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Hui ST, Gifford H, Rhodes J. Emerging Antifungal Resistance in Fungal Pathogens. CURRENT CLINICAL MICROBIOLOGY REPORTS 2024; 11:43-50. [PMID: 38725545 PMCID: PMC11076205 DOI: 10.1007/s40588-024-00219-8] [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] [Accepted: 02/09/2024] [Indexed: 05/12/2024]
Abstract
Purpose of Review Over recent decades, the number of outbreaks caused by fungi has increased for humans, plants (including important crop species) and animals. Yet this problem is compounded by emerging antifungal drug resistance in pathogenic species. Resistance develops over time when fungi are exposed to drugs either in the patient or in the environment. Recent Findings Novel resistant variants of fungal pathogens that were previously susceptible are evolving (such as Aspergillus fumigatus) as well as newly emerging fungal species that are displaying antifungal resistance profiles (e.g. Candida auris and Trichophyton indotineae). Summary This review highlights the important topic of emerging antifungal resistance in fungal pathogens and how it evolved, as well as how this relates to a growing public health burden.
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Affiliation(s)
- Sui Ting Hui
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, UK
| | - Hugh Gifford
- MRC Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Johanna Rhodes
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, UK
- Department of Medical Microbiology, Radboudumc, the Netherlands
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2
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Gupta AK, Talukder M, Carviel JL, Cooper EA, Piguet V. Combatting antifungal resistance: Paradigm shift in the diagnosis and management of onychomycosis and dermatomycosis. J Eur Acad Dermatol Venereol 2023; 37:1706-1717. [PMID: 37210652 DOI: 10.1111/jdv.19217] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 04/26/2023] [Indexed: 05/22/2023]
Abstract
Antifungal resistance has become prevalent worldwide. Understanding the factors involved in spread of resistance allows the formulation of strategies to slow resistance development and likewise identify solutions for the treatment of highly recalcitrant fungal infections. To investigate the recent explosion of resistant strains, a literature review was performed focusing on four main areas: mechanisms of resistance to antifungal agents, diagnosis of superficial fungal infections, management, and stewardship. The use of traditional diagnostic tools such as culture, KOH analysis and minimum inhibitory concentration values on treatment were investigated and compared to the newer techniques such as molecular methods including whole genome sequencing, and polymerase chain reaction. The management of terbinafine-resistant strains is discussed. We have emphasized the need for antifungal stewardship including increasing surveillance for resistant infection.
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Affiliation(s)
- Aditya K Gupta
- Mediprobe Research Inc., London, Ontario, Canada
- Division of Dermatology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Mesbah Talukder
- Mediprobe Research Inc., London, Ontario, Canada
- School of Pharmacy, BRAC University, Dhaka, Bangladesh
| | | | | | - Vincent Piguet
- Division of Dermatology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
- Division of Dermatology, Women's College Hospital, Toronto, Ontario, Canada
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Sardana K, Sharath S, Khurana A, Ghosh S. An update on the myriad antifungal resistance mechanisms in dermatophytes and the place of experimental and existential therapeutic agents for Trichophyton complex implicated in tinea corporis and cruris. Expert Rev Anti Infect Ther 2023; 21:977-991. [PMID: 37606343 DOI: 10.1080/14787210.2023.2250555] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 08/17/2023] [Indexed: 08/23/2023]
Abstract
INTRODUCTION There is an epidemic emergence of increased resistance in dermatophytes with to antifungal drugs with ergosterol1 (Erg1) and Erg11 mutations to terbinafine and azoles. Apart from mutations, mechanisms that predict clinical failure include efflux pumps, cellular kinases, heat shock proteins (Hsp), and biofilms. Apart from itraconazole and SUBATM (Super-Bioavailable) itraconazole, measures that can be used in terbinafine failure include efflux-pump inhibitors, Hsp inhibitors and judicious use of antifungal drugs (topical + systemic) combinations. AREAS COVERED A PubMed search was done for the relevant studies and reviews published in the last 22 years using keywords dermatophytes OR Trichophyton, anti-fungal, resistance, mechanism and fungal AND resistance mechanisms. Our aim was to look for literature on prevalent species and we specifically researched studies on Trichophyton genus. We have analyzed varied antifungal drug mechanisms and detailed varied experimental and approved drugs to treat recalcitrant dermatophytosis. EXPERT OPINION Apart from administering drugs with low minimum inhibitory concentration, combinations of oral and topical antifungals (based on synergy data) and new formulations of existing drugs are useful in recalcitrant cases. There is a need for research into resistance mechanism of the existent Trichophyton strains in therapeutic failures in tinea corporis & cruris instead of data derived from laboratory strains which may not mirror clinical failures.
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Affiliation(s)
- Kabir Sardana
- Department of Dermatology, Venereology and Leprosy, Atal Bihari Vajpayee Institute of Medical Sciences and Research Institute and Dr Ram Manohar Lohia Hospital, New Delhi, India
| | - Savitha Sharath
- Department of Dermatology, Venereology and Leprosy, Atal Bihari Vajpayee Institute of Medical Sciences and Research Institute and Dr Ram Manohar Lohia Hospital, New Delhi, India
| | - Ananta Khurana
- Department of Dermatology, Venereology and Leprosy, Atal Bihari Vajpayee Institute of Medical Sciences and Research Institute and Dr Ram Manohar Lohia Hospital, New Delhi, India
| | - Shamik Ghosh
- Rejuvenation Technologies Inc, Harvard Medical School, New York City, NY, USA
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Hammoudi Halat D, Younes S, Mourad N, Rahal M. Allylamines, Benzylamines, and Fungal Cell Permeability: A Review of Mechanistic Effects and Usefulness against Fungal Pathogens. MEMBRANES 2022; 12:membranes12121171. [PMID: 36557078 PMCID: PMC9781035 DOI: 10.3390/membranes12121171] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/14/2022] [Accepted: 11/16/2022] [Indexed: 05/30/2023]
Abstract
Allylamines, naftifine and terbinafine, and the benzylamine, butenafine, are antifungal agents with activity on the fungal cell membrane. These synthetic compounds specifically inhibit squalene epoxidase, a key enzyme in fungal sterol biosynthesis. This results in a deficiency in ergosterol, a major fungal membrane sterol that regulates membrane fluidity, biogenesis, and functions, and whose damage results in increased membrane permeability and leakage of cellular components, ultimately leading to fungal cell death. With the fungal cell membrane being predominantly made up of lipids including sterols, these lipids have a vital role in the pathogenesis of fungal infections and the identification of improved therapies. This review will focus on the fungal cell membrane structure, activity of allylamines and benzylamines, and the mechanistic damage they cause to the membrane. Furthermore, pharmaceutical preparations and clinical uses of these drugs, mainly in dermatophyte infections, will be reviewed.
