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The diversity and dominant bacterial taxa in the vagina are reported to be influenced by multiple intrinsic and extrinsic factors, including but not limited to pregnancy, contraceptive use, pathogenic states, socioeconomic status, and ancestry. However, the extent to which host genetic factors influence variation in the vaginal microbiota is unclear. We used a biometrical genetic approach to determine whether host genetic factors contribute to inter-individual differences in taxa from a sample of 332 twins who self-identified as being of African (44 pairs) or European ancestry (122 pairs). Lactobacillus crispatus, a major determinant of vaginal health, was identified as heritable among European American women (narrow-sense heritability = 34.7%, P-value = 0.018). Heritability of L. crispatus is consistent with the reduced prevalence of adverse reproductive disorders, including bacterial vaginosis and preterm birth, among women of European ancestry., Wright et al. apply biometric genetic approach to identify the extent to which host genetic factors influence species-level variation in the vaginal microbiota. Their study suggests that Lactobacillus crispatus, a major determinant of vaginal health, is heritable among European American women, consistent with the reduced prevalence of adverse reproductive disorders in them.

The incidence of preterm birth exceeds 10% worldwide. There are significant disparities in the frequency of preterm birth among populations within countries, and women of African ancestry disproportionately bear the burden of risk in the United States. In the present study, we report a community resource that includes 'omics' data from approximately 12,000 samples as part of the integrative Human Microbiome Project. Longitudinal analyses of 16S ribosomal RNA, metagenomic, metatranscriptomic and cytokine profiles from 45 preterm and 90 term birth controls identified harbingers of preterm birth in this cohort of women predominantly of African ancestry. Women who delivered preterm exhibited significantly lower vaginal levels of Lactobacillus crispatus and higher levels of BVAB1, Sneathia amnii, TM7-H1, a group of Prevotella species and nine additional taxa. The first representative genomes of BVAB1 and TM7-H1 are described. Preterm-birth-associated taxa were correlated with proinflammatory cytokines in vaginal fluid. These findings highlight new opportunities for assessment of the risk of preterm birth.

The microbiome of the female reproductive tract has implications for women’s reproductive health. We examined the vaginal microbiome in two cohorts of women who experienced normal term births: a cross-sectionally sampled cohort of 613 pregnant and 1,969 non-pregnant women, focusing on 300 pregnant and 300 non-pregnant women of African, Hispanic or European ancestry case-matched for race, gestational age and household income; and a longitudinally sampled cohort of 90 pregnant women of African or non-African ancestry. In these women, the vaginal microbiome shifted during pregnancy toward Lactobacillus-dominated profiles at the expense of taxa often associated with vaginal dysbiosis. The shifts occurred early in pregnancy, followed predictable patterns, were associated with simplification of the metabolic capacity of the microbiome and were significant only in women of African or Hispanic ancestry. Both genomic and environmental factors are likely contributors to these trends, with socioeconomic status as a likely environmental influence. Ancestry and socioeconomic factors influence predictable changes in the vaginal microbiome that occur early in pregnancy in women who experience normal term birth.

The incidence of preterm birth exceeds 10% worldwide. There are significant disparities in the frequency of preterm birth among populations within countries, and women of African ancestry disproportionately bear the burden of risk in the United States. In the present study, we report a community resource that includes 'omics' data from approximately 12,000 samples as part of the integrative Human Microbiome Project. Longitudinal analyses of 16S ribosomal RNA, metagenomic, metatranscriptomic and cytokine profiles from 45 preterm and 90 term birth controls identified harbingers of preterm birth in this cohort of women predominantly of African ancestry. Women who delivered preterm exhibited significantly lower vaginal levels of Lactobacillus crispatus and higher levels of BVAB1, Sneathia amnii, TM7-H1, a group of Prevotella species and nine additional taxa. The first representative genomes of BVAB1 and TM7-H1 are described. Preterm-birth-associated taxa were correlated with proinflammatory cytokines in vaginal fluid. These findings highlight new opportunities for assessment of the risk of preterm birth.

