Prevotella and Gardnerella Are Associated With Treatment Failure Following First-line Antibiotics for Bacterial Vaginosis

Abstract

Background: Bacterial vaginosis (BV) is a common vaginal dysbiosis that often recurs following first-line antibiotics. We investigated if vaginal microbiota composition was associated with BV recurrence.

Methods: We analyzed samples and data from 121 women who participated in 3 published trials evaluating novel interventions for improving BV cure, including concurrent antibiotic treatment of regular sexual partners (RSPs). Women diagnosed with BV received first-line antibiotics and self-collected vaginal swabs pretreatment and the day after finishing antibiotics (immediately posttreatment). 16S rRNA gene sequencing was performed on vaginal samples. Logistic regression explored associations between BV recurrence and features of the vaginal microbiota pre- and posttreatment.

Results: Sixteen women (13% [95% confidence interval {CI}, 8%-21%]) experienced BV recurrence within 1 month of treatment. Women with an untreated RSP were more likely to experience recurrence than women with no RSP (P = .008) or an RSP who received treatment (P = .011). A higher abundance of Prevotella pretreatment (adjusted odds ratio [AOR], 1.35 [95% CI, 1.05-1.91]) and Gardnerella immediately posttreatment (AOR, 1.23 [95% CI, 1.03-1.49]) were associated with increased odds of BV recurrence.

Conclusions: Having specific Prevotella spp prior to recommended treatment and persistence of Gardnerella immediately posttreatment may contribute to the high rates of BV recurrence. Interventions that target these taxa are likely required to achieve sustained BV cure.

Keywords: Gardnerella; Prevotella; bacterial vaginosis; regular sexual partner; vaginal microbiota.

Figure 1.

Diversity metrics of the vaginal microbiota of women who experienced bacterial vaginosis recurrence and those that remained cured at 1 month postenrollment. Nonmetric multidimensional scaling plots of the overall composition of the vaginal microbiota pretreatment (A) and immediately posttreatment (B). Box plots showing the bacterial diversity (measured using the Shannon diversity index) of the vaginal microbiota of cure and recurrence cases pretreatment and immediately posttreatment (C). Box plots displaying differences in the compositional change of the vaginal microbiota following treatment (measured using Bray–Curtis distances calculated between paired pretreatment and immediate posttreatment samples) between cure and recurrence cases (D). Abbreviations: ANOSIM, analysis of similarity; NMDS, nonmetric multidimensional scaling.