From the "teeth of the dead" highlighted the actual condition of infectious diseases that forced the Aztec civilization in Mexico into a devastating situation in the 16th century

BySiddie Nam

Spanish in 1519Hernán CortésHas landed in Mexico for decades there has been a devastating situation among the Aztecs who are indigenous peoples, the worst epidemic epidemic of humanity history spread. When investigating the teeth of the dead at the time of burial, the possibility that the cause was a kind of "salmonella" emerged.

Salmonella enterica genomes from victims of a major sixteenth-century epidemic in Mexico | Nature Ecology & Evolution
https://www.nature.com/articles/s41559-017-0446-6

A New Clue to the 1545 Cocolitzli Epidemic in Mexico - The Atlantic
https://www.theatlantic.com/science/archive/2018/01/salmonella-cocoliztli-mexico/550310/

A devastating epidemic in Mexico in the 16th century is thought to be caused by Salmonella | Nature Ecology and Evolution | Nature Research
http://www.natureasia.com/ja-jp/research/highlight/12328

This research was promoted by research teams such as Krsten Bos, anthropologist of Max Planck Human Science Laboratories. We analyze the samples contained inside the teeth of the inhabitants who died of infectious diseases to extract the DNA of pathogens and clarify the cause of the destruction of the Aztecs on the verge of ruin.

The Spaniards who landed in Mexico in the 16th century are said to have brought many diseases such as smallpox, measles, typhus, etc. to the locality, and local people collectively call these "CocoritriIt was said that he called it. The first epidemic occurred in 1545, then the damage will expand again in 1576. Every time there are millions of people killing each other, the population of Aztec civilization seems to have drastically decreased from 20 million to 2 million, the Franciscan monks who witnessed the situation said " In the evening, the priests carried corpses and threw them into the ditch and buried them. "


The detail of this cocorte has not been clarified so far and it has been thought that it is a disease such as smallpox or measles, but its accurate appearance has been clarified by using the latest DNA analysis technology It is. Mr. Boss who conducted the study said that a massiveMishtecaI took out the teeth of the dead who were buried in the cemetery of Nagasaki and investigated the DNA of the pathogen left in it in detail.

It is a soft and living tissue in teethpulpMany blood vessels pass through, and all the pathogens that have entered the blood flow into the pulp. And after the patient's death, hard enamel on the outside of the tooth will play the role of protecting the DNA of pathogens spanned for centuries. Mr. Boss uses a new technique to extract DNA from traces of blood, so that the pathogen is a kind of pathogenSalmonellaIt has a DNA base sequence of.

ByJohn Patrick Robichaud

This pathogen is called "Salmonella enterica" ​​or "S. enterica" ​​which means "bacteria that cause typhus", and as a result of this bacterium being found this time, the epidemic diseases that became one of the reasons to drive the Aztec civilization into ruin are typhus It is strongly supporting that it was. Furthermore, the fact that S. enterica is not included in the five pulp samples died before the Spanish landed also supports this theory. Typhus' fever spreads through food and water contaminated with sick people's feces, and in modern society a lot of people are densely populated in a poor environment.

The paper also acknowledged that Salmonella might have interacted with other pathogens, and the method used this time also holds the possibility. While this method can only detect DNA, research teams acknowledge that some viruses are dividing by RNA, so there are other factors that could not be found with this method.

However, analytical methods using old DNA are expected to become clues to know the past situation that we could not know until now. French public university ·Aix-Marseilles University"This new step in the field of old DNA will lead to the attention of bacteria that are symbiotic to human beings", said Nicholas Rascovan, a microbiologist.