An Update on the Roles of Non-albicans Candida Species in Vulvovaginitis

Prevalence of Oropharyngeal Candidiasis and distribution of Candida species among People Living with Human Immunodeficiency Virus in Africa: a systematic review and meta-analysis

Background

The incidence of oropharyngeal candidiasis among people living with human immunodeficiency virus in Africa is on the rise. Oropharyngeal candidiasis is mainly caused by C.albicans; however, a shift in the etiology towards non-Candida albicans species is increasing. In addition, there are variations in the epidemiological distribution of Candida species causing oropharyngeal candidiasis among people living with human immunodeficiency virus in Africa.

Objective

This review aimed to determine the prevalence of oropharyngeal candidiasis and the distribution of Candida species among people living with human immunodeficiency virus in Africa.

Materials and Methods

This systematic review protocol was registered in the base PROSPERO database prior to its conduct (CRD42021254473). The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol guidelines (PRISMA-P) were followed for this study. The PubMed, Scopus and EMBASE databases were searched to identify published studies published between 1st January 2000 and 8th October 2022. The eligible studies were included in the meta-analysis and analyzed using a random effects model. The risk of bias of the included studies was assessed using the Joanna Briggs Institute quality assessment tool for prevalence studies.

Results

The database search yielded 370 titles from PubMed (n=192), EMBASE (n=162) and SCOPUS (n=16). Fourteen studies with a total of 3,863 participants were included in the meta-analysis. The pooled prevalence of oropharyngeal candidiasis was 49.0% (95% CI: 37% - 62%). A total of 2,688 Candida isolates were reported; approximately 76.6% (n=2,060) were C. albicans, and 21.7% (n=582) were non-C. albicans. Among the non-Candida albicans species, C. glabrata was the most common isolate (29.6%), followed by C. tropicalis (27.7%), C. krusei (17.0%), C. parapsilosis (8.1%) and C. dubliniensis (5.2%). Out of 14 studies, 7 (50.0%) had a low risk of bias, 5 (35.7%) had a moderate risk of bias, and 2 (14.3%) had a high risk of bias.

Conclusion

Almost half of people living with HIV in Africa have oropharyngeal candidiasis, and C. albicans remains the most frequent cause of oropharyngeal candidiasis.

Treatment of vaginitis caused by non-albicans Candida species

INTRODUCTION

In the face of increased frequency of non-albicans Candida vulvovaginitis (VVC) reported worldwide, there is a paucity of effective oral and topical antifungal drugs available. Drug selection is further handicapped by an absence of data of clinical efficacy of available antifungal drugs for these infections.

AREAS COVERED

In this review, attention is directed at the cause of drug shortage as well as increased frequency of non-albicans Candida (NAC) vulvovaginitis. There is widespread recognition of reduced in vitro azole drug susceptibility in NAC species. Moreover, antifungal susceptibility tests have not been standardized or validated for NAC isolates, hence clinicians rely on an element of empiricism especially given the absence of randomized controlled comparative studies targeting NAC species. Clinical spectrum of NAC species isolates is highly variable with ongoing difficulty in determining a causal role in symptomatic patients.

EXPERT OPINION

We have entered the era of demand for Candida species-specific therapy and although consensus treatment guidelines are emerging, new antifungal agents that target these multiple-azole resistant or relatively resistant vaginal NAC species are urgently needed.

Nanobody-mediated neutralization of candidalysin prevents epithelial damage and inflammatory responses that drive vulvovaginal candidiasis pathogenesis

Candida albicans can cause mucosal infections in humans. This includes oropharyngeal candidiasis, which is commonly observed in human immunodeficiency virus infected patients, and vulvovaginal candidiasis (VVC), which is the most frequent manifestation of candidiasis. Epithelial cell invasion by C. albicans hyphae is accompanied by the secretion of candidalysin, a peptide toxin that causes epithelial cell cytotoxicity. During vaginal infections, candidalysin-driven tissue damage triggers epithelial signaling pathways, leading to hyperinflammatory responses and immunopathology, a hallmark of VVC. Therefore, we proposed blocking candidalysin activity using nanobodies to reduce epithelial damage and inflammation as a therapeutic strategy for VVC. Anti-candidalysin nanobodies were confirmed to localize around epithelial-invading C. albicans hyphae, even within the invasion pocket where candidalysin is secreted. The nanobodies reduced candidalysin-induced damage to epithelial cells and downstream proinflammatory responses. Accordingly, the nanobodies also decreased neutrophil activation and recruitment. In silico mathematical modeling enabled the quantification of epithelial damage caused by candidalysin under various nanobody dosing strategies. Thus, nanobody-mediated neutralization of candidalysin offers a novel therapeutic approach to block immunopathogenic events during VVC and alleviate symptoms.IMPORTANCEWorldwide, vaginal infections caused by Candida albicans (VVC) annually affect millions of women, with symptoms significantly impacting quality of life. Current treatments are based on anti-fungals and probiotics that target the fungus. However, in some cases, infections are recurrent, called recurrent VVC, which often fails to respond to treatment. Vaginal mucosal tissue damage caused by the C. albicans peptide toxin candidalysin is a key driver in the induction of hyperinflammatory responses that fail to clear the infection and contribute to immunopathology and disease severity. In this pre-clinical evaluation, we show that nanobody-mediated candidalysin neutralization reduces tissue damage and thereby limits inflammation. Implementation of candidalysin-neutralizing nanobodies may prove an attractive strategy to alleviate symptoms in complicated VVC cases.

Three cases of vulvovaginal candidiasis due to Candida nivariensis

Candida nivariensis is emerging as a highly resistant species of the Candida glabrata complex causing invasive and mucocutaneous infections. In this study, three cases of vulvovaginal candidiasis caused by C. nivariensis are described and identified by Internal Transcribed Spacer 1-2 sequencing. All isolates were susceptible in vitro to anidulafungin, micafungin, caspofungin, 5-flucytosine, posaconazole, voriconazole, itraconazole, amphotericin B, and showed dose-dependent susceptibility to fluconazole. In two patients, three doses of oral fluconazole were effective, while one patient developed clinical fluconazole resistance with a new relapse after 6 months. Increasing the weekly dose of fluconazole showed to be effective in this patient.

A Cyclam Salt as an Antifungal Agent: Interference with Candida spp. and Cryptococcus neoformans Mechanisms of Virulence

The importance of fungal infections, particularly those caused by yeasts, is increasing among the medical community. Candida albicans and Cryptococcus neoformans are amongst the high-priority fungal species identified by the World Health Organization (WHO) and are considered in the critical group, while Candida krusei is included in the medium-priority group. The cyclam salt H4[H2(4-CF3PhCH2)2Cyclam]Cl4 proved to be active against the growth of these three yeasts, and the aim of this work was to verify its interference with their virulence mechanisms, whether shared or unique. H4[H2(4-CF3PhCH2)2Cyclam]Cl4 significantly inhibited biofilm production and catalase activity, being able to interfere with C. albicans dimorphic transition and C. neoformans melanin production. At the minimal inhibitory concentration (MIC) values, H4[H2(4-CF3PhCH2)2Cyclam]Cl4 had no antioxidant effect, as determined by the DPPH method. When using the RAW264.7 macrophage cell line, H4[H2(4-CF3PhCH2)2Cyclam]Cl4 reduced nitric oxide (NO) detection (the Griess reaction), but this effect was associated with a significant toxic effect on the cells.

Oteseconazole versus fluconazole for the treatment of severe vulvovaginal candidiasis: a multicenter, randomized, double-blinded, phase 3 trial

Vulvovaginal candidiasis (VVC) is a common condition among women. Fluconazole remains the dominant treatment option for VVC. Oteseconazole is a highly selective inhibitor of fungal CYP51. This randomized, double-blinded, phase 3 trial was conducted to evaluate the efficacy and safety of oteseconazole compared with fluconazole in treating severe VVC. Female subjects presenting with vulvovaginal signs and symptoms score of ≥7 and positive Candida infection determined by potassium hydroxide test or Gram staining were randomly assigned to receive oteseconazole (600 mg on D1 and 450 mg on D2) or fluconazole (150 mg on D1 and D4) in a 1:1 ratio. The primary endpoint was the proportion of subjects achieving therapeutic cure [defined as achieving both clinical cure (absence of signs and symptoms of VVC) and mycological cure (negative culture of Candida species)] at D28. A total of 322 subjects were randomized and 321 subjects were treated. At D28, a statistically significantly higher proportion of subjects achieved therapeutic cure in the oteseconazole group than in the fluconazole group (66.88% vs 45.91%; P = 0.0002). Oteseconazole treatment resulted in an increased proportion of subjects achieving mycological cure (82.50% vs 59.12%; P < 0.0001) and clinical cure (71.25% vs 55.97%; P = 0.0046) compared with fluconazole. The incidence of treatment-emergent adverse events was similar between the two groups. No subjects discontinued study treatment or withdrew study due to adverse events. Oteseconazole showed statistically significant and clinically meaningful superiority over fluconazole for the treatment of severe VVC and was generally tolerated.

