Vaginal lactobacillus flora of healthy Swedish women

Characterization of vaginal Lactobacillus in biologically relevant fluid using surface-enhanced Raman spectroscopy

The native vaginal microbiome plays a crucial role in maintaining vaginal health and disruption can have significant consequences for women during their lifetime. While the composition of the vaginal microbiome is important, current methods for monitoring this community are lacking. Clinically used techniques routinely rely on subjective analysis of vaginal fluid characteristics or time-consuming microorganism culturing. Surface-enhanced Raman spectroscopy (SERS) can aid in filling this gap in timely detection of alterations in the vaginal microbiome as it can discriminate between bacterial species in complex solutions including bacterial mixtures and biofluids. SERS has not previously been applied to study variations in vaginal Lactobacillus, the most common species found in the vaginal microbiome, in complex solutions. Herein, the SERS spectra of Lactobacillus crispatus (L. crispatus) and Lactobacillus iners (L. iners), two of the most common vaginal bacteria, was characterized at physiologically relevant concentrations. Subsequently, the ability of SERS to detect L. crispatus and L. iners in both pure mixtures and when mixed with a synthetic vaginal fluid mimicking solution was determined. In both pure and complex solutions, SERS coupled with partial least squares regression predicted the ratiometric bacterial content with less than 10% error and strong goodness of prediction (Q2 > 0.9). This developed method highlights the applicability of SERS to predict the dominant Lactobacillus in the vaginal micro-environment toward the monitoring of this community.

Bacteriocins: potentials and prospects in health and agrifood systems

Bacteriocins are highly diverse, abundant, and heterogeneous antimicrobial peptides that are ribosomally synthesized by bacteria and archaea. Since their discovery about a century ago, there has been a growing interest in bacteriocin research and applications. This is mainly due to their high antimicrobial properties, narrow or broad spectrum of activity, specificity, low cytotoxicity, and stability. Though initially used to improve food quality and safety, bacteriocins are now globally exploited for innovative applications in human, animal, and food systems as sustainable alternatives to antibiotics. Bacteriocins have the potential to beneficially modulate microbiota, providing viable microbiome-based solutions for the treatment, management, and non-invasive bio-diagnosis of infectious and non-infectious diseases. The use of bacteriocins holds great promise in the modulation of food microbiomes, antimicrobial food packaging, bio-sanitizers and antibiofilm, pre/post-harvest biocontrol, functional food, growth promotion, and sustainable aquaculture. This can undoubtedly improve food security, safety, and quality globally. This review highlights the current trends in bacteriocin research, especially the increasing research outputs and funding, which we believe may proportionate the soaring global interest in bacteriocins. The use of cutting-edge technologies, such as bioengineering, can further enhance the exploitation of bacteriocins for innovative applications in human, animal, and food systems.

Genital Dysbiosis and Different Systemic Immune Responses Based on the Trimester of Pregnancy in SARS-CoV-2 Infection

Respiratory infections are common in pregnancy with conflicting evidence supporting their association with neonatal congenital anomalies, especially during the first trimester. We profiled cytokine and chemokine systemic responses in 242 pregnant women and their newborns after SARS-CoV-2 infection, acquired in different trimesters. Also, we tested transplacental IgG passage and maternal vaginal-rectal microbiomes. IgG transplacental passage was evident, especially with infection acquired in the first trimester. G-CSF concentration-involved in immune cell recruitment-decreased in infected women compared to uninfected ones: a beneficial event for the reduction of inflammation but detrimental to ability to fight infections at birth. The later the infection was acquired, the higher the systemic concentration of IL-8, IP-10, and MCP-1, associated with COVID-19 disease severity. All infected women showed dysbiosis of vaginal and rectal microbiomes, compared to uninfected ones. Two newborns tested positive for SARS-CoV-2 within the first 48 h of life. Notably, their mothers had acute infection at delivery. Although respiratory infections in pregnancy are reported to affect babies' health, with SARS-CoV-2 acquired early during gestation this risk seems low because of the maternal immune response. The observed vaginal and rectal dysbiosis could be relevant for neonatal microbiome establishment, although in our series immediate neonatal outcomes were reassuring.

Vaginal microflora following the use of a disposable home-use vaginal device and a commercially available ring pessary for pelvic organ prolapse management: a randomized controlled trial

PURPOSE

To investigate whether ProVate, a novel, disposable, self-inserted vaginal device for pelvic organ prolapse management, clinically affects the vaginal microflora, as compared with a commercially available ring pessary, to assess its microbiological safety.

METHODS

This interventional, prospective, multi-center, open-label, randomized, controlled, statistically powered (noninferiority), home-use, crossover study was conducted at seven sites. Participants were randomized into either group A (using ProVate and then a new reusable commercially available ring pessary [control]) or B (using control device and then ProVate) with a 1:1 ratio. Noninferiority of ProVate over the control was evaluated for the primary endpoint, which was based on meeting one of the failure criteria: significant change in Lactobacillus spp., Gardnerella vaginalis, Candida morphotypes, or Staphylococcus aureus levels compared to the baseline (significant change: Nugent score ≥ 7 or > 1 scale unit increase in S. aureus or Candida morphotype), bothersome vaginal infection symptoms, or symptoms requiring treatment for infection.

RESULTS

The study included 58 participants (mean age: 64.5 years, 91.4% postmenopausal). There were no significant microfloral changes in terms of the four microorganisms mentioned above, the rate of Nugent score ≥ 7 after use was low and comparable between the two devices, and the rate of patients with a > 1 unit-scale change (increase or decrease) from the baseline to the end-of-use phase in any studied microorganism was comparable between the devices. The failure rate was 15.5% for ProVate and 15.5% for control while using 383 ProVate devices over 1647 days or one control device throughout the study. Two patients had bothersome vaginal complaints and one had overt vaginal infection in the control group, but no such cases were observed in the ProVate group.

CONCLUSION

The primary endpoint of possible vaginal microbial changes, bothersome vaginal symptoms, or treatment-requiring vaginal complaints while using ProVate was successfully met. Our findings show that the vaginal microflora is comparable when using either ProVate or commercially available ring pessary (control) with a relatively low rate of vaginal infections. Trial registration details: ClinicalTrials.gov; URL: https://www.

CLINICALTRIALS

gov/ct2/show/NCT03345121?term=NCT03345121&draw=2&rank=1 ; No. NCT03345121; Registration date, November 17, 2017; initial enrollment started on August 20, 2017.

Prophylactic application of vaginal lactic acid bacteria against urogenital pathogens and its prospective use in sanitary suppositories

Beneficial and pathogenic microbes coexist in the vaginal canal, where a diminishing population of lactic acid bacteria may cause recurring urogenital infections. Probiotic bacteria Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus vaginalis, and pathogenic microbes Enterococcus faecalis, Enterobacter cloacae, Shigella sp., Staphylococcus epidermidis, and Escherichia fergusonii were isolated from vaginal swabs. Lactobacillus sp. and their probiotic culture free supernatant (PCFS) inhibited the growth of the above-mentioned urogenital pathogens. L. crispatus produced both lactic acid and hydrogen peroxide, exhibiting the best antimicrobial potential against the studied pathogens. Lyophilized L. crispatus had a shelf life of 12 months and the lyophilized PCFS also retained its antibacterial property with a minimum inhibition concentration of 1 μg/μL. Carboxy-methyl cellulose-alginate, a green alternative to super-absorbent polymers, was encapsulated with L. crispatus cells. The probiotic in its encapsulated state retained its viability for 21 days, and the bead showed 30% solvent absorptive capacity. PCFS-laced non-woven fabric displayed antibacterial property with no change in its physicochemical properties. These probiotic and postbiotic formulations have excellent prophylactic potential for urogenital infections. Such formulations can be exploited as additives in sanitary suppositories to enhance vaginal health.

Infective Endocarditis by Lactobacillus Species-A Narrative Review

Bacteria of the genus Lactobacillus are microaerophilic or aerotolerant anaerobic Gram-positive non-spore-forming rods. They are considered essential members of the human gut microbiome; however, recent studies have revealed that these microorganisms are less predominant in the gut microbiome than initially thought. Lactobacillus spp. is mainly known for its use as a probiotic in foods and supplements to prevent and treat specific issues such as infectious diseases, irritable bowel syndrome, and diabetes mellitus. However, Lactobacillus spp. may occasionally cause infections such as bacteremia or infective endocarditis (IE). The present study aimed to review all cases of IE by Lactobacillus spp. and describe the epidemiology, microbiology, clinical characteristics, treatment, and outcomes of this infection by collecting relevant data from studies existing in Pubmed and Scopus until 28 September 2023. A total of 77 studies containing data for 82 patients were included. The median age was 56 years, and 69.6% were male. A prosthetic valve was present in 16% of patients, and 17.3% had previously been on probiotics. The aortic valve was the most commonly involved intracardiac site, followed by the mitral valve. Fever, embolic phenomena, sepsis, and heart failure were the most common clinical presentations. Aminoglycosides and penicillin were the most commonly used antimicrobials for definitive treatment. Surgery was performed in 53.7% of patients. Overall mortality was 17.1%. IE in prosthetic valves and presentation with shock were independently associated with overall mortality.

