It’s not the legendary Troy of Agamemnon and Paris, but the site of the ancient city is still giving up secrets to disease detectives who study the evolution of bacteria and other microbes that continue to cause illness in humans today.
An international team of scientists, including experts at McMaster University in Hamilton, have sequenced the genomes of two types of bacteria, whose DNA was preserved in calcified placental abscesses found in the skeleton of a woman who died in Byzantine Troy about 800 years ago.
The 30-year-old woman had been pregnant — researchers were able to extract the woman’s DNA and that of her male fetus — and had likely died of a urogenital infection caused by one or both of the bacteria, Gardnerella vaginalis and Staphylococcus saprophyticus, which cause genital and urinary tract infections in women to this day.
Her skeleton was unearthed by archeologists in a 13th-century graveyard on the outskirts of Troy, site of the fabled walled city besieged by Greek forces in Homer’s “Illiad,” located in what is now Anatolia in Turkey.
Co-principal investigator Hendrik Poinar, an evolutionary biologist at McMaster who specializes in ancient DNA, said analysis of genetic material preserved in the remains provides a snapshot of a massive maternal infection after the staph bacteria likely jumped from a cow to the woman. During that period, families typically lived with their livestock.
“It’s like capturing evolution in action in a fossil form that we rarely see.”
Discovery that the woman had suffered a devastating infection might not have occurred had it not been for the sharp eyes of Henrike Kiesewetter, an archeologist at Tubingen University in Germany, who was part of Project Troia, the dig at Troy.
Dr. Caitlin Pepperell, who led the genomic research with Poinar’s lab that was reported online Tuesday in the journal eLife, said Kiesewetter had spotted two calcified nodules below the woman’s ribs and thought they might be tubercles, lesions caused by tuberculosis that develop in the lungs.