Severity of bacterial vaginosis and the risk of sexually transmitted infection

Efficacy and acceptability of a self-collected medical grade tampon as a novel vaginal sample collection tool for the detection of HPV and STIs

OBJECTIVE

Cervical cancer remains a significant health concern, particularly in low-income and middle-income countries (LMICs). This study aims to compare the efficacy and suitability of a self-collected tampon for the detection of human papillomavirus (HPV) and sexually transmitted infections (STIs) using qualitative TMA-based assays (Transcription Mediated Amplification; APTIMA® HPV, APTIMA® Combo 2 (CT/NG; AC2 from now on) and APTIMA®Bacterial Vaginosis (BV from now on). Additionally, we assess the acceptability of tampons as a self-collection tool.

METHODS

A cohort of 75 female participants aged 18-54 years was recruited through female-focused social networks. Participants provided informed consent and underwent both Health Care Workers (HCW-collected) and self-collected sample collection using the Daye Diagnostic Tampon. Samples were stored in ThinPrep Vials (TP Vial) or Aptima® Multitest Swab Collection Kit (APTIMA®) solutions. HPV and STI testing were performed using TMA-based assay on the fully automated Panther® Platform. Acceptability was assessed through a questionnaire with Likert-scale responses.

RESULTS

The study involved 60 participants who completed the study (80% of recruited participants). The self-collected tampons showed sensitivity and specificity of 66.67% and 90.74% (when rinsed in TP Vial) and 83.33% and 85.42% (when rinsed in APTIMA®) for HPV detection, respectively. For bacterial vaginosis (BV) detection, the tampons exhibited sensitivity and specificity of 100.0% and 96.43% (TP Vial) and 88.89% and 98.04% (APTIMA), respectively. For detection of chlamydia and gonorrhoea (AC2), the sensitivity and specificity were 100.00% and 100.0% (TP Vial) and 100.00% and 98.31% (APTIMA), respectively. Participants expressed a preference for tampon self-collection over HCW-collected swabs (90%).

CONCLUSION

Self-collected tampons demonstrated promising diagnostic accuracy to HCW-collected swabs for HPV and STI detection. The tampon self-collection method was well-accepted and preferred by participants, suggesting its potential as an alternative screening tool, particularly in low-resource settings. Further research with larger and more diverse populations is recommended to validate these findings and inform tampon-based self-collection programs for cervical cancer screening. Randomised controlled trials and comparisons with gold standard methods would enhance validation.

Comprehensive assessment of vaginal infections using a single swab

BACKGROUND

The decision to use a particular test to diagnose patients presenting with symptoms of vaginitis and/or STI is based primarily on the prevailing standards of care in the clinic at which the patient evaluation takes place. As a result, laboratory testing of vaginal samples for these patients often involves either an STI or a vaginitis test, but rarely both options simultaneously, which complicates the diagnosis and management of concurrent infections.

METHODS

Using de-identified remnant vaginal specimens from symptomatic patients previously tested for STI (Chlamydia trachomatis (CT), Neisseria gonorrhoeae (GC) and Trichomonas vaginalis (TV)) with the Becton Dickinson (BD) CTGCTV2 assay for BD MAX System, positivity for bacterial vaginosis (BV) and Candida spp (associated with vulvovaginal candidiasis (VVC)) were evaluated using the molecular-based BD MAX Vaginal Panel.

FINDINGS

The rate of STI/BV co-infection was 79.4% (227/286) in this symptomatic population, while that of STI/VVC was 27.0% (77/285). Women diagnosed with any one of the three STIs tested had an OR 2.86 (95% CI, 1.99, 4.11; p<0.0001) for a concurrent BV infection and OR 0.96 (95% CI, 0.67, 1.37; p=0.8085) for infection with Candida species.

CONCLUSION

Our results suggest that women being tested for STI have a high prevalence of co-infection with BV and a lower, although appreciable, prevalence of co-infection with VVC. The detection of co-occurring vaginal infections can be facilitated by molecular testing using a single sample.

Vaginal metatranscriptome meta-analysis reveals functional BV subgroups and novel colonisation strategies

BACKGROUND

The application of '-omics' technologies to study bacterial vaginosis (BV) has uncovered vast differences in composition and scale between the vaginal microbiomes of healthy and BV patients. Compared to amplicon sequencing and shotgun metagenomic approaches focusing on a single or few species, investigating the transcriptome of the vaginal microbiome at a system-wide level can provide insight into the functions which are actively expressed and differential between states of health and disease.

RESULTS

We conducted a meta-analysis of vaginal metatranscriptomes from three studies, split into exploratory (n = 42) and validation (n = 297) datasets, accounting for the compositional nature of sequencing data and differences in scale between healthy and BV microbiomes. Conducting differential expression analyses on the exploratory dataset, we identified a multitude of strategies employed by microbes associated with states of health and BV to evade host cationic antimicrobial peptides (CAMPs); putative mechanisms used by BV-associated species to resist and counteract the low vaginal pH; and potential approaches to disrupt vaginal epithelial integrity so as to establish sites for adherence and biofilm formation. Moreover, we identified several distinct functional subgroups within the BV population, distinguished by genes involved in motility, chemotaxis, biofilm formation and co-factor biosynthesis. After defining molecular states of health and BV in the validation dataset using KEGG orthology terms rather than community state types, differential expression analysis confirmed earlier observations regarding CAMP resistance and compromising epithelial barrier integrity in healthy and BV microbiomes and also supported the existence of motile vs. non-motile subgroups in the BV population. These findings were independent of the enzyme classification system used (KEGG or EggNOG).

CONCLUSIONS

Our findings highlight a need to focus on functional rather than taxonomic differences when considering the role of microbiomes in disease and identify pathways for further research as potential BV treatment targets. Video Abstract.

Microbe-binding Antibodies in the Female Genital Tract: Associations with the Vaginal Microbiome and Genital Immunology

Bacteria-Ig interactions maintain homeostasis in the gut through the clearance of pathogenic bacteria and the development of immune tolerance to inflammatory bacteria; whether similar interactions modulate inflammation and bacterial colonization in the female genital tract is uncertain. In this study, we used a flow cytometry-based assay to quantify microbe-binding IgA and IgG in the cervicovaginal secretions of 200 HIV-uninfected women from Nairobi, Kenya that were enriched for bacterial vaginosis. Total IgA and IgG were abundant and frequently demonstrated ex vivo binding to the key vaginal bacteria species Gardnerella vaginalis, Prevotella bivia, Lactobacillus iners, and Lactobacillus crispatus, which are largely microbe-specific. Microbe-binding Abs were generally not associated with the presence or abundance of their corresponding bacteria. Total and microbe-binding IgA and IgG were inversely correlated with total bacterial abundance and positively correlated with several proinflammatory cytokines (IL-6, TNF) and chemotactic chemokines (IP-10, MIG, MIP-1α, MIP-1β, MIP-3α, MCP-1, IL-8), independent of total bacterial abundance. Flow cytometry-based quantification of microbe-binding Abs provides a platform to investigate host-microbiota interactions in the female genital tract of human observational and interventional studies. In contrast to the gut, cervicovaginal microbe-binding IgA and IgG do not appear to be immunoregulatory but may indirectly mitigate bacteria-induced inflammation by reducing total bacterial abundance.

Beta-carbolines suppress vaginal inflammation

Vaginal lactobacilli are key regulators of host inflammation, yet the mechanisms remain understudied. In this issue of Cell Host & Microbe, Glick et al. identify a family of beta-carbolines as anti-inflammatory effectors produced by vaginal Lactobacillus species, highlighting their potential as therapeutics for vaginal inflammatory disorders.

Vaginal Lactobacillus fatty acid response mechanisms reveal a metabolite-targeted strategy for bacterial vaginosis treatment

Bacterial vaginosis (BV), a common syndrome characterized by Lactobacillus-deficient vaginal microbiota, is associated with adverse health outcomes. BV often recurs after standard antibiotic therapy in part because antibiotics promote microbiota dominance by Lactobacillus iners instead of Lactobacillus crispatus, which has more beneficial health associations. Strategies to promote L. crispatus and inhibit L. iners are thus needed. We show that oleic acid (OA) and similar long-chain fatty acids simultaneously inhibit L. iners and enhance L. crispatus growth. These phenotypes require OA-inducible genes conserved in L. crispatus and related lactobacilli, including an oleate hydratase (ohyA) and putative fatty acid efflux pump (farE). FarE mediates OA resistance, while OhyA is robustly active in the vaginal microbiota and enhances bacterial fitness by biochemically sequestering OA in a derivative form only ohyA-harboring organisms can exploit. OA promotes L. crispatus dominance more effectively than antibiotics in an in vitro BV model, suggesting a metabolite-based treatment approach.

