The dynamic changes of vaginal microecosystem in patients with recurrent vulvovaginal candidiasis: a retrospective study of 800 patients

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.

Vaginal micro-environment disorder promotes malignant prognosis of low-grade cervical intraepithelial neoplasia: a prospective community cohort study in Shanxi Province, China

PURPOSE

Emerging evidence suggests that vaginal micro-environment disorder is closely related to the development of cervical lesions. Low-grade cervical intraepithelial neoplasia (CIN1), as an early stage of cervical lesions, exhibits a high risk of progressing to high-grade lesions or even cervical cancer. However, the effect of vaginal micro-environment on the malignant prognosis of CIN1 remains uncertain.

METHODS

A total of 504 patients diagnosed with CIN1 by pathology, who were from the population-based cohorts established in Shanxi Province, China, were enrolled and followed up for 2 years. Micro-environmental factors such as vaginal pH, cleanliness, hydrogen peroxide (H2O2), β-glucuronidase (GUSB), leucocyte esterase (LE), and sialidase (SNA) were detected to evaluate their effect on the malignant prognosis of CIN1.

RESULTS

Abnormal vaginal pH (HR = 1.472, 95%CI 1.071-2.022), cleanliness (HR = 1.446, 95%CI 1.067-1.960), H2O2 (HR = 1.525, 95%CI 1.155-2.013), GUSB (HR = 1.739, 95%CI 1.235-2.448), LE (HR = 1.434, 95%CI 1.038-1.981), and SNA (HR = 1.411, 95%CI 1.065-1.870) could promote a higher incidence of CIN1 malignant prognosis, and the combined effects of these micro-environmental factors resulted in a nearly twofold increased risk (HR = 2.492, 95%CI 1.773-3.504) compared to any single factor alone, especially under the high-risk human papillomavirus (HR-HPV) infection. Notably, the cumulative incidence of malignant prognosis for CIN1 gradually increased during the early follow-up period, reaching its peak at approximately 8 months, and then stabilizing.

CONCLUSION

Vaginal micro-environment disorder could promote CIN1 malignant prognosis, particularly in HR-HPV-infected women. Taking micro-environmental factors as the breakthrough, our study provides a feasible vision for preventing early stage cervical lesions.

Characterization of genital chlamydia trachomatis infection among women attending infertility and gynecology clinics in Hunan, China

BACKGROUND

Genital infection with Chlamydia trachomatis (C. trachomatis) is a major public health issue worldwide. It can lead to cervicitis, urethritis, and infertility. This study was conducted to determine the characteristics of genital C. trachomatis infection among women attending to the infertility and gynecology clinics.

METHODS

Endocervical swabs were collected from 8,221 women for C. trachomatis nucleotide screening and genotyping, while serum samples were collected for C. trachomatis pgp3 antibody determination using luciferase immunosorbent assays.

RESULTS

High C. trachomatis DNA prevalence (3.76%) and seroprevalence (47.46%) rates were found, with genotype E (27.5%) being the most prevalent. C. trachomatis omp1 sense mutation was associated with cervical intraepithelial neoplasia (CIN) (odds ratio [OR] = 6.033, 95% confidence interval [CI] = 1.219-39.185, p = 0.045). No significant differences in C. trachomatis seroprevalence rates were observed between women with detectable C. trachomatis DNA in the infertility and routine physical examination groups (86.67% vs. 95%, p > 0.05); however, among women with negative C. trachomatis DNA, the former group had a markedly higher seroprevalence than the latter group (56.74% vs. 20.17%, p < 0.001). C. trachomatis DNA, but not pgp3 antibody, was significantly associated with CIN (OR = 4.087, 95% CI = 2.284-7.315, p < 0.001).

CONCLUSION

Our results revealed a high prevalence, particularly seroprevalence, of C. trachomatis among women with infertility. Furthermore, we found an association between C. trachomatis omp1 sense mutations and CIN. Therefore, C. trachomatis serves as a risk factor for CIN.

Identification and characterization of mixed infections of Chlamydia trachomatis via high-throughput sequencing

