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Stemler J, Többen C, Lass-Flörl C, Steinmann J, Ackermann K, Rath PM, Simon M, Cornely OA, Koehler P. Diagnosis and Treatment of Invasive Aspergillosis Caused by Non- fumigatus Aspergillus spp. J Fungi (Basel) 2023; 9:jof9040500. [PMID: 37108955 PMCID: PMC10141595 DOI: 10.3390/jof9040500] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 03/27/2023] [Accepted: 04/12/2023] [Indexed: 04/29/2023] Open
Abstract
With increasing frequency, clinical and laboratory-based mycologists are consulted on invasive fungal diseases caused by rare fungal species. This review aims to give an overview of the management of invasive aspergillosis (IA) caused by non-fumigatus Aspergillus spp.-namely A. flavus, A. terreus, A. niger and A. nidulans-including diagnostic and therapeutic differences and similarities to A. fumigatus. A. flavus is the second most common Aspergillus spp. isolated in patients with IA and the predominant species in subtropical regions. Treatment is complicated by its intrinsic resistance against amphotericin B (AmB) and high minimum inhibitory concentrations (MIC) for voriconazole. A. nidulans has been frequently isolated in patients with long-term immunosuppression, mostly in patients with primary immunodeficiencies such as chronic granulomatous disease. It has been reported to disseminate more often than other Aspergillus spp. Innate resistance against AmB has been suggested but not yet proven, while MICs seem to be elevated. A. niger is more frequently reported in less severe infections such as otomycosis. Triazoles exhibit varying MICs and are therefore not strictly recommended as first-line treatment for IA caused by A. niger, while patient outcome seems to be more favorable when compared to IA due to other Aspergillus species. A. terreus-related infections have been reported increasingly as the cause of acute and chronic aspergillosis. A recent prospective international multicenter surveillance study showed Spain, Austria, and Israel to be the countries with the highest density of A. terreus species complex isolates collected. This species complex seems to cause dissemination more often and is intrinsically resistant to AmB. Non-fumigatus aspergillosis is difficult to manage due to complex patient histories, varying infection sites and potential intrinsic resistances to antifungals. Future investigational efforts should aim at amplifying the knowledge on specific diagnostic measures and their on-site availability, as well as defining optimal treatment strategies and outcomes of non-fumigatus aspergillosis.
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Affiliation(s)
- Jannik Stemler
- Department I of Internal Medicine, Center for Integrated Oncology Aachen Bonn Cologne Duesseldorf (CIO ABCD), European Diamond Excellence Center for Medical Mycology (ECMM), Faculty of Medicine, University Hospital of Cologne, University of Cologne, 50937 Cologne, Germany
- Institute of Translational Research, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50923 Cologne, Germany
- German Centre for Infection Research (DZIF), Partner Site Bonn-Cologne, 50923 Cologne, Germany
| | - Christina Többen
- Department I of Internal Medicine, Center for Integrated Oncology Aachen Bonn Cologne Duesseldorf (CIO ABCD), European Diamond Excellence Center for Medical Mycology (ECMM), Faculty of Medicine, University Hospital of Cologne, University of Cologne, 50937 Cologne, Germany
- Institute of Translational Research, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50923 Cologne, Germany
- German Centre for Infection Research (DZIF), Partner Site Bonn-Cologne, 50923 Cologne, Germany
| | - Cornelia Lass-Flörl
- Institute of Hygiene and Medical Microbiology, European Diamond Excellence Center for Medical Mycology (ECMM), Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Jörg Steinmann
- Institute of Clinical Hygiene, Medical Microbiology and Infectiology, Paracelsus Medical University, Klinikum Nürnberg, 90419 Nuremberg, Germany
- Institute of Medical Microbiology, University Hospital Essen, European Diamond Excellence Center for Medical Mycology (ECMM), 45147 Essen, Germany
| | - Katharina Ackermann
- Institute of Clinical Hygiene, Medical Microbiology and Infectiology, Paracelsus Medical University, Klinikum Nürnberg, 90419 Nuremberg, Germany
| | - Peter-Michael Rath
- Institute of Medical Microbiology, University Hospital Essen, European Diamond Excellence Center for Medical Mycology (ECMM), 45147 Essen, Germany
| | - Michaela Simon
- Institute for Medical Microbiology, Immunology and Hygiene, Faculty of Medicine, University Hospital of Cologne, University of Cologne, 50937 Cologne, Germany
| | - Oliver Andreas Cornely
- Department I of Internal Medicine, Center for Integrated Oncology Aachen Bonn Cologne Duesseldorf (CIO ABCD), European Diamond Excellence Center for Medical Mycology (ECMM), Faculty of Medicine, University Hospital of Cologne, University of Cologne, 50937 Cologne, Germany
- Institute of Translational Research, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50923 Cologne, Germany
- German Centre for Infection Research (DZIF), Partner Site Bonn-Cologne, 50923 Cologne, Germany
- Clinical Trials Centre Cologne (ZKS Köln), University of Cologne, 50935 Cologne, Germany
| | - Philipp Koehler
- Department I of Internal Medicine, Center for Integrated Oncology Aachen Bonn Cologne Duesseldorf (CIO ABCD), European Diamond Excellence Center for Medical Mycology (ECMM), Faculty of Medicine, University Hospital of Cologne, University of Cologne, 50937 Cologne, Germany
- Institute of Translational Research, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50923 Cologne, Germany
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Genetic Diversity of Human Fungal Pathogens. CURRENT CLINICAL MICROBIOLOGY REPORTS 2023. [DOI: 10.1007/s40588-023-00188-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
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Fakhim H, Badali H, Dannaoui E, Nasirian M, Jahangiri F, Raei M, Vaseghi N, Ahmadikia K, Vaezi A. Trends in the Prevalence of Amphotericin B-Resistance (AmBR) among Clinical Isolates of Aspergillus Species. J Mycol Med 2022; 32:101310. [PMID: 35907396 DOI: 10.1016/j.mycmed.2022.101310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 07/11/2022] [Accepted: 07/12/2022] [Indexed: 11/29/2022]
Abstract
The challenges of the invasive infections caused by the resistant Aspergillus species include the limited access to antifungals for treatment and high mortality. This study aimed to provide a global perspective of the prevalence of amphotericin B resistance (AmBR), geographic distribution, and the trend of AmBR from 2010 to 2020. To analyze the prevalence of in vitro AmBR in clinical Aspergillus species, we reviewed the literature and identified a total of 72 articles. AmBR was observed in 1128 out of 3061 Aspergillus terreus (36.8%), 538 out of 3663 Aspergillus flavus (14.9%), 141 out of 2691 Aspergillus niger (5.2%), and 353 out of 17,494 Aspergillus fumigatus isolates (2.01%). An increasing trend in AmB-resistant isolates of A. fumigatus and a decreasing trend in AmB-resistant A. terreus and A. flavus isolates were observed between 2016 and 2020. AmB-resistant A. terreus and A. niger isolates, accounting for 40.4% and 20.9%, respectively, were the common AmB-resistant Aspergillus species in Asian studies. However, common AmB-resistant Aspergillus species reported by European and American studies were A. terreus and A. flavus isolates, accounting for 40.1% and 14.3% in 31 studies from Europe and 25.1% and 11.7% in 14 studies from America, respectively. The prevalence of AmB-resistant A. niger in Asian isolates was higher than in American and European. We found a low prevalence of A. terreus in American isolates (25.1%) compared to Asian (40.4%) and European (40.1%). Future studies should focus on analyzing the trend of AmBR on a regional basis and using the same methodologies.
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Affiliation(s)
- Hamed Fakhim
- Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Hamid Badali
- Department of Molecular Microbiology & Immunology/South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, Texas, USA
| | - Eric Dannaoui
- Université de Paris, Faculté de Médecine, APHP, Hôpital Européen Georges Pompidou, Unité de Parasitologie-Mycologie, Service de Microbiologie, Paris, France
| | - Maryam Nasirian
- Infectious Diseases and Tropical Medicine Research Center; and Epidemiology and Biostatistics Department, Health School, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Fateme Jahangiri
- Department of Medical Laboratory Science, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Maedeh Raei
- Faculty of medicine, Sari branch, Islamic Azad University, Sari, Iran
| | - Narges Vaseghi
- Department of Pathobiology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Kazem Ahmadikia
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Afsane Vaezi
- Department of Medical Laboratory Science, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran.
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Ferreira ES, Cordeiro LV, Silva DDEF, Souza HDS, Athayde-Filho PFDE, Barbosa-Filho JM, Scotti L, Lima EO, Castro RDDE. Antifungal activity and mechanism of action of 2-chloro-N -phenylacetamide: a new molecule with activity against strains of Aspergillus flavus. AN ACAD BRAS CIENC 2021; 93:e20200997. [PMID: 34550200 DOI: 10.1590/0001-3765202120200997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 02/01/2021] [Indexed: 11/21/2022] Open
Abstract
Aspergillus genus causes many diseases, and the species Aspergillus flavus is highly virulent. Treatment of aspergillosis involves azole derivatives such as voriconazole and polyenes such as amphotericin B. Due to an increase in fungal resistance, treatments are now less effective; the search for new compounds with promising antifungal activity has gained importance. The aims of this study were to evaluate the effects of the synthetic amide 2-chloro-N-phenylacetamide (A1Cl) against strains of Aspergillus flavus and to elucidate its mechanism of action. Thus, the minimum inhibitory concentration, minimum fungicidal concentration, conidial germination, associations with antifungal agents, cell wall activities, membrane activities and molecular docking were evaluated. A1Cl presented antifungal activity against Aspergillus flavus strains with a minimum inhibitory concentration of between 16 and 256 μg/mL and a minimum fungicidal concentration between 32 and 512 μg/mL. The minimum inhibitory concentration of A1Cl also inhibited conidial germination, but when associated with amphotericin B and voriconazole, it promoted antagonistic effects. Binding to ergosterol on the fungal plasma membrane is the likely mechanism of action, along with possible inhibition of DNA synthesis through the inhibition of thymidylate synthase. It is concluded that the amide 2-chloro-N-phenylacetamide has promising antifungal potential.
