Watch an infection take hold inside the body
2 July 2012 Last updated at 00:40 BST
What does an infection look like as it takes hold in the body?
For the first time, scientists at the MRC Centre for Molecular Bacteriology and Infection at Imperial College London have used scanning equipment to watch an infection unfurl, in real time, inside an animal.
In this video, a series of scans show how a bacterial infection moves around a mouse's body, as the BBC's James Gallagher explains.