Anti-Candida activity and in vitro toxicity screening of antifungals complexed with β-cyclodextrin

The emergence of resistant fungal species and the toxicity of currently available antifungal drugs are relevant issues that require special consideration. Cyclodextrins inclusion complexes could optimize the antimicrobial activity of such drugs and create a controlled release system with few side effects. This study aimed to assess the in vitro toxicity and antifungal effectiveness of nystatin (Nys) and chlorhexidine (Chx) complexed or not with β-cyclodextrin (βCD). First, a drug toxicity screening was performed through the Artemia salina bioassay. Then, the minimum inhibitory concentrations (MICs) against Candida albicans were determined with the broth microdilution test. After MICs determination, the cytotoxicity of the drugs was evaluated through the methyl-thiazolyl-tetrazolium (MTT) and neutral red (NR) assays and through cell morphology analysis. The PROBIT analysis was used to determine the median lethal concentration (LC50), and the cell viability values were submitted to one-way analysis of variance(ANOVA)/Tukey (α = 0.05). Overall, the βCD-complexed antifungals were less toxic against A. salina than their raw forms, suggesting that inclusion complexes can reduce the toxicity of drugs. The MICs obtained were as follows: Nys 0.5 mg/L; Nys:βCD 4 mg/L; Chx 4 mg/L; and Chx:βCD 8 mg/L. Chx showed significant cytotoxicity (MTT: 12.9 ± 9.6%; NR: 10.6 ± 12.5%) and promoted important morphological changes. Cells exposed to the other drugs showed viability above 70% with no cellular damage. These results suggest that antifungals complexed with βCD might be a biocompatible option for the treatment of Candida-related infections.

The first case of isolation of Magnusiomyces capitatus from the oral cavity of an addicted patient

Magnusiomyces capitatus (M. capitatus) is an emerging opportunistic yeast, rarely found as a causal agent of invasive fungal infection. In this study, we report a 31-year-old man infected with M. capitatus in the oral cavity, with a history of heroin and amphetamine abuse. M. capitatus was isolated through culture and microscopic analysis and identified by PCR amplification of the ITS DNA region. Based on the in vitro antifungal susceptibility test, the lowest MICs for M. capitatus were recorded for nystatin, itraconazole, and amphotericin, while higher MICs were observed for caspofungin and fluconazole. Treatment with nystatin successfully eliminated M. capitatus and relieved the clinical symptoms. This study presents the first case of M. capitatus in a patient with substance use disorder, manifesting as a plaque-like ulcer in the oral cavity.

Fluorescent styrenes for mitochondrial imaging and viscosity sensing

Fluorophores bearing cationic pendants, such as the pyridinium group, tend to preferentially accumulate in mitochondria, whereas those with pentafluorophenyl groups display a distinct affinity for the endoplasmic reticulum. In this study, we designed fluorophores incorporating pyridinium and pentafluorophenyl pendants and examined their impact on sub-cellular localization. Remarkably, the fluorophores exhibited a notable propensity for the mitochondrial membrane. Furthermore, these fluorophores revealed dual functionality by facilitating the detection of viscosity changes within the sub-cellular environment and serving as heavy-atom-free photosensitizers. With easy chemical tunability, wash-free imaging, and a favorable signal-to-noise ratio, these fluorophores are valuable tools for imaging mitochondria and investigating their cellular processes.

Anticandidal Efficacy of Erythrosine with Nano-TiO2 and Blue LED-Mediated Photodynamic Therapy against Candida albicans Biofilms on Acrylic Resin: A Preliminary Study

OBJECTIVE

 Incorporating an enhancer such as nano-titanium dioxide into antimicrobial photodynamic therapy can improve treatment outcome.This study aimed to compare the anticandidal efficacy of photodynamic therapy by erythrosine with nano-titanium dioxide (nano-TiO2) stimulated by a blue light emitting diode with three standard dental antifungal agents.

MATERIALS AND METHODS

 Candida albicans biofilms on acrylic resin plates were treated for 15 minutes with either nystatin, fluconazole, Polident, 220µM erythrosine + 1% (w/w) nano-TiO2 + 15 J/cm2 blue light photodynamic therapy (Ery PDT), or distilled water. For the Ery PDT group, blue light was applied for 1 minute after incubation. After 1, 3, and 6 hours, the colony forming units in log10 (log10CFU/mL) were compared. The ultrastructure of C. albicans on the acrylic resin plates treated with erythrosine + nano-TiO2 + blue light was examined using transmission electron microscopy at magnification of 30,000x.

RESULTS

 After 1 hour, nystatin, Polident, and Ery PDT indifferently inhibited C. albicans. At 6 hours, Ery PDT reduced the number of viable C. albicans in biofilms by 0.28log10 CFU/mL, which was equal to the effect of fluconazole and Polident. Transmission electron microscopy demonstrated that Ery PDT altered the C. albicans cell morphology by inducing cell wall/membrane rupture.

CONCLUSION

 Photodynamic therapy with erythrosine + nano-TiO2 + blue light at low light power density (15 J/cm2) was as effective at inhibiting C. albicans biofilm on acrylic resin as fluconazole and Polident.

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.

Effectiveness of fluconazole as antifungal prophylaxis in cancer patients undergoing chemotherapy, radiotherapy, or immunotherapy: systematic review and meta-analysis

This review assessed the effectiveness of fluconazole as antifungal prophylaxis on the incidence of oral fungal diseases in patients undergoing cancer treatment. The secondary outcomes evaluated were the adverse effects, discontinuation of cancer therapy due to oral fungal infection, mortality by a fungal infection, and the mean duration of antifungal prophylaxis. Twelve databases and records were searched. The RoB 2 and ROBINS I tools were used to assess the risk of bias. The relative risk (RR), risk difference, and standard mean difference (SMD) were applied with 95% confidence intervals (CI). The certainty of the evidence was determined by GRADE. Twenty-four studies were included in this systematic review. In randomized controlled trials pooling, fluconazole was a protective factor for the primary outcome (RR = 0.30; CI: 0.16, 0.55; p < 0.01, vs placebo). Compared to other antifungals, fluconazole was only more effective than the subgroup of amphotericin B and nystatin (alone or in combination) (RR = 0.19; CI: 0.09, 0.43; p < 0.01). Fluconazole was also a protective factor in non-randomized trials pooling (RR = 0.19; CI: 0.05, 0.78; p = 0.02, vs untreated). The results showed no significant differences for the secondary outcomes. The certainty of the evidence was low and very low. In conclusion, prophylactic antifungals are necessary during cancer treatment, and fluconazole was shown to be more effective in reducing oral fungal diseases only compared with the subgroup assessing amphotericin B and nystatin, administered alone or in combination.

Evaluation and comparison of antifungal effect of voriconazole with nystatin on candida species derived from neoplastic patients undergoing maxillofacial radiotherapy

Background

Radiotherapy is a common treatment for head-and-neck malignancies and causes complications such as oral candidiasis and the change of oral Candida species from albicans to nonalbicans. Voriconazole has acceptable antifungal effect. The aim of this study was to determine and compare the antifungal effect of nystatin with voriconazole on these species.

Materials and Methods

The samples used in this in vitro study were identified by polymerase chain reaction-restriction fragment length polymorphism from patients before and 2 weeks after head-and-neck radiotherapy in Seyed Al-Shohada Hospital. The antifungal effect of nystatin and voriconazole was determined by microdilution method and measurement of the minimum inhibitory concentration (MIC) and the minimum fungicidal concentration, and the results were analyzed by Mann-Whitney analysis.

Results

The results showed that all species before and after radiotherapy showed 100% sensitivity to nystatin. Prior to radiotherapy, 57.1% of albicans species isolated were in the sensitive range (MIC ≤1) and 42.9% were in the dose-dependent range (MIC = 2) to voriconazole. After radiotherapy, 58.3% of albicans species were in the sensitive range and 41.7% of these species were in the dose-dependent range to voriconazole.

Conclusion

The results of the present study showed that before radiotherapy, all species were sensitive to nystatin, while a percentage of albicans and nonalbicans were resistant to voriconazole. In the 2nd week of radiotherapy similar to prior to radiotherapy, all species isolated from patients were sensitive to nystatin, while a percentage of albicans and nonalbicans were resistant to voriconazole.

