The molecular arms race between bacteria and their phages: biology and exploitation

Bacteria have evolved ‘immune systems’ as a result of their constant exposure to foreign mobile genetic elements, including bacteriophages and plasmids. For example, an estimated 1,025 bacteriophage infections occur every second. Other mobile genetic elements can harbour antibiotic resistance or pathogenicity determinants, which influence bacterial evolution and our ability to treat infectious diseases.

To thwart these invaders, bacteria have many resistance strategies, including innate immunity, such as restriction-modification and abortive infection systems, and adaptive immunity provided by the CRISPR-Cas systems.

Recently, there have been major advances in our understanding of these systems and the different strategies that phages have evolved to evade these immune mechanisms. In this talk I will present our recent research into bacterial defence systems and phage counter-defences.