Most people who catch a dose of the food poisoning bacteria Salmonella just suffer a nasty bout of diarrhoea. But if the bacteria spread through the body, which can occasionally happen in young children and the elderly, this 'tummy bug' can be life-threatening. Treatment with antibiotics often works, but sometimes the infection comes back with a vengeance when the drugs stop. To discover why, researchers are studying mice that suffer from Salmonella infections in the same way we do. They've found that the bacteria 'hide out' in special immune cells called dendritic cells – highlighted green in this image of an infected mouse's lymph node – and slow down their growth. This enables them to lay low and resist antibiotic treatment, so they can grow again afterwards. Stimulating the immune system helps to flush out these sneaky bugs, which could be a new approach for treating severe infections in future.
Written by Kat Arney
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