UBC Theses and Dissertations
Metagenomic characterization of the vaginal microbiome Devakandan, Keshini
Background: The vaginal microbiome is a dynamic environment colonized by a wide array of microorganisms. Although bacterial vaginosis (BV) is characterized by a disruption in the normal bacterial microbiome of the vagina, the factors contributing to recurrent BV remain unknown. In addition, very little is known about the role of viruses in the vaginal microbiome and associated dysbioses. Objectives: 1) characterize the vaginal bacteriome of women with recurrent BV using cpn60 sequencing, compare bacterial profiles to healthy-asymptomatic cohort, and correlate profiles to descriptive characteristics; and 2) characterize the vaginal virome of healthy-asymptomatic, HIV-positive women and women with recurrent BV, and correlate profiles to descriptive characteristics. Methods: Twenty-six women were recruited into the recurrent BV bacteriome study. Vaginal swabs were obtained for cpn60 sequencing and Gram stain Nugent scoring. Additionally, samples from 54 women were analyzed in the virome study: 21 healthy-asymptomatic, 25 HIV-positive and eight recurrent BV. The vaginal swabs were processed to enrich for viruses and then subjected to metagenomics shotgun sequencing. Demographic, behavioural and clinical information was collected for all participants, in both bacteriome and virome studies. Results: Bacteriome analyses detected 122 cpn60 operational taxonomic units (OTUs). Bacterial profiles clustered into six community state types (CSTs). Trends suggested a relationship between BV-associated CSTs and number of sexual partners (past year), oral sex, use of (hormonal) contraception, abnormal discharge (past 48 hours), lifetime history of trichomoniasis, and number of BV episodes (past two months and year). Virome analyses detected a total of 477 species. Viral profiles clustered into seven groups. Viral patterns were identified within bacteriome CSTs, Nugent scores, viral loads, between Lactobacillus-dominant, Lactobacillus iners-dominant, and heterogeneous profiles, and were associated with a number of descriptive characteristics. Conclusions: The vaginal microbiome is highly diverse and potentially associated with many clinical factors. Our ability to use the microbiome data to subdivide women into clusters, and detect trends between clusters and characteristics will expand our knowledge on the vaginal microbiome as a whole.
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