Ancient human tooth samples used for TB paleomicrobial research

Questions about the evolution of tuberculosis and its pathogens are of primary importance in today’s research. We need a thorough understanding, both of the origins and history of the disease and of the evolutionary potential of its pathogens, in order to make valid prognoses for the future. Paleomicrobial analysis of ancient microbial DNA (aDNA) helps to identify human pathogens in human remains. During the last twenty years the application of modern biomolecular techniques, such as PCR, spoligotyping and DNA sequencing, in possible cases of skeletal tuberculosis has provided additional evidence for the differential diagnosis of ancient tuberculosis (e.g. Spigelman and Lemma 1993; Nerlich et al. 1997; Zink et al. 2001; Donoghue 2009). The presence of Mycobacterium tuberculosis (MTB) DNA in ancient human samples has confirmed morphological and radiological evidence of tuberculosis in archaeological human remains and furnished key material to understand the evolutionary history of the pathogen. The large majority of MTB aDNA studies used bone samples (mainly compact bone or vertebrae) or mummified tissues. Although, since the late nineties tooth samples have already been used successfully for the isolation of aDNA remains of other pathogens, e.g. for Yersinia pestis (Drancourt et al. 1998), they were only sporadically utilized in TB research. In a recent research project we tried to compare the preservation of mycobacterial aDNA in different bone elements and found a very heterogenous picture, indicating an important ‘chance factor’ in these researches (Pósa et al. 2012). In the newest phase of this project, tooth samples have also been used. We tested bone and tooth samples from two osteoarchaeological series from Hungary: the anthropological remains of the Bácsalmás-Óalmás and the Vésztô-Mágor sites. Our preliminary results prove the preservation of MTB aDNA in both series indicating the necessity to use parallel bone and tooth samples in further paleomicrobial analyses. Our future aims include a larger scale comparative investigation in order to precisely determine which anatomical elements of a human skeleton give the best MTB aDNA preservation

A Mycobacterium tuberculosis komplex archaikus DNS kimutatása humán csontvázmaradványokon

Tuberculosis (TB) is one of the oldest diseases and still has a high prevalence nowadays. The disease is pandemic, according to the estimation of the WHO 30% of total population of the world may be infected latently by Mycobacterium tuberculosis. Since the 1990s the identification of Mycobacterium tuberculosis infection has used molecular methods, too. Paleomicrobial research is also able to identify mycobacterial DNA from ancient human remains. In my examination I researched six historical periods for TB infection, the earliest period is Neolithic, a few samples from Tápé-Széntéglaégető archaeological site, which is a late Bronze Age (BC 14th–13rd century) cemetery, Avar Age samples (Szeged-Kiskundorozsma Kettőshatár II. (Grave No. 263 and Csárdaszállás-Hanzélytanya) are from the age of the Árpádian Dynasty. The skeletal material came from the Bácsalmás-Óalmás archeological site (AD 16th–17th centuries, southern Hungary) and the remains of Sándor Terézia from the Dominican church of Vác (AD 18th–19th centuries). During our research program we successfully adopted long standing paleomicrobiological techniques on the indigenous samples, and the TB infection was confirmed in four different ages. Our studies prove that this disease has accompanied the human population during its history – for 7000 years at least. The presence of tuberculosis has been proved in Hungary since the Neolithic, that is why it would be an interesting research topic if we could analyse more earlier periods in the near future. My research has revealed that the preservation of mycobacterial DNA is much more extensive in the case of long bones and teeth, than in the case of vertebrae or ribs. At the same time, data gained indicate the importance of the selection of the sample, as well as parallel sampling individually from long bones and teeth