Precise genotyping is necessary to understand epidemiology and clinical manifestations of Chlamydia trachomatis infection with different genotypes. Next-generation high-throughput sequencing (NGHTS) has opened new frontiers in microbial genotyping, but has been clinically characterized in only a few settings. This study aimed to determine C. trachomatis genotypes in particular mixed-genotype infections and their association with clinical manifestations and to characterize the sensitivity and accuracy of NGHTS. Cervical specimens were collected from 8,087 subjects from physical examination center (PEC), assisted reproductive technology center (ART) and gynecology clinics (GC) of Chenzhou Hospital of China. The overall prevalence of C. trachomatis was 3.8% (311/8087) whereas a prevalence of 2.8, 3.7 and 4.8% was found in PEC, ART and GC, respectively. The most frequent three C. trachomatis genotypes were E (27.4%, 83/303), F (21.5%, 65/303) and J (18.2%, 55/303). Moreover, NGHTS identified 20 (6.6%, 20/303) mixed-genotype infections of C. trachomatis. Genotype G was more often observed in the subjects with pelvic inflammatory disease than genotype E (adjusted OR = 3.61, 95%CI, 1.02–12.8, p = 0.046). Mixed-genotype infection was associated with severe vaginal cleanliness (degree IV) with an adjusted OR of 5.17 (95%CI 1.03–25.9, p = 0.046) whereas mixed-genotype infection with large proportion of minor genotypes was associated with cervical squamous intraepithelial lesion (SIL) with an adjusted OR of 5.51 (95%CI 1.17–26.01, p = 0.031). Our results indicated that NGHTS is a feasible tool to identity C. trachomatis mixed-genotype infections, which may be associated with worse vaginal cleanliness and cervical SIL.

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.

Does probiotics work for bacterial vaginosis and vulvovaginal candidiasis

The different Lactobacillus strains of probiotics have been applied to the treatment and prevention of bacterial vaginosis and vulvovaginal candidiasis. The experimental data demonstrated that it works well via reducing the number of harmful bacteria, maintaining the acidic microenvironment, inhibiting the immune response, and so on, to restore the vaginal microecology. However, the clinical data indicated that it is not sufficient to support the use of probiotics in the intervention of vulvovaginal candidiasis rather than bacterial vaginosis. Hunting for novel probiotic strains and uncovering the precise mechanism of probiotics, especially with the new concept gut-vagina axis, to maintain the homeostasis of vaginal microbiota should be a great challenge in the future.

The association between the vaginal microenvironment and fecundability: a register-based cohort study among Chinese women

OBJECTIVE

To evaluate the association between the vaginal microenvironment and fecundability among women.

DESIGN

Register-based nationwide cohort study.

SETTING

Chinese National Free Pre-conception Check-up Project from 2015 to 2018.

POPULATION

Our study included a total of 3 388 554 eligible women who were attempting to become pregnant.

METHOD

We assessed the vaginal microenvironment at baseline by considering four indices: vaginal pH, clue cell examination, whiff test and vaginal cleanliness grading. If any of these indicators was abnormal, the vaginal microenvironment was defined as poor. Propensity score matching was used to control for potential confounders and reduce bias. Logistic models were used to estimate the fecundability odds ratios (FORs) after adjustment for covariates.

MAIN OUTCOME MEASURES

Achievement of a pregnancy within 1 year.

RESULTS

Of the total study population, 379 718 women (11.2%) had a poor vaginal microenvironment and their pregnancy rate after 1 year was significantly lower than the group with a normal microenvironment (71.8% versus 76.1%, P < 0.001). After adjusting for potential confounders, the women with a poor vaginal microenvironment were associated with a 9% reduction in fecundability compared with the normal microenvironment group (FOR 0.91, 95% CI 0.90-0.92). The adverse effects of a poor vaginal microenvironment were stronger among multipara (FOR 0.89, 95% CI 0.87-0.90) or women with irregular menstruation (FOR 0.86, 95% CI 0.84-0.89).

CONCLUSION

There was a negative association between a poor vaginal microenvironment and the fecundability of women. These findings highlight the significance of assessing the vaginal microenvironment during pre-pregnancy health examinations.

TWEETABLE ABSTRACT

Women with a poor vaginal microenvironment were associated with a reduction in fecundability.

Association of the vaginal microbiota with pregnancy outcomes in Chinese women after cervical cerclage

RESEARCH QUESTION

The study aimed to investigate the relationship between risk factors associated with vaginal microbiota and outcomes of cervical cerclage.

DESIGN

A retrospective cohort study of singleton pregnancies with cervical cerclage was conducted. Before cerclage, participants underwent a vaginal microbiota assay, including morphological examination and functional vaginal microecological analysis using a vaginitis multi-test kit. The chi-squared test and logistic and linear regression analyses were performed to evaluate the associations of various risk factors with maternal and neonatal outcomes.

RESULTS

Eighty-five participants were included. The mean interval between cerclage and delivery was 69.4 ± 36.7 days, and 12 (14.1%) of newborns died. A higher grade of vaginal cleanliness, a higher pH, a lower abundance of Lactobacillus spp., a higher sialidase-positive percentage, a higher positive percentage of clue cells, a higher lactobacillary grade, a higher Nugent score and a higher rate of microecological dysbiosis were significantly associated with a poor neonatal outcome and shorter cerclage to delivery intervals (P < 0.001-0.041). Furthermore, sialidase positivity was associated with the highest risk of cervical cerclage failure (odds ratio [OR] 10.469; 95% confidence interval [CI] 1.096-36.087), followed by the presence of bulging membranes (OR 6.400; 95% CI 0.428-15.641) and vaginal microbiota dysbiosis (OR 6.038; 95% CI 0.173-17.072).

