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Ksiezopolska E, Schikora-Tamarit MÀ, Carlos Nunez-Rodriguez J, Gabaldón T. Long-term stability of acquired drug resistance and resistance associated mutations in the fungal pathogen Nakaseomyces glabratus ( Candida glabrata). Front Cell Infect Microbiol 2024; 14:1416509. [PMID: 39077431 PMCID: PMC11284152 DOI: 10.3389/fcimb.2024.1416509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 06/25/2024] [Indexed: 07/31/2024] Open
Abstract
The limited number of available antifungal drugs and the increasing number of fungal isolates that show drug or multidrug resistance pose a serious medical threat. Several yeast pathogens, such as Nakaseomyces glabratus (Candida glabrata), show a remarkable ability to develop drug resistance during treatment through the acquisition of genetic mutations. However, how stable this resistance and the underlying mutations are in non-selective conditions remains poorly characterized. The stability of acquired drug resistance has fundamental implications for our understanding of the appearance and spread of drug-resistant outbreaks and for defining efficient strategies to combat them. Here, we used an in vitro evolution approach to assess the stability under optimal growth conditions of resistance phenotypes and resistance-associated mutations that were previously acquired under exposure to antifungals. Our results reveal a remarkable stability of the resistant phenotype and the underlying mutations in a significant number of evolved populations, which conserved their phenotype for at least two months in the absence of drug-selective pressure. We observed a higher stability of anidulafungin resistance over fluconazole resistance, and of resistance-conferring point mutations as compared with aneuploidies. In addition, we detected accumulation of novel mutations in previously altered resistance-associated genes in non-selective conditions, which suggest a possible compensatory role. We conclude that acquired resistance, particularly to anidulafungin, is a long-lasting phenotype, which has important implications for the persistence and propagation of drug-resistant clinical outbreaks.
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Affiliation(s)
- Ewa Ksiezopolska
- Department of Life Sciences, Barcelona Supercomputing Centre (BSC-CNS), Barcelona, Spain
- Department of Mechanisms of Disease, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Miquel Àngel Schikora-Tamarit
- Department of Life Sciences, Barcelona Supercomputing Centre (BSC-CNS), Barcelona, Spain
- Department of Mechanisms of Disease, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Juan Carlos Nunez-Rodriguez
- Department of Life Sciences, Barcelona Supercomputing Centre (BSC-CNS), Barcelona, Spain
- Department of Mechanisms of Disease, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Toni Gabaldón
- Department of Life Sciences, Barcelona Supercomputing Centre (BSC-CNS), Barcelona, Spain
- Department of Mechanisms of Disease, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
- Department of CIBERinfect, Centro Investigación Biomédica En Red de Enfermedades Infecciosas, Barcelona, Spain
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Dunaiski CM, Kock MM, Chan WY, Ismail A, Peters RPH. Molecular epidemiology and antimicrobial resistance of vaginal Candida glabrata isolates in Namibia. Med Mycol 2024; 62:myae009. [PMID: 38308518 DOI: 10.1093/mmy/myae009] [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: 10/17/2023] [Revised: 12/16/2023] [Accepted: 02/01/2024] [Indexed: 02/04/2024] Open
Abstract
Candida glabrata is the most common non-albicans Candida species that causes vulvovaginal candidiasis (VVC). Given the intrinsically low susceptibility of C. glabrata to azole drugs, investigations into C. glabrata prevalence, fungal susceptibility profile, and molecular epidemiology are necessary to optimise the treatment of VVC. This molecular epidemiological study was conducted to determine antifungal drug profile, single nucleotide polymorphisms (SNPs) associated with phenotypic antifungal resistance and epidemic diversity of C. glabrata isolates from women with VVC in Namibia. Candida glabrata isolates were identified using phenotypic and molecular methods. Antifungal susceptibility of strains was determined for fluconazole, itraconazole, amphotericin B, and anidulafungin. Whole genome sequencing was used to determine SNPs in antifungal resistance genes and sequence type (ST) allocation. Among C. glabrata isolates, all (20/20; 100%) exhibited phenotypic resistance to the azole class antifungal drug, (fluconazole), and phenotypic susceptibility to the polyene class (amphotericin B), and the echinocandins (anidulafungin). Non-synonymous SNPs were identified in antifungal resistance genes of all fluconazole-resistant C. glabrata isolates including ERG6 (15%), ERG7 (15%), CgCDR1 (25%), CgPDR1 (60%), SNQ2 (10%), FKS1 (5.0%), FKS2 (5.0%), CgFPS1 (5.0%), and MSH2 (15%). ST15 (n = 8/20, 40%) was predominant. This study provides important insight into phenotypic and genotypic antifungal resistance across C. glabrata isolates from women with VVC in Namibia. In this study, azole resistance is determined by an extensive range of SNPs, while the observed polyene and echinocandin resistance-associated SNPs despite phenotypic susceptibility require further investigation.
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Affiliation(s)
- Cara M Dunaiski
- Namibia University of Sciences and Technology, Department of Health and Applied Sciences, Windhoek 10005, Namibia
- University of Pretoria, Department of Medical Microbiology, Pretoria 0001, South Africa
| | - Marleen M Kock
- University of Pretoria, Department of Medical Microbiology, Pretoria 0001, South Africa
- National Health Laboratory Service, Tshwane, Academic Division, Pretoria 3191, South Africa
| | - Wai Yin Chan
- Sequencing Core Facility, National Institute for Communicable Diseases a Division of the National Health Laboratory Service, Johannesburg 2131, South Africa
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0081, South Africa
- Right to care, Centurion 0157, South Africa
| | - Arshad Ismail
- Sequencing Core Facility, National Institute for Communicable Diseases a Division of the National Health Laboratory Service, Johannesburg 2131, South Africa
- Department of Biochemistry and Microbiology, Faculty of Science, Engineering and Agriculture, University of Venda, Thohoyandou 0950, South Africa
- Institute for Water and Wastewater Technology, Durban University of Technology, Durban 4000, South Africa
| | - Remco P H Peters
- University of Pretoria, Department of Medical Microbiology, Pretoria 0001, South Africa
- University of Cape Town, Division of Medical Microbiology, Cape Town 7701, South Africa
- Foundation for Professional Development, Research Unit, East London 5217, South Africa
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Lefranc M, Accoceberry I, Fitton-Ouhabi V, Biteau N, Noël T. Rapamycin and caspofungin show synergistic antifungal effects in caspofungin-susceptible and caspofungin-resistant Candida strains in vitro. J Antimicrob Chemother 2024; 79:151-156. [PMID: 37991226 DOI: 10.1093/jac/dkad359] [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: 06/30/2023] [Accepted: 11/07/2023] [Indexed: 11/23/2023] Open
Abstract
OBJECTIVES Caspofungin is an echinocandin antifungal agent that inhibits synthesis of glucan required for the fungal cell wall. Resistance is mediated by mutation of Fks1 glucan synthase, among which S645P is the most common resistance-associated polymorphism. Rapamycin is a macrolide that inhibits the mechanistic target of rapamycin (mTOR) protein kinase activity. This study investigated the interaction between rapamycin and caspofungin in inhibiting the growth of WT Candida albicans and Fks1 S645P mutant clinical isolate, and WT Candida lusitaniae and genetically engineered isogenic strain with Fks1 S645P mutation at equivalent position. METHODS Interactions between caspofungin and rapamycin were evaluated using the microdilution chequerboard method in liquid medium. The results were analysed using the Loewe additivity model (FIC index, FICI) and the Bliss independence model (response surface, RS, analysis). RESULTS Synergy between rapamycin and caspofungin was shown for C. albicans and C. lusitaniae strains by RS analysis of the chequerboard tests. Synergy was observed in strains susceptible and resistant to caspofungin. Weak subinhibitory concentrations of rapamycin were sufficient to restore caspofungin susceptibility. CONCLUSIONS We report here, for the first time, synergy between caspofungin and rapamycin in Candida species. Synergy was shown for strains susceptible and resistant to caspofungin. This study highlights the possible implication of the TOR pathway in sensing antifungal-mediated cell wall stress and in modulating the cellular response to echinocandins in Candida yeasts.
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Affiliation(s)
- Maxime Lefranc
- University Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33000 Bordeaux, France
- University Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, CHU Bordeaux, 33000 Bordeaux, France
| | - Isabelle Accoceberry
- University Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33000 Bordeaux, France
- University Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, CHU Bordeaux, 33000 Bordeaux, France
| | - Valérie Fitton-Ouhabi
- University Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33000 Bordeaux, France
| | - Nicolas Biteau
- University Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33000 Bordeaux, France
| | - Thierry Noël
- University Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33000 Bordeaux, France
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Czajka KM, Venkataraman K, Brabant-Kirwan D, Santi SA, Verschoor C, Appanna VD, Singh R, Saunders DP, Tharmalingam S. Molecular Mechanisms Associated with Antifungal Resistance in Pathogenic Candida Species. Cells 2023; 12:2655. [PMID: 37998390 PMCID: PMC10670235 DOI: 10.3390/cells12222655] [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: 10/17/2023] [Revised: 11/14/2023] [Accepted: 11/17/2023] [Indexed: 11/25/2023] Open
Abstract
Candidiasis is a highly pervasive infection posing major health risks, especially for immunocompromised populations. Pathogenic Candida species have evolved intrinsic and acquired resistance to a variety of antifungal medications. The primary goal of this literature review is to summarize the molecular mechanisms associated with antifungal resistance in Candida species. Resistance can be conferred via gain-of-function mutations in target pathway genes or their transcriptional regulators. Therefore, an overview of the known gene mutations is presented for the following antifungals: azoles (fluconazole, voriconazole, posaconazole and itraconazole), echinocandins (caspofungin, anidulafungin and micafungin), polyenes (amphotericin B and nystatin) and 5-fluorocytosine (5-FC). The following mutation hot spots were identified: (1) ergosterol biosynthesis pathway mutations (ERG11 and UPC2), resulting in azole resistance; (2) overexpression of the efflux pumps, promoting azole resistance (transcription factor genes: tac1 and mrr1; transporter genes: CDR1, CDR2, MDR1, PDR16 and SNQ2); (3) cell wall biosynthesis mutations (FKS1, FKS2 and PDR1), conferring resistance to echinocandins; (4) mutations of nucleic acid synthesis/repair genes (FCY1, FCY2 and FUR1), resulting in 5-FC resistance; and (5) biofilm production, promoting general antifungal resistance. This review also provides a summary of standardized inhibitory breakpoints obtained from international guidelines for prominent Candida species. Notably, N. glabrata, P. kudriavzevii and C. auris demonstrate fluconazole resistance.
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Affiliation(s)
- Karolina M. Czajka
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
| | - Krishnan Venkataraman
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada;
| | | | - Stacey A. Santi
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
| | - Chris Verschoor
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada;
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
| | - Vasu D. Appanna
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada;
| | - Ravi Singh
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
| | - Deborah P. Saunders
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
| | - Sujeenthar Tharmalingam
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada;
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
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The Candida glabrata Parent Strain Trap: How Phenotypic Diversity Affects Metabolic Fitness and Host Interactions. Microbiol Spectr 2023; 11:e0372422. [PMID: 36633405 PMCID: PMC9927409 DOI: 10.1128/spectrum.03724-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Reference strains improve reproducibility by standardizing observations and methodology, which has ultimately led to important insights into fungal pathogenesis. However, recent investigations have highlighted significant genotypic and phenotypic heterogeneity across isolates that influence genetic circuitry and virulence within a species. Candida glabrata is the second leading cause of candidiasis, a life-threatening infection, and undergoes extensive karyotype and phenotypic changes in response to stress. Much of the work conducted on this pathogen has focused on two sequenced strains, CBS138 (ATCC 2001) and BG2. Few studies have compared these strains in detail, but key differences include mating type and altered patterns of expression of EPA adhesins. In fact, most C. glabrata isolates and BG2 are MATa, while CBS138 is MATα. However, it is not known if other phenotypic differences between these strains play a role in our understanding of C. glabrata pathogenesis. Thus, we set out to characterize metabolic, cell wall, and host-interaction attributes for CBS138 and BG2. We found that BG2 utilized a broader range of nitrogen sources and had reduced cell wall size and carbohydrate exposure than CBS138, which we hypothesized results in differences in innate immune interactions and virulence. We observed that, although both strains were phagocytosed to a similar extent, BG2 replicated to higher numbers in macrophages and was more virulent during Galleria mellonella infection than CBS138 in a dose-dependent manner. Interestingly, deletion of SNF3, a major nutrient sensor, did not affect virulence in G. mellonella for BG2, but significantly enhanced larval killing in the CBS138 background compared to the parent strain. Understanding these fundamental differences in metabolism and host interactions will allow more robust conclusions to be drawn in future studies of C. glabrata pathogenesis. IMPORTANCE Reference strains provide essential insights into the mechanisms underlying virulence in fungal pathogens. However, recent studies in Candida albicans and other species have revealed significant genotypic and phenotypic diversity within clinical isolates that are challenging paradigms regarding key virulence factors and their regulation. Candida glabrata is the second leading cause of candidiasis, and many studies use BG2 or CBS138 for their investigations. Therefore, we aimed to characterize important virulence-related phenotypes for both strains that might alter conclusions about C. glabrata pathogenesis. Our study provides context for metabolic and cell wall changes and how these may influence host interaction phenotypes. Understanding these differences is necessary to support robust conclusions about how virulence factors may function in these and other very different strain backgrounds.
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Rola A, Potok P, Mos M, Gumienna-Kontecka E, Potocki S. Zn(II) and Cd(II) Complexes of AMT1/MAC1 Homologous Cys/His-Rich Domains: So Similar yet So Different. Inorg Chem 2022; 61:14333-14343. [PMID: 36044397 PMCID: PMC9472267 DOI: 10.1021/acs.inorgchem.2c02080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Infections caused by Candida species are becoming seriously dangerous and difficult to cure due to their sophisticated mechanisms of resistance. The host organism defends itself from the invader, e.g., by increasing the concentration of metal ions. Therefore, there is a need to understand the overall mechanisms of metal homeostasis in Candida species. One of them is associated with AMT1, an important virulence factor derived from Candida glabrata, and another with MAC1, present in Candida albicans. Both of the proteins possess a homologous Cys/His-rich domain. In our studies, we have chosen two model peptides, L680 (Ac-10ACMECVRGHRSSSCKHHE27-NH2, MAC1, Candida albicans) and L681 (Ac-10ACDSCIKSHKAAQCEHNDR28-NH2, AMT1, Candida glabrata), to analyze and compare the properties of their complexes with Zn(II) and Cd(II). We studied the stoichiometry, thermodynamic stability, and spectroscopic parameters of the complexes in a wide pH range. When competing for the metal ion in the equimolar mixture of two ligands and Cd(II)/Zn(II), L680 forms more stable complexes with Cd(II) while L681 forms more stable complexes with Zn(II) in a wide pH range. Interestingly, a Glu residue was responsible for the additional stability of Cd(II)-L680. Despite a number of scientific reports suggesting Cd(II) as an efficient surrogate of Zn(II), we showed significant differences between the Zn(II) and Cd(II) complexes of the studied peptides.
