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Markantonatou AM, Samaras K, Zachrou E, Vyzantiadis TA. Comparison of Four Methods for the in vitro Susceptibility Testing of Dermatophytes. Front Microbiol 2020; 11:1593. [PMID: 32760372 PMCID: PMC7371995 DOI: 10.3389/fmicb.2020.01593] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 06/18/2020] [Indexed: 12/05/2022] Open
Abstract
Objectives Infections caused by dermatophytes affect a high percentage of the population. Antifungal susceptibility testing (AST) can offer useful information about the susceptibility profiles of the pathogens as well as the concomitant documentation of the appropriate treatment. However, the slow growth rate of these fungi and their poor sporulation are factors that can delay and affect the performance of the AST. The proposed methods by the CLSI or the EUCAST are both laborious for the everyday routine. There are alternative applications which propose the use of an inoculum, consisting of a conidia-mycelium mixture or even plain mycelia, as well as the use of resazurin in order to facilitate the reading. The aim of this study was to compare these approaches to the EUCAST method and evaluate their performance. Methods Three alternative methods were compared to the EUCAST proposed methodology for conidia forming molds. The last was defined as the reference method. The methods under evaluation were (a) a fragmented mycelia method, (b) the EUCAST method with the addition of resazurin sodium salt solution and (c) the fragmented mycelia method with the addition of resazurin sodium salt solution. Twenty-two isolates (8 Trichophyton interdigitale, 8 T. rubrum, and 6 Microsporum canis) were tested against the antifungal agents of griseofulvin, terbinafine, fluconazole, and itraconazole. Results The essential agreement between the methods was calculated in percentages and a statistical analysis of the results was performed. Data evaluation revealed sufficient overall agreement of the methods with the addition of resazurin to the initial “uncolored” methods (98.9 and 97.5% for the EUCAST and the fragmented mycelia methods, respectively). The fragmented mycelia method exhibited a relatively sufficient overall agreement in comparison to the EUCAST method (90%) and not a satisfactory correlation, probably as a result of various issues of standardization. Conclusion The EUCAST method was found to be the more reliable one, whereas the addition of resazurin sodium salt solution facilitates the reading and provides a reliable and objective evaluation. The fragmented mycelia method could serve as an alternative that should be applied only in cases of poor or no sporulating dermatophytes.
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Affiliation(s)
- Anthi-Marina Markantonatou
- First Department of Microbiology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Konstantinos Samaras
- First Department of Microbiology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Evaggelia Zachrou
- First Department of Microbiology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
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2
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Mussin JE, Roldán MV, Rojas F, Sosa MDLÁ, Pellegri N, Giusiano G. Antifungal activity of silver nanoparticles in combination with ketoconazole against Malassezia furfur. AMB Express 2019; 9:131. [PMID: 31432275 PMCID: PMC6702292 DOI: 10.1186/s13568-019-0857-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 08/13/2019] [Indexed: 12/03/2022] Open
Abstract
Malassezia furfur is lipophilic and lipid-dependent yeast, inhabitant of human skin microbiota associated with several dermal disorders. In recent years, along with the advances in nanotechnology and the incentive to find new antimicrobial drugs, there has been a growing interest in the utilization of nanoparticles for the treatment of skin microbial infections. This work aimed to study the in vitro inhibitory activity of silver nanoparticles (AgNP) against 41 M. furfur clinical isolates, visualize the interaction between AgNP-Malassezia, evaluate the synergism with ketoconazole (KTZ) and to produce an antimicrobial gel of AgNP–KTZ. The synthesized AgNP were randomly distributed around the yeast surface and showed a fungicidal action with low minimal inhibitory concentration values. AgNP showed no antagonistic effect with KTZ. The broad-spectrum antimicrobial property with fungicidal action of AgNP and its accumulation in affected areas with a sustained release profile, added to the great antifungal activity of KTZ against Malassezia infections and other superficial mycoses, allowed us to obtain a gel based on carbopol formulated with AgNP–KTZ with the potential to improve the topical therapy of superficial malasseziosis, reduce the number of applications and, also, prevent the recurrence.
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3
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Li Z, Fu B, Green CM, Liu B, Zhang J, Lang Y, Chaturvedi S, Belfort M, Liao G, Li H. Cisplatin protects mice from challenge of Cryptococcus neoformans by targeting the Prp8 intein. Emerg Microbes Infect 2019; 8:895-908. [PMID: 31223062 PMCID: PMC6598491 DOI: 10.1080/22221751.2019.1625727] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 05/16/2019] [Indexed: 01/02/2023]
Abstract
The Prp8 intein is one of the most widespread eukaryotic inteins, present in important pathogenic fungi, including Cryptococcus and Aspergillus species. Because the processed Prp8 carries out essential and non-redundant cellular functions, a Prp8 intein inhibitor is a mechanistically novel antifungal agent. In this report, we demonstrated that cisplatin, an FDA-approved cancer drug, significantly arrested growth of Prp8 intein-containing fungi C. neoformans and C. gattii, but only poorly inhibited growth of intein-free Candida species. These results suggest that cisplatin arrests fungal growth through specific inhibition of the Prp8 intein. Cisplatin was also found to significantly inhibit growth of C. neoformans in a mouse model. Our results further showed that cisplatin inhibited Prp8 intein splicing in vitro in a dose-dependent manner by direct binding to the Prp8 intein. Crystal structures of the apo- and cisplatin-bound Prp8 inteins revealed that two degenerate cisplatin molecules bind at the intein active site. Mutation of the splicing-site residues led to loss of cisplatin binding, as well as impairment of intein splicing. Finally, we found that overexpression of the Prp8 intein in cryptococcal species conferred cisplatin resistance. Overall, these results indicate that the Prp8 intein is a novel antifungal target worth further investigation.
