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Paiva JA, Pereira JM. Treatment of invasive candidiasis in the era of Candida resistance. Curr Opin Crit Care 2023; 29:457-462. [PMID: 37641511 DOI: 10.1097/mcc.0000000000001077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
PURPOSE OF REVIEW The increasing incidence of drug-resistant Candida brings a new challenge to the treatment of invasive candidiasis. Although cross-resistance among azoles and echinocandins was generally uncommon, reports of multidrug-resistant (MDR) Candida markedly increased in the last decade. The purpose of this review is to understand mechanisms and risk factors for resistance and how to tackle antifungal resistance. RECENT FINDINGS The paper describes the action of the three main classes of antifungals - azoles, echinocandins and polyenes - and Candida's mechanisms of resistance. The current evolution from cross-resistance to multiresistance among Candida explains the modern glossary - multidrug-resistant (MDR), extensively drug-resistant (XDR), and pandrug-resistant (PDR) - imported from bacteria. MDR Candida most commonly involves acquired resistance in species with intrinsic resistance, therefore it mostly involves C. glabrata, C. parapsilosis, C. krusei, C guilliermondii or C. auris , which is intrinsically multidrug resistant. Finally, strategies to tackle antifungal resistance became clearer, ideally implemented through antifungal stewardship. SUMMARY Avoiding antifungal's overuse and selecting the best drug, dose and duration, when they are needed, is fundamental. Knowledge of risk factors for resistance, microbiological diagnosis to the species, use of susceptibility test supported by antifungal stewardship programs help attaining effective therapy and sustaining the effectiveness of the current antifungal armamentarium.
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Affiliation(s)
- José-Artur Paiva
- Intensive Care Medicine Department, Centro Hospitalar Universitário S. João, Porto, Portugal
- Department of Medicine, Faculty of Medicine of University of Porto, Porto, Portugal
- Grupo de Infeção e Sepsis, Porto, Portugal
| | - José Manuel Pereira
- Intensive Care Medicine Department, Centro Hospitalar Universitário S. João, Porto, Portugal
- Department of Medicine, Faculty of Medicine of University of Porto, Porto, Portugal
- Grupo de Infeção e Sepsis, Porto, Portugal
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Bohner F, Papp C, Gácser A. The effect of antifungal resistance development on the virulence of Candida species. FEMS Yeast Res 2022; 22:6552956. [PMID: 35325128 PMCID: PMC9466593 DOI: 10.1093/femsyr/foac019] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 02/24/2022] [Accepted: 03/21/2022] [Indexed: 11/12/2022] Open
Abstract
In recent years, the relevance of diseases associated with fungal pathogens increased worldwide. Members of the Candida genus are responsible for the greatest number of fungal bloodstream infections every year. Epidemiological data consistently indicate a modest shift toward non-albicans species, albeit Candidaalbicans is still the most recognizable species within the genus. As a result, the number of clinically relevant pathogens has increased, and, despite their distinct pathogenicity features, the applicable antifungal agents remained the same. For bloodstream infections, only three classes of drugs are routinely used, namely polyenes, azoles and echinocandins. Antifungal resistance toward all three antifungal drug classes frequently occurs in clinical settings. Compared with the broad range of literature on virulence and antifungal resistance of Candida species separately, only a small portion of studies examined the effect of resistance on virulence. These studies found that resistance to polyenes and echinocandins concluded in significant decrease in the virulence in different Candida species. Meanwhile, in some cases, resistance to azole type antifungals resulted in increased virulence depending on the species and isolates. These findings underline the importance of studies aiming to dissect the connections of virulence and resistance in Candida species.
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Affiliation(s)
- Flora Bohner
- HCEMM-USZ Fungal Pathogens Research Group, Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Csaba Papp
- HCEMM-USZ Fungal Pathogens Research Group, Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Attila Gácser
- HCEMM-USZ Fungal Pathogens Research Group, Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.,MTA-SZTE "Lendület" Mycobiome Research Group, University of Szeged, Szeged, Hungary
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3
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Kim HY, Baldelli S, Märtson AG, Stocker S, Alffenaar JW, Cattaneo D, Marriott DJE. Therapeutic Drug Monitoring of the Echinocandin Antifungal Agents: Is There a Role in Clinical Practice? A Position Statement of the Anti-Infective Drugs Committee of the International Association of Therapeutic Drug Monitoring and Clinical Toxicology. Ther Drug Monit 2022; 44:198-214. [PMID: 34654030 DOI: 10.1097/ftd.0000000000000931] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 09/01/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE Reduced exposure to echinocandins has been reported in specific patient populations, such as critically ill patients; however, fixed dosing strategies are still used. The present review examines the accumulated evidence supporting echinocandin therapeutic drug monitoring (TDM) and summarizes available assays and sampling strategies. METHODS A literature search was conducted using PubMed in December 2020, with search terms such as echinocandins, anidulafungin, caspofungin, micafungin, or rezafungin with pharmacology, pharmacokinetics (PKs), pharmacodynamics (PDs), drug-drug interactions, TDM, resistance, drug susceptibility testing, toxicity, adverse drug reactions, bioanalysis, chromatography, and mass spectrometry. Data on PD/PD (PK/PD) outcome markers, drug resistance, PK variability, drug-drug interactions, assays, and TDM sampling strategies were summarized. RESULTS Echinocandins demonstrate drug exposure-efficacy relationships, and maximum concentration/minimal inhibitory concentration ratio (Cmax/MIC) and area under the concentration-time curve/MIC ratio (AUC/MIC) are proposed PK/PD markers for clinical response. The relationship between drug exposure and toxicity remains poorly clarified. TDM could be valuable in patients at risk of low drug exposure, such as those with critical illness and/or obesity. TDM of echinocandins may also be useful in patients with moderate liver impairment, drug-drug interactions, hypoalbuminemia, and those undergoing extracorporeal membrane oxygenation, as these conditions are associated with altered exposure to caspofungin and/or micafungin. Assays are available to measure anidulafungin, micafungin, and caspofungin concentrations. A limited-sampling strategy for anidulafungin has been reported. CONCLUSIONS Echinocandin TDM should be considered in patients at known risk of suboptimal drug exposure. However, for implementing TDM, clinical validation of PK/PD targets is needed.
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Affiliation(s)
- Hannah Yejin Kim
- Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
- Westmead Hospital, Westmead, NSW, Australia
- Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Camperdown, NSW, Australia
| | - Sara Baldelli
- Unit of Clinical Pharmacology, Fatebenefratelli Sacco University Hospital, Milan, Italy
| | - Anne-Grete Märtson
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Sophie Stocker
- Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
- St Vincent's Clinical School, University of New South Wales, Kensington, NSW Australia; and
| | - Jan-Willem Alffenaar
- Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
- Westmead Hospital, Westmead, NSW, Australia
- Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Camperdown, NSW, Australia
| | - Dario Cattaneo
- Unit of Clinical Pharmacology, Fatebenefratelli Sacco University Hospital, Milan, Italy
- Gestione Ambulatoriale Politerapie (GAP) Outpatient Clinic, ASST Fatebenefratelli Sacco University Hospital, Milan, Italy
| | - Deborah J E Marriott
- St Vincent's Clinical School, University of New South Wales, Kensington, NSW Australia; and
- Department of Microbiology and Infectious Diseases, St. Vincent's Hospital, Darlinghurst, NSW, Australia
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Abstract
Pathogenic fungi have several mechanisms of resistance to antifungal drugs, driven by the genetic plasticity and versatility of their homeostatic responses to stressful environmental cues. We critically review the molecular mechanisms of resistance and cellular adaptations of pathogenic fungi in response to antifungals and discuss the factors contributing to such resistance. We offer suggestions for the translational and clinical research agenda of this rapidly evolving and medically important field. A better understanding of antifungal resistance should assist in developing better detection tools and inform optimal strategies for preventing and treating refractory mycoses in the future.
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Affiliation(s)
- Ronen Ben-Ami
- Infectious Diseases Department, Sackler School of Medicine, Tel Aviv University, Tel Aviv Sourasky Medical Center, 6 Weizmann, Tel Aviv 64239, Israel
| | - Dimitrios P Kontoyiannis
- Infectious Diseases, University of Texas M D Anderson Cancer Center, 1515 Holcombe, Houston, TX 77030, USA.
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Lamoth F, Lewis RE, Kontoyiannis DP. Role and Interpretation of Antifungal Susceptibility Testing for the Management of Invasive Fungal Infections. J Fungi (Basel) 2020; 7:jof7010017. [PMID: 33396870 PMCID: PMC7823995 DOI: 10.3390/jof7010017] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/18/2020] [Accepted: 12/23/2020] [Indexed: 11/16/2022] Open
Abstract
Invasive fungal infections (IFIs) are associated with high mortality rates and timely appropriate antifungal therapy is essential for good outcomes. Emerging antifungal resistance among Candida and Aspergillus spp., the major causes of IFI, is concerning and has led to the increasing incorporation of in vitro antifungal susceptibility testing (AST) to guide clinical decisions. However, the interpretation of AST results and their contribution to management of IFIs remains a matter of debate. Specifically, the utility of AST is limited by the delay in obtaining results and the lack of pharmacodynamic correlation between minimal inhibitory concentration (MIC) values and clinical outcome, particularly for molds. Clinical breakpoints for Candida spp. have been substantially revised over time and appear to be reliable for the detection of azole and echinocandin resistance and for outcome prediction, especially for non-neutropenic patients with candidemia. However, data are lacking for neutropenic patients with invasive candidiasis and some non-albicans Candida spp. (notably emerging Candida auris). For Aspergillus spp., AST is not routinely performed, but may be indicated according to the epidemiological context in the setting of emerging azole resistance among A. fumigatus. For non-Aspergillus molds (e.g., Mucorales, Fusarium or Scedosporium spp.), AST is not routinely recommended as interpretive criteria are lacking and many confounders, mainly host factors, seem to play a predominant role in responses to antifungal therapy. This review provides an overview of the pre-clinical and clinical pharmacodynamic data, which constitute the rationale for the use and interpretation of AST testing of yeasts and molds in clinical practice.