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Affiliation(s)
- Anna Rola
- Faculty of Chemistry, University of Wroclaw, 14 Joliot-Curie Street, 50-383 Wroclaw, Poland
| | - Paulina Potok
- Faculty of Chemistry, University of Wroclaw, 14 Joliot-Curie Street, 50-383 Wroclaw, Poland
| | - Magdalena Mos
- WMG, International Manufacturing Centre, University of Warwick, Coventry CV4 7AL, United Kingdom
| | | | - Sławomir Potocki
- Faculty of Chemistry, University of Wroclaw, 14 Joliot-Curie Street, 50-383 Wroclaw, Poland
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Kamli MR, Sabir JSM, Malik MA, Ahmad A. Human β defensins-1, an antimicrobial peptide, kills Candida glabrata by generating oxidative stress and arresting the cell cycle in G0/G1 phase. Biomed Pharmacother 2022; 154:113569. [PMID: 35988423 DOI: 10.1016/j.biopha.2022.113569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 08/15/2022] [Accepted: 08/15/2022] [Indexed: 11/24/2022] Open
Abstract
Candida glabrata is the most frequently isolated non-albicans Candida species in clinical samples and is known to develop resistance to commonly used antifungal drugs. Human β defensins (hBDs) are antimicrobial peptides of immune systems and are active against a broad range of pathogens including Candida species. Herein, the antifungal effect of hBD-1 and its mechanism of action in C. glabrata was studied. The antifungal susceptibility of hBD-1 against C. glabrata was calculated by broth microdilution assay. To study the mechanism of antifungal action, the impact of hBD-1 on cell cycle, expression of oxidative stress enzymes, and membrane disintegration were assessed. The susceptibility results confirmed that hBD-1 possessed the minimum inhibitory concentration of 3.12 µg/mL and prevented the growth and caused yeast cell death to various extents. The peptide at subinhibitory and inhibitory concentrations blocked the cell cycle in C. glabrata in G0/G1 phase and disturbed the activity of primary and secondary antioxidant enzymes. Furthermore, at higher concentrations disruption of membrane integrity was observed. Altogether, hBD-1 showed candidicidal activity against C. glabrata and was able to induce oxidative stress and arrested cell cycle in C. auris and therefore has a potential to be developed as an antifungal drug against C. glabrata.
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Affiliation(s)
- Majid Rasool Kamli
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia; Center of excellence in Bionanoscience Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
| | - Jamal S M Sabir
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia; Center of excellence in Bionanoscience Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Maqsood Ahmad Malik
- Department of Chemistry, Faculty of Sciences, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia
| | - Aijaz Ahmad
- Center of excellence in Bionanoscience Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia; Department of Clinical Microbiology and Infectious Diseases, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Division of Infection Control, Charlotte Maxeke Johannesburg Academic Hospital, National Health Laboratory Service, Johannesburg, South Africa.
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Dunaiski CM, Kock MM, Jung H, Peters RPH. Importance of Candida infection and fluconazole resistance in women with vaginal discharge syndrome in Namibia. Antimicrob Resist Infect Control 2022; 11:104. [PMID: 35971143 PMCID: PMC9377096 DOI: 10.1186/s13756-022-01143-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 07/27/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Vaginal discharge syndrome (VDS) is a common condition. Clinical management targets sexually transmitted infections (STIs) and bacterial vaginosis (BV); there is limited focus on Candida infection as cause of VDS. Lack of Candida treatment coverage and, if present, antifungal resistance may result in VDS treatment failure. This study aimed to determine the prevalence of Candida infection, antifungal resistance, and coinfections in Namibian women with VDS. METHODS A cross-sectional study was performed using 253 vaginal swabs from women with VDS in Namibia. Demographic data was collected, and phenotypic and molecular detection of Candida species was performed followed by fluconazole susceptibility testing of Candida isolates. BV was diagnosed using Nugent score microscopy; molecular detection of Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis was performed. RESULTS Candida species was detected in 110/253 women (43%). Ninety women (36%) had Candida albicans and 24 (9.5%) had non-albicans Candida species. The non-albicans species detected were 19 (17%) Candida glabrata, 4.0 (3.5%) Candida krusei, and 1.0 (0.9%) Candida parapsilosis. Candida albicans were more frequently isolated in younger (p = 0.004) and pregnant women (p = 0.04) compared to non-albicans Candida species. Almost all (98%) Candida albicans isolates were susceptible to fluconazole while all non-albicans Candida species were fluconazole resistant. STIs were diagnosed in 92 women (36%): 30 (12%) with C. trachomatis, 11 (4.3%) N. gonorrhoeae, and 70 (28%) T. vaginalis; 98 (39%) women had BV. Candida infection alone was diagnosed in 30 women (12%), combined with STIs in 42 women (17%) and was concurrent with BV in 38 women (15%). Candida infection was more often detected in swabs from women without C. trachomatis detected (6.4% vs. 16%; OR 0.30; 95% CI 0.10-0.77, p = 0.006). CONCLUSIONS The high prevalence of Candida infection, especially those due to non-albicans Candida species that are resistant to fluconazole, is a great concern in our setting and may lead to poor treatment outcomes. Access to microbiological testing for Candida species in the context of syndromic management is warranted.
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Affiliation(s)
- Cara M Dunaiski
- Department of Health and Applied Sciences, Namibia University of Sciences and Technology, Windhoek, Namibia
- Department of Medical Microbiology, University of Pretoria, Prinshof Campus, Pathology Building, Room 3-11, Pretoria, South Africa
| | - Marleen M Kock
- Department of Medical Microbiology, University of Pretoria, Prinshof Campus, Pathology Building, Room 3-11, Pretoria, South Africa
- Tshwane Academic Division, National Health Laboratory Service, Pretoria, South Africa
| | - Hyunsul Jung
- Department of Medical Microbiology, University of Pretoria, Prinshof Campus, Pathology Building, Room 3-11, Pretoria, South Africa
| | - Remco P H Peters
- Department of Medical Microbiology, University of Pretoria, Prinshof Campus, Pathology Building, Room 3-11, Pretoria, South Africa.
- Division of Medical Microbiology, University of Cape Town, Cape Town, South Africa.
- Research Unit, Foundation for Professional Development, East London, South Africa.
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Krishna Chaaithanya I, Mujumdar Y, Anwesh M, Aranha C. Novel genotypes of vaginal Candida glabrata isolates from premenopausal asymptomatic women with vulvovaginitis. Eur J Obstet Gynecol Reprod Biol 2022; 276:249-250. [PMID: 35909039 DOI: 10.1016/j.ejogrb.2022.07.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 07/15/2022] [Indexed: 11/04/2022]
Affiliation(s)
- Itta Krishna Chaaithanya
- Department of Molecular Immunology & Microbiology, ICMR- National Institute for Research in Reproductive and Child Health (ICMR-NIRRCH), Mumbai, Maharashtra, India.
| | - Yogini Mujumdar
- Department of Molecular Immunology & Microbiology, ICMR- National Institute for Research in Reproductive and Child Health (ICMR-NIRRCH), Mumbai, Maharashtra, India
| | - Maile Anwesh
- Model Rural Health Research Unit (ICMR-NIRRCH), Department of Health Research, Dahanu, Maharashtra, India
| | - Clara Aranha
- Department of Molecular Immunology & Microbiology, ICMR- National Institute for Research in Reproductive and Child Health (ICMR-NIRRCH), Mumbai, Maharashtra, India.
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Ploidy Variation and Spontaneous Haploid-Diploid Switching of Candida glabrata Clinical Isolates. mSphere 2022; 7:e0026022. [PMID: 35727043 PMCID: PMC9429935 DOI: 10.1128/msphere.00260-22] [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
The human fungal pathogen Candida glabrata is phylogenetically closely related to Saccharomyces cerevisiae, a model eukaryotic organism. Unlike S. cerevisiae, which has both haploid and diploid forms and a complete sexual cycle, C. glabrata has long been considered a haploid and asexual species. In this study, we analyzed the ploidy states of 500 clinical isolates of C. glabrata from four Chinese hospitals and found that approximately 4% of the isolates were in or able to spontaneously switch to an aneuploid (genomic DNA, 1N-2N), diploid (2N), or hyperdiploid (>2N) form under in vivo or in vitro conditions. Stable diploid cells were identified in 3% of the isolates (15/500). Of particular interest, one clinical strain existed only in the diploid form. Multilocus sequence typing (MLST) assays revealed two major genetic clusters (A and B) of C. glabrata isolates. Most of the isolates (70%) from China belonged to the A cluster, whereas most of the isolates from other countries (such as Iran, Japan, United States, and European countries) belonged to the B cluster. Further investigation indicated that C. glabrata cells of different ploidy forms differed in a number of respects, including morphologies, antifungal susceptibility, virulence, and global gene expression profiles. Additionally, C. glabrata could undergo spontaneous switching between the diploid and haploid forms under both in vitro and in vivo conditions. Given the absence of an apparent sexual phase, one would expect that the ploidy shifts could function as an alternative strategy that promotes genetic diversity and benefits the ability of the fungus to rapidly adapt to the changing environment. IMPORTANCE The human fungal pathogen Candida glabrata has long been thought to be a haploid organism. Here, we report the population structure and ploidy states of 500 clinical isolates of C. glabrata from China. To our surprise, we found that the ploidy of a subset of clinical isolates varied dramatically. Some isolates were in or able to switch to an aneuploid, diploid, or hyperdiploid form. C. glabrata cells with different ploidy differed in a number of biological respects, including morphology, antifungal susceptibility, virulence, and global gene expression profile. Given the absence of an apparent sexual phase in this fungus, we propose that ploidy switching could be a strategy for rapid adaptation to environmental changes and could function as an alternative to sexual reproduction.
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Evolutionary Significance of Fungal Hypermutators: Lessons Learned from Clinical Strains and Implications for Fungal Plant Pathogens. mSphere 2022; 7:e0008722. [PMID: 35638358 PMCID: PMC9241500 DOI: 10.1128/msphere.00087-22] [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
Rapid evolution of fungal pathogens poses a serious threat to medicine and agriculture. The mutation rate determines the pace of evolution of a fungal pathogen. Hypermutator fungal strains have an elevated mutation rate owing to certain defects such as those in the DNA mismatch repair system. Studies in Saccharomyces cerevisiae show that hypermutators expedite evolution by generating beneficial alleles at a faster pace than the wild-type strains. However, an accumulation of deleterious alleles in a hypermutator may reduce its fitness. The balance between fitness cost and mutation benefit determines the prevalence of hypermutators in a population. This balance is affected by a complex interaction of ploidy, mode of reproduction, population size, and recent population history. Studies in human fungal pathogens like Aspergillus fumigatus, Candida albicans, Candida glabrata, Cryptococcus deuterogattii, and Cryptococcus neoformans have highlighted the importance of hypermutators in host adaptation and development of antifungal resistance. However, a critical examination of hypermutator biology, experimental evolution studies, and epidemiological studies suggests that hypermutators may impact evolutionary investigations. This review aims to integrate the knowledge about biology, experimental evolution, and dynamics of fungal hypermutators to critically examine the evolutionary role of hypermutators in fungal pathogen populations and project implications of hypermutators in the evolution of fungal plant pathogen populations. Understanding the factors determining the emergence and evolution of fungal hypermutators can open a novel avenue of managing rapidly evolving fungal pathogens in medicine and agriculture.
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Castanheira M, Deshpande LM, Davis AP, Carvalhaes CG, Pfaller MA. Azole Resistance in Candida glabrata Clinical Isolates from Global Surveillance is Associated with Efflux Overexpression. J Glob Antimicrob Resist 2022; 29:371-377. [DOI: 10.1016/j.jgar.2022.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 05/05/2022] [Accepted: 05/06/2022] [Indexed: 11/28/2022] Open
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Murphy SE, Bicanic T. Drug Resistance and Novel Therapeutic Approaches in Invasive Candidiasis. Front Cell Infect Microbiol 2022; 11:759408. [PMID: 34970504 PMCID: PMC8713075 DOI: 10.3389/fcimb.2021.759408] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 11/08/2021] [Indexed: 12/12/2022] Open
Abstract
Candida species are the leading cause of invasive fungal infections worldwide and are associated with acute mortality rates of ~50%. Mortality rates are further augmented in the context of host immunosuppression and infection with drug-resistant Candida species. In this review, we outline antifungal drugs already in clinical use for invasive candidiasis and candidaemia, their targets and mechanisms of resistance in clinically relevant Candida species, encompassing not only classical resistance, but also heteroresistance and tolerance. We describe novel antifungal agents and targets in pre-clinical and clinical development, including their spectrum of activity, antifungal target, clinical trial data and potential in treatment of drug-resistant Candida. Lastly, we discuss the use of combination therapy between conventional and repurposed agents as a potential strategy to combat the threat of emerging resistance in Candida.
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Affiliation(s)
- Sarah E Murphy
- Institute of Infection & Immunity, St George's University of London, London, United Kingdom
| | - Tihana Bicanic
- Institute of Infection & Immunity, St George's University of London, London, United Kingdom.,Clinical Academic Group in Infection and Immunity, St. George's University Hospital National Health Service (NHS) Foundation Trust, London, United Kingdom
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Ksiezopolska E, Schikora-Tamarit MÀ, Beyer R, Nunez-Rodriguez JC, Schüller C, Gabaldón T. Narrow mutational signatures drive acquisition of multidrug resistance in the fungal pathogen Candida glabrata. Curr Biol 2021; 31:5314-5326.e10. [PMID: 34699784 PMCID: PMC8660101 DOI: 10.1016/j.cub.2021.09.084] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 07/20/2021] [Accepted: 09/29/2021] [Indexed: 01/25/2023]
Abstract
Fungal infections are a growing medical concern, in part due to increased resistance to one or multiple antifungal drugs. However, the evolutionary processes underpinning the acquisition of antifungal drug resistance are poorly understood. Here, we used experimental microevolution to study the adaptation of the yeast pathogen Candida glabrata to fluconazole and anidulafungin, two widely used antifungal drugs with different modes of action. Our results show widespread ability of rapid adaptation to one or both drugs. Resistance, including multidrug resistance, is often acquired at moderate fitness costs and mediated by mutations in a limited set of genes that are recurrently and specifically mutated in strains adapted to each of the drugs. Importantly, we uncover a dual role of ERG3 mutations in resistance to anidulafungin and cross-resistance to fluconazole in a subset of anidulafungin-adapted strains. Our results shed light on the mutational paths leading to resistance and cross-resistance to antifungal drugs.
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Affiliation(s)
- Ewa Ksiezopolska
- Barcelona Supercomputing Centre (BSC-CNS), Life Sciences Department, Jordi Girona 29, 08034 Barcelona, Spain; Institute for Research in Biomedicine (IRB Barcelona), Mechanisms of Disease Program, The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Miquel Àngel Schikora-Tamarit
- Barcelona Supercomputing Centre (BSC-CNS), Life Sciences Department, Jordi Girona 29, 08034 Barcelona, Spain; Institute for Research in Biomedicine (IRB Barcelona), Mechanisms of Disease Program, The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Reinhard Beyer
- Institute of Microbial Genetics and Core Facility Bioactive Substances: Screening and Analysis, University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad Lorenz Strasse 24, 3430 Tulln an der Donau, Austria
| | - Juan Carlos Nunez-Rodriguez
- Barcelona Supercomputing Centre (BSC-CNS), Life Sciences Department, Jordi Girona 29, 08034 Barcelona, Spain; Institute for Research in Biomedicine (IRB Barcelona), Mechanisms of Disease Program, The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Christoph Schüller
- Institute of Microbial Genetics and Core Facility Bioactive Substances: Screening and Analysis, University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad Lorenz Strasse 24, 3430 Tulln an der Donau, Austria
| | - Toni Gabaldón
- Barcelona Supercomputing Centre (BSC-CNS), Life Sciences Department, Jordi Girona 29, 08034 Barcelona, Spain; Institute for Research in Biomedicine (IRB Barcelona), Mechanisms of Disease Program, The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain; Catalan Institution for Research and Advanced Studies (ICREA), Passeig Lluis Companys 23, 08010 Barcelona, Spain.
