Gardnerella vaginalis Clade Distribution Is Associated With Behavioral Practices and Nugent Score in Women Who Have Sex With Women

BACKGROUND: Gardnerella vaginalis is detected in women with and without bacterial vaginosis (BV). Identification of 4 G. vaginalis clades raised the possibility that pathogenic and commensal clades exist. We investigated the association of behavioral practices and Nugent Score with G. vaginalis clade distribution in women who have sex with women (WSW). METHODS: Longitudinal self-collected vaginal specimens were analyzed using established G. vaginalis species-specific and clade-typing polymerase chain reaction assays. Logistic regression assessed factors associated with detection of G. vaginalis clades, and multinomial regression assessed factors associated with number of clades. RESULTS: Clades 1, 2, and 3 and multiclade communities (<2 clades) were associated with Nugent-BV. Clade 1 (odds ratio [OR], 3.36; 95% confidence interval [CI], 1.65-6.84) and multiclade communities (relative risk ratio [RRR], 9.51; 95% CI, 4.36-20.73) were also associated with Lactobacillus-deficient vaginal microbiota. Clade 4 was neither associated with Nugent-BV nor Lactobacillus-deficient microbiota (OR, 1.49; 95% CI, 0.67-3.33). Specific clades were associated with differing behavioral practices. Clade 1 was associated with increasing number of recent sexual partners and smoking, whereas clade 2 was associated with penile-vaginal sex and sharing of sex toys with female partners. CONCLUSIONS: Our results suggest that G. vaginalis clades have varying levels of pathogenicity in WSW, with acquisition occurring through sexual activity. These findings suggest that partner treatment may be an appropriate strategy to improve BV cure.