HIV-1 infection associated with abnormal vaginal flora morphology and bacterial vaginosis

Periodontal disease and bacterial vaginosis as genetic and environmental markers for the risk of spontaneous preterm labor and preterm birth

OBJECTIVE

The aim of this study was to review the evidence associating periodontal disease, and bacterial vaginosis with preterm birth, and the link with gene polymorphism, as well as the preventions and interventions which might reduce the risk of spontaneous preterm labor and preterm births in women with periodontal disease and/or bacterial vaginosis.

BACKGROUND

Preterm birth accounts for 70% of perinatal mortality, nearly 50% of long term neurological morbidity, and a significant impact on health care costs. There is evidence that spontaneous preterm labor and preterm birth are associated with intrauterine infection due to abnormal genital and/or oral colonization. Periodontal disease and bacterial vaginosis share microbiological similarities, and both conditions are associated with spontaneous preterm labor and preterm birth. In addition, periodontal disease and bacterial vaginosis have been linked through gene polymorphism.

METHODS

A review of the literature using widely accepted scientific search engines in English language.

RESULTS

Studies evaluating antibiotic administration to eradicate periodontal disease and/or bacterial vaginosis responsible organisms, and minimize the risk of preterm births have yielded conflicting results. With respect to bacterial vaginosis, the timing and the choice of antibiotic administration might partly explain the conflicting results. The use of scaling and/or root planning for women with periodontal disease appears to reduce the risk of preterm birth, but routine administration of antibiotics has not demonstrated any impact on preterm birth.

CONCLUSION

Prospective studies evaluating the association of gene polymorphism with preterm birth, and the contribution of periodontal disease and bacterial vaginosis are needed.

Bacterial vaginosis assessed by gram stain and diminished colonization resistance to incident gonococcal, chlamydial, and trichomonal genital infection

BACKGROUND

We sought to assess the relationship between bacterial vaginosis (BV) assessed by Gram stain and incident trichomonal, gonococcal, and/or chlamydial genital infection.

METHODS

This longitudinal study included 3620 nonpregnant women aged 15-44 years who presented for routine care at 12 clinics in Birmingham, Alabama. Participants were assessed quarterly for 1 year. Vaginal smears were categorized by the Nugent Gram stain score (0-3, normal; 4-6, intermediate state; 7-10, BV). Pooled logistic regression was used to estimate the hazard ratios for the comparison of trichomonal, gonococcal, and chlamydial infection incidence in participants by Nugent score at the prior visit. Participants were censored at their first visit with a positive test result for trichomonal, gonococcal, and/or chlamydial infection.

RESULTS

Of the 10,606 eligible visits, 37.96% were classified by BV and 13.3% by positive detection of trichomonal, gonococcal, and/or chlamydial infection. An intermediate state or BV at the prior visit was associated with a 1.5-2-fold increased risk for incident trichomonal, gonococcal, and/or chlamydial infection (adjusted hazard ratio [AHR] for intermediate state, 1.41 [95% confidence interval {CI}, 1.12-1.76]; AHR for BV, 1.73 [95% CI, 1.42-2.11]; P= .058 for trend). Estimates were similar for trichomonal-only, gonococcal-only, and chlamydial-only infection outcomes.

CONCLUSION

BV microbiota as gauged by Gram stain is associated with a significantly elevated risk for acquisition of trichomonal, gonococcal, and/or chlamydial genital infection.

Elucidation of the Molecular Mechanisms of Action of the Natural Antimicrobial Peptide Subtilosin Against the Bacterial Vaginosis-associated Pathogen Gardnerella vaginalis

Subtilosin A is a 35-amino acid long cyclical peptide produced by Bacillus amyloliquefaciens that has potent antimicrobial activity against a variety of human pathogens, including the bacterial vaginosis-related Gardnerella vaginalis. The specific mode of action of subtilosin against G. vaginalis was elucidated by studying its effects on the proton motive force's (PMF) components: transmembrane electric potential (ΔΨ), transmembrane pH gradient (ΔpH), and intracellular ATP levels. The addition of subtilosin to G. vaginalis cells caused an immediate and total depletion of the ΔpH, but had no effect on the ΔΨ. Subtilosin also triggered an instant but partial efflux of intracellular ATP that was twofold higher than that of the positive control bacteriocin, nisin. Taken together, these data suggest that subtilosin inhibits G. vaginalis growth by creating transient pores in the cells' cytoplasmic membrane, leading to an efflux of intracellular ions and ATP and eventually cell death.

Use of cervicovaginal fluid for the identification of biomarkers for pathologies of the female genital tract

Cervicovaginal fluid has an important function in the homeostasis and immunity of the lower female genital tract. Analysis of the cervicovaginal fluid proteome may therefore yield important information about the pathogenesis of numerous gynecological pathologies. Additionally, cervicovaginal fluid has great potential as a source of biomarkers for these conditions.

This review provides a detailed discussion about the human cervicovaginal proteome and the proteomics studies performed to characterize this biological fluid. Furthermore, infection-correlated pathological conditions of the female genital tract are discussed for which cervicovaginal fluid has been used in order to identify potential biomarkers. Recent years, numerous studies have analyzed cervicovaginal fluid samples utilizing antibody-based technologies, such as ELISA or Western blotting, to identify biomarkers for preterm birth, premature preterm rupture of membranes, bacterial vaginosis and cervical cancer. The present article will discuss the importance of proteomic technologies as alternative techniques to gain additional meaningful information about these conditions. In addition, the review focuses on recent proteomic studies on cervicovaginal fluid samples for the identification of potential biomarkers. We conclude that the use of proteomic technology for analysis of human cervicovaginal fluid samples is promising and may lead to the discovery of new biomarkers which can improve disease prevention and therapy development.

Pyrosequencing of the genital microbiotas of HIV-seropositive and -seronegative women reveals Lactobacillus iners as the predominant Lactobacillus Species

The species of vaginal lactobacilli in HIV-seropositive and -seronegative women were determined by 16S gene pyrosequencing. Lactobacillus iners sequences were the predominant lactobacillus sequences in 66% of HIV(+) women and 90% of HIV(-) women. This has implications for resistance of HIV(+) and HIV(-) women to genital colonization by pathogenic organisms.

Determinants of protection among HIV‐exposed seronegative persons: an overview

Both clinical experience and a growing medical literature indicate that some persons who have been exposed to human immunodeficiency virus (HIV) infection remain uninfected. Although in some instances this may represent good fortune, cohorts of uninfected persons have been reported who are considered at high risk for infection. In these cohorts a variety of characteristics have been proposed as mediating protection, but to date only the 32–base pair deletion in the chemokine (C‐C motif) receptor 5 gene, which results in complete failure of cell surface expression of this coreceptor, has been associated with high‐level protection from HIV infection. With this in mind, there are probably many other factors that may individually or in combination provide some level of protection from acquisition of HIV infection. Because some of these factors are probably incompletely protective or inconsistently active, identifying them with confidence will be difficult. Nonetheless, clarifying the determinants of protection against HIV infection is a high priority that will require careful selection of high‐risk uninfected cohorts, who should undergo targeted studies of plausible mediators and broad screening for unexpected determinants of protection.

