Utility of Amsel criteria, Nugent score, and quantitative PCR for Gardnerella vaginalis, Mycoplasma hominis, and Lactobacillus spp. for diagnosis of bacterial vaginosis in human immunodeficiency virus-infected women

Detection of Methanobrevibacter smithii in vaginal samples collected from women diagnosed with bacterial vaginosis

Vaginosis is a dysbiotic condition of the vaginal cavity that has deleterious effects during pregnancy. The role of methanogens in this disease is unknown since current methods of investigation are not appropriate for the search of methanogens. We prospectively investigated the presence of methanogens in vaginal specimens collected from 33 women thereafter diagnosed with bacterial vaginosis and 92 women thereafter diagnosed without bacterial vaginosis (control group) by direct microscopic examination and fluorescent in situ hybridization, PCR-sequencing, and real-time PCR and isolation and culture. These investigations found only one methanogen, Methanobrevibacter smithii, exclusively in 97% bacterial vaginosis specimens and in two intermediate microbiota specimens. M. smithii was detected microscopically in 2/20 specimens analyzed, by PCR-based observations in 34/125 specimens with 99% sequence similarity with the reference 16S rRNA and mcrA gene sequences and was cultured in 9/40 specimens. These data suggest that the detection of M. smithii could be used as a biomarker for the laboratory diagnosis of bacterial vaginosis.

Bacterial vaginosis: An insight into the prevalence, alternative treatments regimen and it's associated resistance patterns

Bacterial Vaginosis (BV) is a complex polymicrobial infection of vagina that shifts the paradigms of vaginal flora from lactobacilli to opportunistic pathogens. BV is catagorized by greyish white discharge, pH greater than 4.5. It results in the preterm labor, abortion, pelvic inflammatory disorders, post cesarean infections. BV is associated with Sexually Transmitted Diseases (STDs) or immune deficiency disorders like Human Immunodeficiency Virus, Human Papilloma Virus, Herpes Simplex Virus 1 and 2, and Neisseria gonorrhoeae. The prevalence rate is about 21.2 million (29.2%) worldwide. BV is more frequent in black females as compared to white females, independent of geographical distribution. Globally, BV is treated with the current recommended antibiotic therapy including Metronidazole and Clindamycin. The recurrence rates are 76% and occur within 06 months of treatment due to antibiotic resistance against pathogenic bacteria and their biofilms. The antibiotic resistance is a global health issue which directs the attentions towards other treatments. One of these is the treatment of sex partners, thus helping to stop the recurrence rates in females. However, this method does not show any positive results. Probiotic therapy is an incorporation of Lactobacilli orally or intravaginally for the recolonization of healthy microbes. This therapy has exhibited promising results but some studies revealed that Probiotic therapy does not control the recurrence rate. The other methods are in trials period and none of them are used clinically or commercially available for the treatment. The thermoplastic polyurethane (TPU) intravaginal rings contain lactic acid and metronidazole showed promising results in trials of BV treatment. The vaginal acidifiers are used as an alternative method to maintain the vaginal pH but the process of douching is a major limitation. The activated charcoal is used to treat BV patients in clinical trials showed decrease in the pH with only 3.1% loss of lactobacilli. Phage therapy is a reemerging field to overcome the bacterial resistance. They are host specific and easier to handle. They can be used naturally, synthetically; phage cocktails and phage-antibiotics combination can be used. Phages show auspicious results for the treatment of bacterial infections as compared to antibiotics as they also treat biofilms. This is one of the promising therapy in future to treat infections with no side effects. Phage therapy can be used in pharmaceuticals according to Food and Drug Administration (FDA) guidelines. Taken together, it is suggested that large funding is required by pharmaceutical sector or government for further investigation of bacteriophages to be used against BV pathogenesis.

Single-dose versus 7-day-dose metronidazole for the treatment of trichomoniasis in women: an open-label, randomised controlled trial

BACKGROUND

Among women, trichomoniasis is the most common non-viral sexually transmitted infection worldwide, and is associated with serious reproductive morbidity, poor birth outcomes, and amplified HIV transmission. Single-dose metronidazole is the first-line treatment for trichomoniasis. However, bacterial vaginosis can alter treatment efficacy in HIV-infected women, and single-dose metronidazole treatment might not always clear infection. We compared single-dose metronidazole with a 7-day dose for the treatment of trichomoniasis among HIV-uninfected, non-pregnant women and tested whether efficacy was modified by bacterial vaginosis.

METHODS

In this multicentre, open-label, randomised controlled trial, participants were recruited at three sexual health clinics in the USA. We included women positive for Trichomonas vaginalis infection according to clinical screening. Participants were randomly assigned (1:1) to receive either a single dose of 2 g of metronidazole (single-dose group) or 500 mg of metronidazole twice daily for 7 days (7-day-dose group). The randomisation was done by blocks of four or six for each site. Patients and investigators were aware of treatment assignment. The primary outcome was T vaginalis infection by intention to treat, at test-of-cure 4 weeks after completion of treatment. The analysis of the primary outcome per nucleic acid amplification test or culture was also stratified by bacterial vaginosis status. This trial is registered with ClinicalTrials.gov, number NCT01018095, and with the US Food and Drug Administration, number IND118276, and is closed to accrual.

FINDINGS

Participants were recruited from Oct 6, 2014, to April 26, 2017. Of the 1028 patients assessed for eligibility, 623 women were randomly assigned to treatment groups (311 women in the single-dose group and 312 women in the 7-day-dose group; intention-to-treat population). Although planned enrolment had been 1664 women, the study was stopped early because of funding limitations. Patients in the 7-day-dose group were less likely to be T vaginalis positive at test-of-cure than those in the single-dose group (34 [11%] of 312 vs 58 [19%] of 311, relative risk 0·55, 95% CI 0·34-0·70; p<0·0001). Bacterial vaginosis status had no significant effect on relative risk (p=0·17). Self-reported adherence was 96% in the 7-day-dose group and 99% in the single-dose group. Side-effects were similar by group; the most common side-effect was nausea (124 [23%]), followed by headache (38 [7%]) and vomiting (19 [4%]).

INTERPRETATION

The 7-day-dose metronidazole should be the preferred treatment for trichomoniasis among women.

FUNDING

National Institutes of Health.

Molecular Diagnosis of Bacterial Vaginosis: an Update

Bacterial vaginosis (BV) is the most common cause of vaginal discharge in reproductive-age women. BV has been associated with poor reproductive outcomes such as preterm delivery, the acquisition of sexually transmitted infections, including HIV, and pelvic inflammatory disease. BV represents the acquisition of a diverse community of anaerobic and facultative bacteria and a reduction in lactobacilli. It can be diagnosed using several tests ranging from clinical indicators, point-of-care tests, and molecular assays. Molecular technologies are objective, are able to detect fastidious bacteria, enable quantitation, and are ideal for self-collected vaginal swabs. This paper reviews the currently available BV diagnostic tests in the United States.

