Bacterial vaginosis is not a simple ecological disorder

Mesh and layered electrospun fiber architectures as vehicles for Lactobacillus acidophilus and Lactobacillus crispatus intended for vaginal delivery

Bacterial vaginosis (BV) is a recurrent condition that affects millions of women worldwide. The use of probiotics is a promising alternative or an adjunct to traditional antibiotics for BV prevention and treatment. However, current administration regimens often require daily administration, thus contributing to low user adherence and recurrence. Here, electrospun fibers were designed to separately incorporate and sustain two lactic acid producing model organisms, Lactobacillus crispatus (L. crispatus) and Lactobacillus acidophilus (L. acidophilus). Fibers were made of polyethylene oxide and polylactic-co-glycolic acid in two different architectures, one with distinct layers and the other with co-spun components. Degradation of mesh and layered fibers was evaluated via mass loss and scanning electron microscopy. The results show that after 48 h and 6 days, cultures of mesh and layered fibers yielded as much as 108 and 109 CFU probiotic/mg fiber in total, respectively, with corresponding daily recovery on the order of 108 CFU/(mg·day). In addition, cultures of the fibers yielded lactic acid and caused a significant reduction in pH, indicating a high level of metabolic activity. The formulations did not affect vaginal keratinocyte viability or cell membrane integrity in vitro. Finally, mesh and layered probiotic fiber dosage forms demonstrated inhibition of Gardnerella, one of the most prevalent and abundant bacteria associated with BV, respectively resulting in 8- and 6.5-log decreases in Gardnerella viability in vitro after 24 h. This study provides initial proof of concept that mesh and layered electrospun fiber architectures developed as dissolving films may offer a viable alternative to daily probiotic administration.

Bacterial Vaginosis: What Do We Currently Know?

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

Lactic acid gel versus metronidazole for recurrent bacterial vaginosis in women aged 16 years and over: the VITA RCT

Background

Bacterial vaginosis is a common and distressing condition associated with serious comorbidities. Antibiotic treatment is usually clinically effective in the short term, but recurrence is common and side effects can occur.

Objectives

The objective is to assess whether or not intravaginal lactic acid gel is clinically effective and cost-effective for treating recurrent bacterial vaginosis compared with oral metronidazole (Flagyl, Sanofi).

Design

This was an open-label, multicentre, parallel-arm, randomised (1 : 1) controlled trial.

Setting

This took place in one general practice and 19 sexual health centres in the UK.

Participants

Women aged ≥ 16 years with bacterial vaginosis symptoms and one or more episode(s) within the past 2 years took part.

Interventions

The interventions were 5 ml of intravaginal lactic acid gel taken once daily for 7 days (intervention) or 400-mg oral metronidazole tablets taken twice daily for 7 days (control).

Main outcome measures

The primary outcome was the resolution of bacterial vaginosis symptoms 14 days after randomisation. The secondary outcomes were time to first recurrence of symptoms; number of recurrences and treatment courses over 6 months; microbiological resolution on microscopy of vaginal smears at week 2; time to resolution of symptoms; tolerability, adherence and acceptability of the treatment; prevalence of concurrent sexually transmitted infections; quality of life; and cost-effectiveness.

Results

Recruitment stopped prior to reaching the target of 1900 participants on recommendation from the Data Monitoring Committee and Trial Steering Committee after a planned review of the results indicated that the research question had been answered. Overall, 518 participants were randomised and primary outcome data were available for 409 participants (79%; 204 in the metronidazole arm, 205 in the lactic acid gel arm). Participant-reported symptom resolution at week 2 was higher with metronidazole (143/204; 70%) than with lactic acid gel (97/205; 47%) (adjusted risk difference –23.2%, 95% confidence interval –32.3% to –14.0%). Recurrence in 6 months in a subset of participants who had initial resolution and were available for follow-up was similar across arms (metronidazole arm: 51/72, 71%; lactic acid gel arm: 32/46, 70%). A higher incidence of some side effects was reported with metronidazole than with lactic acid gel (nausea 32% vs. 8%; taste changes 18% vs. 1%; diarrhoea 20% vs. 6%, respectively). At week 2, the average cost per participant with resolved symptoms was £86.94 (metronidazole), compared with £147.00 (lactic acid gel). Some participants preferred using lactic acid gel even if they perceived it to be less effective than metronidazole.