Biochanin A Inhibits the Growth and Biofilm of Candida Species

The aim of this study was to investigate the antifungal activity of biochanin A (BCA) against planktonic growth and biofilms of six Candida species, including C. albicans, C. parapsilosis, C. glabrata, C. tropicalis, C. auris, and C. krusei. We applied various assays that determined (a) the antimicrobial effect on growth of Candida species, (b) the effect on formation of hyphae and biofilm, (c) the effect on the expression of genes related to hyphal growth and biofilm formation, (d) the influence on cell wall structure, and (e) the effect on cell membrane integrity and permeability. Moreover, disk diffusion tests were used to investigate the effect of a combination of BCA with fluconazole to assess their possible synergistic effect on drug-resistant C. albicans, C. glabrata, and C. auris. Our results showed that the BCA MIC50 values against Candida species ranged between 125 µg/mL and 500 µg/mL, and the MIC90 values were in a concentration range from 250 µg/mL to 1000 µg/mL. The treatment with BCA inhibited adhesion of cells, cell surface hydrophobicity (CSH), and biofilm formation and reduced hyphal growth in all the analyzed Candida species. Real-time qRT-PCR revealed that BCA down-regulated the expression of biofilm-specific genes in C. albicans. Furthermore, physical destruction of C. albicans cell membranes and cell walls as a result of the treatment with BCA was observed. The combination of BCA and fluconazole did not exert synergistic effects against fluconazole-resistant Candida.

Candida parapsilosis complex in the clinical setting

Representatives of the Candida parapsilosis complex are important yeast species causing human infections, including candidaemia as one of the leading diseases. This complex comprises C. parapsilosis, Candida orthopsilosis and Candida metapsilosis, and causes a wide range of clinical presentations from colonization to superficial and disseminated infections with a high prevalence in preterm-born infants and the potential to cause outbreaks in hospital settings. Compared with other Candida species, the C. parapsilosis complex shows high minimal inhibitory concentrations for echinocandin drugs due to a naturally occurring FKS1 polymorphism. The emergence of clonal outbreaks of strains with resistance to commonly used antifungals, such as fluconazole, is causing concern. In this Review, we present the latest medical data covering epidemiology, diagnosis, resistance and current treatment approaches for the C. parapsilosis complex. We describe its main clinical manifestations in adults and children and highlight new treatment options. We compare the three sister species, examining key elements of microbiology and clinical characteristics, including the population at risk, disease manifestation and colonization status. Finally, we provide a comprehensive resource for clinicians and researchers focusing on Candida species infections and the C. parapsilosis complex, aiming to bridge the emerging translational knowledge and future therapeutic challenges associated with this human pathogen.

Effect of various concentrations of common organic solvents on the growth and proliferation ability of Candida glabrata and their permissible limits for addition in drug susceptibility testing

Objectives

Dimethyl sulfoxide (DMSO), acetone, ethanol, and methanol are organic solvents commonly used for dissolving drugs in antimicrobial susceptibility testing. However, these solvents have certain antimicrobial activity. Currently, standardized criteria for the selection and dosage of drug solvents in drug susceptibility testing research are lacking. The study aims to provide experimental evidence for the selection and addition limit of drug solvents for the in vitro antifungal susceptibility test of Candida glabrata (C. glabrata).

Methods

According to the recommendation of the Clinical and Laboratory Standards Institute (CLSI) M27-A3, a 0.5 McFarland C. glabrata suspension was prepared and then diluted 1:1,000. Next, a gradient dilution method was used to prepare 20%, 10%, 5%, and 2.5% DMSO/acetone/ethanol/methanol. The mixture was plated onto a 96-well plate and incubated at a constant temperature of 35 °C for 48 h. The inhibitory effects of DMSO, acetone, ethanol, and methanol on C. glabrata growth and proliferation were analyzed by measuring optical density values at 600 nm (OD600 values).

Results

After 48 h incubation, the OD600 values of C. glabrata decreased to different extents in the presence of the four common organic solvents. The decrease in the OD600 values was greater with increasing concentrations within the experimental concentration range. When DMSO and acetone concentrations were higher than 2.5% (containing 2.5%) and methanol and ethanol concentrations were higher than 5.0% (containing 5.0%), the differences were statistically significant compared with the growth control wells without any organic solvent (P < 0.05).

Conclusion

All four organic solvents could inhibit C. glabrata growth and proliferation. When used as solvents for drug sensitivity testing in C. glabrata, the concentrations of DMSO, acetone, ethanol, and methanol should be below 2.5%, 2.5%, 5%, and 5%, respectively.

Antifungal Activity and Type of Interaction of Melissa officinalis Essential Oil with Antimycotics against Biofilms of Multidrug-Resistant Candida Isolates from Vulvovaginal Mucosa

(1) Background: Vulvovaginal candidosis (VVC) is a major therapy issue due to its high resistance rate and virulence factors such as the ability to form biofilms. The possibility of combining commonly used antifungals with natural products might greatly improve therapeutic success. (2) Methods: A total of 49 vulvovaginal isolates, causative agents of recurrent VVC, were tested for their susceptibility to fluconazole, nystatin, and Melissa officinalis essential oil (MOEO). This examination included testing the antibiofilm potential of antifungals and MOEO and the determination of their types of interaction with mature biofilms. (3) Results: Antimicrobial testing showed that 94.4% of the Candida albicans isolates and all the Candida krusei isolates were resistant to fluconazole, while all strains showed resistance to nystatin. The same strains were susceptible to MOEO in 0.156-2.5 mg/mL concentrations. Additionally, the results revealed very limited action of fluconazole, while nystatin and MOEO reduced the amount of biofilm formed by as much as 17.7% and 4.6%, respectively. Testing of the combined effect showed strain-specific synergistic action. Furthermore, the lower concentrations exhibited antagonistic effects even in cases where synergism was detected. (4) Conclusions: This study showed that MOEO had a very good antibiofilm effect. However, combining MOEO with antimycotics demonstrated that the type of action depended on the choice of antifungal drugs as well as the applied concentration.

"Efficacy and safety of oteseconazole in recurrent vulvovaginal candidiasis (RVVC) - A systematic review and meta-analysis"

Background

Recurrent Vulvovaginal Candidiasis (RVVC) is defined as 3 or more episodes of symptomatic Vulvovaginal Candidiasis (VVC) within a year. Out of 75 % of women with VVC, this debilitating infection is experienced by 9 % of women. Although standard guidelines recommend oral and topical fluconazole as its treatment regimen, approval of another drug Oteseconazole has drawn the attention because of its better safety profile and lower recurrence rate by its use.

Aim

The purpose of our Meta-analysis is to evaluate the safety and efficacy of Oteseconazole (Vivjoa) (VT-1161) in the treatment of Recurrent Vulvovaginal Candidiasis (RVVC).

Methodology

Four databases namely PubMed, Google Scholar, Cochrane CENTRAL and Clinical Trial.gov were used from inception till June 2023. Studies that met the predefined inclusion criteria were statistically analyzed on RevMan (Version 5.4). A random effect model was used to pool the studies. A p value of less than 0.05 was considered significant and results were presented as Odds ratio with 95 % Confidence Intervals (CIs).

Result

The pooled analysis of our selected studies showed that Oteseconazole was associated with significantly reduced incidence of Recurrent Vulvovaginal Candidiasis (OR = 0.07; 95 % CI = 0.05-0.11; p < 0.00001, I2 = 0 %) through week 48. Additionally, Vivjoa has also been shown by our analysis to reduce incidence of RVVC through week 24. (OR = 0.05; 95 % CI = 0.03-0.09; p < 0.00001, I2 = 0 %) Furthermore, Oteseconazole was non-significantly associated with developing serious adverse effects during the treatment for Recurrent Vulvovaginal Candidiasis in comparison to the placebo (OR = 0.79; 95 % CI = 0.33-1.89; p = 0.60, I2 = 0 %).

Conclusion

The available evidence suggests Oteseconazole to be safer and more efficacious. However, limited patient population points towards the need of further large and dedicated trials for definitive conclusion.

Species identification, antifungal susceptibility patterns, and vitamin D3 level in women with vaginal candidiasis: a case-control study in Iran

Vulvovaginal candidiasis (VVC) is a fungal infection that is a global issue of women's health due to its association with morbidity, infertility, and economic costs. This study aimed to compare the vitamin D3 levels between women with VVC to healthy controls and determine the species distribution and susceptibility pattern of isolates. Species identification was performed using sequencing of the ITS-rDNA regions and amplification of the HWP1 gene. Antifungal susceptibility testing was determined by the disk diffusion method. Moreover, serum vitamin D3 levels were measured using a commercial ELISA (enzyme-linked immunosorbent assay) kit. Our results indicated that vitamin D3 level in women with VVC was lower than those of healthy women (p-value < .001). Candida albicans complex (62.8 percent) was the most common species, and most species were susceptible to fluconazole, itraconazole, ketoconazole, and nystatin. In conclusion, our study revealed a potential link between vitamin D3 deficiency and VVC in women. Although our findings showed significantly lower vitamin D3 levels in women with VVC, further research is needed to establish a definitive causative relationship between vitamin D3 deficiency and VVC. Nonetheless, our study highlights the potential importance of maintaining adequate levels of vitamin D3 and the need for further exploration in this area.