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Frías-De-León MG, Hernández-Castro R, Conde-Cuevas E, García-Coronel IH, Vázquez-Aceituno VA, Soriano-Ursúa MA, Farfán-García ED, Ocharán-Hernández E, Rodríguez-Cerdeira C, Arenas R, Robledo-Cayetano M, Ramírez-Lozada T, Meza-Meneses P, Pinto-Almazán R, Martínez-Herrera E. Candida glabrata Antifungal Resistance and Virulence Factors, a Perfect Pathogenic Combination. Pharmaceutics 2021; 13:pharmaceutics13101529. [PMID: 34683822 PMCID: PMC8538829 DOI: 10.3390/pharmaceutics13101529] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/03/2021] [Accepted: 09/14/2021] [Indexed: 02/07/2023] Open
Abstract
In recent years, a progressive increase in the incidence of invasive fungal infections (IFIs) caused by Candida glabrata has been observed. The objective of this literature review was to study the epidemiology, drug resistance, and virulence factors associated with the C. glabrata complex. For this purpose, a systematic review (January 2001-February 2021) was conducted on the PubMed, Scielo, and Cochrane search engines with the following terms: "C. glabrata complex (C. glabrata sensu stricto, C. nivariensis, C. bracarensis)" associated with "pathogenicity" or "epidemiology" or "antibiotics resistance" or "virulence factors" with language restrictions of English and Spanish. One hundred and ninety-nine articles were found during the search. Various mechanisms of drug resistance to azoles, polyenes, and echinocandins were found for the C. glabrata complex, depending on the geographical region. Among the mechanisms found are the overexpression of drug transporters, gene mutations that alter thermotolerance, the generation of hypervirulence due to increased adhesion factors, and modifications in vital enzymes that produce cell wall proteins that prevent the activity of drugs designed for its inhibition. In addition, it was observed that the C. glabrata complex has virulence factors such as the production of proteases, phospholipases, and hemolysins, and the formation of biofilms that allows the complex to evade the host immune response and generate fungal resistance. Because of this, the C. glabrata complex possesses a perfect pathogenetic combination for the invasion of the immunocompromised host.
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Affiliation(s)
- María Guadalupe Frías-De-León
- Unidad de Investigación, Hospital Regional de Alta Especialidad de Ixtapaluca, Ixtapaluca 56530, Mexico; (M.G.F.-D.-L.); (M.R.-C.)
| | - Rigoberto Hernández-Castro
- Departamento de Ecología de Agentes Patógenos, Hospital General “Dr. Manuel Gea González”, Ciudad de México 14080, Mexico; (R.H.-C.); (V.A.V.-A.)
| | - Esther Conde-Cuevas
- Maestría en Ciencias de la Salud, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Ciudad de México 11340, Mexico; (E.C.-C.); (I.H.G.-C.); (P.M.-M.)
| | - Itzel H. García-Coronel
- Maestría en Ciencias de la Salud, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Ciudad de México 11340, Mexico; (E.C.-C.); (I.H.G.-C.); (P.M.-M.)
| | - Víctor Alfonso Vázquez-Aceituno
- Departamento de Ecología de Agentes Patógenos, Hospital General “Dr. Manuel Gea González”, Ciudad de México 14080, Mexico; (R.H.-C.); (V.A.V.-A.)
| | - Marvin A. Soriano-Ursúa
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Ciudad de México 11340, Mexico; (M.A.S.-U.); (E.D.F.-G.); (E.O.-H.)
| | - Eunice D. Farfán-García
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Ciudad de México 11340, Mexico; (M.A.S.-U.); (E.D.F.-G.); (E.O.-H.)
| | - Esther Ocharán-Hernández
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Ciudad de México 11340, Mexico; (M.A.S.-U.); (E.D.F.-G.); (E.O.-H.)
| | - Carmen Rodríguez-Cerdeira
- Efficiency, Quality, and Costs in Health Services Research Group (EFISALUD), Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, 36213 Vigo, Spain; (C.R.-C.); (R.A.)
- Dermatology Department, Hospital Vithas Ntra. Sra. de Fátima and University of Vigo, 36206 Vigo, Spain
- Campus Universitario, University of Vigo, 36310 Vigo, Spain
| | - Roberto Arenas
- Efficiency, Quality, and Costs in Health Services Research Group (EFISALUD), Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, 36213 Vigo, Spain; (C.R.-C.); (R.A.)
- Sección de Micología, Hospital General “Dr. Manuel Gea González”, Tlalpan, Ciudad de México 14080, Mexico
| | - Maura Robledo-Cayetano
- Unidad de Investigación, Hospital Regional de Alta Especialidad de Ixtapaluca, Ixtapaluca 56530, Mexico; (M.G.F.-D.-L.); (M.R.-C.)
| | - Tito Ramírez-Lozada
- Servicio de Ginecología y Obstetricia, Hospital Regional de Alta Especialidad de Ixtapaluca, Ixtapaluca 56530, Mexico;
| | - Patricia Meza-Meneses
- Maestría en Ciencias de la Salud, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Ciudad de México 11340, Mexico; (E.C.-C.); (I.H.G.-C.); (P.M.-M.)
- Servicio de Infectología, Hospital Regional de Alta Especialidad de Ixtapaluca, Ixtapaluca 56530, Mexico
| | - Rodolfo Pinto-Almazán
- Unidad de Investigación, Hospital Regional de Alta Especialidad de Ixtapaluca, Ixtapaluca 56530, Mexico; (M.G.F.-D.-L.); (M.R.-C.)
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Ciudad de México 11340, Mexico; (M.A.S.-U.); (E.D.F.-G.); (E.O.-H.)
- Correspondence: (R.P.-A.); (E.M.-H.); Tel.: +52-555-972-9800 (R.P.-A. or E.M.-H.)
| | - Erick Martínez-Herrera
- Unidad de Investigación, Hospital Regional de Alta Especialidad de Ixtapaluca, Ixtapaluca 56530, Mexico; (M.G.F.-D.-L.); (M.R.-C.)
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Ciudad de México 11340, Mexico; (M.A.S.-U.); (E.D.F.-G.); (E.O.-H.)
- Efficiency, Quality, and Costs in Health Services Research Group (EFISALUD), Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, 36213 Vigo, Spain; (C.R.-C.); (R.A.)
- Correspondence: (R.P.-A.); (E.M.-H.); Tel.: +52-555-972-9800 (R.P.-A. or E.M.-H.)
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Badaró MM, Bueno FL, Makrakis LR, Araújo CB, Oliveira VDC, Macedo AP, Paranhos HDFO, Watanabe E, Silva-Lovato CH. Action of disinfectant solutions on adaptive capacity and virulence factors of the Candida spp. biofilms formed on acrylic resin. J Appl Oral Sci 2021; 29:e20210024. [PMID: 34495107 PMCID: PMC8425898 DOI: 10.1590/1678-7757-2021-0024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 04/19/2021] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Understanding the behavior of Candida spp. when exposed to denture disinfectants is essential to optimize their effectiveness. Changes in the virulence factors may cause increased resistance of Candida spp. to disinfectant agents. OBJECTIVE To evaluate the microbial load, cellular metabolism, hydrolytic enzyme production, hyphae formation, live cell and biofilm quantification of Candida albicans, Candida tropicalis and Candida glabrata after exposure to disinfectant solutions. METHODOLOGY Simple biofilms were grown on heat-polymerized acrylic resin specimens, and divided into groups according to solutions/strains: distilled water (control); 0.25% sodium hypochlorite (NaOCl 0.25% ); 10% Ricinus communis (RC 10%); and 0.5% Chloramine T (CT 0.5%). The virulence factors were evaluated using the CFU count (microbial load), XTT method (cell metabolism), epifluorescence microscopy (biofilm removal and live or dead cells adhered), protease and phospholipase production and hyphae formation. Data were analyzed (α=0.05) by one-way ANOVA/ Tukey post hoc test, Kruskal-Wallis test and Wilcoxon test. RESULTS NaOCl 0.25% was the most effective solution. CT 0.5% reduced the number of CFUs more than RC 10% and the control. RC 10% was effective only against C. glabrata. RC 10% and CT 0.5% decreased the cellular metabolism of C. albicans and C. glabrata. Enzyme production was not affected. Hyphal growth in the RC 10% and CT 0.5% groups was similar to that of the control. CT 0.5% was better than RC 10% against C. albicans and C. tropicalis when measuring the total amount of biofilm and number of living cells. For C. glabrata, CT 0.5% was equal to RC 10% in the maintenance of living cells; RC 10% was superior for biofilm removal. CONCLUSIONS The CT 0.5% achieved better results than those of Ricinus communis at 10%, favoring the creation of specific products for dentures. Adjustments in the formulations of RC 10% are necessary due to efficacy against C. glabrata. The NaOCl 0.25% is the most effective and could be suitable for use as a positive control.
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Affiliation(s)
- Mauricio Malheiros Badaró
- Universidade Federal de Santa Catarina (UFSC), Departamento de Odontologia, Florianópolis, SC, Brasil
| | - Frank Lucarini Bueno
- Universidade José do Rosário Vellano (UNIFENAS), Departamento de Odontologia, Alfenas, MG, Brasil
| | - Lais Ranieri Makrakis
- Universidade de São Paulo (USP), Faculdade de Odontologia de Ribeirão Preto, Departamento de Materiais Dentários e Prótese, Ribeirão Preto, SP, Brasil
| | - Camila Borba Araújo
- Universidade de São Paulo (USP), Faculdade de Odontologia de Ribeirão Preto, Departamento de Materiais Dentários e Prótese, Ribeirão Preto, SP, Brasil
| | - Viviane de Cássia Oliveira
- Universidade de São Paulo (USP), Faculdade de Odontologia de Ribeirão Preto, Departamento de Materiais Dentários e Prótese, Ribeirão Preto, SP, Brasil
| | - Ana Paula Macedo
- Universidade de São Paulo (USP), Faculdade de Odontologia de Ribeirão Preto, Departamento de Materiais Dentários e Prótese, Ribeirão Preto, SP, Brasil
| | - Helena de Freitas Oliveira Paranhos
- Universidade de São Paulo (USP), Faculdade de Odontologia de Ribeirão Preto, Departamento de Materiais Dentários e Prótese, Ribeirão Preto, SP, Brasil
| | - Evandro Watanabe
- Universidade de São Paulo (USP), Faculdade de Odontologia de Ribeirão Preto, Departamento de Odontologia Restauradora, Ribeirão Preto, SP, Brasil
| | - Cláudia Helena Silva-Lovato
- Universidade de São Paulo (USP), Faculdade de Odontologia de Ribeirão Preto, Departamento de Materiais Dentários e Prótese, Ribeirão Preto, SP, Brasil
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Garcia-Rubio R, Jimenez-Ortigosa C, DeGregorio L, Quinteros C, Shor E, Perlin DS. Multifactorial Role of Mitochondria in Echinocandin Tolerance Revealed by Transcriptome Analysis of Drug-Tolerant Cells. mBio 2021; 12:e0195921. [PMID: 34372698 PMCID: PMC8406274 DOI: 10.1128/mbio.01959-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Fungal infections cause significant mortality and morbidity worldwide, and the limited existing antifungal reservoir is further weakened by the emergence of strains resistant to echinocandins, a first line of antifungal therapy. Candida glabrata is an opportunistic fungal pathogen that rapidly develops mutations in the echinocandin drug target β-1,3-glucan synthase (GS), which are associated with drug resistance and clinical failure. Although echinocandins are considered fungicidal in Candida sp., a subset of C. glabrata cells survive echinocandin exposure, forming a drug-tolerant cell reservoir, from which resistant mutations are thought to emerge. Despite their importance, the physiology of rare drug-tolerant cells is poorly understood. We used fluorescence-activated cell sorting to enrich for echinocandin-tolerant cells, followed by modified single-cell RNA sequencing to examine their transcriptional landscape. This analysis identified a transcriptional signature distinct from the stereotypical yeast environmental stress response and characterized by upregulation of pathways involved in chromosome structure and DNA topology and downregulation of oxidative stress responses, of which the latter was observed despite increased levels of reactive oxygen species. Further analyses implicated mitochondria in echinocandin tolerance, wherein inhibitors of mitochondrial complexes I and IV reduced echinocandin-mediated cell killing, but mutants lacking various mitochondrial components all showed an echinocandin hypotolerant phenotype. Finally, GS enzyme complexes purified from mitochondrial mutants exhibited normal in vitro inhibition kinetics, indicating that mitochondrial defects influence cell survival downstream of the drug-target interaction. Together, these results provide new insights into the C. glabrata response to echinocandins and reveal a multifactorial role of mitochondria in echinocandin tolerance. IMPORTANCE Echinocandin drugs are a first-line therapy to treat invasive candidiasis, which is a major source of morbidity and mortality worldwide. The opportunistic fungal pathogen Candida glabrata is a prominent bloodstream fungal pathogen, and it is notable for rapidly developing echinocandin-resistant strains associated with clinical failure. Echinocandin resistance is thought to emerge within a small echinocandin-tolerant subset of C. glabrata cells that are not killed by drug exposure, but mechanisms underlying echinocandin tolerance are still unknown. Here, we describe the unique transcriptional signature of echinocandin-tolerant cells and the results of follow-up analyses, which reveal a multifactorial role of mitochondria in C. glabrata echinocandin tolerance. In particular, although chemical inhibition of respiratory chain enzymes increased echinocandin tolerance, deletion of multiple mitochondrial components made C. glabrata cells hypotolerant to echinocandins. Together, these results provide new insights into the C. glabrata response to echinocandins and reveal the involvement of mitochondria in echinocandin tolerance.
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Affiliation(s)
- Rocio Garcia-Rubio
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
| | | | - Lucius DeGregorio
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
| | - Christopher Quinteros
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
| | - Erika Shor
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
- Department of Medical Sciences, Hackensack Meridian Health School of Medicine, Nutley, New Jersey, USA
| | - David S. Perlin
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
- Department of Medical Sciences, Hackensack Meridian Health School of Medicine, Nutley, New Jersey, USA
- Lombardi Comprehensive Cancer Center, Department of Microbiology and Immunology, Georgetown University, Washington, DC, USA
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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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19
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Chew KL, Octavia S, Jureen R, Lin RTP, Teo JWP. Targeted amplification and MinION nanopore sequencing of key azole and echinocandin resistance determinants of clinically relevant Candida spp. from blood culture bottles. Lett Appl Microbiol 2021; 73:286-293. [PMID: 34060660 DOI: 10.1111/lam.13516] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/29/2021] [Accepted: 05/21/2021] [Indexed: 12/19/2022]
Abstract
The objective of the study was to evaluate the use of targeted multiplex Nanopore MinION amplicon re-sequencing of key Candida spp. from blood culture bottles to identify azole and echinocandin resistance associated SNPs. Targeted PCR amplification of azole (ERG11 and ERG3) and echinocandin (FKS) resistance-associated loci was performed on positive blood culture media. Sequencing was performed using MinION nanopore device with R9.4.1 Flow Cells. Twenty-eight spiked blood cultures (ATCC strains and clinical isolates) and 12 prospectively collected positive blood cultures with candidaemia were included. Isolate species included Candida albicans, Candida glabrata, Candida krusei, Candida parapsilosis, Candida tropicalis and Candida auris. SNPs that were identified on ERG and FKS genes using Snippy tool and CLC Genomic Workbench were correlated with phenotypic testing by broth microdilution (YeastOne™ Sensititre). Illumina whole-genome-sequencing and Sanger-sequencing were also performed as confirmatory testing of the mutations identified from nanopore sequencing data. There was a perfect agreement of the resistance-associated mutations detected by MinION-nanopore-sequencing compared to phenotypic testing for acquired resistance (16 with azole resistance; 3 with echinocandin resistance), and perfect concordance of the nanopore sequence mutations to Illumina and Sanger data. Mutations with no known association with phenotypic drug resistance and novel mutations were also detected.
