Causes of violation of the vaginal microflora

Inflammatory diseases of female genital organs occupy the first place (55-70%) in the structure of gynecological incidence. A significant proportion of them are occupied by infections of the vulva, vagina and cervix. In women of reproductive age, vaginitis develops due to bacterial infection (40-50%), vulvovaginal candidiasis (20-25%) and trichomoniasis (10-15%).

All inflammatory processes of the genitals are divided into nonspecific and caused by sexually transmitted infections.

The study of the vaginal discharge plays an important role in the diagnosis of inflammatory diseases of the lower genital tract. Common signs of the inflammatory process are the appearance of leukocytes (neutrophils and eosinophils), lymphoid elements and macrophages.

Nonspecific vaginitis - infectious and inflammatory diseases of the vagina, conditioned by opportunistic microorganisms (E. Coli, streptococci, staphylococcus, etc.). With nonspecific vaginitis, smears show a large number of white blood cells (30-60 or more in the field of vision), there are no key cells, but many cells of the ejaculated vaginal epithelium. As a rule, several species of microorganisms are found. In general, the microscopic picture is typical for inflammatory exudates.

Bacterial vaginosis is a nonspecific (similar to inflammatory) process, in which vaginal discharge is not detected pathogenic pathogens (it accounts for 40-50% of all infectious vaginitis). Currently, bacterial vaginosis is considered as a dysbacteriosis of the vagina, which is based on a violation of microbiocenosis.

The most informative laboratory method for diagnosing bacterial vaginosis is the detection in key strokes stained with Gram, the key cells (slipped vaginal cells covered with a large number of small gram-negative bacteria). These cells reveal in 94,2% of patients, while in healthy women they are absent. The most objective way of identifying key cells is to study the cellular margins of the epithelium. The key are the epithelial cells, the edges of which are blurred, indistinct due to the attachment of bacteria to them. In addition to key cells, bacterial vaginosis in microscopy with saline is indicated by the presence of small bacteria in the absence of lactobacilli.

The number of different optional ( Gardnerella vaginalis ) and anaerobic (bacteroids) bacteria in bacterial vaginosis is higher than in healthy women. In fact, the total content of bacteria in the vagina increases to 10 ¹¹ in 1 ml. Unlike patients with normal microflora, in patients with bacterial vaginosis, not facultative, but anaerobic lactobacilli predominate. Reducing the number of facultative lactobacilli leads to a decrease in the formation of lactic acid and an increase in pH. In patients with bacterial vaginosis, the pH of the vagina is in the range of 5-7.5.

Gardnerella vaginalis (found in 71-92% of patients, is more than 5% of all microflora) and other anaerobes contribute to the intensification of the processes of rejection of epithelial cells, especially under alkaline conditions, which leads to the formation of pathognomonic key cells.

Due to the increase in the number of facultative anaerobes in bacterial vaginosis, the production of abnormal amines increases. Amines with increasing vaginal pH become volatile, causing a typical "fishy smell" of the vaginal discharge. For its detection, an amino test is performed in the laboratory (a specific smell appears when a 10% solution of potassium hydroxide is added to the drop of the vaginal secretion).

When Gram stain smears in patients with bacterial vaginosis, less than 5 lactobacilli and more than 5 gardnerella or other microorganisms are found in the immersion field. The presence of a large number of white blood cells in smears from the vagina is not considered characteristic of bacterial vaginosis.

The criteria for diagnosing bacterial vaginosis are as follows.

• Positive amino test.
• The pH of the vaginal discharge is> 4.5.
• Key cells in smears stained by Gram.

Trichomoniasis refers to the specific inflammatory diseases of female genital organs (it accounts for 15-20% of all infectious vaginitis). Diagnosis of trichomoniasis is based on the bacterioscopic detection of vaginal trichomonads after stain smearing by Gram, Romanovsky-Giemsa, methylene blue, or in native preparations (for trichomonads, the oval or rounded shape, the presence of flagella and jerky movements are characteristic). Permanent identification morphological signs of vaginal trichomonads in smears - a characteristic, intensely colored, eccentrically located nucleus and a gently-cellular cytoplasm. It should be noted that it is not always possible to detect trichomonads at a microscopic examination (the sensitivity of the method is 40-80%). Therefore, it is necessary to take the material for study again. In connection with the inflammatory process, smears show epithelial cells of various sizes, cells with an enlarged nucleus, binuclear cell elements, foci of leukocytes in the form of a "cannonball" on the surface of the flat epithelium. The best results are the viewing of the native preparation in a microscope with a dark-field capacitor, since in this case single and sluggish individuals are found in clusters of cellular elements due to the clearly visible movement of the flagella. In the study of native drugs, one should remember the possibility of detection, especially in the urine, of the flagellate protozoan family of bodonides. Unlike trichomonads, they are smaller in size and have only 2 flagella, which causes their rapid forward movement in a straight line. When examining stained smears, errors are possible, since epithelial cells can be taken for trichomonads.

Clinical follow-up with the study of urine and vaginal discharge in women who have had trichomoniasis should be performed for at least two menstrual cycles.

Gonorrhea. In the study of vaginal smears for gonorrhea, the intracellular location of gonococci (in leukocytes), their bean-shaped form and negative Gram staining are characteristic.

Candidiasis of the genitals cause yeast-like fungi of the genus Candida (it accounts for 20-25% of all infectious vaginitis). To diagnose candidiasis, microscopic examination of the material taken from the lesion is performed (sensitivity of the method is 40-60%). With candidiasis of the genitals in an acute period of the disease, lactobacilli in the vaginal discharge are detected in an insignificant amount (on average - 16.6% of the whole microflora) or they are absent altogether. In 75% of patients the pH of the vagina is within 5-5.5, which is considered very informative for the diagnosis of candidiasis. The presence of mycelium and spores in wet smears treated with a 10% solution of potassium hydroxide confirms the diagnosis.

Results of the study of vaginal discharge in various diseases

Results of the study	Bacterial vaginosis	Trichomoniasis	Candidiasis
PH	> 4.5	> 4.5	4.0-4.5
Microscopy of moist preparation (separated from the lateral wall of the vagina, diluted in 0.9% solution of sodium chloride)	Key Cells	Movable flagellated protozoa (found in 40-80% of cases)	Pseudohyfy (found in 40-60%)
Microscopy of a smear stained by Gram (detachable from the lateral wall of the vagina)	Key Cells		Spores / pseudo-hyphae (found in 40-60% of cases)
Amino test	Positive	Usually positive	Negative

[1], [2], [3], [4]