Techniques for conducting
To confirm the diagnosis, the patient's biomaterial sample is placed in a Petri dish - on the culture medium (which is called sowing). It can be a liquid or gel that provides nutrition for the growth of bacteria. For S. Aureus a mixture of agar, mannitol and 7-9% sodium chloride solution is used. The plates are then incubated overnight at + 37 ° C. After 48 hours yellowing of the agar plate on one side and typical golden colonies of S. Aureus are observed. They are necessarily stained with a Gram stain - to confirm that it is Gram-positive cocci.
Further, specific tests are carried out for the diagnostic identification of clinical isolates - tests with urea, nitrates, catalase, coagulase. Positive reactions serve as biochemical evidence of the presence in the test sample of Staphylococcus aureus.
The technique for carrying out the analysis for staphylococcus is quite complex, and the multistage process is associated with the need to differentiate it from similar microorganisms present in the biomaterial under study and to determine whether this bacterium belongs to enterotoxigenic or non-toxic species.
In emergency situations, rapid analysis of staphylococcus aureus by PCR (polymerase chain reaction) is carried out in clinical laboratories, which helps detect bacteria in real time and determine their number.
Analysis for carriage of staphylococcus aureus
Very important is the analysis of the staphylococcus culture from the nasopharynx: according to its results, the presence of S. Aureus bacteria is most often detected, which does not manifest itself in a healthy person with strong immunity, but may pose a danger of infection for others. And the level of colonization by staphylococci among medical workers, patients on dialysis and people with diabetes is higher than among the general population.
Approximately 30-35% of adults and most children are periodically healthy carriers of S. Aureus in the nasopharynx, but almost 15% of healthy adults are persistent carriers.
In the latter case, an analysis is required for staphylococcus aureus (sanitary book or special medical book - the form of the primary accounting documentation No. 1-OMC), which - by Cabinet of Ministers resolution No. 559 of 23.05. 2001 - there must be employees of certain professions (their list is attached). This is a bacterial staphylococcus or a test for the carriage of S. Aureus staphylococcus, for which a sample of nasal exudate (nasal seeding) or a mucous secretion of the oropharynx (smear from the pharynx) is examined.
We specify the number of the order for the analysis of staphylococcus, concerning the preventive medical examination - this is the order of the Ministry of Health of Ukraine №280 (from 23.07.2002). "The organization of obedient profiaktic medical examinations in prerequisites for vocational training, vibrobnits and organisations, yazana z obesluvovannanym populated area and can call to the widening of infectious wilderness. "
How often to take an analysis for staphylococcus aureus? Persons, whose profession is associated with the possibility of spreading bacteria, are supposed to take it every six months (some - once a year). To ordinary patients, the delivery of this test is prescribed by a doctor. In most cases, he also tells you where to pass the analysis for staphylococcus: in the laboratory of the medical institution, where the patient addressed, or in a separate accredited laboratory.
What analyzes hand over on a staphilococcus?
Depending on the localization of the pathology, the symptoms of its manifestation and the preliminary diagnosis for bacteriological research, such biomaterials as:
- A smear from the mucous membrane of the nasal cavity and from the pharynx;
- A smear from the outer mucosa of the eyeball (conjunctiva);
- a sample of a clearing secretion (sputum);
- discharge from the auricle;
- Urine (the average portion of urine released after waking up in the morning);
- stool specimen;
- a swab from the vagina (vaginal), from the cervical canal (cervical);
- smear from the anus (rectal);
- discharge from the wound (purulent exudate);
- a sample of breast milk of a lactating mother.
A blood test for staphylococcus aureus (which is taken in the laboratory or in the hospital ward of patients prior to the initiation of antibiotic treatment) involves a subsequent tank sowing its sample on a culture medium with microscopic examination. And for greater accuracy of the definition of an infectious agent, a repeated analysis for staphylococcus is often performed.
Determine the presence of staphylococci in the blood in persistent carriers can be at significantly higher titers of antistaphylococcal serum antibodies detected by two-stage protein precipitation or ELISA.
In severe forms of acne or folliculitis, staphylococcal analysis may be required on the face (a swab from the elements of the rash is taken), and for diffuse furunculosis - to determine the tactics of treatment - dermatologists can prescribe skin analysis for staphylococcus aureus.
How to pass the test for staphylococcus aureus?
Urinalysis, stool analysis for Staphylococcus aureus, as well as analysis of breast milk for staphylococcus are collected in sterilized dry containers with a lid (for milk, two containers - separately for each breast) will be needed.
Preparation for the delivery of stool is to perform the necessary hygienic procedures and stop at least three days after the application of the laxative or probiotic (if any were taken). Two days before the delivery of urine stop taking diuretics.
Can be taken directly in the laboratory: sputum analysis, analysis of throat, throat and nose on staphylococcus. In this case, a smear from the pharynx is done not earlier than 4 hours after eating; Before a smear from a throat two hours do not drink and do not accept food; Before a smear from a nose it or him do not wash out and do not instill in anybody within three hours. And for 10 hours before the delivery of sputum, you should drink a couple of extra glasses of water.
How to take an analysis of staphylococcus a vaginal or a rectal smear is understandable: it is the competence of the examining physician who takes the sampling of the biomaterial and transmits the images to the laboratory, as appropriate.
It is difficult to say exactly how much the staphylococcus is being analyzed: clear instructions on the regulations for microbiological studies of each sample are only available in laboratories.