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Arendrup MC, Hare RK, Jørgensen KM, Bollmann UE, Bech TB, Hansen CC, Heick TM, Jørgensen LN. Environmental Hot Spots and Resistance-Associated Application Practices for Azole-Resistant Aspergillus fumigatus, Denmark, 2020-2023. Emerg Infect Dis 2024; 30:1531-1541. [PMID: 38935978 PMCID: PMC11286046 DOI: 10.3201/eid3008.240096] [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] [Indexed: 06/29/2024] Open
Abstract
Azole-resistant Aspergillus fumigatus (ARAf) fungi have been found inconsistently in the environment in Denmark since 2010. During 2018-2020, nationwide surveillance of clinical A. fumigatus fungi reported environmental TR34/L98H or TR46/Y121F/T289A resistance mutations in 3.6% of isolates, prompting environmental sampling for ARAf and azole fungicides and investigation for selection of ARAf in field and microcosmos experiments. ARAf was ubiquitous (20% of 366 samples; 16% TR34/L98H- and 4% TR46/Y121F/T289A-related mechanisms), constituting 4.2% of 4,538 A. fumigatus isolates. The highest proportions were in flower- and compost-related samples but were not correlated with azole-fungicide application concentrations. Genotyping showed clustering of tandem repeat-related ARAf and overlaps with clinical isolates in Denmark. A. fumigatus fungi grew poorly in the field experiment with no postapplication change in ARAf proportions. However, in microcosmos experiments, a sustained complete (tebuconazole) or partial (prothioconazole) inhibition against wild-type A. fumigatus but not ARAf indicated that, under some conditions, azole fungicides may favor growth of ARAf in soil.
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Gutierrez-Perez C, Puerner C, Jones JT, Vellanki S, Vesely EM, Xatse MA, Viera AFC, Olsen CP, Attiku KO, Cardinale S, Kwasny SM, G-Dayanandan N, Opperman TJ, Cramer RA. Unsaturated fatty acid perturbation combats emerging triazole antifungal resistance in the human fungal pathogen Aspergillus fumigatus. mBio 2024; 15:e0116624. [PMID: 38934618 PMCID: PMC11253624 DOI: 10.1128/mbio.01166-24] [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: 04/18/2024] [Accepted: 05/02/2024] [Indexed: 06/28/2024] Open
Abstract
Contemporary antifungal therapies utilized to treat filamentous fungal infections are inhibited by intrinsic and emerging drug resistance. Consequently, there is an urgent need to develop novel antifungal compounds that are effective against drug-resistant filamentous fungi. Here, we utilized an Aspergillus fumigatus cell-based high-throughput screen to identify small molecules with antifungal activity that also potentiated triazole activity. The screen identified 16 hits with promising activity against A. fumigatus. A nonspirocyclic piperidine, herein named MBX-7591, exhibited synergy with triazole antifungal drugs and activity against pan-azole-resistant A. fumigatus isolates. MBX-7591 has additional potent activity against Rhizopus species and CO2-dependent activity against Cryptococcus neoformans. Chemical, genetic, and biochemical mode of action analyses revealed that MBX-7591 increases cell membrane saturation by decreasing oleic acid content. MBX-7591 has low toxicity in vivo and shows good efficacy in decreasing fungal burden in a murine model of invasive pulmonary aspergillosis. Taken together, our results suggest MBX-7591 is a promising hit with a novel mode of action for further antifungal drug development to combat the rising incidence of triazole-resistant filamentous fungal infections.IMPORTANCEThe incidence of infections caused by fungi continues to increase with advances in medical therapies. Unfortunately, antifungal drug development has not kept pace with the incidence and importance of fungal infections, with only three major classes of antifungal drugs currently available for use in the clinic. Filamentous fungi, also called molds, are particularly recalcitrant to contemporary antifungal therapies. Here, a recently developed Aspergillus fumigatus cell reporter strain was utilized to conduct a high-throughput screen to identify small molecules with antifungal activity. An emphasis was placed on small molecules that potentiated the activity of contemporary triazole antifungals and led to the discovery of MBX-7591. MBX-7591 potentiates triazole activity against drug-resistant molds such as A. fumigatus and has activity against Mucorales fungi. MBX-7591's mode of action involves inhibiting the conversion of saturated to unsaturated fatty acids, thereby impacting fungal membrane integrity. MBX-7591 is a novel small molecule with antifungal activity poised for lead development.
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Affiliation(s)
- Cecilia Gutierrez-Perez
- Microbiology and Immunology Department, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, USA
| | - Charles Puerner
- Microbiology and Immunology Department, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, USA
| | - Jane T. Jones
- Microbiology and Immunology Department, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, USA
| | - Sandeep Vellanki
- Microbiology and Immunology Department, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, USA
| | - Elisa M. Vesely
- Microbiology and Immunology Department, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, USA
| | - Mark A. Xatse
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Andre F. C. Viera
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Carissa P. Olsen
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Keren O. Attiku
- Microbiology and Immunology Department, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, USA
| | | | | | | | | | - Robert A. Cramer
- Microbiology and Immunology Department, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, USA
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Djenontin E, Debourgogne A, Mousavi B, Delhaes L, Cornet M, Valsecchi I, Adebo M, Guillot J, Botterel F, Dannaoui E. Azole resistance in Aspergillus flavus and associated fitness cost. Mycoses 2024; 67:e13766. [PMID: 39007526 DOI: 10.1111/myc.13766] [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: 03/04/2024] [Revised: 06/26/2024] [Accepted: 06/30/2024] [Indexed: 07/16/2024]
Abstract
BACKGROUND The resistance of Aspergillus flavus to the azole antifungal drugs is an emerging problem. Mutations in the molecular targets of the azole antifungals - CYP 51 A, B and C - are possible mechanisms of resistance, but data to confirm this hypothesis are scarce. In addition, the behaviour of resistant strains in vitro and in vivo is not yet understood. OBJECTIVES This study had 3 objectives. The first was to compare the sequences of CYP51 A, B and C in resistant and susceptible strains of A. flavus. The second was to look for the existence of a fitness cost associated with resistance. The third was to evaluate the activity of voriconazole and posaconazole on resistant strains in the Galleria mellonella model. METHODS The CYP51 A, B and C sequences of seven resistant strains with those of four susceptible strains are compared. Fitness costs were assessed by growing the strains in RPMI medium and testing their virulence in G. mellonella larvae. In addition, G. mellonella larvae infected with strains of A. flavus were treated with voriconazole and posaconazole. RESULTS In the CYP51A sequences, we found the A91T, C708T and A1296T nucleotide substitutions only in the resistant strains. The resistant strains showed a fitness cost with reduced in vitro growth and reduced virulence in G. mellonella. In vivo resistance to posaconazole is confirmed in a strain with the highest MIC for this antifungal agent. CONCLUSIONS These results allow to conclude that some substitutions in CYP51 genes, in particular CYP51A, contribute to resistance to azole drugs in A. flavus. The study of the relationship between drug dosage and treatment duration with resistance and the reduction of fitness costs in resistant strains is a major perspective of this study. This work could help to establish recommendations for the treatment of infections with resistant strains of A. flavus.
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Affiliation(s)
- Elie Djenontin
- Unité de Parasitologie-Mycologie, Département de Virologie, Bactériologie-Hygiène, Parasitologie-Mycologie, CHU Henri Mondor, AP-HP, Créteil, France
- UR Dynamyc UPEC, EnvA, ANSES. Faculté de Santé de Créteil, Créteil, France
| | - Anne Debourgogne
- UR7300 Stress Immunité Pathogène, Université de Lorraine, Vandoeuvre les Nancy, France
| | - Bita Mousavi
- UR Dynamyc UPEC, EnvA, ANSES. Faculté de Santé de Créteil, Créteil, France
| | - Laurence Delhaes
- CHU de Bordeaux: Laboratoire de Parasitologie-Mycologie, CNR des Aspergilloses Chroniques, INSERM U1045: Univ. Bordeaux, Bordeaux, France
| | - Muriel Cornet
- Université Grenoble Alpes, CNRS, Grenoble INP, CHU Grenoble Alpes, TIMC, Grenoble, France
| | - Isabel Valsecchi
- Unité de Parasitologie-Mycologie, Département de Virologie, Bactériologie-Hygiène, Parasitologie-Mycologie, CHU Henri Mondor, AP-HP, Créteil, France
| | - Makiath Adebo
- UR Dynamyc UPEC, EnvA, ANSES. Faculté de Santé de Créteil, Créteil, France
| | | | - Françoise Botterel
- Unité de Parasitologie-Mycologie, Département de Virologie, Bactériologie-Hygiène, Parasitologie-Mycologie, CHU Henri Mondor, AP-HP, Créteil, France
- UR Dynamyc UPEC, EnvA, ANSES. Faculté de Santé de Créteil, Créteil, France
| | - Eric Dannaoui
- Unité de Parasitologie-Mycologie, Département de Virologie, Bactériologie-Hygiène, Parasitologie-Mycologie, CHU Henri Mondor, AP-HP, Créteil, France
- Unité de Parasitologie-Mycologie, Service de Microbiologie, Hôpital Necker, AP-HP, Paris, France
- Université Paris Cité, Faculté de Médecine, Paris, France
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Pontes L, Perini Leme Giordano AL, Reichert-Lima F, Gualtieri Beraquet CA, Leite Pigolli G, Arai T, Ribeiro JD, Gonçalves AC, Watanabe A, Goldman GH, Moretti ML, Zaninelli Schreiber A. Insights into Aspergillus fumigatus Colonization in Cystic Fibrosis and Cross-Transmission between Patients and Hospital Environments. J Fungi (Basel) 2024; 10:461. [PMID: 39057346 PMCID: PMC11277961 DOI: 10.3390/jof10070461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 06/04/2024] [Accepted: 06/12/2024] [Indexed: 07/28/2024] Open
Abstract
BACKGROUND Approximately 60% of individuals with cystic fibrosis (CF) are affected by Aspergillus fumigatus infection. This condition is correlated with a decline in lung function and is identified as an independent risk factor contributing to hospital admissions among CF patients. This study investigates the dynamic interplay of A. fumigatus within the context of CF patients, tracing its evolution over time, with a specific emphasis on colonization dynamics. METHODS An analysis was conducted on 83 sequential A. fumigatus isolates derived from sputum samples of six patients receiving care at a renowned CF hospital in Brazil. Employing microsatellite genotyping techniques, alongside an investigation into cyp51A gene mutations, this research sheds light on the genetic variations, colonization, and resistance of A. fumigatus within the CF respiratory environment. RESULTS Our research findings indicate that CF patients can harbor A. fumigatus strains from the same clonal complexes for prolonged periods. Additionally, we identified that clinical isolates have the potential to spread among patients in the same healthcare facility, evidencing hospital contamination. Two patients who underwent long-term Itraconazole treatment did not show phenotypic resistance. However, one of these patients exhibited mutations in the cyp51A gene, indicating the need to monitor resistance to azoles in these patients colonized for long periods by A. fumigatus. We also observed co-colonization or co-infection involving multiple genotypes in all patients over time. CONCLUSION This comprehensive examination offers valuable insights into the pathogenesis of A. fumigatus infections in CF patients, potentially shaping future therapeutic strategies and management approaches. This enhanced understanding contributes to our knowledge of A. fumigatus impact on disease progression in individuals with cystic fibrosis. Additionally, the study provides evidence of cross-contamination among patients undergoing treatment at the same hospital.
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Affiliation(s)
- Laís Pontes
- Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas 13083-887, Brazil; (A.L.P.L.G.); (F.R.-L.); (C.A.G.B.); (G.L.P.); (J.D.R.); (A.C.G.); (M.L.M.)
| | - Ana Luisa Perini Leme Giordano
- Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas 13083-887, Brazil; (A.L.P.L.G.); (F.R.-L.); (C.A.G.B.); (G.L.P.); (J.D.R.); (A.C.G.); (M.L.M.)
| | - Franqueline Reichert-Lima
- Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas 13083-887, Brazil; (A.L.P.L.G.); (F.R.-L.); (C.A.G.B.); (G.L.P.); (J.D.R.); (A.C.G.); (M.L.M.)
| | - Caio Augusto Gualtieri Beraquet
- Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas 13083-887, Brazil; (A.L.P.L.G.); (F.R.-L.); (C.A.G.B.); (G.L.P.); (J.D.R.); (A.C.G.); (M.L.M.)
| | - Guilherme Leite Pigolli
- Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas 13083-887, Brazil; (A.L.P.L.G.); (F.R.-L.); (C.A.G.B.); (G.L.P.); (J.D.R.); (A.C.G.); (M.L.M.)
| | - Teppei Arai
- Division of Clinical Research, Medical Mycology Research Center, Chiba University, Chiba 260-0856, Japan; (T.A.); (A.W.)
| | - José Dirceu Ribeiro
- Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas 13083-887, Brazil; (A.L.P.L.G.); (F.R.-L.); (C.A.G.B.); (G.L.P.); (J.D.R.); (A.C.G.); (M.L.M.)
| | - Aline Cristina Gonçalves
- Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas 13083-887, Brazil; (A.L.P.L.G.); (F.R.-L.); (C.A.G.B.); (G.L.P.); (J.D.R.); (A.C.G.); (M.L.M.)
| | - Akira Watanabe
- Division of Clinical Research, Medical Mycology Research Center, Chiba University, Chiba 260-0856, Japan; (T.A.); (A.W.)
| | - Gustavo Henrique Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-903, Brazil;
| | - Maria Luiza Moretti
- Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas 13083-887, Brazil; (A.L.P.L.G.); (F.R.-L.); (C.A.G.B.); (G.L.P.); (J.D.R.); (A.C.G.); (M.L.M.)
| | - Angélica Zaninelli Schreiber
- Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas 13083-887, Brazil; (A.L.P.L.G.); (F.R.-L.); (C.A.G.B.); (G.L.P.); (J.D.R.); (A.C.G.); (M.L.M.)
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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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Ghorbel D, Amouri I, Khemekhem N, Neji S, Trabelsi H, Elloumi M, Sellami H, Makni F, Ayadi A, Hadrich I. Investigation of Azole Resistance Involving cyp51A and cyp51B Genes in Clinical Aspergillus flavus Isolates. Pol J Microbiol 2024; 73:131-142. [PMID: 38700908 PMCID: PMC11192525 DOI: 10.33073/pjm-2024-001] [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: 08/03/2023] [Accepted: 12/03/2023] [Indexed: 06/22/2024] Open
Abstract
This study aimed to investigate azole resistance mechanisms in Aspergillus flavus, which involve cyp51A and cyp51B genes. Real-time Reverse Transcriptase qPCR method was applied to determine the overexpression of cyp51A and cyp51B genes for 34 A. flavus isolates. PCR sequencing of these two genes was used to detect the presence of gene mutations. Susceptibility test found sensitivity to voriconazole (VOR) in all strains. 14.7% and 8.8% of isolates were resistant to itraconazole (IT) and posaconazole (POS), respectively, with a cross-resistance in 5.8%. For the double resistant isolates (IT/POS), the expression of cyp51A was up to 17-fold higher. PCR sequencing showed the presence of 2 mutations in cyp51A: a synonymous point mutation (P61P) in eight isolates, which did not affect the structure of CYP51A protein, and another non synonymous mutation (G206L) for only the TN-33 strain (cross IT/POS resistance) causing an amino acid change in the protein sequence. However, we noted in cyp51B the presence of the only non-synonymous mutation (L177G) causing a change in amino acids in the protein sequence for the TN-31 strain, which exhibits IT/POS cross-resistance. A short single intron of 67 bp was identified in the cyp51A gene, whereas three short introns of 54, 53, and 160 bp were identified in the cyp51B gene. According to the models provided by PatchDock software, the presence of non-synonymous mutations did not affect the interaction of CYP51A and CYP51B proteins with antifungals. In our study, the overexpression of the cyp51A and cyp51B genes is the primary mechanism responsible for resistance in A. flavus collection. Nevertheless, other resistance mechanisms can be involved.
