ANCIENT PATHOGENS

Ancient skeletal and soft tissue samples can still contain traces of the original bacterial DNA. This applies both to the DNA of human commensals (e.g. intestinal bacteria) and to the genetic material of pathogens. Thereby, genome wide analysis of ancient pathogens provides information on the onset and spread of chronic infectious diseases such as tuberculosis or leprosy and helps to identify the causative agents of major human epidemics such as the plague. Furthermore, the metagenomic study of ancient human microbiomes provide novel insights into the composition and possible changes of human microbial communities over the last millennia. The biomolecular investigation of pathogens in ancient human remains represents an emerging field of research which provides considerable insight into the history and evolution of infectious diseases. The applied diagnostic approaches in paleomicobiology range from the histological detection to the PCR-based characterization of ancient pathogens. More recently, the era of high-throughput sequencing paved new ways to analyze ancient DNA resulting e.g. in the first complete genome of the causative agent of Black Death, Yersinia pestis. However there are obstacles yet to overcome such as the limitations of PCR-based approaches in analyzing highly degraded ancient DNA extracts or the development of bioinformatics pipelines to screen complex metagenomic datasets for ancient pathogens.

The aim of this project will be to improve the DNA-based detection of the microbiome incl. pathogens in ancient human remains. To further optimize molecular diagnostics approaches the EURAC Institute for Mummy Studies has access to an variety of tissue samples with possible tuberculosis, brucellosis and malaria infection. Moreover, together with our cooperation partner from Vienna and Stockholm we are analyzing the metagenomic data of the Iceman´s genomic survey in order to establish a bioinformatics pipeline for the de novo detection of commensals and pathogens in metagenomic datasets of ancient human remains. Thereby obtained knowledge is currently also applied to shotgun datasets of Tuberculosis positive skeletal material. In addition we seek for molecular traces of other diseases such as e.g. leprosy, syphilis, malaria and plague in ancient human remains.