The role of mechanics in biofilm formation

Biofilms are surface-bound communities of single-celled organisms that, collectively, have many characteristics more commonly associated with multicellular organisms. Biofilms are of great practical importance because they cause most persistent bacterial infections and can damage industry infrastructure.

In the standard model of biofilm development, biofilms begin when individual bacteria, formerly free-swimming, attach to a surface, somehow sense that they are on that surface, and adjust their gene expression accordingly.  It is this adjusted gene expression, combined with bacterial multiplication and accumulation on the surface, that eventually gives rise to a biofilm.

biolfilm_pseudomonas

Although we have recently called the standard model of biofilm development into question, it is undoubtedly true that single bacteria can sense surface attachment as a cue to begin biofilm development.  We have recently shown that bacteria “know” when they are attached to a surface by sensing mechanical shear stress.

The whole field of bacterial mechanosensing is in its infancy, and there are a great many unaddressed questions to be explored.  This contrasts strikingly with the well-developed field of eukaryotic mechanosensing.  Our primary focus now is to understand more about how bacteria sense and respond to the mechanics of the substrate to which they are attached, and how we could develop surface materials that prevent bacteria from getting the mechanical cue(s) that they need to “know” that it’s time to develop into a biofilm.  This is a new approach to biofilm prevention that would target a fundamental biological signaling mechanism and therefore, we hope, would be difficult for bacterial to evolve to circumvent.