The Role of Gardnerella and Prevotella Species as Early Colonizers in the Pathogenesis of Incident Bacterial Vaginosis - PROJECT SUMMARY/ABSTRACT The purpose of this NIH/NIAID F31 fellowship proposal is to provide support for the PI, Sheridan George, BS for mentored research and career development within her University of Alabama at Birmingham (UAB) Microbiology PhD graduate training program to enhance her potential for a successful career in medical microbiology, public health, and translational research. The training plan will address three main areas of focus: [1] mastery of advanced laboratory techniques (i.e., qPCR, cell culture, hemolysis assays, ELISA), [2] enhance skills in data analysis and biostatistics, and [3] develop skillsets relevant to performing translational/clinical research. The overall goal of this training plan is to provide the PI with a solid foundation to transition into an independent translational researcher. The primary objective of this F31 is to investigate key bacterial species that play a role in incident bacterial vaginosis (iBV). Despite over 70 years of research, the etiology of BV remains unknown; however, two genera, Gardnerella and Prevotella, are hypothesized to be early colonizers of the BV biofilm. Additionally, multiple studies have proposed a synergistic relationship between Gardnerella and Prevotella species during BV biofilm formation through the production and uptake of amino acids and ammonia. In our parent R01 study, longitudinal vaginal specimens were collected from women who developed iBV (cases; n=18) and women who maintained optimal vaginal microbiota (non-cases; n=18). Preliminary data using these vaginal specimens demonstrated a significant abundance of Gardnerella spp. in iBV cases compared to non-cases, starting 5 days before iBV through 3 days post-iBV, and an overall absence of Prevotella bivia in cases and non-cases. These results emphasize the importance of investigating the roles of the recently expanded Gardnerella genus and other Prevotella spp. beyond P. bivia during in iBV pathogenesis. In Aim 1, the PI will perform qPCR to determine the abundance of Gardnerella (G. greenwoodii, G. leopoldii, G. piotii, G. pickettii, G. swidsinskii, G. vaginalis) (Aim 1A) and Prevotella spp. (P. amnii, P. bivia, P. disiens, P. timonensis) (Aim 1B) within vaginal specimens from iBV cases and non-cases from seven days prior to iBV to the day of iBV diagnosis. In Aim 2, isolates of both Gardnerella and Prevotella spp. will be cultured individually (Aim 2A) and co-cultured (Aim 2B) on vaginal epithelial cells (VK2 cells) to investigate virulence mechanisms and the potential for synergistic relationships that contribute to iBV pathogenesis. The long-term goal of this project is to better understand the roles of select early bacterial colonizers and trigger(s) of the BV biofilm, which will inform improvements in BV diagnosis, treatment, and prevention. The PI’s primary research project mentor, Dr. Christina Muzny, and co-mentor, Dr. Megan Amerson-Brown, have been working closely with the PI throughout her graduate school career and endorse the proposed training plan and research activities.
