Staphylococcus aureus is a bacterium that causes a variety of diseases ranging from local skin or soft tissue infections to invasive chronic infections such as pneumonia. Such infections are a major cause of death worldwide including New Zealand. They also disproportionately affect Māori and Pacific peoples.

Invasive chronic infections are often linked with the ability of S. aureus to form biofilms: complex mixtures of biomolecules made by microorganisms, which allow them to stick to surfaces (including human tissue), colonise them, and resist antibiotic treatment.

In this talk I will summarise our efforts to develop a diagnostic probe for S. aureus biofilm infected tissue by targeting serine hydrolases via a covalent link. Work on the serine hydrolase FphH is highlighted in the figure. An international collaborative team is combining structure-function characterisations with organic synthesis, peptide discoveries via phage display and in silico methods to achieve the required exceptional level of specificity.

In parallel, we are also investigating the contributions of these serine hydrolases to S. aureus biofilm formation and virulence, while trying to determine their biological functions. This is achieved via bacterial metabolomics investigations by linking microbiology with mass spectrometry and NMR techniques.

As a PhD graduate from the Chemistry and Biochemistry Departments at Otago, who is now exploring the world of Microbiology, one goal of this talk is to strengthen the scientific link between the three already physically linked Departments.