Quantitative bacteriology of the vaginal flora

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.

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.

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 Cervicovaginal Mucus Barrier

Preterm births are a global health priority that affects 15 million babies every year worldwide. There are no effective prognostic and therapeutic strategies relating to preterm delivery, but uterine infections appear to be a major cause. The vaginal epithelium is covered by the cervicovaginal mucus, which is essential to health because of its direct involvement in reproduction and functions as a selective barrier by sheltering the beneficial lactobacilli while helping to clear pathogens. During pregnancy, the cervical canal is sealed with a cervical mucus plug that prevents the vaginal flora from ascending toward the uterine compartment, which protects the fetus from pathogens. Abnormalities of the cervical mucus plug and bacterial vaginosis are associated with a higher risk of preterm delivery. This review addresses the current understanding of the cervicovaginal mucus and the cervical mucus plug and their interactions with the microbial communities in both the physiological state and bacterial vaginosis, with a focus on gel-forming mucins. We also review the current state of knowledge of gel-forming mucins contained in mouse cervicovaginal mucus and the mouse models used to study bacterial vaginosis.

Peritonitis during Continuous Ambulatory Peritoneal Dialysis (CAPD): Risk Factors, Clinical Severity, and Pathogenetic Aspects

This study of 228 episodes of peritonitis occurring during a total observation time of 2365 treatment months over a six-year period in a uniformly selected, trained, and treated continuous ambulatory peritoneal dialysis (CAPD) population (N = 124) showed the following major findings: 1) the risk of developing peritonitis was 55% within the first year and 89% within the first three years on CAPD; 2) high age (≥60 years) and year of CAPD start were risk factors for peritonitis; 3) neither sex, diabetes, or hypoalbuminemia were found to be risk factors for peritonitis; 4) the year of start, but neither the degree of severity, nor the time of the first episode affected the risk of developing a second episode of peritonitis; 5) no specific characteristics were identified in patients with the highest mean peritonitis incidence or in the patients without peritonitis; 6) in 27% of all episodes, turbidity of the dialysate was the only clinical finding; 7) the proportion of asymptomatic episodes was lower in patients ≥ 60 years; 8) the degree of clinical severity of peritonitis was not statistically influenced by the number of previous episodes; 9) the cause of peritonitis was established in only 26% of all cases; and 10) no statistical association was found between the cause of peritonitis and patient characteristics.

Vaginosis. Vaginal microbiota

The latest advances in the vaginal microbiome and molecular diagnosis of bacterial vaginosis have allowed for a better knowledge of this entity, characterising aspects of its pathogenesis and the establishment of the vaginal biolayer, the models and new theories of its aetiology, how it is transmitted, with it being considered nowadays as a probable sexually transmitted infection, the separation of other entities such as aerobic vaginosis, its molecular diagnosis and treatment with new molecules to prevent frequent relapses. This entity and the study of the vaginal microbiome have made it possible to consider these infections as a polymicrobial syndrome, putting an end to the dogma: one microorganism, one disease. In addition, a lesser-known entity such as aerobic vaginosis and the methods for its detection are updated.

Female radical cystectomy patients have a higher risk of surgical site infections

INTRODUCTION

Surgical site infections (SSI) are common after radical cystectomy. The objectives of this study were to evaluate if female sex is associated with postoperative SSI and if experiencing an SSI was associated with subsequent adverse events.

METHODS

This was a historical cohort study of radical cystectomy patients from the American College of Surgeons' National Surgical Quality Improvement Program database between 2006 and 2016. The primary outcome was development of a SSI (superficial, deep, or organ/abdominal space) within 30 days of surgery. Multivariable logistic regression analyses were performed to determine the association between sex and other patient/procedural factors with SSI. Female patients with SSI were also compared to those without SSI to determine risk of subsequent adverse events.

RESULTS

A total of 9,275 radical cystectomy patients met the inclusion criteria. SSI occurred in 1,277(13.7%) patients, 308 (16.4%) females and 969 (13.1%) males (odds ratio = 1.27; 95% confidence interval 1.10-1.47; P = 0.009). Infections were superficial in 150 (8.0%) females versus 410 (5.5%) males (P < 0.0001), deep in 40 (2.1%) females versus 114 (1.5%) males (P = 0.07), and organ/abdominal space in 118 (6.2%) females versus 445 (6.0%) males (P = 0.66). On multivariable analysis, female sex was independently associated with SSI (odds ratio = 1.21 confidence interval 1.01-1.43 P = 0.03). Females who experience SSI had higher probability of developing other complications including wound dehiscence, septic shock, and need for reoperation (all P < 0.05).

CONCLUSIONS

Female sex is an independent risk factor for SSI following radical cystectomy. More detailed study of patient factors, pathogenic microbes, and treatment factors are needed to prescribe the best measures for infection prophylaxis.

