Plague genomes of the last pandemic were linked to 14th century Black Death by researchers at the Max Planck Institute for Science of Human History (Jena, Germany).
The plague is a poorly understood phenomenon despite its ravaging resurgences across Europe since the mid-fourteenth century. The deadliest pandemic, known as the Black Death ravaged Europe’s population. It is estimated that 30 to 50 percent of England’s population died in only five years.
For the following four centuries, the plague, caused by the Yersinia pestis bacteria, broke out over and over again. It is widely agreed that the last European plague pandemic was the Great Plague of Marseille. Lasting for approximately two years, between 1720 and 1722, the Marseille pandemic once more took a high toll on the population. After that, everything went quiet. The plague never surged again on the European continent.
With so little known about the plague and Yersinia pestis, scientists are wondering what caused it? Where did the Yersinia pestis hide in the short periods between the plague pandemics? Where, if at all, is it hiding now and could such a devastating plague hit Europe once more?
A joint research team led by scientists of the Max Planck Institute for Science of Human History tried to find at least some clues that could lead to answers. The first step was to obtain access to teeth of those who were killed in the Great Plague of Marseille. With several well-preserved teeth, the team was able to reconstruct the pathogen genomes of the victims. These DNA fragments have been preserved for hundreds of years.
Despite their good condition, the scientists had a difficult time in reconstructing the pathogen genomes. Mainly due to the fact that they are entirely distinct from modern and studied forms of the plague. According to the findings reported in the eLifeSciences journal, the identified genomes speak of an extinct form of the plague.
Overall, the research team could reconstruct five Yersinia pestis genomes. The lineage has no common traits with any other forms studied to date. However the plague genomes of the last pandemic were linked to 14th century Black Death. Thus, the same form of the plague could have persisted for over three centuries and then gone extinct as no similarities with modern forms have surfaced.
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