Antifungal Susceptibility of Oral Candida Isolates from Mother-Infant Dyads to Nystatin, Fluconazole, and Caspofungin

The carriage of Candida albicans in children's oral cavities is associated with a higher risk for early childhood caries, so controlling this fungus in early life is essential for preventing caries. In a prospective cohort of 41 mothers and their children from 0 to 2 years of age, this study addressed four main objectives: (1) Evaluate in vitro the antifungal agent susceptibility of oral Candida isolates from the mother-child cohort; (2) compare Candida susceptibility between isolates from the mothers and children; (3) assess longitudinal changes in the susceptibility of the isolates collected between 0 and 2 years; and (4) detect mutations in C. albicans antifungal resistance genes. Susceptibility to antifungal medications was tested by in vitro broth microdilution and expressed as the minimal inhibitory concentration (MIC). C. albicans clinical isolates were sequenced by whole genome sequencing, and the genes related to antifungal resistance, ERG3, ERG11, CDR1, CDR2, MDR1, and FKS1, were assessed. Four Candida spp. (n = 126) were isolated: C. albicans, C. parapsilosis, C. dubliniensis, and C. lusitaniae. Caspofungin was the most active drug for oral Candida, followed by fluconazole and nystatin. Two missense mutations in the CDR2 gene were shared among C. albicans isolates resistant to nystatin. Most of the children's C. albicans isolates had MIC values similar to those from their mothers, and 70% remained stable on antifungal medications from 0 to 2 years. For caspofungin, 29% of the children's isolates showed an increase in MIC values from 0 to 2 years. Results of the longitudinal cohort indicated that clinically used oral nystatin was ineffective in reducing the carriage of C. albicans in children; novel antifungal regimens in infants are needed for better oral yeast control.

Investigation of the antifungal effects of curcumin against nystatin-resistant Candida albicans

Background

Emergence of nystatin-resistant Candida albicans (C. albicans) strains has raised some concerns in the recent years. Recent scientific evidence proves that turmeric, especially curcumin, has anti-inflammatory and anti-fungal activity. The aim of this study was the investigation of the antifungal effects of curcumin against nystatin-resistant C. albicans.

Materials and Methods

This in vitro, experimental study evaluated standard-strain (ATCC 16201) and 10 nystatin-resistant C. albicans strains. The antifungal activity and minimum inhibitory concentration (MIC) of curcumin were evaluated using the CLSI-M27-A3, and the MIC of curcumin was compared with that of nystatin. The results were analyzed using the one-way ANOVA.

Results

The MIC of curcumin was 15.6, 32.25, 15.6, 7.8, 32.25, 15.6, 15.6, 15.6, 32.25, and 15.6 μg/mL for the 10 resistant strains and 62.5 μg/mL for the standard strain of C. albicans. Curcumin in the above-mentioned concentrations significantly inhibited the proliferation of nystatin-resistant C. albicans strains (P < 0.001).

Conclusion

According to this research, it was shown that curcumin with MIC value of 7.8-32.25 μg/mL has inhibitory effects on nystatin-resistant C. albicans strains.

Comparison of tea tree oil 5%, tea tree oil 10%, and nystatin inhibition zones against vaginal Candida isolates in pregnancy

INTRODUCTION

Vulvovaginal candidiasis (VVC) in pregnancy frequently develops into recurrent infections. Clinical study suggests that conventional topical treatments for VVC are not always enough to eradicate Candida spp. from the vaginal microenvironment. This study aimed to evaluate the antifungal activity of tea tree oil (TTO) 5% and TTO 10% against Candida species causing VVC in pregnancy.

METHODOLOGY

In vitro experimental study was conducted in the Mycology Laboratory at Dermatovenereology Outpatient Clinic Dr. Soetomo General Hospital Surabaya. Eighteen isolates of Candida species were isolated from the vaginal thrush of 15 pregnant women diagnosed with VVC from March to May 2021. Antifungal susceptibility of TTO 5% and TTO 10% was evaluated by the disc diffusion method, with the inhibitory zone diameter as the main outcome.

RESULTS

The mean inhibitory zone diameter of TTO 5%, TTO 10%, and nystatin against all Candida spp. was 7.26 mm, 8.64 mm, and 25.57 mm, respectively (p < 0.001). The mean inhibitory zone diameter of TTO 5%, TTO 10%, and nystatin tend to be larger in C. albicans compared to the non-albicans, but the difference is not significant. Nystatin displayed the largest mean inhibitory zone diameters compared to TTO 5% and TTO 10% (p < 0.001) in all Candida species. Increased concentration from TTO 5% to TTO 10% resulted in a slight increment in the mean inhibitory zone diameters in all-Candida species (p = 0.001).

CONCLUSIONS

Tea Tree Oil displayed antifungal activity against Candida species causing VVC in pregnancy. Further studies are required to investigate optimal TTO concentrations as a VVC treatment in pregnancy.

Semisynthetic Amides of Amphotericin B and Nystatin A(1): A Comparative Study of In Vitro Activity/Toxicity Ratio in Relation to Selectivity to Ergosterol Membranes

Polyene antifungal amphotericin B (AmB) has been used for over 60 years, and remains a valuable clinical treatment for systemic mycoses, due to its broad antifungal activity and low rate of emerging resistance. There is no consensus on how exactly it kills fungal cells but it is certain that AmB and the closely-related nystatin (Nys) can form pores in membranes and have a higher affinity towards ergosterol than cholesterol. Notably, the high nephro- and hemolytic toxicity of polyenes and their low solubility in water have led to efforts to improve their properties. We present the synthesis of new amphotericin and nystatin amides and a comparative study of the effects of identical modifications of AmB and Nys on the relationship between their structure and properties. Generally, increases in the activity/toxicity ratio were in good agreement with increasing ratios of selective permeabilization of ergosterol- vs. cholesterol-containing membranes. We also show that the introduced modifications had an effect on the sensitivity of mutant yeast strains with alterations in ergosterol biosynthesis to the studied polyenes, suggesting a varying affinity towards intermediate ergosterol precursors. Three new water-soluble nystatin derivatives showed a prominent improvement in safety and were selected as promising candidates for drug development.

Alginate oligosaccharides enhance the antifungal activity of nystatin against candidal biofilms

Background

The increasing prevalence of invasive fungal infections in immuno-compromised patients is a considerable cause of morbidity and mortality. With the rapid emergence of antifungal resistance and an inadequate pipeline of new therapies, novel treatment strategies are now urgently required.

Methods

The antifungal activity of the alginate oligosaccharide OligoG in conjunction with nystatin was tested against a range of Candida spp. (C. albicans, C. glabrata, C. parapsilosis, C. auris, C. tropicalis and C. dubliniensis), in both planktonic and biofilm assays, to determine its potential clinical utility to enhance the treatment of candidal infections. The effect of OligoG (0-6%) ± nystatin on Candida spp. was examined in minimum inhibitory concentration (MIC) and growth curve assays. Antifungal effects of OligoG and nystatin treatment on biofilm formation and disruption were characterized using confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM) and ATP cellular viability assays. Effects on the cell membrane were determined using permeability assays and transmission electron microscopy (TEM).

Results

MIC and growth curve assays demonstrated the synergistic effects of OligoG (0-6%) with nystatin, resulting in an up to 32-fold reduction in MIC, and a significant reduction in the growth of C. parapsilosis and C. auris (minimum significant difference = 0.2 and 0.12 respectively). CLSM and SEM imaging demonstrated that the combination treatment of OligoG (4%) with nystatin (1 µg/ml) resulted in significant inhibition of candidal biofilm formation on glass and clinical grade silicone surfaces (p < 0.001), with increased cell death (p < 0.0001). The ATP biofilm disruption assay demonstrated a significant reduction in cell viability with OligoG (4%) alone and the combined OligoG/nystatin (MIC value) treatment (p < 0.04) for all Candida strains tested. TEM studies revealed the combined OligoG/nystatin treatment induced structural reorganization of the Candida cell membrane, with increased permeability when compared to the untreated control (p < 0.001).

Conclusions

Antimicrobial synergy between OligoG and nystatin against Candida spp. highlights the potential utility of this combination therapy in the prevention and topical treatment of candidal biofilm infections, to overcome the inherent tolerance of biofilm structures to antifungal agents.

Use of checkerboard assay to determine the synergy between essential oils extracted from leaves of Aegle marmelos (L.) Correa and nystatin against Candida albicans

Background

Candida albicans is one of the most common pathogenic yeasts, responsible for causing candidiasis. The use of conventional antifungal agents for the treatment of Candida is reported to be less effective and hence alternative therapies for the treatment are needed. Essential oils of medicinal plants may serve as a strong candidate for natural products in modern therapies.

Aim

The aim of this study was to determine the synergistic potential of essential oils extracted from leaves of Aegle marmelos (L.) Correa and a potent antifungal agent, nystatin, against three clinical isolates of C. albicans using checkerboard assay.

Materials and methods

The antifungal activity of the essential oils of A. marmelos was screened against test cultures by disc diffusion technique. Antibiograms of the test organisms were developed. To determine the minimum fungicidal concentration of the essential oil and nystatin, the broth microdilution method was employed, and a checkerboard assay was used to investigate the synergistic potential of the essential oil and nystatin against the clinical isolates under study. The data were expressed as mean ± standard deviation.

