Can cooperation within the vaginal microbiome lead to the development of bacterial vaginosis?

Abstract

[Excerpt] Despite being a controversial topic over the past few decades, Gardnerella vaginalis has been attributed a central role in bacterial vaginosis (BV) development. An important milestone in BV research was the discovery that the different species involved in BV were associated in a structured polymicrobial biofilm, dominated by G. vaginalis. Subsequent studies demonstrated that G. vaginalis biofilms display a high resistance to the protective mechanisms of normal vaginal microflora, as well as an increased tolerance to antibiotics. Despite the increased evidence of the pivotal role of G. vaginalis in BV biofilm development, the importance of the other BV-associated anaerobes should not be neglected. There are some observational studies that correlate bacterial co-colonization between G. vaginalis and some other specific BV-associated bacteria during BV. Furthermore, synergistic interactions can occur between BV-associated species and G. vaginalis, leading to increased biofilm formation in dual-species biofilms. We hypothesized that differential bacterial interactions can occur during BV development. To test our hypothesis, we examined the ecological interactions between G. vaginalis and other 15 BV-associated anaerobes that we had previously shown to enhance biofilm formation by G. vaginalis, using a dual-species biofilm model. [...]