Limitations

Loss to follow-up for collection of the primary outcome data was 21% and was similar in both arms. There is a risk of bias owing to missing outcome data at 3 and 6 months post treatment.

Conclusions

A higher initial response was seen with metronidazole than with lactic acid gel, but subsequent treatment failure was common with both. Lactic acid gel was less cost-effective than metronidazole. In general, women disliked taking repeated courses of metronidazole and preferred lactic acid gel, even when they were aware that it was less likely to provide symptom resolution. In the absence of effective curative therapy, further evaluation of non-antibiotic treatments to control the symptoms of recurrent bacterial vaginosis is required to improve quality of life for these patients. Further microbiological analysis of vaginal samples would be useful to identify additional factors affecting response to treatment.

Trial registration

Current Controlled Trials ISRCTN14161293.

Funding

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 2. See the NIHR Journals Library website for further project information.

Non-antibiotic treatment of bacterial vaginosis-a systematic review

PURPOSE

Bacterial vaginosis (BV) is one of the most common vaginal complaints of women of reproductive age, characterized by a shift from a Lactobacillus-dominated vaginal microbiome towards a more diverse flora of facultative and obligately anaerobic bacteria. BV can increase the risk of preterm births, contracting sexually transmitted infections and developing other chronic health issues. Standard treatment for BV are antibiotics, however despite initial efficacy, they do not provide effective long-term treatment and recurrence or persistence prevention. This systematic review focuses on describing the current study situation and summarizing the newest data on the efficacy of alternative non-antibiotic options, namely probiotic products containing lactobacilli, lactic acid, sucrose gel, combination products with estriol, and supplementation of antibiotics.

METHODS

We conducted a systematic literature search using the MEDLINE database and evaluated the 33 trials which met our inclusion criteria.

CONCLUSION

The diverse study designs produced extremely varied outcomes, but so far the results are promising. Furthermore, these alternatives have shown little to no adverse effects and are consequently generally considered safe to use. In general, the results of this review warrant more thorough trials with larger cohort sizes to provide sufficient evidence for these alternatives to be a part of official treatment recommendations.

Metronidazole versus lactic acid for treating bacterial vaginosis (VITA): protocol for a randomised controlled trial to assess the clinical and cost effectiveness of topical lactic acid gel for treating second and subsequent episodes of bacterial vaginosis

Background

Bacterial vaginosis (BV) affects 30–50% of women at some time in their lives and is an embarrassing and distressing condition which can be associated with potentially serious comorbidities. Current antibiotic treatments such as metronidazole are effective but can result in side effects, and recurrence is common. This trial aims to investigate whether lactic acid gel is clinically effective and cost effective in the treatment of recurrent BV compared with metronidazole.

Methods

VITA is an open-label, multicentre, parallel group randomised controlled trial for women with a clinical diagnosis of BV and at least one previous BV episode in the past 2 years. Participants will be randomised 1:1 to intravaginal lactic acid gel 5 ml once daily for 7 days or oral metronidazole tablets 400 mg twice daily for 7 days. All participants will be followed up for 6 months to assess health status and healthcare costs. A subgroup will be interviewed to further explore adherence, tolerability and acceptability of treatment. The estimated sample size is 1900 participants to detect a 6% absolute increase in response rate to 86% in those receiving lactic acid gel. The primary outcome is participant-reported resolution of BV at Week 2.

Discussion

Results from this trial will help inform UK treatment guidelines for BV and may provide an alternative effective treatment for recurrent episodes of this condition which avoids repeated exposure to antibiotics.