Vaginitis and risk of sexually transmitted infections: results of a multi-center U.S. clinical study using STI nucleic acid amplification testing

Significant increases in rates of sexually transmitted infections (STIs) caused by Trichomonas vaginalis (TV), Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Mycoplasma genitalium (MG) are occurring in the United States. We present results of a U.S. study examining the intersection of STIs and vaginitis. Among 1,051 women with diagnoses for the presence or absence of bacterial vaginosis (BV) and/or symptomatic vulvovaginal candidiasis (VVC), 195 (18.5%) had one or more STIs, including 101 (9.6%) with TV, 24 (2.3%) with CT, 9 (0.8%) with NG, and 93 (8.8%) with MG. STI prevalence in BV-positive women was 26.3% (136/518), significantly higher than STI prevalence of 12.5% (59/474) in BV-negative women (P < 0.0002). Unlike infections with CT or NG, solo infections of MG or TV were each significantly associated with a diagnosis of BV-positive/VVC-negative (OR 3.0751; 95% CI 1.5797-5.9858, P = 0.0113, and OR 2.873; 95% CI 1.5687-5.2619, P = 0.0017, respectively) and with mixed infections containing MG and TV (OR 3.4886; 95% CI 1.8901-6.439, P = 0.0042, and OR 3.1858; 95% CI 1.809-5.6103, P = 0.0014, respectively). TV and MG infection rates were higher in all Nugent score (NS) categories than CT and NG infection rates; however, both STIs had similar comparative prevalence ratios to CT in NS 6-10 vs NS 0-5 (CT: 3.06% vs 1.4%, 2.2-fold; MG: 10.7% vs 6.1%, 1.8-fold; TV: 14.5% vs 7.0%, 2.1-fold). NG prevalence was relatively invariant by the NS category. These results highlight the complexity of associations of STIs with two major causes of vaginitis and underscore the importance of STI testing in women seeking care for abnormal vaginal discharge and inflammation.

IMPORTANCE

This study reports high rates for sexually transmitted infections (STIs) in women seeking care for symptoms of vaginitis and bacterial vaginosis, revealing highly complex associations of STIs with two of the major causes of vaginal dysbiosis. These results underscore the importance of STI testing in women seeking care for abnormal vaginal discharge and inflammation.

Synergistic anti-virulence efficacy of citral and carvacrol against mixed vaginitis causing Candida albicans and Gardnerella vaginalis: An in vitro and in vivo study

Mixed vaginitis due to bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC) is the most prevalent form and presents a significant therapeutic challenge globally. Since, the administration of monotherapy leads to subsequent recurrent infections, synergistic therapy that completely eradicates both pathogens is of dire need to manage mixed vaginities scenario and to prevent its recurrence. The current investigation was focused on exploring the synergistic inhibitory efficacy of phytochemicals against the virulence traits of individual and mixed species of C. albicans and G. vaginalis in vitro and in vivo (Galleria mellonella). Out of five phytochemicals (carvacrol, thymol, cinnamaldehyde, eugenol, and borneol) screened for synergism with citral [(Ct) as the prime molecule owing to its myriad therapeutic potential], carvacrol (Ca) in combination with citral exhibited promising synergistic effect. Time-kill kinetics and one-minute contact-killing assays demonstrated the phenomenal microbicidal effect of Ct-Ca combination against both mono and dual-species within 30 min and one-minute time intervals, respectively. Furthermore, the sub-CMICs (synergistic combinatorial MIC) of Ct-Ca have significantly eradicated the mature biofilms and remarkably reduced the virulence attributes of both C. albicans and G. vaginalis (viz., yeast to hyphae transition, filamentation, protease production, and hydrophobicity index), in single and dual species states. The non-toxic nature of Ct-Ca combination was authenticated using in vitro (human erythrocyte cells) and in vivo (Galleria mellonella) models. In addition, the in vivo efficacy evaluation and subsequent histopathological investigation was done using the invertebrate model system G. mellonella, which further ascertained the effectiveness of Ct-Ca combination in fighting off the infection caused by individual and mixed species of C. albicans and G. vaginalis. Concomitantly, the current work is the first of its kind to delineate the in vitro interaction of C. albicans and G. vaginalis mixed species at their growth and biofilm states, together emphasizes the promising therapeutic potential of acclaimed phytochemicals as combinatorial synergistic therapy against mixed vaginitis.

Association between body mass index and prevalence of bacterial vaginosis: Results from the NHANES 2001-2004 study

BACKGROUND

The impact of bacterial vaginosis on women's health is an increasing concern; however, the effect of the obesity index on bacterial vaginosis is controversial. We investigated the association between body mass index and bacterial vaginosis in women in the United States.

METHODS

This was a cross-sectional study which obtained the data from the National Health and Nutrition Examination Survey from 2001 to 2004, in which weighted multivariate regression and logistic regression analyses were performed to explore the independent relationship between body mass index and bacterial vaginosis. Subgroup analyses and smoothed curve fitting were also performed.

RESULTS

A total of 5,428 participants were enrolled, and the findings show that the participants with higher body mass index tended to have a higher incidence of bacterial vaginosis. In the fully adjusted model, a positive association between bacterial vaginosis and body mass index was observed (Odd's ratio = 1.03, 95% Confidence interval, 1.01-1.04). The subgroup analysis showed that this positive association was significant in non-Hispanic White individuals (Odd's ratio = 1.0327, 95% Confidence interval, 1.0163, 1.0493).

CONCLUSION

Increased bacterial vaginosis positivity may be associated with an increased body mass index.

Untargeted metabolomics uncovers prime pathways linked to antibacterial action of citral against bacterial vaginosis-causing Gardnerella vaginalis: An in vitro and in vivo study

Global increase in recurrence of bacterial vaginosis (BV) and worrisome rise in antimicrobial resistance pose an urgent call for new/novel antibacterial agents. In light of the circumstance, the present study demonstrates the in vitro and in vivo antibacterial activity of a phytochemical citral, with a particular emphasis to elucidate its mechanistic action against Gardnerella vaginalis -a potential cause of BV. Out of 21 phytochemicals screened initially against G. vaginalis, citral was envisaged to be a phenomenal antibacterial agent showing MIC and MBC at 128 μg/mL. Citral's rapid killing ability was revealed by a time-killing kinetics assay supported by CFU, signifying that it completely killed the given inoculum of planktonic G. vaginalis cells within 60 min. Further, citral was found to exhibit 1 min contact-killing efficacy together with mature-biofilm disintegrating ability at increasing MICs. To further understand the molecular action of citral, in vitro investigations such as ROS estimation, PI staining and intracellular protein release assay were performed, which demonstrated that citral deteriorated the membrane integrity of G. vaginalis. Galleria mellonella, a simple invertebrate model used to evaluate citral's non-toxic and antibacterial activity in vivo, demonstrates that citral completely restored the larvae from G. vaginalis infection. The metabolite level investigation using LC-MS revealed that citral had negative impact on biotin metabolism (via., biotin), spermidine metabolism (via., 5'-methylthioadenosine and spermidine) and nucleotide metabolism (via., guanine, adenine and uridine). Since that biotin is associated with seven different metabolic pathways, it is conceivable that citral could target biotin biosynthesis or its metabolism and as a result, disrupt other metabolic pathways, such as lipid and fatty acid synthesis, which is essential for the creation of cell membranes. Thus, the current study is the first of its kind to delineate the promising in vitro and in vivo antibacterial efficacy of citral and decipher its plausible antibacterial action mechanism through metabolomic approach, which concomitantly emphasizes citral as a viable natural therapeutic alternative to manage and control BV.

Sub-communities of the vaginal microbiota in pregnant and non-pregnant women

Diverse and non-Lactobacillus-dominated vaginal microbial communities are associated with adverse health outcomes such as preterm birth and the acquisition of sexually transmitted infections. Despite the importance of recognizing and understanding the key risk-associated features of these communities, their heterogeneous structure and properties remain ill-defined. Clustering approaches are commonly used to characterize vaginal communities, but they lack sensitivity and robustness in resolving substructures and revealing transitions between potential sub-communities. Here, we address this need with an approach based on mixed membership topic models. Using longitudinal data from cohorts of pregnant and non-pregnant study participants, we show that topic models more accurately describe sample composition, longitudinal changes, and better predict the loss of Lactobacillus dominance. We identify several non-Lactobacillus-dominated sub-communities common to both cohorts and independent of reproductive status. In non-pregnant individuals, we find that the menstrual cycle modulates transitions between and within sub-communities, as well as the concentrations of half of the cytokines and 18% of metabolites. Overall, our analyses based on mixed membership models reveal substructures of vaginal ecosystems which may have important clinical and biological associations.

Sociodemographic and Behavioral Predictors of Recurrent Bacterial Vaginosis Among Sexual Health Clinic Patients in New York City From 2014 to 2018

OBJECTIVE

Bacterial vaginosis (BV) is associated with adverse reproductive outcomes, and recurrence is common. We examined factors associated with BV recurrence using electronic medical record data for patients attending New York City Department of Health and Mental Hygiene sexual health clinics from 2014 to 2018.

