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van Dijk MAM, Buil JB, Tehupeiory-Kooreman M, Broekhuizen MJ, Broens EM, Wagenaar JA, Verweij PE. Azole Resistance in Veterinary Clinical Aspergillus fumigatus Isolates in the Netherlands. Mycopathologia 2024; 189:50. [PMID: 38864903 PMCID: PMC11169034 DOI: 10.1007/s11046-024-00850-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 03/14/2024] [Indexed: 06/13/2024]
Abstract
Aspergillus fumigatus is a saprophytic fungal pathogen that causes opportunistic infections in animals and humans. Azole resistance has been reported globally in human A. fumigatus isolates, but the prevalence of resistance in isolates from animals is largely unknown. A retrospective resistance surveillance study was performed using a collection of clinical A. fumigatus isolates from various animal species collected between 2015 and 2020. Agar-based azole resistance screening of all isolates was followed by in vitro antifungal susceptibility testing and cyp51A gene sequencing of the azole-resistant isolates. Over the 5 year period 16 (11.3%) of 142 A. fumigatus culture-positive animals harbored an azole-resistant isolate. Resistant isolates were found in birds (15%; 2/13), cats (21%; 6/28), dogs (8%; 6/75) and free-ranging harbor porpoise (33%; 2/6). Azole-resistance was cyp51A mediated in all isolates: 81.3% (T-67G/)TR34/L98H, 12.5% TR46/Y121F/T289A. In one azole-resistant A. fumigatus isolate a combination of C(-70)T/F46Y/C(intron7)T/C(intron66)T/M172V/E427K single-nucleotide polymorphisms in the cyp51A gene was found. Of the animals with an azole-resistant isolate and known azole exposure status 71.4% (10/14) were azole naive. Azole resistance in A. fumigatus isolates from animals in the Netherlands is present and predominantly cyp51A TR-mediated, supporting an environmental route of resistance selection. Our data supports the need to include veterinary isolates in resistance surveillance programs. Veterinarians should consider azole resistance as a reason for therapy failure when treating aspergillosis and consider resistance testing of relevant isolates.
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Affiliation(s)
- Marloes A M van Dijk
- Faculty of Veterinary Medicine, Utrecht University, 3584 CL, Utrecht, The Netherlands.
| | - Jochem B Buil
- Department of Medical Microbiology, Radboud University Medical Center, 6525 GA, Nijmegen, The Netherlands
| | - Marlou Tehupeiory-Kooreman
- Department of Medical Microbiology, Radboud University Medical Center, 6525 GA, Nijmegen, The Netherlands
| | - Marian J Broekhuizen
- Faculty of Veterinary Medicine, Utrecht University, 3584 CL, Utrecht, The Netherlands
| | - Els M Broens
- Faculty of Veterinary Medicine, Utrecht University, 3584 CL, Utrecht, The Netherlands
| | - Jaap A Wagenaar
- Faculty of Veterinary Medicine, Utrecht University, 3584 CL, Utrecht, The Netherlands
- Wageningen Bioveterinary Research, 8221 RA, Lelystad, The Netherlands
| | - Paul E Verweij
- Department of Medical Microbiology, Radboud University Medical Center, 6525 GA, Nijmegen, The Netherlands
- Radboudumc-CWZ Center of Expertise for Mycology, 6525 GA, Nijmegen, The Netherlands
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Tan XT, Mokhtar NNB, Hii S, Amran F. Antifungal Susceptibility and Genotypic Analysis of cyp51A Mutations in Aspergillus fumigatus Isolates in Malaysia. Infect Drug Resist 2024; 17:2159-2168. [PMID: 38828376 PMCID: PMC11144424 DOI: 10.2147/idr.s452619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 04/09/2024] [Indexed: 06/05/2024] Open
Abstract
Purpose Azole resistance in Aspergillus fumigatus poses a significant challenge in the management of invasive aspergillosis. This study aimed to investigate the antifungal susceptibility and cyp51A mutation profiles of A. fumigatus isolates in Malaysia. Patients and Methods Sixty clinical A. fumigatus isolates were collected and subjected to antifungal susceptibility testing (AFST) and molecular analysis. The antifungal susceptibility testing was performed according to CLSI M38 guideline. The geometric mean (GM) minimum inhibitory concentration (MIC), MIC50/MIC90 for voriconazole, itraconazole, posaconazole, amphotericin B, and isavuconazole against A. fumigatus in non-invasive cases and invasive cases were calculated. In addition, the presence of cyp51A mutations was also identified. Results The present study revealed an overall resistance rate of 6.7% among the isolates. In non-invasive cases, isavuconazole and posaconazole demonstrated the lowest GM MIC of 0.08 µg/mL. Following them were itraconazole, voriconazole, and amphotericin B with concentrations of 0.15µg/mL, 0.16µg/mL and 0.90µg/mL, respectively. Similarly, in invasive cases, isavuconazole and posaconazole exhibited the lowest GM MIC of 0.09µg/mL. Following them were itraconazole, voriconazole, and amphotericin B with concentrations of 0.14µg/mL, 0.17µg/mL and 0.80µg/mL, respectively. Genotypic analysis revealed various cyp51A mutations, including F46Y, M172V, N248K, R34L, V244A, V244S, and E427K. However, not all mutations corresponded to antifungal resistance. Conclusion The majority of clinical Aspergillus fumigatus isolates demonstrated susceptibility to the antifungal agents tested, with isavuconazole and posaconazole demonstrating the lowest MIC values. However, cyp51A mutations were discovered without a consistent correlation to antifungal resistance, emphasising the need for additional research.
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Affiliation(s)
- Xue Ting Tan
- Bacteriology Unit, Infectious Diseases Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health Malaysia, Setia Alam, Selangor, Malaysia
| | - Nurin Nazirah Binti Mokhtar
- Bacteriology Unit, Infectious Diseases Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health Malaysia, Setia Alam, Selangor, Malaysia
| | - Shirley Yi Fen Hii
- Bacteriology Unit, Infectious Diseases Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health Malaysia, Setia Alam, Selangor, Malaysia
| | - Fairuz Amran
- Bacteriology Unit, Infectious Diseases Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health Malaysia, Setia Alam, Selangor, Malaysia
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Wang C, Miller N, Vines D, Severns PM, Momany M, Brewer MT. Azole resistance mechanisms and population structure of the human pathogen Aspergillus fumigatus on retail plant products. Appl Environ Microbiol 2024; 90:e0205623. [PMID: 38651929 PMCID: PMC11107156 DOI: 10.1128/aem.02056-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 03/30/2024] [Indexed: 04/25/2024] Open
Abstract
Aspergillus fumigatus is a ubiquitous saprotroph and human-pathogenic fungus that is life-threatening to the immunocompromised. Triazole-resistant A. fumigatus was found in patients without prior treatment with azoles, leading researchers to conclude that resistance had developed in agricultural environments where azoles are used against plant pathogens. Previous studies have documented azole-resistant A. fumigatus across agricultural environments, but few have looked at retail plant products. Our objectives were to determine if azole-resistant A. fumigatus is prevalent in retail plant products produced in the United States (U.S.), as well as to identify the resistance mechanism(s) and population genetic structure of these isolates. Five hundred twenty-five isolates were collected from retail plant products and screened for azole resistance. Twenty-four isolates collected from compost, soil, flower bulbs, and raw peanuts were pan-azole resistant. These isolates had the TR34/L98H, TR46/Y121F/T289A, G448S, and H147Y cyp51A alleles, all known to underly pan-azole resistance, as well as WT alleles, suggesting that non-cyp51A mechanisms contribute to pan-azole resistance in these isolates. Minimum spanning networks showed two lineages containing isolates with TR alleles or the F46Y/M172V/E427K allele, and discriminant analysis of principle components identified three primary clusters. This is consistent with previous studies detecting three clades of A. fumigatus and identifying pan-azole-resistant isolates with TR alleles in a single clade. We found pan-azole resistance in U.S. retail plant products, particularly compost and flower bulbs, which indicates a risk of exposure to these products for susceptible populations and that highly resistant isolates are likely distributed worldwide on these products.IMPORTANCEAspergillus fumigatus has recently been designated as a critical fungal pathogen by the World Health Organization. It is most deadly to people with compromised immune systems, and with the emergence of antifungal resistance to multiple azole drugs, this disease carries a nearly 100% fatality rate without treatment or if isolates are resistant to the drugs used to treat the disease. It is important to determine the relatedness and origins of resistant A. fumigatus isolates in the environment, including plant-based retail products, so that factors promoting the development and propagation of resistant isolates can be identified.
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Affiliation(s)
- Caroline Wang
- Fungal Biology Group, Plant Pathology Department, University of Georgia, Athens, Georgia, USA
| | - Natalie Miller
- Fungal Biology Group, Plant Pathology Department, University of Georgia, Athens, Georgia, USA
| | - Douglas Vines
- Fungal Biology Group, Plant Pathology Department, University of Georgia, Athens, Georgia, USA
| | - Paul M. Severns
- Fungal Biology Group, Plant Pathology Department, University of Georgia, Athens, Georgia, USA
| | - Michelle Momany
- Fungal Biology Group, Plant Biology Department, University of Georgia, Athens, Georgia, USA
| | - Marin T. Brewer
- Fungal Biology Group, Plant Pathology Department, University of Georgia, Athens, Georgia, USA
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M. Jimenez Madrid A, Paul RA, Rotondo F, Deblais L, Rajashekara G, Miller SA, Ivey MLL. Triazole resistance in Aspergillus fumigatus isolated from a tomato production environment exposed to propiconazole. Appl Environ Microbiol 2024; 90:e0001724. [PMID: 38534143 PMCID: PMC11022574 DOI: 10.1128/aem.00017-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 03/05/2024] [Indexed: 03/28/2024] Open
Abstract
The emergence of azole-resistant Aspergillus fumigatus (ARAf) across the world is an important public health concern. We sought to determine if propiconazole, a demethylase inhibitor (DMI) fungicide, exerted a selective pressure for ARAf in a tomato production environment following multiple exposures to the fungicide. A tomato field trial was established in 2019 and propiconazole was applied weekly until harvest. Soil, leaf, and fruit (when present) samples were collected at baseline and after each propiconazole application. A. fumigatus isolates (n, 178) were recovered and 173 were tested for susceptibility to itraconazole, posaconazole, voriconazole, and propiconazole in accordance with CLSI M38 guidelines. All the isolates were susceptible to medical triazoles and the propiconazole MIC ranged from 0.25 to 8 mg/L. A linear regression model was fitted that showed no longitudinal increment in the log2-fold azole MIC of the isolates collected after each propiconazole exposure compared to the baseline isolates. AsperGenius real-time multiplex assay ruled out TR34/L98H and TR46/Y121F/T289A cyp51A resistance markers in these isolates. Sequencing of a subset of isolates (n, 46) demonstrated widespread presence of F46Y/M172V/E427K and F46Y/M172V/N248T/D255E/E427K cyp51A mutations previously associated with reduced susceptibility to triazoles. IMPORTANCE The agricultural use of azole fungicides to control plant diseases has been implicated as a major contributor to ARAf infections in humans. Our study did not reveal imposition of selection pressure for ARAf in a vegetable production system. However, more surveillance studies for ARAf in food crop production and other environments are warranted in understanding this public and One Health issue.