Easiness of use and validity testing of VS-SENSE device for detection of abnormal vaginal flora and bacterial vaginosis

Accessing vaginal pH is fundamental during gynaecological visit for the detection of abnormal vaginal flora (AVF), but use of pH strips may be time-consuming and difficult to interpret. The aim of this study was to evaluate the VS-SENSE test (Common Sense Ltd, Caesarea, Israel) as a tool for the diagnosis of AVF and its correlation with abnormal pH and bacterial vaginosis (BV). The study population consisted of 45 women with vaginal pH ≥ 4.5 and 45 women with normal pH. Vaginal samples were evaluated by VS-SENSE test, microscopy and microbiologic cultures. Comparing with pH strips results, VS-SENSE test specificity was 97.8% and sensitivity of 91%. All severe cases of BV and aerobic vaginitis (AV) were detected by the test. Only one case with normal pH had an unclear result. Concluding, VS-SENSE test is easy to perform, and it correlates with increased pH, AVF, and the severe cases of BV and AV.

Molecular analysis of the diversity of vaginal microbiota associated with bacterial vaginosis

BACKGROUND

Bacterial vaginosis (BV) is an ecological disorder of the vaginal microbiota that affects millions of women annually, and is associated with numerous adverse health outcomes including pre-term birth and the acquisition of sexually transmitted infections. However, little is known about the overall structure and composition of vaginal microbial communities; most of the earlier studies focused on predominant vaginal bacteria in the process of BV. In the present study, the diversity and richness of vaginal microbiota in 50 BV positive and 50 healthy women from China were investigated using culture-independent PCR-denaturing gradient gel electrophoresis (DGGE) and barcoded 454 pyrosequencing methods, and validated by quantitative PCR.

RESULTS

Our data demonstrated that there was a profound shift in the absolute and relative abundances of bacterial species present in the vagina when comparing populations associated with healthy and diseased conditions. In spite of significant interpersonal variations, the diversity of vaginal microbiota in the two groups could be clearly divided into two clusters. A total of 246,359 high quality pyrosequencing reads was obtained for evaluating bacterial diversity and 24,298 unique sequences represented all phylotypes. The most predominant phyla of bacteria identified in the vagina belonged to Firmicutes, Bacteroidetes, Actinobacteria and Fusobacteria. The higher number of phylotypes in BV positive women over healthy is consistent with the results of previous studies and a large number of low-abundance taxa which were missed in previous studies were revealed. Although no single bacterium could be identified as a specific marker for healthy over diseased conditions, three phyla - Bacteroidetes, Actinobacteria and Fusobacteria, and eight genera including Gardnerella, Atopobium, Megasphaera, Eggerthella, Aerococcus, Leptotrichia/Sneathia, Prevotella and Papillibacter were strongly associated with BV (p < 0.05). These genera are potentially excellent markers and could be used as targets for clinical BV diagnosis by molecular approaches.

CONCLUSIONS

The data presented here have clearly profiled the overall structure of vaginal communities and clearly demonstrated that BV is associated with a dramatic increase in the taxonomic richness and diversity of vaginal microbiota. The study also provides the most comprehensive picture of the vaginal community structure and the bacterial ecosystem, and significantly contributes to the current understanding of the etiology of BV.

Human immunodeficiency virus serodiscordant couples on highly active antiretroviral therapies with undetectable viral load: conception by unprotected sexual intercourse or by assisted reproduction techniques?

Until recently, only assisted reproduction was proposed to serodiscordant couples wishing to conceive. Nevertheless, recent publications have proposed unprotected sexual intercourse, targeting fertile days, for couples where antiretroviral treatment has lowered blood viral load to an undetectable level. Available data and the arguments for and against conception by safe sex versus the use of a strategy of unprotected sexual intercourse targeting fertile days are reviewed and analyzed. Although the rate of transmission of human immunodeficiency virus in serodiscordant couples in precise conditions (such as an undetectable viral load on treatment by highly active antiretroviral therapies and sexual intercourse limited to the fertile days) is very low, not zero, here we stress the various factors which can increase the risk of seroconversion in this particular population. In this context, it seems less cautious to abandon the recommendations of safe sex in serodiscordant couples desiring a child. The recourse to medically assisted procreation is advised, as long as evidence from further studies does not show that unprotected sexual intercourse, targeted to fertile days, does not have unexpected harmful consequences.

In vitro inhibitory activity of human vaginal lactobacilli against pathogenic bacteria associated with bacterial vaginosis in Kenyan women

Lactobacilli have been shown to inhibit in vitro growth of many pathogens and have been used as probiotics to treat a broad range of gastrointestinal and/or vaginal disorders. We sought to determine the in vitro inhibitory potential of lactobacilli of vaginal origin to some bacteria associated with bacterial vaginosis (BV), to characterize the inhibitory substances produced by these lactobacilli and to assess H2O2 production. Vaginal specimens were obtained by swabbing the lateral vaginal walls from 107 women two months following BV treatment. One hundred and fifty eight Lactobacillus spp. were isolated in 82 of the 107 women. Lactobacillus jensenii was the predominant strain isolated among these women (29/158; 18.4%). Among 158 culture supernatants tested for antibacterial activity against BV-associated bacteria, none inhibited the growth of Bacteroides fragilis while 23% (37/158), 28% (45/158) and 29% (46/158) inhibited the growth of Prevotella bivia, Gardnerella vaginalis and Mobiluncus spp. respectively. The lactobacilli produced supernatants with a pH range between 2.62 and 6.71; the highly acidic (pH 2-3.99) supernatants were more inhibitory to the indicator strains. There was significant reduction in the mean zones of inhibition following chemical and physical treatment of the supernatants (p = 0.0025). Acid, bacteriocins and H2O2 demonstrated potential for antagonism of the bacterial pathogens. These substances may augment each other rather that each working independently on the pathogens.

Vaginal self-swab specimen collection in a home-based survey of older women: methods and applications

OBJECTIVES

To describe the methods used for, cooperation with, assays conducted on, and applications of vaginal specimens collected by older women in their homes.

METHODS

Community-residing women (N = 1,550), ages 57-85 years, participated in a nationally representative probability survey. Vaginal self-swab specimen collection and in-home interviews were conducted between 2005 and 2006. Specimens were analyzed for bacterial vaginosis (BV), vaginal candidiasis (VC), high-risk human papillomavirus (HR-HPV), and cytological characteristics. Field methods, consent procedures, the swab protocol, laboratory procedures, and results reporting are described.

RESULTS

One thousand twenty-eight respondents (67.5% weighted) agreed to provide a vaginal specimen; 99.1% were successful. The specimen adequacy rates were BV and VC, 94.1%; HR-HPV, 99.7%; and cytology, 85.5%. The most common recorded reason for nonparticipation was a physical or health problem (38% of nonresponders). Responders were significantly more likely than nonresponders to be younger and more educated, and were more likely to report a recent pelvic examination, menopausal hormone use, and recent sexual activity.

DISCUSSION

Collection of vaginal self-swab specimens from older women in a population-based study is feasible and provides novel data on microenvironmental characteristics of the female genital tract relevant to analyses of gynecologic health, sexual activity and problems, and immune and inflammatory function.

