Self-collected vaginal swabs for the quantitative real-time polymerase chain reaction assay of Atopobium vaginae and Gardnerella vaginalis and the diagnosis of bacterial vaginosis

Effectiveness and Costs of Molecular Screening and Treatment for Bacterial Vaginosis to Prevent Preterm Birth: The AuTop Randomized Clinical Trial

Importance

Bacterial vaginosis (BV) is a well-known risk factor for preterm birth. Molecular diagnosis of BV is now available. Its impact in the screening and treatment of BV during pregnancy on preterm births has not been evaluated to date.

Objective

To evaluate the clinical and economic effects of point-of-care quantitative real-time polymerase chain reaction screen and treat for BV in low-risk pregnant women on preterm birth.

Design, Setting, and Participants

The AuTop trial was a prospective, multicenter, parallel, individually randomized, open-label, superiority trial conducted in 19 French perinatal centers between March 9, 2015, and December 18, 2017. Low-risk pregnant women before 20 weeks' gestation without previous preterm births or late miscarriages were enrolled. Data were analyzed from October 2021 to November 2022.

Interventions

Participants were randomized 1:1 to BV screen and treat using self-collected vaginal swabs (n = 3333) or usual care (n = 3338). BV was defined as Atopobium vaginae (Fannyhessea vaginae) load of 108 copies/mL or greater and/or Gardnerella vaginalis load of 109 copies/mL or greater, using point-of-care quantitative real-time polymerase chain reaction assays. The control group received usual care with no screening of BV.

Main Outcomes and Measures

Overall rate of preterm birth before 37 weeks' gestation and total costs were calculated in both groups. Secondary outcomes were related to treatment success as well as maternal and neonate health. Post hoc subgroup analyses were conducted.

Results

Among 6671 randomized women (mean [SD] age, 30.6 [5.0] years; mean [SD] gestational age, 15.5 [2.8] weeks), the intention-to-treat analysis of the primary clinical and economic outcomes showed no evidence of a reduction in the rate of preterm birth and total costs with the screen and treat strategy compared with usual care. The rate of preterm birth was 3.8% (127 of 3333) in the screen and treat group and 4.6% (153 of 3338) in the control group (risk ratio [RR], 0.83; 95% CI, 0.66-1.05; P = .12). On average, the cost of the intervention was €203.6 (US $218.0) per participant, and the total average cost was €3344.3 (US $3580.5) in the screen and treat group vs €3272.9 (US $3504.1) in the control group, with no significant differences being observed. In the subgroup of nulliparous women (n = 3438), screen and treat was significantly more effective than usual care (RR, 0.62; 95% CI, 0.45-0.84; P for interaction = .003), whereas no statistical difference was found in multiparous (RR, 1.30; 95% CI, 0.90-1.87).

Conclusion and Relevance

In this clinical trial of pregnant women at low risk of preterm birth, molecular screening and treatment for BV based on A vaginae (F vaginae) and/or G vaginalis quantification did not significantly reduce preterm birth rates. Post hoc analysis suggests a benefit of screen and treat in low-risk nulliparous women, warranting further evaluation in this group.

Trial Registration

ClinicalTrials.gov Identifier: NCT02288832.

Bacterial Vaginosis: What Do We Currently Know?