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Affiliation(s)
- Frederic Lamoth
- Infectious Diseases Service and Institute of Microbiology, University Hospital of Lausanne, Lausanne University, 1011 Lausanne, Switzerland;
| | - Russell E. Lewis
- Clinic of Infectious Diseases, S’Orsola-Malpighi Hospital, Department of Medical and Surgical Sciences, University of Bologna, 40126 Bologna, Italy;
| | - Dimitrios P. Kontoyiannis
- Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Correspondence: ; Tel.: +1-713-792-6237; Fax: +1-713-745-6839
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De Paula DCC, Leite EA, Araujo CM, Branquinho RT, Guimarães HN, Grabe-Guimarães A. Caspofungin Effects on Electrocardiogram of Mice: An Evaluation of Cardiac Safety. Cardiovasc Toxicol 2020; 21:93-105. [PMID: 32845461 DOI: 10.1007/s12012-020-09599-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 08/11/2020] [Indexed: 01/02/2023]
Abstract
Caspofungin is an echinocandin, exhibiting efficacy against most Candida species invasive infection. Its cardiotoxicity was reported in isolated rat heart and ventricular myocytes, but in vivo and clinical studies are insufficient. Our objective was to evaluate caspofungin in vivo cardiac effects using an efficacious dose against Candida albicans. Female Swiss mice were infected with C. albicans, and treated with caspofungin, 5 or 10 mg/kg, intraperitoneal along 5 days. Survival rate and colony-forming units (CFU) into vital organs were determined. For cardiac effects study, mice were treated with caspofungin 10 mg/kg, and electrocardiogram (ECG) signal was obtained on C. albicans-infected mice, single dose-treated, and uninfected mice treated along 5 days, both groups to measure ECG intervals. Besides, ECG was also obtained by telemetry on uninfected mice to evaluate heart rate variability (HRV) parameters. The MIC for caspofungin on the wild-type C. albicans SC5314 strain was 0.3 μg/ml, indicating the susceptible. Survival rate increased significantly in infected mice treated with caspofungin compared to mice treated with vehicle. None of the survived infected mice presented positive CFU after treatment with 10 mg/kg. C. albicans infection induced prolongation of QRS, QT, and QTc intervals; caspofungin did not alter this effect. Caspofungin induced increase of PR and an additional increase of QRS after 24 h of a single dose in infected mice. No significant alterations occurred in ECG intervals and HRV parameters of uninfected mice, after caspofungin treatment. Caspofungin showed in vivo cardiac relative safety maintaining its antifungal efficacy against C. albicans.
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Affiliation(s)
- Danielle Cristiane Correa De Paula
- Pharmaceutical Science Program (CiPharma), School of Pharmacy, Federal University of Ouro Preto, Campus Morro do Cruzeiro, s/n, Ouro Preto, Minas Gerais, 35400-000, Brazil
| | - Elaine Amaral Leite
- Department of Pharmaceutical Products, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Carolina Morais Araujo
- Pharmaceutical Science Program (CiPharma), School of Pharmacy, Federal University of Ouro Preto, Campus Morro do Cruzeiro, s/n, Ouro Preto, Minas Gerais, 35400-000, Brazil
| | - Renata Tupinambá Branquinho
- Pharmaceutical Science Program (CiPharma), School of Pharmacy, Federal University of Ouro Preto, Campus Morro do Cruzeiro, s/n, Ouro Preto, Minas Gerais, 35400-000, Brazil
| | - Homero Nogueira Guimarães
- Department of Electrical Engineering, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Andrea Grabe-Guimarães
- Pharmaceutical Science Program (CiPharma), School of Pharmacy, Federal University of Ouro Preto, Campus Morro do Cruzeiro, s/n, Ouro Preto, Minas Gerais, 35400-000, Brazil.
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Jiang L, Zheng L, Sun KA, Zhou P, Xu R, Gu J, Wei X. In vitro and in vivo evaluation of the antifungal activity of fluoxetine combined with antifungals against Candida albicans biofilms and oral candidiasis. BIOFOULING 2020; 36:537-548. [PMID: 32551919 DOI: 10.1080/08927014.2020.1777401] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 05/21/2020] [Accepted: 05/28/2020] [Indexed: 06/11/2023]
Abstract
Candida albicans biofilms are responsible for oral candidiasis. Fluoxetine is a widely used antidepressant, with certain anti-Candida activities. The antifungal activity of fluoxetine combined with various antifungals against C. albicans biofilms and oral candidiasis was evaluated in this study. The morphological change in the inhibition of fluoxetine on C. albicans biofilms was observed using SEM. The interactions between fluoxetine and antifungals against C. albicans biofilms were evaluated using microdilution checkerboard methods, FICI and the ΔE model. The synergistic combination was tested in vivo on the mice model of oral candidiasis. SEM imaging showed fluoxetine inhibited hyphal growth and biofilm formation. Fluoxetine combined with caspofungin exhibited synergistic effects against C. albicans biofilms. Antagonistic effects occurred when fluoxetine was combined with amphotericin B or terbinafine. Further, the fluoxetine combined with caspofungin significantly reduced the lesion score and CFU of C. albicans on the murine tongue (p < 0.05), and relieved oral candidiasis of the infected mice.
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Affiliation(s)
- Liuliu Jiang
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, China
- Department of Operative Dentistry and Endodontics, Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, China
| | - Linxia Zheng
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, China
- Department of Operative Dentistry and Endodontics, Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, China
| | - K Airui Sun
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, China
- Department of Operative Dentistry and Endodontics, Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, China
| | - Peng Zhou
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, China
- Department of Operative Dentistry and Endodontics, Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, China
| | - Rui Xu
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, China
- Department of Operative Dentistry and Endodontics, Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, China
| | - Jingyi Gu
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, China
- Department of Operative Dentistry and Endodontics, Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, China
| | - Xin Wei
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, China
- Department of Operative Dentistry and Endodontics, Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, China
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Basso V, Tran DQ, Schaal JB, Tran P, Eriguchi Y, Ngole D, Cabebe AE, Park AY, Beringer PM, Ouellette AJ, Selsted ME. Rhesus Theta Defensin 1 Promotes Long Term Survival in Systemic Candidiasis by Host Directed Mechanisms. Sci Rep 2019; 9:16905. [PMID: 31729441 PMCID: PMC6858451 DOI: 10.1038/s41598-019-53402-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/30/2019] [Indexed: 12/21/2022] Open
Abstract
Invasive candidiasis is an increasingly frequent cause of serious and often fatal infections in hospitalized and immunosuppressed patients. Mortality rates associated with these infections have risen sharply due to the emergence of multidrug resistant (MDR) strains of C. albicans and other Candida spp., highlighting the urgent need of new antifungal therapies. Rhesus theta (θ) defensin-1 (RTD-1), a natural macrocyclic antimicrobial peptide, was recently shown to be rapidly fungicidal against clinical isolates of MDR C. albicans in vitro. Here we found that RTD-1 was rapidly fungicidal against blastospores of fluconazole/caspofungin resistant C. albicans strains, and was active against established C. albicans biofilms in vitro. In vivo, systemic administration of RTD-1, initiated at the time of infection or 24 h post-infection, promoted long term survival in candidemic mice whether infected with drug-sensitive or MDR strains of C. albicans. RTD-1 induced an early (4 h post treatment) increase in neutrophils in naive and infected mice. In vivo efficacy was associated with fungal clearance, restoration of dysregulated inflammatory cytokines including TNF-α, IL-1β, IL-6, IL-10, and IL-17, and homeostatic reduction in numbers of circulating neutrophils and monocytes. Because these effects occurred using peptide doses that produced maximal plasma concentrations (Cmax) of less than 1% of RTD-1 levels required for in vitro antifungal activity in 50% mouse serum, while inducing a transient neutrophilia, we suggest that RTD-1 mediates its antifungal effects in vivo by host directed mechanisms rather than direct fungicidal activity. Results of this study suggest that θ-defensins represent a new class of host-directed compounds for treatment of disseminated candidiasis.
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Affiliation(s)
- Virginia Basso
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Dat Q Tran
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Oryn Therapeutics, Vacaville, California, United States of America
| | - Justin B Schaal
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Patti Tran
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Yoshihiro Eriguchi
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Department of Clinical Immunology and Rheumatology/Infectious DiseaseKyushu University HospitalDepartment of Medicine and Biosystemic ScienceKyushu University Graduate School of Medical Science, Fukuoka, Japan
| | - Diana Ngole
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Anthony E Cabebe
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - A Young Park
- Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, United States of America
| | - Paul M Beringer
- Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, United States of America
| | - André J Ouellette
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Norris Comprehensive Cancer Center of the University of Southern California, Los Angeles, California, United States of America
| | - Michael E Selsted
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America.
