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

Antimicrobial polypeptides are key anti-HIV-1 effector molecules of cervicovaginal host defense

Mucosal surfaces of the cervix and vagina are portals for heterosexual transmission of human immunodeficiency virus type 1 (HIV-1) and, therefore, play a fundamental role in the pathogenesis of primary infection. Cationic antimicrobial polypeptides including defensins are the principal effector molecules of mucosal innate immunity against microbes and viruses such as HIV. In cervicovaginal secretions, antimicrobial polypeptides constitute the majority of the intrinsic anti-HIV-1 activity, synergism between cationic polypeptides is complex, and full anti-HIV-1 activity involves the complete complement of cationic polypeptides. Periods in which cationic antimicrobial polypeptide expression is reduced are likely associated with increased susceptibility to HIV-1 infection. This review provides an overview of the role of cationic antimicrobial polypeptides in innate cervicovaginal anti-HIV-1 host defense, and discusses how hormones and bacterial infections can regulate their expression. Emphasis is placed on the theta-defensin (retrocyclin) class of anti-HIV-1 peptides and their potential for development as topical microbicides to prevent HIV-1 transmission.

Atopobium vaginae triggers an innate immune response in an in vitro model of bacterial vaginosis

Bacterial vaginosis is the most common vaginal disorder among women of reproductive age. The pathogenesis of bacterial vaginosis is poorly understood, but is defined by a transition in the vaginal flora from the predominant Lactobacillus species to other bacterial species such as Atopobium vaginae and Gardnerella vaginalis. This change is associated with an increase in vaginal cytokine secretion. We hypothesize that vaginal epithelial cells respond to bacterial vaginosis-associated bacteria by triggering an innate immune response. We observed that vaginal epithelial cells secreted interleukin-6 and interleukin-8 in response to Atopobium vaginae and Gardnerella vaginalis, but not to Lactobacillus crispatus. Atopobium vaginae induced increased levels of interleukin-6 and interleukin-8 transcripts, as well as increased transcripts for the antimicrobial peptide beta-defensin 4. This innate immune response required live bacteria capable of protein synthesis in direct contact with vaginal epithelial cells. The response of vaginal epithelial cells was mediated by Toll-like receptor 2, required the adaptor protein MyD88, and involved activation of the NFkappaB signaling pathway. These results suggest that Atopobium vaginae stimulates an innate immune response from vaginal epithelial cells, leading to localized cytokine and defensin production, and possibly contributes to the pathogenesis of bacterial vaginosis.

TLR2-mediated cell stimulation in bacterial vaginosis

Bacterial vaginosis (BV) is associated with preterm labor, pelvic inflammatory disease (PID) and increased HIV acquisition, although the pathways that mediate these pathological effects have not been elucidated. To determine the presence of Toll-like receptor (TLR)-ligands and their specificity in BV, genital tract fluids were collected from women with and without BV by cervicovaginal lavage (CVL). The CVL samples were evaluated for their ability to stimulate secretion of proinflammatory cytokines and to activate NFkappaB and the HIV long terminal repeat (LTR), indicators of TLR activation, in human monocytic cells. Stimulation with BV CVLs induced higher levels of IL-8 and TNFalpha secretion, as well as higher levels of HIV LTR and NFkappaB activation, than CVLs from women with normal healthy bacterial flora. To identify which TLRs were important in BV, 293 cells expressing specific TLRs were exposed to CVL samples. BV CVLs induced higher IL-8 secretion by cells expressing TLR2 than CVLs from women without BV. Surprisingly, BV CVLs did not stimulate cells expressing TLR4/MD2, although these cells responded to purified lipopolysaccharide (LPS), a TLR4 ligand. BV CVLs, in cells expressing TLR2, also activated the HIV LTR. Thus, these studies show that soluble factor(s) present in the lower genital tract of women with BV activate cells via TLR2, identifying a pathway through which BV may mediate adverse effects.

Quantitative determination by real-time PCR of four vaginal Lactobacillus species, Gardnerella vaginalis and Atopobium vaginae indicates an inverse relationship between L. gasseri and L. iners

Background

Most studies of the vaginal microflora have been based on culture or on qualitative molecular techniques. Here we applied existing real-time PCR formats for Lactobacillus crispatus, L. gasseri and Gardnerella vaginalis and developed new formats for Atopobium vaginae, L. iners and L. jensenii to obtain a quantitative non culture-based determination of these species in 71 vaginal samples from 32 pregnant and 28 non-pregnant women aged between 18 and 45 years.

Results

The 71 vaginal microflora samples of these women were categorized, using the Ison and Hay criteria, as refined by Verhelst et al. (2005), as follows: grade Ia: 8 samples, grade Iab: 10, grade Ib: 13, grade I-like: 10, grade II: 11, grade III: 12 and grade IV: 7.

L. crispatus was found in all but 5 samples and was the most frequent Lactobacillus species detected. A significantly lower concentration of L. crispatus was found in grades II (p < 0.0001) and III (p = 0.002) compared to grade I. L. jensenii was found in all grades but showed higher concentration in grade Iab than in grade Ia (p = 0.024). A. vaginae and G. vaginalis were present in high concentrations in grade III, with log₁₀ median concentrations (log₁₀ MC), respectively of 9.0 and 9.2 cells/ml. Twenty (38.5%) of the 52 G. vaginalis positive samples were also positive for A. vaginae. In grade II we found almost no L. iners (log₁₀ MC: 0/ml) but a high concentration of L. gasseri (log₁₀ MC: 8.7/ml). By contrast, in grade III we found a high concentration of L. iners (log₁₀ MC: 8.3/ml) and a low concentration of L. gasseri (log₁₀ MC: 0/ml). These results show a negative association between L. gasseri and L. iners (r = -0.397, p = 0.001) and between L. gasseri and A. vaginae (r = -0.408, p < 0.0001).

Conclusion

In our study we found a clear negative association between L. iners and L. gasseri and between A. vaginae and L. gasseri. Our results do not provide support for the generally held proposition that grade II is an intermediate stage between grades I and III, because L. gasseri, abundant in grade II is not predominant in grade III, whereas L. iners, abundant in grade III is present only in low numbers in grade II samples.

Personal and community benefits and harms of research: views from Rakai, Uganda

OBJECTIVES

To assess what individuals in low-income countries perceive as benefits and harms of population-based HIV/STD research.

DESIGN

A total of 811 research participants, research decliners, and community opinion leaders in the Rakai District, Uganda were surveyed. Types of personal and community benefits and harms, as well as rates of reporting great personal and community benefit were assessed.

METHODS

Using logistic regression, demographic characteristics, participant and opinion leader status, use of Rakai Health Sciences Program (RHSP) services, and perceived research effects were entered as predictors of reported great personal and great community benefit.

RESULTS

Most respondents thought that RHSP research was of great personal (85%) and community (88%) benefit. The perception that the RHSP was a great personal benefit was correlated with female sex, post-secondary education, frequent use of RHSP-sponsored medical services, health knowledge gains, and increased hope for future health improvements. Persons of non-Baganda ethnicity and 30-39 year-olds were less likely to believe research was personally beneficial. Regarding research as a great community benefit was associated with reported health knowledge gains, greater hope for Rakai residents' future health, and local economic benefit. Decliners were the most likely to report a personal harm, while community opinion leaders identified community harms at the highest rates.

