Bacterial Colonization of Low‐Wettable Surfaces is Driven by Culture Conditions and Topography

Effect of surface low-wettability on bacterial colonization has become a prominent subject for the development of antibacterial coatings. However, bacteria\u0027s fate on such surfaces immersed in liquid as well as causal factors are poorly understood. We address this question by using a range of coatings with increasing hydrophobicity, to superhydrophobic, obtained by an atmospheric plasma polymer method allowing series production. Chemistry, wettability and topography are thoroughly described, as well as bacterial colonization by in situ live imaging up to 24h culture time in different liquid media. In the extreme case of superhydrophobic coating, substrates are significantly less colonized in biomolecules-poor liquids and for shortterm culture only. Complex statistical analysis demonstrates that bacterial colonization on these low-wettable substrates is predominantly controlled by the culture conditions and only secondary by topographic coating\u0027s properties (variation in surface structuration with almost constant mean height). Wettability is less responsible for bacterial colonization reduction in these conditions, but allows the coatings to preserve colonization-prevention properties in nutritive media when topography is masked by fouling. Even after long-term culture in rich medium, many large places of the superhydrophobic coating are completely free of bacteria in relation to their capacity to preserve air trapping.