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Ahmady L, Gothwal M, Mukkoli MM, Bari VK. Antifungal drug resistance in Candida: a special emphasis on amphotericin B. APMIS 2024; 132:291-316. [PMID: 38465406 DOI: 10.1111/apm.13389] [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: 06/16/2023] [Accepted: 02/12/2024] [Indexed: 03/12/2024]
Abstract
Invasive fungal infections in humans caused by several Candida species, increased considerably in immunocompromised or critically ill patients, resulting in substantial morbidity and mortality. Candida albicans is the most prevalent species, although the frequency of these organisms varies greatly according to geographic region. Infections with C. albicans and non-albicans Candida species have become more common, especially in the past 20 years, as a result of aging, immunosuppressive medication use, endocrine disorders, malnourishment, extended use of medical equipment, and an increase in immunogenic diseases. Despite C. albicans being the species most frequently associated with human infections, C. glabrata, C. parapsilosis, C. tropicalis, and C. krusei also have been identified. Several antifungal drugs with different modes of action are approved for use in clinical settings to treat fungal infections. However, due to the common eukaryotic structure of humans and fungi, only a limited number of antifungal drugs are available for therapeutic use. Furthermore, drug resistance in Candida species has emerged as a result of the growing use of currently available antifungal drugs against fungal infections. Amphotericin B (AmB), a polyene class of antifungal drugs, is mainly used for the treatment of serious systemic fungal infections. AmB interacts with fungal plasma membrane ergosterol, triggering cellular ion leakage via pore formation, or extracting the ergosterol from the plasma membrane inducing cellular death. AmB resistance is primarily caused by changes in the content or structure of ergosterol. This review summarizes the antifungal drug resistance exhibited by Candida species, with a special focus on AmB.
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Affiliation(s)
- Lailema Ahmady
- Department of Biochemistry, School of Basic Sciences, Central University of Punjab, Bathinda, India
| | - Manisha Gothwal
- Department of Biochemistry, School of Basic Sciences, Central University of Punjab, Bathinda, India
| | | | - Vinay Kumar Bari
- Department of Biochemistry, School of Basic Sciences, Central University of Punjab, Bathinda, India
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Moreau J, Noël T, Point K, Tewes F, Deroche L, Clarhaut J, Fitton-Ouhabi V, Perraud E, Marchand S, Buyck JM, Brunet K. Pan-azole-resistant Meyerozyma guilliermondii clonal isolates harbouring a double F126L and L505F mutation in Erg11. Mycoses 2024; 67:e13704. [PMID: 38429226 DOI: 10.1111/myc.13704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 01/29/2024] [Accepted: 02/02/2024] [Indexed: 03/03/2024]
Abstract
BACKGROUND Meyerozyma guilliermondii is a yeast species responsible for invasive fungal infections. It has high minimum inhibitory concentrations (MICs) to echinocandins, the first-line treatment of candidemia. In this context, azole antifungal agents are frequently used. However, in recent years, a number of azole-resistant strains have been described. Their mechanisms of resistance are currently poorly studied. OBJECTIVE The aim of this study was consequently to understand the mechanisms of azole resistance in several clinical isolates of M. guilliermondii. METHODS Ten isolates of M. guilliermondii and the ATCC 6260 reference strain were studied. MICs of azoles were determined first. Whole genome sequencing of the isolates was then carried out and the mutations identified in ERG11 were expressed in a CTG clade yeast model (C. lusitaniae). RNA expression of ERG11, MDR1 and CDR1 was evaluated by quantitative PCR. A phylogenic analysis was developed and performed on M. guilliermondii isolates. Lastly, in vitro experiments on fitness cost and virulence were carried out. RESULTS Of the ten isolates tested, three showed pan-azole resistance. A combination of F126L and L505F mutations in Erg11 was highlighted in these three isolates. Interestingly, a combination of these two mutations was necessary to confer azole resistance. An overexpression of the Cdr1 efflux pump was also evidenced in one strain. Moreover, the three pan-azole-resistant isolates were shown to be genetically related and not associated with a fitness cost or a lower virulence, suggesting a possible clonal transmission. CONCLUSION In conclusion, this study identified an original combination of ERG11 mutations responsible for pan-azole-resistance in M. guilliermondii. Moreover, we proposed a new MLST analysis for M. guilliermondii that identified possible clonal transmission of pan-azole-resistant strains. Future studies are needed to investigate the distribution of this clone in hospital environment and should lead to the reconsideration of the treatment for this species.
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Affiliation(s)
- Jérémy Moreau
- Université de Poitiers, INSERM U1070 PHAR2, Poitiers, France
| | - Thierry Noël
- Université de Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | - Kévin Point
- Université de Poitiers, INSERM U1070 PHAR2, Poitiers, France
| | - Frédéric Tewes
- Université de Poitiers, INSERM U1070 PHAR2, Poitiers, France
| | - Luc Deroche
- CHU de Poitiers, Service de Virologie, Poitiers, France
| | - Jonathan Clarhaut
- Université de Poitiers, INSERM U1070 PHAR2, Poitiers, France
- CHU de Poitiers, Service de Toxicologie-Pharmacocinétique, Poitiers, France
| | - Valérie Fitton-Ouhabi
- Université de Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | - Estelle Perraud
- CHU de Poitiers, Service de Parasitologie et Mycologie Médicale, Poitiers, France
| | - Sandrine Marchand
- Université de Poitiers, INSERM U1070 PHAR2, Poitiers, France
- CHU de Poitiers, Service de Toxicologie-Pharmacocinétique, Poitiers, France
| | - Julien M Buyck
- Université de Poitiers, INSERM U1070 PHAR2, Poitiers, France
| | - Kévin Brunet
- Université de Poitiers, INSERM U1070 PHAR2, Poitiers, France
- CHU de Poitiers, Service de Parasitologie et Mycologie Médicale, Poitiers, France
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Chow EWL, Song Y, Chen J, Xu X, Wang J, Chen K, Gao J, Wang Y. The transcription factor Rpn4 activates its own transcription and induces efflux pump expression to confer fluconazole resistance in Candida auris. mBio 2023; 14:e0268823. [PMID: 38014938 PMCID: PMC10746192 DOI: 10.1128/mbio.02688-23] [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: 10/03/2023] [Accepted: 10/17/2023] [Indexed: 11/29/2023] Open
Abstract
IMPORTANCE Candida auris is a recently emerged pathogenic fungus of grave concern globally due to its resistance to conventional antifungals. This study takes a whole-genome approach to explore how C. auris overcomes growth inhibition imposed by the common antifungal drug fluconazole. We focused on gene disruptions caused by a "jumping genetic element" called transposon, leading to fluconazole resistance. We identified mutations in two genes, each encoding a component of the Ubr2/Mub1 ubiquitin-ligase complex, which marks the transcription regulator Rpn4 for degradation. When either protein is absent, stable Rpn4 accumulates in the cell. We found that Rpn4 activates the expression of itself as well as the main drug efflux pump gene CDR1 by binding to a PACE element in the promoter. Furthermore, we identified an amino acid change in Ubr2 in many resistant clinical isolates, contributing to Rpn4 stabilization and increased fluconazole resistance.
