Ancient Yersinia pestis strains lived long before the mass production of streptomycin or gentamicin. Because these bacteria did not evolve under the selective pressure of clinical medicine, they generally lack the specific resistance mechanisms found in modern hospital-acquired infections.
However, bacteria have always fought for survival in the soil. Many microorganisms produce natural antimicrobial compounds to kill competitors. Some ancient strains might carry innate resistance genes that happen to overlap with modern drug classes. This isn't resistance in the sense of a response to human medicine, but rather a byproduct of ancient ecological competition.
Current evidence suggests most permafrost-recovered plague strains remain susceptible to standard treatments. The real concern is the potential for these old strains to acquire new resistance plasmids if they interact with contemporary bacteria. Age does not automatically make a strain an untreatable superbug. It simply means we are dealing with a biological time capsule that may behave differently than current circulating variants.
