Antibiotic Resistance

Antibiotic resistance occurs when bacteria change and can fight off the antibiotic medicines that typically kill them. Antibiotic resistance greatly limits treatment options and is a worldwide health problem. Some strains of bacteria are now superbugs, which means they don’t respond to several different antibiotics.

What is antibiotic resistance?

Antibiotic resistance occurs when bacteria change so that antibiotic medicines can’t kill them or stop their growth. As a result, bacterial infections become extremely difficult to treat.

Antibiotic resistance is a type of antimicrobial resistance. Fungi, parasites and viruses can also develop drug resistance.

Your body doesn’t develop antibiotic resistance — bacteria do. When antibiotic resistance happens, fewer antibiotics are effective against a particular bacterium. Other antibiotics often help, but it is important to have as many treatment options available as possible.


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Why is antibiotic resistance a problem?

When antibiotic resistance happens, we don’t know it has happened until we treat someone. The antibiotic that had previously been successful suddenly stops working or becomes less effective. It takes time to realize what is happening, and meanwhile, you get sicker. An infection that previously could be treated at home may require a hospital admission.

Close to 3 million Americans will develop a drug-resistant infection this year. More than 35,000 of them will die.

Why do healthcare providers use antibiotics?

You can find bacteria just about everywhere: in water, food and soil. Bacteria live on people’s skin (and animal fur) and inside bodies, too. Most bacteria don’t cause problems. In fact, some are beneficial. Healthy bacteria in the digestive system aid food digestion.

But some people need antibiotics to kill or stop the growth of bacteria that cause infections. Healthcare providers may prescribe antibiotics for:

  • Internal infections such as urinary tract infections
  • People who develop severe, potentially life-threatening bacterial infections like pneumonia or MRSA.
  • A bacterial infection that gets into the blood stream, which is then called sepsis.
  • Preventive purposes, such as lowering infection risk after a surgical procedure.

What causes antibiotic resistance?

These factors often contribute to antibiotic resistance:

  • Overuse of antibiotics: Taking antibiotics when they’re not needed or helpful contributes to antibiotic resistance. For instance, most cases of pharyngitis (sore throat) are viral. Antibiotics won’t help. Even bacterial ear infections often improve without antibiotics.
  • Misuse of antibiotics: Bacteria take advantage of any opportunity to multiply. If you forget to take a medicine for a day (or several days), stop treatment too soon, or use incorrect antibiotics (such as taking someone else’s medicine), bacteria start reproducing. As they multiply, they can change (mutate). Mutated bacteria become increasingly more resistant to a medicine.
  • Agricultural use: Bacteria in animals can also become antibiotic resistant. An estimated 80% of antibiotic use in the United States is for livestock.
  • Spontaneous resistance: Sometimes, the genetic makeup (DNA) of a bacterium changes or mutates on its own. The antibiotic doesn’t recognize this newly changed bacterium and can’t target it the way it should. Or the change helps the bacteria fight off the medicine’s effects.
  • Transmitted resistance: You can pass a contagious drug-resistant bacterial infection to someone else. That person now has an infection that won’t respond to an antibiotic. Again, we can usually find a treatment, but time has passed and the now resistant bacteria may be harder to treat.

What are superbugs?

Over the years, various strains of bacteria have adapted to the medicines that typically kill them. They can fight back against the drugs. Called superbugs, these bacteria continue multiplying and causing infections despite treatment with several different antibiotics. There’s a chance that no antibiotic will work.

Some bacterial infections with superbug status include:


What are the complications of antibiotic resistance?

Healthcare providers have limited treatment options when bacterial infections become drug resistant. The problem can lead to:

  • Increased risk of severe, extended illness and death.
  • Severe medication side effects.
  • Longer hospital stays.
  • More medical appointments.
  • Increased medical costs.

Who is at risk for harm from antibiotic resistance?

Anyone exposed to antibiotics is at risk for antibiotic resistance. Older people and those with weakened immune systems are more likely to develop serious bacterial infections that need antibiotic treatment. The combination puts them at higher risk for complications from antibiotic resistance.

You may be more likely to develop be impacted by antibiotic resistance if you:

How are antibiotic-resistant bacterial infections treated?

If an infection shows signs of antibiotic resistance, your healthcare provider may try a different drug. The new drug may have more severe side effects, and trying a different antibiotic also raises the risk of developing resistance to that drug.

Can you prevent antibiotic resistance?

These steps may lower your risk of developing antibiotic resistance:

  • Only take antibiotics prescribed for you. Don’t take someone else’s medicine.
  • Follow your healthcare provider’s advice to treat your symptoms without antibiotics. Don’t pressure your provider for an unnecessary prescription.
  • Set a reminder on your phone so you don’t miss a dose. If you do forget to take your medicine, ask your provider what to do.
  • Take all of the medicine as prescribed, even if you feel better. If you stop an antibiotic too soon, bacteria can start to grow again, and they may develop resistance.
  • Wash your hands regularly. Good hygiene lowers your risk of getting a bacterial infection.

A note from Cleveland Clinic

Bacteria that develop antibiotic resistance don’t respond to standard treatments. The result can be a bacterial infection that’s difficult to treat. Antibiotic resistance is a worldwide health problem. To help prevent drug resistance, healthcare providers prescribe antibiotics only when needed. Overuse and misuse of antibiotics are top contributors to antibiotic resistance. Be sure to follow your provider’s instructions. Take antibiotics only when necessary and exactly as prescribed.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 06/23/2021.

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