Month: September 2022

AT LEAST THREE BLACK DEATHS. “Yersinia pestis has caused at least three human plague pandemics. The second (Black Death, 14–17th centuries) and third (19–20th centuries) have been genetically characterised, but there is only a limited understanding of the first pandemic, the Plague of Justinian (6–8th centuries).” https://lnkd.in/gY5rX65 View in LinkedIn

GENETIC LINEAGE. “Yersinia pestis evolved from the closely related zoonotic enterobacterium Y. pseudotuberculosis to become one of the most virulent pathogens known to humans. Its recent identification in ancient human material from Altai, Siberia suggests it caused human infections as early as 5,000 years ago, though its ability for flea-borne transmission leading to bubonic disease might have been absent in these older, divergent lineages.” https://lnkd.in/g9Pgxuv View in LinkedIn

HISTORICAL RECORD. “To our knowledge, bubonic plague, and presumably also the pneumonic and septicemic forms, have been the likely culprit of three major pandemics, namely the Plague of Justinian (Eastern Roman Empire, 6th and 8th centuries AD), the second-wave plague pandemic (Europe, mid-14th century Black Death until the mid-18th century AD), and the third plague pandemic that started during the late 19th century in China. In recent years, however, ancient DNA (aDNA) has confirmed a Y. pestis involvement in both historical pandemics.” https://lnkd.in/g9Pgxuv View in LinkedIn

FROM EUROPE TO CHINA. “Ancient Y. pestis genomes obtained from medieval victims have indicated the presence of a radiation event immediately preceding the Black Death that gave rise to most of the strain diversity circulating in the world today. Based on the relationship of ancient European and modern genomes, it was recently suggested that a wave of plague might have traveled from Europe toward Asia after the Black Death, eventually settling in China and later giving rise to the third pandemic.” https://lnkd.in/g9Pgxuv View in LinkedIn

PLAGUE PERSISTENCE. “After the Black Death, plague continued to strike Europe for another four centuries through subsequent outbreaks that ceased at the end of the 18th century. The reasons for its sudden disappearance in Europe are unknown. Sylvatic plague foci have a nearly worldwide presence today, but are absent in Europe.” https://lnkd.in/g9Pgxuv View in LinkedIn

SOURCE. “Here, we aim to address three outstanding questions regarding Y. pestis history. First, we investigate the possibility of disease entry via multiple pulses during the Black Death by comparing the genotype of a strain from the pandemic’s early phase to those circulating in other areas later in the pandemic.” https://lnkd.in/g9Pgxuv View in LinkedIn

SPREAD. “Second, we evaluate the likelihood of the proposed eastward migration of strains from Europe to Asia after the Black Death through the analysis of human remains from a 14th century plague burial in the Volga region of Russia.” https://lnkd.in/g9Pgxuv View in LinkedIn

PERSISTENCE. “Third, we take a further step toward understanding the relationship of post-Black Death outbreaks in Europe and evaluate the likelihood of a local reservoir.’ https://lnkd.in/g9Pgxuv View in LinkedIn

GENOME SEQUENCING. “Following the success of previous genomic investigations of ancient bacterial disease, we employ similar methods of DNA capture and high-throughput sequencing to retrieve the genomes of three historical Y. pestis strains.” https://lnkd.in/g9Pgxuv View in LinkedIn

SAME LINEAGE CONFIRMED. “Our genomes from Barcelona, Bolgar City, and Ellwangen group on the same phylogenetic branch (Branch 1), adding further legitimacy to the notion that the Black Death and subsequent plague outbreaks in Europe, as well as the worldwide third pandemic, were caused by the same Y. pestis lineage.” https://lnkd.in/g9Pgxuv View in LinkedIn