Evaluation of the vaginal microbiome in clinical diagnosis and management of vaginal infectious diseases

Assessing vaginal microbiome through Vaginal Microecology Evaluation System as a predictor for in vitro fertilization outcomes: a retrospective study

Objective

This study aims to evaluate the effectiveness of the Vaginal Microecology Evaluation System (VMES) in assessing the dynamics of the vaginal microbiome (VM) throughout the process of in vitro fertilization and embryo transfer (IVF-ET). Furthermore, it seeks to explore the potential correlation between distinct types of VM ecology and the success rate of IVF-ET.

Methods

This study employed VMES to ascertain the composition of the VM. Data were collected from infertile women who underwent their initial IVF-ET treatment for tubal factor between January 2018 and December 2021. A retrospective analysis of pregnancy outcomes resulting from their fresh embryo transfer was conducted to determine the predictive significance of the vaginal microenvironment.

Results

We demonstrate that VMES is able to predict IVF-ET outcomes in patients diagnosed with Bacterial Vaginosis (BV). Notably, a discernible shift in the VM was observed in a decent subset of patients following Controlled Ovarian Stimulation (COS), though this phenomenon was not universal across all participants. Specifically, there was a noteworthy increase in the proportion of patients exhibiting BV and uncharacterized dysbiosis subsequent to COS. Furthermore, our investigation revealed a significant correlation between VM and both the live birth rate and early miscarriage rate. Employing a multivariable logistic regression model, we identified that VM status pre-COS, VM status post-COS, patient age, and the number of embryos transferred emerged as independent predictors of the live birth rate.

Conclusion

Our study suggests that, during IVF-ET treatment, the VMES can effectively detect changes in the VM, which are strongly correlated with the pregnancy outcome of IVF-ET procedures.

High-throughput sequencing and characterization of potentially pathogenic fungi from the vaginal mycobiome of giant panda (Ailuropoda melanoleuca) in estrus and non-estrus

Introduction

The giant panda (Ailuropoda melanoleuca) reproduction is of worldwide attention, and the vaginal microbiome is one of the most important factors affecting the reproductive rate of giant pandas. The aim of this study is to investigate the diversity of vaginal mycobiota structure, and potential pathogenic fungi in female giant pandas during estrus and non-estrus.

Methods

This study combined with high-throughput sequencing and laboratory testing to compare the diversity of the vaginal mycobiota in giant pandas during estrus and non-estrus, and to investigate the presence of potentially pathogenic fungi. Potentially pathogenic fungi were studied in mice to explore their pathogenicity.

Results and discussion

The results revealed that during estrus, the vaginal secretions of giant pandas play a crucial role in fungal colonization. Moreover, the diversity of the vaginal mycobiota is reduced and specificity is enhanced. The abundance of Trichosporon and Cutaneotrichosporon in the vaginal mycobiota of giant pandas during estrus was significantly higher than that during non-estrus periods. Apiotrichum and Cutaneotrichosporon were considered the most important genera, and they primarily originate from the environment owing to marking behavior exhibited during the estrous period of giant pandas. Trichosporon is considered a resident mycobiota of the vagina and is an important pathogen that causes infection when immune system is suppressed. Potentially pathogenic fungi were further isolated and identified from the vaginal secretions of giant pandas during estrus, and seven strains of Apiotrichum (A. brassicae), one strain of Cutaneotrichosporon (C. moniliiforme), and nine strains of Trichosporon (two strains of T. asteroides, one strain of T. inkin, one strain of T. insectorum, and five strains of T. japonicum) were identified. Pathogenicity results showed that T. asteroides was the most pathogenic strain, as it is associated with extensive connective tissue replacement and inflammatory cell infiltration in both liver and kidney tissues. The results of this study improve our understanding of the diversity of the vaginal fungi present in giant pandas and will significantly contribute to improving the reproductive health of giant pandas in the future.

Prevalence of and risk factors for chlamydia in female outpatients with genital tract infections: a nationwide multi-center, cross-sectional study in China

Introduction

Chlamydia trachomatis is the etiological agent of the commonest sexually transmitted bacterial infection. This study aimed to examine the prevalence of genital chlamydia and associated risk factors in Chinese female outpatients with genital tract infections.

Methods

A prospective, multicenter epidemiological study of genital chlamydia prevalence in 3008 patients with genital tract infections in 13 hospitals in 12 provinces of China was performed between May 2017 and November 2018. Vaginal secretion specimens were collected for the clinical diagnosis of vaginitis, whereas cervical secretion specimens were tested for Chlamydia trachomatis and Neisseria gonorrhoeae. All patients participated in a one-on-one cross-sectional questionnaire interview.

