Prime Highlights
- Researchers discovered a 5,000-year-old bacterial strain, Psychrobacter SC65A.3, in Scărișoara Cave ice that is resistant to 10 modern antibiotics.
- The finding shows that antibiotic resistance existed in nature long before humans began producing and using antibiotics.
Key Facts
- The bacteria carry over 100 genes linked to antibiotic resistance, affecting drugs used to treat tuberculosis, colitis, and urinary tract infections.
- The discovery was made by drilling a 25-meter ice core in Romania’s Great Hall and sequencing bacterial genomes, with results published in Frontiers in Microbiology.
Background
Researchers have discovered a 5,000-year-old strain of bacteria preserved in ice that shows resistance to several modern antibiotics.
The strain, identified as Psychrobacter SC65A.3, was found deep inside Scărișoara Cave, one of Romania’s largest underground ice caves. Scientists extracted the bacteria from ice layers believed to be around 5,000 years old. The cave itself contains an ice block estimated to be 13,000 years old and measuring about 100,000 cubic meters.
The research team drilled a 25-meter ice core from an area known as the Great Hall. After analysing ice fragments, they isolated several bacterial strains and sequenced their genomes. Tests revealed that Psychrobacter SC65A.3 is resistant to 10 modern antibiotics across eight different classes.
Cristina Purcarea, a scientist at the Institute of Biology Bucharest of the Romanian Academy and lead author of the study, said the strain carries more than 100 genes linked to antibiotic resistance. She noted that many of the antibiotics to which the bacteria showed resistance are commonly used in treating serious infections such as tuberculosis, colitis and urinary tract infections.
The researchers published their findings in Frontiers in Microbiology. They show that bacteria had antibiotic resistance in nature long before humans started making and using antibiotics.
Researchers explained that antimicrobial resistance is a natural process, but has accelerated due to widespread antibiotic use. With nearly 20% of Earth’s surface covered by frozen habitats, understanding cold-adapted microbes becomes more important, especially as climate change may release ancient microorganisms.
Health agencies continue to warn about rising resistance. The World Health Organization estimates that one in six bacterial infections worldwide is resistant to standard treatments. The European Centre for Disease Prevention and Control has also flagged growing cross-border spread and overuse of antibiotics in Europe.
Scientists say studying ancient microbes may help explain how resistance evolved and guide future efforts to control its spread.
