Antibiotics and the Foundations of Modern Medicine

The Scottish bacteriologist Alexander Fleming made one of the most celebrated accidental discoveries in the history of science in September 1928, while working at St Mary's Hospital in London. Returning from a holiday, Fleming noticed that a petri dish of Staphylococcus bacteria he had left uncovered had become contaminated with a mold, later identified as Penicillium notatum, and that the bacterial colonies immediately surrounding the mold had been destroyed. Fleming correctly inferred that the mold was producing a substance capable of killing bacteria, which he named penicillin, and published his observations in 1929. However, Fleming lacked the chemical expertise to isolate and stabilize the active compound in a form suitable for treating patients, and his discovery attracted comparatively little attention for the following decade. It nonetheless represented the first identification of what would become the most important class of antibacterial drugs in medical history, establishing the basic observation on which the entire field of antibiotic medicine would later be built.