- Oryn Therapeutics, Vacaville, California, United States of America.
- Norris Comprehensive Cancer Center of the University of Southern California, Los Angeles, California, United States of America.
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10
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Prépost E, Tóth Z, Perlin DS, Gesztelyi R, Kardos G, Kovács R, Nagy F, Forgács L, Majoros L. Efficacy of humanized single large doses of caspofungin on the lethality and fungal tissue burden in a deeply neutropenic murine model against Candida albicans and Candida dubliniensis. Infect Drug Resist 2019; 12:1805-1814. [PMID: 31303773 PMCID: PMC6612285 DOI: 10.2147/idr.s198764] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 03/30/2019] [Indexed: 12/30/2022] Open
Abstract
Background Echinocandins are the first-line therapy for treatment of invasive Candida infections, but the mortality rate remains high, calling for novel strategies. Giving single larger echinocandin doses infrequently is an alternative regimen. Our aim was to test this novel approach in a neutropenic murine model. Materials and methods We compared the in vivo efficacy of single 10 and 40 mg/kg of caspofungin (2.5× and 10× the normal humanized dose) to that of the same cumulative doses of daily 2 and 8 mg/kg doses for 5 days against 2 each of wild-type C. albicans and C. dubliniensis as well as echinocandin resistant C. albicans. As a comparator, we tested daily 1 mg/kg amphotericin B. Results In lethality experiments, all caspofungin and amphotericin B regimens improved survival against wild-type C. albicans and C. dubliniensis clinical isolates (P<0.0001) and decreased the mean fungal kidney burdens of both species compared to controls. However, fungal kidney burden decreases were not always statistically significant, especially with single 10 or 40 mg/kg caspofungin doses. Amphotericin B was the least active drug against wild-type C. albicans. Against echinocandin-resistant strains, monodose 40 mg/kg caspofungin and 1 mg/kg of daily amphotericin B were effective in lethality experiments. Although, significant kidney CFU decreases were never found, except for amphotericin B against one of the isolates (p<0.05 at day 3 and p<0.001 at day 6). Conclusion Single 40 mg/kg caspofungin and 1 mg/kg amphotericin B proved to be effective in the lethality experiments against wild-type and echinocandin-resistant C. albicans and wild-type C. dubliniensis. This was not always shown regarding fungal tissue burdens. Single caspofungin doses used in mice in this study are attainable in humans as well, suggesting a potential place of this dosing strategy not only in prevention but also in curative treatment of evolved invasive Candida infections.
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Affiliation(s)
- Eszter Prépost
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Zoltán Tóth
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - David S Perlin
- Public Health Research Institute, New Jersey Medical School-Rutgers, Newark, NJ, USA
| | - Rudolf Gesztelyi
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Gábor Kardos
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Renátó Kovács
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Faculty of Pharmacy, University of Debrecen, Debrecen, Hungary
| | - Fruzsina Nagy
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Lajos Forgács
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - László Majoros
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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Wiederhold NP, Najvar LK, Jaramillo R, Olivo M, Pizzini J, Catano G, Patterson TF. Oral glucan synthase inhibitor SCY-078 is effective in an experimental murine model of invasive candidiasis caused by WT and echinocandin-resistant Candida glabrata. J Antimicrob Chemother 2019; 73:448-451. [PMID: 29177447 DOI: 10.1093/jac/dkx422] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 10/17/2017] [Indexed: 11/12/2022] Open
Abstract
Background Echinocandins are recommended as first-line therapy against Candida glabrata infections, although increased resistance to this class has been reported worldwide and they are currently only available for parenteral administration. SCY-078 is an investigational glucan synthase inhibitor that is orally available. Objectives To evaluate the in vivo efficacy of SCY-078 in an experimental model of invasive candidiasis due to WT and echinocandin-resistant C. glabrata isolates. Methods Neutropenic ICR mice were inoculated intravenously with a WT isolate (SCY-078 and caspofungin MICs 0.25 and 0.125 mg/L, respectively) or an echinocandin-resistant isolate (SCY-078 and caspofungin MICs 1 and 0.5 mg/L, respectively). Treatment with placebo, SCY-078 (8, 30 or 40 mg/kg orally every 12 h) or caspofungin (1 mg/kg by intraperitoneal injection once daily) began 24 h later. Kidney fungal burden was measured on day 8 post-inoculation. Results Significant reductions in kidney fungal burden were observed with 30 mg/kg SCY-078 against both isolates and with the 40 mg/kg dose against the echinocandin-resistant isolate. These results were supported by SCY-078 plasma concentration data at the higher doses, where levels above the MICs for both isolates were observed 12 h after the last oral dose. Reductions in fungal burden were also observed with caspofungin against the WT isolate, but not against the resistant isolate. Conclusions SCY-078 demonstrated in vivo efficacy against infections caused by both WT and echinocandin-resistant C. glabrata isolates in this experimental model. This orally available glucan synthase inhibitor has potential as a therapy against echinocandin-resistant C. glabrata infections.
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Affiliation(s)
- Nathan P Wiederhold
- University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Laura K Najvar
- University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,South Texas Veterans Health Care System, San Antonio, TX, USA
| | - Rosie Jaramillo
- University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,South Texas Veterans Health Care System, San Antonio, TX, USA
| | - Marcos Olivo
- University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,South Texas Veterans Health Care System, San Antonio, TX, USA
| | - Jason Pizzini
- University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Gabriel Catano
- University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,South Texas Veterans Health Care System, San Antonio, TX, USA
| | - Thomas F Patterson
- University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,South Texas Veterans Health Care System, San Antonio, TX, USA
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Spettel K, Barousch W, Makristathis A, Zeller I, Nehr M, Selitsch B, Lackner M, Rath PM, Steinmann J, Willinger B. Analysis of antifungal resistance genes in Candida albicans and Candida glabrata using next generation sequencing. PLoS One 2019; 14:e0210397. [PMID: 30629653 PMCID: PMC6328131 DOI: 10.1371/journal.pone.0210397] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 12/21/2018] [Indexed: 12/13/2022] Open
Abstract
Introduction/Objectives An increase in antifungal resistant Candida strains has been reported in recent years. The aim of this study was to detect mutations in resistance genes of azole-resistant, echinocandin-resistant or multi-resistant strains using next generation sequencing technology, which allows the analysis of multiple resistance mechanisms in a high throughput setting. Methods Forty clinical Candida isolates (16 C. albicans and 24 C. glabrata strains) with MICs for azoles and echinocandins above the clinical EUCAST breakpoint were examined. The genes ERG11, ERG3, TAC1 and GSC1 (FKS1) in C. albicans, as well as ERG11, CgPDR1, FKS1 and FKS2 in C. glabrata were sequenced. Results Fifty-four different missense mutations were identified, 13 of which have not been reported before. All nine echinocandin-resistant Candida isolates showed mutations in the hot spot (HS) regions of FKS1, FKS2 or GSC1. In ERG3 two homozygous premature stop codons were identified in two highly azole-resistant and moderately echinocandin-resistant C. albicans strains. Seven point mutations in ERG11 were determined in azole-resistant C. albicans whereas in azole-resistant C. glabrata, no ERG11 mutations were detected. In 10 out of 13 azole-resistant C. glabrata, 12 different potential gain-of-function mutations in the transcription factor CgPDR1 were verified, which are associated with an overexpression of the efflux pumps CDR1/2. Conclusion This study showed that next generation sequencing allows the thorough investigation of a large number of isolates more cost efficient and faster than conventional Sanger sequencing. Targeting different resistance genes and a large sample size of highly resistant strains allows a better determination of the relevance of the different mutations, and to differentiate between causal mutations and polymorphisms.
