Downloaded from www.microbiologyresearch.org by IP: 54.157.246.241 On: Fri, 13 Jan 2017 18:26:34 First report of Mycobacterium bovis DNA in human remains from the Iron Age G. Michael Taylor, 1 3 Eileen Murphy, 2 Richard Hopkins, 1 Paul Rutland 3 and Yuri Chistov 4 Correspondence G. Michael Taylor gm.taylor@ucl.ac.uk 1 Centre for Molecular Microbiology and Infectious Diseases, Imperial College of Science, Technology and Medicine, London SW7 2AZ, UK 2 School of Geography, Archaeology and Palaeoecology, Queen’s University Belfast, Belfast BT7 1NN, UK 3 Department of Genetics, Institute of Child Health, University College London, London WC1N 1EH, UK 4 Peter the Great Museum of Anthropology and Ethnography (Kunstkamera), 3 University Embankment, St Petersburg 199034, Russia Received 4 September 2006 Revised 26 November 2006 Accepted 19 December 2006 Tuberculosis has plagued humankind since prehistoric times, as is evident from characteristic lesions on human skeletons dating back to the Neolithic period. The disease in man is due predominantly to infection with either Mycobacterium tuberculosis or Mycobacterium bovis, both members of the M. tuberculosis (MTB) complex. A number of studies have shown that when conditions permit, surviving mycobacterial DNA may be amplified from bone by PCR. Such ancient DNA (aDNA) analyses are subject to stringent tests of authenticity and, when feasible, are invariably limited by DNA fragmentation. Using PCRs based on single-nucleotide polymorphic loci and regions of difference (RDs) in the MTB complex, a study was made of five Iron Age individuals with spinal lesions recovered from the cemetery of Aymyrlyg, South Siberia. A sensitive screening PCR for MTB complex mycobacteria was positive in four out of the five cases. Genotyping evidence indicated that all four cases were due to infection with M. bovis rather than M. tuberculosis and the data were consistent with the proposed phylogenetic model of the MTB complex. This is believed to be the first report of M. bovis causing Pott’s disease in archaeological human remains. The study shows that genotyping of ancestral strains of MTB complex mycobacteria from contexts of known date provides information which allows the phylogeny of the model to be tested. Moreover, it shows that loss of DNA from RD4, which defines classic M. bovis, had already occurred from the genome over 2000 years before the present. INTRODUCTION Tuberculosis is a chronic infectious pulmonary disease which is caused in humans primarily by Mycobacterium tuberculosis and more rarely by Mycobacterium bovis. M. tuberculosis is transmitted predominantly from human to human via droplet respiratory infection when an infected individual coughs or sneezes (Roberts & Buikstra, 2003). The human-to-human transmission of tuberculosis is reliant on the existence of groups of individuals living in close proximity to one another. The bovine form of tuberculosis is transmitted from animals (such as cattle) to humans through infected milk or meat and is consequently primarily a disease of the stomach and intestinal tract, although it can cause respiratory disease (Cotter et al., 1996; LoBue et al., 2004; Thompson et al., 1993). In developed countries such as the UK, where control measures and herd testing have been in place since the 1930s, bovine tuberculosis accounts for <1 % of human tubercu- losis cases and tends to be a disease associated with those in close proximity to livestock, such as farmers, veterinary surgeons and abattoir workers (Gutierrez et al., 1997; Robinson et al., 1988; Smith et al., 2004). As such, it is considered to be a spillover infection in humans and is seldom self-maintaining (O’Reilly & Daborn, 1995). In a small percentage of cases, tuberculosis may affect the skeleton, giving rise to characteristic lytic lesions with minimal new bone formation (Ortner & Putschar, 1985). 3Present address: Centre for Infectious Diseases and International Health, Windeyer Institute, University College London, 46 Cleveland Street, London W1T 4JF, UK. Abbreviations: aDNA, ancient DNA; AMS, accelerator mass spectro- scopy; BP, before the present; DR, direct repeat; MTB complex, Mycobacterium tuberculosis complex; RD, region of difference. 2006/002154 G 2007 SGM Printed in Great Britain 1243 Microbiology (2007), 153, 1243–1249 DOI 10.1099/mic.0.2006/002154-0