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Escherichia coli (E. coli) antibody screening test (serum/plasma)

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

This test checks for antibodies in your blood that may indicate past or current exposure to *Escherichia coli* bacteria, a type of gut bacteria that sometimes causes infections.

Quick summary

["This test helps identify immune responses to E. coli, which can inform diagnosis or monitoring of infections or immune responses."]

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

Key facts at a glance

LOINC
51939-7
Short code
E coli SXT2 Stl Ql IA
Synonyms
E coli SXT2 Stl Ql IA
Category
chemistry
Sample
stool
Container
Clean container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
Specimen volume
5 g
Stability
Refrigerated: 24h, Frozen: 7d
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms like fever, stomach pain, diarrhea, or if you’ve been exposed to E. coli. It may also be used to assess immune responses in certain conditions, such as autoimmune disorders or after infections.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from your arm. The test looks for antibodies (proteins your immune system makes) in your serum or plasma.

What the Test Results Mean

A positive result means your body has detected E. coli antibodies, suggesting past exposure or an immune response. A negative result means no detectable antibodies were found in this sample. Results alone don’t confirm an active infection—your provider will consider symptoms and other tests.

Common Reasons for Testing

This test is often used for research, monitoring immune responses, or evaluating conditions where E. coli exposure or immune reactions are suspected, though it’s not typically used for diagnosing active infections like urinary tract infections (UTIs).

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

E. coli Antibody Screen

Frequently asked questions

What does a positive result mean?
A positive result indicates your immune system has likely encountered E. coli before, meaning your body has produced antibodies to fight it. This could be from food poisoning, urinary tract infections, or other exposures. It doesn’t confirm a current infection but may help track immune responses in certain medical situations.
Can this test detect a current E. coli infection?
No, this test primarily detects past exposure or immune responses, not active infections. For diagnosing current infections (e.g., UTIs), other tests like urine cultures or specific antibody tests (e.g., anti-O157 antibodies) are used instead.
How often should I get this test?
This test is usually not routine unless your healthcare provider specifically orders it for research, monitoring, or suspected immune-related conditions. Follow their guidance for frequency.
  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