METHODS

Clinician-diagnosed BV was defined using a clinical BV diagnosis code based on Amsel criteria. Recurrent BV was defined as any BV diagnosis occurring more than 30 days after the previous diagnosis. Adjusted hazard ratios (AHRs) for the relationship between potential risk factors and recurrent BV were estimated using conditional gap-time models.

RESULTS

The data set contained 14,858 patients with at least one BV diagnosis. Of these, 46.3% (n = 6882) had at least 1 follow-up visit to a sexual health clinic between January 2014 and December 2018. Of those with a follow-up visit, 53.9% (n = 3707) had ≥1 recurrent BV episode, with 33.7% (n = 2317) experiencing recurrence within 3 months. In the multivariable model, using a hormonal intrauterine device (IUD; AHR, 1.31; 95% confidence interval [CI], 1.14-1.49) or copper IUD (AHR, 1.17; 95% CI, 1.01-1.37), having a history of trichomonas (AHR, 1.23; 95% CI, 1.12-1.36), and being non-Hispanic Black (AHR, 1.11; 95% CI, 1.04-1.18) were associated with a higher risk of BV recurrence, whereas using non-IUD hormonal contraception was associated with reduced risk (AHR, 0.88; 95% CI, 0.80-0.98).

CONCLUSIONS

Risk of BV recurrence was increased among patients using an IUD, whereas it was reduced in patients using non-IUD hormonal contraception.

Vaginal Microbial Network Analysis Reveals Novel Taxa Relationships among Adolescent and Young Women with Incident Sexually Transmitted Infection Compared with Those Remaining Persistently Negative over a 30-Month Period

A non-optimal vaginal microbiome (VMB) is typically diverse with a paucity of Lactobacillus crispatus and is often associated with bacterial vaginosis (BV) and sexually transmitted infections (STIs). Although compositional characterization of the VMB is well-characterized, especially for BV, knowledge remains limited on how different groups of bacteria relate to incident STIs, especially among adolescents. In this study, we compared the VMB (measured via 16S ribosomal RNA gene amplicon sequencing) of Kenyan secondary school girls with incident STIs (composite of chlamydia, gonorrhea, and trichomoniasis) to those who remained persistently negative for STIs and BV over 30 months of follow-up. We applied microbial network analysis to identify key taxa (i.e., those with the greatest connectedness in terms of linkages to other taxa), as measured by betweenness and eigenvector centralities, and sub-groups of clustered taxa. VMB networks of those who remained persistently negative reflected greater connectedness compared to the VMB from participants with STI. Taxa with the highest centralities were not correlated with relative abundance and differed between those with and without STI. Subject-level analyses indicated that sociodemographic (e.g., age and socioeconomic status) and behavioral (e.g., sexual activity) factors contribute to microbial network structure and may be of relevance when designing interventions to improve VMB health.

Vaginal microbiome in obesity and its impact on reproduction

A number of reproductive outcomes have been increasingly found to be affected by the vaginal microbiota. Obesity has become a global epidemic, affecting increasing numbers of reproductive-age women, and has been shown to be a risk factor for a number of adverse female health outcomes. A healthy vaginal microbiome is characterized by Lactobacillus-dominance, in particular Lactobacillus crispatus; obesity has been found to be associated with higher diversity and a lower likelihood of Lactobacillus-dominance. In this review, we summarize the evidence on the vaginal microbiome in obese women and the impact on reproductive outcomes such as conception rates, early pregnancy, and preterm birth. We further explore the mechanisms by which obesity may result in an altered microbial composition and highlight future avenues for therapeutic targeting of the vaginal microbiota.

Vaginal epithelial dysfunction is mediated by the microbiome, metabolome, and mTOR signaling

Bacterial vaginosis (BV) is characterized by depletion of Lactobacillus and overgrowth of anaerobic and facultative bacteria, leading to increased mucosal inflammation, epithelial disruption, and poor reproductive health outcomes. However, the molecular mediators contributing to vaginal epithelial dysfunction are poorly understood. Here we utilize proteomic, transcriptomic, and metabolomic analyses to characterize biological features underlying BV in 405 African women and explore functional mechanisms in vitro. We identify five major vaginal microbiome groups: L. crispatus (21%), L. iners (18%), Lactobacillus (9%), Gardnerella (30%), and polymicrobial (22%). Using multi-omics we show that BV-associated epithelial disruption and mucosal inflammation link to the mammalian target of rapamycin (mTOR) pathway and associate with Gardnerella, M. mulieris, and specific metabolites including imidazole propionate. Experiments in vitro confirm that type strain G. vaginalis and M. mulieris supernatants and imidazole propionate directly affect epithelial barrier function and activation of mTOR pathways. These results find that the microbiome-mTOR axis is a central feature of epithelial dysfunction in BV.

Optimizing the vaginal microbiome as a potential strategy to reduce heterosexual HIV transmission

Bacterial vaginosis (BV) is a proinflammatory genital condition characterized by high vaginal bacterial diversity and a paucity of Lactobacillus species. BV has been linked to an elevated risk of HIV acquisition among HIV-negative women and of forward HIV transmission to male sex partners among women living with HIV (adjusted hazard ratios of 1.69 and 3.17, respectively), potentially by eliciting genital inflammation in women with BV and their male sex partners. BV is also highly prevalent among women in sub-Saharan Africa, suggesting that BV treatment may have potential as an HIV prevention strategy. BV is typically treated with antibiotics but recurrence rates are high, possibly because treatment does not directly promote Lactobacillus growth. More recently, BV treatment strategies incorporating live biotherapeutic lactobacilli have led to sustained optimization of the vaginal microbiome and a decrease in inflammatory biomarkers previously associated with HIV susceptibility. Future studies are urgently needed to evaluate BV treatment strategies that can optimize the vaginal microbiome in the long term through colonization with H₂ O₂ -producing vaginal lactobacilli and to assess whether vaginal microbiota optimization is able to reduce the risk of HIV transmission.

Distinct cervical tissue-adherent and luminal microbiome communities correlate with mucosal host gene expression and protein levels in Kenyan sex workers

BACKGROUND

The majority of studies characterizing female genital tract microbiota have focused on luminal organisms, while the presence and impact of tissue-adherent ectocervical microbiota remain incompletely understood. Studies of luminal and tissue-associated bacteria in the gastrointestinal tract suggest that these communities may have distinct roles in health and disease. Here, we performed a multi-omics characterization of paired luminal and tissue samples collected from a cohort of Kenyan female sex workers.

RESULTS

We identified a tissue-adherent bacterial microbiome, with a higher alpha diversity than the luminal microbiome, in which dominant genera overall included Gardnerella and Lactobacillus, followed by Prevotella, Atopobium, and Sneathia. About half of the L. iners-dominated luminal samples had a corresponding Gardnerella-dominated tissue microbiome. Broadly, the tissue-adherent microbiome was associated with fewer differentially expressed host genes than the luminal microbiome. Gene set enrichment analysis revealed that L. crispatus-dominated tissue-adherent communities were associated with protein translation and antimicrobial activity, whereas a highly diverse microbial community was associated with epithelial remodeling and pro-inflammatory pathways. Tissue-adherent communities dominated by L. iners and Gardnerella were associated with lower host transcriptional activity. Tissue-adherent microbiomes dominated by Lactobacillus and Gardnerella correlated with host protein profiles associated with epithelial barrier stability, although with a more pro-inflammatory profile for the Gardnerella-dominated microbiome group. Tissue samples with a highly diverse composition had a protein profile representing cell proliferation and pro-inflammatory activity.

CONCLUSION

We identified ectocervical tissue-adherent bacterial communities in all study participants of a female sex worker cohort. These communities were distinct from cervicovaginal luminal microbiota in a significant proportion of individuals. We further revealed that bacterial communities at both sites correlated with distinct host gene expression and protein levels. The tissue-adherent bacterial community could possibly act as a reservoir that seed the lumen with less optimal, non-Lactobacillus, bacteria. Video Abstract.

Impact of (recurrent) bacterial vaginosis on quality of life and the need for accessible alternative treatments

BACKGROUND

Bacterial vaginosis (BV) is one of the most common vaginal dysbiosis in women aged 15-44 years old.

METHODS

We administered a cross-sectional, single timepoint survey to women ages 18 years or older and who have had bacterial vaginosis (BV). Women completed an anonymous online survey evaluating the impact of BV on their quality of life, how effective different types of treatments were and the amount of self-diagnosed vs. provider diagnosed BV episodes they had.

RESULTS

62 participants completed the anonymous online survey. With a self-reported median number of BV episodes in the past year was 4 (IQR 1-7). Among these women 69.8% reported BV had a negative impact on their sexual health, 67.7% on their physical health, 74.6% on their mental health. More than half of the respondents had used probiotics with oral Lactobacillus sp. (53.2%), mainly by oral route, and over a third had used vaginal boric acid (37.1%). Most women were unaware of Lactobacillus crispatus. Lactobacillus probiotics were more likely to be tried by women who were negatively impacted by BV for overall quality of life (p = 0.033), sexual health (p = 0.002), and mental health (p = 0.006) while boric acid use was more likely to be used by women who were negatively impacted by BV for their sexual health (p = 0.008).

