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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: emphasis on new triazoles.

    PubMed Central

    Saag, M S; Dismukes, W E

    1988-01-01

    Many advances have been made in antifungal therapy over the last three decades. Itraconazole and fluconazole, two investigational triazole agents, are the most recent additions to the list of antifungal drugs. This review has focused primarily on their mechanisms of action, favorable pharmacologic properties, and spectra of activity against a broad range of systemic pathogens. Itraconazole and fluconazole show much promise as orally active agents, with less potential for toxicity than the currently available azoles. Fluconazole and, to a lesser degree, itraconazole are especially promising therapies for cryptococcal meningitis. In addition, fluconazole may prove to be highly effective in urinary tract infections caused by Candida species and other fungi. Ongoing and future clinical trials will more clearly define the specific roles of itraconazole and fluconazole in the treatment of systemic mycoses. PMID:2831809

  3. Management of drug and food interactions with azole antifungal agents in transplant recipients.

    PubMed

    Dodds-Ashley, Elizabeth

    2010-08-01

    Azole antifungal agents are frequently used in hematopoietic stem cell and solid organ transplant recipients for prevention or treatment of invasive fungal infections. However, because of metabolism by or substrate activity for various isoenzymes of the cytochrome P450 system and/or P-glycoprotein, azole antifungals have the potential to interact with many of the drugs commonly used in these patient populations. Thus, to identify drug interactions that may result between azole antifungals and other drugs, we conducted a literature search of the MEDLINE database (1966-December 2009) for English-language articles on drug interaction studies involving the azole antifungal agents fluconazole, itraconazole, voriconazole, and posaconazole. Another literature search between each of the azoles and the immunosuppressants cyclosporine, tacrolimus, and sirolimus, as well as the corticosteroids methylprednisolone, dexamethasone, prednisolone, and prednisone, was also conducted. Concomitant administration of azoles and immunosuppressive agents may cause clinically significant drug interactions resulting in extreme immunosuppression or toxicity. The magnitude and duration of an interaction between azoles and immunosuppressants are not class effects of the azoles, but differ between drug combinations and are subject to interpatient variability. Drug interactions in the transplant recipient receiving azole therapy may also occur with antibiotics, chemotherapeutic agents, and acid-suppressive therapies, among other drugs. Initiation of an azole antifungal in transplant recipients nearly ensures a drug-drug interaction, but often these drugs are required. Management of these interactions first involves knowledge of the potential drug interaction, appropriate dosage adjustments when necessary, and therapeutic or clinical monitoring at an appropriate point in therapy to assess the drug-drug interaction (e.g., immunosuppressive drug concentrations, signs and symptoms of toxicity

  4. Antifungal activities of azole agents against the Malassezia species.

    PubMed

    Miranda, Karla Carvalho; de Araujo, Crystiane Rodrigues; Costa, Carolina Rodrigues; Passos, Xisto Sena; de Fátima Lisboa Fernandes, Orionalda; do Rosário Rodrigues Silva, Maria

    2007-03-01

    In this paper, we identified 95 Malassezia isolates by morphological and biochemical criteria and assessed the in vitro activity of fluconazole, itraconazole, ketoconazole and voriconazole by broth microdilution against these species using slightly modified Leeming-Notman medium. The Malassezia isolates were identified as M. furfur (74), M. sympodialis (11), M. obtusa (8) and M. globosa (2). The modified Leeming-Notman medium used for susceptibility testing allowed good growth of Malassezia spp. Visual reading of the minimal inhibitory concentration (MIC) was readily achieved until Day 5 of incubation at 32 degrees C. Although high MIC values of 16 microg/mL for fluconazole were observed in 9.5% of Malassezia isolates, in general these microorganisms were susceptible to all drugs studied. Interestingly, one M. globosa isolate showed high MIC values for voriconazole, itraconazole and fluconazole. For the 95 strains, the MIC ranges were <0.03-4 microg/mL for ketoconazole, <0.03 to >16 microg/mL for voriconazole, <0.125 to >64 microg/mL for fluconazole and <0.03-16 microg/mL for itraconazole. In summary, the good reproducibility and visual readings obtained using modified Leeming-Notman medium suggest that this medium should be proposed for antifungal testing of drugs against Malassezia spp.

  5. Antifungal drug resistance to azoles and polyenes.

    PubMed

    Masiá Canuto, Mar; Gutiérrez Rodero, Félix

    2002-09-01

    There is an increased awareness of the morbidity and mortality associated with fungal infections caused by resistant fungi in various groups of patients. Epidemiological studies have identified risk factors associated with antifungal drug resistance. Selection pressure due to the continuous exposure to azoles seems to have an essential role in developing resistance to fluconazole in Candida species. Haematological malignancies, especially acute leukaemia with severe and prolonged neutropenia, seem to be the main risk factors for acquiring deep-seated mycosis caused by resistant filamentous fungi, such us Fusarium species, Scedosporium prolificans, and Aspergillus terreus. The still unacceptably high mortality rate associated with some resistant mycosis indicates that alternatives to existing therapeutic options are needed. Potential measures to overcome antifungal resistance ranges from the development of new drugs with better antifungal activity to improving current therapeutic strategies with the present antifungal agents. Among the new antifungal drugs, inhibitors of beta glucan synthesis and second-generation azole and triazole derivatives have characteristics that render them potentially suitable agents against some resistant fungi. Other strategies including the use of high doses of lipid formulations of amphotericin B, combination therapy, and adjunctive immune therapy with cytokines are under investigation. In addition, antifungal control programmes to prevent extensive and inappropriate use of antifungals may be needed.

  6. Amino Acid Substitutions in the Cytochrome P-450 Lanosterol 14α-Demethylase (CYP51A1) from Azole-Resistant Candida albicans Clinical Isolates Contribute to Resistance to Azole Antifungal Agents

    PubMed Central

    Sanglard, Dominique; Ischer, Françoise; Koymans, Luc; Bille, Jacques

    1998-01-01

    The cytochrome P-450 lanosterol 14α-demethylase (CYP51A1) of yeasts is involved in an important step in the biosynthesis of ergosterol. Since CYP51A1 is the target of azole antifungal agents, this enzyme is potentially prone to alterations leading to resistance to these agents. Among them, a decrease in the affinity of CYP51A1 for these agents is possible. We showed in a group of Candida albicans isolates from AIDS patients that multidrug efflux transporters were playing an important role in the resistance of C. albicans to azole antifungal agents, but without excluding the involvement of other factors (D. Sanglard, K. Kuchler, F. Ischer, J.-L. Pagani, M. Monod, and J. Bille, Antimicrob. Agents Chemother. 39:2378–2386, 1995). We therefore analyzed in closer detail changes in the affinity of CYP51A1 for azole antifungal agents. A strategy consisting of functional expression in Saccharomyces cerevisiae of the C. albicans CYP51A1 genes of sequential clinical isolates from patients was designed. This selection, which was coupled with a test of susceptibility to the azole derivatives fluconazole, ketoconazole, and itraconazole, enabled the detection of mutations in different cloned CYP51A1 genes, whose products are potentially affected in their affinity for azole derivatives. This selection enabled the detection of five different mutations in the cloned CYP51A1 genes which correlated with the occurrence of azole resistance in clinical C. albicans isolates. These mutations were as follows: replacement of the glycine at position 129 with alanine (G129A), Y132H, S405F, G464S, and R467K. While the S405F mutation was found as a single amino acid substitution in a CYP51A1 gene from an azole-resistant yeast, other mutations were found simultaneously in individual CYP51A1 genes, i.e., R467K with G464S, S405F with Y132H, G129A with G464S, and R467K with G464S and Y132H. Site-directed mutagenesis of a wild-type CYP51A1 gene was performed to estimate the effect of each of these

  7. 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

  8. Susceptibility of clinical isolates of Candida spp. to terconazole and other azole antifungal agents.

    PubMed

    Pfaller, M A; Gerarden, T

    1989-01-01

    Terconazole is a triazole ketal derivative with potent, broad-spectrum antifungal activity. We investigated the in vitro activity of terconazole, miconazole, and clotrimazole, against 94 clinical isolates of Candida spp.: C. albicans (n = 68), C. tropicalis (n = 18), and C. parapsilosis (n = 8). In vitro susceptibility testing was performed using a broth microdilution method. The minimal inhibitory concentrations of terconazole were less than those of miconazole against C. albicans and C. parapsilosis but higher against C. tropicalis. Terconazole was more active than clotrimazole against C. parapsilosis and less active against C. albicans and C. tropicalis. Terconazole inhibited the uptake of 14C-labeled glucose, leucine, and hypoxanthine into C. albicans and caused the rapid release of intracellular K+. Based on these studies, terconazole has promising anticandidal activity and warrants further in vitro and in vivo investigation.

  9. Stereoselective interaction of the azole antifungal agent SCH39304 with the cytochrome P-450 monooxygenase system isolated from Cryptococcus neoformans.

    PubMed Central

    Lamb, D C; Baldwin, B C; Kwon-Chung, K J; Kelly, S L

    1997-01-01

    We investigated the stereoselective inhibition of growth and ergosterol biosynthesis by SCH39304 in the pathogenic fungus Cryptococcus neoformans obtained from four AIDS patients who failed fluconazole therapy and compared the results to those obtained with a wild-type strain. For all strains, the MICs of the RR isomer were approximately half those of the racemate, with the SS enantiomer showing no inhibitory activity. The 50% inhibitory concentrations for in vitro ergosterol biosynthesis correlated with the MIC data, indicating stereoselective inhibition of their target P-450 enzyme, sterol 14alpha-demethylase, as the cause of this difference. The RR enantiomer produced classical type II spectra on addition to microsomal extracts of the strains, whereas the SS enantiomer showed an absence of binding. Stereo- and regio-specific localization of N-1 substituent groups of SCH39304 within the active site of the enzyme determined the unique discrimination between its two enantiomers, and the inability to bind to sterol 14alpha-demethylase is also true of other P-450 enzymes contained in the microsomal fraction. As previously observed for other antifungal azoles, isolates obtained following failure of fluconazole therapy showed resistance to SCH39304 and its RR enantiomer. This resistance could be associated with an alteration in the sensitivity of ergosterol biosynthesis in vitro. These alterations did not cause any changes allowing the SS enantiomer to bind to the P-450 mediating sterol 14alpha-demethylation. PMID:9210667

  10. Effects of terconazole and other azole antifungal agents on the sterol and carbohydrate composition of Candida albicans.

    PubMed

    Pfaller, M A; Riley, J; Koerner, T

    1990-01-01

    The effects of terconazole, a triazole antifungal, on the sterol and carbohydrate composition of Candida albicans was compared with that of three imidazoles: clotrimazole, miconazole, and butoconazole. Exposure of C. albicans to terconazole resulted in a profound depletion of ergosterol with a corresponding increase in lanosterol content versus control cells. Carbohydrate analysis revealed a significant (245%) increase in chitin and a minimal effect on glucan and mannan in terconazole-treated cells. Similar effects on sterol and carbohydrate composition were observed with clotrimazole and miconazole. Butoconazole had a similar effect on sterol composition but had no effect on carbohydrate composition. The decreased ergosterol and increased lanosterol content is consistent with 14 alpha-demethylase inhibition by terconazole and the other azoles. The increase in cell wall chitin is most likely due to deregulation of chitin synthesis secondary to ergosterol depletion in the cell membrane. Because both chitin and ergosterol are critical components of the fungal cell, perturbation of the production and localization of these components by terconazole is likely to contribute to the selective toxicity of this compound for C. albicans and other fungi.

  11. Biochemical approaches to selective antifungal activity. Focus on azole antifungals.

    PubMed

    Vanden Bossche, H; Marichal, P; Gorrens, J; Coene, M C; Willemsens, G; Bellens, D; Roels, I; Moereels, H; Janssen, P A

    1989-01-01

    Azole antifungals (e.g. the imidazoles: miconazole, clotrimazole, bifonazole, imazalil, ketoconazole, and the triazoles: diniconazole, triadimenol, propiconazole, fluconazole and itraconazole) inhibit in fungal cells the 14 alpha-demethylation of lanosterol or 24-methylenedihydrolanosterol. The consequent inhibition of ergosterol synthesis originates from binding of the unsubstituted nitrogen (N-3 or N-4) of their imidazole or triazole moiety to the heme iron and from binding of their N-1 substituent to the apoprotein of a cytochrome P-450 (P-450(14)DM) of the endoplasmic reticulum. Great differences in both potency and selectivity are found between the different azole antifungals. For example, after 16h of growth of Candida albicans in medium supplemented with [14C]-acetate and increasing concentrations of itraconazole, 100% inhibition of ergosterol synthesis is achieved at 3 x 10(-8) M. Complete inhibition of this synthesis by fluconazole is obtained at 10(-5) M only. The agrochemical imidazole derivative, imazalil, shows high selectivity, it has almost 80 and 98 times more affinity for the Candida P-450(s) than for those of the piglet testes microsomes and bovine adrenal mitochondria, respectively. However, the topically active imidazole antifungal, bifonazole, has the highest affinity for P-450(s) of the testicular microsomes. The triazole antifungal itraconazole inhibits at 10(-5) M the P-450-dependent aromatase by 17.9, whereas 50% inhibition of this enzyme is obtained at about 7.5 x 10(-6)M of the bistriazole derivative fluconazole. The overall results show that both the affinity for the fungal P-450(14)DM and the selectivity are determined by the nitrogen heterocycle and the hydrophobic N-1 substituent of the azole antifungals. The latter has certainly a greater impact. The presence of a triazole and a long hypdrophobic nonligating portion form the basis for itraconazole's potency and selectivity.

  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.

  13. 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

  14. 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.

  15. Azole Antifungal Resistance in Candida albicans and Emerging Non-albicans Candida Species

    PubMed Central

    Whaley, Sarah G.; Berkow, Elizabeth L.; Rybak, Jeffrey M.; Nishimoto, Andrew T.; Barker, Katherine S.; Rogers, P. David

    2017-01-01

    Within the limited antifungal armamentarium, the azole antifungals are the most frequent class used to treat Candida infections. Azole antifungals such as fluconazole are often preferred treatment for many Candida infections as they are inexpensive, exhibit limited toxicity, and are available for oral administration. There is, however, extensive documentation of intrinsic and developed resistance to azole antifungals among several Candida species. As the frequency of azole resistant Candida isolates in the clinical setting increases, it is essential to elucidate the mechanisms of such resistance in order to both preserve and improve upon the azole class of antifungals for the treatment of Candida infections. This review examines azole resistance in infections caused by C. albicans as well as the emerging non-albicans Candida species C. parapsilosis, C. tropicalis, C. krusei, and C. glabrata and in particular, describes the current understanding of molecular basis of azole resistance in these fungal species. PMID:28127295

  16. Optimizing azole antifungal therapy in the prophylaxis and treatment of fungal infections.

    PubMed

    Dolton, Michael J; McLachlan, Andrew J

    2014-12-01

    Azole antifungals are widely used in the prophylaxis and treatment of fungal infections, but are associated with a range of pharmacokinetic challenges and safety issues that necessitate individualized therapy to achieve optimal clinical outcomes. Recent advances in our knowledge of azole exposure-response relationships, therapeutic drug monitoring and individualized dosing strategies are reviewed as follows. Recent studies have significantly improved the understanding of exposure-response relationships for efficacy and toxicity, increasing confidence in target exposure ranges for azole antifungal agents. Population pharmacokinetic modelling of voriconazole has led to studies demonstrating the feasibility of model-guided dose individualization strategies with the drug, which holds significant promise for optimizing therapy. The recent approval of a solid oral tablet formulation of posaconazole with improved bioavailability and once-daily dosing has significantly improved the clinical utility of this agent. Further clinical experience with the investigational azole isavuconazole is needed to determine the role of individualized therapy. The coordination of CYP2C19 pharmacogenomic testing with model-guided dose individualization holds significant promise for optimizing therapy with voriconazole. Pharmacokinetic challenges with itraconazole, voriconazole and posaconazole oral suspension continue to require therapeutic drug monitoring to individualize therapy and optimize treatment outcomes.

  17. Adverse interactions between antifungal azoles and vincristine: review and analysis of cases.

    PubMed

    Moriyama, Brad; Henning, Stacey A; Leung, Janice; Falade-Nwulia, Oluwaseun; Jarosinski, Paul; Penzak, Scott R; Walsh, Thomas J

    2012-07-01

    Triazole and imidazole antifungal agents inhibit metabolism of vincristine, leading to excess vinca alkaloid exposure and severe neurotoxicity. Recent reports of debilitating interactions between vincristine and itraconazole, as well as posaconazole, voriconazole and ketoconazole underscore the need to improve medical awareness of this adverse combination. We, therefore, undertook a comprehensive analysis of reports of adverse drug interactions (ADIs) with the combination of vincristine and azole antifungal agents, established a new classification, and provided a detailed summary of these toxicities. In patients who had sufficient data for analysis, 47 individuals were identified who had an ADI with the combination of vincristine and antifungal azoles. Median age was 8 years (1.3-68 years) with 33(70%) having a diagnosis of acute lymphoblastic leukaemia. Median time to ADI with vincristine was 9.5 days with itraconazole, 13.5 days posaconazole and 30 days voriconazole. The median number of vincristine doses preceding the ADI was 2 doses with itraconazole, 3 doses posaconazole and 2 doses voriconazole. The most common severe ADIs included gastrointestinal toxicity, peripheral neuropathy, hyponatremia/SIADH, autonomic neuropathy and seizures. Recovery from these ADIs occurred in 80.6% of patients. We recommend using alternative antifungal agents if possible in patients receiving vincristine to avoid this serious and potentially life-threatening drug interaction. © 2011 Blackwell Verlag GmbH.

  18. Unexpected effects of azole transporter inhibitors on antifungal susceptibility in Candida glabrata and other pathogenic Candida species.

    PubMed

    Nagayoshi, Yohsuke; Miyazaki, Taiga; Shimamura, Shintaro; Nakayama, Hironobu; Minematsu, Asuka; Yamauchi, Shunsuke; Takazono, Takahiro; Nakamura, Shigeki; Yanagihara, Katsunori; Kohno, Shigeru; Mukae, Hiroshi; Izumikawa, Koichi

    2017-01-01

    The pathogenic fungus Candida glabrata is often resistant to azole antifungal agents. Drug efflux through azole transporters, such as Cdr1 and Cdr2, is a key mechanism of azole resistance and these genes are under the control of the transcription factor Pdr1. Recently, the monoamine oxidase A (MAO-A) inhibitor clorgyline was shown to inhibit the azole efflux pumps, leading to increased azole susceptibility in C. glabrata. In the present study, we have evaluated the effects of clorgyline on susceptibility of C. glabrata to not only azoles, but also to micafungin and amphotericin B, using wild-type and several mutant strains. The addition of clorgyline to the culture media increased fluconazole susceptibility of a C. glabrata wild-type strain, whereas micafungin and amphotericin B susceptibilities were markedly decreased. These phenomena were also observed in other medically important Candida species, including Candida albicans, Candida parapsilosis, Candida tropicalis, and Candida krusei. Expression levels of CDR1, CDR2 and PDR1 mRNAs and an amount of Cdr1 protein in the C. glabrata wild-type strain were highly increased in response to the treatment with clorgyline. However, loss of Cdr1, Cdr2, Pdr1, and a putative clorgyline target (Fms1), which is an ortholog of human MAO-A, or overexpression of CDR1 did not affect the decreased susceptibility to micafungin and amphotericin B in the presence of clorgyline. The presence of other azole efflux pump inhibitors including milbemycin A4 oxime and carbonyl cyanide 3-chlorophenylhydrazone also decreased micafungin susceptibility in C. glabrata wild-type, Δcdr1, Δcdr2, and Δpdr1 strains. These findings suggest that azole efflux pump inhibitors increase azole susceptibility but concurrently induce decreased susceptibility to other classes of antifungals independent of azole transporter functions.

  19. Unexpected effects of azole transporter inhibitors on antifungal susceptibility in Candida glabrata and other pathogenic Candida species

    PubMed Central

    Nagayoshi, Yohsuke; Shimamura, Shintaro; Nakayama, Hironobu; Minematsu, Asuka; Yamauchi, Shunsuke; Takazono, Takahiro; Nakamura, Shigeki; Yanagihara, Katsunori; Kohno, Shigeru; Mukae, Hiroshi; Izumikawa, Koichi

    2017-01-01

    The pathogenic fungus Candida glabrata is often resistant to azole antifungal agents. Drug efflux through azole transporters, such as Cdr1 and Cdr2, is a key mechanism of azole resistance and these genes are under the control of the transcription factor Pdr1. Recently, the monoamine oxidase A (MAO-A) inhibitor clorgyline was shown to inhibit the azole efflux pumps, leading to increased azole susceptibility in C. glabrata. In the present study, we have evaluated the effects of clorgyline on susceptibility of C. glabrata to not only azoles, but also to micafungin and amphotericin B, using wild-type and several mutant strains. The addition of clorgyline to the culture media increased fluconazole susceptibility of a C. glabrata wild-type strain, whereas micafungin and amphotericin B susceptibilities were markedly decreased. These phenomena were also observed in other medically important Candida species, including Candida albicans, Candida parapsilosis, Candida tropicalis, and Candida krusei. Expression levels of CDR1, CDR2 and PDR1 mRNAs and an amount of Cdr1 protein in the C. glabrata wild-type strain were highly increased in response to the treatment with clorgyline. However, loss of Cdr1, Cdr2, Pdr1, and a putative clorgyline target (Fms1), which is an ortholog of human MAO-A, or overexpression of CDR1 did not affect the decreased susceptibility to micafungin and amphotericin B in the presence of clorgyline. The presence of other azole efflux pump inhibitors including milbemycin A4 oxime and carbonyl cyanide 3-chlorophenylhydrazone also decreased micafungin susceptibility in C. glabrata wild-type, Δcdr1, Δcdr2, and Δpdr1 strains. These findings suggest that azole efflux pump inhibitors increase azole susceptibility but concurrently induce decreased susceptibility to other classes of antifungals independent of azole transporter functions. PMID:28700656

  20. Inhibition of the enzymatic activity of heme oxygenases by azole-based antifungal drugs.

    PubMed

    Kinobe, Robert T; Dercho, Ryan A; Vlahakis, Jason Z; Brien, James F; Szarek, Walter A; Nakatsu, Kanji

    2006-10-01

    Ketoconazole (KTZ) and other azole antifungal agents are known to have a variety of actions beyond the inhibition of sterol synthesis in fungi. These drugs share structural features with a series of novel heme oxygenase (HO) inhibitors designed in our laboratory. Accordingly, we hypothesized that therapeutically used azole-based antifungal drugs are effective HO inhibitors. Using gas chromatography to quantify carbon monoxide formation in vitro and in vivo, we have shown that azole-containing antifungal drugs are potent HO inhibitors. Terconazole, sulconazole, and KTZ were the most potent drugs with IC(50) values of 0.41 +/- 0.01, 1.1 +/- 0.4, and 0.3 +/- 0.1 microM for rat spleen microsomal HO activity, respectively. Kinetic characterization revealed that KTZ was a noncompetitive HO inhibitor. In the presence of KTZ (2.5 and 10 microM), K(m) values for both rat spleen and brain microsomal HO were not altered; however, a significant decrease in the catalytic capacity (V(max)) was observed (P < 0.005). KTZ was also found to weakly inhibit nitric-oxide synthase with an IC(50) of 177 +/- 2 microM but had no effect on the enzymatic activity of NADPH cytochrome P450 reductase. Because these drugs were effective within the concentration range observed in humans, it is possible that inhibition of HO may play a role in some of the pharmacological actions of these antimycotic drugs.

  1. Inhibition of human CYP19 by azoles used as antifungal agents and aromatase inhibitors, using a new LC-MS/MS method for the analysis of estradiol product formation.

    PubMed

    Trösken, Eva R; Fischer, Kathrin; Völkel, Wolfgang; Lutz, Werner K

    2006-02-15

    Azoles are used as fungicides in agriculture or antifungal drugs in medicine. Their therapeutic activity is based on the inhibition of fungal lanosterol-14alpha-demethylase (CYP51). Azoles are also used for the treatment of estrogen-dependent diseases, e.g. in breast cancer therapy. Inhibition of CYP19 (aromatase) is the working principle for tumor therapy, but is an unwanted side effect of azoles used as fungicides or antifungal drugs. The inhibition of recombinant human CYP19 by 21 azoles in use for the three different purposes was investigated using the natural substrate testosterone. Estradiol product formation was measured by a newly developed and fully validated analytical method based on liquid chromatography-tandem mass spectrometry utilizing photospray ionization (APPI). Potency of enzyme inhibition was expressed in terms of IC50 concentrations. The two cytostatic drugs fadrozole and letrozole were the most potent inhibitors. However, azoles used as fungicides, e.g. prochloraz, or as antifungal drugs, e.g. bifonazole, were almost as potent inhibitors of aromatase as the drugs used in tumor therapy. Comparison of plasma concentrations that may be reached in antifungal therapy do not allow for large safety factors for bifonazole and miconazole. The IC50 values were compared to data obtained with other substrates, such as the pseudo-substrate dibenzylfluorescein (DBF). A high correlation was found, indicating that the fluorescence assay with DBF can well be used for potency ranking and screening of chemicals for aromatase inhibition. The data for antifungal drugs show that side effects on steroid hormone synthesis in humans due to inhibition of aromatase should be considered.

  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. The Hsp90 Co-chaperones Sti1, Aha1, and P23 Regulate Adaptive Responses to Antifungal Azoles

    PubMed Central

    Gu, Xiaokui; Xue, Wei; Yin, Yajing; Liu, Hongwei; Li, Shaojie; Sun, Xianyun

    2016-01-01

    Heat Shock Protein 90 (Hsp90) is essential for tumor progression in humans and drug resistance in fungi. However, the roles of its many co-chaperones in antifungal resistance are unknown. In this study, by susceptibility test of Neurospora crassa mutants lacking each of 18 Hsp90/Calcineurin system member genes (including 8 Hsp90 co-chaperone genes) to antifungal drugs and other stresses, we demonstrate that the Hsp90 co-chaperones Sti1 (Hop1 in yeast), Aha1, and P23 (Sba1 in yeast) were required for the basal resistance to antifungal azoles and heat stress. Deletion of any of them resulted in hypersensitivity to azoles and heat. Liquid chromatography–mass spectrometry (LC-MS) analysis showed that the toxic sterols eburicol and 14α-methyl-3,6-diol were significantly accumulated in the sti1 and p23 deletion mutants after ketoconazole treatment, which has been shown before to led to cell membrane stress. At the transcriptional level, Aha1, Sti1, and P23 positively regulate responses to ketoconazole stress by erg11 and erg6, key genes in the ergosterol biosynthetic pathway. Aha1, Sti1, and P23 are highly conserved in fungi, and sti1 and p23 deletion also increased the susceptibility to azoles in Fusarium verticillioides. These results indicate that Hsp90-cochaperones Aha1, Sti1, and P23 are critical for the basal azole resistance and could be potential targets for developing new antifungal agents. PMID:27761133

  4. An Aptamer-Based Biosensor for the Azole Class of Antifungal Drugs.

    PubMed

    Wiedman, Gregory R; Zhao, Yanan; Mustaev, Arkady; Ping, Jinglei; Vishnubhotla, Ramya; Johnson, A T Charlie; Perlin, David S

    2017-01-01

    This technical report describes the development of an aptamer for sensing azole antifungal drugs during therapeutic drug monitoring. Modified synthetic evolution of ligands through exponential enrichment (SELEX) was used to discover a DNA aptamer recognizing azole class antifungal drugs. This aptamer undergoes a secondary structural change upon binding to its target molecule, as shown through fluorescence anisotropy-based binding measurements. Experiments using circular dichroism spectroscopy revealed a unique G-quadruplex structure that was essential and specific for binding to the azole antifungal target. Aptamer-functionalized graphene field effect transistor (GFET) devices were created and used to measure the strength of binding of azole antifungals to this surface. In total, this aptamer and the supporting sensing platform provide a valuable tool for therapeutic drug monitoring of patients with invasive fungal infections. IMPORTANCE We have developed the first aptamer directed toward the azole class of antifungal drugs and a functional biosensor for these drugs. This aptamer has a unique secondary structure that allows it to bind to highly hydrophobic drugs. The aptamer works as a capture component of a graphene field effect transistor device. These devices can provide a quick and easy assay for determining drug concentrations. These will be useful for therapeutic drug monitoring of azole antifungal drugs, which is necessary to deal with the complex drug dosage profiles.

  5. An Aptamer-Based Biosensor for the Azole Class of Antifungal Drugs

    PubMed Central

    Zhao, Yanan; Mustaev, Arkady; Ping, Jinglei; Vishnubhotla, Ramya; Johnson, A. T. Charlie; Perlin, David S.

    2017-01-01

    ABSTRACT This technical report describes the development of an aptamer for sensing azole antifungal drugs during therapeutic drug monitoring. Modified synthetic evolution of ligands through exponential enrichment (SELEX) was used to discover a DNA aptamer recognizing azole class antifungal drugs. This aptamer undergoes a secondary structural change upon binding to its target molecule, as shown through fluorescence anisotropy-based binding measurements. Experiments using circular dichroism spectroscopy revealed a unique G-quadruplex structure that was essential and specific for binding to the azole antifungal target. Aptamer-functionalized graphene field effect transistor (GFET) devices were created and used to measure the strength of binding of azole antifungals to this surface. In total, this aptamer and the supporting sensing platform provide a valuable tool for therapeutic drug monitoring of patients with invasive fungal infections. IMPORTANCE We have developed the first aptamer directed toward the azole class of antifungal drugs and a functional biosensor for these drugs. This aptamer has a unique secondary structure that allows it to bind to highly hydrophobic drugs. The aptamer works as a capture component of a graphene field effect transistor device. These devices can provide a quick and easy assay for determining drug concentrations. These will be useful for therapeutic drug monitoring of azole antifungal drugs, which is necessary to deal with the complex drug dosage profiles. PMID:28861519

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

    PubMed Central

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

    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. Transcription factor ADS-4 regulates adaptive responses and resistance to antifungal azole stress.

    PubMed

    Wang, Kangji; Zhang, Zhenying; Chen, Xi; Sun, Xianyun; Jin, Cheng; Liu, Hongwei; Li, Shaojie

    2015-09-01

    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. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  8. Newer antifungal agents.

    PubMed

    Türel, Ozden

    2011-03-01

    The frequency and spectrum of fungal infections have been increasing steadily over the last several decades. The reason for this increase may be explained by the increase in the number of immunocompromised patients due to malignancies, AIDS, invasive surgical procedures and transplantation. In parallel with this increase, several therapeutic options have become available but problems such as intrinsic or acquired antifungal resistance have led researchers to develop new antifungal drugs with expanded effectiveness. Reduced toxicity, enhancement of bioavailability and counteraction of resistance are features desired by clinicians. The aim of this article is to summarize the studies involving isavuconazole, ravuconazole, albaconazole, aminocandin and some other investigational antifungal agents. Most data on the clinical use of ravuconazole, isavuconazole and albaconazole are mainly available as meeting abstracts or limited to animal studies or Phase I/II studies in humans. These new antifungal agents in development offer extended half-lives, possibly reduced drug interaction profiles and good tolerance. In addition to activity against Candida and Aspergillus spp., they have a broad spectrum of activity including activity against resistant and emerging pathogens. The real possibilities of these agents will only be fully understood after adequate randomized clinical trials.

  9. 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

  10. Antifungal activity of azole compounds CPA18 and CPA109 against azole-susceptible and -resistant strains of Candida albicans.

    PubMed

    Calabrese, Elena C; Castellano, Sabrina; Santoriello, Marisabella; Sgherri, Cristina; Quartacci, Mike F; Calucci, Lucia; Warrilow, Andrew G S; Lamb, David C; Kelly, Steven L; Milite, Ciro; Granata, Ilaria; Sbardella, Gianluca; Stefancich, Giorgio; Maresca, Bruno; Porta, Amalia

    2013-05-01

    In this study we investigated the in vitro fungistatic and fungicidal activities of CPA18 and CPA109, two azole compounds with original structural features, alone and in combination with fluconazole against fluconazole-susceptible and -resistant Candida albicans strains. Antifungal activities were measured by MIC evaluation and time-kill studies. Azole binding analysis was performed by UV-Vis spectroscopy. Hyphal growth inhibition and filipin and propidium iodide staining assays were used for morphological analysis. An analysis of membrane lipids was also performed to gauge alterations in membrane composition and integrity. Synergism was calculated using fractional inhibitory concentration indices (FICIs). Evaluation of cytotoxicity towards murine macrophages was performed to verify selective antifungal activity. Even though their binding affinity to C. albicans Erg11p is comparable to that of fluconazole, CPA compounds are active against resistant strains of C. albicans with a mutation in ERG11 sequences and/or overexpressing the ABC transporter genes CDR1 and CDR2, which encode ATP-dependent efflux pumps. Moreover, CPA18 is fungistatic, even against the two resistant strains, and was found to be synergistic with fluconazole. Differently from fluconazole and other related azoles, CPA compounds induced marked changes in membrane permeability and dramatic alterations in membrane lipid composition. Our outcomes suggest that CPA compounds are able to overcome major mechanisms of resistance in C. albicans. Also, they are promising candidates for combination treatment that could reduce the toxicity caused by high fluconazole doses, particularly in immunocompromised patients.

  11. 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

    2015-09-02

    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.

  12. Chiral profiling of azole antifungals in municipal wastewater and recipient rivers of the Pearl River Delta, China.

    PubMed

    Huang, Qiuxin; Wang, Zhifang; Wang, Chunwei; Peng, Xianzhi

    2013-12-01

    Enantiomeric compositions and fractions (EFs) of three chiral imidazole (econazole, ketoconazole, and miconazole) and one chiral triazole (tebuconazole) antifungals were investigated in wastewater, river water, and bed sediment of the Pearl River Delta, South China. The imidazole pharmaceuticals in the untreated wastewater were racemic to weakly nonracemic (EFs of 0.450-0.530) and showed weak enantioselectivity during treatment in the sewage treatment plant. The EFs of the dissolved azole antifungals were usually different from those of the sorbed azoles in the suspended particulate matter, suggesting different behaviors for the enantiomers of the chiral azole antifungals in the dissolved and particulate phases of the wastewater. The azole antifungals were widely present in the rivers. The bed sediment was a sink for the imidazole antifungals. The imidazoles were prevalently racemic, whereas tebuconazole was widely nonracemic in the rivers. Seasonal effects were observed on distribution and chirality of the azole antifungals. Concentrations of the azole antifungals in the river water were relatively higher in winter than in spring and summer while the EF of miconazole in the river water was higher in summer. The mechanism of enantiomeric behavior of the chiral azole antifungals in the environment warrants further research.

  13. 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.

  14. 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.

  15. 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

  16. Azole antifungals: 35 years of invasive fungal infection management.

    PubMed

    Allen, David; Wilson, Dustin; Drew, Richard; Perfect, John

    2015-06-01

    Prior to 1981, treatment options for invasive fungal infections were limited and associated with significant toxicities. The introduction of ketoconazole marked the beginning of an era of dramatic improvements over previous therapies for non-life-threatening mycosis. After nearly a decade of use, ketoconazole was quickly replaced by the triazoles fluconazole and itraconazole due to significant improvements in pharmacokinetic profile, spectrum of activity and safety. The triazoles posaconazole and voriconazole followed, and were better known for their further extended spectrum, specifically against emerging mold infections. With the exception of fluconazole, the triazoles have been plagued with significant inter- and intrapatient pharmacokinetic variability and all possess significant drug interactions. Azoles currently in development appear to combine an in vitro spectrum of activity comparable to voriconazole and posaconazole with more predictable pharmacokinetics and fewer adverse effects.

  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. Simultaneous determination of seven azole antifungal drugs in serum by ultra-high pressure liquid chromatography and diode array detection.

    PubMed

    Mistretta, V; Dubois, N; Denooz, R; Charlier, C

    2014-01-01

    Azole antifungals are a group of fungistatic agents that can be administered orally or parenterally. The determination of the concentrations of these antifungals (miconazole, fluconazole, ketoconazole, posaconazole, voriconazole, itraconazole, and its major active metabolite, hydroxy-itraconazole) in serum can be useful to adapt the doses to pharmacological ranges because of large variability in the absorption and metabolism of the drugs, multiple drug interactions, but also potential resistance or toxicity. A method was developed and validated for the simultaneous determination of these drugs in serum utilizing ultra-high pressure liquid chromatography and diode array detection (UHPLC-DAD). After a simple and rapid liquid-liquid extraction, the pre-treated sample was analysed on an UHPLC-DAD system (Waters Corporation(®)). The chromatographic separation was carried out on an Acquity BEH C18 column (Waters Corporation) with a gradient mode of mobile phase composed of acetonitrile and aqueous ammonium bicarbonate 10·0 M pH10. The flow rate was 0·4 ml/min and the injection volume was 5 μl. The identification wavelength varied according to the drug from 210 to 260 nm. The method was validated by the total error method approach by using an analytical validation software (e•noval V3·0 Arlenda(®)). The seven azole antifungals were identified by retention time and specific UV spectra, over a 13-minute run time. All calibration curves showed good linearity (r(2)>0·99) in ranges considered clinically adequate. The assay was linear from 0·05 to 10 mg/l for voriconazole, posaconazole, itraconazole, hydroxy-itraconazole, and ketoconazole, from 0·3 to 10 mg/l for fluconazole, and from 0·1 to 10 mg/l for miconazole. The bias and imprecision values for intra- and inter-assays were lower than 10% and than 15%, respectively. In conclusion, a simple, sensitive, and selective UHPLC-DAD method was developed and validated to determine seven azole antifungal drugs in human

  19. A defect in iron uptake enhances the susceptibility of Cryptococcus neoformans to azole antifungal drugs

    PubMed Central

    Kim, Jeongmi; Cho, Yong-Joon; Do, Eunsoo; Choi, Jaehyuk; Hu, Guanggan; Cadieux, Brigitte; Chun, Jongsik; Lee, Younghoon; Kronstad, James W.; Jung, Won Hee

    2015-01-01

    The high-affinity reductive iron uptake system that includes a ferroxidase (Cfo1) and an iron permease (Cft1) is critical for the pathogenesis of Cryptococcus neoformans. In addition, a mutant lacking CFO1 or CFT1 not only has reduced iron uptake but also displays a markedly increased susceptibility to azole antifungal drugs. Altered antifungal susceptibility of the mutants was of particular interest because the iron uptake system has been proposed as an alternative target for antifungal treatment. In this study, we used transcriptome analysis to begin exploring the molecular mechanisms of altered antifungal susceptibility in a cfo1 mutant. The wild-type strain and the cfo1 mutant were cultured with or without the azole antifungal drug fluconazole and their transcriptomes were compared following sequencing with Illumina Genome Analyzer IIx (GAIIx) technology. As expected, treatment of both strains with fluconazole caused elevated expression of genes in the ergosterol biosynthetic pathway that includes the target enzyme Erg11. Additionally, genes differentially expressed in the cfo1 mutant were involved in iron uptake and homeostasis, mitochondrial functions and respiration. The cfo1 mutant also displayed phenotypes consistent with these changes including a reduced ratio of NAD+/NADH and down-regulation of Fe-S cluster synthesis. Moreover, combination treatment of the wild-type strain with fluconazole and the respiration inhibitor diphenyleneiodonium dramatically increased susceptibility to fluconazole. This result supports the hypothesis that down-regulation of genes required for respiration contributed to the altered fluconazole susceptibility of the cfo1 mutant. Overall, our data suggest that iron uptake and homeostasis play a key role in antifungal susceptibility and could be used as novel targets for combination treatment of cryptococcosis. Indeed, we found that iron chelation in combination with fluconazole treatment synergistically inhibited the growth of C

  20. The yeast Saccharomyces cerevisiae Pdr16p restricts changes in ergosterol biosynthesis caused by the presence of azole antifungals.

    PubMed

    Šimová, Zuzana; Poloncová, Katarína; Tahotná, Dana; Holič, Roman; Hapala, Ivan; Smith, Adam R; White, Theodore C; Griač, Peter

    2013-06-01

    Pdr16p belongs to the family of phosphatidylinositol transfer proteins in yeast. The absence of Pdr16p results in enhanced susceptibility to azole antifungals in Saccharomyces cerevisiae. In the major fungal human pathogen Candida albicans, CaPDR16 is a contributing factor to clinical azole resistance. The current study was aimed at better understanding the function of Pdr16p, especially in relation to azole resistance in S. cerevisiae. We show that deletion of the PDR16 gene increased susceptibility of S. cerevisiae to azole antifungals that are used in clinical medicine and agriculture. Significant differences in the inhibition of the sterol biosynthetic pathway were observed between the pdr16Δ strain and its corresponding wild-type (wt) strain when yeast cells were challenged by sub-inhibitory concentrations of the azoles miconazole or fluconazole. The increased susceptibility to azoles, and enhanced changes in sterol biosynthesis upon exposure to azoles of the pdr16Δ strain compared to wt strain, are not the results of increased intracellular concentration of azoles in the pdr16Δ cells. We also show that overexpression of PDR17 complemented the azole susceptible phenotype of the pdr16Δ strain and corrected the enhanced sterol alterations in pdr16Δ cells in the presence of azoles. Pdr17p was found previously to be an essential part of a complex required for intermembrane transport of phosphatidylserine at regions of membrane apposition. Based on these observations, we propose a hypothesis that Pdr16p assists in shuttling sterols or their intermediates between membranes or, alternatively, between sterol biosynthetic enzymes or complexes.

  1. Interaction of azole antifungal antibiotics with cytochrome P-450-dependent 14 alpha-sterol demethylase purified from Candida albicans.

    PubMed Central

    Hitchcock, C A; Dickinson, K; Brown, S B; Evans, E G; Adams, D J

    1990-01-01

    The interaction of azole antifungal antibiotics with purified Candida albicans cytochrome P-450-dependent 14 alpha-sterol demethylase (P-450DM) was measured spectrophotometrically and by inhibition of enzyme activity. Ketoconazole and ICI 153066 (a triazole derivative) formed low-spin complexes with the ferric cytochrome and induced type II difference spectra. These spectra are indicative of an interaction between the azole moiety and the sixth co-ordination position of P-450DM haem. Both azoles inhibited the binding of CO to the sodium dithionite-reduced ferrous cytochrome, and inhibited reconstituted P-450DM activity by binding to the cytochrome with a one-to-one stoichiometry. Similarly, total inhibition of enzyme activity occurred when equimolar amounts of clotrimazole, miconazole or fluconazole were added to reconstituted P-450DM. These results correlated with the inhibition of P-450DM in broken cell preparations, confirming that all five azoles are potent inhibitors of ergosterol biosynthesis in C. albicans. PMID:2180400

  2. 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

  3. Azole-based antimycotic agents inhibit mold on unseasoned pine

    Treesearch

    Carol. A. Clausen; Vina W. Yang

    2005-01-01

    Inhibiting the growth of mold fungi on cellulose-based building materials may be achievable through the use of azole-based antimycotics. Azoles were variably effective against mold fungi that are frequently found on wood and wood products. Unseasoned southern yellow pine specimens that were dip-treated with varying concentrations of eight azoles were evaluated for...

  4. Nectar yeasts of the Metschnikowia clade are highly susceptible to azole antifungals widely used in medicine and agriculture.

    PubMed

    Álvarez-Pérez, Sergio; de Vega, Clara; Pozo, María I; Lenaerts, Marijke; Van Assche, Ado; Herrera, Carlos M; Jacquemyn, Hans; Lievens, Bart

    2016-02-01

    The widespread use of azole antifungals in medicine and agriculture and the resulting long-persistent residues could potentially affect beneficial fungi. However, there is very little information on the tolerance of non-target environmental fungi to azoles. In this study, we assessed the susceptibility of diverse plant- and insect-associated yeasts from the Metschnikowia clade, including several ecologically important species, to widely used medical and agricultural azoles (epoxiconazole, imazalil, ketoconazole and voriconazole). A total of 120 strains from six species were tested. Minimum inhibitory concentrations (MICs) were determined by the EUCAST broth microdilution procedure after some necessary modifications were made. The majority of species tested were highly susceptible to epoxiconazole, ketoconazole and voriconazole (>95% of strains showed MICs ≤ 0.125 mg l(-1)). Most strains were also very susceptible to imazalil, although MIC values were generally higher than for the other azoles. Furthermore, certain Metschnikowia reukaufii strains displayed a 'trailing' phenotype (i.e. showed reduced but persistent growth at antifungal concentrations above the MIC), but this characteristic was dependent on test conditions. It was concluded that exposure to azoles may pose a risk for ecologically relevant yeasts from the Metschnikowia clade, and thus could potentially impinge on the tripartite interaction linking these fungi with plants and their insect pollinators.

  5. Epidemiology of invasive fungal infections in lung transplant recipients on long-term azole antifungal prophylaxis.

    PubMed

    Chong, Pearlie P; Kennedy, Cassie C; Hathcock, Matthew A; Kremers, Walter K; Razonable, Raymund R

    2015-04-01

    Lung transplant recipients (LTR) at our institution receive prolonged and mostly lifelong azole antifungal (AF) prophylaxis. The impact of this prophylactic strategy on the epidemiology and outcome of invasive fungal infections (IFI) is unknown. This was a single-center, retrospective cohort study. We reviewed the medical records of all adult LTR from January 2002 to December 2011. Overall, 16.5% (15 of 91) of patients who underwent lung transplantation during this time period developed IFI. Nineteen IFI episodes were identified (eight proven, 11 probable), 89% (17 of 19) of which developed during AF prophylaxis. LTR with idiopathic pulmonary fibrosis were more likely to develop IFI (HR: 4.29; 95% CI: 1.15-15.91; p = 0.03). A higher hazard of mortality was observed among those who developed IFI, although this was not statistically significant (hazard ratio [HR]: 1.71; 95% confidence interval [CI] [0.58-4.05]; p = 0.27). Aspergillus fumigatus was the most common cause of IFI (45%), with pulmonary parenchyma being the most common site of infection. None of our patients developed disseminated invasive aspergillosis, cryptococcal or endemic fungal infections. IFI continue to occur in LTR, and the eradication of IFI appears to be challenging even with prolonged prophylaxis. Azole resistance is uncommon despite prolonged AF exposure.

  6. Evaluation of the genotoxicity of the imidazole antifungal climbazole: comparison to published results for other azole compounds.

    PubMed

    Pérez-Rivera, Alex A; Hu, Ting; Aardema, Marilyn J; Nash, J F

    2009-01-01

    Climbazole is an imidazole antifungal agent that can provide anti-dandruff benefits when incorporated into a shampoo matrix. A series of genotoxicity studies were performed to support the human safety of this azole antifungal drug. Climbazole was not mutagenic in the Salmonella typhimurium or Escherichia coli Ames assay and did not induce micronuclei in human lymphocytes. In the mouse lymphoma assay (MLA), climbazole was negative (non-mutagenic) with and without metabolic (S9) activation after a 4 h exposure; an increase in small colony mutants was observed without metabolic activation after a 24 h exposure at concentrations of 15 and 17.5 μg/mL. An in vivo mouse micronucleus test was negative up to a maximum tolerated dose (MTD) of 150 mg/kg climbazole administered orally. In the in vivo/in vitro unscheduled DNA synthesis assay, climbazole showed no evidence of DNA damage in the livers of rats at doses up to the MTD of 200 mg/kg orally. A toxicokinetic study was performed in mice with oral administration of [14C]-climbazole (150 mg/kg). Radioactivity (20.42 μg-equiv./g plasma) was detected 15 min after oral administration of [14C]-climbazole, and the peak concentration was 62.96 μg-equiv./g plasma at 8 h after dosing. The measured amounts of radioactivity in plasma, at all sample times from 15 min up to 24 h, exceeded the concentrations that induced increases in mutation frequency after 24 h exposure of mouse lymphoma cells in vitro (15 and 17.5 μg/mL). These observations lend support to the conclusion that climbazole does not present a genotoxic risk in vivo. Furthermore, these data are consistent with the published data for other azole antifungals that work by preventing the synthesis of ergosterol and, as a class, are generally non-genotoxic, except some isolated positive results of questionable significance. Collectively, these data are supportive of the view that climbazole does not present a genotoxic or carcinogenic risk to humans.

  7. Potent antimicrobial agents against azole-resistant fungi based on pyridinohydrazide and hydrazomethylpyridine structural motifs.

    PubMed

    Backes, Gregory L; Jursic, Branko S; Neumann, Donna M

    2015-07-01

    Schiff base derivatives have recently been shown to possess antimicrobial activity, and these derivatives include a limited number of salicylaldehyde hydrazones. To further explore this structure-activity relationship between salicylaldehyde hydrazones and antifungal activity, we previously synthesized and analyzed a large series of salicylaldehyde and formylpyridinetrione hydrazones for their ability to inhibit fungal growth of both azole-susceptible and azole-resistant species of Candida. While many of these analogs showed excellent growth inhibition with low mammalian cell toxicity, their activity did not extend to azole-resistant species of Candida. To further dissect the structural features necessary to inhibit azole-resistant fungal species, we synthesized a new class of modified salicylaldehyde derivatives and subsequently identified a series of modified pyridine-based hydrazones that had potent fungicidal antifungal activity against multiple Candida spp. Here we would like to present our synthetic procedures as well as the results from fungal growth inhibition assays, mammalian cell toxicity assays, time-kill assays and synergy studies of these novel pyridine-based hydrazones on both azole-susceptible and azole-resistant fungal species.

  8. Susceptibilities of Candida albicans multidrug transporter mutants to various antifungal agents and other metabolic inhibitors.

    PubMed Central

    Sanglard, D; Ischer, F; Monod, M; Bille, J

    1996-01-01

    Some Candida albicans isolates from AIDS patients with oropharyngeal candidiasis are becoming resistant to the azole antifungal agent fluconazole after prolonged treatment with this compound. Most of the C. albicans isolates resistant to fluconazole fail to accumulate this antifungal agent, and this has been considered a cause of resistance. This phenomenon was shown to be linked to an increase in the amounts of mRNA of a C. albicans ABC (ATP-binding cassette) transporter gene called CDR1 and of a gene conferring benomyl resistance (BENr), the product of which belongs to the class of major facilitator multidrug efflux transporters (D. Sanglard, K. Kuchler, F. Ischer, J. L. Pagani, M. Monod, and J. Bille, Antimicrob. Agents Chemother. 39:2378-2386, 1995). To analyze the roles of these multidrug transporters in the efflux of azole antifungal agents, we constructed C. albicans mutants with single and double deletion mutations of the corresponding genes. The mutants were tested for their susceptibilities to these antifungal agents. Our results indicated that the delta cdr1 C. albicans mutant was hypersusceptible to the azole derivatives fluconazole, itraconazole, and ketoconazole, thus showing that the ABC transporter Cdr1 can use these compounds as substrates. The delta cdr1 mutant was also hypersusceptible to other antifungal agents (terbinafine and amorolfine) and to different metabolic inhibitors (cycloheximide, brefeldin A, and fluphenazine). The same mutant was slightly more susceptible than the wild type to nocodazole, cerulenin, and crystal violet but not to amphotericin B, nikkomycin Z, flucytosine, or pradimicin. In contrast, the delta ben mutant was rendered more susceptible only to the mutagen 4-nitroquinoline-N-oxide. However, this mutation increased the susceptibilities of the cells to cycloheximide and cerulenin when the mutation was constructed in a delta cdr1 background. The assay used in the present study could be implemented with new antifungal

  9. Treatment of a clinically relevant plant-pathogenic fungus with an agricultural azole causes cross-resistance to medical azoles and potentiates caspofungin efficacy.

    PubMed

    Serfling, Albrecht; Wohlrab, Johannes; Deising, Holger B

    2007-10-01

    Azoles are extensively applied in agriculture and medicine, and a relationship between the development of azole resistance in agriculture and the development of azole resistance in clinical practice may exist. The maize pathogen Colletotrichum graminicola, causing cutaneous mycosis and keratitis, has been used to investigate the acquisition of resistance to an agricultural azole and the resulting cross-resistance to various medical antifungal agents. Azole-adapted strains were less sensitive to all azoles tested but showed increased sensitivity to caspofungin, amphotericin B, and nystatin. Viability staining and infection assays with excised human skin confirmed these data.

  10. The Synthesis and Study of Azole Carboxamide Nucleosides as Agents Active Against RNA Viruses.

    DTIC Science & Technology

    1986-09-15

    5012 62770A 62770A8,1. AH 355 11. TITLE (Include Security Classification) The Synthesis and Study of Azole Carboxamide Nucleosides as Agents Active...broad-spectrum antiviral agent has stimulated a great deal of effort toward the chemical synthesis of nucleosides of other azole heterocycles. During the...4 II. Chemistry and Discussion . . .. .. . 6 1. Synthesis of Certain 5’-Substituted Derivatives of Ribavirin and Tiazofurin . . .. . 6 2

  11. Effective concentration-based serum pharmacodynamics for antifungal azoles in a murine model of disseminated Candida albicans infection.

    PubMed

    Maki, Katsuyuki; Kaneko, Shuji

    2013-12-01

    An assessment of the effective in vivo concentrations of antifungal drugs is important in determining their pharmacodynamics, and therefore, their optimal dosage regimen. Here we establish the effective in vivo concentration-based pharmacodynamics of three azole antifungal drugs (fluconazole, itraconazole, and ketoconazole) in a murine model of disseminated Candida albicans infection. A key feature of this study was the use of a measure of mycelial (m) growth rather than of yeast growth, and pooled mouse sera rather than synthetic media as a growth medium, for determining the minimum inhibitory concentrations (MICs) of azoles for C. albicans (denoted serum mMICs). The serum mMIC assay was then used to measure antifungal concentrations and effects as serum antifungal titers in the serum of treated mice. Both serum mMIC and sub-mMIC values reflected the effective in vivo serum concentrations. Supra-mMIC and mMIC effects exhibited equivalent efficacies and were concentration-independent, while the sub-mMIC effect was concentration-dependent. Following administration of the minimum drug dosage that inhibited an increase in mouse kidney fungal burden, the duration periods of these effects were similar for all drugs tested. The average duration of either the mMIC effect including the supra-mMIC effect, the sub-mMIC effect, or the post-antifungal effect (PAFE) were 6.9, 6.5 and 10.6 h, respectively. Our study suggests that the area under the curve for serum drug concentration versus time, between the serum mMIC and the sub-mMIC, and exposure time above the serum sub-mMIC after the mMIC effect, are major pharmacodynamic parameters. These findings have important implications for effective concentration-based pharmacodynamics of fungal infections treated with azoles.

  12. 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

  13. 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

  14. The utility of antifungal agents for asthma.

    PubMed

    Gore, Robin B

    2010-01-01

    Recent work demonstrates that patients with refractory asthma are likely to be sensitized to environmental fungi and that specific antifungal treatments may be of benefit to this group. The relationships among fungal sensitization, exposure and asthma severity are imperfectly understood. Exposure to environmental fungi occurs ubiquitously and there is emerging evidence that internal airways colonization could be a source of ongoing exposure. Antifungal treatments appear to improve asthma-related quality of life. Such treatments are generally well tolerated but there are potential side-effects. The mechanisms behind the clinical improvements are not yet fully established. Antifungal treatments are used in some centres for patients with refractory asthma. Further research needs to explore the questions of patient selection, optimum duration of therapy and the prediction and management of azole-corticosteroid drug interactions. Advances in our understanding of the fungal molecular allergome and in our understanding of the allergic importance of small hyphal fragments may help to more precisely define the relationships among fungal sensitization, exposure and asthma severity.

  15. Chitin synthase inhibitors as antifungal agents.

    PubMed

    Chaudhary, Preeti M; Tupe, Santosh G; Deshpande, Mukund V

    2013-02-01

    Increased risk of fungal diseases in immunocompromised patients, emerging fungal pathogens, limited repertoire of antifungal drugs and resistance development against the drugs demands for development of new and effective antifungal agents. With greater knowledge of fungal metabolism efforts are being made to inhibit specific enzymes involved in different biochemical pathways for the development of antifungal drugs. Chitin synthase is one such promising target as it is absent in plants and mammals. Nikkomycin Z, a chitin synthase inhibitor is under clinical development. Chitin synthesis in fungi, chitin synthase as a target for antifungal agent development, different chitin synthase inhibitors isolated from natural sources, randomly synthesized and modified from nikkomycin and polyoxin are discussed in this review.

  16. Antifungal agents in neonates: issues and recommendations.

    PubMed

    Almirante, Benito; Rodríguez, Dolors

    2007-01-01

    Fungal infections are responsible for considerable morbidity and mortality in the neonatal period, particularly among premature neonates. Four classes of antifungal agents are commonly used in the treatment of fungal infections in pediatric patients: polyene macrolides, fluorinated pyrimidines, triazoles, and echinocandins. Due to the paucity of pediatric data, many recommendations for the use of antifungal agents in this population are derived from the experience in adults. The purpose of this article was to review the published data on fungal infections and antifungal agents, with a focus on neonatal patients, and to provide an overview of the differences in antifungal pharmacology in neonates compared with adults. Pharmacokinetic data suggest dosing differences in children versus adult patients with some antifungals, but not all agents have been fully evaluated. The available pharmacokinetic data on the amphotericin B deoxycholate formulation in neonates exhibit considerable variability; nevertheless, the dosage regimen suggested in the neonatal population is similar to that used in adults. More pharmacokinetic information is available on the liposomal and lipid complex preparations of amphotericin B and fluconazole, and it supports their use in neonates; however, the optimal dosage and duration of therapy is difficult to establish. All amphotericin-B formulations, frequently used in combination with flucytosine, are useful for treating disseminated fungal infections and Candida meningitis in neonates. Fluconazole, with potent in vitro activity against Cryptococcus neoformans and almost all Candida spp., has been used in neonates with invasive candidiasis at dosages of 6 mg/kg/day, and for antifungal prophylaxis in high-risk neonates. There are limited data on itraconazole, voriconazole, and posaconazole use in neonates. Caspofungin, which is active against Candida spp. and Aspergillus spp., requires higher doses in children relative to adults, and dosing is

  17. Lipid-based antifungal agents: current status.

    PubMed

    Arikan, S; Rex, J H

    2001-03-01

    Immunocompromised patients are well known to be predisposed to developing invasive fungal infections. These infections are usually difficult to diagnose and more importantly, the resulting mortality rate is high. The limited number of antifungal agents available and their high rate of toxicity are the major factors complicating the issue. However, the development of lipid-based formulations of existing antifungal agents has opened a new era in antifungal therapy. The best examples are the lipid-based amphotericin B preparations, amphotericin B lipid complex (ABLC; Abelcet), amphotericin B colloidal dispersion (ABCD; Amphotec or Amphocil), and liposomal amphotericin B (AmBisome). These formulations have shown that antifungal activity is maintained while toxicity is reduced. This progress is followed by the incorporation of nystatin into liposomes. Liposomal nystatin formulation is under development and studies of it have provided encouraging data. Finally, lipid-based formulations of hamycin, miconazole, and ketoconazole have been developed but remain experimental. Advances in technology of liposomes and other lipid formulations have provided promising new tools for management of fungal infections.