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Affiliation(s)
- Dalal Hammoudi Halat
- Department of Pharmaceutical Sciences, School of Pharmacy, Lebanese International University, Bekaa 146404, Lebanon
| | - Samar Younes
- Department of Biomedical Sciences, School of Pharmacy, Lebanese International University, Bekaa 146404, Lebanon
| | - Nisreen Mourad
- Department of Pharmaceutical Sciences, School of Pharmacy, Lebanese International University, Bekaa 146404, Lebanon
| | - Mohamad Rahal
- Department of Pharmaceutical Sciences, School of Pharmacy, Lebanese International University, Bekaa 146404, Lebanon
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Benjamin G, Pandharikar G, Frendo P. Salicylic Acid in Plant Symbioses: Beyond Plant Pathogen Interactions. BIOLOGY 2022; 11:861. [PMID: 35741382 PMCID: PMC9220041 DOI: 10.3390/biology11060861] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 06/01/2022] [Accepted: 06/02/2022] [Indexed: 01/02/2023]
Abstract
Plants form beneficial symbioses with a wide variety of microorganisms. Among these, endophytes, arbuscular mycorrhizal fungi (AMF), and nitrogen-fixing rhizobia are some of the most studied and well understood symbiotic interactions. These symbiotic microorganisms promote plant nutrition and growth. In exchange, they receive the carbon and metabolites necessary for their development and multiplication. In addition to their role in plant growth and development, these microorganisms enhance host plant tolerance to a wide range of environmental stress. Multiple studies have shown that these microorganisms modulate the phytohormone metabolism in the host plant. Among the phytohormones involved in the plant defense response against biotic environment, salicylic acid (SA) plays an important role in activating plant defense. However, in addition to being a major actor in plant defense signaling against pathogens, SA has also been shown to be involved in plant-microbe symbiotic interactions. In this review, we summarize the impact of SA on the symbiotic interactions. In addition, we give an overview of the impact of the endophytes, AMF, and rhizobacteria on SA-mediated defense response against pathogens.
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Affiliation(s)
| | | | - Pierre Frendo
- Université Côte d’Azur, INRAE, CNRS, ISA, 06000 Nice, France;
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Fan Y, Korfanty GA, Xu J. Genetic Analyses of Amphotericin B Susceptibility in Aspergillus fumigatus. J Fungi (Basel) 2021; 7:860. [PMID: 34682281 PMCID: PMC8538161 DOI: 10.3390/jof7100860] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 09/28/2021] [Accepted: 10/11/2021] [Indexed: 11/25/2022] Open
Abstract
Aspergillus fumigatus is a ubiquitous saprophytic mold that can cause a range of clinical syndromes, from allergic reactions to invasive infections. Amphotericin B (AMB) is a polyene antifungal drug that has been used to treat a broad range of systemic mycoses since 1958, including as a primary treatment option against invasive aspergillosis in regions with high rates (≥10%) of environmental triazole resistance. However, cases of AMB-resistant A. fumigatus strains have been increasingly documented over the years, and high resistance rates were recently reported in Brazil and Canada. The objective of this study is to identify candidate mutations associated with AMB susceptibility using a genome-wide association analysis of natural strains, and to further investigate a subset of the mutations in their putative associations with differences in AMB minimum inhibitory concentration (MIC) and in growths at different AMB concentrations through the analysis of progeny from a laboratory genetic cross. Together, our results identified a total of 34 candidate single-nucleotide polymorphisms (SNPs) associated with AMB MIC differences-comprising 18 intergenic variants, 14 missense variants, one synonymous variant, and one non-coding transcript variant. Importantly, progeny from the genetic cross allowed us to identify putative SNP-SNP interactions impacting progeny growth at different AMB concentrations.
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Affiliation(s)
| | | | - Jianping Xu
- Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada; (Y.F.); (G.A.K.)
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Zhou F, Last RL, Pichersky E. Degradation of salicylic acid to catechol in Solanaceae by SA 1-hydroxylase. PLANT PHYSIOLOGY 2021; 185:876-891. [PMID: 33793924 PMCID: PMC8133591 DOI: 10.1093/plphys/kiaa096] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 12/07/2020] [Indexed: 05/16/2023]
Abstract
The hormone salicylic acid (SA) plays crucial roles in plant defense, stress responses, and in the regulation of plant growth and development. Whereas the biosynthetic pathways and biological functions of SA have been extensively studied, SA catabolism is less well understood. In this study, we report the identification and functional characterization of an FAD/NADH-dependent SA 1-hydroxylase from tomato (Solanum lycopersicum; SlSA1H), which catalyzes the oxidative decarboxylation of SA to catechol. Transcript levels of SlSA1H were highest in stems and its expression was correlated with the formation of the methylated catechol derivatives guaiacol and veratrole. Consistent with a role in SA catabolism, SlSA1H RNAi plants accumulated lower amounts of guaiacol and failed to produce any veratrole. Two O-methyltransferases involved in the conversion of catechol to guaiacol and guaiacol to veratrole were also functionally characterized. Subcellular localization analyses revealed the cytosolic localization of this degradation pathway. Phylogenetic analysis and functional characterization of SA1H homologs from other species indicated that this type of FAD/NADH-dependent SA 1-hydroxylases evolved recently within the Solanaceae family.
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Affiliation(s)
- Fei Zhou
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Robert L Last
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48823, USA
- Department of Plant Biology, Michigan State University, East Lansing, MI 48823, USA
| | - Eran Pichersky
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
- Author for correspondence:
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Discovery and Functional Analysis of a Salicylic Acid Hydroxylase from Aspergillus niger. Appl Environ Microbiol 2021; 87:AEM.02701-20. [PMID: 33397706 DOI: 10.1128/aem.02701-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 12/19/2020] [Indexed: 11/20/2022] Open
Abstract
Salicylic acid plays an important role in the plant immune response, and its degradation is therefore important for plant-pathogenic fungi. However, many nonpathogenic microorganisms can also degrade salicylic acid. In the filamentous fungus Aspergillus niger, two salicylic acid metabolic pathways have been suggested. The first pathway converts salicylic acid to catechol by a salicylate hydroxylase (ShyA). In the second pathway, salicylic acid is 3-hydroxylated to 2,3-dihydroxybenzoic acid, followed by decarboxylation to catechol by 2,3-dihydroxybenzoate decarboxylase (DhbA). A. niger cleaves the aromatic ring of catechol catalyzed by catechol 1,2-dioxygenase (CrcA) to form cis,cis-muconic acid. However, the identification and role of the genes and characterization of the enzymes involved in these pathways are lacking. In this study, we used transcriptome data of A. niger grown on salicylic acid to identify genes (shyA and crcA) involved in salicylic acid metabolism. Heterologous production in Escherichia coli followed by biochemical characterization confirmed the function of ShyA and CrcA. The combination of ShyA and CrcA demonstrated that cis,cis-muconic acid can be produced from salicylic acid. In addition, the in vivo roles of shyA, dhbA, and crcA were studied by creating A. niger deletion mutants which revealed the role of these genes in the fungal metabolism of salicylic acid.IMPORTANCE Nonrenewable petroleum sources are being depleted, and therefore, alternative sources are needed. Plant biomass is one of the most abundant renewable sources on Earth and is efficiently degraded by fungi. In order to utilize plant biomass efficiently, knowledge about the fungal metabolic pathways and the genes and enzymes involved is essential to create efficient strategies for producing valuable compounds such as cis,cis-muconic acid. cis,cis-Muconic acid is an important platform chemical that is used to synthesize nylon, polyethylene terephthalate (PET), polyurethane, resins, and lubricants. Currently, cis,cis-muconic acid is mainly produced through chemical synthesis from petroleum-based chemicals. Here, we show that two enzymes from fungi can be used to produce cis,cis-muconic acid from salicylic acid and contributes in creating alternative methods for the production of platform chemicals.
