Invited Paper BP-SuA3
Engineering Serendipity: High-throughput Discovery of Materials that Resist Bacterial Attachment

Sunday, October 29, 2017, 3:40 pm, Room 22

Tackling medical device centred infection is an important part of meeting the global challenge of antimicrobial resistance. We focus on materials that resist bacterial attachment and biofilm formation rather than kill the cells, since it is anticipated that the selective pressure to develop antimicrobial resistance will be lower. High throughput screening has been used to discover a novel class of polymers with resistance to bacterial attachment and subsequent biofilm formation. [Hook et al. Nat.Biotech. 2012, Adv.Mats. 2013] In order to rationally design devices for medical application and others where biofilm formation is a challenge, we are developing a fundamental understanding of the processes involved in the interaction of bacterial cells with our lead materials.

Physicochemical descriptions of the surfaces have been found insufficient to predict bacterial attachment across diverse chemistries included in large polymer libraries, and therefore cannot offer an explanation of the controlling phenomena. Whilst perhaps disappointing for the physical sciences, the life sciences are replete with information on how bacteria respond to their local environment, with motility being one of the most readily observed processes. Microorganisms cannot be approximated to inert objects as they possess surface responsive appendages such as flagella, which enable them to swim, pili that confer twitching motility and fimbriae that mediate surface attachment. These in turn are coupled to sophisticated signal transduction mechanisms that facilitate integration of multiple local environmental parameters at both single cell and population levels. Many of these sensory systems are postulated to contribute to surface sensing.

We believe that bacterial decision-making is key to determining whether a surface is colonised or not-specifically in the early stages of bacterial-surface interactions preceding biofilm formation. I will present results from our optical microscopy investigations of how individual bacterial cells respond to surfaces using a novel microscope that collects temporal 3D information on cell position and surface tracking simultaneously achieved using DIC, TIRF and TIR microscopy. I will combine this information with our early efforts to characterise bacterial footprints and compare with literature for P. aeruginosa where the exopolysaccharide Psl guides surface exploration [Zhao et al Nature 2013]. Elucidation of the sensory pathways by which bacteria decide not to form biofilms on some surfaces is expected to have wide ranging impact in all areas where biofilms form.