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Sample records for azole antifungal agents

  1. Current and Emerging Azole Antifungal Agents

    PubMed Central

    Sheehan, Daniel J.; Hitchcock, Christopher A.; Sibley, Carol M.

    1999-01-01

    Major developments in research into the azole class of antifungal agents during the 1990s have provided expanded options for the treatment of many opportunistic and endemic fungal infections. Fluconazole and itraconazole have proved to be safer than both amphotericin B and ketoconazole. Despite these advances, serious fungal infections remain difficult to treat, and resistance to the available drugs is emerging. This review describes present and future uses of the currently available azole antifungal agents in the treatment of systemic and superficial fungal infections and provides a brief overview of the current status of in vitro susceptibility testing and the growing problem of clinical resistance to the azoles. Use of the currently available azoles in combination with other antifungal agents with different mechanisms of action is likely to provide enhanced efficacy. Detailed information on some of the second-generation triazoles being developed to provide extended coverage of opportunistic, endemic, and emerging fungal pathogens, as well as those in which resistance to older agents is becoming problematic, is provided. PMID:9880474

  2. Azole antifungal agents related to naftifine and butenafine.

    PubMed

    Castellano, S; La Colla, P; Musiu, C; Stefancich, G

    2000-06-01

    The methyl group of naftifine (1) and butenafine (2) was replaced by an azolic nucleus to obtain the new compounds 3-8 which exhibit the characteristics of both allylamine (or benzylamine) and azole antifungals. The title compounds were evaluated in vitro against several pathogenic fungi responsible for human disease. Among these, compounds 5, 6, and 8 were found to inhibit the growth of dermatophytes with a potency comparable to that of naftifine. The synthetic sequence includes the preparation of aminoazole Schiff bases, reduction, and alkylation of the corresponding secondary amines. PMID:10909187

  3. [A retrospective analysis of neurotoxicity induced by vinca alkaloids combined with azole anti-fungal agents in hematological malignancies].

    PubMed

    Osato, Yoichi; Yokoyama, Tomohisa; Saito, Yumiko; Kani, Rinako; Hayabe, Hiroko; Miyamatsu, Hironobu; Ohyashiki, Kazuma

    2011-10-01

    Vinca alkaloids (VA) are some of the key anti-tumor agents for patients with hematological malignancies, and various adverse events such as paralytic ileus, peripheral neuropathy, and constipation were now recognized as adverse VA effects. Furthermore, azole anti-fungal agents are known to enhance VA toxicity because they delay the metabolism and excretion of VA by inhibiting CYP3A4. However, their clinical relationship has not been clearly described. Therefore, we studied neurotoxicity as a possible adverse event associated with VA in patients treated with azole anti-fungal agents, retrospectively. In our study, 100 patients (479 episodes) who received VA in our department from August 2008 to December 2010 were analyzed. Adverse events attributed to the combined administration of vincristine (VCR) and azole anti-fungal agents were grade 3 paralytic ileuses in 8 patients (8 episodes), grade 3 or 4 constipation in 16 patients (16 episodes), and grade 3 peripheral neuropathy in 10 patients (16 episodes). In addition, we investigated whether temporal discontinuation of azole anti-fungal agents during VA treatment decreases the frequency of these adverse events, and detected that it is likely to help avoid neurotoxicities enhanced by itraconazole, such as severe constipation (p=0. 0308) and paralytic ileus (p=0. 0967). Our findings indicated that we should pay much more attention to these adverse events, and must select patients carefully when we administer azole anti-fungal agents to them while they are being treated with VA. PMID:21996963

  4. Modified agar dilution susceptibility testing method for determining in vitro activities of antifungal agents, including azole compounds.

    PubMed Central

    Yoshida, T; Jono, K; Okonogi, K

    1997-01-01

    In vitro activities of antifungal agents, including azole compounds, against yeasts were easily determined by using RPMI-1640 agar medium and by incubating the plates in the presence of 20% CO2. The end point of inhibition was clear by this method, even in the case of azole compounds, because of the almost complete inhibition of yeast growth at high concentrations which permitted weak growth of some Candida strains by traditional methods. MICs obtained by the agar dilution method were similar to those obtained by the broth dilution method proposed by the National Committee for Clinical Laboratory Standards. PMID:9174197

  5. Update on azole antifungals.

    PubMed

    Zonios, Dimitrios I; Bennett, John E

    2008-04-01

    This is a comprehensive, clinically oriented review of the four commercially available triazoles: fluconazole, itraconazole, voriconazole, and posaconazole. Emphasis is placed in pharmacology, drug interactions, adverse events, antifungal activity, and the evolving perspective of their clinical use. Key clinical trials are briefly discussed, and specific drug indications summarized. Fluconazole remains a valuable low-cost choice for the treatment of various fungal infections, including candidiasis and cryptococcosis. It has relatively few drug interactions and is safe but lacks activity against filamentous fungi. The use of itraconazole is historically plagued by erratic bioavailability of the oral capsule, improved with the oral solution. Drug interactions are numerous. Itraconazole exhibits significant activity against Aspergillus and the endemic fungi. Voriconazole has revolutionized the treatment of aspergillosis in severely immunocompromised patients, but its use is compromised by complicated pharmacokinetics, notable drug interactions, and relatively significant adverse events. Finally, posaconazole is the last addition to the azole armamentarium with extended antifungal spectrum, significant activity against the zygomycetes, and, apparently, optimal safety profile. Posaconazole has a significant role for the prophylaxis of invasive fungal infections in severely immunocompromised patients. Multiple daily dosing, a need for fatty foods for absorption, and absence of an intravenous formulation restrict its use to selected populations. PMID:18366001

  6. The Effect of Genetic Polymorphism on the Inhibition of Azole Antifungal Agents Against CYP2C9-Mediated Metabolism.

    PubMed

    Niwa, Toshiro; Hata, Tomomi

    2016-03-01

    We investigated the effect of cytochrome P450 (CYP) 2C9 polymorphism on the inhibition of methylhydroxylation activity of tolbutamide, a typical CYP2C9 substrate, by triazole antifungal agents, fluconazole and voriconazole. Although the Michaelis constants (Km), maximal velocities (Vmax), and Vmax/Km values for CYP2C9.1 (wild type) and CYP2C9.2 (Arg144Cys) were similar and CYP2C9.3 (Ile359Leu) had a higher Km and a lower Vmax than CYP2C9.1 and CYP2C9.2, the inhibition constants of fluconazole and voriconazole against CYP2C9.2 were lower than that against CYP2C9.1 and CYP2C9.3. These results suggest that more careful administration of azole antifungals to patients with the CYP2C9*2 allele might be required because of the strong inhibitory effects. PMID:26886310

  7. New antifungal agents.

    PubMed

    Gupta, Aditya K; Tomas, Elizabeth

    2003-07-01

    Currently, use of standard antifungal therapies can be limited because of toxicity, low efficacy rates, and drug resistance. New formulations are being prepared to improve absorption and efficacy of some of these standard therapies. Various new antifungals have demonstrated therapeutic potential. These new agents may provide additional options for the treatment of superficial fungal infections and they may help to overcome the limitations of current treatments. Liposomal formulations of AmB have a broad spectrum of activity against invasive fungi, such as Candida spp., C. neoformans, and Aspergillus spp., but not dermatophyte fungi. The liposomal AmB is associated with significantly less toxicity and good rates of efficacy, which compare or exceed that of standard AmB. These factors may provide enough of an advantage to patients to overcome the increased costs of these formulations. Three new azole drugs have been developed, and may be of use in both systemic and superficial fungal infections. Voriconazole, ravuconazole, and posaconazole are triazoles, with broad-spectrum activity. Voriconazole has a high bioavailability, and has been used with success in immunocompromised patients with invasive fungal infections. Ravuconazole has shown efficacy in candidiasis in immunocompromised patients, and onychomycosis in healthy patients. Preliminary in vivo studies with posaconazole indicated potential use in a variety of invasive fungal infections including oropharyngeal candidiasis. Echinocandins and pneumocandins are a new class of antifungals, which act as fungal cell wall beta-(1,3)-D-glucan synthase enzyme complex inhibitors. Caspofungin (MK-0991) is the first of the echinocandins to receive Food and Drug Administration approval for patients with invasive aspergillosis not responding or intolerant to other antifungal therapies, and has been effective in patients with oropharyngeal and esophageal candidiasis. Standardization of MIC value determination has improved the

  8. Overview of medically important antifungal azole derivatives.

    PubMed Central

    Fromtling, R A

    1988-01-01

    Fungal infections are a major burden to the health and welfare of modern humans. They range from simply cosmetic, non-life-threatening skin infections to severe, systemic infections that may lead to significant debilitation or death. The selection of chemotherapeutic agents useful for the treatment of fungal infections is small. In this overview, a major chemical group with antifungal activity, the azole derivatives, is examined. Included are historical and state of the art information on the in vitro activity, experimental in vivo activity, mode of action, pharmacokinetics, clinical studies, and uses and adverse reactions of imidazoles currently marketed (clotrimazole, miconazole, econazole, ketoconazole, bifonazole, butoconazole, croconazole, fenticonazole, isoconazole, oxiconazole, sulconazole, and tioconazole) and under development (aliconazole and omoconazole), as well as triazoles currently marketed (terconazole) and under development (fluconazole, itraconazole, vibunazole, alteconazole, and ICI 195,739). PMID:3069196

  9. In silico and in vitro screening to identify structurally diverse non-azole CYP51 inhibitors as potent antifungal agent.

    PubMed

    Singh, Aarti; Paliwal, Sarvesh Kumar; Sharma, Mukta; Mittal, Anupama; Sharma, Swapnil; Sharma, Jai Prakash

    2016-01-01

    The problem of resistance to azole class of antifungals is a serious cause of concern to the medical fraternity and thus there is an urgent need to identify non-azole scaffolds with high affinity for lanosterol 14α-demethylase (CYP51). In view of this we have attempted to identify novel non-azole CYP51 inhibitors through the application of pharmacophore based virtual screening and in vitro evaluation. A rigorously validated pharmacophore model comprising of 2 hydrogen bond acceptor and 2 hydrophobic features has been developed and used to mine NCI database. Out of 265 retrieved hits, NSC 1215 and 1520 have been chosen on the basis of Lipinski's rule of five, fit and estimated values. Both the hits were docked into the active site of CYP51. In view of high fit value and CDocker score, NSC 1215 and 1520 have been subjected to in vitro microbiological assay. The result reveals that NSC 1215 and 1520 are active against Candida albicans, Candida parapsilosis, Candida tropicalis, and Aspergillus niger. In addition to this the absorption characteristics of both the hits have also been determined using the rat sac technique and permeation in order of NSC 1520>NSC 1215 has been observed. PMID:26579619

  10. Potentiation of Azole Antifungals by 2-Adamantanamine

    PubMed Central

    Sun, Lingmei; Lister, Ida; Keating, John; Nantel, Andre; Long, Lisa; Ghannoum, Mahmoud; North, Jeffrey; Lee, Richard E.; Coleman, Ken; Dahl, Thomas; Lewis, Kim

    2013-01-01

    Azoles are among the most successful classes of antifungals. They act by inhibiting α-14 lanosterol demethylase in the ergosterol biosynthesis pathway. Oropharyngeal candidiasis (OPC) occurs in about 90% of HIV-infected individuals, and 4 to 5% are refractory to current therapies, including azoles, due to the formation of resistant biofilms produced in the course of OPC. We reasoned that compounds affecting a different target may potentiate azoles to produce increased killing and an antibiofilm therapeutic. 2-Adamantanamine (AC17) was identified in a screen for compounds potentiating the action of miconazole against biofilms of Candida albicans. AC17, a close structural analog to the antiviral amantadine, did not affect the viability of C. albicans but caused the normally fungistatic azoles to become fungicidal. Transcriptome analysis of cells treated with AC17 revealed that the ergosterol and filamentation pathways were affected. Indeed, cells exposed to AC17 had decreased ergosterol contents and were unable to invade agar. In vivo, the combination of AC17 and fluconazole produced a significant reduction in fungal tissue burden in a guinea pig model of cutaneous candidiasis, while each treatment alone did not have a significant effect. The combination of fluconazole and AC17 also showed improved efficacy (P value of 0.018) compared to fluconazole alone when fungal lesions were evaluated. AC17 is a promising lead in the search for more effective antifungal therapeutics. PMID:23689724

  11. Effect of voriconazole and other azole antifungal agents on CYP3A activity and metabolism of tacrolimus in human liver microsomes.

    PubMed

    Zhang, Shimin; Pillai, Venkateswaran C; Mada, Sripal Reddy; Strom, Steve; Venkataramanan, Raman

    2012-05-01

    Azole antifungal agents are known to inhibit cytochrome P450 3A (CYP3A) enzymes. Limited information is available regarding the effect of voriconazole on CYP3A activity. We examined the effect of voriconazole on CYP3A activity in human liver microsomes as measured by the formation of 6β-hydroxytestosterone from testosterone. We also evaluated the interaction between voriconazole and tacrolimus, an immunosuppressive drug, using human liver microsomes. The effect of voriconazole on CYP3A activity and tacrolimus metabolism was compared to that of other azole antifungal agents. CYP3A4 activity and the metabolism of tacrolimus were measured in the absence and in the presence of various concentrations of voriconazole (0-1.43 mM), fluconazole (0-1.63 mM), itraconazole (0-14 µM) and ketoconazole (0-0.19 µM). At a concentration of 21.2 ± 15.4 µM and 29.8 ± 12.3 µM, voriconazole inhibited the formation of 6β-hydroxytestosterone from testosterone and the metabolism of tacrolimus by 50%, respectively. The rank order of inhibition of 6β-hydroxytestosterone formation from testosterone and the metabolism of tacrolimus, is ketoconazole > itraconazole > voriconazole > fluconazole. Our observations suggest that voriconazole at clinically relevant concentrations will inhibit the hepatic metabolism of tacrolimus and increase the concentration of tacrolimus more than two-fold. Close monitoring of the blood concentrations and adjustment in the dose of tacrolimus are warranted when transplant patients receiving tacrolimus are treated with voriconazole. PMID:22106961

  12. Chloroquine sensitizes biofilms of Candida albicans to antifungal azoles.

    PubMed

    Shinde, Ravikumar Bapurao; Raut, Jayant Shankar; Chauhan, Nitin Mahendra; Karuppayil, Sankunny Mohan

    2013-01-01

    Biofilms formed by Candida albicans, a human pathogen, are known to be resistant to different antifungal agents. Novel strategies to combat the biofilm associated Candida infections like multiple drug therapy are being explored. In this study, potential of chloroquine to be a partner drug in combination with four antifungal agents, namely fluconazole, voriconazole, amphotericin B, and caspofungin, was explored against biofilms of C. albicans. Activity of various concentrations of chloroquine in combination with a particular antifungal drug was analyzed in a checkerboard format. Growth of biofilm in presence of drugs was analyzed by XTT-assay, in terms of relative metabolic activity compared to that of drug free control. Results obtained by XTT-metabolic assay were confirmed by scanning electron microscopy. The interactions between chloroquine and four antifungal drugs were determined by calculating fractional inhibitory concentration indices. Azole resistance in biofilms was reverted significantly (p<0.05) in presence of 250μg/mL of chloroquine, which resulted in inhibition of biofilms at very low concentrations of antifungal drugs. No significant alteration in the sensitivity of biofilms to caspofungin and amphotericin B was evident in combination with chloroquine. This study for the first time indicates that chloroquine potentiates anti-biofilm activity of fluconazole and voriconazole. PMID:23602464

  13. Antifungal agents.

    PubMed

    Ryder, N S

    1999-12-01

    At this year's ICAAC Meeting, new data on approximately 20 different antifungal agents were presented, while no new agents were disclosed. Drugs in late development include the triazoles, voriconazole (Pfizer Ltd) and Sch-56592 (Schering-Plough Corp), and the echinocandins, caspofungin (Merck & Co Inc) and FK-463 (Fujisawa Pharmaceutical Co Ltd). In contrast to previous years, presentations on these and earlier developmental compounds were relatively modest in scope, with few significant new data. Little new information appeared on the most recent novel class of agents, the sordarins (Glaxo Wellcome plc). Early clinical results were presented for FK-463, showing acceptable tolerability and dose-dependent efficacy in AIDS-associated esophageal candidiasis. A new liposomal formulation of nystatin (Nyotran; Aronex Pharmaceuticals Inc) was shown to be equivalent to conventional amphotericin B in empiric therapy of presumed fungal infection in neutropenic patients, but with reduced toxicity. Intravenous itraconazole (Janssen Pharmaceutica NV) was an effective prophylactic therapy in invasive pulmonary aspergillosis, while oral itraconazole was discussed as a treatment for fungal infection in heart and liver transplant patients. The allylamine compound, terbinafine (Novartis AG), showed good clinical efficacy against fungal mycetoma, a serious tropical infection. A major highlight was the first presentation of inhibitors of fungal efflux pumps as a strategy for overcoming resistance. MC-510027 (milbemycin alpha-9; Microcide Pharmaceuticals Inc) and its derivatives, potentiated the antifungal activity of triazoles and terbinafine in a number of Candida spp. Another pump inhibitor, MC-005172 (Microcide Pharmaceuticals Inc) showed in vivo potentiation of fluconazole in a mouse kidney infection model. Microcide Pharmaceuticals Inc also presented inhibitors of bacterial efflux pumps. PMID:16113946

  14. Structure-based rational design, synthesis and antifungal activity of oxime-containing azole derivatives.

    PubMed

    Xu, Yulan; Sheng, Chunquan; Wang, Wenya; Che, Xiaoying; Cao, Yongbing; Dong, Guoqiang; Wang, Shengzheng; Ji, Haitao; Miao, Zhenyuan; Yao, Jianzhong; Zhang, Wannian

    2010-05-01

    In an attempt to find novel azole antifungal agents with improved activity and broader spectrum, computer modeling was used to design a series of new azoles with piperidin-4-one O-substituted oxime side chains. Molecular docking studies revealed that they formed hydrophobic and hydrogen-bonding interactions with lanosterol 14alpha-demethylase of Candida albicans (CACYP51). In vitro antifungal assay indicates that most of the synthesized compounds showed good activity against tested fungal pathogens. In comparison with fluconazole, itraconazole and voriconazole, several compounds (such as 10c, 10e, and 10i) show more potent antifungal activity and broader spectrum, suggesting that they are promising leads for the development of novel antifungal agents. PMID:20362444

  15. Interaction of Common Azole Antifungals with P Glycoprotein

    PubMed Central

    Wang, Er-jia; Lew, Karen; Casciano, Christopher N.; Clement, Robert P.; Johnson, William W.

    2002-01-01

    Both eucaryotic and procaryotic cells are resistant to a large number of antibiotics because of the activities of export transporters. The most studied transporter in the mammalian ATP-binding cassette transporter superfamily, P glycoprotein (P-gp), ejects many structurally unrelated amphiphilic and lipophilic xenobiotics. Observed clinical interactions and some in vitro studies suggest that azole antifungals may interact with P-gp. Such an interaction could both affect the disposition and exposure to azole antifungal therapeutics and partially explain the clinical drug interactions observed with some antifungals. Using a whole-cell assay in which the retention of a marker substrate is evaluated and quantified, we studied the abilities of the most widely prescribed orally administered azole antifungals to inhibit the function of this transporter. In a cell line presenting an overexpressed amount of the human P-gp transporter, itraconazole and ketoconazole inhibited P-gp function with 50% inhibitory concentrations (IC50s) of ∼2 and ∼6 μM, respectively. Cyclosporin A was inhibitory with an IC50 of 1.4 μM in this system. Uniquely, fluconazole had no effect in this assay, a result consistent with known clinical interactions. The effects of these azole antifungals on ATP consumption by P-gp (representing transport activity) were also assessed, and the Km values were congruent with the IC50s. Therefore, exposure of tissue to the azole antifungals may be modulated by human P-gp, and the clinical interactions of azole antifungals with other drugs may be due, in part, to inhibition of P-gp transport. PMID:11751127

  16. Antifungal Azoles: Structural Insights into Undesired Tight Binding to Cholesterol-Metabolizing CYP46A1.

    PubMed

    Mast, Natalia; Zheng, Wenchao; Stout, C David; Pikuleva, Irina A

    2013-07-01

    Although there are currently three generations of antifungal azoles on the market, even the third-generation agents show undesirable interactions with human cytochrome P450 (P450) enzymes. CYP46A1 is a cholesterol-metabolizing P450 in the brain that tightly binds a number of structurally distinct azoles. Previously, we determined the crystal structures of CYP46A1 in complex with voriconazole and clotrimazole, and in the present work we cocrystallized the P450 with posaconazole at 2.5 Å resolution. This long antifungal drug coordinates the P450 heme iron with the nitrogen atom of its terminal azole ring and adopts a linear configuration occupying the whole length of the substrate access channel and extending beyond the protein surface. Numerous drug-protein interactions determine the submicromolar Kd of posaconazole for CYP46A1. We compared the crystal structure of posaconazole-bound CYP46A1 with those of the P450 in complex with other drugs, including the antifungal voriconazole and clotrimazole. We also analyzed the accommodation of posaconazole in the active site of the target enzymes, CYPs 51, from several pathogenic species. These and the solution studies with different marketed azoles, collectively, allowed us to identify the determinants of tight azole binding to CYP46A1 and generate an overall picture of azole binding to this important P450. The data obtained suggest that development of CYP51-specific antifungal agents will continue to be a challenge. Therefore, structural understanding of the azole binding not only to CYPs 51 from the pathogenic species but also to different human P450s is required to deal efficiently with this challenge. PMID:23604141

  17. Candida tropicalis Antifungal Cross-Resistance Is Related to Different Azole Target (Erg11p) Modifications

    PubMed Central

    Forastiero, A.; Mesa-Arango, A. C.; Alastruey-Izquierdo, A.; Alcazar-Fuoli, L.; Bernal-Martinez, L.; Pelaez, T.; Lopez, J. F.; Grimalt, J. O.; Gomez-Lopez, A.; Cuesta, I.; Zaragoza, O.

    2013-01-01

    Candida tropicalis ranks between third and fourth among Candida species most commonly isolated from clinical specimens. Invasive candidiasis and candidemia are treated with amphotericin B or echinocandins as first-line therapy, with extended-spectrum triazoles as acceptable alternatives. Candida tropicalis is usually susceptible to all antifungal agents, although several azole drug-resistant clinical isolates are being reported. However, C. tropicalis resistant to amphotericin B is uncommon, and only a few strains have reliably demonstrated a high level of resistance to this agent. The resistance mechanisms operating in C. tropicalis strains isolated from clinical samples showing resistance to azole drugs alone or with amphotericin B cross-resistance were elucidated. Antifungal drug resistance was related to mutations of the azole target (Erg11p) with or without alterations of the ergosterol biosynthesis pathway. The antifungal drug resistance shown in vitro correlated very well with the results obtained in vivo using the model host Galleria mellonella. Using this panel of strains, the G. mellonella model system was validated as a simple, nonmammalian minihost model that can be used to study in vitro-in vivo correlation of antifungals in C. tropicalis. The development in C. tropicalis of antifungal drug resistance with different mechanisms during antifungal treatment has potential clinical impact and deserves specific prospective studies. PMID:23877676

  18. Novel micelle formulations to increase cutaneous bioavailability of azole antifungals.

    PubMed

    Bachhav, Y G; Mondon, K; Kalia, Y N; Gurny, R; Möller, M

    2011-07-30

    Efficient topical drug administration for the treatment of superficial fungal infections would deliver the therapeutic agent to the target compartment and reduce the risk of systemic side effects. However, the physicochemical properties of the commonly used azole antifungals make their formulation a considerable challenge. The objective of the present investigation was to develop aqueous micelle solutions of clotrimazole (CLZ), econazole nitrate (ECZ) and fluconazole (FLZ) using novel amphiphilic methoxy-poly(ethylene glycol)-hexyl substituted polylactide (MPEG-hexPLA) block copolymers. The CLZ, ECZ and FLZ formulations were characterized with respect to drug loading and micelle size. The optimal drug formulation was selected for skin transport studies that were performed using full thickness porcine and human skin. Penetration pathways and micellar distribution in the skin were visualized using fluorescein loaded micelles and confocal laser scanning microscopy. The hydrodynamic diameters of the azole loaded micelles were between 70 and 165nm and the corresponding number weighted diameters (d(n)) were 30 to 40nm. Somewhat surprisingly, the lowest loading efficiency (<20%) was observed for CLZ (the most hydrophobic of the three azoles tested); in contrast, under the same conditions, ECZ was incorporated with an efficiency of 98.3% in MPEG-dihexPLA micelles. Based on the characterization data and preliminary transport experiments, ECZ loaded MPEG-dihexPLA micelles (concentration 1.3mg/mL; d(n)<40nm) were selected for further study. ECZ delivery was compared to that from Pevaryl® cream (1% w/w ECZ), a marketed liposomal formulation for topical application. ECZ deposition in porcine skin following 6h application using the MPEG-dihexPLA micelles was >13-fold higher than that from Pevaryl® cream (22.8±3.8 and 1.7±0.6μg/cm(2), respectively). A significant enhancement was also observed with human skin; the amounts of ECZ deposited were 11.3±1.6 and 1.5±0.4μg/cm(2

  19. New generation azole antifungals in clinical investigation.

    PubMed

    Girmenia, Corrado

    2009-09-01

    Considerable progress in treating systemic mycoses has been achieved in the past years through development of new drugs in association with more advanced diagnostic procedures. Here, we review the pharmacological, microbiological and clinical development progress with the so-called 'second generation' triazoles: voriconazole, posaconazole, ravuconazole, isavuconazole and albaconazole. All these drugs exhibit a favourable pharmacokinetic and toxicity profile and possess high activity against resistant and emerging pathogens. However, only voriconazole and posaconazole have been adequately investigated in Phase III studies and have been approved by the regulatory agencies in the treatment and prophylaxis of invasive fungal infections, respectively. On the contrary, ravuconazole, isavuconazole and albaconazole have not been investigated in adequate clinical trials and, in the absence of proper data, the real possibilities of these agents as competitors for the treatment and prevention of invasive mycoses in the clinical setting are still unknown. The drug interactions and the variability in the absorption and/or metabolism of the triazoles, in particular voriconazole and posaconazole, may determine an unpredictable exposure of the pathogens to the antifungal treatments. Literature evidences strongly support the use of therapeutic drug monitoring for these triazoles which may be crucial for the proper management of severe invasive fungal infections. PMID:19678798

  20. Pediatric Antifungal Agents

    PubMed Central

    Cohen-Wolkowiez, Michael; Moran, Cassandra; Benjamin, Daniel K.; Smith, P Brian

    2009-01-01

    Purpose of review In immunocompromised hosts, invasive fungal infections are common and fatal. In the past decade, the antifungal armamentarium against invasive mycoses has expanded greatly. The purpose of this report is to review the most recent literature addressing the use of antifungal agents in children. Recent findings Most studies evaluating the safety and efficacy of antifungal agents are limited to adults. However, important progress has been made in describing the pharmacokinetics and safety of newer antifungal agents in children, including the echinocandins. Summary Dosage guidelines for newer antifungal agents are currently based on adult and limited pediatric data. Because important developmental pharmacology changes occur throughout childhood impacting the pharmacokinetics of these agents, antifungal studies specifically designed for children are necessary. PMID:19741525

  1. UPC2A is required for high-level azole antifungal resistance in Candida glabrata.

    PubMed

    Whaley, Sarah G; Caudle, Kelly E; Vermitsky, John-Paul; Chadwick, Sean G; Toner, Geoffrey; Barker, Katherine S; Gygax, Scott E; Rogers, P David

    2014-08-01

    Candida glabrata, the second most common cause of Candida infections, is associated with high rates of mortality and often exhibits resistance to the azole class of antifungal agents. Upc2 and Ecm22 in Saccharomyces cerevisiae and Upc2 in Candida albicans are the transcriptional regulators of ERG11, the gene encoding the target of azoles in the ergosterol biosynthesis pathway. Recently two homologs for these transcription factors, UPC2A and UPC2B, were identified in C. glabrata. One of these, UPC2A, was shown to influence azole susceptibility. We hypothesized that due to the global role for Upc2 in sterol biosynthesis in S. cerevisiae and C. albicans, disruption of UPC2A would enhance the activity of fluconazole in both azole-susceptible dose-dependent (SDD) and -resistant C. glabrata clinical isolates. To test this hypothesis, we constructed mutants with disruptions in UPC2A and UPC2B alone and in combination in a matched pair of clinical azole-SDD and -resistant isolates. Disruption of UPC2A in both the SDD and resistant isolates resulted in increased susceptibility to sterol biosynthesis inhibitors, including a reduction in fluconazole MIC and minimum fungicidal concentration, enhanced azole activity by time-kill analysis, a decrease in ergosterol content, and downregulation of baseline and inducible expression of several sterol biosynthesis genes. Our results indicate that Upc2A is a key regulator of ergosterol biosynthesis and is essential for resistance to sterol biosynthesis inhibitors in C. glabrata. Therefore, the UPC2A pathway may represent a potential cotherapeutic target for enhancing azole activity against this organism. PMID:24867980

  2. Structural Basis of Human CYP51 Inhibition by Antifungal Azoles

    SciTech Connect

    Strushkevich, Natallia; Usanov, Sergey A.; Park, Hee-Won

    2010-09-22

    The obligatory step in sterol biosynthesis in eukaryotes is demethylation of sterol precursors at the C14-position, which is catalyzed by CYP51 (sterol 14-alpha demethylase) in three sequential reactions. In mammals, the final product of the pathway is cholesterol, while important intermediates, meiosis-activating sterols, are produced by CYP51. Three crystal structures of human CYP51, ligand-free and complexed with antifungal drugs ketoconazole and econazole, were determined, allowing analysis of the molecular basis for functional conservation within the CYP51 family. Azole binding occurs mostly through hydrophobic interactions with conservative residues of the active site. The substantial conformational changes in the B{prime} helix and F-G loop regions are induced upon ligand binding, consistent with the membrane nature of the protein and its substrate. The access channel is typical for mammalian sterol-metabolizing P450 enzymes, but is different from that observed in Mycobacterium tuberculosis CYP51. Comparison of the azole-bound structures provides insight into the relative binding affinities of human and bacterial P450 enzymes to ketoconazole and fluconazole, which can be useful for the rational design of antifungal compounds and specific modulators of human CYP51.

  3. Discovery of highly potent novel antifungal azoles by structure-based rational design.

    PubMed

    Wang, Wenya; Sheng, Chunquan; Che, Xiaoying; Ji, Haitao; Cao, Yongbing; Miao, Zhenyuan; Yao, Jianzhong; Zhang, Wannian

    2009-10-15

    On the basis of the active site of lanosterol 14alpha-demethylase from Candida albicans (CACYP51), a series of new azoles were designed and synthesized. All the new azoles show excellent in vitro activity against most of the tested pathogenic fungi, which represent a class of promising leads for the development of novel antifungal agents. The MIC(80) value of compounds 8c, 8i and 8n against C. albicans is 0.001 microg/mL, indicating that these compounds are more potent than fluconazole, itraconazole and voriconazole. Flexible molecular docking was used to analyze the structure-activity relationships (SARs) of the compounds. The designed compounds interact with CACYP51 through hydrophobic, van der Waals and hydrogen-bonding interactions. PMID:19748782

  4. Synergy Between Polyvinylpyrrolidone-Coated Silver Nanoparticles and Azole Antifungal Against Drug-Resistant Candida albicans.

    PubMed

    Sun, Lingmei; Liao, Kai; Li, Yiping; Zhao, Lei; Liang, Sai; Guo, Dan; Hu, Jun; Wang, Dayong

    2016-03-01

    In the clinical practice, resistance of Candida albicans to antifungal agents has frequently emerged. Silver-nanoparticles (Ag-NPs) have been demonstrated to have the antifungal property. We investigated the potential for synergy between polyvinylpyrrolidone (PVP)-coated Ag-NPs and azole antifungal, such as fluconazole or voriconazole, against drug-resistant C. albicans strain CA10. When antifungal agent was examined alone, fluconazole and voriconazole did not kill drug-resistant C. albicans, and PVP-coated Ag-NPs had only the moderate killing ability. In contrast, the combinational treatment of PVP-coated Ag-NPs with fluconazole or voriconazole was effective in being against the drug-resistant C. albicans. After the combinational treatment, we detected the disruption of cell membrane integrity, the tendency of PVP-coated Ag-NPs to adhere to cell membrane, and the inhibition of budding process. Moreover, after the combinational treatment, the defects in ergosterol signaling and efflux pump functions were detected. Our results suggest that the combinational use of engineered nanomaterials (ENMs), such as PVP-coated Ag-NPs, with the conventional antifungal may be a viable strategy to combat drug-resistant fungal infection. PMID:27455637

  5. Factors influencing the magnitude and clinical significance of drug interactions between azole antifungals and select immunosuppressants.

    PubMed

    Saad, Aline H; DePestel, Daryl D; Carver, Peggy L

    2006-12-01

    The magnitude of drug interactions between azole antifungals and immunosuppressants is drug and patient specific and depends on the potency of the azole inhibitor involved, the resulting plasma concentrations of each drug, the drug formulation, and interpatient variability. Many factors contribute to variability in the magnitude and clinical significance of drug interactions between an immunosuppressant such as cyclosporine, tacrolimus, or sirolimus and an antifungal agent such as ketoconazole, fluconazole, itraconazole, voriconazole, or posaconazole. By bringing similarities and differences among these agents and their potential interactions to clinicians' attention, they can appreciate and apply these findings in a individualized patient approach rather than follow only the one-size-fits-all dosing recommendations suggested in many tertiary references. Differences in metabolism and in the inhibitory potency of cytochrome P450 3A4 and P-glycoprotein influence the onset, magnitude, and resolution of drug interactions and their potential effect on clinical outcomes. Important issues are the route of administration and the decision to preemptively adjust dosages versus intensive monitoring with subsequent dosage adjustments. We provide recommendations for the concomitant use of these agents, including suggestions regarding contraindicated combinations, those best avoided, and those requiring close monitoring of drug dosages and plasma concentrations. PMID:17125435

  6. Transcription Factor ADS-4 Regulates Adaptive Responses and Resistance to Antifungal Azole Stress

    PubMed Central

    Wang, Kangji; Zhang, Zhenying; Chen, Xi; Sun, Xianyun; Jin, Cheng

    2015-01-01

    Azoles are commonly used as antifungal drugs or pesticides to control fungal infections in medicine and agriculture. Fungi adapt to azole stress by rapidly activating the transcription of a number of genes, and transcriptional increases in some azole-responsive genes can elevate azole resistance. The regulatory mechanisms that control transcriptional responses to azole stress in filamentous fungi are not well understood. This study identified a bZIP transcription factor, ADS-4 (antifungal drug sensitive-4), as a new regulator of adaptive responses and resistance to antifungal azoles. Transcription of ads-4 in Neurospora crassa cells increased when they were subjected to ketoconazole treatment, whereas the deletion of ads-4 resulted in hypersensitivity to ketoconazole and fluconazole. In contrast, the overexpression of ads-4 increased resistance to fluconazole and ketoconazole in N. crassa. Transcriptome sequencing (RNA-seq) analysis, followed by quantitative reverse transcription (qRT)-PCR confirmation, showed that ADS-4 positively regulated the transcriptional responses of at least six genes to ketoconazole stress in N. crassa. The gene products of four ADS-4-regulated genes are known contributors to azole resistance, including the major efflux pump CDR4 (Pdr5p ortholog), an ABC multidrug transporter (NcAbcB), sterol C-22 desaturase (ERG5), and a lipid transporter (NcRTA2) that is involved in calcineurin-mediated azole resistance. Deletion of the ads-4-homologous gene Afads-4 in Aspergillus fumigatus caused hypersensitivity to itraconazole and ketoconazole, which suggested that ADS-4 is a functionally conserved regulator of adaptive responses to azoles. This study provides important information on a new azole resistance factor that could be targeted by a new range of antifungal pesticides and drugs. PMID:26100701

  7. Cinnamaldehyde and its derivatives, a novel class of antifungal agents.

    PubMed

    Shreaz, Sheikh; Wani, Waseem A; Behbehani, Jawad M; Raja, Vaseem; Irshad, Md; Karched, Maribasappa; Ali, Intzar; Siddiqi, Weqar A; Hun, Lee Ting

    2016-07-01

    The last few decades have seen an alarming rise in fungal infections, which currently represent a global health threat. Despite extensive research towards the development of new antifungal agents, only a limited number of antifungal drugs are available in the market. The routinely used polyene agents and many azole antifungals are associated with some common side effects such as severe hepatotoxicity and nephrotoxicity. Also, antifungal resistance continues to grow and evolve and complicate patient management, despite the introduction of new antifungal agents. This suitation requires continuous attention. Cinnamaldehyde has been reported to inhibit bacteria, yeasts, and filamentous molds via the inhibition of ATPases, cell wall biosynthesis, and alteration of membrane structure and integrity. In this regard, several novel cinnamaldehyde derivatives were synthesized with the claim of potential antifungal activities. The present article describes antifungal properties of cinnamaldehyde and its derivatives against diverse classes of pathogenic fungi. This review will provide an overview of what is currently known about the primary mode of action of cinnamaldehyde. Synergistic approaches for boosting the effectiveness of cinnamaldehyde and its derivatives have been highlighted. Also, a keen analysis of the pharmacologically active systems derived from cinnamaldehyde has been discussed. Finally, efforts were made to outline the future perspectives of cinnamaldehyde-based antifungal agents. The purpose of this review is to provide an overview of current knowledge about the antifungal properties and antifungal mode of action of cinnamaldehyde and its derivatives and to identify research avenues that can facilitate implementation of cinnamaldehyde as a natural antifungal. PMID:27259370

  8. De-repression of CSP-1 activates adaptive responses to antifungal azoles

    PubMed Central

    Chen, Xi; Xue, Wei; Zhou, Jun; Zhang, Zhenying; Wei, Shiping; Liu, Xingyu; Sun, Xianyun; Wang, Wenzhao; Li, Shaojie

    2016-01-01

    Antifungal azoles are the major drugs that are used to treat fungal infections. This study found that in response to antifungal azole stress, Neurospora crassa could activate the transcriptional responses of many genes and increase azole resistance by reducing the level of conidial separation 1 (CSP-1), a global transcription repressor, at azole-responsive genes. The expression of csp-1 was directly activated by the transcription factors WC-1 and WC-2. Upon ketoconazole (KTC) stress, the transcript levels of wc-1 and wc-2 were not changed, but csp-1 transcription rapidly declined. A chromatin immunoprecipitation-quantitative polymerase chain reaction analysis revealed a rapid reduction in the WC-2 enrichment at the csp-1 promoter upon KTC treatment, which might be responsible for the KTC-induced csp-1 downregulation. Deletion of csp-1 increased resistance to KTC and voriconazole, while csp-1 overexpression increased KTC susceptibility. CSP-1 transcriptionally repressed a number of azole-responsive genes, including genes encoding the azole target ERG11, the azole efflux pump CDR4, and the sterol C-22 desaturase ERG5. Deletion of csp-1 also reduced the KTC-induced accumulation of ergosterol intermediates, eburicol, and 14α-methyl-3,6-diol. CSP-1 orthologs are widely present in filamentous fungi, and an Aspergillus fumigatus mutant in which the csp-1 was deleted was resistant to itraconazole. PMID:26781458

  9. Genesis of Azole Antifungal Resistance from Agriculture to Clinical Settings.

    PubMed

    Azevedo, Maria-Manuel; Faria-Ramos, Isabel; Cruz, Luísa Costa; Pina-Vaz, Cidália; Rodrigues, Acácio Gonçalves

    2015-09-01

    Azole fungal resistance is becoming a major public health problem in medicine in recent years. However, it was known in agriculture since several decades; the extensive use of these compounds results in contamination of air, plants, and soil. The increasing frequency of life-threatening fungal infections and the increase of prophylactical use of azoles in high-risk patients, taken together with the evolutionary biology evidence that drug selection pressure is an important factor for the emergence and spread of drug resistance, can result in a dramatic scenario. This study reviews the azole use in agricultural and medical contexts and discusses the hypothetical link between its extensive use and the emergence of azole resistance among human fungal pathogens. PMID:26289797

  10. Azole Antifungal Agents To Treat the Human Pathogens Acanthamoeba castellanii and Acanthamoeba polyphaga through Inhibition of Sterol 14α-Demethylase (CYP51)

    PubMed Central

    Lamb, David C.; Warrilow, Andrew G. S.; Rolley, Nicola J.; Parker, Josie E.; Nes, W. David; Smith, Stephen N.; Kelly, Diane E.

    2015-01-01

    In this study, we investigate the amebicidal activities of the pharmaceutical triazole CYP51 inhibitors fluconazole, itraconazole, and voriconazole against Acanthamoeba castellanii and Acanthamoeba polyphaga and assess their potential as therapeutic agents against Acanthamoeba infections in humans. Amebicidal activities of the triazoles were assessed by in vitro minimum inhibition concentration (MIC) determinations using trophozoites of A. castellanii and A. polyphaga. In addition, triazole effectiveness was assessed by ligand binding studies and inhibition of CYP51 activity of purified A. castellanii CYP51 (AcCYP51) that was heterologously expressed in Escherichia coli. Itraconazole and voriconazole bound tightly to AcCYP51 (dissociation constant [Kd] of 10 and 13 nM), whereas fluconazole bound weakly (Kd of 2,137 nM). Both itraconazole and voriconazole were confirmed to be strong inhibitors of AcCYP51 activity (50% inhibitory concentrations [IC50] of 0.23 and 0.39 μM), whereas inhibition by fluconazole was weak (IC50, 30 μM). However, itraconazole was 8- to 16-fold less effective (MIC, 16 mg/liter) at inhibiting A. polyphaga and A. castellanii cell proliferation than voriconazole (MIC, 1 to 2 mg/liter), while fluconazole did not inhibit Acanthamoeba cell division (MIC, >64 mg/liter) in vitro. Voriconazole was an effective inhibitor of trophozoite proliferation for A. castellanii and A. polyphaga; therefore, it should be evaluated in trials versus itraconazole for controlling Acanthamoeba infections. PMID:26014948

  11. Azole Antifungal Agents To Treat the Human Pathogens Acanthamoeba castellanii and Acanthamoeba polyphaga through Inhibition of Sterol 14α-Demethylase (CYP51).

    PubMed

    Lamb, David C; Warrilow, Andrew G S; Rolley, Nicola J; Parker, Josie E; Nes, W David; Smith, Stephen N; Kelly, Diane E; Kelly, Steven L

    2015-08-01

    In this study, we investigate the amebicidal activities of the pharmaceutical triazole CYP51 inhibitors fluconazole, itraconazole, and voriconazole against Acanthamoeba castellanii and Acanthamoeba polyphaga and assess their potential as therapeutic agents against Acanthamoeba infections in humans. Amebicidal activities of the triazoles were assessed by in vitro minimum inhibition concentration (MIC) determinations using trophozoites of A. castellanii and A. polyphaga. In addition, triazole effectiveness was assessed by ligand binding studies and inhibition of CYP51 activity of purified A. castellanii CYP51 (AcCYP51) that was heterologously expressed in Escherichia coli. Itraconazole and voriconazole bound tightly to AcCYP51 (dissociation constant [Kd] of 10 and 13 nM), whereas fluconazole bound weakly (Kd of 2,137 nM). Both itraconazole and voriconazole were confirmed to be strong inhibitors of AcCYP51 activity (50% inhibitory concentrations [IC50] of 0.23 and 0.39 μM), whereas inhibition by fluconazole was weak (IC50, 30 μM). However, itraconazole was 8- to 16-fold less effective (MIC, 16 mg/liter) at inhibiting A. polyphaga and A. castellanii cell proliferation than voriconazole (MIC, 1 to 2 mg/liter), while fluconazole did not inhibit Acanthamoeba cell division (MIC, >64 mg/liter) in vitro. Voriconazole was an effective inhibitor of trophozoite proliferation for A. castellanii and A. polyphaga; therefore, it should be evaluated in trials versus itraconazole for controlling Acanthamoeba infections. PMID:26014948

  12. Role of antifungal agents in the treatment of seborrheic dermatitis.

    PubMed

    Gupta, Aditya K; Nicol, Karyn; Batra, Roma

    2004-01-01

    Seborrheic dermatitis is a superficial fungal disease of the skin, occurring in areas rich in sebaceous glands. It is thought that an association exists between Malassezia yeasts and seborrheic dermatitis. This may, in part, be due to an abnormal or inflammatory immune response to these yeasts. The azoles represent the largest class of antifungals used in the treatment of this disease to date. In addition to their antifungal properties, some azoles, including bifonazole, itraconazole, and ketoconazole, have demonstrated anti-inflammatory activity, which may be beneficial in alleviating symptoms. Other topical antifungal agents, such as the allylamines (terbinafine), benzylamines (butenafine), hydroxypyridones (ciclopirox), and immunomodulators (pimecrolimus and tacrolimus), have also been effective. In addition, recent studies have revealed that tea tree oil (Melaleuca oil), honey, and cinnamic acid have antifungal activity against Malassezia species, which may be of benefit in the treatment of seborrheic dermatitis. In cases where seborrheic dermatitis is widespread, the use of an oral therapy, such as ketoconazole, itraconazole, and terbinafine, may be preferred. Essentially, antifungal therapy reduces the number of yeasts on the skin, leading to an improvement in seborrheic dermatitis. With a wide availability of preparations, including creams, shampoos, and oral formulations, antifungal agents are safe and effective in the treatment of seborrheic dermatitis. PMID:15663338

  13. Tissue Penetration of Antifungal Agents

    PubMed Central

    Felton, Timothy; Troke, Peter F.

    2014-01-01

    SUMMARY Understanding the tissue penetration of systemically administered antifungal agents is critical for a proper appreciation of their antifungal efficacy in animals and humans. Both the time course of an antifungal drug and its absolute concentrations within tissues may differ significantly from those observed in the bloodstream. In addition, tissue concentrations must also be interpreted within the context of the pathogenesis of the various invasive fungal infections, which differ significantly. There are major technical obstacles to the estimation of concentrations of antifungal agents in various tissue subcompartments, yet these agents, even those within the same class, may exhibit markedly different tissue distributions. This review explores these issues and provides a summary of tissue concentrations of 11 currently licensed systemic antifungal agents. It also explores the therapeutic implications of their distribution at various sites of infection. PMID:24396137

  14. Voriconazole: a new triazole antifungal agent.

    PubMed

    Johnson, Leonard B; Kauffman, Carol A

    2003-03-01

    Voriconazole is a second-generation azole antifungal agent that shows excellent in vitro activity against a wide variety of yeasts and molds. It can be given by either the intravenous or the oral route; the oral formulation has excellent bioavailability. The side effect profile of voriconazole is unique in that non-sight-threatening, transient visual disturbances occur in approximately 30% of patients given the drug. Rash (which can manifest as photosensitivity) and hepatitis also occur. The potential for drug-drug interactions is high and requires that careful attention be given to dosage regimens and monitoring of serum levels and effects of interacting drugs. Voriconazole has been approved for the treatment of invasive aspergillosis and refractory infections with Pseudallescheria/Scedosporium and Fusarium species, and it will likely become the drug of choice for treatment of serious infections with those filamentous fungi. PMID:12594645

  15. Trafficking through the late endosome significantly impacts Candida albicans tolerance of the azole antifungals.

    PubMed

    Luna-Tapia, Arturo; Kerns, Morgan E; Eberle, Karen E; Jursic, Branko S; Palmer, Glen E

    2015-04-01

    The azole antifungals block ergosterol biosynthesis by inhibiting lanosterol demethylase (Erg11p). The resulting depletion of cellular ergosterol and the accumulation of "toxic" sterol intermediates are both thought to compromise plasma membrane function. However, the effects of ergosterol depletion upon the function of intracellular membranes and organelles are not well described. The purpose of this study was to characterize the effects of azole treatment upon the integrity of the Candida albicans vacuole and to determine whether, in turn, vacuolar trafficking influences azole susceptibility. Profound fragmentation of the C. albicans vacuole can be observed as an early consequence of azole treatment, and it precedes significant growth inhibition. In addition, a C. albicans vps21Δ/Δ mutant, blocked in membrane trafficking through the late endosomal prevacuolar compartment (PVC), is able to grow significantly more than the wild type in the presence of several azole antifungals under standard susceptibility testing conditions. Furthermore, the vps21Δ/Δ mutant is able to grow despite the depletion of cellular ergosterol. This phenotype resembles an exaggerated form of "trailing growth" that has been described for some clinical isolates. In contrast, the vps21Δ/Δ mutant is hypersensitive to drugs that block alternate steps in ergosterol biosynthesis. On the basis of these results, we propose that endosomal trafficking defects may lead to the cellular "redistribution" of the sterol intermediates that accumulate following inhibition of ergosterol biosynthesis. Furthermore, the destination of these intermediates, or the precise cellular compartments in which they accumulate, may be an important determinant of their toxicity and thus ultimately antifungal efficacy. PMID:25666149

  16. Trafficking through the Late Endosome Significantly Impacts Candida albicans Tolerance of the Azole Antifungals

    PubMed Central

    Luna-Tapia, Arturo; Kerns, Morgan E.; Eberle, Karen E.; Jursic, Branko S.

    2015-01-01

    The azole antifungals block ergosterol biosynthesis by inhibiting lanosterol demethylase (Erg11p). The resulting depletion of cellular ergosterol and the accumulation of “toxic” sterol intermediates are both thought to compromise plasma membrane function. However, the effects of ergosterol depletion upon the function of intracellular membranes and organelles are not well described. The purpose of this study was to characterize the effects of azole treatment upon the integrity of the Candida albicans vacuole and to determine whether, in turn, vacuolar trafficking influences azole susceptibility. Profound fragmentation of the C. albicans vacuole can be observed as an early consequence of azole treatment, and it precedes significant growth inhibition. In addition, a C. albicans vps21Δ/Δ mutant, blocked in membrane trafficking through the late endosomal prevacuolar compartment (PVC), is able to grow significantly more than the wild type in the presence of several azole antifungals under standard susceptibility testing conditions. Furthermore, the vps21Δ/Δ mutant is able to grow despite the depletion of cellular ergosterol. This phenotype resembles an exaggerated form of “trailing growth” that has been described for some clinical isolates. In contrast, the vps21Δ/Δ mutant is hypersensitive to drugs that block alternate steps in ergosterol biosynthesis. On the basis of these results, we propose that endosomal trafficking defects may lead to the cellular “redistribution” of the sterol intermediates that accumulate following inhibition of ergosterol biosynthesis. Furthermore, the destination of these intermediates, or the precise cellular compartments in which they accumulate, may be an important determinant of their toxicity and thus ultimately antifungal efficacy. PMID:25666149

  17. In Vitro Activity of the Antifungal Azoles Itraconazole and Posaconazole against Leishmania amazonensis

    PubMed Central

    de Macedo-Silva, Sara Teixeira; Urbina, Julio A.; de Souza, Wanderley; Rodrigues, Juliany Cola Fernandes

    2013-01-01

    Leishmaniasis, caused by protozoan parasites of the Leishmania genus, is one of the most prevalent neglected tropical diseases. It is endemic in 98 countries, causing considerable morbidity and mortality. Pentavalent antimonials are the first line of treatment for leishmaniasis except in India. In resistant cases, miltefosine, amphotericin B and pentamidine are used. These treatments are unsatisfactory due to toxicity, limited efficacy, high cost and difficult administration. Thus, there is an urgent need to develop drugs that are efficacious, safe, and more accessible to patients. Trypanosomatids, including Leishmania spp. and Trypanosoma cruzi, have an essential requirement for ergosterol and other 24-alkyl sterols, which are absent in mammalian cells. Inhibition of ergosterol biosynthesis is increasingly recognized as a promising target for the development of new chemotherapeutic agents. The aim of this work was to investigate the antiproliferative, physiological and ultrastructural effects against Leishmania amazonensis of itraconazole (ITZ) and posaconazole (POSA), two azole antifungal agents that inhibit sterol C14α-demethylase (CYP51). Antiproliferative studies demonstrated potent activity of POSA and ITZ: for promastigotes, the IC50 values were 2.74 µM and 0.44 µM for POSA and ITZ, respectively, and for intracellular amastigotes, the corresponding values were 1.63 µM and 0.08 µM, for both stages after 72 h of treatment. Physiological studies revealed that both inhibitors induced a collapse of the mitochondrial membrane potential (ΔΨm), which was consistent with ultrastructural alterations in the mitochondrion. Intense mitochondrial swelling, disorganization and rupture of mitochondrial membranes were observed by transmission electron microscopy. In addition, accumulation of lipid bodies, appearance of autophagosome-like structures and alterations in the kinetoplast were also observed. In conclusion, our results indicate that ITZ and POSA are potent

  18. Haloprogin: a Topical Antifungal Agent

    PubMed Central

    Harrison, E. F.; Zwadyk, P.; Bequette, R. J.; Hamlow, E. E.; Tavormina, P. A.; Zygmunt, W. A.

    1970-01-01

    Haloprogin was shown to be a highly effective agent for the treatment of experimentally induced topical mycotic infections in guinea pigs. Its in vitro spectrum of activity also includes yeasts, yeastlike fungi (Candida species), and certain gram-positive bacteria. The in vitro and in vivo antifungal activity of haloprogin against dermatophytes was equal to that observed with tolnaftate. The striking differences between the two agents were the marked antimonilial and selective antibacterial activities shown by haloprogin, contrasted with the negligible activities found with tolnaftate. Addition of serum decreased the in vitro antifungal activity of haloprogin to a greater extent than that of tolnaftate; however, diminished antifungal activity was not observed when haloprogin was applied topically to experimental dermatophytic infections. Based on its broad spectrum of antimicrobial activity, haloprogin may prove to be a superior topical agent in the treatment of dermatophytic and monilial infections in man. PMID:5422306

  19. Effect of Nitric Oxide on the Antifungal Activity of Oxidative Stress and Azoles Against Candida albicans.

    PubMed

    Li, De-Dong; Yang, Chang-Chun; Liu, Ping; Wang, Yan; Sun, Yan

    2016-06-01

    Nitric oxide (NO) is a small molecule with a wide range of biological activities in mammalian and bacteria. However, the role of NO in fungi, especially Candida albicans, is not clear. In this study, we confirmed the generation of endogenous NO in C. albicans, and found that the production of endogenous NO in C. albicans was associated with nitric oxide synthase pathway. Our results further indicated that the production of endogenous NO in C. albicans was reduced under oxidative stress such as menadione or H2O2 treatment. Meanwhile, exogenous NO donor, sodium nitroprusside (SNP), synergized with H2O2 against C. albicans. Interestingly, SNP could inhibit the antifungal effect of azoles against C. albicans in vitro, suggesting that NO might be involved in the resistance of C. albicans to antifungals. Collectively, this study demonstrated the production of endogenous NO in C. albicans, and indicated that NO may play an important role in the response of C. albicans to oxidative stress and azoles. PMID:27570314

  20. Azole Resistance in Aspergillus fumigatus: Can We Retain the Clinical Use of Mold-Active Antifungal Azoles?

    PubMed Central

    Verweij, Paul E.; Chowdhary, Anuradha; Melchers, Willem J. G.; Meis, Jacques F.

    2016-01-01

    Azole resistance in Aspergillus fumigatus has emerged as a global health problem. Although the number of cases of azole-resistant aspergillosis is still limited, resistance mechanisms continue to emerge, thereby threatening the role of the azole class in the management of diseases caused by Aspergillus. The majority of cases of azole-resistant disease are due to resistant A. fumigatus originating from the environment. Patient management is difficult due to the absence of patient risk factors, delayed diagnosis, and limited treatment options, resulting in poor treatment outcome. International and collaborative efforts are required to understand how resistance develops in the environment to allow effective measures to be implemented aimed at retaining the use of azoles both for food production and human medicine. PMID:26486705

  1. Chalcone derivatives as potential antifungal agents: Synthesis, and antifungal activity.

    PubMed

    Gupta, Deepa; Jain, D K

    2015-01-01

    Much research has been carried out with the aim to discover the therapeutic values of chalcone derivatives. Chalcones possess wide range of pharmacological activity such as antibacterial, antimalarial, antiprotozoal, antitubercular, anticancer, and antifungal agents etc. The presence of reactive α,β-unsaturated keto group in chalcones is found to be responsible for their biological activity. The rapid developments of resistance to antifungal agents, led to design, and synthesize the new antifungal agents. The derivatives of chalcones were prepared using Claisen-Schmidt condensation scheme with appropriate tetralone and aldehyde derivatives. Ten derivatives were synthesized and were biologically screened for antifungal activity. The newly synthesized derivatives of chalcone showed antifungal activity against fungal species, Microsporum gypseum. The results so obtained were superior or comparable to ketoconazole. It was observed that none of the compounds tested showed positive results for fungi Candida albicans nor against fungi Aspergillus niger. Chalcone derivatives showed inhibitory effect against M. gypseum species of fungus. It was found that among the chalcone derivatives so synthesized, two of them, that is, 4-chloro derivative, and unsubstituted derivative of chalcone showed antifungal activity superior to ketoconazole. Thus, these can be the potential new molecule as antifungal agent. PMID:26317075

  2. Reduced susceptibility of Candida albicans clinical isolates to azoles and detection of mutations in the ERG11 gene.

    PubMed

    Zhang, Lei; Yang, Hai-Fei; Liu, Yan-Yan; Xu, Xi-Hai; Ye, Ying; Li, Jia-Bin

    2013-12-01

    We investigated the susceptibility of Candida albicans isolated from clinic specimens to azole antifungal agents and estimated the association of the ERG11 mutations with azole resistance during recent 5years in China. In this study, novel mutations G346A, A434V, and L480F in ERG11 may be related to azole resistance in C. albicans. PMID:24070847

  3. Azole Antifungal Sensitivity of Sterol 14α-Demethylase (CYP51) and CYP5218 from Malassezia globosa.

    PubMed

    Warrilow, Andrew G S; Price, Claire L; Parker, Josie E; Rolley, Nicola J; Smyrniotis, Christopher J; Hughes, David D; Thoss, Vera; Nes, W David; Kelly, Diane E; Holman, Theodore R; Kelly, Steven L

    2016-01-01

    Malassezia globosa cytochromes P450 CYP51 and CYP5218 are sterol 14α-demethylase (the target of azole antifungals) and a putative fatty acid metabolism protein (and a potential azole drug target), respectively. Lanosterol, eburicol and obtusifoliol bound to CYP51 with Kd values of 32, 23 and 28 μM, respectively, catalyzing sterol 14α-demethylation with respective turnover numbers of 1.7 min(-1), 5.6 min(-1) and 3.4 min(-1). CYP5218 bound a range of fatty acids with linoleic acid binding strongest (Kd 36 μM), although no metabolism could be detected in reconstitution assays or role in growth on lipids. Clotrimazole, fluconazole, itraconazole, ketoconazole, voriconazole and ketaminazole bound tightly to CYP51 (Kd ≤ 2 to 11 nM). In contrast, fluconazole did not bind to CYP5218, voriconazole and ketaminazole bound weakly (Kd ~107 and ~12 μM), whereas ketoconazole, clotrimazole and itraconazole bound strongest to CYP5218 (Kd ~1.6, 0.5 and 0.4 μM) indicating CYP5218 to be only a secondary target of azole antifungals. IC50 determinations confirmed M. globosa CYP51 was strongly inhibited by azole antifungals (0.15 to 0.35 μM). MIC100 studies showed itraconazole should be considered as an alternative to ketoconazole given the potency and safety profiles and the CYP51 assay system can be used in structure-activity studies in drug development. PMID:27291783

  4. Azole Antifungal Sensitivity of Sterol 14α-Demethylase (CYP51) and CYP5218 from Malassezia globosa

    PubMed Central

    Warrilow, Andrew G. S.; Price, Claire L.; Parker, Josie E.; Rolley, Nicola J.; Smyrniotis, Christopher J.; Hughes, David D.; Thoss, Vera; Nes, W. David; Kelly, Diane E.; Holman, Theodore R.; Kelly, Steven L.

    2016-01-01

    Malassezia globosa cytochromes P450 CYP51 and CYP5218 are sterol 14α-demethylase (the target of azole antifungals) and a putative fatty acid metabolism protein (and a potential azole drug target), respectively. Lanosterol, eburicol and obtusifoliol bound to CYP51 with Kd values of 32, 23 and 28 μM, respectively, catalyzing sterol 14α-demethylation with respective turnover numbers of 1.7 min−1, 5.6 min−1 and 3.4 min−1. CYP5218 bound a range of fatty acids with linoleic acid binding strongest (Kd 36 μM), although no metabolism could be detected in reconstitution assays or role in growth on lipids. Clotrimazole, fluconazole, itraconazole, ketoconazole, voriconazole and ketaminazole bound tightly to CYP51 (Kd ≤ 2 to 11 nM). In contrast, fluconazole did not bind to CYP5218, voriconazole and ketaminazole bound weakly (Kd ~107 and ~12 μM), whereas ketoconazole, clotrimazole and itraconazole bound strongest to CYP5218 (Kd ~1.6, 0.5 and 0.4 μM) indicating CYP5218 to be only a secondary target of azole antifungals. IC50 determinations confirmed M. globosa CYP51 was strongly inhibited by azole antifungals (0.15 to 0.35 μM). MIC100 studies showed itraconazole should be considered as an alternative to ketoconazole given the potency and safety profiles and the CYP51 assay system can be used in structure-activity studies in drug development. PMID:27291783

  5. Azole antifungal inhibition of buprenorphine, methadone and oxycodone in vitro metabolism.

    PubMed

    Moody, David E; Liu, Fenyun; Fang, Wenfang B

    2015-06-01

    Opioid-related mortality rates have escalated. Drug interactions may increase blood concentrations of the opioid. We therefore used human liver microsomes (HLMs) and cDNA-expressed human cytochrome P450s (rCYPs) to study in vitro inhibition of buprenorphine metabolism to norbuprenorphine (CYP3A4 and 2C8), oxycodone metabolism to noroxycodone (CYP3A4 and 2C18) and oxymorphone (CYP2D6), and methadone metabolism to R- and S-2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP; CYP3A4 and 2B6). In this study, we have examined the inhibitory effect of 12 (mostly antifungal) azoles. These compounds have a wide range of solubility; to keep organic solvent ≤1%, there was an equally wide range of highest concentration tested (e.g., itraconazole 5 µM to fluconazole 1000 µM). Inhibitors were first incubated with HLMs at three concentrations with or without preincubation of inhibitor with reducing equivalents to also screen for time-dependent inhibition (TDI). Posaconazole displayed evidence of TDI; metronidazole and albendazole had no significant effect. Azoles were next screened at the highest achievable concentration for non-CYP3A4 pathways. IC50 values (µM) were determined for most CYP3A4 pathways (ranges) and other pathways as dictated by screen results: clotrimazole (0.30 - 0.35; others >30 µM); econazole (2.2 - 4.9; 2B6 R-EDDP - 9.5, S-EDDP - 6.8; 2C8 - 6.0; 2C18 - 1.0; 2D6 - 1.2); fluconazole (7.7 - 66; 2B6 - 313, 361; 2C8 - 1240; 2C18 - 17; 2D6 - 1000); itraconazole (2.5 to >5; others >5); ketoconazole (0.032 - 0.094; 2B6 - 12, 31; 2C8 - 78; 2C18 - 0.98; 2D6 - 182); miconazole (2.3 - 7.6; 2B6 - 2.8, 2.8; 2C8 - 5.3; 2C18 - 3.1; 2D6 - 5.9); posaconazole (3.4 - 20; 2C18 - 3.8; others >30); terconazole (0.48 to >10; 2C18 - 8.1; others >10) and voriconazole (0.40 - 15; 2B6 - 2.4, 2.5; 2C8 - 170; 2C18 - 13; 2D6 >300). Modeling based on estimated Ki values and plasma concentrations from the literature suggest that the orally administered azoles, particularly

  6. Antifungal agents for onychomycosis: new treatment strategies to improve safety.

    PubMed

    Zane, Lee T; Chanda, Sanjay; Coronado, Dina; Del Rosso, James

    2016-01-01

    Onychomycosis is a common and difficult-to-treat fungal infection of the nail unit that gradually leads to dystrophic changes of the nail plate and nail bed. If untreated, infection progresses and may lead to discomfort, reduced quality of life, and risk of complications in patients with comorbid conditions (eg, diabetes, human immunodeficiency virus, peripheral vascular disease). Onychomycosis treatments are designed to eradicate causative pathogens (most commonly Trichophyton rubrum and Trichophyton mentagrophytes), restore healthy nails, and prevent recurrence or spread of infection. Given the deep-seated nature of most cases of onychomycosis, an effective antifungal agent needs to achieve and maintain sufficient drug concentrations throughout the nail unit for the duration of healthy nail in-growth. Oral antifungal drugs are the most effective available therapy and are generally well tolerated, but may be limited by safety concerns and the potential for drug-drug interactions (DDIs). Thus, treating physicians and pharmacists must be cognizant of a patient's current medications; indeed, it may not be feasible to treat onychomycosis in patients with diabetes, heart disease, or depression because of the risk for DDIs. Current topical therapy is not associated with risk of DDIs. Tavaborole and efinaconazole, two recently approved topical agents, have demonstrated good nail penetration and high negative culture rates in clinical trials of patients with onychomycosis. This article provides the treating physician and pharmacist with information on the safety and effectiveness of current oral (allylamine, azole) and topical (ciclopirox, efinaconazole, tavaborole) treatment to aid in making informed treatment decisions based on the unique characteristics (medication history, comorbidities, nature of onychomycosis) of each patient. PMID:27136621

  7. Multidrug Transporters and Alterations in Sterol Biosynthesis Contribute to Azole Antifungal Resistance in Candida parapsilosis.

    PubMed

    Berkow, Elizabeth L; Manigaba, Kayihura; Parker, Josie E; Barker, Katherine S; Kelly, Stephen L; Rogers, P David

    2015-10-01

    While much is known concerning azole resistance in Candida albicans, considerably less is understood about Candida parapsilosis, an emerging species of Candida with clinical relevance. We conducted a comprehensive analysis of azole resistance in a collection of resistant C. parapsilosis clinical isolates in order to determine which genes might play a role in this process within this species. We examined the relative expression of the putative drug transporter genes CDR1 and MDR1 and that of ERG11. In isolates overexpressing these genes, we sequenced the genes encoding their presumed transcriptional regulators, TAC1, MRR1, and UPC2, respectively. We also sequenced the sterol biosynthesis genes ERG3 and ERG11 in these isolates to find mutations that might contribute to this phenotype in this Candida species. Our findings demonstrate that the putative drug transporters Cdr1 and Mdr1 contribute directly to azole resistance and suggest that their overexpression is due to activating mutations in the genes encoding their transcriptional regulators. We also observed that the Y132F substitution in ERG11 is the only substitution occurring exclusively among azole-resistant isolates, and we correlated this with specific changes in sterol biosynthesis. Finally, sterol analysis of these isolates suggests that other changes in sterol biosynthesis may contribute to azole resistance in C. parapsilosis. PMID:26169412

  8. Multidrug Transporters and Alterations in Sterol Biosynthesis Contribute to Azole Antifungal Resistance in Candida parapsilosis

    PubMed Central

    Berkow, Elizabeth L.; Manigaba, Kayihura; Parker, Josie E.; Barker, Katherine S.; Kelly, Stephen L.

    2015-01-01

    While much is known concerning azole resistance in Candida albicans, considerably less is understood about Candida parapsilosis, an emerging species of Candida with clinical relevance. We conducted a comprehensive analysis of azole resistance in a collection of resistant C. parapsilosis clinical isolates in order to determine which genes might play a role in this process within this species. We examined the relative expression of the putative drug transporter genes CDR1 and MDR1 and that of ERG11. In isolates overexpressing these genes, we sequenced the genes encoding their presumed transcriptional regulators, TAC1, MRR1, and UPC2, respectively. We also sequenced the sterol biosynthesis genes ERG3 and ERG11 in these isolates to find mutations that might contribute to this phenotype in this Candida species. Our findings demonstrate that the putative drug transporters Cdr1 and Mdr1 contribute directly to azole resistance and suggest that their overexpression is due to activating mutations in the genes encoding their transcriptional regulators. We also observed that the Y132F substitution in ERG11 is the only substitution occurring exclusively among azole-resistant isolates, and we correlated this with specific changes in sterol biosynthesis. Finally, sterol analysis of these isolates suggests that other changes in sterol biosynthesis may contribute to azole resistance in C. parapsilosis. PMID:26169412

  9. [New antifungal agents: voriconazole and caspofungin].

    PubMed

    Dupont, B

    2003-12-01

    Among new available antifungal agents voriconazole is a new triazole with an intravenous (i.v.) and oral formulation, and caspofungin is an echinocandin, new family with a new mode of action on the cell wall. It is available as an i.v. preparation. Both drugs have a broad spectrum targeting most of the usual pathogens: Candida and Aspergillus, even with low suceptibility or resistance to other antifungals. Voriconazole is also active on Scedosporium and Fusarium. The efficacy of these molecules was established in vitro and in experimental infections in animals either normal or immunosuppressed. Voriconazole is active in oropharyngeal and esophageal candidiasis, in refractory invasive candidiasis and as a first line treatment of invasive aspergillosis with better results than amphotéricine B. It was also effective in scedosporiosis and in fusariosis. Caspofungin is active in oropharyngeal and esophageal candidiasis, in invasive candidiasis ranking among the best drugs in non neutropenic patients. It was shown effective in refractory aspergillosis. As empirical treatment of febrile neutropenic patients, these molecules should probably be restricted to the highest risk-population. Safety is good, side effects are a rare cause of discontinuation of treatment, class specific drug-drug interactions occur with voriconazole. These molecules open an important field of investigations with combination of antifungal agents. PMID:15022787

  10. Antifungal activity of ketoconazole and other azoles against Malassezia furfur in vitro and in vivo.

    PubMed

    Strippoli, V; Piacentini, A; D'Auria, F D; Simonetti, N

    1997-01-01

    The in vitro activity of several antifungal agents (ketoconazole, miconazole, econazole, fenticonazole, itraconazole, fluconazole) in routine clinical use against Malassezia furfur infections has been studied with freshly isolated strains of M. furfur from pityriasis versicolor lesions. The results indicate that the drugs tested exert a good activity, and both ketoconazole and itraconazole appear very active (0.8 mg/l respectively). Hair samples from the beards of volunteer patients affected by pityriasis versicolor but otherwise healthy were examined to determine ketoconazole levels during oral therapy (one or two 200 mg tablets daily). It was shown that the drug progressively accumulates in the beard, reaching levels proportional to the dose administered, although blood levels did not increase in parallel. The study of drug concentration profile has evidenced a long ketoconazole persistence in the beard at therapeutic levels. In conclusion, the possibility of reaching high and lasting ketoconazole levels in the keratin layer of the epidermis indicates that systemic ketoconazole therapy could be useful for eradication of M. furfur in patients affected by pityriasis versicolor. PMID:9334866

  11. Antifungal therapy with an emphasis on biofilms

    PubMed Central

    Pierce, Christopher G.; Srinivasan, Anand; Uppuluri, Priya; Ramasubramanian, Anand K.; López-Ribot, José Luis

    2013-01-01

    Fungal infections are on the rise as advances in modern medicine prolong the lives of severely ill patients. Fungi are eukaryotic organisms and there are a limited number of targets for antifungal drug development; as a result the antifungal arsenal is exceedingly limited. Azoles, polyenes and echinocandins, constitute the mainstay of antifungal therapy for patients with life-threatening mycoses. One of the main factors complicating antifungal therapy is the formation of fungal biofilms, microbial communities displaying resistance to most antifungal agents. A better understanding of fungal biofilms provides for new opportunities for the development of urgently needed novel antifungal agents and strategies. PMID:24011516

  12. Synthesis and characterization of azolate gold(I) phosphane complexes as thioredoxin reductase inhibiting antitumor agents.

    PubMed

    Galassi, Rossana; Burini, Alfredo; Ricci, Simone; Pellei, Maura; Rigobello, Maria Pia; Citta, Anna; Dolmella, Alessandro; Gandin, Valentina; Marzano, Cristina

    2012-05-01

    Following an increasing interest in the gold drug therapy field, nine new neutral azolate gold(I) phosphane compounds have been synthesized and tested as anticancer agents. The azolate ligands used in this study are pyrazolates and imidazolates substituted with deactivating groups such as trifluoromethyl, nitro or chloride moieties, whereas the phosphane co-ligand is the triphenylphosphane or the more hydrophilic TPA (TPA = 1,3,5-triazaphosphaadamantane). The studied gold(I) complexes are: (3,5-bis-trifluoromethyl-1H-pyrazolate-1-yl)-triphenylphosphane-gold(I) (1), (3,5-dinitro-1H-pyrazolate-1-yl)-triphenylphosphane-gold(I) (2), (4-nitro-1H-pyrazolate-1-yl)-triphenylphosphane-gold(I) (5), (4,5-dichloro-1H-imidazolate-1-yl)-triphenylphosphane-gold(I) (7), with the related TPA complexes (3), (4), (6) and (8) and (1-benzyl-4,5-di-chloro-2H-imidazolate-2-yl)-triphenylphosphane-gold(I) (9). The presence of deactivating groups on the azole rings improves the solubility of these complexes in polar media. Compounds 1-8 contain the N-Au-P environment, whilst compound 9 is the only one to contain a C-Au-P environment. Crystal structures for compounds 1 and 2 have been obtained and discussed. Interestingly, the newly synthesized gold(I) compounds were found to possess a pronounced cytotoxic activity on several human cancer cells, some of which were endowed with cis-platin or multidrug resistance. In particular, among azolate gold(I) complexes, 1 and 2 proved to be the most promising derivatives eliciting an antiproliferative effect up to 70 times higher than cis-platin. Mechanistic experiments indicated that the inhibition of thioredoxin reductase (TrxR) might be involved in the pharmacodynamic behavior of these gold species. PMID:22391922

  13. Neutral red assay in minimum fungicidal concentrations of antifungal agents.

    PubMed

    Fukuda, T; Naka, W; Tajima, S; Nishikawa, T

    1996-01-01

    We assayed the fungicidal effects of antifungal agents using neutral red staining. Fungal elements of Trichophyton mentagrophytes and T. rubrum were treated with various concentrations of antifungal agents in 96-well filtration plates and then stained with neutral red. The amount of neutral red incorporated by the surviving viable cells was determined from the automated spectrophotometric readings at 550 nm. The minimum fungicidal concentrations (MFCs) of antifungal agents determined by this assay correlated well with those determined by conventional assay. This newly developed procedure should provide a rapid, reproducible, quantitative, qualitative and semi-automated susceptibility test for determination of the MFCs of the fungicidal agents. PMID:8912170

  14. Antagonistic interactions between azoles and amphotericin B with yeasts depend on azole lipophilia for special test conditions in vitro.

    PubMed Central

    Scheven, M; Schwegler, F

    1995-01-01

    The interactions of the azole antifungal agents fluconazole, itraconazole, ketoconazole, or miconazole with amphotericin B (AmB) in their effect on Candida albicans were investigated. These four azoles antagonized the fungistatic activity of AmB at sub-MICs if both substances acted simultaneously. This coincubation test was primarily developed to observe the azole-mediated demethylase inhibition quantitatively by bioassay. Interestingly, the occurrence of azole-AmB antagonism depended on azole lipophilia if specially selected test conditions were applied. By a consecutive incubation regimen, preincubation at high azole concentrations (1 to 50 micrograms/ml) and then subsequent incubation with AmB (1 microgram/ml), only preincubation with the three lipophilic azoles decreased the fungicidal activity of AmB but not that of FCZ. It was shown that yeasts absorb only lipophilic azoles to a remarkable extent. This fact might be responsible for the absence of antagonism of FCZ to AmB when yeasts were incubated consecutively. It can be concluded with caution that consecutive treatment of candidiasis with FCZ and AmB does not necessarily result in a clinically relevant antagonism. PMID:7486918

  15. Analysis of Current Antifungal Agents and Their Targets within the Pneumocystis carinii Genome

    PubMed Central

    Porollo, Aleksey; Meller, Jaroslaw; Joshi, Yogesh; Jaiswal, Vikash; Smulian, A. George; Cushion, Melanie T.

    2013-01-01

    Pneumocystis pneumonia (PCP) remains a leading opportunistic infection in patients with weakened immune system. The fungus causing the infection belongs to the genus, Pneumocystis, and its members are found in a large variety of mammals. Adaptation to the lung environment of a host with an intact immune system has been a key to its successful survival. Unfortunately, the metabolic strategies used by these fungi to grow and survive in this context are largely unknown. There were considerable impediments to standard approaches for investigation of this unique pathogen, the most problematic being the lack of a long term in vitro culture system. The absence of an ex vivo cultivation method remains today, and many fundamental scientific questions about the basic biology, metabolism, and life cycle of Pneumocystis remain unanswered. Recent progress in sequencing of the Pneumocystis carinii genome, a species infecting rats, permitted a more informative search for genes and biological pathways within this pathogen that are known to be targets for existing antifungal agents. In this work, we review the classes of antifungal drugs with respect to their potential applicability to the treatment of PCP. Classes covered in the review are the azoles, polyenes, allylamines, and echinocandins. Factors limiting the use of standard antifungal treatments and the currently available alternatives (trimethoprim-sulfamethoxazole, atovaquone, and pentamidine) are discussed. A summary of genomic sequences within Pneumocystis carinii associated with the corresponding targeted biological pathways is provided. All sequences are available via Pneumocystis Genome Project at http://pgp.cchmc.org/. PMID:22934582

  16. Synthesis and investigation of novel benzimidazole derivatives as antifungal agents.

    PubMed

    Chandrika, Nishad Thamban; Shrestha, Sanjib K; Ngo, Huy X; Garneau-Tsodikova, Sylvie

    2016-08-15

    The rise and emergence of resistance to antifungal drugs by diverse pathogenic fungal strains have resulted in an increase in demand for new antifungal agents. Various heterocyclic scaffolds with different mechanisms of action against fungi have been investigated in the past. Herein, we report the synthesis and antifungal activities of 18 alkylated mono-, bis-, and trisbenzimidazole derivatives, their toxicities against mammalian cells, as well as their ability to induce reactive oxygen species (ROS) in yeast cells. Many of our bisbenzimidazole compounds exhibited moderate to excellent antifungal activities against all tested fungal strains, with MIC values ranging from 15.6 to 0.975μg/mL. The fungal activity profiles of our bisbenzimidazoles were found to be dependent on alkyl chain length. Our most potent compounds were found to display equal or superior antifungal activity when compared to the currently used agents amphotericin B, fluconazole, itraconazole, posaconazole, and voriconazole against many of the strains tested. PMID:27301676

  17. Research to Identify Effective Antifungal Agents, 1991 Annual Report.

    SciTech Connect

    Schreck, Carl

    1991-09-01

    This study is a continuation of ``Research to Identify Effective Antifungal Agents'' sponsored by Bonneville Power Administration (Schreck et al. 1990). The objectives of the present study was to evaluate up to 10 candidate fungicides.

  18. Research to Identify Effective Antifungal Agents, 1993 Annual Report.

    SciTech Connect

    Schreck, Carl

    1993-10-01

    This study is a continuation of ``Research to Identify Effective Antifungal Agents'' sponsored by Bonneville Power Administration (Schreck et al. 1990, 1991, and 1992). The objectives of the present study were to select and evaluate candidate fungicides.

  19. Pickering emulsions based on cyclodextrins: A smart solution for antifungal azole derivatives topical delivery.

    PubMed

    Leclercq, Loïc; Nardello-Rataj, Véronique

    2016-01-20

    Surfactants are usually used for the preparation of emulsions. Potential drawbacks on the human body or on the environment can be observed for some of them(e.g. skin irritation, hemolysis, protein denaturation, etc.). However, it is possible to use biocompatible emulsifiers such as native cyclodextrins (CDs). The mixture of oil (paraffin oil or isopropyl myristate), water and native CDs results in the formation of Pickering emulsions. The emulsion properties were investigated by ternary phase diagrams elaboration, multiple light scattering, optical and transmission microscopies. The results prove that these Pickering emulsions were very stable against coalescence due to the dense film format the oil/water interface. The rheological behavior has shown that these emulsions remain compatible for topical applications. This kind of emulsions (biocompatibility, stability and surfactant free) has been used to obtain sustainable formulations for antifungal econazole derivatives delivery. Our results prove that these new formulations are at least as active as commercially available formulations. PMID:26616822

  20. Chemosensitization as a Means to Augment Commercial Antifungal Agents

    PubMed Central

    Campbell, Bruce C.; Chan, Kathleen L.; Kim, Jong H.

    2012-01-01

    Antimycotic chemosensitization and its mode of action are of growing interest. Currently, use of antifungal agents in agriculture and medicine has a number of obstacles. Foremost of these is development of resistance or cross-resistance to one or more antifungal agents. The generally high expense and negative impact, or side effects, associated with antifungal agents are two further issues of concern. Collectively, these problems are exacerbated by efforts to control resistant strains, which can evolve into a treadmill of higher dosages for longer periods. This cycle in turn, inflates cost of treatment, dramatically. A further problem is stagnation in development of new and effective antifungal agents, especially for treatment of human mycoses. Efforts to overcome some of these issues have involved using combinations of available antimycotics (e.g., combination therapy for invasive mycoses). However, this approach has had inconsistent success and is often associated with a marked increase in negative side effects. Chemosensitization by natural compounds to increase effectiveness of commercial antimycotics is a somewhat new approach to dealing with the aforementioned problems. The potential for safe natural products to improve antifungal activity has been observed for over three decades. Chemosensitizing agents possess antifungal activity, but at insufficient levels to serve as antimycotics, alone. Their main function is to disrupt fungal stress response, destabilize the structural integrity of cellular and vacuolar membranes or stimulate production of reactive oxygen species, augmenting oxidative stress and apoptosis. Use of safe chemosensitizing agents has potential benefit to both agriculture and medicine. When co-applied with a commercial antifungal agent, an additive or synergistic interaction may occur, augmenting antifungal efficacy. This augmentation, in turn, lowers effective dosages, costs, negative side effects and, in some cases, countermands resistance

  1. The putative ABC transporter encoded by the orf19.4531 plays a role in the sensitivity of Candida albicans cells to azole antifungal drugs.