The vaginal microbiome is a well-defined compartment of the human microbiome. It has unique conditions, characterized by the dominance of one bacterial species, the Lactobacilli. This microbiota manifests itself by a low degree of diversity and by a strong dynamic of change in its composition under the influence of various exogenous and endogenous factors. The increase in diversity may paradoxically be associated with dysbiosis, such as bacterial vaginosis (BV). BV is the result of a disturbance in the vaginal ecosystem; i.e., a sudden replacement of Lactobacilli by anaerobic bacteria such as Gardnerella vaginalis, Atopobium vaginae, Ureaplasma urealyticum, Mycoplasma hominis, and others. It is the most common cause of vaginal discharge in women of childbearing age, approximately 30% of all causes. The etiology of this dysbiosis remains unknown, but its health consequences are significant, including obstetrical complications, increased risk of sexually transmitted infections and urogenital infections. Its diagnosis is based on Amsel’s clinical criteria and/or a gram stain based on the Nugent score. While both of these methods have been widely applied worldwide for approximately three decades, Nugent score are still considered the “gold standard” of BV diagnostic tools. Given the limitations of these tools, methods based on molecular biology have been developed as alternative rational strategies for the diagnosis of BV. The treatment of BV aims at restoring the balance of the vaginal flora to stop the proliferation of harmful microorganisms. Prescription of antibiotics such as metronidazole, clindamycin, etc. is recommended. Faced with the considerable uncertainty about the cause of BV, the high rate of recurrence, the unacceptable treatment options, and clinical management which is often insensitive and inconsistent, research on this topic is intensifying. Knowledge of its composition and its associated variations represents the key element in improving the therapeutic management of patients with the most suitable treatments possible.

Probiotics in addition to metronidazole for treatment Trichomonas vaginalis in the presence of BV: a randomized, placebo-controlled, double-blind study

The purpose was to evaluate whether probiotics can increase the effectiveness of antimicrobial therapy. Ninety women with Trichomonas vaginalis (TV) in the presence BV were included in the study of regimens for therapy combination with metronidazole and vaginal probiotics. For 7 days, the probiotics group patients received metronidazole at 500 mg twice a day and 1 capsule of probiotic Gynophilus® vaginally twice a day; the placebo group patients in addition to metronidazole received a placebo instead of a probiotic. For the next 7 days, patients in both groups in order restore normal microflora were given the probiotics vaginally. Before the treatment, on the 4th, 8th, and 15th day of therapy complaints, pH and redox potential of the vaginal fluid were recorded, TV detection culturally, microflora of the vagina with the qPCR-RT and microscopically. Adding probiotics to traditional therapy of TV in the presence of BV increased the likelihood of cure from TV (88.6 and 42.9% in the probiotic and placebo groups, respectively) and from BV (63.6 and 11.9%, respectively). We have found that the addition of probiotics to antimicrobial therapy causes the decrease in the inflammatory response and significant changes in the vagina's physicochemical parameters (decreased of the pH values, increased of the redox potential) already on the fourth day of the therapy. The changes in the metronidazole's antimicrobial action implementation when a probiotic is added are the reason of increasing the TV therapy's effectiveness in the BV presence.

Development of a nomogram for individual preterm birth risk evaluation

OBJECTIVE

This study aimed to develop a new tool for personalised preterm birth risk evaluation in high-risk population.

STUDY DESIGN

813 high-risk asymptomatic pregnant women included in a French multicentric prospective study were analysed. Clinical and paraclinical variables, including screening for bacterial vaginosis with molecular biology, cervical length, have been used to create the nomogram, based on the logistic regression model. The validity was checked by bootstrap. A downloadable calculator was build.

RESULTS

Nine risk factors were included in this model: history of late miscarriage and/or preterm delivery, active smoking, ultrasound cervical length, term of pregnancy at screening, bacterial vaginosis, premature rupture of membranes, daily travel more than 30min. Discrimination and calibration of the nomogram revealed good predictive abilities. The area under the receiver operating characteristic curve was 0.77 (95% CI; 0.72-0.81). The mean absolute error was 0.018, which showed proper calibration. The optimal risk threshold was 23.2% with a sensitivity of 74%, a specificity of 72.7% and a predictive negative value of 90.6%.

CONCLUSION

The nomogram can help to better define individual preterm birth risk in high-risk pregnancies.