  18. Impact of brief exposure to antifungal agents on the post-antifungal effect and hemolysin activity of oral Candida albicans

    PubMed Central

    ELLEPOLA, Arjuna Nishantha; KHAJAH, Rana; JAYATILAKE, Sumedha; SAMARANAYAKE, Lakshman; SHARMA, Prem; KHAN, Zia

    2015-01-01

    Post-antifungal effect (PAFE) of Candida and its production of hemolysin are determinants of candidal pathogenicity. Candida albicans is the foremost aetiological agent of oral candidosis, which can be treated with polyene, azole, and echinocandin antifungals. However, once administered, the intraoral concentrations of these drugs tend to be subtherapeutic and transient due to the diluent effect of saliva and cleansing effect of the oral musculature. Hence, intra-orally, Candida may undergo a brief exposure to antifungal drugs. Objective Therefore, the PAFE and hemolysin production of oral C. albicans isolates following brief exposure to sublethal concentrations of the foregoing antifungals were evaluated. Material and Methods A total of 50 C. albicans oral isolates obtained from smokers, diabetics, asthmatics using steroid inhalers, partial denture wearers and healthy individuals were exposed to sublethal concentrations of nystatin, amphotericin B, caspofungin, ketoconazole and fluconazole for 60 min. Thereafter, the drugs were removed and the PAFE and hemolysin production were determined by previously described turbidometric and plate assays, respectively. Results Nystatin, amphotericin B, caspofungin and ketoconazole induced mean PAFE (hours) of 2.2, 2.18, 2.2 and 0.62, respectively. Fluconazole failed to produce a PAFE. Hemolysin production of these isolates was suppressed with a percentage reduction of 12.27, 13.47, 13.33, 8.53 and 4.93 following exposure to nystatin, amphotericin B, caspofungin, ketoconazole and fluconazole, respectively. Conclusions Brief exposure to sublethal concentrations of antifungal drugs appears to exert an antifungal effect by interfering with the growth as well as hemolysin production of C. albicans. PMID:26398514

  19. Antifungal agents: mode of action, mechanisms of resistance, and correlation of these mechanisms with bacterial resistance.

    PubMed

    Ghannoum, M A; Rice, L B

    1999-10-01

    The increased use of antibacterial and antifungal agents in recent years has resulted in the development of resistance to these drugs. The significant clinical implication of resistance has led to heightened interest in the study of antimicrobial resistance from different angles. Areas addressed include mechanisms underlying this resistance, improved methods to detect resistance when it occurs, alternate options for the treatment of infections caused by resistant organisms, and strategies to prevent and control the emergence and spread of resistance. In this review, the mode of action of antifungals and their mechanisms of resistance are discussed. Additionally, an attempt is made to discuss the correlation between fungal and bacterial resistance. Antifungals can be grouped into three classes based on their site of action: azoles, which inhibit the synthesis of ergosterol (the main fungal sterol); polyenes, which interact with fungal membrane sterols physicochemically; and 5-fluorocytosine, which inhibits macromolecular synthesis. Many different types of mechanisms contribute to the development of resistance to antifungals. These mechanisms include alteration in drug target, alteration in sterol biosynthesis, reduction in the intercellular concentration of target enzyme, and overexpression of the antifungal drug target. Although the comparison between the mechanisms of resistance to antifungals and antibacterials is necessarily limited by several factors defined in the review, a correlation between the two exists. For example, modification of enzymes which serve as targets for antimicrobial action and the involvement of membrane pumps in the extrusion of drugs are well characterized in both the eukaryotic and prokaryotic cells.

  20. Effect of pH on In Vitro Susceptibility of Candida glabrata and Candida albicans to 11 Antifungal Agents and Implications for Clinical Use

    PubMed Central

    Danby, Claire S.; Boikov, Dina; Rautemaa-Richardson, Rina

    2012-01-01

    The treatment of vulvovaginal candidiasis (VVC) due to Candida glabrata is challenging, with limited therapeutic options. Unexplained disappointing clinical efficacy has been reported with systemic and topical azole antifungal agents in spite of in vitro susceptibility. Given that the vaginal pH of patients with VVC is unchanged at 4 to 4.5, we studied the effect of pH on the in vitro activity of 11 antifungal agents against 40 C. glabrata isolates and compared activity against 15 fluconazole-sensitive and 10 reduced-fluconazole-susceptibility C. albicans strains. In vitro susceptibility to flucytosine, fluconazole, voriconazole, posaconazole, itraconazole, ketoconazole, clotrimazole, miconazole, ciclopirox olamine, amphotericin B, and caspofungin was determined using the CLSI method for yeast susceptibility testing. Test media were buffered to pHs of 7, 6, 5, and 4. Under conditions of reduced pH, C. glabrata isolates remained susceptible to caspofungin and flucytosine; however, there was a dramatic increase in the MIC90 for amphotericin B and every azole drug tested. Although susceptible to other azole drugs tested at pH 7, C. albicans strains with reduced fluconazole susceptibility also demonstrated reduced susceptibility to amphotericin B and all azoles at pH 4. In contrast, fluconazole-sensitive C. albicans isolates remained susceptible at low pH to azoles, in keeping with clinical observations. In selecting agents for treatment of recurrent C. glabrata vaginitis, clinicians should recognize the limitations of in vitro susceptibility testing utilizing pH 7.0. PMID:22232293

  1. Effect of pH on in vitro susceptibility of Candida glabrata and Candida albicans to 11 antifungal agents and implications for clinical use.

    PubMed

    Danby, Claire S; Boikov, Dina; Rautemaa-Richardson, Rina; Sobel, Jack D

    2012-03-01

    The treatment of vulvovaginal candidiasis (VVC) due to Candida glabrata is challenging, with limited therapeutic options. Unexplained disappointing clinical efficacy has been reported with systemic and topical azole antifungal agents in spite of in vitro susceptibility. Given that the vaginal pH of patients with VVC is unchanged at 4 to 4.5, we studied the effect of pH on the in vitro activity of 11 antifungal agents against 40 C. glabrata isolates and compared activity against 15 fluconazole-sensitive and 10 reduced-fluconazole-susceptibility C. albicans strains. In vitro susceptibility to flucytosine, fluconazole, voriconazole, posaconazole, itraconazole, ketoconazole, clotrimazole, miconazole, ciclopirox olamine, amphotericin B, and caspofungin was determined using the CLSI method for yeast susceptibility testing. Test media were buffered to pHs of 7, 6, 5, and 4. Under conditions of reduced pH, C. glabrata isolates remained susceptible to caspofungin and flucytosine; however, there was a dramatic increase in the MIC(90) for amphotericin B and every azole drug tested. Although susceptible to other azole drugs tested at pH 7, C. albicans strains with reduced fluconazole susceptibility also demonstrated reduced susceptibility to amphotericin B and all azoles at pH 4. In contrast, fluconazole-sensitive C. albicans isolates remained susceptible at low pH to azoles, in keeping with clinical observations. In selecting agents for treatment of recurrent C. glabrata vaginitis, clinicians should recognize the limitations of in vitro susceptibility testing utilizing pH 7.0.

  2. [In vitro antifungal activity of azoles and amphotericin B against Malassezia furfur by the CLSI M27-A3 microdilution and Etest(®) methods].

    PubMed

    Galvis-Marín, Juan Camilo; Rodríguez-Bocanegra, María Ximena; Pulido-Villamarín, Adriana Del Pilar; Castañeda-Salazar, Rubiela; Celis-Ramírez, Adriana Marcela; Linares-Linares, Melva Yomary

    Malassezia furfur is a human skin commensal yeast that can cause skin and opportunistic systemic infections. Given its lipid dependant status, the reference methods established by the Clinical and Laboratory Standards Institute (CLSI) to evaluate antifungal susceptibility in yeasts are not applicable. To evaluate the in vitro susceptibility of M. furfur isolates from infections in humans to antifungals of clinical use. The susceptibility profile to amphotericin B, itraconazole, ketoconazole and voriconazole of 20 isolates of M. furfur, using the broth microdilution method (CLSI M27-A3) and Etest(®), was evaluated. Itraconazole and voriconazole had the highest antifungal activity against the isolates tested. The essential agreement between the two methods for azoles antifungal activity was in the region of 60-85% and the categorical agreement was around 70-80%, while the essential and categorical agreement for amphotericin B was 10%. The azoles were the compounds that showed the highest antifungal activity against M. furfur, as determined by the two techniques used; however more studies need to be performed to support that Etest(®) is a reliable method before its implementation as a routine clinical laboratory test. Copyright © 2016 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. Nanoparticles as safe and effective delivery systems of antifungal agents: Achievements and challenges.

    PubMed

    Soliman, Ghareb M

    2017-03-19

    Invasive fungal infections are becoming a major health concern in several groups of patients leading to severe morbidity and mortality. Moreover, cutaneous fungal infections are a major cause of visits to outpatient dermatology clinics. Despite the availability of several effective agents in the antifungal drug arena, their therapeutic outcome is less than optimal due to limitations related to drug physicochemical properties and toxicity. For instance, poor aqueous solubility limits the formulation options and efficacy of several azole antifungal drugs while toxicity limits the benefits of many other drugs. Nanoparticles hold great promise to overcome these limitations due to their ability to enhance drug aqueous solubility, bioavailability and antifungal efficacy. Further, drug incorporation into nanoparticles could greatly reduce its toxicity. Despite these interesting nanoparticle features, there are only few marketed nanoparticle-based antifungal drug formulations. This review sheds light on different classes of nanoparticles used in antifungal drug delivery, such as lipid-based vesicles, polymeric micelles, solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions and dendrimers with emphasis on their advantages and limitations. Translation of these nanoformulations from the lab to the clinic could be facilitated by focusing the research on overcoming problems related to nanoparticle stability, drug loading and high cost of production and standardization.

  4. Clinical implications of globally emerging azole resistance in Aspergillus fumigatus.

    PubMed

    Meis, Jacques F; Chowdhary, Anuradha; Rhodes, Johanna L; Fisher, Matthew C; Verweij, Paul E

    2016-12-05

    Aspergillus fungi are the cause of an array of diseases affecting humans, animals and plants. The triazole antifungal agents itraconazole, voriconazole, isavuconazole and posaconazole are treatment options against diseases caused by Aspergillus However, resistance to azoles has recently emerged as a new therapeutic challenge in six continents. Although de novo azole resistance occurs occasionally in patients during azole therapy, the main burden is the aquisition of resistance through the environment. In this setting, the evolution of resistance is attributed to the widespread use of azole-based fungicides. Although ubiquitously distributed, A. fumigatus is not a phytopathogen. However, agricultural fungicides deployed against plant pathogenic moulds such as Fusarium, Mycospaerella and A. flavus also show activity against A. fumigatus in the environment and exposure of non-target fungi is inevitable. Further, similarity in molecule structure between azole fungicides and antifungal drugs results in cross-resistance of A. fumigatus to medical azoles. Clinical studies have shown that two-thirds of patients with azole-resistant infections had no previous history of azole therapy and high mortality rates between 50% and 100% are reported in azole-resistant invasive aspergillosis. The resistance phenotype is associated with key mutations in the cyp51A gene, including TR34/L98H, TR53 and TR46/Y121F/T289A resistance mechanisms. Early detection of resistance is of paramount importance and if demonstrated, either with susceptibility testing or through molecular analysis, azole monotherapy should be avoided. Liposomal amphotericin B or a combination of voriconazole and an echinocandin are recomended for azole-resistant aspergillosis.This article is part of the themed issue 'Tackling emerging fungal threats to animal health, food security and ecosystem resilience'.

  5. Antimycotic azoles. 6. Synthesis and antifungal properties of terconazole, a novel triazole ketal.

    PubMed

    Heeres, J; Hendrickx, R; Van Cutsem, J

    1983-04-01

    The preparation and antifungal properties of cis-1-[4-[[2-(2,4-dichlorophenyl)-2-(1H-1,2,4-triazol-1-ylmethyl)-1, 3-dioxolan-4-yl]methoxy]phenyl]-4-(1-methylethyl)piperazine are reported. Terconazole has a high topical in vivo activity against vaginal candidosis in rats and against dermatophytosis in guinea pigs.

  6. Special Issue: Novel Antifungal Drug Discovery

    PubMed Central

    Poeta, Maurizio Del

    2016-01-01

    This Special Issue is designed to highlight the latest research and development on new antifungal compounds with mechanisms of action different from the ones of polyenes, azoles, and echinocandins. The papers presented here highlight new pathways and targets that could be exploited for the future development of new antifungal agents to be used alone or in combination with existing antifungals. A computational model for better predicting antifungal drug resistance is also presented. PMID:28058254

  7. 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.

  8. Synthesis, antifungal activities and qualitative structure activity relationship of carabrone hydrazone derivatives as potential antifungal agents.

    PubMed

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

    2014-03-11

    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.

  9. Quinone derivatives isolated from the endolichenic fungus Phialocephala fortinii are Mdr1 modulators that combat azole resistance in Candida albicans

    PubMed Central

    Xie, Fei; Chang, Wenqiang; Zhang, Ming; Li, Ying; Li, Wei; Shi, Hongzhuo; Zheng, Sha; Lou, Hongxiang

    2016-01-01

    One of the main azole-resistance mechanisms in Candida pathogens is the upregulation of drug efflux pumps, which compromises the efficacy of azoles and results in treatment failure. The combination of azole-antifungal agents with efflux pump inhibitors represents a promising strategy to combat fungal infection. High-throughput screening of 150 extracts obtained from endolichenic fungal cultures led to the discovery that the extract of Phialocephala fortinii exhibits potent activity for the reversal of azole resistance. From P. fortinii cultures, a total of 15 quinone derivatives, comprising 11 new derivatives and 4 known compounds, were obtained. Among these compounds, palmarumycin P3 (3) and phialocephalarin B (8) specifically modulate the expression of MDR1 to inhibit the activity of drug efflux pumps and therefore reverse azole resistance. The present study revealed Mdr1 targeting as an alternative mechanism for the discovery of new agents to fight antifungal drug resistance. PMID:27650180

  10. In vitro activities of new and conventional antifungal agents against clinical Scedosporium isolates.

    PubMed

    Meletiadis, Joseph; Meis, Jacques F G M; Mouton, Johan W; Rodriquez-Tudela, Juan Luis; Donnelly, J Peter; Verweij, Paul E

    2002-01-01

    The susceptibilities of 13 clinical isolates of Scedosporium apiospermum and 55 clinical isolates of S. prolificans to new and conventional drugs belonging to three different classes of antifungal agents, the azoles (miconazole, itraconazole, voriconazole, UR-9825, posaconazole), the polyenes (amphotericin B, nystatin and liposomal nystatin), and allylamines (terbinafine), were studied by use of proposed standard M38-P of NCCLS. Low growth-inhibitory antifungal activities were found in vitro for most of the drugs tested against S. prolificans isolates, with the MICs at which 90% of isolates are inhibited (MIC(90)s) being >8 microg/ml; the MIC(90)s of voriconazole and UR-9825, however, were 4 microg/ml. S. apiospermum isolates were more susceptible in vitro, with the highest activity exhibited by voriconazole (MIC(90)s, 0.5 microg/ml), followed by miconazole (MIC(90)s, 1 microg/ml), UR-9825 and posaconazole (MIC(90)s, 2 microg/ml), and itraconazole (MIC(90)s, 4 microg/ml). The MICs of terbinafine, amphotericin B, and the two formulations of nystatin (for which no statistically significant differences in antifungal activities were found for the two species) for S. apiospermum isolates were high. Cross-resistance was observed among all the azoles except posaconazole and among all the polyenes except the lipid formulation. A distribution analysis was performed with the MICs of each drug and for each species. Bimodal and skewed MIC distributions were obtained, and cutoffs indicating the borders of different MIC subpopulations of the distributions were determined on the basis of the normal plot technique. These cutoffs were in many cases reproducible between 48 and 72 h.

  11. 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. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Analysis of current antifungal agents and their targets within the Pneumocystis carinii genome.

    PubMed

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

    2012-11-01

    Pneumocystis pneumonia (PCP) remains a leading opportunistic infection in patients with weakened immune systems. 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 are 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 the Pneumocystis Genome Project at http://pgp.cchmc.org/.

  13. 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.

  14. 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.

  15. Electrochemical behavior of the antifungal agents itraconazole, posaconazole and ketoconazole at a glassy carbon electrode.

    PubMed

    Knoth, H; Scriba, G K E; Buettner, B

    2015-06-01

    The electrochemical behavior of the azole antifungal agents itraconazole, posaconazole and ketoconazole has been investigated at a glassy carbon working electrode using cyclic voltammetry. All measurements were carried out in a supporting electrolyte solution consisting of a 1:1 (v/v) mixture of 0.1 mol L(-1) sodium phosphate buffers and acetonitrile at various substance concentrations and pH values. An amperometric cell with a three electrode system consisting of a working electrode, a palladium reference electrode and a platinum disk as the auxiliary electrode was used in all experiments. All azoles showed a similar electrochemical behavior involving two reactions. An irreversible oxidation occurred at potentials of about 0.5V. A reduction peak was detected at potentials between -0.28V and -0.14V with an associated oxidation peak, which was observed in consecutive repeated measurements at potentials between -0.03 and 0.28 V. The reduction and corresponding oxidation can be regarded as a quasi-reversible process. The proposed reaction mechanisms are an irreversible oxidation of the piperazine moiety at higher potentials as well as a reduction at lower potentials of the carbonyl group of the triazolone moiety in the case of itraconazole and posaconazole or a reduction of the methoxy group of ketoconazole.

  16. Monitoring Antifungal Resistance in a Global Collection of Invasive Yeasts and Moulds: Application of CLSI Epidemiological Cutoff Values and Whole Genome Sequencing Analysis for Detection of Azole Resistance in Candida albicans.

    PubMed

    Castanheira, Mariana; Deshpande, Lalitagauri M; Davis, Andrew P; Rhomberg, Paul R; Pfaller, Michael A

    2017-08-07

    The activity of 7 antifungal agents was evaluated against 3,557 invasive yeasts and moulds collected in 29 countries worldwide during 2014-2015. Epidemiological cutoff values (ECVs) published in the CLSI M59 document were applied for species with no clinical breakpoints. Echinocandin susceptibility rates were 95.9% to 100.0% for the 5 most common Candida species except anidulafungin and C. parapsilosis (88.7% susceptible/100.0% wild-type). Fluconazole resistance ranged from 8.0% for C. glabrata to 0.4% for C. albicans Seven Candida species displayed 100.0% wild-type amphotericin B and C. dubliniensis and C. lusitaniae exhibited wild-type echinocandin MIC results. The highest fluconazole, voriconazole, and posaconazole MIC values for Cryptococcus neoformansvar. grubii were 8 μg/mL, 0.12 μg/mL, and 0.25 μg/mL, respectively. A. fumigatus were 100.0% wild-type for caspofungin and amphotericin B, but 3 (0.8%) of these isolates were non- wild-type to itraconazole (2 isolates) or voriconazole (1 isolate). Mutations on FKS hotspots (HS) were detected among 13/20 Candida isolates (16/20 were C. glabrata) displaying echinocandin MIC>ECV. Most isolates carrying FKS HS mutations were resistant to 2 or more echinocandins. Five fluconazole-nonsusceptible C. albicans were submitted to whole genome sequencing analysis. Gain of function, Erg11 heterozygous, and Erg3 homozygous mutations were observed in 1 isolate each. One isolate displayed MDR1 promoter allele alterations associated with azole resistance. Elevated expression of MDR1 or CDR2 was observed among 3 and 1 isolates, respectively. Echinocandin and azole resistance is still uncommon among contemporary fungal isolates; however, resistance mechanisms to antifungals were observed among Candida spp. showing that resistance can emerge and monitoring is warranted. Copyright © 2017 American Society for Microbiology.

  17. 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

  18. 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

    2015-10-09

    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.

  19. In vitro antifungal susceptibility of coelomycete agents of black grain eumycetoma to eight antifungals.

    PubMed

    Ahmed, Sarah Abdalla; de Hoog, G Sybren; Stevens, David A; Fahal, Ahmed H; van de Sande, Wendy W J

    2015-04-01

    Fungal mycetoma (eumycetoma) represents one of the most difficult infections to appropriately manage. The current recommended treatment is based on extensive surgical debridement combined with prolonged antifungal therapy with ketoconazole or itraconazole. Despite the different phylogenetic positions of black-grain eumycetoma species, they are all treated with the same antifungal agents. The in vitro antifungal susceptibility of coelomycetous eumycetoma agents in the order of Pleosporales presently is largely unknown. Here we determined the in vitro activity of eight antifungal agents against seven species causing human eumycetoma using the Sensititre YeastOne method. High minimum inhibitory concentrations (MICs) were found with fluconazole, caspofungin, flucytosine, and amphotericin B. Voriconazole and posaconazole were found to be active against all species tested. Of the species included in the investigation, MICs of Medicopsis romeroi differed from the rest of the mycetoma causative agents belonging to the order of the Pleosporales. We found significantly lower MICs for amphotericin B and significantly higher MICs for fluconazole, ketoconazole, and itraconazole against this species. Our results emphasised that identification of black grain mycetoma agent is important as well as performing susceptibility testing before starting of antifungal treatment. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Susceptibility variation of Malassezia pachydermatis to antifungal agents according to isolate source

    PubMed Central

    Weiler, Caroline Borges; de Jesus, Francielli Pantella Kunz; Nardi, Graziela Habib; Loreto, Érico Silva; Santurio, Janio Morais; Coutinho, Selene Dall’Acqua; Alves, Sydney Hartz

    2013-01-01

    Malassezia pachydermatis is associated with dermatomycoses and otomycosis in dogs and cats. This study compared the susceptibility of M. pachydermatis isolates from sick (G1) and healthy (G2) animals to azole and polyene antifungals using the M27-A3 protocol. Isolates from G1 animals were less sensitive to amphotericin B, nystatin, fluconazole, clotrimazole and miconazole. PMID:24159302

  1. Identification of Candida species and susceptibility testing with Sensititre YeastOne microdilution panel to 9 antifungal agents.

    PubMed

    Kucukates, Emine; Gultekin, Nuh N; Alisan, Zeynep; Hondur, Nur; Ozturk, Recep

    2016-07-01

    To determine the species incidence and susceptibility pattern to 9 antifungal agents of yeasts isolated from various clinical specimens of colonized or infected patients treated in the coronary and surgical intensive care units (ICU).  A total of 421 ICU patients were treated at the Cardiology Institute, Istanbul University, Istanbul, Turkey between June 2013 and May 2014, and 44 Candida species were isolated from blood, urine, endotracheal aspiration fluid, sputum, and wounds of 16 ICU patients. Identification of Candida was performed using CHROMagar. Antifungal susceptibility was determined by a Sensititre YeastOne colorimetric microdilution panel.  Candida albicans (C. albicans) was the most commonly observed microorganism 23 (54%); the other microorganisms isolated were Candida tropicalis 12 (27%), Candida glabrata 5 (11%), Candida parapsilosis 1 (2%), Candida lusitaniae 1 (2%), Candida sake 1 (2%), and Geotrichum capitatum 1 (2%). All isolates were susceptible to amphotericin B and 5-flucytosine. Geotrichum capitatum excepted, the other isolates were also susceptible to anidulafungin, micafungin, and caspofungin. Candida parapsilosis was found to be susceptible to all the studied antifungals. High MIC rates for azole group of antifungal drugs were found for C. albicans, C. tropicalis, and C. glabrata. The rate of colonisation was 3.8% (16/421). Only 0.7% (3/421) patients out of a total of 421 developed candidemia.  We found that the yeast colonization and infection rates of patients in our ICUs are very low. Candida albicans is still the most common species. We detected a decreasing susceptibility to azole compounds.

  2. 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.

  3. Chemosensitization as a means to augment commercial antifungal agents

    USDA-ARS?s Scientific Manuscript database

    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...

  4. 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.

  5. Enhancement of commercial antifungal agents by kojic acid

    USDA-ARS?s Scientific Manuscript database

    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...

  6. 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.

  7. In vitro and in vivo antifungal profile of a novel and long acting inhaled azole, PC945, on Aspergillus fumigatus infection.

    PubMed

    Colley, Thomas; Alanio, Alexandre; Kelly, Steven L; Sehra, Gurpreet; Kizawa, Yasuo; Warrilow, Andrew G S; Parker, Josie E; Kelly, Diane E; Kimura, Genki; Anderson-Dring, Lauren; Nakaoki, Takahiro; Sunose, Mihiro; Onions, Stuart; Crepin, Damien; Lagasse, Franz; Crittall, Matthew; Shannon, Jonathan; Cooke, Michael; Bretagne, Stéphane; King-Underwood, John; Murray, John; Ito, Kazuhiro; Strong, Pete; Rapeport, Garth

    2017-02-21

    The profile of PC945, a novel triazole antifungal, designed for administration via inhalation, has been assessed in a range of in vitro and in vivo studies. PC945 was characterized as a potent, tight-binding inhibitor of Aspergillus fumigatus sterol 14α-demethylase (CYP51A and CYP51B) activity (IC50, 0.23 μM and 0.22 μM, respectively), with characteristic type II azole binding spectra. Against 96 clinically isolated A. fumigatus strains, the MIC values of PC945 ranged from 0.032∼>8 μg/ml, whilst those of voriconazole ranged from 0.064∼4 μg/ml. Spectrophotometric analysis of the effects of PC945 against itraconazole-susceptible and -resistant A. fumigatus growth, yielded IC50 (OD) values between 0.0012∼0.034 μg/ml, whereas voriconazole (0.019∼>1 μg/ml) was less effective than PC945. PC945 was effective against a broad spectrum of pathogenic fungi (MIC ranged from 0.0078∼2 μg/ml) including Aspergillus terreus, Trichophyton rubrum, Candida albicans, Candida glabrata, Candida krusei, Cryptococcus gattii, Cryptococcus neoformans andRhizopus oryzae (1∼2 isolates each). In addition, when A. fumigatus hyphae or human bronchial cells were treated with PC945, and then washed, PC945 was found to be quickly absorbed into both target and non-target cells and to produce persistent antifungal effects. In temporarily neutropenic immunocompromised mice infected with A. fumigatus intranasally, 50% of the animals survived until day 7 when treated intranasally with PC945 at 0.56 μg/mouse, while posaconazole showed similar effects (44%) at 14 μg/mouse. This profile affirms that topical treatment with PC945 should provide potent antifungal activity in the lung.

  8. 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.

  9. Use of Antifungal Combination Therapy: Agents, Order, and Timing

    PubMed Central

    Perfect, John R.

    2010-01-01

    Given the substantial morbidity and mortality related to invasive fungal infections, treatment with a combination of antifungal agents is often considered. A growing body of literature from in vitro studies, animal models, and clinical experience provides data evaluating this approach. This review describes combination antifungal strategies for the management of cryptococcal meningitis, invasive candidiasis, invasive aspergillosis, and rare mold infections. The potential effects that sequencing and timing have on the efficacy of such approaches are discussed, with a focus on recent clinical data in this arena. PMID:20574543

  10. Azole resistance in Candida albicans.

    PubMed

    Smith, K J; Warnock, D W; Kennedy, C T; Johnson, E M; Hopwood, V; Van Cutsem, J; Vanden Bossche, H

    1986-04-01

    An isolate of Candida albicans from a patient with chronic mucocutaneous candidosis who relapsed during ketoconazole treatment was compared with a number of other azole-sensitive and azole-resistant isolates by tests in vitro and in three animal models of vaginal or disseminated infection. In-vitro tests indicated that the isolate was cross-resistant to all imidazole and triazole antifungals tested. In the animal models, treatment with miconazole, ketoconazole, itraconazole or fluconazole failed to influence the infection.

  11. The biology and chemistry of antifungal agents: a review.

    PubMed

    Kathiravan, Muthu K; Salake, Amol B; Chothe, Aparna S; Dudhe, Prashik B; Watode, Rahul P; Mukta, Maheshwar S; Gadhwe, Sandeep

    2012-10-01

    In recent years their has been an increased use of antifungal agents and has resulted in the development of resistance to drugs. Currently, use of standard antifungal therapies can be limited because of toxicity, low efficacy rates. Different types of mechanisms contribute to the development of resistance to antifungals. This has given raise to search for a new heterocycle with distinct action or multitargeted combination therapy. This review addresses the areas such as the underlying mechanisms, eight different targets such as ergosterol synthesis, chitin synthesis, ergosterol disruptors, glucan synthesis, squalene epoxidase, nucleic acid synthesis, protein synthesis, microtubules synthesis. The clinically employed drugs along with the current research work going on worldwide on different heterocycles are discussed. In recent advances various heterocycles including imidazole, benzimidazole etc., twenty three scaffolds and their lead identification are discussed.

  12. Natural products--antifungal agents derived from plants.

    PubMed

    Arif, Tasleem; Bhosale, J D; Kumar, Naresh; Mandal, T K; Bendre, R S; Lavekar, G S; Dabur, Rajesh

    2009-07-01

    A new spectrum of human fungal infections is increasing due to increased cancer, AIDS, and immunocompromised patients. The increased use of antifungal agents also resulted in the development of resistance to the present drugs. It makes necessary to discover new classes of antifungal compounds to cure fungal infections. Plants are rich source of bioactive secondary metabolites of wide variety such as tannins, terpenoids, saponins, alkaloids, flavonoids, and other compounds, reported to have in vitro antifungal properties. Since the plant kingdom provides a useful source of lead compounds of novel structure, a wide-scale investigation of species from the tropics has been considered. Therefore, the research on natural products and compounds derived from natural products has accelerated in recent years due to their importance in drug discovery. A series of molecules with antifungal activity against different strains of fungus have been found in plants, which are of great importance to humans. These molecules may be used directly or considered as a precursor for developing better molecules. This review attempts to summarize the current status of important antifungal compounds from plants.

  13. Prophylactic systemic antifungal agents to prevent mortality and morbidity in very low birth weight infants.

    PubMed

    Cleminson, Jemma; Austin, Nicola; McGuire, William

    2015-10-24

    Invasive fungal infection is an important cause of mortality and morbidity in very preterm and very low birth weight infants. Early diagnosis is difficult and treatment is often delayed. Systemically absorbed antifungal agents (usually azoles) are increasingly used as prophylaxis against invasive fungal infection in this population. To assess the effect of prophylactic systemic antifungal therapy on mortality and morbidity in very preterm or very low birth weight infants. We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2015, Issue 8), MEDLINE, EMBASE, and CINAHL (to May 2015), conference proceedings, and previous reviews. Randomised controlled trials or quasi-randomised controlled trials that compared the effect of prophylactic systemic antifungal therapy versus placebo or no drug or another antifungal agent or dose regimen in very low birth weight infants. We extracted data using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by two review authors. We identified 15 eligible trials enrolling a total of 1690 infants. Ten trials (1371 infants) compared systemic antifungal prophylaxis versus placebo or no drug. These trials were generally of good methodological quality. Meta-analysis found a statistically significant reduction in the incidence of invasive fungal infection (typical risk ratio (RR) 0.43, 95% confidence interval (CI) 0.31 to 0.59; risk difference (RD) -0.09, 95% CI -0.12 to -0.06). The average incidence of invasive fungal infection in the control groups of the trials (16%) was much higher than that generally reported from large cohort studies. Meta-analysis did not find a statistically significant difference in the risk of death prior to hospital discharge (typical RR 0.79, 95% CI 0.61 to 1.02; typical RD -0.04, 95% CI -0.07 to 0.00). Very

  14. Antifungal relative inhibition factors: BAY l-9139, bifonazole, butoconazole, isoconazole, itraconazole (R 51211), oxiconazole, Ro 14-4767/002, sulconazole, terconazole and vibunazole (BAY n-7133) compared in vitro with nine established antifungal agents.

    PubMed

    Odds, F C; Webster, C E; Abbott, A B

    1984-08-01

    Nine new antifungal agents were tested for their activity in vitro in terms of relative inhibition factors (RIFs) against 26 isolates of Candida species, eight isolates of Aspergillus species and six isolates of dermatophyte fungi. Eight of the new compounds were azole antifungals, the ninth was a phenylmorpholine derivative. Against Candida species, all the novel compounds gave RIFs that were of a similar order to RIFs for established imidazole compounds. Two topical antifungals, butoconazole and terconazole, and two systemic antifungals, itraconazole and vibunazole, gave mean RIFs less than 60% in tests with Candida species, and therefore matched clotrimazole, ketoconazole and tioconazole in terms of RIF. However, none of the new compounds gave RIFs as low as amphotericin B against the Candida isolates. Against Aspergillus isolates, itraconazole, with a mean RIF of 25%, was even more active in vitro than amphotericin B. Vibunazole was as active as ketoconazole against Aspergillus isolates. All the new antifungals except Bay l-9139 gave very low RIFs against dermatophyte isolates, and thus matched established imidazole antifungals for inhibitory effects in vitro. In terms of RIF data, all the nine new compounds tested appear to offer reasonable potential for antifungal chemotherapy in vivo. A similar conclusion would not have been drawn from minimal inhibitory concentration data, which tended to show most of the new antifungals in a very poor light. Tests with amphotericin B, 5-fluorocytosine and ketoconazole showed that RIF can vary substantially with the pH of the test medium. For amphotericin B and ketoconazole the best activity was seen at neutral pH values; for 5-fluorocytosine the greatest inhibitory activity was found at lower pH values.

  15. Investigation of the Sterol Composition and Azole Resistance in Field Isolates of Septoria tritici

    PubMed Central

    Joseph-Horne, T.; Hollomon, D.; Manning, N.; Kelly, S. L.

    1996-01-01

    We report here a biochemical study of resistance to azole antifungal agents in a field isolate (S-27) of a fungal phytopathogen. Isolates of Septoria tritici were compared in vitro, and their responses reflected that observed in the field, with S-27 exhibiting resistance relative to RL2. In untreated cultures, both RL2 and S-27 contained isomers of ergosterol and ergosta-5,7-dienol, although in differing concentrations. Under azole treatment, this phytopathogen exhibited a response similar to that of other pathogenic fungi, with a reduction in desmethyl sterols and an accumulation of 14(alpha)-methyl sterols, indicative of inhibition of the P450-mediating sterol 14(alpha)-demethylase. Growth arrest was attributed to the reduction of ergosterol combined with an accumulation of nonutilizable sterols. Strain S-27 exhibited an azole-resistant phenotype which was correlated with decreased cellular content of azole. PMID:16535210

  16. Effects of antifungal agents in sap activity of Candida albicans isolates.

    PubMed

    Costa, Carolina Rodrigues; Jesuíno, Rosália Santos Amorim; de Aquino Lemos, Janine; de Fátima Lisboa Fernandes, Orionalda; Hasimoto e Souza, Lúcia Kioko; Passos, Xisto Sena; do Rosário Rodrigues Silva, Maria

    2010-02-01

    Some antifungal agents have shown to exert effects on expression of virulent factors of Candida as the production of secretory aspartyl proteinase (Sap). In this study, we sought to determine and to compare the influence of fluconazole and voriconazole in proteinase activity of this microorganism. Thirty-one isolates obtained from oral mucosa of human immunodeficiency virus positive (HIV) patients were used in this study. The minimal inhibitory concentrations (MIC) of fluconazole and voriconazole were determined using the broth microdilution method with RPMI 1640 medium and with yeast carbon base-bovine serum albumin (YCB-BSA) medium. The Sap activity following by digestion of BSA as substrate was determined for four Candida albicans strains arbitrarily chosen according to susceptibility (susceptible or resistant) to fluconazole or voriconazole. Besides, the SAP1 to SAP7 genes were screened by PCR for the same isolates that were determined by the Sap activity. In vitro susceptibility testing using the two media presented similar MIC values. Increased Sap activity was observed in resistant isolates on presence of drugs, but the Sap activity by susceptible isolates to azoles showed different behavior on the presence of drug. We detected the presence of SAP1 to SAP7 genes from all susceptible or resistant C. albicans isolates. The present study provides important data about the proteinase activity and the presence of genes of SAP family in fluconazole and voriconazole susceptible or resistant C. albicans isolates.

  17. Neosordarin and hydroxysordarin, two new antifungal agents from Sordaria araneosa.

    PubMed

    Davoli, Paolo; Engel, Günther; Werle, Andreas; Sterner, Olov; Anke, Timm

    2002-04-01

    Two novel antifungal agents belonging to the sordarin family have been isolated from fermentations of Sordaria araneosa by bioassay-guided purification and their structures elucidated by NMR techniques. Neosordarin (1) is closely related to the recently discovered hypoxysordarin (2), with only small differences on the aliphatic side chain acylating the hydroxyl in the 3'-position of the sordarose moiety. Hydroxysordarin (3) closely resembles sordarin (4), the only slight difference being the replacement of sordarose with altrose as the sugar unit.

  18. Susceptibilities of Candida albicans mouth isolates to antifungal agents, essentials oils and mouth rinses.

    PubMed

    Carvalhinho, Sara; Costa, Ana Margarida; Coelho, Ana Cláudia; Martins, Eugénio; Sampaio, Ana

    2012-07-01

    Forty Candida albicans strains isolated from patient's mouth with fixed orthodontic appliances were analyzed to their susceptibilities to antifungal agents, mouth rinses and essential oils. Susceptibility to fluconazole, econazole, miconazole and ketoconazole, amphotericin B and nystatin was assessed by the disk diffusion (DD) method based on the Clinical and Laboratory Standards Institute M44-A protocol, and by Etest (fluconazole and amphotericin B). The susceptibilities to mouth rinses and essential oils were also determined by the DD technique. All isolates tested were susceptible (S) to amphotericin B, nystatin and fluconazole. The overall concordance between the DD and the Etest was 100% for amphotericin and fluconazole. One isolate was resistant to econazole (2.5%) and the other to ketoconazole (2.5%). Econazole and ketoconazole had the highest percentages of susceptible dose dependent (SDD), 55 and 95%, respectively. Regarding to the susceptibility isolates profile, seven phenotypes were detected, and the 3 more represented (90% of the isolates) of them were SDD to one, two or three azoles. The study of mouth rinses showed a high variability of efficacy against C. albicans. The results showed that the isolates susceptibility to essential oils differed (P < 0.05). The profile activity was: cinnamon > laurel > mint > eucalyptus > rosemary > lemon > myrrh > tangerine. The main finding was that the susceptibility to cinnamon and laurel varied among the three more representative antifungal phenotypes (P < 0.05). The susceptibility of econazole-SDD isolates to cinnamon and lemon was higher than those of the econazole-S yeasts (P < 0.05). In contrast, econazole-SDD isolates were less affected by laurel than econazole-S counterparts (P < 0.05).

  19. Phytochemicals from Cunninghamia konishii Hayata act as antifungal agents.

    PubMed

    Cheng, Sen-Sung; Chung, Min-Jay; Lin, Chun-Ya; Wang, Ya-Nan; Chang, Shang-Tzen

    2012-01-11

    The aims of the present study were to isolate and identify the antifungal compounds from the ethanolic extract of Cunninghamia konishii wood and to evaluate their antifungal activities against wood decay fungi. The results showed that the n-Hex soluble fraction of the ethanolic extract from C. konishii wood had an excellent inhibitory effect against Lenzites betulina, Trametes versicolor, Laetiporus sulphureus, and Gloeophyllum trabeum, with IC(50) values of 33, 46, 62, and 49 μg/mL, respectively. By following the bioactivity-guided fractionation procedure, four sesquiterpenes, T-cadinol, cedrol, T-muurolol, and (-)-epi-cedrol, and three diterpenes, 13-epi-manool, cis-abienol, and isoabienol, were identified from the active subfractions. Among the main constituents of the ethanolic extract from C. konishii, T-cadinol, cedrol, and T-muurolol efficiently inhibited the growth of four wood-rot fungi at the concentration of 100 μg/mL, with antifungal indices of 51.4-100.0%, 68.3-100.0%, and 39.5-100.0%, respectively. Results of this study show that the ethanolic extract of C. konishii wood may be considered as a potent source of T-cadinol, cedrol, and T-muurolol as new natural antifungal agents.

  20. Antifungal Microbial Agents for Food Biopreservation-A Review.

    PubMed

    Leyva Salas, Marcia; Mounier, Jérôme; Valence, Florence; Coton, Monika; Thierry, Anne; Coton, Emmanuel

    2017-07-08

    Food spoilage is a major issue for the food industry, leading to food waste, substantial economic losses for manufacturers and consumers, and a negative impact on brand names. Among causes, fungal contamination can be encountered at various stages of the food chain (e.g., post-harvest, during processing or storage). Fungal development leads to food sensory defects varying from visual deterioration to noticeable odor, flavor, or texture changes but can also have negative health impacts via mycotoxin production by some molds. In order to avoid microbial spoilage and thus extend product shelf life, different treatments-including fungicides and chemical preservatives-are used. In parallel, public authorities encourage the food industry to limit the use of these chemical compounds and develop natural methods for food preservation. This is accompanied by a strong societal demand for 'clean label' food products, as consumers are looking for more natural, less severely processed and safer products. In this context, microbial agents corresponding to bioprotective cultures, fermentates, culture-free supernatant or purified molecules, exhibiting antifungal activities represent a growing interest as an alternative to chemical preservation. This review presents the main fungal spoilers encountered in food products, the antifungal microorganisms tested for food bioprotection, and their mechanisms of action. A focus is made in particular on the recent in situ studies and the constraints associated with the use of antifungal microbial agents for food biopreservation.

  1. Antifungal Microbial Agents for Food Biopreservation—A Review

    PubMed Central

    Leyva Salas, Marcia; Mounier, Jérôme; Coton, Monika; Thierry, Anne; Coton, Emmanuel

    2017-01-01

    Food spoilage is a major issue for the food industry, leading to food waste, substantial economic losses for manufacturers and consumers, and a negative impact on brand names. Among causes, fungal contamination can be encountered at various stages of the food chain (e.g., post-harvest, during processing or storage). Fungal development leads to food sensory defects varying from visual deterioration to noticeable odor, flavor, or texture changes but can also have negative health impacts via mycotoxin production by some molds. In order to avoid microbial spoilage and thus extend product shelf life, different treatments—including fungicides and chemical preservatives—are used. In parallel, public authorities encourage the food industry to limit the use of these chemical compounds and develop natural methods for food preservation. This is accompanied by a strong societal demand for ‘clean label’ food products, as consumers are looking for more natural, less severely processed and safer products. In this context, microbial agents corresponding to bioprotective cultures, fermentates, culture-free supernatant or purified molecules, exhibiting antifungal activities represent a growing interest as an alternative to chemical preservation. This review presents the main fungal spoilers encountered in food products, the antifungal microorganisms tested for food bioprotection, and their mechanisms of action. A focus is made in particular on the recent in situ studies and the constraints associated with the use of antifungal microbial agents for food biopreservation. PMID:28698479

  2. Antifungal pharmacodynamics: Latin America's perspective.

    PubMed

    Gonzalez, Javier M; Rodriguez, Carlos A; Agudelo, Maria; Zuluaga, Andres F; Vesga, Omar

    The current increment of invasive fungal infections and the availability of new broad-spectrum antifungal agents has increased the use of these agents by non-expert practitioners, without an impact on mortality. To improve efficacy while minimizing prescription errors and to reduce the high monetary cost to the health systems, the principles of pharmacokinetics (PK) and pharmacodynamics (PD) are necessary. A systematic review of the PD of antifungals agents was performed aiming at the practicing physician without expertise in this field. The initial section of this review focuses on the general concepts of antimicrobial PD. In vitro studies, fungal susceptibility and antifungal serum concentrations are related with different doses and dosing schedules, determining the PD indices and the magnitude required to obtain a specific outcome. Herein the PD of the most used antifungal drug classes in Latin America (polyenes, azoles, and echinocandins) is discussed. Copyright © 2016 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

  3. Development and validation of a High Resolution Melting Assay to detect azole resistance in Aspergillus fumigatus.

    PubMed

    Bernal-Martínez, L; Gil, H; Rivero-Menéndez, O; Gago, S; Cuenca-Estrella, M; Mellado, E; Alastruey-Izquierdo, A

    2017-09-11

    The global emergence of azole resistant Aspergillus fumigatus strains is a growing public health concern. Different patterns of azole resistance are linked to mutations in cyp51A. Therefore, an accurate characterization of the mechanisms underlying azole resistance is critical to guide selection of the most appropriate antifungal agent in patients with aspergillosis. This study describes a new sequencing-free molecular screening tool for the early detection of the most frequent mutations known to be associated with azole resistance in A. fumigatus PCRs targeting cyp51A mutations at positions G54, Y121, G448 and M220 and the promoter region targeting the different tandem repeats (TR) were designed. All PCRs were simultaneously performed using the same cycling conditions. Amplicons were then distinguished using a High Resolution Melting assay. For standardization, 30 well-characterized azole resistant A. fumigatus strains were used, obtaining melting curve clusters for different resistance mechanisms in each target and detecting the most frequent azole-resistance mutations: G54E, G54V, G54R, G54W, Y121F, M220V, M220I, M220T, M220K, G448S and the tandem repeats, TR34, TR46 and TR53 Validation of the method was performed using a blind panel of 80 A. fumigatus azole susceptible and resistant strains. All strains included in the blind panel were properly classified as susceptible or resistant by the developed method. The implementation of this screening method can reduce the time for the detection of azole resistant A. fumigatus isolates and therefore facilitate the selection of the best antifungal therapy in patients with aspergillosis. Copyright © 2017 American Society for Microbiology.

  4. Trends in the utilization of, spending on, and prices for outpatient antifungal agents in US Medicaid programs: 1991-2009.

    PubMed

    Desai, Vibha C A; Cavanaugh, Teresa M; Kelton, Christina M L; Guo, Jeff J; Heaton, Pamela C

    2012-10-01

    The incidence of invasive fungal infections (IFIs) has increased substantially in the recent past. Advances in medical technology, including broad-spectrum antibiotics, may increase the risk for fungal infections. Moreover, immunocompromised patients with cancer, HIV/AIDS, and/or transplants are susceptible to IFIs. Meanwhile, superficial fungal infections (SFIs) are common and can be difficult to cure. To provide a historical perspective on a dynamic market with expensive medications, this study describes trends in the utilization of, spending on, and average per-prescription spending on outpatient antifungal medications individually, in classes (for IFIs or SFIs), and overall, by the US Medicaid programs from 1991 to 2009. The publicly available Medicaid State Drug Utilization Data, maintained by the Centers for Medicare & Medicaid Services, were used. Annual prescription counts and reimbursement amounts were calculated for each of the antifungals reimbursed by Medicaid. Average per-prescription spending as a proxy for drug price was calculated by dividing reimbursement by the number of prescriptions. Overall utilization for Medicaid beneficiaries remained steady, with 4.56 million prescriptions in 1991 and 4.51 million in 2009. Expenditures rose from $93.87 million to $143.76 million (in current-year US$) over the same time period. The drop in the utilization of first-generation azoles over the last 5 years of the study period can be explained in part by the movement of dual-eligibles from Medicaid to Medicare Part D and in part to a rise in fungal infections better treated with second-generation azoles or echinocandins. Whereas the average per-prescription price for generic (oral) fluconazole was $8 in 2009, the price per prescription of branded (intravenous) voriconazole was $2178. Overall spending by Medicaid on outpatient antifungal medications increased more slowly than did the growth of the Medicaid programs from 1991 to 2009. However, the utilization of

  5. 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.

  6. Quercetin and rutin as potential agents antifungal against Cryptococcus spp.

    PubMed

    Oliveira, V M; Carraro, E; Auler, M E; Khalil, N M

    2016-01-01

    Amphotericin B is a fungicidal substance that is treatment of choice for most systemic fungal infections affecting as cryptococcosis the immunocompromised patients. However, severe side effects have limited the utility of this drug. The aim of this study was to evaluate the antifungal effect of the combination of amphotericin B with quercetin or rutin and as a protective of citotoxic effect. The antifungal activity to amphotericin B, quercetin and rutin alone and in combination was determined in Candida sp and Cryptococcus neoformans strains. Cytotoxicity test on erythrocytes was performed by spectrophotometric absorbance of hemoglobin. The amphotericin B MIC was reduced when used in combination with quercetin or rutin to C. neoformans ATCC strain and reduced when combined with rutin to a clinical isolate of C. neoformans. In addition, the combination of quercetin with amphotericin B may reduce the toxicity of amphotericin B to red blood cells. Our results suggest that quercetin and rutin are potential agents to combine with amphotericin B in order to reduce the amphotericin dose to lessen side effects and improve antifungal efficacy.

  7. An automated method for the simultaneous measurement of azole antifungal drugs in human plasma or serum using turbulent flow liquid chromatography-tandem mass spectrometry.

    PubMed

    Couchman, L; Buckner, S L; Morgan, P E; Ceesay, M M; Pagliuca, A; Flanagan, R J

    2012-08-01

    Azole antifungal drugs are important in the prophylaxis and treatment of invasive aspergillosis. Therapeutic drug monitoring may be indicated to (1) monitor adherence, (2) guide dosage and (3) minimise the risk of drug-drug interactions and dose-related toxicity. TurboFlow(TM) technology offers online, automated sample preparation. An Aria Transcend(TM) TLX-II coupled with a TSQ Vantage(TM) MS was used. Centrifuged samples (25 μL) were mixed with internal standard solution (975 μL) and 30 μL injected directly onto a C18-P-XL TurboFlow column. Analytes were focussed onto a Phenomenex Gemini Phenyl analytical column and eluted using a methanol/water gradient (flow-rate, 0.8 mL/min). Analytes were monitored in selected reaction monitoring mode (two transitions per analyte, positive mode APCI). Calibration ranges were as follows: itraconazole, hydroxyitraconazole, and posaconazole 0.05-5.0 mg/L; voriconazole and fluconazole 0.1-10 mg/L. Total analysis time was 12 min. TurboFlow column recovery was >77% for all analytes. Calibration was linear (R (2) > 0.99) for all analytes. Inter- and intra-assay imprecision (% RSD) was <8% and accuracy (nominal internal quality control values) 90-105% for all analytes. The limit of detection was 0.01 mg/L for all analytes. No matrix effects were observed. This method is simple, robust and suitable for measuring these compounds at concentrations attained during therapy.

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

    PubMed

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

    2014-05-01

    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.

  9. 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

  10. Antifungal Resistance, Metabolic Routes as Drug Targets, and New Antifungal Agents: An Overview about Endemic Dimorphic Fungi.

    PubMed

    Parente-Rocha, Juliana Alves; Bailão, Alexandre Melo; Amaral, André Correa; Taborda, Carlos Pelleschi; Paccez, Juliano Domiraci; Borges, Clayton Luiz; Pereira, Maristela

    2017-01-01

    Diseases caused by fungi can occur in healthy people, but immunocompromised patients are the major risk group for invasive fungal infections. Cases of fungal resistance and the difficulty of treatment make fungal infections a public health problem. This review explores mechanisms used by fungi to promote fungal resistance, such as the mutation or overexpression of drug targets, efflux and degradation systems, and pleiotropic drug responses. Alternative novel drug targets have been investigated; these include metabolic routes used by fungi during infection, such as trehalose and amino acid metabolism and mitochondrial proteins. An overview of new antifungal agents, including nanostructured antifungals, as well as of repositioning approaches is discussed. Studies focusing on the development of vaccines against antifungal diseases have increased in recent years, as these strategies can be applied in combination with antifungal therapy to prevent posttreatment sequelae. Studies focused on the development of a pan-fungal vaccine and antifungal drugs can improve the treatment of immunocompromised patients and reduce treatment costs.

  11. Terconazole--a new antifungal agent for vulvovaginal candidiasis.

    PubMed

    Weisberg, M

    1989-01-01

    Terconazole is a new broad-spectrum antifungal agent for the treatment of vulvovaginal candidiasis. Instead of an imidazole structure, terconazole contains a triazole ring, a structure developed specifically to improve antifungal activity. Clinical studies of this antifungal agent have involved 5,500 women worldwide and a number of terconazole formulations, including 80-mg vaginal suppositories and 0.4% vaginal cream. The highlights of several large, major studies are discussed in this review article. In European studies, mycologic cure rates for terconazole regimens approached or exceeded 90%. Speed of action was rapid, and relapse rates were low. In double-blind, multicenter studies conducted in the United States, clinical cure rates for 0.4% terconazole cream ranged from 86% to 96% and microbiologic cure rates from 77% to 91% at 8 to 10 days after therapy. Most patients remained free of positive signs and symptoms and microbiologic evidence of infection at 30 to 35 days posttherapy. Symptomatic relief tended to be more rapid for patients treated with 0.4% terconazole cream than for those treated with 2.0% miconazole nitrate cream. In US studies of 80-mg terconazole suppositories, clinical cure rates 8 to 10 days after therapy were between 89% and 92%, and microbiologic cure rates were between 80% and 85%. Relapse rates were also low with this form of therapy. No statistically significant differences were found between three days of treatment with 80-mg terconazole suppositories and seven days of treatment with 100-mg miconazole nitrate suppositories. This research demonstrates that terconazole is a fast-acting, highly effective, well-tolerated therapy for vulvovaginal candidiasis.

  12. In vitro interaction between amphotericin B and azoles in Candida albicans.

    PubMed Central

    Vazquez, J A; Arganoza, M T; Vaishampayan, J K; Akins, R A

    1996-01-01

    The use of azole prophylaxis as a measure to prevent invasive fungal infections in high-risk patients is increasing and is now the standard of care in many institutions. Previous studies disagree on whether preexposure of Candida albicans to azoles affects their subsequent susceptibility to amphotericin B (AmB). The present in vitro study indicates that azole exposure generates a subpopulation of cells that are not affected by subsequent exposure to AmB. These cells that are phenotypically resistant to AmB tolerated by most cells not exposed to azole. The percentage of cells that convert to phenotypic resistance to AmB varies with the concentration and the azole. Itraconazole is more effective than fluconazole in generating cells that are phenotypically resistant to AmB and that tolerate an otherwise lethal transient exposure to AmB. Until cells that are not exposed to fluconazole are simultaneously challenged with AmB, they are not protected to a significant extent from killing by AmB. Cells that are challenged with continuous exposure to AmB also acquire phenotypic resistance to AmB at increased frequencies by azole preexposure, but this requires that the azole be continuously present during incubation with AmB. In addition, Candida cells taken from mature colonies that are not actively growing are not susceptible to the short-term killing effects of AmB without azole preexposure. The adaptive responses of C. albicans to AmB and potentially other antifungal agents that may result from prior exposure to azoles in vitro or potentially in microenvironments in vivo that induce physiological changes may have major clinical implications. PMID:8913455

  13. Treatment of dermatophytosis by a new antifungal agent 'apigenin'.

    PubMed

    Singh, Geeta; Kumar, Padma; Joshi, Suresh Chandra

    2014-08-01

    Dermatophytes are the most common causative agents of cutaneous mycosis and remain a major public health problem in spite of the availability of an increasing number of antifungal drugs. It was, therefore considered necessary to pursue the screening of different extracts (compounds) of selected traditional medicinal plants reportedly having antidermatophyte potential. The aim of this study was to isolate and identify specific compound from the most active extract (free flavonoid) of stem of Terminalia chebula of the selected plants to treat dermatophytosis induced on experimental mice. Mice which were experimentally induced with Trichophyton mentagrophytes were grouped in six of five animals each. To treat the lesions on infected mice, two concentrations of isolated apigenin ointment, i.e. 2.5 mg g(-1) (Api I) and 5 mg g(-1) (Api II), and terbinafine (standard) of concentration 5 mg g(-1) were used. Complete recovery from the infection was recorded on 12th day of treatment for reference drug Terbinafine and Api II (5 mg g(-1) ) concentration of ointment, whereas Api I (2.5 mg g(-1) ) ointment showed complete cure on 16th day of treatment. Fungal burden was also calculated by culturing skin scraping from infected mice's of different groups. Apigenin has shown potency as the infected animals recover completely by Api II comparable to the standard drug in 12th day. So Apigenin can be explored as an antifungal agent in the clinical treatment of dermatophytosis in future.

  14. Roles of Calcineurin and Crz1 in Antifungal Susceptibility and Virulence of Candida glabrata▿

    PubMed Central

    Miyazaki, Taiga; Yamauchi, Shunsuke; Inamine, Tatsuo; Nagayoshi, Yosuke; Saijo, Tomomi; Izumikawa, Koichi; Seki, Masafumi; Kakeya, Hiroshi; Yamamoto, Yoshihiro; Yanagihara, Katsunori; Miyazaki, Yoshitsugu; Kohno, Shigeru

    2010-01-01

    A Candida glabrata calcineurin mutant exhibited increased susceptibility to both azole antifungal and cell wall-damaging agents and was also attenuated in virulence. Although a mutant lacking the downstream transcription factor Crz1 displayed a cell wall-associated phenotype intermediate to that of the calcineurin mutant and was modestly attenuated in virulence, it did not show increased azole susceptibility. These results suggest that calcineurin regulates both Crz1-dependent and -independent pathways depending on the type of stress. PMID:20100876

  15. Potent Antifungal Activity of Pure Compounds from Traditional Chinese Medicine Extracts against Six Oral Candida Species and the Synergy with Fluconazole against Azole-Resistant Candida albicans

    PubMed Central

    Yan, Zhimin; Hua, Hong; Xu, Yanying; Samaranayake, Lakshman P.