CONCLUSIONS

BV is associated with negative quality of life and the women most impacted are seeking alternative treatments such as probiotics (Lactobacillus) and boric acid. There needs to be improvements in BV treatment that include alternative therapy options that have demonstrated efficacy with standardized composition, formulation and dosage.

Gardnerella subgroup dominant microbiomes are associated with divergent cervicovaginal immune responses in a longitudinal cohort of Kenyan women

Most cervicovaginal microbiome-immunology studies to date have relied on 16S rDNA microbial profiling which does not resolve the molecular subgroups of Gardnerella, believed to be central to the pathogenesis of bacterial vaginosis (BV) and subsequent risk of HIV acquisition. Here we used the cpn60 universal target which in addition to other microbial taxa, resolves four Gardnerella subgroups, for cervicovaginal microbial profiling in a longitudinal cohort of Kenyan women to examine associations with cellular and soluble markers of inflammation and HIV susceptibility. Participants (N = 41) were sampled, contributing 362 samples for microbiome analysis. All non-Lactobacillus dominant microbial communities were associated with high pro-inflammatory cytokine levels. Divergent associations were observed among different Gardnerella subgroup dominated communities with respect to the chemokine IP-10. Specifically, Gardnerella subgroup A dominant and polymicrobial communities were associated with reduced concentrations of IP-10 in adjusted linear mixed models (p<0.0001), compared to microbial communities dominated by Lactobacillus (non-iners) species. However, these associations did not translate to significant differences in the proportion or absolute number of CCR5, HLA-DR and CD38 expressed on cervical CD4⁺ T- cells. These findings suggest that some associations between Gardnerella subgroup dominant microbiomes and mucosal immunity differ and are relevant for the study of BV-pathogenesis and understanding the mechanisms of BV-associated HIV risk.

The Continuum of Microbial Ecosystems along the Female Reproductive Tract: Implications for Health and Fertility

The microbial ecosystem of the female urogenital tract is composed of many niche microenvironments across multiple organ systems in the urinary and reproductive tract. It is complex and contains a variety of bacteria, archaea, viruses, yeast, and protozoa-Many of which are still unidentified or whose functionality is unknown. Unlike the gut microbiome, whose composition is relatively stable in the absence of external perturbations, the urogenital microbiome is constantly shifting in response to biological cycles such as hormonal fluctuations during menstruation. Microbial composition differs between women but the dominance of some microbial families, such as Lactobacillaceae and other lactic acid-producing bacteria, are shared. Research suggests that it is difficult to define a universal healthy urogenital microbiome and consequently map a path to recovery from disease due to dysbiosis. Due to its temporal shifts, the female urogenital microbiome offers a unique opportunity to examine the biological mechanisms that work to restore a microbiome to its baseline. Common functional disorders in women's health are often difficult to diagnose and treat, are prone to recurrence, and can lead to subfertility or infertility. Knowledge of the interconnected microorganism communities along the continuum of the female reproductive tract could revolutionize the quality of women's healthcare.

Altered Innate Immunity and Damaged Epithelial Integrity in Vaginal Microbial Dysbiosis

The role of neutrophils relative to vaginal dysbiosis is unclear. We hypothesize that bacterial vaginosis (BV)-associated bacteria may induce the activation and accumulation of mucosal neutrophils within the female reproductive tract (FRT), resulting in epithelial barrier damage. We collected endocervical cytobrushes from women with and without BV and assessed bacteria community type and frequency/functional phenotypes of neutrophils. We performed in vitro whole blood co-cultures with BV-associated bacteria and healthy vaginal commensals and assessed their impact on epithelial integrity using transepithelial electrical resistance. We demonstrated increased neutrophil frequency (p < 0.0001), activation (p < 0.0001), and prolonged lifespan (p < 0.0001) in the cytobrushes from women with non-Lactobacillus dominant (nLD) communities. Our in vitro co-cultures confirmed these results and identified significant barrier damage in the presence of neutrophils and G. vaginalis. Here, we demonstrate that BV-associated bacteria induce neutrophil activation and increase lifespan, potentially causing accumulation in the FRT and epithelial barrier damage.

Host and Microbiome Interplay Shapes the Vaginal Microenvironment

The female reproductive tract harbors a unique microbiome, especially the vagina. The human vaginal microbiome exhibits a low diversity and is dominated by Lactobacillus species, compared to the microbiome of other organs. The host and vaginal microbiome mutually coexist in the vaginal microenvironment. Host cells provide Lactobacillus glycogen as an energy source, and Lactobacillus produce lactic acid, which lowers vaginal pH thereby preventing growth of other bacteria. Bacterial vaginosis can modulate host immune systems, and is frequently associated with various aspects of disease, including sexually transmitted infection, gynecologic cancer, and poor pregnancy outcomes. Because of this, numerous studies focused on the impact of the vaginal microbiome on women`s health and disease. Furthermore, numerous epidemiologic studies also have demonstrated various host factors regulate the vaginal microbiome. The female reproductive tract undergoes constant fluctuations due to hormonal cycle, pregnancy, and other extrinsic factors. Depending on these fluctuations, the vaginal microbiome composition can shift temporally and dynamically. In this review, we highlight the current knowledge of how host factors modulate vaginal microbiome composition and how the vaginal microbiome contributes to maintaining homeostasis or inducing pathogenesis. A better understanding of relationship between host and vaginal microbiome could identify novel targets for diagnosis, prognosis, or treatment of microbiome-related diseases.

Correlates of bacterial vaginosis among women from North India

Background: Bacterial vaginosis (BV) is the most prevalent cause of abnormal vaginal discharge among pre-menopausal women and associated with adversities of sexual and reproductive health. The present study aimed to identify potential epidemiological and behavioural risk factors and clinical predictors of BV among women in Delhi, India. Methods: A cross-sectional study was conducted to assess 283 non-pregnant women aged 18-45 years for BV using Nugent's scoring criteria. Information on demographics, sexual behaviours, hygiene practices and clinical symptoms was obtained and evaluated for their association with Nugent-BV status. Results: A positive diagnosis for Nugent-BV was made in 69 (24.4%) participants, 55 (19.4%) were intermediate and 159 (65.2%) were negative for Nugent-BV. Infertility (p = .02) and recent unprotected sexual exposure (p = .02) were strongly associated with Nugent-BV. On the other hand, women who reported regular use of condoms during intercourse were more likely to test negative (p = .03). None of the patient complaints, however, had any significant correlation with Nugent-BV diagnosis. Conclusion: Women in their reproductive years share the highest burden of adversities associated with bacterial vaginosis. History of infertility, recent unprotected sexual exposure and frequent use of condoms were correlates having significant associations with Nugent-BV.

Astodrimer sodium and bacterial vaginosis: a mini review

Bacterial vaginosis (BV) is the most common vaginal infection affecting women of childbearing age, and is associated with a substantial burden on women’s physical, emotional, sexual and social lives, as well as being linked to a number of gynaecological and obstetrical complications and adverse pregnancy outcomes. Antibiotics, such as metronidazole or clindamycin, are recommended as first-line treatment for BV, but may be associated with antibiotic resistance, high rates of recurrence and poor patient treatment satisfaction. Astodrimer sodium gel is a novel, non-antibiotic treatment for BV that is not systemically absorbed. It prevents pathogenic bacteria from adhering to the vaginal wall, and disrupts and inhibits the formation of pathogenic bacterial biofilms. Clinical cure rates of 50–57% were observed in patients with BV treated with astodrimer sodium compared with 17–21% treated with placebo (p < 0.001) in Phase 3 trials. In a separate Phase 3 trial, recurrence of BV occurred in 44% of patients treated with astodrimer sodium compared with 54% of patients who received placebo (p = 0.015). Astodrimer sodium is well tolerated, with vulvovaginal candidosis being the only treatment-related adverse event reported to occur more often than with placebo. The availability of astodrimer sodium, a well-tolerated, convenient, non-antibiotic treatment for BV, represents significant progress in the treatment of this burdensome condition.

Prevalence of bacterial vaginosis in postmenopausal women: a systematic review and meta-analysis

Bacterial vaginosis (BV), the most common cause of vaginal discharge in women of reproductive age, is associated with considerable reproductive and gynaecological sequelae and increases the risk of acquiring sexually transmissible infections including HIV. Although we understand the burden of BV in women of reproductive age, much less is known about the burden of BV in postmenopausal women. We undertook this systematic review and meta-analysis to estimate the prevalence of BV in postmenopausal women. The electronic databases PubMed, EMBASE, Web of Science, and The Cochrane Library were searched for English-language papers reporting on the prevalence of BV in postmenopausal women and published up until the end of July 2020. Search terms included: (prevalence OR survey OR proportion) AND 'bacterial vaginosis'. Meta-analysis was used to calculate pooled estimates of prevalence. We identified 2461 unique references and assessed 328 full-text articles for eligibility, with 13 studies included in the meta-analysis. The prevalence of BV ranged from 2.0 to 57.1%, with a summary estimate of 16.93% (95% CI: 8.5-27.4; I 2 =97.9). There was considerable heterogeneity between studies and quality varied considerably. Further research is needed to provide a better understanding of the condition in postmenopausal women and understand its effect on their lives.