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Affiliation(s)
- Dhoha Ghorbel
- 1Fungi and Parasitic Molecular Biology Laboratory, School of Medicine, University of Sfax, Sfax, Tunisia
| | - Imen Amouri
- 1Fungi and Parasitic Molecular Biology Laboratory, School of Medicine, University of Sfax, Sfax, Tunisia
| | - Nahed Khemekhem
- 1Fungi and Parasitic Molecular Biology Laboratory, School of Medicine, University of Sfax, Sfax, Tunisia
| | - Sourour Neji
- 1Fungi and Parasitic Molecular Biology Laboratory, School of Medicine, University of Sfax, Sfax, Tunisia
| | - Houaida Trabelsi
- 1Fungi and Parasitic Molecular Biology Laboratory, School of Medicine, University of Sfax, Sfax, Tunisia
| | - Moez Elloumi
- 3Haematology Department, UH Hedi Chaker, Sfax, Tunisia
| | - Hayet Sellami
- 1Fungi and Parasitic Molecular Biology Laboratory, School of Medicine, University of Sfax, Sfax, Tunisia
| | - Fattouma Makni
- 1Fungi and Parasitic Molecular Biology Laboratory, School of Medicine, University of Sfax, Sfax, Tunisia
| | - Ali Ayadi
- 1Fungi and Parasitic Molecular Biology Laboratory, School of Medicine, University of Sfax, Sfax, Tunisia
| | - Ines Hadrich
- 1Fungi and Parasitic Molecular Biology Laboratory, School of Medicine, University of Sfax, Sfax, Tunisia
- 2Faculty of Science, University of Gabes, Gabes, Tunisia
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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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Hargrove T, Lamb DC, Wawrzak Z, Hull M, Kelly SL, Guengerich FP, Lepesheva GI. Identification of Potent and Selective Inhibitors of Acanthamoeba: Structural Insights into Sterol 14α-Demethylase as a Key Drug Target. J Med Chem 2024; 67:7443-7457. [PMID: 38683753 PMCID: PMC11089504 DOI: 10.1021/acs.jmedchem.4c00303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/27/2024] [Accepted: 04/22/2024] [Indexed: 05/02/2024]
Abstract
Acanthamoeba are free-living pathogenic protozoa that cause blinding keratitis, disseminated infection, and granulomatous amebic encephalitis, which is generally fatal. The development of efficient and safe drugs is a critical unmet need. Acanthamoeba sterol 14α-demethylase (CYP51) is an essential enzyme of the sterol biosynthetic pathway. Repurposing antifungal azoles for amoebic infections has been reported, but their inhibitory effects on Acanthamoeba CYP51 enzymatic activity have not been studied. Here, we report catalytic properties, inhibition, and structural characterization of CYP51 from Acanthamoeba castellanii. The enzyme displays a 100-fold substrate preference for obtusifoliol over lanosterol, supporting the plant-like cycloartenol-based pathway in the pathogen. The strongest inhibition was observed with voriconazole (1 h IC50 0.45 μM), VT1598 (0.25 μM), and VT1161 (0.20 μM). The crystal structures of A. castellanii CYP51 with bound VT1161 (2.24 Å) and without an inhibitor (1.95 Å), presented here, can be used in the development of azole-based scaffolds to achieve optimal amoebicidal effectiveness.
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Affiliation(s)
- Tatiana
Y. Hargrove
- Department
of Biochemistry, Vanderbilt University School
of Medicine, Nashville, Tennessee 37232, United States
| | - David C. Lamb
- Faculty
of Medicine, Health and Life Science, Swansea
University, Swansea SA2 8PP, U.K.
| | - Zdzislaw Wawrzak
- Synchrotron
Research Center, Life Science Collaborative Access Team, Northwestern University, Argonne, Illinois 60439, United States
| | - Marcus Hull
- Faculty
of Medicine, Health and Life Science, Swansea
University, Swansea SA2 8PP, U.K.
| | - Steven L. Kelly
- Faculty
of Medicine, Health and Life Science, Swansea
University, Swansea SA2 8PP, U.K.
| | - F. Peter Guengerich
- Department
of Biochemistry, Vanderbilt University School
of Medicine, Nashville, Tennessee 37232, United States
| | - Galina I. Lepesheva
- Department
of Biochemistry, Vanderbilt University School
of Medicine, Nashville, Tennessee 37232, United States
- Vanderbilt
Institute of Chemical Biology, Nashville, Tennessee 37232, United States
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37232, United States
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9
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Kofoed VC, Campion C, Rasmussen PU, Møller SA, Eskildsen M, Nielsen JL, Madsen AM. Exposure to resistant fungi across working environments and time. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 923:171189. [PMID: 38447726 DOI: 10.1016/j.scitotenv.2024.171189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 02/19/2024] [Accepted: 02/21/2024] [Indexed: 03/08/2024]
Abstract
Antifungal resistance has emerged as a significant health concern with increasing reports of resistant variants in previously susceptible species. At present, little is known about occupational exposure to antifungal-resistant fungi. This study aimed to investigate Danish workers' occupational exposure to airborne fungi resistant to first-line treatment drugs. A retrospective study was performed on a unique collection of personal exposure samples gathered over a twenty-year period from Danish working environments, in sectors including agriculture, animal handling, waste management, and healthcare. A total of 669 samples were cultivated at 37 °C and fungal colonies were identified using MALDI-TOF MS. Subsequently, identification was confirmed by amplicon sequencing the genes of calmodulin and beta-tubulin to unveil potential cryptic species. Infectious fungi (495 isolates from 23 species) were tested for resistance against Itraconazole, Voriconazole, Posaconazole, and Amphotericin B. Working environments were highly variable in the overall fungal exposure, and showed vastly different species compositions. Resistance was found in 30 isolates of the species Aspergillus fumigatus (4 of 251 isolates), A. nidulans (2 of 13), A. niger complex (19 of 131), A. versicolor (3 of 18), and A. lentulus (2 of 2). Sequence analysis revealed several cryptic species within the A. niger complex including A. tubingensis, A. luchuensis, and A. phoenicis. Among the resistant A. fumigatus isolates, two contained the well-described TR34/L98H mutation in the cyp51A gene and promoter region, while the remainder harbored silent mutations. The results indicate that the working environment significantly contributes to exposure to resistant fungi, with particularly biofuel plant workers experiencing high exposure. Differences in the prevalence of resistance across working environments may be linked to the underlying species composition.
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Affiliation(s)
- Victor Carp Kofoed
- National Research Centre for the Working Environment, Lersø Parkallé 105, 2100 Copenhagen Ø, Denmark
| | - Christopher Campion
- National Research Centre for the Working Environment, Lersø Parkallé 105, 2100 Copenhagen Ø, Denmark
| | - Pil Uthaug Rasmussen
- National Research Centre for the Working Environment, Lersø Parkallé 105, 2100 Copenhagen Ø, Denmark
| | - Signe Agnete Møller
- National Research Centre for the Working Environment, Lersø Parkallé 105, 2100 Copenhagen Ø, Denmark; Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg Ø, Denmark
| | - Mathias Eskildsen
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg Ø, Denmark
| | - Jeppe Lund Nielsen
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg Ø, Denmark
| | - Anne Mette Madsen
- National Research Centre for the Working Environment, Lersø Parkallé 105, 2100 Copenhagen Ø, Denmark.
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10
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Lucio J, Alcazar-Fuoli L, Gil H, Cano-Pascual S, Hernandez-Egido S, Cuetara MS, Mellado E. Distribution of Aspergillus species and prevalence of azole resistance in clinical and environmental samples from a Spanish hospital during a three-year study period. Mycoses 2024; 67:e13719. [PMID: 38551063 DOI: 10.1111/myc.13719] [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: 10/24/2023] [Revised: 03/05/2024] [Accepted: 03/17/2024] [Indexed: 04/02/2024]
Abstract
BACKGROUND Surveillance studies are crucial for updating trends in Aspergillus species and antifungal susceptibility information. OBJECTIVES Determine the Aspergillus species distribution and azole resistance prevalence during this 3-year prospective surveillance study in a Spanish hospital. MATERIALS AND METHODS Three hundred thirty-five Aspergillus spp. clinical and environmental isolates were collected during a 3-year study. All isolates were screened for azole resistance using an agar-based screening method and resistance was confirmed by EUCAST antifungal susceptibility testing. The azole resistance mechanism was confirmed by sequencing the cyp51A gene and its promoter. All Aspergillus fumigatus strains were genotyped using TRESPERG analysis. RESULTS Aspergillus fumigatus was the predominant species recovered with a total of 174 strains (51.94%). The rest of Aspergillus spp. were less frequent: Aspergillus niger (14.93%), Aspergillus terreus (9.55%), Aspergillus flavus (8.36%), Aspergillus nidulans (5.37%) and Aspergillus lentulus (3.28%), among other Aspergillus species (6.57%). TRESPERG analysis showed 99 different genotypes, with 72.73% of the strains being represented as a single genotype. Some genotypes were common among clinical and environmental A. fumigatus azole-susceptible strains, even when isolated months apart. We describe the occurrence of two azole-resistant A. fumigatus strains, one clinical and another environmental, that were genotypically different and did not share genotypes with any of the azole-susceptible strains. CONCLUSIONS Aspergillus fumigatus strains showed a very diverse population although several genotypes were shared among clinical and environmental strains. The isolation of azole-resistant strains from both settings suggest that an efficient analysis of clinical and environmental sources must be done to detect azole resistance in A. fumigatus.
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Affiliation(s)
- Jose Lucio
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
| | - Laura Alcazar-Fuoli
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
- Center for Biomedical Research in Network in Infectious Diseases (CIBERINFEC-CB21/13/00105), Instituto de Salud Carlos III, Madrid, Spain
| | - Horacio Gil
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
| | - Samuel Cano-Pascual
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
| | - Sara Hernandez-Egido
- Microbiology Department, University Hospital Severo Ochoa, Leganés, Madrid, Spain
| | | | - Emilia Mellado
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
- Center for Biomedical Research in Network in Infectious Diseases (CIBERINFEC-CB21/13/00105), Instituto de Salud Carlos III, Madrid, Spain
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11
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Pontes L, Arai T, Gualtieri Beraquet CA, Giordano ALPL, Reichert-Lima F, da Luz EA, Fernanda de Sá C, Ortolan Levy L, Tararam CA, Watanabe A, Moretti ML, Zaninelli Schreiber A. Uncovering a Novel cyp51A Mutation and Antifungal Resistance in Aspergillus fumigatus through Culture Collection Screening. J Fungi (Basel) 2024; 10:122. [PMID: 38392794 PMCID: PMC10890095 DOI: 10.3390/jof10020122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 01/23/2024] [Accepted: 01/30/2024] [Indexed: 02/24/2024] Open
Abstract
BACKGROUND Aspergillus fumigatus is an important concern for immunocompromised individuals, often resulting in severe infections. With the emergence of resistance to azoles, which has been the therapeutic choice for Aspergillus infections, monitoring the resistance of these microorganisms becomes important, including the search for mutations in the cyp51A gene, which is the gene responsible for the mechanism of action of azoles. We conducted a retrospective analysis covering 478 A. fumigatus isolates. METHODS This comprehensive dataset comprised 415 clinical isolates and 63 isolates from hospital environmental sources. For clinical isolates, they were evaluated in two different periods, from 1998 to 2004 and 2014 to 2021; for environmental strains, one strain was isolated in 1998, and 62 isolates were evaluated in 2015. Our primary objectives were to assess the epidemiological antifungal susceptibility profile; trace the evolution of resistance to azoles, Amphotericin B (AMB), and echinocandins; and monitor cyp51A mutations in resistant strains. We utilized the broth microdilution assay for susceptibility testing, coupled with cyp51A gene sequencing and microsatellite genotyping to evaluate genetic variability among resistant strains. RESULTS Our findings reveal a progressive increase in Minimum Inhibitory Concentrations (MICs) for azoles and AMB over time. Notably, a discernible trend in cyp51A gene mutations emerged in clinical isolates starting in 2014. Moreover, our study marks a significant discovery as we detected, for the first time, an A. fumigatus isolate carrying the recently identified TR46/F495I mutation within a sample obtained from a hospital environment. The observed cyp51A mutations underscore the ongoing necessity for surveillance, particularly as MICs for various antifungal classes continue to rise. CONCLUSIONS By conducting resistance surveillance within our institution's culture collection, we successfully identified a novel TR46/F495I mutation in an isolate retrieved from the hospital environment which had been preserved since 1998. Moreover, clinical isolates were found to exhibit TR34/L98H/S297T/F495I mutations. In addition, we observed an increase in MIC patterns for Amphotericin B and azoles, signaling a change in the resistance pattern, emphasizing the urgent need for the development of new antifungal drugs. Our study highlights the importance of continued monitoring and research in understanding the evolving challenges in managing A. fumigatus infections.