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Affiliation(s)
- K L Chew
- Department of Laboratory Medicine, National University Hospital, Singapore
| | - S Octavia
- National Public Health Laboratory, National Centre for Infectious Diseases, Singapore
| | - R Jureen
- Department of Laboratory Medicine, National University Hospital, Singapore
| | - R T P Lin
- Department of Laboratory Medicine, National University Hospital, Singapore.,National Public Health Laboratory, National Centre for Infectious Diseases, Singapore
| | - J W P Teo
- Department of Laboratory Medicine, National University Hospital, Singapore
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20
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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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21
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Abstract
Cell cycle checkpoints and DNA repair pathways contribute to maintaining genome integrity and are thought to be evolutionarily ancient and broadly conserved. For example, in the yeast Saccharomyces cerevisiae and humans, DNA damage induces activation of a checkpoint effector kinase, Rad53p (human homolog Chk2), to promote cell cycle arrest and transcription of DNA repair genes. Cell cycle checkpoints and DNA repair pathways contribute to maintaining genome integrity and are thought to be evolutionarily ancient and broadly conserved. For example, in the yeast Saccharomyces cerevisiae and humans, DNA damage induces activation of a checkpoint effector kinase, Rad53p (human homolog Chk2), to promote cell cycle arrest and transcription of DNA repair genes. However, recent studies have revealed variation in the DNA damage response networks of some fungi. For example, Shor et al. (mBio 11:e03044-20, 2020, https://doi.org/10.1128/mBio.03044-20) demonstrate that in comparison to S. cerevisiae, the fungal pathogen Candida glabrata has reduced activation of Rad53p in response to DNA damage. Consequently, some downstream targets that contribute to S. cerevisiae genome maintenance, such as DNA polymerases, are transcriptionally downregulated in C. glabrata. Downregulation of genome maintenance genes likely contributes to higher rates of mitotic failure and cell death in C. glabrata. This and other recent findings highlight evolutionary diversity in eukaryotic DNA damage responses.
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22
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Shor E, Perlin DS. DNA damage response of major fungal pathogen Candida glabrata offers clues to explain its genetic diversity. Curr Genet 2021; 67:439-445. [PMID: 33620543 DOI: 10.1007/s00294-021-01162-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 01/29/2021] [Accepted: 02/02/2021] [Indexed: 01/02/2023]
Abstract
How cells respond to DNA damage is key to maintaining genome integrity or facilitating genetic change. In fungi, DNA damage responses have been extensively characterized in the model budding yeast Saccharomyces cerevisiae, which is generally not pathogenic. However, it is not clear how closely these responses resemble those in fungal pathogens, in which genetic change plays an important role in the evolutionary arms race between pathogen and host and the evolution of antifungal drug resistance. A close relative of S. cerevisiae, Candida glabrata, is an opportunistic pathogen that displays high variability in chromosome structure among clinical isolates and rapidly evolves antifungal drug resistance. The mechanisms facilitating such genomic flexibility and evolvability in this organism are unknown. Recently we characterized the DNA damage response of C. glabrata and identified several features that distinguish it from the well characterized DNA damage response of S. cerevisiae. First, we discovered that, in contrast to the established paradigm, C. glabrata effector kinase Rad53 is not hyperphosphorylated upon DNA damage. We also uncovered evidence of an attenuated DNA damage checkpoint response, wherein in the presence of DNA damage C. glabrata cells did not accumulate in S-phase and proceeded with cell division, leading to aberrant mitoses and cell death. Finally, we identified evidence of transcriptional rewiring of the DNA damage response of C. glabrata relative to S. cerevisiae, including an upregulation of genes involved in mating and meiosis-processes that have not been reported in C. glabrata. Together, these results open new possibilities and raise tantalizing questions of how this major fungal pathogen facilitates genetic change.
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Affiliation(s)
- Erika Shor
- Center for Discovery and Innovation, Nutley, NJ, 07110, USA. .,Hackensack Meridian School of Medicine, Nutley, NJ, 07110, USA.
| | - David S Perlin
- Center for Discovery and Innovation, Nutley, NJ, 07110, USA.,Hackensack Meridian School of Medicine, Nutley, NJ, 07110, USA.,Georgetown University Lombardi Comprehensive Cancer Center, Washington, DC, 20057, USA
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23
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Inthanachai T, Thammahong A, Edwards SW, Virakul S, Kiatsurayanon C, Chiewchengchol D. The Inhibitory Effect of Human Beta-defensin-3 on Candida Glabrata Isolated from Patients with Candidiasis. Immunol Invest 2021; 50:80-91. [PMID: 32316784 DOI: 10.1080/08820139.2020.1755307] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Candida glabrata is a common non-albicans Candida species found in patients with candidiasis and it sometimes develops antifungal resistance. Human beta-defensin-3 (hBD-3) is an antimicrobial peptide of immune system active against various types of microbes including Candida spp. This study investigated antifungal activity of hBD-3 and its synergistic effect with a first-line antifungal agent on C. glabrata clinical isolates. Candida spp. were characterised in patients with candidiasis. The antifungal activities of hBD-3 and fluconazole against C. glabrata were evaluated using Broth microdilution assay. The synergistic activity of these two agents was determined by checkerboard microdilution and time-killing assays. The cytotoxicity of hBD-3 was evaluated using LDH-cytotoxicity colorimetric assay. Of 307 episodes from 254 patients diagnosed with candidiasis, C. glabrata was found in 21 clinical isolates. Antifungal susceptibility tests of C. glabrata were performed, fluconazole demonstrated an inhibitory effect at concentrations of 0.25-8 μg/ml, but one antifungal resistant strain was identified (>64 μg/ml). hBD-3 showed an inhibitory effect against all selected strains at concentrations of 50-75 μg/ml and exhibited a synergistic effect with fluconazole at the fractional inhibitory concentration index (FICI) of 0.25-0.50. A concentration of 25 μg/ml of hBD-3 alone showed no cytotoxicity but synergistic activity was seen with fluconazole. In conclusion, hBD-3 has antifungal activity against C. glabrata and synergistic effects with fluconazole at concentrations that alone, have no cytotoxicity. hBD-3 could be used as an adjunctive therapy with first-line antifungal agents for patients with C. glabrata infection particularly those infected with fluconazole-resistant strains.
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Affiliation(s)
- Thananya Inthanachai
- Translational Research in Inflammation and Immunology Research Unit, Faculty of Medicine, Chulalongkorn University , Bangkok, Thailand
- Medical Microbiology, Interdisciplinary Program, Graduate School, Chulalongkorn University, Bangkok, Thailand
| | - Arsa Thammahong
- Mycology Unit, Department of Microbiology, Faculty of Medicine
| | - Steven W Edwards
- Institute of Integrative Biology, University of Liverpool , Liverpool, UK
| | - Sita Virakul
- Department of Microbiology, Faculty of Science, Antimicrobial Resistance and Stewardship Research Unit, Chulalongkorn University , Bangkok, Thailand
| | | | - Direkrit Chiewchengchol
- Translational Research in Inflammation and Immunology Research Unit, Faculty of Medicine, Chulalongkorn University , Bangkok, Thailand
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24
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Abstract
In order to preserve genome integrity, all cells must mount appropriate responses to DNA damage, including slowing down or arresting the cell cycle to give the cells time to repair the damage and changing gene expression, for example to induce genes involved in DNA repair. The Rad53 protein kinase is a conserved central mediator of these responses in eukaryotic cells, and its extensive phosphorylation upon DNA damage is necessary for its activation and subsequent activity. DNA damage checkpoints are key guardians of genome integrity. Eukaryotic cells respond to DNA damage by triggering extensive phosphorylation of Rad53/CHK2 effector kinase, whereupon activated Rad53/CHK2 mediates further aspects of checkpoint activation, including cell cycle arrest and transcriptional changes. Budding yeast Candida glabrata, closely related to model eukaryote Saccharomyces cerevisiae, is an opportunistic pathogen characterized by high genetic diversity and rapid emergence of drug-resistant mutants. However, the mechanisms underlying this genetic variability are unclear. We used Western blotting and mass spectrometry to show that, unlike S. cerevisiae, C. glabrata cells exposed to DNA damage did not induce C. glabrata Rad53 (CgRad53) phosphorylation. Furthermore, flow cytometry analysis showed that, unlike S. cerevisiae, C. glabrata cells did not accumulate in S phase upon DNA damage. Consistent with these observations, time-lapse microscopy showed C. glabrata cells continuing to divide in the presence of DNA damage, resulting in mitotic errors and cell death. Finally, transcriptome sequencing (RNAseq) analysis revealed transcriptional rewiring of the DNA damage response in C. glabrata and identified several key protectors of genome stability upregulated by DNA damage in S. cerevisiae but downregulated in C. glabrata, including proliferating cell nuclear antigen (PCNA). Together, our results reveal a noncanonical fungal DNA damage response in C. glabrata, which may contribute to rapidly generating genetic change and drug resistance.
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25
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Arastehfar A, Gabaldón T, Garcia-Rubio R, Jenks JD, Hoenigl M, Salzer HJF, Ilkit M, Lass-Flörl C, Perlin DS. Drug-Resistant Fungi: An Emerging Challenge Threatening Our Limited Antifungal Armamentarium. Antibiotics (Basel) 2020; 9:antibiotics9120877. [PMID: 33302565 PMCID: PMC7764418 DOI: 10.3390/antibiotics9120877] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 11/02/2020] [Accepted: 12/03/2020] [Indexed: 12/14/2022] Open
Abstract
The high clinical mortality and economic burden posed by invasive fungal infections (IFIs), along with significant agricultural crop loss caused by various fungal species, has resulted in the widespread use of antifungal agents. Selective drug pressure, fungal attributes, and host- and drug-related factors have counteracted the efficacy of the limited systemic antifungal drugs and changed the epidemiological landscape of IFIs. Species belonging to Candida, Aspergillus, Cryptococcus, and Pneumocystis are among the fungal pathogens showing notable rates of antifungal resistance. Drug-resistant fungi from the environment are increasingly identified in clinical settings. Furthermore, we have a limited understanding of drug class-specific resistance mechanisms in emerging Candida species. The establishment of antifungal stewardship programs in both clinical and agricultural fields and the inclusion of species identification, antifungal susceptibility testing, and therapeutic drug monitoring practices in the clinic can minimize the emergence of drug-resistant fungi. New antifungal drugs featuring promising therapeutic profiles have great promise to treat drug-resistant fungi in the clinical setting. Mitigating antifungal tolerance, a prelude to the emergence of resistance, also requires the development of effective and fungal-specific adjuvants to be used in combination with systemic antifungals.
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Affiliation(s)
- Amir Arastehfar
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA; (A.A.); (R.G.-R.)
| | - Toni Gabaldón
- Life Sciences Programme, Supercomputing Center (BSC-CNS), Jordi Girona, 08034 Barcelona, Spain;
- Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB), 08024 Barcelona, Spain
- Catalan Institution for Research and Advanced Studies. Pg. Lluís Companys 23, 08010 Barcelona, Spain
| | - Rocio Garcia-Rubio
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA; (A.A.); (R.G.-R.)
| | - Jeffrey D. Jenks
- Department of Medicine, University of California San Diego, San Diego, CA 92103, USA;
- Clinical and Translational Fungal-Working Group, University of California San Diego, La Jolla, CA 92093, USA;
- Division of Infectious Diseases and Global Public Health, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Martin Hoenigl
- Clinical and Translational Fungal-Working Group, University of California San Diego, La Jolla, CA 92093, USA;
- Division of Infectious Diseases and Global Public Health, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
- Section of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria
| | | | - Macit Ilkit
- Division of Mycology, University of Çukurova, 01330 Adana, Turkey
- Correspondence: (M.I.); (D.S.P.); Tel.: +90-532-286-0099 (M.I.); +1-201-880-3100 (D.S.P.)
| | - Cornelia Lass-Flörl
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria;
| | - David S. Perlin
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA; (A.A.); (R.G.-R.)
- Correspondence: (M.I.); (D.S.P.); Tel.: +90-532-286-0099 (M.I.); +1-201-880-3100 (D.S.P.)
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26
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Nywening AV, Rybak JM, Rogers PD, Fortwendel JR. Mechanisms of triazole resistance in Aspergillus fumigatus. Environ Microbiol 2020; 22:4934-4952. [PMID: 33047482 PMCID: PMC7828461 DOI: 10.1111/1462-2920.15274] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 10/07/2020] [Accepted: 10/07/2020] [Indexed: 12/11/2022]
Abstract
The ubiquitous fungal pathogen Aspergillus fumigatus is the primary cause of opportunistic mould infections in humans. Aspergilli disseminate via asexual conidia passively travelling through air currents to germinate within a broad range of environs, wherever suitable nutrients are found. Though the average human inhales hundreds of conidia daily, A. fumigatus invasive infections primarily affect the immunocompromised. At-risk individuals can develop often fatal invasive disease for which therapeutic options are limited. Regrettably, the global insurgence of isolates resistant to the triazoles, the frontline antifungal class used in medicine and agriculture to control A. fumigatus, is complicating the treatment of patients. Triazole antifungal resistance in A. fumigatus has become recognized as a global, yet poorly comprehended, problem. Due to a multitude of factors, the magnitude of resistant infections and their contribution to treatment outcomes are likely underestimated. Current studies suggest that human drug-resistant infections can be either environmentally acquired or de novo host selected during patient therapy. While much concerning development of resistance is yet unknown, recent investigations have revealed assorted underlying mechanisms enabling triazole resistance within individual clinical and environmental isolates. This review will provide an overview of triazole resistance as it is currently understood, as well as highlight some of the prominent biological mechanisms associated with clinical and environmental resistance to triazoles in A. fumigatus.
