HIV-Inducing Factor in Cervicovaginal Secretions Is Associated With Bacterial Vaginosis in HIV-1-Infected Women

Cumulative Lifetime Violence and Bacterial Vaginosis Infection in Sexually Transmitted Infections: Findings From a Retrospective Cohort Study Among Black Women at Risk for HIV

Introduction

Bacterial vaginosis is the most common vaginal condition among women of reproductive age and has been associated with sexually transmitted infections. This study examines the association between cumulative lifetime violence exposure, bacterial vaginosis, and sexually transmitted infections among Black women at risk for HIV.

Methods

HIV-negative Black women in a retrospective cohort study (N=230) completed survey questions on cumulative violence (exposure to sexual or physical abuse before age 18 years and exposure to intimate partner violence or sexual violence [partner or other] after age 18 years and past year), bacterial vaginosis (lifetime and past year), and sexually transmitted infection diagnosis (lifetime and past year). Logistic regression models estimated the associations between cumulative violence, bacterial vaginosis, and sexually transmitted infections. Bacterial vaginosis was examined as a moderator in the association between cumulative violence and sexually transmitted infections.

Results

Many women reported cumulative violence exposure (40%), lifetime bacterial vaginosis diagnosis (53%), and lifetime sexually transmitted infection diagnosis (73%). Cumulative violence experience was significantly associated with increased adjusted odds of lifetime bacterial vaginosis diagnosis (AOR=1.98; 95% CI=1.10, 3.54). Lifetime bacterial vaginosis diagnosis (AOR=2.76; 95% CI=1.45, 5.22) and past-year bacterial vaginosis diagnosis (AOR=2.16; 95% CI=1.14, 4.10) were significantly associated with increased odds of lifetime sexually transmitted infection diagnosis. Lifetime bacterial vaginosis diagnosis (AOR=2.10; 95% CI=1.19, 3.70) and past-year bacterial vaginosis diagnosis (AOR=3.00; 95% CI=1.70, 5.31) were significantly associated with past-year sexually transmitted infection diagnosis. Lifetime bacterial vaginosis infection significantly increased the odds of lifetime sexually transmitted infection diagnosis with increasing cumulative violence exposure.

Conclusions

Our findings support educating and screening Black women who experience cumulative violence for bacterial vaginosis to reduce the risk of untreated bacterial vaginosis and sexually transmitted infections.

The Vaginal Microbiome: III. The Vaginal Microbiome in Various Urogenital Disorders

OBJECTIVE

This series of articles, titled The Vaginal Microbiome (VMB), written on behalf of the International Society for the Study of Vulvovaginal Disease, aims to summarize the recent findings and understanding of the vaginal bacterial microbiota, mainly regarding areas relevant to clinicians specializing in vulvovaginal disorders.

MATERIALS AND METHODS

A search of PubMed database was performed, using the search terms "vaginal microbiome" with "Candida," "vaginitis," "urinary microbiome," "recurrent urinary tract infections," "sexually transmitted infections," "human immunodeficiency virus," "human papillomavirus," "nonspecific vaginitis," "vulvodynia," and "vulvovaginal symptoms." Full article texts were reviewed. Reference lists were screened for additional articles. The third article in this series describes VMB in various urogenital disorders.

RESULTS

Variable patterns of the VMB are found in patients with vulvovaginal candidiasis, challenging the idea of a protective role of lactobacilli. Highly similar strains of health-associated commensal bacteria are shared in both the bladder and vagina of the same individual and may provide protection against urinary tract infections. Dysbiotic VMB increases the risk of urinary tract infection. Loss of vaginal lactic acid-producing bacteria combined with elevated pH, increase the risk for sexually transmitted infections, although the exact protective mechanisms of the VMB against sexually transmitted infections are still unknown.

CONCLUSIONS

The VMB may constitute a biological barrier to pathogenic microorganisms. When the predominance of lactobacilli community is disrupted, there is an increased risk for the acquisition of various vaginal pathogents. Longitudinal studies are needed to describe the association between the host, bacterial, and fungal components of the VMB.

Dynamic Alteration in the Vaginal Secretory Proteome across the Early and Mid-Trimesters of Pregnancy

Pregnancy is characterized by intense physiological and structural alterations in the vagina, cervix, and overlying fetal membranes. High vaginal fluid (HVF) is a proximal fluid that covers the lower part of the female reproductive system and the severity of vaginal pathology often adversely affects pregnancy outcomes. To identify the correlation of vaginal fluid proteome dynamics and physiological changes during the progression of pregnancy, a longitudinal study was performed on 20 pregnant women who delivered a baby in >37 weeks without any complications. SWATH-MS-based label-free quantitative proteomics was performed to profile the HVF proteome at three time points defined as V1 (7-12 weeks), V2 (18-20 weeks), and V3 (26-28 weeks). Linear mixed-effect models were used to estimate protein abundance as a function of the period of gestational age. In this study, we identified 1015 HVF proteins and 61 of them were significantly altered until late second trimester. Our result demonstrates that the HVF proteins reveal gestational age-specific expression patterns and the function of these proteins is associated with tissue remodeling, organ development, and microbial defense. Our study provides an opportunity to monitor the underlying physiology of pregnancy that may be further probed for the biomarker identification in pregnancy-related adverse outcomes. Data are available via ProteomeXchange with identifiers PXD014846 and PXD021811.

Saccharomyces cerevisiae-Based Probiotics as Novel Antimicrobial Agents to Prevent and Treat Vaginal Infections

Vaginal infections affect 70% of women during their lifetimes and account for millions of annual doctors’ visits. These infections are predominantly represented by vulvovaginal candidiasis (VVC) and bacterial vaginosis (BV). Although standard antimicrobial agents remain the major strategy for the prevention and treatment of vaginal infections, both VVC and BV are difficult to treat due to high rates of resistance and recurrence, high probability of complications, and negative effects on the vaginal microbiota. This review focuses on a new approach of yeast-based probiotics for the prevention and/or treatment of these common vaginal infections.