    PubMed

    Jiang, Linghuo; Xu, Dayong; Chen, Zhen; Cao, Yongbing; Gao, Pinghui; Jiang, Yuanying

    2016-05-01

    ATP-binding cassette (ABC) transporters constitute a large superfamily of integral membrane proteins in prokaryotic and eukaryotic cells. In the human fungal pathogen Candida albicans, there are 28 genes encoding ABC transporters and many of them have not been characterized so far. The orf19.4531 (also known as IPF7530) encodes a putative ABC transporter. In this study, we have demonstrated that disruption of orf19.4531 causes C. albicans cells to become tolerant to azoles, but not to polyene antifungals and terbinafine. Therefore, the protein encoded by orf19.4531 is involved in azole sensitivity and we name it as ROA1, the regulator of azole sensitivity 1 gene. Consistently, we show that the expression of ROA1 is responsive to treatment of either fluconazole or ketoconazole inC. albicans In addition, through a GFP tagging approach, Roa1 is localized in a small punctuate compartment adjacent to the vacuolar membrane. However, ROA1 is not essential for the in vitro filamentation of C. albicans cells. PMID:26975389

  2. Efinaconazole: Developmental and reproductive toxicity potential of a novel antifungal azole.

    PubMed

    Glynn, M; Jo, W; Minowa, K; Sanada, H; Nejishima, H; Matsuuchi, H; Okamura, H; Pillai, R; Mutter, L

    2015-04-01

    Efinaconazole is a new triazole antifungal for topical treatment of onychomycosis. The reproductive and developmental toxicity of efinaconazole was characterized in fertility and early embryonic development (rat), embryo-fetal development (rat and rabbit), and peri/post-natal development (rat) studies in accordance with current ICH guidances. In the fertility study, maternal reproductive toxicity was noted as estrous cycle prolongation (NOAEL=5mg/kg/day) but there were no male reproductive effects even in the presence of paternal toxicity (NOAEL=25mg/kg/day). Rat embryo-fetal and perinatal pup lethality was the most sensitive (NOAEL=5mg/kg/day) efinaconazole developmental toxicity and was noted at maternally toxic doses. Efinaconazole did not affect rabbit embryo-fetal development at maternally toxic doses (NOAEL=10mg/kg/day). No malformations were induced by efinaconazole in rats or rabbits. When compared with systemic exposures observed in onychomycosis patients, embryo-fetal toxicity in rats was noted at high (>100-fold) multiples of systemic exposure. PMID:25527861

  3. Synthesis, Antifungal Activities and Qualitative Structure Activity Relationship of Carabrone Hydrazone Derivatives as Potential Antifungal Agents

    PubMed Central

    Wang, Hao; Ren, Shuang-Xi; He, Ze-Yu; Wang, De-Long; Yan, Xiao-Nan; Feng, Jun-Tao; Zhang, Xing

    2014-01-01

    Aimed at developing novel fungicides for relieving the ever-increasing pressure of agricultural production caused by phytopathogenic fungi, 28 new hydrazone derivatives of carabrone, a natural bioactive sesquisterpene, in three types were designed, synthesized and their antifungal activities against Botrytis cinerea and Colletotrichum lagenarium were evaluated. The result revealed that all the derivatives synthesized exhibited considerable antifungal activities in vitro and in vivo, which led to the improved activities for carabrone and its analogues and further confirmed their potential as antifungal agents. PMID:24619221

  4. Characterization of Tamoxifen as an Antifungal Agent Using the Yeast Schizosaccharomyces Pombe Model Organism.

    PubMed

    Zhang, Xibo; Fang, Yue; Jaiseng, Wurentuya; Hu, Lingling; Lu, Yabin; Ma, Yan; Furuyashiki, Tomoyuki

    2015-01-01

    Tamoxifen, a selective estrogen receptor modulator used for managing breast cancer, is known to have antifungal activity. However, its molecular mechanism remains unknown. Using the fission yeast Schizosaccharomyces pombe as a model organism, we have explored the mechanism involved in antifungal action of tamoxifen. Since tamoxifen was shown to inhibit the binding of calmodulin to calcineurin in fungi, we first examined involvement of these molecules and found that overexpression of a catalytic subunit of calcineurin and its constitutively active mutant as well as calmodulin increases tamoxifen sensitivity. Since terbinafine and azoles inhibit enzymes for ergosterol biosynthesis, Erg1 and Erg11, for their antifungal actions, we also examined involvement of these molecules. Overexpression of Erg1 and Erg11 reduced the sensitivity to terbinafine and azoles, respectively, but increased tamoxifen sensitivity, suggesting that ergosterol biosynthesis is differently related to the action of tamoxifen and those of terbinafine and azoles. To elucidate molecules involved in tamoxifen action, we performed a genome-wide screen for altered sensitivity to tamoxifen using a fission yeast gene deletion library, and identified various hypersensitive and resistant mutants to this drug. Notably, these mutants are rarely overlapped with those identified in similar genetic screens with currently used antifungals, suggesting a novel mode of antifungal action. Furthermore, tamoxifen augmented antifungal actions of terbinafine and azoles, suggesting synergetic actions between these drugs. Therefore, our findings suggest that calmodulin-calcineurin pathway and ergosterol biosynthesis are related to antifungal action of tamoxifen, and propose novel targets for antifungal development as well as combined therapy with tamoxifen for fungal diseases. PMID:26628015

  5. Enhancement of Commercial Antifungal Agents by Kojic Acid

    PubMed Central

    Kim, Jong H.; Chang, Perng-Kuang; Chan, Kathleen L.; Faria, Natália C. G.; Mahoney, Noreen; Kim, Young K.; Martins, Maria de L.; Campbell, Bruce C.

    2012-01-01

    Natural compounds that pose no significant medical or environmental side effects are potential sources of antifungal agents, either in their nascent form or as structural backbones for more effective derivatives. Kojic acid (KA) is one such compound. It is a natural by-product of fungal fermentation commonly employed by food and cosmetic industries. We show that KA greatly lowers minimum inhibitory (MIC) or fungicidal (MFC) concentrations of commercial medicinal and agricultural antifungal agents, amphotericin B (AMB) and strobilurin, respectively, against pathogenic yeasts and filamentous fungi. Assays using two mitogen-activated protein kinase (MAPK) mutants, i.e., sakAΔ, mpkCΔ, of Aspergillus fumigatus, an agent for human invasive aspergillosis, with hydrogen peroxide (H2O2) or AMB indicate such chemosensitizing activity of KA is most conceivably through disruption of fungal antioxidation systems. KA could be developed as a chemosensitizer to enhance efficacy of certain conventional antifungal drugs or fungicides. PMID:23203038

  6. New and emerging antifungal agents: impact on respiratory infections.

    PubMed

    Feldmesser, Marta

    2003-01-01

    Fungal pathogens are increasingly important causes of respiratory disease, yet the number of antifungal agents available for clinical use is limited. Use of amphotericin B deoxycholate is hampered by severe toxicity. Triazole agents currently available have significant drug interactions; fluconazole has a limited spectrum of activity and itraconazole was, until recently, available only in oral formulations with limited bioavailability. The development of resistance to all three agents is increasingly being recognized and some filamentous fungi are resistant to the action of all of these agents. In the past few years, new antifungal agents and new formulations of existing agents have become available.The use of liposomal amphotericin B preparations is associated with reduced, but still substantial, rates of nephrotoxicity and infusion-related reactions. An intravenous formulation of itraconazole has been introduced, and several new triazole agents have been developed, with the view of identifying agents that have enhanced potency, broader spectra of action and improved pharmacodynamic properties. One of these, voriconazole, has completed large-scale clinical trials. In addition, caspofungin, the first of a new class of agents, the echinocandins, which inhibit cell wall glucan synthesis, was approved for use in the US in 2001 as salvage therapy for invasive aspergillosis. It is hoped that the availability of these agents will have a significant impact on the morbidity and mortality of fungal respiratory infections. However, at the present time, our ability to assess their impact is limited by the problematic nature of conducting trials for antifungal therapy. PMID:14719990

  7. From antidiabetic to antifungal: discovery of highly potent triazole-thiazolidinedione hybrids as novel antifungal agents.

    PubMed

    Wu, Shanchao; Zhang, Yongqiang; He, Xiaomeng; Che, Xiaoying; Wang, Shengzheng; Liu, Yang; Jiang, Yan; Liu, Na; Dong, Guoqiang; Yao, Jianzhong; Miao, Zhenyuan; Wang, Yan; Zhang, Wannian; Sheng, Chunquan

    2014-12-01

    In an attempt to discover a new generation of triazole antifungal agents, a series of triazole-thiazolidinedione hybrids were designed and synthesized by molecular hybridization of the antifungal agent fluconazole and rosiglitazone (an antidiabetic). Most of the target compounds showed good to excellent inhibitory activity against a variety of clinically important fungal pathogens. In particular, compounds (Z)-5-(2,4-dichlorobenzylidene)-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione) (15 c), (Z)-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(furan-3-ylmethylene)thiazolidine-2,4-dione (15 j), and (Z)-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(furan-3-ylmethylene)thiazolidine-2,4-dione (15 r) were highly active against Candida albicans, with MIC80 values in the range of 0.03-0.15 μM. Moreover, compounds 15 j and 15 r were found to be effective against four fluconazole-resistant clinical isolates; these two compounds are particularly promising antifungal leads for further optimization. Molecular docking studies revealed that the hydrogen bonding interactions between thiazolidinedione and CYP51 from C. albicans are important for antifungal activity. This study also demonstrates the effectiveness of molecular hybridization in antifungal drug discovery. PMID:25196996

  8. Triazole antifungals: a review.

    PubMed

    Peyton, L R; Gallagher, S; Hashemzadeh, M

    2015-12-01

    Invasive fungal infections and systemic mycosis, whether from nosocomial infection or immunodeficiency, have been on an upward trend for numerous years. Despite advancements in antifungal medication, treatment in certain patients can still be difficult for reasons such as impaired organ function, limited administration routes or poor safety profiles of the available antifungal medications. The growing number of invasive fungal species becoming resistant to current antifungal medications is of appreciable concern. Triazole compounds containing one or more 1,2,4-triazole rings have been shown to contain some of the most potent antifungal properties. Itracon-azole and fluconazole were some of the first triazoles synthesized, but had limitations associated with their use. Second-generation triazoles such as voriconazole, posa-conazole, albaconazole, efinaconazole, ravuconazole and isavuconazole are all derivatives of either itraconazole or fluconazole, and designed to overcome the deficiencies of their parent drugs. The goal of this manuscript is to review antifungal agents derived from triazole. PMID:26798851

  9. Enhancement of commercial antifungal agents by kojic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Kojic acid (KA), a natural by-product of fungal fermentation, is a commonly used food and cosmetic additive. We show that KA increases activity of amphotericin B and strobilurin, medical and agricultural antifungal agents, respectively, possibly targeting the fungal antioxidative system. KA shows pr...

  10. Chemosensitization as a means to augment commercial antifungal agents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is growing list of papers on antimycotic chemosensitization and the mechanisms by which they function. Currently, antifungal agents used in agriculture and in human or veterinary medicine are confronted by a number of obstacles, the main one being continual development of resistance to one, or...

  11. Research to Identify Effective Antifungal Agents, 1992 Annual Report.

    SciTech Connect

    Schreck, Carl

    1993-03-01

    This study is a continuation of ``Research to Identify Effective Antifungal Agents'' sponsored by Bonneville Power Administration (Schreck et al. 1990 and Schreck et al. 1991). The objectives of the present study were to select and evaluate up to 10 candidate fungicides.

  12. [Synthesis and antifungal activity of butenafine hydrochloride (KP-363), a new benzylamine antifungal agent].

    PubMed

    Maeda, T; Takase, M; Ishibashi, A; Yamamoto, T; Sasaki, K; Arika, T; Yokoo, M; Amemiya, K

    1991-02-01

    In screening of new antifungal agents, bis(naphthalenemethyl)amines were found to have more potent antifungal activity than clotrimazole. Studies on their structure-activity relationships indicated that benzylamines had potent antifungal activity. Among them, butenafine hydrochloride (N-p-tert-butylbenzyl-N-methyl-1-naphthalenemethylamine hydrochloride, KP-363) has proved to show the strongest activity. It exhibits a wide spectrum activity in vitro against particularly dermatophytes (87 strains; minimal inhibitory concentration (MIC) range, 0.0015 to 0.05 microgram/ml), and also against Aspergillus (15 strains; MIC range, 0.025 to 0.78 microgram/ml), Cryptococcus neoformans (4 strains; MICs 0.78 and 1.56 micrograms/ml) and yeasts of genus Candida (67 strains; MIC range, 3.13 to greater than 100 micrograms/ml). PMID:2056447

  13. Recent advances in topical formulation carriers of antifungal agents.

    PubMed

    Bseiso, Eman Ahmed; Nasr, Maha; Sammour, Omaima; Abd El Gawad, Nabaweya A

    2015-01-01

    Fungal infections are amongst the most commonly encountered diseases affecting the skin. Treatment approaches include both topical and oral antifungal agents. The topical route is generally preferred due to the possible side effects of oral medication. Advances in the field of formulation may soon render outdated conventional products such as creams, ointments and gels. Several carrier systems loaded with antifungal drugs have demonstrated promising results in the treatment of skin fungal infections. Examples of these newer carriers include micelles, lipidic systems such as solid lipid nanoparticles and nanostructured lipid carriers, microemulsions and vesicular systems such as liposomes, niosomes, transfersomes, ethosomes, and penetration enhancer vesicles. PMID:26261140

  14. Pharmacokinetics of antifungal agents in onychomycoses.

    PubMed

    Debruyne, D; Coquerel, A

    2001-01-01

    Onychomycosis is caused by infection by fungi, mainly dermatophytes and nondermatophyte yeasts or moulds; it affects the fingernails and, more frequently, the toenails. Dermatophytes are responsible for about 90 to 95% of fungal infections. Trichophyton rubrum is the most common dermatophyte; Candida albicans is the major nondermatophyte yeast. Although topical therapy of onchomycosis does not lead to systemic adverse effects or interactions with concomitantly taken drugs, it does not provide high cure rates and requires complete compliance from the patient. At present there are 3 oral antifungal medications that are generally used for the short term treatment of onychomycosis: itraconazole, terbinafine and fluconazole. The persistence of these active drugs in nails allows weekly administration, reduced treatment or a pulse regimen. Good clinical and mycological efficacies are obtained with itraconazole 100 to 200 mg daily, terbinafine 250mg daily for 3 months, or fluconazole 150 mg weekly for at least 6 months. Itraconazole is a synthetic triazole with a broad spectrum of action. It is well absorbed when administered orally and can be detected in nails 1 to 2 weeks after the start of therapy. The nail : plasma ratio stabilises at around 1 by week 18 of treatment. Itraconazole is still detectable in nails 27 weeks after stopping administration. Nail concentrations are higher than the minimum inhibitory concentration (MIC) for most dermatophytes and Candida species from the first month of treatment. The elimination half-life of itraconazole from nails is long, ranging from 32 to 147 days. Terbinafine is a synthetic allylamine that is effective against dermatophytes. Terbinafine is well absorbed from the gastrointestinal tract, and the time to reach effective concentrations in nail is 1 to 2 weeks. The half-life is from 24 to 156 days, explaining the observed persistence of terbinafine in nails for longer than 252 days. Fluconazole is a bis-triazole broad spectrum

  15. Emergence of Azole Resistance in Aspergillus.

    PubMed

    Wiederhold, Nathan P; Patterson, Thomas F

    2015-10-01

    Resistance to the azole antifungals itraconazole, voriconazole, and posaconazole in Aspergillus species is a growing concern. This is especially alarming for A. fumigatus, where acquired resistance has been documented in patients with invasive disease caused by this species that were exposed to these agents, as well as in azole-naive individuals. The primary mechanisms of resistance that have been described in clinical strains include different point mutations in the CYP51A gene, which encodes the enzyme responsible for converting lanosterol to ergosterol via demethylation. Some resistant isolates also contain a tandem repeat in the promoter region of this gene that causes increased expression. These mutations, including TR34/L98H and TR46/Y121F/T289A have also been found in the environment in several areas of the world and have been demonstrated to cause resistance to azole fungicides used in agriculture, thus raising the concern of environmental spread of resistance. Treatment options are limited in patients with infections caused by azole-resistant isolates and include amphotericin B formulations or combination therapy involving an echinocandin. However, there are few clinical data available to help guide therapy, and infections caused by resistant A. fumigatus isolates have been reported to have high mortality rates. PMID:26398534

  16. In Vitro Interactions between Target of Rapamycin Kinase Inhibitor and Antifungal Agents against Aspergillus Species.

    PubMed

    Gao, Lujuan; Ding, Xiaozhen; Liu, Zhun; Wu, Qingzhi; Zeng, Tongxiang; Sun, Yi

    2016-06-01

    In vitro interactions of INK128, a target of rapamycin (TOR) kinase inhibitor, and antifungals, including itraconazole, voriconazole, posaconazole, amphotericin B, and caspofungin, against Aspergillus spp. were assessed with the broth microdilution checkerboard technique. Our results suggested synergistic effects between INK128 and all azoles tested, against multiple Aspergillus fumigatus and Aspergillus flavus isolates. However, no synergistic effects were observed when INK128 was combined with amphotericin B or caspofungin. No antagonism was observed for any combination. PMID:26976874

  17. Breakpoints for antifungal agents: an update from EUCAST focussing on echinocandins against Candida spp. and triazoles against Aspergillus spp.

    PubMed

    Arendrup, Maiken C; Cuenca-Estrella, Manuel; Lass-Flörl, Cornelia; Hope, William W

    2013-12-01

    Candida and Aspergillus infections have emerged as significant pathogens in recent decades. During this same time, broad spectrum triazole and echinocandin antifungal agents have been developed and increasingly used. One consequence of widespread use is leading to the emergence of mutants with acquired resistance mutations. Therefore, accurate susceptibility testing and appropriate clinical breakpoints for the interpretation of susceptibility results have become increasingly important. Here we review the underlying methodology by which breakpoints have been selected by EUCAST (European Committee on Antimicrobial Susceptibility Testing). Five parameters are evaluated: dosing regimens used; EUCAST MIC distributions from multiple laboratories, species and compound specific epidemiological cut off values (upper MIC limits of wild type isolates or ECOFFs), pharmacokinetic/pharmacodynamic relationships and targets associated with outcome and finally clinical data by species and MIC when available. The general principles are reviewed followed by a detailed review of the individual aspects for Candida species and the three echinocandins and for Aspergillus and the three mould-active azoles. This review provides an update of the subcommittee on antifungal susceptibility testing (AFST) of the EUCAST methodology and summarises the current EUCAST breakpoints for Candida and Aspergillus. Recommendations about applicability of antifungal susceptibility testing in the routine setting are also included. PMID:24618110

  18. An overview about the medical use of antifungals in Portugal in the last years.

    PubMed

    Manuel da S Azevedo, Maria; Cruz, Luisa; Pina-Vaz, Cidália; Gonçalves-Rodrigues, Acácio

    2016-05-01

    Despite the introduction of new antifungal agents, the frequency of invasive and mucocutaneous fungal infections as well as resistance to antifungal drugs continues to increase. Over 300 million persons are infected annually with fungi. Resistance to antimicrobials is one of today's major health threats. Can the possible causes of fungal antimicrobial resistance be understood and prevented to minimize risks to public health. We provide an overview of antifungal drug use in European countries, particularly Portugal. We reviewed prescriptions for and over-the-counter sales (OTC) of azoles in Portuguese pharmacies and in alternative shops. We conclude that in Portugal, azole antifungal sales, as well as medical prescribed azoles are very high. The Portuguese population consumes more antifungal drugs per capita than others in Europe. PMID:26865319

  19. Restricticin, a novel glycine-containing antifungal agent.

    PubMed

    Schwartz, R E; Dufresne, C; Flor, J E; Kempf, A J; Wilson, K E; Lam, T; Onishi, J; Milligan, J; Fromtling, R A; Abruzzo, G K

    1991-05-01

    Restricticin (1) is a naturally-occurring antifungal agent which contains triene, pyran and glycine ester functionalities and is unrelated to any previously known family of natural products. This unstable compound, as well as its corresponding N,N-dimethyl derivative (2), have been produced and isolated from both solid and liquid fermentations of Penicillium restrictum. The desglycyl hydrolysis product, restrictinol (3), was produced via the hydrolysis of pure restricticin and as an artifact of the isolation of restricticin. PMID:2061189

  20. Synthesis and biological evaluation of vinyl ether-containing azole derivatives as inhibitors of Trichophyton rubrum.

    PubMed

    Wang, Lulu; Yang, Wenge; Wang, Kai; Zhu, Jing; Shen, Fei; Hu, Yonghong

    2012-07-15

    In an attempt to search for many target compounds with excellent activities, a series of vinyl ether-containing azole derivatives were designed, synthesized, and evaluated as antifungal agents. Results of preliminary antifungal tests against Trichophyton rubrum in vitro indicated that most of the synthesized compounds showed excellent activities. In comparison with fluconazole, itraconazole, voriconazole, omoconazole and amphotericin B, several compounds (such as 7d, 7g and 7h) exhibited more potent inhibitory activities, suggesting that they were promising leads for the development of novel antifungal agents. PMID:22683344

  1. International expert opinion on the management of infection caused by azole-resistant Aspergillus fumigatus.

    PubMed

    Verweij, Paul E; Ananda-Rajah, Michelle; Andes, David; Arendrup, Maiken C; Brüggemann, Roger J; Chowdhary, Anuradha; Cornely, Oliver A; Denning, David W; Groll, Andreas H; Izumikawa, Koichi; Kullberg, Bart Jan; Lagrou, Katrien; Maertens, Johan; Meis, Jacques F; Newton, Pippa; Page, Iain; Seyedmousavi, Seyedmojtaba; Sheppard, Donald C; Viscoli, Claudio; Warris, Adilia; Donnelly, J Peter

    2015-01-01

    An international expert panel was convened to deliberate the management of azole-resistant aspergillosis. In culture-positive cases, in vitro susceptibility testing should always be performed if antifungal therapy is intended. Different patterns of resistance are seen, with multi-azole and pan-azole resistance more common than resistance to a single triazole. In confirmed invasive pulmonary aspergillosis due to an azole-resistant Aspergillus, the experts recommended a switch from voriconazole to liposomal amphotericin B (L-AmB; Ambisome(®)). In regions with environmental resistance rates of ≥10%, a voriconazole-echinocandin combination or L-AmB were favoured as initial therapy. All experts recommended L-AmB as core therapy for central nervous system aspergillosis suspected to be due to an azole-resistant Aspergillus, and considered the addition of a second agent with the majority favouring flucytosine. Intravenous therapy with either micafungin or L-AmB given as either intermittent or continuous therapy was recommended for chronic pulmonary aspergillosis due to a pan-azole-resistant Aspergillus. Local and national surveillance with identification of clinical and environmental resistance patterns, rapid diagnostics, better quality clinical outcome data, and a greater understanding of the factors driving or minimising environmental resistance are areas where research is urgently needed, as well as the development of new oral agents outside the azole drug class. PMID:26282594

  2. Synthesis and biological evaluation of hydrazone derivatives as antifungal agents.

    PubMed

    Casanova, Bruna B; Muniz, Mauro N; de Oliveira, Thayse; de Oliveira, Luís Flavio; Machado, Michel M; Fuentefria, Alexandre M; Gosmann, Grace; Gnoatto, Simone C B

    2015-01-01

    Emerging yeasts are among the most prevalent causes of systemic infections with high mortality rates and there is an urgent need to develop specific, effective and non-toxic antifungal agents to respond to this issue. In this study 35 aldehydes, hydrazones and hydrazines were obtained and their antifungal activity was evaluated against Candida species (C. parapsilosis, C. tropicalis, C. krusei, C. albicans, C. glabrata and C. lusitaneae) and Trichosporon asahii, in an in vitro screening. The minimum inhibitory concentrations (MICs) of the active compounds in the screening was determined against 10 clinical isolates of C. parapsilosis and 10 of T. asahii. The compounds 4-pyridin-2-ylbenzaldehyde] (13a) and tert-butyl-(2Z)-2-(3,4,5-trihydroxybenzylidine)hydrazine carboxylate (7b) showed the most promising MIC values in the range of 16-32 μg/mL and 8-16 μg/mL, respectively. The compounds' action on the stability of the cell membrane and cell wall was evaluated, which suggested the action of the compounds on the fungal cell membrane. Cell viability of leukocytes and an alkaline comet assay were performed to evaluate the cytotoxicity. Compound 13a was not cytotoxic at the active concentrations. These results support the discovery of promising candidates for the development of new antifungal agents. PMID:26007181

  3. Voriconazole is a safe and effective anti-fungal prophylactic agent during induction therapy of acute myeloid leukemia

    PubMed Central

    Shah, Akash; Ganesan, Prasanth; Radhakrishnan, Venkatraman; Kannan, Krishnarathinam; Rajendranath, Rejiv; Mahajan, Vandana; Vijayakumar, Varalakshmi; Ganesan, Trivadi; Sagar, Tenali Gnana

    2016-01-01

    Background: Antifungal prophylaxis (AFP) reduces the incidence of invasive fungal infections (IFIs) during induction therapy of acute myeloid leukemia (AML). Posaconazole is considered the standard of care. Voriconazole, a generic cheaper alternative is a newer generation azole with broad anti-fungal activity. There is limited data on the use of voriconazole as a prophylactic drug. Materials and Methods: A single-center, prospective study was performed during which patients with AML undergoing induction chemotherapy received voriconazole as AFP (April 2012 to February 2014). Outcomes were compared with historical patients who received fluconazole as AFP (January 2011-March 2012, n = 66). Results: Seventy-five patients with AML (median age: 17 years [range: 1-75]; male:female 1.6:1) received voriconazole as AFP. The incidence of proven/probable/possible (ppp) IFI was 6.6% (5/75). Voriconazole and fluconazole cohorts were well-matched with respect to baseline characteristics. Voriconazole (when compared to fluconazole) reduced the incidence of pppIFI (5/75, 6.6% vs. 19/66, 29%; P < 0.001), need to start therapeutic (empiric + pppIFI) antifungals (26/75, 34% vs. 51/66, 48%; P < 0.001) and delayed the start of therapeutic antifungals in those who needed it (day 16 vs. day 10; P < 0.001). Mortality due to IFI was also reduced with the use of voriconazole (1/75, 1.3% vs. 6/66, 9%; P = 0.0507), but this was not significant. Three patients discontinued voriconazole due to side-effects. Conclusion: Voriconazole is an effective and safe oral agent for IFI prophylaxis during induction therapy of AML. Availability of generic equivalents makes this a more economical alternative to posaconazole. PMID:27051159

  4. Pyridine-grafted chitosan derivative as an antifungal agent.

    PubMed

    Jia, Ruixiu; Duan, Yunfei; Fang, Qiang; Wang, Xiangyang; Huang, Jianying

    2016-04-01

    Pyridine moieties were introduced into chitosan by nucleophilic substitution to afford N-(1-carboxybutyl-4-pyridinium) chitosan chloride (pyridine chitosan). The resulting chitosan derivative was well characterized, and its antifungal activity was examined, based on the inhibition of mycelial growth and spore germination. The results indicated that pyridine chitosan exhibited enhanced antifungal activity by comparison with pristine chitosan. The values of the minimum inhibitory concentration and the minimal fungicidal concentration of pyridine chitosan against Fulvia fulva were 0.13 mg/ml and 1 mg/ml, respectively, while the corresponding values against Botrytis cinerea were 0.13 mg/ml and 4 mg/ml, respectively. Severe morphological changes of pyridine chitosan-treated B. cinerea were observed, indicative that pyridine chitosan could damage and deform the structure of fungal hyphae and subsequently inhibit strain growth. Non-toxicity of pyridine chitosan was demonstrated by an acute toxicity study. These results are beneficial for assessing the potential utilization of this chitosan derivative and for exploring new functional antifungal agents with chitosan in the food industry. PMID:26593505

  5. Synthesis, In Vitro Biological Evaluation, and Molecular Docking of New Triazoles as Potent Antifungal Agents.

    PubMed

    Li, Xiang; Liu, Chao; Tang, Sheng; Wu, Qiuye; Hu, Honggang; Zhao, Qingjie; Zou, Yan

    2016-01-01

    Based on the structure of the active site of CYP51 and the structure-activity relationships of azole antifungal compounds that we designed in a previous study, a series of 1-{1-[2-(substitutedbenzyloxy)ethyl]-1H-1,2,3-triazol-4-yl}-2-(2,4-difluorophenyl)-3-(1H-1,2,4-triazol-1-yl)propan-2-ols (6a-n) were designed and synthesized utilizing copper-catalyzed azide-alkyne cycloaddition. Preliminary antifungal tests against eight human pathogenic fungi in vitro showed that all the title compounds exhibited excellent antifungal activities with a broad spectrum in vitro. Molecular docking results indicated that the interaction between the title compounds and CYP51 comprised π-π interactions, hydrophobic interactions, and the narrow hydrophobic cleft. PMID:26641629

  6. Therapeutic drug monitoring (TDM) of antifungal agents: guidelines from the British Society for Medical Mycology

    PubMed Central

    Ashbee, H. Ruth; Barnes, Rosemary A.; Johnson, Elizabeth M.; Richardson, Malcolm D.; Gorton, Rebecca; Hope, William W.

    2014-01-01

    The burden of human disease related to medically important fungal pathogens is substantial. An improved understanding of antifungal pharmacology and antifungal pharmacokinetics–pharmacodynamics has resulted in therapeutic drug monitoring (TDM) becoming a valuable adjunct to the routine administration of some antifungal agents. TDM may increase the probability of a successful outcome, prevent drug-related toxicity and potentially prevent the emergence of antifungal drug resistance. Much of the evidence that supports TDM is circumstantial. This document reviews the available literature and provides a series of recommendations for TDM of antifungal agents. PMID:24379304

  7. 9-O-butyl-13-(4-isopropylbenzyl)berberine, KR-72, Is a Potent Antifungal Agent That Inhibits the Growth of Cryptococcus neoformans by Regulating Gene Expression

    PubMed Central

    Hwang, Hyun Sook; Park, Ki Duk; Kim, Sung Uk; Bahn, Yong-Sun

    2014-01-01

    In this study we explored the mode of action of KR-72, a 9-O-butyl-13-(4-isopropylbenzyl)berberine derivative previously shown to exhibit potent antifungal activity against a variety of human fungal pathogens. The DNA microarray data revealed that KR-72 treatment significantly changed the transcription profiles of C. neoformans, affecting the expression of more than 2,000 genes. Genes involved in translation and transcription were mostly upregulated, whereas those involved in the cytoskeleton, intracellular trafficking, and lipid metabolism were downregulated. KR-72 also exhibited a strong synergistic effect with the antifungal agent FK506. KR-72 treatment regulated the expression of several essential genes, including ECM16, NOP14, HSP10 and MGE1, which are required for C. neoformans growth. The KR-72-mediated induction of MGE1 also likely reduced the viability of C. neoformans by impairing cell cycle or the DNA repair system. In conclusion, KR-72 showed antifungal activity by modulating diverse biological processes through a mode of action distinct from those of clinically available antifungal drugs such as polyene and azole drugs. PMID:25302492

  8. Which antifungal agent for onychomycosis? A pharmacoeconomic analysis.

    PubMed

    Joish, V N; Armstrong, E P

    2001-01-01

    The incidence of fungal nail infections is increasing and this is possibly because of several factors: better methods of detection, a growing population of immunocompromised patients who have a greater susceptibility to such infections, the increased use of immunosuppressive drugs, the increasing number of elderly people, worldwide travel, and the use of communal bathing facilities. Onychomycosis is a fungal infection of the fingernails and toenails that accounts for about 30% of all superficial fungal infections. It is characterised by nail discoloration, thickening and ultimately destruction of the nail plate. Management of this disease has improved significantly and treatment patterns have dramatically changed in recent years as a result of advances in new treatment options (e.g. oral antifungal agents) and changes in treatment regimens (e.g. pulse therapy). Also, newer drugs for onychomycosis have improved tolerability profiles compared with older agents. The overall costs of treating onychomycosis are substantial, and it has been estimated that direct cost for US Medicare patients with the disease is 43 million US dollars per year (year of costing not available). Pharmacoeconomic studies help in the decision-making process when selecting the most cost-effective antifungal agents to treat onychomycosis. To date there have been a number of national and international economic studies aimed at effectively assessing the efficacy and costs of the treatment options available to cure onychomycosis. The objectives of this paper are to (i) review the published findings regarding the epidemiology of onychomycosis; (ii) summarise the original pharmacoeconomic studies that describe the economic impact of the disease; and (iii) address the impact of the disease on patients' health-related quality of life. PMID:11735669

  9. Azole-carbodithioate hybrids as vaginal anti-Candida contraceptive agents: design, synthesis and docking studies.

    PubMed

    Kumar, Lalit; Lal, Nand; Kumar, Vikash; Sarswat, Amit; Jangir, Santosh; Bala, Veenu; Kumar, Lokesh; Kushwaha, Bhavana; Pandey, Atindra K; Siddiqi, Mohammad I; Shukla, Praveen K; Maikhuri, Jagdamba P; Gupta, Gopal; Sharma, Vishnu L

    2013-01-01

    Azole and carbodithioate hybrids were synthesized as alkyl 1H-azole-1-carbodithioates (7-27) and evaluated for spermicidal/microbicidal activities against human sperm, Trichomonas vaginalis and Candida species. Seventeen compounds (7-14, 16-18 and 20-25) showed spermicidal activity at MEC 1.0% (w/v) and permanently immobilized 100% normal human spermatozoa within ∼30 s. Seventeen compounds (7-11, 13-18 and 20-25) exhibited anti-Candida activity (IC50 1.26-47.69 μg/mL). All compounds were devoid of bactericidal activity against four bacterial strains (50.00 μg/mL) and antiprotozoal activity against Trichomonas vaginalis (200.00 μg/mL). Four promising compounds (10, 17, 20 and 22) have better safety profile as compared to Nonoxynol-9 (N-9). Docking study was done to visualize the possible interaction of designed scaffold with prospective receptor (Cyp51) of Candida albicans. PMID:24140949

  10. [Structural and biochemical characteristics of pathogenic fungus: cell walls, lipids and dimorphism, and action modes of antifungal agents].

    PubMed

    Kitajma, Y

    2000-01-01

    Cell walls (0.1-0.5 microm in thickness) of dermatophytes, at least Trichophyton mentagrophytes and Epidermophyton floccosum, are built of microfibrils (20 nm in diameter) and matrix embedding the fibrils. These fibrils are composed of chitin (70-80%) and a small amount of glucans, and the matrix is composed of beta-1-3, beta1-6 glucan, glucomannan, galactomannan and peptides. Another characteristic structure is the outermost layer (20-50 nm in thickness) of the cell wall, which consists of hydrophobic protein rodlets. Lipids are thought to play important roles in the regulation of dimorphism and virulence in pathogenic fungus. Generally, the ratio of phospholipid/ergosterol is less than 1 in yeast form and 2-20 in mycelial form cells in Candida albicans and Sporothrix schenckii. During the transition from yeast to mycelial forms, phosphatidylinositol and phosphatidylserine are reduced, whereas phosphatidylcholine increases. Phospho-lipase D is activated on this transition. Phospholipase B is now known to be a virulence factor in C. albicans. Polyene antifungal agents bind to ergosterol in membrane to form complexes, which generate pores and destroy the structures and functions of membrane. Azole antifungal agents inhibit the synthesis of ergosterol leading to deficiency in ergosterol content in membrane, and impair the function of membranes in fungal cells. We show the effects of polyenes on the ultrastructure of fungal plasma membrane and impairment of ionomycin-induced calcium influx in T. mentagrophytes, so that we can compare the differences in mode of actions between these two groups of agents. PMID:11064317

  11. [Chalcones and their heterocyclic analogs as potential antifungal chemotherapeutic agents].

    PubMed

    Opletalová, V; Sedivý, D

    1999-11-01

    Chalcones and their heterocyclic analogues show various biological effects, e.g. anti-inflammatory, antitumour, antibacterial, antituberculous, antiviral, antiprotozoal, gastroprotective, and others. The present review discusses in greater detail the fungistatic and fungicide properties of these compounds and presents also their chemical structures. The mechanism of antifungal effects of chalcones and their analogues has not been investigated in greater detail. Due to the presence of a reactive ketovinyl moiety in the molecule the compounds of this type are able to react with the thiol groups of enzymes. It cannot be excluded that chalcones interfere with the normal function of the membranes of fungi and moulds. Further investigation of chemical, physical, and biological properties of chalcones and their analogues could lead to the elucidation of the mechanism of their action and finding of effective fungicidal and fungistatic agents in this group of organic substances. PMID:10748740

  12. Augmenting the activity of antifungal agents against aspergilli using structural analogues of benzoic acid as chemosensitizing agents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several benzoic acid analogs showed antifungal activity against strains of Aspergillus flavus, A. fumigatus and A. terreus, causative agents of human aspergillosis. Structure-activity analysis revealed that antifungal activities of benzoic and gallic acids increased by addition of a methyl, methoxyl...

  13. Characterization of Antifungal Activity and Nail Penetration of ME1111, a New Antifungal Agent for Topical Treatment of Onychomycosis.

    PubMed

    Tabata, Yuji; Takei-Masuda, Naomi; Kubota, Natsuki; Takahata, Sho; Ohyama, Makoto; Kaneda, Kaori; Iida, Maiko; Maebashi, Kazunori

    2016-02-01

    Fungal nail infection (onychomycosis) is a prevalent disease in many areas of the world, with a high incidence approaching 23%. Available antifungals to treat the disease suffer from a number of disadvantages, necessitating the discovery of new efficacious and safe antifungals. Here, we evaluate the in vitro antifungal activity and nail penetration ability of ME1111, a novel antifungal agent, along with comparator drugs, including ciclopirox, amorolfine, terbinafine, and itraconazole. ME1111 showed potent antifungal activity against Trichophyton rubrum and Trichophyton mentagrophytes (the major etiologic agents of onychomycosis) strains isolated in Japan and reference fungal strains with an MIC range of 0.12 to 0.5 mg/liter and an MIC50 and MIC90 of 0.5 mg/liter for both. Importantly, none of the tested isolates showed an elevated ME1111 MIC. Moreover, the antifungal activity of ME1111 was minimally affected by 5% wool keratin powder in comparison to the other antifungals tested. The ME1111 solution was able to penetrate human nails and inhibit fungal growth in a dose-dependent manner according to the TurChub assay. In contrast, 8% ciclopirox and 5% amorolfine nail lacquers showed no activity under the same conditions. ME1111 demonstrated approximately 60-fold-greater selectivity in inhibition of Trichophyton spp. than of human cell lines. Our findings demonstrate that ME1111 possesses potent antidermatophyte activity, maintains this activity in the presence of keratin, and possesses excellent human nail permeability. These results suggest that ME1111 is a promising topical medication for the treatment of onychomycosis and therefore warrants further clinical evaluation. PMID:26643333

  14. Antifungal Activities of SCY-078 (MK-3118) and Standard Antifungal Agents against Clinical Non-Aspergillus Mold Isolates

    PubMed Central

    Lamoth, Frédéric

    2015-01-01

    The limited armamentarium of active and oral antifungal drugs against emerging non-Aspergillus molds is of particular concern. Current antifungal agents and the new orally available beta-1,3-d-glucan synthase inhibitor SCY-078 were tested in vitro against 135 clinical non-Aspergillus mold isolates. Akin to echinocandins, SCY-078 showed no or poor activity against Mucoromycotina and Fusarium spp. However, SCY-078 was highly active against Paecilomyces variotii and was the only compound displaying some activity against notoriously panresistant Scedosporium prolificans. PMID:25896696

  15. The role of antifungal and antiviral agents in primary dental care.

    PubMed

    Lewis, Mike

    2014-11-01

    In comparison to the range of antibiotics used in medicine, the spectrum of antifungal and antiviral drugs used in primary dental care is relatively limited. In practical terms, there are only three antifungal agents and two antiviral agents that have a role. This paper will describe the clinical presentation of orofacial candidal and viral infections and the use of antimicrobial drugs in their management. PMID:25668378

  16. Design, Synthesis and Structure-Activity Relationships of Novel Chalcone-1,2,3-triazole-azole Derivates as Antiproliferative Agents.

    PubMed

    Zhang, Sai-Yang; Fu, Dong-Jun; Yue, Xiao-Xin; Liu, Ying-Chao; Song, Jian; Sun, Hui-Hui; Liu, Hong-Min; Zhang, Yan-Bing

    2016-01-01

    A series of novel chalcone-1,2,3-triazole-azole hybrids were designed, synthesized and evaluated for their antiproliferative activity against three selected cancer cell lines (SK-N-SH, EC-109 and MGC-803). Most of the synthesized compounds exhibited moderate to good activity against all the cancer cell lines selected. Particularly, compound I-21 showed the most excellent antiproliferative activity with an IC50 value of 1.52 μM against SK-N-SH cancer cells. Further mechanism studies revealed that compound I-21 induced morphological changes of SK-N-SH cancer cells possibly by inducing apoptosis. Novel chalcone-1,2,3-triazole-azole derivatives in this work might be a series of promising lead compounds to develop anticancer agents for treating neuroblastoma. PMID:27213317

  17. History of the development of azole derivatives.

    PubMed

    Maertens, J A

    2004-03-01

    Until the 1940s, relatively few agents were available for the treatment of systemic fungal infections. The development of the polyene antifungals represented a major advance in medical mycology. Although amphotericin B quickly became the mainstay of therapy for serious infections, its use was associated with infusion-related side-effects and dose-limiting nephrotoxicity. The continued search for new and less toxic antifungals led to the discovery of the azoles several decades later. Ketoconazole, the first available compound for the oral treatment of systemic fungal infections, was released in the early 1980s. For almost a decade, ketoconazole was regarded as the drug of choice in nonlife-threatening endemic mycoses. The introduction of the first-generation triazoles represented a second major advance in the treatment of fungal infections. Both fluconazole and itraconazole displayed a broader spectrum of antifungal activity than the imidazoles and had a markedly improved safety profile compared with amphotericin B and ketoconazole. Despite widespread use, however, these agents became subject to a number of clinically important limitations related to their suboptimal spectrum of activity, the development of resistance, the induction of hazardous drug-drug interactions, their less than optimal pharmacokinetic profile (itraconazole capsules), and toxicity. In order to overcome these limitations, several analogues have been developed. These so-called 'second-generation' triazoles, including voriconazole, posaconazole and ravuconazole, have greater potency and possess increased activity against resistant and emerging pathogens, in particular against Aspergillus spp. If the toxicity profile of these agents is comparable to or better than that of the first-generation triazoles and drug interactions remain manageable, then these compounds represent a true expansion of our antifungal arsenal. PMID:14748798

  18. Amphiphilic Tobramycin Analogues as Antibacterial and Antifungal Agents

    PubMed Central

    Shrestha, Sanjib K.; Fosso, Marina Y.; Green, Keith D.

    2015-01-01

    In this study, we investigated the in vitro antifungal activities, cytotoxicities, and membrane-disruptive actions of amphiphilic tobramycin (TOB) analogues. The antifungal activities were established by determination of MIC values and in time-kill studies. Cytotoxicity was evaluated in mammalian cell lines. The fungal membrane-disruptive action of these analogues was studied by using the membrane-impermeable dye propidium iodide. TOB analogues bearing a linear alkyl chain at their 6″-position in a thioether linkage exhibited chain length-dependent antifungal activities. Analogues with C12 and C14 chains showed promising antifungal activities against tested fungal strains, with MIC values ranging from 1.95 to 62.5 mg/liter and 1.95 to 7.8 mg/liter, respectively. However, C4, C6, and C8 TOB analogues and TOB itself exhibited little to no antifungal activity. Fifty percent inhibitory concentrations (IC50s) for the most potent TOB analogues (C12 and C14) against A549 and Beas 2B cells were 4- to 64-fold and 32- to 64-fold higher, respectively, than their antifungal MIC values against various fungi. Unlike conventional aminoglycoside antibiotics, TOB analogues with alkyl chain lengths of C12 and C14 appear to inhibit fungi by inducing apoptosis and disrupting the fungal membrane as a novel mechanism of action. Amphiphilic TOB analogues showed broad-spectrum antifungal activities with minimal mammalian cell cytotoxicity. This study provides novel lead compounds for the development of antifungal drugs. PMID:26033722

  19. Synergistic combinations of antifungals and anti-virulence agents to fight against Candida albicans

    PubMed Central

    Cui, Jinhui; Ren, Biao; Tong, Yaojun; Dai, Huanqin; Zhang, Lixin

    2015-01-01

    Candida albicans, one of the pathogenic Candida species, causes high mortality rate in immunocompromised and high-risk surgical patients. In the last decade, only one new class of antifungal drug echinocandin was applied. The increased therapy failures, such as the one caused by multi-drug resistance, demand innovative strategies for new effective antifungal drugs. Synergistic combinations of antifungals and anti-virulence agents highlight the pragmatic strategy to reduce the development of drug resistant and potentially repurpose known antifungals, which bypass the costly and time-consuming pipeline of new drug development. Anti-virulence and synergistic combination provide new options for antifungal drug discovery by counteracting the difficulty or failure of traditional therapy for fungal infections. PMID:26048362

  20. Acquired multi-azole resistance in Candida tropicalis during persistent urinary tract infection in a dog

    PubMed Central

    Álvarez-Pérez, Sergio; García, Marta E.; Cutuli, María Teresa; Fermín, María Luisa; Daza, María Ángeles; Peláez, Teresa; Blanco, José L.

    2016-01-01

    Multi-azole resistance acquisition by Candida tropicalis after prolonged antifungal therapy in a dog with urinary candidiasis is reported. Pre- and post-azole treatment isolates were clonally related and had identical silent mutations in the ERG11 gene, but the latter displayed increased azole minimum inhibitory concentrations. A novel frameshift mutation in ERG3 was found in some isolates recovered after resistance development, so it appears unlikely that this mutation is responsible for multi-azole resistance. PMID:26949597

  1. Acquired multi-azole resistance in Candida tropicalis during persistent urinary tract infection in a dog.

    PubMed

    Álvarez-Pérez, Sergio; García, Marta E; Cutuli, María Teresa; Fermín, María Luisa; Daza, María Ángeles; Peláez, Teresa; Blanco, José L

    2016-03-01

    Multi-azole resistance acquisition by Candida tropicalis after prolonged antifungal therapy in a dog with urinary candidiasis is reported. Pre- and post-azole treatment isolates were clonally related and had identical silent mutations in the ERG11 gene, but the latter displayed increased azole minimum inhibitory concentrations. A novel frameshift mutation in ERG3 was found in some isolates recovered after resistance development, so it appears unlikely that this mutation is responsible for multi-azole resistance. PMID:26949597

  2. Isavuconazole: Pharmacology, Pharmacodynamics, and Current Clinical Experience with a New Triazole Antifungal Agent.

    PubMed

    Rybak, Jeffrey M; Marx, Kayleigh R; Nishimoto, Andrew T; Rogers, P David

    2015-11-01

    Coinciding with the continually increasing population of immunocompromised patients worldwide, the incidence of invasive fungal infections has grown over the past 4 decades. Unfortunately, infections caused by both yeasts such as Candida and molds such as Aspergillus or Mucorales remain associated with unacceptably high morbidity and mortality. In addition, the available antifungals with proven efficacy in the treatment of these infections remain severely limited. Although previously available second-generation triazole antifungals have significantly expanded the spectrum of the triazole antifungal class, these agents are laden with shortcomings in their safety profiles as well as formulation and pharmacokinetic challenges. Isavuconazole, administered as the prodrug isavuconazonium, is the latest second-generation triazole antifungal to receive U.S. Food and Drug Administration approval. Approved for the treatment of both invasive aspergillosis and invasive mucormycosis, and currently under investigation for the treatment of candidemia and invasive candidiasis, isavuconazole may have therapeutic advantages over its predecessors. With clinically relevant antifungal potency against a broad range of yeasts, dimorphic fungi, and molds, isavuconazole has a spectrum of activity reminiscent of the polyene amphotericin B. Moreover, clinical experience thus far has revealed isavuconazole to be associated with fewer toxicities than voriconazole, even when administered without therapeutic drug monitoring. These characteristics, in an agent available in both a highly bioavailable oral and a β-cyclodextrin-free intravenous formulation, will likely make isavuconazole a welcome addition to the triazole class of antifungals. PMID:26598096

  3. Impact of First-Line Antifungal Agents on the Outcomes and Costs of Candidemia

    PubMed Central

    Ha, Young Eun; Joo, Eun-Jeong; Kim, Shin Woo; Jung, Sook-In; Chang, Hyun Ha; Park, Kyong Hwa; Han, Sang Hoon

    2012-01-01

    Candida species are the leading causes of invasive fungal infection among hospitalized patients and are responsible for major economic burdens. The goals of this study were to estimate the costs directly associated with the treatment of candidemia and factors associated with increased costs, as well as the impact of first-line antifungal agents on the outcomes and costs. A retrospective study was conducted in a sample of 199 patients from four university-affiliated tertiary care hospitals in Korea over 1 year. Only costs attributable to the treatment of candidemia were estimated by reviewing resource utilization during treatment. Risk factors for increased costs, treatment outcome, and hospital length of stay (LOS) were analyzed. Approximately 65% of the patients were treated with fluconazole, and 28% were treated with conventional amphotericin B. The overall treatment success rate was 52.8%, and the 30-day mortality rate was 47.9%. Hematologic malignancy, need for mechanical ventilation, and treatment failure of first-line antifungal agents were independent risk factors for mortality. The mean total cost for the treatment of candidemia was $4,743 per patient. Intensive care unit stay at candidemia onset and antifungal switch to second-line agents were independent risk factors for increased costs. The LOS was also significantly longer in patients who switched antifungal agents to second-line drugs. Antifungal switch to second-line agents for any reasons was the only modifiable risk factor of increased costs and LOS. Choosing an appropriate first-line antifungal agent is crucial for better outcomes and reduced hospital costs of candidemia. PMID:22526315

  4. In vitro susceptibility of dermatomycoses agents to six antifungal drugs and evaluation by fractional inhibitory concentration index of combined effects of amorolfine and itraconazole in dermatophytes.

    PubMed

    Tamura, Takashi; Asahara, Miwa; Yamamoto, Mikachi; Yamaura, Mariko; Matsumura, Mitsuru; Goto, Kazuo; Rezaei-Matehkolaei, Ali; Mirhendi, Hossein; Makimura, Miho; Makimura, Koichi

    2014-01-01

    To investigate the antifungal drug susceptibility of fungi responsible for dermatomycoses, minimum inhibition concentration (MIC) tests were performed in 44 strains of dermatophytes, including Trichophyton rubrum, Trichophyton mentagrophytes, Trichophyton verrucosum, Trichophyton tonsurans, Microsporum canis, Microsporum gypseum and Epidermophyton floccosum, with six antifungal drugs (amorolfine, terbinafine, butenafine, ketoconazole, itraconazole and bifonazole) by broth microdilution assay according to Clinical Laboratory Standard Institute protocols. Six possible dermatomycosis-causing non-dermatophytic fungi were also tested. The two major causes of tinea, T. rubrum and T. mentagrophytes, showed significantly different sensitivities to ketoconazole and bifonazole. Clinically derived dermatophytes were sensitive to the six antifungal drugs tested. However, non-dermatophytes, especially Fusarium spp., tended to be resistant to these antifungal drugs. In Trichophyton spp., the MICs of non-azole drugs had narrower distributions than those of azoles. To evaluate the effects of antifungal drug combinations, the fractional inhibitory concentration index was calculated for the combination of amorolfine and itraconazole as representative external and internal drugs for dermatophytes. It was found that this combination had synergistic or additive effects on most dermatophytes, and had no antagonistic effects. The variation in susceptibility of clinically derived fungal isolates indicates that identification of causative fungi is indispensable for appropriately choosing effective antifungal drugs in the early stages of infection. The results of combination assay suggest that multiple drugs with different antifungal mechanisms against growth of dermatophytes should be used to treat refractory dermatomycoses, especially onychomycosis. PMID:24215461

  5. Augmenting the activity of antifungal agents against aspergilli using structural analogues of benzoic acid as chemosensitizing agents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Structure-activity analysis revealed that antifungal activities of benzoic and gallic acids were increased against strains of Aspergillus flavus, A. fumigatus and A. terreus, causative agents of human aspergillosis, by addition of a methyl, methoxyl or a chloro group at position 4 of the aromatic ri...

  6. Design, synthesis and molecular docking studies of novel triazole as antifungal agent.

    PubMed

    Chai, Xiaoyun; Zhang, Jun; Cao, Yongbing; Zou, Yan; Wu, Qiuye; Zhang, Dazhi; Jiang, Yuanying; Sun, Qingyan

    2011-07-01

    In order to meet the urgent need for novel antifungal agents with improved activity and broader spectrum, a series of 1-(1H-1,2,4-triazol-1-yl)-2-(2,4-difluorophenyl)-3-[(4-substituted trifluoromethyl phenyl)-piperazin-1-yl]-propan-2-ols were designed, synthesized and evaluated as antifungal agents. The MIC(80) values indicate that the compounds 7a-7q, 8a-8d showed higher antifungal activities against Candida albicans than 5a-5i, 6a-6j. Moreover, the molecular model for the binding between compound 5a, 7a and the active site of CACYP51 was provided based on the computational docking results, and the structure-activity relationship was analyzed. PMID:21531485

  7. Mechanism of Action of Efinaconazole, a Novel Triazole Antifungal Agent

    PubMed Central

    Nagashima, Maria; Shibanushi, Toshiyuki; Iwata, Atsushi; Kangawa, Yumi; Inui, Fumie; Siu, William J. Jo; Pillai, Radhakrishnan; Nishiyama, Yayoi

    2013-01-01

    The mechanism of action of efinaconazole, a new triazole antifungal, was investigated with Trichophyton mentagrophytes and Candida albicans. Efinaconazole dose-dependently decreased ergosterol production and accumulated 4,4-dimethylsterols and 4α-methylsterols at concentrations below its MICs. Efinaconazole induced morphological and ultrastructural changes in T. mentagrophytes hyphae that became more prominent with increasing drug concentrations. In conclusion, the primary mechanism of action of efinaconazole is blockage of ergosterol biosynthesis, presumably through sterol 14α-demethylase inhibition, leading to secondary degenerative changes. PMID:23459486

  8. Synergistic combination of violacein and azoles that leads to enhanced killing of major human pathogenic dermatophytic fungi Trichophyton rubrum

    PubMed Central

    Anju, S.; Kumar, Nishanth S.; Krishnakumar, B.; Kumar, B. S. Dileep

    2015-01-01

    Superficial mycoses caused by dermatophytic fungi such as Trichophyton rubrum represent the most common type of worldwide human infection affecting various keratinized tissues in our body such as the skin, hair, and nails, etc. The dermatophytic infection is a significant public health threat due to its persistent nature and high recurrence rates, and thus alternative treatments to cure this fungal infection are urgently required. The present study mainly focused on the synergistic activity of violacein with four azole drugs (ketoconazole, fluconazole, clotrimazole, and itraconazole) against T. rubrum. The synergistic antifungal activities of violacein and azoles were measured by checkerboard microdilution and time-kill assays. In our study, combinations of violacein and azoles predominantly recorded synergistic effect (FIC index < 0.5). Significant synergistic value was recorded by the combination of violacein and clotrimazole. Time-kill assay by the combination of MIC concentration of violacein and azoles recorded that the growth of the T. rubrum was significantly arrested after 4–12 h of treatment. The combination of violacein and azoles leads to the enhanced inhibition of mycelial growth and conidial germination. Moreover combination enhanced the rate of release of intracellular materials. Morphological changes by SEM analysis were also prominent with the combination. A normal human cell line [Foreskin (FS) normal fibroblast] was used to check the cytotoxicity of violacein. Interestingly violacein recorded no cytotoxicity up to 100 μg/ml. The in vitro synergistic effect of violacein and azoles against clinically relevant fungi, T. rubrum, is reported here for the first time. Finally, our findings support the potential use of the violacein as an antifungal agent especially against dermatophytic fungi T. rubrum. PMID:26322275

  9. Screening of Pharmacologically Active Small Molecule Compounds Identifies Antifungal Agents Against Candida Biofilms

    PubMed Central

    Watamoto, Takao; Egusa, Hiroshi; Sawase, Takashi; Yatani, Hirofumi

    2015-01-01

    Candida species have emerged as important and common opportunistic human pathogens, particularly in immunocompromised individuals. The current antifungal therapies either have toxic side effects or are insufficiently effect. The aim of this study is develop new small-molecule antifungal compounds by library screening methods using Candida albicans, and to evaluate their antifungal effects on Candida biofilms and cytotoxic effects on human cells. Wild-type C. albicans strain SC5314 was used in library screening. To identify antifungal compounds, we screened a small-molecule library of 1,280 pharmacologically active compounds (LOPAC1280TM) using an antifungal susceptibility test (AST). To investigate the antifungal effects of the hit compounds, ASTs were conducted using Candida strains in various growth modes, including biofilms. We tested the cytotoxicity of the hit compounds using human gingival fibroblast (hGF) cells to evaluate their clinical safety. Only 35 compounds were identified by screening, which inhibited the metabolic activity of C. albicans by >50%. Of these, 26 compounds had fungistatic effects and nine compounds had fungicidal effects on C. albicans. Five compounds, BAY11-7082, BAY11-7085, sanguinarine chloride hydrate, ellipticine and CV-3988, had strong fungicidal effects and could inhibit the metabolic activity of Candida biofilms. However, BAY11-7082, BAY11-7085, sanguinarine chloride hydrate and ellipticine were cytotoxic to hGF cells at low concentrations. CV-3988 showed no cytotoxicity at a fungicidal concentration. Four of the compounds identified, BAY11-7082, BAY11-7085, sanguinarine chloride hydrate and ellipticine, had toxic effects on Candida strains and hGF cells. In contrast, CV-3988 had fungicidal effects on Candida strains, but low cytotoxic effects on hGF cells. Therefore, this screening reveals agent, CV-3988 that was previously unknown to be antifungal agent, which could be a novel therapies for superficial mucosal candidiasis. PMID

  10. Sulfonyl Azoles in the Synthesis of 3-Functionalized Azole Derivatives.

    PubMed

    Palmieri, Alessandro; Petrini, Marino

    2016-06-01

    Sulfonyl indoles, as well as related azolyl derivatives, have been recently introduced in synthesis as stable precursors of reactive indolenine intermediates. This personal account reports on the discovery of sulfonyl azoles and their practical utilization in many synthetic processes for the preparation of functionalized 3-substituted indoles, indazoles, and pyrroles. The indolenine intermediates obtained by treatment of sulfonyl azoles with Brønsted bases or Lewis acids can be considered as vinylogous imino derivatives that can be made to react with different nucleophilic reagents. These include organometallic reagents, reducing agents, stabilized carbanions, and heteronucleophiles. The controlled and mild conditions for the generation of indolenines from sulfonyl azoles make these substrates particularly useful in asymmetric synthesis, exploiting organo- or metal-catalyzed processes. Although less exploited, sulfonyl indoles can also be involved in photochemical processes for the preparation of polycyclic derivatives. PMID:27147297

  11. Penetration of anti-infective agents into pulmonary epithelial lining fluid: focus on antifungal, antitubercular and miscellaneous anti-infective agents.

    PubMed

    Rodvold, Keith A; Yoo, Liz; George, Jomy M

    2011-11-01

    Epithelial lining fluid (ELF) is often considered to be the site of extracellular pulmonary infections. During the past 25 years, a limited number of studies have evaluated the intrapulmonary penetration of antifungal, antitubercular, antiparasitic and antiviral agents. For antifungal agents, differences in drug concentrations in ELF or bronchoalveolar lavage (BAL) fluid were observed among various formulations or routes of administration, and between agents within the same class. Aerosolized doses of deoxycholate amphotericin B, liposomal amphotericin B and amphotericin B lipid complex resulted in higher concentrations in ELF or BAL fluid than after intravenous administration. The mean concentrations in ELF following intravenous administration of both anidulafungin and micafungin ranged between 0.04 and 1.38 μg/mL, and the ELF to plasma concentration ratios (based on the area under the concentration-time curve for total drug concentrations) were between 0.18 and 0.22 during the first 3 days of therapy. Among the azole agents, intravenous administration of voriconazole resulted in the highest mean ELF concentrations (range 10.1-48.3 μg/mL) and ratio of penetration (7.1). The range of mean ELF concentrations of itraconazole and posaconazole following oral administration was 0.2-1.9 μg/mL, and the ELF to plasma concentration ratios were <1. A series of studies have evaluated the intrapulmonary penetration of first- and second-line oral antitubercular agents in healthy adult subjects and patients with AIDS. The ELF to plasma concentration ratio was >1 for isoniazid, ethambutol, pyrazinamide and ethionamide. For rifampicin (rifampin) and rifapentine, the ELF to plasma concentration ratio ranged between 0.2 and 0.32, but in alveolar macrophages the concentration of rifampicin was much higher (145-738 μg/mL compared with 3.3-7.5 μg/mL in ELF). No intrapulmonary studies have been conducted for rifabutin. Sex, AIDS status or smoking history had no significant effects

  12. Pivotal Role for a Tail Subunit of the RNA Polymerase II Mediator Complex CgMed2 in Azole Tolerance and Adherence in Candida glabrata

    PubMed Central

    Borah, Sapan; Shivarathri, Raju; Srivastava, Vivek Kumar; Ferrari, Sélène; Sanglard, Dominique

    2014-01-01

    Antifungal therapy failure can be associated with increased resistance to the employed antifungal agents. Candida glabrata, the second most common cause of invasive candidiasis, is intrinsically less susceptible to the azole class of antifungals and accounts for 15% of all Candida bloodstream infections. Here, we show that C. glabrata MED2 (CgMED2), which codes for a tail subunit of the RNA polymerase II Mediator complex, is required for resistance to azole antifungal drugs in C. glabrata. An inability to transcriptionally activate genes encoding a zinc finger transcriptional factor, CgPdr1, and multidrug efflux pump, CgCdr1, primarily contributes to the elevated susceptibility of the Cgmed2Δ mutant toward azole antifungals. We also report for the first time that the Cgmed2Δ mutant exhibits sensitivity to caspofungin, a constitutively activated protein kinase C-mediated cell wall integrity pathway, and elevated adherence to epithelial cells. The increased adherence of the Cgmed2Δ mutant was attributed to the elevated expression of the EPA1 and EPA7 genes. Further, our data demonstrate that CgMED2 is required for intracellular proliferation in human macrophages and modulates survival in a murine model of disseminated candidiasis. Lastly, we show an essential requirement for CgMed2, along with the Mediator middle subunit CgNut1 and the Mediator cyclin-dependent kinase/cyclin subunit CgSrb8, for the high-level fluconazole resistance conferred by the hyperactive allele of CgPdr1. Together, our findings underscore a pivotal role for CgMed2 in basal tolerance and acquired resistance to azole antifungals. PMID:25070095

  13. Antifungal agents against Aspergillus niger for rearing rice leaffolder larvae (Lepidoptera: Pyralidae) on artificial diet.

    PubMed

    Su, Jianya; Wang, Ye-Cheng; Zhang, Shu-Kun; Ren, Xiu-Bei

    2014-06-01

    Mold contamination is an important issue in insect mass rearing. Frequently used antifungal agents such as sorbic acid and methylparaben have negative impact on many lepidopteran larvae, which might be one of the reasons for the difficulty in rearing rice leaffolder, Cnaphalocrocis medinalis (Güenée). In this study, 19 antifungal agents, including 7 food preservatives, 6 antifungal drugs, and 6 agricultural fungicides, were screened for their inhibitory activities on Aspergillus niger in diets. The results demonstrated that most of the tested chemicals are unsuitable as mold inhibitors in the diets of the rice leaffolder, and the rice leaffolder neonate is sensitive to sorbic acid and methylparaben. These two mold inhibitors at commonly used concentrations were shown to impact the survival of rice leaffolder larvae fed on artificial diets. Among the tested mold inhibitors, natamycin was the safest for the rice leaffolder larvae. Much higher larva survival was observed for the larvae fed on diets containing natamycin as an antifungal agent (59 and 72% at 200 and 400 ppm, respectively). Two agricultural fungicides, tebuconazole and azoxystrobin, are also potent as mold inhibitors when used in insect diets. The mixed use of natamycin and sorbic acid, or methylparaben, and the mixed use of sorbic acid and azoxystrobin resulted in significantly higher larva survival than sorbic acid + methylparaben. Natamycin + azoxystrobin and sorbic acid + tebuconazole resulted in larva survival similar to that of sorbic acid + methylparaben. The ternary combination of natamycin, sorbic acid, and methylparaben was the best combination for the rearing of rice leaffolder. PMID:25026669

  14. Outcome of empirical or targeted antifungal therapy after antifungal prophylaxis in febrile neutropenia.

    PubMed

    Hahn-Ast, C; Felder, L; Mayer, K; Mückter, S; Ruhnke, M; Hein, R; Hellmich, M; Schwab, K; Rachow, T; Brossart, P; von Lilienfeld-Toal, M

    2016-05-01

    Azole prophylaxis has been shown to be effective in preventing invasive fungal infections (IFIs) and increasing survival in patients with prolonged neutropenia after myelosuppressive chemotherapy for haematological malignancies. Similarly, empirical antifungal therapy for persistent neutropenic fever has been shown to reduce IFI-related mortality. However, to date, there is little information with regard to the outcome of patients who receive both strategies. Here, we present our retrospective data on three cohorts of patients receiving empirical or targeted antifungal therapy after different antifungal prophylaxis regimens. All records from patients who received myelosuppressive induction chemotherapy for acute myelogenous leukemia (AML) in our centre from 2004-2010 were analysed. From 2004-2006, itraconazole was used as antifungal prophylaxis; for the first 6 months in 2007, local polyenes and from mid-2007 till 2010, posaconazole. Data of 315 courses of chemotherapy in 211 patients were analysed. Antifungal therapy (empirical or targeted, time point and antifungal agent at the physician's discretion) was initiated in 50/174 (29 %), 7/18 (39 %) and 34/123 courses (28 %, p = 0.615) in the itra cohort, the cohort without systemic prophylaxis and the posa cohort, respectively, and was effective in 24/50 (48 %), 5/7 (71 %) and 22/34 courses (65 %, p = 0.221), respectively. IFI occurred in 25/174 (14 %), 4/18 (22 %) and 16/123 (13 %) courses, respectively (p = 0.580). IFI-related survival was not different in the three cohorts. Antifungal treatment in patients with AML who received azole prophylaxis resulted in the expected efficacy-importantly, prior posaconazole prophylaxis did not render subsequent antifungal treatment less effective than prior itraconazole prophylaxis. PMID:27021301

  15. Gene Expression Response of Trichophyton rubrum during Coculture on Keratinocytes Exposed to Antifungal Agents

    PubMed Central

    Komoto, Tatiana Takahasi; Bitencourt, Tamires Aparecida; Silva, Gabriel; Beleboni, Rene Oliveira; Marins, Mozart; Fachin, Ana Lúcia

    2015-01-01

    Trichophyton rubrum is the most common causative agent of dermatomycoses worldwide, causing infection in the stratum corneum, nails, and hair. Despite the high prevalence of these infections, little is known about the molecular mechanisms involved in the fungal-host interaction, particularly during antifungal treatment. The aim of this work was to evaluate the gene expression of T. rubrum cocultured with keratinocytes and treated with the flavonoid trans-chalcone and the glycoalkaloid α-solanine. Both substances showed a marked antifungal activity against T. rubrum strain CBS (MIC = 1.15 and 17.8 µg/mL, resp.). Cytotoxicity assay against HaCaT cells produced IC50 values of 44.18 to trans-chalcone and 61.60 µM to α-solanine. The interaction of keratinocytes with T. rubrum conidia upregulated the expression of genes involved in the glyoxylate cycle, ergosterol synthesis, and genes encoding proteases but downregulated the ABC transporter TruMDR2 gene. However, both antifungals downregulated the ERG1 and ERG11, metalloprotease 4, serine proteinase, and TruMDR2 genes. Furthermore, the trans-chalcone downregulated the genes involved in the glyoxylate pathway, isocitrate lyase, and citrate synthase. Considering the urgent need for more efficient and safer antifungals, these results contribute to a better understanding of fungal-host interactions and to the discovery of new antifungal targets. PMID:26257814

  16. Biogenic silver nanoparticles: efficient and effective antifungal agents

    NASA Astrophysics Data System (ADS)

    Netala, Vasudeva Reddy; Kotakadi, Venkata Subbaiah; Domdi, Latha; Gaddam, Susmila Aparna; Bobbu, Pushpalatha; Venkata, Sucharitha K.; Ghosh, Sukhendu Bikash; Tartte, Vijaya

    2016-04-01

    Biogenic synthesis of silver nanoparticles (AgNPs) by exploiting various plant materials is an emerging field and considered green nanotechnology as it involves simple, cost effective and ecofriendly procedure. In the present study AgNPs were successfully synthesized using aqueous callus extract of Gymnema sylvestre. The aqueous callus extract treated with 1nM silver nitrate solution resulted in the formation of AgNPs and the surface plasmon resonance (SPR) of the formed AgNPs showed a peak at 437 nm in the UV Visible spectrum. The synthesized AgNPs were characterized using Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), and X-ray diffraction spectroscopy (XRD). FTIR spectra showed the peaks at 3333, 2928, 2361, 1600, 1357 and 1028 cm-1 which revealed the role of different functional groups possibly involved in the synthesis and stabilization of AgNPs. TEM micrograph clearly revealed the size of the AgNPs to be in the range of 3-30 nm with spherical shape and poly-dispersed nature; it is further confirmed by Particle size analysis that the stability of AgNPs is due its high negative Zeta potential (-36.1 mV). XRD pattern revealed the crystal nature of the AgNPs by showing the braggs peaks corresponding to (111), (200), (220) and (311) planes of face-centered cubic crystal phase of silver. Selected area electron diffraction pattern showed diffraction rings and confirmed the crystalline nature of synthesized AgNPs. The synthesized AgNPs exhibited effective antifungal activity against Candida albicans, Candida nonalbicans and Candida tropicalis.

  17. In Vitro Activity of ASP2397 against Aspergillus Isolates with or without Acquired Azole Resistance Mechanisms.

    PubMed

    Arendrup, Maiken Cavling; Jensen, Rasmus Hare; Cuenca-Estrella, Manuel

    2016-01-01

    ASP2397 is a new compound with a novel and as-yet-unknown target different from that of licensed antifungal agents. It has activity against Aspergillus and Candida glabrata. We compared its in vitro activity against wild-type and azole-resistant A. fumigatus and A. terreus isolates with that of amphotericin B, itraconazole, posaconazole, and voriconazole. Thirty-four isolates, including 4 wild-type A. fumigatus isolates, 24 A. fumigatus isolates with alterations in CYP51A TR/L98H (5 isolates), M220 (9 isolates), G54 (9 isolates), and HapE (1 isolate), and A. terreus isolates (2 wild-type isolates and 1 isolate with an M217I CYP51A alteration), were analyzed. EUCAST E.Def 9.2 and CLSI M38-A2 MIC susceptibility testing was performed. ASP2397 MIC50 values (in milligrams per liter, with MIC ranges in parentheses) determined by EUCAST and CLSI were 0.5 (0.25 to 1) and 0.25 (0.06 to 0.25) against A. fumigatus CYP51A wild-type isolates and were similarly 0.5 (0.125 to >4) and 0.125 (0.06 to >4) against azole-resistant A. fumigatus isolates, respectively. These values were comparable to those for amphotericin B, which were 0.25 (0.125 to 0.5) and 0.25 (0.125 to 0.25) against wild-type isolates and 0.25 (0.125 to 1) and 0.25 (0.125 to 1) against isolates with azole resistance mechanisms, respectively. In contrast, MICs for the azole compounds were elevated and highest for itraconazole: >4 (1 to >4) and 4 (0.5 to >4) against isolates with azole resistance mechanisms compared to 0.125 (0.125 to 0.25) and 0.125 (0.06 to 0.25) against wild-type isolates, respectively. ASP2397 was active against A. terreus CYP51A wild-type isolates (MIC 0.5 to 1), whereas MICs of both azole and ASP2397 were elevated for the mutant isolate. ASP2397 displayed in vitro activity against A. fumigatus and A. terreus isolates which was independent of the presence or absence of azole target gene resistance mutations in A. fumigatus. The findings are promising at a time when azole-resistant A. fumigatus

  18. Comparison of the In Vitro Activities of Newer Triazoles and Established Antifungal Agents against Trichophyton rubrum

    PubMed Central

    Deng, Shuwen; Zhang, Chao; Seyedmousavi, Seyedmojtaba; Zhu, Shuang; Tan, Xin; Wen, Yiyang; Huang, Xin; Lei, Wenzhi; Zhou, Zhaojing; Fang, Wenjie; Shen, Shuaishuai; Deng, Danqi

    2015-01-01

    One hundred eleven clinical Trichophyton rubrum isolates were tested against 7 antifungal agents. The geometric mean MICs of all isolates were, in increasing order: terbinafine, 0.03 mg/liter; voriconazole, 0.05 mg/liter; posaconazole, 0.11 mg/liter; isavuconazole, 0.13 mg/liter; itraconazole, 0.26 mg/liter; griseofulvin, 1.65 mg/liter; and fluconazole, 2.12 mg/liter. PMID:25896691

  19. Effect of antifungal agents on lipid biosynthesis and membrane integrity in Candida albicans.

    PubMed Central

    Georgopapadakou, N H; Dix, B A; Smith, S A; Freudenberger, J; Funke, P T

    1987-01-01

    Eight antifungal agents were examined for effects on lipid biosynthesis and membrane integrity in Candida albicans. Lipids were labeled in vivo or in vitro with [14C]acetate and analyzed by thin-layer and gas chromatography. Membrane integrity was measured by a recently developed [14C]aminoisobutyric acid radiolabel release assay. The imidazole antifungal agents miconazole, econazole, clotrimazole, and ketoconazole, at concentrations inhibiting ergosterol biosynthesis (0.1 microM), decreased the ratio of unsaturated to saturated fatty acids in vivo but not in vitro. Similarly, naftifine, tolnaftate, and the azasterol A25822B, at concentrations inhibiting ergosterol biosynthesis (10, 100, and 1 microM, respectively), decreased the ratio of unsaturated to saturated fatty acids in vivo only. This suggests that the effect on fatty acids observed with ergosterol biosynthesis inhibitors may be secondary to the effect on ergosterol. With imidazoles, oleic acid antagonized inhibition of cell growth but not inhibition of ergosterol. This suggests that, with the C-14 demethylase inhibitors, decreased unsaturated fatty acids, rather than decreased ergosterol, are responsible for growth inhibition. Cerulenin, previously reported to be a potent inhibitor of both fatty acid and ergosterol biosynthesis, was found in the present study to inhibit the former (at 5 microM) but not the latter (up to 100 microM). Of the antifungal agents tested, econazole and miconazole (at 100 microM) produced complete release of [14C]aminoisobutyric acid, which is consistent with membrane damage. PMID:3551826

  20. In vitro susceptibility of Scedosporium isolates to N-acetyl-L-cysteine alone and in combination with conventional antifungal agents.

    PubMed

    Homa, Mónika; Galgóczy, László; Tóth, Eszter; Virágh, Máté; Chandrasekaran, Muthusamy; Vágvölgyi, Csaba; Papp, Tamás

    2016-10-01

    In recent years, Scedosporium species have been more commonly recognized from severe, difficult-to-treat human infections, such as upper respiratory tract and pulmonary infections. To select an appropriate therapeutic approach for these infections is challenging, because of the commonly observed resistance of the causative agents to several antifungal drugs. Therefore, to find a novel strategy for the treatment of pulmonary Scedosporium infections the in vitro antifungal effect of a mucolytic agent, N-acetyl-L-cysteine and its in vitro combinations with conventional antifungals were investigated. Synergistic and indifferent interactions were registered in 23 and 13 cases, respectively. Antagonism was not revealed between the compounds. PMID:27143635

  1. Antifungal agents. 10. New derivatives of 1-[(aryl)[4-aryl-1H-pyrrol-3-yl]methyl]-1H-imidazole, synthesis, anti-candida activity, and quantitative structure-analysis relationship studies.

    PubMed

    Tafi, Andrea; Costi, Roberta; Botta, Maurizio; Di Santo, Roberto; Corelli, Federico; Massa, Silvio; Ciacci, Andrea; Manetti, Fabrizio; Artico, Marino

    2002-06-20

    The synthesis, anti-Candida activity, and quantitative structure-activity relationship (QSAR) studies of a series of 2,4-dichlorobenzylimidazole derivatives having a phenylpyrrole moiety (related to the antibiotic pyrrolnitrin) in the alpha-position are reported. A number of substituents on the phenyl ring, ranging from hydrophobic (tert-butyl, phenyl, or 1-pyrrolyl moiety) to basic (NH(2)), polar (CF(3), CN, SCH(3), NO(2)), or hydrogen bond donors and acceptor (OH) groups, were chosen to better understand the interaction of these compounds with cytochrome P450 14-alpha-lanosterol demethylase (P450(14DM)). Finally, the triazole counterpart of one of the imidazole compounds was synthesized and tested to investigate influence of the heterocyclic ring on biological activity. The in vitro antifungal activities of the newly synthesized azoles 10p-v,x-c' were tested against Candida albicans and Candida spp. at pH 7.2 and pH 5.6. A CoMFA model, previously derived for a series of antifungal agents belonging to chemically diverse families related to bifonazole, was applied to the new products. Because the results produced by this approach were not encouraging, Catalyst software was chosen to perform a new 3D-QSAR study. Catalyst was preferred this time because of the possibility of considering each compound as a collection of energetically reasonable conformations and of considering alternative stereoisomers. The pharmacophore model developed by Catalyst, named HYPO1, showed good performances in predicting the biological activity data, although it did not exhibit an unequivocal preference for one enantiomeric series of inhibitors relative to the other. One aromatic nitrogen with a lone pair in the ring plane (mapped by all of the considered compounds) and three aromatic ring features were recognized to have pharmacophoric relevance, whereas neither hydrogen bond acceptor nor hydrophobic features were found. These findings confirmed that the key interaction of azole

  2. Antifungal susceptibility of Malassezia furfur, Malassezia sympodialis, and Malassezia globosa to azole drugs and amphotericin B evaluated using a broth microdilution method.

    PubMed

    Rojas, Florencia D; Sosa, María de los A; Fernández, Mariana S; Cattana, María E; Córdoba, Susana B; Giusiano, Gustavo E

    2014-08-01

    We studied the in vitro activity of fluconazole (FCZ), ketoconazole (KTZ), miconazole (MCZ), voriconazole (VCZ), itraconazole (ITZ) and amphotericin B (AMB) against the three major pathogenic Malassezia species, M. globosa, M. sympodialis, and M. furfur. Antifungal susceptibilities were determined using the broth microdilution method in accordance with Clinical and Laboratory Standards Institute reference document M27-A3. To support lipid-dependent yeast development, glucose, peptone, ox bile, malt extract, glycerol, and Tween supplements were added to Roswell Park Memorial Institute RPMI 1640 medium. The supplemented medium allowed good growth of all three species studied. The minimal inhibitory concentrations (MICs) were recorded after 72 h of incubation at 32ºC. The three species showed different susceptibility profiles for the drugs tested. Malassezia sympodialis was the most susceptible and M. furfur the least susceptible species. KTZ, ITZ, and VCZ were the most active drugs, showing low variability among isolates of the same species. FCZ, MCZ, and AMB showed high MICs and wide MIC ranges. Differences observed emphasize the need to accurately identify and evaluate antifungal susceptibility of Malassezia species. Further investigations and collaborative studies are essential for correlating in vitro results with clinical outcomes since the existing limited data do not allow definitive conclusions. PMID:24965946

  3. An Evaluation of Antifungal Agents for the Treatment of Fungal Contamination in Indoor Air Environments

    PubMed Central

    Rogawansamy, Senthaamarai; Gaskin, Sharyn; Taylor, Michael; Pisaniello, Dino

    2015-01-01

    Fungal contamination in indoor environments has been associated with adverse health effects for the inhabitants. Remediation of fungal contamination requires removal of the fungi present and modifying the indoor environment to become less favourable to growth.  This may include treatment of indoor environments with an antifungal agent to prevent future growth. However there are limited published data or advice on chemical agents suitable for indoor fungal remediation. The aim of this study was to assess the relative efficacies of five commercially available cleaning agents with published or anecdotal use for indoor fungal remediation. The five agents included two common multi-purpose industrial disinfectants (Cavicide® and Virkon®), 70% ethanol, vinegar (4.0%−4.2% acetic acid), and a plant-derived compound (tea tree (Melaleuca alternifolia) oil) tested in both a liquid and vapour form. Tea tree oil has recently generated interest for its antimicrobial efficacy in clinical settings, but has not been widely employed for fungal remediation. Each antifungal agent was assessed for fungal growth inhibition using a disc diffusion method against a representative species from two common fungal genera, (Aspergillus fumigatus and Penicillium chrysogenum), which were isolated from air samples and are commonly found in indoor air. Tea tree oil demonstrated the greatest inhibitory effect on the growth of both fungi, applied in either a liquid or vapour form. Cavicide® and Virkon® demonstrated similar, although less, growth inhibition of both genera. Vinegar (4.0%–4.2% acetic acid) was found to only inhibit the growth of P. chrysogenum, while 70% ethanol was found to have no inhibitory effect on the growth of either fungi. There was a notable inhibition in sporulation, distinct from growth inhibition after exposure to tea tree oil, Virkon®, Cavicide® and vinegar. Results demonstrate that common cleaning and antifungal agents differ in their capacity to inhibit the

  4. Nonplanar property study of antifungal agent tolnaftate-spectroscopic approach

    NASA Astrophysics Data System (ADS)

    Arul Dhas, D.; Hubert Joe, I.; Roy, S. D. D.; Balachandran, S.

    2011-09-01

    Vibrational analysis of the thionocarbamate fungicide tolnaftate which is antidermatophytic, antitrichophytic and antimycotic agent, primarily inhibits the ergosterol biosynthesis in the fungus, was carried out using NIR FT-Raman and FTIR spectroscopic techniques. The equilibrium geometry, various bonding features, harmonic vibrational wavenumbers and torsional potential energy surface (PES) scan studies have been computed using density functional theory method. The detailed interpretation of the vibrational spectra has been carried out with the aid of VEDA.4 program. Vibrational spectra, natural bonding orbital (NBO) analysis and optimized molecular structure show the clear evidence for electronic interaction of thionocarbamate group with aromatic ring. Predicted electronic absorption spectrum from TD-DFT calculation has been compared with the UV-vis spectrum. The Mulliken population analysis on atomic charges and the HOMO-LUMO energy were also calculated. Vibrational analysis reveals that the simultaneous IR and Raman activation of the C-C stretching mode in the phenyl and naphthalene ring provide evidence for the charge transfer interaction between the donor and acceptor groups and is responsible for its bioactivity as a fungicide.

  5. Chromatographic and electrophoretic techniques used in the analysis of triazole antifungal agents-a review.

    PubMed

    Ekiert, R J; Krzek, J; Talik, P

    2010-09-15

    Systematic review of literature coupled with integrative research of published data for triazole antifungal agents was done. The investigated literature covered chromatographic and electrophoretic methods developed in the last 10 years (2000-2009). The aim of this review was to compare different methodologies, assess preferences in the selection of analytical methods and to find still existing analytical problems. Last decade is characterized by dynamic development of instrumental methods, that results in advance and diversity of applied analytical procedures. The main focus was given to high-performance liquid chromatography (HPLC), the technique of choice in the analysis of most of pharmaceuticals. The review includes literature on 8 triazole antifungal drugs: fluconazole, itraconazole and terconazole from the first generation and posaconazole, voriconazole, ravuconazole, isavuconazole and albaconazole classified in second generation. Investigations of pharmaceutical formulations and biological samples were considered. PMID:20801303

  6. Design, synthesis, and biological evaluation of 1-[(biarylmethyl)methylamino]-2-(2,4-difluorophenyl)-3-(1H-1,2,4-triazol-1-yl)propan-2-ols as potent antifungal agents: new insights into structure-activity relationships.

    PubMed

    Guillon, Rémi; Pagniez, Fabrice; Rambaud, Charlotte; Picot, Carine; Duflos, Muriel; Logé, Cédric; Le Pape, Patrice

    2011-10-01

    We recently reported the design and synthesis of azole antifungal agents with a focus on modifications to the side chain appended to the propanol group. Herein we have identified a series of new 1-[(biarylmethyl)methylamino] derivatives with broad-spectrum antifungal activities against the most prevalent human pathogenic fungi (Candida spp. and Aspergillus fumigatus). Compounds containing a flexible benzylamine moiety were clearly shown to yield the best antifungal activities, without the need for a hydrogen-bond acceptor substituent directly attached to the para position. We were also able to determine that selected compounds are able to overcome gene overexpression and point mutations that lead to reduced susceptibility or resistance against current treatments, such as fluconazole. As the minor differences observed with small structural modifications cannot be explain with only a three-dimensional model of CYP51, adequate physicochemical parameters must be evaluated in terms of antifungal potency, bioavailability, and toxicity. Therefore, structure-activity relationship studies such as these reveal new insights for the development of future antifungal therapies. PMID:21748853

  7. Effect of treatment of palatal inflammatory papillary hyperplasia with local and systemic antifungal agents accompanied by renewal of complete dentures.