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Affiliation(s)
- Elba S Ferreira
- Universidade Federal da Paraíba, Departamento de Cências Farmacêuticas, Campus I, Loteamento Cidade Universitária, s/n, Castelo Branco, 58051-970 João Pessoa, PB, Brazil
| | - Laísa V Cordeiro
- Universidade Federal da Paraíba, Departamento de Cências Farmacêuticas, Campus I, Loteamento Cidade Universitária, s/n, Castelo Branco, 58051-970 João Pessoa, PB, Brazil
| | - Daniele DE F Silva
- Universidade Federal da Paraíba, Departamento de Cências Farmacêuticas, Campus I, Loteamento Cidade Universitária, s/n, Castelo Branco, 58051-970 João Pessoa, PB, Brazil
| | - Helivaldo D S Souza
- Universidade Federal da Paraíba, Departamento de Química, Campus I, Loteamento Cidade Universitária, s/n, Castelo Branco, 58051-970 João Pessoa, PB, Brazil
| | - Petrônio F DE Athayde-Filho
- Universidade Federal da Paraíba, Departamento de Química, Campus I, Loteamento Cidade Universitária, s/n, Castelo Branco, 58051-970 João Pessoa, PB, Brazil
| | - José Maria Barbosa-Filho
- Universidade Federal da Paraíba, Departamento de Cências Farmacêuticas, Campus I, Loteamento Cidade Universitária, s/n, Castelo Branco, 58051-970 João Pessoa, PB, Brazil
| | - Luciana Scotti
- Universidade Federal da Paraíba, Departamento de Cências Farmacêuticas, Campus I, Loteamento Cidade Universitária, s/n, Castelo Branco, 58051-970 João Pessoa, PB, Brazil
| | - Edeltrudes O Lima
- Universidade Federal da Paraíba, Departamento de Cências Farmacêuticas, Campus I, Loteamento Cidade Universitária, s/n, Castelo Branco, 58051-970 João Pessoa, PB, Brazil
| | - Ricardo D DE Castro
- Universidade Federal da Paraíba, Departamento de Cências Farmacêuticas, Campus I, Loteamento Cidade Universitária, s/n, Castelo Branco, 58051-970 João Pessoa, PB, Brazil
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Arastehfar A, Carvalho A, Houbraken J, Lombardi L, Garcia-Rubio R, Jenks J, Rivero-Menendez O, Aljohani R, Jacobsen I, Berman J, Osherov N, Hedayati M, Ilkit M, Armstrong-James D, Gabaldón T, Meletiadis J, Kostrzewa M, Pan W, Lass-Flörl C, Perlin D, Hoenigl M. Aspergillus fumigatus and aspergillosis: From basics to clinics. Stud Mycol 2021; 100:100115. [PMID: 34035866 PMCID: PMC8131930 DOI: 10.1016/j.simyco.2021.100115] [Citation(s) in RCA: 87] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The airborne fungus Aspergillus fumigatus poses a serious health threat to humans by causing numerous invasive infections and a notable mortality in humans, especially in immunocompromised patients. Mould-active azoles are the frontline therapeutics employed to treat aspergillosis. The global emergence of azole-resistant A. fumigatus isolates in clinic and environment, however, notoriously limits the therapeutic options of mould-active antifungals and potentially can be attributed to a mortality rate reaching up to 100 %. Although specific mutations in CYP 51A are the main cause of azole resistance, there is a new wave of azole-resistant isolates with wild-type CYP 51A genotype challenging the efficacy of the current diagnostic tools. Therefore, applications of whole-genome sequencing are increasingly gaining popularity to overcome such challenges. Prominent echinocandin tolerance, as well as liver and kidney toxicity posed by amphotericin B, necessitate a continuous quest for novel antifungal drugs to combat emerging azole-resistant A. fumigatus isolates. Animal models and the tools used for genetic engineering require further refinement to facilitate a better understanding about the resistance mechanisms, virulence, and immune reactions orchestrated against A. fumigatus. This review paper comprehensively discusses the current clinical challenges caused by A. fumigatus and provides insights on how to address them.
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Affiliation(s)
- A. Arastehfar
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - A. Carvalho
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Guimarães/Braga, Portugal
| | - J. Houbraken
- Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands
| | - L. Lombardi
- UCD Conway Institute and School of Medicine, University College Dublin, Dublin 4, Ireland
| | - R. Garcia-Rubio
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - J.D. Jenks
- Department of Medicine, University of California San Diego, San Diego, CA, 92103, USA
- Clinical and Translational Fungal-Working Group, University of California San Diego, La Jolla, CA, 92093, USA
| | - O. Rivero-Menendez
- Medical Mycology Reference Laboratory, National Center for Microbiology, Instituto de Salud Carlos III, Madrid, 28222, Spain
| | - R. Aljohani
- Department of Infectious Diseases, Imperial College London, London, UK
| | - I.D. Jacobsen
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology—Hans Knöll Institute, Jena, Germany
- Institute for Microbiology, Friedrich Schiller University, Jena, Germany
| | - J. Berman
- Research Group Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology—Hans Knöll Institute, Jena, Germany
| | - N. Osherov
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, 69978, Israel
| | - M.T. Hedayati
- Invasive Fungi Research Center/Department of Medical Mycology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - M. Ilkit
- Division of Mycology, Department of Microbiology, Faculty of Medicine, Çukurova University, 01330, Adana, Turkey
| | | | - T. Gabaldón
- Life Sciences Programme, Supercomputing Center (BSC-CNS), Jordi Girona, Barcelona, 08034, Spain
- Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB), Barcelona, Spain
- ICREA, Pg. Lluís Companys 23, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluís Companys 23, 08010, Barcelona, Spain
| | - J. Meletiadis
- Clinical Microbiology Laboratory, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | | | - W. Pan
- Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - C. Lass-Flörl
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - D.S. Perlin
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - M. Hoenigl
- Department of Medicine, University of California San Diego, San Diego, CA, 92103, USA
- Section of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Medical University of Graz, 8036, Graz, Austria
- Division of Infectious Diseases and Global Public Health, Department of Medicine, University of California San Diego, San Diego, CA 92093, USA
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Carvalho ÂR, Genz Bazana LC, Ferrão MF, Fuentefria AM. Curve fitting and linearization of UV-Vis spectrophotometric measurements to estimate yeast in inoculum preparation. Anal Biochem 2021; 625:114216. [PMID: 33933444 DOI: 10.1016/j.ab.2021.114216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 03/24/2021] [Accepted: 04/16/2021] [Indexed: 11/29/2022]
Abstract
The counting of microorganisms is essential in the area of microbiology, especially in the preparation of inoculum. The main methods for obtaining inoculum are McFarland standard, Neubauer chamber, and plate count. However, the visual comparison is subjective while the counting in the chamber and the plating are technically time-consuming. For this reason, our article aims to correlate the absorbance of the spectrophotometer in the visible ultraviolet region (UV-Vis) with the cell counting in the Neubauer chamber. This study used suspensions of Candida spp. measured at three wavelengths (530, 600, and 700 nm) and counting in a Neubauer chamber. In the next step, curves were adjusted with different polynomials using absorbances and counts. The two best polynomial curve fittings were the Saturation Growth Rate (SGR) and Morgan-Mercer-Flodin (MMF). Therefore, the polynomials were linearized and a direct correlation between absorbance and the number of cells was made. The proposed method proved to be more accurate (5 ± 0.5 × 106) than the comparison with the McFarland turbidity (1-5 x 106) and more practical than plate counting. Predicting the number of cells by UV-Vis is an alternative that reduces the uncertainty of the cell count interval for inoculum preparation.
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Affiliation(s)
- Ânderson Ramos Carvalho
- Laboratório de Pesquisa em Micologia Aplicada, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
| | - Luana Candice Genz Bazana
- Laboratório de Pesquisa em Micologia Aplicada, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Marco Flôres Ferrão
- Programa de Pós-Graduação em Química, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, 91501-970, Brazil
| | - Alexandre Meneghello Fuentefria
- Laboratório de Pesquisa em Micologia Aplicada, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
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Rao MK, Alam MS, Gopalakrishnan R, Mukherjee B. Fungal abscess after intra-orbital steroid injection: a case report. Orbit 2021; 41:611-615. [PMID: 33771079 DOI: 10.1080/01676830.2021.1903043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
A 28-year-old male presented with gradually progressive swelling of the right lower eyelid along with a prominence of the eye for 6 months. He had received oral steroids and intraorbital triamcinolone acetonide injection in the inferior quadrant for active thyroid eye disease. External examination revealed right eye proptosis and swelling along the inferior orbital region. Magnetic resonance imaging showed an ill-defined soft tissue lesion in the inferior extraconal space and a bulky right inferior rectus. Histopathology of the biopsied material revealed inflammation with septate fungal filaments, identified as Aspergillus flavus on culture. He responded well to oral voriconazole despite a recurrence during the course of treatment. Intraorbital steroids are given for idiopathic and thyroid-associated orbital inflammation. This is a report of a rare complication of fungal orbital abscess following intraorbital corticosteroid injection in an immunocompetent young patient.
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Affiliation(s)
- Mythri K Rao
- Orbit, Oculoplasty, Reconstructive and Aesthetic Services, Medical Research Foundation, Sankara Nethralaya, Chennai, India
| | - Md Shahid Alam
- Orbit, Oculoplasty, Reconstructive and Aesthetic Services, Aditya Birla Sankara Nethralaya, Kolkata (A Unit of Medical Research Foundation, Chennai), India
| | | | - Bipasha Mukherjee
- Orbit, Oculoplasty, Reconstructive and Aesthetic Services, Medical Research Foundation, Sankara Nethralaya, Chennai, India
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Moslem M, Mahmoudabadi AZ. The high efficacy of luliconazole against environmental and otomycosis Aspergillus flavus strains. IRANIAN JOURNAL OF MICROBIOLOGY 2020; 12:170-176. [PMID: 32494352 PMCID: PMC7244823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
BACKGROUND AND OBJECTIVES Luliconazole is currently confirmed for the topical therapy of dermatophytosis. Moreover, it is found that luliconazole has in vitro activity against some molds and yeast species. The aim of the present study was to evaluate the efficacy of luliconazole in comparison to routine used antifungals on clinical and environmental isolates of Aspergillus flavus. MATERIALS AND METHODS Thirty eight isolates of A. flavus (18 environmental and 20 clinical isolates) were detected based on morphological and microscopic features and also PCR-sequencing of β-tubulin ribosomal DNA gene. All the isolates were tested against luliconazole, voriconazole, amphotericin B and caspofungin. Minimum inhibitory concentration (MIC), MIC50, MIC90 and MIC Geometric (GM) were calculated using CLSI M38-A2 protocol for both environmental and clinical isolates. RESULTS Luliconazole with extremely low MIC range, 0.00049-0.00781 μg/mL and MICGM 0.00288 μg/mL showed very strong activity against both clinical and environmental A. flavus isolates. Moreover, voriconazole inhibited 100% of isolates at defined epidemiological cutoff values (ECV ≤ 2 μg/ml). 50% and 27.8% of clinical and environmental isolates of A. flavus, were resistant to caspofungin, respectively. Whereas, all the isolates were found to be resistant to amphotericin B. CONCLUSION The analysis of our data clearly indicated that luliconazole (with MICGM 0.00244 μg/ml for clinical and 0.00336 μg/ml for environmental isolates) had the highest in vitro activity against A. flavus strains.
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Affiliation(s)
- Maryam Moslem
- 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
| | - Ali Zarei 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,Corresponding author: Ali Zarei Mahmoudabadi, PhD, Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran AND Department of Medical Mycology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. Tel: +986133330074, Fax: +986133332036,
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rmtA-Dependent Transcriptome and Its Role in Secondary Metabolism, Environmental Stress, and Virulence in Aspergillus flavus. G3-GENES GENOMES GENETICS 2019; 9:4087-4096. [PMID: 31601618 PMCID: PMC6893206 DOI: 10.1534/g3.119.400777] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Aspergillus flavus colonizes numerous oil seed crops such as maize, peanuts, treenuts and cottonseed worldwide, contaminating them with aflatoxins and other harmful toxins. Previously our lab characterized the gene rmtA, which encodes an arginine methyltransferase in A. flavus, and demonstrated its role governing the expression of regulators in the aflatoxin gene cluster and subsequent synthesis of toxin. Furthermore, our studies revealed that rmtA also controls conidial and sclerotial development implicating it as an epigenetic regulator in A. flavus. To confirm this, we performed a RNA sequencing analysis to ascertain the extent of rmtA’s influence on the transcriptome of A. flavus. In this analysis we identified over 2000 genes that were rmtA-dependent, including over 200 transcription factor genes, as well as an uncharacterized secondary metabolite gene cluster possibly responsible for the synthesis of an epidithiodiketopiperazine-like compound. Our results also revealed rmtA-dependent genes involved in multiple types of abiotic stress response in A. flavus. Importantly, hundreds of genes active during maize infection were also regulated by rmtA. In addition, in the animal infection model, rmtA was dispensable for virulence, however forced overexpression of rmtA increased mortality with respect to the wild type.