Results

Totally 2,908 participants were included. The prevalence rates of chlamydia and gonococcal infections in women with genital tract infections were 6.33% (184/2908) and 0.01% (20/2908), respectively. Multivariate analysis showed high risk factors for chlamydia were premarital sex behavior, first sexual intercourse before the age of 20 and bacterial vaginosis.

Discussion

Given that most chlamydia cases are asymptomatic and no vaccine is currently available, chlamydia prevention strategies should include behavioral interventions as well as early screening programs to identify and treat individuals with genital tract infections, especially those with the above identified risk factors.

The change of inflammatory status and vaginal flora in pregnant women with premature rupture of membranes

Introduction. Premature rupture of the membrane (PROM) can trigger significant maternal complications, even maternal and fetal morbidity or mortality.Hypothesis. Inflammatory status and vaginal flora might be utilized to predict the occurrence of PROM.Aim. To explore the association between the occurrence of PROM and vaginal flora and inflammatory status alteration.Methodology. A case-control cross-sectional study was carried out on 140 pregnant women with or without PROM. Socio-demographic characteristics, vaginal flora assessment, pregnant outcomes and Apgar score information were retrieved.Results. Pregnant women with PROM showed an increased incidence of vulvovaginal candidiasis (VVC), trichomonas vaginitis (TV) and bacterial vaginitis (BV) with dysregulated vaginal flora and diminished fetal tolerance of labour indicated by down-regulated Apgar score. The increased rate of prematurity, puerperal infection and neonatal infection could be detected in PROM patients with imbalanced vaginal flora compared with PROM patients with normal vaginal flora. ROC analysis suggested IL-6 and TNF-α yielded the best discrimination for the prediction of PROM.Conclusion. Altered vaginal and inflammatory status are associated with PROM, and IL-6 and TNF-α can predict the occurrence of PROM.

Prevalence of Mycoplasma genitalium and Chlamydia trachomatis in Chinese female with lower reproductive tract infection: a multicenter epidemiological survey

BACKGROUND

Chlamydia trachomatis and Mycoplasma infections have been regarded as severe challenges to public health worldwide because their potential risk of leading to serious reproductive complications. C. trachomatis is the most common sexually transmitted bacterial infections and the prevalence has been increasing in recent years. As a newly discovered pathogen, Mycoplasma genitalium has gradually been recognized as important sexually transmitted infection and even been called a "new chlamydia". There are no official epidemiological data of M. genitalium in China especially in women with lower reproductive tract infection. This work aims to understand the prevalence and risk factors of M. genitalium and C. trachomatis in women with lower reproductive tract infections and to provide reference for the formulation of health policy in China.

METHODS

This study was conducted in the gynecological clinics of 12 hospitals geographically located in different regions in China. Women with purulent cervical secretions or abnormal vaginal microecology were included as the research group, and those with normal vaginal microecology and cervical secretions were included as the control group. A total of 2190 participants were recruited in this project including 1357 of research group and 833 of control group. All participants were required to complete questionnaires, whose vaginal discharge were collected for vaginal microecology test and cervical discharge for detection of M. genitalium and C. trachomatis.

RESULTS

The prevalence of C. trachomatis and M. genitalium were 7.1% (96/1357) and 3.8% (51/1357), respectively in research group. The prevalence of C. trachomatis and M. genitalium varied in different regions. Infection rates of C. trachomatis and M. genitalium were higher in women with abnormal vaginal microecology (C.t P = 0.038, M.g P = 0.043), especially in women with bacterial vaginosis and mixed vaginitis, of which C. trachomatis showed statistical differences (bacterial vaginosis, P = 0.035; mixed vaginitis, P = 0.0001) and M. genitalium was close to statistical differences (bacterial vaginosis, P = 0.057; mixed vaginitis, P = 0.081). Alcoholism and abnormal vaginal microecology were positively correlated with both C. trachomatis and M. genitalium infection. Increasing age, being married and multi-parity were negatively correlated with C. trachomatis infection. There is a positive correlation between multiple sexual partners, diversed styles of sex and C. trachomatis infection.

CONCLUSIONS

Women with lower genital dysbiosis have an increased risk of C. trachomatis and M. genitalium. The overall prevalence of M. genitalium is lower than that of C. trachomatis, while they have similarities in the characteristics of infection. Although M. genitalium is not routinely screened as C. trachomatis in young women, attention should be paid to M. genitalium infection in young women with abnormal vaginal microecology or having childbearing needs.

