Mobiluncus species in gynaecological and obstetric infections: antimicrobial resistance and prevalence in a Turkish population

Six Bacterial Vaginosis-Associated Species Can Form an In Vitro and Ex Vivo Polymicrobial Biofilm That Is Susceptible to Thymbra capitata Essential Oil

Bacterial vaginosis (BV) is associated with serious gynaecologic and obstetric complications. The hallmark of BV is the presence of a polymicrobial biofilm on the vaginal epithelium, but BV aetiology is still a matter of debate. We have previously developed an in vitro biofilm model that included three BV-associated species, but, up to now, no studies are available whereby more bacterial species are grown together to better mimic the in vivo situation. Herein, we characterized the first polymicrobial BV biofilm consisting of six cultivable BV-associated species by using both in vitro and ex vivo vaginal tissue models. Both models revealed that the six species were able to incorporate the polymicrobial biofilm, at different bacterial concentrations. As it has been thought that this polymicrobial biofilm may increase the survival of BV-associated species when exposed to antibiotics, we also assessed if the Thymbra capitata essential oil (EO), which has recently been shown to be highly bactericidal against several Gardnerella species, could maintain its anti-biofilm activity against this polymicrobial biofilm. Under our experimental conditions, T. capitata EO exhibited a high antibacterial effect against polymicrobial biofilms, in both tested models, with a significant reduction in the biofilm biomass and the number of culturable cells. Overall, this study shows that six BV-associated species can grow together and form a biofilm both in vitro and when using an ex vivo model. Moreover, the data obtained herein should be considered in further applications of T. capitata EO as an antimicrobial agent fighting BV.

Gardnerella and vaginal health: the truth is out there

The human vagina is a dynamic ecosystem in which homeostasis depends on mutually beneficial interactions between the host and their microorganisms. However, the vaginal ecosystem can be thrown off balance by a wide variety of factors. Bacterial vaginosis (BV) is the most common vaginal infection in women of childbearing age but its etiology is not yet fully understood, with different controversial theories being raised over the years. What is generally accepted is that BV is often characterized by a shift in the composition of the normal vaginal microbiota, from a Lactobacillus species dominated microbiota to a mixture of anaerobic and facultative anaerobic bacteria. During BV, a polymicrobial biofilm develops in the vaginal microenvironment, being mainly composed of Gardnerella species. The interactions between vaginal microorganisms are thought to play a pivotal role in the shift from health to disease and might also increase the risk of sexually transmitted infections acquisition. Here, we review the current knowledge regarding the specific interactions that occur in the vaginal niche and discuss mechanisms by which these interactions might be mediated. Furthermore, we discuss the importance of novel strategies to fight chronic vaginal infections.

Antimicrobial Susceptibility and Clonality of Vaginally Derived Multidrug-Resistant Mobiluncus Isolates in China

Here, the antimicrobial susceptibility, resistance mechanisms, and clonality of Mobiluncus sp. isolates recovered from gynecological outpatients in China were investigated. Compared to M. mulieris, M. curtisii exhibited higher antimicrobial resistance to metronidazole, clindamycin, and tetracycline. Whole-genome sequencing indicated that the clindamycin resistance gene erm(X) was located on a transposable element, Tn5432, which was composed of two IS1249 sequences. Phylogenetic analysis indicated that Mobiluncus spp. had high diversity, with isolates being grouped into several sporadic clades.

Berberine exhibits antioxidative effects and reduces apoptosis of the vaginal epithelium in bacterial vaginosis

Bacterial vaginosis (BV) is a common type of vaginitis. Berberine is a natural alkaline product that reduces oxidative stress and apoptosis in cells. The aim of the present study was to investigate the effects of berberine on oxidative stress and apoptotic rates of BV. Vaginal epithelial and discharge samples were obtained from 60 healthy individuals and 180 patients with BV before and after one month of berberine treatment. Clinical observation was documented for all patients before and after treatment for comparison. Additionally, an in vitro study was performed; the samples were divided into groups the following groups: Control, model (H₂O₂-treated), LT (low-dose berberine), MT (medium-dose berberine) and HT (high-dose berberine). Expression levels of the oxidative stress related proteins were detected by western blotting. Clinical symptoms of patients with BV significantly improved following berberine treatment. Oxidative stress in vaginal discharge was significantly lower following treatment, indicated by the increased activity of superoxide dismutase (SOD) and catalase, as well as the reduced levels of malondialdehyde and H₂O₂. Apoptosis of the vaginal epithelial cells was also reduced, which was indicated by the reduced expression of apoptosis proteins caspase-3, cytochrome C, capase-12 and Bax, and increased expression of Bcl-2. The results of the in vitro experiments demonstrated a dose-dependent decrease in apoptosis with berberine treatment compared with levels before treatment. Oxidative stress relief was demonstrated by the reduced reactive oxygen species level and increased SOD and endothelial nitric oxide synthase levels, whereas suppression of apoptosis was further supported by the reduction in apoptotic proteins, as well as a decreased Bax/Bcl-2 ratio. Berberine exhibited effects on lowering oxidative stress in vaginal discharge and reducing oxidative damage, as well as apoptosis of the vaginal epithelium, which are beneficial to patients with bacterial vaginosis.

Antibiotic resistance genes in the Actinobacteria phylum

The Actinobacteria phylum is one of the oldest bacterial phyla that have a significant role in medicine and biotechnology. There are a lot of genera in this phylum that are causing various types of infections in humans, animals, and plants. As well as antimicrobial agents that are used in medicine for infections treatment or prevention of infections, they have been discovered of various genera in this phylum. To date, resistance to antibiotics is rising in different regions of the world and this is a global health threat. The main purpose of this review is the molecular evolution of antibiotic resistance in the Actinobacteria phylum.

