Extended spectrum beta-lactamases (ESBLs) are enzymes made by bacteria. ESBL infections make it hard for some medicines to work. This can lead to serious health problems. Sometimes it can be fatal.

The Intestines

The bacteria can travel to the intestines, causing a serious infection.

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Certain bacteria cause the infections. Some people carry them without being sick. but can spread it to others. In the U.S., they are spread by touching people. In other countries they may spread through food or water that has them.

Risk Factors

This problem is more common in Asia and Northern Africa. Travel to these areas raises the risk. However, it can happen anywhere. It is also more common in older people.

Other things that raise the risk are:

  • Being in a hospital or nursing home for a long time
  • Having a history of antibiotic use
  • Having health problems such as:
  • Being on a ventilator—to help with breathing
  • Using a tube to drain urine from the bladder


Symptoms depend on the where the ESBL infection is. They may be:

  • Fever or chills
  • Belly pain
  • Pain and burning when passing urine
  • Redness or warmth near a wound
  • Diarrhea
  • Loss of hunger
  • Nausea and vomiting
  • Breathing problems


The doctor will ask about your symptoms and health history. A physical exam may be done. Tests will be done to check for bacteria. They may be:

  • Urine tests
  • Blood tests
  • Stool tests
  • Swabs for cultures


Only certain antibiotics can treat ESBL infections.


Health care staff can lower the risk of infection by:

  • Washing hands before and after touching people and surfaces
  • Wearing a gown or gloves

Others can lower their risk by:

  • Washing hands often
  • Using antibiotics as advised

Centers for Disease Control and Prevention

National Institute of Allergy and Infectious Diseases


Alberta Health Services

Public Health Agency of Canada


Antibiotic/antimicrobial resistance. Centers for Disease Control and Prevention website. Available at: Accessed February 5, 2021.

ESBL-producing enterobacteriaceae in healthcare settings. Centers for Disease Control and Prevention website. Available at: Accessed February 5, 2021.

Extended spectrum beta-lactamases (ESBLs). EBSCO DynaMed website. Available at: Accessed February 5, 2021.

Lee JH. Perspectives towards antibiotic resistance: from molecules to population. J Microbiol. 2019;57(3):181-184.

Last reviewed September 2020 by David L. Horn, MD, FACP  Last Updated: 2/5/2021