    2012-01-01

    This study was designed to evaluate the in vitro antifungal activities of four traditional Chinese medicine (TCM) extracts. The inhibitory effects of pseudolaric acid B, gentiopicrin, rhein, and alion were assessed using standard disk diffusion and broth microdilution assays. They were tested against six oral Candida species, Candida albicans, Candida glabrata, Candida tropicalis, Candida krusei, Candida dubliniensis, and Candida guilliermondii, including clinical isolates from HIV-negative, HIV-positive, and Sjögren's syndrome patients. It was found that pseudolaric acid B had the most potent antifungal effect and showed similar antifungal activity to all six Candida spp, and to isolates from HIV-negative, HIV-positive, and Sjögren's syndrome patients. The MIC values ranged from 16 to 128 μg/mL. More interestingly, a synergistic effect of pseudolaric acid B in combination with fluconazole was observed. We suggest that pseudolaric acid B might be a potential therapeutic fungicidal agent in treating oral candidiasis. PMID:22454653

  16. 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

  17. 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

    Bang, Soohyun; Kwon, Hyojeong; 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.

  18. Antifungal pharmacokinetics and pharmacodynamics.

    PubMed

    Lepak, Alexander J; Andes, David R

    2014-11-10

    Successful treatment of infectious diseases requires choice of the most suitable antimicrobial agent, comprising consideration of drug pharmacokinetics (PK), including penetration into infection site, pathogen susceptibility, optimal route of drug administration, drug dose, frequency of administration, duration of therapy, and drug toxicity. Antimicrobial pharmacokinetic/pharmacodynamic (PK/PD) studies consider these variables and have been useful in drug development, optimizing dosing regimens, determining susceptibility breakpoints, and limiting toxicity of antifungal therapy. Here the concepts of antifungal PK/PD studies are reviewed, with emphasis on methodology and application. The initial sections of this review focus on principles and methodology. Then the pharmacodynamics of each major antifungal drug class (polyenes, flucytosine, azoles, and echinocandins) is discussed. Finally, the review discusses novel areas of pharmacodynamic investigation in the study and application of combination therapy.

  19. Unusual Antimicrotubule Activity of the Antifungal Agent Spongistatin 1

    PubMed Central

    Ovechkina, Yulia Y.; Pettit, Robin K.; Cichacz, Zbigniew A.; Pettit, George R.; Oakley, Berl R.

    1999-01-01

    Spongistatin 1, a macrocyclic lactone from the marine sponge Hyrtios erecta, has broad-spectrum antifungal activity. Since this compound is a potent antimicrotubule agent in mammalian cells, we examined its effects on the filamentous fungus Aspergillus nidulans to determine if its antifungal effects are due to antimicrotubule activity. At 25 μg/ml (twice the MIC), spongistatin 1 caused a greater-than-twofold elevation of the chromosome and spindle mitotic indices. Immunofluorescence microscopy revealed that mitotic spindles were smaller and shorter than in control germlings. However, late-anaphase and telophase nuclei were seen occasionally, and this suggests that the spindles are capable of segregating chromosomes. Spongistatin 1 had more dramatic effects on cytoplasmic microtubules. At 30 min after initiation of treatment, 83% of germlings contained fragmented microtubules and after 2 h of treatment, microtubules had disappeared completely from 82% of germlings. In contrast, microtubules disappeared rapidly and completely from germlings treated with benomyl. We conclude that spongistatin 1 has antimicrotubule activity in A. nidulans and that its mechanism of action may involve a novel microtubule-severing activity. PMID:10428925

  20. Scaling adult doses of antifungal and antibacterial agents to children.

    PubMed

    Dawson, Thomas H

    2012-06-01

    My general pharmacokinetic scaling theory is discussed for the important matter of determining pediatric dosing for existing and new therapeutic drugs when optimal, or near-optimal, dosing for adults is known. The basis for the scaling is the requirement of a time-scaled likeness of the free-drug concentration time histories of children and adults. Broad categories of single and periodic dosing are considered. The former involves the scaling of dosage, and the latter involves both the dosage and schedule. The validity of the scaling relations is demonstrated by using measurements from previously reported clinical trials with adults and children (with ages generally 1 year or older) for the relatively new antifungal agent caspofungin and for the relatively new antibacterial agent linezolid. Standard pharmacodynamic effectiveness criteria are shown to be satisfied for the scaled dosage and schedule for children to the same extent that they are for the referenced adult. Consideration of scaling from adults to children is discussed for the case of new agents where no pediatric data are available and needed parameters are determined from in vitro measurements and preclinical animal data. A connection is also made between the allometric representation of clearance data and the dosing formulas. Limitations of the scaling results for infants because of growth and maturational matters are discussed. The general conclusion from this work is that the scaling theory does indeed have application to pediatric dosing for children, for both confirmation and refinement of present practice and guidance in pediatric treatment with new therapeutic agents.

  1. Clinical evaluation of clotrimazole. A broad-spectrum antifungal agent.

    PubMed

    Spiekermann, P H; Young, M D

    1976-03-01

    The efficacy and safety of the broad-spectrum, topically applied antifungal agent clotrimazole were evaluated in two double-blind, multicentric trials. Ten investigators reported on a total of 1,361 cases in which a 1% solution or a 1% cream formulation was compared with its respective vehicle. Clotrimazole was therapeutically effective, as confirmed by mycological cure (negative microscopy and culture) and clinical improvement, in tinea pedis, tinea cruris, tinea corporis, pityriasis versicolor, and cutaneous candidasis. Furthermore, species identification established the efficacy of clotrimazole against Trichophyton rubrum, T mentagrophytes, Epidermophyton floccosum, Microsporum canis, Malassezia furfur (Pityrosporum orbiculare), and Candida albicans. Safety was demonstrated by the low incidence of possibly drug-related adverse experiences, namely, 19 (2.7%) of 699 patients who were treated with clotrimazole, of whom four (0.6%) discontinued treatment.

  2. Synthesis and biological evaluation of fluconazole analogs with triazole-modified scaffold as potent antifungal agents.

    PubMed

    Hashemi, Seyedeh Mahdieh; Badali, Hamid; Irannejad, Hamid; Shokrzadeh, Mohammad; Emami, Saeed

    2015-04-01

    In order to find new azole antifungals, we have recently designed a series of triazole alcohols in which one of the 1,2,4-triazol-1-yl group in fluconazole structure has been replaced with 4-amino-5-aryl-3-mercapto-1,2,4-triazole motif. In this paper, we focused on the structural refinement of the primary lead, by removing the amino group from the structure to achieve 5-aryl-3-mercapto-1,2,4-triazole derivatives 10a-i and 11a-i. The in vitro antifungal susceptibility testing of title compounds demonstrated that most compounds had potent inhibitory activity against Candida species. Among them, 5-(2,4-dichlorophenyl)triazole analogs 10h and 11h with MIC values of <0.01 to 0.5μg/mL were 4-256 times more potent than fluconazole against Candida species.

  3. Direct effects of non-antifungal agents used in cancer chemotherapy and organ transplantation on the development and virulence of Candida and Aspergillus species

    PubMed Central

    Chen, Sharon C-A; Lewis, Russell E

    2011-01-01

    Conventional antineoplastic, novel immunosuppressive agents and antibiotics used in cancer treatment can directly affect the growth, development and virulence of Candida and Aspergillus species. Cytotoxic and cisplatin compounds have anti-Candida activity and may be synergistic with antifungal drugs; they also inhibit Candida and Aspergillus filamentation/conidation and effect increased virulence in vitro. Glucocorticoids enhance Candida adherence to epithelial cells, germination in serum and in vitro secretion of phospholipases and proteases, as well as growth of A. fumigatus. Calcineurin and target of rapamycin inhibitors perturb Candida and Aspergillus morphogenesis, stress responses and survival in serum, reduce azole tolerance in Candida, but yield conflicting in vivo data. Inhibition of candidal heat shock protein 90 and candidal-specific histone deacetylase represent feasible therapeutic approaches for candidiasis. Tyrosine kinase inhibitors inhibit fungal cell entry into epithelial cells and phagocytosis. Quinolone and other antibiotics may augment activity of azole and polyene agents. The correlation of in vitro effects with clinically meaningful in vivo systems is warranted. PMID:21701255

  4. Porosity of temporary denture soft liners containing antifungal agents

    PubMed Central

    Lima, Jozely Francisca Mello; Maciel, Janaína Gomes; Hotta, Juliana; Vizoto, Ana Carolina Pero; Honório, Heitor Marques; Urban, Vanessa Migliorini; Neppelenbroek, Karin Hermana

    2016-01-01

    ABSTRACT Incorporation of antifungals in temporary denture soft liners has been recommended for denture stomatitis treatment; however, it may affect their properties. Objective: To evaluate the porosity of a tissue conditioner (Softone) and a temporary resilient liner (Trusoft) modified by minimum inhibitory concentrations (MICs) of antifungal agents for Candida albicans biofilm. Material and Methods: The porosity was measured by water absorption, based on exclusion of the plasticizer effect. Initially, it was determined by sorption isotherms that the adequate storage solution for specimens (65×10×3.3 mm) of both materials was 50% anhydrous calcium chloride (S50). Then, the porosity factor (PF) was calculated for the study groups (n=10) formed by specimens without (control) or with drug incorporation at MICs (nystatin: Ny-0.032 g, chlorhexidine diacetate: Chx-0.064 g, or ketoconazole: Ke-0.128 g each per gram of soft liner powder) after storage in distilled water or S50 for 24 h, seven and 14 d. Data were statistically analyzed by 4-way repeated measures ANOVA and Tukey's test (α=.05). Results: Ke resulted in no significant changes in PF for both liners in water over 14 days (p>0.05). Compared with the controls, Softone and Trusoft PFs were increased at 14-day water immersion only after addition of Ny and Chx, and Chx, respectively (p<0.05). Both materials showed no significant changes in PF in up to 14 days of S50 immersion, compared with the controls (p>0.05). In all experimental conditions, Softone and Trusoft PFs were significantly lower when immersed in S50 compared with distilled water (p<0.05). Conclusions: The addition of antifungals at MICs resulted in no harmful effects for the porosity of both temporary soft liners in different periods of water immersion, except for Chx and Ny in Softone and Chx in Trusoft at 14 days. No deleterious effect was observed for the porosity of both soft liners modified by the drugs at MICs over 14 days of S50 immersion

  5. Safety and tolerability of oral antifungal agents in the treatment of fungal nail disease: a proven reality

    PubMed Central

    Elewski, Boni; Tavakkol, Amir

    2005-01-01

    Clinicians now have five oral antifungal therapeutic agents to choose from when assessing the risk–benefits associated with a particular treatment for onychomycosis (OM): griseofulvin, itraconazole, terbinafine, ketoconazole, and fluconazole. Only the first three are approved by the FDA for this indication. Griseofulvin is fungistatic and inhibits nucleic acid synthesis, arresting cell division at metaphase, and impairing fungal wall synthesis. Due to its low cure rates and high relapse, it is rarely used for treatment of onychomycosis. Itraconazole is a broad spectrum drug and is effective against dermatophytes, candida, and some nondermatophytic molds. Itraconazole works by inhibiting ergosterol synthesis via cytochrome P-450 (CYP450)-dependent demethylation step. This azole antifungal agent is metabolized in the liver by cytochrome P-450 3A4 (CYP3A4), and therefore has the potential to interact with drugs metabolized through this pathway. Terbinafine, an allylamine, is fungicidal and remains at therapeutic levels in keratinized tissues, but with a short plasma half-life of 36 hours. Terbinafine has the advantage in that it does not inhibit CYP3A4 isoenzyme during its metabolism where some 50% of all commonly prescribed drugs are metabolized. The only potentially significant drug interaction with terbinafine is with the cytochrome P-450 2D6 (CYP2D6) isoenzyme. The lack of widely reported or published clinically relevant drug interactions, and extensive experience from a large prospective, surveillance study conducted in “real world” setting with no patient exclusions, suggest that this is not a major issue. The high cure rates of terbinafine against dermatophytes, as shown in many studies since its launch in the 1990s, together with lack of clinically significant drug interactions and well established safety record, indicate the use of continuous oral terbinafine as the top choice for the treatment of onychomycosis in most patients. PMID:18360572

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

    USDA-ARS?s Scientific Manuscript database

    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...

  7. Porosity of temporary denture soft liners containing antifungal agents.

    PubMed

    Lima, Jozely Francisca Mello; Maciel, Janaína Gomes; Hotta, Juliana; Vizoto, Ana Carolina Pero; Honório, Heitor Marques; Urban, Vanessa Migliorini; Neppelenbroek, Karin Hermana

    2016-01-01

    To evaluate the porosity of a tissue conditioner (Softone) and a temporary resilient liner (Trusoft) modified by minimum inhibitory concentrations (MICs) of antifungal agents for Candida albicans biofilm. The porosity was measured by water absorption, based on exclusion of the plasticizer effect. Initially, it was determined by sorption isotherms that the adequate storage solution for specimens (65×10×3.3 mm) of both materials was 50% anhydrous calcium chloride (S50). Then, the porosity factor (PF) was calculated for the study groups (n=10) formed by specimens without (control) or with drug incorporation at MICs (nystatin: Ny-0.032 g, chlorhexidine diacetate: Chx-0.064 g, or ketoconazole: Ke-0.128 g each per gram of soft liner powder) after storage in distilled water or S50 for 24 h, seven and 14 d. Data were statistically analyzed by 4-way repeated measures ANOVA and Tukey's test (α=.05). Ke resulted in no significant changes in PF for both liners in water over 14 days (p>0.05). Compared with the controls, Softone and Trusoft PFs were increased at 14-day water immersion only after addition of Ny and Chx, and Chx, respectively (p<0.05). Both materials showed no significant changes in PF in up to 14 days of S50 immersion, compared with the controls (p>0.05). In all experimental conditions, Softone and Trusoft PFs were significantly lower when immersed in S50 compared with distilled water (p<0.05). The addition of antifungals at MICs resulted in no harmful effects for the porosity of both temporary soft liners in different periods of water immersion, except for Chx and Ny in Softone and Chx in Trusoft at 14 days. No deleterious effect was observed for the porosity of both soft liners modified by the drugs at MICs over 14 days of S50 immersion.

  8. 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. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

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

    PubMed Central

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

    2015-01-01

    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

  10. Antifungal activities of SCY-078 (MK-3118) and standard antifungal agents against clinical non-Aspergillus mold isolates.

    PubMed

    Lamoth, Frédéric; Alexander, Barbara D

    2015-07-01

    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.

  11. Distribution of the antifungal agents sordarins across filamentous fungi.

    PubMed

    Vicente, Francisca; Basilio, Angela; Platas, Gonzalo; Collado, Javier; Bills, Gerald F; González del Val, Antonio; Martín, Jesús; Tormo, José R; Harris, Guy H; Zink, Deborah L; Justice, Michael; Kahn, Jennifer Nielsen; Peláez, Fernando

    2009-01-01

    Sordarins are a class of natural antifungal agents which act by specifically inhibiting fungal protein synthesis through their interaction with the elongation factor 2, EF2. A number of natural sordarins produced by diverse fungi of different classes have been reported in the literature. We have run an exhaustive search of sordarin-producing fungi using two different approaches consecutively, the first one being a differential sensitivity screen using a sordarin-resistant mutant yeast strain run in parallel with a wild type strain, and the second one an empiric screen against Candida albicans followed by early detection of sordarins by LC-MS analysis. Using these two strategies we have detected as many as 22 new strains producing a number of different sordarin analogues, either known (sordarin, xylarin, zofimarin) or novel (isozofimarin and 4'-O-demethyl sordarin). Sordarin and xylarin were the most frequently found compounds in the class. The producing strains were subjected to sequencing of the ITS region to determine their phylogenetic affinities. All the strains were shown to belong to the Xylariales, being distributed across three families in this order, the Xylariaceae, the Amphisphaeriaceae, and the Diatrypaceae. Despite being screened in large numbers, we did not find sordarin production in any other fungal group, including those orders where sordarin producing fungi are known to exist (i.e., Sordariales, Eurotiales, and Microascales), suggesting that the production of sordarin is a trait more frequently associated to members of the Xylariales than to any other fungal order.

  12. Antifungal Resistance, Metabolic Routes as Drug Targets, and New Antifungal Agents: An Overview about Endemic Dimorphic Fungi

    PubMed Central

    Parente-Rocha, Juliana Alves; Bailão, Alexandre Melo; Amaral, André Correa; Paccez, Juliano Domiraci; Borges, Clayton Luiz

    2017-01-01

    Diseases caused by fungi can occur in healthy people, but immunocompromised patients are the major risk group for invasive fungal infections. Cases of fungal resistance and the difficulty of treatment make fungal infections a public health problem. This review explores mechanisms used by fungi to promote fungal resistance, such as the mutation or overexpression of drug targets, efflux and degradation systems, and pleiotropic drug responses. Alternative novel drug targets have been investigated; these include metabolic routes used by fungi during infection, such as trehalose and amino acid metabolism and mitochondrial proteins. An overview of new antifungal agents, including nanostructured antifungals, as well as of repositioning approaches is discussed. Studies focusing on the development of vaccines against antifungal diseases have increased in recent years, as these strategies can be applied in combination with antifungal therapy to prevent posttreatment sequelae. Studies focused on the development of a pan-fungal vaccine and antifungal drugs can improve the treatment of immunocompromised patients and reduce treatment costs. PMID:28694566

  13. 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

  14. Optimization of Azoles as Anti-Human Immunodeficiency Virus Agents Guided by Free-Energy Calculations

    PubMed Central

    Zeevaart, Jacob G.; Wang, Ligong; Thakur, Vinay V.; Leung, Cheryl S.; Tirado-Rives, Julian; Bailey, Christopher M.; Domaoal, Robert A.; Anderson, Karen S.; Jorgensen, William L.

    2009-01-01

    Efficient optimization of an inactive 2-anilinyl-5-benzyloxadiazole core has been guided by free energy perturbation (FEP) calculations to provide potent non-nucleoside inhibitors of human immunodeficiency virus (HIV) reverse transcriptase (NNRTIs). An FEP “chlorine scan” was performed to identify the most promising sites for substitution of aryl hydrogens. This yielded NNRTIs 8 and 10 with activities (EC50) of 820 and 310 nM for protection of human T-cells from infection by wild-type HIV-1. FEP calculations for additional substituent modifications and change of the core heterocycle readily led to oxazoles 28 and 29, which were confirmed as highly potent anti-HIV agents with activities in the 10–20 nM range. The designed compounds were also monitored for possession of desirable pharmacological properties by use of additional computational tools. Overall, the trends predicted by the FEP calculations were well borne out by the assay results. FEP-guided lead optimization is confirmed as a valuable tool for molecular design including drug discovery; chlorine scans are particularly attractive since they are both straightforward to perform and highly informative. PMID:18588301

  15. 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.

  16. 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

  17. Isolation of azole-resistant Aspergillus fumigatus from the environment in the south-eastern USA.

    PubMed

    Hurst, Steven F; Berkow, Elizabeth L; Stevenson, Katherine L; Litvintseva, Anastasia P; Lockhart, Shawn R

    2017-09-01

    Azole resistance in isolates of the fungus Aspergillus fumigatus has been associated with agricultural use of azole fungicides. Environmental isolation of resistant isolates has been reported in Asia, Africa, Europe and South America. To determine whether A. fumigatus isolates containing TR34/L98H or TR46/Y121F/T289A can be found in fields in the USA treated with agricultural azoles. Crop debris was collected and screened for A. fumigatus. All A. fumigatus isolates were screened for azole resistance. The CYP51A gene of azole-resistant isolates was sequenced. The population structure of a subset of isolates was determined using microsatellite typing. This article identifies azole-resistant A. fumigatus isolates containing the TR34/L98H mutation in an experimental peanut field that had been treated with azole fungicides. These findings suggest the development of resistance to azole antifungals in A. fumigatus may be present where agricultural azoles are used in the USA.

  18. Drug utilization study of systemic antifungal agents in a Brazilian tertiary care hospital.

    PubMed

    de Souza, Maria Clara Padovani; Dos Santos, Andrezza Gouvêa; Reis, Adriano Max Moreira

    2016-12-01

    Background The inappropriate use of systemic antifungal agents can result in unnecessary exposure, adverse events, increased microbial resistance and increased costs. Aim This study analysed the use of systemic antifungal agents and adherence to treatment guidelines for fungal infections. Setting A Brazilian tertiary hospital. Methods This cross-sectional study investigated 183 patients who were treated with systemic antifungals. Antifungal drugs were classified according to the fourth level of the Anatomical Therapeutic Chemical classification system. The appropriateness of treatments was analysed with respect to the indication, dose and potential drug-drug interactions. Descriptive and univariate statistical analyses were performed. The main outcome measure was the frequency of adherence to treatment guidelines for fungal infections. Results The number of established treatments was 320, with 163 (50.9 %) pre-emptive, 63 (19.7 %) targeted, 56 (17.5 %) empirical and 38 (11.9 %) prophylactic treatments. The overall adherence to the treatment guidelines was 29.4 %. The proportion of appropriate treatment considering indication, dosage and drug-drug interactions was 84.1, 67.8 and 47.2 %, respectively. The most commonly prescribed systemic antifungal agents were fluconazole in 170 (53.1 %), voriconazole in 43 (13.4 %) and amphotericin B deoxycholate in 36 (11.3 %) cases. Conclusion The study showed a low proportion of appropriate antifungal drug use; the dosage and drug-drug interactions criteria were the determining factors for the high percentage of non-adherence to treatment guidelines in the hospital. The profile of antifungal agents used showed the predominance of fluconazole as well as the use of new antifungal drugs.

  19. Antifungal agents from Pseudallescheria boydii SNB-CN73 isolated from a Nasutitermes sp. termite.

    PubMed

    Nirma, Charlotte; Eparvier, Véronique; Stien, Didier

    2013-05-24

    Defense mutualisms between social insects and microorganisms have been described in the literature. The present article describes the discovery of a Pseudallescheria boydii strain isolated from Nasutitermes sp. The microbial symbiont produces two antifungal metabolites: tyroscherin and N-methyltyroscherin, a compound not previously described in the literature. Methylation of tyroscherin has confirmed the structure of N-methyltyroscherin. Both compounds are effective antifungal agents with favorable selectivity indices for Candida albicans and Trichophyton rubrum.

  20. Comparison of EUCAST and CLSI broth microdilution methods for the susceptibility testing of 10 systemically active antifungal agents when tested against Candida spp.

    PubMed

    Pfaller, Michael A; Castanheira, Mariana; Messer, Shawn A; Rhomberg, Paul R; Jones, Ronald N

    2014-06-01

    The antifungal broth microdilution (BMD) method of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) was compared with Clinical and Laboratory Standards Institute (CLSI) BMD method M27-A3 for amphotericin B, flucytosine, anidulafungin, caspofungin, micafungin, fluconazole, isavuconazole, itraconazole, posaconazole, and voriconazole susceptibility testing of 357 isolates of Candida. The isolates were selected from global surveillance collections to represent both wild-type (WT) and non-WT MIC results for the azoles (12% of fluconazole and voriconazole results were non-WT) and the echinocandins (6% of anidulafungin and micafungin results were non-WT). The study collection included 114 isolates of Candida albicans, 73 of C. glabrata, 76 of C. parapsilosis, 60 of C. tropicalis, and 34 of C. krusei. The overall essential agreement (EA) between EUCAST and CLSI results ranged from 78.9% (posaconazole) to 99.6% (flucytosine). The categorical agreement (CA) between methods and species of Candida was assessed using previously determined CLSI epidemiological cutoff values. The overall CA between methods was 95.0% with 2.5% very major (VM) and major (M) discrepancies. The CA was >93% for all antifungal agents with the exception of caspofungin (84.6%), where 10% of the results were categorized as non-WT by the EUCAST method and WT by the CLSI method. Problem areas with low EA or CA include testing of amphotericin B, anidulafungin, and isavuconazole against C. glabrata, itraconazole, and posaconazole against most species, and caspofungin against C. parapsilosis, C. tropicalis, and C. krusei. We confirm high level EA and CA (>90%) between the 2 methods for testing fluconazole, voriconazole, and micafungin against all 5 species. The results indicate that the EUCAST and CLSI methods produce comparable results for testing the systemically active antifungal agents against the 5 most common species of Candida; however, there are several areas where additional

  1. Analysis Of Volatile Fingerprints: A Rapid Screening Method For Antifungal Agents For Efficacy Against Dermatophytes

    NASA Astrophysics Data System (ADS)

    Naraghi, Kamran; Sahgal, Natasha; Adriaans, Beverley; Barr, Hugh; Magan, Naresh

    2009-05-01

    The potential of using an electronic nose (E. nose) for rapid screening dermatophytes to antifungal agents was studied. In vitro, the 50 and 90% effective concentration (EC) values of five antifungal agents for T. rubrum and T. mentagrophytes were obtained by mycelial growth assays. Then, the qualitative volatile production patterns of the growth responses of these fungi to these values were incorporated into solid medium were analysed after 96-120 hrs incubation at 25° C using headspace analyses. Overall, results, using PCA and CA demonstrated that it is possible to differentiate between various treatments within 96-120 hrs. This study showed that potential exists for using qualitative volatile patterns as a rapid screening method for antifungal agents for microorganism. This approach could also facilitate the monitoring of antimicrobial drug activities and infection control programmes and perhaps drug resistance build up in microbial species.

  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.

  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. Benzofurazan derivatives as antifungal agents against phytopathogenic fungi.

    PubMed

    Wang, Lili; Zhang, Ying-Ying; Wang, Lei; Liu, Feng-you; Cao, Ling-Ling; Yang, Jing; Qiao, Chunhua; Ye, Yonghao

    2014-06-10

    A series of benzofurazan derivatives were prepared and evaluated for their biological activities against four important phytopathogenic fungi, namely, Rhizoctonia solani, Sclerotinia sclerotiorum, Fusarium graminearum and Phytophthora capsici, using the mycelium growth inhibition method. The structures of these compounds were characterized by (1)H NMR, (13)C NMR, and HRMS. N-(3-chloro-4-fluorophenyl)-7-nitrobenzo[c][1,2,5]oxadiazol-4-amine (A3) displayed the maximum antifungal activity against R. solani (IC50 = 1.91 μg/mL), which is close to that of the positive control Carbendazim (IC50 = 1.42 μg/mL). For other benzofurazan derivatives with nitro group at R(4) position (A series), 9 out of 30 compounds exhibited high antifungal effect against strain R. solani, with IC50 values less than 5 μg/mL. Most of the derivatives with substituents at R(2) and R(3) positions (B series) displayed moderate growth inhibition against S. sclerotiorum (IC50 < 25 μg/mL). Also, several benzofuran derivatives with nitro group at R(4) position and another conjugated aromatic ring at the R(1) position of the phenyl ring displayed high antifungal capability against strain R. solani. Compounds with substituents at R(2) and R(3) position had moderate efficacy against strain S. sclerotiorum.

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

    PubMed

    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.

  6. 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

  7. The Synthesis and Study of New Ribavirin Derivatives and Related Nucleoside Azole Carboxamides as Agents Active against RNA Viruses.

    DTIC Science & Technology

    1981-09-01

    UNCLASSIFIED DAMDt779-C 9046 FG65 N EhEmhEEEEmhhEI mhEEomhhEEEmhEI mmEEmmhhhEE smmhhmhohEEmhh Eu....momo L3 2 L .: 1111.25 I i4A . MICROCOPY RESOLUTION TEST...during the course of this synthetic study. Most of the compounds synthesized were tested at the U.S. Army Medical Research Institute of Infectious Diseases...nucleosides with the antiviral potency of pyrazofurin but with much less toxicity may be prepared. The problem of design- ing and synthesizing an azole

  8. [Advances in the diagnosis and treatment of yeast infections: role of the new antifungal agents].

    PubMed

    Pemán, Javier; Almirante, Benito

    2008-11-01

    Invasive candidiasis has become a public health problem due to the high associated rates of morbidity and mortality. As in other systemic infections, accurate and early diagnosis is essential. Despite its limited sensitivity (50%), blood culture continues to be the most effective technique for the diagnosis of candidemia. New culture-independent techniques have been marketed with the aim of improving diagnostic yield. Among these techniques, the most notable are (1-3)-beta-D-glucan and anti-germ-tube antibody detection. However, the best option to optimize the diagnosis of invasive candidiasis seems to be the combination of two techniques that detect antigen, antibodies, (1-3)-beta-D-glucan or DNA. Fluconazole, and sometimes amphotericin B, remain the antifungal agents of choice for the treatment of candidiasis. In the last few years, new antifungal agents have been introduced with the aim of improving the prognosis of some clinical presentations of this disease. The echinocandins and second-generation triazoles show greater antifungal activity than fluconazole. Moreover, clinical trials of candidiasis in different localizations have shown that these drugs have excellent efficacy and safety profiles. The potential for drug interactions with some of these antifungal agents is considerable. The contribution of the new antifungal drugs in the treatment of candidiasis should be defined in the near future.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  10. QSAR of heterocyclic antifungal agents by flip regression

    NASA Astrophysics Data System (ADS)

    Deeb, Omar; Clare, Brian W.

    2008-12-01

    QSAR analysis of a set of 96 heterocyclics with antifungal activity was performed. The results reveals that a pyridine ring is more favorable than benzene as the 6-membered ring, for high activity, but thiazole is unfavorable as the 5-membered ring relative to imidazole or oxazole. Methylene is the spacer leading to the highest activity. The descriptors used are indicator variables, which account for identity of substituent, lipophilicity and volume of substituent, and total polarizability. Unlike previously reported results for this data set, our fits do not exceed the limitations set by the nature of the data itself.

  11. Interaction of Candida albicans Biofilms with Antifungals: Transcriptional Response and Binding of Antifungals to Beta-Glucans ▿ †

    PubMed Central

    Vediyappan, Govindsamy; Rossignol, Tristan; d'Enfert, Christophe

    2010-01-01

    Candida albicans can form biofilms that exhibit elevated intrinsic resistance to various antifungal agents, in particular azoles and polyenes. The molecular mechanisms involved in the antifungal resistance of biofilms remain poorly understood. We have used transcript profiling to explore the early transcriptional responses of mature C. albicans biofilms exposed to various antifungal agents. Mature C. albicans biofilms grown under continuous flow were exposed for as long as 2 h to concentrations of fluconazole (FLU), amphotericin B (AMB), and caspofungin (CAS) that, while lethal for planktonic cells, were not lethal for biofilms. Interestingly, FLU-exposed biofilms showed no significant changes in gene expression over the course of the experiment. In AMB-exposed biofilms, 2.7% of the genes showed altered expression, while in CAS-exposed biofilms, 13.0% of the genes had their expression modified. In particular, exposure to CAS resulted in the upregulation of hypha-specific genes known to play a role in biofilm formation, such as ALS3 and HWP1. There was little overlap between AMB- or CAS-responsive genes in biofilms and those that have been identified as AMB, FLU, or CAS responsive in C. albicans planktonic cultures. These results suggested that the resistance of C. albicans biofilms to azoles or polyenes was due not to the activation of specific mechanisms in response to exposure to these antifungals but rather to the intrinsic properties of the mature biofilms. In this regard, our study led us to observe that AMB physically bound C. albicans biofilms and beta-glucans, which have been proposed to be major constituents of the biofilm extracellular matrix and to prevent azoles from reaching biofilm cells. Thus, enhanced extracellular matrix or beta-glucan synthesis during biofilm growth might prevent antifungals, such as azoles and polyenes, from reaching biofilm cells, thus limiting their toxicity to these cells and the associated transcriptional responses. PMID

  12. Establishment of a Novel Model of Onychomycosis in Rabbits for Evaluation of Antifungal Agents

    PubMed Central

    Shimamura, Tsuyoshi; Kubota, Nobuo; Nagasaka, Saori; Suzuki, Taku; Mukai, Hideki; Shibuya, Kazutoshi

    2011-01-01

    We developed a novel model of onychomycosis in which we observed fungi in the deep layer of the nail, and we used the model to evaluate the efficacy of two topical antifungal drugs. To establish an experimental, in vivo model of onychomycosis, we applied Trichophyton mentagrophytes TIMM2789 to the nails of the hind limbs of rabbits that underwent steroid treatment. The nails were taken from the rabbits' feet at 0, 2, and 6 weeks after a 2-week infection. The localization of the fungi was evaluated histopathologically. Some fungi were seen to penetrate to the nail bed, and the infection rate in the sample at 0, 2, and 6 weeks after infection was 57, 87, and 93%, respectively. In addition, fungi proliferated and moved proximally into the nail plate in a manner that depended on the duration of infection. Second, using this model we evaluated antifungal efficacy both by the culture recovery method and histopathological examination. Two topical antifungal drugs, 8% ciclopirox nail lacquer and 5% amorolfine nail lacquer, were applied to the nail for 4 weeks in each group. On histopathological examination, two antifungal treatment groups showed no significant difference against the nontreated control group. However, there were a significantly low fungus-positive rate and intensity of the recovery of fungi on culture between antifungal treatment and nontreated control groups. We therefore suggest that we have established an in vivo model of onychomycosis that is useful for the evaluation of the efficacy of antifungal agents. PMID:21555762

  13. 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

  14. Pharmacogenomics of triazole antifungal agents: implications for safety, tolerability and efficacy.

    PubMed

    Amsden, Jarrett R; Gubbins, Paul O

    2017-10-12

    Introduction Triazole antifungal agents are prescribed to treat invasive fungal infections in neutropenic and non-neutropenic patients. These antifungal agents are substrates and inhibitors of cytochrome P450 (CYP). Genetic polymorphisms in CYP2C9, CYP2C19 and CYP3A5 can lead to large population-specific variations in drug efficacy and safety, optimal dosing, or contribute to drug interactions associated with this class. Areas covered This manuscript reviews the pharmacogenomics (i.e. the influence of genetics on drug disposition) of triazole antifungal agents related to their CYP-mediated metabolism and summarizes their implications on triazole efficacy, safety, and tolerability. A search of English language original research, and scholarly reviews describing the pharmacogenomics of triazole antifungal agents and their impact on drug efficacy, safety, and tolerability published from 1980 to present was undertaken using PubMed. Expert Opinion Currently studies demonstrating the pharmacogenomic influences on itraconazole, posaconazole and isavuconazole are minimal and limited to their inhibitory effects on CYP3A4 in expressors of CYP3A5 variants. Conversely, there are significant pharmacogenomic considerations for voriconazole because it interacts with several polymorphic CYPs, most notably CYP2C19. Pharmacogenomics of CYP2C9 do not appear to effect fluconazole safety and efficacy. However, genetic polymorphisms may influence its drug interactions but this needs further study.

  15. 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

  16. Notable Increasing Trend in Azole Non-susceptible Candida tropicalis Causing Invasive Candidiasis in China (August 2009 to July 2014): Molecular Epidemiology and Clinical Azole Consumption

    PubMed Central

    Fan, Xin; Xiao, Meng; Liao, Kang; Kudinha, Timothy; Wang, He; Zhang, Li; Hou, Xin; Kong, Fanrong; Xu, Ying-Chun

    2017-01-01

    Objectives: To report the notable increasing trends of C. tropicalis antifungal resistance in the past 5 years, and explore molecular epidemiology, and the relationship between clinical azoles consumption and increased resistance rate. Methods: Between August 2009 and July 2014, 507 non-duplicated C. tropicalis isolates causing invasive candidiasis were collected from 10 hospitals in China. The in vitro antifungal susceptibility of nine common agents was determined by Sensititre YeastOne™ using current available species-specific clinical breakpoint (CBPs) or epidemiological cut-off values (ECVs). A high discriminatory three-locus (ctm1, ctm3, and ctm24) microsatellite scheme was used for typing of all isolates collected. Clinical consumption of fluconazole and voriconazole was obtained and the Defined Daily Dose measurement units were assigned to the data. Results: Overall, 23.1 and 20.7% of isolates were non-susceptible to fluconazole and voriconazole, respectively. And over 5 years, the non-susceptible rate of C. tropicalis isolates to fluconazole and voriconazole continuously increased from 11.2 to 42.7% for fluconazole (P < 0.001), and from 10.4 to 39.1% for voriconazole (P < 0.001). Four genotype clusters were observed to be associated with fluconazole non-susceptible phenotype. However, the increase in azole non-susceptible rate didn't correlate with clinical azole consumption. Conclusions: The rapid emergence of azole resistant C. tropicalis strains in China is worrying, and continuous surveillance is warranted and if the trend persists, empirical therapeutic strategies for C. tropicalis invasive infections should be modified. PMID:28382028

  17. 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

  18. Imaging microscopic distribution of antifungal agents in dandruff treatments with stimulated Raman scattering microscopy

    NASA Astrophysics Data System (ADS)

    Garrett, Natalie L.; Singh, Bhumika; Jones, Andrew; Moger, Julian

    2017-06-01

    Treatment of dandruff condition usually involves use of antidandruff shampoos containing antifungal agents. Different antifungal agents show variable clinical efficacy based on their cutaneous distribution and bioavailability. Using stimulated Raman scattering (SRS), we mapped the distribution of unlabeled low-molecular weight antifungal compounds zinc pyrithione (ZnPT) and climbazole (CBZ) on the surface of intact porcine skin with cellular precision. SRS has sufficient chemical selectivity and sensitivity to detect the agents on the skin surface based on their unique chemical motifs that do not occur naturally in biological tissues. Moreover, SRS is able to correlate the distribution of the agents with the morphological features of the skin using the CH2 stretch mode, which is abundant in skin lipids. This is a significant strength of the technique since it allows the microscopic accumulation of the agents to be correlated with physiological features and their chemical environment without the use of counter stains. Our findings show that due to its lower solubility, ZnPT coats the surface of the skin with a sparse layer of crystals in the size range of 1 to 4 μm. This is consistent with the current understanding of the mode of action of ZnPT. In contrast, CBZ being more soluble and hydrophobic resulted in diffuse homogeneous distribution. It predominantly resided in microscopic lipid-rich crevasses and penetrated up to 60 μm into the infundibular spaces surrounding the hair shaft. The ability of the SRS to selectively map the distribution of agents on the skin's surface has the potential to provide insight into the mechanisms underpinning the topical application of antifungal or skin-active agents that could lead to the rational engineering of enhanced formulations.

  19. Imaging microscopic distribution of antifungal agents in dandruff treatments with stimulated Raman scattering microscopy.

    PubMed

    Garrett, Natlaie L; Singh, Bhumika; Jones, Andrew; Moger, Julian

    2017-06-01

    Treatment of dandruff condition usually involves use of antidandruff shampoos containing antifungal agents. Different antifungal agents show variable clinical efficacy based on their cutaneous distribution and bioavailability. Using stimulated Raman scattering (SRS), we mapped the distribution of unlabeled low-molecular weight antifungal compounds zinc pyrithione (ZnPT) and climbazole (CBZ) on the surface of intact porcine skin with cellular precision. SRS has sufficient chemical selectivity and sensitivity to detect the agents on the skin surface based on their unique chemical motifs that do not occur naturally in biological tissues. Moreover, SRS is able to correlate the distribution of the agents with the morphological features of the skin using the CH 2 stretch mode, which is abundant in skin lipids. This is a significant strength of the technique since it allows the microscopic accumulation of the agents to be correlated with physiological features and their chemical environment without the use of counter stains. Our findings show that due to its lower solubility, ZnPT coats the surface of the skin with a sparse layer of crystals in the size range of 1 to 4 ?? ? m . This is consistent with the current understanding of the mode of action of ZnPT. In contrast, CBZ being more soluble and hydrophobic resulted in diffuse homogeneous distribution. It predominantly resided in microscopic lipid-rich crevasses and penetrated up to 60 ?? ? m into the infundibular spaces surrounding the hair shaft. The ability of the SRS to selectively map the distribution of agents on the skin’s surface has the potential to provide insight into the mechanisms underpinning the topical application of antifungal or skin-active agents that could lead to the rational engineering of enhanced formulations.

  20. Triterpenoid glycosides from Medicago sativa as antifungal agents against Pyricularia oryzae.

    PubMed

    Abbruscato, Pamela; Tosi, Solveig; Crispino, Laura; Biazzi, Elisa; Menin, Barbara; Picco, Anna M; Pecetti, Luciano; Avato, Pinarosa; Tava, Aldo

    2014-11-19

    The antifungal properties of saponin mixtures from alfalfa (Medicago sativa L.) tops and roots, the corresponding mixtures of prosapogenins from tops, and purified saponins and sapogenins against the causal agent of rice blast Pyricularia oryzae isolates are presented. In vitro experiments highlighted a range of activities, depending upon the assayed metabolite. The antifungal effects of the most promising prosapogenin mixture from alfalfa tops were confirmed by means of in planta tests using three different Italian cultivars of rice (Oryza sativa L. ssp. japonica), known to possess high, medium, and low blast resistance. The evidenced antifungal properties of the tested metabolites allowed some considerations on their structure-activity relationship. Results indicate that prosapogenins are active compounds to prevent the fungal attack of P. oryzae on different rice cultivars. Therefore, if properly formulated, these substances could represent a promising and environmentally friendly treatment to control rice blast.

  1. In vitro activities of new triazole antifungal agents, posaconazole and voriconazole, against oral Candida isolates from patients suffering from denture stomatitis.

    PubMed

    Marcos-Arias, Cristina; Eraso, Elena; Madariaga, Lucila; Carrillo-Muñoz, Alfonso Javier; Quindós, Guillermo

    2012-01-01

    Denture stomatitis is often treated with antifungal agents but recurrences or new episodes are common, and certain episodes can be resistant. New triazoles, such as posaconazole and voriconazole, may represent useful alternatives for management. In vitro activities of amphotericin B, nystatin, miconazole, fluconazole, itraconazole, posaconazole and voriconazole against 150 oral Candida (101 C. albicans, 18 C. tropicalis, 12 C. glabrata, 11 C. guilliermondii, 4 C. parapsilosis, 2 Saccharomyces cerevisiae, 1 C. dubliniensis and 1 C. krusei) from 100 denture wearers were tested by the CLSI M27-A3 method. Resistant isolates were retested by Sensititre YeastOne and Etest. Most antifungal agents were very active. However, 4 C. glabrata (33.3%), 2 C. tropicalis (11.1%), 6 C. albicans (5.6%) and 1 C. krusei were resistant to itraconazole. Posaconazole was active against 143 yeast isolates (95.3%): 6 C. albicans (5.9%) and 1 C. tropicalis (5.6%) were resistant. Geometric mean MICs were 0.036 μg/ml for C. parapsilosis, 0.062 μg/ml for C. albicans, 0.085 μg/ml for C. tropicalis, 0.387 μg/ml for C. guilliermondii and 0.498 μg/ml for C. glabrata. Voriconazole was active against 148 isolates (98.7%) with geometric mean MICs ranging from 0.030 μg/ml for C. parapsilosis, 0.042 μg/ml for C. albicans, 0.048 μg/ml for C. tropicalis, 0.082 μg/ml for C. guilliermondii, to 0.137 μg/ml for C. glabrata. Only 2 C. albicans (2%) were resistant to voriconazole showing cross-resistance to other azoles. Posaconazole and voriconazole have excellent in vitro activities against all Candida isolates and could represent useful alternatives for recalcitrant or recurrent candidiasis.

  2. 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

  3. Minimal inhibitory concentration distributions and epidemiological cutoff values of five antifungal agents against Sporothrix brasiliensis.

    PubMed

    Almeida-Paes, Rodrigo; Brito-Santos, Fábio; Figueiredo-Carvalho, Maria Helena Galdino; Machado, Ana Caroline Sá; Oliveira, Manoel Marques Evangelista; Pereira, Sandro Antonio; Gutierrez-Galhardo, Maria Clara; Zancopé-Oliveira, Rosely Maria

    2017-05-01

    Sporothrix brasiliensis is the most virulent sporotrichosis agent. This species usually responds to antifungal drugs, but therapeutic failure can occur in some patients. Antifungal susceptibility tests have been performed on this species, but no clinical breakpoints (CBPs) are available. In this situation, minimal inhibitory concentration (MIC) distributions and epidemiological cutoff values (ECVs) support the detection of identification of resistant strains. To study the MIC distributions of five antifungal drugs against S. brasiliensis and to propose tentative ECVs. MICs of amphotericin B (AMB), itraconazole (ITR), ketoconazole (KET), posaconazole (POS), and terbinafine (TRB) against 335 S. brasiliensis strains were determined by the Clinical and Laboratory Standards Institute broth microdilution method. The proposed ECV, in µg/mL, for AMB, ITR, KET, POS, and TRB were 4.0, 2.0, 1.0, 2.0, and 0.25, respectively. Percentages of wild-type strains in our population for the above antifungal drugs were 98.48, 95.22, 95.33, 100, and 97.67%, respectively. These ECVs will be useful to detect strains with resistance, to define CBPs, and to elaborate specific therapeutic guidelines for S. brasiliensis. Rational use of antifungals is strongly recommended to avoid the emergence of resistant strains and ensure the therapeutic effectiveness of sporotrichosis.

  4. Minimal inhibitory concentration distributions and epidemiological cutoff values of five antifungal agents against Sporothrix brasiliensis

    PubMed Central

    Almeida-Paes, Rodrigo; Brito-Santos, Fábio; Figueiredo-Carvalho, Maria Helena Galdino; Machado, Ana Caroline Sá; Oliveira, Manoel Marques Evangelista; Pereira, Sandro Antonio; Gutierrez-Galhardo, Maria Clara; Zancopé-Oliveira, Rosely Maria

    2017-01-01

    BACKGROUND Sporothrix brasiliensis is the most virulent sporotrichosis agent. This species usually responds to antifungal drugs, but therapeutic failure can occur in some patients. Antifungal susceptibility tests have been performed on this species, but no clinical breakpoints (CBPs) are available. In this situation, minimal inhibitory concentration (MIC) distributions and epidemiological cutoff values (ECVs) support the detection of identification of resistant strains. OBJECTIVES To study the MIC distributions of five antifungal drugs against S. brasiliensis and to propose tentative ECVs. METHODS MICs of amphotericin B (AMB), itraconazole (ITR), ketoconazole (KET), posaconazole (POS), and terbinafine (TRB) against 335 S. brasiliensis strains were determined by the Clinical and Laboratory Standards Institute broth microdilution method. FINDINGS The proposed ECV, in µg/mL, for AMB, ITR, KET, POS, and TRB were 4.0, 2.0, 1.0, 2.0, and 0.25, respectively. Percentages of wild-type strains in our population for the above antifungal drugs were 98.48, 95.22, 95.33, 100, and 97.67%, respectively. MAIN CONCLUSIONS These ECVs will be useful to detect strains with resistance, to define CBPs, and to elaborate specific therapeutic guidelines for S. brasiliensis. Rational use of antifungals is strongly recommended to avoid the emergence of resistant strains and ensure the therapeutic effectiveness of sporotrichosis. PMID:28443986

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

    PubMed Central

    Jensen, Rasmus Hare; Cuenca-Estrella, Manuel

    2015-01-01

    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

  6. 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.

  7. In vitro antifungal activity of dihydroxyacetone against causative agents of dermatomycosis.

    PubMed

    Stopiglia, Cheila Denise Ottonelli; Vieira, Fabiane Jamono; Mondadori, Andressa Grazziotin; Oppe, Tércio Paschke; Scroferneker, Maria Lúcia

    2011-04-01

    Dihydroxyacetone (DHA), a three-carbon sugar, is the browning ingredient in commercial sunless tanning formulations. DHA preparations have been used for more than 50 years and are currently highly popular for producing temporary pigmentation resembling an ultraviolet-induced tan. In this work, the in vitro antifungal activity of dihydroxyacetone was tested against causative agents of dermatomycosis, more specifically against dermatophytes and Candida spp. The antifungal activity was determined by the broth microdilution method according to the Clinical and Laboratory Standards Institute guidelines for yeasts and filamentous fungi. The data obtained show that the fungicidal activity varied from 1.6 to 50 mg ml(-1). DHA seems to be a promising substance for the treatment of dermatomycosis because it has antifungal properties at the same concentration used in artificial suntan lotions. Therefore, it is a potential low-toxicity antifungal agent that may be used topically because of its penetration into the corneal layers of the skin.

  8. 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.

  9. In vitro assessment of antifungal drug resistance.

    PubMed

    Holmberg, K

    1986-01-01

    Several studies have documented the variability in the susceptibility pattern of fungi to antifungal drugs, and fungi possess resistance determinants to negate the effects of antifungal agents. In vitro assessment of both resistance and susceptibility are measured by suitable concentration endpoints of the antifungal drug, the minimal inhibitory concentration (MIC). MICs serve as the main parameter to define the fungistatic action on fungi growing in culture. For the antifungals used for treatment of local mycoses, the limit between a MIC value indicating susceptibility and one indicating resistance is usually determined empirically on the basis of the correlation between MIC values, and either positive or negative response to chemotherapy. The principles of susceptibility testing of fungi are essentially the same as those for bacteria. However, testing with fungi must deal with the fact that interpretation of the results is complicated by inherent differences in fungal morphology, growth rate, and optimal culture conditions. Several factors could adversely affect the test results and must be considered in the design of susceptibility testing of fungi. It is obvious when the present data on fungal susceptibility testing are reviewed that much more work on standardization of techniques and interpretation of results is necessary. This presentation will focus on the in vitro susceptibility testing for determining primary and secondary drug resistance of griseofulvin and azole antifungal agents, and the correlation between the activities of these antifungals in vitro and in vivo.

  10. The Mechanistic Targets of Antifungal Agents: An Overview

    PubMed Central

    Mazu, Tryphon K.; Bricker, Barbara A.; Flores-Rozas, Hernan; Ablordeppey, Seth Y.

    2016-01-01

    Pathogenic fungi are a major causative group for opportunistic infections (OIs). AIDS patients and other immunocompromised individuals are at risk for OIs, which if not treated appropriately, contribute to the mortality associated with their conditions. Several studies have indicated that the majority of HIV-positive patients contract fungal infections throughout the course of their disease. Similar observations have been made regarding the increased frequency of bone marrow and organ transplants, the use of antineoplastic agents, the excessive use of antibiotics, and the prolonged use of corticosteroids among others. In addition, several pathogenic fungi have developed resistance to current drugs. Together these have conspired to spur a need for developing new treatment options for OIs. To aid this effort, this article reviews the biological targets of current and emerging drugs and agents that act through these targets for the treatment of opportunistic fungal infections. PMID:26776224

  11. Comparison of the in vitro activities of newer triazoles and established antifungal agents against Trichophyton rubrum.

    PubMed

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

    2015-07-01

    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.

  12. Combination of different antifungal agents in oil-in-water emulsions to control strawberry jam spoilage.

    PubMed

    Ribes, Susana; Fuentes, Ana; Talens, Pau; Barat, Jose Manuel

    2018-01-15

    The combination of antifungal agents (cinnamon bark oil, zinc gluconate and trans-ferulic acid) in oil-in-water emulsions to control the fungal spoilage of strawberry jams, minimising essential oil's sensory impact, was evaluated in this work. The in vitro assays of free antifungal agents were performed against five fungal strains; meanwhile, the emulsions assays were conducted against Aspergillus niger given its strong resistance and its relevance in strawberry products. The emulsion formulated with 0.08mg/g of essential oil was able to inhibit mould growth after the incubation period. The incorporation of zinc gluconate or trans-ferulic acid, independently of the concentration used, allowed to reduce a 25% the amount of essential oil needed to inhibit the microbial growth. The combination of antifungal agents in the emulsions has demonstrated to be an effective alternative to reduce the amount of essential oil employed, maintaining the hygienic quality and sensory profile of the strawberry jam. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Interactions between Human Phagocytes and Candida albicans Biofilms Alone and in Combination with Antifungal Agents

    PubMed Central

    Katragkou, Aspasia; Kruhlak, Michael J.; Simitsopoulou, Maria; Chatzimoschou, Athanasios; Taparkou, Anna; Cotten, Catherine J.; Paliogianni, Fotini; Diza-Mataftsi, Eudoxia; Tsantali, Chaido; Walsh, Thomas J.; Roilides, Emmanuel

    2010-01-01

    Background Biofilm formation is an important component of vascular catheter infections caused by Candida albicans. Little is known about the interactions between human phagocytes and antifungal agents on Candida biofilms. Materials and Methods The interactions of C. albicans biofilms with human phagocytes alone and in combination with anidulafungin or voriconazole were investigated and compared with their corresponding planktonic counterparts using an in vitro biofilm model with clinical intravascular and green fluorescent protein (GFP) expressing strains. Phagocyte- and antifungal agent-mediated damages were determined by 2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]2H-tetrazolium-5-carboxanilide assay and structural effects visualized by confocal microscopy. Oxidative burst was evaluated by flow cytometric measurement of dihydrorhodamine (DHR)-123 oxidation and cytokine release measured by EIA. Results Phagocytes alone or in combination with antifungal agents induced less damage against biofilms as compared to planktonic cells. However, additive effects occurred between phagocytes and anidulafungin against Candida biofilms. Confocal microscopy demonstrated absence of phagocytosis within biofilms, but marked destruction caused by anidulafungin and phagocytes. Anidulafungin but not voriconazole elicited a TNF-α release from phagocytes compared with untreated biofilms. Conclusions Candida albicans within biofilms are more resistant to phagocytic host defenses but are susceptible to additive effects between phagocytes and an echinocandin. PMID:20415537

  14. Antifungal Activities of Antineoplastic Agents: Saccharomyces cerevisiae as a Model System To Study Drug Action

    PubMed Central

    Cardenas, Maria E.; Cruz, M. Cristina; Del Poeta, Maurizio; Chung, Namjin; Perfect, John R.; Heitman, Joseph

    1999-01-01

    Recent evolutionary studies reveal that microorganisms including yeasts and fungi are more closely related to mammals than was previously appreciated. Possibly as a consequence, many natural-product toxins that have antimicrobial activity are also toxic to mammalian cells. While this makes it difficult to discover antifungal agents without toxic side effects, it also has enabled detailed studies of drug action in simple genetic model systems. We review here studies on the antifungal actions of antineoplasmic agents. Topics covered include the mechanisms of action of inhibitors of topoisomerases I and II; the immunosuppressants rapamycin, cyclosporin A, and FK506; the phosphatidylinositol 3-kinase inhibitor wortmannin; the angiogenesis inhibitors fumagillin and ovalicin; the HSP90 inhibitor geldanamycin; and agents that inhibit sphingolipid metabolism. In general, these natural products inhibit target proteins conserved from microorganisms to humans. These studies highlight the potential of microorganisms as screening tools to elucidate the mechanisms of action of novel pharmacological agents with unique effects against specific mammalian cell types, including neoplastic cells. In addition, this analysis suggests that antineoplastic agents and derivatives might find novel indications in the treatment of fungal infections, for which few agents are presently available, toxicity remains a serious concern, and drug resistance is emerging. PMID:10515904

  15. Naturally occurring antifungal agents against Zygosaccharomyces bailii and their synergism.

    PubMed

    Fujita, Ken-Ichi; Kubo, Isao

    2005-06-29

    Polygodial was found to exhibit a fungicidal activity against a food spoilage yeast, Zygosaccharomyces bailii, with the minimum fungicidal concentration (MFC) of 50 microg/mL (0.17 mM). The time-kill curve study showed that polygodial was fungicidal at any growth stage. The primary action of polygodial comes from its ability to disrupt the native membrane-associated function of integral proteins as nonionic surface active agents (surfactants) followed by a decrease in plasma membrane fluidity. The fungicidal activity of polygodial was increased 128-fold in combination with a sublethal amount (equivalent of 1/2 MFC) of anethole and vice versa relative to the fungicidal activity of anethole. The fungicidal activity of sorbic acid was enhanced 512-fold in combination with 1/2 MFC of polygodial. Conversely, the fungicidal activity of polygodial was enhanced 128-fold in combination with 1/2 MFC of sorbic acid.

  16. 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.

  17. Azole-resistant aspergillosis.

    PubMed

    Warris, Adilia

    2015-06-01

    Azole-resistance in Aspergillus fumigatus is emerging and is becoming an increasing problem in the management of aspergillosis. Two types of development of resistance have been described; resistance acquired during azole treatment in an individual patient and through environmental exposure to fungicides. The main molecular mechanism of azole resistance in A. fumigatus is explained by mutations in the cyp51A-gene. The environmental route of resistance development is particularly worrying and may affect all patients whether azole exposed or naïve, and whether suffering from acute or chronic aspergillosis. No management guidelines to assist clinicians confronted with azole-resistant aspergillosis are available and pre-clinical and clinical evidence supporting treatment choices is scarce.

  18. Persistent and recurrent tinea corporis in children treated with combination antifungal/ corticosteroid agents.

    PubMed

    Alston, Sharonda J; Cohen, Bernard A; Braun, Marisa

    2003-01-01

    Combination antifungal/corticosteroid preparations are widely used by nondermatologists in the treatment of superficial fungal infections in patients of all ages. Over half of the prescriptions written for the most commonly used combination agent clotrimazole 1%/betamethasone diproprionate 0.05% cream (Lotrisone, Schering, Kenilworth, NJ) were prescribed for children younger than 4 years old. Our pediatric dermatology division has recently encountered a series of children with recurrent or persistent tinea corporis, especially tinea faciei, treated initially with combination antifungal/corticosteroid cream. All children evaluated for tinea corporis in a university hospital pediatric dermatology clinic from January through June 2001 were identified from the clinic registry for a retrospective chart review. Response to therapy was confirmed by telephone survey and/or follow-up visits at least 1 month after clearing of infection. Six children ranging in age from 4 to 11 years were evaluated for tinea corporis in a pediatric dermatology clinic at our institution during the 6-month period. All 6 children were diagnosed clinically by their pediatrician with tinea corporis and initially treated with clotrimazole 1%/betamethasone diproprionate 0.05% cream for 2 to 12 months. In our pediatric dermatology clinic, patients had their diagnosis confirmed with a positive potassium hydroxide preparation and were treated with one of several oral or topical antifungal agents with clearing of all tinea infections. The use of combination clotrimazole 1% cream/betamethasone diproprionate 0.05% cream (Lotrisone) for the treatment of tinea corporis may be associated with persistent/recurrent infection.