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Affiliation(s)
- Eve W. L. Chow
- Infectious Diseases Labs, Agency for Science, Technology and Research, Singapore, Singapore
| | - Yabing Song
- School of Life Sciences, Tsinghua University, Beijing, China
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Jinxin Chen
- School of Life Sciences, Tsinghua University, Beijing, China
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xiaoli Xu
- Infectious Diseases Labs, Agency for Science, Technology and Research, Singapore, Singapore
| | - Jianbin Wang
- School of Life Sciences, Tsinghua University, Beijing, China
- Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing, China
| | - Kun Chen
- Translational Medical Center for Stem Cell Therapy, Institute for Regenerative Medicine, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
- Shanghai Key Laboratory of Signaling and Disease Research, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Jiaxin Gao
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yue Wang
- Infectious Diseases Labs, Agency for Science, Technology and Research, Singapore, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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Bohner F, Papp C, Takacs T, Varga M, Szekeres A, Nosanchuk JD, Vágvölgyi C, Tóth R, Gacser A. Acquired Triazole Resistance Alters Pathogenicity-Associated Features in Candida auris in an Isolate-Dependent Manner. J Fungi (Basel) 2023; 9:1148. [PMID: 38132749 PMCID: PMC10744493 DOI: 10.3390/jof9121148] [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: 09/13/2023] [Revised: 11/13/2023] [Accepted: 11/21/2023] [Indexed: 12/23/2023] Open
Abstract
Fluconazole resistance is commonly encountered in Candida auris, and the yeast frequently displays resistance to other standard drugs, which severely limits the number of effective therapeutic agents against this emerging pathogen. In this study, we aimed to investigate the effect of acquired azole resistance on the viability, stress response, and virulence of this species. Fluconazole-, posaconazole-, and voriconazole- resistant strains were generated from two susceptible C. auris clinical isolates (0381, 0387) and compared under various conditions. Several evolved strains became pan-azole-resistant, as well as echinocandin-cross-resistant. While being pan-azole-resistant, the 0381-derived posaconazole-evolved strain colonized brain tissue more efficiently than any other strain, suggesting that fitness cost is not necessarily a consequence of resistance development in C. auris. All 0387-derived evolved strains carried a loss of function mutation (R160S) in BCY1, an inhibitor of the PKA pathway. Sequencing data also revealed that posaconazole treatment can result in ERG3 mutation in C. auris. Despite using the same mechanisms to generate the evolved strains, both genotype and phenotype analysis highlighted that the development of resistance was unique for each strain. Our data suggest that C. auris triazole resistance development is a highly complex process, initiated by several pleiotropic factors.
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Affiliation(s)
- Flora Bohner
- Department of Microbiology, University of Szeged, 6726 Szeged, Hungary; (F.B.); (C.P.); (T.T.); (M.V.); (A.S.); (C.V.)
| | - Csaba Papp
- Department of Microbiology, University of Szeged, 6726 Szeged, Hungary; (F.B.); (C.P.); (T.T.); (M.V.); (A.S.); (C.V.)
| | - Tamas Takacs
- Department of Microbiology, University of Szeged, 6726 Szeged, Hungary; (F.B.); (C.P.); (T.T.); (M.V.); (A.S.); (C.V.)
| | - Mónika Varga
- Department of Microbiology, University of Szeged, 6726 Szeged, Hungary; (F.B.); (C.P.); (T.T.); (M.V.); (A.S.); (C.V.)
| | - András Szekeres
- Department of Microbiology, University of Szeged, 6726 Szeged, Hungary; (F.B.); (C.P.); (T.T.); (M.V.); (A.S.); (C.V.)
| | - Joshua D. Nosanchuk
- Department of Medicine (Infectious Diseases), Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA;
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
| | - Csaba Vágvölgyi
- Department of Microbiology, University of Szeged, 6726 Szeged, Hungary; (F.B.); (C.P.); (T.T.); (M.V.); (A.S.); (C.V.)
| | - Renáta Tóth
- Department of Microbiology, University of Szeged, 6726 Szeged, Hungary; (F.B.); (C.P.); (T.T.); (M.V.); (A.S.); (C.V.)
| | - Attila Gacser
- Department of Microbiology, University of Szeged, 6726 Szeged, Hungary; (F.B.); (C.P.); (T.T.); (M.V.); (A.S.); (C.V.)
- HCEMM-USZ Fungal Pathogens Research Group, Department of Microbiology, University of Szeged, 6726 Szeged, Hungary
- HUN-REN-USZ Pathomechanisms of Fungal Infections Research Group, University of Szeged, 6726 Szeged, Hungary
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5
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Byun SA, Kwon YJ, Lee GY, Choi MJ, Jeong SH, Kim D, Choi MH, Kee SJ, Kim SH, Shin MG, Won EJ, Shin JH. Virulence Traits and Azole Resistance in Korean Candida auris Isolates. J Fungi (Basel) 2023; 9:979. [PMID: 37888235 PMCID: PMC10607439 DOI: 10.3390/jof9100979] [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: 09/12/2023] [Revised: 09/25/2023] [Accepted: 09/27/2023] [Indexed: 10/28/2023] Open
Abstract
We analyzed the virulence traits and azole resistance mechanisms of 104 Candida auris isolates collected from 13 Korean hospitals from 1996 to 2022. Of these 104 isolates, 96 (5 blood and 91 ear isolates) belonged to clade II, and 8 (6 blood and 2 other isolates) belonged to clade I. Fluconazole resistance (minimum inhibitory concentration ≥32 mg/L) was observed in 68.8% of clade II and 25.0% of clade I isolates. All 104 isolates were susceptible to amphotericin B and three echinocandins. In 2022, six clade I isolates indicated the first nosocomial C. auris cluster in Korea. Clade II C. auris isolates exhibited reduced thermotolerance at 42 °C, with diminished in vitro competitive growth and lower virulence in the Galleria mellonella model compared to non-clade II isolates. Of the 66 fluconazole-resistant clade II isolates, several amino acid substitutions were identified: Erg11p in 14 (21.2%), Tac1Ap in 2 (3.0%), Tac1Bp in 62 (93.9%), and Tac1Bp F214S in 33 (50.0%). Although there were a limited number of non-clade II isolates studied, our results suggest that clade II C. auris isolates from Korean hospitals might display lower virulence traits than non-clade II isolates, and their primary fluconazole resistance mechanism is linked to Tac1Bp mutations.
