Scientists reveal cause of death of mummified Basel woman

A museum curator presents the mummy at a news conference five years ago. © Keystone / Georgios Kefalas

A well-preserved mummy discovered 48 years ago in a former church in the Swiss city of Basel very likely contracted a rare and previously unknown bacterial infection, according to a new study.

The previous suspicion of syphilis could not be confirmed.

The research team led by anthropologist Gerhard Hotz from the Natural History Museum in Basel and Mohamed Sarhan from the Institute for Mummies Studies in Bolzano (Italy) wanted to detect the DNA of the bacterial pathogen that causes syphilis by means of molecular genetic analyses, a statement from the Natural History Museum in Basel said on Tuesday.

Instead, the archaeogeneticists found a high concentration of a previously unknown, non-tuberculous species of mycobacterium in the tissue samples of the mummy’s brain. This bacterium belongs to a group which includes the pathogens of leprosy and tuberculosis.

The results of the study were recently published in the scientific journal BMC Biology.

The body, found in 1975, is that of 67-year-old Anna Catharina Bischoff, who was born in 1719 in Strasbourg, France, and died in 1787 in Basel. She is believed to be a great-great-great-great-great-great-great grandmother of the former British prime minister, Boris Johnson, according to researchers. 

The mummy was buried in the family tomb of Isaak Bischoff, a hospital director in 17^th-century Basel, in the city’s Barfüsser church. Its identity had eluded researchers for decades.