The Impact of Protein-Based Substrates on Biofilm Development and Disruption

Abstract Body: Aim: Many standardized methods, such as the Minimum Biofilm Eradication Concentration (MBEC) assay, overlook the impact of real-world factors such as proteinaceous compounds that have an important function in the development of biofilms and delayed wound healing. The aim of this project was to assess how protein-based substrates effect biofilm formation within the MBEC assay, and the subsequent susceptibility of the single-species biofilms to commercially available treatments and disinfectants. Method: Single-species biofilms were grown for 72 hours on treated and untreated surfaces according to SOP 536 to quantify the effect a preconditioning stage has on the development of biofilms and the MBEC of various treatments and disinfectants with and without protein. Results / Discussion:  A significant increase in biofilm formation and persistence of organisms ( >130x) was observed within the preconditioned group, when compared to the non-preconditioned group. The microenvironment within a wound, with adhesive proteinaceous substrates, provides a readily colonizable surface for bacterial attachment and biofilm formation. The proteinaceous substrate, often referred to as wound exudate, is composed of serum proteins such as fibrin and immunoglobulin, leukocytes, necrotic tissue, and waste products from the immune system. Chronic wounds that pertain high quantities of wound exudate represent and important challenge for health care professionals. These results highlight the benefits of customised testing which more readily reflects real-world scenarios. Conclusion: This project provides preliminary data to support real-world applications, a more customised approach to biofilm testing, and provides insight that may challenge previous findings deemed efficacious by the MBEC assay.