Immunometabolic Analysis of Mobiluncus mulieris and Eggerthella sp. Reveals Novel Insights Into Their Pathogenic Contributions to the Hallmarks of Bacterial Vaginosis

The cervicovaginal microbiome plays an important role in protecting women from dysbiosis and infection caused by pathogenic microorganisms. In healthy reproductive-age women the cervicovaginal microbiome is predominantly colonized by protective Lactobacillus spp. The loss of these protective bacteria leads to colonization of the cervicovaginal microenvironment by pathogenic microorganisms resulting in dysbiosis and bacterial vaginosis (BV). Mobiluncus mulieris and Eggerthella sp. are two of the many anaerobes that can contribute to BV, a condition associated with multiple adverse obstetric and gynecological outcomes. M. mulieris has been linked to high Nugent scores (relating to BV morphotypes) and preterm birth (PTB), whilst some bacterial members of the Eggerthellaceae family are highly prevalent in BV, and identified in ~85-95% of cases. The functional impact of M. mulieris and Eggerthella sp. in BV is still poorly understood. To determine the individual immunometabolic contributions of Eggerthella sp. and M. mulieris within the cervicovaginal microenvironment, we utilized our well-characterized human three-dimensional (3-D) cervical epithelial cell model in combination with multiplex immunoassays and global untargeted metabolomics approaches to identify key immune mediators and metabolites related to M. mulieris and Eggerthella sp. infections. We found that infection with M. mulieris significantly elevated multiple proinflammatory markers (IL-6, IL-8, TNF-α and MCP-1) and altered metabolites related to energy metabolism (nicotinamide and succinate) and oxidative stress (cysteinylglycine, cysteinylglycine disulfide and 2-hydroxygluatrate). Eggerthella sp. infection significantly elevated multiple sphingolipids and glycerolipids related to epithelial barrier function, and biogenic amines (putrescine and cadaverine) associated with elevated vaginal pH, vaginal amine odor and vaginal discharge. Our study elucidated that M. mulieris elevated multiple proinflammatory markers relating to PTB and STI acquisition, as well as altered energy metabolism and oxidative stress, whilst Eggerthella sp. upregulated multiple biogenic amines associated with the clinical diagnostic criteria of BV. Future studies are needed to evaluate how these bacteria interact with other BV-associated bacteria within the cervicovaginal microenvironment.

The vaginal microbiome in women of reproductive age with healthy weight versus overweight/obesity

OBJECTIVE

The aim of this study was to evaluate the differences between the vaginal microbiome of reproductive-aged women with overweight and obesity (Ow/Ob) compared with healthy weight (HW).

METHODS

In this case-control study, a cohort of 367 nonpregnant women (18 to 40 years) with Ow/Ob (BMI ≥25 kg/m² ) was case-matched with 367 women with HW (BMI 18.0 to 24.9 kg/m² ). The study was a secondary analysis of 16S rRNA vaginal microbiome surveys through the Vaginal Human Microbiome Study (VaHMP). Groups were matched on age, race/ethnicity, income, and nulliparity status.

RESULTS

Mean age and BMI of Ow/Ob and HW groups were 26.8 versus 26.7 years and 37.0 versus 22.1 kg/m² , respectively. The overall vaginal microbiome composition differed between groups (PERMANOVA, p = 0.035). Women with Ow/Ob had higher alpha diversity compared with women with HW (Wilcoxon test, Shannon index p = 0.025; inverse Simpson index p = 0.026). Lactobacillus dominance (≥30% proportional abundance) was observed in a greater proportion of women with HW (48.7%) compared with Ow/Ob (40.1%; p = 0.026).

CONCLUSIONS

The vaginal microbiome differs in reproductive-aged women with Ow/Ob compared with women with HW, with increased alpha diversity and decreased predominance of Lactobacillus. Observed differences in the vaginal microbiome may partially explain differences in preterm birth and bacterial vaginosis risk between these populations.

Association of bacterial vaginosis with the most common sexually transmitted infections

Introduction/Objective. Bacterial vaginosis (BV) is the most common vaginal dysbiosis that enlarge a possibility of getting sexually transmitted infections (STI). The aims of this research is to examine association between BV and the nine most common causes of STIs (Chlamydia trachomatis, Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma spp, Trichomonas vaginalis, Neisseria gonorrhoeae, high-risk Human papilloma viruses and Herpes simplex virus type 1 and 2) and to determine if the presence of BV increase the probability of coinfection with any of the STIs microorganisms. Methods. This study involved 235 patients of reproductive age. One sample swab was collected each for vaginal and cervical testing. The vaginal swabs were used for detection of BV by RT-PCR test. The cervical swabs were used for the detection of the most common STIs which were tested by four different multiplex RT-PCR tests. Pearson?s ?2 test and Fisher?s probability test were used for statistical analysis of the results. Results. Comparison of the total number of STIs and the condition of the vaginal flora has shown that STIs are the most common in patients with BV 80 (89.9%). Women with BV have a higher frequency of infections with Ureaplasma spp. and M. Hominis, 71 (78.9%) and 50 (44.4%), respectively. The presence of detected STI pathogens and relation with the state of vaginal flora indicate that mono infections are present most often in patients with normal flora 51 (42.1%), while coinfections are mostly present in BV patients 50 (55.6%). Conclusion. This study has confirmed the association of M. hominis and Ureaplasma spp with BV as well as an association of coinfections with this dysbiosis. Better understanding of the association between various STIs and the status of vaginal flora is necessary to enable better diagnosis, prevention of diseases and women?s health protection.

Diagnostic concordance between Amsel's criteria and the Nugent scoring method in the assessment of bacterial vaginosis

Bacterial vaginosis (BV) is diagnosed by the microbiological Nugent scoring method or clinical Amsel's criteria. Assessment of 404 vaginal samples (293 women) identified 110 (27.2%), 108 (26.7%) and 161 (39.9%) samples to be BV-positive using Nugent's method, standard Amsel's criteria and simplified Amsel's criteria respectively. The sensitivity, specificity, and kappa statistic (κ) for standard and simplified Amsel's criteria were 71.8% (95% CI=62.4-80.0), 90.1% (95% CI=62.4-86.1), 0.62 (95% CI=0.53-0.72) and 88.2% (95% CI=80.6-93.6), 78.2% (95% CI=73.1-82.8), 0.58 (95% CI=0.49-0.67), respectively. A combination of vaginal pH and clue cells exhibited the highest concordance (κ=0.64, 95% CI=0.54-0.74) with Nugent's method and may be used for simplified BV diagnosis.

Bacterial Vaginosis and Its Association With Incident Trichomonas vaginalis Infections: A Systematic Review and Meta-Analysis

BACKGROUND

Bacterial vaginosis (BV) has been associated with an increased risk for acquisition of human immunodeficiency virus and sexually transmitted infections. We evaluated the association between BV and incident Trichomonas vaginalis (TV) infection in women.

METHODS

MEDLINE and ClinicalTrials.gov were searched for articles published between January 1, 1980, and May 7, 2021. Observational studies in women that evaluated the relationship between having/not having BV and the risk for acquiring TV were included.

RESULTS

Fourteen studies were included in the systematic review; 12 studies were included in meta-analyses involving 18,424 participants. Most studies used Nugent scoring to diagnose BV. For TV diagnosis, 12 studies used wet mount microscopy or culture, and 2 used nucleic acid amplification tests. There was diversity in the measures of association used, so an overall effect size could not be calculated. The majority of studies reported odds ratios, which showed an increased risk of incident TV among women with BV versus without BV (adjusted odds ratio, 1.87; 95% confidence interval, 1.45-2.40; P = 0.007). However, there were heterogeneity and potential confounding factors (eg, age, sexual partners) reported among studies.

CONCLUSIONS

This systematic review and meta-analysis provide evidence for a nearly 2-fold higher risk for acquiring TV among women with BV compared with women without BV.