Results

The Σ fractional inhibitory concentration values were calculated as 0.12, 0.37, and 0.28 for three different strains of C. albicans used, respectively, which was <0.5, therefore, the synergy was demonstrated between essential oils and nystatin against the test cultures.

Conclusions

Combinatorial therapy of the essential oils extracted from the leaves of A. marmelos and nystatin may be considered a line of treatment for candidal infections.

Nystatin is commonly prescribed as prophylaxis in children beyond the neonatal age

The indications for nystatin as prophylaxis or treatment are limited. In the PASOAP (Pediatric Antifungal Stewardship Optimizing Antifungal Prescription) study, high use of nystatin in hospitalized children beyond the neonatal age was observed. In this report, we present the data on nystatin use in infants and children ≥ 3 months who participated in the PASOAP study. Nystatin was prescribed mainly for prophylaxis. Congenital heart disease, cystic fibrosis, and chronic renal disease were the most commonly reported conditions in children receiving prophylactic nystatin. There is sparse evidence supporting the use of nystatin prophylaxis beyond neonates; trials in specific pediatric patient groups are required.

Nystatin Effectiveness in Oral Candidiasis Treatment: A Systematic Review & Meta-Analysis of Clinical Trials

Oral candidiasis is the most common opportunistic fungal infection caused by commensal Candida species. Since there are various local and systemic predisposing factors for the disease, the treatment also varies from topical to systemic antifungal agents. Nystatin is a common antifungal agent used topically. The aim of this systematic review was to evaluate and compare the efficacy of different antifungal agents and the safety of nystatin in the treatment of oral candidiasis. Three electronic databases were searched for randomized controlled trials comparing nystatin with other anti-fungal therapies or placebo. Clinical and/or mycological cure was the outcome evaluation. A meta-analysis and descriptive study on the efficacy, treatment protocols, and safety of nystatin was also conducted. The meta-analysis included five studies, which compared the efficacy of nystatin suspensions with photodynamic therapy. A significant difference in the colony-forming units per milliliters (CFU/mL) of Candida species was observed at 60 days intervals for both palatal mucosa and denture surfaces, with both groups favoring nystatin with low heterogeneity at a 95% confidence interval. Nystatin and photodynamic therapy were found to be equally effective for the clinical remission of denture stomatitis as well as a significant reduction of CFU/mL of Candida species from dentures and palatal surfaces of the patients.

Effect of nystatin and licorice on yeasts isolated from the oral lesions of patients with cancer under chemotherapy (in vitro study)

Background

Oral candidiasis is one of the most common manifestations of patients with cancer under chemotherapy. Due to many side effects of chemical antifungal products and various advantages of herbal extracts like licorice, this study was performed to compare the antifungal effects of nystatin and licorice on yeasts isolated from oral mucosa of patients with cancer receiving chemotherapy.

Materials and Methods

In this in vitro study, a total number of 30 patients with oral candidiasis who received chemotherapy were examined. The samples were prepared by using swabs taken from the lesions, and after 48 h, they were transferred and cultured on Sabouraud dextrose agar. The antifungal effect of licorice was compared with nystatin using agar disk diffusion method. These data were entered in SPSS statistical software and were analyzed with Kruskal-Wallis and Mann-Whitney tests. (α = 5%).

Results

Four types of candida were identified among all 30 oral lesions (Candida albicans, Candida glabrata, Candida stellatoidea, and Candida SP). The mean inhibition zone diameter around nystatin showed a significant difference (P < 0.001) between C. albicans (9.486), C. glabrata (8.627), C. stellatoidea (7.00), and C. sp (7.06) but the inhibition zone diameter around licorice was almost zero in all groups.

Conclusion

Licorice extracts did not show any antifungal effects whereas nystatin showed the most antifungal effect against C. albicans.

Water-Soluble Nystatin and Derivative

Fungal infections are increasingly causing more morbidity and mortality, especially for immunocompromised people. In recent years, there is growing evidence that new medicine-resistant fungal strains are posing added challenges in the clinic. Nystatin is a known antifungal from the polyene family. Due to Nystatin limited solubility and high toxicity, it is used mainly to treat oral and dermal fungal infections. In search for new Nystatin derivatives and formulations, we obtained amide derivatives and a deoxycholate formulation that were not described previously for this compound. Furthermore, we tested the potency of the derivatives and formulation by the USP(81) method and minimum inhibitory concentration of Candida albicans and Aspergillus niger. Additionally, the in vitro toxicity and stability were tested, and it was found that the ethanol amide derivative of Nystatin was fully water-soluble (up to 100 mg/mL) with the same potency of Nystatin but with 13.5 times lower toxicity. The ethanol amide derivative of Nystatin is a promising candidate for future drug development.

Phosphodiesterase Type 5 Inhibitors Greatly Affect Physicochemical Properties of Model Lipid Membranes

Although phosphodiesterase type 5 inhibitors are widely used and well-studied drugs, the potential benefits of their application in the treatment of various diseases and new drug delivery systems, including liposome forms, are still being discussed. In this regard, the role of the lipid matrix of cell membranes in the pharmacological action of the inhibitors is of special interest. It was shown that sildenafil, vardenafil, and tadalafil caused a significant decrease in the boundary potential of model membranes composed of palmitoyloleoylphosphatidylcholine or its mixture with cholesterol, by 70–80 mV. The reduction in the membrane dipole potential induced by inhibitors led to a 20–25% increase in the conductance of cation-selective pores formed by the antimicrobial peptide gramicidin A. The addition of sildenafil or vardenafil also led to a significant decrease in the temperature of the main phase transition of dipalmytoylphosphatidylcholine, by about 1.5 °C, while tadalafil did not change the melting temperature. Sildenafil, vardenafil, and tadalafil enhanced the pore-forming activity of the antifungal polyene antibiotic nystatin by 11, 13, and 2 times, respectively. This fact might indicate the induction of membrane curvature stress by the inhibitors. The data obtained might be of special interest for the development of lipid-mediated forms of drugs.

Smart UV-spectrophotometric platforms for rapid green analysis of miconazole nitrate and nystatin in their combined suppositories and in vitro dissolution testing

Miconazole nitrate (MIC) and nystatin (NYS) combination has proven its effectiveness as a prodigious therapy to cure women's common infections; vaginal candidiasis and vaginal mycosis. Herein, six smart UV-spectrophotometric platforms depending on minimal mathematical manipulation steps were first introduced for the simultaneous green analysis of MIC and NYS in their pure forms and commercial vaginal suppositories without any preliminary separation steps. These platforms included dual-wavelength, ratio difference, mean centering of ratio spectra, first derivative ratio, ratio subtraction, and absorption correction methods. All of the aforementioned platforms could estimate MIC in a linear range of 90-900 µg/ml. While NYS was computed directly by zero-order spectrophotometry at its λ_max (304 nm) in a linear range of 1-15 µg/ml without any interference by MIC even in low or high concentrations. Dual-wavelength and zero-order spectrophotometric platforms were successfully applied to study the dissolution profile of MIC and NYS in their combined formulation in compliance with FDA recommendations without excipients interference. According to ICH guidelines, all platforms were validated regarding the accuracy, precision, and selectivity producing satisfactory results within the accepted limits. Also, the suggested platforms' results were statistically compared with each other and with those of the reported HPLC platform revealing no significant difference concerning accuracy and precision at p = .05. Accordingly, all proposed platforms are regarded as economic and eco-friendly alternatives to the expensive chromatographic platforms that utilize hazardous organic solvents during the analysis of cited drugs.

Sensitivity improvement for spectrofluorimetric determination of commonly used antifungal drug 'nystatin': application for oral suspension

In this paper, two simple, rapid and highly sensitive spectrofluorimetric methods were developed and validated for nystatin determination in its pure form and pharmaceutical dosage form (oral suspension). The first method was based on measuring the nystatin native fluorescence after dilution with isopropyl alcohol at 407 nm (excitation 303 nm). The fluoresence intensity was linearly dependant on the nystatin concentration within the specified range 50-500 ng ml^-1 . The second was based on micellar enhancement of nystatin fluorescence using sodium dodecyl sulphate (SDS). In the presence of 2% w/v SDS, an ~1.9-fold enhancement could be achieved in the relative fluorescence intensity of nystatin. The linear range for the second method was 20-100 ng ml^-1 . The limits of quantification and detection were found to be 43.23 ng ml^-1 and 14.27 ng ml^-1 (Method I), 6.08 ng ml^-1 and 2.0 ng ml^-1 (Method II). According to percentage recoveries and relative standard deviations (RSDs) obtained, the proposed methods were precise (RSDs were less than 2%), reproducible, and accurate and could be successfully applied for quantitative estimation of nystatin in its dosage form. The statistical results of this method were compared with that of the reported method and showed excellent agreement with respect to accuracy and precision.

