As soon as scientists figured out how to harness the power of antibiotic drugs, bacteria hit back. Following clinical trials of penicillin around 1941, doctors documented the spread of penicillin-resistant Staphylococcus aureus among hospital patients in 1942. By the late 1960s, more than 80 percent of S. aureus bacteria isolated in and out of hospitals turned up resistant to the revolutionary drug.
It’s a common pattern that has led to the crisis of antibiotic resistance the world is now facing. In 1945, Alexander Fleming himself—the discoverer of penicillin—even warned of such “an era… of abuses,” in which strong public demand for antibiotics would drive bacterial resistance that render the “miraculous” drugs impotent.