How to diagnose and treat aerobic and desquamative inflammatory vaginitis

A Novel Approach for the Treatment of Aerobic Vaginitis: Azithromycin Liposomes-in-Chitosan Hydrogel

Biocompatible mucoadhesive formulations that enable a sustained drug delivery at the site of action, while exhibiting inherent antimicrobial activity, are of great importance for improved local therapy of vaginal infections. The aim of this research was to prepare and evaluate the potential of the several types of azithromycin (AZM)-liposomes (180-250 nm) incorporated into chitosan hydrogel (AZM-liposomal hydrogels) for the treatment of aerobic vaginitis. AZM-liposomal hydrogels were characterized for in vitro release, and rheological, texture, and mucoadhesive properties under conditions simulating the vaginal site of application. The role of chitosan as a hydrogel-forming polymer with intrinsic antimicrobial properties was explored against several bacterial strains typical for aerobic vaginitis as well as its potential effect on the anti-staphylococcal activity of AZM-liposomes. Chitosan hydrogel prolonged the release of the liposomal drug and exhibited inherent antimicrobial activity. Additionally, it boosted the antibacterial effect of all tested AZM-liposomes. All AZM-liposomal hydrogels were biocompatible with the HeLa cells and demonstrated mechanical properties suitable for vaginal application, thus confirming their potential for enhanced local therapy of aerobic vaginitis.

Aerobic Vaginitis Diagnosis Criteria Combining Gram Stain with Clinical Features: An Establishment and Prospective Validation Study

Wet-mount microscopy aerobic vaginitis (AV) diagnostic criteria need phase-contrast microscopy and keen microscopists, and the preservation of saline smears is less common in clinical practice. This research work developed new AV diagnostic criteria that combine Gram stain with clinical features. We enrolled 325 AV patients and 325 controls as a study population to develop new AV diagnostic criteria. Then, an independent group, which included 500 women, was used as a validation population. AV-related microscopic findings on Gram-stained and wet-mount smears from the same participants were compared. The accuracy of bacterial indicators from the two methods was verified by bacterial 16S rRNA V4 sequencing (n = 240). Logistic regression was used to analyse AV-related clinical features. The screened clinical features were combined with Gram-stain microscopic indicators to establish new AV diagnostic criteria. There were no significant differences in the leukocyte counts or the parabasal epitheliocytes (PBC) proportion between the Gram-stain and wet-mount methods (400×). Gram stain (1000×) satisfied the ability to identify bacteria as verified by 16S rRNA sequencing but failed to identify toxic leukocytes. The new criteria included: Lactobacillary grades (LBG) and background flora (Gram stain, 1000×), leukocytes count and PBC proportion (Gram stain, 400×), and clinical features (vaginal pH > 4.5, vagina hyperemia, and yellow discharge). These criteria satisfied the accuracy and reliability for AV diagnosis (Se = 86.79%, Sp = 95.97%, and Kendall’s W value = 0.899) in perspective validation. In summary, we proposed an alternative and valuable AV diagnostic criteria based on the Gram stain, which can make it possible to diagnose common vaginitis like AV, BV, VVC, and mixed infections on the same smear and can be available for artificial intelligence diagnosis in the future.

Nanomedicines for the topical treatment of vulvovaginal infections: Addressing the challenges of antimicrobial resistance

Recent years have, surprisingly, witnessed an increase in incidence of sexually transmitted infections (STIs). At the same time, antimicrobial therapy came under the threat of ever rising antimicrobial resistance (AMR), resulting in STIs with extremely limited therapy options. In this review, we addressed the challenges of treating vaginal infections in an era of AMR. We focused on published work regarding nanomedicine destined for localized treatment of vaginal infections. Localized therapy offers numerous advantages such as assuring high drug concentration at the infection site, limiting systemic drug exposure that can lead to faster development of AMR reduction in the systemic side effects and potentially safe therapy in pregnancy. We provided a state-of-the-art overview of nanoformulations proposed to topically treat STIs, emphasizing the challenges and advantages of each type of nanocarriers, as well as issues of potential toxicity.