CONCLUSIONS

The majority of Rakai residents report that HIV/STD research has enhanced their own and their communities' welfare. Different factors were associated with the belief that research is a personal versus community benefit. Variations in participant, decliner, and community opinion leader perceptions highlight inadequacies of current community consultation mechanisms.

Bacterial vaginosis and human immunodeficiency virus infection

Epidemiologic studies indicate that bacterial vaginosis (BV), a common alteration of lower genital tract flora in women, is associated with increased susceptibility to HIV infection. Other recent studies show that HIV is detected more frequently and at higher levels in the lower genital tract of HIV-seropositive women with BV. In vitro studies show that genital tract secretions from women with BV or flora associated with BV induce HIV expression in infected cells. The increased HIV expression appears to be due at least in part to activation through Toll-like receptors (TLR), specifically TLR2. Further research is needed to elucidate how BV contributes to HIV acquisition and transmission.

Dendritic cell activation and maturation induced by mucosal fluid from women with bacterial vaginosis

Dendritic cells (DC) at mucosal surfaces mature when exposed to "danger" signals such as LPS. Bacterial vaginosis (BV) is a prevalent alteration of the vaginal bacterial flora associated with preterm childbirth and increased risk for HIV acquisition. We examined the effect of mucosal fluid from women with BV or healthy flora on DC function. IL-12, IL-23 and p40 production by monocyte-derived dendritic cells (MDDC) were all induced by BV samples. Activation/maturation markers HLA-DR, CD40 and CD83 on MDDC incubated with BV CVL were also induced. BV CVL also decreased the endocytic ability of MDDC and increased proliferation of T cells in allogeneic MLR. Plasmacytoid dendritic cell (pDC) CD86 expression was induced by BV CVL. Healthy flora CVL had little effect in any of the tests. This study suggests that BV, but not healthy flora, affects local dendritic cell function in vivo suggesting a mechanism through which BV affects mucosal immunity.

Antiretroviral drug exposure in the female genital tract: implications for oral pre- and post-exposure prophylaxis

OBJECTIVES

To describe first dose and steady state antiretroviral drug exposure in the female genital tract.

DESIGN

Non-blinded, single center, open-label pharmacokinetic study in HIV-infected women.

METHOD

Twenty-seven women initiating combination antiretroviral therapy underwent comprehensive blood plasma and cervicovaginal fluid sampling for drug concentrations during the first dose of antiretroviral therapy and at steady-state. Drug concentrations were measured by validated HPLC/UV or HPLC-MS/MS methods. Pharmacokinetic parameters were estimated for 11 drugs by non-compartmental analysis. Descriptive statistics and 95% confidence intervals were generated using Intercooled STATA Release 8.0 (Stata Corporation, College Station, Texas, USA).

RESULTS

For all antiretroviral drugs, genital tract concentrations were detected rapidly after the first dose. Drugs were stratified according to the genital tract concentrations achieved relative to blood plasma. Median rank order of highest to lowest genital tract concentrations relative to blood plasma at steady state were: lamivudine (concentrations achieved were 411% greater than blood plasma), emtricitabine (395%), zidovudine (235%) tenofovir (75%), ritonavir (26%), didanosine (21%), atazanavir (18%), lopinavir (8%), abacavir (8%), stavudine (5%), and efavirenz (0.4%).

CONCLUSIONS

This is the first study to comprehensively evaluate antiretroviral drug exposure in the female genital tract. These findings support the use of lamivudine, zidovudine, tenofovir and emtricitabine as excellent pre-exposure/post-exposure prophylaxis (PrEP/PEP) candidates. Atazanavir and lopinavir might be useful agents for these applications due to favorable therapeutic indices, despite lower genital tract concentrations. Agents such as stavudine, abacavir, and efavirenz that achieve genital tract exposures less than 10% of blood plasma are less attractive PrEP/PEP candidates.

Probiotics for the treatment of women with bacterial vaginosis

This review considers whether probiotics are effective agents for the treatment and/or prevention of bacterial vaginosis (BV). There seems to be an association between the absence of, or low concentrations of, vaginal lactobacilli and the development of BV. Many studies have suggested that the presence of H2O2-producing vaginal lactobacilli may protect against BV, although some studies do not support this hypothesis. In-vitro studies have suggested that certain specific strains of lactobacilli are able to inhibit the adherence of Gardnerella vaginalis to the vaginal epithelium and/or produce H2O2, lactic acid and/or bacteriocins, which inhibit the growth of bacteria causing BV. Clinical trials showed that intra-vaginal administration of Lactobacillus acidophilus for 6-12 days, or oral administration of L. acidophilus or Lactobacillus rhamnosus GR-1 and Lactobacillus fermentum RC-14 for 2 months, resulted in the cure of BV (defined as a 0-1 positive score according to Amsel's criteria), and/or reduced the recurrences of BV, and/or caused an increase in vaginal lactobacilli and restoration of a normal vaginal microbiota, significantly more frequently than did a placebo, acetic acid or no treatment. However, several trials have found no significant difference in the cure rate of BV and in the number of vaginal lactobacilli after intra-vaginal instillation of lactobacilli when compared with the effect of a placebo or oestrogen. Thus, although the available results concerning the effectiveness of the administration of lactobacilli for the treatment of BV are mostly positive, it cannot yet be concluded definitively that probiotics are useful for this purpose.

Prevalence of bacterial vaginosis among young women in low-income populations of coastal Peru

The goal of this study was to determine the prevalence of bacterial vaginosis (BV) in Peruvian women from socioeconomically deprived populations and to determine the association between BV and risk factors for sexually transmitted diseases (STDs). Women were administered an epidemiologic survey to determine sexual risk behaviour and they provided biological samples to test for BV and STDs. The prevalence of BV was high (27%) and was significantly associated with having a bacterial STD or trichomoniasis. Age, marital status, and a history of sex work, but not of sexual experience, frequency of intercourse, and unprotected intercourse, were associated with BV. As BV may be a marker for STDs, screening for STDs should be performed in individuals with BV to promote early detection and treatment of co-infecting sexually transmitted pathogens.

