Colistin Resistance Microbial Culture and Susceptibility Test (Serum/Plasma)
This test checks whether bacteria in your body may be resistant to colistin, a type of antibiotic used to treat serious infections caused by certain bacteria.
["Helps determine if your infection could be harder to treat with standard antibiotics."]
Key facts at a glance
- LOINC
- 86221-9
- Short code
- Colistin res mcr-1 Islt/Spm Ql
- Synonyms
- Colistin res mcr-1 Islt/Spm Ql
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- molgen
- CPT
- 85610
- SNOMED
- 396252006
- 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
This test involves growing bacteria from a sample (likely blood or other body fluid) and testing their response to colistin. Resistance means the bacteria survive exposure to colistin, which could indicate a need for alternative treatments.
Why It’s Ordered
Your healthcare provider may order this test if you have a severe infection with bacteria that are known to be resistant to colistin or if you’ve been exposed to colistin-resistant bacteria.
What to Expect
The test involves taking a sample (e.g., blood or urine) and sending it to a lab. Results are typically available within 2–5 business days. You may not need to prepare for this test.
Possible Outcomes
If the test shows resistance, it means the bacteria in your sample may not respond to colistin. This can guide treatment choices, such as switching to a different antibiotic.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Colistin resistance is critical because it limits treatment options for infections caused by multidrug-resistant (MDR) bacteria. Early identification helps prevent spread and ensures appropriate antibiotic use to preserve effectiveness.
Short name
Colistin Resistance Screening
Frequently asked questions
What does a positive result mean?
How long does it take to get results?
Can I take antibiotics before this test?
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