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Enteroaggregative Escherichia coli astA Gene DNA, Qualitative — Stool Nucleic Acid Amplification Test with Probe Detection

Published: August 9, 2026Updated: August 17, 2026

Detects astA gene DNA from enteroaggregative E. coli in a stool sample to help evaluate possible bacterial diarrhea.

Quick summary

["A positive result means the stool contains genetic material from an astA-carrying enteroaggregative E. coli strain."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
87319-0
Short code
EAEC astA gene Islt Ql NAA+probe
Synonyms
EAEC astA gene Islt Ql NAA+probe
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
10
Ref high
40
Critical range
— – 500 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
CPT
84484
SNOMED
302774002
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

What is this test?

This stool test uses nucleic acid amplification to detect DNA from the astA gene of enteroaggregative Escherichia coli, or EAEC. The astA gene can be associated with an enterotoxin produced by this bacterium.

Why might I need this test?

The test may be used when someone has watery or prolonged diarrhea, especially during a suspected outbreak, after international travel, or when a bacterial cause of gastrointestinal symptoms is being investigated.

How is the test performed?

A stool sample is collected and tested in a laboratory. The laboratory amplifies and identifies selected DNA sequences, including the astA gene, using probe-based detection.

How do I prepare for the test?

No fasting is usually required. Collect the stool sample in the container provided and follow the laboratory's collection and transport instructions. Wash your hands before and after handling the sample, and avoid contaminating it with urine or toilet water.

Reference range

Adult: 10-40 U/LN/A

Specimen: serum

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

EAEC astA Gene Test

Frequently asked questions

Does a positive result mean I definitely have an E. coli infection?
Not always. The result shows that the gene was detected, and your healthcare professional will interpret it alongside your symptoms, exposure history, and other laboratory findings.
Can this test tell me if the bacteria are producing toxin?
No. It detects the astA gene, which can be associated with toxin production, but it does not directly measure toxin activity.
What if the test result is negative but my diarrhea continues?
Other causes of diarrhea, including infections not detected by this test, may still be possible. Contact your healthcare professional for further evaluation.
  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 17, 2026. · Read our editorial policy