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Affiliation(s)
- Alejandra M. Jimenez Madrid
- Department of Plant Pathology, The Ohio State University College of Food, Agricultural and Environmental Sciences-Wooster, Wooster, Ohio, USA
| | - Raees A. Paul
- Department of Plant Pathology, The Ohio State University College of Food, Agricultural and Environmental Sciences-Wooster, Wooster, Ohio, USA
| | - Francesca Rotondo
- Department of Plant Pathology, The Ohio State University College of Food, Agricultural and Environmental Sciences-Wooster, Wooster, Ohio, USA
| | - Loic Deblais
- Department of Animal Sciences, Center for Food Animal Health, The Ohio State University College of Food, Agricultural and Environmental Sciences-Wooster, Wooster, Ohio, USA
| | - Gireesh Rajashekara
- Department of Animal Sciences, Center for Food Animal Health, The Ohio State University College of Food, Agricultural and Environmental Sciences-Wooster, Wooster, Ohio, USA
| | - Sally A. Miller
- Department of Plant Pathology, The Ohio State University College of Food, Agricultural and Environmental Sciences-Wooster, Wooster, Ohio, USA
| | - Melanie L. Lewis Ivey
- Department of Plant Pathology, The Ohio State University College of Food, Agricultural and Environmental Sciences-Wooster, Wooster, Ohio, USA
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da Fonseca LMM, Braga VF, Tonani L, Grizante Barião PH, Nascimento E, Martinez R, von Zeska Kress MR. Surveillance of Amphotericin B and Azole Resistance in Aspergillus Isolated from Patients in a Tertiary Teaching Hospital. J Fungi (Basel) 2023; 9:1070. [PMID: 37998875 PMCID: PMC10672583 DOI: 10.3390/jof9111070] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 10/08/2023] [Accepted: 10/09/2023] [Indexed: 11/25/2023] Open
Abstract
The genus Aspergillus harbors human infection-causing pathogens and is involved in the complex one-health challenge of antifungal resistance. Here, a 6-year retrospective study was conducted with Aspergillus spp. isolated from patients with invasive, chronic, and clinically suspected aspergillosis in a tertiary teaching hospital. A total of 64 Aspergillus spp. clinical isolates were investigated regarding molecular identification, biofilm, virulence in Galleria mellonella, antifungal susceptibility, and resistance to amphotericin B and azoles. Aspergillus section Fumigati (A. fumigatus sensu stricto, 62.5%) and section Flavi (A. flavus, 20.3%; A. parasiticus, 14%; and A. tamarii, 3.1%) have been identified. Aspergillus section Flavi clinical isolates were more virulent than section Fumigati clinical isolates. Furthermore, scant evidence supports a link between biofilm formation and virulence. The susceptibility of the Aspergillus spp. clinical isolates to itraconazole, posaconazole, voriconazole, and amphotericin B was evaluated. Most Aspergillus spp. clinical isolates (67.2%) had an AMB MIC value equal to or above 2 µg/mL, warning of a higher probability of therapeutic failure in the region under study. In general, the triazoles presented MIC values above the epidemiological cutoff value. The high triazole MIC values of A. fumigatus s.s. clinical isolates were investigated by sequencing the promoter region and cyp51A locus. The Cyp51A amino acid substitutions F46Y, M172V, N248T, N248K, D255E, and E427K were globally detected in 47.5% of A. fumigatus s.s. clinical isolates, and most of them are associated with high triazole MICs. Even so, the findings support voriconazole or itraconazole as the first therapeutic choice for treating Aspergillus infections. This study emphasizes the significance of continued surveillance of Aspergillus spp. infections to help overcome the gap in knowledge of the global fungal burden of infections and antifungal resistance, supporting public health initiatives.
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Affiliation(s)
- Lívia Maria Maciel da Fonseca
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão, Universidade de Sao Paulo, Ribeirao Preto 14040-903, Brazil; (L.M.M.d.F.); (L.T.); (P.H.G.B.)
| | - Vanessa Fávaro Braga
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão, Universidade de Sao Paulo, Ribeirao Preto 14040-903, Brazil; (L.M.M.d.F.); (L.T.); (P.H.G.B.)
| | - Ludmilla Tonani
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão, Universidade de Sao Paulo, Ribeirao Preto 14040-903, Brazil; (L.M.M.d.F.); (L.T.); (P.H.G.B.)
| | - Patrícia Helena Grizante Barião
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão, Universidade de Sao Paulo, Ribeirao Preto 14040-903, Brazil; (L.M.M.d.F.); (L.T.); (P.H.G.B.)
| | - Erika Nascimento
- Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirao Preto 14040-900, Brazil; (E.N.); (R.M.)
| | - Roberto Martinez
- Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirao Preto 14040-900, Brazil; (E.N.); (R.M.)
| | - Marcia Regina von Zeska Kress
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão, Universidade de Sao Paulo, Ribeirao Preto 14040-903, Brazil; (L.M.M.d.F.); (L.T.); (P.H.G.B.)
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Bosetti D, Neofytos D. Invasive Aspergillosis and the Impact of Azole-resistance. CURRENT FUNGAL INFECTION REPORTS 2023; 17:1-10. [PMID: 37360857 PMCID: PMC10024029 DOI: 10.1007/s12281-023-00459-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/04/2023] [Indexed: 06/28/2023]
Abstract
Purpose of Review IA (invasive aspergillosis) caused by azole-resistant strains has been associated with higher clinical burden and mortality rates. We review the current epidemiology, diagnostic, and therapeutic strategies of this clinical entity, with a special focus on patients with hematologic malignancies. Recent Findings There is an increase of azole resistance in Aspergillus spp. worldwide, probably due to environmental pressure and the increase of long-term azole prophylaxis and treatment in immunocompromised patients (e.g., in hematopoietic stem cell transplant recipients). The therapeutic approaches are challenging, due to multidrug-resistant strains, drug interactions, side effects, and patient-related conditions. Summary Rapid recognition of resistant Aspergillus spp. strains is fundamental to initiate an appropriate antifungal regimen, above all for allogeneic hematopoietic cell transplantation recipients. Clearly, more studies are needed in order to better understand the resistance mechanisms and optimize the diagnostic methods to identify Aspergillus spp. resistance to the existing antifungal agents/classes. More data on the susceptibility profile of Aspergillus spp. against the new classes of antifungal agents may allow for better treatment options and improved clinical outcomes in the coming years. In the meantime, continuous surveillance studies to monitor the prevalence of environmental and patient prevalence of azole resistance among Aspergillus spp. is absolutely crucial.
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Affiliation(s)
- Davide Bosetti
- Division of Infectious Diseases, Geneva University Hospitals, Rue Gabrielle-Perret-Gentil 4, Geneva, Switzerland
| | - Dionysios Neofytos
- Division of Infectious Diseases, Geneva University Hospitals, Rue Gabrielle-Perret-Gentil 4, Geneva, Switzerland
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Pulmonary Aspergillosis in Humboldt Penguins—Susceptibility Patterns and Molecular Epidemiology of Clinical and Environmental Aspergillus fumigatus Isolates from a Belgian Zoo, 2017–2022. Antibiotics (Basel) 2023; 12:antibiotics12030584. [PMID: 36978451 PMCID: PMC10044460 DOI: 10.3390/antibiotics12030584] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/10/2023] [Accepted: 03/13/2023] [Indexed: 03/17/2023] Open
Abstract
Aspergillus fumigatus is the main causative agent of avian aspergillosis and results in significant health problems in birds, especially those living in captivity. The fungal contamination by A. fumigatus in the environment of Humboldt penguins (Spheniscus humboldti), located in a Belgian zoo, was assessed through the analysis of air, water, sand and nest samples during four non-consecutive days in 2021–2022. From these samples, potential azole-resistant A. fumigatus (ARAF) isolates were detected using a selective culture medium. A total of 28 veterinary isolates obtained after necropsy of Humboldt penguins and other avian species from the zoo were also included. All veterinary and suspected ARAF isolates from the environment were characterized for their azole-resistance profile by broth microdilution. Isolates displaying phenotypic resistance against at least one medical azole were systematically screened for mutations in the cyp51A gene. A total of 14 (13.6%) ARAF isolates were identified from the environment (n = 8) and from Humboldt penguins (n = 6). The TR34/L98H mutation was observed in all resistant environmental strains, and in two resistant veterinary strains. To the best of our knowledge, this is the first description of this mutation in A. fumigatus isolates from Humboldt penguins. During the period 2017–2022, pulmonary aspergillosis was confirmed in 51 necropsied penguins, which reflects a death rate due to aspergillosis of 68.0%, mostly affecting adults. Microsatellite polymorphism analysis revealed a high level of diversity among environmental and veterinary A. fumigatus isolates. However, a cluster was observed between one veterinary isolate and six environmental strains, all resistant to medical azoles. In conclusion, the environment of the Humboldt penguins is a potential contamination source of ARAF, making their management even more complex.
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Sen P, Gupta L, Vijay M, Vermani Sarin M, Shankar J, Hameed S, Vijayaraghavan P. 4-Allyl-2-methoxyphenol modulates the expression of genes involved in efflux pump, biofilm formation and sterol biosynthesis in azole resistant Aspergillus fumigatus. Front Cell Infect Microbiol 2023; 13:1103957. [PMID: 36816579 PMCID: PMC9929553 DOI: 10.3389/fcimb.2023.1103957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 01/06/2023] [Indexed: 02/04/2023] Open
Abstract
Introduction Antifungal therapy for aspergillosis is becoming problematic because of the toxicity of currently available drugs, biofilm formation on host surface, and increasing prevalence of azole resistance in Aspergillus fumigatus. Plants are rich source of bioactive molecules and antimicrobial activity of aromatic bioactive compounds draws attention because of its promising biological properties. The present study elucidated the antibiofilm activity of 4-allyl-2-methoxyphenol (eugenol) against azole-resistant environmental A. fumigatus isolates. Methods Soil samples were collected from agricultural fields across India; azole-resistant A. fumigatus (ARAF) were isolated followed by their molecular identification. Antibiofilm activity of eugenol was calculated via tetrazolium based-MTT assay. The expression of the multidrug efflux pumps genes MDR1, MDR4, transporters of the MFS gene, erg11A gene encoding 14α demethylase, and transcription regulatory genes, MedA, SomA and SrbA, involved in biofilm formation of A. fumigatus were calculated by quantitative real time PCR. Results Out of 89 A. fumigatus isolates, 10 were identified as azole resistant. Eugenol exhibited antibiofilm activity against ARAF isolates, ranging from 312 to 500 µg/mL. Confocal laser scanning microscopy analysis revealed absence of extracellular matrix of ARAF biofilm after eugenol treatment. The gene expression indicated significantly low expression of efflux pumps genes MDR1, MDR4, erg11A and MedA in eugenol treated ARAF isolates when compared with untreated isolates. Conclusions Our results demonstrate that eugenol effects the expression of efflux pump and biofilm associated genes as well as inhibits biofilm formation in azole resistant isolates of A. fumigatus.
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Affiliation(s)
- Pooja Sen
- Anti-mycotic Drug Susceptibility Laboratory, Amity Institute of Biotechnology, Amity University Uttar Pradesh, Noida, India
| | - Lovely Gupta
- Anti-mycotic Drug Susceptibility Laboratory, Amity Institute of Biotechnology, Amity University Uttar Pradesh, Noida, India
| | - Mukund Vijay
- Anti-mycotic Drug Susceptibility Laboratory, Amity Institute of Biotechnology, Amity University Uttar Pradesh, Noida, India
| | - Maansi Vermani Sarin
- Anti-mycotic Drug Susceptibility Laboratory, Amity Institute of Biotechnology, Amity University Uttar Pradesh, Noida, India
| | - Jata Shankar
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Solan, India
| | - Saif Hameed
- Amity Institute of Biotechnology, Amity University Haryana, Gurugram (Manesar), India
| | - Pooja Vijayaraghavan
- Anti-mycotic Drug Susceptibility Laboratory, Amity Institute of Biotechnology, Amity University Uttar Pradesh, Noida, India,*Correspondence: Pooja Vijayaraghavan,
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Zhao S, Martin-Vicente A, Colabardini AC, Pereira Silva L, Rinker DC, Fortwendel JR, Goldman GH, Gibbons JG. Genomic and Molecular Identification of Genes Contributing to the Caspofungin Paradoxical Effect in Aspergillus fumigatus. Microbiol Spectr 2022; 10:e0051922. [PMID: 36094204 PMCID: PMC9603777 DOI: 10.1128/spectrum.00519-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 08/17/2022] [Indexed: 11/25/2022] Open
Abstract
Aspergillus fumigatus is a deadly opportunistic fungal pathogen responsible for ~100,000 annual deaths. Azoles are the first line antifungal agent used against A. fumigatus, but azole resistance has rapidly evolved making treatment challenging. Caspofungin is an important second-line therapy against invasive pulmonary aspergillosis, a severe A. fumigatus infection. Caspofungin functions by inhibiting β-1,3-glucan synthesis, a primary and essential component of the fungal cell wall. A phenomenon termed the caspofungin paradoxical effect (CPE) has been observed in several fungal species where at higher concentrations of caspofungin, chitin replaces β-1,3-glucan, morphology returns to normal, and growth rate increases. CPE appears to occur in vivo, and it is therefore clinically important to better understand the genetic contributors to CPE. We applied genomewide association (GWA) analysis and molecular genetics to identify and validate candidate genes involved in CPE. We quantified CPE across 67 clinical isolates and conducted three independent GWA analyses to identify genetic variants associated with CPE. We identified 48 single nucleotide polymorphisms (SNPs) associated with CPE. We used a CRISPR/Cas9 approach to generate gene deletion mutants for seven genes harboring candidate SNPs. Two null mutants, ΔAfu3g13230 and ΔAfu4g07080 (dscP), resulted in reduced basal growth rate and a loss of CPE. We further characterized the dscP phosphatase-null mutant and observed a significant reduction in conidia production and extremely high sensitivity to caspofungin at both low and high concentrations. Collectively, our work reveals the contribution of Afu3g13230 and dscP in CPE and sheds new light on the complex genetic interactions governing this phenotype. IMPORTANCE This is one of the first studies to apply genomewide association (GWA) analysis to identify genes involved in an Aspergillus fumigatus phenotype. A. fumigatus is an opportunistic fungal pathogen that causes hundreds of thousands of infections and ~100,000 deaths each year, and antifungal resistance has rapidly evolved in this species. A phenomenon called the caspofungin paradoxical effect (CPE) occurs in some isolates, where high concentrations of the drug lead to increased growth rate. There is clinical relevance in understanding the genetic basis of this phenotype, since caspofungin concentrations could lead to unintended adverse clinical outcomes in certain cases. Using GWA analysis, we identified several interesting candidate polymorphisms and genes and then generated gene deletion mutants to determine whether these genes were important for CPE. Two of these mutant strains (ΔAfu3g13230 and ΔAfu4g07080/ΔdscP) displayed a loss of the CPE. This study sheds light on the genes involved in clinically important phenotype CPE.
