Results: We constructed the Vaginal 16S rDNA Reference Database, a comprehensive and non-redundant database
of 16S rDNA reference sequences for bacterial taxa likely to be associated with vaginal health, and we developed
STIRRUPS, a new method that employs the USEARCH algorithm with a curated reference database for rapid
species-level classification of 16S rDNA partial sequences. The method was applied to two datasets of V1-V3 16S
rDNA reads: one generated from a mock community containing DNA from six bacterial strains associated with
vaginal health, and a second generated from over 1,000 mid-vaginal samples collected as part of the Vaginal
Human Microbiome Project at Virginia Commonwealth University. In both datasets, STIRRUPS, used in conjunction
with the Vaginal 16S rDNA Reference Database, classified more than 95% of processed reads to a species-level
taxon using a 97% global identity threshold for assignment.