Penicillin
Year of Discovery: 1928
What Is It? The first commercially available antibiotic drug.
Who Discovered It? Alexander Fleming
Why Is This One of the 100 Greatest?
Penicillin has saved millions of lives—tens of thousands during the last years of World
War II alone. The first antibiotic to successfully fight bacterial infections and disease, penicillin was called a miracle cure for a dozen killer diseases rampant in the early twentieth
century.
Penicillin created a whole new arsenal of drugs in doctors’ toolkits to fight disease and
infection. It opened the door to entire new families and new generations of antibiotic drugs.
Penicillin started the vast industry of antibiotic drugs and ushered in a new era of medicine.
How Was It Discovered?
In 1928, 47-year-old Scottish born Alexander Fleming was named chief biochemist at
St. Mary’s Hospital in London and given a basement laboratory tucked in next to the boiler
room.
As the staff bacteriologist, he grew (or “cultured”) bacteria in small, round, glass
plates for hospital study and experiment. Using microscopic amounts of a bacterium (often
collected from a sick patient), he grew enough of each to determine why the patient was sick
and how best to fight the infection. Small dishes of deadly staphylococci, streptococci, and
pneumococci bacteria were lined and labeled across the one lab bench that stretched the
length of Fleming’s lab.
Molds were the one great hazard to Fleming’s lab operation. Fleming’s lab alternated
between being drafty and stuffy, depending on the weather and how hard the boiler worked
next door. His only ventilation was a pair of windows that opened at ground level to the
parklike gardens of the hospital. Afternoon breezes blew leaves, dust, and a great variety of
airborne molds through those windows. It seemed impossible to keep molds from drifting
into, and contaminating, most of the bacteria Fleming tried to grow.
On September 28, 1928, Fleming’s heart sank as he realized that a prized dish of pure
(and deadly) staphylococci bacteria had been ruined by a strange, green mold. The mold
must have floated into the dish sometime early the previous evening and had been multiplying since then. Greenish mold fuzz now covered half the dish.
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