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Affiliation(s)
- Seung A Byun
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju 61469, Republic of Korea
| | - Yong Jun Kwon
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju 61469, Republic of Korea
| | - Ga Yeong Lee
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju 61469, Republic of Korea
| | - Min Ji Choi
- Microbiological Analysis Team, Biometrology Group, Korea Research Institute of Standards and Science (KRISS), Daejeon 34113, Republic of Korea
| | - Seok Hoon Jeong
- Department of Laboratory Medicine, Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Dokyun Kim
- Department of Laboratory Medicine, Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Min Hyuk Choi
- Department of Laboratory Medicine, Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Seung-Jung Kee
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju 61469, Republic of Korea
| | - Soo Hyun Kim
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju 61469, Republic of Korea
| | - Myung Geun Shin
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju 61469, Republic of Korea
| | - Eun Jeong Won
- Department of Laboratory Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea
| | - Jong Hee Shin
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju 61469, Republic of Korea
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Weerasinghe H, Simm C, Djajawi TM, Tedja I, Lo TL, Simpson DS, Shasha D, Mizrahi N, Olivier FAB, Speir M, Lawlor KE, Ben-Ami R, Traven A. Candida auris uses metabolic strategies to escape and kill macrophages while avoiding robust activation of the NLRP3 inflammasome response. Cell Rep 2023; 42:112522. [PMID: 37204928 DOI: 10.1016/j.celrep.2023.112522] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 03/28/2023] [Accepted: 05/01/2023] [Indexed: 05/21/2023] Open
Abstract
Metabolic adaptations regulate the response of macrophages to infection. The contributions of metabolism to macrophage interactions with the emerging fungal pathogen Candida auris are poorly understood. Here, we show that C. auris-infected macrophages undergo immunometabolic reprogramming and increase glycolysis but fail to activate a strong interleukin (IL)-1β cytokine response or curb C. auris growth. Further analysis shows that C. auris relies on its own metabolic capacity to escape from macrophages and proliferate in vivo. Furthermore, C. auris kills macrophages by triggering host metabolic stress through glucose starvation. However, despite causing macrophage cell death, C. auris does not trigger robust activation of the NLRP3 inflammasome. Consequently, inflammasome-dependent responses remain low throughout infection. Collectively, our findings show that C. auris uses metabolic regulation to eliminate macrophages while remaining immunologically silent to ensure its own survival. Thus, our data suggest that host and pathogen metabolism could represent therapeutic targets for C. auris infections.
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Affiliation(s)
- Harshini Weerasinghe
- Infection Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; Centre to Impact AMR, Monash University, Clayton, VIC 3800, Australia
| | - Claudia Simm
- Infection Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; Centre to Impact AMR, Monash University, Clayton, VIC 3800, Australia
| | - Tirta Mario Djajawi
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC 3168, Australia; Department of Molecular and Translational Science, Monash University, Clayton, VIC 3168, Australia
| | - Irma Tedja
- Infection Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; Centre to Impact AMR, Monash University, Clayton, VIC 3800, Australia
| | - Tricia L Lo
- Infection Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; Centre to Impact AMR, Monash University, Clayton, VIC 3800, Australia
| | - Daniel S Simpson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; The Department of Medical Biology, University of Melbourne, Parkville, VIC 3010, Australia
| | - David Shasha
- Infectious Diseases Unit, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel; Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Naama Mizrahi
- Infectious Diseases Unit, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel
| | - Françios A B Olivier
- Infection Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; Centre to Impact AMR, Monash University, Clayton, VIC 3800, Australia; The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia
| | - Mary Speir
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC 3168, Australia; Department of Molecular and Translational Science, Monash University, Clayton, VIC 3168, Australia
| | - Kate E Lawlor
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC 3168, Australia; Department of Molecular and Translational Science, Monash University, Clayton, VIC 3168, Australia
| | - Ronen Ben-Ami
- Infectious Diseases Unit, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel; Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ana Traven
- Infection Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; Centre to Impact AMR, Monash University, Clayton, VIC 3800, Australia.
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Rabaan AA, Eljaaly K, Alfouzan WA, Mutair AA, Alhumaid S, Alfaraj AH, Aldawood Y, Alsaleh AA, Albayat H, Azmi RA, AlKaabi N, Alzahrani SJ, AlBahrani S, Sulaiman T, Alshukairi AN, Abuzaid AA, Garout M, Ahmad R, Muhammad J. Psychogenetic, genetic and epigenetic mechanisms in Candida auris: Role in drug resistance. J Infect Public Health 2023; 16:257-263. [PMID: 36608452 DOI: 10.1016/j.jiph.2022.12.012] [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] [Received: 06/10/2022] [Revised: 10/28/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022] Open
Abstract
In recent years, we are facing the challenge of drug resistance emergence in fungi. The availability of limited antifungals and development of multi-drug resistance in fungal pathogens has become a serious concern in the past years in the health sector. Although several cellular, molecular, and genetic mechanisms have been proposed to explain the drug resistance mechanism in fungi, but a complete understanding of the molecular and genetic mechanisms is still lacking. Besides the genetic mechanism, epigenetic mechanisms are pivotal in the fungal lifecycle and disease biology. However, very little is understood about the role of epigenetic mechanisms in the emergence of multi-drug resistance in fungi, especially in Candida auris (C. auris). The current narrative review summaries the clinical characteristics, genomic organization, and molecular/genetic/epigenetic mechanisms underlying the emergence of drug resistance in C. auris. A very few studies have attempted to evaluate the role of epigenetic mechanisms in C. auris. Furthermore, advanced genetic tools such as the CRISP-Cas9 system can be utilized to elucidate the epigenetic mechanisms and their role in the emergence of multi-drug resistance in C. auris.
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Affiliation(s)
- Ali A Rabaan
- Molecular Diagnostic Laboratory, Johns Hopkins Aramco Healthcare, Dhahran 31311, Saudi Arabia; College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia; Department of Public Health and Nutrition, The University of Haripur, Haripur 22610, Pakistan.
