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Mathuria A, Ali N, Kataria N, Mani I. Drug repurposing for fungal infections. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2024; 207:59-78. [PMID: 38942545 DOI: 10.1016/bs.pmbts.2024.04.002] [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: 06/30/2024]
Abstract
The rise of multidrug-resistant bacteria is a well-recognized threat to world health, necessitating the implementation of effective treatments. This issue has been identified as a top priority on the global agenda by the World Health Organization. Certain strains, such as Candida glabrata, Candida krusei, Candida lusitaniae, Candida auris, select cryptococcal species, and opportunistic Aspergillus or Fusarium species, have significant intrinsic resistance to numerous antifungal medicines. This inherent resistance and subsequent suboptimal clinical outcomes underscore the critical imperative for enhanced therapeutic alternatives and management protocols. The challenge of effectively treating fungal infections, compounded by the protracted timelines involved in developing novel drugs, underscores the pressing need to explore alternative therapeutic avenues. Among these, drug repurposing emerges as a particularly promising and expeditious solution, providing cost-effective solutions and safety benefits. In the fight against life-threatening resistant fungal infections, the idea of repurposing existing medications has encouraged research into both established and new compounds as a last-resort therapy. This chapter seeks to provide a comprehensive overview of contemporary antifungal drugs, as well as their key resistance mechanisms. Additionally, it seeks to provide insight into the antimicrobial properties of non-traditional drugs, thereby offering a holistic perspective on the evolving landscape of antifungal therapeutics.
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Affiliation(s)
- Anshu Mathuria
- Department of Biochemistry, Sri Venkateswara College, University of Delhi, New Delhi, India
| | - Namra Ali
- Department of Microbiology, Gargi College, University of Delhi, New Delhi, India
| | - Naina Kataria
- Department of Biochemistry, Sri Venkateswara College, University of Delhi, New Delhi, India
| | - Indra Mani
- Department of Microbiology, Gargi College, University of Delhi, New Delhi, India.
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Gnaien M, Maufrais C, Rebai Y, Kallel A, Ma L, Hamouda S, Khalsi F, Meftah K, Smaoui H, Khemiri M, Hadj Fredj S, Bachellier-Bassi S, Najjar I, Messaoud T, Boussetta K, Kallel K, Mardassi H, d’Enfert C, Bougnoux ME, Znaidi S. A gain-of-function mutation in zinc cluster transcription factor Rob1 drives Candida albicans adaptive growth in the cystic fibrosis lung environment. PLoS Pathog 2024; 20:e1012154. [PMID: 38603707 PMCID: PMC11037546 DOI: 10.1371/journal.ppat.1012154] [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: 11/29/2023] [Revised: 04/23/2024] [Accepted: 03/26/2024] [Indexed: 04/13/2024] Open
Abstract
Candida albicans chronically colonizes the respiratory tract of patients with Cystic Fibrosis (CF). It competes with CF-associated pathogens (e.g. Pseudomonas aeruginosa) and contributes to disease severity. We hypothesize that C. albicans undergoes specific adaptation mechanisms that explain its persistence in the CF lung environment. To identify the underlying genetic and phenotypic determinants, we serially recovered 146 C. albicans clinical isolates over a period of 30 months from the sputum of 25 antifungal-naive CF patients. Multilocus sequence typing analyses revealed that most patients were individually colonized with genetically close strains, facilitating comparative analyses between serial isolates. We strikingly observed differential ability to filament and form monospecies and dual-species biofilms with P. aeruginosa among 18 serial isolates sharing the same diploid sequence type, recovered within one year from a pediatric patient. Whole genome sequencing revealed that their genomes were highly heterozygous and similar to each other, displaying a highly clonal subpopulation structure. Data mining identified 34 non-synonymous heterozygous SNPs in 19 open reading frames differentiating the hyperfilamentous and strong biofilm-former strains from the remaining isolates. Among these, we detected a glycine-to-glutamate substitution at position 299 (G299E) in the deduced amino acid sequence of the zinc cluster transcription factor ROB1 (ROB1G299E), encoding a major regulator of filamentous growth and biofilm formation. Introduction of the G299E heterozygous mutation in a co-isolated weak biofilm-former CF strain was sufficient to confer hyperfilamentous growth, increased expression of hyphal-specific genes, increased monospecies biofilm formation and increased survival in dual-species biofilms formed with P. aeruginosa, indicating that ROB1G299E is a gain-of-function mutation. Disruption of ROB1 in a hyperfilamentous isolate carrying the ROB1G299E allele abolished hyperfilamentation and biofilm formation. Our study links a single heterozygous mutation to the ability of C. albicans to better survive during the interaction with other CF-associated microbes and illuminates how adaptive traits emerge in microbial pathogens to persistently colonize and/or infect the CF-patient airways.
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Affiliation(s)
- Mayssa Gnaien
- Institut Pasteur de Tunis, University of Tunis El Manar, Laboratoire de Microbiologie Moléculaire, Vaccinologie et Développement Biotechnologique (LR16IPT01), Tunis, Tunisia
| | - Corinne Maufrais
- Institut Pasteur, Université Paris Cité, INRAE USC2019A, Département Mycologie, Unité Biologie et Pathogénicité Fongiques, Paris, France
- Institut Pasteur, Université Paris Cité, Bioinformatics and Biostatistics Hub, F-75015 Paris, France
| | - Yasmine Rebai
- Institut Pasteur de Tunis, University of Tunis El Manar, Laboratoire de Microbiologie Moléculaire, Vaccinologie et Développement Biotechnologique (LR16IPT01), Tunis, Tunisia
| | - Aicha Kallel
- Institut Pasteur de Tunis, University of Tunis El Manar, Laboratoire de Microbiologie Moléculaire, Vaccinologie et Développement Biotechnologique (LR16IPT01), Tunis, Tunisia
- Hôpital La Rabta, Laboratoire de Parasitologie et de Mycologie, UR17SP03, Tunis, Tunisia
| | - Laurence Ma
- Institut Pasteur, Université Paris Cité, Biomics core facility, Centre de Ressources et Recherche Technologique (C2RT), Paris, France
| | - Samia Hamouda
- Hôpital d’Enfants Béchir Hamza de Tunis, Tunis, Tunisia
| | - Fatma Khalsi
- Hôpital d’Enfants Béchir Hamza de Tunis, Tunis, Tunisia
| | | | - Hanen Smaoui
- Hôpital d’Enfants Béchir Hamza de Tunis, Tunis, Tunisia
| | - Monia Khemiri
- Hôpital d’Enfants Béchir Hamza de Tunis, Tunis, Tunisia
| | | | - Sophie Bachellier-Bassi
- Institut Pasteur, Université Paris Cité, INRAE USC2019A, Département Mycologie, Unité Biologie et Pathogénicité Fongiques, Paris, France
| | - Imène Najjar
- Institut Pasteur, Université Paris Cité, Biomics core facility, Centre de Ressources et Recherche Technologique (C2RT), Paris, France
| | | | | | - Kalthoum Kallel
- Hôpital La Rabta, Laboratoire de Parasitologie et de Mycologie, UR17SP03, Tunis, Tunisia
| | - Helmi Mardassi
- Institut Pasteur de Tunis, University of Tunis El Manar, Laboratoire de Microbiologie Moléculaire, Vaccinologie et Développement Biotechnologique (LR16IPT01), Tunis, Tunisia
| | - Christophe d’Enfert
- Institut Pasteur, Université Paris Cité, INRAE USC2019A, Département Mycologie, Unité Biologie et Pathogénicité Fongiques, Paris, France
| | - Marie-Elisabeth Bougnoux
- Institut Pasteur, Université Paris Cité, INRAE USC2019A, Département Mycologie, Unité Biologie et Pathogénicité Fongiques, Paris, France
| | - Sadri Znaidi
- Institut Pasteur de Tunis, University of Tunis El Manar, Laboratoire de Microbiologie Moléculaire, Vaccinologie et Développement Biotechnologique (LR16IPT01), Tunis, Tunisia
- Institut Pasteur, Université Paris Cité, INRAE USC2019A, Département Mycologie, Unité Biologie et Pathogénicité Fongiques, Paris, France
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Bing J, Guan Z, Zheng T, Ennis CL, Nobile CJ, Chen C, Chu H, Huang G. Rapid evolution of an adaptive multicellular morphology of Candida auris during systemic infection. Nat Commun 2024; 15:2381. [PMID: 38493178 PMCID: PMC10944540 DOI: 10.1038/s41467-024-46786-8] [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: 10/30/2023] [Accepted: 03/08/2024] [Indexed: 03/18/2024] Open
Abstract
Candida auris has become a serious threat to public health. The mechanisms of how this fungal pathogen adapts to the mammalian host are poorly understood. Here we report the rapid evolution of an adaptive C. auris multicellular aggregative morphology in the murine host during systemic infection. C. auris aggregative cells accumulate in the brain and exhibit obvious advantages over the single-celled yeast-form cells during systemic infection. Genetic mutations, specifically de novo point mutations in genes associated with cell division or budding processes, underlie the rapid evolution of this aggregative phenotype. Most mutated C. auris genes are associated with the regulation of cell wall integrity, cytokinesis, cytoskeletal properties, and cellular polarization. Moreover, the multicellular aggregates are notably more recalcitrant to the host antimicrobial peptides LL-37 and PACAP relative to the single-celled yeast-form cells. Overall, to survive in the host, C. auris can rapidly evolve a multicellular aggregative morphology via genetic mutations.
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Affiliation(s)
- Jian Bing
- Shanghai Institute of Infectious Disease and Biosecurity, Department of infectious diseases, Huashan Hospital and State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
- Shanghai Engineering Research Center of Industrial Microorganisms, Shanghai, 200438, China
| | - Zhangyue Guan
- Shanghai Institute of Infectious Disease and Biosecurity, Department of infectious diseases, Huashan Hospital and State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Tianhong Zheng
- Shanghai Institute of Infectious Disease and Biosecurity, Department of infectious diseases, Huashan Hospital and State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Craig L Ennis
- Department of Molecular and Cell Biology, University of California, Merced, Merced, CA, 95343, USA
- Quantitative and Systems Biology Graduate Program, University of California, Merced, Merced, CA, 95343, USA
| | - Clarissa J Nobile
- Department of Molecular and Cell Biology, University of California, Merced, Merced, CA, 95343, USA
- Health Sciences Research Institute, University of California, Merced, Merced, CA, 95343, USA
| | - Changbin Chen
- The Center for Microbes, Development, and Health, Key Laboratory of Molecular Virology and Immunology, Unit of Pathogenic Fungal Infection & Host Immunity, Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Haiqing Chu
- Department of Respiratory and Critical Care Medicine, Shanghai Pulmonary Hospital, School of Medicine, Tongji University, Shanghai, 200433, China.
- Shanghai Key Laboratory of Tuberculosis, Shanghai Pulmonary Hospital, School of Medicine, Tongji University, Shanghai, 200433, China.
| | - Guanghua Huang
- Shanghai Institute of Infectious Disease and Biosecurity, Department of infectious diseases, Huashan Hospital and State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China.
- College of Pharmaceutical Sciences, Southwest University, Chongqing, 400716, China.