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Affiliation(s)
- Laís Pontes
- School of Medical Sciences, University of Campinas, Campinas 13083-970, São Paulo, Brazil
| | - Teppei Arai
- Division of Clinical Research, Medical Mycology Research Center, Chiba University, Chiba 260-8670, Japan
| | | | | | - Franqueline Reichert-Lima
- Department of Medicine, School of Medical Sciences in São José dos Campos-Humanitas, São José dos Campos 12220-061, São Paulo, Brazil
| | - Edson Aparecido da Luz
- Division of Clinical Pathology, Microbiology Laboratory, University of Campinas Clinical Hospital, Campinas 13083-888, São Paulo, Brazil
| | - Camila Fernanda de Sá
- Division of Clinical Pathology, Microbiology Laboratory, University of Campinas Clinical Hospital, Campinas 13083-888, São Paulo, Brazil
| | - Larissa Ortolan Levy
- School of Medical Sciences, University of Campinas, Campinas 13083-970, São Paulo, Brazil
| | | | - Akira Watanabe
- Division of Clinical Research, Medical Mycology Research Center, Chiba University, Chiba 260-8670, Japan
| | - Maria Luiza Moretti
- School of Medical Sciences, University of Campinas, Campinas 13083-970, São Paulo, Brazil
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12
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Heaven T, Armitage AD, Xu X, Goddard MR, Cockerton HM. Dose-Dependent Genetic Resistance to Azole Fungicides Found in the Apple Scab Pathogen. J Fungi (Basel) 2023; 9:1136. [PMID: 38132737 PMCID: PMC10744243 DOI: 10.3390/jof9121136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 11/13/2023] [Accepted: 11/17/2023] [Indexed: 12/23/2023] Open
Abstract
The evolution of azole resistance in fungal pathogens presents a major challenge in both crop production and human health. Apple orchards across the world are faced with the emergence of azole fungicide resistance in the apple scab pathogen Venturia inaequalis. Target site point mutations observed in this fungus to date cannot fully explain the reduction in sensitivity to azole fungicides. Here, polygenic resistance to tebuconazole was studied across a population of V. inaequalis. Genotyping by sequencing allowed Quantitative Trait Loci (QTLs) mapping to identify the genetic components controlling this fungicide resistance. Dose-dependent genetic resistance was identified, with distinct genetic components contributing to fungicide resistance at different exposure levels. A QTL within linkage group seven explained 65% of the variation in the effective dose required to reduce growth by 50% (ED50). This locus was also involved in resistance at lower fungicide doses (ED10). A second QTL in linkage group one was associated with dose-dependent resistance, explaining 34% of variation at low fungicide doses (ED10), but did not contribute to resistance at higher doses (ED50 and ED90). Within QTL regions, non-synonymous mutations were observed in several ATP-Binding Cassette and Major Facilitator SuperFamily transporter genes. These findings provide insight into the mechanisms of fungicide resistance that have evolved in horticultural pathogens. Identification of resistance gene candidates supports the development of molecular diagnostics to inform management practices.
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Affiliation(s)
- Thomas Heaven
- National Institute of Agricultural Botany, New Road, East Malling, West Malling, Kent ME19 6BJ, UK;
- The School of Life and Environmental Sciences, University of Lincoln, Lincoln LN6 7DL, UK;
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | | | - Xiangming Xu
- National Institute of Agricultural Botany, New Road, East Malling, West Malling, Kent ME19 6BJ, UK;
| | - Matthew R. Goddard
- The School of Life and Environmental Sciences, University of Lincoln, Lincoln LN6 7DL, UK;
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13
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Cao Y, Song X, Xu G, Zhang X, Yan H, Feng J, Ma Z, Liu X, Wang Y. Study on the Antifungal Activity and Potential Mechanism of Natamycin against Colletotrichum fructicola. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:17713-17722. [PMID: 37943656 DOI: 10.1021/acs.jafc.3c05154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
In this investigation, the antifungal activity, its influence on the quality of apples, and the molecular mechanism of natamycin against Colletotrichum fructicola were systematically explored. Our findings indicated that natamycin showed significant inhibition against C. fructicola. Moreover, it efficaciously maintained the apple quality by modulating the physicochemical index. Research on the antifungal mechanism showed that natamycin altered the mycelial microstructure, disrupted the plasma membrane integrality, and decreased the ergosterol content of C. fructicola. Interestingly, the exogenous addition of ergosterol weakened the antifungal activity of natamycin. Importantly, natamycin markedly inhibited the expression of Cyp51A and Cyp51B genes in C. fructicola, which was contrary to the results obtained after treatment with triazole fungicide flusilazole. All these results exhibited sufficient proof that natamycin had enormous potential to be conducive as a promising biopreservative against C. fructicola on apples, and these findings will advance our knowledge on the mechanism of natamycin against pathogenic fungi.
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Affiliation(s)
- Yuxuan Cao
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Xianyang, 712100 Shaanxi, China
| | - Xiaoning Song
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Xianyang, 712100 Shaanxi, China
| | - Guanyou Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Xianyang, 712100 Shaanxi, China
| | - Xu Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Xianyang, 712100 Shaanxi, China
| | - He Yan
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Xianyang, 712100 Shaanxi, China
- Provincial Center for Bio-Pesticide Engineering, Northwest A&F University, Yangling, Xianyang, 712100 Shaanxi, China
| | - Juntao Feng
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Xianyang, 712100 Shaanxi, China
- Provincial Center for Bio-Pesticide Engineering, Northwest A&F University, Yangling, Xianyang, 712100 Shaanxi, China
| | - Zhiqing Ma
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Xianyang, 712100 Shaanxi, China
- Provincial Center for Bio-Pesticide Engineering, Northwest A&F University, Yangling, Xianyang, 712100 Shaanxi, China
| | - Xili Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Xianyang, 712100 Shaanxi, China
| | - Yong Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Xianyang, 712100 Shaanxi, China
- Provincial Center for Bio-Pesticide Engineering, Northwest A&F University, Yangling, Xianyang, 712100 Shaanxi, China
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14
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Zeng M, Zhou X, Yang C, Liu Y, Zhang J, Xin C, Qin G, Liu F, Song Z. Comparative analysis of the biological characteristics and mechanisms of azole resistance of clinical Aspergillus fumigatus strains. Front Microbiol 2023; 14:1253197. [PMID: 38029222 PMCID: PMC10665732 DOI: 10.3389/fmicb.2023.1253197] [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: 07/05/2023] [Accepted: 10/27/2023] [Indexed: 12/01/2023] Open
Abstract
Aspergillus fumigatus is a common causative pathogen of aspergillosis. At present, triazole resistance of A. fumigatus poses an important challenge to human health globally. In this study, the biological characteristics and mechanisms of azole resistance of five A. fumigatus strains (AF1, AF2, AF4, AF5, and AF8) were explored. There were notable differences in the sporulation and biofilm formation abilities of the five test strains as compared to the standard strain AF293. The ability of strain AF1 to avoid phagocytosis by MH-S cells was significantly decreased as compared to strain AF293, while that of strains AF2, AF4, and AF5 were significantly increased. Fungal burden analysis with Galleria mellonella larvae revealed differences in pathogenicity among the five strains. Moreover, the broth microdilution and E-test assays confirmed that strains AF1 and AF2 were resistant to itraconazole and isaconazole, while strains AF4, AF5, and AF8 were resistant to voriconazole and isaconazole. Strains AF1 and AF2 carried the cyp51A mutations TR34/L98H/V242I/S297T/F495I combined with the hmg1 mutation S541G, whereas strains AF4 and AF8 carried the cyp51A mutation TR46/Y121F/V242I/T289A, while strain AF5 had no cyp51A mutation. Real-time quantitative polymerase chain reaction (RT-qPCR) analysis revealed differences in the expression levels of genes associated with ergosterol synthesis and efflux pumps among the five strains. In addition, transcriptomics, RT-qPCR, and the NAD+/NADH ratio demonstrated that the mechanism of voriconazole resistance of strain AF5 was related to overexpression of genes associated with energy production and efflux pumps. These findings will help to further elucidate the triazole resistance mechanism in A. fumigatus.
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Affiliation(s)
- Meng Zeng
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
- Department of Clinical Laboratory, Yongchuan Hospital of Chongqing Medical University, Chongqing, China
| | - Xue Zhou
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
| | - Chunhong Yang
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
| | - Yanfei Liu
- Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Jinping Zhang
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
| | - Caiyan Xin
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
| | - Gang Qin
- Department of Otolaryngology Head and Neck Surgery, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Fangyan Liu
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
| | - Zhangyong Song
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
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15
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Álvarez-Pérez S, García ME, Martínez-Nevado E, Blanco JL. Presence of Aspergillus fumigatus with the TR 34/L98H Cyp51A mutation and other azole-resistant aspergilli in the air of a zoological park. Res Vet Sci 2023; 164:104993. [PMID: 37657393 DOI: 10.1016/j.rvsc.2023.104993] [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: 04/14/2023] [Revised: 08/03/2023] [Accepted: 08/23/2023] [Indexed: 09/03/2023]
Abstract
Antifungal-resistant fungi, including Aspergillus fumigatus and other Aspergillus species, pose an urgent threat to human and animal health. Furthermore, the environmental route of azole resistance selection due to the widespread use of azole fungicides in crop protection and other applications is a major public health issue. Although environmental surveillance of fungi is frequently performed in many zoological parks and wildlife rehabilitation centers, the antifungal susceptibility of recovered isolates is only rarely analyzed, which precludes a clear assessment of the threat posed by these fungi to captive animals. In this study, we assessed the presence of airborne azole-resistant Aspergillus spp., including the so-called 'cryptic species' (i.e., species which are phenotypically similar to more well-known aspergilli but clearly constitute different phylogenetic lineages) in a zoological park located in the city of Madrid, Spain. In general, our results revealed a low prevalence A. fumigatus and cryptic aspergilli with decreased susceptibility to azoles. However, we detected an A. fumigatus isolate with the TR34/L98H mutation in the gene encoding the lanosterol 14α-demethylase (Cyp51A), consisting of a tandem repeat of 34 base pairs in the promoter region and a lysine to histidine substitution at codon 98. Notably, this TR34/L98H mutation has been linked to the environmental route of azole resistance selection, thus highlighting the 'One Health' dimension of the emerging problem of antifungal resistance. In this context, continuous environmental surveillance of azole-resistant aspergilli in zoological parks and other similar animal facilities is recommended.
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Affiliation(s)
- Sergio Álvarez-Pérez
- Department of Animal Health, Faculty of Veterinary Medicine, Complutense University of Madrid, Avenida Puerta de Hierro s/n, Madrid 28040, Spain.
| | - Marta E García
- Department of Animal Health, Faculty of Veterinary Medicine, Complutense University of Madrid, Avenida Puerta de Hierro s/n, Madrid 28040, Spain
| | | | - José L Blanco
- Department of Animal Health, Faculty of Veterinary Medicine, Complutense University of Madrid, Avenida Puerta de Hierro s/n, Madrid 28040, Spain
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16
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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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17
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De Francesco MA. Drug-Resistant Aspergillus spp.: A Literature Review of Its Resistance Mechanisms and Its Prevalence in Europe. Pathogens 2023; 12:1305. [PMID: 38003770 PMCID: PMC10674884 DOI: 10.3390/pathogens12111305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 10/28/2023] [Accepted: 10/30/2023] [Indexed: 11/26/2023] Open
Abstract
Infections due to the Aspergillus species constitute an important challenge for human health. Invasive aspergillosis represents a life-threatening disease, mostly in patients with immune defects. Drugs used for fungal infections comprise amphotericin B, triazoles, and echinocandins. However, in the last decade, an increased emergence of azole-resistant Aspergillus strains has been reported, principally belonging to Aspergillus fumigatus species. Therefore, both the early diagnosis of aspergillosis and its epidemiological surveillance are very important to establish the correct antifungal therapy and to ensure a successful patient outcome. In this paper, a literature review is performed to analyze the prevalence of Aspergillus antifungal resistance in European countries. Amphotericin B resistance is observed in 2.6% and 10.8% of Aspergillus fumigatus isolates in Denmark and Greece, respectively. A prevalence of 84% of amphotericin B-resistant Aspergillus flavus isolates is reported in France, followed by 49.4%, 35.1%, 21.7%, and 20% in Spain, Portugal, Greece, and amphotericin B resistance of Aspergillus niger isolates is observed in Greece and Belgium with a prevalence of 75% and 12.8%, respectively. The prevalence of triazole resistance of Aspergillus fumigatus isolates, the most studied mold obtained from the included studies, is 0.3% in Austria, 1% in Greece, 1.2% in Switzerland, 2.1% in France, 3.9% in Portugal, 4.9% in Italy, 5.3% in Germany, 6.1% in Denmark, 7.4% in Spain, 8.3% in Belgium, 11% in the Netherlands, and 13.2% in the United Kingdom. The mechanism of resistance is mainly driven by the TR34/L98H mutation. In Europe, no in vivo resistance is reported for echinocandins. Future studies are needed to implement the knowledge on the spread of drug-resistant Aspergillus spp. with the aim of defining optimal treatment strategies.
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Affiliation(s)
- Maria Antonia De Francesco
- Department of Molecular and Translational Medicine, Institute of Microbiology, University of Brescia, ASST Spedali Civili, 25123 Brescia, Italy
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18
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Hu S, Yan C, Yu H, Zhang Y, Zhang CQ. Establishment of the Recombinase Polymerase Amplification-Lateral Flow Dipstick Detection Technique for Fusarium oxysporum. PLANT DISEASE 2023; 107:2665-2672. [PMID: 36774580 DOI: 10.1094/pdis-12-22-2841-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Fusarium oxysporum causes crown rot, wilt, root rot, and many other major plant diseases worldwide. During the progression of strawberry crown rot disease, the pathogen is transmitted from the mother plant to the seedling through the stolon, with obvious characteristics of latent infection. Therefore, rapid and timely detection of F. oxysporum is important for efficient disease management. In this study, a recombinase polymerase amplification-lateral flow dipstick (RPA-LFD) detection technique was developed for the rapid detection of F. oxysporum on strawberry plants by targeting the CYP51C gene, which is unique to Fusarium spp. Because this RPA-LFD detection technique was highly specific to F. oxysporum, other Fusarium and non-Fusarium fungi were not detected. The optimal reaction temperature and time for this technique were 39°C and 8 min, respectively. The detection limit was 1 pg of F. oxysporum genomic DNA in a 50-μl reaction system. A total of 46 strawberry plants with or without crown rot symptoms collected from Jiande, Changxing, and Haining in Zhejiang Province were further assessed for F. oxysporum infection using both RPA-LFD and traditional tissue isolation techniques. The RPA-LFD test showed that 32 of the 46 strawberry plants tested were positive for F. oxysporum, while in the traditional isolation technique, F. oxysporum was isolated from 30 of the 46 strawberry plants. These results suggest that our established RPA-LFD method is rapid, sensitive, and highly specific in detecting F. oxysporum infection in strawberry plants.
