The recently sequenced genome of the bacterium Treponema pallidum, which causes syphilis, underscores the deep antiquity of treponemal maladies in the Americas. Findings based on a 5500-year-old sample from Colombia suggest that the emergence of syphilis was not dependent on the intensification of agriculture and overpopulation frequently linked to the spread of infectious diseases. Instead, it hinged on the social and environmental settings of hunter-gatherer societies.
“Reframing syphilis, alongside other infectious ailments, as a product of both local and highly specific evolutionary, ecological, and biosocial conditions, as well as globalization, might represent significant strides toward reducing stigmatization and bettering public welfare,” write Molly Zuckerman and Lydia Ball in the corresponding article published in Science.
Treponemal diseases such as syphilis, yaws, bejel, and pinta have afflicted humankind across much of the globe for millennia. Nonetheless, much regarding the global age and dispersal of these illnesses, as well as the evolutionary history of the bacteria that cause them, remains unknown. Among the most debated issues is the geographic origin and worldwide spread of syphilis, caused by T. pallidum. Some posit the ailment arose in the Americas and was conveyed to the Old World following European contact in the late fifteenth century. Others hold that the treponeme was already present in Europe before contact. Still, the scarcity and ambiguity of skeletal evidence for these diseases, coupled with the technical hurdles of extracting archaic bacterial DNA from afflicted remains, complicate resolving these matters.
David Bocqueti and associates presented a 5500-year-old Treponema genome discovered in Middle Holocene hunter-gatherer remains in Colombia. The novel data extend the known genetic history of this pathogen by roughly 3000 years. According to Bocqueti and co-authors, phylogenetic analysis indicates that this genome (TE1-3) represents a previously unrecognized branch of T. pallidum, one that split before the advent of all other known subspecies. While clearly belonging to the T. pallidum species, TE1-3 is genetically diverse and distinct from contemporary strains. Notably, the researchers determined that TE1-3 also possesses the full complement of genetic characteristics associated with virulence in modern T. pallidum.
Furthermore, the study’s outcomes demonstrate that T. pallidum existed prior to the advent of farming in the Americas, indicating that the pathogen’s genesis was unreliant on the intensification of agriculture and overpopulation often tied to infectious disease propagation. Rather, the TE1-3 lineage is linked to the social and ecological conditions of hunter-gatherer societies, including high mobility, interaction within small bands, and close contact with wildlife. Bocqueti et al. assert that the findings broaden the temporal, ecological, and social parameters for comprehending global treponemal ailments.
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