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Uroculture, also called urine culture or urine culture, is an examination that aims to confirm urinary infection and identify which microorganism is responsible for the infection, which helps to determine the most appropriate treatment. To perform this test, it is recommended that the first urine in the morning be collected, dispensing with the first jet, however the urine culture test can be done from urine collected during the day.
Usually, together with urine culture, an antibiogram is requested, which is only performed by the laboratory when the result of urine culture is positive. Through this exam it is possible to know which antibiotics the bacterium is most sensitive or resistant to, helping to define the best treatment. Learn more about urine culture with antibiogram.
How to understand the result of urine culture
The result of the urine culture test can be:
- Negative or normal: when there is no growth of bacterial colonies in the urine at worrying values;
- Positive: when it is possible to identify more than 100,000 bacterial colonies, it is also indicated which bacteria are identified in the exam.
If an antibiogram was also requested, in the positive result, in addition to indicating the bacterium, it is also indicated to which antibiotics the bacterium was shown to be sensitive or resistant.
In some cases, when the collection or storage of the sample is not done properly, other results can be verified:
- False positive: it happens in situations where there is contamination of the urine by other microorganisms, blood or medication;
- False negative: it can happen when the pH of the urine is very acidic, below 6, or when taking an antibiotic or diuretic.
The result may still be doubtful if the number of colonies is less than 100,000, and it may be necessary to repeat the test.
However, it is necessary for the doctor to also evaluate other signs and symptoms that indicate urinary tract infection, to assess what type of treatment is necessary, according to each case. Learn to identify the symptoms that indicate urinary tract infection.
How the exam is done
To avoid changes in the result of the urine culture test, it is important that the person has some care when collecting and storing the sample. Therefore, to collect urine, it is necessary to follow the following step by step:
- Wash the intimate area with soap and water;
- Withdraw the lips from the vagina in the woman and retract the foreskin in the man;
- Discard the first stream of urine;
- Collect the rest of the urine in the proper container.
The urine can stay up to 2 hours at room temperature, however, the container must be delivered as soon as possible to the laboratory, so that the results are more reliable. The container where the urine is placed must be sterile and can be purchased at the pharmacy, but it can also be provided by the laboratory or hospital where the test will be performed and, preferably, it must be quickly closed and taken in a short time for laboratory analysis. , to avoid contamination.
Another way to collect the uroculture exam can be with the use of a tube, also called vesical catheterization, as a way to guarantee a collection as free of contamination as possible, but, generally, this type of collection is done in people who are in hospital .
Other tests to detect urinary tract infection
Although urine culture is the primary test for diagnosing urinary tract infection, the common urine test, also called urine type 1, EAS or routine urine, can also provide some evidence of urinary tract infection, such as the presence of bacteria, pocytes, leukocytes, blood, positive nitrite or changes in color, smell and consistency, for example.
Therefore, the doctor will be able to evaluate the result of this examination and observe the patient's symptoms and physical examination to identify the infection, without necessarily requesting urine culture, as it is a simpler examination and the result is faster, since urine culture may take up to 3 days to be ready. Understand what the urine test is for and how to do it.
However, urine culture is mainly necessary to assess whether the antibiotic used is the most suitable, to identify the bacterium in cases of repeated infections, pregnant women, the elderly, people who will undergo urinary tract surgery, or when there are doubts about that this is a urinary tract infection, for example.
When to do urine culture in pregnancy
The urine culture test is done during pregnancy for the obstetrician to assess whether or not the pregnant woman has a urinary tract infection which, if not properly treated, can cause childbirth ahead of time.
The urine culture test does not detect pregnancy, only if the pregnant woman has a urinary infection or not, but there is a specific urine test to detect pregnancy through the amount of the hormone hCG in the urine.