Comparative phase I randomized open-label pilot clinical trial of Gynophilus® (Lcr regenerans®) immediate release capsules versus slow release muco-adhesive tablets

Gynophilus^® (Lcr regenerans^®) is a live biotherapeutic product (LBP) that contains the live biotherapeutic microorganism Lactobacillus rhamnosus Lcr35^®, which is indicated to restore vaginal health. The aim of the study was to compare the safety, ease of use, and compliance of two formulations (immediate release: IR capsule and slow release: SR muco-adhesive tablets) as well as the colonization of Lcr35^® in healthy women. This phase I study (Comprigel) is a parallel, randomized, 4-arm, and open-label clinical trial evaluating an IR daily capsule formulation vs. a SR tablet administered every 3, 4, or 5 days for 21 days. Self-collected vaginal swabs were used to quantify Lcr35^® and characterize the composition and structure of the vaginal microbiota. Both LBPs were well-tolerated, and no severe adverse effects were reported. All groups had Lcr35^® vaginal concentrations over 10⁷ colony forming unit per milliliter of vaginal secretion on each day in the study. The new Gynophilus^® slow release tablets administered either every 3, 4, or 5 days provided vaginal concentrations that were not significantly different from those of classic Gynophilus^® (capsule) once-a-day regimen. The LBPs and the different regimens did not adversely influence the abundance of native Lactobacillus spp. and indeed tended to favor their growth and reduce colonization by non-Lactobacillus spp. This study illustrates that the SR muco-adhesive LBP tablet (Gynophilus^® SR) administered every 3 or 4 days as a safe, well-tolerated, and efficacious alternative to a more demanding IR daily capsule and could protect women's healthy vaginal microbiome by promoting endogenous Lactobacillus spp.

Comparative Study on the Vaginal Flora and Incidence of Asymptomatic Vaginosis among Healthy Women and in Women with Infertility Problems of Reproductive Age

INTRODUCTION

The normal vaginal flora is highly complex, dominated by lactobacilli of doderlein that plays a vital role in maintaining the women's health and inhibits other pathogenic microorganisms. Fluctuation in local environment or exposure to any exogenous and endogenous sources changes the vaginal flora over a period of time. Disruption of the vaginal ecosystem changes the microflora of the healthy vagina, altering the pH and predisposing to lower reproductive tract infections. The change in the microflora of the female genital tract by pathogenic organisms may ascend from vagina to upper genital tract and may cause infertility. Although several studies demonstrate a higher prevalence of bacterial vaginosis in infertile population. The role of vaginal microbiome in infertility is not clear and need to be explored further.

AIM

To compare the vaginal flora and analyse the incidence of asymptomatic vaginosis among healthy women and in women with infertility problems.

MATERIALS AND METHODS

A cross-sectional study was conducted over a period of six months at Sri Lakshmi Narayana Medical College and Hospital Puducherry, India. A total of 200 high vaginal swabs were collected from Group 1 which included 84 healthy women with regular menstrual cycles without any gynaecological disorder and from Group 2, 116 women with infertility problems attending fertility clinic within the age group of 18 to 45 years. All swabs were subjected to routine aerobic, anaerobic and fungal culture. Saline wet mount was performed for the detection of clue cells and Trichomonas vaginalis, 10% KOH was performed for demonstration of budding yeast cells and pseudo hyphae, Gram's staining to determine the presence of yeast cells, leucocytes and bacterial morphotypes. The smear was also graded using Nugent scoring system.

RESULTS

The vaginal flora of Group 1 was dominated by Lactobacillus (40, 27.8 %) followed by Micrococcus (22, 15.3 %), Enterococcus (16, 11.1%), Coagulase negative Staphylococcus spp. (12, 8.3%). Whereas in Group 2, the most dominant flora was Candida spp. (30, 26.5 %), Enterococcus (26, 23%) followed by Gram negative bacilli such as E. coli (16, 14.1 %). The percentage of Lactobacillus in Group 2 women with infertility problems was relatively low (4, 3.5%). Asymptomatic vaginosis was present in 32 (27.6 %) of Group 2 women compared to Group 1 women were only 6 (7.1%) had asymptomatic vaginosis.

CONCLUSION

Women with infertility problems showed higher prevalence of asymptomatic vaginosis and abundance of Bacterial Vaginosis (BV) associated bacteria compared to healthy women. Hence, this study recommends the screening of vaginal flora as a routine for all women, especially in women undergoing infertility treatment and also suggests the importance of vaginal culture and sensitivity in routine practice.

Etiology of bacterial vaginosis and polymicrobial biofilm formation

Microorganisms in nature rarely exist in a planktonic form, but in the form of biofilms. Biofilms have been identified as the cause of many chronic and persistent infections and have been implicated in the etiology of bacterial vaginosis (BV). Bacterial vaginosis is the most common form of vaginal infection in women of reproductive age. Similar to other biofilm infections, BV biofilms protect the BV-related bacteria against antibiotics and cause recurrent BV. In this review, an overview of BV-related bacteria, conceptual models and the stages involved in the polymicrobial BV biofilm formation will be discussed.

