• COMMUNITY OF MICROBES

    Multiple species of bacteria and fungi living together.

  • ENTANGLED POLYMERS

    Microbes secrete a protective matrix called EPS (extracellular polymeric substance) made from polymers including proteins, glycolipids, polysaccharides and DNA.

  • METAL IONS

    Metal ions link polymers of the EPS, forming a resilient barrier.

Biofilm is a structured, surface-associated community of microorganisms, comprising a single species or, more commonly, multiple bacterial and fungal species. Microorganisms within a biofilm synthesise and secrete a protective extracellular polymeric substance (EPS), composed of proteins, glycolipids, polysaccharides and DNA. 

Metal ions cross-link the polymers of the EPS, forming a stable, resistant matrix. This structure attaches to both living surfaces (e.g., wounds, mucosal tissue) and non-living surfaces (e.g., implants, surgical hardware, catheters).

Clinical Significance

Biofilm is considered the dominant mode of microbial growth. It is estimated that approximately 80% of bacteria exist within biofilm communities, with the remaining 20% in a free-floating (planktonic) state.¹

This structure makes biofilm-embedded bacteria significantly harder to treat than the same bacteria on their own, for several reasons:

The EPS matrix physically blocks antibiotics and antiseptics. 

The protective layer restricts how far these agents can penetrate, so bacteria deep within the biofilm may never be exposed to a therapeutic dose.

The immune system struggles to reach them.

Immune cells that would normally identify and clear bacteria have limited access to organisms sheltered within the matrix.

Some bacteria "switch off." 

A portion of the bacteria within a biofilm become dormant, or metabolically inactive. Most antibiotics work by targeting actively growing and dividing cells, so dormant bacteria are largely unaffected by treatment - and can reactivate later.

Bacteria can share resistance with each other.

Within a biofilm, bacteria are able to exchange genetic material, including genes for antibiotic resistance, making the community as a whole more resilient over time.

Biofilm also presents a diagnostic challenge

Routine culturing techniques often struggle to detect biofilm-based bacteria. In one study of infected hip and knee replacements, standard culture failed to identify any bacteria in nearly half of the confirmed infections. When researchers applied a more sensitive genetic testing method to those same culture-negative cases, it detected a pathogen culture had missed in over 40% of them.³ This has direct implications for how infection is identified, managed and prevented in orthopaedic and implant surgery.

Approaches to Biofilm

Because the EPS matrix depends on metal ions to hold its structure together, one way to break down biofilm is to target those metal-ion bonds directly - freeing the bacteria within so they can be removed or become more vulnerable to treatment. Approaches built on this principle typically work in three stages:

  • Deconstruction

    Breaking down the EPS structure by removing the metal ions that hold its polymer strands together, causing the matrix to fall apart

  • Destruction

    Once exposed, bacterial cells are eliminated, commonly by disrupting the cell membrane or creating conditions the cell can't survive (for example, drawing water out of the cell until it collapses)

  • Defence

    Preventing the biofilm from reforming, so the treated area isn't simply recolonised

This three-part principle underlies surgical irrigation technologies such as XPERIENCE® Advanced Surgical Irrigation, part of the range Novus Surgical supplies in support of infection-prevention protocols.

Learn about XPERIENCE

Disclaimers

XPERIENCE is intended for use by healthcare professionals only. Full technical, clinical and safety documentation, including its ARTG entry and Instructions for Use, is available via the Resources page or through a Novus Surgical representative.

This page provides general scientific information regarding biofilm and is not intended as medical advice. It does not constitute a recommendation for the diagnosis, treatment or management of any condition. Clinical decisions regarding infection prevention should be made in consultation with a qualified healthcare professional.

References

  1. Penesyan A, et al. Three faces of biofilms: a microbial lifestyle, a nascent multicellular organism, and an incubator for diversity. NPJ Biofilms Microbiomes. 2021;7(1):80.
  2. Omar A, et al. Microbial Biofilms and Chronic Wounds. Microorganisms. 2017;5(1):9.
  3. Thoendel MJ, et al. Identification of Prosthetic Joint Infection Pathogens Using a Shotgun Metagenomics Approach. Clin Infect Dis. 2018;67(9):1333-1338.