Impact of reproductive aging on the vaginal microbiome and soluble immune mediators in women living with and at-risk for HIV infection

BACKGROUND

Reproductive aging may impact the vaginal microbiome and genital tract mucosal immune environment and contribute to genital tract health in women living with and at-risk for HIV infection.

METHODS

A cross-sectional study of 102 HIV+ (51 premenopausal, 51 postmenopausal) and 39 HIV-uninfected (HIV-) (20 premenopausal, 19 postmenopausal) women was performed in Bronx and Brooklyn, NY. Cervicovaginal lavage (CVL) was collected for quantification of innate antimicrobial activity against E. coli, HSV-2 and HIV and immune mediators by Luminex and ELISA. Microbiome studies by qPCR and 16S rRNA sequencing were performed on vaginal swabs.

RESULTS

HIV+ postmenopausal compared to premenopausal participants had lower median E. coli bactericidal activity (41% vs. 62%, p = 0.001), lower median gene copies of Lactobacillus crispatus (p = 0.005) and Lactobacillus iners (p = 0.019), lower proportions of Lactobacillus iners, higher proportions of Gardnerella and Atopobium vaginae and lower levels of human beta defensins (HBD-2, HBD-3) and secretory leukocyte protease inhibitor (SLPI), p<0.001. HSV-2 inhibitory activity was higher in HIV+ postmenopausal compared to premenopausal participants (37% vs. 17%, p = 0.001) and correlated with the proinflammatory molecules interleukin (IL) 6, IL-8, human neutrophil peptide (HNP) 1-3, lactoferrin and fibronectin. Similar trends were observed in HIV- postmenopausal compared to premenopausal participants. HIV inhibitory activity did not differ by reproductive status in the HIV+ participants but was significantly higher in HIV- postmenopausal compared to premenopausal participants and in participants with suppressed plasma viral load, and inversely correlated with gene copies of G. vaginalis and BVAB2. A significant proportion of HIV+ participants on ART exhibited HIV enhancing activity.

CONCLUSIONS

HIV+ postmenopausal compared to premenopausal participants have less CVL E. coli bactericidal activity, reflecting a reduction in Lactobacilli and a greater proportion of Gardnerella and A. vaginae, and more HSV-2 inhibitory activity, reflecting increased mucosal inflammation. The effect of menopause on mucosal immunity was greater in HIV+ participants, suggesting a synergistic impact. Promotion of a lactobacillus dominant vaginal microbiome and reduced mucosal inflammation may improve vaginal health and reduce risk for shedding of HIV and potential for HIV transmission in HIV+ menopausal women.

Ecological dynamics of the vaginal microbiome in relation to health and disease

The bacterial composition of the vaginal microbiome is thought to be related to health and disease states of women. This microbiome is particularly dynamic, with compositional changes related to pregnancy, menstruation, and disease states such as bacterial vaginosis. In order to understand these dynamics and their impact on health and disease, ecological theories have been introduced to study the complex interactions between the many taxa in the vaginal bacterial ecosystem. The goal of this review is to introduce the ecological principles that are used in the study of the vaginal microbiome and its dynamics, and to review the application of ecology to vaginal microbial communities with respect to health and disease. Although applications of vaginal microbiome analysis and modulation have not yet been introduced into the routine clinical setting, a deeper understanding of its dynamics has the potential to facilitate development of future practices, for example in the context of postmenopausal vaginal symptoms, stratifying risk for obstetric complications, and controlling sexually transmitted infections.

Vaginal microbiota and susceptibility to HIV

: Bacterial vaginosis, characterized by the replacement of the Lactobacillus-dominant microbiota with anaerobic bacteria and facultative Gram-negative rods, has been associated with adverse reproductive health outcomes including HIV acquisition. With the advent of newer molecular techniques, the vaginal microbiota can be investigated in more detail and the association with HIV examined more thoroughly. This review examines recent evidence suggesting that vaginal dysbiosis with increased microbial diversity, specific vaginal bacterial communities, and the presence and concentrations of some individual bacterial species, may increase HIV susceptibility. Potential mechanisms through which vaginal microbiota could impact HIV susceptibility are discussed. On the basis of the available data, this review finds that there is a modest, but growing, body of evidence linking vaginal microbiota to HIV susceptibility in women. The evidence could be strengthened through two main pathways. First, laboratory studies such as ex-vivo or animal experiments are needed to move from plausible mechanisms towards proven mechanisms that explain an effect of the vaginal microbiota on HIV susceptibility. Second, experimental evidence could directly test the hypothesis that sustaining optimal microbiota reduces HIV risk, though there are important obstacles to conducting such studies. Finally, this review examines strong evidence from a recent publication suggesting that deviations from an optimal vaginal microbiome, and particularly the presence of some bacterial communities with high relative abundance of Gardnerella vaginalis, reduces the efficacy of vaginal tenofovir-based microbicides.

Evaluation of the association between the concentrations of key vaginal bacteria and the increased risk of HIV acquisition in African women from five cohorts: a nested case-control study

BACKGROUND

Disruptions of vaginal microbiota might increase women's susceptibility to HIV infection. Advances in molecular microbiology have enabled detailed examination of associations between vaginal bacteria and HIV acquisition. Therefore, this study aimed to evaluate the association between the concentrations of specific vaginal bacteria and increased risk of HIV acquisition in African women.

METHODS

We did a nested case-control study of participants from eastern and southern Africa. Data from five cohorts of African women (female sex workers, pregnant and post-partum women, and women in serodiscordant relationships) were used to form a nested case-control analysis between women who acquired HIV infection versus those who remained seronegative. Deep sequence analysis of broad-range 16S rRNA gene PCR products was applied to a subset of 55 cases and 55 controls. From these data, 20 taxa were selected for bacterium-specific real-time PCR assays, which were examined in the full cohort as a four-category exposure (undetectable, first tertile, second tertile, and third tertile of concentrations). Conditional logistic regression was used to generate odds ratios (ORs) and 95% CIs. Regression models were stratified by cohort, and adjusted ORs (aORs) were generated from a multivariable model controlling for confounding variables. The Shannon Diversity Index was used to measure bacterial diversity. The primary analyses were the associations between bacterial concentrations and risk of HIV acquisition.

