Paleoparasitological and paleogenomic examination on coprolites from the Atacama Desert, Chile

RAMIREZ, DARIO A.; NICOLÁS, PASTOR; KIRKPATRICK, CASEY T.; SITTER, LESLEY T.; HERRERA-SOTO, MARIA J.; URIBE RODRIGUEZ, MAURICIO; SANTANA-SAGREDO, FRANCISCA; BOS, KIRSTEN I.; NORES, RODRIGO

Cochabamba

Congreso; IX Congreso de la Asociación de Paleopatología en Sudamérica; 2023

Asociación de Paleopatología en Sudamérica

Objective: The analysis of preserved feces recovered in archaeological sites worldwide has allowed to obtain insights into the diversity of parasites and microorganisms among ancient human populations. These studies have contributed to the knowledge of the composition of the microbiome of the individuals, the influence of cultural practices on the occurrence of certain species, the paleoenvironment scenario, and the relationship between humans and animals in the past. The aim of this work is to characterize the diversity of parasites and microorganisms present in camelid and human coprolites from the Atacama Desert in northern Chile. Materials and Methods: We processed 36 coprolites from both human and camelids, which were taken either directly from human mummified individuals (n=18) or from the surface or stratigraphy of an archaeological site (n=18). The samples were analyzed by light microscopy (n=36) and shotgun sequencing (n=16). The genomic data was processed with the bioinformatic pipeline HOPS (Heuristic Operations for Pathogen Screening) to distinguish true ancient DNA from modern DNA of environmental species, and identify species of interest. Results: Light microscopy observation revealed the presence of different helminth eggs and protozoa oocysts in 14 of the 36 samples. Additionally, DNA extraction and shotgun sequencing, followed by HOPS, allowed the screening of the whole genetic content of each sample, uncovering the community structure and composition of parasites and microorganisms in these ancient samples. Discussion: On the one hand, the parasite species identified in human coprolites suggest the consumption of raw on insufficient cooked marine resources by coastal groups, as well as the proximity between humans and canids, although they did not pose a health risk. On the other hand, camelid coprolites revealed the presence of pathogenic species that could have caused clinical manifestations, usually representing a thread to these animals’ lives.