Investigating Bacterial Vaginosis Pathogenesis Using Peptide Nucleic Acid-Fluorescence Hybridization With a Focus on the Roles of Species, , and .

BACKGROUND

Bacterial vaginosis (BV) is a vaginal dysbiosis characterized by polymicrobial communities of BV-associated bacteria (BVAB) adhered to the vaginal epithelium. Despite decades of research, its etiology remains unknown. We aimed to investigate BV biofilm formation over time among women who developed incident BV (iBV) using peptide nucleic acid-fluorescence hybridization (PNA-FISH), focusing on 3 key BVAB ( species, , and ).

METHODS

Heterosexual, nonpregnant women ages 18-45 with optimal vaginal microbiota were enrolled to self-collect twice-daily vaginal specimens for 60 days. iBV was defined as a Nugent score of 7-10 on ≥4 consecutive specimens. For women who developed iBV (cases), spp., , and were visualized and quantified by PNA-FISH for up to 14 days prior to iBV, the day of iBV, and 3 days post-iBV. Cases were matched to women maintaining optimal vaginal microbiota (controls) based on age, race, and contraceptive method. Control specimens were matched to case specimens by day of menses.

RESULTS

Among 135 women enrolled, 18 developed iBV and were matched to 18 controls. Pooled median spp. counts significantly increased starting 5 days before iBV, while pooled median counts significantly increased on the day of iBV diagnosis. In contrast, pooled median counts were not significantly different between groups.

CONCLUSIONS

These data suggest that spp. are early colonizers of the BV biofilm while is a secondary colonizer. was not found to be significantly different between iBV case and control specimens.