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Affiliation(s)
- Ashley V Nywening
- Department of Clinical Pharmacy and Translational Sciences, The University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, TN, USA
- College of Graduate Health Sciences, Integrated Biomedical Sciences Program, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Jeffrey M Rybak
- Department of Clinical Pharmacy and Translational Sciences, The University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, TN, USA
| | - Phillip David Rogers
- Department of Clinical Pharmacy and Translational Sciences, The University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, TN, USA
| | - Jarrod R Fortwendel
- Department of Clinical Pharmacy and Translational Sciences, The University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, TN, USA
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27
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Arastehfar A, Hilmioğlu-Polat S, Daneshnia F, Hafez A, Salehi M, Polat F, Yaşar M, Arslan N, Hoşbul T, Ünal N, Metin DY, Gürcan Ş, Birinci A, Koç AN, Pan W, Ilkit M, Perlin DS, Lass-Flörl C. Recent Increase in the Prevalence of Fluconazole-Non-susceptible Candida tropicalis Blood Isolates in Turkey: Clinical Implication of Azole-Non-susceptible and Fluconazole Tolerant Phenotypes and Genotyping. Front Microbiol 2020; 11:587278. [PMID: 33123116 PMCID: PMC7573116 DOI: 10.3389/fmicb.2020.587278] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 09/07/2020] [Indexed: 12/18/2022] Open
Abstract
Candida tropicalis is the fourth leading cause of candidemia in Turkey. Although C. tropicalis isolates from 1997 to 2017 were characterized as fully susceptible to antifungals, the increasing global prevalence of azole-non-susceptible (ANS) C. tropicalis and the association between high fluconazole tolerance (HFT) and fluconazole therapeutic failure (FTF) prompted us to re-evaluate azole susceptibility of C. tropicalis in Turkey. In this study, 161 C. tropicalis blood isolates from seven clinical centers were identified by ITS rDNA sequencing, genotyped by multilocus microsatellite typing, and tested for susceptibility to five azoles, two echinocandins, and amphotericin B (AMB); antifungal resistance mechanisms were assessed by sequencing of ERG11 and FKS1 genes. The results indicated that C. tropicalis isolates, which belonged to 125 genotypes grouped into 11 clusters, were fully susceptible to echinocandins and AMB; however, 18.6% of them had the ANS phenotype but only two carried the ANS-conferring mutation (Y132F). HFT was recorded in 52 isolates, 10 of which were also ANS. Large proportions of patients infected with ANS and HFT isolates (89 and 40.7%, respectively) showed FTF. Patients infected with azole-susceptible or ANS isolates did not differ in mortality, which, however, was significantly lower for those infected with HFT isolates (P = 0.007). There were significant differences in mortality (P = 0.02), ANS (P = 0.012), and HFT (P = 0.007) among genotype clusters. The alarming increase in the prevalence of C. tropicalis blood isolates with ANS and HFT in Turkey and the notable FTF rate should be a matter of public health concern.
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Affiliation(s)
- Amir Arastehfar
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, United States
| | | | | | | | - Mohammadreza Salehi
- Department of Infectious Diseases and Tropical Medicine, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Furkan Polat
- Department of Microbiology, Faculty of Medicine, Ege University, Izmir, Turkey
| | - Melike Yaşar
- Department of Microbiology, Faculty of Medicine, Ege University, Izmir, Turkey
| | - Nazlı Arslan
- Department of Microbiology, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey
| | - Tuğrul Hoşbul
- Department of Microbiology, Gulhane Training and Research Hospital, University of Health Sciences, Ankara, Turkey
| | - Nevzat Ünal
- Division of Mycology, Faculty of Medicine, Çukurova University, Adana, Turkey.,Department of Microbiology, Adana City Hospital, University of Health Sciences, Adana, Turkey
| | - Dilek Yeşim Metin
- Department of Microbiology, Faculty of Medicine, Ege University, Izmir, Turkey
| | - Şaban Gürcan
- Department of Microbiology, Faculty of Medicine, Trakya University, Edirne, Turkey
| | - Asuman Birinci
- Department of Microbiology, Faculty of Medicine, Ondokuz Mayis University, Samsun, Turkey
| | - Ayşe Nedret Koç
- Department of Microbiology, Faculty of Medicine, Erciyes University, Kayseri, Turkey
| | - Weihua Pan
- Shanghai Key Laboratory Molecular Medical Mycology, Shanghai, China
| | - Macit Ilkit
- Division of Mycology, Faculty of Medicine, Çukurova University, Adana, Turkey
| | - David S Perlin
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, United States
| | - Cornelia Lass-Flörl
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
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28
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Arastehfar A, Lass-Flörl C, Garcia-Rubio R, Daneshnia F, Ilkit M, Boekhout T, Gabaldon T, Perlin DS. The Quiet and Underappreciated Rise of Drug-Resistant Invasive Fungal Pathogens. J Fungi (Basel) 2020; 6:E138. [PMID: 32824785 PMCID: PMC7557958 DOI: 10.3390/jof6030138] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 07/22/2020] [Accepted: 08/11/2020] [Indexed: 12/13/2022] Open
Abstract
Human fungal pathogens are attributable to a significant economic burden and mortality worldwide. Antifungal treatments, although limited in number, play a pivotal role in decreasing mortality and morbidities posed by invasive fungal infections (IFIs). However, the recent emergence of multidrug-resistant Candida auris and Candida glabrata and acquiring invasive infections due to azole-resistant C. parapsilosis, C. tropicalis, and Aspergillus spp. in azole-naïve patients pose a serious health threat considering the limited number of systemic antifungals available to treat IFIs. Although advancing for major fungal pathogens, the understanding of fungal attributes contributing to antifungal resistance is just emerging for several clinically important MDR fungal pathogens. Further complicating the matter are the distinct differences in antifungal resistance mechanisms among various fungal species in which one or more mechanisms may contribute to the resistance phenotype. In this review, we attempt to summarize the burden of antifungal resistance for selected non-albicansCandida and clinically important Aspergillus species together with their phylogenetic placement on the tree of life. Moreover, we highlight the different molecular mechanisms between antifungal tolerance and resistance, and comprehensively discuss the molecular mechanisms of antifungal resistance in a species level.
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Affiliation(s)
- Amir Arastehfar
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA;
| | - Cornelia Lass-Flörl
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria;
| | - Rocio Garcia-Rubio
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA;
| | - Farnaz Daneshnia
- Westerdijk Fungal Biodiversity Institute, 3584 CT Utrecht, The Netherlands; (F.D.); (T.B.)
| | - Macit Ilkit
- Division of Mycology, University of Çukurova, 01330 Adana, Turkey;
| | - Teun Boekhout
- Westerdijk Fungal Biodiversity Institute, 3584 CT Utrecht, The Netherlands; (F.D.); (T.B.)
- Institute of Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, 1012 WX Amsterdam, The Netherlands
| | - Toni Gabaldon
- Life Sciences Programme, Barcelona, Supercomputing Center (BSC-CNS), Jordi Girona, 08034 Barcelona, Spain;
- Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB), 08024 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
| | - David S. Perlin
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA;
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Candida albicans Genetic Background Influences Mean and Heterogeneity of Drug Responses and Genome Stability during Evolution in Fluconazole. mSphere 2020; 5:5/3/e00480-20. [PMID: 32581072 PMCID: PMC7316494 DOI: 10.1128/msphere.00480-20] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Antimicrobial resistance is an evolutionary phenomenon with clinical implications. We tested how replicates from diverse strains of Candida albicans, a prevalent human fungal pathogen, evolve in the commonly prescribed antifungal drug fluconazole. Replicates on average increased in fitness in the level of drug they were evolved to, with the least fit parental strains improving the most. Very few replicates increased resistance above the drug level they were evolved in. Notably, many replicates increased in genome size and changed in drug tolerance (a drug response where a subpopulation of cells grow slowly in high levels of drug), and variability among replicates in fitness, tolerance, and genome size was higher in strains that initially were more sensitive to the drug. Genetic background influenced the average degree of adaptation and the evolved variability of many phenotypes, highlighting that different strains from the same species may respond and adapt very differently during adaptation. The importance of within-species diversity in determining the evolutionary potential of a population to evolve drug resistance or tolerance is not well understood, including in eukaryotic pathogens. To examine the influence of genetic background, we evolved replicates of 20 different clinical isolates of Candida albicans, a human fungal pathogen, in fluconazole, the commonly used antifungal drug. The isolates hailed from the major C. albicans clades and had different initial levels of drug resistance and tolerance to the drug. The majority of replicates rapidly increased in fitness in the evolutionary environment, with the degree of improvement inversely correlated with parental strain fitness in the drug. Improvement was largely restricted to up to the evolutionary level of drug: only 4% of the evolved replicates increased resistance (MIC) above the evolutionary level of drug. Prevalent changes were altered levels of drug tolerance (slow growth of a subpopulation of cells at drug concentrations above the MIC) and increased diversity of genome size. The prevalence and predominant direction of these changes differed in a strain-specific manner, but neither correlated directly with parental fitness or improvement in fitness. Rather, low parental strain fitness was correlated with high levels of heterogeneity in fitness, tolerance, and genome size among evolved replicates. Thus, parental strain background is an important determinant in mean improvement to the evolutionary environment as well as the diversity of evolved phenotypes, and the range of possible responses of a pathogen to an antimicrobial drug cannot be captured by in-depth study of a single strain background. IMPORTANCE Antimicrobial resistance is an evolutionary phenomenon with clinical implications. We tested how replicates from diverse strains of Candida albicans, a prevalent human fungal pathogen, evolve in the commonly prescribed antifungal drug fluconazole. Replicates on average increased in fitness in the level of drug they were evolved to, with the least fit parental strains improving the most. Very few replicates increased resistance above the drug level they were evolved in. Notably, many replicates increased in genome size and changed in drug tolerance (a drug response where a subpopulation of cells grow slowly in high levels of drug), and variability among replicates in fitness, tolerance, and genome size was higher in strains that initially were more sensitive to the drug. Genetic background influenced the average degree of adaptation and the evolved variability of many phenotypes, highlighting that different strains from the same species may respond and adapt very differently during adaptation.
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Arastehfar A, Daneshnia F, Najafzadeh MJ, Hagen F, Mahmoudi S, Salehi M, Zarrinfar H, Namvar Z, Zareshahrabadi Z, Khodavaisy S, Zomorodian K, Pan W, Theelen B, Kostrzewa M, Boekhout T, Lass-Flörl C. Evaluation of Molecular Epidemiology, Clinical Characteristics, Antifungal Susceptibility Profiles, and Molecular Mechanisms of Antifungal Resistance of Iranian Candida parapsilosis Species Complex Blood Isolates. Front Cell Infect Microbiol 2020; 10:206. [PMID: 32509592 PMCID: PMC7253641 DOI: 10.3389/fcimb.2020.00206] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 04/16/2020] [Indexed: 11/13/2022] Open
Abstract
Clonal expansion of fluconazole resistant (FLZ-R) Candida parapsilosis isolates is increasingly being identified in many countries, while there is no study exploring the antifungal susceptibility pattern, genetic diversity, and clinical information for Iranian C. parapsilosis blood isolates. Candida parapsilosis species complex blood isolates (n = 98) were recovered from nine hospitals located in three major cities, identified by MALDI-TOF MS, and their genetic relatedness was examined by AFLP fingerprinting. Antifungal susceptibility testing followed CLSI-M27-A3 and ERG11, MRR1 and hotspots 1/2 (HS1/2) of FKS1 were sequenced to assess the azole and echinocandin resistance mechanisms, respectively. Ninety-four C. parapsilosis and four Candida orthopsilosis isolates were identified from 90 patients. Only 43 patients received systemic antifungal drugs with fluconazole as the main antifungal used. The overall mortality rate was 46.6% (42/90) and death mostly occurred for those receiving systemic antifungals (25/43) relative to those not treated (17/47). Although, antifungal-resistance was rare, one isolate was multidrug-resistant (FLZ = 16 μg/ml and micafungin = 8 μg/ml) and the infected patient showed therapeutic failure to FLZ prophylaxis. Mutations causing azole and echinocandin resistance were not found in the genes studied. AFLP revealed five genotypes (G) and G1 was the main one (59/94; 62.7%). Clinical outcome was significantly associated with city (P = 0.02, α <0.05) and Mashhad was significantly associated with mortality (P = 0.03, α <0.05). Overall, we found a low level of antifungal resistance for Iranian C. parapsilosis blood isolates, but the noted MDR strain can potentially become the source of future infections and challenge the antifungal therapy in antifungal-naïve patients. AFLP typing results warrants confirmation using other resolutive typing methods.
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Affiliation(s)
- Amir Arastehfar
- Yeast Biodiversity Department, Westerdijk Fungal Biodiversity Institute, Utrecht, Netherlands
| | - Farnaz Daneshnia
- Yeast Biodiversity Department, Westerdijk Fungal Biodiversity Institute, Utrecht, Netherlands
| | - Mohammad Javad Najafzadeh
- Department of Parasitology and Mycology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ferry Hagen
- Yeast Biodiversity Department, Westerdijk Fungal Biodiversity Institute, Utrecht, Netherlands.,Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, Netherlands.,Laboratory of Medical Mycology, Jining No. 1 People's Hospital, Jining, China
| | - Shahram Mahmoudi
- Department of Medical Parasitology and Mycology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammadreza Salehi
- Department of Infectious Diseases and Tropical Medicine, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Hossein Zarrinfar
- Allergy Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Zahra Namvar
- Department of Microbiology, School of Biological Sciences, Islamic Azad University, Tehran, Iran
| | - Zahra Zareshahrabadi
- Basic Sciences in Infectious Diseases Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Sadegh Khodavaisy
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, 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, China
| | - Bart Theelen
- Yeast Biodiversity Department, Westerdijk Fungal Biodiversity Institute, Utrecht, Netherlands
| | | | - Teun Boekhout
- Yeast Biodiversity Department, Westerdijk Fungal Biodiversity Institute, Utrecht, Netherlands.,Institute of Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, Netherlands
| | - Cornelia Lass-Flörl
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
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Megri Y, Arastehfar A, Boekhout T, Daneshnia F, Hörtnagl C, Sartori B, Hafez A, Pan W, Lass-Flörl C, Hamrioui B. Candida tropicalis is the most prevalent yeast species causing candidemia in Algeria: the urgent need for antifungal stewardship and infection control measures. Antimicrob Resist Infect Control 2020; 9:50. [PMID: 32264966 PMCID: PMC7140370 DOI: 10.1186/s13756-020-00710-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 03/24/2020] [Indexed: 12/29/2022] Open
Abstract
Background Despite being associated with a high mortality and economic burden, data regarding candidemia are scant in Algeria. The aim of this study was to unveil the epidemiology of candidemia in Algeria, evaluate the antifungal susceptibility pattern of causative agents and understand the molecular mechanisms of antifungal resistance where applicable. Furthermore, by performing environmental screening and microsatellite typing we sought to identify the source of infection. Methods We performed a retrospective epidemiological-based surveillance study and collected available blood yeast isolates recovered from the seven hospitals in Algiers. To identify the source of infection, we performed environmental screening from the hands of healthcare workers (HCWs) and high touch areas. Species identification was performed by API Auxa-Color and MALDI-TOF MS and ITS sequencing was performed for species not reliably identified by MALDI-TOF MS. Antifungal susceptibility testing followed CLSI M27-A3/S4 and included all blood and environmental yeast isolates. ERG11 sequencing was performed for azole-resistant Candida isolates. Microsatellite typing was performed for blood and environmental Candida species, where applicable. Results Candida tropicalis (19/66) was the main cause of candidemia in these seven hospitals, followed by Candida parapsilosis (18/66), Candida albicans (18/66), and Candida glabrata (7/66). The overall mortality rate was 68.6% (35/51) and was 81.2% for C. tropicalis-infected patients (13/16). Fluconazole was the main antifungal drug used (12/51); 41% of the patients (21/51) did not receive any systemic treatment. Candida parapsilosis was isolated mainly from the hands of HCWs (7/28), and various yeasts were collected from high-touch areas (11/47), including Naganishia albida, C. parapsilosis and C. glabrata. Typing data revealed interhospital transmission on two occasions for C. parapsilosis and C. glabrata, and the same clone of C. parapsilosis infected two patients within the same hospital. Resistance was only noted for C. tropicalis against azoles (6/19) and fluconazole-resistant C. tropicalis isolates (≥8 μg/ml) (6/19) contained a novel P56S (5/6) amino acid substitution and a previously reported one (V234F; 1/6) in Erg11p. Conclusions Collectively, our data suggest an urgent need for antifungal stewardship and infection control strategies to improve the clinical outcome of Algerian patients with candidemia. The high prevalence of C. tropicalis joined by fluconazole-resistance may hamper the therapeutic efficacy of fluconazole, the frontline antifungal drug used in Algeria.
