Antibiotics Work

The modern scientific journey of antibiotics began in the early 20th century with the microbiologist Paul Ehrlich. He searched for potential medicines that could target microbes without harming human cells. In 1910, after testing hundreds of compounds, he achieved a breakthrough with salvarsan — the first effective treatment for syphilis and the first synthetic antibiotic.2

In another article, we explain in more detail how different antibiotics work.
Another milestone came in 1928 when Alexander Fleming observed fungal mold on a contaminated Petri dish that killed bacteria. He had discovered penicillin.

Unfortunately, scaling up its production took years.3 In the late 1930s and early 1940s, the U.S. War Production Board coordinated efforts to improve fermentation, organize trials, foster collaboration, and lift patent restrictions — which sped up development. By 1945, they had succeeded, making penicillin widely available.4

Another breakthrough was also achieved during this time: scientists discovered the potential of actinomycetes, a group of soil-dwelling bacteria, which eventually became the source of many antibiotics like streptomycin, tetracyclines, and erythromycin.5

The period between the 1940s and 1960s is known as “the golden age of antibiotics”, as intense research into natural and synthetic compounds led to the rapid discovery of many new antibiotics.
As the timeline shows, almost two-thirds of all antibiotic drug classes were developed and introduced during the golden age of antibiotics.

By the 1970s, however, the antibiotic pipeline slowed down. Pharmaceutical companies shifted focus to chronic disease treatments, which were more profitable, especially as bacterial resistance to antibiotics grew. In addition, efforts to spot new antibiotics by screening organisms for antibiotic activity often led to reidentifying the same compounds already discovered by others.2