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Affiliation(s)
- Shu Zhao
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts, USA
- Department of Food Science, University of Massachusetts, Amherst, Massachusetts, USA
| | - Adela Martin-Vicente
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Ana Cristina Colabardini
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Lilian Pereira Silva
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - David C. Rinker
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Jarrod R. Fortwendel
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Gustavo Henrique Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - John G. Gibbons
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts, USA
- Department of Food Science, University of Massachusetts, Amherst, Massachusetts, USA
- Organismic and Evolutionary Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts, USA
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10
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Hsu TH, Huang PY, Fan YC, Sun PL. Azole Resistance and cyp51A Mutation of Aspergillus fumigatus in a Tertiary Referral Hospital in Taiwan. J Fungi (Basel) 2022; 8:jof8090908. [PMID: 36135633 PMCID: PMC9504549 DOI: 10.3390/jof8090908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 08/20/2022] [Accepted: 08/24/2022] [Indexed: 01/30/2023] Open
Abstract
Azole resistance in Aspergillus fumigatus has increasingly been reported worldwide. Its major mechanism of resistance is mediated by mutations in cyp51A. The objective of this study was to test the antifungal susceptibilities of A. fumigatus isolates from Chang Gung Memorial Hospital (CGMH), the largest tertiary referral hospital in Taiwan, and to investigate cyp51A mutations in azole-resistant strains. A. fumigatus isolates preserved in the Research Laboratory of Medical Mycology of CGMH from 2015 to 2021 were used. Antifungal susceptibility testing was performed using the YeastOneTM method. Isolates with high minimal inhibitory concentrations (MICs) against antifungals were further tested using the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method. Mutations in the cyp51A in azole-resistant strains were detected by Sanger sequencing. The overall prevalence of azole-resistant isolates was 1.77% (two out of 113 isolates). The two azole-resistant strains had tandem repeats (TR) in the promoter region and mutations in the cyp51A gene (TR34/L98H and TR34/L98H/S297T/F495I). One strain showed intermediate susceptibility to voriconazole, and its Cyp51A protein had five amino acid substitutions (F46Y/M172V/N248T/D255E/E427K). TR34/L98H and TR34/L98H/S297T/F495I are the most prevalent cyp51A mutations in Taiwan, mediating azole resistance based on current publications and our results. YeastOneTM was validated as a rapid tool for the antifungal susceptibility test; however, further confirmation by CLSI should be considered when MIC values of voriconazole, posaconazole, and amphotericin B are close to the clinical breakpoints or ecological cutoff values.
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Affiliation(s)
- Tsun-Hao Hsu
- Department of Dermatology, Chang Gung Memorial Hospital, Linkou Branch, Taoyuan 333423, Taiwan
| | - Po-Yen Huang
- Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou Branch, Taoyuan 333423, Taiwan
- College of Medicine, Chang Gung University, Taoyuan 333323, Taiwan
| | - Yun-Chen Fan
- Research Laboratory of Medical Mycology, Chang Gung Memorial Hospital, Linkou Branch, Taoyuan 333423, Taiwan
| | - Pei-Lun Sun
- Department of Dermatology, Chang Gung Memorial Hospital, Linkou Branch, Taoyuan 333423, Taiwan
- College of Medicine, Chang Gung University, Taoyuan 333323, Taiwan
- Research Laboratory of Medical Mycology, Chang Gung Memorial Hospital, Linkou Branch, Taoyuan 333423, Taiwan
- Correspondence: ; Tel.: +886-3-328-1200 (ext. 8778)
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11
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Amona MF, Oladele RO, Resendiz-Sharpe A, Denning DW, Kosmidis C, Lagrou K, Zhong H, Han L. Triazole resistance in Aspergillus fumigatus isolates in Africa: a systematic review. Med Mycol 2022; 60:6652216. [PMID: 35906879 DOI: 10.1093/mmy/myac059] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 07/18/2022] [Accepted: 07/27/2022] [Indexed: 11/13/2022] Open
Abstract
Emergence of triazole resistance has been observed in Aspergillus fumigatus over the past decade including in Africa. This review summarizes the current published data on the epidemiology and reported mechanisms of triazole-resistant Aspergillus fumigatus (TRAF) in both environmental and clinical isolates from Africa. Searches on databases Medline, PubMed, HINARI, Science Direct, Scopus and Google Scholar on triazole resistance published between 2000 and 2021 from Africa were performed. Isolate source, antifungal susceptibility using internationally recognized methods, cyp51A mechanism of resistance and genotype were collected. Eleven published African studies were found that fitted the search criteria; these were subsequently analyzed. In total this constituted of 1686 environmental and 46 clinical samples. A TRAF prevalence of 17.1% (66/387) and 1,3% (5/387) was found in respectively environmental and clinical settings in African studies. Resistant to itraconazole, voriconazole, and posaconazole was documented. Most of the triazole-resistant isolates (30/71, 42.25%) were found to possess the TR34/L98H mutation in the cyp51A-gene; fewer with TR46/Y121F/T289A (n = 8), F46Y/M172V/E427K (n = 1), G54E (n = 13), and M172V (n = 1) mutations. African isolates with the TR34/L98H, TR46/Y121F/T289A and the G54E mutations were closely related and could be grouped in one of two clusters (cluster-B), whereas the cyp51A-M172V mutation clustered with most cyp51A- WT strains (cluster-A). A single case from Kenya shows that TR34/L98H from environmental and clinical isolates are closely related. Our findings highlight that triazole resistance in environmental and clinical A. fumigatus is a cause for concern in a number of African countries. There is need for epidemiological surveillance to determine the true burden of the problem in Africa.
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Affiliation(s)
- Modeste Fructueux Amona
- Faculty of Health Sciences, Marien Ngouabi University, Brazzaville, Republic of Congo.,Research Center and Study of Infectious and Tropical Pathologies, Oyo, Republic of Congo
| | - Rita Okeoghene Oladele
- Department of Medical Microbiology and Parasitology, College of Medicine, University of Lagos, Lagos, Nigeria.,Department of Medical Microbiology and Parasitology, Lagos University Teaching Hospital, Idi-Araba, Lagos, Nigeria
| | - Agustin Resendiz-Sharpe
- Department of Microbiology, Laboratory of Clinical Bacteriology and Mycology, Immunology and Transplantation, KU Leuven, Leuven, Belgium.,Department of Imaging and Pathology, Biomedical MRI, KU Leuven, Leuven, Belgium
| | - David W Denning
- Manchester Fungal Infection Group, the University of Manchester and Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Chris Kosmidis
- National Aspergillosis Centre, Manchester University Foundation Trust, UK, and Manchester Academic Health Science Centre, the University of Manchester, Manchester, UK
| | - Katrien Lagrou
- Department of Microbiology, Laboratory of Clinical Bacteriology and Mycology, Immunology and Transplantation, KU Leuven, Leuven, Belgium.,Department of Laboratory Medicine and National Reference Center for Mycosis, University Hospitals Leuven, Leuven, Belgium
| | - Hanying Zhong
- Department for Disinfection and Infection Control, Chinese PLA Center for Disease Control and Prevention, Beijing, China
| | - Li Han
- Department for Disinfection and Infection Control, Chinese PLA Center for Disease Control and Prevention, Beijing, China
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12
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Deletion of cox7c Results in Pan-Azole Resistance in Aspergillus fumigatus. Antimicrob Agents Chemother 2022; 66:e0015122. [PMID: 35647650 PMCID: PMC9211413 DOI: 10.1128/aac.00151-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Aspergillus fumigatus, the most prevalent resistance to azoles results from mutational modifications of the azole target protein Cyp51A, but there are non-cyp51A mutants resistant to azoles, and the mechanisms underlying the resistance of these strains remain to be explored. Here, we identified a novel cytochrome c oxidase, cox7c (W56*), nonsense mutation in the laboratory and found that it caused reduced colony growth and resistance to multiantifungal agents. Meanwhile, we revealed that cold storage is responsible for increased tolerance of conidia to itraconazole (ITC) stress, which further advances azole-resistant mutations (cryopreservation→ITC tolerance→azole resistance). The deletion or mutation of cox7c results explicitly in resistance to antifungal-targeting enzymes, including triazoles, polyenes, and allylamines, required for ergosterol synthesis, or resistance to fungal ergosterol. A high-performance liquid chromatography (HPLC) assay showed that the cox7c knockout strain decreased intracellular itraconazole concentration. In addition, the lack of Cox7c resulted in the accumulation of intracellular heme B. We validated that an endogenous increase in, or the exogenous addition of, heme B was capable of eliciting azole resistance, which was in good accordance with the phenotypic resistance analysis of cox7c mutants. Furthermore, RNA sequencing verified the elevated transcriptional expression levels of multidrug transport genes. Additionally, lower itraconazole-induced reactive oxygen species generation in mycelia of a cox7c-deletion strain suggested that this reduction may, in part, contribute to drug resistance. These findings increase our understanding of how A. fumigatus’s direct responses to azoles promote fungal survival in the environment and address genetic mutations that arise from patients or environments.
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13
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Zhou D, Wang R, Li X, Peng B, Yang G, Zhang KQ, Zhang Y, Xu J. Genetic Diversity and Azole Resistance Among Natural Aspergillus fumigatus Populations in Yunnan, China. MICROBIAL ECOLOGY 2022; 83:869-885. [PMID: 34279697 DOI: 10.1007/s00248-021-01804-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
The emergence and spread of azole resistance alleles in clinical and environmental isolates of Aspergillus fumigatus is a global human health concern and endangers the "One Health" approach in our fight against antifungal resistance (AFR) in this pathogen. A major challenge to combat AFR in A. fumigatus is the massive aerial dispersal ability of its asexual spores. Our recent fine-scale survey of greenhouse populations of A. fumigatus near Kunming, Yunnan, China, suggested that the use of azole fungicides for plant protection was likely a major driver of the high-frequency azole-resistant A. fumigatus (ARAF) in greenhouses. Here, we investigated the potential spread of those ARAF and the structure of geographic populations of A. fumigatus by analyzing 452 isolates from 19 geographic locations across Yunnan. We found lower frequencies of ARAF in these outdoor populations than those in greenhouses near Kunming, but there were abundant new alleles and new genotypes, including those associated with azole resistance, consistent with multiple independent origins of ARAF across Yunnan. Interestingly, among the four ecological niches, the sediments of a large lake near Kunming were found to have the highest frequency of ARAF (~ 43%). While most genetic variations were observed within the 19 local populations, statistically significant genetic differentiations were found between many subpopulations within Yunnan. Furthermore, similar to greenhouse populations, these outdoor populations of A. fumigatus in Yunnan were significantly different from those in other parts of the world. Our results call for increased attention to local and regional studies of this fungal pathogen to help develop targeted control strategies against ARAF.
