Silver seems to help prevent harmful bacteria from spreading by disrupting how they move around.

The precious metal has long been used to stop the transmission of bacteria – for example, in the filters of some medical face masks and in the antibacterial coatings used on the International Space Station . But until now, one reason it has a sanitising effect had gone unnoticed.

To find out, researchers at the University of Arkansas exposed E. coli to small doses of positively charged silver …