| | - Khalid Eljaaly
- Department of Pharmacy Practice, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia; Pharmacy Practice and Science Department, College of Pharmacy, University of Arizona, Tucson, AZ, USA
| | - Wadha A Alfouzan
- Department of Microbiology, Faculty of Medicine, Kuwait University, Safat 13110, Kuwait; Microbiology Unit, Department of Laboratories, Farwania Hospital, Farwania 85000, Kuwait
| | - Abbas Al Mutair
- Research Center, Almoosa Specialist Hospital, Al-Ahsa 36342, Saudi Arabia; College of Nursing, Princess Norah Bint Abdulrahman University, Riyadh 11564, Saudi Arabia; School of Nursing, Wollongong University, Wollongong, NSW 2522, Australia; Nursing Department, Prince Sultan Military College of Health Sciences, Dhahran 33048, Saudi Arabia
| | - Saad Alhumaid
- Administration of Pharmaceutical Care, Al-Ahsa Health Cluster, Ministry of Health, Al-Ahsa 31982, Saudi Arabia
| | - Amal H Alfaraj
- Pediatric Department, Abqaiq General Hospital, First Eastern Health Cluster, Abqaiq 33261, Saudi Arabia
| | - Yahya Aldawood
- Clinical Laboratory Science Department, Mohammed Al-Mana College for Medical Sciences, Dammam 34222, Saudi Arabia
| | - Abdulmonem A Alsaleh
- Clinical Laboratory Science Department, Mohammed Al-Mana College for Medical Sciences, Dammam 34222, Saudi Arabia
| | - Hawra Albayat
- Infectious Disease Department, King Saud Medical City, Riyadh 7790, Saudi Arabia
| | - Reyouf Al Azmi
- Infection Prevention and Control, Eastern Health Cluster, Dammam 32253, Saudi Arabia
| | - Nawal AlKaabi
- Sheikh Khalifa Medical City, Abu Dhabi Health Services Company (SEHA), Abu Dhabi, 51900, United Arab Emirates; College of Medicine and Health Science, Khalifa University, Abu Dhabi, 127788, United Arab Emirates
| | - Samira J Alzahrani
- Molecular Diagnostic Laboratory, King Fahd Military Medical Complex, Dhahran 31932, Saudi Arabia
| | - Salma AlBahrani
- Infectious Disease Unit, Specialty Internal Medicine, King Fahd Military Medical Complex, Dhahran 31932, Saudi Arabia
| | - Tarek Sulaiman
- Infectious Diseases Section, Medical Specialties Department, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Abeer N Alshukairi
- College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia; Department of Medicine, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia
| | - Abdulmonem A Abuzaid
- Medical Microbiology Department, Security Forces Hospital Programme, Dammam 32314, Saudi Arabia
| | - Mohammed Garout
- Department of Community Medicine and Health Care for Pilgrims, Faculty of Medicine, Umm Al-Qura University, Makkah 21955, Saudi Arabia
| | - Rafiq Ahmad
- Department of Microbiology, The University of Haripur, Haripur 22610, Pakistan
| | - Javed Muhammad
- Department of Microbiology, The University of Haripur, Haripur 22610, Pakistan.
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Rybak JM, Cuomo CA, Rogers PD. The molecular and genetic basis of antifungal resistance in the emerging fungal pathogen Candida auris. Curr Opin Microbiol 2022; 70:102208. [PMID: 36242897 PMCID: PMC10364995 DOI: 10.1016/j.mib.2022.102208] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/30/2022] [Accepted: 09/02/2022] [Indexed: 01/25/2023]
Abstract
Fungal infections are responsible for significant morbidity and mortality. Resistance to the limited number of agents in the antifungal armamentarium among pathogenic fungi represents a growing public health threat. Particularly concerning is the emerging fungal pathogen Candida auris that frequently exhibits resistance to the triazole class of antifungals and amphotericin B, and for which isolates resistant to all of the major antifungal classes have been reported. In this brief review, we provide an overview of what is currently known about the molecular and genetic basis for antifungal resistance in this fungal pathogen.
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Affiliation(s)
- Jeffrey M Rybak
- Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Christina A Cuomo
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - P David Rogers
- Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA.
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Drug Resistance and Evolvability in an Emerging Human Fungal Pathogen. mBio 2022; 13:e0187622. [PMID: 35980032 PMCID: PMC9600676 DOI: 10.1128/mbio.01876-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Over the past decade, Candida auris has emerged as a highly transmissible human fungal pathogen. Because of its ability to transmit between patients in hospitals and its ability to rapidly develop drug resistance, C. auris presents unique challenges. However, at a genetic and genomic level we still understand relatively little about how drug resistance develops in this pathogen. Burrack et al. use experimental evolution and whole-genome sequencing to identify mutations correlated with fluconazole resistance in C. auris. They identify interesting genomic features, including highly plastic subtelomeric regions and whole chromosomal and segmental aneuploidies. Excitingly, they also identify the first example of a hypermutator strain in C. auris. In comparison with the model human fungal pathogen Candida albicans, C. auris is more likely to undergo mutation and less likely to undergo copy number variation in response to drug selection, which may be linked to differences in base ploidy level.
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10
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Genomic Diversity across Candida auris Clinical Isolates Shapes Rapid Development of Antifungal Resistance
In Vitro
and
In Vivo. mBio 2022; 13:e0084222. [PMID: 35862787 PMCID: PMC9426540 DOI: 10.1128/mbio.00842-22] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Antifungal drug resistance and tolerance pose a serious threat to global public health. In the human fungal pathogen, Candida auris, resistance to triazole, polyene, and echinocandin antifungals is rising, resulting in multidrug resistant isolates. Here, we use genome analysis and in vitro evolution of 17 new clinical isolates of C. auris from clades I and IV to determine how quickly resistance mutations arise, the stability of resistance in the absence of drug, and the impact of genetic background on evolutionary trajectories. We evolved each isolate in the absence of drug as well as in low and high concentrations of fluconazole. In just three passages, we observed genomic and phenotypic changes including karyotype alterations, aneuploidy, acquisition of point mutations, and increases in MIC values within the populations. Fluconazole resistance was stable in the absence of drug, indicating little to no fitness cost associated with resistance. Importantly, two isolates substantially increased resistance to ≥256 μg/mL fluconazole. Multiple evolutionary pathways and mutations associated with increased fluconazole resistance occurred simultaneously within the same population. Strikingly, the subtelomeric regions of C. auris were highly dynamic as deletion of multiple genes near the subtelomeres occurred during the three passages in several populations. Finally, we discovered a mutator phenotype in a clinical isolate of C. auris. This isolate had elevated mutation rates compared to other isolates and acquired substantial resistance during evolution in vitro and in vivo supporting that the genetic background of clinical isolates can have a significant effect on evolutionary potential.