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Affiliation(s)
- Duanyong Zhou
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, and Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
- College of Life Science, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
- School of Biology and Chemistry, Xingyi Normal University for Nationalities, Xingyi, 562400, Guizhou, People's Republic of China
| | - Ruirui Wang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, and Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
- College of Life Science, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
| | - Xiao Li
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, and Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
- College of Life Science, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
| | - Bin Peng
- College of Life Science, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
| | - Guangzhu Yang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, and Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
- College of Life Science, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
| | - Ke-Qin Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, and Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
| | - Ying Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, and Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China.
| | - Jianping Xu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, and Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China.
- Department of Biology, McMaster University, Hamilton, Ontario, L8S 4K1, Canada.
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14
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Kirchhoff L, Braun L, Schmidt D, Dittmer S, Dedy J, Herbstreit F, Stauf R, Steckel NK, Buer J, Rath PM, Steinmann J, Verhasselt HL. COVID-19-associated pulmonary aspergillosis in ICU patients in a German reference centre: phenotypic and molecular characterization of Aspergillus fumigatus isolates. Mycoses 2022; 65:458-465. [PMID: 35138651 PMCID: PMC9115305 DOI: 10.1111/myc.13430] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/05/2022] [Accepted: 02/07/2022] [Indexed: 01/08/2023]
Abstract
Background COVID‐19‐associated invasive pulmonary aspergillosis (CAPA) is associated with increased mortality. Cases of CAPA caused by azole‐resistant Aspergillus fumigatus strains have been reported. Objectives To analyse the twelve‐month CAPA prevalence in a German tertiary care hospital and to characterise clinical A. fumigatus isolates from two German hospitals by antifungal susceptibility testing and microsatellite genotyping. Patients/Methods. Retrospective observational study in critically ill adults from intensive care units with COVID‐19 from 17 February 2020 until 16 February 2021 and collection of A. fumigatus isolates from two German centres. EUCAST broth microdilution for four azole compounds and microsatellite PCR with nine markers were performed for each collected isolate (N = 27) and additional for three non‐COVID A. fumigatus isolates. Results welve‐month CAPA prevalence was 7.2% (30/414), and the rate of azole‐resistant A. fumigatus isolates from patients with CAPA was 3.7% with detection of one TR34/L98H mutation. The microsatellite analysis revealed no major clustering of the isolates. Sequential isolates mainly showed the same genotype over time. Conclusions Our findings demonstrate similar CAPA prevalence to other reports and a low azole‐resistance rate. Genotyping of A. fumigatus showed polyclonal distribution except for sequential isolates.
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Affiliation(s)
- Lisa Kirchhoff
- Institute of Medical Microbiology, University Hospital Essen, ECMM Centre of Excellence in Mycology, Germany
| | - Lukas Braun
- Institute of Medical Microbiology, University Hospital Essen, ECMM Centre of Excellence in Mycology, Germany
| | - Dirk Schmidt
- Institute of Medical Microbiology, University Hospital Essen, ECMM Centre of Excellence in Mycology, Germany
| | - Silke Dittmer
- Institute of Medical Microbiology, University Hospital Essen, ECMM Centre of Excellence in Mycology, Germany
| | - Jutta Dedy
- University Hospital Essen, Pharmacy, Germany
| | - Frank Herbstreit
- Department of Anaesthesiology and Intensive Care Medicine, University Hospital Essen, Germany
| | - Raphael Stauf
- Institute of Hospital Hygiene and Clinical Microbiology, Klinikum Dortmund gGmbH, Dortmund, Germany
| | - Nina Kristin Steckel
- Department of Bone Marrow Transplantation, West German Cancer Centre, University Hospital Essen, Essen, Germany
| | - Jan Buer
- Institute of Medical Microbiology, University Hospital Essen, ECMM Centre of Excellence in Mycology, Germany
| | - Peter-Michael Rath
- Institute of Medical Microbiology, University Hospital Essen, ECMM Centre of Excellence in Mycology, Germany
| | - Joerg Steinmann
- Institute of Medical Microbiology, University Hospital Essen, ECMM Centre of Excellence in Mycology, Germany.,Institute of Clinical Hygiene, Medical Microbiology and Infectiology, General Hospital Nürnberg, Paracelsus Medical University, Nuremberg, Germany
| | - Hedda Luise Verhasselt
- Institute of Medical Microbiology, University Hospital Essen, ECMM Centre of Excellence in Mycology, Germany
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15
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Bader O. Phylogenetic Distribution of csp1 Types in Aspergillus fumigatus and Their Correlates to Azole Antifungal Drug Resistance. Microbiol Spectr 2021; 9:e0121421. [PMID: 34787484 PMCID: PMC8597649 DOI: 10.1128/spectrum.01214-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 09/22/2021] [Indexed: 11/20/2022] Open
Abstract
In Aspergillus fumigatus, the repetitive region of the csp1 gene is one of the most frequently used loci for intraspecies typing of this human pathogenic mold. Using PCR amplification and Sanger sequencing of only a single marker, csp1 typing is readily available to most laboratories and highly reproducible. Here, I evaluate the usefulness of the csp1 marker for resistance detection and epidemiologic stratification among A. fumigatus isolates. After resolving nomenclature conflicts from published studies and adding novel csp1 types, the number of known types now adds up to 38. Their distribution mostly correlates with A. fumigatus population structure, and they are also meaningful for narrowly defined cases of azole resistance phenotypes. Isolates carrying the pandemic resistance allele TR34/L98H show signs of interclade crossing of strains with t02 or t04A, into the t11 clade. Furthermore, absolute differences in voriconazole MIC values between t02/t04B versus t11 TR34/L98H isolates indicate that the genetic background of resistance mutations may have a pivotal role in cross-resistance phenotypes and, thus, clinical outcome and environmental selection. Despite the general genetic similarity of isolates with identical csp1 types, outcrossing into other clades is also observed. The csp1 type alone, therefore, does not sufficiently discriminate genetic clades to be used as the sole marker in epidemiologic studies. IMPORTANCE Aspergillus fumigatus is a ubiquitously distributed saprophytic mold and a leading cause of invasive aspergillosis in human hosts. Pandemic azole-resistant strains have emerged on a global scale, which are thought to be propagated through use of azole-based fungicides in agriculture. To perform epidemiologic studies, genetic typing of large cohorts is key. Here, I evaluate the usefulness of the frequently used csp1 marker for resistance detection and epidemiologic stratification among A. fumigatus isolates. The phylogenetic distribution of csp1 types mostly correlates with A. fumigatus population structure and is also meaningful for narrowly defined cases of azole resistance phenotypes. Nevertheless, outcrossing of csp1 into other clades is also observed. The csp1 type alone, therefore, does not sufficiently discriminate genetic clades and should not be used as the sole marker in epidemiologic studies.
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Affiliation(s)
- Oliver Bader
- Institute for Medical Microbiology and Virology, University Medical Center Göttingen, Göttingen, Germany
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16
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Rivelli Zea SM, Toyotome T. Azole-resistant Aspergillus fumigatus as an emerging worldwide pathogen. Microbiol Immunol 2021; 66:135-144. [PMID: 34870333 DOI: 10.1111/1348-0421.12957] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 11/30/2021] [Accepted: 12/01/2021] [Indexed: 12/19/2022]
Abstract
Aspergillus fumigatus, a ubiquitous pathogen, causes aspergillosis in humans, especially in immunodeficient patients. Azoles are frontline antifungal drugs for treating aspergillosis. The recent global emergence of azole resistance in A. fumigatus has become a serious problem worldwide. It has arisen through two routes: long-term azole medical therapy, called the patient route, and the use of azole fungicides in its habitats especially for agricultural activities, called the environmental route. Resistant strains developed through the latter route show cross-resistance to medical azoles because of the identical molecular target Cyp51A between azole compounds used for medical treatment and agricultural disease control. In azole-resistant strains arising through the environmental route, A. fumigatus is observed frequently possessing mutations in the cyp51A gene linked to tandem repeats in the promoter region such as TR34 /L98H and TR46 /Y121F/T289A. Results of microsatellite genotyping analyses of resistant A. fumigatus strains have suggested a transboundary spread of this microorganism in many countries. Diverse actors are involved in the global highway of transmission. Therefore, the matter must be addressed as a "One Health" issue. This review presents a background of azole resistance in A. fumigatus and introduces newly discovered difficulties generated as this pathogen spreads worldwide. This article is protected by copyright. All rights reserved.
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Affiliation(s)
| | - Takahito Toyotome
- Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine.,Diagnostic Center for Animal Health and Food Safety, Obihiro University of Agriculture and Veterinary Medicine.,Medical Mycology Research Center, Chiba University
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17
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In Vivo Efficacy of Voriconazole in a Galleria mellonella Model of Invasive Infection Due to Azole-Susceptible or Resistant Aspergillus fumigatus Isolates. J Fungi (Basel) 2021; 7:jof7121012. [PMID: 34946994 PMCID: PMC8708373 DOI: 10.3390/jof7121012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/15/2021] [Accepted: 11/21/2021] [Indexed: 02/05/2023] Open
Abstract
Aspergillus fumigatus is an environmental filamentous fungus responsible for life-threatening infections in humans and animals. Azoles are the first-line treatment for aspergillosis, but in recent years, the emergence of azole resistance in A. fumigatus has changed treatment recommendations. The objective of this study was to evaluate the efficacy of voriconazole (VRZ) in a Galleria mellonella model of invasive infection due to azole-susceptible or azole-resistant A. fumigatus isolates. We also sought to describe the pharmacokinetics of VRZ in the G. mellonella model. G. mellonella larvae were infected with conidial suspensions of azole-susceptible and azole-resistant isolates of A. fumigatus. Mortality curves were used to calculate the lethal dose. Assessment of the efficacy of VRZ or amphotericin B (AMB) treatment was based on mortality in the lethal model and histopathologic lesions. The pharmacokinetics of VRZ were determined in larval hemolymph. Invasive fungal infection was obtained after conidial inoculation. A dose-dependent reduction in mortality was observed after antifungal treatment with AMB and VRZ. VRZ was more effective at treating larvae inoculated with azole-susceptible A. fumigatus isolates than larvae inoculated with azole-resistant isolates. The concentration of VRZ was maximal at the beginning of treatment and gradually decreased in the hemolymph to reach a Cmin (24 h) between 0.11 and 11.30 mg/L, depending on the dose. In conclusion, G. mellonella is a suitable model for testing the efficacy of antifungal agents against A. fumigatus.
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18
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Castanheira M, Collingsworth TD, Davis AP, Deshpande LM, Pfaller MA. Isavuconazole nonwildtype Aspergillus fumigatus isolates from a global surveillance study display alterations in multiple genes involved in the ergosterol biosynthesis pathway not previously associated with resistance to other azoles. Mycoses 2021; 64:1279-1290. [PMID: 33705591 DOI: 10.1111/myc.13267] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 03/05/2021] [Accepted: 03/08/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVES We evaluated 35 azole nonwildtype Aspergillus fumigatus isolates that were collected during 2017-2018 using whole genome sequencing (WGS) to detect alterations in the genes involved in the ergosterol biosynthesis pathway as well as other genes associated with azole resistance. METHODS Among 297 A fumigatus isolates collected worldwide, 36 isolates displayed nonwildtype MIC values to isavuconazole, itraconazole, or voriconazole when tested by the CLSI reference broth microdilution method. Isolates were submitted to WGS and results were compared to 2 azolewildtype isolates. RESULTS Among the 35 sequenced isolates (1 failed to produce quality sequences), 29 were nonwildtype to isavuconazole, 16 were nonwildtype to itraconazole, and 9 were nonwildtype to voriconazole (CLSI M59Ed2 criteria). A total of 9 isolates carried Cyp51A TR34/L98H alterations (8 from Italy and 1 from Belgium) and had nonwildtype MIC values for ≥2 azoles. A Cyp51B Q42L mutation was detected in 3 isolates, 1 nonwildtype voriconazole and 2 nonwildtype isavuconazole isolates. Three isolates harboured multiple mutations in Cyp51A (F46Y, M172V, E427K ± N248T, and D255E), including 1 isolate with the Cyp51B Q42L mutation. Mutations causing frameshifts, early termination, and duplications were observed among several genes and were more prevalent in isavuconazole nonwildtype isolates (66.7%) than in the isolates that were nonwildtype to 1 or 2 other azoles (22.2%). Nine isolates harboured frameshift mutations in a ERG25 homologue that is usually associated with changes in other genes and should be further evaluated. CONCLUSIONS Cyp51A L98H/TR34 was the most common alteration observed among the azole nonwildtype A fumigatus isolates from a large surveillance study; however, only isolates that were nonwildtype to isavuconazole had alterations in multiple analysed genes. These isolates deserve further evaluation.
