Escherichia coli (E. coli) bacterial culture with rapid identification and antibiotic susceptibility testing (rapid ID/AST)
This test checks for the presence of *Escherichia coli* bacteria in your blood and determines which antibiotics might help treat an infection caused by them.
["Identifies blood infections and guides antibiotic choices quickly."]
Key facts at a glance
- LOINC
- 111819-9
- Short code
- E coli O157H7 Ag Stl Ql IA.rapid
- Synonyms
- E coli O157H7 Ag Stl Ql IA.rapid
- Category
- chemistry
- Sample
- stool
- Container
- Clean container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ia-rapid
- Specimen volume
- 5 g
- Stability
- Refrigerated: 24h, Frozen: 7d
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your healthcare provider may order this test if you have symptoms like fever, chills, or unexplained pain, especially if you’ve recently had surgery, a catheter, or a break in your skin. It’s also used when you’re at higher risk for blood infections, such as those with weakened immune systems or certain medical devices in place.
What to Expect During the Test
A small sample of your blood is drawn from a vein, usually in your arm. The sample is placed in a special container and sent to the lab. The lab will grow the bacteria and test them for antibiotic resistance within hours to days, depending on the rapid methods used.
What the Results Mean
If *E. coli* is found, it confirms a blood infection. The antibiotic susceptibility results help your doctor choose the most effective treatment. Without *E. coli*, no infection is detected in this sample.
Common Causes and Risks
Blood infections by *E. coli* often occur due to a break in the skin, urinary tract infections spreading, or medical devices like catheters. Risk factors include diabetes, chemotherapy, or recent surgeries.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
E. coli Blood Culture
Frequently asked questions
How quickly results are available depends on the lab’s rapid testing methods. Early identification allows for faster treatment, which can reduce complications like sepsis. If *E. coli* is resistant to common antibiotics, alternative treatments may be needed.
What happens if the test is positive for *E. coli*? Your doctor will review the antibiotic susceptibility results to pick the best medication for you.
Can I eat or drink before this test? You may eat and drink normally unless instructed otherwise by your healthcare provider, as this test only requires a blood sample.
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