Vaginal self-sampling as a diagnosis tool in low-income countries and potential applications for exploring the infectious causes of miscarriage

Gynecological health is a challenge in low-income countries. Personal opposition to perineal examination has been overcome by the use of vaginal self-sampling. Here, we review the use of this procedure notably in low-income countries and the main infectious causes of miscarriage. Vaginal self-sampling was mainly used for human papillomavirus detection but also to detect microorganisms causing sexually transmitted infections or bacterial vaginosis. 58 studies have been performed in low-resource countries, mainly studies performed to detect human papillomavirus in urban and peri-urban areas and demonstrating excellent acceptability. Several infectious causes of miscarriage could be tested using self-vaginal samples. In the future, such strategies coupled with a rapid-identification point-of-care method could allow the development of screening and treatment programs in rural areas in low-resource countries.

The Point-of-Care Laboratory in Clinical Microbiology

Point-of-care (POC) laboratories that deliver rapid diagnoses of infectious diseases were invented to balance the centralization of core laboratories. POC laboratories operate 24 h a day and 7 days a week to provide diagnoses within 2 h, largely based on immunochromatography and real-time PCR tests. In our experience, these tests are conveniently combined into syndrome-based kits that facilitate sampling, including self-sampling and test operations, as POC laboratories can be operated by trained operators who are not necessarily biologists. POC laboratories are a way of easily providing clinical microbiology testing for populations distant from laboratories in developing and developed countries and on ships. Modern Internet connections enable support from core laboratories. The cost-effectiveness of POC laboratories has been established for the rapid diagnosis of tuberculosis and sexually transmitted infections in both developed and developing countries.

First Trimester Levels of BV-Associated Bacteria and Risk of Miscarriage Among Women Early in Pregnancy

OBJECTIVES

Prior studies have examined the role of bacterial vaginosis (BV) and increased risk of miscarriage; however the risk has been modest and many BV positive pregnant women deliver at term. BV is microbiologically heterogeneous, and thus the identification of specific BV-associated bacteria associated with miscarriage is warranted.

METHODS

We measured the presence and level of seven BV-associated bacteria prior to 14 weeks gestation among urban pregnant women seeking routine prenatal care at five urban obstetric practices at Temple University Hospital in Philadelphia PA from July 2008 through September 2011. 418 Pregnant women were included in this assessment and 74 experienced a miscarriage.

RESULTS

Mean log concentration of BVAB3 was significantly higher among women experiencing a miscarriage (4.27 vs. 3.71, p value = 0.012). Younger women with high levels of BVAB3 had the greatest risk of miscarriage. In addition, we found a significant decreased risk of miscarriage among women with higher log concentrations of Leptotrichia/Sneathia species or Megasphaera phylotype 1-like species early in pregnancy.

CONCLUSIONS FOR PRACTICE

The identification of selected vaginal bacteria associated with an increased risk of miscarriage could support screening programs early in pregnancy and promote early therapies to reduce early pregnancy loss.

Intricacies of assessing the human microbiome in epidemiologic studies

PURPOSE

In the past decade, remarkable relationships have been documented between dysbiosis of the human microbiota and adverse health outcomes. This review seeks to highlight some of the challenges and pitfalls that may be encountered during all stages of microbiota research, from study design and sample collection, to nucleic acid extraction and sequencing, and bioinformatic and statistical analysis.

METHODS

Literature focused on human microbiota research was reviewed and summarized.

RESULTS

Although most studies have focused on surveying the composition of the microbiota, fewer have explored the causal roles of these bacteria, archaea, viruses, and fungi in affecting disease states. Microbiome research is in its relatively early years and many aspects remain challenging, including the complexity and personalized aspects of microbial communities, the influence of exogenous and often confounding factors, the need to apply fundamental principles of ecology and epidemiology, the necessity for new software tools, and the rapidly evolving genomic, technological, and analytical landscapes.

CONCLUSIONS

Incorporating human microbiome research in large epidemiologic studies will soon help us unravel the intricate relationships that we have with our microbial partners and provide interventional opportunities to improve human health.