Trial registration

ISRCTN, ISRCTN14161293. Registered on 8 September 2017.

Association Analysis on Recurrence of Bacterial Vaginosis Revealed Microbes and Clinical Variables Important for Treatment Outcome

To investigate the parameters associated with post-treatment recurrence of bacterial vaginosis (BV), clinical factors and vaginal microbiota were examined and analyzed for BV patients who received standard metronidazole therapy. The variables associated with BV recurrence included clinical factors of past BV history, use of intravaginal device, and D7 Nugent score as well as many microbial genera, with Lactobacillus, Enterococcus, Ureaplasma, and Aerococcus being the top contributors. Co-occurrence network analysis showed that whereas overwhelming majority of interbacterial interactions were positive, negative interactions were present and connected mostly to Lactobacillus, Enterococcus, and to a less extent Ureaplasma, suggesting the importance of interbacterial antagonism for treatment outcome. The patients who were cured and recurrent also exhibited clear differences in the species composition of Lactobacillus: although L. iners remained the dominant species at all time points, L. crispatus, L. gasseri, and L. jensenii displayed apparent differences in relative abundance between the cure and recurrent groups. Based on these results, we developed a 5-component panel comprising Enterococcus, L. crispatus, Ureaplasma, Aerococcus, and L. jensenii for predicting recurrence using D7 data and showed that it generated the specificity, sensitivity, and AUC values of 0.80, 0.66, and 0.73 for the discovery cohort and 0.80, 0.67, and 0.69 for the validation cohort. Our findings highlighted key microbial components for BV recurrence and suggested that they could be used to monitor the treatment outcome.

Sustained delivery of commensal bacteria from pod-intravaginal rings

Topical administration of live commensal bacteria to the vaginal tract holds significant potential as a cost-effective strategy for the treatment of sexually transmitted infections and the delivery of mucosal vaccines. Probiotic-releasing intravaginal rings (IVRs) embody significant theoretical advantages over traditional daily-dosage forms, such as sustained and controlled delivery leading to improved adherence to therapy compared to that of frequent dosing. The conventional IVR designs, however, are not amenable to the delivery of live bacteria. We have developed a novel pod-IVR technology where polymer-coated tablets ("pods") of Lactobacillus gasseri strain ATCC 33323, a commensal microorganism of human origin, are embedded in silicone IVRs. The release rate of bacterial cells is controlled by the diameter of a delivery channel that exposes a portion of the pod to external fluids. In vitro studies demonstrated that the prototype devices released between 1.1×10(7) and 14×10(7) cells per day for up to 21 days in a controlled sustained fashion with stable burst-free release kinetics. The daily release rates were correlated with the cross-sectional area of the delivery channel. Bacteria in the IVR pods remained viable throughout the in vitro studies and formed biofilms on the surfaces of the devices. This proof-of-principle study represents the first demonstration of a prolonged, sustained release of bacteria from an intravaginal device and warrants further investigation of this device as a nonchemotherapeutic agent for the restoration and maintenance of normal urogenital flora.

The aetiology of bacterial vaginosis

Bacterial vaginosis (BV) is the most common vaginal infection among women of childbearing age. This condition is notorious for causing severe complications related to the reproductive health of women. Five decades of intense research established many risk factors for acquisition of BV; however, because of the complexity of BV and lack of a reliable animal model for this condition, its exact aetiology remains elusive. In this manuscript, we use a historical perspective to critically review the development of major theories on the aetiology of BV, ultimately implicating BV-related pathogens, healthy vaginal microbiota, bacteriophages and the immune response of the host. None of these theories on their own can reliably explain the epidemiological data. Instead, BV is caused by a complex interaction of multiple factors, which include the numerous components of the vaginal microbial ecosystem and their human host. Many of these factors are yet to be characterized because a clear understanding of their relative contribution to the aetiology of BV is pivotal to the formulation of an effective treatment for and prophylaxis of this condition.

