Yersinia pestis: Looking back 4000 years

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For how long has humanity lived with plague? Researchers at the Francis Crick Institute have identified three 4,000-year-old British cases of Yersinia pestis, the bacterium causing the plague. This is the oldest evidence of the plague in Britain to date.

 

The scientists identified two cases of Y. pestis in human remains found in a mass burial in Charterhouse Warren in Somerset and one in a ring cairn monument in Levens in Cumbria.

 

Taking small skeletal samples from 34 individuals across the two sites, the researchers screened them for the presence of Y. pestis in samples of teeth. This required the researchers to drill into the tooth and extract dental pulp, which can trap DNA remnants of infectious diseases.

 

 

The scientists next analysed the DNA and identified three cases of Y. pestis in two children estimated to be aged between 10-12 years old when they died, and one woman aged between 35-45. Radiocarbon dating was used to show that the three people lived at roughly the same time.

 

The plague has previously been identified in several individuals from Eurasia between 5,000 and 2,500 years ago, a period spanning the Late Neolithic and Bronze Age. However, the disease had not been seen before in Britain at this point in time.

 

This strain of the plague -- the LNBA lineage -- was likely brought into Central and Western Europe around 4,800 years ago by humans expanding into Eurasia (and now it seems, Britain). By using genome sequencing, the researchers showed that this strain of the Yersinia looks very similar to the strain identified in Eurasia at the same time. In particular the organisms identified each lacked the yapC and ymt genes, which are seen in later strains of plague, the latter of which is known to play an important role in plague transmission via fleas.

 

This information has previously suggested that this strain of the plague was not transmitted via fleas, unlike later plague strains such as the one that caused the Black Death.

 

These genomes can inform scientists about the spread and evolutionary changes of pathogens in the past to hopefully help them to understand which genes may be important in the spread of infectious diseases today.

 

See:

 

Pooja Swali, Rick Schulting, Alexandre Gilardet, et al. Yersinia pestis genomes reveal plague in Britain 4000 years ago. Nature Communications, 2023; 14 (1) DOI: 10.1038/s41467-023-38393-w

 

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)