Incorporation of Molecular Reorientation into Modeling Surface Pressure-Area Isotherms of Langmuir Monolayers

Langmuir monolayers can be assembled from molecules that change from a low-energy orientation occupying a large cross-sectional area to a high-energy orientation of small cross-sectional area as the lateral pressure grows. Examples include cyclosporin A, amphotericin B, nystatin, certain alpha-helical peptides, cholesterol oxydation products, dumbbell-shaped amphiphiles, organic-inorganic nanoparticles and hybrid molecular films. The transition between the two orientations leads to a shoulder in the surface pressure-area isotherm. We propose a theoretical model that describes the shoulder and can be used to extract the energy cost per molecule for the reorientation. Our two-state model is based on a lattice-sublattice approximation that hosts the two orientations and a corresponding free energy expression which we minimize with respect to the orientational distribution. Inter-molecular interactions other than steric repulsion are ignored. We provide an analysis of the model, including an analytic solution for one specific lateral pressure near a point of inflection in the surface pressure-area isotherm, and an approximate solution for the entire range of the lateral pressures. We also use our model to estimate energy costs associated with orientational transitions from previously reported experimental surface pressure-area isotherms.

Polyhydroxyalkanoate/Antifungal Polyene Formulations with Monomeric Hydroxyalkanoic Acids for Improved Antifungal Efficiency

Novel biodegradable and biocompatible formulations of "old" but "gold" drugs such as nystatin (Nys) and amphotericin B (AmB) were made using a biopolymer as a matrix. Medium chain length polyhydroxyalkanoates (mcl-PHA) were used to formulate both polyenes (Nys and AmB) in the form of films (~50 µm). Thermal properties and stability of the materials were not significantly altered by the incorporation of polyenes in mcl-PHA, but polyene containing materials were more hydrophobic. These formulations were tested in vitro against a panel of pathogenic fungi and for antibiofilm properties. The films containing 0.1 to 2 weight % polyenes showed good activity and sustained polyene release for up to 4 days. A PHA monomer, namely 3-hydroxydecanoic acid (C10-OH), was added to the films to achieve an enhanced synergistic effect with polyenes against fungal growth. Mcl-PHA based polyene formulations showed excellent growth inhibitory activity against both Candida yeasts (C. albicans ATCC 1023, C. albicans SC5314 (ATCC MYA-2876), C. parapsilosis ATCC 22019) and filamentous fungi (Aspergillus fumigatus ATCC 13073; Trichophyton mentagrophytes ATCC 9533, Microsporum gypseum ATCC 24102). All antifungal PHA film preparations prevented the formation of a C. albicans biofilm, while they were not efficient in eradication of mature biofilms, rendering them suitable for the transdermal application or as coatings of implants.

Development of purified cashew gum mucoadhesive buccal tablets containing nystatin for treatment of oral candidiasis

OBJECTIVE

The objective of this work was to prepare mucoadhesive buccal tablets containing nystatin and purified cashew gum for the treatment of oral candidiasis.

SIGNIFICANCE

Mucoadhesive buccal tablets containing the drug nystatin are an alternative to oral suspensions, which cause low therapeutic adherence to the treatment of oral candidiasis. Purified cashew gum has been studied as a diluent and mucoadhesive agent in tablets.

METHODS

Two batches of mucoadhesive tablets were produced, MT1 and MT 2, containing purified cashew gum, nystatin (500,000 IU), flavoring agent and with or without the presence of lubricant agent. The average weight, mechanical properties, dose uniformity, drug release profile, mucoadhesive properties and antimicrobial activity against Candida albicans were evaluated.

RESULTS

Tablets presented average weight of 329.1 ± 3.1 mg (MT1) and 334.6 ± 1.5 mg (MT2), hardness of 9.8 ± 0.8 KgF (MT1) and 8.3 ± 0.4 KgF (MT2), friability of 0.2% (MT1 and MT2), and dose uniformity of 102.20 ± 1.17% (MT1) and 99.06 ± 7.40% (MT2). MT1 and MT2 were able to swell, erode, release the drug and remain adhered to the pig's cheek up to 3 h for batch MT1 and 4 h for batch MT2, and the amount of nystatin released since the beginning of the test in both batches was sufficient to inhibit the growth of the fungus.

CONCLUSIONS

Therefore, the proposed formulation proved to be very promising and met all the studied criteria, showing to be ideal for the treatment of oral candidiasis.

Biofilm Infections

The aim of this study was to improve the treatment of Candida albicans biofilms through the use of nystatin solid dispersions developed using maltodextrins as a hyperosmotic carrier. Characterization studies by differential scanning calorimetry, X-ray diffraction, dissolution studies, and particle size analysis were performed to evaluate changes in nystatin crystallinity. Antifungal activity and anti-biofilm efficacy were assessed by microbiological techniques. The results for nystatin solid dispersions showed that the enhancement of antifungal activity may be related to the high proportions of maltodextrins. Anti-biofilm assays showed a significant reduction (more than 80%) on biofilm formation with SD-N:MD [1:6] compared to the nystatin reference suspension. The elaboration process and physicochemical properties of SD-N:MD [1:6] could be a promising strategy for treatment of Candida biofilms.

Is the Membrane Lipid Matrix a Key Target for Action of Pharmacologically Active Plant Saponins?

This study was focused on the molecular mechanisms of action of saponins and related compounds (sapogenins and alkaloids) on model lipid membranes. Steroids and triterpenes were tested. A systematic analysis of the effects of these chemicals on the physicochemical properties of the lipid bilayers and on the formation and functionality of the reconstituted ion channels induced by antimicrobial agents was performed. It was found that digitonin, tribulosin, and dioscin substantially reduced the boundary potential of the phosphatidylcholine membranes. We concluded that saponins might affect the membrane boundary potential by restructuring the membrane hydration layer. Moreover, an increase in the conductance and lifetime of gramicidin A channels in the presence of tribulosin was due to an alteration in the membrane dipole potential. Differential scanning microcalorimetry data indicated the key role of the sapogenin core structure (steroid or triterpenic) in affecting lipid melting and disordering. We showed that an alteration in pore forming activity of syringomycin E by dioscin might be due to amendments in the lipid packing. We also found that the ability of saponins to disengage the fluorescent marker calcein from lipid vesicles might be also determined by their ability to induce a positive curvature stress.

Bursting the Virulence Traits of MDR Strain of Candida albicans Using Sodium Alginate-based Microspheres Containing Nystatin-loaded MgO/CuO Nanocomposites

INTRODUCTION

Candida albicans is a major opportunistic pathogen that causes a wide range of human infections. Currently available therapeutic agents are limited for treating these fungal infections due to multidrug resistance as well as their nonbiodegradability, poor biocompatibility and toxicity. In order to battle these limitations, we have synthesized a polymeric system as microcarriers to deliver the antifungal drug. The objective of the present study was to immobilize MgO/CuO nanocomposite and nystatin-loaded MgO/CuO nanocomposites in nontoxic, nonimmunogenic, biodegradable and biocompatible sodium alginate microspheres for the first time.

MATERIALS AND METHODS

Nanoparticle-loaded sodium alginate microspheres were prepared by ionotropic gelation technique using calcium chloride as a cross-linker. Synthesized microspheres were characterized using standard characterization techniques and were evaluated for biological activity against MDR strain of C. albicans.

RESULTS

Characterization of microspheres by Fourier-transform infrared spectroscopy confirmed loading of Nys-MgO/CuO NPs, scanning electron microscopy (SEM) revealed rough spherical beads with a highly porous surface having an average size in the range of 8-10 µm. X-ray diffraction (XRD) analyzed its semicrystalline structure. Entrapment efficiency of Nys-MgO/CuO NPs was 80% and release kinetic study revealed sustained and prolonged release of drug in pH 5.5. Flow cytometry analysis showed yeast cell death caused by Nys-MgO/CuO MS exhibits late apoptotic features. In cytotoxicity assay 5-14 mg of microspheres did not cause hemolysis. Microspheres reduced virulence traits of C. albicans such as germ tube and biofilm formation were compromised at concentration of 5 mg/mL. Antimicrobial assessment results revealed a pronounced inhibitory effect against C. albicans.

CONCLUSION

The in vitro experiments have shown promising results based on good stability, Nys-MgO/CuO NP-encapsulated microspheres can be used as a prolonged controlled release system against MDR pathogenic C. albicans.

Oropharyngeal candidiasis outcomes in renal transplant recipients receiving nystatin versus no antifungal prophylaxis

OBJECTIVE

To compare the incidence of oropharyngeal candidiasis (OC), or thrush, in renal transplant recipients receiving nystatin versus no antifungal prophylaxis.

