Urine C/S (Urine Culture and Sensitivity)
Understanding Urine C/S (Urine Culture and Sensitivity)
What is Urine C/S (Urine Culture and Sensitivity)?
The Urine C/S (Urine Culture and Sensitivity) test helps detect harmful bacteria and yeast (few candida spp.) in urine that may be causing a urinary tract infection (UTI). Additionally, this sensitivity test helps identify the antibiotics most effective against those particular bacteria. It is also used to determine if there is resistance to any antibiotics.
Urine is the body’s liquid waste made when the kidneys filter out toxins from the blood. It is made up of water, salt, electrolytes such as sodium and potassium, and some metabolic end products. The pathway followed by urine from the kidneys to the outside is called the urinary tract. Sometimes, this urinary tract may get infected by some microorganisms causing a UTI.
The Urine C/S (Urine Culture and Sensitivity) test is usually done when you experience symptoms of UTI, such as a burning sensation while passing urine, back pain, painful or frequent urination, blood in the urine, etc., for appx. 3-4 days and do not subside. This test helps to identify infection-causing microorganisms. If the results are positive, the sensitivity test helps determine which drugs (or antibiotics) are likely to be most effective for treating your infection. On the other hand, a negative urine culture indicates no signs of microbial infection, hence it will not show sensitivity to various antibiotics.
Before your test, make sure to drink enough water to be able to submit a urine sample for testing. The doctor may ask you to stop taking certain medications like antibiotics and supplements before a Urine C&S test as they may affect your test results. A mid-stream urine sample should be collected into a sterile container provided by the sample collection professional. Women are advised not to give the sample during the menstrual period unless prescribed as that can interfere with certain test results.
Test result ranges are approximate and may differ slightly between different labs depending on the methodology and laboratory guidelines. Talk to your doctor about your specific test results. Narrate your complete medical history to help the doctor correlate your clinical and laboratory findings. The test results will help them determine your medical condition and formulate your overall treatment plan.
What is Urine C/S (Urine Culture and Sensitivity) used for?
The Urine C/S (Urine Culture and Sensitivity) test can be done:
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If you have symptoms of UTI, such as frequent or painful urination, blood in urine, burning sensation while urinating, clouded or strong smelly urine, fever, and chills, back pain, or other urinary problems.
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As part of routine medical checkups.
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As part of a pregnancy checkup.
What does Urine C/S (Urine Culture and Sensitivity) measure?
The Urine C/S (Urine Culture and Sensitivity) test helps identify the bacteria or yeast (few candida spp.) causing UTI; the most common bacteria responsible for UTI is E.coli. Once the pathogen (harmful microorganism) is identified, the antibiotic susceptibility test is done to formulate a treatment plan for the infection.
Interpreting Urine C/S (Urine Culture and Sensitivity) results
Interpretations
Negative result: No colonies to less than 1,00,000 CFU/ml (Colony Forming Units)
Positive result:
· Usually more than 1,00,000 CFU/ml
· Patient undergoing antibiotic treatment: More than 1,000 CFU/ml
· For gram-positive bacteria like Staphylococcus aureus: Single colony
The negative result indicates no infection of the urinary tract.
The positive result indicates an infection of the urinary tract. An antibiotic susceptibility test accompanies the positive result.
Only a single colony type is found in an uncontaminated sample, indicating a clinically significant positive result. However, if multiple colonies of different types are found, sample contamination is indicated, and the sample may need to be collected again.