Human papillomaviruses in Western Africa: prevalences and risk factors in Burkina Faso

PURPOSE

Cervical cancer is the most common cancer in women in low income countries. Certain oncogenic types of human papillomaviruses are causally associated with the cervical cancer. To ensure effective primary prevention through the introduction of a national vaccination program in Burkina Faso, information about the disease burden of HPV infection in the country is of great importance.

METHODS

In the present work the prevalence of 54 different HPV types and 18 other sexually transmitted infection as well as the predominant risk factors for the development of cervical cancer were investigated in Ouagadougou. A cross-sectional study on two populations without (n=471) and with known cervical dysplasia (n=39) was carried out between October 2013 and March 2014. Retrospectively, data on possible and secured risk factors of the cervical carcinoma were collected. The participants were examined gynecologically and a vaginal lavage was taken, which was molecular genetically examined for 54 different human papillomavirus genotypes and 18 other STIs.

RESULTS

The prevalence of human papillomavirus was 42.3% (188/444) in the first study population and 87.2% (34/39) in the second study population. The immunization coverage would be 24.5% of the HPV types and 33.9% of the high-risk HPV types with quadrivalent vaccine Gardasil®. The nonavalent vaccine Gardasil®9 (9vHPV) would cover 37.3% of all HPV types and 57.1% of high-risk HPV types.

CONCLUSION

The prevention of infection with human papillomaviruses by vaccination is expected to result in a drastic reduction in the morbidity and mortality of the cervical cancer in Burkina Faso.

Use of copper intrauterine device is not associated with higher bacterial vaginosis prevalence in Thai HIV-positive women

The study assessed and compared bacterial vaginosis (BV) prevalence in Thai women in reproductive age in four study groups - group 1, HIV-positive with copper intrauterine device (Cu-IUD); group 2, HIV-positive without Cu-IUD; group 3, HIV-negative with Cu-IUD; and group 4, HIV-negative without Cu-IUD. We conducted a cross-sectional study. BV prevalence was assessed by Nugent score and Amsel criteria. Descriptive statistics was used to present baseline characteristics; kwallis rank test - to compare variables between the four groups; logistic regression - to assess factors, related to BV prevalence. The analysis included 137 women in the four study groups with a median age of 39 years. Median BV prevalence by Nugent score was 45%, intermediate vaginal flora - 7% and normal vaginal flora - 48%. There was no statistically significant difference in the BV prevalence between the four study groups, p = 0.711. Threefold lower BV prevalence was found, assessed by Amsel criteria compared to Nugent score. Women with body mass index (BMI) < 20 had higher probability to have BV or intermediate vaginal flora, OR = 3.11, 95% CI (1.2-8.6), p = 0.025. The study found a high BV prevalence in the four study groups, related neither to HIV status, nor to Cu-IUD use. BV prevalence was associated only with low BMI. Thus, Cu-IUD could be a good contraceptive choice for HIV-positive women. Research in defining normal vaginal microbiota and improve diagnostic methods for BV should continue.

Prevalence of bacterial vaginosis in pregnant and non-pregnant Iranian women: a systematic review and meta-analysis

PURPOSE

Bacterial vaginosis (BV) is a vaginal disorder which occurs either symptomatic or asymptomatic because of an imbalance between H₂O₂-producing Lactobacillus and Gardnerella vaginalis in the vagina. This systematic review and meta-analysis is the first to determine the prevalence of BV in pregnant and non-pregnant women in Iran.

METHODS

We used national (SID, Irandoc, Iranmedex and Magiran) and international (PubMed, Scopus, Google Scholar and ISI web of knowledge) electronic databases to systematically search and collect available studies using related keywords (up to 1 December 2017). Inclusion and exclusion criteria were defined to select eligible studies.

RESULTS

The overall prevalence of BV among Iranian women was 18.9% (95% CI 14-25). Gardnerella vaginalis was the most prevalent isolated bacteria. The prevalence of BV in non-pregnant women was 28% (95% CI 15.1-45.9) which was higher compared with pregnant women who had a prevalence of 16.5% (95% CI 12.5-21.6).

CONCLUSION

The present review revealed a high prevalence of BV in non-pregnant women. Given that BV is associated with a series of reproductive complications such as infertility, taking preventive measures such as awareness of patients as well as monitoring and controlling of syndrome are essential.

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.

Evaluation of interobserver reliability of Nugent score for diagnosis of bacterial vaginosis

Background

Vaginal discharge is the commonly narrated compliant of the female attendees of sexually transmitted infection clinic, among which bacterial vaginosis (BV) is responsible for one-third of the visits. BV is often diagnosed clinically which warrants laboratory confirmation.

Aims

The study aims to detect the reliability of the Nugent scoring system between observers for the diagnosis of BV.

Materials and Methods

This is a prospective study including 177 high vaginal swabs. The gram-stained smears were examined by three independent microbiologists, and the Nugent scoring was performed. Statistical analysis was performed using IBM-SPSS version-22 statistical package for kappa value.

Results

Concordant results were seen in 64.03% of smears, discordant results were given in 4.51% of smears, and partial agreement was observed in 31.63% of smears.

Conclusion

Interobserver reliability is good for the Nugent score. The Nugent score is a simple and reliable method for the diagnosis of BV that can be adapted even in the resource poor settings.

Comparison of the vaginal environment in rhesus and cynomolgus macaques pre- and post-lactobacillus colonization

BACKGROUND

Rhesus and cynomologus macaques are valuable animal models for the study of human immunodeficiency virus (HIV) prevention strategies. However, for such studies focused on the vaginal route of infection, differences in vaginal environment may have deterministic impact on the outcome of such prevention, providing the rationale for this study.

METHODS

We tested the vaginal environment of rhesus and cynomolgus macaques longitudinally to characterize the normal microflora based on Nugent scores and pH. This evaluation was extended after colonization of the vaginal space with Lactobacilli in an effort to recreate NHP models representing the healthy human vaginal environment.

RESULTS AND CONCLUSION

Nugent scores and pH differed significantly between species, although data from both species were suggestive of stable bacterial vaginosis. Colonization with Lactobacilli was successful in both species leading to lower Nugent score and pH, although rhesus macaques appeared better able to sustain Lactobacillus spp over time.

Correlates of Bacterial Vaginosis Over Long-Term Follow-Up: Impact of HIV Infection

Correlates of bacterial vaginosis (BV) are poorly understood, especially in HIV infection. In a cohort study, HIV-seropositive and comparison seronegative women were assessed every 6 months during 1994-2015. BV was considered present when three of four Amsel criteria were met. Behavioral characteristics were assessed using structured interviews. Multivariable logistic regression used generalized estimating equation models to determine factors associated with BV. Cumulative incidence of BV over time was assessed using the log-rank test. Among 3,730 women (964 HIV seronegative and 2,766 HIV seropositive) contributing 70,970 visits, BV was diagnosed at 2,586 (14.0%) visits by HIV-seronegative women and 6,224 (11.9%) visits by HIV-seropositive women (p < .0001). The cumulative incidence of BV was 530/964 (55.0%) in HIV-seronegative women and 1,287/2,766 (46.5%) in seropositive women (p < .0001). In adjusted analyses, factors associated with BV were younger age, ethnicity, lower income, less education, recruitment site, recruitment in the 2001-2002 cohort, heavier drinking, current smoking, depression, and sex with a male partner; both hormonal contraception and menopause were negatively associated with BV. Of 533 women with prevalent BV, 228 (42.8%) recurred within a year, while persistent BV was found in 12.8% of participants; neither proportion differed by HIV serostatus. Time trends in the proportion of women with BV at any single visit were not identified. BV is common among women with and at risk for HIV, but HIV infection does not predispose to BV, which is associated instead with behavioral and cultural factors.