Vaginal microbial dynamics and pathogen colonization in a humanized microbiota mouse model

Vaginal microbial composition is associated with differential risk of urogenital infection. Although Lactobacillus spp. are thought to confer protection against infection, the lack of in vivo models resembling the human vaginal microbiota remains a prominent barrier to mechanistic discovery. Using 16S rRNA amplicon sequencing of C57BL/6J female mice, we found that vaginal microbial composition varies within and between colonies across three vivaria. Noting vaginal microbial plasticity in conventional mice, we assessed the vaginal microbiome of humanized microbiota mice (HMbmice). Like the community structure in conventional mice, HMbmice vaginal microbiota clustered into community state types but, uniquely, HMbmice communities were frequently dominated by Lactobacillus or Enterobacteriaceae. Compared to conventional mice, HMbmice were less susceptible to uterine ascension by urogenital pathobionts group B Streptococcus (GBS) and Prevotella bivia. Although Escherichia and Lactobacillus both correlated with the absence of uterine GBS, vaginal pre-inoculation with exogenous HMbmouse-derived E. coli, but not Ligilactobacillus murinus, reduced vaginal GBS burden. Overall, HMbmice serve as a useful model to elucidate the role of endogenous microbes in conferring protection against urogenital pathogens.

The analysis of Lactobacillus spp. distribution in the vaginal microbiota of Polish women with abnormal Pap smear result

Introduction

A healthy vaginal microbiota is represented mainly by Lactobacillus spp. and plays a vital role in maintaining the functional balance in the vaginal environment. Scientists have drawn attention to possible correlations between the vaginal microbiome and gynecological neoplasms. Several recent studies have shown a potential link between the vaginal microbiome and the risk of developing cervical cancer from human papillomavirus (HPV) infection. This study aimed to compare the prevalence and abundance of various lactic acid bacteria species (LABs) in vaginal swabs from healthy controls and patients with abnormal Pap smear results.

Methods

The study included 100 women (79 patients with abnormal cervical Pap smear results and 21 controls) from whom vaginal swabs were collected. Real-time quantitative PCR was used to determine seven lactic acid bacteria (LAB) species and their quantities.

Results

Most patients were colonized by two Lactobacillus species, primarily Lactobacillus gasseri (93%) and L. crispatus (83%). Patient age and place of residence were associated with the diversity of LAB in the vaginal microbiota. The abundance of L. delbrueckii in the vaginal microbiota increased, whereas the abundance of L. gasseri abundance decreased, with patient age. Lactobacillus acidophilus and Limosilactobacillus fermentum were significantly more often detected in patients living in rural versus urban areas. Statistical analysis did not show any significant differences in LAB between groups of patients with various changes on smear tests.

Discussion

The degree of dysplastic changes in the endothelium or the presence of a group of atypical cervical stratified epithelial cells was not associated with significant changes in the studied vaginal bacteria.

The effect of normalizing vaginal microbiome using Lactovag in improving pregnancy outcomes in frozen embryo transfer cycles: a randomized clinical trial

INTRODUCTION

Successful frozen-thawed embryo transfer (FTET) depends on multiple factors among which the woman's vaginal microbiota has recently been considered important. Using probiotic products, such as Lactovag in infertile women, the vaginal microbiome can become close to the healthy status.

OBJECTIVES

The aim of this study was to evaluate the effect of Lactovag on normalizing vaginal microbiome, as well as its role in improving pregnancy outcomes in FTET cycles.

PATIENTS AND METHODS

This randomized blinded clinical trial was conducted on 103 patients undergoing Assisted Reproductive Technology (ART) treatment at a tertiary university-based hospital between January and August of 2019. In the experiment group, the vaginal suppository Lactavag was prescribed, whereas in the control group, patients did not receive any microbiome supplements. Then, the pregnancy rate was compared in the two groups.

RESULTS

There were no significant differences in baseline characteristics between the two study groups (p > 0.05). Positive B hCG was present in 28% (n = 26) of women, clinical pregnancy was achieved in 23.4% (n = 22) of them and fetal heart rate was detected in 21.3% (n = 20). These proportions were higher in the Lactovag group, although these differences were not significant (p > 0.05). Results showed that although transferring fetuses with grade A increased the odds of pregnancy with 1.53 (p = 0.001) folds, this ratio would be improved using Lactovag;1.68 (P value = 0.008).

CONCLUSIONS

It seems that the vaginal microbiota critically interplays with women's health and reproduction. A probiotic agent such as Lactovag can be useful in normalizing this environment and improving pregnancy outcomes in infertile women.

Under conditions closely mimicking vaginal fluid, Lactobacillus jensenii strain 62B produces a bacteriocin-like inhibitory substance that targets and eliminates Gardnerella species

Within the vaginal ecosystem, lactobacilli and Gardnerella spp. likely interact and influence each other's growth, yet the details of this interaction are not clearly defined. Using medium simulating vaginal fluid and a two-chamber co-culturing system to prevent cell-to-cell contact between the bacteria, we examined the possibility that Lactobacillus jensenii 62B (Lj 62B) and/or G. piotii (Gp) JCP8151B produce extracellular factors through which they influence each other's viability. By 24 h post-inoculation (hpi) in the co-culture system and under conditions similar to the vaginal environment - pH 5.0, 37 °C, and 5% CO2, Lj 62B viability was not affected but Gp JCP8151B had been eliminated. Cell-free supernatant harvested from Lj 62B cultures (Lj-CFS) at 20 hpi, but not 16 hpi, also eliminated Gp JCP8151B growth. Neither lactic acid nor H2O2 production by Lj 62B was responsible for this effect. The Lj-CFS did not affect viability of three species of lactobacilli or eight species of Gram-positive and Gram-negative uropathogens but eliminated viability of eight different strains of Gardnerella spp. Activity of the inhibitory factor within Lj-CFS was abolished by protease treatment and reduced by heat treatment suggesting it is most likely a bacteriocin-like protein; fractionation revealed that the factor has a molecular weight within the 10-30 kDa range. These results suggest that, in medium mimicking vaginal fluid and growth conditions similar to the vaginal environment, Lj 62B produces a potential bacteriocin-like inhibitory substance (Lj-BLIS) that clearly targets Gardnerella spp. strains. Once fully characterized, Lj-BLIS may be a potential treatment for Gardnerella-related BV that does not alter the vaginal microflora.

Recent advances in understanding of multifaceted changes in the vaginal microenvironment: implications in vaginal health and therapeutics

The vagina endures multifaceted changes from neonatal to menopausal phases due to hormonal flux, metabolite deposition, and microbial colonization. These features have important implications in women's health. Several pre-factors show dynamic characteristics according to the phases that shift the vaginal microbiota from anaerobes to aerobes which is a hallmark of healthy vaginal environment. These factors include oestrogen levels, glycogen deposition, and vaginal microstructure. In the adult phase, Lactobacillus is highly dominant and regulates pH, adherence, aggregation, immune modulation, synthesis of bacteriocins, and biosurfactants (BSs) which are antagonistic to pathogens. Maternal factors are protective by favouring the colonization of lactobacilli in the vagina in the neonatal phase, which diminishes with age. The dominance of lactobacilli and dysbiosis in the adult phase depends on intrinsic and extrinsic factors in women, which vary between ethnicities. Recent developments in probiotics used against vaginal microbiome dysbiosis have shown great promise in restoring the normal microbiota including preventing the loss of beneficial bacteria. However, further in-depth studies are warranted to ensure long-term protection by probiotics. This review highlights various aspects of the vaginal microenvironment in different phases of growth and diverse ethnicities. Furthermore, it discusses future trends for formulating more effective population-specific probiotics and implications of paraprobiotics and postbiotics as effective therapeutics.

Vaginal microbial dynamics and pathogen colonization in a humanized microbiota mouse model

Vaginal microbiota composition is associated with differential risk of urogenital infection. Although vaginal Lactobacillus spp. are thought to confer protection through acidification, bacteriocin production, and immunomodulation, lack of an in vivo model system that closely resembles the human vaginal microbiota remains a prominent barrier to mechanistic discovery. We performed 16S rRNA amplicon sequencing of wildtype C57BL/6J mice, commonly used to study pathogen colonization, and found that the vaginal microbiome composition varies highly both within and between colonies from three distinct vivaria. Because of the strong influence of environmental exposure on vaginal microbiome composition, we assessed whether a humanized microbiota mouse ( HMb mice) would model a more human-like vaginal microbiota. Similar to humans and conventional mice, HMb mice vaginal microbiota clustered into five community state types ( h mCST). Uniquely, HMb mice vaginal communities were frequently dominated by Lactobacilli or Enterobacteriaceae . Compared to genetically-matched conventional mice, HMb mice were less susceptible to uterine ascension by urogenital pathobionts group B Streptococcus (GBS) and Prevotella bivia , but no differences were observed with uropathogenic E. coli . Specifically, vaginal Enterobacteriaceae and Lactobacillus were associated with the absence of uterine GBS. Anti-GBS activity of HMb mice vaginal E. coli and L. murinus isolates, representing Enterobacteriaceae and Lactobacillus respectively, were characterized in vitro and in vivo . Although L. murinus reduced GBS growth in vitro , vaginal pre-inoculation with HMb mouse-derived E. coli , but not L. murinus , conferred protection against vaginal GBS burden. Overall, the HMb mice are an improved model to elucidate the role of endogenous microbes in conferring protection against urogenital pathogens.