Urogenital Ageing

Urogenital complaints such as vaginal discomfort, dysuria, dyspareunia, recurrent lower urinary tract infections and urinary incontinence are more common in women after the menopause. Epidemiological studies have demonstrated that more than 50% of postmenopausal women suffer from at least one of these symptoms. They cause not only discomfort, but may also negatively influence sexual health. Many women are so embarrassed that they are unable to discuss their dilemma with other women or their doctor. Embryologically the female genital tract and urinary systems develop in close proximity, both arising from the primitive urogenital sinus. Animal and human studies have shown that the urethra is oestrogen sensitive, and oestrogen receptors have been identified in the urethra, urinary bladder, the vagina and the pelvic floor muscles. There is now a wealth of evidence to support the efficacy of exogenous oestrogens in the treatment of urogenital symptoms caused by postmenopausal ovarian insufficiency.

Increased Risk of Endometriosis in Patients With Lower Genital Tract Infection: A Nationwide Cohort Study

Endometriosis results from the ectopic invasion of endometrial glands and stroma in the peritoneal cavity. The exact etiology of endometriosis is still unknown. It has, however, been shown that there are higher numbers of Escherichia coli in menstrual blood, and higher endotoxin levels in menstrual fluid, as well as, in the peritoneal fluid of patients with endometriosis. In this study, we aimed to determine whether lower genital tract infections could increase the risk of endometriosis.We used the Taiwan National Health Insurance database to conduct a population-based cohort study. We included patients diagnosed with inflammatory diseases of the cervix, vagina, and vulva, and a control group comprising patients matched by age, sex, and comorbidities but without inflammatory diseases of the cervix, vagina, or vulva.A total of 79,512 patients were included in the inflammatory disease group and an equal number of control individuals were selected. The incidence of endometriosis (hazard ratio, 2.01; 95% confidence interval, 1.91-2.12; P < 0.001) was higher among patients than controls. Cox proportional hazards models showed that irrespective of comorbidities, lower genital tract infection was an independent risk factor for endometriosis.Patients with lower genital tract infections exhibit a substantially higher risk for developing endometriosis.

Staphylococcus aureus toxic shock syndrome toxin-1 (TSST-1) production and Lactobacillus species growth in a defined medium simulating vaginal secretions

Lactobacillus species are commensal with the healthy vaginal environment and inhibit the growth of many pathogenic bacteria in the vaginal tract by a variety of mechanisms, such as the production of hydrogen peroxide, organic acids, and antimicrobial substances. Simulation of the vaginal environment is crucial for proper investigation of the effects of Lactobacillus species on pathogenic bacteria. In this study, we modified a medium used to simulate vaginal secretions to improve the growth of toxic shock syndrome toxin-1 (TSST-1)-producing Staphylococcus aureus clinical strains and Lactobacillus species so that interactions between these bacteria may be examined. A medium consisting of basal salts, vitamins, albumin, glycogen, mucin, urea, sodium bicarbonate, polyoxyethylene sorbitan monolaurate, and amino acids supported the growth of S. aureus and the production of TSST-1 as determined by Western analysis. Improved growth of the Lactobacillus species was seen when this same medium was supplemented with manganese chloride, sodium acetate, and an increase in glucose concentration. However, growth of S. aureus in the supplemented medium resulted in reduced levels of TSST-1. Production of TSST-1 was not detected in a medium routinely used for the growth of Lactobacillus species although S. aureus growth was not inhibited. The development of an improved genital tract secretion medium provides a more authentic environment in which to study the interactions of Lactobacillus species and vaginal pathogens, such as S. aureus.

Prophylactic antibiotics in obstetrics–gynecology: a current asset, a future liability?

Currently, prophylactic antibiotics have proven effective in lowering the postoperative and postprocedure infection rate following vaginal hysterectomy, emergency cesarean section for the patient in labor, radical hysterectomy, abdominal hysterectomy, pregnancy termination, hysterosalpingogram and intrauterine device insertion. Guidelines for the most effective and safe use are presented. Concerns are raised regarding the widespread prolonged use of prophylactic antibiotics on women in labor to prevent Group B streptococcal infections in newborn children and women with prolonged preterm membrane rupture. There is also an awareness needed of a growing incidence of infections seen in the hospital from community-acquired methicillin-resistant Staphylococcus aureus and Clostridium difficile. These problems have not been addressed by the current prophylactic antibiotic strategies.

Microbiota and pelvic inflammatory disease

Female genital tract microbiota play a crucial role in maintaining health. Disequilibrium of the microbiota has been associated with increased risk of pelvic infections. In recent years, culture-independent molecular techniques have expanded understanding of the composition of genital microbiota and the dynamic nature of the microbiota. There is evidence that upper genital tract may not be sterile and may harbor microflora in the physiologic state. The isolation of bacterial vaginosis-associated organisms in women with genital infections establishes a link between pelvic infections and abnormal vaginal flora. With the understanding of the composition of the microbiota in healthy and diseased states, the next logical step is to identify the function of the newly identified microbes. This knowledge will further expand our understanding of the causation of pelvic infections, which may lead to more effective prevention and treatment strategies.