Changes in vaginal community state types reflect major shifts in the microbiome

Background: Recent studies of various human microbiome habitats have revealed thousands of bacterial species and the existence of large variation in communities of microorganisms in the same habitats across individual human subjects. Previous efforts to summarize this diversity, notably in the human gut and vagina, have categorized microbiome profiles by clustering them into community state types (CSTs). The functional relevance of specific CSTs has not been established.

Objective: We investigate whether CSTs can be used to assess dynamics in the microbiome.

Design: We conduct a re-analysis of five sequencing-based microbiome surveys derived from vaginal samples with repeated measures.

Results: We observe that detection of a CST transition is largely insensitive to choices in methods for normalization or clustering. We find that healthy subjects persist in a CST for two to three weeks or more on average, while those with evidence of dysbiosis tend to change more often. Changes in CST can be gradual or occur over less than one day. Upcoming CST changes and switches to high-risk CSTs can be predicted with high accuracy in certain scenarios. Finally, we observe that presence of Gardnerella vaginalis is a strong predictor of an upcoming CST change.

Conclusion: Overall, our results show that the CST concept is useful for studying microbiome dynamics.

Does the vaginal microbiota play a role in the development of cervical cancer?

Persistent infection with oncogenic human papillomavirus (HPV) is necessary but not sufficient for the development of cervical cancer. The factors promoting persistence as well those triggering carcinogenetic pathways are incompletely understood. Rapidly evolving evidence indicates that the vaginal microbiome (VM) may play a functional role (both protective and harmful) in the acquisition and persistence of HPV, and subsequent development of cervical cancer. The first studies examining the VM and the presence of an HPV infection using next-generation sequencing techniques identified higher microbial diversity in HPV-positive as opposed to HPV-negative women. Furthermore, there appears to be a temporal relationship between the VM and HPV infection in that specific community state types may be correlated with a higher chance of progression or regression of the infection. Studies describing the VM in women with preinvasive disease (squamous intraepithelial neoplasia [SIL]) consistently demonstrate a dysbiosis in women with the more severe disease. Although it is plausible that the composition of the VM may influence the host's innate immune response, susceptibility to infection, and the development of cervical disease, the studies to date do not prove causality. Future studies should explore the causal link between the VM and the clinical outcome in longitudinal samples from existing biobanks.

Multiplex Peptide Nucleic Acid Fluorescence In Situ Hybridization (PNA-FISH) for Diagnosis of Bacterial Vaginosis

Fluorescence in situ hybridization (FISH) is a molecular method used to identify and quantify microorganisms in a wide range of samples. This technique combines the simplicity of microscopic observation and the specificity of DNA/rRNA hybridization, allowing detection of selected bacterial species and morphologic visualization. Here, we describe a quantitative molecular diagnosis of bacterial vaginosis, based on the classical Nugent score. Our probes are able to differentiate Lactobacillus spp. and Gardnerella vaginalis from the other undefined bacterial species considered in the Nugent score.

Molecular diagnosis of bacterial vaginosis: Does adjustment for total bacterial load or human cellular content improve diagnostic performance?

We investigated the utility of quantitative PCR assays for diagnosis of bacterial vaginosis and found that while the best model utilized bacterial copy number adjusted for total bacterial load (sensitivity=98%, specificity=93%, AUC=0.95[95%CI=0.93,0.97]), adjusting for total bacterial or human cell load did not consistently increase the diagnostic performance of the assays.

The vaginal microbiota, human papillomavirus infection and cervical intraepithelial neoplasia: what do we know and where are we going next?

The vaginal microbiota plays a significant role in health and disease of the female reproductive tract. Next-generation sequencing techniques based upon the analysis of bacterial 16S rRNA genes permit in-depth study of vaginal microbial community structure to a level of detail not possible with standard culture-based microbiological techniques. The human papillomavirus (HPV) causes both cervical intraepithelial neoplasia (CIN) and cervical cancer. Although the virus is highly prevalent, only a small number of women have a persistent HPV infection and subsequently develop clinically significant disease. There is emerging evidence which leads us to conclude that increased diversity of vaginal microbiota combined with reduced relative abundance of Lactobacillus spp. is involved in HPV acquisition and persistence and the development of cervical precancer and cancer. In this review, we summarise the current literature and discuss potential mechanisms for the involvement of vaginal microbiota in the evolution of CIN and cervical cancer. The concept of manipulation of vaginal bacterial communities using pre- and probiotics is also discussed as an exciting prospect for the field of cervical pathology.

The Human Microbiome during Bacterial Vaginosis

Bacterial vaginosis (BV) is the most commonly reported microbiological syndrome among women of childbearing age. BV is characterized by a shift in the vaginal flora from the dominant Lactobacillus to a polymicrobial flora. BV has been associated with a wide array of health issues, including preterm births, pelvic inflammatory disease, increased susceptibility to HIV infection, and other chronic health problems. A number of potential microbial pathogens, singly and in combinations, have been implicated in the disease process. The list of possible agents continues to expand and includes members of a number of genera, including Gardnerella, Atopobium, Prevotella, Peptostreptococcus, Mobiluncus, Sneathia, Leptotrichia, Mycoplasma, and BV-associated bacterium 1 (BVAB1) to BVAB3. Efforts to characterize BV using epidemiological, microscopic, microbiological culture, and sequenced-based methods have all failed to reveal an etiology that can be consistently documented in all women with BV. A careful analysis of the available data suggests that what we term BV is, in fact, a set of common clinical signs and symptoms that can be provoked by a plethora of bacterial species with proinflammatory characteristics, coupled to an immune response driven by variability in host immune function.

Risk assessment and management to prevent preterm birth

Preterm birth is the most important cause of neonatal mortality and morbidity worldwide. In this review, we review potential risk factors associated with preterm birth and the subsequent management to prevent preterm birth in low and high risk women with a singleton or multiple pregnancy. A history of preterm birth is considered the most important risk factor for preterm birth in subsequent pregnancy. General risk factors with a much lower impact include ethnicity, low socio-economic status, maternal weight, smoking, and periodontal status. Pregnancy-related characteristics, including bacterial vaginosis and asymptomatic bacteriuria, appear to be of limited value in the prediction of preterm birth. By contrast, a mid-pregnancy cervical length measurement is independently associated with preterm birth and could be used to identify women at risk of a premature delivery. A fetal fibronectin test may be of additional value in the prediction of preterm birth. The most effective methods to prevent preterm birth depend on the obstetric history, which makes the identification of women at risk of preterm birth an important task for clinical care providers.

