Symptoms and Signs of E. coli Infection

Medical Author:
Medically Reviewed on 2/16/2022

Doctor's Notes on E. coli Infection

E. coli (also termed Escherichia coli) is a gram-negative rod-shaped bacterial species found worldwide; it has many subtypes that may cause a variety of diseases in humans. Usual signs and symptoms of E. coli infections are 

Depending on the bacterial subtype (determined by detection of certain surface antigens), other symptoms such as 

Severe infections can occur; signs and symptoms can include 

E. coli bacterial subtypes are the causes of E. coli infections. Some subtypes produce toxins that lead to more severe infections. Infections with E. coli usually begin in the gastrointestinal tract where E. coli abnormally proliferates and/or produces toxin that can cause severe symptoms.

What are treatments for E. coli infections?

The first treatments for these bacterial infections do not involve antibiotics; they include:

  • Rest
  • Fluids to avoid dehydration
  • Avoid anti-diarrheal medications

However, moderate to severe infections are often treated with antibiotics.  The antibiotics are chosen by your doctor who may know which E. coli subtype or strain is susceptible to various antibiotics so the treatment choice is more likely to help stop the infection (and/or toxin production) that you have. The following, for example, lists several antibiotics that may be used to treat an E. coli strain that produces carbapenemase:

However, some other E. coli strains may produce a Shiga-like toxin that antibiotics cause to produce increased toxin levels. Consequently, many doctors wait to prescribe or treat empirically E. coli infections until the subtype or strain is identified.

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Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.