Characterization of the vaginal microbiota of healthy Canadian women through the menstrual cycle

BACKGROUND

The vaginal microbial community plays a vital role in maintaining women's health. Understanding the precise bacterial composition is challenging because of the diverse and difficult-to-culture nature of many bacterial constituents, necessitating culture-independent methodology. During a natural menstrual cycle, physiological changes could have an impact on bacterial growth, colonization, and community structure. The objective of this study was to assess the stability of the vaginal microbiome of healthy Canadian women throughout a menstrual cycle by using cpn60-based microbiota analysis. Vaginal swabs from 27 naturally cycling reproductive-age women were collected weekly through a single menstrual cycle. Polymerase chain reaction (PCR) was performed to amplify the universal target region of the cpn60 gene and generate amplicons representative of the microbial community. Amplicons were pyrosequenced, assembled into operational taxonomic units, and analyzed. Samples were also assayed for total 16S rRNA gene content and Gardnerella vaginalis by quantitative PCR and screened for the presence of Mollicutes by using family and genus-specific PCR.

RESULTS

Overall, the vaginal microbiome of most women remained relatively stable throughout the menstrual cycle, with little variation in diversity and only modest fluctuations in species richness. Microbiomes between women were more different than were those collected consecutively from individual women. Clustering of microbial profiles revealed the expected groupings dominated by Lactobacillus crispatus, Lactobacillus iners, and Lactobacillus jensenii. Interestingly, two additional clusters were dominated by either Bifidobacterium breve or a heterogeneous mixture of nonlactobacilli. Direct G. vaginalis quantification correlated strongly with its pyrosequencing-read abundance, and Mollicutes, including Mycoplasma hominis, Ureaplasma parvum, and Ureaplasma urealyticum, were detected in most samples.

CONCLUSIONS

Our cpn60-based investigation of the vaginal microbiome demonstrated that in healthy women most vaginal microbiomes remained stable through their menstrual cycle. Of interest in these findings was the presence of Bifidobacteriales beyond just Gardnerella species. Bifidobacteriales are frequently underrepresented in 16S rRNA gene-based studies, and their detection by cpn60-based investigation suggests that their significance in the vaginal community may be underappreciated.

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.

Longitudinal study of the dynamics of vaginal microflora during two consecutive menstrual cycles

Background

Although the vaginal microflora (VMF) has been well studied, information on the fluctuation of the different bacterial species throughout the menstrual cycle and the information on events preceding the presence of disturbed VMF is still very limited. Documenting the dynamics of the VMF during the menstrual cycle might provide better insights. In this study, we assessed the presence of different Lactobacillus species in relation to the BV associated species during the menstrual cycle, assessed the influence of the menstrual cycle on the different categories of vaginal microflora and assessed possible causes, such as menstruation and sexual intercourse, of VMF disturbance. To our knowledge, this is the first longitudinal study in which swabs and Gram stains were available for each day of two consecutive menstrual cycles, whereby 8 grades of VMF were distinguished by Gram stain analysis, and whereby the swabs were cultured every 7^th day and identification of the bacterial isolates was carried out with a molecular technique.

Methods

Self-collected vaginal swabs were obtained daily from 17 non pregnant, menarchal volunteers, and used for daily Gram staining and weekly culture. Bacterial isolates were identified with tDNA-PCR and 16 S rRNA gene sequencing.

Results

Nine women presented with predominantly normal VMF and the 8 others had predominantly disturbed VMF. The overall VMF of each volunteer was characteristic and rather stable. Menses and antimicrobials were the major disturbing factors of the VMF. Disturbances were always accompanied by a rise in Gram positive cocci, which also appeared to be a significant group within the VMF in general.

Conclusions

We observed a huge interindividual variability of predominantly stable VMF types. The importance of Gram positive cocci in VMF is underestimated. L. crispatus was the species that was most negatively affected by the menses, whereas the presence of the other lactobacilli was less variable.

Bacterial vaginosis: Etiology and modalities of treatment-A brief note

A large women population of the world is suffering from a vaginal infection commonly known as bacterial vaginosis. The disease is associated with the decrease in the lactobacilli count in the vagina. Till date, there is a lack of full proof treatment modalities for the cure of the disease. The treatment includes the use of antimicrobials and/or acidifying agents and probiotics, either separately or in combination. This note discusses about the etiology and the various present-day modalities of treatment of bacterial vaginosis.

The Lactobacillus flora in vagina and rectum of fertile and postmenopausal healthy Swedish women

Background

Lactobacillus species are the most often found inhabitants of vaginal ecosystem of fertile women. In postmenopausal women with low oestrogen levels, Lactobacillus flora is diminishing or absent. However, no studies have been performed to investigate the correlation between oestrogen levels and the lactobacilli in the gut. The aim of the present study was to investigate the relation in healthy women between vaginal and rectal microbial flora as well as possible variations with hormone levels.

Methods

Vaginal and rectal smears were taken from 20 healthy fertile women, average 40 years (range 28-49 years), in two different phases of the menstrual cycle, and from 20 postmenopausal women, average 60 years (range 52-85 years). Serum sex hormone levels were analyzed. Bacteria from the smears isolated on Rogosa Agar were grouped by Randomly Amplified Polymorphic DNA and identified by multiplex PCR and partial 16S rRNA gene sequencing.

