A hi-tech medical dressing that changes colour when it detects infection has been developed by scientists.

The breakthrough - hailed as a lifesaver - will improve treatments for burns patients and help combat the global problem of antibiotic resistance, according to the developers.

Children with burn wounds are particularly susceptible to bacterial infections because of their immature immune systems.

Such infections can slow wound healing, leading to longer hospital stays as well as increased risk of permanent scarring. In severe cases, burn infection can lead to sepsis, which can kill.

The scientists said it was extremely difficult for doctors to diagnose infections quickly and at the patient's bedside.

Existing methods take up to 48 hours and require removing the wound dressing which is painful and distressing for the patient and may result in slower healing and potentially life-long scarring.

Due to this time delay, when a child with a burn shows symptoms of a possible infection, the clinician often has to treat them with antibiotics as a precaution before their infection is confirmed.

However, treatment with antibiotics when there is no infection can lead to bacteria becoming resistant to antibiotics.

Antibiotic resistance has been identified by world leaders as one of the biggest health threats we face today.

The prototype dressing, which changes colour as soon as the wound is infected, has been developed by scientists at the University of Bath.

They have collaborated with the Healing Foundation Children's Burns Research Centre, based at the Bristol Children's Hospital, and the University of Brighton to develop the dressing.

This will enable doctors to quickly treat only those patients with an infection, without giving unnecessary antibiotics to patients who may simply have symptoms due to a cold.

Project leader Dr Toby Jenkins, reader in biophysical chemistry at Bath, said: "Our medical dressing works by releasing fluorescent dye from nanocapsules triggered by the toxins secreted by disease-causing bacteria within the wound.

"The nanocapsules mimic skin cells in that they only break open when toxic bacteria are present; they aren't affected by the harmless bacteria that normally live on healthy skin.

"Using this dressing will allow clinicians to quickly identify infections without removing it, meaning that patients can be diagnosed and treated faster. It could really help to save lives."

The team has been awarded almost £1 million by the Medical Research Council to test the dressing with real samples taken from the wounds of burns victims.

Dr Amber Young, who will lead the testing of the prototype at Bristol Children's Hospital, said: "Children are at particular risk of serious infection from even a small burn.

"However, with current methods clinicians can't tell whether a sick child might have a raised temperature due to a serious bacterial burn wound infection, or just from a simple cough or cold.

"Being able to detect infection quickly and accurately with this wound dressing will make a real difference to the lives of thousands of young children by allowing doctors to provide the right care at the right time, and also, importantly, reduce the global threat of antibiotic resistance."

Once the dressing has been fully tested the team plans to develop it for use in hospitals in around four years.