Primary Supervisor: Professor Paula Mendes, Department of Chemical Engineering
Secondary supervisor: Dr Tim Overton
PhD project title: Investigating the effect of nanoscale vibration cues on long-term bacterial adhesion
University of Registration: University of Birmingham
Bacteria have propensity to colonize abiotic surfaces, resulting in the formation of structured, multicellular communities known as biofilms. Biofilms are often responsible for human infections (e.g. on implants and urinary catheters), contamination of processed products such as food, clogging of pipes, reduction of heat transfer in heat exchangers and cooling towers and fouling of ship hulls causing increased fluid resistance and fuel consumption. Since they adversely affect so many human activities, prevention or eradication of biofilms has been a topic of intensive research over the past decades. Although progress has been made, strategies are still subject to limitations in terms of their long-term resistance to bacterial adhesion. For example, chemical antimicrobials can generate multidrug-resistant bacteria, with potentially devastating consequences for animal and human health.
Consequently, there is an urgent need for new strategies to prevent bacterial attachment to abiotic surfaces. Recent studies demonstrated that bacteria respond to mechanical stimuli, including the unique dynamic loading regimes induced by vibration, by modulating phenotypes such as surface adhesion, proliferation and virulence.[1-4] Furthermore, previous studies have provided evidence that man-made nanostructured surfaces, which also exist in nature, have a direct influence on bacterial cell attachment. However, such nanostructures behave as static interfaces. Thus, the question arises concerning the significance of providing such nanostructured surfaces with vibration to influence bacterial adhesion. In this line of reasoning, the project aims explore how sub- and supracellular vibrational stimuli are perceived and processed by bacteria and if vibration and nanoscale topography can act in synergy to induce superior anti-bacterial properties.
Surfaces will be constructed and characterised with features from the micrometre to the nanometre scale. The effect of the different structures and vibrational regimes on bacterial adhesion will be tested. Apart from exploring how bacteria respond to different sub- and supracellular vibrational stimuli, the project will investigate whether currently-known mechanotransduction systems are mediating bacterial responses to nanoscale vibration.
This project will open new avenues i) to combat biofouling of medical implants/devices, including urinary catheters that are resistant to colonisation, therefore reducing infections in hospitals; ii) to create antimicrobial surfaces for food processing to prevent spoilage or contamination of food and industrial equipment that resists bacterial attachment, which would increase process efficiency.
(1) Hazan, Z.; Zumeris, J.; Jacob, H.; Raskin, H.; Kratysh, G.; Vishnia, M.; Dror, N.; Barliya, T.; Mandel, M.; Lavie, G. Effective prevention of microbial biofilm formation on medical devices by low-energy surface acoustic waves. Antimicrob. Agents Chemother. 2006, 50, 4144-4152.
(2) Paces, W. R.; Holmes, H. R.; Vlaisavljevich, E.; Snyder, K. L.; Tan, E. L.; Rajachar, R. M.; Ong, K. G. Application of sub-micrometer vibrations to mitigate bacterial adhesion. J. Funct. Biomater. 2014, 5, 15-26.
(3) Murphy, M. F.; Edwards, T.; Hobbs, G.; Shepherd, J.; Bezombes, F. Acoustic vibration can enhance bacterial biofilm formation. J. Biosci. Bioeng. 2016, 122, 765-770.
(4) Robertson, S. N.; Campsie, P.; Childs, P. G.; Madsen, F.; Donnelly, H.; Henriquez, F. L.; Mackay, W. G.; Salmeron-Sanchez, M.; Tsimbouri, M. P.; Williams, C.; Dalby, M. J.; Reid, S. Control of cell behaviour through nanovibrational stimulation: nanokicking. Philos. Trans. R. Soc. A-Math. Phys. Eng. Sci. 2018, 376, 21.
(5) Michalska, M.; Gambacorta, F.; Divan, R.; Aranson, I. S.; Sokolov, A.; Noirot, P.; Laible, P. D. Tuning antimicrobial properties of biomimetic nanopatterned surfaces. Nanoscale 2018, 10, 6639-6650.
BBSRC Strategic Research Priority: Sustainable Agriculture and Food: Microbial Food Safety. Renewable Resources and Clean Growth: Industrial Biotechnology. Understanding the Rules of Life: Microbiology
Techniques that will be undertaken during the project:
Nanostructures will be created using soft lithography replica molding and the nanostructures will be characterised for morphology, composition and wettability using atomic force microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and contact angle. Bacterial adhesion will be analysed using standard microbiology techniques as well as microscopy (confocal laser scanning microscopy, Raman confocal microscopy, atomic force microscopy).
Contact: Professor Paula Mendes, University of Birmingham