Cervicovaginal levels of lactoferrin, secretory leukocyte protease inhibitor, and RANTES and the effects of coexisting vaginoses in human immunodeficiency virus (HIV)-seronegative women with a high risk of heterosexual acquisition of HIV infection

Innate immune factors in mucosal secretions may influence human immunodeficiency virus type 1 (HIV-1) transmission. This study examined the levels of three such factors, genital tract lactoferrin [Lf], secretory leukocyte protease inhibitor [SLPI], and RANTES, in women at risk for acquiring HIV infection, as well as cofactors that may be associated with their presence. Women at high risk for HIV infection meeting established criteria (n = 62) and low-risk controls (n = 33) underwent cervicovaginal lavage (CVL), and the CVL fluid samples were assayed for Lf and SLPI. Subsets of 26 and 10 samples, respectively, were assayed for RANTES. Coexisting sexually transmitted infections and vaginoses were also assessed, and detailed behavioral information was collected. Lf levels were higher in high-risk (mean, 204 ng/ml) versus low-risk (mean, 160 ng/ml, P = 0.007) women, but SLPI levels did not differ, and RANTES levels were higher in only the highest-risk subset. Lf was positively associated only with the presence of leukocytes in the CVL fluid (P < 0.0001). SLPI levels were lower in women with bacterial vaginosis [BV] than in those without BV (P = 0.04). Treatment of BV reduced RANTES levels (P = 0.05). The influence, if any, of these three cofactors on HIV transmission in women cannot be determined from this study. The higher Lf concentrations observed in high-risk women were strongly associated with the presence of leukocytes, suggesting a leukocyte source and consistent with greater genital tract inflammation in the high-risk group. Reduced SLPI levels during BV infection are consistent with an increased risk of HIV infection, which has been associated with BV. However, the increased RANTES levels in a higher-risk subset of high-risk women were reduced after BV treatment.

Purification and characterization of enterocin 62-6, a two-peptide bacteriocin produced by a vaginal strain of Enterococcus faecium: Potential significance in bacterial vaginosis

A bacteriocin produced by a vaginal isolate of Enterococcus faecium strain 62-6, designated enterocin 62-6, was characterized following purification and DNA sequence analysis and compared to previously described bacteriocins. Enterocin 62-6 was isolated from brain heart infusion (BHI) culture supernatants using ammonium sulfate precipitation followed by elution from a Sepharose cation exchange column using a continuous salt gradient (0.1-0.7 M NaCl). SDS-PAGE of an active column fraction resulted in an electrophoretically pure protein, which corresponded to the growth inhibition of the sensitive Lactobacillus indicator strain in the gel overlay assay. Purified enterocin 62-6 was shown to be heat- and pH-stable, and sensitive to the proteolytic enzymes alpha-chymotrypsin and pepsin. Results from mass spectrometry suggested that it comprised two peptides of 5206 and 5219+/-1 Da, which was confirmed by DNA sequence analysis. The characteristics of enterocin 62-6 as a small, heat- and pH-stable, cationic, hydrophobic, two-peptide, plasmid-borne bacteriocin, with an inhibitory spectrum against a broad range of Gram-positive but not Gram-negative bacteria, were consistent with its classification as a class IIc bacteriocin. Furthermore, its wide spectrum of growth inhibitory activity against Gram-positive bacteria of vaginal origin including lactobacilli, and stability under the acidic conditions of the vagina, are consistent with our hypothesis that it could have potential significance in disrupting the ecology of the vaginal tract and pave the way for the establishment of the abnormal microbiota associated with the vaginal syndrome bacterial vaginosis. This is the first class IIc bacteriocin produced by a strain of E. faecium of vaginal origin to be characterized.

A randomized trial of metronidazole in asymptomatic bacterial vaginosis to prevent the acquisition of sexually transmitted diseases

OBJECTIVE

The purpose of this study was to determine whether treatment of bacterial vaginosis (BV) decreases the incidence of sexually transmitted diseases (STDs).

STUDY DESIGN

Women with asymptomatic BV were studied prospectively to determine the effect of treatment of BV for the prevention of STD. Women were assigned randomly to observation or treatment and prophylaxis with intravaginal metronidazole gel. Women were screened monthly for STDs.

RESULTS

Women who were assigned randomly to receive metronidazole gel had a significantly longer time to the development of STDs compared with women in the observation group (P = .02). The 6-month STD rate was 1.58 per person-year (95% CI, 1.29, 1.87) for women in the metronidazole gel group vs 2.29 per person-year (95% CI, 1.95, 2.63) for women in the observational group. The difference in STD rates was driven by a significant difference in the number of chlamydial infections (P = .013).

CONCLUSION

Treatment and twice-weekly prophylactic use of intravaginal metronidazole gel resulted in significantly fewer cases of chlamydia.

Role of antibiotic therapy for bacterial vaginosis and intermediate flora in pregnancy

Bacterial vaginosis and intermediate flora are associated with late miscarriage and preterm delivery. The mechanisms involved are not yet fully understood. Clinical trials of antibiotic therapy to reduce these complications have yielded conflicting results. These trials, however, were conducted in mixed populations of pregnant women with variable risk profiles for preterm delivery. Furthermore, investigators used different criteria for diagnosis, treated with different antibiotics at different doses and via different routes, and initiated treatment at different gestational ages. Over 80% of pregnant women with abnormal vaginal flora have a good outcome, and in some populations the presence of bacterial vaginosis is not associated with preterm delivery, suggesting that other host factors may modify the risk. Recent studies have examined the roles of genetic regulation of host immune response, bacterial pathogenic factors, and enzymes in the vagina, and how these factors interact to drive a given outcome. These markers have the potential to better define the women at maximal risk and therefore guide future interventions. This chapter aims to appraise the current state of treatment of abnormal vaginal flora in pregnancy and suggest appropriate management based on the available evidence.

Sexually transmitted infections and sexual practices in injection drug users and their regular sex partners in Chennai, India

OBJECTIVE

Measuring sexually transmitted infections (STIs) and sexual practices in injection drug users (IDUs) and their regular sex partners.

GOAL

Informing HIV intervention programs.

DESIGN

Cross-sectional.

RESULTS

One percent IDUs and 2% of their regular female sex partners were syphilis infected; 40% (84/211) and 38% respectively (81/211) were infected with HSV-2. 30% IDUs and 5% of their female regular sex partners were HIV positive. Serodiscordant results for syphilis and HSV-2 were noticed. Women having first sex at age<or=17 years and those who had HIV-positive IDUs as their male sexual partner had two times the odds of having any non-HIV-STI (OR 2.04; 95% CI 1.1-3.8; P=0.02 and OR 2.38; 95% CI 1.1-5.1; P=0.02 respectively) in a multivariate model. Women>or=38 years had seven times the odds of having any non-HIV-STI.

CONCLUSION

Reaching out to IDUs and their female regular sex partners with modified STI management guideline and promoting women-controlled safer sex measures are needed harm-reduction measures.

Differences in the composition of vaginal microbial communities found in healthy Caucasian and black women

The maintenance of a low pH in the vagina through the microbial production of lactic acid is known to be an important defense against infectious disease in reproductive age women. Previous studies have shown that this is largely accomplished through the metabolism of lactic acid bacteria, primarily species of Lactobacillus. Despite the importance of this defense mechanism to women's health, differences in the species composition of vaginal bacterial communities among women have not been well defined, nor is it known if and how these differences might be linked to differences in the risk of infection. In this study, we defined and compared the species composition of vaginal bacterial communities in 144 Caucasian and black women in North America. This was carried out based on the profiles of terminal restriction fragments of 16S rRNA genes, and phylogenetic analysis of 16S rRNA gene sequences of the numerically dominant microbial populations. Among all the women sampled, there were eight major kinds of vaginal communities ('supergroups') that occurred in the general populace at a frequency of at least 0.05 (P=0.99). From the distribution of these supergroups among women, it was possible to draw several conclusions. First, there were striking, statistically significant differences (P=0.0) in the rank abundance of community types among women in these racial groups. Second, the incidence of vaginal communities in which lactobacilli were not dominant was higher in black women (33%) as compared to Caucasian women (7%). Communities not dominated by lactobacilli had Atopobium and a diverse array of phylotypes from the order Clostridiales. Third, communities dominated by roughly equal numbers of more than one species of Lactobacillus were rare in black women, but common in Caucasian women. We postulate that because of these differences in composition, not all vaginal communities are equally resilient, and that differences in the vaginal microbiota of Caucasian and black women may at least partly account for known disparities in the susceptibility of women in these racial groups to bacterial vaginosis and sexually transmitted diseases.