Bacterial vaginosis: a cause of infertility?

Bacterial vaginosis (BV) is a common disorder of the genital tract in women characterized by an alteration of the normal acidic lactobacilli-predominant vaginal ecosystem to a vaginal environment dominated by Gardnerella vaginalis, mycoplasma species and anaerobes, with an increase in pH. The present study evaluated whether BV is associated with reproductive complications in women. BV was screened with a Gram stain of vaginal smear and interpretation was done using the Nugent score. Wet mount and polymerase chain reaction were used to screen other infections. Among 510 enrolled women, 72 (14.1%) had BV. Statistical analysis between the BV negative and positive population revealed a significant association (P = 0.0001) with infertility. In pregnant women, the infection rate was low (P = 0.01). Multiple infections such as Candida, Chlamydia and human papilloma virus were observed in 4.2%, 15.3% and 8.3% of BV-infected women, respectively. Results suggest that BV infection is associated with infertility and its absence leads to pregnancy, emphasizing its screening and treatment.

Probiotics for the treatment of bacterial vaginosis

BACKGROUND

The dominance of lactobacilli in healthy vaginal microbiota and its depletion in bacterial vaginosis (BV) has given rise to the concept of oral or vaginal instillation of probiotic Lactobacillus strains for the management of this condition.

OBJECTIVES

To ascertain the efficacy of probiotics in the treatment of BV.

SEARCH STRATEGY

We searched electronic databases irrespective of publication status or language. These included: Cochrane Central Register of Controlled Trials (CENTRAL), the HIV/AIDS and STD Cochrane Review Groups' specialized registers, the Cochrane Complementary Medicine Field's Register of Controlled Trials, MEDLINE (1966 to 2008), EMBASE (1980 to 2007), ISI science citation index (1955 to 2007), CINAHL (Cumulative Index to Nursing & Allied Health Literature (1982 to 2007).We handsearched of specialty journals, conference proceedings and publications list on the website of the International Scientific Association of Probiotics and Prebiotics (http://www.isapp.net/default.asp).For unpublished studies or ongoing trials, we contacted authors from relevant publications, nutraceutical companies and probiotic-related scientific associations. We searched electronic databases on ongoing clinical trials.

SELECTION CRITERIA

Randomized controlled trials using probiotics for the treatment of women of any age diagnosed with bacterial vaginosis, regardless of diagnostic method used. The probiotic preparation could be single or "cocktail" of strains, any preparation type/dosage/route of administration. Studies comparing probiotics with placebo, probiotics used in conjunction with conventional antibiotics compared with placebo or probiotics alone compared with conventional antibiotics were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

We screened titles and abstracts , obtained full reports of relevant trialsand independently appraised them for eligibility. A data extraction form was used to extract data from the four included studies. For dichotomous outcomes, odds ratios (OR) and 95% confidence intervals (CI) were derived for each study using RevMan (versions 4.2 and 5). We did not perform meta-analysis due to significant differences in the probiotic preparations and trial methodologies.

MAIN RESULTS

Analysis suggests beneficial outcome of microbiological cure with the oral metronidazole/probiotic regimen (OR 0.09 (95% CI 0.03 to 0.26)) and the probiotic/estriol preparation (OR 0.02, (95% CI 0.00 to 0.47)). For the probiotic/estriol preparation, the OR and 95% CI for physician-reported resolution of symptoms was OR 0.04 (95% CI 0.00 to 0.56).

AUTHORS' CONCLUSIONS

The results do not provide sufficient evidence for or against recommending probiotics for the treatment of BV. The metronidazole/probiotic regimen and probiotic/estriol perparation appear promising but well-designed randomized controlled trials with standardized methodologies and larger patient size are needed.

Risk factors associated with low CD4+ lymphocyte count among HIV-positive pregnant women in Nigeria

OBJECTIVE

To determine the risk factors for CD4+ lymphocyte counts of 200 cells/mm(3) or lower in HIV-positive pregnant women in Nigeria.

METHOD

A cross-sectional data analysis from a prospective cohort of 515 HIV-positive women attending a prenatal clinic. Risk of a low CD4+ count was estimated using logistic regression analysis.

RESULTS

CD4+ lymphocyte counts of 200 cells/mm(3) or lower (280+/-182 cells/mm(3)) were recorded in 187 (36.3%) out of 515 HIV-positive pregnant women included in the study. Low CD4+ count was associated with older age (adjusted odds ratio [aOR] 10.71; 95% confidence interval [CI], 1.20-95.53), lack of condom use (aOR, 5.16; 95% CI, 1.12-23.8), history of genital ulcers (aOR, 1.78; 95% CI, 1.12-2.82), and history of vaginal discharge (aOR; 1.62; 1.06-2.48).

CONCLUSIONS

Over 35% of the HIV-positive pregnant women had low CD4+ counts, indicating the need for treatment. The findings underscore the need to integrate prevention of mother-to-child transmission with HIV treatment and care, particularly services for sexually transmitted infections.

Bacterial vaginosis in female facility workers in north-western Tanzania: prevalence and risk factors

OBJECTIVES

To determine prevalence of, and risk factors for, bacterial vaginosis (BV) among herpes simplex virus (HSV) 2 seropositive Tanzanian women at enrollment into a randomised, placebo-controlled trial of HSV suppressive treatment.

METHODS

1305 HSV-2 seropositive women aged 16-35 years working in bars, guesthouses and similar facilities were interviewed, examined and tested for HIV, syphilis, Neisseria gonorrhoeae, Chlamydia trachomatis, BV, candidiasis and trichomoniasis. Factors associated with BV were analysed using logistic regression to estimate odds ratios and 95% confidence intervals.

RESULTS

BV prevalence was 62.9%; prevalence of Nugent score 9-10 was 16.1%. Independent risk factors for BV were work facility type, fewer dependents, increasing alcohol consumption, sex in the last week (adjusted OR 2.03; 95% CI 1.57 to 2.62), using cloths or cotton wool for menstrual hygiene, HIV (adjusted OR 1.41; 95% CI 1.09 to 1.83) and Trichomonas vaginalis infection. There was no association between BV and the frequency or method of vaginal cleansing. However, BV was less prevalent among women who reported inserting substances to dry the vagina for sex (adjusted OR 0.44; 95% CI 0.25 to 0.75).

CONCLUSION

BV was extremely prevalent among our study population of HSV-2 positive female facility workers in North-western Tanzania. Although recent sex was associated with increased BV prevalence, vaginal drying was associated with lower BV prevalence. Further studies of the effects of specific practices on vaginal flora are warranted.

Phase 1 dose-ranging safety trial of Lactobacillus crispatus CTV-05 for the prevention of bacterial vaginosis

BACKGROUND

Bacterial vaginosis is a very common vaginal infection. The lack of endogenous lactobacilli and overgrowth of pathogens facilitate numerous gynecological complications.

