scholarly journals Azoles resistance reversal by oridonin in Candida albicans

2020 ◽  
Author(s):  
Wenna Shi ◽  
Haisheng Chen ◽  
Hui Li ◽  
Cunxian Duan ◽  
Chuanjie Song ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Efflux Pump ◽  
Fungal Infections ◽  
Annexin V ◽  
Housekeeping Gene ◽  
Drug Efflux ◽  
Synergistic Activity ◽  
Microdilution Method ◽  
Resistance Reversal ◽  
Time Kill

Abstract Background Candida albicans (C. albicans) is a yeast causing hazardous fungal infections with high mortality, especially accompanied by resistance to azole drugs (fluconazole, itraconazole and voriconazole). To overcome the azoles resistance of C. albicans, we explored the Oridonin (ORI) with three azole drugs mainly focused on the synergistic activity. In this study, C. albicans strains were obtained from cancer patients, and the reversal of drug resistance of azole-resistant C. albicans was further studied. Methods The synergistic antifungal activities of ORI and azoles were measured by checkerboard microdilution and time-kill assays. The resistance reversal mechanisms, inhibition of drug efflux and induction of apoptosis, were investigated by flow cytometry after Annexin V-FITC/PI co-staining. The expression levels of efflux pump related genes CDR1 and CDR2 were quantitatively detected by qRT-PCR. Results The azole-resistant isolates identified by checkerboard microdilution method and time-kill curves. The efflux pump inhibition assay with ORI showed that the MIC of fluconazole (128-fold), itraconazole (64-fold) and voriconazole (250-fold) decreased significantly. The upregulation of genes coding for CDR1 and CDR2 were confirmed by qPCR with respect to the housekeeping gene ACT1 in the resistant strain. The sensitizing effect of ORI on fluconazole in the treatment of C. albicans also includes promoting apoptosis. We demonstrated that the combination of azoles with ORI exerted potent synergism and further displayed that ORI could promote the sensitization to azoles for azoles-resistant C. albicans. Conclusions We speculate that the resistance to azoles depends on the overexpression of efflux pump and its related genes CDR1 and CDR2, which reduces the accessibility of antifungal agents to C. albicans. The discovery that ORI can effectively inhibit drug efflux and promote apoptosis may provide new insights and therapeutic strategies for overcoming the increasing azole resistance in C. albicans infections.

Effects of calcineurin inhibitors, cyclosporine A and tacrolimus (FK506), on the activity of antifungal drugs against Candida spp.

2021 ◽  
Vol 70 (4) ◽  
Author(s):  
Sümeyye Şen Kaya ◽  
Nuri Kiraz ◽  
Ayşe Bariş ◽  
Deniz Turan ◽  
Yasemin Öz ◽  
...  
Keyword(s):  
Cyclosporine A ◽  
Fungal Infections ◽  
Immunosuppressive Agents ◽  
Calcineurin Inhibitors ◽  
Antifungal Drugs ◽  
Synergistic Activity ◽  
Candida Spp ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Time Kill

Introduction. The simultaneous use of antifungals with immunosuppressive agents has become a necessity for patients taking immunosuppressive therapy. However, antifungal drugs are problematic because of their limited target. Hypothesis. Scientists have been searching for new antifungals and some compounds with at least additive effects on antifungals. Calcineurin inhibitors used as immunosuppressive agents also attract attention due to their antifungal property. Aim. To evaluate the activity of two calcineurin inhibitors alone and in combination with amphotericin B (AMB), caspofungin (CAS), itraconazole (ITR), voriconazole (VOR) and fluconazole (FLU). Methodology. MICs of AMB, CAS, ITR, VOR, FLU and cyclosporine A (CsA) and tacrolimus (TAC) as calcineurin inhibitors were evaluated by the broth microdilution method against Candida albicans (n=13), C. krusei (n=7) and C. glabrata (n=10). Checkerboard and time-kill methods were performed to investigate the activity of combining calcineurin inhibitors with antifungal drugs. Results. The lowest MIC values were detected with VOR for all Candida isolates tested. Although we did not detect any inhibition for CsA or TAC alone at concentrations tested in this study, the combinations of CAS with CsA showed the highest synergistic activity (36.7%) by the checkerboard method, and CAS with CsA and ITR with TAC combinations exhibited apparent synergistic interaction by the time-kill method. However, the combinations of both CsA and TAC with AMB resulted in antagonistic interactions, especially against C. krusei isolate in time-kill testing. Conclusion. Synergistic interactions in the combinations of TAC or CsA with antifungal drugs, except for AMB, in many concentrations was found to be promising in terms of the treatment of patients with fungal infections.

