New Technique IDs Tuberculosis in 215-Year-Old Mummy
Scientists have recovered tuberculosis genomes from lung tissue of a two-century-old Hungarian mummy.
Using a technique called metagenomics, researchers at the University of Warwick were able to identify tuberculosis DNA in a 215-year-old specimen.
Researchers said "metagenomics" refers to the open-ended sequencing of DNA from samples without the need for culture or target-specific amplification or enrichment. The sample came from a Hungarian woman, Terézia Hausmann, who died aged 28 on 25 December 1797. Researchers said that her remains were found in a crypt in the town of Vác, Hungary
When researchers opened the crypt in 1994, they found 242 naturally mummified bodies. Researcher said that molecular analyses of the woman's chest sample confirmed the diagnosis of tuberculosis and hinted that TB DNA was extremely well preserved in her body.
"Most other attempts to recover DNA sequences from historical or ancient samples have suffered from the risk of contamination, because they rely on amplification of DNA in the laboratory, plus they have required onerous optimization of target-specific assays," lead researcher Professor Mark Pallen said in a news release.
"The beauty of metagenomics is that it provides a simple but highly informative, assumption-free, one-size-fits-all approach that works in a wide variety of contexts," he explained.
"A few months ago we showed that metagenomics allowed us to identify an E. coli outbreak strains from fecal samples and a few weeks ago a similar approach was shown by another group to deliver a leprosy genome from historical material," Pallen added.
The findings, published in the New England Journal of Medicine, revealed that Terézia Hausmann suffered from a mixed infection with two different strains of the TB bacterium. Researchers said that the study, combined with other studies on tuberculosis, highlights the importance of mixed-strain infections, particularly when tuberculosis is highly prevalent.
"It was fascinating to see the similarities between the TB genome sequences we recovered and the genome of a recent outbreak strain in Germany. It shows once more that using metagenomics can be remarkably effective in tracking the evolution and spread of microbes without the need for culture -- in this case, metagenomes revealed that some strain lineages have been circulating in Europe for more than two centuries," Pallen concluded.