Motivations for Intravaginal Product Use among a Cohort of Women in Los Angeles

OBJECTIVE

Intravaginal practices-including behaviors such as intravaginal cleansing and insertion of products-have been linked to a number of adverse reproductive health outcomes, including increased risk for bacterial vaginosis, sexually transmitted infections, and HIV. Currently, little is known about the motivations for intravaginal practices among women in the United States. The objective of this study was to identify and describe motivations for intravaginal washing and intravaginal insertion of products among women of differing ages and racial/ethnic groups.

METHODS

Between 2008 and 2010, we enrolled a convenience sample of sexually active women aged 18-65 years living in Los Angeles recruited through community education and outreach activities in HIV/AIDS service organizations, women's health clinics, community-based organizations, and HIV testing sites. At the enrollment visit, women completed a self-administered, computer-assisted questionnaire covering demographics, sexual behaviors, intravaginal practices, and motivations for intravaginal practices over the past month and past year.

RESULTS

We enrolled 141 women; 34% of participants were Caucasian, 40% African American, and 26% Latina. Peri-sexual intravaginal washing was common in all groups, whether to clean up after sex (70%) or to prepare for sex (54%). African American women were more likely to report learning to wash intravaginally from their mothers compared to Latina or Caucasian women (70% vs. 49%, P = 0.04). Sixty-one percent of African American women reported using a douching device over the past year compared to 41% of Latina and 40% of Caucasian women (p = 0.02). Younger women were more likely to report that their male partners wanted them to wash intravaginally than older women (77% vs. 24%, P<0.01), and more likely to report the removal of odors as a motive than older women (65% vs. 40%, P = 0.04). The most commonly used intravaginal products included sexual lubricants, petroleum jelly, body lotions, oils, and wet wipes. Use of these products varied by race, and motives given included increasing lubrication, preparing for sex, smelling good, and preventing sexually transmitted infections.

CONCLUSION

Women's intravaginal practices and motivations for these practices differ across race and age. Motivations for use also vary by type of intravaginal product used. Given that some intravaginal practices have been shown to be harmful, interventions, programs and counseling messages to encourage less harmful practices are needed, and should consider underlying motivations that influence women's vaginal practices. Practitioners may use these results to better support women in achieving vaginal health.

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.

Factors Associated with Bacterial Vaginosis among Women Who Have Sex with Women: A Systematic Review

BACKGROUND

Women who have sex with women (WSW) have a higher burden of bacterial vaginosis (BV) than heterosexual women; studies of risk factors specific to this population are limited. We summarised current knowledge regarding risk factors for BV among WSW by systematic review.

METHODS

This systematic review was conducted according to the PRISMA statement. PUBMED, EMBASE, Web of Science and The Cochrane Library were searched to 31st December, 2014.

INCLUSION CRITERIA

1) WSW included in the study population; 2) accepted BV diagnostic method; 3) investigated or could extrapolate factors(s) associated with BV acquisition, persistence or transmission in WSW specifically by comparing BV positive to BV negative women. Search was limited to English-language publications.

RESULTS

A limited number of studies have investigated BV in WSW. Of 71 unique references, 18 full-text articles were assessed and 14 studies fulfilled inclusion criteria. BV was positively associated with higher numbers of female partners, both lifetime and in the three months prior to diagnosis, and confirmed BV in a female partner, but inconsistently associated with partners' BV history or symptoms. BV was not associated with ethnicity, vaginal douching or hormonal contraception. The impact of specific sexual activities, male sexual contact, smoking and the menstrual cycle varied considerably between study populations.

CONCLUSION

BV in WSW is associated with increased numbers of recent and past female partners and confirmed BV in a female partner. There are limited studies of BV in WSW populations, and research is needed to further elucidate risk factors for BV among WSW. However these data provide epidemiological evidence that BV risk in women is directly related to exposure to other female partners and a partner with BV, providing support for the concept that BV is likely to be transmitted between women.

SYSTEMATIC REVIEW REGISTRATION NUMBER

CRD42014009536 (PROSPERO).

A cross-sectional study on the relationship of age, gestational age and HIV infection to bacterial vaginosis and genital mycoplasma infection

OBJECTIVES

Pregnant women are especially at risk of developing complications when infected with reproductive tract infections (RTIs). The objective of this study was to determine the prevalence of bacterial vaginosis (BV) and genital mycoplasmas in pregnant women and investigate the associations between BV, genital mycoplasmas, HIV infection, age and gestational age.

DESIGN

Cross-sectional study with descriptive and analytical components.

SETTING

Antenatal clinic of a tertiary academic hospital in South Africa.

PARTICIPANTS

220 pregnant women older than 18 were included in the study and provided self-collected vaginal swabs.

PRIMARY AND SECONDARY OUTCOMES

BV and genital mycoplasma colonisation and/or infection in women of differing age, gestational period and HIV status.

RESULTS

The prevalence of BV was 17.7% (39/220) (95% CI 12.9 to 23.4), intermediate vaginal flora (IVF) 15% (33/220) (95% CI 10.56 to 20.42), and the overall prevalence of genital mycoplasmas was 84% (185/220) (95% CI 78.47 to 88.58). BV was significantly associated with HIV infection with an OR of 2.84 (95% CI 1.08 to 7.46 and p value=0.034). However, BV was inversely associated with gestational age with an OR of 0.08 (95% CI 0.01 to 0.42 and p value=0.003) for second trimester pregnancies and an OR of 0.03 (95% CI 0.01 to 0.17 and p value<0.001) for third trimester pregnancies using the first trimester as reference. IVF was significantly associated with HIV infection with an OR of 2.7 (95% CI 1.07 to 6.79 and p value=0.035) but not with age or gestational age. Genital mycoplasmas were not significantly associated with age, gestational age, HIV status, BV flora or IVF.

CONCLUSIONS

The high infection rate of genital mycoplasmas and the association of BV with HIV found in this study reiterate the importance of screening for these RTIs in high-risk groups such as pregnant women.

A multi-platform metabolomics approach identifies highly specific biomarkers of bacterial diversity in the vagina of pregnant and non-pregnant women

Bacterial vaginosis (BV) increases transmission of HIV, enhances the risk of preterm labour, and is associated with malodour. Clinical diagnosis often relies on microscopy, which may not reflect the microbiota composition accurately. We use an untargeted metabolomics approach, whereby we normalize the weight of samples prior to analysis, to obtained precise measurements of metabolites in vaginal fluid. We identify biomarkers for BV with high sensitivity and specificity (AUC = 0.99) in a cohort of 131 pregnant and non-pregnant Rwandan women, and demonstrate that the vaginal metabolome is strongly associated with bacterial diversity. Metabolites associated with high diversity and clinical BV include 2-hydroxyisovalerate and γ-hydroxybutyrate (GHB), but not succinate, which is produced by both Lactobacillus crispatus and BV-associated anaerobes in vitro. Biomarkers associated with high diversity and clinical BV are independent of pregnancy status, and were validated in a blinded replication cohort from Tanzania (n = 45), where we predicted clinical BV with 91% accuracy. Correlations between the metabolome and microbiota identified Gardnerella vaginalis as a putative producer of GHB, and we demonstrate production by this species in vitro. This work illustrates how changes in community structure alter the chemical composition of the vagina, and identifies highly specific biomarkers for a common condition.