IMPORTANCE

An altered vaginal microbiota, typically with little to no levels of Lactobacillus , is associated with increased susceptibility to urogenital infections, although mechanisms driving this vulnerability are not fully understood. Despite known inhibitory properties of Lactobacillus against urogenital pathogens, clinical studies with Lactobacillus probiotics have shown mixed success. In this study, we characterize the impact of the vaginal microbiota on urogenital pathogen colonization using a humanized microbiota mouse model that more closely mimics the human vaginal microbiota. We found several vaginal bacterial taxa that correlated with reduced pathogen levels but showed discordant effects in pathogen inhibition between in vitro and in vivo assays. We propose that this humanized microbiota mouse platform is an improved model to describe the role of the vaginal microbiota in protection against urogenital pathogens. Furthermore, this model will be useful in testing efficacy of new probiotic strategies in the complex vaginal environment.

The female reproductive tract microbiotas, inflammation, and gynecological conditions

The intricate interactions between the host cells, bacteria, and immune components that reside in the female reproductive tract (FRT) are essential in maintaining reproductive tract homeostasis. Much of our current knowledge surrounding the FRT microbiota relates to the vaginal microbiota, where ‘health’ has long been associated with low bacterial diversity and Lactobacillus dominance. This concept has recently been challenged as women can have a diverse vaginal microbial composition in the absence of symptomatic disease. The structures of the upper FRT (the endocervix, uterus, Fallopian tubes, and ovaries) have distinct, lower biomass microbiotas than the vagina; however, the existence of permanent microbiotas at these sites is disputed. During homeostasis, a balance exists between the FRT bacteria and the immune system that maintains immune quiescence. Alterations in the bacteria, immune system, or local environment may result in perturbances to the FRT microbiota, defined as dysbiosis. The inflammatory signature of a perturbed or “dysbiotic” FRT microbiota is characterized by elevated concentrations of pro-inflammatory cytokines in cervical and vaginal fluid. It appears that vaginal homeostasis can be disrupted by two different mechanisms: first, a shift toward increased bacterial diversity can trigger vaginal inflammation, and second, local immunity is altered in some manner, which disrupts the microbiota in response to an environmental change. FRT dysbiosis can have negative effects on reproductive health. This review will examine the increasing evidence for the involvement of the FRT microbiotas and inflammation in gynecologic conditions such as endometriosis, infertility, and endometrial and ovarian cancer; however, the precise mechanisms by which bacteria are involved in these conditions remains speculative at present. While only in their infancy, the use of antibiotics and probiotics to therapeutically alter the FRT microbiota is being studied and is discussed herein. Our current understanding of the intimate relationship between immunity and the FRT microbiota is in its early days, and more research is needed to deepen our mechanistic understanding of this relationship and to assess how our present knowledge can be harnessed to assist in diagnosis and treatment of gynecologic conditions.

Role of Vaginal Mucosa, Host Immunity and Microbiota in Vulvovaginal Candidiasis

Vulvovaginal candidiasis (VVC) is a prevalent gynaecological disease characterised by vaginal wall inflammation that is caused by Candida species. VVC impacts almost three-quarters of all women throughout their reproductive years. As the vaginal mucosa is the first point of contact with microbes, vaginal epithelial cells are the first line of defence against opportunistic Candida infection by providing a physical barrier and mounting immunological responses. The mechanisms of defence against this infection are displayed through the rapid shedding of epithelial cells, the presence of pattern recognition receptors, and the release of inflammatory cytokines. The bacterial microbiota within the mucosal layer presents another form of defence mechanism within the vagina through acidic pH regulation, the release of antifungal peptides and physiological control against dysbiosis. The significant role of the microbiota in maintaining vaginal health promotes its application as one of the potential treatment modalities against VVC with the hope of alleviating the burden of VVC, especially the recurrent disease. This review discusses and summarises current progress in understanding the role of vaginal mucosa and host immunity upon infection, together with the function of vaginal microbiota in VVC.

Cervicovaginal DNA Virome Alterations Are Associated with Genital Inflammation and Microbiota Composition

While the link between the cervicovaginal bacterial microbiome, human papillomavirus (HPV) infection, and cervical cancer is recognized (P. Łaniewski, D. Barnes, A. Goulder, H. Cui, et al., Sci. Rep. 8:7593, 2018, http://dx.doi.org/10.1038/s41598-018-25879-7; A. Mitra, D. A. MacIntyre, Y. S. Lee, A. Smith, et al., Sci. Rep. 5:16865, 2015, http://dx.doi.org/10.1038/srep16865; A. Mitra, D. A. MacIntyre, J. R. Marchesi, Y. S. Lee, et al., Microbiome 4:58, 2016, http://dx.doi.org/10.1186/s40168-016-0203-0; J. Norenhag, J. Du, M. Olovsson, H. Verstraelen, et al., BJOG, 127:171-180, 2020, http://dx.doi.org/10.1111/1471-0528.15854; E. O. Dareng, B. Ma, A. O. Famooto, S. N. Adebamowo, et al., Epidemiol. Infect. 144:123-137, 2016, http://dx.doi.org/10.1017/S0950268815000965; A. Audirac-Chalifour, K. Torres-Poveda, M. Bahena-Roman, J. Tellez-Sosa et al., PLoS One 11:e0153274, 2016, http://dx.doi.org/10.1371/journal.pone.0153274; M. Di Paola, C. Sani, A. M. Clemente, A. Iossa, et al., Sci. Rep. 7:10200, 2017, http://dx.doi.org/10.1038/s41598-017-09842-6), the role of the cervicovaginal virome remains poorly understood. In this pilot study, we conducted metagenomic next-generation sequencing of cervicovaginal lavage specimens to investigate the relationship between the cervicovaginal DNA virome, bacterial microbiome, genital inflammation, and HPV infection. Specific virome alterations were associated with features of the local microenvironment related to HPV persistence and progression to cervical cancer. Cervicovaginal viromes clustered distinctly by genital inflammation state. Genital inflammation was associated with decreased virome richness and alpha diversity and an increased abundance of Anelloviridae species from the genus Alphatorquevirus. Lactobacillus bacteriophages were closely associated with increased Lactobacillus abundance, consistent with phage-host relationships. Interestingly, bacteria-bacteriophage transkingdom interactions were linked to genital inflammation and showed specific interactions with bacterial vaginosis-associated bacteria, including Gardnerella, Prevotella, and Sneathia. Taken together, our results reveal prominent virome interactions with features of the cervicovaginal microenvironment that are associated with HPV and cervical cancer. These findings expand our understanding of the cervicovaginal host-microbiome interactions in women's health. IMPORTANCE HPV infection is an established risk factor for cervical cancer. However, more broadly, the role of the cervicovaginal virome in cervical cancer progression is not well understood. Here, we identified cervicovaginal DNA virome alterations associated with local microenvironment factors (vaginal microbiota and genital inflammation) that influence HPV persistence and progression to cervical cancer. These findings indicate that the cervicovaginal virome plays an important role in women's health.

Systematic Review: The Neovaginal Microbiome

OBJECTIVE

To review neovaginal colonization and inflammatory patterns, and factors that may impact this.

METHODS

A systematic review of the neovaginal microbiome was conducted in concordance with PRISMA guidelines through October 2021.

RESULTS

Thirteen articles were included, totaling 458 patients. Neovaginal constructions were most commonly performed with penile and scrotal skin grafts, sigmoid segments, and peritoneal grafts. The neovaginal microflora identified were generally polymicrobial and shared similarities with the native tissue. Nine studies identified Lactobacillus: 5/6 for penile skin, 1/3 for sigmoid, 1/1 for peritoneum, and 2/3 for other graft types, suggesting that the neovagina may support Lactobacillus either innately, via rectal migration or oral probiotic supplementation. A polymicrobial, bacterial vaginosis-like environment was found in nine studies. Inflammatory markers were also described: 2/6 for penile skin, 2/3 for sigmoid, 0/1 for peritoneum, and 1/3 for other graft types. Scant data were available on the impact of postsurgical duration, oral hormones, dilating, sexual practices, or douching on the neovaginal microbiome.

CONCLUSION

Understanding and optimizing the polymicrobial neovaginal microenvironment may improve surgical outcomes, specifically inflammatory, pain, and infectious. Future research should focus on standardizing testing and classification systems, and treating neovaginal dysbiosis.

