The discovery of how bacteria build self-protection systems is being heralded as a breakthrough in the search for a cure for salmonella.
Scientists seeking a cure for salmonella claim a breakthrough
Institute of Food Research scientists in Norwich believe they now know how bacteria become resistant to drugs.
This could lead to new antibiotics to fight the disease, the team claims.
Professor Jay Hinton said salmonella evolves resistance by swapping genes with other bugs during "bacterial sex" and these are activated when needed.
These foreign genes help to keep salmonella infectious and resistant to antibiotics.
The self-protection depends on a protein called H-NS which keeps the incoming genes dormant until they are needed for self defence, the scientists said.
By making this protein permanently inactive the salmonella remains open to attack by antibiotics.
Professor Hinton said: "We may have found the Achilles Heel for salmonella bacteria because they need protein to acquire new skills and become infectious.
"Salmonella still kills a huge number of people. Discoveries like this will help us find new ways of attacking these dangerous bacteria.
"If we can inactivate the protein we could discover urgently-needed new antibiotics."