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Affiliation(s)
- Kathrin Spettel
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Barousch
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Athanasios Makristathis
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Iris Zeller
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Marion Nehr
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Brigitte Selitsch
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Michaela Lackner
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Peter-Michael Rath
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Joerg Steinmann
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- Institute of Clinical Hygiene, Medical Microbiology and Infectiology, Paracelsus Medical University, Nuremberg, Germany
| | - Birgit Willinger
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
- * E-mail:
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Cortés Hidalgo AP, Roa Dueñas OH, Méndez Fandiño YR, Álvarez Moreno CA. Opciones terapéuticas frente a especies de Candida resistentes a las equinocandinas. UNIVERSITAS MÉDICA 2018. [DOI: 10.11144/javeriana.umed59-2.cand] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
<p><strong>Introducción</strong>: La infección por levaduras del género <em>Candida</em> representa la causa más común de infecciones fúngicas invasivas. Su alta incidencia y la creciente resistencia frente a los azoles y, recientemente, a las equinocandinas ha generado la necesidad de buscar nuevas alternativas farmacológicas. Esta revisión presenta las principales alternativas farmacológicas en estudio frente a <em>Candida</em> resistente a equinocandinas. <strong>Métodos</strong>: Se buscó literatura referente al tema en las bases de datos Bireme, Clinical Key, Embase, Cochrane, Lilacs, Pubmed y Scopus. Se incluyeron 15 artículos en esta revisión. <strong>Resultados</strong>: Se exploran diferentes alternativas, incluyendo el aumento de dosis de las equinocandinas, su combinación con otros medicamentos y nuevos compuestos en estudio. <strong>Conclusión</strong>: A pesar de que las infecciones por <em>Candida</em> resistente a equinocandinas aún representan un desafío, dos alternativas farmacológicas se presentan como promisorias: la combinación con medicamentos existentes como el diclofenaco y nuevos compuestos que se encuentran actualmente en fase II de estudios clínicos.</p><p> </p>
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Kooshki P, Rezaei-Matehkolaei A, Mahmoudabadi AZ. The patterns of colonization and antifungal susceptibility of Candida, isolated from preterm neonates in Khorramabad, South West of Iran. J Mycol Med 2018. [PMID: 29530715 DOI: 10.1016/j.mycmed.2018.02.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
OBJECTIVE Usually, 7-20% of preterm neonates colonized by Candida species present invasive candidiasis. Candida albicans, and several non-albicans species cause invasive infection with C. albicans being the most dominant agent. In the last two decades, infection due to non-albicans have been increased dramatically due to their low sensitivity to antifungal drugs such as fluconazole. The aim of present study was to evaluate Candida colonization pattern and antifungal susceptibility among preterm neonates from Khorramabad, South west of Iran. MATERIALS AND METHODS Samples were collected from 80 preterm neonates, cultured on CHROMagar Candida and incubated at 37°C. All recovered isolates were primarily screened based on classical methods and identified by PCR-RFLP targeting the ITS-rDNA regions. Antifungal susceptibility testing of all isolates was performed according to the CLSI method against amphotericin B, caspofungin, itraconazole, fluconazole and voriconazole. RESULTS Totally 23 isolates of Candida species were recovered from 20 patients (female: male, 50:50) including, C. albicans (18), C. parapsilosis (2) and C. glabrata (1). Furthermore, the blood cultures from two patients were yielded C. albicans and C. parapsilosis so that patient with C. albicans died after five days. Generally, in this study, 9 (39.1%) isolates were resistant to amphotericin B including; 7 (30.4%) C. albicans and 2 (8.7%) C. parapsilosis. In addition, 2 (8.7%) and 4 (17.4%) isolates were also resistant to itraconazole and caspofungin, respectively. CONCLUSION In conclusion, Candida colonization among preterm neonates is still an important issue in hospitals. In addition, in spite of a significant amphotericin B resistant Candida, voriconazole, fluconazole, and itraconazole are valuable antifungals, due to fully sensitivity to Candida.
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Affiliation(s)
- P Kooshki
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Department of Medical Mycology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - A Rezaei-Matehkolaei
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Department of Medical Mycology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - A Z Mahmoudabadi
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Department of Medical Mycology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
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15
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Effects of Echinocandins in Combination with Nikkomycin Z against Invasive Candida albicans Bloodstream Isolates and the fks Mutants. Antimicrob Agents Chemother 2017; 61:AAC.00619-17. [PMID: 28827418 PMCID: PMC5655089 DOI: 10.1128/aac.00619-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Accepted: 08/10/2017] [Indexed: 11/20/2022] Open
Abstract
We evaluated the in vitro and in vivo effects of nikkomycin Z combined with an echinocandin (anidulafungin or micafungin) against two Candida albicans isolates and their lab-derived echinocandin-resistant fks mutants with FKS1 S645Y and FKS1 S645P. Synergistic effects were observed in all tested strains (fractional inhibitory concentration index, <0.5). Enhanced survival was observed in an immunocompromised murine model (log-rank test, P < 0.02). Our study demonstrated the therapeutic potential of nikkomycin Z-echinocandin combinations in managing echinocandin resistance.
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Arendrup MC, Patterson TF. Multidrug-Resistant Candida: Epidemiology, Molecular Mechanisms, and Treatment. J Infect Dis 2017; 216:S445-S451. [PMID: 28911043 DOI: 10.1093/infdis/jix131] [Citation(s) in RCA: 377] [Impact Index Per Article: 53.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Invasive Candida infections remain an important cause of morbidity and mortality, especially in hospitalized and immunocompromised or critically ill patients. A limited number of antifungal agents from only a few drug classes are available to treat patients with these serious infections. Resistance can be either intrinsic or acquired. Resistance mechanisms are not exchanged between Candida; thus, acquired resistance either emerges in response to an antifungal selection pressure in the individual patient or, more rarely, occur due to horizontal transmission of resistant strains between patients. Although multidrug resistance is uncommon, increasing reports of multidrug resistance to the azoles, echinocandins, and polyenes have occurred in several Candida species, most notably Candida glabrata and more recently Candida auris. Drivers are overall antifungal use, subtherapeutic drug levels at sites of infection/colonization, drug sequestration in the biofilm matrix, and, in the setting of outbreaks, suboptimal infection control. Moreover, recent research suggests that DNA mismatch repair gene mutations may facilitate acquisition of resistance mutations in C. glabrata specifically. Diagnosis of antifungal-resistant Candida infections is critical to the successful management of patients with these infections. Reduction of unnecessary use of antifungals via antifungal stewardship is critical to limit multidrug resistance emergence.
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Affiliation(s)
- Maiken Cavling Arendrup
- Unit of Mycology, Statens Serum Institut.,Department of Clinical Microbiology, Rigshospitalet.,Department of Clinical Medicine, University of Copenhagen, Denmark
| | - Thomas F Patterson
- Division of Infectious Diseases, San Antonio Center for Medical Mycology, UT Health San Antonio, and the South Texas Veterans Health Care System
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17
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Wiederhold NP. Echinocandin Resistance in Candida Species: a Review of Recent Developments. Curr Infect Dis Rep 2016; 18:42. [PMID: 27771864 DOI: 10.1007/s11908-016-0549-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The echinocandins are important agents for the treatment of invasive fungal infections, especially those caused by Candida species. However, as with other antimicrobial agents, microbiologic resistance to this class of antifungal agents has emerged and can result in clinical failure. Several studies have recently reported an increase in echinocandin resistance in Candida glabrata isolates at various medical centers in different geographic regions of the USA. Recent studies have also reported that many of these isolates may also be fluconazole resistant, leaving few treatment options available for clinicians to use in patients with invasive candidiasis caused by this species. Our understanding of the clinical relevance of specific point mutations within the FKS genes that cause echinocandin resistance and risk factors for the development of microbiologic resistance and clinical failure have also increased. The purpose of this review is to discuss echinocandin resistance in Candida species and recent reports that have increased our understanding of this growing clinical problem.
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Affiliation(s)
- Nathan P Wiederhold
- Department of Pathology, Fungus Testing Laboratory, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA.
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18
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Abstract
Invasive fungal infections are an important infection concern for patients with underlying immunosuppression. Antifungal therapy is a critical component of patient care, but therapeutic choices are limited due to few drug classes. Antifungal resistance, especially among Candida species, aggravates the problem. The echinocandin drugs (micafungin, anidulafungin, and caspofungin) are the preferred choice to treat a range of candidiasis. They target the fungal-specific enzyme glucan synthase, which is responsible for the biosynthesis of a major cell wall polymer. Therapeutic failure involves acquisition of resistance, although it is a rare event among most Candida species. However, in some settings, higher-level resistance has been reported among Candida glabrata, which is also frequently resistant to azole drugs, resulting in difficult-to-treat multidrug-resistant strains. The mechanism of echinocandin resistance involves amino acid changes in "hot spot" regions of FKS-encoded subunits of glucan synthase, which decreases the sensitivity of enzyme to drug, resulting in higher minimum inhibitory concentration values. The cellular processes promoting the formation of resistant FKS strains involve complex stress response pathways that yield a variety of adaptive compensatory genetic responses. Standardized broth microdilution techniques can be used to distinguish FKS mutant strains from wild type, but testing C. glabrata with caspofungin should be approached cautiously. Finally, clinical factors that promote echinocandin resistance include prophylaxis, host reservoirs including biofilms in the gastrointestinal tract, and intra-abdominal infections. An understanding of clinical and molecular factors that promote echinocandin resistance is critical to develop better diagnostic tools and therapeutic strategies to overcome resistance.
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Affiliation(s)
- David S Perlin
- Public Health Research Institute, New Jersey Medical School-Rutgers Biomedical and Health Sciences, Newark
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19
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Hope W, Drusano GL, Rex JH. Pharmacodynamics for antifungal drug development: an approach for acceleration, risk minimization and demonstration of causality. J Antimicrob Chemother 2016; 71:3008-3019. [PMID: 27494925 DOI: 10.1093/jac/dkw298] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The treatment of invasive fungal diseases constitutes a significant unmet medical need. There are relatively few antifungal agents in clinical development and a paucity of novel targets. Morbidity and mortality remain high and clinical outcomes are compromised by submaximal efficacy, emergence of drug resistance and drug-related toxicity. Thus, new antifungal agents are urgently required. A deep understanding of exposure-response relationships underpins the development of safe and effective clinical regimens of any therapeutic agent. Pharmacokinetics (PK) and pharmacodynamics (PD) is increasingly recognized as a vital tool in the development of new antimicrobial agents and maximizes the probability that the right dose will be studied the first time. There is currently no information or agreement as to what constitutes an adequate PK/PD package for the development of a new antifungal agent. This review provides a summary of the achievements of antifungal PK/PD for the treatment of invasive candidiasis, invasive aspergillosis and cryptococcal meningoencephalitis, and outlines the necessary components of a PK/PD package for a new antifungal agent. Such information is critical for the accelerated and efficient development of new agents and enables improved clinical outcomes to be secured.
