Metabolic network models of Gardnerella pangenome identify interactions in the vaginal environment

Abstract

Gardnerella is the primary pathogenic bacterial genus present in the polymicrobial infection known as bacterial vaginosis (BV). Despite BVs high prevalence and associated chronic and acute womens health impacts, the Gardnerella pangenome is largely uncharacterized at both the genetic and functional metabolic level. Here, we used genome scale metabolic models to characterize in silico the Gardnerella pangenome metabolic content and assessed metabolic functional capacity within a BV positive cervicovaginal fluid context. Metabolic capacity varied widely across the pangenome, with 38.15% of all reactions as core to the genus, compared to 49.6% of reactions identified as unique to a smaller subset of species. Four genes - gpsA, fas, suhB, psd - were identified as core essential genes, critical for in silico metabolic function of all analyzed bacterial species in the Gardnerella genus. Further understanding of these core essential metabolic functions could inform novel therapeutic strategies to treat BV. These data represent the first metabolic modelling of the Gardnerella pangenome and illustrate strain-specific interactions with the vaginal metabolic environment across the pangenome.