Vaginal microbiome and sexually transmitted infections: an epidemiologic perspective

Abstract

Vaginal bacterial communities are thought to help prevent sexually transmitted infections. Bacterial vaginosis (BV) is a common clinical syndrome in which the protective lactic acid-producing bacteria (mainly species of the Lactobacillus genus) are supplanted by a diverse array of anaerobic bacteria. Epidemiologically, BV has been shown to be an independent risk factor for adverse outcomes including preterm birth, development of pelvic inflammatory disease, and acquisition of sexually transmitted infections. Longitudinal studies of the vaginal microbiome using molecular techniques such as 16S ribosomal DNA analysis may lead to interventions that shift the vaginal microbiota toward more protective states.

Figure 1. Heat map showing the distribution of microbial taxa found in the vaginal microbial communities of 394 reproductive-age women.

(A) Complete linkage clustering of samples based on species composition and abundance in communities. (B) Nugent scores and pH measurements for each of the 394 samples. (C) Shannon diversity indices calculated for each of the 394 vaginal communities (two singletons were excluded). Adapted with permission from Proceedings of the National Academy of Sciences of the United States of America (30).

Figure 2. Rapid fluctuation of Nugent Gram stain score in 4 women who self collected vaginal swabs twice weekly for 16 weeks.

Adapted with permission from Sexually Transmitted Infections (61).