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Affiliation(s)
- Zhong Li
- New York State Department of Health, Wadsworth Center, Albany, NY, USA
| | - Bin Fu
- College of Pharmaceutical Sciences, Southwest University, Chongqing, People’s Republic of China
| | - Cathleen M. Green
- Department of Biological Sciences and RNA Institute, University at Albany, Albany, NY, USA
| | - Binbin Liu
- New York State Department of Health, Wadsworth Center, Albany, NY, USA
| | - Jing Zhang
- New York State Department of Health, Wadsworth Center, Albany, NY, USA
| | - Yuekun Lang
- New York State Department of Health, Wadsworth Center, Albany, NY, USA
| | - Sudha Chaturvedi
- New York State Department of Health, Wadsworth Center, Albany, NY, USA
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, USA
| | - Marlene Belfort
- Department of Biological Sciences and RNA Institute, University at Albany, Albany, NY, USA
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, USA
| | - Guojian Liao
- College of Pharmaceutical Sciences, Southwest University, Chongqing, People’s Republic of China
| | - Hongmin Li
- New York State Department of Health, Wadsworth Center, Albany, NY, USA
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, USA
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4
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Silva KVS, Lima MIO, Cardoso GN, Santos AS, Silva GS, Pereira FO. Inibitory effects of linalool on fungal pathogenicity of clinical isolates ofMicrosporum canisandMicrosporum gypseum. Mycoses 2017; 60:387-393. [DOI: 10.1111/myc.12606] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 12/08/2016] [Accepted: 01/10/2017] [Indexed: 11/28/2022]
Affiliation(s)
- Kaltz V. S. Silva
- Laboratory of Biochemistry; Academic Unit of Health, Education and Health Center; Federal University of Campina Grande; Cuité Brazil
| | - Maria I. O. Lima
- Laboratory of Biochemistry; Academic Unit of Health, Education and Health Center; Federal University of Campina Grande; Cuité Brazil
| | - Gustavo N. Cardoso
- Laboratory of Biochemistry; Academic Unit of Health, Education and Health Center; Federal University of Campina Grande; Cuité Brazil
| | - Aldeir S. Santos
- Laboratory of Biochemistry; Academic Unit of Health, Education and Health Center; Federal University of Campina Grande; Cuité Brazil
| | - Gezaíldo S. Silva
- Laboratory of Biochemistry; Academic Unit of Health, Education and Health Center; Federal University of Campina Grande; Cuité Brazil
| | - Fillipe O. Pereira
- Laboratory of Biochemistry; Academic Unit of Health, Education and Health Center; Federal University of Campina Grande; Cuité Brazil
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5
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Thatai P, Sapra B. Critical review on retrospective and prospective changes in antifungal susceptibility testing for dermatophytes. Mycoses 2016; 59:615-27. [DOI: 10.1111/myc.12514] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 04/19/2016] [Accepted: 04/19/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Purva Thatai
- Division of Pharmaceutics; Department of Pharmaceutical Sciences; Punjabi University; Patiala India
| | - Bharti Sapra
- Division of Pharmaceutics; Department of Pharmaceutical Sciences; Punjabi University; Patiala India
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6
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Du J, Bandara HMHN, Du P, Huang H, Hoang K, Nguyen D, Mogarala SV, Smyth HDC. Improved Biofilm Antimicrobial Activity of Polyethylene Glycol Conjugated Tobramycin Compared to Tobramycin in Pseudomonas aeruginosa Biofilms. Mol Pharm 2015; 12:1544-53. [DOI: 10.1021/mp500846u] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Ju Du
- Division
of Pharmaceutics, College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712, United States
| | - H. M. H. N. Bandara
- Division
of Pharmaceutics, College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Ping Du
- Division
of Pharmaceutics, College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Hui Huang
- Division
of Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Khang Hoang
- College
of Natural Sciences, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Dang Nguyen
- Division
of Pharmaceutics, College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Sri Vasudha Mogarala
- Division
of Pharmaceutics, College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Hugh D. C. Smyth
- Division
of Pharmaceutics, College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712, United States
- Center
for Infectious Disease, The University of Texas at Austin, Austin, Texas 78712, United States
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7
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Pawar K, Yadav A, Prasher P, Mishra S, Singh B, Singh P, Komath SS. Identification of an indole–triazole–amino acid conjugate as a highly effective antifungal agent. MEDCHEMCOMM 2015. [DOI: 10.1039/c5md00156k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Compounds constructed by the grafting of amino acid and triazole with an indole moiety were synthesized and investigated for antifungal activities wherein one of the compounds gave highly promising results.
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Affiliation(s)
- Kalpana Pawar
- School of Life Sciences
- Jawaharlal Nehru University
- New Delhi 110 067
- India
- Uttarakhand Technical University
| | - Anshuman Yadav
- School of Life Sciences
- Jawaharlal Nehru University
- New Delhi 110 067
- India
| | - Parteek Prasher
- Department of Chemistry
- Guru Nanak Dev University
- Amritsar 143005
- India
| | - Sahil Mishra
- Department of Chemistry
- Guru Nanak Dev University
- Amritsar 143005
- India
| | | | - Palwinder Singh
- Department of Chemistry
- Guru Nanak Dev University
- Amritsar 143005
- India
| | - Sneha Sudha Komath
- School of Life Sciences
- Jawaharlal Nehru University
- New Delhi 110 067
- India
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8
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Bandara HMHN, Harb A, Kolacny D, Martins P, Smyth HDC. Sound waves effectively assist tobramycin in elimination of Pseudomonas aeruginosa biofilms in vitro. AAPS PharmSciTech 2014; 15:1644-54. [PMID: 25155975 DOI: 10.1208/s12249-014-0200-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 08/08/2014] [Indexed: 12/20/2022] Open
Abstract
Microbial biofilms are highly refractory to antimicrobials. The aim of this study was to investigate the use of low-frequency vibration therapy (20-20 kHz) on antibiotic-mediated Pseudomonas aeruginosa biofilm eradication. In screening studies, low-frequency vibrations were applied on model biofilm compositions to identify conditions in which surface standing waves were observed. Alginate surface tension and viscosity were also measured. The effect of vibration on P. aeruginosa biofilms was studied using a standard biofilm assay. Subminimal inhibitory concentrations (sub-MIC) of tobramycin (5 μg/ml) were added to biofilms 3 h prior, during, and immediately after vibration and quantitatively assessed by (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) reduction assay (XTT) and, qualitatively, by confocal laser scanning microscopy (CLSM). The standing waves occurred at frequencies <1,000 Hz. Biofilms vibrated without sub-MIC tobramycin showed a significantly reduced metabolism compared to untreated controls (p < 0.05). Biofilms treated with tobramycin and vibrated simultaneously (450, 530, 610, and 650 Hz), or vibrated (450 and 650 Hz) then treated with tobramycin subsequently, or vibrated (610 Hz, 650 Hz) after 3 h of tobramycin treatment showed significantly lower metabolism compared to P. aeruginosa biofilm treated with tobramycin alone (p < 0.05). CLSM imaging further confirmed these findings. Low frequency vibrations assisted tobramycin in killing P. aeruginosa biofilms at sub-MIC. Thus, sound waves together with antibiotics are a promising approach in eliminating pathogenic biofilms.
