Surface topographical factors influencing bacterial attachment

Substratum surface roughness is known to be one of the key factors in determining the extent of bacterial colonization. Understanding the way by which the substratum topography, especially at the nanoscale, mediates bacterial attachment remains ambiguous at best, despite the volume of work available on the topic. This is because the vast majority of bacterial attachment studies do not perform comprehensive topographical characterization analyses, and typically consider roughness parameters that describe only one aspect of the surface topography. The most commonly reported surface roughness parameters are average and root mean square (RMS) roughness (Ra and Rq respectively), which are both measures of the typical height variation of the surface. They offer no insights into the spatial distribution or shape of the surface features. Here, a brief overview of the current state of research on topography-mediated bacterial adhesion is presented, as well as an outline of the suite of roughness characterization parameters that are available for the comprehensive description of the surface architecture of a substratum. Finally, a set of topographical parameters is proposed as a new standard for surface roughness characterization in bacterial adhesion studies to improve the likelihood of identifying direct relationships between substratum topography and the extent of bacterial adhesion.