Methicillin-Resistant *Staphylococcus aureus* (MRSA) Resistance Mutation Profile by Serological Testing
This test helps assess whether certain genetic mutations in *Staphylococcus aureus* bacteria may contribute to resistance against methicillin, a common antibiotic. It’s part of broader efforts to monitor and manage infections caused by antibiotic-resistant bacteria.
["Understanding your bacterial resistance profile helps guide antibiotic treatment options."]
Key facts at a glance
- LOINC
- 89372-7
- Short code
- MTB rpoB RIF resist mut Islt/Spm Ql
- Synonyms
- MTB rpoB RIF resist mut Islt/Spm Ql
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- molgen
- 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 evaluates specific genetic mutations in *Staphylococcus aureus* that are linked to resistance to methicillin. It uses a serological method to detect the presence of these mutations in blood or other specimens where the bacteria may be present. The results help healthcare providers determine if antibiotic resistance is likely.
Why It Matters in Your Health
Identifying antibiotic resistance mutations is crucial because they can limit treatment options. If MRSA is detected with resistance mutations, your doctor may choose different antibiotics or adjust your treatment plan to ensure effective infection control.
Common Specimens and Testing Process
This test typically involves a blood sample (whole blood or serum/plasma) collected during a routine lab draw. The sample is analyzed in a lab to detect genetic markers associated with methicillin resistance. Results are usually reported as positive or negative for resistance mutations.
What to Expect Before the Test
No special preparation is needed for this test. You may have a small needle inserted to draw blood, which can cause a brief pinch or discomfort. If you’re concerned about blood draws, let your healthcare provider know.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
MRSA Resistance Screening
Frequently asked questions
If you have a suspected *Staphylococcus aureus* infection (such as skin infections, pneumonia, or bloodstream infections) and your doctor suspects MRSA, this test may be ordered to check for resistance mutations. Early identification helps prevent antibiotic failure and reduces the risk of spreading antibiotic-resistant bacteria.
How long does it take to get results from this test?
Can this test be used for routine check-ups, or is it only for infections?
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