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Mould DL, Finger CE, Conaway A, Botelho N, Stuut SE, Hogan DA. Citrate cross-feeding by Pseudomonas aeruginosa supports lasR mutant fitness. mBio 2024; 15:e0127823. [PMID: 38259061 PMCID: PMC10865840 DOI: 10.1128/mbio.01278-23] [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: 05/30/2023] [Accepted: 12/11/2023] [Indexed: 01/24/2024] Open
Abstract
Cross-feeding of metabolites between subpopulations can affect cell phenotypes and population-level behaviors. In chronic Pseudomonas aeruginosa lung infections, subpopulations with loss-of-function (LOF) mutations in the lasR gene are common. LasR, a transcription factor often described for its role in virulence factor expression, also impacts metabolism, which, in turn, affects interactions between LasR+ and LasR- genotypes. Prior transcriptomic analyses suggested that citrate, a metabolite secreted by many cell types, induces virulence factor production when both genotypes are together. An unbiased analysis of the intracellular metabolome revealed broad differences including higher levels of citrate in lasR LOF mutants. Citrate consumption by LasR- strains required the CbrAB two-component system, which relieves carbon catabolite repression and is elevated in lasR LOF mutants. Within mixed communities, the citrate-responsive two-component system TctED and its gene targets OpdH (porin) and TctABC (citrate transporter) that are predicted to be under catabolite repression control were induced and required for enhanced RhlR/I-dependent signaling, pyocyanin production, and fitness of LasR- strains. Citrate uptake by LasR- strains markedly increased pyocyanin production in co-culture with Staphylococcus aureus, which also secretes citrate and frequently co-infects with P. aeruginosa. This citrate-induced restoration of virulence factor production by LasR- strains in communities with diverse species or genotypes may offer an explanation for the contrast observed between the markedly deficient virulence factor production of LasR- strains in monocultures and their association with the most severe forms of cystic fibrosis lung infections. These studies highlight the impact of secreted metabolites in mixed microbial communities.IMPORTANCECross-feeding of metabolites can change community composition, structure, and function. Here, we unravel a cross-feeding mechanism between frequently co-observed isolate genotypes in chronic Pseudomonas aeruginosa lung infections. We illustrate an example of how clonally derived diversity in a microbial communication system enables intra- and inter-species cross-feeding. Citrate, a metabolite released by many cells including P. aeruginosa and Staphylococcus aureus, was differentially consumed between genotypes. Since these two pathogens frequently co-occur in the most severe cystic fibrosis lung infections, the cross-feeding-induced virulence factor expression and fitness described here between diverse genotypes exemplify how co-occurrence can facilitate the development of worse disease outcomes.
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Affiliation(s)
- Dallas L. Mould
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Carson E. Finger
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Amy Conaway
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Nico Botelho
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Stacie E. Stuut
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Deborah A. Hogan
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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Angiolella L, Rojas F, Giammarino A, Bellucci N, Giusiano G. Identification of Virulence Factors in Isolates of Candida haemulonii, Candida albicans and Clavispora lusitaniae with Low Susceptibility and Resistance to Fluconazole and Amphotericin B. Microorganisms 2024; 12:212. [PMID: 38276197 PMCID: PMC10819056 DOI: 10.3390/microorganisms12010212] [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: 12/22/2023] [Revised: 01/15/2024] [Accepted: 01/17/2024] [Indexed: 01/27/2024] Open
Abstract
Emerging life-threatening multidrug-resistant (MDR) species such as the C. haemulonii species complex, Clavispora lusitaniae (sin. C. lusitaniae), and other Candida species are considered as an increasing risk for human health in the near future. (1) Background: Many studies have emphasized that the increase in drug resistance can be associated with several virulence factors in Candida and its knowledge is also essential in developing new antifungal strategies. (2) Methods: Hydrophobicity, adherence, biofilm formation, lipase activity, resistance to osmotic stress, and virulence 'in vivo' on G. mellonella larvae were studied in isolates of C. haemulonii, C. albicans, and C. lusitaniae with low susceptibility and resistance to fluconazole and amphotericin B. (3) Results: Intra- and interspecies variability were observed. C. haemulonii showed high hydrophobicity and the ability to adhere to and form biofilm. C. lusitaniae was less hydrophobic, was biofilm-formation-strain-dependent, and did not show lipase activity. Larvae inoculated with C. albicans isolates displayed significantly higher mortality rates than those infected with C. haemulonii and C. lusitaniae. (4) Conclusions: The ability to adhere to and form biofilms associated with their hydrophobic capacity, to adapt to stress, and to infect within an in vivo model, observed in these non-wild-type Candida and Clavispora isolates, shows their marked virulence features. Since factors that define virulence are related to the development of the resistance of these fungi to the few antifungals available for clinical use, differences in the physiology of these cells must be considered to develop new antifungal therapies.
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Affiliation(s)
- Letizia Angiolella
- Department of Public Health and Infectious Diseases “Sapienza”, University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; (A.G.); (N.B.)
| | - Florencia Rojas
- Departamento de Micología, Instituto de Medicina Regional, Universidad Nacional del Nordeste, CONICET, Resistencia 3500, Argentina; (F.R.); (G.G.)
| | - Andrea Giammarino
- Department of Public Health and Infectious Diseases “Sapienza”, University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; (A.G.); (N.B.)
| | - Nicolò Bellucci
- Department of Public Health and Infectious Diseases “Sapienza”, University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; (A.G.); (N.B.)
| | - Gustavo Giusiano
- Departamento de Micología, Instituto de Medicina Regional, Universidad Nacional del Nordeste, CONICET, Resistencia 3500, Argentina; (F.R.); (G.G.)
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Fan Y, Wu L, Zhai B. The mycobiome: interactions with host and implications in diseases. Curr Opin Microbiol 2023; 75:102361. [PMID: 37527562 DOI: 10.1016/j.mib.2023.102361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 06/29/2023] [Accepted: 07/03/2023] [Indexed: 08/03/2023]
Abstract
Over the past decade, our understanding of the composition and function of the human mucosal surface-associated fungal community (i.e. the mycobiome) has rapidly expanded. Fungi colonize at various sites of the mucosal surface at birth and play important roles in the development and homeostasis of immune system throughout adulthood. Here, we review the recent research progresses in the human mycobiome at different body sites, including the gastrointestinal (GI) tract, the respiratory tract, the urogenital tract, the oral cavity, the skin surface, and the tumor tissues. Researchers have made extensive effort in characterizing the interactions between mycobiome and immune system, especially in the GI tract. We discuss the mycobiome dysbiosis and its implications to the progression of diseases such as inflammatory bowel diseases, alcoholic liver diseases, systemic infections, cancers, and so on, indicating the potential of mycobiome-targeting intervention strategy for life-threatening diseases.
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Affiliation(s)
- Yani Fan
- Clinical laboratory, Shenzhen Bao'an Women's and Children's Hospital, Shenzhen, Guangdong Province, China; Maternal-Fetal Medicine Institute, Shenzhen Bao'an Women's and Children's Hospital, Shenzhen, China; CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Lijuan Wu
- Clinical laboratory, Shenzhen Bao'an Women's and Children's Hospital, Shenzhen, Guangdong Province, China; Maternal-Fetal Medicine Institute, Shenzhen Bao'an Women's and Children's Hospital, Shenzhen, China.
| | - Bing Zhai
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
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Puerner C, Vellanki S, Strauch JL, Cramer RA. Recent Advances in Understanding the Human Fungal Pathogen Hypoxia Response in Disease Progression. Annu Rev Microbiol 2023; 77:403-425. [PMID: 37713457 PMCID: PMC11034785 DOI: 10.1146/annurev-micro-032521-021745] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/17/2023]
Abstract
Fungal-mediated disease progression and antifungal drug efficacy are significantly impacted by the dynamic infection microenvironment. At the site of infection, oxygen often becomes limiting and induces a hypoxia response in both the fungal pathogen and host cells. The fungal hypoxia response impacts several important aspects of fungal biology that contribute to pathogenesis, virulence, antifungal drug susceptibility, and ultimately infection outcomes. In this review, we summarize recent advances in understanding the molecular mechanisms of the hypoxia response in the most common human fungal pathogens, discuss potential therapeutic opportunities, and highlight important areas for future research.
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Affiliation(s)
- Charles Puerner
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA;
| | - Sandeep Vellanki
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA;
| | - Julianne L Strauch
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA;
- Department of Biology, Dartmouth College, Hanover, New Hampshire, USA
| | - Robert A Cramer
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA;
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Murante D, Demers EG, Kurbessoian T, Ruzic M, Ashare A, Stajich JE, Hogan DA. Mrs4 loss of function in fungi during adaptation to the cystic fibrosis lung. mBio 2023; 14:e0117123. [PMID: 37432019 PMCID: PMC10470810 DOI: 10.1128/mbio.01171-23] [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: 05/23/2023] [Accepted: 05/25/2023] [Indexed: 07/12/2023] Open
Abstract
The genetic disease cystic fibrosis (CF) frequently leads to chronic lung infections by bacteria and fungi. We identified three individuals with CF with persistent lung infections dominated by Clavispora (Candida) lusitaniae. Whole-genome sequencing analysis of multiple isolates from each infection found evidence for selection for mutants in the gene MRS4 in all three distinct lung-associated populations. In each population, we found one or two unfixed, non-synonymous mutations in MRS4 relative to the reference allele found in multiple environmental and clinical isolates including the type strain. Genetic and phenotypic analyses found that all evolved alleles led to loss of function (LOF) of Mrs4, a mitochondrial iron transporter. RNA-seq analyses found that Mrs4 variants with decreased activity led to increased expression of genes involved in iron acquisition mechanisms in both low iron and replete iron conditions. Furthermore, surface iron reductase activity and intracellular iron were much higher in strains with Mrs4 LOF variants. Parallel studies found that a subpopulation of a CF-associated Exophiala dermatitidis infection also had a non-synonymous LOF mutation in MRS4. Together, these data suggest that MRS4 mutations may be beneficial during chronic CF lung infections in diverse fungi, perhaps, for the purposes of adaptation to an iron-restricted environment with chronic infections. IMPORTANCE The identification of MRS4 mutations in Clavispora (Candida) lusitaniae and Exophiala dermatitidis in individuals with cystic fibrosis (CF) highlights a possible adaptive mechanism for fungi during chronic CF lung infections. The findings of this study suggest that loss of function of the mitochondrial iron transporter Mrs4 can lead to increased activity of iron acquisition mechanisms, which may be advantageous for fungi in iron-restricted environments during chronic infections. This study provides valuable information for researchers working toward a better understanding of the pathogenesis of chronic lung infections and more effective therapies to treat them.
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Affiliation(s)
- Daniel Murante
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Elora G. Demers
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Tania Kurbessoian
- Department of Microbiology & Plant Pathology and Institute for Integrative Genome Biology, University of California-Riverside, Riverside, California, USA
| | - Marina Ruzic
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Alix Ashare
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
- Department of Medicine, Dartmouth Health, Lebanon, New Hampshire, USA
| | - Jason E. Stajich
- Department of Microbiology & Plant Pathology and Institute for Integrative Genome Biology, University of California-Riverside, Riverside, California, USA
| | - Deborah A. Hogan
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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9
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Scott NE, Edwin Erayil S, Kline SE, Selmecki A. Rapid Evolution of Multidrug Resistance in a Candida lusitaniae Infection during Micafungin Monotherapy. Antimicrob Agents Chemother 2023; 67:e0054323. [PMID: 37428075 PMCID: PMC10433866 DOI: 10.1128/aac.00543-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 06/13/2023] [Indexed: 07/11/2023] Open
Abstract
Candida (Clavispora) lusitaniae is a rare, emerging non-albicans Candida species that can cause life-threatening invasive infections, spread within hospital settings, and rapidly acquire antifungal drug resistance, including multidrug resistance. The frequency and spectrum of mutations causing antifungal drug resistance in C. lusitaniae are poorly understood. Analyses of serial clinical isolates of any Candida species are uncommon and often analyze a limited number of samples collected over months of antifungal therapy with multiple drug classes, limiting the ability to understand relationships between drug classes and specific mutations. Here, we performed comparative genomic and phenotypic analysis of 20 serial C. lusitaniae bloodstream isolates collected daily from an individual patient treated with micafungin monotherapy during a single 11-day hospital admission. We identified isolates with decreased micafungin susceptibility 4 days after initiation of antifungal therapy and a single isolate with increased cross-resistance to micafungin and fluconazole, despite no history of azole therapy in this patient. Only 14 unique single nucleotide polymorphisms (SNPs) were identified between all 20 samples, including three different FKS1 alleles among isolates with decreased micafungin susceptibility and an ERG3 missense mutation found only in the isolate with increased cross-resistance to both micafungin and fluconazole. This is the first clinical evidence of an ERG3 mutation in C. lusitaniae that occurred during echinocandin monotherapy and is associated with cross-resistance to multiple drug classes. Overall, the evolution of multidrug resistance in C. lusitaniae is rapid and can emerge during treatment with only first-line antifungal therapy.
