Event

M.S. Dissertation Defense Announcement: Elizabeth Everich

Monday, November 16, 2026
1:00 p.m.
AJC 5104 (5th floor conference room)
Debbie Chu
301 405 8268
dgchu@umd.edu

Title: Assessing the impact of intravaginal phthalates on the cervicovaginal microenvironment

Committee members:
Dr. Hannah Zierden, Chair
Dr. Akua Asa-Awuku
Dr. Sara Molinari

Abstract:
The composition of the vaginal microbiome is a driver of female reproductive health. The vaginal microbiome plays a key role in preventing acquisition of female reproductive tract diseases such as sexually transmitted, yeast, and urinary tract infections. In a healthy state, the microbiome is dominated by Lactobacillus species, which produce bactericidal agents that protect the vaginal environment from pathogens. These bacteria work together with the underlying cervicovaginal mucosal layer that serves as a physical barrier for foreign material. Disruption of this environment through the colonization of pathogenic microbes leads to vaginal dysbiosis, increasing risk of disease acquisition. Dysbiosis has been associated with environmental factors, sexual practices, and stress; however, the mechanisms that promote dysbiosis remain poorly understood. 

This work hypothesizes that local vaginal exposure to endocrine disrupting chemicals contributes to the onset of dysbiosis. Phthalates are endocrine disrupting chemicals that leach from plastic products and disrupt hormone signaling. These chemicals are of particular concern given higher levels are observed in women, likely due to their prevalence in feminine hygiene products. Phthalate exposure has been linked to adverse reproductive outcomes, but existing studies have focused on systemic exposure, leaving intravaginal exposure unexplored. This work examines the effects of a physiologically relevant phthalate mixture on the function of the vaginal microbiome and barrier properties of cervicovaginal mucus. Growth of planktonic and biofilm cultures of model vaginal species, commensal Lactobacillus crispatus and dysbiotic Gardnerella vaginalis, were not altered by phthalate exposure. However, total RNAseq revealed functional changes in L. crispatus, suggesting phthalates may modulate commensal activity. Multiple particle tracking was used to probe cervicovaginal mucus barrier properties, resulting in participant-dependent trends. These findings provide a mechanistic framework for understanding reproductive pathophysiology and help identify modifiable exposures that improve female reproductive health.