The oldest strain of the Yersinia Pestis strain was found in the remains of the gathering hunter, who lived five thousand years ago. As the genetic analysis showed, the ancestor of the pathogen of the plague, which caused a pandemic of black death in the Middle Ages, was at first there was no less contagious and not so deadly. This is reported in an article published in the Cell Reports magazine.
The remains marked as RV 2039 belonged to a man 20-30 years. They were discovered at the end of the 19th century in the Inchukaln region in Latvia, but then they were temporarily lost until 2011, when they were discovered in the Rudolph Virchow Rudolph Virchow. There were also the remains of three more people who belonged to the same group of hunter collectors were also found at the burial site.
Researchers analyzed samples of tissues of teeth and bones of skulls of all four to sequenate their genomes, and then tested for the presence of bacterial and viral pathogens. They revealed the genetic material y.pestis inside the bones of the RV 2039 and then reconstructed the genome of the bacteria and compared it with the genomes of other ancient strains. It turned out that a plaque wand is part of the line that occurred seven thousand years ago, in just a few hundred years, when Y.Pestis went to his ancestor Yersinia pseudotuberculosis.
Early strain is characterized by the lack of several genes characteristic of the option that caused a medieval pandemic that has killed half the population of Europe. For example, it does not have a gene, which contributes to the transfer of microorganism from fleas to a person and the formation of beubons in patients with people with a bubonic form of the disease. This type of transfer through flea also requires the death of a host person, after which insects begin to move on other people, spreading the pathogen. For the occurrence of this adaptation, it took more than a thousand years.
It is unknown which symptoms of the disease experienced RV 2039. The bacteria settled in its bloodstream, and most likely he died of a bacterial infection. High infectious load of blood vessels is associated with a less aggressive form of the disease. People who were buried next to infected, did not have signs of infection, therefore, it is unlikely that the plague was unlikely to be transmitted by air-droplet. Most likely, the infection occurred through the bite of Rodent and did not spread to the people around him.
The opening contradicts the statements of some historians, according to which the pathogens of the plague evolved in the cities near the Black Sea, in which more than 10 thousand people lived. However, five thousand years ago, large settlements have not yet existed, and agriculture in Central Europe just started to develop. It also allows us to reject the hypotheses that the plague caused a significant reduction in the population in Western Europe at the end of the Novocamean Century.