Salmonella research could lead to better antibiotics
Improved antibiotics to treat those contracting food poisoning from Salmonella could be developed following the results of new research carried out by scientists at the Institute of Food Research (IFR) in Norwich.
Scientists at IFR have discovered how the promiscuous Salmonella bacterium protects itself from “getting ill” after acquiring foreign DNA through “sex” with other bacteria. This discovery could lead to the design of new antibiotics to fight this killer disease.
Salmonella causes food poisoning and kills around 1M people worldwide every year. It is becoming more difficult to treat with drugs because it quickly evolves resistance to antibiotics by swapping genes with other bugs during “bacterial sex”. These foreign genes help the bacterium because they make it infectious and resistant to antibiotics.
In collaboration with Oxford Gene Technology, Professor Jay Hinton's group at the IFR has discovered that a protein called H-NS switches off these incoming genes until they need to be activated - a process called gene silencing.
The study, just published in the online journal PLoS Pathogens, shows that without proper control the incoming genes make proteins that are toxic for the bacterium. Without H-NS, the bacterium has problems growing and can't function properly. H-NS allows the bacteria to evolve by determining how new pieces of DNA are used in Salmonella.
“We may have found the Achilles' Heel for Salmonella bacteria because they need this H-NS protein to acquire new skills and become infectious,” says Hinton, “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 H-NS, we could discover urgently-needed new antibiotics.”
Salmonella Typhimurium can be found in a broad range of animals, birds and reptiles as well as the environment. It causes food poisoning in humans mainly through the consumption of raw or undercooked contaminated food of animal origin - especially poultry, eggs, meat, salad, vegetables and milk.
Dr Vittoria Danin, a member of Hinton's research team, believes the findings have implications for food supply in that they may eventually help to develop ways of inhibiting the development of Salmonella at source. However, nothing is likely in the short term, given restrictions on the use of antibiotics in the food chain.