FINDINGS

Between November, 2004, and August, 2014, we identified 87 women who acquired HIV infection (cases) and 262 controls who did not acquire HIV infection. Vaginal bacterial community diversity was higher in women who acquired HIV infection (median 1·3, IQR 0·4-2·3) than in seronegative controls (0·7, 0·1-1·5; p=0·03). Seven of the 20 taxa showed significant concentration-dependent associations with increased odds of HIV acquisition: Parvimonas species type 1 (first tertile aOR 1·67, 95% CI 0·61-4·57; second tertile 3·01, 1·13-7·99; third tertile 4·64, 1·73-12·46; p=0·005) and type 2 (first tertile 3·52, 1·63-7·61; second tertile 0·85, 0·36-2·02; third tertile 2·18, 1·01-4·72; p=0·004), Gemella asaccharolytica (first tertile 2·09, 1·01-4·36; second tertile 2·02, 0·98-4·17; third tertile 3·03, 1·46-6·30; p=0·010), Mycoplasma hominis (first tertile 1·46, 0·69-3·11; second tertile 1·40, 0·66-2·98; third tertile 2·76, 1·36-5·63; p=0·048), Leptotrichia/Sneathia (first tertile 2·04, 1·02-4·10; second tertile 1·45, 0·70-3·00; third tertile 2·59, 1·26-5·34; p=0·046), Eggerthella species type 1 (first tertile 1·79, 0·88-3·64; second tertile 2·62, 1·31-5·22; third tertile 1·53, 0·72-3·28; p=0·041), and vaginal Megasphaera species (first tertile 3·15, 1·45-6·81; second tertile 1·43, 0·65-3·14; third tertile 1·32, 0·57-3·05; p=0·038).

INTERPRETATION

Differences in the vaginal microbial diversity and concentrations of key bacteria were associated with greater risk of HIV acquisition in women. Defining vaginal bacterial taxa associated with HIV risk could point to mechanisms that influence HIV susceptibility and provide important targets for future prevention research.

FUNDING

National Institute of Child Health and Human Development.

Colonization of the cervicovaginal space with Gardnerella vaginalis leads to local inflammation and cervical remodeling in pregnant mice

The role of the cervicovaginal (CV) microbiome in regulating cervical function during pregnancy is poorly understood. Gardnerella vaginalis (G. vaginalis) is the most common bacteria associated with the diagnosis of bacterial vaginosis (BV). While BV has been associated with preterm birth (PTB), clinical trials targeting BV do not decrease PTB rates. It remains unknown if G. vaginalis is capable of triggering molecular, biomechanical and cellular events that could lead to PTB. The objective of this study was to determine if cervicovaginal colonization with G. vaginalis, in pregnant mice, induced cervical remodeling and modified cervical function. CD-1 timed-pregnant mice received a 5X10⁸ CFU/mL intravaginal inoculation of G. vaginalis or control on embryonic day 12 (E12) and E13. On E15, the mice were sacrificed and cervicovaginal fluid (CVF), amniotic fluid (AF), cervix, uterus, placentas and fetal membranes (FM) were collected. Genomic DNA was isolated from the CVF, placenta, uterus and FM and QPCR was performed to confirm colonization. IL-6 was measured in the CVF and AF and soluble e-cadherin (seCAD) was assessed in the CVF by ELISA. RNA was extracted from the cervices to evaluate IL-10, IL-8, IL-1β, TNF-α, Tff-1, SPINK-5, HAS-1 and LOX expression via QPCR. Mucicarmine and trichrome staining was used to assess cervical mucin and collagen. Biomechanical properties of the cervix were studied using quasi-static tensile load-to-failure biomechanical tests. G. vaginalis successfully colonized the CV space. This colonization induced immune responses (increased IL-6 levels in CVF and AF, increased mRNA expression of cervical cytokines), altered the epithelial barrier (increased seCAD in the CVF), induced cervical remodeling (increased mucin production, altered collagen) and altered cervical biomechanical properties (a decrease in biomechanical modulus and an increase in maximum strain). The ability of G. vaginalis to induce these molecular, immune, cellular and biomechanical changes suggests that this bacterium may play a pathogenic role in premature cervical remodeling leading to PTB.

Association between statin use, the vaginal microbiome, and Gardnerella vaginalis vaginolysin-mediated cytotoxicity

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.

Prevalence of Bacterial Vaginosis and Associated Risk Factors among Women Complaining of Genital Tract Infection

Background

Bacterial vaginosis is a global concern due to the increased risk of acquisition of sexually transmitted infections.

Objectives

To determine the prevalence of bacterial vaginosis and bacteria causing aerobic vaginitis.

Methods

A cross-sectional study was conducted among 210 patients between September 2015 and July 2016 at St. Paul's Hospital. Gram-stained vaginal swabs were examined microscopically and graded as per Nugent's procedure. Bacteria causing aerobic vaginitis were characterized, and their antimicrobial susceptibility pattern was determined.

Results

The overall prevalence of bacterial vaginosis was 48.6%. Bacterial vaginosis was significantly associated with number of pants used per day (p = 0.001) and frequency of vaginal bathing (p = 0.045). Of 151 bacterial isolates, 69.5% were Gram-negative and 30.5% were Gram-positive bacteria. The overall drug resistance level of Gram-positive bacteria was high against penicillin, tetracycline, and erythromycin. Cefoxitin and tobramycin were the most active drugs against Gram-positive bacteria. The overall drug resistance level of Gram-negative bacteria was high against tetracycline, ampicillin, and amoxicillin. Amikacin and tobramycin were the most active drugs against Gram-negative bacteria.

Conclusions

The prevalence of bacterial vaginosis was high and was affected by individual hygiene. Routine culture of vaginal samples should be performed on patients with vaginitis and the drug susceptibility pattern of each isolate should be determined.

