E. coli O157:H7 Detection by Probe-Based Molecular Assay (Stool)
This test checks for the presence of *Escherichia coli* (E. coli) strain O157:H7 in your stool. This specific strain is linked to severe foodborne illnesses, including bloody diarrhea and kidney failure in some cases.
["This test helps identify if you may have been exposed to a harmful bacterial strain that requires medical attention."]
Key facts at a glance
- LOINC
- 75678-3
- Short code
- Deprecated E coli oppA Bld Pos Ql Prb Mag
- Synonyms
- Deprecated E coli oppA Bld Pos Ql Prb Mag
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- probe-mag-capture
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Your healthcare provider may recommend this test to find out if you have a certain illness or to check how well a part of your body is working. Knowing the reason for the test helps you prepare and gives your care team important information to choose the right treatment plan for your situation.
Your healthcare provider may order this test if you experience symptoms like severe diarrhea (with blood), abdominal pain, or vomiting after eating contaminated food. It’s also used in outbreaks or if you’ve had recent contact with someone who has been infected.
Before the test, you will receive clear instructions from your clinic about any foods, drinks, or medicines to avoid. You may need to fill out a short health history form, and a nurse will explain the steps so you feel comfortable and know exactly what to do on the day of your appointment.
No special preparation is needed, but you may be asked to collect a stool sample in a clean container. If you’re at a lab, staff will guide you on how to do this safely.
During the test, a trained technician will collect the needed sample or perform the measurement using safe, standard equipment. The process is usually quick and causes only mild discomfort, and you will be watched by staff to make sure you are safe and relaxed the whole time.
A small sample of your stool is tested using a molecular probe to detect genetic material from *E. coli* O157:H7. This method is highly sensitive and can detect even trace amounts of the bacteria.
After the test, your results will be reviewed by a doctor who will explain what they mean for your health. If the findings are normal, you may need no further action; if they are not, your provider will discuss follow-up tests or treatments so you know the next steps to take.
A positive result means the bacteria is present and may require antibiotics, fluids, or medical monitoring. A negative result doesn’t rule out infection—other strains of E. coli or other causes of symptoms could be present. Follow your doctor’s advice for further testing or treatment.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Understanding the Implications
Short name
E. coli O157:H7 Stool Test
Frequently asked questions
This test is critical for diagnosing *E. coli* O157:H7 infections, which can cause serious illness, especially in children, the elderly, or those with weakened immune systems. Early detection helps prevent complications like hemolytic uremic syndrome (HUS).
If positive, you’ll likely need to see a doctor for treatment, which may include antibiotics (though some strains are resistant), intravenous fluids, or monitoring for complications. Avoid raw foods, especially those like spinach or lettuce, until your infection clears.
No, this test is typically done in a clinical or lab setting. You’ll need to provide a stool sample under sterile conditions, often with instructions from healthcare staff.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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