Colistin Resistance by Minimum Concentration (MIC) Testing (Plasma)
This test measures the lowest concentration of colistin needed to inhibit bacterial growth, helping determine if bacteria are resistant to this antibiotic.
["Assists healthcare providers in guiding antibiotic treatment for infections caused by colistin-resistant bacteria."]
Key facts at a glance
- LOINC
- 98066-4
- Short code
- Colistin res mcr-(3-5) Islt/Spm Ql
- Synonyms
- Colistin res mcr-(3-5) 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
Why This Test Matters for You
Colistin is an antibiotic used to treat serious infections caused by certain bacteria, including those resistant to other drugs. This test helps doctors decide whether your bacteria are sensitive or resistant to colistin, which is critical for choosing the best treatment plan.
What to Expect Before the Test
No special preparation is needed. A blood sample will be collected from a vein in your arm by a healthcare professional. The blood is then processed to determine the colistin resistance level.
What the Test Results Mean
Results indicate the minimum concentration of colistin required to stop bacterial growth. If your bacteria are resistant, this means higher doses of colistin may not be effective, and alternative treatments may be needed. Your doctor will discuss the results with you.
Common Reasons for This Test
This test is often performed on patients with infections suspected to involve colistin-resistant bacteria, such as those with urinary tract infections, pneumonia, or bloodstream infections caused by Gram-negative bacteria.
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.
Colistin resistance is a growing concern in healthcare settings. Identifying resistance early helps prevent the spread of antibiotic-resistant bacteria and ensures appropriate treatment. It also supports infection control measures to limit further spread in hospitals and communities.
Short name
Colistin MIC Screening
Frequently asked questions
Will this test affect my antibiotic treatment plan?
How long will it take to get my test results?
Can I eat or drink 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