Screen-and-treat program by point-of-care of Atopobium vaginae and Gardnerella vaginalis in preventing preterm birth (AuTop trial): study protocol for a randomized controlled trial

BACKGROUND

International recommendations in favor of screening for vaginal infection in pregnancy are based on heterogeneous criteria. In most developed countries, the diagnosis of bacterial vaginosis is only recommended for women with high-risk of preterm birth. The Nugent score is currently used, but molecular quantification tools have recently been reported with a high sensitivity and specificity. Their value for reducing preterm birth rates and related complications remains unexplored. This trial was designed to assess the cost-effectiveness of a systematic screen-and-treat program based on a point-of-care technique for rapid molecular diagnosis, immediately followed by an appropriate antibiotic treatment, to detect the presence of abnormal vaginal flora (specifically, Atopobium vaginae and Gardnerella vaginalis) before 20 weeks of gestation in pregnant women in France. We hypothesized that this program would translate into significant reductions in both the rate of preterm births and the medical costs associated with preterm birth.

METHODS/DESIGN

A multicenter, open-label randomized controlled trial (RCT) will be conducted in which 20 French obstetrics and gynecology centers will recruit eligible pregnant women at less than 20 weeks gestation with singleton pregnancy and with a low-risk factor for preterm birth. Interventions will include a) an experimental group that will receive a systematic rapid screen-and-treat program from a point-of-care analysis using a molecular quantification method and b) a control group that will receive usual care management. Randomization will be in a 1:1 allocation ratio. The primary endpoint that will be assessed over a period of 12 months will be the incremental cost-effectiveness ratio (ICER) expressed as cost per avoided preterm birth before 37 weeks. Secondary endpoints will include ICER per avoided preterm birth before 24, 28 and 32 weeks, obstetrical outcomes, neonatal outcomes, rates of treatment failure and recurrence episodes for positive women. Uncertainty surrounding these estimates will be addressed using nonparametric bootstrapping and represented using cost-effectiveness acceptability curves. A total of 6,800 pregnant women will be included.

DISCUSSION

This appropriate randomized controlled design will provide insight into the cost-effectiveness and therefore the potential cost savings of a rapid screen-and-treat strategy for molecular abnormal vaginal flora in pregnant women. National and international recommendations could be updated based on the findings of this study.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02288832 (registration date: 30 October 2014); Eudract: 2014-001559-22.

First Trimester Levels of BV-Associated Bacteria and Risk of Miscarriage Among Women Early in Pregnancy

OBJECTIVES

Prior studies have examined the role of bacterial vaginosis (BV) and increased risk of miscarriage; however the risk has been modest and many BV positive pregnant women deliver at term. BV is microbiologically heterogeneous, and thus the identification of specific BV-associated bacteria associated with miscarriage is warranted.

METHODS

We measured the presence and level of seven BV-associated bacteria prior to 14 weeks gestation among urban pregnant women seeking routine prenatal care at five urban obstetric practices at Temple University Hospital in Philadelphia PA from July 2008 through September 2011. 418 Pregnant women were included in this assessment and 74 experienced a miscarriage.

RESULTS

Mean log concentration of BVAB3 was significantly higher among women experiencing a miscarriage (4.27 vs. 3.71, p value = 0.012). Younger women with high levels of BVAB3 had the greatest risk of miscarriage. In addition, we found a significant decreased risk of miscarriage among women with higher log concentrations of Leptotrichia/Sneathia species or Megasphaera phylotype 1-like species early in pregnancy.

CONCLUSIONS FOR PRACTICE

The identification of selected vaginal bacteria associated with an increased risk of miscarriage could support screening programs early in pregnancy and promote early therapies to reduce early pregnancy loss.

The significance of Lactobacillus crispatus and L. vaginalis for vaginal health and the negative effect of recent sex: a cross-sectional descriptive study across groups of African women

BACKGROUND

Women in sub-Saharan Africa are vulnerable to acquiring HIV infection and reproductive tract infections. Bacterial vaginosis (BV), a disruption of the vaginal microbiota, has been shown to be strongly associated with HIV infection. Risk factors related to potentially protective or harmful microbiota species are not known.