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Affiliation(s)
| | | | - John H Rex
- AstraZeneca Pharmaceuticals, Waltham, MA, USA.,F2G Pharmaceuticals, Eccles, Cheshire, UK
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20
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Zhao Y, Perez WB, Jiménez-Ortigosa C, Hough G, Locke JB, Ong V, Bartizal K, Perlin DS. CD101: a novel long-acting echinocandin. Cell Microbiol 2016; 18:1308-16. [PMID: 27354115 PMCID: PMC5096055 DOI: 10.1111/cmi.12640] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 06/22/2016] [Accepted: 06/25/2016] [Indexed: 01/05/2023]
Abstract
CD101 is a novel echinocandin drug being developed to treat severe fungal infections including invasive candidiasis. We have performed a series of studies to evaluate the antifungal properties of CD101 against both echinocandin‐susceptible and ‐resistant Candida strains. Antifungal susceptibility testing performed on a collection of 95 Candida strains including 30 caspofungin‐resistant isolates containing fks mutations demonstrated comparable antifungal potency of CD101 relative to micafungin (MCF) across different Candida species. Comparable kinetic inhibition of glucan synthase activity was also observed for CD101 and MCF on both wild‐type (WT) and resistant fks mutant Candida strains. Similarly, both drugs yielded nearly identical values for a mutant prevention concentration. In a murine model of invasive candidiasis, CD101 displayed better or at least comparable efficacy relative to MCF in treating WT or fks mutant Candida albicans. An exceptional long‐lived pharmacokinetic profile was observed in mice following a single dose of CD101. Collectively, CD101 has great potential not only in treating invasive Candida infections but also in preventing emergence of resistance to currently approved echinocandin drugs.
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Affiliation(s)
- Yanan Zhao
- Public Health Research Institute, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, NJ, USA
| | - Winder B Perez
- Public Health Research Institute, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, NJ, USA
| | - Cristina Jiménez-Ortigosa
- Public Health Research Institute, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, NJ, USA
| | | | | | - Voon Ong
- Cidara Therapeutics, Inc., San Diego, CA, USA
| | | | - David S Perlin
- Public Health Research Institute, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, NJ, USA
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Thi Minh HP, Thanh HN, Tuan QN, Tran Le A, Thanh TB. Development and Evaluation of Antifungal in vivo of Liposomal Amphotericin B. ACTA ACUST UNITED AC 2015. [DOI: 10.3923/ijbc.2015.283.294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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22
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Abstract
Fungal infections due to Candida and Aspergillus species cause extensive morbidity and mortality, especially among immunosuppressed patients, and antifungal therapy is critical to patient management. Yet only a few drug classes are available to treat invasive fungal diseases, and this problem is compounded by the emergence of antifungal resistance. Echinocandin drugs are the preferred choice to treat candidiasis. They are the first cell wall-active agents and target the fungal-specific enzyme glucan synthase, which catalyzes the biosynthesis of β-1,3-glucan, a key cell wall polymer. Therapeutic failures occur rarely among common Candida species, with the exception of Candida glabrata, which is frequently multidrug resistant. Echinocandin resistance in susceptible species is always acquired during therapy. The mechanism of resistance involves amino acid changes in hot-spot regions of Fks subunits of glucan synthase, which decrease the sensitivity of the enzyme to drug. Cellular stress response pathways lead to drug adaptation, which promotes the formation of resistant fks strains. Clinical factors promoting echinocandin resistance include empiric therapy, prophylaxis, gastrointestinal reservoirs, and intra-abdominal infections. A better understanding of the echinocandin-resistance mechanism, along with cellular and clinical factors promoting resistance, will facilitate more effective strategies to overcome and prevent echinocandin resistance.
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Affiliation(s)
- David S Perlin
- New Jersey Medical School, Rutgers Biomedical and Health Sciences, Public Health Research Institute, Newark, New Jersey
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23
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Abstract
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.
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Affiliation(s)
- David S Perlin
- Public Health Research Institute, Rutgers Biomedical and Health Sciences, New Jersey Medical School, 185 S Orange Ave, Newark, NJ 07103, USA
| | - Erika Shor
- Public Health Research Institute, Rutgers Biomedical and Health Sciences, New Jersey Medical School, 185 S Orange Ave, Newark, NJ 07103, USA
| | - Yanan Zhao
- Public Health Research Institute, Rutgers Biomedical and Health Sciences, New Jersey Medical School, 185 S Orange Ave, Newark, NJ 07103, USA
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Coad BR, Lamont-Friedrich SJ, Gwynne L, Jasieniak M, Griesser SS, Traven A, Peleg AY, Griesser HJ. Surface coatings with covalently attached caspofungin are effective in eliminating fungal pathogens. J Mater Chem B 2015; 3:8469-8476. [DOI: 10.1039/c5tb00961h] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In this work we have prepared surface coatings formulated with the antifungal drug caspofungin, an approved pharmaceutical lipopeptide compound of the echinocandin drug class.
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Affiliation(s)
- Bryan R. Coad
- Mawson Institute
- University of South Australia
- Australia
| | | | - Lauren Gwynne
- Mawson Institute
- University of South Australia
- Australia
- The University of Bath
- UK
| | | | | | - Ana Traven
- Department of Biochemistry and Molecular Biology
- Monash University
- Clayton
- Australia
| | - Anton Y. Peleg
- Department of Infectious Diseases
- The Alfred Hospital and Monash University
- Melbourne
- Australia
- Department of Microbiology
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The novel arylamidine T-2307 maintains in vitro and in vivo activity against echinocandin-resistant Candida albicans. Antimicrob Agents Chemother 2014; 59:1341-3. [PMID: 25451054 DOI: 10.1128/aac.04228-14] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We evaluated the in vitro and in vivo activities of the investigational arylamidine T-2307 against echinocandin-resistant Candida albicans. T-2307 demonstrated potent in vitro activity, and daily subcutaneous doses between 0.75 and 6 mg/kg of body weight significantly improved survival and reduced fungal burden compared to placebo control and caspofungin (10 mg/kg/day) in mice with invasive candidiasis caused by an echinocandin-resistant strain. Thus, T-2307 may have potential use in the treatment of echinocandin-resistant C. albicans infections.
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Cowen LE, Sanglard D, Howard SJ, Rogers PD, Perlin DS. Mechanisms of Antifungal Drug Resistance. Cold Spring Harb Perspect Med 2014; 5:a019752. [PMID: 25384768 DOI: 10.1101/cshperspect.a019752] [Citation(s) in RCA: 336] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
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.
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Affiliation(s)
- Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Dominique Sanglard
- University of Lausanne and University Hospital Center, Institute of Microbiology, 1011 Lausanne, Switzerland
| | - Susan J Howard
- University of Liverpool, Sherrington Building, Ashton Street, Liverpool L69 3GE, United Kingdom
| | - P David Rogers
- College of Pharmacy, The University of Tennessee Health Science Center, Memphis, Tennessee 38163
| | - David S Perlin
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey 07103
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The investigational agent E1210 is effective in treatment of experimental invasive candidiasis caused by resistant Candida albicans. Antimicrob Agents Chemother 2014; 59:690-2. [PMID: 25331706 DOI: 10.1128/aac.03944-14] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The in vitro and in vivo activity of the inositol acyltransferase inhibitor E1210 was evaluated against echinocandin-resistant Candida albicans. E1210 demonstrated potent in vitro activity, and in mice with invasive candidiasis caused by echinocandin-resistant C. albicans, oral doses of 10 and 40 mg E1210/kg of body weight twice daily significantly improved survival and reduced fungal burden compared to those of controls and mice treated with caspofungin (10 mg/kg/day). These results demonstrate the potential use of E1210 against resistant C. albicans infections.
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Perlin DS. Echinocandin resistance, susceptibility testing and prophylaxis: implications for patient management. Drugs 2014; 74:1573-85. [PMID: 25255923 PMCID: PMC4201113 DOI: 10.1007/s40265-014-0286-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
This article addresses the emergence of echinocandin resistance among Candida species, mechanisms of resistance, factors that promote resistance and confounding issues surrounding standard susceptibility testing. Fungal infections remain a significant cause of global morbidity and mortality, especially among patients with underlying immunosupression. Antifungal therapy is a critical component of patient management for acute and chronic diseases. Yet, therapeutic choices are limited due to only a few drug classes available to treat systemic disease. Moreover, the problem is exacerbated by the emergence of antifungal resistance, which has resulted in difficult to manage multidrug resistant strains. Echinocandin drugs are now the preferred choice to treat a range of candidiasis. These drugs target and inhibit the fungal-specific enzyme glucan synthase, which is responsible for the biosynthesis of a key cell wall polymer. Therapeutic failures involving acquisition of resistance among susceptible organisms like Candida albicans is largely a rare event. However, in recent years, there is an alarming trend of increased resistance among strains of Candida glabrata, which in many cases are also resistant to azole drugs. Echinocandin resistance is always acquired during therapy and the mechanism of resistance is well established to involve amino acid changes in "hot-spot" regions of the Fks subunits carrying the catalytic portion of glucan synthase. These changes significantly decrease the sensitivity of the enzyme to drug resulting in higher MIC values. A range of drug responses, from complete to partial refractory response, is observed depending on the nature of the amino acid substitution, and clinical responses are recapitulated in pharmacodynamic models of infection. The cellular processes promoting the formation of resistant Fks strains involve complex stress response pathways, which yield a variety of adaptive compensatory genetic responses. Stress-adapted cells become drug tolerant and can form stable drug resistant FKS mutations with continued drug exposure. A major concern for resistance detection is that classical broth microdilution techniques show significant variability among clinical microbiology laboratories for certain echinocandin drugs and Candida species. The consequence is that susceptible strains are misclassified according to established clinical breakpoints, and this has led to confusion in the field. Clinical factors that appear to promote echinocandin resistance include the expanding use of antifungal agents for empiric therapy and prophylaxis. Furthermore, host reservoirs such as biofilms in the gastrointestinal tract or intra-abdominal infections can seed development of resistant organisms during therapy. A fundamental understanding of the primary molecular resistance mechanism, along with cellular and clinical factors that promote resistance emergence, is critical to develop better diagnostic tools and therapeutic strategies to overcome and prevent echinocandin resistance.