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Comparative Genomic Analysis of Dactylonectria torresensis Strains from Grapevine, Soil and Weed Highlights Potential Mechanisms in Pathogenicity and Endophytic Lifestyle. J Fungi (Basel) 2020; 6:jof6040255. [PMID: 33138048 PMCID: PMC7712071 DOI: 10.3390/jof6040255] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/26/2020] [Accepted: 10/27/2020] [Indexed: 01/19/2023] Open
Abstract
The soil-borne fungus Dactylonectria torresensis is the most common causal agent of black-foot disease in Europe. However, there is a lack of understanding on how this fungus can provoke plant symptoms. In this study, we sequenced, annotated and analyzed the genomes of three isolates of D. torresensis collected from asymptomatic vine, weed and soil. Sequenced genomes were further compared to those of 27 fungal species including root and aerial pathogens, white rot degraders, indoor biodeterioration agents, saprotrophs, dark septate endophytes and mycorrhiza. Strains of D. torresensis present genomes with between 64 and 65 Mbp and with up to 18,548 predicted genes for each strain. Average Nucleotide Identity (ANI) shows that strains are different according to genome contents. Clusters of orthologous groups were compared, and clusters of genes related to necroses were particularly detected in all strains of D. torresensis (necrosis inducing peptides and proteins, and ethylene inducing peptides) as well as several genes involved in resistance against fungicides frequently used in viticulture such as copper. Interestingly, an expanded high number of genes related to carbohydrate-active enzymes were detected in each Dactylonectria strain, especially those related to glycoside hydrolases that could be involved in penetration of plant tissues or pathogenicity. An increased number of candidate genes for CAZyme classes AA9 and AA3-1 supports the ability of strains to efficiently degrade plant material. High numbers of genes of D. torresensis related to secretome and small secreted proteins were further characterized. Moreover, the presence of several gene clusters such as fujikurin-like genes was detected and were normally found in Fusariumfujikuroi, that have been linked to fungal pathogenicity. The phenotypes of the three strains investigated showed further difference in light response. We found that Dactylonectria strains have an increased number of photoreceptor encoding genes and we showed sequence alterations. Altogether, the results highlight several gene clusters present in D. torresensis strains that could be linked to endophytic lifestyle, pathogenicity, plant maceration and degradation of plant tissues as well as adaptation to soil contaminated with metals and metalloids and light response.
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Antifungal resistance in dermatophytes: Recent trends and therapeutic implications. Fungal Genet Biol 2019; 132:103255. [PMID: 31330295 DOI: 10.1016/j.fgb.2019.103255] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/17/2019] [Accepted: 07/17/2019] [Indexed: 12/15/2022]
Abstract
Dermatophytoses or tinea refers to superficial fungal infection of keratinized tissues. Although generally considered easy to treat, recalcitrant infections, presenting as extensive and difficult to treat tinea corporis and cruris, are on the rise in some parts of the world. The situation demands an understanding of the pharmacokinetic and pharmacodynamic properties of the available antifungals against dermatophytes and the possible contribution of drug resistance and other factors to the present scenario. In this review, we provide the readers a comprehensive account of the available literature on in-vitro and in-vivo resistance to clinically used antifungals among dermatophytes. We have also added, in brief, the relevant skin pharmacokinetics of important systemic drugs. The established and postulated mechanisms of drug resistance are discussed and aspects on lack of in vivo correlation of in vitro resistance are presented. Finally, the lacunae in our existing knowledge on the topic and the arenas for future research are highlighted.
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11
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Facilitators of adaptation and antifungal resistance mechanisms in clinically relevant fungi. Fungal Genet Biol 2019; 132:103254. [PMID: 31326470 DOI: 10.1016/j.fgb.2019.103254] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/16/2019] [Accepted: 07/16/2019] [Indexed: 12/12/2022]
Abstract
Opportunistic fungal pathogens can cause a diverse range of diseases in humans. The increasing rate of fungal infections caused by strains that are resistant to commonly used antifungals results in difficulty to treat diseases, with accompanying high mortality rates. Existing and newly emerging molecular resistance mechanisms rapidly spread in fungal populations and need to be monitored. Fungi exhibit a diversity of mechanisms to maintain physiological resilience and create genetic variation; processes which eventually lead to the selection and spread of resistant fungal pathogens. To prevent and anticipate this dispersion, the role of evolutionary factors that drive fungal adaptation should be investigated. In this review, we provide an overview of resistance mechanisms against commonly used antifungal compounds in the clinic and for which fungal resistance has been reported. Furthermore, we aim to summarize and elucidate potent generators of genetic variability across the fungal kingdom that aid adaptation to stressful environments. This knowledge can lead to recognizing potential niches that facilitate fast resistance development and can provide leads for new management strategies to battle the emerging resistant populations in the clinic and the environment.
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Abstract
Patients with suppressed immunity are at the highest risk for hospital-acquired infections. Among these, invasive candidiasis is the most prevalent systemic fungal nosocomial infection. Over recent decades, the combined prevalence of non-albicans Candida species outranked Candida albicans infections in several geographical regions worldwide, highlighting the need to understand their pathobiology in order to develop effective treatment and to prevent future outbreaks. Candida parapsilosis is the second or third most frequently isolated Candida species from patients. Besides being highly prevalent, its biology differs markedly from that of C. albicans, which may be associated with C. parapsilosis' increased incidence. Differences in virulence, regulatory and antifungal drug resistance mechanisms, and the patient groups at risk indicate that conclusions drawn from C. albicans pathobiology cannot be simply extrapolated to C. parapsilosis Such species-specific characteristics may also influence their recognition and elimination by the host and the efficacy of antifungal drugs. Due to the availability of high-throughput, state-of-the-art experimental tools and molecular genetic methods adapted to C. parapsilosis, genome and transcriptome studies are now available that greatly contribute to our understanding of what makes this species a threat. In this review, we summarize 10 years of findings on C. parapsilosis pathogenesis, including the species' genetic properties, transcriptome studies, host responses, and molecular mechanisms of virulence. Antifungal susceptibility studies and clinician perspectives are discussed. We also present regional incidence reports in order to provide an updated worldwide epidemiology summary.
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Pandey V, Gupta AK, Singh M, Pandey D, Kumar A. Complementary Proteomics, Genomics approaches identifies potential pathogenicity/virulence factors in Tilletia indica induced under the influence of host factor. Sci Rep 2019; 9:553. [PMID: 30679765 PMCID: PMC6346058 DOI: 10.1038/s41598-018-37810-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 12/05/2018] [Indexed: 12/21/2022] Open
Abstract
Karnal bunt disease of wheat is incited by quarantine fungal pathogen T. indica. Till date, there is little information on the pathogenic mechanisms involved in Karnal bunt. In order to understand the molecular mechanisms of disease pathogenesis, highly aggressive T. indica TiK isolate was cultured in the presence of host factor extracted from developing spikes of wheat variety WH-542. Modulation in protein profile of mycelial proteins and secretome from TiK cultured in the absence and presence of host factor was analyzed by 2-DE. Fifteen and twenty nine protein spots were up-regulated/differentially regulated in the proteome of mycelial and secreted proteins, respectively and identified using MALDI-TOF/TOF. Identified proteins are involved in suppression of host defense responses, lignin degradation of plant cell wall, penetration, adhesion of pathogen to host tissues, pathogen mediated reactive oxygen species generation, hydrolytic enzymes, detoxification of host generated reactive oxygen species. Further, integration of proteomic and genomic analysis has led to candidate pathogenicity/virulence factors identification. They were functionally annotated by sequence as well as structure based analysis. In this study, complementation of proteomics and genomics approaches resulted in novel pathogenicity/virulence factor(s) identification in T. indica.
