This study investigates the antagonistic effects of the probiotic strains Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 against vulvovaginal candidiasis (VVC)-causing Candida glabrata.
Methods and Results
Growth inhibitory activities of Lact. rhamnosus GR-1 and Lact. reuteri RC-14 strains against C. glabrata were demonstrated using a spot overlay assay and a plate-based microtitre assay. In addition, these probiotic lactobacilli strains also exhibited potent candidacidal activity against C. glabrata, as demonstrated by a LIVE/DEAD yeast viability assay performed using confocal laser scanning microscopy. The metabolic activities of all C. glabrata strains were completely shut down in response to the challenges by the probiotic lactobacilli strains. In addition, both probiotic lactobacilli strains exhibited strong autoaggregation and coaggregation phenotypes in the presence of C. glabrata, which indicate that these lactobacilli strains may exert their probiotic effects through the formation of aggregates and, thus the consequent prevention of colonization by C. glabrata.
Probiotic Lact. rhamnosus GR-1 and Lact. reuteri RC-14 strains exhibited potent antagonistic activities against all of the tested C. glabrata strains. These lactobacilli exhibited antifungal effects, including those attributed to their aggregation abilities, and their presence caused the cessation of growth and eventual cell death of C. glabrata.
Significance and Impact of the Study
This is the first study to report on the antagonistic effects of these probiotic lactobacilli strains against the non-Candida albicans Candida (NCAC) species C. glabrata.
antifungal; Candida glabrata; Lactobacillus reuteri RC-14; Lactobacillus rhamnosus GR-1; probiotic; vulvovaginal candidiasis
The aim of this study was to investigate the colonisation by lactobacilli and clinical outcome in women with bacterial vaginosis (BV) and recurrent vulvovaginal candidiasis (R-VVC) receiving antibiotic or anti-fungal treatment in combination with the probiotic EcoVag® capsules.
A total of 40 Scandinavian women diagnosed with BV or VVC on the basis of Amsel’s criteria or clinical symptoms were consecutively recruited in two pilot open label clinical trials. In trial I, women with BV were treated with clindamycin and metronidazole followed by vaginal EcoVag® capsules, containing Lactobacillus rhamnosus DSM 14870 and Lactobacillus gasseri DSM 14869, for 5 consecutive days after each antibiotic treatment. In trial II, women were recruited in three groups as follows: women with BV receiving clindamycin and metronidazole treatment together with a prolonged administration of EcoVag® (10 consecutive days after each antibiotic treatment followed by weekly administration of capsules for next four months), women with R-VVC receiving extended fluconazole and EcoVag® treatment, and women receiving extended fluconazole treatments only. The difference in frequency of isolation of EcoVag® strains or other lactobacilli between groups was compared by Fisher’s exact test.
The 6-month cure rate for BV was 50 % in trial I while both the 6- and 12-month cure rates were 67 % in trial II. The 6- and 12-month cure rates for VVC were 100 % and 89 % in women receiving fluconazole and EcoVag®, and 100 % and 70 % in women receiving fluconazole only. The frequency of isolation of any Lactobacillus species during the course of the study was associated with cure of BV in trial I and II, whereas the frequency of isolation of EcoVag® strains was significantly associated with the cure of BV in trial II only. As previously observed, a change in sexual partner was associated with relapse of BV with an Odds ratio of 77 (95 % CI: 2.665 to 2225).
The study suggests that the treatment with antibiotics or anti-fungal medication in combination with EcoVag® capsules provide long-term cure against BV and R-VVC as compared to previous reports.
ClinicalTrials.gov NCT02295579. Registered November 20, 2014
Electronic supplementary material
The online version of this article (doi:10.1186/s12879-015-0971-3) contains supplementary material, which is available to authorized users.
Bacterial vaginosis; Vulvovaginal candidiasis; Probiotic; Lactobacilli; Metronidazole; Clindamycin; Fluconazole
Vaginal epithelial cells have receptors, signal transduction mechanisms, and cytokine secretion capabilities to recruit host defenses against Candida albicans infections. This research evaluates how probiotic lactobacilli affect the defensive epithelial response.
This study used quantitative reverse transcription-polymerase chain reaction assay (qRT-PCR), flow cytometry, and a multiplex immunoassay to observe changes in the regulation of gene expression related to cytokine responses in the VK2 (E6/E7) vaginal epithelial cell line treated with 17β-estradiol, exposed to probiotic Lactobacillus rhamnosus GR-1® and Lactobacillus reuteri RC-14® and challenged with C. albicans. Data were statistically evaluated by repeated measures analysis of variance and paired t-tests where appropriate.
C. albicans induced mRNA expression of genes related to inflammatory cytokine responses associated with nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signal transduction pathways. 17β-estradiol suppressed expression of interleukin-1α (IL-1α), IL-6, IL-8, and tumor necrosis factor alpha (TNFα) mRNA. Probiotic lactobacilli suppressed C. albicans-induced nuclear factor-kappa B inhibitor kinase kinase alpha (Iκκα), Toll-like receptor-2 (TLR2), TLR6, IL-8, and TNFα, also suggesting inhibition of NF-κB signaling. The lactobacilli induced expression of IL-1α, and IL-1β mRNA, which was not inhibited by curcumin, suggesting that they induce an alternate inflammatory signal transduction pathway to NF-κB, such as the mitogen activated protein kinase and activator protein-1 (MAPK/AP-1) signal transduction pathway. Curcumin inhibited IL-13 secretion, suggesting that expression of this cytokine is mainly regulated by NF-κB signaling in VK2 cells.