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Affiliation(s)
- Youcef Megri
- Parasitology and Mycology Department, Mustapha University Hospital, 16000, Algiers, Algeria
| | - Amir Arastehfar
- Yeast Department, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands. .,Institute of Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands.
| | - Teun Boekhout
- Yeast Department, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands.,Institute of Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands
| | - Farnaz Daneshnia
- Yeast Department, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - Caroline Hörtnagl
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Bettina Sartori
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Ahmed Hafez
- Biotechvana, 46980, Paterna, Valencia, Spain
| | - Weihua Pan
- Shanghai Key Laboratory Molecular Medical Mycology, Shanghai, 200003, China.
| | - Cornelia Lass-Flörl
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Boussad Hamrioui
- Parasitology and Mycology Department, Mustapha University Hospital, 16000, Algiers, Algeria
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Novak AR, Bradley ME, Kiser TH, Mueller SW. Azole-resistant Aspergillus and Echinocandin-resistant Candida - What are the treatment options? CURRENT FUNGAL INFECTION REPORTS 2020; 14:141-152. [PMID: 32699568 DOI: 10.1007/s12281-020-00379-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Purpose of Review This review summarizes current treatment options for echinocandin-resistant Candida spp. (ERC) and azole-resistant Aspergillus fumigatus (ARAF), emphasizing recent in vitro/in vivo data, clinical reports, and consensus statements. Recent Findings Advances in ERC and ARAF treatment are limited to specific antifungal combinations and dose optimization but remain reliant on amphotericin products. Although novel antifungals may provide breakthroughs in the treatment of resistant fungi, these agents are not yet available. Early identification and appropriate treatment remain a paramount, albeit elusive, task. Summary When either ERC or ARAF are suspected or proven, amphotericin products remain the cornerstone of initial therapy. For ERC, azoles are de-escalation options for susceptible isolates in stable patients to avoid amphotericin toxicities. Although combination echinocandin with high-dose salvage posaconazole or isavuconazole may be attempted in ARAF, it requires careful consideration following patient stabilization. Future research defining optimal therapies and early identification of ERC and ARAF is of extreme importance.
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Affiliation(s)
- Alison R Novak
- Department of Clinical Pharmacy, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, 12850 East Montview Boulevard, Mail Stop C238, Aurora, CO 80045, USA
| | - Mary E Bradley
- Department of Clinical Pharmacy, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, 12850 East Montview Boulevard, Mail Stop C238, Aurora, CO 80045, USA
| | - Tyree H Kiser
- Department of Clinical Pharmacy, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, 12850 East Montview Boulevard, Mail Stop C238, Aurora, CO 80045, USA
| | - Scott W Mueller
- Department of Clinical Pharmacy, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, 12850 East Montview Boulevard, Mail Stop C238, Aurora, CO 80045, USA
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Billmyre RB, Applen Clancey S, Li LX, Doering TL, Heitman J. 5-fluorocytosine resistance is associated with hypermutation and alterations in capsule biosynthesis in Cryptococcus. Nat Commun 2020; 11:127. [PMID: 31913284 PMCID: PMC6949227 DOI: 10.1038/s41467-019-13890-z] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 11/29/2019] [Indexed: 12/27/2022] Open
Abstract
Patients infected with the fungal pathogen Cryptococcus are most effectively treated with a combination of 5-fluorocytosine (5FC) and amphotericin B. 5FC acts as a prodrug, which is converted into toxic 5-fluorouracil (5FU) upon uptake into fungal cells. However, the pathogen frequently develops resistance through unclear mechanisms. Here we show that resistance to 5FC in Cryptococcus deuterogattii is acquired more frequently in isolates with defects in DNA mismatch repair that confer an elevated mutation rate. We use whole genome sequencing of 16 independent isolates to identify mutations associated with 5FC resistance in vitro. We find mutations in known resistance genes (FUR1 and FCY2) and in a gene UXS1, previously shown to encode an enzyme that converts UDP-glucuronic acid to UDP-xylose for capsule biosynthesis, but not known to play a role in 5FC metabolism. Mutations in UXS1 lead to accumulation of UDP-glucuronic acid and alterations in nucleotide metabolism, which appear to suppress toxicity of both 5FC and its toxic derivative 5FU. The authors show that resistance to the antifungal 5-fluorocytosine in Cryptococcus deuterogattii is acquired more frequently in isolates with elevated mutation rate, and is associated with alterations in capsule biosynthesis and nucleotide metabolism.
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Affiliation(s)
- R Blake Billmyre
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA.,Stowers Institute for Medical Research, 1000 E 50th St., Kansas City, MO, 64110, USA
| | - Shelly Applen Clancey
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA
| | - Lucy X Li
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Tamara L Doering
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA.
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Gabaldón T, Gómez-Molero E, Bader O. Molecular Typing of Candida glabrata. Mycopathologia 2019; 185:755-764. [PMID: 31617105 DOI: 10.1007/s11046-019-00388-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 09/21/2019] [Indexed: 12/17/2022]
Abstract
The yeast Candida glabrata has emerged, second only to Candida albicans, to be one of the most frequently isolated fungi in clinical specimen from human. Its frequent resistance towards azole antifungal drugs and the high capacity to form biofilms on indwelling catheters of individual isolates render it an often difficult to treat pathogen. Hence, there is a notably increasing scientific and clinical interest in this species. This has led to the development of a variety of molecular tools for genetic modification, strain collections, and last but not least different approaches to analyse the population structure among isolates of different geographical and clinical contexts. Often, these are used to study correlations (or the absence thereof) with different pathogenicity, virulence, or drug resistance traits. Three molecular methods have been used to type within the C. glabrata population on a genetic level by multiple studies: multi-locus sequence typing, microsatellite length polymorphisms, and clustering of whole-genome sequencing data, and these are subject of this review.
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Affiliation(s)
- Toni Gabaldón
- Comparative Genomics Group, Life Science Programme, Barcelona Supercomputing Centre (BSC-CNS), Barcelona, Spain
- Institute of Research in Biomedicine (IRB), Barcelona, Spain
- Institució Catalana de Recerca I Estudis Avançats (ICREA), Barcelona, Spain
| | - Emilia Gómez-Molero
- Institute for Medical Microbiology, University Medical Center Göttingen, Kreuzbergring 57, 37075, Göttingen, Germany
| | - Oliver Bader
- Institute for Medical Microbiology, University Medical Center Göttingen, Kreuzbergring 57, 37075, Göttingen, Germany.
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Anidulafungin Susceptibility Testing of Candida glabrata Isolates from Blood Cultures by the MALDI Biotyper Antibiotic (Antifungal) Susceptibility Test Rapid Assay. Antimicrob Agents Chemother 2019; 63:AAC.00554-19. [PMID: 31285227 DOI: 10.1128/aac.00554-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 06/28/2019] [Indexed: 12/16/2022] Open
Abstract
Echinocandins are the recommended first-line antifungals for treatment of invasive candidiasis. The increasing number of Candida glabrata strains resistant against echinocandins is an emerging health care concern. The rapid detection of resistant C. glabrata isolates is an urgent requirement for clinical laboratories. In this study, we developed the MALDI Biotyper antibiotic (antifungal) susceptibility test rapid assay (MBT ASTRA) for the rapid detection of anidulafungin-resistant C. glabrata isolates directly from positive blood cultures. Of 100 C. glabrata strains, MBT ASTRA classified 69 as susceptible and 29 as resistant. Microdilution assays performed according to the Clinical and Laboratory Standards Institute (CLSI) guidelines, used as a standard reference, identified 65 susceptible, 9 intermediate, and 26 resistant isolates. Sequencing of hot spot 1 and hot spot 2 regions of the FKS1 and FKS2 genes classified 86 susceptible and 14 resistant isolates. The MBT ASTRA had sensitivity and specificity of 80% and 95%, respectively, compared to the microdilution method. Positive and negative agreement of MBT ASTRA was calculated at 100% and 80%, respectively, compared with the molecular sequencing approach. Together, these results revealed a high accuracy of MBT ASTRA compared to microdilution according to the CLSI and PCR analysis, resulting in a categorical agreement of 90% and 83%, respectively. The validity of MBT ASTRA was 98%. Importantly, MBT ASTRA provided antifungal susceptibility testing (AFST) within 6 h that was both accurate and reliable compared to the other two approaches, which require at least 24 h or are costly. Therefore, this method has the potential to facilitate clinical AFST rapidly at low sample costs for clinical labs already equipped with matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS).
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The Aspergillus fumigatus Mismatch Repair MSH2 Homolog Is Important for Virulence and Azole Resistance. mSphere 2019; 4:4/4/e00416-19. [PMID: 31391280 PMCID: PMC6686229 DOI: 10.1128/msphere.00416-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Invasive aspergillosis (IA) has emerged as one of the most common life-threatening fungal diseases in immunocompromised patients, with mortality rates as high as 90%. Systemic fungal infections such as IA are usually treated with triazoles; however, epidemiological research has shown that the prevalence of azole-resistant Aspergillus fumigatus isolates has increased significantly over the last decade. There is very little information about the importance of genomic stability for A. fumigatus population structure, azole resistance, and virulence. Here, we decided to investigate whether the mismatch repair system could influence A. fumigatus azole resistance and virulence, focusing on one of the components of this system, MSH2. Although the mutation frequency of mshA (the A. fumigatusMSH2 homologue) is low in environmental and clinical isolates, our results indicate that loss of mshA function can provide increased azole resistance and virulence when selected for. These results demonstrate the importance of genetic instability in A. fumigatus as a possible mechanism of evolving azole resistance and establishing fitness in the host. The genetic stability of every living organism depends on accurate DNA replication and repair systems. Here, we investigated the Aspergillus fumigatusMSH2 mismatch repair (MMR) gene MshA and how it impacts virulence and the evolution of azole resistance. We examined mshA gene variation in 62 environmental and clinical A. fumigatus strains. We have observed 12 strains with variants (18.2%), and 8 strains among them showed missense variants. We demonstrated that A. fumigatusmshA null mutants are haploid and have conserved karyotypes with discrete gross chromosomal rearrangements. The ΔmshA strains are not sensitive to several DNA-damaging agents. The lack of mshA caused a significant reduction of virulence of A. fumigatus in a neutropenic murine model of invasive pulmonary aspergillosis and in the invertebrate alternative model Galleria mellonella. Wild-type and ΔmshA populations did not show any significant changes in drug resistance acquisition after they were transferred 10 times in minimal medium in the absence of any stress. However, these populations rapidly acquired virulence in the ΔmshA background and high levels of resistance to posaconazole in the presence of this drug (at least 200-fold-higher levels of resistance than those derived from the wild-type strain). Taken together, these results suggest that genetic instability caused by ΔmshA mutations can confer an adaptive advantage, mainly increasing posaconazole resistance and virulence acquisition. IMPORTANCE Invasive aspergillosis (IA) has emerged as one of the most common life-threatening fungal diseases in immunocompromised patients, with mortality rates as high as 90%. Systemic fungal infections such as IA are usually treated with triazoles; however, epidemiological research has shown that the prevalence of azole-resistant Aspergillus fumigatus isolates has increased significantly over the last decade. There is very little information about the importance of genomic stability for A. fumigatus population structure, azole resistance, and virulence. Here, we decided to investigate whether the mismatch repair system could influence A. fumigatus azole resistance and virulence, focusing on one of the components of this system, MSH2. Although the mutation frequency of mshA (the A. fumigatusMSH2 homologue) is low in environmental and clinical isolates, our results indicate that loss of mshA function can provide increased azole resistance and virulence when selected for. These results demonstrate the importance of genetic instability in A. fumigatus as a possible mechanism of evolving azole resistance and establishing fitness in the host.
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Mutation bias and GC content shape antimutator invasions. Nat Commun 2019; 10:3114. [PMID: 31308380 PMCID: PMC6629674 DOI: 10.1038/s41467-019-11217-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 06/28/2019] [Indexed: 02/02/2023] Open
Abstract
Mutators represent a successful strategy in rapidly adapting asexual populations, but theory predicts their eventual extinction due to their unsustainably large deleterious load. While antimutator invasions have been documented experimentally, important discrepancies among studies remain currently unexplained. Here we show that a largely neglected factor, the mutational idiosyncrasy displayed by different mutators, can play a major role in this process. Analysing phylogenetically diverse bacteria, we find marked and systematic differences in the protein-disruptive effects of mutations caused by different mutators in species with different GC compositions. Computer simulations show that these differences can account for order-of-magnitude changes in antimutator fitness for a realistic range of parameters. Overall, our results suggest that antimutator dynamics may be highly dependent on the specific genetic, ecological and evolutionary history of a given population. This context-dependency further complicates our understanding of mutators in clinical settings, as well as their role in shaping bacterial genome size and composition.
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Rivero-Menendez O, Navarro-Rodriguez P, Bernal-Martinez L, Martin-Cano G, Lopez-Perez L, Sanchez-Romero I, Perez-Ayala A, Capilla J, Zaragoza O, Alastruey-Izquierdo A. Clinical and Laboratory Development of Echinocandin Resistance in Candida glabrata: Molecular Characterization. Front Microbiol 2019; 10:1585. [PMID: 31354675 PMCID: PMC6637773 DOI: 10.3389/fmicb.2019.01585] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 06/25/2019] [Indexed: 12/29/2022] Open
Abstract
The pathogenic yeast Candida glabrata has become a public health issue due to the increasing number of echinocandin resistant clinical strains reported. In this study, acquisition and development of resistance to this antifungal class were studied in serial C. glabrata isolates from five patients admitted in two Spanish hospitals with a resistant profile against echinocandins associated with different mutations in hot-spot 1 of FKS2 gene. For two of these patients susceptible FKS wild-type isolates obtained prior to resistant ones were also investigated. Isolates were genotyped using multilocus sequence typing and microsatellite length polymorphism techniques, which yielded comparable results. Susceptible and resistant isolates from the same patient had the same genotype, being sequence type (ST) 3 the most prevalent among them. Isolates with different FKS mutations but the same ST were present in the same patient. MSH2 gene alterations were also studied to investigate their correlation with antifungal resistance acquisition but no association was found with antifungal resistance nor with specific genotypes. In vitro exposure to increasing concentrations of micafungin to susceptible isolates developed colonies carrying FKS mutations in agar plates containing a minimum concentration of 0.06 mg/L of micafungin after less than 48 h of exposure. We investigated the correlation between development of resistance and genotype in a set of susceptible strains after being in vitro exposed to micafungin and anidulafungin but no correlation was found. Mutant prevention concentration values and spontaneous growth frequencies after selection with both echinocandins were statistically similar, although FKS mutant colonies were more abundant after micafungin exposure (p < 0.001). Mutation S663P and F659 deletion were the most common ones found after selection with both echinocandins.
