Why take a urine test for culture? This is a common question. We will understand in this article.
All inflammations of the bladder, kidneys, urethra ninety-five percent are provoked by infectious agents, the main ones being Proteus, Staphylococcus and Enterobacteria. They are called uropathogenic flora. To identify the source of the patient’s disease, a tank is taken . sowing urine of the patient. This method requires strict observance of urine collection standards, special equipment with media and thermostats, as well as competent specialists.
Where are they held?
Urine tests are performed for culture in bacteriological laboratories. If necessary, they can also be done in private clinics. But more often than not, they simply accept the material, and then transfer it to a centralized institution in which there are necessary conditions. This is due to the fact that the following conditions are necessary for the analysis:
- purchase and maintenance of the latest equipment;
- maintenance of culture media ;
- establishment of the process of disinfection and destruction of infected urine;
- maintaining continuous training of specialists.
Often during transportation, the storage conditions of the biomaterial and the time frame are violated. Therefore, it is best to do bacterial urine culture in a specialized institution, since the results there will be more reliable.
In which cases a tank is required. sowing?
If an ordinary urinalysis for sowing is performed, then a microscopy of its sediment must be carried out, during which fungi and bacteria are detected. If their number in the field of view is too large, then this indicates bacteriuria. The main disadvantage is the lack of any information about a specific variety of pathogen.
In a conventional laboratory, specialists will be able to visually differentiate only a small number of microbes. To make a more accurate differentiation, Gram stain, as well as microbiological studies using special microscopes, are necessary. How is urine culture microflora carried out?
Ways
Among the modern methods include electron and luminescent microscopy, in which pathogens are illuminated by luminous dyes, or the apparatus has such a resolution that allows you to discern even individual structural characteristics of the microorganism. How to pass urine? About it below.
For such a detailed method, it may not be necessary to plant urine on special media. However, in any case, it is produced only in the microbiological department of laboratories. The doctor should be aware of:
- about the cause of inflammation;
- the size of the concentration of pathogenic microorganisms;
- the sensitivity of the pathogen to certain antibiotics.
All this information is necessary for the correct prescription of drugs, especially if the disease becomes chronic or protracted.
Who can come in handy?
Examination of urine through a tank. Sowing can be useful for patients with the following pathological processes:
- relapses of cystitis;
- chronic urethritis;
- pyelonephritis and pyelitis;
- paranephritis.
Pathogenic flora should be detected in the urinary tract on time when monitoring the condition of people with HIV and diabetes.
Requirements for the implementation of bacteriological studies of urine
To obtain reliable information on the analysis of urine for sowing, you must strictly adhere to a number of rules and requirements:
- analysis must be done only before treatment with antibiotics;
- only morning urine is suitable for research, more precisely, its average portion;
- urine can not be collected from the urinal, vessel, for the correct delivery of the material it is necessary to use sterile containers, which can be purchased at a pharmacy or taken in a specialized laboratory;
- bacteriological sowing of urine is carried out for two hours after the material has been taken, it can be kept in the refrigerator for up to eight hours;
- if there is a suspicion of renal tuberculosis, the study should be carried out three times, that is, for three days;
- catheter urine should be taken with the maximum restriction, since infection can spread during the procedure.
What does urinalysis for culture show? Let's figure it out.
A number of recommendations suggest:
- stop the use of diuretics in two days (both herbal and diuretics);
- exclude the use of alcohol, fatty and salty foods a week before analysis.
Such recommendations are common for any research conducted in the laboratory. However, bacteriologists believe that these tips do not have any decisive influence on the qualitative characteristics of the absorption of microorganisms. How to pass urine, you can also check in the clinic.
Is it possible to find out the source of infection from the analysis?
To distinguish between inflammatory processes in the bladder and kidneys, a test is performed with Neomycin or Polymyxin: after the bladder is emptied, fifty milliliters of the solution containing antibiotics are introduced into it with a catheter. Then, after ten minutes, a urine sample is taken for research. After microscopy, the following data can be obtained:
- with complete sterility, as a result of the analysis, it can be judged that inflammation occurs in the bladder;
- if the infection is observed in the kidneys, then bacteriuria remains, since the local effect of antibiotics did not affect the upper parts of the urethra.
How is the average portion of urine taken?
In order for the urine analysis to be inoculated to be as effective as possible, it is necessary to prepare the outlet of the urethra in a special way to avoid additional infection.
Women can not give urine during menstruation and within two days after its completion. At this time, fresh blood will interfere with culture and microscopic examination. Two days before the analysis, the use of birth control and medications in the form of vaginal suppositories is not recommended.
