Table of contents:

1. The vaginal ecosystem
2. Bacterial flora of the vagina (vaginal biocenosis)
3. Development of the vaginal microflora

Vaginal ecosystem

Comprises all the micro-organisms, and the products of their metabolism, residing in this anatomical area, linked to each other by various relationships and maintained in a specific quantitative and qualitative ratio, as well as other elements such as exfoliated vaginal epithelial cells, sebaceous secretions, Bartholin gland secretions and others.

The basis for the proper functioning of the female genital tract is first and foremost the maintenance of its physiological microflora, the composition of which depends on many factors both from outside and inside the body, as well as on the anatomical area in which it occurs. Thus, the microflora of the vulva and perineal area is different, that of the vagina is different and that of the cervix is different.

It is of the greatest importance to maintain a normal vaginal microflora, due to the fact that it is the connection between the external and internal parts of the reproductive organs, and is also the most susceptible to infection, as its warm and moist environment provides an excellent breeding ground for pathogenic microorganisms.

The bacterial flora of the vagina (vaginal biocenosis)

May contain a mixture of micro-organisms from different sites of the reproductive organs. It is made up of both aerobic and anaerobic nonpathogenic microorganisms, as well as those showing pathogenic properties. Maintaining the right balance between them ensures that the correct ph is maintained and thus provides a protective barrier against infection.

The bacterial flora of the vagina is very sensitive to many factors, under the influence of which its balance can be easily disturbed. It exhibits a high degree of individual quantitative and qualitative variability. Disturbance of the balance between bacteria living permanently in the vagina (commensal bacteria) may lead to excessive multiplication of one of the strains of a given microorganism, becoming the aetiological factor of inflammation.

The state of the physiological vaginal microflora may be affected:

• the general state of the organism,
• the degree of immunity,
• hormonal balance,
• phase of the sexual cycle,
• age,
• systemic diseases e.g. diabetes, thyroid diseases,
• number of sexual partners,
• personal hygiene,
• sexual hygiene,
• nutrition (diet high in carbohydrates and sugar),
• medication taken (antibiotics, oral contraceptives, immunosuppressants),
• clothing.

In a healthy woman of childbearing age, the vaginal bacterial flora is dominated by Lactobacillus bacteria (lactic acid bacilli). These bacilli are Gram-positive bacteria, also known as Döderlein bacilli, which are responsible for maintaining the balance of the vaginal microenvironment and significantly reduce the risk of invasion by pathogenic microorganisms.

They cover the vaginal epithelium, which is strictly rich in carbohydrates - essential for fermentation processes - and produce substances such as hydrogen peroxide (hydrogen peroxide), ensuring: maintenance of an acidic vaginal environment - with a ph of less than 4.5 -, stimulation of the immune system and inhibition of the multiplication and spread of pathogenic bacteria. The reduction or loss of Lactobacillus, under the influence of complex changes in the vaginal environment, leads to a disruption of the vaginal biocenosis and excessive growth of microorganisms, especially anaerobic ones, resulting in the appearance of infection exponents.

Thevaginal ecosystem and its imbalance, photo: panthermedia

Gardnerella Vaginalis, Mycoplasma genitalium, Mykoplasma hominis and Ureaplasma urealyticum proliferate most frequently. Due to the rapid regeneration of lactic acid bacilli, the vaginal bacterial flora often returns spontaneously to its physiological state. However, it should be noted that the regeneration of lactic acid bacteria takes much longer than the proliferation of other bacteria, making the return to balance in the vaginal ecosystem quite difficult and lengthy.

Development of the vaginal microflora

Is mainly stimulated by oestrogens. In foetal life, the vagina of the female foetus is sterile. Despite the fact that the ovaries of girls do not produce oestrogens until puberty, acid-forming bacilli can be found in the vaginal secretions of the female newborn until 3 weeks of age. This is due to the fact that after birth, the newborn remains under the influence of the mother's oestrogens due to the passage of these hormones through the placental barrier. Until about 10 years of age, girls are in a so-called hormonal quiescence period. Their ovaries do not produce the sex hormones that stimulate the development of Döderlein bacilli, so the vaginal environment at this age is alkaline. A similar situation occurs in the postmenopausal period.