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11
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Vaseghi N, Sharifisooraki J, Khodadadi H, Nami S, Safari F, Ahangarkani F, Meis JF, Badali H, Morovati H. Global Prevalence and Subgroup Analyses of Coronavirus Disease (COVID-19) Associated Candida auris infections (CACa): A Systematic Review and Meta-Analysis. Mycoses 2022; 65:683-703. [PMID: 35555921 PMCID: PMC9347948 DOI: 10.1111/myc.13471] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 05/02/2022] [Accepted: 05/10/2022] [Indexed: 11/30/2022]
Abstract
Background Increased hospitalisation rates in the Coronavirus disease 19 (COVID‐19) era lead to a new wave of hospital‐acquired infections such as emerging multidrug‐resistant Candida auris. We aimed to evaluate and estimate the global prevalence of coronavirus‐associated C. auris infection (CACa). Methods We searched related databases between December 2019 and April 2022 for studies that reported data about CACa. Meta‐analysis was performed using MedCalc software version 20.104 according to the DerSimonian and Laird method applying the random‐effects model. We evaluated heterogeneity using the χ2‐based Q statistic (significant for p‐value < .1) and the I2 statistic (>75% indicative of ‘notable’ heterogeneity). Moreover, if possible, an odds ratio (OR) analysis was performed for eligible data. Results Our meta‐analysis includes ten eligible studies, including 1942 patients hospitalised with COVID‐19; 129 were C. auris cases. The overall pooled prevalence of CACa was estimated at 5.7%. The mortality rate of CACa was estimated at 67.849%. Hypertension was the most prevalent comorbidity (59.374%), followed by diabetes mellitus (52.898%) and cardiovascular diseases (31.392%). Men with a prevalence rate of 80.012% were 3.27 (OR) times more prone to getting infected by C. auris. Conclusion We concluded that the prevalence of C. auris infections decreased during the COVID‐19 pandemic and the prevalence gradient changed from Asia to America. Unfortunately, there are many descriptive studies with duplicate content in the field of epidemiology of C. auris infections which are increasing every day. We suggest further non‐descriptive studies to accurately establish the cause‐and‐effect relationships between C. auris and COVID‐19 infections.
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Affiliation(s)
- Narges Vaseghi
- Department of Pathobiology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Joobin Sharifisooraki
- Health Reproductive Research Center, Islamic Azad University, Sari, Mazandaran, Iran
| | - Hossein Khodadadi
- Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Sanam Nami
- Department of Medical Mycology and Parasitology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Fatemeh Safari
- Department of Microbiology, Falavarjan Branch, Islamic Azad University, Isfahan, Iran
| | - Fatemeh Ahangarkani
- Antimicrobial Resistance Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | - Jacques F Meis
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands.,Excellence Center for Medical Mycology, Centre of Expertise, Mycology Radboudumc/Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands.,Bioprocess Engineering and Biotechnology Graduate Program, Federal University of Paraná, Curitiba, Brazil
| | - Hamid Badali
- Department of Molecular Microbiology & Immunology/South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, Texas
| | - Hamid Morovati
- Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.,Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran
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12
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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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13
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Deciphering the Mrr1/Mdr1 Pathway in Azole Resistance of Candida auris. Antimicrob Agents Chemother 2022; 66:e0006722. [PMID: 35343781 DOI: 10.1128/aac.00067-22] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Candida auris is an emerging yeast pathogen with a remarkable ability to develop antifungal resistance, in particular to fluconazole and other azoles. Azole resistance in C. auris was shown to result from different mechanisms, such as mutations in the target gene ERG11 or gain-of-function (GOF) mutations in the transcription factor TAC1b and overexpression of the drug transporter Cdr1. The roles of the transcription factor Mrr1 and of the drug transporter Mdr1 in azole resistance is still unclear. Previous works showed that deletion of MRR1 or MDR1 had no or little impact on azole susceptibility of C. auris. However, an amino acid substitution in Mrr1 (N647T) was identified in most C. auris isolates of clade III that were fluconazole resistant. This study aimed at investigating the role of the transcription factor Mrr1 in azole resistance of C. auris. While the MRR1N647T mutation was always concomitant to hot spot ERG11 mutations, MRR1 deletion in one of these isolates only resulted in a modest decrease of azole MICs. However, introduction of the MRR1N647T mutation in an azole-susceptible C. auris isolate from another clade with wild-type MRR1 and ERG11 alleles resulted in significant increase of fluconazole and voriconazole MICs. We demonstrated that this MRR1 mutation resulted in reduced azole susceptibility via upregulation of the drug transporter MDR1 and not CDR1. In conclusion, this work demonstrates that the Mrr1-Mdr1 axis may contribute to C. auris azole resistance by mechanisms that are independent from ERG11 mutations and from CDR1 upregulation.
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14
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Bravo Ruiz G, Lorenz A. Genetic Transformation of Candida auris via Homology-Directed Repair Using a Standard Lithium Acetate Protocol. Methods Mol Biol 2022; 2517:95-110. [PMID: 35674948 DOI: 10.1007/978-1-0716-2417-3_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: 06/15/2023]
Abstract
Reverse genetics is a particularly powerful tool in non-model organisms with known whole-genome sequences enabling the characterization of gene and, thus, protein function via a mutant phenotype. Reverse genetic approaches require genetic manipulation techniques which often need to be specifically developed for non-model organisms; this can be fraught with difficulties. Here, we describe a genetic transformation protocol for the recently emerged human pathogen Candida auris to target the integration of DNA constructs into genomic locations via homology-directed repair using long flanking homologous sequences (>1 kb). We detail the generation of DNA constructs for gene deletion with dominant drug resistance markers via fusion PCR, the transformation of these constructs into chemically competent C. auris cells, and the confirmation of correct integration by PCR. This strategy can be adapted to deliver DNA constructs other than deletion cassettes, including promoter exchanges and protein tags.
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Affiliation(s)
- Gustavo Bravo Ruiz
- Institute of Medical Sciences (IMS), University of Aberdeen, Aberdeen, UK
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, UK
| | - Alexander Lorenz
- Institute of Medical Sciences (IMS), University of Aberdeen, Aberdeen, UK.
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15
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Ennis CL, Hernday AD, Nobile CJ. A Markerless CRISPR-Mediated System for Genome Editing in Candida auris Reveals a Conserved Role for Cas5 in the Caspofungin Response. Microbiol Spectr 2021; 9:e0182021. [PMID: 34730409 PMCID: PMC8567271 DOI: 10.1128/spectrum.01820-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 10/15/2021] [Indexed: 12/26/2022] Open
Abstract
Candida auris is a multidrug-resistant human fungal pathogen that has recently emerged worldwide. It can cause life-threatening disseminated infections in humans, with mortality rates upwards of 50%. The molecular mechanisms underlying its multidrug resistance and pathogenic properties are largely unknown. Few methods exist for genome editing in C. auris, all of which rely on selectable markers that limit the number of modifications that can be made. Here, we present a markerless CRISPR/Cas9-mediated genome editing system in C. auris. Using this system, we successfully deleted genes of interest and subsequently reconstituted them at their native loci in isolates across all five C. auris clades. This system also enabled us to introduce precision genome edits to create translational fusions and single point mutations. Using Cas5 as a test case for this system, we discovered a conserved role for Cas5 in the caspofungin response between Candida albicans and C. auris. Overall, the development of a system for precise and facile genome editing in C. auris that can allow edits to be made in a high-throughput manner is a major step forward in improving our understanding of this important human fungal pathogen. IMPORTANCE Candida auris is a recently emerged multidrug-resistant fungal pathogen capable of causing life-threatening systemic infections in humans. Few tools are available for genome editing in C. auris. Here, we present a markerless genome editing system for C. auris that relies on CRISPR/Cas9 technology and works to modify the genomes of all known C. auris clades. Using this system, we discovered a conserved role for Cas5 in the caspofungin response between C. albicans and C. auris. Overall, the development of a system for facile genome editing in C. auris is a major step forward in improving our understanding of this important human fungal pathogen.