Characterization of the Genital Microenvironment of Female Rhesus Macaques Prior to and After SIV Infection

PROBLEM

HIV infection among women is frequently modeled in female rhesus macaques. Longitudinal studies on genital compartment and hormonal factors that can influence susceptibility to SIV infection are lacking in this animal model.

METHOD OF STUDY

Genital specimens and menstruation of indoor-housed female rhesus macaques were analyzed prior to and after SIV infection.

RESULTS

Median menstrual cycle length averaged 27 days, although highly variable cycle lengths and frequent periods of amenorrhea were observed during summer months. The vaginal microbiota, characterized by adapted Nugent scoring, showed predominance of small Gram-variable rods and Gram-positive cocci. Highly variable vaginal cytokine levels were observed pre- and post-SIV infection. Vaginal viral loads correlated with plasma viral loads, but were not associated with progesterone levels.

CONCLUSION

These results provide an integrated characterization of important factors in the vaginal microenvironment that are relevant to the experimental design of HIV prevention and transmission studies in female rhesus macaques.

A Phase 3, Multicenter, Randomized, Double-Blind, Vehicle-Controlled Study Evaluating the Safety and Efficacy of Metronidazole Vaginal Gel 1.3% in the Treatment of Bacterial Vaginosis

BACKGROUND

Bacterial vaginosis (BV), a prevalent infection in women of reproductive age, is associated with increased risk of upper genital tract and sexually transmitted infections, and complications in pregnancy. Currently approved treatments include metronidazole, which requires once or twice daily intravaginal administration for 5 days or twice daily oral administration for 7 days. This phase 3 study determined the safety and efficacy of single-dose metronidazole vaginal gel (MVG) 1.3%.

METHODS

In this double-blind, vehicle-controlled study, 651 women with clinical diagnosis of BV were randomized 1:1 to receive MVG 1.3% or vehicle vaginal gel. Primary efficacy measure was clinical cure (normal discharge, negative "whiff test," and <20% clue cells) at day 21. Secondary measures included therapeutic cure (both clinical and bacteriological; day 21) and bacteriologic cure (Nugent score <4), clinical cure, and time to resolution of symptoms (day 7).

RESULTS

A total of 487 participants were included in the primary analysis. Clinical and therapeutic cure rates (day 21) were higher in participants treated with MVG 1.3% compared with vehicle gel (37.2% vs. 26.6% [P = 0.010] and 16.8% vs. 7.2% [P = 0.001], respectively). Clinical and bacteriologic cure rates (day 7) were also higher in the MVG 1.3% group (46.0% vs. 20.0% [P < 0.001] and 32.7% vs. 6.3% [P < 0.001], respectively). The median time to resolution of symptoms was shorter in the MVG 1.3% (day 6) than vehicle group (not reached). No serious adverse events were reported, and incidence was similar across treatment groups.

CONCLUSIONS

Single-dose MVG 1.3% was safe and superior to vehicle gel in producing cure among women with BV.

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.

Proposal of a new cutoff for Nugent criteria in the diagnosis of bacterial vaginosis

OBJECTIVES

Treatment for lower genital tract infections is the major demand for gynecological services in public and private health centers in Brazil. The aims of this study were to evaluate the diagnostic resources proposed by Amsel, comparing them with the microflora evaluation by the Nugent score and thus propose a new cutoff point in this rating score, showing the complementarity of both diagnostic criteria.

METHODS

A total of 136 female patients aged between 18 and 69years were evaluated and had their vaginal discharge samples collected.

RESULTS

Diagnosis based on the isolated analysis of the Amsel's criteria may lead clinicians to apply inadequate treatment techniques. When patients were evaluated according to the Amsel criteria, it was seen that the presence of clue cells had a higher Kappa index in the vaginosis diagnosis; when patients were distributed according to the Nugent criteria in relation to each Amsel criterion, it was observed that clue cells differentiate positive patients more efficiently than the Nugent criteria. In the proposed cutoff point, the identification of clue cells complied with pH alterations. It also complied with the positive Nugent score (≥7). However, when clue cells were analyzed by both Amsel and Nugent methods, the diagnostic conclusion was reached once this was the parameter with a higher Kappa value.

CONCLUSION

The Amsel method could be used as a screening tool whereas the Nugent score could serve as a confirmatory resource of diagnosis, considering a new assessment cutoff point (negative 0-6 and positive ≥7).

Diagnosis of bacterial vaginosis by a new multiplex peptide nucleic acid fluorescence in situ hybridization method

Bacterial vaginosis (BV) is one of most common vaginal infections. However, its diagnosis by classical methods reveals low specificity. Our goal was to evaluate the accuracy diagnosis of 150 vaginal samples with research gold standard methods and our Peptide Nucleic Acid (PNA) probes by Fluorescence in situ Hybridization (FISH) methodology. Also, we described the first PNA-FISH methodology for BV diagnosis, which provides results in approximately 3 h. The results showed a sensitivity of 84.6% (95% confidence interval (CI), from 64.3 to 95.0%) and a specificity of 97.6% (95% CI [92.6-99.4%]), demonstrating the higher specificity of the PNA-FISH method and showing false positive results in BV diagnosis commonly obtained by the classical methods. This methodology combines the specificity of PNA probes for Lactobacillus species and G. vaginalis visualization and the calculation of the microscopic field by Nugent score, allowing a trustful evaluation of the bacteria present in vaginal microflora and avoiding the occurrence of misleading diagnostics. Therefore, the PNA-FISH methodology represents a valuable alternative for BV diagnosis.

A blinded, randomized controlled trial of high-dose vitamin D supplementation to reduce recurrence of bacterial vaginosis

OBJECTIVE

Low serum vitamin D levels have been associated with increased prevalence of the reproductive tract condition bacterial vaginosis (BV). The objective of this trial was to evaluate the effect of high-dose vitamin D supplementation on BV recurrence.

STUDY DESIGN

This randomized, placebo-controlled, double-blinded trial enrolled 118 women with symptomatic BV from an urban sexually transmitted disease clinic (clinicaltrials.gov registration NCT01450462). All participants received 500 mg of oral metronidazole twice daily for 7 days. Intervention participants (n = 59) also received 9 doses of 50,000 IU of cholecalciferol (vitamin D3) over 24 weeks; control women (n = 59) received matching placebo. Recurrent BV was assessed via Nugent scoring after 4, 12, and 24 weeks. We assessed the effect of the intervention using an intention-to-treat approach, fitting Cox proportional hazards models to evaluate recurrent BV over the follow-up period.