Background Bacterial vaginosis (BV) is the leading dysbiosis of the vaginal microbiome. The pathways leading towards the development of BV are not well understood. Gardnerella vaginalis is frequently associated with BV. G. vaginalis produces the cholesterol-dependent cytolysin (CDC), vaginolysin, which can lyse a variety of human cells and is thought to play a role in pathogenesis. Because membrane cholesterol is required for vaginolysin to function, and because HMG-CoA reductase inhibitors (statins) affect not only serum levels of cholesterol but membrane levels as well, we hypothesized that statins might affect the vaginal microbiome. Methods To investigate the relationship between use of the statins and the vaginal microbiome, we analyzed 16S rRNA gene taxonomic surveys performed on vaginal samples from 133 women who participated in the Vaginal Human Microbiome Project and who were taking statins at the time of sampling, 152 women who reported high cholesterol levels but were not taking statins, and 316 women who did not report high cholesterol. To examine the effect of statins on the cytolytic effect of vaginolysin, the cholesterol-dependent cytolysin (CDC) produced by Gardnerella vaginalis, we assessed the effect of simvastatin pretreatment of VK2E6/E7 vaginal epithelial cells on vaginolysin-mediated cytotoxicity. Results The mean proportion of G. vaginalis among women taking statins was significantly lower relative to women not using statins. Women using statins had higher mean proportions of Lactobacillus crispatus relative to women with normal cholesterol levels, and higher levels of Lactobacillus jensenii relative to women with high cholesterol but not taking statins. In vitro, vaginal epithelial cells pretreated with simvastatin were relatively resistant to vaginolysin and this effect was inhibited by cholesterol. Conclusions In this cross-sectional study, statin use was associated with reduced proportions of G. vaginalis and greater proportions of beneficial lactobacilli within the vaginal microbiome. The negative association between statin use and G. vaginalis may be related to inhibition of vaginolysin function.

Background Characterizing microbial communities via next-generation sequencing is subject to a number of pitfalls involving sample processing. The observed community composition can be a severe distortion of the quantities of bacteria actually present in the microbiome, hampering analysis and threatening the validity of conclusions from metagenomic studies. We introduce an experimental protocol using mock communities for quantifying and characterizing bias introduced in the sample processing pipeline. We used 80 bacterial mock communities comprised of prescribed proportions of cells from seven vaginally-relevant bacterial strains to assess the bias introduced in the sample processing pipeline. We created two additional sets of 80 mock communities by mixing prescribed quantities of DNA and PCR product to quantify the relative contribution to bias of (1) DNA extraction, (2) PCR amplification, and (3) sequencing and taxonomic classification for particular choices of protocols for each step. We developed models to predict the “true” composition of environmental samples based on the observed proportions, and applied them to a set of clinical vaginal samples from a single subject during four visits. Results We observed that using different DNA extraction kits can produce dramatically different results but bias is introduced regardless of the choice of kit. We observed error rates from bias of over 85% in some samples, while technical variation was very low at less than 5% for most bacteria. The effects of DNA extraction and PCR amplification for our protocols were much larger than those due to sequencing and classification. The processing steps affected different bacteria in different ways, resulting in amplified and suppressed observed proportions of a community. When predictive models were applied to clinical samples from a subject, the predicted microbiome profiles were better reflections of the physiology and diagnosis of the subject at the visits than the observed community compositions. Conclusions Bias in 16S studies due to DNA extraction and PCR amplification will continue to require attention despite further advances in sequencing technology. Analysis of mock communities can help assess bias and facilitate the interpretation of results from environmental samples. Electronic supplementary material The online version of this article (doi:10.1186/s12866-015-0351-6) contains supplementary material, which is available to authorized users.

Women of European ancestry are more likely to harbour a Lactobacillus-dominated microbiome, whereas African American women are more likely to exhibit a diverse microbial profile. African American women are also twice as likely to be diagnosed with bacterial vaginosis and are twice as likely to experience preterm birth. The objective of this study was to further characterize and contrast the vaginal microbial profiles in African American versus European ancestry women. Through the Vaginal Human Microbiome Project at Virginia Commonwealth University, 16S rRNA gene sequence analysis was used to compare the microbiomes of vaginal samples from 1268 African American women and 416 women of European ancestry. The results confirmed significant differences in the vaginal microbiomes of the two groups and identified several taxa relevant to these differences. Major community types were dominated by Gardnerella vaginalis and the uncultivated bacterial vaginosis-associated bacterium-1 (BVAB1) that were common among African Americans. Moreover, the prevalence of multiple bacterial taxa that are associated with microbial invasion of the amniotic cavity and preterm birth, including Mycoplasma, Gardnerella, Prevotella and Sneathia, differed between the two ethnic groups. We investigated the contributions of intrinsic and extrinsic factors, including pregnancy, body mass index, diet, smoking and alcohol use, number of sexual partners, and household income, to vaginal community composition. Ethnicity, pregnancy and alcohol use correlated significantly with the relative abundance of bacterial vaginosis-associated species. Trends between microbial profiles and smoking and number of sexual partners were observed; however, these associations were not statistically significant. These results support and extend previous findings that there are significant differences in the vaginal microbiome related to ethnicity and demonstrate that these differences are pronounced even in healthy women.

Until recently, bacterial species that inhabit the human vagina have been primarily studied using organism-centric approaches. Understanding how these bacterial species interact with each other and the host vaginal epithelium is essential for a more complete understanding of vaginal health. Molecular approaches have already led to the identification of uncultivated bacterial taxa associated with bacterial vaginosis. Here, we review recent studies of the vaginal microbiome and discuss how culture-independent approaches, such as applications of next-generation sequencing, are advancing the field and shifting our understanding of how vaginal health is defined. This work may lead to improved diagnostic tools and treatments for women who suffer from, or are at risk for, vaginal imbalances, pregnancy complications, and sexually acquired infections. These approaches may also transform our understanding of how host genetic factors, physiological conditions (e.g., menopause), and environmental exposures (e.g., smoking, antibiotic usage) influence the vaginal microbiome.