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Affiliation(s)
- Vishakha Pandey
- Department of Molecular biology and Genetic Engineering, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India
| | - Atul Kumar Gupta
- Department of Molecular biology and Genetic Engineering, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India.
| | - Manoj Singh
- Department of Molecular biology and Genetic Engineering, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India
| | - Dinesh Pandey
- Department of Molecular biology and Genetic Engineering, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India
| | - Anil Kumar
- Department of Molecular biology and Genetic Engineering, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India.
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Hao G, Naumann TA, Vaughan MM, McCormick S, Usgaard T, Kelly A, Ward TJ. Characterization of a Fusarium graminearum Salicylate Hydroxylase. Front Microbiol 2019; 9:3219. [PMID: 30671040 PMCID: PMC6331432 DOI: 10.3389/fmicb.2018.03219] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 12/11/2018] [Indexed: 11/13/2022] Open
Abstract
Salicylic acid (SA) plays an important role in regulating plant defense responses against pathogens. However, pathogens have evolved ways to manipulate plant SA-mediated defense signaling. Fusarium graminearum causes Fusarium head blight (FHB) and reduces crop yields and quality by producing various mycotoxins. In this study, we aimed to identify the salicylate hydroxylase in F. graminearum and determine its role in wheat head blight development. We initially identified a gene in F. graminearum strain NRRL 46422 that encodes a putative salicylate hydroxylase (designated FgShyC). However, the FgShyC deletion mutant showed a similar ability to degrade SA as wild-type strain 46422; nor did overexpression of FgShyC in E. coli convert SA to catechol. The results indicate that FgShyC is not involved in SA degradation. Further genome sequence analyses resulted in the identification of eight salicylate hydroxylase candidates. Upon addition of 1 mM SA, FGSG_03657 (designated FgShy1), was induced approximately 400-fold. Heterologous expression of FgShy1 in E. coli converted SA to catechol, confirming that FgShy1 is a salicylate hydroxylase. Deletion mutants of FgShy1 were greatly impaired but not completely blocked in SA degradation. Expression analyses of infected tissue showed that FgShy1 was induced during infection, but virulence assays revealed that deletion of FgShy1 alone was not sufficient to affect FHB severity. Although the Fgshy1 deletion mutant did not reduce pathogenicity, we cannot rule out that additional salicylate hydroxylases are present in F. graminearum and characterization of these enzymes will be necessary to fully understand the role of SA-degradation in FHB pathogenesis.
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Affiliation(s)
- Guixia Hao
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture – Agricultural Research Service, Peoria, IL, United States
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Martinez-Rossi NM, Bitencourt TA, Peres NTA, Lang EAS, Gomes EV, Quaresemin NR, Martins MP, Lopes L, Rossi A. Dermatophyte Resistance to Antifungal Drugs: Mechanisms and Prospectus. Front Microbiol 2018; 9:1108. [PMID: 29896175 PMCID: PMC5986900 DOI: 10.3389/fmicb.2018.01108] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 05/09/2018] [Indexed: 12/24/2022] Open
Abstract
Dermatophytes comprise pathogenic fungi that have a high affinity for the keratinized structures present in nails, skin, and hair, causing superficial infections known as dermatophytosis. A reasonable number of antifungal drugs currently exist on the pharmaceutical market to control mycoses; however, their cellular targets are restricted, and fungi may exhibit tolerance or resistance to these agents. For example, the stress caused by antifungal and cytotoxic drugs in sub-inhibitory concentrations promotes compensatory stress responses, with the over-expression of genes involved in cellular detoxification, drug efflux, and signaling pathways being among the various mechanisms that may contribute to drug tolerance. In addition, the ATP-binding cassette transporters in dermatophytes that are responsible for cellular efflux can act synergistically, allowing one to compensate for the absence of the other, revealing the complexity of drug tolerance phenomena. Moreover, mutations in genes coding for target enzymes could lead to substitutions in amino acids involved in the binding of antifungal agents, hindering their performance and leading to treatment failure. The relevance of each one of these mechanisms of resistance to fungal survival is hard to define, mainly because they can act simultaneously in the cell. However, an understanding of the molecular mechanisms involved in the resistance/tolerance processes, the identification of new antifungal targets, as well as the prospective of new antifungal compounds among natural or synthetic products, are expected to bring advances and new insights that facilitate the improvement or development of novel strategies for antifungal therapy.
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Affiliation(s)
- Nilce M Martinez-Rossi
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Tamires A Bitencourt
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Nalu T A Peres
- Department of Morphology, Federal University of Sergipe, Aracaju, Brazil
| | - Elza A S Lang
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Eriston V Gomes
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Natalia R Quaresemin
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Maíra P Martins
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Lucia Lopes
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Antonio Rossi
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
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16
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Rudramurthy SM, Shankarnarayan SA, Dogra S, Shaw D, Mushtaq K, Paul RA, Narang T, Chakrabarti A. Mutation in the Squalene Epoxidase Gene of Trichophyton interdigitale and Trichophyton rubrum Associated with Allylamine Resistance. Antimicrob Agents Chemother 2018; 62:e02522-17. [PMID: 29530857 PMCID: PMC5923174 DOI: 10.1128/aac.02522-17] [Citation(s) in RCA: 157] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 02/25/2018] [Indexed: 11/20/2022] Open
Abstract
Dermatophytosis, the commonest superficial fungal infection, has gained recent attention due to its change of epidemiology and treatment failures. Despite the availability of several agents effective against dermatophytes, the incidences of chronic infection, reinfection, and treatment failures are on the rise. Trichophyton rubrum and Trichophyton interdigitale are the two species most frequently identified among clinical isolates in India. Consecutive patients (n = 195) with suspected dermatophytosis during the second half of 2014 were included in this study. Patients were categorized into relapse and new cases according to standard definitions. Antifungal susceptibility testing of the isolated Trichophyton species (n = 127) was carried out with 12 antifungal agents: fluconazole, voriconazole, itraconazole, ketoconazole, sertaconazole, clotrimazole, terbinafine, naftifine, amorolfine, ciclopirox olamine, griseofulvin, and luliconazole. The squalene epoxidase gene was evaluated for mutation (if any) in 15 T. interdigitale and 5 T. rubrum isolates exhibiting high MICs for terbinafine. A T1189C mutation was observed in four T. interdigitale and two T. rubrum isolates. This transition leads to the change of phenylalanine to leucine in the 397th position of the squalene epoxidase enzyme. In homology modeling the mutant residue was smaller than the wild type and positioned in the dominant site of squalene epoxidase during drug interaction, which may lead to a failure to block the ergosterol biosynthesis pathway by the antifungal drug.
