Sequence analysis of bacterial DNA in the colon and stomach of the Tyrolean Iceman

Abstract

The male human body found in an Alpine glacier on September 19, 1991 ("Tyrolean Iceman") has, for the first time in history, given scientists a chance to perform detailed anatomical, histological, and molecular investigations on the organs of a person from the Neolithic Age (5350-5100 B.P.). In the present study, tissue samples aseptically taken from the stomach and the colon of the mummy were utilized for DNA extraction, and the DNA was PCR-amplified, using primer pairs designed to bind to fragments of the 16s ribosomal RNA gene (16s rDNA) of a broad range of bacteria. The PCR products were cloned in plasmid vectors, and the recombinant clones (amplicons) were sequenced. The sequence data were finally used for scanning data libraries containing the corresponding sequences of present-day bacteria, to infer the putative ecophysiology of the ancient ones. The same procedure was repeated on some fragments of grass from the clothing found near the corpse. These fragments were taken as a control of the microbiological situation of the glacier. The results show that the flora of the Iceman's stomach is entirely composed of Burkholderia pickettii, an organism commonly found in aquatic habitats. The colon, on the other hand, contains several members of the fecal flora of humans, such as Clostridium perfringens, C. ghonii, C. sordellii, Eubacterium tenue, and Bacteroides sp. The Iceman's colon, however, was found to contain, rather unexpectedly, also some members of the genus Vibrio. The results are discussed in light of what is known about the preservation of microbial DNA at the Iceman's site and of previous parasitological studies performed on the Iceman himself and on human coprolites.

Comparison of the anaerobic microbiota of deep-water Geodia spp. and sandy sediments in the Straits of Florida

“…In both the sponge and sediment samples, most sequences obtained from obligate anaerobes were most closely associated with uncultured bacterium 08SE (accession number AF018038) from the gut of the Tyrolean iceman (Cano et al, 2000). BLAST analysis further revealed the sequence to be a member of the Clostridium spp.…”

Analysis of ancient DNA from coprolites: a perspective with random amplified polymorphic DNA-polymerase chain reaction approach

“…Only recently, DNA from coprolites was analyzed in order to determine plant and animal components of diet (Poinar et al 1998, bacterial flora, and parasitic infection (Cano et al 2000, Loreille et al 2001. Usually these techniques target ribosomal, chloroplast, or mitochondrial genes and then the real nature of the amplicons are determined by nucleotide sequencing analysis.…”

“…Gene fragments from eukaryotic and prokaryotic organisms have been successfully detected from human bones and tissues (Fricker et al 1997, Ubaldi et al 1998, Gulh et al 1999, Cano et al 2000, Ferreira et al 2000, Zink et al 2001. All of these studies focused on the recovery of aDNA from a specific organism or a determined gene sequence.…”

Ötzi's last meals: DNA analysis of the intestinal content of the Neolithic glacier mummy from the Alps

“…Practically it is assumed that a D͞L-Asp higher than 0.08-0.1 (uncorrected for racemization caused by the experimental procedure) indicates that no authentic DNA is left in an archaeological sample, whereas lower values are compatible with its conservation (18). In a previous investigation (14), we determined the D͞L-Asp for tissue samples from the Iceman's corpse and found it to be in the range of 0.06-0.08. In the present study, we analyzed fragments of grass from the outer clothing of the hunter͞warrior and found D͞L-Asp ratios ranging between 0.06 and 0.07.…”

“…For the Tyrolean Iceman, evidence that the ancient DNA is preserved was repeatedly given in the past by showing that not only the original mitochondrial DNA of the man (13), but also that of his intestinal microflora (14), and that of the grass clothing (15) could be retrieved. In addition, the present work was conducted following the guidelines of Cooper and Poinar (16).…”