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Rudramurthy SM, Paul RA, Chakrabarti A, Mouton JW, Meis JF. Invasive Aspergillosis by Aspergillus flavus: Epidemiology, Diagnosis, Antifungal Resistance, and Management. J Fungi (Basel) 2019; 5:jof5030055. [PMID: 31266196 PMCID: PMC6787648 DOI: 10.3390/jof5030055] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/28/2019] [Accepted: 06/29/2019] [Indexed: 12/12/2022] Open
Abstract
Aspergillus flavus is the second most common etiological agent of invasive aspergillosis (IA) after A. fumigatus. However, most literature describes IA in relation to A. fumigatus or together with other Aspergillus species. Certain differences exist in IA caused by A. flavus and A. fumigatus and studies on A. flavus infections are increasing. Hence, we performed a comprehensive updated review on IA due to A. flavus. A. flavus is the cause of a broad spectrum of human diseases predominantly in Asia, the Middle East, and Africa possibly due to its ability to survive better in hot and arid climatic conditions compared to other Aspergillus spp. Worldwide, ~10% of cases of bronchopulmonary aspergillosis are caused by A. flavus. Outbreaks have usually been associated with construction activities as invasive pulmonary aspergillosis in immunocompromised patients and cutaneous, subcutaneous, and mucosal forms in immunocompetent individuals. Multilocus microsatellite typing is well standardized to differentiate A. flavus isolates into different clades. A. flavus is intrinsically resistant to polyenes. In contrast to A. fumigatus, triazole resistance infrequently occurs in A. flavus and is associated with mutations in the cyp51C gene. Overexpression of efflux pumps in non-wildtype strains lacking mutations in the cyp51 gene can also lead to high voriconazole minimum inhibitory concentrations. Voriconazole remains the drug of choice for treatment, and amphotericin B should be avoided. Primary therapy with echinocandins is not the first choice but the combination with voriconazole or as monotherapy may be used when the azoles and amphotericin B are contraindicated.
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Affiliation(s)
- Shivaprakash M Rudramurthy
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Research, Chandigarh 160012, India.
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC, 3015GD Rotterdam, The Netherlands.
| | - Raees A Paul
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Research, Chandigarh 160012, India
| | - Arunaloke Chakrabarti
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Research, Chandigarh 160012, India
| | - Johan W Mouton
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC, 3015GD Rotterdam, The Netherlands
| | - Jacques F Meis
- Department of Medical Microbiology and Infectious Diseases, Canisius Wilhelmina Hospital (CWZ) and Center of Expertise, 6532SZ Nijmegen, The Netherlands
- Center of Expertise in Mycology Radboudumc/CWZ, 6532SZ Nijmegen, The Netherlands
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11
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The Aspergillus flavus rtfA Gene Regulates Plant and Animal Pathogenesis and Secondary Metabolism. Appl Environ Microbiol 2019; 85:AEM.02446-18. [PMID: 30635379 DOI: 10.1128/aem.02446-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 12/31/2018] [Indexed: 02/04/2023] Open
Abstract
Aspergillus flavus is an opportunistic fungal plant and human pathogen and a producer of mycotoxins, including aflatoxin B1 (AFB1). As part of our ongoing studies to elucidate the biological functions of the A. flavus rtfA gene, we examined its role in the pathogenicity of both plant and animal model systems. rtfA encodes a putative RNA polymerase II (Pol II) transcription elongation factor previously characterized in Saccharomyces cerevisiae, Aspergillus nidulans, and Aspergillus fumigatus, where it was shown to regulate several important cellular processes, including morphogenesis and secondary metabolism. In addition, an initial study in A. flavus indicated that rtfA also influences development and production of AFB1; however, its effect on virulence is unknown. The current study reveals that the rtfA gene is indispensable for normal pathogenicity in plants when using peanut seed as an infection model, as well as in animals, as shown in the Galleria mellonella infection model. Interestingly, rtfA positively regulates several processes known to be necessary for successful fungal invasion and colonization of host tissue, such as adhesion to surfaces, protease and lipase activity, cell wall composition and integrity, and tolerance to oxidative stress. In addition, metabolomic analysis revealed that A. flavus rtfA affects the production of several secondary metabolites, including AFB1, aflatrem, leporins, aspirochlorine, ditryptophenaline, and aflavinines, supporting a role of rtfA as a global regulator of secondary metabolism. Heterologous complementation of an A. flavus rtfA deletion strain with rtfA homologs from A. nidulans or S. cerevisiae fully rescued the wild-type phenotype, indicating that these rtfA homologs are functionally conserved among these three species.IMPORTANCE In this study, the epigenetic global regulator rtfA, which encodes a putative RNA-Pol II transcription elongation factor-like protein, was characterized in the mycotoxigenic and opportunistic pathogen A. flavus Specifically, its involvement in A. flavus pathogenesis in plant and animal models was studied. Here, we show that rtfA positively regulates A. flavus virulence in both models. Furthermore, rtfA-dependent effects on factors necessary for successful invasion and colonization of host tissue by A. flavus were also assessed. Our study indicates that rtfA plays a role in A. flavus adherence to surfaces, hydrolytic activity, normal cell wall formation, and response to oxidative stress. This study also revealed a profound effect of rtfA on the metabolome of A. flavus, including the production of potent mycotoxins.
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12
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Ullmann AJ, Aguado JM, Arikan-Akdagli S, Denning DW, Groll AH, Lagrou K, Lass-Flörl C, Lewis RE, Munoz P, Verweij PE, Warris A, Ader F, Akova M, Arendrup MC, Barnes RA, Beigelman-Aubry C, Blot S, Bouza E, Brüggemann RJM, Buchheidt D, Cadranel J, Castagnola E, Chakrabarti A, Cuenca-Estrella M, Dimopoulos G, Fortun J, Gangneux JP, Garbino J, Heinz WJ, Herbrecht R, Heussel CP, Kibbler CC, Klimko N, Kullberg BJ, Lange C, Lehrnbecher T, Löffler J, Lortholary O, Maertens J, Marchetti O, Meis JF, Pagano L, Ribaud P, Richardson M, Roilides E, Ruhnke M, Sanguinetti M, Sheppard DC, Sinkó J, Skiada A, Vehreschild MJGT, Viscoli C, Cornely OA. Diagnosis and management of Aspergillus diseases: executive summary of the 2017 ESCMID-ECMM-ERS guideline. Clin Microbiol Infect 2018; 24 Suppl 1:e1-e38. [PMID: 29544767 DOI: 10.1016/j.cmi.2018.01.002] [Citation(s) in RCA: 800] [Impact Index Per Article: 133.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 01/02/2018] [Accepted: 01/03/2018] [Indexed: 02/06/2023]
Abstract
The European Society for Clinical Microbiology and Infectious Diseases, the European Confederation of Medical Mycology and the European Respiratory Society Joint Clinical Guidelines focus on diagnosis and management of aspergillosis. Of the numerous recommendations, a few are summarized here. Chest computed tomography as well as bronchoscopy with bronchoalveolar lavage (BAL) in patients with suspicion of pulmonary invasive aspergillosis (IA) are strongly recommended. For diagnosis, direct microscopy, preferably using optical brighteners, histopathology and culture are strongly recommended. Serum and BAL galactomannan measures are recommended as markers for the diagnosis of IA. PCR should be considered in conjunction with other diagnostic tests. Pathogen identification to species complex level is strongly recommended for all clinically relevant Aspergillus isolates; antifungal susceptibility testing should be performed in patients with invasive disease in regions with resistance found in contemporary surveillance programmes. Isavuconazole and voriconazole are the preferred agents for first-line treatment of pulmonary IA, whereas liposomal amphotericin B is moderately supported. Combinations of antifungals as primary treatment options are not recommended. Therapeutic drug monitoring is strongly recommended for patients receiving posaconazole suspension or any form of voriconazole for IA treatment, and in refractory disease, where a personalized approach considering reversal of predisposing factors, switching drug class and surgical intervention is also strongly recommended. Primary prophylaxis with posaconazole is strongly recommended in patients with acute myelogenous leukaemia or myelodysplastic syndrome receiving induction chemotherapy. Secondary prophylaxis is strongly recommended in high-risk patients. We strongly recommend treatment duration based on clinical improvement, degree of immunosuppression and response on imaging.