Results

Lactobacillus crispatus was more often found in the vaginal flora of fertile women than in that of postmenopausal (p = 0.036). Fifteen of 20 fertile women had lactobacilli in their rectal smears compared to 10 postmenopausal women (p = 0.071). There was no correlation between the number of bacteria in vagina and rectum, or between the number of bacteria and hormonal levels. Neither could any association between the presence of rectal lactobacilli and hormonal levels be found.

Conclusion

Lactobacillus crispatus was more prevalent in the vaginal flora of fertile women, whereas the Lactobacillus flora of rectum did not correlate to the vaginal flora nor to hormonal levels.

Rapid fluctuation of the vaginal microbiota measured by Gram stain analysis

BACKGROUND

The aetiology of bacterial vaginosis (BV) remains unknown.

OBJECTIVE

To describe longitudinal changes in vaginal microbiota.

METHODS

Thirty-nine women (mean age 36.8 years; 22 (56.4%) African-American) self-collected vaginal specimens twice weekly for 16 weeks as part of a vaginal douching cessation study. In an analysis where each woman serves as her own control, conditional logistic regression was used to evaluate daily, time-varying factors associated with a woman's incident BV episode(s) as compared with her persistently BV-negative sample(s). BV was defined by a Nugent's Gram stain score >or=7.

RESULTS

46.2% of participants had BV in the first 4 weeks of observation. Rapid fluctuation of vaginal microbiota was observed in 226 transitions to BV or spontaneous remission. Duration of BV was often short: 51% of the episodes lasted for only one sample interval (3 days). Among women who had at least one BV episode, the median number of episodes per woman was 8.7 (SD 7.4, range 1-22). Lubricant use 1 day before specimen collection (adjusted OR (aOR)=11.75, 95% CI 1.96 to 70.27) and rectal sex 2 days before (aOR=4.48, 95% CI 2.79 to 7.17) were associated with BV onset.

CONCLUSION

Rapid fluctuation of the vaginal microbiota was seen. Longitudinal studies with long intervals between sampling are likely to miss episodes of BV. Recent report of lubricant use and rectal sex were associated with incident BV.

Frequency of detection of methicillin-resistant Staphylococcus aureus from rectovaginal swabs in pregnant women

Clinical samples from 250 pregnant women undergoing screening for rectovaginal group B streptococcus colonization were evaluated concurrently for the presence of methicillin-resistant Staphylococcus aureus (MRSA). Overall, S aureus was detected in 21.6% of the women; 53.7% of the isolates were MRSA. Despite a lack of risk factors for MRSA colonization, rectovaginal MRSA was detected in 10.4% of pregnant women in this study.

Dynamics of the Vaginal Ecosystem—Hormonal Influences

The vagina is a dynamic and finely tuned ecosystem in which homeostasis depends on mutually beneficial interactions between a human female and her resident microorganisms, an ecosystem that can be thrown off balance by a wide variety of both intrinsic and extrinsic factors. Although a functional equilibrium provides stability to the ecosystem considered crucial to maintaining vaginal health, “normal flora” is a concept currently being redefined. New methodologies enable molecular analyses of the vaginal microbiota which have widened the definition of “normal” from a single specific microbiological profile to a range of functional microbial equilibria dependent upon pertinent host and microbial factors. One of the strongest influences on the vaginal microbiota is the hormonal changes that define the reproductive phases of a woman's life. The vaginal environment is particularly responsive to estrogen, a hormone that creates distinctive changes in the vaginal microbiota. This review summarizes the components of a healthy vaginal ecosystem during the reproductive years, including the characteristics of a healthy equilibrium and factors that can disturb a functional balance. It also summarizes what is known about the vaginal microbiota in childhood and after menopause. Healthful ecosystems at any stage of a female's reproductive life will be characterized by a microbiota that both maintains physiological function and though changeable, adapts to normal perturbation without succumbing to disease.

Heterosexual spread of HIV infection

Sexual transmission is the most common route of spread of human immunodeficiency virus (HIV), with heterosexual transmission of HIV infection accounting for 90% of those infected in 1992 and over 75% of the 10–12 million of those infected to date worldwide. Yet, heterosexual transmission is poorly understood. Since HIV can be transmitted from HIV-infected people who are asymptomatic as well as from those who have the acquired immunodeficiency syndrome (AIDS), we must better define the potential for transmission of HIV from HIV-infected individuals as well as the factors which influence the susceptibility of HIV-uninfected individuals.

The effect of vaginal douching cessation on bacterial vaginosis: a pilot study

OBJECTIVE

The objective of the study was to evaluate the risk for bacterial vaginosis (BV) in a douching cessation trial.

STUDY DESIGN

Thirty-nine reproductive-age women who reported use of douche products were enrolled into a 20-week study consisting of a 4 week douching observation (phase I) followed by 12-weeks of douching cessation (phase II). In phase III, participants then chose to resume douching or continue cessation for the remaining 4 weeks. Self-collected vaginal samples were obtained twice weekly in the first 16 weeks, and 1 sample was collected during week 20 (1107 samples total). BV was diagnosed by Nugent score of 7 or greater. Conditional logistic regression was used to evaluate douching cessation on the risk of BV.

