Answer: I hope it helps!!
Explanation: I can't really explain on computer through a keyboard and stuff lol, but it's worked out. Please let me know if it's wrong :-)
I believe your answer is radioactive isotopes
Antibiotic resistance happens when an antibiotic lost its ability in controlling or killing bacterial growth. At this moment the bacteria are already resistant to the antibiotic and are multiplying even though the drug is present. This is a natural phenomenon.