    PubMed

    Salonen, M A; Raustia, A M; Oikarinen, K S

    1996-04-01

    The aim of this study was to estimate the effect of local and systemic antifungal treatment, accompanied by renewal of complete dentures, on palatal inflammatory papillary hyperplasia (PIPH). The treatment groups consisted of 26 subjects treated with a local antifungal agent (miconazole, 2% gel) for 4 weeks and 13 subjects treated with a systemic antifungal agent (fluconazole, 50 mg) for 2 weeks (test groups). Ten subjects fitted with new complete dentures served as a control group. Variables examined before antifungal and prosthetic treatment included estimation of the size and color of the affected palatal area, measurements of the lengths of the papillae, and salivary variables. Six months after the completion of prosthetic treatment healing was determined as disappearance or marked reduction of the redness of the PIPH. Healing was more often observed in test groups (64%) than in the control group (20%) (p = 0.012). Fifty-eight per cent of the subjects treated with a local (miconazole, 2%) and 77% of those treated with a systemic (fluconazole, 50 mg) antifungal agent were healed. Even though papillary hyperplastic tissue did not disappear, the treatment of PIPH with an antifungal agent without surgery before renewal of dentures might be an alternative treatment in mild cases. PMID:8739138

  8. Plant-derived antifungal agent poacic acid targets β-1,3-glucan

    PubMed Central

    Piotrowski, Jeff S.; Okada, Hiroki; Lu, Fachuang; Li, Sheena C.; Hinchman, Li; Ranjan, Ashish; Smith, Damon L.; Higbee, Alan J.; Ulbrich, Arne; Coon, Joshua J.; Deshpande, Raamesh; Bukhman, Yury V.; McIlwain, Sean; Ong, Irene M.; Myers, Chad L.; Boone, Charles; Landick, Robert; Ralph, John; Kabbage, Mehdi; Ohya, Yoshikazu

    2015-01-01

    A rise in resistance to current antifungals necessitates strategies to identify alternative sources of effective fungicides. We report the discovery of poacic acid, a potent antifungal compound found in lignocellulosic hydrolysates of grasses. Chemical genomics using Saccharomyces cerevisiae showed that loss of cell wall synthesis and maintenance genes conferred increased sensitivity to poacic acid. Morphological analysis revealed that cells treated with poacic acid behaved similarly to cells treated with other cell wall-targeting drugs and mutants with deletions in genes involved in processes related to cell wall biogenesis. Poacic acid causes rapid cell lysis and is synergistic with caspofungin and fluconazole. The cellular target was identified; poacic acid localized to the cell wall and inhibited β-1,3-glucan synthesis in vivo and in vitro, apparently by directly binding β-1,3-glucan. Through its activity on the glucan layer, poacic acid inhibits growth of the fungi Sclerotinia sclerotiorum and Alternaria solani as well as the oomycete Phytophthora sojae. A single application of poacic acid to leaves infected with the broad-range fungal pathogen S. sclerotiorum substantially reduced lesion development. The discovery of poacic acid as a natural antifungal agent targeting β-1,3-glucan highlights the potential side use of products generated in the processing of renewable biomass toward biofuels as a source of valuable bioactive compounds and further clarifies the nature and mechanism of fermentation inhibitors found in lignocellulosic hydrolysates. PMID:25775513

  9. Synthesis and biological evaluation of new naphthalene substituted thiosemicarbazone derivatives as potent antifungal and anticancer agents.

    PubMed

    Altıntop, Mehlika Dilek; Atlı, Özlem; Ilgın, Sinem; Demirel, Rasime; Özdemir, Ahmet; Kaplancıklı, Zafer Asım

    2016-01-27

    New thiosemicarbazone derivatives (1-10) were obtained via the reaction of 4-(naphthalen-1-yl)thiosemicarbazide with fluoro-substituted aromatic aldehydes. The synthesized compounds were evaluated for their in vitro antifungal effects against pathogenic yeasts and molds using broth microdilution assay. Ames and umuC assays were carried out to determine the genotoxicity of the most effective antifungal derivatives. Furthermore, all compounds were evaluated for their cytotoxic effects on A549 human lung adenocarcinoma and NIH/3T3 mouse embryonic fibroblast cell lines using XTT test. Among these derivatives, 4-(naphthalen-1-yl)-1-(2,3-difluorobenzylidene)thiosemicarbazide (1) and 4-(naphthalen-1-yl)-1-(2,5-difluorobenzylidene)thiosemicarbazide (3) can be identified as the most promising antifungal derivatives due to their notable inhibitory effects on Candida species and no cytotoxicity against NIH/3T3 mouse embryonic fibroblast cell line. According to Ames and umuC assays, compounds 1 and 3 were classified as non-mutagenic compounds. On the other hand, 4-(naphthalen-1-yl)-1-(2,4-difluorobenzylidene)thiosemicarbazide (2) can be considered as the most promising anticancer agent against A549 cell line owing to its notable inhibitory effect on A549 cells with an IC50 value of 31.25 μg/mL when compared with cisplatin (IC50 = 16.28 μg/mL) and no cytotoxicity against NIH/3T3 cells. PMID:26706351

  10. Genomic identification of potential targets unique to Candida albicans for the discovery of antifungal agents.

    PubMed

    Tripathi, Himanshu; Luqman, Suaib; Meena, Abha; Khan, Feroz

    2014-01-01

    Despite of modern antifungal therapy, the mortality rates of invasive infection with human fungal pathogen Candida albicans are up to 40%. Studies suggest that drug resistance in the three most common species of human fungal pathogens viz., C. albicans, Aspergillus fumigatus (causing mortality rate up to 90%) and Cryptococcus neoformans (causing mortality rate up to 70%) is due to mutations in the target enzymes or high expression of drug transporter genes. Drug resistance in human fungal pathogens has led to an imperative need for the identification of new targets unique to fungal pathogens. In the present study, we have used a comparative genomics approach to find out potential target proteins unique to C. albicans, an opportunistic fungus responsible for severe infection in immune-compromised human. Interestingly, many target proteins of existing antifungal agents showed orthologs in human cells. To identify unique proteins, we have compared proteome of C. albicans [SC5314] i.e., 14,633 total proteins retrieved from the RefSeq database of NCBI, USA with proteome of human and non-pathogenic yeast Saccharomyces cerevisiae. Results showed that 4,568 proteins were identified unique to C. albicans as compared to those of human and later when these unique proteins were compared with S. cerevisiae proteome, finally 2,161 proteins were identified as unique proteins and after removing repeats total 1,618 unique proteins (42 functionally known, 1,566 hypothetical and 10 unknown) were selected as potential antifungal drug targets unique to C. albicans. PMID:24102473

  11. Lactobacillus amylovorus DSM 19280 as a novel food-grade antifungal agent for bakery products.

    PubMed

    Ryan, Liam A M; Zannini, Emanuele; Dal Bello, Fabio; Pawlowska, Agata; Koehler, Peter; Arendt, Elke K

    2011-04-29

    Mould spoilage is the main cause of substantial economic loss in bakery industry and might also cause public health problems due to the production of mycotoxins. The reduction of mould growth in bakery products is thus of crucial importance and there is great interest to develop safe and efficient strategies for this purpose. In this study Lactobacillus amylovorus DSM19280 has been shown to produce a wide spectrum of antifungal compounds active against common bread spoilage fungi. Among the indicator moulds, Aspergillus fumigatus and Fusarium culmorum were the most sensitive organisms. Several antifungal compounds were found to be present in synthetic medium inoculated with L. amylovorus DSM19280 strain, some of them being reported here for the first time. Wheat doughs fermented with L. amylovorus DSM19280 had good rheological properties and the breads thereof were of high quality as shown by rheofermentometer and texture analyser measurements. The results were compared with those obtained with a control non-antifungal L. amylovorus DSM20531(T) strain, a non-acidified and a chemically acidified dough. The quality of sourdough and bread fermented with L. amylovorus DSM 19280 was comparable to that obtained by using L. amylovorus DSM20531 (T). Additionally, breads were evaluated for the ability to retard the growth of Fusarium culmorum FST 4.05, Aspergillus niger FST4.21, Penicillium expansum FST 4.22, Penicillium roqueforti FST 4.11 and fungal flora from the bakery environment. The biological preservation of bread with L. amylovorus DSM 19280 was also compared to the most commonly used antifungal agent Calcium propionate. Breads containing sourdough fermented with L. amylovorus DSM 19280 were more effective in extending the shelf life of bread than the calcium propionate. PMID:21429613

  12. In Search of the Holy Grail of Antifungal Therapy

    PubMed Central

    Chapman, Stanley W.; Sullivan, Donna C.; Cleary, John D.

    2008-01-01

    The ideal antifungal agent remains an elusive goal for treatment of life-threatening systemic fungal infections. Such an agent would have broad antifungal activity, low rates of resistance, flexible routes of administration, few associated adverse events, and limited drug-drug interactions. Only three of the seven classes of antifungal agents currently available are suitable for treatment of systemic infection: the polyenes, the azoles, and the echinocandins. None match all the characteristics of an ideal agent, the Holy Grail of antifungal therapy. Academia and industry need to collaborate in the search for new lead antifungal compounds using traditional screening methods as well as the new pharmacogenomics methods. Enhancing efficacy and reducing toxicity of the currently available therapeutic agents is also another important avenue of study. As an example, the Mycosis Research Center at the University of Mississippi Medical Center has identified pyogenic polyenes in commercial preparations of amphotericin B deoxycholate which correlate with infusion related toxicities. A highly purified formulation of amphotericin B appears promising, with a better therapeutic index compared to its parent compound as evidenced by results of in vitro and in vivo studies reviewed in this presentation. PMID:18596853

  13. Activity of Isavuconazole and Other Azoles against Candida Clinical Isolates and Yeast Model Systems with Known Azole Resistance Mechanisms.

    PubMed

    Sanglard, Dominique; Coste, Alix T

    2016-01-01

    Isavuconazole is a novel, broad-spectrum, antifungal azole. In order to evaluate its interactions with known azole resistance mechanisms, isavuconazole susceptibility among different yeast models and clinical isolates expressing characterized azole resistance mechanisms was tested and compared to those of fluconazole, itraconazole, posaconazole, and voriconazole. Saccharomyces cerevisiae expressing the Candida albicans and C. glabrata ATP binding cassette (ABC) transporters (CDR1, CDR2, and CgCDR1), major facilitator (MDR1), and lanosterol 14-α-sterol-demethylase (ERG11) alleles with mutations were used. In addition, pairs of C. albicans and C. glabrata strains from matched clinical isolates with known azole resistance mechanisms were investigated. The expression of ABC transporters increased all azole MICs, suggesting that all azoles tested were substrates of ABC transporters. The expression of MDR1 did not increase posaconazole, itraconazole, and isavuconazole MICs. Relative increases of azole MICs (from 4- to 32-fold) were observed for fluconazole, voriconazole, and isavuconazole when at least two mutations were present in the same ERG11 allele. Upon MIC testing of azoles with clinical C. albicans and C. glabrata isolates with known resistance mechanisms, the MIC90s of C. albicans for fluconazole, voriconazole, itraconazole, posaconazole, and isavuconazole were 128, 2, 1, 0.5, and 2 μg/ml, respectively, while in C. glabrata they were 128, 2, 4, 4, and 16 μg/ml, respectively. In conclusion, the effects of azole resistance mechanisms on isavuconazole did not differ significantly from those of other azoles. Resistance mechanisms in yeasts involving ABC transporters and ERG11 decreased the activity of isavuconazole, while MDR1 had limited effect. PMID:26482310

  14. Activity of Isavuconazole and Other Azoles against Candida Clinical Isolates and Yeast Model Systems with Known Azole Resistance Mechanisms

    PubMed Central

    Coste, Alix T.

    2015-01-01

    Isavuconazole is a novel, broad-spectrum, antifungal azole. In order to evaluate its interactions with known azole resistance mechanisms, isavuconazole susceptibility among different yeast models and clinical isolates expressing characterized azole resistance mechanisms was tested and compared to those of fluconazole, itraconazole, posaconazole, and voriconazole. Saccharomyces cerevisiae expressing the Candida albicans and C. glabrata ATP binding cassette (ABC) transporters (CDR1, CDR2, and CgCDR1), major facilitator (MDR1), and lanosterol 14-α-sterol-demethylase (ERG11) alleles with mutations were used. In addition, pairs of C. albicans and C. glabrata strains from matched clinical isolates with known azole resistance mechanisms were investigated. The expression of ABC transporters increased all azole MICs, suggesting that all azoles tested were substrates of ABC transporters. The expression of MDR1 did not increase posaconazole, itraconazole, and isavuconazole MICs. Relative increases of azole MICs (from 4- to 32-fold) were observed for fluconazole, voriconazole, and isavuconazole when at least two mutations were present in the same ERG11 allele. Upon MIC testing of azoles with clinical C. albicans and C. glabrata isolates with known resistance mechanisms, the MIC90s of C. albicans for fluconazole, voriconazole, itraconazole, posaconazole, and isavuconazole were 128, 2, 1, 0.5, and 2 μg/ml, respectively, while in C. glabrata they were 128, 2, 4, 4, and 16 μg/ml, respectively. In conclusion, the effects of azole resistance mechanisms on isavuconazole did not differ significantly from those of other azoles. Resistance mechanisms in yeasts involving ABC transporters and ERG11 decreased the activity of isavuconazole, while MDR1 had limited effect. PMID:26482310

  15. In pursuit of the ideal antifungal agent for Candida infections: high-throughput screening of small molecules.

    PubMed

    Wong, Sarah S W; Samaranayake, Lakshman P; Seneviratne, Chaminda J

    2014-11-01

    Candida infections have created a great burden on the public healthcare sector. The situation is worsened by recent epidemiological changes. Furthermore, the current arsenal of antifungal agents is limited and associated with undesirable drawbacks. Therefore, new antifungal agents that surpass the existing ones are urgently needed. High-throughput screening of small molecule libraries enables rapid hit identification and, possibly, increases hit rate. Moreover, the identified hits could be associated with unrecognized or multiple drug targets, which would provide novel insights into the biological processes of the pathogen. Hence, it is proposed that high-throughput screening of small molecules is particularly important in the pursuit of the ideal antifungal agents for Candida infections. PMID:24952336

  16. In Vitro Antifungal Activities against Moulds Isolated from Dermatological Specimens

    PubMed Central

    Mohd Nizam, Tzar; Binting, Rabiatul Adawiyah AG.; Mohd Saari, Shafika; Kumar, Thivyananthini Vijaya; Muhammad, Marianayati; Satim, Hartini; Yusoff, Hamidah; Santhanam, Jacinta

    2016-01-01

    Background This study aimed to determine the minimum inhibitory concentrations (MICs) of various antifungal agents against moulds isolated from dermatological specimens. Methods We identified 29 moulds from dermatological specimens between October 2012 and March 2013 by conventional methods. We performed antifungal susceptibility testing on six antifungal agents, amphotericin B, clotrimazole, itraconazole, ketoconazole, miconazole and terbinafine, according to the Clinical and Laboratory Standards Institute guidelines contained in the M38-A2 document. Results Most antifungal agents were active against the dermatophytes, except for terbinafine against Trichophyton rubrum (geometric mean MIC, MICGM 3.17 μg/mL). The dematiaceous moulds were relatively susceptible to amphotericin B and azoles (MICGM 0.17–0.34 μg/mL), but not to terbinafine (MICGM 3.62 μg/mL). Septate hyaline moulds showed variable results between the relatively more susceptible Aspergillus spp. (MICGM 0.25–4 μg/mL) and the more resistant Fusarium spp. (MICGM 5.66–32 μg/mL). The zygomycetes were susceptible to amphotericin B (MICGM 0.5 μg/mL) and clotrimazole (MICGM 0.08 μg/mL), but not to other azoles (MICGM 2.52–4 μg/mL). Conclusion Amphotericin B and clotrimazole were the most effective antifungal agents against all moulds excepting Fusarium spp., while terbinafine was useful against dermatophytes (except T. rubrum) and Aspergillus spp. However, a larger study is required to draw more solid conclusions. PMID:27418867

  17. Identification of Aspergillus fumigatus multidrug transporter genes and their potential involvement in antifungal resistance.

    PubMed

    Meneau, Isabelle; Coste, Alix T; Sanglard, Dominique

    2016-08-01

    Aspergillus fumigatus can cause severe fatal invasive aspergillosis in immunocompromised patients but is also found in the environment. A. fumigatus infections can be treated with antifungals agents among which azole and echinocandins. Resistance to the class of azoles has been reported not only from patient samples but also from environmental samples. Azole resistance mechanisms involve for most isolates alterations at the site of the azole target (cyp51A); however, a substantial number of isolates can also exhibit non-cyp51A-mediated mechanisms.We aimed here to identify novel A. fumigatus genes involved in azole resistance. For this purpose, we designed a functional complementation system of A. fumigatus cDNAs expressed in a Saccharomyces cerevisiae isolate lacking the ATP Binding Cassette (ABC) transporter PDR5 and that was therefore more azole-susceptible than the parent wild type. Several genes were recovered including two distinct ABC transporters (atrF, atrI) and a Major Facilitator transporter (mdrA), from which atrI (Afu3g07300) and mdrA (Afu1g13800) were not yet described. atrI mediated resistance to itraconazole and voriconazole, while atrF only to voriconazole in S. cerevisiae Gene inactivation of each transporter in A. fumigatus indicated that the transporters were involved in the basal level of azole susceptibility. The expression of the transporters was addressed in clinical and environmental isolates with several azole resistance profiles. Our results show that atrI and mdrA tended to be expressed at higher levels than atrF in normal growth conditions. atrF was upregulated in 2/4 of azole-resistant environmental isolates and was the only gene with a significant association between transporter expression and azole resistance. In conclusion, this work showed the potential of complementation to identify functional transporters. The identified transporters were suggested to participate in azole resistance of A. fumigatus; however, this hypothesis will

  18. The Prevalence of Antifungal Agents Administration in Patients Undergoing Allogeneic Hematopoietic Stem Cell Transplantation: A Retrospective Study

    PubMed Central

    Kargar, Mona; Ahmadvand, Alireza; Ahmadvand, Milad; Hadjibabaie, Molouk; Gholami, Kheirollah; Khoee, Seyed Hamid; Javadi, Mohammad Reza; Ghavamzadeh, Ardeshir

    2013-01-01

    Background Invasive fungal infections (IFIs) are chief infectious complications in patients undergoing hematopoietic stem cell transplantation (HSCT). However, the diagnosis of fungal infections is difficult, and often empiric treatment initiates. Since there is no data available on the prevalence of antifungal drugs administration in allogeneic HSCT recipients in Iran, we decided to conduct this study. Methods This study was a retrospective review of records of patients who received allogeneic HSCT in the Hematology-Oncology, Bone Marrow Transplantation center at Shariati Hospital in Tehran, between August 2009 and August 2010. Results Sixty (73.1%) patients consist of 41 men (68.3%) with mean age of 26.3 (± 1.2) years received allogeneic HSCT. Patients received prophylaxis with fulconazole however; in 28 patients (46.7%) it was switched to low dose amphotericin B. Fifteen patients (25%) received treatment with antifungal agents. Amphotericin B was the empiric agent administered. In 3 patients treatment was switched to voriconazole. Neither positive culture nor direct microscopic evidence was available from the obtained specimen. Only in one patient the result of serum galactomannan assay was positive. There were no significant differences in neutropenia duration (P value: 0.54), length of hospital stay (P value: 0.27) and number of patients developed graft versus host disease (P value: 0.07) between patients received antifungal agents with those who did not receive treatment. Conclusion In this study HSCT recipients received antifungal agents for prophylaxis. Twenty five percent of patients received treatment with antifungal agents empirically. Improvement in diagnosis of these infections can be helpful and lead to targeted therapy. We suggest larger prospective trials for better assessment of antifungal agent administration. PMID:24505528

  19. First detection of Aspergillus fumigatus azole-resistant strain due to Cyp51A TR46/Y121F/T289A in an azole-naive patient in Spain.

    PubMed

    Pelaez, T; Monteiro, M C; Garcia-Rubio, R; Bouza, E; Gomez-Lopez, A; Mellado, E

    2015-07-01

    We report the first isolation of a voriconazole-resistant Aspergillus fumigatus strain harbouring the azole resistance mechanism TR46/Y121F/T289A, recovered from an azole-naive patient in Spain with chronic obstructive pulmonary disease. This new finding in Spain suggests the spread of this resistance mechanism and reinforces the need for antifungal susceptibility surveillance. PMID:26082842

  20. Quantitative and qualitative analyses of the cell death process in Candida albicans treated by antifungal agents.

    PubMed

    Kim, Kyung Sook; Kim, Young-Sun; Han, Ihn; Kim, Mi-Hyun; Jung, Min Hyung; Park, Hun-Kuk

    2011-01-01

    The death process of Candida albicans was investigated after treatment with the antifungal agents flucytosine and amphotericin B by assessing morphological and biophysical properties associated with cell death. C. albicans was treated varying time periods (from 6 to 48 hours) and examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). SEM and AFM images clearly showed changes in morphology and biophysical properties. After drug treatment, the membrane of C. albicans was perforated, deformed, and shrunken. Compared to the control, C. albicans treated with flucytosine was softer and initially showed a greater adhesive force. Conversely, C. albicans treated with amphotericin B was harder and had a lower adhesive force. In both cases, the surface roughness increased as the treatment time increased. The relationships between morphological changes and the drugs were observed by AFM clearly; the surface of C. albicans treated with flucytosine underwent membrane collapse, expansion of holes, and shrinkage, while the membranes of cells treated with amphotericin B peeled off. According to these observations, the death process of C. albicans was divided into 4 phases, CDP(0), CDP(1), CDP(2), and CDP(4), which were determined based on morphological changes. Our results could be employed to further investigate the antifungal activity of compounds derived from natural sources. PMID:22174777

  1. Repurposing the Clinically Efficacious Antifungal Agent Itraconazole as an Anticancer Chemotherapeutic.

    PubMed

    Pace, Jennifer R; DeBerardinis, Albert M; Sail, Vibhavari; Tacheva-Grigorova, Silvia K; Chan, Kelly A; Tran, Raymond; Raccuia, Daniel S; Wechsler-Reya, Robert J; Hadden, M Kyle

    2016-04-28

    Itraconazole (ITZ) is an FDA-approved member of the triazole class of antifungal agents. Two recent drug repurposing screens identified ITZ as a promising anticancer chemotherapeutic that inhibits both the angiogenesis and hedgehog (Hh) signaling pathways. We have synthesized and evaluated first- and second-generation ITZ analogues for their anti-Hh and antiangiogenic activities to probe more fully the structural requirements for these anticancer properties. Our overall results suggest that the triazole functionality is required for ITZ-mediated inhibition of angiogenesis but that it is not essential for inhibition of Hh signaling. The synthesis and evaluation of stereochemically defined des-triazole ITZ analogues also provides key information as to the optimal configuration around the dioxolane ring of the ITZ scaffold. Finally, the results from our studies suggest that two distinct cellular mechanisms of action govern the anticancer properties of the ITZ scaffold. PMID:27014922

  2. Natamycin as a selective antifungal agent in media for growth of Legionella spp.

    PubMed Central

    Edelstein, P H; Edelstein, M A

    1996-01-01

    The growth of 18 different Legionella sp. strains and 76 different yeast isolates was tested on buffered charcoal yeast extract medium supplemented with alpha-ketoglutarate (BCYE alpha medium) and with natamycin, an antifungal agent. Bacterial growth was no different on BCYE alpha medium made with or without natamycin, whereas complete inhibition of yeasts occurred in BCYE alpha medium containing 200 to 500 micrograms of natamycin per ml. Selective BCYE alpha media made with natamycin rather than anisomycin had no (formulation with vancomycin, polymyxin B, and agar) or little (formulation with cefamandole, polymyxin B, and agar) inhibitory effect on the growth of 14 different Legionella sp. bacteria. Natamycin is an inexpensive alternative to anisomycin in the formulation of selective BCYE alpha media. PMID:8748300

  3. Sparfloxacin-metal complexes as antifungal agents - Their synthesis, characterization and antimicrobial activities

    NASA Astrophysics Data System (ADS)

    Sultana, Najma; Arayne, M. Saeed; Gul, Somia; Shamim, Sana

    2010-06-01

    Metal complexes with the third-generation quinolone antibacterial agent sparfloxacin (SPFX) or 5-amino-1-cyclopropyl-7-(cis-3,5-dimethyl-1-piperazinyl)-6,8,di-fluoro-1-4-dihydro-4-oxo-3-quinocarboxylic acid have been synthesized and characterized with physicochemical and spectroscopic techniques such as TLC, IR, NMR and elemental analyses. In these complexes, sparfloxacin acts as bidentate deprotonated ligands bound to the metal through the pyridone oxygen and one carboxylate oxygen. The antimicrobial activity of these complexes has been evaluated against four Gram-positive and seven Gram-negative bacteria. Antifungal activity against five different fungi has been evaluated and compared with reference drug sparfloxacin. Fe 2+-SPFX and Cd 2+-SPFX complexes showed remarkable potency as compared to the parent drug.

  4. Lipopeptides as the Antifungal and Antibacterial Agents: Applications in Food Safety and Therapeutics

    PubMed Central

    Meena, Khem Raj; Kanwar, Shamsher S.

    2015-01-01

    A lot of crops are destroyed by the phytopathogens such as fungi, bacteria, and yeast leading to economic losses to the farmers. Members of the Bacillus genus are considered as the factories for the production of biologically active molecules that are potential inhibitors of growth of phytopathogens. Plant diseases constitute an emerging threat to global food security. Many of the currently available antimicrobial agents for agriculture are highly toxic and nonbiodegradable and thus cause extended environmental pollution. Moreover, an increasing number of phytopathogens have developed resistance to antimicrobial agents. The lipopeptides have been tried as potent versatile weapons to deal with a variety of phytopathogens. All the three families of Bacillus lipopeptides, namely, Surfactins, Iturins and Fengycins, have been explored for their antagonistic activities towards a wide range of phytopathogens including bacteria, fungi, and oomycetes. Iturin and Fengycin have antifungal activities, while Surfactin has broad range of potent antibacterial activities and this has also been used as larvicidal agent. Interestingly, lipopeptides being the molecules of biological origin are environmentally acceptable. PMID:25632392

  5. Lipopeptides as the antifungal and antibacterial agents: applications in food safety and therapeutics.

    PubMed

    Meena, Khem Raj; Kanwar, Shamsher S

    2015-01-01

    A lot of crops are destroyed by the phytopathogens such as fungi, bacteria, and yeast leading to economic losses to the farmers. Members of the Bacillus genus are considered as the factories for the production of biologically active molecules that are potential inhibitors of growth of phytopathogens. Plant diseases constitute an emerging threat to global food security. Many of the currently available antimicrobial agents for agriculture are highly toxic and nonbiodegradable and thus cause extended environmental pollution. Moreover, an increasing number of phytopathogens have developed resistance to antimicrobial agents. The lipopeptides have been tried as potent versatile weapons to deal with a variety of phytopathogens. All the three families of Bacillus lipopeptides, namely, Surfactins, Iturins and Fengycins, have been explored for their antagonistic activities towards a wide range of phytopathogens including bacteria, fungi, and oomycetes. Iturin and Fengycin have antifungal activities, while Surfactin has broad range of potent antibacterial activities and this has also been used as larvicidal agent. Interestingly, lipopeptides being the molecules of biological origin are environmentally acceptable. PMID:25632392

  6. Antifungal susceptibilities of Paecilomyces species.

    PubMed

    Aguilar, C; Pujol, I; Sala, J; Guarro, J

    1998-07-01

    The MICs and minimum fungicidal concentrations (MFCs) of amphotericin B, miconazole, itraconazole, ketoconazole, fluconazole, and flucytosine for 52 isolates of Paecilomyces species were evaluated by the broth microdilution method, largely based on the recommendations of the National Committee for Clinical Laboratory Standards (document M27-A). The fungal isolates tested included 16 P. variotii, 11 P. lilacinus, 9 P. marquandii, 6 P. fumosoroseus, 4 P. javanicus, and 2 P. viridis isolates and 1 isolate of each of the following species: P. carneus, P. farinosus, P. fulvus, and P. niveus. The MFCs and the MICs at which 90% of isolates were inhibited (MIC90s) for the six antifungal agents were remarkably high; the MIC50s indicated that amphotericin B, miconazole, itraconazole, and ketoconazole had good activities, while fluconazole and flucytosine demonstrated poor efficacy. The ranges of the MICs were generally wider and lower than those of the MFCs. There were significant susceptibility differences among the species. All species with the exception of P. variotii were highly resistant to fluconazole and flucytosine; P. variotii was susceptible to flucytosine. Amphotericin B and the rest of the azoles showed good activity against P. variotii, while all the antifungal agents assayed showed low efficacy against P. lilacinus. PMID:9660991

  7. Antifungal Susceptibilities of Paecilomyces Species

    PubMed Central

    Aguilar, C.; Pujol, I.; Sala, J.; Guarro, J.

    1998-01-01

    The MICs and minimum fungicidal concentrations (MFCs) of amphotericin B, miconazole, itraconazole, ketoconazole, fluconazole, and flucytosine for 52 isolates of Paecilomyces species were evaluated by the broth microdilution method, largely based on the recommendations of the National Committee for Clinical Laboratory Standards (document M27-A). The fungal isolates tested included 16 P. variotii, 11 P. lilacinus, 9 P. marquandii, 6 P. fumosoroseus, 4 P. javanicus, and 2 P. viridis isolates and 1 isolate of each of the following species: P. carneus, P. farinosus, P. fulvus, and P. niveus. The MFCs and the MICs at which 90% of isolates were inhibited (MIC90s) for the six antifungal agents were remarkably high; the MIC50s indicated that amphotericin B, miconazole, itraconazole, and ketoconazole had good activities, while fluconazole and flucytosine demonstrated poor efficacy. The ranges of the MICs were generally wider and lower than those of the MFCs. There were significant susceptibility differences among the species. All species with the exception of P. variotii were highly resistant to fluconazole and flucytosine; P. variotii was susceptible to flucytosine. Amphotericin B and the rest of the azoles showed good activity against P. variotii, while all the antifungal agents assayed showed low efficacy against P. lilacinus. PMID:9660991

  8. Update on antifungal drug resistance mechanisms of Aspergillus fumigatus.

    PubMed

    Chamilos, G; Kontoyiannis, D P

    2005-12-01

    Although the arsenal of agents with anti-Aspergillus activity has expanded over the last decade, mortality due to invasive aspergillosis (IA) remains unacceptably high. Aspergillus fumigatus still accounts for the majority of cases of IA; however less susceptible to antifungals non-fumigatus aspergilli began to emerge. Antifungal drug resistance of Aspergillus might partially account for treatment failures. Recent advances in our understanding of mechanisms of antifungal drug action in Aspergillus, along with the standardization of in vitro susceptibility testing methods, has brought resistance testing to the forefront of clinical mycology. In addition, molecular biology has started to shed light on the mechanisms of resistance of A. fumigatus to azoles and the echinocandins, while genome-based assays show promise for high-throughput screening for genotypic antifungal resistance. Several problems remain, however, in the study of this complex area. Large multicenter clinical studies--point prevalence or longitudinal--to capture the incidence and prevalence of antifungal resistance in A. fumigatus isolates are lacking. Correlation of in vitro susceptibility with clinical outcome and susceptibility breakpoints has not been established. In addition, the issue of cross-resistance between the newer triazoles is of concern. Furthermore, in vitro resistance testing for polyenes and echinocandins is difficult, and their mechanisms of resistance are largely unknown. This review examines challenges in the diagnosis, epidemiology, and mechanisms of antifungal drug resistance in A. fumigatus. PMID:16488654

  9. Nucleotide substitutions in the Candida albicans ERG11 gene of azole-susceptible and azole-resistant clinical isolates.

    PubMed

    Strzelczyk, Joanna Katarzyna; Slemp-Migiel, Anna; Rother, Magdalena; Gołąbek, Karolina; Wiczkowski, Andrzej

    2013-01-01

    One of the mechanisms of Candida albicans resistance to azole drugs used in antifungal therapy relies on increased expression and presence of point mutations in the ERG11 gene that encodes sterol 14α demethylase (14DM), an enzyme which is the primary target for the azole class of antifungals. The aim of the study was to analyze nucleotide substitutions in the Candida albicans ERG11 gene of azole-susceptible and azole-resistant clinical isolates. The Candida albicans isolates represented a collection of 122 strains selected from 658 strains isolated from different biological materials. Samples were obtained from hospitalized patients. Fluconazole susceptibility was tested in vitro using a microdilution assay. Candida albicans strains used in this study consisted of two groups: 61 of the isolates were susceptible to azoles and the 61 were resistant to azoles. Four overlapping regions of the ERG11 gene of the isolates of Candida albicans strains were amplified and sequenced. The MSSCP (multitemperature single strand conformation polymorphism) method was performed to select Candida albicans samples presenting genetic differences in the ERG11 gene fragments for subsequent sequence analysis. Based on the sequencing results we managed to detect 19 substitutions of nucleotides in the ERG11 gene fragments. Sequencing revealed 4 different alterations: T495A, A530C, G622A and A945C leading to changes in the corresponding amino acid sequence: D116E, K128T, V159I and E266D. The single nucleotide changes in the ERG11 gene did not affect the sensitivity of Candida albicans strains, whereas multiple nucleotide substitutions in the ERG11 gene fragments indicated a possible relation with the increase in resistance to azole drugs. PMID:24340302

  10. Improved method for azole antifungal susceptibility testing.

    PubMed Central

    Gordon, M A; Lapa, E W; Passero, P G

    1988-01-01

    A reproducible method is described for the determination of the MICs of ketoconazole, miconazole, fluconazole, and itraconazole with sharp endpoints when employed with either yeasts or molds. A semisolid medium is used with controlled pH and standardized inoculum. The time of reading results is a critical factor in the conduct of this test. The medium is simple to prepare and has a relatively long refrigerator shelf life in a user-ready state, requiring only the addition of a freshly prepared inoculum after restoration to room temperature. Images PMID:2846651

  11. Voriconazole: How to Use This Antifungal Agent and What to Expect.

    PubMed

    Malani, Anurag N; Kerr, Lisa E; Kauffman, Carol A

    2015-10-01

    Voriconazole is an important agent in the antifungal armamentarium. It is the treatment of choice for invasive aspergillosis, other hyaline molds, and many brown-black molds. It is also effective for infections caused by Candida species, including those that are fluconazole resistant, and for infections caused by the endemic mycoses, including those that occur in the central nervous system. It has the advantage of being available in both an intravenous and an oral formulation that is well absorbed. Drawbacks to the use of voriconazole are that it has unpredictable, nonlinear pharmacokinetics with extensive interpatient and intrapatient variation in serum levels. Some of the adverse effects seen with voriconazole are related to high serum concentrations, and, as a result, therapeutic drug monitoring is essential when using this agent. Drug-drug interactions are common, and possible interactions must be sought before voriconazole is prescribed. With prolonged use, newly described adverse effects, including periostitis, alopecia, and development of skin cancers, have been noted. PMID:26398543

  12. Cilofungin (LY121019), an antifungal agent with specific activity against Candida albicans and Candida tropicalis.

    PubMed Central

    Hall, G S; Myles, C; Pratt, K J; Washington, J A

    1988-01-01

    Cilofungin (LY121019) is an antifungal agent that interferes with beta-glucan synthesis in the cells walls of fungi. The activity of this agent against 256 clinical isolates of yeasts was determined. It was found to be very active in vitro against Candida albicans (MIC for 90% of isolates [MIC90], less than or equal to 0.31 microgram/ml; minimal fungicidal concentration for 90% of isolates [MFC90], less than or equal to 0.31 micrograms/ml) and C. tropicalis (MIC90, less than or equal to 0.31 microgram/ml; MFC90, less than or equal to 0.31 microgram/ml) and moderately active against Torulopsis glabrata (MIC90 and MFC90, less than or equal to 20 micrograms/ml). All C. parapsilosis, Cryptococcus, and Saccharomyces cerevisiae strains were resistant. The activity of cilofungin was affected by medium and inoculum size. Antibiotic medium no. 3 was used as the standard medium. Isolates of C. albicans and C. tropicalis demonstrated a paradoxical effect in Sabouraud dextrose broth and yeast nitrogen base broth in that growth was partially inhibited at MICs equivalent to those in antibiotic medium no. 3, but growth continued, in many instances, throughout all concentrations tested. There was decreased activity of cilofungin with inocula greater than 10(5) CFU/ml. The temperature and duration of incubation did not affect its activity. Images PMID:3058017

  13. In Vitro Activities of Five Antifungal Drugs Against Opportunistic Agents of Aspergillus Nigri Complex.

    PubMed

    Badali, Hamid; Fakhim, Hamed; Zarei, Fereshteh; Nabili, Mojtaba; Vaezi, Afsane; Poorzad, Nafiseh; Dolatabadi, Somayeh; Mirhendi, Hossein

    2016-04-01

    Black aspergilli, particularly Aspergillus niger and A. tubingensis, are the most common etiological agents of otomycosis followed by onychomycosis, pulmonary aspergillosis and aspergilloma. However, so far there is no systematic study on their antifungal susceptibility profiles. A collection of 124 clinical and environmental species of black aspergilli consisted of A. niger, A. tubingensis, A. uvarum. A. acidus and A. sydowii were verified by DNA sequencing of the partial β-tubulin gene. MICs of amphotericin B, itraconazole, voriconazole, posaconazole, and MECs of caspofungin were performed based on CLSI M38-A2. Posaconazole and caspofungin had the lowest MIC range (0.016-0.125 µg/ml and 0.008-0.031 µg/ml, respectively), followed by amphotericin B (0.25-4 µg/ml), voriconazole (0.125-16 µg/ml) and itraconazole (0.25 to >16) in an increasing order. Some strains of A. niger showed high MIC value for itraconazole and voriconazole (>16 µg/ml), in contrast only environmental isolates of A. tubingensis had high itraconazole MICs (>16 µg/ml). These results confirm that posaconazole and caspofungin are potential drugs for treatment of aspergillosis due to opportunistic agents of Aspergillus Nigri complex. However, in vivo efficacy remains to be determined. PMID:26615417

  14. QuBiLs-MAS method in early drug discovery and rational drug identification of antifungal agents.

    PubMed

    Medina Marrero, R; Marrero-Ponce, Y; Barigye, S J; Echeverría Díaz, Y; Acevedo-Barrios, R; Casañola-Martín, G M; García Bernal, M; Torrens, F; Pérez-Giménez, F

    2015-01-01

    The QuBiLs-MAS approach is used for the in silico modelling of the antifungal activity of organic molecules. To this effect, non-stochastic (NS) and simple-stochastic (SS) atom-based quadratic indices are used to codify chemical information for a comprehensive dataset of 2478 compounds having a great structural variability, with 1087 of them being antifungal agents, covering the broadest antifungal mechanisms of action known so far. The NS and SS index-based antifungal activity classification models obtained using linear discriminant analysis (LDA) yield correct classification percentages of 90.73% and 92.47%, respectively, for the training set. Additionally, these models are able to correctly classify 92.16% and 87.56% of 706 compounds in an external test set. A comparison of the statistical parameters of the QuBiLs-MAS LDA-based models with those for models reported in the literature reveals comparable to superior performance, although the latter were built over much smaller and less diverse datasets, representing fewer mechanisms of action. It may therefore be inferred that the QuBiLs-MAS method constitutes a valuable tool useful in the design and/or selection of new and broad spectrum agents against life-threatening fungal infections. PMID:26567876

  15. Non-cytotoxic antifungal agents: isolation and structures of gageopeptides A-D from a Bacillus strain 109GGC020.

    PubMed

    Tareq, Fakir Shahidullah; Lee, Min Ah; Lee, Hyi-Seung; Lee, Yeon-Ju; Lee, Jong Seok; Hasan, Choudhury M; Islam, Md Tofazzal; Shin, Hee Jae

    2014-06-18

    Antifungal resistance and toxicity problems of conventional fungicides highlighted the requirement of search for new safe antifungal agents. To comply with the requirement, we discovered four new non-cytotoxic lipopeptides, gageopeptides A-D, 1-4, from a marine-derived bacterium Bacillus subtilis. The structures and stereochemistry of gageopeptides were determined by NMR data analysis and chemical means. Gageopeptides exhibited significant antifungal activities against pathogenic fungi Rhizoctonia solani, Botrytis cinerea, and Colletotrichum acutatum with minimum inhibitory concentration (MIC) values of 0.02-0.06 μM. In addition, these lipopeptides showed significant motility inhibition and lytic activities against zoospores of the late blight pathogen Phytophthora capsici. These compounds also showed potent antimicrobial activity against Gram positive and Gram negative bacteria with MIC values of 0.04-0.08 μM. However, gageopeptides A-D did not exhibit any cytotoxicity (GI50 > 25 μM) against cancer cell lines in sulforhodamine B (SRB), 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT), and WST-1 ((4-[3-4-iodophenyl]-2-(4-nitrophenyl)-2H-5-tetrazolio)-1,3-benzene disulfonate)) assays, demonstrating that these compounds could be promising candidates for the development of non-cytotoxic antifungal agents. PMID:24857413

  16. Augmenting antifungal activity of oxidizing agent with kojic acid: Control of Penicillium strains infecting crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oxidative treatment is a strategy for preventing Penicillium contamination in foods or crops. Antifungal efficacy of oxidant [hydrogen peroxide (H2O2)], biotic effector [kojic acid (KA)] and abiotic stress (heat), alone or in combination, was investigated in Penicillium. The levels of antifungal int...

  17. Biodirected synthesis of Miconazole-conjugated bacterial silver nanoparticles and their application as antifungal agents and drug delivery vehicles.

    PubMed

    Kumar, C Ganesh; Poornachandra, Y

    2015-01-01

    The recent strategy to improve the efficacy of drugs is to combine them with metal nanoparticles for the control of microbial infections. Considering this fact, we developed a low cost and eco-friendly method for silver nanoparticles synthesis using the cell free supernatant of Delftia sp. strain KCM-006 and their application as antifungal agents and as a drug carrier. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) analysis revealed the formation of spherical and monodispersed silver nanoparticles with an average size of 9.8 nm. The synthesized nanoparticles were found to be photoluminescent, highly stable and crystalline in nature having a zeta potential of -31 mV. The silver nanoparticles exhibited very good antifungal activity against various pathogenic Candida strains. Furthermore, the efficacy of nanoparticles was increased by conjugating the antifungal drug Miconazole to silver nanoparticles which exhibited significant fungicidal activity, inhibition of ergosterol biosynthesis and biofilm inhibition by increasing ROS levels. In addition, the cell viability and immunocytochemistry analysis against different normal cell lines including Chinese hamster ovary cells (CHO), human lung cell line (MRC5) and human vascular endothelial cells (HUVEC) demonstrated that these nanoparticles were non-toxic up to a concentration of 20 μM. In conclusion, these results suggest that the synthesized nanoparticles find application as both antifungal agents and drug delivery vehicles. This is a first report on the preparation of silver nanoparticles using culture supernatant from Delftia sp. and also on the conjugation of Miconazole, an antifungal drug, to the bacterial silver nanoparticles. PMID:25460601

  18. Progressive development in experimental models of transungual drug delivery of anti-fungal agents.

    PubMed

    Thatai, P; Tiwary, A K; Sapra, B

    2016-02-01

    Pre-clinical development comprises of different procedures that relate drug discovery in the laboratory for commencement of human clinical trials. Pre-clinical studies can be designed to recognize a lead candidate from a list to develop the procedure for scale-up, to choose the unsurpassed formulation, to determine the frequency, and duration of exposure; and eventually make the foundation of the anticipated clinical trial design. The foremost aim in the pharmaceutical research and industry is the claim of drug product quality throughout a drug's life cycle. The particulars of the pre-clinical development process for different candidates may vary; however, all have some common features. Typically in vitro, in vivo or ex vivo studies are elements of pre-clinical studies. Human pharmacokinetic in vivo studies are often supposed to serve as the 'gold standard' to assess product performance. On the other hand, when this general assumption is revisited, it appears that in vitro studies are occasionally better than in vivo studies in assessing dosage forms. The present review is compendious of different such models or approaches that can be used for designing and evaluation of formulations for nail delivery with special reference to anti-fungal agents. PMID:25919363

  19. Enzymatic Activity and Susceptibility to Antifungal Agents of Brazilian Environmental Isolates of Hortaea werneckii.

    PubMed

    Formoso, Andrea; Heidrich, Daiane; Felix, Ciro Ramón; Tenório, Anne Carolyne; Leite, Belize R; Pagani, Danielle M; Ortiz-Monsalve, Santiago; Ramírez-Castrillón, Mauricio; Landell, Melissa Fontes; Scroferneker, Maria L; Valente, Patricia

    2015-12-01

    Four strains of Hortaea werneckii were isolated from different substrates in Brazil (a salt marsh macrophyte, a bromeliad and a marine zoanthid) and had their identification confirmed by sequencing of the 26S rDNA D1/D2 domain or ITS region. Most of the strains were able to express amylase, lipase, esterase, pectinase and/or cellulase, enzymes that recognize components of plant cells as substrates, but did not express albuminase, keratinase, phospholipase and DNAse, whose substrates are animal-related. Urease production was positive for all isolates, while caseinase, gelatinase and laccase production were variable among the strains. All the strains grew in media containing up to 30% NaCl. We propose that the primary substrate associated with H. werneckii is plant-related, in special in saline environments, where the fungus may live as a saprophyte and decomposer. Infection of animal-associated substrates would be secondary, with the fungus acting as an opportunistic animal pathogen. All strains were resistant to fluconazole and presented high MIC for amphotericin B, while they were susceptible to all the other antifungal agents tested. PMID:26162643

  20. Purification of an antifungal endochitinase from a potential biocontrol Agent Streptomyces griseus.

    PubMed

    Rabeeth, M; Anitha, A; Srikanth, Geetha

    2011-08-15

    Streptomyces griseus (MTCC 9723) is a chitinolytic bacterium isolated from prawn cultivated pond soil of Peddapuram Village; East Godavari District was studied in detailed. Chitinase (EC 3.2.1.14) was extracted from the culture filtrate of Streptomyces griseus and purified by ammonium sulfate precipitation, DEAE-cellulose ionexchange chromatography, Sephadex G-100 and Sephadex G-200 gel filtration chromatography. The molecular mass of the purified chitinase was estimated to be 34, 32 kDa by SDS gel electrophoresis and confirmed by activity staining with Calcofluor White M2R. Chitinase was optimally active at pH of 6.0 and at 40 degrees C. The enzyme was stable from pH 5-9 and up to 20-50 degrees C. The chitinase exhibited Km and Vmax values of 400 mg and 180 IU mL(-1) for colloidal chitin. Among the metals and inhibitors that were tested, the Hg+, Hg2+ and P-chloromercuribenzoic acid completely inhibited the chitinase activity at 1 mM concentration. The purified chitinase showed high activity on colloidal chitin, chitobiose, and chitooligosaccharide. An in vitro assay proved that the crude chitinase, actively growing cells of S. griseus having antifungal activity against all studied fungal pathogen. This result implies that characteristics of S. griseus producing endochitinase made them suitable for biotechnological purpose such as for degradation of chitin containing waste and it might be a promising biocontrol agent for plant pathogens. PMID:22545353

  1. Mechanism of Action of ME1111, a Novel Antifungal Agent for Topical Treatment of Onychomycosis.

    PubMed

    Takahata, Sho; Kubota, Natsuki; Takei-Masuda, Naomi; Yamada, Tsuyoshi; Maeda, Mari; Alshahni, Mohamed Mahdi; Abe, Shigeru; Tabata, Yuji; Maebashi, Kazunori

    2016-02-01

    Despite the existing treatment options for onychomycosis, there remains a strong demand for potent topical medications. ME1111 is a novel antifungal agent that is active against dermatophytes, has an excellent ability to penetrate human nails, and is being developed as a topical agent for onychomycosis. In the present study, we investigated its mechanism of action. Trichophyton mentagrophytes mutants with reduced susceptibility to ME1111 were selected in our laboratory, and genome sequences were determined for 3 resistant mutants. The inhibitory effect on a candidate target was evaluated by a spectrophotometric enzyme assay using mitochondrial fractions. Point mutations were introduced into candidate genes by a reverse genetics approach. Whole-genome analysis of the 3 selected mutants revealed point mutations in the structural regions of genes encoding subunits of succinate dehydrogenase (complex II). All of the laboratory-generated resistant mutants tested harbored a mutation in one of the subunits of succinate dehydrogenase (SdhB, SdhC, or SdhD). Most of the mutants showed cross-resistance to carboxin and boscalid, which are succinate dehydrogenase inhibitors. ME1111 strongly inhibited the succinate-2,6-dichlorophenolindophenol reductase reaction in Trichophyton rubrum and T. mentagrophytes (50% inhibitory concentrations [IC50s] of 0.029 and 0.025 μg/ml, respectively) but demonstrated only moderate inhibition of the same reaction in human cell lines. Furthermore, the target protein of ME1111 was confirmed by the introduction of point mutations causing the amino acid substitutions in SdhB, SdhC, and SdhD found in the laboratory-generated resistant mutants, which resulted in reduced susceptibility to ME1111. Thus, ME1111 is a novel inhibitor of the succinate dehydrogenase of Trichophyton species, and its mechanism of action indicates its selective profile. PMID:26596944

  2. Antifungal activities of diphenyl diselenide and ebselen alone and in combination with antifungal agents against Fusarium spp.

    PubMed

    Venturini, Tarcieli Pozzebon; Chassot, Francieli; Loreto, Érico Silva; Keller, Jéssica Tairine; Azevedo, Maria Izabel; Zeni, Gilson; Santurio, Janio Morais; Alves, Sydney Hartz

    2016-07-01

    Herein, we describe the in vitro activity of a combination of the organoselenium compounds diphenyl diselenide and ebselen alone and in combination with amphotericin B, caspofungin, itraconazole, and voriconazole against 25 clinical isolates of Fusarium spp. For this analysis, we used the broth microdilution method based on the M38-A2 technique and checkerboard microdilution method. Diphenyl diselenide (MIC range = 4-32 μg/ml) and ebselen (MIC range = 2-8 μg/ml) showed in vitro activity against the isolates tested. The most effective combinations were (synergism rates): ebselen + amphotericin B (88%), ebselen + voriconazole (80%), diphenyl diselenide + amphotericin B (72%), and diphenyl diselenide + voriconazole (64%). Combination with caspofungin resulted in low rates of synergism: ebselen + caspofungin, 36%, and diphenyl diselenide + caspofungin, 28%; combination with itraconazole demonstrated indifferent interactions. Antagonistic effects were not observed for any of the combinations tested. Our findings suggest that the antifungal potential of diphenyl diselenide and ebselen deserves further investigation in in vivo experimental models, especially in combination with amphotericin B and voriconazole. PMID:26773133

  3. Antifungal treatment in allergic bronchopulmonary aspergillosis with and without cystic fibrosis: a systematic review.

    PubMed

    Moreira, A S; Silva, D; Ferreira, A Reis; Delgado, L

    2014-10-01

    Allergic bronchopulmonary aspergillosis (ABPA) is a rare disease that affects patients with asthma or cystic fibrosis. Its debilitating course has led to the search for new treatments, including antifungals and monoclonal antibodies. To evaluate the efficacy and safety of antifungal treatments in patients with ABPA and either asthma or cystic fibrosis, we performed a systematic review of the literature on the effects of antifungal agents in ABPA using three biomedical databases. Quality assessment was performed using the GRADE methodology and, where appropriate, studies with comparable outcomes were pooled for meta-analysis. Thirty-eight studies - four randomized controlled trials and 34 observational studies - met the eligibility criteria. The antifungal interventions described were itraconazole, voriconazole, posaconazole, ketoconazole, natamycin, nystatin and amphotericin B. An improvement in symptoms, frequency of exacerbations and lung function was reported in most of the studies and was more common with oral azoles. Antifungals also had a positive impact on biomarkers and radiological pulmonary infiltrates, but adverse effects were also common. The quality of the evidence supporting these results was low or very low due to a shortage of controlled studies, heterogeneity between studies and potential bias. Antifungal interventions in ABPA improved patient and disease outcomes in both asthma and cystic fibrosis. However, the recommendation for their use is weak and clinicians should therefore weigh up desirable and undesirable effects on a case-by-case basis. More studies with a better methodology are needed, especially in cystic fibrosis, to increase confidence in the effects of antifungal treatments in ABPA. PMID:24809846

  4. Antifungal susceptibility profiles of 1698 yeast reference strains revealing potential emerging human pathogens.

    PubMed

    Desnos-Ollivier, Marie; Robert, Vincent; Raoux-Barbot, Dorothée; Groenewald, Marizeth; Dromer, Françoise

    2012-01-01

    New molecular identification techniques and the increased number of patients with various immune defects or underlying conditions lead to the emergence and/or the description of novel species of human and animal fungal opportunistic pathogens. Antifungal susceptibility provides important information for ecological, epidemiological and therapeutic issues. The aim of this study was to assess the potential risk of the various species based on their antifungal drug resistance, keeping in mind the methodological limitations. Antifungal susceptibility profiles to the five classes of antifungal drugs (polyens, azoles, echinocandins, allylamines and antimetabolites) were determined for 1698 yeast reference strains belonging to 992 species (634 Ascomycetes and 358 Basidiomycetes). Interestingly, geometric mean minimum inhibitory concentrations (MICs) of all antifungal drugs tested were significantly higher for Basidiomycetes compared to Ascomycetes (p<0.001). Twenty four strains belonging to 23 species of which 19 were Basidiomycetes seem to be intrinsically "resistant" to all drugs. Comparison of the antifungal susceptibility profiles of the 4240 clinical isolates and the 315 reference strains belonging to 53 shared species showed similar results. Even in the absence of demonstrated in vitro/in vivo correlation, knowing the in vitro susceptibility to systemic antifungal agents and the putative intrinsic resistance of yeast species present in the environment is important because they could become opportunistic pathogens. PMID:22396754

  5. Evaluation of Antifungal Activity and Mode of Action of New Coumarin Derivative, 7-Hydroxy-6-nitro-2H-1-benzopyran-2-one, against Aspergillus spp.

    PubMed Central

    Guerra, Felipe Queiroga Sarmento; de Araújo, Rodrigo Santos Aquino; de Sousa, Janiere Pereira; Pereira, Fillipe de Oliveira; Mendonça-Junior, Francisco J. B.; Barbosa-Filho, José M.; de Oliveira Lima, Edeltrudes

    2015-01-01

    Aspergillus spp. produce a wide variety of diseases. For the treatment of such infections, the azoles and Amphotericin B are used in various formulations. The treatment of fungal diseases is often ineffective, because of increases in azole resistance and their several associated adverse effects. To overcome these problems, natural products and their derivatives are interesting alternatives. The aim of this study was to examine the effects of coumarin derivative, 7-hydroxy-6-nitro-2H-1-benzopyran-2-one (Cou-NO2), both alone and with antifungal drugs. Its mode of action against Aspergillus spp. Cou-NO2 was tested to evaluate its effects on mycelia growth and germination of fungal conidia of Aspergillus spp. We also investigated possible Cou-NO2 action on cell walls (0.8 M sorbitol) and on Cou-NO2 to ergosterol binding in the cell membrane. The study shows that Cou-NO2 is capable of inhibiting both the mycelia growth and germination of conidia for the species tested, and that its action affects the structure of the fungal cell wall. At subinhibitory concentration, Cou-NO2 enhanced the in vitro effects of azoles. Moreover, in combination with azoles (voriconazole and itraconazole) Cou-NO2 displays an additive effect. Thus, our study supports the use of coumarin derivative 7-hydroxy-6-nitro-2H-1-benzopyran-2-one as an antifungal agent against Aspergillus species. PMID:26175794

  6. In Vitro Antifungal Activity of ME1111, a New Topical Agent for Onychomycosis, against Clinical Isolates of Dermatophytes

    PubMed Central

    Isham, N.; Long, L.

    2015-01-01

    The treatment of onychomycosis has improved considerably over the past several decades following the introduction of the oral antifungals terbinafine and itraconazole. However, these oral agents suffer from certain disadvantages, including drug interactions and potential liver toxicity. Thus, there is a need for new topical agents that are effective against onychomycosis. ME1111 is a novel selective inhibitor of succinate dehydrogenase (complex II) of dermatophyte species, whose small molecular weight enhances its ability to penetrate the nail plate. In this study, we determined the antifungal activity of ME1111 against dermatophyte strains, most of which are known to cause nail infections, as measured by the MIC (n = 400) and the minimum fungicidal concentration (MFC) (n = 300). Additionally, we examined the potential for resistance development in dermatophytes (n = 4) following repeated exposure to ME1111. Our data show that the MIC90 of ME1111 against dermatophyte strains was 0.25 μg/ml, which was equivalent to that of the comparators amorolfine and ciclopirox (0.25 and 0.5 μg/ml, respectively). ME1111 was fungicidal at clinically achievable concentrations against dermatophytes, and its MFC90s against Trichophyton rubrum and Trichophyton mentagrophytes were 8 μg/ml, comparable to those of ciclopirox. Furthermore, ME1111, as well as ciclopirox, did not induce resistance in 4 dermatophytes tested. Our studies show that ME1111 possesses potent antifungal activity and suggest that it has low potential for the development of resistance in dermatophytes. PMID:26055386

  7. In vitro antifungal activity of ME1111, a new topical agent for onychomycosis, against clinical isolates of dermatophytes.

    PubMed

    Ghannoum, M; Isham, N; Long, L

    2015-09-01

    The treatment of onychomycosis has improved considerably over the past several decades following the introduction of the oral antifungals terbinafine and itraconazole. However, these oral agents suffer from certain disadvantages, including drug interactions and potential liver toxicity. Thus, there is a need for new topical agents that are effective against onychomycosis. ME1111 is a novel selective inhibitor of succinate dehydrogenase (complex II) of dermatophyte species, whose small molecular weight enhances its ability to penetrate the nail plate. In this study, we determined the antifungal activity of ME1111 against dermatophyte strains, most of which are known to cause nail infections, as measured by the MIC (n = 400) and the minimum fungicidal concentration (MFC) (n = 300). Additionally, we examined the potential for resistance development in dermatophytes (n = 4) following repeated exposure to ME1111. Our data show that the MIC90 of ME1111 against dermatophyte strains was 0.25 μg/ml, which was equivalent to that of the comparators amorolfine and ciclopirox (0.25 and 0.5 μg/ml, respectively). ME1111 was fungicidal at clinically achievable concentrations against dermatophytes, and its MFC90s against Trichophyton rubrum and Trichophyton mentagrophytes were 8 μg/ml, comparable to those of ciclopirox. Furthermore, ME1111, as well as ciclopirox, did not induce resistance in 4 dermatophytes tested. Our studies show that ME1111 possesses potent antifungal activity and suggest that it has low potential for the development of resistance in dermatophytes. PMID:26055386

  8. Self-assembled cardanol azo derivatives as antifungal agent with chitin-binding ability.

    PubMed

    Mahata, Denial; Mandal, Santi M; Bharti, Rashmi; Gupta, Vinay Krishna; Mandal, Mahitosh; Nag, Ahindra; Nando, Golok B

    2014-08-01

    Cardanol is a non-isoprenoic phenolic lipid-mixture of distilled cashew nut shell liquid obtained from Anacardium occidentale. Herein, cardanol is purified from cashew nut shell liquid (CNSL) and synthesized to new compounds with different azo amphiphiles. These synthesized compounds are allowed to self-assembled in hydrophobic environment and checked antifungal activity against Candida albicans. Self-assembled structure of CABA showed higher antifungal activity (16μg/mL) and chitin-binding ability in comparison to CAP and CANB. Furthermore, the self-assembled azo amphiphiles are immobilized with silver ions to prepare hydrogel which showed eight folds enhanced antifungal activity. Toxicity is reduced by several folds of self-assembled or hydrogel structure in comparison to pure compounds. Thus, the self-assembled structure of amphiphiles and their hydrogels have been found to be new macromolecules of interest with potential use as antifungal drugs. PMID:24836571

  9. Consensus guidelines for optimising antifungal drug delivery and monitoring to avoid toxicity and improve outcomes in patients with haematological malignancy, 2014.

    PubMed

    Chau, M M; Kong, D C M; van Hal, S J; Urbancic, K; Trubiano, J A; Cassumbhoy, M; Wilkes, J; Cooper, C M; Roberts, J A; Marriott, D J E; Worth, L J

    2014-12-01

    Antifungal agents may be associated with significant toxicity or drug interactions leading to sub-therapeutic antifungal drug concentrations and poorer clinical outcomes for patients with haematological malignancy. These risks may be minimised by clinical assessment, laboratory monitoring, avoidance of particular drug combinations and dose modification. Specific measures, such as the optimal timing of oral drug administration in relation to meals, use of pre-hydration and electrolyte supplementation may also be required. Therapeutic drug monitoring (TDM) of antifungal agents is warranted, especially where non-compliance, non-linear pharmacokinetics, inadequate absorption, a narrow therapeutic window, suspected drug interaction or unexpected toxicity are encountered. Recommended indications for voriconazole and posaconazole TDM in the clinical management of haematology patients are provided. With emerging knowledge regarding the impact of pharmacogenomics upon metabolism of azole agents (particularly voriconazole), potential applications of pharmacogenomic evaluation to clinical practice are proposed. PMID:25482746

  10. Antifungal agent utilization evaluation in hospitalized neutropenic cancer patients at a large teaching hospital

    PubMed Central

    Vazin, Afsaneh; Davarpanah, Mohammad Ali; Ghalesoltani, Setareh

    2015-01-01

    To evaluate pattern of using of three antifungal drugs: fluconazole, amphotericin B and voriconazole, at the hematology–oncology and bone marrow transplant wards of one large teaching hospital. In a prospective cross-sectional study, we evaluated the appropriateness of using antifungal drugs in patients, using Infectious Disease Society of America (IDSA) and National Comprehensive Cancer Network (NCCN) guidelines. All the data were recorded daily by a pharmacist in a form designed by a clinical pharmacist and infectious diseases specialist, for antifungals usage, administration, and monitoring. During the study, 116 patients were enrolled. Indications of prescribing amphotericin B, fluconazole, and voriconazole were appropriate according to guidelines in 83.4%, 80.6%, and 76.9% respectively. The duration of treatments were appropriate according to guidelines in 75%, 64.5%, and 71.1% respectively. The dose of voriconazole was appropriate according to guidelines in 46.2% of patients. None of the patients received salt loading before administration of amphotericin B. The most considerable problems with the mentioned antifungals were about the indications and duration of treatment. In addition, prehydration for amphotericin B and dosage of voriconazole were not completely compatible with the mentioned guidelines. A suitable combination of controlling the use of antifungals and educational programs could be essential for improving the general process of using antifungal drugs at our hospital. PMID:26064070

  11. New N,N,N',N'-tetradentate Pyrazoly Agents: Synthesis and Evaluation of their Antifungal and Antibacterial Activities.

    PubMed

    Abrigach, Farid; Bouchal, Btissam; Riant, Olivier; Macé, Yohan; Takfaoui, Abdelilah; Radi, Smaail; Oussaid, Abdelouahad; Bellaoui, Mohammed; Touzani, Rachid

    2016-01-01

    A new library of N,N,N',N' -tetradentate pyrazoly compounds containing a pyrazole moiety was synthesized by the condensation of (3,5-dimethyl-1H-pyrazol-1-yl)methanol 2a or (1H-pyrazol-1-yl)methanol 2b with a series of primary diamines in refluxed acetonitrile for 6h. The antifungal activity against the budding yeast Saccharomyces cerevisiae, as well as the antibacterial activity against Escherichia coli of these new tetradentate ligands were studied. We found that these tetradentate ligands act specifically as antifungal agents and lack antibacterial activity. Their biological activities depend on the nature of the structure of the compounds. PMID:25985861

  12. Synthesis and biological evaluation of novel fluconazole analogues bearing 1,3,4-oxadiazole moiety as potent antifungal agents.

    PubMed

    Liao, Jun; Yang, Fan; Zhang, Lei; Chai, Xiaoyun; Zhao, Qingjie; Yu, Shichong; Zou, Yan; Meng, Qingguo; Wu, Qiuye

    2015-04-01

    A novel series of fluconazole based mimics incorporating 1,3,4-oxadiazole moiety were designed and synthesized. All the title compounds were characterized by (1)H-NMR, (13)C-NMR, and Q-TOF-MS. Preliminary results revealed that most of analogues exhibited significant antifungal activity against seven pathogenic fungi. Compounds 9g and 9k (MIC80 ≤ 0.125 μg/mL, respectively) were found more potent than the positive controls itraconazole and fluconazole as broad-spectrum antifungal agents. The observed docking results showed that the 1,3,4-oxadiazole moiety enhanced the affinity binding to the cytochrome P450 14α-demethylase (CYP51). PMID:24838380

  13. Importance of biofilm in Candida parapsilosis and evaluation of its susceptibility to antifungal agents by colorimetric method.

    PubMed

    Růzicka, F; Holá, V; Votava, M; Tejkalová, R

    2007-01-01

    The ability of C. parapsilosis (an important cause of nosocomial infections) to produce biofilm was evaluated in 32 bloodstream isolates and 85 strains isolated from skin. The biofilm formation was found in 19 (59%) blood isolates and only in 33 (39%) isolates from skin. The antifungal susceptibility was assessed for amphotericin B, itraconazole and voriconazole in planktonic and biofilm form of the 19 biofilm-positive bloodstream strains by broth microdilution method according to NCCLS standards. The method was modified by the use of resazurin as a colorimetric indicator of the metabolically active cells which makes the determination of the effect of antifungal agents easier. Biofilm forms of all strains were more resistant than their planktonic form. PMID:17702457

  14. Optimizing topical antifungal therapy for superficial cutaneous fungal infections: focus on topical naftifine for cutaneous dermatophytosis.

    PubMed

    Del Rosso, James Q; Kircik, Leon H

    2013-11-01

    Superficial cutaneous fungal infections (SCFIs) are commonly encountered in clinical practice in the United States, and comprise infections of the skin by dermatophytes and yeasts. The most common organisms causing SCFI are dermatophytes, especially Trichophyton spp. With the exception of onchomycosis and tinea capitis, most cases of SCFIs are amenable to properly selected topical antifungal therapy used over an adequate period of time.

    A variety of topical antifungal agents are available for the treatment of SCFIs, and they encompass a few major chemical classes: the polyenes (ie, nystatin), imidazoles (ie, ketoconazole, econazole, oxiconazole, etc), allylamines (ie, naftifine, terbinafine), benzylamines (ie, butenafine), and hydroxypyridones (ie, ciclopirox). The 2 major classes that represent the majority of available topical antifungal agents are the azoles and the allylamines. Overall, the allylamines are superior to the azoles in activity against dermatophytes, although both are clinically effective. The reverse is true against yeasts such as Candida spp and Malassezia spp, although topical allylamines have proven to be efficacious in some cases of tinea versicolor and cutaneous candidiasis.

    Naftifine, a topical allylamine, is fungicidal in vitro against a wide spectrum of dermatophyte fungi and has been shown to be highly effective against a variety of cutaneous dermatophyte infections. Rapid onset of clinical activity and favorable data on sustained clearance of infection have been documented with naftifine. The more recent addition of naftifine 2% cream has expanded the armamentarium, with data supporting a clinically relevant therapeutic reservoir effect after completion of therapy. PMID:24196340

  15. Analytical and Clinical Evaluation of the PathoNostics AsperGenius Assay for Detection of Invasive Aspergillosis and Resistance to Azole Antifungal Drugs during Testing of Serum Samples.

    PubMed

    White, P Lewis; Posso, Raquel B; Barnes, Rosemary A

    2015-07-01

    The commercially developed PathoNostics AsperGenius species assay is a multiplex real-time PCR capable of detecting aspergillosis and genetic markers associated with azole resistance. The assay is validated for testing bronchoalveolar lavage fluids, replacing the requirement for culture and benefiting patient management. Application of this assay to less invasive, easily obtainable samples (e.g., serum) might be advantageous. The aim of this study was to determine the analytical and clinical performance of the AsperGenius species and resistance assays for testing serum samples. For the analytical evaluations, serum samples were spiked with various concentrations of Aspergillus genomic DNA for extraction, following international recommendations. For the clinical study, 124 DNA extracts from 14 proven/probable invasive aspergillosis (IA) cases, 2 possible IA cases, and 33 controls were tested. The resistance assay was performed on Aspergillus fumigatus PCR-positive samples when a sufficient fungal burden was evident. The limits of detection of the species and resistance assays for A. fumigatus DNA were 10 and ≥75 genomes/sample, respectively. Nonreproducible detection at lower burdens was achievable for all markers. With a positivity threshold of 39 cycles, the sensitivity and specificity of the species assay were 78.6% and 100%, respectively. For 7 IA cases, at least one genetic region potentially associated with azole resistance was successfully amplified, although no resistance markers were detected in this small cohort. The AsperGenius assay provides good clinical performance with the added ability to detect azole resistance directly from noninvasive samples. While the available burden will limit application, it remains a significant advancement in the diagnosis and management of aspergillosis. PMID:25903571

  16. Analytical and Clinical Evaluation of the PathoNostics AsperGenius Assay for Detection of Invasive Aspergillosis and Resistance to Azole Antifungal Drugs during Testing of Serum Samples

    PubMed Central

    Posso, Raquel B.; Barnes, Rosemary A.

    2015-01-01

    The commercially developed PathoNostics AsperGenius species assay is a multiplex real-time PCR capable of detecting aspergillosis and genetic markers associated with azole resistance. The assay is validated for testing bronchoalveolar lavage fluids, replacing the requirement for culture and benefiting patient management. Application of this assay to less invasive, easily obtainable samples (e.g., serum) might be advantageous. The aim of this study was to determine the analytical and clinical performance of the AsperGenius species and resistance assays for testing serum samples. For the analytical evaluations, serum samples were spiked with various concentrations of Aspergillus genomic DNA for extraction, following international recommendations. For the clinical study, 124 DNA extracts from 14 proven/probable invasive aspergillosis (IA) cases, 2 possible IA cases, and 33 controls were tested. The resistance assay was performed on Aspergillus fumigatus PCR-positive samples when a sufficient fungal burden was evident. The limits of detection of the species and resistance assays for A. fumigatus DNA were 10 and ≥75 genomes/sample, respectively. Nonreproducible detection at lower burdens was achievable for all markers. With a positivity threshold of 39 cycles, the sensitivity and specificity of the species assay were 78.6% and 100%, respectively. For 7 IA cases, at least one genetic region potentially associated with azole resistance was successfully amplified, although no resistance markers were detected in this small cohort. The AsperGenius assay provides good clinical performance with the added ability to detect azole resistance directly from noninvasive samples. While the available burden will limit application, it remains a significant advancement in the diagnosis and management of aspergillosis. PMID:25903571

  17. Candida Infections, Causes, Targets, and Resistance Mechanisms: Traditional and Alternative Antifungal Agents

    PubMed Central

    Spampinato, Claudia

    2013-01-01

    The genus Candida includes about 200 different species, but only a few species are human opportunistic pathogens and cause infections when the host becomes debilitated or immunocompromised. Candida infections can be superficial or invasive. Superficial infections often affect the skin or mucous membranes and can be treated successfully with topical antifungal drugs. However, invasive fungal infections are often life-threatening, probably due to inefficient diagnostic methods and inappropriate initial antifungal therapies. Here, we briefly review our current knowledge of pathogenic species of the genus Candida and yeast infection causes and then focus on current antifungal drugs and resistance mechanisms. An overview of new therapeutic alternatives for the treatment of Candida infections is also provided. PMID:23878798

  18. Design, synthesis and evaluation of benzotriazole derivatives as novel antifungal agents.

    PubMed

    Shah, Jay J; Khedkar, Vijay; Coutinho, Evans C; Mohanraj, Krishnapriya

    2015-09-01

    Considering the need for discovery of new antifungal drugs with greater potency and broader spectrum of activity, a new series of 5-substituted benzotriazole derivatives were designed, through structure based design, as inhibitors of fungal cytochrome P450 lanosterol 14-α demethylase. These were further optimized by a combination of iterative medicinal chemistry principles and molecular docking. Based on the best docking scores, some benzotriazole derivatives were synthesized and characterized by IR, (1)H NMR and MS/MS. The molecules were evaluated for their antifungal action against Candida albicans by cup plate method and ergosterol quantification method by UV spectroscopy. Reasonably good correlation between docking scores and antifungal activity were observed. The computational predictions were in consensus with the experimental results. PMID:26117563

  19. Mitochondrial Complex I Is a Global Regulator of Secondary Metabolism, Virulence and Azole Sensitivity in Fungi

    PubMed Central

    Bromley, Mike; Johns, Anna; Davies, Emma; Fraczek, Marcin; Mabey Gilsenan, Jane; Kurbatova, Natalya; Keays, Maria; Kapushesky, Misha; Gut, Marta; Gut, Ivo; Denning, David W.; Bowyer, Paul

    2016-01-01

    Recent estimates of the global burden of fungal disease suggest that that their incidence has been drastically underestimated and that mortality may rival that of malaria or tuberculosis. Azoles are the principal class of antifungal drug and the only available oral treatment for fungal disease. Recent occurrence and increase in azole resistance is a major concern worldwide. Known azole resistance mechanisms include over—expression of efflux pumps and mutation of the gene encoding the target protein cyp51a, however, for one of the most important fungal pathogens of humans, Aspergillus fumigatus, much of the observed azole resistance does not appear to involve such mechanisms. Here we present evidence that azole resistance in A. fumigatus can arise through mutation of components of mitochondrial complex I. Gene deletions of the 29.9KD subunit of this complex are azole resistant, less virulent and exhibit dysregulation of secondary metabolite gene clusters in a manner analogous to deletion mutants of the secondary metabolism regulator, LaeA. Additionally we observe that a mutation leading to an E180D amino acid change in the 29.9 KD subunit is strongly associated with clinical azole resistant A. fumigatus isolates. Evidence presented in this paper suggests that complex I may play a role in the hypoxic response and that one possible mechanism for cell death during azole treatment is a dysfunctional hypoxic response that may be restored by dysregulation of complex I. Both deletion of the 29.9 KD subunit of complex I and azole treatment alone profoundly change expression of gene clusters involved in secondary metabolism and immunotoxin production raising potential concerns about long term azole therapy. PMID:27438017

  20. Mitochondrial Complex I Is a Global Regulator of Secondary Metabolism, Virulence and Azole Sensitivity in Fungi.

    PubMed

    Bromley, Mike; Johns, Anna; Davies, Emma; Fraczek, Marcin; Mabey Gilsenan, Jane; Kurbatova, Natalya; Keays, Maria; Kapushesky, Misha; Gut, Marta; Gut, Ivo; Denning, David W; Bowyer, Paul

    2016-01-01

    Recent estimates of the global burden of fungal disease suggest that that their incidence has been drastically underestimated and that mortality may rival that of malaria or tuberculosis. Azoles are the principal class of antifungal drug and the only available oral treatment for fungal disease. Recent occurrence and increase in azole resistance is a major concern worldwide. Known azole resistance mechanisms include over-expression of efflux pumps and mutation of the gene encoding the target protein cyp51a, however, for one of the most important fungal pathogens of humans, Aspergillus fumigatus, much of the observed azole resistance does not appear to involve such mechanisms. Here we present evidence that azole resistance in A. fumigatus can arise through mutation of components of mitochondrial complex I. Gene deletions of the 29.9KD subunit of this complex are azole resistant, less virulent and exhibit dysregulation of secondary metabolite gene clusters in a manner analogous to deletion mutants of the secondary metabolism regulator, LaeA. Additionally we observe that a mutation leading to an E180D amino acid change in the 29.9 KD subunit is strongly associated with clinical azole resistant A. fumigatus isolates. Evidence presented in this paper suggests that complex I may play a role in the hypoxic response and that one possible mechanism for cell death during azole treatment is a dysfunctional hypoxic response that may be restored by dysregulation of complex I. Both deletion of the 29.9 KD subunit of complex I and azole treatment alone profoundly change expression of gene clusters involved in secondary metabolism and immunotoxin production raising potential concerns about long term azole therapy. PMID:27438017

  1. Screening of antifungal agents using ethanol precipitation and bioautography of medicinal and food plants.

    PubMed

    Schmourlo, Gracilene; Mendonça-Filho, Ricardo R; Alviano, Celuta Sales; Costa, Sônia S

    2005-01-15

    In the search for bioactive compounds, bioautography and ethanol precipitation of macromolecules (proteins, polysaccharides, etc.) of plant aqueous extracts were associated in an antifungal screening. Thus, the supernatants, precipitates (obtained by ethanol precipitation) and aqueous extracts were investigated of medicinal and fruit bearing plants used against skin diseases by the Brazilian population. The agar diffusion and broth dilution methods were used to assess the activity against three fungi: Candida albicans, Trichophyton rubrum and Cryptococcus neoformans. The results, evaluated by the diameter of the inhibition zone of fungal growth, indicate that six plant species, among the 16 investigated, showed significant antifungal activity. The minimal inhibitory concentration (MIC) was determined on plant extracts that showed high efficacy against the tested microorganisms. The most susceptible yeast was Trichophyton rubrum and the best antifungal activity was shown by Xanthosoma sagittifolium supernatant. The bioautography was performed only for the aqueous extracts and supernatants of those plants that showed antifungal activity against Candida albicans and Cryptococcus neoformans, using n-butanol/acetic acid/water (BAW) 8:1:1 to develop silica gel TLC plates. Clear inhibition zones were observed for aqueous extracts of Schinus molle (R(f) 0.89) and Schinus terebinthifolius (R(f) 0.80) against Candida albicans, as for supernatant of Anacardium occidentale (R(f) 0.31) against Cryptococcus neoformans. The separation of macromolecules from metabolites, as in the case of Anacardium occidentale, Solanum sp. and Xanthosoma sagittifolium, enhances antifungal activity. In other cases, the antifungal activity is destroyed, as observed for Momordica charantia, Schinus molle and Schinus terebinthifolius. PMID:15619579

  2. Preliminary animal pharmacokinetics of the parenteral antifungal agent MK-0991 (L-743,872).

    PubMed

    Hajdu, R; Thompson, R; Sundelof, J G; Pelak, B A; Bouffard, F A; Dropinski, J F; Kropp, H

    1997-11-01

    MK-0991 (L-743,872) is a potent antifungal agent featuring long half-life pharmacokinetics. The pharmacokinetics of MK-0991 administered intravenously to mice, rats, rhesus monkeys, and chimpanzees is presented. Unique to MK-0991 is its consistent cross-species performance. The range of values for the pharmacokinetic parameters were as follows: clearance, 0.26 to 0.51 ml/min/kg; half-life, 5.2 to 7.6 h; and distributive volume, 0.11 to 0.27 liters/kg. The level of protein binding of MK-0991 was determined to be 96% in mouse and human serum. The compound exhibited high affinities for human serum albumin and at least two lipid components. The rationale for the selection of MK-0991 as a drug development candidate was based on its two- to threefold superior pharmacokinetic performance in chimpanzees over the performance of an otherwise equivalent analog, L-733,560. Once-daily dosing for MK-0991 is indicated by a graphical comparison of levels in the circulations of chimpanzees and mice. In a study of the pharmacokinetics of MK-0991 in mouse tissue, the organs were assayed following intraperitoneal administration. The area under the concentration-versus-time curves (AUC) segregated the tissues into three exposure categories relative to plasma. The tissues with greater exposure than that for plasma were liver (16 times), kidney (3 times), and large intestine (2 times). The exposure for small intestine, lung, and spleen were equivalent to that for plasma. Organs with lower levels of exposure were the heart (0.3 times that for plasma), thigh (0.2 times), and brain (0.06 times). Kinetically, drug was cleared more slowly from all tissues than from plasma, indicating that terminal-phase equilibrium had not been achieved by 24 h. Thus, some measure of accumulation is predicted for all tissues. Single daily doses of MK-0991 should provide adequate systemic levels of fungicidal activity as a result of its long half-life pharmacokinetics, wide distribution, and slowly

  3. Antifungal activity of Zuccagnia punctata Cav.: evidence for the mechanism of action.

    PubMed

    Svetaz, Laura; Agüero, María Belén; Alvarez, Sandra; Luna, Lorena; Feresin, Gabriela; Derita, Marcos; Tapia, Alejandro; Zacchino, Susana

    2007-08-01

    Petroleum ether and dichloromethane extracts of fruits, aerial parts and exudate of Zuccagnia punctata Cav. (Fabaceae) showed moderate antifungal activities against the yeasts C. albicans, S. cerevisiae and C. neoformans (MICs: 62.5 - 250 microg/mL) and very strong antifungal activities against the dermatophytes M. gypseum, T. rubrum and T. mentagrophytes (MICs: 8 - 16 microg/mL) thus supporting the ethnopharmacological use of this plant. Antifungal activity-directed fractionation of active extracts by using bioautography led to the isolation of 2',4'-dihydroxy-3'-methoxychalcone (1) and 2',4'-dihydroxychalcone (2) as the compounds responsible for the antifungal activity. Second-order studies included MIC (80), MIC (50) and MFC of both chalcones in an extended panel of clinical isolates of the most sensitive fungi, and also comprised a series of targeted assays. They showed that the most active chalcone 2 is fungicidal rather than fungistatic, does not disrupt the fungal membranes up to 4 x MFC and does not act by inhibiting the fungal cell wall. So, 2',4'-dihydroxychalcone would act by a different mechanism of action than the antifungal drugs in current clinical use, such as amphotericin B, azoles or echinocandins, and thus appears to be very promising as a novel antifungal agent. PMID:17628836

  4. Plant latex: a promising antifungal agent for post harvest disease control.

    PubMed

    Sibi, G; Wadhavan, Rashmi; Singh, Sneha; Shukla, Abhilasha; Dhananjaya, K; Ravikumar, K R; Mallesha, H

    2013-12-01

    Bioactive compounds from plant latex are potential source of antifungic against post harvest pathogens. Latex from a total of seven plant species was investigated for its phytochemical and antifungal properties. Six fungi namely Aspergillus fumigatus, A. niger, A. terreus, F. solani, P. digitatum and R. arrhizus were isolated from infected fruits and vegetables and tested against various solvent extracts of latex. Analysis of latex extracts with phytochemical tests showed the presence of alkaloids, flavonoids, glycosides, phenols, saponins, steroids, tannins and terpenoids. Antifungal assay revealed the potential inhibitory activity of petroleum ether extracts against the postharvest fungal isolates. Various degree of sensitivity was observed irrespective of plant species studied with A. terreus and P. digitatum as the most susceptible ones. F. solani and A. fumigatus were moderately sensitive to the latex extracts tested. Among the plants, latex of Thevetia peruviana (75.2%) and Artocarpus heterophyllus (64.8%) were having potential antifungal activity against the isolates followed by Manilkara zapota (51.1%). In conclusion, use of plant latex makes interest to control postharvest fungal diseases and is fitting well with the concept of safety for human health and environment. PMID:24506041

  5. Comparison of antifungal activities of various essential oils on the Phytophthora drechsleri, the causal agent of fruit decay

    PubMed Central

    Mohammadi, Ali; Hashemi, Maryam; Hosseini, Seyed Masoud

    2015-01-01

    Background and Objectives: The efficacy of Mentha piperita L, Zataria multiflora Boiss and Thymus vulgaris L essential oils (EOs) was evaluated for controlling the growth of Phytophthora drechsleri, the causative agent of damage to many crops that is consumed directly by humans. Materials and Methods: The EOs used in this study was purchased from Magnolia Co, Iran. The pour plate method in petri dishes containing Potato Dextrose Agar (PDA) was used to evaluate the antifungal properties of EOs. The minimal inhibitory concentrations (MIC), minimum fungicidal concentration (MFC) as well as mycelial growth inhibition (MGI) were measured. The IC50 value (the concentration inhibited 50% of the mycelium growth) was calculated by probit analysis. Results and Conclusion: The fungal growth was significantly reduced by increasing concentrations of tested EOs. The complete reduction was obtained with Shirazi thyme at all concentrations, whereas the complete reduction for peppermint and thyme was observed at 0.4% and 0.8% (v/v) concentrations, respectively. Meanwhile, the minimum inhibition was observed when 0.1% peppermint (MGI values of 9.37%) was used. The IC50, MIC and MFC values of Shirazi thyme was 0.053, 0.1% and 0.2%, respectively. Similarly, MIC and MFC values of peppermint and thyme were recorded 0.4% and 0.8%, respectively. The results obtained from this study may contribute to the development of new antifungal agents to protect the crops from this pathogenic fungus and many agricultural plant pathogens causing drastic crop losses. PMID:26644871

  6. In vitro studies of activities of some antifungal agents against Candida albicans ATCC 10231 by the turbidimetric method.

