Anti-infection strategies for biomaterials surfaces - not always about counting numbers of adhering microbes

摘要

Biomaterial-associated infection (BAI) is initiated by bacterial adhesion to an implant surface followed by production of extracellular polymeric matrix (EPS). EPS-production is a survival strategy, since it provides mechanical stability to the biofilm, resistance to antimicrobials and protection against the host immune system. As a consequence, BAI can mostly only be treated by implant replacement. To prevent BAI, reduction of initial bacterial adhesion has been a target of investigation. Promising option for decreasing numbers of adhering bacteria are polymer brush coatings, acting as steric barriers that prevent direct bacterial contact with a surface. However, reducing bacterial adhesion has limitations, since even adhesion of a small number of bacteria can lead to biofilm formation. Moreover, it can be doubted whether interference in bacterial adaptation to their adhering state would not be a better way to go, leaving bacteria in their susceptible planktonic state, also when adhering. Bacteria have only limited possibilities to sense a surface. Since bacteria are known to respond differently to different biomaterials, we hypothesize that adhering bacteria sense a surface through cell wall deformation under the influence of the prevailing adhesion forces as a first step in their adaptation to an adhering state and the formation of a biofilm. Research aimed at modifying the bacterial response upon adhesion to a surface in order to block bacterial transition from a 'planktonic" to a "biofilm" mode of growth may yield novel strategies to prevent BAI.