A First World War soldier is helping scientists understand the development of antibiotic resistance, 100 years after he perished on the Western Front.

Private Ernest Cable, 28, from the 2nd Battalion East Surrey Regiment, died from dysentery on March 13, 1915.

A sample of the bug that killed him, a strain of the dysentery bacteria Shigella flexneri called NCTC1, was stored for future research.

Scientists at Public Health England's National Collection of Type Cultures, which holds thousands of bacterial samples at sites near London and Porton Down, Wiltshire, have now unlocked the secrets of its genetic code.

They discovered the strain had genes for resistance to penicillin, 25 years before the antibiotic was commonly used to treat infections. It was also resistant to erythromycin, another antibiotic used in medicine today.

The research, published in The Lancet medical journal, confirms that some genes for antibiotic resistance existed long before widespread use of the drugs.

Other genes for virulence and resistance that were missing from Private Cable's dysentery bug were present in three other strains of the bacteria collected in 1954, 1984 and 2002.

Julie Russell, head of culture collections at Public Health England, said: "It is tragic that Private Cable died of dysentery alongside many other soldiers during the First World War due to the terrible conditions in the trenches

"Unfortunately, even 100 years later this bacteria is the cause of death of hundreds of thousands of people in developing nations each year. The root cause is poor sanitation.

"Techniques like genome sequencing can help us to better understand which medicines will and won't work by looking at bacterial genes, and may even help us develop a vaccine.

"Genome sequencing has revolutionised our understanding of bacteria and viruses and is already being used to help understand outbreaks of infectious disease."