scholarly journals The The Effects of Cinnamaldehyde (Cinnamon Derivatives) and Nystatin on Candida Albicans and Candida Glabrata

2019 ◽  
Vol 7 (7) ◽  
pp. 1067-1070 ◽  
Author(s):  
Sedigheh Bakhtiari ◽  
Soudeh Jafari ◽  
Jamileh Bigom Taheri ◽  
Tahereh Sadat Jafarzadeh Kashi ◽  
Zahra Namazi ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Minimum Inhibitory Concentration ◽  
Candida Species ◽  
Candida Glabrata ◽  
Inhibitory Concentration ◽  
Fungal Infections ◽  
Fungal Growth ◽  
Minimum Fungicidal Concentration ◽  
Microdilution Method

BACKGROUND: Candida species are the most common opportunistic fungal infections. Today, cinnamon plants have been considered for anti-Candida properties. AIM: This study aimed to investigate the effectiveness of cinnamaldehyde extract (from cinnamon derivatives) on Candida albicans and Candida glabrata species and comparison with nystatin. MATERIAL AND METHODS: In this study, cinnamaldehyde and nystatin were used. The specimens included Candida albicans and Candida glabrata. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were measured for each one by the microdilution method. This experiment was repeated three times. RESULTS: Cinnamaldehyde extract at a concentration of 62.5 μl/ml was able to prevent the growth of Candida albicans, at a concentration of 93.7 μl/ml, causing Candida albicans to disappear, at 48.8 μl/ml, to prevent the growth of Candida glabrata, and in the concentration of 62.5 μl/ml, causes the loss of Candida glabrata. In comparison, nystatin at 0.5 μg/ml concentration prevented the growth of Candida albicans, at concentrations of 1 μg/ml causing Candida albicans to be destroyed, at 4 μg/ml concentration to prevent the growth of Candida glabrata, and at a concentration of 8 μg/ml causes the loss of Candida glabrata. The results were the same every three times. CONCLUSIONS: Although cinnamaldehyde extract had an effect on fungal growth in both Candida albicans and Candida glabrata with a fatal effect; the effect on these two species was lower than nystatin.

scholarly journals Berberine reverses multidrug resistance in Candida albicans by hijacking the drug efflux pump Mdr1p

2020 ◽  
Author(s):  
Yaojun Tong ◽  
Nuo Sun ◽  
Xiangming Wang ◽  
Qi Wei ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Multidrug Resistance ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Multidrug Resistant ◽  
Major Facilitator Superfamily ◽  
Drug Efflux ◽  
Multidrug Efflux Pump ◽  
Drug Efflux Pumps ◽  
Major Facilitator

AbstractClinical use of antimicrobials faces great challenges from the emergence of multidrug resistant (MDR) pathogens. The overexpression of drug efflux pumps is one of the major contributors to MDR. It is considered as a promising approach to overcome MDR by reversing the function of drug efflux pumps. In the life-threatening fungal pathogen Candida albicans, the major facilitator superfamily (MFS) transporter Mdr1p can excrete many structurally unrelated antifungals, leading to multidrug resistance. Here we report a counterintuitive case of reversing multidrug resistance in C. albicans by using a natural product berberine to hijack the overexpressed Mdr1p for its own importation. Moreover, we illustrate that the imported berberine accumulates in mitochondria, and compromises the mitochondrial function by impairing mitochondrial membrane potential and mitochondrial Complex I. It results in the selective elimination of Mdr1p overexpressed C. albicans cells. Furthermore, we show that berberine treatment can prolong the mean survival time (MST) of mice with a blood-borne dissemination of Mdr1p overexpressed multidrug resistant candidiasis. This study provided a potential direction of novel anti-MDR drug discovery by screening for multidrug efflux pump converters.