Association between bacterial vaginosis and Herpes simplex virus type-2 infection: implications for HIV acquisition studies

OBJECTIVES

Bacterial vaginosis (BV) and Herpes simplex virus type-2 (HSV-2) have been linked to an increased risk of HIV-1 acquisition. Recent research suggests an association between BV and HSV-2 acquisition, but the converse has not been studied. Here, we investigate whether an association exists between BV and HSV-2 infection

METHODS

We examined the determinants of BV occurrence in a cohort of female sex workers in Burkina Faso. Participants were followed every 3 months for diagnosis of genital infections and report of sexual behaviours. Factors associated with BV occurrence were assessed using generalised estimating equation models.

RESULTS

We enrolled 273 women (mean age, 28 years) and conducted 812 follow-up visits (mean 2.93 visit per woman). Baseline seroprevalence of HIV-1, HSV-2 and recent syphilis were 31.5%, 70.1% and 0.4%, respectively, while baseline prevalence of BV, Trichomonas vaginalis (TV) and Candida albicans were 20.5%, 3.3% and 2.5%, respectively. In multivariable analysis, HSV-2 (relative risk (RR) = 1.73, 95% CI 1.12 to 2.65), HIV-1 (RR = 1.76, 95% CI 1.30 to 2.40), TV (RR = 1.5, 95% CI 1.0 to 2.3), and having > or = 3 sexual partners in the preceding week (RR = 2.2, 95% CI 1.1 to 4.6) were independently associated with BV, while hormonal contraception showed a protective effect (RR = 0.11, 95% CI 0.02 to 0.70).

CONCLUSIONS

HSV-2 infection was associated with BV occurrence in this population. As HSV-2 is strongly linked to HIV-1 acquisition, studies assessing the cofactor effect of BV on HIV acquisition should control for the presence of HSV-2. Further studies are required to investigate the relative effect of asymptomatic HSV-2 shedding and/or genital ulcerations on BV occurrence.

Mycoplasma genitalium infection and persistence in a cohort of female sex workers in Nairobi, Kenya

OBJECTIVE

The objective of this study was to assess the risk factors for and persistence of Mycoplasma genitalium (MG) in a highly exposed female population in Kenya.

STUDY DESIGN

Two hundred fifty-eight sex workers in Nairobi, Kenya, 18 to 35 years of age, were enrolled. Every 2 months, cervical samples were collected for MG, Chlamydia trachomatis (CT), and Neisseria gonorrhoeae (GC) testing by polymerase chain reaction.

RESULTS

At enrollment, 16% were infected with MG. Seventy-seven subjects acquired 107 MG infections, giving an incidence of 22.7 per 100 women-years. Incident CT (adjusted hazard ratio [HR] = 2.4; 95% confidence interval [CI] = 1.5-4.0), GC (HR = 2.0; 95% CI = 1.2-3.5), and HIV infection (adjusted HR = 2.2; 95% CI = 1.3-3.7) were associated with an increased risk of MG. Seventeen percent, 9%, and 21% of MG infections persisted 3, 5, and >or=7 months, respectively.

CONCLUSION

The high incidence of MG, greater than that for both CT (14.0%) and GC (8%), association with common sexually transmitted infection risk factors, and persistence in the female genital tract supports its role as a common sexually transmitted infection in Kenyan women.

The Pap smear for detection of bacterial vaginosis

OBJECTIVE

To assess validity of Pap smears in diagnosing bacterial vaginosis.

METHOD

A prospective diagnostic accuracy study with 533 women in Mombasa, Kenya. Diagnosis of bacterial vaginosis using clinical observations scored with simplified Amsel's criteria and Bethesda system for Pap smears was compared with a reference standard (Nugent criteria for gram stains). Both laboratory tests were interpreted blindly.

RESULT

Bacterial vaginosis prevalence was 36.7% (191/521) with Nugent criteria. Pap smear sensitivity and specificity were 59.4% (111/187) and 83.3% (270/324), with corresponding figures for simplified Amsel's criteria of 44.8% (81/181) and 84.8% (263/310). For Pap smear and simplified Amsel's criteria, positive predictive values were 67.3 and 63.3%, and negative predictive values 78.0% and 72.5%.

CONCLUSION

In diagnosing bacterial vaginosis, Pap smears have moderate sensitivity (though higher than simplified Amsel's criteria). Specificity of Pap smears is adequate. Including bacterial vaginosis assessment as a standard component of Pap smears warrants consideration.

Bacterial vaginosis and host immunity

Bacterial vaginosis (BV) has been associated with severe medical consequences including induction of preterm birth and increasing susceptibility to infection by HIV and other genital tract pathogens. Although the mechanism by which BV induces these changes is not yet fully defined, the presence of BV is accompanied by immunologic changes in the lower genital tract environment. The most striking change is the induction of higher levels of proinflammatory cytokines, although this is not accompanied by increased levels of neutrophils. Increased cytokine levels are likely induced by bacterial products present in BV through innate immune recognition pathways such as the toll-like receptors. Recent studies show that changes in HIV susceptibility and HIV detection are associated with changes in bacterial flora. Further research is needed to identify the relative contributions of immune pathways and bacterial flora toward the pathogenic alterations that occur in BV.

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.

Outcomes of loop electrosurgical excision procedure for cervical neoplasia in human immunodeficiency virus-infected women

The objective of this study was to evaluate the treatment outcomes and complications in human immunodeficiency virus (HIV)-infected women undergoing loop electrosurgical excision procedure (LEEP) for cervical neoplasia. The medical record of 60 evaluable HIV-infected women who had abnormal Papanicolaou (Pap) smear and underwent LEEP following colposcopy at Chiang Mai University Hospital between May 1998 and June 2004 was reviewed. Thirty-one (51.7%) had associated genital infection at screening. Twenty-five (41.7%) had opportunistic infection, but only 18 (30.0%) were treated with antiretroviral therapy. The most common abnormal Pap smear was high-grade squamous intraepithelial lesion (46.7%), followed by low-grade squamous intraepithelial lesion (40.0%). Forty (66.7%) women had clear surgical margins after LEEP. Only one (1.7%) woman had severe intraoperative hemorrhage. Early and late postoperative hemorrhage were noted in three (5%) women of each period. Localized infection of the cervix was detected in seven (11.7%) women. Two (3.3%) women developed cervical stenosis at 6 months after LEEP. There was no significant difference in overall complications between HIV-infected women and the control group (P= 0.24). Among 60 HIV-infected women, no statistical difference in the rate of margins involvement (P= 1.00) and complications (P= 0.85) could be demonstrated between HIV-infected women who received antiretroviral therapy and those who did not. Disease-free rate at 6 and 12 months were 97.1% and 88%, respectively. These data demonstrated that LEEP appears to be safe and effective in HIV-infected women.

