Scientists who unlocked the genetic code of bacteria grown from a soldier who died of dysentery in World War I say it revealed a superbug already resistant to penicillin and other antibiotics decades before they were in common use.
The discovery sheds light on the history of antibiotic resistance — now a global health threat — and offers fresh clues on how to tackle dysentery, a disease that kills hundreds of thousands of children every year in developing countries.
"Even before the description and widespread use of penicillin, this bacterium was resistant to it," said Kate Baker of Britain's Wellcome Trust Sanger Institute, who worked on the research with colleagues at Public Health England.
Dysentery is a life-threatening disease that is becoming increasingly hard to treat due to its growing ability to evade antibiotic treatment. It was rife in the trenches during World War I, and still spreads in unsanitary conditions in poor countries and in conflict zones.
The genetic data from this sample of bacteria — known as Shigella flexneri — which infected a soldier on the Western Front, show how the pathogen has changed in the past century.
Baker's research is to be published in The Lancet medical journal on Saturday.
She said in a telephone interview that analysis of genetic differences between this 1915 sample of Shigella flexneri and three others isolated in 1954, 1984 and 2002 showed that while the bacterium has changed relatively little, the mutations it has acquired have made it more dangerous and persistent.