Effects of combined oral contraceptives, depot medroxyprogesterone acetate and the levonorgestrel-releasing intrauterine system on the vaginal microbiome

OBJECTIVES

Prior studies suggest that the composition of the vaginal microbiome may positively or negatively affect susceptibility to sexually transmitted infections (STIs) and bacterial vaginosis (BV). Some female hormonal contraceptive methods also appear to positively or negatively influence STI transmission and BV. Therefore, changes in the vaginal microbiome that are associated with different contraceptive methods may explain, in part, effects on STI transmission and BV.

STUDY DESIGN

We performed a retrospective study of 16S rRNA gene survey data of vaginal samples from a subset of participants from the Human Vaginal Microbiome Project at Virginia Commonwealth University. The subset included 682 women who reported using a single form of birth control that was condoms, combined oral contraceptives (COCs), depot medroxyprogesterone acetate (DMPA) or the levonorgestrel-releasing intrauterine system (LNG-IUS).

RESULTS

Women using COCs [adjusted odds ratio (aOR) 0.29, 95% confidence interval (CI) 0.13-0.64] and DMPA (aOR 0.34, 95% CI 0.13-0.89), but not LNG-IUS (aOR 1.55, 95% CI 0.72-3.35), were less likely to be colonized by BV-associated bacteria relative to women who used condoms. Women using COCs (aOR 1.94, 95% CI 1.25-3.02) were more likely to be colonized by beneficial H₂O₂-producing Lactobacillus species compared with women using condoms, while women using DMPA (aOR 1.09, 95% CI 0.63-1.86) and LNG-IUS (aOR 0.74, 95% CI 0.48-1.15) were not.

CONCLUSIONS

Use of COCs is significantly associated with increased vaginal colonization by healthy lactobacilli and reduced BV-associated taxa.

IMPLICATIONS

COC use may positively influence gynecologic health through an increase in healthy lactobacilli and a decrease in BV-associated bacterial taxa.

Evaluation and subsequent optimizations of the quantitative AmpliSens Florocenosis/Bacterial vaginosis-FRT multiplex real-time PCR assay for diagnosis of bacterial vaginosis

Traditional microscopy-based methods for diagnosis of bacterial vaginosis (BV) are underutilized in many settings, and molecular techniques may provide opportunities for rapid, objective, and accurate BV diagnosis. This study evaluated the quantitative AmpliSens Florocenosis/Bacterial vaginosis-FRT multiplex real-time PCR (Florocenosis-BV) assay. Vaginal samples from a previous study including unselected female subjects (n = 163) and using Amsel criteria and 454 pyrosequencing for BV diagnosis were examined with the Florocenosis-BV test and additionally tested for the presence and quantity of Gardnerella vaginalis clades 3 and 4. The Florocenosis-BV assay demonstrated 100% and 98% sensitivity compared with the Amsel criteria and 454 pyrosequencing, respectively, with 91% specificity. The modified Florocenosis-BV assay (detecting also G. vaginalis clades 3 and 4) resulted in 100% sensitivity vs the Amsel criteria and 454 pyrosequencing with specificity of 86% and 88%, respectively. Further optimizations of thresholds for the quantitative parameters used in the kit resulted in 99-100% accuracy vs Amsel criteria and 454 pyrosequencing for selected parameters. The Florocenosis-BV assay is an objective, accurate, sensitive, and specific method for BV diagnosis; however, the performance of the test can be further improved with some minor optimizations.

Evaluation of Lysis Methods for the Extraction of Bacterial DNA for Analysis of the Vaginal Microbiota

Background

Recent studies on the vaginal microbiota have employed molecular techniques such as 16S rRNA gene sequencing to describe the bacterial community as a whole. These techniques require the lysis of bacterial cells to release DNA before purification and PCR amplification of the 16S rRNA gene. Currently, methods for the lysis of bacterial cells are not standardised and there is potential for introducing bias into the results if some bacterial species are lysed less efficiently than others. This study aimed to compare the results of vaginal microbiota profiling using four different pretreatment methods for the lysis of bacterial samples (30 min of lysis with lysozyme, 16 hours of lysis with lysozyme, 60 min of lysis with a mixture of lysozyme, mutanolysin and lysostaphin and 30 min of lysis with lysozyme followed by bead beating) prior to chemical and enzyme-based DNA extraction with a commercial kit.

Results

After extraction, DNA yield did not significantly differ between methods with the exception of lysis with lysozyme combined with bead beating which produced significantly lower yields when compared to lysis with the enzyme cocktail or 30 min lysis with lysozyme only. However, this did not result in a statistically significant difference in the observed alpha diversity of samples. The beta diversity (Bray-Curtis dissimilarity) between different lysis methods was statistically significantly different, but this difference was small compared to differences between samples, and did not affect the grouping of samples with similar vaginal bacterial community structure by hierarchical clustering.

Conclusions

An understanding of how laboratory methods affect the results of microbiota studies is vital in order to accurately interpret the results and make valid comparisons between studies. Our results indicate that the choice of lysis method does not prevent the detection of effects relating to the type of vaginal bacterial community one of the main outcome measures of epidemiological studies. However, we recommend that the same method is used on all samples within a particular study.

Can one size fit all? Approach to bacterial vaginosis in sub-Saharan Africa

Bacterial vaginosis (BV) is the most common vaginal disorder affecting women of reproductive age and is associated with increased risk of sexually transmitted infections such as human immunodeficiency syndrome (HIV-1). Sub-Saharan Africa has the highest BV and HIV-1 burden and yet very few studies have focused on understanding the aetiology of BV and its association with HIV in this region. It has been suggested that we need to accurately diagnose and treat BV to lower the risk of HIV infection globally. However, effective diagnosis requires knowledge of what constitutes a "healthy" cervicovaginal microbiome and current studies indicate that Lactobacillus crispatus might not be the only commensal protective against BV: healthy women from different countries and ethnicities harbour alternative commensals. Microbiotas associated with BV have also shown global variation, further complicating effective diagnosis via culture-based assays as some species are difficult to grow. Antibiotics and probiotics have been suggested to be key in controlling BV infection, but the efficacy of this treatment might rely on reconstituting endogenous commensals while targeting a specific species of BV-associated bacteria (BVAB). Alternatively, therapy could inhibit essential BV bacterial growth factors e.g. sialidases or provide anti-microbial compounds e.g. lactic acid associated with a healthy cervicovaginal microbiome. But without global investigation into the mechanism of BV pathogenesis and its association with HIV, selection of such compounds could be limited to Caucasian women from certain regions. To confirm this suggestion and guide future therapy we require standardised diagnostic assays and research methodologies. This review will focus on research papers that describe the global variation of BV aetiology and how this influences the identification of determinants of BV pathogenesis and potential probiotic and antimicrobial therapy.

