Samples from mummified corpses, uncovered inside a two hundred year-old crypt in a Dominican church in Vac, Hungary, have exposed the origin of how the dreadful disease tuberculosis (TB) became widespread in Europe during the 18th century.
The research team, headed by University of Warwick, included researchers from University College London, University of Birmingham, the Hebrew University in Jerusalem and the Hungarian Natural History Museum in Budapest.
This medical research, published recently in the journal Nature Communications, enumerates how medical samples seized from the gruesome mummies, have produced fourteen tuberculosis genomes, indicating that mixed bacterial infections were frequent when tuberculosis was all over spreading in Europe.
"Microbiological analyses of samples from contemporary TB patients usually report a single strain of tuberculosis per patient. By contrast, five of the eight bodies in our study yielded more than one type of tuberculosis - remarkably, from one individual, we obtained evidence of three distinct strains," says Mark Pallen, a professor of microbial genomics at the University of Warwick in central England, who leads the latest probe.
They utilized a technique "metagenomics," an immediate sequencing of Deoxyribonucleic Acid (DNA) from specimens without cultivating bacteria or purposely seizing TB DNA, to classify TB DNA in the historical samples from the mummies. This procedure acquires on the significant output and effortless use of current DNA sequencing techniques.
"Poignantly, we found evidence of an intimate link between strains from in a middle-aged mother and her grown-up daughter, suggesting both family members died from this devastating infection," Gemma Kay, first author of the research noted.
All the specimens carried a genetic mark of an infamous tuberculosis strain known as Lineage 4, which at present accounts for more than a million TB victims every year in the Americas and Europe. By tracing the family tree of the germ, the research team dated the bacteria originating up to the late Roman era.
"By showing that historical strains can be accurately mapped to contemporary lineages, we have ruled out, for early modern Europe, the kind of scenario recently proposed for the Americas-that is wholesale replacement of one major lineage by another-and have confirmed the genotypic continuity of an infection that has ravaged the heart of Europe since prehistoric times," Prof. Pallen added.
Prof. Pallen mentioned also that with tuberculosis being resurgent in almost everywhere in the world, it will be a continuing process to control this ancient bacterial infection.
"We have shown that metagenomic approaches can document past infections. However, we have also recently shown that metagenomics can identify and characterize pathogens in contemporary samples, so such approaches might soon also inform current and future infectious disease diagnosis and control," Pallen concluded.
The study titled "Eighteenth-century genomes show that mixed infections were common at time of peak tuberculosis in Europe" was published in the journal Nature Communications.