Biofilm Formation and Aspartyl Proteinase Activity and Their Association with Azole Resistance Among Candida albicans Causing Vulvovaginal Candidiasis, Egypt

Background

Candida albicans (C. albicans) is a major cause of vulvovaginal candidiasis (VVC), a condition that is commonly treated with azole agents. Biofilm formation and aspartyl proteinase production are important virulence factors that could be linked to azole resistance in C. albicans impeding therapy.

Aim

To find out the association of both factors with azole resistance among C. albicans isolated from VVC cases in Egyptian nonpregnant women of childbearing age.

Patients and Methods

In a cross-sectional study, C. albicans was isolated from nonpregnant females diagnosed clinically as having VVC during a 1-year study period. Susceptibility to azole agents was tested using the disc diffusion method. Biofilm formation and aspartyl proteinase production were assessed phenotypically. Additionally, two biofilm-related genes (ALS1 and HWP1) and three proteinase genes (SAP2, SAP4, and SAP6) were screened for using polymerase chain reaction (PCR).

Results

Among 204 C. albicans isolates, azole resistance ratios were as follows: voriconazole (30.4%), itraconazole (17.6%), fluconazole (11.3%) and econazole (6.4%). Biofilm-producing capacity was detected in 63.2% of isolates, and 63.2% were proteinase producers. The frequencies of ALS1 and HWP1 were 69.6% and 74.5%, respectively, while SAP2, SAP4, and SAP6 were 69.2%, 88.7%, and 64.7%, respectively. Biofilm formation was significantly associated with azole resistance (P < 0.001 for each tested azole agent) as was proteinase production (P < 0.001 for fluconazole, voriconazole, and econazole resistance and P = 0.047 for itraconazole).

Conclusion

Among nonpregnant Egyptian women of childbearing age, azole resistance in C. albicans causing VVC is significantly associated with biofilm formation and proteinase production. The development of new therapeutic agents that can target these factors is warranted.

Uncovering the Yeast Diversity in the Female Genital Tract: An Exploration of Spatial Distribution and Antifungal Resistance

Candida albicans is the leading cause of vulvovaginal yeast infections; however, other species are becoming relevant in this niche. The spatial distribution of these fungi in the female genital tract remains poorly understood. In this study, swab samples were collected from 33 patients, first from the anterior vulva and then from the upper third and right lateral wall of the vagina: 16 were with symptoms of vulvovaginal candidiasis and 17 were without characteristic symptoms; furthermore, the genus and species of each isolate were identified. In vitro susceptibility testing for fluconazole and clotrimazole was performed for all isolates. Candida albicans was the most common species (63.6%), followed by Rhodotorula spp. (51.5%), and then Candida parapsilosis (15.2%). Rhodotorula spp. and C. parapsilosis were more commonly associated with colonization, and C. albicans with infection. Rhodotorula spp. isolates presented a low susceptibility to fluconazole, with the MIC ranging from 32 to >64 µg/mL. Differences in susceptibility to fluconazole and clotrimazole between the pairs of vaginal and vulvar isolates were found for Candida albicans, Rhodotorula spp., and Nakaseomyces glabratus. The results suggest that different niches may impact the susceptibility profiles of the isolates, as well as their different clinical behaviors.

Candidiasis profile at the outpatient department of the university of cape coast hospital in the central region of Ghana: a retrospective study

INTRODUCTION

Vulvovaginal candidiasis (VVC) is a public health problem with an estimated 138 million women globally experiencing recurrent VVC annually. The microscopic diagnosis of VVC has low sensitivity, but it remains an essential tool for diagnosis as the microbiological culture methods are limited to advanced clinical microbiology laboratories in developing countries. The study retrospectively analyzed the presence of red blood cells (RBCs), epithelial cells (ECs), pus cells (PCs) and Candida albicans positive in wet mount preparation of urine or high vaginal swabs (HVS) samples to test for their sensitivity and specificity for the diagnosis of candidiasis.

METHODS

The study is a retrospective analysis at the Outpatient Department of the University of Cape Coast between 2013 and 2020. All urine and high vagina swabs (HVS) cultures samples using Sabourauds dextrose agar with wet mount data were analyzed. 2 × 2 contingency diagnostic test was used to ascertain the diagnostic accuracy of red blood cells (RBCs), epithelial cells (ECs), pus cells (PCs), and Candida albicans positive in wet mount preparation of urine or high vaginal swabs (HVS) samples for the diagnosis of candidiasis. The association of candidiasis among patients' demographics was analyzed using relative risk (RR) analysis.

RESULTS

The high prevalence of candida infection was among female subjects 97.1% (831/856) compared to males 2.9% (25/856). The microscopic profiles which characterized candida infection were pus cells 96.4% (825/856), epithelial cells 98.7% (845/856), red blood cells (RBCs) 7.6% (65/856) and Candida albicans positive 63.2% (541/856). There was a lower risk of Candida infections among male patients compared to female patients RR (95% CI) = 0.061 (0.041-0.088). The sensitivity (95%) for detecting Candida albicans positive and red blood cells (0.62 (0.59-0.65)), Candida albicans positive and pus cells (0.75 (0.72-0.78)) and Candida albicans positive and epithelial cells (0.95 (0.92-0.96)) with corresponding specificity (95% CI) of 0.63 (0.60-0.67), 0.69 (0.66-0.72) and 0.74 (0.71-0.76) were detected among the high vaginal swab samples.

CONCLUSION

In conclusion, the study has shown that the presence of PCs, ECs, RBCs or ratio of RBCs/ECs and RBCs/PCs in the wet mount preparation from urine or HVS can enhance microscopic diagnosis of VVC cases.

New Antifungals for Vulvovaginal Candidiasis: What Is Their Role?

New antifungals, ibrexafungerp and oteseconazole, are now available for treatment of vulvovaginal candidiasis. Both have novel antimicrobial and pharmacokinetic properties and advantages over fluconazole, although comparative trials have involved only placebo. In the absence of allergy, intolerance, and resistance, it is unclear whether these antifungals will replace fluconazole.

Oral Ibrexafungerp for Vulvovaginal Candidiasis Treatment: An Analysis of VANISH 303 and VANISH 306

Background: Ibrexafungerp is a novel antifungal treatment for acute vulvovaginal candidiasis (VVC). Using pooled data from two phase three studies (VANISH 303 and 306) in the treatment of acute VVC, this analysis sought to determine the effectiveness of ibrexafungerp in various patient subgroups that may impact outcomes. Materials and Methods: Data from VANISH 303 (NCT03734991) and VANISH 306 (NCT03987620) evaluating ibrexafungerp 300 mg twice daily (BID) for 1 day versus placebo, were pooled and analyzed to determine clinical cure rate, clinical improvement, and mycological cure at the test-of-cure visit (day 11 ± 3) and symptom resolution at the follow-up visit (day 25 ± 4) in the overall population. Patient subgroups analyzed included race, body mass index (BMI), baseline vulvovaginal signs and symptoms (VSS) score, and Candida species. Results: At the test-of-cure visit, patients receiving ibrexafungerp, compared with those who received placebo, had significantly higher rates of clinical cure (56.9% [214/376 patients] vs. 35.7% [65/182 patients]), clinical improvement (68.4% [257/376 patients] vs. 45.1% [82/182 patients]), and mycological cure (54.0% [203/376 patients] vs. 24.2% [44/182 patients]; all p < 0.0001). At the follow-up visit, patients receiving ibrexafungerp had sustained responses with higher symptom resolution rates (66.8% [251/376 patients]) versus placebo (48.4% [88/182 patients]; p < 0.0001). Race, BMI, baseline VSS score (including VSS severity score 13-18), and Candida species infection did not adversely affect clinical cure rates. Safety analysis results were consistent with the individual studies. Conclusions: Ibrexafungerp provides a safe and well-tolerated first-in-class fungicidal, 1-day oral treatment for patients with acute VVC, the first new therapy in >20 years. Clinical Trial Registration Number: NCT03734991.

Experience With a Non-Hormonal Centella Asiatica, Hyaluronic Acid and Prebiotic-Based Vaginal Gel in Women With Recurrent Vulvovaginal Candidiasis: Case Studies

Recurrent vulvovaginal candidiasis (RVVC) affects millions of women worldwide, severely impairing their quality of life. Despite the existence of multiple induction and maintenance therapeutic strategies, mainly based on antifungals, relapse rates are still high. Palomacare^® is a vaginal gel containing, among others, hyaluronic acid and Centella asiatica, with repairing and moisturizing properties. A series of 5 clinical cases showed that symptoms improved and even disappeared in women with RVVC receiving Palomacare^®. None of the patients experienced recurrence after the treatment, having their vaginal health restored, suggesting that the non-hormonal Centella asiatica, hyaluronic acid and prebiotic-based gel is effective for preventing RVVC relapse in women of reproductive age.

