How microbial ancient DNA, found in association with human remains, can be interpreted

Abstract

human mummies insertion sequence (IS)-like element 1361 bp in length, called IS6110. The presence of this element in M. tuberculosis has been shown to correlate closely with clinically diagnosed tuberculosis. In ancient Europe, tuberculosis was one of the most widely prevalent infectious diseases. Incidence in bone pathology in skeletal remains from medieval Lithuania suggests that 18^25% of the population su¡ered from it. Faerman et al. (1997) detected the presence of M. tuberculosis in skeletal remains from Lithuania, dated to the 15th ^17th centuries, by amplifying a portion of the IS6110 element, and found that a much higher percentage of individuals was infected than had previously been thought. For what concerns the important issue of the pathogenic eukaryotes (protozoans), Taylor et al. (1997) have developed a hemi-nested PCR method for amplifying Plasmodium nucleic acid. Their method detects all four malaria-producing Plasmodium species pathogenic to humans and was designed to amplify small fragments of DNA likely to remain in archaeological specimens. The method has been applied to two human ribs from separate individuals who had died almost 60 years previously from anaemia, thought to be due to malaria. Plasmodium DNA was con¢rmed in one of these cases; subsequently, sequencing of the PCR product identi¢ed the causative species as Plasmodium falciparum. It is important, however, to note that when the test was applied to the Granville mummy the result was negative. This mummy is of a female aged about 50 years from the site of Gurna (Egypt) (approximately 700 BC) and had previously been reported positive for Plasmodium falciparum using immunological methods.