CONCLUSIONS

An absence of Lactobacillus spp. and some functional factors of vaginal microbiota are potential risk factors that predict subsequent cerclage failure. These findings indicate the potential clinical utility of these factors to predict cervical cerclage failure for managing patient expectations and providing improved postoperative surveillance.

The oncogenic roles of bacterial infections in development of cancer

Initiation of cancer is interconnected with different factors like infections. It has been estimated that infections, particularly viruses, participate in about 20% of all cancers. Bacteria as the most common infectious agents are also reported to be emerging players in the establishment of malignant cells. Microbial infections are able to modulate host cell transformation for promoting malignant features through the production of carcinogenic metabolites participating in inflammation responses, disruption of cell metabolism, and integrity and also genomic or epigenetic manipulations. It seems that the best example of the role of bacteria in cancer promotion is Helicobacter pylori infection, which is related to gastric cancer. World Health Organization (WHO) describes bacterium as class I carcinogens. Several bacterial infections have been reported in association with prevalent cancers. In this review, we will summarize the role of known bacterial infections in the initiation of the main common cancers, which show high mortality in the world. Examining the microbiomes in cancer patients is important and necessary to better understand the pathogenesis of this disease and also to plan therapeutic interventions.

Lactobacillus iners Is Associated with Vaginal Dysbiosis in Healthy Pregnant Women: A Preliminary Study

Vaginal dysbiosis has been identified to be associated with adverse pregnancy outcomes, such as preterm delivery and premature rupture of membranes. However, the overall structure and composition of vaginal microbiota in different trimesters of the pregnant women has not been fully elucidated. In this study, the physiological changes of the vaginal microbiota in healthy pregnant women were investigated. A total of 83 healthy pregnant participants were enrolled, who are in the first, second, or third pregnancy trimester. Quantitative real-time PCR was used to explore the abundant bacteria in the vaginal microbiota. No significant difference in the abundance of Gardnerella, Atopobium, Megasphaera, Eggerthella, Leptotrichia/Sneathia, or Prevotella was found among different trimesters, except Lactobacillus. Compared with the first pregnancy trimester, the abundance of L. iners decreased in the second and third trimester while the abundance of L. crispatus was increased in the second trimester. Moreover, we also found that vaginal cleanliness is correlated with the present of Lactobacillus, Atopobium, and Prevotella and leukocyte esterase is associated with Lactobacillus, Atopobium, Gardnerella, Eggerthella, Leptotrichia/Sneathia, and Prevotella. For those whose vaginal cleanliness raised or leukocyte esterase became positive, the richness of L. iners increased, while that of L. crispatus decreased significantly. Our present data indicated that the altered vaginal microbiota, mainly Lactobacillus, could be observed among different trimesters of pregnancy and L. iners could be considered as a potential bacterial marker for evaluating vaginal cleanliness and leukocyte esterase.

Role of Lactobacillus in cervical cancer

Cervical cancer is a common malignant cancer among women worldwide. Changes in the vaginal microecological environment lead to multiple gynecological diseases, including cervical cancer. Recent research has shown that Lactobacillus may play an important role in the occurrence and development of cervical cancer. This review explores the role of Lactobacillus in cervical cancer. A total of 29 articles were included after identification and screening. The pertinent literature on Lactobacillus in cervical cancer from two perspectives, including clinical studies and experimental studies, was analyzed. An association network for the mechanism by which Lactobacillus induces cervical cancer was constructed. In addition, we provide direction and insight for further research on the role of Lactobacillus in cervical cancer.

The effect of a vaginal suppository formulation of dill (Anethum graveolens) in comparison to clotrimazole vaginal tablet on the treatment of vulvovaginal candidiasis

The goal of this study was to compare the effect of Anethum graveolens (dill) vaginal suppositories and 100 mg clotrimazole vaginal tablets on vulvovaginal Candidiasis. This study was a single centre, single-blind, randomised, placebo-controlled trial, in which 60 women with microbiology-confirmed vulvovaginal candidiasis were randomly assigned to dill and clotrimazole groups. At the end of the study, the estimated prevalence of leucorrhoea, burning, and itching was 23%, 23% and 20% in dill users, respectively. This figure was 20%, 10% and 16.7% for the clotrimazole group, respectively. The difference between the two groups was not significant. 13% of suppository patients, compared with 10% of clotrimazole-treatment patients, had a positive culture, which was not significant (p = .68). According to findings, 2% dill vaginal suppositories were as effective as clotrimazole vaginal tablets in reducing both clinical and microbiological symptoms of Candidiasis. Studies with larger sample sizes are required to confirm current findings. Impact statement What is already known on the subject? Based on results from in vivo and in vitro animal studies, dill (Anethum graveolens) has anti-candida activity. What do the results of this study add? It appears that 2% dill vaginal suppositories were as effective as 100 mg clotrimazole vaginal tablets in reducing both the clinical and microbiological symptoms. What are the implications of these findings for clinical practice and further research? Obstetricians and gynaecologists can offer dill as a useful alternative to chemical drugs, especially in women who are often interested in herbal medicine, or in women who are resistant or are not allowed to use antifungal drugs.

