The search for the bacteria Yersinia pestis, which causes plague, in a selection of skeletons from the dig continued last year in the osteology department at Mola where all the Liverpool Street finds were stored and examined by Michael Henderson. Professor Vanessa Harding, an expert in London history at Birkbeck, University of London, said: 'This is a very exciting finding, for the history of London, the history of disease, and the history of burial. DNA sequenced from ancient skeletons dating back to the 17th century was found to match that of the bacteria responsible for the plague, known as Yersinia pestis. (CNN) In 1665, the Great Plague of London killed more than 75,000 people in the space of a year, almost a quarter of the city's population back then. Evidence of the pathogen had eluded archaeologists but seemed tantalisingly close when a suspected mass grave was discovered last year during a Crossrail dig at the Bedlam burial ground, also known as the New Churchyard, in East London. Any Yersinia bacteria on the surface of the skeletons would have died long ago, meaning scientists had to extract DNA from teeth, where enamel helps protect and preserve DNA with less risk of contamination. "We don't know why the Great Plague of London was the last major outbreak of plague in the UK and whether there were genetic differences in the past, those strains that were circulating in Europe to those circulating today; these are all things we're trying to address by assembling more genetic information from ancient organisms." Scientists from the Max Planck Institute in Jena, Germany, analyzed DNA extracted from 20 skeletons found in the mass burial pit, as well as 20 skeletons from other parts of the burial ground to compare. The mass grave is one of around 3,300 burials that have been uncovered during excavations at the New Churchyard.
German scientists confirm that the cause of the Great Plague of London from 1665–1666 was Yersinia pestis (cause of the Bubonic plague).