Vaginal Redox Potential in Bacterial Vaginosis (Nonspecific Vaginitis)

Abstract

To explore of the association of bacterial vaginosis with anaerobic bacterial growth in the vagina, we measured the redox potential (Eh) at the vaginal epithelial surface of women with this syndrome. Among normal women, the value for Eh in the vagina ranged from +322 mV to +137 mV (mean, +170 mV); whereas among women with bacterial vaginosis, the Eh ranged from +71 mV to as low as -257 mV (mean, -92 mV). Following successful treatment of the vaginosis with metronidazole, the vaginal Eh increased to a mean of +208 mV. Thus, the low redox potential in the vagina during bacterial vaginosis appears to be due to microbial metabolism in the vagina and does not represent a persistent host factor responsible for the anaerobic vaginal flora. Any host factors responsible for bacterial vaginosis remain to be elucidated.

Characterisation and selection of a Lactobacillus species to re-colonise the vagina of women with recurrent bacterial vaginosis

“…Lactic acid and other fatty acids produced by lactobacilli may contribute to the maintenance of a low vaginal pH and a high redox potential, which can inhibit the growth of other bacterial species [27]. The four strains of lactobacilli that demonstrated the most inhibitory activity against BV-associated bacteria were also those that produced the most acidic culture supernate after growth (a mean pH of 3.86 compared with a mean of 4.26 for the values from all 60 isolates).…”

Understanding the Bacterial Flora of the Female Genital Tract

“…A decrease in the number of lactobacilli could result in decreased production of hydrogen peroxide and acid, thereby allowing for unrestricted growth of other constituents of the flora. A shift in the redox potential favoring anaerobic bacterial may in turn contribute to proteolysis, thereby leading to a more alkaline environment [46]. The proteins and amino acids that are released may be metabolized by anaerobic bacteria as a result of the production of amines, which contribute to both the alkalinization of the vaginal environment and the odor problem, and which may also contribute to vaginal irritation [47].…”

Bacterial vaginosis

“…Low pH may directly inhibit some organisms. For every 1.0-U decrease in pH, the oxidationreduction potential increases 60 mV (81). Therefore, low pH may also inhibit anaerobic organisms by maintaining a higher Eh and a less reduced environment.…”

“…Vaginal Redox Potential Holmes et al (81) studied the oxidation-reduction potential (Eh) of the vaginal epithelial surface of women with and without BV to investigate the association of anaerobic bacteria with this syndrome. In BV patients before therapy, the mean Eh was -92 mV (range, 71 to -257 mV) and the mean pH was 5.1 (range, 4.7 to 5.5).…”