scholarly journals Candida albicans Swi/Snf and Mediator Complexes Differentially Regulate Mrr1-Induced MDR1 Expression and Fluconazole Resistance

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Zhongle Liu ◽  
Lawrence C. Myers
Keyword(s):  
Transcription Factor ◽  
Candida Albicans ◽  
Transcriptional Activation ◽  
Fungal Pathogens ◽  
Efflux Pump ◽  
Open Chromatin ◽  
Drug Efflux ◽  
Fluconazole Resistance ◽  
Content Type ◽  
Zinc Cluster

ABSTRACT Long-term azole treatment of patients with chronic Candida albicans infections can lead to drug resistance. Gain-of-function (GOF) mutations in the transcription factor Mrr1 and the consequent transcriptional activation of MDR1, a drug efflux coding gene, is a common pathway by which this human fungal pathogen acquires fluconazole resistance. This work elucidates the previously unknown downstream transcription mechanisms utilized by hyperactive Mrr1. We identified the Swi/Snf chromatin remodeling complex as a key coactivator for Mrr1, which is required to maintain basal and induced open chromatin, and Mrr1 occupancy, at the MDR1 promoter. Deletion of snf2, the catalytic subunit of Swi/Snf, largely abrogates the increases in MDR1 expression and fluconazole MIC observed in MRR1 GOF mutant strains. Mediator positively and negatively regulates key Mrr1 target promoters. Deletion of the Mediator tail module med3 subunit reduces, but does not eliminate, the increased MDR1 expression and fluconazole MIC conferred by MRR1 GOF mutations. Eliminating the kinase activity of the Mediator Ssn3 subunit suppresses the decreased MDR1 expression and fluconazole MIC of the snf2 null mutation in MRR1 GOF strains. Ssn3 deletion also suppresses MDR1 promoter histone displacement defects in snf2 null mutants. The combination of this work with studies on other hyperactive zinc cluster transcription factors that confer azole resistance in fungal pathogens reveals a complex picture where the induction of drug efflux pump expression requires the coordination of multiple coactivators. The observed variations in transcription factor and target promoter dependence of this process may make the search for azole sensitivity-restoring small molecules more complicated.

scholarly journals Berberine reverses multidrug resistance in Candida albicans by hijacking the drug efflux pump Mdr1p

2020 ◽  
Author(s):  
Yaojun Tong ◽  
Jingyu Zhang ◽  
Nuo Sun ◽  
Xiang-Ming Wang ◽  
Qi Wei ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Multidrug Resistance ◽  
Efflux Pump ◽  
Drug Efflux ◽  
Drug Efflux Pump

scholarly journals Tetracycline Effects onCandida AlbicansVirulence Factors

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
Logan McCool ◽  
Hanh Mai ◽  
Michael Essmann ◽  
Bryan Larsen
Keyword(s):  
Candida Albicans ◽  
Biofilm Formation ◽  
Efflux Pump ◽  
Direct Action ◽  
Drug Efflux ◽  
Cell Counts ◽  
Hypha Formation ◽  
Hyphal Formation ◽  
Sublethal Concentrations