Vaginal and Anal Microbiome during Chlamydia trachomatis Infections

Background.Chlamydia trachomatis (CT) is the agent of the most common bacterial sexually transmitted infection worldwide, with a significant impact on women's health. Despite the increasing number of studies about the vaginal microbiome in women with CT infections, information about the composition of the anal microbiome is still lacking. Here, we assessed the bacterial community profiles of vaginal and anal ecosystems associated or not with CT infection in a cohort of Caucasian young women. Methods. A total of 26 women, including 10 with a contemporary vaginal and ano-rectal CT infection, were enrolled. Composition of vaginal and anal microbiome was studied by 16S rRNA gene profiling. Co-occurrence networks of bacterial communities and metagenome metabolic functions were determined. Results. In case of CT infection, both vaginal and anal environments were characterized by a degree of dysbiosis. Indeed, the vaginal microbiome of CT-positive women were depleted in lactobacilli, with a significant increase in dysbiosis-associated bacteria (e.g., Sneathia, Parvimonas, Megasphaera), whereas the anal microbiota of CT-infected women was characterized by higher levels of Parvimonas and Pseudomonas and lower levels of Escherichia. Interestingly, the microbiome of anus and vagina had numerous bacterial taxa in common, reflecting a significant microbial 'sharing' between the two sites. In the vaginal environment, CT positively correlated with Ezakiella spp. while Gardnerella vaginalis co-occurred with several dysbiosis-related microbes, regardless of CT vaginal infection. The vaginal microbiome of CT-positive females exhibited a higher involvement of chorismate and aromatic amino acid biosynthesis, as well as an increase in mixed acid fermentation. Conclusions. These data could be useful to set up new diagnostic/prognostic tools, offering new perspectives for the control of chlamydial infections.

Modeling the temporal dynamics of cervicovaginal microbiota identifies targets that may promote reproductive health

BACKGROUND

Cervicovaginal bacterial communities composed of diverse anaerobes with low Lactobacillus abundance are associated with poor reproductive outcomes such as preterm birth, infertility, cervicitis, and risk of sexually transmitted infections (STIs), including human immunodeficiency virus (HIV). Women in sub-Saharan Africa have a higher prevalence of these high-risk bacterial communities when compared to Western populations. However, the transition of cervicovaginal communities between high- and low-risk community states over time is not well described in African populations.

RESULTS

We profiled the bacterial composition of 316 cervicovaginal swabs collected at 3-month intervals from 88 healthy young Black South African women with a median follow-up of 9 months per participant and developed a Markov-based model of transition dynamics that accurately predicted bacterial composition within a broader cross-sectional cohort. We found that Lactobacillus iners-dominant, but not Lactobacillus crispatus-dominant, communities have a high probability of transitioning to high-risk states. Simulating clinical interventions by manipulating the underlying transition probabilities, our model predicts that the population prevalence of low-risk microbial communities could most effectively be increased by manipulating the movement between L. iners- and L. crispatus-dominant communities.

CONCLUSIONS

The Markov model we present here indicates that L. iners-dominant communities have a high probability of transitioning to higher-risk states. We additionally identify transitions to target to increase the prevalence of L. crispatus-dominant communities. These findings may help guide future intervention strategies targeted at reducing bacteria-associated adverse reproductive outcomes among women living in sub-Saharan Africa. Video Abstract.

An updated review on the effects of depot medroxyprogesterone acetate on the mucosal biology of the female genital tract

Background

Access to safe, effective, and affordable contraception is important for women’s health and essential to mitigate maternal and fetal mortality rates. The progestin‐based contraceptive depot medroxyprogesterone acetate (DMPA) is a popular contraceptive choice with a low failure rate and convenient administration schedule.

Aim

In this review, we compiled observational data from human cohorts that examine how DMPA influences the mucosal biology of the female genital tract (FGT) that are essential in maintaining vaginal health, including resident immune cells, pro‐inflammatory cytokines, epithelial barrier function, and the vaginal microbiome

Materials and Methods

This review focused on the recent published literature published in 2019 and 2020.

Results

Recent longitudinal studies show that DMPA use associates with an immunosuppressive phenotype, increase in CD4+CCR5+ T cells, and alterations to growth factors. In agreement with previous meta‐analyses, DMPA use is associated with minimal effects of the composition of the vaginal microbiome. Cross‐sectional studies associate a more pro‐inflammatory relationship with DMPA, but these studies are confounded by inherent weaknesses of cross‐sectional studies, including differences in study group sizes, behaviors, and other variables that may affect genital inflammation.

Discussion & Conclusion

These recent results indicate that the interactions between DMPA and the vaginal mucosa are complex emphasizing the need for comprehensive longitudinal studies that take into consideration the measurement of multiple biological parameters.

The Female Vaginal Microbiome in Health and Bacterial Vaginosis

The vaginal microbiome is an intricate and dynamic microecosystem that constantly undergoes fluctuations during the female menstrual cycle and the woman's entire life. A healthy vaginal microbiome is dominated by Lactobacillus which produce various antimicrobial compounds. Bacterial vaginosis (BV) is characterized by the loss or sharp decline in the total number of Lactobacillus and a corresponding marked increase in the concentration of anaerobic microbes. BV is a highly prevalent disorder of the vaginal microbiota among women of reproductive age globally. BV is confirmed to be associated with adverse gynecologic and obstetric outcomes, such as sexually transmitted infections, pelvic inflammatory disease, and preterm birth. Gardnerella vaginalis is the most common microorganism identified from BV. It is the predominant microbe in polymicrobial biofilms that could shelter G. vaginalis and other BV-associated microbes from adverse host environments. Many efforts have been made to increase our understanding of the vaginal microbiome in health and BV. Thus, improved novel and accurate diagnosis and therapeutic strategies for BV have been developed. This review covers the features of vaginal microbiome, BV, BV-associated diseases, and various strategies of diagnosis and treatment of BV, with an emphasis on recent research progresses.

Current and emerging pharmacotherapy for recurrent bacterial vaginosis

INTRODUCTION

Given the frequency of recurrent bacterial vaginosis (RBV), enhancing treatment and preventing recurrence have become the central target of pharmacotherapy today. Antimicrobial failure is occurring at a time when knowledge of pathogenesis of bacterial vaginosis (BV) and RBV is incomplete, limiting rational treatment modification.

AREAS COVERED

The current manuscript reviews pathogenesis of RBV and the performance of available antimicrobials as well as attempts employed to enhance activity and pharmacologic strategies to reduce BV recurrence and refractory vaginal disease. The authors also provide their expert perspectives on the subject area, including their outlook for the future.

EXPERT OPINION

In the face of an empty pipeline of new antibiotics, strategies have emerged to enhance existing antibiotic efficacy, which include modifying drug dose, treatment duration, long-term prophylactic regimens, and use of biofilm disrupting agents. It is likely that future effective therapy will include several simultaneous and consecutive treatment components, including combinations of antibiotics, antibiofilm agents, and probiotics. Measures to prevent sexual transmission and reinfection are also essential.

Interleukin-36γ Is Elevated in Cervicovaginal Epithelial Cells in Women With Bacterial Vaginosis and In Vitro After Infection With Microbes Associated With Bacterial Vaginosis

In recent studies, the interleukin (IL)-36 cytokines were shown to be elevated in women with non-Lactobacillus-dominated vaginal microbiomes. In this study, we evaluated IL36G expression in clinical samples from women with and without bacterial vaginosis (BV) and a human 3-dimensional cervical epithelial cell model. IL36G expression was significantly elevated in cervicovaginal epithelial cells isolated from BV-positive women and corresponded with increased neutrophil counts relative to BV-negative women. In addition, specific BV-associated bacterial species as well as a polymicrobial cocktail significantly induced IL36G expression in vitro. These findings suggest that IL-36γ may exhibit an important function in the host response to BV and other sexually transmitted infections.

Comparative analysis of Bacterial Vaginosis microbiota among pregnant and non-pregnant females and isolation of phages against Enterococcus faecalis, Enterococcus faecium, and Shigella flexneri strains

BACKGROUND AND OBJECTIVES

Bacterial vaginosis (BV) is the most common vaginal infection in women of reproductive age. It shifts the paradigms of the vagina from healthy, beneficial microbiota to facultative and strict anaerobes. BV remains one of the most arduous and controversial challenges in modern-day clinical microbiology because of its high prevalence and relapse rates. A lot of research has been carried out on it. Still, its etiology is unknown, which gave this infection global importance. The current study was designed to investigate and compare the microbiota of pregnant and non-pregnant females suffering from BV, and phages were isolated against BV microbiota.

MATERIAL AND METHODS

The samples were collected from the vagina by using a speculum, and swabs were streaked on different media to isolate bacteria. The microbiological analysis was performed by microscopy, biochemical testing, and antibiotic susceptibility was determined by using Metronidazole and Clindamycin. Furthermore, the phages were isolated and characterized against BV strains.