    PubMed Central

    Blanco, M T; Pérez-Giraldo, C; Blanco, J; Morán, F J; Hurtado, C; Gómez-García, A C

    1992-01-01

    Different criteria (the drug concentration which inhibited 50% of growth [IC1/2], the lowest drug concentration at which growth was just less than 30% of that in a positive control well [IC30], the visual inhibitory concentration [ICv], and the minimum fungicidal concentration [MFC]) were applied to study the effects of some antifungal agents against Candida albicans. Amphotericin B, flucytosine, and bifonazole produced total growth inhibition. Clotrimazole, itraconazole, ketoconazole, and miconazole produced partial growth inhibition. The values of IC1/2 and IC30 were similar for all agents and avoided the problems of partial inhibition; the values of ICv and MFC were higher than those of IC1/2 and IC30. PMID:1503456

  7. Efflux-Mediated Antifungal Drug Resistance†

    PubMed Central

    Cannon, Richard D.; Lamping, Erwin; Holmes, Ann R.; Niimi, Kyoko; Baret, Philippe V.; Keniya, Mikhail V.; Tanabe, Koichi; Niimi, Masakazu; Goffeau, Andre; Monk, Brian C.

    2009-01-01

    Summary: Fungi cause serious infections in the immunocompromised and debilitated, and the incidence of invasive mycoses has increased significantly over the last 3 decades. Slow diagnosis and the relatively few classes of antifungal drugs result in high attributable mortality for systemic fungal infections. Azole antifungals are commonly used for fungal infections, but azole resistance can be a problem for some patient groups. High-level, clinically significant azole resistance usually involves overexpression of plasma membrane efflux pumps belonging to the ATP-binding cassette (ABC) or the major facilitator superfamily class of transporters. The heterologous expression of efflux pumps in model systems, such Saccharomyces cerevisiae, has enabled the functional analysis of efflux pumps from a variety of fungi. Phylogenetic analysis of the ABC pleiotropic drug resistance family has provided a new view of the evolution of this important class of efflux pumps. There are several ways in which the clinical significance of efflux-mediated antifungal drug resistance can be mitigated. Alternative antifungal drugs, such as the echinocandins, that are not efflux pump substrates provide one option. Potential therapeutic approaches that could overcome azole resistance include targeting efflux pump transcriptional regulators and fungal stress response pathways, blockade of energy supply, and direct inhibition of efflux pumps. PMID:19366916

  8. Antifungal Susceptibility Testing of Ascomycetous Yeasts Isolated from Animals.

    PubMed

    Álvarez-Pérez, Sergio; García, Marta E; Peláez, Teresa; Martínez-Nevado, Eva; Blanco, José L

    2016-08-01

    Recent studies suggest that antifungal resistance in yeast isolates of veterinary origin may be an underdiagnosed threat. We tested a collection of 92 ascomycetous yeast isolates that were obtained in Spain from birds, mammals and insects for antifungal susceptibility. MICs to amphotericin B and azoles were low, and no resistant isolates were detected. Despite these results, and given the potential role of animals as reservoirs of resistant strains, continuous monitoring of antifungal susceptibility in the veterinary setting is recommended. PMID:27216048

  9. In vitro antifungal activities of luliconazole, a new topical imidazole.

    PubMed

    Koga, Hiroyasu; Nanjoh, Yasuko; Makimura, Koichi; Tsuboi, Ryoji

    2009-01-01

    Luliconazole is a topical antifungal drug newly developed in Japan. The present study compares the in vitro antifungal activity of luliconazole against clinically important dermatomycotic fungi with that of other representative antifungal drugs. The reference drugs chosen were five classes of nine topical agents, i.e., allylamine (terbinafine), thiocarbamate (liranaftate), benzylamine (butenafine), morpholine (amorolfine), and azole (ketoconazole, clotrimazole, neticonazole, miconazole and bifonazole). The minimum inhibitory concentrations (MIC) of luliconazole and the reference drugs against Trichophyton spp. (T. rubrum, T. mentagrophytes and T. tonsurans) and Candida albicans were measured by the standardized broth microdilution method. Luliconazole demonstrated greater potency against Trichophyton spp. (MIC range: agent involved in seborrhoeic dermatitis, was very low (MIC range: 0.004-0.016 microg/ml) suggesting action comparable to or stronger than that of ketoconazole. These results indicate a possible clinical role for luliconazole with its broad-spectrum antimycotic activity. PMID:19115136

  10. Fungal peritonitis in patients undergoing peritoneal dialysis (PD) in Brazil: molecular identification, biofilm production and antifungal susceptibility of the agents.

    PubMed

    Giacobino, Juliana; Montelli, Augusto Cezar; Barretti, Pasqual; Bruder-Nascimento, Ariane; Caramori, Jacqueline Teixeira; Barbosa, Luciano; Bagagli, Eduardo

    2016-10-01

    This paper presents data on fungal peritonitis (FP) in patients undergoing peritoneal dialysis (PD) at the University Hospital of Botucatu Medical School, São Paulo, Brazil. In a total of 422 patients, 30 developed FP, from which the medical records and the fungal isolates of 23 patient cases were studied. All patients presented abdominal pain, cloudy peritoneal effluent, needed hospitalization, had the catheter removed and were treated with fluconazole or fluconazole plus 5-flucitosine; six of them died due to FP. Concerning the agents, it was observed that Candida parapsilosis was the leading species (9/23), followed by Candida albicans (5/23), Candida orthopsilosis (4/23), Candida tropicalis (3/23), Candida guilliermondii (1/23), and Kodamaea ohmeri (1/23). All the isolates were susceptible to amphotericin B, voriconazole and caspofungin whereas C. albicans isolates were susceptible to all antifungals tested. Resistance to fluconazole was observed in three isolates of C. orthopsilosis, and dose-dependent susceptibility to this antifungal was observed in two isolates of C. parapsilosis and in the K. ohmeri isolate. Biofilm production estimates were high or moderate in most isolates, especially in C. albicans species, and low in C. parapsilosis species, with a marked variation among the isolates. This Brazilian study reinforces that FP in PD is caused by a diverse group of yeasts, most prevalently C. parapsilosis sensu stricto species. In addition, they present significant variation in susceptibility to antifungals and biofilm production, thus contributing to the complexity and severity of the clinical features. PMID:27143636

  11. Synthesis and biological evaluation of novel phosphoramidate derivatives of coumarin as chitin synthase inhibitors and antifungal agents.

    PubMed

    Ji, Qinggang; Ge, Zhiqiang; Ge, Zhixing; Chen, Kaizhi; Wu, Hualong; Liu, Xiaofei; Huang, Yanrong; Yuan, Lvjiang; Yang, Xiaolan; Liao, Fei

    2016-01-27

    A series of novel phosphoramidate derivatives of coumarin have been designed and synthesized as chitin synthase (CHS) inhibitors. All the synthesized compounds have been screened for their chitin synthase inhibition activity and antimicrobial activity in vitro. The bioactive assay manifested that most of the target compounds exhibited good efficacy against CHS and a variety of clinically important fungal pathogens. In particular, compound 7t with IC50 of 0.08 mM against CHS displayed stronger efficiency than the reference Polyoxin B with IC50 of 0.16 mM. In addition, the apparent Ki values of compound 7t was 0.096 mM while the Km of Chitin synthase prepared from Candida tropicalis was 3.86 mM for UDP-N-acetylglucosamine, and the result of the Ki showed that the compounds was a non-competitive inhibitor of the CHS. As far as the antifungal activity is concerned, compounds 7o, 7r and 7t were highly active against Aspergillus flavus with MIC values in the range of 1 μg/mL to 2 μg/Ml while the results of antibacterial screening showed that these compounds have negligible actions to the tested bacteria. These results indicated that the design of these compounds as antifungal agents was rational. PMID:26647304

  12. Selection of the antifungal agent decides prognosis of invasive aspergillosis: case report of a successful outcome with voriconazole.

    PubMed

    Arakawa, Hisaya; Suto, Chikako; Notani, Hiroko; Ishida, Takashi; Abe, Kayoko; Ookubo, Yasuo

    2014-02-01

    Invasive aspergillosis is a rare disease and is often misdiagnosed. The clinical course is quite aggressive and it is a potentially fatal disease. We report a case of invasive aspergillosis involving the dura mater and optic nerves which was successfully treated with voriconazole, even though the patient had residual monocular blindness. An 86-year-old Japanese man complained of developing loss of vision in his left eye while taking oral fluconazole prescribed by an otolaryngologist for mycosis of the left maxillary sinus. He was referred to our hospital. At the first visit, he already had no light perception in the left eye, with decreased ocular motility in all directions and orbital apex syndrome. His corrected distance visual acuity (CDVA) in the right eye was 20/25 with enlargement of Mariotte's blind spot. Magnetic resonance imaging revealed inflammation around both optic nerves that also involved the dura mater. His antifungal therapy was changed to intravenous voriconazole. Although his right CDVA temporarily declined to 20/50, it improved to 20/16 by 10 months after the initiation of treatment. Maxillary sinus biopsy detected Aspergillus. Invasive aspergillosis progresses rapidly and aggressively. The present case highlights the importance of early diagnosis and selection of an appropriate antifungal agent. PMID:23397120

  13. In vitro activities of five antifungal agents against 199 clinical and environmental isolates of Aspergillus flavus, an opportunistic fungal pathogen.

    PubMed

    Khodavaisy, S; Badali, H; Hashemi, S J; Aala, F; Nazeri, M; Nouripour-Sisakht, S; Sorkherizi, M S; Amirizad, K; Aslani, N; Rezaie, S

    2016-06-01

    Aspergillus flavus is the second leading cause of invasive and non-invasive aspergillosis, as well as the most common cause of fungal sinusitis, cutaneous infections, and endophthalmitis in tropical countries. Since resistance to antifungal agents has been observed in patients, susceptibility testing is helpful in defining the activity spectrum of antifungals and determining the appropriate drug for treatment. A collection of 199 clinical and environmental strains of Aspergillus flavus consisted of clinical (n=171) and environmental (n=28) were verified by DNA sequencing of the partial b-tubulin gene. MICs of amphotericin B, itraconazole, voriconazole, posaconazole, and MEC of caspofungin were determined in accordance with the Clinical and Laboratory Standards Institute M38-A2 document. Caspofungin, followed by posaconazole, exhibited the lowest minimum inhibitory concentrations (MIC). All isolates had caspofungin MEC90 (0.063μg/ml) lower than the epidemiologic cutoff values, and 3.5% of the isolates had amphotericin B MIC higher than the epidemiologic cutoff values. However, their clinical effectiveness in the treatment of A. flavus infection remains to be determined. PMID:26948143

  14. Clerodane type diterpene as a novel antifungal agent from Polyalthia longifolia var. pendula.

    PubMed

    Bhattacharya, Asish K; Chand, Hemender R; John, Jyothis; Deshpande, Mukund V

    2015-04-13

    Bioactivity-guided chemical examination of methanolic extract of leaves of Polyalthia longifolia var. pendula led to the isolation of the active constituent, a diterpene 1 which was identified as 16α-hydroxycleroda-3,13(14)Z-dien-15,16-olide on the basis of its spectral data. Among the tested strains, diterpene 1 was found to exhibit antifungal activities having MIC90 values of 50.3, 100.6 and 201.2 μM against Candida albicans NCIM3557, Cryptococcus neoformans NCIM3542 (human pathogens) and Neurospora crassa NCIM870 (saprophyte), respectively. Initial, structure-activity-relationship (SAR) data generated by synthesizing some derivatives revealed that the double bond between C3-C4 and the free hydroxyl group at C16 are crucial for the antifungal activity of the diterpene 1. The mode of action of 1 in C. albicans is due to compromised cell membrane permeability and also probably due to disruption of cell wall structures. The red blood cell haemolysis of all the compounds (1-4) did not show any significant haemolysis and was found to be less than 15% for all the compounds when tested at highest concentration, i.e. 1200 μM. Interestingly, all the tested compounds inhibited Y-H transition in dimorphic C. albicans NCIM3557 at much lower concentration than their MIC90 values. Determination of ROS generation by diterpene 1 using DCFH-DA and DHR123 (dihydrorhodamine) staining of C. albicans NCIM3557 indicated production of intracellular ROS as a mechanism of antifungal activity. PMID:25747495

  15. Experimental disseminated trichosporonosis in mice: tissue distribution and therapy with antifungal agents.

    PubMed

    Yamamoto, K; Makimura, K; Sudo, T; Shibuya, K; Uchida, K; Yamaguchi, H

    1997-01-01

    Mice treated with cyclophosphamide were infected intravenously with titrated doses of Trichosporon asahii TIMM3140 or TIMM3144. Mortality and survival time correlated with inoculum size and fungal growth was found in the lung, heart, liver, spleen, kidney and brain. Fluconazole and amphotericin B prolonged survival time and reduced the CFU in the kidney, with fluconazole being superior to amphotericin B. The serum level of (1-->3)-beta-D-glucan was reduced by antifungal therapy and correlated well with the CFU/organ in kidney, but not CFU/ml in blood. PMID:9467108

  16. Repositioning of Endonuclear Receptors Binders as Potential Antibacterial and Antifungal Agents. Eptyloxìm: A Potential and Novel Gyrase B and Cytochrome Cyp51 Inhibitor.

    PubMed

    Carrieri, Antonio; L'Abbate, Maria; Di Chicco, Mariangela; Rosato, Antonio; Carbonara, Giuseppe; Fracchiolla, Giuseppe

    2016-09-01

    A novel class of antibacterial and antifungal agents is here identified by means of dockings and virtual screening techniques. Biological data proved the initial effort, formulated on the structure similarity of nuclear receptors binders with known quinolones or thiazole derivatives, to reposition PPARs agonists as likely bacterial type II topoisomerases inhibitors. PMID:27546036

  17. Synthesis, Biological Evaluation and Molecular Docking of Certain Sulfones as Potential Nonazole Antifungal Agents.

    PubMed

    Fares, Mohamed; Said, Mohamed A; Alsherbiny, Muhammad A; Eladwy, Radwa A; Almahli, Hadia; Abdel-Aziz, Marwa M; Ghabbour, Hazem A; Eldehna, Wagdy M; Abdel-Aziz, Hatem A

    2016-01-01

    We reported herein the synthesis, antifungal activity, docking and in silico ADME prediction studies of four novel series of sulfones 6a-f, 8a-c, 10a-f and 12a-c. All the newly synthesized sulfones were tested against four strains of Candida (including fluconazole-resistant Candida), two strains of Aspergillus, two dermatophytic fungi (Trichophytons mentagrophyte and Microsporum canis) and Syncephalastrum sp. with fluconazole as a reference drug. In general, compounds 8a and 10b showed selective and potent anticandidal activity (MIC: 0.19-0.81 µM) relative to fluconazole (MIC = 1.00 µM). Furthermore, 10e and 12a elicited a remarkable and selective antifungal activity against Aspergillus sp. and the dermatophytic fungi (MIC: 0.16-0.79 µM) relative to fluconazole (MIC: 2-2.6 µM). Moreover, the docking results of the sulfones 6a, 8a, 10a and 10b at the active site of CYT P450 14α-sterol demethylase showed a comparable binding interaction (interaction Energy = -34.87 to -42.43 kcal/mol) with that of fluconazole (IE = -40.37 kcal/mol). PMID:26805791

  18. In vitro and in vivo antifungal activities of D0870, a new triazole agent.

    PubMed Central

    Yamada, H; Tsuda, T; Watanabe, T; Ohashi, M; Murakami, K; Mochizuki, H

    1993-01-01

    In vitro and in vivo antifungal activities of D0870 were evaluated in comparison with those of fluconazole. D0870, which is the R-enantiomer of ICI195,739, was found to be the mycologically active enantiomer by comparing the activities of D0870 with those of M16355 (S-enantiomer of ICI195,739). D0870 showed a broad spectrum of antifungal activity and MICs and minimum antibiotic concentrations 4- to 2,000-fold lower in synthetic amino acid medium (fungal) agar than those of fluconazole for various fungi. Although MICs of D0870 were affected by variation of the test conditions, such as type of medium, inoculum size of fungi, supplementation with fetal bovine serum, and pH of medium, they were consistently much lower than those of fluconazole under any condition. In vivo activities of D0870 in the systemic infection models with Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus in normal mice and in the mice immunosuppressed with cyclophosphamide or cortisone acetate were 2- to 7-fold and 3- to 89-fold greater than those of fluconazole, respectively. In these infection models in immunosuppressed mice, the therapeutic efficacy of D0870 was almost equivalent to that in normal mice, whereas the efficacy of fluconazole was 2- to 50-fold lower than that in normal mice. PMID:8285626

  19. Successful Treatment of Aspergillus Empyema Using Open Window Thoracostomy Salvage Treatment and the Local Administration of an Antifungal Agent.

    PubMed

    Ashizawa, Nobuyuki; Nakamura, Shigeki; Ide, Shotaro; Tashiro, Masato; Takazono, Takahiro; Imamura, Yoshifumi; Miyazaki, Taiga; Izumikawa, Koichi; Yamamoto, Yoshihiro; Yanagihara, Katsunori; Miyazaki, Yoshitsugu; Kohno, Shigeru

    2016-01-01

    A 76-year-old woman received long-term immunosuppressive treatment for collagen vascular disease-associated interstitial pneumonia. The patient developed a cavitary mass lesion in the right lower lung field, and both nontuberculous mycobacteria and Aspergillus spp. were isolated after bronchial washing. The patient underwent a right lower lobectomy but developed Aspergillus empyema. Empyema due to Aspergillus spp. is a rare and life-threatening condition; however, the standard therapeutic strategies for treating Aspergillus empyema are not clear. We herein report a case of Aspergillus empyema that was successfully treated with a combination therapy which included open-window thoracostomy and the administration of antifungal agents (systemic micafungin and local amphotericin-B). PMID:27477422

  20. Antifungal agents commonly used in the superficial and mucosal candidiasis treatment: mode of action and resistance development

    PubMed Central

    Bondaryk, Małgorzata; Kurzątkowski, Wiesław

    2013-01-01

    Recent progress in medical sciences and therapy resulted in an increased number of immunocompromised individuals. Candida albicans is the leading opportunistic fungal pathogen causing infections in humans, ranging from superficial mucosal lesions to disseminated or bloodstream candidiasis. Superficial candidiasis not always presents a risk to the life of the infected host, however it significantly lowers the quality of life. Superficial Candida infections are difficult to treat and their frequency of occurrence is currently rising. To implement successful treatment doctors should be up to date with better understanding of C. albicans resistance mechanisms. Despite high frequency of Candida infections there is a limited number of antimycotics available for therapy. This review focuses on current understanding of the mode of action and resistance mechanisms to conventional and emerging antifungal agents for treatment of superficial and mucosal candidiasis. PMID:24353489

  1. Azole Drugs Are Imported By Facilitated Diffusion in Candida albicans and Other Pathogenic Fungi

    PubMed Central

    Mansfield, Bryce E.; Oltean, Hanna N.; Oliver, Brian G.; Hoot, Samantha J.; Leyde, Sarah E.; Hedstrom, Lizbeth; White, Theodore C.

    2010-01-01

    Despite the wealth of knowledge regarding the mechanisms of action and the mechanisms of resistance to azole antifungals, very little is known about how the azoles are imported into pathogenic fungal cells. Here the in-vitro accumulation and import of Fluconazole (FLC) was examined in the pathogenic fungus, Candida albicans. In energized cells, FLC accumulation correlates inversely with expression of ATP-dependent efflux pumps. In de-energized cells, all strains accumulate FLC, suggesting that FLC import is not ATP-dependent. The kinetics of import in de-energized cells displays saturation kinetics with a Km of 0.64 uM and Vmax of 0.0056 pmol/min/108 cells, demonstrating that FLC import proceeds via facilitated diffusion through a transporter rather than passive diffusion. Other azoles inhibit FLC import on a mole/mole basis, suggesting that all azoles utilize the same facilitated diffusion mechanism. An analysis of related compounds indicates that competition for azole import depends on an aromatic ring and an imidazole or triazole ring together in one molecule. Import of FLC by facilitated diffusion is observed in other fungi, including Cryptococcus neoformans, Saccharomyces cerevisiae, and Candida krusei, indicating that the mechanism of transport is conserved among fungal species. FLC import was shown to vary among Candida albicans resistant clinical isolates, suggesting that altered facilitated diffusion may be a previously uncharacterized mechanism of resistance to azole drugs. PMID:20941354

  2. CT2108A and B: New fatty acid synthase inhibitors as antifungal agents.

    PubMed

    Laakso, Jodi A; Raulli, Robert; McElhaney-Feser, Gail E; Actor, Paul; Underiner, Ted L; Hotovec, Brian J; Mocek, Ursula; Cihlar, Ronald L; Broedel, Sheldon E

    2003-08-01

    A systematic screen for new natural products that displayed antifungal activity by inhibition of fungal fatty acid synthase (FAS) led to the discovery of two new fungal metabolites, designated CT2108A (1) and CT2108B (2). The metabolites were produced by Penicillium solitum (Westling) strain CT2108 and were classified as azaphilones. The structures of these new metabolites were determined using a variety of 1D and 2D NMR experiments, including COSY, HMQC, and HMBC. The chemical conversion of CT2108A to CT2108B was effected using WCl(6). The related metabolite, patulodin (3), was also isolated from the fermentation culture of this P. solitum isolate. Both new compounds inhibited fungal FAS, and neither was found to significantly inhibit human FAS activity. PMID:12932120

  3. 3-Bromopyruvate: a novel antifungal agent against the human pathogen Cryptococcus neoformans.

    PubMed

    Dyląg, Mariusz; Lis, Paweł; Niedźwiecka, Katarzyna; Ko, Young H; Pedersen, Peter L; Goffeau, Andre; Ułaszewski, Stanisław

    2013-05-01

    We have investigated the antifungal activity of the pyruvic acid analogue: 3-bromopyruvate (3-BP). Growth inhibition by 3-BP of 110 strains of yeast-like and filamentous fungi was tested by standard spot tests or microdilution method. The human pathogen Cryptococcus neoformans exhibited a low Minimal Inhibitory Concentration (MIC) of 0.12-0.15 mM 3-BP. The high toxicity of 3-BP toward C. neoformans correlated with high intracellular accumulation of 3-BP and also with low levels of intracellular ATP and glutathione. Weak cytotoxicity towards mammalian cells and lack of resistance conferred by the PDR (Pleiotropic Drug Resistance) network in the yeast Saccharomyces cerevisiae, are other properties of 3-BP that makes it a novel promising anticryptococcal drug. PMID:23541578

  4. First case of Tritirachium oryzae as agent of onychomycosis and its susceptibility to antifungal drugs.

    PubMed

    Naseri, Ali; Fata, Abdolmajid; Najafzadeh, Mohammad Javad

    2013-08-01

    The first case of Tritirachium oryzae isolated from an Iranian patient is reported. A 44-year-old woman with a lesion in her fingernail was examined for onychomycosis. Direct microscopic examination of the nail clippings revealed fungal filaments and inoculation of portions of the nail clippings on cultures media yielded T. oryzae after 8 days. The isolate was identified as Tritirachium spp. on the basis of gross morphological characteristics of the fungal colony and microscopic characterization of slide cultures. The diagnosis of T. oryzae was confirmed by PCR sequencing of the internal transcribed spacer domain of the rDNA gene. In vitro antifungal susceptibility test demonstrated that the fungus was susceptible to itraconazole and posaconazole. The patient was treated with oral itraconazole. PMID:23591624

  5. Synthesis of new pyrazolyl-2, 4-thiazolidinediones as antibacterial and antifungal agents

    PubMed Central

    2011-01-01

    Background Thiazolidine-2, 4-diones (TZDs) have become a pharmacologically important class of heterocyclic compounds since their introduction in the form of glitazones into the clinical use for the treatment of type 2 diabetes. TZDs lower the plasma glucose levels by acting as ligands for gamma peroxisome proliferators-activated receptors. In addition, this class of heterocyclic compounds possesses various other biological activities such as antihyperglycemic, antimicrobial, anti-inflammatory, anticonvulsant, insecticidal, etc. TZDs are also known for lowering the blood pressure thereby reducing the chances of heart failure and micro-albuminuria in the patients with type 2 diabetes. Results We have described herein the synthesis of three series of compounds, namely, ethyl 2-((Z)-5-((3-aryl-1-phenyl-1H-pyrazol-4-yl)methylene)-2, 4-dioxothiazolidin-3-yl)acetates (4), methyl 2-((Z)-5-((3-aryl-1-phenyl-1H-pyrazol-4-yl)methylene)-2, 4-dioxothiazolidin-3-yl)acetates (5), and 2-((Z)-5-((3-aryl-1-phenyl-1H-pyrazol-4-yl)methylene)-2, 4-dioxothiazolidin-3-yl)acetic acids (6). The compounds 4 and 5 were synthesized by Knoevenagel condensation between 3-aryl-1-phenyl-1H-pyrazole-4-carbaldehydes (1) and ethyl/methyl 2-(2, 4-dioxothiazolidin-3-yl)acetates (3, 2) in alcohol using piperidine as a catalyst. The resultant compounds 4 and 5 having ester functionality were subjected to acidic hydrolysis to obtain 6. All the new compounds were tested for their in vitro antibacterial and antifungal activity. Conclusions Knoevenagel condensation approach has offered an easy access to new compounds 4-6. Antimicrobial evaluation of the compounds has shown that some of the compounds are associated with remarkable antifungal activity. In case of antibacterial activity, these were found to be effective against Gram-positive bacteria. However, none of the compounds were found to be effective against Gram-negative bacteria. PMID:22373217

  6. The Aspergillus fumigatus Damage Resistance Protein Family Coordinately Regulates Ergosterol Biosynthesis and Azole Susceptibility

    PubMed Central

    Song, Jinxing; Zhai, Pengfei; Zhang, Yuanwei; Zhang, Caiyun; Sang, Hong; Han, Guanzhu; Keller, Nancy P.

    2016-01-01

    ABSTRACT Ergosterol is a major and specific component of the fungal plasma membrane, and thus, the cytochrome P450 enzymes (Erg proteins) that catalyze ergosterol synthesis have been selected as valuable targets of azole antifungals. However, the opportunistic pathogen Aspergillus fumigatus has developed worldwide resistance to azoles largely through mutations in the cytochrome P450 enzyme Cyp51 (Erg11). In this study, we demonstrate that a cytochrome b5-like heme-binding damage resistance protein (Dap) family, comprised of DapA, DapB, and DapC, coordinately regulates the functionality of cytochrome P450 enzymes Erg5 and Erg11 and oppositely affects susceptibility to azoles. The expression of all three genes is induced in an azole concentration-dependent way, and the decreased susceptibility to azoles requires DapA stabilization of cytochrome P450 protein activity. In contrast, overexpression of DapB and DapC causes dysfunction of Erg5 and Erg11, resulting in abnormal accumulation of sterol intermediates and further accentuating the sensitivity of ΔdapA strains to azoles. The results of exogenous-hemin rescue and heme-binding-site mutagenesis experiments demonstrate that the heme binding of DapA contributes the decreased azole susceptibility, while DapB and -C are capable of reducing the activities of Erg5 and Erg11 through depletion of heme. In vivo data demonstrate that inactivated DapA combined with activated DapB yields an A. fumigatus mutant that is easily treatable with azoles in an immunocompromised mouse model of invasive pulmonary aspergillosis. Compared to the single Dap proteins found in Saccharomyces cerevisiae and Schizosaccharomyces pombe, we suggest that this complex Dap family regulatory system emerged during the evolution of fungi as an adaptive means to regulate ergosterol synthesis in response to environmental stimuli. PMID:26908577

  7. Burkholderia terrae BS001 migrates proficiently with diverse fungal hosts through soil and provides protection from antifungal agents

    PubMed Central

    Nazir, Rashid; Tazetdinova, Diana I.; van Elsas, Jan Dirk

    2014-01-01

    Soil bacteria can benefit from co-occurring soil fungi in respect of the acquisition of carbonaceous nutrients released by fungal hyphae and the access to novel territories in soil. Here, we investigated the capacity of the mycosphere-isolated bacterium Burkholderia terrae BS001 to comigrate through soil along with hyphae of the soil fungi Trichoderma asperellum, Rhizoctonia solani, Fusarium oxysporum, F. oxysporum pv lini, Coniochaeta ligniaria, Phanerochaete velutina, and Phallus impudicus. We used Lyophyllum sp. strain Karsten as the reference migration-inciting fungus. Bacterial migration through presterilized soil on the extending fungal hyphae was detected with six of the seven test fungi, with only Phallus impudicus not showing any bacterial transport. Much like with Lyophyllum sp. strain Karsten, intermediate (106–108 CFU g-1 dry soil) to high (>108 CFU g-1 dry soil) strain BS001 cell population sizes were found at the hyphal migration fronts of four fungi, i.e., T. asperellum, Rhizoctonia solani, F. oxysporum and F. oxysporum pv lini, whereas for two fungi, Coniochaeta ligniaria and Phanerochaete velutina, the migration responses were retarded and population sizes were lower (103–106 CFU g-1 dry soil). Consistent with previous data obtained with the reference fungus, migration with the migration-inciting fungi occurred only in the direction of the hyphal growth front. Remarkably, Burkholderia terrae BS001 provided protection from several antifungal agents to the canonical host Lyophyllum sp. strain Karsten. Specifically, this host was protected from Pseudomonas fluorescens strain CHA0 metabolites, as well as from the anti-fungal agent cycloheximide. Similar protection by strain BS001was observed for T. asperellum, and, to a lower extent, F. oxysporum and Rhizoctonia solani. The protective effect may be related to the consistent occurrence of biofilm-like cell layers or agglomerates at the surfaces of the protected fungi. The current study represents

  8. Pseudomonas stutzeri YPL-1 Genetic Transformation and Antifungal Mechanism against Fusarium solani, an Agent of Plant Root Rot

    PubMed Central

    Lim, Ho-Seong; Kim, Yong-Su; Kim, Sang-Dal

    1991-01-01

    An actively antagonistic bacterium that could be used as a biocontrol agent against Fusarium solani, which causes root rots with considerable losses in many important crops, was isolated from a ginseng rhizosphere and identified as a strain of Pseudomonas stutzeri. In several biochemical tests with culture filtrates of P. stutzeri YPL-1 and in mutational analyses of antifungal activities of reinforced or defective mutants, we found that the anti-F. solani mechanism of the bacterium may involve a lytic enzyme rather than a toxic substance or antibiotic. P. stutzeri YPL-1 produced extracellular chitinase and laminarinase when grown on different polymers such as chitin, laminarin, or F. solani mycelium. These lytic extracellular enzymes markedly inhibited mycelial growth rather than spore germination and also caused lysis of F. solani mycelia and germ tubes. Scanning electron microscopy revealed degradation of the F. solani mycelium. Abnormal hyphal swelling and retreating were caused by the lysing agents from P. stutzeri YPL-1, and a penetration hole was formed on the hyphae in the region of interaction with the bacterium; the walls of this region were rapidly lysed, causing leakage of protoplasm. Genetically bred P. stutzeri YPL-1 was obtained by transformation of the bacterium with a broad-host-range vector, pKT230. Also, the best conditions for the transformation were investigated. Images PMID:16348417

  9. Identification and Evaluation of Novel Acetolactate Synthase Inhibitors as Antifungal Agents

    PubMed Central

    Richie, Daryl L.; Thompson, Katherine V.; Studer, Christian; Prindle, Vivian C.; Aust, Thomas; Riedl, Ralph; Estoppey, David; Tao, Jianshi; Sexton, Jessica A.; Zabawa, Thomas; Drumm, Joseph; Cotesta, Simona; Eichenberger, Jürg; Schuierer, Sven; Hartmann, Nicole; Movva, N. Rao; Tallarico, John A.

    2013-01-01

    High-throughput phenotypic screening against the yeast Saccharomyces cerevisiae revealed a series of triazolopyrimidine-sulfonamide compounds with broad-spectrum antifungal activity, no significant cytotoxicity, and low protein binding. To elucidate the target of this series, we have applied a chemogenomic profiling approach using the S. cerevisiae deletion collection. All compounds of the series yielded highly similar profiles that suggested acetolactate synthase (Ilv2p, which catalyzes the first common step in branched-chain amino acid biosynthesis) as a possible target. The high correlation with profiles of known Ilv2p inhibitors like chlorimuron-ethyl provided further evidence for a similar mechanism of action. Genome-wide mutagenesis in S. cerevisiae identified 13 resistant clones with 3 different mutations in the catalytic subunit of acetolactate synthase that also conferred cross-resistance to established Ilv2p inhibitors. Mapping of the mutations into the published Ilv2p crystal structure outlined the chlorimuron-ethyl binding cavity, and it was possible to dock the triazolopyrimidine-sulfonamide compound into this pocket in silico. However, fungal growth inhibition could be bypassed through supplementation with exogenous branched-chain amino acids or by the addition of serum to the medium in all of the fungal organisms tested except for Aspergillus fumigatus. Thus, these data support the identification of the triazolopyrimidine-sulfonamide compounds as inhibitors of acetolactate synthase but suggest that targeting may be compromised due to the possibility of nutrient bypass in vivo. PMID:23478965

  10. Reversal of efflux mediated antifungal resistance underlies synergistic activity of two monoterpenes with fluconazole.

    PubMed

    Ahmad, Aijaz; Khan, Amber; Manzoor, Nikhat

    2013-01-23

    Thymol (THY) and carvacrol (CARV), the principal chemical components of thyme oil have long been known for their wide use in medicine due to antimicrobial and disinfectant properties. This study, however, draws attention to a possible synergistic antifungal effect of these monoterpenes with azole antimycotic-fluconazole. Resistance to azoles in Candida albicans involves over-expression of efflux-pump genes MDR1, CDR1, CDR2 or mutations and over-expression of target gene ERG11. The inhibition of drug efflux pumps is considered a feasible strategy to overcome clinical antifungal resistance. To put forward this approach, we investigated the combination effects of these monoterpenes and FLC against 38 clinically obtained FLC-sensitive, and eleven FLC-resistant Candida isolates. Synergism was observed with combinations of THY-FLC and CARV-FLC evaluated by checkerboard microdilution method and nature of the interactions was calculated by FICI. In addition, antifungal activity was assessed using agar-diffusion and time-kill curves. The drug efflux activity was determined using two dyes, Rhodamine6G (R6G) and fluorescent Hoechst 33342. No significant differences were observed in dye uptakes between FLC-susceptible and resistant isolates, incubated in glucose free buffer. However, a significantly higher efflux was recorded in FLC-resistant isolates when glucose was added. Both monoterpenes inhibited efflux by 70-90%, showing their high potency to block drug transporter pumps. Significant differences, in the expression levels of CDR1 and MDR1, induced by monoterpenes revealed reversal of FLC-resistance. The selectively fungicidal characteristics and ability to restore FLC susceptibility in resistant isolates signify a promising candidature of THY and CARV as antifungal agents in combinational treatments for candidiasis. PMID:23111348

  11. Azole-resistant Candida albicans from a wild Brazilian porcupine (Coendou prehensilis): a sign of an environmental imbalance?

    PubMed

    Castelo-Branco, D S C M; Brilhante, R S N; Paiva, M A N; Teixeira, C E C; Caetano, E P; Ribeiro, J F; Cordeiro, R A; Sidrim, J J C; Monteiro, A J; Rocha, M F G

    2013-07-01

    This study aimed at evaluating the in vitro antifungal susceptibility of Candida albicans isolates obtained during necropsy of a wild Brazilian porcupine and the mechanism of azole resistance. Initially, we investigated the in vitro susceptibility of the three isolates to amphotericin B, caspofungin, fluconazole, itraconazole, ketoconazole and voriconazole. Afterwards, three sub-inhibitory concentrations (47, 21 and 12 mg/l) of promethazine, an efflux pump inhibitor, were tested in combination with the antifungal drugs in order to evaluate the role of these pumps in the development of antifungal resistance. In addition, the three isolates were submitted to RAPD-PCR and M13-fingerprinting analyses. The minimum inhibitory concentrations (MICs) obtained with the isolates were 1, 0.03125, 250, 125, 8 and 250 mg/l for amphotericin B, caspofungin, fluconazole, itraconazole, ketoconazole and voriconazole, respectively, and the isolates were found to be resistant to all tested azoles. The addition of the three subinhibitory concentrations of promethazine resulted in statistically significant (P < 0.05) reductions in the MICs for all tested drugs, with decreases to azoles being statistically greater than those for amphotericin B and caspofungin (P < 0.05). The molecular analyses showed a genetic similarity among the three tested isolates, suggesting the occurrence of candidemia in the studied animal. These findings highlight the importance of monitoring antifungal susceptibility of Candida spp. from veterinary sources, especially as they may indicate the occurrence of primary azole resistance even in wild animals. PMID:23286353

  12. An Antifungal Benzimidazole Derivative Inhibits Ergosterol Biosynthesis and Reveals Novel Sterols

    PubMed Central

    Keller, Petra; Müller, Christoph; Engelhardt, Isabel; Hiller, Ekkehard; Lemuth, Karin; Eickhoff, Holger; Wiesmüller, Karl-Heinz; Burger-Kentischer, Anke; Bracher, Franz

    2015-01-01

    Fungal infections are a leading cause of morbidity and death for hospitalized patients, mainly because they remain difficult to diagnose and to treat. Diseases range from widespread superficial infections such as vulvovaginal infections to life-threatening systemic candidiasis. For systemic mycoses, only a restricted arsenal of antifungal agents is available. Commonly used classes of antifungal compounds include azoles, polyenes, and echinocandins. Due to emerging resistance to standard therapies, significant side effects, and high costs for several antifungals, there is a need for new antifungals in the clinic. In order to expand the arsenal of compounds with antifungal activity, we previously screened a compound library using a cell-based screening assay. A set of novel benzimidazole derivatives, including (S)-2-(1-aminoisobutyl)-1-(3-chlorobenzyl)benzimidazole (EMC120B12), showed high antifungal activity against several species of pathogenic yeasts, including Candida glabrata and Candida krusei (species that are highly resistant to antifungals). In this study, comparative analysis of EMC120B12 versus fluconazole and nocodazole, using transcriptional profiling and sterol analysis, strongly suggested that EMC120B12 targets Erg11p in the ergosterol biosynthesis pathway and not microtubules, like other benzimidazoles. In addition to the marker sterol 14-methylergosta-8,24(28)-dien-3β,6α-diol, indicating Erg11p inhibition, related sterols that were hitherto unknown accumulated in the cells during EMC120B12 treatment. The novel sterols have a 3β,6α-diol structure. In addition to the identification of novel sterols, this is the first time that a benzimidazole structure has been shown to result in a block of the ergosterol pathway. PMID:26248360

  13. An Antifungal Benzimidazole Derivative Inhibits Ergosterol Biosynthesis and Reveals Novel Sterols.

    PubMed

    Keller, Petra; Müller, Christoph; Engelhardt, Isabel; Hiller, Ekkehard; Lemuth, Karin; Eickhoff, Holger; Wiesmüller, Karl-Heinz; Burger-Kentischer, Anke; Bracher, Franz; Rupp, Steffen

    2015-10-01

    Fungal infections are a leading cause of morbidity and death for hospitalized patients, mainly because they remain difficult to diagnose and to treat. Diseases range from widespread superficial infections such as vulvovaginal infections to life-threatening systemic candidiasis. For systemic mycoses, only a restricted arsenal of antifungal agents is available. Commonly used classes of antifungal compounds include azoles, polyenes, and echinocandins. Due to emerging resistance to standard therapies, significant side effects, and high costs for several antifungals, there is a need for new antifungals in the clinic. In order to expand the arsenal of compounds with antifungal activity, we previously screened a compound library using a cell-based screening assay. A set of novel benzimidazole derivatives, including (S)-2-(1-aminoisobutyl)-1-(3-chlorobenzyl)benzimidazole (EMC120B12), showed high antifungal activity against several species of pathogenic yeasts, including Candida glabrata and Candida krusei (species that are highly resistant to antifungals). In this study, comparative analysis of EMC120B12 versus fluconazole and nocodazole, using transcriptional profiling and sterol analysis, strongly suggested that EMC120B12 targets Erg11p in the ergosterol biosynthesis pathway and not microtubules, like other benzimidazoles. In addition to the marker sterol 14-methylergosta-8,24(28)-dien-3β,6α-diol, indicating Erg11p inhibition, related sterols that were hitherto unknown accumulated in the cells during EMC120B12 treatment. The novel sterols have a 3β,6α-diol structure. In addition to the identification of novel sterols, this is the first time that a benzimidazole structure has been shown to result in a block of the ergosterol pathway. PMID:26248360

  14. Emerging aspergillosis by azole-resistant Aspergillus fumigatus at an intensive care unit in the Netherlands, 2010 to 2013.

    PubMed

    van Paassen, Judith; Russcher, Anne; In 't Veld-van Wingerden, Astrid Wm; Verweij, Paul E; Kuijper, Eduard J

    2016-07-28

    The prevalence of invasive aspergillosis (IA) at the intensive care unit (ICU) is unknown and difficult to assess since IA also develops in patients lacking specific host factors. In the Netherlands, increasing azole-resistance in Aspergillus fumigatus complicates treatment of patients with IA. The aim of this study was to determine the prevalence of IA by azole-resistant A. fumigatus at the ICU among patients receiving antifungal treatment and to follow their clinical outcome and prognosis. A retrospective cohort study was conducted in a university hospital ICU from January 2010 to December 2013. From all patients who received antifungal treatment for suspected IA, relevant clinical and microbiological data were collected using a standardised questionnaire. Of 9,121 admitted ICU-patients, 136 had received antifungal treatment for suspected IA, of which 38 had a positive A. fumigatus culture. Ten of the 38 patients harboured at least one azole-resistant isolate. Resistance mechanisms consisted of alterations in the cyp51A gene, more specific TR34/L98H and TR46/T289A/Y121F. Microsatellite typing did not show clonal relatedness, though isolates from two patients were genetically related. The overall 90-day mortality of patients with IA by azole-resistant A. fumigatus and patients with suspicion of IA by azole-susceptible isolates in the ICU was 100% (10/10) vs 82% (23/28) respectively. We conclude that the changing pattern of IA in ICU patients requires appropriate criteria for recognition, diagnosis and rapid resistance tests. The increase in azole resistance rates also challenges a reconsideration of empirical antifungal therapy. PMID:27541498

  15. Resistance of Candida species to antifungal agents used in the treatment of onychomycosis: a review of current problems.

    PubMed

    Evans, E G

    1999-11-01

    Treatment of Candida infections with fluconazole has resulted in the emergence of drug resistance, a problem particularly apparent in HIV-infected patients. Frequently, the yeast is also cross-resistant to itraconazole and other azoles. In neutropenic patients fluconazole therapy or prophylaxis has caused overgrowth and infection by inherently less susceptible species of Candida, principally C. glabrata and C. krusei. Consequently, the use of intermittent long-term azole therapy to treat onychomycosis could result in changes in the commensal yeast flora of patients--either resistance or pathogen shift. An 'off-study' investigation undertaken in patients receiving either continuous terbinafine or intermittent itraconazole for toenail onychomycosis (L.I.ON. study) showed no evidence of changes in the yeast species present, nor in their sensitivity to itraconazole or fluconazole. Although intermittent itraconazole seems unlikely to cause problems in this respect, the situation with regard to intermittent fluconazole therapy of onychomycosis needs further study. PMID:10730912

  16. Mechanisms of azole resistance among clinical isolates of Candida glabrata in Poland.

    PubMed

    Szweda, Piotr; Gucwa, Katarzyna; Romanowska, Ewa; Dzierzanowska-Fangrat, Katarzyna; Naumiuk, Łukasz; Brillowska-Dabrowska, Anna; Wojciechowska-Koszko, Iwona; Milewski, Sławomir

    2015-06-01

    Candida glabrata is currently ranked as the second most frequently isolated aetiological agent of human fungal infections, next only to Candida albicans. In comparison with C. albicans, C. glabrata shows lower susceptibility to azoles, the most common agents used in treatment of fungal infections. Interestingly, the mechanisms of resistance to azole agents in C. albicans have been much better investigated than those in C. glabrata. The aim of the presented study was to determine the mechanisms of resistance to azoles in 81 C. glabrata clinical isolates from three different hospitals in Poland. The investigation was carried out with a Sensititre Yeast One test and revealed that 18 strains were resistant to fluconazole, and 15 were cross-resistant to all other azoles tested (voriconazole, posaconazole and itraconazole). One isolate resistant to fluconazole was cross-resistant to voriconazole, and resistance to voriconazole only was observed in six other isolates. All strains were found to be susceptible to echinocandins and amphotericin B, and five were classified as resistant to 5-fluorocytosine. The sequence of the ERG11 gene encoding lanosterol 14-α demethylase (the molecular target of azoles) of 41 isolates, including all strains resistant to fluconazole and three resistant only to voriconazole, was determined, and no amino acid substitutions were found. Real-time PCR studies revealed that 13 of 15 azole-resistant strains showed upregulation of the CDR1 gene encoding the efflux pump. No upregulation of expression of the CDR2 or ERG11 gene was observed. PMID:25818698

  17. Antifungal polypeptides

    DOEpatents

    Altier, Daniel J.; Ellanskaya, Irina; Ellanskaya, legal representative, Natalia; Gilliam, Jacob T.; Hunter-Cevera, Jennie; Presnail, James K.; Schepers, Eric; Simmons, Carl R.; Torok, Tamas; Yalpani, Nasser

    2009-09-15

    The invention relates to antifungal compositions and methods for protecting a plant from a fungal pathogen. Compositions including antifungal polypeptides isolated from a fungal fermentation broth are provided.

  18. Identification, antifungal susceptibility and scanning electron microscopy of a keratinolytic strain of Rhodotorula mucilaginosa: a primary causative agent of onychomycosis.

    PubMed

    da Cunha, Marcel M L; dos Santos, Luana P B; Dornelas-Ribeiro, Marcos; Vermelho, Alane B; Rozental, Sonia

    2009-04-01

    Onychomycosis is a dermatological problem of high prevalence that mainly affects the hallux toenail. Onychomycosis caused by the yeast Rhodotorula mucilaginosa was identified using colony morphology, light microscopy, urease and carbohydrate metabolism in a 57-year-old immunocompetent patient from Rio de Janeiro, Brazil. High-resolution scanning electron microscopy of nail fragments, processed by a noncoating method, led to the observation with fine detail of the structures of both nail and fungus involved in the infection. Yeasts were mainly found inside grooves in the nail. Budding yeasts presented a spiral pattern of growth and blastoconidia were found in the nail groove region. Keratinase assays and keratin enzymography revealed that this isolate was highly capable of degrading keratin. Antifungal susceptibility tests showed that the fungus was susceptible to low concentrations of amphotericin B and 5-flucytosine and resistant to high concentrations of fluconazole, itraconazole, voriconazole and terbinafine. These findings showed data for the first time concerning the interaction of R. mucilaginosa in toenail infection and suggest that this emerging yeast should also be considered an opportunistic primary causative agent of onychomycosis. PMID:19170752

  19. In Vitro Susceptibility of Candida Species to Four Antifungal Agents Assessed by the Reference Broth Microdilution Method

    PubMed Central

    Eksi, Fahriye; Gayyurhan, Efgan Dogan; Balci, Iclal

    2013-01-01

    This study was performed to determine the distribution of Candida species isolated from the blood cultures of the patients hospitalized in our hospital and to investigate their antifungal susceptibility. Candida strains were identified at species level by using classical methods and API ID 32C (bioMerieux, France) identification kits. The susceptibility of the strains to amphotericin B, fluconazole, voriconazole, and caspofungin was evaluated by using the reference broth microdilution method in document M27-A3 of the Clinical and Laboratory Standards Institute. Of the 111 Candida strains isolated, 47.7% were identified as C. albicans and 52.3% as non-albicans Candida strains. The MIC ranges were 0.03–1 μg/mL for amphotericin B, 0.125–≥64 μg/mL for fluconazole, 0.03–16 μg/mL for voriconazole, and 0.015–0.25 μg/mL for caspofungin. All Candida strains were susceptible to amphotericin B and caspofungin. 10.8% isolates were resistant to fluconazole and 8.1% isolates were dose-dependent susceptible. While 0.9% isolate was resistant to voriconazole, 0.9% isolate was dose-dependent susceptible. In our study, C. albicans and C. parapsilosis were the most frequently encountered agents of candidemia and it was detected that voriconazole with a low resistance rate might also be used with confidence in the treatment of infections occurring with these agents, primarily besides amphotericin B and caspofungin. PMID:24250260

  20. Resistance to antifungals that target CYP51.

    PubMed

    Parker, Josie E; Warrilow, Andrew G S; Price, Claire L; Mullins, Jonathan G L; Kelly, Diane E; Kelly, Steven L

    2014-10-01

    Fungal diseases are an increasing global burden. Fungi are now recognised to kill more people annually than malaria, whilst in agriculture, fungi threaten crop yields and food security. Azole resistance, mediated by several mechanisms including point mutations in the target enzyme (CYP51), is increasing through selection pressure as a result of widespread use of triazole fungicides in agriculture and triazole antifungal drugs in the clinic. Mutations similar to those seen in clinical isolates as long ago as the 1990s in Candida albicans and later in Aspergillus fumigatus have been identified in agriculturally important fungal species and also wider combinations of point mutations. Recently, evidence that mutations originate in the field and now appear in clinical infections has been suggested. This situation is likely to increase in prevalence as triazole fungicide use continues to rise. Here, we review the progress made in understanding azole resistance found amongst clinically and agriculturally important fungal species focussing on resistance mechanisms associated with CYP51. Biochemical characterisation of wild-type and mutant CYP51 enzymes through ligand binding studies and azole IC50 determinations is an important tool for understanding azole susceptibility and can be used in conjunction with microbiological methods (MIC50 values), molecular biological studies (site-directed mutagenesis) and protein modelling studies to inform future antifungal development with increased specificity for the target enzyme over the host homologue. PMID:25320648

  1. Antifungal drug resistance of oral fungi.

    PubMed

    Niimi, Masakazu; Firth, Norman A; Cannon, Richard D

    2010-02-01

    Fungi comprise a minor component of the oral microbiota but give rise to oral disease in a significant proportion of the population. The most common form of oral fungal disease is oral candidiasis, which has a number of presentations. The mainstay for the treatment of oral candidiasis is the use of polyenes, such as nystatin and amphotericin B, and azoles including miconazole, fluconazole, and itraconazole. Resistance of fungi to polyenes is rare, but some Candida species, such as Candida glabrata and C. krusei, are innately less susceptible to azoles, and C. albicans can acquire azole resistance. The main mechanism of high-level fungal azole resistance, measured in vitro, is energy-dependent drug efflux. Most fungi in the oral cavity, however, are present in multispecies biofilms that typically demonstrate an antifungal resistance phenotype. This resistance is the result of multiple factors including the expression of efflux pumps in the fungal cell membrane, biofilm matrix permeability, and a stress response in the fungal cell. Removal of dental biofilms, or treatments to prevent biofilm development in combination with antifungal drugs, may enable better treatment and prevention of oral fungal disease. PMID:20155503

  2. Enhanced production of farnesol by Candida albicans treated with four azoles.

    PubMed

    Hornby, Jacob M; Nickerson, Kenneth W

    2004-06-01

    The dimorphic fungus Candida albicans excretes farnesol, which is produced enzymatically from the sterol biosynthetic intermediate farnesyl pyrophosphate. Inhibition of C. albicans by four azole antifungals, fluconazole, ketoconazole, miconazole, and clotrimazole, caused elevated farnesol production (10- to 45-fold). Furthermore, farnesol production occurs in both laboratory strains and clinical isolates (J. M. Hornby et al., Appl. Environ. Microbiol. 67:2982-2992, 2001) of C. albicans. PMID:15155241

  3. Screening for amino acid substitutions in the Candida albicans Erg11 protein of azole-susceptible and azole-resistant clinical isolates: new substitutions and a review of the literature.

    PubMed

    Morio, Florent; Loge, Cedric; Besse, Bernard; Hennequin, Christophe; Le Pape, Patrice

    2010-04-01

    For several years, azole antifungal drugs have been a treatment option for potentially life-threatening Candida infections. However, azole resistance can occur through various mechanisms such as alterations in ERG11, encoding lanosterol 14alpha-demethylase (CYP51). In this study, we investigated the antifungal susceptibility to fluconazole, itraconazole, and voriconazole of 73 clinical isolates of Candida albicans. Screening for amino acid substitutions in Erg11 was performed on each of the 73 isolates. Twenty isolates displayed a marked decrease in azole susceptibility. Amino acid substitutions were detected in more than two-thirds of the strains. In all, 23 distinct substitutions were identified. Four have not been described previously, among which N136Y and Y447H are suspected to be involved in azole resistance. We suggest that the high genetic polymorphism of ERG11 must be considered in the rationale design of new azole compounds targeting lanosterol 14alpha-demethylase. A review of all Erg11 amino acid polymorphisms described to date is given. PMID:20226328

  4. The molecular mechanism of azole resistance in Aspergillus fumigatus: from bedside to bench and back.

    PubMed

    Wei, Xiaolei; Zhang, Yuanwei; Lu, Ling

    2015-02-01

    The growing use of immunosuppressive therapies has resulted in a dramatic increased incidence of invasive fungal infections (IFIs) caused by Aspergillus fumigatus, a common pathogen, and is also associated with a high mortality rate. Azoles are the primary guideline-recommended therapy agents for first-line treatment and prevention of IFIs. However, increased azole usage in medicinal and agricultural settings has caused azole-resistant isolates to repeatedly emerge in the environment, resulting in a significant threat to human health. In this review, we present and summarize current research on the resistance mechanisms of azoles in A. fumigatus as well as efficient susceptibility testing methods. Moreover, we analyze and discuss the putative clinical (bedside) indication of these findings from bench work. PMID:25626363

  5. Management of symptomatic erosive-ulcerative lesions of oral lichen planus in an adult Egyptian population using Selenium-ACE combined with topical corticosteroids plus antifungal agent

    PubMed Central

    Belal, Mahmoud Helmy

    2015-01-01

    Aim: Oral lichen planus (OLP) is a chronic mucocutaneous disease with an immunological etiology. This study was conducted to evaluate the effect of selenium combined with Vitamins A, C & E (Selenium-ACE) in the treatment of erosive-ulcerative OLP as an adjunctive to topical corticosteroids plus antifungal agent. Subjects and Methods: Thirty patients with a confirmed clinical and histopathologic diagnosis of OLP participated in this clinical trial. Patients were randomly allocated into one of three groups and treated as follows: (I) Topical corticosteroids, (II) topical corticosteroids plus antifungal, and (III) SE-ACE combined with topical corticosteroids plus antifungal. The patients were followed for 6 weeks. The pain and severity of the lesions were recorded at the initial and follow-up visits. All recorded data were analyzed using paired t-test and ANOVA test. A P ≤ 0.05 was considered significant. Results: The experimental groups showed a marked reduction in pain sensation and size of lesions, particularly in the final follow-up period, but there was no significant difference between the first two Groups I and II. However, healing of lesions and improvement of pain sensation was effective in Group III since a significant difference was found favoring Group III over both Groups I and II. Conclusion: No significant difference was found in treating erosive-ulcerative lesions of OLP by topical corticosteroids alone or combined with antifungal. However, when using SE-ACE in combination with topical corticosteroids plus antifungal, this approach may be effective in managing ulcerative lesions of OLP; but more research with a larger sample size and a longer evaluation period may be recommended. PMID:26681847

  6. In vitro and in vivo study on the effect of antifungal agents on hematopoietic cells in mice.

    PubMed

    Samalidou, Maria; Bougiouklis, Dimitris; Vyzantiadis, Timoleon-Achilleas; Meletiadis, Joseph; Monokrousos, Nikolaos; Siotou, Eleni; Sivropoulou, Afroditi; Anagnostopoulos, Achilles; Sotiropoulos, Damianos

    2015-12-01

    Liposomal amphotericin B, voriconazole, and caspofungin are currently used for systemic and severe fungal infections. Patients with malignant diseases are treated with granulocyte-colony stimulating factor (G-CSF) for the recovery of granulocytes after chemotherapy or hematopoietic cell (HC) transplantation. Since they have a high incidence of fungal infections, they inevitably receive antifungal drugs for treatment and prophylaxis. Despite their proven less toxicity for various cell types comparatively with amphotericin B and the decrease in the number of leukocytes that has been reported as a possible complication in clinical studies, the effect of liposomal amphotericin B, voriconazole, and caspofungin on HCs has not been clarified. The present study aimed to examine the in vitro and in vivo effect of these three modern antifungals on HCs. Colony-forming unit (CFU) assays of murine bone marrow cells were performed in methylcellulose medium with or without cytokines and in the presence or absence of various concentrations of liposomal amphotericin B, voriconazole, and caspofungin. In the in vivo experiments, the absolute number of granulocytes was determined during leukocyte recovery in sublethally irradiated mice receiving each antifungal agent separately, with or without G-CSF. In vitro, all three antifungal drugs were nontoxic and, interestingly, they significantly increased the number of CFU-granulocyte-macrophage colonies in the presence of cytokines, at all concentrations tested. This was contrary to the concentration-dependent toxicity and the significant decrease caused by conventional amphotericin B. In vivo, the number of granulocytes was significantly higher with caspofungin plus G-CSF treatment, higher and to a lesser extent higher, but not statistically significantly, with voriconazole plus G-CSF and liposomal amphotericin B plus G-CSF treatments, respectively, as compared with G-CSF alone. These data indicate a potential synergistic effect of

  7. Synthesis and evaluation of new quinazolone derivatives of nalidixic acid as potential antibacterial and antifungal agents.

    PubMed

    Grover, Gaurav; Kini, Suvarna G

    2006-02-01

    In continuation of our work on synthesis of biheterocycles carrying the biodynamic heterocyclic systems at position 3, a series of new nalidixic acid derivatives having quinazolones moiety were synthesised to achieve enhanced biological activity and wide spectrum of activity. Nalidixic acid was first converted into its acid chloride using thionyl chloride as an acylating agent at laboratory temperature. Later it was converted to methyl ester. Nalidixoyl chloride formed vigorously reacts with methanol to give a methyl ester of nalidixic acid. The ester on addition of hydrazine hydrate furnished nalidixic acid hydrazide. Appropriate anthranilic acid was refluxed with acetic anhydride to form Benzoxazine/Acetanthranil. 5-iodo-derivative of anthranilic acid was prepared and also utilised to obtain 6-iodo-Benzoxazine/Acetanthranil. Also, 6-nitro-Benzoxazine/Acetanthranil was obtained by nitration of acetanthranil using conc. H(2)SO(4) and fuming HNO(3). Equimolar proportions of the appropriate synthesised acetanthranils and nalidixic acid hydrazide in the presence of ethanol were refluxed to synthesise quinazolones. Elemental analysis and IR spectra confirmed nalidixic acid hydrazide formation. The structures of the compounds obtained have been established on the basis of Spectral (IR, (1)H NMR and mass) data. The current study also involves in vitro antimicrobial screening (using Agar dilution and Punch well diffusion method) of synthesised quinazolone derivatives bearing nalidixic acid moiety on randomly collected microbial strains. The derivatives Ga (NAH), Gb (QN) and Gd (NiQNA) showed marked inhibitory activity against enteric pathogen like Aeromonas hydrophila, a causative agent of diarrhoea in both children as well as adults. Among the respiratory pathogens included in study, derivative Gd (NiQNA) was found to be active against Streptococcus pyogenes. No significant inhibitory activity was seen by any of synthesised derivatives against Coagulase negative

  8. The in vitro antifungal activity of sudanese medicinal plants against Madurella mycetomatis, the eumycetoma major causative agent.

    PubMed

    Elfadil, Hassabelrasoul; Fahal, Ahmed; Kloezen, Wendy; Ahmed, Elhadi M; van de Sande, Wendy

    2015-03-01

    Eumycetoma is a debilitating chronic inflammatory fungal infection that exists worldwide but it is endemic in many tropical and subtropical regions. The major causative organism is the fungus Madurella mycetomatis. The current treatment of eumycetoma is suboptimal and characterized by low cure rate and high recurrence rates. Hence, an alternative therapy is needed to address this. Here we determined the antifungal activity of seven Sudanese medicinal plant species against Madurella mycetomatis. Of these, only three species; Boswellia papyrifera, Acacia nubica and Nigella sativa, showed some antifungal activity against M. mycetomatis and were further studied. Crude methanol, hexane and defatted methanol extracts of these species were tested for their antifungal activity. B. papyrifera had the highest antifungal activity (MIC50 of 1 ug/ml) and it was further fractionated. The crude methanol and the soluble ethyl acetate fractions of B. papyrifera showed some antifungal activity. The Gas-Liquid-Chromatography hybrid Mass-Spectrophotometer analysis of these two fractions showed the existence of beta-amyrin, beta-amyrone, beta-Sitosterol and stigmatriene. Stigmatriene had the best antifungal activity, compared to other three phytoconstituents, with an MIC-50 of 32 μg/ml. Although the antifungal activity of the identified phytoconstituents was only limited, the antifungal activity of the complete extracts is more promising, indicating synergism. Furthermore these plant extracts are also known to have anti-inflammatory activity and can stimulate wound-healing; characteristics which might also be of great value in the development of novel therapeutic drugs for this chronic inflammatory disease. Therefore further exploration of these plant species in the treatment of mycetoma is encouraging. PMID:25768115

  9. The In Vitro Antifungal Activity of Sudanese Medicinal Plants against Madurella mycetomatis, the Eumycetoma Major Causative Agent

    PubMed Central

    Elfadil, Hassabelrasoul; Fahal, Ahmed; Kloezen, Wendy; Ahmed, Elhadi M.; van de Sande, Wendy

    2015-01-01

    Eumycetoma is a debilitating chronic inflammatory fungal infection that exists worldwide but it is endemic in many tropical and subtropical regions. The major causative organism is the fungus Madurella mycetomatis. The current treatment of eumycetoma is suboptimal and characterized by low cure rate and high recurrence rates. Hence, an alternative therapy is needed to address this. Here we determined the antifungal activity of seven Sudanese medicinal plant species against Madurella mycetomatis. Of these, only three species; Boswellia papyrifera, Acacia nubica and Nigella sativa, showed some antifungal activity against M. mycetomatis and were further studied. Crude methanol, hexane and defatted methanol extracts of these species were tested for their antifungal activity. B. papyrifera had the highest antifungal activity (MIC50 of 1 ug/ml) and it was further fractionated. The crude methanol and the soluble ethyl acetate fractions of B. papyrifera showed some antifungal activity. The Gas-Liquid-Chromatography hybrid Mass-Spectrophotometer analysis of these two fractions showed the existence of beta-amyrin, beta-amyrone, beta-Sitosterol and stigmatriene. Stigmatriene had the best antifungal activity, compared to other three phytoconstituents, with an MIC-50 of 32 μg/ml. Although the antifungal activity of the identified phytoconstituents was only limited, the antifungal activity of the complete extracts is more promising, indicating synergism. Furthermore these plant extracts are also known to have anti-inflammatory activity and can stimulate wound-healing; characteristics which might also be of great value in the development of novel therapeutic drugs for this chronic inflammatory disease. Therefore further exploration of these plant species in the treatment of mycetoma is encouraging. PMID:25768115

  10. Ibuprofen Potentiates the In Vivo Antifungal Activity of Fluconazole against Candida albicans Murine Infection

    PubMed Central

    Miranda, Isabel M.; Silva-Dias, Ana; Silva, Ana P.; Rodrigues, Acácio G.; Pina-Vaz, Cidália

    2015-01-01

    Candida albicans is the most prevalent cause of fungemia worldwide. Its ability to develop resistance in patients receiving azole antifungal therapy is well documented. In a murine model of systemic infection, we show that ibuprofen potentiates fluconazole antifungal activity against a fluconazole-resistant strain, drastically reducing the fungal burden and morbidity. The therapeutic combination of fluconazole with ibuprofen may constitute a new approach for the management of antifungal therapeutics to reverse the resistance conferred by efflux pump overexpression. PMID:25845879

  11. In vitro susceptibility patterns of clinically important Trichophyton and Epidermophyton species against nine antifungal drugs.

    PubMed

    Badali, Hamid; Mohammadi, Rasoul; Mashedi, Olga; de Hoog, G Sybren; Meis, Jacques F

    2015-05-01

    Despite the common, worldwide, occurrence of dermatophytes, little information is available regarding susceptibility profiles against currently available and novel antifungal agents. A collection of sixty-eight clinical Trichophyton species and Epidermophyton floccosum were previously identified and verified to the species level by sequencing the internal transcribed spacer (ITS) regions of rDNA. MICs of amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, isavuconazole, terbinafine and MECs of caspofungin and anidulafungin were performed based on CLSI M38-A2. The resulting MIC90 s of all strains were, in increasing order, as follows: terbinafine (0.063 mg l(-1) ); posaconazole (1 mg l(-1) ); isavuconazole and anidulafungin (2 mg l(-1) ); itraconazole, voriconazole, amphotericin B, and caspofungin (4 mg l(-1) ) and fluconazole (>64 mg l(-1) ). These results confirm that terbinafine is an excellent agent for treatment of dermatophytosis due to T. rubrum, T. mentagrophytes, T. verrucosum, T. schoenleinii and E. floccosum. In addition, the new azoles POS and ISA are potentially useful antifungals to treat dermatophytosis. However, the clinical effectiveness of these novel antifungals remains to be determined. PMID:25757042

  12. Expression of Efflux Pumps and Fatty Acid Activator One Genes in Azole Resistant Candida Glabrata Isolated From Immunocompromised Patients.

    PubMed

    Farahyar, Shirin; Zaini, Farideh; Kordbacheh, Parivash; Rezaie, Sassan; Falahati, Mehraban; Safara, Mahin; Raoofian, Reza; Hatami, Kamran; Mohebbi, Masoumeh; Heidari, Mansour

    2016-07-01

    Acquired azole resistance in opportunistic fungi causes severe clinical problems in immunosuppressed individuals. This study investigated the molecular mechanisms of azole resistance in clinical isolates of Candida glabrata. Six unmatched strains were obtained from an epidemiological survey of candidiasis in immunocompromised hosts that included azole and amphotericin B susceptible and azole resistant clinical isolates. Candida glabrata CBS 138 was used as reference strain. Antifungal susceptibility testing of clinical isolates was evaluated using Clinical and Laboratory Standards Institute (CLSI) methods. Complementary DNA-amplified fragment length polymorphism (cDNA-AFLP) technology, semi-quantitative RT-PCR, and sequencing were employed for identification of potential genes involved in azole resistance. Candida glabrata Candida drug resistance 1 (CgCDR1) and Candida glabrata Candida drug resistance 2 (CgCDR2) genes, which encode for multidrug transporters, were found to be upregulated in azole-resistant isolates (≥2-fold). Fatty acid activator 1 (FAA1) gene, belonging to Acyl-CoA synthetases, showed expression in resistant isolates ≥2-fold that of the susceptible isolates and the reference strain. This study revealed overexpression of the CgCDR1, CgCDR2, and FAA1 genes affecting biological pathways, small hydrophobic compounds transport, and lipid metabolism in the resistant clinical C.glabrata isolates. PMID:27424018

  13. Interlaboratory evaluation of VITEK2 system and Sensititre YeastOne® for antifungal susceptibility testing of yeasts isolated from blood cultures against four antifungal agents.

    PubMed

    Farina, Claudio; Manso, Esther; Andreoni, Stefano; Conte, Marco; Fazii, Paolo; Lombardi, Gianluigi; Sanna, Silvana; Russello, Giuseppe

    2011-04-01

    An interlaboratory evaluation (seven centers) of VITEK2 System and Sensititre YeastOne® was conducted to test the antifungal susceptibilities of yeasts. The MICs of amphotericin B, fluconazole, flucytosine, and voriconazole were determined for 70 isolates of Candida spp. Our results demonstrated a higher interlaboratory agreement of VITEK 2 System than Sensititre YeastOne©. A good concordance between the two methods was observed for amphotericin B, fluconazole, voriconazole and 5-fluorocytosine (from 81.4% to 88.6%). The study suggests the potential value of the VITEK2 System as a convenient alternative method for testing the susceptibility of yeasts. It also indicates the need for further optimization of MIC endpoint criteria to improve interlaboratory agreement. PMID:21617832

  14. Epidemiology, species distribution, antifungal susceptibility, and ERG11 mutations of Candida species isolated from pregnant Chinese Han women.

    PubMed

    Yang, L; Su, M Q; Ma, Y Y; Xin, Y J; Han, R B; Zhang, R; Wen, J; Hao, X K

    2016-01-01

    The widespread use of antifungal agents has led to increasing azole resistance in Candida species. A major azole-resistance mechanism involves point mutations in the ERG11 gene, which encodes cytochrome P450 lanosterol 14a-demethylase. In this study, vaginal swabs were obtained from 657 pregnant Chinese Han women and cultured appropriately. The open reading frame of the obtained fungal species were amplified by PCR and sequenced; additionally, the ERG11 gene of the isolated Candida species was amplified and sequenced, and the antifungal susceptibility of the isolated species was determined. The vaginal swabs of 124 women produced fungal cultures; five species of Candida were isolated from the patients, among which Candida albicans was predominant. Twelve C. albicans isolates (13.8%) were resistant to fluconazole and 2 (2.2%) were resistant to itraconazole. Seventeen mutations, including 9 silent and 8 missense mutations, were identified in the ERG11 gene of 31 C. albicans isolates. Our findings suggest that infection caused by C. albicans and non-C. albicansis common in Chinese Han women of reproductive age. Moreover, the relationship between Candida infection and certain epidemiological factors emphasizes the need to educate women about the precise diagnosis and punctual treatment of vaginitis. PMID:27173274

  15. Advancements in Topical Antifungal Vehicles.

    PubMed

    Kircik, Leon H

    2016-02-01

    The primary treatment for superficial fungal infections is antifungal topical formulations, and allylamines and azoles represent the two major classes of topical formulations that are used to treat these infections. The stratum corneum (SC) is composed of keratinocytes that are surrounded by a matrix of lipids. The efficacy of topically applied formulations depends on their ability to penetrate this lipid matrix, and the vehicle plays an integral role in the penetration of active molecule into skin. There are several challenges to formulating topical drugs, which include the biotransformation of the active molecules as they pass through the SC and the physical changes that occur to the vehicle itself when it is applied to the skin. This article will review current and emerging topical antifungal vehicles. PMID:26885798

  16. Contribution of Clinically Derived Mutations in ERG11 to Azole Resistance in Candida albicans

    PubMed Central

    Flowers, Stephanie A.; Colón, Brendan; Whaley, Sarah G.; Schuler, Mary A.

    2014-01-01

    In Candida albicans, the ERG11 gene encodes lanosterol demethylase, the target of the azole antifungals. Mutations in ERG11 that result in an amino acid substitution alter the abilities of the azoles to bind to and inhibit Erg11, resulting in resistance. Although ERG11 mutations have been observed in clinical isolates, the specific contributions of individual ERG11 mutations to azole resistance in C. albicans have not been widely explored. We sequenced ERG11 in 63 fluconazole (FLC)-resistant clinical isolates. Fifty-five isolates carried at least one mutation in ERG11, and we observed 26 distinct positions in which amino acid substitutions occurred. We mapped the 26 distinct variant positions in these alleles to four regions in the predicted structure for Erg11, including its predicted catalytic site, extended fungus-specific external loop, proximal surface, and proximal surface-to-heme region. In total, 31 distinct ERG11 alleles were recovered, with 10 ERG11 alleles containing a single amino acid substitution. We then characterized 19 distinct ERG11 alleles by introducing them into the wild-type azole-susceptible C. albicans SC5314 strain and testing them for susceptibilities to FLC, itraconazole (ITC), and voriconazole (VRC). The strains that were homozygous for the single amino acid substitutions Y132F, K143R, F145L, S405F, D446E, G448E, F449V, G450E, and G464S had a ≥4-fold increase in FLC MIC. The strains that were homozygous for several double amino acid substitutions had decreased azole susceptibilities beyond those conferred by any single amino acid substitution. These findings indicate that mutations in ERG11 are prevalent among azole-resistant clinical isolates and that most mutations result in appreciable changes in FLC and VRC susceptibilities. PMID:25385095

  17. Contribution of clinically derived mutations in ERG11 to azole resistance in Candida albicans.

    PubMed

    Flowers, Stephanie A; Colón, Brendan; Whaley, Sarah G; Schuler, Mary A; Rogers, P David

    2015-01-01

    In Candida albicans, the ERG11 gene encodes lanosterol demethylase, the target of the azole antifungals. Mutations in ERG11 that result in an amino acid substitution alter the abilities of the azoles to bind to and inhibit Erg11, resulting in resistance. Although ERG11 mutations have been observed in clinical isolates, the specific contributions of individual ERG11 mutations to azole resistance in C. albicans have not been widely explored. We sequenced ERG11 in 63 fluconazole (FLC)-resistant clinical isolates. Fifty-five isolates carried at least one mutation in ERG11, and we observed 26 distinct positions in which amino acid substitutions occurred. We mapped the 26 distinct variant positions in these alleles to four regions in the predicted structure for Erg11, including its predicted catalytic site, extended fungus-specific external loop, proximal surface, and proximal surface-to-heme region. In total, 31 distinct ERG11 alleles were recovered, with 10 ERG11 alleles containing a single amino acid substitution. We then characterized 19 distinct ERG11 alleles by introducing them into the wild-type azole-susceptible C. albicans SC5314 strain and testing them for susceptibilities to FLC, itraconazole (ITC), and voriconazole (VRC). The strains that were homozygous for the single amino acid substitutions Y132F, K143R, F145L, S405F, D446E, G448E, F449V, G450E, and G464S had a ≥ 4-fold increase in FLC MIC. The strains that were homozygous for several double amino acid substitutions had decreased azole susceptibilities beyond those conferred by any single amino acid substitution. These findings indicate that mutations in ERG11 are prevalent among azole-resistant clinical isolates and that most mutations result in appreciable changes in FLC and VRC susceptibilities. PMID:25385095

  18. Design, Synthesis, and Structure--Activity Relationship of New 2-Aryl-3,4-dihydro-β-carbolin-2-ium Salts as Antifungal Agents.

    PubMed

    Hou, Zhe; Zhu, Li-Fei; Yu, Xin-chi; Sun, Ma-Qiang; Miao, Fang; Zhou, Le

    2016-04-13

    Twenty-two 2-aryl-9-methyl-3,4-dihydro-β-carbolin-2-ium bromides along with four 9-demethylated derivatives were synthesized and characterized by spectroscopic analysis. By using the mycelium growth rate method, the compounds were evaluated for antifungal activities in vitro against six plant pathogenic fungi, and structure-activity relationships (SAR) were derived. Almost all of the compounds showed obvious inhibition activity on each of the fungi at 150 μM. For all of the fungi, 10 of the compounds showed average inhibition rates of >80% at 150 μM, and most of their EC50 values were in the range of 2.0-30.0 μM. SAR analysis showed that the substitution pattern of the N-aryl ring significantly influences the activity; N9-alkylation improves the activity, whereas aromatization of ring-C reduces the activity. It was concluded that the present research provided a series of new 2-aryl-9-alkyl-3,4-dihydro-β-carbolin-2-iums with excellent antifungal potency and structure optimization design for the development of new carboline antifungal agents. PMID:27004437

  19. Application of "Hydrogen-Bonding Interaction" in Drug Design. Part 2: Design, Synthesis, and Structure-Activity Relationships of Thiophosphoramide Derivatives as Novel Antiviral and Antifungal Agents.

    PubMed

    Lu, Aidang; Ma, Yuanyuan; Wang, Ziwen; Zhou, Zhenghong; Wang, Qingmin

    2015-11-01

    On the basis of the structure of natural product harmine, lead compound 18, and the structure of compounds in part 1, a series of thiophosphoramide derivatives 1-17 were designed and synthesized from various amines in one step. Their antiviral and antifungal activities were evaluated. Most of the compounds showed significantly higher antiviral activity against tobacco mosaic virus (TMV) than commercial virucide ribavirin. Compound (R,R)-17 showed the best anti-TMV activity in vitro (70%/500 μg/mL and 33%/100 μg/mL) and in vivo (inactivation effect, 68%/500 μg/mL and 30%/100 μg/mL; curative effect, 64%/500 μg/mL and 31%/100 μg/mL; protection effect, 66%/500 μg/mL and 31%/100 μg/mL), which is higher than that of ningnanmycin and lead compound 18. The antiviral activity of (R,R)-17·HCl is about similar to that of (R,R)-17. However, the antifungal activity of (R,R)-17·HCl against Puccinia sorghi is slightly lower than that of (R,R)-17. The systematic study provides compelling evidence that these simple thiophosphoramide compounds could become efficient antiviral and antifungal agents. PMID:26485246

  20. Molecular structures and biological evaluation of 2-chloro-3-(n-alkylamino)-1,4-napthoquinone derivatives as potent antifungal agents

    NASA Astrophysics Data System (ADS)

    Pawar, Omkar; Patekar, Ashwini; Khan, Ayesha; Kathawate, Laxmi; Haram, Santosh; Markad, Ganesh; Puranik, Vedavati; Salunke-Gawali, Sunita

    2014-02-01

    Derivatives of 2-chloro-3-(n-alkylamino)-1,4-naphthoquinone {n-alkyl: methyl; L-1, ethyl; L-2, propyl; L-3 and butyl; L-4} have been synthesized and characterized by elemental analysis, FT-IR, 1H NMR, UV-visible spectroscopy, LC-MS and single crystal X-ray diffraction studies. Antifungal activity of L-1 to L-4 has been evaluated against Candida tropicalis, Candida albicans and Cladosporium herbarum. The intramolecular hydrogen bonding affects the N-H vibrational frequency in L-2 (3273 cm-1). The single crystal X-ray structure reveal that L-1 and L-3 crystallizes in triclinic P-1, whereas L-2 crystallizes in orthorhombic Pca21 space group. An extensive intra and intermolecular hydrogen bonding interactions were observed in L-1 to L-3 which leads to molecular association. Intramolecular N-H⋯O hydrogen bonding were observed in L-1 to L-3. Moreover π-π stacking interactions were observed between the quinonoid rings of L-1 and L-3, however no such interactions were observed in L-2. An electrochemical study showed molecular association of L-1 to L-4 in DMSO solution. Compounds L-1 to L-4 were found to be potent antifungal agents against all the three strains, especially against C. tropicalis. Amongst these promising antifungal candidates, L-1 showed better activity compared to the clinically administered antifungal drug Amphotericin B and Nitrofurantoin with MIC = 1.25 μg ml-1 and MIC = 0.025 μg ml-1 respectively against C. albicans. Structure and activity relationship (SAR) study suggest a Log P value of ˜2.0 and the cyclic voltammetry studies reveals additional chemical processes for L-1, which exhibits maximum activity against all fungal strains.

  1. Functionalised isocoumarins as antifungal compounds: Synthesis and biological studies.

    PubMed

    Simic, Milena; Paunovic, Nikola; Boric, Ivan; Randjelovic, Jelena; Vojnovic, Sandra; Nikodinovic-Runic, Jasmina; Pekmezovic, Marina; Savic, Vladimir

    2016-01-01

    A series of novel 3-substituted isocoumarins was prepared via Pd-catalysed coupling processes and screened in vitro for antifungal activity against Candida species. The study revealed antifungal potential of isocoumarins possessing the azole substituents, which, in some cases, showed biological properties equal to those of clinically used voriconazole. Selected compounds were also screened against voriconazole resistant Candida krusei 6258 and a clinical isolate Candida parapsilosis CA-27. Although the activity against these targets needs to be improved further, the results emphasise additional potential of this new class of antifungal compounds. PMID:26586600

  2. Novel drug delivery strategies for improving econazole antifungal action.

    PubMed

    Firooz, Alireza; Nafisi, Shohreh; Maibach, Howard I

    2015-11-10

    Econazole is a commonly used azole antifungal in clinical treatment of superficial fungal infections. It is generally used as conventional cream and gel preparations under the brand names of Spectazole (United States), Ecostatin (Canada), Pevaryl (Western Europe). Treatment efficiency of antifungal drugs depends on their penetration through target layers of skin at effective concentrations. Econazole's poor water solubility limits its bioavailability and antifungal effects. Therefore, formulation strategies have been examined for delivering econazole through targeted skin sites. The present overview focuses on novel nano-based formulation approaches used to improve econazole penetration through skin for treatment of superficial fungal infections. PMID:26383840

  3. Evaluating food additives as antifungal agents against Monilinia fructicola in vitro and in hydroxypropyl methylcellulose-lipid composite edible coatings for plums.