Object. To determine if tetracycline, previously reported to increase the probability of developing symptomatic vaginal yeast infections, has a direct effect onCandida albicansgrowth or induction of virulent phenotypes.Method. In vitro, clinical isolates of yeast were cultivated with sublethal concentrations of tetracycline and yeast cell counts, hyphal formation, drug efflux pump activity, biofilm production, and hemolysin production were determined by previously reported methods.Results. Tetracycline concentrations above 150 μg/mL inhibitedCandida albicans, but at submicrogram/mL, a modest growth increase during the early hours of the growth curve was observed. Tetracycline did not inhibit hyphal formation at sublethal concentrations. Hypha formation appeared augmented by exposure to tetracycline in the presence of chemically defined medium and especially in the presence of human serum. Efflux pumpCDR1was upregulated and a nonsignificant trend toward increased biofilm formation was noted.Conclusion. Tetracycline appears to have a small growth enhancing effect and may influence virulence through augmentation of hypha formation, and a modest effect on drug efflux and biofilm formation, although tetracycline did not affect hemolysin. It is not clear if the magnitude of the effect is sufficient to attribute vaginitis following tetracycline treatment to direct action of tetracycline on yeast.

scholarly journals Metabolic fitness of Candida albicans is indispensable for functional drug efflux, ergosterol, and chitin biosynthesis

2020 ◽  
Author(s):  
Sandeep Hans ◽  
Zeeshan Fatima ◽  
Saif Hameed
Keyword(s):  
Drug Targets ◽  
Efflux Pump ◽  
Fungal Infections ◽  
Isocitrate Lyase ◽  
Glyoxylate Cycle ◽  
Pathogenic Fungus ◽  
Nile Red ◽  
Malate Synthase ◽  
Drug Efflux ◽  
Metabolic Fitness

Background and Purpose: The increment in fungal infections, particularly due to Candida species, is alarming due to the emergence of multidrug resistance (MDR). Hence, the identification of novel drug targets to circumvent the problem of MDR requires immediate attention. The metabolic pathway, such as glyoxylate cycle (GC), which utilizes key enzymes (isocitrate lyase [ICL] and malate synthase [MLS]), enables C. albicans to adapt under glucose-deficient conditions. This study uncovers the effect of GC disruption on the major MDR mechanisms of C. albicans as a human pathogenic fungus. Materials and Methods: For the purpose of the study, efflux pump activity was assessed by phenotypic susceptibilities in the presence of substrates rhodamine 6G (R6G) and Nile red, along with R6G extracellular concentration (527 nm). In addition, ergosterol content was estimated by the alcoholic potassium hydroxide hydrolysis method. The estimation of chitin was also accomplished by the absorbance (520 nm) of glucosamine released by acid hydrolysis. Results: The results revealed that the disruption of ICL enzyme gene (Δicl1) led to the impairment of the efflux activity of multidrug transporters belonging to the ATP-binding cassette superfamily. It was further shown that Δicl1 mutant exhibited diminished ergosterol and chitin contents. In addition, all abrogated phenotypes could be rescued in the reverting strain of Δicl1 mutant. Conclusion: Based on the findings, the disruption of GC affected efflux activity and the synthesis of ergosterol and chitin. The present study for the first time revealed that metabolic fitness was associated with functional drug efflux, ergosterol and chitin biosynthesis and validated GC as an antifungal target. However, further studies are needed to comprehend and exploit this therapeutic opportunity.

scholarly journals Synergistic mechanism for tetrandrine on fluconazole against Candida albicans through the mitochondrial aerobic respiratory metabolism pathway

2014 ◽  
Vol 63 (7) ◽  
pp. 988-996 ◽  
Author(s):  
Hui Guo ◽  
Si Ming Xie ◽  
Shui Xiu Li ◽  
Yan Jun Song ◽  
Xia Lin Lv ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Efflux Pump ◽  
Primary Source ◽  
Efflux Pumps ◽  
Synergistic Action ◽  
Mitochondrial Morphology ◽  
Drug Efflux ◽  
Respiratory Metabolism ◽  
Atp Levels ◽  
The Impact

