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Antibiotic Resistance Profile for Methicillin-Resistant *Staphylococcus aureus* (MRSA) via Plate Method

Published: August 9, 2026Updated: August 17, 2026

This test checks how certain antibiotics affect *Staphylococcus aureus* bacteria, specifically those resistant to methicillin, which is often used to treat infections like skin or bloodstream infections.

Quick summary

["Helps determine which antibiotics may be most effective for treating MRSA-related infections."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
89371-9
Short code
MTB and RIF resistance Pnl Islt/Spm
Synonyms
MTB and RIF resistance Pnl Islt/Spm
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Critical range
0.5 N/A – —
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 involves growing a sample of your bacteria on a special culture plate with different antibiotics. The bacteria’s ability to grow (or not) in the presence of these antibiotics indicates resistance patterns. This helps identify which antibiotics are likely to work against your specific infection.

Why It’s Done

Your healthcare provider may order this test if you have symptoms of an infection caused by MRSA, such as persistent skin sores, fever, or signs of a systemic infection. It’s also used in settings like hospitals or nursing homes where MRSA is common.

How It’s Performed

A sample of your blood, wound, or other bodily fluid is collected and sent to a lab. The bacteria are grown on a plate with multiple antibiotics. Over several days, the lab observes which bacteria survive and grow, indicating resistance.

What to Expect Before the Test

No special preparation is needed unless instructed by your doctor. If you have a wound sample, it may be cleaned first to reduce contamination. If blood is drawn, follow standard precautions for venipuncture.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

MRSA Resistance Screening (Plate Culture)

Frequently asked questions

How long will results take?
Results typically take 2–5 business days, depending on lab processing times. Your doctor will contact you once they are ready to discuss the findings.
What does a positive result mean?
A positive result means your bacteria sample tested resistant to methicillin and may also show resistance to other antibiotics. This helps guide treatment choices to target the most effective medication for your infection.
Can I get this test at home?
No, this test requires a lab sample collected by a healthcare professional. Some at-home bacterial culture kits exist but are not FDA-cleared for MRSA resistance testing like this one.
  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 17, 2026. · Read our editorial policy