    PubMed

    Karaca, Hakan; Pérez-Gago, María B; Taberner, Verònica; Palou, Lluís

    2014-06-01

    Common food preservative agents were evaluated in in vitro tests for their antifungal activity against Monilinia fructicola, the most economically important pathogen causing postharvest disease of stone fruits. Radial mycelial growth was measured in Petri dishes of PDA amended with three different concentrations of the agents (0.01-0.2%, v/v) after 7 days of incubation at 25 °C. Thirteen out of fifteen agents tested completely inhibited the radial growth of the fungus at various concentrations. Among them, ammonium carbonate, ammonium bicarbonate and sodium bicarbonate were the most effective while sodium acetate and sodium formate were the least effective. The effective agents and concentrations were tested as ingredients of hydroxypropyl methylcellulose (HPMC)-lipid edible coatings against brown rot disease on plums previously inoculated with M. fructicola (curative activity). 'Friar' and 'Larry Ann' plums were inoculated with the pathogen, coated with stable edible coatings about 24h later, and incubated at 20 °C and 90% RH. Disease incidence (%) and severity (lesion diameter) were determined after 4, 6, and 8 days of incubation and the 'area under the disease progress stairs' (AUDPS) was calculated. Coatings containing bicarbonates and parabens significantly reduced brown rot incidence in plums, but potassium sorbate, used at 1.0% in the coating formulation, was the most effective agent with a reduction rate of 28.6%. All the tested coatings reduced disease severity to some extent, but coatings containing 0.1% sodium methylparaben or sodium ethylparaben or 0.2% ammonium carbonate or ammonium bicarbonate were superior to the rest, with reduction rates of 45-50%. Overall, the results showed that most of the agents tested in this study had significant antimicrobial activity against M. fructicola and the application of selected antifungal edible coatings is a promising alternative for the control of postharvest brown rot in plums. PMID:24742996

  4. An overview of topical antifungal therapy in dermatomycoses. A North American perspective.

    PubMed

    Gupta, A K; Einarson, T R; Summerbell, R C; Shear, N H

    1998-05-01

    Dermatophytes cause fungal infections of keratinised tissues, e.g. skin, hair and nails. The organisms belong to 3 genera, Trichophyton, Epidermophyton and Microsporum. Dermatophytes may be grouped into 3 categories based on host preference and natural habitat. Anthropophilic species predominantly infect humans, geophilic species are soil based and may infect both humans and animals, zoophilic species generally infect non-human mammals. It is important to confirm mycologically the clinical diagnosis of onychomycosis and other tinea infections prior to commencing therapy. The identity of the fungal organism may provide guidance about the appropriateness of a given topical antifungal agent. Special techniques may be required to obtain the best yield of fungal organisms from a given site, especially the scalp and nails. It is also important to realise the limitations of certain diagnostic aids e.g., Wood's light examination is positive in tinea capitis due to M. canis and M. audouinii (ectothrix organisms); however, Wood's light examination is negative in T. tonsurans (endothrix organism). Similarly, it is important to be aware that cicloheximide in culture medium will inhibit growth of non-dermatophytes. Appropriate media are therefore required to evaluate the growth of some significant non-dermatophyte moulds. For tinea infections other than tinea capitis and tinea unguium, topical antifungals may be considered. For effective therapy of tinea capitis an oral antifungal is generally necessary. Similarly, oral antifungals are the therapy of choice, especially if onychomycosis is moderate to severe. Furthermore, where the tinea infection involves a large area, in an immunocompromised host or if infection is recurrent with poor response to topical agents, then oral antifungal therapy may be necessary. Topical antifungal agents may be broadly divided into specific and nonspecific agents. The former group includes the polyenes, azoles, allylamines, amorolfine, ciclopirox

  5. In vivo activity of Sapindus saponaria against azole-susceptible and -resistant human vaginal Candida species

    PubMed Central

    2011-01-01

    Background Study of in vivo antifungal activity of the hydroalcoholic extract (HE) and n-BuOH extract (BUTE) of Sapindus saponaria against azole-susceptible and -resistant human vaginal Candida spp. Methods The in vitro antifungal activity of HE, BUTE, fluconazole (FLU), and itraconazole (ITRA) was determined by the broth microdilution method. We obtained values of minimal inhibitory concentration (MIC) and minimum fungicide concentration (MFC) for 46 strains of C. albicans and 10 of C. glabrata isolated from patients with vulvovaginal candidiasis (VVC). VVC was induced in hyperestrogenic Wistar rats with azole-susceptible C. albicans (SCA), azole-resistant C. albicans (RCA), and azole-resistant C. glabrata (RCG). The rats were treated intravaginally with 0.1 mL of HE or BUTE at concentrations of 1%, 2.5% and 5%; 100 μg/mL of FLU (treatment positive control); or distilled water (negative control) at 1, 24, and 48 h after induction of the infection, and the progress of VVC was monitored by culturing and scanning electron microscopy (SEM). The toxicity was evaluated in cervical cells of the HeLa cell line. Results The extracts showed in vitro inhibitory and fungicidal activity against all the isolates, and the MIC and MFC values for the C. glabrata isolates were slightly higher. In vivo, the SCA, RCA, and RCG infections were eliminated by 21 days post-infection, with up to 5% HE and BUTE, comparable to the activity of FLU. No cytotoxic action was observed for either extract. Conclusions Our results demonstrated that HE and BUTE from S. saponaria show inhibitory and fungicidal activity in vitro, in addition to in vivo activity against azole-resistant vaginal isolates of C. glabrata and azole-susceptible and resistant isolates of C. albicans. Also considering the lack of cytotoxicity and the low concentrations of the extracts necessary to eliminate the infection in vivo, HE and BUTE show promise for continued studies with purified antifungal substances in VVC yeast

  6. Etiologic Agents and Antifungal Susceptibility of Oral Candidosis from Romanian patients with HIV-infection or type 1 diabetes mellitus.

    PubMed

    Minea, Bogdan; Nastasa, Valentin; Kolecka, Anna; Mares, Magdalena; Marangoci, Narcisa; Rosca, Irina; Pinteala, Mariana; Hancianu, Monica; Mares, Mihai

    2016-01-01

    This is the first Romanian investigation of oral candidosis in patients suffering of HIV-infection or type 1 diabetes mellitus (T1DM). Candida albicans was the dominant species in both types of isolates: n = 14 (46.7%) in T1DM, n = 60 (69.8%) in HIV. The most frequent non-albicans Candida spp. were Candida kefyr (n = 6; 20%) in T1DM and Candida dubliniensis (n = 8; 9.3%) in HIV. Resistance to fluconazole was detected only in the HIV non-albicans Candida group (n = 8; 9.3%). All isolates were susceptible to VOR. The experimental drug MXP had MIC values equal or close to the ones of VOR. Echinocandin resistance was more frequent than azole resistance. PMID:27282005

  7. Molecular identification and antifungal susceptibility of 186 Candida isolates from vulvovaginal candidiasis in southern China.

    PubMed

    Shi, Xiao-Yu; Yang, Yan-Ping; Zhang, Ying; Li, Wen; Wang, Jie-Di; Huang, Wen-Ming; Fan, Yi-Ming

    2015-04-01

    There is limited information regarding the molecular epidemiology and antifungal susceptibilities of Candida isolates using the Neo-Sensitabs method in patients with vulvovaginal candidiasis (VVC). From August 2012 to March 2013, 301 non-pregnant patients aged 18-50 years with suspected VVC were prospectively screened at a teaching hospital in southern China. The vaginal isolates were identified by DNA sequencing of internal transcribed spacer and the D1/D2 domain. Antifungal susceptibility testing of seven antifungal agents was performed using the Neo-Sensitabs tablet diffusion method. Candida species were isolated from 186 cases (61.79 %). The most common pathogen was Candida albicans (91.4 %), followed by Candida glabrata (4.3 %), Candida tropicalis (3.2 %) and Candida parapsilosis (1.1 %). The susceptibility rates to C. albicans were higher for caspofungin, voriconazole and fluconazole than those for itraconazole, miconazole, ketoconazole and terbinafine (P<0.01). The resistance rates to C. albicans were 4.7, 6.5, 7.1, 7.6, 12.3, 27.7 and 74.7 % for caspofungin, miconazole, itraconazole, voriconazole, fluconazole, ketoconazole and terbinafine, respectively. No drugs tested apart from fluconazole exhibited differences in resistance between C. albicans and non-albicans Candida isolates. The results demonstrate that, using DNA sequencing, C. albicans is the most common isolate from Chinese patients with VVC. Caspofungin, voriconazole and fluconazole may be preferable to other azoles and terbinafine in the treatment of VVC. PMID:25596116

  8. Antifungal Susceptibility Analysis of Clinical Isolates of Candida parapsilosis in Iran

    PubMed Central

    LOTFALI, Ensieh; KORDBACHEH, Parivash; MIRHENDI, Hossein; ZAINI, Farideh; GHAJARI, Ali; MOHAMMADI, Rasoul; NOORBAKHSH, Fatemeh; MOAZENI, Maryam; FALLAHI, Aliakbar; REZAIE, Sassan

    2016-01-01

    Background: Candida parapsilosis is an emergent agent of invasive fungal infections. This yeast is one of the five most widespread yeasts concerned in invasive candidiasis. C. parapsilosis stands out as the second most common yeast species isolated from patients with bloodstream infections especially in neonates with catheter. Recently several reports suggested that its reduced susceptibility to azoles and polyene might become a cause for clinical concern, although C. parapsilosis is not believed to be intensely prone to the development of antifungal resistance. Methods: In the present report, One hundred and twenty clinical isolates of C. parapsilosis complex were identified and differentiated by using PCR-RFLP analysis. The isolates were then analyzed to determine their susceptibility profile to fluconazole (FLU), itraconazole (ITC) and amphotericin B. The minimum inhibitory concentration (MIC) results were analyzed according to the standard CLSI guide. Results: All of isolates were identified as C. parapsilosis. No C. metapsilosis and C. orthopsilosis strains were found. Evaluation of the antifungal susceptibility profile showed that only three (2.5%) C. parapsilosis were resistant to fluconazole, three (2.5%) C. parapsilosis were resistant to itraconazole and two (1.7%) C. parapsilosis were amphotericin B resistant. Conclusion: Profiles in clinical isolates of C. parapsilosis can provide important information for the control of antifungal resistance as well as distribution and susceptibility profiles in populations. PMID:27141494

  9. The effect of various antifungal agents on aflatoxin production and growth characteristics of Aspergillus parasiticus and Aspergillus flavus in liquid medium.

    PubMed

    Stewart, R G; Wyatt, R D; Ashmore, M D

    1977-09-01

    Various antifungal agents were added to a medium of 2% yeast extract-4% sucrose. Spores of a toxigenic strain of Aspergillus parasiticus were inoculated into the medium and incubated at 26 degrees C. for 10 days. Growth of the mold and aflatoxin formation were monitored every 48 hours during the experiment. Of the antifungal agents evaluated, propionic acid and crystal violet were the most effective compounds in retarding mold growth. Propionic acid was fungicidal at concentrations greater than 3.0 microgram/ml. whereas crystal violet exhibited a mold retarding activity at levels greater than 2,0 microgram/ml. Crystal violet retarded the growth rate of the mold during the initial stages of growth, however, this retardation was overcome after 10 days of incubation. Crystal violet also retarded aflatoxin production and sporulation of Aspergillus parasiticus; however, aflatoxin production was the most sensitive parameter. A survey involving 12 toxigenic isolates of A. parasiticus and A. flavus indicated that these species vary markedly in susceptibility to crystal violet. PMID:415299

  10. Azole fungicides - understanding resistance mechanisms in agricultural fungal pathogens.

    PubMed

    Price, Claire L; Parker, Josie E; Warrilow, Andrew G S; Kelly, Diane E; Kelly, Steven L

    2015-08-01

    Plant fungal pathogens can have devastating effects on a wide range of crops, including cereals and fruit (such as wheat and grapes), causing losses in crop yield, which are costly to the agricultural economy and threaten food security. Azole antifungals are the treatment of choice; however, resistance has arisen against these compounds, which could lead to devastating consequences. Therefore, it is important to understand how these fungicides are used and how the resistance arises in order to tackle the problem fully. Here, we give an overview of the problem and discuss the mechanisms that mediate azole resistance in agriculture (point mutations in the CYP51 amino acid sequence, overexpression of the CYP51 enzyme and overexpression of genes encoding efflux pump proteins). © 2015 Society of Chemical Industry. PMID:25914201

  11. Clotrimazole as a Potent Agent for Treating the Oomycete Fish Pathogen Saprolegnia parasitica through Inhibition of Sterol 14α-Demethylase (CYP51)

    PubMed Central

    Warrilow, Andrew G. S.; Hull, Claire M.; Rolley, Nicola J.; Parker, Josie E.; Nes, W. David; Smith, Stephen N.

    2014-01-01

    A candidate CYP51 gene encoding sterol 14α-demethylase from the fish oomycete pathogen Saprolegnia parasitica (SpCYP51) was identified based on conserved CYP51 residues among CYPs in the genome. It was heterologously expressed in Escherichia coli, purified, and characterized. Lanosterol, eburicol, and obtusifoliol bound to purified SpCYP51 with similar binding affinities (Ks, 3 to 5 μM). Eight pharmaceutical and six agricultural azole antifungal agents bound tightly to SpCYP51, with posaconazole displaying the highest apparent affinity (Kd, ≤3 nM) and prothioconazole-desthio the lowest (Kd, ∼51 nM). The efficaciousness of azole antifungals as SpCYP51 inhibitors was confirmed by 50% inhibitory concentrations (IC50s) of 0.17 to 2.27 μM using CYP51 reconstitution assays. However, most azole antifungal agents were less effective at inhibiting S. parasitica, Saprolegnia diclina, and Saprolegnia ferax growth. Epoxiconazole, fluconazole, itraconazole, and posaconazole failed to inhibit Saprolegnia growth (MIC100, >256 μg ml−1). The remaining azoles inhibited Saprolegnia growth only at elevated concentrations (MIC100 [the lowest antifungal concentration at which growth remained completely inhibited after 72 h at 20°C], 16 to 64 μg ml−1) with the exception of clotrimazole, which was as potent as malachite green (MIC100, ∼1 μg ml−1). Sterol profiles of azole-treated Saprolegnia species confirmed that endogenous CYP51 enzymes were being inhibited with the accumulation of lanosterol in the sterol fraction. The effectiveness of clotrimazole against SpCYP51 activity (IC50, ∼1 μM) and the concentration inhibiting the growth of Saprolegnia species in vitro (MIC100, ∼1 to 2 μg ml−1) suggest that clotrimazole could be used against Saprolegnia infections, including as a preventative measure by pretreatment of fish eggs, and for freshwater-farmed fish as well as in leisure activities. PMID:25085484

  12. Clotrimazole as a potent agent for treating the oomycete fish pathogen Saprolegnia parasitica through inhibition of sterol 14α-demethylase (CYP51).

    PubMed

    Warrilow, Andrew G S; Hull, Claire M; Rolley, Nicola J; Parker, Josie E; Nes, W David; Smith, Stephen N; Kelly, Diane E; Kelly, Steven L

    2014-10-01

    A candidate CYP51 gene encoding sterol 14α-demethylase from the fish oomycete pathogen Saprolegnia parasitica (SpCYP51) was identified based on conserved CYP51 residues among CYPs in the genome. It was heterologously expressed in Escherichia coli, purified, and characterized. Lanosterol, eburicol, and obtusifoliol bound to purified SpCYP51 with similar binding affinities (Ks, 3 to 5 μM). Eight pharmaceutical and six agricultural azole antifungal agents bound tightly to SpCYP51, with posaconazole displaying the highest apparent affinity (Kd, ≤3 nM) and prothioconazole-desthio the lowest (Kd, ∼51 nM). The efficaciousness of azole antifungals as SpCYP51 inhibitors was confirmed by 50% inhibitory concentrations (IC50s) of 0.17 to 2.27 μM using CYP51 reconstitution assays. However, most azole antifungal agents were less effective at inhibiting S. parasitica, Saprolegnia diclina, and Saprolegnia ferax growth. Epoxiconazole, fluconazole, itraconazole, and posaconazole failed to inhibit Saprolegnia growth (MIC100, >256 μg ml(-1)). The remaining azoles inhibited Saprolegnia growth only at elevated concentrations (MIC100 [the lowest antifungal concentration at which growth remained completely inhibited after 72 h at 20°C], 16 to 64 μg ml(-1)) with the exception of clotrimazole, which was as potent as malachite green (MIC100, ∼1 μg ml(-1)). Sterol profiles of azole-treated Saprolegnia species confirmed that endogenous CYP51 enzymes were being inhibited with the accumulation of lanosterol in the sterol fraction. The effectiveness of clotrimazole against SpCYP51 activity (IC50, ∼1 μM) and the concentration inhibiting the growth of Saprolegnia species in vitro (MIC100, ∼1 to 2 μg ml(-1)) suggest that clotrimazole could be used against Saprolegnia infections, including as a preventative measure by pretreatment of fish eggs, and for freshwater-farmed fish as well as in leisure activities. PMID:25085484

  13. New class of 2-aryl-6-chloro-3,4-dihydroisoquinolinium salts as potential antifungal agents for plant protection: synthesis, bioactivity and structure-activity relationships.

    PubMed

    Yang, Rui; Gao, Zhao-Feng; Zhao, Jie-Yu; Li, Wei-Bo; Zhou, Le; Miao, Fang

    2015-02-25

    Thirty-four new 2-aryl-6-chloro-3,4-dihydroisoquinolin-2-ium bromides were synthesized, and their structures were elucidated by spectroscopic analysis. Antifungal activities against Alternaria alternate, Curvularia lunata and Valsa mali were evaluated by the mycelium linear growth rate method. SAR was discussed also. All compounds showed some activity against each of the fungi at 25 μg/mL. Compared to azoxystrobin, a commercial fungicide, 31 out of 34 test compounds showed higher inhibition rates against C. lunata and 10 were more effective against A. alternate and V. mali. Compounds 5-4, 5-2 and 5-34 showed the highest activity against A. alternate (EC50 = 10.3 μg/mL), C. lunata (EC50 = 4.6 μg/mL) and V. mali (EC50 = 3.9 μg/mL), respectively, superior to azoxystrobin (EC50 = 12.8, 71.9, 37.2 μg/mL). Compound 5-4 displayed good activities against each of the fungi with EC50 of 10.3, 4.7, and 18.0 μg/mL while 5-34 displayed excellent activities against V. mali (EC50 = 3.9 μg/mL) and C. lunata (EC50 = 5.8 μg/mL). The SAR showed that the type and position of substituents on the C-ring had significant effects on the activity. Generally, the presence of 2'-F, 4'-F or 2'-CH3 could significantly improve the activities, whereas OH, OMe, NO2 or CF3 groups decreased the activities. Thus, it was concluded that the present research provided a new series of 2-aryl-6-chloro-3,4-dihydroisoquinolin-2-iums with excellent antifungal potency, and the results were of importance for the structure optimization design, synthesis and development of more potent isoquinoline antifungal agents. PMID:25645055

  14. Genomic Context of Azole Resistance Mutations in Aspergillus fumigatus Determined Using Whole-Genome Sequencing

    PubMed Central

    Abdolrasouli, Alireza; Rhodes, Johanna; Beale, Mathew A.; Hagen, Ferry; Rogers, Thomas R.; Chowdhary, Anuradha; Meis, Jacques F.

    2015-01-01

    ABSTRACT A rapid and global emergence of azole resistance has been observed in the pathogenic fungus Aspergillus fumigatus over the past decade. The dominant resistance mechanism appears to be of environmental origin and involves mutations in the cyp51A gene, which encodes a protein targeted by triazole antifungal drugs. Whole-genome sequencing (WGS) was performed for high-resolution single-nucleotide polymorphism (SNP) analysis of 24 A. fumigatus isolates, including azole-resistant and susceptible clinical and environmental strains obtained from India, the Netherlands, and the United Kingdom, in order to assess the utility of WGS for characterizing the alleles causing resistance. WGS analysis confirmed that TR34/L98H (a mutation comprising a tandem repeat [TR] of 34 bases in the promoter of the cyp51A gene and a leucine-to-histidine change at codon 98) is the sole mechanism of azole resistance among the isolates tested in this panel of isolates. We used population genomic analysis and showed that A. fumigatus was panmictic, with as much genetic diversity found within a country as is found between continents. A striking exception to this was shown in India, where isolates are highly related despite being isolated from both clinical and environmental sources across >1,000 km; this broad occurrence suggests a recent selective sweep of a highly fit genotype that is associated with the TR34/L98H allele. We found that these sequenced isolates are all recombining, showing that azole-resistant alleles are segregating into diverse genetic backgrounds. Our analysis delineates the fundamental population genetic parameters that are needed to enable the use of genome-wide association studies to identify the contribution of SNP diversity to the generation and spread of azole resistance in this medically important fungus. PMID:26037120

  15. In Vitro Interactions between Non-Steroidal Anti-Inflammatory Drugs and Antifungal Agents against Planktonic and Biofilm Forms of Trichosporon asahii

    PubMed Central

    Cong, Lin; Lu, Xuelian

    2016-01-01

    Increasing drug resistance has brought enormous challenges to the management of Trichosporon spp. infections. The in vitro antifungal activities of non-steroidal anti-inflammatory drugs (NSAIDs) against Candida spp. and Cryptococcus spp. were recently discovered. In the present study, the in vitro interactions between three NSAIDs (aspirin, ibuprofen and diclofenac sodium) and commonly used antifungal agents (fluconazole, itraconazole, voriconazole, caspofungin and amphotericin B) against planktonic and biofilm cells of T. asahii were evaluated using the checkerboard microdilution method. The spectrophotometric method and the XTT reduction assay were used to generate data on biofilm cells. The fractional inhibitory concentration index (FICI) and the ΔE model were compared to interpret drug interactions. Using the FICI, the highest percentages of synergistic effects against planktonic cells (86.67%) and biofilm cells (73.33%) were found for amphotericin B/ibuprofen, and caspofungin/ibuprofen showed appreciable percentages (73.33% for planktonic form and 60.00% for biofilm) as well. We did not observe antagonism. The ΔE model gave consistent results with FICI (86.67%). Our findings suggest that amphotericin B/ibuprofen and caspofungin/ibuprofen combinations have potential effects against T. asahii. Further in vivo and animal studies to investigate associated mechanisms need to be conducted. PMID:27275608

  16. Azole resistance in Candida spp. isolated from Catú Lake, Ceará, Brazil: an efflux-pump-mediated mechanism

    PubMed Central

    Brilhante, Raimunda S.N.; Paiva, Manoel A.N.; Sampaio, Célia M.S.; Castelo-Branco, Débora S.C.M.; Teixeira, Carlos E.C.; de Alencar, Lucas P.; Bandeira, Tereza J.P.G.; Monteiro, André J.; Cordeiro, Rossana A.; Pereira-Neto, Waldemiro A.; Sidrim, José J.C.; Moreira, José L.B.; Rocha, Marcos F.G.

    2016-01-01

    Since, there is no study reporting the mechanism of azole resistance among yeasts isolated from aquatic environments; the present study aims to investigate the occurrence of antifungal resistance among yeasts isolated from an aquatic environment, and assess the efflux-pump activity of the azole-resistant strains to better understand the mechanism of resistance for this group of drugs. For this purpose, monthly water and sediment samples were collected from Catú Lake, Ceará, Brazil, from March 2011 to February 2012. The obtained yeasts were identified based on morphological and biochemical characteristics. Of the 46 isolates, 37 were Candida spp., 4 were Trichosporon asahii, 3 were Cryptococcus laurentii, 1 Rhodotorula mucilaginosa, and 1 was Kodamaea ohmeri. These isolates were subjected to broth microdilution assay with amphotericin B, itraconazole, and fluconazole, according to the methodology standardized by the Clinical and Laboratory Standards Institute (CLSI). The minimum inhibitory concentrations (MICs) of amphotericin B, itraconazole, and fluconazole were 0.03125–2 μg/mL, 0.0625 to ≥16 μg/mL, and 0.5 to ≥64 μg/mL, respectively, and 13 resistant azole-resistant Candida isolates were detected. A reduction in the azole MICs leading to the phenotypical reversal of the azole resistance was observed upon addition of efflux-pump inhibitors. These findings suggest that the azole resistance among environmental Candida spp. is most likely associated with the overexpression of efflux-pumps. PMID:26887224

  17. Current trends in outwitting resistance development in Candida infections through photodynamic and short peptide therapies: a strategic-shift from conventional antifungal agents.

    PubMed

    Louis, Bengyella; Waikhom, Sayanika Devi; Atadja, Peter W

    2016-01-01

    Disequilibrium in the human debilitated immune system favors proliferation of invasive Candida species, a major therapeutic challenge due to development of resistance to several conventional antifungal agents (CAA) worldwide. Multiple mutations observed at specific loci that are targets for CAA are recognized as sources of drug resistance. This has prompted a shift from CAA, to diverse combination therapies, photodynamic and short peptide therapies capable of triggering specific apoptotic reactions within candidal cells. In this review, new designs and combination of short peptide (SP) with CAA as well as current application of photodynamic inactivation (PDI) against Candida species geared at generating reactive species of oxygen (ROS) and nitrogen (RNS) are discussed. It is observed that oxidative and nitrosative stresses provides a superior broad candidacidal effects for eradication of drug-resistant Candida species. The mechanism and limitations in these strategic approaches over CAA is also discussed. PMID:26822688

  18. In vitro susceptibility of e.faecalis and c.albicans isolates from apical periodontitis to common antimicrobial agents, antibiotics and antifungal medicaments

    PubMed Central

    Yoldas, Oguz; Yilmaz, Sehnaz; Akcimen, Beril; Seydaoglu, Gulsah; Kipalev, Arzu; Koksal, Fatih

    2012-01-01

    The aim of this study was to evaluate in vitro antimicrobial activity of 4 antibiotic agents (for E.faecalis) and 4 antifungal agents (for C.albicans) by agar dilution method. Additionally, modified strip diffusion method was used for detection of in vitro antimicrobial activities of 5% NaOCl, 2.5% NaOCl, 17% EDTA and 2% CHX and agar diffusion method for detection of in vitro susceptibilities of three intracanal medicaments for 18 E.faecalis and 18 C.albicans isolates from primary and secondary root canal infection. Isolates were recovered from 231 endodontic samples of patients, with the need of root canal treatment and retreatment. All tested E.faecalis isolates showed resistance to antibiotics. For irrigation solutions, 2% CHX was more effective in eliminating E.faecalis but 5% NaOCl showed larger inhibition zone than 2.5% NaOCl, 17% EDTA and 2% CHX. For intracanal medication, Ca(OH)2-CHX worked efficiently in killing E.faecalis isolates compared to Ca(OH)2-Steril saline solution, Ca(OH)2-Glycerin. For C.albicans, 18 isolates were susceptible to amphotericin B, nistatin, fluconazole but showed resistance to ketoconazole. 5% NaOCl was more effective in eliminating and produced larger inhibition zone compared to 2.5% NaOCl, 17% EDTA and 2% CHX. Ca(OH)2-Glycerin intracanal medication was better in eliminating C.albicans isolates and produced larger inhibition zone compared to other Ca(OH)2 medicaments. Key words:E.faecalis, C.albicans, antimicrobial, antibiotic, antifungal. PMID:24558517

  19. In vivo toxicity of a new antifungal agent 2,4-dithiophenoxy-1-iodo-4-bromo benzene: a follow up on our in vitro study.

    PubMed

    Kılıç Süloğlu, Aysun; Koçkaya, Evrim; Karacaoğlu, Elif; Selmanoğlu, Güldeniz; Loğoğlu, Elif

    2015-03-01

    Triazole fungicide fluconazole has become the most widely used antifungal agent in the world, mainly because of its ability to penetrate well into body fluids and tissues. However, it has been reported to interact with many drugs and because of its common use, the risk of resistance to fluconazole increases. This calls for new anti-fungal drugs that would be able to replace it. In 2006, a new thialo benzene derivative - 2,4-dithiophenoxy-1-iodo-4-bromo benzene (C18H12S2IBr) - was synthesised with a carbon backbone similar to fluconazole, and, according to the early in vitro tests, much greater efficiency. Followed an in vitro test of its cytotoxicity, in which the new drug showed promising results as an alternative to fluconazole. The aim of this study was take the next step and test C18H12S2IBr toxicity in vivo. We opted for a four-week test on Wistar rats, in which the new antifungal agent was orally applied at doses two and a half and five times lower than those of fluconazole. There were no changes in daily food and water consumption, but weight gain in female rats and relative organ weights changed in the treated groups, pointing to sex-related differences in drug metabolism and effects. Fluconazole significantly increased leukocytes and lowered neutrophils whereas C18H12S2IBr did not, while other haematological changes in respect to the vehicle control were similar between the treated groups. Differences in cytochrome c in the liver and kidney suggested greater apoptotic effect of the new drug, but interpretation remains inconclusive, considering that other key indicators (biochemistry and histopathology) do not support greater toxicity. Considering that C18H12S2IBr is more active at lower concentrations and has comparable toxic effects to fluconazole in rats, this new compound shows some promise in the treatment of fungal infections. Future, more detailed animal studies are needed, that will include drug interactions and molecular toxicity pathways. If the

  20. Evaluation of vaginal antifungal formulations in vivo.

    PubMed Central

    McRipley, R. J.; Erhard, P. J.; Schwind, R. A.; Whitney, R. R.

    1979-01-01

    Relatively simple and rapid procedures have been developed for evaluating the local efficacy of vaginal antifungal agents in vivo in a vaginal candidiasis model in ovariectomized rats. The results of this investigation indicate that the model and methods described are quite suitable for screening potential antifungal substances and for assessing the chemotherapeutic effectiveness of new antifungal agents and formulations before carrying out clinical studies. PMID:392480

  1. The impact of azole resistance on aspergillosis guidelines.

    PubMed

    Georgiadou, Sarah P; Kontoyiannis, Dimitrios P

    2012-12-01

    Azole resistance in Aspergillus species may be on the rise, with significant potential implications for the management of invasive aspergillosis. The main mechanism of azole resistance in Aspergillus fumigatus is via alterations of the target enzyme CYP51A. Such azole resistance is either primary or secondary (in the setting of prior azole exposure) and can be derived either from single or multiple mutations. Irrespective of the amino acid substitution type in CYP51A, azole-resistant Aspergillus isolates are always itraconazole resistant. There is significant variability among studies and centers in the prevalence of azole resistance, and this is a multifactorial issue. Nevertheless, the exact frequency of azole resistance is unknown, in part because of the low culturability of the fungus in patients with aspergillosis. This work aims to provide an overview of the current knowledge in Aspergillus azole resistance and raises questions for future research and practical implications in the management of aspergillosis. PMID:23231710

  2. Genetic dissection of azole resistance mechanisms in Candida albicans and their validation in a mouse model of disseminated infection.

    PubMed

    MacCallum, Donna M; Coste, Alix; Ischer, Françoise; Jacobsen, Mette D; Odds, Frank C; Sanglard, Dominique

    2010-04-01

    Principal mechanisms of resistance to azole antifungals include the upregulation of multidrug transporters and the modification of the target enzyme, a cytochrome P450 (Erg11) involved in the 14alpha-demethylation of ergosterol. These mechanisms are often combined in azole-resistant Candida albicans isolates recovered from patients. However, the precise contributions of individual mechanisms to C. albicans resistance to specific azoles have been difficult to establish because of the technical difficulties in the genetic manipulation of this diploid species. Recent advances have made genetic manipulations easier, and we therefore undertook the genetic dissection of resistance mechanisms in an azole-resistant clinical isolate. This isolate (DSY296) upregulates the multidrug transporter genes CDR1 and CDR2 and has acquired a G464S substitution in both ERG11 alleles. In DSY296, inactivation of TAC1, a transcription factor containing a gain-of-function mutation, followed by sequential replacement of ERG11 mutant alleles with wild-type alleles, restored azole susceptibility to the levels measured for a parent azole-susceptible isolate (DSY294). These sequential genetic manipulations not only demonstrated that these two resistance mechanisms were those responsible for the development of resistance in DSY296 but also indicated that the quantitative level of resistance as measured in vitro by MIC determinations was a function of the number of genetic resistance mechanisms operating in any strain. The engineered strains were also tested for their responses to fluconazole treatment in a novel 3-day model of invasive C. albicans infection of mice. Fifty percent effective doses (ED(50)s) of fluconazole were highest for DSY296 and decreased proportionally with the sequential removal of each resistance mechanism. However, while the fold differences in ED(50) were proportional to the fold differences in MICs, their magnitude was lower than that measured in vitro and depended on

  3. Intermolecular interaction of voriconazole analogues with model membrane by DSC and NMR, and their antifungal activity using NMR based metabolic profiling.

    PubMed

    Kalamkar, Vaibhav; Joshi, Mamata; Borkar, Varsha; Srivastava, Sudha; Kanyalkar, Meena

    2013-11-01

    The development of novel antifungal agents with high susceptibility and increased potency can be achieved by increasing their overall lipophilicity. To enhance the lipophilicity of voriconazole, a second generation azole antifungal agent, we have synthesized its carboxylic acid ester analogues, namely p-methoxybenzoate (Vpmb), toluate (Vtol), benzoate (Vbz) and p-nitrobenzoate (Vpnb). The intermolecular interactions of these analogues with model membrane have been investigated using nuclear magnetic resonance (NMR) and differential scanning calorimetric (DSC) techniques. The results indicate varying degree of changes in the membrane bilayer's structural architecture and physico-chemical characteristics which possibly can be correlated with the antifungal effects via fungal membrane. Rapid metabolite profiling of chemical entities using cell preparations is one of the most important steps in drug discovery. We have evaluated the effect of synthesized analogues on Candida albicans. The method involves real time (1)H NMR measurement of intact cells monitoring NMR signals from fungal metabolites which gives Metabolic End Point (MEP). This is then compared with Minimum Inhibitory Concentration (MIC) determined using conventional methods. Results indicate that one of the synthesized analogues, Vpmb shows reasonably good activity. PMID:24012381

  4. Acquired antifungal drug resistance in Aspergillus fumigatus: epidemiology and detection.

    PubMed

    Howard, Susan Julie; Arendrup, Maiken Cavling

    2011-04-01

    Voriconazole is the recommended agent for invasive aspergillosis, with lipid amphotericin B or caspofungin as second line treatment choices. Being the only agents available in oral formulation, azoles are used in chronic infections and often over longer time periods. In addition to being used in clinical medicine, azoles are employed extensively in agriculture. Azole-resistant Aspergillus has been isolated in azole naïve patients, in azole exposed patients and in the environment. The primary underlying mechanism of resistance is as a result of alterations in the cyp51A target gene, with a variety of mutations found in clinical isolates but just one identified in a environmental strain (a point mutation at codon 98 accompanied by a tandem repeat in the promoter region). Much less is currently known about echinocandin resistance in Aspergillus, in part because susceptibility testing is not routinely performed and because the methods suffer from technical difficulties and suboptimal reproducibility. Clinical breakthrough cases have been reported however, and resistance has been confirmed in vivo. In this paper we review the current knowledge on epidemiology, susceptibility testing and underlying mechanisms involved in azole and echinocandin resistance in Aspergillus. PMID:20795765

  5. Prospective multicenter international surveillance of azole resistance in Aspergillus fumigatus.

    PubMed

    van der Linden, J W M; Arendrup, M C; Warris, A; Lagrou, K; Pelloux, H; Hauser, P M; Chryssanthou, E; Mellado, E; Kidd, S E; Tortorano, A M; Dannaoui, E; Gaustad, P; Baddley, J W; Uekötter, A; Lass-Flörl, C; Klimko, N; Moore, C B; Denning, D W; Pasqualotto, A C; Kibbler, C; Arikan-Akdagli, S; Andes, D; Meletiadis, J; Naumiuk, L; Nucci, M; Melchers, W J G; Verweij, P E

    2015-06-01

    To investigate azole resistance in clinical Aspergillus isolates, we conducted prospective multicenter international surveillance. A total of 3,788 Aspergillus isolates were screened in 22 centers from 19 countries. Azole-resistant A. fumigatus was more frequently found (3.2% prevalence) than previously acknowledged, causing resistant invasive and noninvasive aspergillosis and severely compromising clinical use of azoles. PMID:25988348

  6. In Vitro Biochemical Study of CYP51-Mediated Azole Resistance in Aspergillus fumigatus

    PubMed Central

    Warrilow, Andrew G. S.; Parker, Josie E.; Price, Claire L.; Nes, W. David

    2015-01-01

    The incidence of triazole-resistant Aspergillus infections is increasing worldwide, often mediated through mutations in the CYP51A amino acid sequence. New classes of azole-based drugs are required to combat the increasing resistance to existing triazole therapeutics. In this study, a CYP51 reconstitution assay is described consisting of eburicol, purified recombinant Aspergillus fumigatus CPR1 (AfCPR1), and Escherichia coli membrane suspensions containing recombinant A. fumigatus CYP51 proteins, allowing in vitro screening of azole antifungals. Azole-CYP51 studies determining the 50% inhibitory concentration (IC50) showed that A. fumigatus CYP51B (Af51B IC50, 0.50 μM) was 34-fold more susceptible to inhibition by fluconazole than A. fumigatus CYP51A (Af51A IC50, 17 μM) and that Af51A and Af51B were equally susceptible to inhibition by voriconazole, itraconazole, and posaconazole (IC50s of 0.16 to 0.38 μM). Af51A-G54W and Af51A-M220K enzymes were 11- and 15-fold less susceptible to inhibition by itraconazole and 30- and 8-fold less susceptible to inhibition by posaconazole than wild-type Af51A, confirming the azole-resistant phenotype of these two Af51A mutations. Susceptibility to voriconazole of Af51A-G54W and Af51A-M220K was only marginally lower than that of wild-type Af51A. Susceptibility of Af51A-L98H to inhibition by voriconazole, itraconazole, and posaconazole was only marginally lower (less than 2-fold) than that of wild-type Af51A. However, Af51A-L98H retained 5 to 8% residual activity in the presence of 32 μM triazole, which could confer azole resistance in A. fumigatus strains that harbor the Af51A-L98H mutation. The AfCPR1/Af51 assay system demonstrated the biochemical basis for the increased azole resistance of A. fumigatus strains harboring G54W, L98H, and M220K Af51A point mutations. PMID:26459890

  7. In Vitro Biochemical Study of CYP51-Mediated Azole Resistance in Aspergillus fumigatus.

    PubMed

    Warrilow, Andrew G S; Parker, Josie E; Price, Claire L; Nes, W David; Kelly, Steven L; Kelly, Diane E

    2015-12-01

    The incidence of triazole-resistant Aspergillus infections is increasing worldwide, often mediated through mutations in the CYP51A amino acid sequence. New classes of azole-based drugs are required to combat the increasing resistance to existing triazole therapeutics. In this study, a CYP51 reconstitution assay is described consisting of eburicol, purified recombinant Aspergillus fumigatus CPR1 (AfCPR1), and Escherichia coli membrane suspensions containing recombinant A. fumigatus CYP51 proteins, allowing in vitro screening of azole antifungals. Azole-CYP51 studies determining the 50% inhibitory concentration (IC50) showed that A. fumigatus CYP51B (Af51B IC50, 0.50 μM) was 34-fold more susceptible to inhibition by fluconazole than A. fumigatus CYP51A (Af51A IC50, 17 μM) and that Af51A and Af51B were equally susceptible to inhibition by voriconazole, itraconazole, and posaconazole (IC50s of 0.16 to 0.38 μM). Af51A-G54W and Af51A-M220K enzymes were 11- and 15-fold less susceptible to inhibition by itraconazole and 30- and 8-fold less susceptible to inhibition by posaconazole than wild-type Af51A, confirming the azole-resistant phenotype of these two Af51A mutations. Susceptibility to voriconazole of Af51A-G54W and Af51A-M220K was only marginally lower than that of wild-type Af51A. Susceptibility of Af51A-L98H to inhibition by voriconazole, itraconazole, and posaconazole was only marginally lower (less than 2-fold) than that of wild-type Af51A. However, Af51A-L98H retained 5 to 8% residual activity in the presence of 32 μM triazole, which could confer azole resistance in A. fumigatus strains that harbor the Af51A-L98H mutation. The AfCPR1/Af51 assay system demonstrated the biochemical basis for the increased azole resistance of A. fumigatus strains harboring G54W, L98H, and M220K Af51A point mutations. PMID:26459890

  8. Novel point mutations in the ERG11 gene in clinical isolates of azole resistant Candida species

    PubMed Central

    Silva, Danielly Beraldo dos Santos; Rodrigues, Luana Mireli Carbonera; de Almeida, Adriana Araújo; de Oliveira, Kelly Mari Pires; Grisolia/, Alexéia Barufatti

    2016-01-01

    The azoles are the class of medications most commonly used to fight infections caused by Candida sp. Typically, resistance can be attributed to mutations in ERG11 gene (CYP51) which encodes the cytochrome P450 14α-demethylase, the primary target for the activity of azoles. The objective of this study was to identify mutations in the coding region of theERG11 gene in clinical isolates of Candidaspecies known to be resistant to azoles. We identified three new synonymous mutations in the ERG11 gene in the isolates of Candida glabrata (C108G, C423T and A1581G) and two new nonsynonymous mutations in the isolates of Candida krusei - A497C (Y166S) and G1570A (G524R). The functional consequence of these nonsynonymous mutations was predicted using evolutionary conservation scores. The G524R mutation did not have effect on 14α-demethylase functionality, while the Y166S mutation was found to affect the enzyme. This observation suggests a possible link between the mutation and dose-dependent sensitivity to voriconazole in the clinical isolate of C. krusei. Although the presence of the Y166S in phenotype of reduced azole sensitivity observed in isolate C. kruseidemands investigation, it might contribute to the search of new therapeutic agents against resistant Candida isolates. PMID:26982177

  9. Novel point mutations in the ERG11 gene in clinical isolates of azole resistant Candida species.

    PubMed

    Silva, Danielly Beraldo dos Santos; Rodrigues, Luana Mireli Carbonera; Almeida, Adriana Araújo de; Oliveira, Kelly Mari Pires de; Grisolia, Alexéia Barufatti

    2016-03-01

    The azoles are the class of medications most commonly used to fight infections caused by Candida sp. Typically, resistance can be attributed to mutations in ERG11 gene (CYP51) which encodes the cytochrome P450 14α-demethylase, the primary target for the activity of azoles. The objective of this study was to identify mutations in the coding region of theERG11 gene in clinical isolates of Candida species known to be resistant to azoles. We identified three new synonymous mutations in the ERG11 gene in the isolates of Candida glabrata (C108G, C423T and A1581G) and two new nonsynonymous mutations in the isolates of Candida krusei--A497C (Y166S) and G1570A (G524R). The functional consequence of these nonsynonymous mutations was predicted using evolutionary conservation scores. The G524R mutation did not have effect on 14α-demethylase functionality, while the Y166S mutation was found to affect the enzyme. This observation suggests a possible link between the mutation and dose-dependent sensitivity to voriconazole in the clinical isolate of C. krusei. Although the presence of the Y166S in phenotype of reduced azole sensitivity observed in isolate C. krusei demands investigation, it might contribute to the search of new therapeutic agents against resistant Candida isolates. PMID:26982177

  10. cis-Acting elements within the Candida albicans ERG11 promoter mediate the azole response through transcription factor Upc2p.

    PubMed

    Oliver, Brian G; Song, Jia L; Choiniere, Jake H; White, Theodore C

    2007-12-01

    The azole antifungal drugs are used to treat infections caused by Candida albicans and other fungi. These drugs interfere with the biosynthesis of ergosterol, the major sterol in fungal cells, by inhibiting an ergosterol biosynthetic enzyme, lanosterol 14 alpha-demethylase, encoded by the ERG11 gene. In vitro, these drugs as well as other ergosterol biosynthesis inhibitors increase ERG11 mRNA expression by activation of the ERG11 promoter. The signal for this activation most likely is the depletion of ergosterol, the end product of the pathway. To identify cis-acting regulatory elements that mediate this activation, ERG11 promoter fragments have been fused to the luciferase reporter gene from Renilla reniformis. Promoter deletions and linker scan mutations localized the region important for azole induction to a segment from bp -224 to -251 upstream of the start codon, specifically two 7-bp sequences separated by 13 bp. These sequences form an imperfect inverted repeat. The region is recognized by the transcription factor Upc2p and functions as an enhancer of transcription, as it can be placed upstream of a heterologous promoter in either direction, resulting in the azole induction of that promoter. The promoter constructs are not azole inducible in the upc2/upc2 homozygous deletion, demonstrating that Upc2p controls the azole induction of ERG11. These results identify an azole-responsive enhancer element (ARE) in the ERG11 promoter that is controlled by the Upc2p transcription factor. No other ARE is present in the promoter. Thus, this ARE and Upc2p are necessary and sufficient for azole induction of ERG11. PMID:17951521

  11. Antifungal hydrogels

    PubMed Central

    Zumbuehl, Andreas; Ferreira, Lino; Kuhn, Duncan; Astashkina, Anna; Long, Lisa; Yeo, Yoon; Iaconis, Tiffany; Ghannoum, Mahmoud; Fink, Gerald R.; Langer, Robert; Kohane, Daniel S.

    2007-01-01

    Fungi are increasingly identified as major pathogens in bloodstream infections, often involving indwelling devices. Materials with antifungal properties may provide an important deterrent to these infections. Here we describe amphogel, a dextran-based hydrogel into which amphotericin B is adsorbed. Amphogel kills fungi within 2 h of contact and can be reused for at least 53 days without losing its effectiveness against Candida albicans. The antifungal material is biocompatible in vivo and does not cause hemolysis in human blood. Amphogel inoculated with C. albicans and implanted in mice prevents fungal infection. Amphogel also mitigates fungal biofilm formation. An antifungal matrix with these properties could be used to coat a variety of medical devices such as catheters as well as industrial surfaces. PMID:17664427

  12. Controlled nail delivery of a novel lipophilic antifungal agent using various modern drug carrier systems as well as in vitro and ex vivo model systems.

    PubMed

    Naumann, Sandy; Meyer, Jean-Philippe; Kiesow, Andreas; Mrestani, Yahya; Wohlrab, Johannes; Neubert, Reinhard H H

    2014-04-28

    The penetration behavior into human nails and animal hoof membranes of a novel antifungal agent (EV-086K) for the treatment of onychomycosis was investigated in this study. The new drug provides a high lipophilicity which is adverse for penetration into nails. Therefore, four different formulations were developed, with particular focus on a colloidal carrier system (CCS) due to its penetration enhancing properties. On the one hand, ex vivo penetration experiments on human nails were performed. Afterwards the human nail plates were cut by cryomicrotome in order to quantify the drug concentration in the dorsal, intermediate and ventral nail layer using high-performance liquid chromatography (HPLC) with UV detection. On the other hand, equine and bovine hoof membranes were used to determine the in vitro penetration of the drug into the acceptor compartment of an online diffusion cell coupled with Fourier transform infrared attenuated total reflectance (FTIR-ATR) spectroscopy. In combination, both results should exhibit a correlation between the EV-086K penetration behavior in human nail plates and animal hoof membranes. The investigations showed that the developed CCS could increase drug delivery through the human nail most compared to other formulations (nail lacquer, solution and hydrogel). Using animal hooves in the online diffusion cell, we were able to calculate pharmacokinetic data of the penetration process, especially diffusion and permeability coefficients. Finally, a qualitative correlation between the penetration results of human nails and equine hooves was established. PMID:24560884

  13. Tragacanth gum biopolymer as reducing and stabilizing agent in biosonosynthesis of urchin-like ZnO nanorod arrays: A low cytotoxic photocatalyst with antibacterial and antifungal properties.

    PubMed

    Ghayempour, Soraya; Montazer, Majid; Mahmoudi Rad, Mahnaz

    2016-01-20

    Tragacanth, a natural gum, has been used for centuries as emulsifier, thickener, stabilizer and binder in various fields such as food, medical and cosmetic industries. In this study, Tragacanth gum was used as a clean and natural reducing and stabilizing agent for preparation of urchin-like ZnO nanorod arrays at low-temperature using ultrasonic irradiation. The morphology and structure of urchin-like ZnO nanorod arrays was investigated by XRD, FESEM images, EDX, UV-vis and FT-IR spectroscopy. The hexagonal zinc oxide nanorods were synthesized with the average diameter of 55-80 nm and length of 240 nm. The peak appeared in 447 cm(-1) in FTIR spectra and the peak around 362.3 nm in UV-vis spectra of ZnO nanorods confirmed the successful synthesis of ZnO nanorods. The urchin-like ZnO nanorod arrays indicated a good photocatalytic activity through degradation of methylene blue with 92.2% efficiency and rate constant of 0.0027 min(-1) at 120 min. Finally, the synthesized urchin-like ZnO nanorod arrays indicated 100% antibacterial activity against S. aureus and E. coli and 93% antifungal activity against C. albicans with a low cytotoxicity. PMID:26572351

  14. Recent advances in antifungal chemotherapy.

    PubMed

    Petrikkos, George; Skiada, Anna

    2007-08-01

    For over 50 years, amphotericin B deoxycholate (AmBD) has been the 'gold standard' in antifungal chemotherapy, despite its frequent toxicities. However, improved treatment options for invasive fungal infections (IFIs) have been developed during the last 15 years. Newer antifungal agents, including less toxic lipid preparations of AmBD, triazoles and the echinocandins, have been added to our armamentarium against IFIs. Some of these newer drugs can now replace AmBD as primary therapy (e.g. caspofungin for candidiasis, voriconazole for aspergillosis), whilst others offer new therapeutic options for difficult-to-treat IFIs (e.g. posaconazole for zygomycosis, fusariosis and chromoblastomycosis). It is interesting that extended use of newer antifungals such as fluconazole, despite decreasing the mortality attributed to candidiasis, resulted in selection of species resistant to several antifungals (Candida krusei, Candida glabrata); whilst several publications suggest that prolonged use of voriconazole may expose severely immunocompromised patients to the risk of zygomycosis (breakthrough). On the other hand, the differences in the mode of action of newer antifungals such as echinocandins raise the question whether combination antifungal therapy is more effective than monotherapy. Finally, the availability of an oral formulation with excellent biosafety of several newer antifungals (e.g. posaconazole) makes them candidates for prophylactic or prolonged maintenance therapy. PMID:17524625

  15. Sterol Biosynthesis and Azole Tolerance Is Governed by the Opposing Actions of SrbA and the CCAAT Binding Complex.

    PubMed

    Gsaller, Fabio; Hortschansky, Peter; Furukawa, Takanori; Carr, Paul D; Rash, Bharat; Capilla, Javier; Müller, Christoph; Bracher, Franz; Bowyer, Paul; Haas, Hubertus; Brakhage, Axel A; Bromley, Michael J

    2016-07-01

    Azole drugs selectively target fungal sterol biosynthesis and are critical to our antifungal therapeutic arsenal. However, resistance to this class of drugs, particularly in the major human mould pathogen Aspergillus fumigatus, is emerging and reaching levels that have prompted some to suggest that there is a realistic probability that they will be lost for clinical use. The dominating class of pan-azole resistant isolates is characterized by the presence of a tandem repeat of at least 34 bases (TR34) within the promoter of cyp51A, the gene encoding the azole drug target sterol C14-demethylase. Here we demonstrate that the repeat sequence in TR34 is bound by both the sterol regulatory element binding protein (SREBP) SrbA, and the CCAAT binding complex (CBC). We show that the CBC acts complementary to SrbA as a negative regulator of ergosterol biosynthesis and show that lack of CBC activity results in increased sterol levels via transcriptional derepression of multiple ergosterol biosynthetic genes including those coding for HMG-CoA-synthase, HMG-CoA-reductase and sterol C14-demethylase. In agreement with these findings, inactivation of the CBC increased tolerance to different classes of drugs targeting ergosterol biosynthesis including the azoles, allylamines (terbinafine) and statins (simvastatin). We reveal that a clinically relevant mutation in HapE (P88L) significantly impairs the binding affinity of the CBC to its target site. We identify that the mechanism underpinning TR34 driven overexpression of cyp51A results from duplication of SrbA but not CBC binding sites and show that deletion of the 34 mer results in lack of cyp51A expression and increased azole susceptibility similar to a cyp51A null mutant. Finally we show that strains lacking a functional CBC are severely attenuated for pathogenicity in a pulmonary and systemic model of aspergillosis. PMID:27438727

  16. Sterol Biosynthesis and Azole Tolerance Is Governed by the Opposing Actions of SrbA and the CCAAT Binding Complex

    PubMed Central

    Gsaller, Fabio; Furukawa, Takanori; Carr, Paul D.; Rash, Bharat; Capilla, Javier; Müller, Christoph; Bracher, Franz; Bowyer, Paul; Haas, Hubertus; Brakhage, Axel A.; Bromley, Michael J.

    2016-01-01

    Azole drugs selectively target fungal sterol biosynthesis and are critical to our antifungal therapeutic arsenal. However, resistance to this class of drugs, particularly in the major human mould pathogen Aspergillus fumigatus, is emerging and reaching levels that have prompted some to suggest that there is a realistic probability that they will be lost for clinical use. The dominating class of pan-azole resistant isolates is characterized by the presence of a tandem repeat of at least 34 bases (TR34) within the promoter of cyp51A, the gene encoding the azole drug target sterol C14-demethylase. Here we demonstrate that the repeat sequence in TR34 is bound by both the sterol regulatory element binding protein (SREBP) SrbA, and the CCAAT binding complex (CBC). We show that the CBC acts complementary to SrbA as a negative regulator of ergosterol biosynthesis and show that lack of CBC activity results in increased sterol levels via transcriptional derepression of multiple ergosterol biosynthetic genes including those coding for HMG-CoA-synthase, HMG-CoA-reductase and sterol C14-demethylase. In agreement with these findings, inactivation of the CBC increased tolerance to different classes of drugs targeting ergosterol biosynthesis including the azoles, allylamines (terbinafine) and statins (simvastatin). We reveal that a clinically relevant mutation in HapE (P88L) significantly impairs the binding affinity of the CBC to its target site. We identify that the mechanism underpinning TR34 driven overexpression of cyp51A results from duplication of SrbA but not CBC binding sites and show that deletion of the 34 mer results in lack of cyp51A expression and increased azole susceptibility similar to a cyp51A null mutant. Finally we show that strains lacking a functional CBC are severely attenuated for pathogenicity in a pulmonary and systemic model of aspergillosis. PMID:27438727

  17. Species Distribution and In Vitro Antifungal Susceptibility of Vulvovaginal Candida Isolates in China

    PubMed Central

    Wang, Feng-Juan; Zhang, Dai; Liu, Zhao-Hui; Wu, Wen-Xiang; Bai, Hui-Hui; Dong, Han-Yu

    2016-01-01

    Background: Vulvovaginal candidiasis (VVC) was a common infection associated with lifelong harassment of woman's social and sexual life. The purpose of this study was to describe the species distribution and in vitro antifungal susceptibility of Candida species (Candida spp.) isolated from patients with VVC over 8 years. Methods: Species which isolated from patients with VVC in Peking University First Hospital were identified using chromogenic culture media. Susceptibility to common antifungal agents was determined using agar diffusion method based on CLSI M44-A2 document. SPSS software (version 14.0, Inc., Chicago, IL, USA) was used for statistical analysis, involving statistical description and Chi-square test. Results: The most common strains were Candida (C.) albicans, 80.5% (n = 1775) followed by C. glabrata, 18.1% (n = 400). Nystatin exhibited excellent activity against all species (<4% resistant [R]). Resistance to azole drugs varied among different species. C. albicans: clotrimazole (3.1% R) < fluconazole (16.6% R) < itraconazole (51.5% R) < miconazole (54.0% R); C. glabrata: miconazole (25.6% R) < clotrimazole (50.5% R) < itraconazole (61.9% R) < fluconazole (73.3% R); Candida krusei: clotrimazole (0 R) < fluconazole (57.7% R) < miconazole (73.1% R) < itraconazole (83.3% R). The susceptibility of fluconazole was noticeably decreasing among all species in the study period. Conclusions: Nystatin was the optimal choice for the treatment of VVC at present. The species distribution and in vitro antifungal susceptibility of Candida spp. isolated from patients with VVC had changed over time. PMID:27174323

  18. Development and Validation of Simple RP-HPLC Method for Intracellular Determination of Fluconazole Concentration and Its Application to the Study of Candida albicans Azole Resistance

    PubMed Central

    Davtyan, Tigran K.; Melikyan, Levon A.; Nikoyan, Nune A.; Aleksanyan, Hripsime P.; Grigoryan, Nairi G.

    2015-01-01

    Candida albicans (strains NCTC-885-653 and ATCC-10231) long-term cultivated in the presence of antifungal agent fluconazole (FLC) and classical microbiological methods for determination of minimal inhibitory concentration (MIC) were used in this study. A simple and sensitive method based on reverse-phase high-performance liquid chromatography (RP-HPLC) has been developed for the determination of FLC intracellular concentration in C. albicans using tinidazole as an internal standard. Following extraction with dichloromethane, the chromatographic separation was achieved on a Machery-Nagel EC250/2 Nucleodur-100-3 C18 column by gradient elution using the mobile phase consisting of (A) 0.01 M ammonium acetate buffer, pH = 5.00, and (B) acetonitrile. Different analytical performance parameters such as linearity, precision, accuracy, limit of quantification (LOQ), and robustness were determined according to US DHHS FDA and EMEA guidelines. The method was linear for FLC (r = 0.9999) ranging from 100 to 10000 ng/mL. The intraday and interday precisions (relative standard deviation) were within 2.79 and 2.64%, respectively, and the accuracy (relative error) was less than 2.82%. The extraction recovery ranged from 79.3 to 85.5%. The reliable method was successfully applied to C. albicans azole-resistance study and it was shown that intracellular concentration of FLC correlated with a yeast drug susceptibility profile and MIC values. PMID:26783393

  19. The potential of a fluorescent-based approach for bioassay of antifungal agents against chili anthracnose disease in Thailand.

    PubMed

    Chutrakul, Chanikul; Khaokhajorn, Pratoomporn; Auncharoen, Patchanee; Boonruengprapa, Tanapong; Mongkolporn, Orarat

    2013-01-01

    Severe chili anthracnose disease in Thailand is caused by Colletotrichum gloeosporioides and C. capsici. To discover anti-anthracnose substances we developed an efficient dual-fluorescent labeling bioassay based on a microdilution approach. Indicator strains used in the assay were constructed by integrating synthetic green fluorescent protein (sGFP) and Discosoma sp. red fluorescent protein (DsRedExp) genes into the genomes of C. gloeosporioides or C. capsici respectively. Survival of co-spore cultures in the presence of inhibitors was determined by the expression levels of these fluorescent proteins. This developed assay has high potential for utilization in the investigation of selective inhibition activity to either one of the pathogens as well as the broad-range inhibitory effect against both pathogens. The value of using the dual-fluorescent assay is rapid, reliable, and consistent identification of anti-anthracnose agents. Most of all, the assay enables the identification of specific inhibitors under the co-cultivation condition. PMID:23391904

  20. Two missense mutations, E123Q and K151E, identified in the ERG11 allele of an azole-resistant isolate of Candida kefyr recovered from a stem cell transplant patient for acute myeloid leukemia.

    PubMed

    Couzigou, Célia; Gabriel, Frédéric; Biteau, Nicolas; Fitton-Ouhabi, Valérie; Noël, Thierry; Accoceberry, Isabelle

    2014-07-01

    We report on the first cloning and nucleotide sequencing of an ERG11 allele from a clinical isolate of Candida kefyr cross-resistant to azole antifungals. It was recovered from a stem cell transplant patient, in an oncohematology unit exhibiting unexpected high prevalence of C. kefyr. Two amino acid substitutions were identified: K151E, whose role in fluconazole resistance was already demonstrated in Candida albicans, and E123Q, a new substitution never described so far in azole-resistant Candida yeast. PMID:24936404

  1. Two missense mutations, E123Q and K151E, identified in the ERG11 allele of an azole-resistant isolate of Candida kefyr recovered from a stem cell transplant patient for acute myeloid leukemia

    PubMed Central

    Couzigou, Célia; Gabriel, Frédéric; Biteau, Nicolas; Fitton-Ouhabi, Valérie; Noël, Thierry; Accoceberry, Isabelle

    2014-01-01

    We report on the first cloning and nucleotide sequencing of an ERG11 allele from a clinical isolate of Candida kefyr cross-resistant to azole antifungals. It was recovered from a stem cell transplant patient, in an oncohematology unit exhibiting unexpected high prevalence of C. kefyr. Two amino acid substitutions were identified: K151E, whose role in fluconazole resistance was already demonstrated in Candida albicans, and E123Q, a new substitution never described so far in azole-resistant Candida yeast. PMID:24936404

  2. Azole Drug Import into the Pathogenic Fungus Aspergillus fumigatus

    PubMed Central

    Esquivel, Brooke D.; Smith, Adam R.; Zavrel, Martin

    2015-01-01

    The fungal pathogen Aspergillus fumigatus causes serious illness and often death when it invades tissues, especially in immunocompromised individuals. The azole class of drugs is the most commonly prescribed treatment for many fungal infections and acts on the ergosterol biosynthesis pathway. One common mechanism of acquired azole drug resistance in fungi is the prevention of drug accumulation to toxic levels in the cell. While drug efflux is a well-known resistance strategy, reduced azole import would be another strategy to maintain low intracellular azole levels. Recently, azole uptake in Candida albicans and other yeasts was analyzed using [3H]fluconazole. Defective drug import was suggested to be a potential mechanism of drug resistance in several pathogenic fungi, including Cryptococcus neoformans, Candida krusei, and Saccharomyces cerevisiae. We have adapted and developed an assay to measure azole accumulation in A. fumigatus using radioactively labeled azole drugs, based on previous work done with C. albicans. We used this assay to study the differences in azole uptake in A. fumigatus isolates under a variety of drug treatment conditions, with different morphologies and with a select mutant strain with deficiencies in the sterol uptake and biosynthesis pathway. We conclude that azole drugs are specifically selected and imported into the fungal cell by a pH- and ATP-independent facilitated diffusion mechanism, not by passive diffusion. This method of drug transport is likely to be conserved across most fungal species. PMID:25824209

  3. In Vitro Susceptibility and Trailing Growth Effect of Clinical Isolates of Candida Species to Azole Drugs

    PubMed Central

    Zomorodian, Kamiar; Bandegani, Azadeh; Mirhendi, Hossein; Pakshir, Keyvan; Alinejhad, Navvab; Poostforoush Fard, Ali

    2016-01-01

    Background: Emergence of resistance to respective antifungal drugs is a primary concern for the treatment of candidiasis. Hence, determining antifungal susceptibility of the isolated yeasts is of special importance for effective therapy. For this purpose, the clinical laboratory standard institute (CLSI) has introduced a broth microdilution method to determine minimum inhibitory concentration (MIC). However, the so-called “Trailing effect” phenomenon might sometimes pose ambiguity in the interpretation of the results. Objectives: The present study aimed to determine the in vitro susceptibility of clinical isolates of Candida against azoles and the frequency of the Trailing effect. Materials and Methods: A total of 193 Candida isolates were prospectively collected and identified through the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Using a broth microdilution test, according to the guidelines of CLSI M27-A3, antifungal susceptibilities of the isolated yeasts against Fluconazole (FLU), Itraconazole (ITR), Ketoconazole (KET) and Voriconazole (VOR) were assessed. Moreover, trailing growth was determined when a susceptible MIC was incubated for 24 hours, and turned into a resistant one after 48 hours of incubation. Results: Among the tested antifungal drugs in this study, the highest rate of resistance was observed against ITR (28.5%) followed by VOR (26.4%), FLU (20.8%) and KET (1.5%). The trailing effect was induced in 27 isolates (14.0%) by VOR, in 26 isolates (13.5%) by ITR, in 24 isolates (12.4%) by FLU, and in 19 isolates (9.8%) by KET. Conclusions: The monitoring of antifungal susceptibilities of Candida species isolated from clinical sources is highly recommended for the efficient management of patients. Moreover, the trailing effect should be taken into consideration once the interpretation of the results is intended. PMID:27127587

  4. Effect of Combined Fluoroquinolone and Azole Use on QT Prolongation in Hematology Patients

    PubMed Central

    Wilson, John W.; Estes, Lynn L.

    2013-01-01

    QTc prolongation is a risk factor for development of torsades de pointes (TdP). Combination therapy with fluoroquinolones and azoles is used in patients with hematologic malignancies for prophylaxis and treatment of infection. Both drug classes are implicated as risk factors for QTc prolongation. The cumulative effect on and incidence of QTc prolongation for this combination have not been previously described. A retrospective chart review was performed with hospitalized inpatients from 1 September 2008 to 31 January 2010 comparing QTc interval data from electrocardiogram (ECG) assessment at baseline and after the initiation of combination therapy. Ninety-four patients were eligible for inclusion. The majority, 88 patients (93.6%), received quinolone therapy with levofloxacin. Fifty-three patients (56.4%) received voriconazole; 40 (42.6%) received fluconazole. The overall mean QTc change from baseline was 6.1 (95% confidence interval [CI], 0.2 to 11.9) ms. Twenty-one (22.3%) of the studied patients had clinically significant changes in the QTc while receiving combination fluoroquinolone-azole therapy. Statistically significant risk factors for clinically significant changes in QTc were hypokalemia (P = 0.03) and a left-ventricular ejection fraction of <55% (P = 0.02). Low magnesium (P = 0.11), exposure to 2 or more drugs with the potential to prolong the QTc interval (P = 0.17), and female sex (P = 0.21) trended toward significance. Combination therapy with fluoroquinolone and azole antifungals is associated with increased QTc from baseline in hospitalized patients with hematologic malignancies. One in five patients had a clinically significant change in the QTc, warranting close monitoring and risk factor modification to prevent the possibility of further QTc prolongation and risk of TdP. PMID:23229485

  5. Cross-resistance to fluconazole induced by exposure to the agricultural azole tetraconazole: an environmental resistance school?

    PubMed

    Rocha, Marcos Fábio Gadelha; Alencar, L P; Paiva, M A N; Melo, Luciana Magalhães; Bandeira, Silviane Praciano; Ponte, Y B; Sales, Jamille Alencar; Guedes, G M M; Castelo-Branco, D S C M; Bandeira, T J P G; Cordeiro, R A; Pereira-Neto, W A; Brandine, G S; Moreira, José Luciano Bezerra; Sidrim, José Júlio Costa; Brilhante, Raimunda Sâmia Nogueira

    2016-05-01

    This study aimed to investigate the influence of tetraconazole and malathion, both used in agricultural activities, on resistance to fluconazole, itraconazole and voriconazole in Candida parapsilosis ATCC 22019. The susceptibility to tetraconazole, malathion, fluconazole, itraconazole and voriconazole, through broth microdilution. Then, 12 independent replicates, were separated and exposed to four treatment groups, each one containing three replicates: G1: tetraconazole; G2: malathion; G3: fluconazole (positive control); G4: negative control. Replicates from G1, G2 and G3, were exposed to weekly increasing concentrations of tetraconazole, malathion and fluconazole, respectively, ranging from MIC/2 to 32 × MIC, throughout 7 weeks. The exposure to tetraconazole, but not malathion, decreased susceptibility to clinical azoles, especially fluconazole. The tetraconazole-induced fluconazole resistance is partially mediated by the increased activity of ATP-dependent efflux pumps, considering the increase in antifungal susceptibility after the addition of the efflux pump inhibitor, promethazine, and the increase in rhodamine 6G efflux and CDR gene expression in the G1 replicates. Moreover, MDR expression was only detected in G1 and G3 replicates, suggesting that MDR pumps are also involved in tetraconazole-induced fluconazole resistance. It is noteworthy that tetraconazole and fluconazole-treated replicates behaved similarly, therefore, resistance to azoles of clinical use may be a consequence of using azoles in farming activities. PMID:26864989

  6. Synthesis, bioactivity and structure-activity relationships of new 2-aryl-8-OR-3,4-dihydroisoquinolin-2-iums salts as potential antifungal agents.

    PubMed

    Zhu, Li-Fei; Hou, Zhe; Zhou, Kun; Tong, Zong-Bo; Kuang, Qian; Geng, Hui-Ling; Zhou, Le

    2016-05-15

    As our continuing research on antifungal dihydroisoquinolin-2-ium salts, forty 2-aryl-8-OR-3,4-dihydroisoquinolin-2-ium bromides were synthesized and characterized by spectroscopic analysis. By using the mycelium growth rate method, the compounds were evaluated for antifungal activity against three plant pathogenic fungi and structure-activity relationships (SAR) were derived. The vast majority of the compounds displayed the medium to high activity with inhibition rates of 50-100% at 150μM. About half of the compounds were more active than their natural model compounds sanguinarine and chelerythrine for all the fungi, and part or most of them were more active than positive drugs thiabendazole and azoxystrobin. SAR analysis showed that both substitution patterns of the C-ring and the type of 8-OR group significantly influenced the activity. Thus, a series of new title compounds with excellent antifungal potency emerged. PMID:27072907

  7. Lysosome and HER3 (ErbB3) Selective Anticancer Agent Kahalalide F: Semisynthetic Modifications and Antifungal Lead-Exploration Studies

    PubMed Central

    Shilabin, Abbas Gholipour; Kasanah, Noer; Wedge, David E.; Hamann, Mark T.

    2016-01-01

    Kahalalide F (1) shows remarkable antitumor activity against different carcinomas and has recently completed phase I clinical trials and is being evaluated in phase II clinical studies. The antifungal activity of this molecule has not been thoroughly investigated. In this report, we focused on acetylation and oxidation of the secondary alcohol of threonine, as well as reductive alkylation of the primary amine of ornithine, and each product was evaluated for improvements in antifungal activity. 1 and analogues do not exhibit antimalarial, antileishmania, or antibacterial activity; however, the antifungal activity against different strains of fungi was particularly significant. This series of compounds was highly active against Fusarium spp., which represents an opportunistic infection in humans and plants. The in vitro cytotoxicity for the new analogues of 1 was evaluated in the NCI 60 cell panel. Analogue 5 exhibited enhanced potency in several human cancer cell lines relative to 1. PMID:17696332

  8. Antifungal prophylaxis during neutropenia and immunodeficiency.

    PubMed Central

    Lortholary, O; Dupont, B

    1997-01-01

    Fungal infections represent a major source of morbidity and mortality in patients with almost all types of immunodeficiencies. These infections may be nosocomial (aspergillosis) or community acquired (cryptococcosis), or both (candidiasis). Endemic mycoses such as histoplasmosis, coccidioidomycosis, and penicilliosis may infect many immunocompromised hosts in some geographic areas and thereby create major public health problems. With the wide availability of oral azoles, antifungal prophylactic strategies have been extensively developed. However, only a few well-designed studies involving strict criteria have been performed, mostly in patients with hematological malignancies or AIDS. In these situations, the best dose and duration of administration of the antifungal drug often remain to be determined. In high-risk neutropenic or bone marrow transplant patients, fluconazole is effective for the prevention of superficial and/or systemic candidal infections but is not always able to prolong overall survival and potentially selects less susceptible or resistant Candida spp. Primary prophylaxis against aspergillosis remains investigative. At present, no standard general recommendation for primary antifungal prophylaxis can be proposed for AIDS patients or transplant recipients. However, for persistently immunocompromised patients who previously experienced a noncandidal systemic fungal infection, prolonged suppressive antifungal therapy is often indicated to prevent a relapse. Better strategies for controlling immune deficiencies should also help to avoid some potentially life-threatening deep mycoses. When prescribing antifungal prophylaxis, physicians should be aware of the potential emergence of resistant strains, drug-drug interactions, and the cost. Well-designed, randomized, multicenter clinical trials in high-risk immunocompromised hosts are urgently needed to better define how to prevent severe invasive mycoses. PMID:9227863

  9. Mechanisms of azole resistance in Candida albicans clinical isolates from Shanghai, China.

    PubMed

    Liu, Jin-Yan; Shi, Ce; Wang, Ying; Li, Wen-Jing; Zhao, Yue; Xiang, Ming-Jie

    2015-04-01

    This study was undertaken to characterize the mechanism(s) of azole resistance in clinical isolates of Candida albicans collected in Shanghai, China, focusing on the role of efflux pumps, target enzymes of fluconazole (Erg11), respiratory status and the ergosterol biosynthetic pathway. Clinical isolates of C. albicans (n = 30) were collected from 30 different non-HIV-infected patients in four hospitals in Shanghai. All 30 C. albicans isolates were susceptible to amphotericin B and 5-fluorocytosine. Twelve C. albicans isolates showed resistance to at least one type of triazole antifungal. Flow cytometry analysis of rhodamine 6G efflux showed that azole-resistant isolates had greater efflux pump activity, which was consistent with elevated levels of CDR1 and CDR2 genes that code for ABC efflux pumps. However, we did not observe increased expression of ERG11 and MDR1 or respiratory deficiency. Several mutations of ERG11 and TAC1 genes were detected. The F964Y mutation in the TAC1 gene was identified for the first time. Two main sterols, ergosterol and lanosterol, were identified by GC-MS chromatogram, and no missense mutations were found in ERG3. Furthermore, seven amino acid substitutions in ERG11, A114S, Y132H, Y132F, K143Q, K143R, Y257H and G448E were found, by Type II spectral quantitative analysis, to contribute to low affinity binding between Erg11 and fluconazole. PMID:25748216

  10. Azide-enolate 1,3-dipolar cycloaddition in the synthesis of novel triazole-based miconazole analogues as promising antifungal agents.

    PubMed

    González-Calderón, Davir; Mejía-Dionicio, María G; Morales-Reza, Marco A; Ramírez-Villalva, Alejandra; Morales-Rodríguez, Macario; Jauregui-Rodríguez, Bertha; Díaz-Torres, Eduardo; González-Romero, Carlos; Fuentes-Benítes, Aydeé

    2016-04-13

    Seven miconazole analogs involving 1,4,5-tri and 1,5-disubstituted triazole moieties were synthesized by azide-enolate 1,3-dipolar cycloaddition. The antifungal activity of these compounds was evaluated in vitro against four filamentous fungi, including Aspergillus fumigatus, Trichosporon cutaneum, Rhizopus oryzae, and Mucor hiemalis as well as three species of Candida spp. as yeast specimens. These pre-clinical studies suggest that compounds 4b, 4d and 7b can be considered as drug candidates for future complementary biological studies due to their good/excellent antifungal activities. PMID:26890112

  11. Alternative approaches to antifungal therapies

    PubMed Central

    Mehra, T; Köberle, M; Braunsdorf, C; Mailänder-Sanchez, D; Borelli, C; Schaller, M

    2012-01-01

    The expansive use of immunosuppressive medications in fields such as transplantational medicine and oncology, the higher frequency of invasive procedures in an aging population and the HIV/AIDS pandemic have increased the frequency of systemic fungal infections. At the same time, increased resistance of pathogenic fungi to classical antifungal agents has led to sustained research efforts targeting alternative antifungal strategies. In this review, we focus on two promising approaches: cationic peptides and the targeting of fungal virulence factors. Cationic peptides are small, predominantly positively charged protein fragments which exert direct and indirect antifungal activities, one mechanism of action being the permeabilization of the fungal membrane. They include lysozyme, defensins, and cathelicidins, as well as novel synthetic peptides. Amongst fungal virulence factors, the targeting of candidal secreted aspartic proteinases seems to be a particularly promising approach. PMID:23078400

  12. Bisbibenzyls, a New Type of Antifungal Agent, Inhibit Morphogenesis Switch and Biofilm Formation through Upregulation of DPP3 in Candida albicans

    PubMed Central

    Zhang, Li; Chang, Wenqiang; Sun, Bin; Groh, Matthias; Speicher, Andreas; Lou, Hongxiang

    2011-01-01

    The yeast-to-hypha transition plays a crucial role in the pathogenesis of C. albicans. Farnesol, a quorum sensing molecule (QSM) secreted by the fungal itself, could prevent the formation of hyphae and subsequently lead to the defect of biofilm formation. The DPP3, encoding phosphatase, is a key gene in regulating farnesol synthesis. In this study, we screened 24 bisbibenzyls and 2 bibenzyls that were isolated from bryophytes or chemically synthesized by using CLSI method for antifungal effect. Seven bisbibenzyls were found to have antifungal effects with IC80 less than 32 µg/ml, and among them, plagiochin F, isoriccardin C and BS-34 were found to inhibit the hyphae and biofilm formation of C. albicans in a dose-dependent manner. To uncover the underlying relationship between morphogenesis switch and QSM formation, we measured the farnesol production by HPLC-MS and quantified Dpp3 expression by detecting the fluorescent intensity of green fluorescent protein tagged strain using Confocal Laser Scanning microscopy and Multifunction Microplate Reader. The DPP3 transcripts were determined by real-time PCR. The data indicated that the bisbibenzyls exerted antifungal effects through stimulating the synthesis of farnesol via upregulation of Dpp3, suggesting a potential antifungal application of bisbibenzyls. In addition, our assay provides a novel, visual and convenient method to measure active compounds against morphogenesis switch. PMID:22174935

  13. The Lysosome and HER3 (ErbB3) Selective Anticancer Agent Kahalalide F: Semisynthetic Modifications and Antifungal Lead-Exploration Studies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Kahalalide F shows remarkable anti-tumor activity against different carcinomas and has recently completed phase I clinical trials and is being evaluated in phase II clinical studies. The antifungal activity of this molecule has not been thoroughly investigated. In this report, we focused on acetylat...

  14. Human and ecological risk assessment of a crop protection chemical: a case study with the azole fungicide epoxiconazole.

    PubMed

    Chambers, Janice E; Greim, Helmut; Kendall, Ronald J; Segner, Helmut; Sharpe, Richard M; Van Der Kraak, Glen

    2014-02-01

    Conventional risk assessments for crop protection chemicals compare the potential for causing toxicity (hazard identification) to anticipated exposure. New regulatory approaches have been proposed that would exclude exposure assessment and just focus on hazard identification based on endocrine disruption. This review comprises a critical analysis of hazard, focusing on the relative sensitivity of endocrine and non-endocrine endpoints, using a class of crop protection chemicals, the azole fungicides. These were selected because they are widely used on important crops (e.g. grains) and thereby can contact target and non-target plants and enter the food chain of humans and wildlife. Inhibition of lanosterol 14α-demethylase (CYP51) mediates the antifungal effect. Inhibition of other CYPs, such as aromatase (CYP19), can lead to numerous toxicological effects, which are also evident from high dose human exposures to therapeutic azoles. Because of its widespread use and substantial database, epoxiconazole was selected as a representative azole fungicide. Our critical analysis concluded that anticipated human exposure to epoxiconazole would yield a margin of safety of at least three orders of magnitude for reproductive effects observed in laboratory rodent studies that are postulated to be endocrine-driven (i.e. fetal resorptions). The most sensitive ecological species is the aquatic plant Lemna (duckweed), for which the margin of safety is less protective than for human health. For humans and wildlife, endocrine disruption is not the most sensitive endpoint. It is concluded that conventional risk assessment, considering anticipated exposure levels, will be protective of both human and ecological health. Although the toxic mechanisms of other azole compounds may be similar, large differences in potency will require a case-by-case risk assessment. PMID:24274332

  15. Comparative Lipidomics in Clinical Isolates of Candida albicans Reveal Crosstalk between Mitochondria, Cell Wall Integrity and Azole Resistance

    PubMed Central

    Singh, Ashutosh; Yadav, Vipin; Prasad, Rajendra

    2012-01-01

    Prolonged usage of antifungal azoles which target enzymes involved in lipid biosynthesis invariably leads to the development of multi-drug resistance (MDR) in Candida albicans. We had earlier shown that membrane lipids and their fluidity are closely linked to the MDR phenomenon. In one of our recent studies involving comparative lipidomics between azole susceptible (AS) and azole resistant (AR) matched pair clinical isolates of C. albicans, we could not see consistent differences in the lipid profiles of AS and AR strains because they came from different patients and so in this study, we have used genetically related variant recovered from the same patient collected over a period of 2-years. During this time, the levels of fluconazole (FLC) resistance of the strain increased by over 200-fold. By comparing the lipid profiles of select isolates, we were able to observe gradual and statistically significant changes in several lipid classes, particularly in plasma membrane microdomain specific lipids such as mannosylinositolphosphorylceramides and ergosterol, and in a mitochondrial specific phosphoglyceride, phosphatidyl glycerol. Superimposed with these quantitative and qualitative changes in the lipid profiles, were simultaneous changes at the molecular lipid species levels which again coincided with the development of resistance to FLC. Reverse transcriptase-PCR of the key genes of the lipid metabolism validated lipidomic picture. Taken together, this study illustrates how the gradual corrective changes in Candida lipidome correspond to the development of FLC tolerance. Our study also shows a first instance of the mitochondrial membrane dysfunction and defective cell wall (CW) in clinical AR isolates of C. albicans, and provides evidence of a cross-talk between mitochondrial lipid homeostasis, CW integrity and azole tolerance. PMID:22761908

  16. Natural and synthetic peptides with antifungal activity.

    PubMed

    Ciociola, Tecla; Giovati, Laura; Conti, Stefania; Magliani, Walter; Santinoli, Claudia; Polonelli, Luciano

    2016-08-01

    In recent years, the increase of invasive fungal infections and the emergence of antifungal resistance stressed the need for new antifungal drugs. Peptides have shown to be good candidates for the development of alternative antimicrobial agents through high-throughput screening, and subsequent optimization according to a rational approach. This review presents a brief overview on antifungal natural peptides of different sources (animals, plants, micro-organisms), peptide fragments derived by proteolytic cleavage of precursor physiological proteins (cryptides), synthetic unnatural peptides and peptide derivatives. Antifungal peptides are schematically reported based on their structure, antifungal spectrum and reported effects. Natural or synthetic peptides and their modified derivatives may represent the basis for new compounds active against fungal infections. PMID:27502155

  17. Antifungal Activity of C-27 Steroidal Saponins

    PubMed Central

    Yang, Chong-Ren; Zhang, Ying; Jacob, Melissa R.; Khan, Shabana I.; Zhang, Ying-Jun; Li, Xing-Cong

    2006-01-01

    As part of our search for new antifungal agents from natural resources, 22 C-27 steroidal saponins and 6 steroidal sapogenins isolated from several monocotyledonous plants were tested for their antifungal activity against the opportunistic pathogens Candida albicans, Candida glabrata, Candida krusei, Cryptococcus neoformans, and Aspergillus fumigatus. The results showed that the antifungal activity of the steroidal saponins was associated with their aglycone moieties and the number and structure of monosaccharide units in their sugar chains. Within the 10 active saponins, four tigogenin saponins (compounds 1 to 4) with a sugar moiety of four or five monosaccharide units exhibited significant activity against C. neoformans and A. fumigatus, comparable to the positive control amphotericin B. The antifungal potency of these compounds was not associated with cytotoxicity to mammalian cells. This suggests that the C-27 steroidal saponins may be considered potential antifungal leads for further preclinical study. PMID:16641439

  18. Acquired Multidrug Antifungal Resistance in Candida lusitaniae during Therapy

    PubMed Central

    Asner, Sandra A.; Giulieri, Stefano; Diezi, Manuel; Marchetti, Oscar

    2015-01-01

    Candida lusitaniae is usually susceptible to echinocandins. Beta-1,3-glucan synthase encoded by FKS genes is the target of echinocandins. A few missense mutations in the C. lusitaniae FKS1 hot spot 1 (HS1) have been reported. We report here the rapid emergence of antifungal resistance in C. lusitaniae isolated during therapy with amphotericin B (AMB), caspofungin (CAS), and azoles for treatment of persistent candidemia in an immunocompromised child with severe enterocolitis and visceral adenoviral disease. As documented from restriction fragment length polymorphism (RFLP) and random amplified polymorphic DNA (RAPD) analysis, the five C. lusitaniae isolates examined were related to each other. From antifungal susceptibility and molecular analyses, 5 different profiles (P) were obtained. These profiles included the following: profile 1 (P1) (CAS MIC [μg/ml], 0.5; fluconazole [FLC] MIC, 0.25), determined while the patient was being treated with liposomal AMB for 3 months; P2 (FLC MIC [μg/ml], 0.25; CAS MIC, 4), while the patient was being treated with CAS for 2 weeks; P3 (CAS MIC [μg/ml], 0.5; FLC MIC, 32), while the patient was being treated with azoles and CAS initially followed by azoles alone for a week; P4 (CAS MIC [μg/ml], 8; FLC MIC, 8), while the patient was being treated with both drugs for 3 weeks; and P5 (AMB MIC [μg/ml], 0.125; CAS MIC, 8), while the patient was being treated with AMB and FLC for 2 weeks. CAS resistance was associated with resistance not only to micafungin and anidulafungin but also to AMB. Analysis of CAS resistance revealed 3 novel FKS1 mutations in CAS-resistant isolates (S638Y in P2; S631Y in P4; S638P in P5). While S638Y and -P are within HS1, S631Y is in close proximity to this domain but was confirmed to confer candin resistance using a site-directed mutagenesis approach. FLC resistance could be linked with overexpression of major facilitator gene 7 (MFS7) in C. lusitaniae P2 and P4 and was associated with resistance to 5

  19. Epidemiology and antifungal susceptibilities of yeasts causing vulvovaginitis in a teaching hospital.

    PubMed

    Gamarra, Soledad; Morano, Susana; Dudiuk, Catiana; Mancilla, Estefanía; Nardin, María Elena; de Los Angeles Méndez, Emilce; Garcia-Effron, Guillermo

    2014-10-01

    Vulvovaginal candidiasis is one of the most common mycosis. However, the information about antifungal susceptibilities of the yeasts causing this infection is scant. We studied 121 yeasts isolated from 118 patients with vulvovaginal candidiasis. The isolates were identified by phenotypic and molecular methods, including four phenotypic methods described to differentiate Candida albicans from C. dubliniensis. Antifungal susceptibility testing was performed according to CLSI documents M27A3 and M27S4 using the drugs available as treatment option in the hospital. Diabetes, any antibacterial and amoxicillin treatment were statistically linked with vulvovaginal candidiasis, while oral contraceptives were not considered a risk factor. Previous azole-based over-the-counter antifungal treatment was statistically associated with non-C.albicans yeasts infections. The most common isolated yeast species was C. albicans (85.2 %) followed by C. glabrata (5 %), Saccharomyces cerevisiae (3.3 %), and C. dubliniensis (2.5 %). Fluconazole- and itraconazole-reduced susceptibility was observed in ten and in only one C. albicans strains, respectively. All the C. glabrata isolates showed low fluconazole MICs. Clotrimazole showed excellent potency against all but seven isolates (three C. glabrata, two S. cerevisiae, one C. albicans and one Picchia anomala). Any of the strains showed nystatin reduced susceptibility. On the other hand, terbinafine was the less potent drug. Antifungal resistance is still a rare phenomenon supporting the use of azole antifungals as empirical treatment of vulvovaginal candidiasis. PMID:25005365

  20. Exploring the molecular basis of antifungal synergies using genome-wide approaches

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This is a review article summarizing genomic profiling strategies for determining the mechanism of action of antifungal synergies, and highlighting the potential applications of these technologies. Given the limitations of currently available antifungal agents and the development of drug resistance...