Antimicrobial and immune modulatory effects of lactic acid and short chain fatty acids produced by vaginal microbiota associated with eubiosis and bacterial vaginosis

Lactic acid and short chain fatty acids (SCFAs) produced by vaginal microbiota have reported antimicrobial and immune modulatory activities indicating their potential as biomarkers of disease and/or disease susceptibility. In asymptomatic women of reproductive-age the vaginal microbiota is comprised of lactic acid-producing bacteria that are primarily responsible for the production of lactic acid present at ~110 mM and acidifying the vaginal milieu to pH ~3.5. In contrast, bacterial vaginosis (BV), a dysbiosis of the vaginal microbiota, is characterized by decreased lactic acid-producing microbiota and increased diverse anaerobic bacteria accompanied by an elevated pH>4.5. BV is also characterized by a dramatic loss of lactic acid and greater concentrations of mixed SCFAs including acetate, propionate, butyrate, and succinate. Notably women with lactic acid-producing microbiota have more favorable reproductive and sexual health outcomes compared to women with BV. Regarding the latter, BV is associated with increased susceptibility to sexually transmitted infections (STIs) including HIV. In vitro studies demonstrate that lactic acid produced by vaginal microbiota has microbicidal and virucidal activities that may protect against STIs and endogenous opportunistic bacteria as well as immune modulatory properties that require further characterization with regard to their effects on the vaginal mucosa. In contrast, BV-associated SCFAs have far less antimicrobial activity with the potential to contribute to a pro-inflammatory vaginal environment. Here we review the composition of lactic acid and SCFAs in respective states of eubiosis (non-BV) or dysbiosis (BV), their effects on susceptibility to bacterial/viral STIs and whether they have inherent microbicidal/virucidal and immune modulatory properties. We also explore their potential as biomarkers for the presence and/or increased susceptibility to STIs.

HIV vaccine trial exploits a dual and central role for innate immunity

Limited understanding of correlates of protection from HIV transmission hinders development of an efficacious vaccine. D. J. M. Lewis and colleagues (J. Virol. 88:11648-11657, 2014, doi:10.1128/JVI.01621-14) now report that vaginal immunization with an HIVgp140 vaccine linked to the 70-kDa heat shock protein downregulated the human immunodeficiency virus (HIV) coreceptor CCR5 (chemokine [C-C motif] receptor 5) and increased expression of the HIV resistance factor APOBEC3G (apolipoprotein B mRNA-editing, enzyme-catalytic, polypeptide-like 3G), in women. These effects correlated with HIV suppression ex vivo. Thus, vaccine-induced innate responses not only facilitate adaptive immunity-they may prove to be critical for preventing HIV transmission.

Association of plasma viremia with HIV-1 RNA levels in cervicovaginal lavage secretions in HIV-1 seropositive ART naïve women from Pune, India

BACKGROUND

Coherent drug/microbicide/vaccine development research would benefit through a precise knowledge of HIV dissemination and its persistence in the female genital tract. Understanding relationship between plasma viremia and cervicovaginal HIV shedding may help to unveil mechanisms underlying transmission, compartmentalization and pathogenesis.

OBJECTIVES

To study the association between HIV-1 RNA levels in the plasma and CVL specimens.

STUDY DESIGN

Whole blood, plasma and CVL specimens were collected from 36 ART naïve HIV-1 seropositive women qualifying the study inclusion criteria. Absolute CD4 counts, plasma and CVL HIV-1 RNA levels were estimated using commercially available kits (BD MultiSET™ Kit, Becton Dickinson, US and Abbott RT, Abbott Molecular, Germany). Correlation between plasma and CVL viral load was estimated by the Spearman's rank correlation coefficient. Additionally, the correlation between CVL viral load and absolute CD4 counts was studied.

RESULTS

HIV-1 viral load in the CVL specimens was successfully quantified using the Abbott RT. Twenty-seven of 36 women (75%) had detectable HIV-1 RNA levels in plasma and CVL specimens. The CVL viral load did not show any correlation with plasma viral load (ρ=0.281, p=0.096) and showed a 'moderate correlation' (ρ=-0.563, p=0.0004) with absolute CD4 counts.

CONCLUSIONS

Albeit, the Abbott RT is designed for estimating plasma HIV-1 RNA levels, the study reports its use for estimating HIV-1 RNA levels in the CVL specimens as well. In accordance with the previous studies, our results suggest that plasma and CVL viral load are not correlated and plasma viremia might not solely predict cervico vaginal HIV shedding.

Effect of trichomoniasis therapy on genital HIV viral burden among African women

BACKGROUND

Our objective was to test the hypothesis that treatment for trichomoniasis among HIV-infected women not taking antiretrovirals in South Africa would be associated with decreased HIV genital shedding.

METHODS

HIV-infected women presenting for routine HIV care were screened for trichomoniasis using self-collected vaginal swabs with a rapid point-of-care immunochromatographic antigen test. Women testing positive were offered enrollment into a prospective cohort study, if they had documented HIV infection, were aged 18 to 50 years, and were not receiving antiretroviral therapy. Recent use of postexposure prophylaxis or antibiotic therapy, active genital ulcers, or systemic illness were exclusion criteria. Cervical swabs were collected for gonococcal and chlamydial testing, and those testing positive were excluded. Women were treated with directly observed oral therapy with 2 g of oral metronidazole. A follow-up visit was scheduled 1 month after therapy, and partner letters were provided. Paired cervical wicks and plasma were collected for viral load measurement.

