A common mechanism by which Listeria, a type of bacteria, spreads from cell to cell during infection is reported online this week in Nature Cell Biology. The finding could prove useful in looking at ways to halt the development of diseases linked to Listeria, such as gastroenteritis.

Listeria monocytogenes is a highly virulent foodborne bacteria. It is responsible for listeriosis, which is linked to gastroenteritis in healthy individuals and more serious types of infections in pregnant women and those with weak immune systems.

During Listeria infection, bacteria replicate inside host cells, but it was unclear how the bacteria could then spread to infect other cells. Keith Ireton and colleagues show that certain molecules expressed by Listeria loosen the 'tension' of the membrane in infected host cells, allowing the bacteria to protrude and spread between cells more easily. This may be a common mechanism by which infectious agents promote cell-to-cell spreading during infection.