In Vitro Antifungal Activity of Azoles and Other Antifungal Agents Against Pathogenic Yeasts from Vulvovaginal Candidiasis in China

BACKGROUND

Vulvovaginal candidiasis (VVC) is a public health issue worldwide. Little is known of the optimal treatment of recurrent VVC (RVVC) has not been established.

OBJECTIVE

Through the in vitro antifungal susceptibility profiling of VVC isolates, we hope to foster significant improvements in the control and treatment of this disease.

METHODS

Candida isolates from VVC patients were collected from 12 hospitals in 10 cities across China. Species were identified by phenotype analysis and DNA sequencing. Species were identified by phenotype analysis and DNA sequencing. Susceptibilities to 11 drugs were determined by Clinical and Laboratory Standards Institute broth microdilution.

RESULTS

543 strains were isolated from those VVC patients enrolled in this study, of which, 15.7% were from RVVC. The most commonly identified species was C. albicans (460, 84.71%), and the most commonly non-albicans Candida spp. (NAC) was C. glabrata (47, 8.66%). NAC also included C. Krusei, Meyerozyma Guillermondii, Meyerozyma Caribbica, C. Tropicalis, C. Parapsilosis, and C. Nivariensis. Most C. albicans isolates were susceptible to caspofungin (99.8%), followed by fluconazole (92%) and voriconazole (82.6%). The proportion of C. albicans strains with wild type (WT) MICs that were susceptible to amphotericin B and caspofungin were 98%, followed by posaconazole at 95%, itraconazole at 86%, fluconazole at 74% and voriconazole at 54%. The fluconazole MICs for C. albicans were lower than those for NAC (P < 0.05), while the itraconazole MICs showing no significant difference (P > 0.05). The susceptible rate of uncomplicated VVC to fluconazole was 92%. The proportion of WT strains to fluconazole in RVVC was much lower than that in other types of VVC (67 vs. 77%, P < 0.05). However, the proportions of WT strains to itraconazole in RVVC was over 85%, which was much higher than that to fluconazole (87 vs. 67%, P < 0.05).

CONCLUSIONS

C. albicans was still the predominant pathogen for VVC in China, while C. glabrata was the main species in NAC. Fluconazole could still be used as an empirical treatment for uncomplicated VVC. However, fluconazole may not be the first choice for the therapy of RVVC. In such cases, itraconazole appears to be the more appropriate treatment. As for VVC caused by NAC, nonfluconazole drugs, such as itraconazole, may be a good choice.

Clinical challenges in diagnosis and treatment of recurrent vulvovaginal candidiasis

Vulvovaginal candidiasis is a common infection associated most often with the overgrowth of the fungal species Candida albicans. Although most women will have at least one episode of vulvovaginal candidiasis in their lifetime, some will experience recurrent infections. Recurrent vulvovaginal candidiasis can significantly impact quality of life, causing both physical and psychological symptoms, and poses a substantial financial burden for women and the health care system. Acute vulvovaginal candidiasis infections are often diagnosed symptomatically by clinicians or self-diagnosed by patients themselves; this can result in over- and underdiagnosis, as well as misdiagnosis, and has the potential to lead to ineffective treatment and incomplete infection resolution. Clinical diagnosis should include confirmatory laboratory tests, including microscopy and fungal culture, especially in women with a history of recurrent vulvovaginal candidiasis, who are more likely than women with vulvovaginal candidiasis to be infected with less-common Candida species or with azole-resistant strains. With proper diagnosis, most acute vulvovaginal candidiasis episodes can be successfully treated; however, women with recurrent vulvovaginal candidiasis may require long-term maintenance therapy. US-based guidelines recommend ⩽6 months of maintenance fluconazole treatment, but infection recurs in up to 50% of women treated. There are currently no US Food and Drug Administration–approved treatments for recurrent vulvovaginal candidiasis; however, several promising treatments for recurrent vulvovaginal candidiasis are in development.

Bioactive compounds with antifungal activity against pathogens isolated from pregnant woman: Gallesia integrifolia (garlic wood) is a promising treatment for vulvovaginal candidiasis

ETHNOPHARMACOLOGICAL RELEVANCE

The leaves, bark, and roots of Gallesia integrifolia are consumed in folk medicine through infusion, decoction, and topical preparation by crushing because of its pharmacological properties in several peripheral system disorders, including microbial infections. The presence of various molecules in different parts of the plant likely confers this species' fungicidal action, but scientific evidence is lacking. Vulvovaginal candidiasis mainly affects women of reproductive age. When left untreated, it can cause pregnancy complications. Currently available antifungals often cause undesirable side effects. New alternative therapeutic strategies based on medicinal plants have been proposed.

AIM

To investigate the antifungal activity of G. integrifolia against vulvovaginal candidiasis secretion in pregnant women.

MATERIALS AND METHODS

Antifungal activity was determined by the minimum inhibitory concentration (MIC), determined by broth microdilution method using Candida spp (NEWP1210), C. albicans (CCCD-CC001), C. tropicalis (CCCD-CC002) standard and clinical isolates from pregnant women with vulvovaginal candidiasis. Nystatin and fluconazole were used as positive controls. The chemical composition of essential oils that were extracted from leaves, flowers, and fruits of G. integrifolia was determined by gas chromatography coupled to mass spectrometry. Reverse docking was used to suggest a possible target in Candida. Conventional docking was used to identify the most probable compound that inhibits fungal growth.

RESULTS

A total of 24 compounds were identified, accounting for ∼99% of volatile constituents in the essential oils. Leaves of G. integrifolia contained 3,5-dithiahexanol-5,5-dioxide (40.93%), flowers contained methionine ethyl ester (46.78%), and fruits contained 2,8-dithianonane (54.01%) as the most abundant compounds. The MICs of essential oils of leaves, flowers, and fruits of G. integrifolia against standard strains of Candida spp, C. albicans, and C. tropicalis ranged from 13.01 to 625.00 μg/mL. The essential oil of flowers more effectively inhibited Candida spp. Essential oils of leaves and flowers were similar to fluconazole against C. albicans. Essential oils of flowers and fruits were similar to fluconazole against C. tropocalis. In Candida yeast species that were isolated from vaginal secretion samples from pregnant patients, the MICs of leaves and flowers ranged from 52.08 to 5000.00 μg/mL. The essential oil of leaves (277.77 μg/mL) was the most active against C. albicans. No significant differences were found between the essential oils of leaves and flowers against C. glabrata. Docking simulations suggested that phytol in leaves and flowers was responsible for the antimicrobial effect.

CONCLUSION

The present results suggest the potential therapeutic use of G. integrifolia, especially its leaves and flowers, against Candida and vulvovaginal candidiasis.

Management of recurrent vulvovaginal candidosis: Narrative review of the literature and European expert panel opinion

Recurrent vulvovaginal candidosis (RVVC) is a chronic, difficult to treat vaginal infection, caused by Candida species, which affects women of all ages and ethnic and social background. A long-term prophylactic maintenance regimen with antifungals is often necessary. In most clinical practice guidelines, oral fluconazole is recommended as the first-line treatment. Although clinical resistance to antifungal agents remains rare, overexposure to azoles may increase the development of fluconazole-resistant C. albicans strains. In addition, non-albicans Candida species are frequently dose-dependent susceptible or resistant to fluconazole and other azoles, and their prevalence is rising. Available therapeutic options to treat such fluconazole-resistant C. albicans and low susceptibility non-albicans strains are limited. Ten experts from different European countries discussed problematic issues of current RVVC diagnosis and treatment in two audiotaped online sessions and two electronic follow-up rounds. A total of 340 statements were transcribed, summarized, and compared with published evidence. The profile of patients with RVVC, their care pathways, current therapeutic needs, and potential value of novel drugs were addressed. Correct diagnosis, right treatment choice, and patient education to obtain adherence to therapy regimens are crucial for successful RVVC treatment. As therapeutic options are limited, innovative strategies are required. Well- tolerated and effective new drugs with an optimized mechanism of action are desirable and are discussed. Research into the impact of RVVC and treatments on health-related quality of life and sex life is also needed.

Prevalence and Antifungal Susceptibility of Clinically Relevant Candida Species, Identification of Candida auris and Kodamaea ohmeri in Bangladesh

Candida species are major fungal pathogens in humans. The aim of this study was to determine the prevalence of individual Candida species and their susceptibility to antifungal drugs among clinical isolates in a tertiary care hospital in Bangladesh. During a 10-month period in 2021, high vaginal swabs (HVSs), blood, and aural swabs were collected from 360 patients. From these specimens, Candida spp. was isolated from cultures on Sabouraud dextrose agar media, and phenotypic and genetic analyses were performed. A total of 109 isolates were recovered, and C. albicans accounted for 37%, being derived mostly from HVSs. Among non-albicans Candida (NAC), C. parapsilosis was the most frequent, followed by C. ciferrii, C. tropicalis, and C. glabrata. Three isolates from blood and two isolates from aural discharge were genetically identified as C. auris and Kodamaea ohmeri, respectively. NAC isolates were more resistant to fluconazole (overall rate, 29%) than C. albicans (10%). Candida isolates from blood showed 95% susceptibility to voriconazole and less susceptibility to fluconazole (67%). Two or three amino acid substitutions were detected in the ERG11 of two fluconazole-resistant C. albicans isolates. The present study is the first to reveal the prevalence of Candida species and their antifungal susceptibility in Bangladesh.

