TECHNOLOGY

The Mould That Killed Bacteria

1928 to 1945 CE

Phanerozoic · Cenozoic · Quaternary · Holocene · Meghalayan

A culture plate left uncovered showed bacteria dissolving in a ring around a spot of mould. Turning that observation into a medicine took another decade, a second laboratory and a wartime industrial effort; by 1945 penicillin was being made by the ton, and infections that had killed reliably stopped killing.

Why it matters

Life expectancy jumped, and evolution answered before the war was over: resistant bacteria were reported while the drug was still new. It is the fastest large-scale natural selection anyone has ever watched, it is still running, and every course of antibiotics anybody takes is a round of it.

Dating & uncertainty

The observation dates from 1928 and the paper from 1929. Turning it into a medicine took another decade and a wartime industrial effort; resistant bacteria were reported before the war was over.

Sources

1. Fleming (2001), Bulletin of the World Health Organization · On the antibacterial action of cultures of a penicillium
2. Hutchings, Truman & Wilkinson (2019), Current Opinion in Microbiology · Antibiotics: past, present and future

Earth history as one day

23:59:59.99811.9 ms before midnight

if Earth’s 4.54 billion years were compressed into a single day