Molecular studies on ancient M. tuberculosis and M. leprae: methods of pathogen and host DNA analysis

Abstract

Humans have evolved alongside infectious diseases for millennia. Despite the efforts to reduce their incidence, infectious diseases still pose a tremendous threat to the world population. Fast development of molecular techniques and increasing risk of new epidemics have resulted in several studies that look to the past in order to investigate the origin and evolution of infectious diseases. Tuberculosis and leprosy have become frequent targets of such studies, owing to the persistence of their molecular biomarkers in ancient material and the characteristic skeletal lesions each disease may cause. This review examines the molecular methods used to screen for the presence of M. tuberculosis and M. leprae ancient DNA (aDNA) and their differentiation in ancient human remains. Examples of recent studies, mainly from Europe, that employ the newest techniques of molecular analysis are also described. Moreover, we present a specific approach based on assessing the likely immunological profile of historic populations, in order to further elucidate the influence of M. tuberculosis and M. leprae on historical human populations.

Fig. 1

Lesions typical of tuberculosis: a defects of proximal epiphysis of the tibia seen from above, b distorted distal end of the femur (Sypniewo, northeast Poland), c changes of the distal end of the left forearm and carpus (Ołbin in Wrocław, southwest Poland); lesions typical of leprosy: d defects in the palate, e fusion of the Lisfranc joint and atrophy of the first metatarsal bone (Suraż, northeast Poland) [4]

Fig. 2

Sequences in the TBD1 region received from strains of different geographic regions [45]

Fig. 3

Examples of analytical methods used to identify MTBC aDNA in selected European sites

Fig. 4

Examples of analytical methods used to identify M. leprae aDNA in selected European sites