METHODS

A phase I dose-ranging safety trial tested the safety, tolerability, and acceptability of Lactobacillus crispatus CTV-05 (LACTIN-V) administered by vaginal applicator. Twelve healthy volunteers were enrolled in 3 blocks of 4 (5 x 10, 1 x 10, and 2 x 10 cfu/dose). Each block was randomized in a 3:1 ratio of active product to placebo. Participants used study product for 5 consecutive days, returned for follow-up on days 7 and 14, and had phone interviews on days 2 and 35.

RESULTS

All 12 participants took 5 doses and completed study follow-up.Overall, 45 adverse events (AEs) occurred, of which 31 (69%) were genitourinary (GU) AEs. GU AEs appeared evenly distributed between the 3 treatment blocks and between LACTIN-V and placebo arms. The most common GU AEs were vaginal discharge in 5 subjects (42%), abdominal pain in 4 subjects (33%), metrorrhagia in 4 subjects (33%), vulvovaginitis in 4 subjects (33%), vaginal candidiasis in 3 subjects (25%), and vaginal odor in 3 subjects (25%). Forty-one (91%) AEs were mild (grade 1) in severity. All 4 moderate AEs (grade 2) were unrelated to product use. No grade 3 or 4 AEs or serious adverse events (SAE) occurred. Laboratory parameters and colposcopy findings were within normal limits or clinically insignificant. The product was well-tolerated and accepted.

CONCLUSION

All 3 dose levels of LACTIN-V appeared to be safe and acceptable in healthy volunteers.

Approach in sexually transmitted diseases

Nowadays, sexually transmitted diseases are one of the most common public health issues. Among its consequences are the possibility of transmission from mother to baby - which may cause miscarriages and congenital disease, male and female infertility, and the increase of HIV infection risk. Therefore, the main goal of these guidelines is to contribute to the improvement of the treatment for sexually transmitted diseases patients by presenting to the medical community how today's science stands on the matter and also what the recommendation for diagnosing and treating a patient are.

An African perspective on mucosal immunity and HIV-1

HIV prevention mandates an understanding of the mechanisms of mucosal immunity with attention to some unique features of the epidemic and mucosal environment in the developing world. An effective vaccine will have to induce mucosal protection against a highly diverse virus, which is equipped with a number of immune evasion strategies. Its development will require assessment of mucosal immune responses, and it will have to protect a mucosal environment where inflammation and altered immune responses are common because of the presence of other mucosal infections, such as sexually transmitted infections and parasites, and where nutritional status may also be compromised. Ideally, not only prevention methods would protect adults but also provide cover against gastrointestinal transmission through maternal milk. Prevention might also be complemented by microbicides and circumcision, two alternative approaches to mucosal protection. It seems unlikely that a single solution will work in all instances and intervention might have to act at multiple levels and be tailored to local circumstances. We review here some of the mucosal events associated with HIV infection that are most relevant in an African setting.

[Bacterial vaginosis]

Bacterial vaginosis is a widely spread health problem with multiple connotations. It has been the subject of many studies and work during decades and it still remains a polemic entity, with contradictory finding. The polymicrobian etiology, unsolved epidemiology, obstetrico-gynecological complications and high recurrence rate following treatment, make this infection a target for researchers. It is not an inflammatory process -yet an immune response exists. In this disorder, vaginal discharge increases, and it is associated with a high risk of developing sexually transmitted diseases.

Can bacterial vaginosis help to find sexually transmitted diseases, especially chlamydial cervicitis?

This study was undertaken to establish reliable factors in order to identify chlamydial cervicitis among suspicious patients. Between January and December 2007, 406 patients who were suspected to have cervicitis due to clinical symptoms, were tested with polymerase chain reaction (PCR) for Chlamydia trachomatis (CT), vaginal pH and Nugent score (NS) in our University hospital and related clinics. During the same period, 67 patients who were diagnosed as having other sexually transmitted diseases (Neisseria gonorrhoeae (NG), Trichomonas vaginalis, Condyloma acuminatum and genital herpes) were also made to participate in this study. Eighty-nine women (22%) were positive for CT PCR. Bacterial vaginosis (BV)-positive women were tested positive for CT PCR (75/288), significantly higher than those without BV (6/66, P = 0.01). In addition, under 20-years old women were positive for CT PCR (24/57), significantly higher than those who were over 30 years old (16/113, P = 0.001). The proportion of patients with high NS (>7) in CT, NG and T. vaginalis cases were 75/89 (84.3%), 22/27 (81.5%) and 11/14 (78.6%), respectively. Whereas the high NS of the C. acuminatum and genital herpes groups were recorded at 7/14 (50%) and 4/12 (33.3%), respectively. Younger women with BV could be at a higher risk for STDs, especially for CT cervicitis.

Vaginal microbiota and the use of probiotics

The human vagina is inhabited by a range of microbes from a pool of over 50 species. Lactobacilli are the most common, particularly in healthy women. The microbiota can change composition rapidly, for reasons that are not fully clear. This can lead to infection or to a state in which organisms with pathogenic potential coexist with other commensals. The most common urogenital infection in premenopausal women is bacterial vaginosis (BV), a condition characterized by a depletion of lactobacilli population and the presence of Gram-negative anaerobes, or in some cases Gram-positive cocci, and aerobic pathogens. Treatment of BV traditionally involves the antibiotics metronidazole or clindamycin, however, the recurrence rate remains high, and this treatment is not designed to restore the lactobacilli. In vitro studies have shown that Lactobacillus strains can disrupt BV and yeast biofilms and inhibit the growth of urogenital pathogens. The use of probiotics to populate the vagina and prevent or treat infection has been considered for some time, but only quite recently have data emerged to show efficacy, including supplementation of antimicrobial treatment to improve cure rates and prevent recurrences.

Gram-positive bacteria enhance HIV-1 susceptibility in Langerhans cells, but not in dendritic cells, via Toll-like receptor activation

Although numerous studies have shown a higher risk of acquiring HIV infection in the presence of other sexually transmitted diseases, the biologic mechanisms responsible for enhanced HIV acquisition are unclear. Because Langerhans cells (LCs) are suspected to be the initial HIV targets after sexual exposure, we studied whether microbial components augment HIV infection in LCs by activating Toll-like receptor (TLR) and nucleotide-binding oligomerization domain (NOD) pattern recognition receptors. We found that TLR1/2 and TLR2/6 agonists dramatically enhanced both HIV susceptibility and replication in immature monocyte-derived LCs, whereas TLR3-5, TLR7-9, and NOD1,2 agonists did not significantly affect HIV infection. The same infection-enhancing effects were observed when LCs were incubated with other related bacterial components as well as with whole Gram(+) bacteria. In resident LCs in human skin, TLR2 agonists also significantly increased HIV susceptibility. By contrast, TLR2 agonists and related bacterial components decreased HIV susceptibility in monocyte-derived dendritic cells (DCs). We found that TLR2 activation of LCs, but not DCs, resulted in a significant down-regulation of APOBEC3G, which is a cellular restriction factor for HIV. Given these data, we hypothesize that ligation of TLR2 by Gram(+) bacterial products may underlie enhanced sexual transmission of HIV that occurs with concomitant bacterial sexually transmitted disease infections.