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Affiliation(s)
- Shivaprakash M Rudramurthy
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Shamanth A Shankarnarayan
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Sunil Dogra
- Department of Dermatology, Venerology and Leprosy, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Dipika Shaw
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | | | - Raees A Paul
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Tarun Narang
- Department of Dermatology, Venerology and Leprosy, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Arunaloke Chakrabarti
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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17
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Comparative Transcriptome Analysis Reveals the Mechanism Underlying 3,5-Dibromo-4-Hydroxybenzoate Catabolism via a New Oxidative Decarboxylation Pathway. Appl Environ Microbiol 2018; 84:AEM.02467-17. [PMID: 29305508 DOI: 10.1128/aem.02467-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 12/13/2017] [Indexed: 02/07/2023] Open
Abstract
The compound 3,5-dibromo-4-hydroxybenzoate (DBHB) is both anthropogenically released into and naturally produced in the environment, and its environmental fate is of great concern. Aerobic and anaerobic reductive dehalogenations are the only two reported pathways for DBHB catabolism. In this study, a new oxidative decarboxylation pathway for DBHB catabolism was identified in a DBHB-utilizing strain, Pigmentiphaga sp. strain H8. The genetic determinants underlying this pathway were elucidated based on comparative transcriptome analysis and subsequent experimental validation. A gene cluster comprising orf420 to orf426, with transcripts that were about 33- to 4,400-fold upregulated in DBHB-induced cells compared with those in uninduced cells, was suspected to be involved in DBHB catabolism. The gene odcA (orf420), which is essential for the initial catabolism of DBHB, encodes a novel NAD(P)H-dependent flavin monooxygenase that mediates the oxidative decarboxylation of DBHB to 2,6-dibromohydroquinone (2,6-DBHQ). The substrate specificity of the purified OdcA indicated that the 4-hydroxyl group and its ortho-halogen(s) are important for hydroxylation of the C-1 site carboxyl group by OdcA. 2,6-DBHQ is then ring cleaved by the dioxygenase OdcB (Orf425) to 2-bromomaleylacetate, which is finally transformed to β-ketoadipate by the maleylacetate reductase OdcC (Orf426). These results provide a better understanding of the molecular mechanism underlying the catabolic diversity of halogenated para-hydroxybenzoates.IMPORTANCE Halogenated hydroxybenzoates (HBs), which are widely used synthetic precursors for chemical products and common metabolic intermediates from halogenated aromatics, exert considerable adverse effects on human health and ecological security. Microbial catabolism plays key roles in the dissipation of halogenated HBs in the environment. In this study, the discovery of a new catabolic pathway for 3,5-dibromo-4-hydroxybenzoate (DBHB) and clarification of the genetic determinants underlying the pathway broaden our knowledge of the catabolic diversity of halogenated HBs in microorganisms. Furthermore, the NAD(P)H-dependent flavin monooxygenase OdcA identified in Pigmentiphaga sp. strain H8 represents a novel 1-monooxygenase for halogenated para-HBs found in prokaryotes and enhances our knowledge of the decarboxylative hydroxylation of (halogenated) para-HBs.
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18
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Kong C, Huang H, Xue Y, Liu Y, Peng Q, Liu Q, Xu Q, Zhu Q, Yin Y, Zhou X, Zhang Y, Cai M. Heterologous pathway assembly reveals molecular steps of fungal terreic acid biosynthesis. Sci Rep 2018; 8:2116. [PMID: 29391515 PMCID: PMC5794859 DOI: 10.1038/s41598-018-20514-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 01/19/2018] [Indexed: 12/11/2022] Open
Abstract
Terreic acid is a potential anticancer drug as it inhibits Bruton's tyrosine kinase; however, its biosynthetic molecular steps remain unclear. In this work, the individual reactions of terreic acid biosynthesis were determined by stepwise pathway assembly in a heterologous host, Pichia pastoris, on the basis of previous knockout studies in a native host, Aspergillus terreus. Polyketide synthase AtX was found to catalyze the formation of partially reduced polyketide 6-methylsalicylic acid, followed by 3-methylcatechol synthesis by salicylate 1-monooxygenase AtA-mediated decarboxylative hydroxylation of 6-methylsalicylic acid. Our results show that cytochrome P450 monooxygenase AtE hydroxylates 3-methylcatechol, thus producing the next product, 3-methyl-1,2,4-benzenetriol. A smaller putative cytochrome P450 monooxygenase, AtG, assists with this step. Then, AtD causes epoxidation and hydroxyl oxidation of 3-methyl-1,2,4-benzenetriol and produces a compound terremutin, via which the previously unknown function of AtD was identified as cyclooxygenation. The final step involves an oxidation reaction of a hydroxyl group by a glucose-methanol-choline oxidoreductase, AtC, which leads to the final product: terreic acid. Functions of AtD and AtG were determined for the first time. All the genes were reanalyzed and all intermediates and final products were isolated and identified. Our model fully defines the molecular steps and corrects previous results from the literature.
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Affiliation(s)
- Chuixing Kong
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Hezhou Huang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Ying Xue
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Yiqi Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Qiangqiang Peng
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Qi Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Qin Xu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Qiaoyun Zhu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Ying Yin
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Xiangshan Zhou
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Yuanxing Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
- Shanghai Collaborative Innovation Center for Biomanufacturing, 130 Meilong Road, Shanghai, 200237, China
| | - Menghao Cai
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.
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19
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Martinez-Rossi NM, Jacob TR, Sanches PR, Peres NTA, Lang EAS, Martins MP, Rossi A. Heat Shock Proteins in Dermatophytes: Current Advances and Perspectives. Curr Genomics 2016; 17:99-111. [PMID: 27226766 PMCID: PMC4864838 DOI: 10.2174/1389202917666151116212437] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Revised: 07/02/2015] [Accepted: 07/13/2015] [Indexed: 11/29/2022] Open
Abstract
Heat shock proteins (HSPs) are proteins whose transcription responds rapidly to temperature shifts. They constitute a family of molecular chaperones, involved in the proper folding and stabilisation of proteins under physiological and adverse conditions. HSPs also assist in the protection and recovery of cells exposed to a variety of stressful conditions, including heat. The role of HSPs extends beyond chaperoning proteins, as they also participate in diverse cellular functions, such as the assembly of macromolecular complexes, protein transport and sorting, dissociation of denatured protein aggregates, cell cycle control, and programmed cell death. They are also important antigens from a variety of pathogens, are able to stimulate innate immune cells, and are implicated in acquired immunity. In fungi, HSPs have been implicated in virulence, dimorphic transition, and drug resistance. Some HSPs are potential targets for therapeutic strategies. In this review, we discuss the current understanding of HSPs in dermatophytes, which are a group of keratinophilic fungi responsible for superficial mycoses in humans and animals. Computational analyses were performed to characterise the group of proteins in these dermatophytes, as well as to assess their conservation and to identify DNA-binding domains (5′-nGAAn-3′) in the promoter regions of the hsp genes. In addition, the quantification of the transcript levels of few genes in a pacC background helped in the development of an extended model for the regulation of the expression of the hsp genes, which supports the participation of the pH-responsive transcriptional regulator PacC in this process.