The results suggest that C. albicans infection induces pro-inflammatory responses in vaginal epithelial cells, and estrogen and lactobacilli suppress expression of NF-κB-related inflammatory genes. Probiotic lactobacilli may induce IL-1α and IL-1β expression by an alternate signal transduction pathway, such as MAPK/AP-1. Activation of alternate signaling mechanisms by lactobacilli to modify epithelial cell cytokine production may be a mechanism for probiotic modulation of morbidity in vulvovaginal candidiasis.
Probiotic; Epithelial cells; Gene expression; Signal transduction genes; Candidiasis; Estrogen
Vulvovaginal Candidiasis (VVC) is a frequent, complex and cumbersome condition that can cause physical and psychological distress for the involved individual. Candida albicans was reported as the most common agent of VVC yet it seems that we are recently encountering changes in the pattern of Candida species in VVC.
In this study we assessed different species of Candida isolated from patients with VVC, residing in Sari, Iran.
Patients and Methods:
Two hundred and thirty-four patients with vulvovaginitis were enrolled in this study. Samples were collected by a wet swab. Each vaginal swab was examined microscopically and processed for fungal culture. The identification of Candida species was done by morphological and physiological methods such as culture on CHROMagar Candida media and sugar assimilation test with the HiCandida identification kit (HiMedia, Mumbai, India).
Out of 234 patients with vulvovaginitis, 66 (28.2%) patients showed VVC. Of these patients, 16 (24.2%) had recurrent VVC (RVVC). The age group of 20 - 29 year-olds had the highest frequency of VVC (48.5%). Erythema concomitant with itching (40.9%) was the most prevalent sign in VVC patients. Fifty-seven (86.4%) of the collected samples had positive results from both microscopic examination and culture. In total, 73 colonies of Candida spp. were isolated from 66 patients with VVC. The most common identified species of Candida were C. albicans (42.5%), C. glabrata (21.9%) and C. dubliniensis (16.4%). In patients with RVVC and patients without recurrence, C. albicans and non-albicans species of Candida were frequent species, respectively.
The results of our study showed that non-albicans species of Candida are more frequent than C. albicans in patients with VVC. This result is in line with some recent studies indicating that non-albicans species of Candida must be considered in gynecology clinics due to the reported azole resistance in these species.
Incidence; Candida; Vulvovaginal Candidiasis
The ability to tolerate Candida albicans, a human commensal of the gastrointestinal tract and vagina, implicates that host defense mechanisms of resistance and tolerance cooperate to limit fungal burden and inflammation at the different body sites. We evaluated resistance and tolerance to the fungus in experimental and human vulvovaginal candidiasis (VVC) as well as in recurrent VVC (RVVC). Resistance and tolerance mechanisms were both activated in murine VVC, involving IL-22 and IL-10-producing regulatory T cells, respectively, with a major contribution by the enzyme indoleamine 2,3-dioxygenase 1 (IDO1). IDO1 was responsible for the production of tolerogenic kynurenines, such that replacement therapy with kynurenines restored immunoprotection to VVC. In humans, two functional genetic variants in IL22 and IDO1 genes were found to be associated with heightened resistance to RVVC, and they correlated with increased local expression of IL-22, IDO1 and kynurenines. Thus, IL-22 and IDO1 are crucial in balancing resistance with tolerance to Candida, their deficiencies are risk factors for RVVC, and targeting tolerance via therapeutic kynurenines may benefit patients with RVVC.
This study disentangles resistance and tolerance components of murine and human C. albicans vaginal infection and introduces the challenging notion of a disease due to a defective tolerance mechanism. Vulvovaginal candidiasis (VVC) and recurrent VVC (RVVC) are two forms of disease that affect a large number of otherwise healthy women. Uncomplicated VVC is associated with several predisposing factors, whereas RVVC, marked by idiopathic recurrent episodes, may be virtually untreatable. Despite a growing list of recognized risk factors, further understanding of anti-Candida host defense mechanisms in the vagina is needed to optimize vaccine development and immune interventions to integrate with, or even replace, antifungal therapy. Indeed, medical treatments that increase host resistance, such as antifungals, are highly effective for individual symptomatic attacks but do not prevent recurrences and there is concern that repeated treatments might induce drug resistance. As tolerance mechanisms are not expected to have the same selective pressure on pathogens, new drugs that target tolerance will provide therapies to which low-virulence pathogens, such as C. albicans, will not develop resistance. This study provides a proof-of-concept that targeting tolerance via therapeutic kynurenines may benefit patients with RVVC.
