5,000-Year-Old Bacterium Found in Ice Is Resistant to Antibiotics
A team of researchers has identified an ancient bacterium frozen for approximately 5,000 years in the Scărișoara Ice Cave, Romania, exhibiting remarkable resistance to several antibiotics currently used in medicine—an observation that may reshape scientific understanding of the evolution of antimicrobial resistance.
The microorganism, identified as Psychrobacter sp. SC65A.3, was extracted from a deep ice layer and subjected to genomic and laboratory analyses, revealing the presence of more than 100 genes associated with antimicrobial resistance. Despite predating the invention of clinical antibiotics by millennia, the bacterium demonstrated resistance to at least ten modern antibiotics, including penicillins, cephalosporins, fluoroquinolones, and aminoglycosides.
Among the genes detected by researchers was mcr-1, known to confer resistance to colistin—a last-resort antibiotic used in severe infections.
In addition to multidrug resistance, the bacterium also exhibited antimicrobial activity against hospital-associated pathogens collectively known as the ESKAPE group, microorganisms frequently linked to drug resistance and difficult-to-treat clinical infections.
According to experts, the finding reinforces the concept that antibiotic resistance did not emerge solely as a consequence of clinical drug use but existed naturally in isolated and extreme environments long before the antibiotic era.
Scientists caution that frozen environments such as glaciers and ice caves may function as natural reservoirs of resistance genes, potentially releasing them as climate change accelerates the melting of ice masses.
At the same time, some researchers view the bacterium as a potential source of novel molecules or strategies to address the global antimicrobial resistance crisis—one of the most significant challenges facing modern public health.
The study on this bacterium was published in the scientific journal Frontiers in Microbiology and is already being cited in several international reports on microbial evolution and biotechnology.
