PhD Studentship: The effects of ultrasonic treatment on bacterial biofilms

There is a current increase in the worldwide challenge of bacterial infection of wounds and ulcers of the skin. Treatment is usually based on antibiotic usage, however the global escalation in antibiotic resistance requires the development of novel or improved treatments. This project involves investigating the potential of therapeutic ultrasound as a novel antibacterial treatment. Ultrasound has been used in several studies in combination with antibiotics to treat infection both in vivo and in vitro. However, many bacteria in chronic wounds and the oral cavity are protected within bacterial communities known as biofilms.

Biofilm-forming bacteria are a particular problem since whilst living within the biofilm they are much more resistant to conventional antibacterial treatment, partly due to dormant ‘persister’ cells that have reduced metabolic activity, thus reducing available targets for antibiotics.

Previous work has shown that low frequency low intensity ultrasound treatment increases the growth of biofilms. We postulate that this is due to the ultrasonic activation of the dormant persister cells within the biofilm, allowing them to start dividing once more and thus becoming more sensitive to antimicrobial treatment.

The overall aim of this project is to investigate the potential of treating bacterial biofilms with ultrasound, in order to increase the efficacy of antimicrobials against persister cells within the biofilm. We will test our theory using planktonic and biofilm bacteria, both in culture and as part of 3D tissue engineered models of skin wound infection and infected 3D tissue engineered models of oral mucosa. We will also investigate some of the mechanisms of ultrasonic cell activation which are currently largely unknown. The project will involve practical work encompassing microbiology, cell culture, histology, tissue engineering, molecular biology, microscopy and sonochemistry.

Results from this work could help towards substantially reducing the dosage of antibiotics needed to treat many chronic wound infections.

Funding Notes

The Faculty Scholarships for Medicine, Dentistry & Health cover fees and stipend at Home/EU level. Overseas students may apply but will need to fund the fee differential between Home and Overseas rate from another source.