Scientists Extract Justinian Plague DNA From An Old Tooth

By Joelle Renstrom | Published

toothHaving been felled this week by the indescribably nasty Norovirus, I’m grateful for two things: first, that I wasn’t on a cruise ship, and second, that it wasn’t the plague (even though it felt like it at times). When I returned to the internets, a story about scientists bringing back an ancient plague from an old tooth caught my eye.

About 1,500 years ago, something even more gnarly than Norovirus ripped through the Roman Empire — nope, not the Pope, but the Justinian Plague, which struck the region in 541 AD, wiping out about 25% of Emperor Justinian’s constituency. Apparently the Emperor himself got sick, but he managed to get better, probably because his health insurance plan was better than everyone else’s. Historians think that the Justinian plaque was a major contributing factor to the fall of the Roman Empire, as estimates suggest that it might have killed up to 50 million people in Europe, Africa, and Asia. Good times!

ancient tooth

Based on grisly accounts of the devastation, scientists theorized that the same bacteria that caused the Justinian plague caused the more famous bubonic plague that decimated Europe back in the 1300s. While many people associate the spread of that disease with rats, it’s actually the fleas that were the carriers. A bite from an infected flea would cause microbes to head to the lymph nodes and start multiplying, swelling the nodes into lovely masses called buboes. But without more evidence, scientists couldn’t definitively link the two plagues — until now.

Housing developers outside of Munich recently dug up a burial site — don’t they know you’re not supposed to do that?! Get ready for the curse, folks! — dating back to the time of Emperor Justinian. The mass graves suggested death by disease, so they examined the skeletal remains, focusing on the teeth, which still contained blood, which still contained evidence of plague-causing bacteria.

The scientists set about decoding the bacteria, publishing their findings in Lancet Infectious Diseases. Their research reveals that the Justinian plague was caused by bacteria that spread from rodents, but that died out once it spread to, and through, humans. Europe’s famous plague seems to have been an entirely separate occurrence, but the scientists believe that both plagues originated in China and spread through the movement of people, animals, and other goods. The scientists also noted that the ancient plague isn’t so different from modern outbreaks, but that antibiotics prevent them from having the same devastating results.

As far as I know, the scientists have no plans to clone any organisms from that tooth.