As humans did not have the current means of recording events and knowledge of diseases, it’s difficult to study the history of humans and diseases. Rare gold mines of preserved genetic material come around once every so often, slowly giving us more and more insight into our fascinating past. This includes a project that utilized ancient nits to extract genetic information from mummified people in the Andes mountains and analyze the genome of Pompeians that were frozen in time by Mount Vesuvius.

The secrets of an Italian noble’s gallstone

Researchers from McMaster University and the University of Paris Cité have recently published a study that will add to our wealth of knowledge about ancient living things, sequencing the first ancient genome of the bacteria E.coli. The sample was extracted from the gallstone of a16th century mummy of an Italian noble, well preserved and buried in the Abbey of Saint Domenico Maggiore, in Naples.

How does E.coli impact us?

E.coli is a major public health concern, causing significant death and morbidity worldwide. What is interesting about the microorganism, however, is it is not a source of pandemics. E.coli is “commensal,” meaning an opportunistic bacteria that live within us and carefully chooses its time to strike, activating in times of disease, stress, or immune deficiency.

“A strict focus on pandemic-causing pathogens as the sole narrative of mass mortality in our past misses the large burden that stems from opportunistic commensals driven by the stress of lives lived,” says evolutionary geneticist Hendrik Poinar, principal investigator of the study.

Why is this important?

Despite its long relationship with the human race, we currently are unaware of E.coli’s historic impact on human health. This study starts to uncover this mystery, which is important in aiding researchers who are investigating other sneaky commensal pathogens. Plus, understanding the bacterium’s evolutionary history will give scientists clues into how it gained antibiotic resistance and will hopefully give us insight on how best to counteract it.

“We were able to identify what was an opportunistic pathogen, dig down to the functions of the genome, and provide guidelines to aid researchers who may be exploring other, hidden pathogens,” says Long.

Source study: Communications Biology – A 16th-century Escherichia coli draft genome associated with an opportunistic bile infection