METHODS

We present cross-sectional quantitative polymerase chain reaction data of the Lactobacillus genus, five Lactobacillus species, and three BV-related bacteria (Gardnerella vaginalis, Atopobium vaginae, and Prevotella bivia) together with Escherichia coli and Candida albicans in 426 African women across different groups at risk for HIV. We selected a reference group of adult HIV-negative women at average risk for HIV acquisition and compared species variations in subgroups of adolescents, HIV-negative pregnant women, women engaging in traditional vaginal practices, sex workers and a group of HIV-positive women on combination antiretroviral therapy. We explored the associations between presence and quantity of the bacteria with BV by Nugent score, in relation to several factors of known or theoretical importance.

RESULTS

The presence of species across Kenyan, South African and Rwandan women was remarkably similar and few differences were seen between the two groups of reference women in Kenya and South Africa. The Rwandan sex workers and HIV-positive women had the highest G. vaginalis presence (p = 0.006). Pregnant women had a higher Lactobacillus genus mean log (7.01 genome equivalents (geq)/ml) compared to the reference women (6.08 geq/ml). L. vaginalis (43%) was second to L. iners (81.9%) highly present in women with a normal Nugent score. Recent sexual exposure negatively affected the presence of L. crispatus (<0.001), L. vaginalis (p = 0.001), and Lactobacillus genus (p < 0.001). Having more than one sexual partner in the last three months was associated with an increased prevalence of G. vaginalis (p = 0.044) and L. iners (p = 0.001).

CONCLUSIONS

Although the composition of species across the studied African countries was similar, the presence of protective species i.e. L. crispatus and L. vaginalis in women with a normal Nugent score appeared lower compared to non-African studies. Furthermore, Lactobacillus species were negatively affected by sexual behavioural. Strategies to support protective Lactobacillus species are urgently needed.

TRIAL REGISTRATION

The study is registered at the Trial Registration at the National Health Research Ethics Council South Africa with the number DOH2709103223.

High Atopobium vaginae and Gardnerella vaginalis vaginal loads are associated with preterm birth

BACKGROUND

Bacterial vaginosis is a risk factor for preterm birth. The various conventional methods for its diagnosis are laborious and not easily reproducible. Molecular quantification methods have been reported recently, but the specific risk factors they might identify remain unclear.

METHODS

A prospective multicenter national study included pregnant women at risk of preterm birth. A quantitative molecular tool using a specific real-time polymerase chain reaction assay and serial dilutions of a plasmid suspension quantified Atopobium vaginae, Gardnerella vaginalis, lactobacilli, Mycoplasma hominis, and the human albumin gene (for quality control).

RESULTS

In 813 pregnancies, high vaginal loads of either or both of A. vaginae and G. vaginalis were associated with preterm birth (hazard ratio [HR], 3.9; 95% confidence interval {CI}, 1.1-14.1; P = .031). A high vaginal load of A. vaginae was significantly associated with shortened time to delivery and therefore pregnancy length. These times were, respectively, 152.2 and 188.2 days (HR, 5.6; 95% CI, 1.5-21.3; P < .001) before 22 weeks, 149.0 and 183.2 days (HR, 2.8; 95% CI, 1.1-8.2; P = .048) before 28 weeks, and 132.6 and 170.4 days (HR, 2.2; 95% CI, 1.1-4.6; P = .033) before 32 weeks. After multivariate analysis, A. vaginae levels ≥10(8) copies/mL remained significantly associated with delivery before 22 weeks of gestation (adjusted HR, 4.7; 95% CI, .2-17.6; P = .014).

CONCLUSIONS

High vaginal loads of A. vaginae and G. vaginalis are associated with late miscarriage and prematurity in high-risk pregnancies. A high vaginal load of A. vaginae (DNA level ≥10(8) copies/mL) identifies a population at high risk of preterm birth. Further studies that both screen for and then treat A. vaginae are needed.

CLINICAL TRIALS REGISTRATION

NCT00484653.

