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Bacterial Culture with Erythromycin Resistance Testing (from Stool Sample)

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

This test checks if bacteria in your stool are resistant to the antibiotic erythromycin, which could affect how your doctor treats potential infections.

Quick summary

["Erythromycin resistance testing helps guide antibiotic choices for gastrointestinal infections."]

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

Key facts at a glance

LOINC
25224-7
Short code
Erythromycin Islt Slgr Mcbct AB 15.0
Synonyms
Erythromycin Islt Slgr Mcbct AB 15.0
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
method-for-slow-growing-mycobacteria-antibiotic-concentration-at-ug-ml
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 This Test Measures

The test identifies whether bacteria in your stool sample grow in the presence of erythromycin. If bacteria survive, it suggests resistance. This is done using a culture method that isolates and grows bacteria, then tests their response to erythromycin.

Why It’s Done

Your doctor may order this test if you have symptoms like diarrhea, abdominal pain, or fever that could indicate a bacterial infection, especially if antibiotics like erythromycin are being considered. It helps ensure the right antibiotic is chosen to treat the infection effectively.

Sample Collection and Process

A stool sample is collected (often via a stool kit provided by your healthcare provider). The sample is sent to a lab where bacteria are cultured on special growth media. Erythromycin is added to some plates to see if bacteria grow despite its presence, indicating resistance.

When Results Are Needed

Results typically take 3–5 days to grow bacteria and confirm resistance. Your doctor will discuss the findings with you, including whether further testing or treatment adjustments are needed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Stool Culture for Erythromycin Resistance

Frequently asked questions

How long will I have to wait for results?
Results are usually ready within 3–5 business days, depending on lab processing times. Your doctor will contact you once they are available.
What does a positive result mean?
A positive result means bacteria in your stool are resistant to erythromycin. This doesn’t necessarily mean you have an infection, but it helps guide treatment choices if one exists. Your doctor will assess symptoms and other test results to determine the next steps.
Can I take antibiotics before the test?
It’s best to avoid antibiotics unless prescribed by your doctor before the test, as they may affect the accuracy of the culture results. Follow your healthcare provider’s instructions for timing.
  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