Each year, dysentery – an infection of the intestines – is responsible for hundreds of thousands of deaths among children under the age of 5 years in developing countries. Now, researchers reveal they are a step closer to combatting the disease, with the help of bacteria recovered from a World War I soldier who died from the infection.

Dr. Alison Mather and colleagues conducting their researchShare on Pinterest
Researchers decoded the DNA of a Shigella flexneri bacteria sample to learn more about how it evolves. The sample came from a soldier who fought during World War I.
Image credit: Sanger Institute

There are two types of dysentery. The first is bacillary dysentery (shigellosis), caused by Shigella flexneri bacteria. This is the most common form of the disease. The second type is amoebic dysentery (amoebiasis), caused by the Entamoeba histolytica amoeba – a single-celled parasite.

Infection with either of these bacteria can cause intestinal inflammation, leading to stomach cramps, nausea, vomiting and bloody diarrhea.

Dysentery is passed on through poor hygiene and contaminated food and water, meaning people who live in developing countries are most at risk. In these countries, poor access to medical care makes the disease life-threatening. As such, developing a vaccine for the infection is crucial.

Now, in a new study published in a special World War I edition of The Lancet, researchers from the UK detail how they have – for the first time – genetically decoded DNA from a Shigella flexneri sample from 1915. This has enabled them to learn more about how the bacteria have evolved over the past century.

Senior study author Prof. Nick Thomson – of the London School of Hygiene and Tropical Medicine and the Wellcome Trust Sanger Institute, both in the UK – and colleagues say the information they have gained brings them closer to tackling the disease.

Using records from Public Health England and the National Archives, co-first author Dr. Alison Mather, of the Sanger Institute, discovered that the Shigella flexneri sample was collected in a military hospital of a French coastal town, Wimereux, during World War I.

The sample was labeled with what the researchers believed was a surname, alongside the name of the bacteriologist who collected the sample. Using this information, they tracked down who it belonged to.

They found the sample was from Private Ernest Cable, a soldier who fought on the front lines during World War I. He was part of the Second Battalion of the East Surrey Regiment, and he died from dysentery on March 13th, 1915.

“So many of the samples we work with in bacterial genomics have stories that we’ll never know,” says Dr. Mather. “Finding Ernest and learning his story was a chance to commemorate those who fought in World War I, and to highlight the burden of infectious disease during this time.”

Dr. Mather and colleagues used genome sequencing to decode the DNA of the sample.

From this, they discovered that Shigella flexneri was resistant to penicillin 25 years prior to the antibiotic being commonly used to treat bacterial infections. The bacterium has evolved to resist antibiotics ever since.

“While only 2% of the genome from this first sample differs from modern isolates, the changes that Shigella flexneri has acquired enable it to evade the antimicrobial treatments we use to fight it,” explains co-first author Dr. Kate Baker, of the Sanger Institute.

Commenting on the team’s findings, Prof. Thomson says:

There are two parts to this story. [Firstly], modern genomics has given us the power to untangle fine-scaled relationships between organisms and tell us how they have changed over time.

[Secondly], linking this to a soldier who contracted the infection at the very beginning of World War I allowed us to focus on a very real human story that helps us navigate through what was such a monumental and complex period in our history.”

Sadly, Private Cable was found to have no surviving family members. But Dr. Mather was able to track down a retired Royal Air Force serviceman, Michael Norman, whose grandparents had Private Cable as a lodger before he joined the army.

Norman’s father was the beneficiary of Private Cable’s will and received his memorial plaque after he died. The plaque is on display in Norman’s home, engraved with the words: “He died for freedom and honor.”

Prof. Thomson notes that “the historical perspectives we gain from samples like [Private Cable’s] are important because they provide the background information we need to understand infections today.”

Earlier this year, Medical News Today reported on the discovery of a 6,200-year-old schistosomiasis parasite egg in a grave in Syria. Schistosomiasis – a disease caused by parasitic trematode flatworms that reside in certain types of freshwater snails – can cause anemia, kidney failure and bladder cancer.