Multi-omics uncover interactions in the vaginal microbiome and a type II secretion/Tad pilus system in Gardnerella species

A pangenomic split in clinical Gardnerella isolates correlates with high versus low biofilm phenotypes, and clade-specific genomic islands distinguish G. vaginalis from G. piotii via functional gene modules.

• Why it matters: Genetic determinants of vaginal community assembly, biofilm formation, and interspecies interactions are poorly understood, limiting mechanistic links between dysbiosis and adverse outcomes.
• What they did: Long-read whole-genome sequencing produced closed Gardnerella genomes, and integrated 16S rRNA sequencing plus proteomics of all pairwise dual-species co-cultures (five key vaginal bacteria) assessed ecological drivers and asymmetric remodeling.
• The result: A conserved type II secretion/Tad pilus operon is more abundant in BV samples than in healthy controls (93 women), and methyl-{beta}-carboline elevated in Prevotella bivia co-cultures selectively inhibits G. vaginalis and P. bivia while sparing Lactobacillus crispatus.