Until recently, bacterial species that inhabit the human vagina have been primarily studied using organism-centric approaches. Understanding how these bacterial species interact with each other and the host vaginal epithelium is essential for a more complete understanding of vaginal health. Molecular approaches have already led to the identification of uncultivated bacterial taxa associated with bacterial vaginosis. Here, we review recent studies of the vaginal microbiome and discuss how culture-independent approaches, such as applications of next-generation sequencing, are advancing the field and shifting our understanding of how vaginal health is defined. This work may lead to improved diagnostic tools and treatments for women who suffer from, or are at risk for, vaginal imbalances, pregnancy complications, and sexually acquired infections. These approaches may also transform our understanding of how host genetic factors, physiological conditions (e.g., menopause), and environmental exposures (e.g., smoking, antibiotic usage) influence the vaginal microbiome.

Worldwide, bacterial vaginosis (BV) is the most common vaginal disorder in women of childbearing age. BV is characterized by a dramatic shift in the vaginal microflora, involving a relative decrease in lactobacilli, and a proliferation of anaerobes. In most cases of BV, the predominant bacterial species found is Gardnerella vaginalis. However, pure cultures of G. vaginalis do not always result in BV, and asymptomatic women are sometimes colonized with low numbers of G. vaginalis. Thus, there is controversy about whether G. vaginalis is an opportunistic pathogen and the causative agent of many cases of BV, or whether BV is a polymicrobial condition caused by the collective effects of an altered microbial flora. Recent studies of the biofilm-forming potential and cytotoxic activity of G. vaginalis have renewed interest in the virulence potential of this organism. In an effort to tease apart the aetiology of this disorder, we utilized in vitro assays to compare three virulence properties of G. vaginalis relative to other BV-associated anaerobes. We designed a viable assay to analyse bacterial adherence to vaginal epithelial cells, we compared biofilm-producing capacities, and we assessed cytotoxic activity. Of the BV-associated anaerobes tested, only G. vaginalis demonstrated all three virulence properties combined. This study suggests that G. vaginalis is more virulent than other BV-associated anaerobes, and that many of the bacterial species frequently isolated from BV may be relatively avirulent opportunists that colonize the vagina after G. vaginalis has initiated an infection.

Objective Bacterial vaginosis is the most common vaginal disorder worldwide. Certain lactobacilli produce H 2 0 2 and lactic acid, which normally suppress growth of anaerobes; however, in bacterial vaginosis, Gardnerella vaginalis and other anaerobes proliferate, and the number of lactobacilli decreases. G vaginalis colonizes the vaginal epithelium as a biofilm, which likely plays a role in colonization and relapsing infection. Study Design We developed an in vitro model for G vaginalis biofilm formation and compared susceptibilities of biofilms vs planktonic cultures to H 2 0 2 and lactic acid. The structure and composition of the biofilm matrix were studied in order to design a method for biofilm dissolution. Results Biofilms tolerated 5-fold and 4-8 fold higher concentrations of H 2 0 2 and lactic acid (respectively) than planktonic cultures. Proteolytic dissolution of biofilms reduced sensitivity to H 2 0 2 and lactic acid. Conclusion Increased tolerance to H 2 0 2 and lactic acid suggests that biofilm formation contributes to the survival of G vaginalis in the presence of lactobacilli.

tion. Four months post operation, she continues vaginal dilation without evidence of constipation or fecal incontinence. Patient C was born with a cloacal anomaly and had an anorectoplasty and urogenital sinus mobilization as an infant. At age 5 she complained of urinary incontinence and on exam was found to have a posterior urethral diverticulum, stenosed introitus and residual vaginal septum. She underwent a posterior sagittal vaginourethroplasty for combined access for resection of the vaginal septum, enlarging the introitus and resection of the posterior urethral diverticulum. Again, no change in bowel habits at the follow-up evaluation. Comments: The posterior sagittal approach has been shown to provide exceptional exposure to the pelvic structures. These three cases demonstrate how this surgical method can be used for management of gynecologic conditions, especially when other approaches have been unsuccessful or would be more surgically challenging. This approach can also be used safely and effectively in patients with isolated gynecologic concerns who have not been treated for an anorectal malformation. The improved access to the surgical field, without concerns of adverse effects on bowel functions, reinforce the role of this approach in more challenging cases, especially revisional surgeries or high vaginal lesions. Gynecologists performing reconstructive procedures should be aware of this approach to broaden the surgical options provided to patients.