Extracellular polymeric substance (EPS)-degrading enzymes reduce staphylococcal surface attachment and biocide resistance on pig skin in vivo

PLoS One. 2018 Oct 10;13(10):e0205526. doi: 10.1371/journal.pone.0205526. eCollection 2018.

Abstract

Staphylococcal extracellular polymeric substances (EPS) such as extracellular DNA (eDNA) and poly-N-acetylglucosamine surface polysaccharide (PNAG) mediate numerous virulence traits including host colonization and antimicrobial resistance. Previous studies showed that EPS-degrading enzymes increase staphylococcal biocide susceptibility in vitro and in vivo, and decrease virulence in animal models. In the present study we tested the effect of EPS-degrading enzymes on staphylococcal skin colonization and povidone iodine susceptibility using a novel in vivo pig model that enabled us to colonize and treat 96 isolated areas of skin on a single animal in vivo. To quantitate skin colonization, punch biopsies of colonized areas were homogenized, diluted, and plated on agar for colony forming unit enumeration. Skin was colonized with either Staphylococcus epidermidis or Staphylococcus aureus. Two EPS-degrading enzymes, DNase I and the PNAG-degrading enzyme dispersin B, were employed. Enzymes were tested for their ability to inhibit skin colonization and detach preattached bacteria. The effect of enzymes on the susceptibility of preattached S. aureus to killing by povidone iodine was also measured. We found that dispersin B significantly inhibited skin colonization by S. epidermidis and detached preattached S. epidermidis cells from skin. A cocktail of dispersin B and DNase I detached preattached S. aureus cells from skin and increased their susceptibility to killing by povidone iodine. These findings suggest that staphylococcal EPS components such as eDNA and PNAG contribute to skin colonization and biocide resistance in vivo. EPS-degrading enzymes may be a useful adjunct to conventional skin antisepsis procedures in order to further reduce skin bioburden.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology*
  • Bacterial Adhesion / drug effects
  • Bacterial Adhesion / physiology
  • Deoxyribonuclease I / pharmacology
  • Disease Models, Animal
  • Drug Resistance, Bacterial / drug effects
  • Drug Resistance, Bacterial / physiology
  • Extracellular Polymeric Substance Matrix / drug effects*
  • Extracellular Polymeric Substance Matrix / enzymology
  • Female
  • Humans
  • Povidone-Iodine / pharmacology*
  • Recombinant Proteins / pharmacology
  • Staphylococcal Skin Infections / drug therapy*
  • Staphylococcal Skin Infections / enzymology
  • Staphylococcal Skin Infections / pathology
  • Staphylococcus aureus*
  • Staphylococcus epidermidis*
  • Sus scrofa

Substances

  • Anti-Bacterial Agents
  • Recombinant Proteins
  • Povidone-Iodine
  • Deoxyribonuclease I

Grants and funding

Research reported in this publication was supported by the National Institute of Allergy and Infectious Disease of the National Institutes of Health under award number AI097182 (to J.B.K.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.