Treatment of vulvovaginal candidiasis (VVC), caused most frequently by Candida albicans, represents a significant unmet clinical need. C. albicans, as both a commensal and a pathogenic organism, has a complex and poorly understood interaction with the vaginal environment. Understanding the complex nature of this relationship is necessary for the development of desperately needed therapies to treat symptomatic infection. Using transcriptome sequencing (RNA-seq), we characterized the early murine vaginal and fungal transcriptomes of the organism during VVC. Network analysis of host genes that were differentially expressed between infected and naive mice predicted the activation or repression of several signaling pathways that have not been previously associated with VVC, including NLRP3 inflammasome activation. Intravaginal challenge of Nlrp3−/− mice with C. albicans demonstrated severely reduced levels of polymorphonuclear leukocytes (PMNs), alarmins, and inflammatory cytokines, including interleukin-1β (IL-1β) (the hallmarks of VVC immunopathogenesis) in vaginal lavage fluid. Intravaginal administration of wild-type (WT) mice with glyburide, a potent inhibitor of the NLRP3 inflammasome, reduced PMN infiltration and IL-1β to levels comparable to those observed in Nlrp3−/− mice. Furthermore, RNA-seq analysis of C. albicans genes indicated robust expression of hypha-associated secreted aspartyl proteinases 4, 5, and 6 (SAP4–6), which are known inflammasome activators. Despite colonization similar to that of the WT strain, ΔSAP4–6 triple and ΔSAP5 single mutants induced significantly less PMN influx and IL-1β during intravaginal challenge. Our findings demonstrate a novel role for the inflammasome in the immunopathogenesis of VVC and implicate the hypha-associated SAPs as major C. albicans virulence determinants during vulvovaginal candidiasis.
Vaginitis, most commonly caused by the fungus Candida albicans, results in significant quality-of-life issues for all women of reproductive age. Recent efforts have suggested that vaginitis results from an immunopathological response governed by host innate immunity, although an explanatory mechanism has remained undefined. Using comprehensive genomic, immunological, and pharmacological approaches, we have elucidated the NLRP3 inflammasome as a crucial molecular mechanism contributing to host immunopathology. We have also demonstrated that C. albicans hypha-associated secreted aspartyl proteinases (SAP4–6 and SAP5, more specifically) contribute to disease immunopathology. Ultimately, this study enhances our understanding of the complex interplay between host and fungus at the vaginal mucosa and provides proof-of-principle evidence for therapeutic targeting of inflammasomes for symptomatic vulvovaginal candidiasis.
Four species of probiotic bacteria were assessed for their capacities to protect athymic bg/bg-nu/nu and euthymic bg/bg-nu/+ mice from mucosal and systemic candidiasis. Each bacterial species and Candida albicans colonized the gastrointestinal tracts of both strains of mice. The presence of probiotic bacteria (Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus casei GG, or Bifidobacterium animalis) in the gastrointestinal tracts prolonged the survival of adult and neonatal bg/bg-nu/nu mice compared to that of isogenic mice colonized with C. albicans alone. The incidence of systemic candidiasis in bg/bg-nu/nu mice was significantly reduced by each of the four probiotic bacterial species. The numbers of C. albicans present in the alimentary tracts of euthymic bg/bg-nu/+ mice were significantly reduced by L. casei GG and B. animalis. None of the probiotic bacteria species completely prevented mucosal candidiasis, but B. animalis reduced its incidence and severity. Probiotic bacteria also modulated antibody- and cell-mediated immune responses to C. albicans. The prolonged survival of mice, decreased severity of mucosal and systemic candidiasis, modulation of immune responses, decreased number of C. albicans in the alimentary tract, and reduced numbers of orogastric infections demonstrated not only that probiotic bacteria have biotherapeutic potential for prophylaxis against and therapy of this fungal disease but also that probiotic bacteria protect mice from candidiasis by a variety of immunologic (thymic and extrathymic) and nonimmunologic mechanisms in this model.
Vulvovaginal candidiasis (VVC) is one of the most common genital infections in women. The therapeutic arsenal remains restricted, and some alternatives to VVC treatment are being studied. The present study evaluated the influence of a propolis extractive solution (PES) on biofilm production by Candida albicans isolated from patients with VVC. Susceptibility testing was used to verify the minimum inhibitory concentration (MIC) of PES, with fluconazole and nystatin as controls. The biofilm formation of 29 vaginal isolates of C. albicans and a reference strain that were exposed to PES was evaluated using crystal violet staining. Colony-forming units were evaluated, proteins and carbohydrates of the matrix biofilm were quantified, and scanning electron microscopy was performed. The MIC of PES ranged from 68.35 to 546.87 μg/mL of total phenol content in gallic acid. A concentration of 546.87 μg/mL was able to cause the death of 75.8% of the isolates. PES inhibited biofilm formation by C. albicans from VVC. Besides antifungal activity, PES appears to present important antibiofilm activity on abiotic surfaces, indicating that it may have an additional beneficial effect in the treatment of VVC.
Saponin SC-2 from Solanum chrysotrichum showed antifungal activity, demonstrated in vitro, which inhibited the growth of dermatophytes, and in vivo, to be effective in the treatment against tinea pedis and pityriasis capitis. Fungistatic and fungicidal activity of saponin SC-2 on Candida albicans and other Candida species, fluconazole and ketoconazole resistaent strains was demostrated. SC-2-associated ultrastructural alterations in several Candida species were observed. An exploratory clinical, randomized, double-blind, and controlled ketoconazole study of ketoconazole was conducted with the aim of assessing the effectiveness and tolerability of an herbal medicinal product containing SC-2, on women with Vulvovaginal candidiasis (VVC). The results exhibited a percentage of therapeutic clinical effectiveness similar to that of ketoconazole (X2, p ≥0.30), but obtained a smaller percentage of mycological effectiveness, and 100% tolerability. In conclusion, saponin SC-2 possesses fungicidale and fungistatic activity on Candida albicans and other multi resistant Candida species, causes morphological changes and fungal death, and it is an alternative therapy for the treatment of VVC.
