5,000-Year-Old Bacteria Resistant to Modern Antibiotics Discovered

A bacterial strain preserved in ice within Romania’s Scărișoara Cave has shown resistance to ten modern antibiotics, researchers report in a new study published in the journal Frontiers in Microbiology, as cited by Euronews.

Scientists isolated the Psychrobacter SC65A.3 strain from an ice core extracted from a depth of approximately 25 meters in the cave, where the ice is roughly 5,000 years old. Genetic analysis reveals that the bacterium possesses over 100 genes associated with antimicrobial resistance and demonstrates resistance to antibiotics from eight different classes.

According to the study’s authors, the discovery indicates that antibiotic resistance existed naturally in the environment long before the advent of modern medicine. The scientists emphasize that while the phenomenon is natural, the widespread use of antibiotics in medicine and livestock farming accelerates the spread of resistant strains.

Scărișoara Cave contains one of the oldest underground ice deposits in the world—a block with a volume of about 100,000 cubic meters and an age of approximately 13,000 years. The analysis of microorganisms adapted to cold environments may help provide a better understanding of the evolution of antibiotic resistance, as well as potential risks to public health, the researchers state.

Antimicrobial resistance is among the leading global health threats; in Europe, it is linked to over 35,000 deaths annually, and globally, approximately one in every six bacterial infections no longer responds to standard treatment.