Lipopolysaccharide (LPS) covers the outer surface of Gram-negative bacteria. Lipid A is the part that anchors it and the part our immune system senses. We develop tandem mass spectrometry methods that work out lipid A structures from a single colony and map the rest of the molecule, including O-antigen. We also use lipid spectra as barcodes to identify bacteria and detect colistin resistance straight from clinical samples.
Our earlier methods include gas-phase fractionation, the first practical data-independent acquisition method and large-scale label-free quantitation. At UVic the focus is single cells and very small numbers of cells: glycated hemoglobin in one red blood cell, immune and cancer cells from patients, and bacteria taken straight from urinary tract infections.
Getting methods out of the lab and into use. Dave co-founded Pataigin in 2015 to bring lipid-based pathogen identification to hospital labs. He also directs the UVic–Genome BC Proteomics Centre, which has supported more than 20 B.C. life-sciences companies. Our one-hour urinary tract infection test is set to be adopted by Island Health.
Dave organizes the MSBM (Mass Spectrometry in Biotechnology and Medicine) Summer School, a five-day course in the fundamentals and applications of mass spectrometry, held in Dubrovnik since 2001. An international faculty teaches graduate students, postdocs and scientists from industry. The first three days cover the fundamentals, from sample preparation and separations to ionization, mass analyzers and data processing; the rest of the week applies them to proteomics, lipidomics, metabolomics, imaging and biologics.