Gynecologic Complications of Bacterial Vaginosis: Fact or Fiction?

Characterization of Gardnerella vaginalis membrane vesicles reveals a role in inducing cytotoxicity in vaginal epithelial cells

Bacterial vaginosis (BV) is a common polymicrobial infection affecting women in the reproductive age and is associated with adverse obstetric and gynaecological outcomes. Gardnerella vaginalis is the most virulent anaerobic bacterial species predominantly associated with BV. However, a clear understanding of the mechanisms by which it contributes to the pathogenesis and persistence of BV is lacking. In this report, we demonstrate for the first time, the isolation of membrane vesicles (MVs) from G. vaginalis ATCC 14019. These MVs are approximately 120-260 nm in diameter. Proteomic characterization of the MVs by LC-MS/MS led to the identification of 417 proteins, including proteins involved in cellular metabolism as well as molecular chaperones and certain virulence factors. Immunoblot analysis of the MVs confirmed the presence of vaginolysin, the most well-characterized virulence factor of G. vaginalis. The exposure of the vaginal epithelial cells, VK2/E6E7 to the G. vaginalis MVs resulted in the internalization of the MVs. The MVs induced cytotoxicity and an increase in the levels of the pro-inflammatory cytokine, IL-8 in VK2 cells as well lysis of erythrocytes. The results of the study indicate that G. vaginalis MVs may be involved in the delivery of cytotoxic proteins and other virulence factors to the host cells and could thereby contribute towards enhancing the cellular damage associated with pathogenesis of BV.

A retrospective study on cervical intraepithelial lesions of low-grade and undetermined significance: evolution, associated factors and cytohistological correlation

CONTEXT AND OBJECTIVES

Cervical cancer is an important cause of morbidity and mortality throughout the world. There is some controversy about the factors that may be associated with infection by the human papillomavirus (HPV) that may favor or protect against evolution from a low-grade intraepithelial lesion to a high-grade intraepithelial lesion or invasive neoplasia. The objective here was to evaluate the evolution of low-grade intraepithelial lesions and squamous or glandular lesions of undetermined significance, the associated factors and cytohistological correlations.

DESIGN AND SETTING

Retrospective study conducted in a public tertiary-level university hospital.

METHODS

Information was obtained by reviewing patient records and/or colposcopy reports. A statistical analysis was performed using logistic regression, calculating the odds ratio and applying chi-square tests.

RESULTS

Of the 3390 patients, 409 evolved to high-grade intraepithelial lesions, of which 354 had an initial diagnosis of HPV infection, 27 of squamous atypia of undetermined significance, 22 of low-grade intraepithelial lesions with or without cytological diagnosis of infection by associated HPV and six of glandular cell atypia of undetermined significance.

CONCLUSIONS

Lactobacillus sp and bacterial vaginosis on the smears, smoking and immunodepression were factors associated with evolution. A single partner, use of hormonal contraceptives, lower parity, age and a cytological diagnosis of cytolytic vaginosis, T. vaginalis, Candida sp or cocci were factors associated with protection. With regard to cytohistological correlation, there was a 74.08% agreement among patients with high-grade lesions and a biopsy obtained during the same period.

Use of a lactic acid plus lactoserum intimate liquid soap for external hygiene in the prevention of bacterial vaginosis recurrence after metronidazole oral treatment

OBJECTIVE

To determine the recurrence of bacterial vaginosis (BV) after the use of a lactic acid plus lactoserum liquid soap starting immediately after the treatment with oral metronidazole and the quality of life of the participants.

METHODS

A total of 123 women with diagnosis of BV with at least three of the following criteria: 1) homogeneous vaginal discharge without inflammation of the vagina or vulva; 2) vaginal pH ≥ 4.5; 3) positive Whiff test; and 4) "clue cells" in more than 20% of the epithelial cells in the vagina. A Nugent score ≥ 4 in the vaginal bacterioscopy was also used. After BV diagnosis, metronidazole 500 mg was administered orally bid during 7 days. Patients cured of BV were then instructed to use 7.5 to 10 mL of a lactic acid plus lactoserum liquid soap once-a-day for hygiene of the external genital region. Three subsequent control visits after starting the hygiene treatment (30, 60, and 90 days; ± 5 days) were scheduled. A questionnaire was applied in the form of visual analogue scale (VAS) in all the visits regarding: 1) level of comfort at the genital region; 2) malodorous external genitalia; 3) comfort in sexual intercourse; 4) satisfaction with intimate hygiene; and 5) self-esteem.

RESULTS

Ninety two (74.8%) women initiated the use of a lactic acid plus lactoserum liquid soap at visit 1. At visit 2, 3, and 4 there were 84, 62 and 42 women available for evaluation, respectively. The rate of recurrence of BV was 19.0%, 24.2% and 7.1%, respectively in the three visits and vaginal candidiasis was observed in five treated women. Quality of life was evaluated in the 42 women who completed the four visits schedule and there were significant improvement in the five domains assessed.

CONCLUSION

A lactic acid plus lactoserum liquid soap for external intimate hygiene may be an option for the prevention of BV recurrence after treatment and cure with oral metronidazole.

