Bioarchaeological investigation of a 800-years-old skeleton dated to Byzantine times, found near the site of the ancient city of Troy led to the discovery of two large calcified nodules nested below the ribs at the base of the chest. They possible were the reason behind the death of the 30 year old woman.

Initially the researchers believed the nodules to be tubercles arising from tuberculosis, as bacterial infection, tuberculosis is characterized, often, by the growth of calcified nodules in the lungs or other tissues. However their DNA, elemental and microscopic analysis ruled out tuberculosis as well as urinary or kidney stones as possibilities. After opening the nodules revealed microfossils of mineralised bacteria from the genus Staphylococcus, a family that includes the highly pathogenic species S. aureus.

Further DNA analysis allowed to fully reconstruct the genomes of two species of bacteria, Staphylococcus saprophyticus and Gardnerella vaginalis. According to the experts these bacteria possibly infected the woman and likely led to her death. The DNA of the bacteria survived due to calcification. Moreover, the nodules contained human DNA of the woman and what looks to be her male foetus, as she was possibly pregnant at the time of death. According to the study of the skeleton the cause of the woman’s death, which occurred in the waning decades of the Byzantine Empire, was chorioamnionitis, a bacterial infection of the placenta, amniotic fluid and membranes surrounding the foetus.

(after Journal Sentinel, University of Wisconsin-Madison, EurekAlert, Pathologie Nordhessen & Gebhard Bieg)