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Affiliation(s)
- Nancy E. Scott
- University of Minnesota, Bioinformatics and Computational Biology Program, Minneapolis, Minnesota, USA
- University of Minnesota, Department of Microbiology and Immunology, Minneapolis, Minnesota, USA
| | - Serin Edwin Erayil
- University of Minnesota Medical School, Department of Medicine, Division of Infectious Diseases and International Medicine, Minneapolis, Minnesota, USA
| | - Susan E. Kline
- University of Minnesota Medical School, Department of Medicine, Division of Infectious Diseases and International Medicine, Minneapolis, Minnesota, USA
| | - Anna Selmecki
- University of Minnesota, Bioinformatics and Computational Biology Program, Minneapolis, Minnesota, USA
- University of Minnesota, Department of Microbiology and Immunology, Minneapolis, Minnesota, USA
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Kurbessoian T, Murante D, Crocker A, Hogan DA, Stajich JE. In host evolution of Exophiala dermatitidis in cystic fibrosis lung micro-environment. G3 (BETHESDA, MD.) 2023; 13:jkad126. [PMID: 37293838 PMCID: PMC10484061 DOI: 10.1093/g3journal/jkad126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 09/26/2022] [Accepted: 05/18/2023] [Indexed: 06/10/2023]
Abstract
Individuals with cystic fibrosis (CF) are susceptible to chronic lung infections that lead to inflammation and irreversible lung damage. While most respiratory infections that occur in CF are caused by bacteria, some are dominated by fungi such as the slow-growing black yeast Exophiala dermatitidis. Here, we analyze isolates of E. dermatitidis cultured from two samples, collected from a single subject 2 years apart. One isolate genome was sequenced using long-read Nanopore technology as an in-population reference to use in comparative single nucleotide polymorphism and insertion-deletion variant analyses of 23 isolates. We then used population genomics and phylo-genomics to compare the isolates to each other as well as the reference genome strain E. dermatitidis NIH/UT8656. Within the CF lung population, three E. dermatitidis clades were detected, each with varying mutation rates. Overall, the isolates were highly similar suggesting that they were recently diverged. All isolates were MAT 1-1, which was consistent with their high relatedness and the absence of evidence for mating or recombination between isolates. Phylogenetic analysis grouped sets of isolates into clades that contained isolates from both early and late time points indicating there are multiple persistent lineages. Functional assessment of variants unique to each clade identified alleles in genes that encode transporters, cytochrome P450 oxidoreductases, iron acquisition, and DNA repair processes. Consistent with the genomic heterogeneity, isolates showed some stable phenotype heterogeneity in melanin production, subtle differences in antifungal minimum inhibitory concentrations, and growth on different substrates. The persistent population heterogeneity identified in lung-derived isolates is an important factor to consider in the study of chronic fungal infections, and the analysis of changes in fungal pathogens over time may provide important insights into the physiology of black yeasts and other slow-growing fungi in vivo.
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Affiliation(s)
- Tania Kurbessoian
- Department of Microbiology and Plant Pathology and Institute of Integrative Genome Biology, University of California Riverside, Riverside, CA 92521, USA
| | - Daniel Murante
- Department of Microbiology and Immunology, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
| | - Alex Crocker
- Department of Microbiology and Immunology, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
| | - Deborah A Hogan
- Department of Microbiology and Immunology, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
| | - Jason E Stajich
- Department of Microbiology and Plant Pathology and Institute of Integrative Genome Biology, University of California Riverside, Riverside, CA 92521, USA
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11
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McMahon CL, Esqueda M, Yu JJ, Wall G, Romo JA, Vila T, Chaturvedi A, Lopez-Ribot JL, Wormley F, Hung CY. Development of an Imaging Flow Cytometry Method for Fungal Cytological Profiling and Its Potential Application in Antifungal Drug Development. J Fungi (Basel) 2023; 9:722. [PMID: 37504711 PMCID: PMC10381375 DOI: 10.3390/jof9070722] [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: 10/13/2022] [Revised: 06/27/2023] [Accepted: 06/29/2023] [Indexed: 07/29/2023] Open
Abstract
Automated imaging techniques have been in increasing demand for the more advanced analysis and efficient characterization of cellular phenotypes. The success of the image-based profiling method hinges on assays that can rapidly and simultaneously capture a wide range of phenotypic features. We have developed an automated image acquisition method for fungal cytological profiling (FCP) using an imaging flow cytometer that can objectively measure over 250 features of a single fungal cell. Fungal cells were labeled with calcofluor white and FM4-64FX, which bind to the cell wall and lipophilic membrane, respectively. Images of single cells were analyzed using IDEAS® software. We first acquired FCPs of fungal cells treated with fluconazole, amphotericin B, and caspofungin, each with a distinct mode of action, to establish FCP databases of profiles associated with specific antifungal treatment. Once fully established, we investigated the potential application of this technique as a screening methodology to identify compounds with novel antifungal activity against Candida albicans and Cryptococcus neoformans. Altogether, we have developed a rapid, powerful, and novel image-profiling method for the phenotypic characterization of fungal cells, also with potential applications in antifungal drug development.
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Affiliation(s)
- Courtney L McMahon
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Marisol Esqueda
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Jieh-Juen Yu
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Gina Wall
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Jesus A Romo
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Taissa Vila
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Ashok Chaturvedi
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Jose L Lopez-Ribot
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Floyd Wormley
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Chiung-Yu Hung
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX 78249, USA
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12
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Daneshnia F, de Almeida Júnior JN, Ilkit M, Lombardi L, Perry AM, Gao M, Nobile CJ, Egger M, Perlin DS, Zhai B, Hohl TM, Gabaldón T, Colombo AL, Hoenigl M, Arastehfar A. Worldwide emergence of fluconazole-resistant Candida parapsilosis: current framework and future research roadmap. THE LANCET. MICROBE 2023; 4:e470-e480. [PMID: 37121240 PMCID: PMC10634418 DOI: 10.1016/s2666-5247(23)00067-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 02/11/2023] [Accepted: 02/15/2023] [Indexed: 05/02/2023]
Abstract
Candida parapsilosis is one of the most commen causes of life-threatening candidaemia, particularly in premature neonates, individuals with cancer of the haematopoietic system, and recipients of organ transplants. Historically, drug-susceptible strains have been linked to clonal outbreaks. However, worldwide studies started since 2018 have reported severe outbreaks among adults caused by fluconazole-resistant strains. Outbreaks caused by fluconazole-resistant strains are associated with high mortality rates and can persist despite strict infection control strategies. The emergence of resistance threatens the efficacy of azoles, which is the most widely used class of antifungals and the only available oral treatment option for candidaemia. The fact that most patients infected with fluconazole-resistant strains are azole-naive underscores the high potential adaptability of fluconazole-resistant strains to diverse hosts, environmental niches, and reservoirs. Another concern is the multidrug-resistant and echinocandin-tolerant C parapsilosis isolates, which emerged in 2020. Raising awareness, establishing effective clinical interventions, and understanding the biology and pathogenesis of fluconazole-resistant C parapsilosis are urgently needed to improve treatment strategies and outcomes.
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Affiliation(s)
- Farnaz Daneshnia
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA; Institute of Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, Netherlands
| | - João N de Almeida Júnior
- Department of Medicine, Division of Infectious Diseases, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil; Clinical Laboratory, Hospital Israelita Albert Einstein, São Paulo, Brazil
| | - Macit Ilkit
- Division of Mycology, Faculty of Medicine, University of Çukurova, Adana, Türkiye
| | - Lisa Lombardi
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Dublin, Ireland
| | - Austin M Perry
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California Merced, Merced, CA, USA; Quantitative and Systems Biology Graduate Program, University of California Merced, Merced, CA, USA
| | - Marilyn Gao
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California Merced, Merced, CA, USA
| | - Clarissa J Nobile
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California Merced, Merced, CA, USA; Health Sciences Research Institute, University of California Merced, Merced, CA, USA
| | - Matthias Egger
- Division of Infectious Diseases, ECMM Excellence Center, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - David S Perlin
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, USA; Department of Medical Sciences, Hackensack School of Medicine, Nutley, NJ, USA; Georgetown University Lombardi Comprehensive Cancer Center, Washington, DC, USA
| | - Bing Zhai
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Tobias M Hohl
- Infectious Disease Service, Department of Medicine and Human Oncology, and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Department of Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Toni Gabaldón
- Life Sciences Programme, Supercomputing Center, Barcelona, Spain; Institute for Research in Biomedicine, Barcelona, Spain; Catalan Institution for Research and Advanced Studies, Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Infecciosas, Barcelona, Spain
| | - Arnaldo Lopes Colombo
- Department of Medicine, Division of Infectious Diseases, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Martin Hoenigl
- Division of Infectious Diseases, ECMM Excellence Center, Department of Internal Medicine, Medical University of Graz, Graz, Austria; Bio TechMed, Graz, Austria; Translational Medical Mycology Research Group, Medical University of Graz, Graz, Austria.
| | - Amir Arastehfar
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA; Department of Medicine, Harvard Medical School, Boston, MA, USA.
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13
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Mould DL, Finger CE, Botelho N, Stuut SE, Hogan DA. Citrate cross-feeding between Pseudomonas aerguinosa genotypes supports lasR mutant fitness. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.30.542973. [PMID: 37398089 PMCID: PMC10312601 DOI: 10.1101/2023.05.30.542973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Across the tree of life, clonal populations-from cancer to chronic bacterial infections - frequently give rise to subpopulations with different metabolic phenotypes. Metabolic exchange or cross-feeding between subpopulations can have profound effects on both cell phenotypes and population-level behavior. In Pseudomonas aeruginosa, subpopulations with loss-of-function mutations in the lasR gene are common. Though LasR is often described for its role in density-dependent virulence factor expression, interactions between genotypes suggest potential metabolic differences. The specific metabolic pathways and regulatory genetics enabling such interactions were previously undescribed. Here, we performed an unbiased metabolomics analysis that revealed broad differences in intracellular metabolomes, including higher levels of intracellular citrate in LasR- strains. We found that while both strains secreted citrate, only LasR- strains, consumed citrate in rich media. Elevated activity of the CbrAB two component system which relieves carbon catabolite repression enabled citrate uptake. Within mixed genotype communities, we found that the citrate responsive two component system TctED and its gene targets OpdH (porin) and TctABC (transporter) required for citrate uptake were induced and required for enhanced RhlR signalling and virulence factor expression in LasR- strains. Enhanced citrate uptake by LasR- strains eliminates differences in RhlR activity between LasR+ and LasR- strains thereby circumventing the sensitivity of LasR- strains to quorum sensing controlled exoproducts. Citrate cross feeding also induces pyocyanin production in LasR- strains co-cultured with Staphylococcus aureus, another species known to secrete biologically-active concentrations of citrate. Metabolite cross feeding may play unrecognized roles in competitive fitness and virulence outcomes when different cell types are together. IMPORTANCE Cross-feeding can change community composition, structure and function. Though cross-feeding has predominantly focused on interactions between species, here we unravel a cross-feeding mechanism between frequently co-observed isolate genotypes of Pseudomonas aeruginosa. Here we illustrate an example of how such clonally-derived metabolic diversity enables intraspecies cross-feeding. Citrate, a metabolite released by many cells including P. aeruginosa, was differentially consumed between genotypes, and this cross-feeding induced virulence factor expression and fitness in genotypes associated with worse disease.