  1. HPLC-DAD for the determination of three different classes of antifungals: method characterization, statistical approach, and application to a permeation study.

    PubMed

    Miron, Diogo; Lange, Alini; Zimmer, Aline R; Mayorga, Paulo; Schapoval, Elfrides E S

    2014-12-01

    This study describes and characterizes methods for high-performance liquid chromatography diode array detection (HPLC-DAD) analysis of formulations containing molecules with antifungal activity of three different classes: terbinafine and butenafine (allylamines), miconazole and fluconazole (azoles), and geraniol, neral and geranial (monoterpenes). All methods used the same chromatographic column (RP18 ), enabling the analysis to be performed in a single batch. The specificity was extensively discussed through the establishment of purity peak methods. The analytical parameters (linearity, precision and accuracy) were calculated and discussed in detail using specific statistical approaches. All substances showed satisfactory results for chromatographic and analytical parameters. Limits of 1.3% to mean repeatability and 2.0% for intermediate precision are suggested as acceptance criteria in validation of methods by HPLC-DAD, in situations where there is no extensive pretreatment of the samples. The methods proved to be robust and significant factors were discussed regarding their influence on chromatographic parameters (retention time, resolution, tailing factor and column efficiency). Finally, the application of the developed methods was demonstrated by the results of a permeation study of the antifungal agents through bovine hoof membranes. PMID:24788676

  2. Novel imidazo[2,1-b]-1,3,4-thiadiazoles as promising antifungal agents against clinical isolate of Cryptococcus neoformans.

    PubMed

    Alwan, Wesam S; Karpoormath, Rajshekhar; Palkar, Mahesh B; Patel, Harun M; Rane, Rajesh A; Shaikh, Mahamadhanif S; Kajee, Afsana; Mlisana, Koleka P

    2015-05-01

    We herein report the synthesis and in vitro antimicrobial evaluation of twenty five novel hybrid derivatives of imidazo [2,1-b]-1,3,4-thiadiazole containing chalcones (5a-o) and Schiff bases (6a-j) against three fungal strains (Candida albicans, Cryptococcus neoformans and Aspergillus niger). Most of the tested compounds displayed substantial anti-fungal activity with MICs ranging between 1.56 and 100 μg/mL. Compounds 5a, 5b and 5n exhibited promising activity against C. neoformans at a MIC 1.56 μg/mL. In addition, compound 5n also demonstrated significant antifungal activity against the clinical isolates of C. neoformans at MIC 3.125 μg/mL. However, moderate activity was observed for these compounds against four bacterial strains (Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa) and Mycobacterium tuberculosis (H37Rv). PMID:25847769

  3. Efficient Production of the Flavoring Agent Zingerone and of both (R)- and (S)-Zingerols via Green Fungal Biocatalysis. Comparative Antifungal Activities between Enantiomers

    PubMed Central

    Svetaz, Laura A.; Di Liberto, Melina G.; Zanardi, María M.; Suárez, Alejandra G.; Zacchino, Susana A.

    2014-01-01

    Zingerone (1) and both chiral forms of zingerol (2) were obtained from dehydrozingerone (3) by biotransformation with filamentous fungi. The bioconversion of 3 with A. fumigatus, G. candidum or R. oryzae allowed the production of 1 as the sole product at 8 h and in 81%–90% at 72 h. In turn, A. flavus, A. niger, C. echinulata, M. circinelloides and P. citrinum produced 1 at 8 h, but at 72 h alcohol 2 was obtained as the major product (74%–99%). Among them, A. niger and M. circinelloides led to the anti-Prelog zingerol (R)-2 in only one step with high conversion rates and ee. Instead, C. echinulata and P. citrinum allowed to obtain (S)-2 in only one step, with high conversion rates and ee. Both chiral forms of 2 were tested for antifungal properties against a panel of clinically important fungi, showing that (R)-, but not (S)-2 possessed antifungal activity. PMID:25470023

  4. Antifungal susceptibility patterns of a global collection of fungal isolates: results of the SENTRY Antifungal Surveillance Program (2013).

    PubMed

    Castanheira, Mariana; Messer, Shawn A; Rhomberg, Paul R; Pfaller, Michael A

    2016-06-01

    Among 1846 fungal clinical isolates from 31 countries, echinocandin resistance in Candida spp. ranged from 0.0% to 2.8% (highest for anidulafungin versus Candida glabrata), and fluconazole resistance was noted among 11.9% and 11.6% of the C. glabrata and Candida tropicalis, respectively. Two isolates of Aspergillus fumigatus displayed elevated MICs for itraconazole and carried cyp51a mutations encoding TR34 L98H. All Cryptococcus neoformans had azole MIC values below epidemiological cutoff values. The increasing resistance among certain species and more frequent reports of breakthrough infections in patients undergoing antifungal therapy highlights the importance of antifungal surveillance to guide therapy for patients with invasive fungal infections. PMID:27061369

  5. Fitness Studies of Azole-Resistant Strains of Aspergillus fumigatus.

    PubMed

    Valsecchi, Isabel; Mellado, Emilia; Beau, Rémi; Raj, Shriya; Latgé, Jean-Paul

    2015-12-01

    Isogenic bar-coded strains of Aspergillus fumigatus carrying the G54W or M220K mutation in Cyp51A were constructed. In vitro, the growth and conidiation capacities of the mutants were similar to those of the parental strain. Competition studies in the absence of azoles showed that there was no adverse fitness cost for the azole-resistant A. fumigatus strains in vitro or in vivo compared to the parental strain. PMID:26416854

  6. Fitness Studies of Azole-Resistant Strains of Aspergillus fumigatus

    PubMed Central

    Valsecchi, Isabel; Mellado, Emilia; Beau, Rémi; Raj, Shriya

    2015-01-01

    Isogenic bar-coded strains of Aspergillus fumigatus carrying the G54W or M220K mutation in Cyp51A were constructed. In vitro, the growth and conidiation capacities of the mutants were similar to those of the parental strain. Competition studies in the absence of azoles showed that there was no adverse fitness cost for the azole-resistant A. fumigatus strains in vitro or in vivo compared to the parental strain. PMID:26416854

  7. Reactivity of azole anions with CO₂ from the DFT perspective.

    PubMed

    Tang, Huarong; Wu, Chao

    2013-06-01

    Azole anions are key components in CO₂ capture materials that include ionic liquids and porous solids. Herein, we use density functional theory (DFT) and a Langmuir-type adsorption model to study azole anion-CO₂ interactions. Linear CO₂ has to be bent by approximately 45° to form an N-C bond within the azole ring. The energy cost of bending renders CO₂ absorption much more difficult compared to SO₂ absorption. For different azole anions, the number of nitrogen atoms in the ring and the natural bond orbital energy of the reacting nitrogen lone pair, both linearly correlate with the calculated reaction enthalpy and are useful handles for new sorbent designs. Unlike for SO₂, the azole parent architecture (unsubstituted) does not allow successive CO₂ absorption under mild conditions (<0.12 MPa and at room temperature). Experimental CO₂ and SO₂ absorption isotherms are reproduced by using the Langmuir model parameterized with the calibrated DFT reaction enthalpies. This study provides insight for designing azole-based CO₂-capture materials. PMID:23640877

  8. The Candida albicans Lanosterol 14-α-Demethylase (ERG11) Gene Promoter Is Maximally Induced after Prolonged Growth with Antifungal Drugs

    PubMed Central

    Song, Jia L.; Beth Harry, Jo; Eastman, Richard T.; Oliver, Brian G.; White, Theodore C.

    2004-01-01

    The azole antifungal drugs that target lanosterol 14-α-demethylase, encoded by the ERG11 gene, are used to treat a variety of infections caused by Candida albicans. Azoles are known to induce expression of ERG11 mRNA. The ERG11 promoter was cloned 5′ of the luciferase-coding region, and the induction of ERG11 expression by azoles was monitored by luciferase assays. Maximal induction of the ERG11 promoter by azoles occurs not during logarithmic growth but after the diauxic shift and requires azoles to be present throughout logarithmic growth. The effects of pH, carbon source, and aerobic or anaerobic growth on induction of the ERG11 promoter by azoles were analyzed. Treatment with terbinafine and fenpropimorph, which target other enzymes in the ergosterol biosynthetic pathway, also resulted in a delayed induction of ERG11 promoter activity. Nascent sterol synthesis was shown to parallel ERG11 promoter activity, and total sterols were reduced coincident with the timing of ERG11 promoter activation. These results as a whole suggest that expression of the ERG11 promoter is regulated in response to sterol depletion. PMID:15047513

  9. The role of new eudesmane-type sesquiterpenoid and known eudesmane derivatives from the red alga Laurencia obtusa as potential antifungal-antitumour agents.

    PubMed

    Alarif, Walied M; Al-Footy, Khalid O; Zubair, Muhammad Sulaiman; Halid Ph, Mohamed; Ghandourah, Mohamed A; Basaif, Salim A; Al-Lihaibi, Sultan S; Ayyad, Seif-Eldin N; Badria, Farid A

    2016-05-01

    A new eudesmane sesquiterpenoid, eudesma-4(15),7-diene-5,11-diol (1) along with the known trinor-sesquiterene, teuhetenone (2), and a seco-eudesmane sesquiterpene, chabrolidione B (3), have been isolated from the Red Sea red alga Laurencia obtusa. The chemical structures were elucidated on the basis of extensive spectroscopic analysis. The antifungal and cytotoxic activities of the isolated metabolites were tested against several fungi, yeast and human mammary carcinoma cell line (MCF-7). Compounds 1 and 3 showed a much better activity [minimum inhibitory concentration (MIC): 2.9 μM] than that of amphotericin B (MIC: 4.6 μM). Interestingly, compound 2, the least active antifungal compound, retained the high anticancer activity against MCF-7 (22 μM) in comparison with cisplatin (59 μM), which was determined by employing lactate dehydrogenase assay. Compounds 1-3 are recorded here for the first time from algal flora. The chemotaxonomic importance of the isolated metabolites was discussed. PMID:26181888

  10. The calcineurin inhibitor cyclosporin A exhibits synergism with antifungals against Candida parapsilosis species complex.

    PubMed

    Cordeiro, Rossana de Aguiar; Macedo, Ramila de Brito; Teixeira, Carlos Eduardo Cordeiro; Marques, Francisca Jakelyne de Farias; Bandeira, Tereza de Jesus Pinheiro Gomes; Moreira, José Luciano Bezerra; Brilhante, Raimunda Sâmia Nogueira; Rocha, Marcos Fábio Gadelha; Sidrim, José Júlio Costa

    2014-07-01

    Candida parapsilosis complex comprises three closely related species, C. parapsilosis sensu stricto, Candida metapsilosis and Candida orthopsilosis. In the last decade, antifungal resistance to azoles and caspofungin among C. parapsilosis sensu lato strains has been considered a matter of concern worldwide. In the present study, we evaluated the synergistic potential of antifungals and the calcineurin inhibitor cyclosporin A (Cys) against planktonic and biofilms of C. parapsilosis complex from clinical sources. Susceptibility assays with amphotericin, fluconazole, voriconazole, caspofungin and Cys were performed by microdilution in accordance with Clinical and Laboratory Standards Institute guidelines. Synergy testing against planktonic cells of C. parapsilosis sensu lato strains was assessed by the chequerboard method. Combinations formed by antifungals with Cys were evaluated against mature biofilms in microtitre plates. No differences in the antifungal susceptibility pattern among species were observed, but C. parapsilosis sensu stricto strains were more susceptible to Cys than C. orthopsilosis and C. metapsilosis. Synergism between antifungals and Cys was observed in C. parapsilosis sensu lato strains. Combinations formed by antifungals and Cys were able to prevent biofilm formation and showed an inhibitory effect against mature biofilms of C. parapsilosis sensu stricto, C. metapsilosis and C. orthopsilosis. These results strengthen the potential of calcineurin inhibition as a promising approach to enhance the efficiency of antifungal drugs. PMID:24722799

  11. In Vitro Susceptibilities of Clinical Yeast Isolates to the New Antifungal Eberconazole Compared with Their Susceptibilities to Clotrimazole and Ketoconazole

    PubMed Central

    Torres-Rodríguez, Josep M.; Mendez, Raúl; López-Jodra, Olga; Morera, Yolanda; Espasa, Mateu; Jimenez, Teresa; Lagunas, Carme

    1999-01-01

    The antifungal activity of eberconazole, a new imidazole derivative, against 124 clinical isolates of Candida comprising eight different species and to 34 isolates of Cryptococcus neoformans was compared to those of clotrimazole and ketoconazole. MICs of eberconazole, determined by the National Committee for Clinical Laboratory Standards standardized microbroth method, were equal to or lower than those of other azoles, especially for Candida krusei and Candida glabrata, which are usually resistant to triazoles. PMID:10223946

  12. [Recent advances in the study of antifungal lead compounds with new chemical scaffolds].

    PubMed

    Shao, Lü-cheng; Sheng, Chun-quan; Zhang, Wan-nian

    2007-11-01

    In recent years, the incidence of infections caused by invasive fungal pathogens has increased dramatically. However, most antifungal agents used in clinic have many drawbacks and cannot meet the demand of the clinical use. Therefore, for the development of new generation of antifungal agents, it is of great significance to find antifungal lead compounds with novel chemical scaffolds and new mode of action. Novel antifungal lead compounds reported in recent years are reviewed. Their chemical structures, antifungal activity and structure-activity relationship are discussed in detail, and current problems and trends in future research are also emphasized. PMID:18300466

  13. Predictors of choice of initial antifungal treatment in intraabdominal candidiasis.

    PubMed

    Lagunes, L; Borgatta, B; Martín-Gomez, M T; Rey-Pérez, A; Antonelli, M; Righi, E; Merelli, M; Brugnaro, P; Dimopoulos, G; Garnacho-Montero, J; Colombo, A L; Luzzati, R; Menichetti, F; Muñoz, P; Nucci, M; Scotton, G; Viscoli, C; Tumbarello, M; Bassetti, M; Rello, J

    2016-08-01

    Intraabdominal candidiasis (IAC) is the second most frequent form of invasive candidiasis, and is associated with high mortality rates. This study aims to identify current practices in initial antifungal treatment (IAT) in a real-world scenario and to define the predictors of the choice of echinocandins or azoles in IAC episodes. Secondary analysis was performed of a multinational retrospective cohort at 13 teaching hospitals in four countries (Italy, Greece, Spain and Brazil), over a 3-year period (2011-2013). IAC was identified in 481 patients, 323 of whom received antifungal therapy (classified as the treatment group). After excluding 13 patients given amphotericin B, the treatment group was further divided into the echinocandin group (209 patients; 64.7%) and the azole group (101 patients; 32.3%). Median APACHE II scores were significantly higher in the echinocandin group (p 0.013), but IAT did not differ significantly with regard to the Candida species involved. Logistic multivariate stepwise regression analysis, adjusted for centre effect, identified septic shock (adjusted OR (aOR) 1.54), APACHE II >15 (aOR 1.16) and presence in surgical ward at diagnosis (aOR 1.16) as the top three independent variables associated with an empirical echinocandin regimen. No differences in 30-day mortality were observed between groups. Echinocandin regimen was the first choice for IAT in patients with IAC. No statistical differences in mortality were observed between regimens, but echinocandins were administered to patients with more severe disease. Some disagreements were identified between current clinical guidelines and prescription of antifungals for IAC at the bedside, so further educational measures are required to optimize therapies. PMID:27432766

  14. Epidemiological changes with potential implication for antifungal prescription recommendations for fungaemia: data from a nationwide fungaemia surveillance programme.

    PubMed

    Arendrup, M C; Dzajic, E; Jensen, R H; Johansen, H K; Kjaeldgaard, P; Knudsen, J D; Kristensen, L; Leitz, C; Lemming, L E; Nielsen, L; Olesen, B; Rosenvinge, F S; Røder, B L; Schønheyder, H C

    2013-08-01

    Significant changes in the management of fungaemia have occurred over the last decade with increased use of fluconazole prophylaxis, of empirical treatment and of echinocandins as first-line agents for documented disease. These changes may impact the epidemiology of fungaemia. We present nationwide data for Denmark from 2010 to 2011. A total of 1081 isolates from 1047 episodes were recorded in 995 patients. The numbers of patients, episodes and recovered isolates increased by 13.1%, 14.5% and 14.1%, respectively, from 2010 to 2011. The incidence rate was significantly higher in 2011 (10.05/100 000) than in 2010 (8.82/100 000), but remained constant in the age groups 0-79 years. The incidence rate was highest at the extremes of age and in males. Candida albicans accounted for 52.1% but declined during 2004-11 (p 0.0155). Candida glabrata accounted for 28% and increased during 2004-2011 (p <0.0001). Candida krusei, Candida tropicalis and Candida parapsilosis remained rare (3.3-4.2%). The species distribution changed with increasing age (fewer C. parapsilosis and more C. glabrata) and by study centre. Overall, the susceptibility rates were: amphotericin B 97.3%, anidulafungin 93.8%, fluconazole 66.7%, itraconazole 69.6%, posaconazole 64.2% and voriconazole 85.0%. Acquired echinocandin resistance was molecularly confirmed in three isolates. The use of systemic antifungals doubled over the last decade (2002-2011) (from 717 000 to 1 450 000 defined daily doses/year) of which the vast majority (96.9%) were azoles. The incidence of fungaemia continues to increase in Denmark and is associated with a decreasing proportion being susceptible to fluconazole. Changes in demography, higher incidence in the elderly and higher antifungal consumption can at least in part explain the changes. PMID:23607326

  15. Comparison of echinocandin antifungals

    PubMed Central

    Eschenauer, Gregory; DePestel, Daryl D; Carver, Peggy L

    2007-01-01

    The incidence of invasive fungal infections, especially those due to Aspergillus spp. and Candida spp., continues to increase. Despite advances in medical practice, the associated mortality from these infections continues to be substantial. The echinocandin antifungals provide clinicians with another treatment option for serious fungal infections. These agents possess a completely novel mechanism of action, are relatively well-tolerated, and have a low potential for serious drug–drug interactions. At the present time, the echinocandins are an option for the treatment of infections due Candida spp (such as esophageal candidiasis, invasive candidiasis, and candidemia). In addition, caspofungin is a viable option for the treatment of refractory aspergillosis. Although micafungin is not Food and Drug Administration-approved for this indication, recent data suggests that it may also be effective. Finally, caspofungin- or micafungin-containing combination therapy should be a consideration for the treatment of severe infections due to Aspergillus spp. Although the echinocandins share many common properties, data regarding their differences are emerging at a rapid pace. Anidulafungin exhibits a unique pharmacokinetic profile, and limited cases have shown a potential far activity in isolates with increased minimum inhibitory concentrations to caspofungin and micafungin. Caspofungin appears to have a slightly higher incidence of side effects and potential for drug–drug interactions. This, combined with some evidence of decreasing susceptibility among some strains of Candida, may lessen its future utility. However, one must take these findings in the context of substantially more data and use with caspofungin compared with the other agents. Micafungin appears to be very similar to caspofungin, with very few obvious differences between the two agents. PMID:18360617

  16. Defensins: antifungal lessons from eukaryotes

    PubMed Central

    Silva, Patrícia M.; Gonçalves, Sónia; Santos, Nuno C.

    2014-01-01

    Over the last years, antimicrobial peptides (AMPs) have been the focus of intense research toward the finding of a viable alternative to current antifungal drugs. Defensins are one of the major families of AMPs and the most represented among all eukaryotic groups, providing an important first line of host defense against pathogenic microorganisms. Several of these cysteine-stabilized peptides present a relevant effect against fungi. Defensins are the AMPs with the broader distribution across all eukaryotic kingdoms, namely, Fungi, Plantae, and Animalia, and were recently shown to have an ancestor in a bacterial organism. As a part of the host defense, defensins act as an important vehicle of information between innate and adaptive immune system and have a role in immunomodulation. This multidimensionality represents a powerful host shield, hard for microorganisms to overcome using single approach resistance strategies. Pathogenic fungi resistance to conventional antimycotic drugs is becoming a major problem. Defensins, as other AMPs, have shown to be an effective alternative to the current antimycotic therapies, demonstrating potential as novel therapeutic agents or drug leads. In this review, we summarize the current knowledge on some eukaryotic defensins with antifungal action. An overview of the main targets in the fungal cell and the mechanism of action of these AMPs (namely, the selectivity for some fungal membrane components) are presented. Additionally, recent works on antifungal defensins structure, activity, and cytotoxicity are also reviewed. PMID:24688483

  17. New therapeutic strategies for invasive aspergillosis in the era of azole resistance: how should the prevalence of azole resistance be defined?

    PubMed

    Alanio, Alexandre; Denis, Blandine; Hamane, Samia; Raffoux, Emmanuel; Peffault de la Tour, Régis; Touratier, Sophie; Bergeron, Anne; Bretagne, Stéphane

    2016-08-01

    Given reports showing a high prevalence of azole resistance in Aspergillus fumigatus, alternatives to azole therapy are discussed when a threshold of 10% of azole-resistant environmental isolates is reached. This raises the issue of calculation of this threshold, either on the prevalence of azole-resistant isolates as a whole or on the prevalence of azole-resistant cases in populations at risk of invasive aspergillosis (IA). For isolate evaluation, there are high disparities in routine microbiological procedures for the isolation of A. fumigatus and azole resistance detection. There are also huge differences between the microbiological work-up for diagnosing IA. Some centres rely on galactomannan detection alone without actively trying to culture appropriate samples, which affects reliability of the figures on the prevalence of resistance and thus the threshold of resistance. Moreover, reports from the laboratory could mix up figures from completely different patient populations: frequent azole-resistant isolates from pneumology patients and rare azole-resistant isolates from haematology patients. Therefore, to sum isolates from different specimens and different wards can lead to erroneous calculations for the restricted populations at risk of developing IA. In conclusion, assessing the incidence of azole resistance in A. fumigatus should be based on harmonized consensual microbiological methods and reports should be restricted to IA episodes in identified populations at risk of IA when the issue is to define an operational threshold for modifying recommendations. PMID:27494830

  18. Systematic Phenotyping of a Large-Scale Candida glabrata Deletion Collection Reveals Novel Antifungal Tolerance Genes

    PubMed Central

    Hiller, Ekkehard; Istel, Fabian; Tscherner, Michael; Brunke, Sascha; Ames, Lauren; Firon, Arnaud; Green, Brian; Cabral, Vitor; Marcet-Houben, Marina; Jacobsen, Ilse D.; Quintin, Jessica; Seider, Katja; Frohner, Ingrid; Glaser, Walter; Jungwirth, Helmut; Bachellier-Bassi, Sophie; Chauvel, Murielle; Zeidler, Ute; Ferrandon, Dominique; Gabaldón, Toni; Hube, Bernhard; d'Enfert, Christophe; Rupp, Steffen; Cormack, Brendan; Haynes, Ken; Kuchler, Karl

    2014-01-01

    The opportunistic fungal pathogen Candida glabrata is a frequent cause of candidiasis, causing infections ranging from superficial to life-threatening disseminated disease. The inherent tolerance of C. glabrata to azole drugs makes this pathogen a serious clinical threat. To identify novel genes implicated in antifungal drug tolerance, we have constructed a large-scale C. glabrata deletion library consisting of 619 unique, individually bar-coded mutant strains, each lacking one specific gene, all together representing almost 12% of the genome. Functional analysis of this library in a series of phenotypic and fitness assays identified numerous genes required for growth of C. glabrata under normal or specific stress conditions, as well as a number of novel genes involved in tolerance to clinically important antifungal drugs such as azoles and echinocandins. We identified 38 deletion strains displaying strongly increased susceptibility to caspofungin, 28 of which encoding proteins that have not previously been linked to echinocandin tolerance. Our results demonstrate the potential of the C. glabrata mutant collection as a valuable resource in functional genomics studies of this important fungal pathogen of humans, and to facilitate the identification of putative novel antifungal drug target and virulence genes. PMID:24945925

  19. In vitro Antifungal Activity of Luliconazole against Trichophyton spp.

    PubMed

    Maeda, Jun; Nanjoh, Yasuko; Koga, Hiroyasu; Toga, Tetsuo; Makimura, Koichi; Tsuboi, Ryoji

    2016-01-01

    The minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) of luliconazole against Trichophyton rubrum (14 strains) and Trichophyton mentagrophytes (14 strains), which are the most common cause of tinea, were compared with those of 6 topical antifungal drugs of lanoconazole, bifonazole, efinaconazole, liranaftate, naftifine and terbinafine. Luliconazole showed the most potent antifungal activity (MIC90 =0.00098 μg/ml and MFC90 =0.0078 μg/ml) among the compounds tested against the two species. Efinaconazole and bifonazole, the drug of azole-class, showed a large MFC/MIC ratio. On the other hand, these ratios of luliconazole and lanoconazole were as small as those of liranaftate, naftifine and terbinafine which are thought to possess fungicidal mechanism. These results suggest that luliconazole possesses fungicidal activity against both species of Trichophyton. In this study, we found that luliconazole had the most potent antifungal activity among the major topical antimycotics used in Japan and the US. Luliconazole would be the best-in-class drug for dermatophytosis in clinics. PMID:26936346

  20. Antifungal effect and action mechanism of antimicrobial peptide polybia-CP.

    PubMed

    Wang, Kairong; Jia, Fengjing; Dang, Wen; Zhao, Yanyan; Zhu, Ranran; Sun, Mengyang; Qiu, Shuai; An, Xiaoping; Ma, Zelin; Zhu, Yuanyuan; Yan, Jiexi; Kong, Ziqing; Yan, Wenjin; Wang, Rui

    2016-01-01

    The incidence of life-threatening invasive fungal infections increased significantly in recent years. However, the antifungal therapeutic options are very limited. Antimicrobial peptides are a class of potential lead chemical for the development of novel antifungal agents. Antimicrobial peptide polybia-CP was purified from the venom of the social wasp Polybia paulista. In this study, we synthesized polybia-CP and determined its antifungal effects against a series of Candidian species. Our results showed that polybia-CP has potent antifungal activity and fungicidal activity against the tested fungal cells with a proposed membrane-active action mode. In addition, polybia-CP could induce the increase of cellular reactive oxygen species production, which would attribute to its antifungal activity. In conclusion, the present study suggests that polybia-CP has potential as an antifungal agent or may offer a new strategy for antifungal therapeutic option. PMID:26680221

  1. Stereospecific Metabolism of Itraconazole by CYP3A4: Dioxolane Ring Scission of Azole Antifungals

    PubMed Central

    Peng, Chi-Chi; Shi, Wei; Lutz, Justin D.; Kunze, Kent L.; Liu, Jun O.; Nelson, Wendel L.

    2012-01-01

    Itraconazole (ITZ) is a mixture of four cis-stereoisomers that inhibit CYP3A4 potently and coordinate CYP3A4 heme via the triazole nitrogen. However, (2R,4S,2′R)-ITZ and (2R,4S,2′S)-ITZ also undergo stereoselective sequential metabolism by CYP3A4 at a site distant from the triazole ring to 3′-OH-ITZ, keto-ITZ, and N-desalkyl-ITZ. This stereoselective metabolism demonstrates specific interactions of ITZ within the CYP3A4 active site. To further investigate this process, the binding and metabolism of the four trans-ITZ stereoisomers by CYP3A4 were characterized. All four trans-ITZ stereoisomers were tight binding inhibitors of CYP3A4-mediated midazolam hydroxylation (IC50 16–26 nM), and each gave a type II spectrum upon binding to CYP3A4. However, instead of formation of 3′-OH-ITZ, they were oxidized at the dioxolane ring, leading to ring scission and formation of two new metabolites of ITZ. These two metabolites were also formed from the four cis-ITZ stereoisomers, although not as efficiently. The catalytic rates of dioxolane ring scission were similar to the dissociation rates of ITZ stereoisomers from CYP3A4, suggesting that the heme iron is reduced while the triazole moiety coordinates to it and no dissociation of ITZ is necessary before catalysis. The triazole containing metabolite [1-(2,4-dichlorophenyl)-2-(1H-1,2,4-triazol-1-yl)ethanone] also inhibited CYP3A4 (IC50 >15 μM) and showed type II binding with CYP3A4. The dioxolane ring scission appears to be clinically relevant because this metabolite was detected in urine samples from subjects that had been administered the mixture of cis-ITZ isomers. These data suggest that the dioxolane ring scission is a metabolic pathway for drugs that contain this moiety. PMID:22106171

  2. Modelling inhibition of avian aromatase by azole pesticides

    PubMed Central

    Saxena, A.K.; Devillers, J.; Bhunia, S.S.; Bro, E.

    2015-01-01

    The potential effects of pesticides and their metabolites on the endocrine system are of major concern to wildlife and human health. In this context, the azole pesticides have earned special attention due to their cytochrome P450 aromatase inhibition potential. Cytochrome P450 aromatase (CYP19) catalyses the conversion of androstenedione and testosterone into oestrone and oestradiol, respectively. Thus, aromatase modulates the oestrogenic balance essential not only for females, but also for male physiology, including gonadal function. Its inhibition affects reproductive organs, fertility and sexual behaviour in humans and wildlife species. Several studies have shown that azole pesticides are able to inhibit human and fish aromatases but the information on birds is lacking. Consequently, it appeared to be of interest to estimate the aromatase inhibition of azoles in three different avian species, namely Gallus gallus, Coturnix coturnix japonica and Taeniopygia guttata. In the absence of the crystal structure of the aromatase enzyme in these bird species, homology models for the individual avian species were constructed using the crystal structure of human aromatase (hAr) (pdb: 3EQM) that showed high sequence similarity for G. gallus (82.0%), T. guttata (81.9%) and C. japonica (81.2%). A homology model with Oncorhynchus mykiss (81.9%) was also designed for comparison purpose. The homology-modelled aromatase for each avian and fish species and crystal structure of human aromatase were selected for docking 46 structurally diverse azoles and related compounds. We showed that the docking behaviour of the chemicals on the different aromatases was broadly the same. We also demonstrated that there was an acceptable level of correlation between the binding score values and the available aromatase inhibition data. This means that the homology models derived on bird and fish species can be used to approximate the potential inhibitory effects of azoles on their aromatase. PMID

  3. Pharmacokinetics and Pharmacodynamics of Antifungals in Children: Clinical Implications

    PubMed Central

    Autmizguine, Julie; Guptill, Jeffrey T.; Cohen-Wolkowiez, Michael; Benjamin, Daniel K.; Capparelli, Edmund V.

    2014-01-01

    Invasive fungal disease (IFD) remains life-threatening in premature infants and immunocompromised children despite the recent development of new antifungal agents. Optimal dosing of antifungals is one of the few factors clinicians can control to improve outcomes of IFD. However, dosing in children cannot be extrapolated from adult data because IFD pathophysiology, immune response, and drug disposition differ from adults. We critically examined the literature on pharmacokinetics (PK) and pharmacodynamics (PD) of antifungal agents and highlight recent developments in treating pediatric IFD. To match adult exposure in pediatric patients, dosing adjustment is necessary for almost all antifungals. In young infants, the maturation of renal and metabolic functions occurs rapidly and can significantly influence drug exposure. Fluconazole clearance doubles from birth to 28 days of life and, beyond the neonatal period, agents like fluconazole, voriconazole, and micafungin require higher dosing than in adults due to faster clearance in children. As a result, dosing recommendations are specific to bracketed ranges of age. Pharmacodynamics principles of antifungals mostly rely on in vitro and in vivo models but very few pharmacodynamics studies specifically address IFD in children. Exposure-response relationship may differ in younger children compared with adults, especially in infants with invasive candidiasis who are at higher risk of disseminated disease and meningoencephalitis, and by extension severe neurodevelopmental impairment. Micafungin is the only antifungal agent for which a specific target of exposure was proposed based on a neonatal hematogenous Candida meningoencephalitis animal model. In this review, we found that pediatric data on drug disposition of newer triazoles and echinocandins are lacking, dosing of older antifungals such as fluconazole and amphotericin B products still need optimization in young infants, and that target PK/PD indices need to be

  4. Metabolism and Resistance of Fusarium spp. to the Manzamine Alkaloids via a Putative Retro Pictet-Spengler Reaction and Utility of the Rational Design of Antimalarial and Antifungal Agents

    PubMed Central

    Farr, Lorelei Lucas; Gholipour, Abbas; Wedge, David E.; Hamann, Mark T.

    2014-01-01

    As a part of our continuing investigation of the manzamine alkaloids we studied the in vitro activity of the β-carboline containing manzamine alkaloids against Fusarium solani, Fusarium oxysporium, and Fusarium proliferatum by employing several bioassay techniques including one-dimensional direct bioautography, dilution, and plate susceptibility, and microtiter broth assays. In addition, we also studied the metabolism of the manzamine alkaloids by Fusarium spp. in order to facilitate the redesign of the compounds to prevent resistance of Fusarium spp. through metabolism. The present research reveals that the manzamine alkaloids are inactive against Fusarium spp. and the fungi transform manzamines via hydrolysis, reduction, and a retro Pictet-Spengler reaction. This is the first report to demonstrate an enzymatically retro Pictet-Spengler reaction. The results of this study reveal the utility of the rational design of metabolically stable antifungal agents from this class and the development of manzamine alkaloids as antimalarial drugs through the utilization of Fusarium’s metabolic products to reconstruct the molecule. PMID:24553735

  5. The role of azoles in the management of azole-resistant aspergillosis: from the bench to the bedside.

    PubMed

    Seyedmousavi, Seyedmojtaba; Mouton, Johan W; Melchers, Willem J G; Brüggemann, Roger J M; Verweij, Paul E

    2014-07-01

    Azole resistance is an emerging problem in Aspergillus fumigatus and is associated with a high probability of treatment failure. An azole resistance mechanism typically decreases the activity of multiple azole compounds, depending on the mutation. As alternative treatment options are limited and in some isolates the minimum inhibitory concentration (MIC) increases by only a few two-fold dilutions steps, we investigated if voriconazole and posaconazole have a role in treating azole-resistant Aspergillus disease. The relation between resistance genotype and phenotype, pharmacokinetic and pharmacodynamic properties, and (pre)clinical treatment efficacy were reviewed. The results were used to estimate the exposure needed to achieve the pharmacodynamic target for each MIC. For posaconazole adequate exposure can be achieved only for wild type isolates as dose escalation does not allow PD target attainment. However, the new intravenous formulation might result in sufficient exposure to treat isolates with a MIC of 0.5 mg/L. For voriconazole our analysis indicated that the exposure needed to treat infection due to isolates with a MIC of 2 mg/L is feasible and maybe isolates with a MIC of 4 mg/L. However, extreme caution and strict monitoring of drug levels would be required, as the probability of toxicity will also increase. PMID:25066814

  6. Molecular epidemiology and in-vitro antifungal susceptibility of Aspergillus terreus species complex isolates in Delhi, India: evidence of genetic diversity by amplified fragment length polymorphism and microsatellite typing.

    PubMed

    Kathuria, Shallu; Sharma, Cheshta; Singh, Pradeep Kumar; Agarwal, Puneet; Agarwal, Kshitij; Hagen, Ferry; Meis, Jacques F; Chowdhary, Anuradha

    2015-01-01

    Aspergillus terreus is emerging as an etiologic agent of invasive aspergillosis in immunocompromised individuals in several medical centers in the world. Infections due to A. terreus are of concern due to its resistance to amphotericin B, in vivo and in vitro, resulting in poor response to antifungal therapy and high mortality. Herein we examined a large collection of molecularly characterized, geographically diverse A. terreus isolates (n = 140) from clinical and environmental sources in India for the occurrence of cryptic A. terreus species. The population structure of the Indian A. terreus isolates and their association with those outside India was determined using microsatellite based typing (STR) technique and Amplified Fragment Length Polymorphism analysis (AFLP). Additionally, in vitro antifungal susceptibility of A. terreus isolates was determined against 7 antifungals. Sequence analyses of the calmodulin locus identified the recently described cryptic species A. hortai, comprising 1.4% of Aspergillus section Terrei isolates cultured from cases of aspergilloma and probable invasive aspergillosis not reported previously. All the nine markers used for STR typing of A. terreus species complex proved to be highly polymorphic. The presence of high genetic diversity revealing 75 distinct genotypes among 101 Indian A. terreus isolates was similar to the marked heterogeneity noticed in the 47 global A. terreus population exhibiting 38 unique genotypes mainly among isolates from North America and Europe. Also, AFLP analysis showed distinct banding patterns for genotypically diverse A. terreus isolates. Furthermore, no correlation between a particular genotype and amphotericin B susceptibility was observed. Overall, 8% of the A. terreus isolates exhibited low MICs of amphotericin B. All the echinocandins and azoles (voriconazole, posaconazole and isavuconazole) demonstrated high potency against all the isolates. The study emphasizes the need of molecular

  7. Molecular Epidemiology and In-Vitro Antifungal Susceptibility of Aspergillus terreus Species Complex Isolates in Delhi, India: Evidence of Genetic Diversity by Amplified Fragment Length Polymorphism and Microsatellite Typing

    PubMed Central

    Kathuria, Shallu; Sharma, Cheshta; Singh, Pradeep Kumar; Agarwal, Puneet; Agarwal, Kshitij; Hagen, Ferry; Meis, Jacques F.; Chowdhary, Anuradha

    2015-01-01

    Aspergillus terreus is emerging as an etiologic agent of invasive aspergillosis in immunocompromised individuals in several medical centers in the world. Infections due to A. terreus are of concern due to its resistance to amphotericin B, in vivo and in vitro, resulting in poor response to antifungal therapy and high mortality. Herein we examined a large collection of molecularly characterized, geographically diverse A. terreus isolates (n = 140) from clinical and environmental sources in India for the occurrence of cryptic A. terreus species. The population structure of the Indian A. terreus isolates and their association with those outside India was determined using microsatellite based typing (STR) technique and Amplified Fragment Length Polymorphism analysis (AFLP). Additionally, in vitro antifungal susceptibility of A. terreus isolates was determined against 7 antifungals. Sequence analyses of the calmodulin locus identified the recently described cryptic species A. hortai, comprising 1.4% of Aspergillus section Terrei isolates cultured from cases of aspergilloma and probable invasive aspergillosis not reported previously. All the nine markers used for STR typing of A. terreus species complex proved to be highly polymorphic. The presence of high genetic diversity revealing 75 distinct genotypes among 101 Indian A. terreus isolates was similar to the marked heterogeneity noticed in the 47 global A. terreus population exhibiting 38 unique genotypes mainly among isolates from North America and Europe. Also, AFLP analysis showed distinct banding patterns for genotypically diverse A. terreus isolates. Furthermore, no correlation between a particular genotype and amphotericin B susceptibility was observed. Overall, 8% of the A. terreus isolates exhibited low MICs of amphotericin B. All the echinocandins and azoles (voriconazole, posaconazole and isavuconazole) demonstrated high potency against all the isolates. The study emphasizes the need of molecular

  8. Advances in synthetic approach to and antifungal activity of triazoles

    PubMed Central

    Kumar, Nitin; Drabu, Sushma; Sharma, Pramod Kumar

    2011-01-01

    Summary Several five membered ring systems, e.g., triazole, oxadiazole dithiazole and thiadiazole with three heteroatoms at symmetrical or asymmetrical positions have been studied because of their interesting pharmacological properties. In this article our emphasis is on synthetic development and pharmacological activity of the triazole moiety which exhibit a broad spectrum of pharmacological activity such as antifungal, antibacterial, anti-inflammatory and anticancer etc. Triazoles have increased our ability to treat many fungal infections, for example, candidiasis, cryptococcal meningitis, aspergillosis etc. However, mortality due to these infections even with antifungal therapy is still unacceptably high. Therefore, the development of new antifungal agents targeting specific fungal structures or functions is being actively pursued. Rapid developments in molecular mycology have led to a concentrated search for more target antifungals. Although we are entering a new era of antifungal therapy in which we will continue to be challenged by systemic fungal diseases, the options for treatment will have greatly expanded. PMID:21804864

  9. Emerging Threats in Antifungal-Resistant Fungal Pathogens

    PubMed Central

    Sanglard, Dominique

    2016-01-01

    The use of antifungal drugs in the therapy of fungal diseases can lead to the development of antifungal resistance. Resistance has been described for virtually all antifungal agents in diverse pathogens, including Candida and Aspergillus species. The majority of resistance mechanisms have also been elucidated at the molecular level in these pathogens. Drug resistance genes and genome mutations have been identified. Therapeutic choices are limited for the control of fungal diseases, and it is tempting to combine several drugs to achieve better therapeutic efficacy. In the recent years, several novel resistance patterns have been observed, including antifungal resistance originating from environmental sources in Aspergillus fumigatus and the emergence of simultaneous resistance to different antifungal classes (multidrug resistance) in different Candida species. This review will summarize these current trends. PMID:27014694

  10. The Zinc Finger Protein Mig1 Regulates Mitochondrial Function and Azole Drug Susceptibility in the Pathogenic Fungus Cryptococcus neoformans.

    PubMed

    Caza, Mélissa; Hu, Guanggan; Price, Michael; Perfect, John R; Kronstad, James W

    2016-01-01

    The opportunistic pathogen Cryptococcus neoformans causes fungal meningoencephalitis in immunocompromised individuals. In previous studies, we found that the Hap complex in this pathogen represses genes encoding mitochondrial respiratory functions and tricarboxylic acid (TCA) cycle components under low-iron conditions. The orthologous Hap2/3/4/5 complex in Saccharomyces cerevisiae exerts a regulatory influence on mitochondrial functions, and Hap4 is subject to glucose repression via the carbon catabolite repressor Mig1. In this study, we explored the regulatory link between a candidate ortholog of the Mig1 protein and the HapX component of the Hap complex in C. neoformans. This analysis revealed repression of MIG1 by HapX and activation of HAPX by Mig1 under low-iron conditions and Mig1 regulation of mitochondrial functions, including respiration, tolerance for reactive oxygen species, and expression of genes for iron consumption and iron acquisition functions. Consistently with these regulatory functions, a mig1Δ mutant had impaired growth on inhibitors of mitochondrial respiration and inducers of ROS. Furthermore, deletion of MIG1 provoked a dysregulation in nutrient sensing via the TOR pathway and impacted the pathway for cell wall remodeling. Importantly, loss of Mig1 increased susceptibility to fluconazole, thus further establishing a link between azole antifungal drugs and mitochondrial function. Mig1 and HapX were also required together for survival in macrophages, but Mig1 alone had a minimal impact on virulence in mice. Overall, these studies provide novel insights into a HapX/Mig1 regulatory network and reinforce an association between mitochondrial dysfunction and drug susceptibility that may provide new targets for the development of antifungal drugs. IMPORTANCE Fungal pathogens of humans are difficult to treat, and there is a pressing need to identify new targets for antifungal drugs and to obtain a detailed understanding of fungal proliferation in

  11. The Zinc Finger Protein Mig1 Regulates Mitochondrial Function and Azole Drug Susceptibility in the Pathogenic Fungus Cryptococcus neoformans

    PubMed Central

    Caza, Mélissa; Hu, Guanggan; Price, Michael; Perfect, John R.

    2016-01-01

    ABSTRACT The opportunistic pathogen Cryptococcus neoformans causes fungal meningoencephalitis in immunocompromised individuals. In previous studies, we found that the Hap complex in this pathogen represses genes encoding mitochondrial respiratory functions and tricarboxylic acid (TCA) cycle components under low-iron conditions. The orthologous Hap2/3/4/5 complex in Saccharomyces cerevisiae exerts a regulatory influence on mitochondrial functions, and Hap4 is subject to glucose repression via the carbon catabolite repressor Mig1. In this study, we explored the regulatory link between a candidate ortholog of the Mig1 protein and the HapX component of the Hap complex in C. neoformans. This analysis revealed repression of MIG1 by HapX and activation of HAPX by Mig1 under low-iron conditions and Mig1 regulation of mitochondrial functions, including respiration, tolerance for reactive oxygen species, and expression of genes for iron consumption and iron acquisition functions. Consistently with these regulatory functions, a mig1Δ mutant had impaired growth on inhibitors of mitochondrial respiration and inducers of ROS. Furthermore, deletion of MIG1 provoked a dysregulation in nutrient sensing via the TOR pathway and impacted the pathway for cell wall remodeling. Importantly, loss of Mig1 increased susceptibility to fluconazole, thus further establishing a link between azole antifungal drugs and mitochondrial function. Mig1 and HapX were also required together for survival in macrophages, but Mig1 alone had a minimal impact on virulence in mice. Overall, these studies provide novel insights into a HapX/Mig1 regulatory network and reinforce an association between mitochondrial dysfunction and drug susceptibility that may provide new targets for the development of antifungal drugs. IMPORTANCE Fungal pathogens of humans are difficult to treat, and there is a pressing need to identify new targets for antifungal drugs and to obtain a detailed understanding of fungal

  12. In vivo activity of terpinen-4-ol, the main bioactive component of Melaleuca alternifolia Cheel (tea tree) oil against azole-susceptible and -resistant human pathogenic Candida species

    PubMed Central

    Mondello, Francesca; De Bernardis, Flavia; Girolamo, Antonietta; Cassone, Antonio; Salvatore, Giuseppe

    2006-01-01

    Background Recent investigations on the antifungal properties of essential oil of Melaleuca alternifolia Cheel (Tea Tree Oil, TTO) have been performed with reference to the treatment of vaginal candidiasis. However, there is a lack of in vivo data supporting in vitro results, especially regarding the antifungal properties of TTO constituents. Thus, the aim of our study was to investigate the in vitro and the in vivo anti-Candida activity of two critical bioactive constituents of TTO, terpinen-4-ol and 1,8-cineole. Methods Oophorectomized, pseudoestrus rats under estrogen treatment were used for experimental vaginal infection with azole (fluconazole, itraconazole) -susceptible or -resistant strains of C. albicans. All these strains were preliminarily tested for in vitro susceptibility to TTO, terpinen-4-ol and 1,8-cineole for their antifungal properties, using a modification of the CLSI (formerly NCCLS) reference M27-A2 broth micro-dilution method. Results In vitro minimal inhibitory concentrations (MIC90) values were 0.06% (volume/volume) for terpinen-4-ol and 4% (volume/volume) for 1,8-cineole, regardless of susceptibility or resistance of the strains to fluconazole and itraconazole. Fungicidal concentrations of terpinen-4-ol were equivalent to the candidastatic activity. In the rat vaginal infection model, terpinen-4-ol was as active as TTO in accelerating clearance from the vagina of all Candida strains examined. Conclusion Our data suggest that terpinen-4-ol is a likely mediator of the in vitro and in vivo activity of TTO. This is the first in vivo demonstration that terpinen-4-ol could control C. albicans vaginal infections. The purified compound holds promise for the treatment of vaginal candidiasis, and particularly the azole-resistant forms. PMID:17083732

  13. Evaluation of antifungal activity of carbonate and bicarbonate salts alone or in combination with biocontrol agents in control of citrus green mold.

    PubMed

    Zamani, M; Sharifi Tehrani, A; Ali Abadi, A Alizadeh

    2007-01-01

    The aim of this research was to determine if the attacks of green mold on orange could be reduced by edible salts alone or in combination with biocontrol agent. For this purpose toxicity to Pantoea digitatum and practical use of sodium carbonate (SC), sodium bicarbonate (SBC) and potassium carbonate, and potassium bicarbonate alone or in combination with antagonistic bacteria (Pseudomonas fluorescens isolate PN, Bacillus subtilis isolate VHN, Pantoea agglomerans isolate CA) to control green mold were determined. All were fungistatic. SC and SBC were equal and superior to the other salts for control of green mold on oranges inoculated 6h before treatment and were chosen for subsequent trails under cold storage conditions. The biocontrol agents were found completely tolerant to 3% sodium bicarbonate and sodium carbonate at room temperature; although their culturability was reduced by > 1000-fold after 60 min in 1% other salt solutions. Satisfactory results were also obtained with the combined treatment for control of green mold. A significant increase in biocontrol activity of all isolate was observed when combined with sodium carbonate and sodium bicarbonate. The treatments comprising CA combined with SB was as effective as fungicide treatment. Thus, use of sodium bicarbonate treatment at 3% followed by the antagonist P. agglomerans CA could be an alternative to chemical fungicides for control of green mold on oranges. PMID:18396809

  14. Defining the frontiers between antifungal resistance, tolerance and the concept of persistence.

    PubMed

    Delarze, Eric; Sanglard, Dominique

    2015-11-01

    A restricted number of antifungal agents are available for the therapy of fungal diseases. With the introduction of epidemiological cut-off values for each agent in important fungal pathogens based on the distribution of minimal inhibitory concentration (MIC), the distinction between wild type and drug-resistant populations has been facilitated. Antifungal resistance has been described for all currently available antifungal agents in several pathogens and most of the associated resistance mechanisms have been deciphered at the molecular level. Clinical breakpoints for some agents have been proposed and can have predictive value for the success or failure of therapy. Tolerance to antifungals has been a much more ignored area. By definition, tolerance operates at antifungal concentrations above individual intrinsic inhibitory values. Important is that tolerance to antifungal agents favours the emergence of persister cells, which are able to survive antifungal therapy and can cause relapses. Here we will review the current knowledge on antifungal tolerance, its potential mechanisms and also evaluate the role of antifungal tolerance in the efficacy of drug treatments. PMID:26690338

  15. Multiple mechanisms contribute to the development of clinically significant azole resistance in Aspergillus fumigatus

    PubMed Central

    Moye-Rowley, W. S.

    2015-01-01

    Infections caused by the filamentous fungus Aspergillus fumigatus are a significant clinical issue and represent the second most-common form of fungal infection. Azole drugs are effective against this pathogen but resistant isolates are being found more frequently. Infections associated with azole resistant A. fumigatus have a significantly increased mortality making understanding drug resistance in this organism a priority. The target of azole drugs is the lanosterol α-14 demethylase enzyme encoded by the cyp51A gene in A. fumigatus. Mutations in cyp51A have been described that give rise to azole resistance and been argued to be the primary, if not sole, contributor to azole resistance. Here, I discuss recent developments that indicate multiple mechanisms, including increased expression of ATP-binding cassette (ABC) transporter proteins, contribute to azole resistance. ABC transporters are well-established determinants of drug resistance in other fungal pathogens and seem likely to play a similar role in A. fumigatus. PMID:25713565

  16. Evaluation of the Effects of Photodynamic Therapy Alone and Combined with Standard Antifungal Therapy on Planktonic Cells and Biofilms of Fusarium spp. and Exophiala spp.

    PubMed Central

    Gao, Lujuan; Jiang, Shaojie; Sun, Yi; Deng, Meiqi; Wu, Qingzhi; Li, Ming; Zeng, Tongxiang

    2016-01-01

    Infections of Fusarium spp. and Exophiala spp. are often chronic, recalcitrant, resulting in significant morbidity, causing discomfort, disfigurement, social isolation. Systemic disseminations happen in compromised patients, which are often refractory to available antifungal therapies and thereby lead to death. The antimicrobial photodynamic therapy (aPDT) has been demonstrated to effectively inactivate multiple pathogenic fungi and is considered as a promising alternative treatment for mycoses. In the present study, we applied methylene blue (8, 16, and 32 μg/ml) as a photosensitizing agent and light emitting diode (635 ± 10 nm, 12 and 24 J/cm2), and evaluated the effects of photodynamic inactivation on five strains of Fusarium spp. and five strains of Exophiala spp., as well as photodynamic effects on in vitro susceptibility to itraconazole, voriconazole, posaconazole and amphotericin B, both planktonic and biofilm forms. Photodynamic therapy was efficient in reducing the growth of all strains tested, exhibiting colony forming unit-reductions of up to 6.4 log10 and 5.6 log10 against planktonic cultures and biofilms, respectively. However, biofilms were less sensitive since the irradiation time was twice longer than that of planktonic cultures. Notably, the photodynamic effects against Fusarium strains with high minimal inhibitory concentration (MIC) values of ≥16, 4-8, 4-8, and 2-4 μg/ml for itraconazole, voriconazole, posaconazole and amphotericin B, respectively, were comparable or even superior to Exophiala spp., despite Exophiala spp. showed relatively better antifungal susceptibility profile. MIC ranges against planktonic cells of both species were up to 64 times lower after aPDT treatment. Biofilms of both species showed high sessile MIC50 (SMIC50) and SMIC80 of ≥16 μg/ml for all azoles tested and variable susceptibilities to amphotericin B, with SMIC ranging between 1 and 16 μg/ml. Biofilms subjected to aPDT exhibited a distinct reduction in SMIC

  17. Evaluation of the Effects of Photodynamic Therapy Alone and Combined with Standard Antifungal Therapy on Planktonic Cells and Biofilms of Fusarium spp. and Exophiala spp.

    PubMed

    Gao, Lujuan; Jiang, Shaojie; Sun, Yi; Deng, Meiqi; Wu, Qingzhi; Li, Ming; Zeng, Tongxiang

    2016-01-01

    Infections of Fusarium spp. and Exophiala spp. are often chronic, recalcitrant, resulting in significant morbidity, causing discomfort, disfigurement, social isolation. Systemic disseminations happen in compromised patients, which are often refractory to available antifungal therapies and thereby lead to death. The antimicrobial photodynamic therapy (aPDT) has been demonstrated to effectively inactivate multiple pathogenic fungi and is considered as a promising alternative treatment for mycoses. In the present study, we applied methylene blue (8, 16, and 32 μg/ml) as a photosensitizing agent and light emitting diode (635 ± 10 nm, 12 and 24 J/cm(2)), and evaluated the effects of photodynamic inactivation on five strains of Fusarium spp. and five strains of Exophiala spp., as well as photodynamic effects on in vitro susceptibility to itraconazole, voriconazole, posaconazole and amphotericin B, both planktonic and biofilm forms. Photodynamic therapy was efficient in reducing the growth of all strains tested, exhibiting colony forming unit-reductions of up to 6.4 log10 and 5.6 log10 against planktonic cultures and biofilms, respectively. However, biofilms were less sensitive since the irradiation time was twice longer than that of planktonic cultures. Notably, the photodynamic effects against Fusarium strains with high minimal inhibitory concentration (MIC) values of ≥16, 4-8, 4-8, and 2-4 μg/ml for itraconazole, voriconazole, posaconazole and amphotericin B, respectively, were comparable or even superior to Exophiala spp., despite Exophiala spp. showed relatively better antifungal susceptibility profile. MIC ranges against planktonic cells of both species were up to 64 times lower after aPDT treatment. Biofilms of both species showed high sessile MIC50 (SMIC50) and SMIC80 of ≥16 μg/ml for all azoles tested and variable susceptibilities to amphotericin B, with SMIC ranging between 1 and 16 μg/ml. Biofilms subjected to aPDT exhibited a distinct reduction in

  18. Interaction of gelatin with polyenes modulates antifungal activity and biocompatibility of electrospun fiber mats

    PubMed Central

    Lakshminarayanan, Rajamani; Sridhar, Radhakrishnan; Loh, Xian Jun; Nandhakumar, Muruganantham; Barathi, Veluchamy Amutha; Kalaipriya, Madhaiyan; Kwan, Jia Lin; Liu, Shou Ping; Beuerman, Roger Wilmer; Ramakrishna, Seeram

    2014-01-01

    Topical application of antifungals does not have predictable or well-controlled release characteristics and requires reapplication to achieve therapeutic local concentration in a reasonable time period. In this article, the efficacy of five different US Food and Drug Administration-approved antifungal-loaded (amphotericin B, natamycin, terbinafine, fluconazole, and itraconazole) electrospun gelatin fiber mats were compared. Morphological studies show that incorporation of polyenes resulted in a two-fold increase in fiber diameter and the mats inhibit the growth of yeasts and filamentous fungal pathogens. Terbinafine-loaded mats were effective against three filamentous fungal species. Among the two azole antifungals compared, the itraconazole-loaded mat was potent against Aspergillus strains. However, activity loss was observed for fluconazole-loaded mats against all of the test organisms. The polyene-loaded mats displayed rapid candidacidal activities as well. Biophysical and rheological measurements indicate strong interactions between polyene antifungals and gelatin matrix. As a result, the polyenes stabilized the triple helical conformation of gelatin and the presence of gelatin decreased the hemolytic activity of polyenes. The polyene-loaded fiber mats were noncytotoxic to primary human corneal and sclera fibroblasts. The reduction of toxicity with complete retention of activity of the polyene antifungal-loaded gelatin fiber mats can provide new opportunities in the management of superficial skin infections. PMID:24920895

  19. Antifungal Compounds from Cyanobacteria

    PubMed Central

    Shishido, Tânia K.; Humisto, Anu; Jokela, Jouni; Liu, Liwei; Wahlsten, Matti; Tamrakar, Anisha; Fewer, David P.; Permi, Perttu; Andreote, Ana P. D.; Fiore, Marli F.; Sivonen, Kaarina

    2015-01-01

    Cyanobacteria are photosynthetic prokaryotes found in a range of environments. They are infamous for the production of toxins, as well as bioactive compounds, which exhibit anticancer, antimicrobial and protease inhibition activities. Cyanobacteria produce a broad range of antifungals belonging to structural classes, such as peptides, polyketides and alkaloids. Here, we tested cyanobacteria from a wide variety of environments for antifungal activity. The potent antifungal macrolide scytophycin was detected in Anabaena sp. HAN21/1, Anabaena cf. cylindrica PH133, Nostoc sp. HAN11/1 and Scytonema sp. HAN3/2. To our knowledge, this is the first description of Anabaena strains that produce scytophycins. We detected antifungal glycolipopeptide hassallidin production in Anabaena spp. BIR JV1 and HAN7/1 and in Nostoc spp. 6sf Calc and CENA 219. These strains were isolated from brackish and freshwater samples collected in Brazil, the Czech Republic and Finland. In addition, three cyanobacterial strains, Fischerella sp. CENA 298, Scytonema hofmanni PCC 7110 and Nostoc sp. N107.3, produced unidentified antifungal compounds that warrant further characterization. Interestingly, all of the strains shown to produce antifungal compounds in this study belong to Nostocales or Stigonematales cyanobacterial orders. PMID:25871291

  20. How do azoles inhibit cytochrome P450 enzymes? A density functional study.

    PubMed

    Balding, Philip R; Porro, Cristina S; McLean, Kirsty J; Sutcliffe, Michael J; Maréchal, Jean-Didier; Munro, Andrew W; de Visser, Sam P

    2008-12-18

    To examine how azole inhibitors interact with the heme active site of the cytochrome P450 enzymes, we have performed a series of density functional theory studies on azole binding. These are the first density functional studies on azole interactions with a heme center and give fundamental insight into how azoles inhibit the catalytic function of P450 enzymes. Since azoles come in many varieties, we tested three typical azole motifs representing a broad range of azole and azole-type inhibitors: methylimidazolate, methyltriazolate, and pyridine. These structural motifs represent typical azoles, such as econazole, fluconazole, and metyrapone. The calculations show that azole binding is a stepwise mechanism whereby first the water molecule from the resting state of P450 is released from the sixth binding site of the heme to create a pentacoordinated active site followed by coordination of the azole nitrogen to the heme iron. This process leads to the breaking of a hydrogen bond between the resting state water molecule and the approaching inhibitor molecule. Although, formally, the water molecule is released in the first step of the reaction mechanism and a pentacoordinated heme is created, this does not lead to an observed spin state crossing. Thus, we show that release of a water molecule from the resting state of P450 enzymes to create a pentacoordinated heme will lead to a doublet to quartet spin state crossing at an Fe-OH(2) distance of approximately 3.0 A, while the azole substitution process takes place at shorter distances. Azoles bind heme with significantly stronger binding energies than a water molecule, so that these inhibitors block the catalytic cycle of the enzyme and prevent oxygen binding and the catalysis of substrate oxidation. Perturbations within the active site (e.g., a polarized environment) have little effect on the relative energies of azole binding. Studies with an extra hydrogen-bonded ethanol molecule in the model, mimicking the active site

  1. Ibuprofen reverts antifungal resistance on Candida albicans showing overexpression of CDR genes.

    PubMed

    Ricardo, Elisabete; Costa-de-Oliveira, Sofia; Dias, Ana Silva; Guerra, José; Rodrigues, Acácio Gonçalves; Pina-Vaz, Cidália

    2009-06-01

    Several mechanisms may be associated with Candida albicans resistance to azoles. Ibuprofen was described as being able to revert resistance related to efflux activity in Candida. The aim of this study was to uncover the molecular base of antifungal resistance in C. albicans clinical strains that could be reverted by ibuprofen. Sixty-two clinical isolates and five control strains of C. albicans were studied: the azole susceptibility phenotype was determined according to the Clinical Laboratory for Standards Institute, M27-A2 protocol and minimal inhibitory concentration values were recalculated with ibuprofen (100 microg mL(-1)); synergistic studies between fluconazole and FK506, a Cdr1p inhibitor, were performed using an agar disk diffusion assay and were compared with ibuprofen results. Gene expression was quantified by real-time PCR, with and without ibuprofen, regarding CDR1, CDR2, MDR1, encoding for efflux pumps, and ERG11, encoding for azole target protein. A correlation between susceptibility phenotype and resistance gene expression profiles was determined. Ibuprofen and FK506 showed a clear synergistic effect when combined with fluconazole. Resistant isolates reverting to susceptible after incubation with ibuprofen showed CDR1 and CDR2 overexpression especially of the latter. Conversely, strains that did not revert displayed a remarkable increase in ERG11 expression along with CDR genes. Ibuprofen did not alter resistance gene expression significantly (P>0.05), probably acting as a Cdrp blocker. PMID:19416368

  2. Antifungal activity of polymer-based copper nanocomposite coatings

    NASA Astrophysics Data System (ADS)

    Cioffi, Nicola; Torsi, Luisa; Ditaranto, Nicoletta; Sabbatini, Luigia; Zambonin, Pier Giorgio; Tantillo, Giuseppina; Ghibelli, Lina; D'Alessio, Maria; Bleve-Zacheo, Teresa; Traversa, Enrico

    2004-09-01

    Eukaryotes, such as fungi, can be harmful pathogen agents, and the control of their bioactivity is critical as humans are eukaryote organisms, too. Here, copper/polymer nanocomposites are proposed as antifungal spinnable coatings with controlled copper-releasing properties. The tests of the bioactivity show that fungal growth is inhibited on the nanocomposite-coated plates, and the antifungal activity can be modulated by controlling the Cu nanoparticle loading.

  3. Antibacterial and antifungal activity of Indonesian ethnomedical plants.

    PubMed

    Goun, E; Cunningham, G; Chu, D; Nguyen, C; Miles, D

    2003-09-01

    Methylene chloride and methanol extracts of 20 Indonesian plants with ethnomedical uses have been assessed for in vitro antibacterial and antifungal properties by disk diffusion method. Extracts of the six plants: Terminalia catappa, Swietenia mahagoni Jacq., Phyllanthus acuminatus, Ipomoea spp., Tylophora asthmatica and Hyptis brevipes demonstrated high activity in this bioassay system. These findings should stimulate the search for novel, natural product such as new antibacterial and antifungal agents. PMID:12946723

  4. Production and characterization of Iturinic lipopeptides as antifungal agents and biosurfactants produced by a marine pinctada martensii-derived Bacillus mojavensis B0621A.

    PubMed

    Ma, Zongwang; Hu, Jiangchun

    2014-06-01

    Bacillus mojavensis B0621A was isolated from a pearl oyster Pinctada martensii collected from South China Sea. While screening for cyclic lipopeptides potentially useful as lead compounds for biological control against soil-bone fungal plant pathogens, three lipopeptides were isolated and purified from the fermentation broth of B. mojavensis B0621A via vacuum flash chromatography coupled with reversed-phase high performance liquid chromatography (RP-HPLC). The structural characterization and identification of these cyclic lipopeptides were performed by tandem mass spectrometry (MS/MS) combined with gas chromatography-mass spectrometry (GC-MS) analysis as well as chemical degradation. These lipopeptides were finally characterized as homologues of mojavensins, which contained identical amino acids back bones of asparagine1, tyrosine2, asparagine3, glutamine4, proline5, asparagine6, and asparagine7 and differed from each other by their saturated β-amino fatty acid chain residues, namely, iso-C14 mojavensin, iso-C16 mojavensin, and anteiso-C17 mojavensin, respectively. All lipopeptide isomers, especially iso-C16 mojavensin and anteiso-C17 mojavensin, displayed moderate antagonism and dose-dependent activity against several formae speciales of Fusarium oxysporum and presented surface tension activities. These properties demonstrated that the lipopeptides produced by B. mojavensis B0621A may be useful as biological control agent to fungal plant pathogens. PMID:24699814

  5. Soluble material secreted from Penicillium chrysogenum isolate exhibits antifungal activity against Cryphonectria parasitica- the causative agent of the American Chestnut Blight

    PubMed Central

    Florjanczyk, Aleksandr; Barnes, Rebecca; Kenney, Adam; Horzempa, Joseph

    2016-01-01

    The American chestnut (Castanea dentata) was once the dominant canopy tree along the eastern region of the United States. Cryphonectria parasitica, the causative agent of chestnut blight, was introduced from Asia in the early 1900's, and obliterated the chestnut population within 50 years. We sought to identify environmental microbes capable of producing factors that were fungicidal or inhibited growth of C. parasitica in the hopes developing a biological control of chestnut blight. We isolated a filamentous fungus that significantly inhibited the growth of C. parasitica upon co-cultivation. Extracellular fractions of this fungal isolate prevented C. parasitica growth, indicating that a potential fungicide was produced by the novel isolate. Sequence analysis of 18S rRNA identified this inhibitory fungus as Penicillium chrysogenum. Furthermore, these extracellular fractions were tested as treatments for blight in vivo using chestnut saplings. Scarred saplings that were treated with the P. chrysogenum extracellular fractions healed subjectively better than those without treatment when inoculated with C. parasitica. These data suggest that material secreted by P. chrysogenum could be used as a treatment for the American chestnut blight. This work may assist the reclamation of the American chestnut in association with breeding programs and blight attenuation. Specifically, treatment of small groves under the right conditions may allow them to remain blight free. Future work will explore the mechanism of action and specific target of the extracellular fraction. PMID:27274909

  6. Mechanism of inhibition of estrogen biosynthesis by azole fungicides.

    PubMed

    Egbuta, Chinaza; Lo, Jessica; Ghosh, Debashis

    2014-12-01

    Biosynthesis of estrogens from androgens is catalyzed by cytochrome P450 aromatase. Aromatase inhibition by the triazole compounds letrozole (LTZ) and anastrozole is a prevalent therapy for estrogen-dependent postmenopausal breast cancer. Azoles are widely used as agricultural fungicides and antimycotic drugs that target 14α-demethylase. Some were previously shown to inhibit aromatase, thereby raising the possibility of endocrine disruptive effects. However, mechanistic analysis of their inhibition has never been undertaken. We have evaluated the inhibitory effects of 3 common fungicides, bifonazole, imazalil, and flusilazole, in human aromatase purified from placenta and compared them with LTZ, the most potent inhibitor of aromatase. Bifonazole exhibits strong inhibitory effects with an IC50 of 270nM and Ki (Michaeles-Menten inhibition constant) of 68nM, compared with 10nM and 13nM, respectively, for LTZ. The IC50 and Ki are 1100nM and 278nM for imazilil and 3200nM and 547nM for flusilazole, respectively. Analyses of inhibition kinetics suggest that the modes of inhibition by azole fungicides are mixed or competitive, whereas LTZ inhibition could be noncompetitive or mixed. We interpret the inhibition mechanism in the context of the x-ray structure of aromatase-androstenedione complex. Structural data show that aromatase has 3 binding pockets in relation to the heme. The substrate-binding cavity at the heme-distal site closely compliments the structures of the natural substrate, androstenedione, and steroidal aromatase inhibitors. Because the structures of LTZ and the azole fungicides are entirely dissimilar to the androstenedione backbone, the azoles possibly inhibit by binding to a structurally rearranged active site, the 2 other catalytically important sites, or both, in agreement with the kinetics data. PMID:25243857

  7. Antifungal susceptibility and molecular typing of 115 Candida albicans isolates obtained from vulvovaginal candidiasis patients in 3 Shanghai maternity hospitals.

    PubMed

    Ying, Chunmei; Zhang, Hongju; Tang, Zhenhua; Chen, Huifen; Gao, Jing; Yue, Chaoyan

    2016-05-01

    In our multicenter study, we studied the distribution ofCandidaspecies in vulvovaginal candidiasis patients and investigated antifungal susceptibility profile and genotype ofCandida albicansin vaginal swab. A total of 115Candida albicansstrains were detected in 135 clinical isolates. Minimum inhibitory concentration determinations showed that 83% and 81% of the 115Candida albicansstrains were susceptible to fluconazole and voriconazole. Randomly amplified polymorphic DNA analysis (RAPD) was applied to identify clonally related isolates from different patients at the local level. All tested strains were classified into genotype A (77.4%), genotype B (18.3%), and genotype C (4.3%). Genotype A was further classified into five subtypes and genotype B into two subtypes.Candida albicanswas the dominant pathogen of vulvovaginal candidiasis, the majority belonging to genotype A in this study. Exposure to azoles is a risk factor for the emergence of azole resistance amongCandida albicansisolated from VVC patients. PMID:26468549

  8. Structural basis for heterogeneous phenotype of ERG11 dependent Azole resistance in C.albicans clinical isolates.

    PubMed

    Debnath, Surajit; Addya, Soma

    2014-01-01

    Correlating antifungal Azole drug resistance and mis-sense mutations of ERG11 has been paradoxical in pathogenic yeast Candida albicans. Amino acid substitutions (single or multiple) are frequent on ERG11, a membrane bound enzyme of Ergosterol biosynthesis pathway. Presence or absence of mutations can not sufficiently predict susceptibility. To analyze role of mis-sense mutations on Azole resistance energetically optimized, structurally validated homology model of wild C.albicans ERG11 using eukaryotic template was generated. A Composite Search Approach is proposed to identify vital residues for interaction at 3D active site. Structural analysis of catalytic groove, dynamics of substrate access channels and proximity of Heme prosthetic group characterized ERG11 active site. Several mis-sense mutations of ERG11 reported in C.albicans clinical isolates were selected through a stringent criterion and modeled. ERG11 mutants subsequently subjected to a four tier comparative biophysical analysis. This study indicates (i) critical interactions occur with residues at anterior part of 3D catalytic groove and substitution of these vital residues alters local geometry causing considerable change in catalytic pocket dimension. (ii) Substitutions of vital residues lead to confirmed resistance in clinical isolates that may be resultant to changed geometry of catalytic pocket. (iii)These substitutions also impart significant energetic changes on C.albicans ERG11 and (iv) include detectable dynamic fluctuations on the mutants. (v)Mis-sense mutations on the vital residues of the active site and at the vicinity of Heme prosthetic group are less frequent compared to rest of the enzyme. This large scale mutational study can aid to characterize the mutants in clinical isolates. PMID:25512882

  9. Optimization of Polyene-Azole Combination Therapy against Aspergillosis Using an In Vitro Pharmacokinetic-Pharmacodynamic Model

    PubMed Central

    Siopi, Maria; Siafakas, Nikolaos; Vourli, Sophia; Zerva, Loukia

    2015-01-01

    Although amphotericin B-azole combination therapy has traditionally been questioned due to potential antagonistic interactions, it is often used successfully to treat refractory invasive aspergillosis. So far, pharmacodynamic (PD) interactions have been assessed with conventional in vitro tests, which do not mimic human serum concentrations and animal models using limited doses. We therefore simulated the human serum concentration profiles of amphotericin B and voriconazole in an in vitro dialysis/diffusion closed pharmacokinetic-pharmacodynamic (PK-PD) model and studied the pharmacodynamic interactions against an azole-resistant and an azole-susceptible Aspergillus fumigatus isolate, using Bliss independence and canonical mixture response surface analyses. Amphotericin B dosing regimens with the drug administered every 24 h (q24h) were combined with voriconazole q12h dosing regimens. In vitro PK-PD combination data were then combined with human PK data by using Monte Carlo analysis. The target attainment rate and the serum concentration/MIC ratio were calculated for isolates with different MICs. Synergy (20 to 31%) was observed at low amphotericin B-high voriconazole exposures, whereas antagonism (−6 to −16%) was found at high amphotericin B-low voriconazole exposures for both isolates. Combination therapy resulted in 17 to 48% higher target attainment rates than those of monotherapy regimens for isolates with voriconazole/amphotericin B MICs of 1 to 4 mg/liter. Optimal activity was found for combination regimens with a 1.1 total minimum concentration of drug in serum (tCmin)/MIC ratio for voriconazole and a 0.5 total maximum concentration of drug in serum (tCmax)/MIC ratio for amphotericin B, whereas the equally effective monotherapy regimens required a voriconazole tCmin/MIC ratio of 1.8 and an amphotericin B tCmax/MIC ratio of 2.8. Amphotericin B-voriconazole combination regimens were more effective than monotherapy regimens. Therapeutic drug monitoring can

  10. Stepwise emergence of azole, echinocandin and amphotericin B multidrug resistance in vivo in Candida albicans orchestrated by multiple genetic alterations

    PubMed Central

    Jensen, Rasmus Hare; Astvad, Karen Marie Thyssen; Silva, Luis Vale; Sanglard, Dominique; Jørgensen, Rene; Nielsen, Kristian Fog; Mathiasen, Estella Glintborg; Doroudian, Ghazalel; Perlin, David Scott; Arendrup, Maiken Cavling

    2015-01-01

    Objectives The objective of this study was to characterize the underlying molecular mechanisms in consecutive clinical Candida albicans isolates from a single patient displaying stepwise-acquired multidrug resistance. Methods Nine clinical isolates (P-1 to P-9) were susceptibility tested by EUCAST EDef 7.2 and Etest. P-4, P-5, P-7, P-8 and P-9 were available for further studies. Relatedness was evaluated by MLST. Additional genes were analysed by sequencing (including FKS1, ERG11, ERG2 and TAC1) and gene expression by quantitative PCR (CDR1, CDR2 and ERG11). UV-spectrophotometry and GC-MS were used for sterol analyses. In vivo virulence was determined in the insect model Galleria mellonella and evaluated by log-rank Mantel–Cox tests. Results P-1 + P-2 were susceptible, P-3 + P-4 fluconazole resistant, P-5 pan-azole resistant, P-6 + P-7 pan-azole and echinocandin resistant and P-8 + P-9 MDR. MLST supported genetic relatedness among clinical isolates. P-4 harboured four changes in Erg11 (E266D, G307S, G450E and V488I), increased expression of ERG11 and CDR2 and a change in Tac1 (R688Q). P-5, P-7, P-8 and P-9 had an additional change in Erg11 (A61E), increased expression of CDR1, CDR2 and ERG11 (except for P-7) and a different amino acid change in Tac1 (R673L). Echinocandin-resistant isolates harboured the Fks1 S645P alteration. Polyene-resistant P-8 + P-9 lacked ergosterol and harboured a frameshift mutation in ERG2 (F105SfsX23). Virulence was attenuated (but equivalent) in the clinical isolates, but higher than in the azole- and echinocandin-resistant unrelated control strain. Conclusions C. albicans demonstrates a diverse capacity to adapt to antifungal exposure. Potentially novel resistance-inducing mutations in TAC1, ERG11 and ERG2 require independent validation. PMID:26017038

  11. Posttreatment Antifungal Resistance among Colonizing Candida Isolates in Candidemia Patients: Results from a Systematic Multicenter Study.

    PubMed

    Jensen, R H; Johansen, H K; Søes, L M; Lemming, L E; Rosenvinge, F S; Nielsen, L; Olesen, B; Kristensen, L; Dzajic, E; Astvad, K M T; Arendrup, M C

    2016-03-01

    The prevalence of intrinsic and acquired resistance among colonizing Candida isolates from patients after candidemia was investigated systematically in a 1-year nationwide study. Patients were treated at the discretion of the treating physician. Oral swabs were obtained after treatment. Species distributions and MIC data were investigated for blood and posttreatment oral isolates from patients exposed to either azoles or echinocandins for <7 or ≥ 7 days. Species identification was confirmed using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and internal transcribed spacer (ITS) sequencing, susceptibility was examined by EUCAST EDef 7.2 methodology, echinocandin resistance was examined by FKS sequencing, and genetic relatedness was examined by multilocus sequence typing (MLST). One hundred ninety-three episodes provided 205 blood and 220 oral isolates. MLST analysis demonstrated a genetic relationship for 90% of all paired blood and oral isolates. Patients exposed to azoles for ≥ 7 days (n = 93) had a significantly larger proportion of species intrinsically less susceptible to azoles (particularly Candida glabrata) among oral isolates than among initial blood isolates (36.6% versus 12.9%; P < 0.001). A similar shift toward species less susceptible to echinocandins among 85 patients exposed to echinocandins for ≥ 7 days was not observed (4.8% of oral isolates versus 3.2% of blood isolates; P > 0.5). Acquired resistance in Candida albicans was rare (<5%). However, acquired resistance to fluconazole (29.4%; P < 0.05) and anidulafungin (21.6%; P < 0.05) was common in C. glabrata isolates from patients exposed to either azoles or echinocandins. Our findings suggest that the colonizing mucosal microbiota may be an unrecognized reservoir of resistant Candida species, especially C. glabrata, following treatment for candidemia. The resistance rates were high, raising concern in general for patients exposed to antifungal

  12. In vitro antifungal activity of topical and systemic antifungal drugs against Malassezia species.

    PubMed

    Carrillo-Muñoz, Alfonso Javier; Rojas, Florencia; Tur-Tur, Cristina; de Los Ángeles Sosa, María; Diez, Gustavo Ortiz; Espada, Carmen Martín; Payá, María Jesús; Giusiano, Gustavo

    2013-09-01

    The strict nutritional requirements of Malassezia species make it difficult to test the antifungal susceptibility. Treatments of the chronic and recurrent infections associated with Malassezia spp. are usually ineffective. The objective of this study was to obtain in vitro susceptibility profile of 76 clinical isolates of Malassezia species against 16 antifungal drugs used for topical or systemic treatment. Isolates were identified by restriction fragment length polymorphism. Minimal inhibitory concentrations (MIC) were obtained by a modified microdilution method based on the Clinical Laboratory Standards Institute reference document M27-A3. The modifications allowed a good growth of all tested species. High in vitro antifungal activity of most tested drugs was observed, especially triazole derivatives, except for fluconazole which presented the highest MICs and widest range of concentrations. Ketoconazole and itraconazole demonstrated a great activity. Higher MICs values were obtained with Malassezia furfur indicating a low susceptibility to most of the antifungal agents tested. Malassezia sympodialis and Malassezia pachydermatis were found to be more-susceptible species than M. furfur, Malassezia globosa, Malassezia slooffiae and Malassezia restricta. Topical substances were also active but provide higher MICs than the compounds for systemic use. The differences observed in the antifungals activity and interspecies variability demonstrated the importance to studying the susceptibility profile of each species to obtain reliable information for defining an effective treatment regimen. PMID:23496653

  13. Uptake of azoles by lamb's lettuce (Valerianella locusta L.) grown in hydroponic conditions.

    PubMed

    García-Valcárcel, Ana I; Loureiro, Iñigo; Escorial, Concepción; Molero, Encarnación; Tadeo, José L

    2016-02-01

    An uptake and translocation study of azole compounds was performed in lamb's lettuce (Valerianella locusta L.) grown in nutrient solution fortified with different azoles. Three azoles, (clotrimazole, fluconazole and propiconazole), which have different physico-chemical properties and are ubiquitous in the aquatic environment, were the compounds selected. An analytical method, based on matrix solid phase dispersion (MSPD) followed by LC-MS/MS determination, was developed to quantify these compounds in aqueous solution and in roots and leaves. The physicochemical properties of azoles are the main factors governing the uptake and plant accumulation. These azoles were detected in leaves indicating their transport within lamb's lettuce. Translocation from nutrient solution to the aerial part of lamb's lettuce was found to be highly dependent on the hydrophobicity of the azole. Clotrimazole accumulates in roots causing necrosis in roots and leaves, whereas fluconazole was the azole with the highest concentration in leaves without causing apparent phytotoxicity symptoms. The assessment of the levels of these azoles in leaves indicates that the risk for human health is negligible. PMID:26513529

  14. Effects of the azole fungicide imazalil on the fathead minnow (Pimephales promelas) steroidogenesis pathway

    EPA Science Inventory

    Azole fungicides, used for both agriculture and human therapeutic applications may disrupt endocrine function of aquatic life. Azole fungicides are designed to inhibit the fungal enzyme lanosterol 14 á-demethylase (cytochrome P450 [CYP] 51). However, they can also interact...

  15. Benzoic acid derivatives with improved antifungal activity: Design, synthesis, structure-activity relationship (SAR) and CYP53 docking studies.

    PubMed

    Berne, Sabina; Kovačič, Lidija; Sova, Matej; Kraševec, Nada; Gobec, Stanislav; Križaj, Igor; Komel, Radovan

    2015-08-01

    Previously, we identified CYP53 as a fungal-specific target of natural phenolic antifungal compounds and discovered several inhibitors with antifungal properties. In this study, we performed similarity-based virtual screening and synthesis to obtain benzoic acid-derived compounds and assessed their antifungal activity against Cochliobolus lunatus, Aspergillus niger and Pleurotus ostreatus. In addition, we generated structural models of CYP53 enzyme and used them in docking trials with 40 selected compounds. Finally, we explored CYP53-ligand interactions and identified structural elements conferring increased antifungal activity to facilitate the development of potential new antifungal agents that specifically target CYP53 enzymes of animal and plant pathogenic fungi. PMID:26154240

  16. Optimization of Spore and Antifungal Lipopeptide Production during the Solid State Fermentation of Bacillus subtilis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacillus subtilis strain TrigoCor 1448 was grown on wheat middlings in 0.5-liter solid state fermentation (SSF) bioreactors for the production of an antifungal biological control agent. Total antifungal activity was quantified using a 96-well microplate bioassay against the plant pathogen Fusarium ...

