Understanding Your Laboratory Test: What It Is, How the Sample Is Collected, and How It Is Analyzed
A laboratory test that identifies bacteria in shallow wound infections to help guide antibiotic treatment.
{"This test identifies the specific type of bacteria causing a wound infection","Results help doctors choose the most effective antibiotic treatment","Sample is collected from the wound surface using a sterile swab"}
Key facts at a glance
- LOINC
- 17918-4
- Short code
- BACTID4WC
- Synonyms
- Bacteria Shlw Wnd Aerobe Cult org #4
- Category
- chemistry
- Sample
- serum
- Container
- Sterile culture swab (e.g., Amies or Stuart's transport medium) or sterile leak-proof container for aspirates and tissue; sterile screw-cap tube with transport medium
- Units
- N/A
- Ref low
- 48
- Ref high
- 72
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- aerobic-culture
- CPT
- 87077
- SNOMED
- 399057004
- Specimen volume
- A small amount of wound exudate, pus, or tissue is sufficient; ideally a minimum of 0.5-1 mL of fluid or a visible piece of tissue (approximately 1-2 cm³). For swabs, the swab tip should be visibly saturated.
- Stability
- Transport to laboratory within 2 hours at room temperature; if delayed, specimens in Amies or Stuart's transport medium are stable up to 24 hours at room temperature or refrigerated (2-8°C). Tissue and aspirate specimens should be processed within 2 hours or stored at 2-8°C for up to 24 hours.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 48–96 hours
- Order
- routine
This test is a laboratory examination performed on a sample from your body, such as blood, urine, or another fluid or tissue. Your healthcare provider may order it to check how well your organs are working, screen for disease, confirm or rule out a diagnosis, or monitor a condition you already have and how well your current treatment is working.
The Wound Bacterial Culture test (also known as aerobic wound culture) is a laboratory test that identifies and grows bacteria from a shallow wound to determine what germ is causing an infection. This helps your healthcare provider choose the right antibiotic to treat your wound.
How your sample is collected depends on the type of test your provider has ordered. Most often, a trained professional draws a small amount of blood from a vein in your arm using a sterile needle, but some tests require a urine sample, a throat or nasal swab, or another specimen collected at a clinic, a draw station, or sometimes in your own home.
A healthcare professional will gently swab the surface of your wound with a sterile cotton tip or use a special collection device. The sample is then placed in a sterile container and sent to the laboratory for analysis. The area may be cleaned with saline before sampling to remove debris.
Once your sample arrives at the laboratory, it is logged, labeled, and prepared for analysis. Trained laboratory professionals process it using specialized instruments and chemical procedures, follow strict quality-control steps to make sure the results are accurate, and then review the findings. The final report is sent to your healthcare provider, who will explain what the results mean for your health.
In the lab, the sample is placed on growth media and kept at body temperature. If bacteria are present, they will multiply and form visible colonies within 24-48 hours. Technicians then identify the specific type of bacteria and test which antibiotics can effectively kill them (called sensitivity testing).
Reference range
No aerobic bacteria isolated after standard incubation period (typically 48-72 hours). Result is reported as identification of the fourth (4th) most clinically significant aerobic bacterial isolate from the wound culture, including genus and species when available.N/A
No special patient preparation (fasting not required). If possible, wound should not be treated with topical antibiotics or antiseptics for at least 24-48 hours prior to specimen collection. The collection site should be cleaned of superficial exudate and necrotic debris before sampling to avoid contamination with colonizing flora.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is crucial for diagnosing wound infections and determining appropriate treatment. Common wound-infecting bacteria include Staphylococcus aureus, Streptococcus species, and Pseudomonas aeruginosa. Identifying the exact organism helps doctors prescribe targeted antibiotics rather than broad-spectrum drugs, which reduces antibiotic resistance and improves healing outcomes.
Frequently asked questions
How long does it take to get results?
Does this test hurt?
Do I need to prepare for this test?
What if no bacteria grow in the culture?
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