Abstract:
The origins of treponemal diseases have long remained unknown, especially considering the sudden onset of the first syphilis epidemic in the late 15th century in Europe and its hypothesized arrival from the Americas with Columbus\' expeditions1,2. Recently, ancient DNA evidence has revealed various treponemal infections circulating in early modern Europe and colonial-era Mexico3-6. However, there has been to our knowledge no genomic evidence of treponematosis recovered from either the Americas or the Old World that can be reliably dated to the time before the first trans-Atlantic contacts. Here, we present treponemal genomes from nearly 2,000-year-old human remains from Brazil. We reconstruct four ancient genomes of a prehistoric treponemal pathogen, most closely related to the bejel-causing agent Treponema pallidum endemicum. Contradicting the modern day geographical niche of bejel in the arid regions of the world, the results call into question the previous palaeopathological characterization of treponeme subspecies and showcase their adaptive potential. A high-coverage genome is used to improve molecular clock date estimations, placing the divergence of modern T. pallidum subspecies firmly in pre-Columbian times. Overall, our study demonstrates the opportunities within archaeogenetics to uncover key events in pathogen evolution and emergence, paving the way to new hypotheses on the origin and spread of treponematoses.
摘要:
螺旋体疾病的起源长期以来一直未知,特别是考虑到15世纪后期欧洲首次梅毒流行的突然发作,以及哥伦布探险队1,2的假设从美洲到来。最近,古老的DNA证据表明,在早期的现代欧洲和殖民地时代的墨西哥3-6中流行着各种密螺旋体感染。然而,据我们所知,没有从美洲或旧世界发现螺旋体病的基因组证据可以可靠地追溯到第一次跨大西洋接触之前的时间。这里,我们展示了来自巴西的近2000年人类遗骸的密螺旋体基因组。我们重建了史前螺旋体病原体的四个古老基因组,与引起白热病的药物梅毒螺旋体流行最密切相关。与世界干旱地区Bejel的现代地理生态位相反,该结果对螺旋体亚种的先前古病理学特征提出了质疑,并展示了它们的适应潜力。高覆盖率基因组用于改进分子钟日期估计,将现代苍白球亚种的分歧牢牢地放在前哥伦布时代。总的来说,我们的研究表明,古细菌遗传学有机会发现病原体进化和出现的关键事件,为关于螺旋体病的起源和传播的新假设铺平了道路。