Natural progress history of asymptomatic bacterial vaginosis in Chinese Han women and associated risk factors

OBJECTIVE

Asymptomatic bacterial vaginosis (aBV) is prevalent in the general population, while a previous study only investigated the natural history of aBV in women at high-risk. This stage study was to investigate the natural history of aBV in Chinese Han women at general risk and examine risk factors associated with different outcomes.

METHODS

Women of reproductive age with aBV were enrolled and prospectively followed up with for four months. Participants were classified into one of three outcomes: progress, self-cure or no-change. Univariate and multivariate analyses were used to determine the association between potential risk factors and outcomes.

RESULTS

A total of 3420 subjects were screened and 1014 women with aBV were enrolled. Eventually, 984 participants completed the study, with 30 patients dropped out. Among the 984 cases, 42 cases self-cured spontaneously, while 433 cases progressed and 509 cases did not change significantly. Of the 433 cases that progressed, several types of mixed infections were observed in addition to 196 symptomatic bacterial vaginosis. According to univariate analysis, frequent travel (OR, 95% CI, 2.73 [2.09 ~ 3.55]) and history of bacterial vaginosis (BV) (5.47, [4.15 ~ 7.21]) exhibited significant associations with aBV progression, while condom contraception (0.46 [0.36 ~ 0.61]) and lower Nugent score (0.49, [0.37 ~ 0.64]) demonstrated protective effects for self-cure. According to multivariate regression analysis, the risk factors for aBV progression were history of BV (6.67, [4.86 ~ 9.15]) and frequent travel (3.57, 2.59 ~ 4.92). Condom contraception (0.36, 0.26 ~ 0.49) exhibited a protective effect against aBV progression.

CONCLUSION

Without intervention, a large proportion of aBV would progress, compared to the very few patients whose aBV self-cured spontaneously. It is necessary to clinically intervene aBV patients. Condom utilization can be used as an effective method to improve the outcome of aBV.

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.

Emerging frontiers of antibiotics use and their impacts on the human gut microbiome

Antibiotics, the primary drugs used to cure bacterial diseases, are increasingly becoming ineffective due to the emergence of multiple drug resistance (MDR) leading to recurrence of previously sensitive pathogens. Human gut microbiome (GM), known to play an important role in various physiological processes, consists of pool of diverse microbes. Indiscriminate use of antibiotics during the life span of an individual may lead to development of resistant microbes e.g. Vibrio, Acinetobacter, Escherichia, Klebsiella, Clostridia, etc. in the human GM. Transmission of antibiotic resistant genes (ARGs) between pathogenic and commensal bacteria occurs more frequently in microbiome communities wherein bacteria communicate and exchange cellular constituents both among themselves and with the host. Additionally, co-factors like 'early vs. late' exposure, type of antibiotics and duration of treatment modulate the adverse effects of antibiotics on GM maturation. Furthermore, factors like mode of birth, ethnicity, malnutrition, demography, diet, lifestyle, etc., which influence GM composition, can also indirectly alter the host response to antibiotics. Currently, advanced 'omics' and culturomics approaches are revealing novel avenues to study the interplay between antibiotics and the microbiome and to identify resistant genes in these bacterial communities. Here, we discuss the recent developments that have given insights into the effects of antibiotics on the homeostatic balance of the gut microbiome and thus on human health.

Effects of vaginal microecology and immunity on the pregnancy outcome of cervical cerclage

Objective

To investigate the effects of vaginal microecology and immune status on the pregnancy outcome of cervical cerclage.

Methods

The clinical data of 125 patients with cervical incompetence who underwent transvaginal cervical cerclage in our hospital from January 2018 to January 2021 were collected, based on which the associations of vaginal microecology and related immune cytokines (IL-1β, IL-6, IL-8 and TNF-α) with the cervical cerclage outcome were explored.