Intermittent intravaginal antibiotic treatment of bacterial vaginosis in HIV-uninfected and -infected women: a randomized clinical trial

Objective:

Assess efficacy of intermittent intravaginal metronidazole gel treatment in reducing frequency of bacterial vaginosis (BV).

Design:

Randomized, double-masked, placebo-controlled phase 3 trial.

Setting:

Postnatal and family planning clinics of the Queen Elizabeth Central Hospital and two health centers in Blantyre, Malawi.

Participants:

Nonpregnant HIV-uninfected and -infected women.

Intervention:

Intravaginal metronidazole treatment and placebo gels provided at baseline and every 3 mo for 1 y.

Outcome measures:

Primary: Cross-sectional and longitudinal comparisons of BV frequency at baseline, 1 mo after product dispensation (post-treatment evaluation [PTE]), and every quarterly visit. Secondary: Effect of treatment on BV clearance and recurrence.

Results:

Baseline: 842 HIV-uninfected and 844 HIV-infected women were enrolled. The frequency of BV at baseline in treatment and placebo arms, respectively, was 45.9% and 46.8% among HIV-uninfected women, and 60.5% and 56.9% among HIV-infected women. Primary outcomes: At the PTEs the prevalence of BV was consistently lower in treatment than placebo arms irrespective of HIV status. The differences were statistically significant mainly in HIV-uninfected women. Prevalence of BV was also reduced over time in both treatment and placebo arms. In a multivariable analysis that controlled for other covariates, the effect of intravaginal metronidazole treatment gel compared with placebo was not substantial: adjusted relative risk (RR) 0.90, 95% confidence interval (CI) 0.83–0.97 in HIV-uninfected women and adjusted RR 0.95, 95% CI 0.89–1.01 in HIV-infected women. Secondary outcomes: Intravaginal metronidazole treatment gel significantly increased BV clearance (adjusted hazard ratio [HR] 1.34, 95% CI 1.07–1.67 among HIV-uninfected women and adjusted HR 1.29, 95% CI 1.06–1.58 among HIV-infected women) but was not associated with decreased BV recurrence. Safety: No serious adverse events were related to use of intravaginal gels.

Conclusion:

Intermittent microbicide treatment with intravaginal gels is an innovative approach that can reduce the frequency of vaginal infections such as BV.

Background: Bacterial vaginosis (BV) results from a change in the normal balance of bacteria in the vaginal tract, and is very common. In pregnant women, it is associated with poorer outcomes in pregnancy, and is also linked with HIV transmission (although it is not certain that BV actually increases the chance of getting HIV—just because these two occur together it does not necessarily follow that one causes the other). BV can be treated with metronidazole tablets, although these can cause gut symptoms and should not be taken repeatedly. The researchers wanted to carry out a multiclinic–based trial to find out whether a metronidazole gel applied intermittently to the vagina (for five nights every three months) would reduce the frequency of BV among women in Malawi. HIV-infected and HIV-uninfected women, recruited from postnatal and family planning clinics, were randomized to receive either metronidazole gels, or equivalent placebo gels, every three months and were then followed up for 12 months. The primary outcome for the trial was the proportion of women with BV at each quarterly follow-up visit, and the researchers intended to compare this outcome between treatment arms at each visit and also to look at the overall changes over time among women receiving either metronidazole or placebo, looking separately at HIV-infected and HIV-uninfected women.

What this trial shows: In total 1,686 women took part in the trial (842 not infected with HIV, and 844 infected with HIV). The proportion of HIV-uninfected women with BV dropped by around 20% over the course of the trial, both in women using metronidazole and in those using placebo. However, when comparing the proportion of HIV-uninfected women with BV between the two arms of the trial, there did not seem to be a consistent effect: differences were statistically significant at some time points and not others. Among HIV-infected women, there was also a drop over the course of the trial in the proportion of women with BV, irrespective of whether they used metronidazole or placebo. Again, when comparing the rate of BV among HIV-infected women between study arms (metronidazole versus placebo), the researchers did not see a consistent trend; differences were statistically significant at some time points but not others. Overall, when comparing metronidazole and placebo in an analysis that controlled for other factors, the metronidazole gel seemed to show a small effect in reduction of BV among HIV-uninfected women, but no obvious effect among HIV-infected women.

Strengths and limitations: Strengths in the design of this trial include the sample size, which was appropriate to detect an important effect of the metronidazole gel (versus placebo) had one existed, and the randomization and blinding procedures, which were designed to minimize the chance that the trialists or women being enrolled could anticipate to which arm of the trial they might be assigned. A key limitation of this study, as the researchers acknowledge, is the absence of a “no treatment” study arm. The frequency of BV dropped over the course of the trial in women using the placebo gel, raising the possibility that the placebo actually has some effect on bacteria in the vagina. However, a trial with a “no treatment” arm would pose its own problems, since trialists and participants would then not be fully blinded as to their treatment status.

Contribution to the evidence: This trial adds data on the efficacy of metronidazole gel when used intermittently, and among women in the community who may or may not actually have BV. Previous studies have evaluated treatment with metronidazole among women who already have symptoms or a diagnosis of BV. The findings of this trial rule out a substantial effect of metronidazole gel, as compared to placebo gel, in reducing the frequency of BV in this setting.

Association of interleukin-1beta and interleukin-1 receptor antagonist polymorphisms with bacterial vaginosis in non-pregnant Italian women

Bacterial vaginosis (BV) is the most prevalent alteration of vaginal microflora worldwide. BV is a polymicrobial disorder, and its etiology is elusive. Factors predisposing to this recurrent condition are not fully characterized. We aimed to investigate whether interleukin-1beta (IL-1beta) and IL-1 receptor antagonist (IL-1ra) polymorphisms are associated with BV in non-pregnant white Italian women. Genomic DNA was obtained from 164 BV positive, and 406 control women. Two diallelic polymorphisms in the IL-1beta gene (IL-1B) representing C/T base transitions at - 511 and + 3954 positions and a variable number tandem repeats (VNTR) in intron 2 of the IL-1ra gene (IL-1RN) were assessed. We demonstrated that women who were homozygous for - 511 CC or + 3954 TT of the IL-1B gene were at increased risk for BV with an odds ratio (OR) = 1.5 [95% confidence interval (CI) = 1.03-2.14, P = 0.032], and OR = 2.8 (95% CI = 1.37-5.88, P = 0.004), respectively. The haplotype - 511/ + 3954 T-C was protective for BV, with an OR = 0.7 (95% CI = 0.49-0.90, P = 0.009). The IL-1RN VNTR genotype was not associated with BV, although the rare allele 3 showed a trend towards protection (P = 0.049). These data show that host genetic variants at the IL-1beta locus predispose to BV among Caucasian non-pregnant women. Further studies will determine whether these genetic polymorphisms modulate the risk for BV recurrence, and/or BV associated severe adverse outcomes as preterm birth and human immunodeficiency virus transmission.

