Biology & Society

Should Antibiotic Use Be Restricted?

Natural selection and evolution aren't just about fossils and finches. Many disease-causing bacteria are evolving resistance to antibiotics—drugs intended to kill them or interfere with their growth.

During your lifetime, antibiotics have always been available and effective. So it is probably hard for you to imagine what life was like before antibiotics were discovered. It wasn't pleasant. During the 1930s, it was not unusual for half of all children in a family to die from bacterial infections that are considered trivial today.

When antibiotics were developed, they rapidly became one of medicine's greatest weapons. Antibiotics saved thousands of lives during World War II by controlling bacterial infections among wounded soldiers. Soon, many bacterial diseases, such as pneumonia, posed much less of a threat. That's why antibiotics were called “magic bullets” and “wonder drugs.” But the magic is fading as bacteria evolve.

Bacterial populations have always contained a few individuals with mutations that enabled them to destroy, inactivate, or eliminate antibiotics. But those individuals didn't have higher fitness, so those mutant alleles didn't become common.

Then, doctors began prescribing antibiotics widely, and farmers started feeding antibiotics to farm animals to prevent infections. As a result, antibiotics have become a regular part of the environment for bacteria.

In this new environment, individuals with resistance alleles have higher fitness, so the resistance alleles increase in frequency. Also, resistance alleles can be transferred from one bacterial species to another on plasmids. Thus, disease-causing bacteria can pick up resistance from harmless strains. Many bacteria, including those that cause tuberculosis and certain forms of staph infections, are evolving resistance to not just one antibiotic, but to almost all medicines known. Many doctors are terrified. They fear the loss of one of the vital weapons against bacterial disease. Given this problem, should government agencies restrict antibiotic use?

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