Gardnerella Species and their Association with Bacterial Vaginosis.

ABSTRACT

BACKGROUND: Bacterial vaginosis (BV) is a condition marked by high vaginal bacterial diversity. Gardnerella vaginalis has been implicated in BV but is also detected in healthy women. The Gardnerella genus has been expanded to encompass six validly named species and several genomospecies. We hypothesized that particular Gardnerella species may be more associated with BV. METHODS: Quantitative PCR assays were developed targeting the cpn60 gene of species groups including G. vaginalis, G. piotii/pickettii, G. swidsinskii/greenwoodii and G. leopoldii. These assays were applied to vaginal swabs from individuals with (n=101) and without BV (n=150) attending a sexual health clinic in Seattle, Washington. Weekly swabs were collected from 42 participants for up to 12 weeks. RESULTS: Concentrations and prevalence of each Gardnerella species group were significantly higher in participants with BV. 91.1% of BV positive participants had three or more Gardnerella species groups detected compared to 32.0% of BV negative participants (p<0.0001). BV negative participants with three or more species groups detected were more likely to develop BV within 100 days versus those with fewer (60.5% vs 3.7%, p<0.0001). CONCLUSIONS: These results suggest that BV reflects a state of high Gardnerella species diversity. No Gardnerella species group was a specific marker for BV.