RESULTS

The adjusted odds ratio (aOR) for BV in the douching cessation phase, as compared with the douching-observation phase was 0.76 (95% confidence interval [CI], 0.33 to 1.76). Among women who reported their primary reason for douching was to cleanse after menstruation, BV was significantly reduced in douching cessation (aOR:0.23; 95% CI, 0.12 to 0.44).

CONCLUSION

Vaginal douching cessation may reduce the risk for BV in a subset of women.

Flow cytometric quantification of bacteria in vaginal swab samples self-collected by adolescents attending a gynecology clinic

Bacterial vaginosis (BV) is an important risk factor in reproductive health outcomes, such as pre-term birth and sexually transmitted infections including HIV. However, its etiology, diagnosis and treatment remain poorly defined. We evaluated flow cytometry as a tool to quantify total bacterial cells in vaginal specimens self-collected longitudinally by adolescents. BV was diagnosed by Gram-stain (criteria of Hay and Ison). Average flow cytometric counts of bacterial cell-units (BCU) was log(10) 8.04 per gram sample and was found to correlate with sample weight (p<0.0001). BV was frequently observed in this group, with 22 of 32 participants (69%) diagnosed with BV for at least one timepoint. Surprisingly, increased BCU was associated with normal Hay-Ison score (p=0.0003), even when adjusting for sample weight (p=0.02). Since presence and quantity of Lactobacillus defines normal vaginal microbiology (ie. absence of BV), this result indicates a possible bias towards dominance of Lactobacillus cells in measurements of "total" BCU. Increased BCU per gram was associated in multivariate analysis with longer self-reported time since last menstruation (p=0.004) and last sexual intercourse (p=0.007). Sperm was detected in 3 samples provided by those reporting sexual intercourse in the previous 24 h. Light-scattering profiles of bacteria and vaginal cells in samples collected over time from an individual were often identical and distinct from other individuals. To our knowledge, this is the first description of flow cytometry for analysis of commensal bacteria in vaginal specimens. Further development may help to illuminate the complex dynamics of vaginal microbial communities underlying BV.

Human infection with Fusobacterium necrophorum (Necrobacillosis), with a focus on Lemierre's syndrome

Human infection with Fusobacterium necrophorum usually involves F. necrophorum subsp. funduliforme rather than F. necrophorum subsp. necrophorum, which is a common pathogen in animals. Lemierre's syndrome, or postanginal sepsis, is the most common life-threatening manifestation. Tonsillitis is followed by septic thrombophlebitis of the internal jugular vein and then a septicemia with septic emboli in lungs and other sites. Recent evidence suggests that F. necrophorum can be limited to the throat and cause persistent or recurrent tonsillitis. F. necrophorum is unique among non-spore-forming anaerobes, first for its virulence and association with Lemierre's syndrome as a monomicrobial infection and second because it seems probable that it is an exogenously acquired infection. The source of infection is unclear; suggestions include acquisition from animals or human-to-human transmission. Approximately 10% of published cases are associated with infectious mononucleosis, which may facilitate invasion. Recent work suggests that underlying thrombophilia may predispose to internal jugular vein thrombophlebitis. Lemierre's syndrome was relatively common in the preantibiotic era but seemed to virtually disappear with widespread use of antibiotics for upper respiratory tract infection. In the last 15 years there has been a rise in incidence, possibly related to restriction in antibiotic use for sore throat.

The effects of intravaginal clindamycin and metronidazole therapy on vaginal lactobacilli in patients with bacterial vaginosis

OBJECTIVE

The purpose of this study was to determine the effects of 3 intravaginal antibacterial treatments on vaginal lactobacilli in patients with bacterial vaginosis (BV).

STUDY DESIGN

Retrospective analyses were performed on Lactobacillus scores from 3 similar studies evaluating 2 2% clindamycin vaginal creams and 0.75% metronidazole gel at baseline and at 21 to 30 days in 408 patients with BV. Scores were compared using a 1-way global F test and McNemar's test.

RESULTS

All groups had similar mean Lactobacillus scores at baseline (P = 0.37) and at 21 to 30 days (P = .71). The 3 groups were also comparable at both visits with respect to the distributions of scores within each group. In all groups, there was significant improvement in the percentages of patients with no lactobacilli present at 21 to 30 days compared with baseline (P < .0001 for all comparisons).

CONCLUSION

Clindamycin and metronidazole promoted similar levels of restoration of vaginal lactobacilli at 21 to 30 days.

Metronidazole with Lactacyd vaginal gel in bacterial vaginosis

AIM

To assess the efficacy and tolerability of lactic acid (Lactacyd vaginal gel; LVG) when given as an adjunct to metronidazole in the treatment of bacterial vaginosis (BV) among Filipino patients.

METHODS

A multicenter, open-labeled, controlled, randomized, three-arm comparative study on 90 women aged 18 years or over with clinically and microbiologically proven BV.

