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Beta-lactamase gene sequencing (qualitative, confirmatory)

Published: August 9, 2026Updated: August 16, 2026

This test checks whether certain bacteria produce beta-lactamase enzymes that make them resistant to common antibiotics like penicillin and cephalosporins. It helps doctors determine the best treatment for infections caused by these resistant bacteria.

Quick summary

["Helps identify antibiotic-resistant bacteria to guide infection treatment."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
85839-9
Short code
ESBL blaTEM gene Islt/Spm Ql
Synonyms
ESBL blaTEM gene 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

Why This Test Matters for Your Health

Beta-lactamase enzymes can make antibiotics less effective, leading to harder-to-treat infections. This test confirms if bacteria in your sample carry genes that produce these enzymes, helping doctors choose the right antibiotics for your condition.

How the Test Works

A small sample of your blood, urine, or other bodily fluid is tested for specific genetic markers linked to beta-lactamase production. The test uses advanced molecular techniques to detect these genes, ensuring accurate identification of resistant bacteria.

Common Uses and When You Might Need It

This test is typically ordered if you have an infection that doesn’t improve with standard antibiotics, or if you’re at higher risk for antibiotic-resistant infections (e.g., hospital-acquired infections, certain chronic illnesses). It’s also used in research or monitoring to track antibiotic resistance trends.

What to Expect Before the Test

No special preparation is usually needed. Your healthcare provider will collect a sample (e.g., blood, urine, or swab) during a routine visit. The sample may be sent to a lab for processing, and results are typically ready within a few days to a week, depending on the lab.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Positive results indicate bacteria resistant to beta-lactam antibiotics, which may require alternative treatments like carbapenems, colistin, or other non-beta-lactam antibiotics. Early identification helps prevent unnecessary antibiotic use, reduces treatment failures, and lowers the risk of spreading antibiotic-resistant infections in healthcare settings.

Short name

ESBL Gene Confirmation

Frequently asked questions

What does a positive result mean?
A positive result means your sample contains bacteria that produce beta-lactamase enzymes, making them resistant to certain antibiotics. Your doctor will work with you to choose the most effective treatment based on this and other factors.
Can I take antibiotics before this test?
Yes, you can take antibiotics before the test, but it may affect the results. If you’ve been prescribed antibiotics recently, let your doctor know so they can interpret the results accurately and adjust treatment plans if needed.
How long will it take to get the results?
Results typically take 3 to 7 business days, depending on the lab’s processing time. Your doctor will contact you once the results are ready, either through a phone call or a follow-up visit.
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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 16, 2026. · Read our editorial policy