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Affiliation(s)
- Dallas L. Mould
- Geisel School of Medicine at Dartmouth, Department of Microbiology and Immunology, Hanover, NH USA
| | - Carson E. Finger
- Geisel School of Medicine at Dartmouth, Department of Microbiology and Immunology, Hanover, NH USA
| | - Nico Botelho
- Geisel School of Medicine at Dartmouth, Department of Microbiology and Immunology, Hanover, NH USA
| | - Stacie E. Stuut
- Geisel School of Medicine at Dartmouth, Department of Microbiology and Immunology, Hanover, NH USA
| | - Deborah A. Hogan
- Geisel School of Medicine at Dartmouth, Department of Microbiology and Immunology, Hanover, NH USA
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14
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Mould DL, Finger CE, Botelho N, Stuut SE, Hogan DA. Citrate cross-feeding between Pseudomonas aerguinosa genotypes supports lasR mutant fitness. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.30.542962. [PMID: 37398201 PMCID: PMC10312497 DOI: 10.1101/2023.05.30.542962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Across the tree of life, clonal populations-from cancer to chronic bacterial infections - frequently give rise to subpopulations with different metabolic phenotypes. Metabolic exchange or cross-feeding between subpopulations can have profound effects on both cell phenotypes and population-level behavior. In Pseudomonas aeruginosa, subpopulations with loss-of-function mutations in the lasR gene are common. Though LasR is often described for its role in density-dependent virulence factor expression, interactions between genotypes suggest potential metabolic differences. The specific metabolic pathways and regulatory genetics enabling such interactions were previously undescribed. Here, we performed an unbiased metabolomics analysis that revealed broad differences in intracellular metabolomes, including higher levels of intracellular citrate in LasR- strains. We found that while both strains secreted citrate, only LasR- strains, consumed citrate in rich media. Elevated activity of the CbrAB two component system which relieves carbon catabolite repression enabled citrate uptake. Within mixed genotype communities, we found that the citrate responsive two component system TctED and its gene targets OpdH (porin) and TctABC (transporter) required for citrate uptake were induced and required for enhanced RhlR signalling and virulence factor expression in LasR- strains. Enhanced citrate uptake by LasR- strains eliminates differences in RhlR activity between LasR+ and LasR- strains thereby circumventing the sensitivity of LasR- strains to quorum sensing controlled exoproducts. Citrate cross feeding also induces pyocyanin production in LasR- strains co-cultured with Staphylococcus aureus, another species known to secrete biologically-active concentrations of citrate. Metabolite cross feeding may play unrecognized roles in competitive fitness and virulence outcomes when different cell types are together. IMPORTANCE Cross-feeding can change community composition, structure and function. Though cross-feeding has predominantly focused on interactions between species, here we unravel a cross-feeding mechanism between frequently co-observed isolate genotypes of Pseudomonas aeruginosa. Here we illustrate an example of how such clonally-derived metabolic diversity enables intraspecies cross-feeding. Citrate, a metabolite released by many cells including P. aeruginosa, was differentially consumed between genotypes, and this cross-feeding induced virulence factor expression and fitness in genotypes associated with worse disease.
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Affiliation(s)
- Dallas L. Mould
- Geisel School of Medicine at Dartmouth, Department of Microbiology and Immunology, Hanover, NH USA
| | - Carson E. Finger
- Geisel School of Medicine at Dartmouth, Department of Microbiology and Immunology, Hanover, NH USA
| | - Nico Botelho
- Geisel School of Medicine at Dartmouth, Department of Microbiology and Immunology, Hanover, NH USA
| | - Stacie E. Stuut
- Geisel School of Medicine at Dartmouth, Department of Microbiology and Immunology, Hanover, NH USA
| | - Deborah A. Hogan
- Geisel School of Medicine at Dartmouth, Department of Microbiology and Immunology, Hanover, NH USA
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15
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Murante D, Demers EG, Kurbessoian T, Ruzic M, Ashare A, Stajich JE, Hogan DA. Mrs4 loss of function in fungi during adaptation to the cystic fibrosis lung. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.05.535776. [PMID: 37066389 PMCID: PMC10104081 DOI: 10.1101/2023.04.05.535776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
The genetic disease cystic fibrosis (CF) frequently leads to chronic lung infections by bacteria and fungi. We identified three individuals with CF with persistent lung infections dominated by Clavispora ( Candida ) lusitaniae . Whole genome sequencing analysis of multiple isolates from each infection found evidence for selection for mutants in the gene MRS4 in all three distinct lung-associated populations. In each population, we found one or two unfixed, non-synonymous mutations in MRS4 relative to the reference allele found in multiple environmental and clinical isolates including the type strain. Genetic and phenotypic analyses found that all evolved alleles led to loss of function of Mrs4, a mitochondrial iron transporter. RNA Seq analyses found that Mrs4 variants with decreased activity led to increased expression of genes involved in iron acquisition mechanisms in both low iron and replete iron conditions. Furthermore, surface iron reductase activity and intracellular iron was much higher in strains with Mrs4 loss of function variants. Parallel studies found that a subpopulation of a CF-associated Exophiala dermatiditis infection also had a non-synonymous loss of function mutation in MRS4. Together, these data suggest that MRS4 mutations may be beneficial during chronic CF lung infections in diverse fungi perhaps for the purposes of adaptation to an iron restricted environment with chronic infections.
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Affiliation(s)
- Daniel Murante
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Elora G. Demers
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Tania Kurbessoian
- Department of Microbiology & Plant Pathology and Institute for Integrative Genome Biology, University of California-Riverside, Riverside, California, USA
| | - Marina Ruzic
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Alix Ashare
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
- Department of Medicine, Dartmouth Health, Lebanon, NH, USA
| | - Jason E. Stajich
- Department of Microbiology & Plant Pathology and Institute for Integrative Genome Biology, University of California-Riverside, Riverside, California, USA
| | - Deborah A. Hogan
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
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16
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Todd RT, Soisangwan N, Peters S, Kemp B, Crooks T, Gerstein A, Selmecki A. Antifungal Drug Concentration Impacts the Spectrum of Adaptive Mutations in Candida albicans. Mol Biol Evol 2023; 40:6989826. [PMID: 36649220 PMCID: PMC9887641 DOI: 10.1093/molbev/msad009] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 12/06/2022] [Accepted: 01/04/2023] [Indexed: 01/18/2023] Open
Abstract
Invasive fungal infections are a leading global cause of human mortality. Only three major classes of antifungal drugs are widely used, and resistance to all three classes can arise rapidly. The most widely prescribed antifungal drug, fluconazole, disseminates rapidly and reaches a wide range of concentrations throughout the body. The impact of drug concentration on the spectrum and effect of mutations acquired during adaptation is not known for any fungal pathogen, and how the specific level of a given stress influences the distribution of beneficial mutations has been poorly explored in general. We evolved 144 lineages from three genetically distinct clinical isolates of Candida albicans to four concentrations of fluconazole (0, 1, 8, and 64 μg/ml) and performed comprehensive phenotypic and genomic comparisons of ancestral and evolved populations. Adaptation to different fluconazole concentrations resulted in distinct adaptive trajectories. In general, lineages evolved to drug concentrations close to their MIC50 (the level of drug that reduces growth by 50% in the ancestor) tended to rapidly evolve an increased MIC50 and acquired distinct segmental aneuploidies and copy number variations. By contrast, lineages evolved to drug concentrations above their ancestral MIC50 tended to acquire a different suite of mutational changes and increased in drug tolerance (the ability of a subpopulation of cells to grow slowly above their MIC50). This is the first evidence that different concentrations of drug can select for different genotypic and phenotypic outcomes in vitro and may explain observed in vivo drug response variation.
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Affiliation(s)
- Robert T Todd
- Present address: Department of Biology, Bard College, Annandale-on-Hudson, New York
| | | | - Sam Peters
- Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Bailey Kemp
- Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Taylor Crooks
- Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Aleeza Gerstein
- Department of Microbiology, The University of Manitoba, Winnipeg, Manitoba, Canada,Department of Statistics, The University of Manitoba, Winnipeg, Manitoba, Canada
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17
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Todd RT, Selmecki A. Copy Number Variation and Allele Ratio Analysis in Candida albicans Using Whole Genome Sequencing Data. Methods Mol Biol 2023; 2658:105-125. [PMID: 37024698 PMCID: PMC10676714 DOI: 10.1007/978-1-0716-3155-3_8] [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] [Indexed: 04/28/2023]
Abstract
Whole genome sequencing of human fungal pathogens has revolutionized the speed and accuracy in which sequence variants that cause antifungal resistance can be identified. Genome rearrangements resulting in copy number variation (CNV) are a significant source of acquired antifungal drug resistance across diverse fungal species. Some CNVs are transient in nature, while other CNVs are stable and well tolerated even in the absence of antifungal drugs. By visualizing whole genome sequencing read depth as a function of genomic location, CNVs and CNV breakpoints (genomic positions where the copy number changes occur relative to the rest of the genome) are rapidly identified. A similar analysis can be used to visualize allele ratio changes that occur across the genomes of heterozygous fungal species, both in the presence and absence of CNVs. This protocol walks through the bioinformatic analysis of CNVs and allele ratios utilizing free, open-source visualization tools. We provide code to use with an example dataset (matched antifungal drug-sensitive and drug-resistant Candida albicans isolates) and notes on how to expand this protocol to other fungal genomes.
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Affiliation(s)
- Robert T Todd
- Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Anna Selmecki
- Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, MN, USA.
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18
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Martinez-Zurita A, Cuomo CA. Genome-Wide Identification of Variants Associated with Antifungal Drug Resistance. Methods Mol Biol 2023; 2658:81-103. [PMID: 37024697 DOI: 10.1007/978-1-0716-3155-3_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
Abstract
Genomic approaches are widely applied to study the genetic basis of antifungal drug resistance in clinical isolates and experimental studies. Whole-genome sequencing of clinical isolates can comprehensively identify mutations associated with drug resistance and their frequency across fungal populations. In addition, genome comparison of serially collected isolates, such as from patient samples or in vitro drug selection experiments, will identify a small number of changes that can be evaluated for association with drug resistance. Here, we provide a detailed protocol for the computational analysis of genome sequences to identify variants associated with drug resistance.