  19. Synthesis of Antifungal Agents from Xanthene and Thiazine Dyes and Analysis of Their Effects

    PubMed Central

    Kim, Joo Ran; Michielsen, Stephen

    2016-01-01

    Indoor fungi growth is an increasing home health problem as our homes are more tightly sealed. One thing that limits durability of the antifungal agents is the scarcity of reactive sites on many surfaces to attach these agents. In order to increase graft yield of photosensitizers to the fabrics, poly(acrylic acid-co-styrene sulfonic acid-co-vinyl benzyl rose bengal or phloxine B) were polymerized and then grafted to electrospun fabrics. In an alternative process, azure A or toluidine blue O were grafted to poly(acrylic acid), which was subsequently grafted to nanofiber-based and microfiber-based fabrics. The fabrics grafted with photosensitizers induced antifungal effects on all seven types of fungi in the order of rose bengal > phloxine B > toluidine blue O > azure A, which follows the quantum yield production of singlet oxygen for these photoactive dyes. Their inhibition rates for inactivating fungal spores decreased in the order of P. cinnamomi, T. viride, A. niger, A. fumigatus, C. globosum, P. funiculosum, and M. grisea, which is associated with lipid composition in membrane and the morphology of fungal spores. The antifungal activity was also correlated with the surface area of fabric types which grafted the photosensitizer covalently on the surface as determined by the bound color strength. PMID:28335371

  20. 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

  1. An evaluation of antifungal agents for the treatment of fungal contamination in indoor air environments.

    PubMed

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

    2015-06-02

    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 growth

  2. Comparison of the activities of four antifungal agents in an in vitro model of dermatophyte nail infection.

    PubMed

    Nowrozi, Hossein; Nazeri, Golrokh; Adimi, Parvaneh; Bashashati, Mohsen; Emami, Masood

    2008-01-01

    Onychomycosis is a difficult condition to treat and cure rates are disappointing. Moreover fungicidal action of antifungal agents in NCCLS assays and their rapid accumulation in nails in vivo are not compatible with the duration of treatment. This study aimed to find the effectiveness of 4 different antifungal agents in an in vitro model with some similarities to in vivo conditions. Strains of Trichophyton rubrum I-III, Trichophyton mentagrophytes (usual form), Trichophyton mentagrophytes 73, Epidermophyton Flucosom, Microsporum Canis, and Trichophyton Schoenleini which were isolated from the nails of patients, were hired. Inocula suspensions were prepared from 7 to 14 day-old cultures of dermatophytes. Antifungal agents including fluconazole, ketoconazole, terbinafine, and griseofulvin were obtained as standard powders. For each antifungal agent, initial MIC was calculated by registering the optical density for 10 two-fold serially diluted forms which was incubated with diluted fungal suspensions with RPMI 1640. Human nail powder inoculated with different strains and incubated in RPMI 1640 and different concentrations of antifungal drugs for 4 weeks. Final MIC at different steps of 1, 2, 3 and 4 weeks were investigated. The final MIC that resulted from the incubation of dermatophytes with nail powder was much more than the initial which was concluded from conventional MIC assay. Terbinafine had the lowest rate of initial and final MICs. The model described here may present more similar conditions to clinical fungal infections; therefore the results such as MIC may be more helpful for hiring the most effective antifungal agent.

  3. Augmenting the antifungal activity of an oxidizing agent with kojic Acid: control of penicillium strains infecting crops.

    PubMed

    Kim, Jong H; Chan, Kathleen L

    2014-11-12

    Oxidative treatment is one of the strategies for preventing Penicillium contamination in crops/foods. The antifungal efficacy of hydrogen peroxide (H2O2; oxidant) was investigated in Penicillium strains by using kojic acid (KA) as a chemosensitizing agent, which can enhance the susceptibility of pathogens to antifungal agents. Co-application of KA with H2O2 (chemosensitization) resulted in the enhancement of antifungal activity of either compound, when compared to the independent application of each agent alone. Of note, heat enhanced the activity of H2O2 to a greater extent during chemosensitization, whereby the minimum inhibitory or minimum fungicidal concentrations of H2O2 was decreased up to 4 or 13 fold, respectively, at 35-45 °C (heat), when compared to that at 28 °C (normal growth temperature). However, heat didn't increase the antifungal activity of KA, indicating specificity exists between heat and types of antifungals applied. The effect of chemosensitization was also strain-specific, where P. expansum (both parental and fludioxonil-resistant mutants) or P. italicum 983 exhibited relatively higher susceptibility to the chemosensitization, comparing to other Penicillium strains tested. Collectively, chemosensitization can serve as a potent antifungal strategy to lower effective dosages of toxic antifungal substances, such as H2O2. This can lead to coincidental lowering of environmental and health risks.

  4. Antifungal activity against Candida biofilms.

    PubMed

    Iñigo, Melania; Pemán, Javier; Del Pozo, Jose L

    2012-10-01

    Candida species have two distinct lifestyles: planktonic, and surface-attached communities called biofilms. Mature C. albicans biofilms show a complex three-dimensional architecture with extensive spatial heterogeneity, and consist of a dense network of yeast, hyphae, and pseudohyphae encased within a matrix of exopolymeric material. Several key processes are likely to play vital roles at the different stages of biofilm development, such as cell-substrate and cell-cell adherence, hyphal development, and quorum sensing. Biofilm formation is a survival strategy, since biofilm yeasts are more resistant to antifungals and environmental stress. Antifungal resistance is a multifactorial process that includes multidrug efflux pumps, target proteins of the ergosterol biosynthetic pathway. Most studies agree in presenting azoles as agents with poor activity against Candida spp. biofilms. However, recent studies have demonstrated that echinocandins and amphotericin B exhibit remarkable activity against C. albicans and Candida non-albicans biofilms. The association of Candida species with biofilm formation increases the therapeutic complexity of foreign body-related yeast infections. The traditional approach to the management of these infections has been to explant the affected device. There is a strong medical but also economical motivation for the development of novel anti-fungal biofilm strategies due to the constantly increasing resistance of Candida biofilms to conventional antifungals, and the high mortality caused by related infections. A better description of the extent and role of yeast in biofilms may be critical for developing novel therapeutic strategies in the clinical setting.

  5. [Triazole antifungal agents: practice guidelines of therapeutic drug monitoring and perspectives in treatment optimization].

    PubMed

    Scodavolpe, Simon; Quaranta, Sylvie; Lacarelle, Bruno; Solas, Caroline

    2014-01-01

    Antifungal triazole agents (fluconazole, voriconazole, itraconazole and posaconazole) are widely used for the management of invasive fungal infections (IFI). These drugs are indicated both for the prophylaxis and treatment of IFI, particularly in candidiasis and aspergillosis, major cause of mortality in immunocompromised patients. Due to a large interindividual pharmacokinetic variability leading to sub-therapeutic or toxic concentrations and to concentration-efficacy and/or -toxicity relationships, therapeutic drug monitoring (TDM) of antifungal triazole is fully justified. This review provides an overview of literature based data that confirm the usefulness of such TDM and its level of evidence as well as the practical guidelines for its implementation. In addition, we discuss the interest of new tools to improve the clinical management of IFI, such as genotyping tests optimizing initial voriconazole dosing regimen or the development of a new solid oral tablet of posaconazole improving its bioavailability and limiting absorption disorders.

  6. 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.

  7. Role of antifungal medicaments added to tissue conditioners: A systematic review.

    PubMed

    Iqbal, Zahid; Zafar, Muhammad Sohail

    2016-10-01

    The aim of this review is to investigate the current state of knowledge on the incorporation of antifungal agents into the tissue conditioners for the treatment of denture induced stomatitis. Studies reporting the incorporation of antifungal/antimicrobial agents in to tissue conditioners were included in the review. In order to search the studies on the topic "incorporation of antifungal agents in tissue conditioners for the treatment of denture induced stomatitis" ISI web of science, PubMed/MEDLINE, and Google-Scholar databases were searched from 1970 up to and including July 2015 using various keywords such as antifungal agents, tissue conditioners, Candida albicans, denture stomatitis, etc. Various studies reported the efficacy and effectiveness of adding conventional organic antifungal medicines (nystatin, azole group derivatives and chlorhexidine, antimicrobials/antifungals other than organic (silver zeolite, silver nano-particles, photo-catalysts and metallic oxides) and natural and herbal antimicrobials (tea tree oil, lemongrass essential oil and origanum oil) into various tissue conditioners. The review literature reported that incorporation of antifungal agents into tissue conditioners is effective with minimal or no effects on physical and mechanical properties of tissue conditioners. Incorporation of different antifungal medicaments to commercially available tissue conditioners can be recommended for the management of denture induced stomatitis. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  8. New Advances in Fatty Acids as Antimalarial, Antimycobacterial and Antifungal Agents

    PubMed Central

    Carballeira, N.M.

    2008-01-01

    This review deals with the most recent findings on the antimalarial, antimycobacterial, and antifungal properties of fatty acids, with particular emphasis on novel marine fatty acids. The first section deals with the most recent and some background literature on what has been the latest developments with respect to fatty acids as antimalarial agents and the importance of enzyme inhibition, in particular the inhibition of the enoyl-ACP-reductase (Fab I) of P. falciparum, the principal agent responsible for malaria. This section of the review also emphasizes the latest antimalarial research with the very long-chain Δ5,9 fatty acids from sponges. The second section of the review deals with the recent literature on the antimycobacterial activity of fatty acids and the importance of enzyme inhibition, in particular the inhibition of the enoyl-ACP-reductase (InhA) of M. tuberculosis for antimycobacterial activity. The inhibitory activities of the Δ5,9 fatty acids against InhA as well as that of the α-methoxylated fatty acids are also discussed. The importance of Δ5,9 fatty acids as topoisomerase I inhibitors and its connection to cancer is also reviewed. The last part of the review, the antifungal section, also emphasizes the most recent research with antifungal fatty acids and the importance of enzyme inhibition, in particular N-myristoyltransferase (NMT) inhibition, for antifungal activity. This last section of the review emphasizes the latest research with the α-methoxylated fatty acids but the importance of acetylenic fatty acids is also considered. PMID:18023422

  9. 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

  10. F901318 represents a novel class of antifungal drug that inhibits dihydroorotate dehydrogenase.

    PubMed

    Oliver, Jason D; Sibley, Graham E M; Beckmann, Nicola; Dobb, Katharine S; Slater, Martin J; McEntee, Laura; du Pré, Saskia; Livermore, Joanne; Bromley, Michael J; Wiederhold, Nathan P; Hope, William W; Kennedy, Anthony J; Law, Derek; Birch, Mike

    2016-10-25

    There is an important medical need for new antifungal agents with novel mechanisms of action to treat the increasing number of patients with life-threatening systemic fungal disease and to overcome the growing problem of resistance to current therapies. F901318, the leading representative of a novel class of drug, the orotomides, is an antifungal drug in clinical development that demonstrates excellent potency against a broad range of dimorphic and filamentous fungi. In vitro susceptibility testing of F901318 against more than 100 strains from the four main pathogenic Aspergillus spp. revealed minimal inhibitory concentrations of ≤0.06 µg/mL-greater potency than the leading antifungal classes. An investigation into the mechanism of action of F901318 found that it acts via inhibition of the pyrimidine biosynthesis enzyme dihydroorotate dehydrogenase (DHODH) in a fungal-specific manner. Homology modeling of Aspergillus fumigatus DHODH has identified a predicted binding mode of the inhibitor and important interacting amino acid residues. In a murine pulmonary model of aspergillosis, F901318 displays in vivo efficacy against a strain of A. fumigatus sensitive to the azole class of antifungals and a strain displaying an azole-resistant phenotype. F901318 is currently in late Phase 1 clinical trials, offering hope that the antifungal armamentarium can be expanded to include a class of agent with a mechanism of action distinct from currently marketed antifungals.

  11. Addressing current medical needs in invasive fungal infection prevention and treatment with new antifungal agents, strategies and formulations.

    PubMed

    Pitman, Stuart K; Drew, Richard H; Perfect, John R

    2011-09-01

    Introduction: Morbidity and mortality associated with invasive fungal infections (IFIs) remains unacceptably high. Such diseases represent a substantial burden to the healthcare system. New options are needed to address antifungal resistance in existing and emerging pathogens and improve treatment outcomes while minimizing drug-related toxicities and interactions. Awareness of new and potential future options is of great value for those healthcare professionals who care for patients with IFIs. Areas covered: A search of PubMed, infectious diseases conference abstracts and reference lists from relevant publications was conducted and relevant information abstracted. This review describes the limitations of existing systemic antifungal therapies (e.g., resistance, drug-drug interactions, drug-related toxicities) and summarizes data regarding several emerging antifungal compounds including (but not limited to) new triazoles (e.g. isavuconazole, ravuconazole), echinocandins (e.g., aminocandin) and nikkomycin Z. Agents in clinical trials such as (but not limited to) new triazoles (e.g., isavuconazole, ravuconazole), echinocandins (e.g., aminocandin) and nikkomycin are included. New formulations of existing drugs including reformulations of miconazole, posaconazole and amphotericin B are also reviewed. Finally, new or novel administration strategies for existing drugs such as combination antifungal therapy, antifungal dose escalation, adjunctive use of iron chelators and preemptive therapy are discussed. Expert opinion: All present antifungal agents have some deficiencies in antifungal spectra, toxicity, pharmacokinetics and/or drug-drug interactions, making them less than ideal for some fungal infections. Therefore, there remains an urgent need to find safe, effective, rapidly fungicidal, broad-spectrum antifungal agents with excellent pharmacodynamics to effectively eliminate the fungus from the body with short antifungal courses.

  12. Mitigation of human-pathogenic fungi that exhibit resistance to medical agents: can clinical antifungal stewardship help?

    PubMed

    Hull, Claire M; Purdy, Nicola J; Moody, Suzy C

    2014-01-01

    Reducing indiscriminate antimicrobial usage to combat the expansion of multidrug-resistant human-pathogenic bacteria is fundamental to clinical antibiotic stewardship. In contrast to bacteria, fungal resistance traits are not understood to be propagated via mobile genetic elements, and it has been proposed that a global explosion of resistance to medical antifungals is therefore unlikely. Clinical antifungal stewardship has focused instead on reducing the drug toxicity and high costs associated with medical agents. Mitigating the problem of human-pathogenic fungi that exhibit resistance to antimicrobials is an emergent issue. This article addresses the extent to which clinical antifungal stewardship could influence the scale and epidemiology of resistance to medical antifungals both now and in the future. The importance of uncharted selection pressure exerted by agents outside the clinical setting (agricultural pesticides, industrial xenobiotics, biocides, pharmaceutical waste and others) on environmentally ubiquitous spore-forming molds that are lesserstudied but increasingly responsible for drug-refractory infections is considered.

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

    SciTech Connect

    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

    2015-03-09

    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. In conclusion, 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.

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

    DOE PAGES

    Piotrowski, Jeff S.; Okada, Hiroki; Lu, Fachuang; ...

    2015-03-09

    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.more » 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. In conclusion, 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.« less

  15. Sensitivity of Candida albicans to essential oils: are they an alternative to antifungal agents?

    PubMed

    Bona, E; Cantamessa, S; Pavan, M; Novello, G; Massa, N; Rocchetti, A; Berta, G; Gamalero, E

    2016-12-01

    Candida albicans is an important opportunistic pathogen, responsible for the majority of yeast infections in humans. Essential oils, extracted from aromatic plants, are well-known antimicrobial agents, characterized by a broad spectrum of activities, including antifungal properties. The aim of this work was to assess the sensitivity of 30 different vaginal isolated strains of C. albicans to 12 essential oils, compared to the three main used drugs (clotrimazole, fluconazole and itraconazole). Thirty strains of C. albicans were isolated from vaginal swab on CHROMagar(™) Candida. The agar disc diffusion method was employed to determine the sensitivity to the essential oils. The antifungal activity of the essential oils and antifungal drugs (clotrimazole, itraconazole and fluconazole) were investigated using a microdilution method. Transmission and scanning electron microscopy analyses were performed to get a deep inside on cellular damages. Mint, basil, lavender, tea tree oil, winter savory and oregano essential oils inhibited both the growth and the activity of C. albicans more efficiently than clotrimazole. Damages induced by essential oils at the cellular level were stronger than those caused by clotrimazole. Candida albicans is more sensitive to different essential oils compared to the main used drugs. Moreover, the essential oil affected mainly the cell wall and the membranes of the yeast. The results of this work support the research for new alternatives or complementary therapies against vaginal candidiasis. © 2016 The Society for Applied Microbiology.

  16. 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.

  17. 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.

  18. 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

  19. [Could antifungal lock be useful in the management of candidiasis linked with catheters?].

    PubMed

    Cateau, Estelle; Rodier, Marie-Hélène; Imbert, Christine

    2012-01-01

    Fungal biofilms associated with inserted medical devices such as catheters, represent a major risk factor for candidemia. In addition, these biofilm yeasts show a decreased susceptibility to antifungal agents. Recently, a new therapeutic approach has emerged, the "lock therapy", based on the use of high concentrations of antimicrobials, instilled into the lumen of the catheter and left in place for 8 to 12 h. In vitro or in vivo studies have evaluated the interest of antifungal locks using amphotericin B, an azole or echinocandins. The promising results will permit us to discuss the relevance of this technique.

  20. Antifungal drug resistance among Candida species: mechanisms and clinical impact.

    PubMed

    Sanguinetti, Maurizio; Posteraro, Brunella; Lass-Flörl, Cornelia

    2015-06-01

    The epidemiology of Candida infections has changed in recent years. Although Candida albicans is still the main cause of invasive candidiasis in most clinical settings, a substantial proportion of patients is now infected with non-albicans Candida species. The various Candida species vary in their susceptibility to the most commonly used antifungal agents, and the intrinsic resistance to antifungal therapy seen in some species, along with the development of acquired resistance during treatment in others, is becoming a major problem in the management of Candida infection. A better understanding of the mechanisms and clinical impact of antifungal drug resistance is essential for the efficient treatment of patients with Candida infection and for improving treatment outcomes. Herein, we report resistance to the azoles and echinocandins among Candida species.

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

    PubMed Central

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

    2015-01-01

    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

  2. Laboratory tests of antifungal agents to treat tadpoles against the pathogen Batrachochytrium dendrobatidis .

    PubMed

    Geiger, Corina C; Schmidt, Benedikt R

    2013-04-11

    The fungus Batrachochytrium dendrobatidis (Bd), which is the etiological agent of the disease chytridiomycosis, is threatening both wild and captive amphibians. While there are some methods of treating amphibians in captivity, no method has yet been shown to be a promising treatment for amphibian populations in natural habitats. Here we present the results of a laboratory experiment in which we tested 2 antifungal agents that might be used to treat amphibians in the field. As a first step towards the goal of developing mitigation methods, we tested the efficiency of these agents in reducing Bd prevalence and loads (zoospore counts) in the laboratory. We exposed naturally infected tadpoles of the midwife toad Alytes obstetricans to different concentrations of the antifungal agents for 7 d. We found that Virkon Aquatic® affected neither Bd prevalence nor loads. At 0.625 ml l-1 of General Tonic®, prevalence was reduced to 60%, and infected animals had greatly reduced burdens. However, tadpole length was reduced by 19% and mass by 32% on average compared to the control group, suggesting a negative effect on fitness. Tadpole survival was not affected at 0.625 ml l-1 or 1.25 ml l-1, but was reduced to 60% at 2.5 ml l-1. Keeping animals in a dilution of General Tonic® for 7 d at a concentration of 0.625 ml l-1 might be an easy way to reduce zoospore counts in large numbers of animals at relatively low cost.

  3. 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

  4. A Cationic Polymer That Shows High Antifungal Activity against Diverse Human Pathogens.

    PubMed

    Rank, Leslie A; Walsh, Naomi M; Liu, Runhui; Lim, Fang Yun; Bok, Jin Woo; Huang, Mingwei; Keller, Nancy P; Gellman, Samuel H; Hull, Christina M

    2017-10-01

    Invasive fungal diseases are generally difficult to treat and often fatal. The therapeutic agents available to treat fungi are limited, and there is a critical need for new agents to combat these deadly infections. Antifungal compound development has been hindered by the challenge of creating agents that are highly active against fungal pathogens but not toxic to the host. Host defense peptides (HDPs) are produced by eukaryotes as a component of the innate immune response to pathogens and have served as inspiration for the development of many new antibacterial compounds. HDP mimics, however, have largely failed to exhibit potent and selective antifungal activity. Here, we present an HDP-like nylon-3 copolymer that is effective against diverse fungi while displaying only mild to moderate toxicity toward mammalian cells. This polymer is active on its own and in synergy with existing antifungal drugs against multiple species of Candida and Cryptococcus, reaching levels of efficacy comparable to those of the clinical agents amphotericin B and fluconazole in some cases. In addition, the polymer acts synergistically with azoles against different species of Aspergillus, including some azole-resistant strains. These findings indicate that nylon-3 polymers are a promising lead for development of new antifungal therapeutic strategies. Copyright © 2017 American Society for Microbiology.

  5. 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

  6. Antifungal drug discovery, six new molecules patented after 10 years of feast: why do we need new patented drugs apart from new strategies?

    PubMed

    Krcmery, Vladimir; Kalavsky, Erich

    2007-11-01

    After 10 years absence (between 1990-1999) of new antifungal agents and intensive research being introduced into clinical practice, 3 new azoles (Voriconazole - Pfizer, Posaconazole - Schering-Plough, Ravuconazole - Bristol-Myers Squibb) and 3 new echinocandins (Caspofungin - MSD, Anidulafungin - Astellas-Pfizer, Micafungin - Fujisawa) were patented. The question raises if we really need 6 new antifungal agents in such a short time? Perhaps, they are not here because we need them all, but because of at least fifteen years effort of many groups of investigators who successfully discovered, proved and introduced these agents to the drug market. Voriconazole (2000), Posaconazole (2005), Ravuconazole (2007) from the group of azoles; and Caspofungin (2002), Anidulafungin (2004) and Micafungin (2006) from the group of echinocandins, with unique mode(s) of action (cell wall synthesis inhibition) different from polyens, azoles, antimetabolites and new monoclonal antifungal antibody (Mycograb), were approved and introduced to the clinical practice. This paper contains some useful information regarding the recent patents on antifungal drug discovery, their current position in the strategy of treatment of invasive fungal infections is briefly reviewed.

  7. In-vitro Activity of 10 Antifungal Agents against 320 Dermatophyte Strains Using Microdilution Method in Tehran.

    PubMed

    Adimi, Parvaneh; Hashemi, Seyed Jamal; Mahmoudi, Mahmood; Mirhendi, Hossein; Shidfar, Mohammad Reza; Emmami, Masood; Rezaei-Matehkolaei, Ali; Gramishoar, Mohsen; Kordbacheh, Parivash

    2013-01-01

    Dermatophyte fungi are the etiologic agents of skin infections commonly referred to as ringworm. These infections are not dangerous but as a chronic cutaneous infections they may be difficult to treat and can also cause physical discomfort for patients. They are considered important as a public health problem as well. No information is available regarding the efficacy of antifungal agents against dermatophytes in Tehran. Therefore, in this study we evaluated the efficacy of 10 systemic and topical antifungal medications using CLSI broth microdilution method (M38-A). The antifungal agents used included griseofulvin, terbinafine, itraconazole, ketoconazole, fluconazole, voriconazole, clotrimazole, ciclopirox olamine, amorolfine and naftifine.Fifteen different species of dermatophytes which were mostly clinical isolates were used as follows; T. mentagrophytes, T. rubrum, E. floccosum, M. canis, T. verrucosum, T. tonsurans, M. gypseum, T. violaceum, M. ferruginum, M. fulvum, T. schoenleinii, M. racemosum, T. erinacei, T. eriotrephon and Arthroderma benhamiae. The mean number of fungi particles (conidia) inoculated was 1.25 ×10⁴ CFU/mL. Results were read after 7 days of incubation at 28 °C. According to the obtained results,itraconazole and terbinafine showed the lowest and fluconazole had the greatest MIC values for the most fungi tested. Based on the results, it is necessary to do more research and design a reliable standard method for determination of antifungal susceptibility to choose proper antibiotics with fewer side effects and decrease antifungal resistance and risk of treatment failure.

  8. In-vitro Activity of 10 Antifungal Agents against 320 Dermatophyte Strains Using Microdilution Method in Tehran

    PubMed Central

    Adimi, Parvaneh; Hashemi, Seyed Jamal; Mahmoudi, Mahmood; Mirhendi, Hossein; Shidfar, Mohammad Reza; Emmami, Masood; Rezaei-Matehkolaei, Ali; Gramishoar, Mohsen; Kordbacheh, Parivash

    2013-01-01

    Dermatophyte fungi are the etiologic agents of skin infections commonly referred to as ringworm. These infections are not dangerous but as a chronic cutaneous infections they may be difficult to treat and can also cause physical discomfort for patients. They are considered important as a public health problem as well. No information is available regarding the efficacy of antifungal agents against dermatophytes in Tehran. Therefore, in this study we evaluated the efficacy of 10 systemic and topical antifungal medications using CLSI broth microdilution method (M38-A). The antifungal agents used included griseofulvin, terbinafine, itraconazole, ketoconazole, fluconazole, voriconazole, clotrimazole, ciclopirox olamine, amorolfine and naftifine.Fifteen different species of dermatophytes which were mostly clinical isolates were used as follows; T. mentagrophytes, T. rubrum, E. floccosum, M. canis, T. verrucosum, T. tonsurans, M. gypseum, T. violaceum, M. ferruginum, M. fulvum, T. schoenleinii, M. racemosum, T. erinacei, T. eriotrephon and Arthroderma benhamiae. The mean number of fungi particles (conidia) inoculated was 1.25 ×10⁴ CFU/mL. Results were read after 7 days of incubation at 28 °C. According to the obtained results,itraconazole and terbinafine showed the lowest and fluconazole had the greatest MIC values for the most fungi tested. Based on the results, it is necessary to do more research and design a reliable standard method for determination of antifungal susceptibility to choose proper antibiotics with fewer side effects and decrease antifungal resistance and risk of treatment failure. PMID:24250660

  9. COMPARISON OF THE ACTIVITIES OF FOUR ANTIFUNGAL AGENTS IN AN IN VITRO MODEL OF DERMATOPHYTE NAIL INFECTION

    PubMed Central

    Nowrozi, Hossein; Nazeri, Golrokh; Adimi, Parvaneh; Bashashati, Mohsen; Emami, Masood

    2008-01-01

    Background: Onychomycosis is a difficult condition to treat and cure rates are disappointing. Moreover fungicidal action of antifungal agents in NCCLS assays and their rapid accumulation in nails in vivo are not compatible with the duration of treatment. Aims: This study aimed to find the effectiveness of 4 different antifungal agents in an in vitro model with some similarities to in vivo conditions. Materials and Methods: Strains of Trichophyton rubrum I-III, Trichophyton mentagrophytes (usual form), Trichophyton mentagrophytes 73, Epidermophyton Flucosom, Microsporum Canis, and Trichophyton Schoenleini which were isolated from the nails of patients, were hired. Inocula suspensions were prepared from 7 to 14 day-old cultures of dermatophytes. Antifungal agents including fluconazole, ketoconazole, terbinafine, and griseofulvin were obtained as standard powders. For each antifungal agent, initial MIC was calculated by registering the optical density for 10 two-fold serially diluted forms which was incubated with diluted fungal suspensions with RPMI 1640. Human nail powder inoculated with different strains and incubated in RPMI 1640 and different concentrations of antifungal drugs for 4 weeks. Final MIC at different steps of 1, 2, 3 and 4 weeks were investigated. Results: The final MIC that resulted from the incubation of dermatophytes with nail powder was much more than the initial which was concluded from conventional MIC assay. Terbinafine had the lowest rate of initial and final MICs. Conclusion: The model described here may present more similar conditions to clinical fungal infections; therefore the results such as MIC may be more helpful for hiring the most effective antifungal agent. PMID:19882010

  10. Genetic diversity and antifungal susceptibility profiles in causative agents of sporotrichosis.

    PubMed

    Rodrigues, Anderson Messias; de Hoog, G Sybren; de Cássia Pires, Débora; Brihante, Raimunda Sâmia Nogueira; Sidrim, José Júlio da Costa; Gadelha, Marcos Fabio; Colombo, Arnaldo Lopes; de Camargo, Zoilo Pires

    2014-04-23

    Sporotrichosis is a chronic subcutaneous mycosis of humans and animals, which is typically acquired by traumatic inoculation of plant material contaminated with Sporothrix propagules, or via animals, mainly felines. Sporothrix infections notably occur in outbreaks, with large epidemics currently taking place in southeastern Brazil and northeastern China. Pathogenic species include Sporothrix brasiliensis, Sporothrix schenckii s. str., Sporothrix globosa, and Sporothrix luriei, which exhibit differing geographical distribution, virulence, and resistance to antifungals. The phylogenetically remote species Sporothrix mexicana also shows a mild pathogenic potential. We assessed a genetically diverse panel of 68 strains. Susceptibility profiles of medically important Sporothrix species were evaluated by measuring the MICs and MFCs for amphotericin B (AMB), fluconazole (FLC), itraconazole (ITC), voriconazole (VRC), posaconazole (PCZ), flucytosine (5FC), and caspofungin (CAS). Haplotype networks were constructed to reveal interspecific divergences within clinical Sporothrix species to evaluate genetically deviant isolates. ITC and PCZ were moderately effective against S. brasiliensis (MIC90 = 2 and 2 μg/mL, respectively) and S. schenckii (MIC90 = 4 and 2 μg/mL, respectively). PCZ also showed low MICs against the rare species S. mexicana. 5FC, CAS, and FLC showed no antifungal activity against any Sporothrix species. The minimum fungicidal concentration ranged from 2 to >16 μg/mL for AMB against S. brasiliensis and S. schenckii, while the MFC90 was >16 μg/mL for ITC, VRC, and PCZ. Sporothrix species in general showed high degrees of resistance against antifungals. Evaluating a genetically diverse panel of strains revealed evidence of multidrug resistant phenotypes, underlining the need for molecular identification of etiologic agents to predict therapeutic outcome.

  11. Competition assays revealed Paenibacillus pasadenensis strain R16 as a novel antifungal agent.

    PubMed

    Passera, Alessandro; Venturini, Giovanni; Battelli, Giovanna; Casati, Paola; Penaca, Francesca; Quaglino, Fabio; Bianco, Piero Attilio

    2017-05-01

    The development of new sustainable containment strategies of plant diseases is very important to guarantee food security while reducing the environmental impact of agriculture. Research of new biocontrol agents is a long and difficult process that involves several steps that start from the identification of possible candidates which, for example, show antibiotic activities, and ends with in field, large scale trials. In this study, the plant growth promoting potential and antifungal effect exerted by a novel, putative candidate biocontrol agent, strain R16, identified as Paenibacillus pasadenensis by sequence analysis of 16S rRNA and rpoB genes, against three important plant pathogenic fungi (Botrytis cinerea, Fusarium verticillioides, and Phomopsis viticola), were assessed. Biochemical assays to determine plant growth promoting potential gave negative results for siderophore production and phosphate solubilization, and positive results for ACC-deamination and IAA production. Further biochemical assays for endophytic lifestyle and antifungal activity gave positive results for catalase and chitinase activity, respectively. In vitro antagonism assays showed that strain R16 is effective against B. cinerea, reducing mycelial growth both in dual-culture and through volatile substances, characterized to be mostly composed by farnesol, and inhibiting conidia germination. Good antagonistic potential was also observed in vitro towards P. viticola, but not towards F. verticillioides. Moreover, in vivo assays confirmed the strain R16 activity reduced the infection rate on B. cinerea-inoculated berries. The obtained results firstly proved that P. pasadenesis strain R16 is a putative plant growth promoter and effective against phytopathogenic fungi. Further studies will be needed to investigate the possible application of this strain as a biocontrol agent. Copyright © 2017 Elsevier GmbH. All rights reserved.

  12. [Ajoene the main active compound of garlic (Allium sativum): a new antifungal agent].

    PubMed

    Ledezma, Eliades; Apitz-Castro, Rafael

    2006-06-01

    The curative properties of garlic in medicine have been known for a long time. But, it was only in the last three decades when garlic properties were seriously investigated confirming its potential as therapeutic agent. Allicin, ajoene, thiosulfinates and a wide range of other organosulphurate compounds, are known to be the constituents linked to the garlic properties. Regarding the biochemical properties of these compounds, ajoene [(E,Z)-4,5,9 Trithiadodeca 1,6,11 Triene 9-oxide] is stable in water, and it can be obtained by chemical synthesis. There is evidence that some of the garlic constituents exert a wide variety of effects on different biological systems. However, ajoene is the garlic compound related to more biological activities, as showed in in vitro and in vivo systems. Those studies found that ajoene has antithrombotic, anti-tumoral,antifungal, and antiparasitic effects. This study deals with a recently described antifungal property of ajoene, and its potential use in clinical trails to treat several fungal infections.

  13. Chitosan silver nanocomposite (CAgNC) as an antifungal agent against Candida albicans.

    PubMed

    Kulatunga, Dcm; Dananjaya, Shs; Godahewa, G I; Lee, Jehee; De Zoysa, Mahanama

    2017-02-01

    Due to limited numbers of antifungal drugs and emergence of drug resistance have directed to develop nonconventional therapeutic agents against fungal pathogen Candida albicans. In this study, anticandidal activity of chitosan silver nanocomposite (CAgNC) was tested against C. albicans Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of CAgNC were determined as 25 and 100 μg/ml, respectively. Electron microscopic image results confirmed the ultrastructural cell wall deformities and injuries caused by CAgNC. Propidium iodide (PI) penetration into the CAgNC treated cells could be considered as an evidence for loss of cell membrane integrity and cell death at MFC. Level of intracellular reactive oxygen species (ROS) was increased, while cell viability was decreased with the increased of CAgNC concentrations. In our protein profile results, several induced proteins were observed under CAgNC treatment, and they could be related to multidrug and stress resistant proteins such as CDR1 (55 kDa) and CaHSP70 based on the protein band size. CAgNC mediated cell wall damage, loss of cell membrane integrity, elevated ROS level, and associated oxidative stress have been identified as the main causative factors for the anticandidal activity. Overall results from our study indicated that CAgNC could affect negatively on physiological and biochemical functions of C. albicans suggesting CAgNC as a potential alternative for antifungal chemotherapy.

  14. Toxicity of Topical Antifungal Agents to Stratified Human Cultivated Corneal Epithelial Sheets

    PubMed Central

    Kimakura, Mikiko; Yokoo, Seiichi; Nakagawa, Suguru; Yamagami, Satoru; Amano, Shiro

    2014-01-01

    Abstract Purpose: Prolonged use of topical antifungal agents may compromise corneal epithelial integrity. Here, we used an in vitro model of human stratified corneal epithelium to compare the ocular toxicity profiles of 4 different antifungal eye drops. Methods: Human corneal epithelial cell sheets were cultured in a serum-free medium containing 0.1% micafungin, 1% voriconazole, 5% pimaricin, 0.1% amphotericin B, or controls (saline or 5% glucose). Cell viability and barrier function were measured by WST-1 assay and carboxyfluorescein permeability assay, respectively. Cell migration was measured on a wound healing assay. Results: WST-1 assay and carboxyfluorescein permeability assay revealed that amphotericin B was the most toxic drug, followed by pimaricin, micafungin, and voriconazole. Cell migration on a wound healing assay was decreased in the following order, amphotericin B, pimaricin, micafungin, and voriconazole. Conclusions: Topical micafungin and voriconazole appeared to be the least toxic to the corneal epithelium. Drug prescription should consider not only fungal species and susceptibility but also ocular toxicity and stage of treatment. PMID:25280055

  15. Effect of chitosan and its derivatives as antifungal and preservative agents on postharvest green asparagus.

    PubMed

    Qiu, Miao; Wu, Chu; Ren, Gerui; Liang, Xinle; Wang, Xiangyang; Huang, Jianying

    2014-07-15

    The antifungal activity and effect of high-molecular weight chitosan (H-chitosan), low-molecular weight chitosan (L-chitosan) and carboxymethyl chitosan (C-chitosan) coatings on postharvest green asparagus were evaluated. L-chitosan and H-chitosan efficiently inhibited the radial growth of Fusarium concentricum separated from postharvest green asparagus at 4 mg/ml, which appeared to be more effective in inhibiting spore germination and germ tube elongation than that of C-chitosan. Notably, spore germination was totally inhibited by L-chitosan and H-chitosan at 0.05 mg/ml. Coated asparagus did not show any apparent sign of phytotoxicity and maintained good quality over 28 days of cold storage, according to the weight loss and general quality aspects. Present results inferred that chitosan could act as an attractive preservative agent for postharvest green asparagus owing to its antifungal activity and its ability to stimulate some defense responses during storage. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. A chemically modified tetracycline (CMT-3) is a new antifungal agent.

    PubMed

    Liu, Yu; Ryan, Maria E; Lee, Hsi-Ming; Simon, Sanford; Tortora, George; Lauzon, Carol; Leung, Michael K; Golub, Lorne M

    2002-05-01

    Several chemically modified tetracycline analogs (CMTs), which were chemically modified to eliminate their antibacterial efficacy, were unexpectedly found to have antifungal properties. Of 10 CMTs screened in vitro, all exhibited antifungal activities, although their efficacies varied. Among these compounds, CMT-315, -3, and -308 were found to be the most potent as antifungal agents. The MICs of CMT-3 against 47 strains of fungi in vitro were determined by using amphotericin B (AMB) and doxycycline as positive and negative controls, respectively. The MICs of CMT-3 were generally found to be between 0.25 and 8.00 microg/ml, a range that approximates the blood levels of this drug when administrated orally to humans. Of all the yeast species tested to date, Candida albicans showed the greatest sensitivity to CMT-3. The filamentous species most susceptible to CMT-3 were found to be Epidermophyton floccosum, Microsporum gypseum, Pseudallescheria boydii, a Penicillium sp., Scedosporium apiospermum, a Tricothecium sp., and Trichophyton rubrum. Growth inhibition of C. albicans by CMT-3, determined by a turbidity assay, indicated a 50% inhibitory concentration of 1 microg/ml. Thirty-nine strains, including 20 yeasts and 19 molds, were used to measure viability (the ability to grow after treatment with a drug) inhibition by CMT-3 and AMB. CMT-3 exhibited fungicidal activity against most of these fungi, especially the filamentous fungi. Eighty-four percent (16 of 19) of the filamentous fungi tested showed more than 90% inhibition of viability by CMT-3. In contrast, AMB showed fungicidal activity against all yeasts tested. However, most of the filamentous fungi (16 of 19) showed less than 50% inhibition of viability by AMB, indicating that AMB is fungistatic against most of these filamentous fungi. To begin to identify the sites in fungal cells affected by CMT-3, C. albicans and a Penicillium sp. were incubated with the compound at 35 degrees C, and then the fluorescence of

  17. Pharmacodynamics of the Novel Antifungal Agent F901318 for Acute Sinopulmonary Aspergillosis Caused by Aspergillus flavus.

    PubMed

    Negri, Clara E; Johnson, Adam; McEntee, Laura; Box, Helen; Whalley, Sarah; Schwartz, Julie A; Ramos-Martín, V; Livermore, Joanne; Kolamunnage-Dona, Ruwanthi; Colombo, Arnaldo L; Hope, William W

    2017-09-12

    Aspergillus flavus is one of the most common agents of invasive aspergillosis and is associated with high mortality. The orotomides are a new class of antifungal agents with a novel mechanism of action. An understanding of the pharmacodynamics of the lead compound F901318 is required to plan safe and effective regimens for clinical use. The pharmacokinetics (PK) and pharmacodynamics (PD) of F901318 were evaluated by developing new in vitro and in vivo models of invasive fungal sinusitis. Galactomannan was used as a pharmacodynamic endpoint in all models. Mathematical PK-PD models were used to describe dose-exposure-response relationships. F901318 MICs ranged from 0.015 to 0.06 mg/L. F901318 induced a concentration-dependent decline in galactomannan. In the in vitro model a Cmin:MIC of 10 resulted in suppression of galactomannan; whereas, values of approximately 10 and 9-19 when assessed by survival of mice or the decline in galactomannan, respectively were equivalent or exceeded the effect induced by posaconazole. There was histological clearance of lung tissue that was consistent with the effects of F901318 on galactomannan. F901318 is a potential new agent for the treatment of invasive infections caused by Aspergillus flavus with pharmacodynamics that are comparable to other first-line triazole agents.

  18. The Role of Topical Antifungal Therapy for Onychomycosis and the Emergence of Newer Agents

    PubMed Central

    2014-01-01

    Onychomycosis is a common infection of the nail unit that is usually caused by a dermatophyte (tinea unguium) and most frequently affects toenails in adults. In most cases, onychomycosis is associated with limited treatment options that are effective in achieving complete clearance in many cases. In addition, recurrence rates are high in the subset of treated patients who have been effectively cleared, usually with an oral antifungal agent. There has been a conspicuous absence of medical therapies approved in the United States since the introduction of topical ciclopirox (8% nail lacquer), with no new effective agents introduced for more than 10 years. Fortunately, newer agents and formulations have been under formal development. While patients might prefer a topical therapy, efficacy with ciclopirox 8% nail lacquer, the only available agent until the very recent approval of efinaconazole 10% solution, has been disappointing. The poor therapeutic outcomes achieved with ciclopirox 8% nail lacquer were not unexpected as the cure rates achieved in the clinical trials were unimpressive, despite concomitant nail debridement, which was an integral part of the pivotal trials with ciclopirox 8% nail lacquer. Efinaconazole 10% solution and tavaborole 5% solution are new topical antifungals specifically developed for the treatment of dermatophyte onychomycosis. In Phase 3 clinical trials, both newer agents were applied once daily for 48 weeks without concomitant nail debridement. Mycologic cure rates with efinaconazole 10% solution are markedly superior to what was achieved with ciclopirox 8% nail lacquer. To add, they appear to be nearly comparable to those achieved with oral itraconazole in pivotal clinical trials. However, it is important to remember that direct comparisons between different studies are not conclusive, are not generally considered to be scientifically sound, and may not be entirely accurate due to differences in study design and other factors. Well

  19. Potential Applications and Antifungal Activities of Engineered Nanomaterials against Gray Mold Disease Agent Botrytis cinerea on Rose Petals.

    PubMed

    Hao, Yi; Cao, Xiaoqian; Ma, Chuanxin; Zhang, Zetian; Zhao, Na; Ali, Arbab; Hou, Tianqi; Xiang, Zhiqian; Zhuang, Jian; Wu, Sijie; Xing, Baoshan; Zhang, Zhao; Rui, Yukui

    2017-01-01

    Nanoparticles (NPs) have great potential for use in the fields of biomedicine, building materials, and environmental protection because of their antibacterial properties. However, there are few reports regarding the antifungal activities of NPs on plants. In this study, we evaluated the antifungal roles of NPs against Botrytis cinerea, which is a notorious worldwide fungal pathogen. Three common carbon nanomaterials, multi-walled carbon nanotubes, fullerene, and reduced graphene oxide, and three commercial metal oxidant NPs, copper oxide (CuO) NPs, ferric oxide (Fe2O3) NPs, and titanium oxides (TiO2) NPs, were independently added to water-agar plates at 50 and 200-mg/L concentrations. Detached rose petals were inoculated with spores of B. cinerea and co-cultured with each of the six nanomaterials. The sizes of the lesions on infected rose petals were measured at 72 h after inoculation, and the growth of fungi on the rose petals was observed by scanning electron microscopy. The six NPs inhibited the growth of B. cinerea, but different concentrations had different effects: 50 mg/L of fullerene and CuO NPs showed the strongest antifungal properties among the treatments, while 200 mg/L of CuO and Fe2O3 showed no significant antifungal activities. Thus, NPs may have antifungal activities that prevent B. cinerea infections in plants, and they could be used as antifungal agents during the growth and post-harvesting of roses and other flowers.

  20. Potential Applications and Antifungal Activities of Engineered Nanomaterials against Gray Mold Disease Agent Botrytis cinerea on Rose Petals

    PubMed Central

    Hao, Yi; Cao, Xiaoqian; Ma, Chuanxin; Zhang, Zetian; Zhao, Na; Ali, Arbab; Hou, Tianqi; Xiang, Zhiqian; Zhuang, Jian; Wu, Sijie; Xing, Baoshan; Zhang, Zhao; Rui, Yukui

    2017-01-01

    Nanoparticles (NPs) have great potential for use in the fields of biomedicine, building materials, and environmental protection because of their antibacterial properties. However, there are few reports regarding the antifungal activities of NPs on plants. In this study, we evaluated the antifungal roles of NPs against Botrytis cinerea, which is a notorious worldwide fungal pathogen. Three common carbon nanomaterials, multi-walled carbon nanotubes, fullerene, and reduced graphene oxide, and three commercial metal oxidant NPs, copper oxide (CuO) NPs, ferric oxide (Fe2O3) NPs, and titanium oxides (TiO2) NPs, were independently added to water-agar plates at 50 and 200-mg/L concentrations. Detached rose petals were inoculated with spores of B. cinerea and co-cultured with each of the six nanomaterials. The sizes of the lesions on infected rose petals were measured at 72 h after inoculation, and the growth of fungi on the rose petals was observed by scanning electron microscopy. The six NPs inhibited the growth of B. cinerea, but different concentrations had different effects: 50 mg/L of fullerene and CuO NPs showed the strongest antifungal properties among the treatments, while 200 mg/L of CuO and Fe2O3 showed no significant antifungal activities. Thus, NPs may have antifungal activities that prevent B. cinerea infections in plants, and they could be used as antifungal agents during the growth and post-harvesting of roses and other flowers. PMID:28824670

  1. Patterns of in vitro activity of itraconazole and imidazole antifungal agents against Candida albicans with decreased susceptibility to fluconazole from Spain.

    PubMed

    Martinez-Suarez, J V; Rodriguez-Tudela, J L

    1995-07-01

    Two groups of recent clinical isolates of Candida albicans consisting of 101 isolates for which fluconazole MICs were < or = 0.5 microgram/ml (n = 50) and > or = 4.0 micrograms/ml (n = 51), respectively, were compared for their susceptibilities to fluconazole, clotrimazole, miconazole, ketoconazole, and itraconazole. Susceptibility tests were performed by a photometer-read broth microdilution method with an improved RPMI 1640 medium supplemented with 18 g of glucose per liter (RPMI-2% glucose; J. L. Rodríguez-Tudela and J. V. Martínez-Suárez, Antimicrob. Agents Chemother. 38:45-48, 1994). Preparation of drugs, basal medium, and inocula was done by the recommendations of the National Committee for Clinical Laboratory Standards. The MIC endpoint was calculated objectively from the turbidimetric data read at 24 h as the lowest drug concentration at which growth was just equal to or less than 20% of that in the positive control well (MIC 80%). In vitro susceptibility testing separated azole-susceptible strains from the strains with decreased susceptibilities to azoles if wide ranges of concentrations (20 doubling dilutions) were used for ketoconazole, miconazole, and clotrimazole. By comparison with isolates for which fluconazole MICs were < or = 0.5 microgram/ml, those isolates for which fluconazole MICs were > or = 4.0 micrograms/ml were in general less susceptible to other azole drugs, but different patterns of decreased susceptibility were found, including uniform increases in the MICs of all azole derivatives, higher MICs of several azoles but not others, and elevated MICs of fluconazole only. On the other hand, decreased susceptibility to any other azole drug was never found among strains for which MICs of fluconazole were lower.

  2. 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.

  3. Discovery of an Octahedral Silicon Complex as a Potent Antifungal Agent.

    PubMed

    Fu, Chen; Fu, Bin; Peng, Xixi; Liao, Guojian

    2017-04-15

    Octahedral transition metal complexes have been shown to have tremendous applications in chemical biology and medicinal chemistry. Meanwhile, structural transition metals can be replaced by inert octahedral silicon in a proof-of-principle study. We here introduce the first example of octahedral silicon complexes, which can very well serve as an efficient antimicrobial agent. The typical silicon arenediolate complex 1 {[(phen)₂Si(OO)](PF₆)₂, with phen = 1,10-phenanthroline, OO = 9,10-phenanthrenediolate} exhibited significant inhibition towards the growth of Cryptococcus neoformans with MIC and MFC values of 4.5 and 11.3 μM, respectively. Moreover, it was fungicidal against both proliferative and quiescent Cryptococcus cells. This work may set the stage for the development of novel antifungal drugs based upon hexacoodinate silicon scaffolds.

  4. 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.

  5. Past, Recent Progresses and Future Perspectives of Nanotechnology Applied to Antifungal Agents.

    PubMed

    Roque, Luís; Molpeceres, Jesús; Reis, Cláudia; Rijo, Patrícia; Reis, Catarina Pinto

    2017-02-01

    Candida species remain a significant cause of nosocomial bloodstream infections, associated with prolonged hospital stay in the ICU and high healthcare cost. The incidence of Candida is very high in certain risk groups of patients (AIDS, diabetes, cancer, etc.). Recent developments of nanotechnology have strongly contributed to the design of new multifunctional drug carriers that improve drug bioavailability through a controlled and prolonged release profile or even through a more specific targeted delivery of the antifungal agent. Those types of systems have strongly increased with a progressive generation of new structures, permitting the conjunction of new materials, biomolecules, physical and chemical techniques, for better outcomes. Nanotechnology shows expanded possibilities within the medical field and in the case of the yeast infections it may overcome several issues related with the fungal proliferation or higher inhibition of the pathogen causing the infection. This review covers a period of the most representative research of Candidiasis since 1993 to the present.

  6. Structure-Guided Development of Efficacious Antifungal Agents Targeting Candida Glabrata Dihydrofolate Reductase

    SciTech Connect

    Liu, J.; Bolstad, D; Smith, A; Priestley, N; Wright, D; Anderson, A

    2008-01-01

    Candida glabrata is a lethal fungal pathogen resistant to many antifungal agents and has emerged as a critical target for drug discovery. Over the past several years, we have been developing a class of propargyl-linked antifolates as antimicrobials and hypothesized that these compounds could be effective inhibitors of dihydrofolate reductase (DHFR) from C. glabrata. We initially screened a small collection of these inhibitors and found modest levels of potency. Subsequently, we determined the crystal structure of C. glabrata DHFR bound to a representative inhibitor with data to 1.6 A resolution. Using this structure, we designed and synthesized second-generation inhibitors. These inhibitors bind the C. glabrata DHFR enzyme with subnanomolar potency, display greater than 2000-fold levels of selectivity over the human enzyme, and inhibit the growth of C. glabrata at levels observed with clinically employed therapeutics.

  7. Susceptibility of clinical Candida species isolates to antifungal agents by E-test, Southern Iran: A five year study.

    PubMed

    Badiee, P; Alborzi, A

    2011-12-01

    The incidence of fungal infections in immunocompromised patients, especially by Candida species, has increased in recent years. This study was designed to identify Candida species and determine antifungal susceptibility patterns of 595 yeast strains isolated from various clinical specimens. Identification of the isolates were determined by the API 20 C AUX kit and antifungal susceptibilities of the species to fluconazole, amphotericin B, ketoconazole, itraconazole, voriconazole, and caspofungin were determined by the agar-based E-test method. Candida albicans (48%) was the most frequently isolated species, followed by Candida kruzei (16.1%), Candida glabrata (13.5%), Candida kefyr (7.4%), Candida parapsilosis (4.8%), Candida tropicalis (1.7%) and other species (8.5%). Resistance varies depending on the species and the respective antifungal agents. Comparing the MIC90 for all the strains, the lower MIC90 was observed for caspofungin (0.5 µg/ml). The MIC90 for all Candida species were 64 µg/ml for fluconazole, 0.75 µg/ml for amphotericin B, 4 µg/ml for ketoconazole, 4 µg/ml for itraconazole, and 2 µg/ml for voriconazole. Species definition and determination of antifungal susceptibility patterns are advised for the proper management and treatment of patients at risk for systemic candidiasis. Resistance to antifungal agents is an alarming sign for the emerging common nosocomial fungal infections.

  8. Susceptibility of clinical Candida species isolates to antifungal agents by E-test, Southern Iran: A five year study

    PubMed Central

    Badiee, P; Alborzi, A

    2011-01-01

    Background and Objectives The incidence of fungal infections in immunocompromised patients, especially by Candida species, has increased in recent years. This study was designed to identify Candida species and determine antifungal susceptibility patterns of 595 yeast strains isolated from various clinical specimens. Material and Methods Identification of the isolates were determined by the API 20 C AUX kit and antifungal susceptibilities of the species to fluconazole, amphotericin B, ketoconazole, itraconazole, voriconazole, and caspofungin were determined by the agar-based E-test method. Results Candida albicans (48%) was the most frequently isolated species, followed by Candida kruzei (16.1%), Candida glabrata (13.5%), Candida kefyr (7.4%), Candida parapsilosis (4.8%), Candida tropicalis (1.7%) and other species (8.5%). Resistance varies depending on the species and the respective antifungal agents. Comparing the MIC90 for all the strains, the lower MIC90 was observed for caspofungin (0.5 µg/ml). The MIC90 for all Candida species were 64 µg/ml for fluconazole, 0.75 µg/ml for amphotericin B, 4 µg/ml for ketoconazole, 4 µg/ml for itraconazole, and 2 µg/ml for voriconazole. Conclusions Species definition and determination of antifungal susceptibility patterns are advised for the proper management and treatment of patients at risk for systemic candidiasis. Resistance to antifungal agents is an alarming sign for the emerging common nosocomial fungal infections. PMID:22530086

  9. Empiric antifungal therapy in patients with febrile neutropenia.

    PubMed

    Ferrara, Jenna J; MacDougall, Conan; Gallagher, Jason C

    2011-04-01

    Invasive fungal infections, most commonly candidiasis or aspergillosis, are a major cause of morbidity and mortality among patients with neutropenia. Difficulty in diagnosing invasive fungal infections in these patients complicates decisions regarding pharmacotherapy. Because of the difficult diagnosis and the significant morbidity and mortality of fungal infections in patients with neutropenia, systemic antifungal agents are used as empiric antifungal therapy in patients with febrile neutropenia who are not responding to antibacterial therapy. The pharmacotherapy of invasive fungal infections has evolved rapidly within the past several years as numerous antifungal agents--different formulations of amphotericin B, azoles, and echinocandins--have become available for use as empiric antifungal therapy in patients with febrile neutropenia. Various levels of evidence support the use of these agents for this indication. Their use is limited, however, by drug intolerance, drug interactions, adverse-event profiles, and limited activity with some mold species. Thus, considerations for selecting an antifungal drug for empiric use in patients with febrile neutropenia should include the epidemiology of fungal infections in the individual patient's institution and the specific clinical circumstances of the patient.

  10. 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

  11. Otomycosis in the north of Iran: common pathogens and resistance to antifungal agents.

    PubMed

    Nemati, Shadman; Hassanzadeh, Rasool; Khajeh Jahromi, Sina; Delkhosh Nasrollah Abadi, Azimeh

    2014-05-01

    Otomycosis as a kind of external otitis can be caused by various species of fungi. To use the appropriate treatment, it is necessary to identify the causal agent of otomycosis. The aim of this study was to determine the pathogens that caused otomycosis and also the efficacy of different antifungal agents. 100 patients with diagnosis of otomycosis/otitis extern were entered in this study. Bacterial culture was performed by eosin methylene blue agar, blood agar; and Sabouraud dextrose agar was used to culture the fungal agents. Minimum inhibitory concentration test also was performed to determine the efficacy of Clotrimazole, Fluconazole, Ketoconazole and Nystatin on the fungal pathogens. Otomycosis was confirmed in 43% of patients by positive culture. The most prevalent fungal pathogen was Aspergillus niger which was sensitive to Clotrimazole, Fluconazole, Ketoconazole. Candida albicans was sensitive to all drugs, in which, the most sensitivity was due to fluconazole. The most frequent fungal pathogen in our otomycosis cases is A. niger, and most of fungi that caused otomycosis are sensitive to clotrimazole.

  12. 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.

  13. In vitro susceptibility testing of dermatophytes isolated in Goiania, Brazil, against five antifungal agents by broth microdilution method.

    PubMed

    Araújo, Crystiane Rodrigues; Miranda, Karla Carvalho; Fernandes, Orionalda de Fatima Lisboa; Soares, Ailton José; Silva, Maria do Rosário Rodrigues

    2009-01-01

    The antifungal activities of fluconazole, itraconazole, ketoconazole, terbinafine and griseofulvin were tested by broth microdilution technique, against 60 dermatophytes isolated from nail or skin specimens from Goiania city patients, Brazil. In this study, the microtiter plates were incubated at 28 masculineC allowing a reading of the minimal inhibitory concentration (MIC) after four days of incubation for Trichophyton mentagrophytes and five days for T. rubrum and Microsporum canis. Most of the dermatophytes had uniform patterns of susceptibility to the antifungal agents tested. Low MIC values as 0.03 microg/mL were found for 33.3%, 31.6% and 15% of isolates for itraconazole, ketoconazole and terbinafine, respectively.

