Content
Uroculture with antibiogram is a laboratory exam requested by the doctor that aims to identify the microorganism that causes the urinary tract infection and its profile of sensitivity and resistance to antibiotics normally used to treat the infection. Thus, from the result of the exam, the doctor can indicate the most appropriate antimicrobial for the person.
The performance of this test is usually indicated when the person shows signs and symptoms of urinary infection, however it can also be requested when after examination of type I urine, the EAS, bacteria and numerous leukocytes in the urine are identified, because these changes are indicative of urinary infection, and it is important to identify the responsible microorganism.
What is the purpose of urine culture with antibiogram
The urine culture test with antibiogram serves to identify the microorganism responsible for the urinary change and which antimicrobial can be used most effectively in its fight.
This test is mainly indicated in case of urinary infection, and can be ordered after the result of the type 1 urine test, the EAS, or when the person shows signs and symptoms of urinary infection, such as pain and burning when urinating and frequent desire to have Pee. Learn to identify the symptoms of urinary tract infection.
This test serves to identify the presence and the antimicrobial sensitivity profile of some microorganisms, the main ones being:
- Escherichia coli;
- Klebsiella pneumoniae;
- Candida sp .;
- Proteus mirabilis;
- Pseudomonas spp .;
- Staphylococcus saprophyticus;
- Streptococcus agalactiae;
- Enterococcus faecalis;
- Serratia marcenses;
- Morganella morganii;
- Acinetobacter baumannii.
The identification of other microorganisms that may also be related to urinary tract infection, such as Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma spp. and Gardnerella vaginalis, for example, most of the time it is not done through urine culture, in which case it is usually requested to collect vaginal or penile secretions so that the microorganism can be identified and the antibiogram, or urine analysis through molecular methods .
How to understand the result
The result of urine culture with antibiogram is given in the form of a report, in which it is indicated whether the test is negative or positive and, in these cases, which microorganism was identified, its quantity in the urine and the antibiotics to which it was sensitive and resistant.
The result is considered negative when there is only growth in normal amounts of microorganisms that are naturally part of the urinary system. On the other hand, the result is positive when there is an increase in the quantity of any of the microorganisms that are part of the normal microbiota or when the presence of an unusual microorganism is verified.
Regarding the antibiogram, in addition to informing whether the microorganism is sensitive or resistant to the antibiotic, it also indicates the Minimum Inhibitory Concentration, also called CMI or MIC, which corresponds to the minimum concentration of the antibiotic that is capable of inhibiting microbial growth, being this very important information for the doctor to indicate the most appropriate treatment.
Uroculture with antibiogram for Escherichia coli
THE Escherichia coli, also known as E. coli, is the bacterium most often associated with urinary infections. When the urine culture is positive for the bacterium, the amount indicated in the urine, which is normally above 100,000 colonies, is indicated in the report, and to which antibiotics are sensitive, being usually Phosphomycin, Nitrofurantoin, Amoxicillin with Clavulonate, Norfloxacino or Ciprofloxacino .
In addition, the MIC is indicated, which in the case of Escherichia coli, for example, it is determined that the MIC for Ampicillin less than or equal to 8 µg / mL is indicative of susceptibility to the antibiotic, and its use for treatment is recommended, while values equal to or greater than 32 µg / mL indicate that the bacteria is resistant.
Thus, according to the results obtained by urine culture and the antibiogram, the doctor can indicate the best treatment for the infection.
How it is done
The urine culture test is a simple test that is done from a urine sample, which must be collected and stored in a suitable container provided by the laboratory. To perform the collection, it is necessary to first clean the intimate area with soap and water and collect the first urine of the day, and the person must ignore the first stream of urine and collect the intermediate stream.
It is important that the sample is taken to the laboratory within 2 hours in order to be viable for urine culture and antibiogram. In the laboratory, the sample is placed in a culture medium that favors the growth of microorganisms normally present in urine. After 24h to 48h, it is possible to verify the growth of microorganisms and, thus, it is possible to carry out microbial identification tests.
In addition, from the moment that the growth of microorganisms is observed in the culture medium, it is possible to check the number of microorganisms, and it can be indicated that it is a matter of colonization or infection, in addition to also being possible to perform the antibiogram, in which the microorganism is tested for different antibiotics, being checked for which antibiotics are sensitive or resistant. Understand more about the antibiogram.