Research has found that an ancient bacteria is resistant to multiple modern antibiotics.

A recent study published in the international academic journal "Frontiers in Microbiology" shows that an ancient bacterium found in an ice cave in Romania, with a history of thousands of years, is resistant to multiple modern common antibiotics, indicating that bacterial resistance can form through natural evolution. This bacterium was found in an ice layer formed about 5000 years ago in an ice cave in Romania. Researchers from the Romanian Academy of Sciences Institute of Biology in Bucharest and other institutions drilled a 25-meter ice core in the cave, isolating multiple strains of bacteria and conducting genome sequencing analysis to study their cold resistance mechanisms and antibiotic resistance-related genes. Researchers tested one strain of psychrophilic bacteria named SC65A.3, using 28 types of 10 major classes of clinically common or reserve antibiotics, and found that it exhibited resistance to 10 antibiotics, including levofloxacin, vancomycin, and ciprofloxacin, which are used to treat common infections. SC65A.3 is also the first psychrophilic bacterium strain discovered to be resistant to antibiotics such as metronidazole, clindamycin, and nitrofurantoin. The study also found that SC65A.3 carries over a hundred genes related to antibiotic resistance, can inhibit the growth of multiple multidrug-resistant "superbugs", and has special enzyme activity with potential for biotechnological applications. The researchers believe that strains able to survive in cold environments may serve as natural reservoirs of antibiotic resistance genes.