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Affiliation(s)
- Aina Martinez-Zurita
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Christina A Cuomo
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
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19
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Directed Evolution Detects Supernumerary Centric Chromosomes Conferring Resistance to Azoles in Candida auris. mBio 2022; 13:e0305222. [PMID: 36445083 PMCID: PMC9765433 DOI: 10.1128/mbio.03052-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Candida auris exhibits resistance to multiple antifungal drug classes and sterilization agents, posing threats to the immunocompromised worldwide. Among the four major geographical clades, the East Asian clade 2 isolates of C. auris are mostly drug susceptible. In this study, we experimentally evolved one such drug-susceptible isolate for multiple generations in the presence of the antifungal compound fluconazole and analyzed changes in the karyotype, DNA sequence, and gene expression profiles in three evolved drug-resistant isolates. Next-generation sequencing and electrophoretic karyotyping confirm the presence of segmental aneuploidy as supernumerary chromosomes originating from centromere-inclusive chromosomal duplication events in two such cases. A 638-kb region and a 675-kb region, both of which originated from chromosome 5 and contained its centromere region, are instances of supernumerary chromosome formation identified in two evolved fluconazole-resistant isolates. Loss of the supernumerary chromosomes from the drug-resistant isolates results in a complete reversal of fluconazole susceptibility. Transcriptome analysis of the third isolate identified overexpression of drug efflux pumps as a possible non-aneuploidy-driven mechanism of drug resistance. Together, this study reveals how both aneuploidy-driven and aneuploidy-independent mechanisms may operate in parallel in an evolving population of C. auris in the presence of an antifungal drug, in spite of starting from the same strain grown under similar conditions, to attain various levels of fluconazole resistance. IMPORTANCE Fungal pathogens develop drug resistance through multiple pathways by acquiring gene mutations, increasing the copy number of genes, or altering gene expression. In this study, we attempt to understand the mechanisms of drug resistance in the recently emerged superbug, C. auris. One approach to studying this aspect is identifying various mechanisms operating in drug-resistant clinical isolates. An alternative approach is to evolve a drug-susceptible isolate in the presence of an antifungal compound and trace the changes that result in drug resistance. Here, we evolve a drug-susceptible isolate of C. auris in the laboratory in the presence of a widely used antifungal compound, fluconazole. In addition to the already known changes like overexpression of drug efflux pumps, this study identifies a novel mechanism of azole resistance by the emergence of additional chromosomes through segmental duplication of chromosomal regions, including centromeres. The centric supernumerary chromosome helps stable amplification of a set of genes with an extra copy to confer fluconazole resistance.
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20
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Transcriptional Response of Candida auris to the Mrr1 Inducers Methylglyoxal and Benomyl. mSphere 2022; 7:e0012422. [PMID: 35473297 PMCID: PMC9241502 DOI: 10.1128/msphere.00124-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Candida auris is an urgent threat to human health due to its rapid spread in health care settings and its repeated development of multidrug resistance. Diseases that increase risk for C. auris infection, such as diabetes, kidney failure, or immunocompromising conditions, are associated with elevated levels of methylglyoxal (MG), a reactive dicarbonyl compound derived from several metabolic processes. In other Candida species, expression of MG reductase enzymes that catabolize and detoxify MG are controlled by Mrr1, a multidrug resistance-associated transcription factor, and MG induces Mrr1 activity. Here, we used transcriptomics and genetic assays to determine that C. aurisMRR1a contributes to MG resistance, and that the main Mrr1a targets are an MG reductase and MDR1, which encodes a drug efflux protein. The C. auris Mrr1a regulon is smaller than Mrr1 regulons described in other species. In addition to MG, benomyl (BEN), a known Mrr1 stimulus, induces C. auris Mrr1 activity, and characterization of the MRR1a-dependent and -independent transcriptional responses revealed substantial overlap in genes that were differentially expressed in response to each compound. Additionally, we found that an MRR1 allele specific to one C. auris phylogenetic clade, clade III, encodes a hyperactive Mrr1 variant, and this activity correlated with higher MG resistance. C. aurisMRR1a alleles were functional in Candida lusitaniae and were inducible by BEN, but not by MG, suggesting that the two Mrr1 inducers act via different mechanisms. Together, the data presented in this work contribute to the understanding of Mrr1 activity and MG resistance in C. auris. IMPORTANCECandida auris is a fungal pathogen that has spread since its identification in 2009 and is of concern due to its high incidence of resistance against multiple classes of antifungal drugs. In other Candida species, the transcription factor Mrr1 plays a major role in resistance against azole antifungals and other toxins. More recently, Mrr1 has been recognized to contribute to resistance to methylglyoxal (MG), a toxic metabolic product that is often elevated in different disease states. MG can activate Mrr1 and its induction of Mdr1 which can protect against diverse challenges. The significance of this work lies in showing that MG is also an inducer of Mrr1 in C. auris, and that one of the major pathogenic C. auris lineages has an activating Mrr1 mutation that confers protection against MG.
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Dong P, Zhan Y, Jusuf S, Hui J, Dagher Z, Mansour MK, Cheng J. Photoinactivation of Catalase Sensitizes Candida albicans and Candida auris to ROS-Producing Agents and Immune Cells. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2104384. [PMID: 35119220 PMCID: PMC8981478 DOI: 10.1002/advs.202104384] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 01/07/2022] [Indexed: 06/14/2023]
Abstract
Microbes have developed their own specific strategies to cope with reactive oxygen species (ROS). Catalase, a heme-containing tetramer expressed in a broad range of aerobic fungi, shows remarkable efficiency in degrading hydrogen peroxide (H2 O2 ) for fungal survival and host invasion. Here, it is demonstrated that catalase inactivation by blue light renders fungal cells highly susceptible to ROS attack. To confirm catalase as a major molecular target of blue light, wild type Candida albicans are systematically compared with a catalase-deficient mutant strain regarding their susceptibility to ROS through 410 nm treatment. Upon testing a wide range of fungal species, it is found that intracellular catalase can be effectively and universally inactivated by 410 nm blue light. It is also found that photoinactivation of catalase in combination with ROS-generating agents is highly effective in total eradication of various fungal species, including multiple Candida auris strains, the causative agent of the global fungal epidemic. In addition, photoinactivation of catalase is shown to facilitate macrophage killing of intracellular Candida albicans. The antifungal efficacy of catalase photoinactivation is further validated using a C. albicans-induced mouse model of skin abrasion. Taken together, the findings offer a novel catalase-photoinactivation approach to address multidrug-resistant Candida infections.
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Affiliation(s)
- Pu‐Ting Dong
- Department of Biomedical EngineeringBoston UniversityBostonMA02215USA
- Photonics CenterBoston UniversityBostonMA02215USA
| | - Yuewei Zhan
- Department of Biomedical EngineeringBoston UniversityBostonMA02215USA
- Photonics CenterBoston UniversityBostonMA02215USA
| | - Sebastian Jusuf
- Department of Biomedical EngineeringBoston UniversityBostonMA02215USA
- Photonics CenterBoston UniversityBostonMA02215USA
| | - Jie Hui
- Department of Biomedical EngineeringBoston UniversityBostonMA02215USA
- Photonics CenterBoston UniversityBostonMA02215USA
| | - Zeina Dagher
- Division of Infectious DiseasesMassachusetts General HospitalBostonMA02114USA
- Harvard Medical SchoolBostonMA02115USA
| | - Michael K. Mansour
- Division of Infectious DiseasesMassachusetts General HospitalBostonMA02114USA
- Harvard Medical SchoolBostonMA02115USA
| | - Ji‐Xin Cheng
- Department of Biomedical EngineeringBoston UniversityBostonMA02215USA
- Photonics CenterBoston UniversityBostonMA02215USA
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McDonough LD, Mishra AA, Tosini N, Kakade P, Penumutchu S, Liang SH, Maufrais C, Zhai B, Taur Y, Belenky P, Bennett RJ, Hohl TM, Koh AY, Ene IV. Candida albicans Isolates 529L and CHN1 Exhibit Stable Colonization of the Murine Gastrointestinal Tract. mBio 2021; 12:e0287821. [PMID: 34724818 PMCID: PMC8561340 DOI: 10.1128/mbio.02878-21] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 10/06/2021] [Indexed: 02/06/2023] Open
Abstract
Candida albicans is a pathobiont that colonizes multiple niches in the body including the gastrointestinal (GI) tract but is also responsible for both mucosal and systemic infections. Despite its prevalence as a human commensal, the murine GI tract is generally refractory to colonization with the C. albicans reference isolate SC5314. Here, we identify two C. albicans isolates, 529L and CHN1, that stably colonize the murine GI tract in three different animal facilities under conditions where SC5314 is lost from this niche. Analysis of the bacterial microbiota did not show notable differences among mice colonized with the three C. albicans strains. We compared the genotypes and phenotypes of these three strains and identified thousands of single nucleotide polymorphisms (SNPs) and multiple phenotypic differences, including their ability to grow and filament in response to nutritional cues. Despite striking filamentation differences under laboratory conditions, however, analysis of cell morphology in the GI tract revealed that the three isolates exhibited similar filamentation properties in this in vivo niche. Notably, we found that SC5314 is more sensitive to the antimicrobial peptide CRAMP, and the use of CRAMP-deficient mice modestly increased the ability of SC5314 to colonize the GI tract relative to CHN1 and 529L. These studies provide new insights into how strain-specific differences impact C. albicans traits in the host and advance CHN1 and 529L as relevant strains to study C. albicans pathobiology in its natural host niche. IMPORTANCE Understanding how fungi colonize the GI tract is increasingly recognized as highly relevant to human health. The animal models used to study Candida albicans commensalism commonly rely on altering the host microbiome (via antibiotic treatment or defined diets) to establish successful GI colonization by the C. albicans reference isolate SC5314. Here, we characterize two C. albicans isolates that can colonize the murine GI tract without antibiotic treatment and can therefore be used as tools for studying fungal commensalism. Importantly, experiments were replicated in three different animal facilities and utilized three different mouse strains. Differential colonization between fungal isolates was not associated with alterations in the bacterial microbiome but rather with distinct responses to CRAMP, a host antimicrobial peptide. This work emphasizes the importance of C. albicans intraspecies variation as well as host antimicrobial defense mechanisms in defining the outcome of commensal interactions.
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Affiliation(s)
- Liam D. McDonough
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, USA
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
| | - Animesh A. Mishra
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Nicholas Tosini
- Infectious Disease Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Pallavi Kakade
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, USA
| | - Swathi Penumutchu
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, USA
| | - Shen-Huan Liang
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, USA
| | | | - Bing Zhai
- Infectious Disease Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Ying Taur
- Infectious Disease Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
- Department of Medicine, Weill Cornell Medical College, New York, New York, USA
| | - Peter Belenky
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, USA
| | - Richard J. Bennett
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, USA
| | - Tobias M. Hohl
- Infectious Disease Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York, USA
- Department of Medicine, Weill Cornell Medical College, New York, New York, USA
| | - Andrew Y. Koh
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Harold C. Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Iuliana V. Ene
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, USA
- Department of Mycology, Institut Pasteur, Paris, France
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Participation of the ABC Transporter CDR1 in Azole Resistance of Candida lusitaniae. J Fungi (Basel) 2021; 7:jof7090760. [PMID: 34575798 PMCID: PMC8467326 DOI: 10.3390/jof7090760] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 09/10/2021] [Accepted: 09/13/2021] [Indexed: 11/16/2022] Open
Abstract
Candida lusitaniae is an opportunistic pathogen in humans that causes infrequent but difficult-to-treat diseases. Antifungal drugs are used in the clinic to treat C. lusitaniae infections, however, this fungus can rapidly acquire antifungal resistance to all known antifungal drugs (multidrug resistance). C. lusitaniae acquires azole resistance by gain-of-function (GOF) mutations in the transcriptional regulator MRR1. MRR1 controls the expression of a major facilitator transporter (MFS7) that is important for fluconazole resistance. Here, we addressed the role of the ATP Binding Cassette (ABC) transporter CDR1 as additional mediator of azole resistance in C. lusitaniae. CDR1 expression in isolates with GOF MRR1 mutations was higher compared to wild types, which suggests that CDR1 is an additional (direct or indirect) target of MRR1. CDR1 deletion in the azole-resistant isolate P3 (V688G GOF) revealed that MICs of long-tailed azoles, itraconazole and posaconazole, were decreased compared to P3, which is consistent with the role of this ABC transporter in the efflux of these azoles. Fluconazole MIC was only decreased when CDR1 was deleted in the background of an mfs7Δ mutant from P3, which underpins the dominant role of MFS7 in the resistance of the short-tailed azole fluconazole. With R6G efflux readout as Cdr1 efflux capacity, our data showed that R6G efflux was increased in P3 compared to an azole-susceptible wild type parent, and diminished to background levels in mutant strains lacking CDR1. Milbemycin oxim A3, a known inhibitor of fungal ABC transporters, mimicked efflux phenotypes of cdr1Δ mutants. We therefore provided evidence that CDR1 is an additional mediator of azole resistance in C. lusitaniae, and that CDR1 regulation is dependent on MRR1 and associated GOF mutations.
