【英语时差8,16】抗生素历史（下）（在线收听）

Since that time, scientists have found that numerous species of fungi produce chemicals to destroy bacteria and that bacteria even produce chemicals that destroy other bacteria. Antibiotics are relatively new in modern medicine, but the earliest medical records from China, Egypt, and Mesopotamia show that people have used moldy and fermented substances to treat wounds for over three thousand years. The ability to produce these chemical toxins may have evolved in bacteria as a survival tactic. Today we use those same chemicals in our own struggle against bacteria.