RESULTS

In all, 557 women were screened. Sixty tested positive for trichomoniasis, 10 subsequently met exclusion criteria, and 4 were lost to follow-up. Of 46 women evaluated at follow-up, 37 (80.4%) were cured. Plasma viral load was not significantly different after therapy (P = 0.93). Genital tract viral load decreased by 0.5 log10 (P < 0.01). The mean genital tract viral load (log10) decreased from 4.66 (<3.52-6.46) to 4.18 (<3.52-6.48) (P < 0.01) after therapy.

CONCLUSIONS

Screening and treatment of vaginal trichomoniasis decrease genital shedding of HIV among South African women not receiving antiretrovirals at 1 month after therapy.

Genital tract viral load in HIV Type 1-positive women correlates with specific cytokine levels in cervical-vaginal secretions but is not a determinant of infectious virus or anti-HIV activity

As the AIDS epidemic continues with women being disproportionately affected, it is crucial to understand factors that predict the risk of heterosexual HIV-1 transmission. We investigated whether genital tract viral load (GTVL) in cervical-vaginal lavages (CVL) from HIV-1-positive women with moderately low CD4 T cell counts correlates with cytokine levels, antimicrobial concentrations, and intrinsic anti-HIV activity. CVL were collected from 19 HIV-1-positive women with moderately low CD4 T cell counts [mean 381 cells/mm(3) (227-536 cells/mm(3))]. None of the women was on antiretroviral therapy. The women were categorized into those with detectable GTVL or those with undetectable GTVL (detectable GTVL RNA levels > 400 copies/ml). Women were also categorized according to bacterial vaginosis (BV) status irrespective of GTVL. The TZM-bl assay was used to determine the presence of infectious virus and anti-HIV activity. Significantly higher levels of RANTES, Eotaxin, Fractalkine, IL-1α, IL-6, MCP-1, MIP1β, MIP1α, TNF-α, and GM-CSF were observed in women with detectable GTVL compared to women with undetectable GTVL. No significant differences were observed in the following cytokines and chemokines: G-CSF, IL-1RA, IL-8, and IP-10. GTVL did not correlate either with antimicrobials known to have anti-HIV activity or with the presence of infectious virus. BV status did not have a significant effect on anti-HIV activity. These findings further our understanding of the role of GTVL in determining the cytokine and chemokine milieu in the female reproductive tract.

Diagnosis of vaginal discharge by wet mount microscopy: a simple and underrated method

Vaginal discharge is highly variable in quality and quantity among different individuals, and even in the same individual during different periods of life. Vaginal discharge is most commonly caused by infection with sexually transmitted organisms or increased colonization by different facultative pathogenic microorganisms (i.e., Gardnerella vaginalis). Noninfectious causes of vaginal discharge are quite rare (10% noninfectious as compared to 90% infectious causes). Most common in women with a vaginal infection is bacterial vaginosis (40%-50% of cases), followed by vulvovaginal candidosis (20%-25%), and then trichomoniasis (15%-20%). If infection is suspected as the primary cause, a sample of the vaginal discharge should be taken and examined microscopically. When evaluating vaginal secretions by phase-contrast wet mount microscopy, knowledge of what is normal versus abnormal is very important. Knowledge of the sensitivity and specificity of wet mount microscopy in different clinical settings is also important.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians

LEARNING OBJECTIVES

After completing this CME activity, physicians should be better able to evaluate lifetime changes in vaginal secretions, characterize the physiological and pathological appearance of vaginal discharge, assess the clinical practicality and usefulness of wet mount microscopy and use wet mount microscopy to diagnose bacterial vaginosis and other common vaginal infections.

Acceptance of self-testing for increased vaginal pH in different subsets of Ugandan women

We assessed the acceptance of self-testing for vaginal pH in 344 Ugandan women in different clinical settings. Women tested themselves by insertion of a gloved finger into the vagina to test vaginal pH and provide a smear on a glass slide. None of the tested women found the test very difficult: 8% found it somewhat difficult, 16% rather easy and 76% very easy to do. Of the 20% who found it difficult to read the test result, more women were attending a family planning clinic or had a higher diploma ( P = 0.001). Pregnant women were least likely to understand of the meaning of the test, while those visiting family planning clinics had the opposite experience. HIV-infected women were most motivated to accept: 95% would be happy to use the test more often if requested, and another 3.5% felt they might be better motivated to do repeat testing after extra explanation. Self-sampling of vaginal pH is well accepted by Ugandan women. Our new method also allows diagnostic work-up by formal microscopy. Before commencing large-scale population screening, unexpected reactions of different subpopulations should be taken into account.

Vaginal microbiome and sexually transmitted infections: an epidemiologic perspective

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.

Use of cervicovaginal fluid for the identification of biomarkers for pathologies of the female genital tract

Cervicovaginal fluid has an important function in the homeostasis and immunity of the lower female genital tract. Analysis of the cervicovaginal fluid proteome may therefore yield important information about the pathogenesis of numerous gynecological pathologies. Additionally, cervicovaginal fluid has great potential as a source of biomarkers for these conditions.

This review provides a detailed discussion about the human cervicovaginal proteome and the proteomics studies performed to characterize this biological fluid. Furthermore, infection-correlated pathological conditions of the female genital tract are discussed for which cervicovaginal fluid has been used in order to identify potential biomarkers. Recent years, numerous studies have analyzed cervicovaginal fluid samples utilizing antibody-based technologies, such as ELISA or Western blotting, to identify biomarkers for preterm birth, premature preterm rupture of membranes, bacterial vaginosis and cervical cancer. The present article will discuss the importance of proteomic technologies as alternative techniques to gain additional meaningful information about these conditions. In addition, the review focuses on recent proteomic studies on cervicovaginal fluid samples for the identification of potential biomarkers. We conclude that the use of proteomic technology for analysis of human cervicovaginal fluid samples is promising and may lead to the discovery of new biomarkers which can improve disease prevention and therapy development.

