Mycobacterial Culture and Sensitivity for Ethambutol and Rifampin Resistance (Slow-Growing Mycobacteria)
This test checks if slow-growing mycobacteria (like tuberculosis) are resistant to two key antibiotics—ethambutol and rifampin—used to treat infections. It helps doctors decide if your treatment needs adjustment.
["This test helps determine if your slow-growing bacteria are resistant to common tuberculosis drugs, guiding treatment decisions."]
Key facts at a glance
- LOINC
- 55154-9
- Short code
- Ethambutol+rifAMPin Islt SlowMyco
- Synonyms
- Ethambutol+rifAMPin Islt SlowMyco
- 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
- 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
Why This Test Is Done
Your doctor may order this test if you have symptoms of tuberculosis (like cough, fever, or weight loss) and slow-growing mycobacteria are suspected. It’s particularly useful when standard antibiotics aren’t working or if you’ve been exposed to drug-resistant strains.
What to Expect Before the Test
No special preparation is needed. A sample of your slow-growing mycobacteria culture (grown in a lab) is tested for resistance. Results help tailor your treatment plan.
How the Test Works
A lab culture grows the bacteria over time, then tests how they respond to ethambutol and rifampin. Resistance means the bacteria survive these drugs, requiring alternative treatments.
What the Results Mean
If the bacteria are resistant to both drugs, your doctor may switch to other antibiotics or adjust your regimen. If they’re sensitive, your current treatment may continue.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Resistance to Ethambutol and Rifampin
Short name
Ethambutol/Rifampin Resistance Screening (Slow Myco Culture)
Frequently asked questions
If your slow-growing mycobacteria test positive for resistance to these drugs, it may mean your infection is harder to treat. This can lead to longer illness, higher risk of complications, or the need for more aggressive therapies.
How long will I need to wait for results?
What if my test shows resistance to both drugs?
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