Teeth and bones sampled from 76 skeletons found in “plague pits” in France, Germany, Italy and the Netherlands and sequenced for DNA intrusion are conclusive evidence that Y. pestis was to blame, they said.
Y. pestis has been in the dock for more than a century as the source of so-called Black Death, which gripped Europe in successive outbreaks from the 14th to the 18th century.
But scientific data to convict the bacterium have until now been sketchy or debatable.
As a result, a clutch of rival theories have blossomed, including the contention that an Ebola-style virus or the anthrax germ were to blame.
The study, published in the open-access journal PLoS Pathogens, also sheds unexpected light on the geographical route taken by the germ, which is believed to have originated in central or southern Asia before arriving in Europe through trade.