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Affiliation(s)
- A J Ullmann
- Department of Infectious Diseases, Haematology and Oncology, University Hospital Würzburg, Würzburg, Germany; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - J M Aguado
- Infectious Diseases Unit, University Hospital Madrid, Madrid, Spain; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - S Arikan-Akdagli
- Department of Medical Microbiology, Hacettepe University Medical School, Ankara, Turkey; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - D W Denning
- The National Aspergillosis Centre, Wythenshawe Hospital, Mycology Reference Centre Manchester, Manchester University NHS Foundation Trust, ECMM Excellence Centre of Medical Mycology, Manchester, UK; The University of Manchester, Manchester, UK; Manchester Academic Health Science Centre, Manchester, UK; European Confederation of Medical Mycology (ECMM)
| | - A H Groll
- Department of Paediatric Haematology/Oncology, Centre for Bone Marrow Transplantation, University Children's Hospital Münster, Münster, Germany; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - K Lagrou
- Department of Microbiology and Immunology, ECMM Excellence Centre of Medical Mycology, University Hospital Leuven, Leuven, Belgium; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - C Lass-Flörl
- Institute of Hygiene, Microbiology and Social Medicine, ECMM Excellence Centre of Medical Mycology, Medical University Innsbruck, Innsbruck, Austria; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - R E Lewis
- Infectious Diseases Clinic, Sant'Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy; ESCMID Fungal Infection Study Group (EFISG)
| | - P Munoz
- Department of Medical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain; CIBER Enfermedades Respiratorias - CIBERES (CB06/06/0058), Madrid, Spain; Medicine Department, School of Medicine, Universidad Complutense de Madrid, Madrid, Spain; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - P E Verweij
- Department of Medical Microbiology, Radboud University Medical Centre, Centre of Expertise in Mycology Radboudumc/CWZ, ECMM Excellence Centre of Medical Mycology, Nijmegen, Netherlands; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - A Warris
- MRC Centre for Medical Mycology, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - F Ader
- Department of Infectious Diseases, Hospices Civils de Lyon, Lyon, France; Inserm 1111, French International Centre for Infectious Diseases Research (CIRI), Université Claude Bernard Lyon 1, Lyon, France; European Respiratory Society (ERS)
| | - M Akova
- Department of Medicine, Section of Infectious Diseases, Hacettepe University Medical School, Ankara, Turkey; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - M C Arendrup
- Department Microbiological Surveillance and Research, Statens Serum Institute, Copenhagen, Denmark; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - R A Barnes
- Department of Medical Microbiology and Infectious Diseases, Institute of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, UK; European Confederation of Medical Mycology (ECMM)
| | - C Beigelman-Aubry
- Department of Diagnostic and Interventional Radiology, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland; European Respiratory Society (ERS)
| | - S Blot
- Department of Internal Medicine, Ghent University, Ghent, Belgium; Burns, Trauma and Critical Care Research Centre, University of Queensland, Brisbane, Australia; European Respiratory Society (ERS)
| | - E Bouza
- Department of Medical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain; CIBER Enfermedades Respiratorias - CIBERES (CB06/06/0058), Madrid, Spain; Medicine Department, School of Medicine, Universidad Complutense de Madrid, Madrid, Spain; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - R J M Brüggemann
- Radboud Centre for Infectious Diseases, Radboud University Medical Centre, Centre of Expertise in Mycology Radboudumc/CWZ, ECMM Excellence Centre of Medical Mycology, Nijmegen, Netherlands; ESCMID Fungal Infection Study Group (EFISG)
| | - D Buchheidt
- Medical Clinic III, University Hospital Mannheim, Mannheim, Germany; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - J Cadranel
- Department of Pneumology, University Hospital of Tenon and Sorbonne, University of Paris, Paris, France; European Respiratory Society (ERS)
| | - E Castagnola
- Infectious Diseases Unit, Istituto Giannina Gaslini Children's Hospital, Genoa, Italy; ESCMID Fungal Infection Study Group (EFISG)
| | - A Chakrabarti
- Department of Medical Microbiology, Postgraduate Institute of Medical Education & Research, Chandigarh, India; European Confederation of Medical Mycology (ECMM)
| | - M Cuenca-Estrella
- Instituto de Salud Carlos III, Madrid, Spain; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - G Dimopoulos
- Department of Critical Care Medicine, Attikon University Hospital, National and Kapodistrian University of Athens, Medical School, Athens, Greece; European Respiratory Society (ERS)
| | - J Fortun
- Infectious Diseases Service, Ramón y Cajal Hospital, Madrid, Spain; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - J-P Gangneux
- Univ Rennes, CHU Rennes, Inserm, Irset (Institut de Recherche en santé, environnement et travail) - UMR_S 1085, Rennes, France; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - J Garbino
- Division of Infectious Diseases, University Hospital of Geneva, Geneva, Switzerland; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - W J Heinz
- Department of Infectious Diseases, Haematology and Oncology, University Hospital Würzburg, Würzburg, Germany; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - R Herbrecht
- Department of Haematology and Oncology, University Hospital of Strasbourg, Strasbourg, France; ESCMID Fungal Infection Study Group (EFISG)
| | - C P Heussel
- Diagnostic and Interventional Radiology, Thoracic Clinic, University Hospital Heidelberg, Heidelberg, Germany; European Confederation of Medical Mycology (ECMM)
| | - C C Kibbler
- Centre for Medical Microbiology, University College London, London, UK; European Confederation of Medical Mycology (ECMM)
| | - N Klimko
- Department of Clinical Mycology, Allergy and Immunology, North Western State Medical University, St Petersburg, Russia; European Confederation of Medical Mycology (ECMM)
| | - B J Kullberg
- Radboud Centre for Infectious Diseases, Radboud University Medical Centre, Centre of Expertise in Mycology Radboudumc/CWZ, ECMM Excellence Centre of Medical Mycology, Nijmegen, Netherlands; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - C Lange
- International Health and Infectious Diseases, University of Lübeck, Lübeck, Germany; Clinical Infectious Diseases, Research Centre Borstel, Leibniz Center for Medicine & Biosciences, Borstel, Germany; German Centre for Infection Research (DZIF), Tuberculosis Unit, Hamburg-Lübeck-Borstel-Riems Site, Lübeck, Germany; European Respiratory Society (ERS)
| | - T Lehrnbecher
- Division of Paediatric Haematology and Oncology, Hospital for Children and Adolescents, Johann Wolfgang Goethe-University, Frankfurt, Germany; European Confederation of Medical Mycology (ECMM)
| | - J Löffler
- Department of Infectious Diseases, Haematology and Oncology, University Hospital Würzburg, Würzburg, Germany; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - O Lortholary
- Department of Infectious and Tropical Diseases, Children's Hospital, University of Paris, Paris, France; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - J Maertens
- Department of Haematology, ECMM Excellence Centre of Medical Mycology, University Hospital Leuven, Leuven, Belgium; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - O Marchetti
- Infectious Diseases Service, Department of Medicine, Lausanne University Hospital, Lausanne, Switzerland; Department of Medicine, Ensemble Hospitalier de la Côte, Morges, Switzerland; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - J F Meis
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Centre of Expertise in Mycology Radboudumc/CWZ, ECMM Excellence Centre of Medical Mycology, Nijmegen, Netherlands; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - L Pagano
- Department of Haematology, Universita Cattolica del Sacro Cuore, Roma, Italy; European Confederation of Medical Mycology (ECMM)
| | - P Ribaud
- Quality Unit, Pôle Prébloc, Saint-Louis and Lariboisière Hospital Group, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - M Richardson
- The National Aspergillosis Centre, Wythenshawe Hospital, Mycology Reference Centre Manchester, Manchester University NHS Foundation Trust, ECMM Excellence Centre of Medical Mycology, Manchester, UK; The University of Manchester, Manchester, UK; Manchester Academic Health Science Centre, Manchester, UK; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - E Roilides
- Infectious Diseases Unit, 3rd Department of Paediatrics, Faculty of Medicine, Aristotle University School of Health Sciences, Thessaloniki, Greece; Hippokration General Hospital, Thessaloniki, Greece; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - M Ruhnke
- Department of Haematology and Oncology, Paracelsus Hospital, Osnabrück, Germany; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - M Sanguinetti
- Institute of Microbiology, Fondazione Policlinico Universitario A. Gemelli - Università Cattolica del Sacro Cuore, Rome, Italy; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - D C Sheppard
- Division of Infectious Diseases, Department of Medicine, Microbiology and Immunology, McGill University, Montreal, Canada; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - J Sinkó
- Department of Haematology and Stem Cell Transplantation, Szent István and Szent László Hospital, Budapest, Hungary; ESCMID Fungal Infection Study Group (EFISG)
| | - A Skiada
- First Department of Medicine, Laiko Hospital, National and Kapodistrian University of Athens, Athens, Greece; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - M J G T Vehreschild
- Department I of Internal Medicine, ECMM Excellence Centre of Medical Mycology, University Hospital of Cologne, Cologne, Germany; Centre for Integrated Oncology, Cologne-Bonn, University of Cologne, Cologne, Germany; German Centre for Infection Research (DZIF) partner site Bonn-Cologne, Cologne, Germany; European Confederation of Medical Mycology (ECMM)
| | - C Viscoli
- Ospedale Policlinico San Martino and University of Genova (DISSAL), Genova, Italy; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM)
| | - O A Cornely
- First Department of Medicine, Laiko Hospital, National and Kapodistrian University of Athens, Athens, Greece; German Centre for Infection Research (DZIF) partner site Bonn-Cologne, Cologne, Germany; CECAD Cluster of Excellence, University of Cologne, Cologne, Germany; Clinical Trials Center Cologne, University Hospital of Cologne, Cologne, Germany; ESCMID Fungal Infection Study Group (EFISG); European Confederation of Medical Mycology (ECMM); ESCMID European Study Group for Infections in Compromised Hosts (ESGICH).
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13
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Desoubeaux G, Cray C. Animal Models of Aspergillosis. Comp Med 2018; 68:109-123. [PMID: 29663936 PMCID: PMC5897967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 03/29/2017] [Accepted: 07/09/2017] [Indexed: 06/08/2023]
Abstract
Aspergillosis is an airborne fungal disease caused by Aspergillus spp., a group of ubiquitous molds. This disease causes high morbidity and mortality in both humans and animals. The growing importance of this infection over recent decades has created a need for practical and reproducible models of aspergillosis. The use of laboratory animals provides a platform to understand fungal virulence and pathophysiology, assess diagnostic tools, and evaluate new antifungal drugs. In this review, we describe the fungus, various Aspergillus-related diseases in humans and animals and various experimental animal models. Overall, we highlight the advantages and limitations of the animal models, the experimental variables that can affect the course of the disease and the reproducibility of infection, and the critical need for standardization of the species, immunosuppressive drugs, route of infection, and diagnostic criteria to use.
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Affiliation(s)
- Guillaume Desoubeaux
- Department of Pathology and Laboratory Medicine, Division of Comparative Pathology, Miller School of Medicine, University of Miami, Miami, Florida, USA; Parasitology-Mycology Service, Tropical Medicine Program, University Hospital of Tours, CEPR - Inserm U1100, Medical Faculty, François Rabelais University, Tours, France
| | - Carolyn Cray
- Department of Pathology and Laboratory Medicine, Division of Comparative Pathology, Miller School of Medicine, University of Miami, Miami, Florida, USA.,
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Lan H, Wu L, Sun R, Yang K, Liu Y, Wu J, Geng L, Huang C, Wang S. Investigation of Aspergillus flavus in animal virulence. Toxicon 2018; 145:40-47. [PMID: 29481813 DOI: 10.1016/j.toxicon.2018.02.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 02/11/2018] [Accepted: 02/23/2018] [Indexed: 11/25/2022]
Abstract
Aspergillus flavus is a common fungal pathogen of plants, animals and humans. Recently, many genes of A. flavus have been reported involving in regulation of pathogenesis in crops, but whether these genes are involved in animal virulence is still unknown. Here, we used a previous easy-to-use infection model for A. flavus based on mouse model by intravenous inoculation of A. flavus conidia. The outcome of infections in mice model showed that A. flavus NRRL3357 and laboratory strain CA14 PTS were both in dose dependent manner and highly reproducible. The progress of disease could be monitored by mice survival and histology analysis. Fungal burden analysis indicated it was gradually decreased within 7 days after infection. Moreover, aspergillosis caused by A. flavus significantly up-regulated gene expression levels of immune response mediators, including INF-γ, TNF-α, Dectin-1 and TLR2. Furthermore, the defined deletion A. flavus strains that previously displayed virulence in crop infection were also determined in this mouse model, and the results showed comparable degrees of infection in mice. Our results suggested that intravenous inoculation of conidia could be a suitable model for testing different A. flavus mutants in animal virulence. We hope to use this model to determine distinct A. flavus strains virulence in animals and study novel therapeutic methods to help control fungus diseases in the future.
