Engineering drug sensitivity to screen for new classes of antibiotics for the emerging, drug resistant fungal pathogen Candida auris
This is a 4-year CASE studentship based at King’s College London and the laboratories of the Industrial partner, Public Health England in Salisbury.
The project features a multi-disciplinary approach that addresses the threat posed by an emerging fungal pathogen, Candida auris. Alarmingly, within only seven years this multi-drug resistant pathogen has become widespread across numerous countries, including the UK. These issues are now in the public domain http://www.bbc.co.uk/news/health-44160730
Only one new class of antifungal drugs has reached the clinic in the last 30 years. This, added to frequency of nosocomial fungal infections having risen sharply over the past few decades, means that there is a pressing need for new broad antifungals as well as antifungals targeted to emerging pathogens. This project seeks to develop the C.auris molecular genetic toolkit to enable manipulation of its genome, to generate a strain of C.auris lacking many of the multi-drug resistance pumps and with an increased in membrane fluidity. This will involve application of cutting edge molecular genetic techniques to manipulate the C.auris genome including the CRISPR-cas9 system, that enables standardized (multiplexed) construction of gene deletions, multi-pathway integrations and site-directed single-nucleotide mutagenesis. The effects on membrane fluidity will be assessed by fluorescence polarization and HRMAS NMR metabolomics. This drug-sensitized strain will be used to screen chemical libraries, to identify lead compounds that inhibit growth of Candida sp. The recently developed Galleria mellonella invertebrate model of systemic candidiasis will be employed to explore the impact of drugs that emerge from such screens.
C.auris and C.albicans are sensitive to derivatives of Dequalinium, a quaternary ammonium cation and bola-amphiphile commonly used as an antiseptic. The extensive repertoire of molecular-genetic resources developed in the baker’s yeast S. cerevisiae, will be used to probe the mode of action of such compounds. This will reveal facets of cell biology that are involved in bolalipid toxicity. Data will be validated by modulation of the relevant biological pathways, via gene deletion or over-expression as well as biochemical approaches involving assessing the activation states of any signal transduction pathways that respond to derivatives of Dequalinium. We will use the outcome of this approach to inform our attempts using medicinal chemistry to synthesize variants of the bolalipid with enhanced antifungal activity, testing them against C.albicans and C.auris.
Application Deadline Applications must be complete, including both references, by 11th January 2019 at 5pm
Fully funded place including home (UK) tuition fees and a tax-free stipend in the region of £16,777pa (plus £2000pa from the Industrial partner). Students from the EU are welcome to submit an application for funding, any offers will be subject to BBSRC approval and criteria.