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9
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Chen YL, Lehman VN, Averette AF, Perfect JR, Heitman J. Posaconazole exhibits in vitro and in vivo synergistic antifungal activity with caspofungin or FK506 against Candida albicans. PLoS One 2013; 8:e57672. [PMID: 23472097 PMCID: PMC3589401 DOI: 10.1371/journal.pone.0057672] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 01/23/2013] [Indexed: 11/19/2022] Open
Abstract
The object of this study was to test whether posaconazole, a broad-spectrum antifungal agent inhibiting ergosterol biosynthesis, exhibits synergy with the β-1,3 glucan synthase inhibitor caspofungin or the calcineurin inhibitor FK506 against the human fungal pathogen Candida albicans. Although current drug treatments for Candida infection are often efficacious, the available antifungal armamentarium may not be keeping pace with the increasing incidence of drug resistant strains. The development of drug combinations or novel antifungal drugs to address emerging drug resistance is therefore of general importance. Combination drug therapies are employed to treat patients with HIV, cancer, or tuberculosis, and has considerable promise in the treatment of fungal infections like cryptococcal meningitis and C. albicans infections. Our studies reported here demonstrate that posaconazole exhibits in vitro synergy with caspofungin or FK506 against drug susceptible or resistant C. albicans strains. Furthermore, these combinations also show in vivo synergy against C. albicans strain SC5314 and its derived echinocandin-resistant mutants, which harbor an S645Y mutation in the CaFks1 β-1,3 glucan synthase drug target, suggesting potential therapeutic applicability for these combinations in the future.
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Affiliation(s)
- Ying-Lien Chen
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Plant Pathology and Microbiology, National Taiwan University, Taipei, Taiwan
| | - Virginia N. Lehman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
| | - Anna F. Averette
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - John R. Perfect
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
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10
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Antifungal activity of eugenol analogues. Influence of different substituents and studies on mechanism of action. Molecules 2012; 17:1002-24. [PMID: 22262200 PMCID: PMC6268595 DOI: 10.3390/molecules17011002] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2011] [Revised: 01/13/2012] [Accepted: 01/13/2012] [Indexed: 11/22/2022] Open
Abstract
Twenty one phenylpropanoids (including eugenol and safrole) and synthetic analogues, thirteen of them new compounds, were evaluated for antifungal properties, first with non-targeted assays against a panel of human opportunistic pathogenic fungi. Some structure-activity relationships could be observed, mainly related to the influence of an allyl substituent at C-4, an OH group at C-1 and an OCH3 at C-2 or the presence of one or two NO2 groups in different positions of the benzene ring. All active compounds were tested in a second panel of clinical isolates of C. albicans and non-albicans Candida spp., Cryptococcus neoformans and dermatophytes. The eugenol derivative 4-allyl-2-methoxy-5-nitrophenol (2) was the most active structure against all strains tested, and therefore it was submitted to targeted assays. These studies showed that the antifungal activity of 2 was not reversed in the presence of an osmotic support such as sorbitol, suggesting that it does not act by inhibiting the fungal cell wall synthesis or assembly. On the other hand, the Ergosterol Assay showed that 2 did not bind to the main sterol of the fungal membrane up to 250 µg mL−1. In contrast, a 22% of fungal membrane damage was observed at concentrations = 1 × MIC and 71% at 4× MIC, when 2 was tested in the Cellular Leakage assay. The comparison of log P and MICs for all compounds revealed that the antifungal activity of the eugenol analogues would not to be related to lipophilicity.
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Comparative effects of micafungin, caspofungin, and anidulafungin against a difficult-to-treat fungal opportunistic pathogen, Candida glabrata. Antimicrob Agents Chemother 2011; 56:1215-22. [PMID: 22203604 DOI: 10.1128/aac.05872-11] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The aim of this study was to compare the in vitro and in vivo activities of micafungin, caspofungin, and anidulafungin against Candida glabrata. The MICs against 28 clinical isolates showed that the overall susceptibilities to caspofungin and to micafungin were not statistically different in the absence of human serum, whereas the isolates were less susceptible to micafungin than to caspofungin in its presence. Minimum fungicidal concentrations, as well as time-kill experiments, showed that caspofungin was more active than anidulafungin, while micafungin was superior to either caspofungin or anidulafungin without serum; its addition rendered caspofungin and micafungin equally effective. A murine model of systemic candidiasis against a C. glabrata-susceptible isolate was performed to study the effects of all three echinocandins, and kidney burden counts showed that caspofungin, micafungin, and anidulafungin were active starting from 0.25, 1, and 5 mg/kg of body weight/day, respectively. Two echinocandin-resistant strains of C. glabrata were selected: C. glabrata 30, a laboratory strain harboring the mutation Fks2p-P667T, and C. glabrata 51, a clinical isolate harboring the mutation Fks2p-D666G. Micafungin activity was shown to be as effective as or more effective than that of caspofungin or anidulafungin in terms of MICs. In vivo studies against these resistant strains showed that micafungin was active starting from 1 mg/kg/day, while caspofungin was effective only when administrated at higher doses of 5 or 10 mg/kg/day. Although a trend toward colony reduction was observed with the highest doses of anidulafungin, a significant statistical difference was never reached.
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12
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de Oliveira WA, de Oliveira Pereira F, de Luna GCDG, Lima IO, Wanderley PA, de Lima RB, de Oliveira Lima E. Antifungal activity of Cymbopogon winterianus jowitt ex bor against Candida albicans. Braz J Microbiol 2011; 42:433-41. [PMID: 24031651 PMCID: PMC3769829 DOI: 10.1590/s1517-83822011000200004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Revised: 05/22/2010] [Accepted: 11/04/2010] [Indexed: 11/21/2022] Open
Abstract
Candida albicans is an opportunistic yeast and a member of the normal human flora that commonly causes infections in patients with any type of deficiency of the immune system. The essential oils have been tested for antimycotic activity and pose much potential as antifungal agents. This work investigated the activity of the essential oil of Cymbopogon winterianus against C. albicans by MIC, MFC and time-kill methods. The essential oil (EO) was obtained by hydrodistillation using a Clevenger-type apparatus. It was tested fifteen strains of C. albicans. The MIC was determined by the microdilution method and the MFC was determined when an aliquot of the broth microdilution was cultivated in SDA medium. The phytochemical analysis of EO showed presence of citronellal (23,59%), geraniol (18,81%) and citronellol (11,74%). The EO showed antifungal activity, and the concentrations 625 µg/mL and 1250 µg/mL inhibited the growth of all strains tested and it was fungicidal, respectively. The antimicrobial activity of various concentrations of EO was analyzed over time, it was found concentration-dependent antifungal activity, whose behavior was similar to amphotericin B and nystatin.