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Affiliation(s)
- Olga Rivero-Menendez
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Madrid, Spain
| | - Patricia Navarro-Rodriguez
- Unitat de Microbiologia, Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili, Tarragona, Spain
| | - Leticia Bernal-Martinez
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Madrid, Spain.,Spanish Network for the Research in Infectious Diseases (RD16CIII/0004/0003), Instituto de Salud Carlos III, Madrid, Spain
| | - Gema Martin-Cano
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Madrid, Spain
| | - Laura Lopez-Perez
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Madrid, Spain
| | | | | | - Javier Capilla
- Unitat de Microbiologia, Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili, Tarragona, Spain
| | - Oscar Zaragoza
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Madrid, Spain.,Spanish Network for the Research in Infectious Diseases (RD16CIII/0004/0003), Instituto de Salud Carlos III, Madrid, Spain
| | - Ana Alastruey-Izquierdo
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Madrid, Spain.,Spanish Network for the Research in Infectious Diseases (RD16CIII/0004/0003), Instituto de Salud Carlos III, Madrid, Spain
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Tetz G, Collins M, Vikina D, Tetz V. In Vitro Activity of a Novel Antifungal Compound, MYC-053, against Clinically Significant Antifungal-Resistant Strains of Candida glabrata, Candida auris, Cryptococcus neoformans, and Pneumocystis spp. Antimicrob Agents Chemother 2019; 63:e01975-18. [PMID: 30917977 PMCID: PMC6437499 DOI: 10.1128/aac.01975-18] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 01/12/2019] [Indexed: 01/28/2023] Open
Abstract
An urgent need exists for new antifungal compounds to treat fungal infections in immunocompromised patients. The aim of the current study was to investigate the potency of a novel antifungal compound, MYC-053, against the emerging yeast and yeast-like pathogens Candida glabrata, Candida auris, Cryptococcus neoformans, and Pneumocystis species. MYC-053 was equally effective against the susceptible control strains, clinical isolates, and resistant strains, with MICs of 0.125 to 4.0 μg/ml. Notably, unlike other antifungals such as azoles, polyenes, and echinocandins, MYC-053 was effective against Pneumocystis isolates, therefore being the only synthetic antifungal that may potentially be used against Pneumocystis spp., Candida spp., and Cryptococcus spp. MYC-053 was highly effective against preformed 48-h-old C. glabrata and C. neoformans biofilms, with minimal biofilm eradication concentrations equal to 1 to 4 times the MIC. Together, these data indicated that MYC-053 may be developed into a promising antifungal agent for the treatment and prevention of invasive fungal infections caused by yeasts and yeast-like fungi.
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Affiliation(s)
- G Tetz
- TGV-Therapeutics, New York, New York, USA
| | - M Collins
- Pulmonary Biology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - D Vikina
- Human Microbiology Institute, New York, New York, USA
| | - V Tetz
- Human Microbiology Institute, New York, New York, USA
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A Novel, Drug Resistance-Independent, Fluorescence-Based Approach To Measure Mutation Rates in Microbial Pathogens. mBio 2019; 10:mBio.00120-19. [PMID: 30808701 PMCID: PMC6391916 DOI: 10.1128/mbio.00120-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Measurements of mutation rates—i.e., how often proliferating cells acquire mutations in their DNA—are essential for understanding cellular processes that maintain genome stability. Many traditional mutation rate measurement assays are based on detecting mutations that cause resistance to a particular drug. Such assays typically work well for laboratory strains but have significant limitations when comparing clinical or environmental isolates that have various intrinsic levels of drug tolerance, which confounds the interpretation of results. Here we report the development and validation of a novel method of measuring mutation rates, which detects mutations that cause loss of fluorescence rather than acquisition of drug resistance. Using this method, we measured the mutation rates of clinical isolates of fungal pathogen Candida glabrata. This assay can be adapted to other organisms and used to compare mutation rates in contexts where unequal drug sensitivity is anticipated. All evolutionary processes are underpinned by a cellular capacity to mutate DNA. To identify factors affecting mutagenesis, it is necessary to compare mutation rates between different strains and conditions. Drug resistance-based mutation reporters are used extensively to measure mutation rates, but they are suitable only when the compared strains have identical drug tolerance levels—a condition that is not satisfied under many “real-world” circumstances, e.g., when comparing mutation rates among a series of environmental or clinical isolates. Candida glabrata is a fungal pathogen that shows a high degree of genetic diversity and fast emergence of antifungal drug resistance. To enable meaningful comparisons of mutation rates among C. glabrata clinical isolates, we developed a novel fluorescence-activated cell sorting-based approach to measure the mutation rate of a chromosomally integrated GFP gene. We found that in Saccharomyces cerevisiae this approach recapitulated the reported mutation rate of a wild-type strain and the mutator phenotype of a shu1Δ mutant. In C. glabrata, the GFP reporter captured the mutation rate increases caused either by a genotoxic agent or by deletion of DNA mismatch repair gene MSH2, as well as the specific mutational signature associated with msh2Δ. Finally, the reporter was used to measure the mutation rates of C. glabrata clinical isolates carrying different alleles of MSH2. Together, these results show that fluorescence-based mutation reporters can be used to measure mutation rates in microbes under conditions of unequal drug susceptibility to reveal new insights about drivers of mutagenesis.
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Potocki L, Depciuch J, Kuna E, Worek M, Lewinska A, Wnuk M. FTIR and Raman Spectroscopy-Based Biochemical Profiling Reflects Genomic Diversity of Clinical Candida Isolates That May Be Useful for Diagnosis and Targeted Therapy of Candidiasis. Int J Mol Sci 2019; 20:ijms20040988. [PMID: 30823514 PMCID: PMC6412866 DOI: 10.3390/ijms20040988] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Revised: 02/16/2019] [Accepted: 02/18/2019] [Indexed: 12/11/2022] Open
Abstract
Despite the fact that Candida albicans is documented to be the main cause of human candidiasis, non-C. albicans Candida (NCAC) species, such as Candida glabrata and Candida tropicalis, are also suggested to be implicated in the etiopathogenesis of opportunistic fungal infections. As biology, epidemiology, pathogenicity, and antifungal resistance of NCAC species may be affected as a result of genomic diversity and plasticity, rapid and unambiguous identification of Candida species in clinical samples is essential for proper diagnosis and therapy. In the present study, 25 clinical isolates of C. albicans, C. glabrata, and C. tropicalis species were characterized in terms of their karyotype patterns, DNA content, and biochemical features. Fourier transform infrared (FTIR) spectra- and Raman spectra-based molecular fingerprints corresponded to the diversity of chromosomal traits and DNA levels that provided correct species identification. Moreover, Raman spectroscopy was documented to be useful for the evaluation of ergosterol content that may be associated with azole resistance. Taken together, we found that vibrational spectroscopy-based biochemical profiling reflects the variability of chromosome patterns and DNA content of clinical Candida species isolates and may facilitate the diagnosis and targeted therapy of candidiasis.
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Affiliation(s)
- Leszek Potocki
- Department of Genetics, Faculty of Biotechnology, University of Rzeszow, Pigonia 1, 35-310 Rzeszow, Poland.
| | - Joanna Depciuch
- Institute of Nuclear Physics, Polish Academy of Sciences, 31-342 Krakow, Poland.
| | - Ewelina Kuna
- Department of Genetics, Faculty of Biotechnology, University of Rzeszow, Pigonia 1, 35-310 Rzeszow, Poland.
| | - Mariusz Worek
- Department of Microbiology, Faculty of Medicine, University of Rzeszow, 35-959 Rzeszow, Poland.
| | - Anna Lewinska
- Department of Cell Biochemistry, Faculty of Biotechnology, University of Rzeszow, 35-310 Rzeszow, Poland.
| | - Maciej Wnuk
- Department of Genetics, Faculty of Biotechnology, University of Rzeszow, Pigonia 1, 35-310 Rzeszow, Poland.
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Barber AE, Weber M, Kaerger K, Linde J, Gölz H, Duerschmied D, Markert A, Guthke R, Walther G, Kurzai O. Comparative Genomics of Serial Candida glabrata Isolates and the Rapid Acquisition of Echinocandin Resistance during Therapy. Antimicrob Agents Chemother 2019; 63:e01628-18. [PMID: 30478162 PMCID: PMC6355595 DOI: 10.1128/aac.01628-18] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 11/18/2018] [Indexed: 01/03/2023] Open
Abstract
The opportunistic pathogen Candida glabrata shows a concerning increase in drug resistance. Here, we present the analysis of two serial bloodstream isolates, obtained 12 days apart. Both isolates show pan-azole resistance and echinocandin resistance was acquired during the sampling interval. Genome sequencing identified nine nonsynonymous SNVs between the strains, including a S663P substitution in FKS2 and previously undescribed SNVs in MDE1 and FPR1, offering insight into how C. glabrata acquires drug resistance and adapts to a human host.
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Affiliation(s)
- Amelia E Barber
- National Reference Center for Invasive Mycoses, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany
| | - Michael Weber
- National Reference Center for Invasive Mycoses, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany
- Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany
- Research Group PiDOMICs, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany
| | - Kerstin Kaerger
- National Reference Center for Invasive Mycoses, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany
| | - Jörg Linde
- Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany
- Research Group PiDOMICs, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany
| | - Hanna Gölz
- Institute of Medical Microbiology and Hygiene, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Daniel Duerschmied
- Department of Cardiology and Angiology I, Heart Center, University of Freiburg, Freiburg, Germany
- Department of Medicine III: Medical Intensive Care, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Antonie Markert
- Department of Medicine III: Medical Intensive Care, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Reinhard Guthke
- Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany
| | - Grit Walther
- National Reference Center for Invasive Mycoses, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany
| | - Oliver Kurzai
- National Reference Center for Invasive Mycoses, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany
- Institute for Hygiene and Microbiology, Julius Maximilian University of Wuerzburg, Wuerzburg, Germany
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Inflammatory Cell Recruitment in Candida glabrata Biofilm Cell-Infected Mice Receiving Antifungal Chemotherapy. J Clin Med 2019; 8:jcm8020142. [PMID: 30691087 PMCID: PMC6406391 DOI: 10.3390/jcm8020142] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 01/12/2019] [Accepted: 01/20/2019] [Indexed: 12/14/2022] Open
Abstract
(1) Background: Due to a high rate of antifungal resistance, Candida glabrata is one of the most prevalent Candida spp. linked to systemic candidiasis, which is particularly critical in catheterized patients. The goal of this work was to simulate a systemic infection exclusively derived from C. glabrata biofilm cells and to evaluate the effectiveness of the treatment of two echinocandins—caspofungin (Csf) and micafungin (Mcf). (2) Methods: CD1 mice were infected with 48 h-biofilm cells of C. glabrata and then treated with Csf or Mcf. After 72 h, the efficacy of each drug was evaluated to assess the organ fungal burden through colony forming units (CFU) counting. The immune cell recruitment into target organs was evaluated by flow cytometry or histopathology analysis. (3) Results: Fungal burden was found to be higher in the liver than in the kidneys. However, none of the drugs was effective in completely eradicating C. glabrata biofilm cells. At the evaluated time point, flow cytometry analysis showed a predominant mononuclear response in the spleen, which was also evident in the liver and kidneys of the infected mice, as observed by histopathology analysis. (4) Conclusions: Echinocandins do not have a significant impact on liver and kidney fungal burden, or recruited inflammatory infiltrate, when mice are intravenously (i.v.) infected with C. glabrata biofilm-grown cells.
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Rad53- and Chk1-Dependent DNA Damage Response Pathways Cooperatively Promote Fungal Pathogenesis and Modulate Antifungal Drug Susceptibility. mBio 2019; 10:mBio.01726-18. [PMID: 30602579 PMCID: PMC6315099 DOI: 10.1128/mbio.01726-18] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Genome instability is detrimental for living things because it induces genetic disorder diseases and transfers incorrect genome information to descendants. Therefore, living organisms have evolutionarily conserved signaling networks to sense and repair DNA damage. However, how the DNA damage response pathway is regulated for maintaining the genome integrity of fungal pathogens and how this contributes to their pathogenicity remain elusive. In this study, we investigated the DNA damage response pathway in the basidiomycete pathogen Cryptococcus neoformans, which causes life-threatening meningoencephalitis in immunocompromised individuals, with an average of 223,100 infections leading to 181,100 deaths reported annually. Here, we found that perturbation of Rad53- and Chk1-dependent DNA damage response pathways attenuated the virulence of C. neoformans and increased its susceptibility to certain antifungal drugs, such as amphotericin B and flucytosine. Therefore, our work paves the way to understanding the important role of human fungal DNA damage networks in pathogenesis and antifungal drug susceptibility. Living organisms are constantly exposed to DNA damage stress caused by endogenous and exogenous events. Eukaryotic cells have evolutionarily conserved DNA damage checkpoint surveillance systems. We previously reported that a unique transcription factor, Bdr1, whose expression is strongly induced by the protein kinase Rad53 governs DNA damage responses by controlling the expression of DNA repair genes in the basidiomycetous fungus Cryptococcus neoformans. However, the regulatory mechanism of the Rad53-dependent DNA damage signal cascade and its function in pathogenicity remain unclear. Here, we demonstrate that Rad53 is required for DNA damage response and is phosphorylated by two phosphatidylinositol 3-kinase (PI3K)-like kinases, Tel1 and Mec1, in response to DNA damage stress. Transcriptome analysis revealed that Rad53 regulates the expression of several DNA repair genes in response to gamma radiation. We found that expression of CHK1, another effector kinase involved in the DNA damage response, is regulated by Rad53 and that CHK1 deletion rendered cells highly susceptible to DNA damage stress. Nevertheless, BDR1 expression is regulated by Rad53, but not Chk1, indicating that DNA damage signal cascades mediated by Rad53 and Chk1 exhibit redundant and distinct functions. We found that perturbation of both RAD53 and CHK1 attenuated the virulence of C. neoformans, perhaps by promoting phagosome maturation within macrophage, reducing melanin production, and increasing susceptibility to oxidative stresses. Furthermore, deletion of both RAD53 and CHK1 increased susceptibility to certain antifungal drugs such as amphotericin B. This report provides insight into the regulatory mechanism of fungal DNA damage repair systems and their functional relationship with fungal virulence and antifungal drug susceptibility.
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Bordallo-Cardona MÁ, Escribano P, Marcos-Zambrano LJ, Díaz-García J, de la Pedrosa EG, Cantón R, Bouza E, Guinea J. Low and constant micafungin concentrations may be sufficient to lead to resistance mutations in FKS2 gene of Candida glabrata. Med Mycol 2018; 56:903-906. [PMID: 29228268 DOI: 10.1093/mmy/myx124] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 10/12/2017] [Indexed: 12/21/2022] Open
Abstract
We studied the ability of five echinocandin-susceptible C. glabrata isolates to acquire in vitro resistance to anidulafungin and micafungin. All isolates became phenotypically resistant after 2-4 days of exposure to low and constant micafungin concentrations (P < .05). Mutations in the HS1 region of the FKS2 gene were found in all isolates. The acquisition of resistance was not related to the previous use of antifungal treatment in the patients or the presence of mutations at MSH2 gene. We found differences (P < .0001) in the median survival of Galleria mellonella larvae infected with FKS2 mutant isolates (5 days) and wild-type isolates (3 days).