Recent Advances in Understanding the Structure and Function of the Human Microbiome

Trillions of microbes live within our bodies in a deep symbiotic relationship. Microbial populations vary across body sites, driven by differences in the environment, immunological factors, and interactions between microbial species. Major advances in genome sequencing enable a better understanding of microbiome composition. However, most of the microbial taxa and species of the human microbiome are still unknown. Without revealing the identity of these microbes as a first step, we cannot appreciate their role in human health and diseases. A shift in the microbial balance, termed dysbiosis, is linked to a broad range of diseases from simple colitis and indigestion to cancer and dementia. The last decade has witnessed an explosion in microbiome research that led to a better understanding of the microbiome structure and function. This understanding leads to potential opportunities to develop next-generation microbiome-based drugs and diagnostic biomarkers. However, our understanding is limited given the highly personalized nature of the microbiome and its complex and multidirectional interactions with the host. In this review, we discuss: (1) our current knowledge of microbiome structure and factors that shape the microbial composition, (2) recent associations between microbiome dysbiosis and diseases, and (3) opportunities of new microbiome-based therapeutics. We analyze common themes, promises, gaps, and challenges of the microbiome research.

Changes in the Microbiome of Vaginal Fluid after Menopause in Korean Women

Various microorganisms reside in the human vagina; the vaginal microbiome is closely linked to both vaginal and general health, and for this reason, microbiome studies of the vagina are an area of research. In this study, we analyzed the vaginal microbiome of women before and after menopause to further increase our understanding of the vaginal microbiome and its contribution to general health. We did a 16s rRNA gene-based metagenomic analysis on the vaginal fluids of 11 premenopausal and 19 postmenopausal women in Korea. We confirmed that the taxonomic composition was significantly different between the two groups. In postmenopausal women, species richness was significantly decreased, but species diversity was significantly increased. In particular, among the taxonomic components corresponding to all taxon ranks of the vaginal microbiome, a reduction in Lactobacillus taxa after menopause contributed the most to the difference between the two groups. In addition, we confirmed through metabolic analysis that the lactic-acid concentration was also decreased in the vaginal fluid of women after menopause. Our findings on the correlation between menopause and the microbiome could help diagnose menopause and enhance the prevention and treatment diseases related to menopause.

Prevalence and Antibiotic Resistance Profile of Bacterial Pathogens in Aerobic Vaginitis: A Retrospective Study in Italy

Aerobic vaginitis (AV) is a vaginal infectious condition, characterized by a high inflammatory response and/or signs of epithelial atrophy, a decrease in the amount of Lactobacillus spp. and an increase in enteric origin bacteria. AV, often misdiagnosed, is difficult to treat due to the emerging spread of multi-drug resistant bacterial strains. The present study aimed to define the prevalence of AV, to detect causative bacteria and their antimicrobial resistance pattern. Women 10-95 years old, admitted to San Giovanni di Dio e Ruggi d'Aragona Hospital, Salerno, Italy (in the years 2015-2019) are included in the study. Bacterial identification and antibiotic susceptibility tests were carried out by VITEK^® 2. Among 2069 patients, 1176 tested positive for microbial growth. A higher incidence of infection was found in the 55-64 age group. Among the pathogenic strains, 50.4% were Gram-negative, and 49.6% were Gram-positive. Escherichia coli (E. coli) (32.5%) was the most representative strain, followed by Enterococcus faecalis (E. faecalis) (29.4%), Klebsiella pneumoniae (K. pneumoniae) (7.8%) and Enterococcus faecium (E. faecium) (7.7%). E. coli showed high sensitivity to carbapenems and amikacin. K. pneumoniae carbapenems resistance was fluctuating over time. Alarming resistance to vancomycin was not recorded for Enterococci. Both strains were sensitive to teicoplanin, linezolid and tigecycline. Proper diagnosis and an effective therapeutic approach are needed to improve AV management.

Forensic Analysis of Human Microbiome in Skin and Body Fluids Based on Geographic Location

High-throughput DNA sequencing technologies have facilitated the in silico forensic analysis of human microbiome. Specific microbial species or communities obtained from the crime scene provide evidence of human contacts and their body fluids. The microbial community is influenced by geographic, ethnic, lifestyle, and environmental factors such as urbanization. An understanding of the effects of these external stressors on the human microbiome and determination of stable and changing elements are important in selecting appropriate targets for investigation. In this study, the Forensic Microbiome Database (FMD) (http://www.fmd.jcvi.org) containing the microbiome data of various locations in the human body in 35 countries was used. We focused on skin, saliva, vaginal fluid, and stool and found that the microbiome distribution differed according to the body part as well as the geographic location. In the case of skin samples, Staphylococcus species were higher than Corynebacterium species among Asians compared with Americans. Holdemanella and Fusobacterium were specific in the saliva of Koreans and Japanese populations. Lactobacillus was found in the vaginal fluids of individuals in all countries, whereas Serratia and Enterobacter were endemic to Bolivia and Congo, respectively. This study is the first attempt to collate and describe the observed variation in microbiomes from the forensic microbiome database. As additional microbiome databases are reported by studies worldwide, the diversity of the applications may exceed and expand beyond the initial identification of the host.

The Vaginal Microbiome: A Long Urogenital Colonization Throughout Woman Life

Vaginal microbial niche is a dynamic ecosystem, composed by more than 200 bacterial species which are influenced by genes, ethnic background and environmental-behavioral factors. Several lines of evidence have well documented that vaginal microbiome constantly changes over the course of woman’s life, so to exert an important impact on woman quality of life, from newborn to post-menopausal ages. This review aims at analyzing the role of vaginal microbiome in the maintenance of woman’s homeostasis and at tracking critical changes that commonly occur across woman’s lifetime. The role of hormone replacement therapy in the modulation of vaginal microbiome composition and in the improvement of vaginal wellness in postmenopausal women with decreasing levels of circulating estrogen is discussed.

Probiotic Lacticaseibacillus rhamnosus GR-1 and Limosilactobacillus reuteri RC-14 as an Adjunctive Treatment for Bacterial Vaginosis Do Not Increase the Cure Rate in a Chinese Cohort: A Prospective, Parallel-Group, Randomized, Controlled Study

The purpose of this study was to evaluate the effectiveness of metronidazole and oral probiotics adjunct to metronidazole in the treatment of bacterial vaginosis (BV). One hundred and twenty-six Chinese women with BV were enrolled in this parallel, controlled trial, and were randomly assigned into two study arms: the metronidazole group, which was prescribed metronidazole vaginal suppositories for 7 days, and the adjunctive probiotic group, which received Lacticaseibacillus rhamnosus GR-1 and Limosilactobacillus reuteri RC-14 orally for 30 days as an adjunct to metronidazole. Clinical symptoms and Nugent scores at the initial visit, 30 days and 90 days were compared. There was no significant difference of the 30-day total cure rate between the adjunctive probiotic group (57.69%) and the metronidazole group (59.57%), with an odds ratio (OR) of 0.97 (95% confidence interval (CI), 0.70 to 1.35, p-value = 0.04), or of the 90-day total cure rate (36.54% vs. 48.94%, OR, 0.75; 95% CI, 0.47 to 1.19; p-value = 0.213). Also, no significant difference of the vaginal and faecal microbial diversity and structure between the two groups at 0, 30 or 90 days were shown based on 16S rRNA sequences. The probiotic species were rarely detected in either the vaginal microbiota or the faecal microbiota after administration which may revealed the cause of noneffective of oral probiotics. No serious adverse effects were reported in the trial. The study indicated that oral probiotic adjunctive treatment did not increase the cure rate of Chinese BV patients compared to metronidazole.

Finding a Balance in the Vaginal Microbiome: How Do We Treat and Prevent the Occurrence of Bacterial Vaginosis?

Bacterial vaginosis (BV) has been reported in one-third of women worldwide at different life stages, due to the complex balance in the ecology of the vaginal microbiota. It is a common cause of abnormal vaginal discharge and is associated with other health issues. Since the first description of anaerobic microbes associated with BV like Gardnerella vaginalis in the 1950s, researchers have stepped up the game by incorporating advanced molecular tools to monitor and evaluate the extent of dysbiosis within the vaginal microbiome, particularly on how specific microbial population changes compared to a healthy state. Moreover, treatment failure and BV recurrence rate remain high despite the standard antibiotic treatment. Consequently, researchers have been probing into alternative or adjunct treatments, including probiotics or even vaginal microbiota transplants, to ensure successful treatment outcomes and reduce the colonization by pathogenic microbes of the female reproductive tract. The current review summarizes the latest findings in probiotics use for BV and explores the potential of vaginal microbiota transplants in restoring vaginal health.

The Vaginal Microbiota, Bacterial Biofilms and Polymeric Drug-Releasing Vaginal Rings

The diversity and dynamics of the microbial species populating the human vagina are increasingly understood to play a pivotal role in vaginal health. However, our knowledge about the potential interactions between the vaginal microbiota and vaginally administered drug delivery systems is still rather limited. Several drug-releasing vaginal ring products are currently marketed for hormonal contraception and estrogen replacement therapy, and many others are in preclinical and clinical development for these and other clinical indications. As with all implantable polymeric devices, drug-releasing vaginal rings are subject to surface bacterial adherence and biofilm formation, mostly associated with endogenous microorganisms present in the vagina. Despite more than 50 years since the vaginal ring concept was first described, there has been only limited study and reporting around bacterial adherence and biofilm formation on rings. With increasing interest in the vaginal microbiome and vaginal ring technology, this timely review article provides an overview of: (i) the vaginal microbiota, (ii) biofilm formation in the human vagina and its potential role in vaginal dysbiosis, (iii) mechanistic aspects of biofilm formation on polymeric surfaces, (iv) polymeric materials used in the manufacture of vaginal rings, (v) surface morphology characteristics of rings, (vi) biomass accumulation and biofilm formation on vaginal rings, and (vii) regulatory considerations.