  17. Microbiological screening of Irish patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy reveals persistence of Candida albicans strains, gradual reduction in susceptibility to azoles, and incidences of clinical signs of oral candidiasis without culture evidence.

    PubMed

    McManus, Brenda A; McGovern, Eleanor; Moran, Gary P; Healy, Claire M; Nunn, June; Fleming, Pádraig; Costigan, Colm; Sullivan, Derek J; Coleman, David C

    2011-05-01

    Patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) are prone to chronic mucocutaneous candidiasis, which is often treated with azoles. The purpose of this study was to characterize the oral Candida populations from 16 Irish APECED patients, who comprise approximately half the total number identified in Ireland, and to examine the effect of intermittent antifungal therapy on the azole susceptibility patterns of Candida isolates. Patients attended between one and four clinical evaluations over a 5-year period, providing oral rinses and/or oral swab samples each time. Candida was recovered from 14/16 patients, and Candida albicans was the only Candida species identified. Interestingly, clinical diagnosis of candidiasis did not correlate with microbiological evidence of Candida infection at 7/22 (32%) clinical assessments. Multilocus sequence typing analysis of C. albicans isolates recovered from the same patients on separate occasions identified the same sequence type each time. Fluconazole resistance was detected in isolates from one patient, and isolates exhibiting a progressive reduction in itraconazole and/or fluconazole susceptibility were identified in a further 3/16 patients, in each case correlating with the upregulation of CDR- and MDR-encoded efflux pumps. Mutations were also identified in the ERG11 and the TAC1 genes of isolates from these four patients; some of these mutations have previously been associated with azole resistance. The findings suggest that alternative Candida treatment options, other than azoles such as chlorhexidine, should be considered in APECED patients and that clinical diagnosis of oral candidiasis should be confirmed by culture prior to the commencement of anti-Candida therapy. PMID:21367996

  18. Microbiological Screening of Irish Patients with Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy Reveals Persistence of Candida albicans Strains, Gradual Reduction in Susceptibility to Azoles, and Incidences of Clinical Signs of Oral Candidiasis without Culture Evidence▿†

    PubMed Central

    McManus, Brenda A.; McGovern, Eleanor; Moran, Gary P.; Healy, Claire M.; Nunn, June; Fleming, Pádraig; Costigan, Colm; Sullivan, Derek J.; Coleman, David C.

    2011-01-01

    Patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) are prone to chronic mucocutaneous candidiasis, which is often treated with azoles. The purpose of this study was to characterize the oral Candida populations from 16 Irish APECED patients, who comprise approximately half the total number identified in Ireland, and to examine the effect of intermittent antifungal therapy on the azole susceptibility patterns of Candida isolates. Patients attended between one and four clinical evaluations over a 5-year period, providing oral rinses and/or oral swab samples each time. Candida was recovered from 14/16 patients, and Candida albicans was the only Candida species identified. Interestingly, clinical diagnosis of candidiasis did not correlate with microbiological evidence of Candida infection at 7/22 (32%) clinical assessments. Multilocus sequence typing analysis of C. albicans isolates recovered from the same patients on separate occasions identified the same sequence type each time. Fluconazole resistance was detected in isolates from one patient, and isolates exhibiting a progressive reduction in itraconazole and/or fluconazole susceptibility were identified in a further 3/16 patients, in each case correlating with the upregulation of CDR- and MDR-encoded efflux pumps. Mutations were also identified in the ERG11 and the TAC1 genes of isolates from these four patients; some of these mutations have previously been associated with azole resistance. The findings suggest that alternative Candida treatment options, other than azoles such as chlorhexidine, should be considered in APECED patients and that clinical diagnosis of oral candidiasis should be confirmed by culture prior to the commencement of anti-Candida therapy. PMID:21367996

  19. Antifungal Activity of Maytenin and Pristimerin

    PubMed Central

    Gullo, Fernanda P.; Sardi, Janaina C. O.; Santos, Vânia A. F. F. M.; Sangalli-Leite, Fernanda; Pitangui, Nayla S.; Rossi, Suélen A.; de Paula e Silva, Ana C. A.; Soares, Luciana A.; Silva, Julhiany F.; Oliveira, Haroldo C.; Furlan, Maysa; Silva, Dulce H. S.; Bolzani, Vanderlan S.; Mendes-Giannini, Maria José S.; Fusco-Almeida, Ana Marisa

    2012-01-01

    Fungal infections in humans have increased alarmingly in recent years, particularly in immunocompromised individuals. Among the infections systemic candidiasis, aspergillosis, cryptococcosis, paracoccidioidomycosis, and histoplasmosis mortality are more prevalent and more severe in humans. The current high incidence of dermatophytosis is in humans, especially as the main etiologic agents Trichophyton rubrum and Trichophyton mentagrophytes. Molecules pristimerin and maytenin obtained from the plant Maytenus ilicifolia (Celastraceae) are known to show various pharmacological activities. This study aimed to evaluate the spectrum of antifungal activity of maytenin and pristimerin and their cytotoxicity in human keratinocytes (NOK cells of the oral mucosa). It was concluded that the best spectrum of antifungal activity has been shown to maytenin with MIC varying from 0.12 to 125 mg/L, although it is also active with pristimerin MIC ranging between 0.12 and 250 mg/L. Regarding the toxicity, both showed to have high IC50. The SI showed high pristimerin against some species of fungi, but SI maytenin was above 1.0 for all fungi tested, showing a selective action of fungi. However, when comparing the two substances, maytenin also showed better results. The two molecules can be a possible prototype with a broad spectrum of action for the development of new antifungal agents. PMID:22675379

  20. In vitro antifungal activity and mechanism of essential oil from fennel (Foeniculum vulgare L.) on dermatophyte species.

    PubMed

    Zeng, Hong; Chen, Xinping; Liang, Jingnan

    2015-01-01

    Fennel seed essential oil (FSEO) is a plant-derived natural therapeutic against dermatophytes. In this study, the antifungal effects of FSEO were investigated from varied aspects, such as MIC and minimum fungicidal concentration, mycelia growth, spore germination and biomass. The results indicated that FSEO had potent antifungal activities on Trichophyton rubrum ATCC 40051, Trichophyton tonsurans 10-0400, Microsporum gypseum 44693-1 and Trichophyton mentagrophytes 10-0060, which is better than the commonly used antifungal agents fluconazole and amphotericin B. Flow cytometry and transmission electron microscopy experiments suggested that the antifungal mechanism of FSEO was to damage the plasma membrane and intracellular organelles. Further study revealed that it could also inhibit the mitochondrial enzyme activities, such as succinate dehydrogenase, malate dehydrogenase and ATPase. With better antifungal activity than the commonly used antifungal agents and less possibility of inducing drug resistance, FSEO could be used as a potential antidermatophytic agent. PMID:25351709

  1. Antifungal Susceptibilities of Bloodstream Isolates of Candida Species from Nine Hospitals in Korea: Application of New Antifungal Breakpoints and Relationship to Antifungal Usage

    PubMed Central

    Won, Eun Jeong; Shin, Jong Hee; Choi, Min Ji; Lee, Wee Gyo; Park, Yeon-Joon; Uh, Young; Kim, Shine-Young; Lee, Mi-Kyung; Kim, Soo Hyun; Shin, Myung Geun; Suh, Soon Pal; Ryang, Dong Wook

    2015-01-01

    We applied the new clinical breakpoints (CBPs) of the Clinical and Laboratory Standards Institute (CLSI) to a multicenter study to determine the antifungal susceptibility of bloodstream infection (BSI) isolates of Candida species in Korea, and determined the relationship between the frequency of antifungal-resistant Candida BSI isolates and antifungal use at hospitals. Four hundred and fifty BSI isolates of Candida species were collected over a 1-year period in 2011 from nine hospitals. The susceptibilities of the isolates to four antifungal agents were determined using the CLSI M27 broth microdilution method. By applying the species-specific CBPs, non-susceptibility to fluconazole was found in 16.4% (70/428) of isolates, comprising 2.6% resistant and 13.8% susceptible-dose dependent isolates. However, non-susceptibility to voriconazole, caspofungin, or micafungin was found in 0% (0/370), 0% (0/437), or 0.5% (2/437) of the Candida BSI isolates, respectively. Of the 450 isolates, 72 (16.0%) showed decreased susceptibility to fluconazole [minimum inhibitory concentration (MIC) ≥4 μg/ml]. The total usage of systemic antifungals varied considerably among the hospitals, ranging from 190.0 to 7.7 defined daily dose per 1,000 patient days, and fluconazole was the most commonly prescribed agent (46.3%). By Spearman’s correlation analysis, fluconazole usage did not show a significant correlation with the percentage of fluconazole resistant isolates at hospitals. However, fluconazole usage was significantly correlated with the percentage of fluconazole non-susceptible isolates (r = 0.733; P = 0.025) or the percentage of isolates with decreased susceptibility to fluconazole (MIC ≥4 μg/ml) (r = 0.700; P = 0.036) at hospitals. Our work represents the first South Korean multicenter study demonstrating an association between antifungal use and antifungal resistance among BSI isolates of Candida at hospitals using the new CBPs of the CLSI. PMID:25706866

  2. Antifungal Susceptibility Profiles of Bloodstream Yeast Isolates by Sensititre YeastOne over Nine Years at a Large Italian Teaching Hospital

    PubMed Central

    Posteraro, Brunella; Spanu, Teresa; Fiori, Barbara; De Maio, Flavio; De Carolis, Elena; Giaquinto, Alessia; Prete, Valentina; De Angelis, Giulia; Torelli, Riccardo; D'Inzeo, Tiziana; Vella, Antonietta; De Luca, Alessio; Tumbarello, Mario; Ricciardi, Walter

    2015-01-01

    Sensititre YeastOne (SYO) is an affordable alternative to the Clinical and Laboratory Standards Institute (CLSI) reference method for antifungal susceptibility testing. In this study, the MICs of yeast isolates from 1,214 bloodstream infection episodes, generated by SYO during hospital laboratory activity (January 2005 to December 2013), were reanalyzed using current CLSI clinical breakpoints/epidemiological cutoff values to assign susceptibility (or the wild-type [WT] phenotype) to systemic antifungal agents. Excluding Candida albicans (57.4% of all isolates [n = 1,250]), the most predominant species were Candida parapsilosis complex (20.9%), Candida tropicalis (8.2%), Candida glabrata (6.4%), Candida guilliermondii (1.6%), and Candida krusei (1.3%). Among the non-Candida species (1.9%), 7 were Cryptococcus neoformans and 17 were other species, mainly Rhodotorula species. Over 97% of Candida isolates were susceptible (WT phenotype) to amphotericin B and flucytosine. Rates of susceptibility (WT phenotype) to fluconazole, itraconazole, and voriconazole were 98.7% in C. albicans, 92.3% in the C. parapsilosis complex, 96.1% in C. tropicalis, 92.5% in C. glabrata, 100% in C. guilliermondii, and 100% (excluding fluconazole) in C. krusei. The fluconazole-resistant isolates consisted of 6 C. parapsilosis complex isolates, 3 C. glabrata isolates, 2 C. albicans isolates, 2 C. tropicalis isolates, and 1 Candida lusitaniae isolate. Of the non-Candida isolates, 2 C. neoformans isolates had the non-WT phenotype for susceptibility to fluconazole, whereas Rhodotorula isolates had elevated azole MICs. Overall, 99.7% to 99.8% of Candida isolates were susceptible (WT phenotype) to echinocandins, but 3 isolates were nonsusceptible (either intermediate or resistant) to caspofungin (C. albicans, C. guilliermondii, and C. krusei), anidulafungin (C. albicans and C. guilliermondii), and micafungin (C. albicans). However, when the intrinsically resistant non-Candida isolates were included

  3. In Vitro Screening of 10 Edible Thai Plants for Potential Antifungal Properties

    PubMed Central

    Luplertlop, Natthanej

    2014-01-01

    Growing rates of fungal infections and increasing resistance against standard antifungal drugs can cause serious health problems. There is, therefore, increasing interest in the potential use of medicinal plants as novel antifungal agents. This study investigates the antifungal properties of crude plant extracts from ten medicinal plant species. Crude samples were extracted using the hot water extraction process. The minimum inhibitory concentrations (MIC) and diameter zone of inhibition were determined in each extract against ten fungal strains, and fluconazole was used as a positive control. The cytotoxicity of crude extracts on in vitro human skin fibroblast (HSF) cell models was determined by MTT assay. Of the ten crude extracts, Psidium guajava L. exhibited the highest antifungal activity, diameter zone of inhibition, and percentage HSF cell viability. Although all extracts exhibited antifungal activity, Psidium guajava L. had the greatest potential for developing antifungal treatments. PMID:24516502

  4. Diversity and antifungal susceptibility of Norwegian Candida glabrata clinical isolates

    PubMed Central

    Andersen, Kari-Mette; Kristoffersen, Anne Karin; Ingebretsen, André; Vikholt, Katharina Johnsen; Örtengren, Ulf Thore; Olsen, Ingar; Enersen, Morten; Gaustad, Peter

    2016-01-01

    Background Increasing numbers of immunocompromised patients have resulted in greater incidence of invasive fungal infections with high mortality. Candida albicans infections dominate, but during the last decade, Candida glabrata has become the second highest cause of candidemia in the United States and Northern Europe. Reliable and early diagnosis, together with appropriate choice of antifungal treatment, is needed to combat these challenging infections. Objectives To confirm the identity of 183 Candida glabrata isolates from different human body sites using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and VITEK®2, and to analyze isolate protein profiles and antifungal susceptibility. The minimum inhibitory concentration (MIC) of seven antifungal drugs was determined for the isolates to elucidate susceptibility. Design A total of 183 C. glabrata isolates obtained between 2002 and 2012 from Norwegian health-care units were analyzed. For species verification and differentiation, biochemical characterization (VITEK®2) and mass spectrometry (MALDI–TOF) were used. MIC determination for seven antifungal drugs was undertaken using E-tests®. Results Using VITEK®2, 92.9% of isolates were identified as C. glabrata, while all isolates (100%) were identified as C. glabrata using MALDI-TOF. Variation in protein spectra occurred for all identified C. glabrata isolates. The majority of isolates had low MICs to amphotericin B (≤1 mg/L for 99.5%) and anidulafungin (≤0.06 mg/L for 98.9%). For fluconazole, 18% of isolates had MICs >32 mg/L and 82% had MICs in the range ≥0.016 mg/L to ≤32 mg/L. Conclusions Protein profiles and antifungal susceptibility characteristics of the C. glabrata isolates were diverse. Clustering of protein profiles indicated that many azole resistant isolates were closely related. In most cases, isolates had highest susceptibility to amphotericin B and anidulafungin. The results confirmed previous observations of high

  5. Topical antifungals for seborrhoeic dermatitis

    PubMed Central

    Okokon, Enembe O; Verbeek, Jos H; Ruotsalainen, Jani H; Ojo, Olumuyiwa A; Bakhoya, Victor Nyange

    2015-01-01

    Background Seborrhoeic dermatitis is a chronic inflammatory skin condition that is distributed worldwide. It commonly affects the scalp, face and flexures of the body. Treatment options include antifungal drugs, steroids, calcineurin inhibitors, keratolytic agents and phototherapy. Objectives To assess the effects of antifungal agents for seborrhoeic dermatitis of the face and scalp in adolescents and adults. A secondary objective is to assess whether the same interventions are effective in the management of seborrhoeic dermatitis in patients with HIV/AIDS. Search methods We searched the following databases up to December 2014: the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 11), MEDLINE (from 1946), EMBASE (from 1974) and Latin American Caribbean Health Sciences Literature (LILACS) (from 1982). We also searched trials registries and checked the bibliographies of published studies for further trials. Selection criteria Randomised controlled trials of topical antifungals used for treatment of seborrhoeic dermatitis in adolescents and adults, with primary outcome measures of complete clearance of symptoms and improved quality of life. Data collection and analysis Review author pairs independently assessed eligibility for inclusion, extracted study data and assessed risk of bias of included studies. We performed fixed-effect meta-analysis for studies with low statistical heterogeneity and used a random-effects model when heterogeneity was high. Main results We included 51 studies with 9052 participants. Of these, 45 trials assessed treatment outcomes at five weeks or less after commencement of treatment, and six trials assessed outcomes over a longer time frame. We believe that 24 trials had some form of conflict of interest, such as funding by pharmaceutical companies. Among the included studies were 12 ketoconazole trials (N = 3253), 11 ciclopirox trials (N = 3029), two lithium trials (N = 141

  6. Survey of small antifungal peptides with chemotherapeutic potential.

    PubMed

    Desbois, Andrew P; Tschörner, David; Coote, Peter J

    2011-08-01

    Many cationic peptides with antimicrobial properties have been isolated from bacteria, fungi, plants, and animals. These peptides vary in molecular size, potency and spectra of activities. This report surveyed the literature to highlight the peptides that have antifungal activity and greatest potential for development as new therapeutic agents. Thus, to be included in the evaluation, each peptide had to fulfil the following criteria: (i) potent antifungal activity, (ii) no, or minimal, mammalian cell toxicity, (iii) of ≤25 amino acids in length, which minimises the costs of synthesis, reduces immunogenicity and enhances bioavailability and stability in vivo, (iv) minimal post-translational modifications (also reduces the production costs). The ~80 peptides that satisfied these criteria are discussed with respect to their structures, mechanisms of antimicrobial action and in vitro and in vivo toxicities. Certainly, some of these small peptides warrant further study and have potential for future exploitation as new antifungal agents. PMID:21470150

  7. Additive and synergistic antiandrogenic activities of mixtures of azol fungicides and vinclozolin

    SciTech Connect

    Christen, Verena; Crettaz, Pierre; Fent, Karl

    2014-09-15

    Objective: Many pesticides including pyrethroids and azole fungicides are suspected to have an endocrine disrupting property. At present, the joint activity of compound mixtures is only marginally known. Here we tested the hypothesis that the antiandrogenic activity of mixtures of azole fungicides can be predicted by the concentration addition (CA) model. Methods: The antiandrogenic activity was assessed in MDA-kb2 cells. Following assessing single compounds activities mixtures of azole fungicides and vinclozolin were investigated. Interactions were analyzed by direct comparison between experimental and estimated dose–response curves assuming CA, followed by an analysis by the isobole method and the toxic unit approach. Results: The antiandrogenic activity of pyrethroids deltamethrin, cypermethrin, fenvalerate and permethrin was weak, while the azole fungicides tebuconazole, propiconazole, epoxiconazole, econazole and vinclozolin exhibited strong antiandrogenic activity. Ten binary and one ternary mixture combinations of five antiandrogenic fungicides were assessed at equi-effective concentrations of EC{sub 25} and EC{sub 50}. Isoboles indicated that about 50% of the binary mixtures were additive and 50% synergistic. Synergism was even more frequently indicated by the toxic unit approach. Conclusion: Our data lead to the conclusion that interactions in mixtures follow the CA model. However, a surprisingly high percentage of synergistic interactions occurred. Therefore, the mixture activity of antiandrogenic azole fungicides is at least additive. Practice: Mixtures should also be considered for additive antiandrogenic activity in hazard and risk assessment. Implications: Our evaluation provides an appropriate “proof of concept”, but whether it equally translates to in vivo effects should further be investigated. - Highlights: • Humans are exposed to pesticide mixtures such as pyrethroids and azole fungicides. • We assessed the antiandrogenicity of

  8. Regio- and Enantioselective Synthesis of Azole Hemiaminal Esters by Lewis Base Catalyzed Dynamic Kinetic Resolution.

    PubMed

    Piotrowski, David W; Kamlet, Adam S; Dechert-Schmitt, Anne-Marie R; Yan, Jiangli; Brandt, Thomas A; Xiao, Jun; Wei, Liuqing; Barrila, Mark T

    2016-04-13

    We report a modular three-component dynamic kinetic resolution (DKR) that affords enantiomerically enriched hemiaminal esters derived from azoles and aldehydes. The novel and scalable reaction can be used to synthesize valuable substituted azoles in a regioselective manner by capping (e.g., acylation) of the equilibrating azole-aldehyde adduct. With the use of a prolinol-derived DMAP catalyst as the chiral Lewis base, the products can be obtained in high chemical yield and with high enantiomeric excess. The DKR was performed on a multikilogram scale to produce a tetrazole prodrug fragment for a leading clinical candidate that posed formidable synthesis challenges. PMID:27003237

  9. EUCAST breakpoints for antifungals.

    PubMed

    Rodríguez-Tudela, Juan L; Arendrup, Maiken C; Cuenca-Estrella, Manuel; Donnelly, J Peter; Lass-Flörl, Cornelia

    2010-03-01

    Susceptibility testing of fungi and development of interpretative breakpoints has become increasingly important due to the growing incidence of invasive fungal infections, the number and classes of antifungals, and the emerging reports of acquired resistance. The subcommittee on antifungal susceptibility testing of the European Committee on Antibiotic Susceptibility Testing (EUCAST) has developed standards for susceptibility testing of fermentative yeasts and molds as well as proposing breakpoints for fluconazole and voriconazole against Candida. The aim of this work is to describe the EUCAST process of setting breakpoints for antifungals. Five aspects are evaluated during the process of developing breakpoints: 1) the most common dosage used in each European country, 2) the definition of the wild-type population for each target microorganism at the species level and the determination of epidemiological cutoffs, 3) the drug's pharmacokinetics and 4) pharmacodynamics, including Monte Carlo simulations, and 5) the correlation of MICs with clinical outcome of patients treated with the compound. When insufficient data are available (e.g., due to lack of information on the clinical outcome of infections caused by isolates with an elevated MIC), epidemiological cutoff values, rather than breakpoints, are recommended until the necessary information becomes available. PMID:20369073

  10. Design, synthesis, and structure-activity relationship studies of novel thienopyrrolidone derivatives with strong antifungal activity against Aspergillus fumigates.

    PubMed

    Cao, Xufeng; Xu, Yuanyuan; Cao, Yongbing; Wang, Ruilian; Zhou, Ran; Chu, Wenjing; Yang, Yushe

    2015-09-18

    In order to further enhance the anti-Aspergillus efficacy of our previously discovered antifungal lead compounds (I), two series of novel azoles featuring thieno[2,3-c]pyrrolidone and thieno[3,2-c]pyrrolidone nuclei were designed and evaluated for their in vitro activity on the basis of the binding mode of albaconazole using molecular docking, along with SARs of antifungal triazoles. Most of target compounds exhibited excellent activity against Candida and Cryptococcus spp., with MIC values in the range of 0.0625 μg/ml to 0.0156 μg/ml. The thieno[3,2-c]pyrrolidone unit was more suited for improving activity against Aspergillus spp. The most potent compound, 18a, was selected for further development due to its significant in vitro activity against Aspergillus spp. (MIC = 0.25 μg/ml), as well as its high metabolic stability in human liver microsomes. PMID:26310892

  11. Effect of preharvest anti-fungal compounds on Aspergillus steynii and A. carbonarius under fluctuating and extreme environmental conditions.

    PubMed

    García-Cela, E; Gil-Serna, J; Marín, S; Acevedo, H; Patiño, B; Ramos, A J

    2012-10-01

    Ochratoxin A (OTA) has been found in pre-harvest and freshly harvested wheat. Spanish climatic conditions point to Aspergillus species as probably responsible for this OTA. In this study the effectiveness of 5 non-specific antifungal chemicals used on wheat fields (25.9% tebuconazole+60.0% N,N-capramide dimethyl; 12.70% tebuconazole+12.7% prothioconazole+59.5% N,N-amide dimethyldecane; 12.5% epoxiconazole; 12.5% tetraconazole; and 70% thiophanate methyl) and an extract from Equisetum arvense were investigated in vitro on wheat by recording growth (colony size, fungal growth and DNA concentration) and OTA production of two ochratoxigenic isolates of Aspergillus carbonarius and three of A. steynii, simulating current and extreme climatic conditions. Inoculated wheat was incubated under two alternating temperature cycles (20/30°C and 25/35°C) with photoperiod (14/10h lightness/darkness), and two moisture levels (40 and 25%). The Aspergillus species tested seemed to be able to persist in predicted future climatic conditions, in particular, A. steynii, a high OTA producer. Azoles were effective in controlling the growth of A. carbonarius and A. steynii, and this effectiveness may not be compromised by the increase in temperature and decrease of humidity. However, azoles are not useful for the prevention of OTA accumulation, which could be only reduced in A. carbonarius under non-extreme conditions. Although some adjustment will probably be required, further studies should be conducted in the field, since the antifungals used in this study are applied at flowering and not directly on the grain. Moreover, timing of antifungal application may need to be optimized. Finally, Equisetum extract showed promising results as an antifungal, however further work to adjust the applied concentrations is required. PMID:22947301

  12. Update from the Laboratory: Clinical Identification and Susceptibility Testing of Fungi and Trends in Antifungal Resistance.

    PubMed

    Albataineh, Mohammad T; Sutton, Deanna A; Fothergill, Annette W; Wiederhold, Nathan P

    2016-03-01

    Despite the availability of new diagnostic assays and broad-spectrum antifungal agents, invasive fungal infections remain a significant challenge to clinicians and are associated with marked morbidity and mortality. In addition, the number of etiologic agents of invasive mycoses has increased accompanied by an expansion in the immunocompromised patient populations, and the use of molecular tools for fungal identification and characterization has resulted in the discovery of several cryptic species. This article reviews various methods used to identify fungi and perform antifungal susceptibility testing in the clinical laboratory. Recent developments in antifungal resistance are also discussed. PMID:26739605

  13. Antifungal ellagitannin isolated from Euphorbia antisyphilitica Zucc

    PubMed Central

    Ascacio-Valdés, Juan; Burboa, Edgardo; Aguilera-Carbo, Antonio F; Aparicio, Mario; Pérez-Schmidt, Ramón; Rodríguez, Raúl; Aguilar, Cristóbal N

    2013-01-01

    Objective To study antifungal activity of a new ellagitannin isolated from the plant residues of Euphorbia antisyphilitica (E. antisyphilitica) Zucc in the wax extraction process. Methods An extract was prepared from dehydrated and pulverized residues and fractionated by liquid chromatography on Amberilte XAD-16, until obtained an ellagitannin-rich ethanolic fraction which was treated by rotaevaporation to recover the ellagitannin as fine powder. An aqueous solution was prepared and treated through ionic exchange liquid chromatography (Q XL) and gel permeation chromatography (G 25). The ellagitannin-rich fraction was thermogravimetrically evaluated (TGA and DTA) to test the thermo-stability of ellagic acid (monomeric unit). Then ellagitannin powder was analyzed by infrared spectrospcopy to determinate the functional groups and, also mass spectroscopy was used to determine the molecular ion. Results The principal functional groups of ellagitannin were determined, the molecular weight was 860.7 g/mol; and an effective antifungal activity against phytopathogenic fungi was demonstrated. Conclusions It can be concluded that the new ellagitannin (860.7 g/mol) isolated from E. antisyphilitica Zucc is an effective antifungal agent against Alternaria alternata, Fusarium oxyzporum, Colletotrichum gloeosporoides and Rhizoctnia solani. PMID:23570015

  14. Chemical modification of antifungal polyene macrolide antibiotics

    NASA Astrophysics Data System (ADS)

    Solovieva, S. E.; Olsufyeva, E. N.; Preobrazhenskaya, M. N.

    2011-02-01

    The review summarizes advances in the methods for the synthesis of polyene antibiotics (amphotericin B, partricin A, etc.) and investigations of the structure-activity relationship made in the last 15 years. State-of-the-art approaches based on the combination of the chemical synthesis and genetic engineering are considered. Emphasis is given to the design of semisynthetic antifungal agents against chemotherapy-resistant pathogens having the highest therapeutic indices. Recent results of research on the mechanisms of action of polyenes are outlined.

  15. A study to evaluate the price control of antifungal medicines and its practical applicability

    PubMed Central

    Sil, Amrita; Das, Nilay Kanti; Ghosh, Pramit; Datta, Pijush Kanti; Islam, Chowdhury Nazrul; Tripathi, Santanu Kumar

    2012-01-01

    Background: Superficial fungal infections are common and treatment imposes economic burden on the patients. Government of India had introduced price control over griseofulvin and tolnaftate in 1995; however, this measure can only benefit the needy if the policy is harmonized with the health-care service provider, that is, dermatologists. The aim of this study was to evaluate the existing Government mechanisms over price control of antifungal medications and its reach to the people-in-need. Materials and Methods: A questionnaire-based, cross-sectional study was carried out over a period of 6 months. Questionnaire was mailed to members of a state branch of Indian Association of Dermatologists, Venereologists, and Leprologists. Responses reaching investigators within 2 months from the date of mailing were finally analyzed. Results: Among 93 (41.33%) respondents, only 6 (6.5%) were aware of existing price control over griseofulvin but none about tolnaftate. Thirty-nine (41.9%) respondents were in favor of introducing price control on terbinafine and 42 (45.2%) for itraconazole. The topically preferred antifungals were primarily azoles and terbinafine, while among systemic antifungals, dermatologists mostly preferred fluconazole and terbinafine. The choice of antifungals by the dermatologists matched with the evidence-based dermatology data. Conclusion: Currently, price-controlled antifungal drugs are less commonly used by practitioners. Although the dermatologists favor price control, the initiative undertaken by the Government has not reached them. This shows the need to bridge the gap between policy makers and health-care service providers to help the ailing population. PMID:23248398

  16. Candida tropicalis from veterinary and human sources shows similar in vitro hemolytic activity, antifungal biofilm susceptibility and pathogenesis against Caenorhabditis elegans.

    PubMed

    Brilhante, Raimunda Sâmia Nogueira; Oliveira, Jonathas Sales de; Evangelista, Antônio José de Jesus; Serpa, Rosana; Silva, Aline Lobão da; Aguiar, Felipe Rodrigues Magalhães de; Pereira, Vandbergue Santos; Castelo-Branco, Débora de Souza Collares Maia; Pereira-Neto, Waldemiro Aquino; Cordeiro, Rossana de Aguiar; Sidrim, José Júlio Costa; Rocha, Marcos Fábio Gadelha

    2016-08-30

    The aim of this study was to evaluate the in vitro hemolytic activity and biofilm antifungal susceptibility of veterinary and human Candida tropicalis strains, as well as their pathogenesis against Caenorhabditis elegans. Twenty veterinary isolates and 20 human clinical isolates of C. tropicalis were used. The strains were evaluated for their hemolytic activity and biofilm production. Biofilm susceptibility to itraconazole, fluconazole, voriconazole, amphotericin B and caspofungin was assessed using broth microdilution assay. The in vivo evaluation of strain pathogenicity was investigated using the nematode C. elegans. Hemolytic factor was observed in 95% of the strains and 97.5% of the isolates showed ability to form biofilm. Caspofungin and amphotericin B showed better results than azole antifungals against mature biofilms. Paradoxical effect on mature biofilm metabolic activity was observed at elevated concentrations of caspofungin (8-64μg/mL). Azole antifungals were not able to inhibit mature C. tropicalis biofilms, even at the higher tested concentrations. High mortality rates of C. elegans were observed when the worms were exposed to with C. tropicalis strains, reaching up to 96%, 96h after exposure of the worms to C. tropicalis strains. These results reinforce the high pathogenicity of C. tropicalis from veterinary and human sources and show the effectiveness of caspofungin and amphotericin B against mature biofilms of this species. PMID:27527785

  17. Antifungal activity of Brevibacillus laterosporus JX-5 and characterization of its antifungal components.

    PubMed

    Jiang, Hongxia; Wang, Xiaohui; Xiao, Chengze; Wang, Weiyan; Zhao, Xu; Sui, Junkang; Sa, Rongbo; Guo, Tai L; Liu, Xunli

    2015-10-01

    The establishment of safe and effective methods for controlling fungal disease is an urgent issue in agriculture and forestry. Microbiological control of plant disease is expected to achieve better results than use of chemically derived fungicides. This study aimed to establish Brevibacillus laterosporus JX-5 as a potential microbiological control agent of poplar canker. The bacterium was isolated from the poplar rhizosphere and demonstrated significant growth inhibition of several pathogenic fungi in vitro. The antifungal components of Br. laterosporus JX-5 were isolated and identified. The fermentation broth of Br. laterosporus JX-5 and its main antifungal component, designated as component B, reduced Botryosphaeria dothidea associated canker of the excised poplar branch by 70 and 90%, respectively. Component B is considerably heat-stable, adaptable to a broad pH range, and UV-resistant. It could inhibit Bo. dothidea by permeating the fungal membrane, fracturing the nuclei, damaging the cell wall, and eventually killing the pathogenic fungus. The antifungal activity exhibited by Br. laterosporus JX-5 and its bioactive metabolic products indicate its feasibility as a potential biocontrol agent for plant diseases. PMID:26265360

  18. [Azole resistance in Aspergillus fumigatus in the Netherlands--increase due to environmental fungicides?].

    PubMed

    Verweij, Paul E; van de Sande-Bruisma, Nienke; Kema, Gert H J; Melchers, Willem J G

    2012-01-01

    The mould Aspergillus fumigatus may develop mechanisms that confer resistance to itraconazole, voriconazole and posaconazole. In the Netherlands a dominant resistance mechanism referred to as TR/L98H is found. In A. fumigatus isolates recovered from clinical samples in Dutch hospitals the prevalence of azole resistance varied between 0.8% and 9.4%. The TR/L98H resistance mechanism probably develops in our environment, as azoles are frequently used for crop protection and material preservation. It is likely that breathing in the resistant spores of these strains from the environment leads to clinical infection. More research is needed to understand the environmental route of resistance development and to enable effective measures to prevent this occurring. Azole resistance is associated with treatment failure. Of 8 patients with azole-resistant invasive aspergillosis 7 died within 12 weeks of diagnosis. Alternative treatment regimens might include lipid-formulation of amphotericin B or a combination of voriconazole and an echinocandin, but there is little data available to support these choices. Physicians who treat patients with Aspergillus diseases should be aware of the possibility of azole resistance, also in azole-naïve patients. PMID:22748367

  19. Antifungal Drugs for Onychomycosis: Efficacy, Safety, and Mechanisms of Action.

    PubMed

    Rosen, Theodore; Stein Gold, Linda F

    2016-03-01

    In 1996, oral terbinafine joined itraconazole and fluconazole on the short list of systemic medications that could be used to treat onychomycosis (although fluconazole was not approved for this indication by the US Food and Drug Administration [FDA], it was commonly used for this purpose). In 1999, ciclopirox was the first topical treatment to be FDA approved. The addition of the topical antifungal agents efinaconazole and tavaborole in 2014 expanded the roster of medications available to more effectively manage onychomycosis in a wide range of patients, including those for whom comorbid conditions, concomitant medications, or patient preference limited the use of systemic antifungals. PMID:27074700

  20. Design of new antifungal agents: synthesis and evaluation of 1-[(1H-indol-5-ylmethyl)amino]-2-phenyl-3-(1H-1,2,4-triazol-1-yl)propan-2-ols.

    PubMed

    Guillon, Rémi; Giraud, Francis; Logé, Cédric; Le Borgne, Marc; Picot, Carine; Pagniez, Fabrice; Le Pape, Patrice

    2009-10-15

    We previously reported on the design and synthesis of 1-[((hetero)aryl- or piperidinylmethyl)amino]-2-phenyl-3-(1H-1,2,4-triazol-1-yl)propan-2-ols showing various degrees of antifungal activity against Candida albicans and Aspergillus fumigatus strains. Now we have identified a series of 1-[(1H-indol-5-ylmethyl)amino] derivatives which exhibited potent MICs (<65 ng mL(-1)) against C. albicans strain. The synthesis and SAR behind the indole scaffold will be discussed. PMID:19762235

  1. nor-Mevaldic acid surrogates as selective antifungal agent leads against Botrytis cinerea. Enantioselective preparation of 4-hydroxy-6-(1-phenylethoxy)tetrahydro-2H-pyran-2-one.

    PubMed

    Botubol-Ares, José Manuel; Durán-Peña, María Jesús; Hernández-Galán, Rosario; Collado, Isidro G; Harwood, Laurence M; Macías-Sánchez, Antonio J

    2015-07-01

    Solvent-free desymmetrisation of meso-dialdehyde 1 with chiral 1-phenylethan-1-ol, led to preparation of 4-silyloxy-6-alkyloxytetrahydro-2H-pyran-2-one (+)-3a with a 96:4 dr Deprotected lactone (+)-19a and the related racemic lactones 16a-18a present a lactone moiety resembling the natural substrate of HMG-CoA reductase and their antifungal properties have been evaluated against the phytopathogenic fungi Botrytis cinerea and Colletotrichum gloeosporioides. These compounds were selectively active against B. cinerea, while inactive against C. gloeosporioides. PMID:25971873

  2. Genotyping of Fusarium Isolates from Onychomycoses in Colombia: Detection of Two New Species Within the Fusarium solani Species Complex and In Vitro Antifungal Susceptibility Testing.

    PubMed

    Guevara-Suarez, Marcela; Cano-Lira, José Francisco; Cepero de García, María Caridad; Sopo, Leticia; De Bedout, Catalina; Cano, Luz Elena; García, Ana María; Motta, Adriana; Amézquita, Adolfo; Cárdenas, Martha; Espinel-Ingroff, Ana; Guarro, Josep; Restrepo, Silvia; Celis, Adriana

    2016-04-01

    Fusariosis have been increasing in Colombia in recent years, but its epidemiology is poorly known. We have morphologically and molecularly characterized 89 isolates of Fusarium obtained between 2010 and 2012 in the cities of Bogotá and Medellín. Using a multi-locus sequence analysis of rDNA internal transcribed spacer, a fragment of the translation elongation factor 1-alpha (Tef-1α) and of the RNA-dependent polymerase subunit II (Rpb2) genes, we identified the phylogenetic species and circulating haplotypes. Since most of the isolates studied were from onychomycoses (nearly 90 %), we carried out an epidemiological study to determine the risk factors associated with such infections. Five phylogenetic species of the Fusarium solani species complex (FSSC), i.e., F. falciforme, F. keratoplasticum, F. lichenicola, F. petroliphilum, and FSSC 6 as well as two of the Fusarium oxysporum species complex (FOSC), i.e., FOSC 3 and FOSC 4, were identified. The most prevalent species were FOSC 3 (38.2 %) followed by F. keratoplasticum (33.7 %). In addition, our isolates were distributed into 23 haplotypes (14 into FOSC and nine into FSSC). Two of the FSSC phylogenetic species and two haplotypes of FSSC were not described before. Our results demonstrate that recipients of pedicure treatments have a lower probability of acquiring onychomycosis than those not receiving such treatments. The antifungal susceptibility of all the isolates to five clinically available agents showed that amphotericin B was the most active drug, while the azoles exhibited lower in vitro activity. PMID:26943726

  3. Genotypic evolution of azole resistance mechanisms in sequential Candida albicans isolates.

    PubMed

    Coste, Alix; Selmecki, Anna; Forche, Anja; Diogo, Dorothée; Bougnoux, Marie-Elisabeth; d'Enfert, Christophe; Berman, Judith; Sanglard, Dominique

    2007-10-01

    TAC1 (for transcriptional activator of CDR genes) is critical for the upregulation of the ABC transporters CDR1 and CDR2, which mediate azole resistance in Candida albicans. While a wild-type TAC1 allele drives high expression of CDR1/2 in response to inducers, we showed previously that TAC1 can be hyperactive by a gain-of-function (GOF) point mutation responsible for constitutive high expression of CDR1/2. High azole resistance levels are achieved when C. albicans carries hyperactive alleles only as a consequence of loss of heterozygosity (LOH) at the TAC1 locus on chromosome 5 (Chr 5), which is linked to the mating-type-like (MTL) locus. Both are located on the Chr 5 left arm along with ERG11 (target of azoles). In this work, five groups of related isolates containing azole-susceptible and -resistant strains were analyzed for the TAC1 and ERG11 alleles and for Chr 5 alterations. While recovered ERG11 alleles contained known mutations, 17 new TAC1 alleles were isolated, including 7 hyperactive alleles with five separate new GOF mutations. Single-nucleotide-polymorphism analysis of Chr 5 revealed that azole-resistant strains acquired TAC1 hyperactive alleles and, in most cases, ERG11 mutant alleles by LOH events not systematically including the MTL locus. TAC1 LOH resulted from mitotic recombination of the left arm of Chr 5, gene conversion within the TAC1 locus, or the loss and reduplication of the entire Chr 5. In one case, two independent TAC1 hyperactive alleles were acquired. Comparative genome hybridization and karyotype analysis revealed the presence of isochromosome 5L [i(5L)] in two azole-resistant strains. i(5L) leads to increased copy numbers of azole resistance genes present on the left arm of Chr 5, among them TAC1 and ERG11. Our work shows that azole resistance was due not only to the presence of specific mutations in azole resistance genes (at least ERG11 and TAC1) but also to their increase in copy number by LOH and to the addition of extra Chr 5

  4. Epidemiology, risk factor, species distribution, antifungal resistance and outcome of Candidemia at a single French hospital: a 7-year study.

    PubMed

    Tadec, Laurent; Talarmin, Jean-Philippe; Gastinne, Thomas; Bretonnière, Cédric; Miegeville, Michel; Le Pape, Patrice; Morio, Florent

    2016-05-01

    Candidemia remains a major cause of disease worldwide and is associated with a high mortality rate. We conducted a retrospective study of candidemia at Nantes Hospital, France, between 2004 and 2010. A total of 191 episodes (n = 188 patients) were reviewed. Incidence, demographics, risk factors, antifungal management, species identification, in vitro susceptibility and 12 weeks survival were analysed. Global incidence of candidemia was 0.37‰ admissions. Higher incidences were observed in haematology (6.65‰) and intensive care units (2‰). Central venous catheter and antibiotic exposure were the most frequent risk factors (77% and 76% respectively). Candida albicans was the predominant species (51.8%) followed by C. parapsilosis (14.5%), C. glabrata (9.8%), C. tropicalis (9.8%) and C. krusei (4.1%). However, species distribution differed significantly between medical units with frequency of C. tropicalis being higher in haematology compared to other medical units. Fluconazole and caspofungin were the main antifungals given as first-line therapy. Although not significant, 12 weeks mortality rate was 30.9%, being higher for C. tropicalis (44.4%) than for C. parapsilosis (16%). Acquired azole or echinocandin resistance was noted in some isolates, underlining the need for systematic antifungal susceptibility testing in patients with candidemia. These epidemiological findings will be of interest for antifungal stewardship at our hospital. PMID:26806101

  5. [Treatment of dermatoses : Significance and use of glucocorticoids in fixed combination with antifungals].

    PubMed

    Mayser, P

    2016-09-01

    Treating eczema with fungal and/or bacterial superinfections or superficial mycoses are a common problem in daily practice. A fungal superinfection as a consequence of a diminished skin barrier might complicate the course of eczema. In addition, in an inflammatory superficial mycotic infection a delayed-type hypersensitivity reaction may result in healing of the lesion, but might also be responsible for irreversible damage of epidermal structures. An example is permanent hair loss by scarring alopecia in the context of inflammatory tinea capitis. In both cases, combination of an antifungal and a glucocorticoid is appropriate in therapy, preferentially in topical application. The use of azole antimycotics is especially helpful, as they are also effective against gram-positive bacteria. PMID:27411685

  6. Antifungal activity of multifunctional Fe 3O 4-Ag nanocolloids

    NASA Astrophysics Data System (ADS)

    Chudasama, Bhupendra; Vala, Anjana K.; Andhariya, Nidhi; Upadhyay, R. V.; Mehta, R. V.

    2011-05-01

    In recent years, rapid increase has been observed in the population of microbes that are resistant to conventionally used antibiotics. Antifungal drug therapy is no exception and now resistance to many of the antifungal agents in use has emerged. Therefore, there is an inevitable and urgent medical need for antibiotics with novel antimicrobial mechanisms. Aspergillus glaucus is the potential cause of fatal brain infections and hypersensitivity pneumonitis in immunocompromised patients and leads to death despite aggressive multidrug antifungal therapy. In the present article, we describe the antifungal activity of multifunctional core-shell Fe 3O 4-Ag nanocolloids against A. glaucus isolates. Controlled experiments are also carried out with Ag nanocolloids in order to understand the role of core (Fe 3O 4) in the antifungal action. The minimum inhibitory concentration (MIC) of nanocolloids is determined by the micro-dilution method. MIC of A. glaucus is 2000 μg/mL. The result is quite promising and requires further investigations in order to develop a treatment methodology against this death causing fungus in immunocompromised patients.

  7. In Vitro and In Vivo Activity of a Novel Antifungal Small Molecule against Candida Infections

    PubMed Central

    Yuen, Kwok Yong; Wang, Yu; Yang, Dan; Samaranayake, Lakshman Perera

    2014-01-01

    Candida is the most common fungal pathogen of humans worldwide and has become a major clinical problem because of the growing number of immunocompromised patients, who are susceptible to infection. Moreover, the number of available antifungals is limited, and antifungal-resistant Candida strains are emerging. New and effective antifungals are therefore urgently needed. Here, we discovered a small molecule with activity against Candida spp. both in vitro and in vivo. We screened a library of 50,240 small molecules for inhibitors of yeast-to-hypha transition, a major virulence attribute of Candida albicans. This screening identified 20 active compounds. Further examination of the in vitro antifungal and anti-biofilm properties of these compounds, using a range of Candida spp., led to the discovery of SM21, a highly potent antifungal molecule (minimum inhibitory concentration (MIC) 0.2 – 1.6 µg/ml). In vitro, SM21 was toxic to fungi but not to various human cell lines or bacterial species and was active against Candida isolates that are resistant to existing antifungal agents. Moreover, SM21 was relatively more effective against biofilms of Candida spp. than the current antifungal agents. In vivo, SM21 prevented the death of mice in a systemic candidiasis model and was also more effective than the common antifungal nystatin at reducing the extent of tongue lesions in a mouse model of oral candidiasis. Propidium iodide uptake assay showed that SM21 affected the integrity of the cell membrane. Taken together, our results indicate that SM21 has the potential to be developed as a novel antifungal agent for clinical use. PMID:24465737

  8. Metal-Based Antibacterial and Antifungal Agents: Synthesis, Characterization, and In Vitro Biological Evaluation of Co(II), Cu(II), Ni(II), and Zn(II) Complexes With Amino Acid-Derived Compounds.

    PubMed

    Chohan, Zahid H; Arif, M; Akhtar, Muhammad A; Supuran, Claudiu T

    2006-01-01

    A series of antibacterial and antifungal amino acid-derived compounds and their cobalt(II), copper(II), nickel(II), and zinc(II) metal complexes have been synthesized and characterized by their elemental analyses, molar conductances, magnetic moments, and IR, and electronic spectral measurements. Ligands (L(1))-(L(5)) were derived by condensation of beta-diketones with glycine, phenylalanine, valine, and histidine and act as bidentate towards metal ions (cobalt, copper, nickel, and zinc) via the azomethine-N and deprotonated-O of the respective amino acid. The stoichiometric reaction between the metal(II) ion and synthesized ligands in molar ratio of M : L (1 : 1) resulted in the formation of the metal complexes of type [M(L)(H(2)O)(4)]Cl (where M = Co(II), Cu(II), and Zn(II)) and of M : L (1 : 2) of type [M(L)(2)(H(2)O)(2)] (where M = Co(II), Cu(II), Ni(II), and Zn(II)). The magnetic moment data suggested for the complexes to have an octahedral geometry around the central metal atom. The electronic spectral data also supported the same octahedral geometry of the complexes. Elemental analyses and NMR spectral data of the ligands and their metal(II) complexes agree with their proposed structures. The synthesized ligands, along with their metal(II) complexes, were screened for their in vitro antibacterial activity against four Gram-negative (Escherichia coli, Shigella flexeneri, Pseudomonas aeruginosa, and Salmonella typhi) and two Gram-positive (Bacillus subtilis and Staphylococcus aureus) bacterial strains and for in vitro antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani, and Candida glaberata. The results of these studies show the metal(II) complexes to be more antibacterial/antifungal against one or more species as compared to the uncomplexed ligands. The brine shrimp bioassay was also carried out to study their in vitro cytotoxic properties. Five compounds, (3), (7), (10), (11), and (22

  9. Suppressive drug interactions between antifungals.

    PubMed

    de Vos, Marjon G J; Bollenbach, Tobias

    2014-04-24

    In this issue of Chemistry & Biology, Cokol and colleagues report a systematic study of drug interactions between antifungal compounds. Suppressive drug interactions occur more frequently than previously realized and come in different flavors with interesting implications. PMID:24766845

  10. Identification of Ebsulfur Analogues with Broad-Spectrum Antifungal Activity.

    PubMed

    Ngo, Huy X; Shrestha, Sanjib K; Garneau-Tsodikova, Sylvie

    2016-07-19

    Invasive fungal infections are on the rise due to an increased population of critically ill patients as a result of HIV infections, chemotherapies, and organ transplantations. Current antifungal drugs are helpful, but are insufficient in addressing the problem of drug-resistant fungal infections. Thus, there is a growing need for novel antimycotics that are safe and effective. The ebselen scaffold has been evaluated in clinical trials and has been shown to be safe in humans. This makes ebselen an attractive scaffold for facile translation from bench to bedside. We recently reported a library of ebselen-inspired ebsulfur analogues with antibacterial properties, but their antifungal activity has not been characterized. In this study, we repurposed ebselen, ebsulfur, and 32 additional ebsulfur analogues as antifungal agents by evaluating their antifungal activity against a panel of 13 clinically relevant fungal strains. The effect of induction of reactive oxygen species (ROS) by three of these compounds was evaluated. Their hemolytic and cytotoxicity activities were also determined using mouse erythrocytes and mammalian cells. The MIC values of these compounds were found to be in the range of 0.02-12.5 μg mL(-1) against the fungal strains tested. Notably, yeast cells treated with our compounds showed an accumulation of ROS, which may further contribute to the growth-inhibitory effect against fungi. This study provides new lead compounds for the development of antimycotic agents. PMID:27334363

  11. Azole susceptibility of Malassezia pachydermatis and Malassezia furfur and tentative epidemiological cut-off values.

    PubMed

    Cafarchia, Claudia; Iatta, Roberta; Immediato, Davide; Puttilli, Maria Rita; Otranto, Domenico

    2015-09-01

    This study aims to determine the minimal inhibitory concentration (MIC) distribution and the epidemiological cut-off values (ECVs) of Malassezia pachydermatis and Malassezia furfur isolates for fluconazole (FLZ), itraconazole (ITZ), posaconazole (POS), and voriconazole (VOR). A total of 62 M. pachydermatis strains from dogs with dermatitis and 78 M. furfur strains from humans with bloodstream infections (BSI) were tested by a modified broth microdilution Clinical and Laboratory Standards Institute (CLSI) method. ITZ and POS displayed lower MICs than VOR and FLZ, regardless of the Malassezia species. The MIC data for azoles of M. pachydermatis were four two-fold dilutions lower than those of M. furfur. Based on the ECVs, about 94% of Malassezia strains might be categorized within susceptible population for all azoles, except for FLZ, and azole cross-resistance was detected in association with FLZ in M. pachydermatis but not in M. furfur.The study proposes, for the first time, tentative azole ECVs for M. pachydermatis and M. furfur for monitoring the emergence of isolates with decreased susceptibilities and shows that the azole MIC distribution varied according to the Malassezia species tested, thus suggesting the usefulness of determining the susceptibility profile for effective treatment of each species. PMID:26162472

  12. Novel hybrids of fluconazole and furanones: design, synthesis and antifungal activity.

    PubMed

    Borate, Hanumant B; Sawargave, Sangmeshwer P; Chavan, Subhash P; Chandavarkar, Mohan A; Iyer, Ramki; Tawte, Amit; Rao, Deepali; Deore, Jaydeep V; Kudale, Ananada S; Mahajan, Pankaj S; Kangire, Gopinath S

    2011-08-15

    During our efforts to develop new antifungal agents, a number of hybrid molecules containing furanones and fluconazole pharmacophores were designed and synthesized. The new chemical entities thus synthesized were tested for their potential as antifungal agents against various fungal strains and it was observed that the compounds with general structure 7 were potent inhibitors of Candida albicans ATCC 24433, Candida glabrata ATCC 90030, Candida tropicalis ATCC 750 and Candida neoformans ATCC 34664 while the fluconazole analogues 12 exhibited antifungal activity against Candida albicans ATCC 24433 and Candida glabrata ATCC 90030. The structure-activity relationship for these compounds is discussed. The synthetic strategies used in the present work have potential to prepare a large number of compounds for further refinement of structures to obtain molecules suitable for development as antifungal drugs. PMID:21757344

  13. Comparison of the Sensititre YeastOne® dilution method with the Clinical Laboratory Standards Institute (CLSI) M27-A3 microbroth dilution reference method for determining MIC of eight antifungal agents on 102 yeast strains.

    PubMed

    Bertout, S; Dunyach, C; Drakulovski, P; Reynes, J; Mallié, M

    2011-02-01

    The Clinical Laboratory Standards Institute ([CLSI] formerly NCCLS) reference broth microdilution testing method (protocol M27-A3) was compared with a commercially available methods (Sensititre YeastOne(®)) by testing two quality control strains and 102 isolates of Candida sp. and Cryptococcus sp. against fluconazole, itraconazole, ketoconazole, posaconazole, voriconazole, flucytosin, amphotericin B and caspofungin. Minimal inhibitory concentrations (MIC) endpoints were determined after 24h of incubation for Sensititre YeastOne(®) and after 24 and 48 h for CLSI microdilution method. Essential agreements between methods vary from 70.6 to 92.2%. Categorical agreements vary from 94.1% for 5FC to 72.6% for AMB. Sensititre YeastOne(®) reading appears to be useful for avoiding very major errors and this confirms the interest of this method for evaluating new antifungals activity in vitro. PMID:20843616

  14. Enhancement of the Antifungal Activity of Antimicrobial Drugs by Eugenia uniflora L.

    PubMed Central

    Santos, Karla K.A.; Matias, Edinardo F.F.; Tintino, Saulo R.; Souza, Celestina E.S.; Braga, Maria F.B.M.; Guedes, Gláucia M.M.; Costa, José G.M.; Menezes, Irwin R.A.

    2013-01-01

    Abstract Candidiasis is the most frequent infection by opportunistic fungi such as Candida albicans, Candida tropicalis, and Candida krusei. Ethanol extract from Eugenia uniflora was assayed, for its antifungal activity, either alone or combined with four selected chemotherapeutic antimicrobial agents, including anphotericin B, mebendazole, nistatin, and metronidazole against these strains. The obtained results indicated that the association of the extract of E. uniflora to metronidazole showed a potential antifungal activity against C. tropicalis. However, no synergistic activity against the other strains was observed, as observed when the extract was associated with the other, not enhancing their antifungal activity. PMID:23819641

  15. Enhancement of the antifungal activity of antimicrobial drugs by Eugenia uniflora L.

    PubMed

    Santos, Karla K A; Matias, Edinardo F F; Tintino, Saulo R; Souza, Celestina E S; Braga, Maria F B M; Guedes, Gláucia M M; Costa, José G M; Menezes, Irwin R A; Coutinho, Henrique Douglas Melo

    2013-07-01

    Candidiasis is the most frequent infection by opportunistic fungi such as Candida albicans, Candida tropicalis, and Candida krusei. Ethanol extract from Eugenia uniflora was assayed, for its antifungal activity, either alone or combined with four selected chemotherapeutic antimicrobial agents, including anphotericin B, mebendazole, nistatin, and metronidazole against these strains. The obtained results indicated that the association of the extract of E. uniflora to metronidazole showed a potential antifungal activity against C. tropicalis. However, no synergistic activity against the other strains was observed, as observed when the extract was associated with the other, not enhancing their antifungal activity. PMID:23819641

  16. Population-based survey of filamentous fungi and antifungal resistance in Spain (FILPOP Study).

    PubMed

    Alastruey-Izquierdo, A; Mellado, E; Peláez, T; Pemán, J; Zapico, S; Alvarez, M; Rodríguez-Tudela, J L; Cuenca-Estrella, M

    2013-07-01

    A population-based survey was conducted to investigate the epidemiology of and antifungal resistance in Spanish clinical strains of filamentous fungi isolated from deep tissue samples, blood cultures, and respiratory samples. The study was conducted in two different periods (October 2010 and May 2011) to analyze seasonal variations. A total of 325 strains were isolated in 29 different hospitals. The average prevalence was 0.016/1,000 inhabitants [corrected]. Strains were identified by sequencing of DNA targets and susceptibility testing by the European Committee for Antimicrobial Susceptibility Testing reference procedure. The most frequently isolated genus was Aspergillus, accounting for 86.3% of the isolates, followed by Scedosporium at 4.7%; the order Mucorales at 2.5%; Penicillium at 2.2%, and Fusarium at 1.2%. The most frequent species was Aspergillus fumigatus (48.5%), followed by A. flavus (8.4%), A. terreus (8.1%), A. tubingensis (6.8%), and A. niger (6.5%). Cryptic/sibling Aspergillus species accounted for 12% of the cases. Resistance to amphotericin B was found in 10.8% of the isolates tested, while extended-spectrum triazole resistance ranged from 10 to 12.7%, depending on the azole tested. Antifungal resistance was more common among emerging species such as those of Scedosporium and Mucorales and also among cryptic species of Aspergillus, with 40% of these isolates showing resistance to all of the antifungal compounds tested. Cryptic Aspergillus species seem to be underestimated, and their correct classification could be clinically relevant. The performance of antifungal susceptibility testing of the strains implicated in deep infections and multicentric studies is recommended to evaluate the incidence of these cryptic species in other geographic areas. PMID:23669377

  17. Population-Based Survey of Filamentous Fungi and Antifungal Resistance in Spain (FILPOP Study)

    PubMed Central

    Mellado, E.; Peláez, T.; Pemán, J.; Zapico, S.; Alvarez, M.; Rodríguez-Tudela, J. L.; Cuenca-Estrella, M.

    2013-01-01

    A population-based survey was conducted to investigate the epidemiology of and antifungal resistance in Spanish clinical strains of filamentous fungi isolated from deep tissue samples, blood cultures, and respiratory samples. The study was conducted in two different periods (October 2010 and May 2011) to analyze seasonal variations. A total of 325 strains were isolated in 29 different hospitals. The average prevalence was 0.0016/1,000 inhabitants. Strains were identified by sequencing of DNA targets and susceptibility testing by the European Committee for Antimicrobial Susceptibility Testing reference procedure. The most frequently isolated genus was Aspergillus, accounting for 86.3% of the isolates, followed by Scedosporium at 4.7%; the order Mucorales at 2.5%; Penicillium at 2.2%, and Fusarium at 1.2%. The most frequent species was Aspergillus fumigatus (48.5%), followed by A. flavus (8.4%), A. terreus (8.1%), A. tubingensis (6.8%), and A. niger (6.5%). Cryptic/sibling Aspergillus species accounted for 12% of the cases. Resistance to amphotericin B was found in 10.8% of the isolates tested, while extended-spectrum triazole resistance ranged from 10 to 12.7%, depending on the azole tested. Antifungal resistance was more common among emerging species such as those of Scedosporium and Mucorales and also among cryptic species of Aspergillus, with 40% of these isolates showing resistance to all of the antifungal compounds tested. Cryptic Aspergillus species seem to be underestimated, and their correct classification could be clinically relevant. The performance of antifungal susceptibility testing of the strains implicated in deep infections and multicentric studies is recommended to evaluate the incidence of these cryptic species in other geographic areas. PMID:23669377

  18. Antifungal susceptibility and virulence factors of clinically isolated dermatophytes in Tehran, Iran

    PubMed Central

    Afshari, Mohammad Ali; Shams-Ghahfarokhi, Masoomeh; Razzaghi-Abyaneh, Mehdi

    2016-01-01

    Background and Objectives: Dermatophytes possess a wide array of virulence factors and various antifungal susceptibility patterns which influence their pathogenesis in humans and animals. The aim of this study was to evaluate antifungal susceptibility and keratinase and proteinase activity of 49 dermatophyte strains from the genera Microsporum, Trichophyton and Epidermophyton which were isolated from human cases of dermatophytosis. Materials and Methods: Forty-nine dermatophyte strains isolated from clinical samples were cultured on general and specific culture media. Keratinase and proteinase activity was screened on solid mineral media and confirmed in liquid cultures. Drug susceptibility toward azoles (fluconazole, ketoconazole and itraconazole), griseofulvin and terbinafine was evaluated using disk diffusion method on Mueller-Hinton agar and minimum inhibitory concentrations (MICs) were determined using microbroth dilution assay according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: Our results indicated that clinically isolated dermatophytes from 7 major species produced keratinase and proteinase at different extents. The mean keratinase and proteinase activity was reported as 6.69 ± 0.31 (U/ml) and 2.10 ± 0.22 (U/ml) respectively. Disk diffusion and microbroth dilution (MIC) results of antifungal susceptibility testing showed that ketoconazole was the most effective drug against Epidermophyton floccosum and Trichophyton mentagrophytes, itraconazole against T. rubrum and E. floccosum, and griseofulvin and terbinafine against Trichophyton verrucosum. Our results showed that all dermatophyte isolates were resistant to fluconazole. Overall, ketoconazole and itraconazole were the most effective drugs for all dermatophyte species tested. Conclusion: Our results showed that antifungal susceptibility testing is an urgent need to select drugs of choice for treatment of different types of dermatophytosis and further indicated the

  19. Synthesis and antifungal activity of novel triazole compounds containing piperazine moiety.

    PubMed

    Wang, Yanwei; Xu, Kehan; Bai, Guojing; Huang, Lei; Wu, Qiuye; Pan, Weihua; Yu, Shichong

    2014-01-01

    Design and synthesis of triazole library antifungal agents having piperazine side chains, analogues to fluconazole were documented. The synthesis highlighted utilization of the click chemistry on the basis of the active site of the cytochrome P450 14α-demethylase (CYP51). Their structures were characterized by (1)H-NMR, (13)C-NMR, MS and IR. The influences of piperazine moiety on in vitro antifungal activities of all the target compounds were evaluated against eight human pathogenic fungi. PMID:25090121

  20. Selected mechanisms of molecular resistance of Candida albicans to azole drugs.

    PubMed

    Gołąbek, Karolina; Strzelczyk, Joanna Katarzyna; Owczarek, Aleksander; Cuber, Piotr; Ślemp-Migiel, Anna; Wiczkowski, Andrzej

    2015-01-01

    A phenomenon of increasing resistance of Candida spp. to azoles has been observed for several years now. One of the mechanisms of lack of sensitivity to azoles is associated with CDR1, CDR2, MRD1 genes (their products are active transport pumps conditioning drug efflux from pathogen's cell), and ERG11 gene (encoding lanosterol 14α-demethylase). Test material was 120 strains of Candida albicans (60 resistant and 60 susceptible to azole drugs) obtained from clinical samples. The first stage of experiment assessed the expression of CDR1, CDR2, MDR1 and ERG11 genes by Q-PCR. The impact of ERG11 gene's mutations on the expression of this gene was analysed. The final stage of the experiment assessed the level of genome methylation of Candida albicans strains. An increase in the expression of CDR2, MDR1 and ERG11 was observed in azole-resistant strains of Candida albicans in comparison to strains sensitive to this class of drugs. Furthermore, 19 changes in the sequence of ERG11 were detected in tested strains. Four of the discovered mutations: T495A, A530C, G622A and A945C led to the following amino acid substitutions: D116E, K128T, V159I and E266D, respectively. It has also been found that statistically five mutations: T462C, G1309A, C216T, C1257T and A945C affected the expression of ERG11. The applied method of assessing the level of methylation of Candida albicans genome did not confirm its role in the development of resistance to azoles. The results indicate however, that resistance of Candida albicans strains to azole drugs is multifactorial. PMID:25901298

  1. Synergistic Antifungal Effect of Glabridin and Fluconazole

    PubMed Central

    Liu, Wei; Li, Li Ping; Zhang, Jun Dong; Li, Qun; Shen, Hui; Chen, Si Min; He, Li Juan; Yan, Lan; Xu, Guo Tong; An, Mao Mao; Jiang, Yuan Ying

    2014-01-01

    The incidence of invasive fungal infections is increasing in recent years. The present study mainly investigated glabridin (Gla) alone and especially in combination with fluconazole (FLC) against Cryptococcus neoformans and Candida species (Candida albicans, Candida tropicalis, Candida krusei, Candida parapsilosis and Candida Glabratas) by different methods. The minimal inhibitory concentration (MIC) and the minimal fungicidal concentration (MFC) indicated that Gla possessed a broad-spectrum antifungal activity at relatively high concentrations. After combining with FLC, Gla exerted a potent synergistic effect against drug-resistant C. albicans and C. tropicalis at lower concentrations when interpreted by fractional inhibitory concentration index (FICI). Disk diffusion test and time-killing test confirming the synergistic fungicidal effect. Cell growth tests suggested that the synergistic effect of the two drugs depended more on the concentration of Gla. The cell envelop damage including a significant decrease of cell size and membrane permeability increasing were found after Gla treatment. Together, our results suggested that Gla possessed a synergistic effect with FLC and the cell envelope damage maybe contributed to the synergistic effect, which providing new information for developing novel antifungal agents. PMID:25058485

  2. Mechanisms of echinocandin antifungal drug resistance

    PubMed Central

    Perlin, David S.

    2015-01-01

    Fungal infections due to Candida and Aspergillus species cause extensive morbidity and mortality, especially among immunosuppressed patients, and antifungal therapy is critical to patient management. Yet only a few drug classes are available to treat invasive fungal diseases, and this problem is compounded by the emergence of antifungal resistance. Echinocandin drugs are the preferred choice to treat candidiasis. They are the first cell wall–active agents and target the fungal-specific enzyme glucan synthase, which catalyzes the biosynthesis of β-1,3-glucan, a key cell wall polymer. Therapeutic failures occur rarely among common Candida species, with the exception of Candida glabrata, which are frequently multidrug resistant. Echinocandin resistance in susceptible species is always acquired during therapy. The mechanism of resistance involves amino acid changes in hot-spot regions of Fks subunits of glucan synthase, which decrease the sensitivity of the enzyme to drug. Cellular stress response pathways lead to drug adaptation, which promote the formation of resistant fks strains. Clinical factors promoting echinocandin resistance include empiric therapy, prophylaxis, gastrointestinal reservoirs, and intra-abdominal infections. A better understanding of the echinocandin resistance mechanism, along with cellular and clinical factors promoting resistance, will promote more effective strategies to overcome and prevent echinocandin resistance. PMID:26190298

  3. Augmenting the efficacy of antifungal intervention via chemo-biological approaches

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mycotic infection is becoming a serious health problem since effective antifungal agents for control of pathogenic fungi, especially drug-resistant pathogens, is often very limited. Fungal resistance to antimycotic agents frequently involves mutations caused by environmental stressors. In fungal pat...

  4. Stepwise design, synthesis, and in vitro antifungal screening of (Z)-substituted-propenoic acid derivatives with potent broad-spectrum antifungal activity

    PubMed Central

    Khedr, Mohammed A

    2015-01-01

    Fungal infections are a main reason for the high mortality rate worldwide. It is a challenge to design selective antifungal agents with broad-spectrum activity. Lanosterol 14α-demethylase is an attractive target in the design of antifungal agents. Seven compounds were selected from a number of designed compounds using a rational docking study. These compounds were synthesized and evaluated for their antifungal activity. In silico study results showed the high binding affinity to lanosterol 14α-demethylase (−24.49 and −25.83 kcal/mol) for compounds V and VII, respectively; these values were greater than those for miconazole (−18.19 kcal/mol) and fluconazole (−16.08 kcal/mol). Compound V emerged as the most potent antifungal agent among all compounds with a half maximal inhibitory concentration of 7.01, 7.59, 7.25, 31.6, and 41.6 µg/mL against Candida albicans, Candida parapsilosis, Aspergillus niger, Trichophyton rubrum, and Trichophyton mentagrophytes, respectively. The antifungal activity for most of the synthesized compounds was more potent than that of miconazole and fluconazole. PMID:26309398

  5. Searching new antifungals: The use of in vitro and in vivo methods for evaluation of natural compounds.

    PubMed

    Scorzoni, Liliana; Sangalli-Leite, Fernanda; de Lacorte Singulani, Junya; de Paula E Silva, Ana Carolina Alves; Costa-Orlandi, Caroline Barcelos; Fusco-Almeida, Ana Marisa; Mendes-Giannini, Maria José Soares

    2016-04-01

    In the last decades, the increased number of immunocompromised patients has led to the emergence of many forms of fungal infections. Furthermore, there are a restricted arsenal of antifungals available and an increase in the development of resistance to antifungal drugs. Because of these disadvantages, the search for new antifungal agents in natural sources has increased. The development of these new antifungal drugs involves various steps and methodologies. The evaluation of the in vitro antifungal activity and cytotoxicity are the first steps in the screening. There is also the possibility of antifungal combinations to improve the therapy and reduce toxicity. Despite that, the application of the new antifungal candidate could be used in association with photodynamic therapy or using nanotechnology as an ally. In vivo tests can be performed to evaluate the efficacy and toxicity using conventional and alternative animal models. In this work, we review the methods available for the evaluation of the antifungal activity and safety of natural products, as well as the recent advances of new technology in the application of natural products for antifungal therapy. PMID:26853122

  6. Probiotics as Antifungals in Mucosal Candidiasis.

    PubMed

    Matsubara, Victor H; Bandara, H M H N; Mayer, Marcia P A; Samaranayake, Lakshman P

    2016-05-01

    Candidais an opportunistic pathogen that causes mucosal and deep systemic candidiasis. The emergence of drug resistance and the side effects of currently available antifungals have restricted their use as long-term prophylactic agents for candidal infections. Given this scenario, probiotics have been suggested as a useful alternative for the management of candidiasis. We analyzed the available data on the efficacy of probiotics in candidal colonization of host surfaces. A number of well-controlled studies indicate that probiotics, particularly lactobacilli, suppressCandidagrowth and biofilm development in vitro.A few clinical trials have also shown the beneficial effects of probiotics in reducing oral, vaginal, and enteric colonization byCandida; alleviation of clinical signs and symptoms; and, in some cases, reducing the incidence of invasive fungal infection in critically ill patients. Probiotics may serve in the future as a worthy ally in the battle against chronic mucosal candidal infections. PMID:26826375

  7. Activation of Melanin Synthesis in Alternaria infectoria by Antifungal Drugs

    PubMed Central

    Fernandes, Chantal; Prados-Rosales, Rafael; Silva, Branca M. A.; Nakouzi-Naranjo, Antonio; Zuzarte, Mónica; Chatterjee, Subhasish; Stark, Ruth E.; Casadevall, Arturo

    2015-01-01

    The importance of Alternaria species fungi to human health ranges from their role as etiological agents of serious infections with poor prognoses in immunosuppressed individuals to their association with respiratory allergic diseases. The present work focuses on Alternaria infectoria, which was used as a model organism of the genus, and was designed to unravel melanin production in response to antifungals. After we characterized the pigment produced by A. infectoria, we studied the dynamics of 1,8-dihydroxynaphthalene (DHN)-melanin production during growth, the degree of melanization in response to antifungals, and how melanization affected susceptibility to several classes of therapeutic drugs. We demonstrate that A. infectoria increased melanin deposition in cell walls in response to nikkomycin Z, caspofungin, and itraconazole but not in response to fluconazole or amphotericin B. These results indicate that A. infectoria activates DHN-melanin synthesis in response to certain antifungal drugs, possibly as a protective mechanism against these drugs. Inhibition of DHN-melanin synthesis by pyroquilon resulted in a lower minimum effective concentration (MEC) of caspofungin and enhanced morphological changes (increased hyphal balloon size), characterized by thinner and less organized A. infectoria cell walls. In summary, A. infectoria synthesizes melanin in response to certain antifungal drugs, and its susceptibility is influenced by melanization, suggesting the therapeutic potential of drug combinations that affect melanin synthesis. PMID:26711773

  8. Activation of Melanin Synthesis in Alternaria infectoria by Antifungal Drugs.

    PubMed

    Fernandes, Chantal; Prados-Rosales, Rafael; Silva, Branca M A; Nakouzi-Naranjo, Antonio; Zuzarte, Mónica; Chatterjee, Subhasish; Stark, Ruth E; Casadevall, Arturo; Gonçalves, Teresa

    2016-03-01

    The importance of Alternaria species fungi to human health ranges from their role as etiological agents of serious infections with poor prognoses in immunosuppressed individuals to their association with respiratory allergic diseases. The present work focuses on Alternaria infectoria, which was used as a model organism of the genus, and was designed to unravel melanin production in response to antifungals. After we characterized the pigment produced by A. infectoria, we studied the dynamics of 1,8-dihydroxynaphthalene (DHN)-melanin production during growth, the degree of melanization in response to antifungals, and how melanization affected susceptibility to several classes of therapeutic drugs. We demonstrate that A. infectoria increased melanin deposition in cell walls in response to nikkomycin Z, caspofungin, and itraconazole but not in response to fluconazole or amphotericin B. These results indicate that A. infectoria activates DHN-melanin synthesis in response to certain antifungal drugs, possibly as a protective mechanism against these drugs. Inhibition of DHN-melanin synthesis by pyroquilon resulted in a lower minimum effective concentration (MEC) of caspofungin and enhanced morphological changes (increased hyphal balloon size), characterized by thinner and less organized A. infectoria cell walls. In summary, A. infectoria synthesizes melanin in response to certain antifungal drugs, and its susceptibility is influenced by melanization, suggesting the therapeutic potential of drug combinations that affect melanin synthesis. PMID:26711773

  9. Human Pharmacogenomic Variations and Their Implications for Antifungal Efficacy

    PubMed Central

    Meletiadis, Joseph; Chanock, Stephen; Walsh, Thomas J.

    2006-01-01

    Pharmacogenomics is defined as the study of the impacts of heritable traits on pharmacology and toxicology. Candidate genes with potential pharmacogenomic importance include drug transporters involved in absorption and excretion, phase I enzymes (e.g., cytochrome P450-dependent mixed-function oxidases) and phase II enzymes (e.g., glucuronosyltransferases) contributing to metabolism, and those molecules (e.g., albumin, A1-acid glycoprotein, and lipoproteins) involved in the distribution of antifungal compounds. By using the tools of population genetics to define interindividual differences in drug absorption, distribution, metabolism, and excretion, pharmacogenomic models for genetic variations in antifungal pharmacokinetics can be derived. Pharmacogenomic factors may become especially important in the treatment of immunocompromised patients or those with persistent or refractory mycoses that cannot be explained by elevated MICs and where rational dosage optimization of the antifungal agent may be particularly critical. Pharmacogenomics has the potential to shift the paradigm of therapy and to improve the selection of antifungal compounds and adjustment of dosage based upon individual variations in drug absorption, metabolism, and excretion. PMID:17041143

  10. Naturally azole-resistant Leishmania braziliensis promastigotes are rendered susceptible in the presence of terbinafine: comparative study with azole-susceptible Leishmania mexicana promastigotes.

    PubMed Central

    Rangel, H; Dagger, F; Hernandez, A; Liendo, A; Urbina, J A

    1996-01-01

    Leishmania braziliensis (isolate 2903) was naturally resistant to ketoconazole or the bis-triazole D0870, inhibitors of sterol C-14 demethylase, which produced only moderate effects on the proliferation of promastigotes at 10 microM. In contrast, Leishmania mexicana (isolate NR) was extremely susceptible to the azoles, as complete growth arrest and cell lysis were induced by incubation of the parasites with 0.05 microM concentrations of the drugs for 72 h. The opposite response was observed with terbinafine, an inhibitor of squalene epoxidase: L. braziliensis 2903 was three times more susceptible to the drug than L. mexicana NR (MICs of 5 and 15 microM, respectively). However, when the L. braziliensis stock was grown in the presence of 1 microM terbinafine, which by itself produced only marginal (< 10%) effects on growth, it became highly susceptible to the azoles, with an MIC of 0.03 microM. Analysis of cellular free sterols by high-resolution capillary gas chromatography coupled to mass spectrometry showed that 14-methyl sterols can support normal growth of L. braziliensis 2903 but not of L. mexicana NR. On the other hand, the higher susceptibility of the L. braziliensis isolate to terbinafine was correlated with a massive accumulation of squalene in the presence of the allylamine while no significant effects on L. mexicana sterol composition were observed at drug concentrations up to 1 microM. Thus, the > 300-fold increase in the susceptibility of L. braziliensis promastigotes to azoles in the presence of terbinafine was attributed to the combined effect of squalene and the methylated sterol precursors on the physical properties of the cell's membranes, leading to the loss of cell viability. Combination therapy with azoles and terbinafine in the treatment of human L. braziliensis infections deserves further study. PMID:9124841

  11. Trends in antifungal susceptibility and virulence of Candida spp. from the nasolacrimal duct of horses.

    PubMed

    Brilhante, Raimunda Sâmia Nogueira; Bittencourt, Paula Vago; Castelo-Branco, Débora de Souza Collares Maia; de Oliveira, Jonathas Sales; Alencar, Lucas Pereira de; Cordeiro, Rossana de Aguiar; Pinheiro, Mariana; Nogueira-Filho, Evilázio Fernandes; Pereira-Neto, Waldemiro de Aquino; Sidrim, José Júlio Costa; Rocha, Marcos Fábio Gadelha

    2016-02-01

    This was a cross-sectional study to investigate the antifungal susceptibility and production of virulence factors in strains of Candida isolated from the outlet and the lumen of the nasolacrimal duct of horses in the state of Ceará, Brazil. The samples were obtained from 103 horses. Sterile cotton swabs were used to collect the material from the outlet of the nasolacrimal duct and urethral probes, for the instillation of 2 ml of saline solution, were used to collect samples from the lumen of the nasolacrimal duct. A total of 77 Candida isolates were obtained, with C. famata, C. tropicalis, C. guilliermondii, and C. parapsilosis sensu lato as the most prevalent species. One isolate (C. glabrata) was resistant to caspofungin. One isolate was resistant only to fluconazole (C. parapsilosis sensu lato), 11 were resistant only to itraconazole (7 C. tropicalis, 2 C. guilliermondii, 1 C. famata, 1 C. parapsilosis sensu lato), while eight C. tropicalis showed resistance to both azoles. Overall, 28 isolates produced phospholipases and 12 produced proteases. These results highlight the importance of investigating the antifungal susceptibility and virulence trends of Candida spp. from the microbiota of the nasolacrimal duct of horses. PMID:26483435

  12. First description of Candida nivariensis in Brazil: antifungal susceptibility profile and potential virulence attributes.

    PubMed

    Figueiredo-Carvalho, Maria Helena Galdino; Ramos, Livia de Souza; Barbedo, Leonardo Silva; Chaves, Alessandra Leal da Silva; Muramoto, Ilda Akemi; Santos, André Luis Souza dos; Almeida-Paes, Rodrigo; Zancopé-Oliveira, Rosely Maria

    2016-01-01

    This study evaluated the antifungal susceptibility profile and the production of potential virulence attributes in a clinical strain of Candida nivariensis for the first time in Brazil, as identified by sequencing the internal transcribed spacer (ITS)1-5.8S-ITS2 region and D1/D2 domains of the 28S of the rDNA. For comparative purposes, tests were also performed with reference strains. All strains presented low planktonic minimal inhibitory concentrations (PMICs) to amphotericin B (AMB), caspofungin (CAS), and voriconazole. However, our strain showed elevated planktonic MICs to posaconazole (POS) and itraconazole, in addition to fluconazole resistance. Adherence to inert surfaces was conducted onto glass and polystyrene. The biofilm formation and antifungal susceptibility on biofilm-growing cells were evaluated by crystal violet staining and a XTT reduction assay. All fungal strains were able to bind both tested surfaces and form biofilm, with a binding preference to polystyrene (p < 0.001). AMB promoted significant reductions (≈50%) in biofilm production by our C. nivariensis strain using both methodologies. This reduction was also observed for CAS and POS, but only in the XTT assay. All strains were excellent protease producers and moderate phytase producers, but lipases were not detected. This study reinforces the pathogenic potential of C. nivariensis and its possible resistance profile to the azolic drugs generally used for candidiasis management. PMID:26814644

  13. First description of Candida nivariensis in Brazil: antifungal susceptibility profile and potential virulence attributes

    PubMed Central

    Figueiredo-Carvalho, Maria Helena Galdino; Ramos, Livia de Souza; Barbedo, Leonardo Silva; Chaves, Alessandra Leal da Silva; Muramoto, Ilda Akemi; dos Santos, André Luis Souza; Almeida-Paes, Rodrigo; Zancopé-Oliveira, Rosely Maria

    2016-01-01

    This study evaluated the antifungal susceptibility profile and the production of potential virulence attributes in a clinical strain of Candida nivariensis for the first time in Brazil, as identified by sequencing the internal transcribed spacer (ITS)1-5.8S-ITS2 region and D1/D2 domains of the 28S of the rDNA. For comparative purposes, tests were also performed with reference strains. All strains presented low planktonic minimal inhibitory concentrations (PMICs) to amphotericin B (AMB), caspofungin (CAS), and voriconazole. However, our strain showed elevated planktonic MICs to posaconazole (POS) and itraconazole, in addition to fluconazole resistance. Adherence to inert surfaces was conducted onto glass and polystyrene. The biofilm formation and antifungal susceptibility on biofilm-growing cells were evaluated by crystal violet staining and a XTT reduction assay. All fungal strains were able to bind both tested surfaces and form biofilm, with a binding preference to polystyrene (p < 0.001). AMB promoted significant reductions (≈50%) in biofilm production by our C. nivariensis strain using both methodologies. This reduction was also observed for CAS and POS, but only in the XTT assay. All strains were excellent protease producers and moderate phytase producers, but lipases were not detected. This study reinforces the pathogenic potential of C. nivariensis and its possible resistance profile to the azolic drugs generally used for candidiasis management. PMID:26814644

  14. Antifungal Activity of Bee Venom and Sweet Bee Venom against Clinically Isolated Candida albicans

    PubMed Central

    Lee, Seung-Bae

    2016-01-01

    Objectives: The purpose of this study was to investigate the antifungal effect of bee venom (BV) and sweet bee venom (SBV) against Candida albicans (C. albicans) clinical isolates. Methods: In this study, BV and SBV were examined for antifungal activities against the Korean Collection for Type Cultures (KCTC) strain and 10 clinical isolates of C. albicans. The disk diffusion method was used to measure the antifungal activity and minimum inhibitory concentration (MIC) assays were performed by using a broth microdilution method. Also, a killing curve assay was conducted to investigate the kinetics of the anti- fungal action. Results: BV and SBV showed antifungal activity against 10 clinical isolates of C. albicans that were cultured from blood and the vagina by using disk diffusion method. The MIC values obtained for clinical isolates by using the broth microdilution method varied from 62.5 μg/ mL to 125 μg/mL for BV and from 15.63 μg/mL to 62.5 μg/mL for SBV. In the killing-curve assay, SBV behaved as amphotericin B, which was used as positive control, did. The antifungal efficacy of SBV was much higher than that of BV. Conclusion: BV and SBV showed antifungal activity against C. albicans clinical strains that were isolated from blood and the vagina. Especially, SBV might be a candidate for a new antifungal agent against C. albicans clinical isolates. PMID:27280049

  15. Continuous infusion of amphotericin B deoxycholate: an innovative, low-cost strategy in antifungal treatment.

    PubMed

    Falci, Diego R; dos Santos, Rodrigo P; Wirth, Fernanda; Goldani, Luciano Z

    2011-03-01

    The combination of amphotericin B and sodium deoxycholate is the formulation most used in clinical practice. The development of new agents such as amphotericin with lipid formulations, caspofungin, voriconazole and other azolic derivatives, promoted alternatives to amphotericin B deoxycholate. However, because of the high cost of these new drugs, their use is difficult in a scenario of limited resources. A few strategies have been devised to make the use of amphotericin B deoxycholate less toxic. In this review, we seek to describe the accumulated knowledge about this molecule, with focus on its use in continuous infusion, which appears to be an alternative to reduce toxicity, while maintaining its clinical efficacy. PMID:19878457

  16. Antifungal activity of redox-active benzaldehydes that target cellular antioxidation

    PubMed Central

    2011-01-01

    Background Disruption of cellular antioxidation systems should be an effective method for control of fungal pathogens. Such disruption can be achieved with redox-active compounds. Natural phenolic compounds can serve as potent redox cyclers that inhibit microbial growth through destabilization of cellular redox homeostasis and/or antioxidation systems. The aim of this study was to identify benzaldehydes that disrupt the fungal antioxidation system. These compounds could then function as chemosensitizing agents in concert with conventional drugs or fungicides to improve antifungal efficacy. Methods Benzaldehydes were tested as natural antifungal agents against strains of Aspergillus fumigatus, A. flavus, A. terreus and Penicillium expansum, fungi that are causative agents of human invasive aspergillosis and/or are mycotoxigenic. The yeast Saccharomyces cerevisiae was also used as a model system for identifying gene targets of benzaldehydes. The efficacy of screened compounds as effective chemosensitizers or as antifungal agents in formulations was tested with methods outlined by the Clinical Laboratory Standards Institute (CLSI). Results Several benzaldehydes are identified having potent antifungal activity. Structure-activity analysis reveals that antifungal activity increases by the presence of an ortho-hydroxyl group in the aromatic ring. Use of deletion mutants in the oxidative stress-response pathway of S. cerevisiae (sod1Δ, sod2Δ, glr1Δ) and two mitogen-activated protein kinase (MAPK) mutants of A. fumigatus (sakAΔ, mpkCΔ), indicates antifungal activity of the benzaldehydes is through disruption of cellular antioxidation. Certain benzaldehydes, in combination with phenylpyrroles, overcome tolerance of A. fumigatus MAPK mutants to this agent and/or increase sensitivity of fungal pathogens to mitochondrial respiration inhibitory agents. Synergistic chemosensitization greatly lowers minimum inhibitory (MIC) or fungicidal (MFC) concentrations. Effective

  17. A Sterol-Regulatory Element Binding Protein Is Required for Cell Polarity, Hypoxia Adaptation, Azole Drug Resistance, and Virulence in Aspergillus fumigatus

    PubMed Central

    Willger, Sven D.; Puttikamonkul, Srisombat; Kim, Kwang-Hyung; Burritt, James B.; Grahl, Nora; Metzler, Laurel J.; Barbuch, Robert; Bard, Martin; Lawrence, Christopher B.; Cramer, Robert A.

