The bacterium that causes syphilis was discovered in America at least a thousand years before Columbus.

One of the biggest mysteries in the history of epidemics is whether syphilis was introduced from Europe. after Columbus’s first voyage to America. Now a study conducted by the University of Basel (Switzerland) has confirmed the presence of one of treponematotic diseasescalled bedel (a disease similar to syphilis), in South America at least 1000 years before the arrival of the Spaniards.

Its existence suggests that bacterial family The cause of these diseases was dissipated even before the European expeditions of the 15th and 16th centuries.

In a study published this week in Natureoldest known genome Treponema pallidum, bacteria that cause treponematoses, in prehistoric human remains from Brazil. This work, which involved the University of Valencia, the Foundation for the Promotion of Health and Biomedical Research of the Valencian Community (Fisabio) and the Autonomous University of Barcelona, ​​contributes to elucidating the origin of this group of diseases, according to the authors.

Treponematoses are infectious diseases caused by bacteria. T. pallidum. Although endemic forms such as yaws and bejel are generally found only in developing countries, syphilis persists as a global infection. These infections have re-emerged in recent years and are largely resistant to azithromycin, which is used as an alternative treatment to penicillin, with subsequent impacts on public health.

Four bacterial genomes obtained and analyzed for this study. They were recovered from human remains approximately 2,000 years old.found on a burial mound in the Santa Catalina region of Brazil.

The analyzed bones were found in the so-calledsambacs‘: shell mounds where Brazil’s first coastal inhabitants buried their dead.

Luis Peso-Lanfranco The UAB researcher and co-author of the paper recalls that “sambaci were made from shells, sand and black soil, and sedentary fisher-hunter-gatherers performed complex rituals here” This expert specializes in studying the diet and oral health of these populations.

The importance of archaeogenetics

Until now, it has not been possible to identify the types of bacteria that have caused serious infections and epidemics in the past. depended mainly on data in bone material samples. Nowadays, thanks to recent advances in methods for studying ancient DNA, such as the one used in this study, it is possible not just reconstruct ancient genomesbut rather to identify the specific subtype causing the infection.

These surprising discoveries, such as the identification of a prehistoric bedel agent in coastal America, highlight the potential of ancient DNA. beyond conclusions based on modern pathogen genomes or purely archaeological interpretations.

Findings like the one proposed in this study demonstrate the potential of studying ancient DNA to advance knowledge of modern pathogens. So much so that when analyzing one of the infectious agents discovered in Brazil, it was found to bear such a close resemblance to modern bejel strains (T. pallidum endemicum) that this subspecies appears to have remained virtually unchanged to this day.

Ancient genomes that speak to the present

“Although we cannot pinpoint the precise timing of these events, our analysis helps clarify what the evolution of these pathogens must have been like, since Bacteria are capable of passing genes from one to another (horizontal gene transfer or recombination), and this affects its structure. Thus, this fact allows us to understand the contact that different subspecies of the same treponemal bacteria had and helps us understand their evolutionary path,” he explains. Marta Pla Diazone of the first authors of the study and a researcher at the UF and the University of Basel (Switzerland).

In his doctoral thesis in Valencia, Pla developed methods for analyzing evolutionary processes, such as such as selection and recombination and horizontal gene transfer. in the genomes of ancient and modern bacteria, making it easier to study complex data like those included in this study.

“Inclusion of ancient genomes in the analysis is necessary to understand what factors and evolutionary processes were at work in the past, and in the case of T. pallidumhow, when and, hopefully, where, led to the emergence of a new pathogen that has caused, over the last five centuries, a pandemic as serious as syphilis,” explains the professor at the University of Valencia. Fernando Gonzalez Candelastook part in the study.

As research progresses and assessments improve, the goal of disclosure origin of syphilis one step closer. “The origins of syphilis are still unknown, but at least we now have no doubt that infections caused by Treponema bacteria were not alien to the inhabitants of the Americas, who lived and died centuries before the first European explorers arrived on this continent.” , adds Gonzalez Candelas.

Link:

Kerttu Mahander et al. “Rethinking Treponema History through Pre-Columbian Genomes from Brazil.” Nature (2024).