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Affiliation(s)
- Huahui Lan
- Fujian Key Laboratory of Pathogenic Fungi Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Lianghuan Wu
- Fujian Key Laboratory of Pathogenic Fungi Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Ruilin Sun
- Fujian Key Laboratory of Pathogenic Fungi Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Kunlong Yang
- Fujian Key Laboratory of Pathogenic Fungi Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Yinghang Liu
- Fujian Key Laboratory of Pathogenic Fungi Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Jiefei Wu
- Fujian Key Laboratory of Pathogenic Fungi Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Longpo Geng
- Fujian Key Laboratory of Pathogenic Fungi Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Chuanzhong Huang
- Immuno-Oncology Laboratory of Fujian Cancer Hospital, Fujian Medical University Cancer Hospital, Fujian Provincial Key Laboratory of Translational Cancer Medicine, Fuzhou, Fujian, China
| | - Shihua Wang
- Fujian Key Laboratory of Pathogenic Fungi Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
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15
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Sosa L, Clares B, Alvarado HL, Bozal N, Domenech O, Calpena AC. Amphotericin B releasing topical nanoemulsion for the treatment of candidiasis and aspergillosis. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2017; 13:2303-2312. [DOI: 10.1016/j.nano.2017.06.021] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Revised: 06/22/2017] [Accepted: 06/28/2017] [Indexed: 10/19/2022]
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Desoubeaux G, Cray C. Rodent Models of Invasive Aspergillosis due to Aspergillus fumigatus: Still a Long Path toward Standardization. Front Microbiol 2017; 8:841. [PMID: 28559881 PMCID: PMC5432554 DOI: 10.3389/fmicb.2017.00841] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 04/24/2017] [Indexed: 01/09/2023] Open
Abstract
Invasive aspergillosis has been studied in laboratory by the means of plethora of distinct animal models. They were developed to address pathophysiology, therapy, diagnosis, or miscellaneous other concerns associated. However, there are great discrepancies regarding all the experimental variables of animal models, and a thorough focus on them is needed. This systematic review completed a comprehensive bibliographic analysis specifically-based on the technical features of rodent models infected with Aspergillus fumigatus. Out the 800 articles reviewed, it was shown that mice remained the preferred model (85.8% of the referenced reports), above rats (10.8%), and guinea pigs (3.8%). Three quarters of the models involved immunocompromised status, mainly by steroids (44.4%) and/or alkylating drugs (42.9%), but only 27.7% were reported to receive antibiotic prophylaxis to prevent from bacterial infection. Injection of spores (30.0%) and inhalation/deposition into respiratory airways (66.9%) were the most used routes for experimental inoculation. Overall, more than 230 distinct A. fumigatus strains were used in models. Of all the published studies, 18.4% did not mention usage of any diagnostic tool, like histopathology or mycological culture, to control correct implementation of the disease and to measure outcome. In light of these findings, a consensus discussion should be engaged to establish a minimum standardization, although this may not be consistently suitable for addressing all the specific aspects of invasive aspergillosis.
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Affiliation(s)
- Guillaume Desoubeaux
- Division of Comparative Pathology, Department of Pathology and Laboratory Medicine, Miller School of Medicine, University of MiamiMiami, FL, USA.,Service de Parasitologie-Mycologie-Médecine tropicale, Centre Hospitalier Universitaire de ToursTours, France.,Centre d'Etude des Pathologies Respiratoires (CEPR) Institut National de la Santé et de la Recherche Médicale U1100/Équipe 3, Université François-RabelaisTours, France
| | - Carolyn Cray
- Division of Comparative Pathology, Department of Pathology and Laboratory Medicine, Miller School of Medicine, University of MiamiMiami, FL, USA
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Anand R, Shankar J, Tiwary BN, Singh AP. Aspergillus flavus induces granulomatous cerebral aspergillosis in mice with display of distinct cytokine profile. Cytokine 2015; 72:166-72. [PMID: 25647272 DOI: 10.1016/j.cyto.2015.01.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 12/05/2014] [Accepted: 01/07/2015] [Indexed: 11/16/2022]
Abstract
Aspergillus flavus is one of the leading Aspergillus spp. resulting in invasive aspergillosis of central nervous system (CNS) in human beings. Immunological status in aspergillosis of central nervous system remains elusive in case of both immunocompetent and immunocompromised patients. Since cytokines are the major mediators of host response, evaluation of disease pathology along with cytokine profile in brain may provide snapshots of neuro-immunological response. An intravenous model of A. flavus infection was utilized to determine the pathogenicity of infection and cytokine profile in the brain of male BALB/c mice. Enumeration of colony forming units and histopathological analyses were performed on the brain tissue at distinct time periods. The kinetics of cytokines (TNF-α, IFN-γ, IL-12/IL-23p40, IL-6, IL-23, IL-17A and IL-4) was evaluated at 6, 12, 24, 48, 72 and 96h post infection (hPI) in brain homogenates using murine cytokine specific enzyme linked immunosorbent assay. Histological analysis exhibited the hyphae with leukocyte infiltrations leading to formation of granulomata along with ischemia and pyknosis of neurons in the brain of infected mice. Diseased mice displayed increased secretion of IFN-γ, IL-12p40 and IL-6 with a concomitant reduction in the secretion of Th2 cytokine IL-4, and Th17 promoting cytokine, IL-23 during the late phase of infection. A.flavus induced inflammatory granulomatous cerebral aspergillosis in mice, characterized by a marked increase in the Th1 cytokines and neurons undergoing necrosis. A marked increase in necrosis of neurons with concurrent inflammatory responses might have led to the host mortality during late phase of infection.
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Affiliation(s)
- R Anand
- Infectious Diseases Laboratory, National Institute of Immunology, New Delhi 110067, India.
| | - J Shankar
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Solan, HP 173234, India
| | - B N Tiwary
- Department of Biotechnology, Guru Ghasidas Vishwavidyalaya, Bilaspur, C.G. 495009, India
| | - A P Singh
- Infectious Diseases Laboratory, National Institute of Immunology, New Delhi 110067, India.
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18
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Susceptibility profiles of amphotericin B and posaconazole against clinically relevant mucorales species under hypoxic conditions. Antimicrob Agents Chemother 2014; 59:1344-6. [PMID: 25451049 DOI: 10.1128/aac.04424-14] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The effect of hypoxic conditions on the in vitro efficacy of amphotericin B and posaconazole against Mucorales was evaluated by defining MICs with Etest and broth microdilution and identifying minimal fungicidal concentrations (MFCs). With Etest, oxygen-dependent changes were detected, while the MIC and the MFC determined with broth microdilution remained unaltered with reduced oxygen levels. The observed differences depended on the method used.
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Susceptibility breakpoints for amphotericin B and Aspergillus species in an in vitro pharmacokinetic-pharmacodynamic model simulating free-drug concentrations in human serum. Antimicrob Agents Chemother 2014; 58:2356-62. [PMID: 24514094 DOI: 10.1128/aac.02661-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although conventional amphotericin B was for many years the drug of choice and remains an important agent against invasive aspergillosis, reliable susceptibility breakpoints are lacking. Three clinical Aspergillus isolates (Aspergillus fumigatus, Aspergillus flavus, and Aspergillus terreus) were tested in an in vitro pharmacokinetic-pharmacodynamic model simulating the biphasic 24-h time-concentration profile of free amphotericin B concentrations in human serum with free peak concentrations (fCmax) of 0.1, 0.3, 0.6, 1.2, and 2.4 mg/liter administered once daily. Drug concentrations were measured with a bioassay, and fungal growth was monitored for 72 h with galactomannan production. The fCmax/MIC corresponding to half-maximal activity (P50) was determined for each species, and the percentage of target attainment was calculated for different MICs for the standard (1 mg/kg of body weight) and a lower (0.6-mg/kg) dose of amphotericin B with Monte Carlo simulation analysis. The fCmax/MICs (95% confidence intervals) corresponding to P50 were 0.145 (0.133 to 0.158), 0.371 (0.283 to 0.486), and 0.41 (0.292 to 0.522) for A. fumigatus, A. flavus, and A. terreus, respectively. The median percentages of P50 attainment were ≥88%, 47%, and 0% for A. fumigatus isolates with MICs of ≤0.5, 1, and ≥2 mg/liter, respectively, and ≥81%, 24%, and 0% and ≥75%, 15%, and 0% for A. flavus and A. terreus isolates with MICs of ≤0.25, 0.5, and ≥1 mg/liter, respectively. The lower dose of 0.6 mg/kg would retain efficacy for A. fumigatus, A. flavus, and A. terreus isolates with MICs of ≤0.25, ≤0.125, and ≤0.125 mg/liter, respectively. The susceptibility, intermediate susceptibility, and resistance breakpoints of ≤0.5, 1, and ≥2 mg/liter for A. fumigatus and ≤0.25, 0.5, and ≥1 mg/liter for A. flavus and A. terreus were determined for conventional amphotericin B with a pharmacokinetic-pharmacodynamic model simulating free-drug serum concentrations.
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20
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In vivo Pathogenicity Studies of Aspergilli in Lepidopteran Model Host Galleria Mellonella. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.apcbee.2014.03.043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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21
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Foley K, Fazio G, Jensen AB, Hughes WOH. The distribution of Aspergillus spp. opportunistic parasites in hives and their pathogenicity to honey bees. Vet Microbiol 2013; 169:203-10. [PMID: 24485932 DOI: 10.1016/j.vetmic.2013.11.029] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 11/22/2013] [Indexed: 01/27/2023]
Abstract
Stonebrood is a disease of honey bee larvae caused by fungi from the genus Aspergillus. As very few studies have focused on the epidemiological aspects of stonebrood and diseased brood may be rapidly discarded by worker bees, it is possible that a high number of cases go undetected. Aspergillus spp. fungi are ubiquitous and associated with disease in many insects, plants, animals and man. They are regarded as opportunistic pathogens that require immunocompromised hosts to establish infection. Microbiological studies have shown high prevalences of Aspergillus spp. in apiaries which occur saprophytically on hive substrates. However, the specific conditions required for pathogenicity to develop remain unknown. In this study, an apiary was screened to determine the prevalence and diversity of Aspergillus spp. fungi. A series of dose-response tests were then conducted using laboratory reared larvae to determine the pathogenicity and virulence of frequently occurring isolates. The susceptibility of adult worker bees to Aspergillus flavus was also tested. Three isolates (A. flavus, Aspergillus nomius and Aspergillus phoenicis) of the ten species identified were pathogenic to honey bee larvae. Moreover, adult honey bees were also confirmed to be highly susceptible to A. flavus infection when they ingested conidia. Neither of the two Aspergillus fumigatus strains used in dose-response tests induced mortality in larvae and were the least pathogenic of the isolates tested. These results confirm the ubiquity of Aspergillus spp. in the apiary environment and highlight their potential to infect both larvae and adult bees.
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Affiliation(s)
- Kirsten Foley
- Institute of Integrative and Comparative Biology, University of Leeds, Leeds LS2 9JT, UK.
| | - Géraldine Fazio
- Institute of Integrative and Comparative Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Annette B Jensen
- Department of Ecology and Agriculture, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
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Single-dose pharmacodynamics of amphotericin B against Aspergillus species in an in vitro pharmacokinetic/pharmacodynamic model. Antimicrob Agents Chemother 2013; 57:3713-8. [PMID: 23716054 DOI: 10.1128/aac.02484-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Conventional MIC testing of amphotericin B results in narrow MIC ranges challenging the detection of resistant strains. In order to discern amphotericin B pharmacodynamics, the in vitro activity of amphotericin B was studied against Aspergillus isolates with the same MICs by using a new in vitro pharmacokinetic/pharmacodynamic (PK/PD) model that simulates amphotericin B human plasma levels. Clinical isolates of Aspergillus fumigatus, A. terreus, and A. flavus with the same Clinical and Laboratory Standards Institute modal MICs of 1 mg/liter were exposed to amphotericin B concentrations following the plasma concentration-time profile after single-bolus administration with C(max) values of 0.6, 1.2, 2.4, and 4.8 mg/liter. Fungal growth was monitored for up to 72 h based on galactomannan production. Complete growth inhibition was observed only against A. fumigatus with amphotericin B with a Cmax of ≥ 2.4 mg/liter. At the lower C(max) values 0.6 and 1.2 mg/liter, significant growth delays of 34 and 52 h were observed, respectively (P < 0.001). For A. flavus, there was no complete inhibition but a progressive growth delay of 1 to 50 h at an amphotericin B C(max) of 0.6 to 4.8 mg/liter (P < 0.001). For A. terreus, the growth delay was modest (up to 8 h) at all C(max)s (P < 0.05). The C(max) (95% confidence interval) associated with 50% activity for A. fumigatus was 0.60 (0.49 to 0.72) mg/liter, which was significantly lower than for A. flavus 3.06 (2.46 to 3.80) mg/liter and for A. terreus 7.90 (5.20 to 12.29) mg/liter (P < 0.001). A differential in vitro activity of amphotericin B was found among Aspergillus species despite the same MIC in the order A. fumigatus > A. flavus > A. terreus in the in vitro PK/PD model, possibly reflecting the different concentration- and time-dependent inhibitory/killing activities amphotericin B exerted against these species.