RESULTS AND CONCLUSION

The Gram staining showed high prevalence of Staphylococcus (36% vs. 33%), followed by Streptococcus (31% vs. 14%) and Enterococcus (7% vs. 14%) in non-pregnant and pregnant females' respectively. However, the exception was observed in non-pregnant BV positive females, who had Shigella flexneri in their samples. The antibiotic sensitivity showed Metronidazole was resistant against all BV microbiota, and Clindamycin showed susceptibility against 3 strains. Phages were isolated against three bacterial strains, i.e. E. faecalis, E. faecium, and S. flexneri. Bacterial reduction assay showed bacterial growth decreases in the presence of phage suspension, pH stability showed phages' maximum lytic activity at pH 7 for E. faecalis and E. faecium and pH 9 for S. flexneri. However, the thermal stability showed phages' highest lytic activity at 55 °C for E. faecalis, 70 °C for E. faecium, and 40 °C for S. flexneri. Phage genome isolation showed that all phages nucleic acid was DNA in nature and between 15 and 20kbp. SEM analysis showed they were circular in shape and might belong to the Podoviridae family. This study provides an understanding of pathogens involved in BV and helps the doctors to treat the patients accordingly. Furthermore, this study showed that Bacterial Vaginosis and BV secondary bacteria have associations. BV secondary microbiota is also involved in the pathogenesis of this infection, whereas bacteriophage therapy has the potential to be used as an alternative treatment to antibiotics.

Gardnerella and vaginal health: the truth is out there

The human vagina is a dynamic ecosystem in which homeostasis depends on mutually beneficial interactions between the host and their microorganisms. However, the vaginal ecosystem can be thrown off balance by a wide variety of factors. Bacterial vaginosis (BV) is the most common vaginal infection in women of childbearing age but its etiology is not yet fully understood, with different controversial theories being raised over the years. What is generally accepted is that BV is often characterized by a shift in the composition of the normal vaginal microbiota, from a Lactobacillus species dominated microbiota to a mixture of anaerobic and facultative anaerobic bacteria. During BV, a polymicrobial biofilm develops in the vaginal microenvironment, being mainly composed of Gardnerella species. The interactions between vaginal microorganisms are thought to play a pivotal role in the shift from health to disease and might also increase the risk of sexually transmitted infections acquisition. Here, we review the current knowledge regarding the specific interactions that occur in the vaginal niche and discuss mechanisms by which these interactions might be mediated. Furthermore, we discuss the importance of novel strategies to fight chronic vaginal infections.

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.

Bacterial vaginosis and surgical site infections

Bacterial vaginosis is the most common cause of abnormal vaginal discharge or malodor, affecting up to one third of US women. Most women with bacterial vaginosis are unaware of the infection, making it difficult to diagnose in the absence of a microscopic examination of vaginal discharge or using point-of-care testing. Untreated bacterial vaginosis elevates the risk of postoperative surgical infections in women undergoing obstetric and gynecological procedures. Treatment with antimicrobial agents that target bacterial vaginosis has been shown to reduce the rate of postoperative infections following hysterectomy and surgical abortions. Furthermore, in a cost-comparison model, screening for and treatment of bacterial vaginosis prior to hysterectomy was shown to be superior to no screening in terms of infection rates and cost. The bacterial vaginosis diagnostic criteria are simple and screening tests are inexpensive; bacterial vaginosis screening is a relatively fast process in patients who present for preoperative appointments. Treatment options approved by the Food and Drug Administration include metronidazole, clindamycin, tinidazole, and secnidazole. Given the prevalence of bacterial vaginosis and the risks associated with operating on a woman with untreated bacterial vaginosis, women undergoing hysterectomy, surgical abortion, and potentially cesarean delivery should be screened for bacterial vaginosis, and those who screen positive should be treated with an appropriate antimicrobial agent.

Growth Forms of Gardnerella spp. and Lactobacillus spp. on Vaginal Cells

Bacterial vaginosis (BV) is a common vaginal condition in women of reproductive age. During BV development, BV-associated bacteria may form a polymicrobial biofilm, which predispose women to recurrent BV. The aim of the study was to investigate the growth forms of Gardnerella spp. and Lactobacillus spp. and to determine the association between the bacterial growth forms and clinical characteristics [urinary tract infection (UTI) symptoms, human immunodeficiency virus (HIV) infection and abnormal vaginal discharge] in women attending a tertiary hospital in Pretoria, South Africa. A first-void urine specimen was collected from 196 women and BV was diagnosed using the Nugent scoring and the Ison-Hay criteria (vaginal smear microscopy). Fluorescence in situ hybridisation (FISH) was performed to classify the growth forms [“dispersed” or “biofilm”]. Bacterial cells were categorized as “dispersed” if cells were scattered separately and as “biofilm” if bacterial aggregates on the vaginal epithelial cells were observed. BV was detected in 52 women (52/196; 27%) and in these women, Gardnerella spp. were predominantly present in biofilms (46/52; 88% for Nugent scoring; and 45/50; 90% for Ison-Hay criteria), whereas Lactobacillus spp. were predominantly present in a dispersed form (38/52; 73% for Nugent scoring; and 37/50; 74% for Ison-Hay criteria). The odds of having BV increased when Gardnerella biofilms were present (p < 0.001), whereas the opposite was observed for Lactobacillus biofilms (p = 0.001). Neither Gardnerella spp. or Lactobacillus spp. (both dispersed or biofilms) had an association with the presence of UTI symptoms, HIV coinfection or abnormal vaginal discharge. In conclusion, this study demonstrated and confirmed that Gardnerella biofilms are associated with BV and that Lactobacillus spp. may form biofilms to protect against BV.

Bacterial vaginosis-associated vaginal microbiota is an age-independent risk factor for Chlamydia trachomatis, Mycoplasma genitalium and Trichomonas vaginalis infections in low-risk women, St. Petersburg, Russia

The large majority of studies investigating associations between bacterial vaginosis (BV) and sexually transmitted infections (STIs) have been conducted among predominantly young women with high risk for STIs. Since a risky sexual behavior is a significant risk factor for both STIs and BV, this creates a bias toward an increased association between BV and STIs. This study evaluated associations between BV-associated vaginal microbiota and STIs (Chlamydia trachomatis, Mycoplasma genitalium, Trichomonas vaginalis, and Neisseria gonorrhoeae) in a population of women with low risk for STIs and investigated STI outcomes depending on the dominating Lactobacillus species. Repository cervicovaginal samples collected from reproductive-age women from January 2014 to February 2019 were characterized for vaginal microbiota types and the STIs using multiplex real-time PCR assays. In total, 95 STI-positive and 91 STI-negative samples were included. A significant, age-independent association between BV-associated vaginal microbiota and the presence of C. trachomatis, M. genitalium, and T. vaginalis infections was identified (age-adjusted odds ratios 2.92 [95% confidence interval (CI) 1.24–7.03], 2.88 [95% CI 1.19–7.16], and 9.75 × 10⁷ [95% CI 13.03-∞], respectively). Normal vaginal microbiota dominated by Lactobacillus crispatus, L. gasseri, or L. jensenii was a strong protective factor against C. trachomatis and/or M. genitalium infections, whereas L. iners-dominated microbiota was not significantly associated with C. trachomatis and/or M. genitalium positivity. The results of the present study confirm that STI prevention strategies should include interventions that also reduce the incidence of BV and promote a protective vaginal microbiota in both high- and low-risk women.

Reviewing the Composition of Vaginal Microbiota: Inclusion of Nutrition and Probiotic Factors in the Maintenance of Eubiosis

The vaginal microbiota has importance in preserving vaginal health and defending the host against disease. The advent of new molecular techniques and computer science has allowed researchers to discover microbial composition in depth and associate the structure of vaginal microbial communities. There is a consensus that vaginal flora is grouped into a restricted number of communities, although the structure of the community is constantly changing. Certain Community-Sate Types (CSTs) are more associated with poor reproductive outcomes and sexually transmitted diseases (STDs) meanwhile, CSTs dominated by Lactobacillus species-particularly Lactobacillus crispatus-are more related to vaginal health. In this work, we have reviewed how modifiable and non-modifiable factors may affect normal vaginal microbiota homeostasis-including sexual behavior, race or ethnicity, and hygiene. Special interest has been given to how the use of probiotics, diet intake, and use of hormone replacement therapies (HRTs) can potentially impact vaginal microbiota composition.

Bacterial vaginosis-A brief synopsis of the literature

Bacterial vaginosis (BV) affects women of reproductive age and can either be symptomatic or asymptomatic. Approximately 50 % of women are symptomatic and experience vaginal malodor, discharge, itching and increased vaginal pH. BV can increase the risk of contracting many sexually transmitted infections (STIs) such as human immunodeficiency virus (HIV), Neisseria gonorrhea (NG), Chlamydia trachomatis (CT), Trichomonas vaginalis (TV) and herpes simplex virus-2 (HSV-2). Though effective treatment options do exist, metronidazole or clindamycin, these methods have proven not to be effective long term. The purpose of this review is to summarize current literature on the epidemiology of BV and highlight areas of deficiency in current clinical practice with respect to BV. BV recurrence rates are high, approximately 80 % three months after effective treatment. Furthermore, in some instances treatment is ineffective and BV persists. Literature also documents the relationship between BV and human papillomavirus (HPV). HPV is the most common sexually transmitted infection among young adult women while BV is the most common cause of vaginal symptoms among women of reproductive age. BV is associated with high levels of anaerobic organisms which can damage the vaginal epithelium and increase the risk of HPV infection. Recent research also highlights the role of the vaginal microbiome in BV. The results of this review warrant further exploration into the etiology of BV as well as exploration of more long-term effective treatment and the investigation of prognostic indicators. Additionally, the need for a standard definition of recurrent and persistent BV is recognized.

