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Updated: May 24, 2026
Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
Published on: May 8, 2013
Novel phenol-soluble modulin derivatives in community-associated methicillin-resistant Staphylococcus aureus
David J Gonzalez1, Cheryl Y Okumura, Andrew Hollands
1Department of Pediatrics, University of California at San Diego, La Jolla, California 92093, USA.
Abstract:
Staphylococcus aureus causes a wide range of human disease ranging from localized skin and soft tissue infections to potentially lethal systemic infections. S. aureus has the biosynthetic ability to generate numerous virulence factors that assist in circumventing the innate immune system during disease pathogenesis. Recent studies have uncovered a set of extracellular peptides produced by community-associated methicillin-resistant S. aureus (CA-MRSA) with homology to the phenol-soluble modulins (PSMs) from Staphylococcus epidermidis. CA-MRSA PSMs contribute to skin infection and recruit and lyse neutrophils, and truncated versions of these peptides possess antimicrobial activity. In this study, novel CA-MRSA PSM derivatives were discovered by the use of microbial imaging mass spectrometry. The novel PSM derivatives are compared with their parent full-length peptides for changes in hemolytic, cytolytic, and neutrophil-stimulating activity. A potential contribution of the major S. aureus secreted protease aureolysin in processing PSMs is demonstrated. Finally, we show that PSM processing occurs in multiple CA-MRSA strains by structural confirmation of additional novel derivatives. This work demonstrates that IMS can serve as a useful tool to go beyond genome predictions and expand our understanding of the important family of small peptide virulence factors.
Insights
Researchers discovered novel Staphylococcus aureus peptides (PSMs) using imaging mass spectrometry. These findings reveal new insights into how these bacterial virulence factors function and are processed, potentially leading to new therapeutic strategies.
Area of Science:
- Microbiology
- Infectious Diseases
- Biochemistry
Background:
- Staphylococcus aureus is a significant human pathogen responsible for diverse infections.
- S. aureus produces virulence factors, including phenol-soluble modulins (PSMs), to evade the immune system.
- Community-associated methicillin-resistant S. aureus (CA-MRSA) PSMs are implicated in skin infections and immune cell interactions.
Purpose of the Study:
- To discover novel CA-MRSA PSM derivatives.
- To compare the hemolytic, cytolytic, and neutrophil-stimulating activities of novel PSM derivatives with their parent peptides.
- To investigate the role of aureolysin in PSM processing.
Main Methods:
- Microbial imaging mass spectrometry (IMS) was employed to identify novel CA-MRSA PSM derivatives.
- Comparative analysis of full-length PSMs and their derivatives for biological activities.
- Assessment of aureolysin's contribution to PSM processing.
Main Results:
- Novel CA-MRSA PSM derivatives were identified using IMS.
- PSM derivatives exhibited altered hemolytic, cytolytic, and neutrophil-stimulating activities compared to full-length PSMs.
- Evidence suggests aureolysin plays a role in processing PSMs, and this processing occurs across multiple CA-MRSA strains.
Conclusions:
- IMS is a valuable tool for discovering small peptide virulence factors beyond genomic predictions.
- PSM processing by bacterial proteases generates derivatives with potentially distinct biological activities.
- Understanding PSM processing enhances our knowledge of S. aureus pathogenesis and virulence.
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