A urine sample is processed for culture to identify any bacteria or yeast present and determine the best antibiotic to treat an infection. The process involves several key steps:
-
Sample Collection: A clean-catch midstream urine sample is collected in a sterile container. This method minimizes contamination from bacteria normally present on the skin. Typically, at least 1-2 ounces (30-60 ml) of urine is needed.
-
Incubation: The urine sample is then incubated in a laboratory setting, typically for 24-48 hours. This incubation period allows any bacteria or yeast present in the sample to multiply to detectable levels.
-
Identification and Quantification: After incubation, the lab technician examines the culture for growth. If bacteria or yeast colonies are observed, they are identified and quantified. The number of colony forming units (CFU) per milliliter (mL) of urine is determined. A significant number of CFU (e.g., >= 100,000 CFU/mL) often indicates a urinary tract infection (UTI).
-
Antibiotic Sensitivity Testing (AST): If bacteria or yeast grow to a significant level, an antibiotic sensitivity test, also known as a susceptibility test, is performed. This test determines which antibiotics will be effective in killing or inhibiting the growth of the identified microorganism. The results of this test guide the healthcare provider in prescribing the most appropriate antibiotic for treatment.
Here's a table summarizing the process:
| Step | Description |
|---|---|
| Sample Collection | A clean-catch midstream urine sample is collected into a sterile container. |
| Incubation | The sample is incubated for 24-48 hours to allow bacteria or yeast to multiply. |
| Identification | The culture is examined for growth. If present, the bacteria or yeast are identified and the number of colony forming units (CFU) is determined. |
| Antibiotic Testing | If bacteria or yeast growth is significant, antibiotic sensitivity testing is performed to determine which antibiotics will be effective. |
In summary, processing a urine culture involves collecting a sterile sample, incubating it to allow for microbial growth, identifying and quantifying any organisms that grow, and performing antibiotic sensitivity testing to determine the most effective treatment options.