Comparing anti-HIV, antibacterial, antifungal, micellar, and cytotoxic properties of tricarboxylato dendritic amphiphiles

Three series of homologous dendritic amphiphiles--RCONHC(CH(2)CH(2)COOH)(3), 1(n); ROCONHC(CH(2)CH(2)COOH)(3), 2(n); RNHCONHC(CH(2)CH(2)COOH)(3), 3(n), where R = n-C(n)H(2n+1) and n = 13-22 carbon atoms--were assayed for their potential to serve as antimicrobial components in a topical vaginal formulation. Comparing epithelial cytotoxicities to the ability of these homologues to inhibit HIV, Neisseria gonorrhoeae, and Candida albicans provided a measure of their prophylactic/therapeutic potential. Measurements of the ability to inhibit Lactobacillus plantarum, a beneficial bacterium in the vagina, and critical micelle concentrations (CMCs), an indicator of the potential detergency of these amphiphiles, provided additional assessments of safety. Several amphiphiles from each homologous series had modest anti-HIV activity (EC(50) = 110-130 microM). Amphiphile 2(18) had the best anti-Neisseria activity (MIC =65 microM), while 1(19) and 1(21) had MICs against C. albicans of 16 and 7.7 microM, respectively. Two measures of safety showed promise as all compounds had relatively low cytotoxic activity (EC(50) = 210-940 microM) against epithelial cells and low activity against L. plantarum, 1(n), 2(n), and 3(n) had MICs490, 1300, and 940 microM, respectively. CMCs measured in aqueous triethanolamine and in aqueous potassium hydroxide showed linear dependences on chain length. As expected, the longest chain in each series had the lowest CMC-in triethanolamine: 1(21), 1500 microM; 2(22), 320 microM; 3(22), 340 microM, and in potassium hydroxide: 1(21), 130 microM; 3(22), 40 microM. The CMC in triethanolamine adjusted to pH 7.4 was 400 microM for 1(21) and 3900 microM for 3(16). The promising antifungal activity, low activity against L. plantarum, relatively high CMCs, and modest epithelial cytotoxicity in addition to their anti-Neisseria properties warrant further design studies with dendritic amphiphiles to improve their safety indices to produce suitable candidates for antimicrobial vaginal products.

Effect of mucosal fluid from women with bacterial vaginosis on HIV trans-infection mediated by dendritic cells

Women with bacterial vaginosis (BV) have a higher risk of HIV transmission but the cause of risk is unknown. Dendritic cells (DC) are implicated in transmission of HIV and we previously observed that DC mature when exposed to mucosal fluid from women with BV. We hypothesized that maturation of DC by BV mucosal fluid would enhance DC-mediated trans-infection of HIV. Monocyte-derived DC (MDDC) were treated with mucosal fluid, incubated with HIV(Bal), and HIV trans-infection was evaluated. While LPS-treated MDDC increased HIV(Bal)trans-infection, BV fluid reduced trans-infection. HIV(Bal) DNA levels in MDDC were not affected by BV fluid or LPS but productive infection of MDDC was decreased by LPS and BV fluid. Mucosal fluid from women with BV does not increase MDDC-mediated trans-infection suggesting that BV does not increase HIV susceptibility by increasing DC-mediated trans-infection. However, indirect effects of DC maturation on HIV transmission cannot be ruled out.

Lipopolysaccharide alters the vaginal electrical resistance in cycling and pregnant mice

PROBLEM

Lipopolysaccharide (LPS) has been postulated to exert harmful biologic effects during pregnancy. The objective of present investigation is to measure the vaginal electrical resistance (VER) in LPS-treated normal cycling and pregnant female mice.

METHOD OF STUDY

Minimum dose (MD) of LPS (250 microg/kg body weight) was injected in pregnant female mice through i.p. route on day 0.5 of pregnancy. VER was measured during different phases of reproductive cycle in female mice, which were pre-exposed to LPS and in untreated cycling female mice. VER was also measured in control pregnant female mice (saline-treated mice) through whole pregnancy and LPS-treated female mice in early stages of pregnancy.

RESULTS

Vaginal electrical resistance was significantly higher during proestrous or early estrous stage as compared with any other stages of reproductive cycle in mouse. One peak of VER was observed during peri-implantation period of pregnancy in control female mice. The significant differences in the pattern of VER were found between LPS-treated and control female mice during peri-implantation period of pregnancy, and between cycling female mice, which were pre-exposed to LPS and untreated cycling female mice during proestrus.

CONCLUSION

The presented results demonstrate, for the first time, that LPS exposure during pregnancy may be determined by measuring VER in mothers without any adverse effect on ongoing pregnancy and may help in refining the assisted reproduction techniques.

Bacterial populations in the vaginas of healthy adolescent women

Given that the microbiota of the healthy vagina plays an important role in the maintenance of health, it follows that an understanding of its composition and development may offer insights into the etiology and prevention of disease. In contrast to previous studies, this study exclusively investigated the structure and composition of adolescent vaginal bacterial communities. In this report, the vaginal bacterial communities of 90 menarcheal adolescents, ages 13-18y, were characterized using terminal restriction fragment length polymorphisms (T-RFLP) of 16S rRNA genes. Further characterization involved cluster analysis of the T-RFLP data to identify the number of different kinds of microbial communities found among the adolescents sampled, and phylogenetic analysis of 16S rRNA gene sequences cloned from samples representative of each cluster. We report the identification of four major clusters that accounted for 96.7% of the cohort. In general, these clusters could be divided into those dominated by Lactobacillus spp. and those dominated by a variety of lactic acid producing, anaerobic bacterial types such as Atopobium vaginae and Streptococcus spp. The compositional and structural similarity of the vaginal microbiota of menarcheal adolescents and adults suggests that the vaginal microbiota does not change significantly after the onset of menarche.

Heterosexual risk of HIV-1 infection per sexual act: systematic review and meta-analysis of observational studies

We did a systematic review and meta-analysis of observational studies of the risk of HIV-1 transmission per heterosexual contact. 43 publications comprising 25 different study populations were identified. Pooled female-to-male (0.04% per act [95% CI 0.01-0.14]) and male-to-female (0.08% per act [95% CI 0.06-0.11]) transmission estimates in high-income countries indicated a low risk of infection in the absence of antiretrovirals. Low-income country female-to-male (0.38% per act [95% CI 0.13-1.10]) and male-to-female (0.30% per act [95% CI 0.14-0.63]) estimates in the absence of commercial sex exposure (CSE) were higher. In meta-regression analysis, the infectivity across estimates in the absence of CSE was significantly associated with sex, setting, the interaction between setting and sex, and antenatal HIV prevalence. The pooled receptive anal intercourse estimate was much higher (1.7% per act [95% CI 0.3-8.9]). Estimates for the early and late phases of HIV infection were 9.2 (95% CI 4.5-18.8) and 7.3 (95% CI 4.5-11.9) times larger, respectively, than for the asymptomatic phase. After adjusting for CSE, presence or history of genital ulcers in either couple member increased per-act infectivity 5.3 (95% CI 1.4-19.5) times versus no sexually transmitted infection. Study estimates among non-circumcised men were at least twice those among circumcised men. Low-income country estimates were more heterogeneous than high-income country estimates, which indicates poorer study quality, greater heterogeneity of risk factors, or under-reporting of high-risk behaviour. Efforts are needed to better understand these differences and to quantify infectivity in low-income countries.