Importance of Candida infection and fluconazole resistance in women with vaginal discharge syndrome in Namibia

Background

Vaginal discharge syndrome (VDS) is a common condition. Clinical management targets sexually transmitted infections (STIs) and bacterial vaginosis (BV); there is limited focus on Candida infection as cause of VDS. Lack of Candida treatment coverage and, if present, antifungal resistance may result in VDS treatment failure. This study aimed to determine the prevalence of Candida infection, antifungal resistance, and coinfections in Namibian women with VDS.

Methods

A cross-sectional study was performed using 253 vaginal swabs from women with VDS in Namibia. Demographic data was collected, and phenotypic and molecular detection of Candida species was performed followed by fluconazole susceptibility testing of Candida isolates. BV was diagnosed using Nugent score microscopy; molecular detection of Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis was performed.

Results

Candida species was detected in 110/253 women (43%). Ninety women (36%) had Candida albicans and 24 (9.5%) had non-albicans Candida species. The non-albicans species detected were 19 (17%) Candida glabrata, 4.0 (3.5%) Candida krusei, and 1.0 (0.9%) Candida parapsilosis. Candida albicans were more frequently isolated in younger (p = 0.004) and pregnant women (p = 0.04) compared to non-albicans Candida species. Almost all (98%) Candida albicans isolates were susceptible to fluconazole while all non-albicans Candida species were fluconazole resistant. STIs were diagnosed in 92 women (36%): 30 (12%) with C. trachomatis, 11 (4.3%) N. gonorrhoeae, and 70 (28%) T. vaginalis; 98 (39%) women had BV. Candida infection alone was diagnosed in 30 women (12%), combined with STIs in 42 women (17%) and was concurrent with BV in 38 women (15%). Candida infection was more often detected in swabs from women without C. trachomatis detected (6.4% vs. 16%; OR 0.30; 95% CI 0.10–0.77, p = 0.006).

Conclusions

The high prevalence of Candida infection, especially those due to non-albicans Candida species that are resistant to fluconazole, is a great concern in our setting and may lead to poor treatment outcomes. Access to microbiological testing for Candida species in the context of syndromic management is warranted.

Recurrent vulvovaginal candidiasis with Candida glabrata – a management conundrum

High rates of azole-resistance and limited availability of pharmacological agents within the UK can make recurrent vulvovaginal candidiasis (RVVC) with Candida glabrata a challenging infection to treat. In this report, we describe our experience in managing C. glabrata RVVC and present the case of a patient with poor response to therapy and a protracted treatment course, spanning almost 4 years. We also highlight the need for evidence-based management protocols that consider the national availability of alternative treatments.

First detection of mutated ERG11 gene in vulvovaginal Candida albicans isolates at Ouagadougou/Burkina Faso

Background

Vulvovaginal candidiasis is an important cause of morbidity among women due to Candida species. In the last decades, resistance to azoles, first-line antifungals has increased. One molecular mechanism of azole resistance by Candida involves mutations in the ERG11 gene encoding lanosterol 14-α-demethylase, the target enzyme. This study was conducted to identify the clinical Candida species associated in vulvovaginal candidiasis; to determine the rate of antifungal resistance among Candida albicans isolates and to determine mutated ERG11 gene at Saint Camille Hospital in Ouagadougou, Burkina Faso.

Methods

Antifungals susceptibility were performed using Kirby–Bauer disk diffusion method. ERG11 gene was detected using conventional PCR in C. albicans isolates resistant to at least one azole.

Results

Out of 262 clinical strains isolated, C. albicans accounted for 59.90%, followed by Candida glabrata 27.86%, Candida famata 7.25%, Candida tropicalis 3.05% and Saccharomyces cerevisiae 1.91%. Resistance rate of fluconazole to C. albicans was 59.54%. ERG11 gene was found in 9.79% of 92 C. albicans strains resistant to azoles.

Conclusions

This detection of mutated ERG11 gene in C. albicans is the first in Burkina Faso and may be a cause of azole resistance in recurrent Candida vulvovaginitis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07619-5.

Loop-mediated isothermal amplification for Candida species surveillance in under-resourced setting: a review of evidence

INTRODUCTION

Non-albicans Candida species (NACS) have emerged as a major public health burden although they are still underappreciated. Some NACS have intrinsic antifungal resistance, requiring constant surveillance to improve patient care and thwart outbreaks of recalcitrant candida infections. However, effective Candida species surveillance has relied on PCR-based or other high-end techniques that are largely unaffordable in under-resourced countries. Loop-mediated isothermal amplification (LAMP) has emerged as a potentially effective and affordable technique for infectious disease surveillance, especially in under resourced settings.

AREAS COVERED

We critically reviewed current literature on application of LAMP for Candida species identification in pure fungal isolates, and in clinical and non-clinical samples.

EXPERT OPINION

LAMP has been studied for Candida species identification, including the NACS. Besides a short turnaround time, LAMP has analytical sensitivity and specificity that are not only higher than culture method but also comparable with conventional and quantitative PCR techniques. However, extensive evaluation of LAMP for Candida species detection using various types of clinical and environmental samples are required before deploying the technique for Candida species surveillance.

Prevalence, Antifungal Susceptibility and Etiology of Vulvovaginal Candidiasis in Sub-Saharan Africa: A Systematic Review with Meta-analysis and Meta-regression

Vulvovaginal candidiasis (VVC) is a commonly occurring form of mucocutaneous candidiasis in women. The aim of this study was to comprehensively investigate the prevalence, antifungal susceptibility, and etiology of VVC in sub-Saharan Africa (SSA). A search of studies was conducted in seven online databases and the reference lists of selected studies. Observational studies published between January 2000, to July 2021, that met the eligibility criteria were included. Meta-analyses with random and fixed-effects model, and subgroup analyses were performed using STATA 16.0. A total of 41 studies including 15 723 participants were included in the meta-analyses. The pooled prevalence of VVC was 33% (95% Confidence Interval (CI): 28 - 38%, I2 = 98%, p < 0.001). Pregnant women had 6% higher odds of having VVC compared to non-pregnant women (Odds Ratio (OR): 1.06, 95% CI: 0.99 - 1.13, p = 0.107). The odds of diagnosing VVC were 40% higher in symptomatic patients than general study population (OR: 1.4, 95% CI: 1.3 - 1.5, p < 0.0001). In 17 studies, a total of 2112 isolates of Candida species were reported: 1514 (71.7%) C. albicans, 510 (24.1%) non-albicans Candida (NAC) species and 88 (4.2%) unidentified Candida spp. Of the NAC species detected, C. glabrata (40.9%, n = 209), C. krusei (21.2%, n = 108) and C. tropicalis (22.7%, n = 116) were the most common. Resistance to fluconazole in C. albicans using disc diffusion methods ranged from 6.8% in Cameroon to 53.7% in Ethiopia. One-third of women in SSA have VVC, mainly caused by C. albicans. Data on the susceptibility of the Candida isolates to commonly used antifungal agents is limited and warrants further research.

Divergent EGFR/MAPK-Mediated Immune Responses to Clinical Candida Pathogens in Vulvovaginal Candidiasis

Vulvovaginal candidiasis (VVC) is characterized by symptomatic inflammatory responses in the vagina caused by Candida albicans and non-albicans Candida (NAC) species. The epidermal growth factor receptor (EGFR) -mitogen-activated protein kinase (MAPK) signaling pathway has been linked to immune responses of oral mucosa after C. albicans exposure, but whether this pathway plays a similar response in vaginal epithelial cells is not known. Here, we observed that phosphorylation of EGFR and p38 was continuously activated in vaginal epithelial cells by C. albicans strain SC5314. This differs markedly from oral epithelial cells, which respond in a biphasic manner in order to properly discriminate the morphology of C. albicans. When compared with SC5314, a highly azole-resistant C. albicans isolate 1052 can induce a stronger phosphorylated signal of EGFR and p38, while clinically-isolated NAC strains including C. tropicalis, C. glabrata, C. parapsilosis and C. auris trigger higher levels of phosphorylated ERK1/2 and c-Fos than C. albicans. Inhibition of EGFR significantly reduces inflammatory response and epithelial damage induced by C. albicans both in vitro and in vivo, while inhibition of p38 leads to significant repair of epithelial damage triggered by both C. albicans and NAC species. These results confirm the importance of the EGFR-MAPK signaling in VVC pathogenesis and highlight the remarkable immunogenic differences between C. albicans and NAC species in host-microbe interactions.