We found that tetrandrine (TET) can reverse the resistance of Candida albicans to fluconazole (FLC) and that this interaction is associated with the inhibition of drug efflux pumps. Mitochondrial aerobic respiration, which plays a major role in C. albicans metabolism, is the primary source of ATP for cellular processes, including the activation of efflux pumps. However, it was unclear if TET exerts its synergistic action against C. albicans via its impact on the mitochondrial aerobic respiratory metabolism. To investigate this mechanism, we examined the impact of FLC in the presence or absence of TET on two C. albicans strains obtained from a single parental source (FLC-sensitive strain CA-1 and FLC-resistant strain CA-16). We analysed key measures of energy generation and conversion, including the activity of respiration chain complexes I and III (CI and CIII), ATP synthase (CV) activity, and the generation of reactive oxygen species (ROS), and studied intracellular ATP levels and the mitochondrial membrane potential (ΔΨm), which has a critical impact on energy transport. Mitochondrial morphology was observed by confocal microscopy. Our functional analyses revealed that, compared with strains treated only with FLC, TET+FLC increased the ATP levels and decreased ΔΨm in CA-1, but decreased ATP levels and increased ΔΨm in CA-16 (P<0.05). Additionally, CI, CIII and CV activity decreased by 23–48 %. The production of ROS increased by two- to threefold and mitochondrial morphology was altered in both strains. Our data suggested that TET impacted mitochondrial aerobic respiratory metabolism by influencing the generation and transport of ATP, reducing the utilization of ATP, and resulting in the inhibition of drug efflux pump activity. This activity contributed to the synergistic action of TET on FLC against C. albicans.

scholarly journals The Quorum-Sensing Molecule Farnesol Is a Modulator of Drug Efflux Mediated by ABC Multidrug Transporters and Synergizes with Drugs in Candida albicans

2011 ◽  
Vol 55 (10) ◽  
pp. 4834-4843 ◽  
Author(s):  
Monika Sharma ◽  
Rajendra Prasad
Keyword(s):  
Candida Albicans ◽  
Quorum Sensing ◽  
Efflux Pump ◽  
Major Facilitator Superfamily ◽  
Simultaneous Increase ◽  
Drug Efflux ◽  
Multidrug Efflux Pump ◽  
Content Type ◽  
Multidrug Transporters ◽  
Quorum Sensing Molecule

ABSTRACTOverexpression of theCaCDR1-encoded multidrug efflux pump protein CaCdr1p (Candidadrug resistance protein 1), belonging to the ATP binding cassette (ABC) superfamily of transporters, is one of the most prominent contributors of multidrug resistance (MDR) inCandida albicans. Thus, blocking or modulating the function of the drug efflux pumps represents an attractive approach in combating MDR. In the present study, we provide first evidence that the quorum-sensing molecule farnesol (FAR) is a specific modulator of efflux mediated by ABC multidrug transporters, such as CaCdr1p and CaCdr2p ofC. albicansand ScPdr5p ofSaccharomyces cerevisiae. Interestingly, FAR did not modulate the efflux mediated by the multidrug extrusion pump protein CaMdr1p, belonging to the major facilitator superfamily (MFS). Kinetic data revealed that FAR competitively inhibited rhodamine 6G efflux in CaCdr1p-overexpressing cells, with a simultaneous increase in an apparentKmwithout affecting theVmaxvalues and the ATPase activity. We also observed that when used in combination, FAR at a nontoxic concentration synergized with the drugs at their respective nonlethal concentrations, as was evident from their <0.5 fractional inhibitory concentration index (FICI) values and from the drop of 14- to 64-fold in the MIC80values in the wild-type strain and in azole-resistant clinical isolates ofC. albicans. Our biochemical experiments revealed that the synergistic interaction of FAR with the drugs led to reactive oxygen species accumulation, which triggered early apoptosis, and that both could be partly reversed by the addition of an antioxidant. Collectively, FAR modulates drug extrusion mediated exclusively by ABC proteins and is synergistic to fluconazole (FLC), ketoconazole (KTC), miconazole (MCZ), and amphotericin (AMB).

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