Stage Master

The Laboratory of Molecular Anthropology of the Strasbourg Institute of Legal Medicine takes part in an interdisciplinary project alongside the University of Geneva to study and understand the resurgence of Syphilis, 70 years after the discovery of penicillin and its near eradication.
Our 20-year expertise in analysing ancient DNA will be applied to setting up a molecular biology testing method to detect and characterise treponemas in samples collected during the 19th and 20th centuries, from individuals suffering from syphilis, embedded in paraffin.
These samples, currently stored at the Strasbourg Institute of Anatomical Pathology (IAP), are complemented by histopathological microscope slides that were used for diagnosis. This presents a unique opportunity to implement a study of the phylogeny of the bacterium through the analysis of a large number of samples preserved before the use of penicillin. The proposed study of 19th and 20th century samples will allow us to give insight into ancient genetic diversity and the subsequent evolution of the pathogen.
The preliminary work of the M2 intern (November-December 2020) will consist in updating the available bibliography concerning Treponema sp. genomes and produce alignments of all published sequences, in order to identify which regions are shared between all species, subspecies and strains, and which regions are diagnostic of these strains. This will include a phylogenetic study of all available sequences.
From January to May 2020, the intern will develop different typing schemes that will allow the molecular identification of the different strains of T. pallidum found in paraffin-embedded samples, collected between 1950 and 1970. The results of these experiments will lead to the analysis of raw data, a second phylogenetic study and the production of a research article, to be published in an international peer-reviewed journal, describing the genetic epidemiology of Syphilis in Alsace during the 20th century and comparing it with current strain and subspecies diversity. This will allow us to highlight significant changes in the history of the pathogen.
Keywords: ancient DNA, bacterial genomes, bioinformatics, biostatistics, phylogenetics