Due to the cessation of ovarian function and the decrease in oestrogen secretion, the number of lactic acid bacilli decreases and they disappear, resulting in a change in the vaginal reaction from acidic to alkaline. Because the vaginal epithelium reacts very quickly to fluctuations in the concentrations of oestrogen hormones, these two age groups are particularly susceptible to disorders of the vaginal microflora.

The susceptibility of the vaginal biocenosis to all external and internal factors that may lead to the elimination or reduction of lactic acid bacilli, and thus to an increased risk of invasion by pathogenic microorganisms and the appearance of symptoms of infection, is why women most frequently visit gynaecological surgeries with these complaints. Disorders of the normal vaginal biocenosis often occur during pregnancy, in the post-partum period, as a result of natural ageing or as a result of surgical procedures performed on the vagina or on the cervix or its cavity.

In addition to hormonal disorders, the normal vaginal microflora may be disturbed by various pathological conditions of the genital organs, systemic diseases, e.g. diabetes mellitus, liver disease, anaemia, avitaminosis, hormonal medication or antibiotic therapy. Excessive sexual activity, as well as incorrect hygiene habits, such as frequent vaginal irrigation, the use of soaps and intimate hygiene products or the use of vaginal tampons, can also disturb the natural environment in the vagina.

In vaginal secretions, the most common microorganisms are:

• Lactobacilli - Lactobacillus vaginalis,
• Streptococci -- Streptococci -- S. agalactiae, the typical species is S. pyogenes (purulent streptococcus ), which can cause generalised infection,
• Enterococci -- Enterococcus faecalis, Streptococcus faecalis (faecal streptococci ) - commensal bacteria (resident in the vagina), can be virulent under certain conditions,
• Staphylococci- belong to the family Micrococcaceae - commensal bacteria of the skin and mucousmembranes , if found in clusters they are calledStaphylococci, in the vagina the most common are S. aureus (Staphylococcus aureus ) and S. epidermidis (Staphylococcus cutis ),
• Comma - Vibrio - a major alkaliser of the vaginal environment, sometimes can be pathogenic,
• Spirochaetebacteria - Spirochaetaceae -, the most common genus in the vagina is Borrelia,
• Gonococcus - Neisseria gonorrhoeae (gonorrhoeae ),
• Escherichia coli - belongs to the Enterobacteriaceae family ,
• Common daphnia - Proteus vulgaris - belongs to the Enterobacteriaceae family, commensal bacterium, can be pathogenic under certain conditions,
• Corynebacteriaceae - Corynebacteriaccae - rarely pathogenic(C. Pseudodiphteriticum, C. xerosis),
• Enterobacter - belongs to the Enterobacteriaceae family , the most common genus in the vagina is E. cloacaae, can be pathogenic under favourable conditions,
• Pneumoniabacillus - Klebsiella pneumoniae - causes infection of the female genital tract,
• Pseudomonas bac illi - P. aeruginosa is pathogenic, it is a low-grade bacterium but difficult to treat if infected,
• Vaginal bacillus - Gardnerella vaginalis - causes bacterial vaginitis (so-called bacterial vaginosis),
• Yeasts - Candida albicans, C. pseudotropicalis and others - cause fungal infections,
• Protozoa - Trichomonas vaginalis (vaginal cilia) - causes cystic genital infections,
• Mycoplasmas - Mycoplasma hominis, Ureaplazma urealyticum - microorganisms that are commonly found in the vagina of sexually active women, they can be a component of the normal vaginal biocenosis, but under favourable conditions they exhibit pathogenic properties.

The composition of the vaginal bacterial flora is different in every woman and undergoes constant changes during the sexual cycle. In most cases, bacterioscopic evaluation of vaginal secretions makes it possible to differentiate vaginal biocenosis disorders in approximately 90 per cent of cases, but in the case of mixed infections (bacterial, viral, fungal), for example, it is necessary to carry out more detailed diagnostic tests targeting the microorganism suspected of causing the infection. In order to make a correct diagnosis of the infection, in addition to the results of diagnostic tests, it is necessary to take a detailed history, analyse the complaints and the symptoms present.