RESULTS

The lactobacilli colony count significantly increased over time in all three arms. At day 14, growth of lactobacilli was significantly higher among patients in the lactic acid gel and combination treatment arms. Significant reduction of malodorous vaginal discharge (whiff test) and lowest recurrence of BV were noted in the metronidazole plus lactic acid gel arm. Regarding disappearance of signs of BV, there was significant decrease in the pH level and frequency of clue cell positive patients across time but was not significantly different across treatment groups. Only one patient (3%, 1/60) among those who received lactic acid gel complained of increased curd-like discharge. Six patients (10%, 6/60) who received metronidazole complained of epigastric pain/discomfort, dizziness and dyspnea.

CONCLUSIONS

Lactic acid gel (LVG) is safe and as efficacious as metronidazole in the treatment of BV. There is evidence that LVG when combined with metronidazole is superior to metronidazole alone in promoting lactobacilli colonization. LVG as an adjunct to metronidazole, having the least number of recurrent BV, appears to result in better long-term treatment effect on bacterial vaginosis.

Characterization of microbial communities found in the human vagina by analysis of terminal restriction fragment length polymorphisms of 16S rRNA genes

To define and monitor the structure of microbial communities found in the human vagina, a cultivation-independent approach based on analyses of terminal restriction fragment length polymorphisms (T-RFLP) of 16S rRNA genes was developed and validated. Sixteen bacterial strains commonly found in the human vagina were used to construct model communities that were subsequently used to develop efficient means for the isolation of genomic DNA and an optimal strategy for T-RFLP analyses. The various genera in the model community could best be resolved by digesting amplicons made using bacterial primers 8f and 926r with HaeIII; fewer strains could be resolved using other primer-enzyme combinations, and no combination successfully distinguished certain species of the same genus. To demonstrate the utility of the approach, samples from five women that had been collected over a 2-month period were analyzed. Differences and similarities among the vaginal microbial communities of the women were readily apparent. The T-RFLP data suggest that the communities of three women were dominated by a single phylotype, most likely species of Lactobacillus. In contrast, the communities of two other women included numerically abundant populations that differed from Lactobacillus strains whose 16S rRNA genes had been previously determined. The T-RFLP profiles of samples from all the women were largely invariant over time, indicating that the kinds and abundances of the numerically dominant populations were relatively stable throughout two menstrual cycles. These findings show that T-RFLP of 16S rRNA genes can be used to compare vaginal microbial communities and gain information about the numerically dominant populations that are present.

Bacterial vaginosis in relation to menstrual cycle, menstrual protection method, and sexual intercourse in rural Gambian women

OBJECTIVE

To examine the occurrence of bacterial vaginosis (BV) over the menstrual cycle and in relation to menstrual protection materials and sexual intercourse in a rural African setting.

METHODS

Married, regularly menstruating female volunteers were asked to collect self administered swabs on alternate days through four menstrual cycles. BV was assessed using Nugent scores. Menstruation and reported sexual intercourse data were recorded contemporaneously. A crossover design comparing traditional and modern menstrual protection methods was incorporated. Multivariate logistic regression was used to examine associations with BV.

RESULTS

30 women completed four menstrual cycles in the study. Completeness and validity of data from the self administered swabs was high. Greater frequencies of BV were found for all women in the second week of the menstrual cycle relative to days 14+, and markedly higher frequencies of BV were found in the first week in women with infrequent BV. BV was (non-significantly) more frequent when modern pads were used compared with traditional cloths. No association was found between BV and intercourse reported in the previous 4 days; or between the frequency of reported intercourse in one menstrual cycle and BV in either the same menstrual cycle or the next.

CONCLUSIONS

Similar transient fluctuations over the menstrual cycle were found to those in industrialised countries. We found no evidence that sexual intercourse was associated with increased frequency of BV. Our data do not support hypotheses that menstrual hygiene materials might explain the high prevalences of BV found in sub-Saharan Africa compared to industrialised countries.

Association between vaginal 70-kd heat shock protein, interleukin-1 receptor antagonist, and microbial flora in mid trimester pregnant women

OBJECTIVE

This study investigated the association among the inducible 70-kd heat shock protein, cytokines, and microbial flora in the vagina in mid trimester pregnant women and subsequent preterm delivery.

STUDY DESIGN

Vaginal samples from 205 pregnant women, which were collected at 18 to 22 weeks of gestation, were analyzed for qualitative and quantitative vaginal microflora and for 70-kd heat shock protein, interleukin-1beta, interleukin-1 receptor antagonist, and tumor necrosis factor-alpha by enzyme-linked immunosorbent assay. Pregnancy outcome data were obtained subsequently.

RESULTS

The 70-kd heat shock protein was detected in 38 vaginal samples (18.5%). Its presence was associated with elevated vaginal pH, a diagnosis of bacterial vaginosis, and elevated interleukin-1 receptor antagonist levels (P < .001). Among women with bacterial vaginosis, 70-kd heat shock protein-positive subjects had a >80% increase in median vaginal concentration of interleukin-1 receptor antagonist (P < .05).

CONCLUSION

Vaginal 70-kd heat shock protein expression is associated with the down-regulation of the proinflammatory immune response to abnormal vaginal flora in mid trimester pregnant women.

