Reconstructing the 6th century plague from a victim

August 30, 2016

Before the infamous Black Death, the first great plague epidemic was the Justinian plague, which, over the course of two centuries, wiped out up to an estimated 50 million (15 percent) of the world's population throughout the Byzantine Empire----and may have helped speed the decline of the eastern Roman Empire.

No one knows why it disappeared.

Recent molecular clues from ancient plague victims have suggested that plague may have been caused by the same bacterium, Yersinia pestis, which was responsible for the Black Death. But the geographic reach, mortality and impact of the Justinian pandemic are not fully known.

Both information from ancient hosts and bacteria could shed light on the role of plague, which has afflicted mankind for more than 5,000 years.

Now, scientists based in Germany, including Michal Feldman, Johannes Krause, Michaela Harbeck and colleagues have confirmed this by recovering the bacterial culprit from sixth century skeletons found in Altenerding, an ancient southern German burial site near Munich. The Altenerding genome dates back to the beginning of the plague.

They have generated the first high-coverage genome of the bacterial agent responsible for the Justinian plague. In addition to revealing new insights in the molecular evolution of Yersinia pestis since the Byzantine times, the new sequence shows features that could not detected due to the limitations in the coverage of a draft genome previously reported by Wagner*, including 30 newly identified mutations and structural rearrangements unique to the Justinianic strain., as well as correcting 19 false positive mutations.

"The fact that the archeological skeletons which gave these exciting insights were excavated over 50 years ago underscores the importance of maintaining well curated anthropological collections," said author Michaela Harbeck. "We were very fortunate to find another plague victim with very good DNA preservation in a graveyard just a few kilometers from where the individual analyzed in Wagner et al. was found. It provided us with the great opportunity to reconstruct the first high quality genome in addition to the previously published draft genome."

Three are located in genes critical to plague virulence: nrdE, fadJ and pcp genes. Their data also suggested that the strain was more genetically diverse than previously thought. How and why the pathogen reached Germany remains a mystery.

This new findings allow the authors to develop guidelines that could help improve the quality and authenticity of genomic data recovered from candidate ancient pathogens. And with plague classified as a re-emerging infectious disease in certain regions, an important historic, high-quality reference resource has been generated to offer insights into key the evolutionary changes, adaptation and human impact of plague.

"Our research confirms that the Justinianic plague reached far beyond the historically documented affected region and provides new insights into the evolutionary history of Yersinia pestis, illustrating the potential of ancient genomic reconstructions to broaden our understanding of pathogen evolution and of historical events," said research colleague Michal Feldman. "Our reanalysis of previous datasets stresses the importance of following strict criteria to avoid errors in the reconstruction of ancient pathogen genomes."
-end-


Molecular Biology and Evolution (Oxford University Press)

Related Plague Articles from Brightsurf:

Grape pips reveal collapse of ancient economy in the grip of plague and climate change
A team of archaeologists from Bar-Ilan University and the University of Haifa has discovered new and compelling evidence for a significant economic downturn on the fringe of the Byzantine Empire in the aftermath of a major pandemic in the mid-6th century CE.

Ancient disease may increase resilience to bubonic plague
Researchers have discovered that Mediterranean populations may be more susceptible to an autoinflammatory disease called familial Mediterranean fever because of evolutionary pressure to survive the bubonic plague epidemics.

Infectious disease modeling study casts doubt on impact of Justinianic plague
Many historians have claimed the Justinianic Plague (c. 541-750 CE) killed half of the population of Byzantine (Eastern Roman) Empire.

Justinianic plague not a landmark pandemic?
A study of diverse datasets, including pollen, coinage, and funeral practices, reveals that the effects of the late antique plague pandemic commonly known as the Justinianic Plague may have been overestimated.

Ancient genomes provide insight into the genetic history of the second plague pandemic
An international team of researchers has analyzed remains from ten archaeological sites in England, France, Germany, Russia, and Switzerland to gain insight into the different stages of the second plague pandemic and the genetic diversity of Yersinia pestis during and after the Black Death.

How plague pathogens trick the immune system
Yersinia have spread fear and terror, especially in the past, but today they have still not been completely eradicated.

Details of first historically recorded plague pandemic revealed by ancient genomes
An international team of researchers has analyzed human remains from 21 archaeological sites to learn more about the impact and evolution of the plague-causing bacterium Yersinia pestis during the first plague pandemic (541-750 AD).

2017 pneumonic plague outbreak in Madagascar characterized by scientists
Plague is an endemic disease in Madagascar. Each year there is a seasonal upsurge between September and April, especially in the Central Highlands, which stand at an elevation of more than 800m.

An ancient strain of plague may have led to the decline of Neolithic Europeans
A team of researchers from France, Sweden, and Denmark have identified a new strain of Yersinia pestis, the bacteria that causes plague, in DNA extracted from 5,000-year-old human remains.

Researchers engineer dual vaccine against anthrax and plague
A team of researchers has now engineered a virus nanoparticle vaccine against Bacillus anthracis and Yersinia pestis, tier 1 agents that pose serious threats to national security of the United States.

Read More: Plague News and Plague Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.