An international team led by researchers from McMaster University in Canada identified and reconstructed the first genome ancient bacteria Escherichia coli. This achievement was made possible thanks to parts of microorganisms extracted from gallstones found in Italian mummy It dates back to the sixteenth century.
search, Published in the magazine Communication biology Last Thursday (16), it helps reveal part of the evolutionary history of bacteria. The coli bacteria It can be found naturally in gut germs From humans and other animals, it can attack the host during periods of stress, illness, or immune deficiency. Although harmless in most cases, some strains are responsible for causing food poisoning Severe and with high morbidity and mortality. For this reason, the coli bacteria considered a problem Public Health.
Although it is very common, bacteria have never caused pandemicwhich means, according to the authors of the research, that the evolution of bacteria has not been studied like that of other microorganisms.
The strict focus on pandemic-causing pathogens as the only novel death rate The lump in our past ignores the significant burden that stems from opportunistic eating driven by the stresses of our lives,” says evolutionary geneticist Hendrik Poinar, director of the Center for Ancient DNA at McMaster University and principal investigator at the Michael J. DeGroot Institute for Research on Infectious Diseases from the same institution. The genome of a 400-year-old lineage was given to scientists by comparing this central lineage with bacteria And see how it has adapted and evolved since then.
the sample with coli bacteria From the sixteenth century it was exhumed from the mummy of Giovanni Davalos, a Neapolitan noble of the Renaissance who died at the age of 48, in 1586, of chronic inflammation caused by stones in the Gallbladder.
“When we were examining these remains, there was no evidence that this man had coli bacteria. Unlike an infection like smallpox, There are no physiological indicators. The study’s lead author, George Long, a graduate student in bioinformatics at McMaster, explains, “Nobody knows what it was.
However, the researchers were able to accurately isolate the fragments of the targeted bacteria, which were degraded by the environment and contaminated by various sources. They used the recovered materials for genome reconstruction.
“It was very exciting to be able to photograph this old one coli bacteria and to discover that, although unique, it belongs to a phylogenetic lineage characterized by symbionts that still cause gallstones today”, says Eric Dinamore, leader of the French team that was involved in characterizing the strain. The study was co-authored by researchers from the University of Pisa and the University of Paris. and the French Institute for Medical Research (Inserm) with support from the Canadian Institute for Advanced Research.
“We have been able to identify what the opportunistic pathogen is, investigate its genome functions, and provide guidelines to assist researchers who may explore other cryptic pathogens,” Long says.
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