Association between cigarette smoking and the vaginal microbiota: a pilot study

Background

Smoking has been identified in observational studies as a risk factor for bacterial vaginosis (BV), a condition defined in part by decimation of Lactobacillus spp. The anti-estrogenic effect of smoking and trace amounts of benzo[a]pyrene diol epoxide (BPDE) may predispose women to BV. BPDE increases bacteriophage induction in Lactobacillus spp. and is found in the vaginal secretions of smokers. We compared the vaginal microbiota between smokers and non-smokers and followed microbiota changes in a smoking cessation pilot study.

Methods

In 2010–2011, 20 smokers and 20 non-smokers were recruited to a cross-sectional study (Phase A) and 9 smokers were enrolled and followed for a 12-week smoking cessation program (Phase B). Phase B included weekly behavioral counseling and nicotine patches to encourage smoking cessation. In both phases, participants self-collected mid-vaginal swabs (daily, Phase B) and completed behavioral surveys. Vaginal bacterial composition was characterized by pyrosequencing of barcoded 16S rRNA genes (V1-V3 regions). Vaginal smears were assigned Nugent Gram stain scores. Smoking status was evaluated (weekly, Phase B) using the semi-quantitative NicAlert® saliva cotinine test and carbon monoxide (CO) exhalation.

Results

In phase A, there was a significant trend for increasing saliva cotinine and CO exhalation with elevated Nugent scores (P value <0.005). Vaginal microbiota clustered into three community state types (CSTs); two dominated by Lactobacillus (L. iners, L. crispatus), and one lacking significant numbers of Lactobacillus spp. and characterized by anaerobes (termed CST-IV). Women who were observed in the low-Lactobacillus CST-IV state were 25-fold more likely to be smokers than those dominated by L. crispatus (aOR: 25.61, 95 % CI: 1.03-636.61). Four women completed Phase B. One of three who entered smoking cessation with high Nugent scores demonstrated a switch from CST-IV to a L.iners-dominated profile with a concomitant drop in Nugent scores which coincided with completion of nicotine patches. The other two women fluctuated between CST-IV and L. iners-dominated CSTs. The fourth woman had low Nugent scores with L. crispatus-dominated CSTs throughout.

Conclusion

Smokers had a lower proportion of vaginal Lactobacillus spp. compared to non-smokers. Smoking cessation should be investigated as an adjunct to reducing recurrent BV. Larger studies are needed to confirm these findings.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2334-14-471) contains supplementary material, which is available to authorized users.

Molecular analysis of the relationship between specific vaginal bacteria and bacterial vaginosis metronidazole therapy failure

Bacterial vaginosis frequently persists, even after treatment. The role of some strains of bacteria associated with bacterial vaginosis treatment failure remains poorly defined. The aim of our study was to define the risk of bacterial vaginosis treatment failure, including pre-treatment detection of specific vaginal bacteria. Bacterial vaginosis is present when the Nugent score is ≥7 and the modified Amsel criteria is positive. Women with bacterial vaginosis were treated with intravaginal metronidazole gel nightly for 5 nights. The 454 pyrosequencing method was used to detect bacteria in vaginal fluid. By univariate analysis, a history of bacterial vaginosis, intrauterine device use and the presence of Facklamia, Corynebacterium and Veillonella were significantly associated with bacterial vaginosis treatment failure. Lactobacillus crispatus, Lactobacillus pentosus and Megasphaera were significantly associated with curing bacterial vaginosis. After logistic regression analysis and detection of these bacteria for test-of-cure, we found that women who had a history of bacterial vaginosis had a higher incidence of bacterial vaginosis treatment failure, whereas women with L. crispatus had a lower incidence of treatment failure. Post-treatment sexual activity was not associated with the treatment effect. Our data suggested that treatment failure may be not caused by drug resistance. Rather, it has a closer relationship with the failed restoration of lactobacilli.