Evidence of a TH1-shift of local vaginal inflammatory response during bacterial vaginosis

OBJECTIVE

To determine the levels of pro-inflammatory and anti-inflammatory cytokines in the vagina of healthy women and in bacterial vaginosis (BV) patients.

METHODS

Interleukin (IL)-1alpha, 1beta, 5 and 10 were analyzed by ELISA in vaginal wash fluids from 50 non-pregnant patients with BV and 112 healthy women.

RESULTS

Levels of IL-1beta were higher and those of IL-10 lower in BV-patients than in healthy women. There was a tendency towards higher levels of IL-1alpha in BV patients, but these data were not statistically significant.

CONCLUSION

We found evidence for a shift towards a TH1-dominated vaginal cytokine profile in the pathogenesis of BV. Levels of a TH1-cytokine were elevated and those of a TH2-cytokine lowered in BV-patients as compared to healthy controls. This points to a vaginal TH1-response during BV and to the importance of cell-mediated immunity in local vaginal infections.

Personal Digital Assistants Used to Document Compliance of Bacterial Vaginosis Treatment

OBJECTIVE

The objective of this study was to estimate patient compliance with oral and vaginal metronidazole treatment of bacterial vaginosis using personal digital assistants (PDAs) and paper diaries.

GOAL

The goal of this study was to assess a novel compliance documentation approach.

STUDY

After each dose of intravaginal or oral metronidazole, 71 subjects recorded the time on a paper diary and answered questions on a PDA. All PDA entries were unknowingly time-date-stamped. Subjects returned for 2- and 6-week posttreatment examinations. Compliance was calculated using a repeated-measures multivariate analysis of variance (ANOVA).

RESULTS

Mean patient compliance rates within the oral metronidazole group were greater with the paper diary compared with the PDA (68.3% and 50.0%, respectively, P = 0.001). The observed rate of compliance agreement for PDA versus paper diary was 69.0% (kappa = 0.4). The majority of noncompliant subjects reported they were compliant with the PDA and paper diary.

CONCLUSIONS

PDAs could more accurately document true compliance rates and could be reasonable instruments to assess compliance in intravaginal antimicrobial drug or contraceptive trials.

Prevalence of bacterial vaginosis and vaginal flora changes in peri- and postmenopausal women

Our aim was to evaluate the prevalence of bacterial vaginosis and decrease in lactobacillus colonization in women 40 years old or older in relation to menopausal status by evaluation of Gram-stained smears. A total of 1,486 smears from Italian Caucasian women aged 40 to 79 years were examined. Women were classified as follows: fertile (regular cycles) (n = 328), perimenopausal (irregular cycles) (n = 237), and postmenopausal (n = 921), including 331 women on estroprogestinic hormone replacement therapy (HRT). The prevalences of bacterial vaginosis (assessed as a Nugent score of >or=7) in fertile (9.8%) and perimenopausal (11.0%) women were not statistically different, whereas the prevalence was significantly lower overall in postmenopausal women (6.0%) (P = 0.02). Specifically, 6.3% of postmenopausal women without HRT and 5.4% of postmenopausal women with HRT were positive for bacterial vaginosis. The Nugent score system was not adequate for evaluating the normal and intermediate vaginal flora in women over the age of 40 years. High numbers of peri- and postmenopausal women had no lactobacilli and no bacterial-vaginosis-associated microorganisms. This nonpathological absence of lactobacilli in women with a Nugent score of 4 was scored as 4*, and this group was considered separately from the intermediate flora group. A score of 4* was obtained for 2.1% of fertile women, 11.4% of perimenopausal women, 44.1% of postmenopausal women without HRT, and 6.9% of postmenopausal women with HRT. The physiological reduction in lactobacillus colonization of the vagina in postmenopausal women does not cause an increase in bacterial-vaginosis prevalence. Reversion of lactobacillus flora to premenopausal levels due to HRT does not increase the prevalence of bacterial vaginosis in postmenopausal women.

Correlation of local interleukin-1beta levels with specific IgA response against Gardnerella vaginalis cytolysin in women with bacterial vaginosis

PROBLEM

Mucosal immune system activation may represent a critical determinant of adverse sequelae correlated with bacterial vaginosis, as HIV sexual transmission, upper genital tract infections, cervicitis, endometritis, postsurgical infections, and adverse pregnancy outcomes as preterm delivery (PTD), low birth weight (LBW).

METHOD OF STUDY

Levels of interleukin-1beta (IL-1beta), anti-Gardnerella vaginalis hemolysin (Gvh) IgA, pH, Nugent score, and number of leukocytes were measured in vaginal fluids of 60 fertile women with bacterial vaginosis and of 64 healthy controls.

RESULTS

Vaginal IL-1beta levels were nearly 13-fold higher in women with bacterial vaginosis (BV) and were associated with anti-Gvh IgA response. IL-1beta was positively correlated with leukocyte counts in the smear both in healthy and bacterial vaginosis positive women.

CONCLUSIONS

Induction of the proinflammatory cytokine IL-1beta may be a necessary event to elicit an innate immune response to control anaerobic genital tract infections. High levels of vaginal IL-1beta are associated with mounting of an antigen-specific mucosal immune response in women with bacterial vaginosis. Parallel induction of innate and adaptive immune response may be associated with protection from ascent of micro-organisms to the upper genital tract, and from acquiring viral infection through the vaginal tract.