Multilocus Sequence Typing and Antifungal Susceptibility of Vaginal and Non-vaginal Candida glabrata Isolates From China

Candida glabrata is a common cause of Candida infections. In our present study, we investigated the antifungal susceptibility and molecular epidemiology of vaginal and non-vaginal C. glabrata isolates. Seventy-six vaginal C. glabrata strains isolated from patients with vulvovaginal candidiasis and 57 non-vaginal C. glabrata isolates were collected at two hospitals in Shanghai, China. Antifungal susceptibility was examined using a broth microdilution method. Multilocus sequence typing was used for genotyping. Overall, 28 (21.1%), 28 (21.1%), and 29 (21.8%) C. glabrata isolates were resistant to fluconazole, itraconazole, and voriconazole, respectively. Briefly, 18 (23.7%), 18 (23.7%), and 19 (25%) vaginal strains were resistant to fluconazole, itraconazole, and voriconazole. While the resistance to these antifungals were all 17.5% (10/57) in non-vaginal strains. All isolates retained susceptibility to amphotericin B, and only four non-vaginal isolates were caspofungin resistant. Genotyping identified 17 ST patterns. In non-vaginal samples, the same genotypes appear as in the vaginal samples, except for one genotype (ST-182), while in the vaginal samples more genotypes appear (ST8, ST19, ST45, ST55, ST66, ST80, ST138, and ST17). The most common genotype was ST7 (81 strains), followed by ST10 (14 strains) and ST15 (11 strains). The majority of resistant phenotype strains (25/30, 83.3%) correlated to the predominant genotype (ST7), and the rest belonged to ST3 (2/30, 6.7%), ST10 (1/30, 3.3%), ST19 (1/30, 3.3%), and ST45 (1/30, 3.3%). Our survey revealed cross-resistance in vaginal and non-vaginal C. glabrata isolates. Moreover, there is no genotype associated with the resistance phenotype.

Exploring the Antifungal Activity and Action of Saussurea costus Root Extracts against Candida albicans and Non-albicans Species

The isolation and assessment of the active constituents in polar and non-polar crude extracts of Saussurea costus roots as antifungal agents, against Candida albicans and non-C. albicans (NAC) species, was the aim of this current investigation. The SEM “Scanning electron microscopy” imaging provided potential action modes of n-hexane extract (nhhE) toward Candida spp., whereas the TLC-DB “Thin layer chromatography-direct bioautography” was employed for detecting the anticandidal compounds. nhhE had the greatest biocidal activity against all strains and clinical isolates of Candida spp. with maximum zones of inhibition. SEM revealed the occurrence of irregular, dense inclusions of C. albicans cell walls after treatment with nhhE for 12 h. Complete morphological distortions with lysed membranes and deterioration signs appeared in most treated cells of C. parapsilosis. The most effectual compound with anticandidal activity was isolated using TLC-BD and identified as sesquiterpene by GC/MS analysis. The infra-red analysis revealed the presence of lactone ring stretching vibrations at 1766.72 cm−1. The anticandidal activity of nhhE of S. costus roots was confirmed from the results, and the treated cotton fabrics with nhhE of S. costus possessed observable activity against C. albicans. Data could recommend the practical usage of S. costus extracts, particularly nhhE, as influential natural bioactive sources for combating pathogenic Candida spp.

A prospective study on vulvovaginal candidiasis: multicentre molecular epidemiology of pathogenic yeasts in China

BACKGROUND

Vulvovaginal candidiasis (VVC) is frequent in women of reproductive age, but very limited data are available on the epidemiology in cases of VVC in China.

OBJECTIVES

The current study has been conducted to reveal the prevalence, species distribution of yeast causing VVC and molecular genetics of Candida albicans in China.

METHODS

Vaginal swabs were collected from 543 VVC outpatients recruited in 12 hospitals in China between September 2017 and March 2018. They were preliminarily incubated on Sabouraud dextrose agar and then positive subjects of which were then transmitted to our institute for further identification. CHROMagar™ was used to isolate Candida species, and all isolates were finally identified by DNA sequencing. Multilocus sequence typing (MLST) was used to analyse phylogenetic relationships of the various C. albicans isolates.

RESULTS

Eleven different yeast species were identified in 543 isolates, among which C. albicans (84.7%) was the most frequent, followed by C. glabrata (8.7%). We obtained 117 unique diploid sequence types from 451 clinical C. albicans isolates and 92 isolates (20.4%) belonged to a New Clade. All the strains appearing in the New Clade were from northern China and they were isolated from non-recurrent VVC.

CONCLUSIONS

Our findings suggest that C. albicans are still the main cause of VVC in China and the majority of C. albicans isolates belongs to Clade 1 with DST 79 and DST 45 being two most common. Moreover, the New Clade revealed in our study seems to be specific to northern China.

Antifungal susceptibility profile of invasive Candida glabrata isolates (2009-2020) from a tertiary care hospital laboratory in Pakistan

Introduction. Invasive infections with Candida glabrata are a global concern due to poor clinical outcomes and propensity to acquire resistance to antifungal agents. Hypothesis/Gap Statement. Monitoring emerging resistance and trends in Candida glabrata, an important agent of candidemia in Pakistan, is critical for patient management; data that is missing from Pakistan. Aim. Thus, this study evaluated antifungal resistance and MICs) distribution in invasive C. glabrata isolates from Pakistan. Methods. This cross-sectional and retrospective study was conducted from January 2009 to March 2020 at a clinical laboratory in Pakistan that has a nation-wide network. Antifungal susceptibility data of 277 candidemia, deep organ and soft tissue (invasive) C. glabrata sensu lato isolates against fluconazole, itraconazole, voriconazole, posaconazole, anidulafungin, micafungin, caspofungin and amphotericin B was retrieved. Susceptibility testing was performed using colorimetric broth microdilution and interpreted using CLSI criteria. Demographics, clinical history and outcome were studied. Chi-square test was used to demonstrate association between antifungal resistance and clinical characteristics of the patients. Results. We identified 277 patients with invasive C. glabrata infection. Of which 48 (18.4%) isolates were resistant to fluconazole (MIC ≥64 mg l^-1), one isolate each was resistant to amphotericin (MIC=2 mg l^-1), anidulafungin (MIC=1 mg l^-1) and micafungin (MIC=0.5 mg l^-1). MIC₉₀ for fluconazole was 64 mg l^-1 and other triazoles 2 mg l^-1, caspofungin 0.12 mg l^-1, anidulafungin 0.06 mg l^-1, micafungin 0.03 mg l^-1 and amphotericin 0.5 mg l^-1. Fluconazole MIC ≥64 mg l^-1, caspofungin MIC >0.06 mg l^-1 and amphotericin MIC >0.25 mg l^-1 (above MIC₅₀) were significantly associated with patient being alive at the time of reporting, no use of healthcare devices, nor infection with other fungi. Fluconazole resistance was significantly associated with prior antifungal use by the patient. Conclusion. Surveillance data of antifungal resistance among common Candida species should be monitored closely for identification of resistant strains.

Human albumin enhances the pathogenic potential of Candida glabrata on vaginal epithelial cells

The opportunistic pathogen Candida glabrata is the second most frequent causative agent of vulvovaginal candidiasis (VVC), a disease that affects 70–75% of women at least once during their life. However, C. glabrata is almost avirulent in mice and normally incapable of inflicting damage to vaginal epithelial cells in vitro. We thus proposed that host factors present in vivo may influence C. glabrata pathogenicity. We, therefore, analyzed the impact of albumin, one of the most abundant proteins of the vaginal fluid. The presence of human, but not murine, albumin dramatically increased the potential of C. glabrata to damage vaginal epithelial cells. This effect depended on macropinocytosis-mediated epithelial uptake of albumin and subsequent proteolytic processing. The enhanced pathogenicity of C. glabrata can be explained by a combination of beneficial effects for the fungus, which includes an increased access to iron, accelerated growth, and increased adhesion. Screening of C. glabrata deletion mutants revealed that Hap5, a key regulator of iron homeostasis, is essential for the albumin-augmented damage potential. The albumin-augmented pathogenicity was reversed by the addition of iron chelators and a similar increase in pathogenicity was shown by increasing the iron availability, confirming a key role of iron. Accelerated growth not only led to higher cell numbers, but also to increased fungal metabolic activity and oxidative stress resistance. Finally, the albumin-driven enhanced damage potential was associated with the expression of distinct C. glabrata virulence genes. Transcriptional responses of the epithelial cells suggested an unfolded protein response (UPR) and ER-stress responses combined with glucose starvation induced by fast growing C. glabrata cells as potential mechanisms by which cytotoxicity is mediated.Collectively, we demonstrate that albumin augments the pathogenic potential of C. glabrata during interaction with vaginal epithelial cells. This suggests a role for albumin as a key player in the pathogenesis of VVC.

Candida glabrata is the overall second causative species of candidiasis in humans, but little is known about the pathogenicity mechanisms of this yeast. C. glabrata is capable of causing lethal systemic candidiasis mostly in elderly immunocompromised patients, but is also a frequent cause of vulvovaginal candidiasis. These clinical insights suggest that C. glabrata has a high virulence potential, yet little pathogenicity is observed in both in vitro and in vivo infection models. The finding that human albumin, the most abundant protein in the human body, is boosting C. glabrata pathogenicity in vitro provides novel insights into C. glabrata pathogenicity mechanisms and shows that the presence of distinct human factors can have a significant influence on the virulence potential of a pathogenic microbe.