METHODS

This was a single-center, retrospective, non-inferiority study of adult renal transplant recipients (RTRs) who received nystatin for 30 days for OC prophylaxis (nystatin group) or no antifungal prophylaxis therapy (No PPX group). The primary outcome was the incidence of OC within 3 months post-transplant. Secondary outcomes included time to OC occurrence and severity of OC. The pre-specified non-inferiority margin was 10%.

RESULTS

The incidence of OC within 3 months post-transplant among 257 RTRs was 7.8% (10/128) in the No PPX group and 4.7% (6/129) RTRs in the nystatin group, a risk difference of 3.2% (95% CI, -2.7% to 9.1%, non-inferiority P = .04). The median time to OC was 7.5 days (IQR 6.3-34.3 days) in the nystatin group and 9.5 days (IQR 5.3-30.5 days) in the No PPX group (P = .64). Esophageal candidiasis was observed in 10% (1/10) of RTRs with OC in the No PPX group compared to 16.7% (1/6) RTRs in the nystatin group (P = 1.00). All RTRs with OC achieved symptom resolution with fluconazole and/or nystatin. Two patients in the No PPX group required readmission for decreased oral intake, and OC was diagnosed and treated during their hospital day.

CONCLUSIONS

In this retrospective study of adult RTRs, the absence of antifungal prophylaxis demonstrated non-inferiority to 30-day nystatin prophylaxis at reducing the incidence of OC within 3 months of transplant. OC prophylaxis may not be warranted after renal transplant.

Insights into specificity and catalytic mechanism of amphotericin B/nystatin thioesterase

Polyene polyketides amphotericin B (AMB) and nystatin (NYS) are important antifungal drugs. Thioesterases (TEs), located at the last module of PKS, control the release of polyketides by cyclization or hydrolysis. Intrigued by the tiny structural difference between AMB and NYS, as well as the high sequence identity between AMB TE and NYS TE, we constructed four systems to study the structural characteristics, catalytic mechanism, and product release of AMB TE and NYS TE with combined MD simulations and quantum mechanics/molecular mechanics calculations. The results indicated that compared with AMB TE, NYS TE shows higher specificity on its natural substrate and R26 as well as D186 were proposed to a key role in substrate recognition. The energy barrier of macrocyclization in AMB-TE-Amb and AMB-TE-Nys systems were calculated to be 14.0 and 22.7 kcal/mol, while in NYS-TE-Nys and NYS-TE-Amb systems, their energy barriers were 17.5 and 25.7 kcal/mol, suggesting the cyclization with their natural substrates were more favorable than that with exchanged substrates. At last, the binding free energy obtained with the MM-PBSA.py program suggested that it was easier for natural products to leave TE enzymes after cyclization. And key residues to the departure of polyketide product from the active site were highlighted. We provided a catalytic overview of AMB TE and NYS TE including substrate recognition, catalytic mechanism and product release. These will improve the comprehension of polyene polyketide TEs and benefit for broadening the substrate flexibility of polyketide TEs.

[Vancomycin-based Lowenstein-Jensen selective medium for reducing contamination of mycobacterial cultures by spore-forming bacteria]

INTRODUCTION

despite the development of new methods, culture on solid medium is the gold standard for the diagnosis of tuberculosis. However, this method is associated with increased rates of contamination of cultures by spore-forming bacteria. These bacteria are generally sensitive to vancomycin and to a combinsation of vancomycin, colistin, nystatin, and trimethoprim (VCNT). The purpose of this study was to assess the effectiveness of VCNT-based selective Lowenstein-Jensen (LJ) medium in reducing contamination of cultures by spore-forming bacteria.

METHODS

sputum samples, collected from the 120 TB and non-TB patients included in the study between October 2016 and May 2017, were decontaminated with the modified Petroff method. Decontamination pellets were inoculated onto conventional LJ media and selective VCNT-based LJ medium containing 10µg/ml vancomycin. Fifteen strains of spore-forming bacteria were inoculated onto the same media in order to assess their sensitivity to VCNT.

RESULTS

the contamination of cultures on VCNT-based LJ medium containing 10µg/ml of vancomycin and LJ medium were 11.66% (14/120) and 39.16% (47/120) with p <0.0001, respectively. Sensitivity of spore-forming bacteria to VCNT decreased with the increasing of culture incubation time.

CONCLUSION

VCNT-based selective LJ medium containing 10µg/ml vancomycin led to a significant reduction in the rate of culture contamination. This environment could contribute to improve the quality of mycobacterial cultures and thus bacteriological diagnosis of tuberculosis.

A Comparison of Triamcinolone Acetonide Econazole Cream and Nystatin Suspension in Treatment of Otomycosis

OBJECTIVES/HYPOTHESIS

To compare the efficacy and adverse effects of triamcinolone acetonide econazole cream and nystatin suspension in the treatment of otomycosis, and to determine the clinical features, predisposing factors, and etiology of otomycosis.

STUDY DESIGN

A prospective study.

METHODS

A prospective clinical trial was conducted on 786 patients diagnosed with otomycosis. The study population was randomly divided into two treatment groups of triamcinolone acetonide econazole cream (TAEC) and nystatin suspension in a 1:1 ratio. After clearing all fungal deposits in the external auditory canal, the antimycotic drugs were locally applied for at least 2 weeks. The efficacy and adverse effects were compared between the two antifungal reagents by statistical analysis. Meanwhile, patient clinical data were collected to find out the clinical features, predisposing factors, and etiology.

RESULTS

Pruritis was the most common symptom and Aspergillus niger was the leading fungal pathogen. There was high association (44.5%) of otomycosis with a history of unclean ear picking. The cure rate was 97.6% in the TAEC group and 73.5% in the nystatin group (P < .01). Treatment with TAEC resulted in 2.4% of patients complaining of discomforts (irritant dermatitis, otalgia, or headache) versus 59.8% of patients complaining discomforts treated with nystatin (P < .01). The residue rate of antifungals was 1.9% in the TAEC group and 89.9% in the nystatin group (P < .01) at the end of treatment.

CONCLUSIONS

Thoroughly cleaning of the external auditory canal followed by local use of TAEC under endotoscope is an effective, convenient, and well-tolerated treatment for otomycosis.

LEVEL OF EVIDENCE

1 Laryngoscope, 131:E1640-E1646, 2021.

Identification of Candida Species and Antifungal Susceptibility in Cancer Patients with Oral Lesions in Ahvaz, Southern West of Iran

Background

Oral candidiasis is a common disease in cancer patients subject to chemotherapy. The aim of this study was to evaluate the risk factors of rising oral candidiasis incidence and to identify the Candida species isolated from oral lesions of cancer patients and their antifungal sensitivity.

Materials and Methods

A total of 645 patients with cancer were examined. Several Candida species were isolated from specimens and identified by morphological and molecular methods. The susceptibility of isolates to amphotericin B, fluconazole, and nystatin was also investigated.

Results

A total of 74 isolates of Candida were recovered from oral cavity of 61 cancer patients with oral candidiasis. The isolates included Candida albicans (n = 56; 75.5%), Candida glabrata (n = 4; 5.4%), Candida krusei (n = 5; 7%), Candida tropical (n = 7; 9.4%), and Candida kefyr (n = 2; 2.7%). A total (n = 72; 98.65%) of isolates were susceptible to nystatin, (n = 58; 78.4%) of them were susceptible to fluconazole, and (n = 8; 10.8%) of susceptible dose-dependent isolates were specified, (n = 46; 62.16%) of isolates were susceptible to amphotericin B.

Conclusion

Finally, in addition to emphasis on topical nystatin application in the first stage of oral candidiasis in these patients, using alternative systemic drugs such as fluconazole and amphotericin B can be considered for the resistant candida isolates to nystatin.

Amphotericin B Specifically Induces the Two-Component System LnrJK: Development of a Novel Whole-Cell Biosensor for the Detection of Amphotericin-Like Polyenes

The rise of drug-resistant fungal pathogens urges for the development of new tools for the discovery of novel antifungal compounds. Polyene antibiotics are potent agents against fungal infections in humans and animals. They inhibit the growth of fungal cells by binding to sterols in the cytoplasmic membrane that subsequently causes pore formation and eventually results in cell death. Many polyenes are produced by Streptomycetes and released into the soil environment, where they can then target fungal hyphae. While not antibacterial, these compounds could nevertheless be also perceived by bacteria sharing the same habitat and serve as signaling molecules. We therefore addressed the question of how polyenes such as amphotericin B are perceived by the soil bacterium, Bacillus subtilis. Global transcriptional profiling identified a very narrow and specific response, primarily resulting in strong upregulation of the lnrLMN operon, encoding an ABC transporter previously associated with linearmycin resistance. Its strong and specific induction prompted a detailed analysis of the lnrL promoter element and its regulation. We demonstrate that the amphotericin response strictly depends on the two-component system LnrJK and that the target of LnrK-dependent gene regulation, the lnrLMN operon, negatively affects LnrJK-dependent signal transduction. Based on this knowledge, we developed a novel whole-cell biosensor, based on a P_lnrL-lux fusion reporter construct in a lnrLMN deletion mutant background. This highly sensitive and dynamic biosensor is ready to be applied for the discovery or characterization of novel amphotericin-like polyenes, hopefully helping to increase the repertoire of antimycotic and antiparasitic polyenes available to treat human and animal infections.

