Understanding Your Laboratory Test: A Patient's Guide to Testing, Sample Collection, and Interpreting Your Results
This test detects antibiotic-resistant bacteria in anal samples to help prevent the spread of difficult-to-treat infections in healthcare settings.
{"Screens for antibiotic-resistant bacteria (CRE) that are hard to treat","Uses a simple swab sample from the anal area","Helps hospitals prevent outbreaks and protect other patients","Results guide infection control measures","A positive result does not always mean you have an active infection"}
Key facts at a glance
- LOINC
- 73834-4
- Short code
- CREAN
- Synonyms
- Bacteria.carbpm resist Anal Cult
- Category
- chemistry
- Sample
- serum
- Container
- Sterile transport swab system (e.g., Copan ESwab, BD ESwab, or Amies/Charcoal transport medium). Rectal/anal swab collected and placed in transport medium. For carbapenem-resistant organism screening, use of selective enrichment broth (e.g., Tryptic Soy Broth with carbapenem disk) or direct inoculation onto selective chromogenic agar (e.g., ChromID CARBA, Chromagar Orientation) is recommended.
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- organism-specific-culture
- CPT
- 87046
- SNOMED
- 122451000221106
- Specimen volume
- One anal/perianal swab collected by inserting sterile swab 2-3 cm beyond the anal sphincter, rotating gently to sample mucosal surface. Alternatively, perianal skin swab or stool specimen may be submitted.
- Stability
- Transport to laboratory within 2 hours of collection at room temperature, or within 24 hours if refrigerated at 2-8°C. Specimens in Amies or similar transport medium are stable for up to 48 hours at room temperature or 72 hours refrigerated per CLSI guidelines. Do not freeze.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 48–168 hours
- Order
- routine
This test is a laboratory analysis performed on a sample from your body, such as blood, urine, or tissue, to help your healthcare provider assess your health, screen for disease, monitor an existing condition, or guide decisions about your treatment.
This test looks for carbapenem-resistant bacteria in a sample collected from the anal area. Carbapenem antibiotics are powerful drugs used to treat serious infections. When bacteria become resistant to these antibiotics, they are called carbapenem-resistant organisms (CRO) or carbapenem-resistant Enterobacteriaceae (CRE). These resistant bacteria can cause severe infections that are difficult to treat.
Your doctor may order this test to confirm or rule out a suspected condition, check how well organs such as the kidneys, liver, heart, or thyroid are working, evaluate symptoms you have reported, track the progress of a known illness, or see how well your current treatment is working over time.
Healthcare providers order this test primarily for infection control purposes. It helps identify patients who may be carrying these resistant bacteria without knowing it (called colonization). This information is crucial for preventing the spread of these dangerous bacteria in hospitals and other healthcare facilities, especially in high-risk areas like intensive care units.
The sample is usually collected in a clinical setting by a trained healthcare professional. Depending on the type of test, this may involve drawing blood from a vein in your arm, asking you to provide a urine specimen, or obtaining a small swab or tissue sample. Some tests require fasting or other simple preparation, and your care team will give you specific instructions to follow before your appointment.
A healthcare provider will gently insert a sterile swab into the anal canal to collect a sample. The procedure is quick but may cause brief discomfort. The sample is then sent to a laboratory where it is cultured (grown) to identify any bacteria present and test whether they are resistant to carbapenem antibiotics.
Your results are compared with established reference ranges to show whether your values fall within normal limits. Abnormal results do not always mean you have a serious illness; they can be influenced by medications, diet, hydration, or recent physical activity. Your healthcare provider will review the findings with you, explain what they mean in the context of your overall health, and recommend any follow-up testing, treatment, or lifestyle changes if needed.
A negative result means no carbapenem-resistant bacteria were found in the sample. A positive result indicates that carbapenem-resistant bacteria were detected. However, a positive result does not always mean you have an active infection—it may mean you are colonized (carrying) these bacteria. Your healthcare team will determine if treatment is needed based on your symptoms and overall health condition.
Reference range
Negative for carbapenem-resistant bacteria. No growth of carbapenem-resistant organisms detected in anal/perianal swab culture. Results reported as organism identified (e.g., Carbapenem-resistant Enterobacteriaceae [CRE], carbapenem-resistant Pseudomonas aeruginosa, carbapenem-resistant Acinetobacter baumannii) with associated carbapenem resistance profile.N/A
No special patient preparation required. Specimen should be collected prior to initiation of antimicrobial therapy whenever possible. If patient is on antibiotics, document current antibiotic regimen. Perianal/anal area should not be cleansed with antiseptic solutions immediately prior to specimen collection as this may inhibit organism recovery.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test plays a critical role in infection control and prevention. Carbapenem-resistant bacteria are a major global health concern because they cause infections that are extremely difficult to treat with standard antibiotics. Identifying colonized patients allows healthcare facilities to implement special precautions (such as isolation protocols) to prevent transmission to other vulnerable patients. This screening is particularly important before certain medical procedures, during hospital outbreaks, and for patients being transferred between healthcare facilities.
Frequently asked questions
Does a positive result mean I am sick?
Is this test painful?
Do I need to prepare for this test?
What happens if the test is positive?
Can these resistant bacteria be treated?
Sources
- 1
- 2
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