Phase 2 randomized study of oral ibrexafungerp vs fluconazole in vulvovaginal candidiasis

Background

Vulvovaginal candidiasis affects approximately 75% of women in their lifetime. Approved treatment options are limited to oral or topical azoles. Ibrexafungerp, a novel, first-in-class oral triterpenoid glucan synthase inhibitor, has demonstrated broad fungicidal Candida activity and a favorable tolerability profile. The primary objective of this dose-finding study was to identify the optimal dose of oral ibrexafungerp in patients with acute vulvovaginal candidiasis.

Methods

Patients with vulvovaginal signs and symptoms score ≥7 were randomized equally to 6 treatments groups: 5 treatment doses of oral ibrexafungerp or oral fluconazole 150 mg. The primary endpoint was the percentage of patients with a clinical cure (complete resolution of vulvovaginal signs and symptoms) at the test-of-cure visit (day 10).

Results

Overall, 186 patients were randomized into the 6 treatment groups. Results, using the modified intent-to-treat population (baseline positive culture), are reported for ibrexafungerp 300 mg twice daily (BID) for 1 day (n = 27), which was the dose selected for phase 3 studies, and fluconazole 150 mg for 1 day (n = 24). At day 10, the clinical cure rates for ibrexafungerp and fluconazole were 51.9% and 58.3%, respectively; at day 25, patients with no signs or symptoms were 70.4% and 50.0%, respectively. During the study ibrexafungerp patients required less antifungal rescue medications compared with fluconazole (3.7% vs 29.2%, respectively). Ibrexafungerp was well tolerated, with the most common treatment-related adverse events being mild gastrointestinal events.

Conclusions

Ibrexafungerp is a well-tolerated novel antifungal with comparable efficacy to fluconazole in the treatment of acute vulvovaginal candidiasis.

Clinical Trials Registration

NCT03253094

Inhibitory effects of Lactobacillus casei Shirota against both Candida auris and Candida spp. isolates that cause vulvovaginal candidiasis and are resistant to antifungals

BACKGROUND

Vulvovaginal candidiasis (VVC), the second leading cause of genital infection in women of reproductive age, is caused by yeasts of the genus Candida. Treatment is usually empirical and performed with azoles, which have shown increasing ineffectiveness due to resistance from these species. This therapeutic challenge has led to the search for new treatment strategies. Lactobacillus spp. produce several components with microbicidal effects, such as lactic acid. These species are the main components of a healthy vaginal microbiota and have been used as probiotics. The aim of this work was to investigate the in vitro inhibitory effects of Lactobacillus casei Shirota on both the Candida spp. that cause VVC and on C. auris.

METHODS

The microbicidal effects of L. casei Shirota on the main VVC-causing species, C. albicans, C. tropicalis, C. norvegensis and C. parapsilosis, in addition to C. auris were investigated by counting the Colony-forming Units (CFUs) after cocultivation. The antifungal activity of lactic acid against these Candida strains was assessed using the microtiter broth dilution method to determine the minimum inhibitory concentrations (MICs). The effects of L. casei Shirota on hyphal and early biofilm formation was measured by optical microscopy.

RESULTS

L. casei Shirota showed inhibitory action against all tested Candida spp., ranging from 66.9 to 95.6% inhibition depending on the species. This inhibition is possibly related to the production of lactic acid, since lactic acid has shown microbicidal action against these same Candida spp. at a concentration of 5 mg/mL, which corresponds to half of the normal physiological concentration. In addition, L. casei Shirota was able to reduce the formation of C. albicans hyphae and early biofilms, showing strong anti-Candida effects.

CONCLUSIONS

These results suggest that L. casei Shirota has antifungal activity against the Candida species that cause VVC. L. casei also has microbicidal action against C. auris.

Susceptibility to Clotrimazole of Candida spp. Isolated from the Genitourinary System-A Single Center Study

The aim of this study was to determine the susceptibility to clotrimazole of 125 isolates of Candida spp. originated from the genitourinary system of hospitalized patients as well as outpatients, tested in the mycological laboratory of Wroclaw Medical University in the years 1999–2018. The minimal inhibitory concentrations of clotrimazole and fluconazole were determined with the use of the microdilution method according to EUCAST, and the MFC was determined by subsequent subculture on Sabouraud agar. For the tested population of Candida yeasts, the MIC values of clotrimazole ranged from 0.008 to 8 mg/L, and MIC90 was 1 mg/L, whereas MIC50 was 0.008 mg/L. The minimal fungicidal concentration ranged between 1 and >8 mg/L. The great majority of the isolates (88%; 110/125) displayed MIC < 1 mg/L and were classified as WT (wild-type), whereas MIC ≥ 1 mg/L was determined for 2/61 (3.2%) isolates of C. albicans, 9/38 (23.6%) of C. glabrata, 1/2 of C. tropicalis, and 3/3 of C. guilliermondii. Six isolates (four of C. glabrata and two of C. albicans), defined as non-WT for clotrimazole, were classified as resistant to fluconazole, according to CBP from EUCAST. The isolates with elevated MIC to clotrimazole originated mostly from patients of the pediatric hematology unit, and their proportion in this population amounted to 17.8% (13 out of 73 isolates). In contrast, among strains from ambulatory patients, the highest observed MIC value was 1 mg/L (1 out of 37 isolates; 2.7%). The data obtained correlate well with those of most published studies on the in vitro susceptibility of Candida spp. to clotrimazole, which is usually very high. However, the existence of reports regarding the growing prevalence of resistant isolates has also to be noted. These results support the need for routinely checking the susceptibility of Candida clinical isolates to this imidazole derivative.

Ibrexafungerp versus placebo for vulvovaginal candidiasis treatment: a phase 3, randomized, controlled superiority trial (VANISH 303)

Background

Current treatment of vulvovaginal candidiasis (VVC) is largely limited to azole therapy. Ibrexafungerp is a first-in-class triterpenoid antifungal with broad-spectrum anti-Candida fungicidal activity. The objective of this study was to evaluate the efficacy and safety of ibrexafungerp compared with placebo in patients with acute VVC.

Methods

Patients were randomly assigned 2:1 to receive ibrexafungerp (300 mg twice for 1 day) or placebo. The primary endpoint was the percentage of patients with a clinical cure (complete resolution of vulvovaginal signs and symptoms [VSS] = 0) at test-of-cure (day 11 ± 3). Secondary endpoints included the percentage of patients with mycological eradication, overall success (clinical cure and mycological eradication), clinical improvement (VSS ≤ 1) at test-of-cure, and symptom resolution at follow-up (day 25 ± 4).

Results

Patients receiving ibrexafungerp had significantly higher rates of clinical cure (50.5% [95/188] vs 28.6% [28/98]; P = .001), mycological eradication (49.5% [93/188] vs 19.4% [19/98]; P < .001), and overall success (36.0% [64/178] vs 12.6% [12/95]; P < .001) compared with placebo. Symptom resolution was sustained and further increased with ibrexafungerp compared with placebo (59.6% [112/188] vs 44.9% [44/98]; P = .009) at follow-up. Post hoc analysis showed similar rates of clinical cure and clinical improvement at test-of-cure for Black patients (54.8% [40/73] and 63.4% [47/73], respectively) and patients with a body mass index >35 (54.5% [24/44] and 68.2% [30/44], respectively) compared with overall rates. Ibrexafungerp was well tolerated. Adverse events were primarily gastrointestinal and mild in severity.

Conclusions

Ibrexafungerp provides a promising safe and efficacious oral treatment that mechanistically differs from current azole treatment options for acute VVC.

Evaluation of overtime phenotypic variation of yeasts in chronic vulvovaginal candidosis cases

Chronic vulvovaginal candidosis results either from reinfection or from the ability of Candida spp. to persist in the vulva and/or vagina. Persistence is usually associated with increased antifungal (mainly azoles) resistance rates, which can explain treatment failure, and/or increased expression of virulence factors by Candida spp. The aim of this study was to assess the mechanisms leading to Candida spp persistence, by studying sequential isolates from women with chronic vulvovaginal candidosis, focusing on strains genotypes, azole resistance and ability to form biofilms along the period of clinical evaluation.The strains were identified at species level by automated analysis of biochemical profiles and molecular typing evaluated by polymorphic DNA analysis. The capacity to form biofilm was assessed with a microtiter plate assay. Fluconazole susceptibility was determined by the microdilution broth assay at both pH 7 (following the recommended guideline) and pH 4.5 (as representative of vaginal pH).We studied samples from 17 clinically recurrent cases. In 53% of the chronic cases there were two or more isolates that had a phylogenetic relationship while the remaining (47%) were caused by different species. In those cases where related strains were involved in recurrence, we verified an increase in MIC at pH 7 and also an increased capacity to form biofilms over time. Significant correlation between these two parameters was observed only in cases caused by C. glabrata, evidencing the importance of these two factors to enhance persistence in the vaginal mucosa for this particular species.

