News & Events
Bacterial interaction with nanostructured surfaces and adhesion-force triggered bacterial responses
Speaker(s): Prof. Henk J. Busscher and Prof. Henny C. van der Mei, Department of Biomedical Engineering, University of Groningen, The Netherlands
When: 18 January 2017 (4:00 - 5:00pm)
Where: SBS CR2 (Level 1)
Type: Seminars

Nanostructured surfaces are extensively considered with respect to their potential impact on bacterial adhesion from aqueous suspensions or air, but in real-life bacteria are often transmitted between surfaces. Mechanistically, transmission involves detachment of adhering bacteria from a donor and adhesion to a receiver surface, controlled by the relative values of the adhesion forces exerted by both surfaces.
We here first relate staphylococcal adhesion, detachment and transmission to, from, and between smooth and nanopillared-Si surfaces with staphylococcal adhesion forces. On smooth surfaces, the EPS producing strain adhered in higher numbers than the non-EPS producing strain. However, for each strain, the number of adhering bacteria remained similar on all nanopillared surfaces. Pressure-induced EPS production and cell death are new phenomena relating with the influence of adhesion forces exerted by different substrata on adhering bacteria, causing various degrees of cell wall deformation. Considering that many bacterial sensors are located in the cell membrane, this causes a trigger for adaptive responses of bacteria to their adhering state, explaining why biofilms of the same strain can have widely different emergent phenotypes including antibiotic resistance. 
Thus the (local, in case of nanostructured) force by which bacteria adhere to a surface is identified as a trigger, governing their adaptive responses and emergence of biofilm phenotypes. This must be accounted for in applications of nanostructured surfaces: whereas killing may be favorable, EPS production may reduce antimicrobial efficacy.