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Hadrich I, Neji S, Drira I, Trabelsi H, Mahfoud N, Ranque S, Makni F, Ayadi A. Microsatellite typing of Aspergillus flavus in patients with various clinical presentations of aspergillosis. Med Mycol 2013; 51:586-91. [PMID: 23336695 DOI: 10.3109/13693786.2012.761359] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Aspergillus flavus is the second most important Aspergillus species associated with aspergillosis and the incidence of infections caused by it are increasing in the immunocompromised population. This species is of major epidemiological importance in regions with a dry and hot climate. Despite the growing clinical significance of A. flavus, data on its molecular epidemiology are scarce. This study was aimed at examining whether isolates from distinct genotypes were involved in distinct clinical forms of aspergillosis. Sixty-three clinical isolates of A. flavus recovered from 35 patients with various clinical presentations of aspergillosis were characterized by microsatellite typing. The highest discriminatory power for a single locus was obtained with the AFLA1 marker, which had 14 distinct alleles and a 0.903 D value. The combination of all six markers yielded 48 different genotypes with a 0.994 D value. There was a considerable genetic diversity in the isolates and patients with invasive aspergillosis were usually colonized by multiples genotypes. There was no evidence that a given genotype was associated with a particular clinical presentation of A. flavus aspergillosis. The occurrence of more than one genotype in clinical samples indicates that a patient may be infected by multiple genotypes and that any particular isolate from a clinical specimen may not necessarily be the one causing aspergillosis.
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Affiliation(s)
- Inès Hadrich
- Laboratoire de biologie moléculaire parasitaire et fongique, Faculté de Médecine de Sfax, Sfax, Tunisia
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Inhibitory and fungicidal effects of antifungal drugs against Aspergillus species in the presence of serum. Antimicrob Agents Chemother 2013; 57:1625-31. [PMID: 23318807 DOI: 10.1128/aac.01573-12] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Given the high protein binding rates of antifungal drugs and the effect of serum proteins on Aspergillus growth, we investigated the in vitro pharmacodynamics of amphotericin B, voriconazole, and three echinocandins in the presence of human serum, assessing both inhibitory and fungicidal effects. In vitro inhibitory (IC) and fungicidal (FC) concentrations against 5 isolates of Aspergillus fumigatus, Aspergillus flavus, and Aspergillus terreus were determined with a CLSI M38-A2-based microdilution method using the XTT methodology after 48 h of incubation at 35 °C with a medium supplemented with 50% human serum. In the presence of serum, the IC and FC of amphotericin B and the IC of echinocandins were increased (1.21- to 13.44-fold), whereas voriconazole IC and FC were decreased (0.22- to 0.90-fold). The amphotericin B and voriconazole FC/IC ratios did not change significantly (0.59- to 2.33-fold) in the presence of serum, indicating that the FC increase was due to the IC increase. At echinocandin concentrations above the minimum effective concentration (MEC), fungal growth was reduced by 10 to 50% in the presence of human serum, resulting in complete inhibition of growth for some isolates. Thus, the in vitro activities of amphotericin B and echinocandins were reduced, whereas that of voriconazole was enhanced, in the presence of serum. These changes could not be predicted by the percentage of protein binding, indicating that other factors and/or secondary mechanisms may account for the observed in vitro activities of antifungal drugs against Aspergillus species in the presence of serum.
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25
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Anand R, Shankar J, Singh AP, Tiwary BN. Cytokine milieu in renal cavities of immunocompetent mice in response to intravenous challenge of Aspergillus flavus leading to aspergillosis. Cytokine 2012; 61:63-70. [PMID: 23063795 DOI: 10.1016/j.cyto.2012.08.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2011] [Revised: 07/01/2012] [Accepted: 08/24/2012] [Indexed: 12/22/2022]
Abstract
Investigations in mice have demonstrated that Aspergillus flavus is more virulent than all other Aspergillus species except A. tamari. However, there is a complete lack of information on the immune responses elicited by A. flavus in systemic model. This communication reports the progression of infection and cytokine profile in BALB/c mice in response to intravenous challenge of A. flavus. The pathogenesis of infection was evaluated morphologically and by the analysis of Colony Forming Units (CFUs) in kidney homogenates. The kinetics of regulated cytokines was determined in kidneys by cytokine-specific murine ELISA. During the initial phase of infection the rate of clearance of A. flavus was high, most likely through recruited neutrophils and the resident renal macrophages with concurrent significant release of pro-inflammatory cytokines (IFN-γ, TNF-α, IL-12/IL-23p40, IL-6) indicating antifungal innate immune response to be active at the site. However, at 24h PI there was a significant rise of IL-17 and IL-23 suggesting the activation of IL-17/IL-23 axis of inflammation resulting in rise of CFU. The lack of significant induction in the anti-inflammatory cytokines like IL-4 and IL-10 confirmed the absence of Th2 type of response. In the late phase, after 3days post-infection, there was a rise in the number of pathogen in the kidneys as determined by histopathology and CFU counts. The A. flavus hyphae were evident in the renal pelvis and ureter and we propose the production of blastoconidia by metamorphosed hyphae.
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Affiliation(s)
- Rajesh Anand
- Microbial & Molecular Genetics Laboratory, Department of Botany, Patna University, Patna 800 005, India.
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Pharmacodynamic effects of simulated standard doses of antifungal drugs against Aspergillus species in a new in vitro pharmacokinetic/pharmacodynamic model. Antimicrob Agents Chemother 2011; 56:403-10. [PMID: 22064546 DOI: 10.1128/aac.00662-11] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In conventional ΜΙC tests, fungi are exposed to constant drug concentrations, whereas in vivo, fungi are exposed to changing drug concentrations. Therefore, we developed a new in vitro pharmacokinetic/pharmacodynamic model where human plasma pharmacokinetics of standard doses of 1 mg/kg amphotericin B, 4 mg/kg voriconazole, and 1 mg/kg caspofungin were simulated and their pharmacodynamic characteristics were determined against three clinical isolates of Aspergillus fumigatus, Aspergillus flavus, and Aspergillus terreus with identical MICs (1 mg/liter for amphotericin B, 0.5 mg/liter for voriconazole) and minimum effective concentrations (0.5 mg/liter for caspofungin). This new model consists of an internal compartment (a 10-ml dialysis tube made out of a semipermeable cellulose membrane allowing the free diffusion of antifungals but not galactomannan) inoculated with Aspergillus conidia and placed inside an external compartment (a 700-ml glass beaker) whose content is diluted after the addition of antifungal drugs by a peristaltic pump at the same rate as the clearance of the antifungal drugs in human plasma. Fungal growth was assessed by galactomannan production. Despite demonstrating the same MICs, amphotericin B completely inhibited (100%) A. fumigatus but not A. flavus and A. terreus, whose growth was delayed for 7.53 and 22.8 h, respectively. Voriconazole partially inhibited A. fumigatus (49.5%) and Α. flavus (27.9%) but not Α. terreus; it delayed their growth by 3.99 h (A. fumigatus) and 5.37 h (Α. terreus). Caspofungin did not alter galactomannan production in all of the species but A. terreus. The new model simulated human pharmacokinetics of antifungal drugs and revealed important pharmacodynamic differences in their activity.
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Differences in efficacy and cytokine profiles following echinocandin or liposomal amphotericin B monotherapy or combination therapy for murine pulmonary or systemic Aspergillus flavus infections. Antimicrob Agents Chemother 2011; 56:218-30. [PMID: 21968353 DOI: 10.1128/aac.00607-11] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Given the recent increase in aspergillosis caused by species other than Aspergillus fumigatus, micafungin, caspofungin, and liposomal amphotericin B (L-AmBi) were investigated as monotherapy or combination therapy for murine systemic or pulmonary Aspergillus flavus infection. Treatment for 3 or 6 days was begun at 24 h (intravenous [i.v.], 2.8 × 10(4) conidia) or 2 h (intranasal, 4.1 × 10(6) to 6.75 × 10(6) conidia) postchallenge as follows: 5 or 10 mg/kg L-AmBi, 10 mg/kg caspofungin, 15 mg/kg micafungin, L-AmBi plus echinocandin, L-AmBi on days 1 to 3 and echinocandin on days 4 to 6, or echinocandin on days 1 to 3 and L-AmBi on days 4 to 6. Mice were monitored for survival, fungal burden, serum or tissue cytokines, and lung histopathology. In the systemic infection, micafungin or caspofungin was more effective than L-AmBi in prolonging survival (P < 0.05), and L-AmBi was associated with significantly elevated serum levels of interleukin-6 (IL-6), macrophage inflammatory protein 1α (MIP-1α), and IL-12 (P < 0.05). In contrast, L-AmBi was significantly more effective than the echinocandins in reducing fungal growth in most tissues (P < 0.05). Concomitant therapies produced significantly enhanced survival, reduction in fungal burden, and low levels of proinflammatory cytokines, while antagonism was seen with some sequential regimens. In comparison, in the pulmonary infection, L-AmBi was significantly better (P < 0.05) than caspofungin or the combination of L-AmBi and caspofungin in prolonging survival and reducing lung fungal burden. Caspofungin stimulated high lung levels of IL-1α, tumor necrosis factor alpha (TNF-α), and IL-6, with extensive tissue damage. In summary, systemic A flavus infection was treated effectively with L-AmBi plus micafungin or caspofungin provided that the drugs were administered concomitantly and not sequentially, while pulmonary A. flavus infection responded well to L-AmBi but not to caspofungin.
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Guarro J. Lessons from animal studies for the treatment of invasive human infections due to uncommon fungi. J Antimicrob Chemother 2011; 66:1447-66. [PMID: 21493649 DOI: 10.1093/jac/dkr143] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Clinical experience in the management of opportunistic infections, especially those caused by less common fungi, is, due to their rarity, very scarce; therefore, the most effective treatments remain unknown. The ever-increasing numbers of fungal infections due to opportunistic fungi have repeatedly proven the limitations of the antifungal armamentarium. Moreover, some of these fungi, such as Fusarium spp. or Scedosporium spp., are innately resistant to almost all the available antifungal drugs, which makes the development of new and effective therapies a high priority. Since it is difficult to conduct randomized clinical trials in these uncommon mycoses, the use of animal models is a good alternative for evaluating new therapies. This is an extensive review of the numerous studies that have used animal models for this purpose against a significant number of less common fungi. A table describing the different studies performed on the efficacy of the different drugs tested is included for each fungal species. In addition, there is a summary table showing the conclusions that can be derived from the analysis of the studies and listing the drugs that showed the best results. Considering the wide variability in the response to the antifungals that the different strains of a given species can show, the table highlights the drugs that showed positive results using at least two parameters for evaluating efficacy against at least two different strains without showing any negative results. These data can be very useful for guiding the treatment of rare infections when there is very little experience or when controversial results exist, or when treatment fails.