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Affiliation(s)
- Wylly Araújo de Oliveira
- Laboratório de Tecnologia Farmacêutica, Centro de Ciências da Saúde, Universidade Federal da Paraíba , João Pessoa. PB , Brasil ; Centro de Educação e Saúde, Universidade Federal de Campina Grande , Cuité, PB , Brasil
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13
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Activities of triazole-echinocandin combinations against Candida species in biofilms and as planktonic cells. Antimicrob Agents Chemother 2011; 55:1968-74. [PMID: 21343465 DOI: 10.1128/aac.00959-10] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Biofilm formation complicates the treatment of various infections caused by Candida species. We investigated the effects of simultaneous or sequential combinations of two triazoles, voriconazole (VRC) and posaconazole (PSC), with two echinocandins, anidulafungin (AND) and caspofungin (CAS), against Candida albicans and Candida parapsilosis biofilms in comparison to their planktonic counterparts. Antifungal activity was assessed by the 2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]2H-tetrazolium-5-carboxanilide (XTT) metabolic assay. Antifungal-agent interactions were analyzed by the Bliss independence model in the simultaneous-treatment studies and by analysis of variance (ANOVA) in the sequential-treatment studies. Against C. albicans planktonic cells, the simultaneous combination of PSC (32 to 128 mg/liter) and CAS (0.008 to 0.25 mg/liter) was synergistic; the combinations of PSC (128 to 1,024 mg/liter) with AND (0.03 to 0.5 mg/liter) and VRC (32 to 512 mg/liter) with AND (0.008 to 0.03 mg/liter) were antagonistic. Against C. parapsilosis planktonic cells, the interaction between VRC (32 to 1,024 mg/liter) and CAS (1 to 16 mg/liter) was antagonistic. All simultaneous antifungal combinations demonstrated indifferent interactions against biofilms of both Candida species. Damage to biofilms of both species increased (P<0.01) in the presence of subinhibitory concentrations of echinocandins (0.008 to 0.064 mg/liter), followed by the addition of PSC (512 mg/liter for C. albicans and 64 to 512 mg/liter for C. parapsilosis) or VRC (256 to 512 mg/liter for C. albicans and 512 mg/liter for C. parapsilosis). Triazole-echinocandin combinations do not appear to produce antagonistic effects against Candida sp. biofilms, while various significant interactions occur with their planktonic counterparts.
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Kernt M, Kampik A. Endophthalmitis: Pathogenesis, clinical presentation, management, and perspectives. Clin Ophthalmol 2010; 4:121-35. [PMID: 20390032 PMCID: PMC2850824 DOI: 10.2147/opth.s6461] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Indexed: 12/07/2022] Open
Abstract
Endophthalmitis is a rare but sight-threatening complication that can occur after ocular surgery or trauma or as a consequence of systemic infection. To optimize visual outcome, early diagnosis and treatment are essential. Over recent decades, advances in hygienic standards, improved microbiologic and surgical techniques, development of powerful antimicrobial drugs, and the introduction of intravitreal antibiotic therapy have led to a decreased incidence and improved management of endophthalmitis. However, endophthalmitis still represents a serious clinical problem. This review focuses on current principles and techniques for evaluation and treatment of endophthalmitis. In addition, it addresses recent developments regarding antimicrobial treatment and prophylaxis of infectious endophthalmitis.
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Affiliation(s)
- M Kernt
- Department of Ophthalmology, Ludwig Maximilian University, Munich, Germany
| | - A Kampik
- Department of Ophthalmology, Ludwig Maximilian University, Munich, Germany
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15
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Differential activities of newer antifungal agents against Candida albicans and Candida parapsilosis biofilms. Antimicrob Agents Chemother 2007; 52:357-60. [PMID: 17938192 DOI: 10.1128/aac.00856-07] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The activities of voriconazole, posaconazole, caspofungin, and anidulafungin against Candida albicans and Candida parapsilosis biofilms were evaluated. In contrast to planktonic cells, the MICs for voriconazole and posaconazole for the biofilms of the two species were high (>or=256 and >64 mg/liter, respectively) but relatively low for the echinocandins caspofungin and anidulafungin (<or=1 and <or=2 mg/liter, respectively).
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16
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Choi HW, Shin JH, Lee JS, Cho D, Shin MG, Suh SP, Ryang DW. In Vitro Susceptibilities to Caspofungin and Micafungin of Clinical Isolates of Candida Species. Ann Lab Med 2006; 26:275-81. [DOI: 10.3343/kjlm.2006.26.4.275] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Hyun Woo Choi
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Jong Hee Shin
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Jin Sol Lee
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Duck Cho
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Myung Gun Shin
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Soon Pal Suh
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Dong Wook Ryang
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
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17
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Benjamin DK, Driscoll T, Seibel NL, Gonzalez CE, Roden MM, Kilaru R, Clark K, Dowell JA, Schranz J, Walsh TJ. Safety and pharmacokinetics of intravenous anidulafungin in children with neutropenia at high risk for invasive fungal infections. Antimicrob Agents Chemother 2006; 50:632-8. [PMID: 16436720 PMCID: PMC1366891 DOI: 10.1128/aac.50.2.632-638.2006] [Citation(s) in RCA: 189] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Anidulafungin is an echinocandin with activity against Candida species and Aspergillus species. Adult dosages under study are 50 mg/day for esophageal candidiasis and 100 mg/day for invasive candidiasis and aspergillosis. Little is known, however, about the safety and pharmacokinetics of anidulafungin in children. A multicenter, ascending-dosage study of neutropenic pediatric patients was therefore conducted. Patients were divided into two age cohorts (2 to 11 years and 12 to 17 years) and were enrolled into sequential groups to receive 0.75 or 1.5 mg/kg of body weight/day. Blood samples were obtained following the first and fifth doses. Anidulafungin was assayed in plasma, and pharmacokinetic parameters were determined. Safety was assessed using National Cancer Institute (NCI) common toxicity criteria. Pharmacokinetic parameters were determined for 12 patients at each dosage (0.75 mg/kg/day or 1.5 mg/kg/day). Concentrations and drug exposures were similar for patients between age cohorts, and weight-adjusted clearance was consistent across age. No drug-related serious adverse events were observed. One patient had fever (NCI toxicity grade of 3), and one patient had facial erythema, which resolved with slowing the infusion rate. Anidulafungin in pediatric patients was well tolerated and can be dosed based on body weight. Pediatric patients receiving 0.75 mg/kg/day or 1.5 mg/kg/day have anidulafungin concentration profiles similar to those of adult patients receiving 50 or 100 mg/day, respectively.
