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Escherichia coli Serotype Identification (by Serotyping)

Published: August 9, 2026Updated: August 16, 2026

This test helps determine which specific serotype of *Escherichia coli* bacteria you may have, which can help guide treatment or infection management.

Quick summary

["Understanding your E. coli strain type can support tailored medical advice."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
20789-4
Short code
E coli Sertyp Islt
Synonyms
E coli Sertyp Islt
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Matters

Different strains of *E. coli* can cause varying infections, ranging from mild gastrointestinal issues to more severe urinary tract or bloodstream infections. Identifying the exact serotype helps healthcare providers choose the most effective treatment and understand potential risks.

What to Expect Before the Test

No special preparation is needed for this test. A healthcare provider will collect a sample, typically from urine, stool, or blood, depending on the suspected infection. The sample is then sent to a lab for analysis.

How the Test Works

The test uses serotyping methods to identify specific antigens (surface proteins) on the *E. coli* bacteria. This involves detecting antibodies or antigens that match known serotypes, often through techniques like agglutination or immunoassays.

What the Results Mean

Results will indicate which *E. coli* serotype is present. This information can help determine the type of infection, guide antibiotic selection, and inform further diagnostic steps if needed. Some serotypes are more commonly associated with certain infections or complications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

E. coli Serotype Test

Frequently asked questions

What are the possible causes or reasons for this test?
This test may be ordered if you have symptoms like diarrhea, urinary tract infections, or other signs of *E. coli* infection. It’s also used in research, food safety, or outbreaks to track and control the spread of specific strains.
How long will it take to get the results?
Results can take several days to a week, depending on the lab’s processing time. Your healthcare provider will contact you once the results are ready.
Are there any risks or side effects from this test?
There are generally no risks associated with this test. Minor discomfort or irritation at the sample collection site may occur, but it’s usually temporary.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy