Berlin 2015 – wissenschaftliches Programm
MM 28.27: Poster
Dienstag, 17. März 2015, 18:30–20:30, Poster E
Hydrophobic interaction governs unspecific adhesion of staphylococci: a single cell force spectroscopy study — •Nicolas Thewes1, Peter Loskill1, Philipp Jung2, Henrik Peisker2, Markus Bischoff2, Mathias Herrmann2, and Karin Jacobs1 — 1Saarland University, Saarbrücken, Germany — 2Saarland University Hospital, Homburg/Saar, Germany
Unspecific adhesion of bacteria is usually the first step of biofilm formation on abiotic surfaces, yet it is unclear up to now which forces are governing this process. Alongside long-ranged van der Waals and electrostatic forces, short-ranged hydrophobic interaction plays an important role. To characterize the forces involved during approach and retraction of an individual bacterium to and from a surface, single cell force spectroscopy is applied: A single cell of the apathogenic species S. carnosus isolate TM300 is used as bacterial probe. With the exact same bacterium, hydrophobic and hydrophilic surfaces can be probed and compared. We find that as far as 50 nm from the surface, attractive forces can already be recorded, an indication of the involvement of long-ranged forces. Yet, comparing the surfaces of different surface energy, our results corroborate the model that large, bacterial cell wall proteins are responsible for adhesion, and that their interplay with the short-ranged hydrophobic interaction of the involved surfaces is mainly responsible for adhesion. The ostensibly long range of the attraction is a result of the large size of the cell wall proteins, searching for contact via hydrophobic interaction. The model also explains the strong (weak) adhesion of S. carnosus to hydrophobic (hydrophilic) surfaces.