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Affiliation(s)
- Josep Guarro
- Mycology Unit, Medical School, IISPV, Rovira i Virgili University, 43201 Reus, Spain.
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Rudramurthy SM, de Valk HA, Chakrabarti A, Meis JFGM, Klaassen CHW. High resolution genotyping of clinical Aspergillus flavus isolates from India using microsatellites. PLoS One 2011; 6:e16086. [PMID: 21264229 PMCID: PMC3022034 DOI: 10.1371/journal.pone.0016086] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Accepted: 12/06/2010] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Worldwide, Aspergillus flavus is the second leading cause of allergic, invasive and colonizing fungal diseases in humans. However, it is the most common species causing fungal rhinosinusitis and eye infections in tropical countries. Despite the growing challenges due to A. flavus, the molecular epidemiology of this fungus has not been well studied. We evaluated the use of microsatellites for high resolution genotyping of A. flavus from India and a possible connection between clinical presentation and genotype of the involved isolate. METHODOLOGY/PRINCIPAL FINDINGS A panel of nine microsatellite markers were selected from the genome of A. flavus NRRL 3357. These markers were used to type 162 clinical isolates of A. flavus. All nine markers proved to be polymorphic displaying up to 33 alleles per marker. Thirteen isolates proved to be a mixture of different genotypes. Among the 149 pure isolates, 124 different genotypes could be recognized. The discriminatory power (D) for the individual markers ranged from 0.657 to 0.954. The D value of the panel of nine markers combined was 0.997. The multiplex multicolor approach was instrumental in rapid typing of a large number of isolates. There was no correlation between genotype and the clinical presentation of the infection. CONCLUSIONS/SIGNIFICANCE There is a large genotypic diversity in clinical A. flavus isolates from India. The presence of more than one genotype in clinical samples illustrates the possibility that persons may be colonized by multiple genotypes and that any isolate from a clinical specimen is not necessarily the one actually causing infection. Microsatellites are excellent typing targets for discriminating between A. flavus isolates from various origins.
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Affiliation(s)
- Shivaprakash M. Rudramurthy
- Mycology Division, Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Hanneke A. de Valk
- Department of Medical Microbiology and Infectious Diseases, Canisius Wilhelmina Hospital, Nijmegen, The Netherlands
| | - Arunaloke Chakrabarti
- Mycology Division, Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Jacques F. G. M. Meis
- Department of Medical Microbiology and Infectious Diseases, Canisius Wilhelmina Hospital, Nijmegen, The Netherlands
| | - Corné H. W. Klaassen
- Department of Medical Microbiology and Infectious Diseases, Canisius Wilhelmina Hospital, Nijmegen, The Netherlands
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Th1 and Th2 cytokines in a self-healing primary pulmonary Aspergillus flavus infection in BALB/c mice. Cytokine 2010; 52:258-64. [PMID: 20800507 DOI: 10.1016/j.cyto.2010.07.428] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 07/14/2010] [Accepted: 07/30/2010] [Indexed: 01/04/2023]
Abstract
Studies with non-immunocompromised mice have demonstrated that Aspergillus flavus is more virulent than almost all other Aspergillus species. However, the type of immune response this fungus induces in mammals has not been investigated thoroughly. The study was carried out to analyze the sequential pathogenesis of pulmonary A. flavus infection and the role of cytokines in host response in BALB/c mice. Two distinct phases were observed in mice: First, an intense rate of clearance of A. flavus occurred, most likely through recruited neutrophils and the resident alveolar macrophages with concurrent release of pro-inflammatory cytokines and second, fungal and cellular debris were cleaned by recruited monocytes, pro-inflammatory cytokine production rapidly decreased and infection self-healed. The pro-inflammatory cytokine IFN-γ demonstrated an upward trend up to 24h PI followed by a steady decline. The titers of TNF-α (a pro-inflammatory Th1 cytokine) were, however, inversely related to the titers of IL-10 an anti-inflammatory Th2 cytokine. The anti-inflammatory cytokine IL-4 showed slightly decreasing trend between 12 and 48 h PI, beyond that it again reached to the titers observed at 6h PI. The infected mice produced signs of Th1 type response with self healing capabilities.
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Verweij PE, Howard SJ, Melchers WJ, Denning DW. Azole-resistance in Aspergillus: Proposed nomenclature and breakpoints. Drug Resist Updat 2009; 12:141-7. [DOI: 10.1016/j.drup.2009.09.002] [Citation(s) in RCA: 209] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2009] [Accepted: 06/08/2009] [Indexed: 11/24/2022]
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32
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Pasqualotto AC. Differences in pathogenicity and clinical syndromes due to Aspergillus fumigatus and Aspergillus flavus. Med Mycol 2008; 47 Suppl 1:S261-70. [PMID: 18654921 DOI: 10.1080/13693780802247702] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Most of the information available about Aspergillus infections has originated from the study of A. fumigatus, the most frequent species in the genus. This review aims to compare the pathogenicity and clinical aspects of Aspergillosis caused by A. fumigatus an A. flavus. Experimental data suggests that A. flavus is more virulent than A. fumigatus. However, these were mostly models of disseminated Aspergillus infection which do not properly mimic the physiopathology of invasive aspergillosis, a condition that is usually acquired by inhalation. In addition, no conclusive virulence factor has been identified for Aspergillus species. A. flavus is a common cause of fungal sinusitis and cutaneous infections. Chronic conditions such as chronic cavitary pulmonary aspergillosis and sinuses fungal balls have rarely been associated with A. flavus. The bigger size of A. flavus spores, in comparison to those of A. fumigatus spores, may favour their deposit in the upper respiratory tract. Differences between these species justify the need for a better understanding of A. flavus infections.
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Affiliation(s)
- Alessandro C Pasqualotto
- Infection Control Department at Santa Casa Complexo Hospitalar, Porto Alegre, and Post-Graduation Program in Pulmonary Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.
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Ozkutuk A, Ergon C, Metin DY, Yucesoy M, Polat SH. Comparison of disk diffusion, E-test and broth microdilution test in determination of susceptibility of Aspergillus species to amphotericin B, itraconazole and voriconazole. J Chemother 2008; 20:87-92. [PMID: 18343749 DOI: 10.1179/joc.2008.20.1.87] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
In response to the recent increase in Aspergillus infections, new antifungal agents have become available accompanied by studies on antifungal susceptibility tests for epidemiological follow-up. The aim of this study was to compare the efficacy of Clinical Laboratory Standards Institute (CLSI) M 38-A broth microdilution test with the disk diffusion and E-test in determining the susceptibility of Aspergillus spp. to amphotericin B, itraconazole and voriconazole. The study was carried out on 18 A. fumigatus, 7 A. flavus, 5 A. niger and 2 A. versicolor strains isolated from clinical samples. The microdilution method was performed by following the instructions of CLSI M 38-A. The E-test and disk diffusion tests were performed according to the instructions of their manufacturers. The percent agreement between the E-test and CLSI M38-A broth microdilution test at 24 (48) h within +/- 2 dilutions was, respectively, 81% (69%) for amphotericin B, 75% (72%) for itraconazole and 85% (81%) for voriconazole. The disk diffusion test showed good correlation with the E-test but poor correlation with the broth microdilution test for the three antifungal agents we tested. In conclusion, E-test and disk diffusion test have their advantages such as ease of application and interpretation, but their correlation with the broth microdilution should be improved.
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Affiliation(s)
- A Ozkutuk
- Dokuz Eylul University School of Medicine, Department of Infectious Disease and Clinical Microbiology, Izmur, Turkey.
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Li DM, Xiu DR, Li RY, Samson R, De Hoog G, Wang DL. Aspergillus flavus myositis in a patient after liver transplantation. Clin Transplant 2008; 22:508-11. [DOI: 10.1111/j.1399-0012.2008.00801.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
Antifungal susceptibility testing is a very dynamic field of medical mycology. Standardization of in vitro susceptibility tests by the Clinical and Laboratory Standards Institute (CLSI) and the European Committee for Antimicrobial Susceptibility Testing (EUCAST), and current availability of reference methods constituted the major remarkable steps in the field. Based on the established minimum inhibitory concentration (MIC) breakpoints, it is now possible to determine the susceptibilities of Candida strains to fluconazole, itraconazole, voriconazole, and flucytosine. Moreover, utility of fluconazole antifungal susceptibility tests as an adjunct in optimizing treatment of candidiasis has now been validated. While the MIC breakpoints and clinical significance of susceptibility testing for the remaining fungi and antifungal drugs remain yet unclear, modifications of the available methods as well as other methodologies are being intensively studied to overcome the present drawbacks and limitations. Among the other methods under investigation are Etest, colorimetric microdilution, agar dilution, determination of fungicidal activity, flow cytometry, and ergosterol quantitation. Etest offers the advantage of practical application and favorable agreement rates with the reference methods that are frequently above acceptable limits. However, MIC breakpoints for Etest remain to be evaluated and established. Development of commercially available, standardized colorimetric panels that are based on CLSI method parameters has added more to the antifungal susceptibility testing armamentarium. Flow cytometry, on the other hand, appears to offer rapid susceptibility testing but requires specified equipment and further evaluation for reproducibility and standardization. Ergosterol quantitation is another novel approach, which appears potentially beneficial particularly in discrimination of azole-resistant isolates from heavy trailers. The method is yet investigational and requires to be further studied. Developments in methodology and applications of antifungal susceptibility testing will hopefully provide enhanced utility in clinical guidance of antifungal therapy. However, and particularly in immunosuppressed host, in vitro susceptibility is and will remain only one of several factors that influence clinical outcome.
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Affiliation(s)
- Sevtap Arikan
- Department of Microbiology and Clinical Microbiology, Hacettepe University Medical School, Ankara, Turkey.
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Herbrecht R, Flückiger U, Gachot B, Ribaud P, Thiebaut A, Cordonnier C. Treatment of invasive Candida and invasive Aspergillus infections in adult haematological patients. EJC Suppl 2007. [DOI: 10.1016/j.ejcsup.2007.06.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Araujo R, Pina-Vaz C, Rodrigues AG. Susceptibility of environmental versus clinical strains of pathogenic Aspergillus. Int J Antimicrob Agents 2007; 29:108-11. [PMID: 17189101 DOI: 10.1016/j.ijantimicag.2006.09.019] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2006] [Revised: 09/25/2006] [Accepted: 09/26/2006] [Indexed: 11/26/2022]
Abstract
The objective of this study was to compare the antifungal susceptibility profiles of 307 environmental strains and 139 clinical isolates of Aspergillus belonging to six different species. Clinical and environmental strains with minimal inhibitory concentrations (MICs) or minimal effective concentrations >or=4microg/mL to amphotericin B (AMB), itraconazole (ITC), voriconazole and caspofungin were seldom detected. However, the susceptibility profile of environmental Aspergillus non-fumigatus strains suggests a native reduced susceptibility of Aspergillus flavus and Aspergillus terreus to AMB. A single environmental strain of Aspergillus nidulans showed high in vitro resistance (MIC>or=16 microg/mL) to ITC. Aspergillus niger showed significantly higher MIC values to ITC compared with the other Aspergillus spp. Conversely, A. fumigatus and Aspergillus glaucus showed higher susceptible profiles to the antifungals. Definition of the breakpoints for the antifungal agents remains urgent. The relationship between the susceptibility pattern and the pathogenic potential also deserves more attention, particularly with regard to non-fumigatus species.