The epidemiology of bacterial vaginosis in relation to sexual behaviour

BACKGROUND

Bacterial vaginosis (BV) has been most consistently linked to sexual behaviour, and the epidemiological profile of BV mirrors that of established sexually transmitted infections (STIs). It remains a matter of debate however whether BV pathogenesis does actually involve sexual transmission of pathogenic micro-organisms from men to women. We therefore made a critical appraisal of the literature on BV in relation to sexual behaviour.

DISCUSSION

G. vaginalis carriage and BV occurs rarely with children, but has been observed among adolescent, even sexually non-experienced girls, contradicting that sexual transmission is a necessary prerequisite to disease acquisition. G. vaginalis carriage is enhanced by penetrative sexual contact but also by non-penetrative digito-genital contact and oral sex, again indicating that sex per se, but not necessarily coital transmission is involved. Several observations also point at female-to-male rather than at male-to-female transmission of G. vaginalis, presumably explaining the high concordance rates of G. vaginalis carriage among couples. Male antibiotic treatment has not been found to protect against BV, condom use is slightly protective, whereas male circumcision might protect against BV. BV is also common among women-who-have-sex-with-women and this relates at least in part to non-coital sexual behaviours. Though male-to-female transmission cannot be ruled out, overall there is little evidence that BV acts as an STD. Rather, we suggest BV may be considered a sexually enhanced disease (SED), with frequency of intercourse being a critical factor. This may relate to two distinct pathogenetic mechanisms: (1) in case of unprotected intercourse alkalinisation of the vaginal niche enhances a shift from lactobacilli-dominated microflora to a BV-like type of microflora and (2) in case of unprotected and protected intercourse mechanical transfer of perineal enteric bacteria is enhanced by coitus. A similar mechanism of mechanical transfer may explain the consistent link between non-coital sexual acts and BV. Similar observations supporting the SED pathogenetic model have been made for vaginal candidiasis and for urinary tract infection.

SUMMARY

Though male-to-female transmission cannot be ruled out, overall there is incomplete evidence that BV acts as an STI. We believe however that BV may be considered a sexually enhanced disease, with frequency of intercourse being a critical factor.

Biomedical approaches to HIV prevention

People who use and abuse alcohol and other drugs are an important population to target for HIV prevention because they are more likely to engage in sexual behaviors that increase their likelihood of acquiring or transmitting HIV. A variety of biomedical approaches to HIV prevention have been evaluated or currently are being studied. These approaches include an anti-HIV vaccine; topical protection treatments; and additional biomedical and barrier approaches, such as controlling sexually transmitted diseases, male circumcision, diaphragm use, and substance abuse treatment. The article also reviews topical versus oral antiretrovirals to prevent HIV transmission, antiretroviral treatment as prevention, and the role of alcohol and other drug use in HIV prevention.

Bacterial vaginosis: a problematic infection from both a perinatal and neonatal perspective

Bacterial vaginosis (BV) infections are common in women of reproductive age and are easily diagnosed and treatable. Aside from being an annoyance when symptoms of discharge, odor, and pruritus occur in the gravid female, BV infections increase risk of late miscarriage, preterm labor, preterm premature rupture of membranes, and, consequently, preterm delivery. Antepartum and puerperal issues such as chorioamnionitis and endometritis are increased in the context of maternal BV. Moreover, the morbidities and mortality of preterm delivery are consequently increased as a result of BV during pregnancy. Although the pathology associated with BV appears to result from inflammation, more investigation is needed in terms of designing guidelines for appropriate screening and treatment for the prevention of adverse outcomes.

[Bacterial vaginosis]

Bacterial vaginosis is a widely spread health problem with multiple connotations. It has been the subject of many studies and work during decades and it still remains a polemic entity, with contradictory finding. The polymicrobian etiology, unsolved epidemiology, obstetrico-gynecological complications and high recurrence rate following treatment, make this infection a target for researchers. It is not an inflammatory process -yet an immune response exists. In this disorder, vaginal discharge increases, and it is associated with a high risk of developing sexually transmitted diseases.

The effect of genital tract infections on HIV-1 shedding in the genital tract: a systematic review and meta-analysis

This article reviews the effect of genital tract infections and associated clinical conditions on the detection and concentration of HIV-1 shedding in the genital tract. A search of the PubMed, Embase, and AIDSearch databases was conducted. Meta-analysis was performed on those studies that reported the effect of genital tract infections on the detection of HIV-1 shedding. Thirty-nine studies met the inclusion criteria. The odds of HIV-1 detection in the genital tract were increased most substantially by urethritis (OR 3.1, 95% CI: 1.1-8.6) and cervicitis (OR 2.7, 95% CI: 1.4-5.2). The odds of HIV-1 detection were also increased significantly in the presence of cervical discharge or mucopus (OR 1.8, 95% CI: 1.2-2.7), gonorrhoea (OR 1.8, 95% CI: 1.2-2.7), chlamydial infection (OR 1.8, 95% CI: 1.1-3.1), and vulvovaginal candidiasis (OR 1.8, 95% CI: 1.3-2.4). Other infections and clinical conditions were found to have no significant effect on the detection of HIV-1, although HSV-2 shedding was found to increase the concentration of HIV-1 shedding, and genital ulcer disease was found to increase the odds of HIV-1 detection significantly after excluding one biased study (OR 2.4, 95% CI: 1.2-4.9). This analysis shows that infections that are associated with significant increases in leukocyte concentrations in the genital tract are also associated with significant increases in HIV-1 shedding. These infections are likely to be particularly important in promoting the sexual transmission and mother-to-child intrapartum transmission of HIV-1, and should therefore be the focus of HIV prevention strategies.