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Affiliation(s)
- Daniel K Benjamin
- Department of Pediatrics and Duke Clinical Research Institute, Duke University, Durham, North Carolina, USA
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18
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Majoros L, Kardos G, Szabó B, Sipiczki M. Caspofungin susceptibility testing of Candida inconspicua: correlation of different methods with the minimal fungicidal concentration. Antimicrob Agents Chemother 2005; 49:3486-8. [PMID: 16048965 PMCID: PMC1196219 DOI: 10.1128/aac.49.8.3486-3488.2005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Minimal inhibitory and minimal fungicidal concentrations of caspofungin were determined for 48 Candida inconspicua isolates. By using CLSI (formerly NCCLS) methodology with the partial inhibition endpoint criterion, caspofungin exhibited a good fungicidal effect against C. inconspicua (the MIC(90) was 0.25 microg/ml and the minimum fungicidal concentration [MFC] was 0.5 microg/ml after 24 h). Total inhibition yielded falsely elevated MICs, exceeding even the respective MFCs.
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Affiliation(s)
- L Majoros
- Department of Medical Microbiology, University of Debrecen, 4032 Debrecen, Nagyerdei krt. 98, Hungary.
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19
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Abstract
Echinocandins are a novel class of antifungal drugs. They have good activity against Candida spp and Aspergillus spp. Their low selective toxicity allows their administration at high doses with few secondary side effects. We have reviewed the available data on the endpoints for these drugs in their in vitro susceptibility testing on yeasts and moulds. The microdilution broth method is the most commonly used technique and MIC-1 (80% of growth inhibition) seems to be the most reliable endpoint when yeasts are tested. This endpoint also seems to be the most appropriate for the different drugs when they are combined with echinocandins using the checkerboard method for testing yeasts. By contrast, in the case of moulds, the minimum effective concentration (MEC) correlates better with the in vivo activity than the MIC when echinocandins are tested, and when these drugs are combined with other antifungals, MIC-2 (50% of growth inhibition) seems the most appropriate endpoint. Criteria based on drug pharmacodynamics is the most useful to define the echinocandin endpoints that best correlate with their in vivo efficacy.
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Affiliation(s)
- Francisco Javier Pastor
- Unitat de Microbiologia, Facultat de Medicina i Ciencies de la Salut, Universitat Rovira i Virgili, Reus, Spain.
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20
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Abstract
Anidulafungin (LY-303366, V-echinocandin trade mark, Vicuron Pharmaceuticals, Inc.) is a new echinocandin antifungal agent with broad spectrum activity against Candida and Aspergillus spp. Anidulafungin exhibits low toxicity, concentration-dependent fungicidal activity for Candida, and a prolonged post antifungal effect (> 12h). In vitro activity demonstrates excellent potency and spectrum versus azole-susceptible and -resistant Candida spp. and a low minimum effective concentration for Aspergillus spp. In vivo anidulafungin is fungicidal against Candida in neutropenic animal models of disseminated candidiasis. Against Candida anidulafungin exhibits concentration-dependent killing and clearance of residual fungal burden in target organs (liver, lung, spleen, kidney) and plasma/tissue concentrations exceed the minimum inhibitory and minimum fungicidal concentrations of the infecting organism throughout the dosing interval. Although the activity of anidulafungin in animal models of pulmonary or disseminated aspergillosis shows increased survival and improvement in the pulmonary infarct score, the effect on residual fungal burden and Aspergillus antigenemia determination does not indicate in vivo fungicidal activity. It seems that the major effect of anidulafungin and other echinocandins in vivo against Aspergillus spp. is the decrease in the angioinvasive potential of the organisms. Clinically, anidulafungin has been shown to be safe and effective in the treatment of oesophageal candidiasis and candidemia. Further clinical application of this new antifungal agent is warranted.
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Affiliation(s)
- Michael A Pfaller
- Section of Medical Microbiology, Department of Pathology, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA.
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22
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Krause DS, Simjee AE, van Rensburg C, Viljoen J, Walsh TJ, Goldstein BP, Wible M, Henkel T. A Randomized, Double-Blind Trial of Anidulafungin versus Fluconazole for the Treatment of Esophageal Candidiasis. Clin Infect Dis 2004; 39:770-5. [PMID: 15472806 DOI: 10.1086/423378] [Citation(s) in RCA: 192] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2003] [Accepted: 03/11/2004] [Indexed: 11/03/2022] Open
Abstract
Anidulafungin is a novel antifungal agent of the echinocandin class. This randomized, double-blind, double-dummy study compared the efficacy and safety of intravenous anidulafungin to that of oral fluconazole in 601 patients with endoscopically and microbiologically documented esophageal candidiasis. Patients received intravenous anidulafungin (100 mg on day 1, followed by 50 mg per day) or oral fluconazole (200 mg on day 1, followed by 100 mg per day) for 7 days beyond resolution of symptoms (range, 14-21 days). At the end of therapy, the rate of endoscopic success for anidulafungin (242 [97.2%] of 249 treated patients) was found to be statistically noninferior to that for fluconazole (252 [98.8%] of 255 treated patients; treatment difference, -1.6%; 95% confidence interval, -4.1 to 0.8). The safety profile of anidulafungin was similar to that of fluconazole; treatment-related adverse events occurred in 9.3% and 12.0% of patients, respectively. Laboratory parameters were similar between treatment arms. Anidulafungin is as safe and effective as oral fluconazole for the treatment of esophageal candidiasis, when assessed at the completion of therapy.
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Affiliation(s)
- David S Krause
- Vicuron Pharmaceuticals, King of Prussia, Pennsylvania 19406, USA.