RESULTS

Most participants (74%) were black, with a median age of 26 years. Median presupplementation serum 25-hydroxyvitamin D [25(OH)D] was similar across randomization arms: 16.6 ng/mL in the vitamin D arm and 15.8 ng/mL in the control arm. At trial completion, median 25(OH)D among women receiving vitamin D was 30.5 ng/mL, vs 17.8 ng/mL in control women; 16% of women receiving vitamin D and 57% receiving placebo remained vitamin D deficient (<20 ng/mL). BV prevalence among women randomized to vitamin D was very similar to those randomized to placebo at the 4- and 12-week visits, but by the 24-week visit, BV prevalence was 65% among women in the vitamin D arm and 48% among control women. BV recurrence was not reduced by vitamin D supplementation (intention-to-treat hazard ratio, 1.11; 95% confidence interval, 0.68-1.81). Among women experiencing recurrent BV, median time to recurrence was 13.7 weeks in the vitamin D arm and 14.3 weeks in the control arm.

CONCLUSION

Women receiving vitamin D experienced significant increases in serum 25(OH)D, but this increase was not associated with decreased BV recurrence in this high-risk sexually transmitted disease clinic population.

An emerging mycoplasma associated with trichomoniasis, vaginal infection and disease

Humans are colonized by thousands of bacterial species, but it is difficult to assess the metabolic and pathogenic potential of the majority of these because they have yet to be cultured. Here, we characterize an uncultivated vaginal mycoplasma tightly associated with trichomoniasis that was previously known by its 16S rRNA sequence as "Mnola." In this study, the mycoplasma was found almost exclusively in women infected with the sexually transmitted pathogen Trichomonas vaginalis, but rarely observed in women with no diagnosed disease. The genomes of four strains of this species were reconstructed using metagenome sequencing and assembly of DNA from four discrete mid-vaginal samples, one of which was obtained from a pregnant woman with trichomoniasis who delivered prematurely. These bacteria harbor several putative virulence factors and display unique metabolic strategies. Genes encoding proteins with high similarity to potential virulence factors include two collagenases, a hemolysin, an O-sialoglycoprotein endopeptidase and a feoB-type ferrous iron transport system. We propose the name "Candidatus Mycoplasma girerdii" for this potential new pathogen.

Bead-based multiplex sexually transmitted infection profiling

OBJECTIVES

Sexually transmitted infections are a significant cause of genital disease, infertility and hospital admissions. The economic impact is high. An accurate diagnosis is often difficult and time consuming. We report the development and validation of a novel bead-based multiplex sexually transmitted infection profiling (STIP) assay that detects 18 sexually transmitted infections using a multiplex PCR followed by Luminex bead-based hybridisation.

METHODS

STIP was validated using urogenital samples pretested by commercially available quantitative PCR, microscopy or by culturing methods.

RESULTS

STIP specifically detects Chlamydia trachomatis, Herpes simplex virus 1 and 2, Treponema pallidum, Trichomonas vaginalis, Neisseria gonorrhoeae, Mycoplasma (M.) genitalium, M. hominis, M. pneumonia, M. spermatophilum, Ureaplasma urealyticum and U. parvum, and quantifies bacterial vaginosis-associated Atopobium vaginae and Gardnerella vaginalis as well as three Candida species and normal genital flora-associated Lactobacillus species. STIP reached an overall concordance of 95-100% with commercially available quantitative PCR tests. Compared to Nugent score, STIP reached a sensitivity of 95% and a specificity of 86% for bacterial vaginosis detection. Candida specimens, pretested by direct culturing, were identified with a sensitivity of 97% and a specificity of 99%.

CONCLUSIONS

STIP is a powerful high-throughput tool in assessing a broad spectrum of urogenital infections.

The composition and stability of the vaginal microbiota of normal pregnant women is different from that of non-pregnant women

BACKGROUND

This study was undertaken to characterize the vaginal microbiota throughout normal human pregnancy using sequence-based techniques. We compared the vaginal microbial composition of non-pregnant patients with a group of pregnant women who delivered at term.

RESULTS

A retrospective case-control longitudinal study was designed and included non-pregnant women (n = 32) and pregnant women who delivered at term (38 to 42 weeks) without complications (n = 22). Serial samples of vaginal fluid were collected from both non-pregnant and pregnant patients. A 16S rRNA gene sequence-based survey was conducted using pyrosequencing to characterize the structure and stability of the vaginal microbiota. Linear mixed effects models and generalized estimating equations were used to identify the phylotypes whose relative abundance was different between the two study groups. The vaginal microbiota of normal pregnant women was different from that of non-pregnant women (higher abundance of Lactobacillus vaginalis, L. crispatus, L. gasseri and L. jensenii and lower abundance of 22 other phylotypes in pregnant women). Bacterial community state type (CST) IV-B or CST IV-A characterized by high relative abundance of species of genus Atopobium as well as the presence of Prevotella, Sneathia, Gardnerella, Ruminococcaceae, Parvimonas, Mobiluncus and other taxa previously shown to be associated with bacterial vaginosis were less frequent in normal pregnancy. The stability of the vaginal microbiota of pregnant women was higher than that of non-pregnant women; however, during normal pregnancy, bacterial communities shift almost exclusively from one CST dominated by Lactobacillus spp. to another CST dominated by Lactobacillus spp.

CONCLUSION

We report the first longitudinal study of the vaginal microbiota in normal pregnancy. Differences in the composition and stability of the microbial community between pregnant and non-pregnant women were observed. Lactobacillus spp. were the predominant members of the microbial community in normal pregnancy. These results can serve as the basis to study the relationship between the vaginal microbiome and adverse pregnancy outcomes.

Multiplex quantitative polymerase chain reaction assay for the identification and quantitation of major vaginal lactobacilli

Lactobacilli play a key role in promoting vaginal health. Depletion of these bacteria is associated with bacterial vaginosis (BV), the most common vaginal disorder. Here we describe the development and laboratory validation of a novel single-tube multiplex TaqMan quantitative polymerase chain reaction (qPCR) assay for the identification and quantitative assessment of the four major vaginal Lactobacillus species: L. crispatus, L. jensenii, L. gasseri, and L. iners. The assay utility was evaluated by the analysis of lactobacilli in non-cultured clinical vaginal swab specimens collected from BV patients and healthy individuals. As confirmed by the assay, L. crispatus, L. jensenii, and to a lesser extent L. gasseri, are common in the vagina of healthy women, whereas L. iners dominance is associated with BV. The major assay limitation was preferential detection of dominant Lactobacillus species in samples with mixed lactobacilli resulting in lower sensitivity for minor species. The multiplex qPCR assay described here is an advance in the detection and quantitation of the major vaginal lactobacilli, potentially facilitating the molecular diagnosis of BV and post-therapy restoration of the vaginal microflora.