Bacterial vaginosis among pregnant women in Burkina Faso

OBJECTIVES

Bacterial vaginosis (bv) is a common cause of abnormal or altered vaginal discharge in women of childbearing age. Its association with obstetric and gynecologic complications and HIV are increasingly recognized. Few population-based surveys of BV have been conducted in Africa. The objective of the study was to examine the role of genital infections including Herpes simplex virus type 2 (HSV-2) and demographic factors on the prevalence of BV among pregnant women in Burkina Faso.

METHODS

Consenting pregnant women from Burkina Faso answered a face-to-face interview on their demographic characteristics. Then, genital and blood swabs were collected and tested for BV and other genital infections. Univariable and multivariable models were used to investigate the risk factors of BV.

RESULTS

Among the 2133 women included in the analyses (over 2284 enrolled), the prevalence of BV was 6.4% [95% confidence interval (CI), 5.5%-7.6%], ranging from 3% to 12% between regions. In multivariable analyses, HSV-2 [odds ratio (OR), 1.64; 95% CI 1.04-2.59) was the only genital infection that remained significantly associated with BV. Other factors related to BV were history of abortion (OR, 1.57; 95% CI, 1.01-2.43) and geographical origin. HIV infection (OR, 1.98; 95% CI, 0.90-5.20) and polygamy (OR, 1.48; 95% CI, 1.00-2.36) tended to be associated with BV without reaching statistical significance.

CONCLUSION

The prevalence of BV among pregnant women was lower than expected, with large geographical disparities. Our data confirm the potential interaction between BV and HSV-2.

Lactocin 160, a Bacteriocin Produced by Vaginal Lactobacillus rhamnosus, Targets Cytoplasmic Membranes of the Vaginal Pathogen, Gardnerella vaginalis

Bacterial vaginosis (BV) is a commonly occurring vaginal infection that is associated with a variety of serious risks related to the reproductive health of women. Conventional antibiotic treatment for this condition is frequently ineffective because the antibiotics tend to inhibit healthy vaginal microflora along with the pathogens. Lactocin 160, a bacteriocin produced by healthy vaginal lactobacilli, is a promising alternative to antibiotics; this compound specifically inhibits the BV-associated vaginal pathogens such as Gardnerella vaginalis and Prevotella bivia without affecting the healthy microflora. This study investigates the molecular mechanism of action for lactocin 160 and reveals that this compound targets the cytoplasmic membrane of G. vaginalis, causing the efflux of ATP molecules and dissipation of the proton motive force.

Does douching increase risk for sexually transmitted infections? A prospective study in high-risk adolescents

OBJECTIVE

The objective of the study was to examine the association between douching and 4 sexually transmitted infections (STIs).

STUDY DESIGN

We followed up 411 high-risk human immunodeficiency virus-infected and uninfected female adolescents aged 12-19 years over a median 3-year period, both by time from study entry/first STI-free visit until an incident STI for participants who never, intermittently, and always douched and also by reported douching at a given STI-free visit and incidence of STI at the next visit, using adjusted Cox proportional hazards models to calculate hazard ratios (HR).

RESULTS

The time to STI was shorter for adolescents who always (HR, 2.1; 95% confidence interval [CI], 1.2-3.4) and intermittently (HR, 1.5; 95% CI, 1.0-2.2) douched, compared with never-douchers. An adjusted hazard for STI was 1.8 times larger for always-douchers (95% CI, 1.1-3.1) and 1.4 times larger for intermittent douchers (95% CI, 0.9-2.0), compared with never-douchers. When classifying by follow-up after an STI-free visit, always-douchers had a shorter STI-free time than never-douchers (HR(adj), 2.1; 95% CI, 1.5-3.1).

CONCLUSION

Counseling to discourage douching may reduce STI risk in adolescents.

The effects of male circumcision on female partners' genital tract symptoms and vaginal infections in a randomized trial in Rakai, Uganda

OBJECTIVE

The objective of the study was to assess effects of male circumcision on female genital symptoms and vaginal infections.

STUDY DESIGN

Human immunodeficiency virus (HIV)-negative men enrolled in a trial were randomized to immediate or delayed circumcision (control arm). Genital symptoms, bacterial vaginosis (BV), and trichomonas were assessed in HIV-negative wives of married participants. Adjusted prevalence risk ratios (adjPRR) and 95% confidence intervals (CIs) were assessed by multivariable log-binomial regression, intent-to-treat analyses.

RESULTS

A total of 783 wives of control and 825 wives of intervention arm men were comparable at enrollment. BV at enrollment was higher in control (38.3%) than intervention arm spouses (30.5%, P = .001). At 1 year follow-up, intervention arm wives reported lower rates of genital ulceration (adjPRR, 0.78; 95% CI, 0.63-0.97), but there were no differences in vaginal discharge or dysuria. The risk of trichomonas was reduced in intervention arm wives (adjPRR, 0.52; 95% CI, 0.05-0.98), as were the risks of any BV (adjPRR, 0.60; 95% CI, 0.38-0.94) and severe BV (prevalence risk ratios, 0.39; 95% CI, 0.24-0.64).

CONCLUSION

Male circumcision reduces the risk of ulceration, trichomonas, and BV in female partners.

Guidelines for reducing the risk of viral transmission during fertility treatment

These guidelines provide strategies, based on scientific principles and clinical experience, for reducing the risk of virus transmission in couples seeking treatment for infertility.

Organisms associated with bacterial vaginosis in Nigerian women as determined by PCR-DGGE and 16S rRNA gene sequence

BACKGROUND

Bacterial vaginosis (BV) is a condition with diverse etiology. This condition predisposes women to increased susceptibility to sexually transmitted diseases, including human immunodeficiency virus (HIV) infections and preterm birth. The diagnostic methods currently adopted in the evaluation of patient samples for BV are arguably Amsel criteria, and Nugent score that require microscopy and expert interpretation. These two methods are still subjective.

OBJECTIVE

The objective of this study was to determine the organisms present in the vagina of 34 HIV negative Nigerian women diagnosed as having bacterial vaginosis by using molecular techniques.

METHODS

The vaginal samples were subjected to DNA extraction, and amplified with eubacterial primers via PCR. The PCR products were separated using denaturing gradient gel electrophoresis (DGGE). Bands were excised, re-amplified, purified and sequenced. Sequence identification was performed using the BLAST algorithm and Genbank data base.

RESULTS

Mycoplasma hominis (12/34; 35%) was the most common isolate and 9 (26%) contained one of two clones of an unusual Rainbow Trout intestinal bacterium, while unculturable Streptococcus sp, and other bacteria made up the remaining isolates.

CONCLUSIONS

The findings indicate further diversity in the etiological agents associated with BV, and raise the question as to whether diagnosis and management of this condition needs to be re-evaluated in countries like Nigeria. There is some controversy over the clinical importance of BV, as it was once regarded as a disease caused by Gardnerella and presenting as an odourous discharge condition, but is now diagnosed without necessarily the presence of these organisms or signs. With the incidence of BV aligned to an increased risk of HIV in a country ravaged by this virus, the effective eradication of BV can only be achieved if appropriate therapies are delivered.