The prevalence of bacterial vaginosis in the United States, 2001-2004; associations with symptoms, sexual behaviors, and reproductive health

OBJECTIVES

Bacterial vaginosis (BV), a disturbance of vaginal microflora, is a common cause of vaginal symptoms and is associated with an increased risk of acquisition of sexually transmitted infections, HIV, and with adverse pregnancy outcomes. We determined prevalence and associations with BV among a representative sample of women of reproductive age in the United States.

STUDY DESIGN

Women aged 14-49 years participating in the National Health and Nutrition Examination Survey 2001-2004 were asked to submit a self-collected vaginal swab for Gram staining. BV, determined using Nugent's score, was defined as a score of 7-10.

RESULTS

The prevalence of BV was 29.2% (95% confidence interval 27.2%-31.3%) corresponding to 21 million women with BV; only 15.7% of the women with BV reported vaginal symptoms. Prevalence was 51.4% among non-Hispanic blacks, 31.9% among Mexican Americans, and 23.2% among non-Hispanic whites (P <0.01 for each comparison). Although BV was also associated with poverty (P <0.01), smoking (P <0.05), increasing body mass index (chi2 P <0.0001 for trend), and having had a female sex partner (P <0.005), in the multivariate model, BV only remained positively associated with race/ethnicity, increasing lifetime sex partners (chi2 P <0.001 for trend), increasing douching frequency (chi2 P for trend <0.001), low educational attainment (P <0.01), and inversely associated with current use of oral contraceptive pills (P <0.005).

CONCLUSION

BV is a common condition; 84% of women with BV did not report symptoms. Because BV increases the risk of acquiring sexually transmitted infections, BV could contribute to racial disparities in these infections.

An adherent Gardnerella vaginalis biofilm persists on the vaginal epithelium after standard therapy with oral metronidazole

OBJECTIVE

The purpose of this study was to determine the efficacy of standard treatment with oral metronidazole in the eradication of the bacterial vaginosis biofilm.

STUDY DESIGN

We conducted an interventional follow-up study in which 18 patients with bacterial vaginosis were treated with oral metronidazole during 1 week and subsequently had a single random follow-up assessment at 1-week intervals, up to 5 weeks, with 3 patients representing each point in time. Follow-up assessment included conventional scoring of the vaginal microflora and determination of bacterial biofilm characteristics on a vaginal biopsy through bacterial 16/23S recombinant DNA-based fluorescence in-situ hybridization.

RESULTS

Although all patients recovered, we consistently observed the resurgence with treatment cessation of a dense and active bacterial biofilm on the vaginal mucosa, primarily consisting of Gardnerella vaginalis and Atopobium vaginae.

CONCLUSION

A large reservoir of the core bacteria to bacterial vaginosis persists as a biofilm after metronidazole treatment.

Bacterial vaginosis and human immunodeficiency virus infection

Epidemiologic studies indicate that bacterial vaginosis (BV), a common alteration of lower genital tract flora in women, is associated with increased susceptibility to HIV infection. Other recent studies show that HIV is detected more frequently and at higher levels in the lower genital tract of HIV-seropositive women with BV. In vitro studies show that genital tract secretions from women with BV or flora associated with BV induce HIV expression in infected cells. The increased HIV expression appears to be due at least in part to activation through Toll-like receptors (TLR), specifically TLR2. Further research is needed to elucidate how BV contributes to HIV acquisition and transmission.

Dendritic cell activation and maturation induced by mucosal fluid from women with bacterial vaginosis

Dendritic cells (DC) at mucosal surfaces mature when exposed to "danger" signals such as LPS. Bacterial vaginosis (BV) is a prevalent alteration of the vaginal bacterial flora associated with preterm childbirth and increased risk for HIV acquisition. We examined the effect of mucosal fluid from women with BV or healthy flora on DC function. IL-12, IL-23 and p40 production by monocyte-derived dendritic cells (MDDC) were all induced by BV samples. Activation/maturation markers HLA-DR, CD40 and CD83 on MDDC incubated with BV CVL were also induced. BV CVL also decreased the endocytic ability of MDDC and increased proliferation of T cells in allogeneic MLR. Plasmacytoid dendritic cell (pDC) CD86 expression was induced by BV CVL. Healthy flora CVL had little effect in any of the tests. This study suggests that BV, but not healthy flora, affects local dendritic cell function in vivo suggesting a mechanism through which BV affects mucosal immunity.

Bacterial vaginosis and host immunity

Bacterial vaginosis (BV) has been associated with severe medical consequences including induction of preterm birth and increasing susceptibility to infection by HIV and other genital tract pathogens. Although the mechanism by which BV induces these changes is not yet fully defined, the presence of BV is accompanied by immunologic changes in the lower genital tract environment. The most striking change is the induction of higher levels of proinflammatory cytokines, although this is not accompanied by increased levels of neutrophils. Increased cytokine levels are likely induced by bacterial products present in BV through innate immune recognition pathways such as the toll-like receptors. Recent studies show that changes in HIV susceptibility and HIV detection are associated with changes in bacterial flora. Further research is needed to identify the relative contributions of immune pathways and bacterial flora toward the pathogenic alterations that occur in BV.

Relationship of U1 cell HIV-stimulatory activity to bacterial vaginosis and HIV genital tract virus load

Bacterial vaginosis (BV) has been associated with HIV sexual transmission and increased levels of genital tract HIV RNA. We postulated that BV induces the appearance of substances in the genital tract that stimulate HIV expression locally. To test this, we measured HIV RNA levels in genital mucosal fluid from women with or without BV (defined by Nugent score) and compared them with the ability of those fluids to stimulate HIV expression in the chronically HIV-infected monocytic line U1. The U1 activity was significantly higher in women with BV (median = 1320 pg/ml p24) than in women with normal flora (median = 103 pg/ml p24, p = 0.0001). However, levels of the U1 activity were not significantly associated with levels in the genital tract of HIV RNA. Levels of the U1 activity were also not associated with levels of Gardnerella vaginalis or Mycoplasma hominis in genital fluids, suggesting these bacteria were not the source of the activity. Thus, while these data show a strong association of U1 stimulatory activity with BV, no influence of the U1 activity on genital tract HIV expression was observed.