Bacterial vaginosis biofilms: a target for therapeutic innovation

Bacterial vaginosis (BV) is one of the most common vaginal microbiome abnormalities worldwide and a risk factor for various obstetric and gynecological complications. Despite years of exploration, existing and quickly emerging clinical, laboratory and instrumental diagnostic methods, and progressive development of science in general, the etiology and pathogenesis of BV remain poorly understood. This is evidenced by the high incidence of chronic and/or recurrent course. There are standard therapeutic approaches aimed to eradicating the causative agent, but the level of efficacy remains questionable due to recurrent episodes. Therefore, further studies of this problem are warranted. Actually, it is evident that G. vaginalis forms polymicrobial biofilms on urogenital tract mucosa. Biofilms represent associations of microorganisms that are adhered to the surface of the epithelium and connected together in the polymer matrix. Biofilms change the properties of the microorganisms involved into their structural frame and provide beneficial conditions for their interactions. This results in the increase of the existing pathogenic properties of bacteria associated with BV, as well as in the appearance of new features. Thus, the microorganisms become less susceptible to previously effective antibiotics and to aggressive media. Finally, this contributes to the recurrent course of the disease. In most cases, treatment of BV is based on the immediate effect on the microorganisms, but in patients with confirmed biofilm-associated BV this strategy is not effective and is associated with BV recurrences. Thus, currently relevant issues include exploration of the causes of recurrent BV, development of anti-biofilm agents able to disrupt their matrix and release bacteria from their carcass, and introduction of these agents into clinical practice. This will increase the effectiveness of treatment.