An Accident That Changed Medicine

(1) In 1928, the Scottish scientist Alexander Fleming returned to his laboratory in London after a summer holiday. Among the glass dishes he had left behind, in which he had been growing bacteria, he noticed something unusual. A mold had begun to grow on one of the dishes, and around it the bacteria had disappeared. Rather than throwing the dish away, Fleming decided to investigate.

(2) He found that the mold, a species of Penicillium, produced a substance that killed many kinds of harmful bacteria. He called it penicillin and published his findings the following year. Yet his discovery attracted little attention at first. Penicillin was difficult to produce in large amounts, and it was unstable: it lost its strength quickly. Fleming himself was unable to turn it into a practical medicine, and he eventually moved on to other research.

(3) About a decade later, a team at the University of Oxford, led by Howard Florey and Ernst Chain, took up the work again. They developed ways to purify penicillin and tested it, first on mice and then on human patients. The results were dramatic: infections that had often been fatal could now be cured. During the Second World War, companies in the United States developed methods of mass production, and by the end of the war penicillin was widely available to treat wounded soldiers.

(4) In 1945, Fleming, Florey and Chain shared the Nobel Prize. In his Nobel lecture, Fleming warned that bacteria could become resistant to penicillin if the drug was used carelessly, for example in doses too small to kill them. His warning proved accurate. Today, antibiotic resistance is considered one of the most serious threats to public health, and scientists continue to search for new ways to fight infection.

(1) In 1928, the Scottish scientist Alexander Fleming returned to his laboratory in London after a summer holiday. Among the glass dishes he had left behind, in which he had been growing bacteria, he noticed something unusual. A mold had begun to grow on one of the dishes, and around it the bacteria had disappeared. Rather than throwing the dish away, Fleming decided to investigate.

(2) He found that the mold, a species of Penicillium, produced a substance that killed many kinds of harmful bacteria. He called it penicillin and published his findings the following year. Yet his discovery attracted little attention at first. Penicillin was difficult to produce in large amounts, and it was unstable: it lost its strength quickly. Fleming himself was unable to turn it into a practical medicine, and he eventually moved on to other research.

(3) About a decade later, a team at the University of Oxford, led by Howard Florey and Ernst Chain, took up the work again. They developed ways to purify penicillin and tested it, first on mice and then on human patients. The results were dramatic: infections that had often been fatal could now be cured. During the Second World War, companies in the United States developed methods of mass production, and by the end of the war penicillin was widely available to treat wounded soldiers.

(4) In 1945, Fleming, Florey and Chain shared the Nobel Prize. In his Nobel lecture, Fleming warned that bacteria could become resistant to penicillin if the drug was used carelessly, for example in doses too small to kill them. His warning proved accurate. Today, antibiotic resistance is considered one of the most serious threats to public health, and scientists continue to search for new ways to fight infection.

(1) In 1928, the Scottish scientist Alexander Fleming returned to his laboratory in London after a summer holiday. Among the glass dishes he had left behind, in which he had been growing bacteria, he noticed something unusual. A mold had begun to grow on one of the dishes, and around it the bacteria had disappeared. Rather than throwing the dish away, Fleming decided to investigate.

(2) He found that the mold, a species of Penicillium, produced a substance that killed many kinds of harmful bacteria. He called it penicillin and published his findings the following year. Yet his discovery attracted little attention at first. Penicillin was difficult to produce in large amounts, and it was unstable: it lost its strength quickly. Fleming himself was unable to turn it into a practical medicine, and he eventually moved on to other research.

(3) About a decade later, a team at the University of Oxford, led by Howard Florey and Ernst Chain, took up the work again. They developed ways to purify penicillin and tested it, first on mice and then on human patients. The results were dramatic: infections that had often been fatal could now be cured. During the Second World War, companies in the United States developed methods of mass production, and by the end of the war penicillin was widely available to treat wounded soldiers.

(4) In 1945, Fleming, Florey and Chain shared the Nobel Prize. In his Nobel lecture, Fleming warned that bacteria could become resistant to penicillin if the drug was used carelessly, for example in doses too small to kill them. His warning proved accurate. Today, antibiotic resistance is considered one of the most serious threats to public health, and scientists continue to search for new ways to fight infection.