Antimicrobial resistance (AMR) is a leading cause of mortality worldwide and is anticipated to become a far greater public health crisis over the next decade. AMR is spread between bacterial pathogens by a range of horizontal gene transfer mechanisms including transformation, conjugation, transduction, and gene transfer agents (GTAs). Of these four routes, GTAs are the most poorly understood.
GTAs are virus-like particles found inside bacterial genomes that can transfer host bacterial DNA between bacterial cells. When GTAs are activated, the host bacterial genome is chopped up into fragments which are packaged into newly assembled GTA particles. GTAs then lyse the host cell to escape and transfer the packaged DNA into recipient bacteria. GTAs are distinct from bacterial viruses (bacteriophages) in that they randomly package host DNA but not their own and therefore cannot self-replicate and are not ‘infectious particles’. Moreover, it appears that during evolution, GTAs may have been co-opted by bacterial cells as conduits for gene transfer.
The overall aim of Emma’s research is to build a complete understanding of the fundamental biology of GTA particles and thereby improve our understanding of how GTA-mediated gene transfer contributes to AMR. This may ultimately inform the development of GTAs as genetic tools and therapeutics in industry and medicine, respectively.