Results

All of the 125 patients had singleton pregnancies, who were aged 20–43 years, with a mean of (32.34 ± 5.17) years. The surgery was successful in 104 patients (full-term delivery or survival of premature infants), while unsuccessful in 21 patients (late miscarriage or death of premature infants), revealing a success rate of 83.20%. There were 70 full-term deliveries, 34 premature deliveries (28 survived while 6 died), and 15 late miscarriages. Univariate analysis revealed statistically significant differences in the timing of surgery, gestational age of cerclage, preoperative cervical canal length, genital tract infections and preoperative invasive procedures between the successful and unsuccessful groups (P < 0.05). Insignificant differences were found in the pre-pregnancy body mass index (BMI) (P > 0.05). According to the multivariate analysis results, cerclage timing and genital tract infections were independent risk factors for postoperative pregnancy failure (P < 0.05). The pathogen detection rates in the two groups of pregnant women were analyzed, finding significantly higher incidence of bacterial vaginosis (BV) in the unsuccessful group than in the successful group (P < 0.05). Inter-group comparison revealed that the positive rates for vaginal microenvironmental factors (LE, NAG, SNA, H₂O₂ and pH) were all significantly higher in the unsuccessful group than in the successful group (P < 0.05). Besides, the immune cytokine levels in the cervicovaginal secretions were also all significantly higher in the unsuccessful group than in the successful group (P < 0.05).

Conclusion

The pregnancy outcome of patients undergoing cervical cerclage is associated with the imbalance of vaginal microecology and the levels of IL-1β, IL-6, IL-8 and TNF-α in cervicovaginal secretions.

Impact of zinc oxide, benzoic acid and probiotics on the performance and cecal microbiota of piglets

Background

Intestinal health remains a key factor in animal production because it is essential for digestion, absorption and bacterial fermentation. Feed additives have been used to attenuate the weaning stress such as Zinc Oxide (ZnO) and benzoic acid (C₇H₆O₂). The objective of this study was to evaluate the impact of of benzoic acid and probiotics (BA + P) on performance, diarrhea and cecal microbiota of piglets in the nursery phase (23 to 65 days).

Results

One hundred and sixty weaned piglets with an initial weight of 6.335 ± 0.698 kg and 23 days of age were submitted to four treatments: supplementation with 2500 ppm of Zinc oxide (ZnO), supplementation with a commercial blend of benzoic acid and probiotics (Bacillus licheniformis, Bacillus subtilis and Enterococcus faecium NCIMB 10415; Vevogut P®) (BA + P), supplementation with Zinc oxide plus benzoic acid and probiotics (ZnO + BA + P), and controls receiving only the basal diet without any supplementation. At 65 days of age, 32 piglets (n = 8 per treatment) were slaughtered for the evaluation of the cecal microbiota. Supplementation with ZnO and BA + P were associated with better feed conversion (P < 0.05) in the early stage (23 to 49 days) and with an improvement in all performance parameters over the entire experimental period. The occurrence of diarrhea was lower (P < 0.05) in the BA + P group. The 4 most abundant phyla along with unclassified bacteria represented 93% of all sequences. Firmicutes dominated the cecal microbiota of all groups, followed by Bacteroidetes. Richness represented by the observed number of genera and by the Chao index were statistically lower in ZnO and ZnO + BA + P supplemented animals compared to controls. The beta diversity analysis that compares similarities between bacterial communities demonstrated formation of two distinct clusters containing samples with and without supplementation with ZnO, confirming a strong influence of ZnO on the intestinal microbiota.

Conclusion

The use of Benzoic acid with probiotics yields similar performance results with lower impact on the gut microbiota compared to ZnO, and it should be considered as a potential alternative in swine production.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42523-021-00151-y.

Characteristics of Vaginal Microbiome in Women with Pelvic Inflammatory Disease in Korea

Human vaginal microorganisms play an important role in maintaining good health throughout the human life cycle. An imbalance in the vaginal microbiota is associated with an increased risk of pelvic inflammatory disease (PID). This study aimed to characterize and compare vaginal microbial profiles of premenopausal Korean women with and without PID. 74 Korean premenopausal female vaginal samples were obtained; 33 were from healthy women (a control group) and 41 from PID patients. Vaginal fluid samples were collected from the vaginal wall and posterior cervix and then analyzed by 16S ribosomal ribonucleic acid (rRNA) gene-based amplicon sequencing. Results showed a significant difference between the vaginal microbial communities of the two groups (Jensen-Shannon, p = 0.014; Bray-Curtis, p = 0.009; Generalized UniFrac, p = 0.007; UniFrac, p = 0.008). Lactobacillus accounted for the highest percentage (61.0%) of the control group but was significantly decreased (34.9%) in PID patients; this was the most significant difference among all bacterial communities (p = 0.028, LDA effect size = 5.129). In addition, in the PID patient group, species diversity significantly increased (Simpson, p = 0.07) as the proportion of various pathogens increased evenly, resulting in a polymicrobial infection. Similarly, lactate, which constituted the highest percentage of the organic acids in the control group, was significantly decreased in the PID patient group (p = 0.04). The present study's findings will help understand PID from the microbiome perspective and are expected to contribute to the development of more efficient PID diagnosis and treatment modalities.