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19
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Majima H, Arai T, Kusuya Y, Takahashi H, Watanabe A, Miyazaki Y, Kamei K. Genetic differences between Japan and other countries in cyp51A polymorphisms of Aspergillus fumigatus. Mycoses 2021; 64:1354-1365. [PMID: 34558115 DOI: 10.1111/myc.13370] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 09/15/2021] [Accepted: 09/16/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND Mutations in cyp51A gene are known as main mechanisms of azole resistance in Aspergillus fumigatus, whereas azole-susceptible strains also carry cyp51A mutations (polymorphisms). The polymorphisms found in Europe mainly consist of two combinations of mutations, that is combinations of five single-nucleotide polymorphisms (SNPs) of cyp51A, referred to as cyp51A-5SNPs, and combinations of three SNPs of cyp51A, referred to as cyp51A-3SNPs. Few studies have compared the distributions of cyp51A polymorphisms between different regions. OBJECTIVES The aim of this study was to investigate the regional differences of cyp51A polymorphisms. METHODS We compared the proportions of cyp51A polymorphisms in clinical and environmental strains isolated in various countries, and analysed the strains phylogenetically using short tandem repeats (STRs) and whole-genome sequence (WGS). RESULTS Among the Japanese strains, 15 out of 98 (15.3%) clinical strains and 8 out of 95 (8.4%) environmental strains had cyp51A polymorphisms. A mutation of cyp51AN248K was the most prevalent polymorphism in both clinical (n = 14, 14.3%) and environmental strains (n = 3, 3.2%). Only one environmental strain harboured cyp51A-5SNPs, which was reported to be the most prevalent in Europe. For phylogenetic analyses using STRs and WGS, 183 and 134 strains, respectively, were employed. They showed that most of the strains with cyp51AN248K clustered in the clades different from those of the strains with cyp51A-5SNPs and cyp51A-3SNPs as well as from those with TR34 /L98H mutations. CONCLUSIONS This study suggests that there are genetic differences between cyp51A polymorphisms of A. fumigatus in Japan and Europe.
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Affiliation(s)
- Hidetaka Majima
- Division of Clinical Research, Medical Mycology Research Center, Chiba University, Chiba, Japan.,Department of Respiratory Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Teppei Arai
- Division of Clinical Research, Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Yoko Kusuya
- Division of Bioresources, Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Hiroki Takahashi
- Division of Bioresources, Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Akira Watanabe
- Division of Clinical Research, Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Yasunari Miyazaki
- Department of Respiratory Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Katsuhiko Kamei
- Division of Clinical Research, Medical Mycology Research Center, Chiba University, Chiba, Japan
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20
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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: 106] [Impact Index Per Article: 35.3] [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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21
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Morelli KA, Kerkaert JD, Cramer RA. Aspergillus fumigatus biofilms: Toward understanding how growth as a multicellular network increases antifungal resistance and disease progression. PLoS Pathog 2021; 17:e1009794. [PMID: 34437655 PMCID: PMC8389518 DOI: 10.1371/journal.ppat.1009794] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Aspergillus fumigatus is a saprophytic, filamentous fungus found in soils and compost and the causative agent of several pulmonary diseases in humans, birds, and other mammals. A. fumigatus and other filamentous fungi grow as networks of filamentous hyphae that have characteristics of a classic microbial biofilm. These characteristics include production of an extracellular matrix (ECM), surface adhesion, multicellularity, and increased antimicrobial drug resistance. A. fumigatus biofilm growth occurs in vivo at sites of infection, highlighting the importance of defining mechanisms underlying biofilm development and associated emergent properties. We propose that there are 3 distinct phases in the development of A. fumigatus biofilms: biofilm initiation, immature biofilm, and mature biofilm. These stages are defined both temporally and by unique genetic and structural changes over the course of development. Here, we review known mechanisms within each of these stages that contribute to biofilm structure, ECM production, and increased resistance to contemporary antifungal drugs. We highlight gaps in our understanding of biofilm development and function that when addressed are expected to aid in the development of novel antifungal therapies capable of killing filamentous fungal biofilms.
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Affiliation(s)
- Kaesi A. Morelli
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Joshua D. Kerkaert
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Robert A. Cramer
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
- * E-mail:
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22
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Novak-Frazer L, Anees-Hill SP, Hassan D, Masania R, Moore CB, Richardson MD, Denning DW, Rautemaa-Richardson R. Deciphering Aspergillus fumigatus cyp51A-mediated triazole resistance by pyrosequencing of respiratory specimens. J Antimicrob Chemother 2021; 75:3501-3509. [PMID: 32862231 PMCID: PMC7662182 DOI: 10.1093/jac/dkaa357] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 07/16/2020] [Indexed: 12/16/2022] Open
Abstract
Background Infections caused by triazole drug-resistant Aspergillus fumigatus are an increasing problem. The sensitivity of standard culture is poor, abrogating susceptibility testing. Early detection of resistance can improve patient outcomes, yet tools for this purpose are limited. Objectives To develop and validate a pyrosequencing technique to detect resistance-conferring cyp51A polymorphisms from clinical respiratory specimens and A. fumigatus isolates. Methods Method validation was performed by Sanger sequencing and pyrosequencing of 50 A. fumigatus isolates with a spectrum of triazole susceptibility patterns. Then, 326 Aspergillus quantitative PCR (qPCR)-positive respiratory samples collected over a 27 month period (January 2017–March 2019) from 160 patients at the UK National Aspergillosis Centre were assessed by cyp51A pyrosequencing. The Sanger sequencing and pyrosequencing results were compared with those from high-volume culture and standard susceptibility testing. Results The cyp51A genotypes of the 50 isolates analysed by pyrosequencing and Sanger sequencing matched. Of the 326 Aspergillus qPCR-positive respiratory specimens, 71.2% were reported with no A. fumigatus growth. Of these, 56.9% (132/232) demonstrated a WT cyp51A genotype and 31.5% (73/232) a resistant genotype by pyrosequencing. Pyrosequencing identified the environmental TR34/L98H mutation in 18.7% (61/326) of the samples in contrast to 6.4% (21/326) pan-azole resistance detected by culture. Importantly, pyrosequencing detected resistance earlier than culture in 23.3% of specimens. Conclusions The pyrosequencing assay described could detect a wide range of cyp51A polymorphisms associated with triazole resistance, including those not identified by commercial assays. This method allowed prompt recognition of resistance and the selection of appropriate antifungal treatment when culture was negative.
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Affiliation(s)
- Lilyann Novak-Frazer
- Mycology Reference Centre Manchester, ECMM Centre of Excellence, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Wythenshawe Hospital, Manchester, UK.,The University of Manchester, Faculty of Biology, Medicine and Health, Division of Infection, Inflammation and Respiratory Medicine, Manchester, UK
| | - Samuel P Anees-Hill
- Mycology Reference Centre Manchester, ECMM Centre of Excellence, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Wythenshawe Hospital, Manchester, UK
| | - Darin Hassan
- Mycology Reference Centre Manchester, ECMM Centre of Excellence, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Wythenshawe Hospital, Manchester, UK
| | - Rikesh Masania
- Mycology Reference Centre Manchester, ECMM Centre of Excellence, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Wythenshawe Hospital, Manchester, UK
| | - Caroline B Moore
- Mycology Reference Centre Manchester, ECMM Centre of Excellence, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Wythenshawe Hospital, Manchester, UK.,The University of Manchester, Faculty of Biology, Medicine and Health, Division of Infection, Inflammation and Respiratory Medicine, Manchester, UK
| | - Malcolm D Richardson
- Mycology Reference Centre Manchester, ECMM Centre of Excellence, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Wythenshawe Hospital, Manchester, UK.,The University of Manchester, Faculty of Biology, Medicine and Health, Division of Infection, Inflammation and Respiratory Medicine, Manchester, UK
| | - David W Denning
- The University of Manchester, Faculty of Biology, Medicine and Health, Division of Infection, Inflammation and Respiratory Medicine, Manchester, UK.,National Aspergillosis Centre, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Wythenshawe Hospital, Manchester, UK
| | - Riina Rautemaa-Richardson
- Mycology Reference Centre Manchester, ECMM Centre of Excellence, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Wythenshawe Hospital, Manchester, UK.,The University of Manchester, Faculty of Biology, Medicine and Health, Division of Infection, Inflammation and Respiratory Medicine, Manchester, UK.,National Aspergillosis Centre, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Wythenshawe Hospital, Manchester, UK
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23
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Sabino R, Gonçalves P, Martins Melo A, Simões D, Oliveira M, Francisco M, Viegas C, Carvalho D, Martins C, Ferreira T, Toscano C, Simões H, Veríssimo C. Trends on Aspergillus Epidemiology-Perspectives from a National Reference Laboratory Surveillance Program. J Fungi (Basel) 2021; 7:jof7010028. [PMID: 33418997 PMCID: PMC7825284 DOI: 10.3390/jof7010028] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 12/23/2020] [Accepted: 12/30/2020] [Indexed: 12/17/2022] Open
Abstract
Identification of Aspergillus to species level is important since sibling species may display variable susceptibilities to multiple antifungal drugs and also because correct identification contributes to improve the knowledge of epidemiological studies. Two retrospective laboratory studies were conducted on Aspergillus surveillance at the Portuguese National Mycology Reference Laboratory. The first, covering the period 2017–2018, aimed to study the molecular epidemiology of 256 Aspergillus isolates obtained from patients with respiratory, subcutaneous, or systemic infections and from environmental samples. The second, using our entire collection of clinical and environmental A. fumigatus isolates (N = 337), collected between 2012 and 2019, aimed to determine the frequency of azole-resistant A. fumigatus isolates. Aspergillus fumigatus sensu stricto was the most frequent species in both clinical and environmental samples. Overall, and considering all Aspergillus sections identified, a high frequency of cryptic species was detected, based on beta-tubulin or calmodulin sequencing (37% in clinical and 51% in environmental isolates). Regarding all Fumigati isolates recovered from 2012–2019, the frequency of cryptic species was 5.3% (18/337), with the identification of A. felis (complex), A. lentulus, A. udagawae, A. hiratsukae, and A. oerlinghauensis. To determine the frequency of azole resistance of A. fumigatus, isolates were screened for azole resistance using azole-agars, and 53 possible resistant isolates were tested by the CLSI microdilution reference method. Nine A. fumigatus sensu stricto and six Fumigati cryptic isolates showed high minimal inhibitory concentrations to itraconazole, voriconazole, and/or posaconazole. Real-time PCR to detect cyp51A mutations and sequencing of cyp51A gene and its promoter were performed. The overall frequency of resistance to azoles in A. fumigatus sensu stricto was 3.0%. With this retrospective analysis, we were able to detect one azole-resistant G54R mutant A. fumigatus environmental isolate, collected in 2015. The TR34/L98H mutation, linked to environmental transmission route of azole resistance, was the most frequently detected mutation (N = 4; 1.4%). Our findings underline the demand for correct identification and susceptibility testing of Aspergillus isolates.
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Affiliation(s)
- Raquel Sabino
- Infectious Diseases Department, National Health Institute Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (P.G.); (A.M.M.); (D.S.); (M.O.); (M.F.); (H.S.); (C.V.)
- Correspondence: ; Tel.: +351-217519247
| | - Paulo Gonçalves
- Infectious Diseases Department, National Health Institute Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (P.G.); (A.M.M.); (D.S.); (M.O.); (M.F.); (H.S.); (C.V.)