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Ross BS, Lofgren LA, Ashare A, Stajich JE, Cramer RA. Aspergillus fumigatus In-Host HOG Pathway Mutation for Cystic Fibrosis Lung Microenvironment Persistence. mBio 2021; 12:e0215321. [PMID: 34465017 PMCID: PMC8406193 DOI: 10.1128/mbio.02153-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 07/26/2021] [Indexed: 11/24/2022] Open
Abstract
The prevalence of Aspergillus fumigatus colonization in individuals with cystic fibrosis (CF) and subsequent fungal persistence in the lung is increasingly recognized. However, there is no consensus for clinical management of A. fumigatus in CF individuals, due largely to uncertainty surrounding A. fumigatus CF pathogenesis and virulence mechanisms. To address this gap in knowledge, a longitudinal series of A. fumigatus isolates from an individual with CF were collected over 4.5 years. Isolate genotypes were defined with whole-genome sequencing that revealed both transitory and persistent A. fumigatus in the lung. Persistent lineage isolates grew most readily in a low-oxygen culture environment, and conidia were more sensitive to oxidative stress-inducing conditions than those from nonpersistent isolates. Closely related persistent isolates harbored a unique allele of the high-osmolarity glycerol (HOG) pathway mitogen-activated protein kinase kinase, Pbs2 (pbs2C2). Data suggest this novel pbs2C2 allele arose in vivo and is necessary for the fungal response to osmotic stress in a low-oxygen environment through hyperactivation of the HOG (SakA) signaling pathway. Hyperactivation of the HOG pathway through pbs2C2 comes at the cost of decreased conidial stress resistance in the presence of atmospheric oxygen levels. These novel findings shed light on pathoadaptive mechanisms of A. fumigatus in CF, lay the foundation for identifying persistent A. fumigatus isolates that may require antifungal therapy, and highlight considerations for successful culture of persistent Aspergillus CF isolates. IMPORTANCE Aspergillus fumigatus infection causes a spectrum of clinical manifestations. For individuals with cystic fibrosis (CF), allergic bronchopulmonary aspergillosis (ABPA) is an established complication, but there is a growing appreciation for A. fumigatus airway persistence in CF disease progression. There currently is little consensus for clinical management of A. fumigatus long-term culture positivity in CF. A better understanding of A. fumigatus pathogenesis mechanisms in CF is expected to yield insights into when antifungal therapies are warranted. Here, a 4.5-year longitudinal collection of A. fumigatus isolates from a patient with CF identified a persistent lineage that harbors a unique allele of the Pbs2 mitogen-activated protein kinase kinase (MAPKK) necessary for unique CF-relevant stress phenotypes. Importantly for A. fumigatus CF patient diagnostics, this allele provides increased fitness under CF lung-like conditions at a cost of reduced in vitro growth under standard laboratory conditions. These data illustrate a molecular mechanism for A. fumigatus CF lung persistence with implications for diagnostics and antifungal therapy.
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Affiliation(s)
- Brandon S. Ross
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Lotus A. Lofgren
- Department of Microbiology and Plant Pathology, Institute for Integrative Genome Biology, University of California Riverside, Riverside, California, USA
| | - Alix Ashare
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
- Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Jason E. Stajich
- Department of Microbiology and Plant Pathology, Institute for Integrative Genome Biology, University of California Riverside, Riverside, California, USA
| | - Robert A. Cramer
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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Disseminated Candida lusitaniae: Nosocomial Acquisition Secondary to an Indwelling Urinary Catheter. Case Rep Infect Dis 2021; 2021:6632730. [PMID: 34221522 PMCID: PMC8225443 DOI: 10.1155/2021/6632730] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 05/04/2021] [Accepted: 05/31/2021] [Indexed: 02/04/2023] Open
Abstract
Candida lusitaniae is a rare opportunistic pathogen, and its most common risk factors include immunocompromised patients often with an underlying malignancy. It commonly displays resistance to amphotericin B, and historically, echinocandins have been considered first-line treatment. We present a 77-year-old male with a history of diabetes mellitus. He was treated for cellulitis and discharged to a skilled nursing facility with an indwelling urinary catheter. Despite recommendations from the medicine team to remove the catheter, the patient refused even after discussing the risks and benefits. He returned to the hospital 3 weeks later with symptoms of dysarthria, right-sided facial droop, and right-sided weakness. Ultimately, he was determined to have fungemia and native valve endocarditis due to Candida lusitaniae stemming from his indwelling urinary catheter. He was treated with micafungin, but repeated blood cultures continued to grow C. lusitaniae, and he eventually expired following withdrawal of care. We present this case report to illustrate a rare occurence of Candida lusitaniae in a patient without typical risk factors. C. lusitaniae fungemia is an extremely uncommon disease in patients without underlying malignancy. Despite this lack of apparent, classic risk factors, our patient developed endocarditis of his native valve due to C. lusitaniae fungemia from an indwelling urinary catheter. The ability of this organism to form biofilms, and its rapid mutation rate, makes treating C. lusitaniae very difficult. The treatment of choice for C. lusitaniae endocarditis is surgical intervention due to biofilm formation on the cardiac valves. Medical treatment recommendations are currently fluconazole, which is in contrast to the historical use of echinocandins. Infection due to Candida lusitaniae, though rare, should be remembered by clinicians. This particular fungal agent is especially difficult to treat due to its multiple virulence factors. Additionally, the use of indwelling urinary catheters should only occur when proper indications are present and should be promptly discontinued when their placement is no longer necessary.
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The Interplay Between Neutral and Adaptive Processes Shapes Genetic Variation During Candida Species Evolution. CURRENT CLINICAL MICROBIOLOGY REPORTS 2021. [DOI: 10.1007/s40588-021-00171-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Arastehfar A, Daneshnia F, Hafez A, Khodavaisy S, Najafzadeh MJ, Charsizadeh A, Zarrinfar H, Salehi M, Shahrabadi ZZ, Sasani E, Zomorodian K, Pan W, Hagen F, Ilkit M, Kostrzewa M, Boekhout T. Antifungal susceptibility, genotyping, resistance mechanism, and clinical profile of Candida tropicalis blood isolates. Med Mycol 2021; 58:766-773. [PMID: 31828316 PMCID: PMC7398758 DOI: 10.1093/mmy/myz124] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/14/2019] [Accepted: 12/06/2019] [Indexed: 02/06/2023] Open
Abstract
Candida tropicalis is one of the major candidaemia agents, associated with the highest mortality rates among Candida species, and developing resistance to azoles. Little is known about the molecular mechanisms of azole resistance, genotypic diversity, and the clinical background of C. tropicalis infections. Consequently, this study was designed to address those questions. Sixty-four C. tropicalis bloodstream isolates from 62 patients from three cities in Iran (2014–2019) were analyzed. Strain identification, antifungal susceptibility testing, and genotypic diversity analysis were performed by MALDI-TOF MS, CLSI-M27 A3/S4 protocol, and amplified fragment length polymorphism (AFLP) fingerprinting, respectively. Genes related to drug resistance (ERG11, MRR1, TAC1, UPC2, and FKS1 hotspot9s) were sequenced. The overall mortality rate was 59.6% (37/62). Strains were resistant to micafungin [minimum inhibitory concentration (MIC) ≥1 μg/ml, 2/64], itraconazole (MIC > 0.5 μg/ml, 2/64), fluconazole (FLZ; MIC ≥ 8 μg/ml, 4/64), and voriconazole (MIC ≥ 1 μg/ml, 7/64). Pan-azole and FLZ + VRZ resistance were observed in one and two isolates, respectively, while none of the patients were exposed to azoles. MRR1 (T255P, 647S), TAC1 (N164I, R47Q), and UPC2 (T241A, Q340H, T381S) mutations were exclusively identified in FLZ-resistant isolates. AFLP fingerprinting revealed five major and seven minor genotypes; genotype G4 was predominant in all centers. The increasing number of FLZ-R C. tropicalis blood isolates and acquiring FLZ-R in FLZ-naive patients limit the efficiency of FLZ, especially in developing countries. The high mortality rate warrants reaching a consensus regarding the nosocomial mode of C. tropicalis transmission.
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Affiliation(s)
- Amir Arastehfar
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - Farnaz Daneshnia
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | | | - Sadegh Khodavaisy
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad-Javad Najafzadeh
- Department of Parasitology and Mycology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Arezoo Charsizadeh
- Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Hossein Zarrinfar
- Allergy Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohammadreza Salehi
- Department of infectious diseases and Tropical Medicine, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Zahra Zare Shahrabadi
- Department of Medical Mycology and Parasitology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Elahe Sasani
- Department of Mycology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Kamiar Zomorodian
- Basic Sciences in Infectious Diseases Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Weihua Pan
- Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai 200003, China
| | - Ferry Hagen
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands.,Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.,Laboratory of Medical Mycology, Jining No. 1 People's Hospital, Jining, Shandong, People's Republic of China
| | - Macit Ilkit
- Division of Mycology, Department of Microbiology, Faculty of Medicine, University of Çukurova, Adana, Turkey
| | | | - Teun Boekhout
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands.,Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai 200003, China.,Institute of Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Amsterdam1012 WX, The Netherlands
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Drug Repurposing in Medical Mycology: Identification of Compounds as Potential Antifungals to Overcome the Emergence of Multidrug-Resistant Fungi. Pharmaceuticals (Basel) 2021; 14:ph14050488. [PMID: 34065420 PMCID: PMC8161392 DOI: 10.3390/ph14050488] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/13/2021] [Accepted: 05/18/2021] [Indexed: 02/07/2023] Open
Abstract
Immunodepression, whether due to HIV infection or organ transplantation, has increased human vulnerability to fungal infections. These conditions have created an optimal environment for the emergence of opportunistic infections, which is concomitant to the increase in antifungal resistance. The use of conventional antifungal drugs as azoles and polyenes can lead to clinical failure, particularly in immunocompromised individuals. Difficulties related to treating fungal infections combined with the time required to develop new drugs, require urgent consideration of other therapeutic alternatives. Drug repurposing is one of the most promising and rapid solutions that the scientific and medical community can turn to, with low costs and safety advantages. To treat life-threatening resistant fungal infections, drug repurposing has led to the consideration of well-known and potential molecules as a last-line therapy. The aim of this review is to provide a summary of current antifungal compounds and their main resistance mechanisms, following by an overview of the antifungal activity of non-traditional antimicrobial drugs. We provide their eventual mechanisms of action and the synergistic combinations that improve the activity of current antifungal treatments. Finally, we discuss drug repurposing for the main emerging multidrug resistant (MDR) fungus, including the Candida auris, Aspergillus or Cryptococcus species.
