Abstract

We analyzed 14 samples from the mummified remains of Sante Brancorsini, a 14th century Franciscan friar from central Italy, with macroscopic diagnosis of probable brucellosis. Shotgun sequencing data from 14 samples were examined to determine the presence of Brucella DNA . Three of the 14 samples contained authentic ancient DNA , identified as belonging to B. melitensis. A genome (23.81X depth coverage, 0.98 breadth coverage) was recovered from a kidney stone. Nine of the samples contained reads classified as B. melitensis (7-169), but for many of those, the data quality was insufficient to withstand our identification and authentication criteria. We identified significant variation in the preservation and abundance of B. melitensis DNA present across multiple tissues, with calcified nodules yielding the highest number of authenticated reads. Our results demonstrate variation in the preservation and recovery of pathogen DNA across tissues, from non-detectable to genome reconstruction, in an individual with a paleopathological diagnosis of brucellosis. This study highlights the importance of sample selection to the reconstruction of infectious disease burden and highlights the importance of a holistic approach to identifying disease in the past. Further analysis of how sampling impacts aDNA recovery will improve pathogen aDNA recovery and advance our understanding of disease in past peoples.