182: Restoration of the vaginal microbiome & Its ecology following obstetrical fistula repair in Lilongwe, Malawi

Abstract

The vaginal microbiome is a key mediator of reproductive health and disease, and fluctuations in its ecology and dysbiosis as a result of pregnancy and infection/antibiotics are well known. However, community restoration following major disruptive events have not been studied. We hypothesized that characterizing the vaginal microbiome community restoration following surgical repair of chronic obstetrical fistula would be unique and highly informative. Following Malawi IRB approval, n=15 women undergoing delayed repair of their obstetrical VVF or RVF consented for participation in this observational, prospective cohort arising from the Fistula Care Centre (Bwaila Hospital, Lilongwe, Malawi). Detailed surgical, medical, dietary & other metadata were collected alongside daily vaginal, urine & rectal microbiome specimens (CatchAll swabs) from pre-op (d0) through discharge (d9-28) & at 6 weeks post-operative and stored in sterile SCF-1 media. For metagenomics, DNA was extracted in a BSL2 hood with parallel “contaminant” controls & subjected to 16S V4 & shotgun metagenomic sequencing (Illumina). Customized bioinformatics pipelines were developed for longitudinal microbiome community assessment. There are several key and novel findings. 1) Following obstetric fistula repair, the vaginal community was restored and differentiated from the body site communities (Fig.1A); 2) Each woman demonstrated near daily changes in her vaginal ecology, being more similar to herself than to others (Figs.1B-2); 3) Community microbial dynamics were shaped by several keystone genera, including lactobacilli and bifidobacteria (Fig.2C); 4) All women with a successful fistula repair demonstrated microbial restoration within 6 weeks, despite months to years of symptomatic VF. We report for the first time restorative vaginal community ecology in n=15 subjects undergoing delayed obstetrical fistula repair. While larger cohorts are needed to understand potential microbial predictors of successful obstetrical VF repair, these findings illustrate the remarkable resilience of the vaginal microbiome.