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Antibiotic Resistance

What is antibiotic resistance?

Antibiotics are medicines used to kill germs called bacteria. Over time, certain groups of these germs may adapt to these medicines. They may change in such a way that antibiotics can′t kill them. The term for this is antibiotic resistance.

Bacteria are very small organisms. They can enter your body. Some of them are harmless and may be helpful. But some of these germs can be harmful. When these multiply inside your body, they can cause disease.

Before antibiotics, people often got very sick from bacterial infections. With these medicines, it is now easy to treat many of these infections.

Antibiotic resistance is a serious concern throughout the world. It can lead to illnesses that are very hard to treat. Standard antibiotics for treating a disease may no longer work in these cases. Other medicines may also not help. As a result, resistance to antibiotics is becoming more common.

What causes antibiotic resistance?

Antibiotic resistance can happen when bacteria are treated with an antibiotic. The medicine kills most of these germs. But a small group may survive. This might happen in a number of ways. The germs may:

  • Develop an ability to stop the medicine’s effect
  • Develop an ability to pump the medicine out of the cell
  • Change (mutate) so that the medicine no longer works


When you use an antibiotic, there is a risk that some of the bacteria will turn resistant. Using these medicines when they are not needed is a major reason why that is becoming more common. So you should use these medicines only when needed.

Antibiotic resistance is often linked to a specific germ and antibiotic. For example, Staphylococcus aureus (or “staph”) is a type of bacteria that can cause illness. Methicillin-resistant S. aureus (MRSA) is a specific strain of staph bacteria. MRSA no longer responds to the antibiotic methicillin (and closely related medicines). As a result, it can cause many infections that are hard to treat.

Who is at risk for antibiotic resistance?

The more people use antibiotics, the more likely that resistance will happen. Sometimes people use antibiotics when they don’t really need them. For example, antibiotics don’t work against viruses. Like bacteria, viruses are germs that can invade your body and cause infection. A cold or the flu is a type of virus. Taking an antibiotic in these cases does not treat the disease. It can actually raise the risk for antibiotic resistance.

Not taking all of an antibiotic also raises the risk. If you stop taking it too early, you might not kill all the bacteria. The remaining germs may become resistant.

How antibiotic-resistant infections spread

Resistant bacteria spread in the same ways as nonresistant bacteria. Someone infected with the bacteria (or just carrying it on the skin) might touch an object. When you touch the same object, the germs can enter your body. Often this is through a cut on your skin. Some infections can spread in the air when a person sneezes or coughs. Others can spread through sharing food with an infected person. Sexual contact is one more way these infections spread.

You can help prevent the spread of all bacterial infections by:

  • Always washing hands thoroughly with soap and water
  • Not sharing food or beverages with others
  • Practicing safe sex
  • Using tissues to cover your mouth when coughing or sneezing
  • Not touching other people's wounds
  • Not sharing personal items such as razors, towels, or brushes

Plain soap is best for washing hands and shared surfaces. Soaps with antibacterial ingredients do not help stop the spread of infection in a home setting. They may also contribute to resistance.

What are the symptoms of an antibiotic-resistant infection?

Infections from antibiotic-resistant bacteria can affect almost every part of the body. They can cause many symptoms. But symptoms alone can’t tell you whether an infection is from antibiotic-resistant bacteria.

How are antibiotic-resistant infections diagnosed?

Your healthcare provider may take a sample of your infected tissue and send it to a lab. There, the type of infection can be figured out. Tests can also show which antibiotics will kill the germs. You may have an antibiotic-resistant infection if you don’t get better after treatment with standard antibiotics.

How are antibiotic-resistant infections treated?

Treatment for these infections can vary. Your healthcare provider may have another antibiotic that can fight the infection. But it might have certain drawbacks. It may have more side effects or a risk of promoting more resistance. In a few cases, your healthcare provider might not have another option. In this case, you will get supportive care to help you feel better and get stronger.

What can I do to prevent antibiotic resistance?

The best way to prevent antibiotic resistance is to use antibiotics properly. Take take them only when needed. Here are some of the ways you can help:

  • Don’t take an antibiotic for a virus such as from a cold or the flu
  • Don’t save an antibiotic for the next time you get sick.
  • Take antibiotics exactly as prescribed. Don’t skip doses. Complete your full course of treatment even if you are feeling better.
  • Never take an antibiotic prescribed for someone else.

Healthcare providers can also help by:

  • Only prescribing antibiotics that are needed
  • Targeting the medicine as soon as possible to the specific bacteria involved
  • Prescribing medicines for only as long as needed

Other public health measures can also help lower resistance. That includes cutting the use of antibiotics in livestock.

Healthcare providers also need to take steps to stop the spread of these infections. These bacteria are very common in healthcare settings. They should always maintain good hygiene. They should also always use techniques that control infection.

Key points about antibiotic resistance

  • Standard antibiotics can't kill bacteria that have become resistant. Many of these germs have spread throughout the world.
  • These bacteria can cause infections. They can be very hard to treat.
  • If you have an antibiotic-resistant infection, healthcare provider may or may not have other treatment options.
  • Taking unneeded antibiotics promotes the growth of resistant bacteria.
  • Practice good hygiene. It helps prevent the spread of infections that are resistant to antibiotics.

Next steps


  • Before your visit, write down questions you want answered.
  • Ask if your condition can be treated in other ways.
Online Medical Reviewer: Horowitz, Diane, MD
Date Last Reviewed: 4/1/2018
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