Risk factors for bacterial vaginosis: results from a cross-sectional study having a sample of 53,652 women

The aim of this study was to estimate the risk factors of bacterial vaginosis (BV) among rural married women of childbearing age in Anhui Province of China. A cross-sectional study was conducted and the method of stratified cluster sampling was used to identify a sample of 53,652 married women aged 18-49 years. All women were asked to complete an interviewer-administered standardized questionnaire, covering sociodemographic characteristics, history of menstruation, marriage and procreation, sexual life, personal hygienic behaviors, and reproductive tract infections (RTIs) knowledge, followed by the gynecological examination and laboratory inspection. A total of 53,286 married women aged 18-49 years were included in this analysis. The prevalence of BV was 11.99 % (6,391/53,286). Risk factors for BV included the minority nationality, women's lower education levels, husband's elder age, over 35 days of menstrual cycle, less than 3 days of menstruation, dysmenorrhea, usage of an intrauterine device (IUD), lack of RTIs knowledge, higher frequency of washing genitals before having sex with husband and changing underwear, lower frequency of sexual intercourse per month, and suffering from other RTIs. The results suggest that BV can be affected by many factors among rural married women of reproductive age, so comprehensive, scheduled programs at healthcare educations should be provided for women in order to prevent BV.

Early pregnancy changes in bacterial vaginosis-associated bacteria and preterm delivery

BACKGROUND

We evaluated the importance of measuring early vaginal levels of eight bacterial vaginosis (BV)-associated bacteria, at two points in pregnancy, and the risk of spontaneous preterm delivery (SPTD) among pregnant women and the subgroup of pregnant women with a history of preterm delivery (PTD).

METHODS

This prospective cohort study enrolled women at five urban obstetric practices at Temple University Hospital in Philadelphia PA. Women with singleton pregnancies less than 16 weeks gestation self-collected vaginal swabs at two points in pregnancy, prior to 16 weeks gestation and between 20-24 weeks gestation, to measure the presence and level of eight BV-associated bacteria. Women were followed-up for gestational age at delivery via medical records.

RESULTS

Among women reporting a prior PTD, women with higher levels of Leptotrichia/Sneathia species, BVAB1 and Mobiluncus spp., prior to 16 weeks gestation, were significantly more likely to experience a SPTD. In addition, pregnant women with a prior PTD and increasing levels of Leptotrichia/Sneathia species (aOR: 9.1, 95% CI 1.9, 42.9), BVAB1 (aOR: 16.4, 95% CI 4.3, 62.7) or Megasphaera phylotype 1 (aOR: 6.2, 95% CI 1.9, 20.6), through 24 weeks gestation, were significantly more likely to experience an SPTD. Among the overall group of pregnant women, the levels of BV-associated bacteria were not related to SPTD.

CONCLUSION

Among the group of women reporting a prior PTD, increasing levels of BVAB1, Leptotrichia/Sneathia species, and Megasphaera phylotype 1, through mid-pregnancy were related to an increased risk of SPTD.

Relationship of selected bacterial vaginosis-associated bacteria to Nugent score bacterial vaginosis among urban women early in pregnancy

Among urban, primarily African American pregnant women, 74% were identified with Nugent score bacterial vaginosis (BV). All BV-associated bacteria were more prevalent among women with Nugent score BV. Bacterial vaginosis-associated bacteria 3 (BVAB3) had the highest positive predictive value, whereas Gardnerella vaginalis and Atopobium spp. had the highest sensitivity. Atopobium spp. levels had the most significant area under the curve.

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

BACKGROUND AND OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Vaginal microbiome and sexually transmitted infections: an epidemiologic perspective

Vaginal bacterial communities are thought to help prevent sexually transmitted infections. Bacterial vaginosis (BV) is a common clinical syndrome in which the protective lactic acid-producing bacteria (mainly species of the Lactobacillus genus) are supplanted by a diverse array of anaerobic bacteria. Epidemiologically, BV has been shown to be an independent risk factor for adverse outcomes including preterm birth, development of pelvic inflammatory disease, and acquisition of sexually transmitted infections. Longitudinal studies of the vaginal microbiome using molecular techniques such as 16S ribosomal DNA analysis may lead to interventions that shift the vaginal microbiota toward more protective states.