Vaginal microbiome analysis of healthy women during different periods of gestation

To assess the vaginal microbiome throughout full-term uncomplicated pregnancy, a longitudinal study was designed for 12 healthy women who had prepared to become pregnant and then delivered at term (38–42 weeks) without complications. The vaginal microbial community was studied at pre-pregnancy, 8–12, 24–28, 37–38 weeks of gestation, and puerperium, using hypervariable tag sequencing of the V3–V4 region of the 16S rRNA gene. Sequencing produced approximately 10 million reads on the Illumina MiSeq. Members of the Firmicutes phyla were prevailing before and during pregnancy periods, and the proportion was quite as Proteobacteria until puerperium. Lactobacillus genus was abundant before and during pregnancy, but post-delivery vaginal microflora variety turned diverse. The species-level analysis revealed that a healthy vaginal microbiome before or during pregnancy was prominently dominated by Lactobacillus crispatus. Furthermore, PCoA analysis revealed for differences in the bacterial community composition between the two levels of Lactobacillus species in pre-pregnancy and pregnancy period (PC1 contribution of 58.46%, PC3 contribution of 8.64%). Based on the taxonomic and PCoA analysis, we found that L. crispatus was dominant in the vaginal microflora of healthy women before or during pregnancy, but at the puerperium, the status changed leading to decreased abundance of protective Lactobacillus species that made vaginal micro-ecological barrier vulnerable to diseases. Additionally, vaginal pH was an important environmental property affecting the vaginal microbial community.

Understanding Human Microbiota Offers Novel and Promising Therapeutic Options against Candida Infections

Human fungal pathogens particularly of Candida species are one of the major causes of hospital acquired infections in immunocompromised patients. The limited arsenal of antifungal drugs to treat Candida infections with concomitant evolution of multidrug resistant strains further complicates the management of these infections. Therefore, deployment of novel strategies to surmount the Candida infections requires immediate attention. The human body is a dynamic ecosystem having microbiota usually involving symbionts that benefit from the host, but in turn may act as commensal organisms or affect positively (mutualism) or negatively (pathogenic) the physiology and nourishment of the host. The composition of human microbiota has garnered a lot of recent attention, and despite the common occurrence of Candida spp. within the microbiota, there is still an incomplete picture of relationships between Candida spp. and other microorganism, as well as how such associations are governed. These relationships could be important to have a more holistic understanding of the human microbiota and its connection to Candida infections. Understanding the mechanisms behind commensalism and pathogenesis is vital for the development of efficient therapeutic strategies for these Candida infections. The concept of host-microbiota crosstalk plays critical roles in human health and microbiota dysbiosis and is responsible for various pathologies. Through this review, we attempted to analyze the types of human microbiota and provide an update on the current understanding in the context of health and Candida infections. The information in this article will help as a resource for development of targeted microbial therapies such as pre-/pro-biotics and microbiota transplant that has gained advantage in recent times over antibiotics and established as novel therapeutic strategy.

Modeling transfer of vaginal microbiota from mother to infant in early life

Early-life microbiota has been linked to the development of chronic inflammatory diseases. It has been hypothesized that maternal vaginal microbiota is an important initial seeding source and therefore might have lifelong effects on disease risk. To understand maternal vaginal microbiota's role in seeding the child's microbiota and the extent of delivery mode-dependent transmission, we studied 665 mother-child dyads from the COPSAC₂₀₁₀ cohort. The maternal vaginal microbiota was evaluated twice in the third trimester and compared with the children's fecal (at 1 week, 1 month, and 1 year of age) and airway microbiota (at 1 week, 1 month, and 3 months). Based on the concept of weighted transfer ratios (WTRs), we have identified bacterial orders for which the WTR displays patterns indicate persistent or transient transfer from the maternal vaginal microbiome, as well as orders that are shared at later time points independent of delivery mode, indicating a common reservoir.

Hypothetical roadmap towards endometriosis: prenatal endocrine-disrupting chemical pollutant exposure, anogenital distance, gut-genital microbiota and subclinical infections

BACKGROUND

Endometriosis is a gynaecological hormone-dependent disorder that is defined by histological lesions generated by the growth of endometrial-like tissue out of the uterus cavity, most commonly engrafted within the peritoneal cavity, although these lesions can also be located in distant organs. Endometriosis affects ~10% of women of reproductive age, frequently producing severe and, sometimes, incapacitating symptoms, including chronic pelvic pain, dysmenorrhea and dyspareunia, among others. Furthermore, endometriosis causes infertility in ~30% of affected women. Despite intense research on the mechanisms involved in the initial development and later progression of endometriosis, many questions remain unanswered and its aetiology remains unknown. Recent studies have demonstrated the critical role played by the relationship between the microbiome and mucosal immunology in preventing sexually transmitted diseases (HIV), infertility and several gynaecologic diseases.

OBJECTIVE AND RATIONALE

In this review, we sought to respond to the main research question related to the aetiology of endometriosis. We provide a model pointing out several risk factors that could explain the development of endometriosis. The hypothesis arises from bringing together current findings from large distinct areas, linking high prenatal exposure to environmental endocrine-disrupting chemicals with a short anogenital distance, female genital tract contamination with the faecal microbiota and the active role of genital subclinical microbial infections in the development and clinical progression of endometriosis.

SEARCH METHODS

We performed a search of the scientific literature published until 2019 in the PubMed database. The search strategy included the following keywords in various combinations: endometriosis, anogenital distance, chemical pollutants, endocrine-disrupting chemicals, prenatal exposure to endocrine-disrupting chemicals, the microbiome of the female reproductive tract, microbiota and genital tract, bacterial vaginosis, endometritis, oestrogens and microbiota and microbiota-immune system interactions.

OUTCOMES

On searching the corresponding bibliography, we found frequent associations between environmental endocrine-disrupting chemicals and endometriosis risk. Likewise, recent evidence and hypotheses have suggested the active role of genital subclinical microbial infections in the development and clinical progression of endometriosis. Hence, we can envisage a direct relationship between higher prenatal exposure to oestrogens or estrogenic endocrine-disrupting compounds (phthalates, bisphenols, organochlorine pesticides and others) and a shorter anogenital distance, which could favour frequent postnatal episodes of faecal microbiota contamination of the vulva and vagina, producing cervicovaginal microbiota dysbiosis. This relationship would disrupt local antimicrobial defences, subverting the homeostasis state and inducing a subclinical inflammatory response that could evolve into a sustained immune dysregulation, closing the vicious cycle responsible for the development of endometriosis.

WIDER IMPLICATIONS

Determining the aetiology of endometriosis is a challenging issue. Posing a new hypothesis on this subject provides the initial tool necessary to design future experimental, clinical and epidemiological research that could allow for a better understanding of the origin of this disease. Furthermore, advances in the understanding of its aetiology would allow the identification of new therapeutics and preventive actions.

Effect of Antibiotics on Gut and Vaginal Microbiomes Associated with Cervical Cancer Development in Mice

Antibiotics affect microbial diversity in the gut, leading to dysbiosis and impaired immunity. However, the impact of antibiotics on microbial communities at other sites, such as vagina is less understood. It is also not clear whether changes induced by antibiotics in both microbiomes affect the development of cervical cancer. In this study, we utilized the murine model to evaluate these questions. We show that oral application of broad-spectrum antibiotics in mice changed not only diversity, but composition and sharing of gut and vaginal microbiomes in mice and influenced cervical cancer development in an orthotopic tumor model. Antibiotics decreased richness and diversity indexes in the gut but increased them in the vagina. Some beneficial taxa, such as Bacteroides, Ruminococcaceae, and Lachnospiraceae increased their abundance in the vagina while other pathogenic species, such as Proteobacteria, were decreased. As a result of the changes, mice with greater richness and diversity of the vaginal microbiome after antibiotics exposure were less likely developed tumors. No association between richness and diversity of the gut microbiome and tumor development was identified.

Vaginal Microbiome-Based Bacterial Signatures for Predicting the Severity of Cervical Intraepithelial Neoplasia

Although emerging evidence revealed that the gut microbiome served as a tool and as biomarkers for predicting and detecting specific cancer or illness, it is yet unknown if vaginal microbiome-derived bacterial markers can be used as a predictive model to predict the severity of CIN. In this study, we sequenced V3 region of 16S rRNA gene on vaginal swab samples from 66 participants (24 CIN 1−, 42 CIN 2+ patients) and investigated the taxonomic composition. The vaginal microbial diversity was not significantly different between the CIN 1− and CIN 2+ groups. However, we observed Lactobacillus amylovorus dominant type (16.7%), which does not belong to conventional community state type (CST). Moreover, a minimal set of 33 bacterial species was identified to maximally differentiate CIN 2+ from CIN 1− in a random forest model, which can distinguish CIN 2+ from CIN 1− (area under the curve (AUC) = 0.952). Among the 33 bacterial species, Lactobacillus iners was selected as the most impactful predictor in our model. This finding suggests that the random forest model is able to predict the severity of CIN and vaginal microbiome may play a role as biomarker.