Recurrent vulvovaginal candidiasis

PURPOSE

Recurrent vulvovaginal candidiasis (RVVC), multiple episodes of vulvovaginal candidiasis (VVC; vaginal yeast infection) within a 12-month period, adversely affects quality of life, mental health, and sexual activity. Diagnosis is not straightforward, as VVC is defined by the combination of often nonspecific vaginal symptoms and the presence of yeast-which is a common vaginal commensal. Estimating the incidence and prevalence is challenging: most VVC is diagnosed and treated empirically, the availability for purchase of effective therapies over the counter enables self-diagnosis and treatment, and the duration of the relatively benign VVC symptoms is short, introducing errors into any estimates relying on medical records or patient recall.

METHODS

We evaluate current estimates of VVC and RVVC and provide new prevalence estimates using data from a 2011 seven-country (n = 7345) internet panel survey on VVC conducted by Ipsos Health (https://www.ipsos.com/en). We also evaluate information on VVC-associated visits using the National Ambulatory Medical Care Survey.

RESULTS

The estimated probability of VVC by age 50 varied widely by country (from 23% to 49%, mean 39%), as did the estimated probability of RVVC after VVC (from 14% to 28%, mean 23%).

CONCLUSIONS

However estimated, the probability of RVVC was high suggesting RVVC is a common condition.

Epidemiological investigation of the relationship between common lower genital tract infections and high-risk human papillomavirus infections among women in Beijing, China

BACKGROUND

The incidence of lower genital tract infections in China has been increasing in recent years. The link between high-risk human papillomavirus (HR-HPV) and other sexually transmitted diseases (STDs) remains unclear.

METHODS

From March to October 2014, gynecological examinations and questionnaires were conducted on 1218 married women. Cervical secretions and vaginal swab specimens were tested for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Ureaplasma urealyticum (UU), yeast, clue cells and HR-HPV.

RESULTS

Laboratory results were available for 1195 of 1218 married women. HR-HPV was detected in 7.0% of participants. Forty-seven percent of women had lower genital tract infections (LGTIs). UU was the most common infection (35.5%), followed by bacterial vaginosis (BV) (10.5%), yeast infection (3.7%), CT (2.2%), and Trichomonas vaginalis (1.7%). BV was associated with an increased risk of HR- HPV (P < 0.0001; odds ratio, 3.0 [95% CI, 1.7-5.4]). There was a strong correlation between abnormal cervical cytology and HR-HPV infection (P < 0.0001).

CONCLUSIONS

The prevalence of LGTIs in Beijing is at a high level. It is clinically important to screen for the simultaneous presence of pathogens that cause co-infections with HR-HPV.

[Longitudinal analysis of vaginal microbiota in women with recurrent vulvovaginal candidiasis]

OBJECTIVE

To investigate the vaginal flora in patients with recurrent vulvovaginal candidiasis (RVVC).

METHODS

Vaginal swabs were collected at different time points from 6 RVVC patients and 5 healthy women of child-bearing age. The dynamic changes, microbiota composition, alpha diversity and beta diversity in the two groups were assessed by analyzing the 16S rRNA V4 hypervariable region amplified from the total genomic DNA from the swabs.

RESULTS

Lactobacillus was the predominant species in healthy women with similar proportions of L.iners and L.crispatus; small proportions of Gardnerella, Prevotella and other genus were also detected. In some healthy women, the vaginal flora showed a high relative abundance of anaerobic bacteria such as Gardnerella, Prevotella, Atopobium, Sneathia. Compared with the healthy women, patients with RVVC showed a significantly reduced diversity of vaginal flora, where L.iners was the predominant species and the content of L.crispatus decreased significantly. In healthy women, the vaginal flora fluctuated with the menstrual cycle, and the fluctuation was the most prominent during menstruation; the dominant species either alternated regularly or maintain an absolute superiority in the menstrual cycle. The vaginal flora showed attenuated fluctuation in women with RVVC, were highly conserved within the menstrual cycle, and maintained a similar composition in the episodes and intermittent periods.

CONCLUSION

The vaginal flora of RVVC patients do not undergo regular variations with the menstrual cycle and shows a similar composition between the episodes and intermittent periods. Promoting the production of L.iners or inhibiting the colonization of L.crispatus to restore the composition of the vaginal flora may help in the treatment of RVVC.