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Affiliation(s)
- Nilce M Martinez-Rossi
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Tiago R Jacob
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Pablo R Sanches
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Nalu T A Peres
- Present address: Department of Morphology, Federal University of Sergipe, SE, Brazil
| | - Elza A S Lang
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Maíra P Martins
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Antonio Rossi
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
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20
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Ambrose KV, Tian Z, Wang Y, Smith J, Zylstra G, Huang B, Belanger FC. Functional characterization of salicylate hydroxylase from the fungal endophyte Epichloë festucae. Sci Rep 2015; 5:10939. [PMID: 26055188 PMCID: PMC4460724 DOI: 10.1038/srep10939] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 05/11/2015] [Indexed: 01/24/2023] Open
Abstract
Epichloë spp. are symbiotic fungal endophytes of many cool season grasses. The presence of the fungal endophytes often confers insect, drought, and disease tolerance to the host grasses. The presence of the fungal endophytes within the host plants does not elicit host defense responses. The molecular basis for this phenomenon is not known. Epichloë festucae, the endophyte of Festuca rubra, expresses a salicylate hydroxylase similar to NahG from the bacterium Pseudomonas putida. Few fungal salicylate hydroxylase enzymes have been reported. The in planta expression of an endophyte salicylate hydroxylase raised the possibility that degradation of plant-produced salicylic acid is a factor in the mechanism of how the endophyte avoids eliciting host plant defenses. Here we report the characterization of the E. festucae salicylate hydroxylase, designated Efe-shyA. Although the fungal enzyme has the expected activity, based on salicylic acid levels in endophyte-free and endophyte-infected plants it is unlikely that expression of the endophyte salicylate hydroxylase is a factor in the lack of a host defense response to the presence of the fungal endophyte.
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Affiliation(s)
- Karen V. Ambrose
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, New Jersey 08901
| | - Zipeng Tian
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, New Jersey 08901
| | - Yifei Wang
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, New Jersey 08901
| | - Jordan Smith
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, New Jersey 08901
| | - Gerben Zylstra
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey 08901
| | - Bingru Huang
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, New Jersey 08901
| | - Faith C. Belanger
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, New Jersey 08901
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21
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Alipour M, Mozafari N. Terbinafine susceptibility and genotypic heterogeneity in clinical isolates of Trichophyton mentagrophytes by random amplified polymorphic DNA (RAPD). J Mycol Med 2015; 25:e1-9. [DOI: 10.1016/j.mycmed.2014.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 09/12/2014] [Accepted: 09/16/2014] [Indexed: 10/24/2022]
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22
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Guo CJ, Sun WW, Bruno KS, Wang CCC. Molecular genetic characterization of terreic acid pathway in Aspergillus terreus. Org Lett 2014; 16:5250-3. [PMID: 25265334 PMCID: PMC4201328 DOI: 10.1021/ol502242a] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
![]()
Terreic acid is a natural product
derived from 6-methylsalicylic
acid (6-MSA). A compact gene cluster for its biosynthesis was characterized.
Isolation of the intermediates and shunt products from the mutant
strains, combined with bioinformatic analyses, allowed for the proposition
of a biosynthetic pathway for terreic acid.
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Affiliation(s)
- Chun-Jun Guo
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California , Los Angeles, California 90089, United States
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23
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Boruta T, Bizukojc M. Culture-based and sequence-based insights into biosynthesis of secondary metabolites by Aspergillus terreus ATCC 20542. J Biotechnol 2014; 175:53-62. [PMID: 24534845 DOI: 10.1016/j.jbiotec.2014.01.038] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 01/28/2014] [Accepted: 01/31/2014] [Indexed: 01/25/2023]
Abstract
Aspergillus terreus ATCC 20542 was cultivated in various culture media in order to activate its genome-encoded biosynthetic pathways and explore the secondary metabolic repertoire. In addition to mevinolinic acid (lovastatin) and its precursor monacolin L, a number of other secondary metabolites were found in the analyzed cultures, namely terreic acid, citrinin, (+)-geodin, terrein, and dehydrocurvularin. In contrast to previously described gene clusters responsible for production of lovastatin, monacolin L, (+)-geodin and dehydrocurvularin, the gene clusters of A. terreus associated with the formation of terreic acid, citrinin and terrein still await identification. Putative gene clusters potentially related to citrinin and terreic acid biosynthesis were suggested in the publicly available genome of A. terreus NIH 2624. The functions of putative genes in the previously identified cluster of (+)-geodin biosynthesis were predicted by confronting the annotation results with the proposed biosynthetic pathway and published biochemical studies on the underlying enzymes. Since there were no available data regarding genetic aspects of terrein biosynthesis, the candidate gene cluster potentially responsible for the production of terrein was not suggested.
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Affiliation(s)
- Tomasz Boruta
- Lodz University of Technology, Faculty of Process and Environmental Engineering, Department of Bioprocess Engineering, ul. Wolczanska 213, 90-924 Lodz, Poland.
| | - Marcin Bizukojc
- Lodz University of Technology, Faculty of Process and Environmental Engineering, Department of Bioprocess Engineering, ul. Wolczanska 213, 90-924 Lodz, Poland
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24
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Rabe F, Ajami-Rashidi Z, Doehlemann G, Kahmann R, Djamei A. Degradation of the plant defence hormone salicylic acid by the biotrophic fungus Ustilago maydis. Mol Microbiol 2013; 89:179-88. [PMID: 23692401 DOI: 10.1111/mmi.12269] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/17/2013] [Indexed: 12/01/2022]
Abstract
Salicylic acid (SA) is a key plant defence hormone which plays an important role in local and systemic defence responses against biotrophic pathogens like the smut fungus Ustilago maydis. Here we identified Shy1, a cytoplasmic U. maydis salicylate hydroxylase which has orthologues in the closely related smuts Ustilago hordei and Sporisorium reilianum. shy1 is transcriptionally induced during the biotrophic stages of development but not required for virulence during seedling infection. Shy1 activity is needed for growth on plates with SA as a sole carbon source. The trigger for shy1 transcriptional induction is SA, suggesting the possibility of a SA sensing mechanism in this fungus.
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Affiliation(s)
- Franziska Rabe
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, D-35043, Marburg, Germany
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25
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Alcazar-Fuoli L, Mellado E. Ergosterol biosynthesis in Aspergillus fumigatus: its relevance as an antifungal target and role in antifungal drug resistance. Front Microbiol 2013; 3:439. [PMID: 23335918 PMCID: PMC3541703 DOI: 10.3389/fmicb.2012.00439] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 12/19/2012] [Indexed: 11/13/2022] Open
Abstract
Ergosterol, the major sterol of fungal membranes, is essential for developmental growth and the main target of antifungals that are currently used to treat fatal fungal infections. Emergence of resistance to existing antifungals is a current problem and several secondary resistance mechanisms have been described in Aspergillus fumigatus clinical isolates. A full understanding of ergosterol biosynthetic control therefore appears to be essential for improvement of antifungal efficacy and to prevent antifungal resistance. An ergosterol biosynthesis pathway in A. fumigatus has been proposed with 14 sterol intermediates resulting in ergosterol and another secondary final compound C-24 ethyl sterol. Transcriptomic analysis of the A. fumigatus response to host-imposed stresses or antifungal agents is expanding our understanding of both sterol biosynthesis and the modes of action of antifungal drugs. Ultimately, the identification of new targets for novel drug design, or the study of combinatorial effects of targeting sterol biosynthesis together with other metabolic pathways, is warranted.