LAY ABSTRACT

Chronic vulvovaginal candidosis (VVC) affects millions of women worldwide. We found that persistence of the same Candida strain on the vaginal mucosa does not account for the great majority of VVC cases. Moreover, modulation of biofilm formation and azole resistance overtime was investigated.

Treating (Recurrent) Vulvovaginal Candidiasis with Medical-Grade Honey-Concepts and Practical Considerations

Recurrent vulvovaginal candidiasis (RVVC) is a relapsing vaginal fungal infection caused by Candida species. The prevalence varies among age populations and can be as high as 9%. Treatment options are limited, and in 57% of the cases, relapses occur within six months after fluconazole maintenance therapy, which is the current standard of care. The pathogenesis of RVVC is multifactorial, and recent studies have demonstrated that the vaginal microenvironment and activity of the immune system have a strong influence on the disease. Medical-grade honey (MGH) has protective, antimicrobial, and immunomodulatory activity and forms a putative alternative treatment. Clinical trials have demonstrated that honey can benefit the treatment of bacterial and Candida-mediated vaginal infections. We postulate that MGH will actively fight ongoing infections; eradicate biofilms; and modulate the vaginal microenvironment by its anti-inflammatory, antioxidative, and immunomodulatory properties, and subsequently may decrease the number of relapses when compared to fluconazole. The MGH formulation L-Mesitran Soft has stronger antimicrobial activity against various Candida species than its raw honey. In advance of a planned randomized controlled clinical trial, we present the setup of a study comparing L-Mesitran Soft with fluconazole and its practical considerations.

In Vitro pH Activity of Ibrexafungerp against Fluconazole-Susceptible and -Resistant Candida Isolates from Women with Vulvovaginal Candidiasis

The vaginal environment with candidiasis has a pH of 3.8 to 4.5 and this has a negative effect on the activity of antifungals. Ibrexafungerp was evaluated against 187 Candida isolates, including fluconazole-sensitive and -resistant Candida albicans, Candida glabrata, Candida krusei, Candida parapsilosis, and Candida tropicalis with the media adjusted to pH 7.0 and pH 4.5. Ibrexafungerp MIC values were not adversely affected when tested at pH 4.5. Ibrexafungerp exhibited significant activity against all isolates at pH 4.5.

The antifungal activity of caspofungin in combination with antifungals or non-antifungals against Candida species in vitro and in clinical therapy

Introduction: Candida species have been regarded as global health threats due to their ability to cause invasive infections. It is challenging to treat Candida bloodstream infections, which are associated with high mortality levels. Monotherapy with antifungals is sometimes not effective against severe Candida infections, and combination therapy is needed in clinical practice.Areas covered: This review was undertaken based on data from a PubMed search for English language reports published before March 2021 by using the terms 'caspofungin,' 'Candida species,' 'combination therapy,' 'antifungal effect,' and 'novel antifungal agent.'Expert opinion: Combination therapy is an empirical strategy for treating refractory Candida infections. Caspofungin has been recommended to treat candidaemia. Caspofungin in combination therapy has some applications, while the efficacy of combination therapy in the treatment of refractory Candida infections needs more study, such as randomized controlled trials. In addition, novel compounds or drugs with potential antifungal activities have been examined, and some of them exhibit synergistic interactions with caspofungin. Thus, the antifungal activity of caspofungin in combination with antifungals or non-antifungals against Candida species in vitro and in clinical therapy is summarized.

Prevalence, species distribution and antifungal susceptibility of Candida albicans causing vaginal discharge among symptomatic non-pregnant women of reproductive age at a tertiary care hospital, Vietnam

Background

Vaginal candidiasis is frequent in women of reproductive age. Accurate identification Candida provides helpful information for successful therapy and epidemiology study; however, there are very limited data from the Vietnam have been reported. This study was performed to determine the prevalence, species distribution of yeast causing vaginal discharge and antifungal susceptibility patterns of Candida albicans among symptomatic non-pregnant women of reproductive age.

Methods

Vaginal discharge samples were collected from 462 women of reproductive age in Hanoi, Vietnam between Sep 2019 and Oct 2020. Vaginal swabs from these patients were examined by direct microscopic examination (10% KOH). CHROMagar™ Candida medium and Sabouraud dextrose agar supplemented with chloramphenicol (0.5 g/l) were used to isolate yeast, and species identification was performed using morphological tests and molecular tools (PCR and sequencing). Antifungal susceptibility testing was determined according to the Clinical and Laboratory Standards Institute guidelines (M27-A3 and M27-S4).

Results

The prevalence of vaginal yeast colonization in non-pregnant women was 51.3% of 462 participants. Nine different yeast species were identified. Among these isolates, C. albicans (51.37%) was the most frequent, followed by C. parapsilosis (25.88%), C. glabrata (11.37%), C. tropicalis (4.31%), C. krusei (3.92%), C. africana (1.57%), Saccharomyces cerevisiae (0.78%), C. nivariensis (1 isolates, 0.39%), and C. lusitaniae (1 isolates, 0.39%), respectively. Among C. albicans, all 46 isolates were 100% susceptible to micafungin, caspofungin, and miconazole. The susceptibility rates to amphotericine B, 5-flucytosine, fluconazole, itraconazole and voriconazole were 95.65, 91.30, 91.30, 82.61 and 86.95%, respectively.

Conclusions

The prevalence of VVC among symptomatic non-pregnant women of reproductive age in Vietnam was higher than many parts of the world. The high frequency of non-albicans Candida species, which were often more resistant to antifungal agents, was a notable feature. Resistance rates of vaginal C. albicans isolates to antifungal agents was low. Our findings suggest that continued surveillance of changes in species distribution and susceptibility to antifungals should be routinely screened and treated.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06192-7.

Chronic recurrent vulvovaginitis is not only due to Candida

BACKGROUND

Recurrent vulvovaginitis is a growing problem that affects millions of women worldwide. In many cases it is treated as vulvovaginal candidiasis, but there is not always microbiological confirmation.

AIMS

To determine the etiology of vulvovaginitis in a group of patients.

METHODS

This is a cross-sectional study in which the data from the medical records of 316 adult patients who consulted for vulvovaginitis were analyzed. Eighty nine percent of the cases had already suffered previous episodes.

RESULTS

The median age was 34 (265 patients were between 16 and 45 years old). Yeasts were isolated in culture from 211 (66.8%) patients, although pseudo-hyphae and yeasts were observed in only 166 samples (52.5%) in the direct microscopic examination. Multiple predisposing factors were found, among which the use of contraceptives or previous antibiotics stand out. Most of the patients (almost 90%) had been treated with antifungals, with or without microbiological confirmation. Candida albicans was isolated in 187 (88.6%) patients, followed by Candida glabrata in 6 (2.8%) patients. Association with bacterial vaginosis was found in 35.1% and with intermediate bacterial microbiota in 33.2% of the cases. A remarkably high proportion of C. albicans isolates resistant to fluconazole (80.1%) and itraconazole (58.8%) was found.

CONCLUSIONS

A microbiological analysis is essential to confirm the diagnosis of vulvovaginal candidiasis, whether simple, complicated, or recurrent. Identifying the isolated yeast species and determining its susceptibility to antifungal agents are particularly important.

Analysis of Biofilm-Related Genes and Antifungal Susceptibility Pattern of Vaginal Candida albicans and Non-Candida albicans Species

Background

Vulvovaginal candidiasis caused by Candida species is a prevalent fungal infection among women. It is believed that the pathogenesis of Candida species is linked with the production of biofilm which is considered a virulence factor for this organism. The aim of this study was molecular identification, antifungal susceptibility, biomass quantification of biofilm, and detection of virulence markers of Candida species.

Methods

We investigated the molecular identification of 70 vaginal isolates of Candida species, antifungal resistance to amphotericin B, fluconazole, itraconazole, and voriconazole according to CLSI M27-A3 and M27-S4, biofilm formation, and frequency analysis of biofilm-related ALS1, ALS3, and HWP1 genes.

Results

Our findings showed that the most common yeast isolated from vaginal discharge was C. albicans (67%), followed by the non-Candida albicans species (33%). All C. albicans complex isolates were confirmed as C. albicans by HWP-PCR, and all isolates of the C. glabrata complex were revealed to be C. glabrata sensu stricto using the multiplex PCR method. FLC resistance was observed in 23.4% of C. albicans and 7.7% of C. glabrata. The resistance rate to ITC was found in 10.6% of C. albicans. The frequency of ALS1, ALS3, and HWP1 genes among Candida species was 67.1%, 80%, and 81.4%, respectively. Biofilm formation was observed in 54.3% of Candida species, and the highest frequency detected as a virulence factor was for the ALS3 gene (97.3%) in biofilm-forming species. Discussion. Our results showed the importance of molecular epidemiology studies, investigating antifungal susceptibility profiles, and understanding the role of biofilm-related virulence markers in the pathogenesis of Candida strains.