Bacterial vaginosis in women of low socioeconomic status living in slum areas in Chennai, India

Bacterial vaginosis (BV) is a common cause of vaginitis among women of childbearing age. This study was performed to investigate the prevalence of BV and its association with sexually transmitted infections among 487 women of low socioeconomic status. Blood, vaginal and endocervical swabs were tested for HIV, herpes simplex virus-2 (HSV-2), Treponema pallidum, BV, Chlamydia trachomatis, Neisseria gonorrhoea and Trichomonas vaginalis. Of the women screened for BV, 120 (25, 95% CI 20.8-28.4) were positive and 40 (8.2, 95% CI 5.8-10.6) were intermediate. Bacterial vaginosis was significantly associated with age >25 (P = 0.014) and sexual experience (P = 0.085). Bacterial vaginosis was also related to concurrent infections with T. vaginalis (relative risk (RR) = 6.6, 95% CI 2.8-15.5, P = 0.000) and HSV-2 (RR = 2, 95% CI 1.3-2.9; P = 0.0031). The role of other possible risk factors needs to be explored.

An altered immunity hypothesis for the development of symptomatic bacterial vaginosis

The hypothesis is advanced that the transition from a Lactobacillus-dominated vaginal microflora to a microflora characteristic of bacterial vaginosis (BV), as well as development of the adverse consequences of BV in some women but not in others, are due to alterations in innate immunity. A microbial-induced inhibition of Toll-like receptor expression and/or activity may block induction of proinflammatory immunity and lead to the proliferation of atypical vaginal bacteria. A lack of 70-kDa heat-shock protein production and release in response to abnormal flora would compound this failure to activate antimicrobial immune responses. A deficit in vaginal mannose-binding lectin concentrations would further decrease the capacity for microbial killing and increase the likelihood of bacterial migration from the vagina to the upper genital tract.

Effect of Lactobacillus challenge on Gardnerella vaginalis biofilms

Bacterial vaginosis (BV) is the most common infectious condition in women. It is caused primarily by anaerobic bacteria which rapidly form biofilms recalcitrant to antibiotic treatment, elevate vaginal pH, induce inflammatory processes and displace indigenous lactobacilli from the vault. Gardnerella vaginalis is commonly associated with these infections. Microscopy analysis showed that within 72 h, viable G. vaginalis covered a surface area of 567 microm(2), reached a depth of 16 microm and a density of approximately 104 microm(3). They maintained these levels for a further 3 days unless challenged with lactobacilli strains. Lactobacillus reuteri RC-14 produced the biggest displacement of Gardnerella. This was not due to pH, which remained between 4.7 and 5.1 for all experiments, nor by hydrogen peroxide which is produced in low amounts by strain L. reuteri RC-14, high amounts by L. crispatus 33820 and not at all by L. rhamnosus GR-1. Deconvolution microscopy showed changes in structure and viability of the biofilms, with loss of dense Gardnerella biofilm pods. For the first time, a strain of L. iners, the most commonly isolated vaginal Lactobacillus in healthy women, was tested for potential probiotic properties. It was found to disrupt Gardnerella biofilm surface area, density and depth, albeit to a lesser extent than L. reuteri RC-14. These studies help to provide insight into the clinical situation in which probiotic and indigenous vaginal lactobacilli can interfere with Gardnerella's presence and reduce the risk of bacterial vaginosis.

Reversible deficiency of antimicrobial polypeptides in bacterial vaginosis

Bacterial vaginosis is a common condition associated with increased risk of sexually transmitted diseases, including human immunodeficiency virus infections. In contrast, vulvovaginal candidiasis has a much weaker association with sexually transmitted diseases. We found that vaginal lavage fluid from women with bacterial vaginosis is deficient in antimicrobial polypeptides and antimicrobial activity compared to fluid from healthy women or women with vulvovaginal candidiasis. Effective treatment normalized the concentrations of antimicrobial polypeptides in both bacterial vaginosis and in vulvovaginal candidiasis, suggesting that the abnormalities were a result of the diseases. Unlike in vulvovaginal candidiasis, the neutrophil attractant chemokine interleukin-8 (IL-8) was not increased in bacterial vaginosis, accounting for low concentrations of neutrophil-derived defensins in vaginal fluid. In organotypic cultures of human vaginal epithelium containing dendritic cells, treatment with Lactobacillus jensenii, a typical vaginal resident, induced the synthesis of IL-8 mRNA and the epithelial human beta-defensin-2 mRNA, but a typical bacterial vaginosis pathogen, Gardnerella vaginalis, had no effect. When the two bacteria were combined, Gardnerella vaginalis did not interfere with the immunostimulatory effect of Lactobacillus jensenii. The loss of normal immunostimulatory flora in bacterial vaginosis is thus associated with a local deficiency of multiple innate immune factors, and this deficiency could predispose individuals to sexually transmitted diseases.

Prevalence of Gardnerella vaginalis and Atopobium vaginae in Virginal Women

OBJECTIVES

The objectives of this study was to determine the prevalence of Gardnerella vaginalis and Atopobium vaginae in virginal women and to establish if nonpenetrative sexual activity is associated with these organisms.

GOAL

The goal of this study was to assess prevalence of G. vaginalis and A. vaginae in virginal women.

STUDY DESIGN

Forty-four virginal female patients self-collected tampon specimens, which were tested for G. vaginalis and A. vaginae by polymerase chain reaction, and provided either brief or detailed information regarding sexual practices by self-administered questionnaire.

RESULTS

Twenty women (45%) had G. vaginalis and 3 (7%) A. vaginae detected. Among the 27 who provided detailed information, 12 (46%) had G. vaginalis and none had A. vaginae detected. G. vaginalis was significantly more likely to be detected in those who had participated in oral sex (odds ratio = 22; 95% confidence interval = 2.2-222) and hand-genital contact without penetration (P = 0.02), but not genital-genital contact.

CONCLUSION

This study shows that nonpenetrative intimate sexual contact is associated with carriage of G. vaginalis in virginal women.

Safety and Acceptability of the Candidate Microbicide Carraguard in Thai Women

OBJECTIVE

To determine the safety and acceptability of vaginal application of Carraguard, a carrageenan-derived candidate microbicide gel.

DESIGN

A randomized, placebo-controlled, triple-blinded clinical trial was conducted in Chiang Rai, northern Thailand.

METHODS

Women were asked to insert one applicator of study gel vaginally at least three times per week (with or without sex) and to use gel with condoms every time they had sex. Safety was assessed by visual inspection of the vagina and cervix, changes in vaginal flora and self-reported symptoms at day 14, month 1 and then monthly for up to 1 year. Acceptability was assessed through reported use of the gel, return of used and unused applicators, and quarterly interviews.

RESULTS

One hundred sixty-five women were randomized: 83 to Carraguard and 82 to the placebo (methylcellulose gel) group. Study gel use was similarly high in both groups throughout the trial with an average of four applicators per week. Carraguard use was not associated with abnormal genital clinical findings, abnormal vaginal flora, Pap smear abnormalities or other abnormal clinical signs or symptoms. Adverse events were mostly mild, not attributed to gel use, and similarly distributed between groups. Participants in both groups reported high acceptability.

