Effect of topography on surface colonization by Pseudomonas aeruginosa

The MC2 team at LIPhy conducts interdisciplinary research at the interface of mechanics, physics, and life sciences, using experimental and theoretical approaches at different scales. The aim of this project is to use a microfluidic platform developed within the team to study surface contamination by an opportunistic pathogen (Pseudomonas aeruginosa). When colonizing surfaces, these bacteria can form collective structures called biofilms. These biofilms play a central role in their survival: they offer protection against physical and chemical stresses  and facilitate the exchange of genetic information between strains. Current experimental protocols are mainly based on smooth artificial surfaces, which provide good control over experimental conditions. However, real contaminated surfaces are rough, which limits the representativeness of existing models. 

To simulate real-life conditions, our team has developed a platform that allows us to simultaneously control chemistry, rigidity, and surface topography (see Figure 1). In this project, we aim to understand the interaction of a bacterium (Pseudomonas aeruginosa) exhibiting “twitching” motility with obstacles of different sizes and at different concentrations on a surface. First, we will characterize the surface and model the interaction of an individual bacterium with an obstacle under fixed experimental conditions, and then attempt to link this to the observed collective phenotype. In a second step, we will examine the consequences of these interactions on the mixture of strains, the expression of extracellular matrix, the use of other pathogens, and variations in the physicochemical properties of the surface.