Vaginal microbicides and the prevention of HIV transmission

Worldwide, nearly half of all individuals living with HIV are now women, who acquire the virus largely by heterosexual exposure. With an HIV vaccine likely to be years away, topical microbicide formulations applied vaginally or rectally are being investigated as another strategy for HIV prevention. A review of preclinical and clinical research on the development of microbicides formulated to prevent vaginal HIV transmission yielded 118 studies: 73 preclinical and 45 clinical. Preclinical research included in-vitro assays and cervical explant models, as well as animal models. Clinical research included phase I and II/IIb safety studies, and phase III efficacy studies. Whereas most phase I and phase II clinical trials have found microbicide compounds to be safe and well tolerated, phase III trials completed to date have not demonstrated efficacy in preventing HIV transmission. Topical microbicides are grouped into five classes of agents, based on where they disrupt the pathway of sexual transmission of HIV. These classes include surfactants/membrane disruptors, vaginal milieu protectors, viral entry inhibitors, reverse transcriptase inhibitors, and a fifth group whose mechanism is unknown. The trajectory of microbicide development has been toward agents that block more specific virus-host cell interactions. Microbicide clinical trials face scientifically and ethically complex issues, such as the choice of placebo gel, the potential for viral resistance, and the inclusion of HIV-infected participants. Assessment of combination agents will most likely advance this field of research.

Cytologically diagnosed Gardnerella vaginalis infection and cervical (pre)neoplasia as established in population-based cervical screening

OBJECTIVE

Cervical inflammation has been proposed as a cofactor in the development of cervical cancer. The purpose of this study was to document the prevalence of cervical (pre)neoplastic changes in asymptomatic women with a cytologically diagnosed Gardnerella vaginalis infection.

STUDY DESIGN

Data were collected from 800,498 Dutch asymptomatic women, participating in the Dutch national screening program. Prevalences of (pre)neoplasia were calculated for G vaginalis smears using a healthy flora as reference.

RESULTS

The prevalence of G vaginalis infection was 0.6 per thousand. The odds ratio for (pre)neoplasia was significantly higher in smears with G vaginalis infection compared with smears of women with a healthy vaginal flora (odds ratio, 10.3; 95% confidence interval, 6.6-16.1).

CONCLUSION

Cytologically diagnosed G vaginalis smears show a strong covariation with the presence of cervical (pre)neoplasia. Future research should therefore focus on the exact causal relation between cytologic G vaginalis infection and the presence of (pre)neoplastic changes of the cervix.

The effects of male circumcision on female partners' genital tract symptoms and vaginal infections in a randomized trial in Rakai, Uganda

OBJECTIVE

The objective of the study was to assess effects of male circumcision on female genital symptoms and vaginal infections.

STUDY DESIGN

Human immunodeficiency virus (HIV)-negative men enrolled in a trial were randomized to immediate or delayed circumcision (control arm). Genital symptoms, bacterial vaginosis (BV), and trichomonas were assessed in HIV-negative wives of married participants. Adjusted prevalence risk ratios (adjPRR) and 95% confidence intervals (CIs) were assessed by multivariable log-binomial regression, intent-to-treat analyses.

RESULTS

A total of 783 wives of control and 825 wives of intervention arm men were comparable at enrollment. BV at enrollment was higher in control (38.3%) than intervention arm spouses (30.5%, P = .001). At 1 year follow-up, intervention arm wives reported lower rates of genital ulceration (adjPRR, 0.78; 95% CI, 0.63-0.97), but there were no differences in vaginal discharge or dysuria. The risk of trichomonas was reduced in intervention arm wives (adjPRR, 0.52; 95% CI, 0.05-0.98), as were the risks of any BV (adjPRR, 0.60; 95% CI, 0.38-0.94) and severe BV (prevalence risk ratios, 0.39; 95% CI, 0.24-0.64).

CONCLUSION

Male circumcision reduces the risk of ulceration, trichomonas, and BV in female partners.

Application of ecological network theory to the human microbiome

In healthy humans, many microbial consortia constitute rich ecosystems with dozens to hundreds of species, finely tuned to functions relevant to human health. Medical interventions, lifestyle changes, and the normal rhythms of life sometimes upset the balance in microbial ecosystems, facilitating pathogen invasions or causing other clinically relevant problems. Some diseases, such as bacterial vaginosis, have exactly this sort of community etiology. Mathematical network theory is ideal for studying the ecological networks of interacting species that comprise the human microbiome. Theoretical networks require little consortia specific data to provide insight into both normal and disturbed microbial community functions, but it is easy to incorporate additional empirical data as it becomes available. We argue that understanding some diseases, such as bacterial vaginosis, requires a shift of focus from individual bacteria to (mathematical) networks of interacting populations, and that known emergent properties of these networks will provide insights that would be otherwise elusive.

Comparison of the diversity of the vaginal microbiota in HIV-infected and HIV-uninfected women with or without bacterial vaginosis

BACKGROUND

Whether human immunodeficiency virus (HIV) infection is associated with a change in the diversity of genital microbiota in women was investigated.

METHODS

Amplicon length heterogeneity polymerase chain reaction (LH-PCR) analysis and pyrosequencing of the 16S ribosomal RNA gene were used to analyze the diversity of the microbiota in HIV-positive (HIV(+)) and HIV-negative (HIV(-)) women with or without bacterial vaginosis (BV).

RESULTS

LH-PCR analysis revealed significantly more microbiota diversity in BV-positive (BV(+)) women than in BV-negative (BV(-)) women, but no significant difference was noted between HIV(+) women and HIV(-) women. Pyrosequencing revealed that Lactobacillus organisms constituted a median of 96% of the bacteria in BV(-) women. BV(+) women had a significantly higher number of taxa found at > or =1% of the total genital microbiota (median, 11 taxa). Common taxa in BV(+) women were Prevotella, Megasphaera, Gardnerella, Coriobacterineae, Lachnospira, and Sneathia. There was a trend (P = .07) toward the presence of a higher number of taxa in HIV(+)BV(+) women than in HIV(-)BV(+) women. Propionibacterineae, Citrobacter, and Anaerococcus were the taxa found only in HIV(+) women (P < .05).

CONCLUSIONS

The present study demonstrated that both LH-PCR analysis and pyrosequencing differentiated microbiota in BV(+) women from that in BV(-) women and that pyrosequencing indicated a trend toward increased diversity in BV(+)HIV(+) women, suggesting that HIV infection is associated with changes in the diversity of genital microbiota.

