Antimicrobial Effect of Nano-Rough Titanium Surfaces: Reduction of Microbial Adhesion and Mechanisms of Reduction
Final Report Abstract
In this project we investigated to what extent adhesion of the bacteria and protein adsorption to a surface depends on nano-roughness in the range of 2 - 16 nm. As important results we (i) established a general approach that allows reproducible production of stable nano-rough titanium surfaces with chemical and morphological similarity (OSIM) and (ii) found masking of the surface morphology by protein adsorption as insignificant. In order to measure the numbers of adherent bacteria and to investigate the bacterial genetic response, specially tailored assays for adhesion tests, image analysis and RNA isolation from sessile bacteria were established (HKI). Attachment of three E. coli strains with different adhesion behaviour to nano-rough surfaces was identified and studied. Surprisingly, (iii) no nano-roughness-dependent adhesion was observed, neither quantitatively nor genetically. However, (iv) transcriptome analyses clearly indicate bacterial surface sensing and a subsequent strain-specific genetic regulation of the adhesion. Adhesion force measurements, realized with C. albicans, hint towards an adhesion mechanism based on nano-contact points or accessible surface area, but wait to be transferred to and verified for E. coli. Summarized, our data suggest an individual, strain-driven adhesion mechanism without structural incompatibility between cell appendages and surface nano-features. Further investigations are underway to elucidate in more detail how individual bacterial strains attach to surfaces, which genes are involved and which general regulatory pathways are used. The results will then be applicable for interdisciplinary aspects of biomaterials in medicine. The here developed protocols and analyses present a toolbox for further research in nano-roughness regulated bacterial adhesion.
Publications
- Nanorough titanium surfaces reduce adhesion of Escherichia coli and Staphylococcus aureus via nano adhesion points. B Biointerfaces. Colloids and Surfaces B: Biointerfaces 2016; 145: 617-625
Lüdecke, C.; Roth, M.; Yu, W.; Horn, U.; Bossert, J.; Jandt, K. D.
(See online at https://doi.org/10.1016/j.colsurfb.2016.05.049) - (2020) Genome Sequence of Escherichia coli KI683, Isolated from a Urosepsis Patient, Microbiol. Resour. Announc., Bd. 9, Nr. 9, S. e01297-19
Stefani, N.; Schroeckh, V.; Neugebauer, U.; Bohnert, J.; Brakhage, A.A.
(See online at https://doi.org/10.1128/mra.01297-19) - Quantifying the relationship between surfaces‘ nanocontact point density and adhesion force of Candida albicans. Colloids and Surfaces B Biointerfaces 2020; 194: 111177
Dauben, T. J.; Dewald, C.; Firkowska-Boden, I.; Helbing, C.; Peisker, H.; Roth, M.; Bossert, J.; Jandt, K. D.
(See online at https://doi.org/10.1016/j.colsurfb.2020.111177)