- European Programme for Public Health Microbiology Training (EUPHEM), European Centre for Disease Prevention and Control, 16973 Solna, Sweden
| | - Aryse Martins Melo
- Infectious Diseases Department, National Health Institute Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (P.G.); (A.M.M.); (D.S.); (M.O.); (M.F.); (H.S.); (C.V.)
- Programa de Pós-Graduação em Microbiologia e Parasitologia, Instituto de Biologia, Universidade Federal de Pelotas, Avenida Eliseu Maciel, Pelotas 96010-610, Brazil
| | - Daniela Simões
- Infectious Diseases Department, National Health Institute Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (P.G.); (A.M.M.); (D.S.); (M.O.); (M.F.); (H.S.); (C.V.)
| | - Mariana Oliveira
- Infectious Diseases Department, National Health Institute Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (P.G.); (A.M.M.); (D.S.); (M.O.); (M.F.); (H.S.); (C.V.)
| | - Mariana Francisco
- Infectious Diseases Department, National Health Institute Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (P.G.); (A.M.M.); (D.S.); (M.O.); (M.F.); (H.S.); (C.V.)
| | - Carla Viegas
- H&TRC—Health & Technology Research Center, ESTeSL—Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, 1990-096 Lisbon, Portugal;
- NOVA National School of Public Health, Public Health Research Centre, Universidade NOVA de Lisboa, 1600-560 Lisbon, Portugal
- Comprehensive Health Research Center (CHRC), 1169-056 Lisbon, Portugal
| | - Dinah Carvalho
- Centro Hospitalar Universitário Lisboa Norte EPE, 1649-028 Lisbon, Portugal; (D.C.); (C.M.)
| | - Carlos Martins
- Centro Hospitalar Universitário Lisboa Norte EPE, 1649-028 Lisbon, Portugal; (D.C.); (C.M.)
| | - Teresa Ferreira
- Centro Hospitalar Universitário Lisboa Central, 1050-099 Lisbon, Portugal;
| | - Cristina Toscano
- Microbiology Laboratory, Centro Hospitalar Lisboa Ocidental, Hospital Egas Moniz, 1349-019 Lisbon, Portugal;
| | - Helena Simões
- Infectious Diseases Department, National Health Institute Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (P.G.); (A.M.M.); (D.S.); (M.O.); (M.F.); (H.S.); (C.V.)
| | - Cristina Veríssimo
- Infectious Diseases Department, National Health Institute Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (P.G.); (A.M.M.); (D.S.); (M.O.); (M.F.); (H.S.); (C.V.)
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24
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Chen M, Zhong G, Wang S, Zhu J, Tang L, Li L. tpo3 and dur3, Aspergillus fumigatus Plasma Membrane Regulators of Polyamines, Regulate Polyamine Homeostasis and Susceptibility to Itraconazole. Front Microbiol 2021; 11:563139. [PMID: 33391196 PMCID: PMC7772357 DOI: 10.3389/fmicb.2020.563139] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 11/25/2020] [Indexed: 11/13/2022] Open
Abstract
Aspergillus fumigatus is a well-known opportunistic pathogen that causes invasive aspergillosis (IA) infections, which have high mortality rates in immunosuppressed individuals. Long-term antifungal drug azole use in clinical treatment and agriculture results in loss of efficacy or drug resistance. Drug resistance is related to cellular metabolites and the corresponding gene transcription. In this study, through untargeted metabolomics and transcriptomics under itraconazole (ITC) treatment, we identified two plasma membrane-localized polyamine regulators tpo3 and dur3, which were important for polyamine homeostasis and susceptibility to ITC in A. fumigatus. In the absence of tpo3 and/or dur3, the levels of cytoplasmic polyamines had a moderate increase, which enhanced the tolerance of A. fumigatus to ITC. In comparison, overexpression of tpo3 or dur3 induced a drastic increase in polyamines, which increased the sensitivity of A. fumigatus to ITC. Further analysis revealed that polyamines concentration-dependently affected the susceptibility of A. fumigatus to ITC by scavenging reactive oxygen species (ROS) at a moderate concentration and promoting the production of ROS at a high concentration rather than regulating drug transport. Moreover, inhibition of polyamine biosynthesis reduced the intracellular polyamine content, resulted in accumulation of ROS and enhanced the antifungal activity of ITC. Interestingly, A. fumigatus produces much lower levels of ROS under voriconazole (VOC) treatment than under ITC-treatment. Accordingly, our study established the link among the polyamine regulators tpo3 and dur3, polyamine homeostasis, ROS content, and ITC susceptibility in A. fumigatus.
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Affiliation(s)
- Mingcong Chen
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Guowei Zhong
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Sha Wang
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, Huzhou Central Hospital, Huzhou University, Huzhou, China
| | - Jun Zhu
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Lei Tang
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Lei Li
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
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25
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Fraaije B, Atkins S, Hanley S, Macdonald A, Lucas J. The Multi-Fungicide Resistance Status of Aspergillus fumigatus Populations in Arable Soils and the Wider European Environment. Front Microbiol 2020; 11:599233. [PMID: 33384673 PMCID: PMC7770239 DOI: 10.3389/fmicb.2020.599233] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 11/23/2020] [Indexed: 12/21/2022] Open
Abstract
The evolution and spread of pan-azole resistance alleles in clinical and environmental isolates of Aspergillus fumigatus is a global human health concern. The identification of hotspots for azole resistance development in the wider environment can inform optimal measures to counteract further spread by minimizing exposure to azole fungicides and reducing inoculum build-up and pathogen dispersal. We investigated the fungicide sensitivity status of soil populations sampled from arable crops and the wider environment and compared these with urban airborne populations. Low levels of azole resistance were observed for isolates carrying the CYP51A variant F46Y/M172V/E427K, all belonging to a cluster of related cell surface protein (CSP) types which included t07, t08, t13, t15, t19, and t02B, a new allele. High levels of resistance were found in soil isolates carrying CYP51A variants TR34/L98H and TR46/Y121F/T289A, all belonging to CSP types t01, t02, t04B, or t11. TR46/Y121F/M172V/T289A/G448S (CSP t01) and TR46/Y121F/T289A/S363P/I364V/G448S (CSP t01), a new haplotype associated with high levels of resistance, were isolated from Dutch urban air samples, indicating azole resistance evolution is ongoing. Based on low numbers of pan-azole resistant isolates and lack of new genotypes in soils of fungicide-treated commercial and experimental wheat crops, we consider arable crop production as a coldspot for azole resistance development, in contrast to previously reported flower bulb waste heaps. This study also shows that, in addition to azole resistance, several lineages of A. fumigatus carrying TR-based CYP51A variants have also developed acquired resistance to methyl benzimidazole carbamate, quinone outside inhibitor and succinate dehydrogenase (Sdh) inhibitor fungicides through target-site alterations in the corresponding fungicide target proteins; beta-tubulin (F200Y), cytochrome b (G143A), and Sdh subunit B (H270Y and H270R), respectively. Molecular typing showed that several multi-fungicide resistant strains found in agricultural soils in this study were clonal as identical isolates have been found earlier in the environment and/or in patients. Further research on the spread of different fungicide-resistant alleles from the wider environment to patients and vice versa can inform optimal practices to tackle the further spread of antifungal resistance in A. fumigatus populations and to safeguard the efficacy of azoles for future treatment of invasive aspergillosis.
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Affiliation(s)
- Bart Fraaije
- NIAB, Cambridge, United Kingdom.,Rothamsted Research, Harpenden, United Kingdom
| | | | | | | | - John Lucas
- Rothamsted Research, Harpenden, United Kingdom
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26
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Tunstall T, Portelli S, Phelan J, Clark TG, Ascher DB, Furnham N. Combining structure and genomics to understand antimicrobial resistance. Comput Struct Biotechnol J 2020; 18:3377-3394. [PMID: 33294134 PMCID: PMC7683289 DOI: 10.1016/j.csbj.2020.10.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 10/15/2020] [Accepted: 10/17/2020] [Indexed: 02/07/2023] Open
Abstract
Antimicrobials against bacterial, viral and parasitic pathogens have transformed human and animal health. Nevertheless, their widespread use (and misuse) has led to the emergence of antimicrobial resistance (AMR) which poses a potentially catastrophic threat to public health and animal husbandry. There are several routes, both intrinsic and acquired, by which AMR can develop. One major route is through non-synonymous single nucleotide polymorphisms (nsSNPs) in coding regions. Large scale genomic studies using high-throughput sequencing data have provided powerful new ways to rapidly detect and respond to such genetic mutations linked to AMR. However, these studies are limited in their mechanistic insight. Computational tools can rapidly and inexpensively evaluate the effect of mutations on protein function and evolution. Subsequent insights can then inform experimental studies, and direct existing or new computational methods. Here we review a range of sequence and structure-based computational tools, focussing on tools successfully used to investigate mutational effect on drug targets in clinically important pathogens, particularly Mycobacterium tuberculosis. Combining genomic results with the biophysical effects of mutations can help reveal the molecular basis and consequences of resistance development. Furthermore, we summarise how the application of such a mechanistic understanding of drug resistance can be applied to limit the impact of AMR.
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Affiliation(s)
- Tanushree Tunstall
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Stephanie Portelli
- Computational Biology and Clinical Informatics, Baker Heart and Diabetes Institute, Australia
- Structural Biology and Bioinformatics, Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Australia
| | - Jody Phelan
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Taane G. Clark
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - David B. Ascher
- Computational Biology and Clinical Informatics, Baker Heart and Diabetes Institute, Australia
- Structural Biology and Bioinformatics, Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Australia
| | - Nicholas Furnham
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
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27
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Aspergillus fumigatus Cyp51A and Cyp51B Proteins Are Compensatory in Function and Localize Differentially in Response to Antifungals and Cell Wall Inhibitors. Antimicrob Agents Chemother 2020; 64:AAC.00735-20. [PMID: 32660997 DOI: 10.1128/aac.00735-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 07/06/2020] [Indexed: 02/02/2023] Open
Abstract
Triazole antifungals are the primary therapeutic option against invasive aspergillosis. However, resistance to azoles has increased dramatically over the last decade. Azole resistance is known to primarily occur due to point mutations in the azole target protein Cyp51A, one of two paralogous 14-α sterol demethylases found in Aspergillus fumigatus Despite the importance of Cyp51A, little is known about the function of its paralog, Cyp51B, and the behavior of these proteins within the cell or their functional interrelationship. In this study, we addressed two important aspects of the Cyp51 proteins: (i) we characterized their localization patterns under normal growth versus stress conditions, and (ii) we determined how the proteins compensate for each other's absence and respond to azole treatment. Both the Cyp51A and Cyp51B proteins were found to localize in distinct endoplasmic reticulum (ER) domains, including the perinuclear ER and the peripheral ER. Occasionally, the Cyp51 proteins concentrated in the peripheral ER network of tubules along the hyphal septa and at the hyphal tips. Exposure to voriconazole, caspofungin, and Congo red led to significant increases in fluorescence intensity in these alternative localization sites, indicative of Cyp51 protein translocation in response to cell wall stress. Furthermore, deletion of either Cyp51 paralog increased susceptibility to voriconazole, though a greater effect was observed following deletion of cyp51A, indicating a compensatory response to stress conditions.
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28
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Lavergne RA, Morio F, Danner-Boucher I, Horeau-Langlard D, David V, Hagen F, Meis JF, Le Pape P. One year prospective survey of azole resistance in Aspergillus fumigatus at a French cystic fibrosis reference centre: prevalence and mechanisms of resistance. J Antimicrob Chemother 2020; 74:1884-1889. [PMID: 31038164 DOI: 10.1093/jac/dkz144] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 02/12/2019] [Accepted: 03/08/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Studies on Aspergillus fumigatus azole resistance in cystic fibrosis patients are scarce despite the fact that it is the most frequently isolated fungus from respiratory samples from these individuals. OBJECTIVES To evaluate resistance prevalence, investigate mechanisms of resistance and explore the relationship between resistant isolates by genotyping. METHODS We conducted a prospective 1 year study (from 1 January to 31 December 2015), based on the investigation of up to five colonies per sample from cystic fibrosis patients. RESULTS Twenty-three (6.5%) isolates among the 355 tested were resistant to at least one triazole drug, using the EUCAST reference method, leading to a prevalence of 6.8% (6/88 patients). Analysis of resistance mechanisms highlighted TR34/L98H (n = 10), TR46/Y121F/T289A (n = 1), WT cyp51A (n = 11) and F46Y/M172V/N248T/D255E/E427K (n = 1). No genotype was shared between patients. CONCLUSIONS This study showed a relatively stable resistance prevalence in comparison with the previous study conducted in 2010-11 (8%), although resistance mechanisms varied between the two studies.