Highlights in poloxamer-based drug delivery systems as strategy at local application for vaginal infections

Infectious diseases related to the vagina include diseases caused by the imbalance of the vaginal flora and by sexually transmitted infections. Some of these present themselves as a public health problem due to the lack of efficient treatment that leads to their complete cure, and others due to the growing resistance to drugs used in therapy. In this sense, new treatment strategies are desirable, with vaginal administration rout being a great choice since can bypass first-pass metabolism and decrease drug interactions and adverse effects. However, it is worth highlighting limitations related to patient's discomfort at application time. Thereby, the use of poloxamer-based drug delivery systems is desirable due its stimuli-sensitive characteristic. Therefore, the present review reports a brief overview of poloxamer properties, biological behavior and advances in poloxamer applications in controlled drug release systems for infectious diseases related to the vagina treatment and prevention.

Analysis of the vaginal microbiome of giant pandas using metagenomics sequencing

In this study, a total of 14 vaginal samples (GPV1‐14) from giant pandas were analyzed. These vaginal samples were divided into two groups as per the region and age of giant pandas. All the vaginal samples were analyzed using metagenomic sequencing. As per the outcomes of metagenomic analysis, Proteobacteria (39.04%), Firmicutes (5.27%), Actinobacteria (2.94%), and Basidiomycota (2.77%) were found to be the dominant phyla in the microbiome of the vaginal samples. At the genus level, Pseudomonas (21.90%) was found to be the most dominant genus, followed by Streptococcus (3.47%), Psychrobacter (1.89%), and Proteus (1.38%). Metastats analysis of the microbial species in the vaginal samples of giant pandas from Wolong Nature Reserve, Dujiangyan and Ningbo Youngor Zoo, and Ya'an Bifengxia Nature Reserve was found to be significantly different (p < 0.05). Age groups, that is, AGE1 (5‐10 years old) and AGE2 (11‐16 years old), also demonstrated significantly different inter‐group microbial species (p < 0.05). For the first time, Chlamydia and Neisseria gonorrhoeae were detected in giant pandas’ reproductive tract. GPV3 vaginal sample (2.63%) showed highest Chlamydia content followed by GPV14 (0.91%), and GPV7 (0.62%). GPV5 vaginal sample (7.17%) showed the highest Neisseria gonorrhoeae content, followed by GPV14 (7.02%), and GPV8 (6.50%). Furthermore, we employed eggNOG, CAZy, KEGG, and NCBI databases to investigate the functional significance of giant panda's vaginal microbial community. The outcomes indicated that giant panda's vaginal microbes were involved in biological processes. The data from this study will help in improving the reproductive health of giant pandas.

Characteristics of aerobic vaginitis among women in Xi'an district: a hospital-based study

BACKGROUND

Aerobic vaginitis (AV) is a reproductive tract infection that affects health of women. The objective of this study was to analyze the characteristics of simple and mixed AV patients in Xi'an district and provide reference data for the clinical treatment of AV.

METHODS

Patients were recruited from the outpatient Department of Obstetrics and Gynecology in the First Affiliated Hospital of Xi'an Jiaotong University from September 2014 to April 2019 in strict accordance with inclusion and exclusion criteria. The study principally examined the vaginal ecosystem, age distribution, levels of functional enzymes, and changes in pH levels in these women. Differences within groups were analyzed.

RESULTS

A total of 284 AV patients were enrolled to investigate the distribution of simple and mixed AV infection. AV infection was found to be mainly simple infection. Simple AV patients were generally aged 50-60 years, while mixed AV patients were mostly aged 30-40 years. In the present study, the density of vaginal bacteria (OR = 13.294, 95% CI = 5.869-30.115, P < 0.01), the type of predominant bacteria (OR = 3.962, 95% CI = 1.785-7.984, P < 0.01) and positive expression of coagulase (OR = 3.789, 95% CI = 1.798-7.984, P < 0.01) were considered risk factors for mixed AV infection.

CONCLUSIONS

The epidemiology of simple and mixed AV infection were found to be different, with density of vaginal bacteria (I or IV), species that are predominant and levels of coagulase being risk factors for mixed AV infection.