Urine culture
What is being analysed?
Urine culture is a laboratory test used to detect and identify the presence of bacteria or other microorganisms in a urine sample. It helps in diagnosing urinary tract infections (UTIs) and determining the most effective treatment.
When is it requested?
A urine culture is typically requested when a patient exhibits symptoms of a UTI, such as frequent urination, burning sensation during urination, cloudy or foul-smelling urine, pelvic pain, or fever.
Why perform the analysis?
The analysis is performed to confirm the presence of a urinary tract infection and to identify the specific bacteria causing the infection. This information is crucial for prescribing appropriate antibiotic therapy.
When should the analysis be done?
A urine culture should be done when a patient presents with symptoms suggestive of a UTI or when there is clinical suspicion of a urinary tract infection.
What sample is required?
A clean-catch midstream urine sample is typically required for urine culture. This involves collecting a sample of urine in the middle of the stream after the initial flow has been allowed to pass.
Is any prior preparation necessary?
Yes, it's essential to clean the genital area thoroughly before collecting the urine sample to prevent contamination. Patients may be instructed to avoid certain medications or dietary supplements that can affect the results.
How is it used?
The urine sample is cultured on special agar plates in the laboratory, allowing any bacteria present to grow. After incubation, the colonies of bacteria are identified and tested to determine which antibiotics they are susceptible to, guiding treatment decisions.
Normal values and interpretation
|
Parameter |
Normal Values |
|---|---|
|
Bacterial growth |
No significant growth after 24-48 hours of incubation |
|
White blood cells |
<5 per high power field (HPF) in centrifuged specimen |
|
Red blood cells |
<2 per high power field (HPF) in centrifuged specimen |
|
Epithelial cells |
<5 per high power field (HPF) in centrifuged specimen |
What does having altered values mean?
- Bacterial growth: Significant bacterial growth indicates the presence of a urinary tract infection.
- White blood cells (WBCs): Elevated WBC count suggests inflammation or infection in the urinary tract.
- Red blood cells (RBCs): Presence of RBCs may indicate inflammation, infection, or other urinary tract disorders.
- Epithelial cells: Increased numbers of epithelial cells may suggest contamination of the sample or inflammation of the urinary tract.