  14. 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

  15. In vitro response of cutaneous mycosis fungal agents to the most widely used systemic antifungals in dermatology.

    PubMed

    Almeida, Lívia Maria Martins de; Souza, Eliane Alves de Freitas; Bianchin, Débora Bertoluzzi; Svidzinski, Terezinha Inez Estivalet

    2009-07-01

    The high frequency of cutaneous mycosis justify the need to evaluate the possible contribution of in vitro profile of susceptibility to antifungal agents. To evaluate whether there is variability in in vitro susceptibility by filamentous fungi, previously isolated from cutaneous mycosis, to fluconazole, ketoconazole, itraconazole and terbinafine. Fungi were isolated and identified by classical methods and the antifungal susceptibility test was performed using the method of broth microdilution, according to a protocol recommended by the Clinical Laboratory Standards Institute (CLSI), through M38-A document. Amongst the 80 filamentous fungi identified, Trichophyton genus represented 81%. The four examined drugs showed great variation for Trichophyton spp and Microsporum spp. Fusarium spp was resistant to all tested drugs. Terbinafine was the most effective drug against the majority of the isolated fungi. There was great variability in response profiles to the tested antifungals. The definition of a reference test method will offer higher objectivity for physicians to choose the appropriate therapy.

  16. Ketoconazole, an antifungal agent, protects against adiposity induced by a cafeteria diet.

    PubMed

    Campión, J; Martínez, J A

    2004-07-01

    Ketoconazole, an anti-glucocorticoid agent, is widely used in humans as an antifungal agent. It inhibits ergosterol synthesis and reduces cortisol levels in the treatment of Cushing's Syndrome. The aim of this work was to study the drug's preventive potential against adiposity induced by a high-fat cafeteria diet in rats. Female Wistar rats were fed on standard pelleted diet or cafeteria diet during 42 days in the presence or absence of an oral treatment with ketoconazole (24 mg/kg of body weight). The cafeteria diet increased energy intake and body weight. In addition, this high-fat diet increased body-fat weight and adipose tissue depots analyzed. Interestingly, ketoconazole was able to protect against increased total body fat and adipose depot enlargement induced after cafeteria-diet feeding. Moreover, ex vivo isoproterenol-induced lipolysis was reduced in adipocytes from cafeteria-fed animals; this decrease was reverted by treatment with ketoconazole. Thus, ketoconazole was able to protect against adiposity induced by a cafeteria diet, revealing an interaction between fat intake and glucocorticoids on adipose deposition.

  17. Dynamics of in vitro acquisition of resistance by Candida parapsilosis to different azoles.

    PubMed

    Pinto e Silva, Ana Teresa; Costa-de-Oliveira, Sofia; Silva-Dias, Ana; Pina-Vaz, Cidália; Rodrigues, Acácio Gonçalves

    2009-06-01

    Candida parapsilosis is a common isolate from clinical fungal infectious episodes. Resistance of C. parapsilosis to azoles has been increasingly reported. To analyse the development of resistance in C. parapsilosis, four azole-susceptible clinical strains and one American Type Culture Collection type strain were cultured in the presence of fluconazole, voriconazole and posaconazole at different concentrations. The isolates developed variable degrees of azole resistance according to the antifungal used. Fluconazole was the fastest inducer while posaconazole was the slowest. Fluconazole and voriconazole induced resistance to themselves and each other, but not to posaconazole. Posaconazole induced resistance to all azoles. Developed resistance was stable; it could be confirmed after 30 days of subculture in drug-free medium. Azole-resistant isolates revealed a homogeneous population structure; the role of azole transporter efflux pumps was minor after evaluation by microdilution and cytometric assays with efflux pump blockers (verapamil, ibuprofen and carbonyl cyanide 3-chloro-phenylhydrazone). We conclude that the rapid development of azole resistance occurs by a mechanism that might involve mutation of genes responsible for ergosterol biosynthesis pathway, stressed by exposure to antifungals.

  18. 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.

  19. Low molecular weight chitosan is an effective antifungal agent against Botryosphaeria sp. and preservative agent for pear (Pyrus) fruits.

    PubMed

    Wang, Yunguang; Li, Bin; Zhang, Xuedan; Peng, Nan; Mei, Yuxia; Liang, Yunxiang

    2017-02-01

    Antifungal activity and preservative effect of a low molecular weight chitosan (LMWC) sample, derived from chitosan by enzymatic hydrolysis, were investigated in vitro and in vivo. A pathogenic fungal strain was isolated from decayed pear (Pyrus bretschneideri cv. "Huangguan") fruit and identified as Botryosphaeria sp. W-01. LMWC was shown to strongly inhibit W-01 growth based on studies of minimum inhibitory concentration (MIC) and effects on mycelial biomass and radial growth of the fungus. LMWC treatment of W-01 cells reduced ergosterol synthesis and mitochondrial membrane potential (ΔY), early events of apoptosis. Transmission electron microscopy and confocal laser scanning microscopy studies revealed that LMWC penetrated inside W-01 hyphae, thereby inducing ultrastructural damage. LMWC coating had a significant preservative effect on wounded and nonwounded pear fruits, by inhibiting postharvest decay and browning processes. LMWC activated several defense-related enzymes (polyphenol oxidase, peroxidase, chitinase), maintained nutritional value, and slowed down weight loss. Our findings indicate the strong potential of LMWC as a natural preservative agent for fruits and vegetables.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  1. Lipidomics and in Vitro Azole Resistance in Candida albicans

    PubMed Central

    Singh, Ashutosh; Mahto, Kaushal Kumar

    2013-01-01

    Abstract We have shown earlier that fluconazole (FLC) stress induces global changes in the lipidome of Candida albicans in clinically adapted isolates. However, several laboratories have developed adapted in vitro FLC resistant strains of C. albicans to study azole resistance mechanisms. This study aimed to identify the lipid changes associated with FLC resistance in these in vitro adapted isolates. Using comparative lipidomics and principal component and discriminant analyses, we observed gradual changes in several lipid classes and molecular species upon FLC exposure of in vitro resistant C. albicans strains. Although the lipid imprint of FLC in vitro resistant isolates was very distinct from that of clinical isolates of C. albicans, the overall changes in lipid class compositions were similar in both cases. For example, an increased sterol content and depleted sphingolipid levels were the salient features of FLC resistance in both conditions. Taken together, it appears that the overall cellular lipid homeostasis is a critical factor in the observed FLC resistance and in handling FLC stress in both clinical and laboratory situations. The new observations reported herein have implications for more efficacious antifungal drug development as well as understanding host–infectious agent interactions in postgenomics microbiology practice. PMID:23374108

  2. The use of SLN and NLC as topical particulate carriers for imidazole antifungal agents.

    PubMed

    Souto, E B; Müller, R H

    2006-05-01

    Two different imidazole antifungal agents have been used as model drugs to be incorporated into solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC), once they are very well established as anti-mycotics for the treatment of topical fungal infections. Because of the high mucoadhesive properties and the strong in situ gelling properties of polyacrylic acid polymers, hydrogels prepared with those macromolecules might be a promising vehicle for imidazole-loaded lipid nanoparticles, such as the above-mentioned SLN and NLC. Thus, in this study Carbopol 934 has been selected for the preparation of semi-solid formulations based on SLN and NLC. Formulations have been stored at three different temperatures before and after particle incorporation into polyacrylate hydrogels. The particle size and the chemical stability of incorporated model drugs have been monitored by HPLC analysis for two years. On the day of production 91.7% and 98.7% of clotrimazole, but only 62.1% and 70.3% of ketoconazole have been recovered from SLN and NLC, respectively. More than 95% of clotrimazole but less than 30% of ketoconazole were detected in the developed formulations after a shelf life of two years. Those values showed to be higher than those obtained with reference emulsions of similar composition and droplet sizes. By rheological measurements a pseudoplastic behaviour with thixotropic properties has been characterized for all semi-solid systems.

  3. 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.

  4. Effect of Growth Rate on Resistance of Candida albicans Biofilms to Antifungal Agents

    PubMed Central

    Baillie, George S.; Douglas, L. Julia

    1998-01-01

    A perfused biofilm fermentor, which allows growth-rate control of adherent microbial populations, was used to assess whether the susceptibility of Candida albicans biofilms to antifungal agents is dependent on growth rate. Biofilms were generated under conditions of glucose limitation and were perfused with drugs at a high concentration (20 times the MIC). Amphotericin B produced a greater reduction in the number of daughter cells in biofilm eluates than ketoconazole, fluconazole, or flucytosine. Similar decreases in daughter cell counts were observed when biofilms growing at three different rates were perfused with amphotericin B. In a separate series of experiments, intact biofilms, resuspended biofilm cells, and newly formed daughter cells were removed from the fermentor and were exposed to a lower concentration of amphotericin B for 1 h. The susceptibility profiles over a range of growth rates were then compared with those obtained for planktonic cells grown at the same rates under glucose limitation in a chemostat. Intact biofilms were resistant to amphotericin B at all growth rates tested, whereas planktonic cells were resistant only at low growth rates (≤0.13 h−1). Cells resuspended from biofilms were less resistant than intact biofilm populations but more resistant than daughter cells; the susceptibilities of both these cell types were largely independent of growth rate. Our findings indicate that the amphotericin B resistance of C. albicans biofilms is not simply due to a low growth rate but depends on some other feature of the biofilm mode of growth. PMID:9687381

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

    PubMed Central

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

    2015-01-01

    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

  6. Intra-antral application of an anti-fungal agent for recurrent maxillary fungal rhinosinusitis: a case report

    PubMed Central

    2012-01-01

    Introduction Fungal infection of the paranasal sinuses is an increasingly recognized entity both in immunocompetent and immunocompromised individuals. Treatment has been via use of either surgical or medical modalities, or a combination of the two. Here, we present a case of utilization of intra-antral application of an anti-fungal agent in the management of recurrent fungal sinusitis in an indigent Nigerian patient. Case presentation We present the case of a 30-year-old West African Yoruba man, an indigent Nigerian clergyman, who presented to our facility with a history of recurrent nasal discharge (about one year), recurrent nasal blockage (about five months), and right facial swelling (about one week). After intra-nasal antrostomy for debulking with a systemic anti-fungal agent, our patient had a recurrence after four months. Our patient subsequently had an intra-antral application of flumetasone and clioquinol (Locacorten®-Vioform®) weekly for six weeks with improvement of symptoms and no recurrence after six months of follow-up. Conclusions We conclude that topical intra-antral application of anti-fungal agents is effective in patients with recurrent fungal maxillary sinusitis after surgical debulking. PMID:22905703

  7. Azole fungicides disturb intracellular Ca2+ in an additive manner in dopaminergic PC12 cells.

    PubMed

    Heusinkveld, Harm J; Molendijk, Jeffrey; van den Berg, Martin; Westerink, Remco H S

    2013-08-01

    Humans are exposed to complex mixtures of pesticides and other compounds, mainly via food. Azole fungicides are broad spectrum antifungal compounds used in agriculture and in human and veterinary medicine. The mechanism of antifungal action relies on inhibition of CYP51, resulting in inhibition of fungal cell growth. Known adverse health effects of azole fungicides are mainly linked to CYP inhibition. Additionally, azole fungicide-induced neurotoxicity has been reported, though the underlying mechanism(s) are largely unknown. We therefore investigated the effects of a group of six azole fungicides (imazalil, flusilazole, fluconazole, tebuconazole, triadimefon, and cyproconazole) on cell viability using a combined alamar Blue/CFDA-AM assay and on oxidative stress using a H2-DCFDA fluorescent assay. As calcium plays a pivotal role in neuronal survival and functioning, effects of these six azole fungicides and binary and quaternary mixtures of azole fungicides on the intracellular calcium concentration ([Ca(2+)]i) were investigated using single-cell fluorescence microscopy in dopaminergic PC12 cells loaded with the calcium-sensitive fluorescent dye Fura-2. Only modest changes in cell viability and ROS production were observed. However, five out of six azole fungicides induced a nonspecific inhibition of voltage-gated calcium channels (VGCCs), though with varying potency. Experiments using binary IC20 and quaternary IC10 mixtures indicated that the inhibitory effects on VGCCs are additive. The combined findings demonstrate modulation of intracellular Ca(2+) via inhibition of VGCCs as a novel mode of action of azole fungicides. Furthermore, mixtures of azole fungicides display additivity, illustrating the need to take mixture effects into account in human risk assessment.

  8. Effects of temperature on anti-Candida activities of antifungal antibiotics.

    PubMed Central

    Odds, F C

    1993-01-01

    The relative growth (percentage of growth relative to control growth) of 767 Candida isolates representing five species was measured in microcultures at 25 and 37 degrees C. In the presence of 10(-4) M flucytosine, the distribution of relative yeast growth data indicated that Candida albicans isolates were less susceptible at 25 degrees C than at 37 degrees C, while the opposite was found with 4 x 10(-5) M amorolfine for most of the isolates tested. Repetition of the experiments at four different temperatures with 99 C. albicans isolates and five antifungal agents confirmed a direct relationship between growth inhibition and increasing temperature from 25 to 40 degrees C with amphotericin B, flucytosine, and terconazole; a strong inverse relationship between inhibition and temperature with amorolfine; and a weak inverse relationship with terbinafine. However, these relationships were not always noted with other Candida spp.: in particular, the growth of C. glabrata and C. parapsilosis isolates tended to be greater at 37 degrees C than at 25 degrees C in the presence of the azole-derivative antifungal agents itraconazole and terconazole. These findings stress the species-specific individuality of yeast susceptibility to azole antifungal agents. The results with C. albicans and amorolfine and terbinafine accord with their known in vivo efficacy in mycoses involving low-temperature superficial sites and poor activity against mycoses involving deep body sites. The data also reinforce the need for control of experimental variables such as temperature in the design of standardized yeast susceptibility tests. PMID:8494363

  9. Effects of temperature on anti-Candida activities of antifungal antibiotics.

    PubMed

    Odds, F C

    1993-04-01

    The relative growth (percentage of growth relative to control growth) of 767 Candida isolates representing five species was measured in microcultures at 25 and 37 degrees C. In the presence of 10(-4) M flucytosine, the distribution of relative yeast growth data indicated that Candida albicans isolates were less susceptible at 25 degrees C than at 37 degrees C, while the opposite was found with 4 x 10(-5) M amorolfine for most of the isolates tested. Repetition of the experiments at four different temperatures with 99 C. albicans isolates and five antifungal agents confirmed a direct relationship between growth inhibition and increasing temperature from 25 to 40 degrees C with amphotericin B, flucytosine, and terconazole; a strong inverse relationship between inhibition and temperature with amorolfine; and a weak inverse relationship with terbinafine. However, these relationships were not always noted with other Candida spp.: in particular, the growth of C. glabrata and C. parapsilosis isolates tended to be greater at 37 degrees C than at 25 degrees C in the presence of the azole-derivative antifungal agents itraconazole and terconazole. These findings stress the species-specific individuality of yeast susceptibility to azole antifungal agents. The results with C. albicans and amorolfine and terbinafine accord with their known in vivo efficacy in mycoses involving low-temperature superficial sites and poor activity against mycoses involving deep body sites. The data also reinforce the need for control of experimental variables such as temperature in the design of standardized yeast susceptibility tests.

  10. Possible role of azole and echinocandin lock solutions in the control of Candida biofilms associated with silicone.

    PubMed

    Cateau, Estelle; Berjeaud, Jean-Marc; Imbert, Christine

    2011-04-01

    Until now, management of candidiasis related to implanted devices has remained problematic. The aim of this study was to investigate antifungal lock strategies against Candida albicans and Candida glabrata biofilms in vitro. Three antifungal agents were used against eight C. albicans and six C. glabrata clinical strains isolated from infected catheters. Caspofungin and micafungin, both echinocandins, as well as the azole posaconazole were tested. An in vitro model of Candida biofilm on 100% silicone catheters was used. Efficacy of the antifungal lock was tested against biofilms aged 12h and 5 days following exposure to caspofungin (5mg/L and 25mg/L), micafungin (5mg/L and 15 mg/L) and posaconazole (10mg/L) for 12h. Persistence of antibiofilm activity was investigated 1-3 days following drug elimination. Antifungal lock was considered effective in the event of a significant decrease (P<0.001) in the metabolic activity of the biofilm yeast. The results showed that micafungin had significant inhibitory effectiveness against young and mature C. albicans and C. glabrata biofilms. Moreover, this activity appeared to persist for up to 3 days. Caspofungin displayed similar activity against all C. albicans biofilms, but the activity was less persistent for C. glabrata biofilms. Posaconazole was less effective against C. albicans biofilms, but its activity was sustained. Echinocandin lock therapy could significantly enhance the management of candidiasis in patients with indwelling catheters by combating biofilms and enabling device maintenance in situ.

  11. Cunninghamella bertholletiae exhibits increased resistance to human neutrophils with or without antifungal agents as compared to Rhizopus spp.

    PubMed

    Simitsopoulou, Maria; Georgiadou, Elpiniki; Walsh, Thomas J; Roilides, Emmanuel

    2010-08-01

    Among Zygomycetes, Cunninghamella bertholletiae occurs less frequently as the etiologic agent of human disease but causes more aggressive, refractory, and fatal infections despite antifungal therapy. Little is known about the differential innate host response against Cunninghamella and other Zygomycetes in the presence of antifungal agents. We therefore studied the activity of human neutrophils (PMNs) alone or in combination with caspofungin, posaconazole (PSC), and voriconazole (VRC) against hyphae of Rhizopus oryzae, Rhizopus microsporus and C. bertholletiae. Hyphal damage was measured by XTT metabolic assay and release of IL-6, IL-8 and TNF-alpha from PMNs by ELISA. Cunninghamella bertholletiae was more resistant to PMN-induced hyphal damage than either Rhizopus spp. at effector:target (E:T) ratios of 1:1, 5:1 and 10:1 (P < 0.05). The hyphal damage caused by caspofungin at 0.1 microg/ml or PSC and VRC at 0.5 microg/ml with C. bertholletiae and R. oryzae and by caspofungin against R. microsporus ranged from 18-29%. The PMN-induced hyphal damage was not modulated by combination with antifungal agents. Cunninghamella bertholletiae induced significantly decreased IL-8 (P < 0.05), but increased TNF-alpha release from PMNs compared to both Rhizopus spp. (P < 0.01). No IL-6 was released from PMNs exposed to the three Zygomycetes. In comparison to R. oryzae and R. microsporus, C. bertholletiae is more resistant to PMN-induced hyphal damage with or without antifungal therapy and is more capable of suppressing release of IL-8.

  12. Oxygenated monoterpenes-rich volatile oils as potential antifungal agents for dermatophytes.

    PubMed

    Dias, N; Dias, M C; Cavaleiro, C; Sousa, M C; Lima, N; Machado, M

    2017-02-01

    Essential oils (EOs) extracted from Lavandula luisieri and Cymbopogon citratus were tested for their antifungal activity against ten clinical isolates of dermatophytes isolated from cases of tinea pedis. Inhibition of conidial germination and antifungal drug/EO combination assay were tested on two ATCC reference strains of Trichophyton rubrum and Trichophyton mentagrophytes. EOs were characterised by high amount of oxygenated monoterpenes in their composition. Strong antifungal activity was observed for the majority of clinical strains, and fungicidal activity was demonstrated. Positive interaction between L. luisieri EO combined with terbinafine was observed against terbinafine-resistant strain (Tr ATCC MYA-4438). Significative reduction of the germination was observed above 100 μg mL(-1). Both oils were safe to macrophage mammalian cells at tested concentration. This study describes the antifungal activity of L. luisieri and C. citratus EOs against dermatophytes, which could be useful in designing new formulations for topical treatments.

  13. Imidazole clubbed 1,3,4-oxadiazole derivatives as potential antifungal agents.

    PubMed

    Wani, Mohmmad Younus; Ahmad, Aijaz; Shiekh, Rayees Ahmad; Al-Ghamdi, Khalaf J; Sobral, Abilio J F N

    2015-08-01

    A series of compounds in which 2-(4-ethyl-2-pyridyl)-1H-imidazole was clubbed with substituted 1,3,4-oxadiazole was synthesized and subjected to antifungal activity evaluation. In vitro assays indicated that several clubbed derivatives had excellent antifungal activity against different strains of laboratory and clinically isolated Candida species. Structural Activity Relationship (SAR) studies revealed that the presence and position of substituents on the phenyl ring of the 1,3,4-oxadiazole unit, guides the antifungal potential of the compounds, where compound 4b, 4c and 4g were found to be active against all the tested fungal strains. Impairment of ergosterol biosynthesis upon the concomitant treatment of 4b, 4c and 4g, revealed the possible mechanisms of antifungal action of these compounds. Inhibitors snugly fitting the active site of the target enzyme, as revealed by molecular docking studies, may well explain their excellent inhibitory activity.

  14. 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.

  15. Bioactivity and structure-activity relationship of cinnamic acid esters and their derivatives as potential antifungal agents for plant protection.

    PubMed

    Zhou, Kun; Chen, Dongdong; Li, Bin; Zhang, Bingyu; Miao, Fang; Zhou, Le

    2017-01-01

    A series of cinnamic acid esters and their derivatives were synthesized and evaluated for antifungal activities in vitro against four plant pathogenic fungi by using the mycelium growth rate method. Structure-activity relationship was derived also. Almost all of the compounds showed some inhibition activity on each of the fungi at 0.5 mM. Eight compounds showed the higher average activity with average EC50 values of 17.4-28.6 μg/mL for the fungi than kresoxim-methyl, a commercial fungicide standard, and ten compounds were much more active than commercial fungicide standards carbendazim against P. grisea or kresoxim-methyl against both P. grisea and Valsa mali. Compounds C1 and C2 showed the higher activity with average EC50 values of 17.4 and 18.5 μg/mL and great potential for development of new plant antifungal agents. The structure-activity relationship analysis showed that both the substitution pattern of the phenyl ring and the alkyl group in the alcohol moiety significantly influences the activity. There exists complexly comprehensive effect between the substituents on the phenyl ring and the alkyl group in the alcohol moiety on the activity. Thus, cinnamic acid esters showed great potential the development of new antifungal agents for plant protection due to high activity, natural compounds or natural compound framework, simple structure, easy preparation, low-cost and environmentally friendly.

  16. Bioactivity and structure-activity relationship of cinnamic acid esters and their derivatives as potential antifungal agents for plant protection

    PubMed Central

    Li, Bin; Zhang, Bingyu; Miao, Fang

    2017-01-01

    A series of cinnamic acid esters and their derivatives were synthesized and evaluated for antifungal activities in vitro against four plant pathogenic fungi by using the mycelium growth rate method. Structure−activity relationship was derived also. Almost all of the compounds showed some inhibition activity on each of the fungi at 0.5 mM. Eight compounds showed the higher average activity with average EC50 values of 17.4–28.6 μg/mL for the fungi than kresoxim-methyl, a commercial fungicide standard, and ten compounds were much more active than commercial fungicide standards carbendazim against P. grisea or kresoxim-methyl against both P. grisea and Valsa mali. Compounds C1 and C2 showed the higher activity with average EC50 values of 17.4 and 18.5 μg/mL and great potential for development of new plant antifungal agents. The structure−activity relationship analysis showed that both the substitution pattern of the phenyl ring and the alkyl group in the alcohol moiety significantly influences the activity. There exists complexly comprehensive effect between the substituents on the phenyl ring and the alkyl group in the alcohol moiety on the activity. Thus, cinnamic acid esters showed great potential the development of new antifungal agents for plant protection due to high activity, natural compounds or natural compound framework, simple structure, easy preparation, low-cost and environmentally friendly. PMID:28423022

  17. 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

  18. Synthesis and evaluation of α-Ag2WO4 as novel antifungal agent

    NASA Astrophysics Data System (ADS)

    Foggi, Camila C.; Fabbro, Maria T.; Santos, Luís P. S.; de Santana, Yuri V. B.; Vergani, Carlos E.; Machado, Ana L.; Cordoncillo, Eloisa; Andrés, Juan; Longo, Elson

    2017-04-01

    Because of the need for new antifungal materials with greater potency, microcrystals of α-Ag2WO4, a complex metal oxide, have been synthetized by a simple co-precipitation method, and their antifungal activity against Candida albicans has been investigated. A theoretical model based on clusters that are building blocks of α-Ag2WO4 has been proposed to explain the experimental results.

  19. Synthesis and screening of antibacterial and antifungal activity of 5-chloro-1,3-benzoxazol-2(3 h)-one derivatives

    PubMed Central

    2012-01-01

    Background An antibacterial is a substance that either kills bacteria or slows their growth. Antifungal are the agents that use drugs for treatment of fungal infections. 5-Chloro-1,3-benzoxazol-2(3 H)-one (5-Chloro Benzoxazolinone) contains an azole ring structure. Numbers of azole compounds are reported as antibacterial and antifungal agents. Benzoxazolinones naturally occur in plants. They play a role as defense compounds against bacteria, fungi, and insects. Results In this article, synthesis of six Benzoxazolinone derivatives with various substituents is presented. Benzoxazolinone substituted with p-aminobenzoic acids and sulphanilamide derivatives. The above both substituents are reported as potent antimicrobial agents. Attachment with azole leads to increase its potency. The other substituents are 2,4-dichlorobezylchloride. The same rings are found in miconazole and this may lead to increase its antifungal activity. Fluconazole also contains triazole moiety and triazole is having other numbers of activity like antimicrobial, anti-inflammatory, local anesthetic, antiviral, anticancer, antimalarial, etc. Here, there is a substitution for azole ring at 5-Chloro position which might increase antibacterial and antifungal activity. The synthesis and interpretation of six final compounds and three intermediates are presented in this article. Synthesis of 5-Chloro Benzoxazolinone derivatives substituted with Halogenated rings, sulfonated and benzylated derivatives and azole derivatives. There is a synthesis of P2A, P2B, P4A, P4B, P5A, and P6A compounds and their structures were characterized by UV–Visible, IR, MASS spectroscopy, and NMR spectroscopy. Conclusions The antibacterial activity of all six compounds is measured against various Gram-positive and Gram-negative bacteria and against fungi. Compounds P4A and P4B have good antibacterial and antifungal activity, half of the Ampicillin and Cephalexin. P4A, P4B, P6A have good activity against Staphylococcus aureus

  20. Exopolysaccharide matrix of developed Candida albicans biofilms after exposure to antifungal agents.

    PubMed

    da Silva, Wander José; Gonçalves, Letícia Machado; Seneviratne, Jayampath; Parahitiyawa, Nipuna; Samaranayake, Lakshman Perera; Del Bel Cury, Altair Antoninha

    2012-01-01

    This study aimed to evaluate the effects of fluconazole or nystatin exposure on developed Candida albicans biofilms regarding their exopolysaccharide matrix. The minimal inhibitory concentration (MIC) against fluconazole or nystatin was determined for C. albicans reference strain (ATCC 90028). Poly(methlymethacrylate) resin (PMMA) specimens were fabricated according to the manufacturer's instructions and had their surface roughness measured. Biofilms were developed on specimens surfaces for 48 h and after that were exposed during 24 h to fluconazole or nystatin prepared in a medium at MIC, 10 x MIC or 100 x MIC. Metabolic activity was evaluated using an XTT assay. Production of soluble and insoluble exopolysaccharide and intracellular polysaccharides was evaluated by the phenol-sulfuric method. Confocal laser scanning microscope was used to evaluate biofilm architecture and percentage of dead/live cells. Data were analyzed statistically by ANOVA and Tukey's test at 5% significance level. The presence of fluconazole or nystatin at concentrations higher than MIC results in a great reduction of metabolic activity (p<0.001). At MIC or 10 x MIC, fluconazole showed high amounts of intracellular polysaccharides (p<0.05), but did not affect the exopolysaccharide matrix (p>0.05). The exposure to nystatin also did not alter the exopolysaccharide matrix at all the tested concentrations (p>0.05). Biofilm architecture was not affected by either of the antifungal agents (p>0.05). Nystatin promoted higher proportion of dead cells (p<0.05). It may be concluded that fluconazole and nystatin above the MIC concentration reduced the metabolic activity of C. albicans biofilms; however, they were not able to alter the exopolysaccharide matrix and biofilm architecture.

  1. 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

  2. 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.

  3. Azole resistance in Cryptococcus gattii from the Pacific Northwest: Investigation of the role of ERG11.

    PubMed

    Gast, Charles E; Basso, Luiz R; Bruzual, Igor; Wong, Brian

    2013-11-01

    Cryptococcus gattii is responsible for an expanding epidemic of serious infections in Western Canada and the Northwestern United States (Pacific Northwest). Some patients with these infections respond poorly to azole antifungals, and high azole MICs have been reported in Pacific Northwest C. gattii. In this study, multiple azoles (but not amphotericin B) had higher MICs for 25 Pacific Northwest C. gattii than for 34 non-Pacific Northwest C. gattii or 20 Cryptococcus neoformans strains. We therefore examined the roles in azole resistance of overexpression of or mutations in the gene (ERG11) encoding the azole target enzyme. ERG11/ACT1 mRNA ratios were higher in C. gattii than in C. neoformans, but these ratios did not differ in Pacific Northwest and non-Pacific Northwest C. gattii strains, nor did they correlate with fluconazole MICs within any group. Three Pacific Northwest C. gattii strains with low azole MICs and 2 with high azole MICs had deduced Erg11p sequences that differed at one or more positions from that of the fully sequenced Pacific Northwest C. gattii strain R265. However, the azole MICs for conditional Saccharomyces cerevisiae erg11 mutants expressing the 5 variant ERG11s were within 2-fold of the azole MICs for S. cerevisiae expressing the ERG11 gene from C. gattii R265, non-Pacific Northwest C. gattii strain WM276, or C. neoformans strains H99 or JEC21. We conclude that neither ERG11 overexpression nor variations in ERG11 coding sequences was responsible for the high azole MICs observed for the Pacific Northwest C. gattii strains we studied.

  4. 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

  5. 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).

  6. Antifungal Activity of Propolis Against Yeasts Isolated From Blood Culture: In Vitro Evaluation.

    PubMed

    Mutlu Sariguzel, Fatma; Berk, Elife; Koc, Ayes Nedret; Sav, Hafize; Demir, Gonca

    2016-09-01

    Due to the failure of available antifungal agents in the treatment of candidemia and the toxic activities of these drugs, a lot of researches are being conducted to develop new nontoxic and effective antifungal agents for optimal control of fungal pathogens. The aim of this study is to evaluate the in vitro antifungal activity of propolis against yeasts isolated from the blood cultures of intensive care unit patients. Seventy-six strains were included in this study. The in vitro antifungal activity of propolis, fluconazole (FLU), and itraconazole (ITR) was investigated by the microdilution broth methods (CLSI guidelines M27-A3 for yeast). The propolis sample was collected from Kayseri, Turkey. Of the 76 isolates, 33 were identified as Candida albicans while 37 were C. parapsilosis, three were C. tropicalis, and three were identified as C. glabrata. The geometric mean range for MIC (μg/ml) with regard to all isolates was 0.077 to 3 μg/ml for FLU and ITR, and 0.375 to 0.70 μg/ml for propolis. It was shown that propolis had significant antifungal activity against all Candida strains and the MIC range of propolis was determined as 0185 to 3 μg/ml. This study demonstrated that propolis had significant antifungal activity against yeasts isolated from blood culture compared with FLU and ITR. The propolis MIC in azole-resistant strains such as C. glabrata was found lower than the FLU MIC. © 2015 Wiley Periodicals, Inc.

  7. Antifungal combinations.

    PubMed

    Vitale, Roxana G; Afeltra, Javier; Dannaoui, Eric

    2005-01-01

    The increase in fungal infections and the change in fungal epidemiology is caused by the extensive use of antifungal agents to treat fungal infections that are being diagnosed in severly immunocompromised hosts. In addition, opportunistic fungal infections resistant to antifungal drugs have become increasingly common, and the armamentarium for treatment remains limited. A possible approach to overcoming these problems is to combine antifungal drugs, especially if the mechanisms of action are different. The in vitro test is the first step to evaluate possible antifungal combinations. In this chapter, the three most frequently used metholodologies are described: checkerboard, E-test, and time-kill curves. The description of each technique and intrepretaion of the results are addressed in detail.

  8. 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.

  9. Antifungal testing and high-throughput screening of compound library against Geomyces destructans, the etiologic agent of geomycosis (WNS) in bats.

    PubMed

    Chaturvedi, Sudha; Rajkumar, Sunanda S; Li, Xiaojiang; Hurteau, Gregory J; Shtutman, Michael; Chaturvedi, Vishnu

    2011-03-02

    Bats in the northeastern U.S. are affected by geomycosis caused by the fungus Geomyces destructans (Gd). This infection is commonly referred to as White Nose Syndrome (WNS). Over a million hibernating bats have died since the fungus was first discovered in 2006 in a cave near Albany, New York. A population viability analysis conducted on little brown bats (Myotis lucifugus), one of six bat species infected with Gd, suggests regional extinction of this species within 20 years. The fungus Gd is a psychrophile ("cold loving"), but nothing is known about how it thrives at low temperatures and what pathogenic attributes allow it to infect bats. This study aimed to determine if currently available antifungal drugs and biocides are effective against Gd. We tested five Gd strains for their susceptibility to antifungal drugs and high-throughput screened (HTS) one representative strain with SpectrumPlus compound library containing 1,920 compounds. The results indicated that Gd is susceptible to a number of antifungal drugs at concentrations similar to the susceptibility range of human pathogenic fungi. Strains of Gd were susceptible to amphotericin B, fluconazole, itraconazole, ketoconazole and voriconazole. In contrast, very high MICs (minimum inhibitory concentrations) of flucytosine and echinocandins were needed for growth inhibition, which were suggestive of fungal resistance to these drugs. Of the 1,920 compounds in the library, a few caused 50%--to greater than 90% inhibition of Gd growth. A number of azole antifungals, a fungicide, and some biocides caused prominent growth inhibition. Our results could provide a theoretical basis for future strategies aimed at the rehabilitation of most affected bat species and for decontamination of Gd in the cave environment.

  10. In vitro activity of the protegrin IB-367 alone and in combination compared with conventional antifungal agents against dermatophytes.

    PubMed

    Simonetti, Oriana; Silvestri, Carmela; Arzeni, Daniela; Cirioni, Oscar; Kamysz, Wojciech; Conte, Irene; Staffolani, Silvia; Orsetti, Elena; Morciano, Angela; Castelli, Pamela; Scalise, Alessandro; Kamysz, Elzbieta; Offidani, Anna Maria; Giacometti, Andrea; Barchiesi, Francesco

    2014-04-01

    The occurrence of resistance or side effects in patients receiving antifungal agents leads to failure in the treatment of mycosis. The aim of this experimental study was to investigate the in vitro effects of IB-367 alone and in combination with three standard antifungal drugs, fluconazole (FLU), itraconazole (ITRA) and terbinafine (TERB), against 20 clinical isolates of dermatophytes belonging to three species. Minimum inhibitory concentrations (MICs), minimal fungicidal concentrations (MFCs), synergy test, time-kill curves, fungal biomass (FB) and hyphal damage using 2,3-bis-(2-methoxy-4-nitro-5-sulfenylamino carbonil)-2H-tetrazolium hydroxide assay (XTT) were performed to study the efficacy of IB-367. In this study, we observed that TERB and ITRA had MICs lower values for all the strains compared to IB-367 and FLU. Synergy was found in 35%, 30% and 25% of IB-367/FLU, IB-367/ITRA and IB-367/TERB interactions respectively. IB-367 exerted a fungicidal activity against Trichophyton mentagrophytes, T. rubrum and Microsporum canis at concentrations starting from 1x MIC. At a concentration of 5x MIC, IB-367 showed the highest rates of hyphae damage for M. canis 53% and T. mentagrophytes 50%; against the same isolates it caused a reduction of 1 log of the total viable count cell hyphae damage. We propose IB-367 as a promising candidate for the future design of antifungal drugs.

  11. 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.

  12. [Antifungal agents in dermatophytic disease: failure of griseofulvin, ketoconazole and itraconazole].

    PubMed

    Boudghène-Stambouli, O; Mérad-Boudia, A

    1990-01-01

    The dermatophytic disease is a rare, severe affection caused by banal dermatophytes. A genetically predisposed basis could explain the frequent failure of antifungal therapeutics. We report here the case of a 28-year-old male. Despite 2 years of griseofulvin, 23 months of ketoconazole and 8 months of itraconazole, the therapeutic failure was evident: circinate herpes, papulo-nodules, vegetating plaques, ulceration, superficial and profound adenopathies, cerebral involvement, and deterioration of the general state. The correction of the immuno-deficient state combined with antifungals could be the best therapy.

  13. 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.

  14. Antifungal Therapy in Hematopoietic Stem Cell Transplant Recipients

    PubMed Central

    Busca, Alessandro; Pagano, Livio

    2016-01-01

    Invasive fungal infections (IFI) represent a major hindrance to the success of hematopoietic stem cell transplantation (HSCT), contributing substantially to morbidity and infection-related mortality. During the most recent years several reports indicate an overall increase of IFI among hematologic patients, in particular, invasive aspergillosis, that may be explained, at least partially, by the fact that diagnoses only suspected in the past, are now more easily established due to the application of serum biomarkers and early use of CT scan. Along with new diagnostic options, comes the recent development of novel antifungal agents that expanded the spectrum of activity over traditional treatments contributing to the successful management of fungal diseases. When introduced in 1959, Amphotericin B deoxycholate (d-AmB) was a life-saving drug, and the clinical experience over 50 years has proven that this compound is effective although toxic. Given the superior safety profile, lipid formulations of AmB have now replaced d-AmB in many circumstances. Similarly, echinocandins have been investigated as initial therapy for IA in several clinical trials including HSCT recipients, although the results were moderately disappointing leading to a lower grade of recommendation in the majority of published guidelines. Azoles represent the backbone of therapy for treating immunocompromised patients with IFI, including voriconazole and the newcomer isavuconazole; in addition, large studies support the use of mold-active azoles, namely voriconazole and posaconazole, as antifungal prophylaxis in HSCT recipients. The aim of the present review is to summarize the clinical application of antifungal agents most commonly employed in the treatment of IFI. PMID:27648202

  15. Antifungal Therapy in Hematopoietic Stem Cell Transplant Recipients.

    PubMed

    Busca, Alessandro; Pagano, Livio

    2016-01-01

    Invasive fungal infections (IFI) represent a major hindrance to the success of hematopoietic stem cell transplantation (HSCT), contributing substantially to morbidity and infection-related mortality. During the most recent years several reports indicate an overall increase of IFI among hematologic patients, in particular, invasive aspergillosis, that may be explained, at least partially, by the fact that diagnoses only suspected in the past, are now more easily established due to the application of serum biomarkers and early use of CT scan. Along with new diagnostic options, comes the recent development of novel antifungal agents that expanded the spectrum of activity over traditional treatments contributing to the successful management of fungal diseases. When introduced in 1959, Amphotericin B deoxycholate (d-AmB) was a life-saving drug, and the clinical experience over 50 years has proven that this compound is effective although toxic. Given the superior safety profile, lipid formulations of AmB have now replaced d-AmB in many circumstances. Similarly, echinocandins have been investigated as initial therapy for IA in several clinical trials including HSCT recipients, although the results were moderately disappointing leading to a lower grade of recommendation in the majority of published guidelines. Azoles represent the backbone of therapy for treating immunocompromised patients with IFI, including voriconazole and the newcomer isavuconazole; in addition, large studies support the use of mold-active azoles, namely voriconazole and posaconazole, as antifungal prophylaxis in HSCT recipients. The aim of the present review is to summarize the clinical application of antifungal agents most commonly employed in the treatment of IFI.

  16. A D-octapeptide drug efflux pump inhibitor acts synergistically with azoles in a murine oral candidiasis infection model.

    PubMed

    Hayama, Kazumi; Ishibashi, Hiroko; Ishijima, Sanae A; Niimi, Kyoko; Tansho, Shigeru; Ono, Yasuo; Monk, Brian C; Holmes, Ann R; Harding, David R K; Cannon, Richard D; Abe, Shigeru

    2012-03-01

    Clinical management of patients undergoing treatment of oropharyngeal candidiasis with azole antifungals can be impaired by azole resistance. High-level azole resistance is often caused by the overexpression of Candida albicans efflux pump Cdr1p. Inhibition of this pump therefore represents a target for combination therapies that reverse azole resistance. We assessed the therapeutic potential of the D-octapeptide derivative RC21v3, a Cdr1p inhibitor, in the treatment of murine oral candidiasis caused by either the azole-resistant C. albicans clinical isolate MML611 or its azole-susceptible parental strain MML610. RC21v3, fluconazole (FLC), or a combination of both drugs were administered orally to immunosuppressed ICR mice at 3, 24, and 27 h after oral inoculation with C. albicans. FLC protected the mice inoculated with MML610 from oral candidiasis, but was only partially effective in MML611-infected mice. The co-application of RC21v3 (0.02 μmol per dose) potentiated the therapeutic performance of FLC for mice infected with either strain. It caused a statistically significant decrease in C. albicans cfu isolated from the oral cavity of the infected mice and reduced oral lesions. RC21v3 also enhanced the therapeutic activity of itraconazole against MML611 infection. These results indicate that RC21v3 in combination with azoles has potential as a therapy against azole-resistant oral candidiasis.

  17. 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

  18. Fungal CYP51 Inhibitors VT-1161 and VT-1129 Exhibit Strong In Vitro Activity against Candida glabrata and C. krusei Isolates Clinically Resistant to Azole and Echinocandin Antifungal Compounds.

    PubMed

    Schell, W A; Jones, A M; Garvey, E P; Hoekstra, W J; Schotzinger, R J; Alexander, B D

    2017-03-01

    The in vitro activities of fungal CYP51 inhibitors VT-1161 and VT-1129 were determined for Candida glabrata (n = 34) and C. krusei (n = 50). C. glabrata isolates were screened for FKS gene mutations. All isolates were resistant clinically and/or in vitro to at least one standard antifungal compound. VT-1161 and VT-1129 MICs for all isolates were at least 5-fold below achievable human plasma levels for VT-1161. VT-1161 and VT-1129 are promising for the treatment of resistant C. glabrata and C. krusei infections. Copyright © 2017 American Society for Microbiology.

  19. Ototopical antifungals and otomycosis: a review.

    PubMed

    Munguia, Raymundo; Daniel, Sam J

    2008-04-01

    There has been an increase in the prevalence of otomycosis in recent years. This has been linked to the extensive use of antibiotic eardrops. Treatment of otomycosis is challenging, and requires a close follow-up. We present a review of the literature on otomycosis, the topical antifungals most commonly used, and discuss their ototoxic potential. Candida albicans and Aspergillus are the most commonly identified organisms. Antifungals from the Azole class seem to be the most effective, followed by Nystatin and Tolnaftate.

  20. Inhibition of heat-shock protein 90 enhances the susceptibility to antifungals and reduces the virulence of Cryptococcus neoformans/Cryptococcus gattii species complex.

    PubMed

    Cordeiro, Rossana de Aguiar; Evangelista, Antonio José de Jesus; Serpa, Rosana; Marques, Francisca Jakelyne de Farias; de Melo, Charlline Vládia Silva; de Oliveira, Jonathas Sales; Franco, Jônatas da Silva; de Alencar, Lucas Pereira; Bandeira, Tereza de Jesus Pinheiro Gomes; Brilhante, Raimunda Sâmia Nogueira; Sidrim, José Júlio Costa; Rocha, Marcos Fébio Gadelha

    2016-02-01

    Heat-shock proteins (Hsps) are chaperones required for the maintenance of cellular homeostasis in different fungal pathogens, playing an important role in the infectious process. This study investigated the effect of pharmacological inhibition of Hsp90 by radicicol on the Cryptococcus neoformans/Cryptococcus gattii species complex--agents of the most common life-threatening fungal infection amongst immunocompromised patients. The influence of Hsp90 inhibition was investigated regarding in vitro susceptibility to antifungal agents of planktonic and sessile cells, ergosterol concentration, cell membrane integrity, growth at 37 °C, production of virulence factors in vitro, and experimental infection in Caenorhabditis elegans. Hsp90 inhibition inhibited the in vitro growth of planktonic cells of Cryptococcus spp. at concentrations ranging from 0.5 to 2 μg ml(-1) and increased the in vitro inhibitory effect of azoles, especially fluconazole (FLC) (P < 0.05). Inhibition of Hsp90 also increased the antifungal activity of azoles against biofilm formation and mature biofilms of Cryptococcus spp., notably for Cryptococcus gattii. Furthermore, Hsp90 inhibition compromised the permeability of the cell membrane, and reduced planktonic growth at 37 °C and the capsular size of Cryptococcus spp. In addition, Hsp90 inhibition enhanced the antifungal activity of FLC during experimental infection using Caenorhabditis elegans. Therefore, our results indicate that Hsp90 inhibition can be an important strategy in the development of new antifungal drugs.

  1. Interactive effects of antifungal and antineoplastic agents on yeasts commonly prevalent in cancer patients.

    PubMed Central

    Ghannoum, M A; Motawy, M S; Abu Hatab, M A; Abu Elteen, K H; Criddle, R S

    1989-01-01

    The effects of combinations of antifungal and antineoplastic drugs on inhibition of the growth of yeasts which commonly infect cancer patients have been analyzed. It was shown that (i) inhibitory drug combinations could be selected in which all drugs were at levels far below their individual MICs; (ii) interactive effects among antineoplastic and antifungal drugs may be very large; (iii) optimum combinations of drugs for inhibition of yeast growth depended upon both the relative and absolute concentrations of the drugs in the mixture; (iv) drug combinations which were effective at low levels in inhibiting one test yeast were also generally effective against other species, but the levels of susceptibilities and, to a lesser extent, the best ratios of drugs in the test combinations varied with species; and (v) to quantitatively evaluate drug interactions, it is necessary to carefully define and control all experimental conditions, absolute and relative concentrations of drugs used, and the organisms tested. PMID:2751285

  2. New synthesis and biological evaluation of benzothiazole derivates as antifungal agents.

    PubMed

    Herrera Cano, Natividad; Ballari, María S; López, Abel G; Santiago, Ana N

    2015-04-15

    In search of new antifungal agrochemicals that could replace commercially available, aryl-2-mercaptobenzothiazoles were synthesized. They were prepared by two methodologies, using both photostimulated reaction and microwave assisted reaction. These reactions took place without the use of metallic catalyst by a one-pot procedure with excellent yields (70-98%). Synthesized compounds were evaluated for fungal growth inhibition against Botrytis cinerea. Most of the compounds have an excellent antifungal activity, and three of these showed a superior inhibitory effect to commercial fungicide Triadimefon. IC50 values observed for 2-(phenylthio)benzothiazole, 2-(2-chlorophenylthio)benzothiazole, and 2-(3-chlorophenyl thio)benzothiazole were 0.75, 0.69, and 0.65 μg mL(-1), respectively.

  3. Chemoenzymatic synthesis of two new halogenated coumarin glycosides as potential antifungal agents.

    PubMed

    Zhou, Liangbin; Liu, Ling; Tian, Tian; Xue, Bailin; Yu, Rongmin

    2012-10-01

    Two new potential antifungal coumarin glycosides, 6-chlorocoumarin 7-O-beta-D-glucopyranoside (1) and 7-hydroxy-4-trifluoromethyl-coumarin 5-O-beta-D-glucopyranoside (2), were synthesized via enzyme-mediated glycosylation of the respective aglycone, 6-chloro-7-hydroxycoumarin and 5,7-dihydroxy-4-trifluoromethylcoumarin, using transgenic hairy roots of Polygonum multiflorum. Instead of application of the isolated enzyme and exogenous sugar donors, hairy roots of P. multiflorum were successfully adapted as a whole-cell biocatalyst.

  4. Combination of synthetic and natural products as pesticides (CSYNAP): a new class of antifungal agents.

    PubMed

    Rani, Archna; Jain, Sapna; Dureja, Prem; Tripathi, Praveen K; Singh, Kamalendra

    In the present communication some dehydrated dialdol products such as 1, 5 - Diphenyl pent - 1, 4 - diene - 3 - one (A1); 1, 9 - Diphenylnon - 1, 3, 6, 8 - tetraene - 5 - one (A2); 1, 5 - di (2 - hydroxyphenyl) pent - 1, 4 - diene - 3 - one (A3); 1, 5 - difuran pent - 1, 4 - diene - 3 - one (A4); 1, 5 - di [4 - bis (N, Ndimethyl) phenyl] pent - 1, 4 - diene - 3 - one (A5) were screened for their antifungal activity. To reduce their adverse effect on the environment, for the first time, we have attempted to screen the antifungal activity of these synthetic compounds in conjunction with selected natural products. The natural products that were used in our study include Nicotine tobaccum and Neem oil (Azadirachta indica). A set of 15 samples was tested against highly pathogenic and of extensive host range fungi Sclerotium rolfsii, Rhizactonia bataticola, Fusarium udum. The filter paper disc assay to monitor antifungal effect revealed significant and interesting results. We found that the use of the combination of natural and synthetic pesticides is more effective and environmentally healthy compared to just synthetic chemicals and/or less available natural products. These results obtained from the combined use of natural and synthetic chemicals lead us to suggest to a new class of less toxic but more effective pesticides. We call it group as CSYNAP, i. e. Combination of SYnthetic and NAtural products as Pesticides.

  5. Comparative evaluation of Etest and sensititre yeastone panels against the Clinical and Laboratory Standards Institute M27-A2 reference broth microdilution method for testing Candida susceptibility to seven antifungal agents.

    PubMed

    Alexander, Barbara D; Byrne, Terry C; Smith, Kelly L; Hanson, Kimberly E; Anstrom, Kevin J; Perfect, John R; Reller, L Barth

    2007-03-01

    To assess their utility for antifungal susceptibility testing in our clinical laboratory, the Etest and Sensititre methods were compared with the Clinical and Laboratory Standards Institute (CLSI) M27-A2 reference broth microdilution method. Fluconazole (FL), itraconazole (I), voriconazole (V), posaconazole (P), flucytosine (FC), caspofungin (C), and amphotericin B (A) were tested with 212 Candida isolates. Reference MICs were determined after 48 h of incubation, and Etest and Sensititre MICs were determined after 24 h and 48 h of incubation. Overall, excellent essential agreement (EA) between the reference and test methods was observed for Etest (95%) and Sensititre (91%). Etest showed an >or=92% EA for MICs for all drugs tested; Sensititre showed a >or=92% EA for MICs for I, FC, A, and C but 82% for FL and 85% for V. The overall categorical agreement (CA) was 90% for Etest and 88% for Sensititre; minor errors accounted for the majority of all categorical errors for both systems. Categorical agreement was lowest for Candida glabrata and Candida tropicalis with both test systems. Etest and Sensititre provided better CA at 24 h compared to 48 h for C. glabrata; however, CA for C. glabrata was <80% for FL with both test systems despite MIC determination at 24 h. Agreement between technologists for both methods was >or=98% for each agent against all organisms tested. Overall, Etest and Sensititre methods compared favorably with the CLSI reference method for determining the susceptibility of Candida. However, further evaluation of their performance for determining the MICs of azoles, particularly for C. glabrata, is warranted.

  6. 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

  7. Azole drugs are imported by facilitated diffusion in Candida albicans and other pathogenic fungi.

    PubMed

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

    2010-09-30

    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 K(m) of 0.64 μM and V(max) 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.

  8. Accumulation of Azole Drugs in the Fungal Plant Pathogen Magnaporthe oryzae Is the Result of Facilitated Diffusion Influx.

    PubMed

    Esquivel, Brooke D; White, Theodore C

    2017-01-01

    Magnaporthe oryzae is an agricultural mold that causes disease in rice, resulting in devastating crop losses. Since rice is a world-wide staple food crop, infection by M. oryzae poses a serious global food security threat. Fungicides, including azole antifungals, are used to prevent and combat M. oryzae plant infections. The target of azoles is CYP51, an enzyme localized on the endoplasmic reticulum (ER) and required for fungal ergosterol biosynthesis. However, many basic drug-pathogen interactions, such as how the azole gets past the fungal cell wall and plasma membrane, and is transported to the ER, are not understood. In addition, reduced intracellular accumulation of antifungals has consistently been observed as a drug resistance mechanism in many fungal species. Studying the basic biology of drug-pathogen interactions may elucidate uncharacterized mechanisms of drug resistance and susceptibility in M. oryzae and potentially other related fungal pathogens. We characterized intracellular accumulation of azole drugs in M. oryzae using a radioactively labeled fluconazole uptake assay to gain insight on whether azoles enter the cell by passive diffusion, active transport, or facilitated diffusion. We show that azole accumulation is not ATP-dependent, nor does it rely on a pH-dependent process. Instead there is evidence for azole drug uptake in M. oryzae by a facilitated diffusion mechanism. The uptake system is specific for azole or azole-like compounds and can be modulated depending on cell phase and growth media. In addition, we found that co-treatment of M. oryzae with 'repurposed' clorgyline and radio-labeled fluconazole prevented energy-dependent efflux of fluconazole, resulting in an increased intracellular concentration of fluconazole in the fungal cell.

  9. 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. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. [NEW ANTIFUNGAL DRUGS FOR PREVENTION AND TREATMENT OF VISCERAL MYCOSES].

    PubMed

    Pilmis, Benoît; Lortholary, Olivier; Lanternier, Fanny L

    2015-12-01

    Invasive fungal infections are increasing due to the increase in the number of at risk patients. The antifungal armamentarium has been improved the last few years with new galenic for ampoetericin B, the widening of the azole spectrum with voriconazole, poscaonazole and isavuconazole and the launch of a new antifungal class, the eschinocandins, currently represented by casoefungin and micftungin. The aim of this work is to provide an update in new antifungal drugs available.

  11. Antifungal Susceptibility Testing of Ascomycetous Yeasts Isolated from Animals

    PubMed Central

    Álvarez-Pérez, Sergio; García, Marta E.; Peláez, Teresa; Martínez-Nevado, Eva

    2016-01-01

    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

  12. Novel high-throughput screen against Candida albicans identifies antifungal potentiators and agents effective against biofilms

    PubMed Central

    LaFleur, Michael D.; Lucumi, Edinson; Napper, Andrew D.; Diamond, Scott L.; Lewis, Kim

    2011-01-01

    Objectives Microbial adhesion and biofilms have important implications for human health and disease. Candida albicans is an opportunistic pathogen which forms drug-resistant biofilms that contribute to the recalcitrance of disease. We have developed a high-throughput screen for potentiators of clotrimazole, a common therapy for Candida infections, including vaginitis and thrush. The screen was performed against C. albicans biofilms grown in microtitre plates in order to target the most resilient forms of the pathogen. Methods Biofilm growth, in individual wells of 384-well plates, was measured using the metabolic indicator alamarBlue® and found to be very consistent and reproducible. This assay was used to test the effect of more than 120 000 small molecule compounds from the NIH Molecular Libraries Small Molecule Repository, and compounds that enhanced the activity of clotrimazole or acted on the biofilms alone were identified as hits. Results Nineteen compounds (0.016% hit rate) were identified and found to cause more than 30% metabolic inhibition of biofilms compared with clotrimazole alone, which had a modest effect on biofilm viability at the concentration tested. Hits were confirmed for activity against biofilms with dose–response measurements. Several compounds had increased activity in combination with clotrimazole, including a 1,3-benzothiazole scaffold that exhibited a >100-fold improvement against biofilms of three separate C. albicans isolates. Cytotoxicity experiments using human fibroblasts confirmed the presence of lead molecules with favourable antifungal activity relative to cytotoxicity. Conclusions We have validated a novel approach to identify antifungal potentiators and completed a high-throughput screen to identify small molecules with activity against C. albicans biofilms. These small molecules may specifically target the biofilm and make currently available antifungals more effective. PMID:21393183

  13. In vitro susceptibility of Sporothrix schenckii to six antifungal agents determined using three different methods.

    PubMed

    Alvarado-Ramírez, Eidi; Torres-Rodríguez, Josep M

    2007-07-01

    The in vitro susceptibility of Sporothrix schenckii to antifungal drugs has been determined with three different methods. Nineteen Peruvian clinical isolates of S. schenckii were tested against amphotericin B (AB), flucytosine (FC), fluconazole (FZ), itraconazole (IZ), voriconazole (VZ), and ketoconazole (KZ). Modified NCCLS M38-A, Sensititre YeastOne (SYO), and ATB Fungus 2 (ATBF2) methods were used to determine the MICs. ATCC isolates of Candida parapsilosis, Candida krusei, and Aspergillus flavus were used for quality control. Sporothrix inocula were prepared with the mycelial form growing on potato dextrose agar at 28 +/- 2 degrees C. MICs of AB, FC, FZ, and IZ were determined with all three methods, VZ with M38-A and SYO, and KZ with only SYO. The three methods showed high MICs of FZ and FC (MIC(90) of 0.5 microg/ml), being homogeneously lower than those of IZ and KZ. The M38-A method showed a variable MIC range of VZ (4.0 to 16 microg/ml); the geometric mean (GM) was 9.3 mug/ml. The MIC range of AB was wide (0.06 to 16 microg/ml), but the GM was 1.2 microg/ml, suggesting that the MIC is strain dependent. Agreement (two log(2) dilutions) between commercial techniques and the modified M38-A method was very high with FZ, IZ, and FC. In AB and VZ, the agreement was lower, being related to the antifungal concentrations of each method. The highest activity against S. schenckii was found with IZ and KZ. Lack of activity was observed with FZ, VZ, and FC. When AB is indicated for sporotrichosis, the susceptibility of the strain must be analyzed. Commercial quantitative antifungal methods have a limited usefulness in S. schenckii.

  14. Susceptibility to antifungal agents and genotypes of Brazilian clinical and environmental Cryptococcus gattii strains.

