Stable isotope labelling of Staphylococcus aureus biofilms and planktonic cells

Antibiotic resistance is a Worldwide public health concern. Many of the antibiotics in current use are natural products, formed from bacteria or moulds to combat other microorganisms. In this project, we wish to use a new technique, desorption electrospray ionisation (DESI), coupled to mass spectrometry, to detect natural products on the surface of agar plates growing bacteria and fungi. DESI is able to scan the surfaces of samples without the need for prior preparation and extraction. This means that low abundance molecules, such as antibiotics, are less likely to be lost during sample preparation, leading to a greater potential to find new potential antibiotics. The methods developed in this project may also be applicable to other projects, such as in the medical humanities, where surface molecular analysis would be useful.