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Affiliation(s)
- David S Perlin
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA,
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In vitro analysis of finasteride activity against Candida albicans urinary biofilm formation and filamentation. Antimicrob Agents Chemother 2014; 58:5855-62. [PMID: 25049253 DOI: 10.1128/aac.03137-14] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Candida albicans is the 3rd most common cause of catheter-associated urinary tract infections, with a strong propensity to form drug-resistant catheter-related biofilms. Due to the limited efficacy of available antifungals against biofilms, drug repurposing has been investigated in order to identify novel agents with activities against fungal biofilms. Finasteride is a 5-α-reductase inhibitor commonly used for the treatment of benign prostatic hyperplasia, with activity against human type II and III isoenzymes. We analyzed the Candida Genome Database and identified a C. albicans homolog of type III 5-α-reductase, Dfg10p, which shares 27% sequence identity and 41% similarity to the human type III 5-α-reductase. Thus, we investigated finasteride for activity against C. albicans urinary biofilms, alone and in combination with amphotericin B or fluconazole. Finasteride alone was highly effective in the prevention of C. albicans biofilm formation at doses of ≥16 mg/liter and the treatment of preformed biofilms at doses of ≥128 mg/liter. In biofilm checkerboard analyses, finasteride exhibited synergistic activity in the prevention of biofilm formation in a combination of 4 mg/liter finasteride with 2 mg/liter fluconazole. Finasteride inhibited filamentation, thus suggesting a potential mechanism of action. These results indicate that finasteride alone is highly active in the prevention of C. albicans urinary biofilms in vitro and has synergistic activity in combination with fluconazole. Further investigation of the clinical utility of finasteride in the prevention of urinary candidiasis is warranted.
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Lackner M, Tscherner M, Schaller M, Kuchler K, Mair C, Sartori B, Istel F, Arendrup MC, Lass-Flörl C. Positions and numbers of FKS mutations in Candida albicans selectively influence in vitro and in vivo susceptibilities to echinocandin treatment. Antimicrob Agents Chemother 2014; 58:3626-35. [PMID: 24733467 PMCID: PMC4068606 DOI: 10.1128/aac.00123-14] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 04/06/2014] [Indexed: 02/05/2023] Open
Abstract
Candidemia is the fourth most common kind of microbial bloodstream infection, with Candida albicans being the most common causative species. Echinocandins are employed as the first-line treatment for invasive candidiasis until the fungal species is determined and confirmed by clinical diagnosis. Echinocandins block the FKS glucan synthases responsible for embedding β-(1,3)-d-glucan in the cell wall. The increasing use of these drugs has led to the emergence of antifungal resistance, and elevated MICs have been associated with single-residue substitutions in specific hot spot regions of FKS1 and FKS2. Here, we show for the first time the caspofungin-mediated in vivo selection of a double mutation within one allele of the FKS1 hot spot 1 in a clinical isolate. We created a set of isogenic mutants and used a hematogenous murine model to evaluate the in vivo outcomes of echinocandin treatment. Heterozygous and homozygous double mutations significantly enhance the in vivo resistance of C. albicans compared with the resistance seen with heterozygous single mutations. The various FKS1 hot spot mutations differ in the degree of their MIC increase, substance-dependent in vivo response, and impact on virulence. Our results demonstrate that echinocandin EUCAST breakpoint definitions correlate with the in vivo response when a standard dosing regimen is used but cannot predict the in vivo response after a dose escalation. Moreover, patients colonized by a C. albicans strain with multiple mutations in FKS1 have a higher risk for therapeutic failure.
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Affiliation(s)
- M Lackner
- Division of Hygiene and Medical Microbiology, Innsbruck Medical University, Innsbruck, Austria
| | - M Tscherner
- Medical University of Vienna, Department for Medical Biochemistry, Max F. Perutz Laboratories, Vienna, Austria
| | - M Schaller
- Universitäts-Hautklinik Tübingen, Eberhard-Karls-Universität Tübingen, Tübingen, Germany
| | - K Kuchler
- Medical University of Vienna, Department for Medical Biochemistry, Max F. Perutz Laboratories, Vienna, Austria
| | - C Mair
- Division of Hygiene and Medical Microbiology, Innsbruck Medical University, Innsbruck, Austria
| | - B Sartori
- Division of Hygiene and Medical Microbiology, Innsbruck Medical University, Innsbruck, Austria
| | - F Istel
- Medical University of Vienna, Department for Medical Biochemistry, Max F. Perutz Laboratories, Vienna, Austria
| | - M C Arendrup
- Unit of Mycology, Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark
| | - C Lass-Flörl
- Division of Hygiene and Medical Microbiology, Innsbruck Medical University, Innsbruck, Austria
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Shao J, Wang T, Yan Y, Shi G, Cheng H, Wu D, Wang C. Matrine reduces yeast-to-hypha transition and resistance of a fluconazole-resistant strain of Candida albicans. J Appl Microbiol 2014; 117:618-26. [PMID: 24860982 DOI: 10.1111/jam.12555] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Revised: 05/15/2014] [Accepted: 05/22/2014] [Indexed: 11/30/2022]
Abstract
AIMS To evaluate the potential effect of matrine on reducing the growth of hypha and lowering the resistance of a fluconazole-resistant colony of Candida albicans. METHODS AND RESULTS Candida albicans SC5314 and a fluconazole-resistant C. albicans 215 were used. As for C. albicans SC5314, minimal inhibitory concentration (MIC(80)) and effective concentration (EC(50)) were determined, 1 mg ml(-1) matrine could inhibit nearly 80% of planktonic growth by inverted microscope, 2 mg ml(-1) matrine suppressed 50% of metabolic activity of biofilm by XTT assay, vanishing hypha could be observed on spider agar containing 2 mg ml(-1) matrine, the expressions of three hypha-related genes, namely ALS 3, SUN 41 and PBS 2, were suppressed by 29, 45 and 61% by 2 mg ml(-1) matrine. Also, matrine could lower the resistance of C. albicans 215, in either the free-floating form or the biofilm phenotype. CONCLUSIONS Matrine had favourable antifungal potential and might be able to reverse the fluconazole resistance of clinical isolates at relatively high concentration. The anti-candidal performance of matrine could be tightly associated with yeast-to-hypha transition proved by spider agar test and qRT-PCR. SIGNIFICANCE AND IMPACT OF STUDY More efforts are needed to find new antifungal agents. Matrine could be a potential candidate to fight against Candida-related infections by regulating yeast-to-hypha transition.