Bacterial vaginosis: an update on diagnosis and treatment

Bacterial vaginosis is the most common cause of vaginal complaints. Bacterial vaginosis is further associated with a sizeable burden of infectious complications. Diagnosis relies on standardized clinical criteria or on scoring bacterial cell morphotypes on a Gram-stained vaginal smear. A few point-of-care tests have not gained footage in clinical practice, but molecular diagnosis is now pending. Treatment remains cumbersome and clinicians are currently rather poorly armed to treat bacterial vaginosis in the long run. As an adjuvant to standard treatment with antibiotics, alternative treatments with antiseptics and disinfectants, vaginal-acidifying and -buffering agents, and probiotics hold some promise for long-term prevention.

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.

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.

A pilot clinical trial comparing an acid-buffering formulation (ACIDFORM gel) with metronidazole gel for the treatment of symptomatic bacterial vaginosis

AIM

To compare the effectiveness of an acid-buffering formulation gel (ACIDFORM) with metronidazole gel in the treatment of symptomatic bacterial vaginosis (BV).

METHODS

After a confirmed diagnosis of BV according to the criteria established by Nugent and Amsel, 30 nonpregnant women were enrolled in a randomized, double-blind clinical study. The women were randomly assigned to receive either 5 g ACIDFORM gel (n = 13) or 10% metronidazole gel (n = 17) intravaginally once daily for five consecutive days. Participants were evaluated in two follow-up visits (7-12 days and 28-35 days after treatment). Therapeutic success was defined as the presence of less than three of Amsel's criteria. If three or more criteria were present at first or second follow-up visit, the woman was excluded from the study and treated orally with metronidazole. Nugent scores were recorded at each visit but these were not used to define cure.

RESULTS

At the first follow-up visit, 15 (88%) of the women in the metronidazole group were cured compared with only three (23%) in the ACIDFORM group (P < 0.001). The remaining 12 women (10 of the ACIDFORM group and two of the metronidazole group) were considered as failure and were treated orally with metronidazole. At the second follow-up visit, two of the ACIDFORM-treated women and six of the metronidazole-treated women presented recurrent BV. Four women in the ACIDFORM group and one in the metronidazole group reported occasional burning and itching during product use.

CONCLUSION

ACIDFORM gel was significantly less effective than high-dose metronidazole gel for the treatment of symptomatic BV.

Vaginal pH-lowering effect of locally applied vitamin C in subjects with high vaginal pH

The primary objective of this randomized, double-blind, controlled study was the assessment of the pH-lowering effect of three different formulations of a vaginal device each containing 250 mg vitamin C. Overall, 39 women with vaginal pH >or=5, without evidence of vaginal infections, were randomly assigned to receive one of the three formulations for 6 days. The primary parameter assessed was vaginal pH, performed by the physician at the baseline and final visits and by the subjects each day during the application period; secondary parameters included the acceptability and safety profile of the tested devices. A decrease in pH to the normal range in all groups was observed following the first application, with stable low values during the whole study period. No statistically significant differences were seen among the three groups, while statistically significant within-group differences were observed. Acceptability and tolerability were rated as very good/good in most cases. The study results confirm that the vaginal application of vitamin C has an effective and long-lasting vaginal pH-lowering effect.

A Randomized, Double-Blind Clinical Trial of Vaginal Acidification versus Placebo for the Treatment of Symptomatic Bacterial Vaginosis

BACKGROUND AND OBJECTIVES

Vaginal acidification has been suggested as a means of normalizing the vaginal flora.

GOAL

The purpose of this study was to determine the effectiveness of an acetic acid-based vaginal gel in the treatment of bacterial vaginosis (BV).

STUDY DESIGN

Forty-four patients with BV were enrolled in a randomized, double-blind clinic trial. Of these, 29 were evaluable. Patients were randomized to receive either 5 mL acetic acid gel (n = 14) or placebo gel (n = 15) intravaginally twice daily for 7 days. Clinical criteria and vaginal Gram stain scores were compared between the initial visit and at 2 weeks after initiating therapy.