Antifungal activity of Punicalagin-nystatin combinations against Candida albicans

OBJECTIVES

Oral candidiasis is the most common opportunistic fungal infection of oral mucosa and results from an overgrowth of Candida, especially Candida albicans. The potential anti-C. albicans and cytotoxicity of punicalagin (PCG), isolated from Punica granatum, alone or with nystatin (NYS) were evaluated.

METHODS

Activity of compounds alone or in combinations was determined against two C. albicans strains (ATCC 90028 and SC5314). Minimal inhibitory concentration (MIC)-50 and Minimum Fungicidal Concentration (MFC) were assessed by XTT assay and CFU counts, respectively. For combinations, determination of fractional inhibitory concentration index was performed. Ergosterol pathway was investigated as a possible PCG antifungal mechanism. Cytotoxicity assays were undertaken on human primary oral keratinocytes and gingival fibroblasts incubated with antifungal concentrations of PCG and/or NYS for 24 hr.

RESULTS

Combination of NYS and PCG increased antifungal efficacy, compared with compounds tested alone. Combinations 4 (PCG-6.25 μg/ml; NYS-3.9 μg/ml) and 5 (PCG-12.5 μg/ml; NYS-1.95 μg/ml) were more effective since they reduced the MIC-50 of PCG (50 μg/ml) by 8 and 4 times, respectively, increased the candidal inhibition and nullified the PCG cytotoxicity for keratinocytes. PCG antifungal mechanism did not involve ergosterol biosynthesis pathway.

CONCLUSIONS

The favorable outcomes for combination of PCG and NYS encourage further testing this therapeutic strategy against C. albicans.

Modulation of Plasma Membrane Composition and Microdomain Organization Impairs Heat Shock Protein Expression in B16-F10 Mouse Melanoma Cells

The heat shock response (HSR) regulates induction of stress/heat shock proteins (HSPs) to preserve proteostasis during cellular stress. Earlier, our group established that the plasma membrane (PM) acts as a sensor and regulator of HSR through changes in its microdomain organization. PM microdomains such as lipid rafts, dynamic nanoscale assemblies enriched in cholesterol and sphingomyelin, and caveolae, cholesterol-rich PM invaginations, constitute clustering platforms for proteins functional in signaling cascades. Here, we aimed to compare the effect of cyclodextrin (MβCD)- and nystatin-induced cholesterol modulations on stress-activated expression of the representative HSPs, HSP70, and HSP25 in mouse B16-F10 melanoma cells. Depletion of cholesterol levels with MβCD impaired the heat-inducibility of both HSP70 and HSP25. Sequestration of cholesterol with nystatin impaired the heat-inducibility of HSP25 but not of HSP70. Imaging fluorescent correlation spectroscopy marked a modulated lateral diffusion constant of fluorescently labelled cholesterol in PM during cholesterol deprived conditions. Lipidomics analysis upon MβCD treatment revealed, next to cholesterol reductions, decreased lysophosphatidylcholine and phosphatidic acid levels. These data not only highlight the involvement of PM integrity in HSR but also suggest that altered dynamics of specific cholesterol pools could represent a mechanism to fine tune HSP expression.

Nystatin Regulates Axonal Extension and Regeneration by Modifying the Levels of Nitric Oxide

Nystatin is a pharmacological agent commonly used for the treatment of oral, mucosal and cutaneous fungal infections. Nystatin has also been extensively applied to study the cellular function of cholesterol-enriched structures because of its ability to bind and extract cholesterol from mammalian membranes. In neurons, cholesterol level is tightly regulated, being essential for synapse and dendrite formation, and axonal guidance. However, the action of Nystatin on axon regeneration has been poorly evaluated. Here, we examine the effect of Nystatin on primary cultures of hippocampal neurons, showing how acute dose (minutes) of Nystatin increases the area of growth cones, and chronic treatment (days) enhances axon length, axon branching, and axon regeneration post-axotomy. We describe two alternative signaling pathways responsible for the observed effects and activated at different concentrations of Nystatin. At elevated concentrations, Nystatin promotes growth cone expansion through phosphorylation of Akt; whereas, at low concentrations, Nystatin enhances axon length and regrowth by increasing nitric oxide levels. Together, our findings indicate new signaling pathways of Nystatin and propose this compound as a novel regulator of axon regeneration.

The comparison of the effect of curcumin with nystatin on inhibition level of Candida albicans

Background

Curcumin is a kind of medicinal plant, a member of the ginger family, Zingiberaceae. As the herbal medicine has been globally demanded in recent years and due to the anti-viral, anti-inflammatory, and antifungal properties of curcumin, the present study aimed to compare the inhibitory effect of curcumin with that of nystatin on Candida albicans growth.

Methods

In this experimental study, the antifungal effect of curcumin on Candida albicans was evaluated. Candida albicans is cultivated in Agar Sabuard medium containing chlorophenic, 10-series of curcumin extract, and one 10-series of a disc impregnated with nystatin. Inside of each plate, one disc of herbal extract, one disc of nystatin as a positive control, one disc of methanol and one empty disc as negative control were placed, after 24 hrs, the inhibitory zone diameter of the herbal extract was compared with that of positive control using Mann–Whitney.

Results

The mean of inhibitory zone diameter in nystatin and curcumin was 1.04±20.46 and 1.36±0.89 mm, respectively. Mann–Whitney test shows a significant difference between the inhibitory zone diameter of these materials (P<0.001).

Conclusion

The results of this study suggested that curcumin extract did not have any effect on the inhibition of Candida albicans in laboratory environment.

Gold Nanoparticles Conjugation Enhances Antiacanthamoebic Properties of Nystatin, Fluconazole and Amphotericin B

Parasitic infections have remained a significant burden on human and animal health. In part, this is due to lack of clinically-approved, novel antimicrobials and a lack of interest by the pharmaceutical industry. An alternative approach is to modify existing clinically-approved drugs for efficient delivery formulations to ensure minimum inhibitory concentration is achieved at the target site. Nanotechnology offers the potential to enhance the therapeutic efficacy of drugs through modification of nanoparticles with ligands. Amphotericin B, nystatin, and fluconazole are clinically available drugs in the treatment of amoebal and fungal infections. These drugs were conjugated with gold nanoparticles. To characterize these gold-conjugated drug, atomic force microscopy, ultraviolet-visible spectrophotometry and Fourier transform infrared spectroscopy were performed. These drugs and their gold nanoconjugates were examined for antimicrobial activity against the protist pathogen, Acanthamoeba castellanii of the T4 genotype. Moreover, host cell cytotoxicity assays were accomplished. Cytotoxicity of these drugs and drug-conjugated gold nanoparticles was also determined by lactate dehydrogenase assay. Gold nanoparticles conjugation resulted in enhanced bioactivity of all three drugs with amphotericin B producing the most significant effects against Acanthamoeba castellanii (p ＜ 0.05). In contrast, bare gold nanoparticles did not exhibit antimicrobial potency. Furthermore, amoebae treated with drugs-conjugated gold nanoparticles showed reduced cytotoxicity against HeLa cells. In this report, we demonstrated the use of nanotechnology to modify existing clinically-approved drugs and enhance their efficacy against pathogenic amoebae. Given the lack of development of novel drugs, this is a viable approach in the treatment of neglected diseases.

Uptake and transport of pullulan acetate nanoparticles in the BeWo b30 placental barrier cell model

INTRODUCTION

Nanomedicine has shown a great potential in perinatal medicine because of its characteristics of sustained, controlled release and targeting ability; on the other hand, it may also lead to unexpected toxicities such as embryotoxicity and even malformation after crossing the placental barrier, but data concerning transplacental transport are scarce. Pullulan acetate (PA) nanoparticles (NPs) are a promising nanocarrier derived from natural polysaccharide; however, their transplacental transport ability and mechanism are unknown.

