PROJECT SUMMARY
The vaginal tract is a harsh, polymicrobial ecosystem that has an active immune response, is rich in
cervicovaginal mucins, and has a robust microbiota. Bacterial persistence within this environment requires the
ability of organisms to adapt to changes in nutrient availability and to interact with the other members of the
microbiota. The vaginal microbiota is classified by five community state types, in which state types I, II, III, and
V are dominated by Lactobacillus species, while community state type IV is marked by increased community
diversity and is loosely termed “dysbiotic”. Our definition of what constitutes vaginal health is evolving; however,
our understanding of the fundamental principles that impact community structure and function, and the role
individual microbes have in community stability is unknown. Determining the interactions that contribute to
persistence within this dynamic environment is challenging, as these are multifactorial in nature. Here, we
propose interdisciplinary approaches to understand the microbial ecology of the vaginal tract and advance our
basic knowledge of vaginal health. Our objective is to determine how the nutritional landscape within the vagina
impacts microbial community assembly, structure, and interactions, that together, contribute to persistent
colonization. We will define metal availability within the vaginal tract and use these data to understand how
changes in the environment shape composition and function of bacterial communities. From this, we will identify
differential importance of bioavailable metals for persistence and expansion of community members. We will
investigate the mechanisms of metal ion homeostasis and determine their impact on cellular metabolism,
cooperation, and competition within microbial communities. We will develop in silica models and validate
mechanisms of metabolic interaction between members of the vaginal microbiota and determine the role of these
interactions in community synergy. Our goal is to define how vaginal ecology drives community interactions and
crosstalk to promote colonization in this complex environment. These findings have the potential to link metal
availability, cellular metabolism, and microbial community structure in vivo. Together, this proposal will use
synthetic vaginal communities to profile the genetic, physiological, and ecological mechanisms that drive
microbial interactions in the vaginal mucosa. These findings will provide a better understanding of the ecological
factors that contribute to vaginal community composition, stability, and interactions. This work will advance our
fundamental knowledge and identify relevant therapeutic targets that could serve to promote efforts in
maintaining vaginal health.