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Affiliation(s)
- Craig L. Ennis
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, California, USA
- Quantitative and Systems Biology Graduate Program, University of California, Merced, California, USA
- Health Sciences Research Institute, University of California, Merced, California, USA
| | - Aaron D. Hernday
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, California, USA
- Health Sciences Research Institute, University of California, Merced, California, USA
| | - Clarissa J. Nobile
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, California, USA
- Health Sciences Research Institute, University of California, Merced, California, USA
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16
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Forward and reverse genetic dissection of morphogenesis identifies filament-competent Candida auris strains. Nat Commun 2021; 12:7197. [PMID: 34893621 PMCID: PMC8664941 DOI: 10.1038/s41467-021-27545-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 11/29/2021] [Indexed: 12/19/2022] Open
Abstract
Candida auris is an emerging healthcare-associated pathogen of global concern. Recent reports have identified C. auris isolates that grow in cellular aggregates or filaments, often without a clear genetic explanation. To investigate the regulation of C. auris morphogenesis, we applied an Agrobacterium-mediated transformation system to all four C. auris clades. We identified aggregating mutants associated with disruption of chitin regulation, while disruption of ELM1 produced a polarized, filamentous growth morphology. We developed a transiently expressed Cas9 and sgRNA system for C. auris that significantly increased targeted transformation efficiency across the four C. auris clades. Using this system, we confirmed the roles of C. auris morphogenesis regulators. Morphogenic mutants showed dysregulated chitinase expression, attenuated virulence, and altered antifungal susceptibility. Our findings provide insights into the genetic regulation of aggregating and filamentous morphogenesis in C. auris. Furthermore, the genetic tools described here will allow for efficient manipulation of the C. auris genome. Some isolates of the emerging fungal pathogen Candida auris can form cellular aggregates or filaments. Here, Santana and O’Meara use Agrobacterium-mediated transformation and a CRISPR-Cas9 system to identify several genes that regulate C. auris morphogenesis.
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17
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Ciurea CN, Mare AD, Kosovski IB, Toma F, Vintilă C, Man A. Candida auris and other phylogenetically related species - a mini-review of the literature. Germs 2021; 11:441-448. [PMID: 34722366 DOI: 10.18683/germs.2021.1281] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 06/11/2021] [Accepted: 06/27/2021] [Indexed: 12/30/2022]
Abstract
The lesser-known non-albicans Candida species are often overlooked and difficult to diagnose in most microbiology laboratories. Candida auris, a relatively newly discovered species, is responsible for outbreaks in various geographical regions. Because of its increased resistance to antifungal drugs, C. auris is responsible for hard-to-treat infections and its pathogenicity is still incompletely elucidated. Non-albicans species phylogenetically related to C. auris, like the C. haemulonii complex might also play a role in human pathology. The current summary of the literature presents the emergence, virulence, laboratory identification, and molecular mechanisms responsible for antifungal resistance of emergent rare non-albicans Candida species.
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Affiliation(s)
- Cristina Nicoleta Ciurea
- MD, Department of Microbiology, George Emil Palade University of Medicine, Pharmacy, Science and Technology, Doctoral School, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Târgu Mureş, 38 Gheorghe Marinescu Street, 540139 Târgu Mureş, Romania
| | - Anca Delia Mare
- MD, PhD, Department of Microbiology, George Emil Palade University of Medicine, Pharmacy, Science and Technology, 38 Gheorghe Marinescu Street, 540149 Târgu Mureş, Romania
| | - Irina-Bianca Kosovski
- MD, Department of Pathophysiology, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Târgu Mureş, 38 Gheorghe Marinescu Street, 540139 Târgu Mureş, Romania
| | - Felicia Toma
- MD, PhD, Department of Microbiology, George Emil Palade University of Medicine, Pharmacy, Science and Technology, 540149 Târgu Mureş, 38 Gheorghe Marinescu Street, Romania
| | - Camelia Vintilă
- MD, PhD, Mureş County Clinical Hospital - Infectious Diseases Laboratory, 6 Bernady Gyorgy Street, 540072, Târgu Mureş, Romania
| | - Adrian Man
- MD, PhD, Department of Microbiology, George Emil Palade University of Medicine, Pharmacy, Science and Technology, 540149 Târgu Mureş, Romania
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18
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Impact of Erg11 amino acid substitutions identified in Candida auris clade III isolates on triazole drug susceptibility. Antimicrob Agents Chemother 2021; 66:e0162421. [PMID: 34633842 DOI: 10.1128/aac.01624-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
ERG11 sequencing of 28 Candida auris clade III isolates revealed the presence of concomitant V125A and F126L substitutions. Heterologous expression of Erg11-V125A/F126L in Saccharomyces cerevisiae led to reduced fluconazole and voriconazole susceptibilities. Generation of single substitution gene variants through site-directed mutagenesis uncovered that F126L primarily contributes to the elevated triazole MICs. A similar, yet diminished pattern of reduced susceptibility was observed with long-tailed triazoles posaconazole and itraconazole for V125A/F126L, F126L, Y132F, and K143R alleles.
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19
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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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20
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Muñoz JF, Welsh RM, Shea T, Batra D, Gade L, Howard D, Rowe LA, Meis JF, Litvintseva AP, Cuomo CA. Clade-specific chromosomal rearrangements and loss of subtelomeric adhesins in Candida auris. Genetics 2021; 218:iyab029. [PMID: 33769478 PMCID: PMC8128392 DOI: 10.1093/genetics/iyab029] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [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: 02/10/2021] [Indexed: 12/17/2022] Open
Abstract
Candida auris is an emerging fungal pathogen of rising concern due to global spread, the ability to cause healthcare-associated outbreaks, and antifungal resistance. Genomic analyses revealed that early contemporaneously detected cases of C. auris were geographically stratified into four major clades. While Clades I, III, and IV are responsible for ongoing outbreaks of invasive and multidrug-resistant infections, Clade II, also termed the East Asian clade, consists primarily of cases of ear infection, is often susceptible to all antifungal drugs, and has not been associated with outbreaks. Here, we generate chromosome-level assemblies of twelve isolates representing the phylogenetic breadth of these four clades and the only isolate described to date from Clade V. This Clade V genome is highly syntenic with those of Clades I, III, and IV, although the sequence is highly divergent from the other clades. Clade II genomes appear highly rearranged, with translocations occurring near GC-poor regions, and large subtelomeric deletions in most chromosomes, resulting in a substantially different karyotype. Rearrangements and deletion lengths vary across Clade II isolates, including two from a single patient, supporting ongoing genome instability. Deleted subtelomeric regions are enriched in Hyr/Iff-like cell-surface proteins, novel candidate cell wall proteins, and an ALS-like adhesin. Cell wall proteins from these families and other drug-related genes show clade-specific signatures of selection in Clades I, III, and IV. Subtelomeric dynamics and the conservation of cell surface proteins in the clades responsible for global outbreaks causing invasive infections suggest an explanation for the different phenotypes observed between clades.
