Yersinia pestis, the subject of [Barbara Bramanti’s] research, is the bacterium responsible for three bubonic plague pandemics over human history.
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The origin of the second Medieval epidemic and the routes by which it was transmitted are as yet unclear.
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[Bramanti] and her group sequenced five new plague genomes from 14th century skeletons in Italy, France, Holland, and Norway. They also reanalyzed previously isolated plague samples so they could confidently compare the samples.…
The bacteria they found in France and Norway was the same as that previously identified in London and Barcelona as responsible for the Black Death there (with the caveat that they didn’t sequence the entire genome; all of the DNA that was analyzed was identical). The Italian variant, taken from a mass grave, had sequences that dated it as a more recent strain than the others. Bramanti thinks that this strain came from overseas through the port of Pisa and acquired its new sequences as it scythed through Tuscany in 1348.
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These genetic analyses, along with climatic studies done by Bramanti’s colleague Nils Stenseth, all argue that Yersinia pestis entered Western Europe from Asia repeatedly during the second plague pandemic rather than hanging out in Western European rodents the whole time.
Read full, original post: Medieval European plague genomes hint at Black Death’s travels
