Canadian and German researchers say they have sequenced the entire genome of the Black Death, not only pinpointing its cause but also clearing the way for a better understanding of modern pandemics.

The international team led by researchers at McMaster University and the University of Tubingen in Germany said the find, which is published online in the scientific journal Nature, marks the first time that scientists have been able to draft a reconstructed genome of any ancient pathogen.

And they said this will allow researchers to track changes in the pathogen's evolution and virulence over time.

"This is a massive technological advancement and is really opening the doors to a whole new field of research," Kirsten Bos, a researcher at McMaster University told CTVNews.ca.

"Previous to our publication we were only able to identify small, short pieces of bacterial or of viral DNA in ancient remains and with our research methods we know it is now possible to actually obtain far more genetic information up to full genomes as we have done for the Black Death."

Bos said with this advancement they can now look at pathogens in the past and monitor their changes over time, something researchers have not been able to do.

Using skeletal remains from victims buried in the East Smithfield "plague pits" in London, the researchers extracted the Yersinia pestis bacterium, which they say was responsible for the plague that killed 50 million Europeans between 1347 and 1351.

By linking the 1349-1350 dates of the skeletal remains to the genomic data the researchers determined that the age of the bug that spawned the medieval plague formed sometime between the 12th and 13th centuries.

"We found the genome of arguably the most notorius pathogen of all time," said Bos. "We can now look at the differences between the ancient organisms and compare that against the modern organisms to see how they have changed over time to determine whether the organisms from the 14th century possessed some sort of genetic mutation that just made it such a ferocious killer."

Even today a strain of the deadly disease exists, killing some 2,000 people each year.