In vivo prophylactic efficacy of Lactobacillus reuteri MT180537 against aerobic vaginitis

Aerobic vaginitis is a recently described vaginal infection that is treated with antibiotics, which cause undesirable effects leading to disturbance in normal vaginal flora and antibiotic resistance among pathogens. Probiotics may be considered as a natural alternative therapy. We investigated antagonistic and immunomodulatory potential of intravaginally administered probiotic Lactobacillus reuteri-MT180537 against vaginal colonization by Enterococcus faecalis-MW051601 in mice. In vitro antimicrobial potential of lactic acid bacteria was determined against major pathogens of aerobic vaginitis. Moreover, in vivo prophylactic efficacy of L. reuteri-MT180537 against E. faecalis-MW051601 induced AV, in β-estradiol immunosuppressed mice was determined for the first time. Lactic acid bacteria displayed antibacterial activity against pathogens with zone of inhibition (11.33-20.00 mm) and co-aggregation (40-67%). Animals receiving L. reuteri-MT180537 followed by E. faecalis-MW051601 challenge exhibited significant reduction in clinical index, vaginal bacterial load, and histopathological changes in vaginal tissues compared to animals receiving E. faecalis-MW051601 only. L. reuteri-MT180537 upregulated expression of anti-inflammatory (Foxp3, IFN-γ) cytokines and resulted in controlling E. faecalis-MW051601 induced over expression of pro-inflammatory (IL-6, IL-1β) cytokines. Altogether, L. reuteri-MT180537 displayed antagonistic properties in vitro and prevented aerobic vaginitis by inhibiting the growth of E. faecalis-MW051601 and regulating expression of pro-inflammatory and anti-inflammatory cytokines in mice.

Aerobic vaginitis - An underdiagnosed cause of vaginal discharge - Narrative review

The concept of vaginal dysbiosis was for long considered synonymous with bacterial vaginosis (BV), which is characterized by a homogenous non-inflammatory vaginal discharge. The inflammatory variant of vaginal dysbiosis, called aerobic vaginitis (AV), has remained unknown to a large part of the global dermatology and venereology community, gynaecologists and reproductive tract infection specialists with consequential under diagnosis. AV significantly differs from BV, in clinical presentation, diagnostic criteria and management. The deleterious impact of untreated AV on pregnancy merits discussion. Understanding AV is also crucial for better comprehension of desquamative inflammatory vaginitis (DIV), the most severe form of the same entity. We review the condition's epidemiology, risk factors and suspected aetiology, symptoms and signs, and the latest evidence-backed approach to diagnosis and treatment. The ideal diagnostic approach and treatment for AV/DIV are yet to be established. The currently recommended diagnostic approach for AV/DIV merits an overhaul by incorporating changes to render it feasible for resource-constraint countries. The diagnostic criteria lack a uniform applicability in different physiological groups of women and cannot be used in postpartum or postmenopausal states at the same cut-off levels. Similarly, treatment guidelines merit a relook, and customization, given the equivocality of options suggested by different investigators.

Gardnerella vaginalis as a Cause of Bacterial Vaginosis: Appraisal of the Evidence From in vivo Models

Koch's postulates dictate the use of experimental models to illustrate features of human disease and provide evidence for a singular organism as the cause. The underlying cause(s) of bacterial vaginosis (BV) has been debated in the literature for over half a century. In 1955, it was first reported that a bacterium now known as Gardnerella vaginalis may be the cause of a condition (BV) resulting in higher vaginal pH, thin discharge, a fishy odor, and the presence of epithelial cells covered in bacteria. Here we review contemporary and historical studies on BV with a focus on reports of experimental infections in human or animal models using Gardnerella vaginalis. We evaluate experimental evidence for the hypothesis that G. vaginalis is sufficient to trigger clinical features of BV or relevant health complications associated with the condition. Additionally, we evaluate in vivo models of co-infection employing G. vaginalis together with other bacterial species to investigate evidence for the hypothesis that G. vaginalis may encourage colonization or virulence of other potential pathogens. Together, these studies paint a complex picture in which G. vaginalis has both direct and indirect roles in the features, health complications, and co-infections associated with BV. We briefly review the current taxonomic landscape and genetic diversity pertinent to Gardnerella and note the limitations of sequence-based studies using different marker genes and priming sites. Although much more study is needed to refine our understanding of how BV develops and persists within the human host, applications of the experimental aspects of Koch's postulates have provided an important glimpse into some of the causal relationships that may govern this condition in vivo.

Vaginal Microbiota and In Vitro Fertilization Outcomes: Development of a Simple Diagnostic Tool to Predict Patients at Risk of a Poor Reproductive Outcome

BACKGROUND

Female reproductive tract microbiota may affect human reproduction. The current study considered whether a more detailed characterization of the vaginal microbiota could improve prediction of risk of poor reproductive outcome in patients undergoing in vitro fertilization (IVF).

METHODS

Vaginal samples from 120 patients undergoing IVF were sequenced using the V4 region of the 16S ribosomal RNA gene with clustering of Gardnerella vaginalis genomic clades. Abnormal vaginal microbiota was defined by microscopy and quantitative polymerase chain reaction (qPCR) for G. vaginalis and/or Atopobium vaginae above a threshold.