Longitudinal analysis of vaginal microbiome dynamics in women with recurrent bacterial vaginosis: recognition of the conversion process

Bacterial vaginosis (BV) affects ∼ 30% of women of reproductive age, has a high rate of recurrence, and is associated with miscarriage, preterm birth, and increased risk of acquiring other sexually transmitted infections, including HIV-1. Little is known of the daily changes in the vaginal bacterial composition as it progresses from treatment to recurrence, or whether any of these might be useful in its prediction or an understanding of its causes. We used phylogenetic branch-inclusive quantitative PCR (PB-qPCR) and Lactobacillus blocked/unblocked qPCR (Lb-qPCR) to characterize longitudinal changes in the vaginal microbiota in sequential vaginal self-swabs from five women with recurrent BV, from diagnosis through remission to recurrence. Both patients with acute BV samples dominated by G. vaginalis recurred during the study with similar profiles, whereas the three patients with acute BV samples dominated by other anaerobes did not recur or recurred to an intermediate Nugent score. L. iners dominated remission phases, with intermittent days of abnormal microbial profiles typically associated with menses. The exception was a newly discovered phenomenon, a sustained period of abnormal profiles, termed conversion, which preceded symptomatic acute BV. Species known to have antagonistic activity towards Lactobacillus were detected in pre-conversion samples, possibly contributing to the decline in Lactobacillus. Lb-qPCR scores define two categories of response in the initial post-treatment visit samples; scores <5 may correspond with poor response to treatment or rapid recurrence, whereas scores >8 may predict delayed or no recurrence. Amsel criteria or Nugent scores did not have this potential predictive capability. Larger studies are warranted to evaluate the prognostic potential of detecting conversion and poor Lb-qPCR scores at the post-treatment visit of recurrent BV patients.

Composition of the vaginal microbiota in women of reproductive age--sensitive and specific molecular diagnosis of bacterial vaginosis is possible?

BACKGROUND AND OBJECTIVE

Bacterial vaginosis (BV) is the most common vaginal disorder, characterized by depletion of the normal lactobacillus-dominant microbiota and overgrowth of commensal anaerobic bacteria. This study aimed to investigate the composition of the vaginal microbiota in women of reproductive age (healthy women and women with BV), with the view of developing molecular criteria for BV diagnosis.

MATERIALS AND METHODS

Vaginal samples from 163 women (79 control, 73 BV and 11 intermediate (Lactobacillary grade II flora) cases) were analyzed using 454 pyrosequencing of the hypervariable regions V3-V4 of the 16S rRNA gene and 16 quantitative bacterial species/genus-specific real-time PCR assays. Sensitivities and specificities of potential BV markers were computed using the Amsel criteria as reference standard for BV. The use of quantitative thresholds for prediction of BV, determined for both relative abundance measured with 454 pyrosequencing and bacterial load measured with qPCR, was evaluated.

RESULTS

Relative to the healthy women, the BV patients had in their vaginal microbiota significantly higher prevalence, loads and relative abundances of the majority of BV associated bacteria. However, only Gardnerella vaginalis, Atopobium vaginae, Eggerthella, Prevotella, BVAB2 and Megasphaera type 1 detected at or above optimal thresholds were highly predictable for BV, with the best diagnostic accuracy shown for A. vaginae. The depletion of Lactobacillus species combined with the presence of either G. vaginalis or A. vaginae at diagnostic levels was a highly accurate BV predictor.

CONCLUSIONS

Quantitative determination of the presence of G. vaginalis, A. vaginae, Eggerthella, Prevotella, BVAB2 and Megasphaera type 1 as well as the depletion of Lactobacillus was highly accurate for BV diagnosis. Measurements of abundance of normal and BV microbiota relative to total bacteria in vaginal fluid may provide more accurate BV diagnosis, and be used for test-of-cure, rather than qualitative detection or absolute counts of BV related microorganisms.

DNase inhibits Gardnerella vaginalis biofilms in vitro and in vivo

Bacterial vaginosis is a highly prevalent and poorly understood polymicrobial disorder of the vaginal microbiota, with significant adverse sequelae. Gardnerella vaginalis predominates in bacterial vaginosis. Biofilms of G. vaginalis are present in human infections and are implicated in persistent disease, treatment failure, and transmission. Here we demonstrate that G. vaginalis biofilms contain extracellular DNA, which is essential to their structural integrity. Enzymatic disruption of this DNA specifically inhibits biofilms, acting on both newly forming and established biofilms. DNase liberates bacteria from the biofilm to supernatant fractions and potentiates the activity of metronidazole, an antimicrobial agent used in the treatment of bacterial vaginosis. Using a new murine vaginal colonization model for G. vaginalis, we demonstrate >10-fold inhibition of G. vaginalis colonization by DNase. We conclude that DNase merits investigation as a potential nonantibiotic adjunct to existing bacterial vaginosis therapies in order to decrease the risk of chronic infection, recurrence, and associated morbidities.

A multi-omic systems-based approach reveals metabolic markers of bacterial vaginosis and insight into the disease

BACKGROUND

Bacterial vaginosis (BV) is the most common vaginal disorder of reproductive-age women. Yet the cause of BV has not been established. To uncover key determinants of BV, we employed a multi-omic, systems-biology approach, including both deep 16S rRNA gene-based sequencing and metabolomics of lavage samples from 36 women. These women varied demographically, behaviorally, and in terms of health status and symptoms.

PRINCIPAL FINDINGS

16S rRNA gene-based community composition profiles reflected Nugent scores, but not Amsel criteria. In contrast, metabolomic profiles were markedly more concordant with Amsel criteria. Metabolomic profiles revealed two distinct symptomatic BV types (SBVI and SBVII) with similar characteristics that indicated disruption of epithelial integrity, but each type was correlated to the presence of different microbial taxa and metabolites, as well as to different host behaviors. The characteristic odor associated with BV was linked to increases in putrescine and cadaverine, which were both linked to Dialister spp. Additional correlations were seen with the presence of discharge, 2-methyl-2-hydroxybutanoic acid, and Mobiluncus spp., and with pain, diethylene glycol and Gardnerella spp.

CONCLUSIONS

The results not only provide useful diagnostic biomarkers, but also may ultimately provide much needed insight into the determinants of BV.

Understanding vaginal microbiome complexity from an ecological perspective

The various microbiota normally associated with the human body have an important influence on human development, physiology, immunity, and nutrition. This is certainly true for the vagina wherein communities of mutualistic bacteria constitute the first line of defense for the host by excluding invasive, nonindigenous organisms that may cause disease. In recent years much has been learned about the bacterial species composition of these communities and how they differ between individuals of different ages and ethnicities. A deeper understanding of their origins and the interrelationships of constituent species is needed to understand how and why they change over time or in response to changes in the host environment. Moreover, there are few unifying theories to explain the ecological dynamics of vaginal ecosystems as they respond to disturbances caused by menses and human activities such as intercourse, douching, and other habits and practices. This fundamental knowledge is needed to diagnose and assess risk to disease. Here we summarize what is known about the species composition, structure, and function of bacterial communities in the human vagina and the applicability of ecological models of community structure and function to understanding the dynamics of this and other ecosystems that comprise the human microbiome.