MATERIALS AND METHODS

In this study, fluorescein isothiocyanate (FITC) conjugated PA (PA-FITC) was synthesized. PA-FITC NPs were characterized by dynamic light scattering, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The cytotoxicity of PA-FITC NPs at concentrations of 15, 30, 60, 125, 250, 500, 1,000 and 2,000 μg/mL was studied by cell counting kit-8. The human chorionic gonadotrophin (HCG) cytokine assay was conducted to evaluate the biological function of BeWo b30 cells. Endocytic mechanisms of PA-FITC NPs were investigated via fluorescence analysis. The monolayer properties were characterized by TEM, tight junction staining, transepithelial electrical resistance and fluorescein sodium transportation. The transport ability was measured in the cell based transwell model by confocal imaging and SEM.

RESULTS

PA-FITC NPs were almost spherical shape with a size range of 200-300 nm. Cell viability of BeWo b30 cells was up to 100% in all groups. The concentrations of HCG increased with increasing numbers of cells and culture time, which showed the good biological function of BeWo b30 cells. PA-FITC NPs were rapidly endocytosed through caveolae-mediated endocytosis and pinocytosis, with uptake inhibition rates with nystatin (NY) and colchicines (Col) of 55% and 51% respectively. BeWo b30 cell monolayer was formed over 5 days. PA-FITC NPs were found in the cytoplasm of cells on the transwell membranes; while some NPs were found in the basolateral (fetal) compartment over 24 h.

CONCLUSION

In summary, PA-FITC NPs are nontoxic, can cross the blood-placental barrier, and show mainly internalization to BeWo b30 cells through caveolae-mediated endocytosis and pinocytosis pathways, major via the former pathway. The results could benefit the adjustment and control of the transplacental transport of nanomedicines.

Influence of a Combination of Chemical Enhancers and Iontophoresis on In Vitro Transungual Permeation of Nystatin

To promote transungual permeation of nystatin (NYST), molecule with high molecular weight, no water-soluble, amphoteric by iontophoresis. The synergic effect of the combination of cetylpyridinium chloride, CPC, or polyoxyethylene (20) sorbitan monooleate, TW80, and iontophoresis was investigated. In vitro permeation experiments were carried out through bovine hoof slices using vertical diffusion cells. A low current density (0.2 mA/cm²) was applied by introducing Ag/AgCl electrodes in the donor (anode) and receptor (cathode) chambers. The donor phase consisted of a solution, a suspension, or gel-type vehicles containing NYST and surfactants in pH 5.6 HEPES buffer. The addition of CPC to NYST suspension (SOSP) produced a fivefold increase on the permeability of the bovine hoof membrane to the drug. The application of anodal iontophoresis further improved NYST flux. Conversely, NYST transungual permeation was not influenced by TW80 either in the passive diffusion or iontophoretic flux. Furthermore, the iontophoretic treatment does not appear to induce irreversible alterations to the hoof bovine membranes. The present work demonstrated the efficacy of iontophoresis as a treatment for different nail pathologies with large molecules very slightly soluble in water without irreversibly affecting the nail structure. A synergistic effect between CPC and iontophoresis was observed.

Antifungal susceptibility testing of vulvovaginal Candida species among women attending antenatal clinic in tertiary care hospitals of Peshawar

Background

Vulvovaginal candidiasis (VVC) is considered as a pervasive gynecological problem among women worldwide. Owing to this fact, in the current study, we aimed at assessing the prevalence rate of Candida spp. causing VVC in symptomatic pregnant women and their antifungal susceptibility pattern.

Methods

This study was carried out in the tertiary care hospitals of Peshawar during the period of July 1, 2016 to December 31, 2016. The study group included 450 pregnant women in the age group of 17–44 years with symptoms of excessive vaginal discharge, pain and pruritis. In all, 108 pregnant women were culture positive for Candida. Antimicrobial susceptibility testing (AST) was conducted on specimens against various azoles and polyene F group of antifungals.

Results

Out of 108 Candida spp. isolated from vaginal swabs, there were 45 (41.7%) Candida albicans, 18 (16.7%) Candida tropicalis, 18 (16.7%) Candida krusei, 16 (14.8%) Candida glabrata and 11 (10.2%) Candida dubliniensis. According to age distribution, 27 years was the mean age. Pregnancy trimester distribution among patients was as follows: 21 (19.4%) patients were in their first trimester, 65 (60.2%) patients were in their second trimester and 22 (20.4%) patients were in the third trimester. Susceptibility of fluconazole was determined as follows: 33.3% of the Candida isolates were sensitive, 4.6% were susceptible dose dependent (SDD) and 62% were resistant. Susceptibility of Candida spp. with respect to nystatin in patients with VVC was as follows: 25% were sensitive, 16.7% were SDD and 58.3% were resistant. Susceptibility of clotrimazole was analyzed, and it was sensitive in 21.3% of patients, SDD in 19.4% of patients and resistant in 59.3% of patients. Voriconazole susceptibility was recorded to be sensitive in 85.2% of patients, SDD in 4.6% of patients and resistant in 10.2% of patients suffering from VVC. Susceptibility results for itraconazole in patients with VVC were as follows: 42.6% of patients were sensitive, 16.7% of patients were SDD, and 40.7% of patients were resistant.

Conclusion

In this study, frequency of VVC was noted to be high in the second trimester of pregnancy, with the highest frequency of C. albicans isolated, followed by C. tropicalis and C. krusei. Antifungal susceptibility testing revealed that fluconazole was exceedingly resistant against Candida species (62%), followed by clotrimazole (59.3%) and nystatin (58.3%). On the contrary, voriconazole had the highest antimicrobial activity against Candida species (85.2%).

A Drug-drug Interaction Between Cyclosporine and Nystatin

We present a case of increased cyclosporine concentration and liver function right after the combinational use of cyclosporine and nystatin, which indicated a drug-drug interaction between them. Both the concentration and liver function were decreased after discontinuation of nystatin and remained normal after taking on cyclosporine again. To our knowledge, this is the first case report of the interactions between nystatin and cyclosporine. Enteric P-glycoprotein could play an important role in the pharmacokinetic profile of cyclosporine, which needs further identification by physicians and pharmacists.

Comparison of anti-Candida activities of the ancient plants Lawsonia inermis and Ziziphus spina christi with antifungal drugs in Candida species isolated from oral cavity

Context:

Medicinal plants have reportedly fewer side effects, compared to antifungal agents.

Aims:

This study was designed to compare the anti-Candida activity of two medicinal plants with two routine antifungal agents, used in the clinics, on Candida species isolated from the oral cavity of the liver transplant patients.

Subjects and Methods:

Anti-Candida activities of ethanol extracts of Lawsonia inermis leaf and Ziziphus spina christi unripe and ripe fruit (collected from south of Iran) versus nystatin and fluconazole were evaluated using CLSI M27-A3 standard method.

Results:

The minimum inhibitory concentration (MIC) 90 values for L. inermis, Ziziphus spina christi ripe, and unripe fruits in Candida albicans were 0.1 μg/mL, 25 μg/mL, and 0.1 μg/mL, and in Candida glabrata were 0.05 μg/mL, 25 μg/mL, and 0.05 μg/mL, respectively. The MIC90 value for nystatin in both species was 0.035 μg/mL, but MIC90 value for fluconazole in C. albicans was 0.5 μg/mL and in C. glabrata was 2 μg/mL.

Conclusion:

Unripe fruits of Ziziphus spina christi and L. inermis were found more effective than fluconazole on Candida species. Ziziphus spina christi unripe fruit and L. inermis leaf have potential anti-Candida activity and can be considered as a new mouthwash agent to prevent and treat Candida infections. Further studies regarding pharmacokinetics and toxicities of these extracts are needed for their use in humans.

Role of oral nystatin prophylaxis in cardiac surgery with prolongedextracorporeal circulation

Duration >120 minutes of extracorporeal circulation (ECC) during cardiopulmonary bypass procedure was associated to an increased risk of candidemia in the intensive care unit (ICU). To evaluate oral nystatin prophylaxis in cardiac surgery considering its exclusive effect on Candida, in the absence of systemic effects and selection of resistant strains to polyene. We conducted an observational study in the postcardiac surgery ICU of Policlinico "Umberto I" of Rome. From January 2014, all patients with a prolonged ECC >120 minutes were systematically treated with oral nystatin (Prophylaxis group). This group was compared with all patients hospitalised in the same ICU, who have not received oral nystatin after ECC >120 minutes (No prophylaxis group). Overall, 672 consecutive patients were analyzed: 318 (47.3%) patients belonged to the no prophylaxis group, and 354 (52.7%) patients to the prophylaxis group. Diagnosis of candidemia was confirmed in 7 (2.2%) patients, all belonged to the no prophylaxis group. At multivariate analysis, oral nystatin prophylaxis showed a protective effect for development of candidemia after cardiac surgery. Oral nystatin prophylaxis, in patients who underwent a ECC >120 minutes, seems to reduce development of candidemia; however, the real efficacy of such prophylaxis approach requires further investigation.