    2008-01-01

    At the site of microbial infections, the significant influx of immune effector cells and the necrosis of tissue by the invading pathogen generate hypoxic microenvironments in which both the pathogen and host cells must survive. Currently, whether hypoxia adaptation is an important virulence attribute of opportunistic pathogenic molds is unknown. Here we report the characterization of a sterol-regulatory element binding protein, SrbA, in the opportunistic pathogenic mold, Aspergillus fumigatus. Loss of SrbA results in a mutant strain of the fungus that is incapable of growth in a hypoxic environment and consequently incapable of causing disease in two distinct murine models of invasive pulmonary aspergillosis (IPA). Transcriptional profiling revealed 87 genes that are affected by loss of SrbA function. Annotation of these genes implicated SrbA in maintaining sterol biosynthesis and hyphal morphology. Further examination of the SrbA null mutant consequently revealed that SrbA plays a critical role in ergosterol biosynthesis, resistance to the azole class of antifungal drugs, and in maintenance of cell polarity in A. fumigatus. Significantly, the SrbA null mutant was highly susceptible to fluconazole and voriconazole. Thus, these findings present a new function of SREBP proteins in filamentous fungi, and demonstrate for the first time that hypoxia adaptation is likely an important virulence attribute of pathogenic molds. PMID:18989462

  18. Mechanisms of resistance to an azole fungicide in the grapevine powdery mildew fungus, Erysiphe necator

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We studied the mechanisms of azole resistance in the grapevine powdery mildew fungus, Erysiphe necator, by quantifying the sensitivity to myclobutanil (EC50) in 65 isolates from the eastern U.S. and 12 from Chile. From each isolate, we sequenced the gene for sterol 14a-demethylase (CYP51), and measu...

  19. Erg11 mutations associated with azole resistance in clinical isolates of Candida albicans.

    PubMed

    Xiang, Ming-Jie; Liu, Jin-Yan; Ni, Pei-Hua; Wang, Shengzheng; Shi, Ce; Wei, Bing; Ni, Yu-Xing; Ge, Hai-Liang

    2013-06-01

    The widespread use of azoles has led to increasing azole resistance among Candida albicans strains. One mechanism of azole resistance involves point mutations in the ERG11 gene, which encodes the target enzyme (cytochrome P450 lanosterol 14α-demethylase). In the present study, we amplified and sequenced the ERG11 gene of 23 C. albicans clinical isolates. Seventeen mutations encoding distinct amino acid substitutions were found, of which seven (K143Q, Y205E, A255V, E260V, N435V, G472R, and D502E) were novel. We further verified the contribution of the amino acid substitutions to azole resistance using site-directed mutagenesis of the ERG11 gene to recreate these mutations for heterologous expression in Saccharomyces cerevisiae. We observed that substitutions A114S, Y132H, Y132F, K143R, Y257H, and a new K143Q substitution contributed to significant increases (≧fourfold) in fluconazole and voriconazole resistance; changes in itraconazole resistance were not significant (≦twofold). PMID:23480635

  20. Dimeric fluorescent energy transfer dyes comprising asymmetric cyanine azole-indolenine chromophores

    DOEpatents

    Glazer, Alexander N.; Benson, Scott C.

    1996-01-01

    Novel fluorescent DNA-staining dyes are provided combining asymmetric cyanine azole-indolenine dyes, which provide for strong DNA affinity, large Stokes shifts and emission in the red region of the spectrum. The dyes find particular application in gel electrophoresis and for labels which may be bound to a variety of compositions in a variety of contexts.

  1. A Global Analysis of CYP51 Diversity and Azole Sensitivity in Rhynchosporium commune.

    PubMed

    Brunner, Patrick C; Stefansson, Tryggvi S; Fountaine, James; Richina, Veronica; McDonald, Bruce A

    2016-04-01

    CYP51 encodes the target site of the azole class of fungicides widely used in plant protection. Some ascomycete pathogens carry two CYP51 paralogs called CYP51A and CYP51B. A recent analysis of CYP51 sequences in 14 European isolates of the barley scald pathogen Rhynchosporium commune revealed three CYP51 paralogs, CYP51A, CYP51B, and a pseudogene called CYP51A-p. The same analysis showed that CYP51A exhibits a presence/absence polymorphism, with lower sensitivity to azole fungicides associated with the presence of a functional CYP51A. We analyzed a global collection of nearly 400 R. commune isolates to determine if these findings could be extended beyond Europe. Our results strongly support the hypothesis that CYP51A played a key role in the emergence of azole resistance globally and provide new evidence that the CYP51A gene in R. commune has further evolved, presumably in response to azole exposure. We also present evidence for recent long-distance movement of evolved CYP51A alleles, highlighting the risk associated with movement of fungicide resistance alleles among international trading partners. PMID:26623995

  2. cyp51A gene silencing using RNA interference in azole-resistant Aspergillus fumigatus.

    PubMed

    Mousavi, Bita; Hedayati, Mohammad T; Teimoori-Toolabi, Ladan; Guillot, Jacques; Alizadeh, Ahad; Badali, Hamid

    2015-12-01

    An increasing number of reports have described the emergence of acquired resistance of Aspergillus fumigatus to azole compounds. The primary mechanism of resistance in clinical isolates is the mutation of the azole drug target enzyme, which is encoded by the cyp51A gene. The aim of this study was to evaluate the impact of silencing the cyp51A gene in azole-resistant A. fumigatus isolates. A 21-nucleotide small-interfering RNA (siRNA) was designed based on the cDNA sequence of the A. fumigatus cyp51A gene. After silencing the cyp51A gene in germinated conidia (15, 20, 25 and 50 nM), azole-resistant A. fumigatus was cultured on broth media and gene expression was analysed by measuring the cyp51A mRNA level using RT-PCR assay. Hyphae were successfully transfected by siRNA and expression of the cyp51A gene was significantly reduced by siRNA at the concentration of 50 nM (P ≤ 0.05). In addition, at this siRNA concentration, the minimum inhibitory concentration of itraconazole for the treated cells was decreased, compared with that for untreated control cells, from 16 to 4 μg/ml. PMID:26448519

  3. Enhanced ratiometric fluorescent indicators for magnesium based on azoles of the heavier chalcogens.

    PubMed

    Afzal, Mohammad S; Pitteloud, Jean-Philippe; Buccella, Daniela

    2014-10-01

    Red-shifted fluorescent indicators for magnesium were developed by incorporation of sulfur or selenium in the azole moiety of 'fura' fluorophores. Single atom replacement in the acceptor of these ITC probes affords longer excitation and emission wavelengths as well as greater separation between excitation bands, valuable for ratiometric intracellular Mg(2+) imaging. PMID:25164869

  4. Purification and Identification of Two Antifungal Cyclic Peptides Produced by Bacillus amyloliquefaciens L-H15.

    PubMed

    Han, Yuzhu; Zhang, Bao; Shen, Qian; You, Chengzhen; Yu, Yaqiong; Li, Pinglan; Shang, Qingmao

    2015-08-01

    Bacillus amyloliquefaciens L-H15 with broad spectrum antifungal activity was used as a biocontrol agent to suppress Fusarium oxysporum and other soil-borne fungal plant pathogens. Two antifungal fractions were isolated by bioactivity-guided reversed-phase high-performance liquid chromatography. The two compounds were identified by tandem Q-TOF mass spectroscopy as C15 Iturin A (1) and a novel cyclic peptide with a molecular weight of 852.4 Da (2). Both compounds showed good inhibitory activities against three plant fungal pathogens in cylinder-plate diffusion assay. To our best knowledge, this is the first report on a cyclic antifungal peptide with a molecular weight of 852.4 Da. The strong antifungal activity suggests that the B. amyloliquefaciens L-H15 and its bioactive components might provide an alternative resource for the biocontrol of plant diseases and sustainable agriculture. PMID:26123083

  5. Fluconazole- and itraconazole-resistant Candida albicans strains from AIDS patients: multilocus enzyme electrophoresis analysis and antifungal susceptibilities.

    PubMed Central

    Le Guennec, R; Reynes, J; Mallié, M; Pujol, C; Janbon, F; Bastide, J M

    1995-01-01

    Multilocus enzyme electrophoresis and in vitro susceptibility testing with a broth microdilution method were used to analyze Candida albicans strain diversity in four AIDS patients with recurrent oropharyngeal candidiasis who successively developed clinical resistance to fluconazole (FCZ) and itraconazole (ITZ). One to ten colonies per sample were randomly chosen from oral washings collected before the initial FCZ treatment and just before every other antifungal treatment; a total of 98 isolates were analyzed. Multilocus enzyme electrophoresis analysis revealed 14 different electrophoretic types (ETs). Statistical analysis of genetic distances showed that C. albicans isolates clustered into five subpopulations (I to V). In each subpopulation, isolates are closely related, and genetic distances between subpopulations I to IV are short. In contrast, subpopulation V, which contained isolates typed as ET8 and ET14, is strongly divergent from the others; these isolates may represent atypical C. albicans isolates. Only one patient was infected with a single strain during the course of azole therapy; for the three remaining patients, variants of the same strain and different strains were concurrently isolated. Clinical FCZ resistance was clearly correlated with in vitro data for three patients. Moreover, MICs of ITZ increased during FCZ therapy, and MICs of ITZ which were > or = 1.56 micrograms/ml were found when clinical ITZ resistance occurred; isolates from subpopulation V showed the highest MICs of ITZ. Because of the emergence of clinical ITZ resistance after clinical FCZ resistance, the feasibility of long-term azole therapy for mucosal candidiasis in AIDS patients is questioned. PMID:8567915

  6. Antifungal Compounds from Piper Species

    PubMed Central

    Xu, Wen-Hui; Li, Xing-Cong

    2013-01-01

    This review documents chemical structures and antifungal activities of 68 compounds isolated from 22 Piper species of the plant family Piperaceae. These compounds include amides, flavonoids, prenylated benzoic acid derivatives, lignans, phenylpropanoids, butenolides, and cyclopentendiones. Some of them may serve as leads for potential pharmaceutical or agricultural fungicide development. PMID:24307889

  7. Antifungal activity of juniper extracts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sawdust from three species of Juniperus (i.e., J. virginianna, J. occidentalis, and J. ashei) were extracted with hexane or ethanol and the extracts tested for antifungal activity against four species of wood-rot fungi. These species studied represent the junipers with the greatest potential for co...

  8. Sporothrix schenckii complex in Iran: Molecular identification and antifungal susceptibility.

    PubMed

    Mahmoudi, Shahram; Zaini, Farideh; Kordbacheh, Parivash; Safara, Mahin; Heidari, Mansour

    2016-08-01

    Sporotrichosis is a global subcutaneous fungal infection caused by the Sporothrix schenckii complex. Sporotrichosis is an uncommon infection in Iran, and there have been no phenotypic, molecular typing or antifungal susceptibility studies of Sporothrix species. This study aimed to identify nine Iranian isolates of the S. schenckii complex to the species level using colony morphology, carbohydrate assimilation tests, and PCR-sequencing of the calmodulin gene. The antifungal susceptibilities of these Sporothrix isolates to five antifungal agents (amphotericin B (AMB), voriconazole (VRC), itraconazole (ITC), fluconazole (FLC), and terbinafine (TRB)) were also evaluated according to the M27-A3 and M38-A2 protocols of the Clinical and Laboratory Standards Institute for yeast and mycelial phases, respectively. Five of seven clinical isolates were identified as S. schenckii, and two clinical and two environmental isolates were identified as S. globosa. This is the first report of S. globosa in Iran. There was significant agreement (73%) between the results of the phenotypic and genotypic identification methods. TRB and ITC were the most effective antifungals against the Sporothrix isolates. The minimum inhibitory concentration (MIC) values of TRB for the yeast and mycelial phases of S. schenckii differed significantly. There was also a significant difference in the minimum fungicidal concentration (MFC) values of AMB and TRB for the two phases. Considering the low efficacy of VRC and FLC and the wide MIC ranges of AMB (1-16 μg/ml and 1-8 μg/ml for yeast and mycelial forms, respectively) observed in the present study, in vitro antifungal susceptibility testing should be performed to determine appropriate therapeutic regimens. PMID:26933207

  9. Novel antifungal drugs against fungal pathogens: do they provide promising results for treatment?

    PubMed

    Gedik, Habip; Şimşek, Funda; Yıldırmak, Taner; Kantürk, Arzu; Arıca, Deniz; Aydın, Demet; Demirel, Naciye; Yokuş, Osman

    2015-06-01

    The febrile neutropenia episodes of hematological patients and their outcomes were evaluated with respect to fungal pathogens and antifungal therapy in this retrospective study. All patients, who were older than 14 years of age and developed at least one neutropenic episode after chemotherapy due to hematological cancer from November 2010 to November 2012, were included into the study. We retrospectively collected demographic, treatment, and survival data of 126 patients with neutropenia and their 282 febrile episodes. The mean Multinational Association for Supportive Care in Cancer score was 17.18 ± 8.27. Systemic antifungal drugs were initiated in 22 patients with 30 culture-proven invasive fungal infections (IFIs), 25 attacks of 19 patients with probable invasive pulmonary aspergillosis (IPA), 42 attacks of 38 patients with possible IPA, and 31 attacks of 30 patients with suspected IFI. Voriconazole (VOR), caspofungin and liposomal amphotericin B were used to treat 72 episodes of 65 patients, 45 episodes of 37 patients and 34 episodes of 32 patients as a first-line therapy, respectively. Unfavorable conditions of our hematology ward are thought to increase the number of cases with invasive pulmonary aspergillosis and VOR use. It should be taken into consideration that increased systemic and per oral VOR usage predisposes patients to colonization and infection with azole-resistant fungal strains. Catheters should be removed in cases where patients' conditions are convenient to remove it. Acute myeloblastic leukemia cases that are more likely to develop invasive fungal infections should be monitored closely for early diagnosis and timely initiation of antifungal drugs which directly correlates with survival rates. PMID:25825558

  10. Conventional and alternative antifungal therapies to oral candidiasis

    PubMed Central

    Anibal, Paula Cristina; de Cássia Orlandi Sardi, Janaina; Peixoto, Iza Teixeira Alves; de Carvalho Moraes, Julianna Joanna; Höfling, José Francisco

    2010-01-01

    Candida-associated denture stomatitis is the most common form of oral candidal infection, with Candida albicans being the principal etiological agent. Candida adheres directly or via an intermediary layer of plaque-forming bacteria to denture acrylic. Despite antifungal therapy to treat denture stomatitis, infection is reestablished soon after the treatment ceases. In addition, many predisposing factors have been identified as important in the development of oral candidiasis, including malnourishment, common endocrine disorders, such as diabetis mellitus, antibacterial drug therapy, corticosteroids, radiotherapy and other immunocompromised conditions, such as acquired immunodeficiency syndrome (AIDS). These often results in increased tolerance to the most commonly used antifungals. So this review suggests new therapies to oral candidiasis. PMID:24031562

  11. Identification and properties of plasma membrane azole efflux pumps from the pathogenic fungi Cryptococcus gattii and Cryptococcus neoformans

    PubMed Central

    Basso, Luiz R.; Gast, Charles E.; Bruzual, Igor; Wong, Brian

    2015-01-01

    Objectives Cryptococcus gattii from the North American Northwest (NW) have higher azole MICs than do non-NW C. gattii or Cryptococcus neoformans. Since mechanisms of azole resistance in C. gattii are not known, we identified C. gattii and C. neoformans plasma membrane azole efflux pumps and characterized their properties. Methods The C. gattii R265 genome was searched for orthologues of known fungal azole efflux genes, expression of candidate genes was assessed by RT–PCR and the expressed genes' cDNAs were cloned and expressed in Saccharomyces cerevisiae. Azole MICs and intracellular [3H]fluconazole were measured in C. gattii and C. neoformans and in S. cerevisiae expressing each cDNA of interest, as was [3H]fluconazole uptake by post-Golgi vesicles (PGVs) isolated from S. cerevisiae sec6-4 mutants expressing each cDNA of interest. Results Intracellular [3H]fluconazole concentrations were inversely correlated with fluconazole MICs only in 25 NW C. gattii strains. S. cerevisiae expressing three C. gattii cDNAs (encoded by orthologues of C. neoformans AFR1 and MDR1 and the previously unstudied gene AFR2) and their C. neoformans counterparts had higher azole MICs and lower intracellular [3H]fluconazole concentrations than did empty-vector controls. PGVs from S. cerevisiae expressing all six Cryptococcus cDNAs also accumulated more [3H]fluconazole than did controls, and [3H]fluconazole transport by all six transporters of interest was ATP dependent and was inhibited by excess unlabelled fluconazole, voriconazole, itraconazole and posaconazole. Conclusions We conclude that C. gattii and C. neoformans AFR1, MDR1 and AFR2 encode ABC transporters that pump multiple azoles out of S. cerevisiae cells, thereby causing azole resistance. PMID:25630649

  12. Synthesis and Antifungal Activity of Functionalized 2,3-Spirostane Isomers

    PubMed Central

    Upadhyay, Sunil Kumar; Creech, Clinton C.; Bowdy, Katharine L.; Stevens, Edwin D.; Jursic, Branko S.; Neumann, Donna M.

    2011-01-01

    Invasive fungal infections are a major complication for individuals with compromised immune systems. One of the most significant challenges in the treatment of invasive fungal infections is the increased resistance of many organisms to widely used antifungals, making the development of novel antifungal agents essential. Many naturally occurring products have been found to be effective antimicrobial agents. In particular, saponins with spirostane glycosidic moieties- isolated from plant or marine species- have been shown to possess a range of antimicrobial properties. In this report, we outline a novel approach to the synthesis of a number of functionalized spirostane molecules that can be further used as building blocks for novel spirostane-linked glycosides and present results from the in vitro screenings of the antifungal potential of each derivative against four fungal species, including Candida albicans, Cryptococcus neoformans, Candida glabrata, and the filamentous fungus Aspergillus fumigatus. PMID:21489791

  13. The Yeast Anaerobic Response Element AR1b Regulates Aerobic Antifungal Drug-dependent Sterol Gene Expression*

    PubMed Central

    Gallo-Ebert, Christina; Donigan, Melissa; Liu, Hsing-Yin; Pascual, Florencia; Manners, Melissa; Pandya, Devanshi; Swanson, Robert; Gallagher, Denise; Chen, WeiWei; Carman, George M.; Nickels, Joseph T.

    2013-01-01

    Saccharomyces cerevisiae ergosterol biosynthesis, like cholesterol biosynthesis in mammals, is regulated at the transcriptional level by a sterol feedback mechanism. Yeast studies defined a 7-bp consensus sterol-response element (SRE) common to genes involved in sterol biosynthesis and two transcription factors, Upc2 and Ecm22, which direct transcription of sterol biosynthetic genes. The 7-bp consensus SRE is identical to the anaerobic response element, AR1c. Data indicate that Upc2 and Ecm22 function through binding to this SRE site. We now show that it is two novel anaerobic AR1b elements in the UPC2 promoter that direct global ERG gene expression in response to a block in de novo ergosterol biosynthesis, brought about by antifungal drug treatment. The AR1b elements are absolutely required for auto-induction of UPC2 gene expression and protein and require Upc2 and Ecm22 for function. We further demonstrate the direct binding of recombinant expressed S. cerevisiae ScUpc2 and pathogenic Candida albicans CaUpc2 and Candida glabrata CgUpc2 to AR1b and SRE/AR1c elements. Recombinant endogenous promoter studies show that the UPC2 anaerobic AR1b elements act in trans to regulate ergosterol gene expression. Our results indicate that Upc2 must occupy UPC2 AR1b elements in order for ERG gene expression induction to take place. Thus, the two UPC2-AR1b elements drive expression of all ERG genes necessary for maintaining normal antifungal susceptibility, as wild type cells lacking these elements have increased susceptibility to azole antifungal drugs. Therefore, targeting these specific sites for antifungal therapy represents a novel approach to treat systemic fungal infections. PMID:24163365

  14. A Prototype Antifungal Contact Lens

    PubMed Central

    Ciolino, Joseph B.; Hudson, Sarah P.; Mobbs, Ashley N.; Hoare, Todd R.; Iwata, Naomi G.; Fink, Gerald R.

    2011-01-01

    Purpose. To design a contact lens to treat and prevent fungal ocular infections. Methods. Curved contact lenses were created by encapsulating econazole-impregnated poly(lactic-co-glycolic) acid (PLGA) films in poly(hydroxyethyl methacrylate) (pHEMA) by ultraviolet photopolymerization. Release studies were conducted in phosphate-buffered saline at 37°C with continuous shaking. The contact lenses and their release media were tested in an antifungal assay against Candida albicans. Cross sections of the pre- and postrelease contact lenses were characterized by scanning electron microscopy and by Raman spectroscopy. Results. Econazole-eluting contact lenses provided extended antifungal activity against Candida albicans fungi. Fungicidal activity varied in duration and effectiveness depending on the mass of the econazole-PLGA film encapsulated in the contact lens. Conclusions. An econazole-eluting contact lens could be used as a treatment for fungal ocular infections. PMID:21527380

  15. Experimental models in predicting topical antifungal efficacy: practical aspects and challenges.

    PubMed

    Lai, J; Maibach, H I

    2009-01-01

    What are efficient screening models for improved topical antifungals? The use of minimum inhibitory concentrations (MICs) as one such parameter is discussed; we focus on the use of animal membranes for in vitro testing while highlighting the pros and cons of each model, exploring alternatives and discussing the importance of data transferability to humans and the influence of penetration kinetics in topical antifungal efficacy. Ultimately, the gold standard of testing is in vivo in humans; however, initiating with human testing, especially for novel topical antifungal agents, may be impractical, which is why we seek the ideal experimental model that most closely mimics human skin. We conclude that the pig may be an appropriate model membrane for topical antifungal testing based on its similarities in anatomical structure, physiology and permeation to human skin. Most importantly, pig and human skins appear equally permeable to several antifungals in prior in vitro and in vivo work. We do not discuss all prior work but highlight important issues in designing the protocol and parameters of the ideal experimental model for topical antifungals. PMID:19729988

  16. Isolation, characterization and antifungal docking studies of wortmannin isolated from Penicillium radicum

    PubMed Central

    Singh, Vineeta; Praveen, Vandana; Tripathi, Divya; Haque, Shafiul; Somvanshi, Pallavi; Katti, S. B.; Tripathi, C. K. M.

    2015-01-01

    During the search for a potent antifungal drug, a cell-permeable metabolite was isolated from a soil isolate taxonomically identified as Penicillium radicum. The strain was found to be a potent antifungal agent. Production conditions of the active compound were optimized and the active compound was isolated, purified, characterized and identified as a phosphoinositide 3-kinase (PI3K) inhibitor, commonly known as wortmannin (Wtmn). This is very first time we are reporting the production of Wtmn from P. radicum. In addition to its previously discovered anticancer properties, the broad spectrum antifungal property of Wtmn was re-confirmed using various fungal strains. Virtual screening was performed through molecular docking studies against potential antifungal targets, and it was found that Wtmn was predicted to impede the actions of these targets more efficiently than known antifungal compounds such as voriconazole and nikkomycin i.e. 1) mevalonate-5-diphosphate decarboxylase (1FI4), responsible for sterol/isoprenoid biosynthesis; 2) exocyst complex component SEC3 (3A58) where Rho- and phosphoinositide-dependent localization is present and 3) Kre2p/Mnt1p a Golgi alpha1,2-mannosyltransferase (1S4N) involved in the biosynthesis of yeast cell wall glycoproteins). We conclude that Wtmn produced from P. radicum is a promising lead compound which could be potentially used as an efficient antifungal drug in the near future after appropriate structural modifications to reduce toxicity and improve stability. PMID:26159770

  17. Antifungal stilbenoids from Stemona japonica.

    PubMed

    Zhang, Ya-Zhong; Xu, Guo-Bing; Zhang, Tong

    2008-01-01

    Three new dihydrostilbenes, stilbostemins P-R (1-3), and a new dihydrophenanthrene, stemanthrene G (4), were isolated from the roots of Stemona japonica together with three known bibenzyls, 3,5-dihydroxy-2'-methoxy bibenzyl (5), 3,3'-dihydroxy-2,5'-dimethoxy bibenzyl (6), and 3,5,2'-trihydroxy-4-methyl bibenzyl (7). Their structures were elucidated by spectroscopic analyses. Compounds 5 and 6 exhibited strong antifungal activities against Candida albicans. PMID:18636375

  18. Antibacterial and Antifungal Compounds from Marine Fungi

    PubMed Central

    Xu, Lijian; Meng, Wei; Cao, Cong; Wang, Jian; Shan, Wenjun; Wang, Qinggui

    2015-01-01

    This paper reviews 116 new compounds with antifungal or antibacterial activities as well as 169 other known antimicrobial compounds, with a specific focus on January 2010 through March 2015. Furthermore, the phylogeny of the fungi producing these antibacterial or antifungal compounds was analyzed. The new methods used to isolate marine fungi that possess antibacterial or antifungal activities as well as the relationship between structure and activity are shown in this review. PMID:26042616

  19. Photodynamic fungicidal efficacy of hypericin and dimethyl methylene blue against azole-resistant Candida albicans strains.

    PubMed

    Paz-Cristobal, M P; Royo, D; Rezusta, A; Andrés-Ciriano, E; Alejandre, M C; Meis, J F; Revillo, M J; Aspiroz, C; Nonell, S; Gilaberte, Y

    2014-01-01

    Antimicrobial photodynamic therapy (aPDT) is an emerging alternative to treat infections based on the use of photosensitisers (PSs) and visible light. To investigate the fungicidal effect of PDT against azole-resistant Candida albicans strains using two PSs with a different mechanism of action, hypericin (HYP) and 1,9-dimethyl methylene blue (DMMB), comparing their efficacy and the reactive oxygen species (ROS) species involved in their cytotoxicity. Azole-resistant and the azole-susceptible C. albicans strains were used. Solutions of 0.5 and 4 McFarland inoculum of each Candida strain were treated with different concentrations of each PS, and exposed to two light-emitting diode light fluences (18 and 37 J cm⁻²). Mechanistic insight was gained using several ROS quenchers. The minimal fungicidal concentration of HYP for ≥3 log₁₀ CFU reduction (0.5 McFarland) was 0.62 μmol l⁻¹ for most strains, whereas for DMMB it ranged between 1.25 and 2.5 μmol l⁻¹. Increasing the fluence to 37 J cm⁻² allowed to reduce the DMMB concentration. Higher concentrations of both PSs were required to reach a 6 log₁₀ reduction (4 McFarland). H₂O₂ was the main phototoxic species involved in the fungicidal effect of HYP-aPDT whereas ¹O₂ was more important for DMMB-based treatments. aPDT with either HYP or DMMB is effective in killing of C. albicans strains independent of their azole resistance pattern. HYP was more efficient at low fungal concentration and DMMB at higher concentrations. PMID:23905682

  20. In vitro antifungal susceptibility testing of Scopulariopsis brevicaulis strains using agar diffusion method.

    PubMed

    Skóra, Magdalena; Macura, Anna B

    2011-01-01

    The genus Scopulariopsis is a common soil saprotroph and has been isolated from air, organic waste and also from plant, animal and human tissues. Scopulariopsis has mainly been associated in humans with superficial mycoses, but it has also been described as the cause of subcutaneous and invasive infections. The most common aetiological agent of infections in humans is Scopulariopsis brevicaulis. This species has been reported to be resistant in vitro to broad-spectrum antifungal agents available today. The aim of the study was to establish in vitro antifungal susceptibility of 35 S. brevicaulis strains against amphotericin B (AMB), flucytosine (FC), caspofungin (CAS), terbinafine (TER), ciclopirox (CIC), voriconazole (VOR), clotrimazole (CTR), miconazole (MCZ), econazole (ECO), ketoconazole (KET), itraconazole (ITR), and fluconazole (FLU). Antifungal susceptibility tests were evaluated by an agar diffusion method (Neo-Sensitabs, Rosco, Denmark). AMB, FC, CAS, ITR and FLU showed no antifungal activity against S. brevicaulis. TER, CIC, CTR, KET, VOR, ECO, and MCZ revealed inhibitory activity for S. brevicaulis, but it varied for each of the drugs. The best antifungal effect was observed for TER and CIC. All isolates had large inhibition zones for TER and CIC. CTR was also inhibitory for all tested S. brevicaulis isolates, but the diameters of inhibition zones were smaller than for TER and CIC. Nearly 89% isolates showed inhibition zones for KET and the mean diameter of the inhibition zone was comparable to CTR. The least antifungal activity exhibited VQR, ECO and MCZ. Because of the multiresistance of S. brevicaulis, infections due to this species may not respond to particular antifungal treatment and other therapeutic approaches should be considered, e.g., combined therapy and/or surgery. PMID:21682097

  1. Mechanisms of Resistance to an Azole Fungicide in the Grapevine Powdery Mildew Fungus, Erysiphe necator.

    PubMed

    Frenkel, Omer; Cadle-Davidson, Lance; Wilcox, Wayne F; Milgroom, Michael G

    2015-03-01

    We studied the mechanisms of azole resistance in Erysiphe necator by quantifying the sensitivity to myclobutanil (EC50) in 65 isolates from the eastern United States and 12 from Chile. From each isolate, we sequenced the gene for sterol 14α-demethylase (CYP51), and measured the expression of CYP51 and homologs of four putative efflux transporter genes, which we identified in the E. necator transcriptome. Sequence variation in CYP51 was relatively low, with sequences of 40 U.S. isolates identical to the reference sequence. Nine U.S. isolates and five from Chile carried a previously identified A to T nucleotide substitution in position 495 (A495T), which results in an amino acid substitution in codon 136 (Y136F) and correlates with high levels of azole resistance. We also found a nucleotide substitution in position 1119 (A1119C) in 15 U.S. isolates, whose mean EC50 value was equivalent to that for the Y136F isolates. Isolates carrying mutation A1119C had significantly greater CYP51 expression, even though A1119C does not affect the CYP51 amino acid sequence. Regression analysis showed no significant effects of the expression of efflux transporter genes on EC50. Both the Y136F mutation in CYP51 and increased CYP51 expression appear responsible for azole resistance in eastern U.S. populations of E. necator. PMID:25271353

  2. Chemical Composition and Antifungal Activity of Angelica sinensis Essential Oil Against Three Colletotrichum Species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chemical fungicides are an important component in disease management for most crops. As part of a program to discover natural product-based fungicides, several sensitive assay systems have been developed for the evaluation of naturally occurring antifungal agents. In this study, we focused on the di...

  3. Clinically relevant drug-drug interactions between antiretrovirals and antifungals

    PubMed Central

    Vadlapatla, Ramya Krishna; Patel, Mitesh; Paturi, Durga K; Pal, Dhananjay; Mitra, Ashim K

    2015-01-01

    Introduction Complete delineation of the HIV-1 life cycle has resulted in the development of several antiretroviral drugs. Twenty-five therapeutic agents belonging to five different classes are currently available for the treatment of HIV-1 infections. Advent of triple combination antiretroviral therapy has significantly lowered the mortality rate in HIV patients. However, fungal infections still represent major opportunistic diseases in immunocompromised patients worldwide. Areas covered Antiretroviral drugs that target enzymes and/or proteins indispensable for viral replication are discussed in this article. Fungal infections, causative organisms, epidemiology and preferred treatment modalities are also outlined. Finally, observed/predicted drug-drug interactions between antiretrovirals and antifungals are summarized along with clinical recommendations. Expert opinion Concomitant use of amphotericin B and tenofovir must be closely monitored for renal functioning. Due to relatively weak interactive potential with the CYP450 system, fluconazole is the preferred antifungal drug. High itraconazole doses (> 200 mg/day) are not advised in patients receiving booster protease inhibitor (PI) regimen. Posaconazole is contraindicated in combination with either efavirenz or fosamprenavir. Moreover, voriconazole is contraindicated with high-dose ritonavir-boosted PI. Echino-candins may aid in overcoming the limitations of existing antifungal therapy. An increasing number of documented or predicted drug-drug interactions and therapeutic drug monitoring may aid in the management of HIV-associated opportunistic fungal infections. PMID:24521092

  4. Antifungal activity of topical microemulsion containing a thiophene derivative

    PubMed Central

    Guimarães, Geovani Pereira; de Freitas Araújo Reis, Mysrayn Yargo; da Silva, Dayanne Tomaz Casimiro; Junior, Francisco Jaime Bezerra Mendonça; Converti, Attílio; Pessoa, Adalberto; de Lima Damasceno, Bolívar Ponciano Goulart; da Silva, José Alexsandro

    2014-01-01

    Fungal infections have become a major problem of worldwide concern. Yeasts belonging to the Candida genus and the pathogenic fungus Cryptococcus neoformans are responsible for different clinical manifestations, especially in immunocompromised patients. Antifungal therapies are currently based on a few chemotherapeutic agents that have problems related to effectiveness and resistance profiles. Microemulsions are isotropic, thermodynamically stable transparent systems of oil, water and surfactant that can improve the solubilization of lipophilic drugs. Taking into account the need for more effective and less toxic drugs along with the potential of thiophene derivatives as inhibitors of pathogenic fungi growth, this study aimed to evaluate the antifungal activity of a thiophene derivative (5CN05) embedded in a microemulsion (ME). The minimum inhibitory concentration (MIC) was determined using the microdilution method using amphotericin B as a control. The formulations tested (ME- blank and ME-5CN05) showed physico-chemical properties that would allow their use by the topical route. 5CN05 as such exhibited moderate or weak antifungal activity against Candida species (MIC = 270–540 μg.mL−1) and good activity against C. neoformans (MIC = 17 μg.mL−1). Candida species were susceptible to ME-5CN05 (70–140 μg.mL−1), but C. neoformans was much more, presenting a MIC value of 2.2 μg.mL−1. The results of this work proved promising for the pharmaceutical industry, because they suggest an alternative therapy against C. neoformans. PMID:25242940

  5. Antifungal activity of gold nanoparticles prepared by solvothermal method

    SciTech Connect

    Ahmad, Tokeer; Wani, Irshad A.; Lone, Irfan H.; Ganguly, Aparna; Manzoor, Nikhat; Ahmad, Aijaz; Ahmed, Jahangeer; Al-Shihri, Ayed S.

    2013-01-15

    Graphical abstract: Gold nanoparticles (7 and 15 nm) of very high surface area (329 and 269 m{sup 2}/g) have been successfully synthesized through solvothermal method by using tin chloride and sodium borohydride as reducing agents. As-prepared gold nanoparticles shows very excellent antifungal activity against Candida isolates and activity increases with decrease in the particle size. Display Omitted Highlights: ► Effect of reducing agents on the morphology of gold nanoparticles. ► Highly uniform and monodisperse gold nanoparticles (7 nm). ► Highest surface area of gold nanoparticles (329 m{sup 2/}g). ► Excellent antifungal activity of gold nanoparticles against Candida strains. -- Abstract: Gold nanoparticles have been successfully synthesized by solvothermal method using SnCl{sub 2} and NaBH{sub 4} as reducing agents. X-ray diffraction studies show highly crystalline and monophasic nature of the gold nanoparticles with face centred cubic structure. The transmission electron microscopic studies show the formation of nearly spherical gold nanoparticles of average size of 15 nm using SnCl{sub 2}, however, NaBH{sub 4} produced highly uniform, monodispersed and spherical gold nanoparticles of average grain size of 7 nm. A high surface area of 329 m{sup 2}/g for 7 nm and 269 m{sup 2}/g for 15 nm gold nanoparticles was observed. UV–vis studies assert the excitations over the visible region due to transverse and longitudinal surface plasmon modes. The gold nanoparticles exhibit excellent size dependant antifungal activity and greater biocidal action against Candida isolates for 7 nm sized gold nanoparticles restricting the transmembrane H{sup +} efflux of the Candida species than 15 nm sized gold nanoparticles.

  6. Polyglycolic acid microneedles modified with inkjet-deposited antifungal coatings.

    PubMed

    Boehm, Ryan D; Daniels, Justin; Stafslien, Shane; Nasir, Adnan; Lefebvre, Joe; Narayan, Roger J

    2015-01-01

    In this study, the authors examined use of piezoelectric inkjet printing to apply an antifungal agent, voriconazole, to the surfaces of biodegradable polyglycolic acid microneedles. Polyglycolic acid microneedles with sharp tips (average tip radius = 25 ± 3 μm) were prepared using a combination of injection molding and drawing lithography. The elastic modulus (9.9 ± 0.3 GPa) and hardness (588.2 ± 33.8 MPa) values of the polyglycolic acid material were determined using nanoindentation and were found to be suitable for use in transdermal drug delivery devices. Voriconazole was deposited onto the polyglycolic acid microneedles by means of piezoelectric inkjet printing. It should be noted that voriconazole has poor solubility in water; however, it is readily soluble in many organic solvents. Optical imaging, scanning electron microscopy, energy dispersive x-ray spectrometry, and Fourier transform infrared spectroscopy were utilized to examine the microneedle geometries and inkjet-deposited surface coatings. Furthermore, an in vitro agar plating study was performed on the unmodified, vehicle-modified, and voriconazole-modified microneedles. Unlike the unmodified and vehicle-modified microneedles, the voriconazole-modified microneedles showed antifungal activity against Candida albicans. The unmodified, vehicle-modified, and voriconazole-modified microneedles did not show activity against Escherichia coli, Pseudomonas aeruginosa, or Staphylococcus aureus. The results indicate that piezoelectric inkjet printing may be useful for loading transdermal drug delivery devices such as polyglycolic acid microneedles with antifungal pharmacologic agents and other pharmacologic agents with poor solubility in aqueous solutions. PMID:25732934

  7. Azole-resistant Aspergillus fumigatus in Denmark: a laboratory-based study on resistance mechanisms and genotypes.

    PubMed

    Jensen, R H; Hagen, F; Astvad, K M T; Tyron, A; Meis, J F; Arendrup, M C

    2016-06-01

    Azole-resistant Aspergillus fumigatus originating from the environment as well as induced during therapy are continuously emerging in Danish clinical settings. We performed a laboratory-based retrospective study (2010-2014) of azole resistance and genetic relationship of A. fumigatus at the national mycology reference laboratory of Denmark. A total of 1162 clinical and 133 environmental A. fumigatus isolates were identified by morphology, thermotolerance and/or β-tubulin sequencing. Screening for azole resistance was carried out using azole agar, and resistant isolates were susceptibility tested by the EUCAST (European Committee on Antimicrobial Susceptibility Testing) E.Def 9.2 reference method and CYP51A sequenced. Genotyping was performed for outbreak investigation and, when appropriate, short tandem repeat Aspergillus fumigatus microsatellite assay. All 133 environmental A. fumigatus isolates were azole susceptible. However, from 2010 to 2014, there was an increasing prevalence of azole resistance (from 1.4 to 6% isolates (p <0.001) and 1.8 to 4% patients (p <0.05)) among the clinical isolates, with the well-known environmental CYP51A variant TR34/L98H responsible for >50% of the azole resistance mechanisms. Among 184 Danish A. fumigatus isolates, 120 unique genotypes were identified and compared to a collection of 1822 international genotypes. Seven (5.8%) Danish genotypes were shared between isolates within Denmark but with different origin, 19 (15.8%) were shared with foreign genotypes, and two (11.8%) of 17 genotypes of isolates carrying the TR34/L98H resistance mechanisms were identical to two Dutch TR34/L98H isolates. Our findings underlines the demand for correct identification and susceptibility testing of clinical mould isolates. Furthermore, although complex, genotyping supported the hypotheses regarding clonal expansion and the potential of a single origin for the TR34/L98H clone. PMID:27091095

  8. Antifungal Activity of Ellagic Acid In Vitro and In Vivo.

    PubMed

    Li, Zhi-Jian; Guo, Xin; Dawuti, Gulina; Aibai, Silafu

    2015-07-01

    Ellagic acid (EA) has been shown to have antioxidant, antibacterial, and anti-inflammatory activities. In Uighur traditional medicine, Euphorbia humifusa Willd is used to treat fungal diseases, and recent studies suggest that it is the EA content which is responsible for its therapeutic effect. However, the effects of EA on antifungal activity have not yet been reported. This study aimed to investigate the inhibitory effect of EA on fungal strains both in vitro and in vivo. The minimal inhibitory concentration (MIC) was determined by the National Committee for Clinical Laboratory Standards (M38-A and M27-A2) standard method in vitro. EA had a broad spectrum of antifungal activity, with MICs for all the tested dermatophyte strains between 18.75 and 58.33 µg/ml. EA was also active against two Candida strains, with MICs between 25.0 and 75.0 µg/ml. It was inactive against Candida glabrata. The susceptibility of six species of dermatophytes to EA was comparable with that of the commercial antifungal, fluconazole. The most sensitive filamentous species was Trichophyton rubrum (MIC = 18.75 µg/ml). Studies on the mechanism of action using an HPLC-based assay and an enzyme linked immunosorbent assay showed that EA inhibited ergosterol biosynthesis and reduced the activity of sterol 14α-demethylase P450 (CYP51) in the Trichophyton rubrum membrane, respectively. An in vivo test demonstrated that topical administration of EA (4.0 and 8.0 mg/cm(2) ) significantly enhanced the cure rate in a guinea-pig infection model of Trichophyton rubrum. The results suggest that EA has the potential to be developed as a natural antifungal agent. PMID:25919446

  9. Prevalence and antifungal susceptibility of Candida albicans and its related species Candida dubliniensis and Candida africana isolated from vulvovaginal samples in a hospital of Argentina.

    PubMed

    Theill, Laura; Dudiuk, Catiana; Morano, Susana; Gamarra, Soledad; Nardin, María Elena; Méndez, Emilce; Garcia-Effron, Guillermo

    2016-01-01

    Candida africana taxonomical status is controversial. It was proposed as a separate species within the Candida albicans species complex; however, phylogenetic analyses suggested that it is an unusual variety of C. albicans. The prevalence of C. albicans-related species (Candida dubliniensis and C. africana) as vulvovaginal pathogens is not known in Argentina. Moreover, data on antifungal susceptibility of isolates causing vulvovaginal candidiasis is scarce. The aims of this study were to establish the prevalence of C. dubliniensis and C. africana in vaginal samples and to evaluate the antifungal susceptibilities of vaginal C. albicans species complex strains. We used a molecular-based method coupled with a new pooled DNA extraction methodology to differentiate C. dubliniensis and C. africana in a collection of 287 strains originally identified as C. albicans isolated from an Argentinian hospital during 2013. Antifungal susceptibilities to fluconazole, clotrimazole, itraconazole, voriconazole, nystatin, amphotericin B and terbinafine were evaluated by using the CLSI M27-A3 and M27-S4 documents. Of the 287 isolates, 4 C. dubliniensis and one C. africana strains (1.39% and 0.35% prevalence, respectively) were identified. This is the first description of C. africana in Argentina and its identification was confirmed by sequencing the ITS2 region and the hwp1 gene. C. dubliniensis and C. africana strains showed very low MIC values for all the tested antifungals. Fluconazole-reduced-susceptibility and azole cross-resistance were observed in 3.55% and 1.41% of the C. albicans isolates, respectively. These results demonstrate that antifungal resistance is still a rare phenomenon in this kind of isolates. PMID:26922471

  10. Antifungals: Mechanism of Action and Drug Resistance.

    PubMed

    Prasad, Rajendra; Shah, Abdul Haseeb; Rawal, Manpreet Kaur

    2016-01-01

    There are currently few antifungals in use which show efficacy against fungal diseases. These antifungals mostly target specific components of fungal plasma membrane or its biosynthetic pathways. However, more recent class of antifungals in use is echinocandins which target the fungal cell wall components. The availability of mostly fungistatic antifungals in clinical use, often led to the development of tolerance to these very drugs by the pathogenic fungal species. Thus, the development of clinical multidrug resistance (MDR) leads to higher tolerance to drugs and its emergence is helped by multiple mechanisms. MDR is indeed a multifactorial phenomenon wherein a resistant organism possesses several mechanisms which contribute to display reduced susceptibility to not only single drug in use but also show collateral resistance to several drugs. Considering the limited availability of antifungals in use and the emergence of MDR in fungal infections, there is a continuous need for the development of novel broad spectrum antifungal drugs with better efficacy. Here, we briefly present an overview of the current understanding of the antifungal drugs in use, their mechanism of action and the emerging possible novel antifungal drugs with great promise. PMID:26721281

  11. Antifungal drug itraconazole targets VDAC1 to modulate the AMPK/mTOR signaling axis in endothelial cells

    PubMed Central

    Head, Sarah A.; Shi, Wei; Zhao, Liang; Gorshkov, Kirill; Pasunooti, Kalyan; Chen, Yue; Deng, Zhiyou; Li, Ruo-jing; Shim, Joong Sup; Tan, Wenzhi; Hartung, Thomas; Zhang, Jin; Zhao, Yingming; Colombini, Marco; Liu, Jun O.

    2015-01-01

    Itraconazole, a clinically used antifungal drug, was found to possess potent antiangiogenic and anticancer activity that is unique among the azole antifungals. Previous mechanistic studies have shown that itraconazole inhibits the mechanistic target of rapamycin (mTOR) signaling pathway, which is known to be a critical regulator of endothelial cell function and angiogenesis. However, the molecular target of itraconazole that mediates this activity has remained unknown. Here we identify the major target of itraconazole in endothelial cells as the mitochondrial protein voltage-dependent anion channel 1 (VDAC1), which regulates mitochondrial metabolism by controlling the passage of ions and small metabolites through the outer mitochondrial membrane. VDAC1 knockdown profoundly inhibits mTOR activity and cell proliferation in human umbilical vein cells (HUVEC), uncovering a previously unknown connection between VDAC1 and mTOR. Inhibition of VDAC1 by itraconazole disrupts mitochondrial metabolism, leading to an increase in the cellular AMP:ATP ratio and activation of the AMP-activated protein kinase (AMPK), an upstream regulator of mTOR. VDAC1-knockout cells are resistant to AMPK activation and mTOR inhibition by itraconazole, demonstrating that VDAC1 is the mediator of this activity. In addition, another known VDAC-targeting compound, erastin, also activates AMPK and inhibits mTOR and proliferation in HUVEC. VDAC1 thus represents a novel upstream regulator of mTOR signaling in endothelial cells and a promising target for the development of angiogenesis inhibitors. PMID:26655341

  12. Thiourea derivatives incorporating a hippuric acid moiety: synthesis and evaluation of antibacterial and antifungal activities.

    PubMed

    Abbas, Samir Y; El-Sharief, Marwa A M Sh; Basyouni, Wahid M; Fakhr, Issa M I; El-Gammal, Eman W

    2013-06-01

    New series of thiourea derivatives incorporating a hippuric acid moiety have been synthesized through the reaction of 4-hippuric acid isothiocyanate with various nitrogen nucleophiles such as aliphatic amines, aromatic amines, sulfa drugs, aminopyrazoles, phenylhydrazine and hydrazides. The synthesized compounds were tested against bacterial and fungal strains. Most of compounds, such as 2-(4-(3-(3-bromophenyl)thioureido)benzamido)acetic acid and 2-(4-(3-(4-(N-pyrimidin-2-ylsulfamoyl)phenyl)thioureido)benzamido)acetic acid, showed significant antibacterial and antifungal activities. These compounds comprise a new class of promising broad-spectrum antibacterial and antifungal agents. PMID:23644194

  13. Determination of azoles in sewage sludge from Spanish wastewater treatment plants by liquid chromatography-tandem mass spectrometry.

    PubMed

    García-Valcárcel, Ana I; Tadeo, José L

    2011-06-01

    A simple and rapid analytical method for the determination of 16 azoles in sewage sludge has been developed and validated. The method was based on ultrasound-assisted extraction followed by dispersive solid-phase extraction cleanup and liquid chromatography-electrospray tandem mass spectrometric detection. The azoles were selected by their intensive usage as biocides (tebuconazole, propiconazole, cyproconazole and thiabendazole), antimycotic pharmaceuticals (ketoconazole, econazole, fluconazole and clotrimazole) or fungicides in agriculture (difenoconazole, flusilazole, hexaconazole, prochloraz, bromuconazole, epoxiconazole and triticonazole). The recoveries of these compounds through the method were between 71.9 and 115.8%, with relative standard deviations lower than 20%. Detection limits were in the range of 0.5-5.0 ng/g. The developed method was applied to the analysis of azoles in sewage sludge samples collected from 19 Spanish wastewater treatment plants. Although azoles used as biocides or agriculture fungicides were present in a few sludge samples, the pharmaceuticals ketoconazole, econazole and clotrimazole were present in all of the analyzed sludge samples, being ketoconazole the one found at the highest level, representing the 68.6% of the total azole content found in the 19 sludge samples studied. PMID:21491590

  14. Iron-catalyzed N-alkylation of azoles via cleavage of an sp3 C-H bond adjacent to a nitrogen atom.

    PubMed

    Xia, Qinqin; Chen, Wanzhi

    2012-10-19

    Iron-catalyzed direct C-N bond formation between azoles and amides is described. The oxidative coupling reactions of sp(3) C-H bonds adjacent to a nitrogen atom in amides and sulfonamides with the N-H bond in azoles proceeded smoothly in the presence of FeCl(2) and di-tert-butyl peroxide (DTBP). PMID:23025235

  15. Gain-of-function mutations in UPC2 are a frequent cause of ERG11 upregulation in azole-resistant clinical isolates of Candida albicans.

    PubMed

    Flowers, Stephanie A; Barker, Katherine S; Berkow, Elizabeth L; Toner, Geoffrey; Chadwick, Sean G; Gygax, Scott E; Morschhäuser, Joachim; Rogers, P David

    2012-10-01

    In Candida albicans, Upc2 is a zinc-cluster transcription factor that targets genes, including those of the ergosterol biosynthesis pathway. To date, three documented UPC2 gain-of-function (GOF) mutations have been recovered from fluconazole-resistant clinical isolates that contribute to an increase in ERG11 expression and decreased fluconazole susceptibility. In a group of 63 isolates with reduced susceptibility to fluconazole, we found that 47 overexpressed ERG11 by at least 2-fold over the average expression levels in 3 unrelated fluconazole-susceptible strains. Of those 47 isolates, 29 contained a mutation in UPC2, whereas the remaining 18 isolates did not. Among the isolates containing mutations in UPC2, we recovered eight distinct mutations resulting in putative single amino acid substitutions: G648D, G648S, A643T, A643V, Y642F, G304R, A646V, and W478C. Seven of these resulted in increased ERG11 expression, increased cellular ergosterol, and decreased susceptibility to fluconazole compared to the results for the wild-type strain. Genome-wide transcriptional analysis was performed for the four strongest Upc2 amino acid substitutions (A643V, G648D, G648S, and Y642F). Genes commonly upregulated by all four mutations included those involved in ergosterol biosynthesis, in oxidoreductase activity, the major facilitator efflux pump encoded by the MDR1 gene, and the uncharacterized ATP binding cassette transporter CDR11. These findings demonstrate that gain-of-function mutations in UPC2 are more prevalent among clinical isolates than previously thought and make a significant contribution to azole antifungal resistance, but the findings do not account for ERG11 overexpression in all such isolates of C. albicans. PMID:22923048

  16. Active packaging with antifungal activities.

    PubMed

    Nguyen Van Long, N; Joly, Catherine; Dantigny, Philippe

    2016-03-01

    There have been many reviews concerned with antimicrobial food packaging, and with the use of antifungal compounds, but none provided an exhaustive picture of the applications of active packaging to control fungal spoilage. Very recently, many studies have been done in these fields, therefore it is timely to review this topic. This article examines the effects of essential oils, preservatives, natural products, chemical fungicides, nanoparticles coated to different films, and chitosan in vitro on the growth of moulds, but also in vivo on the mould free shelf-life of bread, cheese, and fresh fruits and vegetables. A short section is also dedicated to yeasts. All the applications are described from a microbiological point of view, and these were sorted depending on the name of the species. Methods and results obtained are discussed. Essential oils and preservatives were ranked by increased efficacy on mould growth. For all the tested molecules, Penicillium species were shown more sensitive than Aspergillus species. However, comparison between the results was difficult because it appeared that the efficiency of active packaging depended greatly on the environmental factors of food such as water activity, pH, temperature, NaCl concentration, the nature, the size, and the mode of application of the films, in addition to the fact that the amount of released antifungal compounds was not constant with time. PMID:26803804

  17. Synthesis, crystal structure and antifungal activity of a divalent cobalt(II) complex with uniconazole.

    PubMed

    Zhang, Yao; Li, Jie; Ren, Guoyu; Qin, Baofu; Ma, Haixia

    2016-06-01

    Azole compounds have attracted commercial interest due to their high bactericidal and plant-growth-regulating activities. Uniconazole [or 1-(4-chlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl)pent-1-en-3-ol] is a highly active 1,2,4-triazole fungicide and plant-growth regulator with low toxicity. The pharmacological and toxicological properties of many drugs are modified by the formation of their metal complexes. Therefore, there is much interest in exploiting the coordination chemistry of triazole pesticides and their potential application in agriculture. However, reports of complexes of uniconazole are rare. A new cobalt(II) complex of uniconazole, namely dichloridotetrakis[1-(4-chlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl-κN(4))pent-1-en-3-ol]cobalt(II), [CoCl2(C15H18ClN3O)4], was synthesized and structurally characterized by element analysis, IR spectrometry and X-ray single-crystal diffraction. The crystal structural analysis shows that the Co(II) atom is located on the inversion centre and is coordinated by four uniconazole and two chloride ligands, forming a distorted octahedral geometry. The hydroxy groups of an uniconazole ligands of adjacent molecules form hydrogen bonds with the axial chloride ligands, resulting in one-dimensional chains parallel to the a axis. The complex was analysed for its antifungal activity by the mycelial growth rate method. It was revealed that the antifungal effect of the title complex is more pronounced than the effect of fungicide uniconazole for Botryosphaeria ribis, Wheat gibberellic and Grape anthracnose. PMID:27256696

  18. Training should be the first step toward an antifungal stewardship program.

    PubMed

    Valerio, Maricela; Muñoz, Patricia; Rodríguez-González, Carmen; Sanjurjo, María; Guinea, Jesús; Bouza, Emilio

    2015-04-01

    The frequency of use of systemic antifungal agents has increased significantly in most tertiary centers. However, antifungal stewardship has received very little attention. The objective of this article was to assess the knowledge of prescribing physicians in our institution as a first step in the development of an antifungal stewardship program. Attending physicians from the departments that prescribe most antifungals were invited to complete a questionnaire based on current guidelines on diagnosis and therapy of invasive candidiasis and invasive aspergillosis (IA). The survey was completed by 60.8% (200/329) of the physicians who were invited to participate. The physicians belonged to the following departments: medical (60%), pediatric (19%), intensive care (15.5%), and surgical (5.5%). The mean (±SD) score of correct responses was 5.16±1.73. In the case of candidiasis, only 55% of the physicians clearly distinguished between colonization and infection, and 17.5% knew the local rate of fluconazole resistance. Thirty-three percent knew the accepted indications for antifungal prophylaxis, and 23% the indications for empirical therapy. However, most physicians knew which antifungals to choose when starting empirical therapy (73.5%). As for aspergillosis, most physicians (67%) could differentiate between colonization and infection, and 34.5% knew the diagnostic value of galactomannan. The radiological features of IA were well recognized by 64%, but only 31.5% were aware of the first line of treatment for IA, and 36% of the recommended duration of therapy. The usefulness of antifungal levels was known by 67%. This simple, easily completed questionnaire enabled us to identify which areas of our training strategy could be improved. PMID:25066382

  19. Antifungal Effects of Silver Nanoparticles (AgNPs) against Various Plant Pathogenic Fungi

    PubMed Central

    Kim, Sang Woo; Jung, Jin Hee; Lamsal, Kabir; Kim, Yun Seok; Min, Ji Seon

    2012-01-01

    This research is concerned with the fungicidal properties of nano-size silver colloidal solution used as an agent for antifungal treatment of various plant pathogens. We used WA-CV-WA13B, WA-AT-WB13R, and WA-PR-WB13R silver nanoparticles (AgNPs) at concentrations of 10, 25, 50, and 100 ppm. Eighteen different plant pathogenic fungi were treated with these AgNPs on potato dextrose agar (PDA), malt extract agar, and corn meal agar plates. We calculated fungal inhibition in order to evaluate the antifungal efficacy of silver nanoparticles against pathogens. The results indicated that AgNPs possess antifungal properties against these plant pathogens at various levels. Treatment with WA-CV-WB13R AgNPs resulted in maximum inhibition of most fungi. Results also showed that the most significant inhibition of plant pathogenic fungi was observed on PDA and 100 ppm of AgNPs. PMID:22783135

  20. A simple and convenient synthesis of 3'-5'- or 2'-5'-linked oligoribonucleotide by polymerization of unprotected ribonucleoside using phosphorus tris-azole.

    PubMed Central

    Shimidzu, T; Yamana, K; Kanda, N; Maikuma, S

    1984-01-01

    Oligoribonucleotides have been synthesized directly from unprotected ribonucleosides by a chemical polymerization approach using phosphorus tris-azoles. The procedure involves two steps: (i) the reaction of unprotected ribonucleoside with phosphorus tris-azole and (ii) the in situ oxidation of the resulting phosphite with iodine and water. Several phosphorus tris-azoles were investigated for generating oligoribonucleotide chains. Phosphorus tris-azoles of which azoles are imidazole, 2-methylimidazole, and 2-ethyl-4-methylimidazole were found to be most effective. Uridine, adenosine, and cytidine oligonucleotides were obtained rapidly in high yields without any protection. The inter-ribonucleotidic linkage of the oligomers consists of 3'-5'- and 2'-5'-linkages. The linkage isomers were easily separated by a reverse phase column chromatography. The present approach provides a convenient and potentially useful method for preparing 3'-5'- or 2'-5'-linked oligoribonucleotides. PMID:6326056

  1. RP-HPLC-DAD analysis of phenolic compounds in pomace extracts from five grape cultivars: Evaluation of their antioxidant, antiradical and antifungal activities in orange and apple juices.

    PubMed

    Sagdic, Osman; Ozturk, Ismet; Ozkan, Gulcan; Yetim, Hasan; Ekici, Lutfiye; Yilmaz, Mustafa Tahsin

    2011-06-15

    Phenolic compounds, related to antioxidative and antifungal properties of ethanolic extracts from five commercial grape cultivars (three red and two white) grown in Turkey were determined. A reversed-phase high performance liquid chromatography (RP-HPLC) procedure was developed, and a total 18 different phenolic compounds were identified. Total phenolic contents of the extracts were determined using Folin-Ciocalteau method. Antioxidant activities of the extracts were evaluated by using DPPH radical scavenging and phosphomolybdenum methods. All extracts exhibited strong antioxidant and antiradical activity. Phenolic compounds and antioxidant activities of the extracts were variety dependent. Antifungal activities of the pomaces and extracts were screened by both in vitro agar-well diffusion assay and antifungal activity in apple and orange juices in situ using Zygosaccharomyces rouxii and Z. bailii. Antifungal activities revealed that the pomaces and extracts of Gamay and Kalecik karasi could be more effective antifungal agents than those of Emir, Narince and Okuzgozu grape cultivars. PMID:25213954

  2. Antifungal prophylaxis in lung transplantation--a world-wide survey.

    PubMed

    Neoh, C F; Snell, G I; Kotsimbos, T; Levvey, B; Morrissey, C O; Slavin, M A; Stewart, K; Kong, D C M

    2011-02-01

    While variations in antifungal prophylaxis have been previously reported in lung transplant (LTx) recipients, recent clinical practice is unknown. Our aim was to determine current antifungal prophylactic practice in LTx centers world-wide. One nominated LTx clinician from each active center was invited by e-mail to participate in a web-based survey between September 2009 and January 2010. Fifty-seven percent (58/102) responded. The majority of responses were from medical directors of LTx centers (72.4%), and from the United States (44.8%). Within the first 6 months post-LTx, most centers (58.6%) employed universal prophylaxis, with 97.1% targeting Aspergillus species. Voriconazole alone, and in combination with inhaled amphotericin B (AmB), were the preferred first-line agents. Intolerance to side effects of voriconazole (69.2%) was the main reason for switching to alternatives. Beyond 6 months post-LTx, most (51.8%) did not employ antifungal prophylaxis. Fifteen centers (26.0%) conducted routine antifungal therapeutic drug monitoring during prophylactic period. There are differences in strategies employed between U.S. and European centers. Most respondents indicated a need for antifungal prophylactic guidelines. In comparison to earlier findings, there was a major shift toward prophylaxis with voriconazole and an increased use of echinocandins, posaconazole and inhaled lipid formulation AmB. PMID:21272239

  3. Koningiopisins A-H, Polyketides with Synergistic Antifungal Activities from the Endophytic Fungus Trichoderma koningiopsis.

    PubMed

    Liu, Kai; Yang, Yabin; Miao, Cui-Ping; Zheng, You-Kun; Chen, Jin-Lian; Chen, You-Wei; Xu, Li-Hua; Guang, Hui-Lin; Ding, Zhong-Tao; Zhao, Li-Xing

    2016-03-01

    Eight new fungal polyketides named koningiopisins A-H (1-8) and four previously known polyketides (9-12) were isolated from the endophytic fungus Trichoderma koningiopsis YIM PH 30002. Their structures were elucidated using extensive spectral data interpretation, and their antifungal and synergistic activities were also evaluated. Koningiopisin C (3) exhibited in vitro antifungal activity against the phytopathogenic fungus Plectosphaerella cucumerina with an MIC of 16 µg/mL. Although the antifungal activities of single compounds were not obvious, a mixture of six compounds (4-9) exhibited potent synergistic antifungal activity against P. cucumerina with an MIC of 16 µg/mL, and the antifungal activity of the mixture of any two compounds with a 1:1 ratio was better than that observed from the individual compound. The synergistic biological activity of the metabolites in YIM PH 30002 demonstrates the significant ecological function of the endophyte for its host plant, and provides additional insight into the search for and development of agents for biological control. PMID:26692458

  4. INJECTABLE IN SITU CROSS-LINKING HYDROGELS FOR LOCAL ANTIFUNGAL THERAPY

    PubMed Central

    Hudson, Sarah; Langer, Robert; Fink, Gerald R.; Kohane, Daniel S.

    2009-01-01

    Invasive fungal infections can be devastating, particularly in immunocompromised patients, and difficult to treat with systemic drugs. Furthermore, systemic administration of those medications can have severe side effects. We have developed an injectable local antifungal treatment for direct administration into existing or potential sites of fungal infection. Amphotericin B (AmB), a hydrophobic, potent, and broad-spectrum antifungal agent, was rendered water-soluble by conjugation to a dextran-aldehyde polymer. The dextran-aldehyde-AmB conjugate retained antifungal efficacy against C. albicans. Mixing carboxymethylcellulose-hydrazide with dextran-aldehyde formed a gel that cross-linked in situ by formation of hydrazone bonds. The gel provided in vitro release of antifungal activity for 11 days, and contact with the gel killed Candida for three weeks. There was no apparent tissue toxicity in the murine peritoneum and the gel caused no adhesions. Gels produced by entrapment of a suspension of AmB in CMC-dextran without conjugation of drug to polymers did not release fungicidal activity, but did kill on contact. Injectable systems of these types, containing soluble or insoluble drug formulations, could be useful for treatment of local antifungal infections, with or without concurrent systemic therapy. PMID:19942285

  5. Comparison of in vitro antifungal activities of topical antimycotics launched in 1990s in Japan.

    PubMed

    Nimura, K; Niwano, Y; Ishiduka, S; Fukumoto, R

    2001-08-01

    In vitro anti-dermatophyte, anti-Candida albicans and anti-Malassezia furfur activities of amorolfine hydrochloride (AMF), terbinafine hydrochloride (TBF), butenafine hydrochloride (BTF), neticonazole hydrochloride (NCZ) and ketoconazole (KCZ), all of which were introduced for the treatment of dermatomycoses in the 1990s in Japan, were compared. Although all of the test drugs are classified as an ergosterol biosynthesis inhibitor, the antifungal properties were found to be different. TBF and BTF exerted extremely potent antifungal activity against Trichophyton spp. but not against C. albicans and M. furfur, whilst KCZ and NCZ showed potent antifungal activity against C. albicans and M. furfur rather than Trichophyton spp. AMF exhibited potent antifungal activity against all of the fungal species tested. Fungicidal activities of these antifungal agents against T. rubrum were determined by using neutral red staining. The fungicidal potentialities correlated with those obtained in the in vitro susceptibility test as determined by MICs against dermatophytes. TBF, BTF and AMF exerted more potent fungicidal action than NCZ and KCZ. PMID:11516941

  6. Novel, Synergistic Antifungal Combinations that Target Translation Fidelity

    PubMed Central

    Moreno-Martinez, Elena; Vallieres, Cindy; Holland, Sara L.; Avery, Simon V.

    2015-01-01

    There is an unmet need for new antifungal or fungicide treatments, as resistance to existing treatments grows. Combination treatments help to combat resistance. Here we develop a novel, effective target for combination antifungal therapy. Different aminoglycoside antibiotics combined with different sulphate-transport inhibitors produced strong, synergistic growth-inhibition of several fungi. Combinations decreased the respective MICs by ≥8-fold. Synergy was suppressed in yeast mutants resistant to effects of sulphate-mimetics (like chromate or molybdate) on sulphate transport. By different mechanisms, aminoglycosides and inhibition of sulphate transport cause errors in mRNA translation. The mistranslation rate was stimulated up to 10-fold when the agents were used in combination, consistent with this being the mode of synergistic action. A range of undesirable fungi were susceptible to synergistic inhibition by the combinations, including the human pathogens Candida albicans, C. glabrata and Cryptococcus neoformans, the food spoilage organism Zygosaccharomyces bailii and the phytopathogens Rhizoctonia solani and Zymoseptoria tritici. There was some specificity as certain fungi were unaffected. There was no synergy against bacterial or mammalian cells. The results indicate that translation fidelity is a promising new target for combinatorial treatment of undesirable fungi, the combinations requiring substantially decreased doses of active components compared to each agent alone. PMID:26573415

  7. Novel, Synergistic Antifungal Combinations that Target Translation Fidelity.

    PubMed

    Moreno-Martinez, Elena; Vallieres, Cindy; Holland, Sara L; Avery, Simon V

    2015-01-01

    There is an unmet need for new antifungal or fungicide treatments, as resistance to existing treatments grows. Combination treatments help to combat resistance. Here we develop a novel, effective target for combination antifungal therapy. Different aminoglycoside antibiotics combined with different sulphate-transport inhibitors produced strong, synergistic growth-inhibition of several fungi. Combinations decreased the respective MICs by ≥8-fold. Synergy was suppressed in yeast mutants resistant to effects of sulphate-mimetics (like chromate or molybdate) on sulphate transport. By different mechanisms, aminoglycosides and inhibition of sulphate transport cause errors in mRNA translation. The mistranslation rate was stimulated up to 10-fold when the agents were used in combination, consistent with this being the mode of synergistic action. A range of undesirable fungi were susceptible to synergistic inhibition by the combinations, including the human pathogens Candida albicans, C. glabrata and Cryptococcus neoformans, the food spoilage organism Zygosaccharomyces bailii and the phytopathogens Rhizoctonia solani and Zymoseptoria tritici. There was some specificity as certain fungi were unaffected. There was no synergy against bacterial or mammalian cells. The results indicate that translation fidelity is a promising new target for combinatorial treatment of undesirable fungi, the combinations requiring substantially decreased doses of active components compared to each agent alone. PMID:26573415

  8. Correlation between in vitro and in vivo antifungal activities in experimental fluconazole-resistant oropharyngeal and esophageal candidiasis.

    PubMed

    Walsh, T J; Gonzalez, C E; Piscitelli, S; Bacher, J D; Peter, J; Torres, R; Shetti, D; Katsov, V; Kligys, K; Lyman, C A

    2000-06-01

    Oropharyngeal and esophageal candidiasis (OPEC) is a frequent opportunistic mycosis in immunocompromised patients. Azole-resistant OPEC is a refractory form of this infection occurring particularly in human immunodeficiency virus (HIV)-infected patients. The procedures developed by the Antifungal Subcommittee of the National Committee for Clinical Laboratory Standards (NCCLS) are an important advance in standardization of in vitro antifungal susceptibility methodology. In order to further understand the relationship between NCCLS methodology and antifungal therapeutic response, we studied the potential correlation between in vitro susceptibility to fluconazole and in vivo response in a rabbit model of fluconazole-resistant OPEC. MICs of fluconazole were determined by NCCLS methods. Three fluconazole-susceptible (FS) (MIC, /=64 microgram/ml) isolates of Candida albicans from prospectively monitored HIV-infected children with OPEC were studied. FR isolates were recovered from children with severe OPEC refractory to fluconazole, and FS isolates were recovered from those with mucosal candidiasis responsive to fluconazole. Fluconazole at 2 mg/kg of body weight/day was administered to infected animals for 7 days. The concentrations of fluconazole in plasma were maintained above the MICs for FS isolates throughout the dosing interval. Fluconazole concentrations in the esophagus were greater than or equal to those in plasma. Rabbits infected with FS isolates and treated with fluconazole had significant reductions in oral mucosal quantitative cultures (P < 0.001) and tissue burden of C. albicans in tongue, soft palate, and esophagus (P < 0.001). In comparison, rabbits infected with FR isolates were unresponsive to fluconazole and had no reduction in oral mucosal quantitative cultures or tissue burden of C. albicans versus untreated controls. We conclude that there is a strong correlation between in vitro

  9. Azole Resistance in Aspergillus fumigatus Clinical Isolates from an Italian Culture Collection

    PubMed Central

    Lazzarini, Cristina; Esposto, Maria Carmela; Prigitano, Anna; Cogliati, Massimo; De Lorenzis, Gabriella

    2015-01-01

    The aims of the study were to investigate the prevalence of azole resistance among Aspergillus fumigatus clinical isolates. A total of 533 clinical isolates that had been collected between 1995 and 2006, from 441 patients, were screened. No resistance was detected in isolates collected between 1995 and 1997. Starting in 1998, the resistance rate was 6.9%; a total of 24 patients (6.25%) harbored a resistant isolate. The TR34/L98H substitution was found in 21 of 30 tested isolates. PMID:26552980

  10. Molecular Identification and Antifungal Susceptibility of Yeast Isolates Causing Fungemia Collected in a Population-Based Study in Spain in 2010 and 2011

    PubMed Central

    Guinea, Jesús; Zaragoza, Óscar; Escribano, Pilar; Martín-Mazuelos, Estrella; Pemán, Javier; Sánchez-Reus, Ferrán

    2014-01-01

    We report the molecular identifications and antifungal susceptibilities of the isolates causing fungemia collected in the CANDIPOP population-based study conducted in 29 Spanish hospitals. A total of 781 isolates (from 767 patients, 14 of them having mixed fungemia) were collected. The species found most frequently were Candida albicans (44.6%), Candida parapsilosis (24.5%), Candida glabrata (13.2%), Candida tropicalis (7.6%), Candida krusei (1.9%), Candida guilliermondii (1.7%), and Candida lusitaniae (1.3%). Other Candida and non-Candida species accounted for approximately 5% of the isolates. The presence of cryptic species was low. Compared to findings of previous studies conducted in Spain, the frequency of C. glabrata has increased. Antifungal susceptibility testing was performed by using EUCAST and CLSI M27-A3 reference procedures; the two methods were comparable. The rate of fluconazole-susceptible isolates was 80%, which appears to be a decrease compared to findings of previous studies, explained mainly by the higher frequency of C. glabrata. Using the species-specific breakpoints and epidemiological cutoff values, the rate of voriconazole and posaconazole in vitro resistance was low (<2%). In the case of C. tropicalis, using the EUCAST procedure, the rate of azole resistance was around 20%. There was a correlation between the previous use of azoles and the presence of fluconazole-resistant isolates. Resistance to echinocandins was very rare (2%), and resistance to amphotericin B also was very uncommon. The sequencing of the hot spot (HS) regions from FKS1 or FKS2 genes in echinocandin-resistant isolates revealed previously described point mutations. The decrease in the susceptibility to fluconazole in Spanish isolates should be closely monitored in future studies. PMID:24366741

  11. Antifungal proteins: More than antimicrobials?

    PubMed Central

    Hegedüs, Nikoletta; Marx, Florentine

    2013-01-01

    Antimicrobial proteins (AMPs) are widely distributed in nature. In higher eukaryotes, AMPs provide the host with an important defence mechanism against invading pathogens. AMPs of lower eukaryotes and prokaryotes may support successful competition for nutrients with other microorganisms of the same ecological niche. AMPs show a vast variety in structure, function, antimicrobial spectrum and mechanism of action. Most interestingly, there is growing evidence that AMPs also fulfil important biological functions other than antimicrobial activity. The present review focuses on the mechanistic function of small, cationic, cysteine-rich AMPs of mammals, insects, plants and fungi with antifungal activity and specifically aims at summarizing current knowledge concerning additional biological properties which opens novel aspects for their future use in medicine, agriculture and biotechnology. PMID:23412850

  12. Antifungal isopimaranes from Hypoestes serpens.

    PubMed

    Rasoamiaranjanahary, L; Guilet, D; Marston, A; Randimbivololona, F; Hostettmann, K

    2003-09-01

    Five isopimarane diterpenes (7beta-hydroxyisopimara-8,15-dien-14-one, 14alpha-hydroxyisopimara-7,15-dien-1-one, 1beta,14alpha-dihydroxyisopimara-7,15-diene, 7beta-hydroxyisopimara-8(14),15-dien-1-one and 7beta-acetoxyisopimara-8(14),15-dien-1-one) have been isolated from the leaves of Hypoestes serpens (Acanthaceae). All compounds exhibited antifungal activity against both the plant pathogenic fungus Cladosporium cucumerinum and the yeast Candida albicans; two of them also displayed an acetylcholinesterase inhibition. The structures of the compounds were determined by means of spectrometric methods, including 1D and 2D NMR experiments and MS analysis. PMID:12943772

  13. Isavuconazole: A New Broad-Spectrum Triazole Antifungal Agent.

    PubMed

    Miceli, Marisa H; Kauffman, Carol A

    2015-11-15

    Isavuconazole is a new extended-spectrum triazole with activity against yeasts, molds, and dimorphic fungi. It is approved for the treatment of invasive aspergillosis and mucormycosis. Advantages of this triazole include the availability of a water-soluble intravenous formulation, excellent bioavailability of the oral formulation, and predictable pharmacokinetics in adults. A randomized, double-blind comparison clinical trial for treatment of invasive aspergillosis found that the efficacy of isavuconazole was noninferior to that of voriconazole. An open-label trial that studied primary as well as salvage therapy of invasive mucormycosis showed efficacy with isavuconazole that was similar to that reported for amphotericin B and posaconazole. In patients in these studies, as well as in normal volunteers, isavuconazole was well tolerated, appeared to have few serious adverse effects, and had fewer drug-drug interactions than those noted with voriconazole. As clinical experience increases, the role of this new triazole in the treatment of invasive fungal infections will be better defined. PMID:26179012

  14. Research to Identify Effective Antifungal Agents, 1990 Annual Report.

    SciTech Connect

    Schreck, Carl

    1990-07-01

    The objectives of the present contract study were to select and evaluate up to 10 candidate fungicides. Evaluations of Goal 1 involve laboratory studies on efficacy of candidate compounds on cultured Saprolegniales, and on eggs of rainbow trout and chinook salmon that were previously infected with the fungus. The main objective this year of Goal 2 was to determine the degree of fungal infection in untreated, control fish to establish the extent of the problem.

  15. Early state research on antifungal natural products.

    PubMed

    Negri, Melyssa; Salci, Tânia P; Shinobu-Mesquita, Cristiane S; Capoci, Isis R G; Svidzinski, Terezinha I E; Kioshima, Erika Seki

    2014-01-01

    Nosocomial infections caused by fungi have increased greatly in recent years, mainly due to the rising number of immunocompromised patients. However, the available antifungal therapeutic arsenal is limited, and the development of new drugs has been slow. Therefore, the search for alternative drugs with low resistance rates and fewer side effects remains a major challenge. Plants produce a variety of medicinal components that can inhibit pathogen growth. Studies of plant species have been conducted to evaluate the characteristics of natural drug products, including their sustainability, affordability, and antimicrobial activity. A considerable number of studies of medicinal plants and alternative compounds, such as secondary metabolites, phenolic compounds, essential oils and extracts, have been performed. Thus, this review discusses the history of the antifungal arsenal, surveys natural products with potential antifungal activity, discusses strategies to develop derivatives of natural products, and presents perspectives on the development of novel antifungal drug candidates. PMID:24609016

  16. Infected nail plate model made of human hair keratin for evaluating the efficacy of different topical antifungal formulations against Trichophyton rubrum in vitro.

    PubMed

    Lusiana; Reichl, Stephan; Müller-Goymann, Christel C

    2013-08-01

    A novel model of infected nail plate for testing the efficacy of topical antifungal formulations has been developed. This model utilized keratin film made of human hair keratin as a nail plate model. Subsequent to infection by Trichophyton rubrum, the common causative agent of onychomycosis, keratin films as infected nail plate models were treated with selected topical formulations, that is cream, gel, and nail lacquer. Bovine hoof was compared to keratin film. In contrast to the common antifungal susceptibility test, the antifungal drugs tested were applied as ready-to-use formulations because the vehicle may modify and control the drug action both in vitro and in vivo. Extrapolating the potency of an antifungal drug from an in vitro susceptibility test only would not be representative of the in vivo situation since these drugs are applied as ready-to-use formulations, for example as a nail lacquer. Although terbinafine has been acknowledged to be the most effective antifungal agent against T. rubrum, its antifungal efficacy was improved by its incorporation into an optimal formulation. Different gels proved superior to cream. Therefore, this study is able to discriminate between efficacies of different topical antifungal formulations based on their activities against T. rubrum. PMID:23419812

  17. 3D-QSAR and molecular mechanics study for the differences in the azole activity against yeastlike and filamentous fungi and their relation to P450DM inhibition. 1. 3-substituted-4(3H)-quinazolinones.

    PubMed

    Fratev, Filip; Benfenati, Emilio

    2005-01-01

    A combination between 3D-QSAR and molecular mechanics (MM)-docking study was used as a tool to detail and model the mechanism of action of 46 antifungal azoles. Two methods of alignment of the ligands were performed: (i) alignment of the main skeleton without substituents and (ii) alignment of a defined substructure. The best model is characterized by q(2) with the values of 0.70 for yeastlike (yeast), 0.66 for filamentous fungi, and 0.70 for the selectivity against filamentous fungi. 3D-QSAR regression maps derived from six models were used to identify the regions responsible for the differences in the compounds activity against yeast and filamentous fungi. The binding energy of the important substructures (Local Binding Energy-LBE) and its standard deviation were calculated in order to demonstrate quantitatively the contribution of substituents reflecting the diversity of the antifungal activity. The comparisons of these results with the same regions of the contour maps indicated a good correspondence between the 3D-QSAR and MM (LBE) approaches allowing association between the maps and the participating residues in the active sites of P450DM of C. albicans and A. fumigatus. The pi-pi interactions of two or more aromatic groups of the ligands with Phe228 and Tyr132 prove to be most important for the differences in activity against C. albicans. In A. fumigatus there was a better occupation of the inner central I-spiral in the areas around the heme. For the activity against A. fumigatus the pi-pi interactions of aromatic groups of the compounds with Phe509, Phe228, and Tyr132 are significant for the activity. PMID:15921453

  18. Nonstoichiometric, Protic Azolium Azolate Ionic Liquids Provide Unique Environments for N-Donor Coordination Chemistry.

    PubMed

    Kelley, Steven P; Nuss, Joseph S; Rogers, Robin D

    2015-11-23

    Here we demonstrate that neat reactions of amphoteric azoles with more basic azoles give a family of finely tunable, nonstoichiometric liquids which are useful for N-donor coordination chemistry. Reacting 4,5-dicyanoimidazole (4,5-DCNIm) with 1-methylimidazole (1-mim) gives new compounds with composition-dependent speciation. Two crystalline compounds, a 1:1 protic salt, [H(1-mim)][4,5-DCNIm], and a 1:2 salt co-crystal, [H(1-mim)][4,5-DCNIm]⋅4,5-DCNIm, were isolated and structurally characterized, while differential scanning calorimetry revealed both suppression of crystallization and the presence of neutral and anionic species in the melt. Reactions of Cu(NO3 )2 ⋅2.5 H2 O, CuO, and ZnO with the neat 2:1 1-mim/4,5-DCNIm melt resulted in the isolation of entirely N-donor ligated complexes of the formula M(4,5-DCNIm)2 (1-mim)4 (M=Cu, Zn). PMID:26439450

  19. Antifungal clinical trials and guidelines: what we know and do not know.

    PubMed

    Pappas, Peter G

    2014-11-01

    For over the last three decades, extensive testing of antifungal compounds in clinical trials has been essential to the development of treatment guidelines for the most common invasi