RESULTS

No significant differences were noted when comparing drug and placebo in terms of subjective or clinical improvement or improvement in Gram stain smears for bacterial vaginosis.

CONCLUSION

Vaginal acidification with an acetic acid gel formulated to pH 3.9 to 4.1 was ineffective therapy for bacterial vaginosis.

Vaginal microflora in healthy women with Gardnerella vaginalis

In order to find the vaginal prevalence of Gardnerella vaginalis in a normal female population, we determined the incidence of G. vaginalis in relation to that of other bacterial genera and species in the vagina. Two-hundred and thirty-nine healthy women were the subjects of this study. Vaginal discharge was collected and bacteriological studies were performed. The mean total aerobe count in the G. vaginalis-positive group was 9.02 log10 colony-forming units (CFU)/g, which was significantly higher (P < 0.0001) than that (6.80 log10 CFU/g) in the G. vaginalis-negative group. In contrast, there was no difference in the mean total anaerobe count between the two groups of subjects (8.82 and 8.24 log10 CFU/g, respectively in the case of including Lactobacillus species count). Also, the mean pH level of vaginal secretion in the G. vaginalis-positive group was 4.58, which was significantly higher (P < 0.005) than that (4.10) in the G. vaginalis-negative group. Aerobes were isolated at equal incidence in the two groups. Anaerobes were isolated at a significantly higher rate in the G. vaginalis-positive group (P < 0.005) than in the G. vaginalis-negative group. The mean count of Lactobacillus species was significantly higher (P < 0.0001) in the G. vaginalis-negative group than in the positive counterpart (7.02 vs 8.66). Elevation of vaginal pH, an increase in the anaerobe count, and decreases in the Lactobacillus species count could be good predictors of the prevalence of bacterial vaginosis in healthy women.

Bacterial vaginosis in pregnancy: an approach for the 1990s

It is proposed that clinicians screen all pregnant women at high risk for preterm labor and premature rupture of membranes for bacterial vaginosis, and treat all women when it is diagnosed. This infection is associated with a two to three times increase in preterm labor and delivery, premature rupture of the membranes, and endometritis. Although cause and effect have not been conclusively documented, these associations must be considered in the practice of obstetrics at the present. The paucity of vaginal Lactobacillus spp is pivotal in allowing overgrowth of many other organisms of the vagina. Screening is suggested because 50 percent of bacterial vaginosis is asymptomatic. The diagnosis, which is rapidly made and inexpensive, remains defined by clue cells seen on wet prep, high vaginal pH, and amine odor of the vaginal discharge. Optimal treatment of pregnant women with bacterial vaginosis is via oral or intravaginal metronidazole or clindamycin.

Vaginal microbiological flora and sexually transmitted diseases in women with recurrent or current vulvovaginal candidiasis

A history of recurrent vulvovaginal candidiasis (RVVC) was reported by 102 women, while current vulvovaginal candidiasis (VVC) was diagnosed in 83 of the same 996 women. They had all attended two family planning and one youth clinic, respectively. Two women, without RVVC or VVC, matched for age for each case of RVVC, were selected as a comparison group (COMP). Recurrent, but not current VVC, was associated with a history of sexually transmitted disease. Those with current, but not with recurrent, VVC had significantly more often genital warts and bacteriuria (> 10(5) bacteria/ml), but significantly less often bacterial vaginosis than the COMP women. Both VVC and RVVC were inversely correlated to a vaginal flora change with a mixed anaerobic vaginal flora. Those with VVC had a greater number of lactobacilli on vaginal cultures, than those with RVVC and the women in the COMP group. VVC and a history of RVVC both occurred more frequently in women with a lactobacilli-predominated vaginal flora, as compared with those with a flora change with a mixture of anaerobic and facultative anaerobic bacteria.

Effect of lactic acid suppositories compared with oral metronidazole and placebo in bacterial vaginosis: a randomised clinical trial

OBJECTIVE

To compare the effect of lactic acid locally, metronidazole orally and placebo in women with bacterial vaginosis.

