"The Black Death was caused by the bacterium Yersinia pestis — the one responsible for current plague outbreaks. This settles the controversy surrounding the causative agent. Although we cannot rule out, at this stage, that there was another co-circulating strain," said study author Hendrik Poinar, a biological anthropologist at McMaster University in Ontario.
….
But differences between plagues has led some to speculate that the Black Death was the result of an agent other than Y. pestis bacteria, with some even saying it more closely resembled infections of the Ebola virus, based on historical descriptions.
The researchers found that people who died during the Black Death had genes of Y. pestis, while the bodies of people who had died earlier nearby lacked these genes.
….
Poinar said he hopes future research in the area will shed light on how the modern incarnations of the bacteria spread and infect people. Some DNA segments in the ancient and modern strains "were identical to some circulating strains today, meaning that we cannot, from this stretch of DNA alone, make any claims as to difference in epidemiology between current and ancient strains."
"This technology will allow for the entire genome to eventually be sequenced down the road, and that may shed light on the differences between past and present epidemics," Poinar said.