Solanum chrysotrichum; saponins; antifungal activity; vulvovaginal candidiasis; alternative therapy
Study of in vivo antifungal activity of the hydroalcoholic extract (HE) and n-BuOH extract (BUTE) of Sapindus saponaria against azole-susceptible and -resistant human vaginal Candida spp.
The in vitro antifungal activity of HE, BUTE, fluconazole (FLU), and itraconazole (ITRA) was determined by the broth microdilution method. We obtained values of minimal inhibitory concentration (MIC) and minimum fungicide concentration (MFC) for 46 strains of C. albicans and 10 of C. glabrata isolated from patients with vulvovaginal candidiasis (VVC). VVC was induced in hyperestrogenic Wistar rats with azole-susceptible C. albicans (SCA), azole-resistant C. albicans (RCA), and azole-resistant C. glabrata (RCG). The rats were treated intravaginally with 0.1 mL of HE or BUTE at concentrations of 1%, 2.5% and 5%; 100 μg/mL of FLU (treatment positive control); or distilled water (negative control) at 1, 24, and 48 h after induction of the infection, and the progress of VVC was monitored by culturing and scanning electron microscopy (SEM). The toxicity was evaluated in cervical cells of the HeLa cell line.
The extracts showed in vitro inhibitory and fungicidal activity against all the isolates, and the MIC and MFC values for the C. glabrata isolates were slightly higher. In vivo, the SCA, RCA, and RCG infections were eliminated by 21 days post-infection, with up to 5% HE and BUTE, comparable to the activity of FLU. No cytotoxic action was observed for either extract.
Our results demonstrated that HE and BUTE from S. saponaria show inhibitory and fungicidal activity in vitro, in addition to in vivo activity against azole-resistant vaginal isolates of C. glabrata and azole-susceptible and resistant isolates of C. albicans. Also considering the lack of cytotoxicity and the low concentrations of the extracts necessary to eliminate the infection in vivo, HE and BUTE show promise for continued studies with purified antifungal substances in VVC yeast isolates.
Sapindus saponaria; vaginal yeasts; antifungal activity; in vivo
Propolis, a resinous compound produced by Apis mellifera L. bees, is known to possess a variety of biological activities and is applied in the therapy of various infectious diseases. The aim of this study was to evaluate the in vitro antifungal activity of propolis ethanol extract (PE) and propolis microparticles (PMs) obtained from a sample of Brazilian propolis against clinical yeast isolates of importance in the vulvovaginal candidiasis (VVC). PE was used to prepare the microparticles. Yeast isolates (n = 89), obtained from vaginal exudates of patients with VVC, were exposed to the PE and the PMs. Moreover, the main antifungal drugs used in the treatment of VVC (Fluconazole, Voriconazole, Itraconazole, Ketoconazole, Miconazole and Amphotericin B) were also tested. Minimum inhibitory concentration (MIC) was determined according to the standard broth microdilution method. Some Candida albicans isolates showed resistance or dose-dependent susceptibility for the azolic drugs and Amphotericin B. Non-C. albicans isolates showed more resistance and dose-dependent susceptibility for the azolic drugs than C. albicans. However, all of them were sensitive or dose-dependent susceptible for Amphotericin B. All yeasts were inhibited by PE and PMs, with small variation, independent of the species of yeast. The overall results provided important information for the potential application of PMs in the therapy of VVC and the possible prevention of the occurrence of new symptomatic episodes.
Probiotic bacteria are suggested to play a role in the maintenance of oral health. Such health promoting bacteria are added to different commercial probiotic products. The aim of the study was to investigate the ability of a selection of lactobacilli strains, used in commercially available probiotic products, to inhibit growth of oral mutans streptococci and C. albicans in vitro.
Eight probiotic lactobacilli strains were tested for growth inhibition on three reference strains and two clinical isolates of mutans streptococci as well as two reference strains and three clinical isolates of Candida albicans with an agar overlay method.
At concentrations ranging from 109 to 105 CFU/ml, all lactobacilli strains inhibited the growth of the mutans streptococci completely with the exception of L. acidophilus La5 that executed only a slight inhibition of some strains at concentrations corresponding to 107 and 105 CFU/ml. At the lowest cell concentration (103 CFU/ml), only L. plantarum 299v and L. plantarum 931 displayed a total growth inhibition while a slight inhibition was seen for all five mutans streptococci strains by L. rhamnosus LB21, L. paracasei F19, L. reuteri PTA 5289 and L. reuteri ATCC 55730. All the tested lactobacilli strains reduced candida growth but the effect was generally weaker than for mutans streptococci. The two L. plantarum strains and L. reuteri ATCC 55730 displayed the strongest inhibition on Candida albicans. No significant differences were observed between the reference strains and the clinical isolates.
