Bacteriological sowing( bacussis) - Causes, symptoms and treatment. MF.

Bacteriological seeding( bakposev) is a microbiological laboratory study of a human biological material by sowing it on certain nutrient media under a certain temperature regime in order to detect the presence of any number of pathogenic and conditionally pathogenic microorganisms in it and further solving the problems of specific treatment.

Bakposev

In the isolation of certain microorganisms, the second important analysis is carried out - antibiogram - the sensitivity of the detected pathogens to antibacterial drugs and bacteriophages.

The advantages of bacteriological seeding are:

• High specificity of the method( that is, no cross-spurious reactions are observed).
• The ability to explore absolutely any biological fluid of a person.
• Therapeutic goal - to determine the sensitivity of the detected microbe to a particular medicine( antibioticogram), which allows to conduct medical appointments with high accuracy.

Disadvantages of bacteriological inoculation:

• Duration of the result.
• High material collection requirements.
• Certain requirements for the qualification of personnel in bacteriological laboratories.

Indications for bacteriological research

The application of the microbiological method of investigation is widely used in medical practice, in particular, in infectious diseases, gynecology, urology, surgery, otolaryngology, oncology and others. An unconditional indication for the need for carrying out bapsoseva are any inflammatory disease of organs and systems of the human body, suspicion of the septic process.

Material for bacteriosia

The following biological media of the human body are taken for the study: nasopharyngeal mucus, phlegm mucus, secretions of the bronchial tree( sputum), faeces, urethra mucus, cervical canal, prostate secretion, urine, blood, cerebrospinal fluid,milk, bile, contents of cysts, inflammatory foci, wounded discharge.

bacteriological laboratory

What microorganisms can be identified by

bakposeve in nasal mucus and throat can detect hemolytic streptococci( Streptococcuc pyogenes, Streptococcuc agalactiae), pneumococci( Streptococcuc pneumoniae), Staphylococcus aureus( Staphylococcus auereus), korinobakterii diphtheria( Corynebacterium diphtheriae), Haemophilus influenzae( Haemophilus influenzae type b), meningococcus( Neisseria meningitidis), listeria( Listeria).

In feces try to identify the intestinal group of bacteria - salmonella and shigella( Salmonella spp., Shigella spp.) Yersinia( Iersiniae spp.), Typhoid paratyphoid group of bacteria( Salmonella typhi, Salmonella paratyphi A, Salmonella paratyphi B), opportunistic pathogensintestinal infections, anaerobic microbes, pathogens of food toxic infections, and also to examine feces for intestinal dysbacteriosis.

Pseudomonas or Pseudomonas aeruginosa( Pseudomonas aeruginosa) can be detected in the contents of wounds, biopunctate, purulent discharge.

Mucus of the urogenital tract is examined for the presence of causative agents of sexually transmitted infections - gonococcus, trichomonas, fungi( Neisseria gonorrhoeae, Trichomonas vaginalis, Candida fungi), ureaplasma urealyticum, mycoplasma hominis, Listeria,, it is also possible to examine a smear for bacterial flora.

Blood can be sown( examined) for sterility.

Materials such as breast milk, urine, the secret of the prostate, scraping, swab, wound contents, articular fluid, bile are examined for general dissemination( bacterial flora).

What is a bacteriological culture?

The material for the research in the bacteriological laboratory is placed( sowing) on ​​special nutrient media. Depending on the desired search for a particular pathogen or group of pathogens, the crop is sown to different media. For example, it can be a selective or selective nutrient medium( for the growth of a single pathogen, the growth of other microbes is inhibited), an example of which may be coiled horse serum to identify diphtheria causative agents or a medium with selenite or bile salts to detect intestinalpathogens.

Another example may be differential-diagnostic environments( Hiss's medium), which are used to decipher bacterial cultures. If necessary, the liquid nutrient media is made by reseeding on solid media in order to identify the colonies more.

Bakposev. Colonies on a solid medium

Then the nutrient media is placed in a thermostat( special device), in which favorable conditions( temperature, humidity, etc.) are created for the growth and multiplication of pathogens, there is a certain time in the medium thermostat.

Next, a control examination of the grown up colonies of microorganisms is carried out, which is called the "culture of microorganisms".If necessary, microscopy of the colony material is carried out with preliminary dyeing with special dyes.

What is assessed during a follow-up inspection? This is the shape, color, density of the colonies, after additional research - the ability to decompose some inorganic and organic compounds.

Next, count the pathogens. Microbiological research takes into account such a concept as colony-forming unit( CFU) - one microbial cell capable of forming a colony, or a visible colony of microbes. In CFU it is possible to determine the concentration or the number of microorganisms in the test sample. The calculation of CFU is carried out by different methods: counting colonies under a microscope, by serial dilution method, by the sector method.