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23
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Pfaller MA, Messer SA, Boyken L, Rice C, Tendolkar S, Hollis RJ, Diekema DJ. Further standardization of broth microdilution methodology for in vitro susceptibility testing of caspofungin against Candida species by use of an international collection of more than 3,000 clinical isolates. J Clin Microbiol 2004; 42:3117-9. [PMID: 15243069 PMCID: PMC446304 DOI: 10.1128/jcm.42.7.3117-3119.2004] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The influence of test variables on in vitro susceptibility testing of caspofungin was examined with 694 isolates of Candida albicans including seven laboratory-derived glucan synthesis mutants. The conditions providing the greatest separation between the mutant strains and the clinical isolates were RPMI medium, MIC end point criterion of partial inhibition, and incubation for 24 h. These testing conditions were then applied to 3,322 isolates of Candida spp. (3,314 clinical isolates and eight glucan synthesis mutants). Among the 11 isolates for which caspofungin MICs were >/=2 microg/ml, eight were accounted for by the glucan synthesis mutants. The MICs for >99% of isolates were </=1 microg/ml, and thus these isolates were differentiated from strains with reduced in vitro and in vivo susceptibilities to caspofungin.
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Affiliation(s)
- M A Pfaller
- Medical Microbiology Division, C606 GH, Department of Pathology, University of Iowa College of Medicine, Iowa City, IA 52242, USA.
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24
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Toriumi Y, Sugita T, Nakajima M, Matsushima T, Shinoda T. Antifungal pharmacodynamic characteristics of amphotericin B against Trichosporon asahii, using time-kill methodology. Microbiol Immunol 2002; 46:89-93. [PMID: 11939583 DOI: 10.1111/j.1348-0421.2002.tb02663.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We determined the MIC of amphotericin B against 45 Trichosporon asahii isolates from various clinical and environmental sources, and used in vitro time-kill methods to characterize the relationship between amphotericin B concentrations and MIC for four representative T. asahii isolates. Amphotericin B had concentration-dependent antifungal activity. MICs ranged from 0.5 to 16 microg/ml, and most T. asahii isolates (76%, 34/45) were inhibited at safely achievable amphotericin B serum concentrations (< or = 2 microg/ml). However, 40% (18/45) of isolates were not killed at these concentrations (MFCs from 1.0 to 32 microg/ml). At concentrations > or = 2 x MIC, amphotericin B exhibited fungicidal activity (< 99.9% reduction in CFU) over a 12-hr time-period; the maximal effect was achieved at > or =4 x MIC. Susceptibility testing confirmed the resistance of T. asahii to amphotericin B, and in vitro pharmacodynamic results also suggest that amphotericin B is not suitable therapy for T. asahii infection.
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Affiliation(s)
- Yoshimi Toriumi
- Department of Microbiology, Meiji Pharmaceutical University, Kiyose, Tokyo, Japan
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25
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Petraitis V, Petraitiene R, Groll AH, Roussillon K, Hemmings M, Lyman CA, Sein T, Bacher J, Bekersky I, Walsh TJ. Comparative antifungal activities and plasma pharmacokinetics of micafungin (FK463) against disseminated candidiasis and invasive pulmonary aspergillosis in persistently neutropenic rabbits. Antimicrob Agents Chemother 2002; 46:1857-69. [PMID: 12019101 PMCID: PMC127233 DOI: 10.1128/aac.46.6.1857-1869.2002] [Citation(s) in RCA: 157] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2001] [Revised: 11/25/2001] [Accepted: 02/25/2002] [Indexed: 11/20/2022] Open
Abstract
Micafungin (FK463) is an echinocandin that demonstrates potent in vitro antifungal activities against Candida and Aspergillus species. However, little is known about its comparative antifungal activities in persistently neutropenic hosts. We therefore investigated the plasma micafungin pharmacokinetics and antifungal activities of micafungin against experimental disseminated candidiasis and invasive pulmonary aspergillosis in persistently neutropenic rabbits. The groups with disseminated candidiasis studied consisted of untreated controls (UCs); rabbits treated with desoxycholate amphotericin B (DAMB) at 1 mg/kg of body weight/day; or rabbits treated with micafungin at 0.25, 0.5, 1, and 2 mg/kg/day intravenously. Compared with the UCs, rabbits treated with micafungin or DAMB showed significant dosage-dependent clearance of Candida albicans from the liver, spleen, kidney, brain, eye, lung, and vena cava. These in vivo findings correlated with the results of in vitro time-kill assays that demonstrated that micafungin has concentration-dependent fungicidal activity. The groups with invasive pulmonary aspergillosis studied consisted of UCs; rabbits treated with DAMB; rabbits treated with liposomal amphotericin B (LAMB) at 5 mg/kg/day; and rabbits treated with micafungin at 0.5, 1, and 2 mg/kg/day. In comparison to the significant micafungin dosage-dependent reduction of the residual burden (in log CFU per gram) of C. albicans in tissue, micafungin-treated rabbits with invasive pulmonary aspergillosis had no reduction in the concentration of Aspergillus fumigatus in tissue. DAMB and LAMB significantly reduced the burdens of C. albicans and A. fumigatus in tissues (P < 0.01). Persistent galactomannan antigenemia in micafungin-treated rabbits correlated with the presence of an elevated burden of A. fumigatus in pulmonary tissue. By comparison, DAMB- and LAMB-treated animals had significantly reduced circulating galactomannan antigen levels. Despite a lack of clearance of A. fumigatus from the lungs, there was a significant improvement in the rate of survival (P < 0.001) and a reduction in the level of pulmonary infarction (P < 0.05) in micafungin-treated rabbits. In summary, micafungin demonstrated concentration-dependent and dosage-dependent clearance of C. albicans from persistently neutropenic rabbits with disseminated candidiasis but not of A. fumigatus from persistently neutropenic rabbits with invasive pulmonary aspergillosis.
