2000

Research paper thumbnail of Construction and Characterization of an agr Deletion Mutant of Staphylococcus epidermidis

Infection and Immunity, 2000

Research paper thumbnail of Impact of the agr Quorum‐Sensing System on Adherence to Polystyrene in Staphylococcus aureus

Journal of Infectious Diseases, 2000

Biofilm formation by Staphylococcus aureus is a serious problem in nosocomial infections. There a... more Biofilm formation by Staphylococcus aureus is a serious problem in nosocomial infections. There are great differences in the capacity of S. aureus to express biofilms, but the reasons are unknown. In all, 105 S. aureus strains were tested for a correlation between the agr quorum-sensing system phenotype and the ability of S. aureus to adhere to polystyrene. Some 78% of agr-negative, but only 6% of agr-positive, strains formed a biofilm, demonstrating a profound impact of agr on biofilm formation. This result was confirmed with defined agr mutants and by inhibition of agr with quorum-sensing blockers. The observed effect was not due to differential expression of the autolysin Atl or of the exopolysaccharide polysaccharide intercellular adhesin but seemed to be caused, at least in part, by the surfactant properties of delta-toxin. The detected biofilm-enhancing effect of S. aureus quorum-sensing blockers call into question the proposed therapeutic use of such substances.

Research paper thumbnail of Staphylococcus epidermidis Polysaccharide Intercellular Adhesin Production Significantly Increases during Tricarboxylic Acid Cycle Stress

Journal of Bacteriology, 2005

Research paper thumbnail of SaeR Binds a Consensus Sequence within Virulence Gene Promoters to Advance USA300 Pathogenesis

Journal of Infectious Diseases, 2010

Research paper thumbnail of Engagement of the Pathogen Survival Response Used by Group A Streptococcus to Avert Destruction by Innate Host Defense

Research paper thumbnail of The SaeR/S Gene Regulatory System Is Essential for Innate Immune Evasion by Staphylococcus aureus

Journal of Infectious Diseases, 2009

Research paper thumbnail of Control of antimicrobial peptide synthesis by the agr quorum sensing system in Staphylococcus epidermidis: activity of the lantibiotic epidermin is regulated at the level of precursor peptide processing

Research paper thumbnail of Identification of the sigB Operon in Staphylococcus epidermidis: Construction and Characterization of a sigB Deletion Mutant

Infection and Immunity, 2001

Research paper thumbnail of Role of the luxS Quorum-Sensing System in Biofilm Formation and Virulence of Staphylococcus epidermidis

Infection and Immunity, 2006

Research paper thumbnail of Inhibition of virulence factor expression in Staphylococcus aureus by the Staphylococcus epidermidis agr pheromone and derivatives

Febs Letters, 1999

The agr quorum-sensing system in Staphylococci controls the production of surface proteins and ex... more The agr quorum-sensing system in Staphylococci controls the production of surface proteins and exoproteins. In the pathogenic species Staphylococcus aureus, these proteins include many virulence factors. The extracellular signal of the quorum-sensing system is a thiolactone-containing peptide pheromone, whose sequence varies among the different staphylococcal strains. We demonstrate that a synthetic Staphylococcus epidermidis pheromone is a competent inhibitor of the Staphylococcus aureus agr system. Derivatives of the pheromone, in which the N-terminus or the cyclic bond structure was changed, were synthesized and their biological activity was determined. The presence of a correct N-terminus and a thiolactone were absolute prerequisites for an agr-activating effect in S. epidermidis, whereas inhibition of the S. aureus agr system was less dependent on the original structure. Our results show that effective quorum-sensing blockers that suppress the expression of virulence factors in S. aureus can be designed based on the S. epidermidis pheromone.

Research paper thumbnail of Quorum‐Sensing Control of Biofilm Factors in Staphylococcus epidermidis

Journal of Infectious Diseases, 2003

Research paper thumbnail of Staphylococcus epidermidis infections

Microbes and Infection, 2002

Research paper thumbnail of SarZ Is a Key Regulator of Biofilm Formation and Virulence in Staphylococcus epidermidis

Journal of Infectious Diseases, 2008

Research paper thumbnail of Regulated expression of pathogen-associated molecular pattern molecules in Staphylococcus epidermidis: quorum-sensing determines pro-inflammatory capacity and production of phenol-soluble modulins: Quorum sensing control of inflammation in S. epidermidis

Cellular Microbiology, 2004

Phenol-soluble modulin (PSM) is a peptide complex produced by the nosocomial pathogen Staphylococ... more Phenol-soluble modulin (PSM) is a peptide complex produced by the nosocomial pathogen Staphylococcus epidermidis that has a strong capacity to activate the human innate immune response. We developed a novel method based on liquid chromatography-mass spectrometry (LC-MS) to quantify the production of the individual PSM components. Each PSM peptide was abundant in most of the 76 S epidermidis strains tested. Importantly, none of the PSM components were secreted by an agr mutant strain, indicating that PSM synthesis is regulated strictly by the agr quorum-sensing system. Furthermore, the agr mutant strain failed to elicit production of TNFα by human myeloid cells and induced significantly less neutrophil chemotaxis compared with the wild-type strain. Thus, quorum-sensing in S. epidermidis dramatically influenced activation of human host defence. We propose that an agr quorum-sensing mechanism facilitates growth and survival in infected hosts by adapting production of the pro-inflammatory PSMs to the stage of infection.

Research paper thumbnail of Inducible expression and cellular location of AgrB, a protein involved in the maturation of the staphylococcal quorum-sensing pheromone

Archives of Microbiology, 2000

AgrB has been suggested to be responsible for the posttranslational modification in staphylococci... more AgrB has been suggested to be responsible for the posttranslational modification in staphylococci that leads to the production of the thiolactone-containing agr peptide pheromone. We demonstrate that AgrB is located in the cytoplasmic membrane. Vectors were constructed for the xylose-inducible overexpression of agrB, and of agrB and agrD together. A Staphylococcus epidermidis strain deleted for agr and containing these vectors was assayed for AgrB protein and pheromone production. The lack of adequate pheromone production suggests the involvement of additional factors in the production of the agr pheromone.

Research paper thumbnail of Conversion of Staphylococcus epidermidis Strains from Commensal to Invasive by Expression of the ica Locus Encoding Production of Biofilm Exopolysaccharide

Infection and Immunity, 2005

Research paper thumbnail of Characterization of the Staphylococcus epidermidis Accessory-Gene Regulator Response: Quorum-Sensing Regulation of Resistance to Human Innate Host Defense

Journal of Infectious Diseases, 2006

Research paper thumbnail of Key role of poly-γ-dl-glutamic acid in immune evasion and virulence of Staphylococcus epidermidis

Journal of Clinical Investigation, 2005

Research paper thumbnail of Development of Real‐Time In Vivo Imaging of Device‐Related Staphylococcus epidermidis Infection in Mice and Influence of Animal Immune Status on Susceptibility to Infection

Journal of Infectious Diseases, 2008

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