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Affiliation(s)
- Laura Alcazar-Fuoli
- Mycology Reference Laboratory, Centro Nacional de Microbiologia, Instituto de Salud Carlos III, Madrid, Spain
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26
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Holesova Z, Jakubkova M, Zavadiakova I, Zeman I, Tomaska L, Nosek J. Gentisate and 3-oxoadipate pathways in the yeast Candida parapsilosis: identification and functional analysis of the genes coding for 3-hydroxybenzoate 6-hydroxylase and 4-hydroxybenzoate 1-hydroxylase. MICROBIOLOGY-SGM 2011; 157:2152-2163. [PMID: 21474535 DOI: 10.1099/mic.0.048215-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The pathogenic yeast Candida parapsilosis degrades various hydroxy derivatives of benzenes and benzoates by the gentisate and 3-oxoadipate pathways. We identified the genes MNX1, MNX2, MNX3, GDX1, HDX1 and FPH1 that code for enzymes involved in these pathways in the complete genome sequence of C. parapsilosis. Next, we demonstrated that MNX1, MNX2, MNX3 and GDX1 are inducible and transcriptionally controlled by hydroxyaromatic substrates present in cultivation media. Our results indicate that MNX1 and MNX2 code for flavoprotein monooxygenases catalysing the first steps in the 3-oxoadipate and gentisate pathways, respectively (i.e. 4-hydroxybenzoate 1-hydroxylase and 3-hydroxybenzoate 6-hydroxylase). Moreover, we found that the two pathways differ by their intracellular localization. The enzymes of the 3-oxoadipate pathway, Mnx1p and Mnx3p, localize predominantly in the cytosol. In contrast, intracellular localization of the components of the gentisate pathway, Mnx2p and Gdx1p, depends on the substrate in the cultivation medium. In cells growing on glucose these proteins localize in the cytosol, whereas in media containing hydroxyaromatic compounds they associate with mitochondria. Finally, we showed that the overexpression of MNX1 or MNX2 increases the tolerance of C. parapsilosis cells to the antifungal drug terbinafine.
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Affiliation(s)
- Zuzana Holesova
- Department of Genetics, Comenius University in Bratislava, Faculty of Natural Sciences, Mlynska dolina B-1, 842 15 Bratislava, Slovak Republic
- Department of Biochemistry, Comenius University in Bratislava, Faculty of Natural Sciences, Mlynska dolina CH-1, 842 15 Bratislava, Slovak Republic
| | - Michaela Jakubkova
- Department of Biochemistry, Comenius University in Bratislava, Faculty of Natural Sciences, Mlynska dolina CH-1, 842 15 Bratislava, Slovak Republic
| | - Ivana Zavadiakova
- Department of Genetics, Comenius University in Bratislava, Faculty of Natural Sciences, Mlynska dolina B-1, 842 15 Bratislava, Slovak Republic
| | - Igor Zeman
- Department of Biochemistry, Comenius University in Bratislava, Faculty of Natural Sciences, Mlynska dolina CH-1, 842 15 Bratislava, Slovak Republic
| | - Lubomir Tomaska
- Department of Genetics, Comenius University in Bratislava, Faculty of Natural Sciences, Mlynska dolina B-1, 842 15 Bratislava, Slovak Republic
| | - Jozef Nosek
- Department of Biochemistry, Comenius University in Bratislava, Faculty of Natural Sciences, Mlynska dolina CH-1, 842 15 Bratislava, Slovak Republic
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27
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Peres NTA, Sanches PR, Falcão JP, Silveira HCS, Paião FG, Maranhão FCA, Gras DE, Segato F, Cazzaniga RA, Mazucato M, Cursino-Santos JR, Aquino-Ferreira R, Rossi A, Martinez-Rossi NM. Transcriptional profiling reveals the expression of novel genes in response to various stimuli in the human dermatophyte Trichophyton rubrum. BMC Microbiol 2010; 10:39. [PMID: 20144196 PMCID: PMC2831883 DOI: 10.1186/1471-2180-10-39] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2009] [Accepted: 02/08/2010] [Indexed: 01/13/2023] Open
Abstract
Background Cutaneous mycoses are common human infections among healthy and immunocompromised hosts, and the anthropophilic fungus Trichophyton rubrum is the most prevalent microorganism isolated from such clinical cases worldwide. The aim of this study was to determine the transcriptional profile of T. rubrum exposed to various stimuli in order to obtain insights into the responses of this pathogen to different environmental challenges. Therefore, we generated an expressed sequence tag (EST) collection by constructing one cDNA library and nine suppression subtractive hybridization libraries. Results The 1388 unigenes identified in this study were functionally classified based on the Munich Information Center for Protein Sequences (MIPS) categories. The identified proteins were involved in transcriptional regulation, cellular defense and stress, protein degradation, signaling, transport, and secretion, among other functions. Analysis of these unigenes revealed 575 T. rubrum sequences that had not been previously deposited in public databases. Conclusion In this study, we identified novel T. rubrum genes that will be useful for ORF prediction in genome sequencing and facilitating functional genome analysis. Annotation of these expressed genes revealed metabolic adaptations of T. rubrum to carbon sources, ambient pH shifts, and various antifungal drugs used in medical practice. Furthermore, challenging T. rubrum with cytotoxic drugs and ambient pH shifts extended our understanding of the molecular events possibly involved in the infectious process and resistance to antifungal drugs.
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Affiliation(s)
- Nalu T A Peres
- Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
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28
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Newland JG, Abdel-Rahman SM. Update on terbinafine with a focus on dermatophytoses. Clin Cosmet Investig Dermatol 2009; 2:49-63. [PMID: 21436968 PMCID: PMC3047923 DOI: 10.2147/ccid.s3690] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Since terbinafine was introduced on the world market 17 years ago, it has become the leading antifungal for the treatment of superficial fungal infections, aided by unique pharmacologic and microbiologic profiles. This article reviews mode of action, antimycotic spectrum and disposition profile of terbinafine. It examines the data, accumulated over 15 years, on the comparative efficacy of terbinafine (vs griseofulvin, itraconazole, fluconazole) in the management of the infections for which it is primarily indicated (eg, dermatophytoses) and provides a brief discussion on its use for the treatment of non-dermatophyte infections. Finally, the available data on the newest topical and systemic formulations are introduced.
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Affiliation(s)
- Jason G Newland
- Division of Infectious Diseases, Children's Mercy Hospitals and Clinics, Kansas City, MO, USA
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Brito-Madurro AG, Prade RA, Madurro JM, Santos MA, Peres NTA, Cursino-Santos JR, Martinez-Rossi NM, Rossi A. A single amino acid substitution in one of the lipases of Aspergillus nidulans confers resistance to the antimycotic drug undecanoic acid. Biochem Genet 2008; 46:557-65. [PMID: 18516670 DOI: 10.1007/s10528-008-9170-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Accepted: 02/28/2008] [Indexed: 11/28/2022]
Abstract
A plausible approach to evaluate the inhibitory action of antifungals is through the investigation of the fungal resistance to these drugs. We describe here the molecular cloning and initial characterization of the A. nidulans lipA gene, where mutation (lipA1) conferred resistance to undecanoic acid, the most fungitoxic fatty acid in the C(7:0)-C(18:0) series. The lipA gene codes for a putative lipase with the sequence consensus GVSIS and WIFGGG as the catalytic signature. Comparison of the wild-type and LIP1 mutant strain nucleotide sequences showed a G --> A change in lipA1 allele, which results in a Glu(214) --> Lys substitution in LipA protein. This ionic charge change in a conserved LipA region, next to its catalytic site, may have altered the catalytic properties of this enzyme resulting in resistance to undecanoic acid.