CONCLUSIONS

Carraguard can safely be used an average of four times per week with or without sex and is acceptable to Thai women. A Phase III efficacy trial of Carraguard is warranted and is currently ongoing in South Africa.

The Occurrence of Vaginal Infections Among HIV-Infected and High-Risk HIV-Uninfected Women

OBJECTIVES

To evaluate changes over time in rates of bacterial vaginosis (BV), trichomoniasis (TV), and yeast vaginitis (YV) among HIV-infected and similar HIV-uninfected women.

METHODS

Two thousand fifty-six HIV-infected women and 554 HIV-uninfected women were evaluated semiannually from 1994 until March 2003 in a prospective cohort study. BV was diagnosed by Gram stain, TV by wet mount, and YV by symptoms with microscopically visible hyphae or positive culture. Trends were assessed using Poisson models.

RESULTS

At baseline, BV was present in 42.8% and 47.0% of HIV-infected and uninfected women (P = 0.21), TV in 6.1% and 7.8% (P = 0.17), and YV in 10.0% and 3.8% (P < 0.001). Over time, rates of BV and TV decreased significantly in both groups, whereas rates of YV declined only among HIV-infected women. Risk of BV was not associated with HIV status, whereas HIV-infected women had a lower risk of TV. Highly active antiretroviral therapy (HAART) use was associated with decreased risk of all 3 infections.

CONCLUSIONS

: Declines in BV, TV, and YV represent decreased morbidity for HIV-infected women and, potentially, decreased risk of transmission of HIV, because each has been associated with increased genital detection of HIV.

Lack of effectiveness of syndromic management in targeting vaginal infections in pregnancy in Entebbe, Uganda

OBJECTIVES

To measure the prevalence of reproductive tract infections (RTIs) during pregnancy in Entebbe, Uganda, and to evaluate the current syndromic diagnosis and management approach in effectively targeting infections, such as bacterial vaginosis (BV) and trichomoniasis, that are associated with low birth weight and prematurity among newborns.

METHODS

We enrolled 250 antenatal clinic attenders. Vaginal swabs and diagnostic tests were performed for BV, Trichomonas vaginalis (TV), candida, Neisseria gonorrhoeae, Chlamydia trachomatis and for HIV-1 and active (TPHA+/RPR+) syphilis infection. Same day treatment was offered for symptoms according to syndromic management guidelines. The treatment actually provided by healthcare workers was documented. Sensitivity, specificity, positive and negative predictive values were used to assess the effectiveness of syndromic management guidelines and practice.

RESULTS

The prevalence of infections were: BV 47.7%, TV 17.3%, candida 60.6%, gonorrhoea 4.3%, chlamydia 5.9%, syphilis 1.6%, and HIV 13.1%. In total, 39.7% of women with BV and 30.2% of those with TV were asymptomatic. The sensitivity of syndromic management as applied by health workers in targeting BV and TV was 50.0% and 66.7%, respectively. This would have increased to 60.3% (BV) and 69.8% (TV) had the algorithm been followed exactly.

CONCLUSIONS

The prevalence of BV and TV seen in this and other African populations is high. High rates of asymptomatic infection and a tendency of healthcare workers to deviate from management guidelines by following their own personal clinical judgment imply that many vaginal infections remain untreated. Alternative strategies, such as presumptive treatment of BV and TV in pregnancy, should be considered.

A phase III clinical trial of antibiotics to reduce chorioamnionitis-related perinatal HIV-1 transmission

OBJECTIVE

A multisite study was conducted in Africa to assess the efficacy of antibiotics to reduce mother-to-child transmission (MTCT) of HIV-1.

DESIGN

A randomized, double-blinded, placebo-controlled, phase III clinical trial.

METHODS

HIV-1-infected women were randomly assigned at 20-24 weeks' gestation to receive either antibiotics (metronidazole plus erythromycin antenatally and metronidazole plus ampicillin intrapartum) or placebo. Maternal study procedures were performed at 20-24, 26-30, and 36 weeks antenatally, and at labor/delivery. Infants were seen at birth, 4-6 weeks, and 3, 6, 9 and 12 months. The primary efficacy endpoints were overall infant HIV-1 infection and HIV-1-free survival at 4-6 weeks. All women and infants received single-dose nevirapine prophylaxis in this study.

RESULTS

A total of 1510 live-born infants were included in the primary analysis. The proportions of HIV-1-infected infants at birth were similar (antibiotics 7.1%; placebo 8.3%; P = 0.41). Likewise, there were no statistically significant differences at 4-6 weeks in the overall risk of MTCT of HIV-1 (antibiotics 16.2%; placebo 15.8%; P = 0.89) or HIV-1-free survival (79.4% in each study arm). Post-randomization, the proportion of women with bacterial vaginosis at the second antenatal visit was significantly lower in the antibiotics arm compared with the placebo arm (23.8 versus 39.7%; P < 0.001), but the frequency of histological chorioamnionitis was not different (antibiotics 36.9%; placebo 39.7%; P = 0.30). Adverse events in mothers and their infants did not differ by randomization arm.

CONCLUSION

This simple antepartum and peripartum antibiotic regimen did not reduce the risk of MTCT of HIV-1.

Microbicides and other topical strategies to prevent vaginal transmission of HIV

The HIV epidemic is, by many criteria, the worst outbreak of infectious disease in history. The rate of new infections is now approximately 5 million per year, mainly in the developing world, and is increasing. Women are now substantially more at risk of infection with HIV than men. With no cure or effective vaccine in sight, a huge effort is required to develop topical agents (often called microbicides) that, applied to the vaginal mucosa, would prevent infection of these high-risk individuals. We discuss the targets for topical agents that have been identified by studies of the biology of HIV infection and provide an overview of the progress towards the development of a usable agent.

Suppressive antibacterial therapy with 0.75% metronidazole vaginal gel to prevent recurrent bacterial vaginosis

OBJECTIVE

Efficacy study of suppressive vaginal metronidazole in reducing recurrent symptomatic episodes of bacterial vaginosis.

STUDY DESIGN

Multicenter prospective study with initial 10-day open-label metronidazole gel in which asymptomatic responders randomly assigned to receive twice weekly metronidazole vaginal gel or placebo for 16 weeks and off therapy for 12 weeks.

RESULTS

Of 157 eligible women with recurrent bacterial vaginosis, 112 of 127 returning evaluable women (88.2%) responded clinically and were randomly assigned. During suppressive therapy, recurrent bacterial vaginosis occurred in 13 women (25.5%) receiving metronidazole and 26 (59.1%) receiving placebo (MITT analysis, relative risk [RR] 0.43, CI = 0.25-0.73, P = .001). During the entire 28-week follow-up, recurrence occurred in 26 (51.0%) on treatment compared with 33 (75%) on placebo (RR 0.68, CI = 0.49-0.93, P = .02). Probability for remaining cured was 70% for metronidazole compared with 39% on placebo, which declined to 34% and 18%, respectively, by 28 weeks follow-up. Adverse effects were uncommon; however, secondary vaginal candidiasis occurred significantly more often in metronidazole-treated women (P = .02).