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Affiliation(s)
- José F Muñoz
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Rory M Welsh
- Mycotic Diseases Branch, U.S. Department of Health and Human Services, Atlanta, GA, USA
| | - Terrance Shea
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Dhwani Batra
- Division of Scientific Resources, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, GA, USA
| | - Lalitha Gade
- Mycotic Diseases Branch, U.S. Department of Health and Human Services, Atlanta, GA, USA
| | - Dakota Howard
- Division of Scientific Resources, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, GA, USA
| | - Lori A Rowe
- Division of Scientific Resources, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, GA, USA
| | - Jacques F Meis
- Department of Medical Microbiology and Infectious Diseases, Canisius Wilhelmina Hospital, Center of Expertise in Mycology Radboudumc/CWZ, Nijmegen, The Netherlands
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Černáková L, Roudbary M, Brás S, Tafaj S, Rodrigues CF. Candida auris: A Quick Review on Identification, Current Treatments, and Challenges. Int J Mol Sci 2021; 22:4470. [PMID: 33922907 PMCID: PMC8123192 DOI: 10.3390/ijms22094470] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/21/2021] [Accepted: 04/21/2021] [Indexed: 02/07/2023] Open
Abstract
Candida auris is a novel and major fungal pathogen that has triggered several outbreaks in the last decade. The few drugs available to treat fungal diseases, the fact that this yeast has a high rate of multidrug resistance and the occurrence of misleading identifications, and the ability of forming biofilms (naturally more resistant to drugs) has made treatments of C. auris infections highly difficult. This review intends to quickly illustrate the main issues in C. auris identification, available treatments and the associated mechanisms of resistance, and the novel and alternative treatment and drugs (natural and synthetic) that have been recently reported.
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Affiliation(s)
- Lucia Černáková
- Department of Microbiology and Virology, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 842 15 Bratislava, Slovakia;
| | - Maryam Roudbary
- Department of Parasitology and Mycology, School of Medicine, Iran University of Medical Sciences, Tehran 1449614535, Iran;
| | - Susana Brás
- Centre of Biological Engineering, LIBRO—‘Laboratório de Investigação em Biofilmes Rosário Oliveira’, University of Minho, 4710-057 Braga, Portugal;
| | - Silva Tafaj
- Microbiology Department, University Hospital “Shefqet Ndroqi”, 1044 Tirana, Albania;
| | - Célia F. Rodrigues
- LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal
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22
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Novel ERG11 and TAC1b mutations associated with azole resistance in Candida auris. Antimicrob Agents Chemother 2021; 65:AAC.02663-20. [PMID: 33619054 PMCID: PMC8092887 DOI: 10.1128/aac.02663-20] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Candida auris is a novel Candida species that has spread in all continents causing nosocomial outbreaks of invasive candidiasis. C. auris has the ability to develop resistance to all antifungal drug classes. Notably, many C. auris isolates are resistant to the azole drug fluconazole, a standard therapy of invasive candidiasis.Azole resistance in C. auris can result from mutations in the azole target gene ERG11 and/or overexpression of the efflux pump Cdr1. TAC1 is a transcription factor controlling CDR1 expression in C. albicans The role of TAC1 homologs in C. auris (TAC1a and TAC1b) remains to be better defined.In this study, we compared sequences of ERG11, TAC1a and TAC1b between a fluconazole-susceptible and five fluconazole-resistant C. auris isolates of clade IV. Among four of the resistant isolates, we identified a similar genotype with concomitant mutations in ERG11 (F444L) and TAC1b (S611P). The simultaneous deletion of tandemly arranged TAC1a/TAC1b resulted in a decrease of minimal inhibitory concentration (MIC) for fluconazole. Introduction of the ERG11 and TAC1b mutations separately and/or combined in the wild-type azole susceptible isolate resulted in a significant increase of azole resistance with a cumulative effect of the two combined mutations. Interestingly, CDR1 expression was not significantly affected by TAC1a/TAC1b deletion or by the presence of the TAC1b S611P mutation, suggesting the existence of Tac1-dependent and Cdr1-independent azole resistance mechanisms.We demonstrated the role of two previously unreported mutations responsible for azole resistance in C. auris, which were a common signature among four azole-resistant isolates of clade IV.
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Carolus H, Pierson S, Muñoz JF, Subotić A, Cruz RB, Cuomo CA, Van Dijck P. Genome-Wide Analysis of Experimentally Evolved Candida auris Reveals Multiple Novel Mechanisms of Multidrug Resistance. mBio 2021; 12:e03333-20. [PMID: 33820824 PMCID: PMC8092288 DOI: 10.1128/mbio.03333-20] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 02/12/2021] [Indexed: 12/12/2022] Open
Abstract
Candida auris is globally recognized as an opportunistic fungal pathogen of high concern, due to its extensive multidrug resistance (MDR). Still, molecular mechanisms of MDR are largely unexplored. This is the first account of genome-wide evolution of MDR in C. auris obtained through serial in vitro exposure to azoles, polyenes, and echinocandins. We show the stepwise accumulation of copy number variations and novel mutations in genes both known and unknown in antifungal drug resistance. Echinocandin resistance was accompanied by a codon deletion in FKS1 hot spot 1 and a substitution in FKS1 "novel" hot spot 3. Mutations in ERG3 and CIS2 further increased the echinocandin MIC. Decreased azole susceptibility was linked to a mutation in transcription factor TAC1b and overexpression of the drug efflux pump Cdr1, a segmental duplication of chromosome 1 containing ERG11, and a whole chromosome 5 duplication, which contains TAC1b The latter was associated with increased expression of ERG11, TAC1b, and CDR2 but not CDR1 The simultaneous emergence of nonsense mutations in ERG3 and ERG11 was shown to decrease amphotericin B susceptibility, accompanied with fluconazole cross-resistance. A mutation in MEC3, a gene mainly known for its role in DNA damage homeostasis, further increased the polyene MIC. Overall, this study shows the alarming potential for and diversity of MDR development in C. auris, even in a clade until now not associated with MDR (clade II), stressing its clinical importance and the urge for future research.IMPORTANCECandida auris is a recently discovered human fungal pathogen and has shown an alarming potential for developing multi- and pan-resistance toward all classes of antifungals most commonly used in the clinic. Currently, C. auris has been globally recognized as a nosocomial pathogen of high concern due to this evolutionary potential. So far, this is the first study in which the stepwise progression of multidrug resistance (MDR) in C. auris is monitored in vitro Multiple novel mutations in known resistance genes and genes previously not or vaguely associated with drug resistance reveal rapid MDR evolution in a C. auris clade II isolate. Additionally, this study shows that in vitro experimental evolution can be a powerful tool to discover new drug resistance mechanisms, although it has its limitations.
