Registered Nurses' Association of Ontario

Bacterial Biofilm

  • Bacterial biofilm is present in approximately 60 percent of chronic wounds.
  • Biofilm causes chronic inflammation and can prevent pressure injuries from healing.
  • Biofilm is microscopic and cannot be seen by the naked eye.
  • A wound swab is also unable to determine its presence.
  • Suspect bacterial biofilm in a pressure injury that:
  • has been present for more than four weeks,
  •  has not shown any signs of healing in the previous two weeks,
  • displays clinical signs and symptoms of inflammation, and/or
  • does not respond to antimicrobial therapy.
Clinical Management
Assessment and Management of Pressure Injuries for the Interprofessional Team, Third Edition
Point of Care Resources