Molecular detection of Mycobacterium tuberculosis complex in the 8 th century skeletal remains from the territory of Slovakia

DNA was extracted using a Silica Bead Extraction kit from bone samples taken from a Slavonic-Avar individual found at the archaeological site of Cífer-Pác. The analysed skeletal remains from the grave number 62/79 belong to a young adult male (20–30 years at death) and are dated to the 8 th –9 th century anno Domini. The isolated ancient DNA (aDNA) was amplified by a targeted PCR with a primer pair designed to recognize the Mycobacterium tuberculosis complex insertion sequence IS6110. The aim of this molecular approach was to test and optimize a methodology for aDNA M. tuberculosis complex extraction from bone samples with osteological evidence of tuberculosis. Despite of the currently biased authenticity of the mentioned fragment, in this case study we prove that macroscopic evidence for tuberculosis additionally supported by a positive result of molecular testing can be considered authentic enough to be the proof of a tuberculosis infection caused by MTBC ( Mycobacterium tuberculosis complex) bacteria when additional skeletal trauma and changes potentially caused by MOTT (mycobacteria other than tuberculosis) bacteria can be excluded. Positivity was confirmed in all of the three samples (thoracic vertebrae, lumbar vertebrae and right femur). Our results confirmed the diagnosis of tuberculosis of the spine and right hip joint. This is the first molecular evidence for the occurrence of tuberculosis on the territory of Slovakia. Through this bio-molecular approach we wish to provide a basis for aDNA examinations on other skeletal collections and provide epidemiological data concerning historical populations living on the territory of Slovakia.