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Affiliation(s)
- Ana G Brito-Madurro
- Instituto de Química, Universidade Federal de Uberlândia, Uberlandia, Brazil
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Antifungal resistance mechanisms in dermatophytes. Mycopathologia 2008; 166:369-83. [PMID: 18478356 DOI: 10.1007/s11046-008-9110-7] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2007] [Revised: 01/15/2008] [Accepted: 01/30/2008] [Indexed: 01/19/2023]
Abstract
Although fungi do not cause outbreaks or pandemics, the incidence of severe systemic fungal infections has increased significantly, mainly because of the explosive growth in the number of patients with compromised immune system. Thus, drug resistance in pathogenic fungi, including dermatophytes, is gaining importance. The molecular aspects involved in the resistance of dermatophytes to marketed antifungals and other cytotoxic drugs, such as modifications of target enzymes, over-expression of genes encoding ATP-binding cassette (ABC) transporters and stress-response-related proteins are reviewed. Emphasis is placed on the mechanisms used by dermatophytes to overcome the inhibitory action of terbinafine and survival in the host environment. The relevance of identifying new molecular targets, of expanding the understanding about the molecular mechanisms of resistance and of using this information to design new drugs or to modify those that have become ineffective is also discussed.
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Paião FG, Segato F, Cursino-Santos JR, Peres NTA, Martinez-Rossi NM. Analysis of Trichophyton rubrum gene expression in response to cytotoxic drugs. FEMS Microbiol Lett 2007; 271:180-6. [PMID: 17425668 DOI: 10.1111/j.1574-6968.2007.00710.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Suppressive subtractive hybridization was used to isolate transcripts specifically upregulated during Trichophyton rubrum exposure to acriflavin, fluconazole, griseofulvin, terbinafine or undecanoic acid. Macro-array dot-blot and sequencing of 132 clones, which correspond to genes differentially expressed after exposition of T. rubrum to at least one of these cytotoxic drugs, revealed 39 unique genes. Of these, 32 have not been previously described in T. rubrum, representing an increase in the number of T. rubrum genes that have been identified. The upregulation of the novel genes encoding a retrotransposon element, a carboxylic ester hydrolase, a copper resistance-associated P-type ATPase, a DNA mismatch repair protein and a NIMA (never in mitosis A) interactive protein was confirmed by Northern blot.
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Affiliation(s)
- Fernanda G Paião
- Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Brazil
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Fachin AL, Ferreira-Nozawa MS, Maccheroni W, Martinez-Rossi NM. Role of the ABC transporter TruMDR2 in terbinafine, 4-nitroquinoline N-oxide and ethidium bromide susceptibility in Trichophyton rubrum. J Med Microbiol 2006; 55:1093-1099. [PMID: 16849730 DOI: 10.1099/jmm.0.46522-0] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
A single-copy gene, designated TruMDR2, encoding an ATP-binding cassette (ABC) transporter was cloned and sequenced from the dermatophyte Trichophyton rubrum. The ORF of TruMDR2 was 4048 nt and the deduced amino acid sequence showed high homology with ABC transporters involved in drug efflux in other fungi. The encoded ABC protein predicted 12 transmembrane segments (TMSs) and two almost identical nucleotide-binding domains (NBDs) arranged in two halves in a (TMS(6)-NBD)(2) configuration and could be classified as a member of the multidrug-resistance (MDR) class of ABC transporters. Northern blot analyses revealed an increased level of transcription of the TruMDR2 gene when mycelium was exposed to acriflavine, benomyl, ethidium bromide, ketoconazole, chloramphenicol, griseofulvin, fluconazole, imazalil, itraconazole, methotrexate, 4-nitroquinoline N-oxide (4NQO) or tioconazole. Disruption of the TruMDR2 gene rendered the mutant more sensitive to terbinafine, 4NQO and ethidium bromide than the control strain, suggesting that this transporter plays a role in modulating drug susceptibility in T. rubrum.
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Affiliation(s)
- Ana Lúcia Fachin
- Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, 14049-900 Ribeirão Preto, São Paulo, Brazil
| | - Monica S Ferreira-Nozawa
- Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, 14049-900 Ribeirão Preto, São Paulo, Brazil
| | - Walter Maccheroni
- Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, 14049-900 Ribeirão Preto, São Paulo, Brazil
| | - Nilce M Martinez-Rossi
- Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, 14049-900 Ribeirão Preto, São Paulo, Brazil
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Rocha EMF, Gardiner RE, Park S, Martinez-Rossi NM, Perlin DS. A Phe389Leu substitution in ergA confers terbinafine resistance in Aspergillus fumigatus. Antimicrob Agents Chemother 2006; 50:2533-6. [PMID: 16801438 PMCID: PMC1489775 DOI: 10.1128/aac.00187-06] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Replacement of phenylalanine with leucine at position 391 in squalene epoxidase was identified as being responsible for terbinafine resistance in mutants of Aspergillus nidulans. The equivalent mutation was engineered into the ergA gene of Aspergillus fumigatus, resulting in an F389L substitution that also conferred resistance to this pathogenic mold.
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Affiliation(s)
- E M F Rocha
- Public Health Research Institute, International Center for Public Health, Newark, NJ 07103-3535, USA
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Chamilos G, Kontoyiannis DP. Update on antifungal drug resistance mechanisms of Aspergillus fumigatus. Drug Resist Updat 2006; 8:344-58. [PMID: 16488654 DOI: 10.1016/j.drup.2006.01.001] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2005] [Revised: 01/09/2006] [Accepted: 01/11/2006] [Indexed: 10/25/2022]
Abstract
Although the arsenal of agents with anti-Aspergillus activity has expanded over the last decade, mortality due to invasive aspergillosis (IA) remains unacceptably high. Aspergillus fumigatus still accounts for the majority of cases of IA; however less susceptible to antifungals non-fumigatus aspergilli began to emerge. Antifungal drug resistance of Aspergillus might partially account for treatment failures. Recent advances in our understanding of mechanisms of antifungal drug action in Aspergillus, along with the standardization of in vitro susceptibility testing methods, has brought resistance testing to the forefront of clinical mycology. In addition, molecular biology has started to shed light on the mechanisms of resistance of A. fumigatus to azoles and the echinocandins, while genome-based assays show promise for high-throughput screening for genotypic antifungal resistance. Several problems remain, however, in the study of this complex area. Large multicenter clinical studies--point prevalence or longitudinal--to capture the incidence and prevalence of antifungal resistance in A. fumigatus isolates are lacking. Correlation of in vitro susceptibility with clinical outcome and susceptibility breakpoints has not been established. In addition, the issue of cross-resistance between the newer triazoles is of concern. Furthermore, in vitro resistance testing for polyenes and echinocandins is difficult, and their mechanisms of resistance are largely unknown. This review examines challenges in the diagnosis, epidemiology, and mechanisms of antifungal drug resistance in A. fumigatus.
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Affiliation(s)
- G Chamilos
- Department of Infectious Diseases, Infection Control and Employee Health, Unit 402, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
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