An investigation into the effects of prosthesis relevant surfaces on the formation of Staphylococcus aureus biofilms

The aim of this study was to investigate the effects prosthesis relevant surfaces and finishes have on the formation of Staphylococcus aureus (S. aureus) biofilms, the leading causative pathogenic bacteria of periprosthetic joint infection (PJI). Microbiological biofilm analysis was conducted to quantify S. aureus biofilm growth on prosthesis relevant surface coatings and finishes. Through the use of a CDC Biofilm Reactor (CDC-BR), biofilms were grown under constant shear conditions on three different titanium surface finishes, including Plasma Spray (PS), Grit Blasted (GB) and an As-fabricated (AF) surface used for comparative and control purposes. Advanced metrological techniques were applied to characterise each surface. This advanced approach to surface characterisation, including functional volume parameters has been carried out to provide a detailed quantifiable description of the surface and one that better relates to the nature of growth upon a surface. Results show that the PS surface exhibits a significant increase in biofilm growth in comparison to the GB and AF surfaces, with the AF surface showing the lowest amount of biofilm growth. Additionally, the morphology of the features of the PS coating allows for the biofilm accumulation to flourish in the re-entrant features across its topography. These findings highlight the difficulties of biofilm eradication and further complicate the design process of prosthetics, where features implemented to promote osseointegration simultaneously offer favourable locations for bacterial cell attachment and subsequent biofilm development, leading potentially, to PJI. There is a general consensus throughout literature regarding an apparent trend between an increase in Sa and an increase in biofilm formation (Zheng et al 2021 Frontiers in Bioengineering and Biotechnology 9 643722; Bridgens et al 2015 Surface and Coatings Technology 284; James et al 2019 Aesthetic Plast. Surg. 43 490–497). This study has shown that whilst this may generally be the case, the location of this surface area increase within the topography may be a more important observation.