Presence of a polymicrobial endometrial biofilm in patients with bacterial vaginosis

Objective: To assess whether the bacterial vaginosis biofilm extends into the upper female genital tract. Study Design: Endometrial samples obtained during curettage and fallopian tube samples obtained during salpingectomy were collected. Endometrial and fallopian tube samples were analyzed for the presence of bacteria with fluorescence-in-situ-hybridisation (FISH) analysis with probes targeting bacterial vaginosis-associated and other bacteria. Results: A structured polymicrobial Gardnerella vaginalis biofilm could be detected in part of the endometrial and fallopian tube specimens. Women with bacterial vaginosis had a 50.0 % (95 % CI 24.0–76.0) risk of presenting with an endometrial Gardnerella vaginalis biofilm. Pregnancy (AOR = 41.5, 95 % CI 5.0–341.9, p,0.001) and the presence of bacterial vaginosis (AOR = 23.2, 95 % CI 2.6–205.9, p,0.001) were highly predictive of the presence of uterine or fallopian bacterial colonisation when compared to non-pregnant women without bacterial vaginosis. Conclusion: Bacterial vaginosis is frequently associated with the presence of a structured polymicrobial Gardnerella vaginalis biofilm attached to the endometrium. This may have major implications for our understanding of the pathogenesis o