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Affiliation(s)
- Shuodan Hu
- Department of Plant Pathology, Zhejiang Agriculture and Forest University, Hangzhou 311300, China
| | - Chenyi Yan
- Department of Plant Pathology, Zhejiang Agriculture and Forest University, Hangzhou 311300, China
| | - Hong Yu
- Research Institute for the Agriculture Science of Hangzhou, Hangzhou 310013, China
| | - Yu Zhang
- Department of Plant Pathology, Zhejiang Agriculture and Forest University, Hangzhou 311300, China
| | - Chuan-Qing Zhang
- Department of Plant Pathology, Zhejiang Agriculture and Forest University, Hangzhou 311300, China
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He D, Shi J, Qiu J, Hou Y, Du Y, Gao T, Huang W, Wu J, Lee YW, Mohamed SR, Liu X, Xu J. Antifungal activities of a novel triazole fungicide, mefentrifluconazole, against the major maize pathogen Fusarium verticillioides. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 192:105398. [PMID: 37105621 DOI: 10.1016/j.pestbp.2023.105398] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/17/2023] [Accepted: 03/19/2023] [Indexed: 06/19/2023]
Abstract
Fusarium ear rot (FER) is a serious fungal disease occurring the late growth stage of maize. FER not only reduces the yield of maize but also causes mycotoxin contamination, which affects the quality of maize and threatens human and animal health. Fusarium verticillioides is the predominant causative pathogen of FER worldwide. At present, there is no registered fungicide for use against maize FER in China. The novel isopropyl alcohol-triazole fungicide mefentrifluconazole (MFZ) has been shown to be effective against several Fusarium spp., but little is known about its specific activity against F. verticillioides. MFZ exhibited strong antifungal activities against 50 strains of F. verticillioides collected from the major maize-growing areas in China. MFZ inhibited mycelial growth, conidium production, germination and germ tube elongation of F. verticillioides. MFZ treatment significantly reduced fumonisin production and the expression levels of fumonisin biosynthetic genes. Genome-wide transcriptional profiling of F. verticillioides in response to MFZ indicated that the expression of genes involved in ergosterol biosynthesis, including fungicide target genes (cyp51 genes), was significantly downregulated by MFZ. MFZ treatment resulted in reduced ergosterol production and increased glycerol and malonaldehyde production as well as relative conductivity in F. verticillioides. A 2-year field experiment showed a significant reduction in FER severity in maize after spraying with MFZ at the tasseling stage. This study evaluated the potential of MFZ to control FER in maize and provides insights into its antifungal activities and mechanism of action against F. verticillioides.
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Affiliation(s)
- Dan He
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Key Laboratory for Agro-product Safety Risk Evaluation (Nanjing), Ministry of Agriculture and Rural Affairs/Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, Jiangsu, PR China; College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, Jiangsu, PR China
| | - Jianrong Shi
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Key Laboratory for Agro-product Safety Risk Evaluation (Nanjing), Ministry of Agriculture and Rural Affairs/Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, Jiangsu, PR China; School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China
| | - Jianbo Qiu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Key Laboratory for Agro-product Safety Risk Evaluation (Nanjing), Ministry of Agriculture and Rural Affairs/Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, Jiangsu, PR China; School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China
| | - Yiping Hou
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, Jiangsu, PR China
| | - Yuzhou Du
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, Jiangsu, PR China
| | - Tao Gao
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Key Laboratory for Agro-product Safety Risk Evaluation (Nanjing), Ministry of Agriculture and Rural Affairs/Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, Jiangsu, PR China
| | - Wenwen Huang
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Key Laboratory for Agro-product Safety Risk Evaluation (Nanjing), Ministry of Agriculture and Rural Affairs/Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, Jiangsu, PR China; School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China
| | - Jiawen Wu
- Jiangsu Plant Protection and Plant Quarantine Station, Nanjing 210036, Jiangsu, PR China
| | - Yin-Won Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, South Korea
| | - Sherif Ramzy Mohamed
- Food Toxicology and Contaminants Department, National Research Centre, Egypt, Giza 12411, Egypt
| | - Xin Liu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Key Laboratory for Agro-product Safety Risk Evaluation (Nanjing), Ministry of Agriculture and Rural Affairs/Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, Jiangsu, PR China; School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China.
| | - Jianhong Xu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Key Laboratory for Agro-product Safety Risk Evaluation (Nanjing), Ministry of Agriculture and Rural Affairs/Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, Jiangsu, PR China; School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China.
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20
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Mao CX, Luo J, Zhang Y, Zhang CQ. Targeted deletion of three CYP51s in Fusarium fujikuroi and their different roles in determining sensitivity to 14α-demethylase inhibitor fungicides. PEST MANAGEMENT SCIENCE 2023; 79:1324-1330. [PMID: 36424479 DOI: 10.1002/ps.7304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 11/01/2022] [Accepted: 11/25/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND Fusarium fujikuroi is the pathogenic agent of rice bakanae disease and has developed serious resistance to prochloraz, a 14α-demethylase inhibitor (DMI). Prochloraz resistance in F. fujikuroi is caused by cooperation between FfCyp51B with Cyp51A and shows cross-resistance only to prothioconazole but not to tebuconazole, difenoconazole, propiconazole, metconazole, hexaconazole, and triadimefon. This study aimed to analyze the functions of the three Cyp51s in F. fujikuroi, especially their role in determining sensitivity to DMIs. RESULTS The respective deletion of FfCyp51A, Cyp51B, and Cyp51C had no obvious effect on morphology, conidium germination, or pathogenicity. The involvement of growth, growth and ergosterol biosynthesis, and conidium production and ergosterol biosynthesis was observed for FfCyp51A, Cyp51B, and Cyp51C, respectively. Compared with the sensitive isolate of F. fujikuroi, the effect on sensitivity to the tested DMIs was divided into four groups: (i) both of Cyp51A and Cyp51B positively regulate the sensitivity to prochloraz and prothioconazole; (ii) Cyp51B positively regulate the sensitivity to tebuconazole and metconazole, but negatively regulate the sensitivity to difenoconazole; (iii) Cyp51A and Cyp51B play opposite roles in the sensitivity to triadimefon. Therefore, deletion of Cyp51A in F. fujikuroi confers a higher sensitivity to triadimefon, while deletion of Cyp51B results in a triadimefon-resistant mutant isolate; (iv) deletion of Cyp51B yielded a mutant isolate that was more resistant to propiconazole and hexaconazole. CONCLUSION Sophisticated interactions exist within the three Cyp51 genes to DMIs fungicides sensitivity in F. fujikuroi, and Cyp51B probably plays a more critical role than Cyp51A and Cyp51C. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Cheng-Xin Mao
- Department of Crop Protection, Zhejiang Agriculture and Forest University, Hangzhou, China
| | - Ju Luo
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Yu Zhang
- Department of Crop Protection, Zhejiang Agriculture and Forest University, Hangzhou, China
| | - Chuan-Qing Zhang
- Department of Crop Protection, Zhejiang Agriculture and Forest University, Hangzhou, China
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21
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Li F, Ebihara A, Sakahara Y, Matsumoto S, Ueno R, Bao W, Kimura M, Fuji SI, Shimizu M, Kageyama K, Suga H. Synergistic effect of amino acid substitutions in CYP51B for prochloraz resistance in Fusarium fujikuroi. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 189:105291. [PMID: 36549812 DOI: 10.1016/j.pestbp.2022.105291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/08/2022] [Accepted: 11/10/2022] [Indexed: 06/17/2023]
Abstract
Prochloraz has been used to control Fusarium fujikuroi, the causative pathogen of rice bakanae disease. Linkage analysis of FfCYP51 genes in the progenies obtained from crossing prochloraz moderately resistant and sensitive strains suggested that the FfCYP51B gene is involved in prochloraz resistance. Sequence comparison revealed that the prochloraz-resistant strain had an F511S or S312T/F511S substitution in FfCYP51B compared with the sensitive strains. The contribution of the S312T and F511S substitutions in FfCYP51B to prochloraz resistance was investigated by creating S/F-, T/F-, or T/S- types at 312/511 codons from the S/S-type, which is a natural moderately resistant strain, using a gene-editing technique. T/S exhibited the highest prochloraz resistance, followed by S/S-, T/F-, and S/F-types. These results indicated that the S312T and F511S substitutions in FfCYP51B had a synergistic effect on prochloraz resistance in F. fujikuroi.
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Affiliation(s)
- FangJing Li
- The United Graduate School of Agricultural Science, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan
| | - Akio Ebihara
- Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan
| | - Yuri Sakahara
- Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan
| | - Sarara Matsumoto
- Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan
| | - Reina Ueno
- Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan
| | - WanXue Bao
- Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan
| | - Makoto Kimura
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Shin-Ichi Fuji
- Faculty of Bioresource Sciences, Akita Prefectural University, 241-438 Kaidobata-Nishi Nakano Shimoshinjo, Akita 010-0195, Japan
| | - Masafumi Shimizu
- Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan
| | - Koji Kageyama
- River Basin Research Center, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan
| | - Haruhisa Suga
- Institute for Glyco-core Research (iGCORE), Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan..
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22
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Biochemical Identification of a Nuclear Coactivator Protein Required for AtrR-Dependent Gene Regulation in Aspergillus fumigatus. mSphere 2022; 7:e0047622. [PMID: 36374043 PMCID: PMC9769526 DOI: 10.1128/msphere.00476-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Azole drugs represent the primary means of treating infections associated with the filamentous fungal pathogen Aspergillus fumigatus. A central player in azole resistance is the Zn2Cys6 zinc cluster-containing transcription factor AtrR. This factor stimulates expression of both the cyp51A gene, which encodes the azole drug target enzyme, as well as an ATP-binding cassette transporter-encoding gene called abcG1 (cdr1B). We used a fusion protein between AtrR and the tandem affinity purification (TAP) moiety to purify proteins that associated with AtrR from A. fumigatus. Protein fractions associated with AtrR-TAP were subjected to multidimensional protein identification technology mass spectrometry, and one of the proteins identified was encoded by the AFUA_6g08010 gene. We have designated this protein NcaA (for nuclear coactivator of AtrR). Loss of ncaA caused a reduction in voriconazole resistance and drug-induced abcG1 expression, although it did not impact induction of cyp51A transcription. We confirmed the association of AtrR and NcaA by coimmunoprecipitation from otherwise-wild-type cells. Expression of fusion proteins between AtrR and NcaA with green fluorescent protein allowed determination that these two proteins were localized in the A. fumigatus nucleus. Together, these data support the view that NcaA is required for nuclear gene transcription controlled by AtrR. IMPORTANCE Aspergillus fumigatus is a major filamentous fungal pathogen in humans and is susceptible to the azole antifungal class of drugs. However, loss of azole susceptibility has been detected with increasing frequency in the clinic, and infections associated with these azole-resistant isolates have been linked to treatment failure and worse outcomes. Many of these azole-resistant strains contain mutant alleles of the cyp51A gene, which encodes the azole drug target. A transcription factor essential for cyp51A gene transcription has been identified and designated AtrR. AtrR is required for azole-inducible cyp51A transcription, but we know little of the regulation of this transcription factor. Using a biochemical approach, we identified a new protein called NcaA that is involved in regulation of AtrR at certain target gene promoters. Understanding the mechanisms controlling AtrR function is an important goal in preventing or reversing azole resistance in this pathogen.
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James JE, Santhanam J, Cannon RD, Lamping E. Voriconazole Treatment Induces a Conserved Sterol/Pleiotropic Drug Resistance Regulatory Network, including an Alternative Ergosterol Biosynthesis Pathway, in the Clinically Important FSSC Species, Fusarium keratoplasticum. J Fungi (Basel) 2022; 8:jof8101070. [PMID: 36294635 PMCID: PMC9605146 DOI: 10.3390/jof8101070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/09/2022] [Accepted: 10/10/2022] [Indexed: 11/16/2022] Open
Abstract
Fusarium keratoplasticum is the Fusarium species most commonly associated with human infections (fusariosis). Antifungal treatment of fusariosis is often hampered by limited treatment options due to resistance towards azole antifungals. The mechanisms of antifungal resistance and sterol biosynthesis in fusaria are poorly understood. Therefore, in this study we assessed the transcriptional response of F. keratoplasticum when exposed to voriconazole. Our results revealed a group of dramatically upregulated ergosterol biosynthesis gene duplicates, most notably erg6A (912-fold), cyp51A (52-fold) and ebp1 (20-fold), which are likely part of an alternative ergosterol biosynthesis salvage pathway. The presence of human cholesterol biosynthesis gene homologs in F. keratoplasticum (ebp1, dhcr7 and dhcr24_1, dhcr24_2 and dhcr24_3) suggests that additional sterol biosynthesis pathways may be induced in fusaria under other growth conditions or during host invasion. Voriconazole also induced the expression of a number of ABC efflux pumps. Further investigations suggested that the highly conserved master regulator of ergosterol biosynthesis, FkSR, and the pleiotropic drug resistance network that induces zinc-cluster transcription factor FkAtrR coordinate the response of FSSC species to azole antifungal exposure. In-depth genome mining also helped clarify the ergosterol biosynthesis pathways of moulds and provided a better understanding of antifungal drug resistance mechanisms in fusaria.
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Affiliation(s)
- Jasper E. James
- Biomedical Science Programme, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9016, New Zealand
| | - Jacinta Santhanam
- Biomedical Science Programme, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia
- Correspondence: (J.S.); (R.D.C.); (E.L.); Tel.: +60-3-9289-7039 (J.S.); +64-3-479-7081 (R.D.C.); +64-3-479-5290 (E.L.)
| | - Richard D. Cannon
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9016, New Zealand
- Correspondence: (J.S.); (R.D.C.); (E.L.); Tel.: +60-3-9289-7039 (J.S.); +64-3-479-7081 (R.D.C.); +64-3-479-5290 (E.L.)
| | - Erwin Lamping
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9016, New Zealand
- Correspondence: (J.S.); (R.D.C.); (E.L.); Tel.: +60-3-9289-7039 (J.S.); +64-3-479-7081 (R.D.C.); +64-3-479-5290 (E.L.)
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The Transcription Factor CsAtf1 Negatively Regulates the Cytochrome P450 Gene CsCyp51G1 to Increase Fludioxonil Sensitivity in Colletotrichum siamense. J Fungi (Basel) 2022; 8:jof8101032. [PMID: 36294597 PMCID: PMC9605597 DOI: 10.3390/jof8101032] [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: 09/12/2022] [Revised: 09/26/2022] [Accepted: 09/26/2022] [Indexed: 11/30/2022] Open
Abstract
Previous studies have shown that the high-osmolarity glycerol mitogen-activated protein kinase (HOG MAPK) signaling pathway and its downstream transcription factor CsAtf1 are involved in the regulation of fludioxonil sensitivity in C. siamense. However, the downstream target genes of CsAtf1 related to the fludioxonil stress response remain unclear. Here, we performed chromatin immunoprecipitation sequencing (ChIP-Seq) and high-throughput RNA-sequencing (RNA-Seq) to identify genome-wide potential CsAtf1 target genes. A total of 3809 significantly differentially expressed genes were predicted to be directly regulated by CsAtf1, including 24 cytochrome oxidase-related genes. Among them, a cytochrome P450-encoding gene, designated CsCyp51G1, was confirmed to be a target gene, and its transcriptional expression was negatively regulated by CsAtf1, as determined using an electrophoretic mobility shift assay (EMSA), a yeast one-hybrid (Y1H) assay, and quantitative real-time PCR (qRT-PCR). Moreover, the overexpression mutant CsCYP51G1 of C. siamense exhibited increased fludioxonil tolerance, and the CsCYP51G1 deletion mutant exhibited decreased fludioxonil resistance, which revealed that CsCyp51G1 is involved in fludioxonil sensitivity regulation in C. siamense. However, the cellular ergosterol content of the mutants was not consistent with the phenotype of fludioxonil sensitivity, which indicated that CsCyp51G1 regulates fludioxonil sensitivity by affecting factors other than the ergosterol level in C. siamense. In conclusion, our data indicate that the transcription factor CsAtf1 negatively regulates the cytochrome P450 gene CsCyp51G1 to increase fludioxonil sensitivity in C. siamense.
