The Discovery of Antibiotics

Learn how antibiotics were discovered.

In August 1928, before leaving for vacation, Scottish microbiologist Alexander Fleming stacked his cultures of infection-causing Staphylococcus bacteria on a laboratory bench. When he returned to work a few weeks later, Fleming noticed that one culture had been contaminated with Penicillium fungus, and that the colony of Staphylococcus surrounding it had been destroyed! Fleming named the bacteria-killing substance penicillin, and he suggested that it could be used to treat bacterial infections in humans.

When Fleming published his discovery in 1929, his article had little immediate impact. Subsequent experiments struggled to isolate the antibiotic agent (i.e., the compound that actually killed bacteria) from the fungus. As a result, Fleming eventually concluded that penicillin couldn’t be practically applied to treat bacterial infections and abandoned his antibiotics research.

Mass producing of antibiotics

Searching for new drugs to treat wounded soldiers, the American and British governments intensified their search for antibiotics after the start of World War II; however, the challenge of mass-producing antibiotics remained. In March 1942, half of the total supply of penicillin owned by pharmaceutical giant Merck was used to treat a single infected patient.

Also in 1942, Russian biologists Georgy Gause and Maria Brazhnikova noticed that the Bacillus brevis bacterium killed the pathogenic bacterium Staphylococcus aureus. In contrast to Fleming’s efforts with penicillin, they successfully isolated the antibiotic compound from Bacillus brevis and named it Gramicidin Soviet. Within a year, this antibiotic was distributed to Soviet military hospitals.

Meanwhile, American scientists were scouring various food markets for rotten groceries and finally found a moldy cantaloupe in Illinois with a high concentration of penicillin. This mundane discovery allowed the United States to produce 2 million doses of penicillin in time for the Allied invasion of Normandy in 1944, thus saving thousands of wounded soldiers’ lives.

Gause continued his research into Gramicidin Soviet after World War II but failed to elucidate its chemical structure. Taking the torch from Gause, English biochemist Richard Synge studied Gramicidin Soviet and a wide array of other antibiotics produced by Bacillus brevis. A few years after World War II ended, he demonstrated that they represent short amino acid sequences (i.e., mini-proteins) called peptides. Gause received the Stalin Prize in 1946, and Synge won the Nobel Prize in 1952. The former award proved more valuable as it protected Gause from execution during the period of Lysenkoism, the Soviet campaign against “bourgeois” geneticists that intensified in the postwar era.

The challenge of drug resistant pathogenic bacteria

The mass-production of antibiotics initiated an evolutionary arms race between pharmaceutical companies and pathogenic bacteria. The former worked to develop new antibiotic drugs, while the latter acquired resistance against these drugs. Although modern medicine won every battle for six decades, the last ten years have witnessed an alarming rise in antibiotic-resistant bacterial infections that can’t be treated even by the most powerful antibiotics. In particular, the Staphylococcus aureus bacterium that Gause had studied in 1942 mutated into a resistant strain known as Methicillin-resistant Staphylococcus aureus (MRSA). MRSA is now the leading cause of death from infections in hospitals; its death rate has even passed that of AIDS in the United States.

With the rise of MRSA at hand, developing new antibiotics represents a central challenge to modern medicine. A difficult problem in antibiotics research is that of sequencing newly discovered antibiotics, or determining the order of amino acids making up the antibiotic peptide.

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