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Affiliation(s)
- Ricardo Araujo
- Department of Microbiology, Faculty of Medicine, University of Porto, Alameda Prof. Hernani Monteiro, 4200-319 Porto, Portugal.
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Chamilos G, Kontoyiannis DP. Update on antifungal drug resistance mechanisms of Aspergillus fumigatus. Drug Resist Updat 2006; 8:344-58. [PMID: 16488654 DOI: 10.1016/j.drup.2006.01.001] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2005] [Revised: 01/09/2006] [Accepted: 01/11/2006] [Indexed: 10/25/2022]
Abstract
Although the arsenal of agents with anti-Aspergillus activity has expanded over the last decade, mortality due to invasive aspergillosis (IA) remains unacceptably high. Aspergillus fumigatus still accounts for the majority of cases of IA; however less susceptible to antifungals non-fumigatus aspergilli began to emerge. Antifungal drug resistance of Aspergillus might partially account for treatment failures. Recent advances in our understanding of mechanisms of antifungal drug action in Aspergillus, along with the standardization of in vitro susceptibility testing methods, has brought resistance testing to the forefront of clinical mycology. In addition, molecular biology has started to shed light on the mechanisms of resistance of A. fumigatus to azoles and the echinocandins, while genome-based assays show promise for high-throughput screening for genotypic antifungal resistance. Several problems remain, however, in the study of this complex area. Large multicenter clinical studies--point prevalence or longitudinal--to capture the incidence and prevalence of antifungal resistance in A. fumigatus isolates are lacking. Correlation of in vitro susceptibility with clinical outcome and susceptibility breakpoints has not been established. In addition, the issue of cross-resistance between the newer triazoles is of concern. Furthermore, in vitro resistance testing for polyenes and echinocandins is difficult, and their mechanisms of resistance are largely unknown. This review examines challenges in the diagnosis, epidemiology, and mechanisms of antifungal drug resistance in A. fumigatus.
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Affiliation(s)
- G Chamilos
- Department of Infectious Diseases, Infection Control and Employee Health, Unit 402, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
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Clemons KV, Stevens DA. Animal models ofAspergillusinfection in preclinical trials, diagnostics and pharmacodynamics: What can we learn from them? Med Mycol 2006; 44:S119-S126. [DOI: 10.1080/13693780600871174] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Clemons KV, Stevens DA. The contribution of animal models of aspergillosis to understanding pathogenesis, therapy and virulence. Med Mycol 2005; 43 Suppl 1:S101-10. [PMID: 16110800 DOI: 10.1080/13693780500051919] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Animal models of aspergillosis have been used extensively to study various aspects of pathogenesis, innate and acquired host-response, disease transmission and therapy. Several different animal models of aspergillosis have been developed. Because aspergillosis is an important pulmonary disease in birds, avian models have been used successfully to study preventative vaccines. Studies done to emulate human disease have relied on models using common laboratory animal species. Guinea pig models have primarily been used in therapy studies of invasive pulmonary aspergillosis (IPA). Rabbits have been used to study IPA and systemic disease, as well as fungal keratitis. Rodent, particularly mouse, models of aspergillosis predominate as the choice for most investigators. The availability of genetically defined strains of mice, immunological reagents, cost and ease of handling are factors. Both normal and immunosuppressed animals are used routinely. These models have been used to determine efficacy of experimental therapeutics, comparative virulence of different isolates of Aspergillus, genes involved in virulence, and susceptibility to infection with Aspergillus. Mice with genetic immunological deficiency and cytokine gene-specific knockout mice facilitate studies of the roles cells, and cytokines and chemokines, play in host-resistance to Aspergillus. Overall, these models have been critical to the advancement of therapy, and our current understanding of pathogenesis and host-resistance.
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Affiliation(s)
- K V Clemons
- California Institute for Medical Research, San Jose, CA 95128, USA.
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Gomez-Lopez A, Aberkane A, Petrikkou E, Mellado E, Rodriguez-Tudela JL, Cuenca-Estrella M. Analysis of the influence of Tween concentration, inoculum size, assay medium, and reading time on susceptibility testing of Aspergillus spp. J Clin Microbiol 2005; 43:1251-5. [PMID: 15750092 PMCID: PMC1081276 DOI: 10.1128/jcm.43.3.1251-1255.2005] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The influence of several test variables on susceptibility testing of Aspergillus spp. was assessed. A collection of 28 clinical isolates was tested against amphotericin B, itraconazole, voriconazole, and terbinafine. Inoculum size (10(4) CFU/ml versus 10(5) CFU/ml) and glucose supplementation (0.2% versus 2%) did not have significant effects on antifungal susceptibility testing results and higher inoculum size and glucose concentration did not falsely elevate MICs. In addition, antifungal susceptibility testing procedure with an inoculum size of 10(5) CFU/ml distinctly differentiated amphotericin B or itraconazole-resistant Aspergillus strains in vivo from the susceptible ones. Time of incubation significantly affected the final values of MICs, showing major increases (two to six twofold dilutions, P < 0.01 by analysis of variance) between MIC readings at 24 and 48 h, but no differences were observed between antifungal susceptibility testing results obtained at 48 h and at 72 h. Significantly higher MICs were uniformly associated with higher concentrations of Tween (P < 0.01), used as a dispersing agent in the preparation of inoculum suspensions. The geometric mean MICs showed increases of between 1.5- and 10-fold when the Tween concentration varied from 0.1% (the geometric means for amphotericin B, itraconazole, voriconazole, and terbinafine were 1.29, 0.69, 1.06, and 0.64 mug/ml, respectively) to 5% (the geometric means for amphotericin B, itraconazole, voriconazole, and terbinafine were 1.97, 5.79, 1.60, and 4.66 mug/ml, respectively). The inhibitory effect of Tween was clearly increased with inoculum sizes of 10(5) CFU/ml and was particularly dramatic for itraconazole, terbinafine, and Aspergillus terreus. The inoculum effect was not observed when the Tween concentration was below 0.5% (P > 0.01).
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Affiliation(s)
- Alicia Gomez-Lopez
- Servicio de Micología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Ctra Majadahonda-Pozuelo, Km 2. 28220 Majadahonda, Madrid, Spain
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Hsueh PR, Lau YJ, Chuang YC, Wan JH, Huang WK, Shyr JM, Yan JJ, Yu KW, Wu JJ, Ko WC, Yang YC, Liu YC, Teng LJ, Liu CY, Luh KT. Antifungal susceptibilities of clinical isolates of Candida species, Cryptococcus neoformans, and Aspergillus species from Taiwan: surveillance of multicenter antimicrobial resistance in Taiwan program data from 2003. Antimicrob Agents Chemother 2005; 49:512-7. [PMID: 15673726 PMCID: PMC547329 DOI: 10.1128/aac.49.2.512-517.2005] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The susceptibilities of nonduplicate isolates to six antifungal agents were determined for 391 blood isolates of seven Candida species, 70 clinical isolates (from blood or cerebrospinal fluid) of Cryptococcus neoformans, and 96 clinical isolates of four Aspergillus species, which were collected in seven different hospitals in Taiwan (as part of the 2003 program of the study group Surveillance of Multicenter Antimicrobial Resistance in Taiwan). All isolates of Candida species other than C. glabrata and C. krusei were susceptible to fluconazole. Among the 59 C. glabrata isolates, 16 (27%) were not susceptible to fluconazole, and all were dose-dependently susceptible or resistant to itraconazole. For three (5.1%) C. glabrata isolates, voriconazole MICs were 2 to 4 microg/ml, and for all other Candida species isolates, voriconazole MICs were </=0.5 microg/ml. The proportions of isolates for which amphotericin B MICs were >/=2 microg/ml were 100% (3 isolates) for C. krusei, 11% (23 of 207 isolates) for Candida albicans, 3.0% (2 of 67 isolates) for Candida tropicalis, 20% (12 of 59 isolates) for C. glabrata, and 0% for both Candida parapsilosis and Candida lusitaniae. For three (4%) Cryptococcus neoformans isolates, fluconazole MICs were >/=16 microg/ml, and two (3%) isolates were not inhibited by 1 mug of amphotericin B/ml. For four (4.2%) of the Aspergillus isolates, itraconazole MICs were 8 microg/ml. Aspergillus flavus was less susceptible to amphotericin B, with the MICs at which 50% (1 microg/ml) and 90% (2 microg/ml) nsrsid417869\delrsid7301351 of isolates were inhibited being twofold greater than those for Aspergillus fumigatus and Aspergillus niger. All Aspergillus isolates were inhibited by </=1 microg of voriconazole/ml, including isolates with increased resistance to amphotericin B and itraconazole. This study revealed the emergence in Taiwan of decreased susceptibilities of Candida species to amphotericin B and of C. neoformans to fluconazole and amphotericin B. Voriconazole was the most potent agent against the fungal isolates tested, including fluconazole- and amphotericin B-nonsusceptible strains.
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Affiliation(s)
- Po-Ren Hsueh
- Department of Laboratory Medicine, National Taiwan University Hospital, No. 7 Chung-Shan South Rd., Taipei 100, Taiwan.
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Balajee SA, Marr KA. Conidial viability assay for rapid susceptibility testing of Aspergillus species. J Clin Microbiol 2002; 40:2741-5. [PMID: 12149322 PMCID: PMC120618 DOI: 10.1128/jcm.40.8.2741-2745.2002] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antifungal susceptibility testing of filamentous fungi has become more important given the recognition of drug-resistant organisms and the availability of therapies other than amphotericin B (AMB). As current microdilution and E-test methods are limited by a 2 to 3 day incubation time required to obtain results, a more rapid method for susceptibility testing of fungi is needed. We report here a flow cytometric assay that relies on conidial metabolism of the viability dye FUN-1. Conidia are incubated in media containing increasing concentrations of AMB for 3 h, exposed to FUN-1, and then analyzed by flow cytometry. Relative susceptibility to AMB can be measured both by forward and side scatter characteristics of the conidial population and by mean fluorescence intensity (MFI) of the dye. MIC, calculated as the concentration of AMB to yield 90% reduction in MFI relative to growth controls, was determined for 27 clinical isolates Aspergillus species and correlated well with the standard (i.e., NCCLS) method. The results of these studies illustrate a method by which AMB susceptibility can be rapidly and reproducibly determined by measuring conidial viability.
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Abstract
We susceptibility tested 17 clinical isolates of Aspergillus fumigatus, for most of which MICs of itraconazole were elevated (MIC at which 50% of the isolates tested are inhibited, 16 microg/ml), against itraconazole, posaconazole, ravuconazole, and voriconazole. Posaconazole was the most active against itraconazole-susceptible isolates. A complex pattern of cross-resistance and hypersusceptibility was seen with voriconazole and ravuconazole, suggesting marked differences in activity and mechanisms of resistance.
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Affiliation(s)
- J Mosquera
- School of Medicine, University of Manchester, Manchester M13 9PT, United Kingdom
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