Impact of pH and Mycoplasma hominis endosymbiosis on Trichomonas vaginalis pathogenesis

Abstract

Significance Trichomonas vaginalis is a human urogenital parasite responsible for the sexually transmitted infection trichomoniasis and relies on adherence to and lysis of vaginal epithelial cells to promote infection. This study reveals that vaginal acidity and symbiosis with the bacteria Mycoplasma hominis likely reprograms T. vaginalis virulence through induction of increased abundance of several parasite surface proteins. One acts through a calcium-dependent mechanism to enhance host:parasite interaction and another, a surface lectin, specifically binds glycans and couples this to host cell metabolic activation. This work provides a mechanistic framework for understanding how environmental conditions and a bacterial symbiont amplify the risk of infection and identifies parasite adhesins that provide insight into potential therapeutic strategies.