© 2026. The Trustees of Indiana University
Copyright Complaints
1229 East Seventh Street, Bloomington, Indiana 47405
News, Arts and Culture from WFIU Public Radio and WTIU Public Television
Play Live Radio
Next Up:
0:00
0:00
0:00 0:00
Available On Air Stations

Sir Alexander Fleming, Penicillium, And The History Of Antibiotics

When you take an aspirin, a decongestant, or a muscle relaxant, the drug you're taking was probably made by a chemist combining a specific mixture of chemicals.

Microscopic Fungi And Bacteria

Antibiotics, on the other hand, are chemicals produced by microscopic fungi or bacteria as part of their normal biological processes.

Pharmaceutical companies grow the microorganisms, collect the chemicals they produce, and sell the chemicals as antibiotics.

To see how antibiotics work in nature, it may help to look at the discovery of the first antibiotic.

History Of Antibiotics

In 1928, Sir Alexander Fleming was studying Staphylococcus bacteria when one of the bacterial cultures became infected with a fungus called "penicillium."

Penicillium is a fairly common fungus and is one of the fungi responsible for moldy bread.

Fleming noticed that the penicillium prevented the Staphylococcus bacteria from growing and reasoned that the fungus must be releasing a chemical that was toxic to the bacteria.

Modern Medicine

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.