Quantification of bacterial species of the vaginal microbiome in different groups of women, using nucleic acid amplification tests

Background

The vaginal microbiome plays an important role in urogenital health. Quantitative real time Polymerase Chain Reaction (qPCR) assays for the most prevalent vaginal Lactobacillus species and bacterial vaginosis species G. vaginalis and A. vaginae exist, but qPCR information regarding variation over time is still very limited. We set up qPCR assays for a selection of seven species and defined the temporal variation over three menstrual cycles in a healthy Caucasian population with a normal Nugent score. We also explored differences in qPCR data between these healthy women and an ‘at risk’ clinic population of Caucasian, African and Asian women with and without bacterial vaginosis (BV), as defined by the Nugent score.

Results

Temporal stability of the Lactobacillus species counts was high with L. crispatus counts of 10⁸ copies/mL and L. vaginalis counts of 10⁶ copies/mL. We identified 2 types of ‘normal flora’ and one ‘BV type flora’ with latent class analysis on the combined data of all women. The first group was particularly common in women with a normal Nugent score and was characterized by a high frequency of L. crispatus, L. iners, L. jensenii, and L. vaginalis and a correspondingly low frequency of L. gasseri and A. vaginae. The second group was characterized by the predominance of L. gasseri and L. vaginalis and was found most commonly in healthy Caucasian women. The third group was commonest in women with a high Nugent score but was also seen in a subset of African and Asian women with a low Nugent score and was characterized by the absence of Lactobacillus species (except for L. iners) but the presence of G. vaginalis and A. vaginae.

Conclusions

We have shown that the quantification of specific bacteria by qPCR contributes to a better description of the non-BV vaginal microbiome, but we also demonstrated that differences in populations such as risk and ethnicity also have to be taken into account. We believe that our selection of indicator organisms represents a feasible strategy for the assessment of the vaginal microbiome and could be useful for monitoring the microbiome in safety trials of vaginal products.

Development and validation of a semiquantitative, multitarget PCR assay for diagnosis of bacterial vaginosis

Quantitative PCR assays were developed for 4 organisms reported previously to be useful positive indicators for the diagnosis of bacterial vaginosis (BV)--Atopobium vaginae, Bacterial Vaginosis-Associated Bacterium 2 (BVAB-2), Gardnerella vaginalis, and Megasphaera-1--and a single organism (Lactobacillus crispatus) that has been implicated as a negative indicator for BV. Vaginal samples (n = 169), classified as positive (n = 108) or negative (n = 61) for BV based on a combination of the Nugent Gram stain score and Amsel clinical criteria, were analyzed for the presence and quantity of each of the marker organisms, and the results were used to construct a semiquantitative, multiplex PCR assay for BV based on detection of 3 positive indicator organisms (A. vaginae, BVAB-2, and Megasphaera-1) and classification of samples using a combinatorial scoring system. The prototype BV PCR assay was then used to analyze the 169-member developmental sample set and, in a prospective, blinded manner, an additional 227 BV-classified vaginal samples (110 BV-positive samples and 117 BV-negative samples). The BV PCR assay demonstrated a sensitivity of 96.7% (202/209), a specificity of 92.2% (153/166), a positive predictive value of 94.0%, and a negative predictive value of 95.6%, with 21 samples (5.3%) classified as indeterminate for BV. This assay provides a reproducible and objective means of evaluating critical components of the vaginal microflora in women with signs and symptoms of vaginitis and is comparable in diagnostic accuracy to the conventional gold standard for diagnosis of BV.

Biotypes and virulence factors of Gardnerella vaginalis isolated from cases of bacterial vaginosis

The present study was conducted to correlate the biotypes of Gardnerella vaginalis strains isolated from cases of bacterial vaginosis and their virulence factors. Thirty-two strains of G. vaginalis isolated from cases of bacterial vaginosis were biotyped. Adherence to vaginal epithelial cells, biofilm production, surface hydrophobicity, phospholipase C and protease activity were tested on these isolates. Biotype 1 was the most prevalent (8; 25%), followed by biotype 2 (7; 21.9%) and biotypes 5 and 8 (5; 15.6%). We did not find any statistical correlation between G. vaginalis biotypes and its virulence factors. Virulence factors expressed by G. vaginalis were not associated with a single biotype.

The association of HIV status with bacterial vaginosis and vitamin D in the United States

OBJECTIVE

To estimate the association between vitamin D deficiency and bacterial vaginosis (BV) among nonpregnant HIV-infected and uninfected women.

METHODS

In a substudy of the Women's Interagency HIV Study, including women from Chicago and New York, the association between BV and vitamin D deficiency, demographics, and disease characteristics was tested using generalized estimating equations. Deficiency was defined as <20 ng/mL 25 (OH) vitamin D and insufficiency as >20 and ≤30 ng/mL. BV was defined by the Amsel criteria.

RESULTS

Among 602 observations of nonpregnant women (480 HIV infected and 122 uninfected), BV was found in 19%. Vitamin D deficiency was found in 59.4%, and insufficiency was found in 24.4%. In multivariable analysis, black race was the most significant predictor of BV (adjusted odds ratio [AOR] 5.90, (95% confidence interval [CI] 2.52-13.8). Vitamin D deficiency was independently associated with BV among HIV-infected women (AOR 3.12, 95% CI 1.16-8.38) but not among HIV-uninfected women. There was a negative linear correlation between vitamin D concentration and prevalence of BV in HIV-infected women (r=-0.15, p=0.001).

CONCLUSIONS

Vitamin D deficiency was very common in this cohort and significantly associated with BV among HIV-infected women. These preliminary findings suggest that further epidemiologic and mechanistic exploration of the relationship between vitamin D and BV in HIV-infected women is warranted.

Quantitative and qualitative correlates of cervicovaginal herpes simplex virus type 2 shedding among HIV-infected women in the Women's Interagency HIV Study

We identified demographic, clinical and biological determinants of herpes simplex virus type 2 (HSV-2) shedding among HIV-infected participants in the Women's HIV Interagency Study (WIHS). Cervicovaginal lavage (CVL) specimens from 369 HIV-infected HSV seropositive women were tested with TaqMan polymerase chain reaction (PRC) for detection HSV-2 DNA. Seven percent of women tested positive for HSV-2 DNA in CVL. Significant correlates of the presence of HSV-2 DNA in CVL were being younger, African American or Hispanic race/ethnicity and injecting drugs in the past six months (P < 0.05). A borderline significant trend for reduced viral shedding with higher CD4+ T cell counts was observed (P = 0.08). All women who were never observed with any genital lesions and had consistently negative self-reported history of genital sores throughout the follow-up (n = 29, 8%) were negative for CVL HSV-2 DNA. HSV-2 DNA quantity was significantly associated with having frequent subsequent lesion recurrences (Spearman rho = 0.48, P = 0.016; adjusted prevalence ratio [APR] = 2.5, P = 0.012). Increasing the age of the host was inversely correlated with decreased viral shedding over time. However, a subset of older women continued to shed significant amounts of virus despite passage of time. This study provides genital HSV-2 DNA titre as a quantitative and symptom- and sign-based measures as qualitative predictors of HSV-2 shedding from the lower genital tract among HIV-infected women.