Community State Types of Vaginal Microbiota and Four Types of Abnormal Vaginal Microbiota in Pregnant Korean Women

Abnormal vaginal microbiota (AVM), including bacterial vaginosis (BV), is caused by a microbiota imbalance. Nugent scoring is the gold standard for the laboratory diagnosis of BV; however, it is somewhat subjective to interpret, and challenging to distinguish bacteria. Hence, there is a need for improved technologies for the accurate diagnosis of AVM. To this end, next-generation sequencing (NGS) technology has been shown to yield comprehensive information on the pathophysiology of AVM. Hence, to evaluate the relationship between microbiota composition and the pathophysiology of AVM and its clinical significance, we characterized vaginal swab samples from 212 pregnant Korean women using both Nugent scoring and NGS analysis. Of these, the Nugent scoring identified 175 subjects (82.5%; 175/212) with normal flora (NF), 20 (9.4%; 20/212) with intermediate flora (IF), and 17 (8.0%; 17/212) with BV. NGS analysis followed by the characterization of vaginal microbiota composition, as represented by alpha and beta diversity, revealed the relative abundance of specific bacterial taxa at the genus and species level. Moreover, we identified all five predominant community state types (CSTs) along with three smaller CSTs. Analysis of the vaginal microbiota revealed the dominance of one or two Lactobacillus spp. in the NF group. Meanwhile, the IF and BV groups were dominated by the genera Gardnerella, Prevotella, and Atopobium. These two groups also showed higher alpha diversity than the NF group (p < 0.05). Principal coordinate analysis (PCoA) indicated that the NF group was significantly different from the AVM groups (p < 0.05), whereas no significant difference was observed between IF and BV groups (p = 0.25). Lastly, to investigate the characteristics of vaginal microbiota based on taxonomic composition, the IF and BV groups (AVM groups) were reclassified using the unweighted pair group method with arithmetic mean (UPGMA) clustering. Consequently, they were reclassified into BV1 (Lactobacillus iners-dominated), BV2-1 (Bifidobacterium breve-dominated), BV2-2 (Gardnerella vaginalis s1 or s2 and Atopobium vaginae-dominated), and BV3 [mixed population of G. vaginalis, L. iners, and other bacteria (p < 0.05)]. Collectively, these findings could serve to advance the current understanding regarding AVM pathophysiology.

Probiotics in Medicine: A Long Debate

During the last years probiotics gained the attention of clinicians for their use in the prevention and treatment of multiple diseases. Probiotics main mechanisms of action include enhanced mucosal barrier function, direct antagonism with pathogens, inhibition of bacterial adherence and invasion capacity in the intestinal epithelium, boosting of the immune system and regulation of the central nervous system. It is accepted that there is a mutual communication between the gut microbiota and the liver, the so-called “microbiota-gut-liver axis” as well as a reciprocal communication between the intestinal microbiota and the central nervous system through the “microbiota-gut-brain axis.” Moreover, recently the “gut-lung axis” in bacterial and viral infections is considerably discussed for bacterial and viral infections, as the intestinal microbiota amplifies the alveolar macrophage activity having a protective role in the host defense against pneumonia. The importance of the normal human intestinal microbiota is recognized in the preservation of health. Disease states such as, infections, autoimmune conditions, allergy and other may occur when the intestinal balance is disturbed. Probiotics seem to be a promising approach to prevent and even reduce the symptoms of such clinical states as an adjuvant therapy by preserving the balance of the normal intestinal microbiota and improving the immune system. The present review states globally all different disorders in which probiotics can be given. To date, Stronger data in favor of their clinical use are provided in the prevention of gastrointestinal disorders, antibiotic-associated diarrhea, allergy and respiratory infections. We hereby discuss the role of probiotics in the reduction of the respiratory infection symptoms and we focus on the possibility to use them as an adjuvant to the therapeutic approach of the pandemic COVID-19. Nevertheless, it is accepted by the scientific community that more clinical studies should be undertaken in large samples of diseased populations so that the assessment of their therapeutic potential provide us with strong evidence for their efficacy and safety in clinical use.

Identification and Sensitivity of Vaginal and Probiotic Lactobacillus species to Urinary Antibiotics

Objectives  Healthy vaginal microbiota is mainly dominated by Lactobacillus species namely L. crispatus , L. gasseri , L. jensenii , and L. iners . Lactobacilli are thought to play an important role in the prevention of urogenital infections, and Lactobacillus probiotics to restore and/or maintain vaginal health has been advocated. These can interfere with the adherence, growth, and colonization by uropathogenic bacteria, thus reducing the risk of urinary tract infection (UTI). This study aims to isolate and evaluate the susceptibility of healthy vaginal and probiotic Lactobacillus spp. to urinary antibiotics. Materials and methods  A total of 50 premenopausal, nonmenstruating women with no symptoms of vaginal infection or UTI or antimicrobial use in the past 2 weeks were enrolled. Two high vaginal swabs were collected for Nugent's scoring and anaerobic culture. Colonies yielding gram-positive rods were confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Lactobacillus strains in a vaginal probiotic tablet were also isolated, and the sensitivity of both sets to urinary antibiotics was determined. Results  A total of 29 Lactobacillus spp. were isolated, including L. crispatus (15), L. gasseri (5), L. vaginalis (4), L. paracasei (2), L. curvatus (1), L. fermentum (1), and L. paraplantarum (1). All strains were susceptible to nitrofurantoin and resistant to norfloxacin, gentamicin, and cotrimoxazole (except L. paracasei ). The probiotic strains were pan-sensitive. Conclusions  Prophylactic antibiotics are capable of eliminating the normal vaginal inhabitants, which may increase the probability of UTI. The administration of vaginal probiotics as an alternate or multidrug therapy can restore vaginal microbiota and help prevent recurrent UTI.

The vaginal microbiome of sub-Saharan African women: revealing important gaps in the era of next-generation sequencing

Accurate characterization of the vaginal microbiome remains a fundamental goal of the Human Microbiome project (HMP). For over a decade, this goal has been made possible deploying high-throughput next generation sequencing technologies (NGS), which indeed has revolutionized medical research and enabled large-scale genomic studies. The 16S rRNA marker-gene survey is the most commonly explored approach for vaginal microbial community studies. With this approach, prior studies have elucidated substantial variations in the vaginal microbiome of women from different ethnicities. This review provides a comprehensive account of studies that have deployed this approach to describe the vaginal microbiota of African women in health and disease. On the basis of published data, the few studies reported from the African population are mainly in non-pregnant post pubertal women and calls for more detailed studies in pregnant and postnatal cohorts. We provide insight on the use of more sophisticated cutting-edge technologies in characterizing the vaginal microbiome. These technologies offer high-resolution detection of vaginal microbiome variations and community functional capabilities, which can shed light into several discrepancies observed in the vaginal microbiota of African women in an African population versus women of African descent in the diaspora.

Characterization and in vitro evaluation of a vaginal gel containing Lactobacillus crispatus for the prevention of gonorrhea

The increasing resistance of Neisseria gonorrhoeae to any current antibiotic treatment and the difficulties associated with the use of prevention means such as condom urge the need for alternative methods to prevent this sexually transmitted infection. In this work, a prevention strategy based on the use of a vaginal gel containing Lactobacilli was assessed in vitro. A Lactobacillus crispatus strain (ATCC 33197) was selected based on the published data on its ability to inhibit Neisseria gonorrhoeae. Its probiotic properties were first characterized. Then, a thermo-sensitive hydrogel containing 21.5% of poloxamer 407, 1% of sodium alginate and 9log₁₀ CFU of Lactobacillus crispatus per gel sample (5 g) was developed. The gelation temperature and the rheological characteristics of this formulation appeared suitable for a vaginal administration. Lactobacillus crispatus was viable in the gel for six months although a large amount of the bacteria was not culturable. The ability of Lactobacillus crispatus to inhibit Neisseria gonorrhoeae was still observed with the gel. Such system, thus, appeared promising for the prevention of gonorrhea.

Structural Variations of Vaginal and Endometrial Microbiota: Hints on Female Infertility

Microbiota are microorganismal communities colonizing human tissues exposed to the external environment, including the urogenital tract. The bacterial composition of the vaginal microbiota has been established and is partially related to obstetric outcome, while the uterine microbiota, considered to be a sterile environment for years, is now the focus of more extensive studies and debates. The characterization of the microbiota contained in the reproductive tract (RT) of asymptomatic and infertile women, could define a specific RT microbiota associated with implantation failure. In this pilot study, 34 women undergoing personalized hormonal stimulation were recruited and the biological samples of each patient, vaginal fluid, and endometrial biopsy, were collected immediately prior to oocyte-pick up, and sequenced. Women were subsequently divided into groups according to fertilization outcome. Analysis of the 16s rRNA V4-V5 region revealed a significant difference between vaginal and endometrial microbiota. The vaginal microbiota of pregnant women corroborated previous data, exhibiting a lactobacilli-dominant habitat compared to non-pregnant cases, while the endometrial bacterial colonization was characterized by a polymicrobial ecosystem in which lactobacilli were exclusively detected in the group that displayed unsuccessful in vitro fertilization. Overall, these preliminary results revisit our knowledge of the genitourinary microbiota, and highlight a putative relationship between vaginal/endometrial microbiota and reproductive success.