Spermicidal activity of the safe natural antimicrobial peptide subtilosin

Bacterial vaginosis (BV), a condition affecting millions of women each year, is primarily caused by the gram-variable organism Gardnerella vaginalis. A number of organisms associated with BV cases have been reported to develop multidrug resistance, leading to the need for alternative therapies. Previously, we reported the antimicrobial peptide subtilosin has proven antimicrobial activity against G. vaginalis, but not against the tested healthy vaginal microbiota of lactobacilli. After conducting tissue sensitivity assays using an ectocervical tissue model, we determined that human cells remained viable after prolonged exposures to partially-purified subtilosin, indicating the compound is safe for human use. Subtilosin was shown to eliminate the motility and forward progression of human spermatozoa in a dose-dependent manner, and can therefore be considered a general spermicidal agent. These results suggest subtilosin would be a valuable component in topical personal care products aimed at contraception and BV prophylaxis and treatment.

Bacterial vaginosis and HIV acquisition: a meta-analysis of published studies

OBJECTIVES

To assess and summarize the published literature on the extent to which bacterial vaginosis may increase the risk of HIV acquisition.

DESIGN

Meta-analysis of published studies.

METHODS

Medline and other electronic databases were systematically searched for eligible publications. The association between bacterial vaginosis and incident HIV was separately analyzed from that between bacterial vaginosis and prevalent HIV. The latter was further analyzed, stratified by bacterial vaginosis diagnostic method, HIV risk profile of the study population, and whether or not adjusted estimates were presented.

RESULTS

Twenty-three eligible publications were identified, including a total of 30,739 women. Bacterial vaginosis was associated with an increased risk of HIV acquisition in HIV-incidence studies (relative risk = 1.6, 95% confidence interval: 1.2, 2.1). All but one of 21 HIV-prevalence studies reported estimates above the null. The latter results were heterogeneous and showed some evidence of funnel plot asymmetry, precluding the estimation of a single summary measure. The association between bacterial vaginosis and HIV in prevalence studies appeared stronger for women without high-risk sexual behavior.

CONCLUSION

Bacterial vaginosis was consistently associated with an increased risk of HIV infection. High bacterial vaginosis prevalence may result in a high number of HIV infections being attributable to bacterial vaginosis. More prospective studies are needed to accurately evaluate the role of bacterial vaginosis in HIV acquisition in low-risk versus high-risk women. Furthermore, randomized clinical trials may be worth considering to determine the effect of bacterial vaginosis control measures on HIV acquisition.

Probiotics: potential to prevent HIV and sexually transmitted infections in women

Women are at significant risk of human immunodeficiency virus (HIV) and sexually transmitted infection (STI) acquisition with the genital mucosa serving as the main portal of infection. Exogenously supplied lactobacillus used as a probiotic may prove a cost-effective, female-initiated method to prevent HIV and STI infection in women. A probiotic may act indirectly through treating and preventing recurrent bacterial vaginosis or directly by secreting endogenous (e.g., hydrogen peroxide) and exogenous substances that block HIV and STI transmission. This review summarizes the preclinical and clinical studies that have been conducted so far to test probiotic bacteria for these purposes. Although significant progress has been made in this field, more fundamental research is required to better understand vaginal ecology to maximize probiotic formulations. Once identified, a suitable product will require testing in a well-designed, randomized, placebo-controlled trial to measure its effectiveness in augmenting antibiotic treatment to prevent bacterial vaginosis. If results from such a trial demonstrate efficacy, future studies should be designed to determine whether a probiotic can significantly lower the risk for HIV and STIs in at-risk female populations.

A longitudinal study of vaginal douching and bacterial vaginosis--a marginal structural modeling analysis

The etiology of bacterial vaginosis is unknown, and there are no long-term therapies for preventing this frequently recurring condition. Vaginal douching has been reported to be associated with bacterial vaginosis in observational studies. However, this association may be due to confounding by indication--that is, confounding by women douching in response to vaginal symptoms associated with bacterial vaginosis. The authors used marginal structural modeling to estimate the causal effect of douching on bacterial vaginosis risk while controlling for this confounding effect. In 1999-2002, nonpregnant women (n = 3,620) were recruited into a prospective study when they visited one of 12 public health clinics in Birmingham, Alabama, for routine care. Participants were assessed quarterly for 1 year. Bacterial vaginosis was based on a Nugent's Gram stain score of 7 or higher. Thirty-two percent of participants douched in every study interval, and 43.0% never douched. Of the 12,349 study visits, 40.2% were classified as involving bacterial vaginosis. The relative risk for regular douching as compared with no douching was 1.21 (95% confidence interval: 1.08, 1.38). These findings indicate that douching confers increased risk of disruption of vaginal flora. In the absence of a large randomized trial, these findings provide the best evidence to date for a risk of bacterial vaginosis associated with douching.

Diversity of human vaginal bacterial communities and associations with clinically defined bacterial vaginosis

Bacterial vaginosis (BV) is a common syndrome associated with numerous adverse health outcomes in women. Despite its medical importance, the etiology and microbial ecology of BV remain poorly understood. We used broad-range PCR to census the community structure of the healthy and BV-affected vaginal microbial ecosystems and synthesized current publicly available bacterial 16S rRNA gene sequence data from this environment. The community of vaginal bacteria detected in subjects with BV was much more taxon rich and diverse than in subjects without BV. At a 97% sequence similarity cutoff, the number of operational taxonomic units (OTUs) per patient in 28 subjects with BV was nearly three times greater than in 13 subjects without BV: 14.8 +/- 0.7 versus 5.2 +/- 0.75 (mean +/- standard error). OTU-based analyses revealed previously hidden diversity for many vaginal bacteria that are currently poorly represented in GenBank. Our sequencing efforts yielded many novel phylotypes (123 of our sequences represented 38 OTUs not previously found in the vaginal ecosystem), including several novel BV-associated OTUs, such as those belonging to the Prevotella species complex, which remain severely underrepresented in the current NCBI database. Community composition was highly variable among subjects at a fine taxonomic scale, but at the phylum level, Actinobacteria and Bacteroidetes were strongly associated with BV. Our data describe a previously unrecognized extent of bacterial diversity in the vaginal ecosystem. The human vagina hosts many bacteria that are only distantly related to known species, and subjects with BV harbor particularly taxon-rich and diverse bacterial communities.

Rapid detection of Atopobium vaginae and association with organisms implicated in bacterial vaginosis

Atopobium vaginae, a fastidious, anaerobic, Gram-positive cocci-shaped bacterium that generates large quantities of lactic acid, is associated with bacterial vaginosis (BV). Published nucleic acid amplification tests for identifying A. vaginae are directed toward the 16S ribosomal DNA with suboptimal specificity and require isolation of the organism. Here, sequencing of an A. vaginae genomic library has led to the development of a highly specific and sensitive real-time PCR test for detection of A. vaginae directly from gynecological cervicovaginal swab samples. The real-time PCR did not cross-react with DNA extracted from other members of the Atopobium genus, species with closely related 16S ribosomal DNA, and a panel of 51 other human pathogens. The DNA extraction and PCR assembly were amenable to automation using Corbett Robotics X-tractor Gene and CAS-4200N liquid handling systems. The real-time PCR was used to analyze 96 cervicovaginal swab samples submitted to our clinical laboratory for detection of organisms associated with BV. Of those samples, 28 were positive for A. vaginae. Of the 28 positive samples, 23 were concomitant with Gardnerella vaginalis detection. These results suggest that further clinical study of the relationship of A. vaginae with G. vaginalis and the development of BV should be performed.