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James JE, Santhanam J, Zakaria L, Mamat Rusli N, Abu Bakar M, Suetrong S, Sakayaroj J, Abdul Razak MF, Lamping E, Cannon RD. Morphology, Phenotype, and Molecular Identification of Clinical and Environmental Fusarium solani Species Complex Isolates from Malaysia. J Fungi (Basel) 2022; 8:jof8080845. [PMID: 36012833 PMCID: PMC9409803 DOI: 10.3390/jof8080845] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 06/28/2022] [Accepted: 07/06/2022] [Indexed: 01/18/2023] Open
Abstract
Fusarium infections in humans (fusariosis) and in economically important plants involve species of several Fusarium species complexes. Species of the Fusarium solani species complex (FSSC) are the most frequent cause of human fusariosis. The FSSC comprises more than 60 closely related species that can be separated into three major clades by multi-locus sequence typing (MLST) using translation elongation factor 1-alpha (TEF1-α) and RNA polymerase II (RPB2) DNA sequences. The MLST nomenclature for clade 3 of the FSSC assigns numbers to species types (e.g., FSSC 2) and lowercase letters to identify unique haplotypes. The aim of this study was to analyse the genotypic and phenotypic characteristics of 15 environmental and 15 clinical FSSC isolates from Malaysia. MLST was used for the genotypic characterisation of FSSC isolates from various locations within Malaysia, which was complemented by their morphological characterisation on potato dextrose and carnation leaf agar. MLST identified eight different FSSC species: thirteen Fusarium keratoplasticum (i.e., FSSC 2), six Fusarium suttonianum (FSSC 20), five Fusarium falciforme (FSSC 3+4), two Fusarium cyanescens (FSSC 27), and one each of Fusarium petroliphilum (FSSC 1), Fusarium waltergamsii (FSSC 7), Fusarium sp. (FSSC 12), and Fusarium striatum (FSSC 21). Consistent with previous reports from Malaysia, most (11 of 15) clinical FSSC isolates were F. keratoplasticum and the majority (9 of 15) of environmental isolates were F. suttonianum (5) or F. falciforme (4) strains. The taxonomic relationships of the isolates were resolved phylogenetically. The eight Fusarium species also showed distinct morphological characteristics, but these were less clearly defined and reached across species boundaries. Although TEF1-α and RPB2 sequences were sufficient for the species identification of most FSSC isolates, a more precise MLST scheme needs to be established to reliably assign individual isolates of the species-rich FSSC to their geographically-, epidemiologically-, and host-associated sub-lineages.
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Affiliation(s)
- Jasper E. James
- Biomedical Science Programme, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia
| | - Jacinta Santhanam
- Biomedical Science Programme, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia
- Correspondence: ; Tel.: +603-9289-7039
| | - Latiffah Zakaria
- School of Biological Sciences, Universiti Sains Malaysia, Gelugor 11800, Malaysia
| | - Nuraini Mamat Rusli
- Biomedical Science Programme, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia
| | - Mariahyati Abu Bakar
- Biomedical Science Programme, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia
| | - Satinee Suetrong
- National Center for Genetic Engineering and Biotechnology (BIOTEC), Thailand Science Park, Pathum Thani 12120, Thailand
| | - Jariya Sakayaroj
- School of Science, Wailalak University, Nakhonsithammarat 80161, Thailand
| | - Mohd Fuat Abdul Razak
- Bacteriology Unit, Institute for Medical Research, National Institute of Health, Shah Alam 40170, Malaysia
| | - Erwin Lamping
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9016, New Zealand
| | - Richard D. Cannon
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9016, New Zealand
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Yang G, Cui S, Ma N, Song Y, Ma J, Huang W, Zhang Y, Xu J. Genetic Structure and Triazole Antifungal Susceptibilities of Alternaria alternata from Greenhouses in Kunming, China. Microbiol Spectr 2022; 10:e0038222. [PMID: 35546576 PMCID: PMC9241833 DOI: 10.1128/spectrum.00382-22] [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: 01/29/2022] [Accepted: 04/22/2022] [Indexed: 11/20/2022] Open
Abstract
Alternaria alternata is an opportunistic human fungal pathogen and a ubiquitous phytopathogen capable of causing diseases to >100 agricultural crops and ornamental plants. To control plant diseases caused by A. alternata, triazole fungicides have been widely used both in open crop and vegetable fields and in indoor growth facilities such as greenhouses. At present, the effect of fungicide use on triazole resistance development in A. alternata populations is not known. Here, we isolated 237 A. alternata strains from nine greenhouses around metropolitan Kunming in Yunnan, southwest China, determined their genotypes using 10 short tandem repeat markers, and quantified their susceptibility to four triazoles (difenoconazole, tebuconazole, itraconazole, and voriconazole). Abundant allelic and genotypic diversities were detected among these A. alternata strains. Significantly, over 17% of the strains were resistant to difenoconazole, and both known and new drug-resistance mutations were found in the triazole target gene cyp51. Our findings of high-level genetic variation of A. alternata in greenhouses coupled with high-frequency fungicide resistance call for greater attention to continued monitoring and to developing alternative plant fungal disease management strategies in greenhouses. IMPORTANCE Alternaria alternata is among the most common fungi in our environments, such as indoor facilities, the soil, and outdoor air. It can cause diseases in >100 crop and ornamental plants. Furthermore, it can cause human infections. However, our understanding of its genetic diversity and antifungal susceptibility is very limited. Indeed, the critical threshold values for resistance have not been defined for most antifungal drugs in this species. Greenhouses are known to have heavy applications of agricultural fungicides. In this study, we analyzed strains of A. alternata from nine greenhouses near metropolitan Kunming in southwestern China. Our study revealed very high genetic diversity and identified strains with high MIC values against two agricultural and two medical triazole antifungals within each of the nine greenhouses. Our study calls for greater attention to this emerging threat to food security and human health.
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Affiliation(s)
- Guangzhu Yang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, People’s Republic of China
- School of Life Science, Yunnan University, Kunming, People’s Republic of China
- Horticultural Research Institute, Yunnan Academy of Agricultural Sciences, Kunming, People’s Republic of China
| | - Sai Cui
- School of Life Science, Yunnan University, Kunming, People’s Republic of China
| | - Nan Ma
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, People’s Republic of China
| | - Yuansha Song
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, People’s Republic of China
| | - Jun Ma
- Horticultural Research Institute, Yunnan Academy of Agricultural Sciences, Kunming, People’s Republic of China
| | - Wenjing Huang
- Horticultural Research Institute, Yunnan Academy of Agricultural Sciences, Kunming, People’s Republic of China
| | - Ying Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, People’s Republic of China
| | - Jianping Xu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, People’s Republic of China
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
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Viegas C, Almeida B, Aranha Caetano L, Afanou A, Straumfors A, Veríssimo C, Gonçalves P, Sabino R. Algorithm to assess the presence of Aspergillus fumigatus resistant strains: The case of Norwegian sawmills. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2022; 32:963-971. [PMID: 32814444 DOI: 10.1080/09603123.2020.1810210] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 08/11/2020] [Indexed: 05/24/2023]
Abstract
Association between selection pressure caused by the use of azole fungicides in sawmills and the development of fungal resistance has been described. The aim of this study was to implement an algorithm to assess the presence of Aspergillus section Fumigati resistant strains in sawmills.Eighty-six full-shift inhalable dust samples were collected from eleven industrial sawmills in Norway. Different culture media were used and molecular identification to species level in Aspergillus section Fumigati was done by calmodulin sequencing and TR34/L98H and TR46/Y121F/T289A mutations were screened by real-time PCR assay and confirmed by cyp51A sequencing. Six Fumigati isolates were identified as A. fumigatus sensu stricto and two of these grew on azole-supplemented media and were further analyzed by real-time PCR. One was confirmed to be a TR34/L98H mutant.The obtained results reinforce the need to assess the presence of A. fumigatus sensu stricto resistant isolates at other workplaces with fungicide pressure.
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Affiliation(s)
- Carla Viegas
- ESTeSL- Escola Superior De Tecnologia Da Saúde, Instituto Politécnico De Lisboa, Lisbon, Portugal
- NOVA National School of Public Health, Public Health Research Centre, Universidade NOVA De Lisboa Lisbon, Portugal
- Comprehensive Health Research Center (CHRC), Lisbon, Portugal
| | - Beatriz Almeida
- ESTeSL- Escola Superior De Tecnologia Da Saúde, Instituto Politécnico De Lisboa, Lisbon, Portugal
| | - Liliana Aranha Caetano
- ESTeSL- Escola Superior De Tecnologia Da Saúde, Instituto Politécnico De Lisboa, Lisbon, Portugal
- Research Institute for Medicines (Imed.ulisboa), Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal
| | - Anani Afanou
- Department of Chemical and Biological Work Environment, National Institute of Occupational Health (STAMI), Oslo, Norway
| | - Anne Straumfors
- Department of Chemical and Biological Work Environment, National Institute of Occupational Health (STAMI), Oslo, Norway
| | - Cristina Veríssimo
- Reference Unit for Parasitic and Fungal Infections, Infectious Diseases Department, National Institute of Health Dr. Ricardo Jorge, Lisbon, Portugal
| | - Paulo Gonçalves
- Reference Unit for Parasitic and Fungal Infections, Infectious Diseases Department, National Institute of Health Dr. Ricardo Jorge, Lisbon, Portugal
- European Centre for Disease Prevention and Control, European Programme for Public Health Microbiology Training (EUPHEM), Stockholm, Sweden
| | - Raquel Sabino
- Reference Unit for Parasitic and Fungal Infections, Infectious Diseases Department, National Institute of Health Dr. Ricardo Jorge, Lisbon, Portugal
- Faculdade De Medicina Da, Instituto De Saúde Ambiental, Universidade De Lisboa, Lisbon, Portugal
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Shao W, Wang J, Wang H, Wen Z, Liu C, Zhang Y, Zhao Y, Ma Z. Fusarium graminearum FgSdhC1 point mutation A78V confers resistance to the succinate dehydrogenase inhibitor pydiflumetofen. PEST MANAGEMENT SCIENCE 2022; 78:1780-1788. [PMID: 35014167 DOI: 10.1002/ps.6795] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 01/05/2022] [Accepted: 01/10/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Fusarium head blight (FHB) caused by Fusarium graminearum complex (Fg) is a devastating disease of cereal crops worldwide. The succinate dehydrogenase inhibitor, pydiflumetofen, was registered for management of FHB in China in 2019. Previously, laboratory-induced pydiflumetofen-resistant (PyR) mutants of Fg have been characterized. However, resistance situation of Fg to pydiflumetofen in the field remains largely unknown. RESULTS After screening 6468 isolates of Fg from various regions of China, six PyR isolates were identified. All six resistant isolates exhibited no fitness penalties based on mycelial growth, conidiation and virulence. However, no cross-resistance between pydiflumetofen and azoxystrobin, tebuconazole or fludioxonil in Fg was detected. Genome-sequencing revealed that all six PyR isolates contained a point mutation A78V in FgSdhC1 (FgSdhC1A78V ). Genetic replacement assay further confirmed that FgSdhC1A78V conferred resistance of Fg to pydiflumetofen. Based on this, a mismatch allele-specific polymerase chain reaction was developed for rapidly detecting the PyR isolates containing the FgSdhC1A78V mutation in Fg. CONCLUSION This is the first time that resistance of Fg to pydiflumetofen in the field was reported and point mutation FgSdhC1A78V conferring resistance of Fg to pydiflumetofen was confirmed. This study provides critical information for monitoring and managing pydiflumetofen resistance in Fg.
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Affiliation(s)
- Wenyong Shao
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Jingrui Wang
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Huiyuan Wang
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Ziyue Wen
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Chao Liu
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Yu Zhang
- Department of Crop Protection, Zhejiang Agriculture and Forest University, Hangzhou, 311300, China
| | - Youfu Zhao
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Zhonghua Ma
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
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Wang Y, Zhang L, Zhou L, Zhang M, Xu Y. Epidemiology, Drug Susceptibility, and Clinical Risk Factors in Patients With Invasive Aspergillosis. Front Public Health 2022; 10:835092. [PMID: 35493371 PMCID: PMC9051236 DOI: 10.3389/fpubh.2022.835092] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 03/04/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundThis study aimed to investigate the Aspergillus species distribution, antifungal sensitivities, clinical characteristics, and risk factors of patients with invasive aspergillosis (IA) in a tertiary teaching hospital in Anhui Province.MethodsIn the present study, 156 Aspergillus isolates were collected from patients admitted to a 2,800-bed comprehensive hospital between January 2019 and April 2021. The epidemiology of Aspergillus species was well-examined, and its antifungal susceptibility was specifically measured by the microbroth dilution method. The risk factors of patients with IA were documented and analyzed intensively. In addition, gene sequencing was employed to determine gene mutations of cytochrome P450 14-α sterol demethylase-Aspergillus (cyp51A) associated with azole resistance among Aspergillus fumigatus.ResultsThe Aspergillus species distribution was dominated by A. fumigatus (56.41%), Aspergillus flavus (20.51%), and Aspergillus niger (15.38%) locally. In particular, all Aspergillus species showed very low minimum inhibitory concentrations (MICs, ≤ 0.5 μg/ml) for azoles and echinocandins, slightly high MICs (1.66–2.91 μg/ml) for amphotericin B, and exceptionally high MICs (>64 μg/ml) for flucytosine. Azole-resistant rate of Aspergillus species in this local region reached up to 5.79%. Correlation analyses of multiple antifungals indicate a significant MIC relevance between isavuconazole and voriconazole (Pearson correlation coefficient was 0.81, P < 0.0001). The clinical risk factors for patients with IA were found primarily to be pulmonary diseases (P = 0.007) and patients' age (P < 0.001). Notably, three mutant loci (TR46/Y121F/T289A) of the cyp51A gene were identified in azole-resistant A. fumigatus.ConclusionsThe Aspergillus species emerged increasingly, of which A. fumigatus and A. flavus remained the main pathogens for invasive Aspergillus infections in the local region. The vast majority of Aspergillus species exhibited good susceptibility to all the antifungals, except flucytosine. The local occurrence of azole-resistant Aspergillus species grew gradually and needed monitoring in time. Pulmonary diseases and age were likely considered as highly associated risk factors for IA. To our knowledge, the clinically isolated azole-resistant A. fumigatus with TR46/Y121F/T289A mutations identified here were rarely reported in the area of China.
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30
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Species Distribution and Antifungal Susceptibilities of
Aspergillus
Section
Fumigati
Isolates in Clinical Samples from the United States. J Clin Microbiol 2022; 60:e0028022. [DOI: 10.1128/jcm.00280-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Aspergillus
species are capable of causing both invasive disease and chronic infections in immunocompromised patients or those with preexisting lung conditions.