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Affiliation(s)
- Vidmantas Petraitis
- Immunocompromised Host Section, Pediatric Oncology Branch, National Cancer Institute, Bethesda, Maryland 20892, USA
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26
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Roling EE, Klepser ME, Wasson A, Lewis RE, Ernst EJ, Pfaller MA. Antifungal activities of fluconazole, caspofungin (MK0991), and anidulafungin (LY 303366) alone and in combination against Candida spp. and Crytococcus neoformans via time-kill methods. Diagn Microbiol Infect Dis 2002; 43:13-7. [PMID: 12052624 DOI: 10.1016/s0732-8893(02)00361-9] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The activities of the echinocandins caspofungin and anidulafungin were evaluated alone and in combination with fluconazole using time-kill methods against isolates of Candida albicans, Candida glabrata, Candida tropicalis, Candida krusei, and Cryptococcus neoformans. Antifungal concentrations tested against each isolate were 0.5 microg/mL and 20 microg/mL of fluconazole and 0.007 microg/mL and 2 microg/mL of both caspofungin and anidulafungin. In addition, 20 microg/mL of fluconazole was tested with 2 microg/mL of caspofungin and anidulafungin to test for additive or antagonistic activity. Finally 0.5 microg/mL of fluconazole was tested with 0.007 microg/mL of caspofungin and anidulafungin to test for synergy. Combinations of fluconazole and caspofungin or anidulafungin resulted in indifference. Azole-echinocandin combinations do not produce antagonistic effects; therefore, combinations of these agents may warrant future clinical evaluation.
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Affiliation(s)
- Ellen E Roling
- College of Pharmacy, The University of Iowa, Iowa City, Iowa 52242, USA
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27
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Kurtz MB, Rex JH. Glucan synthase inhibitors as antifungal agents. ADVANCES IN PROTEIN CHEMISTRY 2001; 56:423-75. [PMID: 11329859 DOI: 10.1016/s0065-3233(01)56011-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- M B Kurtz
- Merck Research Laboratories, R80Y-220, Infectious Diseases, P.O. Box 2000, Rahway, NJ 07065, USA
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28
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Abstract
Isolation of Candida sp less susceptible to traditional therapies and recovery of increasingly resistant isolates during antifungal therapy are growing problems. It is important for clinicians to be aware of trends and mechanisms responsible for the expression of resistance.
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Affiliation(s)
- M E Klepser
- College of Pharmacy, Ferris State University, Big Rapids, Michigan, USA
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29
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Petraitis V, Petraitiene R, Groll AH, Sein T, Schaufele RL, Lyman CA, Francesconi A, Bacher J, Piscitelli SC, Walsh TJ. Dosage-dependent antifungal efficacy of V-echinocandin (LY303366) against experimental fluconazole-resistant oropharyngeal and esophageal candidiasis. Antimicrob Agents Chemother 2001; 45:471-9. [PMID: 11158743 PMCID: PMC90315 DOI: 10.1128/aac.45.2.471-479.2001] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
V-echinocandin (VER-002; LY303366) is a semisynthetic derivative of echinocandin B and a potent inhibitor of fungal (1, 3)-beta-D-glucan synthase. We studied the antifungal efficacy, the concentrations in saliva and tissue, and the safety of VER-002 at escalating dosages against experimental oropharyngeal and esophageal candidiasis caused by fluconazole-resistant Candida albicans in immunocompromised rabbits. Study groups consisted of untreated controls, animals treated with VER-002 at 1, 2.5, and 5 mg/kg of body weight/day intravenously (i.v.), animals treated with fluconazole at 2 mg/kg/day i.v., or animals treated with amphotericin B at 0.3 mg/kg/day. VER-002-treated animals showed a significant dosage-dependent clearance of C. albicans from the tongue, oropharynx, esophagus, stomach, and duodenum in comparison to that for untreated controls. VER-002 also was superior to amphotericin B and fluconazole in clearing the organism from all sites studied. These in vivo findings are consistent with the results of in vitro time-kill assays, which demonstrated that VER-002 has concentration-dependent fungicidal activity. Esophageal tissue VER-002 concentrations were dosage proportional and exceeded the MIC at all dosages. Echinocandin concentrations in saliva were greater than or equal to the MICs at all dosages. There was no elevation of serum hepatic transaminase, alkaline phosphatase, bilirubin, potassium, or creatinine levels in VER-002-treated rabbits. In summary, the echinocandin VER-002 was well tolerated, penetrated the esophagus and salivary glands, and demonstrated dosage-dependent antifungal activity against fluconazole-resistant esophageal candidiasis in immunocompromised rabbits.
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Affiliation(s)
- V Petraitis
- Immunocompromised Host Section, Pediatric Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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30
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Arikan S, Lozano-Chiu M, Paetznick V, Rex JH. In vitro susceptibility testing methods for caspofungin against Aspergillus and Fusarium isolates. Antimicrob Agents Chemother 2001; 45:327-30. [PMID: 11120990 PMCID: PMC90285 DOI: 10.1128/aac.45.1.327-330.2001] [Citation(s) in RCA: 169] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We investigated the relevance of prominent reduction in turbidity macroscopically (MIC) and formation of aberrant hyphal tips microscopically (minimum effective concentration; MEC) in measuring the in vitro activity of caspofungin against Aspergillus and Fusarium. Caspofungin generated low MICs and MECs against Aspergillus, but not for Fusarium. While MICs increased inconsistently when the incubation time was prolonged, MEC appeared as a stable and potentially relevant endpoint in testing in vitro caspofungin activity.
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Affiliation(s)
- S Arikan
- Division of Infectious Diseases, Department of Internal Medicine, Center for the Study of Emerging and Reemerging Pathogens, University of Texas Medical School, Houston, Texas 77030, USA.
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31
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Moore CB, Oakley KL, Denning DW. In vitro activity of a new echinocandin, LY303366, and comparison with fluconazole, flucytosine and amphotericin B against Candida species. Clin Microbiol Infect 2001; 7:11-6. [PMID: 11284937 DOI: 10.1046/j.1469-0691.2001.00158.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To investigate the in vitro activity of LY303366 (LY) against Candida isolates comprising nine different species and comparison with fluconazole (FLU), flucytosine (5FC) and amphotericin B (AMB). METHODS The method used was a microtitre modification of the NCCLS M27-A accepted standard using either RPMI-1640 with 2% glucose (5FC and FLU) or antibiotic medium 3 with 2% glucose (LY and AMB). The minimum inhibitory concentration (MIC) was the lowest drug concentration that reduced growth by 80% compared with the drug-free control. Minimum fungicidal concentrations (MFCs; 99% kill) were also determined for all isolates for LY and AMB. RESULTS Overall, 58 of 105 (55.2%) isolates were resistant to FLU (MIC < or = 16 mg/L). There was no relationship between FLU and LY MICs for C. albicans or non-albicans species. For all isolates, geometric mean (GM) MIC values and ranges (in mg/L) were: LY 0.011 and < or = 0.001-16, FLU 8.72 and < or = 0.125- > 128, 5FC 0.393 and < or = 0.03- > 32, AMB 0.046 and 0.008-0.125. Differences in susceptibility to LY were seen: C. parapsilosis (n = 12, GM 0.4 and range 0.125-16) and C. guilliermondii (n = 8, GM 0.46 and range 0.25-1) were both found to be significantly less susceptible to LY than all other species (P < or = 0.05). For all isolates, geometric mean MFC values and ranges (in mg/L) were: LY 0.032 and 0.002-16, AMB 0.143 and 0.03-2. The MFC value was the same as or only one drug dilution higher than the MIC value for 69.5% and 48.6% of isolates tested for LY and AMB, respectively. Tolerance was described in 13.3% and 5.7% of isolates for LY and AMB, respectively. A reproducibility study performed on 20% of the isolates showed that 90.5%, 100%, 95.2% and 100% of isolates retested were the same or within one well of the original MIC value for LY, FLU, 5FC and AMB, respectively. CONCLUSIONS LY303366 shows promising antifungal activity in vitro and warrants further in vivo investigation.