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Affiliation(s)
- J Shao
- Laboratory of Microbiology and Immunology, School of Chinese and Western Integrative Medicine, Anhui University of Chinese Medicine, Hefei, China
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Zare B, Sepehrizadeh Z, Faramarzi MA, Soltany-Rezaee-Rad M, Rezaie S, Shahverdi AR. Antifungal activity of biogenic tellurium nanoparticles againstCandida albicansand its effects onsqualene monooxygenasegene expression. Biotechnol Appl Biochem 2014; 61:395-400. [DOI: 10.1002/bab.1180] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Accepted: 10/28/2013] [Indexed: 01/10/2023]
Affiliation(s)
- Bijan Zare
- Department of Pharmaceutical Biotechnology; Faculty of Pharmacy and Biotechnology Research Center, Tehran University of Medical Sciences; Tehran Iran
| | - Zargham Sepehrizadeh
- Department of Pharmaceutical Biotechnology; Faculty of Pharmacy and Biotechnology Research Center, Tehran University of Medical Sciences; Tehran Iran
| | - Mohammad Ali Faramarzi
- Department of Pharmaceutical Biotechnology; Faculty of Pharmacy and Biotechnology Research Center, Tehran University of Medical Sciences; Tehran Iran
| | - Mohammad Soltany-Rezaee-Rad
- Department of Pharmaceutical Biotechnology; Faculty of Pharmacy and Biotechnology Research Center, Tehran University of Medical Sciences; Tehran Iran
| | - Sassan Rezaie
- Department of Medical Biotechnology; School of Advanced Medical Technologies, Tehran University of Medical Sciences; Tehran Iran
| | - Ahmad Reza Shahverdi
- Department of Pharmaceutical Biotechnology; Faculty of Pharmacy and Biotechnology Research Center, Tehran University of Medical Sciences; Tehran Iran
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Kovács R, Gesztelyi R, Berényi R, Domán M, Kardos G, Juhász B, Majoros L. Killing rates exerted by caspofungin in 50 % serum and its correlation with in vivo efficacy in a neutropenic murine model against Candida krusei and Candida inconspicua. J Med Microbiol 2013; 63:186-194. [PMID: 24184471 DOI: 10.1099/jmm.0.066381-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Killing rates (K) of 1-32 µg ml(-1) caspofungin were determined in RPMI-1640 and in 50 % serum using time-kill methodology against three Candida krusei (MICs of all three isolates 0.25 µg ml(-1) in RPMI-1640 and 2 µg ml(-1) in serum) and three Candida inconspicua clinical isolates (MIC ranges 0.06-0.12 µg ml(-1) in RPMI-1640 and 0.25-0.5 µg ml(-1) in serum), against C. krusei ATCC 6258 and against one C. krusei isolate that was resistant to echinocandins (MIC 8 µg ml(-1) in RPMI-1640 and 32 µg ml(-1) in serum). In RPMI-1640, the highest mean K values were observed at 4 (-1.05 h(-1)) and 16 (-0.27 h(-1)) μg ml(-1) caspofungin for C. krusei and C. inconspicua clinical isolates, respectively. In 50 % serum, mean K value ranges at 1-32 and 4-32 µg ml(-1) concentrations for C. inconspicua and C. krusei were -1.12 to -1.44 and -0.42 to -0.57 h(-1), respectively. While K values against C. krusei in RPMI-1640 and 50 % serum were comparable, serum significantly increased the killing rate against C. inconspicua (P<0.0003 for all tested concentrations). In a neutropenic murine model, daily caspofungin at 1, 2, 3, 5 and 15 mg kg(-1) significantly decreased the fungal tissue burden of C. inconspicua in the kidneys (P<0.05-0.001). Against C. krusei, doses of 3, 5 and 15 mg kg(-1) caspofungin were effective (P<0.05-0.01). All effective doses were comparably efficacious for both species. Only the highest 15 mg kg(-1) caspofungin dose was effective even against the echinocandin-resistant C. krusei isolate. In 50 % serum, killing was concentration independent at effective concentrations (≥4 and ≥1 µg ml(-1) for C. krusei and C. inconspicua, respectively), suggesting that the efficacy of dose escalation is questionable. These in vitro results were also supported by the murine model.
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Affiliation(s)
- Renátó Kovács
- Department of Medical Microbiology, Medical and Health Science Center, University of Debrecen, Hungary
| | - Rudolf Gesztelyi
- Department of Pharmacology and Pharmacodynamics, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
| | - Réka Berényi
- Department of Medical Microbiology, Medical and Health Science Center, University of Debrecen, Hungary
| | - Marianna Domán
- Department of Medical Microbiology, Medical and Health Science Center, University of Debrecen, Hungary
| | - Gábor Kardos
- Department of Medical Microbiology, Medical and Health Science Center, University of Debrecen, Hungary
| | - Béla Juhász
- Department of Pharmacology and Pharmacodynamics, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
| | - László Majoros
- Department of Medical Microbiology, Medical and Health Science Center, University of Debrecen, Hungary
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Anidulafungin versus caspofungin in a mouse model of candidiasis caused by anidulafungin-susceptible Candida parapsilosis isolates with different degrees of caspofungin susceptibility. Antimicrob Agents Chemother 2013; 58:229-36. [PMID: 24145540 DOI: 10.1128/aac.01025-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Candida parapsilosis isolates occasionally display resistance in vitro to echinocandins and cause breakthrough infections to echinocandins. The degree of the in vivo cross-resistance among echinocandins and the fitness loss associated with caspofungin (CAS) resistance of C. parapsilosis are not well studied. We compared the activities of CAS and anidulafungin (ANF), each given at 2 dosing schedules (high dose or low dose) in a nonneutropenic mouse model of invasive candidiasis (IC) caused by ANF-susceptible isolates of C. parapsilosis with different degrees of susceptibility to CAS (CAS resistant [CAS-R], MIC, >16 mg/liter; CAS intermediate [CAS-I], MIC, 4 mg/liter; and CAS susceptible [CAS-S], MIC, 2 mg/liter). We analyzed tissue fungal burden, histopathology, and weight loss patterns. Increasing CAS resistance was associated with reduced virulence of C. parapsilosis isolates (mortality rates for CAS-S versus CAS-I versus CAS-R, 100% versus 11.1% versus 0%, respectively; P < 0.001). High doses of either echinocandin were active against infection with the CAS-I isolate when assessed by fungal burden reduction and weight gain. In contrast to CAS-S and CAS-I isolates, there was no reduction in fungal burden in mice infected with the CAS-R isolate following treatment with either echinocandin, each given at a high or low dose. Nevertheless, mice infected with the CAS-R isolate had reduced disease severity following echinocandin treatment, suggesting that echinocandins have activity in vivo, even against echinocandin-resistant strains. A complex interplay of residual echinocandin activity, decreased virulence, and/or fitness of isolates with altered cell wall and possible immunomodulatory effects can be encountered in vivo during infection with CAS-resistant C. parapsilosis isolates.
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Drew RH, Townsend ML, Pound MW, Johnson SW, Perfect JR. Recent advances in the treatment of life-threatening, invasive fungal infections. Expert Opin Pharmacother 2013; 14:2361-74. [DOI: 10.1517/14656566.2013.838217] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Mavridou E, Meletiadis J, Jancura P, Abbas S, Arendrup MC, Melchers WJG, Heskes T, Mouton JW, Verweij PE. Composite survival index to compare virulence changes in azole-resistant Aspergillus fumigatus clinical isolates. PLoS One 2013; 8:e72280. [PMID: 23991080 PMCID: PMC3753310 DOI: 10.1371/journal.pone.0072280] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 07/15/2013] [Indexed: 11/18/2022] Open
Abstract
Understanding resistance to antifungal agents in Aspergillus fumigatus is of increasing importance for the treatment of invasive infections in immunocompromised patients. Although a number of molecular resistance mechanisms are described in detail, the potential accompanying virulence changes and impact on clinical outcome have had little attention. We developed a new measure of survival, the composite survival index (CSI) to use as a measure of the virulence properties of A. fumigatus. Using a novel mathematical model we found a strong correlation between the in vitro growth characteristics and virulence in vivo expressed as CSI. Our model elucidates how three critical parameters (the lag phase (τ), decay constant (λ), and growth rate (ν)) interact with each other resulting in a CSI that correlated with virulence. Hence, strains with a long lag phase and high decay constant were less virulent in a murine model of invasive aspergillosis, whereas high virulence for isolates with a high CSI was associated in vitro with rapid growth and short lag phases. Resistant isolates with cyp51A mutations, which account for the majority of azole resistant aspergillosis cases, did not show a lower virulence compared to azole-susceptible isolates. In contrast, the CSI index revealed that a non-cyp51A-mediated resistance mechanism was associated with a dramatic decrease in CSI. Because of its predictive value, the mathematical model developed may serve to explore strain characteristics in vitro to predict virulence in vivo and significantly reduce the number of experimental animals required in such studies. The proposed measure of survival, the CSI can be used more in a general form in survival studies to explore optimal treatment options.