Aspergillus fumigatus
is the most commonly cultured species, and there is increasing concern regarding resistance to the azoles, which are the mainstays of antifungal therapy against aspergillosis. We evaluated the species distribution and susceptibility profiles of isolates within
Aspergillus
section
Fumigati
in the United States over a 52-month period.
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Palmieri F, Koutsokera A, Bernasconi E, Junier P, von Garnier C, Ubags N. Recent Advances in Fungal Infections: From Lung Ecology to Therapeutic Strategies With a Focus on Aspergillus spp. Front Med (Lausanne) 2022; 9:832510. [PMID: 35386908 PMCID: PMC8977413 DOI: 10.3389/fmed.2022.832510] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 02/22/2022] [Indexed: 12/15/2022] Open
Abstract
Fungal infections are estimated to be the main cause of death for more than 1.5 million people worldwide annually. However, fungal pathogenicity has been largely neglected. This is notably the case for pulmonary fungal infections, which are difficult to diagnose and to treat. We are currently facing a global emergence of antifungal resistance, which decreases the chances of survival for affected patients. New therapeutic approaches are therefore needed to face these life-threatening fungal infections. In this review, we will provide a general overview on respiratory fungal infections, with a focus on fungi of the genus Aspergillus. Next, the immunological and microbiological mechanisms of fungal pathogenesis will be discussed. The role of the respiratory mycobiota and its interactions with the bacterial microbiota on lung fungal infections will be presented from an ecological perspective. Finally, we will focus on existing and future innovative approaches for the treatment of respiratory fungal infections.
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Affiliation(s)
- Fabio Palmieri
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- *Correspondence: Fabio Palmieri,
| | - Angela Koutsokera
- Faculty of Biology and Medicine, University of Lausanne, Service de Pneumologie, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Eric Bernasconi
- Faculty of Biology and Medicine, University of Lausanne, Service de Pneumologie, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Pilar Junier
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Christophe von Garnier
- Faculty of Biology and Medicine, University of Lausanne, Service de Pneumologie, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Niki Ubags
- Faculty of Biology and Medicine, University of Lausanne, Service de Pneumologie, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
- Niki Ubags,
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COVID-19 Associated Pulmonary Aspergillosis (CAPA): Hospital or Home Environment as a Source of Life-Threatening Aspergillus fumigatus Infection? J Fungi (Basel) 2022; 8:jof8030316. [PMID: 35330318 PMCID: PMC8952274 DOI: 10.3390/jof8030316] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 03/14/2022] [Accepted: 03/16/2022] [Indexed: 02/02/2023] Open
Abstract
Most cases of invasive aspergillosis are caused by Aspergillus fumigatus, whose conidia are ubiquitous in the environment. Additionally, in indoor environments, such as houses or hospitals, conidia are frequently detected too. Hospital-acquired aspergillosis is usually associated with airborne fungal contamination of the hospital air, especially after building construction events. A. fumigatus strain typing can fulfill many needs both in clinical settings and otherwise. The high incidence of aspergillosis in COVID patients from our hospital, made us wonder if they were hospital-acquired aspergillosis. The purpose of this study was to evaluate whether the hospital environment was the source of aspergillosis infection in CAPA patients, admitted to the Hospital Universitario Central de Asturias, during the first and second wave of the COVID-19 pandemic, or whether it was community-acquired aspergillosis before admission. During 2020, sixty-nine A. fumigatus strains were collected for this study: 59 were clinical isolates from 28 COVID-19 patients, and 10 strains were environmentally isolated from seven hospital rooms and intensive care units. A diagnosis of pulmonary aspergillosis was based on the ECCM/ISHAM criteria. Strains were genotyped by PCR amplification and sequencing of a panel of four hypervariable tandem repeats within exons of surface protein coding genes (TRESPERG). A total of seven genotypes among the 10 environmental strains and 28 genotypes among the 59 clinical strains were identified. Genotyping revealed that only one environmental A. fumigatus from UCI 5 (box 54) isolated in October (30 October 2020) and one A. fumigatus isolated from a COVID-19 patient admitted in Pneumology (Room 532-B) in November (24 November 2020) had the same genotype, but there was a significant difference in time and location. There was also no relationship in time and location between similar A. fumigatus genotypes of patients. The global A. fumigatus, environmental and clinical isolates, showed a wide diversity of genotypes. To our knowledge, this is the first study monitoring and genotyping A. fumigatus isolates obtained from hospital air and COVID-19 patients, admitted with aspergillosis, during one year. Our work shows that patients do not acquire A. fumigatus in the hospital. This proves that COVID-associated aspergillosis in our hospital is not a nosocomial infection, but supports the hypothesis of “community aspergillosis” acquisition outside the hospital, having the home environment (pandemic period at home) as the main suspected focus of infection.
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Meletiadis J, Efstathiou I, van der Lee HAL, Astvad KMT, Verweij PE, Arendrup MC. Spectrophotometric detection of azole-resistant Aspergillus fumigatus with the EUCAST broth microdilution method: is it time for automated MIC reading of EUCAST antifungal susceptibility testing of Aspergillus species? J Antimicrob Chemother 2022; 77:1296-1300. [PMID: 35194639 PMCID: PMC9840474 DOI: 10.1093/jac/dkac046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 01/25/2022] [Indexed: 01/19/2023] Open
Abstract
OBJECTIVES Current reference susceptibility testing methods of Aspergillus require visual reading, which is subjective and necessitates experienced staff. We compared spectrophotometric and visual MIC reading of EUCAST E.Def 9.3.2 susceptibility testing of Aspergillus fumigatus for a large collection of isolates with different azole resistance mechanisms. METHODS A. fumigatus (n = 200) were examined, including 62 WT and 138 non-WT with the following alterations: TR34/L98H (n = 57), TR46/Y121F/T289A (n = 54) or single point mutations (n = 27). EUCAST E.Def 9.3.2 susceptibility testing was performed for amphotericin B, itraconazole, voriconazole, posaconazole and isavuconazole. MICs were determined after 48 h of incubation visually and spectrophotometrically, as the lowest concentration corresponding to a 1%, 3%, 5%, 10% or 15% OD increase above the background OD. The best spectrophotometric endpoint (SPE) was identified based on the highest essential agreement (EA; ±1 two-fold dilution) and categorical agreement (CA) and fewer very major errors (VMEs) and major errors (MEs). RESULTS Τhe best SPEs were 5% and 10% for all drugs. The best agreement between visual and spectrophotometric MICs was found with the 10% growth endpoint, which resulted in identical median MICs with 90% of differences being ≤1 two-fold and higher EA (91%-100%) and CA (100%) and no VMEs and MEs compared with the 5% endpoint (77%-100%, 96%-98%, 0% and 0%-4%, respectively). CONCLUSIONS Spectrophotometric MIC reading can be used for A. fumigatus susceptibility testing and for detecting azole resistance. A visual inspection of the plate should be performed to confirm equal inoculation, absence of well contamination and proper growth, and to identify potential uncommon phenotypes or subpopulations.
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Affiliation(s)
| | - Ioanna Efstathiou
- Clinical Microbiology Laboratory, Attikon University Hospital, Athens, Greece
| | - Hein A L van der Lee
- Department of Medical Microbiology, Radboud University Medical Centre, and Center of Expertise in Mycology Radboudumc/CWZ, Nijmegen, The Netherlands
| | | | - Paul E Verweij
- Department of Medical Microbiology, Radboud University Medical Centre, and Center of Expertise in Mycology Radboudumc/CWZ, Nijmegen, The Netherlands,Centre for Infectious Diseases Research, Diagnostics and Laboratory Surveillance, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Maiken Cavling Arendrup
- Unit of Mycology, Statens Serum Institut, Copenhagen, Denmark,Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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Zhao H, Tao X, Song W, Xu H, Li M, Cai Y, Wang J, Duan Y, Zhou M. Mechanism of Fusarium graminearum Resistance to Ergosterol Biosynthesis Inhibitors: G443S Substitution of the Drug Target FgCYP51A. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:1788-1798. [PMID: 35129347 DOI: 10.1021/acs.jafc.1c07543] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Fusarium head blight (FHB), caused by the Fusarium graminearum species complex, is a devastating fungal disease resulting in substantial yield and quality losses. Ergosterol biosynthesis inhibitors (EBIs) are the most popular chemicals for controlling FHB. Recently, the resistance of F. graminearum to EBIs has emerged in the field, and an amino acid substitution (G443S) of the sterol 14α-demethylase FgCYP51A was detected in the field resistant strains. To further illustrate the resistance mechanism of F. graminearum to EBIs, site-directed mutants conferring the G443S substitution of FgCYP51A were generated from the progenitor strain PH-1 via genetic transformation with site-directed mutagenesis. We found that the FgCYP51A-G443S substitution significantly decreased the sensitivity of F. graminearum to EBIs with EC50 values ranging from 0.1190 to 0.2302 μg mL-1 and EC90 values ranging from 1.3420 to 9.1119 μg mL-1 for tebuconazole. Furthermore, the FgCYP51A-G443S substitution decreased sexual reproduction and virulence, which will reduce the initial infection source of pathogen populations in the field, while the increase of sporulation capability may enhance the frequencies of the disease cycle, thereby contributing to epidemics of FHB disease. Surprisingly, the FgCYP51A-G443S substitution accelerated DON biosynthesis by upregulating TRI5 expression and enhancing the fluorescence intensity of TRI1-GFP, the marker protein of Fusarium toxisomes. Thus, we concluded that the FgCYP51A-G443S substitution regulates EBI-fungicide resistance and DON biosynthesis, increasing the risk of fungicide resistance development in the field, thereby threatening the control efficacy of EBIs against FHB.
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Affiliation(s)
- Huahua Zhao
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Xian Tao
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Wen Song
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Haorong Xu
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Meixia Li
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Yiqiang Cai
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
- State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing 210095, China
| | - Jianxin Wang
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
- State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing 210095, China
| | - Yabing Duan
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
- State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing 210095, China
| | - Mingguo Zhou
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
- State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing 210095, China
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Kang SE, Sumabat LG, Melie T, Mangum B, Momany M, Brewer MT. Evidence for the agricultural origin of resistance to multiple antimicrobials in Aspergillus fumigatus, a fungal pathogen of humans. G3 (BETHESDA, MD.) 2022; 12:jkab427. [PMID: 34897421 PMCID: PMC9210323 DOI: 10.1093/g3journal/jkab427] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 12/03/2021] [Indexed: 11/12/2022]
Abstract
Pathogen resistance to clinical antimicrobial agents is an urgent problem. The fungus Aspergillus fumigatus causes 300,000 life-threatening infections in susceptible humans annually. Azoles, which are widely used in both clinical and agricultural settings, are currently the most effective treatment, but resistance to clinical azoles is emerging worldwide. Here, we report the isolation and analysis of azole-sensitive and azole-resistant A. fumigatus from agricultural environments in the southeastern United States (USA) and show that the USA pan-azole-resistant isolates form a clade with pan-azole-resistant isolates from the United Kingdom, the Netherlands, and India. We show that several pan-azole-resistant isolates from agricultural settings in the USA and India also carry alleles with mutations conferring resistance to agricultural fungicides from the benzimidazole (MBC) and quinone outside inhibitor (QoI) classes. We further show that pan-azole-resistant A. fumigatus isolates from patients in clinical settings in the USA, India, and the Netherlands also carry alleles conferring resistance to MBC and QoI agricultural fungicides. The presence of markers for resistance to agricultural-use fungicides in clinical A. fumigatus isolates is strong evidence for an agricultural origin of pan-azole resistance in patients. The presence of multiple fungicide-resistance alleles in agricultural and clinical isolates further suggests that the unique genetics of the pan-azole-resistant clade enables the evolution and/or persistence of antimicrobial resistance mutations leading to the establishment of multifungicide-resistant isolates.
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Affiliation(s)
- S Earl Kang
- Fungal Biology Group and Plant Biology Department, University of Georgia, Athens, GA 30602, USA
| | - Leilani G Sumabat
- Fungal Biology Group and Plant Pathology Department, University of Georgia, Athens, GA 30602, USA
| | - Tina Melie
- Fungal Biology Group and Plant Pathology Department, University of Georgia, Athens, GA 30602, USA
| | - Brandon Mangum
- Fungal Biology Group and Plant Biology Department, University of Georgia, Athens, GA 30602, USA
- Fungal Biology Group and Plant Pathology Department, University of Georgia, Athens, GA 30602, USA
| | - Michelle Momany
- Fungal Biology Group and Plant Biology Department, University of Georgia, Athens, GA 30602, USA
| | - Marin T Brewer
- Fungal Biology Group and Plant Pathology Department, University of Georgia, Athens, GA 30602, USA
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The Gβ-like Protein AfCpcB Affects Sexual Development, Response to Oxidative Stress and Phagocytosis by Alveolar Macrophages in Aspergillus fumigatus. J Fungi (Basel) 2022; 8:jof8010056. [PMID: 35049996 PMCID: PMC8777951 DOI: 10.3390/jof8010056] [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: 12/13/2021] [Revised: 12/26/2021] [Accepted: 01/04/2022] [Indexed: 12/17/2022] Open
Abstract
G-protein signaling is important for signal transduction, allowing various stimuli that are external to a cell to affect its internal molecules. In Aspergillus fumigatus, the roles of Gβ-like protein CpcB on growth, asexual development, drug sensitivity, and virulence in a mouse model have been previously reported. To gain a deeper insight into Aspergillus fumigatus sexual development, the ΔAfcpcB strain was generated using the supermater AFB62 strain and crossed with AFIR928. This cross yields a decreased number of cleistothecia, including few ascospores. The sexual reproductive organ-specific transcriptional analysis using RNAs from the cleistothecia (sexual fruiting bodies) indicated that the CpcB is essential for the completion of sexual development by regulating the transcription of sexual genes, such as veA, steA, and vosA. The ΔAfcpcB strain revealed increased resistance to oxidative stress by regulating genes for catalase, peroxiredoxin, and ergosterol biosynthesis. The ΔAfcpcB strain showed decreased uptake by alveolar macrophages in vitro, decreased sensitivity to Congo red, decreased expression of cell wall genes, and increased expression of the hydrophobin genes. Taken together, these findings indicate that AfCpcB plays important roles in sexual development, phagocytosis by alveolar macrophages, biosynthesis of the cell wall, and oxidative stress response.