    PubMed

    Silva, Dayane C; Martins, Marilena A; Szeszs, Maria Walderez; Bonfietti, Lucas X; Matos, Dulcilena; Melhem, Marcia S C

    2012-04-01

    There are few reports concerning the in vitro antifungal susceptibility of clinical and environmental Cryptococcus gattii isolates. In this study, we performed polymerase chain reaction-restriction fragment length polymorphism to investigate the molecular subtypes of 50 clinical and 4 environmental Brazilian isolates of C. gattii and assessed their antifungal susceptibility for fluconazole (FLU) and amphotericin B (Amb) according to recent recommendations proposed for antifungal susceptibility testing of nonfermentative yeasts. Time-kill curve studies were performed using RPMI 1640 medium to analyze the fungicidal effect of AmB. We found 47 VGII (94%) molecular types and 3 VGI (6%) types among the clinical isolates. The environmental isolates were VGII (75%) subtype and VGI (25%) subtype. The FLU-MIC ranged from 1 to 64 mg L(-1), and MIC(50)/MIC(90) values were, respectively, 8/16 mg L(-1). For AmB, the MICs were low and homogeneous, ranging from 0.12 to 0.5 mg L(-1), for VGI or VGII. The time required to reach the fungicidal end point (99.9% killing) was 6 h for the majority of strains (64%), but viable cells of VGII were still present after 48 h of exposition. We pointed out the occurrence of high FLU-MICs for C. gattii isolates with highest values for VGII. Our data also suggest that the rate of killing of C. gattii by AmB is strain dependent, and viable cells of VGII genotype strains were still observed after an extended incubation time, addressing future studies to determine whether the in vitro fungicidal activity could be clinically relevant.

  15. 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.

  16. 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.

  17. Synthesis of new triazolyl-N,N-dialkyldithiocarbamates as antifungal agents.

    PubMed

    Ozkirimli, Sumru; Apak, T Idil; Kiraz, Muammer; Yegenoglu, Yildiz

    2005-11-01

    N,N-Dialkylditihiocarbamate derivatives have been well known as broad-range fungicides. In this study, the triazole derivatives of ten new N,N-disubstituted dithiocarbamates (3a-j) were synthesized and their structures were identified by spectral and elemental analysis. Results of the antifungal activity studies showed that some of the compounds tested were active against M. canis, M. gypseum, and T. rubrum at the concentration of 12.5 microg/mL when clotrimazol was used as a standard.

  18. Clinical pharmacology of antifungal agents in pediatrics: children are not small adults.

    PubMed

    Ramos-Martín, Virginia; O'Connor, Olya; Hope, William

    2015-10-01

    The optimal dosage information to improve the prognosis of invasive fungal infections in children and neonates is still limited and current dosing strategies are supported mainly by adult studies and extrapolation. Significant progress has been made to address this need in the last decade. Pre-clinical models and pharmacokinetic-pharmacodynamic (PK-PD) bridging studies supported by pediatric pharmacokinetic studies have investigated optimal dosing regimens for neonates and children. Here, we review the rationale for various antifungal regimens in infants and children.

  19. Synthesis of some N-alkyl substituted urea derivatives as antibacterial and antifungal agents.

    PubMed

    Zheng, Qing-Zhong; Cheng, Kui; Zhang, Xiao-Min; Liu, Kai; Jiao, Qing-Cai; Zhu, Hai-Liang

    2010-07-01

    A series of N-alkyl substituted urea derivatives were synthesized and evaluated for their in vitro antibacterial and antifungal activities. The N-alkyl substituted urea derivatives bearing morpholine moiety (3a-3k) showed better activities than those bearing diethylamine moiety (2a-2f). Compounds having fluoro substituent at ortho (3c) and para (3b) positions of the phenyl ring exhibited potent antimicrobial activities against Gram-positive and Gram-negative bacteria as well as fungi. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

  20. Azole fungicides affect mammalian steroidogenesis by inhibiting sterol 14 alpha-demethylase and aromatase.

    PubMed

    Zarn, Jürg A; Brüschweiler, Beat J; Schlatter, Josef R

    2003-03-01

    Azole compounds play a key role as antifungals in agriculture and in human mycoses and as non-steroidal antiestrogens in the treatment of estrogen-responsive breast tumors in postmenopausal women. This broad use of azoles is based on their inhibition of certain pathways of steroidogenesis by high-affinity binding to the enzymes sterol 14-alpha-demethylase and aromatase. Sterol 14-alpha-demethylase is crucial for the production of meiosis-activating sterols, which recently were shown to modulate germ cell development in both sexes of mammals. Aromatase is responsible for the physiologic balance of androgens and estrogens. At high doses, azole fungicides and other azole compounds affect reproductive organs, fertility, and development in several species. These effects may be explained by inhibition of sterol 14-alpha-demethylase and/or aromatase. In fact, several azole compounds were shown to inhibit these enzymes in vitro, and there is also strong evidence for inhibiting activity in vivo. Furthermore, the specificity of the enzyme inhibition of several of these compounds is poor, both with respect to fungal versus nonfungal sterol 14-alpha-demethylases and versus other P450 enzymes including aromatase. To our knowledge, this is the first review on sterol 14-alpha-demethylase and aromatase as common targets of azole compounds and the consequence for steroidogenesis. We conclude that many azole compounds developed as inhibitors of fungal sterol 14-alpha-demethylase are inhibitors also of mammalian sterol 14-alpha-demethylase and mammalian aromatase with unknown potencies. For human health risk assessment, data on comparative potencies of azole fungicides to fungal and human enzymes are needed.

  1. Azole fungicides affect mammalian steroidogenesis by inhibiting sterol 14 alpha-demethylase and aromatase.

    PubMed Central

    Zarn, Jürg A; Brüschweiler, Beat J; Schlatter, Josef R

    2003-01-01

    Azole compounds play a key role as antifungals in agriculture and in human mycoses and as non-steroidal antiestrogens in the treatment of estrogen-responsive breast tumors in postmenopausal women. This broad use of azoles is based on their inhibition of certain pathways of steroidogenesis by high-affinity binding to the enzymes sterol 14-alpha-demethylase and aromatase. Sterol 14-alpha-demethylase is crucial for the production of meiosis-activating sterols, which recently were shown to modulate germ cell development in both sexes of mammals. Aromatase is responsible for the physiologic balance of androgens and estrogens. At high doses, azole fungicides and other azole compounds affect reproductive organs, fertility, and development in several species. These effects may be explained by inhibition of sterol 14-alpha-demethylase and/or aromatase. In fact, several azole compounds were shown to inhibit these enzymes in vitro, and there is also strong evidence for inhibiting activity in vivo. Furthermore, the specificity of the enzyme inhibition of several of these compounds is poor, both with respect to fungal versus nonfungal sterol 14-alpha-demethylases and versus other P450 enzymes including aromatase. To our knowledge, this is the first review on sterol 14-alpha-demethylase and aromatase as common targets of azole compounds and the consequence for steroidogenesis. We conclude that many azole compounds developed as inhibitors of fungal sterol 14-alpha-demethylase are inhibitors also of mammalian sterol 14-alpha-demethylase and mammalian aromatase with unknown potencies. For human health risk assessment, data on comparative potencies of azole fungicides to fungal and human enzymes are needed. PMID:12611652

  2. 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

  3. Antimicrobial peptides as potential new antifungals.

    PubMed

    Müller, F M; Lyman, C A; Walsh, T J

    1999-01-01

    Ribosomally synthesized natural antimicrobial peptides (AP) and their synthetic derivatives are small, cationic, amphipathic molecules of 12-50 amino acids with unusually broad activity spectra. These peptides kill microorganisms by a common mechanism, which involves binding to the lipid bilayer of biological membranes, forming pores, and ultimately followed by cell lysis. Several AP from mammals, amphibians, insects, plants and their synthetic derivatives demonstrate promising in vitro activity against various pathogenic fungi including azole-resistant Candida albicans strains. In addition to their antimicrobial activity, some AP such as lactoferrin, interact with a variety of host cells and can increase the activity of natural killer and lymphokine activated killer cells. Pretreatment of polymorphonuclear neutrophil leukocytes (PMN) or monocytes with these AP also may upregulate superoxide release. AP as potential new antifungal agents offer some advantages, such as rapid killing of pathogenic fungi and the difficulty to raise mutants resistant to these peptides. AP are limited by their nonselective toxicity, stability, immunogenicity and their costs of production. Potential clinical applications of AP in the future have to be further explored in preclinical and clinical studies to assess their impact as a new class of antifungals.

  4. Induction of Resistance to Azole Drugs in Trypanosoma cruzi

    PubMed Central

    Buckner, Frederick S.; Wilson, Aaron J.; White, Theodore C.; Van Voorhis, Wesley C.

    1998-01-01

    Trypanosoma cruzi is the protozoan parasite that causes Chagas’ disease, a frequently fatal illness affecting the heart and gastrointestinal systems. An estimated 16 million to 18 million people in Latin America and 50,000 to 100,000 people in the United States are infected with this pathogen. Treatment options for T. cruzi infections are suboptimal due to the toxicities and limited effectiveness of the available drugs. Azole antimicrobial agents have been discovered to have antitrypanosomal activity by inhibition of ergosterol synthesis. The triazole itraconazole was recently shown to produce a parasitologic cure rate of 53% in chronically infected patients (W. Apt et al., Am. J. Trop. Med. Hyg. 59:133–138, 1998), a result which may lead to more use of this family of drugs for the treatment of T. cruzi infections. In the experiments reported on here, resistance to azoles was induced in vitro by serial passage of mammalian-stage parasites in the presence of fluconazole for 4 months. These parasites were cross resistant to the other azoles, ketoconazole, miconazole, and itraconazole. They remained susceptible to benznidazole and amphotericin B. The azole-resistant phenotype was stable for more than 2 months of in vitro serial passage without fluconazole. In addition, the parasites resisted treatment in mice receiving ketoconazole. The rapid development of azole resistance in T. cruzi in vitro suggests that resistance to azole drugs has the potential to occur in patients and may pose an impediment to the progress being made in the treatment of T. cruzi infection. PMID:9835521

  5. Differential effects of antifungal agents on expression of genes related to formation of Candida albicans biofilms.

    PubMed

    Chatzimoschou, Athanasios; Simitsopoulou, Maria; Antachopoulos, Charalampos; Walsh, Thomas J; Roilides, Emmanuel

    2016-01-01

    The purpose of this study was to analyse specific molecular mechanisms involved in the intrinsic resistance of C. albicans biofilms to antifungals. We investigated the transcriptional profile of three genes (BGL2, SUN41, ECE1) involved in Candida cell wall formation in response to voriconazole or anidulafungin after the production of intermediate and mature biofilms. C. albicans M61, a well-documented biofilm producer strain, was used for the development of intermediate (12 h and 18 h) and completely mature biofilms (48 h). After exposure of cells from each biofilm growth mode to voriconazole (128 and 512 mg l(-1)) or anidulafungin (0.25 and 1 mg l(-1)) for 12-24 h, total RNA samples extracted from biofilm cells were analysed by RT-PCR. The voriconazole and anidulafungin biofilm MIC was 512 and 0.5 mg l(-1) respectively. Anidulafungin caused significant up-regulation of SUN41 (3.7-9.3-fold) and BGL2 (2.2-2.8 fold) in intermediately mature biofilms; whereas, voriconazole increased gene expression in completely mature biofilms (SUN41 2.3-fold, BGL2 2.1-fold). Gene expression was primarily down-regulated by voriconazole in intermediately, but not completely mature biofilms. Both antifungals caused down-regulation of ECE1 in intermediately mature biofilms.

  6. Species assignment and antifungal susceptibilities of black aspergilli recovered from otomycosis cases in Iran.

    PubMed

    Szigeti, Gyöngyi; Sedaghati, Ebrahim; Mahmoudabadi, Ali Zarei; Naseri, Ali; Kocsubé, Sándor; Vágvölgyi, Csaba; Varga, János

    2012-07-01

    Black aspergilli are among the main causative agents of otomycosis worldwide. In this study, the species assignment of black aspergilli isolated from otomycosis cases in Iran was carried out using sequence analysis of part of the calmodulin gene. The results indicate that Aspergillus niger is not the only black Aspergillus species involved in otomycosis cases in Iran: Aspergillus awamori and Aspergillus tubingensis are also able to cause ear infections. Antifungal susceptibility tests were carried out against five antifungal drugs including amphotericin B, fluconazole, itraconazole, ketoconazole and terbinafine. All isolates were highly susceptible to terbinafine, while they exhibited moderate susceptibilities against amphotericin B, fluconazole and ketoconazole. Aspergillus niger and A. awamori were found to have higher minimal inhibitory concentrations for azoles than A. tubingensis, in accordance with previous findings.

  7. Antifungal drug resistance mechanisms.

    PubMed

    Pemán, Javier; Cantón, Emilia; Espinel-Ingroff, Ana

    2009-05-01

    Antifungal resistance is a prominent feature in the management of invasive mycoses, with important implications for morbidity and mortality. Microbiological resistance, the most common cause of refractory infection, is associated with a fungal pathogen for which an antifungal MIC is higher than average or within the range designated as the resistant breakpoint. Four major mechanisms of resistance to azoles have been described in Candida spp.: decreased intracellular drug concentration by activation of efflux systems or reduction of drug penetration, modification of the target site, upregulation of the target enzyme and development of bypass pathways. Conversely, echinocandins are a poor substrate for multidrug efflux transporters, and their mechanisms of resistance are associated with point mutations and/or overexpression of FKS1 and FKS2 genes. Acquired resistance to flucytosine results from defects in its metabolism through enzymatic mutations, whereas resistance to amphotericin B may be mediated by increased catalase activity or defects in ergosterol biosynthesis.

  8. 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

  9. Carboxymethylated chitosan-stabilized copper nanoparticles: a promise to contribute a potent antifungal and antibacterial agent

    NASA Astrophysics Data System (ADS)

    Tantubay, Sangeeta; Mukhopadhyay, Sourav K.; Kalita, Himani; Konar, Suraj; Dey, Satyahari; Pathak, Amita; Pramanik, Panchanan

    2015-06-01

    Carboxymethylated chitosan (CMC)-stabilized copper nanoparticles (Cu-NPs) have been synthesized via chemical reduction of copper(II)-CMC complex in aqueous medium by hydrazine under microwave irradiation in ambient atmosphere. Structural morphology, phase, and chemical compositions of CMC-stabilized Cu-NPs (CMC-Cu-NPs) have been analyzed through high-resolution transmission electron microscopy, field emission scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Antifungal and antibacterial activities of CMC-Cu-NPs have been evaluated against Candida tropicalis and Escherichia coli through agar well diffusion method, broth microdilution assay, live-dead assay, and microscopic observation. Antimicrobial activity of spherical CMC-Cu-NPs ( 4-15 nm of diameters) has been observed to be significant for both C. tropicalis and E. coli. The cytotoxicity study indicates that CMC-Cu-NPs have no significant toxic effect against normal cell line, L929.

  10. 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

    2013-05-03

    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.

  11. Passicol, an Antibacterial and Antifungal Agent Produced by Passiflora Plant Species: Preparation and Physicochemical Characteristics

    PubMed Central

    Birner, J.; Nicolls, Joan M.

    1973-01-01

    An increased yield of the crude material with antibacterial and antifungal activity produced by Passiflora species was obtained by aerated bathing of cut rinds of banana passion fruit in water in rotating cylindrical bottles. The crude material was separated into several fractions by thin-layer chromatography with the use of silica gel and ethyl acetate-chloroform (2:1). The fractions showing ultraviolet absorption maxima in the vicinity of 340, 358, and 375 to 377 nm were biologically active. The data indicate that the active material, here called “Passicol” for the first time, has characteristics of the polyacetylenic group of compounds. The activity can be preserved for a long time when crude material is stored in organic solvent in the dark at 6 C. Gentle bathing of the cut rinds of Passiflora in water in the presence of air and ethylene stimulated the formation of the active principle. Images PMID:4790566

  12. Synthesis and Biological Evaluation of Benzimidazole Phenylhydrazone Derivatives as Antifungal Agents against Phytopathogenic Fungi.

    PubMed

    Wang, Xing; Chen, Yong-Fei; Yan, Wei; Cao, Ling-Ling; Ye, Yong-Hao

    2016-11-22

    A series of benzimidazole phenylhydrazone derivatives (6a-6ai) were synthesized and characterized by ¹H-NMR, ESI-MS, and elemental analysis. The structure of 6b was further confirmed by single crystal X-ray diffraction as (E)-configuration. All the compounds were screened for antifungal activity against Rhizoctonia solani and Magnaporthe oryzae employing a mycelium growth rate method. Compound 6f exhibited significant inhibitory activity against R. solani and M. oryzae with the EC50 values of 1.20 and 1.85 μg/mL, respectively. In vivo testing demonstrated that 6f could effectively control the development of rice sheath blight (RSB) and rice blast (RB) caused by the above two phytopathogens. This work indicated that the compound 6f with a benzimidazole phenylhydrazone scaffold could be considered as a leading structure for the development of novel fungicides.

  13. Targeting efflux pumps to overcome antifungal drug resistance.

    PubMed

    Holmes, Ann R; Cardno, Tony S; Strouse, J Jacob; Ivnitski-Steele, Irena; Keniya, Mikhail V; Lackovic, Kurt; Monk, Brian C; Sklar, Larry A; Cannon, Richard D

    2016-08-01

    Resistance to antifungal drugs is an increasingly significant clinical problem. The most common antifungal resistance encountered is efflux pump-mediated resistance of Candida species to azole drugs. One approach to overcome this resistance is to inhibit the pumps and chemosensitize resistant strains to azole drugs. Drug discovery targeting fungal efflux pumps could thus result in the development of azole-enhancing combination therapy. Heterologous expression of fungal efflux pumps in Saccharomyces cerevisiae provides a versatile system for screening for pump inhibitors. Fungal efflux pumps transport a range of xenobiotics including fluorescent compounds. This enables the use of fluorescence-based detection, as well as growth inhibition assays, in screens to discover compounds targeting efflux-mediated antifungal drug resistance. A variety of medium- and high-throughput screens have been used to identify a number of chemical entities that inhibit fungal efflux pumps.

  14. An in vitro study of antifungal drug susceptibility of Candida species isolated from human immunodeficiency virus seropositive and human immunodeficiency virus seronegative individuals in Lucknow population Uttar Pradesh

    PubMed Central

    Dar, Mohammad Shafi; Sreedar, Gadiputi; Shukla, Abhilasha; Gupta, Prashant; Rehan, Ahmad Danish; George, Jiji

    2015-01-01

    Background: Candidiasis is the most common opportunistic infection in human immunodeficiency virus (HIV) seropositive patients, starting from asymptomatic colonization to pathogenic forms and gradual colonization of non-albicans in patients with advanced immunosuppression leads to resistance for azole group of antifungal drugs with high rate of morbidity and mortality. Objectives: To isolate the Candida species and determine of antifungal drug susceptibility against fluconazole, itraconazole, nystatin, amphotericin B, and clotrimazolein HIV seropositive and control individuals, with or without clinical oropharyngeal candidiasis (OPC). Materials and Methods: Includes samples from faucial region of 70 subjects with and without clinical candidiasis in HIV seropositive and controls were aseptically inoculated onto Sabaraud's Dextrose Agar media and yeasts were identified for the specific species by Corn Meal Agar, sugar fermentation and heat tolerance tests. Antifungal drug susceptibility of the isolated species was done against above-mentioned drugs by E-test and disc diffusion method. Results: The commonly isolated species in HIV seropositive and controls were Candida albicans, Candida glabrata and Candida tropicalis Candida guilliermondii and Candida dubliniensis isolated only in HIV seropositive patients. Susceptibility against selected antifungal drugs was observed more in HIV-negative individuals whereas susceptible dose-dependent and resistance were predominant in HIV-positive patients. Conclusion: Resistance is the major problem in the therapy of OPC, especially in HIV seropositive patients due to aggressive and prolonged use of antifungal agents, therefore, our study emphasizes the need for antifungal drug susceptibility testing whenever antifungal treatment is desired, especially in HIV-infected subjects. PMID:26604498

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

    PubMed

    Abdolrasouli, Alireza; Rhodes, Johanna; Beale, Mathew A; Hagen, Ferry; Rogers, Thomas R; Chowdhary, Anuradha; Meis, Jacques F; Armstrong-James, Darius; Fisher, Matthew C

    2015-06-02

    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. Resistance to azoles in the ubiquitous ascomycete fungus A. fumigatus was first reported from clinical isolates collected in the United States during the late 1980s

  16. 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.

  17. Antifungal resistance in yeast vaginitis.

    PubMed Central

    Dun, E.

    1999-01-01

    The increased number of vaginal yeast infections in the past few years has been a disturbing trend, and the scientific community has been searching for its etiology. Several theories have been put forth to explain the apparent increase. First, the recent widespread availability of low-dosage, azole-based over-the-counter antifungal medications for vaginal yeast infections encourages women to self-diagnose and treat, and women may be misdiagnosing themselves. Their vaginitis may be caused by bacteria, parasites or may be a symptom of another underlying health condition. As a result, they may be unnecessarily and chronically expose themselves to antifungal medications and encourage fungal resistance. Second, medical technology has increased the life span of seriously immune compromised individuals, yet these individuals are frequently plagued by opportunistic fungal infections. Long-term and intense azole-based antifungal treatment has been linked to an increase in resistant Candida and non-Candida species. Thus, the future of limiting antifungal resistance lies in identifying the factors promoting resistance and implementing policies to prevent it. PMID:10907778

  18. Perillaldehyde, a Promising Antifungal Agent Used in Food Preservation, Triggers Apoptosis through a Metacaspase-Dependent Pathway in Aspergillus flavus.

    PubMed

    Tian, Jun; Wang, Yanzhen; Lu, Zhaoqun; Sun, Chunhui; Zhang, Man; Zhu, Aihua; Peng, Xue

    2016-10-05

    In the present study, we provide detailed insights into perillaldehyde (PAE)'s mechanisms of action on Aspergillus flavus and offer evidence in favor of the induction of an apoptosis-like phenotype. Specifically, PAE's antifungal mode of action was investigated through the detection of mitochondrial membrane potential (MtΔψ) and phosphatidylserine (PS) exposure, as well as intracellular Ca(2+) level, reactive oxygen species accumulation, and metacaspase activation. This was done by way of fluorometry, measuring DNA fragmentation, and condensation by fluorescent microscopy. Furthermore, we searched for phenotypic changes characteristic of apoptosis by transmission electron microscopy and flow cytometry, determining the amount of cytochrome c released using Western blotting. Results indicated that cultivation of A. flavus in the presence of PAE caused depolarization of MtΔψ, rapid DNA condensation, large-scale DNA fragmentation, and an elevation of intracellular Ca(2+) level. The percentage of early apoptotic cells with exposure of PS were 27.4% and 48.7%, respectively, after 9 h incubations with 0.25 and 0.5 μL/mL of PAE. The percentage of stained cells with activated intracellular metacaspases exposed to PAE at concentrations of 0.25 and 0.5 μL/mL compared with control subjects were increased by 28.4 ± 3.25% and 37.9 ± 4.24%, respectively. The above results has revealed that PAE induces fungal apoptosis through a caspase-dependent mitochondrial pathway. In all, our findings provide a novel mechanism for exploring a possible antifungal agent used in food preservation.

  19. Evaluation of the conjunctival fungal flora and its susceptibility to antifungal agents in healthy horses in Switzerland.

    PubMed

    Voelter-Ratson, Katrin; Monod, Michel; Unger, Lucia; Spiess, Bernhard M; Pot, Simon A

    2014-07-01

    To characterize the conjunctival fungal flora and to determine the susceptibility of 2 isolated molds to antifungal drugs in samples of 64 healthy horses from The National Stud in Switzerland. Conjunctival cytobrush samples were collected from both eyes of 64 ophthalmologically normal horses in August 2012 and subsequently cultured on Sabouraud's agar medium. Growing fungi were identified and counted. Etests or broth microdilution tests for Aspergillus fumigatus and Eurotium amstelodami were carried out to determine antifungal drug sensitivity. These species had previously been detected in samples from eyes with keratomycosis in Switzerland. Minimal inhibitory concentrations (MICs) for voriconazole, fluconazole, itraconazole, amphotericin B, and miconazole were recorded. Fifty-nine of the horses were tested positive for fungal growth from at least one eye (92%). Eleven genera of fungi were identified. The most common fungal genera were Alternaria, Eurotium, Rhizopus, and Cladosporium. Aspergillus spp. and Penicillium spp. were isolated frequently, while no Fusarium spp. was found. In only 2 cases, yeasts were identified as Candida guilliermondii. For certain fungal species, the type of bedding and housing appeared to influence their prevalence. Susceptibility testing of A. fumigatus showed lowest MICs for voriconazole, E. amstelodami for voriconazole and itraconazole. High MICs for fluconazole were detected for all tested fungi while MICs for amphotericin B and miconazole were variable. A large range of fungal mold species was identified including A. fumigatus and E. amstelodami, which have been causative agents of keratomycosis in Switzerland. Best in vitro susceptibility results for these two species were obtained for voriconazole. © 2013 American College of Veterinary Ophthalmologists.

  20. Pre-clinical development of antifungal susceptibility test methods for the testing of the novel antifungal agent E1210 versus Candida: comparison of CLSI and European Committee on Antimicrobial Susceptibility Testing methods.

    PubMed

    Pfaller, Michael A; Watanabe, Naoaki; Castanheira, Mariana; Messer, Shawn A; Jones, Ronald N

    2011-11-01

    To compare European Committee on Antimicrobial Susceptibility Testing (EUCAST) and CLSI broth microdilution (BMD) methods for testing the novel antifungal E1210 against a recent collection of 102 clinical isolates of Candida spp. Candida isolates (102) were tested by CLSI and EUCAST methods; 21 Candida albicans, 20 Candida glabrata, 25 Candida parapsilosis, 24 Candida tropicalis and 12 Candida krusei, including echinocandin- and azole-resistant isolates. CLSI and EUCAST MIC endpoints of 50% and 100% inhibition were determined using visual reading at 24 and 48 h of incubation and spectrophotometric reading at 24 h of incubation, respectively. E1210 CLSI MIC results ranged from ≤0.008 to only 1 mg/L (excluding C. krusei) depending on species, duration of incubation and endpoint criteria (EC). E1210 was not active against C. krusei (MIC(50) >16 mg/L). Overall essential agreement (EA; ±2 doubling dilutions) between the 24 and 48 h CLSI readings was 100% and 97.6% using the 50% and 100% inhibition EC, respectively. Slightly more trailing growth at 48 h was observed with the 100% inhibition EC. Comparison of the 50% and 100% endpoints at 24 h of incubation showed an overall EA of 100%. Comparison of CLSI and EUCAST read at 24 h of incubation and either 50% or 100% inhibition revealed an EA of 97.8% using the 50% inhibition EC and 88.9% using the 100% inhibition EC. E1210 was found to have potent in vitro activity against Candida spp. when tested by both CLSI and EUCAST BMD methods, with the highest overall EA (97.8%) obtained when E1210 MIC results were read after 24 h of incubation using a partial inhibition EC.

  1. 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

  2. Peptide derived from anti-idiotypic single-chain antibody is a potent antifungal agent compared to its parent fungicide HM-1 killer toxin peptide.

    PubMed

    Kabir, M Enamul; Karim, Nurul; Krishnaswamy, Senthilkumar; Selvakumar, Dakshnamurthy; Miyamoto, Masahiko; Furuichi, Yasuhiro; Komiyama, Tadazumi

    2011-12-01

    Based on anti-idiotypic network theory in light of the need for new antifungal drugs, we attempted to identify biologically active fragments from HM-1 yeast killer toxin and its anti-idiotypic antibody and to compare their potency as an antifungal agent. Thirteen overlapping peptides from HM-1 killer toxin and six peptides from its anti-idiotypic single-chain variable fragment (scFv) antibodies representing the complementarity determining regions were synthesized. The binding affinities of these peptides were investigated and measured by Dot blot and surface plasmon resonance analysis and finally their antifungal activities were investigated by inhibition of growth, colony forming unit assay. Peptide P6, containing the potential active site of HM-1 was highly capable of inhibiting the growth of Saccharomyces cerevisiae but was less effective on pathogenic fungi. However, peptide fragments derived from scFv antibody exerted remarkable inhibitory effect on the growth of pathogenic strains of Candida and Cryptococcus species in vitro. One scFv-derived decapeptide (SP6) was selected as the strongest killer peptide for its high binding affinity and antifungal abilities on both Candida and Cryptococcus species with IC(50) values from 2.33 × 10(-7) M to 36.0 × 10(-7) M. SP6 peptide activity was neutralized by laminarin, a β-1,3-glucan molecule, indicating this peptide derived from scFv anti-idiotypic antibody retains antifungal activity through interaction with cell wall β-glucan of their target fungal cells. Experimental evidence strongly suggested the possibility of development of anti-idiotypic scFv peptide-based antifungal agents which may lead to improve therapeutics for the management of varieties of fungal infections.

  3. Fisetin as a promising antifungal agent against Cryptocococcus neoformans species complex.

    PubMed

    Reis, M P C; Carvalho, C R C; Andrade, F A; Fernandes, O F L; Arruda, W; Silva, M R R

    2016-08-01

    The aim of this study was to investigate the mechanisms of action of fisetin, a flavonol with antifungal activity previously evaluated against the Cryptococcus neoformans species complex. Ergosterol content and flow cytometry analysis were determined for the C. neoformans species complex in the presence of fisetin and ultrastructural analysis of morphology was performed on Cryptococcus gattii and C. neoformans. Decrease in the total cellular ergosterol content after exposure to fisetin ranged from 25·4% after exposure to 128 μg ml(-1) to 21·6% after exposure to 64 μg ml(-1) of fisetin compared with the control (without fisetin). The fisetin effects obtained with flow cytometry showed metabolic impairment, and alterations in its normal morphology caused by fisetin in C. neoformans cells were verified using scanning electron microscopy. Fisetin is a compound that acts in the biosynthesis of ergosterol. Flow cytometry showed that fisetin reduced viability of the metabolically active cells of C. gattii, while morphological changes explain the action of fisetin in inhibiting growth of these fungi. This study supports the idea that fisetin may represent a good starting point for the development of future therapeutic substances for cryptococcosis. © 2016 The Society for Applied Microbiology.

  4. Respiratory chain of a pathogenic fungus, Microsporum gypseum: effect of the antifungal agent pyrrolnitrin.

    PubMed

    Wong, D T; Horng, J S; Gordee, R S

    1971-04-01

    Pyrrolnitrin has been reported to inhibit Bacillus megaterium primarily by forming complexes with phospholipids and to block electron transfer of Saccharomyces cerevisiae between succinate or reduced nicotinamide adenine dinucleotide (NADH) and coenzyme Q. We found that pyrrolnitrin inhibited respiration of conidia of Microsporum gypseum. In mitochondrial preparations, pyrrolnitrin strongly inhibited respiration and the rotenone-sensitive NADH-cytochrome c reductase. The rotenone-insensitive NADH-cytochrome c reductase, the succinate-cytochrome c reductase, and the reduction of dichlorophenolindophenol by either NADH or succinate were inhibited to a lesser extent. However, the activity of cytochrome oxidase was not affected by pyrrolnitrin. The extent of reduction of flavoproteins by NADH and succinate, measured at 465 - 510 nm, was unaltered; however, the reduction of cytochrome b, measured at 560 - 575 nm, was partially inhibited by pyrrolnitrin. The level of totally reduced cytochrome b was restored with antimycin A. We, therefore, concluded that the primary site of action of this antifungal antibiotic is to block electron transfer between the flavoprotein of the NADH-dehydrogenase and cytochrome b segment of the respiratory chain of M. gypseum.

  5. Respiratory Chain of a Pathogenic Fungus, Microsporum gypseum: Effect of the Antifungal Agent Pyrrolnitrin

    PubMed Central

    Wong, David T.; Horng, Jong-Sin; Gordee, Robert S.

    1971-01-01

    Pyrrolnitrin has been reported to inhibit Bacillus megaterium primarily by forming complexes with phospholipids and to block electron transfer of Saccharomyces cerevisiae between succinate or reduced nicotinamide adenine dinucleotide (NADH) and coenzyme Q. We found that pyrrolnitrin inhibited respiration of conidia of Microsporum gypseum. In mitochondrial preparations, pyrrolnitrin strongly inhibited respiration and the rotenone-sensitive NADH-cytochrome c reductase. The rotenone-insensitive NADH-cytochrome c reductase, the succinate-cytochrome c reductase, and the reduction of dichlorophenolindophenol by either NADH or succinate were inhibited to a lesser extent. However, the activity of cytochrome oxidase was not affected by pyrrolnitrin. The extent of reduction of flavoproteins by NADH and succinate, measured at 465 - 510 nm, was unaltered; however, the reduction of cytochrome b, measured at 560 - 575 nm, was partially inhibited by pyrrolnitrin. The level of totally reduced cytochrome b was restored with antimycin A. We, therefore, concluded that the primary site of action of this antifungal antibiotic is to block electron transfer between the flavoprotein of the NADH-dehydrogenase and cytochrome b segment of the respiratory chain of M. gypseum. PMID:4323963

  6. Synthesis and Biological Evaluation of New Eugenol Mannich Bases as Promising Antifungal Agents.

    PubMed

    Abrão, Pedro Henrique O; Pizi, Rafael B; de Souza, Thiago B; Silva, Naiara C; Fregnan, Antonio M; Silva, Fernanda N; Coelho, Luiz Felipe L; Malaquias, Luiz Cosme C; Dias, Amanda Latercia T; Dias, Danielle F; Veloso, Marcia P; Carvalho, Diogo T

    2015-10-01

    New Mannich base-type eugenol derivatives were synthesized and evaluated for their anticandidal activity using a broth microdilution assay. Among the synthesized compounds, 4-allyl-2-methoxy-6-(morpholin-4-ylmethyl) phenyl benzoate (7) and 4-{5-allyl-2-[(4-chlorobenzoyl)oxy]-3-methoxybenzyl}morpholin-4-ium chloride (8) were found to be the most effective antifungal compounds with low IC50 values, some of them well below those of reference drug fluconazole. The most significant IC50 values were those of 7 against C. glabrata (1.23 μm), C. albicans and C. krusei (both 0.63 μm). Additionally, the synthesized compounds were evaluated for their in vitro cytotoxic effects on human mononuclear cells. As result, the cytotoxic activity of eugenol in eukaryotic cells decreased with the introduction of the morpholinyl group. Given these findings, we point out compounds 7 and 8 as the most promising derivatives because they showed potency values greater than those of eugenol and fluconazole and they also presented high selectivity indexes.

  7. Identification and evaluation of novel acetolactate synthase inhibitors as antifungal agents.

    PubMed

    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; Ryder, Neil S; Hoepfner, Dominic

    2013-05-01

    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.

  8. Temperature affects the susceptibility of Cryptococcus neoformans biofilms to antifungal agents.

    PubMed

    Pettit, Robin K; Repp, Kimberly K; Hazen, Kevin C

    2010-03-01

    The fungal opportunist Cryptococcus neoformans forms biofilms in vitro and in vivo. C. neoformans has an unusual ability to grow over a wide range of temperatures, and is one of only two species in the genus able to grow at 37 degrees C. The optimum growth temperature in the laboratory is 30 degrees C, but Clinical and Laboratory Standards Institute (CLSI) planktonic susceptibility testing is performed at 35 degrees C. We investigated whether these growth temperatures affected C. neoformans biofilm formation and drug resistance. Biofilms of 30 strains of C. neoformans were grown at 30 degrees C or 35 degrees C, and antifungal susceptibilities evaluated at 30 degrees C or 35 degrees C using minimum biofilm eradication endpoints. At 35 degrees C, biofilms from 40% of the strains were more susceptible to flucytosine, 30% were more susceptible to nystatin, 27% were more susceptible to amphotericin, and 20% were more susceptible to fluconazole, as compared to 30 degrees C. The reverse, that is an increased susceptibility at 30 degrees C, only occurred with a single strain using nystatin or fluconazole. For the remaining strains, biofilm susceptibility was equivalent at the two temperatures. Biofilm colony forming units (CFU)s, as measured indirectly by 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction, were greater at 35 degrees C than at 30 degrees C for the majority of the strains. Thus, growth temperature does affect C. neoformans biofilm properties, but factors other than relative biofilm CFUs/ml must be involved in the increased drug susceptibility at 35 degrees C.

  9. Crystal structure of cytochrome P450 14α-sterol demethylase (CYP51) from Mycobacterium tuberculosis in complex with azole inhibitors

    PubMed Central

    Podust, Larissa M.; Poulos, Thomas L.; Waterman, Michael R.

    2001-01-01

    Cytochrome P450 14α-sterol demethylases (CYP51) are essential enzymes in sterol biosynthesis in eukaryotes. CYP51 removes the 14α-methyl group from sterol precursors such as lanosterol, obtusifoliol, dihydrolanosterol, and 24(28)-methylene-24,25-dihydrolanosterol. Inhibitors of CYP51 include triazole antifungal agents fluconazole and itraconazole, drugs used in treatment of topical and systemic mycoses. The 2.1- and 2.2-Å crystal structures reported here for 4-phenylimidazole- and fluconazole-bound CYP51 from Mycobacterium tuberculosis (MTCYP51) are the first structures of an authentic P450 drug target. MTCYP51 exhibits the P450 fold with the exception of two striking differences—a bent I helix and an open conformation of BC loop—that define an active site-access channel running along the heme plane perpendicular to the direction observed for the substrate entry in P450BM3. Although a channel analogous to that in P450BM3 is evident also in MTCYP51, it is not open at the surface. The presence of two different channels, with one being open to the surface, suggests the possibility of conformationally regulated substrate-in/product-out openings in CYP51. Mapping mutations identified in Candida albicans azole-resistant isolates indicates that azole resistance in fungi develops in protein regions involved in orchestrating passage of CYP51 through different conformational stages along the catalytic cycle rather than in residues directly contacting fluconazole. These new structures provide a basis for rational design of new, more efficacious antifungal agents as well as insight into the molecular mechanism of P450 catalysis. PMID:11248033

  10. The AUR1 gene in Saccharomyces cerevisiae encodes dominant resistance to the antifungal agent aureobasidin A (LY295337).

    PubMed Central

    Heidler, S A; Radding, J A

    1995-01-01

    Aureobasidin A (LY295337) is a cyclic depsipeptide antifungal agent with activity against Candida spp. The mechanism of action of LY295337 remains unknown. LY295337 also shows activity against the yeast Saccharomyces cerevisiae. Generation of a mutant of S. cerevisiae resistant to LY295337 is reported. Resistance was found to reside in a dominant mutation of a single gene which has been named AUR1 (aureobasidin resistance). This gene was cloned and sequenced. A search for homologous sequences in GenBank and by BLAST did not elucidate the function of this gene, although sequence homology too an open reading frame from the Saccharomyces genome sequencing project and several other adjacent loci was noted. Deletion of aur1 was accomplished in a diploid S. cerevisiae strain. Subsequent sporulation and dissection of the aur1/aur1 delta diploid resulted in tetrads demonstrating 2:2 segregation of viable and nonviable spores, indicating that deletion of aur1 is lethal. As LY295337 is fungicidal and deletion of aur1 is lethal, aur1 represents a potential candidate for the target of LY295337. PMID:8593016

  11. Morphological Effect of the New Antifungal Agent ME1111 on Hyphal Growth of Trichophyton mentagrophytes, Determined by Scanning and Transmission Electron Microscopy

    PubMed Central

    Takahata, Sho; Abe, Shigeru

    2016-01-01

    ABSTRACT The effects of ME1111, a novel antifungal agent, on the hyphal morphology and ultrastructure of Trichophyton mentagrophytes were investigated by using scanning and transmission electron microscopy. Structural changes, such as pit formation and/or depression of the cell surface, and degeneration of intracellular organelles and plasmolysis were observed after treatment with ME1111. Our results suggest that the inhibition of energy production by ME1111 affects the integrity and function of cellular membranes, leading to fungal cell death. PMID:27799213

  12. Frequency of Cutaneous Fungal Infections and Azole Resistance of the Isolates in Patients with Diabetes Mellitus

    PubMed Central

    Raiesi, Omid; Siavash, Mansour; Mohammadi, Faezeh; Chabavizadeh, Javaher; Mahaki, Behzad; Maherolnaghsh, Mehrnoush; Dehghan, Parvin

    2017-01-01

    Background: Diabetic patients are more susceptible to cutaneous fungal infections. The higher blood sugar levels cause increasing the cutaneous fungal infections in these patients. The main objective of this study was to find the frequency of fungal infections among cutaneous lesions of diabetic patients and to investigate azole antifungal agent susceptibility of the isolates. Materials and Methods: In this study, type 1diabetes (n = 78) and type 2 diabetes (n = 44) comprised 47 cases (38.5%) with diabetic foot ulcers and 75 cases (61.5%) with skin and nail lesions were studied. Fungal infection was confirmed by direct examination and culture methods. Antifungal susceptibility testing by broth microdilution method was performed according to the CLSI M27-A and M38-A references. Results: Out of 122 diabetic patients, thirty (24.5%) were affected with fungal infections. Frequency of fungal infection was 19.1% in patients with diabetic foot ulcer and 28% of patients with skin and nail lesions. Candida albicans and Aspergillus flavus were the most common species isolated from thirty patients with fungal infection, respectively. Susceptibility testing carried out on 18 representative isolates (13 C. albicans, five C. glabrata) revealed that 12 isolates (10 C. albicans and two C. glabrata isolates) (66.6%) were resistant (minimum inhibitory concentration [MIC] ≥64 mg/ml) to fluconazole (FCZ). Likewise, eight isolates (80%) of Aspergillus spp. were resistant (MIC ≥4 mg/ml), to itraconazole. Conclusion: Our finding expands current knowledge about the frequency of fungal infections in diabetic patients. We noted the high prevalence of FCZ-resistant Candida spp., particularly in diabetic foot ulcers. More attention is important in diabetic centers about this neglected issue. PMID:28626746

  13. Frequency of Cutaneous Fungal Infections and Azole Resistance of the Isolates in Patients with Diabetes Mellitus.

    PubMed

    Raiesi, Omid; Siavash, Mansour; Mohammadi, Faezeh; Chabavizadeh, Javaher; Mahaki, Behzad; Maherolnaghsh, Mehrnoush; Dehghan, Parvin

    2017-01-01

    Diabetic patients are more susceptible to cutaneous fungal infections. The higher blood sugar levels cause increasing the cutaneous fungal infections in these patients. The main objective of this study was to find the frequency of fungal infections among cutaneous lesions of diabetic patients and to investigate azole antifungal agent susceptibility of the isolates. In this study, type 1diabetes (n = 78) and type 2 diabetes (n = 44) comprised 47 cases (38.5%) with diabetic foot ulcers and 75 cases (61.5%) with skin and nail lesions were studied. Fungal infection was confirmed by direct examination and culture methods. Antifungal susceptibility testing by broth microdilution method was performed according to the CLSI M27-A and M38-A references. Out of 122 diabetic patients, thirty (24.5%) were affected with fungal infections. Frequency of fungal infection was 19.1% in patients with diabetic foot ulcer and 28% of patients with skin and nail lesions. Candida albicans and Aspergillus flavus were the most common species isolated from thirty patients with fungal infection, respectively. Susceptibility testing carried out on 18 representative isolates (13 C. albicans, five C. glabrata) revealed that 12 isolates (10 C. albicans and two C. glabrata isolates) (66.6%) were resistant (minimum inhibitory concentration [MIC] ≥64 mg/ml) to fluconazole (FCZ). Likewise, eight isolates (80%) of Aspergillus spp. were resistant (MIC ≥4 mg/ml), to itraconazole. Our finding expands current knowledge about the frequency of fungal infections in diabetic patients. We noted the high prevalence of FCZ-resistant Candida spp., particularly in diabetic foot ulcers. More attention is important in diabetic centers about this neglected issue.

  14. Antifungal polypeptides

    DOEpatents

    Altier, Daniel J [Waukee, IA; Ellanskaya, Irina [Kyiv, UA; Ellanskaya, legal representative, Natalia; Gilliam, Jacob T [Norwalk, IA; Hunter-Cevera, Jennie [Elliott City, MD; Presnail, James K [Avondale, PA; Schepers, Eric [Port Deposit, MD; Simmons, Carl R [Des Moines, IA; Torok, Tamas [Richmond, CA; Yalpani, Nasser [Johnston, IA

    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.

  15. Flucytosine Antagonism of Azole Activity versus Candida glabrata: Role of Transcription Factor Pdr1 and Multidrug Transporter Cdr1

    PubMed Central

    Steier, Zoë; Vermitsky, John-Paul; Toner, Geoffrey; Gygax, Scott E.; Edlind, Thomas

    2013-01-01

    Infections with the opportunistic yeast Candida glabrata have increased dramatically in recent years. Antifungal therapy of yeast infections commonly employs azoles, such as fluconazole (FLC), but C. glabrata frequently develops resistance to these inhibitors of ergosterol biosynthesis. The pyrimidine analog flucytosine (5-fluorocytosine [5FC]) is highly active versus C. glabrata but is now rarely used clinically due to similar concerns over resistance and, a related concern, the toxicity associated with high doses used to counter resistance. Azole-5FC combination therapy would potentially address these concerns; however, previous studies suggest that 5FC may antagonize azole activity versus C. glabrata. Here, we report that 5FC at subinhibitory concentrations antagonized the activity of FLC 4- to 16-fold versus 8 of 8 C. glabrata isolates tested. 5FC antagonized the activity of other azoles similarly but had only indifferent effects in combination with unrelated antifungals. Since azole resistance in C. glabrata results from transcription factor Pdr1-dependent upregulation of the multidrug transporter gene CDR1, we reasoned that 5FC antagonism might be similarly mediated. Indeed, 5FC-FLC antagonism was abrogated in pdr1Δ and cdr1Δ strains. In further support of this hypothesis, 5FC exposure induced CDR1 expression 6-fold, and this upregulation was Pdr1 dependent. In contrast to azoles, 5FC is not a Cdr1 substrate and so its activation of Pdr1 was unexpected. We observed, however, that 5FC exposure readily induced petite mutants, which exhibit Pdr1-dependent CDR1 upregulation. Thus, mitochondrial dysfunction resulting in Pdr1 activation is the likely basis for 5FC antagonism of azole activity versus C. glabrata. PMID:23979762

  16. Antifungal nanoparticles and surfaces.

    PubMed

    Paulo, Cristiana S O; Vidal, Maria; Ferreira, Lino S

    2010-10-11

    Nosocomial fungal infections, an increasing healthcare concern worldwide, are often associated with medical devices. We have developed antifungal nanoparticle conjugates that can act in suspension or attach to a surface, efficiently killing fungi. For that purpose, we immobilized covalently amphotericin B (AmB), a potent antifungal agent approved by the FDA, widely used in clinical practice and effective against a large spectrum of fungi, into silica nanoparticles. These antifungal nanoparticle conjugates are fungicidal against several strains of Candida sp., mainly by contact. In addition, they can be reused up to 5 cycles without losing their activity. Our results show that the antifungal nanoparticle conjugates are more fungistatic and fungicidal than 10 nm colloidal silver. The antifungal activity of the antifungal nanoparticle conjugates is maintained when they are immobilized on a surface using a chemical adhesive formed by polydopamine. The antifungal nanocoatings have no hemolytic or cytotoxic effect against red blood cells and blood mononuclear cells, respectively. Surfaces coated with these antifungal nanoparticle conjugates can be very useful to render medical devices with antifungal properties.

  17. Search for antibacterial and antifungal agents from selected Indian medicinal plants.

    PubMed

    Kumar, V Prashanth; Chauhan, Neelam S; Padh, Harish; Rajani, M

    2006-09-19

    A series of 61 Indian medicinal plants belonging to 33 different families used in various infectious disorders, were screened for their antimicrobial properties. Screening was carried out at 1000 and 500 microg/ml concentrations by agar dilution method against Bacillus cereus var mycoides, Bacillus pumilus, Bacillus subtilis, Bordetella bronchiseptica, Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Streptococcus faecalis, Candida albicans, Aspergillus niger and Saccharomyces cerevisiae. Twenty-eight plant extracts showed activity against at least one of the test organisms used in the screening. On the basis of the results obtained, we conclude that the crude extracts of Dorema ammoniacum, Sphaeranthus indicus, Dracaena cinnabari, Mallotus philippinensis, Jatropha gossypifolia, Aristolochia indica, Lantana camara, Nardostachys jatamansi, Randia dumetorum and Cassia fistula exhibited significant antimicrobial activity and properties that support folkloric use in the treatment of some diseases as broad-spectrum antimicrobial agents. This probably explains the use of these plants by the indigenous people against a number of infections.

  18. Novel macrocyclic molecules based on 12a-N substituted 16-membered azalides and azalactams as potential antifungal agents.

    PubMed

    Wang, Xiaolei; Zhang, Shun; Pang, Yanlong; Yuan, Huihui; Liang, Xiaomei; Zhang, Jianjun; Wang, Daoquan; Wang, Mingan; Dong, Yanhong

    2014-02-12

    Novel macrocyclic molecules comprising sulfonyl and acyl moiety at the position N-12a of 16-membered azalides (6a-n) and azalactams (10a-r) scaffold were synthesized from cyclododecanone 1 as starting material via 5 steps and 4 steps, respectively. The antifungal activity of these compounds against Sclerotinia sclerotiorum, Pyricularia oryzae, Botrytis cinerea, Rhizoctonia solani and Phytophthora capsici were evaluated and found that compounds possessing α-exomethylene (6c, 6d, 6e and 6g) showed antifungal activity comparable to commercial fungicide Chlorothalonil against P. oryzae and compounds possessing p-chlorobenzoyl exhibited enhanced antifungal activity than those with other substituents against S. sclerotiorum, P. oryzae, and B. cinerea. These findings suggested that the α-exomethylene and p-chlorobenzoyl may be two potential pharmacological active groups with antifungal activities.

  19. 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

  20. 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

  1. 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.

  2. Functional expression of P-glycoprotein in Saccharomyces cerevisiae confers cellular resistance to the immunosuppressive and antifungal agent FK520.

    PubMed Central

    Raymond, M; Ruetz, S; Thomas, D Y; Gros, P

    1994-01-01

    We have recently reported that expression in yeast cells of P-glycoprotein (P-gp) encoded by the mouse multidrug resistance mdr3 gene (Mdr3) can complement a null ste6 mutation (M. Raymond, P. Gros, M. Whiteway, and D. Y. Thomas, Science 256:232-234, 1992). Here we show that Mdr3 behaves as a fully functional drug transporter in this heterologous expression system. Photolabelling experiments indicate that Mdr3 synthesized in yeast cells binds the drug analog [125I]iodoaryl azidoprazosin, this binding being competed for by vinblastine and tetraphenylphosphonium bromide, two known multidrug resistance drugs. Spheroplasts expressing wild-type Mdr3 (Ser-939) exhibit an ATP-dependent and verapamil-sensitive decreased accumulation of [3H]vinblastine as compared with spheroplasts expressing a mutant form of Mdr3 with impaired transport activity (Phe-939). Expression of Mdr3 in yeast cells can confer resistance to growth inhibition by the antifungal and immunosuppressive agent FK520, suggesting that this compound is a substrate for P-gp in yeast cells. Replacement of Ser-939 in Mdr3 by a series of amino acid substitutions is shown to modulate both the level of cellular resistance to FK520 and the mating efficiency of yeast mdr3 transformants. The effects of these mutations on the function of Mdr3 in yeast cells are similar to those observed in mammalian cells with respect to drug resistance and transport, indicating that transport of a-factor and FK520 in yeast cells is mechanistically similar to drug transport in mammalian cells. The ability of P-gp to confer cellular resistance to FK520 in yeast cells establishes a dominant phenotype that can be assayed for the positive selection of intragenic revertants of P-gp inactive mutants, an important tool for the structure-function analysis of mammalian P-gp in yeast cells. Images PMID:7505392

  3. Antifungal agents. Part 4: Synthesis and antifungal activities of novel indole[1,2-c]-1,2,4-benzotriazine derivatives against phytopathogenic fungi in vitro.

    PubMed

    Xu, Hui; Fan, Ling-Ling

    2011-01-01

    A series of novel indole[1,2-c]-1,2,4-benzotriazine derivatives were obtained by a modified Sandmeyer reaction in the presence of tert-butylnitrite (t-BuONO). As compared with hymexazol, a commercially available agricultural fungicide, at the concentration of 50 μg/mL, two indole[1,2-c]-1,2,4-benzotriazines, 5h and 5k, exhibited the more promising and pronounced antifungal activities in vitro against five phytopathogenic fungi. It clearly demonstrated that introduction of appropriate substituents on the indolyl ring of indole[1,2-c]-1,2,4-benzotriazine (5a) would lead to the more potent derivatives.

  4. A novel antifungal agent with broad spectrum: 1-(4-biphenylyl)-3-(1H-imidazol-1-yl)-1-propanone.

    PubMed

    Roman, Gheorghe; Mareş, Mihai; Năstasă, Valentin

    2013-02-01

    A series of (1-substituted aryl)-3-(1H-imidazol-1-yl)-1-propanones was synthesized through the N-alkylation of imidazole with 3-dimethylamino-1-(substituted aryl)-1-propanone hydrochlorides (ketonic Mannich bases). A second series of N(1) -substituted imidazoles was obtained by the reduction of the carbonyl function of the imidazole-ketones in the previous series by means of NaBH(4) . All of the compounds were evaluated for antifungal activity against 16 strains of Candida, and 3-(1H-imidazol-1-yl)-1-(4-biphenylyl)-1-propanone emerged as a broad-spectrum antifungal agent. Several 3-(1H-imidazol-1-yl)-1-(2'-(substituted benzyl)oxyphenyl)-1-propanones were also active towards Candida kefyr. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Slime production and proteinase activity of Candida species isolated from blood samples and the comparison of these activities with minimum inhibitory concentration values of antifungal agents.

    PubMed

    Ozkan, Semiha; Kaynak, Fatma; Kalkanci, Ayse; Abbasoglu, Ufuk; Kustimur, Semra

    2005-05-01

    Slime and proteinase activity of 54 strains consisting of 19 Candida parapsilosis and 35 C. albicans strains isolated from blood samples were investigated in this study. Ketoconazole, amphothericin B, and fluconazole susceptibility of Candida species were compared with slime production and proteinase activity of these species. For both Candida species, no correlation was detected between the slime activity and minimum inhibitory concentration (MIC) values of the three antifungal agents. For both Candida species no correlation was detected between the proteinase activity and the MIC values of amphothericin B, and fluconazole however, statistically significant difference, was determined between the proteinase activity and MIC values of ketoconazole (p = 0.007). Slime production was determined by using modified Christensen macrotube method and proteinase activity was measured by the method of Staib. Antifungal susceptibility was determined through the guidelines of National Committee for Laboratory Standards (NCCLS M27-A).

  6. Effects of azole treatments on the physical properties of Candida albicans plasma membrane: a spin probe EPR study.

    PubMed

    Sgherri, Cristina; Porta, Amalia; Castellano, Sabrina; Pinzino, Calogero; Quartacci, Mike F; Calucci, Lucia

    2014-01-01

    EPR spectroscopy was applied to investigate the effects of the treatment of Candida albicans cells with fluconazole (FLC) and two newly synthesized azoles (CPA18 and CPA109), in a concentration not altering yeast morphology, on the lipid organization and dynamics of the plasma membrane. Measurements were performed in the temperature range between 0°C and 40°C using 5-doxyl- (5-DSA) and 16-doxyl- (16-DSA) stearic acids as spin probes. 5-DSA spectra were typical of lipids in a highly ordered environment, whereas 16-DSA spectra consisted of two comparable components, one corresponding to a fluid bulk lipid domain in the membrane and the other to highly ordered and motionally restricted lipids interacting with integral membrane proteins. A line shape analysis allowed the relative proportion and the orientational order and dynamic parameters of the spin probes in the different environments to be determined. Smaller order parameters, corresponding to a looser lipid packing, were found for the treated samples with respect to the control one in the region close to the membrane surface probed by 5-DSA. On the other hand, data on 16-DSA indicated that azole treatments hamper the formation of ordered lipid domains hosting integral proteins and/or lead to a decrease in integral protein content in the membrane. The observed effects are mainly ascribable to the inhibition of ergosterol biosynthesis by the antifungal agents, although a direct interaction of the CPA compounds with the membrane bilayer in the region close to the lipid polar head groups cannot be excluded. © 2013.

  7. Combination Effects of (Tri)Azole Fungicides on Hormone Production and Xenobiotic Metabolism in a Human Placental Cell Line

    PubMed Central

    Rieke, Svenja; Koehn, Sophie; Hirsch-Ernst, Karen; Pfeil, Rudolf; Kneuer, Carsten; Marx-Stoelting, Philip

    2014-01-01

    Consumers are exposed to multiple residues of different pesticides via the diet. Therefore, EU legislation for pesticides requires the evaluation of single active substances as well as the consideration of combination effects. Hence the analysis of combined effects of substances in a broad dose range represents a key challenge to current experimental and regulatory toxicology. Here we report evidence for additive effects for (tri)azole fungicides, a widely used group of antifungal agents, in the human placental cell line Jeg-3. In addition to the triazoles cyproconazole, epoxiconazole, flusilazole and tebuconazole and the azole fungicide prochloraz also pesticides from other chemical classes assumed to act via different modes of action (i.e., the organophosphate chlorpyrifos and the triazinylsulfonylurea herbicide triflusulfuron-methyl) were investigated. Endpoints analysed include synthesis of steroid hormone production (progesterone and estradiol) and gene expression of steroidogenic and non-steroidogenic cytochrome-P-450 (CYP) enzymes. For the triazoles and prochloraz, a dose dependent inhibition of progesterone production was observed and additive effects could be confirmed for several combinations of these substances in vitro. The non-triazoles chlorpyrifos and triflusulfuron-methyl did not affect this endpoint and, in line with this finding, no additivity was observed when these substances were applied in mixtures with prochloraz. While prochloraz slightly increased aromatase expression and estradiol production and triflusulfuron-methyl decreased estradiol production, none of the other substances had effects on the expression levels of steroidogenic CYP-enzymes in Jeg-3 cells. For some triazoles, prochloraz and chlorpyrifos a significant induction of CYP1A1 mRNA expression and potential combination effects for this endpoint were observed. Inhibition of CYP1A1 mRNA induction by the AhR inhibitor CH223191 indicated AhR receptor dependence of this effect. PMID

  8. Combination effects of (tri)azole fungicides on hormone production and xenobiotic metabolism in a human placental cell line.