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Affiliation(s)
- Hans Carolus
- VIB Center for Microbiology, Leuven, Belgium
- Department of Biology, KU Leuven, Leuven, Belgium
| | | | - José F Muñoz
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Ana Subotić
- VIB Center for Microbiology, Leuven, Belgium
- Department of Biology, KU Leuven, Leuven, Belgium
| | - Rita B Cruz
- Department of Biology, KU Leuven, Leuven, Belgium
| | | | - Patrick Van Dijck
- VIB Center for Microbiology, Leuven, Belgium
- Department of Biology, KU Leuven, Leuven, Belgium
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Experimental Evolution Identifies Adaptive Aneuploidy as a Mechanism of Fluconazole Resistance in Candida auris. Antimicrob Agents Chemother 2020; 65:AAC.01466-20. [PMID: 33077664 DOI: 10.1128/aac.01466-20] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 10/14/2020] [Indexed: 12/22/2022] Open
Abstract
Candida auris is a newly emerging fungal pathogen of humans and has attracted considerable attention from both the clinical and basic research communities. Clinical isolates of C. auris are often resistant to one or more antifungal agents. To explore how antifungal resistance develops, we performed experimental evolution assays using a fluconazole-susceptible isolate of C. auris (BJCA001). After a series of passages through medium containing increasing concentrations of fluconazole, fungal cells acquired resistance. By sequencing and comparing the genomes of the parental fluconazole-susceptible strain and 26 experimentally evolved strains of C. auris, we found that a portion of fluconazole-resistant strains carried one extra copy of chromosome V. In the absence of fluconazole, C. auris cells rapidly became susceptible and lost the extra copy of chromosome V. Genomic and transcriptome sequencing (RNA-Seq) analyses indicate that this chromosome carries a number of drug resistance-related genes, which were transcriptionally upregulated in the resistant, aneuploid strains. Moreover, missense mutations were identified in the genes TAC1B, RRP6, and SFT2 in all experimentally evolved strains. Our findings suggest that the gain of an extra copy of chromosome V is associated with the rapid acquisition of fluconazole resistance and may represent an important evolutionary mechanism of antifungal resistance in C. auris.
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Insights into the Multi-Azole Resistance Profile in Candida haemulonii Species Complex. J Fungi (Basel) 2020; 6:jof6040215. [PMID: 33050545 PMCID: PMC7711680 DOI: 10.3390/jof6040215] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/06/2020] [Accepted: 10/08/2020] [Indexed: 12/25/2022] Open
Abstract
The Candida haemulonii complex (C. duobushaemulonii, C. haemulonii, and C. haemulonii var. vulnera) is composed of emerging, opportunistic human fungal pathogens able to cause invasive infections with high rates of clinical treatment failure. This fungal complex typically demonstrates resistance to first-line antifungals, including fluconazole. In the present work, we have investigated the azole resistance mechanisms expressed in Brazilian clinical isolates forming the C. haemulonii complex. Initially, 12 isolates were subjected to an antifungal susceptibility test, and azole cross-resistance was detected in almost all isolates (91.7%). In order to understand the azole resistance mechanistic basis, the efflux pump activity was assessed by rhodamine-6G. The C. haemulonii complex exhibited a significantly higher rhodamine-6G efflux than the other non-albicans Candida species tested (C. tropicalis, C. krusei, and C. lusitaneae). Notably, the efflux pump inhibitors (Phe-Arg and FK506) reversed the fluconazole and voricolazole resistance phenotypes in the C. haemulonii species complex. Expression analysis indicated that the efflux pump (ChCDR1, ChCDR2, and ChMDR1) and ERG11 genes were not modulated by either fluconazole or voriconazole treatments. Further, ERG11 gene sequencing revealed several mutations, some of which culminated in amino acid polymorphisms, as previously reported in azole-resistant Candida spp. Collectively, these data point out the relevance of drug efflux pumps in mediating azole resistance in the C. haemulonii complex, and mutations in ERG11p may contribute to this resistance profile.
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What do we know about the biology of the emerging fungal pathogen of humans Candida auris? Microbiol Res 2020; 242:126621. [PMID: 33096325 DOI: 10.1016/j.micres.2020.126621] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/25/2020] [Accepted: 10/04/2020] [Indexed: 02/07/2023]
Abstract
Candida auris is a worrisome fungal pathogen of humans which emerged merely about a decade ago. Ever since then the scientific community worked hard to understand clinically relevant traits, such as virulence factors, antifungal resistance mechanisms, and its ability to adhere to human skin and medical devices. Whole-genome sequencing of clinical isolates and epidemiological studies outlining the path of nosocomial outbreaks have been the focus of research into this pathogenic and multidrug-resistant yeast since its first description in 2009. More recently, work was started by several laboratories to explore the biology of C. auris. Here, we review the insights of studies characterizing the mechanisms underpinning antifungal drug resistance, biofilm formation, morphogenetic switching, cell aggregation, virulence, and pathogenicity of C. auris. We conclude that, although some progress has been made, there is still a long journey ahead of us, before we fully understand this novel pathogen. Critically important is the development of molecular tools for C. auris to make this fungus genetically tractable and traceable. This will allow an in-depth molecular dissection of the life cycle of C. auris, of its characteristics while interacting with the human host, and the mechanisms it employs to avoid being killed by antifungals and the immune system.
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Chromatin Structure and Drug Resistance in Candida spp. J Fungi (Basel) 2020; 6:jof6030121. [PMID: 32751495 PMCID: PMC7559719 DOI: 10.3390/jof6030121] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 07/21/2020] [Accepted: 07/25/2020] [Indexed: 12/14/2022] Open
Abstract
Anti-microbial resistance (AMR) is currently one of the most serious threats to global human health and, appropriately, research to tackle AMR garnishes significant investment and extensive attention from the scientific community. However, most of this effort focuses on antibiotics, and research into anti-fungal resistance (AFR) is vastly under-represented in comparison. Given the growing number of vulnerable, immunocompromised individuals, as well as the positive impact global warming has on fungal growth, there is an immediate urgency to tackle fungal disease, and the disturbing rise in AFR. Chromatin structure and gene expression regulation play pivotal roles in the adaptation of fungal species to anti-fungal stress, suggesting a potential therapeutic avenue to tackle AFR. In this review we discuss both the genetic and epigenetic mechanisms by which chromatin structure can dictate AFR mechanisms and will present evidence of how pathogenic yeast, specifically from the Candida genus, modify chromatin structure to promote survival in the presence of anti-fungal drugs. We also discuss the mechanisms by which anti-chromatin therapy, specifically lysine deacetylase inhibitors, influence the acquisition and phenotypic expression of AFR in Candida spp. and their potential as effective adjuvants to mitigate against AFR.
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