Drug Resistance Mechanisms in Bacteria Causing Sexually Transmitted Diseases and Associated with Vaginosis

Here, we review sexually transmitted diseases (STDs) caused by pathogenic bacteria and vaginal infections which result from an overgrowth of opportunistic bacterial microflora. First, we describe the STDs, the corresponding pathogens and the antimicrobials used for their treatment. In addition to the well-known diseases caused by single pathogens (i.e., syphilis, gonococcal infections, and chlamydiosis), we consider polymicrobial reproductive tract infections (especially those that are difficult to effectively clinically manage). Then, we summarize the biochemical mechanisms that lead to antimicrobial resistance and the most recent data on the emergence of drug resistance in STD pathogens and bacteria associated with vaginosis. A large amount of research performed in the last 10-15 years has shed light on the enormous diversity of mechanisms of resistance developed by bacteria. A detailed understanding of the mechanisms of antimicrobials action and the emergence of resistance is necessary to modify existing drugs and to develop new ones directed against new targets.

Sensitive Detection of Thirteen Bacterial Vaginosis-Associated Agents Using Multiplex Polymerase Chain Reaction

Bacterial vaginosis (BV) is characterized by a polymicrobial proliferation of anaerobic bacteria and depletion of lactobacilli, which are components of natural vaginal microbiota. Currently, there are limited conventional methods for BV diagnosis, and these methods are time-consuming, expensive, and rarely allow for the detection of more than one agent simultaneously. Therefore, we conceived and validated a multiplex polymerase chain reaction (M-PCR) assay for the simultaneous screening of thirteen bacterial vaginosis-associated agents (BV-AAs) related to symptomatic BV: Gardnerella vaginalis, Mobiluncus curtisii, Mobiluncus mulieris, Bacteroides fragilis, Mycoplasma hominis, Atopobium vaginae, Ureaplasma urealyticum, Megasphaera type I, Clostridia-like bacteria vaginosis-associated bacteria (BVABs) 1, 2, and 3, Sneathia sanguinegens, and Mycoplasma genitalium. The overall validation parameters of M-PCR compared to single PCR (sPCR) were extremely high, including agreement of 99.1% and sensitivity, specificity, and positive predictive values of 100.0%, negative predictive value of 97.0%, accuracy of 99.3%, and agreement with Nugent results of 100.0%. The prevalence of BV-AAs was very high (72.6%), and simultaneous agents were detected in 53.0%, which demonstrates the effectiveness of the M-PCR assay. Therefore, the M-PCR assay has great potential to impact BV diagnostic methods in vaginal samples and diminish associated complications in the near future.

Treatment of bacterial vaginosis: what we have and what we miss

INTRODUCTION

The disturbing, foul-smelling discharge of bacterial vaginosis (BV) is a nuisance to women. Treatment possibilities for BV are limited and only achieve complete cure in 65 to 85% of cases. In most women, the condition relapses within weeks to months after treatment.

AREAS COVERED

In search of new therapeutic actions to cure, prevent or delay recurrences of BV, PubMed and web of science were searched for papers with i) decent study layout, ii) proper statistics, iii) comparison group (placebo or standard treatment) and iv) language English, French, Dutch or German. The following keywords were used: bacterial vaginosis and treatment or management or therapy or prophylaxis or prevention. Results were grouped in treatment categories and were discussed.

EXPERT OPINION

Clindamycin and metronidazole are the standard drugs for BV. As other antibiotic and acidifying treatments are progressively being studied, like tinidazole, rifaximin, nitrofuran, dequalinium chloride, vitamin C and lactic acid, more options have become available for switching therapy, combining therapies and long-term prophylactic use to prevent recurrences. Further studies are needed. Also, adjuvant therapy with probiotics may have a significant role in improving efficacy and in preventing recurrences. However, it is unlikely that probiotics will replace antibiotherapy.

Methods to improve the efficacy of treatment of inflammatory diseases of small pelvic organsassociated with a mycoplasma infection

The authors present the results of examination and treatment of 40 female patients with recurrent urogenital infections, who had optional and/or obligate anaerobes revealed by bacteriological tests (patients were withdrawn from the study if Neisseria gonorrhoeae, C. trachomatis, Treponema pallidum or Trichomonas vaginalis were revealed). The patients received treatment with doxycycline or josamycin depending on the results of determination of sensitivity of cultivated microorganisms. Evident positive dynamics of clinical manifestations was recorded as a result of use of these drugs. Normalization of biocenosis and absence of opportunistic flora were recorded for 38 patients.

Diagnosis and management of bacterial vaginosis and other types of abnormal vaginal bacterial flora: a review

Bacterial vaginosis (BV) is a common cause of abnormal vaginal discharge. It is characterised by an overgrowth of predominantly anaerobic organisms (Gardnerella vaginalis, Prevotella spp., Peptostreptocci, Mobiluncus spp.) in the vagina leading to a replacement of lactobacilli and an increase in vaginal pH. BV can arise and remit spontaneously, but often presents as a chronic or recurrent disease. BV is found most often in women of childbearing age, but may also be encountered in menopausal women, and is rather rare in children. The clinical and microscopic features and diagnosis of BV are herein reviewed, and antibiotic and non-antibiotic treatment approaches discussed.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this educational activity, the participant should be better able to analyze bacterial vaginosis clinically, formulate an oral antibiotic treatment regimen for bacterial vaginosis and use vaginal treatments for bacterial vaginosis.