🔬📜 “The recording of ancient DNA of pathogens has completely changed our understanding of infectious disease in the past, and here we show that parchment can also preserve animal pathogen DNA." - Louis L’Hôte, the study’s lead author and a PhD student at UCD School of Agriculture and Food Science

I am opening a PhD position at the University of Vienna to work with me on ancient pathogen aDNA 🦠🧬 Please help spread the word to any relevant candidates or contact me if you are interested! Join us here in Vienna!

New preprint for the Ruminant Paleogenomic group! PISGTI (Pathogen anImal Genome Sequence ToolkIt), a pipeline for host detection + ancient pathogen authentication. By using PISGTI on published domesticated animal datasets, we notably found ancient Rickettsia felis and Leptospira borgpetersenii.

8/ Finally, our oldest genome makes SPPV the oldest poxvirus genome ever recovered yet. It's helping us understand how this deadly virus evolved, and it shows that parchment archives are an untapped record of ancient disease, just waiting to be read.

7/ Finally, we modeled the evolution of the wider capripoxvirus genus. It is most likely that SPPV and goatpox independently inactivated the exact same 8 genes in two separate events of convergent evolution. This genus likely expanded with domestication, as herding let viruses jump between species

6/ Genomic analysis shows the virus has been remarkably stable over the last 3,500 years. Using the ancient genomes to calibrate a molecular clock, we estimate that SPPV emerged around 5,000 years ago.

5/ More surprisingly, we found SPPV in goat and calf parchment too, modern sheeppox is mostly find in sheep (goat sometime). Possible explanations: a real host jump not seen in circulating viruses today, or contamination during parchment-making, sheep-derived products like glue used on parchemnt.

4/ Finding viral DNA in parchment is fascinating, but when you think about it, it's not that surprising: parchment is made from animal skin. It preserves the animal's own DNA, so why wouldn't it also preserve the pathogens that were living in that skin?

3/ We screened a lot of different samples for sheeppox virus, and found 21 genomes, the earliest ones around 3,500 years old, from Bronze Age Eurasian sheep, plus genomes from early 20th-century veterinary collections... and 18 from medieval parchment 📖

2/Sheeppox was first described by Columella in Roman times, and we also have a lot of written sources describing it throughout medieval Europe and later. But how far back does it really go, and how has it evolved since?