DESIGN

Randomised clinical trial.

SETTING

30 general practices in the Netherlands.

PATIENTS

125 women consulting the general practitioner for symptomatic bacterial vaginosis.

MAIN OUTCOME MEASURES

Duration of subjective symptoms, recurrence of symptoms, clinically diagnosed cure, adverse events.

RESULTS

Survival analysis showed a significantly faster disappearance of symptoms in the metronidazole category compared with both lactic acid and placebo (p = 0.0005 metronidazole v placebo, p = 0.0002 metronidazole v lactic acid p = 0.6521 lactic acid v placebo [The stratified Mantel Cox test]). The median duration until absence of symptoms was 21 days for metronidazole and 80 days for placebo. Disappearance of symptoms did not occur in 50% of the lactic acid group in 90 days. Recurrence rates of symptoms were similar over the treatment categories (p = 0.13 metronidazole v placebo and p = 0.12 lactic acid v placebo). After 2 weeks cure rates (cure defined as less than three of four clinical criteria present) were 83%, 49% and 47% for metronidazole, lactic acid and placebo category respectively. At that time cure rates (cure defined as none of three clinical criteria present) were 10%, 0% and 3%. After four weeks and three months these figures were: 55%, 20%, 20% and 64%, 28%, 28%. No differences in adverse events were found between the three interventions.

CONCLUSIONS

Lactic acid suppositories are ineffective, metronidazole capsules are effective on signs and symptoms in bacterial vaginosis. A considerable proportion of the patients recover without active medication.

Vaginal flora and pelvic inflammatory disease

Forty-one patients with acute pelvic inflammatory disease were evaluated for the coexistence of bacterial vaginosis. Because all patients had a copious purulent vaginal discharge, microscopic criteria could not be used and microbiologic criteria were employed. The vaginal bacterial flora were not consistent with that of bacterial vaginosis, because Lactobacillus and other gram-positive bacteria dominated with colony counts of 10(3) to 10(5) cfu/ml (colony-forming units per milliliter). Endocervical specimens yielded Neisseria gonorrhoeae from 20 patients and Chlamydia trachomatis from 11 patients. Anaerobes were not dominant in any site sampled. A total of 147 bacteria were isolated from the endometrium, 16 (11%) of which were anaerobes. Thus the endogenous bacterial flora were not consistent with that of the microbiologic definition of bacterial vaginosis. N. gonorrhoeae was the most common isolate from the endocervix and endometrium; it was isolated three times more frequently from the endocervix and two times more frequently from the endometrium than was C. trachomatis.

Gardnerella vaginalis: characteristics, clinical considerations, and controversies

The clinical significance, Gram stain reaction, and genus affiliation of Gardnerella vaginalis have been controversial since Gardner and Dukes described the organism as the cause of "nonspecific vaginitis," a common disease of women which is now called bacterial vaginosis. The organism was named G. vaginalis when taxonomic studies showed that it was unrelated to bacteria in various genera including Haemophilus and Corynebacterium. Electron microscopy and chemical analyses have elucidated the organism's gram-variable reaction. Controversy over the etiology of bacterial vaginosis was largely resolved by (i) studies using improved media and methods for the isolation and identification of bacteria in vaginal fluids and (ii) standardization of criteria for clinical and laboratory diagnosis. Besides G. vaginalis, Mobiluncus spp., Mycoplasma hominis, and certain obligate anaerobes are now acknowledged as participants in bacterial vaginosis. The finding that G. vaginalis, Mobiluncus spp., and M. hominis inhabit the rectum indicates a potential source of autoinfection in addition to sexual transmission. Extravaginal infections with G. vaginalis are increasingly recognized, especially when the toxic anticoagulant polyanetholesulfonate is omitted from blood cultures and when urine cultures are incubated anaerobically for 48 h. The finding that mares harbor G. vaginalis suggests that an equine model can be developed for studies of Gardnerella pathogenesis.