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Demers EG, Stajich JE, Ashare A, Occhipinti P, Hogan DA. Balancing Positive and Negative Selection: In Vivo Evolution of Candida lusitaniae MRR1. mBio 2021; 12:e03328-20. [PMID: 33785623 PMCID: PMC8092287 DOI: 10.1128/mbio.03328-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 02/04/2021] [Indexed: 12/13/2022] Open
Abstract
The evolution of pathogens in response to selective pressures present during chronic infections can influence their persistence and virulence and the outcomes of antimicrobial therapy. Because subpopulations within an infection can be spatially separated and the host environment can fluctuate, an appreciation of the pathways under selection may be most easily revealed through the analysis of numerous isolates from single infections. Here, we continued our analysis of a set of clonally derived Clavispora (Candida) lusitaniae isolates from a single chronic lung infection with a striking enrichment in the number of alleles of MRR1 Genetic and genomic analyses found evidence for repeated acquisition of gain-of-function mutations that conferred constitutive Mrr1 activity. In the same population, there were multiple alleles with both gain-of-function mutations and secondary suppressor mutations that either attenuated or abolished the constitutive activity, suggesting the presence of counteracting selective pressures. Our studies demonstrated trade-offs between high Mrr1 activity, which confers resistance to the antifungal fluconazole, host factors, and bacterial products through its regulation of MDR1, and resistance to hydrogen peroxide, a reactive oxygen species produced in the neutrophilic environment associated with this infection. This inverse correlation between high Mrr1 activity and hydrogen peroxide resistance was observed in multiple Candida species and in serially collected populations from this individual over 3 years. These data lead us to propose that dynamic or variable selective pressures can be reflected in population genomics and that these dynamics can complicate the drug resistance profile of the population.IMPORTANCE Understanding microbial evolution within patients is critical for managing chronic infections and understanding host-pathogen interactions. Here, our analysis of multiple MRR1 alleles in isolates from a single Clavispora (Candida) lusitaniae infection revealed the selection for both high and low Mrr1 activity. Our studies reveal trade-offs between high Mrr1 activity, which confers resistance to the commonly used antifungal fluconazole, host antimicrobial peptides, and bacterial products, and resistance to hydrogen peroxide. This work suggests that spatial or temporal differences within chronic infections can support a large amount of dynamic and parallel evolution and that Mrr1 activity is under both positive and negative selective pressure to balance different traits that are important for microbial survival.
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Affiliation(s)
- Elora G Demers
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Jason E Stajich
- Department of Microbiology & Plant Pathology and Institute for Integrative Genome Biology, University of California-Riverside, Riverside, California, USA
| | - Alix Ashare
- Dartmouth-Hitchcock Medical Center, Section of Pulmonary and Critical Care Medicine, Lebanon, New Hampshire, USA
| | - Patricia Occhipinti
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Deborah A Hogan
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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Is It Time To Kill the Survival Curve? A Case for Disease Progression Factors in Microbial Pathogenesis and Host Defense Research. mBio 2021; 12:mBio.03483-20. [PMID: 33563835 PMCID: PMC7885121 DOI: 10.1128/mbio.03483-20] [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] [Indexed: 01/14/2023] Open
Abstract
The molecular mechanisms of microbial virulence and host defense are most often studied using animal models and Koch's molecular postulates. A common rationale for these types of experiments is to identify therapeutic targets based on the assumption that microbial or host factors that confer extreme animal model survival phenotypes represent critical virulence and host defense factors. Yet null mutant strains of microbial (or host) factors often yield extreme survival curve phenotypes because they fail to establish an infection. The lack of infection and disease establishment prevents true assessment of the given factor's role(s) in disease progression. Here, we posit that the emphasis on extreme survival curve phenotypes in fungal infectious disease models is leading to missed opportunities to identify new fungal and host factors critical for disease progression. We simply do not yet have a sufficient understanding of fungal virulence and host defense mechanisms throughout the temporal course of an infection. We propose that there is a need to develop new approaches and to revisit tried and true methods to define infection site biology beyond the analysis of survival curve phenotypes. To stimulate these new approaches, we propose the (new) terms "disease initiation factor" and "disease progression factor" to distinguish functional roles at distinct temporal stages of an infection and give us targets to foster new discoveries.
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Biermann AR, Demers EG, Hogan DA. Mrr1 regulation of methylglyoxal catabolism and methylglyoxal-induced fluconazole resistance in Candida lusitaniae. Mol Microbiol 2020; 115:116-130. [PMID: 33319423 DOI: 10.1111/mmi.14604] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 08/26/2020] [Accepted: 09/05/2020] [Indexed: 12/11/2022]
Abstract
Transcription factor Mrr1, best known for its regulation of Candida azole resistance genes such as MDR1, regulates other genes that are poorly characterized. Among the other Mrr1-regulated genes are putative methylglyoxal reductases. Methylglyoxal (MG) is a toxic metabolite that is elevated in diabetes, uremia, and sepsis, which are diseases that increase the risk for candidiasis, and MG serves as a regulatory signal in diverse organisms. Our studies in Clavispora lusitaniae, also known as Candida lusitaniae, showed that Mrr1 regulates expression of two paralogous MG reductases, MGD1 and MGD2, and that both participate in MG resistance and MG catabolism. Exogenous MG increased Mrr1-dependent expression of MGD1 and MGD2 as well as expression of MDR1, which encodes an efflux pump that exports fluconazole. MG improved growth in the presence of fluconazole and this was largely Mrr1-dependent with contributions from a secondary transcription factor, Cap1. Increased fluconazole resistance was also observed in mutants lacking Glo1, a Mrr1-independent MG catabolic enzyme. Isolates from other Candida species displayed heterogeneity in MG resistance and MG stimulation of azole resistance. We propose endogenous and host-derived MG can induce MDR1 and other Mrr1-regulated genes causing increased drug resistance, which may contribute to some instances of fungal treatment failure.
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Affiliation(s)
- Amy R Biermann
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Elora G Demers
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Deborah A Hogan
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
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Lv QZ, Ni TJH, Li LP, Li T, Zhang DZ, Jiang YY. A New Antifungal Agent (4-phenyl-1, 3-thiazol-2-yl) Hydrazine Induces Oxidative Damage in Candida albicans. Front Cell Infect Microbiol 2020; 10:578956. [PMID: 33117733 PMCID: PMC7575736 DOI: 10.3389/fcimb.2020.578956] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 09/02/2020] [Indexed: 01/08/2023] Open
Abstract
A gradual rise in immunocompromised patients over past years has led to the increasing incidence of invasive fungal infections. Development of effective fungicides can not only provide new means for clinical treatment, but also reduce the occurrence of fungal resistance. We identified a new antifungal agent (4-phenyl-1, 3-thiazol-2-yl), hydrazine (numbered as 31C) which showed high-efficiency, broad-spectrum and specific activities. The minimum inhibitory concentration of 31C against pathogenic fungi was between 0.0625-4 μg/ml in vitro, while 31C had no obvious cytotoxicity to human umbilical vein endothelial cells with the concentration of 4 μg/ml. In addition, 31C of 0.5 μg/ml could exhibit significant fungicidal activity and inhibit the biofilm formation of C. albicans. In vivo fungal infection model showed that 31C of 10 mg/kg significantly increased the survival rate of Galleria mellonella. Further study revealed that 31C-treatment increased the reactive oxygen species (ROS) in C. albicans and elevated the expression of some genes related to anti-oxidative stress response, including CAP1, CTA1, TRR1, and SODs. Consistently, 31C-induced high levels of intracellular ROS resulted in considerable DNA damage, which played a critical role in antifungal-induced cellular death. The addition of ROS scavengers, such as glutathione (GSH), N-Acetyl-L-cysteine (NAC) or oligomeric proanthocyanidins (OPC), dramatically reduced the antifungal activities of 31C and rescued the 31C-induced filamentation defect. Collectively, these results showed that 31C exhibited strong antifungal activity and induced obvious oxidative damage, which indicated that compounds with a structure similar to 31C may provide new sight for antifungal drug development.
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Affiliation(s)
- Quan-Zhen Lv
- School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Ting-Jun-Hong Ni
- Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Li-Ping Li
- Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Tian Li
- School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Da-Zhi Zhang
- School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Yuan-Ying Jiang
- Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
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Mould DL, Botelho NJ, Hogan DA. Intraspecies Signaling between Common Variants of Pseudomonas aeruginosa Increases Production of Quorum-Sensing-Controlled Virulence Factors. mBio 2020; 11:e01865-20. [PMID: 32843558 PMCID: PMC7448281 DOI: 10.1128/mbio.01865-20] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 07/17/2020] [Indexed: 12/18/2022] Open
Abstract
The opportunistic pathogen Pseudomonas aeruginosa damages hosts through the production of diverse secreted products, many of which are regulated by quorum sensing (QS). The lasR gene, which encodes a central QS regulator, is frequently mutated in clinical isolates from chronic infections, and loss of LasR function (LasR-) generally impairs the activity of downstream QS regulators RhlR and PqsR. We found that in cocultures containing LasR+ and LasR- strains, LasR- strains hyperproduce the RhlR/RhlI-regulated antagonistic factors pyocyanin and rhamnolipids in diverse models and media and in different strain backgrounds. Diffusible QS autoinducers produced by the wild type were not required for this effect. Using transcriptomics, genetics, and biochemical approaches, we uncovered a reciprocal interaction between wild-type and lasR mutant pairs wherein the iron-scavenging siderophore pyochelin produced by the lasR mutant induced citrate release and cross-feeding from the wild type. Citrate, a metabolite often secreted in low iron environments, stimulated RhlR signaling and RhlI levels in LasR-but not in LasR+ strains. These studies reveal the potential for complex interactions between recently diverged, genetically distinct isolates within populations from single chronic infections.IMPORTANCE Coculture interactions between lasR loss-of-function and LasR+ Pseudomonas aeruginosa strains may explain the worse outcomes associated with the presence of LasR- strains. More broadly, this report illustrates how interactions within a genotypically diverse population, similar to those that frequently develop in natural settings, can promote unpredictably high virulence factor production.
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Affiliation(s)
- Dallas L Mould
- Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Nico J Botelho
- Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Deborah A Hogan
- Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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The Rise of Fungi: A Report on the CIFAR Program Fungal Kingdom: Threats & Opportunities Inaugural Meeting. G3-GENES GENOMES GENETICS 2020; 10:1837-1842. [PMID: 32482729 PMCID: PMC7263687 DOI: 10.1534/g3.120.401271] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The first meeting of the CIFAR Fungal Kingdom: Threats & Opportunities research program saw the congregation of experts on fungal biology to address the most pressing threats fungi pose to global health, agriculture, and biodiversity. This report covers the research discussed during the meeting and the advancements made toward mitigating the devastating impact of fungi on plants, animals, and humans.
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Beekman CN, Ene IV. Short-term evolution strategies for host adaptation and drug escape in human fungal pathogens. PLoS Pathog 2020; 16:e1008519. [PMID: 32407384 PMCID: PMC7224449 DOI: 10.1371/journal.ppat.1008519] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Chapman N. Beekman
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, United States of America
| | - Iuliana V. Ene
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, United States of America
- * E-mail:
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Alves R, Barata-Antunes C, Casal M, Brown AJP, Van Dijck P, Paiva S. Adapting to survive: How Candida overcomes host-imposed constraints during human colonization. PLoS Pathog 2020; 16:e1008478. [PMID: 32437438 PMCID: PMC7241708 DOI: 10.1371/journal.ppat.1008478] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Successful human colonizers such as Candida pathogens have evolved distinct strategies to survive and proliferate within the human host. These include sophisticated mechanisms to evade immune surveillance and adapt to constantly changing host microenvironments where nutrient limitation, pH fluctuations, oxygen deprivation, changes in temperature, or exposure to oxidative, nitrosative, and cationic stresses may occur. Here, we review the current knowledge and recent findings highlighting the remarkable ability of medically important Candida species to overcome a broad range of host-imposed constraints and how this directly affects their physiology and pathogenicity. We also consider the impact of these adaptation mechanisms on immune recognition, biofilm formation, and antifungal drug resistance, as these pathogens often exploit specific host constraints to establish a successful infection. Recent studies of adaptive responses to physiological niches have improved our understanding of the mechanisms established by fungal pathogens to evade the immune system and colonize the host, which may facilitate the design of innovative diagnostic tests and therapeutic approaches for Candida infections.
