The discovery that salmonella bacteria are triggered into activity by changes in temperature is being hailed as a breakthrough against a feared killer.
Salmonella bacteria inside the human cell
Scientists at the Institute of Food Research in Norwich hope it will help in the development of a vaccine for farm animals carrying the bacterium.
Raw meat and eggs are often blamed for causing salmonella poisoning.
Researchers now believe that heat from human bodies triggers the bacteria to release lethal toxins.
Salmonella is one of only a handful of bacteria that can survive within a human cell.
Professor Jay Hinton, from the Institute of Food Research, is heading research.
He said: "When cold it does very little and does not express many genes. But when it gets inside the human body it is affected by temperature.
"It suddenly turns on the many genes needed to create infection.
"We estimate these can be as many as 530 and when these genes are turned on, the salmonella is able to cause disease."