A urine culture test is a diagnostic examination that analyses a urine sample to check for bacteria or yeast that could be causing a urinary tract infection (UTI). It is an important test for diagnosing UTIs and determining the most effective antibiotic treatment. This article provides an overview of urine culture tests.

What is the urine culture test?

• A urine culture test, also called a urine culture examination, checks a urine sample for microorganisms, such as bacteria and yeast that can cause infections. 
• The test works by adding substances to the urine sample that promote the growth of bacteria and yeast. If present, the bacteria and yeast will multiply, indicating an infection. 
• A healthcare provider will order a urine culture test if a UTI is suspected based on patient symptoms. The test can identify the specific type of bacteria causing the infection.

Purpose of urine culture test

There are four main reasons doctors utilise urine culture tests:

• Detect and Diagnose UTIs: A positive urine culture confirms that a patient has a UTI requiring antibiotic treatment guided by the test results.
• Identify the Infecting Microorganism: Knowing the specific bacteria or yeast causing the UTI allows the doctor to prescribe the most suitable antibiotic to fight that germ.
• Confirm Antibiotic Effectiveness: A repeat urine culture after antibiotic treatment shows if the prescribed medications successfully cured the UTI.
• Investigate Recurrent UTIs: Identifying bacterial strains causing repeated UTIs guides prevention approaches to stop reinfection.

When is a urine culture test needed?

A urine culture may be needed if:

• Symptoms of a UTI are present, such as burning with urination, a frequent urge to urinate, and cloudy, bloody, or foul-smelling urine.
• Recurring UTIs or chronic UTIs that are difficult to resolve are evident.
• At-risk groups, such as those with diabetes, kidney problems, or weakened immune systems, may require a urine culture.
• To confirm UTI infection during pregnancy and prevent risks to the baby.

What happens during the urine culture test?

• A clean urine sample is required, meaning the genital area is thoroughly cleaned beforehand to avoid contamination. Handwashing is also critical.
• The fresh urine sample is collected mid-stream into a sterile container, with at least 1-2 ounces needed.
• This sample is incubated for 24-48 hours to allow any bacteria present to multiply to detectable levels.
• If bacteria or yeast grow, an antibiotic sensitivity test is also conducted to determine the best antibiotic.

Uses of urine culture test

• Detecting Urinary Tract Infections: Bacterial growth in culture indicates an active UTI, requiring targeted antibiotic treatment guided by test findings.
• Identifying Specific Bacteria: Recognizing the organism causing the infection allows doctors to select the most appropriate antibiotic to fight that germ.
• Confirming Antibiotic Effectiveness: Repeat testing after treatment shows if antibiotics have successfully cured the UTI.
• Investigating Recurring UTIs: Reveals bacterial strains involved in repeated infections to guide prevention of future recurrences.

Urine culture test procedure

• Patients wash their hands and genital area before collecting a midstream urine sample into a sterile container.
• Samples incubate 24-48 hours to allow microbial multiplication if infection is present.
• An antibiotic sensitivity test may also be done to guide the best antibiotic selection based on organisms found.

How painful is the urine culture test?

The urine culture test itself does not hurt. Patients typically do not report the laboratory analysis of the urine sample as being painful.

However, some temporary mild discomfort may happen during the sample collection process. Cleansing the genital area prior to urinating involves wiping of delicate tissues like the tip of the penis or labia, which may be slightly uncomfortable.

The release of urine from the urethra to collect a midstream sample can also cause mild stinging or burning if inflammation or infection is already present within the urinary tract. Difficult or slow urination can cause additional discomfort.

Once the sample has been obtained, no further pain is generally associated directly with the urine culture procedure itself. Specimens are handled with care to preserve the accuracy of the culture analysis.

Some tips to minimize discomfort during urine sample collection:

• Follow all preparation instructions given by your healthcare provider. This includes cleansing and handwashing steps designed to avoid contamination.
• Allow yourself privacy to focus, relax, and take your time providing the urine stream. Rushing increases the risk of spraying outside the collection cup.
• Making noise by running water can help trigger urine flow. Warm compresses beneath the urethra may also be beneficial.
• Speak up if you need a smaller sample container or an adjusted technique to make providing samples easier based on any existing pain or functional mobility limitations present.

While the test itself is not significantly painful, a confirmed urinary tract infection identified by the culture can require antibiotics and cause ongoing discomfort before healing progresses. Understanding your results is key to getting proper UTI treatment and relief from related pains.

Urine culture test preparation 

• Inform your doctor about any medications, medical conditions, or diseases that could impact the test results or your infection risk.
• You may be asked to refrain from urinating for 1-2 hours before providing a sufficient urine sample volume for the culture. 
• Drinking extra fluids before the test can help stimulate urine flow, facilitating easier sample collection.

What do urine culture test results mean (if it is low and higher than normal levels)?

• Normal Levels: No significant bacterial growth.
• Abnormal Levels: Substantial bacterial or yeast growth indicates a likely UTI. The specific organism found guides appropriate antibiotic treatment.
• Higher than normal levels: Indicates an active infection. Lower growth may represent partial treatment or resolving infections.

Abnormal test results showing microbial growth may include:

• Escherichia coli (E. coli) - the most common UTI-causing bacteria
• Group B Streptococcus (Strep B) - requiring antibiotic treatment
• Yeast, such as Candida - requiring anti-fungal medications
• Drug-resistant organisms - needing specialised medications to combat them

Follow your doctor’s prescribed medications to treat organisms found in the urine culture. Repeat urine cultures may be necessary to confirm infection clearance after treatment.

Conclusion

A urine culture is an essential diagnostic test that accurately detects urinary tract infections. Properly collected urine samples are cultivated to allow for the analysis of microbial growth. Positive culture results guide precise antibiotic therapy, while negative results indicate no infection. Understanding your urinalysis and any urine culture results is key to receiving the best treatment for UTIs.

FAQs

1. What is a normal urine culture level?

Ans: A normal urine culture will show no bacterial growth or fewer than 10,000 colony-forming units (CFUs) per millilitre. Any growth higher than this is abnormal and indicates infection.

2. What happens if the urine culture level is positive?

Ans: A positive urine culture means bacteria were detected in the urine sample, confirming a UTI diagnosis. Your doctor will prescribe antibiotic treatment targeted to the bacteria identified in the test.

3. What happens if the urine culture level is negative?

Ans: A negative urine culture result shows no significant bacterial growth, indicating no infection is present. Your doctor will investigate other potential causes of your symptoms.

4. What are some possible complications of the urine culture level?

Ans: If a UTI identified by an abnormal culture is left untreated, the infection can spread to the kidneys. Recurring UTIs over time can also cause kidney damage in some cases.

5. How long does the urine culture level take to perform?

Ans: After collecting the urine sample, the culture procedure takes 24-48 hours to allow adequate time for bacterial growth for analysis. Results are typically available within 72 hours.