In vitro characteristics of intravaginal Lactobacilli; why is L. iners detected in abnormal vaginal microbial flora?

PURPOSE

Our purpose is to investigate the reasons why Lactobacillus iners is detected in abnormal vaginal microbial flora.

METHODS

In this study, in vitro characteristics of four type strains (L. crispatus, L. iners, L. gasseri, and L. jensenii) were examined by measuring the growth speed by OD₆₆₀, and acid resistance, with gram stain and Live/Dead stain.

RESULTS

The growth speed was L. gasseri > L. jensenii > L. crispatus > L. iners. Bacterial counts of all Lactobacilli in MRS medium began to decrease at the middle of the log-phase of the growth curve. In addition, L. iners grew to 10⁶ CFU/mL and the others grew to 10⁸ CFU/mL. L. iners was mostly Gram-negative with very short rod, while the others were mostly Gram-positive rods. L. iners was completely killed in the pH 3 medium, however, the others grew (in pH 3 medium) in 1/100 order compared with those in the pH 6 medium.

CONCLUSION

L. iners was not a typical gram-positive long rod Lactobacilli and presented weak acid-resistance. The reasons why L. iners is detected in abnormal vaginal microbial flora were presumed to be due to the unique morphologic and microbiologic characteristics.

Anticancer effect of bacteria on cervical cancer: Molecular aspects and therapeutic implications

Cervical cancer is the second common cancer and the third leading cause of cancer deaths among women in less developed countries. It has been indicated that changes in vaginal microbiome play an important role in the occurrence and development of cervical cancer. However, studies have shown that probiotics play an effective role in fighting cancer by affecting pathogenic bacteria, inducing cancer cells apoptosis, and other anticancer activities. Therefore, the purpose of the present study is reviewing the anticancer effect of cervicovaginal bacteria and their potential for cervical cancer treatment.

An exploratory pilot study evaluating the supplementation of standard antibiotic therapy with probiotic lactobacilli in south African women with bacterial vaginosis

Background

To reduce acquisition and relapse of bacterial vaginosis (BV), lactobacilli must be maintained in the vaginal microbiome. Probiotic lactobacilli may aid this purpose. We investigated whether vaginal probiotics (containing Lactobacillus rhamnosus DSM 14870 and Lactobacillus gasseri DSM 14869) would result in vaginal colonisation with lactobacilli in women with and without BV.

Methods

This prospective, partially randomised, exploratory pilot study was conducted in Soweto, South Africa. Thirty-nine sexually-active, HIV negative women were enrolled from October 2014 to May 2016 into three arms. Women who did not have BV (Group 1, n = 13) self-administered probiotic capsules vaginally once daily for 30 days, then once a week until Day 190. Women diagnosed with BV were randomized into Group 2 (n = 12) or Group 3 (n = 14) and treated with the triple oral antibiotic combination for vaginal discharge syndrome per South African guidelines (cefixime 400 mg stat, doxycycline 100 mg BD for 7 days and metronidazole 2 g stat). Immediately after antibiotic treatment, women in Group 2 self-administered probiotic capsules vaginally once daily for 30 days then vaginally once a week until Day 190. Women in Group 3 were not given lactobacilli.

Results

During the study, L. rhamnosus DSM 14870 or L. gasseri DSM 14869, were isolated in 5/13 (38.5%) women in Group 1 compared to 10/12 (83.3%) women in Group 2 (p = 0.041). The 1-month and 6-month BV cure rates were similar (P >  0.05) between Group 2 (42 and 25%) compared to Group 3 (36 and 25%). In Group 2, no correlation was observed between the frequency of isolation of the two Lactobacillus strains and the 1-month or 6-month cure rate.

Conclusions

Supplementation with vaginal probiotic capsules resulted in colonisation of the vagina by the Lactobacillus strains (L. rhamnosus DSM 14870 and L. gasseri DSM 14869) contained in the capsules. We observed low initial cure rates of BV after a stat dose of metronidazole and that the probiotic did not improve BV cure rates or alleviate recurrence which could be due to treatment failure or very limited power of the study.

Trial registration

Registered at the Pan African Clinical Trial Registry (www.pactr.org) on April 13, 2018 (retrospectively registered). Trial identification number: PACTR201804003327269.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4425-1) contains supplementary material, which is available to authorized users.

Putative Adhesion Factors in Vaginal Lactobacillus gasseri DSM 14869: Functional Characterization

Lactobacilli play an important role in the maintenance of a healthy vaginal microbiota, and some select species are widely used as probiotics. Vaginal isolates of Lactobacillus gasseri DSM 14869 and Lactobacillus rhamnosus DSM 14870 were previously selected to develop the probiotic EcoVag capsules and showed therapeutic effects in women with bacterial vaginosis (BV). However, the molecular mechanisms involved in their probiotic activity are largely unknown. In this study, we identified three cell surface molecules in L. gasseri DSM 14869 that promote adhesion to vaginal epithelial cells (VEC) by constructing dedicated knockout mutants, including exopolysaccharides (EPSs), a protein containing MucBP-like domains (N506_1778), and a putative novel adhesin (N506_1709) with rib/alpha-like domain repeats. EPS knockout mutants revealed 20-fold and 14-fold increases in adhesion to Caco-2 and HeLa cells, respectively, compared with wild type, while the adhesion to VEC was reduced 30% by the mutation, suggesting that EPSs might mediate tissue tropism for vaginal cells. A significant decrease in adhesion to Caco-2 cells, HeLa cells, and VEC was observed in the N506_1778 knockout mutant. The N506_1709 mutant showed no significant difference for the adhesion to Caco-2 and HeLa cells compared with wild type (WT); in contrast, the adhesion to VEC revealed a significant decrease (42%), suggesting that N506_1709 might mediate specific binding to stratified squamous epithelial cells, and this putative novel adhesin was annotated as Lactobacillus vaginal epithelium adhesin (LVEA). Thus, we have discovered an important role for EPSs and a novel adhesin, LVEA, in the adhesive capacity of a vaginal probiotic Lactobacillus strain.IMPORTANCE Lactobacilli are known to contribute to the maintenance of a healthy vaginal microbiota and some are selected as probiotics for the prevention or treatment of urogenital diseases, such as bacterial vaginosis. However, the molecular mechanisms for these health-promoting effects are not fully understood. Here, we functionally identified three cell surface factors of a Lactobacillus gasseri strain potentially involved in its adhesion to vaginal epithelial cells, including exopolysaccharides (EPSs) and two sortase-dependent proteins (N506_1778 and N506_1709). We could demonstrate the tissue-specific adhesion of EPSs to vaginal cells and that N506_1709 might be a novel adhesin specifically mediating bacterial binding to stratified squamous epithelial cells. The results provide important new information on the molecular mechanisms of vaginal Lactobacillus spp. adhesion.

Contrasting diversity of vaginal lactobacilli among the females of Northeast India

BACKGROUND

Lactobacilli are gatekeepers of vaginal ecosystem impeding growth of pathogenic microbes and their diversity varies across populations worldwide. The present study investigated diversity of human vaginal microbiota among females of Northeast India, who are distinct in dietary habits, lifestyle, and genomic composition from rest of India.

RESULTS

Altogether, 154 bacterial isolates were obtained from vaginal swab samples of 40 pregnant and 29 non-pregnant females. The samples were sequenced for 16 s rRNA gene and analysed for identification using a dual approach of homology search and maximum likelihood based clustering. Molecular identification based on 16S rRNA gene sequence confirmed the isolates belonging to 31 species. Lactobacilli constituted 37.7% of the bacterial isolates with 10 species and other Lactic Acid Bacteria (39.61%) represented another 10 species, some of which are opportunistic pathogens. The remaining of the communities are mostly dominated by species of Staphylococcus (14.28%) and rarely by Propionibacterium avidum (3.90%), Bacillus subtilis, Escherchia coli, Janthinobacterium lividum, and Kocuria kristinae (each 0.64%). Interestingly Lactobacillus mucosae and Enterococcus faecalis, which are globally uncommon vaginal microbes is found dominant among women of Northeast India. This tentatively reflects adaptability of particular Lactobacillus species, in distinct population, to better compete for receptors and nutrients in vaginal epithelium than other species. Further, intrageneric 16S rRNA gene exchange was observed among Enterococcus, Staphylococcus, and two species of Lactobacillus, and deep intraspecies divergence among L. mucosae, which pinpointed possibility of emergence of new strains with evolved functionality. Lactobacilli percentage decreased from young pregnant to aged non-pregnant women with maximum colonization in trimester II.

CONCLUSION

The study highlighted importance of assessment of vaginal microbiota, Lactobacillus in particular, across different population to gain more insight on female health.