It is necessary to thoroughly wash the external genitalia with soap, or wipe with a towel previously moistened with a solution of povidone-iodine. For this purpose, you need to use four swabs and hold them in the direction from front to back. Then the genitals should be washed with clean water. In the morning, douching is prohibited to avoid dilution of urine. Often prescribed a urine test for culture during pregnancy. The direction is issued by an obstetrician-gynecologist.
In men
Men are sent for analysis by the attending physician (therapist or urologist), if there are clinical indications. To prevent the penetration of sexual infection, it is necessary to wash the penis with a soap, a fold of the foreskin and genitals with soap. Material is taken during urination. Urination must be delayed after the first stream, then collect the next urine in a sterile container in an amount of twenty to fifty milliliters.
Young children should be washed with a detergent, give them water, then put on their knees over a sterile bag and wait for urination.
After the material is collected, the container must be closed. At room temperature, it can be stored for no more than two hours (including here also the time of its delivery to the laboratory). If special preservatives are used, then urine is allowed to be transferred to the tank. study throughout the day. The rate of urine culture will be presented below.
Features of bacteriological research
Sequence holding tank. studies of urine or other material includes a number of standard manipulations:
- microscopy of the sediment of the primary type (can be skipped according to indications);
- tank. sowing primary urine to isolate a pure culture of infectious pathogens;
- the accumulation of this culture;
- analysis of the biological characteristics of the isolated microorganisms;
- the final definition of the pathogen.
All bacteriologists adhere to these stages.
For the primary tank. sowing should be selected medium corresponding to a certain class of pathogens. For example, sugar broth is suitable for streptococci, blood agar is suitable for staphylococcus, Saburo's medium is needed for mushrooms.
Sowing can be carried out simultaneously on 2-3 environments. His technique is determined by the purpose of the analysis, the choice is made by the laboratory assistant. The most common crops do:
- spatula;
- strokes through a specific bacteriological loop;
- a swab soaked in material.
You can also break the bottom of the Petri dish into separate sections and sow each of the sectors. How much urine analysis is preparing for the tank. sowing?
How are the results analyzed?
The study of the results of the analysis of urine culture on bacterial media begins on the second day. It describes:
- size (from small to large);
- transparency;
- shape (right or wrong, round);
- color, that is, the type of coloring;
- surface features (rough, smooth or bumpy);
- growth in height (flat or dented).
Under the microscope, you can see the structural characteristics of the bacterial colony (heterogeneous or homogeneous), uneven or even edges. To accumulate it, a separate colony is subcultured into a test tube with mowed agar located in it. Two days later (on the third), biochemical tests are carried out with the obtained pure culture, the basis of which are the ability to break down sugars, fats and proteins. Special test strips are also used, on which a bacterial culture is dripped, and then the result is controlled.
All results of the identification of the pathogen are included in the decryption of the analysis. On their basis, the bacteriologist can make a conclusion about the nature of the agent of infection, its significance in the occurrence of the disease.
If intraspecific diagnosis is required (for example, you need to find out which of the many types of staphylococcus is in the urine of a particular patient), you need to additionally use immunological reactions. Analyze urine culture for microflora should be a qualified specialist.
Quantitative result indicator
To reflect the results quantitatively, in bacteriology they operate with colony forming units, or CFU, located in one milliliter of urine. Evaluation is carried out by their size.
If the indicator fluctuates from a thousand to one hundred thousand, one can suspect that the urine was collected with irregularities that affected the result, so in this situation it is better to do the analysis again. Proper decoding of urine culture is very important.
The interpretation of the results is a characteristic of various nosological forms :
- with pyelonephritis - 1000 CFU or more;
- with cystitis - 100 CFU.
If the CFU index exceeds 100,000, then there is no need to doubt the activity of the pathogen. It is urgent to begin treatment, since such a picture happens with a catheter infection.
Tank. urine culture for antibiotic sensitivity
To determine the optimal method of therapy, you can use the culture analysis for its sensitivity to various antibiotics. Its result is also called an antibioticogram.
What is the essence of this study? It is necessary to divide the Petri dish into parts and place in each strip or circle soaked in antibiotic. Their marking is carried out either from the outside of the cup, or by color.
Pure culture is sown in the sector. Then the cup is placed in a thermostat having a human body temperature, and is monitored daily. If the antibiotic is perfect, then it will kill the bacteria, and there will be no growth in the sector. In the case of pathogen resistance, colony growth will be noted.
To get the result, you need to wait four to five days. Thanks to new methods, a study can be completed in two days, and not only the sensitivity of the drugs, but also their therapeutic dose will be determined.
We found out what urine analysis shows for culture.