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Genetic Diversity and Dispersal of Aspergillus fumigatus in Arctic Soils. Genes (Basel) 2021; 13:genes13010019. [PMID: 35052359 PMCID: PMC8774493 DOI: 10.3390/genes13010019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 12/20/2021] [Accepted: 12/21/2021] [Indexed: 12/22/2022] Open
Abstract
Aspergillus fumigatus is a saprophytic mold and an opportunistic pathogen with a broad geographic and ecological distribution. A. fumigatus is the most common etiological agent of aspergillosis, affecting over 8,000,000 individuals worldwide. Due to the rising number of infections and increasing reports of resistance to antifungal therapy, there is an urgent need to understand A. fumigatus populations from local to global levels. However, many geographic locations and ecological niches remain understudied, including soil environments from arctic regions. In this study, we isolated 32 and 52 A. fumigatus strains from soils in Iceland and the Northwest Territories of Canada (NWT), respectively. These isolates were genotyped at nine microsatellite loci and the genotypes were compared with each other and with those in other parts of the world. Though significantly differentiated from each other, our analyses revealed that A. fumigatus populations from Iceland and NWT contained evidence for both clonal and sexual reproductions, and shared many alleles with each other and with those collected from across Europe, Asia, and the Americas. Interestingly, we found one triazole-resistant strain containing the TR34 /L98H mutation in the cyp51A gene from NWT. This strain is closely related to a triazole-resistant genotype broadly distributed in India. Together, our results suggest that the northern soil populations of A. fumigatus are significantly influenced by those from other geographic regions.
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Lucio J, Gonzalez-Jimenez I, Garcia-Rubio R, Cuetara MS, Mellado E. An expanded agar-based screening method for azole-resistant Aspergillus fumigatus. Mycoses 2021; 65:178-185. [PMID: 34806786 DOI: 10.1111/myc.13400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 11/16/2021] [Accepted: 11/16/2021] [Indexed: 11/30/2022]
Abstract
Antifungal susceptibility testing is an essential tool for guiding antifungal therapy. Reference methods are complex and usually only available in specialised laboratories. We have designed an expanded agar-based screening method for the detection of azole-resistant Aspergillus fumigatus isolates. Normally, identification of resistance mechanisms is obtained only after sequencing the cyp51A gene and promoter. However, our screening method provides azole resistance detection and presumptive resistance mechanisms identification. A previous agar-based method consisting of four wells containing voriconazole, itraconazole, posaconazole and a growth control, detected azole resistance to clinical azoles. Here, we have modified the concentrations of voriconazole and posaconazole to adapt to the updated EUCAST breakpoints against A. fumigatus. We have also expanded the method to include environmental azoles to assess azole resistance and the azole resistance mechanism involved. We used a collection of A. fumigatus including 54 azole-resistant isolates with Cyp51A modifications (G54, M220, G448S, TR53 , TR34 /L98H, TR46 /Y121F/T289A, TR34 /L98H/S297T/F495I), and 50 azole susceptible isolates with wild-type Cyp51A. The screening method detects azole-resistant A. fumigatus isolates when there is growth in any of the azole-containing wells after 48h. The growth pattern in the seven azoles tested helps determine the underlying azole resistance mechanism. This approach is designed for surveillance screening of A. fumigatus azole-resistant isolates and can be useful for the clinical management of patients prior to antifungal susceptibility testing confirmation.
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Affiliation(s)
- Jose Lucio
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Spain
| | - Irene Gonzalez-Jimenez
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Spain
| | - Rocio Garcia-Rubio
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Spain
| | | | - Emilia Mellado
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Spain.,Spanish Network for Research in Infectious Diseases (REIPI RD16/0016), ISCIII, Majadahonda, Spain
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Rocchi S, Sewell TR, Valot B, Godeau C, Laboissiere A, Millon L, Fisher MC. Molecular Epidemiology of Azole-Resistant Aspergillus fumigatus in France Shows Patient and Healthcare Links to Environmentally Occurring Genotypes. Front Cell Infect Microbiol 2021; 11:729476. [PMID: 34660341 PMCID: PMC8512841 DOI: 10.3389/fcimb.2021.729476] [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: 06/23/2021] [Accepted: 09/09/2021] [Indexed: 01/14/2023] Open
Abstract
Resistance of the human pathogenic fungus Aspergillus fumigatus to antifungal agents is on the rise. However, links between patient infections, their potential acquisition from local environmental sources, and links to global diversity remain cryptic. Here, we used genotyping analyses using nine microsatellites in A. fumigatus, in order to study patterns of diversity in France. In this study, we genotyped 225 local A. fumigatus isolates, 112 azole susceptible and 113 azole resistant, collected from the Bourgogne-Franche-Comté region (Eastern France) and sampled from both clinical (n = 34) and environmental (n = 191) sources. Azole-resistant clinical isolates (n = 29) were recovered mainly from cystic fibrosis patients and environmental isolates (n = 84) from market gardens and sawmills. In common with previous studies, the TR34/L98H allele predominated and comprised 80% of resistant isolates. The genotypes obtained for these local TR34/L98H isolates were integrated into a broader analysis including all genotypes for which data are available worldwide. We found that dominant local TR34/L98H genotypes were isolated in different sample types at different dates (different patients and types of environments) with hospital air and patient's isolates linked. Therefore, we are not able to rule out the possibility of some nosocomial transmission. We also found genotypes in these same environments to be highly diverse, emphasizing the highly mixed nature of A. fumigatus populations. Identical clonal genotypes were found to occur both in the French Eastern region and in the rest of the world (notably Australia), while others have not yet been observed and could be specific to our region. Our study demonstrates the need to integrate patient, healthcare, and environmental sampling with global databases in order to contextualize the local-scale epidemiology of antifungal resistant aspergillosis.
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Affiliation(s)
- Steffi Rocchi
- Department of Parasitology and Mycology, Centre Hospitalier Universitaire, Besançon, France.,Chrono-Environnement Research Team UMR/CNRS-6249, Bourgogne-Franche-Comté University, Besançon, France
| | - Thomas R Sewell
- Medical Research Council (MRC) Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial School of Public Health, Imperial College London, London, United Kingdom
| | - Benoit Valot
- Chrono-Environnement Research Team UMR/CNRS-6249, Bourgogne-Franche-Comté University, Besançon, France
| | - Chloé Godeau
- Chrono-Environnement Research Team UMR/CNRS-6249, Bourgogne-Franche-Comté University, Besançon, France
| | - Audrey Laboissiere
- Chrono-Environnement Research Team UMR/CNRS-6249, Bourgogne-Franche-Comté University, Besançon, France
| | - Laurence Millon
- Department of Parasitology and Mycology, Centre Hospitalier Universitaire, Besançon, France.,Chrono-Environnement Research Team UMR/CNRS-6249, Bourgogne-Franche-Comté University, Besançon, France
| | - Matthew C Fisher
- Medical Research Council (MRC) Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial School of Public Health, Imperial College London, London, United Kingdom
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Gonzalez-Jimenez I, Lucio J, Roldan A, Alcazar-Fuoli L, Mellado E. Are Point Mutations in HMG-CoA Reductases (Hmg1 and Hmg2) a Step towards Azole Resistance in Aspergillus fumigatus? Molecules 2021; 26:5975. [PMID: 34641518 PMCID: PMC8512156 DOI: 10.3390/molecules26195975] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 09/28/2021] [Accepted: 09/30/2021] [Indexed: 11/16/2022] Open
Abstract
Invasive aspergillosis, mainly caused by Aspergillus fumigatus, can lead to severe clinical outcomes in immunocompromised individuals. Antifungal treatment, based on the use of azoles, is crucial to increase survival rates. However, the recent emergence of azole-resistant A. fumigatus isolates is affecting the efficacy of the clinical therapy and lowering the success rate of azole strategies against aspergillosis. Azole resistance mechanisms described to date are mainly associated with mutations in the azole target gene cyp51A that entail structural changes in Cyp51A or overexpression of the gene. However, strains lacking cyp51A modifications but resistant to clinical azoles have recently been detected. Some genes have been proposed as new players in azole resistance. In this study, the gene hmg1, recently related to azole resistance, and its paralogue hmg2 were studied in a collection of fifteen azole-resistant strains without cyp51A modifications. Both genes encode HMG-CoA reductases and are involved in the ergosterol biosynthesis. Several mutations located in the sterol sensing domain (SSD) of Hmg1 (D242Y, G307D/S, P309L, K319Q, Y368H, F390L and I412T) and Hmg2 (I235S, V303A, I312S, I360F and V397C) were detected. The role of these mutations in conferring azole resistance is discussed in this work.
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Affiliation(s)
- Irene Gonzalez-Jimenez
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), 28220 Majadahonda, Madrid, Spain; (I.G.-J.); (J.L.); (A.R.); (L.A.-F.)
| | - Jose Lucio
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), 28220 Majadahonda, Madrid, Spain; (I.G.-J.); (J.L.); (A.R.); (L.A.-F.)
| | - Alejandra Roldan
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), 28220 Majadahonda, Madrid, Spain; (I.G.-J.); (J.L.); (A.R.); (L.A.-F.)
| | - Laura Alcazar-Fuoli
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), 28220 Majadahonda, Madrid, Spain; (I.G.-J.); (J.L.); (A.R.); (L.A.-F.)
- Spanish Network for Research in Infectious Diseases (REIPI RD16/CIII/0004/0003), ISCIII, 28220 Majadahonda, Madrid, Spain
| | - Emilia Mellado
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), 28220 Majadahonda, Madrid, Spain; (I.G.-J.); (J.L.); (A.R.); (L.A.-F.)
- Spanish Network for Research in Infectious Diseases (REIPI RD16/CIII/0004/0003), ISCIII, 28220 Majadahonda, Madrid, Spain
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Melo AM, Poester VR, Canabarro PL, Sampaio DA, Stevens DA, Veríssimo C, Sabino R, Xavier MO. Molecular epidemiology of aspergillosis in Magellanic penguins and susceptibility patterns of clinical isolates. Med Mycol 2021; 59:1076-1084. [PMID: 34320182 DOI: 10.1093/mmy/myab040] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 06/14/2021] [Indexed: 11/14/2022] Open
Abstract
Aspergillus section Fumigati is reported in up to 99% of aspergillosis cases in penguins. So far, no data regarding molecular epidemiology and azole resistance are available for A. fumigatus isolates collected from Magellanic penguins. The aim of this work was to perform molecular identification of Aspergillus section Fumigati at species level, to genotype those isolates using microsatellite markers, to evaluate the in vitro susceptibility patterns of A. fumigatus sensu stricto, and to characterize the cyp51A gene in clinical A. fumigatus strains isolated from Magellanic penguins with proven aspergillosis. All 34 isolates included in the study were identified as A. fumigatus sensu stricto. Analyzing the genetic diversity of the isolates of A. fumigatus sensu stricto, we identified two possible outbreaks in the rehabilitation center and we also observed the maintenance of clonal strains through the years. One A. fumigatus sensu stricto isolate was resistant to posaconazole, but the mutations found in the cyp51A gene of this isolate have not been described as conferring phenotypic resistance, suggesting that other mechanisms of resistance could be involved in the resistance of this isolate. With this study we were able to understand the molecular diversity of Aspergillus fumigatus isolates collected from Magellanic penguins, to characterize them and to associate them with the described global population of Aspergillus fumigatus.
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Affiliation(s)
- Aryse Martins Melo
- Microbiology and Parasitology Post-Graduate Program, Institute of Biology, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil.,National Institute of Health, Dr. Ricardo Jorge, Av. Padre Cruz, 1649-016, Lisbon, Portugal
| | - Vanice Rodrigues Poester
- Health Sciences Post-Graduation Program, Medical College, Federal University of Rio Grande, Rio Grande, Rio Grande do Sul, Brazil
| | - Paula Lima Canabarro
- Rehabilitation Center for Marine Animals, Federal University of Rio Grande (CRAM-FURG), Rio Grande, Rio Grande do Sul, Brazil
| | - Daniel Ataíde Sampaio
- Technology and Innovation Unit, Department of Human Genetics, National Institute of Health, Lisbon, Portugal
| | - David A Stevens
- Division of Infectious Diseases and Geographic Medicine, Stanford University Medical School, Stanford, California, USA.,California Institute for Medical Research, San Jose, California, USA
| | - Cristina Veríssimo
- National Institute of Health, Dr. Ricardo Jorge, Av. Padre Cruz, 1649-016, Lisbon, Portugal
| | - Raquel Sabino
- National Institute of Health, Dr. Ricardo Jorge, Av. Padre Cruz, 1649-016, Lisbon, Portugal.,Instituto de Saúde Ambiental, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Melissa Orzechowski Xavier
- Microbiology and Parasitology Post-Graduate Program, Institute of Biology, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil.,Health Sciences Post-Graduation Program, Medical College, Federal University of Rio Grande, Rio Grande, Rio Grande do Sul, Brazil
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42
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Point mutation or overexpression of A. fumigatus cyp51B, encoding lanosterol 14α-sterol demethylase, leads to triazole resistance. Antimicrob Agents Chemother 2021; 65:e0125221. [PMID: 34310208 DOI: 10.1128/aac.01252-21] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Aspergillus fumigatus is the most common cause of invasive fungal mold infections in immunocompromised individuals. Current antifungal treatment relies heavily on the triazole antifungals which inhibit fungal Erg11/Cyp51 activity and subsequent ergosterol biosynthesis. However, resistance, due primarily to cyp51 mutation, is rapidly increasing. A. fumigatus contains two Cyp51 isoenzymes, Cyp51A and Cyp51B. Overexpression and mutation of Cyp51A is a major cause of triazole resistance in A. fumigatus. The role of Cyp51B in generating resistance is unclear. Here we show that overexpression or mutation of cyp51B results in triazole resistance. We demonstrate that introduction of a G457S Cyp51B mutation identified in a resistant clinical isolate, results in voriconazole resistance in the naïve recipient strain. Our results indicate that mutations in cyp51B resulting in clinical resistance do exist and should be monitored.
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Parent-Michaud M, Dufresne PJ, Fournier E, Folch B, Martineau C, Moreira S, Doucet N, De Repentigny L, Dufresne SF. Prevalence and mechanisms of azole resistance in clinical isolates of Aspergillus section Fumigati species in a Canadian tertiary care centre, 2000 to 2013. J Antimicrob Chemother 2021; 75:849-858. [PMID: 31891387 DOI: 10.1093/jac/dkz534] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 11/14/2019] [Accepted: 12/01/2019] [Indexed: 01/02/2023] Open
Abstract
OBJECTIVES Azole resistance among Aspergillus fumigatus isolates is a growing concern worldwide. Induction of mutations during azole therapy, environment-acquired mutations caused by azole fungicides and intrinsic resistance of cryptic Fumigati species all contribute to the burden of resistance. However, there is a lack of data in Canada on this emerging threat. METHODS To gain insights into the magnitude and mechanisms of resistance, a 14 year collection of Aspergillus section Fumigati comprising 999 isolates from 807 patients at a Montreal hospital was screened for azole resistance, and resistance mechanisms were investigated with the combined use of genome sequencing, 3D modelling and phenotypic efflux pump assays. RESULTS Overall azole resistance was low (4/807 patients; 0.5%). A single azole-resistant A. fumigatus sensu stricto strain, isolated from a patient with pulmonary aspergillosis, displayed efflux-pump-mediated resistance. Three patients were colonized or infected with azole-resistant cryptic Fumigati species (one Aspergillus thermomutatus, one Aspergillus lentulus and one Aspergillus turcosus). Evidence is presented that azole resistance is efflux-pump-mediated in the A. turcosus isolate, but not in the A. lentulus and A. thermomutatus isolates. CONCLUSIONS Azole resistance is rare in our geographic area and currently driven by cryptic Fumigati species. Continued surveillance of emergence of resistance is warranted.