Peripartum bacteremias due to Leptotrichia amnionii and Sneathia sanguinegens, rare causes of fever during and after delivery

We report three cases of delivery and postpartum bacteremia due to unusual anaerobic bacteria in healthy young women. Leptotrichia amnionii bacteremia occurred during delivery in two mothers and was associated with fetal distress during labor. Conversely, Sneathia sanguinegens bacteremia occurred postpartum, 2 days after delivery, without consequence for the neonate.

Polymorphism in intron 2 of the interleukin-1 receptor antagonist gene, local midtrimester cytokine response to vaginal flora, and subsequent preterm birth

OBJECTIVE

This study investigated the association between polymorphism in intron 2 of the interleukin-1 receptor antagonist gene, midtrimester vaginal microflora, vaginal interleukin receptor antagonist and interleukin-1beta levels and subsequent spontaneous preterm birth.

STUDY DESIGN

Vaginal samples from 212 women, collected at 18-22 weeks' gestation, were analyzed for the polymorphism in intron 2 of the interleukin-1 receptor antagonist gene by polymerase chain reaction, qualitative and quantitative vaginal microflora, and interleukin-1beta and interleukin-1ra concentrations by enzyme-linked immunosorbent assay. Pregnancy outcome data were subsequently obtained.

RESULTS

Carriage of intron 2 of the interleukin-1 receptor antagonist allele 2 (IL1RN * 2) was associated with an elevated vaginal pH in black ( P < .001) and white ( P = .005) women, a reduced interleukin-1beta response to anaerobic Gram-negative rods and/or Gardnerella vaginalis ( P < .01), and a decreased rate of spontaneous preterm deliveries (6% versus 18%, P = .02). In black women, IL1RN * 2 carriage was associated with increased anaerobic Gram-negative rods, Mycoplasma, and Peptostreptococci and decreased Lactobacilli colonization.

CONCLUSION

IL1RN * 2 carriage was associated with a blunted proinflammatory interleukin-1beta response to abnormal vaginal flora. This property may decrease susceptibility to infection-related preterm birth.

Relationship between a toll-like receptor-4 gene polymorphism, bacterial vaginosis-related flora and vaginal cytokine responses in pregnant women

OBJECTIVE

The relationship between a single nucleotide polymorphism (TLR4 896 A > G) in the toll-like receptor-4 (TLR4) gene, qualitative and quantitative changes in vaginal micro-flora and vaginal interleukin (IL)-1beta and IL-1 receptor antagonist (IL-1ra) concentrations in pregnant women were evaluated.

STUDY DESIGN

Qualitative and quantitative microbial methods were used to characterize vaginal micro-flora of 238 women at 18-22 weeks gestation. Polymerase chain reaction was used to determine TLR4 genotype. IL-1beta and IL-1ra concentrations in vaginal lavage samples were measured by ELISA.

RESULTS

The TLR4 variant was identified in 10.3% of women. Carriage of this variant was associated with a median increase in vaginal pH (P = 0.05), a greater than 10-fold increase in vaginal Gardnerella vaginalis levels (P < 0.0001) and a 10-fold increase in the vaginal concentration of three species of anaerobic Gram-negative rods, Prevotella, Bacteroides, and Porphyromonas (P = 0.08 ). Colonization with G. vaginalis and/or the anaerobic Gram-negative rods resulted in elevated vaginal IL-1 (P = 0.01) and IL-1ra (P < 0.0002) concentrations in women who were TLR4 896A homozygotes, but not in TLR4 896G carriers.

CONCLUSION

The TLR4 896 A > G polymorphism contributes to inter-individual differences in the vaginal immune defense against G. vaginalis and anaerobic Gram-negative rods.

A disproportionate increase in IL-1beta over IL-1ra in the cervicovaginal secretions of pregnant women with altered vaginal microflora correlates with preterm birth

OBJECTIVE

This purpose of this study was to investigate the association between vaginal microflora, concentrations of interleukin-1beta (IL-1beta), and its natural receptor antagonist (IL-1ra) in the cervicovaginal discharge, and spontaneous preterm birth. Study design Vaginal samples collected at 18 to 22 weeks' gestation from 207 women were analyzed to study qualitative and quantitative microbiologic aspects of vaginal microflora and IL-1beta and IL-1ra concentrations.

RESULTS

Among women colonized with anaerobic Gram-negative rods and/or Gardnerella vaginalis, an elevated IL-1beta concentration, or a diminished IL-1ra:IL-1beta ratio were associated with preterm delivery. A cut-off IL-1ra:IL-1beta ratio of <8632:1 optimally discriminated the subjects with subsequent spontaneous preterm deliveries from subjects who delivered at term, with a sensitivity of 78%, specificity of 51%, positive predictive value of 21%, and negative predictive value of 95%.

CONCLUSION

A disproportionate increase in IL-1beta over IL-1ra in response to vaginal colonization with anaerobic Gram-negative rods and/or G. vaginalis at 18 to 22 weeks' gestation is associated with spontaneous preterm delivery.