    PubMed

    Rieke, Svenja; Koehn, Sophie; Hirsch-Ernst, Karen; Pfeil, Rudolf; Kneuer, Carsten; Marx-Stoelting, Philip

    2014-09-17

    Consumers are exposed to multiple residues of different pesticides via the diet. Therefore, EU legislation for pesticides requires the evaluation of single active substances as well as the consideration of combination effects. Hence the analysis of combined effects of substances in a broad dose range represents a key challenge to current experimental and regulatory toxicology. Here we report evidence for additive effects for (tri)azole fungicides, a widely used group of antifungal agents, in the human placental cell line Jeg-3. In addition to the triazoles cyproconazole, epoxiconazole, flusilazole and tebuconazole and the azole fungicide prochloraz also pesticides from other chemical classes assumed to act via different modes of action (i.e., the organophosphate chlorpyrifos and the triazinylsulfonylurea herbicide triflusulfuron-methyl) were investigated. Endpoints analysed include synthesis of steroid hormone production (progesterone and estradiol) and gene expression of steroidogenic and non-steroidogenic cytochrome-P-450 (CYP) enzymes. For the triazoles and prochloraz, a dose dependent inhibition of progesterone production was observed and additive effects could be confirmed for several combinations of these substances in vitro. The non-triazoles chlorpyrifos and triflusulfuron-methyl did not affect this endpoint and, in line with this finding, no additivity was observed when these substances were applied in mixtures with prochloraz. While prochloraz slightly increased aromatase expression and estradiol production and triflusulfuron-methyl decreased estradiol production, none of the other substances had effects on the expression levels of steroidogenic CYP-enzymes in Jeg-3 cells. For some triazoles, prochloraz and chlorpyrifos a significant induction of CYP1A1 mRNA expression and potential combination effects for this endpoint were observed. Inhibition of CYP1A1 mRNA induction by the AhR inhibitor CH223191 indicated AhR receptor dependence this effect.

  9. In vitro antifungal susceptibility of Malassezia pachydermatis strains isolated from dogs with chronic and acute otitis externa.

    PubMed

    Chiavassa, E; Tizzani, P; Peano, A

    2014-10-01

    Malassezia pachydermatis is a yeast that is frequently involved as a secondary/perpetuating factor in canine otitis externa. Topical therapies with different antifungal agents, mainly azole compounds, are generally successful in controlling the yeast overgrowth, but treatment failure and rapid recurrences are common. This study compared the in vitro antifungal susceptibility of M. pachydermatis isolates obtained from chronic and acute cases of otitis externa. The aim was to assess the possible onset of resistance mechanisms in isolates involved in long-lasting episodes with poor response to treatment. We evaluated the in vitro susceptibility to miconazole (MCZ) and clotrimazole (CTZ) of 42 isolates of M. pachydermatis obtained from dogs with chronic (group A, n = 25) and acute otitis (group B, n = 17), using a modified CLSI M27-A3 microdilution method. All isolates were inhibited by the antifungal agents employed, but Malassezia isolates from group A were significantly associated with higher minimum inhibitory concentration (MIC) values for both agents (Median MIC values: MCZ group A 2 µg/ml, group B 1 µg/ml; CTZ group A 8 µg/ml, group B 4 µg/ml). These findings prove that these isolates had a reduced in vitro susceptibility to the antifungal agents tested. However, it is unlikely that this could have any influence on the outcome of a topical treatment. Indeed, marketed products include concentrations of the tested agents that largely exceed even the highest MICs found in this study (in most cases at least 1,000 × the MIC, or greater). In conclusion, this study suggests that isolates of M. pachydermatis involved in chronic cases of canine external otitis and exposed to repeated antifungal treatments are unlikely to develop mechanisms of resistance of clinical relevance.

  10. Discontinuation of echinocandin and azole treatments led to the disappearance of an FKS alteration but not azole resistance during clonal Candida glabrata persistent candidaemia.

    PubMed

    Imbert, S; Castain, L; Pons, A; Jacob, S; Meyer, I; Palous, M; Vezinet, C; Langeron, O; Hennequin, C; Monsel, A; Fekkar, A

    2016-10-01

    To give an indication of a fitness cost conferred by FKS mutation-associated echinocandin resistance in Candida glabrata during human infection. Six C. glabrata clinical strains sequentially isolated from blood and a hepatic abscess in a solid organ transplant recipient were analysed. The patient had received long-term azole and echinocandin therapy for invasive aspergillosis and persistent candidaemia. Minimal inhibitory concentrations were determined by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) broth microdilution method. Molecular mechanisms of antifungal resistance were determined by sequencing hot spots of the FKS. Strain relatedness was determined using a microsatellite-based typing method. Typing analysis revealed an identical microsatellite pattern for all isolates, supporting a close relation. The first C. glabrata isolate showed wild-type phenotype (i.e. susceptibility to echinocandins and low level of azole resistance). After voriconazole therapy, the C. glabrata quickly acquired pan-azole resistance. Later, echinocandin treatment led to the emergence of a FKS2 S663P alteration and echinocandin resistance. After disruption of both azole and echinocandin therapy in favour of liposomal amphotericin B, C. glabrata isolates regained full susceptibility to echinocandin and lost the FKS2 S663P alteration while nonetheless maintaining their pan-azole resistance. Our clinical report supports the potential existence of a fitness cost conferred by FKS mutation in C. glabrata, as disruption of treatment led to a rapid disappearance of the resistant clone. This suggests that a more restricted use and/or a discontinuous administration of echinocandins may limit the spread of clinical resistance to this class.

  11. Human mycoses and advances in antifungal therapy.

    PubMed

    Fromtling, R A

    2001-04-01

    The 11th Focus on Fungal Infections meeting was held in Washington, D.C., U.S.A., March 1416, 2001. At the conference, there were well-attended sessions that focused on the pathogenesis and therapy of fungal disease. This report focuses on new information on fungal incidence and pathogenesis as well as on the in vitro and clinical experience of established antifungal drugs (fluconazole, itraconazole, amphotericin B, liposomal formulations of amphotericin B, terbinafine) and the newer antifungal compounds approved for use (e.g., caspofungin) and in development (the new-generation azoles: voriconazole, posaconazole, ravuconazole, and the candins, micafungin and anidulafungin).

  12. 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.

  13. Efficacy of FK463, a New Lipopeptide Antifungal Agent, in Mouse Models of Disseminated Candidiasis and Aspergillosis

    PubMed Central

    Ikeda, Fumiaki; Wakai, Yoshimi; Matsumoto, Satoru; Maki, Katsuyuki; Watabe, Etsuko; Tawara, Shuichi; Goto, Toshio; Watanabe, Yuji; Matsumoto, Fumio; Kuwahara, Shogo

    2000-01-01

    The efficacy of intravenous injection of FK463, a novel water-soluble lipopeptide, was evaluated in mouse models of disseminated candidiasis and aspergillosis and was compared with those of fluconazole (FLCZ) and amphotericin B (AMPH-B). In the candidiasis model, FK463 significantly prolonged the survival of intravenously infected mice at doses of 0.125 mg/kg of body weight or higher. In disseminated candidiasis caused by Candida species, including FLCZ-resistant Candida albicans, FK463 exhibited an efficacy 1.4 to 18 times inferior to that of AMPH-B, with 50% effective doses (ED50s) ranging from 0.21 to 1.00 mg/kg and 0.06 to 0.26 mg/kg, respectively, and was much more active than FLCZ. The protective effect of FK463 was not obviously influenced by the fungal inoculum size, the starting time of the treatment, or the immunosuppressed status of the host. The reduction in efficacy was less than that observed with FLCZ or AMPH-B. The efficacy of FK463 was also evaluated in the disseminated candidiasis target organ assay and was compared with those of FLCZ and AMPH-B. Efficacies were evaluated on the basis of a comparison between the mean log10 CFU in kidneys in the groups treated with antifungal agents and that in control group. A single dose of FK463 at 0.5 mg/kg or higher significantly reduced the viable counts in kidneys compared with the numbers of yeast cells before treatment, and its efficacy was comparable to that of AMPH-B, while FLCZ at 4 mg/kg showed only a suppressive effect on the growth of C. albicans in the kidneys. In the disseminated aspergillosis model, FK463 given at doses of 0.5 mg/kg or higher significantly prolonged the survival of mice infected intravenously with Aspergillus fumigatus conidia. The efficacy of FK463 was about 2 times inferior to that of AMPH-B, with ED50s ranging from 0.25 to 0.50 mg/kg and 0.11 to 0.29 mg/kg, respectively. These results indicate that FK463 may be a potent parenterally administered therapeutic agent for

  14. 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

  15. Evaluation of antifungal activity of standardized extract of Salvia rhytidea Benth. (Lamiaceae) against various Candida isolates.

    PubMed

    Salari, S; Bakhshi, T; Sharififar, F; Naseri, A; Ghasemi Nejad Almani, P

    2016-12-01

    Salvia species have long been described in traditional medicine for various indications. Owing to the widespread use of this genus by ethnic populations, especially for various infections ranging from skin disease to gastrointestinal disorders, we were encouraged to determine whether Salvia rhytidea could be effective against fungal infections. Given the increased incidence of candidiasis in the past decade, limits on the use of antifungal drugs, emergence of azole-resistant Candida species and increased incidence of treatment failures, it is necessary to identify a novel agent with antifungal properties. Aim of the study was to evaluate the antifungal properties of S. rhytidea against various Candida isolates. In this study, at first rosmarinic acid content of plant extract was determined. A total of 96 Candida isolates were tested, including the following species: Candida albicans (n=42), Candida glabrata (n=16), Candida tropicalis (n=11), Candida krusei (n=9), Candida parapsilosis (n=9), Candida lusitaniae (n=7) and Candida guilliermondii (n=2). The in vitro antifungal activity of methanolic extracts of S. rhytidea Benth. was evaluated against Candida isolates and compared with that of the standard antifungal drug nystatin by using a broth microdilution method, according to CLSI. Phytochemical screening results showed that the methanolic extract of S. rhytidea Benth. was rich in flavonoids and tannins. The minimal inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values of S. rhytidea Benth. ranged from 3.125 to>100μg/ml and 6.25 to>100μg/ml respectively. The growth inhibition value displayed that C. tropicalis, C. krusei and C. albicans isolates were most susceptible to S. rhytidea. Findings show that S. rhytidea possesses an antifungal effect against Candida isolates. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  16. Susceptibility of clinically important dermatophytes against statins and different statin-antifungal combinations.

    PubMed

    Nyilasi, Ildikó; Kocsubé, Sándor; Krizsán, Krisztina; Galgóczy, László; Papp, Tamás; Pesti, Miklós; Nagy, Katalin; Vágvölgyi, Csaba

    2014-02-01

    The investigation of the antifungal activities of drugs whose primary activities are not related to their antimicrobial potential is in the current forefront of research. Statin compounds, which are routinely used as cholesterol-lowering drugs, may also exert direct antimicrobial effects. In this study, the in vitro antifungal activities of various statins (lovastatin, simvastatin, fluvastatin, atorvastatin, rosuvastatin and pravastatin) were examined against one isolate each of four dermatophyte species (Trichophyton mentagrophytes, Trichophyton rubrum, Microsporum canis and Microsporum gypseum). Basically, statins were effective in inhibiting all dermatophyte studied, but were particularly active against M. canis and T. mentagrophytes. Fluvastatin and simvastatin were active against all of the tested fungi causing a complete inhibition of their growth at very low concentrations (6.25-12.5 μg/ml). Lovastatin and rosuvastatin had inhibitory effects at higher concentrations (25-128 μg/ml), while atorvastatin and pravastatin proved the less effective. The in vitro interactions between statins and different antifungals (ketoconazole, itraconazole, fluconazole, amphotericin B, nystatin, griseofulvin, terbinafine and primycin) were also investigated using a standard chequerboard broth microdilution method. Synergetic interactions were observed in several cases, most of them were noticed when statins were combined with terbinafine and the different azoles. Some combinations were particularly active (ketoconazole-simvastatin or terbinafine-simvastatin), as they were found to exert synergistic effect against all of the investigated isolates. The other antifungals showed synergistic interactions with statins in only certain cases. These results suggest that statins exert substantial antifungal effects against dermatophyte fungi and they should be promising components in a combination therapy as they can act synergistically with a number of clinically used antifungal

  17. Head-to-Head Comparison of the Activities of Currently Available Antifungal Agents against 3,378 Spanish Clinical Isolates of Yeasts and Filamentous Fungi

    PubMed Central

    Cuenca-Estrella, Manuel; Gomez-Lopez, Alicia; Mellado, Emilia; Buitrago, Maria J.; Monzon, Araceli; Rodriguez-Tudela, Juan Luis

    2006-01-01

    We have compared the activities of posaconazole and other currently available antifungal agents against a collection of 3,378 clinical isolates of yeasts and filamentous fungi. A total of 1,997 clinical isolates of Candida spp., 359 of other yeast species, 697 strains of Aspergillus spp., and 325 nondermatophyte non-Aspergillus spp. were included. The average geometric means of the MICs of agents that were tested against Candida spp. were 0.23 μg/ml for amphotericin B, 0.29 μg/ml for flucytosine, 0.97 μg/ml for fluconazole, 0.07 μg/ml for itraconazole, 0.04 μg/ml for voriconazole, 0.15 μg/ml for caspofungin, and 0.03 μg/ml for posaconazole. Voriconazole and posaconazole were active in vitro against the majority of isolates, with resistance to fluconazole and itraconazole, and against Cryptococcus neoformans and other Basidiomycota yeasts. Posaconazole was the most active of antifungal agents tested against Aspergillus spp., with an average geometric mean of 0.10 μg/ml. It was active against Paecilomyces spp., Penicillium spp., Scedosporium apiospermum, and some black fungi, such as Alternaria spp. Multiresistant filamentous fungi, such as Scedosporium prolificans, Scopulariopsis brevicaulis, and Fusarium solani, were also resistant to voriconazole, caspofungin, and posaconazole. Amphotericin B and posaconazole were found to be active against most of the Mucorales strains tested. Posaconazole and currently available antifungal agents exhibit a potent activity in vitro against the majority of pathogenic fungal species. PMID:16495251

  18. 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

    2016-04-28

    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.

  19. Identification of genetic markers of resistance to echinocandins, azoles and 5-fluorocytosine in Candida glabrata by next-generation sequencing: a feasibility study.

    PubMed

    Biswas, C; Chen, S C-A; Halliday, C; Kennedy, K; Playford, E G; Marriott, D J; Slavin, M A; Sorrell, T C; Sintchenko, V

    2017-09-01

    Multi-antifungal drug resistance in Candida glabrata is increasing. We examined the feasibility of next-generation sequencing (NGS) to investigate the presence of antifungal drug resistance markers in C. glabrata. The antifungal susceptibility of 12 clinical isolates and one ATCC strain of C. glabrata was determined using the Sensititre YeastOne(®) YO10 assay. These included three isolate pairs where the second isolate of each pair had developed a rise in drug MICs. Single nucleotide polymorphisms (SNPs) in genes known to be linked to echinocandin, azole and 5-fluorocytosine resistance were analysed in all isolates through NGS. High-quality non-synonymous SNPs in antifungal resistance genes such as FKS1, FKS2, CgCDR1, CgPDR1 and FCY2 were identified. For two of three isolate pairs, there was a >60-fold rise in MICs to all echinocandins in the second isolate from each pair; one echinocandin-resistant isolate harboured a mutation in FKS1 (S629P) and the other in FKS2 (S663P). Of the third pair, both the 5-fluorocytosine-susceptible, and resistant isolates had a mutation in FCY2 (A237T). SNPs in CgPDR1 were found in pan-azole-resistant isolates. SNPs in other genes linked to azole resistance (CgCDR1, ERG9 and CgFLR1) were present in both azole-susceptible and azole-resistant isolates. SNPs were also identified in Candida adhesin genes EPA1, EPA6, PWP2 and PWP5 but their presence was not associated with higher drug MICs. Genome-wide analysis of antifungal resistance markers was feasible and simultaneously revealed mutation patterns of genes implicated in resistance to different antifungal drug classes. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  20. Aspergillus fumigatus in the cystic fibrosis lung: pros and cons of azole therapy.

    PubMed

    Burgel, Pierre-Régis; Paugam, André; Hubert, Dominique; Martin, Clémence

    2016-01-01

    Aspergillus fumigatus is the main fungus cultured in the airways of patients with cystic fibrosis (CF). Allergic bronchopulmonary aspergillosis occurs in ~10% of CF patients and is clearly associated with airway damage and lung function decline. The effects of A. fumigatus colonization in the absence of allergic bronchopulmonary aspergillosis are less well established. Retrospective clinical studies found associations of A. fumigatus-positive cultures with computed tomography scan abnormalities, greater risk of CF exacerbations and hospitalizations, and/or lung function decline. These findings were somewhat variable among studies and provided only circumstantial evidence for a role of A. fumigatus colonization in CF lung disease progression. The availability of a growing number of oral antifungal triazole drugs, together with the results of nonrandomized case series suggesting positive effects of azole therapies, makes it tempting to treat CF patients with these antifungal drugs. However, the only randomized controlled trial that has used itraconazole in CF patients showed no significant benefit. Because triazoles may have significant adverse effects and drug interactions, and because their prolonged use has been associated with the emergence of azole-resistant A. fumigatus isolates, it remains unclear whether or not CF patients benefit from azole therapy.

  1. Aspergillus fumigatus in the cystic fibrosis lung: pros and cons of azole therapy

    PubMed Central

    Burgel, Pierre-Régis; Paugam, André; Hubert, Dominique; Martin, Clémence

    2016-01-01

    Aspergillus fumigatus is the main fungus cultured in the airways of patients with cystic fibrosis (CF). Allergic bronchopulmonary aspergillosis occurs in ~10% of CF patients and is clearly associated with airway damage and lung function decline. The effects of A. fumigatus colonization in the absence of allergic bronchopulmonary aspergillosis are less well established. Retrospective clinical studies found associations of A. fumigatus-positive cultures with computed tomography scan abnormalities, greater risk of CF exacerbations and hospitalizations, and/or lung function decline. These findings were somewhat variable among studies and provided only circumstantial evidence for a role of A. fumigatus colonization in CF lung disease progression. The availability of a growing number of oral antifungal triazole drugs, together with the results of nonrandomized case series suggesting positive effects of azole therapies, makes it tempting to treat CF patients with these antifungal drugs. However, the only randomized controlled trial that has used itraconazole in CF patients showed no significant benefit. Because triazoles may have significant adverse effects and drug interactions, and because their prolonged use has been associated with the emergence of azole-resistant A. fumigatus isolates, it remains unclear whether or not CF patients benefit from azole therapy. PMID:27703383

  2. Inhibitors of the Glyoxylate Cycle Enzyme ICL1 in Candida albicans for Potential Use as Antifungal Agents

    PubMed Central

    Cheah, Hong-Leong; Lim, Vuanghao; Sandai, Doblin

    2014-01-01

    Candida albicans is an opportunistic pathogen that causes candidiasis in humans. In recent years, metabolic pathways in C. albicans have been explored as potential antifungal targets to treat candidiasis. The glyoxylate cycle, which enables C. albicans to survive in nutrient-limited host niches and its. Key enzymes (e.g., isocitrate lyase (ICL1), are particularly attractive antifungal targets for C. albicans. In this study, we used a new screening approach that better reflects the physiological environment that C. albicans cells experience during infection to identify potential inhibitors of ICL. Three compounds (caffeic acid (CAFF), rosmarinic acid (ROS), and apigenin (API)) were found to have antifungal activity against C. albicans when tested under glucose-depleted conditions. We further confirmed the inhibitory potential of these compounds against ICL using the ICL enzyme assay. Lastly, we assessed the bioavailability and toxicity of these compounds using Lipinski's rule-of-five and ADMET analysis. PMID:24781056

  3. Synergistic anticandidal activity of pure polyphenol curcumin I in combination with azoles and polyenes generates reactive oxygen species leading to apoptosis.

    PubMed

    Sharma, Monika; Manoharlal, Raman; Negi, Arvind Singh; Prasad, Rajendra

    2010-08-01

    We have shown previously that pure polyphenol curcumin I (CUR-I) shows antifungal activity against Candida species. By employing the chequerboard method, filter disc and time-kill assays, in the present study we demonstrate that CUR-I at non-antifungal concentration interacts synergistically with azoles and polyenes. For this, pure polyphenol CUR-I was tested for synergy with five azole and two polyene drugs - fluconazole (FLC), miconazole, ketoconazole (KTC), itraconazole (ITR), voriconazole (VRC), nystatin (NYS) and amphotericin B (AMB) - against 21 clinical isolates of Candida albicans with reduced antifungal sensitivity, as well as a drug-sensitive laboratory strain. Notably, there was a 10-35-fold drop in the MIC(80) values of the drugs when CUR-I was used in combination with azoles and polyenes, with fractional inhibitory concentration index (FICI) values ranging between 0.09 and 0.5. Interestingly, the synergistic effect of CUR-I with FLC and AMB was associated with the accumulation of reactive oxygen species, which could be reversed by the addition of an antioxidant such as ascorbic acid. Furthermore, the combination of CUR-I and FLC/AMB triggered apoptosis that could also be reversed by ascorbic acid. We provide the first evidence that pure CUR-I in combination with azoles and polyenes represents a novel therapeutic strategy to improve the activity of common antifungals.

  4. 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.

  5. Susceptibility to antifungal agents and enzymatic activity of Candida haemulonii and Cutaneotrichosporon dermatis isolated from soft corals on the Brazilian reefs.

    PubMed

    Pagani, Danielle M; Heidrich, Daiane; Paulino, Gustavo V B; de Oliveira Alves, Karine; Dalbem, Paula T; de Oliveira, Caroline F; Andrade, Zélia M M; Silva, Carolini; Correia, Monica D; Scroferneker, Maria Lúcia; Valente, Patricia; Landell, Melissa Fontes

    2016-12-01

    Candida is a common fungus with the capacity to cause infections in humans. However, most studies have concentrated on clinical isolates and little is known about the identity, ecology and drug resistance of free living species/strains. Here, we isolate eight strains of Candida haemulonii and four strains of Cutaneotrichosporon dermatis from three marine cnidarian zoanthids species (Palythoa caribaeorum, Palythoa variabilis and Zoanthus sociatus) collected from Brazilian coral reefs. Strains were identified by sequencing of the D1/D2 domain LSU rDNA and ITS region. We tested these environmental isolates for their capacity to grow in media with increasing concentration of NaCl, capacity to grow in different temperatures, enzymatic activity and antifungal susceptibility. For C. haemulonii, all strains strongly produced gelatinase, esterase and albuminase and were either able to express lipase, phospholipase and keratinase, but not express urease and DNase. The strains were able to grow at 37 °C, but not at 39 °C, and except for LMS 40, all of them could grow in a 10 % NaCl medium. All isolates were resistant to all antifungals tested, with exception for ketoconazole and tioconazole (MIC = 2 µg/mL). For C. dermatis, all strains could grow at 39 °C and could not express phospholipase, keratinase or gelatinase. However, all were capable of expressing urease, lipase and esterase. Three out of four strains could grow in a 10 % NaCl medium, but none grew in a 30 % NaCl medium. The strains showed high values of minimal inhibitory concentration. LMPV 90 was resistant to tioconazole, terbinafine, fluconazole and posaconazole, and LMS 38 was resistant to all antifungal agents tested. We discuss the characterization of C. haemulonii and C. dermatis as a possible emerging pathogen due to its animal-related enzymatic arsenal and antifungal resistance.

  6. Influence of Different Media, Incubation Times, and Temperatures for Determining the MICs of Seven Antifungal Agents against Paracoccidioides brasiliensis by Microdilution

    PubMed Central

    Cruz, R. C.; Werneck, S. M. C.; Oliveira, C. S.; Santos, P. C.; Soares, B. M.; Santos, D. A.

    2013-01-01

    MIC assays with Paracoccidioides brasiliensis, the etiological agent of paracoccidioidomycosis, had been conducted with variable protocols, employing both macrodilution and microdilution tests and including differences in inoculum preparation, media used, incubation periods, and temperatures. Twenty-one clinical and environmental isolates of Paracoccidioides were tested using amphotericin B, itraconazole, ketoconazole, fluconazole, sulfamethoxazole, sulfamethoxazole-trimethoprim, and terbinafine, according to the National Committee for Clinical Laboratory Standards (National Committee for Clinical Laboratory Standards, document M27-A2, 2002), with modifications such as three medium formulations (RPMI 1640 medium, McVeigh and Morton [MVM] medium, and modified Mueller-Hinton [MMH] medium), two incubation temperatures (room temperature [25 to 28°C] and 37°C), and three incubation periods (7, 10, and 15 days). The antifungal activities were also classified as fungicidal or fungistatic. The best results were obtained after 15 days of incubation, which was chosen as the standard incubation time. The MICs for most individual isolates grown for the same length of time at the same temperature varied with the different media used (P < 0.05). Of the isolates, 81% showed transition from the yeast to the mycelial form in RPMI 1640 medium at 37°C, independent of the presence of antifungals. MMH medium appears to be a suitable medium for susceptibility testing of antifungal drugs with P. brasiliensis, except for sulfamethoxazole and the combination of sulfamethoxazole-trimethoprim, for which the MVM medium yielded better results. The incubation temperature influenced the MICs, with, in general, higher MICs at 25°C (mycelial form) than at 37°C (P < 0.05). Based on our results, we tentatively propose a microdilution assay protocol for susceptibility testing of antifungal drugs against Paracoccidioides. PMID:23175254

  7. Morphological Effect of the New Antifungal Agent ME1111 on Hyphal Growth of Trichophyton mentagrophytes, Determined by Scanning and Transmission Electron Microscopy.

    PubMed

    Nishiyama, Yayoi; Takahata, Sho; Abe, Shigeru

    2017-01-01

    The effects of ME1111, a novel antifungal agent, on the hyphal morphology and ultrastructure of Trichophyton mentagrophytes were investigated by using scanning and transmission electron microscopy. Structural changes, such as pit formation and/or depression of the cell surface, and degeneration of intracellular organelles and plasmolysis were observed after treatment with ME1111. Our results suggest that the inhibition of energy production by ME1111 affects the integrity and function of cellular membranes, leading to fungal cell death. Copyright © 2016 American Society for Microbiology.

  8. 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

    2014-06-02

    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.

  9. 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.

  10. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. 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. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  12. Evaluation of some classical hydrazones of ketones and 1,2-diketones as antileishmanial, antibacterial and antifungal agents.

    PubMed

    Al-Kahraman, Yasser M S A; Yasinzai, Masoom; Singh, Girija S

    2012-06-01

    The paper describes the synthesis and antimicrobial (antileishmanial, antibacterial and antifungal) activity of some classical hydrazones of benzophenones and of 1,2-diketones. N-(Diaryl) acyl derivatives of these hydrazones have also been synthesized and evaluated. 4,4,-Demthoxybenzil monohydrazone and 4,4'-dimethoxybenzophenone hydrazone showed significant antileishmanial activity. The effect of substituents on the bioactivity is discussed.

  13. Theoretical studies on nitrogen rich energetic azoles.

    PubMed

    Ghule, Vikas Dasharath; Sarangapani, Radhakrishnan; Jadhav, Pandurang M; Tewari, Surya P

    2011-06-01

    Different nitro azole isomers based on five membered heterocyclics were designed and investigated using computational techniques in order to find out the comprehensive relationships between structure and performances of these high nitrogen compounds. Electronic structure of the molecules have been calculated using density functional theory (DFT) and the heat of formation has been calculated using the isodesmic reaction approach at B3LYP/6-31G* level. All designed compounds show high positive heat of formation due to the high nitrogen content and energetic nitro groups. The crystal densities of these energetic azoles have been predicted with different force fields. All the energetic azoles show densities higher than 1.87 g/cm(3). Detonation properties of energetic azoles are evaluated by using Kamlet-Jacobs equation based on the calculated densities and heat of formations. It is found that energetic azoles show detonation velocity about 9.0 km/s, and detonation pressure of 40GPa. Stability of the designed compounds has been predicted by evaluating the bond dissociation energy of the weakest C-NO(2) bond. The aromaticity using nucleus independent chemical shift (NICS) is also explored to predict the stability via delocalization of the π-electrons. Charge on the nitro group is used to assess the impact sensitivity in the present study. Overall, the study implies that all energetic azoles are found to be stable and expected to be the novel candidates of high energy density materials (HEDMs).

  14. Prevalence and epidemiology of tinea pedis and toenail onychomycosis and antifungal susceptibility of the causative agents in patients with type 2 diabetes in Turkey.

    PubMed

    Oz, Yasemin; Qoraan, Iman; Oz, Ali; Balta, Ilknur

    2017-01-01

    Diabetes patients are particularly susceptible to fungal infections because their vascular and immunological systems are compromised. The present study aimed to determine prevalences of tinea pedis and onychomycosis, factors predisposing to their development, and antifungal susceptibilities of causative fungal species against fluconazole, itraconazole, and terbinafine in patients with type 2 diabetes mellitus (DM). Study groups were defined according to hemoglobin A1C rates of ≥6.5% for the diabetes group and ≤5.7% for control subjects. A total of 600 diabetes subjects and 152 control subjects were evaluated. Rates of onychomycosis and tinea pedis in diabetes patients, and associations with age, gender, blood glucose level, duration of diabetes and serum lipid profile were investigated, as were the distribution and antifungal susceptibility of agents isolated. Patients with onychomycosis and/or tinea pedis numbered 85 in the diabetes group and nine in the control group (P = 0.006). The development of onychomycosis or tinea pedis was significantly related to increasing age and male gender. Although the most common agents were dermatophytes, non-dermatophyte fungal isolates were not uncommon. Terbinafine was the most effective drug against dermatophytes but was invalid for non-dermatophyte isolates by in vitro antifungal susceptibility testing. The development of onychomycosis or tinea pedis was significantly related to type 2 DM, increasing age, and male gender. The most common isolate was Trichophyton rubrum. The isolation and identification of the fungus is important to the effective management of tinea pedis and onychomycosis in diabetes patients because non-dermatophyte fungi can cause these infections. © 2016 The International Society of Dermatology.

  15. Epidemiology of invasive aspergillosis and azole resistance in patients with acute leukaemia: the SEPIA Study.

    PubMed

    Koehler, Philipp; Hamprecht, Axel; Bader, Oliver; Bekeredjian-Ding, Isabelle; Buchheidt, Dieter; Doelken, Gottfried; Elias, Johannes; Haase, Gerhard; Hahn-Ast, Corinna; Karthaus, Meinolf; Kekulé, Alexander; Keller, Peter; Kiehl, Michael; Krause, Stefan W; Krämer, Carolin; Neumann, Silke; Rohde, Holger; La Rosée, Paul; Ruhnke, Markus; Schafhausen, Philippe; Schalk, Enrico; Schulz, Katrin; Schwartz, Stefan; Silling, Gerda; Staib, Peter; Ullmann, Andrew; Vergoulidou, Maria; Weber, Thomas; Cornely, Oliver A; Vehreschild, Maria J G T

    2017-02-01

    Invasive aspergillosis (IA) is a serious hazard to high-risk haematological patients. There are increasing reports of azole-resistant Aspergillus spp. This study assessed the epidemiology of IA and azole-resistant Aspergillus spp. in patients with acute leukaemia in Germany. A prospective multicentre cohort study was performed in German haematology/oncology centres. The incidence of probable and proven aspergillosis according to the revised EORTC/MSG criteria was assessed for all patients with acute leukaemia [acute myeloid leukaemia (AML) and acute lymphoblastic leukaemia (ALL)]. Cases were documented into a web-based case report form, and centres provided data on standards regarding prophylactic and diagnostic measures. Clinical isolates were screened centrally for azole resistance and, if applicable, underlying resistance mechanisms were analysed. Between September 2011 and December 2013, 179 cases of IA [6 proven (3.4%) and 173 probable (96.6%)] were diagnosed in 3067 patients with acute leukaemia. The incidence of IA was 6.4% among 2440 AML patients and 3.8% among 627 ALL patients. Mortality at Day 84 was 33.8% (49/145) and attributable mortality was 26.9% (39/145). At Day 84, 53 patients (29.6%) showed a complete response, 25 (14.0%) a partial response and 17 (9.5%) a deterioration or failure. A total of 77 clinical Aspergillus fumigatus isolates were collected during the study period. Two episodes of azole-resistant IA (1.1%) were caused by a TR/L98H mutation in the cyp51A gene. With only two cases of IA due to azole-resistant A. fumigatus, a change of antifungal treatment practices in Germany does not appear warranted currently. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

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

    PubMed Central

    Abdolrasouli, Alireza; Rhodes, Johanna; Hagen, Ferry; Rogers, Thomas R.; Chowdhary, Anuradha

    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

  17. Cryptic Species and Azole Resistance in the Aspergillus niger Complex▿†

    PubMed Central

    Howard, Susan J.; Harrison, Elizabeth; Bowyer, Paul; Varga, Janos; Denning, David W.

    2011-01-01

    Aspergillus niger is a common clinical isolate. Multiple species comprise the Aspergillus section Nigri and are separable using sequence data. The antifungal susceptibility of these cryptic species is not known. We determined the azole MICs of 50 black aspergilli, 45 from clinical specimens, using modified EUCAST (mEUCAST) and Etest methods. Phylogenetic trees were prepared using the internal transcribed spacer, beta-tubulin, and calmodulin sequences to identify strains to species level and the results were compared with those obtained with cyp51A sequences. We attempted to correlate cyp51A mutations with azole resistance. Etest MICs were significantly different from mEUCAST MICs (P < 0.001), with geometric means of 0.77 and 2.79 mg/liter, respectively. Twenty-six of 50 (52%) isolates were itraconazole resistant by mEUCAST (MICs > 8 mg/liter), with limited cross-resistance to other azoles. Using combined beta-tubulin/calmodulin sequences, the 45 clinical isolates grouped into 5 clades, A. awamori (55.6%), A. tubingensis (17.8%), A. niger (13.3%), A. acidus (6.7%), and an unknown group (6.7%), none of which were morphologically distinguishable. Itraconazole resistance was found in 36% of the isolates in the A. awamori group, 90% of the A. tubingensis group, 33% of the A. niger group, 100% of the A. acidus group, and 67% of the unknown group. These data suggest that cyp51A mutations in section Nigri may not play as important a role in azole resistance as in A. fumigatus, although some mutations (G427S, K97T) warrant further study. Numerous cryptic species are found in clinical isolates of the Aspergillus section Nigri and are best reported as “A. niger complex” by clinical laboratories. Itraconazole resistance was common in this data set, but azole cross-resistance was unusual. The mechanism of resistance remains obscure. PMID:21768508

  18. 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

  19. Asexual sporulation facilitates adaptation: The emergence of azole resistance in Aspergillus fumigatus.

    PubMed

    Zhang, Jianhua; Debets, Alfons J M; Verweij, Paul E; Melchers, Willem J G; Zwaan, Bas J; Schoustra, Sijmen E

    2015-10-01

    Understanding the occurrence and spread of azole resistance in Aspergillus fumigatus is crucial for public health. It has been hypothesized that asexual sporulation, which is abundant in nature, is essential for phenotypic expression of azole resistance mutations in A. fumigatus facilitating subsequent spread through natural selection. Furthermore, the disease aspergilloma is associated with asexual sporulation within the lungs of patients and the emergence of azole resistance. This study assessed the evolutionary advantage of asexual sporulation by growing the fungus under pressure of one of five different azole fungicides over seven weeks and by comparing the rate of adaptation between scenarios of culturing with and without asexual sporulation. Results unequivocally show that asexual sporulation facilitates adaptation. This can be explained by the combination of more effective selection because of the transition from a multicellular to a unicellular stage, and by increased mutation supply due to the production of spores, which involves numerous mitotic divisions. Insights from this study are essential to unravel the resistance mechanisms of sporulating pathogens to chemical compounds and disease agents in general, and for designing strategies that prevent or overcome the emerging threat of azole resistance in particular. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

  20. Barley and yeast β-glucans as new emulsifier agents for the development of aqueous natural antifungal formulations.

    PubMed

    Salgado, Marta; Rodríguez-Rojo, Soraya; Cocero, María José

    2017-10-15

    Barley and yeast β-glucans were selected, together with lecithin, to encapsulate resveratrol by emulsification-evaporation method to develop new and safer antifungal formulations. Different emulsification techniques were used: high-shear, high pressure and high pressure and temperature emulsification. Morphology, crystallinity, encapsulation efficiency and in vitro antifungal activity against Botrytis cinerea of the different formulations were evaluated. No significant differences between each emulsification procedure in particle size (below 90nm) and in encapsulation efficiency (70-100%) were observed; only barley β-glucan emulsions showed lower efficiency due to the formation of a gel that retained most of the active compound. A great influence of the emulsification method and the encapsulating material on the crystallinity of the particles was observed. The highest antifungal activity (up to 53% growth inhibition) was obtained by the formulations with yeast β-glucans, indicating an enhanced absorption of encapsulated resveratrol through the cell wall of the fungus at the presence of (1-3, 1-6)-β-glucans. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Lipopeptides, a novel protein, and volatile compounds contribute to the antifungal activity of the biocontrol agent Bacillus atrophaeus CAB-1.

    PubMed

    Zhang, Xiaoyun; Li, Baoqing; Wang, Ye; Guo, Qinggang; Lu, Xiuyun; Li, Shezeng; Ma, Ping

    2013-11-01

    Bacillus atrophaeus CAB-1 displays a high inhibitory activity against various fungal pathogens and suppresses cucumber powdery mildew and tomato gray mold. We extracted and identified lipopeptides and secreted proteins and volatile compounds produced by strain CAB-1 to investigate the mechanisms involved in its biocontrol performance. In vitro assays indicated all three types of products contributed to the antagonistic activity against the fungal pathogen Botrytis cinerea. Each of these components also effectively prevented the occurrence of the cucumber powdery mildew caused by Sphaerotheca fuliginea under greenhouse conditions. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry revealed that the major bioactive lipopeptide was fengycin A (C15-C17). We isolated the crude-secreted proteins of CAB-1 and purified a fraction with antifungal activity. This protein sequence shared a high identity with a putative phage-related pre-neck appendage protein, which has not been reported as an antifungal factor. The volatile compounds produced by CAB-1 were complex, including a range of alcohols, phenols, amines, and alkane amides. O-anisaldehyde represented one of the most abundant volatiles with the highest inhibition on the mycelial growth of B. cinerea. To our knowledge, this is the first report on profiling three types of antifungal substances in Bacilli and demonstrating their contributions to plant disease control.

  2. Activity of a Long-Acting Echinocandin (CD101) and Seven Comparator Antifungal Agents Tested against a Global Collection of Contemporary Invasive Fungal Isolates in the SENTRY 2014 Antifungal Surveillance Program

    PubMed Central

    Pfaller, Michael A.; Messer, Shawn A.; Rhomberg, Paul R.

    2017-01-01

    ABSTRACT The activity of CD101 and comparator antifungal agents against 606 invasive fungal isolates collected worldwide during 2014 was evaluated using the Clinical and Laboratory Standards Institute (CLSI) method. All Candida albicans (n = 251), Candida tropicalis (n = 51), Candida krusei (n = 16), and Candida dubliniensis (n = 11) isolates were inhibited by ≤0.12 μg/ml of CD101 and were susceptible or showed wild-type susceptibility to the other echinocandins tested. Five C. glabrata isolates (n = 100) displayed CD101 MIC values of 1 to 4 μg/ml, had elevated MICs of caspofungin (2 to >8 μg/ml), anidulafungin (2 to 4 μg/ml), and micafungin (2 to 4 μg/ml), and carried mutations on fks1 and fks2. Candida parapsilosis (n = 92) and Candida orthopsilosis (n = 10) displayed higher CD101 MIC values (ranges, 0.5 to 4 μg/ml and 0.12 to 2 μg/ml, respectively), and similar results were observed for the other echinocandins tested. Fluconazole resistance was noted among 11.0% of Candida glabrata isolates, 4.3% of C. parapsilosis isolates, and 2.0% of C. albicans and C. tropicalis isolates. The activity of CD101 against Aspergillus fumigatus (n = 56) was similar to that of micafungin and 2-fold greater than that of caspofungin but less than that of anidulafungin. These isolates had wild-type susceptibility to itraconazole, voriconazole, and posaconazole. The echinocandins had limited activity against Cryptococcus neoformans (n = 19). CD101 was as active as the other echinocandins against common fungal organisms recovered from patients with invasive fungal infections. The long half-life profile is very desirable for the prevention and treatment of serious fungal infections, especially in patients who can then be discharged from the hospital to complete antifungal therapy on an outpatient basis. PMID:28052853

  3. 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

  4. [A study for testing the antifungal susceptibility of yeast by the Japanese Society for Medical Mycology (JSMM) method. The proposal of the modified JSMM method 2009].

    PubMed

    Nishiyama, Yayoi; Abe, Michiko; Ikeda, Reiko; Uno, Jun; Oguri, Toyoko; Shibuya, Kazutoshi; Maesaki, Shigefumi; Mohri, Shinobu; Yamada, Tsuyoshi; Ishibashi, Hiroko; Hasumi, Yayoi; Abe, Shigeru

    2010-01-01

    The Japanese Society for Medical Mycology (JSMM) method used for testing the antifungal susceptibility of yeast, the MIC end point for azole antifungal agents, is currently set at IC(80). It was recently shown, however that there is an inconsistency in the MIC value between the JSMM method and the CLSI M27-A2 (CLSI) method, in which the end- point was to read as IC(50). To resolve this discrepancy and reassess the JSMM method, the MIC for three azoles, fluconazole, itraconazole and voriconazole were compared to 5 strains of each of the following Candida species: C. albicans, C. glabrata, C. tropicalis, C. parapsilosis and C. krusei, for a total of 25 comparisons, using the JSMM method, a modified JSMM method, and the CLSI method. The results showed that when the MIC end- point criterion of the JSMM method was changed from IC(80) to IC(50) (the modified JSMM method) , the MIC value was consistent and compatible with the CLSI method. Finally, it should be emphasized that the JSMM method, using a spectrophotometer for MIC measurement, was superior in both stability and reproducibility, as compared to the CLSI method in which growth was assessed by visual observation.

  5. 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

  6. Clinical manifestations of candidemia caused by uncommon Candida species and antifungal susceptibility of the isolates in a regional hospital in Taiwan, 2007-2014.

    PubMed

    Liu, Wei-Lun; Lai, Chih-Cheng; Li, Ming-Chi; Wu, Chi-Jung; Ko, Wen-Chien; Hung, Yi-Li; Tang, Hung-Jen; Hsueh, Po-Ren

    2017-08-26

    This retrospective study investigated clinical manifestations of candidemia caused by uncommon Candida species and antifungal susceptibility of the isolates in a regional hospital in Taiwan. The uncommon Candida species was initially defined as Candida species other than C. albicans, C. tropicalis, C. glabrata complex, C. parapsilosis complex and C. krusei. All uncommon Candida isolates were identified and confirmed by molecular methods. In vitro susceptibility testing of the uncommon Candida species to nine antifungal agents was conducted using the broth microdilution method with the Sensititre YeastOne (SYO) system (Trek Diagnostic Systems, Ltd., East Grimstead, UK). Twenty-one patients, comprising 11 males and 10 females with a median age of 69 years, were recruited. Cancer (n = 11) was the most common underlying disease, 19 (90.5%) cases had prior antibiotic exposure, and only two patients had prior antifungal use. The overall in-hospital mortality rate was 38.1% (n = 8). C. guilliermondii (n = 11) was the most common pathogen, followed by C. curvata (n = 3). C. guilliermondii isolates exhibited relatively high rates of azole minimum inhibitory concentrations (MICs) above epidemiological cut-off values (ECVs), whereas C. pelliculosa and C. lusitaniae isolates all remained susceptible to azoles. All three C. curvata isolates had high caspofungin (>8 mg/L) and fluconazole MICs (8 mg/L) and could be defined as multidrug-resistant. Uncommon Candida species frequently exhibit high rates of non-susceptibility to antifungals. Identification of all Candida isolates at the species level from blood samples is of value for treatment. Copyright © 2017. Published by Elsevier B.V.

  7. Selected Essential Oils as Antifungal Agents Against Antibiotic-Resistant Candida spp.: In Vitro Study on Clinical and Food-Borne Isolates.

    PubMed

    Rajkowska, Katarzyna; Kunicka-Styczyńska, Alina; Maroszyńska, Marta

    2017-01-01

    Candida spp. cause significant health problems, inducing various types of superficial and deep-seated mycoses in humans. As a result of the increasing antibiotic resistance among pathogenic yeasts, the interest in alternative agents of antifungal activity is growing. This study evaluated the antimicrobial activity of selected essential oils (EOs) against Candida clinical and food-borne strains, including antibiotic-resistant isolates, in relation to yeast cell surface hydrophobicity (CSH). Candida strains showed different range of susceptibility to tea tree, thyme, peppermint, and clove oils, and peppermint oil demonstrated the lowest anticandidal activity with minimal inhibitory concentrations (MICs) of 0.03-8.0% v/v. MIC values for thyme and clove oils ranged from 0.03% to 0.25% v/v, and for tea tree oil-from 0.12% to 2.0% v/v. The exception was Candida tropicalis food-borne strain, the growth of which was inhibited after application of EOs at concentration of 8% v/v. Due to diverse yeast susceptibility to EOs, isolates were divided into five clusters in a principal component analysis model, each containing both clinical and food-borne strains. Hydrophobic properties of yeast were also diversified, and 37% of clinical and 50% of food-borne strains exhibited high hydrophobicity. The study indicates high homology of clinical and food-borne Candida isolates in relation to their susceptibility to anticandidal agents and hydrophobic properties. The susceptibility of yeasts to EOs could be partially related to their CSH. High antifungal activity of examined EOs, also against antibiotic-resistant isolates, indicates their usefulness as agents preventing the development of Candida strains of different origin.

  8. Unpredictable susceptibility of emerging clinical moulds to tri-azoles: review of the literature and upcoming challenges for mould identification.

    PubMed

    Araujo, R; Oliveira, M; Amorim, A; Sampaio-Maia, B

    2015-07-01

    Tri-azoles represent the front-line drugs for the treatment of mould diseases; nevertheless, some emerging moulds, such as Fusarium spp., Scedosporium spp., Mucorales and others, may be less susceptible or resistant to these antifungals. A review of the literature was conducted on the susceptibility of rare moulds to the tri-azoles itraconazole, posaconazole and voriconazole. Particular attention was paid to isolates identified by molecular analyses. The range of susceptibility values described for the three tri-azoles was frequently large (from 0.06 to >16), and a high variability was found within each species; isolates were rarely reported as entirely susceptible to all tri-azoles. In addition, the susceptibility of 76 emerging moulds from our collection (including Hypocreales, Dothideomycetes, Scedosporium spp., Mucorales and rare Aspergillus spp.) to itraconazole and voriconazole was determined by the Clinical and Laboratory Standards Institute (CLSI) M38-A2 and European Committee for Antimicrobial Susceptibility Testing (EUCAST) methods. Susceptibility discrepancies (of two dilutions) were found comparing CLSI and EUCAST for Dothideomycetes; the values for the remaining moulds were similar. More practical, faster and inexpensive susceptibility tools are welcome for testing emerging moulds, as these tests still represent a critical tool to support clinicians on the selection of proper antifungal treatment. The susceptibility of emerging moulds to tri-azoles cannot be predicted exclusively following mould identification, as the isolates' susceptibilities showed highly variable values. Some emerging moulds still remain very difficult to identity, even following standard molecular analyses which result in complex fungal collections. This fact limits the definition of epidemiological cut-offs and clinical breakpoints that are still imperative for emerging moulds.

  9. Topical antifungal treatments for tinea cruris and tinea corporis.

    PubMed

    El-Gohary, Magdy; van Zuuren, Esther J; Fedorowicz, Zbys; Burgess, Hana; Doney, Liz; Stuart, Beth; Moore, Michael; Little, Paul

    2014-08-04

    .53 to 0.84, NNT 6, 95% CI 5 to 13), but there was no difference in mycological cure rate (RR 0.99, 95% CI 0.93 to 1.05). The quality of evidence for these two outcomes was rated as low for mycological cure and very low for clinical cure.All of the treatments that were examined appeared to be effective, but most comparisons were evaluated in single studies. There was no evidence for a difference in cure rates between tinea cruris and tinea corporis. Adverse effects were minimal - mainly irritation and burning; results were generally imprecise between active interventions and placebo, and between different classes of treatment. The pooled data suggest that the individual treatments terbinafine and naftifine are effective. Adverse effects were generally mild and reported infrequently. A substantial number of the studies were more than 20 years old and of unclear or high risk of bias; there is however, some evidence that other topical antifungal treatments also provide similar clinical and mycological cure rates, particularly azoles although most were evaluated in single studies.There is insufficient evidence to determine if Whitfield's ointment, a widely used agent is effective.Although combinations of topical steroids and antifungals are not currently recommended in any clinical guidelines, relevant studies included in this review reported higher clinical cure rates with similar mycological cure rates at the end of treatment, but the quality of evidence for these outcomes was rated very low due to imprecision, indirectness and risk of bias. There was insufficient evidence to confidently assess relapse rates in the individual or combination treatments.Although there was little difference between different classes of treatment in achieving cure, some interventions may be more appealing as they require fewer applications and a shorter duration of treatment. Further, high quality, adequately powered trials focusing on patient-centred outcomes, such as patient satisfaction

  10. Terbinafine in combination with other antifungal agents for treatment of resistant or refractory mycoses: investigating optimal dosing regimens using a physiologically based pharmacokinetic model.

    PubMed

    Dolton, Michael J; Perera, Vidya; Pont, Lisa G; McLachlan, Andrew J

    2014-01-01

    Terbinafine is increasingly used in combination with other antifungal agents to treat resistant or refractory mycoses due to synergistic in vitro antifungal activity; high doses are commonly used, but limited data are available on systemic exposure, and no assessment of pharmacodynamic target attainment has been made. Using a physiologically based pharmacokinetic (PBPK) model for terbinafine, this study aimed to predict total and unbound terbinafine concentrations in plasma with a range of high-dose regimens and also calculate predicted pharmacodynamic parameters for terbinafine. Predicted terbinafine concentrations accumulated significantly during the first 28 days of treatment; the area under the concentration-time curve (AUC)/MIC ratios and AUC for the free, unbound fraction (fAUC)/MIC ratios increased by 54 to 62% on day 7 of treatment and by 80 to 92% on day 28 compared to day 1, depending on the dose regimen. Of the high-dose regimens investigated, 500 mg of terbinafine taken every 12 h provided the highest systemic exposure; on day 7 of treatment, the predicted AUC, maximum concentration (Cmax), and minimum concentration (Cmin) were approximately 4-fold, 1.9-fold, and 4.4-fold higher than with a standard-dose regimen of 250 mg once daily. Close agreement was seen between the concentrations predicted by the PBPK model and the observed concentrations, indicating good predictive performance. This study provides the first report of predicted terbinafine exposure in plasma with a range of high-dose regimens.

  11. 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

  12. Prospective Multicenter International Surveillance of Azole Resistance in Aspergillus fumigatus

    PubMed Central

    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.

    2015-01-01

    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

  13. Direct, Regioselective N-Alkylation of 1,3-Azoles.

    PubMed

    Chen, Shuai; Graceffa, Russell F; Boezio, Alessandro A

    2016-01-04

    Regioselective N-alkylation of 1,3-azoles is a valuable transformation. Organomagnesium reagents were discovered to be competent bases to affect regioselective alkylation of various 1,3-azoles. Counterintuitively, substitution selectively occurred at the more sterically hindered nitrogen atom. Numerous examples are provided, on varying 1,3-azole scaffolds, with yields ranging from 25 to 95%.

  14. New facets of antifungal therapy.

    PubMed

    Chang, Ya-Lin; Yu, Shang-Jie; Heitman, Joseph; Wellington, Melanie; Chen, Ying-Lien

    2017-02-17

    Invasive fungal infections remain a major cause of morbidity and mortality in immunocompromised patients, and such infections are a substantial burden to healthcare systems around the world. However, the clinically available armamentarium for invasive fungal diseases is limited to 3 main classes (i.e., polyenes, triazoles, and echinocandins), and each has defined limitations related to spectrum of activity, development of resistance, and toxicity. Further, current antifungal therapies are hampered by limited clinical efficacy, high rates of toxicity, and significant variability in pharmacokinetic properties. New antifungal agents, new formulations, and novel combination regimens may improve the care of patients in the future by providing improved strategies to combat challenges associated with currently available antifungal agents. Likewise, therapeutic drug monitoring may be helpful, but its present use remains controversial due to the lack of available data. This article discusses new facets of antifungal therapy with a focus on new antifungal formulations and the synergistic effects between drugs used in combination therapy.

  15. Anti-Candida albicans natural products, sources of new antifungal drugs: A review.

    PubMed

    Zida, A; Bamba, S; Yacouba, A; Ouedraogo-Traore, R; Guiguemdé, R T

    2017-03-01

    Candida albicans is the most prevalent fungal pathogen in humans. Due to the development of drug resistance, there is today a need for new antifungal agents for the efficient management of C. albicans infections. Therefore, we reviewed antifungal activity, mechanisms of action, possible synergism with antifungal drugs of all natural substances experimented to be efficient against C. albicans for future. An extensive and systematic review of the literature was undertaken and all relevant abstracts and full-text articles analyzed and included in the review. A total of 111 documents were published and highlighted 142 anti-C. albicans natural products. These products are mostly are reported in Asia (44.37%) and America (28.17%). According to in vitro model criteria, from the 142 natural substances, antifungal activity can be considered as important for 40 (28.20%) and moderate for 24 (16.90%). Sixteen products have their antifungal activity confirmed by in vivo gold standard experimentation. Microbial natural products, source of antifungals, have their antifungal mechanism well described in the literature: interaction with ergosterol (polyenes), inhibition 1,3-β-d-glucan synthase (Echinocandins), inhibition of the synthesis of cell wall components (chitin and mannoproteins), inhibition of sphingolipid synthesis (serine palmitoyltransferase, ceramide synthase, inositol phosphoceramide synthase) and inhibition of protein synthesis (sordarins). Natural products from plants mostly exert their antifungal effects by membrane-active mechanism. Some substances from arthropods are also explored to act on the fungal membrane. Interestingly, synergistic effects were found between different classes of natural products as well as between natural products and azoles. Search for anti-C. albicans new drugs is promising since the list of natural substances, which disclose activity against this yeast is today long. Investigations must be pursued not only to found more new anti

  16. Synthesis and biological evaluation of a new series of N-acyldiamines as potential antibacterial and antifungal agents.

    PubMed

    Ferreira, Bianca da S; de Almeida, Angelina M; Nascimento, Thiago C; de Castro, Pedro P; Silva, Vania L; Diniz, Claúdio G; Le Hyaric, Mireille

    2014-10-01

    In continuation of our efforts to find new antimicrobial compounds, series of fatty N-acyldiamines were prepared from fatty methyl esters and 1,2-ethylenediamine, 1,3-propanediamine or 1,4-butanediamine. The synthesized compounds were screened for their antibacterial activity against Gram-positive bacteria (Staphylococcus aureus, Staphylococcus epidermidis), Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa) and for their antifungal activity against four species of Candida (C. albicans, C. tropicalis, C. glabrata and C. parapsilosis). Compounds 5a (N-(2-aminoethyl)dodecanamide), 5b (N-(2-aminoethyl)tetracanamide) and 6d (N-(3-aminopropyl)oleamide) were the most active against Gram-positive bacteria, with MIC values ranging from 1 to 16μg/mL and were evaluated for their activity against 21 clinical isolates of methicillin-resistant S. aureus. All the compounds exhibited good to moderate antifungal activity. Compared to chloramphenicol, compound 6b displayed a similar activity (MIC50=16μg/mL). A positive correlation could be established between lipophilicity and biological activity.

  17. Successful management of cryptococcosis of the bilateral adrenal glands and liver by unilateral adrenalectomy with antifungal agents: a case report

    PubMed Central

    2011-01-01

    Background Cryptococcus species usually affect the central nervous system and lungs in immunocompromised hosts. Although the adrenal glands can be involved in disseminated cryptococcosis, primary adrenal insufficiency caused by the fungal infection is uncommon. Case presentation We present a case of primary adrenal insufficiency with bilateral adrenal masses and liver invasion in a 43-year-old man with mild type 2 diabetes mellitus. Cryptococcosis was diagnosed by fine-needle aspiration biopsy of the liver mass. The serum cryptococcal antigen titer was elevated to 1:256. After 6 months of antifungal therapy with fluconazole and amphotericin B, the size of the liver mass was decreased, but no significant changes were observed in the bilateral adrenal masses and the serum cryptococcal antigen titer remained elevated at 1:128. To control the cryptococcosis, a laparoscopic left adrenalectomy was performed, followed by antifungal therapy. After the unilateral adrenalectomy, the size of the remaining right adrenal mass was reduced and the serum cryptococcal antigen titer declined to 1:4. Conclusions This is the first report describing adrenal cryptococcosis with adrenal insufficiency and liver invasion without central nervous system involvement. Adrenal cryptococcosis should be considered in the differential diagnosis for patients with bilateral adrenal masses with primary adrenal deficiency. Unilateral adrenalectomy was quite effective in controlling the cryptococcosis in this case. Even in patients with bilateral adrenal cryptococcosis, unilateral adrenalectomy should be an option for treatment of disseminated cryptococcosis. PMID:22166121

  18. Successful management of cryptococcosis of the bilateral adrenal glands and liver by unilateral adrenalectomy with antifungal agents: a case report.