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Affiliation(s)
- Eleftheria Mavridou
- Department of Medical Microbiology, Nijmegen Institute for Infection, Inflammation and Immunity, Nijmegen, The Netherlands
- Nijmegen Institute for Infection, Inflammation and Immunity, Nijmegen, The Netherlands
- * E-mail: (EM); (PEV)
| | - Joseph Meletiadis
- Laboratory for Clinical Microbiology, Attikon University General Hospital, Athens, Greece
| | - Pavol Jancura
- Institute for Computing and Information Sciences, Faculty of Science, Radboud University, Nijmegen, The Netherlands
| | - Saiden Abbas
- Institute for Computing and Information Sciences, Faculty of Science, Radboud University, Nijmegen, The Netherlands
| | - Maiken C. Arendrup
- Department of Microbiological Surveillance and Research, Statens Serum Institut, Copenhagen, Denmark
| | - Willem J. G. Melchers
- Department of Medical Microbiology, Nijmegen Institute for Infection, Inflammation and Immunity, Nijmegen, The Netherlands
- Nijmegen Institute for Infection, Inflammation and Immunity, Nijmegen, The Netherlands
| | - Tom Heskes
- Institute for Computing and Information Sciences, Faculty of Science, Radboud University, Nijmegen, The Netherlands
| | - Johan W. Mouton
- Department of Medical Microbiology, Nijmegen Institute for Infection, Inflammation and Immunity, Nijmegen, The Netherlands
- Nijmegen Institute for Infection, Inflammation and Immunity, Nijmegen, The Netherlands
| | - Paul E. Verweij
- Department of Medical Microbiology, Nijmegen Institute for Infection, Inflammation and Immunity, Nijmegen, The Netherlands
- Nijmegen Institute for Infection, Inflammation and Immunity, Nijmegen, The Netherlands
- * E-mail: (EM); (PEV)
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Eschenauer GA, Carver PL. The Evolving Role of Antifungal Susceptibility Testing. Pharmacotherapy 2013; 33:465-75. [DOI: 10.1002/phar.1233] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
| | - Peggy L. Carver
- University of Pittsburgh Medical Center; Pittsburgh; Pennsylvania
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38
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Animal Models In Mycology: What Have We Learned Over The Past 30 Years. CURRENT FUNGAL INFECTION REPORTS 2012. [DOI: 10.1007/s12281-012-0126-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Kuper KM, Coyle EA, Wanger A. Antifungal Susceptibility Testing: A Primer for Clinicians. Pharmacotherapy 2012; 32:1112-22. [DOI: 10.1002/phar.1146] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Kristi M. Kuper
- Department of Quality Services; Cardinal Health; Houston; Texas
| | | | - Audrey Wanger
- Department of Pathology; University of Texas Medical School; Houston; Texas
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40
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Beyda ND, Lewis RE, Garey KW. Echinocandin Resistance in Candida Species: Mechanisms of Reduced Susceptibility and Therapeutic Approaches. Ann Pharmacother 2012; 46:1086-96. [DOI: 10.1345/aph.1r020] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE: To summarize published data regarding mechanisms of reduced echinocandin susceptibility in Candida spp., the impact of echinocandin resistance on the fitness and virulence of Candida isolates, and current and future treatment approaches. DATA SOURCES: A search of MEDLINE databases (1966-September 2011) was conducted. STUDY SELECTION AND DATA EXTRACTION: Databases were searched using the terms echinocandin, resistance, and Candida. Citations from publications were reviewed for additional references. DATA SYNTHESIS: Echinocandins have in vitro activity against most Candida spp. and are first-line agents in the treatment of candidemia. However, case reports describing echinocandin treatment failure due to resistant isolates have been published. Reduced echinocandin susceptibility has been shown to occur via 3 main mechanisms: (1) adaptive stress responses, which result in elevated cell wall chitin content and paradoxical growth in vitro at supra minimum inhibitory concentrations (MICs); (2) acquired FKS mutations, which confer reduced glucan synthase sensitivity, elevated MICs, and are associated with clinical failure; and (3) intrinsic FKS mutations, which are naturally occurring mutations in C. parapsilosis and C. guilliermondii, which confer elevated MIC levels but a lower level of reduced glucan synthase sensitivity compared with acquired FKS mutations. Some FKS mutants have been shown to have significantly reduced fitness and virulence versus wild type isolates and may contribute to the low incidence of echinocandin resistance reported in large surveillance studies. Treatment strategies evaluated for FKS mutants include echinocandin dose escalation and combination with agents such as calcineurin inhibitors, HSP90 inhibitors, and chitin synthase inhibitors. CONCLUSIONS: While the incidence of echinocandin resistance in Candida spp. is low, it can present a significant therapeutic challenge, especially in multidrug-resistant Candida isolates. Dose escalation is unlikely to be effective in treating FKS mutant isolates, and significant adverse effects limit the clinical use of agents evaluated as combination therapy. Patients with infections failing to respond to echinocandin therapy should undergo susceptibility testing and be treated with an alternative antifungal agent if possible.
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Affiliation(s)
- Nicholas D Beyda
- Nicholas D Beyda PharmD, Infectious Diseases Fellow, Department of Clinical Sciences and Administration, College of Pharmacy, University of Houston, Houston, TX
| | - Russell E Lewis
- Russell E Lewis PharmD, Professor, Department of Clinical Sciences and Administration, College of Pharmacy, University of Houston
| | - Kevin W Garey
- Kevin W Garey PharmD MS, Associate Professor and Chair, Department of Clinical Sciences and Administration, College of Pharmacy, University of Houston
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Lewis RE, Viale P, Kontoyiannis DP. The potential impact of antifungal drug resistance mechanisms on the host immune response to Candida. Virulence 2012; 3:368-76. [PMID: 22722245 PMCID: PMC3478239 DOI: 10.4161/viru.20746] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
A large number of studies have been published over the last two decades examining molecular mechanisms of antifungal resistance in Candida species. However, few of these studies have explored how such mechanisms influence the host immune response to this opportunistic pathogen. With recent advances in our understanding of host immunity to Candida, a body of emerging literature has begun to explore how intrinsic and adaptive resistance mechanisms in Candida alter host immune system evasion and detection, which could have important implications for understanding (1) why certain resistance mechanisms and Candida species predominate in certain patient populations, (2) the biological context for understanding why high in vitro levels of resistance in may not necessarily correlate with risk of drug failure in vivo and (3) insight into effective immunotherapeutic strategies for combatting Candida resistance. Although this area of research is still in its infancy, two themes are emerging: First, the immunoevasion and intracellular persistence of C. glabrata may be a key factor in the capability of this species to persist in the course of multiple antifungal treatments and develop multidrug resistance. Second, changes in the cell wall associated with antifungal resistance often favor evasion for the host immune response.
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Affiliation(s)
- Russell E Lewis
- Division of Infectious Diseases, S. Orsola Malpighi Hospital, University of Bologna, Bologna, Italy.
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Caspofungin Etest susceptibility testing of Candida species: risk of misclassification of susceptible isolates of C. glabrata and C. krusei when adopting the revised CLSI caspofungin breakpoints. Antimicrob Agents Chemother 2012; 56:3965-8. [PMID: 22564836 DOI: 10.1128/aac.00355-12] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The purpose of this study was to evaluate the performance of caspofungin Etest and the recently revised CLSI breakpoints. A total of 497 blood isolates, of which 496 were wild-type isolates, were included. A total of 65/496 susceptible isolates (13.1%) were misclassified as intermediate (I) or resistant (R). Such misclassifications were most commonly observed for Candida krusei (73.1%) and Candida glabrata (33.1%). The revised breakpoints cannot be safely adopted for these two species.
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Differential in vivo activities of anidulafungin, caspofungin, and micafungin against Candida glabrata isolates with and without FKS resistance mutations. Antimicrob Agents Chemother 2012; 56:2435-42. [PMID: 22354305 DOI: 10.1128/aac.06369-11] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
We recently observed that the micafungin MICs for some Candida glabrata fks hot spot mutant isolates are less elevated than those for the other echinocandins, suggesting that the efficacy of micafungin may be differentially dependent on such mutations. Three clinical C. glabrata isolates with or without (S3) fks hot spot mutations R83 (Fks2p-S663F) and RR24 (Fks1p-S629P) and low, medium, and high echinocandin MICs, respectively, were evaluated to assess the in vivo efficacy in an immunocompetent mouse model using three doses of each echinocandin. Drug concentrations were determined in plasma and kidneys by high-performance liquid chromatography (HPLC). A pharmacokinetic-pharmacodynamic mathematical model was used to define the area under the concentration-time curve (AUC) that produced half- and near-maximal activity. Micafungin was equally efficacious against the S3 and R83 isolates. The estimates for the AUCs of each echinocandin that induced half-maximal effect (E(50)s) were 194.2 and 53.99 mg · h/liter, respectively. In contrast, the maximum effect (E(max)) for caspofungin was higher against S3 than R83, but the estimates for E(50) were similar (187.1 and 203.5 mg · h/liter, respectively). Anidulafungin failed to induce a ≥1-log reduction for any of the isolates (AUC range, 139 to 557 mg · h/liter). None of the echinocandins were efficacious in mice challenged with the RR24 isolate despite lower virulence (reduced maximal growth, prolonged lag phase, and lower kidney burden). The AUC associated with half-maximal effect was higher than the average human exposure for all drug-dose-bug combinations except micafungin and the R83 isolate. In conclusion, differences in micafungin MICs are associated with differential antifungal activities in the animal model. This study may have implications for clinical practice and echinocandin breakpoint determination, and further studies are warranted.
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Wiederhold N, Najvar L, Bocanegra R, Kirkpatrick W, Patterson T. Comparison of anidulafungin's and fluconazole's in vivo activity in neutropenic and non-neutropenic models of invasive candidiasis. Clin Microbiol Infect 2012; 18:E20-3. [DOI: 10.1111/j.1469-0691.2011.03712.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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45
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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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Elevated cell wall chitin in Candida albicans confers echinocandin resistance in vivo. Antimicrob Agents Chemother 2011; 56:208-17. [PMID: 21986821 DOI: 10.1128/aac.00683-11] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Candida albicans cells with increased cell wall chitin have reduced echinocandin susceptibility in vitro. The aim of this study was to investigate whether C. albicans cells with elevated chitin levels have reduced echinocandin susceptibility in vivo. BALB/c mice were infected with C. albicans cells with normal chitin levels and compared to mice infected with high-chitin cells. Caspofungin therapy was initiated at 24 h postinfection. Mice infected with chitin-normal cells were successfully treated with caspofungin, as indicated by reduced kidney fungal burdens, reduced weight loss, and decreased C. albicans density in kidney lesions. In contrast, mice infected with high-chitin C. albicans cells were less susceptible to caspofungin, as they had higher kidney fungal burdens and greater weight loss during early infection. Cells recovered from mouse kidneys at 24 h postinfection with high-chitin cells had 1.6-fold higher chitin levels than cells from mice infected with chitin-normal cells and maintained a significantly reduced susceptibility to caspofungin when tested in vitro. At 48 h postinfection, caspofungin treatment induced a further increase in chitin content of C. albicans cells harvested from kidneys compared to saline treatment. Some of the recovered clones had acquired, at a low frequency, a point mutation in FKS1 resulting in a S645Y amino acid substitution, a mutation known to confer echinocandin resistance. This occurred even in cells that had not been exposed to caspofungin. Our results suggest that the efficacy of caspofungin against C. albicans was reduced in vivo due to either elevation of chitin levels in the cell wall or acquisition of FKS1 point mutations.
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