Bacterial vaginosis (BV) is the most common urogenital disease in women, affecting about 19%-24% of them in reproductive ages annually . BV is defined as a condition characterized by the replacement of the normal vaginal flora with a high numbers of anaerobic, aerobic, and microaerophilic microorganisms. BV can best be described as an “ecological disaster” of the vaginal microflora. The normal flora, which is predominantly composed of lactobacillary morphotypes, is replaced by very high number of mainly aerobic bacteria .
Although at least 50% of infected women have no symptoms, the most common complaints are an abnormal vaginal discharge and a fishy odor, and there is an association with endometritis, increased risk of acquiring STI and preterm birth . The etiology of bacterial vaginosis has not been fully established. The disease mechanism relates to the formation of bacterial biofilms, which are colonies of microorganisms that attach the vaginal epithelium and cover it completely or partially. Such biofilms are often resistant to antibiotic therapy, they raise the pH, and displace endogenous flora . Metronidazole (oral or topical), tinidazole (oral), and clindamycin (oral or topical) are all recommended as initial treatments offering equivalent efficacy. Nevertheless, after treatment, a single recurrence or more may occur in up to 58% of women within 12 months .