Diversity of vaginal microbiome and metabolome during genital infections

We characterized the vaginal ecosystem during common infections of the female genital tract, as vulvovaginal candidiasis (VVC, n = 18) and Chlamydia trachomatis infection (CT, n = 20), recruiting healthy (HC, n = 21) and bacterial vaginosis-affected (BV, n = 20) women as references of eubiosis and dysbiosis. The profiles of the vaginal microbiome and metabolome were studied in 79 reproductive-aged women, by means of next generation sequencing and proton based-nuclear magnetic resonance spectroscopy. Lactobacillus genus was profoundly depleted in all the genital infections herein considered, and species-level analysis revealed that healthy vaginal microbiome was dominated by L. crispatus. In the shift from HC to CT, VVC, and BV, L. crispatus was progressively replaced by L. iners. CT infection and VVC, as well as BV condition, were mainly characterised by anaerobe genera, e.g. Gardnerella, Prevotella, Megasphaera, Roseburia and Atopobium. The changes in the bacterial communities occurring during the genital infections resulted in significant alterations in the vaginal metabolites composition, being the decrease of lactate a common marker of all the pathological conditions. In conclusion, according to the taxonomic and metabolomics analysis, we found that each of the four conditions is characterized by a peculiar vaginal microbiome/metabolome fingerprint.

Bacteriocin activity of Lactobacillus brevis and Lactobacillus paracasei ssp. paracasei

Methodology. Biochemical and molecular methods were used to identify 100 lactobacilli isolated from rectal swabs. Among these, L. paracasei ssp. paracasei LP5 and L. brevis LP9 showed significant antibacterial activity against S. agalactiae and L. monocytogenes. Accordingly, characterization of their bacteriocins, BacLP5 and BacLP9, was conducted to obtain information on their kinetic production, sensitivity to chemico-physical parameters and molecular weight. To investigate the possible use of the two Lactobacillus strains as probiotics, their gastrointestinal resistance, cellular adhesiveness and sensitivity to antibiotics were also studied.Results. The obtained data show that BacLP5 and BacLP9 most likely belong to class II bacteriocins and both have a molecular weight of approximately 3 kDa. The production of BacLP5 and BacLP9 started after 4 h (40 and 80 AU ml^-1), respectively. Both of the Lactobacillus strains survived gastric and intestinal juices well and showed adhesive capability on HEp-2 cells.Conclusion. Due to their peculiar antimicrobial characteristics, L. paracasei ssp. paracasei LP5 and L. brevis LP9 are suitable for use in the treatment of vaginal disorders, through both oral and transvaginal administration.

Quantitation of all Four Gardnerella vaginalis Clades Detects Abnormal Vaginal Microbiota Characteristic of Bacterial Vaginosis More Accurately than Putative G. vaginalis Sialidase A Gene Count

Background

Bacterial vaginosis (BV) is a vaginal disorder characterized by a depletion of the normal lactobacillus-dominant microbiota and overgrowth of mainly anaerobic bacteria.

Objectives

The study aimed to evaluate the distribution and abundance of the Gardnerella vaginalis clades and sialidase A gene in vaginal samples from Russian women, and investigate if the G. vaginalis sialidase A gene count detects an abnormal vaginal microbiota characteristic of BV more accurately than G. vaginalis load.

Methods

Vaginal samples from 299 non-pregnant patients of gynecological clinics were examined using Nugent scores and G. vaginalis clade and sialidase A gene quantitative real-time polymerase chain reactions (PCRs). Discriminatory power for BV microbiota was evaluated with receiver operating characteristic (ROC) analysis.

Results

The vaginal microbiota was characterized by Nugent scores as normal, intermediate, and BV microbiota in 162, 58, and 79 women, respectively. G. vaginalis clades 1, 2, 3, 4, and the sialidase A gene were detected in 56% (51–62%), 40% (34–45%), 20% (16–25%), 94% (91–96%), and 70% (64–75%) of vaginal samples, respectively. The frequency and abundance of clades 1, 2, 4, and the sialidase A gene as well as clade multiplicity were significantly associated with abnormal microbiota. The sialidase A gene was present in all multi-clade samples, in all single-clade samples comprising clades 1, 2, and 3, and in four of 84 (5% [2–12%]) samples comprising clade 4 only. Total G. vaginalis load showed significantly higher discriminatory power for abnormal microbiota than sialidase A gene count (areas under ROC curves 0.933 vs. 0.881; p = 0.0306).

Conclusions

Quantifying all four G. vaginalis clades discriminates between BV microbiota and normal microbiota more accurately than measuring G. vaginalis sialidase A gene. Clade 4 is strongly associated with BV microbiota, despite most clade 4 strains lacking the sialidase A gene.

Association between obesity and bacterial vaginosis as assessed by Nugent score

BACKGROUND

Bacterial vaginosis is 1 of the most common vaginal conditions in the United States. Recent studies have suggested that obese women have an abnormal microbiota reminiscent of bacterial vaginosis; however, few studies have investigated the prevalence of bacterial vaginosis in overweight and obese populations. Moreover, despite the increased prevalence of obesity and bacterial vaginosis in black women, it is not known whether racial disparities exist in the relationship between obesity and bacterial vaginosis.

OBJECTIVE

The objective of this study was to examine the relationship between body mass index and bacterial vaginosis as determined by Nugent score and to determine the influence of race in this context.

STUDY DESIGN

We performed a cross-sectional study using patient data and vaginal smears from 5918 participants of the Contraceptive CHOICE Project. Gram-stained vaginal smears were scored with the Nugent method and categorized as bacterial vaginosis-negative (Nugent score, 0-3), bacterial vaginosis-intermediate (Nugent score, 4-6), or bacterial vaginosis-positive (Nugent score, 7-10). Body mass index was determined with Centers for Disease Control and Prevention guidelines, and obese individuals were categorized as class I, II, or III obese based on National Institutes of Health and World Health Organization body mass index parameters. Linear regression was used to model mean differences in Nugent scores; Poisson regression with robust error variance was used to model prevalence of bacterial vaginosis.

RESULTS

In our cohort, 50.7% of participants were black; 41.5% were white, and 5.1% were of Hispanic ethnicity; the average age of 25.3 years old. Overall, 28.1% of participants were bacterial vaginosis-positive. Bacterial vaginosis was prevalent in 21.3% of lean, 30.4% of overweight, and 34.5% of obese women (P<.001). The distribution of bacterial vaginosis-intermediate individuals was similar across all body mass index categories. Compared with the scores of lean women, Nugent scores were highest among overweight and obese class I women (adjusted mean difference: overweight women, 0.33 [95% confidence interval, 0.14-0.51] and obese women, 0.51 [95% confidence interval, 0.29-0.72]). Consistent with this, overweight and obese women had a higher frequency of bacterial vaginosis compared with lean women, even after adjustment for variables that included race. Among white women, the prevalence of bacterial vaginosis was higher for overweight and class I and class II/III obese white women compared with lean white women, which is a phenomenon not observed among black women and suggests an effect modification.

CONCLUSION

Overweight and obese women have higher Nugent scores and a greater occurrence of bacterial vaginosis compared with lean women. Black women have a greater prevalence of bacterial vaginosis independent of their body mass index compared with white women.

Insights Into Vaginal Bacterial Communities and Metabolic Profiles of Chlamydia trachomatis Infection: Positioning Between Eubiosis and Dysbiosis

The vaginal microbiota plays a crucial role in maintaining the health and functioning of the female genital tract, preventing the colonization of urogenital pathogens and sexually transmitted infections. In this study, we characterized the vaginal bacterial communities and the metabolome associated to Chlamydia trachomatis infection (CT: 20 women), compared to healthy condition (H: 22 women) and bacterial vaginosis (BV: 19 women). A microarray-based tool (VaginArray), implemented with a real-time PCR for Gardnerella vaginalis, was used to determine the vaginal bacterial composition, whereas the metabolic profiles were assessed by a proton-based nuclear magnetic resonance (¹H-NMR) spectroscopy. CT infection was characterized by bacterial and metabolic signatures similar to healthy condition, even though higher amounts of Lactobacillus iners, as well as depletion of some amino acids, biogenic amines, and succinate marked CT infection. Moreover, the frequency of Lactobacillus crispatus was higher in asymptomatic CT-positive patients than in women with CT-correlated symptoms. We also confirmed the marked differences in the microbiome and metabolome between healthy and BV-affected women. In conclusion, we highlighted microbial and metabolic peculiarities of the vaginal ecosystem in the case of CT infection, even though further studies are needed to understand if the observed alterations precede the infection onset or if the pathogen itself perturbs the vaginal environment.