Mechanisms Driving Bacterial Community Dynamics in the Human Vagina
Faculty Mentor Information
Kenetta L Nunn (2), Larry J Forney (3)
Abstract
Five community state types have been identified in the vaginal microbiota of reproductive age women. Of these, four are dominated by one Lactobacillus species, namely L. crispatus, L. gasseri, L. iners, and L. jensenii, and these communities encompass 70% of women. The composition of vaginal communities can change over time. With this, we often see changes in the relative abundances of lactobacilli, for example, a community once dominated by L. iners may transition to being dominated by L. crispatus. We posit that changes in the relative abundances of vaginal lactobacilli are driven by competition for resources. Resource competition will be measured in co-culture of the aforementioned Lactobacillus species during exponential phase growth on media containing one carbon source. We will evaluate the outcome of competition in co-culture and compare growth patterns to those observed in vaginal communities. Additionally, we will evaluate growth inhibition between strains on agar and spent media. Preliminary data suggests that the species do not inhibit one another, which supports our hypothesis of resource competition being the main driver of changes in community composition. This research will provide a better understanding of the factors that drive changes in community composition towards states that promote vaginal health.
Mechanisms Driving Bacterial Community Dynamics in the Human Vagina
Five community state types have been identified in the vaginal microbiota of reproductive age women. Of these, four are dominated by one Lactobacillus species, namely L. crispatus, L. gasseri, L. iners, and L. jensenii, and these communities encompass 70% of women. The composition of vaginal communities can change over time. With this, we often see changes in the relative abundances of lactobacilli, for example, a community once dominated by L. iners may transition to being dominated by L. crispatus. We posit that changes in the relative abundances of vaginal lactobacilli are driven by competition for resources. Resource competition will be measured in co-culture of the aforementioned Lactobacillus species during exponential phase growth on media containing one carbon source. We will evaluate the outcome of competition in co-culture and compare growth patterns to those observed in vaginal communities. Additionally, we will evaluate growth inhibition between strains on agar and spent media. Preliminary data suggests that the species do not inhibit one another, which supports our hypothesis of resource competition being the main driver of changes in community composition. This research will provide a better understanding of the factors that drive changes in community composition towards states that promote vaginal health.