Grant: Travel Awards - Institute Community Support

Staphylococcus aureus is an opportunistic pathogen that colonizes approximately one-third of the human population and is capable of causing a wide spectrum of diseases. In the vaginal tract of cisgender women, its role has traditionally been associated with menstrual toxic shock syndrome (mTSS), a life-threatening infection linked to the use of menstrual-management devices such as tampons. mTSS results primarily from the production of toxic shock syndrome toxin-1 (TSST-1), whose expression is tightly regulated by vaginal environmental conditions and by interactions with the dominant members of the vaginal microbiota. Our previous studies revealed that TSST-1 production occurs only at specific points during the menstrual cycle, creating a narrow window of opportunity for mTSS to develop. Although mTSS represents the most acute manifestation of vaginal S. aureus infection, our more recent work demonstrates that the bacterium also contributes to vaginitis. Using a BALB/c mouse model, we showed that TSST-1 production triggers local inflammation and alters the composition of vaginal microbial communities, in a manner dependent on the activity of CD8+ T cells. Together, these findings indicate that S. aureus and TSST-1 drive broader disruptions of the vaginal ecosystem beyond mTSS. Understanding virulence expression and controlling inflammation-prone bacteria such as S. aureus is therefore a critical determinant of women's health, with implications for infection prevention, reproductive outcomes, and fertility.