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A peptide factor secreted by Staphylococcus pseudintermedius exhibits properties of both bacteriocins and virulence

Benedykt Wladyka1,2, Marcin Piejko1,3, Monika Bzowska4,2

  • 1Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland.

Scientific Reports
|September 29, 2015
PubMed

Insights

Researchers discovered BacSp222, a unique peptide from Staphylococcus pseudintermedius. This multifunctional peptide acts as both a bacteriocin and a virulence factor, impacting bacterial and eukaryotic cells.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Immunology

Background:

  • Staphylococcus pseudintermedius is an opportunistic pathogen in animals, with rising methicillin-resistant strains.
  • Gene transmission of antibiotic resistance between human and animal staphylococci is a growing concern.
  • Bacteriocins and virulence factors are typically considered distinct categories of microbial molecules.

Purpose of the Study:

  • To characterize a novel peptide, BacSp222, secreted by Staphylococcus pseudintermedius.
  • To investigate the dual functionality of BacSp222 as a potential bacteriocin and virulence factor.

Main Methods:

  • Isolation and characterization of the BacSp222 peptide from S. pseudintermedius strain 222.
  • Determination of peptide sequence, physicochemical properties, and genetic origin (plasmid-encoded).
  • Assessment of antimicrobial activity against Gram-positive bacteria and cytotoxicity against eukaryotic cells.
  • Evaluation of immunomodulatory effects on macrophage nitric oxide production.

Main Results:

  • BacSp222 is a novel, linear, 50-amino acid, highly cationic peptide with no significant sequence homology to known proteins.
  • The peptide exhibits potent bactericidal activity against Gram-positive bacteria at micromolar concentrations.
  • BacSp222 demonstrates cytotoxicity towards eukaryotic cells at slightly higher concentrations.
  • At nanomolar concentrations, BacSp222 enhances interferon gamma-induced nitric oxide release in murine macrophages.

Conclusions:

  • BacSp222 represents a unique multifunctional peptide with both antimicrobial and immunomodulatory properties.
  • This finding challenges the traditional separation of bacteriocins and virulence factors.
  • BacSp222 offers a potential new avenue for understanding host-pathogen interactions and developing novel therapeutic strategies.

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