Interaction of bacteria with cellular and hard surfaces

Oral diseases, such as gingivitis, periodontitis and caries are infectious diseases of the oral cavity in which oral biofilms play a causative role. Although, gum care and anti-bacterial technologies can be incorporated in toothpaste or mouthwash to improve the health and well-being of consumers, there are few technologies that work by preventing the adhesion of bacteria by physical means and thereby blocking initial biofilms and slow bacterial colonisation. Hygiene from personal care and home care products is a vital consumer benefit and is key to control transmission of communicable diseases in a home setting. Methods to measure microbial control, kill efficacy and survival in these niches are essential tools.

Caustics has successfully been used by Curran and Patterson to track and characterise the movement of synthetic and metallic nanoparticles as small as 3nm in an array of biologically relevant solutions under varying physiologically relevant temperature conditions and nanoparticle concentrations (Patterson and Whelan 2008,Coglitore 2017 and Giorgi 2019).

OBJECTIVES:
The aim of this project is to use caustic methodology to translate label-free tracking technology to support the development of pre-clinical in vitro testing systems that can characterise and quantify the adherence of bacteria and assess the effectiveness of anti-microbials. There will also be opportunity to use the technology to examine the effect of antimicrobials and novel coatings on hard surfaces and laundry treatments and to validate the technique against phages (proven to be visible via caustics), viruses and bacterial spores.
The proposal , and underlying science align with the BBSRC research priorities of transformative technologies, bioscience for an integrated understanding of health and combatting antimicrobial resistance, whilst the resultant experimental models will align with 3Rs, replacement, refinement and reduction in research using animals.

Bacteria are single-cell, prokaryotic, ubiquitous organisms that are both vital for maintaining the environment in which we live and can lead to the formation of biofilm which is the cause of many infectious diseases. Bacteria are transported to a surface either by structures that provide motility or by random, Brownian motion, governed by electrostatic and Van der Waals interactions in the surrounding fluid. At a surface, adhesion of a bacterium initiates the formation of a biofilm - a structured, self-organised community of bacteria and their extracellular polymeric substances (EPS). These ecosystems can grow on any synthetic or biological surface/interface exposed to external environments such as the surface of teeth, skin, kitchen countertops and bathroom surfaces. Specifically, oral biofilms are responsible for some of the most widespread infections - caries, gingivitis and periodontitis [1], as the surfaces of teeth, dentures and dental implants are highly susceptible to biofilm formation. Severe cases of these diseases can lead to more serious health complications such as bone loss or implant failure.
Developing real time label free cost-effective tracking technologies that can characterise and quantify the diffusion of synthetic and biological micro and nano-entities and their ability to adhere and/or infect a surface is a key tool in developing the next generation of anti-microbial therapies and surfaces. These technologies will allow investigations into anti-microbial efficiency both in solution and at the point of contact on a surface.
Several studies have attempted to track bacterial dynamics using single particle tacking techniques such as fluorescence microscopy, which is by far the most common single particle tracking technique. This approach requires a fluorescent label to be attached to the particle or organism being tracked. The exposure of the fluorescent label to the excitation light can cause the label to break down leading to photobleaching and phototoxicity,