    PubMed

    Matsuda, Yayoi; Kawate, Hisaya; Okishige, Yuka; Abe, Ichiro; Adachi, Masahiro; Ohnaka, Keizo; Satoh, Naoichi; Inokuchi, Junichi; Tatsugami, Katsunori; Naito, Seiji; Nomura, Masatoshi; Takayanagi, Ryoichi

    2011-12-14

    Cryptococcus species usually affect the central nervous system and lungs in immunocompromised hosts. Although the adrenal glands can be involved in disseminated cryptococcosis, primary adrenal insufficiency caused by the fungal infection is uncommon. We present a case of primary adrenal insufficiency with bilateral adrenal masses and liver invasion in a 43-year-old man with mild type 2 diabetes mellitus. Cryptococcosis was diagnosed by fine-needle aspiration biopsy of the liver mass. The serum cryptococcal antigen titer was elevated to 1:256. After 6 months of antifungal therapy with fluconazole and amphotericin B, the size of the liver mass was decreased, but no significant changes were observed in the bilateral adrenal masses and the serum cryptococcal antigen titer remained elevated at 1:128. To control the cryptococcosis, a laparoscopic left adrenalectomy was performed, followed by antifungal therapy. After the unilateral adrenalectomy, the size of the remaining right adrenal mass was reduced and the serum cryptococcal antigen titer declined to 1:4. This is the first report describing adrenal cryptococcosis with adrenal insufficiency and liver invasion without central nervous system involvement. Adrenal cryptococcosis should be considered in the differential diagnosis for patients with bilateral adrenal masses with primary adrenal deficiency. Unilateral adrenalectomy was quite effective in controlling the cryptococcosis in this case. Even in patients with bilateral adrenal cryptococcosis, unilateral adrenalectomy should be an option for treatment of disseminated cryptococcosis.

  19. Role of Aspergillus lentulus 14-α sterol demethylase (Cyp51A) in azole drug susceptibility.

    PubMed

    Mellado, Emilia; Alcazar-Fuoli, Laura; Cuenca-Estrella, Manuel; Rodriguez-Tudela, Juan L

    2011-12-01

    Recent studies have demonstrated that some morphologically atypical Aspergillus fumigatus strains are different species belonging to the section Fumigati. Aspergillus lentulus, one of these sibling species, is increasingly reported in patients under corticosteroid treatment. MICs of most antifungals in clinical use are elevated against A. lentulus, and it shows primary resistance to azole drugs. Two A. lentulus cytochrome P450 14-α sterol demethylases, encoded by A. lentulus cyp51A (Alcyp51A) and Alcyp51B genes, were identified. Targeted cyp51A gene knockout in A. lentulus showed that the intrinsic azole resistance of this species is cyp51A dependent. The Δcyp51A strain was morphologically indistinguishable from the A. lentulus wild-type strain, retaining the ability to cause pulmonary disease in neutropenic mice. The heterologous expression of A. lentulus cyp51A was performed in an A. fumigatus cyp51A-deficient strain, confirming that Cyp51A is responsible for the differences in A. lentulus-azole drug interaction.

  20. Structure of a secreted aspartic protease from C. albicans complexed with a potent inhibitor: implications for the design of antifungal agents.

    PubMed Central

    Abad-Zapatero, C.; Goldman, R.; Muchmore, S. W.; Hutchins, C.; Stewart, K.; Navaza, J.; Payne, C. D.; Ray, T. L.

    1996-01-01

    The three-dimensional structure of a secreted aspartic protease from Candida albicans complexed with a potent inhibitor reveals variations on the classical aspartic protease theme that dramatically alter the specificity of this class of enzymes. The structure presents: (1) an 8-residue insertion near the first disulfide (Cys 45-Cys 50, pepsin numbering) that results in a broad flap extending toward the active site; (2) a 7-residue deletion replacing helix hN2 (Ser 110-Tyr 114), which enlarges the S3 pocket; (3) a short polar connection between the two rigid body domains that alters their relative orientation and provides certain specificity; and (4) an ordered 11-residue addition at the carboxy terminus. The inhibitor binds in an extended conformation and presents a branched structure at the P3 position. The implications of these findings for the design of potent antifungal agents are discussed. PMID:8845753

  1. In vitro and in vivo antifungal activities of the essential oils of various plants against tomato grey mould disease agent Botrytis cinerea.

    PubMed

    Soylu, Emine Mine; Kurt, Sener; Soylu, Soner

    2010-10-15

    The aim of this study was to find an alternative to synthetic fungicides currently used in the control of devastating fungal pathogen Botrytis cinerea, the causal agent of grey mould disease of tomato. Antifungal activities of essential oils obtained from aerial parts of aromatic plants, which belong to the Lamiacea family such as origanum (Origanum syriacum L. var. bevanii), lavender (Lavandula stoechas L. var. stoechas) and rosemary (Rosmarinus officinalis L.), were investigated against B. cinerea. Contact and volatile phase effects of different concentrations of the essential oils were found to inhibit the growth of B. cinerea in a dose-dependent manner. Volatile phase effects of essential oils were consistently found to be more effective on fungal growth than contact phase effect. A volatile vapour of origanum oil at 0.2 μg/ml air was found to completely inhibit the growth of B. cinerea. Complete growth inhibition of pathogen by essential oil of lavender and rosemary was, however, observed at 1.6 μg/ml air concentrations. For the determination of the contact phase effects of the tested essential oils, origanum oil at 12.8 μg/ml was found to inhibit the growth of B. cinerea completely. Essential oils of rosemary and lavender were inhibitory at relatively higher concentrations (25.6 μg/ml). Spore germination and germ tube elongation were also inhibited by the essential oils tested. Light and scanning electron microscopic (SEM) observations revealed that the essential oils cause considerable morphological degenerations of the fungal hyphae such as cytoplasmic coagulation, vacuolations, hyphal shrivelling and protoplast leakage and loss of conidiation. In vivo assays with the origanum essential oil, being the most efficient essential oil, under greenhouse conditions using susceptible tomato plants resulted in good protection against grey mould severity especially as a curative treatment. This study has demonstrated that the essential oils are potential and

  2. 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

  3. Antifungal Amphiphilic Aminoglycosides

    PubMed Central

    Chang, C.-W. T.; Takemoto, J.Y.

    2014-01-01

    The attachment of alkyl and other hydrophobic groups to traditional antibacterial kanamycins and neomycins creates amphiphilic aminoglycosides with altered antimicrobial properties. In this review, we summarize the discovery of amphiphilic kanamycins that are antifungal, but not antibacterial, and that inhibit the growth of fungi by perturbation of plasma membrane functions. With low toxicities against plant and mammalian cells, they appear to specifically target the fungal plasma membrane. These new antifungal agents offer new options for fighting fungal pathogens and are examples of reviving old drugs to confront new therapeutic challenges. PMID:25110571

  4. 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

  5. Novel triazole antifungal drugs: focus on isavuconazole, ravuconazole and albaconazole.

    PubMed

    Pasqualotto, Alessandro C; Thiele, Karoline O; Goldani, Luciano Z

    2010-02-01

    Azoles are important compounds for the treatment of fungal infections. This review focuses on three azoles: isavuconazole, ravuconazole and albaconazole (Stiefel). These drugs exhibit a broad spectrum of activity in vitro, including activity against several fungal isolates that are resistant to other azoles. However, poor or limited activity of these compounds has been demonstrated against species of Fusarium and Scedosporium, as well as against Zygomycetes. As isavuconazole and ravuconazole have been developed both as intravenous and oral formulations, these compounds are suitable candidates for the treatment of various invasive fungal diseases. Most clinical trials with albaconazole have targeted mucocutaneous fungal infections. Although all of these agents appear to be well tolerated, cross-resistance is a concern in the azole family of compounds.

  6. In vitro antifungal activity of cassia fistula extracts against fluconazole resistant strains of Candida species from HIV patients.

    PubMed

    Sony, P; Kalyani, M; Jeyakumari, D; Kannan, I; Sukumar, R G

    2017-08-21

    Candida species is the fourth common cause of blood stream infections all over the world which is life threatening. Invasive candidiasis leads to increased mortality and morbidity especially in immunosuppressed. The antifungal resistance pattern in high-risk patients is major concern. The present study was to access the anticandidal activity of leaves, bark and seeds of Cassia fistula against fluconazole resistant Candida species, C. albicans, C. glabrata, C. krusei, C. tropicalis, C. kefyr and C. parapsilosis isolated from HIV patients. The predominant phytochemical component responsible for fungicidal activity was to be accessed. Ethanol, chloroform, petroleum ether and aqueous extracts of leaves, bark and seeds of C. fistula linn. was evaluated against Microbial type culture collection (MTCC) Candida strains and 21 fluconazole resistant clinical isolates. Antifungal activity was evaluated by agar diffusion and broth dilution techniques. The active phytochemical component present in the ethanol extract of seeds was accessed by high performance thin layer chromatography. The docking study was done with lanosterol 14-alpha demethylase, the azole drug target with the predominant phytochemical from the extract having antifungal activity. All the extracts of C. fistula showed excellent anticandidal activity. Ethanol extract of C. fistula seed exhibited the most inhibitory activity. C. krusei and C. parapsilosis were the most inhibited and C. kefyr was the least inhibited species. The predominant phytochemical active component of the ethanol extract of seed was gallic acid. Gallic acid showed excellent binding with lanosterol 14-alpha demethylase. The present study reports the antifungal activity of various extracts of Cassia fistula for the first time against fluconazole resistant Candida isolates. We can conclude that the polyphenolic compound gallic acid is a potent natural antifungal agent. Further research is needed to assess the pharmacokinetic

  7. 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.

  8. Essential Oils of Myrtaceae Species Growing Wild in Tunisia: Chemical Variability and Antifungal Activity Against Biscogniauxia mediterranea, the Causative Agent of Charcoal Canker.

    PubMed

    Yangui, Islem; Zouaoui Boutiti, Meriem; Boussaid, Mohamed; Messaoud, Chokri

    2017-07-01

    The chemical composition of five Eucalyptus species and five Myrtus communis L. populations was investigated using GC/MS and GC-FID. For Eucalyptus essential oils, 32 compounds, representing 88.56 - 96.83% of the total oil according to species, were identified. The main compounds were 1,8-cineole, α-pinene, p-cymene, γ-gurjunene, α-aromadendrene, and β-phellandrene. For Myrtle essential oils, 26 compounds, representing 93.13 - 98.91% of the total oil were identified. α-Pinene, 1,8-cineole, linalool, and myrtenyl acetate were found to be the major compounds. Principal component analysis (PCA) showed chemical differentiation between Eucalyptus species and between Myrtle populations. Biscogniauxia mediterranea, the causative agent of charcoal canker, was identified according to its morphological and molecular characteristics. Essential oils of the investigated Eucalyptus species and Myrtle populations were tested for their antifungal capacity against this fungus. The antifungal activity varied according to the essential oil composition. Biscogniauxia mediterranea exhibited powerful resistance to some essential oils including them of Eucalyptus lehmannii and Eucalyptus sideroxylon but it was very sensitive to Eucalyptus camaldulensis oil (IC50  = 3.83 mg/ml) and M. communis oil from Zaghouan (IC50  = 1 mg/ml). This sensitivity was found to be correlated to some essential oil compounds such as p-cymene, carvacrol, cuminaldehyde, and linalool. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  9. Screening for Microtubule-Disrupting Antifungal Agents by Using a Mitotic-Arrest Mutant of Aspergillus nidulans and Novel Action of Phenylalanine Derivatives Accompanying Tubulin Loss

    PubMed Central

    Kiso, Tetsuo; Fujita, Ken-Ichi; Ping, Xu; Tanaka, Toshio; Taniguchi, Makoto

    2004-01-01

    The microtubule, which is one of the major targets of anthelmintics, anticancer drugs, and fungicides, is composed mainly of α- and β-tubulins. We focused on a unique characteristic of an Aspergillus nidulans benA33 mutant to screen for microtubule-disrupting antifungal agents. This mutant, which has a β-tubulin with a mutation of a single amino acid, undergoes mitotic arrest due to the formation of hyperstable microtubules at 37°C. The heat sensitivity of the mutant is remedied by some antimicrotubule agents. We found that an agar plate assay with the mutant was able to distinguish three types of microtubule inhibitors. The growth recovery zones of the mutant were formed around paper disks containing microtubule inhibitors, including four benzimidazoles, ansamitocin P-3, griseofulvin, and rhizoxin, on the agar plate at 37°C. Nocodazole, thiabendazole, and griseofulvin reversed the mitotic arrest of the mutant and promoted its hyphal growth. Ansamitocin P-3 and rhizoxin showed growth recovery zones around the growth-inhibitory zones. Benomyl and carbendazim also reversed mitotic arrest but produced weaker growth recovery than the aforementioned drugs. Other microtubule inhibitors, such as colchicine, Colcemid, paclitaxel, podophyllotoxin, TN-16, vinblastine, and vincristine, as well as some cytoskeletal inhibitors tested, did not show such activity. In our screening, we newly identified two mycotoxins, citrinin and patulin, two sesquiterpene dialdehydes, polygodial and warburganal, and four phenylalanine derivatives, arphamenine A, l-2,5-dihydrophenylalanine (DHPA), N-tosyl-l-phenylalanine chloromethylketone, and N-carbobenzoxy-l-phenylalanine chloromethyl ketone. In a wild-type strain of A. nidulans, DHPA caused selective losses of microtubules, as determined by fluorescence microscopy, and of both α- and β-tubulins, as determined by Western blot analysis. This screening method involving the benA33 mutant of A. nidulans is useful, convenient, and highly

  10. 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.

  11. Antifungal efficacy of thymol, carvacrol, eugenol and menthol as alternative agents to control the growth of food-relevant fungi.

    PubMed

    Abbaszadeh, S; Sharifzadeh, A; Shokri, H; Khosravi, A R; Abbaszadeh, A

    2014-06-01

    This work is an attempt to examine the antifungal activity of thymol, carvacrol, eugenol and menthol against 11 food-decaying fungi. The susceptibility test for the compounds was carried out in terms of minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) using microdilution method in 96 multi-well microtiter plates. Results indicated that all compounds were effective to varying extents against various fungal isolates, with the highest efficacy displayed by carvacrol (mean MIC value: 154.5 μg/mL) (P<0.05). The incorporation of increased concentrations of all compounds to the media led to progressive and significant reduction in growth for all fungi. The most potent inhibitory activity of thymol, carvacrol, eugenol and menthol was found for Cladosporium spp. (MIC: 100 μg/mL), Aspergillus spp. (MIC: 100 μg/mL), Cladosporium spp. (MIC: 350 μg/mL), and Aspergillus spp. and Cladosporium spp. (MIC: 125 μg/mL), respectively. Thus, the application of these herbal components could be considered as a good alternatives to inhibit fungal growth and to reduce the use of synthetic fungicides. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  12. A substituted sulfonamide and its Co (II), Cu (II), and Zn (II) complexes as potential antifungal agents.

    PubMed

    Diaz, Jorge R A; Fernández Baldo, Martín; Echeverría, Gustavo; Baldoni, Héctor; Vullo, Daniela; Soria, Delia B; Supuran, Claudiu T; Camí, Gerardo E

    2016-01-01

    A sulfonamide 1-tosyl-1-H-benzo(d)imidazol-2-amine (TBZA) and three new complexes of Co(II), Cu(II), and Zn(II) have been synthesized. The compounds have been characterized by elemental analyses, FTIR, (1)H, and (13)C-NMR spectroscopy. The structure of the TBZA, and its Co(II) and Cu(II) complexes, was determined by X-ray diffraction methods. TBZA and its Co(II) complex crystallize in the triclinic P-1 space group, while the Cu(II) complex crystallizes in the monoclinic P21/c space group. Antifungal activity was screened against eight pathogenic yeasts: Candida albicans (DMic 972576), Candida krusei (DMic 951705), Candida glabrata (DMic 982882), Candida tropicalis (DMic 982884), Candida dubliniensis (DMic 93695), Candida guilliermondii (DMic 021150), Cryptococcus neoformans (ATCC 24067), and Cryptococcus gattii (ATCC MYA-4561). Results on the inhibition of various human (h) CAs, hCA I, II, IV, VII, IX, and XII, and pathogenic beta and gamma CAs are also reported.

  13. Comparison of two systemic antifungal agents, itraconazole and terbinafine, for the treatment of dermatophytosis in European hedgehogs (Erinaceus europaeus).

    PubMed

    Bexton, Steve; Nelson, Helen

    2016-12-01

    Dermatophytosis caused by Trichophyton erinacei is a common scaling and crusting skin disease affecting European hedgehogs (Erinaceus europaeus) admitted to wildlife rescue centres. The application of topical therapy can be challenging because wild hedgehogs are subject to stress and often roll into a ball when handled. Systemic antifungal therapy is more convenient but has not been evaluated in this species. To compare the efficacy of oral itraconazole versus oral terbinafine for the treatment of dermatophytosis affecting hedgehogs. A treatment trial was undertaken in a wildlife hospital involving 165 hedgehogs with naturally occurring dermatophytosis. Animals were randomly divided into two groups and treated with either itraconazole or terbinafine orally for 28 days. The therapeutic efficacy was evaluated after 14 and 28 days by mycological culture and clinical dermatological lesion scores. Both drugs were well tolerated and clinically effective. After 14 and 28 days of treatment, the respective mycological cure rate was 36.6% and 65.9% for the itraconazole-treated group and 92.8% and 98.8% for the terbinafine-treated group. Itraconazole and terbinafine were both effective for the treatment of dermatophytosis affecting hedgehogs; however, terbinafine was more effective. © 2016 ESVD and ACVD.

  14. cis-Acting Elements within the Candida albicans ERG11 Promoter Mediate the Azole Response through Transcription Factor Upc2p▿

    PubMed Central

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

    2007-01-01

    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 α-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

  15. Frequency of clinically isolated strains of oral Candida species at Kagoshima University Hospital, Japan, and their susceptibility to antifungal drugs in 2006–2007 and 2012–2013

    PubMed Central

    2014-01-01

    Background The isolation frequency and susceptibility to antifungal agents of oral Candida isolates from patients with oral candidiasis (OC) were compared between studies conducted in 2006–2007 and 2012–2013. Methods A total158 strains was isolated from 112 patients who visited Kagoshima University Hospital for the treatment of OC during the 14-month period from February 2012 and March 2013, and evaluated on the isolation frequency of each Candida strain and the susceptibility against antifungal drugs as compared to those evaluated in 2006–2007. Results There was a higher frequency of xerostomia as a chief complaint and of autoimmune disease in the 2012–2013 study than in the 2006–2007 study. More than 95% of Candida isolates were C. albicans and C. glabrata. In addition, the proportion of the latter increased from 12.3% in the 2006–2007 study to 23.4% in the 2012–2013 study, while the proportion of the former decreased from 86.2% to 72.8%, respectively. C. albicans was isolated in almost all patients, while C. glabrata was only isolated concomitantly with C. albicans. Minimal inhibitory concentrations (MICs) were not significantly different between groups with a few exceptions. Candida isolates, of which MICs surpassed break points, apparently increased for miconazole and itraconazole against C. glabrata in the 2012–2013 study, but this was not statistically significant. As a result, more cases of autoimmune disease, a greater number of C. glabrata isolates, and higher resistance to azoles were seen in the 2012–2013 study than in the 2006–2007 study. Conclusion These data indicate that with recent increases in C. glabrata infection, a causative fungus of OC, and in C. glabrata resistance to azoles, caution is needed in the selection of antifungal drugs for the treatment of OC. PMID:24552136

  16. [Species distribution and antifungal susceptibility of Candida spp. causing superficial mycosis. Coro, Falcon state, Venezuela].

    PubMed

    Saúl-García, Yotsabeth; Humbría-García, Leyla; Hernández-Valles, Rosaura

    2015-09-01

    Candida species other than C. albicans are often described as causative agents of superficial mycosis and are more resistant to treatment with azoles. In order to determine the distribution of species and in vitro antifungal susceptibility of Candida spp., one ambispective study, which analyzed 18 yeast isolates obtained from samples from patients diagnosed with superficial mycosis, was performed. Taxonomic identification was performed by macroscopic visualization of the growth characteristics in chromogenic agar and by conventional methods. The susceptibility to fluconazole and voriconazole was evaluated by the disc diffusion method. Most of the isolates (88.8%), came from nail samples. C. parapsilosis was the most common species, followed by C. tropicalis, C. albicans and C. krusei, which confirmed the prevalence of non-albicans species as a cause of superficial mycoses. The pattern of susceptibility to fluconazole and voriconazole was similar: all isolates of C. parapsilosis and C. albicans were susceptible, while 83.3% of C. tropicalis showed sensitivity to both antifungals. C. krusei, fluconazole-resistant species showed intermediate susceptibility io voriconazole. The use of chromogenic agar allowed to detect mixed infections in nail samples, involving Candida spp. and C. tropicalis in one case, the latter with resistance to both fluconazole and voriconazole. The results demonstrate the importance of species identification and susceptibility testing to avoid therapeutic failures in superficial mycoses.

  17. Stability indicating methods for the determination of some anti-fungal agents using densitometric and RP-HPLC methods.

    PubMed

    Mousa, Bahia Abbas; El-Kousy, Naglaa Mahmoud; El-Bagary, Ramzia Ismail; Mohamed, Nashwah Gadalla

    2008-02-01

    Two chromatographic methods were developed for the determination of some anti-fungal drugs in the presence of either their degradation products or cortisone derivatives. The densitometric method determined mixtures of each of ketoconazole (KT), clotrimazole (CL), miconazole nitrate (MN) and econazole nitrate (EN) with the degradation products of each one. Mixtures of MN with hydrocortisone (HC) and of EN with triamcinolone acetonide (TA) were also successfully separated and determined by this technique. For KT and CL, a mixture of methanol:water:triethylamine (70:28:2 v/v) was used as a developing system and the spots were scanned at 243 nm and 220 nm for KT and CL, respectively. For MN and EN, a mixture of hexane:isopropyl alcohol:triethylamine (80:17:3 v/v) was used as a developing system and the spots were scanned at 225 nm for both drugs. The HPLC method determined mixtures of CL or EN with their degradation products which were separated and quantified on a Zorbax C8 column. Elution was carried out using methanol:phosphate buffer pH 2.5 (65:35 v/v) as a mobile phase at a flow rate of 1.5 ml/min and UV detection at 220 nm for CL. For EN, a mixture of methanol:water containing 0.06 ml triethylamine pH 10 (75:25 v/v) was used as a mobile phase at a flow rate of 1.5 ml/min and UV detection at 225 nm. The methods were also used to separate mixtures of CL with betamethasone dipropionate (BD) and EN with TA in a laboratory prepared mixture and in pharmaceutical preparations. The methods were sensitive, precise and applicable for determination of the drugs in pharmaceutical dosage forms.

  18. [Recent advances in the study of new antifungal lead compounds].

    PubMed

    Wang, Sheng-zheng; Sheng, Chun-quan; Zhang, Wan-nian

    2010-08-01

    In recent years, the incidence and mortality rate of invasive fungal infection have increased dramatically, and it is of great significance to develop novel antifungal agents with new chemical structure and new mode of action. In this review, novel antifungal lead compounds reported from 2007 to 2009 are reviewed. Moreover, their chemical structures, antifungal activities and structure-activity relationships have been summarized, which can provide useful information for future study of antifungal agents.

  19. Azole drug import into the pathogenic fungus Aspergillus fumigatus.

    PubMed

    Esquivel, Brooke D; Smith, Adam R; Zavrel, Martin; White, Theodore C

    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 [(3)H]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.

  20. 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. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Genetic and Genomic Architecture of the Evolution of Resistance to Antifungal Drug Combinations

    PubMed Central

    Hill, Jessica A.; Ammar, Ron; Torti, Dax; Nislow, Corey; Cowen, Leah E.

    2013-01-01

    The evolution of drug resistance in fungal pathogens compromises the efficacy of the limited number of antifungal drugs. Drug combinations have emerged as a powerful strategy to enhance antifungal efficacy and abrogate drug resistance, but the impact on the evolution of drug resistance remains largely unexplored. Targeting the molecular chaperone Hsp90 or its downstream effector, the protein phosphatase calcineurin, abrogates resistance to the most widely deployed antifungals, the azoles, which inhibit ergosterol biosynthesis. Here, we evolved experimental populations of the model yeast Saccharomyces cerevisiae and the leading human fungal pathogen Candida albicans with azole and an inhibitor of Hsp90, geldanamycin, or calcineurin, FK506. To recapitulate a clinical context where Hsp90 or calcineurin inhibitors could be utilized in combination with azoles to render resistant pathogens responsive to treatment, the evolution experiment was initiated with strains that are resistant to azoles in a manner that depends on Hsp90 and calcineurin. Of the 290 lineages initiated, most went extinct, yet 14 evolved resistance to the drug combination. Drug target mutations that conferred resistance to geldanamycin or FK506 were identified and validated in five evolved lineages. Whole-genome sequencing identified mutations in a gene encoding a transcriptional activator of drug efflux pumps, PDR1, and a gene encoding a transcriptional repressor of ergosterol biosynthesis genes, MOT3, that transformed azole resistance of two lineages from dependent on calcineurin to independent of this regulator. Resistance also arose by mutation that truncated the catalytic subunit of calcineurin, and by mutation in LCB1, encoding a sphingolipid biosynthetic enzyme. Genome analysis revealed extensive aneuploidy in four of the C. albicans lineages. Thus, we identify molecular determinants of the transition of azole resistance from calcineurin dependence to independence and establish multiple

  2. Treating chromoblastomycosis with systemic antifungals.

    PubMed

    Bonifaz, Alexandro; Paredes-Solís, Vanessa; Saúl, Amado

    2004-02-01

    Chromoblastomycosis is a subcutaneous mycosis for which there is no treatment of choice but rather, several treatment options, with low cure rates and many relapses. The choice of treatment should consider several conditions, such as the causal agent (the most common one being Fonsecaea pedrosoi ), extension of the lesions, clinical topography and health status of the patient. Most oral and systemic antifungals have been used; the best results have been obtained with itraconazole and terbinafine at high doses, for a mean of 6 - 12 months. In extensive and refractory cases, chemotherapy with oral antifungals may be associated with thermotherapy (local heat and/or cryosurgery). Limited or early cases may be managed with surgical methods, always associated with oral antifungal agents. It is important to determine the in vitro sensitivity of the major causal agents to the various drugs, by estimating the minimum inhibitory concentration, as well as drug tolerability and drug interactions.

  3. In vitro activity of a novel broad-spectrum antifungal, E1210, tested against Aspergillus spp. determined by CLSI and EUCAST broth microdilution methods.

    PubMed

    Pfaller, Michael A; Duncanson, Frederick; Messer, Shawn A; Moet, Gary J; Jones, Ronald N; Castanheira, Mariana

    2011-11-01

    E1210 is a first-in-class broad-spectrum antifungal that suppresses hyphal growth by inhibiting fungal glycophosphatidylinositol (GPI) biosynthesis. In the present study, we extend these findings by examining the activity of E1210 and comparator antifungal agents against Aspergillus spp. by using the methods of the Clinical and Laboratory Standards Institute (CLSI) and the European Committee for Antimicrobial Susceptibility Testing (EUCAST) to test wild-type (WT) as well as amphotericin B (AMB)-resistant (-R) and azole-R strains (as determined by CLSI methods). Seventy-eight clinical isolates of Aspergillus were tested including 20 isolates of Aspergillus flavus species complex (SC), 22 of A. fumigatus SC, 13 of A. niger SC, and 23 of A. terreus SC. The collection included 15 AMB-R (MIC, ≥ 2 μg/ml) isolates of A. terreus SC and 10 itraconazole-R (MIC, ≥ 4 μg/ml) isolates of A. fumigatus SC (7 isolates), A. niger SC (2 isolates), and A. terreus SC (1 isolate). Comparator antifungal agents included anidulafungin, caspofungin, amphotericin B, itraconazole, posaconzole, and voriconazole. Both CLSI and EUCAST methods were highly concordant for E1210 and all comparators. The essential agreement (EA; ± 2 log(2) dilution steps) was 100% for all comparisons with the exception of posaconazole versus A. terreus SC (EA = 91.3%). The minimum effective concentration (MEC)/MIC(90) values (μg/ml) for E1210, anidulafungin, caspofungin, itraconazole, posaconazole, and voriconazole, respectively, were as follows for each species: for A. flavus SC, 0.03, ≤ 0.008, 0.12, 1, 1, and 1; for A. fumigatus SC, 0.06, 0.015, 0.12, >8, 1, and 4; for A. niger SC, 0.015, 0.03, 0.12, 4, 1, and 2; and for A. terreus SC, 0.06, 0.015, 0.12, 1, 0.5, and 1. E1210 was very active against AMB-R strains of A. terreus SC (MEC range, 0.015 to 0.06 μg/ml) and itraconazole-R strains of A. fumigatus SC (MEC range, 0.03 to 0.12 μg/ml), A. niger SC (MEC, 0.008 μg/ml), and A. terreus SC (MEC, 0.015

  4. In Vitro Activity of a Novel Broad-Spectrum Antifungal, E1210, Tested against Aspergillus spp. Determined by CLSI and EUCAST Broth Microdilution Methods ▿

    PubMed Central

    Pfaller, Michael A.; Duncanson, Frederick; Messer, Shawn A.; Moet, Gary J.; Jones, Ronald N.; Castanheira, Mariana

    2011-01-01

    E1210 is a first-in-class broad-spectrum antifungal that suppresses hyphal growth by inhibiting fungal glycophosphatidylinositol (GPI) biosynthesis. In the present study, we extend these findings by examining the activity of E1210 and comparator antifungal agents against Aspergillus spp. by using the methods of the Clinical and Laboratory Standards Institute (CLSI) and the European Committee for Antimicrobial Susceptibility Testing (EUCAST) to test wild-type (WT) as well as amphotericin B (AMB)-resistant (-R) and azole-R strains (as determined by CLSI methods). Seventy-eight clinical isolates of Aspergillus were tested including 20 isolates of Aspergillus flavus species complex (SC), 22 of A. fumigatus SC, 13 of A. niger SC, and 23 of A. terreus SC. The collection included 15 AMB-R (MIC, ≥2 μg/ml) isolates of A. terreus SC and 10 itraconazole-R (MIC, ≥4 μg/ml) isolates of A. fumigatus SC (7 isolates), A. niger SC (2 isolates), and A. terreus SC (1 isolate). Comparator antifungal agents included anidulafungin, caspofungin, amphotericin B, itraconazole, posaconzole, and voriconazole. Both CLSI and EUCAST methods were highly concordant for E1210 and all comparators. The essential agreement (EA; ±2 log2 dilution steps) was 100% for all comparisons with the exception of posaconazole versus A. terreus SC (EA = 91.3%). The minimum effective concentration (MEC)/MIC90 values (μg/ml) for E1210, anidulafungin, caspofungin, itraconazole, posaconazole, and voriconazole, respectively, were as follows for each species: for A. flavus SC, 0.03, ≤0.008, 0.12, 1, 1, and 1; for A. fumigatus SC, 0.06, 0.015, 0.12, >8, 1, and 4; for A. niger SC, 0.015, 0.03, 0.12, 4, 1, and 2; and for A. terreus SC, 0.06, 0.015, 0.12, 1, 0.5, and 1. E1210 was very active against AMB-R strains of A. terreus SC (MEC range, 0.015 to 0.06 μg/ml) and itraconazole-R strains of A. fumigatus SC (MEC range, 0.03 to 0.12 μg/ml), A. niger SC (MEC, 0.008 μg/ml), and A. terreus SC (MEC, 0.015

  5. 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.

  6. Determination of antifungal susceptibility patterns among the environmental isolates of Aspergillus fumigatus in Iran

    PubMed Central

    Mohammadi, Faezeh; Dehghan, Parvin; Nekoeian, Shahram; Hashemi, Seyed Jamal

    2016-01-01

    Background: In recent years, triazole-resistant environmental isolates of Aspergillus fumigatus have emerged in Europe and Asia. Azole resistance has been reported in patients who are treated with long-term azole therapy or exposure of the fungus spores to the azole fungicides used in agriculture. To date, a wide range of mutations in A. fumigatus have been described conferring azole-resistance, which commonly involves modifications in the cyp51A gene. We investigated antifungal susceptibility pattern of environmental isolates of A. fumigatus. Materials and Methods: In this study, 170 environmental samples collected from indoors surfaces of three hospitals in Iran. It was used β-tubulin gene to confirm the all of A. fumigatus isolates, which was identified by conventional methods. Furthermore, the antifungal susceptibility of itraconazole, voriconazole, and posaconazole was investigated using broth microdilution test, according to European Committee on Antimicrobial Susceptibility testing reference method. Results: From a total of 158 environmental molds fungi obtained from the hospitals, 58 isolates were identified as A. fumigatus by amplification of expected size of β-tubulin gene (~500 bp). In this study, in vitro antifungal susceptibility testing has shown that there were not high minimum inhibitory concentration values of triazole antifungals in all of the 58 environmental isolates of A. fumigatus. Conclusion: Our findings demonstrated that there was not azole-resistant among environmental isolates of A. fumigatus. Medical triazoles compounds have structural similarity with triazole fungicide compounds in agriculture, therefore, resistance development through exposure to triazole fungicide compounds in the environment is important but it sounds there is not a serious health problem in drug resistance in environmental isolates in Iran. PMID:27656605

  7. 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

  8. 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

  9. Posaconazole after previous antifungal therapy with voriconazole for therapy of invasive aspergillus disease, a retrospective analysis.

    PubMed

    Heinz, Werner J; Egerer, Gerlinde; Lellek, Heinrich; Boehme, Angelika; Greiner, Jochen

    2013-05-01

    Invasive aspergillosis is an important cause of morbidity and mortality in haematological patients. Current guidelines recommend voriconazole as first-line therapy. A change in class of antifungal agent is generally recommended for salvage therapy. The focus of this analysis was to assess if posaconazole is suitable for salvage therapy following voriconazole treatment. This was a retrospective investigation on patients with sequential antifungal therapy of posaconazole after voriconazole identified at four German hospitals. Response rates at 30 and 60 days following start of posaconazole application and toxicity of azoles by comparing liver enzymes and cholestasis parameters were evaluated. Data were analysed by descriptive statistics. Overall, the success rate was 72.2% [15 of 36 patients showed complete response (41.7%), 11 patients partial response (30.6%) at any time point], eight patients failed treatment and two were not evaluable. Mean laboratory values increased during voriconazole and decreased during posaconazole treatment: aspartate aminotransferase (increase: 31.9 U l(-1) vs. decrease: 19.6 U l(-1) ), alanine aminotransferase (32.4 U l(-1) vs. 19.8 U l(-1) ), gamma-glutamyl transferase (124.2 U l(-1) vs. 152.3 U l(-1) ) and alkaline phosphatase (71.5 U l(-1) vs. 40.3 U l(-1) ) respectively. No patient discontinued posaconazole therapy due to an adverse event. In this analysis posaconazole was a safe and effective antifungal salvage therapy in patients with prior administration of another triazole.

  10. Modern antifungal therapy for neutropenic fever.

    PubMed

    Corey, Melissa

    2006-06-01

    Empirical antifungal therapy has been shown to decrease the number of documented fungal infections in the setting of persistent fever during neutropenia. For decades, amphotericin B deoxycholate has been considered the agent of choice for first-line therapy in this setting. New antifungal agents associated with less toxicity, including the lipid formulations of amphotericin, voriconazole, and caspofungin, are now available and are considered to be suitable alternative first-line agents. In order to ensure appropriate therapy, however, the clinician must consider not only the differences between these antifungals but also patient-specific factors before initiating treatment.

  11. Trehalose pathway as an antifungal target

    PubMed Central

    Perfect, John R.; Tenor, Jennifer L.; Miao, Yi; Brennan, Richard G.

    2017-01-01

    ABSTRACT With an increasing immunocompromised population which is linked to invasive fungal infections, it is clear that our present 3 classes of antifungal agents may not be sufficient to provide optimal management to these fragile patients. Furthermore, with widespread use of antifungal agents, drug-resistant fungal infections are on the rise. Therefore, there is some urgency to develop the antifungal pipeline with the goal of new antifungal agent discovery. In this review, a simple metabolic pathway, which forms the disaccharide, trehalose, will be characterized and its potential as a focus for antifungal target(s) explained. It possesses several important features for development of antifungal agents. First, it appears to have fungicidal characteristics and second, it is broad spectrum with importance across both ascomycete and basidiomycete species. Finally, this pathway is not found in mammals so theoretically specific inhibitors of the trehalose pathway and its enzymes in fungi should be relatively non-toxic for mammals. The trehalose pathway and its critical enzymes are now in a position to have directed antifungal discovery initiated in order to find a new class of antifungal drugs. PMID:27248439

  12. In-vivo selection of an azole-resistant petite mutant of Candida glabrata.

    PubMed

    Bouchara, J P; Zouhair, R; Le Boudouil, S; Renier, G; Filmon, R; Chabasse, D; Hallet, J N; Defontaine, A

    2000-11-01

    Two isolates of Candida glabrata from the same stool sample from a bone marrow transplant recipient treated with fluconazole, and designated 1084-L for large colonies on yeast extract-peptone-dextrose-agar and 1084-S for small colonies, were analysed. In-vitro susceptibility tests with a commercially available disk diffusion procedure showed that isolate 1084-L had a susceptibility pattern typical of wild-type strains of C. glabrata with sensitivity to polyenes and the presence of resistant colonies randomly distributed within the inhibition zones for all azole compounds except tioconazole. In contrast, isolate 1084-S, which was found by pulsed-field gel electrophoresis and random amplification of polymorphic DNA to be genetically closely related to isolate 1084-L, exhibited cross-resistance to the azole compounds except tioconazole. Determination of MICs by the E-test method confirmed these results, showing that isolate 1084-S had greater sensitivity to amphotericin B and complete resistance to ketoconazole and fluconazole. Growth on agar plates containing glucose or glycerol as the sole carbon source suggested that the resistant isolate had a respiratory deficiency, which was further demonstrated by flow cytometric analysis of the fluorescence of rhodamine 123-stained blastoconidia. Restriction endonuclease analysis of mitochondrial DNA (mtDNA) established the mitochondrial origin of the respiratory deficiency. However, PCR amplification of the mtDNA with primers ML1 and ML6, as well as transmission electron microscopy, suggested a partial deletion of the mtDNA analogous to that described for rho- petite mutants of Saccharomyces cerevisiae. Together, these results provided evidence that the selection of azole-resistant petite mutants of C. glabrata may occur in vivo after fluconazole administration, which might explain, therefore, clinical failure of antifungal therapy.

  13. In Vitro Assessment of Antifungal Therapeutic Potential of Salivary Histatin-5, Two Variants of Histatin-5, and Salivary Mucin (MUC7) Domain 1

    PubMed Central

    Situ, Hongsa; Bobek, Libuse A.

    2000-01-01

    Human salivary histatin-5 (Hsn-5) is a 24-residue peptide that possesses potent antifungal activity in vitro. The MUC7 gene encodes human salivary low-molecular-weight mucin (MG2). The candidacidal activity of MUC7 domain 1 (MUC7 D1, the N-terminal 51 amino acid residues of MUC7) in vitro has also been demonstrated. In this study, we have investigated the antifungal therapeutic potential of Hsn-5, its two variants, R12I/K17N and R12I/H21L, and MUC7 D1. First, these peptides were tested for activities against different clinically important fungi. We found them to possess broad-spectrum antifungal activities; specifically, most exhibited excellent in vitro activity against eight clinically important fungal strains tested, including Candida albicans and Candida glabrata and their azole-resistant counterparts and Cryptococcus neoformans and its amphotericin B-resistant counterpart. These findings also suggest that the mechanism of action of both Hsn-5 and MUC7 D1 for these fungi is different from that of amphotericin B or azole antifungal agents. Second, we examined the stability of these peptides in whole human saliva and human serum. In saliva, the Hsn-5 variants R12I/K17N and R12I/H21L and MUC7 D1 degraded at a lower rate than Hsn-5. In human serum, MUC7 D1 was also more stable than Hsn-5; both peptides were more stable in serum than in saliva. Third, we examined the cytotoxicity of these peptides using human erythrocytes and two human cell lines (KB and HSG). No (or very low) hemolytic activity was observed with any of the four peptides, even at the highest protein concentration tested (200 μM), while amphotericin B caused 100% hemolysis at only 12.5 μM. The toxic effects of Hsn-5 and MUC7 D1 toward KB and HSG cells were also much lower than that of amphotericin B as measured by trypan blue exclusion. Together, these findings indicate that the investigated peptides possess high antifungal therapeutic potential, in particular for the treatment of drug

  14. Antifungal Susceptibilities of Candida Species Causing Vulvovaginitis and Epidemiology of Recurrent Cases

    PubMed Central

    Richter, Sandra S.; Galask, Rudolph P.; Messer, Shawn A.; Hollis, Richard J.; Diekema, Daniel J.; Pfaller, Michael A.

    2005-01-01

    There are limited data regarding the antifungal susceptibility of yeast causing vulvovaginal candidiasis, since cultures are rarely performed. Susceptibility testing was performed on vaginal yeast isolates collected from January 1998 to March 2001 from 429 patients with suspected vulvovaginal candidiasis. The charts of 84 patients with multiple positive cultures were reviewed. The 593 yeast isolates were Candida albicans (n = 420), Candida glabrata (n = 112), Candida parapsilosis (n = 30), Candida krusei (n = 12), Saccharomyces cerevisiae ( n = 9), Candida tropicalis (n = 8), Candida lusitaniae (n = 1), and Trichosporon sp. (n = 1). Multiple species suggesting mixed infection were isolated from 27 cultures. Resistance to fluconazole and flucytosine was observed infrequently (3.7% and 3.0%); 16.2% of isolates were resistant to itraconazole (MIC ≥ 1 μg/ml). The four imidazoles (econazole, clotrimazole, miconazole, and ketoconazole) were active: 94.3 to 98.5% were susceptible at ≤1 μg/ml. Among different species, elevated fluconazole MICs (≥16 μg/ml) were only observed in C. glabrata (15.2% resistant [R], 51.8% susceptible-dose dependent [S-DD]), C. parapsilosis (3.3% S-DD), S. cerevisiae (11.1% S-DD), and C. krusei (50% S-DD, 41.7% R, considered intrinsically fluconazole resistant). Resistance to itraconazole was observed among C. glabrata (74.1%), C. krusei (58.3%), S. cerevisiae (55.6%), and C. parapsilosis (3.4%). Among 84 patients with recurrent episodes, non-albicans species were more common (42% versus 20%). A ≥4-fold rise in fluconazole MIC was observed in only one patient with C. parapsilosis. These results support the use of azoles for empirical therapy of uncomplicated candidal vulvovaginitis. Recurrent episodes are more often caused by non-albicans species, for which azole agents are less likely to be effective. PMID:15872235

  15. 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.

  16. Azole-based chemoprophylaxis of invasive fungal infections in paediatric patients with acute leukaemia: an internal audit.

    PubMed

    Yunus, Sara; Pieper, Stephanie; Kolve, Hedwig; Goletz, Grazyna; Jürgens, Heribert; Groll, Andreas H

    2014-03-01

    Children and adolescents with acute myeloid leukaemia (AML) and recurrent acute leukaemias (RALs) are at high risk of life-threatening invasive fungal infections (IFIs). We analysed implementation, safety and efficacy of a standard operating procedure for oral, azole-based, mould-active antifungal prophylaxis. Patients with AML and RALs aged ≥13 years received 200 mg of posaconazole three times daily and patients aged 2-12 years received 200 mg of voriconazole two times daily from the completion of chemotherapy until haematopoietic recovery. Algorithms for fever or focal findings in all patients with haematological malignancies included blood cultures, high-resolution CT and other appropriate imaging, serial serum galactomannan, invasive diagnostics and pre-emptive therapy with change in class if on antifungal medication. From 2006 to 2010, 40 patients (0.8-17 years; 21 males) with newly diagnosed AML (n = 31) or RAL (n = 9) were admitted, of whom 36 received a total of 149 courses of chemotherapy (reasons for exclusion: contraindications and early death ≤3 days). Azole prophylaxis was given in 87.2% (n = 130/149) of episodes. Pre-emptive antifungal therapy for pulmonary infiltrates was initiated in 5/36 (13.9%) patients or 6/130 (4.6%) episodes for a duration of 3-22 days. No proven or probable IFIs occurred. Adverse events (AEs) were common but mostly low grade and reversible. Three courses (2.3%) were discontinued due to AEs. In simultaneously admitted new patients with acute lymphatic leukaemia (ALL; n = 101) and paediatric lymphomas (n = 29) not receiving standard antifungal prophylaxis, proven/probable IFIs occurred in 4 patients with ALL (4.0%) and 7/130 patients (5.4%) received pre-emptive therapy. Azole-based, mould-active antifungal prophylaxis in high-risk paediatric patients with AML and RALs was satisfactorily implemented, well tolerated and effective. The low rate of IFIs in patients with ALL/lymphoma supports the lack of a general indication for

  17. In vitro susceptibility of filamentous fungi from mycotic keratitis to azole drugs.

    PubMed

    Shobana, C S; Mythili, A; Homa, M; Galgóczy, L; Priya, R; Babu Singh, Y R; Panneerselvam, K; Vágvölgyi, C; Kredics, L; Narendran, V; Manikandan, P

    2015-03-01

    The in vitro antifungal activities of azole drugs viz., itraconazole, voriconazole, ketoconazole, econazole and clotrimazole were investigated in order to evaluate their efficacy against filamentous fungi isolated from mycotic keratitis. The specimen collection was carried out from fungal keratitis patients attending Aravind eye hospital and Post-graduate institute of ophthalmology, Coimbatore, India and was subsequently processed for the isolation of fungi. The dilutions of antifungal drugs were prepared in RPMI 1640 medium. Minimum inhibitory concentrations (MICs) were determined and MIC50 and MIC90 were calculated for each drug tested. A total of 60 fungal isolates were identified as Fusarium spp. (n=30), non-sporulating moulds (n=9), Aspergillus flavus (n=6), Bipolaris spp. (n=6), Exserohilum spp. (n=4), Curvularia spp. (n=3), Alternaria spp. (n=1) and Exophiala spp. (n=1). The MICs of ketoconazole, clotrimazole, voriconazole, econazole and itraconazole for all the fungal isolates ranged between 16 μg/mL and 0.03 μg/mL, 4 μg/mL and 0.015 μg/mL, 8 μg/mL and 0.015 μg/mL, 8 μg/mL and 0.015 μg/mL and 32 μg/mL and 0.06 μg/mL respectively. From the MIC50 and MIC90 values, it could be deciphered that in the present study, clotrimazole was more active against the test isolates at lower concentrations (0.12-5 μg/mL) when compared to other drugs tested. The results suggest that amongst the tested azole drugs, clotrimazole followed by voriconazole and econazole had lower MICs against moulds isolated from mycotic keratitis. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  18. Mechanisms of Antifungal Drug Resistance

    PubMed Central

    Cowen, Leah E.; Sanglard, Dominique; Howard, Susan J.; Rogers, P. David; Perlin, David S.

    2015-01-01

    Antifungal therapy is a central component of patient management for acute and chronic mycoses. Yet, treatment choices are restricted because of the sparse number of antifungal drug classes. Clinical management of fungal diseases is further compromised by the emergence of antifungal drug resistance, which eliminates available drug classes as treatment options. Once considered a rare occurrence, antifungal drug resistance is on the rise in many high-risk medical centers. Most concerning is the evolution of multidrug- resistant organisms refractory to several different classes of antifungal agents, especially among common Candida species. The mechanisms responsible are mostly shared by both resistant strains displaying inherently reduced susceptibility and those acquiring resistance during therapy. The molecular mechanisms include altered drug affinity and target abundance, reduced intracellular drug levels caused by efflux pumps, and formation of biofilms. New insights into genetic factors regulating these mechanisms, as well as cellular factors important for stress adaptation, provide a foundation to better understand the emergence of antifungal drug resistance. PMID:25384768

  19. 'On water' assisted synthesis and biological evaluation of nitrogen and sulfur containing hetero-1,4-naphthoquinones as potent antifungal and antibacterial agents.

    PubMed

    Tandon, Vishnu K; Maurya, Hardesh K; Verma, Manoj K; Kumar, Rohitashw; Shukla, Praveen K

    2010-06-01

    2-chloro-3-(4-methylpiperazin-1-yl)naphthalene-1,4-dione (3a), 2-chloro-3-(pyrrolidin-1-yl)naphthalene-1,4-dione (3b), 2-chloro-3-(piperidin-1-yl)naphthalene-1,4-dione (3c), 2-chloro-3-morpholinonaphthalene-1,4-dione (3d), 2-chloro-3-(2-phenylhydrazinyl)naphthalene-1,4-dione (3e), 2-(allylamino)-3-chloronaphthalene-1,4-dione (3f), 2-(3-chloro-1,4-dioxo-1,4-dihydronaphthalen-2-ylthio)acetic acid (3g), 2-(3-chloro-1,4-dioxo-1,4-dihydronaphthalen-2-ylthio)succinic acid (3h), methyl 2-(3-chloro-1,4-dioxo-1,4-dihydronaphthalen-2-ylthio)acetate (3i), 2-chloro-3-(2-mercaptoethylthio)naphthalene-1,4-dione (3j), 3-hydroxy-4-methyl-4H-naphtho[2,3-b][1,4]thiazine-5,10-dione (3k) and compounds 3l-q have been synthesized by a green methodology approach using water as solvent and evaluated for their antifungal and antibacterial activity. The antifungal profile of 3a-n indicated that compounds 3a-d, 3j, 3e and 3k have potent antifungal activity. Amongst the most promising antifungal compounds, 3a-g, 3j, 3k showed better antifungal activity than clinically prevalent antifungal drugs Fluconazole and Amphotericin-B against Trichophyton mentagraphytes and compounds 3j and 3k have been found to be lead antifungal bicyclic and tricyclic 1,4-naphthoquinones. Compound 3k also exhibited pronounced antibacterial activity. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

  20. Multilocus resistance evolution to azole fungicides in fungal plant pathogen populations.

    PubMed

    Mohd-Assaad, Norfarhan; McDonald, Bruce A; Croll, Daniel

    2016-12-01

    Evolution of fungicide resistance is a major threat to food production in agricultural ecosystems. Fungal pathogens rapidly evolved resistance to all classes of fungicides applied to the field. Resistance to the commonly used azole fungicides is thought to be driven mainly by mutations in a gene (CYP51) encoding a protein of the ergosterol biosynthesis pathway. However, some fungi gained azole resistance independently of CYP51 mutations and the mechanisms leading to CYP51-independent resistance are poorly understood. We used whole-genome sequencing and genome-wide association studies (GWAS) to perform an unbiased screen of azole resistance loci in Rhynchosporium commune, the causal agent of the barley scald disease. We assayed cyproconazole resistance in 120 isolates collected from nine populations worldwide. We found that mutations in highly conserved genes encoding the vacuolar cation channel YVC1, a transcription activator, and a saccharopine dehydrogenase made significant contributions to fungicide resistance. These three genes were not previously known to confer resistance in plant pathogens. However, YVC1 is involved in a conserved stress response pathway known to respond to azoles in human pathogenic fungi. We also performed GWAS to identify genetic polymorphism linked to fungal growth rates. We found that loci conferring increased fungicide resistance were negatively impacting growth rates, suggesting that fungicide resistance evolution imposed costs. Analyses of population structure showed that resistance mutations were likely introduced into local populations through gene flow. Multilocus resistance evolution to fungicides shows how pathogen populations can evolve a complex genetic architecture for an important phenotypic trait within a short time span.

  1. Update on Antifungal Drug Resistance

    PubMed Central

    Shor, Erika; Zhao, Yanan

    2015-01-01

    Invasive fungal infections remain a major source of global morbidity and mortality, especially among patients with underlying immune suppression. Successful patient management requires antifungal therapy. Yet, treatment choices are restricted due to limited classes of antifungal agents and the emergence of antifungal drug resistance. In some settings, the evolution of multidrug-resistant strains insensitive to several classes of antifungal agents is a major concern. The resistance mechanisms responsible for acquired resistance are well characterized and include changes in drug target affinity and abundance, and reduction in the intracellular level of drug by biofilms and efflux pumps. The development of high-level and multidrug resistance occurs through a stepwise evolution of diverse mechanisms. The genetic factors that influence these mechanisms are emerging and they form a complex symphony of cellular interactions that enable the cell to adapt and/or overcome drug-induced stress. Drivers of resistance involve a complex blend of host and microbial factors. Understanding these mechanisms will facilitate development of better diagnostics and therapeutic strategies to overcome and prevent antifungal resistance. PMID:26120512

  2. Antifungal Application of Nonantifungal Drugs

    PubMed Central

    Stylianou, Marios; Kulesskiy, Evgeny; Lopes, José Pedro; Granlund, Margareta; Wennerberg, Krister

    2014-01-01

    Candida species are the cause of 60% of all mycoses in immunosuppressed individuals, leading to ∼150,000 deaths annually due to systemic infections, whereas the current antifungal therapies either have toxic side effects or are insufficiently efficient. We performed a screening of two compound libraries, the Enzo and the Institute for Molecular Medicine Finland (FIMM) oncology collection library, for anti-Candida activity based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. From a total of 844 drugs, 26 agents showed activity against Candida albicans. Of those, 12 were standard antifungal drugs (SADs) and 7 were off-target drugs previously reported to be active against Candida spp. The remaining 7 off-target drugs, amonafide, tosedostat, megestrol acetate, melengestrol acetate, stanozolol, trifluperidol, and haloperidol, were identified with this screen. The anti-Candida activities of the new agents were investigated by three individual assays using optical density, ATP levels, and microscopy. The antifungal activities of these drugs were comparable to those of the SADs found in the screen. The aminopeptidase inhibitor tosedostat, which is currently in a clinical trial phase for anticancer therapy, displayed a broad antifungal activity against different Candida spp., including Candida glabrata. Thus, this screen reveals agents that were previously unknown to be anti-Candida agents, which allows for the design of novel therapies against invasive candidiasis. PMID:24277040

  3. Antifungal Lock Therapy

    PubMed Central

    Walraven, Carla J.

    2013-01-01

    The widespread use of intravascular devices, such as central venous and hemodialysis catheters, in the past 2 decades has paralleled the increasing incidence of catheter-related bloodstream infections (CR-BSIs). Candida albicans is the fourth leading cause of hospital-associated BSIs. The propensity of C. albicans to form biofilms on these catheters has made these infections difficult to treat due to multiple factors, including increased resistance to antifungal agents. Thus, curing CR-BSIs caused by Candida species usually requires catheter removal in addition to systemic antifungal therapy. Alternatively, antimicrobial lock therapy has received significant interest and shown promise as a strategy to treat CR-BSIs due to Candida species. The existing in vitro, animal, and patient data for treatment of Candida-related CR-BSIs are reviewed. The most promising antifungal lock therapy (AfLT) strategies include use of amphotericin, ethanol, or echinocandins. Clinical trials are needed to further define the safety and efficacy of AfLT. PMID:23070153

  4. Reversal of antifungal resistance mediated by ABC efflux pumps from Candida albicans functionally expressed in yeast.

    PubMed

    Schuetzer-Muehlbauer, Manuela; Willinger, Birgit; Egner, Ralf; Ecker, Gerhard; Kuchler, Karl

    2003-09-01

    The enhanced efflux of antifungal drugs through ATP-binding cassette (ABC) transporters constitutes a major cause of clinical multidrug resistance (MDR). The inhibition of drug efflux pumps by specific compounds is considered to be a feasible strategy to overcome clinical antifungal resistance. Therefore, several blockers of mammalian and yeast ABC drug pumps, including FK506, propafenones, as well as the antifungal drug terbinafine were tested for their capacity to reverse CDR-mediated azole resistance in bakers yeast and in clinical isolates of Candida albicans. We have functionally expressed the C. albicans Cdr1p and Cdr2p transporters in hypersensitive Saccharomyces cerevisiae recipient strains lacking several endogenous ABC pumps. Cdr1p and Cdr2p were functional in yeast, as they conferred pronounced drug resistance to known antifungal drugs, including azoles and terbinafine. We employ two functional assays to demonstrate that ABC pump inhibitors reverse CDR-mediated antifungal resistance, thereby restoring drug susceptibility of yeast cells and resistant clinical isolates. Our results suggest that reversal of antifungal resistance can be achieved through ABC pump-dependent and independent mechanisms.

  5. Design, synthesis and biological evaluation of novel nitrogen and sulfur containing hetero-1,4-naphthoquinones as potent antifungal and antibacterial agents.

    PubMed

    Tandon, Vishnu K; Maurya, Hardesh K; Mishra, Nripendra N; Shukla, Praveen K

    2009-08-01

    A series of 2-Arylamino-3-chloro-1,4-naphthoquinones (3), 2-Amino-3-arylsulfanyl-1,4-naphthoquinones (5), 2-Arylamino-3-arylsulfanyl-1,4-naphthoquinones (6), Dihydrobenzo[f]naphtho[2,3-b][1,4]thiazepine-6,11-diones (9) (via Pictet-Spengler cyclization), Isoindoline-1,3-dione derivatives of 1,4-naphthoquinone (13), 2,2'-(1,4-Dioxo-1,4-dihydronaphthalene-2,3-diyl)bis(methylene)dibenzonitrile (14), 13-Amino-12-substituted-6H-benzo[e]naphtho [2,3-b][1,4]diazepine-6,11(12H)-diones (15-16), 2-Chloro-3-arylsulfanyl-1,4-naphthoquinones (17-18) and 3-Methyl-6H-benzo[b]phenothiazine-6,11(12H)-dione (19) were synthesized and studied for their antifungal and antibacterial activities. The results indicate that compounds 3b, 5a and 5b have potent antifungal activity. Amongst the most promising antifungal compounds, 3b showed better antifungal activity than clinically prevalent antifungal drug Fluconazole (MIC(50)=2.0 microg/mL) against Sporothrix schenckii (MIC(50)=1.56 microg/mL), significant profile against Candida albicans (MIC(50)=1.56 microg/mL), Cryptococcus neoformans (MIC(50)=0.78 microg/mL) and T