RESULTS

Three major community state types with abundance of Lactobacillus crispatus, Lactobacillus iners, and a diverse community type were identified, including 2 subtypes, characterized by a high abundance of L. crispatus and L. iners, respectively, but in combination with common diversity type operational taxonomic units. No significant association between community state type and the reproductive outcome could be demonstrated; however, abnormal vaginal microbiota by qPCR and a grouping based on high Shannon diversity index predicted the reproductive outcome equally well.

CONCLUSIONS

The predictive value of 16S ribosomal RNA gene sequencing was not superior to the simpler and less expensive qPCR diagnostic approach in predicting the risk of a poor reproductive outcome in patients undergoing IVF.

CLINICAL TRIALS REGISTRATION

NCT02042352.

2018 European (IUSTI/WHO) International Union against sexually transmitted infections (IUSTI) World Health Organisation (WHO) guideline on the management of vaginal discharge

Four common pathological conditions are associated with vaginal discharge: bacterial vaginosis, aerobic vaginitis, candidosis, and the sexually transmitted infection, trichomoniasis. Chlamydial or gonococcal cervical infection may result in vaginal discharge. Vaginal discharge may be caused by a range of other physiological and pathological conditions including atrophic vaginitis, desquamative inflammatory vaginitis, cervicitis, and mucoid ectopy. Psychosexual problems may present with recurrent episodes of vaginal discharge and vulval burning. These need to be considered if tests for specific infections are negative. Many of the symptoms and signs are non-specific and a number of women may have other conditions such as vulval dermatoses or allergic and irritant reactions.

Eve's garden: myths, legends and secrets unmasked

This special issue of Research in Microbiology aims to provide some insights in one of women's most fascinating interacting microbial communities: the vaginal microbiome. Even in the 21st century, with many advanced methods at hand, the definition of the healthy vaginal microbiome remains under debate. The interest in studying the dysbiosis of the vaginal microbiome is increasing and goes well beyond the study of bacterial vaginosis. The selection of contributions in this issue summarizes what is currently known in terms of inter- and intra-microorganisms interaction as well as the virulence factors that some of them may deploy.

Aerobic vaginitis: no longer a stranger

Aerobic vaginitis (AV) is the name given in 2002 to a vaginal infectious entity which was not recognized as such before. It is characterized by abnormal (dysbiotic) vaginal microflora containing aerobic, enteric bacteria, variable levels of vaginal inflammation and deficient epithelial maturation. Although AV and bacterial vaginosis (BV) share some characteristics, such as a diminished number or absence of lactobacilli, increased discharge (fishy smelling in BV, while in severe forms of AV, a foul, rather rotten smell may be present) and increased pH (often more pronounced in AV), there are also striking differences between the two. There is no inflammation in women with BV, whereas the vagina of women with AV often appears red and edematous, and may even display small erosions or ulcerations. The color of the discharge in BV is usually whitish or gray and of a watery consistency, whereas in AV it is yellow to green and rather thick and mucoid. Women with BV do not have dyspareunia, while some women with severe AV do. Finally, the microscopic appearance differs in various aspects, such as the presence of leucocytes and parabasal or immature epithelial cells in AV and the absence of the granular aspect of the microflora, typical of BV. Despite all these differences, the distinction between AV and BV was not recognized in many former studies, leading to incomplete and imprecise diagnostic workouts and erroneous management of patients in both clinical and research settings. The prevalence of AV ranges between 7 and 12%, and is therefore less prevalent than BV. Although still largely undiagnosed, many researchers and clinicians increasingly take it into account as a cause of symptomatic vaginitis. AV can co-occur with other entities, such as BV and candidiasis. It can be associated with dyspareunia, sexually transmitted infections (such as human papilloma virus, human immunodeficiency virus, Trichomonas vaginalis and Chlamydia trachomatis), chorioamnionitis, fetal infection, preterm birth and cervical dysplasia. Many other possible pathological associations are currently under investigation. The diagnosis of AV is made using wet mount microscopy, ideally using phase contrast. An AV score is calculated, according to: lactobacillary grade, presence of inflammation, proportion of toxic leucocytes, characteristics of the microflora and presence of immature epithelial cells. To circumvent the hurdle of microscopic investigation, some groups have begun to develop nucleic-acid-based and enzymatic diagnostic tests, but the detailed information obtained with phase contrast microscopy is irreplaceable. The best treatment is not yet fully determined, but it must be tailored according to the microscopic findings and the patient's needs. There is a role for local estrogen therapy, corticosteroids, antimicrobials and probiotics. Further research will reveal more precise data on diagnosis, pathogenesis, management and prevention.