CONCLUSION

Suppressive therapy with twice-weekly metronidazole gel achieves a significant reduction in the recurrence rate of bacterial vaginosis; however, secondary vaginal candidiasis is common.

Antibiotic susceptibility of Atopobium vaginae

Background

Previous studies have indicated that a recently described anaerobic bacterium, Atopobium vaginae is associated with bacterial vaginosis (BV). Thus far the four isolates of this fastidious micro-organism were found to be highly resistant to metronidazole and susceptible for clindamycin, two antibiotics preferred for the treatment of BV.

Methods

Nine strains of Atopobium vaginae, four strains of Gardnerella vaginalis, two strains of Lactobacillus iners and one strain each of Bifidobacterium breve, B. longum, L. crispatus, L. gasseri and L. jensenii were tested against 15 antimicrobial agents using the Etest.

Results

All nine strains of A. vaginae were highly resistant to nalidixic acid and colistin while being inhibited by low concentrations of clindamycin (range: < 0.016 μg/ml), rifampicin (< 0.002 μg/ml), azithromycin (< 0.016 – 0.32 μg/ml), penicillin (0.008 – 0.25 μg/ml), ampicillin (< 0.016 – 0.94 μg/ml), ciprofloxacin (0.023 – 0.25 μg/ml) and linezolid (0.016 – 0.125 μg/ml). We found a variable susceptibility for metronidazole, ranging from 2 to more than 256 μg/ml. The four G. vaginalis strains were also susceptible for clindamycin (< 0.016 – 0.047 μg/ml) and three strains were susceptible to less than 1 μg/ml of metronidazole. All lactobacilli were resistant to metronidazole (> 256 μg/ml) but susceptible to clindamycin (0.023 – 0.125 μg/ml).

Conclusion

Clindamycin has higher activity against G. vaginalis and A. vaginae than metronidazole, but not all A. vaginae isolates are metronidazole resistant, as seemed to be a straightforward conclusion from previous studies on a more limited number of strains.

Management of genital infections in pregnant women

PURPOSE OF REVIEW

To examine and evaluate ways of managing genital infections in pregnant women.

RECENT FINDINGS

The need to screen for sexually transmitted diseases during pregnancy depends on the prevalence of the condition, its pathogenesis and the cost-benefit analysis for a population or risk group. For a few genital infections with severe impact on the outcome of the pregnancy, such as syphilis and gonorrhoea, a 'screen and treat' policy is almost always cost-effective.

SUMMARY

Genital infections often remain unnoticed during pregnancy, as their signs and symptoms may be seen as part of the normal discomfort of pregnancy. Also it is sometimes not clear whether there are multiple partners or whether the partners have been treated, making re-infection after treatment highly likely. Partner tracing may be difficult, but the 'screen and treat' policy is usually the best solution.

Bacterial vaginosis in female sex workers in Chennai, India

Bacterial vaginosis (BV) causes obstetric and gynaecological complications and non-chlamydial/non-gonococcal pelvic inflammatory disease and has been shown to be associated with the risk of acquiring HIV and herpes simplex (HSV)-2 infections. This study investigated both the prevalence of BV and its association with STDs among 582 female sex workers living in Chennai, South India. Blood, vaginal and endocervical swabs were tested for HSV-2, HIV, Treponema pallidum, BV, Chlamydia trachomatis, Neisseria gonorrhoea and Trichomonas vaginalis. The vaginal swabs collected were Gram's stained and analysed for BV by Nugent's scoring criteria. Of the women studied, 45% (95% CI, 40.6-48.7) were positive, 39.5% (95% CI, 35.5-43.5) were negative and 16% (95% CI, 12.8-18.7) were intermediate for BV. Bacterial vaginosis positivity was directly related to concurrent infection with HSV-2 (RR 1.3, AR 12, P = 0.00), T vaginalis (RR 1.5, AR 10, P = 0.01) T. pallidum (RR 2.8, AR 16, P = 0.00) and HIV (RR 4.1, AR 52, P = 0.01). Future studies are needed to focus on the risk factors for BV.

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.

Vaginal microbial diversity among postmenopausal women with and without hormone replacement therapy

Urogenital infections in postmenopausal women remain problematic. The use of estrogen replacement therapy has been shown to lower these infection rates, corresponding to increasing colonization by Lactobacillus species. Despite the gut's 500 microbial species and the proximity of the anus to the vagina, only a relatively few microbial strains appear to be able to colonize the urogenital area. In the present study, the sparsity of microbes in the vagina was confirmed by denaturing gradient gel electrophoresis analysis of swabs taken at time zero and monthly for 3 months from 40 postmenopausal subjects receiving Premarin (conjugated equine estrogen in combination with progesterone) hormone replacement therapy (HRT) and 20 who were not on HRT. Lactobacilli were recovered from the vagina of 95% or more women in both groups, but in the HRT group, Lactobacillus were more often the dominant and only colonizers and significantly fewer bacteria with pathogenic potential were found. The incidence of bacterial vaginosis was significantly lower in the HRT group than in the non-HRT-treated women (5.6% versus 31%). The use of HRTs has recently come under criticism. The ability of drugs such as Premarin to help recover the lactobacilli vaginal microbiota appears to be at least one benefit of HRT use. In women not using HRTs, use of probiotics may be the only way to restore a nonpathogen-dominated flora.

Bioengineering lactic acid bacteria to secrete the HIV-1 virucide cyanovirin

An urgent need exists to prevent the sexual transmission of HIV-1. With prevalence rates exceeding 35% in parts of sub-Saharan Africa, increasing attention has been placed on developing and testing microbicidal agents capable of preventing virus transmission at mucosal sites. HIV-1 microbicides must meet several requirements before their widespread use. The drugs must be able to neutralize a diversity of HIV-1 strains, not induce mucosal inflammation, be associated with minimal side effects, and be effective for a prolonged period after a single application. Recent work has demonstrated the utility of recombinant lactic acid bacteria (LAB) as agents of mucosal drug delivery. Here, we describe the bioengineering of strains of LAB to secrete the prototypic virucidal compound cyanovirin (CV-N) and demonstrate the anti-HIV-1 activity of secreted CV-N. Our results suggest that recombinant LAB may serve as effective microbicidal compounds and deserve in vivo testing in simian immunodeficiency virus models of mucosal virus transmission.

Modulation of the microbial ecology of the human colon by probiotics, prebiotics and synbiotics to enhance human health: an overview of enabling science and potential applications

The application of probiotics and prebiotics to the manipulation of the microbial ecology of the human colon has recently seen many scientific advances. The sequencing of probiotic genomes is providing a wealth of new information on the biology of these microorganisms. In addition, we are learning more about the interactions of probiotics with human cells and with pathogenic bacteria. An alternative means of modulating the colonic microbial community is by the use of prebiotic oligosaccharides. Increasing knowledge of the metabolism of prebiotics by probiotics is allowing us to consider specifically targeting such dietary intervention tools at specific population groups and specific disease states.