Current Trends in the Use of Two Combination Antifungal/Corticosteroid Creams

Superficial fungal infections are among the most commonly managed skin problems by general practitioners. Although evidence shows combination antifungal/corticosteroid topicals are more expensive and less effective than single-agent antifungals, practitioners continue to prescribe combination agents. We examined current prescription trends of 2 combination antifungal/corticosteroid medications, Lotrisone and Mycolog-II.

Effect of Melaleuca alternifolia Mixed with Tissue Conditioners in Varying Doses on Colonization and Inhibition of Candida albicans: An In Vitro Study

AIMS AND OBJECTIVES

The study was conducted to evaluate the Colonization & Inhibition of Candida albicans in selected commercially available denture lining materials material by mixing them with varying concentrations and doses of tea tree oil.

MATERIALS AND METHODS

Five test discs of 10mm diameter and 1.5mm thickness were prepared using commercially available soft denture lining materials (Viscogel and GC-soft). Tea tree oil of varying concentrations (10%, 20%, 30%, and 40%) and doses (0.5 ml, 1.0 ml, 1.5 ml, 2.0 ml) were added during manipulation. Test discs kept in sterile artificial saliva were inoculated with Candida albicans (ATCC-2091 strain) and incubated for 6 weeks. These discs were fixed, dehydrated air dried and stained using 0.03% acridine orange stain and observed under Fluorescent microscope to count the colonies on the surface of each disc to evaluate the colonization. To evaluate inhibition, test discs were placed on the top of Sabouraud's dextrose agar inoculated with Candida albicans (ATCC-2091 strain). After incubation at 370C for 48 hours, the zone of Inhibition formed around the samples was measured.

RESULTS

The GC soft liner had higher mean colonization and lesser zone of inhibition of C.albicans when compared to Visco-gel soft liner (P < 0.001) and highest zone of inhibition observed with 2 ml volume and 40% vol/vol concentration of melaleuca alternifolia (P < 0.05).

INTERPRETATION AND CONCLUSION

By the addition of Tea Tree oil, Viscogel had good acquired good antifungal properties than GC-soft lining materials.

Effect of exposure time, particle size and uptake pathways in immune cell lysosomal cytotoxicity of mussels exposed to silver nanoparticles

Cytotoxicity evaluation of hemocytes (lysosomal membrane stability [LMS] assay) from Mytilus galloprovincialis Lamarck, exposed to a sublethal dose (100 μg/L) of two size of silver nanoparticles (AgNPs: <50 nm and <100 nm) - prior to and after inhibition of potential uptake pathways (i.e., clathrin- and caveolae-mediated endocytosis) within different times of exposure (3, 6, 12 h) - showed that there was a significant cytotoxic effect on immune cells of mussels exposed for different times to either AgNP size (p < 0.01); the greater effect was with the smaller size. However, hemocytes seemed more sensitive to the larger AgNP after clathrin-mediated endocytosis was blocked (p < 0.01); this was not so with inhibition of caveolae-mediated endocytosis. Dimethyl-sulfoxide (DMSO) did not impart a carrier-mediated effect despite an enhanced cytotoxicity when DMSO was present with AgNP. From these results, it is concluded that the immunotoxicity of AgNP in mussels was size-dependent as well as length of exposure-dependent. It was also clear that nanoparticles (NP) internalization mechanisms were a major factor underlying any toxicity.

Treatment of denture-related stomatitis improves endothelial function assessed by flow-mediated vascular dilation

INTRODUCTION

The presence of oral inflammation has recently been linked with the pathogenesis of cardiovascular diseases. While numerous studies have described links between periodontitis and endothelial dysfunction, little is known about the influence of denture-related stomatitis (DRS) on cardiovascular risk. Therefore, the aim of this study was to determine whether the treatment of DRS can lead to improvement of the clinical measures of vascular dysfunction.

MATERIAL AND METHODS

The DRS patients were treated with a local oral antifungal agent for 3 weeks. Blood pressure, flow-mediated dilatation (FMD) and nitroglycerine-mediated vascular dilatation (NMD) were measured during three study visits: before treatment, one day and two months after conclusion of antifungal therapy.

RESULTS

Flow-mediated dilatation measurements showed significant improvement of endothelial function 2 months after treatment (FMD median 5%, 95 CI: 3-8.3 vs. 11%, 95% CI: 8.8-14.4; p < 0.01), while there was no difference in control, endothelium-independent vasorelaxations (NMD; median = 15.3%, 95% CI: 10.8-19.3 vs. 12.7%, 95% CI: 10.6-15; p = 0.3). Other cardiovascular parameters such as systolic (median = 125 mm Hg; 95% CI: 116-129 vs. 120 mm Hg, 95% CI: 116-126; p = 0.1) as well as diastolic blood pressure and heart rate (median = 65.5 bpm, 95% CI: 56.7-77.7 vs. 71 bpm, 95% CI: 66.7-75; p = 0.5) did not change during or after the treatment.

CONCLUSIONS

Treatment of DRS is associated with improvement of endothelial function. Since endothelial dysfunction is known to precede the development of severe cardiovascular disorders such as atherosclerosis and hypertension, patients should be more carefully screened for DRS in general dental practice, and immediate DRS treatment should be advised.

Genome Analysis of Two Pseudonocardia Phylotypes Associated with Acromyrmex Leafcutter Ants Reveals Their Biosynthetic Potential

The attine ants of South and Central America are ancient farmers, having evolved a symbiosis with a fungal food crop >50 million years ago. The most evolutionarily derived attines are the Atta and Acromyrmex leafcutter ants, which harvest fresh leaves to feed their fungus. Acromyrmex and many other attines vertically transmit a mutualistic strain of Pseudonocardia and use antifungal compounds made by these bacteria to protect their fungal partner against co-evolved fungal pathogens of the genus Escovopsis. Pseudonocardia mutualists associated with the attines Apterostigma dentigerum and Trachymyrmex cornetzi make novel cyclic depsipeptide compounds called gerumycins, while a mutualist strain isolated from derived Acromyrmex octospinosus makes an unusual polyene antifungal called nystatin P1. The novelty of these antimicrobials suggests there is merit in exploring secondary metabolites of Pseudonocardia on a genome-wide scale. Here, we report a genomic analysis of the Pseudonocardia phylotypes Ps1 and Ps2 that are consistently associated with Acromyrmex ants collected in Gamboa, Panama. These were previously distinguished solely on the basis of 16S rRNA gene sequencing but genome sequencing of five Ps1 and five Ps2 strains revealed that the phylotypes are distinct species and each encodes between 11 and 15 secondary metabolite biosynthetic gene clusters (BGCs). There are signature BGCs for Ps1 and Ps2 strains and some that are conserved in both. Ps1 strains all contain BGCs encoding nystatin P1-like antifungals, while the Ps2 strains encode novel nystatin-like molecules. Strains show variations in the arrangement of these BGCs that resemble those seen in gerumycin gene clusters. Genome analyses and invasion assays support our hypothesis that vertically transmitted Ps1 and Ps2 strains have antibacterial activity that could help shape the cuticular microbiome. Thus, our work defines the Pseudonocardia species associated with Acromyrmex ants and supports the hypothesis that Pseudonocardia species could provide a valuable source of new antimicrobials.

Preparation, Physicochemical Characterization and Anti-fungal Evaluation of Nystatin-Loaded PLGA-Glucosamine Nanoparticles

PURPOSE

Nystatin loaded PLGA and PLGA-Glucosamine nanoparticles were formulated. PLGA were functionalized with Glucosamine (PLGA-GlcN) to enhance the adhesion of nanoparticles to Candida Albicans (C.albicans) cell walls.

METHOD

Quasi-emulsion solvent diffusion method was employed using PLGA and PLGA-GlcN with various drug-polymer ratios for the preparation of nanoparticles. The nanoparticles were evaluated for size, zeta potential, polydispersity index, drug crystallinity, loading efficiency and release properties. DSC, SEM, XRPD, ¹H-NMR, and FT-IR were performed to analyze the physicochemical properties of the nanoparticles. Antifungal activity of the nanoparticles was evaluated by determination of MICs against C.albicans.

RESULTS

The spectra of ¹H-NMR and FT-IR analysis ensured GlcN functionalization on PLGA nanoparticles. SEM characterization confirmed that particles were in the nanosize range and the particle size for PLGA and PLGA-GlcN nanoparticles were in the range of 108.63 ± 4.5 to 168.8 ± 5.65 nm and 208.76 ± 16.85 nm, respectively. DSC and XRPD analysis ensured reduction of the drug crystallinity in the nanoparticles. PLGA-GlcN nanoparticles exhibit higher antifungal activity than PLGA nanoparticles.

CONCLUSION

PLGA-GlcN nanoparticles showed more antifungal activity with appropriate physicochemical properties than pure Nystatin and PLGA nanoparticles.