Döderlein bacteria

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Döderlein bacteria (narrow rods ) and cytolytic vaginal epithelial cells

As Doederlein bacteria or Doederlein chopsticks referred to those lactic acid bacteria that normally the vagina (sheath) of the women in the childbearing age colonize . They are named after the German gynecologist Albert Döderlein (1860–1941).

The Döderlein flora consists of a heterogeneous group of gram-positive rod bacteria that produce lactic acid .

The squamous epithelium of the vagina changes cyclically from sexual maturity under the influence of estrogen . As a result, it proliferates and stores more glycogen . During normal exfoliation by the action of the gestagens, the lactobacilli decompose the glycogen and lactic acid is formed. This creates the physiologically acidic environment (pH 4), which prevents pathogenic germs from growing. Lactobacilli can be detected shortly after birth (estrogen influence of the mother) and only after the menarche ; in the intervening period, the vaginal pH is alkaline.

For a long time it was assumed that Lactobacillus acidophilus was the most common microorganism in the vaginal flora , but it has now emerged that the most common vaginal inhabitant is Lactobacillus iners , followed by Lactobacillus crispatus (depending on the study, the other way around). Other common types of lactobacillus found in the vagina are:

Lactobacillus species are sensitive to most broad-spectrum antibiotics, so treatment with an antibiotic can damage the vaginal flora. There is no sensitivity to fluoroquinolones and nitroimidazoles .

Physiology of the vaginal flora

View of the front third of a human vagina , starting from the introitus vaginae , the vaginal entrance with the rugae vaginales and the reflective vaginal epithelium with the vaginal flora

As representatives of the lactic acid bacteria or Lactobacillaceae , Lactobacillus species grow anaerobically , but aerotolerant, i.e. that is, they grow in the presence of atmospheric oxygen, but do not need oxygen for their metabolism . The same goes for the vaginal gram-positive anaerobes - they are pleomorphic , they appear as rods or cocci.

The decisive mechanism that prevents pathogenic germs from overgrowing the vaginal surface ( dysbiosis ) is the milieu created indirectly by the cyclically acting estrogens . Under its hormonal influence, glycogen is formed in the squamous epithelia of the vaginal mucosa. This in turn is metabolized by the lactobacilli to lactic acid ( lactate ), which lowers the pH value to the acidic range (around pH 3.8 to 4.4). But not only the lowering of the pH value is caused by the "Döderlein bacteria group", they also cause the cytolysis of the exfoliating surface epithelial cells and the release of sugars and the formation of lactic acid from dextrose and maltose . Since the occurrence of lactobacteria is estrogen-dependent, their concentration is reduced in childhood and after the menopause .

But not only the low pH value as such affects the vaginal microbiome, but also the supply of nitric oxide (NO) - a gasotransmitter with bactericidal and virucidal effect - which fragments the cell membranes of bacteria and the protein envelopes of viruses, made possible by the acidic environment .

Publications

Individual evidence

  1. ↑ Axel Kramer, D. Gröschel, P. Heeg, V. Hingst, Hans Lippert , M. Rotter, W. Weuffen: Clinical Antiseptics. Springer-Verlag, Heidelberg / Berlin / New York 2013, ISBN 3-6427-7715-5 , pp. 193–194
  2. ↑ Hill, JE et al. (2005): Characterization of vaginal microflora of healthy, nonpregnant women by chaperonin-60 sequence-based methods. In: Am J Obstet Gynecol. Vol. 193, pp. 682-92. PMID 16150261
  3. ↑ Verhelst, R. et al. (2005): Comparison between Gram stain and culture for the characterization of vaginal microflora: definition of a distinct grade that resembles grade I microflora and revised categorization of grade I microflora. In: BMC Microbiol. Vol. 5, p. 61. PMID 16225680
  4. ↑ Nam, H. et al. (2007): Analysis of vaginal lactic acid producing bacteria in healthy women. In: J Microbiol. Vol. 45, pp. 515-520. PMID 18176534
  5. ↑ Elke Wolf: Vaginal flora in an uproar. Pharmaceutical newspaper, online edition 36/2009
  6. ↑ Albert Döderlein was a lecturer at the University of Munich , but medicine can also be studied in Munich at the Technical University of Munich .