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Affiliation(s)
- Maxime Parent-Michaud
- Department of Microbiology, Infectious Diseases and Immunology, University of Montreal, Montreal, Quebec, Canada
| | - Philippe J Dufresne
- Laboratoire de santé publique du Québec, Institut national de santé publique du Québec, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Eric Fournier
- Laboratoire de santé publique du Québec, Institut national de santé publique du Québec, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Benjamin Folch
- INRS-Institut Armand Frappier, University of Quebec, Laval, Quebec, Canada
| | - Christine Martineau
- Laboratoire de santé publique du Québec, Institut national de santé publique du Québec, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Sandrine Moreira
- Laboratoire de santé publique du Québec, Institut national de santé publique du Québec, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Nicolas Doucet
- INRS-Institut Armand Frappier, University of Quebec, Laval, Quebec, Canada
| | - Louis De Repentigny
- Department of Microbiology, Infectious Diseases and Immunology, University of Montreal, Montreal, Quebec, Canada
| | - Simon F Dufresne
- Department of Microbiology, Infectious Diseases and Immunology, University of Montreal, Montreal, Quebec, Canada.,Division of Infectious Diseases and Clinical Microbiology, Department of Medicine, Maisonneuve-Rosemont Hospital, Montreal, Quebec, Canada
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James JE, Lamping E, Santhanam J, Cannon RD. PDR Transporter ABC1 Is Involved in the Innate Azole Resistance of the Human Fungal Pathogen Fusarium keratoplasticum. Front Microbiol 2021; 12:673206. [PMID: 34149660 PMCID: PMC8211738 DOI: 10.3389/fmicb.2021.673206] [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: 02/27/2021] [Accepted: 04/22/2021] [Indexed: 12/30/2022] Open
Abstract
Fusarium keratoplasticum is arguably the most common Fusarium solani species complex (FSSC) species associated with human infections. Invasive fusariosis is a life-threatening fungal infection that is difficult to treat with conventional azole antifungals. Azole drug resistance is often caused by the increased expression of pleiotropic drug resistance (PDR) ATP-binding cassette (ABC) transporters of the ABCG sub-family. Most investigations of Fusarium ABC transporters associated with azole antifungal drug resistance are limited to plant pathogens. Through the manual curation of the entire ABCG protein family of four FSSC species including the fully annotated genome of the plant pathogen Nectria haematococca we identified PDR transporters ABC1 and ABC2 as the efflux pump candidates most likely to be associated with the innate azole resistance phenotype of Fusarium keratoplasticum. An initial investigation of the transcriptional response of logarithmic phase F. keratoplasticum cells to 16 mg/L voriconazole confirmed strong upregulation (372-fold) of ABC1 while ABC2 mRNA levels were unaffected by voriconazole exposure over a 4 h time-period. Overexpression of F. keratoplasticum ABC1 and ABC2 in the genetically modified Saccharomyces cerevisiae host ADΔΔ caused up to ∼1,024-fold increased resistance to a number of xenobiotics, including azole antifungals. Although ABC1 and ABC2 were only moderately (20% and 10%, respectively) expressed compared to the Candida albicans multidrug efflux pump CDR1, overexpression of F. keratoplasticum ABC1 caused even higher resistance levels to certain xenobiotics (e.g., rhodamine 6G and nigericin) than CDR1. Our investigations suggest an important role for ABC1 orthologues in the innate azole resistance phenotype of FSSC species.
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Affiliation(s)
- Jasper Elvin James
- Biomedical Science Programme, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.,Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Erwin Lamping
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Jacinta Santhanam
- Biomedical Science Programme, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Richard David Cannon
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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Devoto TB, Alava KSH, Pola SJ, Pereda R, Rubeglio E, Finquelievich JL, Cuestas ML. Molecular epidemiology of Aspergillus species and other moulds in respiratory samples from Argentinean patients with cystic fibrosis. Med Mycol 2021; 58:867-873. [PMID: 31915834 DOI: 10.1093/mmy/myz133] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/29/2019] [Accepted: 12/19/2019] [Indexed: 12/29/2022] Open
Abstract
In cystic fibrosis (CF) patients, fungal colonization of the respiratory tract is frequently found. Aspergillus fumigatus is the most frequently recorded and is associated with loss of pulmonary function and allergic disease (ABPA). The knowledge on prevalence rates of filamentous fungi in CF patients in Latin America is scarce. One hundred and seventy-six fungal isolates recovered from the upper respiratory tract of CF patients from Argentina were identified to species by morphology and DNA sequencing. In total, 90% of CF patients were colonized by Aspergillus sp., followed by Exophiala sp. (14%) and Scedosporium sp. (10%). Among Aspergillus, six species complexes (Fumigati, Flavi, Terrei, Nigri, Usti, and Nidulante) and different cryptospecies were found. Among Scedosporium, three species were observed (Scedosporium apiospermum, Scedosporium aurantiacum and Scedosporium boydii). All Exophiala isolates were identified as Exophiala dermatitidis. Rare filamentous fungi were also found. All cases of ABPA were associated to the presence of A. fumigatus. Mixed colonization with other mould or rare fungi was observed in half of them. To our knowledge, this is the first prospective study of mould species in CF using molecular methods in Latin America. This study shows that Aspergillus sp., E. dermatitidis and Scedosporium sp. have a high frequency in CF patients from Argentina, and by far, A. fumigatus was the most commonly cultured species. Continuous clinical surveillance is required to detect the emergence of new fungal pathogens and to detect resistant or difficult-to-treat species capable of chronic colonizing the airways and of hematogenous dissemination in case of lung transplantation.
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Affiliation(s)
- Tomás Brito Devoto
- Universidad de Buenos Aires. CONICET. Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM). Buenos Aires, Argentina
| | - Katherine Stefania Hermida Alava
- Universidad de Buenos Aires. CONICET. Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM). Buenos Aires, Argentina
| | - Santiago J Pola
- Universidad de Buenos Aires. CONICET. Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM). Buenos Aires, Argentina
| | - Rosana Pereda
- Hospital General de Niños Pedro de Elizalde. Sección Microbiología. Buenos Aires, Argentina
| | - Etelvina Rubeglio
- Universidad de Buenos Aires. CONICET. Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM). Buenos Aires, Argentina
| | - Jorge L Finquelievich
- Universidad de Buenos Aires. CONICET. Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM). Buenos Aires, Argentina
| | - María L Cuestas
- Universidad de Buenos Aires. CONICET. Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM). Buenos Aires, Argentina
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Emergence of Triazole Resistance in Aspergillus spp. in Latin America. CURRENT FUNGAL INFECTION REPORTS 2021; 15:93-103. [PMID: 34025901 PMCID: PMC8132279 DOI: 10.1007/s12281-021-00418-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2021] [Indexed: 11/26/2022]
Abstract
Purpose of Review Azole resistance in Aspergillus spp. is becoming a public health problem worldwide. However, data about this subject is lacking in Latin American countries. This review focuses in the epidemiology and molecular mechanisms of azole resistance in Aspergillus spp. emphasizing in Latin America. Data on Aspergillus fumigatus stands out because it is the most prevalent Aspergillus spp. pathogen. Recent Findings Azole resistance in Aspergillus spp. emergence was linked with intensive use of these antifungals both in the clinical setting and in the environment (as pesticides). Reports on azole-resistant A. fumigatus strains are being constantly published in different countries. Molecular mechanisms of resistance mainly involve substitution in the azole target (CYP51A) and/or overexpression of this gene. However, several other non-CYP51A-related mechanisms were described. Moreover, intrinsically resistant cryptic Aspergillus species are starting to be reported as human pathogens. Summary After a comprehensive literature review, it is clear that azole resistance in Aspergillus spp. is emerging in Latin America and perhaps it is underestimated. All the main molecular mechanisms of azole resistance were described in patients and/or environmental samples. Moreover, one of the molecular mechanisms was described only in South America. Cryptic intrinsic azole-resistant species are also described.
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Azole Resistance in Clinical and Environmental Aspergillus Isolates from the French West Indies (Martinique). J Fungi (Basel) 2021; 7:jof7050355. [PMID: 33946598 PMCID: PMC8147181 DOI: 10.3390/jof7050355] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 11/17/2022] Open
Abstract
The emergence of azole resistant Aspergillus spp., especially Aspergillus fumigatus, has been described in several countries around the world with varying prevalence depending on the country. To our knowledge, azole resistance in Aspergillus spp. has not been reported in the West Indies yet. In this study, we investigated the antifungal susceptibility of clinical and environmental isolates of Aspergillus spp. from Martinique, and the potential resistance mechanisms associated with mutations in cyp51A gene. Overall, 208 Aspergillus isolates were recovered from clinical samples (n = 45) and environmental soil samples (n = 163). They were screened for resistance to azole drugs using selective culture media. The Minimum Inhibitory Concentrations (MIC) towards voriconazole, itraconazole, posaconazole and isavuconazole, as shown by the resistant isolates, were determined using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) microdilution broth method. Eight isolates (A. fumigatus, n = 6 and A. terreus, n = 2) had high MIC for at least one azole drug. The sequencing of cyp51A gene revealed the mutations G54R and TR34/L98H in two A. fumigatus clinical isolates. Our study showed for the first time the presence of azole resistance in A. fumigatus and A. terreus isolates in the French West Indies.
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Analysis of the cyp51 genes contribution to azole resistance in Aspergillus section Nigri with the CRISPR-Cas9 technique. Antimicrob Agents Chemother 2021; 65:AAC.01996-20. [PMID: 33685892 PMCID: PMC8092891 DOI: 10.1128/aac.01996-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cyp51 contribution to azole resistance has been broadly studied and characterized in Aspergillus fumigatus, whereas it remains poorly investigated in other clinically relevant species of the genus, such as those of section Nigri In this work, we aimed to analyze the impact of cyp51 genes (cyp51A and cyp51B) on the voriconazole (VRC) response and resistance of Aspergillus niger and Aspergillus tubingensis We generated CRISPR-Cas9 cyp51A and cyp51B knock-out mutants from strains with different genetic backgrounds and diverse patterns of azole susceptibility. Single gene deletions of cyp51 genes resulted in 2 to 16-fold decrease of the VRC Minimum Inhibitory Concentration (MIC) values, which were below the VRC Epidemiological Cutoff Value (ECV) established by the Clinical and Laboratory Standards Institute (CLSI) irrespective of their parental strains susceptibilities. Gene expression studies in the tested species confirmed that cyp51A participates more actively than cyp51B in the transcriptional response of azole stress. However, ergosterol quantification revealed that both enzymes comparably impact the total ergosterol content within the cell, as basal and VRC-induced changes to ergosterol content was similar in all cases. These data contribute to our understanding on Aspergillus azole resistance, especially in non-fumigatus species.
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Rocchi S, Godeau C, Scherer E, Reboux G, Millon L. One year later: The effect of changing azole-treated bulbs for organic tulips bulbs in hospital environment on the azole-resistant Aspergillus fumigatus rate. Med Mycol 2021; 59:741-743. [PMID: 33690850 DOI: 10.1093/mmy/myab007] [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: 12/02/2020] [Revised: 01/08/2021] [Accepted: 01/25/2021] [Indexed: 01/31/2023] Open
Abstract
Azole-treated plant bulbs have already been evoked as a potential explanation of the worldwide spread of azole-resistant Aspergillus fumigatus (ARAf). We previously pointed out the presence of a high rate of ARAf (71% of A. fumigatus detected on azole-supplemented media) in flower beds containing azole-treated bulbs at the hospital's surroundings. We show here that planting organic bulbs can be a solution to reduce ARAf burden (from 71% rate to below 3%). The results suggest that replacing treated bulbs with organic bulbs may be sufficient to regain a population that is predominantly susceptible in just 1 year. LAY SUMMARY Antifungal resistance is increasingly observed in fungal pathogens. This study argues that planting organic bulbs in hospitals' outdoor surroundings could be a good alternative to continue to beautify green spaces, without the risk of dissipating antifungal-resistant fungal pathogens.
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Affiliation(s)
- Steffi Rocchi
- Parasitology-Mycology Department, University Hospital, 25000, Besançon, France.,Chrono-Environnement UMR 6249 CNRS, Bourgogne Franche-Comté University, 25000, Besançon, France
| | - Chloé Godeau
- Chrono-Environnement UMR 6249 CNRS, Bourgogne Franche-Comté University, 25000, Besançon, France
| | - Emeline Scherer
- Parasitology-Mycology Department, University Hospital, 25000, Besançon, France.,Chrono-Environnement UMR 6249 CNRS, Bourgogne Franche-Comté University, 25000, Besançon, France
| | - Gabriel Reboux
- Parasitology-Mycology Department, University Hospital, 25000, Besançon, France.,Chrono-Environnement UMR 6249 CNRS, Bourgogne Franche-Comté University, 25000, Besançon, France
| | - Laurence Millon
- Parasitology-Mycology Department, University Hospital, 25000, Besançon, France.,Chrono-Environnement UMR 6249 CNRS, Bourgogne Franche-Comté University, 25000, Besançon, France
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Hu M, Chen S. Non-Target Site Mechanisms of Fungicide Resistance in Crop Pathogens: A Review. Microorganisms 2021; 9:microorganisms9030502. [PMID: 33673517 PMCID: PMC7997439 DOI: 10.3390/microorganisms9030502] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 02/18/2021] [Accepted: 02/23/2021] [Indexed: 01/15/2023] Open
Abstract
The rapid emergence of resistance in plant pathogens to the limited number of chemical classes of fungicides challenges sustainability and profitability of crop production worldwide. Understanding mechanisms underlying fungicide resistance facilitates monitoring of resistant populations at large-scale, and can guide and accelerate the development of novel fungicides. A majority of modern fungicides act to disrupt a biochemical function via binding a specific target protein in the pathway. While target-site based mechanisms such as alternation and overexpression of target genes have been commonly found to confer resistance across many fungal species, it is not uncommon to encounter resistant phenotypes without altered or overexpressed target sites. However, such non-target site mechanisms are relatively understudied, due in part to the complexity of the fungal genome network. This type of resistance can oftentimes be transient and noninheritable, further hindering research efforts. In this review, we focused on crop pathogens and summarized reported mechanisms of resistance that are otherwise related to target-sites, including increased activity of efflux pumps, metabolic circumvention, detoxification, standing genetic variations, regulation of stress response pathways, and single nucleotide polymorphisms (SNPs) or mutations. In addition, novel mechanisms of drug resistance recently characterized in human pathogens are reviewed in the context of nontarget-directed resistance.
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Affiliation(s)
- Mengjun Hu
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD 20742, USA
- Correspondence: (M.H.); (S.C.)
| | - Shuning Chen
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- Correspondence: (M.H.); (S.C.)
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