Crosstalk between Vaginal Microbiome and Female Health: A review

Microbiota plays a fundamental role in the overall development and defences of human beings. The majority of indigenous microbiota exists in a mutually beneficial relationship with their hosts, while few of these are opportunistic pathogens that can lead to life-threatening diseases and chronic infections. These microbial communities constitute the primary defence against infections induced by non-indigenous invasive organisms. Female vaginal ecosystem thought to have been shaped over the years by co-evolutionary processes occurring between the particular microbial partners and the human host. Vaginal secretions contain numerous microorganisms and the host provides them nutrients for their growth and development. Disruptions in vaginal association with the microbiomes lead to the change in the vaginal environment, which enhanced the risk of acquiring diseases including sexually transmitted infections, bacterial vaginosis, fungal infections, preterm birth etc. The focus of this review is on the detailed analysis of vaginal microbiome interplay and its overall impact on female health. The mutualistic relationship between the vagina and residing microbial species has been well described. Finally, the recent advancements in the detection of microbiome interactions with the vaginal environment have been presented.

Development and validation of a new one step Multiplex-PCR assay for the detection of ten Lactobacillus species

Lactobacillus sp. are well-known colonizers of human mucosa and frequently used as probiotics. Accurate species identification is crucial both for fundamental studies and biotechnology applications; however, it has been thus far challenging. The aim of this work was to develop a one-step multiplex-PCR assay for detection of ten Lactobacillus species (L. jensenii, L. fermentum, L. acidophilus, L. crispatus, L. reuteri, L. iners, L. casei, L. gasseri, L. plantarum, L. rhamnosus) directly in complex bacterial genomic DNA. A multiplex-PCR assay was optimized based on Box-Behnken experimental design, which showed to be efficient for optimization of all crucial reaction components. Nineteen Lactobacillus strains, including six collection strains and thirteen human isolates were used in order to verify the specificity and sensitivity of the assay. In addition, a set of PCR adjuvants was introduced to remove non-specific amplifications and enhance reaction yield. Among them, Triton™ X-100, Tween^® 20, BSA, and dithiothreitol showed beneficial effects when compared with other adjuvants. The application of the developed method to samples that resulted from the mixing of DNA from the ten strains, resulted in amplicons of the expected sizes (from about 100 to 1000 bp). The detection limit was 1.25 ng/μl for all species with the exception of L. gasseri (0.31 ng/μl). In order to confirm the method applicability on human samples, ten vaginal fluids were enrolled in this study showing that the method can be successfully used on these biological materials. The proposed multiplex-PCR assay was shown to be selective, sensitive and efficient for detection of ten Lactobacillus species directly in human vaginal samples. This method provides a cost-effective and accessible methodology applicable to the detection of Lactobacillus species to different environments. At the same time, this approach represents a considerable improvement over other PCR-based approaches for identification of these species.

Comparison of MALDI-TOF MS Biotyper and 16S rDNA sequencing for the identification of Pseudomonas species isolated from fish

Effective and reliable methods of identification of Pseudomonas species are important for the characterization of microorganisms. Freshwater ecosystems are an important source of Pseudomonas species, including those pathogenic to fish and humans. The aim of the present study was to compare the identification conducted with MALDI-TOF MS Biotyper and 16S rDNA sequencing of fish-borne Pseudomonas spp. Altogether, 13 different Pseudomonas spp. were isolated from freshwater fish. Phylogenetic analysis showed a clear taxonomic placement only for 13 out of 15 Pseudomonas isolates. Accordance of identification method was found only in 6 out of 15 isolates. The human pathogenic Pseudomonas spp. were not found in our study, indicating that the fish could be considered as safe for consumption. The present study revealed a high discriminatory power of the mass spectra investigation and 16S rDNA gene sequencing technology for the identification of Pseudomonas spp. associated with freshwater fish.

In vitro evaluation of microbial adhesion to a contraceptive vaginal ring with a new polymer composition

Objective: The aim of the study was to evaluate in vitro the amount of Candida albicans and Lactobacillus acidophilus adhering to the surface of Ornibel, a contraceptive vaginal ring with a new polymer composition, in comparison with NuvaRing. Methods: Ornibel and NuvaRing were tested for adhesion of microorganisms in vitro. The vaginal rings were aseptically sectioned into 1 cm segments. Suspensions of C. albicans (1-2 × 10⁷ colony-forming units [CFU]/ml) and L. acidophilus (1-2 × 10⁸ CFU/ml) were prepared and incubated either in monoculture or as co-culture with the ring segments. After incubation, adherent C. albicans and L. acidophilus were quantified by plate counting. Results: In monoculture, the measured amount of adhesion of C. albicans on the ring surface was significantly lower with Ornibel compared with NuvaRing (p = 6.77 × 10^-5), while the adherence of L. acidophilus did not differ between the two rings. Similarly, when co-incubated with C. albicans, the number of adhering L. acidophilus microorganisms was significantly lower with Ornibel compared with NuvaRing (p = .018) . This reduction also resulted in significantly lower levels of adhering L. acidophilus in co-culture compared with L. acidophilus when incubated alone (p = .003). Conclusion: The study demonstrates that the adherence of C. albicans, as well as that of L. acidophilus when co-cultured with C. albicans, is lower with the Ornibel vaginal ring compared with NuvaRing. These in vitro findings warrant future human trials using molecular techniques to assess the vaginal microbiota composition and to establish whether Ornibel can support vaginal health.

Genome Sequence Announcement of Lactobacillus vaginalis LMG S-26419, Isolated from a Healthy Woman

The Lactobacillus vaginalis LMG S-26419 strain, also named CBA-L88 (BV2), was isolated at the AAT-Advanced Analytical Technologies laboratories from a vaginal swab obtained from a healthy woman. The total genome size is 1,806,242 bp with a G+C content of 40.6%.

Biological properties and production of bacteriocins-like-inhibitory substances by Lactobacillus sp. strains from human vagina

AIMS

The aim of this study was to characterize Lactobacillus strains for their biological properties and amensalistic activities against genital and nongenital pathogens.

METHODS AND RESULTS

For the purpose, some special characteristics (H₂ O₂ , biofilm and antimicrobial substances production) as well as safety properties of 112 lactobacilli were evaluated. All the strains had good amensalistic characteristics, in particular cell-free supernatants of 10 strains showed antibacterial activity against bacteria, as well as Candida sp. Moreover, these 10 strains were excellent biofilm producers.

CONCLUSIONS

These results provide evidence for the possible use as probiotics for vaginal co-therapy in case of dysbiosis.

SIGNIFICANCE AND IMPACT OF THE STUDY

Recently, the problem of antibiotic resistance is constantly increasing, even though resources and energy are invested in order to increase knowledge on the mechanisms of action. Bacteriocins have a rapid mechanism of action, act at extremely low concentrations, are generally sensitive to proteases and they usually have a narrow killing spectrum; these characteristics reduce the possibility of the bacterium to develop resistance. This study is focused on the feasibility of a high production of antimicrobial substances and their characterization in order to be exploited as a therapeutic alterative or in co-therapy with antibiotics in case of vaginal dysbiosis.

Vaginal Lactobacilli Induce Differentiation of Monocytic Precursors Toward Langerhans-like Cells: in Vitro Evidence

Lactobacilli have immunomodulatory mechanisms that affect the host cell immune system, leading to inhibition of HIV-1 transmission. Thus, lactobacilli as mucosal delivery vehicles for developing HIV-1 vaccines have attracted interest in recent years. Herein, we investigated the immunomodulatory effects of six strains of Lactobacillus naturally isolated from vaginal samples, including Lactobacillus crispatus (L. crispatus), L. fermentum, L. jensenii, L. gasseri, L. delbrueckii and L. johnsonii, on differentiation of monocytic precursors. L. crispatus, L. fermentum and L. delbrueckii could drive human monocytic cell line THP-1 cells to differentiate into dendritic-like cells according to the morphology. Moreover, L. crispatus increased costimulatory molecules including CD40, CD80 and CD86, and Langerhans cell specific C-type lectin receptors CD207, while L. fermentum decreased these molecules in THP-1 cells. Furthermore, L. crispatus promoted the differentiation of THP-1 cells with specific markers, phagocytic features, cytokine production ability and reduced the expression of receptors for HIV-1 entry of Langerhans cells. However, in the presence of L. fermentum, THP-1 cells did not show the above alterations. Moreover, similar effects of L. crispatus and L. fermentum were observed in CD14⁺ monocytes. These data suggested that L. crispatus facilitates the differentiation of monocytic precursors toward Langerhans-like cells in vitro. We further identified the cell wall components of Lactobacillus and found that peptidoglycans (PGNs), rather than bacteriocins, S-layer protein and lipoteichoic acid, were key contributors to the induction of CD207 expression. However, PGNs originating from Bacillus subtilis, E. coli JM109 and E. coli DH5α did not elevate CD207 expression, indicating that only PGN derived from Lactobacillus could enhance CD207 expression. Finally, the recognized receptors of L. crispatus (such as TLR2 and TLR6) and the upstream transcription factors (PU.1, TAL1, TIF1γ, and POLR2A) of CD207 were examined, and the expression of these molecules was enhanced in THP-1 cells following L. crispatus treatment. Thus, this study offers powerful evidence that vaginal lactobacilli modulate monocytic precursor differentiation into Langerhans-like cells probably via activating the TLR2/6-TFs-CD207 axis. These data provide clues for further investigation of the original occurrence, development and differentiation of Langerhans cells from monocytes.