How Antibiotics Work: Past, Present, and Future

September 28th is the anniversary of the discovery of antibiotics. How do antibiotics work, and how have they recolutionized medicine? Plus, why are people becoming resistant to certain antibiotics?

Sabrina Stierwalt, PhD
5-minute read
Episode #209

How Do Antibiotics Work?

In March 1942, Anne Miller became the first civilian whose life was saved by penicillin. She had contracted blood poisoning after suffering a miscarriage in a hospital in New Haven, CT.

Penicillin works by effectively causing bacterial cell walls to burst. More specifically, peptidoglycan, a lattice-like structure made from amino sugars and peptides that surrounds the plasma membrane in bacteria acts to fortify its cell walls and keep fluid out. To multiply, small holes need to open up in the cell walls which are quickly filled in with new peptidoglycans but penicillin prevents this process, known as transpeptidation. Instead, water enters the cell, and the cell explodes.

Penicillin has proven successful against many bacterial infections including chlamydia, strep throat, listeria, staph infections, a type of gangrene, gastritis, lyme disease, typhoid, pneumonia, gonorrhea … the list goes on.

Antibiotic Resistance

According to the CDC, each year at least 2 million people are infected with bacteria that are antibiotic resistant.

Unfortunately, this story does not yet have a happy ending. In 1945, when Fleming was awarded the Nobel Prize in Physiology or Medicine along with Florey and Chain, he warned that the overuse of antibiotics could lead to bacterial resistance. According to the CDC, each year at least 2 million people are infected with bacteria that are antibiotic resistant and 23,000 people die annually from bacterial infections.

The evolution of antibiotic-resistant bacteria, so-called super bugs, will occur naturally over time, but, through misuse of antibiotics, we are accelerating the process before we can develop new tools in the bacterial fight. Without antibiotics, we could return to an era when a small scratch from a rose could be fatal. A world without antibiotics also threatens our ability to conduct any procedures that require that we make ourselves vulnerable to infection, including organ transplants, cancer chemotherapy, diabetes management, and any major surgery, like C-sections. Drug resistance is already proving a challenge in fights against TB, HIV, gonorrhea, and malaria.  

The World Health Assembly has adopted a global action plan to address antimicrobial resistance and officials met to discuss the topic this month at the United Nations General Assembly. The World Health Organization further provides a list of recommendations for how you and I can play a role in the fight against super bugs as members of the general public:

  • Prevent infections by regularly washing hands, practice good food hygiene, avoid close contact with sick people, and keep vaccinations up to date
  • Only use antibiotics when prescribed by a certified health professional
  • Always take the full prescription and never use left over antibiotics
  • Never share antibiotics with others

Until next time, this is Sabrina Stierwalt with Ask Science’s Quick and Dirty Tips for helping you make sense of science. You can become a fan of Ask Science on Facebook or follow me on Twitter, where I’m @QDTeinstein. If you have a question that you’d like to see on a future episode, send me an email at everydayeinstein@quickanddirtytips.com

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About the Author

Sabrina Stierwalt, PhD

Dr Sabrina Stierwalt earned a Ph.D. in Astronomy & Astrophysics from Cornell University and is now a Professor of Physics at Occidental College.