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Affiliation(s)
- María Ángeles Bordallo-Cardona
- Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain.,Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | - Pilar Escribano
- Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain.,Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | - Laura Judith Marcos-Zambrano
- Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain.,Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | - Judith Díaz-García
- Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain.,Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | - Elia Gómez de la Pedrosa
- Clinical Microbiology, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Biomédica, Madrid, Spain.,Red Española de Investigación en Patología Infecciosa (REIPI), Madrid, Spain
| | - Rafael Cantón
- Clinical Microbiology, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Biomédica, Madrid, Spain.,Red Española de Investigación en Patología Infecciosa (REIPI), Madrid, Spain
| | - Emilio Bouza
- Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain.,Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain.,CIBER Enfermedades Respiratorias-CIBERES (CB06/06/0058), Madrid, Spain.,Medicine Department, School of Medicine, Universidad Complutense de Madrid, Madrid, Spain
| | - Jesús Guinea
- Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain.,Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain.,CIBER Enfermedades Respiratorias-CIBERES (CB06/06/0058), Madrid, Spain.,Medicine Department, School of Medicine, Universidad Complutense de Madrid, Madrid, Spain
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46
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Biswas C, Marcelino VR, Van Hal S, Halliday C, Martinez E, Wang Q, Kidd S, Kennedy K, Marriott D, Morrissey CO, Arthur I, Weeks K, Slavin MA, Sorrell TC, Sintchenko V, Meyer W, Chen SCA. Whole Genome Sequencing of Australian Candida glabrata Isolates Reveals Genetic Diversity and Novel Sequence Types. Front Microbiol 2018; 9:2946. [PMID: 30559734 PMCID: PMC6287553 DOI: 10.3389/fmicb.2018.02946] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 11/16/2018] [Indexed: 12/31/2022] Open
Abstract
Candida glabrata is a pathogen with reduced susceptibility to azoles and echinocandins. Analysis by traditional multilocus sequence typing (MLST) has recognized an increasing number of sequence types (STs), which vary with geography. Little is known about STs of C. glabrata in Australia. Here, we utilized whole genome sequencing (WGS) to study the genetic diversity of 51 Australian C. glabrata isolates and sought associations between STs over two time periods (2002-2004, 2010-2017), and with susceptibility to fluconazole by principal component analysis (PCA). Antifungal susceptibility was determined using Sensititre YeastOneTM Y010 methodology and WGS performed on the NextSeq 500 platform (Illumina) with in silico MLST STs inferred by WGS data. Single nucleotide polymorphisms (SNPs) in genes linked to echinocandin, azole and 5-fluorocytosine resistance were analyzed. Of 51 isolates, WGS identified 18 distinct STs including four novel STs (ST123, ST124, ST126, and ST127). Four STs accounted for 49% of isolates (ST3, 15.7%; ST83, 13.7%; ST7, 9.8%; ST26, 9.8%). Split-tree network analysis resolved isolates to terminal branches; many of these comprised multiple isolates from disparate geographic settings but four branches contained Australian isolates only. ST3 isolates were common in Europe, United States and now Australia, whilst ST8 and ST19, relatively frequent in the United States, were rare/absent amongst our isolates. There was no association between ST distribution (genomic similarity) and the two time periods or with fluconazole susceptibility. WGS identified mutations in the FKS1 (S629P) and FKS2 (S663P) genes in three, and one, echinocandin-resistant isolate(s), respectively. Both mutations confer phenotypic drug resistance. Twenty-five percent (13/51) of isolates were fluconazole-resistant (MIC ≥ 64 μg/ml) of which 9 (18%) had non wild-type MICs to voriconazole and posaconazole. Multiple SNPs were present in genes linked to azole resistance such as CgPDR1 and CgCDR1, as well as several in MSH2; however, SNPs occurred in both azole-susceptible and azole-resistant isolates. Although no particular SNP in these genes was definitively associated with resistance, azole-resistant/non-wild type isolates had a propensity to harbor SNPs resulting in amino acid substitutions in Pdr1 beyond the first 250 amino acid positions. The presence of SNPs may be markers of STs. Our study shows the value of WGS for high-resolution sequence typing of C. glabrata, discovery of novel STs and potential to monitor trends in genetic diversity. WGS assessment for echinocandin resistance augments phenotypic susceptibility testing.
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Affiliation(s)
- Chayanika Biswas
- Centre for Infectious Diseases and Microbiology-Public Health, Westmead Hospital, Sydney, NSW, Australia.,Westmead Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Vanessa R Marcelino
- Westmead Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia.,Centre for Infectious Diseases and Microbiology, Westmead Institute for Medical Research, Westmead, NSW, Australia.,Marie Bashir Institute for Emerging Infectious Diseases and Biosecurity, The University of Sydney, Sydney, NSW, Australia
| | - Sebastiaan Van Hal
- Department of Infectious Diseases and Microbiology, New South Wales Health Pathology, Royal Prince Alfred Hospital, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Catriona Halliday
- Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR, New South Wales Health Pathology, Westmead Hospital, Sydney, NSW, Australia
| | - Elena Martinez
- Centre for Infectious Diseases and Microbiology-Public Health, Westmead Hospital, Sydney, NSW, Australia.,Westmead Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Qinning Wang
- Centre for Infectious Diseases and Microbiology-Public Health, Westmead Hospital, Sydney, NSW, Australia.,Westmead Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Sarah Kidd
- National Mycology Reference Centre, SA Pathology, Adelaide, SA, Australia
| | - Karina Kennedy
- Department of Microbiology and Infectious Diseases, Canberra Hospital & Health Services, Australian National University Medical School, Canberra, ACT, Australia
| | - Deborah Marriott
- Department of Microbiology and Infectious Diseases, St Vincent's Hospital, Sydney, NSW, Australia
| | - C Orla Morrissey
- Department of Infectious Diseases, Alfred Health and Monash University, Melbourne, VIC, Australia
| | - Ian Arthur
- Department of Microbiology, PathWest Laboratory Medicine, Queen Elizabeth II Medical Centre, Perth, WA, Australia
| | - Kerry Weeks
- Department of Microbiology and Infectious Diseases, Royal North Shore Hospital, Sydney, NSW, Australia
| | - Monica A Slavin
- National Centre for Infections in Cancer, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Tania C Sorrell
- Westmead Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia.,Centre for Infectious Diseases and Microbiology, Westmead Institute for Medical Research, Westmead, NSW, Australia.,Marie Bashir Institute for Emerging Infectious Diseases and Biosecurity, The University of Sydney, Sydney, NSW, Australia
| | - Vitali Sintchenko
- Centre for Infectious Diseases and Microbiology-Public Health, Westmead Hospital, Sydney, NSW, Australia.,Westmead Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia.,Centre for Infectious Diseases and Microbiology, Westmead Institute for Medical Research, Westmead, NSW, Australia.,Marie Bashir Institute for Emerging Infectious Diseases and Biosecurity, The University of Sydney, Sydney, NSW, Australia
| | - Wieland Meyer
- Centre for Infectious Diseases and Microbiology-Public Health, Westmead Hospital, Sydney, NSW, Australia.,Westmead Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia.,Centre for Infectious Diseases and Microbiology, Westmead Institute for Medical Research, Westmead, NSW, Australia.,Marie Bashir Institute for Emerging Infectious Diseases and Biosecurity, The University of Sydney, Sydney, NSW, Australia
| | - Sharon C-A Chen
- Centre for Infectious Diseases and Microbiology-Public Health, Westmead Hospital, Sydney, NSW, Australia.,Westmead Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia.,Centre for Infectious Diseases and Microbiology, Westmead Institute for Medical Research, Westmead, NSW, Australia.,Marie Bashir Institute for Emerging Infectious Diseases and Biosecurity, The University of Sydney, Sydney, NSW, Australia.,Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR, New South Wales Health Pathology, Westmead Hospital, Sydney, NSW, Australia
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Paul S, McDonald WH, Moye-Rowley WS. Negative regulation of Candida glabrata Pdr1 by the deubiquitinase subunit Bre5 occurs in a ubiquitin independent manner. Mol Microbiol 2018; 110:309-323. [PMID: 30137659 DOI: 10.1111/mmi.14109] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2018] [Indexed: 12/24/2022]
Abstract
The primary route for development of azole resistance in the fungal pathogen Candida glabrata is acquisition of a point mutation in the PDR1 gene. This locus encodes a transcription factor that upon mutation drives high level expression of a range of genes including the ATP-binding cassette transporter-encoding gene CDR1. Pdr1 activity is also elevated in cells that lack the mitochondrial genome (ρ° cells), with associated high expression of CDR1 driving azole resistance. To gain insight into the mechanisms controlling activity of Pdr1, we expressed a tandem affinity purification (TAP)-tagged form of Pdr1 in both wild-type (ρ+ ) and ρ° cells. Purified proteins were analyzed by multidimensional protein identification technology mass spectrometry identifying a protein called Bre5 as a factor that co-purified with TAP-Pdr1. In Saccharomyces cerevisiae, Bre5 is part of a deubiquitinase complex formed by association with the ubiquitin-specific protease Ubp3. Genetic analyses in C. glabrata revealed that loss of BRE5, but not UBP3, led to an increase in expression of PDR1 and CDR1 at the transcriptional level. These studies support the view that Bre5 acts as a negative regulator of Pdr1 transcriptional activity and behaves as a C. glabrata-specific modulator of azole resistance.
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Affiliation(s)
- Sanjoy Paul
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - W Hayes McDonald
- Department of Biochemistry, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - W Scott Moye-Rowley
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
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48
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Ksiezopolska E, Gabaldón T. Evolutionary Emergence of Drug Resistance in Candida Opportunistic Pathogens. Genes (Basel) 2018; 9:genes9090461. [PMID: 30235884 PMCID: PMC6162425 DOI: 10.3390/genes9090461] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 09/14/2018] [Accepted: 09/17/2018] [Indexed: 01/08/2023] Open
Abstract
Fungal infections, such as candidiasis caused by Candida, pose a problem of growing medical concern. In developed countries, the incidence of Candida infections is increasing due to the higher survival of susceptible populations, such as immunocompromised patients or the elderly. Existing treatment options are limited to few antifungal drug families with efficacies that vary depending on the infecting species. In this context, the emergence and spread of resistant Candida isolates are being increasingly reported. Understanding how resistance can evolve within naturally susceptible species is key to developing novel, more effective treatment strategies. However, in contrast to the situation of antibiotic resistance in bacteria, few studies have focused on the evolutionary mechanisms leading to drug resistance in fungal species. In this review, we will survey and discuss current knowledge on the genetic bases of resistance to antifungal drugs in Candida opportunistic pathogens. We will do so from an evolutionary genomics perspective, focusing on the possible evolutionary paths that may lead to the emergence and selection of the resistant phenotype. Finally, we will discuss the potential of future studies enabled by current developments in sequencing technologies, in vitro evolution approaches, and the analysis of serial clinical isolates.
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Affiliation(s)
- Ewa Ksiezopolska
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology (BIST), 08003 Barcelona, Spain.
- Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain.
| | - Toni Gabaldón
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology (BIST), 08003 Barcelona, Spain.
- Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain.
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain.
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Fungal Resistance to Echinocandins and the MDR Phenomenon in Candida glabrata. JOURNAL OF FUNGI (BASEL, SWITZERLAND) 2018; 4:jof4030105. [PMID: 30200517 PMCID: PMC6162769 DOI: 10.3390/jof4030105] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 08/28/2018] [Accepted: 08/30/2018] [Indexed: 12/17/2022]
Abstract
Candida glabrata has thoroughly adapted to successfully colonize human mucosal membranes and survive in vivo pressures. prior to and during antifungal treatment. Out of all the medically relevant Candida species, C. glabrata has emerged as a leading cause of azole, echinocandin, and multidrug (MDR: azole + echinocandin) adaptive resistance. Neither mechanism of resistance is intrinsic to C. glabrata, since stable genetic resistance depends on mutation of drug target genes, FKS1 and FKS2 (echinocandin resistance), and a transcription factor, PDR1, which controls expression of major drug transporters, such as CDR1 (azole resistance). However, another hallmark of C. glabrata is the ability to withstand drug pressure both in vitro and in vivo prior to stable "genetic escape". Additionally, these resistance events can arise within individual patients, which underscores the importance of understanding how this fungus is adapting to its environment and to drug exposure in vivo. Here, we explore the evolution of echinocandin resistance as a multistep model that includes general cell stress, drug adaptation (tolerance), and genetic escape. The extensive genetic diversity reported in C. glabrata is highlighted.
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Byun SA, Won EJ, Kim MN, Lee WG, Lee K, Lee HS, Uh Y, Healey KR, Perlin DS, Choi MJ, Kim SH, Shin JH. Multilocus Sequence Typing (MLST) Genotypes of Candida glabrata Bloodstream Isolates in Korea: Association With Antifungal Resistance, Mutations in Mismatch Repair Gene (Msh2), and Clinical Outcomes. Front Microbiol 2018; 9:1523. [PMID: 30057573 PMCID: PMC6053515 DOI: 10.3389/fmicb.2018.01523] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 06/19/2018] [Indexed: 12/22/2022] Open
Abstract
Candida glabrata bloodstream infection (BSI) isolates from a particular geographic area have been reported to comprise a relatively small number of the major sequence types (STs) by multilocus sequence typing (MLST) analysis. Yet little is known about the characteristics of major ST strains of C. glabrata. To address this question in Korea, we investigated antifungal resistance and non-synonymous mutations of the mismatch repair gene (msh2 mutations) in C. glabrata BSI isolates, as well as associated clinical characteristics, and compared the results according to MLST genotype. We assessed a total of 209 C. glabrata BSI isolates from seven hospitals in Korea for 2 years (2009 and 2014). Clinical features of candidemia and their outcomes were analyzed for 185 available cases. According to MLST, ST7 (47.8%) was the most common type, followed by ST3 (22.5%); the remainder represented 28 types of minor STs (29.7%). Fluconazole-resistance (FR) rates for ST7, ST3, and other strains were 9.0% (9/100), 8.5% (4/47), and 4.8% (3/62), respectively, and all were susceptible to amphotericin B and micafungin. All ST7 isolates harbored the V239L mutation in msh2, known to confer hypermutability, while 91.5% of ST3 isolates did not harbor the msh2 mutation. Overall, isolates of the same ST had identical msh2 mutations, with the exception of nine isolates. The msh2 mutations were identified in 68.8% (11/16) of the FR isolates and 67.4% (130/193) of the fluconazole susceptible-dose dependent isolates. There was no significant difference in all clinical characteristics between ST3 and ST7. However, the 30-day mortality of C. glabrata candidemia due to the two major ST (ST3 or ST7) strains was significantly higher than that of candidemia due to other minor ST strains (45.1 vs. 25.0%, p < 0.05). Multivariate logistic regression analysis also showed that two major STs (ST3 and ST7) were independent predictors of 30-day mortality. This study showed for the first time that two STs (ST7 and ST3) were predominant among BSI isolates in Korea, and that C. glabrata BSI isolates belonging to two major MLST genotypes are characterized by higher mortality. In addition, most msh2 mutations align with MLST genotype, irrespective of FR.
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Affiliation(s)
- Seung A Byun
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, South Korea
| | - Eun Jeong Won
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, South Korea
| | - Mi-Na Kim
- Department of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, South Korea
| | - Wee Gyo Lee
- Department of Laboratory Medicine, Ajou University School of Medicine, Suwon, South Korea
| | - Kyungwon Lee
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Hye Soo Lee
- Department of Laboratory Medicine, Chonbuk National University Hospital, Jeonju, South Korea
| | - Young Uh
- Department of Laboratory Medicine, Yonsei University Wonju College of Medicine, Wonju, South Korea
| | - Kelley R Healey
- Public Health Research Institute, New Jersey Medical School-Rutgers, The State University of New Jersey, Newark, NY, United States
| | - David S Perlin
- Public Health Research Institute, New Jersey Medical School-Rutgers, The State University of New Jersey, Newark, NY, United States
| | - Min Ji Choi
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, South Korea
| | - Soo Hyun Kim
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, South Korea
| | - Jong Hee Shin
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, South Korea
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