The selected probiotic strains showed a significant but somewhat varying ability to inhibit growth of oral mutans streptococci and Candida albicans in vitro.
Vulvovaginal candidiasis (VVC) in HIV-infected women contributed to the impairment
of their quality of life. The aim of this study was to evaluate the effect of highly
active antiretroviral therapy (HAART) use on the vaginal Candida
spp. isolation in HIV-infected compared to HIV-uninfected women. This cross-sectional
study included 178 HIV-infected (HIV group) and 200 HIV-uninfected women (control)
that were studied at the Specialized Assistance Service (SAE) for sexually
transmitted diseases (STD)/AIDS of the city of Maringá, Brazil, from April 1 to
October 30, 2011. The yeasts were isolated and identified by phenotypic and molecular
methods. The in vitro antifungal susceptibility to fluconazole,
itraconazole, nystatin and amphotericin B was tested by the reference microdilution
method. Higher frequencies of total vaginal Candida spp. isolation
were found in the HIV-infected group than in the control group. However, both groups
showed a similar frequency of colonization and VVC. Although C.
albicans was the most frequent and sensitive to azolics and polyenes in
both HIV-infected and uninfected women, the emerging resistance of C.
glabrata to amphotericin B in the HIV-infected women was observed.
Although higher frequency of vaginal Candida spp. isolation had been
observed in the HIV-infected than in HIV-uninfected women, colonization and VVC
showed similar frequency in both groups, indicating that HAART appears to protect
against vaginal colonization and VVC.
Vulvovaginal candidiasis (VVC) remains a common cause of morbidity, with three-quarters of women affected during their lifetimes. Use of antibiotics is an acknowledged trigger for VVC, which adversely affects women's physical and emotional health. Knowledge of patterns of genital Candida species-level identification is important for management, as Candida species other than Candida albicans often fail first-line treatment. A community sample of women with no vaginal symptoms, and who were prescribed antibiotics, was recruited into this study, where the incidence of genital colonization by various Candida species was documented, as well as symptoms of VVC plus relevant associations, before and after treatment with antibiotics. Self-collected low vaginal swabs were taken prior to and 8 days after completion of antibiotic treatment, and data on various potential risk factors for VVC were collected simultaneously, with complete data being available for 233 participants. Baseline Candida species colonization was present in 21% of women (95% confidence intervals [CI], 17% to 27%), rising to 37% (95% CI, 31% to 44%) after antibiotic treatment. The primary species detected for either period was C. albicans (73%), with Candida glabrata detected in around 20%. Self-assessed proneness to VVC after antibiotic treatment and baseline colonization with Candida spp. were significantly associated with symptomatic VVC after antibiotic treatment. For microbiologically proven candidiasis, VVC symptoms had a sensitivity of 57% and a specificity of 91%. When physicians prescribe antibiotics, the history of risk of VVC is one issue that physicians should discuss with women, particularly those who are self-identified as being prone to VVC. Furthermore, we recommend that definitive microbiological diagnoses be made for women with recurrent symptoms or those failing initial treatment, to guide appropriate therapy.
Background: Vaginal candidiasis is a common gynecological finding among women worldwide. This study was carried out to determine the prevalence of vulvovaginal candidiasis (VVC) along with speciation of Candida with special reference to its antifungal susceptibility pattern to fluconazole and also to evaluate the risk factors responsible for VVC in patients attending our tertiary care hospital in Puducherry, India.
Materials and Methods: This study was carried out in the tertiary care hospital in Puducherry during the period of August 2010 to September 2012.The study group consisted of 180 women between the age group of 15 to 56 years with the complaints of excessive vaginal discharge, pruritis and pain. Materials used for this study consisted of high vaginal swabs from patients with relevant history, attending Obstetrics & Gynecology department. High vaginal swabs were subjected to direct 10% KOH wet mount microscopy, Gram stain, culture onto Sabouraud’s dextrose agar (SDA) & 5% sheep blood agar and susceptibility testing to fluconazole was performed using E-test.
Candida was isolated in 40 (22.2 %) women & these consisted of C. albicans 26 (65%), C. glabrata 9 (22.5%), C.tropicalis 3 (7.5%) & C. parapsilosis 2 (5%). Susceptibility test carried out on the 40 isolates revealed that 35 (87.5%) Candida isolates were sensitive to fluconazole, 3 (7.5%) were moderately sensitive and 2 (2.5%) were resistant. Thirty one percent patients had itching as the presenting complaints followed by vaginal discharge (29.4%).
Conclusion: The high frequency with which C. albicans was recovered in our study and its susceptibility to fluconazole supports the continued use of azole agents for empirical therapy of uncomplicated candidal vulvovaginitis in the community.