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Affiliation(s)
- Rosana Alves
- Centre of Molecular and Environmental Biology, University of Minho, Campus de Gualtar, Braga, Portugal
- Institute of Science and Innovation for Bio-Sustainability (IB-S) University of Minho, Campus de Gualtar, Braga, Portugal
| | - Cláudia Barata-Antunes
- Centre of Molecular and Environmental Biology, University of Minho, Campus de Gualtar, Braga, Portugal
- Institute of Science and Innovation for Bio-Sustainability (IB-S) University of Minho, Campus de Gualtar, Braga, Portugal
| | - Margarida Casal
- Centre of Molecular and Environmental Biology, University of Minho, Campus de Gualtar, Braga, Portugal
- Institute of Science and Innovation for Bio-Sustainability (IB-S) University of Minho, Campus de Gualtar, Braga, Portugal
| | | | - Patrick Van Dijck
- VIB-KU Leuven Center for Microbiology, Flanders, Belgium
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium
| | - Sandra Paiva
- Centre of Molecular and Environmental Biology, University of Minho, Campus de Gualtar, Braga, Portugal
- Institute of Science and Innovation for Bio-Sustainability (IB-S) University of Minho, Campus de Gualtar, Braga, Portugal
- * E-mail: mailto:
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Wang F, Zhang X, Chen G, Zhao Y. Living Bacterial Microneedles for Fungal Infection Treatment. RESEARCH (WASHINGTON, D.C.) 2020; 2020:2760594. [PMID: 33623902 PMCID: PMC7877375 DOI: 10.34133/2020/2760594] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 10/16/2020] [Indexed: 12/12/2022]
Abstract
Fungal infections are everlasting health challenges all over the world, bringing about great financial and medical burdens. Here, inspired by the natural competition law of beneficial bacteria against other microbes, we present novel living microneedles (LMNs) with functionalized bacteria encapsulation for efficient fungal infection treatment. The chosen beneficial bacterial components, Bacillus subtilis (B. subtilis), which are naturally found on the human skin and widely used for food processing, can get nutrients from the skin and escape from the immune system with the help of microneedles. Besides, the encapsulated B. subtilis can continuously produce and secrete various potential antifungal agents which can directly bind to fungal cell surface-associated proteins and destruct the cell membranes, thus avoiding drug resistance. After immobilization in the LMNs, the bacteria can stay within the LMNs without invasion and the encapsulated bacteria together with microneedles can be removed after application. Thus, the side effects, especially the risk for subsequent bacterial infections, are controlled to a minimum to ensure security. In addition, strong penetrability of the microneedles enhances penetration of antifungal agents, and their heights can be adjusted according to the infected depth to acquire better therapeutic effects. These features make the LMNs potentially valuable for clinical applications.
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Affiliation(s)
- Fengyuan Wang
- Department of Burns & Plastic Surgery, Institute of Translational Medicine, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, China
- Department of Dermatology, Zhongda Hospital, Southeast University, Nanjing 210009, China
| | - Xiaoxuan Zhang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Guopu Chen
- Department of Burns & Plastic Surgery, Institute of Translational Medicine, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, China
| | - Yuanjin Zhao
- Department of Burns & Plastic Surgery, Institute of Translational Medicine, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, China
- Department of Dermatology, Zhongda Hospital, Southeast University, Nanjing 210009, China
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
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Abstract
Antifungal resistance is an inevitable phenomenon when fungal pathogens are exposed to antifungal drugs. These drugs can be grouped in four distinct classes (azoles, candins, polyenes, and pyrimidine analogs) and are used in different clinical settings. Failures in therapy implicate the sequential or combined use of these different drug classes, which can result in some cases in the development of multidrug resistance (MDR). MDR is particularly challenging in the clinic since it drastically reduces possible treatment alternatives. In this study, we report the rapid development of MDR in Candida lusitaniae in a patient, which became resistant to all known antifungal agents used until now in medicine. To understand how MDR developed in C. lusitaniae, whole-genome sequencing followed by comparative genome analysis was undertaken in sequential MDR isolates. This helped to detect all specific mutations linked to drug resistance and explained the different MDR patterns exhibited by the clinical isolates. Multidrug resistance (MDR) has emerged in hospitals due to the use of several agents administered in combination or sequentially to the same individual. We reported earlier MDR in Candida lusitaniae during therapy with amphotericin B (AmB), azoles, and candins. Here, we used comparative genomic approaches between the initial susceptible isolate and 4 other isolates with different MDR profiles. From a total of 18 nonsynonymous single nucleotide polymorphisms (NSS) in genome comparisons with the initial isolate, six could be associated with MDR. One of the single nucleotide polymorphisms (SNPs) occurred in a putative transcriptional activator (MRR1) resulting in a V668G substitution in isolates resistant to azoles and 5-fluorocytosine (5-FC). We demonstrated by genome editing that MRR1 acted by upregulation of MFS7 (a multidrug transporter) in the presence of the V668G substitution. MFS7 itself mediated not only azole resistance but also 5-FC resistance, which represents a novel resistance mechanism for this drug class. Three other distinct NSS occurred in FKS1 (a glucan synthase gene that is targeted by candins) in three candin-resistant isolates. Last, two other NSS in ERG3 and ERG4 (ergosterol biosynthesis) resulting in nonsense mutations were revealed in AmB-resistant isolates, one of which accumulated the two ERG NSS. AmB-resistant isolates lacked ergosterol and exhibited sterol profiles, consistent with ERG3 and ERG4 defects. In conclusion, this genome analysis combined with genetics and metabolomics helped decipher the resistance profiles identified in this clinical case. MDR isolates accumulated six different mutations conferring resistance to all antifungal agents used in medicine. This case study illustrates the capacity of C. lusitaniae to rapidly adapt under drug pressure within the host.
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Mitochondrial dysfunctions trigger the calcium signaling-dependent fungal multidrug resistance. Proc Natl Acad Sci U S A 2019; 117:1711-1721. [PMID: 31811023 DOI: 10.1073/pnas.1911560116] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Drug resistance in fungal pathogens has risen steadily over the past decades due to long-term azole therapy or triazole usage in agriculture. Modification of the drug target protein to prevent drug binding is a major recognized route to induce drug resistance. However, mechanisms for nondrug target-induced resistance remain only loosely defined. Here, we explore the molecular mechanisms of multidrug resistance resulted from an efficient adaptation strategy for survival in drug environments in the human pathogen Aspergillus fumigatus We show that mutants conferring multidrug resistance are linked with mitochondrial dysfunction induced by defects in heme A biosynthesis. Comparison of the gene expression profiles between the drug-resistant mutants and the parental wild-type strain shows that multidrug-resistant transporters, chitin synthases, and calcium-signaling-related genes are significantly up-regulated, while scavenging mitochondrial reactive oxygen species (ROS)-related genes are significantly down-regulated. The up-regulated-expression genes share consensus calcium-dependent serine threonine phosphatase-dependent response elements (the binding sites of calcium-signaling transcription factor CrzA). Accordingly, drug-resistant mutants show enhanced cytosolic Ca2+ transients and persistent nuclear localization of CrzA. In comparison, calcium chelators significantly restore drug susceptibility and increase azole efficacy either in laboratory-derived or in clinic-isolated A. fumigatus strains. Thus, the mitochondrial dysfunction as a fitness cost can trigger calcium signaling and, therefore, globally up-regulate a series of embedding calcineurin-dependent-response-element genes, leading to antifungal resistance. These findings illuminate how fitness cost affects drug resistance and suggest that disruption of calcium signaling might be a promising therapeutic strategy to fight against nondrug target-induced drug resistance.
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Montoya MC, Moye-Rowley WS, Krysan DJ. Candida auris: The Canary in the Mine of Antifungal Drug Resistance. ACS Infect Dis 2019; 5:1487-1492. [PMID: 31369237 DOI: 10.1021/acsinfecdis.9b00239] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Candia auris has rapidly emerged as a fungal pathogen of worldwide importance. Its impact on global health is due in large part to the high frequency of multidrug resistance among C. auris clinical isolates. Although C. auris resistance to amphotericin B is an unusual feature of this organism, its notoriety should also serve as notice that other more commonly encountered fungal pathogens also show multidrug resistance. Here, we review the epidemiology and mechanisms of C. auris resistance and discuss why the emergence of C. auris provides justification for increased research into mechanisms of drug resistance and the development of novel antifungal drugs.
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Affiliation(s)
- Marhiah C. Montoya
- Clinical and Translational Science Institute, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, New York 14642, United States
- Departments of Pediatrics and Microbiology, Carver College of Medicine, University of Iowa, 250 South Grand Avenue, Iowa City, Iowa 52242, United States
| | - W. Scott Moye-Rowley
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, 250 South Grand Avenue, Iowa City, Iowa 52242, United States
| | - Damian J. Krysan
- Departments of Pediatrics and Microbiology, Carver College of Medicine, University of Iowa, 250 South Grand Avenue, Iowa City, Iowa 52242, United States
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Prasad R, Nair R, Banerjee A. Multidrug transporters of Candida species in clinical azole resistance. Fungal Genet Biol 2019; 132:103252. [PMID: 31302289 DOI: 10.1016/j.fgb.2019.103252] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/07/2019] [Accepted: 07/08/2019] [Indexed: 11/30/2022]
Abstract
Over-expression of the human P-glycoprotein (P-gp) in tumor cells is a classic example of an ABC protein serving as a hindrance to effective chemotherapy. The existence of proteins homologous to P-gp in organisms encompassing the entire living kingdom highlights extrusion of drugs as a general mechanism of multidrug resistance. Infections caused by opportunistic human fungal pathogens such as Candida species are very common and has intensified in recent years. The typical hosts, who possess suppressed immune systems due to conditions such as HIV and transplantation surgery etc., are prone to fungal infections. Prolonged chemotherapy induces fungal cells to eventually develop tolerance to most of the antifungals currently in clinical use. Amongst other prominent mechanisms of antifungal resistance such as manipulation of the drug target, rapid efflux achieved through overexpression of multidrug transporters has emerged as a major resistance mechanism for azoles. Herein, the azole-resistant clinical isolates of Candida species utilize a few select efflux pump proteins belonging to the ABC and MFS superfamilies, to deter the toxic accumulation of therapeutic azoles and thus, facilitating cell survival. In this article, we summarize and discuss the clinically relevant mechanisms of azole resistance in Candida albicans and non-albicans Candida (NAC) species, specifically highlighting the role of multidrug efflux proteins in the phenomenon.
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Affiliation(s)
- Rajendra Prasad
- Amity Institute of Integrative Science and Health and Amity Institute of Biotechnology, Amity University Haryana, Gurgaon, Haryana, India.
| | - Remya Nair
- Amity Institute of Integrative Science and Health and Amity Institute of Biotechnology, Amity University Haryana, Gurgaon, Haryana, India
| | - Atanu Banerjee
- Amity Institute of Integrative Science and Health and Amity Institute of Biotechnology, Amity University Haryana, Gurgaon, Haryana, India.
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Sanglard D. Finding the needle in a haystack: Mapping antifungal drug resistance in fungal pathogen by genomic approaches. PLoS Pathog 2019; 15:e1007478. [PMID: 30703166 PMCID: PMC6355021 DOI: 10.1371/journal.ppat.1007478] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Affiliation(s)
- Dominique Sanglard
- Institute of Microbiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- * E-mail:
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