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Interactions of methicillin resistant Staphylococcus aureus USA300 and Pseudomonas aeruginosa in polymicrobial wound

Irena Pastar1, Aron G Nusbaum, Joel Gil

  • 1Department of Dermatology and Cutaneous Surgery, Wound Healing and Regenerative Medicine Research Program, University of Miami Miller School of Medicine, Miami, Florida, United States of America.

Plos One
|March 2, 2013
PubMed

Insights

Polymicrobial wound infections with Staphylococcus aureus and Pseudomonas aeruginosa significantly delay healing. Pseudomonas aeruginosa enhances Staphylococcus aureus virulence, increasing infection severity.

Area of Science:

  • Microbiology
  • Wound Healing Research
  • Infectious Diseases

Background:

  • Staphylococcus aureus and Pseudomonas aeruginosa are common causes of difficult-to-heal wound infections.
  • Methicillin-resistant S. aureus USA300 is a significant pathogen in community-associated infections.
  • Polymicrobial infections complicate treatment due to bacterial interactions and resistance.

Purpose of the Study:

  • To investigate the synergistic effects of Staphylococcus aureus USA300 and Pseudomonas aeruginosa in a polymicrobial wound infection model.
  • To understand the impact of these bacteria on wound re-epithelialization and virulence factor expression.

Main Methods:

  • Utilized a porcine partial thickness wound healing model.
  • Studied mixed-species biofilms in vitro and in vivo.
  • Analyzed wound re-epithelialization and bacterial growth.
  • Measured the expression of Staphylococcus aureus virulence factors.

Main Results:

  • Mixed-species biofilms significantly delayed wound re-epithelialization by suppressing keratinocyte growth factor 1.
  • Pseudomonas aeruginosa inhibited Staphylococcus aureus growth in vitro but co-existed in vivo.
  • Pseudomonas aeruginosa induced the expression of Staphylococcus aureus virulence factors Panton-Valentine leukocidin and α-hemolysin.

Conclusions:

  • Bacterial interactions within polymicrobial biofilms in vivo are crucial for wound infection pathology.
  • Pseudomonas aeruginosa contributes to the severity of Staphylococcus aureus wound infections by upregulating virulence factors.
  • Understanding these interactions is key to developing effective treatments for complex wound infections.

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