Candidiasis; Vulvovaginitis; Candida; Vulvovaginal candidiasis
Recent studies have suggested that the topical application of probiotic bacteria can improve skin health or combat disease. We have utilized a primary human keratinocyte culture model to investigate whether probiotic bacteria can inhibit Staphylococcus aureus infection. Evaluation of the candidate probiotics Lactobacillus reuteri ATCC 55730, Lactobacillus rhamnosus AC413, and Lactobacillus salivarius UCC118 demonstrated that both L. reuteri and L. rhamnosus, but not L. salivarius, reduced S. aureus-induced keratinocyte cell death in both undifferentiated and differentiated keratinocytes. Keratinocyte survival was significantly higher if the probiotic was applied prior to (P < 0.01) or simultaneously with (P < 0.01) infection with S. aureus but not when added after infection had commenced (P > 0.05). The protective effect of L. reuteri was not dependent on the elaboration of inhibitory substances such as lactic acid. L. reuteri inhibited adherence of S. aureus to keratinocytes by competitive exclusion (P = 0.026). L. salivarius UCC118, however, did not inhibit S. aureus from adhering to keratinocytes (P > 0.05) and did not protect keratinocyte viability. S. aureus utilizes the α5β1 integrin to adhere to keratinocytes, and blocking of this integrin resulted in a protective effect similar to that observed with probiotics (P = 0.03). This suggests that the protective mechanism for L. reuteri-mediated protection of keratinocytes was by competitive exclusion of the pathogen from its binding sites on the cells. Our results suggest that use of a topical probiotic prophylactically could inhibit the colonization of skin by S. aureus and thus aid in the prevention of infection.
Vulvovaginal candidiasis (VVC) is an opportunistic mucosal infection caused by Candida albicans that affects large numbers of otherwise healthy women of childbearing age. Acute episodes of VVC often occur during pregnancy and during the luteal phase of the menstrual cycle, when levels of progesterone and estrogen are elevated. Although estrogen-dependent experimental rodent models of C. albicans vaginal infection are used for many applications, the role of reproductive hormones and/or their limits in the acquisition of vaginal candidiasis remain unclear. This study examined the effects of estrogen and progesterone on several aspects of an experimental infection together with relative cell-mediated immune responses. Results showed that while decreasing estrogen concentrations eventually influenced infection-induced vaginal titers of C. albicans and rates of infection in inoculated animals, the experimental infection could not be achieved in mice treated with various concentrations of progesterone alone. Furthermore, progesterone had no effect on (i) the induction and persistence of the infection in the presence of estrogen, (ii) delayed-type hypersensitivity in primary-infected mice, or (iii) the partial protection from a secondary vaginal infection under pseudoestrus conditions. Other results with estrogen showed that a persistent infection could be established with a wide range of C. albicans inocula under supraphysiologic and near-physiologic (at estrus) concentrations of estrogen and that vaginal fungus titers or rates of infection were similar if pseudoestrus was initiated several days before or after inoculation. However, the pseudoestrus state had to be maintained for the infection to persist. Finally, estrogen was found to reduce the ability of vaginal epithelial cells to inhibit the growth of C. albicans. These results suggest that estrogen, but not progesterone, is an important factor in hormone-associated susceptibility to C. albicans vaginitis.
The composition of the vaginal microbiota is known to be important for health. When infections occur, antimicrobial therapy is often poorly efficacious.
Objective and design
We used 16S rRNA gene sequencing to characterize changes in the bacterial microbiota following oral antimicrobial and probiotic interventions.
While the bacterial vaginal profiles of women with vulvovaginal candidiasis were dominated by lactobacilli as in healthy women, and unchanged by therapy, Gardnerella vaginalis, Prevotella, Atopobium, Sneathia, and Megasphaera dominated the vagina of women with bacterial vaginosis (BV), and treatment with tinidazole plus Lactobacillus reuteri RC-14+L. rhamnosus GR-1 resulted in an increased relative abundance of indigenous L. iners or L. crispatus.
The ability to restore homeostasis provides a rationale for conjoint use of probiotics with antibiotic treatment of BV.
Lactobacillus; bacterial vaginosis; vulvovaginal candidiasis; probiotics
The treatment of vulvovaginal candidiasis (VVC) due to Candida glabrata is challenging, with limited therapeutic options. Unexplained disappointing clinical efficacy has been reported with systemic and topical azole antifungal agents in spite of in vitro susceptibility. Given that the vaginal pH of patients with VVC is unchanged at 4 to 4.5, we studied the effect of pH on the in vitro activity of 11 antifungal agents against 40 C. glabrata isolates and compared activity against 15 fluconazole-sensitive and 10 reduced-fluconazole-susceptibility C. albicans strains. In vitro susceptibility to flucytosine, fluconazole, voriconazole, posaconazole, itraconazole, ketoconazole, clotrimazole, miconazole, ciclopirox olamine, amphotericin B, and caspofungin was determined using the CLSI method for yeast susceptibility testing. Test media were buffered to pHs of 7, 6, 5, and 4. Under conditions of reduced pH, C. glabrata isolates remained susceptible to caspofungin and flucytosine; however, there was a dramatic increase in the MIC90 for amphotericin B and every azole drug tested. Although susceptible to other azole drugs tested at pH 7, C. albicans strains with reduced fluconazole susceptibility also demonstrated reduced susceptibility to amphotericin B and all azoles at pH 4. In contrast, fluconazole-sensitive C. albicans isolates remained susceptible at low pH to azoles, in keeping with clinical observations. In selecting agents for treatment of recurrent C. glabrata vaginitis, clinicians should recognize the limitations of in vitro susceptibility testing utilizing pH 7.0.