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Affiliation(s)
- R-A Lavergne
- Parasitology and Medical Mycology Laboratory, Nantes University Hospital, Nantes, France.,Parasitology and Medical Mycology Department, Nantes University, Nantes Atlantique Universities, EA1155-IICiMed, Institut de Recherche en Santé 2, Nantes, France
| | - F Morio
- Parasitology and Medical Mycology Laboratory, Nantes University Hospital, Nantes, France.,Parasitology and Medical Mycology Department, Nantes University, Nantes Atlantique Universities, EA1155-IICiMed, Institut de Recherche en Santé 2, Nantes, France
| | - I Danner-Boucher
- Department of Pulmonology, Cystic Fibrosis Reference Centre, Nantes University Hospital, Nantes, France
| | - D Horeau-Langlard
- Department of Pulmonology, Cystic Fibrosis Reference Centre, Nantes University Hospital, Nantes, France
| | - V David
- Department of Paediatrics, Nantes University Hospital, Nantes, France
| | - F Hagen
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands.,Department of Medical Mycology, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - J F Meis
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands.,Centre of Expertise in Mycology Radboudumc/CWZ, Nijmegen, The Netherlands
| | - P Le Pape
- Parasitology and Medical Mycology Laboratory, Nantes University Hospital, Nantes, France.,Parasitology and Medical Mycology Department, Nantes University, Nantes Atlantique Universities, EA1155-IICiMed, Institut de Recherche en Santé 2, Nantes, France
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29
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Dos Santos RAC, Steenwyk JL, Rivero-Menendez O, Mead ME, Silva LP, Bastos RW, Alastruey-Izquierdo A, Goldman GH, Rokas A. Genomic and Phenotypic Heterogeneity of Clinical Isolates of the Human Pathogens Aspergillus fumigatus, Aspergillus lentulus, and Aspergillus fumigatiaffinis. Front Genet 2020; 11:459. [PMID: 32477406 PMCID: PMC7236307 DOI: 10.3389/fgene.2020.00459] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 04/14/2020] [Indexed: 12/22/2022] Open
Abstract
Fungal pathogens are a global threat to human health. For example, fungi from the genus Aspergillus cause a spectrum of diseases collectively known as aspergillosis. Most of the >200,000 life-threatening aspergillosis infections per year worldwide are caused by Aspergillus fumigatus. Recently, molecular typing techniques have revealed that aspergillosis can also be caused by organisms that are phenotypically similar to A. fumigatus but genetically distinct, such as Aspergillus lentulus and Aspergillus fumigatiaffinis. Importantly, some of these so-called cryptic species are thought to exhibit different virulence and drug susceptibility profiles than A. fumigatus, however, our understanding of their biology and pathogenic potential has been stymied by the lack of genome sequences and phenotypic profiling of multiple clinical strains. To fill this gap, we phenotypically characterized the virulence and drug susceptibility of 15 clinical strains of A. fumigatus, A. lentulus, and A. fumigatiaffinis from Spain and sequenced their genomes. We found heterogeneity in drug susceptibility across species and strains. We further found heterogeneity in virulence within each species but no significant differences in the virulence profiles between the three species. Genes known to influence drug susceptibility (cyp51A and fks1) vary in paralog number and sequence among these species and strains and correlate with differences in drug susceptibility. Similarly, genes known to be important for virulence in A. fumigatus showed variability in number of paralogs across strains and across species. Characterization of the genomic similarities and differences of clinical strains of A. lentulus, A. fumigatiaffinis, and A. fumigatus that vary in disease-relevant traits will advance our understanding of the variance in pathogenicity between Aspergillus species and strains that are collectively responsible for the vast majority of aspergillosis infections in humans.
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Affiliation(s)
- Renato A C Dos Santos
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil.,Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
| | - Jacob L Steenwyk
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
| | - Olga Rivero-Menendez
- Medical Mycology Reference Laboratory, National Center for Microbiology, Instituto de Salud Carlos III, Madrid, Spain
| | - Matthew E Mead
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
| | - Lilian P Silva
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Rafael W Bastos
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Ana Alastruey-Izquierdo
- Medical Mycology Reference Laboratory, National Center for Microbiology, Instituto de Salud Carlos III, Madrid, Spain
| | - Gustavo H Goldman
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
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30
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Won EJ, Joo MY, Lee D, Kim MN, Park YJ, Kim SH, Shin MG, Shin JH. Antifungal Susceptibility Tests and the cyp51 Mutant Strains among Clinical Aspergillus fumigatus Isolates from Korean Multicenters. MYCOBIOLOGY 2020; 48:148-152. [PMID: 32363043 PMCID: PMC7178884 DOI: 10.1080/12298093.2020.1744955] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/16/2020] [Accepted: 03/16/2020] [Indexed: 06/11/2023]
Abstract
We investigated the antifungal susceptibilities and the cyp51 mutant strains among Aspergillus fumigatus clinical isolates obtained from 10 university hospitals in Korea. Of the 84 isolates examined, two itraconazole-resistant isolates were found with no amino acid substitution in the cyp51A/cyp51B genes. However, 19 (23.2%) azole-susceptible isolates harbored amino acid substitutions: Nine isolates harbored one to five mutations in cyp51A with high polymorphism, and 11 isolates exhibited the same Q42L mutation in cyp51B. Overall, a low azole resistance rate and high frequency of cyp51A/cyp51B amino acid substitutions were observed in the azole-susceptible A. fumigatus isolates in Korea.
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Affiliation(s)
- Eun Jeong Won
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
- Department of Parasitology and Tropical Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Min Young Joo
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Dain Lee
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Mi-Na Kim
- Department of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, South Korea
| | - Yeon-Joon Park
- Department of Laboratory Medicine, The Catholic University of Korea College of Medicine, Seoul, Republic of Korea
| | - Soo Hyun Kim
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
- Department of Microbiology, Chonnam National University Medical School, Gwangju, Korea
| | - Myung Geun Shin
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Jong Hee Shin
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
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31
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A Simple Method To Detect Point Mutations in Aspergillus fumigatus cyp51A Gene Using a Surveyor Nuclease Assay. Antimicrob Agents Chemother 2020; 64:AAC.02271-19. [PMID: 32015034 DOI: 10.1128/aac.02271-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 01/22/2020] [Indexed: 11/20/2022] Open
Abstract
One of the main mechanisms of azole resistance of Aspergillus fumigatus is thought to be a reduction in the drug's affinity for the target molecule, Cyp51A, due to its amino acid mutation(s). It is known that the azole resistance pattern is closely related to the mutation site(s) of the molecule. In this study, we tried to develop a simple and rapid detection method for cyp51A mutations using the endonuclease Surveyor nuclease. The Surveyor nuclease assay was verified using several azole-resistant strains of A. fumigatus that possess point mutations in Cyp51A. For validation of the Surveyor nuclease assay, blind tests were conducted using 48 strains of A. fumigatus (17 azole-resistant and 31 azole-susceptible strains). The Surveyor nuclease assay could rapidly detect cyp51A mutations with one primer set. Also, all the tested strains harboring different cyp51A single point mutations could be clearly distinguished from the wild type. The Surveyor nuclease assay is a simple method that can detect cyp51A mutations rapidly.
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32
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Galleria mellonella for the Evaluation of Antifungal Efficacy against Medically Important Fungi, a Narrative Review. Microorganisms 2020. [DOI: 10.3390/microorganisms8030390
expr 890942362 + 917555800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
The treatment of invasive fungal infections remains challenging and the emergence of new fungal pathogens as well as the development of resistance to the main antifungal drugs highlight the need for novel therapeutic strategies. Although in vitro antifungal susceptibility testing has come of age, the proper evaluation of therapeutic efficacy of current or new antifungals is dependent on the use of animal models. Mammalian models, particularly using rodents, are the cornerstone for evaluation of antifungal efficacy, but are limited by increased costs and ethical considerations. To circumvent these limitations, alternative invertebrate models, such as Galleria mellonella, have been developed. Larvae of G. mellonella have been widely used for testing virulence of fungi and more recently have proven useful for evaluation of antifungal efficacy. This model is suitable for infection by different fungal pathogens including yeasts (Candida, Cryptococcus, Trichosporon) and filamentous fungi (Aspergillus, Mucorales). Antifungal efficacy may be easily estimated by fungal burden or mortality rate in infected and treated larvae. The aim of the present review is to summarize the actual data about the use of G. mellonella for testing the in vivo efficacy of licensed antifungal drugs, new drugs, and combination therapies.
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33
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Jemel S, Guillot J, Kallel K, Botterel F, Dannaoui E. Galleria mellonella for the Evaluation of Antifungal Efficacy against Medically Important Fungi, a Narrative Review. Microorganisms 2020; 8:microorganisms8030390. [PMID: 32168839 PMCID: PMC7142887 DOI: 10.3390/microorganisms8030390] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/05/2020] [Accepted: 03/08/2020] [Indexed: 12/26/2022] Open
Abstract
The treatment of invasive fungal infections remains challenging and the emergence of new fungal pathogens as well as the development of resistance to the main antifungal drugs highlight the need for novel therapeutic strategies. Although in vitro antifungal susceptibility testing has come of age, the proper evaluation of therapeutic efficacy of current or new antifungals is dependent on the use of animal models. Mammalian models, particularly using rodents, are the cornerstone for evaluation of antifungal efficacy, but are limited by increased costs and ethical considerations. To circumvent these limitations, alternative invertebrate models, such as Galleria mellonella, have been developed. Larvae of G. mellonella have been widely used for testing virulence of fungi and more recently have proven useful for evaluation of antifungal efficacy. This model is suitable for infection by different fungal pathogens including yeasts (Candida, Cryptococcus, Trichosporon) and filamentous fungi (Aspergillus, Mucorales). Antifungal efficacy may be easily estimated by fungal burden or mortality rate in infected and treated larvae. The aim of the present review is to summarize the actual data about the use of G. mellonella for testing the in vivo efficacy of licensed antifungal drugs, new drugs, and combination therapies.
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Affiliation(s)
- Sana Jemel
- EA Dynamyc UPEC, EnvA, USC Anses, Faculté de Médecine de Créteil, 94000 Créteil, France; (S.J.); (J.G.); (F.B.)
- Université Tunis EL Manar, Faculté de médecine de Tunis, Tunis 1007, Tunisie;
- UR17SP03, centre hospitalo-universitaire La Rabta, Jabbari, Tunis 1007, Tunisie
| | - Jacques Guillot
- EA Dynamyc UPEC, EnvA, USC Anses, Faculté de Médecine de Créteil, 94000 Créteil, France; (S.J.); (J.G.); (F.B.)
| | - Kalthoum Kallel
- Université Tunis EL Manar, Faculté de médecine de Tunis, Tunis 1007, Tunisie;
- UR17SP03, centre hospitalo-universitaire La Rabta, Jabbari, Tunis 1007, Tunisie
| | - Françoise Botterel
- EA Dynamyc UPEC, EnvA, USC Anses, Faculté de Médecine de Créteil, 94000 Créteil, France; (S.J.); (J.G.); (F.B.)
| | - Eric Dannaoui
- EA Dynamyc UPEC, EnvA, USC Anses, Faculté de Médecine de Créteil, 94000 Créteil, France; (S.J.); (J.G.); (F.B.)
