Get access

Development of a novel ex vivo porcine skin explant model for the assessment of mature bacterial biofilms

Authors

  • Qingping Yang MS,

    1. Institute for Wound Research, Department of Obstetrics and Gynecology, University of Florida, Gainesville, Florida
    Search for more papers by this author
    • Qingping Yang and Priscilla L. Phillips contributed equally to this work and are considered joint first-authors.
  • Priscilla L. Phillips PhD,

    Corresponding author
    1. Center for Molecular Microbiology, Department of Oral Biology, University of Florida, Gainesville, Florida
    • Institute for Wound Research, Department of Obstetrics and Gynecology, University of Florida, Gainesville, Florida
    Search for more papers by this author
    • Qingping Yang and Priscilla L. Phillips contributed equally to this work and are considered joint first-authors.
  • Edith M. Sampson MS,

    1. Center for Molecular Microbiology, Department of Oral Biology, University of Florida, Gainesville, Florida
    Search for more papers by this author
  • Ann Progulske-Fox PhD,

    1. Center for Molecular Microbiology, Department of Oral Biology, University of Florida, Gainesville, Florida
    Search for more papers by this author
  • Shouguang Jin PhD,

    1. Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida
    Search for more papers by this author
  • Patrick Antonelli MD,

    1. Department of Otolaryngology, University of Florida, Gainesville, Florida
    Search for more papers by this author
  • Gregory S. Schultz PhD

    1. Institute for Wound Research, Department of Obstetrics and Gynecology, University of Florida, Gainesville, Florida
    Search for more papers by this author

Reprint requests:

Dr. Priscilla L. Phillips, University of Florida, PO Box 100424, Gainesville, FL 32610-0424, USA.

Tel: 352-273-7558;

Fax: 352-392-6994;

Email: prislp@ufl.edu

Abstract

Bacterial biofilms have been proposed to be a major factor contributing to the failure of chronic wounds to heal because of their increased tolerance to antimicrobial agents and the prolonged inflammation they cause. Phenotypic characteristics of bacterial biofilms vary depending on the substratum to which they attach, the nutritional environment, and the microorganisms within the biofilm community. To develop an ex vivo biofilm model that more closely mimics biofilms in chronic skin wounds, we developed an optimal procedure to grow mature biofilms on a central partial-thickness wound in 12-mm porcine skin explants. Chlorine gas produced optimal sterilization of explants while preserving histological properties of the epidermis and dermis. Pseudomonas aeruginosa and Staphylococcus aureus developed mature biofilms after 3 days that had dramatically increased tolerance to gentamicin and oxacillin (∼100× and 8,000× minimal inhibitory concentration, respectively) and to sodium hypochlorite (0.6% active chlorine). Scanning electron microscopy and confocal microscopy verified extensive exopolymeric biofilm structures on the explants. Despite a significant delay, a ΔlasI quorum-sensing mutant of P. aeruginosa developed biofilm as antibiotic-tolerant as wild-type after 3 days. This ex vivo model simulates growth of biofilms on skin wounds and provides an accurate model to assess effects of antimicrobial agents on mature biofilms.

Get access to the full text of this article

Ancillary