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Affiliation(s)
- C B Moore
- Department of Microbiology, Hope Hospital, Salford, UK
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32
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Dodds ES, Drew RH, Perfect JR. Antifungal pharmacodynamics: review of the literature and clinical applications. Pharmacotherapy 2000; 20:1335-55. [PMID: 11079283 DOI: 10.1592/phco.20.17.1335.34901] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Invasive fungal infections are seen with growing frequency, likely due to increases in numbers of patients at risk of infection. Optimal selection and dosing of antifungal agents are important, as these infections are often refractory to available therapy. In contrast to antibacterials, studies examining the pharmacodynamic properties of antifungals and their application in treating invasive disease often are lacking. Agents administered for invasive infections are amphotericin B, flucytosine, and azole antifungals. Several drugs are under investigation, such as posiconazole, voriconazole, and the echinocandins, and preliminary pharmacodynamic data likely will help shape dosing regimens. Clinical trials that investigated dosage and administration, as well as the potential benefits of combination and sequential therapy, are addressed. In addition, antifungal susceptibility and animal models of infection are discussed.
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Affiliation(s)
- E S Dodds
- Campbell University School of Pharmacy, Buies Creek, North Carolina, USA
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33
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Ernst EJ, Klepser ME, Pfaller MA. Postantifungal effects of echinocandin, azole, and polyene antifungal agents against Candida albicans and Cryptococcus neoformans. Antimicrob Agents Chemother 2000; 44:1108-11. [PMID: 10722525 PMCID: PMC89826 DOI: 10.1128/aac.44.4.1108-1111.2000] [Citation(s) in RCA: 141] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The postantifungal effect (PAFE) of fluconazole, MK-0991, LY303366, and amphotericin B was determined against isolates of Candida albicans and Cryptococcus neoformans. Concentrations ranging from 0. 125 to 4 times the MIC were tested following exposure to the antifungal for 0.25 to 1 h. Combinations of azole and echinocandin antifungals (MK-0991 and LY303366) were tested against C. neoformans. Fluconazole displayed no measurable PAFE against Candida albicans or Cryptococcus neoformans, either alone or in combination with either echinocandin antifungal. MK-0991, LY303366, and amphotericin B displayed a prolonged PAFE of greater than 12 h against Candida spp. when tested at concentrations above the MIC for the organism and 0 to 2 h when tested at concentrations below the MIC for the organism.
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Affiliation(s)
- E J Ernst
- College of Pharmacy, The University of Iowa, Department of Pathology, The University of Iowa College of Medicine, Iowa City, Iowa 52242, USA.
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34
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Petraitiene R, Petraitis V, Groll AH, Candelario M, Sein T, Bell A, Lyman CA, McMillian CL, Bacher J, Walsh TJ. Antifungal activity of LY303366, a novel echinocandin B, in experimental disseminated candidiasis in rabbits. Antimicrob Agents Chemother 1999; 43:2148-55. [PMID: 10471556 PMCID: PMC89438 DOI: 10.1128/aac.43.9.2148] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The safety and antifungal activity of LY303366 (LY), a new broad-spectrum semisynthetic echinocandin, were studied against disseminated candidiasis in persistently neutropenic rabbits. In vitro time-kill assays demonstrated that LY has concentration-dependent fungicidal activity. The pharmacokinetics of LY in the plasma of nonneutropenic rabbits suggested a linear relationship between dose and area under the curve (AUC). The times spent above the MIC during the experimental dosing interval of 24 h were 4 h for LY at 0.1 mg/kg of body weight/day (LY0.1), 8 h for LY at 0.25 mg/kg/day (LY0.25), 12 h for LY at 0.5 mg/kg/day (LY0.5), and 20 h for LY at 1 mg/kg/day (LY1). Antifungal therapy was administered to infected rabbits for 10 days starting 24 h after the intravenous (i.v.) inoculation of 10(3) Candida albicans blastoconidia. Study groups consisted of untreated controls (UCs) and animals treated with amphotericin B (AmB; 1 mg/kg/day i.v.), fluconazole (FLU; 10 mg/kg/day i.v.), and LY0.1, LY0.25, LY0.5, or LY1 i.v. Rabbits treated with LY0.5, LY1, AmB, and FLU had similarly significant clearance of C. albicans from the liver, spleen, kidney, lung, vena cava, and brain in comparison to that for UCs. There was a dose-dependent clearance of C. albicans from tissues in response to LY. Among rabbits treated with LY0.1 there was a significant reduction of C. albicans only in the spleen. In animals treated with LY0.25 there was a significant reduction in all tissues but the brain. By comparison, LY0.5 and LY1 cleared all tissues, including the brain, of C. albicans. These in vivo findings were consistent with the results of in vitro time-kill assays. A dose-dependent effect of altered cell wall morphology was observed among UCs and animals treated with LY0.1, and LY0.25, with a progressive transition from hyphal structure to disrupted yeast forms. Serum creatinine levels were higher and serum potassium levels were lower in AmB-treated rabbits than in UCs and LY- and FLU-treated rabbits. LY0.5 and LY1 were well tolerated, displayed predictable pharmacokinetics in plasma, and had activities comparable to those of AmB and FLU in the treatment of disseminated candidiasis in persistently neutropenic rabbits.
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Affiliation(s)
- R Petraitiene
- Immunocompromised Host Section, Pediatric Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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