Lactic acid bacteria are considered important probiotics for prevention of some infections. The aim of this work was to investigate the effect of selenium dioxide on the antifungal activity of Lactobacillus plantarum and L. johnsonii against Candida albicans.
Lactobacillus plantarum and L. johnsonii cells, grown in the presence and absence of selenium dioxide, and their cell-free spent culture media were tested for antifungal activity against C. albicans ATCC 14053 by a hole-plate diffusion method and a time-kill assay.
Both L. plantarum and L. johnsonii reduced selenium dioxide to cell-associated elemental selenium nanoparticles. The cell-free spent culture media, from both Lactobacillus species that had been grown with selenium dioxide for 48 h, showed enhanced antifungal activity against C. albicans. Enhanced antifungal activity of cell biomass against C. albicans was also observed in cultures grown with selenium dioxide.
Selenium dioxide-treated Lactobacillus spp. or their cell-free spent broth inhibited the growth of C. albicans and should be investigated for possible use in anti-Candida probiotic formulations in future.
Candida albicans; Secretory products; Selenium nanoparticles; Antimicrobial effect; Lactobacillus plantarum; Lactobacillus johnsonii
Objective. Candida krusei causes approximately 1% of vulvovaginal candidiasis (VVC) cases and is naturally resistant to fluconazole. Antifungal testing may be required if C. krusei vaginitis fails to respond to non-fluconazole therapy, particularly in patients with recurrent infections. Design. We investigated the clinical characteristics and antifungal susceptibility profile of vaginal C. krusei isolates. Between 2009 and 2012, we identified 560 unrelated Candida spp.-positive vaginal cultures, of which 28 (5.0%) were C. krusei. These isolates were analyzed according to host factors and the clinical forms of VVC, and their in vitro susceptibility to 10 antifungal agents was tested using a reference microdilution method. Results. We observed that perineal laceration and increased age (>50 years) were significant predictors of C. krusei in vaginal samples (P < 0.05). All isolates were susceptible to amphotericin B, caspofungin, ketoconazole, and miconazole. Additionally, susceptible dose-dependent and resistant rates were found for fluconazole as 42.9% and 57.1%, respectively. Remarkably, only 42.9% and 67.9% of the isolates were susceptible to itraconazole and voriconazole, respectively. Conclusions. Understanding local susceptibility patterns, especially those of non-C. albicans Candida species, can significantly aid in the selection of an effective antifungal agent. The in vivo response of C. krusei vaginitis to various antifungal therapeutics remains unknown and requires further research.
Candida albicans is the causative agent of acute and recurrent vulvovaginal candidiasis (VVC), a common mucosal infection affecting significant numbers of women in their reproductive years. While any murine host protective role for cell-mediated immunity (CMI), humoral immunity, and innate resistance by neutrophils against the vaginal infection appear negligible, significant in vitro growth inhibition of Candida species by vaginal and oral epithelial cell-enriched cells has been observed. Both oral and vaginal epithelial cell anti-Candida activity has a strict requirement for cell contact to C. albicans with no role for soluble factors, and oral epithelial cells inhibit C. albicans through a cell surface carbohydrate moiety. The present study further evaluated the inhibitory mechanisms by murine vaginal epithelial cells and the fate of C. albicans by oral and vaginal epithelial cells. Similar to human oral cells, anti-Candida activity produced by murine vaginal epithelial cells is unaffected by enzymatic cleavage of cell surface proteins and lipids but sensitive to periodic acid cleavage of surface carbohydrates. Analysis of specific membrane carbohydrate moieties, however, showed no role for sulfated polysaccharides, sialic acid residues, or glucose and mannose-containing carbohydrates, also similar to oral cells. Staining for live and dead Candida in the coculture with fluorescein diacetate (FDA) and propidium iodide (PI), respectively, showed a clear predominance of live organisms, suggesting a static rather than cidal action. Together, the results suggest that oral and vaginal epithelial cells retard or arrest the growth rather than kill C. albicans through an as-yet-unidentified carbohydrate moiety in a noninflammatory manner.
Objectives: To evaluate point prevalence vaginal yeast colonisation and symptomatic vaginitis in middle adolescents and to identify relation of these yeast conditions with reproductive hormones, sexual activity, sexual behaviours, and associated local immunity.
Methods: Middle adolescent females (n = 153) were evaluated for sexually transmitted infections (STIs), asymptomatic yeast colonisation, and symptomatic vulvovaginal candidiasis (VVC) by standard criteria. Also evaluated were local parameters, including vaginal associated cytokines, chemokines, and antibodies, vaginal epithelial cell antifungal activity, and Candida specific peripheral blood lymphocyte responses. Correlations between yeast colonisation/vaginitis and local immunomodulators, reproductive hormones, douching, sexual activity, condom use, and STIs were identified.
Results: Rates of point prevalence asymptomatic yeast colonisation (22%) were similar to adults and similarly dominated by Candida albicans, but with uncharacteristically high vaginal yeast burden. In contrast with the high rate of STIs (18%), incidence of symptomatic VVC was low (<2%). Immunological properties included high rates of Candida specific systemic immune sensitisation, a Th2 type vaginal cytokine profile, total and Candida specific vaginal antibodies dominated by IgA, and moderate vaginal epithelial cell anti-Candida activity. Endogenous reproductive hormones were in low concentration. Sexual activity positively correlated with vaginal yeast colonisation, whereas vaginal cytokines (Th1, Th2, proinflammatory), chemokines, antibodies, contraception, douching, or condom use did not.