- Hôpital Européen Georges Pompidou, APHP, Unité de Parasitologie-Mycologie, Service de Microbiologie, 75015 Paris, France
- Université René Descartes, Faculté de médecine, 75006 Paris, France
- Correspondence: ; Tel.: +33-1-56-09-39-48; Fax: +33-1-56-09-24-46
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34
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Azole resistance mechanisms in Aspergillus: update and recent advances. Int J Antimicrob Agents 2020; 55:105807. [DOI: 10.1016/j.ijantimicag.2019.09.011] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 09/05/2019] [Accepted: 09/15/2019] [Indexed: 12/11/2022]
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35
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Zakaria A, Osman M, Dabboussi F, Rafei R, Mallat H, Papon N, Bouchara JP, Hamze M. Recent trends in the epidemiology, diagnosis, treatment, and mechanisms of resistance in clinical Aspergillus species: A general review with a special focus on the Middle Eastern and North African region. J Infect Public Health 2019; 13:1-10. [PMID: 31672427 DOI: 10.1016/j.jiph.2019.08.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 08/02/2019] [Accepted: 08/19/2019] [Indexed: 12/16/2022] Open
Abstract
Globally, more than billion people suffer from fungal infections each year. The early diagnosis of aspergillosis is mandatory for successful treatment outcome. As careful testing takes time, epidemiological surveillance is crucial to guide individual patient therapy and to promote a high standard of health care. In this paper, we first present current trends in the epidemiology and antifungal susceptibility patterns of Aspergillus spp. in Middle Eastern and North African (MENA) countries in order to support infectious disease specialists and health workforces in this geographic area to treat adequately patients with aspergillosis. Then we discuss the existing literature data regarding the available diagnostic tools and antifungal resistance mechanisms of Aspergillus spp. Although a limited number of studies were reviewed here, the currently available data show that Aspergillus infections are not negligible in the MENA region, and that the emergence of antifungal resistance is a growing health issue, especially among immunocompromised patients.
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Affiliation(s)
- Ayate Zakaria
- Laboratoire Microbiologie Santé et Environnement (LMSE), Doctoral School of Science and Technology, Faculty of Public Health, Lebanese University, Tripoli, Lebanon
| | - Marwan Osman
- Laboratoire Microbiologie Santé et Environnement (LMSE), Doctoral School of Science and Technology, Faculty of Public Health, Lebanese University, Tripoli, Lebanon
| | - Fouad Dabboussi
- Laboratoire Microbiologie Santé et Environnement (LMSE), Doctoral School of Science and Technology, Faculty of Public Health, Lebanese University, Tripoli, Lebanon
| | - Rayane Rafei
- Laboratoire Microbiologie Santé et Environnement (LMSE), Doctoral School of Science and Technology, Faculty of Public Health, Lebanese University, Tripoli, Lebanon
| | - Hassan Mallat
- Laboratoire Microbiologie Santé et Environnement (LMSE), Doctoral School of Science and Technology, Faculty of Public Health, Lebanese University, Tripoli, Lebanon
| | - Nicolas Papon
- Groupe d'Etude des Interactions Hôte-Pathogène (GEIHP), EA 3142, SFR 4208 ICAT, UNIV Angers, UNIV Brest, Angers, France
| | - Jean-Philippe Bouchara
- Groupe d'Etude des Interactions Hôte-Pathogène (GEIHP), EA 3142, SFR 4208 ICAT, UNIV Angers, UNIV Brest, Angers, France
| | - Monzer Hamze
- Laboratoire Microbiologie Santé et Environnement (LMSE), Doctoral School of Science and Technology, Faculty of Public Health, Lebanese University, Tripoli, Lebanon.
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36
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cyp51A Mutations, Extrolite Profiles, and Antifungal Susceptibility in Clinical and Environmental Isolates of the Aspergillus viridinutans Species Complex. Antimicrob Agents Chemother 2019; 63:AAC.00632-19. [PMID: 31451501 PMCID: PMC6811395 DOI: 10.1128/aac.00632-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 08/16/2019] [Indexed: 02/06/2023] Open
Abstract
The past decade has seen an increase in aspergillosis in humans and animals due to Aspergillus viridinutans species complex members. Azole resistance is common to these infections, carrying a poor prognosis. cyp51A gene mutations are the main cause of acquired azole resistance in Aspergillus fumigatus. This study aimed to determine if the azole-resistant phenotype in A. viridinutans complex members is associated with cyp51A mutations or extrolite profiles. The past decade has seen an increase in aspergillosis in humans and animals due to Aspergillus viridinutans species complex members. Azole resistance is common to these infections, carrying a poor prognosis. cyp51A gene mutations are the main cause of acquired azole resistance in Aspergillus fumigatus. This study aimed to determine if the azole-resistant phenotype in A. viridinutans complex members is associated with cyp51A mutations or extrolite profiles. The cyp51A gene of clinical and environmental isolates was amplified using novel primers, antifungal susceptibility was tested using the Clinical and Laboratory Standards Institute methodology, and extrolite profiling was performed using agar plug extraction. Very high azole MICs were detected in 84% of the isolates (31/37). The MICs of the newer antifungals luliconazole and olorofim (F901318) were low for all isolates. cyp51A sequences revealed 113 nonsynonymous mutations compared to the sequence of wild-type A. fumigatus. M172A/V and D255G, previously associated with A. fumigatus azole resistance, were common among all isolates but were not correlated with azole MICs. Two environmental isolates with nonsusceptibility to itraconazole and high MICs of voriconazole and isavuconazole harbored G138C, previously associated with azole-resistant A. fumigatus. Some novel mutations were identified only among isolates with high azole MICs. However, cyp51A homology modeling did not cause a significant protein structure change for these mutations. There was no correlation between extrolite patterns and susceptibility. For A. viridinutans complex isolates, cyp51A mutations and the extrolites that they produced were not major causes of antifungal resistance. Luliconazole and olorofim show promise for treating azole-resistant infections caused by these cryptic species.
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37
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Hare RK, Gertsen JB, Astvad KMT, Degn KB, Løkke A, Stegger M, Andersen PS, Kristensen L, Arendrup MC. In Vivo Selection of a Unique Tandem Repeat Mediated Azole Resistance Mechanism (TR 120) in Aspergillus fumigatus cyp51A, Denmark. Emerg Infect Dis 2019; 25:577-580. [PMID: 30789127 PMCID: PMC6390761 DOI: 10.3201/eid2503.180297] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We report a fatal aspergillosis case in which STRAf typing and whole-genome sequencing substantiated in vivo emergence of an azole-resistant Aspergillus fumigatus with a 120-bp tandem repeat in the promoter region of cyp51A. This event, previously restricted to the environment, challenges current understanding of azole resistance development in A. fumigatus.
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38
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Monk BC, Sagatova AA, Hosseini P, Ruma YN, Wilson RK, Keniya MV. Fungal Lanosterol 14α-demethylase: A target for next-generation antifungal design. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2019; 1868:140206. [PMID: 30851431 DOI: 10.1016/j.bbapap.2019.02.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 02/15/2019] [Accepted: 02/21/2019] [Indexed: 12/19/2022]
Abstract
The cytochrome P450 enzyme lanosterol 14α-demethylase (LDM) is the target of the azole antifungals used widely in medicine and agriculture as prophylaxis or treatments of infections or diseases caused by fungal pathogens. These drugs and agrochemicals contain an imidazole, triazole or tetrazole substituent, with one of the nitrogens in the azole ring coordinating as the sixth axial ligand to the LDM heme iron. Structural studies show that this membrane bound enzyme contains a relatively rigid ligand binding pocket comprised of a deeply buried heme-containing active site together with a substrate entry channel and putative product exit channel that reach to the membrane. Within the ligand binding pocket the azole antifungals have additional affinity determining interactions with hydrophobic side-chains, the polypeptide backbone and via water-mediated hydrogen bond networks. This review will describe the tools that can be used to identify and characterise the next generation of antifungals targeting LDM, with the goal of obtaining highly potent broad-spectrum fungicides that will be able to avoid target and drug efflux mediated antifungal resistance.
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Affiliation(s)
- Brian C Monk
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
| | - Alia A Sagatova
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Parham Hosseini
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Yasmeen N Ruma
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Rajni K Wilson
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Mikhail V Keniya
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand
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39
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Garcia-Rubio R, Escribano P, Gomez A, Guinea J, Mellado E. Comparison of Two Highly Discriminatory Typing Methods to Analyze Aspergillus fumigatus Azole Resistance. Front Microbiol 2018; 9:1626. [PMID: 30079058 PMCID: PMC6062602 DOI: 10.3389/fmicb.2018.01626] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 06/28/2018] [Indexed: 11/24/2022] Open
Abstract
Aspergillus fumigatus molecular typing has become increasingly more important for detecting outbreaks as well as for local and global epidemiological investigations and surveillance. Over the years, many different molecular methods have been described for genotyping this species. Some outstanding approaches are based on microsatellite markers (STRAf assay, which is the current gold standard), or based on sequencing data (TRESP typing improved in this work with a new marker and was renamed TRESPERG). Both methodologies were used to type a collection of 212 A. fumigatus isolates that included 70 azole resistant strains with diverse resistance mechanisms from different geographic locations. Our results showed that both methods are totally reliable for epidemiological investigations showing similar stratification of the A. fumigatus population. STRAf assay offered higher discriminatory power (D = 0.9993) than the TRESPERG typing method (D = 0.9972), but the latter does not require specific equipment or skilled personnel, allowing for a prompt integration into any clinical microbiology laboratory. Among azole resistant isolates, two groups were differentiated considering their resistance mechanisms: cyp51A single point mutations (G54, M220, or G448), and promoter tandem repeat integrations with or without cyp51A modifications (TR34/L98H, TR46/Y121F/A289T, or TR53). The genotypic differences were assessed to explore the population structure as well as the genetic relationship between strains and their azole resistance profile. Genetic cluster analyses suggested that our A. fumigatus population was formed by 6–7 clusters, depending on the methodology. Also, the azole susceptible and resistance population showed different structure and organization. The combination of both methodologies resolved the population structure in a similar way to what has been described in whole-genome sequencing works.
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Affiliation(s)
- Rocio Garcia-Rubio
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Madrid, Spain
| | - Pilar Escribano
- Department of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain.,Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | - Ana Gomez
- Department of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain.,Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | - Jesus Guinea
- Department of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain.,Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain.,Department of Medicine, School of Medicine, Complutense University of Madrid, Madrid, Spain
| | - Emilia Mellado
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Madrid, Spain
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40
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Garcia-Rubio R, Monzon S, Alcazar-Fuoli L, Cuesta I, Mellado E. Genome-Wide Comparative Analysis of Aspergillus fumigatus Strains: The Reference Genome as a Matter of Concern. Genes (Basel) 2018; 9:E363. [PMID: 30029559 PMCID: PMC6071029 DOI: 10.3390/genes9070363] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 07/13/2018] [Accepted: 07/16/2018] [Indexed: 12/11/2022] Open
Abstract
Aspergillus fumigatus is a ubiquitous saprophytic mold and a major pathogen in immunocompromised patients. The effectiveness of triazole compounds, the A. fumigatus first line treatment, is being threatened by a rapid and global emergence of azole resistance. Whole genome sequencing (WGS) has emerged as an invaluable tool for the analysis of genetic differences between A. fumigatus strains, their genetic background, and antifungal resistance development. Although WGS analyses can provide a valuable amount of novel information, there are some limitations that should be considered. These analyses, based on genome-wide comparative data and single nucleotide variant (SNV) calling, are dependent on the quality of sequencing, assembling, the variant calling criteria, as well as on the suitable selection of the reference genome, which must be genetically close to the genomes included in the analysis. In this study, 28 A. fumigatus genomes sequenced in-house and 73 available in public data bases have been analyzed. All genomes were distributed in four clusters and showed a variable number of SNVs depending on the genome used as reference (Af293 or A1163). Each reference genome belonged to a different cluster. The results highlighted the importance of choosing the most suitable A. fumigatus reference genome to avoid misleading conclusions.
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Affiliation(s)
- Rocio Garcia-Rubio
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, 28220 Madrid, Spain.
| | - Sara Monzon
- Bioinformatics Unit, Common Scientific Technical Units, ISCIII, Majadahonda, 28220 Madrid, Spain.
| | - Laura Alcazar-Fuoli
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, 28220 Madrid, Spain.
| | - Isabel Cuesta
- Bioinformatics Unit, Common Scientific Technical Units, ISCIII, Majadahonda, 28220 Madrid, Spain.
| | - Emilia Mellado
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, 28220 Madrid, Spain.
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