Rules for the collection of biological material for bacteriological culture

The quality of the bacteriological culture in progress depends to a large extent on the correctness of the material sampling for the study. It is necessary to remember a simple rule: sterile dishes and sterile tools! Failure to comply with these requirements will lead to contamination( external contamination of the material by skin and mucous membranes, the environment having no clinical significance), which will automatically render the study meaningless. For the collection of the material, sterile dishes are used, which is issued in the bacteriological laboratory itself to the patient's hands during an outpatient examination, for the collection of feces, urine. From various inflammation foci, the fence is carried out only with sterile instruments( spatulas, loops, spoons) by a specially trained medical worker( in a polyclinic, this is usually a nurse of infectious or examination rooms).

Blood and urine are collected in dry test tubes, the remaining materials in dishes with a transport nutrient medium.

Sterile utensils for urine and feces removal

Another rule: taking the material before the antibiotic therapy begins! On the background of taking antibiotics, the result will be significantly distorted. If you take such drugs, then stop taking them 10 days before the test and tell your doctor about the fact of taking any antibacterial drugs.

Fast delivery to the laboratory should be ensured! Microorganisms can die on drying, changing acidity. For example, feces should be delivered in the warm form of .

With urine collection: after morning hygienic procedures, the average portion of morning urine in the amount of 10-15 ml is taken into sterile dishes. Delivered to the laboratory for 2 hours.

When taking a swab from the pharynx and nose: it is impossible to brush your teeth in the morning, rinse your mouth and nose with disinfectant solutions, drink and eat.

The feces removal should be done in the morning with a sterile spatula in sterile dishes in a volume of 15-30 g. It is unacceptable to get into the urine sample. Delivery within 5 hours. Do not freeze or store at night. Collect feces without the use of enemas and laxatives.

Blood for the bacterium is taken before the onset of antibiotic therapy when the temperature rises to a sterile tube in an amount of at least 5 ml( children), not less than 15 ml( adults).

Sputum is collected in the morning on an empty stomach in a sterile container during an attack of coughing with mucus. Before the fence brush your teeth and rinse your mouth with boiled water. Delivered to the laboratory within 1 hour.

Breast milk is collected after a hygienic procedure. The sucking area is treated with a tampon moistened with 70% ethyl alcohol. The first 15 ml of expressed milk is not used. Then 5 ml is decanted into a sterile container. Delivered within 2 hours.

Detachable genitals: in women the fence is performed no earlier than 14 days after menstruation, not earlier than 1 month after the abolition of antibiotics, it is advisable not to urinate for 2 hours;in men - it is not recommended to urinate for 5-6 hours before sampling.

Timing of bacteriological planting

When examining mucus from the nasopharynx, the result will be ready in 5-7 days, the study of stool takes about 4-7 days. When examining a scraping of the urogenital tract, the duration of the examination will take 7 days. Sowing on the common flora lasts 4-7 days. Most of the time the blood is prepared for sterility - 10 days. However, the earliest preliminary result can be given in 3 days.

The result of bacteriological examination of

The result of bacterosseum is both the qualitative assessment( the fact of the presence of the pathogen in the test sample) and the quantitative evaluation( concentration of the pathogen in the material).

The decoding of the quantitative result is carried out in the simplest way. There are 4 degrees of growth( dissemination) of microorganisms in the material under study. For 1 degree of growth, lean growth is characteristic only of the liquid medium, on solid - there is no growth;for the 2nd degree - growth on a dense medium up to 10 colonies of the same species;for grade 3 - from 10 to 100 colonies;for 4 degrees - more than 100 colonies.

This is important for conditionally pathogenic flora, in the detection of which 1 and 2 degree is not considered the cause of the disease, it simply indicates the contamination of the material for the study, 3-4 degrees indicate the etiology( cause) of the disease. If a pathogenic flora is identified, then all the allotted colonies, that is, all 4 degrees, are taken into account.

The result of colony counting in CFU / ml is interpreted as follows: 103 / ml means detection of 1 colony;104 / ml - from 1 to 5 colonies;105 / ml - growth of 5-15 colonies;106 / ml - more than 15.
Quantitative result is important not only for determining the degree of dissemination, but also for monitoring the correctness of the treatment.

Antibioticogram

Determination of the sensitivity of the isolated microorganism to a particular antibacterial preparation is an important component of bacteriological research. A set of drugs to which the causative agent is sensitive or resistant is antibioticogram .

Antibioticogram

Sensitivity of the pathogen is a susceptibility to a drug, that is, an antibiotic will affect the growth and reproduction of the microbe. Resistance - the resistance of the causative agent to a particular drug, that is, an antibacterial drug does not work.

Antibiocogram is given in certain units - the minimum inhibitory concentration( MIC).

The doctor infektsionist Bykova N.I.