Prevalence of Sneathia species in mid-vaginal samples. (A) Relative abundance of Sneathia species in mid-vaginal samples. Sneathia was identified by 16S rDNA analysis in 319 of 736 mid-vaginal samples collected from volunteers recruited from outpatient clinics using a 0.1% abundance threshold; i.e., Sneathia was considered present if at least 0.1% of total 16S rRNA reads classified to Sneathia. (B) Abundance of different species of Sneathia (S. sanguinegens, S. amnii, or non-speciated Sneathia) in mid-vaginal samples. The majority of Sneathia reads (76.3%) identified in the mid-vaginal microbiome profiles classify to Sneathia amnii.