Conclusion: Asymptomatic vaginal yeast colonisation in adolescents is distinct in some ways with adults, and positively correlates with sexual activity, but not with local immunomodulators or sexual behaviours. Despite several factors predictive for VVC, symptomatic VVC was low compared to STIs.
BACKGROUND: It is estimated that as many as 13 million cases of vulvovaginal infection occur in the United States annually, the majority of which are the result of Candida albicans infection. The symptoms of vulvovaginal infections are often painful and distressing to the patient. The objective of this study was to compare the time to symptomatic relief of vulvovaginal candidiasis (VVC) with butoconazole nitrate 2% Site Release vaginal cream (Gynazole-1) and oral fluconazole 150 mg tablets (Diflucan). METHODS: This randomized, open-label, parallel study evaluated 181 female patients with moderate to severe symptoms of VVC. Patients were randomized to single-dose therapy with either butoconazole nitrate 2% Site Release vaginal cream or fluconazole. The primary outcome measure was the time to onset of first relief of symptoms. Secondary measures included the time to overall relief of symptoms and the reinfection rate over the first 30 days following treatment. The overall safety of both products was investigated through the collection of adverse event reports. RESULTS: The median time to first relief of symptoms occurred at 17.5 h for butoconazole patients as compared to 22.9 h for fluconazole patients (p < 0.001). The time at which 75% of patients experienced first relief of symptoms was 24.5 h versus 46.3 h for butoconazole and fluconazole, respectively (p < 0.001). By 12- and 24-h post-treatment, 44.4% and 72.8% of patients in the butoconazole treatment group reported first relief of symptoms versus 29.1% and 55.7% of patients in the fluconazole group (p = 0.044 and p = 0.024 respectively). In patients experiencing first relief of symptoms within 48 h of dosing, the median time to first relief of symptoms in the butoconazole treatment group was significantly shorter at 12.9 h compared to 20.7 h for the fluconazole treatment group (p = 0.048). There were no significant differences between the two groups with respect to time to total relief of symptoms or reoccurrence of infection within 30 days of treatment. Butoconazole therapy was shown to have fewer reported adverse events, including drug-related adverse events, than fluconazole therapy. Vulvovaginal pruritis and vulvovaginal burning were the most common drug-related adverse events attributed to butoconazole. Headache, diarrhea, nausea, upset stomach and skin sensitivity were the most common drug-related adverse events attributable to fluconazole. CONCLUSIONS: Single-dose butoconazole nitrate 2% Site Release vaginal cream provides statistically significant improvement in time to first relief of symptoms in the treatment of VVC compared to fluconazole. There is no difference between these two treatments with respect to total relief of symptoms or reinfection rate. Although there was no significant difference in the incidence of adverse events judged by the investigator to be treatment-related, butoconazole treatment did result in fewer patients experiencing adverse events than fluconazole.
Epithelial cells of the urinary tract recognize pathogenic bacteria through pattern recognition receptors on their surface, such as toll-like receptors (TLRs), and mount an immune response through the activation of the NF-kappaB pathway. Some uropathogenic bacteria can subvert these cellular responses, creating problems with how the host eliminates pathogens. Lactobacillus is a genus of lactic acid bacteria that are part of the microbiota and consist of many probiotic strains, some specifically for urogenital infections. Immunomodulation has emerged as an important mode of action of probiotic and commensal lactobacilli and given the importance of epithelial cells, we evaluated the effect of the urogenital probiotic Lactobacillus rhamnosus GR-1 on epithelial immune activation.
Immune activation through the NF-kappaB pathway was initiated by stimulation of T24 urothelial cells with heat-killed Escherichia coli and this was further potentiated when cells were co-cultured with live L. rhamnosus GR-1. Heat-killed lactobacilli were poor activators of NF-kappaB. Concomitant stimulation of bladder cells with E. coli and L. rhamnosus GR-1 increased the levels of the pro-inflammatory cytokine TNF, whereas IL-6 and CXCL8 levels were reduced. Another probiotic, L. rhamnosus GG, was also able to potentiate NF-kappaB in these cells although at a significantly reduced level compared to the GR-1 strain. The transcript numbers and protein levels of the lipopolysaccharide receptor TLR4 were significantly increased after co-stimulation with E. coli and lactobacilli compared to controls. Furthermore, inhibition of TLR4 activation by polymixin B completely blocked the lactobacilli potentiation of NF-kappaB.
The immunological outcome of E. coli challenge of bladder cells was influenced by probiotic L. rhamnosus GR-1, by enhancing the activation of NF-kappaB and TNF release. Thus the urogenital probiotic L. rhamnosus GR-1 modulated the activation of the NF-kappaB through increased levels of TLR4 on the bladder cells and altered subsequent release of cytokines from urothelial cells. By influencing immunological factors such as TLR4, important in the process of fighting pathogens, lactobacilli could facilitate pathogen recognition and infection clearance.