Salmonella enterica from a soldier from the 1652 siege of Barcelona (Spain) supports historical transatlantic epidemic contacts.

Ancient pathogen genomics is an emerging field allowing reconstruction of past epidemics. The demise of post-contact American populations may, at least in part, have been caused by paratyphoid fever brought by Europeans. We retrieved genome-wide data from two Spanish soldiers who were besieging the city of Barcelona in 1652, during the Reapers' War. Their ancestry derived from the Basque region and Sardinia, respectively, (at that time, this island belonged to the Spanish kingdom). Despite the proposed plague epidemic, we could not find solid evidence for the presence of the causative plague agent in these individuals. However, we retrieved from one individual a substantial fraction of the Salmonella enterica serovar Paratyphi C lineage linked to paratyphoid fever in colonial period Mexico. Our results support a growing body of evidence that Paratyphi C enteric fever was more prevalent in Europe and the Americas in the past than it is today.